RESEARCH HIGHLIGHTS

OF TH E

NATIONAL BUREAU OF STANDARDS

ANNUAL

REPORT ill

UNITED STATES DEPARTMENT OF COMMERCE

Lewis L. Strauss, Secretary

NATIONAL BUREAU OF STANDARDS

A. V. Astin, Director

Research Highlights

of the

National Bureau

of Standards

Annual Report, Fiscal Year 1958

For sale by the Superintendent of Documents, U. S. Government Printing Office Washington 25, D. C. - Price 45 cents

December 1958

Miscellaneous Publication 226

Contents

Tage

L. General Review _; 1 Technical Activities 2 Administrative Activities 9

Publications 10

2. Highlights of the Research Program 11

2.1. Electricity and Electronics 11 Capacitance measurements based on the calculable capacitor 11, Semiconductor research 11, Surge voltage measurements 12, Cunife wire magnets 13, Ultra-low frequency measurements of

dielectric properties 13, Electron-tube material sublimation 13, Noise in fixed resistors 13, A provisional faraday value 14, Electric cells at high temperature 14, Recharging of dry cells 15, Internal resistance of dry cells 15, Heats of adsorption 15, Aircraft and missile batteries 15, Postal automation 15.

2.2. Optics and Meterology 16 Photometric standards 16, Spectrophotometric data electroni- cally computed 17, Conversion of colorimetric data to Munsell

terms 17, Anticollision lights for airplanes 18, Refractive index

of synthetic sapphire 19, Calibration of airplane cameras 19, Standards for spectacle lenses 19, Automatic lens design 19, Atomic beams for defining length 19, High-precision gage

blocks 20, Screw thread standards 21.

2.3. Heat 21

Statistical thermodynamics 21, International temperature stand- ards 22, Resistance thermometry 23, High-temperature pyrometers 23, Parity and time reversal 24, Heat measurements on

sulfur 24, Thermodynamic properties of rubber 25, Viscosity standards 25, Rheology 26, Free radicals 26.

2.4. Atomic and Radiation Physics 28

Spectroscopic research 29, Free radical studies 29, Behavior of semiconductors 30, Electron polarization 31, Scattering of low- energy electrons 31, Proton gyromagnetic ratio 31, Rubidium

vapor magnetometer 32, Structure of negative ions 32, Neutron

"age" 32, Phosphor-in-plastic fast neutron detectors 32, Penetration of gamma radiation 33, Gas radioactivity standards 33, X-ray studies 33, Nuclear structure 34, Radiation absorption

34, X-ray and gammaray dosimetry 34.

2.5. Chemistry . 35 Analysis of small amounts of tungsten in steel'35, Purification of titanium halides 36, Evaluation of purity 36, Spectrograph^

determination of 18 elements 36, Current integrator 36, Radioactive sugars 37, Oil-soluble metal standards 37, Boron compounds as potential fuels 38, Separation of free radicals 38, Instrument for estimating night vision 39, Plasma jet for alloy analysis 39, Other chemistry programs 39.

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Page

2.6. Mechanics 39

Acoustic impedance of the ear 39, Audiometry 40, Vibration pickups 40, Magnetic tape standards 41, Pressure measurement

41, Telemetering transducers 41, Promotion of flow by mixing

41, Friction between density currents 42, High strength aero- nautical fasteners 42, Creep of structural beams 43, Windinduced vibration of wire 43, Thermal stresses in aircraft parts

43, International density comparisons 44, Measurement of jet engine temperature 44.

2.7. Organic and Fibrous Materials 44

Stress-strain relation for rubber 45, Analysis of textiles 45, Impact

phenomena in fibers 45, Improved map paper 46, Preservation

of archival documents 46, Impregnation of leather 46, Impact

test for leather 47, High-temperature fluorine polymers 48, Molecular constants of polymeric materials 48, Dimensional

changes in fibrous macromolecules 48, Polymer-glass adsorption

studies 49, Radiation stability of plastic packaging materials

49, Stability of polyvinyl chloride plastics 49, Mechanism of rain erosion 49, Vapor phase analysis of polymers by chromatography 50, Low-angle diffraction studies 50, Speed-torque measurements of high-speed dental instruments 50, Denture

reliners 51.

2.8. Metallurgy 51

Constitutional diagrams for metals 52, Commercially important

alloys 52, Uranium alloy studies 52, High-temperature metals

52, Titanium 54, Plastic deformation 54, Gage block materials evaluated 54, Corrosion 55, Growth of metal crystals from their vapor 56, Gases in metals 56, Metal fatigue cracks 57.

2.9. Mineral Products 57

Ferroelectric materials 57, Low-temperature X-ray crystallography 58, Phase equilibrium studies 58, Ceramic dielectrics 59, New data on silicates and related compounds 59, Crystal

structure of inorganic materials 60, Standard X-ray diffraction patterns 60, Radiation control for rockets and satellites 61, Mechanism of ceramic-metal adhesion 61, Glass transition temperatures 61, Chemical analysis of cements 62, Coatings

for supersonic vehicles 62, Refractory castables 63, Standard

glass for measurement of physical properties 63. 2.10. Building Technology 63

Fire hazards of common combustible materials 64, Fire retard- ants for fabrics 64, Standards for refrigerated trailers 64, Underground pipe insulation 65, Conductive flooring in danger areas

66, Degradation of asphalt 66, Strains in reinforced concrete beams having diagonal cracks 66, Drying shrinkage of concrete masonry units 67, Moisture in insulated roof constructions 67, Thermal conductivity of metals 68, Capacity of horizontal plumbing drains 68. 2.11. Applied Mathematics 69 Approximation theory 69, Matrix code studies 69, Eigenvalue

theory for differential operators 70, Mathematical tables 70, Digital computation 70, Reliability studies 70, Experiment

design 71, Continuum mechanics 72, Theory of orbits 72.
Page

2.12. Data Processing Systems 72 SEAC as a research facility 72, Analog computers 73, Pilot elec- tronic da la processor 73, Components and techniques 73, Transistor-magnetic core circuitry 74, Rapid selector 74, Digital systems research 75, Advanced computer systems 75, Man-machine systems simulation 75, Aircraft flight-loads data

processing 76, Data processing applications 76, Processing first- class mail 77.

2.13. Cryogenic Engineering 78 Low-temperature liquids 78, Cryogenic engineering data 79, Flow

of liquefied gases 79, Storage of liquefied gases 80, Hydrogen

refrigerator for bubble chamber 80, Helium liquefaction 80, Low-temperature properties of materials 81, Gas liquefaction 82.

2.14. Radio Propagation 82 Radio Propagation Physics 82 Radio waves from lightning discharges 83, Meteor studies 83, Airglow observations 84. Radio Propagation Engineering 84 Radio meteorology 85, Tropospheric forward scatter 85, Ionospheric propagation on the range 10 to 1,000 kc 85, Radio

modulation studies 85, Measurement of television service area 85. International Geophysical Year 86 IGY world alerts 87, New data on the ionosphere 87, Observations on Soviet satellites 87, Propagation near the magnetic

equator 88.

2.15. Radio Standards 89 Attenuation 89, Field-strength 89, Frequency 89, Impedance 90, Noise and interference 91, Power 91, Voltage and current 92, Dielectric measurements 93, Magnetic materials 93, Conductivity of materials 93, Microwave spectroscopy of gases 93, Milli- meter wave research 94.

2.16. Basic Instrumentation 94

Instrumentation reference service 94, Information retrieval systems 95, Basic instrumentation research 95.

3. Calibration, Testing, and Standard Samples 95 Nomenclature of Standards 96 New Calibration Facilities and Equipment 96

Electronic calibration center 96, Standard radio broadcasts 97, Standard capacitors 97, Automation of end standard calibration 98, Deadweight testing machine 98. Calibration Services 99

Services discontinued 99. Testing Services 101 Standard Samples 101 Inter -Laboratory Reference Sample Program 104

4. Cooperative Activities 105

Specifications and Test Methods for Government and Industry 106 International Activities 108 Cooperative Research with Industry 1 10 Free radical research 111. Weights and Measures 1 '2 Education Program 1 13

V
. Appendixes

5.1. Organization

5.2. Fiscal Data on NBS Program. _ _ 5.3. Advisory Committees—„ 5.4. Awards and Honors

5.5. List of Publications and Patents

VI
1. General Review

During this past year the National Bureau of Standards was encouraged

to examine its programs and responsibilities critically and to estimate its needs in meeting modern requirements for standards, measurement tech- niques, and data on the properties of materials.

For some time, the Bureau had called attention to the rapid advancement of technology and to expansion of research noting that these changes

have placed a strong burden upon NBS—a responsibility to enlarge its technical programs in support of growing national scientific activities. In the past year, the Bureau received added support from the Congress

and from the Administration to strengthen its capability for leadership

in the science of physical measurement.

The responsibility for the Nation's fundamental standards of measure- ment demands a continuous search for new scientific knowledge and lor improved measurement processes. As new areas of science and technology become active or productive, new standards must be developed,

adequate measurement methods established, new instrumentation devised,

and appropriate calibration services provided. All this must be done

while advancing the established areas of measurement and in such a manner as to maintain and insure continued consistency and coherence

within the whole complex chain of measurement.

The work is basic to the measurement, understanding, and control of

physical phenomena. This is especially true in relation to the exploration

of new aspects of the physical world. For this reason, it is essential that NBS technical programs be as modern as contemporary scientific research. This report highlights some of the Bureau's activities during 1958.

It will describe in varying detail a wide range of scientific studies, lab- oratory experiments, instrument developments, and technical publications. However varied these technical programs may seem, they have

this in common: they contribute to the improvement of the measure- ment sciences. This is an area of broad import. Even if the details of

all Bureau projects of 1958 could be presented in this report, they would

represent only that area of the Bureau's total responsibility which could

be implemented for that year. Thus the program is always a selection of technical projects of highest relevance to current technological need.

Because the Bureau's responsibilities are so broad yet so direct l\ important to science and the national economy, it may be well to summarize in this introduction these responsibilities, as defined by the Congress:

(1) Development and maintenance of the national standards <>l measurement,

and the provision of means for making measurements consistent with those standards;

1
(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 govern- ment. Technical Activities

The following paragraphs briefly summarize some of the more important accomplishments of the technical program during fiscal 1958. As

in previous years, the program was concerned primarily with the development and improvement of standards and methods of physical measure- ment. A second major focus of activity was the precise determination of

fundamental physical constants and the basic properties of materials.

More complete details of the research and development projects discussed

below may be found in section 2, page 11 et seq. Standards and Measurement Methods. In work directed toward

improved electrical standards, apparatus was developed which markedly

increases sensitivity and precision in the precise intercomparison of small

capacitors. To realize fully the advantage provided by this apparatus, an improved standard of capacitance, based on a theorem in electrostatics recently published in Australia, was constructed. The design of this standard permits its value to be calculated in terms of a single measured

length to an accuracy of about 3 parts per million. Efforts continued to improve pressure calibration techniques throughout

the pressure range. For static calibrations at high pressures (up to 200,000 lb/in.2

) piston gages were further developed, and the characteristics of air-lubricated piston gages were investigated for use as standards

in the range of differential pressures from those presently covered by

mercury columns up to several hundred pounds per square inch. Under sponsorship of the Air Force, work was completed on a mercury

U-tube standard for calibration of instruments over the pressure range

corresponding to high altitudes. In work on dynamic pressure calibra- tions sponsored by the Department of Defense, an improved shock tube was developed and placed in operation providing step pressures up to 1,000 lb/in. 2 High-temperature measurements also received emphasis. Research was

conducted to increase the accuracy of pyrometer calibrations at temperatures between 2,500° and 4,000° C. Zirconium and carbon arcs were adapted for calibration use to permit direct observations up to about

3,800° C. Progress was made in developing an atomic beam source of mercury

radiation whose wavelength may provide a very accurate means of

measuring length. The dielectric constant of heavy water was experi-
mentally determined from 0° to 100° C. The certification of the Bureau's

pll standards, formerly available for the temperature range from 0° to 60° C, was extended to 95° C to meet the requirements of pll control in many industrial processes. Studies were conducted to improve methods of determining molecular

weights. For this program an absolute photometer was designed and

built to measure precisely the light scattered by solutions of polymers.

With data obtained with this instrument, more reliable values can be

determined for molecular weights and radii of molecules.

Recent developments in rocketry, jet propulsion, and high-speed

turbines have increased the need for accurate vibration measurements at very high acceleration levels. To meet this need, a method was developed

for calibrating lightweight vibration pickups at acceleration levels more

than 1,000 times the acceleration of gravity, over the frequency range

from 500 to above 10,000 cycles per second.

Further progress was made in a research program on high -precision gage

blocks which is partially supported by industry. This program seeks regular methods for calibrating industry's master gage blocks to an

accuracy of 1 part in 10 million. These gage blocks, which ultimately

control the tolerances of mass-produced machine parts, are now calibrated

at the Bureau to an accuracy of 1 part in 1 million, that is, to the nearest

millionth of an inch for inch-long blocks. However, American machine

tool manufacturers have requested an even higher degree of accuracy in gage-block calibration in order to keep pace with the needs of the aircraft and other industries. In 1958 emphasis in this project was shifted from the development of

improved measuring instruments to the application of these instruments

to the development of more precise gage blocks. Studies were made of

the suitability of different steels for constructing the blocks. Optimum

conditions were also established for heat-treating and stabilizing several of the steels commonly used for gage blocks. Physical Constants. An important advance in the field of physical constants was the redetermination of the gyromagnetic ratio of the proton.

By measuring the precession rate of protons in a magnetic field, a pre- liminary value of (2.67515 ± 0.00001) X104 radians/(sec gauss) was

obtained. However, when combined with a recent determination of the

ampere at the Bureau in absolute units, the value becomes (2.67513

± 0.00002) X104 radians/(sec gauss).

As this value is considerably more accurate than the earlier one obtained

in 1949, it should make possible more accurate values for many of the

fundamental constants of physics such as the electron charge-to-mass

ratio e/m, the magnetic moment of the proton, and Planck's constant //. The new value will also be useful in the design and development of scientific and industrial apparatus (e. g., cyclotrons, servo mechanisms) in which it is important to know accurately the spatial distribution ol a magnetic field or to regulate it closeh

3
Apparatus used to redetermine the new value will make possible more

fundamental constants of physics,

magnetic fields (pages 3, 31).

gyromagnetic ratio of the proton. The

accurate determination of many of the

and will provide a better standard for

4
Another fundamental constant investigated during the year was the

faraday. For several years the Bureau has been engaged in research to determine a more accurate value for this constant. In 1958 the work had

progressed to the point that a provisional value of 96,523 coulombs per gram equivalent on the physical scale could be given. This value agrees within 1 part in 100.000 with the average value determined at the Bureau

on the omegatron (a miniature cyclotron) in 1953. Properties of Matter and Materials. A number of techniques were

developed for determining very small amounts of impurities in materials.

At the request of the Diamond Ordnance Fuze Laboratories, Department of the Army, procedures were devised for detecting small amounts

of impurities in barium titanate. Because of its piezoelectric properties,

pure barium titanate is of considerable interest in the field of communications. A photometric method for the determination of tungsten in steel and in titanium alloys was completed, and flame photometry was successfully applied to the determination of sodium* potassium, calcium, and

strontium in the presence of other alkali and alkaline earth ions. In work

sponsored by the Office of Naval Research, an improved procedure was

developed and used to prepare very pure halides of titanium.

Although sulfur has been known since ancient times, accurate data on manv of its properties have been lacking, largely because it is difficult to purify and exists in many crystallographic forms. During the year

99.999-percent pure sulfur was used to make accurate measurements of

the heat capacity of this element. These data should aid in predicting

the reactions of sulfur and its compounds at high temperatures, as in petroleum refining.

Volume III of "Atomic Energy Levels" was published and distributed.

This volume included analyses of optical spectra of the elements Molybdenum through Lanthanum (Z=42 through 57) and Hafnium through

Actinium (Z=72 through 89). In work sponsored by the Navy Bureau of Aeronautics, the " plasma

jet," an electrical source for exciting the spectra of materials, was developed. This source, which has been applied to the analysis of stainless

steel, shows considerable promise for the determination of the major

constituents of complex alloys.

Isotopicallv labeled carbohydrates provide a powerful tool for probing

the mysteries of biological chemistry. Development of methods for synthesizing sugars and related compounds position labeled with carbon-14,

which has been sponsored by the Atomic Energy Commission, was con- tinued and extended to tritium-labeled compounds. Procedures were

developed for the production of a variety of tritium-labeled compounds

and for their convenient analysis.

Basic thermodynamic data are required for the design and performance

evaluation of such equipment as gas turbines and jet and rockel engines,

and in the solution of many aerodynamic, astropln sical. and astronautical

problems. In 1958 high-speed automatic computing techniques were

5
developed to extend such data over a wide range of temperature and

density. These techniques were applied to a systematic generation of

extensive tables of ideal-gas thermal functions of atoms, molecules, and

their ions. Studies of the thermochemical properties of boron compounds—of

particular interest in the search for high-energy fuels—were continued

under the sponsorship of the Navy Bureau of Aeronautics. Mass-spectrometric methods were utilized to determine the energies of the chemical

bonds between boron and other atoms.

In a program on statistical thermodynamics, significant progress was made in the development and application of theoretical methods to such

problems as quantum effects on surface tension of simple liquids; isotope

effects on the compressibilities of isotopic hydrogens; statistical mechanical description of the transport, equilibrium, and magnetic properties of

electron gases: molecular orbital calculations of the H3 molecule; and

partit ion -function representation of atoms and atomic ions to 1.000,000°K,

and molecules and molecule ions to 25.000°K.

The development of new and improved textiles has made necessary a continuing effort to devise adequate analytical methods for these products.

During the year a rapid, convenient method was developed for identifying

the components of very small specimens of finished and coated textiles. The method is also applicable to related materials such as coated papers,

adhesives, and plastics.

The stability of polyvinyl chloride and its copolymers has been a major

problem to the plastics industry. These polymers are sensitive to heat,

sunlight, and traces of metals. An investigation showed the mechanism

of decomposition to be a free radical chain reaction. This result pro- vided a basis for the selection of stabilizers on a rational rather than an

empirical basis. Applied Mathematics. Work in applied mathematics was principally concerned with the solution of problems in numerical analysis and

certain areas of mathematical physics, in the compilation of specialized

mathematical tables, and in the application of modern statistical inference

to problems of experimental design and sampling. In numerical analysis significant progress was made in the development

of eigenvalue theory for differentia] operators. Other projects dealt with

such topics as numerical integration of periodic and analytic functions,

calculation of the best (Chebyshev) polynomial approximation to a given

function, testing of matrix codes, and location of the eigenvalues of

matrices.

Research in mathematical physics was concentrated principally on the

continuum mechanics of elastic and fluid media, magnetogasdynamics,

the theory of orbits, and mathematical analysis related to problems in mathematical physics. In fluid mechanics, the Stokes flow problem was

solved for several axi-symmetric bodies not hitherto considered, and

6
certain new theorems in the theory of Stokes flows were proven. An exact

solution of the problem of the unsteady water wave in a straight channel

of arbitrary slope was given. Previously, onlv numerical solutions of

this type of problem have been available. Also completed was an analyst

of bending and stretching of corrugated diaphragms, with important

applications in the field of instrumentation.

Statistical studies of the reliability of components and assemblies led to the formulation of mathematical models for the analysis of experiments on

the aging of components, and methods of estimating pertinent parameters were worked out. This work, which is applicable to a variety of aging

studies, formalized and improved methods of analysis that had previously

been based on intuitive grounds.

Work was begun on a Handbook of Mathematical Functions. When

completed, the volume will cover the entire field of special functions and

will contain mathematical properties, graphs, and comprehensive tables. Data Processing Systems. The system design plans for a new pilot

electronic data processor were essentially completed and the engineering necessary for constructing the machine was well under way. This

general-purpose machine is designed to process digital information at very high speed. It will be used for experimental investigations of such

large-scale problems as air-traffic control and patent searching.

Research in collaboration with the Li. S. Patent Office for the mechanization of patent search operations continued. A program for comprehensive search of chemical patent literature was extended, and a program was developed for general search, with emphasis on mechanical arts. Radio Propagation. The Boulder Laboratories continued to conduct

research on the forward scatter of radio waves. First reported in 1955.

this new mo ie of radio propagation is greatly extending the limits of longdistance communication. An improved formula for predicting the

expected transmission loss on tropospheric forward scatter circuits was

developed, making possible more accurate predictions particularly for propagation paths with unusual terrain profiles or climatology, for very high antennas, and for the louver frequencies.

As in 1957, a part of the technical program of the Boulder Laboratories was concerned with Lnited States participation in the International

Geophysical Year of 1957-58. For this cooperative scientific effort the Bureau's principal activities were the gathering and analysis of data on

upper atmospheric phenomena and radio propagation.

As part of the IGY program, the Bureau intensified its stud} of the

reflection of very high frequencies from the ionosphere—a phenomenon

known as sporadic-E— -which causes FM and television signals to be

transmitted over distances of more than 1,000 miles. To deled differ- ences in the ionosphere over the Eastern and Western Hemispheres,

carefully controlled circuits for studying sporadic-/*, were set up between

the Philippine Islands and Okinawa, between the Panama Canal Zone

and Cuba, and within the Lnited States.

7
The Bureau's Electronic Calibration Center initiated operations in 1958. The Center was established to meet the urgent need by Government, industry,

and the military services for electrical and electronic standards. Above, a

large audience of scientists and other invited guests gathered for the formal

dedication ceremonies in Boulder, Colo, (pages 9, 96).

Experimental transmitting and receiving stations were also operated

in Chile, Peru, Ecuador, Argentina, Brazil, and Panama in order to study special forms of oblique -incidence ionospheric scattering that occur

in the vicinity of the magnetic equator.

Calibration, Testing, and Standard Samples. The Bureau con- tinued to perform an important service to science and industry through

its calibration activities, which insure the accuracy of countless measuring

instruments throughout the Nation. More than 134,000 calibrations and

tests were carried out in fiscal year 1958. In addition, about 55,500

individual standard samples of chemicals, metals, and other materials were distributed to analytical and research laboratories for use in controlling chemical processes and in matintaining the accuracy of apparatus

and equipment. Thirty-eight new standard samples were developed

during the year, bringing the total number of standard samples available to well over 600. The calibration and testing activities are discussed more fully in section 3, page 95 et seq. Cooperative and Consulting Services. Cooperative activities ranged from advisory services for other Government agencies to the

development of codes and specifications in cooperation with scientific and technical groups. During 1958 the Bureau participated in the work

of hundreds of technical committees, societies, associations, and commissions organized to bring new advances of science into the technology

of industry, to standardize materials and products for greater economy

and improved quality, and to establish uniform scientific standards

throughout the world. Cooperative activities are discussed more fully in section 4, page 105 et seq.

8
Administrative Activities

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

fees paid by private organizations for calibration services and standard

samples, and gifts from private sources. During 1958, the total funds obligated, including construction and

facilities, were $29,158,000. Of this total, $9,724,000 came from the

direct appropriation for the Bureau's research and technical services and

$473,000 from the direct appropriation for construction and facilities. The remaining $18,961,000 came from other agencies and private sources

(see appendix 5.2). At the close of the year the Bureau's staff of 3,260 included 1,430 in the professional categories and 1,830 in other classifications. In the

professional group were some 560 physicists, 300 chemists, 240 engineers,

and 120 mathematicians. Almost three-fourths of the total were in Washington, D. C, and a little less than one-fourth at Boulder Laboratories, with the remaining few scattered among the Bureau's field stations. During the year, the Electronic Calibration Center at the NBS Boulder

Laboratories was activated, This Center will serve both defense agencies

and industry in the calibration of electronic equipment and working

standards in terms of the Bureau's primary standards of electrical quantities at frequencies above the audiorange, and will supplement the

services available at the Washington laboratories at direct current and

low frequencies (see page 96).

Bureau management undertook, during the year, a major reassessment

of the adequacy of the Bureau's programs in terms of the needs of science

and industry and with particular regard to international technological

competition. The need for strengthened research programs in a number

of areas was identified and additional emphasis was given to the Bureau's

policy of shifting program emphasis from other-agency -oriented programs

to programs more closely related to the Bureau's primary responsibilities.

The review of NBS responsibilities, programs, and capabilities also directed increased attention to the problems of research equipment and

laboratory facilities. Additional effort went into the preliminary planning of new laboratory facilities, and at the close of the year funds were

appropriated to finance detailed architectural design of new laboratories to be located at Gaithersburg, Maryland.

During the year, the Bureau revised its arrangements for program

review and advice from scientists and engineers in universities and

industrial organizations. The advisory committees were re-established as committees of the National Academy of Sciences, which will coordinate

their activities and reports. This change is expected to increase the value

to Bureau management of the consultation and program advice provided

by these prominent representatives of the nation's scientific and

technological community.
Publications

The results of the Bureau's technical program are in general embodied

in its reports and publications. Even when the work is developmental

in nature—lor example, the development of a specific device —a report

will represent the culmination of the activity , and it is this report that

will often prove of most value to Government, science, and industry.

The reports and publications of the Bureau are, therefore, suggestive of

the scope of its activities. During the year these totaled 1,412, exclusive

of calibration and test reports and of general administrative documents.

Some 760 classified and unclassified reports were issued to other government agencies, particularly the Department of Defense, while 652 papers

and documents were published formally.

Of the formal publications, 109 were published in the Journal of Research of the National Bureau of Standards (a monthly periodical) and

388 in the journals of various professional, engineering, and trade organizations. There were 128 summary articles published in the Bureau's monthly Technical News Bulletin. Twenty -seven papers were published

in the Bureau's nonperiodical series of publications: 4 in the Applied

Mathematics Series, 5 in the Handbook series, 14 in the Circular series, 1 in the Building Materials and Structures Report series, and 3 in the

Miscellaneous Publication series. The third monthly periodical of the Bureau, Basic Radio Propagation

Predictions, which is published each month 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

5.5 (page 122).

10
2. Highlights of the Research Program

The Bureau's technical program is carried out through organizational

units called Divisions. These are shown in appendix 5.1. A review ol selected 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. as far as possible, constant over long periods of time, uniform throughout the Nation, and con-istent

with the fundamental mechanical units. The work includes the dis- semination of standards of electrical resistance, inductance, capacitance,

dielectric constant and loss, electromotive force, current, power, energv, magnetizing force, and magnetic induction.

The electronic activities include the standardization of test methods

for electronic components, the study of materials and processes for component fabrication, and the establishment of optimum designs of

electronic equipment for maximum life and reliabilit\ . In areas in which the Bureau is uniquely qualified, electronic development programs

are undertaken to meet the special requirements of the Bureau and of

other governmental agencies.

Capacitance Measurements Based on the Calculable Capacitor.

The performance of such complex assemblies as automated systems or guided missiles ultimately depends on the stability and the accuracy of

ad justment of the system components. Even now the accuracies required

in some electrical components are approaching those with which the

standard electrical units themselves are known. Based on recent pioneering work at the Australian National Standards Laboratory, the NBS

facilities for the establishment, maintenance, and dissemination of the unit of capacitance were improved during the past year. The capacitance unit is determined on a bridge that makes precise

measurements possible over a range from 10-6 to 1 microfarad. The

heart of the bridge is a three-winding transformer with extremel) low

secondary impedances, and ratio errors less than 3 parts in 10 million. Incorporated into the bridge is a calculable capacitor of the cylindrical

cross-capacitance type. Its value is calculated from the measured

lengths of the precision gage bars from which it is constructed. Indications are that the capacitance unit so established is consistent with the basic mechanical units to within a fen parts in a million. Semiconductor Research. Semiconducting materials are intrinsi- cally interesting from a scientific viewpoint because the stud) ol their structure and behavior leads to increasing knowledge of the Fundamental

489867—59 2

1 1
An improved standard of capacitance of the Thompson-Lampard type was

constructed utilizing gage bars of precisely known lengths. Its value can be

calculated in terms of the primary standard of length to better than 10 parts

in 1 million (page 11)

properties of matter. Also of importance is the applicability of their

special electrical properties to practical engineering devices. The materials are numerous, and practical application of some of their more

unusual properties appears to have only begun.

Conductivity versus temperature was determined for a number of

samples of semiconducting materials. These included barium titanate

containing controlled amounts of the elements samarium, aluminum,

silicon, and neodymium. One useful discovery is that conductivity

decreases rapidly with temperature in the region of a critical temperature

depending upon the composition of the material. Simple temperature

controls and current regulators may be useful applications of this effect. Additional phases of this program are the measurement for the Air Force Cambridge Research Center of thermoelectric, Hall-effect, and

electroluminescent properties of these and other material Electrical measurements are being correlated with physical measurements made in the Bureau and elsewhere to derive eventually a basic structural theory.

Surge Voltage Measurements. Most electrical insulating materials can withstand, for very short intervals, a somewhat higher voltage than

is sufficient to produce electric breakdown or flashover on continuous

60 cycles per second voltage. Because the effect is large enough to repre- sent some additional protection in the case of direct lightning strikes, it 12
is important to make reliable measurements of electrical breakdown

values on steeply rising voltages. Better measurements of voltage values

for such surges are now being obtained by using an improved design of surge resistor unit developed during the year. These 50 kv units, 7 in. long, are required to withstand repeated 60-kv chopped surges. In order

to obtain a low-time constant, metal resistance-tape instead of wire is used for the two reversed windings on a notched methyl methacrylate

card. The high order of insulation required is achieved by encapsulating

the wound card in an air-bubble -free molding of clear epoxv resin. Cunife Wire Magnets. The need for extremely small permanent

magnets led to a study of the magnetic properties of Cunife wire. This

alloy (60-percent copper, 20-percent nickel and 20-percent iron) has a high coercive force and yet is sufficiently ductile to be cold drawn to

fine wires. This investigation showed that it is possible to produce

satisfactory permanent magnets as small as 0.005 in. in diameter by

cold drawing larger sizes of Cunife through dies. If the cold-drawn wire

is subjected to a simple heat treatment, the resulting permanent magnet

properties are satisfactory for many magnetometer and galvanometer

uses. Ultra-Low Frequency Measurements of Dielectric Properties.

During investigations of the electrical properties of polymeric insulating

materials, it was found that ultra-low frequency dielectric data would

be useful in understanding the nature of molecular motions in the crystalline and supercooled liquid, glassy states of such materials. Accordingly, a three -terminal bridge was constructed that yielded dielectric constant and loss measurements from 0.1 to 200 cycles per second. The

results obtained with the apparatus were shown to be accurate to about

0.005 for the dielectric loss factor and about 0.4 percent for the dielectric constant. Measurements were made on polychlorotrifluoroethylene over

a wide temperature range and work is now in progress on other polymers.

Electron-tube Material Sublimation. There is much evidence

that an electron tube often fails prematurely because of changes in the

emissive properties of the materials from which it is made. The metallic

parts of the cathode, for example, vaporize and recondense on other parts

of the tube structure. The tube's electrical parameters are changed

by this sublimation, and the emission efficiency of the cathode is lowered.

Under the sponsorship of the Air Force Cambridge Research Center,

the sublimation of electron-tube materials is being measured with a sensi- tive vacuum microbalance developed at the Bureau. The results of

these measurements are expected to lead to improvements in electron - tube materials and in tube production methods.

Noise in Fixed Resistors. Undesirable electrical noise is generated

by composition- or film-type fixed resistors that earn direct current. \ standard test set was developed for the Navy Bureau of Ships to measure

this property of a resistor. Copies of the test set are being installed in several Navy and Air Force laboratories. Their use is expected to

L3
Special cell and recording equipment used to measure the dielectric constant and dissipation factor in high polymers at very low frequencies. These

measurements, which are made down to liquid nitrogen temperatures, are a

part of the studies of the basic electrical properties of dielectric materials

(page 13). improve the military specification for resistors, since resistor noise

quality is not now included in the specification.

The Bureau is examining similar techniques for measuring the noise

generated by variable resistors. The knowledge provided by this program should suggest design improvements in these important electrical parts.

A Provisional Faraday Value. The Bureau is constantly striving to make increasingly accurate determinations of the constants of nature. One such constant which received particular attention in the past year

is the faraday, i. e., the number of coulombs or ampere-seconds required

to deposit or dissolve an equivalent weight of an element. This work

has now progressed to the point where a provisional value of 96,523

coulombs per gram equivalent on the physical scale may be given. This

value agrees within 1 part in 100,000 with an average value determined

by the omegatron and reported by the Bureau in 1953. However,

determination of the purity of the silver used in this work still needs

improvement.

Electric Cells at High Temperature. As a part of the Bureau's program to establish an electromotive force series of the elements at high temperatures, compaiisons of the potentials of zinc and bismuth in fused salts were made from 45° to 510° C. At 450° C the electric poten14
tial of zinc was observed to be 0.67 volt higher than bismuth. Zinc,

therefore, has a higher reducing power than does bismuth at elevated

temperatures. This work has been in large measure supported by the

Office of Ordnance Research of the Army.

