UNITED STATES DEPARTMENT OF COMMERCE

Frederick H. Mueller, Secretary

NATIONAL BUREAU OF STANDARDS

A. V. Astin, Director

Research Highlights

of the

National Bureau

of Standards

Annual Report, Fiscal Year 1959

December 1959

Miscellaneous Publication 229

For sale by the Superintendent of Documents, U.S. Government Printing Office

Washington 25, D.C. - Price 55 cents

Contents

Page

1. General Review 1 Technical Activities 2

Administrative Activities 13

Programs Planned 14

Publications 15

2. Highlights of the Research Program 17

2.1. Electricity and Electronics 17

Automatically measuring high resistance 17, Computable standard of capacitance 17, Electron devices data service 18, Ceramic

wafer tubes 18, Methods for testing servo motors 18, Dielectric

properties of nylon 18, Preferred circuits 19, Recording spectroradiometer 19, Electronic metrology 19, Galvanic corrosion of

metallic silver 19, Evaluating storage batteries 20, Dry cell

specifications 20, International comparison of transformer ratio

measurements 20.

2.2. Optics and Metrology 21

Color differences by high-speed computer 22, New color charts

22, Lens aberrations measured 22, Lens distortion measurements refined 23, Lens calibration methods analyzed 23, Anticollision lights for airplanes 23, Visual landing aids devised 24,

Photometric equipment improved 24, Bearing ball and cylinder

measurements improved 24, Interference fringe path extended

24, Research on improved lightwave length standards 25, Lens

design by high-speed computer 26, High-precision gage blocks

26, Advances in refractometry 26, Chemistry of photographic

fixation 27, New candlepower standards 27, Records reduction

27, Interferometer for large surfaces 27, Filter and brightness

standards 27.

2.3. Heat 28

High-temperature resistance thermometry 29, Pyrometer symposium 29, Precise measurement of shock-wave velocity 30,

Low-temperature thermometry 31, Viscosity standards and

measurements 31, Significance of spectroscopic measurement

of flame temperature 32, Thermodynamic properties of the

light elements 32, Nitrogen-fluorine bond energy 33, Physicochemical processes in flames 33, Statistical thermodynamics 33,

The nature of superconductivity 34, Compressibility of polymers 35, Reaction of chlorine beams with nickel at high temperatures 35, Free radicals research program 36.

2.4. Atomic and Radiation Physics 38

Spectroscopic research 38, Rydberg constant confirmation 39,

Astrophysics 39, High-resolution infrared spectrometer 40,

Radiometry 40, Solid-state research 40, Electron scattering 41,

Electron polarization 41, Electron instrumentation 41, Lowtemperature electron bombardment 42, Physics of negative

ions 42, Atomic standards of frequency 43, Scintillation counting of neutron emission rates 43, Penetration of gamma radiation, 43. Radioactivity standards 44, X-ray studies 44, Linear

electron accelerator 44, High energy radiation 45, Gammaand X-ray calibrations 45, Dosimetry 45.

• • • 111
Page

2.5. Chemistry 46

Analysis of tritium-labeled compounds 46, Acid strength in

benzene 48, Determination of phosphate, silicate, and arsenate

48, Separating metallic elements in high-temperature alloys 49,

Air pollution 49, Molten salt studies 49, Abrasive jet 50, Thickness gage 51, International comparison of techniques for determining purity 51, Purification of a special lot of mercury 51,

Reagent chemicals 53, Calibrated glass spheres 53, Uranium

isotopic standards 53, Spectrometric analysis by X-rays 54,

Nuclear magnetic resonance studies 54.

2.6. Mechanics 55

Expanded pressure-calibration service 55, Vibration pickup

calibration service 56, Stroboscopic vibration analyzer devised

56, Vibration dampers evaluated 57, New acoustical theory

proposed 57, Uniform magnetic field equipment built 57,

Improved hygrometers developed 57, Fuel flow-rate calibration facilities 58, Inertial forces in unsteady flow studied 59,

Internal progressive waves investigated 59, Instability of

laminar flow examined 59, Dynamic properties of materials

measured 60, Strain gage evaluation facility 60, Thermocouple

reference being determined 60, Jet engine thermocouples tested

61, Jet -engine combustion explored 63.

2.7. Organic and Fibrous Materials 63

Degradation of collagen 64, Water penetration test for sole leather

64, Power loss and operating temperature of tires 64, Glass

transitions in the rubber-sulfur system 65, Interlaboratory

studies of test methods 65, Electrical resistivity of fabrics 65,

Surface tension of high-viscosity liquids 66, Creep of transparent

plastics 67, Radiation-resistance polymers 67, Crystallization of

crosslinked polymers 67, Thermal stability of polymers 68,

Interactions in polymer solutions 68, Physical properties of

tooth enamel and dentin 69, Elastomeric dental impression

materials 69, Dental fluorometer 69, Dental X-ray radiation 70.

2.8. Metallurgy 71

Heat-resistant materials 71, Creep of high-purity nickel 71,

Tensile and yield strengths of die steels 71, Crystalline diffusion

72, Fatigue properties of high-strength steels 72, Surface reactions 72, Dislocations in aluminum alloys and brass 72, Growth

of metal crystals from their vapor 72, Nuclear magnetic reso- nance 73, Corrosion research 74, Stress corrosion cracking 74,

Single crystals 74, Free radicals 74, Preferentially oriented

crystals 74, Uranium alloys 74, Improved gage-block materials

75, Titanium data charted 76, Stainless steel properties evaluated

77.

2.9. Mineral Products 77

New data on ferroelectric materials 77, Phase changes in silicates

78, Strength of glass at elevated temperatures 79, Infrared

transmitting glasses 80, Physical and chemical properties of

glass surfaces 80, Impact coating for rockets and missiles 81,

Thermal-radiation standards for space vehicles 81, Phase

equilibria in rare -earth oxide systems 83, Solid -gas reactions

involving light -metal oxides 83, High-temperature strain gages

84, Dynamic mechanical properties of refractory oxides 85,

Infrared absorption spectra of compounds under high pressure

85, Structure of solids containing free radicals 86, Standard

X-ray diffraction patterns 87.

iv
Page

2.10. Building Technology 87

High-temperature thermal conductivity 87, Thermal conductivity

reference specimens 88, Physical properties of insulating concretes 88, Joint sealing materials 88, Mechanism of fire extinguishment 89, Surface flammability of materials 89, Standards

for refrigerated trailers 89, Underground pipe insulation 90,

Asphalt studies 90, Wear resistance of flooring materials 90,

Lightning hazards of buildings 90, Safety codes 91.

2.11. Applied Mathematics 91

Numerical analysis 92, Training program 42, New eigenvalue

method 92, Stability of recurrence relations 92, Machine translation 93, Mathematical tables 93, Improvement in facilities 93,

Digital computation 94, Design of experiments 95, Life testing

and reliability 95, Interlaboratory comparisons 95, Statistical

services 96, Mathematical physics 96.

2.12. Data-Processing Systems 97

SEAC and analog computing facilities 97, Pilot data processor

98, Components and techniques 98, Cloud height data analyzer

99, Digital circuitry 99, Document retrieval device 100, Packaged computer circuitry 100, Digital systems research 100,

Flight-maneuver data processing 100, Automatic processing of

electrocardiograph data 101, Automatic mail sorting developments 101, Computer data editing and reporting 102, Mechanization of patent searching 102, Research information center

102, Additional data processing applications 102.

2.13. Cryogenic Engineering 103

Low-temperature properties of materials 104, Insulation 104,

Liquified gas flow 105, Cryogenic equipment 105, Ortho-para

conversion of hydrogen 106, Hydrogen distillation 106, Cryogenic engineering data 107, Helium properties 107, Gas

liquefaction 108.

2.14. Radio Propagation 108

Radio Propagation Physics 108

Electron density measured directly 109, Electron densities

measured to 750 km 109, True ionospheric reflection heights

recovered 109, Exosphere approximated 110, Upper F-region

investigation planned 111, World maps of the ionosphere

issued 111, Ionosphere mapped by computer 111, Efficient

propagation mode discovered in Pacific 112, Airglow and

aurora origin questioned 112, Scattering phenomena in the

equatorial ionosphere 112, Ionosphere measured by satellite

signals 113, Whistlers' direction demonstrated 113, Data

center maintained for ionosphere and airglow 113.

Radio Propagation Engineering 113

RF transmission loss predictions improved 114, Radio refractive index mapped 115, Refractometers developed 115,

Model range helps predict terrain effects 115, Bistatic radar

cross sections measured 115, Attenuation of building materials measured 116, Television field-strength analyzed 116,

Tropospheric scatter consulting 116, VLF noise effects measured 117, Frequency and power studied for VLF standard

broadcast 117, Radio noise data gathered 117, Teletype

errors measured 118.
Page

2.14 Radio Propagation—Continued

Radio Communication and Systems 119

New division established 119, Arctic communication studied

119, Transarctic terminal sought 120, Ionospheric signals

studied 120, Meteor burst communication system 120,

Modulation techniques investigated 120, Special antennas

developed 121, Polar icecap conductivity 121, Pulse propagation problem solved 122, Radio navigation studies made

122, Space communication studies begin 122.

2.15. Radio Standards 122

Attenuation calibration service 122, Field-strength standards

being developed 123, Frequency standards improved 123,

Quartz oscillators investigated 123, Impedance standards ana- lyzed 124, Impedance calibration techniques developed 124,

Receivers analyzed for spurious response 125, Noise-measuring

equipment designed 125, Power standards built 125, Voltage

calibration services 125, Dielectric properties determined 126,

Magnetic properties of materials measured 126, Ferrites laboratory 128, Microwave interferometers developed 128, Time

and frequency standards 128, Electronic Calibration Center 130.

2.16. Weights and Measures 130

2.17. Basic Instrumentation .

'. 132

Instrument reference service enlarged 132, Instrumentation

methods surveyed 132.

3. Appendixes 133

3.1. Organization 133

3.2. Fiscal Data on NBS Program 138

3.3. Public Law 85-890 Amending Organic Act of the NBS 139

3.4. Advisory Committees 140

3.5. Awards and Honors 143

3.6. Education and Training Program , 144

3.7. Cooperative Research With Industry 146

3.8. List of Publications and Patents 148

vi
1. General Review

Last year the National Bureau of Standards presented in formal ceremony

a set of State standards to the State of Alaska. In the same year, the Director

of the Bureau participated in making final recoipmendations to the General

Conference of the International Bureau of Weights and Measures to accept

an atomic definition of the meter. These two events indicate the national

and international importance of standards activities and the expanding

interrelation of these activities among science, industry, and government.

The past year was an eventful one for the Bureau. On the scientific side,

it was a period of significant beginnings to new programs and of continued

development in important basic programs. Special attention was given to

improving standards and measurement techniques in high temperature, pressure, atomic standards of length, and atomic standards of frequency. Advances were made in studies of the molecular structure of alloys, in the determination of microquantities of tritium, and in the characterization of the

atmosphere in regions associated with satellite exploration. These activities,

and many others, are undertaken in response to growing demands upon the

Bureau to advance standards and measurement techniques and to provide ac- curate data in areas where American scientists are becoming especially

active. It is the Bureau's mission 1 to provide the central basis for a complete, consistent system of physical measurement of national scope adequate

for the expanding national activity in scientific research. Emphasis in the

coming year is expected in the fields of standards and measurement, highpurity materials, plasma physics, and very high pressures.

On the administrative and budgetary side, the Bureau was given an in- crease in its appropriation to meet the need for strengthening basic research

programs and, more specifically, to accelerate research in the field of high

temperature. Recognition was given to the pressing need to provide for a higher level of fundamental research with funds provided by the Congress,

and to reduce the amount of work done for other government agencies.

This report will present some of the work, studies, and accomplishments

of the various laboratories of the Bureau. The descriptions of these activities will be necessarily brief and, in most cases, merely summaries of

work which will be fully described in the formal scientific publications of the

Bureau.

1 The Bureau's responsibilities, as denned by the Congress, may be summarized as follows:

(1) Development and maintenance of the national standards of measurement, and the provision of means

for making measurements consistent with those standards;

(2) determination of physical constants and properties of materials;

(3) development of methods for testing materials, mechanisms, and structures, and the making of such

tests as may be necessary, particularly for government agencies;

(4) cooperation in the establishment of standard practices, incorporated in codes and specifications;

(5) advisory service to government agencies on scientific and technical problems; and

(6) invention and development of devices to serve special needs of the government.

1
Technical Activities

As in previous years, the technical program was concerned principally

with (1) standards and methods of physical measurement, and (2) precise

measurement of physical constants and the basic properties of materials.

Other broad areas of effort included radio propagation research, data

processing systems, applied mathematics, building technology, and cryogenic

engineering. Some of the more important accomplishments of the year are

given in the following paragraphs. More complete details of these projects

may be found in section 2, page 17 et seq.

Standards and Measurement Methods, To provide basic data and

calibration techniques for the rapidly advancing fields of aeronautics and

space science, efforts were made to extend precise measurement of both

temperature and pressure into increasingly higher ranges. Advances in

high-temperature measurement included the extension of the calibration

range of optical pyrometers from 2,400° to 3,800° C, construction of a highcurrent arc as a source of controlled temperatures, and design of a special

type of high-temperature resistance thermometer for interpolating between

fixed points on the International Temperature Scale. To obtain data for

the ultimate establishment of additional fixed points on the pressure scale,

equipment was developed and constructed for studying the behavior of

various materials at pressures up to 1,500,000 lb/in.2 For the calibration

of instruments used to measure high transient pressures, apparatus was devised that generates pressure steps of accurately known amplitudes up to

50,000 lb /in.2

In research on atomic standards of length, three devices were developed

which provide extremely narrow spectral lines. These narrow lines make

possible very precise standards of length based on the wavelength of radiation from mercury atoms. Two of the devices utilize beams of mercury

atoms to obtain a line 0.0002 Angstrom in width; the third employs a magnetic filter with mercury-198 vapor to produce an absorption line 0.0003 A

wide. Besides serving as sources of very narrow spectral lines, the beam

devices were used to obtain more precise information on the properties of the

mercury nucleus as seen in the isotope shifts and hyperfine structure of the

lines.

Progress was also made in the development of standards of frequency

and time based on invariant properties of the atom. A precision of 2 parts

in 10 billion was achieved with an atomic clock using a beam of cesium

atoms. In other frequency-standard work, hyperfine and Zeeman resonances

in cesium and rubidium vapors were investigated. Hyperfine line widths in

rubidium as narrow as 20 cycles at 7,000 megacycles were observed. Two

rubidium-vapor atomic clocks were under construction using these results.

A recalibration of the Bureau's carbon-14 standards formed the basis for

a new determination of the half-life of carbon-14. Improvements were made

in the accuracy with which the Bureau calibrates instruments used as laboratory standards for gamma-ray measurements by hospitals, industry, and
government. A number of intercomparisons of radioactivity standards

were carried out with North and South American, European, and African

standardizing laboratories.

To provide a basic reference for humidity measurments, a gravimetric

hygrometer was completed. Designed to permit direct weighing of the water

contained in known gas volumes, this instrument should make it possible to

attain needed improvement in measuring humidity, particularly at temperatures below the freezing point, as in atmospheric studies.

During the past decade vibration measurements have come to play an important part in the development of ships, aircraft, and space vehicles. To

provide greater accuracy in these measurements, an improved standard was

developed for calibrating vibration pickups.

Precise interferometric measurements on nine lines of the helium spectrum

led to an independent confirmation of the Rydberg constant, which since

Equipment used in the redetermination of the Rydberg constant. As a result

of this work, it is now the most accurately known atomic constant. The work

was done as part of a program of obtaining more accurate values for important

physical constants (pages 3, 29).

3
1952 has been based on the work of a single set of observers. The Rydberg

constant relates the energy levels of atoms, and enters into the frequency or

wave number formulas for all atomic spectra. The Bureau measurements

reevaluated data used in an early determination of the Rydberg constant,

bringing this earlier calculation into agreement with the presently accepted

value.

Other work on standards and measurement covered a variety of fields.

For example, an improved method was worked out for the precise measurement of shock-wave properties; apparatus was devised for special measurements of the heat conductivity of explosives and solid propellants; a

precision phase shifter was completed for high-frequency attenuation measurements; a high-resolution infrared spectrometer was designed and constructed; and a technique was developed for measuring ball bearings for

high-speed gyroscopes to an accuracy of about five-millionths of an inch.

Properties of Matter and Materials. Much of the work on materials

was directed toward the accumulation of basic data on their general properties, constants, structure, and behavior at very high temperatures. For

development of heat-resistant materials, extensive studies were made of the

solid state reactions that occur in alloys of chromium, iron, nickel, and

molybdenum. Under sponsorship of the Wright Air Development Center, a fundamental investigation was conducted to clarify the mechanisms of the

processes used to apply refractory oxide coatings to missiles and rockets.

Another program was undertaken for WADC to obtain high-temperature

thermodynamic data on the light elements—lithium, magnesium, aluminum,

and beryllium—and their compounds. These data are essential for the

prediction of chemical reactions at high temperatures and for a systematic

evaluation of prospective high-energy solid propellants for rockets.

For use in high-temperature strain gages, a cement composition was developed which has higher electrical resistivity in the range 425° to 1,000° C

than any similar material now available. As part of a program to determine

the strength of ceramics at elevated temperatures, the elastic constants of

aluminum oxide single crystals (sapphire) were determined to high precision. Materials such as aluminum oxide are of interest not only for hightemperature structural use but also as electrical insulators.

Other projects, important to the efficient utilization of liquefied-gas rocket

fuels, dealt with the properties of materials at extremely low temperatures,

not far above absolute zero. For insulation in this temperature range,

evacuated laminates were developed that give tenfold improvement over the

best evacuated powders. The laminates consist of alternate layers of aluminum foil and thin glass-fiber paper. Their application in engineering design

should permit much greater simplicity and compactness in the large vessels

now used to hold liquid hydrogen or liquid helium.

A convenient analytical method was developed for determining as little as one-billionth of a milligram of tritium—the radioactive isotope of hydrogen—in water-soluble, nonvolatile materials. This method makes the quanti4
tative determination of tritium relatively easy and thus removes the most

important obstacle to widespread use of tritium as a research tool in organic

and biological chemistry, where its possible applications are virtually

unlimited.

The separation and determination of small amounts of phosphate, silicate,

and arsenate when they occur together in solution has long been a difficult

problem. During the year, a rapid, accurate method was developed for

quantitatively separating and determining these ions. The method should

prove useful in controlling the quality of chemicals, metals, glasses, and

water which contain these salts as impurities.

Fundamental studies of photochemical reactions involved in air pollution

were conducted with the partial support of the Department of Health, Education, and Welfare. These studies were part of a larger program which

seeks knowledge of elementary chemical reactions and the mechanisms of

energy transfer. Extensive investigation of the primary dissociative processes for several compounds, showed that these compounds dissociate by

molecular rearrangement and that free radicals are formed in the primary

processes.

In an investigation of the behavior of solids under pressure, spectroscopic

evidence was found which shows changes in molecular structures under

pressures of 30,000 atmospheres. Information was obtained on the reaction

mechanisms involved in the degradation of synthetic resins and collagen—

the parent substance of leather—when exposed to high temperatures or to

nuclear radiation. In studies of semiconducting materials, the electrical

conductivity, Hall effect, and thermoelectric power of titanium dioxide were

measured over a wide temperature range.

Radio Propagation, The NBS Central Radio Propagation Laboratory

conducted a broad range of research projects on the fundamental nature of

radio waves, the basic theories of radio-wave propagation, and the characteristics of radio energy under widely varying conditions. In the course

of this work, a promising method was developed for studying the physics

of the upper reaches of the ionosphere. Utilizing special radar scatter techniques, the method permits studies of ionization at levels of the atmosphere

well above the reflecting layers reached by conventional sounding techniques and into the region now associated with satellite exploration.

Under the sponsorship of the Air Force Cambridge Research Center,

CRPL completed a 3-year investigation to determine the feasibility of a long-distance radio communication system based on reflections from meteor

trails. During the investigation, an experimental two-way communication

system was developed that can transmit messages at speeds up to 4,800 words

a minute—80 times the present speed of transmission by teletype. Results

of the study indicate that intermittent meteor burst communication can

compete effectively with other long-distance systems, and that it is relatively

free from ionospheric disturbances.

Further improvements were made in methods for predicting the tropospheric bending of radio waves in terms of the radio-refractive index at the

5
Two of the three 60-ft diameter parabaloidal antennas installed to make improved measurements of radio wave refraction in the earth's atmosphere

(pages 5, 115).

surface of the earth: these methods are expected to aid in improving radar

direction finding and radio missile or satellite guidance systems. Climatological maps of the surface radio-refractive index were prepared for the

United States and for the World. A method was developed for determining

the transmission loss for very closely spaced antennas. To aid in the solution of practical communication problems, a measurement technique was

devised for investigating the attenuation of radio waves in passing through

various building materials.

Applied Mathematics and Data Processing. A Research Information Center and Advisory Service on Information Processing, to be operated

jointly by the National Bureau of Standards and the National Science Foundation, was established at the Bureau. The new service is designed to bring

together research and development data on methods and equipment for the

automatic processing of scientific information.

Work continued on the Pilot Data Processor, a multipurpose computer

network for the experimental investigation of Government data processing

problems. During the year the logical plans for the entire PILOT system

were transcribed into a form suitable for processing on a high-speed computer to convert them into wiring tables describing the point-to-point electronic interconnections. Considerable progress was made in engineering

design and actual construction of this machine.

6
A study was made of the logical problems arising when several high-speed

electronic computers are connected together to work on a common large-scale

task. Computer routines were worked out for rapidly and precisely determining color differences between samples. In a study conducted for the

Veterans' Administration, a method was developed for using a high-speed

electronic computer to analyze data on human heartbeats.

Experiments in machine translation, which the Bureau has been conducting for the Army Office of Ordnance Research, indicated a promising avenue

of approach to practical production of English text from Russian technical

literature. A translation scheme was developed and feasibility studies

carried out on an electronic computer.

Research in mathematical physics included an analysis of the important

problem of the mechanics of turbulent diffusion by the techniques of statistical mechanics. A statistical approach was also applied in studying the

kinetic equation for a plasma. Other work included a determination of the

fluctuations in the annual flows and runoffs of rivers, investigations of the

behavior of the solutions of the first-order nonlinear Poincare equation and

the second-order nonlinear Rayleigh equation, and a study of the thermodynamics and hydrodynamics of two-phase flows.

Calibration, Testing, and Standard Samples. The current rapid

development of the Nation's technology was reflected in a greatly increased

demand for the Bureau's calibration services, and for new or more accurate

measurement standards in the more rapidly advancing fields such as electronics, high temperature, and high pressure. To aid in the calibration

work, extensive calibration programs are being established in the military

agencies and in many industries and private standards organizations. To

an increasing extent, the Bureau was called upon for assistance to the other

standards laboratories that have been set up.

The Bureau worked closely with the Department of Defense and its contractors in order to keep informed of new measurement problems and calibration needs. In particular, a joint NBS-U.S. Air Force Working Group

on precision measurements and calibrations was formed and began studies

of present and anticipated calibration requirements. Similar working re- lationships are being established with the other military services to determine

their present and future requirements.

The standardization needs of American industry were emphasized by the

results of questionnaires which various professional groups (Aerospace Indutries Association, National Security Industries Association, and Electronic

Industries Association) submitted to their affiliated industries. The Aerospace Industries Association surveyed about 70 large industries in its field

and found greatly increased measurement needs in a number of critical areas

such as microwave, temperature, vibration, and shock measurements. This

survey brought out the need for more basic research on measurement problems and increased dissemination of calibration procedures on an industrywide basis.

Within the limits of its facilities, the Bureau concentrated on those calibra7
tion activities that were most urgently needed by the country. Efforts were

made to develop improved standards and calibration techniques in critical

areas and to provide for calibration of master standards in other laboratories

in terms of the national standards. Plans were made for a million-pound

deadweight testing facility to calibrate devices for measuring large forces

such as rocket thrusts. A new high-energy accelerator was also being designed to provide needed measurement services in high-energy radiation.

Progress was made in adapting automatic methods to routine calibration

work in several areas. For example, automatic equipment was developed

to aid in the calibration of multibillion-ohm resistors, and electronic means

were devised for comparing line standards of length interferometrically.

The nature and scope of the Bureau's activity in calibration, testing, and

standard samples are shown for fiscal year 1959 in tables 1, 2, and 3, re- spectively. As a result of the growing interest in standards by science and

industry, the number of items in each of the three categories was significantly

greater than in 1958. The total number of calibrations and tests was 146,-

217, representing an increase of 12,056 over the previous year. In addition,

63,435 individual samples of certified standard materials were issued, as

compared with 55,523 for fiscal 1958. Thirty new standard materials were

developed during the year, bringing the total number of standard materials

now available to 614.

Fiscal year 1959 was the first full year of operation of the Bureau's new

Electronic Calibration Center. Although instrumentation for the center was

far from complete, it was able to carry an important part of the calibration

load, performing more than 8,500 individual calibrations in the radio-electronics field during the year. This figure was about 17 times the number

of such calibrations for the previous year.

More detailed descriptions of work in calibration, testing, and development of standard samples are given in section 2 within the subsections devoted to the corresponding research areas. Cooperative Activities. The Bureau cooperates extensively with Federal, State, and local governments; with national professional societies and

standardizing bodies; and with many international groups. In this way the

results of Bureau research are brought to bear on many current problems of

science and industry, particularly those relating to measurement standards,

building and safety codes, engineering and purchase specifications, and test

methods.

Cooperation with other Federal agencies ranges from the supplying of

technical information upon request to long-range projects undertaken

through various scientific and technical committees. An important example

of interagency cooperation is the development of Government specifications

and test methods. During the year at the request of the General Services

Administration, the Bureau accepted responsibility for developing and maintaining 5 additional Federal Specifications, making a total of 210 for which

it now has this responsibility. The Bureau also reviewed approximately 355

proposed specifications both for GSA and for other agencies to determine

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531788 0—60 2 11
their suitability for use by the Federal Government.

Cooperation with State and municipal governments is principally in the

field of weights and measures. Although the Bureau itself does not have regulatory powers, it contributes to the local bodies the means and methods

whereby measurements in commerce may be made in a uniform manner,

consistent with the national standards. A major medium of cooperation

is the National Conference on Weights and Measures. Thirty-nine States,

Puerto Rico, and the District of Columbia were officially represented at the

44th annual meeting of this Conference, held in Washington, D.C., June

8-12, under NBS sponsorship.

On March 3 standards of the fundamental units involved in commercial

exchange were presented to the new State of Alaska in a special program

held at the Bureau. Work was under way during the year to develop new

physical standards for the states that would be more accurate, constant, and

durable.

Through the participation of Bureau staff members in the work of professional societies and national standardizing bodies, the Bureau plays an active

role in the development of test methods and criteria, in the application of

scientific discoveries, and in fundamental research programs of a national

nature. During the past year Bureau staff members held about 1,592 committee memberships in more than 186 national groups such as the American

Society for Testing Materials, the American Standards Association, American Society of Mechanical Engineers, American Chemical Society, Institute

of Radio Engineers, and Instrument Society of America. In many of these

groups NBS staff members work with industry to improve engineering

standards, purchase specifications, and building and safety codes.

Two other important types of Bureau-industry cooperation are the Research Associate Plan and the donor program. Under the Research Associate Plan, technical, industrial, and commercial organizations can support

work at the Bureau on projects that are of special interest to them, yet are of

sufficient general interest to justify use of government facilities. These

projects must also be important from the standpoint of the Nation's sum

total of technological knowledge. The work is done by research associates

who are paid by the sponsor but otherwise function as members of the

Bureau staff. At the present time 12 groups are supporting research as- sociates at the Bureau (appendix 3.7)

.

The donor program was authorized in 1950 by Public Law 619 under

which the Bureau may accept funds for the purpose of furthering its work.

This arrangement permits individuals as well as technical, industrial, and

commercial organizations to support work at the Bureau when the results

are expected to be of value to the general public. During the past year, 18

projects were supported by gifts from 32 organizations (p. 147).

On an international basis, the Bureau represents the interests of the Government and American science in matters dealing with the establishment and

maintenance of standards and establishment of values for scientific constants.

Most of this work is done through participation in a large number of inter12
national groups such as the International Union of Pure and Applied Physics,

International Scientific Radio Union, International Commission on Illumination, and International Organization for Standardization. Approximately

100 staff members attended meetings of international societies during the

fiscal year.

In October 1958 the Director of the National,Bureau of Standards attended

a meeting of the International Committee on Weights and Measures at Sevres,

France. This Committee is an executive body of the General Conference on

Weights and Measures, which normally convenes only at 6-year intervals.

The Committee took an important and nearly final step toward achieving an

atomic definition for the meter, recommending to the General Conference

(which meets again in 1960) that the meter be defined in terms of the orange

line of krypton-86. The Committee also recommended a number of re- visions in the Treaty of the Meter, and that an international program be

established on standards for measuring ionizing radiations.

To secure identical values for the yard and pound in precise measurements,

an international yard and an international pound were adopted by agreement

between the directors of the national standards laboratories of six Englishspeaking nations: Canada, New Zealand, United States, United Kingdom,

South Africa, and Australia. According to the agreement, the international yard equals 0.9144 meter and the international pound equals 0.453

592 37 kilogram. On July 1, 1959, the Bureau began making all calibrations of length and mass (except those for the U.S. Coast and Geodetic Survey and those expressed in metric units) in terms of the international yard

and the international pound.

Another phase of international cooperation involves a program whereby

scientists or diplomatic repres ntatives from other countries are accepted at

the Bureau as guest workers or visitors. Approximately 900 foreign scientists and technicians, representing 50 countries, visited the Bureau during

the year. Twenty-eight of these visitors were specialists who came as guest

workers to spend from 1 to 12 months in cooperative research in such fields as radio propagation, free radicals, mathematics, and dental materials.

Eleven were trainees who were being prepared for leadership in the national

laboratories of their own countries.

Administrative Activities

Bureau programs are financed by four sources of funds: Direct appropriations from the Congress, transferred funds from other Federal agencies,

fees paid by private organizations for calibration services and standard

samples, and gifts from private sources. During 1959, the total funds obligated, including construction and facilities, were $34,839,000. Of this total, $12,379,000 came from the direct

appropriation for the Bureau's research and technical services and $2,709,000

from the direct appropriation for facilities and for the design of new laboratories. The remaining $19,751,000 came from other agencies and private

sources (see p. 138)

.

13
At the close of the year the Bureau's total staff was 3,425, of which 42

percent were in the professional categories. In the professional group

were over 500 physicists, 300 chemists, 250 engineers, and 100 mathematicians. Of the total staff, about 1,000 were stationed at the Boulder Laboratories and its associated field stations, 43 were in other field installations,

and the balance were in Washington, D.C.

A new research division was established in the Central Radio Propagation

Laboratory. The new Radio Communication and Systems Division will

expand the research and development services provided for agencies which

use radio communications. In particular, it will deal with research in radio

communication and navigation techniques, and the application of radio

propagation studies in the improvement of radio systems. The Division

will also be responsible for the coordination within the Boulder Laboratories

of the radio systems problems of other agencies, and for direct liaison with

these agencies in providing the services necessary.

In order to achieve greater coordination in the work of many projects

of closely related interest and in order to promote rapid progress in specially

designated research areas, the Bureau will appoint coordinators of interdivisional research programs who will have the following technical and

advisory responsibilities: (1) Definition of the area of research, (2) identification of staff to undertake the program, (3) increasing interdivision co- operation, and (4) reviewing and reporting on the program. The first

coordinator of such a program has been appointed in the field of plasma

and astrophysics.

During the year considerable progress was made in the design planning

of the new laboratories to be located at Gaithersburg, Md. By the end of the

year many of the Gaithersburg buildings were in the final stages of architectural drawing. Plans were substantially completed for the radiation

physics laboratory, including the new linear accelerator, and the engineering

mechanics laboratory, including the new million-pound deadweight force

measurement machine.

Dr. Robert D. Huntoon, Associate Director for Physics, was appointed

to the new position of Deputy Director of the Bureau. He serves as the

Director's alternate in representing the Bureau and exercises fully delegated

authority in the direction, coordination, and review of Bureau programs

and administration.

The passage of the Government Employees Training Act of 1958 provided

the Bureau with the opportunity to support additional training and education

for staff members to aid in meeting the changing and expanding technical

requirements of Bureau responsibilities (see appendix 3.6).

Programs Planned

At the close of the fiscal year, plans had been made for greatly intensified

effort in three critical areas: (1) High-purity materials, (2) plasma- and

astrophysics, and (3) very high pressure.

14
As science and technology move into unknown environments and new

applications of devices, new and better materials are needed to meet unusual

conditions. To enable other laboratories to satisfy these requirements without costly trial-and-error procedures, the Bureau must develop and publish

more data on the fundamental properties of materials. An important aspect

of this work on fundamental properties is the devising of techniques for

achieving extremely high purity in materials and criteria for determining

purity. Recognizing the need for a national program on high-purity materials, the Bureau plans to initiate a greatly expanded program in this field

during the coming year.

Many of the newer fields of technology—such as astronautics, ultrasonic

aerodynamics, thermonuclear power, and ionospheric communications

deal with a medium whose characteristics are very poorly understood: an

ionized gas, often at very high temperature, whose particles are continuously

interacting. The nature and behavior of such a gas, known as a plasma, constitutes a new and challenging field of physics which includes astrophysics,

fluid mechanics, and other disciplines. To this general field, the Bureau

has been contributing valuable data on atomic spectra, temperature and

radiation standards, and ionospheric and solar physics. However, many

laboratories working with plasmas have been forced to rely on expensive and

inefficient empirical methods because of a lack of precise measurement techniques and basic data on the fundamental properties of this gaseous medium.

To help solve this problem, an interdivisional group of scientists was established within the Bureau to plan and coordinate an intensive, unified program

in plasma and astrophysics. The program as planned falls naturally into

three parts: (1) Atomic properties, (2) gases near equilibrium or idealized

conditions, and (3) gases far from thermodynamic equilibrium. Parts (1)

and (2) will be carried on largely at the Washington laboratories, part (3)

will involve primarily the Boulder Laboratories.

The use of very high pressures offers considerable promise as a means of

developing materials to meet severe requirements in military and industrial

applications. Although the Bureau has been conducting research on high

pressure for some time, there is still a pressing need for a well-defined

pressure scale, standard measurement methods, and precise data on properties of materials at various regions on the pressure scale. The Bureau will

therefore begin in fiscal 1960 a special program to develop standards, measurement techniques, and data on properties in the very-high-pressure field.

Publications

The results of the Bureau's research programs are conveyed to the scientific and technological community largely by reports and publications.

Even when the work is developmental in nature—for example, the development of a specific instrument—the activity will culminate in a report, and

it is the report which will often prove of most value to Government, science,

and industry.

15
In the past year, the Bureau's publications program was reevaluated.

Effective July 1959, the Journal of Research of the National Bureau of Standards, the Bureau's main periodical, will be divided into four separately published sections. Corresponding to subject matter fields, the four sections

may be subscribed for individually. At the same time, the scope of the Journal will be broadened to cover the Bureau's scientific program even more

completely. The four sections will be : A. Physics and Chemistry, B. Mathematics and Mathematical Physics, C. Engineering and Instrumentation, and

D. Radio Propagation.

Two nonperiodicals, Circulars and Building Materials and Structures Reports, will be discontinued, and the type of material they formerly contained

will appear in the expanded Journal of Research. Two new nonperiodicals,

Monographs and Technical Notes, will be established. Monographs will consist of major contributions to technical literature which are too long for

publication in the Journal, and the Technical Notes will make available communications and reports which are of limited or transient interest.

Among the major nonperiodicals published during the year was NBS

Handbook 69, Maximum Permissible Body Burdens and Maximum Permissible Concentrations of Radionuclides in Air and Water for Occupational

Exposure, which set forth the latest recommendations of the National Committee on Radiation Protection and Measurements on this subject. Also

appearing was the eighth volume of Standard X-Ray Diffraction Powder Patterns, NBS Circular 539. This circular contains data needed for chemical

analysis by X-ray diffraction. One of the final issues of the Building Materials and Structures Reports Series was an updated edition of the Selected

Bibliography on Building Construction and Maintenance.

During the year, the Bureau's reports and publications totaled 1268, ex- clusive of calibration and test reports and of general administrative documents. Some 541 classified and unclassified reports were issued to other

government agencies, while 727 papers and documents were published

formally.

Of the formal publications, 85 were published in the Journal of Research,

and 484 in the journals of professional, engineering, and trade organizations.

There were 134 summary articles published in the Bureau's monthly Technical News Bulletin. Twenty-four papers were published in the nonperiodical series of publications : 2 in the Applied Mathematics series, 2 in the

Handbook series, 14 in the Circular series, 3 in the Building Materials and

Structures Reports series, and 3 in the Miscellaneous Publications series.

The other monthly Bureau publication, Basic Radio Propagation Predict

tions, which is published for a 1 -month period 3 months in advance, presented radio propagation data needed in determining the best frequencies to

use in long-range radio communications.

A list of publications for the fiscal year is given in the appendix, section

3.8 (p. 148).

16
2. Highlights of the Research Program

The Bureau's technical program is carried out through organizational

units called divisions. These are shown in appendix 3.1. A review of se- lected research and development programs is presented in this section under

headings corresponding generally to these organizational units.

2.1. Electricity and Electronics

The Bureau's work in electricity is primarily the development, improvement, and dissemination of the standards of measurement for electrical

quantities, and the study of the properties of materials that are important

in all applications of electricity and magnetism. The object is to provide

electrical standards that are constant over long periods of time, uniform

throughout the Nation, and consistent with the fundamental mechanical units.

The electronic activities include the standardization of test methods for

electronic components, the study of processes and materials for component

fabrication, and the establishment of optimum designs of electronic equipment for maximum life and reliability. Electronic development programs

are undertaken to meet the special requirements of the Bureau and, in areas

where the Bureau is uniquely qualified, those of other government agencies.

The demand for the calibration services by which the electrical standards

are disseminated throughout the Nation continued to increase and was about

25 percent greater than the preceding year. This demand was met without

accumulating a serious backlog. In addition, development of standards of

capacitance continued. Methods for using these standards, both in calibration of other capacitances and as a basis for the absolute determination of the

ohm, were developed. Measurements on instrument transformers were ex- tended to audiofrequencies with greater accuracy than in previous years and

have made possible improved calibrations of a-c potential dividers.

Several continuing basic research programs in the Electricity and Electronics Division are concerned with measuring the fundamental electrical

properties of materials. These include investigations of dielectric materials,

and methods of measuring the characteristics of electronic component parts

and such materials as mica.

Automatically Measuring High Resistance. Precisely measuring

resistors of extremely high values requires determining the current flowing

through the resistor into a capacitor whose value is continually changed.

Because the capacitor is adjusted manually, and because the test can be

long and tedious, the Bureau developed an automatic device to drive the

capacitor at the proper rate.

Computable Standard of Capacitance. Work has continued on a

capacitance bridge that makes possible capacitance measurements with a

precision of about one part in a million over the range from 1 picofarad

to 1 millifarad. The successful design of this experimental bridge led to the

17
construction of two of essentially the same type for the Bureau's calibration

services. To obtain an accuracy comparable with the precision, it has been

necessary to design and build a capacitance standard whose value can be

computed from its dimensions. Such a capacitor has been constructed and

tested. Tests so far seem to show that the computable capacitor can be

disassembled and reassembled, with a variation in its capacitance of no more

than one part in a million. It is believed that the capacitance is known to a comparable accuracy as its value depends only on the length of two 10-in.

gage bars.

Electron Devices Data Service. A revised tabulation of data on re- ceiving tubes has been compiled from the information available on coded

punched cards in the files of the Data Service and is being issued as an NBS

handbook.

At present there are more than 20,000 individual types of electron devices

manufactured by domestic and foreign manufacturers. As few users have

access to a complete library of manuals containing the information on these

devices, the Bureau's Electron Devices Data Service is making the technical

data on such devices readily available to technical personnel. These devices are cataloged mainly according to type number and major electrical

characteristics. Considerable data on devices manufactured in Europe and

Japan were recently added.

Ceramic Wafer Tubes. A ceramic electron tube readily adaptable to

fully mechanized production methods has been developed under sponsorship of the Navy Bureau of Aeronautics. These tubes are compatible with

the modularized electronic circuitry developed as part of the Project Tinkertoy program announced in an earlier annual report. Tubes have been produced in a commercial plant in pilot quantity. They are now being incorporated in complete modular circuit packages for a military application where

their reliability can be observed in actual use under extreme conditions of

shock, vibration, and temperature.

Methods for Testing Servo Motors. Servo motors have become of increasing importance in devices where precise remote control of motions is

important. At the request of a committee of the Society of Automotive Engineers, the various test methods in use by several manufacturers were

studied experimentally and the necessary precautions to insure concordant

measurements by each method were evaluated and reported to the committee.

As a result, agreement between the manufacturers within certain desired

accuracy limitations is now possible.

Dielectric Properties of Nylon. The electrical properties of poly (hexamethylene adipamide), 66 nylon, a useful dielectric, was studied intensively. The electrical measurements were made on desiccated samples in a

special cell designed for use at low temperatures. The dielectric constant

and dissipation factor were measured over wide ranges of frequencies and

temperatures. The values of dielectric loss factor obtained were lower than

any previously reported in the literature. Also, a normally present peak in

the loss factor was barely observable in the desiccated nylon samples. Indi18
cations are that this loss peak is not a property of the nylon, but of the water

remaining in the nylon. Measurements of the dielectric properties show the

existence of a relaxation process that is an intrinsic property of the polymer

and is characterized by an activation energy about 12 kilocalories per mole.

Preferred Circuits. The preferred circuits program, sponsored by the

Navy Bureau of Aeronautics, has continued with the development of new

circuits. Two supplements to the Preferred Circuits Manual were released

by the National Bureau of Standards. The original manual contained only

vacuum tube circuits, but in the supplements some transitorized circuits are

presented. Future supplements will increasingly emphasize transistor circuits in accordance with present-day trends.

Recording Spectroradiometer. A recording spectroradiometer was

developed to measure the ratio of the spectral light intensities of two lamps as

a function of light wavelength. By comparing a test lamp with a standard lamp, the machine can automatically plot this ratio over the visible spectrum in a few minutes. The process formerly required several hours when

performed manually.

Electronic Metrology. Calibrating length standards is a tedious and

exacting task when performed manually and research has been under way

to mechanize this process. An electronic technique was developed to sense

and record the number of light fringes observed during the motion of an

interferometer, and to detect an engraved line marking a length scale. Extension of these developments is expected to lead to a machine for calibrating

industrial and scientific line scales automatically.

Galvanic Corrosion of Metallic Silver. During the course of determining the faraday, the rate of corrosion of silver in certain aqueous solueral hours, is now performed automatically

in a few minutes over the visible spectrum.

Above: view of the strip chart mechanism

(page 19).

19
tions was measured. Silver does not undergo thermodynamic chemical

reaction with perchloric acid; thermodynamically, it may dissolve in some

solutions containing oxygen or go into solution as a result of galvanic cor- rosion arising from local anodic and cathodic areas on the silver surface.

The rates of these reactions are very low, and the corrosion current density

is extremely minute. An additional finding was that the corrosion current

density of silver in distilled water appeared to be nil.

Evaluating Storage Batteries, In recent years the use of industrial

trucks and tractors propelled by electric batteries has shown marked increase

in material handling in government warehouses. The Bureau has developed

standard test procedures for evaluating such motive power batteries for the

Navy Bureau of Supplies and Accounts. Two general procedures were used:

A simulated service test and a life cycle test. Methods were also developed

for testing such batteries under various rates of discharge, under vibration,

and under variations in temperature.

