bluuebunny/crossref_metadata_2025 huggingface dataset:
Measurement of Corona Discharge Behavior at Low Pressure and Vacuum
Authors: Dakin T. W. , Works C. N.
Published: September 2009

The significance of the reduced electrical strength of low pressure air gaps near the Paschen's minimum is considered in relation to the proper operation of electrical systems in high altitude and space vehicles. Experiments are described which illustrate the occurrence and magnitude of partial discharges (corona) in air gaps between insulator and metal surfaces at low pressure and vacuum. The magnitude of the corona pulses observed with alternating voltages varied with pressure, being relatively small at atmospheric pressures and at pressures of about 10−1 torr where glow discharges occurred; the corona pulses were considerably larger for intermediate pressures and for pressures less than 10−1 torr. Although the pulse magnitude is low in the glow discharge region, considerable integrated charge may be transferred in this pressure region. Calculation of the pulse charge magnitudes indicated that the surface area discharged per pulse at low pressure is at least one third to one half of the total available area. The characteristics of corona discharges arising from direct voltages applied to low pressure gaps are also considered.
Parameters Affecting Dielectric Materials for Space Applications
Authors: Long W. G.
Published: September 2009

The dielectric properties of inorganic materials above 600 F are extremely sensitive to minor amounts of surface contamination. The contamination can cause effects which appear as degradation of insulation resistance. Sources of this contamination include fingerprints, vacuum grease, machine oil, organic binders, vacuum pumping oils, and volatile elements from metals. Careful selection of materials and rigid adherence to cleanliness techniques are required to evaluate dielectric materials correctly at high temperatures in vacuum. Pressure, radiation, and time have a negligible effect on the properties of inorganic insulations in clean vacuum conditions.
In Situ Dielectric Property Measurements in Simulated Space Environments
Authors: Escoffery C. A.
Published: September 2009

Three methods that we are using to make in situ measurements of complex permittivity over a broad frequency range are discussed along with some test results. The methods would appear to be suitable not only for experiments in simulated space environments, but also for outer space, in “space dielectrometers” suitably instrumented for terrestrial readout and data reduction. At low frequencies (1 kHz), a planar capacitor technique is used with conventional null method and capacitance bridge. At microwave frequencies (9 GHz), a vacuum TE01n resonant cavity is used. At millimeter wavelengths (35 GHz), a dielectric rod technique is employed.
An Improved Hydrometer Method for Use in Fineness Determinations
Authors: Klein Alexander
Published: September 2009

This paper describes a method of test and a hydrometer with a new type of scale which have been developed for measuring the fineness of powdered materials. The hydrometer scale consists of units of surface area rather than the customary units of density. The method of test is generally similar to that usually employed when fineness determinations are made through the use of a hydrometer, but is simplified considerably.

The theory and equations on which the surface-increment scale is based are discussed. Brief methods of computation are illustrated which, while considerably more rapid than those customarily used, yield closely comparable results. Comparisons are made between results obtained by the brief methods of calculation and (1) those obtained by the more detailed hydrometer method used heretofore, and (2) those obtained through the use of the turbidimenter in accordance with the A.S.T.M. Tentative Method of Test for Fineness of Portland Cement by Means of the Turbidimeter (C 115–38 T).
The Electron Microscope in the Determination of Particle Size Characteristics
Authors: Hillier James
Published: September 2009