Recharging of Dry Cells. Because of the pending exhaustion of the

world's supply of natural manganese dioxide ore for the dry cells employed

in flashlight, radio, and heariug-aid batteries, etc., the Bureau investi- gated the possibility of recharging dry cells whereby exhausted cells couid

be restored to initial full capacity. The Bureau has found that dry cells may be recharged by an a-c-d-c method several times, thus increasing

their ultimate usefulness. Internal Resistance of Dry Cells. For the first time, an unambiguous measurement of the internal resistance of dry cells was achieved.

Heretofore, it was believed that the internal resistance of dry cells changed

with the value of the current used in the measurement. By imposing a square -wave current pulse across dry cells for periods of microseconds

duration, the Bureau observed that the same value for internal resistance

of dry cells was obtained even when the current in the pulse was varied

widely. Also there was no change in the internal resistance of cells when

the direction of the pulse was reversed or when the frequency of the pulse was altered. Heats of Adsorption. A theory whereby the heats of adsorption of

gaseous metals on solid metals and of gases on metal can be calculated

from electrochemical data was formulated. Work functions, ionization

potentials, and the electron affinities of the materials all enter into the

theory. Results at room temperature agree within a few percent with

those found experimentally. The theory may also be used to calculate the hydrogen overvoltages on metals.

Aircraft and Missile Batteries. Under the sponsorship of the Navy

Bureau of Aeronautics, the Bureau investiga ted lead-acid, nickel

cadmium, and zinc-silver storage batteries at altitudes as high as 50,000

ft at — 10° F ambient temperature. For the unsealed types a study was made of the flooding of electrolyte under such conditions; flooding occurs imder abrupt changes in altitude but not under gradual changes. Studies were also completed on effects of position (angles of tilting), vibration

and thermal shock o i battery performance. The relation between charging currents, temperatures, and vicious cycling (overheating with

subsequent burning up or explosion) was investigated for all three types

of batteries. Missile batteries utilizing alkaline electrolyte have heretofore been believed to be adversely affected by atmospheric carbon

dioxide; the Bureau found that carbon dioxide does not cause deleterious

effects until 70 percent of the alkaline electrolyte is converted to carbonate.

Postal Automation. The Bureau is assisting the Post Office Department in studying certain aspects of methods lor handling mail b\ auto- matic machines. An experimental letter-sorting machine was developed,

15
and its operation is being analyzed to compare its performance with that

of other proposed sorting systems. Postage stamps of altered design to permit machine recognition were studied to find the most economical and

reliable design. Methods of coding address information on envelopes

(a dot pattern on a paper label attached to the envelope, for example) were also examined. And finally, the logical design of the mail-handling

machinery is being studied to determine the best way to store address

information in the machine and to modify this storage with changes in the frequency and distribution of the mail. (Additional work in the

mail-handling problem is discussed on page 77.)

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. Efforts are now being made to set up a primary

standard for recalibration of basic candlepower standards. Since color

is becoming an increasingly important factor in merchandizing, a method

has been devised for rapid color analysis with a high-speed electronic computer.

During the past year procedures for designating the metrical performance of an airplane camera lens were standardized. To assure the

maintenance of uniform length standards throughout the country,

methods for calibrating end gages have been further refined. Atomic

beam lamps that will produce coherent light over a maximum path

difference and interferometer equipment are being developed to facilitate the application of a new wave-length standard for length calibration. Photometric Standards. The International Bureau of Weights

and Measures, Sevres, France, proposed international adoption of uniform

units of candlepower and luminous flux for the carbon-filament lamp, the vacuum-tungsten lamp, and the gas-filled tungsten lamp. These units

are to be based on their average magnitudes found by applying the

primary standard of light (blackbody at the freezing point of platinum)

developed at the Bureau. The national standardizing laboratories of seven countries are participating in the effort. As this country's contri- bution to the program, the Bureau made the primary standard available

for continued routine use; completed a tentative recalibration of candlepower standards for carbon-filament lamps; and determined the ratio of luminous flux to candlepower for groups of vacuum-tungsten and gasfilled lamps. In addition, gas-filled, clear -bulb lamps commonly used as basic candlepower standards, were critically evaluated and found to be

deficient. Consequently, a gas-filled, frosted-bulb lamp with far superior

characteristics was developed by the Bureau in cooperation with a lamp

manufacturer.

16
Diagram (right) of equipment used to recalibrate the national candlepower

standards against the primary standard

of brightness, a blackbody radiator

maintained at the temperature of freezing gold (1,063° C). The photometric receiver used to make the comparison is shown above (page 16). Spectrophotometry Data Electronically Computed. Since 1931

the internationally accepted method of defining the color of any light has

been to specify the amounts of primary red, green, and blue light which

when added together produce a particular color. The fundamental

measurement of a color standard is the spectrophotometric determination

of the fraction of incident light transmitted or reflected by the standard

in successive parts of the visible spectrum.

To find the portions of red, green, and blue light required to match the

color of a standard, a computation is first made of the amount of the

standard's transmitted or reflected light for each part of the visible spectrum. This amount is then multiplied by the known portions of

red, green, and blue primaries required by the average human observer

to match a particular segment of an equal-energy spectrum, and the

products are added together.

Each of these computations, made for years with a desk calculator,

required half an hour. Last year, the work was programed for the Bureau's electronic digital computer, which automatically corrects any

photometric scale errors of the spectrophotometer and completes the

computations in only a fraction of a second for each color standard.

Conversion of Colorimetric Data to Munsell Terms. During the

past 30 years the Munsell scales of hue, value, and chroma have been

widely used by American science and industry for color and color tolerance

specifications. These scales have an almost uniform perceptual spacing,

and they closely correspond to the hue, lightness, and saturation of a color perceived under daylight viewing conditions. In addition, they

are defined in terms of the internationally accepted tristimulus values

(amounts of primary red, green, and blue required to produce any color).

These scales are generally preferred because the colors can be readil) visualized.

OPTICAL PtMWETfP

IT
Finding the Munsell notation of a color expressed in tristimulus values

requires a tridimensional interpolation among the 5,000 points denning

the Munsell scales, and a verification by means of tables and graphs.

Since this work takes about 20 min for each color, it was also programed

for the Bureau's electronic digital computer. By scanning a tape

carrying specifications of the 5,000 defining points until a color's 8

limiting points are located, and then by determining the Munsell hue,

value, and chroma through linear interpolations, the computer finds the

Munsell notation in 20 sec. Anticollision Lights for Airplanes. Today's heavy air traffic with

its attendant mid-air crashes points up the need for evaluation of the

anticollision lights now installed and proposed for installation on air- planes. The Bureau made such an evaluation for the Navy Bureau of

Aeronautics under controlled experimental conditions. The Navy

cooperated in designing tests for the evaluation of lighting systems under

actual flight conditions. Experimental results brought into focus the

characteristics essential to an effective lighting system. In a separate phase of the work a new type of emergency exit light for aircraft was developed. This light employs self-contained incandes- cent light sources that transilluminate a phosphor-coated panel with

exit designations. After a power source failure the panel remains visible for about a 10 -min period.

Half-scale rotatable mockup, representing the fuselage and wings of a DC—3, used to evaluate aircraft anticollision light systems. The three complete

light systems on the boom can be rotated to present different headings of the

plane to observers, who are stationed 1, 3, and 7 miles away (page 18).

18
Refractive Index of Synthetic Sapphire. Synthetic sapphire in- dices of refraction for the ordinary ray, N , were measured over almost

the entire range of transmission (0.2 to 6.0 microns) at controlled room

temperatures near 19° and 24° C. Thermal coefficients of index were computed for each wavelength, and all data were reduced to exact temperatures of 19° and 24° C. Also, refractive indices and thermal

coefficients for 7 visible wavelengths were determined at 17°, 24°, and

31° C. Sapphire was found to have a large reciprocal dispersion for the index

of refraction, and there was also evidence that the thermal coefficient of

index decreased with increasing wavelength. It appears that the extended

wavelength transmission region and unusual dispersion will make sapphire

a valuable material for optical instrumentation.

Calibration of Airplane Cameras. At the request of the Air Force,

a thoroughgoing analysis of random errors that affect the accurate

calibration of airplane cameras was completed. Factors studied include camera tilt, plate curvature, and prism effect. Of these, the mos

pernicious is prism effect since it produces radial asymmetric and tan

gential distortion of a type that cannot readily be compensated. Experiments conducted in the course of the investigation showed that various

corrective methods may be employed to eliminate the random errors when

they become apparent. However, lenses showing an excessive amount

of prism effect should not be used for precise photogrammetric mapping.

Standards for Spectacle Lenses. Prescriptions for spectacle lenses usually specify only the power at the center of the lens and not that near

the edge or margin. In an attempt to insure 20/20 vision from all parts

of prescribed lenses, the axial and marginal powers of about 300 lenses from 5 different manufacturers were measured. Tolerances based on the

results will be used by the Veterans Administration in purchasing

ophthalmic lenses. Of the lenses tested, 80 percent gave acute vision near the margin of the lens. Automatic Lens Design. The Air Force sponsored a study for coding a high-speed digital computer to design lenses automatically.

First a method was developed for using a single number, called t In- optical merit function, to describe the quality of a lens. A routine was

then devised for improving the optical merit function on the electronic

computer. In a sample run, some of the geometric aberrations of a triplet lens were reduced, demonstrating the feasibility of automatic design

techniques. A great deal of time-consuming work may now be eliminated

with computers adjusting a given design to its optimum.

Atomic Beams for Defining Length. By applying atomic beam

techniques, extremely monochromatic optical radiations (A =2537 A) were produced. The band widths of these radiations are one-fourth as wide as the narrowest lines conventionally produced, thus interference can be observed over a path length exceeding 2 meters with a precision

of 1 part in 109

. 19
As part of an effort to meet industry's

demand for gage blocks accurate to

1 part in 10 million, two novel type

interferometers were designed. The

one above determines the parallelism

of the ends of long gage blocks, and

the other, right, tests the parallelism and optical planeness of gage

blocks up to 4 inches in length

(page 20). An emission beam source utilizing natural mercury has also been tested

and found quite satisfactory within the limits imposed by natural mercury.

A revised version of this source will be filled with isotopic mercury and

tested in the near future. Another atomic beam device that has given good results in preliminary

tests employs the absorption line of mercury at 2537 A. The device

serves as a detector, sensitive to radiations over only a very narrow band

or curve. The wavelength of this narrow and precisely defined sensitivity curve can be used as a definition of the meter. A third instrument,

developed dming the past year, utilizes a properly balanced Michelson

interferometer. The device, now being tested, produces an emission line from an absorption process in an atomic beam of mercury.

High-Precision Gage Blocks. In the high -precision gage block pro- gram, supported in part by American industry, emphasis is shifting from

the development of improved calibrating instruments to the development

of more precise gages. An ideal gage would be unchanging in length,

but almost any material will gradually grow or shrink with time. To

detect the small changes that occur in a relatively short period a method

was developed by which comparisons accurate to approximately 1 part in 10,000,000 are achieved. The method, providing measurements 10 times more precise than any previously attained, is being used to study the

relative desirability of various steels for gage construction, and to deter- mine the coefficients of thermal expansion of these steels (see page 54). In one phase of the program a design was completed for a new inter- ferometer to measure lengths in terms of a wavelength of light to a part

in 10 million. An extensive study was undertaken of phase change of

light in reflection. This change is a source of error in interferometric

length measurement necessitating corrections. The group of manufacturers working in cooperation with the Bureau

are the Dearborn Gage Co., DoAll Co., E. I. du Pont de Nemours & Co.,

20
Fonda Gage Co., lac, General Electric Co.. Greenfield Tap & Die Corp.,

Hughes Aircraft Co., International Business Machines Corp., Link

Aviation, Inc., New Departure (General Motors), Pratt & Whitney Co.,

The Sheffield Corp., Taft-Peirce Foundation, Timken Roller Bearing

Co., and the Van Keuren Co. Screw Thread Standards. Part I of NBS Handbook H28 (1957),

Screw Thread Standards for Federal Services, was published and the original

supply of 13,000 copies was quickly exhausted. However, a 17,000-copy

reprint recently came off the press. Part I established standards for screw threads to be applied to bolts, screws, nuts, and tapped holes used

by government departments. Part II, providing standards for pipe

threads, hose -coupling threads, and related items, is being published. Part III will include standards that are in the process of formulation by

Government and industry, such as acme and buttress threads; publication

date has not been fixed. It is anticipated that part I will have to be

revised when current negotiations for international standardization of

threads are completed.

2.3. Heat

To provide a basis for precise measurements of heat, the Bureau maintains temperature scales covering most of the range of accessible temperature, and continually develops and extends these scales. In addition,

standards are determined and maintained for viscosity, for engine -fuel performance, and for heat measurements such as thermal diffusivity,

heat capacity, and heat of combustion.

A broad program of basic research in i elated areas is being conducted

to extend these heat standards. Fundamental studies are carried out in heat measurements, statistical thermodynamics, molecular structure, high- pressure thermodynamics, low-temperature physics, rheology, and hightemperature processes. Special emphasis is given to research on free radicals in an effort to determine the properties of the solids which contain

appreciable quantities of trapped reactive radicals. 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

statistical thermodynamics of dense systems, and to study the mechanisms of high-temperature processes with greatly improved

instrumentation.

Statistical Thermodynamics. The continued advancement of sci- entific and industrial activity to the extremes of temperature and pressure has thrust more and more responsibility on theoretical methods for describing the thermodynamic and transport properties of substances.

To extend these data a program of statistical thermodynamics is being

directed toward the development of new theoretical techniques for describing these properties.
Significant progress was made during the past year both in the development and application of theoretical methods to such problems as quantum

effects on surface tension in simple liquids, isotope effects on the compressibilities of isotopic hydrogens, statistical mechanical description of the

transport, equilibrium, and magnetic properties of electron gases, molecular orbital calculations of the H3 molecule, and partition function repre- sentation for atoms and atomic ions to a million degrees, and molecules

and molecule ions to 25,000° K.

Basic thermodynamic data are required for engineering calculations

encountered in the design and performance evaluation of such equipment

as gas turbines and jet and rocket engines, and in the solution of various

aerodynamic, astrophysical, and astronautical problems. To extend

such data over a wide range of temperature and density, high-speed

computation programs were designed. Codes are being applied to a systematic generation of extensive tables of ideal-gas thermal functions

of atoms, molecules, and their ions. They also cover equilibrium compositions, and thermodynamic and transport properties of complex mixtures

of reacting gases. International Temperature Standards. Temperature is generally

accepted as one of the fundamental quantities necessary to describe

completely the physical state of matter. So that all measurements of

temperature in different laboratories have the same basis, an International

Temperature Scale has been developed which has been generally ac- cepted by all nations. In the temperature range from —183° to 630° C,

the scale is fixed by the use of a suitable platinum resistance thermometer

calibrated at the normal boiling points of oxygen, water, and sulfur, and

at the ice point. A primary function of the Bureau is to improve and

extend the ITS in the United States and to develop instruments for the

practical utilization of the scale. To insure that all laboratories throughout the world are realizing the same temperature scale, occasional international comparisons are made.

This is accomplished by the exchange or circulation of standard platinum

resistance thermometers. Such a check was made over the past 5 years

to determine the uniformity of the accepted steam point. Three ther- mometers were sent to the national laboratories of Great Britain, Germany, the Netherlands, Russia, Japan, Canada, and the United States. Results indicate that the same steam point is realized in these countries

to within 0.001 deg C. A similar but somewhat less extensive check was made between the

Bureau and the National Research Council of Canada in connection

with the realization of the primary fixed point at the normal boiling

point of sulfur. This check indicated that the temperature realized as the sulfur point is in agreement within 0.002 deg C. Considerable effort was also expended in the important task of re- writing the text of the International Temperature Scale. Revision of

the 1948 text was done in order that this document reflect both recent

22
actions of the International Committee on Weights and Measures and

recent improvements in techniques. Although the text of the scale was

favorably received by the Advisory Committee on Thermometry and

Calorimetry in June 1958, some further revision will be necessary because

of the new proposed replacement of the sulfur-boiling point by the zinc- melting point as a fixed point of the scale. Resistance Thermometry. To provide additional facilities for temperature calibrations and related work, new equipment was installed in the resistance thermometry laboratory. One addition is a multiplereflection galvanometer which utilizes multiple reflections from a moving

galvanometer mirror, thus increasing the instrument's sensitivity in measuring resistance by a factor of 4. Other new equipment includes a potentiometer, which measures the current through the resistance

thermometer with an accuracy of 1 part in 5 thousand. This is necef/sary in order to measure and control the heating effect of this current. In

addition, a control device automatically maintains the pressure of specific

equipment at about 1 atmosphere, constant within 1 part in 10 million. High-Temperature Pyrometers. In research at very high temperatures, work is in progress to improve the accuracy of pyrometer calibra- tions at temperatures between 2,500° and 4,000° C. During the past

year, zirconium and carbon arcs were adapted for use in the calibration

of pyrometers which now permit direct observations up to about 3,800° C. However, because the instability of these sources limits the accuracy of

In an effort to extend and improve its temperature measuring capabilities,

the Bureau developed this photoeleetric pyrometer for temperatures above

1,000° C. Greater precision is possible than with the optical pyrometer

presently in use (page 23).
routine calibration to about 40° at 3,800° C, attempts are being made to develop a more stable source for this temperature region. One promising

design consists of an electrically heated graphite tube mounted in an

inert gas atmosphere. The first model was constructed, and studies on the effect of size, mounting, and gas pressure as a function of stability are being planned.

Parity and Time Reversal. The original NBS experiment in 1956,

indicating that parity was not conserved in beta decay, stimulated an enormous amount of research in other laboratories throughout the world

engaged in the basic fields of weak interactions and fundamental particles i of matter. Investigations at the Bureau were made on the directional

asymmetry of emission of beta particles from polarized nuclei of Co60

, Co08

, Co°6

, and Mn52 and the angular correlation of these beta particles i with following gamma radiation. All of these experiments gave information on the dynamical details of the beta interaction and, in particular,

information on the question of time reversal invariance in beta decay.

It is now apparent that invariance under space reflection (parity conser- vation) and invariance under charge conjugation are both violated to a maximum, while invariance under time inversion—time symmetry in

j subatomic interactions—is not. Experiments are proceeding to ascertain

whether time reversal invariance is actually exactly conserved.

These experiments involve a study of the emission pattern of radioactive manganese-52. This radioactive disintegration includes the

simultaneous emission of a beta particle (or electron) and a neutrino from

the manganese nucleus. Making use of theoretical work by previous

investigators, Bureau scientists developed a technique by which they can

determine the relative proportions of the emitted beta particles which

have a spin either in the same or the opposite direction as that of the

neutrino emitted at the same time.

Besides giving information of fundamental nature, experiments on the

beta decay of oriented nuclei also give considerable information on the

details of nuclear quantum states and thus afford a powerful new tool for the study of the nucleus. Heat Measurements on Sulfur. Because sulfur is of basic importance in the chemical, rubber, and petroleum industries, data on its thermodynamic properties will aid in the theoretical interpretation of

the complex behavior of the element as well as in predictions of the

reactions of sulfur and its compounds at higher temperature—-such as occur in petroleum refining. Although sulfur has been known since ancient times, accurate thermodynamic data has been limited because it

is difficult to purify, exists in several crystallographic forms, and reaches

equilibrium slowly. For example, the liquid form consists of sulfur atoms

in different molecular combinations ranging from 8-atom rings to 10,000-

atom chains. As the temperature is raised, the concentrations of the

various molecular species change slowly, causing corresponding shifts in the thermodynamic properties. However, accurate measurements

24
Experimental equipment used in continuing studies in low-temperature

physics relating to parity and time reversal (page 24). of the heat capacity, which allow for changes in the molecular species at each temperature, were completed by the Bureau in a project partly

supported by the American Petroleum Institute and the Allied Chemical

Corporation. The measurements were made with 99.999 percent pure

sulfur in a high-temperature adiabatic calorimeter designed especially

for such substances.

Thermodynamic Properties of Rubber. In the development of

synthetic rubbers and associated polymers for industrial use, accurate thermodynamic data are needed to calculate maximum efficiency and

yield of chemical production processes, and to predict thermodynamic

properties of related polymeric substances. To determine these data,

the Bureau completed a long-range project, sponsored by the National

Science Foundation, involving the thermodynamic properties of rubber

polymers. Experimental and theoretical research dealt with the basic raw materials, the intermediates from which the polymers are made,

and the rubber polymers themselves. Results were combined with

data from previous measurements to obtain the thermod) aamic properties

of the system.

Viscosity Standards. To test the suitability of ra-hexadecane

(cetane) as a calibration standard for viscosity measurements, a stud) of the viscosity of cetane purified by several techniques was completed

25
by the Bureau. Although water is the material almost universally used

for this standard, an additional calibration standard has long been

desired because of the difference in surface tension between water and

hydrocarbons. Therefore, a few years ago, the Bureau was asked by

the Society of Rheology to undertake this study, with cetane suggested as

a possible hydrocarbon.

Because of the range of purity of the samples measured—from 93.6 lo 99.94 mole percent— the viscosity of the sample varied irregularly over a range of 0.18 percent. Without the exact composition of a given sample,

and without more information on the variation of viscosity with composition than is now available, cetane could be relied on as a calibration

standard only if an elaborate purification procedure was first performed.

Thus it appears more feasible to continue using water as the standard,

making the lequired surface tension corrections. Rheology. To widen the range of basic knowledge on the deformation

and flow of such polymers as lubricating greases, synthetic rubbers, and

motor oils, the Bureau has been studying the rheological properties of polymers. One of the investigations this year concerned a modification

of a theory which gives the time -dependent mechanical response of a rubberlike polymer in terms of its molecular properties.

A number of equivalent theories have been developed to give the timedependent response of such polymer systems by combining the kinetic

theory of elasticity and a theory attributing viscosity of polymers to the entanglements of long chains. While these previous theories introduce

the effect due to entanglements by calculating the total response in two

arbitrarily separated parts, the present modification includes all the

observed effects in a single model. By applying this theory, extremely

close reproductions of experimental results were obtained. The calcu- lated and observed values—using constants appropriate for the "standard" polyisobutylene—show exactly the same behavior qualitatively,

and over most of the range the quantitative agreement is within the experimental uncertainty.

Free Radicals. For some time there has been considerable interest

in the study of free radicals because knowledge of the properties of these

highly reactive molecular fragments is valuable in basic research as well

as in certain areas of applied physics and chemistry. Therefore, the

Bureau, under the sponsorship of the Department of Defense, is conducting a large scale program devoted to free radicals. One way of classifying

the numerous projects concerning free radicals is by dividing them into

the broad categories of preparation, characterization, and application.

Preparation. Since stable molecules may be transformed into re- active free radicals by breaking chemical bonds, researchers are studying

techniques of electric discharge and thermal dissociation of the gas phase

followed by condensation, or electron bombardment and photolysis of

the solid phase with gamma rays and ultraviolet radiation. To trap the

free radicals for convenient study, the reactive substances are collected

26
A comprehensive program is directed toward charting the properties of free radicals. (Above left) Transferring liquid helium through an evacuated

siphon to the refrigerated tube of the apparatus used to collect free radicals. (Above right) Condensing nitrogen atoms (produced in electric discharge, center of picture) on the liquid helium refrigerated tube (upper center of

picture). Inset shows glow of radicals condensed on the tube. (Below left) Apparatus for measuring energy losses of bombarding electrons passing

through a free radical condensate. (Below right) Equipment for X-ray

diffraction studies of solids containing free radicals (page 26).
immediately after production b} freezing on extremely low-temperature

surfaces. Because each method of production is useful for a specific

type of experiment, the over-all investigations are needed to evaluate

the effectiveness of possible preparations.

Characterization. X-ray diffraction techniques are used to deter- mine the structure of the solid lattices which contain trapped radicals. In many cases, these structure determinations on a particular materia]

are the first to be made at low temperatures (as low as 1°K). Identifica- tion of the frozen radicals by means of electron spin resonance and optical

spectroscopy from the vacuum ultraviolet to the infrared has demonstrated that such unusual species as N, O, H, OH, and HNO may be

stabilized for long periods at low temperatures. The quantity of radicals trapped by these techniques is very important in understanding the nature of forces holding the radicals in the solid matrix, but the measure- ment of radical concentration in such systems ib extremely difficult. However, some estimates of concentration are now being made by such

methods as calorimetry, electron spin resonance, and magnetic susceptibility. Other properties of the solids such as electrical and thermal

conductivity, dielectric constants, and index of refraction are also being

studied.

Application in Chemical Processes. A number of these studies

involve the type of reactions that may proceed in solids containing atoms

or radicals as a function of the nature of the solid. One investigation

resulted in the production of ozone from oxygen radicals in yields of

nearly 100 percent while another resulted in the direct preparation of

radicals in the solid by addition of hydrogen atoms to condensed hydrocarbon molecules. By studying the latter controlled production, uncertainties of associated reactions can be eliminated.

Finally, it was found that the deposition of magnesium vapor in a suitable matrix produces a red transparent solid quite different in appear- ance and behavior from the metallic magnesium deposit customarily

obtained by condensing the vapor. This form of magnesium, which is stable only at very low temperatures, is not only indicative of a new form

of a familiar substance, but is also representative of a potential means

of storing energy. (See also pages 29, 38.) 2.4. Atomic and Radiation Physics

The rapid rate with which basic discoveries in atomic and nuclear

physics are being applied to practical problems in technology places an

ever-increasing demand on the Bureau for services and information.

Industry a/id the medical profession, as well as research institutions and

government laboratories, require new and more accurate data on basic

properties and fundamental reactions, new techniques and more reliable methods of measurement, and new as well as improved standards.

To meet these needs, research, development, and standardization

programs are carried out in such areas of modern physics as the properties
of particles (atoms, ions, nuclei, electrons, neutrons, and photons for example) and the interactions of particles with each other and with electric and magnetic fields. The aim of this basic research program is to provide

a clearer understanding of the individual properties and fundamental

laws governing the behavior of particles in order to discover new and

better ways for control and measurement. These data in turn lead to more accurate and reliable units and standards.

Solid state physics, which probes the nature of solid materials; spectros- copy, which investigates the atom; and radiation studies, which provide

data on fundamental particles and nuclei, as well as atoms; are important

phases of the program.

Spectroscopic Research. Analysis of the light emitted by atoms and

their ions is an accurate and widely used method for obtaining detailed

information on atomic structure and chemical composition. The wavelengths are measured by interpolating between values of iron lines cali- brated in terms of cadmium radiation. HoAvever, because of the high

temperature of the iron arc, its operation at atmospheric pressure, and

the relatively small mass of iron atoms, the spectral lines are unduly

coarse and wide. Moreover, the nature of the iron spectrum prevents

the selection of uniform standards evenly distributed throughout the

spectrum. Because the iron standards are inadequate for modern precision measurements in complex atomic spectra, the Bureau has substi- tuted the green radiation from mercury 198 as a primary standard and

a thorium-halide lamp as a source of secondary standards lines. Because

thorium atoms are more than four times heavier than iron atoms and

emit lines entirely free from hyperfine structure and isotope shifts, they

yield spectral lines about one -tenth the width of iron lines. Furthermore,

thorium spectra contain four times as many lines as iron, permitting the

selection of uniformly distributed standards of superior quality.

Preliminary measurements of 222 thorium wavelengths ranging from

3287.7885 to 6989.6562 A in standard air were presented to the Inter- national Astronomical Union. The error in relative value of these meas- urements is less than 1 part in 20 million. Free Radicals Studies. Mass spectrometric methods were used to obtain information on the mass and energy states of free radicals, as part

of a general research program on radicals (see p. 26) sponsored by the

Department of Defense. The concentration of nitrogen atoms and their recombination in the nitrogen afterglow were measured in this way by the use of a specially designed flow system. A technique was develop"*

which employs nitric acid to "titrate" the nitrogen atoms formed in a high-frequency discharge. It was thus possible to measure the rale at which nitrogen atoms recombine by collision with nitrogen molecules, by

collisions with rare gases, and by wall collisions. Other mass spectroscopic studies were conducted on hydrazine and the methyl hydrazines, which are of scientific interest and of practical value

as high-energy fuels for rockets and missiles. Until recent l\ little was
Nuclear magnetic resonance offers a tool for the investigation of the solid

state. A study of the absorption of energy by atomic nuclei in solids provides

a better understanding of the local electric and magnetic fields that the nuclei

experience (page 30). known concerning their molecular-bond strengths and other thermodynamic properties. Ati investigation of the ionization and dissociation processes following electron bombardment afforded deta^ed information on the bond strengths and heats of formation of radicals for the hydrazine

compounds.

Behavior of Semiconductors. The increasing industrial use of

semiconducting devices, such as rectifiers and transistors, along with the

present interest in employing semiconductors as infrared photodetectors

and thermoelectric generators, emphasizes the need for a better understanding of the unusual mechanical and electrical properties of these

solids. To meet this need, studies on the behavior of materials such as the intermetallic InSb are being continued and new materials are being

investigated. Experiments on the intermetallic InAs for example, showed

that its galvanomagnetic properties are similar to those of InSb. Both

exhibit a magnetic field dependence in which the resistance as a function

of field strength shows oscillatory behavior at liquid -helium temperatures.

A study of the theory of such an effect clarified understanding of the phenomenon, which is closely related to the DeHaas-Van Alphen effect. Other behavior studied is the temperature dependence of the spin relaxa- tion time in NaCl. This investigation and similar work underway on

AlSb was made possible by recently completed equipment for the measure- ment of nuclear magnetic absorption and relaxation times. In addition to the behavior of semiconductors, their basic nature is investigated by obtaining data on the mechanical properties of the

crystals. In this research, supported by the Air Research and Development Command, piezoelectricity was observed at liquid-helium temperatures in InSb.

30
Electron Polarization. The Bureau has developed apparatus for the production of photoelectron beams from thin ferromagnetic film,

and for the detection of spin polarization in these beams. The detection

system constructed makes use of the asymmetric properties of Mott

scattering at 120 kev. With this instrument new information was

obtained concerning the critical thicknesses of metallic target foil needed

for the measurement of spin polarization.

Scattering of Low-Energy Electrons. In a program jointly sup- ported by the Atomic Energy Commission and the Bureau, a detailed

study of low-energy electron scattering was pursued. Particular emphasis has been placed on the characteristic energy losses of electrons in

solids. To facilitate this work two high resolution spectrographs were put into operation. One is capable of high resolution in both energy and

angle, and the other—designed to work at liquid helium temperatures

measures only in the forward direction with high resolution. Angular

distribution measurements were made of a number of new substances, the

effect of crystal orientation and aggregation on the energy -loss spectrum was investigated, and a thorough study of the character of the energy -loss scheme in sodium is in progress. In addition, temperature dependence

of the energy loss in aluminum was noted as part of low-temperature

experiments. Measurements of the energy losses of electrons in con- densed gases are presently underway.

Proton Gyromagnetic Ratio. The gyromagnetic ratio of the pro- ton—a measure of its interaction with magnetic fields—was redetermined

with significant increase in accuracy. This result not only provides a better standard for magnetic fields but also makes possible more accurate

values for many of the fundamental constants of physics whose values

depend upon magnetic field measurements. Examples are the electron charge-to-mass ratio e/m, the magnetic moment of the proton, and

Planck's constant h. The new value for the proton's gyromagnetic ratio will be especially useful in the design and development of scientific and industrial apparatus

in which it is important to know accurately the spatial distribution of a magnetic field or to regulate it closely. Here the proton can be used as

a very sensitive probe to determine magnetic intensity in terms of the precisely known gyromagnetic ratio. Problems of this sort arise widely

in the use of scientific apparatus—cyclotrons, mass spectrographs, and

beta-ray spectrometers—and in industrial equipment such as servo mechanisms and electromagnets. In the method used for the redeter- mination, the hydrogen protons in a water sample are caused to precess in a magnetic field, and the precession rate is obtained from (lie frequency

of the voltage induced in a pickup coil surrounding the sample. The

gyromagnetic ratio is then obtained as the ratio of tlie angular precession

frequency to the field strength.

Increased accuracy was obtained by using a magnetic field thai can be calculated to very high precision. This field was produced b) an accu- 31
rately measured current flowing through a solenoid whose important

dimensions are known to one part in a million. To avoid the interfering

magnetic fields from nearby objects, experiments were performed at the

Fredericksburg Magnetic Observatory of the U. S. Coast and Geodetic

Survey.

Rubidium Vapor Magnetometer. A simple, accurate magnetometer suitable for measurements of the earth's magnetic field was constructed. It utilizes resonance absorption lines in rubidium vapor. This project was undertaken in cooperation with the Fredericksburg

Magnetic Observatory of the U. S. Coast and Geodetic Survey. Measurements made with the instrument show that the International Magnetic

Standard, in terms of which almost all earth's field measurements are made, differs from the absolute unit by 1 part in 10 thousand.

Structure of Negative Ions. The photodetachment method devel- oped at the Bureau for the Office of Naval Research for studying the

structure of negative ions was refined and its accuracy substantially

improved. Careful measurements of the photodetachment cross section

for the atomic hydrogen negative ion, H~, now provide an experimental

evaluation of several theoretical studies of H~. The photodetachment

method also gave an unambiguous and accurate determination of the

energy-level structure of the oxygen negative ion, 0~. This accurate measurement of the 0~ photodetachment spectrum provides information

of great value for theoretical studies of electron-oxygen-atom collisions. The results of these studies are applied to astrophysical and other hightemperature phenomena as well as ionospheric phenomena.