A special purpose simulator was designed to incorporate appropriate

procedures for evaluating storage batteries for use in helicopters. The

simulator is a self-contained unit that operates and records data with no

one in attendance. It consists of a programing device, discharge circuit,

charging circuits, a motor generator set, and instrument panels.

Dry Cell Specifications, A revision of specifications for dry cells and

batteries has been completed for the American Standards Association and

will be issued as an NBS handbook. New material in this specification includes data on cells and batteries for use with transistors, dimensions in

both the metric and English systems, cell designations adapted by the International Electrotechnical Commission, and standard terminal arrangements. The specification also includes performance data on flashlight cells,

radio batteries, telephone cells, railroad lantern batteries, hearing-aid cells,

alarm system batteries, photoflash cells, C batteries, and A/B battery packs.

International Comparison of Transformer Ratio Measurements,

The first international comparison of instrument transformer ratio measurements was made using four multirange transformers belonging to the

Physikalisch Technische Bundesanstalt. Test included current ratios from

1/5 to 10,000/5 amperes and voltage ratios from 3,000/100 to 230,000/100

volts. Accurate ratio and phase-angle determinations on such devices have to

be used not only for all large power and energy measurements, but also in

instrument laboratories, where they furnish an important part of the basis

for the precise determination of large alternating currents and voltages.

Such transformers of suitable construction provide ratio standards that are

known to be stable within a few parts per million. Also participating were

the National Research Council Laboratories of Canada; preliminary values

of ratios and phase-angles over the entire range of currents and voltages

show good agreement among the three national laboratories.

The first international comparison of instrument transformer ratio measurements was made using four multirange transformers belonging to the German Physikalisch Technische Bundesanstalt. Such transformers are used for

20
The largest of four standard transformers from the Physikalisch Technische

Bundesanstalt (the West German national laboratory) which were tested by

the Bureau. Ratio and phase-angle measurements were made as part of this

first international comparison of standards for alternating current and voltage

measurements. The United States, Germany, and Canada participated in this

program (page 20).

making accurate ratio and phase-angle determinations for large power and

energy measurements, and also in measurement laboratories where they

furnish an important part of the basis for the precise determination of

large alternating currents and voltages. Preliminary values of the calibrations or ratios and phase-angles over a wide range of currents and voltages

show good agreement among the three national laboratories.

2.2. Optics and Metrology

The Bureau's work in optics and metrology is principally concerned with

the development of standards for classical optics and for length measurement, and with the establishment of procedures for the precise use of these

standards. During the past year good progress was made in developing

atomic beam sources for standards of length, using the beams in both emis21
sion and absorption. In another approach, absorption in a magnetic field

"was employed to realize a wavelength standard of length that will be convenient for most laboratory applications. Research to improve line sharpness by interferometric filters resulted in line widths capable of producing

interferometric fringes with a path difference of 2,000 mm. in a Michelson

interferometer.

Among new photometric standards made available during the year were

lamps with frosted bulbs for measuring the luminous intensity of electric

lamps. These standards are more easily oriented for calibrations and

show less candlepower variation than the clear-bulb standards previously

issued. Three different investigations were facilitated with the aid of the

high-speed electronic computer used at the Bureau. They pertained to

optical systems design, interferometric calibration of gage blocks, and

color difference determinations.

Color Differences by High-Speed Computer. In order that rapid

determinations may be made of the color differences in large numbers of

samples over a wide range of materials, two formulas were programed for

the Bureau's high-speed electronic digital computer. Both programs begin

with the fundamental measurement of spectral transmittance or reflectance

of a sample color. One, for small difference computations only, is based

on the original NBS unit of color difference defined in 1942 in terms of

tristimulus values. The other, based directly on the Munsell scales of hue,

value, and chroma, may be used for any size of color difference. Color

differences between pairs of samples, the tristimulus values of which have

been derived spectrophotometrically, are obtained automatically in 5 seconds.

New Color Charts, In a recent color-measurement study conducted in

cooperation with the ISCC (Inter-Society Color Council), central notations

were determined for the ISCC-NBS color-name blocks. These blocks are

defined as segments of a spheroid, each segment encompassing the range of

color acceptable under one color name. Fitted together, the segments comprise the psychological color solid that scientists use to represent the gradations in color perceived by the human eye.

The central notations of the blocks were designated in terms of the Munsell

tridimensional scales, and paint-on-paper prototypes of the centroid color

of each block are being produced. When these prototypes are approved

as representative of the blocks from which they derived their color names,

they will be reproduced in color charts and published as a supplement to

NBS Circular 553, the ISCC-NBS Method of Designating Colors and a Dictionary of Color Names.

Lens Aberrations Measured. A visual method was developed for ac- curately measuring the longitudinal spherical aberration present in lenses.

Results obtained are comparable to those derived by the Hartmann photographic method, long considered the near ultimate in this type of work.

Prime advantages of the visual process are rapidity of measurement, and

the capability for measuring the logitudinal chromatic aberration of lenses

with a minimum of effort.

22
The psychological color solid, showing division into color-name blocks. The

centroid colors of these blocks are being produced for use by science and

industry (page 22).

Lens Distortion Measurements Refined, An extended investigation

of possible errors of adjustment in measuring lens distortion with the nodal

slide bench resulted in increasing the accuracy of these measurements by

a factor of 10. Values of lens distortion, formerly difficult to determine

more closely than to the nearest 20 microns, are now determined to the

nearest 2fx. In the course of this study, a visual method of measuring

prism effect of lenses was developed.

Lens Calibration Methods Analyzed. At the request of the Air Force,

an analysis was undertaken of the principal methods used in calibrating

lenses for airplane mapping cameras. Comparisons were made of the photographic method in which a lens testing camera is used, the visual method

with the nodal slide bench, and the visual goniometric method. All three

techniques assure high precision in photogrammetric lenses when proper care

is exercised in taking the measurements. Special caution must be observed

to avoid errors resulting from plate curvature, asymmetric use of apertures,

prism effect, and instrument misalinement.

Anticollision Lights for Airplanes. As long-range visibility becomes

increasingly important to aviation with the supersonic speeds attainable

today, the demand has grown for higher and higher intensity in the anticollision lights installed on airplanes. The Bureau, in developing information for the Navy Bureau of Aeronautics on the practical upper limits of

luminous intensity for these lights, designed and built a 2,000-watt rotating

assembly that produces 12,500 candles of red light. Actual flight tests,

however, indicated that the luminous output of the essembly was excessive

at times, principally because of atmospheric backscatter. An automatic hazeactuated device was therefore designed to lower intensity when backscatter

is objectionable and to raise it as the atmosphere clears.
Visual Landing Aids Devised, New lighting and marking systems

were designed for landing areas on land, on sea, and on aircraft carriers,

for the Navy Bureau of Aeronautics. One device, known as the approachbeacon system, is a simple, low-cost method of providing visual guidance

for circling and radio-range approaches to airfields during marginal weather

conditions. It consists of two or more approach beacons located on the

extended runway centerline. Installed on each beacon is an array of continuously burning incandescent lights which rotate about a vertical axis to

give the appearance of a rapidly flashing light. Another system consists of

miniature beacons placed at the corners of a runway or channel, which

serve to identify the landing area. A third system fills a need for circling

guidance lights. Although present runway lights provide ample guidance

to a pilot when he is alined with the runway, this system is designed to aid

him while circling the field preparatory to landing.

Photometric Equipment Improved. The basic unit of photometry

the unit of luminous intensity—is defined in terms of the luminance of an

ideal radiator (blackbody) immersed in freezing platinum. Although

actual radiators depart from the ideal, fairly consistent results in the measurements of photometric units are usually obtained between the various

international standardizing laboratories. However, recent investigations at

NBS indicate that this consistency resulted from the use by these laboratories

of almost identical blackbodies. In studying the effect of deviation from

ideal blackbody conditions in the calibration equipment at the Bureau, three

correction factors were found necessary: One for the size of the opening

at the top of the sight tube which encloses the blackbody; the second, for

temperature drop in the walls of the sight tube ; and, the third, for that part

of the tube not immersed in platinum. When the corrections were made, a

significant improvement in consistency over previous measurements was

obtained, with results agreeing to well within 0.1 percent.

Bearing Ball and Cylinder Measurements Improved. Increased

accuracy in measuring steel balls for bearings of the type used in the highspeed gyros of guided missiles was achieved. High-quality steel balls were

measured with the repeatability of 2 millionths of an inch, representing an

accuracy in the measurement of about 5 millionths of an inch. The balls

were placed between steel plates and measured under varying loads by optical

interference and corrections were applied for indentation of the plates.

Similar measurements were made on cylinders for piston-type pressure gages.

Check measurements with the National Physical Laboratory in Great Britain

show agreement to 5 millionths of an inch, confirming the accuracy attained

by both laboratories.

Interference Fringe Path Extended. An interferometer may be used

as a monochromator to transmit a range of wavelengths much less than that

corresponding to the original width of the spectral line producing the radiation. This is particularly desirable for length measurement because it in- creases the distance over which interference may be obtained. For this pur24
pose the use of a Fabry-Perot interferometer with spherical plates is advantageous because it transmits more radiation than one with plane plates.

During the past year a spherical interferometer was constructed with which

interference fringes were obtained and photographed using a Michelson

interferometer with a mirror separation of one meter. The original source

of the light was the green line of mercury-198.

Research on Improved Lightwave Eength Standards, In investigating methods of producing an improved wavelength standard of length, the

Bureau has had success in two promising approaches. One is the atomic

beam, which can be used as either an emission or an absorption source, and

the other is the Zeeman absorption filter. By producing extremely narrow

spectral lines, both of these approaches can increase precision far beyond

that presently required by research and technology.

The precision possible with previously developed lightwave standards is

limited by Doppler broadening of spectral lines, an effect due to the random

motion of emitting atoms toward and away from the observer. Atomicbeam techniques decrease this effect by selecting atoms traveling at right

angles to the line of sight. The atomic beam has proved satisfactory in both

emission and absorption devices for producing very narrow spectral lines.

In both cases the half-width of a line is 0.002 cm"

1

, one-sixth of the width of

the proposed international standard. The action of the Zeeman filter depends

on the splitting of spectral lines in a magnetic field. The absorption characteristics of this cell act as a filter, and radiation is passed only by the

Atomic beam principle (left) used by the Bureau to produce narrow emission

lines in research on improved wavelength standards of lengths. A collimated

beam of mercury atoms emerging from the oven (below white box in photo)

is bombarded by electrons. The atoms thus excited emit light which is then

viewed at right angles to the motion of the atoms in order to reduce Doppler

broadening (page 25).

25
region where absorption does not occur. With this apparatus a mercury line

0.006 cm-1 wide was obtained.

Lens Design by High-Speed Computer. To assist in the design of

optical lenses requiring aspheric surfaces, a ray-tracing program for the

Bureau's high-speed electronic computer was modified to include a subroutine for tracing rays through an aspheric surface. Another new routine

in geometrical optics permits the automatic calculation of the center and

diameter of a circle containing 30 percent of the total number of points

in a spot diagram. This program may also be used to provide image heights

from which the distortion of an aerial camera lens can be calculated at the

estimated plane of best focus for a number of aperture openings. The method

followed in predicting distortion appears to be superior to the customary

procedure in which the height of the principal ray is compared with the

ideal image height.

A preliminary program for SEAC (the Bureau's electronic automatic

computer), in which spot diagrams are produced and focused on the face of

an oscilloscope, was successfully run. A permanent program compatible with

the tape output of a commercial computer is being prepared to speed up lens

design. It is designed to eliminate the use of a plotting machine, and also

the need for estimating the plane of best focus prior to calculating spot

diagrams. In addition, the use of a direct photographic process enables

superimposed points to be distinguished from a single point, thus giving

a much more accurate representation of the distribution of energy in the

image than can be obtained at present.

High-Precision Gage Blocks. As improved gage block materials become available (see p. 75), measurement techniques are being refined for

measuring the stability of these blocks. During the past year, more than 70

samples submitted by the metallurgy laboratory for testing were measured

at regular 1-week, 4-week, and 6-week intervals. Work in this area included

periodic absolute interferometric measurments of a master control block,

interferometric comparison of selected sample blocks with the master block,

and mechanical measurement of the thermal coefficient of expansion and

length changes of all stability standards.

Advances in Refractometry. The refractive index of a sample of

arsenic trisulfide glass was determined at different temperatures for selected

wavelengths in the spectral regions of the ultraviolet, visible, and infrared.

After thermal coefficients of index were derived at each wavelength, a Sellmeier-type dispersion equation was fitted to the averaged data, and comparisons were made with the indices of refraction in the visible region that

had been obtained for two other samples. A study was also made to obtain

preliminary refractive index and dispersion data on a synthetic barium

fluoride crystal from 0.25 micron in the ultraviolet to 11 microns in the

infrared. These data are valuable to designers of optical systems, spectroscopists, solid state physicists, and in the military application of infrared

technology.

26
In work for the Navy Bureau of Ordnance, lightweight optical glasses were

developed at NBS with high refractive indices and high dispersion. These

glasses are especially suitable for military applications where weight is of

prime importance.

Chemistry of Photographic Fixation, A better understanding of the

chemistry of photographic fixation and the factors affecting the permanence

of photographic records was obtained from a study of the silver sulfide in

photographic images. It was found that some of the silver in a developed

photographic image is converted to silver sulfide during the fixing process.

A quantitative procedure was developed for reducing silver sulfide in an

image to silver so that the sulfide can be measured easily in terms of the

optical density of the silver deposit.

New Candlepower Standards, The Bureau recently made available

new photometric standards for measuring the candlepower, or luminous

intensity, of electric lamps. They consist of 100-, 300-, and 500-watt lamps

with inside-frosted bulbs, monoplane filaments, and medium-bipost bases.

These lamps are easily oriented on the photometric bar by means of the bipost bases, require no diaphragm when in use, follow closely the inverse

square law, and are superior in the amount of candlepower variation they

show with change in orientation to the clear-bulb lamp standards previously

issued.

Records Reduction, To assist the Veterans' Administration in reducing

the volume of medical records, a study was made of the factors required to

design microcopying systems for such records. The significant graphic features of electrocardiograms, charts, and written matter were measured.

Based on these measurements, designs were specified to provide a photographic system capable of the greatest reduction in size which at the same

time retained the essential informational content of the original records.

Interferometer for Large Surfaces, An instrument was developed to

facilitate the testing of precision flat surfaces such as aircraft fixtures,

machine ways, and layout plates. The device is a simple, sensitive interferometer which examines surfaces by producing a set of interference

fringes, which is, in effect, a contour map of the test area. Areas of any

length can be tested by merely adjusting the angle of incidence of the light on

the surface. The width of the area examined at each setting is always equal

to the linear aperture of the instrument. This development, by insuring

the flatness of surfaces on which precision machine parts are compared, is

expected to aid materially in the control of dimensional tolerances.

Filter and Brightness Standards, Among the numerous standards

issued during the past year were red filter standards and brightness standards for calibrating the instruments used throughout the aviation industry in

the measurement of military airplane instrument lighting panels. With the

aid of these, standards instrument panels can be made bright enough to be

adequately legible, but low enough in emission of shortwave visible energy

not to impair the dark adaption of the pilot.

531788 O—60 3 27
One of the new 100-watt candlepower standards is adjusted on a photometric

bar for calibration. The new frosted-bulb standards have proved superior in

many respects to the clear-bulb lamp standards previously issued (page 27).

2.3. Heat

Advances in science and technology constantly necessitates determination

of temperature with increasing accuracy and extension of measuring techniques to higher and lower temperatures. To provide a basis for precise

measurement of heat, the Bureau maintains temperature scales from the

lowest to the highest accessible temperatures, and continuously develops and

extends these scales. In addition, standards are developed for other heat

measurements such as thermal diffusivity, heat capacity, heat of combustion,

viscosity, and fuel kinetics.

A broad program of basic research in related critical areas is being conducted to extend these standards. Special emphasis is given to basic studies

in standards of temperature measurement, heat measurements, statistical

28
thermodynamics, molecular structure, high-pressure thermodynamics, lowtemperature physics, rheology, and high-temperature processes.

During the past year, these activities were characterized by efforts to obtain

new extremes of temperature and pressure, to increase the degree of automation of precision measurements, to extend knowledge of the statistical

thermodynamics of dense systems, to investigate the rheological properties

of selected materials, and to study the mechanisms of high-temperature

processes with greatly improved instrumentation. A broad investigation

was initiated on the thermodynamic properties of compounds composed of

light elements, and an intensive 3-year program on the behavior of solids

containing trapped free radicals will be completed shortly.

High-Temperature Resistance Thermometry, Since the adoption

of the International Temperature Scale in 1927, the platinum versus platinum-10 percent rhodium thermocouple has been the standard instrument

used for interpolation between fixed points on the scale from 630.5° to

1,063° C. Because factors inherent in the thermocouple itself and in its

use limit the accuracy to about 0.2 or 0.3 deg a better thermometer is

needed for accurate temperature measurements in this range.

The unsatisfactory performance of resistance thermometers at high

temperature has generally restricted their use. However, the Bureau has

designed a suitable resistance thermometer using high-temperature materials.

The availability of exceptionally high-purity platinum and high-purity synthetic sapphire (aluminum oxide), which is used as a supporting material

for the resistance coil, has made possible this development. The high-purity

form of aluminum oxide has the required electrical properties and stability

at high temperature and at the same time does not contaminate the platinum.

Although not all of the difficulties associated with high-temperature re- sistance thermometry have been completely overcome, the platinum resistance

thermometers recently developed appear satisfactory for the range 630.5°

to 1,063° C. Studies are being continued on the effect of various protecting

tube materials over long periods, and on the stability of the thermometers in

different atmospheres.

Pyrometer Symposium. To facilitate the exchange of information and

ideas on high-temperature pyrometry, a Symposium on the Optical Pyrometer Temperature Scale was held at the Bureau in October 1958. The theme

of the symposium, which was sponsored by the Bureau and the Argonne

National Laboratory, concerned research on present temperature scales and

calibration practices, recent improvements in optical pyrometer techniques

and instruments, and the possible use of the temperature scale beyond

4,000° K.

In the past few years, the interest in high-temperature measurements has

created a demand for optical pyrometers capable of greater accuracy. This

need has raised many questions about procedures for realizing the International Temperature Scale at high temperatures above 1,063° C, and about the

calibration, use, and manufacture of optical pyrometers. The symposium

gave the users of optical pyrometers in various laboratories an opportunity

29
Above: Temperature sources used in calibrating optical pyrometers. A tungsten ribbon-filament lamp (center) provides brightnesses corresponding to

temperatures up to 2,400 °C. Calibrations are made at 2,800 °C with a zirconium arc (left) and at 3,800°C with a carbon arc (right). Below: Temperature resistor of platinum resistance thermometer developed for use from

630.5 °C to 1,063 °C. It is designed to provide more precise measurements

than are possible with thermocouples now in use (page 29).

to meet with Bureau staff and technical representatives of the pyrometry

industry, to exchange ideas, and to discuss problems associated with the

calibration and use of the instruments.

Precise Measurement of Shock-Wave Velocity. Investigations are

being conducted to utilize the high temperatures existing in shock waves

to study the kinetics of reactions occurring in very short periods of time.

Thus far, the effort has been devoted predominantly to improvement of the

accuracy of methods for determining the velocity of a shock wave, from

which the temperature may be calculated.

The sensitivity of detectors for the passage of moderate-strength shock

waves in low-pressure gases has been considerably increased by an improved

method for preparing thin semiconducting films. Nickel oxide is deposited

on glass by a sputtering technique, and the deposit is aged to increase the

surface resistivity and the negative temperature coefficient of resistivity.

With this method, surface resistivities of approximately 50,000 ohms/square,

with negative temperature coefficients of 1.5 percent/deg C are attainable.

Thermal response times for detectors utilizing these nickel oxide films are in

the order of one microsecond. This quick response enables a more accurate

determination of the shock temperature.

30
LoW'Temperature Thermometry. In solid-state physics, as well as in

some branches of chemistry, a large amount of research is carried out in the

liquid-helium region (1° to 5° K). The success of physical research at low

temperatures is dependent upon accurate measurement of temperature.

Because the International Scale is defined only down to 90° K, there is a

pressing need for a sensitive and reproducible secondary thermometric

standard for measurements below 90° K.

To meet this need the Bureau is developing a sound-velocity thermometer

based on the velocity of sound in helium gas. A method was developed to

make accurately reproducible measurements in the normal helium region,

which—because of large temperature gradients and thermal fluctuations

was not possible before. In an extensive study on the behavior of carbon

resistors, certain carbon resistors were found to be reproducible to within

0.001 deg, even after repeated cycling between 4° and 100° K. Such high

accuracy is needed because the temperature of a dependable isothermal

liquid helium bath should be kept within this limit. However, the reproducibility is not maintained if the temperature of the liquid falls below the

"lambda point," i.e., if the superfluid phase of the liquid helium is produced.

It is speculated that this effect may be connected with penetration of the

liquid into microscopic channels within the resistor. Further investigations are in progress.

Viscosity Standards and Measurements, Almost all determinations

of viscosity of liquids are made indirectly with instruments which must be

calibrated using liquids of known viscosity. A widely accepted calibration

standard of liquid viscosity is water at 20° C and 1 atmosphere.

A proposal for the formal adoption of water" as a calibration standard

was circulated to all member countries of the International Organization for

Standardization. Included with the proposal was the suggestion that the

viscosity of water (at 20° C and 1 atm) be set at 0.01002 poise, as measured

by the Bureau a few years ago.

Although the groups representing most member countries agreed with the

proposal, the members from the USSR have objected to adoption of this

value. They have submitted reports claiming that water saturated with air

has a slightly different viscosity than air-free water. However, no significant

difference in the viscosity of air-free and air-saturated water has been detected in measurements at the Bureau. Analysis of the Russian reports has

raised several questions regarding various aspects of their measurements.

These questions are being formulated for transmission to the Russian

workers.

Concurrently with this analysis, work is being continued on the development of methods for absolute measurement of viscosity. When a suitable

method is developed, it should be possible to redetermine the viscosity of

both air-free and air-saturated water in the absolute fashion with sufficient

precision to settle the problems.

31
Significance of Spectroscopic Measurement of Flame Temperature. The development of jet engines and gas turbines has led to the need

for basic research on the physical and chemical processes occurring in hot

gases and on methods of temperature measurements where usual procedures

fail. Detailed spectroscopic studies on well-controlled systems provide the

basic information required in this field as well as in upper-atmosphere

chemistry and physics, and in chemical kinetics.

Under certain conditions, spectra emitted by excited OH free radicals in

flames show the existence of radicals with abnormally high-rotational energy,

indicating a temperature as high as 10,000° K. However, the heat released

in burning is sufficient to produce a thermodynamic temperature of only

about 3,000° K in these flames. Results of this kind have presented a puzzling contradiction for some time, since molecules that have such an excess of

rotational energy are known to lose this energy easily in collisions with other

gas molecules at lower temperature. In a program sponsored by Wright Air

Development Center, the Bureau has resolved this contradiction by demonstrating the existence of a quenching collision process which removes energy

from excited OH molecules in the flame so efficiently and quickly that they

do not have time to bring their rotational energy into equilibrium with the

rest of the flame. Thus the molecules from which emission of light is observed have not had time to interact with other molecules in the flame gases,

and the temperature deduced from the OH emission spectrum is not characteristic of the temperature of the flame as a whole.

In these spectroscopic experiments, a flame is illuminated with light which

is absorbed by OH radicals in it, and the amount of light reradiated by these

radicals is measured. It is found that only a few percent of the absorbed

light are reemitted, indicating that most of the excited radicals are deactivated

by quenching collisions.

Thermodynamic Properties of the Light Elements. In connection

ivith research on the properties of materials, light-element compounds—important as efficient sources of energy—are presently receiving concentrated

attention. Applications for the data may be found in rocket development as well as other defense and industrial fields. Very little basic information

exists on the light elements and the little which has been determined does not

extend to the high temperatures and pressures necessary in practice.

To fill this need, a comprehensive interdivision program of experimental

and theoretical work has been initiated on lithium, beryllium, magnesium,

and aluminum—in free form, and in combination with hydrogen, oxygen,

nitrogen, fluorine, and chlorine. (See 2.9, p. 83.) The objective of the

program, sponsored by the Advanced Research Projects Agency is to secure

fundamental thermodynamic properties of the light element compounds.

Knowing these properties, the energies and equilibrium properties of the

mixtures of these substances can be determined with an accuracy of one percent in solid, liquid, and gaseous phases. It is hoped that this accuracy

will be possible in the temperature range from 0° to 6,000° K and in the

pressure ranges from 0 to 100 atm. The following methods are being

32
employed for the investigations: Fluorine calorimetry, thermochemistry,

low- and high-temperature calorimetry, halide equilibria, statistical thermodynamics, digital computing techniques, spectra and molecular structure,

thermodynamics of refractory substances, and chemical preparation and

properties of hydrides. Exploding wire techniques also are being explored

to obtain data at the higher temperatures and pressures.

Nitrogen—Fluorine Bond Energy. Chemical oxidizing agents were

investigated which have special properties, such as large heat of reaction per

unit weight or per unit volume, and safe and convenient handling properties.

Compounds in which nitrogen is bound to fluorine are of particular interest

in this connection because the relative weakness of the chemical bonds between nitrogen and fluorine, and the great strength of bond which these elements can form in other combinations offer opportunity for liberation of

large amounts of energy in suitable reactions. However, the value of the

N-F bond energy has not been known with certainty because of limited and

apparently conflicting data on the subject, and hence, estimates of reaction

energies have been unreliable.

A calorimetric study of the bond energy was successfully completed for the

Navy Bureau of Ordnance. From the study of the reactions of nitrogen

trifluoride with hydrogen and with ammonia, results indicate the bond energy

in nitrogen trifluoride is approximately 66.4 kcal/mole. This work is being

extended to other compounds containing N-F bonds to determine the variation of the bond energy in different molecular environments.

Physicochemical Processes in Flames. As part of a basic research

program on the physicochemical processes of flames, the spectra of representative fluorine flames are being investigated to establish the structure,

fundamental constants and properties of fluorine, and related halogen compounds. For the first time, the vibrational rotation spectra of HF in a

fluorine flame have been studied with a high-resolution, grating spectrometer.

Despite the formidable experimental difficultes in operating such flames

under conditions suitable for spectroscopy it has proved feasible to record

the emission over a very wide spectral range and to maintain steady flames

for periods up to one day. Because the flame is extremely hot (4,000° K)

a large number of hitherto unobserved transitions at high temperatures

could be recorded and used to obtain new and highly precise molecular

constants.

Statistical Thermodynamics. The development and application of

theoretical methods has greatly accelerated in describing and computing

thermodynamic and related properties of gases, liquids, and solids. While

work in the statistical theory of many natural phenomena which involve

time-dependent properties of matter has been increasing, the basic principles are not yet well understood. For this reason the Bureau is attempting to

increase knowledge of these principles.

Modern methods for solving "many-body" problems have been applied

to a variety of situations such as the equilibrium behavior of a fully ionized

plasma in a magnetic field. Modifications which are necessary in a theory

33
of transport for plasmas because of long range coulomb interactions have

been studied. Progress has been made in the description of the low-temperature properties of Bose systems and in the characterization of condensation

phenomena using recently developed graph and summation techniques. A

study of the fundamental bases of statistical mechanics has been carried

out on methods of forming ensembles and the fluctuation dissipation theory

has been used to describe relaxation processes in systems subjected to

nuclear magnetic resonance.

A collection of approximately 20 high-speed digital computation programs

has been developed and is in use for the preparation of tables of properties

of gases, liquids, and solids. Using this method, hundreds of pages of

thermodynamic properties of dissociated and ionized gases are computed

readily. Tables of this kind have immediate application in pure and applied

research, and in the design and development of power, propulsion, and

other devices. Tables of thermodynamic properties of air and its principal

constituents are in preparation over the temperature range of 2,000° to

20,000° K and pressure range of 10 to 10"6 atmospheres.

The Nature of Superconductivity. To understand the nature of superconductivity, the Bureau is studying the equilibrium mixtures of normal

and superconducting regions in superconducting metals.

For a superconducting material which distorts an applied magnetic field,

an "intermediate state" becomes possible. In this state, the metal consists

of a complex structure of neighboring superconducting and normal regions.

This structure exhibits a definite periodicity—that is, the superconducting

and normal regions recur at specific intervals. Recent theories have introduced the concept of a "range of order" in the superconducting state. These

theories suggest that the specific arrangement of the regions is closely

related to the atomic scale interactions between the electrons of the superconductor.

VACUUM PUMP

RADIATION SHIELD.

V P TUBE

V P TUBE

(open end tube)

DIFFERENTIAL

OIL MANOMETER

HELIUM STORAGE DEWAR

Scientist checks the vapor pressure

in a nearly constant-temperature

liquid helium bath developed as part of a project to establish an

absolute temperature scale in the

range 2° to 20 °K. The vapor pres- sure must be accurately controlled

in order to achieve reproducible

temperatures (page 31).

34
The periodic structure is associated with a varying magnetic intensity

near the surface of the specimen which may be detected with a bismuth

probe. Since the regions are only a few tenths of a millimeter long, it is

necessary to use extremely minute probes.

Data for tin cylinders of various diameters and degrees of crystal perfection have been obtained. The results are in qualitative agreement with

some aspects of the theory but also demonstrate the inadequacies of the

theory in other respects.

Compressibility of Polymers. As part of a program to establish a

relationship between rheological properties and structure of materials, the

compressibility of polymers is being investigated. A study of the effect of

pressure, temperature, and frequency on the dynamic compressibility of a natural rubber-sulfur formulation has been completed. The dynamic compressibility, which includes both the elastic and viscous response to an alternating hydrostatic pressure, shows a typical relaxation behavior as the material goes through the transition from a rubbery to glassy phase. That is,

the system requires an observable length of time to respond to sudden changes

of force applied to it. Since the glass transition appears to be closely associated with a kind of

free volume available to the molecules of the system, the relationship between

the temperature, pressure, and time-scale (i.e., reciprocal of the angular frequency) at which it occurs should assist in a better understanding of the

phenomenon.

A 12-percent natural rubber-sulfur compound was chosen for investigation as one which should be fairly typical of rubberlike behavior and which

would have a transition in an experimentally accessible range. The measurements of compressibility covered —25° to +75° C, 1 to 1,000 atmosphere, and 50 to 1,000 cycles per sec. As expected, the transition temperature shifts with pressure as well as with temperature, increasing at the rate of

about 0.025° C per atmosphere. It is now possible to present a single re- duced curve which includes the effects of both temperature and pressure.

Reaction of Chlorine Beams With Nickel at High Temperatures.

Studies of chemical reactions between gases and metals at high temperatures

can provide information which not only is of great value in understanding

surface phenomena, but also has important applications in many phases

of high-temperature engineering. Current research in this area, under the

sponsorship of the Atomic Energy Commission, includes molecular-beam

experiments in which a collimated beam of gas strikes a hot-metal surface.

The gas and metal interact to form gaseous reaction products which are

directly analyzed in a mass spectrometer placed near the reaction site. The

thorough control of reaction conditions achieved with the molecular beam

plus the sensitive and specific nature of mass spectrometric analysis make

these experiments an excellent source of detailed information on high-temperature surface reactions.

An examination of the chlorine-nickel system between 1,150° and 1,650°

35
K indicates a rapid reaction rate proportional to the chlorine-beam intensity. NiCl and NiCl 2 , which are both formed on the nickel surface rather

than in gas phase reactions, have been identified as reaction products. NiCl

is the only product above 1,430° K, while at lower temperatures the dichloride

appears at a rate increasing with decreasing temperature, thus becoming

the predominant product at the lower end of the temperature range covered.

In these investigations, particular emphasis is being placed on the type of

adsorption process associated with the reaction and on the dependence of

chemical rates on the physical constitution of the metal's crystal surface.

By using single crystals, the relative reactivity of the principal crystal planes

of nickel are being studied.

Free Radicals Research Program. The 3-year program of basic re- search on the properties of solids containing trapped reactive species is now

approaching its planned termination. This program was established in

October 1956 as a cooperative venture among government, industrial, and

university laboratories with financial support from the Department of Defense. The work of the past year was characterized by the completion of

the numerous experiments, and the determination of preliminary results.

These experiments and results can be considered under the main categories:

Identity and concentrations of trapped species, nature of the solid containing

the trapped species, and reactions of the trapped species in the solid.

Spectroscopic investigations have been carried on over the wavelength

range from the infrared to the vacuum ultraviolet and various trapped species

such as N3 , NH, NH2 , and possibly also 0

+

2 , have been identified. For the

first time, OH in the gas phase was detected by electron spin resonance.

Methods of determining the concentration of trapped radicals, such as magnetic susceptibility and electron spin resonance, have been successfully

applied. These measurements resolved some of the earlier discordant re- sults and confirmed that the concentration of radicals trapped in solids at low

temperature is definitely less than 1 percent, and probably less than 0.1 percent. These results are of particular importance because of the possible

use of trapped radicals as a source of energy.

X-ray absorption measurements were used to determine the rate at which

gas molecules condense on a cold surface, thus giving clues to the mechanisms of the deposition process of solids containing trapped radicals. To

supplement X-ray data, electron diffraction methods were applied for the

first time. The X-ray patterns, used to define crystal structure, were obtained from thin films of solids such as nitrogen, condensed at 4° K from

the gas phase. Numerous other properties are being determined. For ex- ample, the index of refraction of condensed gases has been measured at

4° K. This type of measurement, coupled with the independent determination of the dielectric constant of these materials, has given useful structural

information. A fairly precise measurement of the thermal conductivity of

nitrogen films condensed at 4° K has indicated an unexpectedly large

variation in thermal conductivity, depending on the conditions under which

the solid was formed.

36
This apparatus is typical of many developed to provide new data on the production and properties of free radicals during a three-year program now nearing

termination. It is used to study the light emitted by free radicals produced

in oxygen rare gas deposits by electron bombardment. A spectroscope is being

focused on the cold surface where the free radicals are trapped (page 36).

Much of the research in the Free Radicals Research Program involves

low-temperature chemistry. The development of a liquid-helium Dewar

vessel which can be rotated at 3,000 revolutions per minute while under

vacuum and at 4° K has contributed to these studies. Investigations on

chemical reactions occurring in solids at these temperatures have been pursued through a variety of techniques. Perhaps the most informative has

been the addition of hydrogen atoms to films of condensed substances. The

initial work along these lines—the reaction of hydrogen atoms with solid

olefins at 77° K—has recently been extended by reaction studies at even

lower temperatures. In particular the observation of a reaction between

hydrogen atoms and oxygen molecules at 20° K indicates that the H02 mole37
cule may be trapped in the process. Reactions produced in solids at very

low temperatures by electron bombardment have also been investigated.

(For other free-radicals work, see p. 74, 86)

.

2.4. Atomic and Radiation Physics

Progress in such fields as civil defense, medicine, biology, and space

technology depends strongly on advancements in atomic research. This

application of basic discoveries to practical problems places an ever-increasing demand on the Bureau for information and services. To meet this

demand, efforts are concentrated primarily on providing more detailed and

reliable data on the properties of radiation, atoms, nuclei, and subatomic

particles, and the various interactions they undergo. Research tools such

as spectroscopy, solid-state physics, and bombardment studies are used to

probe the behavior of particles and radiation.

In addition to providing a clearer understanding of radiation and nuclear,

atomic, and subatomic particles, the research leads to new and better ways

for control and measurement. Complementary work, which follows directly

from the data obtained in basic studies, is aimed at developing new kinds

of standards and improving the accuracy of existing standards.

Spectroscopic Research* Analysis of the light emitted by excited

atoms is a widely used method for obtaining information on atomic structure.

The Bureau uses this technique to derive atomic energy levels and configurations for individual atoms. These data are in constant demand by physicists, chemists, spectrographers, and astronomers. Some of the most recent

work in this area was done on hafnium. By observing the spectra emitted

by this element in a microwave-excited quartz tube, 6,200 lines were ascribed

to hafnium. Similar excitation sources were developed for studies on the rare earth elements. Ytterbium is presently being analyzed by spectroscopic

techniques.

A description and analysis of the first spectrum of iodine was also completed, and work on the second spectrum of iodine and the first and second

spectra of tantalum is well under way. Further observations were made of

the complex spectrum of neutral thorium atoms in the far infrared. Studies

of the effect of a magnetic field on this spectrum have led to the discovery

of 150 new energy levels.

The wavelengths of spectral radiations are usually measured in the earth's

atmosphere, but to derive atomic or molecular energy levels, it is necessary

to convert them to vacuum values. For this purpose a new Table of Wavenumbers has been prepared. It gives, with high accuracy, the index of

refraction of the atmosphere, change in wavelength, and the number of

waves per centimeter in vacuum of any wavelength from 2000.0000 A to

1 mm measured in air.

Work is also under way to provide a table of the relative intensities of

the spectral lines of 70 elements under standard conditions. The results

of a new calibration of the copper arc reference standards have been applied

38
This high-resolution infrared spectrometer provided data for the calculation

of previously undetermined molecular parameters (page 40).

to more than 10,000 lines in the interval 2400 to 3300 A to obtain accurate

intensities.

Rydberg Constant Confirmation, The presently accepted value for an

important atomic connective, the Rydberg constant, was recently substantiated through spectroscopic studies at the Bureau. The confirmation re- sulted from an examination of earlier work which gave a value in conflict

with the Rydberg constant in use today. The error in the earlier determination was found by the Bureau to be in the value used for the 5016 A line of

helium, the reference for measuring the transitions which form the basis for

the Rydberg calculation.

Precise interferometric measurements were therefore made for nine strong

He I lines relative to two accurately known lines of mercury- 198. The wavelength of the 5016 A line was found to be 5016.6782 ± 0.0003 A in air. This

value was used in reevaluating the earlier calculations of the Rydberg constant, bringing the value into line with the one presently in use. This constitutes, in effect, an independent confirmation of the Rydberg constant,

which since 1952 has been based on the work of only one set of observers.

Astrophysics. An analysis was made of data on the spectrum of Jupiter, obtained at Mauna Loa, Hawaii, in 1957. Results include the first detailed measurements of the structure of the NH3 and CH4 bands in the red

region of the spectrum, and verify the presence of H2 and of a more complex

molecule, probably N2 04 , in Jupiter's atmosphere.

Attention has also been devoted to the preparation of a new manual of

solar spectrum wavelengths. This project is being carried on in collaboration with the Utrecht Observatory in the Netherlands, at the request of the

International Astronomical Union. Revised identifications of atomic and

39
molecular lines will be included, as well as excitation potentials and other

data on atomic lines in the solar spectrum.

To supplement the basic data on quantum structure already available in

the volumes of Atomic Energy Levels, tables of "multiplets" are being prepared. These tables include observed laboratory wavelengths and intensities,

excitation potentials, and term designations for the lines of individual

spectra.

High-Resolution Infrared Spectrometer. An improved grating spectrometer capable of extremely high resolution in the infrared was put into

operation. This instrument can resolve the fine structure of previously un- resolved infrared bands. This provides a means for investigating larger

molecules in the infrared and for determining molecular constants. The

spectrometer proved successful in separating the components of overlapping

bands such as those of atmospheric water vapor and ammonia. It was also

used to measure the spectrum of methane in a program conducted for the Air

Force and to measure the spectra of deuterated methanes and deuterated

ammonias in work for the Atomic Energy Commission.

Radiometry. To provide an absolute standard for ultraviolet radiation,

the Bureau built a graphite blackbody, which it is presently calibrating.

This blackbody can withstand very high temperatures and is therefore capable of emitting measurable amounts of ultraviolet radiation. The successful

development of such a radiator suggests that the radiation standard for the

ultraviolet spectral region can at last be placed on a fundamental basis.

A series of precise measurements on the wavelengths of infrared bands

was also carried out to provide reference standards in this spectral region.

This work was done in cooperation with the International Commission of

Molecular Spectroscopy.

Solid-State Research. To help provide data needed for the effective

application of semiconducting materials, the Bureau conducts a broad program of solid-state research. During the past year emphasis has shifted

somewhat from the intermetallic compounds to the oxide semiconductors.

For example, the electrical conductivity, Hall effect, and thermoelectric

power of titanium dioxide were measured over a wide temperature range.

From these electrical property measurements it was possible to obtain information on the conduction mechanism in the single crystal samples studied.

The behavior of the third electrons was found to constitute a borderline case between the band conception and the localized level model. Other studies on

titanium dioxide include optical absorption, photoconductivity, paramagnetic resonance, magnetic susceptibility, and dielectric constant and losses.

During an Air Force-sponsored investigation of carrier lifetimes in semiconductors by means of photoconductive and photo-electro-magnetic effects,

it was found that these phenomena are sometimes overshadowed by thermal

effects. An important parameter involved in such cases is the thermal diffusivity. The Bureau found that efficient methods for measuring this quantity can be based on the determination of the a-c bolometric and Nernst

effects. These methods are applicable to small samples and therefore con- 40
stitute an important contribution to the rapidly growing field of research on

thermoelectric devices.

Electron Scattering, The Bureau's program in electron physics is devoted to a study of the free electron and its interactions with various materials. Scattering experiments form a very large part of this research. During the past year, for example, systematic studies of electron scattering for

the Atomic Energy Commission have provided information on both elastic

and inelastic scattering of electrons in solids and vapors. Measurements on

sodium and potassium have revealed the presence of a low-lying loss which

had not been observed in previous measurements. Studies also revealed a change in the characteristic energy low in aluminum as the temperature was

lowered to the liquid helium range. This change was larger than that ex- pected from the change in the lattice spacing. Continued work indicated

that this may be due to strains introduced in the films bombarded. Measurements of the characteristic energy losses in evaporated carbon and natural

graphite have shown that there is a difference in the energy losses for these

two forms of carbon. Work is now in process to determine if the energy

loss in evaporated carbon can be changed by annealing the carbon to the

graphite form.

In another project sponsored by the Office of Naval Research, the elastic

scattering of electrons in metal vapors is being used to study the velocity

distribution in an atomic beam reflected from a surface. The method consists of passing an electron beam at right angles through an atomic beam

and detecting only the electrons which have been scattered by the atomic

beam. To measure velocity distribution, the atomic beam is chopped with

a rotating disk and the electron beam is pulsed. From these two time constants and the rate of arrival of the atomic beam bunches, the velocity can

be determined.

Electron Polarization. Electron beams produced photoelectrical^

from permanently magnetized iron and nickel films were examined for

electron polarization by Mott scattering at 120 kev. A definite upper limit

for the obtainable polarization asymmetry was fixed at around 3 percent

under the present conditions of the experiment. Observations will be re- peated and extended under ultra-high vacuum conditions to complete a search

for the very high polarization predicted in photoemission from magnetic

materials.

Electron Instrumentation. In both electron spectroscopy and mass

spectroscopy, a monochromatic source of electrons is a highly desirable

feature. To attain such a source of electrons, an instrument which is effectively an electron monochromator has been constructed. An electron filter

lens is used to reduce the number of electrons of low energy. To reduce the

high-energy electrons in the electron beam, the beam is modulated with a 40-

cycle signal whose amplitude determines the degree of monochromatization.

An electron diffraction apparatus was constructed for the purpose of obtaining high resolution diffraction patterns. A 10-micron electron beam

can be obtained on the photographic plate at a distance of 70 cm from the

41
final lens. Zinc oxide patterns were obtained which showed diffraction

spots down to 5 microns in size. Kikuchi patterns have been obtained for

single-crystal mica and graphite.

Low-Temperature Electron Bombardment, Studies have been made

of the production of free radicals in condensed nitrogen gas by electron bombardment, sponsored by the Department of Defense. These results have

led to the theoretical interpretation that a weakly bound triatomic molecule of

nitrogen is an emitting species. In addition, an electron diffraction investigation was made of the structure, size, and alinement of crystals in condensed nitrogen as a function of the gas-flow rate and the substrate temperature.