As early as 1900 it was known that an axially symmetric magnetic field could converge a beam of electrons, and not long after it was found possible by such means to form actual electron images of an emitting source. The work of H. Busch, published in 1926 and 1927, unified experimental results by showing that there is an analogy between the behavior of light rays and electron beams, and that the imaging action on electrons of cylindrically symmetric magnetic or electric fields is similar to that of a glass lens on light. With the possibility of electron lenses comes the possibility of producing the electron counterpart of many optical systems. Moreover, when the fact that periodicity may be associated with moving particles was verified experimentally, it was realized that the magnitude of the resulting wave would allow electron analogs to possess much greater ultimate resolving power than corresponding light systems. Thus, in 1932, Borries and Ruska were able to predict that if the beam of light in a compound microscope were replaced by an electron beam, and the optical system were replaced by corresponding electronic elements, it should be possible to construct an electron microscope, which, by virtue of the extremely small wave length of high velocity electrons, should possess an ultimate resolving power surpassing that of the light microscope by several orders of magnitude.
A New Method for Measuring the Surface Areas of Finely Divided Materials and for Determining the Size of Particles
Authors: Emmett P. H.
Published: September 2009

During the past few years a method for measuring surface areas of iron synthetic ammonia catalysts by means of low-temperature adsorption isotherms has been developed (1, 2) and found applicable to other metallic catalysts (3, 4), to a variety of nonmetallic porous adsorbents, and to finely divided nonporous solids (6). Since the method is comparatively simple and rapid in operation and appears to give reliable results, it has seemed worth while to describe it in detail in the present paper and to compare the values that it yields for surface areas and average particle size with those obtained on the same samples of finely divided solids by other entirely different types of measurement. It may be stated by way of anticipation that the results of such a comparison are so striking as to warrant the prediction that the low temperature gas adsorption method for measuring surface area and particle size will find wide application in industrial and scientific work.
Specific Surface of Pigments by Adsorption from Solution
Authors: Ewing Warren W.
Published: September 2009

The measurement of the area of the earth's surface, taking into account irregularities caused by hills, valleys, etc., could be accomplished by completely covering the surface with uniform spherical objects of known cross-sectional area. From the number of such spheres, the required area could then be computed. If spherical objects were not available, irregular, oblong objects, such as bowling pins, could be used, if they were all oriented in some particular configuration.
Some Applications of X-ray Inspection to Production Problems
Authors: McCutcheon Don M.
Published: September 2009

The problem of applying X-ray inspection to the manifold phases of War Production is of considerable general interest, and may be ascribed to two specific causes. One is the high-volume production of cast light alloys and other metals required for aircraft construction. The second is the extension of high-strength steel castings into new fields formerly dominated by forgings. Special applications and Government specifications probably also account for a considerable extension of X-ray inspection in some fields.
A Correlation of The Mechanical Properties and Radiographic Appearance of Magnesium Alloy Castings
Authors: Busk R. S.
Published: September 2009

A Method for the quantitative rating of radiographs showing porosity in magnesium base alloys is described. By varying the intensity of the viewing light with a Variac, and noting the voltage at which porosity is just visible, a scale is established for the rating of radiographs. This scale is then used to study the effect of microporosity on the tensile properties of Dowmetal H alloy in the as-cast and solution heat treated states; the tensile properties of C alloy in the as-cast, solution treated and heat treated and aged states; and the fatigue strength of C alloy in the solution heat treated state.

It is noted that C alloy will be less porous than H alloy under similar foundry conditions. But with a given amount of porosity H alloy will suffer a smaller loss of strength than C alloy. The tensile strength of both alloys falls as the amount of porosity increases, but the yield strength is unaffected until very large amounts of porosity are present. The fatigue strength of solution heat treated C alloy is affected to the same degree as is the tensile strength for a given amount of porosity.
The Gamma-Ray Radiography of Welded High Pressure Power Plant Piping
Authors: Emerson R. W.
Published: September 2009

This paper discusses the apparatus necessary, and the procedure used in the gamma-ray radiography of both circumferential and longitudinal seams in welded piping. Also discussed is the effect of size of radiant source, distance from source to film, metal thickness, and type of film on the resultant radiographic sensitivity.

An accurately drilled test block, having three series of holes of 116, 18, and 316-in. diameters, and depths of 0.010 to 0.100 in. in steps of 0.010 in., was radiographed using many combinations of source to film distance and metal thickness, using both a 25- and 100-mg. radium source. The smaller source definitely proved superior to the larger for short source-to-film distances but offered little if any advantage as the source-to-film distance increased beyond 6 in.