Neutron "Age". The second of a series of experiments, supported

by the Atomic Energy Commission, on the penetration of neutrons in water was completed. This experiment measures the "age," or one -sixth of the mean square of the crow-flight distance that fast neutrons travel while being slowed down to a particular energy. The age of 2 to 3.1 Mev neutrons from the (deuteron-deuteron) reaction for slowing down

to indium resonance energy was measured. The result agrees with

theoretical calculations, and is of particular interest because the energy

of these neutrons is near the average of the energies of fission neutrons. For a number of years, there has been a discrepancy of about 20 percent

between the experimentally measured age of fission neutrons in water and

the age obtained from theoretical calculations. The agreement of this experiment with theory seems to indicate that the souice of the discrepancy is in the experimental value for the age of fission neutrons in water,

and not in the theoretical calculations. Phosphor-in-Plastic Fast Neutron Detectors. Both the speed

and efficiency of a widely used scintillation method for neutron detection

are improved by substituting organic plastic scintillators for the inorganic

phosphors previously used as indicators in plastic buttons. The use of

organic plastic scintillators in the plastic medium yields a transparent

button which can be made much thicker and therefore about 10 times

32
Experimental setup for studying neutron slowing down in water. The ex- periments have shed light on the discrepancies that exist between theory and

experimental values for the "age" of fission neutrons in water (page 32). more efficient than the older type of button. The new button has advantages for many problems in neutron detection and also shows potentialities for use as a neutron dosimeter for all neutron energies.

Penetration of Gamma Radiation. In a continuing program sup- ported jointly by the Department of Defense, the Federal Civil Defense

Administration, and the Atomic Energy Commission, the penetration of

gamma radiation through matter was studied theoretically and experimentally. Results of this work will aid the development of suitable

shelters against radiation from nuclear weapons, particularly fallout gamma radiation. The theoretical work resulted in large scale tabulations of basic penetration data, while the experiments, carried out at the

Nevada proving grounds, provided a measure of the penetration of fall- out-gamma radiation through concrete. Gas Radioactivity Standards. The first gas radioactivity standards were prepared and distributed, and counting equipment for emitters in gaseous form was constructed. The precision of results obtained with

this type of counter makes a recalibratio i of the Bureau's carbon- 1 I standards desirable. This will be accomplished by counting, the C

14 nuclide in the form of the gas carbon dioxide. A redetermination of tlic half-life of C

14 will also be performed in this way.

X-ray Studies. In the investigations of X-rays produced willi electron energies between 0.05 and 50 Mev, data was obtained for the energy and angular distribution and for the polarization of the X-ra\s

as a function of electron energy and target material. Special attention was given to the high-frequency limit of the X-ray spectrum, where il

:;3
has been possible to obtain good agreement between experimental results and theoretical predictions where no predictions existed previously.

Detailed studies of the X-ray production process are now under way in order to obtain accurate information about the angular distribution of

the recoil electrons and about various polarization effects that occur in the process. The goal of these studies, supported by the Atomic Energy

Commission, is to obtain experimental data which can be used to describe

X-radiation under any set of experimental conditions and to check theoretical predictions. Such descriptions are becoming increasingly important because of the wide application of X-rays as a basic tool in modern

science and technology.

Nuclear Structure. Research supported by the Atomic Energy

Commission has yielded information about the structure of the nucleus.

For example, the photoproduction of ir° mesons from carbon was found

to give a measure of the nuclear matter distribution within the carbon

nucleus. The radius of the nuclear matter distribution calculated from

these measurements is in good agreement with the radius of the electric charge distribution calculated from electron scattering experiments. In other work, measurements of the partial cross section (in energy and

angle) for the photon induced emission of protons from carbon, leaving

the residual boron nucleus in its ground state, indicate considerable

photon absorption by quadrupole and higher modes. The measurements

will provide a sensitive test of nuclear wave functions. In experiments

measuring the photoneutron yields from different nuclei, a correlation was established for the first time between the photoneutron yield and the

deformation of the nuclear surface. For a highly deformed nucleus like tantalum, the giant resonance is actually split into two resonances—a fact which has opened up an entirely new approach to the study of intrinsic nuclear quadrupole moments. Correlated measurements, supported by

the Air Research and Development Command, showed that the elastic scattering of photons from tantalum can be understood only by considering the tensor nature of the polarizability of a highly deformed nucleus.

Radiation Absorption. Accurate measurements of the total radiation absorption coefficients between 15 and 90 Mev in carbon, oxygen,

and aluminum revealed the need for corrections of from 1 to 5 percent

in existing pair, production calculations. These measurements, sponsored

by the Air Research and Development Command, also provide a sensitive measure of nuclear absorption cross section. Direct calorimetric measurements of absorbed dose are now possible.

A study, which employed a Co60 source, gave results in good agreement

with the absorbed dose calculated from ionization measurements.

X-ray and Gamma-ray Dosimetry. To provide a better understanding of the processes occurring in photographic film when used for the measurement of radiation, reversal studies were conducted with

weak surface developers. The results so far indicate that reversal with

X-rays always decreases with increasing exposure rate, as it does with

34
visible light. Further investigations in the reversal region were made

with mixed X-ray exposures leading to different rates of energy absorption

in the emulsion.

Silicon solar photocells were investigated in order to test their suitability for dosimetry of X- and gamma-radiation. These photovoltaic

cells, when irradiated, produce a photovoltage causing an electric current

in an external circuit. As silicon has a smaller absorption of X- and

gamma-rays than other semiconductors used in photovoltaic cells, its sensitivity is lower but depends more favorably on the energy of the inci- dent photons. The decrease in sensitivity, due to smaller absorptions, can be easily offset by increasing the sensitive area of the cell. 2.5. Chemistry

The Bureau's program in chemistry includes a wide range of activities

in both basic and applied research. Representative activities during the

past year in inorganic, analytical, organic, and physical chemistry centered

around investigations of analytical methods, development of sensitive

criteria for purifying substances and determining their purity, analysis of gas mixtures, automatic high-speed analysis by spectrometric means,

studies on mechanisms of electrodeposition and the electrochemical

behavior of ion-exchange membranes, determination of chemical constants and the tabulation of scientific data, synthesis of carbohydrates labeled with radioactive atoms, and production and certification of standard

samples. These activities were carried out in laboratories that studied

organic coatings; organic reactions; preparation, purification, and analysis

of materials; electroplating; properties of molecules and electrolytes; gas

reactions; surface chemistry; thermochemistry; and spectrochemistry.

Analysis of Small Amounts of Tungsten in Steel. To meet the

continual demand for highly accurate methods of analysis and for chemical

compounds of unusually high purity, the Bureau conducted numerous

projects on purification.

Tungsten in proportions of 2 percent or less is finding increasing application as an alloying element in ferrous metallurgy as it provides improved durability, hardness, and high-temperature properties in steels. Because of tungsten's widespread use, a procedure for detecting its presence and checking for quality control was needed. Therefore the

Bureau developed a new photometric method for determining small

quantities of tungsten in steels and titanium alloys. This method

involves the use of dithiol reagent (l,2-dithiol-4-methyibenzene), which

eliminates metal interferences by forming easily isolated metal complexes.

Following the removal of these interfering elements, a clear blue tungsten

dithiol complex is formed. This complex is extracted in butyl acetate and its absorbancy is then measured in a pholometer to determine the

percentage of tungsten present.

Another photometric method—flame photometry was successfully

applied to the determination of sodium, potassium, calcium, and strontium

in the presence of other alkali and alkaline-earth ions. 35
Purification of Titanium Halides. Extensive research on the preparation and purification of various titanium halides was carried out at the

request of the Office of Naval Research. The thermodynamic properties

of these halides are also being studied in order to evaluate methods for the extraction and refining of titanium. Because titanium has excellent corrosion resistance and a high strength-to-weight ratio, it is considered

a promising structural material for aircraft and guided missiles and for applications involving severe corrosive conditions.

To prepare pure titanium trichloride from titanium tetrachloride, a new procedure which eliminates the necessity of sublimation was de- veloped. The process is based on the reduction of TiCl4 in the vapor state by hydrogen. The apparatus is, in effect, made of one large piece of

glass with the various components sealed together. No ground joints are used, thus avoiding the interfering reaction of hot TiCl4 with anv

lubricating grease put on such joints. Then too, by evacuating a sealed system and removing all air and moisture with heat before the addition

of the TiCl4 , air is prevented from contaminating the starting material.

Thus no oxygenated compounds are formed, and the long, drawn-out

process of sublimation—which is necessary to remove any interfering

oxygenated compounds—is bypassed. Although the conversion yield by

this method is fairly low, the recovered TiCl4 can be reused for other runs. Evaluation of Purity. As part of the program of supplying standard

samples of high, known purity, a reliable determination of the degree of

contamination is essential. Although this has been accomplished by

measuring the change of temperature when samples freeze or melt, the

procedure required constant manual control, and results were therefore influenced by the inability to record continuously. Now, automatically

controlled equipment has been designed, eliminating most of the observer

participation.

Spectrographs Determination of 18 Elements. For rapid spec- troscopic determination of 18 elements simultaneously, a unique electronic

read-out system was placed in operation. With this system, measure- ments of the concentrations of elements are made electronically and the

results are printed and punched on IBM cards. The cards subsequently

are fed into a high-speed computer for statistical analysis of the data. After the sample is inserted, operation of the spectrometer is automatic.

The spectral exposure is made for about 30 seconds after which the data

of intensity measurements for the 18 elements are read into an electronic

storage unit in 5 seconds. Five seconds later, the results are printed and

punched on an IBM card. This fully automatic unit—the first of its kind—is being applied to the study of metals and alloys for homogeneity

prior to their acceptance as standard sample materials.

Current Integrator. An electrochemical coulometer, which measures amounts of electricity with a precision of 2 parts in 100,000, was

developed to integrate variable currents and current pulses. The current

is passed through an electrolysis cell where it produces an equivalent

36
Fully automatic emission spectrometer with punehed-card read-out has ac- celerated homogeneity studies of new standard samples of metals and alloys

(page 36). amount of acid. Then a precisely measured constant current is passed

through the cell in the opposite direction and the time required to restore the solution to neutrality is determined. This amount of current, which is readily ascertained, is equivalent to the integral of the original current. Radioactive Sugars. The basis of organic chemistry is the understanding of the behavior of organic molecules. Because growth in this

field is best aided by systematic exploration of general principles and basic

reactions rather than by empirical experimentation, isotopically labeled

carbohydrates provide a powerful tool for probing the mysteries of

biological chemistry. Development of methods for synthesizing C

14 - labeled sugars and related compounds, sponsored by the Atomic Energy

Commission, was extended to tritium -labeled (H3 ) compounds. Procedures were developed for the rapid analysis of tritium compounds and

for the production of a variety of tritium -labeled carbohydrates.

Because branched -chain sugars have been found in antibiotics and a variety of natural products, new sources of these materials are in demand.

Certain sugar derivatives were discovered to undergo condensation

reactions and to form branched-chain sugars having twice the number

of carbon atoms as the parent sugar derivative. A branched-chain

10-carbon sugar derivative was obtained by condensation of 5-aldo-l,

2-isopropylidene-D-xylofuranose. The structure of this unique substance was determined, including the configuration at all asymmetric centers. Oil-Soluble Metal Standards. The detection of metals in lubricat- ing oils by spectrographic methods provides a simple means for judging

engine wear and serves as a guide for maintaining equipment in satis

37
factory operating condition. To provide standards for the spectroscopic

analysis of petroleum products, the Bureau is developing, under the

sponsorship of the American Petroleum Institute, a series of oil-soluble metal analytical standards. About 175 compounds were studied and

compounds were selected for use as standards for the determination of 23

elements.

Boron Compounds as Potential Fuels. Boron compounds are of

particular interest in the search for new high-energy fuels. Accordingly,

experimental and theoretical studies of the thermochemical properties

of these materials were made, with the support of the Navy Bureau of

Aeronautics. Mass-spectrometric methods were utilized to determine

the energies of the chemical bonds between boron and other atoms, and

molecular orbital methods were used to calculate ionization energies. In addition, a review of the vapor pressures and dissociation pressures of boron-containing compounds was completed.

Separation of Free Radicals. The possible use of free radicals as concentrated sources of energy is of current interest. Because these

substances are normally stable only at very low tempera tures, they must

be frozen and trapped to be studied. With the support of the Department

of Defense, an apparatus which seems promising for the controlled

sublimation of molecular species and separation at very low temperatures

and under a temperature gradient was designed. (For further information on free radicals, see page 29.)

Compact, portable equipment (insert), used to rapidly collect and analyze

small amounts of acetylene dispersed in air (as in smog). Arrow indicates

silica gel which adsorbs acetylene. (Other photo.) Flasks of reagent solutions

for treating collected air samples. The resultant color is compared with

known acetylene concentrations (tubes, center) (page 39).

I fr |
Instrument for Estimating Night Vision. At the request of the

Department of the Army, a device for testing night vision was developed.

The instrument utilizes crossed optical polarizers to observe crystals or strained transparent solids. By rotation of the polarizers, the brightness

of test objects seen against a dark background can be varied at will and

the limit of perception measured. Individuals who can perceive test objects only slightly darker than the background tend to have good

night discrimination.

Plasma Jet for Alloy Analysis. The "plasma jet," a new electrical source for exciting the spectra of materials, was developed for the Navy

Bureau of Aeronautics. The instrument gets its name from a flamelike

jet of ionized gases which appears above the cathode of a specially

designed arc. To obtain this gas flame, the solution under study is introduced into the arc which operates on a current of 20 amp, and the

vapor produced is carried by streaming helium gas from a constricted

channel through a ring-shaped cathode where the flame appears. The

very high temperature produced (about 8,000° C) completely volatilizes the solution, decomposes compounds, and excites atoms of all kinds,

including helium. This source, which has been applied to the analysis

of stainless steel, shows considerable promise for the determination of the

major constituents of complex alloys.

Other Chemistry Programs. Other projects studied this year

include investigation on the behavior of highly charged colloidal particles;

spectrometric identification of trace constituents in complicated gas mixtures (as in smog) for the Department of Health, Education, and

Welfare; and determination of the dielectric constant of heavy water

from 0° to 100° C. In addition, certification of the pH standards, for- merly available for the temperature range of 0° to 60° C, was extended

to 95° C to meet the requirements of pH control in many industrial

processes.

2.6. Mechanics

Basic to the Bureau's program in mechanics is the development, improvement, and maintenance of standards, and the development and

evaluation of techniques for the measurement of a large variety of mechanical quantities. These include volume capacity, weights and other

forces, static pressures, the flow of liquids and gases, vibration amplitudes,

and the speed, attenuation, and intensity level of sound. To provide

fixed points for comparison and to supplement these basic activities,

precise determinations are made of physical constants and properties of

materials, such as density, viscosity, and sound-transmission characteristics. In addition, fundamental research is performed in the mechanics

of solids and in fluid dynamics.

Acoustic Impedance of the Ear. Establishment of air-conduction

threshold standards for hearing requires a knowledge of the acoustic impedance presented by the human ear to an earphone. The problem of car
Absolute measurement of the threshold of hearing by bone conduction is expected to be of value in the diagnosis of the nature of certain hearing losses (page 40). impedance measurement hinges on the availability of a physical comparison standard. Although an obvious standard would be an air column,

continued measurements and analyses are showing that the behavior of an air column is not completely described by plane-wave theory. As an

observed increase in damping with length of column can be explained

largely by thermal losses to the column walls, the departures from plane- wave theory appear to be caused by end effects. Audiometry. To diagnose the nature of a hearing loss, an otologist

must know a patient's threshold of hearing by bone conduction, because

ability to hear sounds transmitted through the bones of the head is directly related to the sensitivity of the auditory nerve. Accuracy in diagnosis has been hampered by the lack of a standard for normal hearing

by bone conduction. Threshold of hearing by bone conduction was

therefore measured on an absolute basis for a group of otologically

healthy young adults. These results are being used to design a mechanical calibration system for bone -conduction receivers used in hearing

measurements.

Vibration Pickups. Recent developments in rocketry, jet propulsion, and high-speed turbines have increased the need for accurate vibration measurements at very high acceleration levels. To meet this need,

a method was developed for the Army to calibrate lightweight vibration

pickups at acceleration levels above 1,000 g over the frequency range

40
from 500 to above 10,000 cycles per second. By mounting a pickup on

one end of a thin aluminum rod, in which the frequencies of the longitudinal modes are much higher than the frequencies of the flexural modes,

and by driving the other end with barium titanate vibration exciters, it was found possible to separate the axial resonances from flexural and

shear resonances and to obtain good axial motion with large displacements.

Magnetic Tape Standards. Magnetic tape is used to record data

transmitted by guided missiles and satellites during tests, as well as to record data for input to automatic computers. As the usefulness of the

recorded information depends on the quality of the tape, standardized

tests for selection of magnetic tape are in demand. In studying this matter for the Air Force, it was found that the recording sensitivity of a magnetic tape can be determined from measurements of two magnetic

characteristics, the coating thickness, and the length of recording head

gap. Assistance is being given to other laboratories in setting up equipment for making these measurements.

Pressure Measurement. Attention was given to the improvement

of static and dynamic calibration techniques over the entire measurable

pressure range. Under sponsorship of the Air Force, a mercury U -tube

standard was designed for calibrating instruments at pressures encountered at high altitudes. In work on dynamic pressure calibrations, sponsored by the Department of Defense, an improved shock tube was

developed to provide step pressures up to 1,000 pounds per square inch,

and a dynamic calibration device was completed for Aberdeen Proving

Ground providing step pressures up to 50,000 pounds per square inch. Rapidly expanding activity in the area of very high pressures has

strongly emphasized the need for a pressure scale based on the physical

transformations of pure substances. An initial measurement was made

of the pressure at the I-ice-water triple point (about 30,000 psi).

Telemetering Transducers. In the flight testing of guided missiles and aircraft, and in the static testing of propulsion devices for these

vehicles, the "weakest link" in the instrumentation has often been the

transducer, which senses the pressure, acceleration, or other mechanical

quantity being measured. Under the sponsorship of three Department of

Defense agencies, the Bureau is carrying on a long-term program aimed

at providing additional information on the performance of transducers.

The program resulted in the development of testing techniques for transducers and in numerous reports on performance tests of typical

transducers used in missile and aircraft testing.

Promotion of Flow by Mixing. Drag is experienced when ships

and aircraft move through fluids, such as water and air. Since nature

provides turbulent motions which mix the impeded fluids into the outer stream, fluids are kept moving by shaping the body to make the pressure gradient sufficiently small. However, the pressure gradient, or bod)

shape, would require less rigid control if higher rates of mixing than are provided by natural turbulence were obtainable. Under the sponsorship

41
To improve telemetering transducers and their application to the flight

testing of missiles and aircraft, an intensive study of transducer performance

characteristics is being conducted. Photo shows a shock tube used to make

pressure-sensitivity studies (page 41). of the Office of Naval Research, the Bureau investigated the mixing

problem, exposing the fundamental mechanics of mixing and shedding more light on the relationship between rate of mixing and pressure

gradient.

Friction Between Density Currents. Many practically important

phenomena involve the movement of superimposed fluids of different

densities. These include salt water intrusion into the mouths of rivers and the flow of silt laden water into estuaries or into fresh water reservoirs. In such cases, the movement of the separate fluids depends in part upon

the frictional drag between them. The friction at the boundary of a fluid

is known only if the flow is laminar, that is, smooth and orderly. However, since one or both of the fluids are often turbulent, an investigation was conducted to determine experimentally the drag which a turbulent

fluid exerts upon another fluid. The dependence of friction upon velocity

and density in the thin boundary between fresh water and flowing salt water was determined by directly measuring velocity and density variation

through the boundary.

High Strength Aeronautical Fasteners. The restrictions on working space, the requirements of flush construction, and the high loads on modern aircraft have created a need for special fasteners for use in loca- tions which permit access to the head of the fastener only. Under

sponsorship of the Navy Bureau of Aeronautics, studies of flat head

fasteners provided data and mechanical test methods for fastener

specifications.

42
Creep of Structural Beams. The high speeds which are attained

by modern aircraft cause aerodynamic heating in certain critical parts

of the structure. Sustained flight under these conditions, which will be

possible with atomic -powered craft, may lead to serious creep deformation.

Under the sponsorship of the National Advisory Committee for Aeronautics, a program was undertaken to develop design methods for esti- mating the creep deflections of wing beams subjected to bending.

Suitable methods of analyzing the creep deflections of structural beams

were developed around an "elastic followup" technique. Methods of

estimating creep deflections which were derived are applicable to a wide

variety of built-up beams. Good agreement was obtained between

calculated values and the results of creep tests conducted on riveted and

extruded I-beams in pure bending and in bending with transverse shear. The analyses are now being applied to tapered multiweb box beams.

Wind-Induced Vibration of Wires. In the rural areas of the United

States, wind-induced vibration of telephone and distribution wires damages the wires and increases maintenance costs. The Rural Electrification Administration is sponsoring a test program to study the problem of wind-induced vibrations in an effort to improve the construction of elec- trical systems and thereby reduce the maintenance costs. Part of this program was to determine the Strouhal number, a dimensionless constant which relates the velocity of the wind and diameter of the wire to the

frequency of the forced vibration of the wire. The Strouhal number was

measured in a wind tunnel for several circular wires and wires of irregular cross section, leading to a useful approximate formula for the frequency

of wind-induced vibration in such wires. Thermal Stresses in Aircraft Parts. An investigation, sponsored

by the Office of Naval Research, provided information on the thermal

stresses introduced in aircraft parts by exposure to thermal radiation.

I it

Experimental setup (left) for studying natural wind vibration

of telephone wires, which causes

a majority of the line failures in the country's wind belt. Right: Instruments for making windvelocity measurements in windtunnel tests of the same phenomena (page 43). 489867—59—4 43
Radiation can be an important mode of heat transfer when the temperature of the structure reaches about 1,000° F. The emissivity of the in- terior surfaces of box beams was varied to determine its effect on temperature distribution, maximum thermal stress, and beam deflection. It was found that, for various beam geometries and heating conditions,

increasing the interior surface emissivity of a box beam to blackbody

emissivity considerably reduces the temperature gradient at temperatures above 700° to 900° F and the maximum thermal stress and deflection at temperatures above 900° to 1,200° F. International Density Comparisons. At the invitation of the

International Bureau of Weights and Measures, the Bureau took part in an international comparison of density determinations. As part of this comparison, a special cylinder of stainless steel is being circulated among

the national standardizing laboratories for an independent density de- termination of high precision at each laboratory. The average density

value obtained at the Bureau agrees with the average of values reported

by others within less than 2 parts per million. Measurement of Jet Engine Temperatures. A continuing pro- gram directed toward the improvement of devices for measuring jet engine

temperatures is sponsored by the Wright Air Development Center. Because engine temperatures and engine and aircraft speeds are constantly

increasing, additional emphasis is placed upon the accuracy of sensor response to sudden changes in the engine. Also, mechanical conditions

are more severe in the faster streams of hot exhaust gas in the engines.

Thus, improved durability and faster response, two conditions that are inherently incompatible for immersion devices, are desirable. Several

resistance -type temperature -sensing elements were examined, and a system for parallel operation of these elements in an engine was analyzed.

This system, as are similar systems for use with thermocouples, is designed

to permit operation of the temperature measuring and control systems

when one or more of the measuring sensors connected in parallel drops out of the circuit because of mechanical failure. The variation of response with temperature of a thermocouple junction

to a sudden change in temperature of the gas in which it is immersed has,

until recently, been largely ignored. Because of the increasing requirements for higher accuracy, interest in this variation recently has become

greater, and a cooperative program between three industrial laboratories

and the Bureau to investigate this phenomenon was undertaken at the

request of the Committee on Temperature Measuring Devices of the

Society of Automotive Engineers.

2.7. Organic and Fibrous Materials

The Bureau undertakes a wide range of basic and applied research on

natural and synthetic polymeric materials, including rubber, textiles, paper, leather, and plastics. All of these materials are composed of long,

chainlike molecules formed by polymerization. Many of their useful 44
properties depend upon the size, shape, distribution, and flexibility of their molecules and interaction with other molecules. To advance fundamental knowledge of these industrially important materials and thus to aid in their efficient utilization, the Bureau investigates the mechanisms

involved in forming polymers, their constitution, structure, and properties. Studies are also made of the applications of polymeric materials to dental technology.

During the year basic research included investigations of thermal degradation of collagen and plastics, and of the structure and mechanisms

of dimensional changes in crystalline fibers. The adsorption of polymers on glass fibers was studied, as well as the molecular constants of polymers.

New methods were developed for impact testing leather, and for making

torque -speed measurements on high-speed dental drills. Research on

properties of materials dealt with problems such as the dimensional sta- bility of map papers, and the radiation resistance of plastic packaging

films, and high -temperature resistant fluorine polymers.

Stress-strain Relation for Rubber. The stress-strain relation of a typical pure -gum rubber vulcanizate after a given period of creep can be

represented by an empirical equation developed several years ago at the

Bureau on the basis of observations of specimens in tension. An examination and analysis of published data on pure-gum vulcanizates showed

that the same equation with the same constants also represents data obtained in the compression region with compressions as large as 50 percent,

where the relative length is 0.5. Analysis of Textiles. The expanding array of new and improved

textiles accents the need for adequate analytical methods to identify

these products. A rapid and convenient technique was developed for identifying the components of very small specimens of finished and coated

textiles, and it is also applicable to related materials such as coated papers,

adhesives, and plastics. The specimen is fractionated by a series of ex- tractions and the substances present in the fractions are identified from

their infrared spectra.

Reference spectra collected for the work include spectra for textile

fibers, finishes, coatings, and related materials. This information is

7 7 J5 > automatically recorded on punched cards which permit the mechanical

identification of unknown materials from their spectra.

Impact Phenomena in Fibers. The capacity of fibrous materials to withstand high impact stresses and to absorb large amounts of impact

energy without rupturing has made them increasingly important to modern industry and national defense. In the Bureau's continuing in- vestigation of the phenomena of strain propagation i l impacted fibrous materials, theories leading to analytical expressions for describing the phenomena of strain propagation, reflections, interactions, and attenuation in textile filaments were developed. These phenomena were observed experimentally and evaluated quantitatively with NBS impac t testing equipment.

15
Through the cooperation of the Army Chemical Center, other tests at much higher impact speeds were made for analysis at NBS. Experimental

techniques and intricate electronic and microflash equipment developed

by the Center were used. The results of these tests not only have practical applications in the design and development of safety lines, seat belts,

parachute shroud lines and webbings, cords for tires, and flexible body

armor, but they also provide basis information relating to the structure of fibers and the development of fibers and yarns of superior impact

properties.

Improved Map Paper. Good dimensional stability is needed in the

paper used for multicolored military maps. When such maps are printed

by offset lithography, a change in the paper's dimensions, resulting from

changes in moisture content between successive impressions with different

colors, can cause serious misregistration. Research conducted for the

Army Engineer Research and Development laboratories showed that a laminate prepared by bonding two sheets of 2 -mil thick map paper to the

two sides of a film of polyethylene terephthalate has much lower moistuie

expansivity, with improved sti ength properties. Compared with regular

military map paper, hygroscopic expansivity was 30 percent less in the

machine direction of the laminated paper, and 45 to 70 percent less in the cross direction. Folding endurance was many times greater than

that of the regular map paper, while tensile, tearing, and bursting strengths were also increased.

Preservation of Archival Documents. The lamination of archival

documents with cellulose acetate film has been practiced for more than

20 years in order to strengthen weak or damaged papers and to protect

them against injury from handling. However, as this film was not

originally designed for archival purposes, a study was undertaken to develop specifications for cellulose acetate with maximum stability.

Sponsors of the program were the Library of Congress, the Army Map

Service, the National Archives, and the Virginia State Library.

A laboratory formulation was developed for document laminating

film which should be far more durable than the materials previously

employed, and specifications have been suggested for use by archival

agencies in its procurement. Related studies confirmed and denned the

advantages of using tissue paper to reinforce the laminated document,

and of neutralizing the acid in documents before lamination to prevent

acid deterioration which occurs as the film ages. Impregnation of Leather. The wear of sole leather was improved

50 percent by impregnation with a blend of elastomers and resins, in a continuing program sponsored by the Navy Bureau of Supplies and

Accounts. The treatment is easily applied by immersing tanned, unfilled,

unfinished leather in a petroleum solution of polymer blends. The

blends consist of an elastomer such as butyl rubber, polybutene, or poiyisobutylene, and a resin. The resin is added to maintain the inherent

stiffness of the leather and dimensional stability of the soles during wear. 46
Equipment (left) for testing the strength of leather, its stretch, and tendency

to crack. Specimen is being removed from the assembly that clamps it be- tween two plungers, which strike alternately from either side (page 47). At right is apparatus used for extracting and evaluating leather impregnants

in efforts to increase the wear of sole leather (page 47).

To insure adequate penetration of the leather matrix, elastomers with a molecular weight under 10,000 should be used.

The improvement in wear was determined in actual service tests with

impregnated vegetable -tanned and chrome -retanned soles. The chrome - rctanned leather gives longer wear than the vegetable-tanned leather and is a better base material for impregnation. This process is now commercially employed, particularly in the production of boys' shoes. Impact Test for Leather. In an impact test to evaluate shoe upper

leather, a newly-developed machine was used to deliver repeated thrusts

to both sides of a specimen until failure occurs. The number of impacts

required to produce cracking of the grain and puncture of the leather increases with increase in diameter of the plunger. The load per unit

thickness of leather is inversely related to the number of impacts required

to produce failure. Examination of the data obtained with the impact

tester indicates that resistance to grain cracking, elongation, and puncture can be satisfactorily evaluated.

Straight chrome-tanned leather containing stuffing grease showed higher

resistance to puncture than similarly tanned leather containing fat liquor.

When both leathers are degreased, their strengths are practically equal.

This would suggest that the impact test can also be used to evaluate

lubricants in shoe leather. Straight chrome-tanned leather showed

much greater resistance to repeated impacting than cither chrome

syntan-retanned or chrome vegetable-retanned leather. The results obtained for various tannages and for accelerated aging were found to be

similar to those obtained in other tests. 47
High- Temperature Fluorine Polymers. Since most plastic and

rubberlike materials fail rapidly at temperatures of several hundred

degrees, their use in many types of equipment is restricted. However, some experimental totally -fluorinated aromatic polymers give an indication of better resistance to high temperatures than any organic polymeric

material previously known.

A joint program sponsored by the Office of Naval Research, the Navy

Bureau of Aeronautics, and the Bureau is underway to discover as many

techniques as possible for converting perffuoroaromatic raw materials

such as hexafluorobenzene to useful monomers and polymers. New

materials that have already been synthesized include pentafluorophenol,

pentafluorophenyl polymer, and pentafluorostyrene. Simple ways were

also found to prepare, with hexafluorobeazene as a starting material, some crucial intermediates previously known only in small quantities.

The preparation of polymers having improved high -temperature properties may now be feasible. Molecular Constants of Polymeric Materials. As part of a pro- gram to improve the methods of determining molecular weights, an

absolute photometer was designed and built to measure precisely the

light scattered by solutions of polymers. With data from this instrument,

the molecular weight and radius as well as characteristic thermodynamic

quantities can be determined more reliably than by any method pre- viously reported. Some results show important, previously unknown

details of the thermodynamics of solutions under so-called ideal solution

conditions. However, with narrow fractions of polystyrene, there is a discrepancy of ± 6 percent between the molecular weights determined by

the photometer and by another absolute instrument, the equilibrium

ultracentrifuge. Further work is in progress to resolve this discrepancy.

Dimensional Changes in Fibrous Macromolecules. In a fundamental investigation of the physicochemical basis of dimensional changes

that occur in systems of fibrous macromolecules, two general types of

mechanisms have so far been elucidated. The melting of a highly oriented

polymer is almost invariably accompanied by a marked axial contraction

and conversely, the crystallization of an oriented polymer results in an

increased length. This process, as usually observed, is irreversible unless an equilibrium stress is maintained.

More recently, a second mechanism for developing changes in length was discovered. A highly oriented polymer, cross linked by gamma

irradiation, increases in length in the amorphous state on subsequent

relaxation. This increase depends on the original orientation and the

number of cross linkages introduced. In the case of cross-linked fibrous

polyethylene, a 25 percent increase in length in the amorphous state was observed.

When polyethylene fibers cross linked in the prescribed manner are allowed to crystallize from the melt, an increased length manifests itself in the development of a preferential axis for crystallization. Thus an

4S
equilibrium state of oriented crystallization is obtained. On subsequent

melting the fiber shrinks about 25 percent and spontaneously reelongates on cooling. This process continues in a cyclic manner without the application of any external force and is a means of converting thermal energy

into mechanical work.