Chemical exchange reactions at very-low temperatures induced by electron

bombardment have also been studied at the request of the Department of Defense. Initial attempts were made to study the reaction between hydrogen

and deuterium molecules, and later a successful measurement of the g-value

was made by bombardment of a solidified mixture of nitrogen-14 and -15.

Physics of Negative Ions, Negative ions play an important part in the

thermodynamics of gases at the high temperatures reached in rockets and

explosions as well as in astrophysical phenomena. To study the structure

of negative ions, the Bureau employs a photodetachment technique. This

special type of photoelectric absorption formed the basis for detailed investigations of the H- ion. The relative photodetachment cross section for this

negative ion was determined from 4000 to 16000 A with a precision of about

2 percent, and results were compared with theoretical calculations. Other

studies include theoretical calculation of the cross section for inelastic collisions with electrons which gave a surprisingly large value, and experiments

Improvements were made in standards of radioactivity (page 44). Left: A

radiation balance is used to measure the rate of energy emission from a radium

source used in preparing the new 10"9 and 10"u

g radium solution standards.

Right: Tank of manganese sulfate used as a moderator in calibrations of the

National Standard Photoneutron Source.

42
on the electron-H- interaction, in which photodetachment signals were

detected.

The detachment spectra of OH- and OD- were also measured as a basis

for a precise determination of the molecular constants of the hydroxyl negative ion. The cross section of these detachments, which initially appeared

very simple, was found to have a complicated structure. Further studies will

he made using a higher optical resolving power.

Calculations of the approximate value of the radiative attachment cross

section of electrons to the 02 molecule were made. The results, combined

with other data, were then applied to a study of ionospheric ionization produced by abnormal increases in cosmic radiation accompanying solar flares.

Atomic Standards of Frequency. Hyperfine and Zeeman resonances

in cesium and rubidium vapors were investigated to determine line width,

pressure and temperature shift, and relaxation mechanisms. As a part of

these studies, carried out in cooperation with the U.S. Naval Research Laboratory, it was found that the frequencies in cesium vapor cells remain

stable to better than 4 parts in 1010 over a period of six months. Hyperfine

line widths in rubidium as narrow as 20 cycles per second (cps) at 6,000

Mc were observed, and buffer gas mixtures were obtained in which the hyperfine frequency is either pressure or temperature independent. Studies of

low-frequency Zeeman transitions, carried out by the Bureau at the Fredericksburg Magnetic Observatory of the U.S. Coast and Geodetic Survey

show that lines as narrow as 3 cps can be obtained with an eicosane-coated

sample and lines as narrow as 8 cps for several buffer gas samples. Two

rubidium vapor atomic clocks are presently under construction (for other

work in this area see 2.15, p. 123).

Scintillation Counting of Neutron Emission Rates. In determining

the neutron-emission rate of "radioactive" neutron sources, the source is

suspended in a manganous sulfate bath, neutrons are captured by the manganese, and the Mn56 activity is normally counted by a Geiger-Muller counter.

A scintillation counter has recently been used instead to provide higher count

rates and allow the accurate calibration of weaker sources than was previously possible. In this way, a more precise value has been obtained for

the ratio of the National reference standard source to the National standard

source. Penetration of Gamma Radiation. Extensive computations were performed this past year on data relevant to the analysis of the shielding properties of structures against fallout radiation. These data formed the basis

for considerable progress toward development of rules and charts for structure shielding engineering. This program is being sponsored by the Office

of Civilian Defense Mobilization, the Atomic Energy Commission, and the

Department of Defense jointly, and the results are already being widely

used in these agencies in making shielding estimates of various kinds.

One study of gamma-ray penetration for the Civil Effects Test Group of

the Atomic Energy Commission included postdetonation measurements at

531788 O—60 4 43
the Nevada Proving Grounds. This on-the-scene experimental data on the

effects of fallout was one of the first attempts to make fields measurements

in arrangements which lend themselves to a theoretical approach. By

allowing an adequate comparison between experimental data and theoretical

calculations, this work provides a basis for extending theory to configurations

more elaborate than those for which predictions are now possible. Results

of this investigation should thus be very useful in the development of suitable shelters against radiation from nuclear weapons.

Radioactivity Standards, The standardization of radioactivity measurements throughout the country depends primarily upon the distribution of

samples with certified activities and the performing of tests and calibrations.

During the past year, 715 samples were issued, 40 radium assays were made,

and 400 radon tests were carried out. The Bureau also added a new series

of 10~9

- and 10_11

-g radium standards for distribution to replace a lessaccurate earlier series. A measurement of these standards at the Physikalisch-Technische Bundesanstalt gave a value which agreed within 0.3

percent with the Bureau's certified value. Other international intercomparisons were carried out with 10 countries in North and South America,

Europe, and South Africa.

A recalibration of the Bureau's carbon-14 standards formed the basis for

a new determination of the half-life of carbon-14. A half-life value was also

obtained for radium-226 from a measurement of rate-of-energy emission.

X-ray Studies, Studies, supported by the Atomic Energy Commission,

are being carried out to obtain experimental data which can be used to describe X-radiation under any set of experimental conditions and to check

theoretical predictions. As a part of this work, the linear polarization of

X-rays produced with 0.5 and 1.0 Mev electron were experimentally determined at different emission angles and for different regions of the X-ray

spectrum. Results verify interesting reversal characteristics of the polarization and point up certain differences with theoretical predictions. Detailed

studies of the X-ray production process are also underway to obtain information on the angular distribution of recoil electrons as well as on the polarization effects that occur in the process.

Linear Electron Accelerator, In recent years the number of industrial

installations utilizing intense high-energy electron beams for the processing

of materials have increased greatly. In order to insure the economical and

efficient use of this new tool, the interactions of high-energy electrons and

X-rays with matter must be understood. Among the important processes are

photonuclear interactions, absorbed dose measurements, radiation energy

measurements, and radiation characteristics.

To extend the Bureau's capabilities in this area of basic research, a linear

electron accelerator has been designed that will produce electron beams with

energies of 40 Mev and power output of 40 kilowatts. This electron beam

power is 100,000 times more than that obtainable with the radiations source

presently in use at the Bureau.

44
High-Energy Radiation. In the research program conducted with the

Bureau's 50-Mev betatron and 150-Mev synchrotron significant progress

was made toward a better understanding of the basic interactions of highenergy electrons and X-rays with matter. Of interest to users of betatrons

and synchrotrons was a new evaluation of the bremsstrahlung cross section at

the high-frequency limit. This evaluation, based on theoretical estimates and

experimental measurements, indicated the presence of a finite number of

photons at the high energy tip of the bremsstrahlung spectrum.

In work supported by the Atomic Energy Commission an improved calibration was made of the Bureau's bremsstrahlung monitor. A calorimetric

means was employed in this recalibration and it is felt that the uncertainty in

the calibration between 10 and 170 Mev is less than 2 percent. In other work

supported by the AEC a detailed study was made of the shape of the photoneutron yield curve for the nuclei around the doubly magic nucleus Pb208

. The nuclei studied were Pb206

, Pb207, Pb208

, and Pb209

. It was found that the

neutron production cross sections for these nuclei did not have the simple

Lorentz shape expected on the hydrodynamic model for closed shell nuclei.

The deviations observed are probably an indication of the extremely low-level

densities of these nuclei.

A detailed study was also made of dosimetry measurement systems, and

results were presented at the 1958 International Conference on the Peaceful

Uses of Atomic Energy.

Gamma- and X-ray Calibrations. Instruments used as laboratory

standards for gamma-ray measurements in industry, science, and medical re- search are calibrated against the Bureau's cavity ionization chamber. To

improve the accuracy of these calibrations, an intercomparison was made

between the results of this usual method and those obtained with a free-air

chamber. The free-air chamber while more difficult to use gave results that

agreed within 1 percent with those from the cavity ionization chamber for

cobalt-60 and cesium- 137 gamma rays. In addition, a basis was provided

for refining the corrections applied to calibrations, resulting in a considerable improvement in overall accuracy.

The need for improved low-energy X-ray standards has been increasing

with the extensive use of low-voltage medical X-ray equipment and the need

for measurement of low-energy stray X-rays from equipment employing

electron tubes. Accordingly, investigations were carried out to obtain the

design characteristics of a free-air parallel-plate ionization chamber suitable

for X-rays produced in the range 20 to 100 kv. A chamber was constructed,

tested, and intercompared with the present free-air standard chamber over

the appropriate voltage range. The comparison indicated satisfactory agreement and the new free-air standard together with the older 250-kv standard

permits X-ray calibrations over the range 20 kv.

Dosimetry. The oxidation of ferrous to ferric ions in a ferrous sulfate

solution is a widely used technique for dosimetry of X- and gamma rays.

The Bureau has investigated "chemical dosimetry" with special reference to

the effect of factors such as purity and age on the ferric ion yield.

45
An investigation of the behavior of silicon cells exposed to high doses of

cobalt-60 gamma rays showed that the photovoltage and photocurrent

decay with time, probably because of radiation damage. The concurrently

decreasing electrical resistance of the cell could, after the irradiation, be

restored stepwise to its original value, by annealing with increasing temperatures up to 250° C. The measurements will be continued under different

experimental conditions.

Photographic films have been used extensively for the measurement of

radiation, although they do not have all of the desired characteristics for

such measurements. Experience with this type of dosimetry indicates the

importance of a thorough understanding of the fundamental processes involved for the proper interpretation of results. Accordingly, studies were

continued of several effects. It was established that the developability of the

latent image on the ascending branch of the characteristic curve increased

with exposure rate. Attempts are now being made to locate a region where

developability decreases with increasing exposure rate.

Methods for measuring very high gamma-ray doses are of interest in connection with food sterilization and radiation damage effects to materials. A

new method was evolved, by which ordinary commercial dosimeter film can

be used for gamma-ray measurements in the range from about 2 X 104 to

5 X 107 r, with a precision of about 5 percent. This method utilizes the latent

image without development and employs narrow bands of red light for

determining the opacity of the exposed film.

2.5. Chemistry

Basic and applied research in many fields of chemistry is being conducted

by the Bureau. Fundamental studies include such activities as developing

and improving methods for the measurement of the chemical properties,

composition, and behavior of substances; preparing standard substances of

known composition or properties; making accurate measurements and collecting data on chemical systems; studying the properties of molecules and

atoms in their relation to chemical reactions, and providing technical and

advisory services.

The special investigations pursued during the past year in inorganic,

analytical, organic, and physical chemistry included studies of new methods

for chemical analysis by emission and absorption spectroscopy as well as by conventional chemical means. Substances of high purity were prepared

and methods of analyses developed, and radioactively labeled sugars were

synthesized. Different types of standard samples were produced and certified, chemical constants of thermochemical data determined and tabulated,

and the mechanisms of organic reactions and photochemical processes

investigated.

Analysis of Tritium-Labeled Compounds, Tritium is the radioactive istotope of hydrogen, a constituent of nearly all organic compounds,

and can enter into the same chemical reactions as hydrogen. In the form of

tritiated water or other tritiated reagents, tritium can react with a wide vari46
General-purpose manifold for handling tritium in a closed system was developed to facilitate the synthesis of tritium-labelled carbohydrates. The radiation emitted by the tritium makes it possible for scientists to determine the

amount and location of the carbohydrate in any stage of a chemical reaction,

and in this way to study the role played by individual molecules in the process

(page 46).

ety of organic compounds. A few tritiated starting materials enable the

chemist to prepare numerous radioactive compounds. Once incorporated in a stable molecule as a substitute for hydrogen, the isotope serves as a "tag"

that can be used to trace the course of an atom or a molecule through an

entire series of complex processes. Despite these promising features, tritium

has not yet received the attention that its properties, as a research tool, warrant, because of a lack of convenient methods for its analysis. If a radioisotope is to have maximum usefulness in chemical and biological studies, it must be possible to measure its radioactivity rapidly and simply.

As the first step in a program, sponsored by the Atomic Energy Commission, to synthesize tritiated sugars and sugar derivatives, a convenient analytical method was developed for determining tritium in water-soluble, nonvolatile materials. This simple method requires no special training of personnel and no elaborate equipment. In essence, it consists of combining

the radioactive substance with a solution of a thickening agent, carboxymethyl-cellulose. This mixture is then converted to a film, on a counting

plate, and its radioactivity is assayed with a windowless, gas-flow, proportional counter. The amount of tritium present is calculated from the net

47
count, the weight of the film, and an empirical constant (determined with a

substance of known activity) . By this procedure, one-billionth of 1 milligram of tritium can be readly determined.

The synthesis and distribution of carbohydrates position-labeled with

radioactive tritium is now well underway. The availability of these substances together with the new method of tritium analysis is expected to

stimulate the application of tritium in biological and chemical research.

Acid Strengths in Benzene. With the increasing use of monaqueous

solvents in chemistry, it has become ever more important to understand how

the behavior of acids and bases is affected by the nature of the solvent employed. Two solvents which represent almost the extremes in their effects

on dissolved acids and bases are water and benzene. The comparative inertness of benzene makes it one of the best solvents to use in studying the

nature of interactions between dissolved acids and bases, including various

manifestations of hydrogen bonding. Acids are present in benzene almost

exclusively in the molecular state, because benzene is only feebly basic and

has a low dielectric constant. In contrast, interactions of hydrogen bonding are masked in water because this solvent itself is associated in various

ways with the solutes. The presence of acids in water solution is indicated

by the ions which are formed as a result of two properties of water—its ability

to function as a base and its high-dielectric constant.

The Bureau has developed a spectrophotometric procedure for measuring

relative strengths of carboxylic acids in benzene, using diphenylguanidine as the reference base, together with an indicator acid. This procedure was

applied to benzoic acid and 39 substituted benzoic acids, and the results were

correlated with existing data for the relative strengths of the same acids in

water and alcohols. Valuable insight was gained into the role of water in

modifying the strengths of certain acids. The data on acidities in benzene

have been found useful elsewhere in the evaluation of resonance effects on

reactivities of benzene derivatives and in correlating ultraviolet absorption

spectra with molecular behavior.

Determination of Phosphate, Silicate, and Arsenate. The separation and determination of small amounts of phosphate, silicate, and arsenate

when they occur together in solution has long been a difficult problem. However, a rapid, accurate method has now been developed for quantitatively

separating and determining these ions. On the addition of ammonium

molybdate, the three ions form heteropoly molybdate complexes, which can

be extracted selectively at high acid concentrations. First the phosphate

complex is extracted with ethyl ether, then the silicate complex with butanol,

and finally the arsenate complex with methyl isobutyl ketone. Each of these

complexes, when reduced with stannous chloride, produces a blue solution.

The optical density of the solution, measured with a spectrophotometer, is

referred to a calibration curve to determine the amount of the element present

in the original sample. The method should be useful in controlling the

quality of such materials as chemicals, metals, glasses, and water which contain these salts as impurities.

48
Separating Metallic Elements in High-Temperature Alloys. The

metaJJic elements tungsten, molybdenum, niobium, tantalum, titanium, and

zirconium are becoming increasingly important in the nuclear reactor, missile, and high-speed aircraft fields. Moderate amounts of these elements are

added to metallurgical alloys to improve specific physical properties—particularly heat resistance. Because of the complex composition of these hightemperature materials, spectrographic and X-ray methods are used to control

their quality in production.

Chemical procedure - are being established for the analysis of standards

used in calibrating th~se spectroscopic and X-ray instruments. By incorporating ion-exchange columns, two detailed procedures were developed for

the separation and determination of niobium and tantalum in titanium-base

alloys and of titanium, zirconium, niobium, and tantalum in complex alloys.

Until recently it had not been possible to separate these metals in alloys

quantitatively because these transistor elements belong to the same or adjoining groups of the periodic table and thus behave similarly. However, this

difficulty was overcome by a three-step procedure based on the formation of

metal-fluoride complexes which have different properties.

Air Pollution. Air pollution presents a problem of great importance.

Foreign substances discharged into the atmosphere from a variety of

sources affect health and comfort, plant and animal life, and the use and

durability of many products. The analysis of the atmosphere and the determination of the origin of the contaminants is particularly difficult because of

their very low concentrations and the wide variety of reactions between them.

Fundamental studies of the photochemical processes related to air pollution are being conducted under the joint sponsorship of the Department of

Health, Education, and Welfare, and the Bureau. These studies are part of

a larger program directed toward obtaining fundamental knowledge of elementary chemical reactions and the mechanisms of energy transfer. Processes involving very reactive species such as free radicals and excited molecules are of particular interest. For this reason, the primary dissociative

processes were extensively investigated for several compounds thought to

dissociate exclusively by molecular rearrangement. However, results have

shown that free radicals are formed in the primary processes.

Molten Salt Studies. Since electrolysis of molten salts is a promising

method for depositing coatings of such refractory metals as titanium, molybdenum, or tungsten, the Bureau is studying the electrochemical properties of

molten salts for the Atomic Energy Commission. During this investigation a reference electrode consisting of a porcelain envelope and a silver-silver

chloride internal element, was developed. However, its applicability is

somewhat limited by inadequate knowledge of liquid junction potentials in

fused salts. The same porcelain that is used as an envelope for a molten

salt reference electrode may serve as a sodium ion conductor. This envelope

completely protects the silver electrode from contamination by the molten

salt and is unique in its low-electrical resistance to the passage of sodium

ions. The electrode can be used at temperatures up to the melting point of

49
Left: Samples of benzene with controlled amounts of impurity are packaged

in a vacuum system. The vacuum transfer system assured the identity of the

42 samples distributed for an international comparison analysis. Right:

Analyzing alloys containing minute amounts of titanium, zirconium, niobium,

and tantalum. A relatively simple method based on the formation of metalfluoride complexes was developed for this analysis (pages 51, 49).

silver and is currently being employed to measure the transference numbers

of ions in molten sodium salts. In addition to the value of the transference

numbers in interpreting liquid junction potentials, these data are also important in forming theories of structure, electrical conduction, mutual solubility, and other properties of fused salts.

Abrasive Jet. The degree of abrasion resistance of organic and inorganic coatings is an important consideration in the design and preparation of protective coatings. Because this property was difficult to measure

accurately, the Bureau developed the abrasive jet method a few years ago.

With this procedure, abrasion resistance is measured in terms of the time

required for a small jet of fine abrasive particles to wear away the coating

on the underlying material (substrate). Conditions of distance angle, pressure, and abrasive flow are closely controlled.

The ease and reliability of the measurement has recently been improved.

For example, abrasion tests were conducted on a series of prefinished hardboard materials used for wall paneling. In these tests, the jet abrader

accomplished in 30 minutes, with superior performance, a task which re- quired many hours of testing by the widely used ASTM falling sand method.

The abrasive jet method is inherently free from errors caused by such

50
factors as reuse of abrasive, heating of substrate, clogging of abrading

wheels, and uncertainty of end point. Its basic simplicity, speed, and re- producibility, as well as its use with a reference material, promises better

interlaboratory agreement than was possible before in measuring abrasion

resistance.

Thickness Gage. As new guns are developed with higher rates of fire

and muzzle velocity, satisfactory performance and life for the bore of the

barrel depend more heavily on a suitable coating to protect the steel from

high-temperature effects, mechanical wear, and erosion by powder gases.

Chromium plate of the proper thickness and with the proper physical characteristics is one of the best materials for providing the necessary bore

protection.

Because the thickness is an important factor in the quality of these gun

barrels, the Bureau, in a program sponsored jointly by the Army and Navy,

has modified and adapted the "Dermitron" gage for measuring the thick- ness of chromium plate in gun bores. The device is capable of measuring

thickness up to 0.02 in. in caliber .30 bores (0.30 in. diam.), with tube

lengths up to several feet. Electroplated coatings of chromium and other

metals are extensively applied to the internal surface of tubes for use in various process industries. The gage can be readily adapted to the measurement of coating thickness in such tubes.

International Comparison of Techniques for Determining Purity.

Impurities in almost all chemical substances cause depression of the freezing

point. Measurement of this depression provides one of the most widely

accepted methods of determining the absolute purity of chemical substances.

Since workers in different laboratories and different countries have obtained

varied results, the best conditions for the determination and the use of data

are not universally known.

At the request of the International Union of Pure and Applied Chemistry,

the Bureau has organized a cooperative program on purity control. This

program features a comparison of analyses by the most experienced international laboratories. The Bureau has issued to these laboratories four

cryoscopic samples of benzene, namely, one sample in highly pure form and

three contaminated with regulated amounts of known impurities. The pure

benzene was refined to a higher purity than has previously been achieved

on such a large scale—99.999 mole percent. The compositions of these

solutions are known only to an otherwise nonparticipating group.

In addition to contributing the samples and participating as one of the

research laboratories in the measurement of purity (using calorimetric and

thermometric cryoscopic procedures), the Bureau is compiling the data

from all the groups. Results from this broad program should provide information on the agreement that can be reached by different laboratories

using various cryoscopic techniques to assay the purity of similar systems.

Purification of a Special Lot of Mercury. Although mercury is

neither abundantly nor widely distributed in nature, it has played an important role in alchemy, medicine, and modern science through the ages. One

51
of mercury's important physical properties is its density, which has not been

accurately determined. To aid in the determination of this physical property the Bureau subjected 1,000 lb of the virgin metal to careful refining,

including acid washing to remove all base metals. The entire purified

product was double distilled and then mixed to a uniform substance in a

single container. About 40 lb was sent to the National Physical Laboratory

at Teddington, England, for a determination of its density. The rest will

be used for special scientific research requiring very pure mercury with an

accurately determined density.

Apparatus used in studying the photochemical decomposition of organic and

inorganic compounds which play important roles in air pollution (page 49).

52
Reagent Chemicals. Participation in the preparation of specifications

and test methods for reagents represents an important area of the Bureau's

cooperative activities. By the continual testing of the reagent chemicals

which it buys, the Bureau has long assured its laboratories of high-quality

analytical reagents—thus maintaining uniform chemical tools for research.

Within the area of reagents, it is also active in a committee, established by the

American Chemical Society, to investigate the purity of reagent chemicals

and to prepare specifications for these materials. This committee is composed of representatives from government, industry, and reagent manufacturers.

A revised edition of new and improved specifications adopted by this group

will be published in 1960. Translation of previous specifications by a

chemist in Spain has made them available to the Latin countries.

Calibrated Glass Spheres* Requirements of practically every commercial powdered or granular material—from cosmetic face powder to solid

adsorbents used in sugar refining—include maximum and/or minimum

limits of the particle sizes. In particular, knowledge of particle-size distribution is often required both for quality control and research purposes.

Such widely diverse industries as foundries, petroleum laboratories, sugar

refineries, soap manufacturers, cement makers and users, roof-material companies and chemical firms use sieves both for checking particle size and for

measuring particle-size distribution.

In the past, discrepancies were often found when sieve analyses from different laboratories were compared. One cause of this problem has been

traced to the method of calibrating testing sieves, which involves the optical

measurement of a small number of openings from which the average sieve

opening is computed. If the meshes of the sieve are distorted, causing a wide variety in the shape and size of the openings, particles which are slightly

larger than the average opening may find an oversized hole and pass through

the sieve. Thus the effective opening will be slightly larger than the average

opening.

To eliminate this difficulty, an improved method of calibrating testing

sieves—based on the effective opening—was developed. This technique

involves using a set of calibrated glass spheres of known particle-size distribution and measuring the diameter of the spheres that will just pass through

the sieves. A limited number of calibrated samples were used successfully

by various industries in the past eight years. Because of the increasing

demand for the samples, two new lots were recently prepared for distribution as NBS standard samples. With these standards, closer tolerances may

be achieved in the testing of commercial sieves and more reproducible results

obtained in sieve analysis.

Uranium Isotopic Standards. In cooperation with the Atomic Energy

Commission, a series of 15 isotopic standards of uranium oxide has been

prepared for evaluating reactor fuels and for applying in related branches

of nuclear chemistry. These standards are available to both domestic and

foreign laboratories through the usual AEC licensing arrangements. An

53
The standard sample for

sieve calibration is a set

of calibrated glass

spheres of known particle-size distribution (inset). In use, the sample

is placed in a graduated

nest of sieves and is then

agitated. The beads

remaining in each sieve are indicative of the size

of its openings. This

method has proved su- perior to the optical observations formerly used

in sieve calibration (page

53).

NBS standard sample of highly purified normal uranium oxide (U3 08 ) is

also being distributed for the chemical standardization of uranium analyses.

Spectrometric Analysis by X-rays, The determination of composition by X-ray spectra has the advantages of providing improved precision for

major constituents and being nondestructive to the samples. The X-ray

method can be applied to the analysis of samples in various forms, including

solid sections of metals, compressed pellets of powdered materials, and even

liquid samples or solutions with the aid of a spectral cell.

Recent improvements in equipment for the analysis of materials by X-ray

spectra enable this tool to be employed with greater speed and efficiency. A

multichannel X-ray unit has been installed which provides simultaneous

measurement of the concentrations of 10 chemical elements. These may be

selected from a group of 15 elements each on a fixed wavelength channel.

In addition, a scanning unit permits the selection and measurement of an

element not included in the fixed array. This unit has been calibrated for

the analysis of iron and iron alloys over a wide range of compositions, cover- ing low-alloy steels, stainless steels, and tool steels. It will be employed

largely to measure the uniformity of metals and alloys used for calibrating

optical and X-ray spectrometers in other laboratories. These instruments

are designed for controlling composition by the iron and steel industry and

for analyzing the finished products by both the producer and the consumer.

Nuclear Magnetic Resonance Studies. The techniques of magnetic

resonance spectroscopy provide the chemist with an exceedingly valuable

tool for investigating molecular structure, chemical equilibria, analytical

problems, and kinetic processes. The superior resolution achieved in the

spectral range of nuclear-resonance absorption has enabled the study of fine

54
details in molecular structure and interactions entirely inaccessible by other

methods. These applications are possible because of the extreme sensitivity

of nuclear magnetic resonance to the nature of the molecular environment.

During the year the Bureau initiated a new project on the measurement of

nuclear spectra of selected chemical compounds under conditions of high

resolution. The basic apparatus consists of a high-resolution electromagnet

(having a nominal field of 14,000 gauss) and three radiofrequency transmitter-receivers operating at three frequencies. Initial studies emphasize the

structural chemistry of compounds containing phosphorus, fluorine, and

carbon, and molecular processes involving proton exchange.

2.6. Mechanics

Precise mechanical measurements are critically needed in research, development, and production of many items. The accuracy required of these

measurements has increased to the point where more adequate transfer instruments and improved calibration standards are needed, particularly in

such areas as propulsion, guidance systems, and airframes for aircraft,

missiles, and space probes.

In its mechanics program, the Bureau develops and maintains standards of

force, pressure, mass, shock and vibration, sound intensity, and the rate of

gas and liquid flow. It also develops measurement techniques and transfer

standards so that these standards can be disseminated to science and industry.

Bureau work also includes determining the density of solids and liquids; the

velocity of sound in gases, liquids, and solids; the constant of gravitational

force; and the properties of materials and structures.

These standards are in growing need over ranges that are extending

upward and downward. Pressure measurement, for example, is now needed

in the range of 100,000 atmospheres, where industrial processes now operate.

On the other hand, high-altitude and high-vacuum studies have increased

the need for extremely low-pressure measurement. Requirements for force

measurements have increased with the rapid development of propulsion

systems having thrusts exceeding 1,000,000 lb.

During the past year, progress was made in standards of high-pressure

and humidity; measurements of dynamic pressure; high-temperature strain

gages; and in the design of dead weight machines for the calibration of forcemeasuring devices. Yet, still more effort will be needed in these and other

areas of mechanical measurement if the needs of science and technology are

to be met adequately.

Expanded Pressure-Calibration Service, Attention was given to the

urgent problem of providing calibration services over a much larger range

of pressures than now covered (presently 5 to 60,000 psi) . Plans are being

made to establish additional fixed points at pressures to several hundred

thousand pounds per square inch, and equipment was built for gathering

information on the behavior of materials at pressures up to 1,500,000 psi.

In calibrating instruments for measuring high-transient pressures, a unique

55
device was constructed to generate pressure in steps of accurately known

amplitudes up to 50,000 psi.

Because of the increasing requirements for accurate measurements of low

pressures, plans were made for substantial work toward improving methods

for measuring pressures in the vacuum range.

Vibration Pickup Calibration Service, Vibration measurements are

needed in developing space vehicles, missiles, aircraft, ships, and machines.

There is a continuing demand for improving the accuracy of these measurements, which are based on vibration standards.

As part of a program of developing vibration standards, an electrodynamic

standard was modified so that it is free of transverse motion throughout

almost all of its frequency range. The standard produces rectilinear motion

by a suspension of its moving parts from a frame by tensioned wires. The

standard (an electrodynamic vibration exciter equipped with a velocitysensing coil) is calibrated by the reciprocity method. In the vibration

pickup calibration service recently established at the Bureau, the standard is

used at frequencies from 10 to 2,000 cps at accelerations up to 10 g. The

errors of the motion applied to the pickups do not exceed 1 percent up to

900 cps and 2 percent between 900 and 2,000 cps.

Stroboscopic Vibration Analyzer Devised, Stroboscopic instruments

have been used for many years to visualize and analyze periodic motion.

Applying such instruments to large, complex structures is limited because it

is not possible to observe all parts of a structure at the same time. At

higher frequencies, amplitudes of motion are too small to be seen. These

Vibration pickup mounted on the newly modified vibration standard (left).

At each of the 3 rectangular blocks, helical coil springs are attached to wires

to minimize transverse motion during vibration (page 56).

56
difficulties were resolved by an instrument for studying amplitude and phase

relations in complex periodic phenomena, principally vibration of complicated bodies. The motion at each point of interest is detected by a vibration

pickup. The signal from each pickup is heterodyned with a common signal

that differs from the vibration frequency by a small amount to produce a

set of signals at the difference frequency. The desired relations are

exhibited at the difference frequency that is low enough to give a slow motion effect. The output circuits allow a choice of presentation suited to a particular problem.

Vibration Dampers Evaluated, In a program for the Rural Electrification Administration, Bureau scientists recently performed field vibration

tests on telephone wires installed near Tyler, Minn. These tests were made

to evaluate various dampers installed on telephone wires used over extra long

spans. Plastic sleeve dampers had been found effective on spans up to

several hundred feet long. These dampers were found ineffective, however, where there are many spans between 800 and 1,900 feet, and where

prevailing winds are from 10 to 30 mph. Under these severe vibration

conditions, there were frequent fatigue failures of the wire at connectors

and splices. Although field tests indicated that most types were ineffective,

two types were satisfactory, including one of Bureau design. The Bureau's

damper consists of a hollow tube filled with sponge rubber under slight compression, providing a continuous resisting force to all high-frequency

vibrations.

New Acoustical Theory Proposed. Sound reception by the ear was

described mechanistically in a new theory that is useful for calculating, in a simple way, the quantitative limits of the ear's operation as part of a communication system. The theory was derived from consideration of efficiency

limits of instruments used in measuring rapidly fluctuating sounds. Results

of experiments dealing with just noticeable differences in frequency and

energy of sounds, detectable by the human ear, were used to compute two

constants needed in the theory. These constants are useful in describing

several aspects of ear behavior.

Uniform Magnetic Field Equipment Built. A standard is needed for

measuring the susceptibility of hearing aids to annoying hum that is generated by alternating fields such as those surrounding fluorescent lights,

motors, and other equipment. In developing methods for the Veterans'

Administration to test hearing aids for hum pickup, equipment was built

to produce a nearly uniform magnetic field. The equipment consists of

three mutually perpendicular coils; each coil can produce a nearly uniform

field over a cross-sectional area approximating the maximum area of a typical hearing aid. A feedback system was also developed to cancel the

ambient stray fields without affecting the test field.

Improved Hygrometers Developed. To provide a basic reference for

humidity measurements, a gravimetric hygrometer was built to permit direct

weighing of the water contained in a known gas volume. This instrument

should make it possible to attain needed improvement in the accuracy of

57
0 90 180 270

A stroboscopic vibration analyzer was developed for determining amplitude

and phase relations of vibrations of any frequency. This device is expected

to be useful in determining vibration characteristics of aircraft and missile

structures. Inset represents vibration patterns (page 56).

humidity measurements, particularly at temperatures below the freezing

point, as involved in atmospheric studies.

Further attention was given to improving humidity-measuring elements for

use in radiosondes, and a very promising improvement (a thin barium

fluoride film element) was developed under the sponsorship of the Navy

Bureau of Aeronautics.

Fuel Flowrate Calibration Facilities. For optimum flight performance, aircraft engines and their fuel metering components require precise

adjustment and test prior to installation. Such tests require the measurement of fuel flowrates to a precision of 0.5 percent or better. Under sponsorship of the Navy Bureau of Aeronautics, the Bureau maintains reference

flowrate calibration facilities for use with liquid hydrocarbon fuels. These

facilities are used to calibrate transfer reference flowmeters whereby the

accuracy of calibrators at other locations can be compared. Manufacturers

of flowmeters, aircraft engine accessories, aircraft engines, and airplanes, as well as the military services are all participating in this program of flowrate

standardization. Throughout the aircraft industry, there have been closer

correlations between tests of identical components at different locations,

thereby improving the flight performance of engines.

This program also includes evaluating flowmeters for use in aircraft test

58
work. Evaluation tests reveal the limitations of existing flowmeters, show

the modifications required for better performance, and encourage the development of new instrumentation for precisely measuring flowrates.

Inertial Forces in Unsteady Flow Studied. When a fluid is accelerated past a submerged object, the total force exerted by the motion on the

body can be considered to consist of a drag force (caused primarily by flow

separation) and an inertial force that accompanies the acceleration of the

fluid. A study of this problem was sponsored by the Office of Naval Research, primarily to obtain instantaneous force coefficients for bodies such

as cylinders and flat plates for the general case of unsteady flow of water.

Of particular interest to hydraulic engineers is the force of waves on components of coastal structures. In problems of this nature, models are often

studied. The need to know the scale effect on each force component is one

example of the need for a basic understanding of the problem. The force

components depend upon the entire flow around the object, including the

wake and motions aft of the body. For this reason, research is now directed

toward the relation between the instantaneous force, as flow velocity changes,

and the instantaneous shape and motion of the wake.

Internal Progressive Waves Investigated. Just as waves form on a water surface, so wave motions may also occur between denser and lighter

layers of water when, for example, these layers are formed by solar heating.

Wave motions in such layers are less well understood than ordinary surface

waves, and their behavior depends on the amount and sharpness of the

density difference. An investigation, sponsored by the Office of Naval

Research, is being conducted to determine the formation and characteristics

of such waves.

Stratified conditions were simulated in the laboratory by placing a layer

of fresh water on a layer of salt water in a long rectangular channel. Waves

nearly as high as the layer of smaller thickness can be produced with scarcely

a perceptible disturbance at the water surface. Such waves travel much

slower than surface waves. Their height, velocity, and decay with distance

as a function of the density variations are the chief characteristics being

investigated.

Instability of Laminar Flow Examined. Because laminar flow is

unstable in a boundary layer (a thin layer near a wall), turbulent motions

ensue and flow characteristics are completely altered. How turbulent motions begin from an instability is a subject that has been under intensive

investigation for some time. The National Aeronautics and Space Administration is continuing sponsorship of this investigation at the Bureau. Present

theories accurately describe the better known unstable wave motions that

lead to secondary motions in the form of streamwise vortices. These

motions bridge the gap between wave and turbulence, thus they are a vital

link in the onset of turbulent motion. They are not yet, however, embodied

in existing theories. A true physical picture is emerging from this work,

and the information is enabling the theorist to formulate a realistic theory of

the origin of turbulence.

531788 O—60 5 59
Dynamic Properties of Materials Measured. There is a lack of

reliable and comprehensive data on the effects of dynamic loading on

the physical properties of structural materials. Thus, engineers have been

handicapped in designing structures to resist loads that are applied rapidly.

For some important structural materials, it has been shown that the values

of physical constants determined under static loading are significantly different from values determined under rapid loading.

To meet these needs, the Bureau has been investigating new devices and

techniques for measuring large transient strains in long bars. The dynamic

mechanical properties of specific structural materials were also measured.

Further insight is provided on the theory of stress wave propagation in

solids by investigating stress wave pickups operating on resistance, capacitance, and inductance principles. These results are being used in attempts

to obtain reliable stress-strain relations for structural materials.

Strain Gage Evaluation Facility. To assure safe design and efficient

use of structural materials in modern applications, it is essential to have a knowledge of the properties of materials and structural configurations at

elevated temperatures. To determine these properties accurately, it is neces- sary to measure the strains and deformations in materials under load at

elevated temperatures.

A number of gages have been produced to meet the increasing demand

for high-temperature strain-measuring equipment. Experience with these

early gages indicated that the problems associated with their use were more

complex than had been generally anticipated and that the test results obtained with them were often of doubtful validity. It was soon apparent that

a comprehensive evaluation of these gages was required, and the Departments of the Navy and Air Force undertook the sponsorship of an evaluation facility at the Bureau.

The Bureau has developed facilities for determining some of the important

characteristics of these gages. The factors measured include gage factor

and its variation with temperature; change of resistance with time at constant

temperature; change of resistance with temperature; behavior when heated

rapidly; performance when subjected to high strain levels; and, the effects

of storage at various humidity levels. A number of gage types have been

evaluated. The development of improved evaluation techniques and facilities as well as the evaluation of available gage types is continuing (for other

Bureau strain-gage work, see p. 84)

.

Thermocouple Reference Being Determined. There is need for a temperature-sensing device that will withstand temperatures of 3,500° F and

above. The iridium versus iridium-rhodium thermocouple has gained in

popularity with researchers and developers, in the jet-engine industry, and

to some extent in the rocket and reactor fields. A serious drawback to the

use of this thermocouple is the lack of a reference table, similar to those

now used for conventional thermocouples.

In previous work with this thermocouple, errors came from three sources:

60
An engineer with the Department of Weights and Measures, National Laboratory of Metrology, Mexico, is instructed in the operation of a large precision

balance used for weights up to 25 kg. During the year, approximately 900

foreign scientists and technicians, representing 50 countries, visited the Bureau

(page 13).

Black smoke came from oxidation of the thermocouple and blackbody, excess

heat was conducted from the blackbody, and stray fields were introduced by

the high-frequency generator used to heat the blackbody. To minimize

these errors, changes were made to the equipment. Smoke was eliminated,

and heat conduction and stray fields were nearly eliminated. Preliminary

tables were determined (to 3,800° F) for 2 thermocouples of iridium versus

iridium plus 60 percent rhodium. Other thermocouple work is described on

page 291.

Jet-Engine Thermocouples Tested. A continuing program directed

toward improving equipment for measuring temperatures in jet engines, is

sponsored by the Wright Air Development Center. This work is concerned

with maintaining accuracy and dependability of sensing and measuring elements as conditions in the engines become more severe. A new type thermocouple, designed to measure preturbine temperatures

up to 2,300° F, was developed by an industrial contractor for the sponsor.

61
The Bureau began determining a reference table for this thermocouple, and

tentative values were obtained. A thermocouple indicator was examined for

use in air varying from tropical to arctic temperatures. Because of changes

made as a result of this examination, the instrument is practically unaffected

by changes in ambient temperature.

Several cooperative projects were begun between industrial laboratories

and the Bureau at the request of the Committee on Physical Measurement

Sensing of the Society of Automotive Engineers. Changes in two groups of

engine-type thermocouples were determined after exposure to jet engine ex- haust gases for 1,000 hours at 1,250° and 1,750° F. The thermocouples

were not mechanically affected at the lower temperature, but in most cases they were destroyed at the higher temperature. At the higher temperature,

most thermocouples were oxidized; the ones which were not destroyed by

oxidation continued to function. In neither case, however, was the signal

To learn more about jet engine combustion, the shock waves of high-speed

missiles were used to study combustion in supersonic streams. Here unsteady

combustion is displayed behind the shock wave of a sphere propelled at Mach

5 through a mixture of hydrogen and air (page 63).

62
from the functioning thermocouple affected seriously. Observations have

been made which show that the response time of a thermocouple changes

with temperatures, and these data are being analyzed.

Jet'Engine Combustion Explored. Combustion in standing detonation waves and in supersonic streams appears to be of great practical importance in the field of propulsion of hypersonic missiles and planes, but only

limited information is available on the requirements for combustion under

such conditions. One method of research is to use the shock wave in front

of high-speed missiles to investigate conditions such as pressure, temperature,

and shock strength needed for combustion in a standing detonation wave.

This method can also be used to study the use of a solid object to stabilize

the detonation wave in space. Spheres of up to 20-mm diameter were propelled to Mach 10 in equipment that was assembled to make optical studies

of gas near these spheres. Exploratory experiments (up to Mach 6 in

stoichiometric mixtures of air and hydrogen at low pressure) indicated that

combusion is initiated by the shock, but that it occurs behind the sphere and

its shock wave.

Another jet-engine problem is the high-altitude effect that leads to low combustion efficiency and capacity of the combustion chambers. It was found

that small quantities of oxygen in the primary zone of a combustor increase

both the efficiency and capacity of combustion at a given altitude, or enable

an engine to maintain performance at higher altitudes.

2.7. Organic and Fibrous Materials

The Bureau's research in organic and fibrous materials spans the broad

field of natural and synthetic polymeric materials. To gain a better understanding of the association of constitution, structure, and properties of

polymers, studies are being conducted on rubbers, textiles, papers, leathers,

plastics, dental resins, and related materials. The properties of polymers

depend upon the size, shape, distribution, and flexibility of their molecules,

and interactions with other molecules. Basic knowledge of the polymers and

improved methods for measuring their fundamental properties are necessary

for the development and efficient utilization of these materials.

Basic research during the year covered reaction mechanisms involved in

the degradation of synthetic resins and collagen exposed to high temperatures

and to nuclear radiation, crystallization phenomena in polymers, polymerpolymer, and polymer-solvent interactions in polymer solutions, and glass

transitions in rubber-sulfur systems. New methods were developed for

determining water penetration in untreated and polymer-impregnated leathers, surface tension of high viscosity liquids, fluorescence of dental materials,

and for the interlaboratory comparison of testing procedures. Investigations on the properties of materials dealt with creep of plastics, power-loss

of tires, static-electrical effects on textile fabrics, compressive properties of

tooth enamel and dentin, and dimensional stability and detail reproduction of

elastomeric dental impression materials.

63
Degradation of Collagen. To provide basic information on the properties of leather, the Bureau is investigating the processes that occur in the

degradation of collagen, the white connective tissue of hides from which

leather is made. Collagen is a complex protein containing 17 amino acids.

The tensile strength, elasticity, toughness, and pliability of leather are

attributed to the fibrous matrix and molecular structure of this natural

polymer. However, under certain environmental conditions these properties

change and the leather deteriorates. These factors are of prime concern to

tanners, leather manufacturers, and industrial users of leathers.

Degradation of collagen, which is caused by heat- and gamma-radiation,

was studied in steer-hide powder and kangaroo-tail tendon. For the tests,

the specific amino acids affected were determined, the solubility and shrinkage temperature observed, and the water-vapor absorption and ultraviolet

and infrared absorption measured. Those amino acids which have sulfur

and hydroxyl in their side chains (such as methionine, serine, threonine, and

tyrosine) were found to be most susceptible to both heat and gamma radiation; alanine, glycine, hydroxyproline, proline, and arginine were least

affected.

Little damage to amino-acid structure was noted at radiation doses of less

than 20 megarads. Heat degradation but not radiation degradation was

accelerated by oxygen and moisture. On the infrared spectra of the most

severely heat-degraded materials, some small change was noted in the spectral region of 7 to 9 microns. High ultraviolet absorbence by the watersoluble fractions of the irradiated material is attributed to formation of

specific complex absorbing groups.

Water Penetration Test for Sole Leather, Dynamic testing equipment has been developed to measure the resistance of sole leather to water

penetration. The apparatus for this test automatically flexes the leather

specimen, with one side exposed to water, until penetration occurs. Flexing

greatly accelerates the rates of penetration and absorption of water as compared to rates under static conditions.