Two circumferential test pipe welds were made in which many defects, common to welded piping, were purposely made. These welds were first radiographed and then sectioned in many places, polished and etched and used to check the actual defect with the radiograph.

Two types of penetrameters were placed on both the source side and film side of the pipe welds. It is the author's opinion that there is little if any practical difference in the results obtained with the penetrameters in the two positions (at least for wall thickness up to 1.5 in.). It is agreed, however, that penetrameter detail is slightly better when the pentrameters are placed on the film side, which of course does not give an absolutely true picture of the detail of a defect comparable to the size of the penetrameter holes which is close to the root of the weld.

Also discussed and illustrated are a few of the various types of piping radiography encountered in the piping industry.
X-Ray Film Evaluation
Authors: Danford Vance
Published: September 2009

To use and improve the recording medium of industrial radiography more effectively, it is necessary to evaluate the characteristics of such material quantitatively.

This paper describes methods that have been worked out for interpreting the results of controlled X-ray exposures. The results are best shown and explained in graphical form.
Chemical Changes in Elastomers and Antioxidants During Aging
Authors: Cole J. O.
Published: September 2009

The marked changes in physical properties of elastomers which occur during aging as a result of the combined effect of heat, light, oxygen, and ozone are well known. Until recently, however, the nature of the chemical changes that occur during aging has been almost unknown. Some insight into the nature of these chemical reactions has been obtained during the last decade. It is the object of this paper to summarize the present status of knowledge concerning the chemical changes that occur in elastomers and antioxidants during aging. Only chemical changes occurring during thermal or photochemical oxidation will be considered.
Metal Powder Particle Size Determination
Authors: Seelig R. P.
Published: September 2009

A study was made in an effort to survey and classify the most important methods for particle size measurement. A comparison was made of the various types of apparatus on the basis of particle size range, operator skill, first cost, time required for determination, and other factors of usefulness. The following is a greatly condensed version of a report resulting from this study.
Variables Affecting the Thermal Stability of Three Titanium Alloys
Authors: Schwartzberg F R , Williams D N , Jaffee R I
Published: September 2009

The effects of variations in stress, strain, time, and temperature during thermal exposure on the tendency toward thermal instability in Ti-2Mo-2Cr-2Fe, Ti-6Al-4V, and Ti-4Al-4Mn alloys were investigated. None of the three alloys, which were vacuum annealed and given a stabilizing heat treatment before exposure, showed evidence of instability over a wide range of exposure conditions. Tests showed that a contaminated surface skin could lead to some embrittlement in Ti-2Mo-2Cr-2Fe but not in Ti-6Al-4V or Ti-4Al-4Mn. Tests on Ti-2Mo-2Cr-2Fe at four hydrogen levels resulted in the observation of embrittlement at the two higher levels—210 ppm and 330 ppm—after thermal exposure. However, tests at both slow and fast tension speeds showed that the embrittlement was due to an increase in the hydrogen-induced strain rate sensitivity and was not structural embrittlement. On the basis of these results, it can be concluded that titanium alloys are less unstable under thermal exposure than previously published data would indicate.
The Effect of Temperature on the Uniform Elongation of Titanium Alloys
Authors: Holden F C , Ogden H R , Jaffee R I
Published: September 2009

The limits of uniform elongation were measured for typical alpha, alpha-beta, and beta titanium alloys. Each alloy was studied in three microstructural conditions over a temperature range from −75 to 300 C (−103 to 570 F).

Highest uniform elongation was obtained for commercial titanium (alpha), whereas that for the beta-quenched 7.5 Cr, 7.5 Mo titanium alloy was low. The presence of massive alpha in the alpha-beta alloys increases their uniform elongation.

The dependence of uniform elongation on temperature is marked, particularly in the two-phase alloys. Maximum values were obtained at about 200 C (392 F).