These principles should be applicable to crystalline polymers containing reactive functional groups. Also, a system is envisioned that will be

capable of converting chemical energy into mechanical work by utilizing an appropriately cross-linked crystalline polymer as the working substance. Polymer-Glass Adsorption Studies. The adsorption of polyesters

from dilute solutions onto glass, silica, and alumina surfaces was investi- gated. This work is part of a program on the mechanism of reinforce- ment in glass fiber laminates, jointly sponsored by the Navy Bureau of

Aeronautics and the Bureau. The quantity of polymer adsorbed is considerably greater than could be accounted for by a monolayer of

polymer molecules lying flat on the surface of the solid; the polymer

appears to be deposited in sequences separated by bridges. Polyester

adsorption onto glass is irreversible and the temperature dependence is either very small or zero. A large number of sites are available on the

solid for bond formation and relatively strong glass-polymer bonds are formed.

Radiation Stability of Plastic Packaging Materials. Plastic

films have a potential market as packaging materials for foods which are

to be preserved by radiation sterilization and pasteurization. Under

the sponsorship of the Army Quartermaster General, an evaluation is being made of the effect of high-energy radiation on various plastic films that may be suitable. Some plastic films, such as polystyrene and

polycarbonates, exhibit satisfactory stability when exposed to a highenergy radiation dosage comparable to that required for food preservation.

Stability of Polyvinyl Chloride Plastics. The stability of polyvinyl chloride and its copolymers has been a major problem to the plastics

industry because of the polymers' sensitivity to heat, sunlight, and

traces of metals. An investigation of the mechanism of degradation of

polyvinyl chloride was therefore initiated to provide a basis for the selec- tion of stabilizers on a rational rather than an empirical basis. When

polyvinyl chloride was exposed to heat and ultraviolet radiant energy, the gaseous products evolved included hydrogen chloride, water, and

benzene. Changes in the chemical structure of the polymer were studied

by infrared spectrophotometry. The mechanism of decomposition was

found to be a free radical chain reaction with an activation energ) of approximately 30 kcal. This study should thus make possible the

selection of stabilizers on a rational basis. Mechanism of Rain Erosion. One problem that has accompanied

increase in airplane flight velocities is rain erosion of the radar housing

and of the leading surfaces of an airplane. However, a blunl object

Li)
flying at supersonic velocity through air is preceded by a detached shock wave, and a waterdrop should be essentially atomized under the conditions

that exist in the zone behind this shock wave. An investigation was made

for the Wright Air Development Center to determine whether, within

certain limits of random shape and size, and of waterdrop size, this atomization would have time to occur. The results indicate that if the

flying object is a sphere having a diameter of 4 feet and if it is moving

with a Mach number in the range of 1.3 to 1.7, waterdrops having diameters up to 1.4 mm that enter the zone of detachment will be completely

reduced to mist before they impinge on the surface of the sphere.

Vapor Phase Analysis of Polymers by Chromatography. Identification and quantitative determination of the copolymeric constituents of

methyl methacrylate polymers cannot be readily accomplished by ex- tractive procedures. The presence of cross-linking agents causes the

resulting polymers to be very insoluble in most solvents. So chromatography was used at the Bureau to obtain these data. First the polymer was pvrolyzed at 340° C, and then the vapor phase of the liquid pyrolysate was analyzed by means of a chromatographic column. The presence of

0.2 to 1.0 percent of various comonomers could be detected easily and

rapidly. Quantitative estimation of copolymeric components such as methyl acrylate and ethylene dimethacrylate with a precision of ± 1 percent was accomplished by this method.

Low-Angle Diffraction Studies. A special X-ray diffraction camera

which can detect periodic spacings of 1000 A (0.1 micron) was used to study the long range periodicity on fibrous polyethylene and in collagen.

Polyethylene fibers were shown to contain periods as wide as 480 A; the

collagen period was found to be 640 A. Various treatments of polyethylene fibers altered the observed periodic spacing. The results of

this work may provide a clue as to the nature of the bond between

inorganic salts and long chain polymeric materials.

Speed-Torque Measurements of High Speed Dental Instruments. One of the most significant recent developments in dentistry

has been the introduction of handpieces that operate at very high rotational speeds. These instruments have won immediate acceptance from

both dentists and patients because of higher cutting efficiency and less annoving vibrations to the patients. The speeds, in some cases as high

as 250,000 rpm, have been attained, however, only by sacrificing a high

proportion of the torque available with the older handpieces. So a total reevaluation of dental cutting techniques and mechanisms has become

necessary. An essential part of such an evaluation must be a method

for studying the torque-speed characteristics of the handpieces themselves. In cooperation with the Air Force, Army, Navy, and Veterans Administration dental services, an apparatus for this purpose was developed that

will simultaneously measure speeds up to 300,000 rpm and torques to 30 g cm. In place of the dental bur, the apparatus employs a per- manent-magnet cylinder which is braked by means of a synchronous

50
Equipment designed to make speed-torque measurements of high-speed

dental handpieces. The rapidly growing use of such handpieces has necessi- tated a total re-evaluation of dental cutting techniques and mechanisms

(page 50). external magnetic field. The braking torque is measured as the torsion

of a calibrated wire suspension, and the rotational speed is determined

from the frequency of the field. The equipment is being used for the

evaluation of handpiece designs and to provide background information

for studying the cutting mechanism of dental burs. Denture Reliners. Materials for relining dentures have been

available to the dental profession for a number of years and have gained

considerable clinical acceptance. A Bureau study of the physical properties of these materials was jointly sponsored by the American Dental

Association and the Federal dental services. The materials harden with

considerable rise in temperature, and when cured under clinical conditions

porous resins are obtained. Because of high plasticizer content, the

hardness, indentation and recovery values, and the water solubility are poorer than those for self-curing denture resins. Color stability of the

reliners is often unsatisfactory and some relined dentures are very sticky

when removed from the mouth. However, flow and detail of the relined

denture are adequate, and clinical studies give no significant indication

of warpage or dimensional change.

2.8. Metallurgy

Metallurgical research is directed toward a better understanding of the properties of existing metals in order that new or improved metals

and alloys may be developed to meet new applications or to give better

performance. Studies are made of the effects of treatment, fabrication,

and conditions of service on the structure, behavior, and properties of metals and alloys, with considerable emphasis on metals subjected to high temperatures. Information derived from these studies is used to improve the design and operation of jet-propelled aircraft, missiles, and

other airborne equipment.

51
Constitutional Diagrams for Metals. To understand and predict

the behavior and utilization of alloys, it is advantageous to have detailed

constitutional diagrams that show melting ranges, structural changes

occuring at various temperatures, intermetallic compounds, and solubil- ity-temperature relationships. A study was initiated to establish an

accurate constitutional diagram for Type 431 stainless steel (16 percent

chromium-2 percent nickel). This metal normally can be heat-treated

for a combination of high hardness and toughness that makes it greatly

desirable for use in the aircraft industry. However, its utility is somewhat

restricted because its ductility appears to be highly individualistic from

heat to heat, and occasionally a heat of low ductility is produced. The

variables of manufacture, chemical composition, and heat treatments,

that may cause the change in toughness are not understood, but the

constitutional diagram is expected to provide clarifying information.

Commercially Important Alloys. Alloys whose basic compositions

include chromium, iron, molybdenum, and nickel are commercially important for use at elevated temperatures. To have a basis for selecting or designing alloys that will retain their strength under prolonged heating,

it is necessary to know what solid-state reactions occur. This information

is supplied by current investigations in which the composition limits of

the reacting phases at the various temperatures are summarized in constitutional diagrams. Examination of several hundred alloys that were heat-treated in the range of 800° to 1,300° C resulted in identifying

several phases that had not previously been reported and in determining

the temperature and compositional limits of many of the phases in the

chromium - nickel, chromium -molybdenum - nickel, nickel - molybdenum,

and iron-molybdenum-nickel systems.

Uranium Alloy Studies. A study of the binary alloys of uranium

with the six platinum metals, sponsored by the Atomic Energy Commission, was undertaken to obtain data on compound formation, reaction

temperature, and relative solubilities of uranium with these metals.

Small additions of the individual platinum metals to uranium produce

alloys of lower melting temperatures than uranium itself, but further

additions produce intermetallic compounds that may have useful properties. In many cases, the melting points of the compounds are higher

than either of the elements from which they are formed. For example,

in the uranium-rhodium system, the melting point of a 75 atomic percent

rhodium compound is about 2,200° C compared with the melting point

of rhodium at 1,966° C. The practical importance of these alloys may be

in the development of atomic power, but other uses are being considered

because of the relatively high temperatures at which certain of these

compounds decompose.

High- Temperature Metals. Steels capable of being fabricated into

sheet that retains a high strength-to-weight ratio at temperatures up to 1,000° F are urgently needed for modern aircraft. Investigation of steels capable of structural application in aircraft at tensile strength levels

52
over 200,000 psi, while at temperatures of 800° to 1,000° F, was conducted

for the Navy Bureau of Aeronautics. Thus far, the properties of hotwork die steels of the 5 percent chromium type appear promising in meeting some of these requirements. Accordingly, commercial steels from

various manufacturers were procured for an evaluation hy tensile and

stress rupture tests. A study to determine the effects of various heat treatments on the

mechanical properties of 17 to 7 PH (17-percent chromium, 7-percent

nickel, precipitation hardening) stainless steels was continued for Wright

Air Development Center. The conditions for heat treating this steel to obtain high strengths in tension at temperatures up to 1,000° F were

established. Under appropriate heat treatments, 17 to 7 PH steel de- velops high strengths at room temperature with sufficient ductility to be

suitable for use in aircraft components. However, some data indicate

that the steel becomes excessively brittle when exposed for long periods

at temperatures of 600° to 800° F. Apparently the change in ductility

is affected by time, temperature, and stress. Tests are being conducted

to determine whether this is a real phenomenon. If it is, treatments will be attempted to eliminate or ameliorate the effect. The 17 to 7 PH steels also contain about 1.25 percent of aluminum and

small amounts of carbon and nitrogen. How these elements affect the

precipitation hardening reaction, the mechanism of the reaction, and the

composition of the hardening compound are not definitely known. Metal- lographic and X-ray examination directed towards the identification of

the compound, and tests to evaluate the influence of nitrogen on the

mechanical properties of the steel are in progress.

Multicolored pattern (left) formed when a copper single-crystal sphere is corroded in air-saturated distilled water at room temperature. The studj

of systems involving single crystals is providing a better understanding of t lu» fundamental processes of corrosion. At right is the apparatus used to groM

single metal crystals from their vapor (page 55). 53
The influence of stress, strain rate, temperature, and prior strain history, on the mechanism of creep, flow, and fracture characteristics of highpurity nickel, copper, and two nickel-copper alloys was investigated.

It was found that the resistance to creep was materially increased by

alloying the component metals. Although experimental results con- formed to both the theory of exhaustion and of generation of lattice defects (over limited ranges of temperatures and stresses) during the first stage

of creep, none of the existing equations is entirely suited for defining the

extension -time relation in each of the three stages of creep. Under the sponsorship of the Navy Bureau of Aeronautics, a study was

initiated of the thermoelastic properties of several metals and alloys to determine modulus-temperature relationship. This study, covering a somewhat broader temperature range than usual, is being made to add to basic information on the properties of metals and alloys, as well as to

assist in selecting materials suitable for the fuel metering springs used in modern aircraft engines. These springs are subjected to high and rapidly

changing temperatures.

During the year work was undertaken on the design and construction

of a soft X-ray spectrometer for obtaining the distribution of occupied

electronic levels in metals and alloys in the solid state. As the complete

equipment cannot be purchased, it is being built and assembled at the

Bureau. Spectrographic data for the solid state by soft X-ray techniques

are expected to contribute to a fundamental understanding of alloying,

and of the relationship between physical properties and electronic structure. This should lead to the design of special-use alloys, particularly

those for high temperature application.

Titanium. An evaluation was made of the effects of variations in

stress systems and temperatures on the tensile properties of commercially

pure titanium and a titanium alloy containing 4 percent of aluminum and

4 percent of manganese. The study showed that the tensile strength

and fracture stress increased and the ductility decreased with either a decrease in temperature over the range of -f 100° to — 196° C or an increase

in notch sharpness. The very low ductility obtained with the notched

specimens at — 196° C was attributed primarily to stress concentrations

at the root of the notches. Prestraining unnotched and notched speci- mens of both materials in tension at +25° C decreased the retained ductility in subsequent tension at 100° or — 196° C. Plastic Deformation. Many factors influencing the properties of

metals are related to the crystal lattice which can be studied by X-ray

diffraction techniques. In the mechanical metallurgy laboratory, work

was directed toward obtaining information by these techniques on lattice imperfections and how they are affected by plastic deformation. The

results will be of practical as well as theoretical value. Gage Block Materials Evalua ted. A study of material suitable for use in the production of ultraprecise gage blocks was continued. Optimum conditions were established for heat treating and stabilizing several 54
steels commonly used both for gage blocks and for nitriding types 410

and 302 stainless steels and Nitralloy. Other procedures for producing

hard surfaces on gage blocks such as flame and chromium plating, thermospray, chromizing, carbonitriding, and carburizing are being evaluated.

Additional material selected and procured for use in the program include

alumina, titanium carbide precipitation-hardening stainless, and highspeed tool steel. About 350 gage blocks, % in. X 1% in. X 2 in., were proc- essed and are under observation for dimensional stability (see page 20).

The results obtained in nitriding 410 stainless steel appear exeedinglv

promising, not only because the gaging surfaces of the blocks are verv hard but the blocks themselves can be finished to a high degree of flatness and parallelism. This steel has approximately the same coefficient of

expansion as most of the structural steels. Corrosion. For several years the Corrosion Research Council has

partially supparted a program of research in basic corrosion processes. In one phase of the work, a study was made of the formation of oxide

films on metals in water. It was found that the rate of build-up and

composition depended on whether the films were formed in stagnant

pure water or in water stirred by bubbling oxygen. The rate of formation was also found to depend on both the crystallographic plane upon which

the film was growing and on the oxygen concentration in the water. Studies of the interactions of free radicals with metallic surfaces at low

temperatures were conducted. A reaction takes place at temperatures

as low as 4° K when single crystals of copper are exposed to atomic

oxygen, but not when exposed to molecular oxygen. This work is part

of the free radicals research program supported by the Department of

Defense (see p. 26). In another program partially sponsored by the Corrosion Research

Council, the stress corrosion cracking of a magnesium alloy was found to depend not only on the stress applied but also on the strain rate. If the

average strain rate exceeds a critical value, the alloy cracks within a few

minutes. But if this rate is not exceeded, cracking does not occur during an experiment extending over a 20-hour period.

Experiments on the stress corrosion cracking of stainless steels indi- cated that the application of anodic currents as small as 0.03 ma/cm2 can greatly accelerate cracking, but that cracking can be prevented by

applying a cathodic current density of 0.04 ma/cm2

. A method was

developed for growing single crystals of aluminum and copper ol an)

desired cross-sectional shape and axial orientation within I deg. This

makes possible the study of the effects of crystal orientation upon metal

corrosion and also possibly on other properties of metals.

A study of copper electrodeposited on single crystals of copper re\ ealed that the epitaxial relationships depend on the crystal orientation oi the basis metal. On certain crystallographic planes the deposit buill up as a continuation of the base structure; on others, as both a continuation and

a twinned structure. This study provides informal ion on the bonding

55
Transparent tape applied to the surface of a metal specimen in which a minute fatigue crack has been induced demonstrates a new effect. As con- tinued cyclic stress is applied, gas evolves in increasing amounts under the

tape. The origin of the gas is now being investigated in an effort to shed new light on the processes of metal failure (page 57). forces of the crystal and should lead to a better understanding of its deterioration during the corrosion process. Growth of Metal Crystals From Their Vapor. Experiments were performed to find a method for obtaining quantitative data on the growth

rate of metal crystals from their vapor. A number of optical techniques were considered and set aside in favor of a thermoelectric method for determining growth rates. Although not yet completely proved, the

method appears to be promising. If successful, it will yield data of

hitherto unattainable precision and accuracy. It will also allow a critical evaluation of a previous theory of crystal growth which, although generally

accepted, has not yet been experimentally proved.

Gases in Metals. Eight steels of the carbon and low-alloy types were certified and made available as standard samples for gases in metals. In addition, a new vacuum-fusion gas analysis unit of modern design was

constructe 1. This unit, currently in operation in studies of techniques

for the determination of gases in titanium, will be used in studies of a number of other metals.

56
Metal Fatigue Cracks. In a metal fatigue test, transparent tape was applied to the surface of an aluminum alloy specimen in which a minute fatigue crack had been induced by several thousand cycles of

stress. When the specimen was then stressed for an additional 1,000

cycles, small bubbles formed under the tape. A series of investigations

disclosed that bubbles formed as soon as detectable cracks were present.

Even when the cracks were so small they could be seen only with a microscope under special lighting, the bubbles were large enough to be readily seen with the unaided eye. However, in additional experiments it was

found that the bubbles could not be produced with some metals. 1

therefore appears that the phenomenon may be due to surface reactions,

but further studies must be made before the mechanism of the effect can

be fully explained.

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, and behavior of these materials as an aid to mineral industries

in the production of glasses, refractories, porcelains, pottery, enamels,

cermets, and cements. Much of the research during the past year, however, related to the high-temperature properties of these materials.

This is due to the increasing need of fundamental knowledge to further

research in aeronautical fields such as high-speed flight, and in power

sources utilizing new high-energy fuels or atomic energy. Ferroelectric Materials. Ferroelectric oxides, of which barium

titanate may be considered the prototype, have found wide applications

as accelerometers, as dielectrics in capacitors, as memory devices for electronic computers, and as transducers in ultrasonic generators. Because there are still many problems in the application of these materials,

the Bureau conducted a basic investigation on the relationship between

the fundamental structure and the ferroelectric properties of BaTi03

. Ferroelectric crystals are generally subdivided into minute regions

called domains. Although each domain is uniformly polarized along one

crystal axis, the direction of this axis varies from one domain to the next. However, some of the most important applications of ferroelectric materials require that the domain axes be more or less alined along one preferred

direction in the specimen. This has been accomplished by two procedures. In both, a d-c field controls the orientation—the stronger the

field, the more efficient the alinement process. Thus, it is necessary to know the maximum, or "breakdown," field that the material can stand. Since previous measurements indicated only that the breakdown Geld generally decreased with increasing temperature, detailed measurements

were made during the past year on ceramic BaTi03 over a wide temperature range to gather more information. These data showed not onl\ the general negative temperature coefficient, but also well-defined minima at 57
Specimen holder and electric furnace used in determining the liquidus temperature and rate of crystal growth in glasses. Liquidus and crystal growth

data provide a hasis for structural interpretation. Right: Micrograph of

crystals in glass (page 61). the ferroelectric transitions at —90°, 0°, and 120° C. Having minima

at these points is important for two reasons. First, the depth of the

minimum at 0° C shows that the efficiency of the domain alinement process at this temperature cannot be as high as expected on the basis of the

older breakdown data. And second, the very existence of the minima

indicates that the previously accepted mechanism of simple thermal

breakdown is not completely correct and must be modified.

Low- Temperature X-ray Crystallography. To obtain previously

unrecorded X-ray diffraction patterns of many low temperature phases,

equipment was designed for rapid electronic recordings of data from polycrystalline specimens at temperatures down to 4 deg above absolute zero. In this project, sponsored by the Department of the Army, some new

phases were discovered (such as a low-temperature form of ammonia),

and basic information was added on the structures of solid ozone, nitrogen,

and ammonia.

With the low temperature apparatus, samples can be frozen directly

from a vapor whose flow rate can be controlled. In this way, lowtemperature glasses—that is, any solid lacking long-range order—were made of water, hydrogen peroxide, ammonia, ammonium azide, hydrazoic acid, and oxygen. However, even those vapors that tend to be

frozen into crystalline solids show crystal imperfections. This can be overcome by annealing the solids to form more perfect crystal aggregates.

Phase Equilibrium Studies. Phase equilibrium studies—which are important in the understanding of various ceramic and metallurgical

processes, such as glass formation, and electronic -component fabrication

are concerned with the variables of temperature, pressure, and over-all composition governing the composition of the individual coexisting phases.

Because germania (Ge02 ) is similar to silica (Si02 ) in that it is a glass

58
former and has the same cation-oxygen ratio and tetrahedral-oxygen co- ordination, comparison studies of MgO-Ge02 and MgO-Si02 were made.

Marked parallelism was noted between the systems in immiscibility,

polymorphism, and compound formation. However, a new compound,

4MgOGe02 , which is not observed in the silicate system, was found.

This compound is of interest in the formation of commercial phosphors,

which are used for such diverse applications as luminous paints, highspeed X-ray films, radar screens, and television tubes. Phase diagram investigations are also being conducted on the BaOB2 3 -Si02 system. Within a large compositional range in this system it was observed that two liquids are formed at complete melting, although

the usual one-liquid region is found at sufficiently high temperatures. In relation to this, the shape of the two-liquid : one -liquid boundary was

determined.

Ceramic Dielectrics. Ceramic systems are assuming an ever in- creasing importance as essential components of electronic circuits because

of their ruggedness, compactness, and temperature stability. Investigating new ceramic compositions in rarer oxide systems, the Bureau found

that some compositions of the four-component system, lead oxide-niobium

pentoxide, zirconium dioxide -titanium dioxide (PbO-Nb2 5 , Zr02 -Ti02 ) have promising piezoelectric properties. Studies on PbO-Nb2 5 were

completed, showing that the desirable high -temperature ferroelectric polymorph of PbNb2 6 can be stabilized by small additions of Zr02 or Ti02 . To study further the crystallography of high -temperature trans- formations, a systematic X-ray study was made of compounds in the

beryllium oxide- and strontium oxide -niobium pentoxide (BeO- and SrONb2 5) systems, as well as in the corresponding tantalum oxide (Ta2 5 ) systems. In the calcium oxide -titanium dioxide (CaO-Ti02) system (another

dielectric system of interest) a new compound of the composition 4CaO3Ti02 was discovered, which led to revision of the existing phase diagram.

New Data on Silicates and Related Compounds. An understanding of the nature of the forces between atoms and molecules in compounds

is necessary for efficient utilization and modification of existing materials

in specific technological applications. One method of investigating these

forces is by studying the bond properties by infrared analysis. A pressure

cell made from a type II diamond, which is characterized by a low absorption spectra band in the 8 to 10 micron region, was completed for obtaining infrared data on solids subjected to high pressures and elevated

temperatures. With the infrared spectrometer, data were obtained on

silica and germania oxides, both of which exist in several polymorphic

forms. The study showed that a new dense form of silica (coesite) was

built up of the same silicon-oxygen tetrahedra found in other forms of

silica, except that the tetrahedra are more closely packed. Similar studies on a series of garnets and hydrogarnets yielded new information on the

relation of the hydrogen in hydrogarnets.

48,98,67—59 5

51)
Crystal Structure of Inorganic Materials. The atomic configuration of a compound must be known before the various physical and

chemical properties of the material can be understood. One of the most

powerful methods of determining the atomic positions of complex compounds is that of single crystal X-ray diffraction. Since this technique was previously limited because of the time-consuming computations

required, the Bureau's electronic computer was recently programed to calculate electron density maps for any of the 230 crystallographic space

groups. Standard X-ray Diffraction Patterns. In cooperation with the

Joint Committee for Chemical Analysis by Powder Diffraction Methods,

a continuing program for the preparation of standard X-ray powder

diffraction is being carried out for the Powder Data File. These data are widely used in research and industry as a rapid and accurate method of identifying crystalline phases. During the past year 54 standard patterns were published, replacing 40 cards in the File, and adding data on 24 new compounds. The eighth volume of NBS Circular 539 (Standard

X-ray Diffraction Powder Patterns) is in press. Because many of the powder samples are unstable in the ordinary

atmosphere, they must be protected when transferred from a conditioned

dry box to the X-ray diffractometer, and during exposure to X-rays.

To eliminate this interference, a controlled-atmosphere specimen holder was designed. This cell consists of a spherical metal chamber with a transparent plastic window to permit X-ray penetration. In assembly,

the sample is mounted in the center of the cell and the cell is bolted shut. Because of the simple operation, the cell can be conveniently assembled

directly in the dry box and then moved to the diffractometer.

The demand for improved high-temperature materials has put special emphasis on the study of the properties of materials at high temperatures.

Typical NBS studies include the melting behavior of ceramics (right), and

the effects of high temperatures and high pressures on crystallization (left). 60
Radiation Control for Rockets and Satellites. Radiation is the

only mechanism of heat transfer to or from a satellite or other vehicle

traveling in outer space; hence the energy absorbed and radiated by the outer skin material will control the heat balance and the equilibrium

temperature achieved by such a vehicle. This control is essential to ensure satisfactory operation of the electronic components of current

satellites, and will be even more critical for the manned space vehicle of

the future. Data on heat radiation or emittance properties are thus

urgently needed not only on materials for vehicles in outer space but also on materials for aircraft and missile components operating within the

atmosphere.

For these reasons equipment was designed for the Army Ballistic Missile Agency to evaluate total hemispherical emittance by modifying

the hot filament method. Data were obtained over the temperature

range 100° to 1,100° C on the total hemisphere emittance of three alloys

of interest to the current rocket program at the Redstone Arsenal.

Equipment was also designed for the evaluation of normal spectral

emittance of coated and uncoated metal specimens over the temperature

range from 350° C to slightly below the melting point of the alloy, and

over the wavelength range 0.3 to 40 microns.

Mechanism of Ceramic-Metal Adhesion. Although strong bonds

between ceramic materials and metals are essential for the successful manufacture of such diverse products as electronic tubes, fluorescent

lights, and porcelain-enameled architectural panels, no widely accepted

theory to explain the bonding mechanism has been established.

Experiments performed at the Bureau several years ago showed a

correlation between roughness of interface and adherence of porcelain

enamels to steel. When similar enamels were applied to stainless steel, however, a good bond was sometimes observed without any detectable

roughening of the stainless -steel surface. In recent experiments, a relatively simple ceramic -metal system was

studied in an attempt to discover some of the basic factors responsible

for bonding. Small gold pellets were melted on polished silica plaques in a furnace with varying oxygen content. After the samples were cooled

to room temperature, the bond strengths were determined by measuring

the force required to shear the pellet from the silica surface. Results

showed that bonding occurred only when oxygen was present, and that

bond development was independent of the degree of wetting.

A second type of test using radioactive gold (Au198

) as a tracer showed

that bonding occurred only when gold diffused into the silica lattice. Electron micrographs indicated that a good bond could develop without

appreciable roughening of the interface. Glass Transition Temperatures. In studying or using glass-forming materials, it is necessary to define a transformation temperature above

which the material is considered an undercooled liquid and below which it is considered a glass. Since the transformation from an undercooled liquid

61
Gold pellets fused on silica plaques in a high-temperature furnace are used

to study the strength of ceramic-metal bonds. When the pellet was sheared

from the silica surface (right), fracture occurred in the glass rather than at the interface, showing good bond strength (page 61).

to glass is probably controlled kinetically rather than thermodynamically,

the value of the transformation temperature for an material will vary

slightly. Because the accuracy with which a scientifically useful value of

this temperature can be defined is of scientific importance, an investigation was started on various glass-forming materials representative of the

vitreous state in general.

Current measurements are on mixtures of calcium nitrate and potassium

nitrate. The glass transformation temperatures are determined as the

temperature at which the slope of the volume-temperature plot changes

when the material reverts from the undercooled to the glassy condition

or vice versa. This temperature is determined for various rates of cooling or heating.

Chemical Analysis of Cements. X-ray fluorescence methods

which give in a few minutes results comparable to those requiring hours to obtain by other analytical methods—were adapted for determining the

major constituents of portland cement. Studies were made on the suit- ability of various analyzing crystals and detectors as well as on the effec- tiveness of pulse -height discrimination and helium paths for detection of

calcium, silicon, iron, aluminum, manganese, magnesium, and sulfur. The method may prove to be a valuable tool for routine production-control

testing.

Coatings for Supersonic Vehicles, Vehicles traveling at supersonic

speeds within the atmosphere are subject to severe heating from atmospheric friction. Because high temperatures are detrimental to essential metallic components, the heat must be disposed of without allowing the

components to become excessively hot. One solution to this problem is to provide coatings that will withstand high temperature, have low ther- mal conductivities, and have a high capacity to radiate the heat generated

in them At the request of the National Advisory Committee for Aero62
nautics, a new type of coating was developed by the Bureau to meet these requirements. This coating was prepared by mixing inert ceramic fillers with an aqueous solution of monoaluminum phosphate. Hardening and

moisture stability, requirements necessary for airframe materials and

assembly procedures, were achieved by curing for 2 hours at 400° F or

for % hour at 600° F. Refractory Castables. Because refractory castables are suitable for use over a wide range of temperatures, they are being utilized in a variety

of installations including ballistic missile take-off pads and jet warmup

aprons. These castables consist essentially of a mixture of a heat-resist- ant aggregate and a hydraulic aluminous cement—which becomes resist- ant to temperature changes when combined with water, cured, and dried. At ordinary temperatures the hydraulic bond of the cement holds the

castable in a rigid shape. As the castable is heated, the hydraulic bond

gradually changes to a ceramic bond, with a consequent change in mechanical properties. To better understand the mechanisms involved in these

changes, an investigation of the physical and chemical properties of alu- minous cement and its components was undertaken during the past year. From the data obtained in this study a schematic diagram was constructed to illustrate the major changes in mineralogical composition

which probably occur during the hydration and subsequent heating of

aluminous cements. Comparison of this diagram with corresponding

transverse strength, dynamic modulus of elasticity, and thermal expansion values showed that a definite correlation existed between the mineralogical composition and these mechanical properties.

Standard Glass for Measurement of Physical Properties.

Standard glasses that can be used for calibrating instruments which measure viscosity, surface tension, or other properties of glasses at ele- vated temperatures are needed by research laboratories. Also needed is a series of simple two- and three -component glasses that can be used for studying the structure and constitution of glass. For these reasons, measurements on the properties of soda -lime -silica glass, which will be

the first of the standard glasses, is under way and measurements of vis- cosity in an intermediate temperature range have been made. In addition, apparatus suitable for precise measurements up to 1,450° C was

constructed.

2.10. Building Technology

The Bureau conducts research in the fields of chemistry, physics, and

engineering to assist the building industry in making advantageous use of scientific knowledge and techniques. 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 belnu ior 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 year significant improvements were made in the precision

of measurements of the thermal conductivity of metals over the range —150° to 750° C; a new technique was developed for determining the self- ignition properties of materials; substantial progress was made in developing methods of testing and new design criteria for underground insulated

pipe; further progress was made in developing methods for separating

asphalts into their components and in applying chromatographic and

spectrometric techniques to studies of the chemical and physical processes of asphalt deterioration; and a contribution was made to a better understanding of the mechanisms of diagonal tension failures of reinforced concrete structures. Fire Hazards of Common Combustible Materials. Because of

the complexity of the behavior of fires and the lack of understanding of

the mechanisms of either the growth or the inhibition of fires, only

arbitrary methods for measuring the fire hazard properties of materials

have been available. However, significant progress was made during the

past year in measuring the ignition properties of solids and liquids by means of an adiabatic furnace. The kinetic reaction constants measured

in this manner can be used for predicting the size of pile and the ambient

temperature which may be considered safe for the storage of combustible

material over prolonged periods. Such information is of value not only

to manufacturers and others concerned with transporting and stockpiling

ordinary materials, but could help determine safe conditions for storing

rocket fuels and explosives.

Four devices for measuring and evaluating fabric flammability are shown

left to right: Vertical test for flame resistance, British semicircular test, horizontal flame spread test, and inclined flammability test (page 64). 64
Fire Retardants for Fabrics. A study of the effectiveness of five fire-retardant treatments for fabrics was completed, and the methods

used for measuring retardancy were reconsidered.

Fabrics studied included cotton and rayon textiles of various weaves and color. Although they provided a considerable range in finish and

weight, four of the five fabric samples were considered well suited for fire-retardant treatments. Of the seven different treatments applied to the fabrics, all tended to stiffen the fabrics, some slightly, others severely.

A simple water-soluble treatment was as effective a fire retardant as any, but other treatments tended to retain their effectiveness better after laundering. The data disclosed not only a lack of concordance between

the results of flame resistance tests made by different methods but also the need for research to develop better methods to measure the fire hazard properties of fabrics. Standardsfor Refrigerated Trailers. A method for determining the

cooling load of refrigerated trailers is currently under study in a program

sponsored by the Truck-Trailer Manufacturers' Association, the U. S. Department of Agriculture, and the Quartermaster Research and Engineering Command. The objective is to develop a standard laboratory

rating method that can be applied to refrigerated semitrailers under

simulated road conditions. At present no standards exist for rating truck

and trailer bodies for heat transfer, moisture gain, and air leakage, nor

Specially equipped tractor used to develop standard lest methods for deter- mining the heat transfer and air-moisture leakage of refrigerated trailers (page 65). 65
for rating the refrigerating units that cool them. Insulated bodies and

refrigerating units are matched largely by empirical rules even though

this type of transportation represents a one-hundred-million -dollar a year

industry.