Factors that influence penetration and absorption under the dynamic

conditions are thickness of the specimen, location on the sole leather bend,

compression of the specimen, tannage, and impregnating materials. Chromeretanned crust leather showed higher resistance to water penetration than

vegetable-tanned crust leather, but both types of leather were considerably

less resistant than finished vegetable-tanned leather.

Impregnating the vegetable-tanned crust with polymers increased the

resistance to water penetration and water absorption 20-fold. Thus, the

dynamic water-penetration test will be useful in developing impregnants to

improve water repellancy in sole leather.

Power Loss and Operating Temperature of Tires. The high-speed

highway has accentuated the importance of power loss and operating tern

perature in tires. To study this problem the Bureau has measured overall

power loss by using two dynamometers—one to measure the power input

and the other to measure the power output from the tire. In the investiga64
tion, it was found that tire construction and type of rubber are predominant

factors influencing the power loss and operating temperature. These factors

determine the manner in which power loss changes with speed, load, and

inflation pressure. The inclusion of natural and synthetic rubber in the

same tire has an adverse effect on power loss.

The operating temperature was found to be a function of the power loss,

rate of heat transfer within the tire, and rate of heat transfer from the tire

to the environment (road and air). At high speed, the first two factors

govern the tire temperature.

Glass Transitions in the Rubber-Sulfur System. The volume-temperature relations for mixtures and vulcanizates of rubber and sulfur have

been measured by using an automatic recording interferometer. The results, covering a temperature range from —180° to +150° C and a composition range from 0 to 30 percent bound sulfur, supplement earlier Bureau

data. In each case a discontinuity in slope is observed at a characteristic

temperature, the glass transition point, below which the material loses its

rubberlike properties and becomes a hard rubber. A linear relation is noted

in each case above the glass transition temperature; below this temperature

the slope decreases with diminishing temperature. The glass transition temperature of the mixtures is independent of sulfur composition. However,

the transition temperature for the vulcanizates increases with rising sulfur

content along a sigmoid curve from — 69° to + 90° C.

Interlaboratory Studies of Test Methods, Two problems of present

concern to industry are: How to determine which of two test methods gives

the more sensitive and precise results; and how to explain the lack of agreement in results obtained by different laboratories which use the same test

method. A new mathematical theory underlying the comparison of results

from different laboratories is being applied by the Bureau to interlaboratory

comparison of test methods (see also 2.11, p. 95).

When the average value obtained by any particular laboratory for a given

material is plotted against the average obtained by all the participating

laboratories, the points corresponding to the various materials are found to

lie approximately on a straight line; hence the theory has been given the

name "linear model." An interlaboratory study based on this model makes

it possible to describe and assess the relative importance of the different

sources of availability and to determine how many replicate measurements

are needed. The linear model has been applied successfully to studies of

three important methods in the pulp and paper industry—tensile strength,

airleak smoothness, and determination of pentosans—and to the development

of a tentative standard reference paper for calibrating the internal tearing

strength method.

Electrical Resistivity of Fabrics. The comfort and appearance of

clothing when worn under cool, dry conditions is appreciably affected by

static electricity. However, uncomfortable effects can be alleviated by applying textile finishes which reduce the fabric's surface electrical resistivity.

65
The tendency of many fabrics to accumulate static electricity affects their comfort, appearance, and other qualities. This apparatus is used in evaluating

treatments used to counteract the static effect (page 65).

To evaluate the effectiveness of these finishes, equipment was constructed, in

cooperation with the Army Quartermaster Corps, for measuring the resistivity

of fabric samples. For experiments, temperature could be varied between — 60° and + 120° F and relative humidity, between 4 and 98 percent.

Results indicate that surface resistivities less than 1012 ohms/square are

desirable for satisfactory antistatic behavior. Only a few of the antistatic

finishes tested were effective at low-relative humidities. Cotton has a re- sistivity of 1010 ohms at 50 percent relative humidity and 70° F and thus

requires no treatment for use in this environment; however, it exhibits pronounced electrostatic effects under lower temperature and humidity conditions. The surface resistivities of cotton, nylon, and wool fabrics were all

greater than 1035 ohms in dry air at 32° F.

Surface Tension of High-Viscosity Liquids. As part of an investigation of the mechanism of reinforcement in glass-fiber-reinforced plastics

sponsored by the Navy Bureau of Aeronautics, a versatile instrument was

developed to measure surface tension of high-viscosity liquids. For the

apparatus, a tensiometric technique utilizing a strain-gage-type testing machine was modified by adding a platinum-iridium ring. This ring enables

full-scale readings with only a 2-gram load.

With this technique the load on the ring as a function of the ring displacement is continuously recorded, and the effect of the ring-displacement

rate on the maximum loads (i.e., the surface tension), can be determined.

Beside its use in the rapid, routine determination of the surface tensions,

the method provides a simple technique for characterizing the physical

properties of liquid surface films and for studying the effects of a number

of independent variables on such films.

66
Creep of Transparent Plastics. Plastic windshields and canopies of

highspeed aircraft may undergo serious creep deformation at high temperatures colated by aerodynamic heating. Under sponsorship of the Navy

Bureau of Aeronautics, the creep behavior of transparent plastics exposed to

temperature conditions simulating those encountered by aircraft windshields and canopies has been investigated. The heat conditions applied to

the plastics include uniform temperature, temperature gradients, and shock

heating. The temperature gradient corresponds to the condition encountered

in level flight of an aircraft and the shock heating simulates thermal conditions during a dive of an aircraft. Results indicate that plastics withstand

higher surface temperatures without serious creep deformations when ex- posed to temperature gradients and to shock heating than when exposed to

uniform temperatures.

Radiation-Resistant Polymers. Radiating a polymeric substance may

cause several types of chemical change, depending on molecular structure.

Chains may be either broken or crosslinked, or some of the branched atoms

may become detached to form small volatile molecules. In addition, relatively large amounts of unstable or reactive species (free radicals) are produced, some of which have unusually long lifetimes because of the slow diffusion of long polymer chains.

Investigations are being conducted for the Air Force on the radiation effects of polymeric stability. A knowledge of the mechanisms and reactions

will enable prediction of the effects of such energy on materials and the production of suitable materials. To establish the mechanisms of the chemical

reactions initiated by radiation, electron spin resonance is being used to

characterize the free radicals produced, a zero strength tester to measure the

change in polymer strength after irradiation, and the mass spectrometer to

determine the volatile substances produced. Many other techniques are

being employed.

Recently, it was observed that polytetrafluoroethylene degrades at least

100 times more slowly in the absence of air or oxygen. Thus, the polymer

may be extremely useful under conditions (such as satellites in the upper

air strata) where, although radiation is present, oxygen is avoided.

Crystallization of Crosslinked Polymers. When polymer molecules

are intermolecularly crosslinked by either chemical means or by the action of

high-energy ionizing radiation, a three-dimensional insoluble network is

formed. If the network is composed of chains of sufficient regularity, crystallinity can develop at appropriate temperatures without any deformation.

Detailed studies of the melting and crystallizing behavior of such systems

have shown that these properties are dependent on the number of crosslinks

introduced and on the relative arrangement of the chain units at the time of

network formation. For networks formed from chains that are randomly

arranged, a substantial depression in the melting temperature is observed

with crosslinking. Consequently at a given temperature the rate of crystallization is retarded.

67
In contrast, for networks formed from ordered chains, as in the case of

fibrous natural rubber or of crystalline but nonoriented polyethylene, the

melting temperature is only slightly affected by the introduction of crosslinks.

Thus the rate of crystallization for ordered chains is not as severely retarded.

At temperatures above the melting temperature these networks represent a

new type of partially ordered liquids.

Thermal Stability of Polymers, At the request of the Air Force

the Bureau has undertaken a research program on the thermal stability of

polymers at temperatures up to 1,200° C. The products of pyrolysis were

fractionated and analyzed by mass-spectrometric, microcryoscopic, microchemical, and infrared methods. These studies have provided a better understanding of the relationships between thermal stability of polymers, and

their chemical composition and molecular structure. For example, vinyl

polymers yield volatile products containing from 0 to 100 percent monomer,

in proportion to the amount of tertiary and quarternary carbons in the

chain. Pyrolyzed polymers that are highly crosslinked or in which cross- linking develops during pyrolysis, yield a carbonaceous residue. In the

temperature range 150° to about 500° C, fragmentation of the polymer is

due chiefly to the primary effect of heat on the polymer. At higher temperatures there was further break up of the fragments due to the intense

heat.

Interactions in Polymer Solutions. The commercial significance of

high polymeric substances such as fibers, rubbers, and plastics has resulted

in the rapid rise of new and major industries. Essential to the developResearch on the synthesis and radiation-resistance of aromatic fluorocarbons

is aimed at determining basic principles needed for guidance in the production

of solid polymeric materials having increased stability. Polymers are sealed

in a special Dewar (left) in order to control the temperature of their environment, and then are exposed to gamma rays from a cobalt-60 source submerged

in a pool of water (right) (page 67).

68
ment and improvement of synthetic polymers is a knowledge of the structure

and behavior of the macromolecules in solution and in the solid state.

When polystyrene is dissolved in cyclohexane near room temperature, the

polymer-polymer interactions are nearly equal to the polymer-solvent interactions. In an investigation of such solutions, the exact temperature (theta)

when these interactions are equal was found to vary considerably, depending on the nature of the end groups and the length of the polystyrene molecule. The temperature dependence of the refractive index increment of

polystyrene in cyclohexane and toluene solutions was accurately determined

and was found to agree with results calculated by other methods.

Physical Properties of Tooth Enamel and Dentin, Few data are

available on the physical properties of tooth enamel and dentin because of

the difficulty in preparing and measuring the very small specimens involved.

In a project sponsored by the American Dental Association, and the Federal

dental services, methods have been developed for preparing small cylindrical

specimens of tooth structure and measuring their stress-strain properties in

compression.

The specimens of enamel and dentin were shaped with a diamond instrument in a dental hydraulic handpiece. Properties varied rather widely,

depending on the specimen's original location in the tooth and, for enamel,

the orientation of the specimen. Highest values for enamel were obtained

for the cusp ; intermediate values for the tooth sides ; and lowest values for

the occlusial surface. Dentin had a higher compressive strength but a lower

modulus of elasticity than did enamel. Data derived for the study will be

used in evaluating dental-filling materials, in designing cavity preparations,

and in demonstrating physical changes in teeth.

Elastomeric Dental Impression Materials. Dentists have recently

been using synthetic elastomeric materials to make impressions for artificial

dentures and gold inlays for restoring teeth. The properties that control

accurate reproductions were investigated in cooperation with the dental services of the Armed Forces and Veterans' Administration. Two types of materials—polysulfide polymer base and silicone base—were examined and test

procedures were developed for measuring detail reproduction and dimensional stability.

Synthetic elastomeric materials were found to return to original dimensions as well after compression as the hydrocolloidal impression materials

which were previously used. In addition, the elastomers have much greater

dimensional stability on prolonged exposure to normal room-atmosphere

than to agar-agar and alginate base hydrocolloidal materials. For greater

accuracy with elastomers, the gypsum cast of the impression should be made

immediately after the impression is removed from the mouth.

Dental Fluorometer. Human teeth fluoresce when exposed to ultraviolet radiation. Healthy teeth emit a blue-white light whereas decayed

areas on the teeth emit a brownish light or none at all. If the pulp in an

injured tooth is dead, then the tooth shows reduced fluorescence.

In cooperation with the Federal dental services and the American Dental

69
Apparatus used to determine the compressive properties of human enamel and

dentin. Data derived from the study will be used in evaluating dental filling

materials, in designing cavity preparations, and in demonstrating physical

changes in teeth. Inset shows the tiny cylindrical specimen in place between

the pistons (page 69).

Association, a fluorometer has been developed which is capable of measuring

the fluorescence intensity of teeth and other tissues in the human mouth.

The fluorometer consists of a mercury vapor lamp equipped with a filter

that passes only ultraviolet radiation in the 3650 A region of the spectrum.

This radiation is focused onto the tooth by a special objective. The tooth

absorbs the invisible ultraviolet radiation and emits blue-white visible light.

This light is collected by an annular lens around the central objective and is

focused onto a photomultiplier detector.

Dental X-ray Radiation. As an aid to the dental profession a motion

picture showing the dentist how diagnostic X-ray pictures may be taken with

a minimum amount of radiation to the patient was produced in cooperation

with the American Dental Association. Procedures by which the dentist can

check his X-ray equipment for collimation and filtration of the useful beam,

70
for tube head leakage and for adequate length of the timer cord, are shown.

The movie also demonstrates how the dentist can reduce radiation to the

patient by the use of high-speed film with the 80,000 X-ray machines currently available in dental offices.

2.8. Metallurgy

Metallurgical research at the Bureau is directed toward a better understanding of the properties of existing metals in order that improved metals

and alloys may be developed to meet new requirements or to give better performance. Much of the work is designed to furnish basic information on

metals and alloys in terms of their constituent atomic units. The studies

also include the effects of treatment, fabrication, and conditions of service

on the structure, behavior, and properties of metals, with particular emphasis

on metals subjected to high temperatures. Other investigations concern the

causes of metal fatigue.

The complex destructive process of corrosion is investigated from several

directions. During the past year studies were made of corrosion reactions

at the metal surface, the effects of free radicals on metals at low temperatures,

and the mechanism of stress corrosion. These and related programs help

not only to maintain a vigorous and effective competence in metallurgical

science, but to advance metals technology by providing data on the basic

properties of matter.

Heat-Resistant Materials. To obtain basic data that will be used in the

design of improved heat resistant metals, studies are being made of the solidstate reactions occurring in alloys of chromium, iron, nickel, and molybdenum. Reports are now being prepared on the chromium-nickel phase diagram, the structure of certain intermetallic compounds, and the solid-state

reactions in the iron-nickel molybdenum system.

Creep of High~Purity Nickel. An investigation of the creep properties

of high-purity nickel, initially as cold-drawn 40 percent reduction in area,

showed that resistance to creep at temperatures below 900° F was significantly increased by cold drawing. At temperatures above recrystallization,

however, this strengthening effect was eradicated. None of the existing

equations was considered suitable to express or predict the creep test results

with high accuracy since the structural changes accompanying the creep

process have not yet been adequately defined.

Tensile and Yield Strengths of Die Steels. An evaluation was made

for the Navy Bureau of Aeronautics of the tensile and stress-rupture properties at high temperatures of four commercial heats of hot-work die steel of

the 5-percent chromium type. While the life of some of the stress-rupture

specimens tested at 600° and 800° F under loads of 90 to 95 percent of the

tensile strengths was exceedingly long (tests stopped after 1,000 hr), other

specimens failed almost immediately upon loading. Moreover, increased

tensile and yield strengths at room temperature were observed in the specimens that did not fail at the higher temperatures. Further tests are being

made to determine the cause of this behavior.

71
Crystalline Diffusion, Diffusion in crystals often occurs by the movement of vacant lattice sites through the crystal. In these cases, the diffusing

atoms do not move by a series of random jumps. The correlation effect

between the directions of successive jumps was theoretically investigated

in studies of impurity diffusion and diffusion in a chemical concentration

gradient. Expressions were derived which permit the calculation of atom

jump frequencies from the experimentally determined diffusion coefficients.

Fatigue Properties of High-Strength Steels. Recent Bureau experiments indicate that retained austenite in the matrix of high-strength steels

lowers the fatigue strength. The results also showed that fatigue stressing

transforms retained austenite to untempered martensite, which probably

causes the deleterious effect. These findings, made in tests on four different

low-alloy steels with carbon content ranging from 0.44 to 1.06 percent, are

expected to have practical applications in the processing of high-strength

steels used throughout industry, and in the choice of steels for critical parts

such as missile casings and aircraft structures.

Surface Reactions. In a study for the National Aeronautic and Space

Administration on the influence of surface reactions in metal fatigue, it was

found that polar organic compounds are much more effective than nonpolar

organic compounds in improving the fatigue resistance of metal specimens.

It has been known for some time that an oil film applied to a specimen sur- face gives some protection, and the present study indicates that the efficacy

of the polar compounds in particular is due to their ability to prevent

moisture from coming in contact with the metal surface.

Dislocations in Aluminum Alloys and Brass. In investigating the

arrangement of dislocations (line imperfections) in aluminum alloys, single

crystals of aluminum-copper alloys were subjected to several aging treatments to bring about precipitation of the CuAl2 phase. The experiments

showed that the precipitate particles are nucleated preferentially along dislocations, and then grow in a manner dictated by the crystal structure of both

the matrix and the particles. As a result of the aging treatments used, the

particles appeared as large needles. In some regions of the crystals the

needles were oriented in the [112] directions. Observations were made with

a projection X-ray microscope having a resolution of 1 to 2 microns.

Plastic deformation of a metal in one direction increases its resistance to

further deformation in that direction, but greatly decreases its resistance to

deformation in the opposite direction. This phenomenon, known as the

Bauschinger effect, is being studied to develop information on the behavior

of dislocations during deformation. An attempt is also being made with

X-ray diffraction techniques to correlate the changes in the misorientation of

the crystal lattice with changes in mechanical properties. It has been found

thus far that in brass specimens a large part of the Bauschinger effect can

be eliminated by heating at only 300° F.

Growth of Metal Crystals from Their Vapor. Experiments are in

progress in the metal physics laboratory to evaluate the Burton, Cabrerra,

Frank theory of crystal growth as applied to a simple, well-characterized

72
system. The theory, based on a growth mechanism through screw dislocations, has been qualitatively confirmed by the observation of growth spirals

on a number of crystals, but quantitative confirmation is lacking because of

the scarcity of experimental data. In the present work, a technique has been

developed for measuring the weight of a metal crystal, growing in contact

with its supersaturated vapor, as a function of time. Zinc crystals are being

grown under various conditions of supersaturation. A method is being

developed to convert the weight-versus-time curves obtained in these experiments to rates of growth.

Nuclear Magnetic Resonance, In pure indium metal, its nuclear magnetic resonance is not observed because of the metal's electric quadrupole

moment and noncubic crystal structure. Recent experiments were therefore

initiated with investigations of both the lead and indium resonances in alloys

of these two metals. The indium atoms were dispersed in a cubic matrix of

lead atoms which eliminated the quadrupole effects, and thus permitted a

determination of the indium resonance in the metallic state. The shift of

resonance (Knight shift) of the indium in these alloys was determined with

relation to the shift exhibited by indium in indium-antimonide, a semiconductor.

Tuning in on the atomic nucleus. The nuclear magnetic resonance of metals

and alloys is studied with the aid of a tuned radio transmitter and receiver.

The metal sample is in the probe between the poles of an electromagnet (see

page 73).

73
Corrosion Research

Stress Corrosion Cracking. Stress corrosion studies during the past year

have been supported jointly by the Corrosion Research Council, the

Atomic Energy Commission, and the Bureau. In one laboratory study, the

progression of stress corrosion cracking in low carbon steel, magnesium, and

stainless steel was successfully stopped by the application of cathodic currents. The significance of very high local stress concentrations in stress

corrosion of low carbon steels was also established. A specimen was designed in which most of the variables can be controlled, and it was used to

produce stress corrosion cracking in type 304 stainless steel exposed under

stress at 450° F while in contact with an aqueous solution of 100 ppm sodium

chloride. This specimen, serving as an autoclave, eliminates the difficulties

ordinarily encountered in using autoclaves, and thus improves the precision

of measurements.

Single Crystals. Studies of the influence of crystallographic

orientation on the rate of film formation on copper single crystals immersed

in oxygenated water were continued under the sponsorship of the Corrosion

Research Council. A polarizing spectrometer was used to measure the rates.

The experiments showed that an oxide film forms at the slowest rate on the

octahedral face of copper, and somewhat more rapidly but at about an equal

thickness on the cubic and dodecahedral faces. Pitting corrosion of highpurity iron single crystals was found to depend also on crystallographic

orientation, with the dodecahedral face showing the greatest number of pits

per unit area. Free Radicals. The effect of free radicals on copper single crystals

was studied at temperatures as low as 4° K. When reheated to

room temperature, specimens that had been treated with oxygen passed

through a microwave discharge (and therefore containing some atomic

oxygen) were found to be covered with a stable film about 20 A thick.

On specimens similarly treated with molecular oxygen, no film formation

was observed. In similar studies, the refractive index of different gases

condensed on gold was accurately determined for the first time. The gases

included oxygen, ozone, water, carbon dioxide, nitrogen, argon, krypton,

and ammonia. For details of the Bureau's free radicals program, see p. 36.

Preferentially Oriented Crystals. A method was developed for growing

oriented single crystals of aluminum in many different shapes. A preselected orientation was obtained with a technique known as "seeding,"

and the desired cross-sectional shape was produced by growing the crystals

in a vertical furnace. These specimens will be used to determine the relationship between lattice deformation and corrosion rates.

Uranium Alloys, In continuing studies of uranium alloys for the

Atomic Energy Commission, it was found that small additions of any of the

six platinum metals lower the melting point of uranium to certain minima,

but the addition of more metal results in the formation of high melting point

compounds. Binary phase diagrams of uranium and the platinum metals

74
are being constructed. The existence of stable or metastable compounds,

the presence of autectics and reaction horizontals, and the limits of solid

solubility, as observed in the uranium-platinum diagram, are of practical

significance in any uranium material.

The fissioning of uranium atoms in a power reactor results in the appearance of a number of metal atoms that may or may not be beneficial ; however,

to recover the uranium, these fission products must be removed. In pyrometallurgical experiments during the year two of the elements most difficult

to separate from uranium (ruthenium and molybdenum) were removed by

forming ruthenium-rich and molybdenum-rich compounds. The pyrometallurgical method also proved feasible in separating uranium as a uraniumcadmium intermetallic compound.

Improved Gage-Block Materials. Further experiments confirm a previous tentative finding that nitrided 410 stainless steel appears exceedingly promising as a material for ultra-precise gage blocks. The nitrided

specimens were found to be corrosion-resistant to atmospheric and perspiration conditions. Moreover, their gaging surfaces are extremely hard and

wear resistant, and can be finished to high degrees of smoothness, flatness,

and parallelism. Measurements of nitrided 410 stainless steel blocks over a

1-year period indicate that they have the required dimensional stability as

The effects of

atomic oxygen

on copper single

crystals were

studied at temperatures as low

as 4°K (left).

A method for

growing and

studying preferentially oriented

aluminum crystals (above)

was developed

to determine the

role of crystal

orientation in

the corrosion

process (page

74).

531788 O—60 6 75
Annealed 410 stainless steel gage blocks nitrided in this equipment (right) are highly stable and corrosion-resistant. They represent a step forward in re- search directed toward the regular calibration of gage blocks to 1 part in

10 million. Insets: Photomicrographs of unnitrided (above) and nitrided (below) 410 stainless steel (page 75).

well as a substantially better stability than the best commercially available

steel blocks (see p. 26). These results, however, cannot be considered

conclusive because observations of commercial blocks over a 25-year period

show that the results of measurements made for only a 1-year period are not

necessarily indicative of future behavior.

Titanium Data Charted, Titanium and titanium alloys have relatively

high strength-to-density ratios, and strongly resist attack by corrosive media.

Hence they have considerable potential use in aircraft, airborne equipment,

and chemical processing equipment. In designing for their successful application in these areas, however, engineers need information on the effects of

low temperature, stress concentration, and stress system on the mechanical

behavior of these metals. A study to obtain these data on annealed commercially pure titanium was, therefore, recently completed.

Tensile tests were made at 100°, 25°, -78°, and -196° C on circumferential notch specimens of different geometry. In general, the strength

of the titanium increased with a decrease in temperature or an increase in

triaxiality, independently of the stress concentration. Ductility decreased

greatly with decrease in temperature or with an increase in either triaxiality

or stress concentration. Thus, the increase in strength was usually accompanied by a decrease in ductility. The ductility of the specimens in which

76
the fracture crack was initiated at or near the root of the notch by stress

concentration was usually less than that of specimens in which the fracture

crack was initiated at or near the axis by triaxial stresses.

The results clearly demonstrate that the tensile behavior of unalloyed

titanium at low temperatures cannot be accurately predicted from data obtained at a single temperature with specimens of a fixed notch geometry.

The results also emphasize the importance of taking special care to eliminate

notches. If they are unavoidable, attempts should be made to mitigate their

embrittling effect by designing a notch with the largest permissible root

radius.

Stainless Steel Properties Evaluated. An evaluation of the mechanical properties and microstructures of 17-7 PH (17 percent chromium-7 percent nickel) stainless steels was completed for Wright Air Development Center. Optimum mechanical properties at room temperature were obtained

by a heat treatment slightly different from that recommended by the manufacturer. However, the best tensile and stress-rupture properties at 600°

and 800° F were obtained by treating specimens as recommended. A definite embrittlement resulted from long-time exposures (100 or more hours)

of heat-treated specimens at 800° F, with or without stress, but original

properties were restored by reaging. No significant embrittlement was observed for similar specimens exposed at 600° F.

Unsuccessful attempts were made, by means of X-ray and metallographic

examinations, to ascertain the mechanism of aging, and the identification of

the precipitation-hardening compound. As precipitation-hardening stainless steels are now widely used both in missiles and in military arcraft, a study will be made of the structural and mechanical properties of foils of

these steels as affected by heat treatment. Recently developed techniques

for the direct observation of thin metal films with the electron microscope

will be used.

2.9. Mineral Products

The Bureau conducts both fundamental and applied research on a wide

variety of inorganic, nonmetallic materials. The primary objective of this

work is the accumulation of basic data on the general properties, constants,

structure, and behavior of these materials as an aid to both the producers

and users of glass, refractories, porcelains, pottery, enamels, cermets, and

cements. Because of the increasing need of fundamental knowledge to

develop materials that can be used for structural purposes at high temperatures, more emphasis has been placed on high-temperature investigations.

New Data on Ferroelectric Materials. The ferroelectric oxides, of

which barium titanate is the prime example, are important materials because

they have wide applications as dielectrics in capacitors, as accelerometers,

as memory devices for electronic computers, and as transducers in ultrasonic generators. Many ferroelectric properties of a substance, like those

of ferromagnetic materials, are "structure-sensitive," that is, they depend

strongly on such nonbasic properties of the specimen as grain size, impurity

77
content, distribution of internal strains, and lattice defects. To gain increased understanding of the behavior of these materials, it is necessary to

study the properties and their effects. The Bureau is seeking to explain

the electrical and magnetic properties of nonmetallic inorganic compounds,

i.e., ceramics, in terms of structure.

To obtain reproducible measurements, several factors must be considered

in studying these ceramics. The measurements are affected by environmental

conditions (such as temperature and moisture), and by specimen preparations. To attain specimen uniformity, single crystals in pure form and with

selected impurities are now being produced for experiments. To date,

large aluminum oxide crystals have been grown and 50:50 (BaSr)Ti03 (barium strontium titanate) crystals are being prepared.

By the addition of as little as 0.01 percent of the rare earths neodymium

or samarium, the electrical conductivity of barium titanate at room temperature can be changed from values of the order of 10~10 to about 10~2 (ohmcm) -1

. Above the Curie point, however, the conductivity decreases drastically by several orders of magnitude. Such an effect may be due either to

a large change in the mobility or number of charge carriers. Single crystals

are being used to study this effect and to check the validity of a proposed

association of porosity, resistivity, and thermoelectric effect (Seebeck coefficient).

Phase Changes in Silicates. Cementing materials, including portland

cement, are used in great quantities in the construction of highways, dams,

missile takeoff pads, and nearly all types of buildings. These materials are

complex products whose manufacture and use are still guided to a considerable extent by the long experience that has accumulated during the development of our flourishing concrete technology. The fundamental chemistry

and physics of the processes are not completely understood, and therefore

the guidance of fundamental knowledge toward possible new practical improvements is lacking. Some of the studies of high-temperature chemistry

in silicates at the Bureau are designed to reveal such fundamental properties,

structures, and mechanisms.

One study concerned dicalcium silicate, an active constituent of portland

cement. The beta to gamma transformation of this substance, one active

constituent of portland cement, exhibits a violent crystal inversion which

causes crackling and dusting of the solid. The phenomenon is a significant

industrial problem in the manufacture of portland cement. It is also ex- hibited by other compounds having analogous crystal structures, such as potassium sulfate.

As part of a research program partly supported by the Portland Cement

Association, the polymorphism of dicalcium silicate was studied with hightemperature X-ray diffraction equipment developed by the Bureau. It was

found that dusting occurs when the transformation of a sample is essentially

complete. However, dusting does not occur when the substance includes cer- tain impurities or is kept within certain temperatures, even though the transformations may be extensive. A critical temperature was found at about
1,420° C, considerably above the /^-stability range, which controls the character of the transformation from (3 to the lower-temperature form. On cooling, samples without "protective" impurities showed dusting if they had been

heated just above the critical temperature, but not if kept just below. The

mechanism of this effect, and of the stabilization by impurities, is being

studied by X-ray analysis of the crystal structures.

Strength of Glass at Elevated Temperatures. Inorganic transparent

glasses are being considered for many applications at high temperatures.

However, data on the mechanical properties of glass at high temperatures

and the methods of obtaining such data, are insufficient. Thus the Wright

Air Development Center is supporting a program for determining the mechanical properties of glasses over a wide temperature range. The data

obtained aids the glass industry in improving presently available glasses as

well as developing new high-temperature glasses, and enables the aircraft

industry to better utilize the glasses that are available.

The modulus of rupture and the modulus of elasticity of a number of

glasses were measured over a range of temperatures and after different heat

treatments. Some compositions of annealed glass show an increasing

strength and increasing modulus of elasticity with increasing temperature

while other compositions decrease in both strength and modulus of elasticity

with increase in temperature. Stress-rupture and creep tests have been

made at room and elevated temperatures and the rate at which strength and

tempering strain of tempered glass decreases at elevated temperatures has

been measured.

Ferroelectric oxides have wide applications in capacitors, accelerometers, electronic computers, and ultrasonic generators. The equipment at right is used

to measure the dielectric properties of such materials in constant-temperature

environments. At left is a furnace used in growing single crystals of inorganic nonmetallic materials for study (page 77).

79
Infrared Transmitting Glasses, Glasses have many advantages over

other materials for use in the infrared range. The optical properties of a homogeneous glass are constant in all directions, and crystal orientation is

not a factor in the grinding and polishing process. A variety of refractive

index values can be produced by appropriate composition changes, and most

glasses are not affected by atmospheric moisture as are many crystalline

materials.

Because little refractive index data on glasses are available for wavelengths

beyond about 2.5 yu, the Navy Bureau of Ordnance asked the Bureau to

undertake a special study. In cooperation with the Eastman Kodak Co., the

refractive indices of 13 optical glasses and about 30 experimental glasses

have been measured over the wavelength range from 0.43 to 4.25 ji. Transmittance curves for three thicknesses of the same glasses were also determined, from which absorption coefficients were calculated. Results of these

experiments have been published.

An important problem in the use of glasses in infrared devices is the

presence of an absorption band in the vicinity of 2.8 /x. This band is usually attributed to (OH) ~~ radicals in the glass structure. The various methods which were used to reduce the absorption band are difficult for practical purposes outside the laboratory and may not be feasible in large-scale

manufacture of glass. However, it was found that the addition of fluorides

in the batch reduces the intensity of the water band. Relatively large

amounts of fluorides can be used as a component of certain glass batches

without causing opalescence or turbidity in the resulting glasses—if certain

oxides, such as lanthanum oxide (La203 ) or tantalum oxide (Ta2 03 ) are

also included. While this method was used only on a laboratory scale, it appears applicable to melts of any size.

Physical and Chemical Properties of Glass Surfaces, A long-range

study of the surface groups of inorganic nonmetallic solids (i.e., the groups

terminating the bulk structure) and of the effects of the proximity of the

surface upon subsurface domains has been initiated.

One phase of this research is concerned with transport phenomena through

vitreous silicates. Improved techniques have been designed to follow the

movements of alkali ions through silicate glasses induced by electrical potentials and by concentration gradients. When glass is immersed in a diffusion sink, such as liquid water of a constant high purity, mobile alkali

ions at the surface migrate from the vitreous material. This outward migration produces a deficiency of alkali ions at the surface and thus creates a concentration gradient within the glass. The gradient causes more alkali

ions to flow through the vitreous material to the surface. An electrophoretic system removes the alkali immediately after entering the water, thus

maintaining a constant pH. The electrophoretic current in the system is

recorded and evaluated in terms of ionic flux from the glass surface.

The experimental values for the alkali flux from the glass surface and its

activation energy are compared with theoretical curves derived from various

80
diffusion models. Conclusions are drawn concerning the transport mechanism. Further experimental work is aimed at obtaining concentration

profiles through the surface domains which will serve as an additional criterion for the validity of proposed models.

Impact Coating for Rockets and Missiles, Nearly pure oxide coatings can be applied by projecting small molten particles against a metal

surface. The resulting coatings, which are extremely hard and refractory,

have numerous applications in missiles, rockets, and satellites. For ex- ample, a flame-sprayed alumina coating was applied to the outer skin of one

of the Explorer satellites; other possible applications are in rocket nozzles

and reentry nose cones. The metal surfaces are covered with the refractory oxide by using such

devices as flame-spray, plasma-jet, and shock-wave techniques. Existing

knowledge regarding the application of these various types of particleimpact coatings is principally of an empirical nature; little is known of the

scientific principles. To fill this gap, a basic investigation is being conducted for the Wright Air Development Center. Among the techniques of

study that have been employed during the first year are high-speed photography, and microscopic examination of particles that adhere to glass slides

upon impact.

Results obtained so far have helped to clarify certain mechanisms of the

process. For example, it was found that molten particles from a rod-type,

oxyacetylene gun are ejected from the gun in a series of spurts. Measurements with a streak camera, and with a rotating-disk velocimeter, indicated

that the particles in each burst undergo acceleration during the first 3 inches

of travel, beyond which their velocity progressively decreases. Practically

all of the particles that adhere were found to be molten at the moment of

impact. Flow of the coating material at this juncture is dependent upon

the condition of the surface as well as its thermal properties.

Thermal-Radiation Standards for Space Vehicles. The successful

launching of earth satellites, accompanied by increased emphasis on ballistic missiles and rockets, as well as design studies of vehicles for space

travel, have resulted in an urgent demand for data on the heat radiation or

thermal emission and absorption characteristics of a wide variety of materials. The metallic outer skin of a satellite or other space vehicle may be

completely or partially coated with an appropriate ceramic material to

control the temperature limits within which the overall balance between

absorbed and emitted radiant energy is achieved. Such coatings, used in

conjunction with an inner jacket of insulation designed for the purpose,

establishes internal temperature limits that are suitable for normal functioning of the instrument and occupants, if any. Because needed data on

absorptance, reflectance, and thermal emittance are not available, a number

of different laboratories have set up equipment for determining these properties. However, results obtained on the same materials in the different

laboratories have often been divergent.

81
Studies were made to develop strain gages and bonding cements which would

perform reliably at high temperatures. These are necessary to determine the

suitability of various construction materials for high-temperature applications.

Here wires are being spotwelded in place in one of the final steps of fabrication.

Inset shows a finished gage (page 81).

The Bureau has therefore undertaken a program for the Wright Air

Development Center to develop standard techniques and instrumentation for

the evaluation of spectral emittance, spectral reflectance, and solar absorptance. The study also includes establishment of procedures for the computation from spectra emittance data, of total emittance, solar absorptance,

and absorptance for thermal radiation from such sources as rocket exhaust

gases and nuclear weapons; also the selection, fabrication, and calibration

of suitable materials for use as working standards of spectral emittance.

Apparatus has been assembled that will directly record the ratio of the

intensities of radiation from (1) a metal specimen—with or without a

ceramic coating—that is heated by passing a current through it; and (2)

a laboratory blackbody furnace held at the same temperature. The appli*

82
cable range for this equipment is approximately from 250° to 1,000° C.

Other equipment has been designed for the evaluation of spectral reflectance

in the range 0° to 250° C under conditions simulating normal illumination

and hemispherical viewing.

Standard specimens have been prepared from polished platinum and

oxidized Inconel, and have been partially calibrated for normal spectral

emittance (in cooperation with the Radiometry Laboratory).

Phase Equilibria in Rare-Earth Oxide Systems. Phase equilibrium

studies of any chemical system are concerned with the effect of variations

in environmental conditions (temperature, pressure, and composition) on

the stability and chemical composition of coexisting phases—gas, liquid, or

solid—of the system. Data on phase equilibrium are of vital importance

for knowledge of the stability of high-temperature materials, formation of

glasses, cements, metallurgical slags, and various alloys. Through use of

heterogeneous equilibrium phase diagrams, experimental data on such combinations can be systematically correlated and extended to predict behavior

for compositions and experimental conditions not yet explored. Such data

are particularly important for a complete understanding of the behavior of

ceramic products during firing and are most valuable as a source of information for the development of new products.

The oxides of the trivalent rare-earth ions are extremely useful refractory

substances, having melting points generally above 2,000° C. Phase equilibria studies on systems involving these oxides find application in such

fields as geochemistry, mineralogy, and ceramic technology.

As the initial step in a broad program, a reinvestigation of the polymorphism of the rare-earth oxides was undertaken. Previous work was

essentially confirmed showing that samarium oxide, europium oxide, and

gadolinium oxide have stable B-type structures at elevated temperatures.

Furthermore, it has been definitely established that all of the phase transformations occurring in the trivalent rare-earth oxides are nonreversible.

In addition, a survey was made of the subsolidus, solid-state reactions that

occur under equilibrium conditions for different combinations of the

trivalent rare-earth oxides. Selected compositions in over nineteen different

systems were studied by X-ray diffraction techniques. A graph of the

average ionic radius of the constituent cations versus all possible compositions of double oxides was drawn from the data to show specific regions of

stability for the various structure types found in these systems. From this

graph the subsolidus phase diagrams can be predicted for any multicomponent rare-earth oxide system.

Solid-Gas Reactions Involving Light-Metal Oxides. High-temperature thermodynamic data on the light elements—lithium, magnesium,

aluminum, and beryllium—and their compounds are essential for the prediction of chemical reactions at high temperatures and for a systematic

evaluation of prospective high-energy solid propellants for rockets (see 2.3,

p. 32). To obtain this basic high-temperature information, the energies

83
and equilibrium proportions of the light-metal oxides are being determined

in the solid, liquid, and gaseous states at pressures up to 100 atmospheres

and temperatures up to 6,000° K. A survey of the literature on solid-gas

and liquid-gas reactions involving oxides of the light elements has been

undertaken for the Advanced Research Projects Agency to obtain the most

precise values to compute tentative thermodynamic tables.

Using existing phase diagrams, new estimates of the heat of fusion of

alumina were obtained. The values varied widely and indicated that no

special merit should be attached to the currently accepted value of 26

kcal/mole. A new, but rough determination of the melting point of alumina

gave a value of 2,030±5° C. The limited amount of data, obtained with

the aid of a solar furnace, are consistent with the existence of a gaseous A10H

molecule at temperatures above 2,000° C.

Recent activity has been devoted to designing and testing equipment to

undertake three principal tasks : A more refined study of the vaporization of

A12 03 in water vapor using an arc-image furnace, a redetermination of the

vapor pressure, and study of the rate of sublimation of A12 03 above

1,600° C.

High-Temperature Strain Gages. Reliable strain measurements are

needed for analyzing stresses in structural materials for high-temperature

applications (see 2.6, p. 60). Such characteristics as strength, durability,

and dimensional stability are of critical importance in the components of

aircraft powerplants, aircraft wing structures, guided missiles, and certain

types of nuclear reactors. Conventional electrical resistance gages, which

consist of fine-wire filaments bonded with organic resins, are adequate for

use up to about 175° C; however, at higher temperatures the organic binder

deteriorates. To increase the temperature limit for this type of measurement, a prefabricated gage which could be bonded to test structures with

a ceramic cement was developed in a previous phase of this work, under

the joint sponsorship of the Bureau of Aeronautics and the Wright Air

Development Center. This gage, which has since been commercially produced, performed satisfactorily up to about 425° C, but above this temperature electrical leakage increasingly affected the measurements of strain.

During the past year a new cement composition was developed which has

higher electrical resistivity in the range 425° to 1,000° C than any known

commercial product. The greatest improvement was within a zone near

700° C, where the resistivity exceeded that of the best of the commercial

cements by a factor of 100.

Because a low cement curing temperature is essential for many applications of strain gages in testing large structures, a study was made of the

effect of cement curing temperature upon gage response. It was observed

that the uncured cements became conductive at intermediate temperatures,

with the result that the gages were short circuited. Application of a fused-on

ceramic coating to the resistance element and leads, prior to assembly of

the gages, prevented the short circuiting.

84
Dynamic Mechanical Properties of Refractory Oxides, Because of

the general trend toward higher temperatures in technology, the mechanical

properties of refractory oxides at elevated temperatures have recently re- ceived increasing attention. To extend the basic understanding of the

mechanical properties of various materials, and to relate these properties to

structural defects, dynamic resonance methods have been used for determining elastic and inelastic behavior of these materials over a wide temperature range ( - 190° to 1,700° C)

.

As part of a program to determine strength of ceramics at elevated

temperature, the strength of aluminum oxide single crystals (sapphire and

ruby) were studied between 600° and 1,000° C. Because of their heat- and

corrosion-resistant properties, materials such as aluminum oxide find application in aerodynamics where high-temperature load-bearing structures are

required. Such ceramics are also of special interest in electronics and

electrical insulators.

The strength of polycrystalline aluminum oxide is known to decrease with

increasing temperature above 800° C. However, in one set of measurements

on single-crystal aluminum oxide, crystal strength increased with temperature in this range. The study at the Bureau supports the theory that this

increased strength may be caused by very small amounts of plastic deformation. That is, failure may have begun at points where the local stress

was much greater than the average applied stress. Plastic deformation

might then have reduced the degree of stress concentration with the result

that a larger average stress could be sustained before failure occurred.

In another study, the effects of impurities are being studied by comparing

the results for high-purity materials with those of deliberately doped

specimens.

Infrared Absorption Spectra of Compounds Under High Pressure.

The basic characteristics of matter are determined by the nature of atomic

and molecular interactions. Although the broader aspects of interactions

between adjacent molecules are understood, a detailed evaluation has not

been made of the disturbances produced by interactions between more widely

separated molecules. Spectroscopic evidence has been found which shows

changes in molecular structures occur under pressures of 30,000 atmospheres. Reactions produced under such pressure may result in producing

denser phases or polymorphic forms having uniquely different properties

from those of the parent material. Infrared spectroscopy is used in this work

because the frequencies of absorption bands are determined by the characteristics of the molecular units present, such as the masses of the oscillating

units, the forces between them, and the force fields of adjacent molecules.

A pressure cell has been constructed using a pair of type II diamonds

for study of infrared spectra of solids in the 1- to 25-micron region. Spectra

can be studied routinely to calculated pressures as high as 60,000 atm and

occasionally to pressures of 100,000 atm or more. A large number of such

organic compounds as substituted benzenes, and such inorganic compounds

85
Refractory coatings have numerous applications in missiles, rockets, satellites,,

and in other high-temperature environments. Here an oxyacetylene gun is

used to flame-spray an aluminum oxide coating. Inset shows the flow behavior of a molten aluminum oxide particle impacting a hard surface (page

84).

as carbonates, nitrates, silicates, and sulfides, have been studied with special

emphasis on changes in bond characteristics caused by pressure. Infrared

patterns have been obtained on water, normal ice, and high-pressure forms

of ice. The data on the high-pressure forms of ice are the first that have

ever been obtained showing the change in bond characteristics between

hydrogen and oxygen.

Structure of Solids Containing Free Radicals, So great is the

tendency of most of the simple free radicals to combine with each other

that they cannot be obtained in a pure crystalline form and so must be

studied by other methods. Thus thin films, of the polycrystalline solids

formed by freezing gases on a cold surface are being studied by low-temperature X-ray diffraction techniques. From these experiments conducted in

connection with the Free Radical Program, the degree of crystallinity, bond

angles and distances, and structural changes that occur during warmup

are being determined. The information obtained is used in interpreting

the results of other types of experiments on solids containing trapped free

radicals (see also 2.3, p. 36)

.