Measurements of uniform elongation from residual strain agree well with values of δmax; the values of the flow exponent (from the flow equation, σ = Bδn) are consistently higher.
The Corrosion and Ignition of Titanium in Fuming Nitric Acid
Authors: Rittenhouse J B
Published: September 2009

The use of titanium in missile and aircraft components to extend their range and speed depends upon the high strength-to-weight ratio and the high yield-to-ultimate-strength ratio of the material. Table I shows some of these properties obtained from the titanium suppliers' literature and from the American Society for Metals Metals Handbook (1948). For a light metal, titanium has a high melting point (3020 F, 1660 C), which would lead one to expect good high-temperature properties with the consequent possibility of replacing strategic chromium- and nickel-bearing alloys with titanium. However, the yield and ultimate strengths of titanium decrease rapidly above 800 F (430 C). Furthermore, the irreversible absorption of oxygen and nitrogen from the air at temperatures above 1200 F (650 C) causes embrittlement. These factors limit the high-temperature application of the material.
Unalloyed Titanium Sheet is Improving
Authors: Barry H H , Schapiro L
Published: September 2009

A titanium industry was born and raised in the past ten years largely by the efforts of the Defense Department in supporting work to overcome manufacturing deficiencies, in supporting work to improve engineering properties, and in urging consumers to greater usage. In some quarters consumer hesitancy has resulted from reputed nonuniformity in the properties of the material. Since the Douglas Aircraft Co. has now used 13,500 sheets of one titanium grade and has tested 10,000 of these sheets, it seems appropriate to report the results of these tests and indicate the degree of improvement accomplished by the industry.
How Statistical Techniques Helped Achieve Better Uniformity in Unalloyed Titanium
Authors: Smith C R
Published: September 2009

Titanium production and sales in 1953 were reaching a point where the titanium industry had to take a good look at its major problem—the lack of uniformity in mill products. If high-geared production were to be realized in the next few years, three components of the uniformity problem had to be resolved—a need for (1) more and better qualitative and quantitative testing, (2) more correlations of test properties, and (3) more realistic and workable specifications.
Development of Standardized Specimen Preparation and Testing Techniques for Unalloyed Titanium Sheet
Authors: Folkman R L , Schussler M
Published: September 2009

In order to obtain mechanical property test ratings which would accurately characterize different lots of titanium sponge, the specimen preparation and testing techniques for wrought unalloyed sheet samples were studied. The effects of melting methods on the composition and properties of small test ingots were investigated. Data were obtained to illustrate the effect on mechanical properties of processing variables from sheet bar preparation to finishing practices for hot-rolled and annealed test samples. The influence of some mechanical test variables on resulting properties is shown.

From these studies, standardized procedures have been evolved which form the basis for specimen preparation and testing techniques used for titanium evaluation work.
Self-Limitation of Radiation Effects on Graphite
Authors: Carter Robert L.
Published: September 2009

A microscopic model accounting for radiation effects in graphite exists, in which primary, secondary and tertiary displacements are produced with characteristic threshold energies. Annealing may occur by means of a combined nucleation and diffusion process, which at graphitization temperatures results in the complete recovery from the effects. Correlation with the observed changes in physical properties is satisfactory.

Changes with time in the spatial distribution of disturbed regions in a graphite moderator exhibiting radiation damage tend toward a steady state condition. The achievement of such a state for geometries of practical importance is discussed by example in the light of data on change of physical properties with flux, temperature, and time.
A Summary of the Effect of Radiation on Some Plastics and Elastomers
Authors: Sisman O. , Bopp C. D.
Published: September 2009

As a result of the absorption of high-energy radiation, organic solids undergo rather complicated chemical reactions which are not yet fully understood in even the most simple polymers. Two general classes of reactions have been recognized, however, which can explain most of the changes that are observed in the physical properties of plastics and elastomers. The reactions are called cleavage or scission and crosslinking. The crosslinking reaction results in the binding together of the molecules of a polymer into a network structure such as is found in a gel. The cleavage reaction, as the name implies, breaks down the long polymer chains into smaller fragments.
The Problem of Establishing Specifications for Irradiated Organic Materials
Authors: Sisman O.
Published: September 2009