The importance of air leakage and moisture transfer on a total cooling

load was shown by comparative laboratory and road tests. The pathways

and mechanisms of air and moisture movement appeared to be controlled

principally by the air pressure pattern produced around the body when

in motion. The proposed rating procedure consists of a laboratory meas- urement of the steady state heat transfer rate of a trailer, determined

while the interior is maintained at 0° F, the ambient conditions are 100° F

dry bulb temperature and 50 percent relative humidity, and with a static

air pressure on the nose of the trailer simulating the ram air pressure at a road speed of 50 mph.

Underground Pipe Insulation. For the past several years the

Bureau has been studying methods for insulating underground steam and

hot water distribution systems under the sponsorship of the Office of the Chief of Engineers, the Bureau of Yards and Docks, and the Air Force. The investigation is intended to provide data on the insulating properties,

water permeance, expansion characteristics, and chemical and mechanical

stability of insulating materials and on the principles of simultaneous

heat and moisture transfer in insulating materials and soils under simulated service conditions. Although this project is not yet completed,

sufficient data and information have been gathered to serve as a basis

for tentative criteria to design a good protective system for underground

heat distribution piping. These criteria were used by various Federal

agencies as the basis for writing new specifications that will be essentially

uniform in their requirements.

Conductive Flooring in Danger Areas. Sparks resulting from the

accumulation of static electricity constitute a danger when explosive

vapors are present. An effective means of mitigating this hazard lies in keeping the electrical resistance between objects in the hazardous loca- tion so low that dangerous sparking potentials are never attained. Most

objects normally rest or move upon the floor and therefore can be elec- trically connected by way of the floor if it has sufficient electrical conductance. In cooperation with agencies of the Department of Defense, all types

of conductive flooring materials recommended for use in hospital operating

suites were evaluated in the laboratory and in the field. This included

investigating instruments a ad methods pertinent to the testing of conductive flooring. A report on electrical and nonelectrical properties, and a proposed purchase specification were prepared for eight types of electri- cally conductive flooring materials.

Degradation of Asphalt. In the course of the Bureau's studies of the mechanism of asphalt degradation this year, asphalts were separated

into their components and the components were weathered separately

66
and in different combinations. Changes due to weathering were observed

by infrared spectrometric and other techniques, and a technique was

developed for taking infrared spectra of whole asphalts, using films from

1 to 2 mils in thickness.

The effect of a number of antioxidants on the weight losses and durabilities of asphalts exposed to accelerated weathering was determined, and

a study of the relationship between the physical properties and component

distribution of an asphalt during the blowing operation showed that the

softening point and asphaltene content increased linearly with the time

of blowing. Other work indicated that of two asphalts having essentially

the same physical characteristics, the one with the lower asphaltene content had the gieater durability on exposure to the weather.

Strains in Reinforced Concrete Beams Having Diagonal Cracks.

In cooperation with the American Iron and Steel Institute, beams of

unusually small ratios of span to depth were investigated when loaded

to cause failures by diagonal tension. Numerous measurements of strains showed that, after the formation of the typical diagonal cracks, the

maximum longitudinal compressive strains occurred between the extreme

fiber and the neutral surface rather than at the extreme fiber as predicted

by theory. This result implies distortions of sections that were originally

plane. The strains also indicate that longitudinal reinforcement of large

bars resists a significant part of the external shear after the formation of

a diagonal crack. However, the shearing force in the bars decreased

rapidly as the load approached the maximum, and the evidence available

indicates that the shearing resistance is not of practical significance

except for beams of unusually small ratio of span to depth.

Drying Shrinkage of Concrete Masonry Units. To develop an

improved, rapid method of determining the drying shrinkage of concrete masonry that indicates the potential shrinkage under service conditions, a study was made of the shrinkage characteristics of concrete units. Tests on autoclaved and low-pressure cured blocks of several different aggregates showed that the shrinkage may be determined rapidly at room

temperature by the use of thin laminas removed from concrete units at right angles to the face shell. The shrinkage of the thin laminas correlates well with that of the control specimens of full-size blocks under the same

exposure conditions.

Moisture in Insulated Roof Constructions. Moisture in the insulation of insulated roof deck constructions reduces their insulating value

considerably, causing heating and air conditioning loads which exceed

design estimates based on dry materials. Moisture may exist in roof

insulation, either because it was present initially when the roofing was

applied, or because it had entered through leaks in the roofing. In an

investigation for the Department of Defense, specimens of typical root* constructions were exposed to simulated winter and summer daily solar heating. The results show little tendency for the moisture to be expelled.

However, some types of construction that allow vapor flow through the 67
An improved method for determining the drying shrinkage of concrete masonry is being studied. The shrinkage of a thin lamina (left) was found to correlate well at a relative humidity of 30 percent with that of the full-sized blocks (right), and can be measured in a much shorter time (page 67). undersurface of the structures recovered their insulating values markedly

during a summer test exposure condition, even when the initial moisture

content was high. The investigation is therefore being directed toward

development of information on designs and factors which promote the

self-drying of roofs in service. Thermal Conductivity of Metals. To satisfy requests from Defense

Agencies and industrial laboratories for accurate measurements of the

thermal conductivity of metals over a wide temperature range, the Bureau's existing apparatus was modified to permit measurements at temperatures from — 150° to 750° C. At the same time, the apparatus

and procedure were modified to permit calculations of the final results from observed data by means of the IBM 704 computer. These changes

have significantly increased the precision of the measurements while

reducing substantially the time required to make them.

Capacity of Horizontal Plumbing Drains. Experiments were con- ducted to determine the flow capacities of nominally horizontal drains

under conditions of surging flow, such as actually occur in plumbing

drains in service. The findings provide a basis, useful to design engineers

and code writers, for significant changes in design procedure which can

result in appreciable savings of materials and labor in plumbing

installations. 68
2.11. Applied Mathematics

The Bureau maintains a central applied mathematics facility which

conducts basic and applied research and renders advisory services in various mathematical fields. The services of the applied mathematics

facility are available both to the Bureau's technical staff and to other

government agencies. Equipped with modern computing aids, including

high-speed digital computers, the facility has played a significant sup- porting 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.

During the past year, the applied mathematics facility placed research

emphasis on statistical and numerical analysis and mathematical physics. In addition to consulting services in applied mathematics, including

mathematical statistics, extensive attention was given to problem formulation and analysis to determine and, if necessary, develop numerical

methods for the solution of problems on automatic and nonautomatic

computing machines.

Approximation Theory. The numerical integration of periodic and

analytic functions was compared by means of the trapezoidal rule and the

Gaussian rule. It was discovered that the efficiency of one rule over the

other depends strongly upon the singular behavior of the integrand in the

complex plane. Therefore criteria were developed for determining which

rule is the more efficient for a given integrand. In addition, preliminary

theoretical studies were undertaken of the relative accuracies of polynomial approximation and rational approximation to a given analytic

function. A digital computer code which permits calculations of the best (Chebyshev) polynomial approximation to a given function resulted from this work.

Studies were also made of a method of summability recently proposed

by Lototskii. An attempt is under way to generalize Lototskii's results and to determine possible areas of application to numerical analysis.

Matrix Code Studies. In a program lor testing matrix codes,

sponsored by the David Taylor Model Basin, the precision of inverting

matrices is being correlated with their p-condition number. A collection of a dozen representative matrices with a large spread of p-condition

numbers was subjected to a variety of codes on various computing machines throughout the country. A comparative study was made of the

results and significant information was obtained about the correlation. The same program will be carried out with codes for eigenvalues and

eigenvectors. Under the sponsorship of the Office of Naval Research,

further results were obtained on the location in the complex plane of the eigenvalues of matrices, and extensive research was conducted in other

mathematical topics applicable to numerical analysis,

69
Eigenvalue Theory for Differential Operators. In eigenvalue

theory for differential operators, significant progress was made, both

theoretically and numerically. Application of Aronszjan's theory of

bounds to symmetric operators with a perturbation term was carried out and the method was used to find lower bounds for simply excited and bound

energy levels of helium and lithium. Numerical estimates are being obtained with a computer code which evaluates the integrals that intervene.

Mathematical Tables. Work was begun on the preparation of the

Handbook of Mathematical Functions with the support of the National

Science Foundation. The volume is designed to cover the entire field of special functions and will contain methematical properties, graphs,

and comprehensive tables. Each chapter—devoted to a special function—lists in detail the mathematical properties important in computation and includes a section on numerical methods to illustrate the use and

extension of the mathematical tables. Graphs are provided to describe

the analytic behavior of the functions. Also included in each chapter

are pertinent definite and indefinite integrals, infinite series, inequalities,

differences, and differential equations, together with a list of references to primary sources. As a result of the Bureau's program of computing mathematical tables of wide-spread interest and importance to the physical, chemical, and

engineering sciences, tabulation of the exponential integrals of complex

arguments was published, a table of natural logarithms for arguments

for 5 to 10 decimal places was revised, and compilations of Airy integrals

and Sievert's integrals reached their final stages.

Digital Computation. The availability of a modern electronic computer (the IBM 704) has contributed to a considerable growth in the Bureau's computation program. For example, spectrum analysis computations were reprogramed in a more extensive form and established as a routine problem, and crystal structure calculations were modified to include a complete program for three-dimensional Fourier series summations. Other projects also placed on a routine production basis include

the evaluation of thermodynamic functions, optical ray tracing, thermometer calibrations, electron penetration, computations for colorimetric

problems, thermodynamic properties of gases, calculations for J-spacings,

nuclear scattering of photons, and crystal structure calculations. Additional problems programed include the study of a magnetic field from a

local source in a thin ferro-magnetic sheet, computation of hydraulic

elements for circular pipe sections, determination of viscoelastic properties

of materials, calculations of the response function in the measurement

of the energy spectrum of rays, and the NBS payroll calculations.

Reliability Studies. Research on statistical aspects of the reliabil- ity of components and assemblies led to the formulation of mathematical

models for the analysis of experiments on the aging of components.

Methods for estimating the pertinent parameters in these experiments were worked out. This work, which is applicable to a variety of aging

70
Automatic reduction of spectral reflectance data into colorimetric and Munsell terms by high-speed digital computer has accelerated the work in color- imetry and photometry (pages 17, 70). studies, formalizes and improves methods of analysis that have previously

been based on intuitive grounds. A method for making multifactor

studies in life -testing programs was evolved for use in studies where the

experimenter can preset certain environmental factors affecting per- formance. Investigation of mathematical models to describe inter- dependence of components continued, with particular attention given

to the resulting needs for new data on failure and reliability.

Experiment Design. The use of factorial designs has now become

widely accepted as an efficient way for carrying out experiments involving

many different factors. However, one of the main difficulties with

factorial designs is that the number of measurements required maybe

large and in some cases prohibitive. Another disadvantage is that in many experimental situations it is not practical to plan an entire ex- perimental program in advance. Instead, the program is restricted to a small experiment which serves as a guide to further work. This condition is especially true when measurements are made singly or in small groups, in such a way that the experimental results become known

sequentially as they are taken. There are presently available catalogs

of the 2

n series and the 3

n series, but not of the 2m 3

re mixed series. Therefore, a method involving the direct product of matrices was developed for the analysis and for use in construction of fractional replicates of the 2m 3" mixed series designs. This method greatly simplifies the formation of

the normal equations for the design and reduces the analysis to manageable

proportions. With this new development, the construction of a catalog

of such designs was begun under the sponsorship of the Bureau of Ships.

71
Continuum Mechanics. In fluid -mechanics research for the Office of Naval Research, the Stokes flow problem was solved for several axi- symmetric bodies not hitherto considered, and certain new theorems in the theory of Stokes flow were proved. An exact solution of the problem

of the unsteady water wave in a straight channel of arbitrary slope was

given; previously, only numerical solutions for this type of problem have

been available. A particular case worked out in detail specified a wave

produced by the sudden release of a triangular wedge of water (the

dam-break problem).

Work in elasticity for the Air Research and Development Command

was for the most part concentrated on the theory of plates and shells. Work on the bending and stretching of corrugated diaphragms was

completed. This analysis may be considered the most accurate available on this subject and has important applications in the field of instrumentation. A study of the bending of elastic plates of variable thickness was

started; in particular, the circular plate with variable axially symmetric

lateral load is under consideration.

Theory of Orbits. In connection with the Office of Basic Instru- mentation, a study of the influence of the "rotation wind" on the in- clination of the orbit of a satellite was instituted. This investigation may

be broadened into a more elaborate study of the transition from an

elliptic to a ballistic missile orbit. 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 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.

SEAC as a Research Facility. The experimental modification, operation, aud maintenance of SEAC has been a continuing responsibility.

Since it was reoriented from a scheduled scientific computational facility to a research and development tool for new computer systems and specialized areas of application, the memory has been expanded to 2,048

words to facilitate try-outs of larger-volume data -processing problems.

During the past year, provision was made for parallel input -output with

alphanumerical representation, and for handling information from the

analog computer. A high-speed photoelectric paper tape reader and

punch were incorporated in the system. Testing of the versatile high72
speed multichannel magnetic tape system for parallel input and output

is in process. Analog Computers. The analog computer is an additional facility for the solution of problems in connection with the Bureau's scientific programs and also an important part of the simulation facility for solving

various problems in simulation of physical systems. It was augmented

by two new GEDA function generators and one 6-amplifier summing

unit. For the large X-Y plotter, an rf pickup was procured, simplified

modal conversion was arranged, and a sampled-data smoother was de- signed and constructed.

Pilot Electronic Data Processor. The system design plans for the new NBS Pilot Electronic Data Processor are now virtually completed,

and the engineering necessary for its physical construction is under way.

This general-purpose system is suited to the processing of digital information at very high speed, and when completed is to be utilized for experimental investigations on a wide variety of large-scale problems of special

importance to the Government.

To enable the machine to be used as a research tool for such varied purposes, the system was designed to include a number of different characteristics that are not ordinarily associated with one machine, such as high computation rate, flexibility of communication with the outside,

and a wide variety of internal processing operations. The system contains three independently operating computers, each of which is specially

adapted for performing certain special classes of operations that frequently occur in large-scale data -processing applications. The system thus pro- vides a working model of an integrated multiple -computer network.

Components and Techniques. Under the sponsorship of the Air Force Cambridge Research Center, instruments were constructed to perform

measurements on samples of new switching transistors; transistorized

read, write, and control circuits for magnetic tape input -output searching

systems were developed, and the transistorized diode -capacitor memory

was tested. In addition, work on the d-c stability and drive capabilities of an Eccles-Jordan transistor flip-flop, and on the development of a highspeed or-inverter circuit was completed. Studies were made on the

measurement and equivalent circuit characterization of diffused transis- tors at very high frequencies and large signals to establish a basis for predicting accurately the performance of high-speed switching circuits. Samples of new types of switching transistors and related components

were procured and tested. Characteristics of these commercially avail- able transistors were then coded and punched into cards to facilitate selecting those types satisfying given specifications.

A trapped-flux memory using evaporated superconducting films was

studied. In addition to basic studies in superconductivity, photo-resist

techniques in forming tiny intricate masks for multilayer evaporations were investigated. Work continued on the study of evaporated ferro- magnetic films for uses as elements in a coincident current memory arra\

73
Under the sponsorship of the Office of Naval Research, studies were made on transistor nor-circuit design, the design of a parallel adder with

nor-circuits, and some aspects of the theory of asynchronous circuits. Transistor-Magnetic Core Circuitry. The transistor-magnetic core

circuitry, developed under the sponsorship of the Department of Defense, was refined and completed during the year. Circuits were specifically

designed to perform the logical and switching functions of the central portion of a digital computer. Three basic packages, for gating, pulse

repeating, and complementing, were designed to perform all required

computing functions, and with these modules a small system was designed

for testing the over-all operating margin of an array of the packages.

The results to date have shown highly reliable operation.

Rapid Selector. Under the joint sponsorship of the Patent Office and the Bureau of Ships, the rapid selector, originally designed by Yale

University, was completely redesigned using computing techniques.

This development is intended to retrieve rapidly information from

massive files of correspondence, drawings, patents, and similar matter

which has been transferred to 35 -mm film. Its optical and mechanical

systems were improved and the detecting and related electronic inter- rogating system was redesigned. As a realistic testing ground for the

device, a master film using articles from the NBS Technical News Bulletin

series was prepared using a high-efficiency coding system. The present

laboratory prototype is being tested to determine the reliability of the

modified circuitry.

Among the advances made in computer components and techniques (page

75) were a computer shift register that utilizes the NBS diode-amplifier

technique, left, and a low-power plug-in tube, right.

74
Digital Systems Research. Research on the problem of using an

existing computer to work out the design details for a new and more

advanced computer has reached the point where a large-scale practical

test can now be run. A complete procedure was formulated for mechanizing the work of converting system design plans into printed tables that

specify the exact point-to-point wiring interconnections and other

detailed data needed for constructing an actual machine. To provide a

rigorous practical test of this procedure, it is currently being employed

to convert the system design plans of the new NBS Pilot Electronic

Data Processor into fabrication data for constructing the new machine.

An investigation of the problem of harnessing several computers into

a network of machines is now under way to try to meet the extreme

requirements in computing speed and data storage that many important

future computer applications will demand. Since such requirements

are beyond the capabilities of any single machine using currently available

technology, methods must be developed for organizing several machines

to work cooperatively on a common task. The initial investigation was

directed toward evaluating the efficiency of several schemes by which the

independent computers in the network can share a common workload.

Various models were devised for simulating the behavior of pairs of

computers working together and exchanging information, and their

relative operating efficiencies were calculated. A number of automatic

control schemes were devised for solving the problem of interlocking a pair of computers, and one of these schemes was chosen for use in the

system of the NBS Pilot Electronic Data Processor. Advanced Computer Systems. Technical advice and assistance were provided to the Aberdeen Proving Ground's Ballistic Research

Laboratories on the design of the BRL digital computing and dataprocessing installation. Specifications were formulated for various

multi-purpose calculating and processing units in the BRL system, and

detailed logical diagrams were devised. Assistance was also given on the

specification and procurement of component packages and high-speed

magnetic-core memory units. Man-Machine Systems Simulation. The simulator facility for research on man-machine systems, begun in 1957, was completed and a

test problem was performed. The machine simulates the interactions

between electronic control systems and a team of human operators.

Sponsored by the Wright Air Development Center, this protot) pe includes a digital computer (SEAC) and an analog computer, [inked with

display and control equipment which permits human beings to be coupled

into the system. In the facility the analog computer performs such tasks as accepting continuous control information, solving complex dynamic

equations in real time, and activating conventional display devices. The

digital computer controls the experiment, generates open loop data,

calculates with high precision, handles variables requiring large dynamic

range, makes logical decisions, and statistically analyzes experimental

489867—59 6 75
In a continuing program to aid the Post Office with its mechanization problems, a laboratory prototype machine (above) for high-speed sorting of letter mail was developed under the Bureau's technical supervision. A preproduction model is now under construction (page 77). results. As an example of a high-performance sampled-data system

involving human operators as components in a control loop, the ground- controlled interceptor problem was chosen for the first studies. Data from the prototype machine form the basis for determining the

feasibility and estimating the cost of a more elaborate laboratory installation. This type of facility will permit both operational and dynamic

analyses of complex and expensive systems involving human beings in control loops, such as those used for interdiction and interception, missile assignment and guidance, and air traffic control. Aircraft Flight-Loads Data Processing. Under the sponsorship of the Navy Bureau of Aeronautics, a study was initiated to establish

detailed plans for a computing facility to automatically edit, reduce, and

process flightload data collected from military aircraft in normal flight

operations. The objective of this data processing is to provide information for structural design and safety criteria based on maneuvers of

operational aircraft during the various types of service missions.

Data Processing Applications. In connection with encouraging

maximally efficient application of automatic data processing techniques

to the massive information handling problems encountered in Government operations, feasibility analyses were made of generic problems

common to such agencies. Typical problems under study included file maintenance, stores accounting, capital equipment depreciation accounting, and report generation. In addition, problems of data preparation

and input were investigated and a survey of the art of automatic character

recognition was completed.

76
Under the sponsorship of the Public Housing Administration, programs

were developed for the IBM 704 Computer to check the eligibility reports

of occupants of 400,000 units of low-rent housing.

The first phase of a study of the Naval Aircraft Operating Program and

the effects of program changes upon maintenance supply support was

completed for the Navy Bureau of Supplies and Accounts. This first phase was an examination of the aircraft inventory, the aircraft program

operations which cause changes in inventory due to program and to extraneous causes, and the maintenance and supply support expressed

as a function of an operating program.

Continuing research in collaboration with the U. S. Patent Office for the mechanization of patent search operations has resulted in an expanded

and improved program for comprehensive search of chemical patent

literature. In addition a search program was developed and is being re- fined for general searcn, with emphasis on mechanical arts. Modifications

to make SEAC a more effective searching tool are nearing completion.

A survey of recent advances in techniques applicable to the development

of automatic machine techniques to aid in searching technical literature was initiated in the following four areas: (1) Information sources,

(2) communication theory and information processing, (3) mathematical

logic and abstract algebra, and (4) automatic and artificial intelligence.

The findings of the survey will provide the nucleus of an information

center whose major objective is to make such scientific information

generally available within Government.

Under the sponsorship of the Department of Defense, work was initiated to develop star counting techniques, utilizing automatic scanning of

photographic data and computer processing. Following studies of the

reliability of the scanning equipment, modifications were made in the

apparatus, the logical requirements for an iterative operation for counting

the number of stars in a field were developed, and a trial program was

written.

Processing First- Class Mail. The operations analyses of mail

handling in post offices have continued with the concurrent development

of elements of an automatic mail sorting system under the sponsorship

of the Post Office Department. Analyses of the distribution of outgoing

mail for typical large cities and of the physical characteristics of lettersize mail were made. Address coding plans were developed and tested on an electronic computer to determine duplications among 38,000 Post

Office names. Data on incoming mail operations are also being assembled

for analysis.

The development contract for laboratory prototype elements of a proposed mail sorting system was completed midyear, and contract negotiations were concluded by the Post Office Department lor the

development and construction of a preproduction model of a complete

system, under the Bureau's technical supervision. This equipment is

77
under construction and will soon make possible operational tests under

actual working conditions.

Contracts for developing improved sorting equipment elements and

for a cost analysis of a proposed electronic directory were also negotiated,

and technical analyses were made of several proposals submitted by

industrial concerns.

Six machines which simulate mail coding stations were completed by

an outside contractor using the Bureau's design. With the technical

assistance and expert advice of staff members of the Bureau these were

put into use for keyboard-code-operator experiments in the Washington

Post Office. A series of human engineering tests, supervised by a contractor competent in psychological studies, are in progress to provide

data for determining equipment parameters when these machines are operated by differently qualified personnel. (Other aspects of the mailhandling problem are discussed on p. 155.) 2.13. Cryogenic Engineering

The Bureau's cryogenic engineering program, located at the Boulder

laboratories, is designed to provide information for the practical application of very low temperatures to both Government and industry faced

with problems in this rapidly growing specialized field. To carry out these objectives research is conducted on the properties

of materials at low temperatures, on cryogenic processes, and on cryogenic

equipment. The demand for advisory services by both industry and

other government agencies has greatly increased as a result of rapidly

accelerated programs dealing with long range missiles and space vehicles. All vehicles that are now in service and most of those planned utilize lowtemperature liquids as propellants. A noteworthy example is the nuclear

powered rocket now under development which will be propelled by liquid

hydrogen.

Low Temperature Liquids. The Bureau conducted investigations

into the use of liquid oxygen in a missile tank concentrating on instru- mentation for the accurate determination of the amount of liquid oxygen

aboard during standby, miscellaneous heat transfer problems connected

with transferring the liquid oxygen to the missile, the generation of

electrostatic charge during transfer, and the effect of violent vibrations on the liquid oxygen.

Other work included the design of cryogenic equipment, such as the

helium liquefier which was put into operation during the past year. The

liquefier is providing enough liquid helium to meet all the present requirements of the Boulder laboratories as well as 45 to 50 liters per week for use in free radical research at the Washington laboratories. Another

piece of apparatus completed is a distillation column used to study the

feasibility of separating deuterium from ordinary hydrogen. This distilla- tion column is expected to provide valuable data to designers of largescale equipment for producing deuterium or heavy water. 78
This distillation column, designed to investigate the separation of deuterium

from ordinary hydrogen, is expected to provide valuable data for designers of

large-scale equipment for producing heavy water (page 78). Cryogenic Engineering Data. To make generally available the

techniques of cryogenics to engineers and other research workers, a book

on the subject of cryogenic engineering is under preparation. In a further

effort to meet the demand for technical information a Cryogenic Engineering Data Center was established. The center is compiling an organized

index of published literature applicable to the cryogenic engineering field. Flow of Liquefied Gases. Single-phase liquefied gas flow studies

consisted of theoretical analyses aimed at providing a basis for designing

long transfer systems in which single-phase fluid flow could be maintained. Two-phase flow work was confined to experiments planned to provide a basis for the design of transfer systems in which both liquid and

vapor phases are present. This work showed that the pressure drop in steady, two-phase, single -component fluid flow can be predicted from the

Lockhart and Martinelli correlation if simple corrections are made to account for changes in the axial component of momentum.

79
Both theoretical and experimental work was performed to evaluate the

behavior of sharp -edged orifices as flow meters for liquefied gases. The

experimental work indicates that these devices can be used with confidence

with cryogenic liquids as long as pure liquid enters the device—a limitation common to all volumetric flow meters. The theoretical work was designed

to predict the discharge coefficients which were obtained empirically

before. Results obtained thus far appear to account for previously unexplained observations.

Storage of Liquefied Gases, Several innovations in the design of mobile containers for liquefied gases were incorporated in a liquid oxygen

container for the Wright Air Development Center. This container has

a predicted heat leak which may be as little as one-quarter that of present

containers for similar applications. Its successful storage ability results from such design considerations as the utilization of the load-bearing

qualities of evacuated powder insulation and the use of plastic materials

for support members.

A cryostat, developed for the Air Force Cambridge Research Center,

maintains a superconducting resonator at liquid helium temperature

for over 40 days without service or maintenance of any kind. One of the

novel features of this cryostat is a mechanism which permits the tuning

at any time of the resonating cavity from outside the cryostat.

Experimental work during the development of vacuum-insulated transfer lines for liquid nitrogen demonstrated the feasibility of using "condensing-type" vacuum insulation. The advantage of this system is that

vacuum-insulated equipment may have long shelf life even though it contains leaks which would ruin conventional vacuum (Dewar) insulation. This work was undertaken with the support of the Rocket Engine Test

Station, Edwards Air Force Base, Calif. Hydrogen Refrigeratorfor Bubble Chamber. For the past 3 years

assistance has been given to the University of California Radiation

Laboratory in the development of liquid hydrogen bubble chambers.

Liquid hydrogen refrigeration is required for continuous operation of the

bubble chamber. During the past year an 1,800-watt hydrogen refriger- ator was built in accordance with basic NBS designs. It will soon be

assembled as part of the bubble chamber unit at UCRL.

From this work resulted a new procedure for use in the design of high- pressure heat exchangers of the type usually employed in low-temperature

processes. An effort was made to balance the flow and therefore increase

the efficiency in a given heat transfer area. Results of refrigerator per- formance tests gave initial verification to the new design procedures.

Helium Liquefaction. In giving assistance to the Navy Bureau

of Aeronautics in its plan for the liquefaction and distribution of helium,

the best designs possible were made of liquid helium containers in sizes ranging from light, transportable units to large road-transportable trailers and rail tank cars. Weight and no-loss storage time were the primary

considerations of these design optimizations. Studies of helium gas

80
The transport of large quantities of cryogenic fluids is of increasing importance. This 6,000-gallon transport vessel for liquid parahydrogen is four times larger than any previous unit (page 80).

liquefaction processes that were made during past years are now being

used by the sponsor and by the U. S. Bureau of Mines in the procurement

of liquefaction facilities. Low Temperature Properties of Materials, It is well known that

certain of the austenitic stainless steels (300 series) partially transform to martensite on chilling, especially if they have been cold-worked. Because

of the widespread use of these steels in cryogenic equipment, it was

desirable to study an unexplored aspect of this transformation, namely its slow continued occurrence during long exposure to a constant low temperature. Magnetic analysis is being used to investigate the occurrence of

such changes. In the course of the Bureau's program of measuring mechanical and

thermal properties useful in low-temperature engineering and research,

determinations of the ultimate, tensile, yield, and impact strengths of a group of commercial magnesium alloys were made. These measurements

indicate that these alloys have only limited special uses in cryogenics

because of their low impact strengths. Investigations of a relatively new aluminum alloy of promising characteristics showed that deformation

at slow strain rates occurs by repeated sudden yielding. Ultimate and

tensile strength, shear modulus, and Young's modulus were measured on

a group of plastic foams. These properties together with the thermal

expansion coefficient are sufficient to determine the ability of bonded

foam insulations to withstand thermal stress. The thermal conductivities of two copper-silver alloys were measured.

These, with the high -purity copper measured earlier, formed an alio)61
series with graded silver content. Separation of the ideal and defect thermal resistivities for each sample showed a new effect, the existence

of a residual term representable as a cross product of the two resistivity

components, as was predicted theoretically by Sondheimer.

Tentative temperature -emf reference tables for gold-cobalt versus

copper, gold-cobalt versus silver -gold, and copper versus constantan

thermocouples were derived from experimental measurements down to to 4° K. These thermocouples are important as practical low-temperature

thermometers of moderate accuracy. Gas Liquefaction. This was a record year in the production of

liquefied gases. Nearly 200,000 liters of 90 to 95 percent parahydrogen

were liquefied, and over a million liters of liquid nitrogen and 2,500

liters of liquid helium were produced. In addition, some 65,000 standard

cubic feet of pure hydrogen gas and about 200,000 cubic feet of pure

nitrogen gas were produced for both laboratory and off-site use. Cryogenic fluids were furnished to Bureau laboratories for applied research

and engineering development, to other government agencies and their contractors in the area, and to private companies and institutions. The general practice of recovering hydrogen gas evaporated during

storage, handling, and on-site use of the liquid netted almost three million

cubic feet of gas for re -use in liquefaction. This nearly equalled the

amount of electrolytic gas purchased, and made possible some of the

large runs that would otherwise have exceeded local available supply.

Gas recovery from off-site use will be considered if substantial increase

in requirements materialize. This practice also reduces operating costs, since in large production, the cost of the gas is a major item of liquefaction

cost. 2.14. Radio Propagation

The Central Radio Propagation Laboratory has primary responsibility

within the nation for collecting, analyzing, and disseminating radio

propagation data and information of value to such diversified fields as

air and sea navigation, frequency allocation, and worldwide communications. To carry out this responsibility, the Laboratory conducts research on the fundamental nature of radio waves, the basic theories of radio-wave

piopagation, and the characteristics of radio energy under widely varying

conditions. 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 in radio propagation includes both physics and

engineering studies. During the year, a considerable amount of work

was performed under the auspices of the International Geophysical

Year. Radio Propagation Physics

The radio propagation physics program is concerned with radio-wave

propagation over long distances by means of the ionized regions of the

earth's outer atmosphere. The program includes (1) basic research on

82
Radio propagation data are gathered at field stations throughout the world. Above, an NBS team observing low-frequency field intensities on the Arctic tundra near Thule, Greenland (page 82).

upper atmosphere physics, on the formation and disturbances of the ionosphere, and on the interaction of radio waves with the ionization; (2) study of the characteristics of specific propagation mechanisms such as ionospheric reflection, ionospheric scattering, and guided-mode propagation; and (3) regular public service as in the prediction of long-term

changes in useful frequencies for communication, in the warning of short- term disturbances to communication, and in the collection and distribu- tion of ionospheric and solar data on a national and international basis. Radio Waves from Lightning Discharges. Lightning flashes constitute a powerful and nearly constant source of radio waves over a wide

range of frequencies in the radio spectrum. Their complex, transient nature and their random occurrence have made it very difficult to study

them effectively with ordinary equipment. Under Air Force sponsorship, specially designed broadband equipment (1 to 200 kc), coupled to two crossed vertical loop antennas and a vertical monopole, was installed at Boulder, Colo., Salt Lake City, Utah, Palo Alto, Calif, and Maui,

Hawaii. These locations form a chain covering a distance of 3,200 miles. The equipment records the detailed waveform and polarization of t In- electromagnetic pulses from lightning flashes. Such records make possible

the calculation of radio wave attenuation values from the pulses as a function of radiofrequency and propagation distance.

Meteor Studies. Long distance radio communication is possible

by use of signals scattered from trails of ionization left by burning

meteors as they plunge into the upper atmosphere. The Bureau, for the Department of Defense, instituted a program to obtain statistics on

the variation of meteor burst signals by studying burst propagation over

three oblique test paths in the United States and Alaska. Digital

S3
recording techniques are being employed to amass the enormous quantity

of statistics required. Most of the instrumentation and preliminary

testing is completed.

Airglow Observations. In a program supported jointly by the

Bureau and the U. S. National Committee of the IGY, bi-refringent filter photometers, located on Fritz Peak in Colorado and in the Black Hills of South Dakota, scanned the night sky to detect emission at 5577 A

from oxygen atoms in the vicinity of the jE-region of the upper atmosphere.