Gases studied by this technique include nitrogen, argon, krypton, carbon

dioxide, xenon, diborane, oxygen, ozone, water, hydrogen peroxide, and

86
ammonia. These have been classified according to the degree of crystallinity of the solid formed by deposition at 4.2° K. X-ray diffraction patterns of the various crystalline phases have been recorded, and orientation

texture, annealing characteristics and polymorphism have been studied in

some detail.

Standard X-ray Diffraction Patterns. Standard X-ray diffraction

patterns in the form of card files, are widely used in research and industry as a rapid and accurate means of identifying crystalline materials. As part of a continuing program for the preparation of these patterns, the Bureau has

been studying and recording data in close cooperation with the Joint Committee on Chemical Analysis by Powder Diffraction Methods (ASTM and

American Crystallographic Association) . During the past year 70 standard

patterns have been published, and approximately 250 additional X-ray patterns have been indexed for inclusion in the Powder Data File. The ninth

volume of NBS Circular 539 (Standard X-Ray Diffraction Powder Patterns)

is in press.

2.10. Building Technology

The Bureau serves as a central agency of the Government for the advancement of scientific knowledge of building materials, structural elements, en- vironmental engineering processes, and safeguards in building construction

and maintenance. It also assists other government agencies in solving

special technical building problems. Research emphasis is directed toward

increasing knowledge about the factors affecting the performance of buildings, their facilities and equipment, the behavior of structures under various

conditions, and the nature of the physical processes that result in changes

in materials in different environments. Much of the data are used in the

development of specifications and standards prepared by technical organizations, and in manuals of design.

During the past year a new method was developed for measuring the

thermal conductivity of solid materials. Significant progress was made in

the development of technical data on the physical properties of insulating

concretes and joint sealing materials. Further progress was made on methods of determining the surface flammability of materials and new techniques

were applied in studies of the degradation of asphalts.

High-Temperature Thermal Conductivity. As part of a broad

research program concerned with the properties of materials at high temperatures, the Bureau has been studying methods for measuring the thermal

conductivity of insulations, solids, and metals at high temperatures. A new

method for determining thermal conductivity by a steady-state comparative

method was developed, applicable to homogeneous materials of low to

moderate conductivity in the form of flat slabs, or hollow cylinders A

comprehensive mathematical analysis of the method as applied to flat slabs

was made. A small apparatus based on the new method was built to measure

the thermal conductivity of explosives and solid propellants for rockets.

87
A larger apparatus for experimental purposes is being built of materials

that can be used over the temperature range from below —195° C to above

1,200° C. This equipment will replace the three separate sets of apparatus

currently in use that cover only the range from —170° C to 750° C. Potential advantages of the new method include the possibility of supplying

practically identical replicate specimens to other laboratories to promote

uniformity of thermal conductivity measurements, and the possibility of

conducting intercomparisons of thermal conductivity results obtained by

several distinctly different absolute methods.

Thermal Conductivity Reference Specimens. For several years,

various laboratories have submitted to the Bureau specimens of insulating

materials for an accurate determination of thermal conductivities. Laboratories use these specimens as references for calibrating thermal conductivity measuring apparatus. Requests for this service have been increasing. In order to satisfy such needs more quickly, and to avoid problems

arising from use of unsuitable materials, two materials having satisfactory

characteristics of homogeneity and stability (glass-fiber board and gum

rubber) were selected and stocked. Reference specimens can be prepared

from this stock and the thermal conductivity measured at the specified

temperatures. Such services are available under the cost fee schedule to

governmental, industrial, and university laboratories.

Physical Properties of Insulating Concretes. In recent years lightweight aggregate and cellular concretes have been used as thermal insulation for roofs, walls, and underground steam lines. In order to develop

satisfactory specifications for these materials, the Bureau has been studying

the properties of various insulating concretes for the Department of Defense.

The study includes cellular concrete containing no mineral aggregates and

concretes containing a lightweight aggregate, perlite, or vermiculite. Compressive and indentation strengths were determined as functions of composition and proportions, density, curing and age, moisture condition, and size

and shape of test specimens. The rate of drying and shrinkage were also

determined as functions of original moisture content, cement content and

aggregate type.

Joint Sealing Materials. The premature failure of joint sealants in

buildings, resulting in leakage of rain water through walls, is regarded as one of the most costly and troublesome problems in building maintenance

today. The Department of Defense asked the Bureau to study the properties

of the newest types of rubber-based mastics for sealing joints in structures

where movement is expected and air and watertightness is required. Some

of the properties being studied are adhesion, cohesion, durability at high

and low temperatures, staining tendencies, color retention, viscosity, flow,

and hardness. Behavior of the sealants in test joints :hat are extended in

width every 3 months are being studied under natural weather conditions.

A number of sealant manufacturers are cooperating in the program by

supplying the samples for the investigation and by exchanging technical

data pertaining to methods of testing.

88
Left: After being subjected to heating, soaking, and freezing exposures in the

laboratory, rubber-based calkings for masonry construction are tested for adhesion and cohesion in this machine. Accessory blocks used in the test are

concrete, brick, wood, and other building materials. Right: NBS test equipment which forms the basis of the recently issued Interim Federal Standard

for measuring surface flammability of building materials (pages 88, 89).

Mechanism of Fire Extinguishment. The effectiveness of dry chemical powders for control of fires is under investigation for the Bureau of

Ships. In one phase of this study, the minimum rate of powder application

required to extinguish flammable liquid fires ranging in size from about

1 in. to 22 in. in diameter was determined. It has also been found that

considerable confidence can be placed on the use of very small experimental fires to measure the extinguishing efficacy of dry powder agents.

Surface Flammability of Materials. The ease with which the interior

finish of a building ignites and burns is an important factor with respect

to the fire safety of occupants of the building. Building and code officials

specify limits on the finish flammability depending on type of building

occupancy expected.

Since announcement of the development of the radiant panel flame spread

test method at the Bureau, a large number of industrial research laboratories

have installed test equipment of this type. To insure uniformity of test

results being obtained with use of the test equipment, an interlaboratory

study showed that excellent reproducibility could be achieved, with apparatus developed at the Bureau, provided slight modifications were made in the

recommended calibration technique. These changes have been incorporated

in the recently completed Interim Federal Standard No. 136 which was

prepared at the request of several governmental agencies.

Standards for Refrigerated Trailers. A study of methods for circulating the chilled air inside refrigerated trailers is now underway for the

U.S. Department of Agriculture to supplement the equipment rating program

adopted last year. Current experience indicates that all parts of the frozen

89
food cargo are not now being adequately protected in many cases because

of lack of technical information on the air distribution required inside the

vehicle.

Underground Pipe Insulation. The Bureau is carrying on a continuing program for developing technical data on underground pipe insulating

methods for the Army Corps of Engineers, the Navy Bureau of Yards and

Docks, and the U.S. Air Force. The results of these studies so far have

been used to modify the criteria for underground pipe insulating systems

now used throughout the Federal Government and as a guide in preparing

a performance specification for all materials designed for such applications.

Asphalt Studies. In cooperation with the Department of Defense, ex- tensive laboratory and field studies were made to determine the practicability

in service of self-sealing asphalt shingles made available recently by several

manufacturers. The time of sealing at various temperatures, the temperatures of the shingles exposed on roofs, and the resistance of the shingles to

winds up to 60 miles per hour were determined. Field studies were made

in both northern and southern locations to provide a variety of climatic

conditions. From the data obtained in the laboratory and field studies,

suggested criteria for the performance of self-seal shingles have been

furnished to the sponsors.

Investigations of the mechanism of degradation of asphalt and its products was continued. The effects of chemical additives on asphalt durability, infrared spectral properties, and the absorption properties of

asphaltenes were studied. The stable free radicals in asphalt were investigated with electron spin and resonance techniques, and the oxidative changes

occurring during accelerated weathering tests were analyzed by chemical

methods.

Wear Resistance of Flooring Materials. The compositions and constructions of floor covering materials have undergone considerable change

in the past several years, thereby creating a need for reliable methods for

evaluating the resistance to wear of the newer materials on which there

is little field experience. The Bureau has been cooperating with several

European laboratories in tests of a series of such representative materials

as vinyl plastics, rubber, and asphalt. Specimens have been exposed to

actual wear tests in a Paris subway, in elevators in Berlin and Stuttgart, and

in buildings at the Bureau in Washington. Results to date show little

correlation between actual wear in service and laboratory tests with abrasion

machines.

Lightning Hazards of Buildings. The use of metallic siding and roofing for buildings and metallic reflective insulation in buildings has raised

a question as to whether these materials, if not properly installed, increase the

probability of fires resulting from lightning discharges. Using these metallic materials with sections of typical frame buildings, the Bureau has demonstrated by laboratory tests that flammable materials could be ignited by

high voltage discharges when the metallic materials were not grounded.

Similar results were obtained with ungrounded prefabricated metal chimneys.

90
The effectiveness of dry powders in extinguishing fires of flammable liquids

was studied (page 89).

Safety Codes. A revision of the American Standard Safety Code for

Head, Eye, and Respiration Protection, sponsored jointly by the Navy

Department, the Bureau of Mines, and NBS, was completed. The revision

discusses the use of transparent plastics in goggles and face shields and

includes many new performance requirements.

The Code for Protection Against Lightning, sponsored jointly by the National Fire Protection Association, the American Institute of Electrical

Engineers, and the Bureau, was revised. The revision includes additional

details on the protection of tanks containing flammable liquids.

2.11. Applied Mathematics

The Bureau maintains a central applied mathematics facility which conducts basic and applied research and renders advisory services to other

government agencies in various mathematical fields. Equipped with modern

computing aids, including high-speed digital computers, the facility plays a

significant supporting role in the Bureau's research and development program. The work covers a wide range of investigations and applications in

engineering and the physical sciences. In addition, an increasing share of

the Bureau's mathematical effort is devoted to applying digital computers

to problems of the type encountered in business management and operation,

sometimes referred to as "data processing" problems. The facility also

provides consultation on the statistical design and interpretation of

experiments.

531788 O—60 7 91
A vigorous research program is directed toward creating and improving

mathematical methods for science, engineering, and management. It is

concentrated in three main areas: The program in numerical analysis is

aimed at developing methods of computation with special emphasis on the

use of modern high-speed equipment; studies in classical applied mathematics are devoted to the analytical, rather than the numerical treatment

of physical problems; and research on mathematical statistics is concerned

with the design and interpretation of experiments, and with reliability and

life testing of equipment.

Numerical Analysis. Research in mathematical topics applicable to

numerical analysis was conducted with the support of the Office of Naval

Research. Such research is of vital importance in its contribution to the

effective application of modern digital computing equipment. Topics cov- ered included incidence matrices, modular functions, groups and subgroups,

and the convergence of iterative procedures for the computation of characteristic roots and vectors.

Training Program. The second program in Numerical Analysis,

sponsored jointly by the National Bureau of Standards and the National

Science Foundation, was held at the Bureau during the spring of 1959.

Intensive training in numerical analysis was given to nine university teachers

who are experts in related mathematical fields. This concentrated study will

provide the background which will allow them to teach and conduct research

in numerical analysis and to direct university computer centers. The national shortage of mathematicians competent in programing for high-speed

automatic digital computers and in carrying out the required numerical

analysis motivated the presentation of this course. The program was divided into three parts: (1) Lectures on coding and

programing for electronic digital computers; (2) lectures on theoretical and

practical topics in numerical analysis; and, (3) and a problem assignment

in which each participant prepared a major code, ran the code on the machine, and interpreted the results.

New Eigenvalue Method. The eigenvalues and eigenvectors of a matrix

are necessary to the solution of such a wide variety of problems that computation laboratories must have available a selection of methods and codes for

computing these functions. A new method for computing dominant eigenvalues was coded and tested by the Bureau. This method can be applied

to matrices with nonnegative elements or to those which can be put into this

form by certain simple transformations. In addition it is iterative and can

be carried out with extremely simple arithmetic operations. Applied to a matrix poorly conditioned for many matrix operations, the method yielded

the answer to 5 places after 63 iterations.

Stability of Recurrence Relations. Recurrence relations are commonly employed in computing because they are convenient to formulate

and easy to code for electronic computers. Numerical analysts therefore

look for these relationships and utilize them whenever they can. However,

despite their many attractive features, recurrence relationships possess a 92
property which may cause difficulty. Unless care is taken, they may allow

so much roundoff error to accumulate that the results of the computation

may be invalidated. This phenomenon is known as "instability."

A study has been made of the roundoff accumulated when systems of first

order recurrence relations are used. It has been known for some time that

the stability of a system is not independent of the direction in which the

recurrence is carried out. Sometimes a computation which shows instability

for increasing parameter values will be perfectly stable for decreasing values.

By making use of such facts, the Bureau developed criteria for the direction

of computation. The criteria were applied to the calculation of the incomplete gamma functions, which occur in various molecular computations.

Machine Translation. Machine translation provides a new approach

to producing English text from Russian technical literature. A translation

scheme presently being studied by the Bureau for the Army Office of Ordnance Research instructs an electronic computer to rearrange and weld together English correspondents of Russian words to make a meaningful

reproduction of the intent of the original. Initial simulation on a highspeed electronic computer indicates the practical applicability of this scheme.

The program first instructs the machine to transform the words of a Russian sentence into a highly condensed representation for matching in a glossary. The machine is then told to recognize the syntactical relation

between the words. After this, it puts together the corresponding English

words into a meaningful sentence. With the improvements and shortcuts

that will be developed in the programing and by using the advanced computers under construction, it is estimated that the cost will be about the

same as for a human translator.

Mathematical Tables. Considerable progress has been made with the

Handbook of Mathematical Functions, which the Bureau, with the support

of the National Science Foundation, is compiling. Of 29 projected chapters, 20 have been finished and circulated to an advisory committee and 5

others are being edited prior to circulation. Accompanying tabular material has been prepared on an automatic card-operated typewriter for

photo-offset reproduction.

A volume of Tables of Osculatory Interpolation Coefficients and one of

Integrals of Airy Functions were published. Three volumes of tables are

now in press. These are: Sievert's Integral, Coulomb Wave Functions of

Order Zero, and the Bivariate Normal Distribution Function.

Improvement in Facilities. During the past year the capacity of the

electronic computing installation was greatly increased by expanding the

high-speed memory to 32,000 words and adding an auxiliary magnetic-drum

memory. The machine was placed on three-shift operation. In addition

to performing computations arising in the work of the Bureau, it serves as a standby facility for the Weather Bureau, carries the main computing load

of the National Aeronautics and Space Administration's Theoretical Division, and serves numerous other Federal agencies.

93
Experiments in machine translation indicated a promising approach to practical production of English text from Russian technical literature (page 93).

Digital Computation, Several standardized computer programs of a general nature are available for use within the Bureau and in other Federal

agencies. These programs can be applied to curve fitting by the method

of least squares, to solving systems of linear equations, to determining

eigenvalues and eigenvectors, and to regression and Fourier analysis.

Many older programs were revised in order to take advantage of the greater

machine memory. For instance, in the problem of interpreting X-ray diffraction patterns for crystal structure analysis, the computing time has been

cut in half. A general-purpose orthonormalizing code was revised not only

to gain time but also to give a more detailed output. Computers were also

applied to various problems arising in scientific fields. Some of the calculations made were the determination of gas tube characteristics, intensity

functions and cross sections for scattering of light from spherical particles,

absorption spectra of ferrides, and microwave absorption by large molecules.

In the data-processing field, important problems included bid evaluation,

allocation of radiofrequencies, simulation of postal operations in connection

with the Bureau's study of post office mechanization, and simulation of

military engagements. In a new venture, the electronic computer was used

to produce wiring diagrams automatically for the design of the Bureau's

new Pilot computer.

In preparation for the addition of an off-line printer to the computation

facilities, programs were developed for the automatic plotting of curves and

for the automatic large-scale dumping of data onto magnetic tape.

94
Design of Experiments, New mathematical methods were developed

for selecting subsets of treatment combinations in multifactor experiments.

This has made it possible to extend designs for experiments, formerly limited

to those involving factors at just two or just three levels, to those involving

a mixture of two and three levels. Until now no theory for the construction

of fractional factorials of the mixed series has existed, i.e., for designs

involving m factors each at two levels and n factors each at three levels.

Formerly, experiments involving the simultaneous variation of a number

of background factors had to be interpreted by running tests at all possible

combinations of a fixed number of levels for each of the several factors

under study. This method required a number of measurements often prohibitively large. In addition, it was often not practical to plan an entire

experimental program in advance. Fractional factorial designs are a means

for overcoming these disadvantages and their use has become common in

recent years because of the availability of plans for the 2m and 3

n series.

This latest work under the sponsorship of the Bureau of Ships has led to a catalog of designs to the mixed series as a sequel to the catalogs previously

prepared for the 2W series and the 3

n series.

Life Testing and Reliability. Research on methods for the analysis of

data from life-testing experiments has led to the development of exact

methods to replace the currently used approximate methods. In life-test

experiments a number of nominally identical items (tubes, lamps, and electronic components, for example) are run under a given set of operating

conditions and the time to failure recorded for each item. The analysis of

data from such tests when a spectrum of operating conditions is employed

has previously been handled by methods worked out for other situations.

These give only approximate results for the distributions encountered in

life-testing phenomena. The new procedures provide criteria for extrapolating the results of accelerated environment tests to provide estimates of

performance under normal operating conditions.

The study of life-testing procedures is part of the program of research on

measurement and prediction of the "reliability" of complex systems. Another aspect of this program has been the study of mathematical models for

representing the dependence of system performance on system design and

component properties.

Interlaboratory Comparisons. A simple way to analyze the discrepancies between different testing laboratories presumably employing the same

test procedures was recently worked out. The method makes use of a graphical presentation of the test data which allows each laboratory to tell at a glance how its performance compares with that of others. The graph can

point the way to corrective action to eliminate the bias, if any, in the technique used by a particular laboratory; or it may indicate the need for an

improved test procedure—one that lends itself better to uniform application

by all laboratories. A method for analysis has been worked out to provide

numerical estimates of the parameters of the test procedures including an

estimate of the precision of the test procedure. This procedure has been

95
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successfully used in intercomparing the results of industrial, State, and Government laboratories for tests of paint, soap, and other materials such as paper (see sec. 2.7, p. 65)

.

Statistical Services. Statistical services were rendered to the U.S.

Geological Survey on the formulation of a mathematical model for the analysis of hydrologic data. For the Veterans' Administration, the Naval Ordnance Laboratory, and other laboratories, a number of large-scale analyses

of data were programed and run on the Bureau's computer. Typical of

the computing service provided for other sections of the Bureau is the program prepared for the machine computation of data from mechanical and

interferometric measurements of gage blocks. A statistical analysis to provide data on the precision of the measurements and internal checks to assure

the absence of systematic errors was also carried out.

Mathematical Physics, To aid in the formulation of mathematical

theories basic to the development of theoretical physics and engineering

science, the Bureau, with the support of the Office of Scientific Research,

USAF, conducts a program devoted to problems of this type. Studies during the past year included an analysis of the important problem of the

96
mechanics of turbulent diffusion by the techniques of statistical mechanics,

and analysis of the outflow from a breached dam for the Army Map Service.

A statistical approach was also applied in studying the kinetic equation for

a plasma. A survey and outline of problems in plasma dynamics and magnetohydrodynamics form the basis for planning expanded research in these

fields.

Other work included a determination of the fluctuations in the annual

flows and runoffs of rivers, investigations of the behavior of the solutions

of the first-order nonlinear Poincare equation and the second-order nonlinear Rayleigh equation, a study of thermodynamics and hydrodynamics of

two-phase flows, and a promising theoretical investigation of satellite motion.

2.12. Data-Processing Systems

The Bureau's program in data-processing systems includes research, development, systems design and analysis, and technical advisory services in

both digital and analog computer technology. The Bureau serves the Government as a central agency for providing comprehensive and readily available information in both the development and application of high-speed

automatic data-processing systems. As a result, a great number of requests

are received from other government agencies for assistance and advice relative to their data-processing problems in engineering, management, and operations research, as well as control systems and simulation. These advisory

activities strengthen the Bureau's basic computer program, which ranges

from research in components, circuits, systems, and simulation to advanced

work in new computer applications.

Among the accomplishments in this area during the past year were basic

and applied research on components and circuits for use in analog and

digital data-processing devices and systems, advancement of the theoretical

formulation of basic principles and logical techniques for designing largescale systems, and special studies of the application of such systems to government problems. In cooperation with the National Science Foundation,

an information center and advisory service on research and development in

the field of information processing and retrieval was established.

SEAC and Analog Computing Facilities. SEAC has continued to be

used as the Bureau's high-speed digital research facility. It assisted in

investigations of simulation techniques, patent search trials, picture processing, pattern recognition, and data format conversion. In some instances,

processing these problems resulted in modifications that improved the utility

of the machine. For example, the input-output system was modified to

accept a 36-bit word as well as the usual 45-bit word so that data recorded

on the magnetic tape units of a commercial computer could be read into

SEAC and then read out on a display oscilloscope or on an analog plotter.

A new input-output order was also incorporated so that any number of

words, from 1 to 2,048, may be read into or printed out from the memory

with a single command.

97
The problem-solving capability of the Bureau's analog computer was

extended by incorporation of an additional three-product multiplier unit

and a servo resolver. A point-plot system was added to the 30 by 30 in.

X-Y plotter, and a set of 0.1 percent resistors and capacitors were procured

to permit more precise calibration of operations.

The Bureau's simulation facility, which includes use of both SEAC and the

analog computer, was used to simulate automatic intercept vectoring systems

and proposed methods for control of takeoff and landing traffic at the

Washington National Airport.

Initial surveys of laboratory operations throughout the Bureau led to the

identification of at least 50 areas in which the recording and processing of

experimental data could be automated. Typical problems encountered include atomic scatter, electron resonance, thermodynamic theory, surge

voltage, transistor circuitry, Fourier analysis, X-ray spectra of alloys, lens

image patterns, transistor aging tests, Civil Service Board records, spectral

reflectance of glasses, Calibration of thermocouples, and weighing techniques.

Continuing consultation and assistance on procedures for collecting, converting and transmitting data for automatic high-speed computation also

resulted in the design of several pieces of special data-logging equipment.

PILOT Data Processor, Because of the anticipated variety of potential

applications, the new NBS Pilot Data Processing System has been designed

to incorporate into a single installation such characteristics as high datahandling rate, flexibility of communication with external devices, and a wide repertoire of internal processing operations. During the past year,

the logical plans for the entire PILOT system were transcribed into a form

suitable for processing on a high-speed computer to convert them into wiring

tables describing the point-to-point electrical interconnections. The input

data, punched on more than 20,000 cards, were subjected to detailed checking and processing, using the computer programs developed as part of the

digital systems research program to produce the required tables.

The physical structure of the central part of PILOT is nearing completion.

The rapid-access diode-capacitor primary and secondary memory units have

been completed except for a full complement of storage elements. The

central computing and control units of PILOT, including the diode-capacitor

memories, will contain more than 6,100 vacuum tubes and 193,000 diodes.

Components and Techniques. Basic research in the development of

new computer components through the novel Use of materials and physical

phenomena is expected to result in greatly improved computer performance

in the "next generation" of data-processing equipment. Because there is

an immediate need for large random-access memories with read-write cycles

of less than 1 microsecond, an investigation was made for the Department

of the Army of thin ferromagnetic films as basic storage elements. Special

equipment was obtained for better control of the characteristics of the ex- perimental films, and a hysteresis loop tracing oscilloscope was designed

and constructed. Studies are in progress on evaporation techniques for

producing multilayer devices.

98
Left: Analog-digital simulator used to study air traffic problems. An airways

map of the Washington, D.C., airport appears on the screen. Right: Prototype high-speed document retrieval device handles microfilm at the rate of

2,400 pages of documents per minute (pages 98, 100).

Progress in circuit techniques was made by developing a set of seven

compatible transistor switching circuits in a program sponsored by the

Department of Defense. These circuits can be utilized as building blocks

in assembling various data preparation and recording systems for input

to large-scale digital data-processing systems. The design of these circuits

was greatly facilitated by deriving the equivalent circuit that directly characterizes a transistor in such a way that its performance in a switching

circuit can be accurately predicted either by digital computation or by

analog simulation. It differs from previous equivalent circuits primarily

by representing the input impedance as well as the transfer ratio even in

the condition of saturation.

Cloud Height Data Analyzer, A special application of these transistorized circuits was made for the U.S. Weather Bureau in the redesign of

the rotating beam ceilometer. The new circuit design utilizes these transistorized logical building blocks to perform the automatic control and preparation of weather data for transmission. A prototype of the equipment was

provided for evaluation of both the new technique and component reliability

for future use at the Weather Bureau's automatic (unattended) weather

stations.

Digital Circuitry. The transistor-magnetic core circuitry designed to

perform the logical and switching functions of the central part of a highspeed digital computer was subjected to a thorough theoretical analysis in a

program sponsored by the Department of the Army. The gain, stability,

and volt-second transfer function of a single stage have been determined.

A successful method for connecting such synchronous circuits to asynchronous magnetic tape recording units and pulse generators was also achieved.

99
Document Retrieval Device, The rapid selector, developed for the

Navy Bureau of Ships and the Patent Office, is a machine that rapidly

retrieves information from massive files or documents that have been

recorded on 35-mm film. The logic and control circuits have now been

completely transistorized and the film transport and optical system have

been improved. A new film transport, now being designed, is expected to

increase the film speed to 20 feet per second to improve the handling of the

master film, and to simplify the overall operation.

Packaged Computer Circuitry, Standardized basic building blocks

in the form of plug-in packages with which complex digital computing and

control circuits can be assembled were developed under the sponsorship of

Air Force Cambridge Research Laboratory. In addition to the two central

computer types (regenerative pulse amplifier, diode gate, neon indicator

driver, and switch signal filter boards) , several special-purpose packages

necessary for a complete digital system were designed, tested and converted

to finished printed circuit form: A master clock oscillator, a constant amplitude clock driver, a transistorized plugboard driver and a plugboard mixer.

An assembly of more than 200 interconnected packages was tested for operational margins, crosstalk, ground noise, and filtering. The effectiveness of

twisted pairs and of a good ground plane was demonstrated. Dynamic and

static package testers were also designed and developed.

Digital Systems Research, A new way of using incidence matrix techniques for analyzing complex logical problems was discovered in an investigation for the National Science Foundation. These problems are encountered when groups of concurrently operating computers, or other

automatic devices, are harnessed together to form an intercommunicating

network. In such a network, keeping the separate programs on the

various computers efficiently in step with each other is important. Special

techniques are needed for analyzing the complex priority relationships between related steps in the individual programs. Using incidence matrix

techniques, new methods have been found for automatically detecting and

correcting possible conflicts in priority between the different machines and

for deriving optimal sequencing schemes in writing programs for them.

Flight-Maneuver Data Processing. A joint U.S. Air Force-NavyNational Aeronautics and Space Administration program has been set up

to consider establishing a data-processing facility capable of processing a minimum of 30,000 flight-hours each year of maneuver-loads data from aircraft. Accelerations, velocities, and other parameters are to be analyzed

to determine the effects of maneuvers on structural loading of aircraft.

Under the sponsorship of the Navy Bureau of Aeronautics, the Bureau studied

the computing techniques and equipment that would be required for such a

facility. Several possible operating systems, varying from all-digital to

combined analog-digital processing, with several variations dependent on the

degree of automation, were proposed for consideration. Since for any

facility a high-speed digital computer is required, capabilities of various

100
available computers were studied and sample computations programed to

estimate computing speeds.

Automatic Processing of Electrocardiograph Data. At the request

of the Veterans' Administration, a prototype research device that uses automatic data-processing techniques to handle electrocardiograph data was developed. This equipment accepts data about the electrical activity of the

heart from analog magnetic tape, converts it into numerical information,

and then rerecords it onto digital magnetic tape for input to a high-speed

computer for final processing. An experimental computer program was

written to test the feasibility of the complete computer data handling procedure before the full-scale processing task began.

Automatic Mail-Sorting Developments. The Bureau is continuing

to assist the Post Office Department's Research and Development Division in

its objective of applying automatic equipment and data-handling techniques

to the improvement of the mail-handling operation. A detailed analysis of

various configurations of automatic sorting machinery was undertaken to

relate such parameters as mail input and output rates, sorting rates, destination handling capacities and cost per unit. Incoming and outgoing distributions of mail at several large city post offices were studied and analyzed,

and system studies were made to evaluate methods for the three basic kinds

of sorting—outgoing, incoming, and carrier-walk. Several studies were also

made concerning the requirements for a memory system or an electronic

directory for use with sorting equipment.

101
Computer Data Editing and Reporting, The U.S. Public Housing

Authority must constantly review a tremendous volume of reports of eligibility for continued occupancy of low-rent housing. The Bureau has been

studying the possibility that the analysis of this data can be automated. As

a result, computer programs that edit the data automatically, compile statistical tables, and generate form letters were developed for preliminary

trials. Query data were processed and machine-prepared letters were composed by the computer program and run off on the output printer. Similar

edit, report generation and statistical analysis routines for the housing applications reports are now planned by the PHA.

Mechanization of Patent Searching, Progress has been made in a cooperative program with the Patent Office for the mechanization of patent

search operations. A comprehensive machine-search procedure, for examining patents on the chemical arts, was revised and expanded to include such

complex operations as specific and generic searching as well as "negative

statement" searching. The program makes use of a multiplicity of mutually

exclusive search paths, the principal ones of which have been tested on SEAC

by using samples of question and disclosure data.

Studies were carried out on the feasibility of searching English-language

texts by machine for specific information and on artificial dialects of increasing sophistication for use in retrieval experiments. A program was

written for processing and analyzing pictures, and boundary tracing schemes

were investigated.

Research Information Center, Since the activation of the Research

Information Center and Advisory Service on Information Processing, under

the sponsorship of the National Science Foundation, major emphasis has

been on collecting and organizing literature pertinent to the field and formulating a comprehensive bibliography covering a wide range of interests in

information storage, selection, and retrieval. A field glossary, consisting of

defined terms selected from the vocabularies of the various allied disciplines,

is being tabulated; lists of research workers in the field are being compiled;

and a study of the related basic research areas is in progress to determine

which techniques seem likely to be applicable to the solution of problems in

the field.

Additional Data-Processing Applications, The monthly reports

of the Federal Home Loan Bank Board serve as one index of the status of

the Nation's economy. Assistance was requested in analyzing the Board's

operations and for a feasibility study on the applicability of automatic dataprocessing techniques to speed up the preparation of the reports and minimize delays in subsequent actions. Initially, methods to test consistency

of the input data and to estimate substitution data were undertaken. Processing of actual data to produce the required reports was subsequently

demonstrated.

At the request of the Federal Communications Commission, a preliminary

study of the possibility of speeding up the flow of information for management decision making was undertaken. The task was to identify those areas

102
An analog-to-digital converter was developed for changing heartbeat data to a form suitable for use in a high-speed computer. Inset: A technician selects a suitable cardiac complex by monitoring signals on oscilloscope (page 101).

of their activities where automatic data processing techniques would be

applied. A joint cooperative program to study the data-flow pattern and

the procedural activity of each functional area was then undertaken to establish the basic requirements of a data-processing system.

At the request of the General Services Administration, assistance was provided in the evaluation of proposals for an automatic data-processing system

to integrate control over the Federal Supply Services network of stores

depots.

A program for personnel data recording and reporting, requiring the development of file maintenance routines that can be used for generalized

updating of "personality type" files, has been inaugurated, and preliminary

computing machine routines have been programed. As a first example of a

report generation program, sample personnel records of NBS have been

selected, encoded, and converted to tape. The major part of the coding for

the generation of the Bureau's portion of Monthly Report of Federal Civilian

Employment has been completed.

2.13. Cryogenic Engineering

The Bureau's cryogenic engineering activities, centralized at the Boulder

Laboratories, are designed to provide information on the behavior of systems

at very low temperatures. Both Government and industry are faced with

problems in this rapidly growing, specialized field. One difficulty encountered is the critical nature that the properties of materials sometimes assume

at low temperatures. To solve this problem, the Bureau provides basic materials data at cryogenic temperatures as one of its main activities. Equally

important are other Bureau research programs concentrated on insulating

techniques, liquid flow, and instrumentation.

103
Rendering advisory services to both industry and other government agencies is another intrinsic part of the Bureau's efforts to help establish the field

of cryogenic engineering. The demand for such help has greatly increased

as a result of accelerated programs dealing with long-range missiles and

space vehicles which rely on cryogenic liquids as propellants.

Low-Temperature Properties of Materials. Property measurements at low temperatures are usually made to determine the suitability of a

material for a specific application. Another area where properties and the

effects of temperature are important is the field of thermometry where thermocouples are often subject to errors due to heat conduction. To help improve

temperature measurements, the Bureau measured to 4° K the thermal conductivity of a gold-cobalt alloy that is widely used in low-temperature thermocouples. The present results permit users to estimate the extent of the errors

introduced.

Data to be directly applied in cryogenic engineering were obtained on the

strength and thermal efficiency of 5086 aluminum alloy. Results confirm

that this alloy can be successfully used in welded structures at very low

temperatures. Other investigations were made on organic adhesives, important where welding and soldering are ruled out by the nature of the

application or the materials to be bonded. Ten organic adhesives were

studied down to 20° K for the Wright Air Development Center. The adherend was aluminum or stainless steel. High strengths independent of

temperature were obtained with an epoxy-phenolic adhesive supported on

glass cloth. A filled epoxy also behaved well in conformance with earlier

work.

The temperature conditions under which martensite can form in 300 series

stainless steels were studied. Types 303 and 304 were found to be strongly

transformed. This transformation is promoted by thermal cycling to low

temperatures. A sample of type 304 continued to transform slowly after

nearly a year of daily cycling between ambient and 76° K. The effect of

this transformation on strength will be determined. Although the martensite

phase is known to be very brittle, preliminary results indicate that partially

transformed 304 retains substantial toughness.

Insulation. The most striking development of the past year was the

discovery of new evacuated laminates that give tenfold improvement in insulating value over the best evacuated powders. An effective mean thermal

conductivity of 0.5 microwatt/cm-deg K between boundary temperatures of

ambient and 20° K has been attained. The laminates consist of alternate

layers of aluminum foil and thin glass-fiber batt or paper. Development of

practical insulating schemes based on these laminates will permit revolutionary simplification and compactness of large vessels for liquid hydrogen

or helium.

The use of uninsulated equipment for the transfer of liquid hydrogen was

shown to be desirable for high-flow-rate applications. The heat transfer to,

and the pressure drop in, such systems were measured. The Bureau also

demonstrated that the use of condensing-type vacuum insulation in equip104
Studies of the behavior of liquid oxygen (boiling in large tank at right) provide information needed for the design and launching of large rockets which

use liquid oxygen as a propellant. Left: Distillation column used in the separation of hydrogen isotopes. The distillation technique promises to make

possible economical large-scale production techniques for obtaining deuterium

(pages 106, 104).

ment which is to have the vacuum space sealed off provides insurance against

the disastrous effects of small leaks. This desirable effect stems from the

sorbtive capacity of solid C02 for H2 gas.

Liquefied Gas Flow. Basic information on the transfer of liquefied

gases is essential to the design of piping systems for two-phase fluid flows.

The Bureau therefore investigated the adiabatic and highly diabatic flows

of fluorotrichloromethane (CC1 3 F commonly known as Refrigerent F-ll)

and hydrogen. The results indicate the Lockhart and Martinelli correlation, with a simple momentum correction, can be used to predict the pressure

drop in two-phase, single-component fluid flow.

Venturis, orifices, and turbine-type meters all proved to be reliable in

measuring the flow of liquid hydrogen. Accuracies of better than 1 percent

were obtained.

Cryogenic Equipment. An air-transportable, 50-gal liquid-oxygen,

aircraft-servicing Dewar, designed by the Bureau for the Wright Air Development Center, was completed. The steady state heat leak is only one-fifth

that present in currently used equipment. The major sources of heat leak

supports and piping—in other equipment cause only negligible heat leak in

the optimized container. Innovations such as synthetic-fiber webbing supports and utilization of the load-bearing properties of insulating powders

were found practical.

Assistance to the University of California's Lawrence Radiation Laboratory on the cryogenic engineering of liquid hydrogen bubble chambers was

105
continued under the sponsorship of the Atomic Energy Commission. Efforts

were highlighted this past year by the successful operation of a chamber 72

inches long containing about 550 liters of liquid. The hydrogen refrigeration system designed by the Bureau provided continuous refrigeration and

the necessary automatic temperature control of the chamber liquid.

Activities in the cryogenic engineering of bubble chamber and associated

refrigeration systems have led to many requests for advice on design details.

As part of the resulting program of assistance, the Bureau will cooperate with

the British National Bubble Chamber group in designing cryogenic systems

next year.

Ortho-Para Conversion of Hydrogen. An important research program covering all aspects of the conversion of hydrogen from the ortho to

the para form was brought to a successful conclusion during the past year.

The primary objective of the work was the development of catalysts for

promoting the ortho to para reaction. The development of a highly effective catalyst which makes possible the manufacture of stable liquid parahydrogen rather than the unstable liquid normal hydrogen has resulted in a

substantial reduction in storage equipment costs.

Processes, such as film and pore diffusion, which determine the kinetics

of the reaction, have been studied. Progress was made in determining the

controlling step in the reaction rate. In addition to the kinetics work, a

study was made of activation procedure.

Hydrogen Distillation. Cryogenic distillation of hydrogen has long

been recognized as an excellent method for deuterium recovery. Because

of the wide uses predicted for deuterium and heavy water, economical largescale production techniques for obtaining this isotope are in demand.

Unloading liquid helium flown 1,700 miles from Denver to Washington. Over

90 air trips have been made to supply the Bureau's Washington laboratories

with helium liquefied at the Boulder (Colo.) Laboratories (page 108).

106
Low-temperature data on the compression deformation of indium were obtained prior to its use to seal the massive glass window of the 72-inch liquid

hydrogen bubble chamber for the University of California (page 105).

A program of studies on deuterium separation included the operation and

evaluation of a hydrogen distillation pilot plant. Parameters such as plate

efficiency, plate geometry, pressure drop, and heat transfer were considered

and the data obtained are expected to provide a sound basis for the design

of full scale industrial plants.

Cryogenic Engineering Data. The Cryogenic Data Center, established last year, has indexed several thousand listings of published articles

and reprints, useful in the cryogenic engineering field. Bibliography service is being furnished the NBS staff on request, and reports or photocopies

of material are procured when needed. Plans are being formulated to

extend this reference service to the cryogenic engineering industry as a whole.

Another activity of the Cryogenic Data Center is the compilation of the

thermophysical properties of cryogenic materials and the assembling of data

sheets, references, and other pertinent material, into an expandable compendium. This project, sponsored by the Wright Air Development Center,

started last year and is expected to be completed early in 1960.

A book by a member of the cryogenic engineering staff ("Cryogenic

Engineering", by R. B. Scott, D. Van Nostrand Co., 1959) makes readily

available to engineers and other research workers the specialized techniques

of cryogenics as well as a considerable amount of frequently used data.

Helium Properties. Thermodynamic properties of helium in the compressed-liquid region were obtained from all known sources and assembled

into several properties charts. Some very recent data in the compressed

531788 O—60 8 107
liquid region were examined and correlated with earlier data. The resulting

correlations were believed to represent the best information currently available and should prove extremely valuable to the cryogenic design engineer.

Gas Liquefaction, Production of liquefied gases this year continued

to increase. Approximately 280,000 liters of liquid parahydrogen (a 30-

percent increase over last year), and over 1,200,000 liters of liquid nitrogen

were produced. Recovery of evaporated hydrogen gas from liquid storage

and tests netted over 5 million cubic feet for reliquefaction.

The production of liquid helium this year nearly doubled that of last year.

Forty-eight hundred liters were produced and almost half was shipped by air

to the NBS Washington Laboratories, mostly for use in the Free Radicals

Research Program (see sec. 2.3). The helium liquefier which had been

installed as an integral part of the hydrogen liquefier system was revamped

and made independent of the hydrogen plant so that it could be operated

simultaneously.

2.14. Radio Propagation

The Central Radio Propagation Laboratory has the primary responsibility

within the U.S. Government for collecting, analyzing, and disseminating information on the propagation of radio waves at all frequencies along the

surface of the earth, through the atmosphere, and in outer space. To carry

out its responsibility, this Laboratory conducts research on the nature of

radio waves and the media through which they are transmitted, the interaction of the waves with the media, and the nature of radio noise and interference effects. A network of field stations is operated from the Arctic

to the tropics, and data are exchanged with other laboratories throughout

the world. The work of the Laboratory is divided into three areas: radio

propagation physics, radio propagation engineering, and radio communications and systems.

Radio Propagation Physics

The radio propagation physics program is directed toward a better understanding of the interaction of radio waves with ionized media, such as the

earth's ionosphere and interplanetary space, and the practical problems of

communication via these media. To achieve these objectives, the program

includes: (1) Basic research on the composition, physical processes, and

structure of the upper atmosphere and interplanetary space, on the formation

and variation of the ionized state of these regions, and on the interaction

of radio waves with the ionization; (2) study of the reflection, refraction,

scattering, and guided-mode mechanisms by which radio waves are propagated through the ionosphere and interplanetary space; and (3) regular

public service by predicting long-term changes in useful frequencies for

communication, the short-term warning of disturbances to communication,

and by collecting and distributing ionospheric and solar data on a naticnal

and international basis.

108
Electron Density Measured Directly. Radio propagation parameters, useful in communication applications, come directly and fairly accurately from measurements of echo heights by soundings with 1- to 25-Mc

radio-wave pulses. However, the production, depletion, and dynamics of the

ionospheric layers can be understood only if the electron density is known

at each height. In addition, with scientific and technological interest in

space, it is important to learn more about the ionosphere above the level of

peak ionization of the F-region, the limit of conventional radio probings.

The Bureau's experiments with scatter radar have shown that, for the

first time, direct measurements can be made of electron density throughout

the ionosphere. Also, the Bureau's computing facilities were used for the

first large quantity calculation of electron density profiles from conventional

ionospheric soundings. On the basis of theoretical work, these profiles have

been extrapolated above the peak density of the F-region to 1,000 km or

more.

Electron Densities Measured to 750 Kilometers. Radio waves are

very strongly reflected from the ionosphere when they meet electrons having

a plasma frequency equal to the frequency of the probing radio wave. Radio waves of higher frequencies penetrate outer spa^e, but a minute fraction

of this energy is scattered by free electrons. W. E. Gordon of Cornell re- cently showed that this extremely weak scattered energy should be proportional to the electron density at the place the scattering occurs. This prediction was borne out by an experiment performed at a Bureau field station

(Long Branch, 111.).

For the first time a vertical profile was obtained of electron density

through the entire ionosphere by a direct experiment with ground equipment.

The profile extends from the lower ^-region through the peak density of the

F-region and beyond, up to 750 km. It is possible to extend the method to

give improved height resolution and an extended height range of approximately 3,000 km.

In one experiment, a 4-acre broadside antenna was connected with a highpowered 40-Mc pulse transmitter rated at 6 million watts peak power. With

these components and the transmitter unavoidably operating at 10-percent

efficiency, this improvised radar had sufficient sensitivity to detect the incoherent scatter signals. A later experiment gave better detail. The scatter

signal was positively identified, and the Doppler broadening of the returned

echo was found to be much less than predicted by Gordon. The Bureau's

theoretical explanation is that the scattering is from a statistical assembly

of electrons rather than from individual free electrons scattering independently. The scatter radar technique has further possibilities for physical re- search on the ionosphere and exosphere, as well as for application to longrange communications.

True Ionospheric Reflection Heights Recovered. When high-frequency radio waves are used to probe the ionosphere, their group velocity

varies with the electron density along the ray path and according to the

109
earth's magnetic field. Thus the echo heights from conventional ionospheric soundings are virtual heights, and the true heights of reflection can

be recovered only by rather involved calculations.