Unlike metals and most inorganic substances, organic materials are affected by all types of high-energy radiation. Because of this, the problem of establishing specifications and test procedures is not restricted to reactor use but is present whenever these materials are in a radiation field, such as processing plants for radioactive materials, storage of radioactive materials, hot cells, accelerators, etc. Nevertheless, reactors are our most important source of radiation, and the most complicated, and if we understand what happens in a reactor we will, for most engineering purposes, know what to expect from other sources of radiation. This discussion will, therefore. deal primarily with reactor radiation.
Absolute and Differential Dilatometry for Measurement of Unrestrained Shrinkage on Resin Curing
Authors: Rosen Bernard , Fornof Adam E.
Published: September 2009

Techniques employed for the dilatometric measurement of unrestrained volume shrinkage of a curing or cured resin are reported. The salient roles of the restrainment of reacting resins are also discussed. A versatile apparatus is described which can be used for either absolute or differential determinations. The dilatometers were equipped with a novel “net-strain balance” to detect a characteristic degree of hardening during the curing cycle. A supplementary test tube approach also was employed concurrently for this same purpose. The instruments were three-part assemblies which included: measuring tube, sample or control compartment, and glass bulb. They employed an oil column and have been found to be applicable at 200 C while thermally cycling without fatigue or significant hysteresis. The absolute method gave only the net unrestrained resin shrinkage; the more sophisticated differential approach, when combined with the absolute measurements, offered a good approximation of the complete kinetics of resin shrinkage and other properties during the curing cycle itself. The absolute technique was precise to ±0.26 per cent; although the differential approach offered a better reproducibility, difficulties were encountered in some details of the interpretation of data. The two experimental approaches tended to supplement each other and, when coupled with the concurrent evaluation of the resin's texture, they offered extremely valuable information otherwise unobtainable by present dilatometric methods.
Compression Testing of NOL Rings
Authors: Elkin Robert A.
Published: September 2009

The expanding need for structures that can be used in compression, or for both tensile and compressive loading applications, requires methods for determining the properties of filament-wound structures. Although much work has already been done in the area of tension, very little is known about the compressive testing methods and compressive properties of such structures.

This paper describes test fixtures for determining the compressive properties of unidirectional glass roving reinforced plastics. The first of these fixtures is quite simple and inexpensive and provides an excellent screening test, with good qualitative results, for a large number of specimens. The buckling problem associated with any compression test is discussed and the methods of circumventing it in these test fixtures are described.

Ring thickness and rate of loading, and their effects upon the test results, are discussed. Data presented show that the role played by the resin in a filament-wound composite structure is much greater when the structure is loaded in compression than when the loading is of a tensile nature. The compressive mode of failure is discussed.
Compressive Strength of Parallel Filament-reinforced Plastics: Development of a New Test Method
Authors: Fried N. , Winans R. R.
Published: September 2009

Investigations were conducted to obtain a valid measure of the compressive strength of filament-wound plastic composites. Working with flat, unidirectional specimens, and commencing with standard methods of evaluation, a series of tests was conducted with variations in procedure and specimen geometry. Resulting compressive strength values were relatively low and, on considering the mode of failure, it was concluded that this property could not be determined by a method in which load is applied directly to the specimen ends.