These observations confirmed the fact that the 5577 A emission occurs from a height of 100 km and that the night sky contains large patches or

cells of airglow emission. For the first time these cells were mapped in

detail concerning their extent and movement. A typical airglow cell for 12 nights of study had a diameter of approximately 2,500 km, a diameter not far different from the great cyclonic motions in the troposphere. The

airglow cells appear to be moving through the upper atmosphere with a transitional velocity of about 100 m/sec and a rotational period of about

5 hours. The upper atmosphere appears to undergo very strong dynamic

motions of large cyclonic types.

Radio Propagation Engineering

The radio propagation engineering program is concerned with the more

efficient use of the radiofrequency spectrum. This objective can be at- tained only to the degree that the nature of radio -wave propagation and

the characteristics and the effects of radio noise and interference upon

various signals are understood both qualitatively and quantitatively.

The quantitative understanding of radio -wave propagation and the characteristics of radio noise requires the collection of statistical samples of

Chain of stations used in a study of the radio waves originating in lightning

flashes. Broadband receiving equipment is used to record the signals in a study of the attenuation of low- and very-low-frequency radio waves

(page 83). S4
data appropriate for the description of observed phenomena. It also re- quires the development of adequate methods for the prediction from these samples of the statistical characteristics of the various radio-wave propagation and noise variables required in engineering applications. The

work is directed toward a basic understanding of radio-wave propagation,

radio noise and signal-to-noise problems.

Radio Meteorology. During the past year a new Radio Meteorology

Section was established. Methods were developed for describing the

average refractivity of the atmosphere profile, from the surface upwards,

in terms of surface values which can easily be derived from measurements

regularly made at all weather stations. This model atmosphere will make possible the prediction of the diurnal, seasonal, and geographical

changes of these average refractivity profiles throughout the world. The

work led to a description of the bending of the radio waves in terms of

the model atmosphere, and to predicting the transmission loss in ground

wave, ionospheric wave, and tropospheric scatter propagation. By re- lating the surface value to a reduced-to-sea-level values, an improved

method was developed for predicting the surface value at any point in the world.

Tropospheric Forward Scatter. The formula for predicting the

transmission loss expected on tropospheric forward scatter circuits was

improved by using the new model radio refractivity atmosphere. More

accurate predictions are now possible at the lower frequencies (in the

range from 10 to 200 Mc), for very high or very low antennas, and for very large or very small values of the surface refractivity.

Ionospheric Propagation in the Range 10 to 1,000 kc. New theoretical methods for predicting ionospheric propagation in the range 10

to 1,000 kc were developed. These techniques allow for tropospheric

bending, a new approach to the space wave radiation from dipoles over a

spherical, finitely conducting earth, and focusing from a rough ionosphere.

Below 20 kc the formulas are based on the wave guide mode theory.

These formulas were used to predict an optimum frequency of the order

of 20 kc for a worldwide radio standard frequency broadcast system.

Radio Modulation Studies. Further progress was made in the de- velopment of methods for determining the information bearing capabilities of forward scatter circuits. In this connection, a method for the

spectrum analysis of the fading on such circuits was developed and tested. Measurement of Television Service Area. An improved method of

measurement that is expected to lead to a better estimate of the areas of

television service was proposed to replace the old method. In this method

sample measurements are taken at fixed locations around the transmitter.

These locations are established in a systematic manner so that all terrain types are equally likely and the data represent a random sample from the

area. In most cases the measurements consist of a single obsers a lion oi field strength except when time variations are involved. In these in- stances they represent a short recording of field strength from whieh the85
Equipment for measuring microwave energy transmitted through a parallelwire grid. The known properties of the grid provide a reference for use in studying radio attenuation in various materials (page 89).

distribution with time can be estimated. A sample set of observations

would be taken at a constant radius with sufficient separation to eliminate

serial correlation between successive observations. The distribution obtained can be used to estimate the percentage of locations at that distance

which receive service in the several grades. By joining together several such estimates made at different distances, an estimate can then be made

of the total area around the transmitter for each grade of service. International Geophysical Year During the year a considerable part of the Bureau's radio propagation

physics program was devoted to the International Geophysical Year—an

internationally coordinated program of worldwide synoptic geophysical

86
observations. These observations are particularly significant in understanding the interaction of radio waves with the ionosphere since such

phenomena as ionospheric disturbances, radio noise, solar flare effects, magnetic storms, and aurora and airglow activity are interrelated on a worldwide basis. IGY World Alerts. The special communications circuits for the

IGY observations, set up during the previous year, were put into formal

operation. The Bureau's radio forecasting center at Fort Belvoir, Va.,

is the communications center of the worldwide IGY program. This

World Warning Agency makes the final decisions designating the IGY

Alerts and Special World Intervals which are flashed in a few hours to IGY stations throughout the world. Thus the many experiments and

observations which must be timed with respect to activity on the sun can

be synchronized. Here are gathered from all over the world telegraphic

summary reports concerning solar flares, geomagnetic and ionospheric

conditions, and opinions of expected terrestrial consequences of solar

activity. The IGY warnings declared by the Fort Belvoir staff are sent out over the most extensive communication network ever established for

scientific purposes. During the year six significant terrestrial disturb- ances were successfully forecast and stations were alerted 26 times for unusual solar activity.

New Data on the Ionosphere. The ionospheric vertical sounding

program was considerably expanded in order to provide equipment for a number of new stations established in the western hemisphere, particularly in South America, and to implement a pioneering effort in ionospheric observations in Antarctica, where five stations were operated

directly by the United States and a sixth cooperatively with New Zealand.

New G-4 ionosondes were placed at most of these stations, or older equipment modified and modernized. Data from these stations were

collected at the IGY World Data Center A for the Airglow and the Ionosphere, located in the Boulder, Colo., Laboratories. Although analysis

of the data is still in process, results to date from the station at the

geographic South Pole show that an appreciable electron density persists in the F-region of the ionosphere during the prolonged absence of sunlight

in the Antarctic winter. Also, a significant diurnal variation of the

F-region ionization was observed during both the polar winter and summer; this result indicates some degree of terrestrial geomagnetic influence on the ionization.

Observations on Soviet Satellites. Immediately after receiving in- formation that a Soviet earth-satellite had been successfully launched on

4 October 1957, a program was initiated to set up radio interferometers

and observe transmissions at 20 and 40 Mc. These interferometers

remained in operation for the lifetime of the radio transmissions from

Sputniks alpha and beta, and many successful observations were made.

The data were reduced immediately for orbital information and passed on

to the Naval Research Laboratory. The data are being anal) zed Furthers7
to sort out such effects as the Faraday rotation of the plane of polarization

due to the nonisotropic properties of the ionosphere in the Earth's magnetic

field. Toward the end of the year, new permanent interferometers were set up to receive at 20 and 40 Mc to prepare for observations on

satellites transmitting on these frequencies in the future. Propagation Near the Magnetic Equator. Along the west coast

of South America, straddling the earth's geomagnetic equator, a network

of transmitting and receiving stations at 50 Mc in Chile, Peru, Ecuador,

Argentina, Brazil, and Panama was operated to study the special forms

of oblique incidence ionospheric scattering that occur in this region.

Discovered so far are a form of scattered signals correlating closely with

the vertical incidence echoes known as "spread-F," and a scattered signal

giving detailed information on the two closely related equatorial phenomena, the equatorial electrojet and the equatorial sporadic -E. The

equatorial electrojet is a strong concentrated ring of current surrounding

the earth in the ionosphere in the vicinity of the magnetic equator.

A new technique for studying the upper atmosphere evolved from satellite observations. Radio waves do not necessarily travel in a straight line to the

earth. Their path depends to a great extent upon the distribution of elec- trons in the ionosphere, and can be used as an indication of this distribution (page 87). 88
2.15. Radio Standards

The Bureau is endeavoring to adapt its program to the ever-growing

need for new and improved electronic measurement standards. This

program consists mainly of basic research and development on national

standards for fundamental electrical quantities, measurement techniques,

and properties of materials from audiofrequencies through the highest

attainable microwave frequencies. These activities include a calibration

service and radio broadcasts of the United States primary standard of frequency and time intervals. Attenuation. Developing of improved techniques and instrumentation for accurately measuring and standardizing attenuation at all required radiofrequencies was continued. Radiofrequency and micro- wave attenuators are used in signal generators, receivers, field-strength

meters, power meters, alinement of radar transmitters and receivers, and

many other applications. To insure the proper performance and ac- curacy of these instruments the top standardizing laboratories in industry,

military and other government agencies need transfer standards checked

against an adequate national standard.

Field-Strength. The planning, layout, construction, procurement,

installation, and performance testing of low- and high-frequency field- strength attenuation and linearity consoles for the Electronic Calibration

Center were essentially completed. Six crystal-controlled low-noise

receiver converters for 400 and 500 Mc were also completed for the Center. An experimental microwave antenna-gain measuring system was constructed, and an experimental microwave absorbing enclosure was constructed and its properties partially evaluated. Some waveguide horns were investigated for possible use as standards of horn gain.

National standardization in this field is very important in the growth

and control of all types of communications systems, including AM, FM,

and TV broadcasting. Increasing use of the microwave frequencies now

requires an extension of standards into that range. Frequency. Accurate frequency and time interval standards are of

recognized national importance to research, development, operation, and

manufacture by private and government organizations. The accuracy

requirements in frequency standards have increased by a factor of 10, or more, per decade for the last 30 years, and the national primary frequency

and time interval standard has continually been kept ahead by at least one order until now; recent trends in research and engineering indicate

that it will become more and more difficult to keep one order ahead of

commercially available frequency standards.

The Bureau's atomic frequency and time standards were improved

during the year. A second ammonia beam spectrometer (maser) was

put into operation. The relative stability of the two masers was shown

to be about 2 parts in 100 billion. With more careful thermal control and better voltage stability it is expected that a stability of I pari in 1 .000

89
Improved power standards installed during the year included this standard

calorimetric wattmeter (left) (page 91). Right: The second ammonia beam

spectrometer (maser) was put into operation as part of the Bureau's pro- gram to improve its atomic standards of time and frequency (page 89).

billion may be attained for a long period. A frequency comparison chain was constructed for comparing the frequency of the ammonia emission

with the cesium frequency standard.

The causes and possible reduction of short-time instabilities in oscil- lators and frequency multipliers were investigated. Two new oscillators at 5 and 10 Mc were developed, which showed a major improvement in

stability. Under the sponsorship of the Department of the Army, the

stability and aging rate of quartz crystals at low temperatures were

determined; measurements were made at 4° and at 77° K.

To operate quartz crystals at very low temperatures, a more precise

temperature-control device was developed in the form of a proportional

type electronic oven placed in a liquid nitrogen Dewar.

To measure more accurately the magnitude of short-time instabilities of oscillators and frequency multipliers, a new decade frequency multiplier was developed that makes possible a frequency comparison precision of

1 part in 100 billion or better in 1 second or less. Impedance. The development of national impedance standards has

become more important to the country's welfare as the manufacture of

radiofrequency impedance components has grown to be one of our major

industries. Accurate impedance measurements are also basic in the

measurement of attenuation, power, voltage, field-strength and other

quantities.

Measurements on a new 20 micromicrofarad variable standard capacitor

showed that its effective capacity can be calculated from its dimensions

to 300 Mc within 0.1 percent accuracy. A 2 /xjuf variable capacitor which

90
will act as a national reference standard to 300 Mc was also designed and

partially constructed. The NBS coaxial connector, recently adopted for use in all accurate impedance measurements up to 300 Mc, was modified

to permit quicker fastening and more accurate machining.

At microwave frequencies new techniques were developed for making more accurate impedance measurements. Two new type microwave

impedance standards (half-round obstacles in rectangular waveguides) were constructed; measurements of their performance agreed within 0.05 percent of the theoretical tabulated values. A method was devised to measure the reflection coefficient of short circuits. An ultra -stable klys- tron power supply was placed in operation and a system developed for water-cooling low-power klystrons, resulting in a stable high-gain micro- wave receiver. Noise and Interference. Noise, which includes any type of random

fluctuation, sets the ultimate limit to the successful detection or reception

of information. In many cases, such as in radio astronomy or in observations of high temperature plasmas, the actual derived information is itself of a noisy character, and must be compared with a standard of noise

power in order to take on quantitative meaning. Thus noise standards

are fundamental to developing and evaluating the performance of radio

and microwave devices, and are fundamental as a basis for making

numerous physical measurements.

Techniques for measuring the spectral intensity of both random and

impulse noise were investigated mathematically and experimentally in the frequency range from 50 kc to 50 Mc. Improvements were made in the sensitivity of an X-band comparison radiometer.

Under the sponsorship of the Navy Bureau of Ships, a program was

initiated to develop an improved standard method of measuring conducted

spurious power outputs of radio transmitters at frequencies from 14 kc

to 1,000 Mc and carrier power output levels to 1,000 watts. A study was made of the characteristics of a receiver to be used in measuring the

spurious output of the transmitters; the range of spurious harmonic output

levels of one type of transmitter was determined. From these two studies

the required interim characteristics of special filters to be used in the

measurements were determined.

Power. A set of national primary power standards for use up to 300

Mc was completed and is now in use. These include the 0- to 100-milli- watt thermistor bridge, the 1-milliwatt to 10-watt bolometer bridge, and

the 200-milliwatt to 20-watt dry, static calorimeter. The over-all accuracy of these standards is 0.5 percent which is marked improvement

over previous accuracy and ranges. A number of general purpose rf generators were constructed; all employed a special automatic rf level control. Two 10 db attenuator pads

capable of dissipating 100 watts of power were constructed to extend the

range of the power bridges and calorimeters.

Evaluation of a microwave microcalorimeter was completed an<l the
instrument placed in operation. It is used to determine the effective efficiency of bolometer mounts within an accuracy of 0.3 percent. A new

method of measuring bolometer mount efficiency, based on the impedance

technique, was devised to provide improved accuracy and simplified

operation.

Voltage and Current. Consoles for calibrating ra iiofrequency volt- meters were completed, tested, and placed in service in the Electronic

Calibration Center. They cover eight frequencies from 30 kc to 100 Mc.

Construction on a console for higher frequencies is in progress. An experimental study of the behavior of conical condensers showed

that their wide range of capacity agreed with theoretical predictions.

Comparative maps of a two-dimensional field and, for the first time, of an axial-symmetry field for the conical case were constructed to verify

certain theoretical work.

Development continued on the new type attenuator-thermoelement

(AT) voltmeters. A new balanced two-thermistor mount was designed

and constructed. This was used to compare balanced rf micropotentiometers with the single thermistor bridge while sources of error were

studied in the balanced devices.

A 60 ampere, 1 Mc source was constructed for a special calibration

service.

Model of millimeter-wave interferometer being used to investigate applications to the measurement of the velocity of light, to metrology, and to di- electrometry (page 94). 92
Dielectric Measurements. Various improvements, added to the

automatic cavity used for dielectric measurements, included a latching

system, meter circuit, and a memory drum. All helped reduce operator

time.

At microwave frequencies the theory and practice of making dielectric measurements in a special resonator were improved. Loss tangents as low as 5 x 10-5 can be measured by this method. The theory was extended

to include a magnetic as well as a dielectric constant, and experimental

evaluations of errors were made. Improvement was also made on a method of microwave dielectric measurement using a special resonator with a centered sample rod. This method was successfully used to measure the dielectric properties of ceramics up to a temperature of 500° C.

It also provides good sensitivity in measuring low losses. A theoretical analysis of the loss measuring capabilities of sealed cavity

resonators for compressed gas dielectric measurements was completed.

Magnetic Materials. A ballistic galvanometer was set in operation

for obtaining static hysteresis loops. A dielectric sample holder was

adopted for determining dimensional resonance phenomena in ferrites. The frequency range of the reversible permeability permeameter was

increased. Construction was completed on two instruments for complex permeability measurements; one was a variable length cavity for the 300 to 6,000 Mc range and the second, a coaxial variable length

transmission line for the 1 to 50 Mc range. Under the sponsorship of

the Navy Bureau of Ships, studies were made of the tensor permeability

of ferrites. Conductivity of Materials. Preliminary investigations were made

on the Hall effect at radiofrequencies and on cyclotron resonance in semiconductors. Equipment was installed and microwave resonant cavities were constructed for the purpose of studying the gyrotropic effects experimentally

Work in this field was undertaken to make fundamental studies of the

complex conductivity and related phenomena of conducting and semiconducting materials at high frequencies. The studies include investigation of conduction gyrotropic phenomena at radiofrequencies and of the

plasma behavior of fluid and solid materials.

Microwave Spectroscopy of Gases. The analysis of the microwave

spectral data for gases and beams was virtually completed.

To provide better mathematical procedures for use in the Bureau, new methods for numerical integration and for obtaining interpolation

functions from computations or measurements at optimally spaced points were developed. These methods often reduce computation by a large factor and may reduce calibration and other measurement time by a

third. In addition to providing a compendium of precise spectroscopic and

molecular data useful in many branches of science and industry, the micro- wave spectral tables will provide reference and working frequency

93
standards. Analysis of the dielectric constant and adsorption data

permits reliable estimates of such data for pressures, temperatures, and

even materials for which such data are unavailable.

Millimeter Wave Research. A microwave interferometer and asso- ciated instrumentation to operate at a wavelength of 6 mm was developed

for application to velocity of light measurements, to metrology, and to dielectrometry. Electromagnetic horn radiators with matched dielectric

lenses, having stable radiating apertures of dimensions 60 and 30 cm

square, were constructed. Radiation pattern measurements showed that

these horns give well collimated beams in agreement with theory. Calculations showed that the diffraction correction would be around 2 parts

in 105 for the aperture sizes and field distributions envisaged.

Excellent fringes were obtained in an experimental model of the

Michelson interferometer, and the advantages of inserting attenuation

in the free space arm to eliminate multiple reflections were demonstrated.

Some work on the design of a millimeter-wave Fabry-Perot interferometer was completed, with particular reference to the problem of reflector design. A pilot model of this interferometer is under construction.

A higher mode cavity was developed for measuring the refractive index

of gases at 6 mm. Also a Pound IF system of frequency stabilization was made and a klystron, operating at frequencies around 50,000 Mc,

was locked to a cavity resonator for long periods. 2.16. Basic Instrumentation

Research and development in basic instrumentation during the past

year was carried on under the support of the Office of Naval Research,

the Atomic Energy Commission, and the Office of Scientific Research of

the Air Research and Development Command. The principal emphasis,

throughout the program, was on the fundamentals of measurement and

control, and on the development of the science of instrumentation.

Preference was shown to those research projects that seemed likely to have

broad utility in measurement or in extending significantly the range, reli- ability, or sensitivity of some general class of instruments. Also given

primary consideration were theoretical and experimental studies of problems common to many instruments—drift, lag, and unsteadiness, for example—or of the limits of performance inherent in various types of

instruments. Besides the basic research and development in instrumentation, major work during the past year included the operation of an

instrumentation reference service and the research and development of information retrieval systems.

Instrumentation Reference Service. References to instrumentation literature were selected, analyzed, coded, and recorded by punching

into the special punched -card index system. One set of punched cards

constituting an index of 18,000 instrumentation references was completed

and was placed in routine use for information retrieval in providing consultation service. Indexing work continued on the second set of index

94
cards. The card system and other sources of information were used in answering a large number of inquiries from the Bureau and from other

government agencies and their contractors. Various areas of instrumentation were surveyed including thickness

measurements, measurements of free -air temperature and aircraft true airspeed and groundspeed, and recording methods.

Information Retrieval Systems. Development of methods for replicating the index card set referred to above was undertaken to permit

distribution of the collection on an experimental basis. A number of

techniques are feasible. A printing technique appears most promising

and is being actively pursued. Design of electromechanical devices to

increase efficiency and speed of information retrieval with the special

card system reached an advanced stage and construction was started. Great interest has been shown by other government agencies, by private

industry, and by other institutions in the information retrieval developments thus far achieved. A large number of requests for information

have been answered, consultations on information problems have been

provided, and working drawings of devices thus far developed have been

made available to potential manufacturers and users. Basic Instrumentation Research. Research has included investi- gation of linearization of capacitive -probe measurement of displacements,

investigation of photoconductive devices, development of simple and

reliable methods for counting holes in punched cards, investigation of

limitations in microphotographic copying and reading, and development

of automatic data -processing techniques.

3. Calibration, Testing, and Standard Samples

Rapid developments in both civilian and military technology, and

particularly in the missiles and satellite programs have brought an unprecedented demand for new and more accurate standards of measure- ment. This demand has led to the establishment by the military agencies and their contractors of rather elaborate systems of laboratories.

The national standards of measurement at NBS may be considered as occupying a position at the apex of a giant pyramid. Successive echelons

of reference and working standards serve to relate the national standards

to the measuring instruments required for the successful operation of the

extremely complex equipment at the launching pads or on planes, shipboard, or in fortifications. This rapidly increasing demand for standards has been reflected in all fields of calibration, particularly in electrical instruments. During the

year over 4,000 electrical and magnetic standards were calibrated, involving over 25,000 determinations, an increase of 50 percent over the pre- ceding year. This reflects both the tendency to use electrical methods

and instruments to measure non-electrical quantities and also the estab- lishment throughout the Nation of an ever-increasing number of electrical standardizing laboratories. 95
Nomenclature of Standards

A uniform nomenclature for standards of measurement has assumed

increased importance because of the growing use of standards in modern

technological development. To meet this need a nomenclature has been

developed as a substitute for the loose and imprecise terminology now in use.Standards are classified into categories under this system, the first category being the prototype category which includes the arbitrary and

independent standards of length, mass, time, and temperature on which

our measuring practices are based. The other standards, denned in terms of the prototypes, are classified in derived, calibration, and instru- ment categories. A fifth category, called standard materials, includes

pure chemicals and other materials which are not defined in terms of

standards of the prototype category. The items which the Bureau has

been supplying under the standard sample program fall into the categories of calibration standards or standard materials.

Within each category the standards are ranked as national standards,

national reference standards, and national working standards. It is suggested that standardizing laboratories cooperating with the Bureau

rank their standards within each category as laboratory reference standards and laboratory working standards.

New Calibration Facilities and Equipment

To meet the ever increasing needs of science, industry, and the Government, the Bureau is constantly developing new calibration facilities which contribute to higher accuracy and new and improved standards.

These range from small items of laboratory equipment to installations the

size of the new Calibration Center at Boulder, Colo.

Electronic Calibration Center. Construction of equipment for the

Center formed a major part of the year's activities. Instrumentation for d-c and low-frequency calibrations was almost completed, and about

half of the planned instrumentation for high frequency and microwave

calibrations. Reports of this work are included under appropriate

subject headings in section 2.15 (page 89). The rate of completion was

limited by the availability of funds and trained personnel and in some

cases by the lack of primary standards upon which to base a calibration

service. Numerous types of standards were calibrated for industry and

all branches of the armed services during the latter half of the fiscal year. Calibrations performed in the low-frequency region fall into six general

categories: Resistors and resistance apparatus, inductors and capacitors,

standard cells, indicating instruments, potential and current transformers,

and miscellaneous, including ratio devices. In the high-frequency region,

equipment is being installed to calibrate voltage, power, attenuation,

field strength, and impedance standards. In the microwave region

(above 300 Mc), facilities for the measurement of power, impedance,

attenuation, and frequency are being constructed.

90
As the facilities described above were completed and put into service,

the Center handled an increasing volume of the calibration services. The

need for the low-frequency calibration service offered by the Center was amply confirmed by the extent to which this service was utilized. In

addition to the services provided to the Armed Forces (the original re- quest that the low frequency service be offered in Boulder was made by

the Air Force), numerous calibrations were made for industrial organizations located in the West.

Standard Radio Broadcasts. The national primary standard of

frequency and time interval is maintained at the NBS Boulder Laboratories. A commercial atomic frequency standard along with data from

the NBS cesium resonator made it possible to commence in December

1957 regular determination and publication of ¥WV corrections in terms of the NBS atomic frequency standard.

As a step in the further improvement of the stability and precision of

the broadcasts from ¥WV and WWVH, two new commercial oscillators were procured and one placed at each station. Tests indicated that the

stability of the one at WWV was 2 to 3 times better than that of the best

oscillator previously in use. The experimental standard frequency broadcast (KK2XEI located at Boulder, Colo.) at 60 kc, begun in 1956, was continued during the year. This provided a standard frequency, at receiving points in the United

States, which in 1 to 3 hours' measuring time is 1 or 2 orders better than

that provided by WWV. However, the low radiated power on 60 kc (20

to 40 watts) was a deterrent to its wide use because of the difficulties in reception at distant points. Because many research organizations need

the higher accuracies afforded in 60 kc, considerable planning work was

done toward establishing a high power, standard frequency broadcast

station near Boulder in band 4 (3 to 30 kc) which will provide high quality

signals in the United States and over the rest of the world.

The addition of equipment to broadcast special signals for IGY was made at WWV and WWVH during the year. This service was added

because the NBS stations are well known and extensively used throughout

the world.

The radio -broadcast technical services are widely used by scientific,

industrial, and governmental agencies and laboratories as well as by

many airlines, steamship companies, the armed services, missile research

laboratories and contractors, IGY personnel, satellite tracking stations,

schools and universities, numerous individuals, and many foreign countries. They are of importance to all types of radio broadcasting activities such as communications, television, radar, air a ad ground navigation

systems, guided missiles, antimissile missiles, and ballistic missiles. Standard Capacitors. The accuracy needed by industry in the cali- bration of standard capacitors has recently been increasing so rapidly that

the Bureau has at times been unable to meet this need. Recently the design and construction of an experimental bridge was completed, pro- 97
viding greatly increased accuracy of capacitance measurements. A bridge

of this type will soon be built for use in the calibration of capacitance

standards.

Automation of End Standard Calibration. Master end standards, or gage blocks, are calibrated by the Bureau for other government

agencies and for industrial and scientific laboratories. By this means the

Bureau extends its length standards throughout the country and makes

it possible for industry to produce, in different factories, precision parts

which are interchangeable.

During the past fiscal year the Bureau calibrated over 4,500 end standards. This large workload has made it profitable to investigate the applications of semi-automatic methods of calibration. A large portion of

these calibrations are made by mechanical comparison with master end

standards rather than by measurement by the use of lightwaves. For the

calibration by comparison procedure the observer records the original

observations on punched cards. After this has been done, automatic

programed computing equipment applies all corrections and ultimately

types out the report. This not only accelerates the work but it eliminates

many sources of error and much tedious checking.

Periodically the original punched cards prepared by the observer are subjected to a different program by the computing machine which tests the consistency of the results obtained by the comparison of a given gage

submitted for test with the different Bureau master gages. This affords

a check on the correctness of the calibrations of the Bureau gages with a minimum of additional work. An extension of a similar method to the

gages that are measured directly in terms of lightwaves is planned.

Dead-Weight Testing Machine. The Bureau is designing a 300,000-

lb. dead-weight machine which will serve to provide high precision cali- bration service for many current industrial and military requirements.

Modern missile and rockets systems depend on the development of thrusts

in excess of those which can now be measured directly against standards

calibrated in existing dead-weight machines. An accurate determination

of the rocket thrust and also of the missile load is extremely critical at the

early launching stages of a missile flight.

Based on its design experience with the 300,000-lb machine, the Bureau

plans to design and construct a 1,000,000-lb dead-weight machine which

will meet some of the very special and urgent calibration requirements now

in existence and those expected to develop in the near future. Since 1927 the Bureau has provided a calibration service for force measurement devices which are used for such varied purposes as weighing

the contents of tanks, bins and hoppers, measuring the thrust forces of jet

and rocket engines, and serving as load-sensitive devices in the automatic

control of machinery. A dead-weight machine of 120,000-lb capacity was

installed in 1927 and was augmented in 1931 by nine 1,000-lb weights, in- creasing its capacity to 111,000 lbs and providing test loads by 1,000-lb

increments instead of 10,000-lb increments.

98
Calibration Services

The Bureau's calibration services are a natural outgrowth of its custody

of the national standards of physical measurement. Through these

services, the national standards are extended, with the required degree of accuracy, throughout commerce, industry, and the military establish- ments. The growing demand for calibration services indicates the importance to science of precise measurement, the dependence of industry

upon accurate calibration services, and the increasing complexity of our

technology, in which measurement plays a more vital role every year. Recognizing the importance of this problem to modern aircraft and

missile reliability, the Defense agencies have individually initiated pro- grams for the careful and continuous monitoring of all their instruments

which control the reliability of the components in their weapons systems.

Collectively they have asked the Bureau to provide an up-to-date and

continuing calibration service for their individual standard control instru- ments. These priority calibrations have necessitated an augmentation

of the Bureau staff in these areas. In the calibration of force-measuring

devices in connection with the missile program, the workload in some

instances has required a two-shift operation.

In such diverse areas as electronics, optics, acoustics, thermodynamics,

and atomic and radiation physics, the volume of calibrations performed

by the Bureau, in number of items, and in dollar value, showed a considerable rise over the previous year (table 1). Dynamometers, load

cells and transducers, aircraft weighing kits, proving rings, Amsler

boxes, vibration pickups, and hardness test blocks were among the

many items calibrated.

Most large scale weighing is done on railway track scales. The

Bureau calibrates these scales through the use of 80,000 lbs. of highly

accurate weights carried in each of two test cars. Seventeen of the

eighteen master scales of the country were calibrated, and 148 commercial

type railway scales were tested. On the Bureau master scale 39 railway

scale test cars were standardized and 3 such cars, which could not be

moved to a master scale, were standardized in the field by comparison

with NBS standards. Two hundred sixty- two large test weights, some

of which were destined for missiles projects, totaling some 203,000 lbs., were tested and adjusted to nominal values. Services Discontinued. The calibration of viscometers by the

Bureau was discontinued effective January 1, 1958. This service has

been requested very rarely during the past several years, and the instruments in question can be calibrated by the users with the NBS or American

Petroleum Institute viscosity standards. Calibration by the user is just as accurate as are his determinations of unknowns, and offers the

advantage that certain systematic errors might tend to cancel out if both the calibrating liquid and the unknown are used by the same operator

under the same conditions. All those who requested this service during

the previous 4 years were contacted before this service was discontinued,

and no substantial objection was encountered.

99
100
Testing Services

While the calibration services of the Bureau are rendered for all who

require them in Government and public alike, the testing services are

available only to other Federal agencies except when the Bureau has

facilities not available elsewhere or when it is called upon to act as a

referee. Testing in quantity is restricted to a few items—notably lamps and

cement; with these the Bureau's tests control a large part of the procure- ment for the Federal Government, and as indicated in table 2 they repre- sent the largest dollar volume of test fees. The samples of lamps in- spected represented over 4,500,000 individual lamps, of which 5 percent were rejected on initial inspection at the factories and about 1 percent more on subsequent life test at the Bureau. The cement inspected and

tested represented 13,686,361 barrels, for major Federal construction

projects.

Other tests included a great number and diversity of items under government procurement ranging from conveyor belting to ball-point pens, from feathers and down to road building materials. These tests were made in the main for other Federal agencies that either lacked laboratory

facilities or else required facilities available only at the Bureau.

In connection with the maintenance of the List of Certified Dental

Materials of the American Dental Association, Research Associates sup- ported by the ADA tested a total of 131 items of dental materials for compliance with ADA specifications. The materials tested included

amalgam alloys, dental mercuries, zinc phosphate cements, silicate cements, and agar type hydro-colloidal impression material. Five items

had not been previously certified. The association, through the Journal

of the American Dental Association, made available to practicing dentists a certified list of 317 items of dental materials.

Standard Samples

Thirty-eight new standard samples were developed during the year, bringing the total number of samples available to science and industry

to well over 600. Approximately 55,523 standard samples, having a fee value of $241,554, were issued by the Bureau. A summary of the standard

samples program by area of activity is given in the accompanying table. Fourteen samples of phosphors were made available as standard

samples for the first time. These were selected in cooperation with

representatives of the industry, users, the Electrochemical Society, and

NBS for industrial and research use in controlling the quality of phosphors

and the development of improved phosphors for radar screens, television

sets, and radioactivity counters and detectors. The main concern in the

development of the samples was to provide material with uniform characteristics to serve as a basis of comparison with other phosphors.

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The second year of a 3 -year program for the production of spectrometric

standard samples has been completed. Sixteen new spectrographic

standards (8 compositions in two sizes) of ingot iron and low alloy steel were issued with provisional certificates of analysis covering 17 elements.

This is the first set of standards designed especially to provide calibra- tion for all of the elements encountered in the analysis of iron and steel, including carbon, phosphorus, the common metals, and several unusual

elements such as zirconium, tantalum, germanium, and titanium. Work

continued on the preparation, testing, and analysis of 27 standards of

high-temperature alloys, 27 titanium alloys, 6 zirconium-base alloys, 2 copper-base alloys, and 1 nickel oxide.

Also, six new standard samples of certified composition were prepared:

3 lithium ores, 2 alumina refractories, and 1 titanium alloy. Twelve

renewals of exhausted standards were also prepared. These included 4

steels, 1 iron, 1 nickel-base alloy, 2 copper-base alloys, 3 chemicals, and

1 melting-point aluminum.