True reflection heights can now be recovered in quantity by electronic

computer at the Bureau's Boulder Laboratories. However, it is practical to

analyze so completely only a very small fraction of the soundings available.

(The IGY rate was 5 million soundings annually at NBS-associated stations,

15 million annually throughout the world.) Many thousands of profiles

have been calculated for use in ionospheric research and for determining

refraction errors that occur in radio tracking of satellites, space probes, and

other high-altitude vehicles traveling in or above the ionosphere. The Bureau's facilities are also beginning to be used systematically to develop data

on the "climatology" of the ionosphere.

Exosphere Approximated. Except for isolated and limited experiments by scatter radar, whistler, rocket, and satellite techniques, there is

detailed knowledge of the ionosphere only to the height of the peak electron

density of the ^-region, which is 200 to 500 km depending on time, location,

and other factors. The Bureau has computed profiles up to the F-region

peak, and systematically extrapolated these values to exosphere heights ac- cording to a model for the upper F-region which agrees very well with the

Ionospheric section along 75th west meridian, showing plasma frequencies

calculated from ground-based soundings made at NBS-associated field stations.

Contours at greater heights fit a theoretical model of the high ionosphere (page

109).

110
few existing observations. At these levels in the atmosphere, ion production

is negligible and gases are effectively in diffusive equilibrium. From this

work has come an outer ionosphere approximation that can be applied whereever ground-based soundings are made. This approximation is proving

valuable for space applications.

Upper F-region Investigation Planned, The upper F-region will be

investigated by satellite techniques, either directly by probes or indirectly by

radio soundings from above the ionosphere. The Bureau made a scientific

and engineering feasibility study for the National Aeronautics and Space

Administration, as the necessary first step toward topside sounding experiments.

World Maps of the Ionosphere Issued. For measuring ionospheric

characteristics, a network of observing stations is maintained by many

countries. A major objective of this network is the development of an

optimum global representation of the ionosphere for use in long-distance

communications and similar applications. Until such a representation is

available, ionosphere predictions must be made by interim methods.

The Bureau issued 222 world maps that make up the first portion of a semipermanent representation of average propagation characteristics of the

F-region. These maps based on data from the world network give characteristics for alternate hours, Universal Time, and for 6 months sleeted to be

representative of annual variations.

The two principal propagation characteristics are given for sunspot number of 50. World contours of the dependence on sunspot number are also

included. These maps fill a need for basic ionospheric data used in planning

radio communication systems. They probably represent the utilmate in

treating ionospheric data for this purpose (by hand and graphical techniques) for the pre-IGY world network of observing stations.

Ionosphere Mapped by Computer. A solution has been found for

the general problem of making worldwide maps of the ionosphere by use of

numerical analysis and large-scale, high-speed computers. The work has

emphasized the global representation of ionospheric characteristics and their

many variations with time. Problems included in this work have some

similarity to those encountered in synoptic meteorology. Rigorous mathematics are applied to ionospheric data, taking into account their statistical

"noise".

The first part of the problem is a three-dimensional representation of the

data for a given month. Specialized routines are used on a high-speed

computer, and solutions are furnished for a number of applications. In

one routine, a "contour map" (at any desired instant of Universal Time) is

traced automatically on a digital plotting machine making direct use of the

computer output. This method has been applied to 4 months of 1957: March,

June, September, and December; typical of the four seasons. As far as can

be seen, the maps are at least as good as those produced by hand methods,

and are free from subjective errors.

Ill
Further steps are being taken toward a satisfactory method of prediction. Two new dimensions are required to analyze the long-term time

series: seasonal periodicity and- solar activity variations. There are basic

difficulties because the available time series are nonstationary and relatively

short. Therefore, standard statistical methods for time series are not directly

applicable.

Efficient Propagation Mode Discovered in Pacific, In the course

of an IGY project for measuring the difference in the effectiveness of

sporadic—E at 100 km, a propagation mode of comparable efficiency was

found to be active regularly during the evening hours of equinoctial months

for an experimental path in the western Pacific. In September 1958, a special expedition produced evidence that this is an F-region scatter mode, but

that it is many times more efficient than scatter propagation via the F-region

observed in other parts of the world. Early results of these sporadic-^

experiments show that this propagation mode occurs about three times as often on the western Pacific radio path as on a control path in the Caribbean.

Further analyses and experiments will be needed to tell if there is a real

geographic difference in the atmosphere or if unsuspected geomagnetic influences are involved.

Studies of signal fading rates have shown new evidence that sporadic-^

is produced by inhomogeneities in the electron density distribution in the

^-region rather than by a thin horizontal layer having a relatively high

electron density. These studies were based on experimental paths within

the United States.

Airglow and Aurora Origin Questioned. The statistics of radiations

(5577A) from the upper atmosphere observed at Thule, Greenland, were

compared with similar data from low-latitude stations. The results suggest

that the faint aurora and night airglow have a common origin. This is

contrary to the general opinion that these phenomena arise from separate

and distinct physical processes in the upper atmosphere. Another potentially significant result is coming from NBS monochromatic observations of

the aurora made at Fritz Peak and Rapid City during the IGY. Evidence of a distinct auroral fringe was found on the equatorial side of the main auroral

zone. This fringe seems to precede intense auroral activity. Explanation

of this phenomenon would require significant modification of conventional

auroral theory.

Scattering Phenomena in the Equatorial Ionosphere. During an

IGY transequatorial experiment, evidence was produced that a type of spread

echo from the F-region (often observed in the equatorial region by conventional ionospheric soundings) is caused by an intervening thin layer of ionization irregularities. These irregularities were found to be about 15 meters

or less, considerably smaller than suspected. They were shown to be alined

with the earth's magnetic field, an important consideration for their use in

communication systems. Scattering in the equatorial ^-region is confined

to a latitude belt 10 to 12 degrees wide, with stronger effects to the south than

to the north of the magnetic equator. These phenomena are closely related

112
to the electrojet currents flowing in the ionosphere above the magnetic

equator and have promising communication possibilities.

Ionosphere Measured by Satellite Signals. A detailed analysis of

20- and 40-Mc signals (from satellite beacon transmitters) indicated that

the Faraday rotation method can give the electron content of a column of

ionosphere within a few percent. The same analysis showed that there are

large-scale irregularities in electron content amounting to roughly 2 percent

during a single satellite pass. The indicated spatial dimensions of these

irregularities are 100 to 500 km. Observations of satellite signals also give

information on the sharpness of the focusing of radio waves from the

ionosphere at the edge of the skip zone.

Whistlers9 Direction Demonstrated. Atmospheric whistlers are guided along the lines of force of the earth's magnetic field from the point

of the generating lightning discharge outward into the exosphere and back

to earth in the opposite hemisphere, according to present theory. Many

observations at the Bureau and elsewhere have supported the general outlines

of this theory. The first observations of the direction of arrival of whistlers

were made at the Bureau in June 1959, and it was demonstrated that many

whistlers come from discrete directions. The experiment has not progressed

sufficiently to specify the angles.

Data Center Maintained for Ionosphere and Airglow. Under the

IGY program, observational data are collected in World Data Centers to be

generally available for research. According to the international plan there

are three or four duplicate centers for each IGY discipline, located in various

parts of the world. World Data Center A is in the United States and the

subcenter for ionosphere and airglow data is at the NBS Boulder Laboratories. The flow of data is about two-thirds complete, and many millions

of observations are cataloged. An increasing number of scientists from the

United States and abroad are making use of the Data Center. Together with

the Bureau's library of data collected previously, this is probably the fullest

collection of ionospheric and airglow data anywhere in the world.

Radio Propagation. Engineering

More efficient use of the radiofrequency spectrum is the aim of the Bureau's program in radio propagation engineering. This objective requires

a basic understanding of radio-wave propagation, noise, and interference.

To this end, statistical samples of data on radio-wave propagation and radio

noise are collected so that the underlying phenomena may be accurately

described. Methods are developed for using these samples to predict the

statistical characteristics of propagation and noise variables required in

engineering applications.

In general, the program may be divided into four areas of investigation:

tropospheric propogation, VLF propagation, radio noise, and terminal equipment. Substantial progress was made in each of these areas during the year.

113
Radiofrequency Transmission Loss Predictions Improved. The

strength and fading properties of a tropospheric signal are determined by

terrain irregularities, climate, and weather. These properties must be estimated in designing and allocating communication, broadcasting, and navigational facilities.

Until recently, distances beyond the horizon of a radio transmitting

antenna were considered useless for frequencies above 100 Mc. Further

improvements to a formula for predicting the cumulative distribution of

tropospheric transmission loss indicate a possible solution to this problem.

The formula can be used for any combination of terminal height or gain,

for frequencies from 50 to 100,000 Mc, for any geographical location or

terrain profile, and for propagation distances from 0 to 1,000 miles.

A method was developed for determining the transmission loss for very

closely spaced antennas. This method may be useful in assessing the interference between several radio systems operating from a common base.

High-speed electronic computers improve speed and accuracy in the prepara

tion of world-wide ionospheric maps (page 111).

114
Further improvements were made to methods for predicting the tropospheric bending of radio waves in terms of the radio refractive index at the

surface of the earth. These methods are expected to be applicable to improving radar direction finding and to radio missile or satellite guidance systems.

Radio Refractive Index Mapped, World climatological maps of the

surface radio refractive index were prepared. On these maps, climatic re- gions are distinguished by their differences in mean level and by the annual

range of the surface refractive index. Correlation studies were made between

bending, elevation angle error, and the surface value of the radio refractive

index. These studies led to a statistical method for predicting refraction

effects which agrees well (for initial elevation angles of the ray of 1 deg

or more) with predictions based on the CRPL Exponential Reference Atmosphere. However, the prediction method based on the reference atmosphere is recommended for general use because it leads to more accurate

predictions at the lower elevation angles and is at least as good as the

statistical method at all elevation angles.

Refractometers Developed, An improved airborne refractometer

(Model 3) was developed for use in studies of tropospheric turbulence and

radio refractive index. Model 3 has electrical performance much like that

of a previous instrument (Model 2), but it has greater long-term stability.

A transistor power supply and a different microwave configuration have

reduced weight and power requirements. Overall, the instrument is approximately 5x8x12 inches and is intended for use in light aircraft.

A Birnbaum-type microwave refractometer (Model 4) was developed for

Naval Research Laboratory, and was designed for use in a large aircraft.

Model 4 was first used in measurements made in the South Atlantic to

investigate refractive index inversions. Flights were made between Recife,

Brazil, and Ascension Island. The instrument performed very well, and

valuable data were obtained.

A new type refractometer (the Vetter Absolute Microwave Refractometer)

is being developed. The instrument will require very simple circuits, and

will feature improved stability and easier calibration.

Model Range Helps Predict Terrain Effects. Very good predictions of terrain obstacle effects can be made when an obstacle presents a

single knife-edge type of obstruction, giving rise to the phenomenon known

as obstacle gain. When more than one obstacle lies in the path, however,

the prediction process becomes much more difficult.

To resolve some of the effects of multiple knife edges, a laboratory model

propagation path was constructed for transmissions at 20 kMc. Measurements were made on this model range, and the characteristics of knife-edge

propagation were shown extremely well. Clues were found to simplified

methods for predicting the effects of multiple obstacles.

Bistatic Radar Cross Sections Measured. When flying over a propagation path, aircraft often reflect considerable amounts of energy to the

receiving location, thus interfering with more direct paths. During the

115
operation of the Cheyenne Mountain-Haswell propagation paths in Colorado,

this effect was measured while a B-17 aircraft moved through the path.

These measurements indicated the amount of energy that the aircraft reflected

to the receiving site. To analyze this phenomenon completely, it was neces- sary to know the incident energy and the reflecting properties of the aircraft.

This type of reflection is expressed in terms of the bistatic radar cross section

of the aircraft. Measurements were also made in a civilian aircraft flying

over the same flight paths while the transmitter on Cheyenne Mountain was

operating at 1046 Mc.

Attenuation of Building Materials Measured, In many practical

communication problems, it is not possible to avoid transmitting radio waves

through structures such as buildings, which have walls made of many

materials. The question arises as to the effect of frequency, polarization,

angle of incidence, and various other factors upon the attenuation of the

electromagnetic energy passing through a wall.

A technique was developed for measuring attenuation in various building

materials. A parallel wire grid was first used to assess the method and to

determine diffraction around the edge of a sample. Laboratory measurements were made on wooden and masonry wall materials, and outdoor measurements were made on other building materials.

Television Field Strength Analyzed, Radiofrequency spectrum

space is an urgent problem in television broadcasting. The Columbia

Broadcasting System supplied the Bureau with a large amount of data on

UHF television propagation. The Bureau is analyzing these data as part

of its program of research on VHF and UHF tropospheric propagation

characteristics. From these data, it has been determined that coverage would

be improved if more than one station would broadcast the same program

simultaneously in a given area. A recording facility was established for continuously observing fieldstrength variations at a point just beyond the radio horizon. These data are

expected to provide further information on transmission loss in the region

of greatest variability.

Tropospheric Scatter Consulting, The Bureau assisted the Army

in selecting sites and in planning the installation of some of its overseas

communications networks that will use tropospheric scatter. Propagation

paths between sites were analyzed, and performance estimates were made

for these communications systems.

An extensive site selection expedition was made in Europe and North

Africa for Air Force tropospheric scatter communications circuits. Data

from this expedition were analyzed to determine the optimum frequencies,

antenna size, and transmitter power. In predicting the performance of a

given system on these paths, the Bureau developed a service probability concept which allows for the uncertainty in the prediction process.

A similar study was made for much shorter propagation paths used between

Air Force communication relay centers and transmitter or receiver sites.

Propagation characteristics were analyzed for each path.

116
VLF Noise Effects Measured. A better understanding is needed of

radio system performance in the presence of noise. To fill this need, measurements were made of the amplitude distribution of carrier plus thermal

noise. Good agreement was found between these measurements and predictions based on a mathematical analysis. The distribution of carrier-toatmospheric noise, however, was found to differ appreciably from thermal

noise. This difference might be anticipated from the distributions of at- mospheric noise by itself. Instantaneous frequency distributions were found

to depart appreciably from a normal distribution. Under conditions of

carrier plus atmospheric noise, the shape of the instantaneous frequency

distribution was found to be similar to that obtained with farrier plus thermal

noise.

A study was made of radio systems operating in the presence of thermal

and atmospheric noise. Power requirements were calculated for various

systems operating in the presence of typical limiting noise. In addition,

the system performance factor was found very useful for comparing the

performance of various systems at various transmission rates and bandwidths.

Theoretical investigations indicated that, under certain conditions, multiple-frequency shift systems should perform better than binary frequency

shift systems. A multiple-frequency system was designed and nearly completed. This system will permit experimental investigation of the system

performance factor.

Frequency and Power Studied for VLF Standard Broadcast. A

study was made of the power requirements and of an optimum frequency for

a worldwide standard frequency broadcasting station. The expected transmission characteristics and atmospheric noise levels were calculated for the

8- to 100-kc band. When these factors are combined with carrier-to-noise

requirements for a given precision of frequency comparison, a minimum

radiated power is indicated (in the order of 10 to 100 kilowatts for frequencies in the vicinity of 20 kc) to provide worldwide coverage. To obtain

a 1 in 109 precision for these transmitter powers over typical paths, observations are required for 15 to 30 minutes.

Radio Noise Data Gathered. Data were obtained from 15 stations

in the worldwide network of radio noise recording stations. These data are

hourly values of average power, average envelope voltage, and average

logarithm of the envelope voltage, covering the frequency range from 13

kc to 20 Mc.

To supplement data from this worldwide network with information on

the detailed character of the noise, equipment was designed and constructed

to measure the amplitude-probability distribution of the noise envelope.

Measurements made with this equipment were used to develop a method that

allows a determination of the complete amplitude-probability distribution

from the three statistical moments that are automatically recorded at the field

stations.

Considerable progress was made on the development of an energy spectrum recorder that has been designed to sweep slowly across the spectrum

117
This masonry wall is typical of test structures constructed on the NBS r-f at- tenuation measurement range to study the transmission of radio waves through

buildings and other structures (page 116).

and record continuously the average noise and signal power. This equipment will provide valuable information on noise levels as well as spectrum

occupancy of signals. It will also provide propagation data over a large

number of signal paths.

Methods were developed for isolating the three types of noise that influence

recorded values. Manmade, atmospheric, and galactic noise reach the re- ceiving antenna by ionospheric and groundwave propagation, and by direct

radiation. Taking into account the prevailing propagation factors, the an- tenna pattern and source locations, these types of noise can now be analyzed

separately.

The high-altitude nuclear blasts of August 1958 were observed to change

the atmospheric noise levels recorded at Kekaha, Hawaii. Immediately following each blast, increased ionospheric absorption reduced the recorded

values by as much as 30 decibels (db) over a wide range of frequencies.

The levels remained much lower than normal for several days after each

blast. Related effects at other stations are being investigated.

Teletype Errors Measured, Teletype errors were measured in a 638-

mile tropospheric radio link. This set of measurements is one in a series

to determine the short-term, median-carrier-frequency, signal-to-noise ratio

required for radio links to give a certain performance in the presence of

various types of short-term fading and for various kinds of systems. These

systems included frequency modulation, single-side-band, dual diversity,

and quadruple diversity. Quadruple diversity was used on the long path,

and measurements were made of the correlation of the signals on the various

paths.

118
Radio Communication and Systems

The aim of the Bureau's program in radio communication and systems is

to develop and disseminate technical information relating to radio systems

that use propagation media and all frequencies of the radio spectrum. This

information is directed toward guiding engineering practices, allocating and

using radiofrequencies, and evaluating system capabilities. Standards and

measurement methods are developed for radio systems to fulfill the needs of

industry and Federal agencies involved in radio operation and regulation.

Emphasis is placed on promoting more efficient development and use of radio

systems and the radio spectrum.

New Division Established. To fulfill this mission, a new division was

established to conduct comprehensive studies of radio techniques and equipment, propagation media, antennas, noise, modulation, detection and bandwidth requirements, frequency utilization, and operational requirements of

radio services. The Radio Communication and Systems Division was

formed in January 1959 from Bureau groups in which radio-systems studies

had expanded appreciably in recent years.

In research at low and very low frequencies, experimental and analytical

studies are made of electromagnetic wave propagation, atmospheric lightning

discharges, and system techniques. In research at high and very high frequencies, experimental and analytical studies are made of techniques and

wave propagation at frequencies from approximately 0.5 to 100 Mc. Research in modulation techniques throughout the radio spectrum is concerned

with fading and multipath structure of the signals propagated by complex

media. Statistical representations of time-varying signal characteristics,

such as phase and amplitude variations, are providing bases for designing

improved equipment to detect weak fluctuating signals in a background of

radio noise. Experimental and analytical studies are made in radio navigation, positioning, and timing techniques. A substantial program of work

is carried out in antenna research, and new design techniques and measurement methods are developed. Consulting and engineering assistance is provided in selecting, designing, and testing antennas for specific applications.

In a new area of work, analytical studies will be made of overall radio system

problems, especially of new radio system concepts, frequency utilization, and

system performance. A network of ionospheric sounding stations is operated in Hawaii, Alaska, Puerto Rico, and Boulder, as well as other radio

propagation field sites at Sterling, Va., and Long Branch (Kilbourne) , 111. Arctic Communication Studied. At low and high frequencies, ionospheric radio propagation is unstable over radio paths that cross the polar

cap or that pass through regions of maximum auroral activity. These frequencies are needed for long-range communication, especially between

ground stations and aircraft or ships. Communication may be impaired,

however, for days at a time by intense absorption (caused by abnormal

ionization in the Z)-region) or by signal mutilation (caused by multipath

propagation, rapid fading, and spectral dispersion). Available statistical

119
data are inadequate for needed estimates of performance reliability over long

periods.

Studies were made of losses and fluctuation in high- and low-frequency

transmission over long paths that are subject to polar and auroral disturbances.

Transarctic Terminal Sought, For the Navy Bureau of Ships, a project was started to find an optimum geographical site for a transarctic

communication terminal in the United States. Over a pattern of receiving

stations, comparisons will be made of transmission loss statistics, fading

characteristics, and elevation angles of signals received from transmissions

in northern seas. Ionospheric Signals Studied, For Wright Air Development Center,

studies are being made of ionospheric transmission of pulse and continuous

wave signals at low and high frequencies. These studies are needed in

planning for long-range air-to-ground communications. Transmission loss

characteristics are being studied, as well as fading and dispersion of these

signals, because these factors must be appraised in developing effective modulation techniques.

Meteor Burst Communication System, An experimental communication system was operated by using meteor trails to reflect radio signals

from a transmitter to a receiver 800 miles away. With this system, messages were sent at speeds up to 4,800 words per minute—80 times the present

speed of transmission by teletype. The system was developed under the

sponsorship of the Air Force Cambridge Research Center.

A study was made of the effect of speedup ratio on the system and it appears that the system operates most effectively at 2,400 words per minute.

At this speed, and with a suitable operating threshold setting, the system

attained a daily average of 40 words per minute and had a character error

rate of 0.35 percent.

Modulation Techniques Investigated, In studies of modulation

techniques for ionospheric scatter transmission, further radiotelephone and

binary modulation problems were investigated. Phase stability of the ionspheric scatter medium was studied in relation to the limitations imposed on

phase-keying techniques for binary transmission. Methods were studied

for circumventing errors in frequency shift caused by Doppler-shifted

meteoric echoes. A simple technique was tested for using a shift index as small as required by the signaling speed. This technique was found to

reduce the Doppler errors as effectively as the conventional technique of

using a large frequency shift. Thus a way is open for reducing bandwidth

requirements of frequency shift systems. A study was also made of the

maximum usable bit rate under normal limitations of the propagation medium. Frequency and amplitude (single side band) modulation techniques

were studied for radiotelephone transmission using ionospheric scatter for

single-link and multihop relay transmissions, as well as under conditions of

multipath propagation of backscatter signals propagated in the F2 -layer.

120
In developing basic techniques for modulation studies at all frequencies,

magnetic tape recordings were made of modulated radiofrequency signals

received. Repetition of the complex fading signal is thereby made available

for analysis and comparative adjustments of detection and diversity arrangements. Techniques were developed and used for analyzing fade duration

at high and very high frequencies.

Special Antennas Developed, A major program was completed in

measuring the characteristics of corner reflector antennas. This program

led to comprehensive design information for gain and beamwidth as a function of dimensions and angle of the corner reflector. A special corner reflector antenna was developed for ionospheric scatter and meteor burst communication applications.

An antenna with 20-db gain (and having 10 collinear-driven elements)

was designed to achieve 40-db suppression of radiation outside the main

lobe, thus reducing interference and backscatter multipath effects at very

high frequencies.

Performance was measured for a number of typical commercial very high

frequency antennas, to aid in evaluating the importance of television receiving antennas in allocating television frequencies.

Tests were made on full-scale antenna systems for the Air Force, and a

theoretical study was made of interlaced rhombic antenna arrays. Further

development and instrumentation is planned for accurate measurements of

antenna performance, and arrival angles will be measured by a directive

antenna having a very high resolving power.

Polar Icecap Conductivity. In VLF propagation research, analyses

were made of atmospheric propagation associated with lightning discharges.

Atmospheric noise source characteristics were studied based on analyses of

NBS mobile laboratories make it possible to study radio conditions in many

parts of the world. At left is a unit at Boulder, Colorado, and at right is a

station in North Africa (page 116).

121
groundwaves from discharges at distances from 150 to 700 km. Attenuation

factors were computed for ranges of 1,000 to 8,000 km by comparing the

amplitude spectra of the same atmospheric disturbance that was recorded at

different distances. Based on airborne field strength measurements over

Greenland, information was obtained concerning tilt of signals, and the

conductivity and dielectric constant of the icecap.

Pulse Propagation Problem Solved. In theoretical work, modern

numerical analysis was applied to the groundwave and skywave complex

spectrum. The problem of pulse propagation for both the groundwave and

skywave was solved in a very general and rigorous manner by applying the

theory of Gaussian quadrature in evaluating the time-harmonic Fourier

integral-transform.

Radio Navigation Studies Made. Studies were made of low and very

low frequency methods for radio navigation, timing, and positioning. These

studies included analysis of propagation aspects of the Loran C navigation

technique. Studies were also made of very low frequency azimuth detection

and timing; complex spectrum recording and measurement; and data storage, selection and recording.

Space Communication Studies Begin. In the rapidly developing

field of space communications, investigations began into problems of communication between space vehicles, and space vehicles and the earth. Solutions are needed for these radio propagation and system problems to enable

the efficient system design and allocation of frequencies for space applications.

2.15. Radio Standards

The Bureau's program in radio standards consists of basic research and

development on national standards of fundamental electrical quantities,

measurement techniques, and properties of materials. A large calibration

service is provided from direct-current through microwave frequencies, and

radiobroadcasts are made of the national primary standards of frequency

and time intervals.

During the last few years, demands have increased for radio standards

of electrical quantities and for the properties of many radio materials. Extensive calibration programs are being established in military agencies, industries, and in private standards organizations. These programs depend

upon the Bureau's best reference standards. Demands for the Bureau's radio

standards services were emphasized by the results of questionnaires on

standardization needs, submitted by various professional groups to their

affiliated industries, such as the one submitted by the Aerospace Industries

Association.

Attenuation Calibration Service. In many electronic measuring instruments, radiofrequency attenuators are widely used, and there is an urgent

demand for their standardization. A calibration service was offered for

microwave attenuation from 12.4 to 18.0 kMc, and refinements are being

made so that needed accuracies can be achieved in systems for measuring

122
attenuation above and below this frequency range. Six new waveguidebelow-cutoif attenuators were built, tested, and used in measuring microwave attenuation.

A precision phase shifter was built for use in making measurements of

high-frequency attenuation. In performance tests, changes in impedance

were found to be less than 0.1 percent, as the phase shifter was varied. A new

method was devised for measuring the change in the output signal level as

the phase is varied. With this method, sensitivities were obtained which were

estimated to be better than 0.0001 decibel.

Field-Strength Standards Being Developed. Standards of field

strength are needed because of the wide use being made of field-strength

meters in establishing radar systems and communication paths. Versions

of these meters are also used to determine whether radiation levels are hazardous to personnel.

Progress was made toward establishing national standards of microwave

field strength. A microwave absorbing enclosure and its construction material are being evaluated. In this work it was found necessary to increase

the stability and resolution of the insertion loss measuring system, and

several improvements were made. A technique was also devised for investigating an optimum radiofrequency and final detector system.

Frequency Standards Improved, Scientific and government research

laboratories require frequency calibrations to accuracies approaching

those available from the national primary frequency standards. Recent

developments in satellites and missiles have emphasized the need for more

precise time measurements.

A cesium-beam apparatus was rebuilt and a precision of 2 parts in 1010 was attained. An improved atomic beam machine, nearing completion, is

expected to provide even higher precision. This machine will also have

greater reliability, convenience, and ease of operation. Plans were made for

an entirely new frequency multiplier chain that is needed for the atomic

beam machine. Comparisons were made between a chain stabilized with a maser, and a quartz oscillator cooled with liquid helium. They were found

to be equally stable for periods of 4 hours (see also p. 43)

.

Precision was improved from 1 part in 109 to a few parts in 1010 for measuring the interval between time signals broadcast by WWV and WWVH.

In cooperation with the Army Signal Corps, the Bureau made a unique

experiment that increased confidence in the method used for precise measurements of the frequency transmitted by WWV. An atomic frequency standard

was transported from place to place and intercompared with the frequency

of several widely separated atomic standards, including those at WWV and

Boulder. Measurements were made by the direct comparison method and

by means of the long-time interval method via high-frequency time signals

received at Boulder. These measurements agree to 1 part in 1010 or better.

Quartz Oscillators Investigated. Quartz crystal oscillators were investigated at 4° K, and a second-to-second frequency stability of 2 parts in

1011 was obtained. This stability is believed to be 10 times better than for

531788 O—60 9 123
any other oscillator. It was shown that aging of these crystals changes their

stability by less than 2 parts in 1011 per day over a period of 1 year. Much

of this work was done under the sponsorship of the Army Signal Research

and Development Laboratories.

In an investigation of properties of crystalline quartz as related to their

use in high-frequency resonators, various impurities were removed or introduced in quartz. The electrical conductivity of quartz was measured along

two axes, and a current anomaly was discovered which apparently relates

the removal of crystal dislocations to the electrical conductivity.

Impedance Standards Analyzed. In making accurate measurements

of attenuation, power, voltage, field strength, and other quantities, it is es- sential to know the impedance of a transmission system. The large demand

for the calibration of impedance components, such as resistors, capacitors,

and inductors, has made impedance standards vitally important.

To give full status as independent absolute standards to the new microwave impedance standards (half-round obstacles in rectangular waveguide),

a theoretical analysis is being made of finite conductivity effects and geometrical imperfections. For treating this and similar problems, a new

perturbation theory was originated. This theory is based on a general

variational principle for elements of immittance matrices of waveguide junctions, which is believed to be new, although closely related to known results.

In preparation for its use as a national reference standard at high frequencies, a 2 picofarad (2X10-12 farad) derived incremental capacitor is

being intercompared with other standards.

Impedance Calibration Techniques Developed. A suitable technique was developed for calibrating microwave impedance standards by use

of WR 90 rectangular waveguide. The technique was applied to coaxial

systems for measurements from 1 to 18 kMc.

The half,

round obstacle-type

microwave

impedance

standard

above is the

heart of a new technique for

measuring

microwave

impedance

(page 124).

124
A technique was also devised for comparing newly designed precision

short-circuit types of microwave impedance standards and for measuring

attenuation in short lengths of waveguide. This technique was shown to be

suitable for evaluating primary standards of impedance.

Receivers Analyzed for Spurious Response, When several transmitters and receivers are operated simultaneously in proximity, their output

should be limited to their principal emissions at their assigned carrier

frequencies. In developing equipment to meet this requirement, spurious

power outputs must be measured reliably. Under the sponsorship of the

Navy Bureau of Ships, the Bureau is developing standard techniques for

this purpose.

Four types of Navy receivers were analyzed for spurious responses as the

input signal level was varied. These receivers, covering the range from

14 kc to 1 kMc, will be used to measure spurious outputs of transmitters.

Attenuation characteristics were determined for 23 rejection filters (14 kc

to 1 kMc).

Noise-Measuring Equipment Designed. For some electronic instruments performance is limited by noise; and, in radio astronomy and

plasma physics, data are random (noisy) in character. Standards of noise

power, therefore, have become very important.

A microwave radiometer was developed for comparing the outputs of two

noise sources, and the final analysis of this equipment is being made. An

analysis was made of the electrical and thermometric precision required of

a high-frequency noise-generating system. Design and construction were

started for a new noise source and generator. Construction began for a

special monitor that is designed to have characteristics essential in noise

measurements. Two new input systems were devised to meet the requirements of gain stability in measuring noise power.

Power Standards Built. Standards of power are needed for measuring the range of radar and radio relay equipment as well as for measuring

the output of other power sources used in many fields of science.

The Bureau's Z-band microwave microcalorimeter was improved to an

accuracy of ±0.2 percent by refining its bolometer mounts. A second pair

of bolometer mounts was built, calibrated, and sent to England for intercomparison as recommended by Commission I of the International Scientific

Radio Union.

For use as reference standards at high frequencies, directional coupler

radiofrequency power meters were designed and built. After careful calibration by independent methods, this series of standards will be compared

with the standards of other countries.

To permit measurement of power at high frequencies, a 2-kw calorimeter

and 1-kw, 100-Mc power amplifier were built.

Voltage Calibration Services. A large number of instruments such

as radiofrequency voltmeters, voltage sources, and modulation meter* are

used throughout the electronic industry. Calibrations and standards for

these instruments are, therefore, of major importance.

125
Calibrating a directional coupler r-f power meter which was constructed to serve as a reference standard for international comparisons of r-f power standards (page 125).

With the addition of new equipment, voltage calibration services can now

be furnished from 30 kc to 400 Mc by the Electronic Calibration Center.

Recalibration of attenuator-thermoelement (AT) voltmeter reference standards showed that most remained within 1 percent of their original calibration for more than a year.

A new microvoltage console was partially completed. It will be used to

calibrate radiofrequency millivoltmeters and signal generators from 1 microvolt to 0.1 volt at the Electronic Calibration Center.

Dielectric Properties Determined. Because dielectric materials are

used in many radio and microwave applications, accurate measurements of

their properties are needed for efficient electronic designs.

A prototype copper extension cell was tested for use in a slotted-line hightemperature dielectrometer. A silver cell is being finished and will operate

to 800° C. By programing some calculations for an automatic computer,

the speed and accuracy of microwave dielectric calibrations were increased.

Dielectric properties were determined at radiofrequencies for various

materials, including samples of porcelains, boron nitride, crude oil and oil

shale, and both fresh water and sea water.

Magnetic Properties of Materials Measured. Magnetic materials

are used extensively in commercial and military electronic systems. To

support the vast effort being directed toward studying and applying these

materials, new and better measuring techniques, equipment, and standards

are needed, as well as fundamental studies of the properties of these materials.

Work during the last year was concerned with all of these areas. 126
A quasi-static hysteresis loop plotter was completed, as was a series of

improved permeameters designed to shorten the time required to measure

magnetic spectra and to improve the precision of Q measurements. Improvements were also made to four other instruments used to study the spectra

of ferrites or to make measurements of permeability. A calorimeter was

completed for measuring high-power radiofrequency loss in ferrites as a

function of a-c field strength at 300 kc.

The properties of ferrite materials were investigated under the sponsorship

of the Navy Bureau of Ships. Complex permeability data were obtained for

48 materials (144 toroids) at 100 and 300 Mc, and their total loss was

measured as a function of magnetic field strength at 0.3 Mc (48 toroids).

Reversibility permeability was measured for eight additional materials (24

toroids)

.

In related projects, microwave tensor permeability and dielectric constants

were measured for selected ferrites. Instrumentation was put into operation

for making these measurements at additional frequencies. When correlated

Bureau scientists explain a low-temperature microwave experiment to an

Australian microwave physicist. The equipment was used in studying the

conductivity properties of germanium (page 126).

127
Table Mesa, near Boulder, Colorado, is an excellent natural site for a wide

variety of radio research programs. For example, it serves as an antenna

testing range, and is the receiving end for radio paths having transmitters at

Long Branch, Illinois, Haswell, Colorado, and Barrow, Alaska. Inset shows the

experimental setup on Table Mesa for measuring the performance characteristics of corner reflector antennas (page 121).

with other physical properties, these data will permit more effective evaluation of the ferrites for specific electromagnetic requirements.

Ferrites Laboratory, With support from the Navy Bureau of Ships,

the Bureau is establishing a ferrites laboratory to coordinate and evaluate

the work on radio and microwave magnetism in this country. The laboratory will explore basic phenomena and develop standard methods and techniques for evaluating rapid advances in magnetic materials and devices. A

facility will also be maintained for reference testing.

Microwave Interferometers Developed, Preparations were made

for a precise experimental determination of the velocity of light. A wavelength of 6.28 mm will be used in a microwave Michelson interferometer

operating in the Fresnel region of diffraction.

A pilot model of a microwave Fabry-Perot interferometer was operated at a wavelength of 6 mm. The fringes obtained were the sharpest ever reported

for this type interferometer, and the work shows the superiority of the microwave form of this interferometer over its optical counterpart.

Time and Frequency Standards, To make the national standards of

frequency and time intervals readily available, broadcasts were made continuously from WWV (Beltsville, Md.) ; WWVH (Maui, Hawaii) ; and from

KK2XEI (an experimental 60-kc station at Boulder, Colo.). These broad128
casts are widely used by industry, government agencies, and schools, in

research activities, defense systems, communications, navigation, broadcasting, and manufacturing.

The frequency transmitted by WWV was measured daily at the Boulder

Laboratories in terms of atomic standards by means of the time-interval

method. Measurements made at Beltsville were compared with a second

atomic standard. The results showed that, when a suitable averaging period

is used, the time-interval method will give values within a few parts in 1010

of the actual transmitted frequency. Numerous improvements were made

in the WWV electronic equipment to increase the stability and reliability

of the transmitted signals.

The experimental 60-kc broadcast continued to furnish many users with

a service that is much more accurate than the one supplied by WWV. The

low radiated power of this broadcast, however, has limited its use. Because

many research, military, and industrial organizations need the higher

accuracies of the 60-kc broadcast, considerable planning work was done

toward a high-power standard broadcast station near Boulder. Measurements and theoretical studies have shown that at very low frequency, the

received frequency may be 1,000 times more precise than at high frequency.

As a direct result of some of these studies, a method was under development

for modulating time-signal, very-low-frequency carriers so that the station

will permit frequency and time-interval calibrations to a precision and accu- racy far greater than at high frequency.

Mobile laboratory containing recording apparatus and roof turntable used to

track aircraft in antenna evaluations for the U.S. Air Force (page 121).

129
Electronic Calibration Center. This Center provides extensive calibration services for industry and Defense Department agencies that are engaged in very rapidly expanding their own standards and calibration

programs.

Fiscal year 1959 was the first full year of operation of the Center. Although instrumentation for the Center was far from complete, it was possible to meet a large part of the increasing demand for calibration services,

in those areas in which national standards had been set up. As was ex- pected, the low-frequency calibration service expanded rapidly since measurement techniques and calibration equipment were made available. Coaxial and waveguide attenuators, and couplers at microwave frequencies were

a large part of the total calibration work at the higher frequencies. Many

needed calibration services were not offered because of the lack of suitable

measurement techniques and instrumentation.

Instrumentation initially planned for the low-frequency region provides

for calibrating electrical instruments, resistors and resistance apparatus, inductors and capacitors, standard cells, current and voltage transformers, and

miscellaneous, including ratio devices. Calibration facilities are being es- tablished for instruments measuring high-frequency voltage, power, impedance, attenuation, and field-strength. In the microwave region, instrumentation is being prepared for precision calibrations of instruments measuring

power, impedance, attenuation, frequency, and noise.

2.16. Weights and Measures

One of the statutory responsibilities of the National Bureau of Standards

is "cooperation with the States in securing uniformity in weights and measures laws and methods of inspection." The responsibility of regulatory

control over commercial weighing and measuring devices and commercial

transactions involving quantity has been left by the Congress to the individual states. The Bureau contributes by offering consultative and advisory

services to the States and calibration and physical adjustment of State reference weights and measures standards.

This program is implemented through the Bureau's Office of Weights and

Measures. The range of services is quite broad, including: (1) Development of model weights and measures statutes, rules, and regulations; (2)

properly designed and accurate physical standards of length, mass, and ca- pacity; (3) effective procedures for testing commercial weighing and measuring devices; (4) specially designed testing equipment; (5) plans for systematic and effective quantity checking of prepackaged merchandise; (6)

administrative procedures; (7) specifications and tolerances for commercial

devices; (8) training schools for weights and measures officers; (9) visual

aids; and (10) publications.

The Office of Weights and Measures was relocated during the year to provide space for a training laboratory and for the weights and measures ar- chival and reference library. A comprehensive collection of published material on weights and measures in the United States is being assembled in

130
the special library. Its facilities will be available not only to the Bureau's

staff but to all students and researchers in this field.

The training laboratory will facilitate the development of testing procedures and will enable the Bureau to offer short, comprehensive courses to

supervisory and training personnel of State and large local jurisdictions in

the many facets of weights and measures supervision. The demand for such

training continues to grow. Requests by the States for formal technical

training schools are such as to severely tax the facilities and staff of the

Office of Weights and Measures. The results of this program are very en- couraging, as evidenced by more uniform, more effective, and more efficient

weights and measures supervision at the State and local levels.

The Bureau was called upon by the governments of several States for as- sistance in the preparation of weights and measures legislation. Complete

statutes, based on the model weights and measures law, were enacted in

Washington, New Mexico, and Missouri, and major amendments to existing

laws were adopted in other States.

A significant addition to the technical literature was published during the

year, "Checking Prepackaged Commodities," a handbook for weights and

measures officials. The first such publication in the field, it presents a guide for checking packaged commodities as to the accuracy of their quantity

declarations, with a procedure based on sound statistical sampling principles.

At the request of the National Conference on Weights and Measures, effort is being devoted to the development of new physical standards of weights

and measures for the States—standards that will be more accurate, more

constant, and more durable. Basic studies in materials and design were

completed during the year. In 1836 and in 1866, the Congress provided

the States with reference standards that became the basis for nationwide

uniformity. Since then, through obsolescence and some individual purchases, nonuniformity in the physical characteristics of the standards has

developed among the States. The Bureau's current efforts will provide a sound basis for repeating the 19th-century actions. This would bring about

complete uniformity among the States in the area of weights and measures

reference standards.

In an impressive ceremony held at the Bureau during the year, a set of

weights and measures comprising standards of length, mass, and capacity was

presented to the new State of Alaska by Secretary of Commerce Lewis L.

Strauss. These standards are providing a firm basis for an accurate, uniform measurement system in the new State, so vital to the growth of commerce and industry.

Traditionally, the National Conference on Weights and Measures has been

one of the principal means of promoting uniformity and raising performance standards in weights and measures administration in the United States.

Sponsored by the Bureau, the 44th Annual Conference was held in Washington D.C., during the year. Thirty-nine States, Puerto Rico, and the

District of Columbia were officially represented at this 5-day meeting by

197 delegates out of a total registered attendance of 389.

131
2.17. Basic Instrumentation

The fundamentals of measurement and control were emphasized in the

Bureau's research and development in basic instrumentation. An instrument reference service was operated and enlarged, research and development

continued on information retrieval systems, and instrumentation methods

were surveyed. Support for this program was contributed by the Office of

Naval Research, the Department of Defense, and the Atomic Energy

Commission.

Instrument Reference Service Enlarged, Industrial and government scientists must know what has been done in developing instruments

to establish effective designs without duplication of effort. The Bureau's

office of basic instrumentation provides reference and consultation services

for all scientists who work in research and development of scientific

instruments.

The Bureau enlarged its card index of instrumentation literature by

selecting, analyzing, coding, and recording additional information in a

special punched-card system. A large, number of inquiries were answered

by use of references already stored in this index system.

Work continued on developing methods of replicating the punched cards

used in the Bureau's instrument reference files. A design was completed

for an electromechanical device to increase the speed and efficiency of

searching the instrument index.

Instrumentation Methods Surveyed. A survey was made of recording surfaces and marking methods used in industrial processes or for laboratory experiments. This survey was published as NBS Circular 601, and

work is continuing on the second part of the survey, dealing with recorder

principles and mechanisms. A survey was started on electrical methods of

varying capacitance. A survey was also made of the Bureau's need for

automatic data taking in its research work, and a number of useful applications were found for these methods.