Consequently a new method was developed in which load is applied to the faces of a specimen through wedge grips. Using this technique and a specimen of a particular geometry, the compressive strength of a unidirectional material with a glass content of 85 weight per cent was determined to be 167,500 psi. Preliminary investigations with wound rings have provided some indication of the validity of this value.
Research on Wire-Wound Composite Materials
Authors: McGarry F. J. , Marshall D. W.
Published: September 2009

Small-diameter (0.003 in.) steel wire with various types of metallic surfaces and exhibiting a tensile strength approximating 600,000 psi is now available in commercial quantities. The material can be handled conveniently and without damage, and can be economically wound into a variety of container shapes. Exploring such applications the following combinations have been fabricated: wire-epoxy, wire-polyethylene, wire-polypropylene, and glass fibers — epoxy. (The glass fiber construction serves as a basis for comparison.) Single reinforcement resin specimens were used to perfect surface treatments which gave greatest adhesion; plate laminates were then prepared to provide flat test specimens for tensile and flexural measurement. The Naval Ordnance Laboratory (NOL) split ring test has also been used as well as internal pressurization of helically wound thin-walled tubes. Progress to date indicates that good utilization of the inherent wire strength is possible in filament-wound constructions.
Single-End Glass Yarn Tension Test
Authors: Pirzadeh Nozar , Kennedy Paul B.
Published: September 2009

Current tests for evaluating glass reinforcements for filament winding are either unwieldly, inaccurate, or include many of the effects of processing the specimen. Development of a test method for evaluating single-end glass yarn which would be relatively simple, accurate, and eliminate the effects of many of the processing variables common with other types of specimens was undertaken.

Tests of yarn impregnated with an epoxy resin were found to be more meaningful than tests of unimpregnated yarn and were used throughout the work. The major process conditions of initial cure temperature of the impregnant, tension during cure, resin content, specimen length, and twist of the yarn as received, were found to have little or no effect on the results. The method is sensitive to the elastic moduli and elongation properties of resins, with more flexible, higher elongation materials giving higher strengths. Glass stresses increased with increasing strain rates. Different glass materials affect the results as expected with conventional E glass giving average stresses as high as 386,000 psi and an experimental glass giving an average of 640,000 psi with the same resin system. A direct comparison with a conventional split-disk hoop tension test shows the single-end test to give higher glass stresses but the hoop test appears to have a lower within-group variability.

The test method presented meets the objectives of simplicity and accuracy and appears suitable for quality control and evaluation purposes.
A Laboratory Scale Filament Winding System to Produce Pressure Vessels Rapidly and Simply
Authors: Outwater John O.
Published: September 2009

In order to determine the effects of variables on the performance of pressure vessels it is necessary to fabricate pressure vessels rapidly and accurately so that statistical data can be obtained. A filament winding system has been developed to make 8-in. diameter vessels with about 2 man-hours of labor each. These vessels can be tested on an Instron Tester.
Photoelastic Studies of Filament-Wound Pressure Vessels
Authors: Eshbaugh Robert
Published: September 2009

Filament-wound pressure vessels are being studied at the Naval Ordnance Laboratory by the Zandman photostress technique. With this technique, a thinlayer of special plastic is adhered to the surface to be studied, the interface having been made reflective. As the surface strains of the vessel are transmitted to the plastic, the plastic exhibits a birefringence which is proportional to the difference in principal strains. With the use of a polariscope, the direction and magnitude of the principal strains may be measured over the coated area. Many elements of the filament winding process which affect stress distribution in the vessel may be studied using this technique.
Proposed Method of Test for Interlaminar Shear Properties of Sizings and Binders for Secondary Reinforcements Using a Polar-Cut Ovaloidal Specimen
Authors: Perry H. A.
Published: September 2009

The use of secondary reinforcements around off axis ports in rocket motor ngs or around openings in other filament-wound structures where the cipal reinforcements must be cut poses special problems in the testing of ngs and resinous binders. Methods of test must be developed for determining ability of the sizing and binder to transfer loads between the principal secondary reinforcements under conditions resembling those encountered he vicinity of ports or openings, accompanied by the problems of determining applicability and significance of data obtained from these tests to the selection or ptance of these materials.
ASTM Task Group Round-Robin Testing
Authors: William Davis J.
Published: September 2009