Two new samples, one of which is the first natural rubber sample issued

as a standard were added to the list of standard samples of rubber compounding ingredients during the year, making a total of 17 samples.

Two of the existing samples were exhausted and replenished during the

year. The sample of natural rubber is the culmination of approximately 8

vears of effort in cooperation with technical committees, rubber growers, and manufacturers. When studies to improve natural rubber testing were resumed at the Bureau in 1948, it was recognized that a standard

sample was needed as a yardstick for standardization of testing in rubber

laboratories throughout the world. The new natural rubber sample fills this requirement.

Inter- Laboratory Reference Sample Program

Tests of properties of materials are usually somewhat empirical in nature. The results obtained are therefore particularly sensitive to the

condition of test equipment and deviations from prescribed laboratory

procedures In an attempt to assist testing laboratories in identifying

factors which may adversely affect their results, the use of a standard ref- erence sample program is being explored. It is thought that standard

reference samples regularly distributed to testing laboratories may enable

each to measure its performance against those obtained by the balance of

the industry, and to judge when equipment or procedures require repair or modification. Also, data from such a program are useful in the deter- mination of methods which require refinement to make greater reproducibility possible.

Portland cement testing has been chosen as an area in which the benefits of such a reference sample program can be evaluated. Pairs of samples

are sent bi-monthly to 103 laboratories which have indicated an interest

in such a program. Data are distributed to the participants in a graphi104
cal form which, without involved statistical procedures, permits evaluation

of the test method and evaluation of an individual laboratory. More

formal statistical analysis involving extensive computation is also being

conducted. There is already evidence, after only two pairs of samples,

that some improvement has resulted in laboratory performance. In addition to the portland cement program, assistance in the maintenance and improvement of standardized testing for government laboratories was provided through the paint reference sample program. Seventeen laboratories participated in the examination of two samples. Nine

different properties were evaluable for each point. The examination of the data revealed that some of the best procedures should be reviewed

and more carefully specified. Apparently some of the procedures are vulnerable to individual interpretation causing a lack of accordance

among the results from the 17 laboratories.

4. Cooperative Activities

Throughout its long history, the Bureau has carried on extensive co- operative and consultative activities with other agencies of government

on local, state, and Federal levels, as well as with broad segments of the

nation's scientific, industrial, and commercial communities. The in- creasing importance of international trade, and the dependence of tech- nological progress upon the exchange of scientific data among the nations

of the world have tended to extend this cooperation into the international

sphere.

The activities range from research projects on the properties of materials

to the development of nationally and internationally recognized standards

and practices. In general, the relationship between the Bureau and the cooperating

organization follows this pattern: the Bureau contributes by providing

methods of testing, data on properties of materials, and standards of

measurement; the sponsoring society or agency provides other technical

data and promulgates the finished documents in the form of codes or

specifications.

Some indication of the trend toward the coordination of standardization

work among all interested national organizations and laboratories is the

increasing amount of foreign travel by members of the Bureau staff. About 70 members of the Bureau staff went to Europe to participate on

behalf of the United States in technical meetings of the International

Organization for Standards and the various other international scientific commissions and unions.

One of the more important meetings in the western hemisphere oc- curred at Rio de Janeiro, Brazil, September 1957. The Associate Director

for Engineering served as Chairman of the United States Delegation to the

Inter-American Meeting of Experts on Standards of the Inter-American

Economic and Social Council, Organization of American States. 105
At the request of the Australian Government, the Bureau's

Director served on a committee to study the programs and organization

of the Australian National Standards Laboratory. He spent the months

of October and November 1957, in completing this assignment. Recommendations for the long-range strengthening of Australian standards

activities were made and are now being implemented.

Specifications and Test Methods for Government and Industry

At the request of the General Services Administration the Bureau is responsible for the preparation and maintenance of Federal Purchase

Specifications covering a wide range of materials and products. In addition, the Bureau reviews hundreds of proposed specifications both for GSA and other agencies to determine their suitability for use by the

Federal Government.

The^development of test methods is one of the statutory functions of

the Bureau. For Federal Specifications, the Bureau attempts to develop

methods that will be applicable to groups or classes of products or materials rather than methods covering a single item. To eliminate unnecessary or undesirable variation, general methods for similar products have

been grouped together and made available in the form of test method

standards. Suitable and uniform tests for a product are assured in a product specification by making appropriate reference to these standards.

The Bureau is in a position to make an important contribution in this entire area by its active participation in the work of technical societies,

industrial organizations, and standardization groups. Thus, Federal

Purchase Specifications can be coordinated with those of industry, and

full advantage can be taken of new developments and improved manufacturing processes. Coordination does not necessarily make Federal

Specifications identical with those of industry because purchasing

methods of the Government differ markedly from those of industry.

The Bureau accepted assignment for 106 commodity specifications, 30

material specifications, and 8 test method standards in the field of

organic and fibrous materials alone. The development and revision of

methods of test for various properties of these materials was carried

forward. Also, assistance was given to government users of linoleum

floor covering, who were engaged in developing standard methods for measuring specular reflectance for these products.

The Bureau has long worked closely with the American Society for Testing Materials. In the past year cooperation was given ASTM

Committees in the publication of Method of Color Specification by the

Munsell System, in the evaluation of the haze and color properties of

clear and diffusing plastic materials, and in the development of a pro- posed standard method for the measurement of turbidity of industrial waters. Also for ASTM Committees, the Bureau worked on such varied

projects as a test method to determine the resistance of plastic to scratch- 106
International agreement on the standards of physical measurement is re- ceiving increased emphasis. Above, preparations are made for the inter- comparison of the Japanese and American standards of microwave power at the NBS Boulder Laboratories (page 108). ing, a proposed revision of the method for determining the resistance

of rubber to abrasion, the revision of their Tentative Method of Test

for Tensile Properties of Plastics, a specification for glass fabric reinforced

resin laminates, and the preparation of official abbreviations for long

chemical names for various types of plastics. Also, one of the staff members served as chairman of a task group of ASTM to write a test method for determining the weight of coating on aluminum-coated sheet

and wire.

Another scientific society with which the Bureau has had close association is the American Standards Association. Last year, an NBS

Handbook, "Safe Design and Use of Industrial Beta-Ray Sources," was

prepared under the sponsorship of the Bureau by the Subcommittee on

Sealed Beta -Ray Sources of American Standards Association Z54 Sectional Committee, whose purpose is to formulate safety codes in which

basic standards and other appropriate data are applied to industrial

radiation protection problems. In addition, the Bureau sponsored or cosponsored 13 other ASA projects.

Standards research was also done in cooperation with organizations

such as the American Chemical Society, the Electrochemical Society,

the Optical Society of America, the EIA Joint Electron Tube Engineering

Council, the Society of the Plastics Industry, the Inter-Society Color

Council, and the Signal Section Committee of the Association of American

Railroads.

489867—59 8
International Activities

The Bureau contributes to the establishment of internationally recog- nized standards and practices through cooperation with international

standardization and professional groups. Prominent among these groups

is the International Organization for Standardization. A staff member

served as Chairman of the Seventh Meeting of ISO/TC/61 on Plastics held

in Burgenstock, Switzerland, and a member also was leader of the U. S. Delegation to the meeting of ISO/TC/45 on rubber held in Zurich, Switzerland. The Advisory Committee on Thermometry held three sessions at the

International Bureau of Weights and Measures at Sevres, near Paris, France. Two members of NBS were sent to attend and to visit laboratories in Europe in preparation for these sessions. To ascertain the degree of reliability of thermal methods for the assay

of chemical purity, the International Union of Pure and Applied Chemistry requested at its Paris meeting in 1957 that the Bureau undertake a comparative study of results obtained in the many laboratories that employ this method of assay. This is the first time that a thorough comparison of the results obtained in different laboratories by this important

method has been made.

The 12th meeting of the International Commission for Uniform Methods of Sugar Analysis was held at the Bureau in June. Approximately

98 delegates and observers from 20 countries were in attendance.

Meeting in the United States for the first time since 1927, the Inter- national Scientific Radio Union (URSI) held its 12th general assembly in Boulder, Colo., from August 22 through September 5. More than 500

delegates from 26 countries responded to the invitation of the U. S. A. National Committee of URSI and the National Academy of Sciences.

Field test of the dimensional stability of brick walls constructed with mortars

containing various dolomitic limes. The results are being correlated with

those of a laboratory autoclave expansion test of the lime constituent to de- termine the suitability of the autoclave test for masonry lime specifications.

This program is carried on in cooperation with the National Lime Association,

(page 110). 108
The scientists met to exchange technical information, coordinate inter- national research efforts, and recommend future projects. The inter- national intercomparison of microwave power standards recommended

by Commission I of URSI, was inaugurated by comparing a bolometer

mount provided by Japan with the Bureau's standard.

Five members of the staff participated in the following capacities in the

work of the International Commission on Illumination: Secretary of U. S. National Committee, Chairman of International Working Committee

on Colorimetry, Chairman of Papers Committee and of U. S. Committee

on Photopic and Scotopic Vision, Chairman of U. S. Committee on Colors

of Signal Lights, and Chairman of U. S. Committee on Aviation Ground

Lighting.

The Bureau cooperated with the International Association of Testing

and Research Laboratories for Materials and Structures in compiling and

reviewing technical information on materials for prestressed reinforced concrete structures. For more than three decades NBS has provided major support for both

national and international groups concerned with radiation protection.

It serves as sponsor for, and currently holds the chairmanship of, both

the National Committee on Radiation Protection and Measurements

(NCRP) and the ASA Z54 Committee on Industrial Uses of Radiation.

The Bureau continued its training services to the International Cooperation Administration, the United Nations, and other federally recog- nized organizations interested in its research and testing programs. Ar- rangements were completed for a number of individual trainees, guest

workers and research fellows to work in NBS laboratories.

Teams of specialists have come from several nations. Among these were specialists in refrigeration, textiles, purchasing, industrial technology,

physical measurement, and education. Conferences and visits to our re- search laboratories were followed by question and discussion sessions. These were profitable to the teams as well as to the Bureau experts. In one outstanding example, trainees from the Central Glass and

Ceramic Research Institute, Calcutta, India, successfully produced optical glass at that Institute upon their return. The Minister of Scientific and Cultural Affairs described this as the Institute's "crowning achievement", and the Director of the Institute expressed his thanks to the

Bureau for the assistance and information given the trainees, which en- abled them to design, fabricate, and successfully operate the plant.

Other international organizations in which the Bureau participated

include the International Union for Theoretical and Applied Mechanics,

the International Institute of Refrigeration, the International Council

for Building Research Studies and Documentation, and the European

Productivity Agency.

109
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, 10 groups are supporting research

associates at NBS in the following areas:

Sponsor Field of Activity

American Dental Association Dental research and testing. American Electroplaters Society Research on electroplated coatings.

American Society for Testing Materials Cement reference laboratory.

Asphalt Roofing Industry Bureau Asphalt roofing research. Bone Char Research, Inc Research on adsorbents for sugar

refining. Calcium Chloride Association Hydration of portland cement.

National Research Council Masonry research. Porcelain Enamel Institute Test methods for porcelain enamels. Portland Cement Association Cement research. Joint Committee of Chemical Analysis by Standard X-ray diffraction powder

X-ray Diffraction Methods. (ASTM & Am. patterns. Crystallographic Assoc.). 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 fur- thering 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 31

organizations as follows: Donor Field of Activity

American Dental Trade Association Standards for color of dental equip- ment. American Iron and Steel Institute Standard samples of ferrous metals,

steel research. American Iron and Steel Institute Bond tests on high yield point rein- forcing bars. American Petroleum Institute Metal-organic analytical standards. Brown and Sharpe Manufacturing Company. . Precision Gage Block Program.

CBS Television Television Field Strength Studies. Corrosion Research Council of the Engineering Reactions at Metal Surfaces and

Foundation. Stress Corrosion. Dearborn Gage Company Precision Gage Block Program.

Do-All Company Precision Gage Block Program.

E. I. du Pont de Nemours & Company, Inc . . . Precision Gage Block Program.

Edward Orton Ceramic Foundation Research in clays. 110
Donor Field of Activity

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.

International Nickel Company Effect of Nickel on Thermal Conductivity of Steel. International Nickel Company Revision of "Nickel and its Alloys."

Link Aviation, Inc Precision Gage Block Program.

National Lime Association Hydration of Lime.

New Departure, GMC Precision Gage Block Program.

Owens-Corning Fiberglas Corp Design Values for Reinforced Plastics 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.

Timken Roller Bearing Company . Precision Gage Block Program.

UNESCO Ionization Chamber.

The Van Keuren Company Precision Gage Block Program.

Welding Research Council Stress-corrosion cracking of stainless

steel. Anonymous Ether peroxides.

Anonymous Phenomena of crystallization.

Free Radicals Research. Close cooperation between the Bureau and

industry also is maintained in the three-year program of basic research on the properties of solids containing trapped free radicals which was

undertaken for the Department of Defense in October 1956. During the

past year considerable progress was made in unraveling the problems

connected with this field. The program which is being carried out in various sections of the Bureau represents a coordinated effort by scientists from Government, industrial, and university laboratories to determine

the properties of a new class of materials in as short a time as possible.

During the past year approximately 30 senior investigators were

actively engaged in the program. Of this group approximately half are

scientists on loan from industrial laboratories. Others are on leave from

or associated with universities. These scientists are applying a wide

variety of physical and chemical techniques, both experimental and

theoretical, in an effort to determine the properties of the solids which

contain appreciable quantities of trapped reactive species. One way of

classifying the many diverse activities in progress is in terms of three

broad categories of activity. The first category involves a considerable

effort on methods of production of radicals for stabilization. The second

category, which represents the largest effort, is that devoted to the characterization of the solids containing trapped radicals, and the third

category consists of experiments in progress designed to develop information concerning the use of radicals, or of solids containing radicals, in chemical processes.

Ill
Weights and Measures

The Bureau's Office of Weights and Measures carries on a broad pro- gram of cooperation with officers of the States, Commonwealths, and Territories of the United States, who are responsible for the regulatory control of commercial weighing and measuring devices and practices within

their jurisdictions. The range of these services is extensive, including

consultation on model weights and measures statutes, rules, and regulations, the design of accurate physical standards of length, mass, and

capacity, effective procedures for testing commercial weighing and measuring devices, specially designed testing equipment, plans for systematic

and effective quantity checking of prepackaged merchandise, administrative procedures, specifications and tolerances for commercial devices,

training schools for weights and measures officers, and visual aids for technical training.

During the year a field study on methods of commercial filling of con- sumer storage tanks for liquefied petroleum gas was completed, and the

results were made available to the weights and measures officials and to the

industry through the National Conference on Weights and Measures.

Testing equipment, based on a prototype prover developed by the Bureau,

is now available commercially for proving the accuracy of LP gas meters. This equipment is being placed in service by industry and by the States

for accuracy control. Although weights and measures officials have for years checked pre- packaged commodities for accuracy of the quantity declarations required on such packages, the procedures for these operations have been nonuniform, and in many cases theoretically unsound. A thorough study was made during the year to develop a standard procedure that could be

recommended to weights and measures officials. This study was dis- tributed for comment, as a proposed procedure.

Under a continuing project of reconditioning, when necessary, State standards submitted to the Bureau for reverification, a number of mass

and volumetric standards have been put into acceptable condition and

certified. During the year the motion picture "Assignment—Weights and Measures" was released. Presented by the National Conference on Weights

and Measures through the cooperation of the Bureau, the film tells the

story of how weights and measures supervision affects the average American family. A total of 16 prints were purchased by officials and schools,

and 83 loans were made. Over 82 loans of the other two weights and measures films, "A True Standard" and "Testing Mass Standards by

Substitution," were made to schools, civic organizations, service clubs,

businesses, industries, and scientific and technical societies. During the year the assembly of books, public documents, and other

publications was begun, which will eventually be a completely indexed

weights and measures archival and reference library for the NBS staff as well as for students and researchers in this field. 112
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 are more accurate, more constant, and more durable. In 1836 and in 1866, the Congress pro- vided the States with reference standards that became the basis for na- tionwide uniformity. Since then, through obsolescence and some indi- vidual 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 Nineteenth Century actions

which would bring about complete uniformity among the States in the

area of weights and measures reference standards.

A practical contribution was made toward uniformity in field testing

procedures for weighing and measuring devices by the expansion of the

"training school" project started several years ago. Bureau personnel

assisted State officers in the planning and conduct of such schools, and

gave lectures and demonstrations in about 18 separate jurisdictions.

Traditionally, the National Conference on Weights and Measures has

been one of the principal means of promoting uniformity and raising per- formance standards in weights and measures administration in the United

States. Sponsored by the Bureau, the 43d Annual Conference was held

in Washington, D. C, during the year. Thirty-nine states, Hawaii,

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

this 5-day meeting by 213 delegates out of a total registered attendance

of 424. Education Program

The broad educational program at the Bureau provides an opportunity

for the scientific staff to further their education and increase their opportunities to take on added responsibilities.

The NBS Graduate School Program is divided into courses classed

as NBS out-of-hours, NBS in -hours, and NBS-university sponsored

out-of-hours courses. The program is flexible to meet the varied and

changing needs of the research staff. Research workers from other

Go\ eminent agencies may enroll in the NBS classes if the knowledge

gained will assist them in their official duties. Since the establishment

of the educational program in 1908, over 13,000 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 the

thesis work carried on, under the Bureau program. During the past

year there were 1,265 registrations in 46 courses offered at the Washington

and Boulder laboratories. A summer Junior Scientist-Engineer program is open to the qualified

scientific student with possibilities for a future career at the Bureau. It consists of orientations, training assignments, and discussions with

advisors from the technical divisions. During the past year, approximately 165 students from schools throughout the country participated

in this program.

113
Postdoctoral Resident Research Associateships recommended by the

National Academy of Sciences -National Research Council are tenable

at the National Bureau of Standards, one of two laboratories in the

United States which provide this opportunity. Young scientists at the

Ph. D. level participate in basic research in the physical and mathematical sciences. This is the fourth year of the program and the Bureau

has 8 associates; 3 in chemistry, 3 in physics, and 2 in mathematics.

The educational program also includes a series of seminars, colloquia,

and lectures. The seminars and colloquia are of a specialized nature and

are devoted to detailed discussions. The weekly Scientific Staff Meetings

are of a more general nature. They 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. A course of lectures by specialists in their respective fields on the

establishment and maintenance of standards of measurement was

coordinated by a staff member. This course attempted to fill a need

for spreading more widely through the scientific staff information about

the principles, instruments, and techniques involved in the very accurate experiments required for standards work.

114
5. Appendixes

5.1. Organization of the National Bureau of Standards*

Allen V. Astin, Director Associate Director for Physics

Robert D. Huntoon

Associate Director for Engineering

Archibald T. McPherson

Associate Director for Chemistry

Edward Wichers

Associate Director for Planning Irl C. Schoonover, Acting

Associate Director for Administration Robert S. Walleigh

Associate Director for the Boulder Laboratories Frederick W. Brown

Director Emeritus

Lyman J. Briggs

Assistants to the Director Henry Birnbaum and C. N. Coates

Consultants to the Director

L. F. Curtiss, A. G. McNish, and C. H. Page

SCIENTIFIC AND TECHNICAL DIVISIONS AND

ELECTRICITY AND ELECTRONICS, F. B. Silsbee, Chief

Resistance and Reactance, J. L. Thomas

Electron Devices, C. P. Marsden, Jr. Electrical Instruments, F. M. Defandorf

Magnetic Measurements, I. L. Cooter

Dielectrics, J. D. Hoffman

Engineering Electronics, G. Shapiro

Electronic Instrumentation, C. Stansbury

Electrochemistry, W. J. Hamer

OPTICS AND METROLOGY, I. C. Gardner, Chief Photometry and Colorimetry, L. E. Barbrow

Optical Instruments, F. E. Washer

Photographic Technology, C. S. McCamy

Length, L. V. Judson

Engineering Metrology, I. H. Fullmer

Temperature Physics, J. F. Swindells

Thermodynamics, C. W. Beckett

Cryogenic Physics, R. P. Hudson

Rheology, R. S. Marvin

Free Radicals Research, H. P. Broida

ATOMIC AND RADIATION PHYSICS, L. S. Taylor, Chief Atomic Physics Laboratory

Spectroscopy, B. F. Scribner, Acting

Radiometry, E. K. Pyler

Mass Spectrometry, F. L. Mohler

Solid State Physics, H. P. R. Frederikse

Electron Physics, L. L. Marton

Atomic Physics, L. M. Branscomb

SECTIONS

D. B. Judd, Assistant Chief

HEAT, C. M. Herzfeld, Chief

*As of September 1, 1958. 115
Radiation Physics Laboratory, H. O. Wyckoff, Chief Neutron Physics, R. S. Caswell

Radiation Theory, U. Fano

Radioactivity, W. B. Mann

X-rays, 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, 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, W. Ramberg, Chief

B. L. Wilson, Assistant Chief Sound, R. K. Cook

Mechanical Instruments, E. C. Lloyd

Fluid Mechanics, G. B. Schubauer

Engineering Mechanics, B. L. Wilson

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 W. D. Appel, Assistant Chief Rubber, L. A. Wood

Textiles, W. D. Appel

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

METALLURGY, J. I. Hoffman, Chief T. G. Digges, Assistant Chief Thermal Metallury, T. G. Digges Corrosion, G. A. Ellinger

Chemical Metallurgy, L. L. Wyman Metal Physics, L. M. Kushner

Mechanical Metallurgy, J. A. Bennett

MINERAL PRODUCTS, I. C. Schoonover, Chief

C. H. Hahner, Assistant Chief

Engineering Ceramics, M. D. Burdick

Glass, C. H. Hahner

Refractories, S. Zerfoss

Enameled Metals, W. N. Harrison

Concreting Materials, R. L. Blaine

Constitution and Microstructure, H. F. McMurdie

BUILDING TECHNOLOGY, D. E. Parsons, Chief H. R. Snoke, Assistant Chief

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

APPLIED MATHEMATICS, E. W. Cannon, Chief

F. L. Alt, Assistant Chief Numerical Analysis, P. J. Davis Statistical Engineering, C. Eisenhart

Computation, E. W. Cannon, Acting Mathematical Physics, R. F. Dressler

116
DATA PROCESSING SYSTEMS, S. N. Alexander, Chief SEAC Engineering Group, P. D. Shupe, Digital Systems, A. L. Liener

Jr. Analog Systems, H. K. Skramstad

Components and Techniques, R. D. Applications Engineering, S. N. AlexElbourn ander, Acting

Digital Circuitry, S. Greenwald

OFFICE OF WEIGHTS AND MEASURES, W. S. Bussey, Chief OFFICE OF BASIC INSTRUMENTATION, W. A. Wildhack, Chief OFFICE OF TECHNICAL INFORMATION, W. R. Tilley, Chief ADMINISTRATIVE DIVISIONS

Accounting, H. E. Hardaway Management Planning, Ivan Asay

Personnel, G. R. Porter Budget, N. L. Christeller

Administrative Services, H. P. Dalzell Internal Audit, J. P. Menzer

Shops, F. P. Brown Plant, H. Graham

Supply, G. B. Kefover

BOULDER LABORATORIES, F. W. Brown, Director

Boulder. Colorado CRYOGENIC ENGINEERING, R. B. Scott, Chief

Assistant Chief, B. W. Birmingham

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 Upper Atmosphere Research, T. N. Gautier

Ionospheric Research, E. K. Smith

Regular Propagation Services, W. B. Chadwick

Sun-Earth Relationships, Alan Shapley

VHF Research, K. L. Bowles, Acting

Ionospheric Communication Systems, R. C. Kirby, Acting

RADIO PROPAGATION ENGINEERING,* K. A. Norton, Chief

Assistant Chief for Research and Development, J. W. Herbstreit, Jr. Assistant Chief for Engineering, Logistics, and Technical Administration, K. O. Hornberg

Data Reduction Instrumentation, W. E. Johnson

Modulation Systems, A. D. Watt

Navigation Systems, G. Hefley

Radio Noise, W. Q. Crichlow

Tropospheric Measurements, C F. Peterson

Tropospheric Analysis, P. L. Rice

Radio Systems Application Engineering, R. S. Kirby

Radio-Meteorology, B. R. Bean

RADIO STANDARDS, W. D. George, Acting Chief

Asst. Chief for Radio Frequencies, W. D. George

Asst. Chief for Microwave Frequencies, D. M. Kerns

High Frequency Electrical Standards, M. C. Selby

Radio Broadcast Service, A. H. Morgan

High Frequency Impedance Standards, J. L. Dalke

Electronic Calibration Center, H. W. Lance

Microwave Physics, J. M. Richardson

Microwave Circuit Standards, R. W. Beatty

ADMINISTRATIVE DIVISION, S. W. J. Welch

*The above two divisions comprise the Central Radio Propagation Laboratory. 117
NATIONAL BUREAU OF STANDARDS

FIELD ESTABLISHMENTS

Lamp Inspector, Brookline 46, 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.

Cheyenne Mt. Field Station, Colorado Springs, Colo. Radio Transmitting Station WWV, Beltsville, Md.

Radio Propagation Field Stations Anchorage Alaska Barrow, Alaska

Carthage, HI. Fort Belvoir, Va.

Gunbarrell Hill, Longmont, Colo. Radio Noise Recording Stations

Bill, Wyo.

Front Royal, Va. Kauai, Hawaii

Long Branch, 111. Margarita, Panama, Canal Zone San Juan, P. R.

Sterling, Va.

5.2. Fiscal Data on NBS Program

PROGRAM AND SOURCE OF FINANCING Obligations Incurred (in thousands

of dollars)

Supported by NBS Appropriations

Operating Program:

Construction and Facilities Programs:

Plant and Equipment

Construction of Facilities Total NBS Appropriations

Supported by Other Funds

Research and Development Programs:

Department of Defense and AEC . . Non-Governmental Sources

Calibrations and Standard Samples. . . . Reimbursable Administrative Services. Total, Supported by Other Funds . . . Total Program

$9, 723. 5 $470. 2

3. 1 473.

3

$10,196.8

13, 265.

1

3, 167. 5 168.4

16, 601.

1, 137. 8

1, 222. 7

18, 961. 5

29, 158. 3

118
5.3. Advisory Committees

STATUTORY VISITING COMMITTEE

[Reports annually to Secretary of Commerce on NBS activities (Dates indicate expiration of

appointment.)] Dr. M. J. Kelly, President, Bell Telephone Laboratories, Inc. (1962), Chairman

Dr. Clyde E. Williams, President, Battelle Memorial Institute (1958) Dr. Crawford H. Greenewalt, President, E. I. du Pont de Nemours & Co. (1959) Dr. Detlev W. Bronk, President, National Academy of Sciences (1960) Professor F. Seitz, University of Illinois (1961) Technical Advisory Committees

[Designated by leading scientific and technical societies to advise NBS Director in specific technical

areas. Members listed served during fiscal year 1958.1 AMERICAN INSTITUTE OF ELECTRICAL ENGINEERS

Dr. Ralph Brown, Millburn, N. J. Dr. C. G. Suits, General Electric Company

Mr. Robert C. Sprague, Sprague Electric Company

Dr. J. A. Hutcheson, Westinghouse Electric Corporation

Mr. H. P. Corwith, Western Union Telegraph Company

Professor W. A. Lewis, Jr., Illinois Institute of Technology

INSTITUTE OF RADIO ENGINEERS

Professor Henry G. Booker, Cornell University

Mr. Stuart L. Bailey, Jansky & Bailey

Professor E. C. Jordon, University of Illinois Professor A. H. Waynick, Pennsylvania State University

Professor J. B. Wiesner, Massachusetts Institute of Technology Dr. H. W. Wells, Carnegie Institution of Washington

AMERICAN INSTITUTE OF PHYSICS

Professor R. B. Lindsay, Brown University

Professor D. M. Dennison, University of Michigan

Dean R. A. Sawyer, University of Michigan

Professor Mark W. Zemansky, City College of New York

Professor A. O. C. Nier, University of Minnesota Dr. H. M. Parker, General Electric Company

Dr. Otto Oldenberg, Harvard University

Professor John Strong, Johns Hopkins University

Professor Henry A. Fairbank, Yale University

Professor H. F. Olson, Radio Corporation of America

Professor J. W. M. DuMond, California Institute of Technology

Professor J. E. Mayer, University of Chicago

Professor John Bardeen, University of Illinois Professor P. Kusch, Columbia University

CONFERENCE ORGANIZATION FOR MATHEMATICAL SCIENCES

Professor A. H. Taub, University of Illinois Dean Mina Rees, Hunter College

Professor Philip M. Morse, Massachusetts Institute of Technology

Professor David Blackwell, University of California Professor Mark Kac, Cornell University Dr. E. U. Condon, Washington University

119
AMERICAN INSTITUTE OF MINING AND METALLURGICAL

ENGINEERS

Mr. Clarence E. Sims, Battelle Memorial Institute Dr. Maxwell Gensamer, Columbia University Dr. E. C. Smith, Republic Steel Corporation Dr. Cyril S. Smith, University of Cbicago Dr. Albert J. Phillips, American Smelting & Refining Company

Dr. Clarence Zener, Westinghouse Electric Corporation

AMERICAN CHEMICAL SOCIETY

Professor Farrington Daniels, University of Wisconsin Professor N. Howell Furman, Princeton University

Professor C. S. Marvel, University of Illinois Dr. Milton Harris, Harris Research Laboratories Dr. J. R. Ruhoff, Mallinckrodt Cbemical Works

Dr. Norman A. Shepard, Stamford, Conn. AMERICAN CERAMIC SOCIETY

Dr. A. C. Siefert, Owens-Corning Glass Corporation

Mr. Paul V. Johnson, Structural Clay Products Research Founda tion Dean Elburt Osborn, Pennsylvania State University

Mr. Harry W. Thiemecke, Homer Laughlin China Company

Mr. H. N. Kraner, Bethlehem Steel Company

Mr. Raymond C. Reese, Toledo, Ohio

Mr. John T. Roberts, Glen Ellyn, 111. AMERICAN SOCIETY OF MECHANICAL ENGINEERS

Dean Dana Young, Yale University

Professor S. R. Beitler, Ohio State University

Professor C. Harold Berry, Harvard University

Mr. Paul V. Miller, Taft Pierce Manufacturing Company

AMERICAN SOCIETY OF CIVIL ENGINEERS

Dr. G. H. Hickox, Engineer Research and Development Laboratories, Fort Belvoir, Va. Dr. A. T. Ippen, Massachusetts Institute of Technology

Mr. Raymond C. Reese, Toledo, Ohio

NATIONAL CONFERENCE ON WEIGHTS AND MEASURES

Mr. Charles M. Fuller, Sealer of Weights and Measures, Los Angeles, California Mr. Seth T. Shaw, Safeway Stores, Inc. Mr. C. J. McCaffrey, Ralph N. Brodie Company, Inc. Mr. W. A. Scheurer, Exact Weight Scale Company

Mr. Roland Meek, State Board of Health, Indianapolis, Indiana Professor L. J. Gordon, Director, Weights and Measures Research Center, Denison

University

AMERICAN STANDARDS ASSOCIATION

Mr. H. Thomas Hallowell, Jr., Standard Pressed Steel Company

Mr. John R. Townsend, Sandia Corporation

Mr. Arthur S. Johnson, American Mutual Liability Insurance Company

Vice Admiral G. F. Hussey, Jr., USN (Ret), American Standards Association Mr. Cyril Ainsworth, American Standards Association AMERICAN SOCIETY FOR TESTING MATERIALS

Dr. K. B. Woods, Purdue University, West Lafayette, Indiana Dr. A. Allan Bates, Portland Cement Association Mr. T. A. Boyd, General Motors Corporation

Mr. Aiken W. Fisher, Fisher Scientific Company

Mr. R. E. Peterson, Westinghouse Research Laboratories 120
5.4. Awards'and Honors

Recognition of the Bureau's contributions to science and technology often takes the form of awards and honors from academic, industrial, and professional groups. The

following list reflects such recognition bestowed on Bureau staff members during the

fiscal year 1958. RECIPIENT

Alexander, S. N.

Austin, A. V.

Beckett, C. W.

Brenner, Abner

Brode, W. R. DE MlNJER, C. H.

Eisenhart, Churchill

Elrotjrn, R. D.

Gross, D. Gardner, I. C. Harvey, Kenneth B. Herbstreit, Jack W.

Hoffman, James I. Hijntoon, R. D. Leaderman, Herhert

Leiner, Alan L. Loftus, J. J. Marton, L. McCrackin, Frank L. McNesby, James R. McPherson, A. T. Reinhart, Frank W.

Robertson, A. F. Ruffa, Richard A. Scribner, Bourdon F. Selicer, Howard H. Youden. W. J.