132
3. Appendixes

3.1. Organization of The National Bureau of Standards*

Director—Allen V. Astin

Deputy Director—Robert D. Huntoon

Assistants to the Director

Henry Birnbaum and C. N. Coates

Consultants to the Director

F. G. Brickwedde, L. F. Curtiss,

A. G. McNish, and C. H. Page

Associate Director for Physics

Robert D. Huntoon

Associate Director for Engineering

Archibald T. McPherson

Associate Director for Chemistry

Edward Wichers

Consultants to the Associate Director

W. Souder and M. B. Wallenstein

Associate Director for Planning

Irl C. Schoonover

NBS Reactor Program

C. O. MUEHLHAUSE

Associate Director for Administration

R. S. Walleigh

Associate Director for the Boulder Laboratories

Frederick W. Brown

Director Emeritus

Lyman J. Briggs

SCIENTIFIC AND TECHNICAL DIVISIONS AND

SECTIONS

ELECTRICITY AND ELECTRONICS, C. H. Page, Acting Chief

Resistance and Reactance, J. L. Thomas

Electron Devices, C. P. Marsden,

Electrical Instruments, F. M. Defandorf

Magnetic Measurements, I. L. Cooter

Dielectrics, J. D. Hoffman

Engineering Electronics, G. Shapiro

Electronic Instrumentation, G. F. Montgomery

Electrochemistry, W. J. Hamer

OPTICS AND METROLOGY, A. G. McNish, Acting Chief

D. B. Judd, Assistant Chief

Photometry and Colorimetry, L. E. Barbrow

Optical Instruments, F. E. Washer

Photographic Technology, C. S. McCamy

Length, B. L. Page, Acting

Engineering Metrology, I. H. Fullmer

•As of Sept. 1, 1959. 133
HEAT, C. M. Herzfeld, Chief

K. E. Shuler, Consultant

Temperature Physics, J. F. Swindells

Thermodynamics, C. W. Beckett

Cryogenic Physics, R. P. Hudson

Rheology, R. S. Marvin

Molecular Kinetics, F. L. Howard

Free Radicals Research, A. M. Bass

ATOMIC AND RADIATION PHYSICS, L. S. Taylor, Chief

Atomic Physics Laboratory

Spectroscopy, K. G. Kessler

Radiometry, E. K. Plyler

Mass Spectrometry, F. L. Mohler

Solid State Physics, H. P. R. Frederikse

Electron Physics, L. L. Marton

Atomic Physics, L. M. Branscomb

Radiation Physics Laboratory, H. 0. Wyckoff, Chief

Neutron Physics, R. S. Caswell

Radiation Theory, U. Fano

Radioactivity, W. B. Mann

X-ray, H. O. Wyckoff

High Energy Radiation, H. W. Koch

Nucleonic Instrumentation, L. Costrell

Radiological Equipment, S. W. Smith

CHEMISTRY, E. Wichers, Acting Chief

R. G. Bates, Acting Assistant Chief

Organic Coatings, P. T. Howard

Surface Chemistry, W. W. Walton

Organic Chemistry, H. S. Isbell

Analytical Chemistry, H. A. Bright

Inorganic Chemistry, R. Gilchrist

Electrodeposition, A. Brenner

Molecular Structure and Properties of Gases, F. Buckley

Physical Chemistry, R. G. Bates

Thermochemistry, E. J. Prosen

Spectrochemistry, B. F. Scribner

Pure Substances, C. P. Saylor

MECHANICS, B. L. Wilson, Chief

W. G. Bromhacher, Consultant

J. M. Frankland, Consultant

Sound, R. K. Cook

Mechanical Instruments, E. C. Lloyd

Fluid Mechanics, G. B. Schubauer

Engineering Mechanics, L. K. Irwin

Mass and Scale, H. S. Peiser

Capacity, Density, and Fluid Meters, C. T. Collett, Acting

Combustion Controls, F. R. Caldwell

ORGANIC AND FIBROUS MATERIALS, G. M. Kline, Chief

Rubber, L. A. Wood

Textiles, H. F. Schiefer

Paper, R. B. Hobbs

Leather, J. R. Kanagy

Testing and Specifications, R. D. Stiehler

Polymer Structure, N. P. Bekkedahl

Plastics, F. W. Reinhart

Dental Research, W. T. Sweeney

134
METALLURGY, J. I. Hoffman, Chief

T. G. Digges, Assistant Chief

Thermal Metallurgy, T. G. Digges

Chemical Metallurgy, L. L. Wyman

Mechanical Metallurgy, J. A. Bennett

Corrosion, G. A. Ellinger

Metal Physics, L. M. Kushner

MINERAL PRODUCTS, I. C. Schoonover, Acting Chief

C. H. Hahner, Assistant Chief

L. H. Adams, Consultant

R. F. Geller, Consultant

Engineering Ceramics, M. D. Burdick

Glass, C. H. Hahner

Refractories, C. H. Hahner, Acting

Enameled Metals, W. N. Harrison

Constitution and Microstructure, H. F. McMurdie

BUILDING TECHNOLOGY, D. E. Parsons, Chief

H. R. Snoke, Assistant Chief

W. F. Roeser, Consultant

Structural Engineering, D. Watstein

Fire Protection, A. F. Robertson

Air Conditioning, Heating, and Refrigeration, P. R. Achenbach

Floor, Roof, and Wall Coverings, H. R. Snoke

Codes and Safety Standards, J. A. Dickinson

Heat Transfer, H. E. Robinson

Concreting Materials, R. L. Blaine

APPLIED MATHEMATICS, E. W. Cannon, Chief

F. L. Alt, Assistant Chief

Numerical Analysis, P. J. Davis

Computation, E. W. Cannon, Acting

Statistical Engineering, C. Eisenhart

Mathematical Physics, R. F. Dressler

DATA PROCESSING SYSTEMS, S. N. Alexander, Chief

H. K. Skramstad, Assistant Chief

for Systems

SEAC Engineering Group, P. D. Shupe, Jr.

Components and Techniques, R. D. Elbourn

Digital Circuitry, S. Greenwald

Digital Systems, A. L. Leiner

Analog Systems, H. K. Skramstad

Applications Engineering, S. N. Alexander, Acting

OFFICE OF WEIGHTS AND MEASURES, W. S. Bussey, Chief

M. W. Jensen, Assistant

Chief

R. W. Smith, Consultant

OFFICE OF BASIC INSTRUMENTATION, W. A. Wildhack, Chief

J. Stern, Assistant Chief

OFFICE OF TECHNICAL INFORMATION, W. R. Tilley, Chief

W. K. Gautier, Assistant

Chief

135
ADMINISTRATIVE DIVISIONS

Accounting, H. E. Hardaway

Personnel, G. R. Porter

Administrative Services, H. P. Dalzell

Shops, F. P. Brown

Supply, G. B. Kefover

Management Planning, I. Asay

Budget, N. L. Christeller

Internal Audit, J. P. Menzer

Plant, H. Graham

BOULDER LABORATORIES, F. W. Brown, Director

Boulder, Colorado

Gaseous Physics Group, J. M. Richardson

Consultant in Statistics, E. L. Crow

Consultant in Astrophysics, R. N. Thomas

Consultant in Radio Wave Propagation, J. R. Wait

Consultant in Mathematics, J. Sopka

CRYOGENIC ENGINEERING, R. B. Scott, Chief

B. W. Birmingham, Assistant Chief

Cryogenic Equipment, R. B. Jacobs

Cryogenic Processes, B. W. Birmingham

Properties of Materials, R. J. Corruccini

Gas Liquefaction, V. J. Johnson

RADIO PROPAGATION PHYSICS,* R. J. Slutz, Chief

D. M. Gates, Assistant Chief

A. H. Shapley, Assistant Chief

T. N. Gautier, Consultant

D. K. Bailey, Consultant

Upper Atmosphere Research, R. M. Gallet

Ionosphere Research, E. K. Smith, Jr.

Regular Prediction Services, W. B. Chadwick

Sun-Earth Relationships, R. W. Knecht

VHF Research, K. L. Bowles

Radio Warning Services, Miss J. V. Lincoln

Airglow and Aurora, F. E. Roach

Radio Astronomy and Arctic Propagation, C. G. Little

RADIO PROPAGATION ENGINEERING,* K. A. Norton, Chief

J. W. Herbstreit, Assistant Chief

E. F. Florman, Consultant

Data Reduction Instrumentation, W. E. Johnson . Radio Noise, W. Q. Crichlow

Tropospheric Measurements, C. F. Peterson

Tropospheric Analysis, P. L. Rice

Propagation-Terrain Effects, R. S. Kirby

Radio-Meteorology, B. R. Bean

Lower Atmosphere Physics, M. C. Thompson, Jr.

*These divisions comprise the Central Radio Propagation Laboratory.

136
RADIO COMMUNICATION AND SYSTEMS,* R. C. Kirby, Chief

D. W. Patterson, Assistant Chief

A. D. Watt, Assistant Chief

G. W. Haydon, Consultant

Low Frequency and Very Low Frequency Research, A. G. Jean

High Frequency and Very High Frequency Research, R. Silberstein

Modulation Systems, J. w. Koch

Antenna Research, H. V. Cottony

Navigation Systems, G. Hefley

Systems Analysis, W. C. Coombs

Field Operations, H. G. Sellery

RADIO STANDARDS, W. D. George, Acting Chief

W. D. George, Assistant Chieffor Radio Frequencies

D. M. Kerns, Assistant Chieffor Microwave Frequencies

E. C. Wolzien, Assistant Chieffor Technical Planning

and Coordination

W. W. Brown, Consultant

P. F. Wacker, Consultant

High-Frequency Electrical Standards, M. C. Selby

Radio Broadcast Service, A. H. Morgan

Radio and Microwave Materials, J. L. Dalke

Electronic Calibration Center, H. W. Lance

Microwave Circuit Standards, R. W. Beatty

ADMINISTRATIVE DIVISION, S. W. J. Welch

NATIONAL BUREAU OF STANDARDS FIELD ESTABLISHMENTS

Lamp Inspector, Brookline, Mass.

Visual Landing Aids Field Lab., Areata, Calif.

Master Railway Track Scale Depot, Clearing, 111.

Materials Testing Laboratories:

Allentown, Pa. San Francisco, Calif.

Denver, Colo. Seattle, Wash.

Radio Transmitting Station WWV, Beltsville, Md.

Maui Ionosphere and WWVH Station, Maui, Hawaii

Central Radio Propagation Laboratory Field Stations:

Anchorage, Alaska Sunset, Colo.

Barrow, Alaska Table Mesa, Colo.

Marie Byrd Base, Antarctica Kekaha, Hawaii

Pole Station, Antarctica Long Branch, 111. Cheyenne Mountain, Colo. San Juan, P.R.

Fritz Peak, Colo. Fort Belvoir, Va.

Gunbarrel Hill, Colo. Front Royal, Va.

Haswell, Colo. Sterling, Va.

Lafayette, Colo. Bill, Wyo.

137
3.2. Fiscal Data on NBS Program

Program and Source of Financing Obligations Incurred

(in thousands of dollars)

Supported by NBS Appropriations:

Operating Programs:

H .YTIATI GAG

Construction and Facilities Programs:

Plant ann In irnlTiTinf^ni' $569

2, 140

$12, 379

2,709

Total NBS Appropriations $15, 088

ijUUUUI LC/U. VJ y V/ J. Ulllioi Research and Development Programs:

Other Federal Agencies

Nongovernmental Sources

14, 720

143

Calibrations, Testing, and Standard SamT~i AC

Reimbursable Administrative Services . . .

14, 863

3, 732

1, 156

19, 751

34, 839

138
3.3. Public Law 85—890 Amending Organic Act of the National

Bureau of Standards

Public Law 85-890

85th Congress, S. 2114

September 2, 1958

AN ACT

National Bureau of Standards.

Field sites. 70 Stat. 959. 15 USC 271

et seq.

Improvements, etc.

Functions.

72 Stat. 1711.

72 Stat. 1712.

59 Stat. 296, 298. 68 Stat. 1109.

5 USC 911 et seq, 921 et seq.

15 USC 278a.

Repeal.

64 Stat. 370.

15 USC 285, 286.

To amend the Act of March 3, 1901 (31 Stat. 1449), as amended, to incorporate

in the Organic Act of the National Bureau of Standards the authority to ac- quire land for field sites, to undertake construction and improvement of buildings

and for other activities. Be it enacted by the Senate and House of Representatives of the

United States of America in Congress assembled, That the Act entitled "An Act to establish the National Bureau of Standards", approved March 3, 1901, as amended, is amended by adding the

following sections:

"Sec. 13. To the extent that funds are specifically appropriated

therefor, the Secretary of Commerce is authorized to acquire land

for such field sites as are necessary for the proper and efficient

conduct of the activities authorized herein.

"Sec 14. Within the limits of funds which are appropriated for

the National Bureau of Standards, the Secretary of Commerce is authorized to undertake such construction of buildings and other

facilities and to make such improvements to existing buildings,

grounds, and other facilities occupied or used by the National

Bureau of Standards as are necessary for the proper and efficient

conduct of the activities authorized herein: Provided, That no improvement shall be made nor shall any building be constructed under

this authority at a cost in excess of $40,000 unless specific provision

is made therefor in the appropriation concerned.

"Sec. 15. In the performance of the functions of the National

Bureau of Standards the Secretary of Commerce is authorized to undertake the following activities: (a) The purchase, repair, and

cleaning of uniforms for guards; (b) the repair and alteration of

buildings and other plant facilities; (c) the rental of field sites and

laboratory, office, and warehouse space; (d) the purchase of reprints

from technical journals or other periodicals and the payment of page

charges for the publication of research papers and reports in such

journals; (e) the furnishing of food and shelter without repayment

therefor to employees of the Government at Arctic and Antarctic

stations; (f) for the conduct of observations on radio propagation

phenomena in the Arctic or Antarctic regions, the appointment of

employees at base rates established by the Secretary of Commerce

which shall not exceed such maximum rates as may be specified

from time to time in the appropriation concerned, and without re- gard to the civil service and classification laws and titles II and

III of the Federal Employees Pay Act of 1945; and (g) the erection on leased property of specialized facilities and working and living

quarters when the Secretary of Commerce determines that this will

best serve the interests of the Government."

Sec. 2. Such Act is further amended in section 11, paragraph (a)

by striking out the word "therein" and substituting therefor the

word "herein".

Sec. 3. The Act entitled "An Act to provide authority for certain

functions and activities in the Department of Commerce and for

other purposes" approved July 21, 1950, is hereby repealed in its entirety.

Approved September 2, 1958.

531788 O—60 10 139
3.4. Advisory Committees

STATUTORY VISITING COMMITTEE

[Reports annually to Secretary of Commerce on NBS activities (Dates indicate expiration of appointment) ] Dr. M. J. Kelly, Former President and Chairman of the Board, Bell Telephone Laboratories, Inc. (1962) , Chairman

Dr. Crawford H. Greenewalt, President, E. I. du Pont Nemours & Co. (1959)

Dr. Detlev W. Bronk, President, National Academy of Sciences (1960)

Professor F. Seitz, University of Illinois (1961)

Dr. Lloyd V. Berkner, President, Associated Universities Inc. (1963)

Technical Advisory Panels

[Appointed by the National Academy of Sciences-National Research Council in cooperation with the leading scientific and technical societies to advise NBS Director in

specific technical areas. Cooperating societies are: American Ceramic Society

(ACerS) ; American Chemical Society (ACS) ; American Institute of Chemical Engineers (AIChE) ; American Institute of Electrical Engineers (AIEE) ; American

Institute of Mining, Metallurgical, and Petroleum Engineers (AIME) ; American

Institute of Physics (AIP) ; American Society of Civil Engineers (ASCE) ; American

Society of Mechanical Engineers (ASME) ; Conference Organization for Mathematical Sciences (COMS) ; and Institute of Radio Engineers (IRE). Members listed

served during fiscal year 1959]

Dean R. B. Lindsay, Brown University, Chairman, Committee of Panel Chairmen

Dr. O. F. Schuette, National Research Council, Executive Secretary

ADVISORY PANEL TO ELECTRICITY AND ELECTRONICS DIVISION

Prof. W. A. Lewis, Illinois Institute of Technology, Chairman (AIEE)

Prof. Norman I. Adams, Jr., Yale University (AIP)

Dr. John G. Brainerd, University of Pennsylvania (IRE)

Mr. H. P. Corwith, Western Union Telegraph Company (AIEE)

Mr. Rorert W. Larson, General Electric Research Laboratories (AIEE)

Prof. Henry B. Linford, Columbia University (ACS)

Mr. Leon Podolsky, Sprague Electric Company (IRE)

ADVISORY PANEL TO OPTICS AND METROLOGY DIVISION

Prof. John Strong, Johns Hopkins University, Chairman (AIP)

Prof. Clarence E. Bennett, University of Maine (AIP)

Mr. Floyd W. Hough, Arlington, Virginia (ASCE)

Mr. Paul V. Miller, Taft Pierce Manufacturing Company (ASME)

Dr. Brian O'Brien, Pomfret, Conn. (AIP)

ADVISORY PANEL TO HEAT DIVISON

Prof. Mark W. Zemansky, City College of New York, Chairman (AIP)

Prof. C. Harold Berry, Belmont, Mass. (ASME)

Prof. Henry A. Fairbank, Yale University (AIP)

Dean Henry Eyring, University of Utah (ACS)

Prof. Joseph Kestlin, Brown University (ASME)

Dean R. B. Lindsay, Brown University (AIP)

Prof. J. E. Mayer, University of Chicago (ACS)

Prof. Glen C. Williams, Massachusetts Institute of Technology (AIChE)

ADVISORY PANEL TO ATOMIC AND RADIATION PHYSICS

DIVISION

Prof. A. 0. C. Nier, University of Minnesota, Chairman (AIP)

Prof. John Bardeen, University of Illinois (AIP)

Prof. J. W. M. DuMond, California Institute of Technology (AIP)

Dr. William A. Higinbotham, Brookhaven National Laboratory (IRE)

Prof. Polykarp Kusch, Columbia University (AIP)

Prof. Harold A. Lamonds, North Carolina State College (AIEE)

Dr. Otto Oldenberg, Harvard University (AIP)

Dr. H. M. Parker, General Electric Co. (AIP)

140
ADVISORY PANEL TO CHEMISTRY DIVISION

Prof. F. Daniels, University of Wisconsin, Chairman (ACS)

Prof. N. Howell Furman, Princeton University (ACS)

Prof. Hans H. Jaffe, University of Cincinnati (ACS)

Dr. J. R. Ruhoff, Malinckrodt Chemical Company (ACS)

Dr. Norman A. Shepard, Stamford, Conn. (ACS)

ADVISORY PANEL TO MECHANICS DIVISION

Dean Dana Young, Yale University, Chairman (ASME)

Prof. Lynn S. Beedle, Lehigh University (ASCE)

Prof. S. R. Beitler, Ohio State University (ASME)

Prof. A. T. Ippen, Massachusetts Institute of Technology (ASCE)

Dr. H. F. Olson, Radio Corporation of America ( AIP)

Prof. Jesse Ormondroyd, University of Michigan (ASME)

Dr. Milton Plesset, California Institute of Technology (AIP)

ADVISORY PANEL TO ORGANIC AND FIBROUS MATERIALS

DIVISION

Dr. Norman A. Shepard, Stamford, Conn., Chairman (ACS)

Dr. J. H. Dillon, Textile Research Institute (AIP)

Dr. Milton Harris, Harris Research Laboratory (ACS)

Prof. Herman F. Mark, Polytechnic Institute of Brooklyn (AIP)

Prof. C. S. Marvel, University of Illinois (ACS)

Dr. J. F. Downie Smith, Carrier Corporation (ASME)

ADVISORY PANEL TO METALLURGY DIVISION

Dr. Clarence Sims, Battelle Memorial Institute, Chairman (AIME)

Dr. D. J. Dienes, Brookhaven National Laboratory (AIP)

Mr. John Freeman, Jr., American Brass Company (ASME)

Dr. Maxwell Gensamer, Columbia University (ASME)

Dr. Francis L. LaQue, International Nickel Company (ACS)

Mr. Arthur R. Lytle, Electro-Metallurgical Co. (AIME)

Dean Elburt Osborn, Pennsylvania State University (ACerS)

Dr. Joseph A. Pask, University of California (ACerS)

Dr. Albert J. Phillips, American Smelting and Refining Co. (AIME)

Dr. Cyril S. Smith, University of Chicago (AIME)

Dr. E. C. Smith, Republic Steel Corporation (AIME)

ADVISORY PANEL TO MINERAL PRODUCTS DIVISION

Dean Elburt Osborn, Pennsylvania State University, Chairman (ACerS)

Mr. Herbert Insley, Washington, D.C. (ACerS)

Dr. Norbert J. Kreidl, Bausch and Lomb Optical Company (ACerS)

Mr. John T. Roberts, Ingersoll-Humphreys Division Borg-Warner (ACerS)

Prof. Pierce Selwood, Northwestern University (ACS)

Mr. Karl Schwartzwalder, General Motors Corporation (ACerS)

Dr. Robert B. Sosman, Rutgers, The State University (ACerS)

Prof. Bertram E. Warren, Massachusetts Institute of Technology (AIP)

Dr. Clarence Zener, Westinghouse Electric Corporation (AIME)

ADVISORY PANEL TO BUILDING TECHNOLOGY DIVISION

Dr. G. H. Hickox, Fort Belvoir, Va., Chairman (ASCE)

Mr. G. M. Jusinberre, Wellsboro, Pa. (ASME)

Dr. James F. Eversole, Union Carbide Development Corporation (ACS)

Mr. W. C. Hansen, Universal Atlas Cement Company (ASCE)

Prof. Robert A. Hechtman, The George Washington University (ASCE)

Mr. Paul V. Johnson, Structural Clay Products Research Foundation (ACerS)

Dean W. L. McCabe, Polytechnic Institute of Brooklyn ( AIChE)

Dr. John S. Parkinson, Johns-Manville Products Corporation (AIP)

Mr. Raymond C. Reese, Toledo, Ohio (ASCE)

141
ADVISORY PANEL TO APPLIED MATHEMATICS DIVISION

Prof. A. H. Taub, University of Illinois, Chairman (COMS)

Prof. David Blackwell, University of California (COMS)

Dr. Alston S. Householder, Oak Ridge National Laboratory (COMS)

Prof. Mark Kac, Cornell University (COMS)

Prof. Philip M. Morse, Massachusetts Institute of Technology (COMS)

Prof. J. Walsh, Harvard University (COMS)

ADVISORY PANEL TO DATA PROCESSING SYSTEMS DIVISION

Dr. Alston S. Householder, Oak Ridge National Laboratory, Chairman (COMS)

Mr. John C. McPherson, International Business Machines Corporation (IRE)

Prof. Charles L. Miller, Massachusetts Institute of Technology ( ASCE)

Prof. Raymond Pepinsky, Pennsylvania State University (AIP)

Prof. William H. Radford, Massachusetts Institute of Technology (IRE)

Mr. Morris Rubinoff, Philco Corporation (AIEE)

ADVISORY PANEL TO CRYOGENIC ENGINEERING DIVISION

Prof. Charles Squire, The Rice Institute (AIP)

Prof. S. C. Collins, Massachusetts Institute of Technology (ASME)

Mr. A. Latham, Jr., Arthur D. Little Company (AIChE)

Dr. Clyde McKinley, Air Products Incorporated (AIChE)

ADVISORY PANEL TO CENTRAL RADIO PROPAGATION

LABORATORY

Prof. Henry G. Booker, Cornell University, Chairman (IRE)

Mr. Stuart L. Bailey, Washington, D.C. (IRE)

Mr. A. B. Crawford, Bell Telephone Laboratories

Dr. S. W. Herwald, Westinghouse Electric Corporation (AIEE)

Dr. John S. Smyth, Smyth Research Associates (AIP)

Prof. A. H. Waynick, National Science Foundation (IRE)

Dr. H. W. Wells, Carnegie Institution of Washington (IRE)

Prof. J. B. Wiesner, Massachusetts Institute of Technology (IRE)

ADVISORY PANEL TO RADIO STANDARDS DIVISION

Prof. E. C. Jordan, University of Illinois, Chairman (IRE)

Prof. Walter Gordy, Duke University (AIP)

Prof. W. A. Lewis, Illinois Institute of Technology (AIEE)

Prof. Arthur A. Oliner, Polytechnic Institute of Brooklyn (IRE)

Dr. John C. Simons, National Research Corporation (IRE)

Mr. Robert C. Sprague, Sprague Electric Company (AIEE)

WEIGHTS AND MEASURES ADVISORY COMMITTEE

[Members are nominated by the National Conference on Weights and Measures!

Dr. A. T. McPherson, National Bureau of Standards, Chairman

Mr. C. M. Fuller, Sealer of Weights and Measures, Los Angeles County, Calif.

Mr. W. A. Scheurer, Exact Weight Scale Company

Prof. L. J. Gordon, Weights and Measures Research Center, Dennison University

Mr. Rollin E. Meek, State Board of Health, Indiana

Commissioner P. C. Brinkley, State Department of Agriculture and Markets, Virginia

Mr. L. T. Gustafson, Creamery Package Manufacturing Company

ASA-ASTM ADVISORY COMMITTEES

For many years the National Bureau of Standards has worked in close cooperation

with the American Standards Association and the American Society for Testing Materials. The committees designated by these organizations to advise the Director of the

Bureau in areas of mutual interest currently are being reorganized.

142
3.5. Awards and Honors

Recognition of the Bureau's contributions to science and technology often takes the

form of awards and honors from government, academic, professional, and industrial

groups. The following list reflects such recognition bestowed on Bureau staff members

during the fiscal year 1959.

RECIPIENT

achenbach, paul r. Blum, William

(Retired)

Branscomb, Lewis M.

Brode, Wallace R. (On leave of absence)

Broida, Herbert P. Brombacher, William G. Bussey, William S.

Cassel, James M.

Danos, Michael

Davis, Marion M.

Dickinson, John A.

Digces, Thomas G. Geller, Roman F.

Herbstreit, Jack W.

Hoffman, James I.

Kanacy, Joseph R.

Lide, David R., Jr. Manoelkern, Leo

Meggers, William F. (Retired)

Paffenbarger, George C. (Research Associate)

Parsons, Douclas E.

Reinhart, Frank W.

Scott, Arnold H.

Scribner, Bourdon F. Smith, Ralph W.

Sterrett, Kay F. Stiehler, Robert D. Sweeney, William T. Tchen, Chan-Mou

Teele, Ray P.

HONOR

Elected Fellow of the American Society of Heating, Refrigerating and

Air Conditioning Engineers.

William Blum Award of the Washington-Baltimore Section, Electro- chemical Society.

Physics Award of the Washington Academy of Sciences. Sixth Annual Award of the Society of Applied Spectroscopy.

Senior Fellowship grant from the National Science Foundation.

Honorary Membership in the Instrument Society of America.

Elected Vice President of the Institute of Weights and Measures

Administration in England.

Honorary Membership in the Southern Weights and Measures Association. Alsop Award of the American Leather Chemists Association. Fellowship grant from the John Simon Guggenheim Memorial Foundation.

Chosen to deliver the Marie Curie Lecture for 1958 by the Pennsylvania

State University Chapter of Iota Sigma Pi. Arthur Williams Memorial Award of the American Museum of Safety.

Burgess Memorial Award of the American Society of Metals. Albert Victor Bleininger Award of the American Ceramic Society, Pitts- burgh Section. Harry Diamond Memorial Award for 1959 of the Institute Engineers.

1959 Fisher Award in Analytical Chemistry of the American

Society.

Alumni Achievement Award from Westminister College.

Fellowship grant from the National Science Foundation.

Arthur S. Flemming Award of the Junior Chamber

Washington, D.C.

Elected Honorary Member of the Optical Society of America.

of Radio

Chemical

of Commerce of

1958 Callahan Gold Medal of the Ohio State Dental Association. Henry C. Turner Medal of the American Concrete Institute. Honorary Life Membership in the American Society for Testing

Materials. Elected a Distinguished Member of the Society of Plastics Engineers.

Award of Merit of the American Society for Testing Materials. 1959 Award of the Spectroscopy Society of Pittsburgh.

Honorary Membership in the Southern Weights and Measures Association. Fellowship grant from Netherlands Government.

Elected President of the Washington Rubber Group.

Award of Merit from the St. Louis Dental Society.

Fellowship grant from the John Simon Guggenheim Memorial Foundation.

Elected a Director of the Illuminating Engineering Society.

DEPARTMENT OF COMMERCE EXCEPTIONAL SERVICE AWARDS

RECIPIENT

Bender, Peter L. Driscoll, Raymond L. McPherson, Archibald T. Rhodes, Ida Wait, James R.

TECHNICAL AREA

Atomic standards of frequency.

Determination of atomic constants, Leadership in calibration, testing, and specifications research. Design and application of digital computing equipment.

Authorship in the field of radio wave propagation.

Infrasonics Group: Development of defense instrumentation.

Brown, Robert F., Jr. Chrzanowski, Peter

Cordero, Fidel

Frey, Hilbert W.

Goerke, Vernon H.

Johnson, Daniel P. Levine, Irving

Matheson, Harry

143
DEPARTMENT OF COMMERCE MERITORIOUS SERVICE AWARDS

RECIPIENT TECHNICAL AREA

Bell, Rosemond K.

Blaine, Raymond L. Bohn, Richard A. Dalzell, Harry P. Falkinburc, Francis C. Frush, Harriet L. Heaton, Vincent E. Hobbs, Robert B. Howard, Paul T. Jean, A. Glenn

Kemper, John A. Motz, Joseph W.

Parfitt, Isabelle C. Scheirer, Charles E. Stansbury, Carroll

Chemical analysis of metals and alloys.

Science and technology of Portland cement. Cement testing. Initiation and promotion of safety program.

Calibration of force measuring devices. Chemistry of carbohydrates.

Maintenance of U.S. primary standard of frequency.

Science and technology of leather and paper.

Specifications for organic coatings.

Radio propagation measurements. Radio propagation measurements.

X-ray cross section and polarization research. Administrative duties. Cement testing.

Electronic and electromechanical equipment development.

North Atlantic Radio International Geophysical Year world warning service. Warning Service

:

Bender, Norbert

Boccs, Kent D.

Jones, Lawrence A. Moore, Roger C. Pritting, John W.

Sullivan, John L.. Jr. Weldon, James M.

Wiewara, Edward J.

The Bureau sponsors a broad Employee Development Program oriented

to the education and training needs of all staff members. Primary program

objectives are increasing efficiency in the conduct of official, assigned duties,

and systematic preparation for increased responsibilities. This program is

implemented through two major educational media: The NBS Graduate

School, and training through non-Government facilities. The program covers educational levels up through postdoctoral research and includes general

staff development courses. The curriculum of the Bureau's Graduate School, with an average of 40

courses a year, includes graduate and undergraduate courses in the physical

sciences, mathematics, and certain branches of engineering; and a series of

scientific colloquia and seminars led by research leaders from the Bureau

staff and from other research centers in this country and abroad. Educational counseling and a program of thesis accreditation are also provided.

A series of general staff development courses is also offered through the

Graduate School. Typical examples in this category are scientific shorthand, mathematical symbolism and terminology, and practical metallurgy.

The Graduate School curriculum is divided into courses classed as NBS

out-of-hours, NBS in-hours, and NBS university-sponsored out-of-hours.

Course offerings, based on periodic need surveys, are determined by the

NBS Educational Committee. The program is flexible to meet the varied

and changing needs of the staff. Since the establishment of the Graduate

School in 1908, more than 14,500 registrations have been recorded, and more

than 260 graduate degrees have been awarded by 40 different universities,

partly on the basis of credits obtained, or thesis work carried on, through

the Graduate School. During the past year, there were 1,400 registrations

in 78 courses offered at the Washington and Boulder Laboratories.

3.6. Education and Training Program

144
The Bureau sponsors three major training programs through non-government facilities under authority of the Government Employees' Training Act

of 1958. These are:

1. Full-time (3-12 months) postdoctoral study and research assignments at universities and research centers, both in this country

and abroad.

2. Full-time (less than 3 months) attendance at institutes, seminars,

short concentrated courses, workshops, etc. Generally, these are

offered through the educational facilities of major universities and

industrial laboratories throughout the country.

3. Part-time, job-related, academic courses at local educational institutions, generally in early evening classes.

Approximately 190 staff members were trained through non-Government

facilities in 1959. Ten selected career scientists were sent on full-time re- search assignments to universities and research centers. Thirty staff members, primarily scientists and subprofessional laboratory personnel, attended

short concentrated courses and training programs at universities and in industry. In addition, 150 employees, mostly from technical divisions, at- tended job-related courses at local educational facilities. Participants' full

salaries and expenses in non-Government training programs were paid by

the Bureau. These included tuition, related fees, travel, and per diem, as

well as transportation of family and household effects for full-time, longterm training.

An annual summer student trainee program at the Bureau is open to college students majoring in the physical sciences, mathematics, and certain

branches of engineering. This activity is an integrated work-study program

including lectures, tours, demonstrations, supervised laboratory assignments,

and professional counseling. The program has the twofold purpose of

acquainting young people with career opportunities in scientific research at

NBS and preparing select students for such careers. The 1959 summer

student program had an enrollment of 160 students, with 69 new students,

and 91 returnees from previous summers. The new group included 13 outstanding high school students who had obtained recognition through the

Westinghouse Science Talent Search or other national science competition.

Approximately 40 percent of the 1959 total enrollment were graduate students who returned to school in September to undertake advanced study programs. The 1959 student group represented 46 colleges and universities

from a wide geographical area. In collaboration with the National Research Council, the Graduate School

offers postdoctoral resident research associateships to young scientific investigators of unusual ability and promise of becoming creative leaders in

basic research. Associates are given an opportunity for advanced training

in basic research in the various branches of the physical and mathematical

sciences. While acquiring basic knowledge, they have opportunities for

developing new scientific approaches and laboratory skills, thus advancing

145
scientific knowledge. Associateships, which are limited to 20 at any one

time, are tenable at both the Washington and Boulder Laboratories.

The Bureau's educational program also includes weekly Scientific Staff

Meetings which run from September through May. Of less specialized nature than colloquia and seminars offered in the Graduate School, the Scientific Staff Meetings are open to all members of the professional staff at the

Bureau and are also regularly attended by scientific personnel from neighboring laboratories. Designed to keep Bureau personnel abreast of current

developments in the various fields, these lectures are given by members of

the staff and by scientists from universities and other laboratories in the

United States and abroad. Lectures by members of the Bureau staff include

a yearly report to the staff by the Director, lectures on current research of

broad general interest to other members of the staff, reports by staff members

on international meetings, and reports from fellowship scientists on research

work at other institutions in this country and abroad. About two-thirds of

the program is devoted to lectures by guest scientists.

3.7. Cooperative Research With Industry

The Bureau's Research Associate Plan, a cooperative program with

American industry, has resulted in many significant developments in science

and technology. Under this plan, technical, industrial, and commercial

organizations can support work at the Bureau on projects that are of special

interest to them, yet are of sufficient general interest to justify use of government facilities. These projects must also be important from the standpoint of the Nation's sum total of technological knowledge. Supporting

industries donate both funds and personnel for the projects. At the present

time 12 groups are supporting research associates at NBS in the following

areas

:

Sponsor Field of Activity

American Dental Association Dental research.

American Electroplaters Society Porosity and corrosion of electroplated

surfaces.

American Society for Testing Materials Cement reference laboratory.

American Society for Testing Materials Completion of spectral data.

Asphalt Roofing Industry Bureau Asphalt roofing research.

Bone Char Research Project, Inc Studies of adsorption and adsorbents.

Calcium Chloride Association Hydration of portland cement.

NBS-Joint Committee on Chemical Analysis Standard X-ray diffraction powder

by Powder Diffraction Methods: ASTM, patterns.

American Crystallographic Assoc., Institute of

Physics (British), National Assoc. of Corrosion Engineers.

National Research Council Masonry research.

Porcelain Enamel Institute Development of standard tests. Portland Cement Association Basic research in physical chemistry

related to portland cement.

146
An important and similar area of cooperation between the Bureau and

industry is the program authorized in 1950 by Public Law 619 under which

the Bureau is authorized to accept funds for the purpose of furthering its

work. This arrangement permits individuals as well as technical, industrial,

and commercial organizations to support work at the Bureau when the

results are expected to be of value to the general public.

During the past year 18 projects were supported by gifts from 32 or- ganizations as follows:

Gift-Supported Projects

Donor Field of Activity

American Iron and Steel Institute Standard samples of ferrous metals,

steel research.

American Iron and Steel Institute Bond tests on high yield point reinforcing bars.

American Petroleum Institute Metal-organic analytical standards.

Brown and Sharpe Manufacturing Company Precision Gage Block Program.

Carnegie Institute Telescope image tubes.

CBS Television Television Field Strength Studies.

Corrosion Research Council of the Engineering Reactions at Metal Surfaces and Stress

Foundation. Corrosion.

Dearborn Gage Company Precision Gage Block Program.

Do-AU Company Precision Gage Block Program.

E. I. du Pont de Nemours & Company, Inc , Precision Gage Block Program.

Edward Orton Ceramic Foundation Research in clays.

Expanded Shale Clay and Slate Institute Creep and Shrinkage of Concrete Containing Expanded Shale Aggregate.

Fonda Gage Company, Inc . Precision Gage Block Program.

General Electric Company Precision Gage Block Program.

Georgetown University Physiological Research.

Greenfield Tap and Die Corporation Precision Gage Block Program.

Hughes Aircraft Precision Gage Block Program.

IBM Corporation Precision Gage Block Program.

Illuminating Engineering Research Institute Programing computers for calculating

the chromaticity coordinates with

lamps having line spectra.

International Nickel Company Effect of Nickel on Thermal Conductivity of Steel.

Link Aviation, Inc Precision Gage Block Program.

National Lime Association Hydration of Lime.

New Departure, GMC * Precision Gage Block Program.

Pratt and Whitney Company Precision Gage Block Program.

The Sheffield Corporation . Precision Gage Block Program.

Sugar Research Council Indices of Solutions of Invert Sugars.

Taft-Peirce Foundation Precision Gage Block Program.

Technical Association of the Pulp and Paper Relationship and Sensitivity of Air

Industry. Leak Smoothness Testers.

Timken Roller Bearing Company Precision Gage Block Program.

UNESCO Ionization chamber.

The Van Keuren Company Precision Gage Block Program.

Welding Research Council of the Engineering Stress-corrosion cracking of stainless

Foundation. steel. Anonymous „ Phenomena of crystallization.

147
3.8. Publications*

Publications in the Bureau's Series

Journal of Research. Complete scientific reports of the Bureau's research and development, both experimental and theoretical, in physics, chemistry, engineering, and mathematics, and the results of test and instrumentation activities in these fields are printed

in the Journal. (The papers listed below complete the monthly Journal of Research

ending June 1959. The Journal of Research is now issued in four sections; for additional

information, see p. 15 and inside back cover.)

Volume 61, July—December 1958

2877. The system lime-alumina-water at 1° C. Elmer T. Carlson.

2878. Heat content of zirconium and of five compositions of zirconium hydride from 0°

to 900° C. Thomas B. Douglas and Andrew C. Victor.

2879. Uniform transient error. Edith L. R. Corliss.

2880. Optical T-bench method of measuring longitudinal spherical aberration. Francis

E. Washer.

2881. Mass spectrometric study of the rate of thermal decomposition of hydrazoic acid.

J. L. Franklin, Vernon H. Dibeler, and Preston P. Morris, Jr. 2882. Erosion damage to solids caused by high-speed collision with rain. Olive G. Engel.

2883. Emission spectrum of carbon monoxide from 2.3 to 2.5 microns. Earle K. Plyler,

Harry C. Allen, Jr., and Eugene D. Tidwell.

2884. Further studies on the influence of a ridge on the low-frequency ground wave. James R. Wait and Anabeth Murphy.

2885. Infrared studies of polymorphs of silicon dioxide and germanium dioxide. Ellis

R. Lippincott, Alvin Van Valkinburg, Charles E. Weir, and Elmer N. Bunting.

2886. Carbon-14 carboxy-labeled polysaccharides. Joseph D. Moyer and Horace S.

Isbell.

2887. Heat of formation of sodium calcium aluminate. Edwin S. Newman.

2888. Thermal degradation of polyacrylonitrile, polybutadiene, and copolymers of butadiene with acrylonitrile and styrene. Sidney Straus and Samuel L. Madorsky.

2889. On the motion of two cylinders in an ideal fluid. Lloyd H. Carpenter.

2890. Properties of sodium titanium silicate glasses. Edgar H. Hamilton and Given W.

Cleek.

2891. Wavelengths from thorium-halide lamps. William F. Meggers and Robert W.

Stanley.

2892. An electrical-analog method for transient heat-flow analysis. A. F. Robertson and

Daniel Gross.

2893. Effect of crystal field and spin-orbit coupling on magnetic susceptibility of systems

with f electron configuration. Charles M. Herzfeld and Daniel B. Levine.

2894. Vibration-rotation bands of ammonia: 1. The combination bands v2-\- (vi,vz) . William S. Benedict, Earle K. Plyler, and Eugene D. Tidwell.

2895. Evaluation of tensile, compression, torsional, transverse, and impact tests and

correlation of results for brittle cermets. Matthew J. Kerper, Lewis E. Mong, Maurice

B. Stiefel, and Sylvanus F. Holley.

2896. Redetermination of mass spectra of deuteromefhanes. Fred L. Mohler, Vernon

H. Dibeler, and Edith Quinn.

2897. Effect of strain-temperature history on the tensile behavior of titanium and a titanium alloy. Glenn W. Geil and Nesbit L. Carwile.

2898. Propagation of very-low-frequency pulses to great distances. James R. Wait.

2899. Transmission and reflection of electromagnetic waves in the presence of stratified

media. James R. Wait.

2900. Pseudoternary system calcium oxide-monocalcium aluminate (CaO AI2O3) -dicalcium ferrite (2CaO Fe2 03 ) . Terry F. Newkirk and R. D. Thwaite.

2901. Heats of formation of diborane and pentaborane. Edward J. Prosen, Walter H.

Johnson, and Florence Y. Pergiel.

2902. Temperature of the inversion in cristobalite. Raymond F. Walker, Samuel Zerfoss, Sylvanus F. Holley, and Lucy J. Gross.

2903. Infrared emission spectra of flames under high resolution. Earle K. Plyler, and

Eugene D. Tidwell.

2904. Improved description of hafnium spectra. Charles H. Corliss and William F.

Megeers.

2905. Dielectric constant of hydrogen-bonded liquids. Floyd Buckley.

2906. On the diffraction and reflection of waves and pulses by wedges and corners.

F. Oberhettinger.

Publications in these series are available, unless otherwise indicated, from the Superintendent of Documents, Washington 25, D.C. 148
2907. A liquid-helium cold cell for use with an X-ray diffractometer. Igor A. Black,

Leonard H. Bolz, Frank P. Brooks, Floyd A. Mauer, and H. Steffen Peiser.

2908. The second spectrum of ruthenium (Ru n). Allen G. Shenstone and William F. Meggers.

2909. Self-ignition temperatures of materials from kinetic-reaction data. Daniel Gross

and A. F. Robertson.

2910. Some studies of atmospheric transmittance on Mauna Loa. Ralph Stair and

Russell G. Johnston.

2911. Central notations for the revised ISCC-NBS color-name blocks. Kenneth L. Kelly.

2912. Viscosity of n-hexadecane. Robert C. Hardy.

2913. Revision of the phase equilibrium diagram of the binary system calcia-titania,

showing the compound Ca4Ti3Oio. Robert S. Roth.

2914. Term analysis of the second spectrum of rhenium (Re ii) . William F. Meggers,

Miguel A. Catalan, and Manuel Sales.

2915. Density formula for alkali silicate glasses from annealing to glass-processing

temperatures. Leroy W. Tilton. i 2916. Thermodynamic properties of gases at high temperature: 1. 'Chemical equilibrium

among molecules, atoms, and atomic ions considered as clusters. Harold W. Woolley.

2917. Parallel testing interferometer. James B. Saunders.

2918. Correction for instrumental drift in flame photometry. Barry W. Mulligan and

Alan F. Haught.

2919. Mechanism of stress-corrosion cracking in the AZ31B magnesium alloy. Hugh

L. Logan.

2920. Evaluation of lens distortion by visual and photographic methods. Francis E.

Washer, William P. Tayman, and Walter R. Darling.

Volume 62, January-June 1959

2921. Heat of mixing of polybutadiene and benzene. Ralph S. Jessup.

2922. Infrared high resolution grating spectrometer. Earle K. Plyler and Lamdin R.

Blaine.

2923. Determination of titanium, zirconium, nobium, and tantalum in steels: Separations by anion-exchange. John L. Hague and Lawrence A. Machlan.

2924. Preparation of new solution standards of radium. W. B. Mann, L. L. Stockmann,

W. J. Youden, A. Schwebel, P. A. Mullen, and S. B. Garfinkel.

2925. Phase equilibrium relations in the binary system lead oxide-niobium pentoxide.

Robert S. Roth.