HONOR

Award

Honorary Doctor of Science Degree Ejection to Membership

Ludwig Mond Prize for Paper

Richards Memorial Lecturer Heussner Award for Paper

Elected President Heussner Award for Paper

RockefelleriPublic ServicelAward, Award

Richard L. Templin Award

Elected President Fellowship grant to the Univ. of Amsterdam

Fellowship Award

Gold Medal Alumni Award

Achievement Award

Alumni Recognition Award

Fulbright Fellowship Award

Richard L. Templin Award

Elected President

Certificate Rockefeller Public Service Award

Elected President Honorary Doctor of Science Degree Richard L. Templin Award

Fellowship at,Catholic University Award of Merit

Rockefeller Public Service Award

Honorary Election to Life Membership

SOURCE

Washington Academy of Sciences. George Washington University. American' Philosophical Society. American Academy of Arts and

Sciences. Institution of Mechanical Engineers

of London. The Electrochemical Society. American Electroplaters' Society. American Association for the Advancement of Science. American Electroplaters' Society,

i Administered by Princeton Univ. as a

nationaLjtrust. Washington Academy of Sciences. American Society for Testing Materials. Optical Society of America.

National Research Council of Canada.

Institute of Radio Engineers. Franklin & Marshall College. Alumni Association of Iowa Stale Teachers College. American University. Department of State. Washington Academy of Sciences. American Society for Testing Materials. Washington'Philosophicial Society. D. C. Council of Engineering and

Architectural Societies. Administered by Princeton Univ. as a national trust. Washington Academy of Sciences Juniata College. American Society for Testing Materials. Knights of Columbus. American Society for Testing Materials. Administered by Princeton Univ. as

a national trust. International Statistical Institute. DEPARTMENT OF COMMERCE AWARDS

Barbrow, Louis E.

Bliss, Lloyd C. Brown, Frank P. Bunting, Elmer N.

Crossette, Marie H.

Fuller, Everett G. Fullmer, Irvin H. Hague, John L. Hayward, Evans

loeb en stein, w. v. Lowell, Percival D. Maryott, Arthur A. Matter, Floyd A. Selicer, Howard H. Sweeney, William T. Trees, Richard E. Wood, Lawrence A. Wyman, LeRoy L. Bean, Howard S. Brode, Wallace R. Mann, Wilfrid B.

Meritorious Service Meritorious Service Meritorious Service Meritorious Service Meritorious Service Meritorious ServiceAward

Award

Award Award

Award

Award

Meritorious Service Award

Meritorious Service Award

Meritorious Service Award

Meritorious Service Award

Meritorious Service Award

Meritorious Service Award

Meritorious Service Award

Meritorious Service Award

Meritorious Service Award

Meritorious Service Award

Meritorious Service Award

Meritorious Service Award

Exceptional Service Award

Exceptional Service Award

Exceptional Service Award

Photometry and Colorimetry. Concreting Materials. Instrumenta tion. Phase Equilibrium Studies. Organic and Fibrous Materials.

Elastic Scattering of High-energy X-rays by Nuclei. Standardization of Screw Threads. Complex Metal Alloys. Elastic Scattering of High-energy X-rays by Nuclei. Adsorption and Catalysis. Electronic Instrumentation.

Dielectric Properties, of Compressed

Gases at Microwave Frequencies. Crystal Chemistry.

Liquid Scintillation Counting of Beta -emitting Radioactive Nuclides. Dental Materials. Quantum Theory of Complex Atomic

Spectra. Rubber.

Alloy Theory. Metering of Fluids. Chemical Spectroscopy. Radionuclide Standards.

121
5.5. 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 subject matter of the reports embraces the

fields of electricity and electronics, optics and metrology, heat, atomic and radiation

physics, chemistry, mechanics, organic and fibrous materials, metallurgy, mineral

products, building technology, applied mathematics, data processing systems, basic instrumentation, weights and measures, cryogenic engineering and radio propagation.

(Annual subscription: domestic, $5.00; $1.75 additional for foreign mailing.) Volume 59, July-December 1957 2768. Thermal length changes of some refractory castables. S. J. Schneider and

L. E. Mong.

2769. Precise intercomparison of acids by differential potentiometric titration with hydrogen electrodes. Roger G. Bates and Edward Wichers.

2770. Mixed-path ground-wave propagation: 2. Larger distances. James R. Wait

and James Householder.

2771. A spectroscopic study of oils used in oil-extended rubber. Frederic J. Linnig

and James E. Stewart.

2772. Infrared spectra of sugar acetates in solution. Horace S. Isbell, Francis A.

Smith, E. Carroll Creitz, Harriet L. Frush, Joseph D. Moyer, and James E. Stewart.

2773. A problem in self-heating of a spherical body. S. M. Genensky.

2774. Properties of arsenic sulfide glass. Francis W. Glaze, Douglas H. Blackburn, Jerome S. Osmalov, Donald Hubbard, and Mason H. Black.

2775. Thermal conductivity of beryllium oxide from 40° to 750° C. David A. Ditmars

and Defoe C. Ginnings.

2776. A self-balancing direct -current bridge for accurate bolometric power measurements. Glenn F. Engen.

2777. Some observations on hydrated monocalcium aluminate and monostrontium

aluminate. Elmer T. Carlson. 2778. Turbidity and viscosity measurements on some cationic detergents in water and in sodium chloride solutions. Lawrence M. Kushner, Willard D. Hubbard,

and Rebecca A. Parker.

2779. Relative stress-optical coefficients of some National Bureau of Standards

optical glasses. Roy M. Waxier and Albert Napolitano.

2780. Physicochemical studies of the destructive alkali-aggregate reaction in concrete. Robert G. Pike and Donald Hubbard.

2781. Insulated loop antenna immersed in a conducting medium. James R. Wait.

2782. Noncrystal ionic model for silica glass. Leroy W. Tilton. 2783. A computation of cyclic cubic units. Harvey Cohn and Saul Gorn.

2784. Estimation of the frequencies of thin elastic plates with free edges. Tosio Kato, Hiroshi Fujita, Yoshimoto Nakata, and Morris Newman.

2785. A thermochemical study of the reaction of calcium hydroxide, silica gel, and

water. Edwin S. Newman.

2786. On some expansions for Bessel integral functions. F. Oberhettinger.

2787. Table of the first moment of ranked extremes. Julius Lieblein and Herbert

E. Salzer. 2788. An approximate expression for gamma-ray degradation spectra. U. Fano

and Ann T. Nelms.

2789. Some infrared bands of deuterium sulfide. Harry C. Allen, Jr., Earle K.

Plyler, and L. R. Blaine. 2790. Some effects of low temperatures and notch depth on the mechanical behavior

of an annealed commercially pure titanium. Glenn W. Geil and Nesbit L. Carwile. 2791. Determination and use of the sag point as a reference point in the heating of

glasses. Sam Spinner, Given W. Cleek, and Edgar H. Hamilton.

2792. Formulas for inverse osculatory interpolation in the complex plane. Herbert

E. Salzer. 2793. An X-ray study of textural stresses in two-phase alloys. C. J. Newton and

H. C. Vacher.

2794. Dissociation of 4-chloro-4'-aminodiphenylsulfone. Elizabeth E. Sager and

Fleur C. Byers.

2795. Speed of sound in water by a direct method. Martin Greenspan and Carroll E. Tschiegg.

2796. Pattern of a flush-mounted microwave antenna. James R. Wait. 122
2797. Standards for pH measurements from 60° to 95° C. Vincent E. Bower and

Roger G. Bates.

2798. A numerical study of Dedekind's cubic class number formula. Harvey Cohn.

2799. Impact properties of slack-quenched alloy steels. Melvin R. Meyerson and

Samuel J. Rosenberg.

2800. Synthesis of OMabeled L-sorbose and L-ascorbic acid. H. L. Frush and H. S'

Isbell. 2801. A determination of the gamma-ray emission of radium. Frank H. Attix and

Victor H. Ritz. 2802. Radiation from slots on dielectric -clad and corrugated cylinders. James R. Wait and Alyce M. Conda.

2803. Infrared emission spectrum of methane at 3.3 microns. Earle K. Plyler and

Lamdin R. Blaine. 2804. Term analysis of the first spectrum of rhenium (Re i). P. F. A. Klinkenberg,

W. F. Meggers, R. Velasco, and M. A. Catalan.

2805. An apparatus for measurement of thermal conductivity of solids at low temperatures. Robert L. Powell, William M. Rogers, and Don O. Coffin. 2806. Some factors affecting the surface area of hydrated portland cement as deter- mined by water-vapor and nitrogen adsorption. L. A. Tomes, C. M. Hunt, and

R. L. Blaine. 2807. Excitation of surface waves on conducting, stratified, dielectric-clad, and cor- rugated surfaces. James R. Wait.

2808. Cunife wire magnets of small size. Irvin L. Cooter and Robert E. Mundy.

2809. Interpretation of mass spectra of condensates from urban atmospheres. E. R. Weaver, E. E. Hughes, Shirley M. Gunther, Schuford Schuhmann, Nancy T. Redfearn, and Ralph Gorden, Jr. 2810. Infrared emission spectrum of silicon carbide heating elements. James E. Stewart and Joseph C. Richmond.

2811. Increased chemical reactivity of the surface compared with that in the bulk volume of Britton-Robinson universal buffers. Robert G. Pike and Donald

Hubbard.

2812. Photometric determination of tungsten in steel and titanium alloys with dithiol. Lawrence A. Machlan and John L. Hague.

2813. On the most general form of the compatibility equations and the conditions of

integrability of strain rate and strain. Edmund H. Brown.

2814. An apparatus for measuring the piezoresistivity of semiconductors. R. F. Potter and W. J. McKean.

Volume 60, January-June 1958 2815. The condition of certain matrices, III. John Todd.

2816. Infrared study of some structural changes in natural rubber during vulcanization. Frederic J. Linnig and James E. Stewart.

2817. Crystal structure of barium hydrogen orthophosphate. Gordon Burley.

2818. A study of sampling of flame gases. C. Halpern and F. W. Ruegg.

2819. Pyrolysis of polyamides. Sidney Straus and Leo A. Wall.

2820. Some thermodynamic properties of the systems polybutadiene-benzene and

polyisobutene-benzene. R. S. Jessup. 2821. Infrared measurements with a small grating from 100 to 300 microns. Earle K. Plyler and L. R. Blaine. 2822. A low-frequency annular-slot antenna. James R. Wait.

2823. Relation between the absorption spectra and the chemical constitution of

dyes: XXIX. Interaction of direct azo dyes in aqueous solution. May N. Inscoe, John H. Gould, Mary E. Corning, and Wallace R. Brode.

2824. Energy spectra of cascade electrons and photons. Charles A. Olson and

Lewis V. Spencer. 2825. Observer differences in color -mixture functions studied by means of a pair of metameric grays. Kenneth L. Kelly. 2826. Precise evaluation of surface area with indirectly calculated dead space. William

V. Loebenstein.

2827. Sample calculations of gamma-ray penetration into shelters: Contributions

of sky shine and roof contamination. Martin J. Berger and James C. Lamkin.

2828. Heat content of sodium borohydride and of potassium borohydride from 0° C

to 400° C. Thomas B. Douglas and Ann W. Harman.

2829. Infrared spectra of crystalline polyphenyls. James E. Stewart and Max

Hellmann.

2830. On the application of steam-driven water jets for propulsion purposes. J. M.

Burgers and A. Ghaffari. 2831. Mass spectra and relative sensitivities of some polyphenyls. Paul Bradt and

Fred L. Mohler. 489867—59 9 123
2832. Infrared spectra of thermally degraded poly (vinyl chloride). Robert R.

Stromberg, Sidney Straus, and Bernard G. Achhammer.

2833. Current and potential relations for the cathodic protection of steel in salt water. W. J. Schwerdtfeger.

2834. Joule-Thomson process in the liquefaction of helium. Edmund H. Brown and

John W. Dean.

2835. Changes in the properties of an asphalt during the blowing operation. L. R.

Kleinschmidt and H. R. Snoke.

2836. Creep of annealed nickel, copper, and two nickel-copper alloys. William D.

Jenkins and Carl R. Johnson.

2837. Stress-strain relation of pure-gum rubber vulcanizates in compression and tension. Lawrence A. Wood.

2838. Tables for diagonalizing second-order matrices. R. E. Trees and C. DeW.

Coleman.

2839. Effects of capillary shape on flow characteristics and degradation of polymer

solutions. Hobart S.White and Harriet V. Belcher. 2840. Ortho-para catalysis in liquid-hydrogen production. D. H. Weitzel, W. V.

Loebenstein, J. W. Draper, and O. E. Park.

2841. Degradation of cellulose in a vacuum with ultraviolet light. Joseph H. Flynn,

Williani K. Wilson, and William L. Morrow.

2842. Cavity ionization as a function of wall material. Frank H. Attix, LeRoy

DeLaVergne, and Victor H. Ritz. 2843. Fragmentation of waterdrops in the zone behind an air shock. Olive G. Engel.

2844. Transient radio-frequency ground waves over the surface of a finitely conducting plane earth. J. R. Johler. 2845. Measurement of current with a Pellat-type electrodynamometer. R. L. Driscoll. 2846. Measurement of current with the National Bureau of Standards current bal- ance. R. L. Driscoll and R. D. Cutkosky.

2847. Radial distribution of the center of gravity of random points on a unit circle. F. Scheid. 2848. An adiabatic calorimeter for the range 30° to 500° C. E. D. West and D. C. Gmnings.

2849. An evaluation of the luminous-transmittance requirements for railroad-signal

glassware in terms of standard source A of the International Commission on Illumination. Francis C. Breckenridge.

2850. Random notes on matrices. K. Goldberg.

2851. Range finders using projected images. Robert E. Stephens.

2852. Effect of rib flexibility on the vibration modes of a delta-wing aircraft. Wil- helmina D. Kroll. 2853. Thermal degradation of cellulosic materials. S. L. Madorsky, V. E. Hart, and

S. Straus. 2854. Role of vitrons in alkali silicate binary glasses. Leroy W. Tilton. 2855. Elastic problem for a ring of uniform force in an infinite body. William H. Pell. 2856. Description and analysis of the second spectrum of molybdenum, Mo n. C. C.

Kiess. 2857. Forces on cylinders and plates in an oscillating fluid. Garbis H. Keulegan and

Lloyd H. Carpenter.

2858. Reaction of portland cement with carbon dioxide. Charles M. Hunt, Vernon

Dantzler, Lewis A. Tomes, and Raymond L. Blaine. 2859. Average energy of sulfur -35 beta decay. Howard H. Seliger, Wilfrid B. Mann,

and Lucy M. Cavallo. 2860. Effect of structure on the thermal decomposition of polymers. Leo A. Wall and

Roland E. Florin. 2861. Comparison of theoretical and empirical relations between the shear modulus

and torsional resonance frequencies for bars of rectangular cross section. Sam

Spinner and Rudolph C. Valore, Jr. 2862. Specific volume and degree of crystallinity of semicrystalline poly(chlorotrifluorethylene), and estimated specific volumes of the pure amorphous and crystalline

phases. John D. Hoffman and James J. Weeks.

2863. Heat and ultraviolet aging of poly(vinyl chloride). Charles F. Bersch, Mary R. Harvey, and Bernard G. Achhammer.

2864. Determination of water vapor from the change in electrical resistance of a hygroscopic film. Elmer R. Weaver, Ernest E. Hughes, and Albert W. Diniak.

2865. Improved bridge method for the measurement of core losses in ferromagnetic

materials at high flux densities. William P. Harris and Irvin L. Cooter. 2866. Stress-strain relationships in yarns subjected to rapid impact loading: 5. Wave

propagation in long textile yarns impacted transversely. Jack C. Smith, Frank L. McCrackin, and Herbert F. Schiefer.

124
2867. Measurement of flame speeds by a nozzle burner method. Carl Halpern.

2868. Growth of preferentially oriented aluminum single crystals. Theodore H. Orem.

2869. Marginal performance of corrected ophthalmic lenses. Francis E. Washer and

Walter R. Darling. 2870. Enthalpy and heat capacity from 0° to 900° C of three nickel-chromium-iron alloys of different carbon contents. Thomas B. Douglas and Ann W. Harman.

2871. Relative strengths of forty aromatic carboxylic acids in benzene at 25° C. Marion Maclean Davis and Hannah B. Hetzer.

2872. Shape of the liquidus surface as a criterion of stable glass formation. Edgar H.

Hamilton and Given W. Cleek. 2873. Twinned epitaxy of copper on copper. Theodore H. Orem.

2874. Dielectric constant of deuterium oxide. Cyrus G. Malmberg.

2875. Additional abscissas and weights for Gaussian quadratures of high order: values

for n-64, 80, and 96. Philip Davis and Philip Rabinowitz.

2876. Mass spectra of aromatic hydrocarbons filtered from smoky air. Fred L. Mohler, Paul Bradt, and Vernon H. Dibeler. Technical News Bulletin. This monthly publication summarizes the current re- search 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 national and international conferences on fundamental science in which

the Bureau 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; 75 cents additional for foreign mailing.) Basic Radio Propagation Predictions. This is a monthly publication for those con- cerned with radio communication in determining the best sky-wave frequencies over any path at any time of day for average conditions for the month of prediction, which

are made three 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 highest frequency of sporadic E in excess of 15 Mc are included. In

addition, there are various maps, charts, diagrams, and nomograms needed to make

practical application of the world-contour charts, together with examples of their use. (Annual subscription: domestic, $1.00; 50 cents additional for foreign mailing.)

Circulars. Circulars are compilations of information on various subjects related

to the Bureau's scientific, technical, and engineering activities. They include not

only the results of Bureau studies, but give data of general interest from other sources. 460. Supplement. Supplementary list of publications of the National Bureau of Standards, July 1, 1947, to June 30, 1957.

467. Volume III. Atomic energy levels. Charlotte E. Moore.

539. Volume 7. Standard X-ray diffraction powder patterns. Howard E. Swanson,

Nancy T. Gilfrich, and Marlene I. Cook.

562. Supplement 1. Bibliography of research on deuterium and tritium compounds,

1953 and 1954. Virginia R. Johnson, Lawrence M. Brown, and Abraham S. Fried- man.

584. Simulator for use in development of jet engine controls. Emile S. Sherrard.

585. The measurement of thickness. George Keinath.

586. Electric hygrometers. Arnold Wexler.

587. Electroforming of waveguide components for the millimeter -wavelength range. Albert A. Feldmann.

588. Determination and correlation of flow capacities of pneumatic components. D. H. Tsai and M. M. Slawsky.

590. Methods of testing thermocouples and thermocouple materials. Wm. F. Roeser and S. T. Lonberger.

591. Section 1. System design of digital computers at the National Bureau of Standards: methods for high-speed addition and multiplication.

1. A logic for high-speed addition, by A. Weinberger and J. L. Smith.

2. Shortcut multiplication for binary digital computers, by J. L. Smith and

A. Weinberger.

592. Nickel and its alloys. J. G. Thompson.

593. The federal basis for weights and measures. Ralph W. Smith.

594. Preparation, maintenance, and application of standards of radioactivity. W. B. Mann and H. H. Seliger. 125
Miscellaneous Publications. As the name implies, this series includes material, which, because of its character or because of its size, does not fit into any of the other

regular publication series. Some of these are charts, administrative pamphlets,

Annual Reports, Weights and Measures Conference Reports, and other subjects ap- propriate to the Miscellaneous series. 221. Hydraulic research in the United States, 1957. Helen K. Middleton.

222. Report of the 42d National Conference on Weights and Measures, 1957.

223. Annual report, 1957, National Bureau of Standards. Handbooks. These are recommended codes of engineering and industrial practice,

including safety codes, developed in cooperation with the national organizations and

others concerned. In many cases the recommended requirements are given official status through their incorporation in local ordinances by State and municipal regulatory

bodies.

28. (1957)—Part I. ScreAv -thread standards for federal services 1957.

63. Protection against neutron radiation up to 30 million electron volts.

64. Design of free-air ionization chambers.

65. Safe handling of bodies containing radioactive isotopes.

66. Safe design and use of industrial beta-ray sources. Applied Mathematics Series. Mathematical tables, manuals, and studies. 49. Further contributions to the solution of simultaneous linear equations and the determination of eigenvalues.

51. Tables of the exponential integral for complex arguments.

52. Integrals of airy functions.

53. Table of natural logarithms for arguments between five and ten to sixteen decimal

places. 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 design criteria. The subjects of primary interest are the properties of building

materials, structures, equipment, and facilities. 151. Thermal resistance of airspaces and fibrous insulations bounded by reflective surfaces. H. E. Robinson, L. A. Cosgrove, and F. J. Powell. Publications in Outside Journals*

Alexander, S. N., Survey of computer development and applications, Proc. Conference on Science and Tech. for the Deans of Engineering, Purdue Univ. (Sept. 1957). Allen, H. C, Jr., and Plyler, E. K., The structure of ethylene from infrared spectra,

J. Am. Chem. Soc. 80, 2673 (1958).

Allisy, A., DeLaVergne, L., and Wyckoff, H. O., An intercomparison of the French

and U. S. roentgen ray standards, Acta Radiol. 48, 6, 486 (Dec. 1957). Ambler, E., Hayward, R. W., Hoppes, D. D., and Hudson, R. P., Beta-gamma correla- tions from polarized manganese-52, Phys. Rev. (May 1958). Also in Proc. Inter- national Congress on Nuclear Physics (Paris, July 1958) and Proc. of Kamerlingh Onnes Conference on Low Temperature Physics (Leiden, June 1958). Ambler, E., Hayward, R. W., Hoppes, D. D., Hudson, R. P., and Wu, C. S., Further

experiments on /3-decay of polarized nuclei, Phys. Rev. 106, 1361 (1957). Ambler, E., Hayward, R. W., Hoppes, D. D., and Hudson, R. P., Further experiments on /3-decay of polarized nuclei, Phys. Rev. 106, 508 (1957). Ambler, E., and Hudson, R. P., Absolute temperature below 1° K: chromic methylammonium alum as a thermometric substance, J. Chem. Phys. 27, 378 (1957). Ambler, E., Low temperature physics, Science 126, 1096-1097 (1957). Ambler, E., Hayward, R. W., Hoppes, D. D., and Hudson, R. P., Absence of inter- ference effects in the /3-decay of polarized CO56 and CO58 nuclei, Phys. Rev. 108, 503 (1957). Appel, W. D., Progress on international standards, Daily News Record, p. 36 (Oct. 10, 1957).

*For completeness, a few references to publications issued previous to July 1957 are included. 126
Appel, W. D., Test for dimensional changes in woven fabrics in high temperature

laundering, Am. Dyestuff Reptr. 47, 7, 213 (Apr. 7, 1958). Armstrong, G. T., Jessup, R. S., and Mears, T. W., Net heat of combustion of aviation

asoline and its correlation with other properties, Chem. & Eng. Data Series 3, 20

1958). Astin, A. V., Scientists' and public's responsibility, Phys. Today 10, 11, 23-27 (Nov.

1957). Astin, A. \., A service for the Nation's technology, Mag. of Standards 28, 7, 396-199

(July 1957). Ballard, C. R., and Bouche, R. R., A pretied tie for communication line wires, Conference Paper No. CP 58-266 presented at the Annual Meeting of AIEE, Feb.

1958. Bass, A. M., and Broida, H. P., Absorption spectra of solids condensed at low temperatures from electric discharges, J. Mol. Spectroscopy 2, 42 (1958). Bay, Z., and Seliger, H. H., Collection of ions produced by alpha particles in air, Bull. Am. Phys. Soc. II, 3, No. 3 (1958). Bay, Z., Seliger, H. H., and Wyckoff, H. O., Absolute measurement of W a ir for sulfur- 35 beta rays, Radiation Research 7, No. 6, 558-569 (Dec. 1957). Bay, Z., Techniques and theory of fast coincidence experiments, IRE Trans, on

Nuclear Sci. NS3, No. 4, 12 (1956). 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 an- harmonic oscillators, J. Chem. Phys. 28, 700 (1958). Bean, B. R., and Cahoon, B, A., A note on the climatic variation of absolute humidity,

Bull. Am. Meteorol. Soc. 38, No. 7, 395-398 (Sept. 1957). Bean, B. R., and Abbott, R., Oxygen and water vapor absorption of radio waves in the atmosphere, Geofis. pura e appl. 37, 127-144 (1957). Bean, B. R., Sur i'utilisation des observations meteorologiques courantes en propagation radioelectrique, L'Onde Electrique 37, No. 362, 411-415 (May 1957). Bean, B. R., and Cahoon, B. A., The use of surface weather observation to predict the total atmospheric bending of radio rays at small elevation angles, IRE Proc. 45, 1545-1546 (Nov. 1957). Bean, L., The strontium oxide content of portland cements, ASTM Bull. No. 224

(Sept. 1957). Bean, L., Head regulator for cutoff valve, Anal. Chem. 29, No. 6, 987 (June 1957). Beatty, R. W., An adjustable sliding termination for rectangular wave guide, IRE

Trans, on Microw. Theory MTT-3, 192-194 (July 1957). Beckett, C. W., Green, M. S., and Woolley, H. W., Thermochemistry and thermo- dynamics of substances, Ann. Rev. Phys. Chem. 7, 287-310 (1956). Beckett, C. W., and Haar, L., Thermodynamic properties of high temperatures, Pro.

Inst. Mech. Engrs. (London) Paper 4 (July 1957). Benedict, W. S., and Plyler, E. K., Vibration-rotation bands of ammonia II—the molecular dimensions and harmonic frequencies of ammonia and deuterated ammonia, Can. J. Phys. 35, 1235-1241 (1957). Bennett, J. A., and Holshouser, W. L., Mechanical failures of metals in service, Engineering Materials Handbook 36, 2-10, (1958). Berger, M. J., Calculation of energy dissipation by gamma radiation near the interface between two media, J. Appl. Phys. 28, No. 12, 1502-1508 (Dec. 1957). Bersch, C. F., McCrackin, F. L., and Plitt, K. F., The effects of rates of straining on some tensile properties of polyester film, Modern Plastics 35, 171 (Oct. 1957). Bestul, A. B., Capillary viscometry, J. Soc. Cosmetic Chemists 8, No. 6, 345-370

(Nov. 1957). Birmingham, B. W., A mechanical refrigeration process for the no-loss storage of liquid

hydrogen, Refrig. Eng. 65, 42-44, 86 (July 1957). Birnbaum, G., iNonresonant absorption of symmetric top molecules. Shape of the nonresonant spectra, J. Chem. Phys. 27, No. 2, 360-368 (Aug. 1957). Bouche, R. R., and Tate, D. R., Autographic stress-strain recorders, ASTM Bull. No.

228 (Feb. 1958). Bouche, R. R., Lee, A. A., Ballard, C. R., and On, F. J., Wind-induced vibration of telephone and distribution conductors, AIEE Middle Eastern District Meeting

Conference Paper (April 1958). Bowles, K. L., and Cohen, R. S., Equatorial region ionospheric scatter research bv the NBS during IGY, QST (Aug. 1957). Branscomb, L. M., Smith, S. J., Burch, D. S., Geltman, S., Photodetachment studies of negative ions, Third International Conference on Ionization Phenomena in Gases, Venice (1957). Breckenridge, F. C, Fifty years of signal lighting, Ilium. Eng. 53, 311 (June 1958). Brickwedde, F. G., The helium-vapor pressure scale of temperatures, Phys. Today 11, 23 (1958). 127
Brodd, R. J., Heats of adsorption from charge-transfer complex theory, J. Phys. Chem.

62, 54-55 (1958). Broida, H. P., Spectroscopic studies of solids condensed at 4.2° K from electric dis- charge through nitrogen, oxygen, hydrogen, water and ammonia, The Threshold of Space (Pergamon Press, London, 1957). Broida, H. P., and Peyron, M., Luminescence of solid nitrogen (4.2° K) containing atoms or free radicals. Effect of dilution by argon, J. Phys. Radium 18, 593 (1957). Broida, H. P., and Shuler, K. E., Spectroscopic study of electronic flame temperatures

and energy distributions, J. Chem. Phys. 27, No. 4, 933-939 (Oct. 1957). Broida, H. P., Luminescence de l'azote solide (4.2° K) contenant des atomes ou radi- caux libres. Effet de la dilution par 1' argon (1), Le J. de Physique et le radium 18, 593-595 (Oct. 1957). Broida, H. P., and Moore, C. E., Molecules in the solar spectrum, Mem. soc. roy. sci. Liege 18, 21-230 (1957). Brown, B., and Hooper, E. C, Jr., Plastic phosphor matrix for fast -neutron detection, Nucleonics 16, 96 (April 1958). Brown, F. P., and Pelander, C. E., Tough problems solved with tricky tooling, Machinery 64, No. 1, 149-156 (Sept. 1957). Brown, F. H., Central Radio Propagation Laboratory, Signal 12, No. 4 (Dec. 1957). Bunch, M. D., and Powell, R. L., Calibration of thermocouples at low temperatures,

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135
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137
Patents

(The following U. S. Patents have been granted to NBS inventors; assigned to the United States of America, as represented by the Secretary of the Department noted in parentheses.)

Ainsworth, Ernest F., No. 2,827,623, March 18, 1958. Magnetic tape inscriber-outscriher (Commerce).

Breckenridge, Robert G., and Oshinsky, William, No. 2,793,275, May 21, 1957. Photoconductive cell (Army).

Forman, Ralph, and Breckenridge, Robert G., No. 2,828,396, March 25, 1958. Magnetoresistive device (Commerce).

Gilford, Saul R., No. 2,827,040, March 18, 1958. Automatic sphygmomanometer

(Commerce).

Gilliland, Theodore R., No. 2,824,218, February 18, 1958. Automatic radio control for clocks (Commerce).

Greenspan, Martin, and Tscheigg, Carroll E., No. 2,796,522, June 18, 1957. Crystalcontrolled relaxation oscillator (Commerce).

Haworth, Leland J., No. 2,804,613, August 27, 1957. Ship centered P. P. I. (Navy).

Hermach, Francis L., No. 2,805,394, September 3, 1957. Alternating current volt- ammeters (Commerce).

Hudson, Donald C. (Col., U. S. Army) and Kumpula, John W., No. 2,798,958, July 9, 1957. Apparatus for producing radiographs within a subject (Army).

Isbell, Horace S., No. 2,791,492, May 7, 1957. Apparatus for introducing alkali metal

into closed systems (Commerce).

Isbell, Horace S., and Schaffer, Robert, No. 2,796,416, June 18, 1957. Process of pre- paring maltobionolactone (Commerce).

Joseph, Horace M., Selgin, Paul J., Soler, Anton, and Stansbury, Carroll, No. 2,827,167, March 18, 1958. Currency counters (Commerce).

Kaufman, Joseph, and Skenes, Clarence P., No. 2,809,004, October 8, 1957. Holders

for electronic components (Army).

Kuder, Milton L., Palasky, Ervin C, Gilford, Saul R., and Greenough, Maurice L., No. 2,826,079, March 11, 1958. Automatic coin weighing machine (Commerce).

Levedahl, William J., No. 2,821,856, February 4, 1958. Rapid gas sampling valve (Commerce).

Miklofsky, Haaren A., No. 2,821,280, January 28, 1958. Feed mechanism (Navy).

Nimeroff, Isadore, and Wilson, Samuel W., No. 2,802,390, August 13, 1957. Smoke

colorimeter (Army).

Rabinow, Jacob, No. 2,795,705, June 11, 1957. Optical coincidence devices (Commerce) . Reaves, John H., No. 2,804,606, August 27, 1957. Pulse height analyzer system (Commerce).

Reggia, Frank, No. 2,798,207, July 2, 1957. Magnetic microwave attenuators (Commerce).

Rotkin, Israel, No. 2,806,155, September 10, 1957. Piezoelectric crystal traveling- wave transducer (Commerce).

Seal, Robert K-F., No. 2,787,735, April 2, 1957. Support and housing for electronic

circuits (Navy).

Seal, Robert K-F., No. 2,820,900, January 21, 1958. Magnetron overload protection

circuit (Navy).

Sorrels, John R., No. 2,817,073, December 17, 1957. Multichannel tape system of

storage (Commerce).

Sorrels, John R., No. 2,819,940, January 14, 1958. Drive controls for magnetic re- corder-reproducer (Commerce).

Thompson, Moody C., Jr., No. 2,817,759, December 24, 1957. Crystal stabilized pulse-pair generator (Commerce).

Walsh, David A., Projector, Theodore H., and Mullis, William F., No. 2,805,357, September 3, 1957. Obturator probe for control of carbon arc lights (Navy).

White, John E., No. 2,793,314, May 21, 1957. Long-life gas filled tubes (Commerce).

White, Hobart S., No. 2,824,060, February 18, 1958. Bearing compositions containing

polytetrafluoroethylene and polytrifluorochloroethylene (Navy).

Willis, Edward A., Jr., No. 2,805,898, September 10, 1957. Fluid current conveyer for

fragile articles (Navy).

Yates, Wilfred A., and Davidson, Martin, No. 2,796,756, June 25, 1957. Vibration

calibrator (Navy).

(The following U. S. Patents have been granted to NBS inventors; licensed to the United States of America, as represented by the Secretary of the Department noted in parentheses.)

Kovasznay, Leslie S. G., No. 2,817,787, December 24, 1957. Cathode ray sweeps (Commerce).

138 U. S. GOVERNMENT PRINTING OFFICE: 1959