2926. Mass spectra of some deuterostyrenes. Edith I. Quinn and Fred L. Mohler.

2927. Heat of reaction of diborane with water and the heat of formation of boric oxide.

Edward J. Prosen, Walter H. Johnson, and Florence Y. Pergiel.

2928. Heat of formation of titanium tetrachloride. Walter H. Johnson, Raymond A.

Nelson, and Edward J. Prosen.

2929. Determination of niobium and tantalum in titanium-base alloys. John L. Hague

and Lawrence A. Machlan.

2930. Properties of zinc borosilicate glasses. Edgar H. Hamilton, Roy M. Waxier, and

Joseph M. Nivert, Jr. 2931. Design and performance of a block-type osmometer. Donald Mclntyre, G. C.

Doderer, and James H. O'Mara.

2932. Heat of formation of titanium tetrabromide. Raymond A. Nelson, Walter H.

Johnson, and Edward J. Prosen.

2933. Adsorption of polyesters on glass, silica, and alumina. Robert R. Stromberg,

Alan R. Quasius, Samuel D. Toner, and Midgett S. Parker.

2934. Theory of the effect of drag on the orbital inclination of an earth satellite. John

P. Vinti.

2935. On a theorem of M. Riesz. Martin Pearl.

2936. Refinement of the crystal structure of triclinic magnesium pyroborate. Stanley

Block, Gordon Burley, Alvin Perloff, and Robert D. Mason, Jr. 2937. Heat transfer in laminar flow through a tube. Milton Abramowitz, William F.

Cahill, and Clarence Wade, Jr. 2938. Fluorination of haloaromatic compounds. Roland E. Florin, Walter J. Pummer,

and Leo A. Wall.

2939. Synthesis of some disubstituted 3,4,5,6-tetrafluorobenzenes. Walter J. Pummer,

Roland E. Florin, and Leo A. Wall.

2940. Reactions of aromatic fluorocarbons with hydrogen. Roland E. Florin, Walter J. Pummer, and Leo A. Wall.

f- 2941. Exponential integral I e~ xtt~ n dt for large values of n. Walter Gautschi.

149
2942. Effect of oxygen on the bonding of gold to fused silica. D. G. Moore and H. R.

Thornton.

2943. Interferometer for large surfaces. James B. Saunders and Franz L. Gross.

2944. Glass formation in polymers: II. The systerm rubber-sulfur. Gordon M. Martin

and Leo Mandelkern.

2945. Elastic deformations in strips with holes loaded through pins. Michael Chi and

L. K. Irwin.

2946. Absolute light-scattering photometer: I. Design and operation. Donald McIntyre and G. C. Doderer.

2947. Resolution of the dissociation constants of d, I -malic acid from 0° to 50° C. Murray Eden and Roger G. Bates.

2948. Capacity requirement of a mail sorting device. B. K. Bender and A. J. Goldman.

2949. Effect of internal radiant heat transfer on temperature distribution, thermal stress,

and deflection in box beams. Stanley Goodman, Stanton B. Russell, and Charles

E. Noble.

2950. Mean absolute value and standard deviation of the phase of a constant vector plus

a Rayleigh-distributed vector. J. Ralph Johler and Lillie C. Walters.

2951. A simple rotating molecular still. Gaylon S. Ross and Lois J. Frolen.

2952. Scintillation counter method of intercomparing neutron source strengths by means

of a manganous sulfate bath. Earl R. Mosburg, Jr. 2953. Phase equilibria in the subsystem barium disilicate—dibarium trislicate. Robert

S. Roth and Ernest M. Levin.

2954. Separation and determination of phosphate, silicate, and arsenate. W. Stanley

Clabaugh and Audrey Jackson.

2955. Heat of formation of potassium calcium silicate. Edwin S. Newman.

2956. Heat of formation of boron trichloride. Walter H. Johnson, Richard G. Miller,

and Edward J. Prosen.

2957. Thermal degradation of polymers at low rates. Samuel L. Madorsky.

2958. Pits in metals caused by collision with liquid drops and soft metal spheres. Olive

G. Engel.

2959. Earth currents near a monopole antenna with symmetrical top loading. James

R. Wait.

2960. Infrared absorption spectra of some cyclic acetals of sugars. R. Stuart Tipson,

Horace S. Isbell, and James E. Stewart.

2961. Earth currents near a top-loaded monopole antenna with special regard to electrically small L- and T-antennas. H. Lottrup Knudsen.

Technical News Bulletin. This monthly publication summarized the current research

development, and test activities of the Bureau. The articles are brief, with emphasis on the results of research and their significance, chosen for their importance to other

scientists, engineers, and to industry. Resumes of longer research reports, important

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has represented the Nation, and a bibliography of all publications by members of the

staff as published are included. The Bulletin is designed to give a succinct account

of the current work of the Bureau. (Annual subscription: domestic, $1.50; foreign,

$2.25.)

Basic Radio Propagation Predictions. This is a monthly publication for those con- cerned with radio communication in determining the best skywave frequencies over any

path at any time of day for average conditions for the month of prediction, which are made 3 months in advance. Charts of extraordinary-wave critical frequency for the

F2 layer and of maximum usable frequency for a transmission distance of 4,000 km, of

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Circulars. Circulars are compilations of information on various subjects related to the Bureau's scientific, technical, and engineering activities. Thev inlude not only the

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440. Supplement. Viscosities of sucrose solutions at various temperatures: Tables of

Recalculated Values. J. F. Swindells, C. F. Snyder, R. C. Hardy, and P. E. Golden.

5 cents. 539. Volume 8. Standard X-ray diffraction powder patterns. Howard E. Swanson,

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30 cents. 150
589. Tables of dielectric dispersion data for pure liquids and dilute solutions. Floyd

Buckley and Arthur A. Maryott. 50 cents.

7 rrv William M. Rogers and Robert

o(e z -l) 2

596. Single-phase transfer of liquefied gases. Robert B. Jacobs. 30 cents.

597. Energy spectrum resulting from electron slowing down. Rosemary T. McGinnies.

20 cents. 598. Techniques for accurate measurement of antenna gain. H. V. Cottony. 15 cents.

599. On the theory of fading properties of a fluctuating signal imposed on a constant

signal. H. Bremmer. 25 cents.

600. Calibration of liquid-in-glass thermometers. James F. Swindells. 20 cents. 602. Testing of glass volumetric apparatus. J. C. Hughes. 20 cents.

603. Stark broadening functions for the hydrogen lines. Anne B. Underhill and John

H. Waddell. 65 cents. Miscellaneous Publications. As the name implies, this series includes material,

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224. Hydraulic research in the United States, 1958. Helen K. Middleton. $1.25.

225. Report of the 43d National Conference on Weights and Measures, 1958. 65 cents.

226. Research highlights of the National Bureau of Standards. Annual report, 1958.

45 cents. Handbooks. These are recommended codes of engineering and industrial practice,

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67. Checking prepackaged commodities. A manual for weights and measures officials,

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56. Tables of osculatory interpolation coefficients. H. E. Salzer. 30 cents. Building Materials and Structures Reports. This series reports the results of work at the National Bureau of Standards in the field of building research. The objective is to provide the Government, the interested professions, and the building industry with

technical data useful in the preparation of building codes, standards, and engineering

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140—3d Edition. Selected bibliography on building construction and maintenance.

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152. Wind pressures in various areas of the United States. Guttorm N. Brekke. 15 cents. Technical Notes. The Technical Note Series is designed to supplement the Bureau's

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7. Low- and very low-radiofrequency tables of ground wave parameters for the spherical

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151
Publications in Outside Journals

Agy, V., Results of ionospheric drift measurements in the United States, p. 23, and

Polar blackout occurrence patterns, p. 129, J. Atmospheric and Terrest. Phys. Special

Supp., Proc. Polar Atmosphere Symp., Oslo, Norway, July 1956, Pt. II (1957).

Albrite, J. P., Shutts, R. E., Whitlock, M. B., Jr., Cook, R. K., Corliss, E. L. R., and

Burkhard, M.D., Research in normal threshold of hearing, A.M.A. Arch. Otolaryngol.

68, 194 (1958).

Alexander, S. N., Automation and future management information systems, Proc. 4th

Military-Industry Packaging and Handling Symp., Navy Department September 30^

October 2, 1958, p. 23 (Washington, D.C.) (1958)

.

Alexander, S. N., Future developments of electronic data processing systems, Proc. 8th

Annual Symp. Federal Govt. Accountants Assoc., November 17-18, 1958, The Federal

Accountant, VIII, No. 4, 28 ( 1959)

.

Ambler, E., Hayward, R. W., Hoppes, D. D., and Hudson, R. P., Beta-gamma correlations from polarized nuclei, Proc. Congres International de Physique Nucleaire, 1958,

Interactions Faibles, Chapter III, p. 831 (Paris, France, 1959).

Ambler, E., Hayward, R. W., Hoppes, D. D., Hudson, R. P., Experiments on the betadecay of polarized nuclei, Proc. Kamerlingh Onnes Conference, Leiden, Holland,

1958, Physica 24 (Supplement) , 564 (1958)

.

Ambler, E., and Hudson, R. P., Magnitoye okhlazhdenye, Uzpekhi Physicheskhikh

Nauk 47, 445 (1959).

Amdur, I., and Ross, J., On the calculation of properties of gases of elevated temperatures, Combustion and Flames 2, 412 (1958)

.

Antosiewicz, H., A survey of Lyapunov's second method, Contributions to the Theory

of Nonlinear Oscillations, Volume IV, Edited by S. Lefshetz, p. 141. Annals of

Math. Studies No. 41 (Princeton University Press, Princeton, N.J., (1958).

Armstrong, G. T., Wong, P. K., and Krieger, L. A., Use of a direct current amplifier

and recorder to balance a Mueller resistance bridge, Rev. Sci. Instr. 30, 339 (1959).

Arnett, R. W., Mullen, L. O., and Warren, K. A., Some methods for reducing heat leak

through support members in liquefied gas storage vessels, Proc. 1958 Cryogenic

Engineering Conference, Paper G—1, p. 410. Edited by K. D. Timmerhaus, Chemical

Engineering Dept. (University of Colorado, Boulder, Colo., 1959)

.

Astin, A. V., Instrumentation— where we stand, ASTM Bull. No. 232, 7 (1958).

Astin, A. V., Precise measurement and race for technological supremacy, Mag. of

Standards 29, No. 2, 36 ( 1958)

.

Astin, A. V., Research is everybody's business, Tappi 41, No. 5, [A] 14 (1958).

Astin, A. V., Standards and measurements for electronics, I.R.E. Trans, on Instrumentation 1-7, No. 3-4, 134 (1958).

Astin, A. V., Systematic research, Ordnance 43, No. 233, 741 (1959)

.

Athay, R. G., and Thomas, R. N., On the use of the early Balmer lines to extend the

photospheric model, Astrophys. J. 127, No. 1, 96 (1958)

.

Aumann, R. J., and Kruskal, J. B., The coefficients in an allocation problem, Naval Research Logistics Quart. 5, 111 (1958).

Bailey, D. K., The effect of echo on the operation of high frequency communication

circuits, I.R.E. Trans, on Ant. and Prop. AP-6, 325 (1958).

Bain, K., Faegre, M. L., and Wyly, R. S., Behavior of young children under conditions

simulating entrapment in refrigerators, Pediatrics 22, No. 4, Pt. I, 628 (1958).

Ballard, D. B., and Bennett, J. A., A magnetic specimen mount for fractography, Metal

Prog. 74, No. 5, 114 (1958).

Barbrow, L. E., and Wilson, S. W„ Vertical distribution of light from gas-filled candlepower standards, Ilium. Eng. 53, 645 (1958)

.

Barsis, A. P., and Capps, F. M., Effect of super-refractive layers on tropospheric signal

characteristics in the Pacific coast region, I.R.E. Wescon Convention Record, 1957,

Microwaves, Ant. and Prop. I, 116 (1958)

.

Bass, A. M., and Broida, H. P., Spectra emitted from solid nitrogen condensed at 4.2° K

from a gas discharge, Phys. Rev. 101, No. 6, 1740 (1956)

.

Bateman, R., Finney, J. W., Smith, E. K., Tveten, L. H., and Watts, J. M., IGY observations of F-layer scatter in the far east, J. Geophys. Research 64, 403 (1959).

Bates, R. G., and Wichers, E., Precise intercomparison of acids by differential potentiometric titration with the hydrogen electrode. Actas Do Congress (Lisboa, Portugal)

1, 3 (1957).

Bay, Z., and Newman, P. A., Comparison of the ionization produced in air by alpha

particles near 5-Mev and by beta particles, Bull. Am. Phys. So. 11:4, No. 4, 217 (1959).

Bay, Z., and Seliger, H. H., Absolute measurement of Wa ir for polonium-210 alpha

particles, Radiation Research 9, No. 1, 90 (1958)

.

For completeness, a few references to publications issued previous to July 1957 are included.

152
Bazley, N. W., Montroll, E. W., Rubin, R. J., and Shuler, K. E., Studies in nonequilibrium

rate processes. III. The vibrational relaxation of a system of anharmonic oscillators,

Errata in J. Chem. Phys. 29, No. 5, 1185 ( 1958)

.

Bean, B. R., First meeting on radio climatology, Proc. I.R.E. Letter 46, 1425 (1958).

Bean, B. R., The atmospheric bending of radio waves (Abstract), Congres International

sur la Propagation des Ondes Radio-Electriques, October 6-11, 1958 (Liege, Belgium)

(1958).

Bean, B. R., Utilizzazione delle osservazioni meteorologiche correnti nella propagation

radio-elettrica, Post e telecomun. 25, 1120 ( 1957)

.

Bean, B. R., and Thayer, G. D., On models of the atmospheric radio refractive index,

Proc. I.R.E. 47, No. 5, 740 ( 1959 )

.

Beatty, R. W., and Kerns, D. M., Recently developed microwave impedance standards

and methods of measurement, I.R.E. Trans, on Instrumentation 1-7, No. 3-4, 319

(1958).

Beaty, E. C, and Bender, P. L., Narrow hyperfine absorption lines of Cs 133 in various

buffer gases, Phys. Rev. 112, No. 2, 450 ( 1958 )

.

Becker, J. H., On the quality of gray tin crystals and their rate of growth, J. Appl.

Phys. 29, No. 7, 1110 (1958).

Bekkedahl, N., and Seaman, R. G., The ASTM crude natural rubber subcommittee,

Rubber World 189, 693 ( 1959)

.

Bender, P. L., Beatty, E. C., and Chi, A. R., Optical detection of narrow Rb87 hyperfine

absorption lines, Phys. Rev. Letters 1, No. 9, 331 (1958)

.

Bender, P. L., and Driscoll, R. L., A free precession determination of the proton gyromagnetic ratio, I.R.E. Trans, on Instrumentation 1-7, 176 (1958).

Benedict, W. S., Plyler, E. K., and Tidwell, E. D., Vibration-rotation bands of ammonia.

III. The region 3.2 to 4.3 microns, J. Chem. Phys. 29, No. 4, 829 (1958).

Bennett, J. A., and Weinberg, J. G., A toric bending specimen for investigation of geometrical factors in fatigue, ASTM Bull. No. 234, 53 ( 1958)

.

Berger, M. J., Hubbell, J., and Reingold, I., Contribution of the annihilation radiation

to the gamma-ray flux in lead, Phys. Rev. 113, No. 3, 857 (1959).

Berger, M. J., and Spencer, L. V., General relations between fluxes from collimated point

and plane sources of radiation, Phys. Rev. 113, No. 2, 408 (1959).

Berger, M. J., and Spencer, L. V., Some radiological applications of gamma-ray trans- port theory, Radiation Research 10, No. 5, 552 (1959).

Berman, H. A., An improved 8-hydroxyquinoline method for the determination of magnesium oxide in portland cement, ASTM Bull. No. 237, 51 ( 1959)

.

Bersch, C. F., Stromberg, R. R., and Achhammer, B. G., Structural changes in irradiated

plastics films, SPE Tech. Papers 5, 5 (1959)

.

Bestul, A. B., Variations of surface tension with body and surface concentration, J. Am. Ceram. Soc. 42, 236 (1959).

Bestul, A. B., Shartsis, L., and Shermer, H. F., Immiscibility and surface tension of

some simple borates, J. Am. Ceram. Soc. 41, 507 (1958)

.

Birnbaum, G., and Maryott, A. A., Nonresonant absorption of symmetric top molecules,

J. Chem. Phys. 29, 1422 (1958)

.

Bloss, R. L., A facility for the evaluation of resistance strain gages at elevated temperatures, Am. Soc. Testing Materials Spec. Tech. Pub. No. 230, 57 (1958).

Boltz, L. H., Boyd, M. E., Mauer, F. A., and Peiser, H. S., A reexamination of the

crystal structure of a and (3 nitrogen, Acta Cryst. 12, 237 (1959)

.

Boltz, L. H., Mauer, F. A., and Peiser, H. S., Low-temperature X-ray studies on Rice's

blue material, J. Chem. Phys. 30, No. 1, 349 ( 1959)

.

Bouche, R. R., and Tate, D. R., Autographic stress-strain recorders, ASTM Bull. No.

228,33 (1958).

Bowles, K. L., Observation of vertical-incidence scatter from the ionosphere at 41

Mc/sec, Phys. Rev. Letters 1, No. 12, 454 (1958).

Branscomb, L. M., Calculated calibration points for negative ion appearance potentials,

J. Chem. Phys. 29, No. 2, 452 (1958).

Branscomb, L. M., The electron affinity of atomic oxygen, Nature 182, 248 (1958).

Branscomb, L. M.. Burch, D. S., Smith, S. J., and Geltman, S., Photodetachment cross

section and the electron affinity of atomic oxygen, Phys. Rev. Ill, No. 2, 504 (1958).

Branscomb, L. M., and Pagel, B. E. F., Atomic and molecular negative ions in stellar

atmospheres, Monthly Notices Roy. Astron. Soc. 118, No. 3, 258 (1958).

Brauer, E. M., White, E. E., Jr., and Moshanos, M. G., The reaction of metal oxides

with o-ethyoxybenzoic acid and other chelating agents, J. Dental Research 37, 547

(1958).

Breckenridge, F. C, Fifty years of signal lighting, Brochure issued by the Ilium. Eng.

Soc. 21 pages (1959).

Brenner, A., Electrolysis of organic solvents with reference to the electrodeposition of

metals, J. Electrochem. Soc. 106, 148 (1959)

.

153
Brenner, A., Research in plating at National Bureau of Standards, Plating Management

3, No. 5, 14 (1958).

Brodd, R. J., On the hydrogen evolution reactions, J. Electorchem. Soc. 106, No 1 74 (1959).

Brode, W. R., and Hilbert, G. E., Career opportunities in the Government, Chem

Eng. News 36, Pt. II, 70 ( 1958)

.

Broida, H. P., Trapped radicals, Endeavor 17, 208 (1958)

.

Broida, H. P., and Chapman, M. W., Stable nitrogen isotope analysis by optical spectroscopy, Anal. Chem. 30, 2049 (1958)

.

Broida, H. P., and Peyron, M., Evaporation of active species trapped in a solid con- densed from discharged nitrogen, J. Chem. Phys. 28, 725 (1958).

Broida, H. P., and Peyron, M., Luminescence of solid nitrogen (4.2° K) containing

atoms of free radicals. Effect of traces of oxygen, hydrogen and water vapor, J. Phys.

Radium 19, No. 4, 480 (1958)

.

Broida, H. P., and Shuler, K. E., Spectroscopic study of electronic flame temperatures

and energy distributions, Rev. French Inst. Petro. and Ann. Combus. Liquid 13,

620 (1958).

Brown, D. W., and Wall, L. A., Pyrolysis of poly-alpha-methylstyrene, J. Phys. Chem.

62, 848 (1958).

Brown, E. H., and Brennand, J. R., Jr., Magnetic losses at low temperatures, Proc.

1958 Cryogenic Engineering Conference, Paper A-5, p. 65. Edited by K. D. Timmerhaus, Chemical Engineering Dept. (University of Colorado, Boulder, Colo., 1959) ; J. Appl. Phys. 30, No. 1, 112 (1959)

.

Brown, F. P., A delegate reports on small tools, Mag. of Standards 29, No. 8, 235 (1958)

.

Brown, F. W., Demands on teachers in a technological society, Colorado School J. 14

(1958).

Brown, F. W., Radio propagation research at the National Bureau of Standards, Am.

J. Phys. 26, 628 (1958).

Bunting, E. N., and Van Valkenburg, A., Some properties of diamond, Am. Mineralogist

43,102(1958).

Burch, D. S., Smith, S. J., and Branscomb, L. M., Photodetachment of Oj, Phys. Rev.

112, 171 (1958).

Burgers, J. M., and Thomas, R. N., Preface to Proc. 3d Symp. on Cosmical Gas Dynamics

(Smithsonian Astrophysical Observatory, June 1957, Cambridge, Mass.), Rev. Modern

Phys. 30, 908 (1958).

Carrington, T., Electronic quenching of 0H(22

+

) in flames and its significance in the

interpretation of rotational relaxation, J. Chem. Phys. 30, 1087 (1959).

Carrington, T., and Broida, H. P., Wall effects on rotational population of 0H22

+ in a microwave discharge, J. Mol. Spect. 2, No. 3, 273 (1958).

Cassel, J. M., Degradation of collagen by heat, J. Am. Leather Chemists' Assoc. 53,

507 (1958).

Caswell, R. S., Chin, J., and Mosburg, E. R., Jr., Standards for neutron flux measurement

and neutron dosimetry, Proc. 2d International Conf. on the Peaceful Uses of Atomic

Energy, United Nations (Geneva, Switzerland) 21, 92 (1958).

Chamberlain, J. W., Oxygen red lines in the airglow. I. Twilight and night excitation

processes, Astrophys. J. 127, No. 1, 54 (1958)

.

Chapman, S., The earth and its environment, Proc. I.R.E. 47, No. 2, 137 (1959)

.

Chapman, S., Thermal diffusion in ionized gases, Proc. Phys. Soc. 72, 353 (1958).

Chapman, S., and Davies, K., On the approximate daytime constancy of the absorption

of radio waves in the lower ionosphere, J. Atmospheric and Terrest. Phys. 13, 86

(1958).

Chapman, S. (with aid of Kimball, D. S., Paton, J., Schneider, O., and Thomsen, I. L.),

Visual auroral observations, Annals International Geophys. Year 4, Pt. 1, 41 (1957).

Cohen, R. S., and Bowles, K. L., 50 Mc oblique transmission experiment near the magnetic equator, I.R.E. Trans, on Ant. and Prop. AP-6, 316 (1958)

.

Conner, W. S., Fractional factorial experiments of 2mS

n series, Proc. 14th Annual Clinic

of the Rochester Society for Quality Control, February 18, 1958 (Rochester, N.Y.),

^

p. 59 (1958).

Corliss, E. L. R., Mechanistic aspects of hearing, J. Acoust. Soc. Am. Abstract 31,

841 (1959).

Costrell, L., Radiation monitoring over long-distance telephone lines and direct field lines,

^ I.R.E. Trans, on Nuclear Sci. NS-5, No. 3, 21 ( 1958)

.

Costrell, L., and Brueckmann, R. E., Analysis of millimicrosecond pulses using a chargestorage type pulse-height analyzer, Proc. 2d Symp. on Advances in Fast Pulse Techniques for Nuclear Counting, February 12-13, 1959 (University of California, Berkeley,

^

Calif.).

Costrell, L., and Brueckmann, R. E., Charge-storage pulse-height analyzers for use with

pulsed accelerators, Nuclear Instr. 3, 350 (North-Holland Publishing Co., Amsterdam,

Holland 1958).

154
Cottony, H. V., Elliott, R. S., Jordan, E. C, Rumsey, V. H., Siegel, K. M., Wait, J. R.,

and Woodyard, 0. C, U.S.A. National Committee report, URSI subcommission 6.3,

antennas and waveguides, and annotated bibliography, I.R.E. Trans, on Ant. Prop.

AP-7, No. 1, 87 (1959); Proc. 12th Gen. Assembly, International Scientific Radio

Union, August-September 1957 (Boulder, Colo.), 11, Pt. 6, 121 (1957).

Cottony, H. V., and Wilson, A. C, Gains of finite-size corner-reflector antennas, I.R.E.

^ Trans, on Ant. Prop. AP-6, No. 4, 366 ( 1958)

Couch, D. E., and Senderoff, S., The eletrolytic preparation of molybdenum from fused

salts. V. Electrorefining studies in the presence of tin, iron, copper, silicon, and

nickel, Trans. Metallurgical Soc. of Am. Inst. Metallurgical Engrs., p. 320 (1958).

Couch, D. E., Shapiro, H., and Brenner, A., The use of nickel-aluminum alloy coatings

for the protection of molybdenum from oxidation, J. Electrochem. Soc. 105, No. 8. 485 (1958).

Couch, D. E., Shapiro, H., Taylor, J. K., and Brenner, A., Protection of molybdenum

from oxidation at elevated temperatures, J. Electrochem. Soc. 105, No. 8, 450 (1958).

Coughanour, L. W., Shartsis, L., and Shermer, H. F., Viscosity density, and electrical

resistivity of molten alkaline-earth borate glasses with three mole percent of potassium oxide, J. Am. Ceram. Soc. 41, 324 (1958).

Crichlow, W. Q., Foldes, G., Hewitt, F. J., Horner, F., Shinkawa, H., and Sullivan,

A. W., Annex to recommendation No. 1 on measurement of atmospheric noise, Proc.

12th Gen. Assembly International Scientific Radio Union, August-September 1957

(Boulder, Colo.) , 11, Pt. 4, 102 (1957) ; URSI Info, Bull. No. 105, 13 (1957)

Crow, E. L., A property of additively closed families of distributions, Ann. Math.

Statistics 29, No. 3, 892 ( 1958)

Crow, E. L., The mean deviation of the Poisson distribution, Biometrika 45, 556 (1958).

Culshaw, W., Reflectors for a microwave Fabry-Perot interferometer, I.R.E. Trans, on

^ Microwave Theory and Technique MTT-7, No. 2, 221 (1959)

Curtis, A. J., A survey of some recent advances in polymer physics, and their relation

to dielectric properties, Insulation, p. 15 (1958)

Cuthill, J. R., Richmond, J. C, and Tighe, N. J., The effect of a ceramic coating on

the creep behavior of some high-temperature alloys, Bull. Am. Ceram. Soc. 39, 4

(1959).

Cutkowsky, R. D., Harris, F. K., McGregor, M. C, and Hersh, J. F., New apparatus

at the NBS for absolute capacitance measurement, I.R.E. Trans, on Instrumentation

1-7, No. 3-4, 253 (1958).

Dade, E. C, Abelian groups of unimodular matrices, Illinois J. Math. 3, 11 (1959).

Danos, M., Low-energy limit of the photonuclear pseudodeuteron effect, Bull. Am. Phys.

Soc, Serv. II, 4, 102 (1959).

Davis, P. J., On the numerical integration of periodic analytic functions, chapter in

the book on Numerical Approximation, p. 45, edited by R. E. Langer (University

of Wisconsin Press, Madison, Wis., 1959).

Davis, R. M., Smith, E. K., and Ellyett, C. D., The effect of sporadic E on VHF trans- mission in North America, I.R.E. Spec. Govt. Issue 47, No. 5, 762 (1959).

Dibeler, V. H., Franklin, J. L., and Reese, R. M., Electron impact studies of hydrazine

and the methylsubstituted hydrazines, J. Am. Chem. Soc. 81, 68 (1959).

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as a function of temperature, J. Am. Ceram. Soc. 42, 254 (1959)

.

Wachtman, J. B., Jr., and Tefft, W. E., Effect of suspension position on apparent values

of internal friction determined by Forster's method, Rev. Sci. Instr. 29, No. 6, 517

(1958).

Wait, J. R., A phenomenological theory of induced electrical polarization, Can. J. Phys.

36, 1634 (1958).

Wait, J. R., A study of earth currents near a VLF monopole antenna with a radial wire

ground system, Proc. I.R.E. 46, No. 8, 1 (1958)

.

Wait, J. R., A study of VLF field strength data: both old and new, Geofisica Pura e Applicata (Milano, Italy) 41, 73 (1958).

Wait, J. R., An extension to the mode theory of VLF ionospheric propagation, J. Geophys.

Research, 63, No. 1, 125 (1958)

.

Wait, J. R., Downcoming radio waves, Elec. and Radio Engr. 36, No. 3, 106 (1959).

Wait, J. R., Diurnal change of ionospheric heights deduced from phase velocity, Proc.

I.R.E. 47, No. 5, 98 (1959).

Wait, J. R., Excitation of surface waves on plane and curved impedance boundaries,

Congres Intern, sur la Propagation des Ondes Radio-Electriques, October 6-11, 1958

( Liege, Belgique) , p. 26 ( 1958)

.

Wait, J. R., On the electromagnetic response of an imperfectly conducting thin dyke.

Geophysics XXIV, No. 1, 167 ( 1959)

.

Wait, J. R., On the theory of reflection from a wire grid parallel to an interface between

homogeneous media (II), Appl. Sci. Research Section B, 7, No. 5, 355 (1959).

Wait, J. R., Radiation from a small loop immersed in a semi-infinite conducting medium,

Can. J. Phys. 37, 672 (1959)

.

Wait, J. R., The calculation of the field in a homogeneous conductor with a wavy inter

face, Proc. I.R.E. 47, No. 6, 1155 (1959)

.

Wait, J. R., Transmission loss curves for propagation at very low radio frequencies,

I.R.E. Trans, on Commun. Systems CS-6, No. 2, 58 (1958)

.

Wait, J. R., Transmission of power in radio propagation, Elec. and Radio Engr. 36,

No. 4, 146 (1959).

Wait, J. R., and Conda, A. M., On the measurement of ground conductivity at VLF,

I.R.E. Trans, on Ant. Prop. AP-6, No. 3, 273 (1958)

.

Wait, J. R., and Conda, A. M., Pattern of an antenna on a curved glossy surface, I.R.E.

Trans, on Ant. Prop. AP-6, No. 4, 348 ( 1958)

.

Wait, J. R., and Conda, A. M., The patterns of a slot-array antenna on a finite and

imperfect ground plane, L'Onde Electrique 38, No. 376, 21, vis, Proc. Internat.

Congress Ultra High Frequency Circuits and Antennas, October 21-26, 1957 (Paris,

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166
Walker, H. H., Surface resistivity of cotton, wool, and nylon fabrics at different temperatures and relative humidities, Textile Research J. 28, No. 12, 1047 (1958).

Wall, L. A., Brown, D. W., and Florin, R. E., Electron spin resonance spectra from

gamma-irradiated solid nitrogen, J. Chem. Phys. 30, No. 2, 602 (1959).

Warwick, C. S., Green coronal line intensity and geomagnetism, J. Geophys. Research

64, No. 5, 527 (1959).

Warwick, C. S., and Wood, M. B., A study of limb flares and associated events, Astrophys. J. 128, No. 3, 801 (1959)

.

Washer, F. E., Report of the Committee on the American Standards Association, Phototogrammetric Engr. XXV, No. 2, 309 (1959)

.

Washer, F. E., and Darling, W. R., Factors affecting the accuracy of distortion measure- ments made on the nodal slide optical bench, J. Opt. Soc. Am. 49, No. 6, 517 (1959).

Wasilik, J. H., and Flippen, R. B., Piezoelectric effect in indium antimonide, Phys. Rev.

Letters 1, No. 7,233 (1958).

Waterhouse, R. V., The power output of a sound source in a reflecting environment,

Dissertation (Catholic University of America, Washington, D.C., 1959).

Watstein, D., and Mathey, R. G., Strains in beams having diagonal cracks, J. Am.

Concrete Inst. 30, No. 6, Title No. 55-46 (1958) ; Proc. Am. Concrete Inst. 55,

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Watt, A. D., Zurick, V. J., and Coon, R. M., Reduction of adjacent-channel components

from frequency-shift-keyed carriers, I.R.E. Trans, on Communs. Systems CS-6, 39

(1958).

Watts, J. M., The interpretation of night-time low-frequency ionograms, J. Geophys.

Research 63, 717 (1958).

Weitzel, D. H., Blake, J. H., and Konecnik, M., Flow conversion kinetics of ortho and

parahydrogen, Proc. 1958 Cryogenic Engineering Conference, Paper E-2, p. 286.

Edited by K. D. Timmerhaus, Chemical Engineering Dept. (University of Colorado,

Boulder, Colo., 1959)

.

West, E. D., The heat capacity of sulfur from 25° to 450°, the heats and temperatures

of transition and fusion, J. Am. Chem. Soc. 81, 29 (1959)

.

White, D., and Hilsenrath, J., Pressure-sensitive diaphragm-type null detector, Rev.

Sci. Instr. 29, No. 7, 648 (1958)

.

Wichers, E., Can the scales of atomic weights and nuclidic masses be unified? Phys.

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Wichers, E., Report on atomic weights for 1956-57, J. Am. Chem. Soc. 80, 4121 (1958).

Wildhack, W. A., Effect of transverse atmospheric drag on satellite orbits, Science

128,309 (1958).

Wildhack, W. A., and Stern, J., The peek-a-boo system, Chapter 6, Punched Cards,

p. 125 (Reinhold Publishing Co., New York, N.Y., 1959).

Wilson, W. K., and Forshee, B. W., Degradation of cellulose acetate films, SPE J. 15,

146 (1959).

Wood, L. A., Glass transition temperatures of copolymers, J. Polymer Sci. 28, No.

117,319 (1958).

Wood, L. A., Elastic properties of pure-gum rubber vulcanizates, Proc. Joint Army-NavyAir Force Conference on Elastomer Research and Development 2, 5th meeting (October

1958), p. 363 (Materials Laboratory, Wright Air Development Center, Wright-Patterson Air Force Base, Ohio, 1958)

.

Wood, R. E., Experiments with the cell Bi, Bi2 03 , ZnCl2/ ZnCl2/ZnCl2 , Zn between 450

and 510°, J. Phys. Chem. 63, 525 (1959).

Wyly, R. S., Comments on capacities of plumbing drains, Yearbook of the Am. Soc.

Sanit. Engr. 36, 243 (1958).

Wyly, R. S., Bain, K., and Faegre, M. L., Behavior of young children under conditions

simulating entrapment in refrigerators, Pediatrics 22, No. 4, Pt. I, 628 (1958).

Yannakopoulos, T., and Brenner, A., Isolation of the diffusion layer at an electrode and

the determination of concentration polarization, J. Electrochem. Soc. 105, No. 9, 521

(1958).

Yokley, C. R., and Ferguson. R. E., Separation of the products of cool flame oxidation of

propane, Combustion and Flame 2, No. 2, 117 (1958)

.

Patents

The following U.S. patents have been granted to NBS inventors; assigned (or licensed

as indicated) to the United States of America, as represented by the Secretary of the

department noted in parentheses:

Astin, Allen V., No. 2,877,452, March 10, 1959. Telemetering transmitter for a projectile. (Navy.)

Bennett, John A., and Burnett, Harry C, No. 2,844,958, July 29, 1958. Torsion fatigue

testing machine for wire. (Army.)

167
Bennett, John A., and Burnett, Harry C, No. 2,856,769, October 21, 1958. Torsion testing

machine for wire. (Army.)

Birmingham, Bascom W., Brown, Edmund H., Scott, Russell B., and Vander Arend,

Peter C, No. 2,871,042, January 27, 1959. Supporting and heat insulating means. (Atomic Energy Commission.)

Boggs, Gail E., No. 2,883,527, April 21, 1959. Stabilized nonlinear amplifiers. (Commerce.)

Brenner, Abner, and Bish, Joseph, No. 2,852,533, September 16, 1958. Titanium borohydride complex and preparation thereof. (Air Force.)

Broida, Herbert P., and Pellam, John R., No. 2,892,766, June 30, 1959. Formation and

stabilization of atoms and free radicals. (Commerce.)

Crane, Clarence B., No. 2,882,822, April 21, 1959. Fuze housing. (Navy.)

Davidson, Martin, and Rahal, Nicholas S., No. 2,854,626, September 30, 1958. Plating

thickness indicator. (Navy.)

Davis, William W., No. 2,853,649, September 23, 1958. Williams memory system using a double-intensity beam. (Commerce.)

Eichberg, Robert L., No. 2,879,657, March 31, 1959. Combination locks. (Licensed

to Commerce.)

Harmon, E'lise F., No. 2,844,172, July 22, 1958. Silk screen stretcher. (Army.)

Henderson, Joseph E., No. 2,892,093, June 23, 1959. Fuze. (Navy.)

Henig, Seymour, No. 2,863,574, December 9, 1958. Mail separator. (Commerce.)

Henry, Robert L., Jr., No. 2,843,263, July 15, 1958. Wafer gager. (Navy.)

Henry, Robert L., Jr., No. 2,892,129, June 23, 1959. Electronic module mounting device.

(Navy.)

Hewitt, Clifford A., No. 2,854,992, October 7, 1958. Flow control apparatus for reaction

columns and the like. (Commerce.)

Hinman, Wilbur S., Jr., and Diamond, Harry, No. 2,856,852, October 21, 1958. Proximity fuze. (Navy.)

Hinman, Wilbur S., Jr., No. 2,886,621, May 12, 1959. Sequential filled reserve battery.

(Army.)

Holt, Arthur W., No. 2,879,409, March 24, 1959. Diode amplifier. (Commerce.)

Huntoon, Robert D., No. 2,872,867, February 10, 1959. Ordnance construction. (Navy.)

Jaffe, Bernard, Roth, Robert S., and Marzullo, Samuel, No. 2,849,404, August 26, 1958.

Morphotropic piezoelectric ceramics. (Army.)

Kissinger, Charles W., No. 2,849,629, August 26, 1958. Chatter accelerometer. (Commerce.)

Kuder, Milton L., No. 2,870,436, January 20, 1959. Electronic analogue-to-digital

converter. ( Commerce.

)

Kuder, Milton L., No. 2,871,351, January 27, 1959. Balance detector used in electronic

analogue-to-digital converter. (Commerce.)

Lindseth, Clinton O., No. 2,880,378, March 31, 1959. Shaped processed circuitry.

(Navy.)

Macpherson, Alan C, No. 2,846,647, August 5, 1958. Microwave calorimetric wattmeter.

(Commerce.)

Mann, Douglas, and Macinko, John, No. 2,871,669, February 3, 1959. Radiation shield

circulation system for large liquefied gas storage containers. (Navy.)

Marzetta, Louis A., No. 2,871,432, January 27, 1959. Automatic tracking proximity gage.

( Commerce.

)

McLean, William B., No. 2,872,538, February 3, 1959. Inertia arming switch. (Navy.)

Moore, Dwight G., No. 2,857,292, October 21, 1958. Process for applying protective

metallic coatings. (Air Force.)

Pawley, Myron G., No. 2,845,613, July 29, 1958. Phase-sampling telemeter. (Commerce.)

Rabinow, Jacob, Bailey, Emmett C, and Shepard, Francis H., Jr., No. 2,849,197, August

26, 1958. Servo control mechanism. (Navy.)

Rayburn, Charles C, and Henry, Robert L., No. 2,887,622, May 19, 1959. Electrical

circuit pattern tester. (Navy.)

Reid, Margaret A., and Brenner, Abner, No. 2,849,336, August 26, 1958. Method of

producing boride coatings on metal. (Commerce.)

Reinhart, Frank W., Slone, Murray C, Horn, Leon, and George, Desmond A., No.

2,852,424, September 16, 1958. Reinforced plastic springs. (Army.)

Rosenberg, Samuel J., and Irish, Carolyn R., No. 2,863,763, December 9, 1958. Ductile

and tough high-strength steel. (Navy.)

Russell, Henry H., No. 2,882,038, April 14, 1959. Large-capacity balance. (Commerce.)

Sargent, Jack, No. 2,892,346, June 30, 1959. Volume flowmeter. (Licensed to Commerce. ) Saunders, Edward R., Jr., No. 2,855,511, October 7, 1958. Biased peaker strip energy

control system for betatrons and synchrotrons. (Commerce.)

168
Seal, Robert K-F, No. 2,848,697, August 19, 1958. Plug-in packaged waveguide assembly.

(Commerce.)

Seal, Robert K-F, No. 2,879,455, March 24, 1959. Miniature radar subassembly.

(Navy.)

Seal, Robert K-F, and Lindseth, Clinton 0., No. 2,889,493, June 2, 1959. Miniature

radar assembly. (Navy.)

Seal, Robert K-F, No. 2,890,863, June 16, 1959. Combined pressure cooling system and

chassis for miniaturized radar. (Navy.)

Selby, Myron C, No. 2,882,501, April 14, 1959. Micropotentiometer. (Commerce.)

Selby, Myron C, Allred, Charles M., Hudson, Paul A., and Berry, Ira S., No. 2,883,620,

April 21, 1959. High-frequency power measuring bridge circuit. (Commerce.)

SenderofT, Seymour, and Reid, Walter E., Jr., No. 2,843,541, July 15, 1958. Electrophoretic deposition of barium titanate. (Army.)

Shapiro, Gustave, and Feler, James R., No. 2,835,816, May 20, 1958. Adjustable low

inductance capacitor with separately rotatable slotted disks for tracking adjustment.

(Navy.)

Shapiro, Gustave, No. 2,879,491, March 24, 1959. Plug system for joining electric subassembly to chassis. (Navy.)

Smith, Denton L., and Caul, Harold J. (Research Associates), No. 2,864,695, December

16,1958. Cobalt-gallium dental alloys. (Commerce.)

Stansbury, Carroll, and Montgomery, George F., No. 2,889,519, June 2, 1959. Clamptype current transducer. (Commerce.)

Sulzer, Peter G., No. 2,871,356, January 27, 1959. Frequency-stabilized oscillator.

(Commerce.)

Vander Arend, Peter C, and Mann, Douglas, No. 2,882,694, April 21, 1959. Cool-down

apparatus for cryogenic liquid containers. (Commerce.)

Weaver, Preston R., No. 2,867,382, January 6, 1959. Maneuvering loads accelerometer.

(Navy.)

Weinberger, Arnold, and Smith, John L., No. 2,879,001, March 24, 1959. High-speed

binary adder having simultaneous carry generation. (Commerce.)

Witt, Richard P., and Griffin, Dana A. (Communication Measurements Laboratory, Inc.),

No. 2,864,977, December 16, 1958. Plug-in packages. (Commerce.)

Witt, Richard P., No. 2,866,948, December 30, 1958. Test circuit for interconnected

components. (Army.)

169

U.S. GOVERNMENT PRINTING OFFICE : 1960 O—531788

REPORTING . . . NBS Research and Development

^Journal of Research of the National Bureau of Standards contains full research

papers, including laboratory data, experimental procedures, and theoretical and mathematical analyses. Advances in measurement standards and techniques . . . physical

constants . . . properties of materials . . . instrumentation . . . radio propagation.

The Journal is published in four separate sections . . . A. Physics and Chemistry—issued six times a year; Annual subscription: Domestic,

$4.00; Foreign, $4.75.

B. Mathematics and Mathematical Physics—issued quarterly; Annual subscription:

Domestic, $2.25 ; Foreign, $2.75.

C. Engineering and Instrumentation—issued quarterly; Annual subscription: Domestic, $2.25; Foreign, $2.75.

D. Radio Propagation—issued six times a year; Annual subscription: Domestic,

$4.00; Foreign, $4.75.

^National Bureau of Standards Technical News Bulletin—illustrated concise articles on NBS programs in the physical sciences, with emphasis on results of research, are chosen on the basis of their scientific and technological importance. The Bulletin

reports advances in measurement standards and techniques and announces all publications and patents of staff members. Special events and technical meetings involving

the Bureau are summarized.

Issued monthly.

Annual subscription: Domestic, $1.50; Foreign, $2.25

BORDER FROM Superintendent of Documents, U.S. Government Printing Office,

Washington 25, D.C.