The ASTM Task Group on Filament Wound Materials Test Methods of Committee D-20 on Plastics of which I am chairman was created in March, 1961. The group has met several times since and I think we have accomplished a great deal in the short time we have been in existence.
Craze Cracking in Glass Filament-Wound Pressure Chambers
Authors: Rawe Richard A.
Published: September 2009

An experimental study of craze cracks in glass filament reinforced plastics was conducted in order to determine the nature and cause of the crazing phenomenon. Both visual examination and microscopic techniques were employed. Photomicrographs of cross-sections through representative craze cracks are presented. A theoretical model for the mechanism of cracking was developed on the basis of the observations made and is demonstrated schematically. The probable causes of craze cracking are three: filament migration prior to completion of the resin cure, inaccuracies in placement which may occur during winding, and crossing of one layer of filaments over others. An experiment performed in this work employing an 18-in. diameter pressure chamber indicated that craze cracking occurs, at least in part, prior to burst. Improvements in winding machine and materials are required to reduce crazing.
A Television X-ray Image Enlargement System for Non-destructive Testing of Fiber Glass Reinforced Plastic Missile Case Materials
Authors: Rhoten Merle L. , McMaster Robert C.
Published: September 2009

A unique television X-ray imaging system is described that was developed at The Ohio State University, Nondestructive Test Research Laboratory, under the sponsorship of Watertown Arsenal Laboratories. This system utilizes small-diameter (1-in.) special X-ray sensing vidicon camera tubes as a direct sensing medium for the penetrating radiation image. The resulting signal is amplified by means of a closed circuit television system, and the image presented on a 17-in. picture tube resulting in 32 × magnification. Image of good contrast and detail resolution better than 0.0005 in. is reported.
Quality Control Procedures for Rocket Motor Cases: Reinforced Plastic Versus Steel
Authors: Duvall P. F.
Published: September 2009

The problem of quality control for filament-wound reinforced plastic pressure vessels is quite unlike that encountered in the production of metallic vessels. Here, the fabricator's controls must start with the basic constituents of the final case material rather than with forged blanks of a particular alloy and they must extend to the actual process of combining the composite elements. They are currently limited in the analysis of the finished part to techniques and equipment developed for use with totally different materials.

Against this background of total differences in the quality control problem, the Allison Division of General Motors Corp. has established a series of quality control procedures to provide product reliability of reinforced-plastic rocket motor cases consistent with that being achieved with their titanium and steel counterparts in the Minuteman rocket. This paper describes the steel and reinforced plastic quality control programs currently in existence and describes a new final product quality control technique now under study for reinforced-plastic cases.
Test Methods for Filament-Wound Specimens
Authors: Yurenka S.
Published: September 2009

A systematic investigation was made of test methods for the effects of such variables as different materials, processing conditions, design considerations, and environment on the mechanical properties and behavior of filament-wound structural components. The specimens consisted of wound rings, cylinders, and cylindrical pressure vessels, and the tests included unidirectional and biaxial tension, compression, shear, and bending. The accuracy and usefulness of eight different tests are assessed and representative experimental data are presented. The specimens and testing jigs are illustrated and described.
Relationship Between Intensity of Carbon arc and Asphalt Oxidation
Authors: Wright J. R. , Campbell P. G. , Fridinger T. L.
Published: September 2009

Films of two air-blown asphalts were exposed to the carbon arc at different intensities to determine the effect of radiant energy intensity on the rate of asphalt oxidation. The oxidation rates were established by measuring the changes in infrared absorption in the carbonyl band as a function of exposure time. The intensity of the radiant energy was varied by the voltage adjustment switch on the accelerated weathering machine or by moving the samples closer to the arc. The intensity was monitored by power consumption and the incident flux by chemical dosimetry. It was found that: (1) the asphalt oxidation rate increased with the intensity of the carbon arc; (2) the radiant energy output of the accelerated weathering machine tends to level off at the higher voltage settings; and (3) at the maximum voltage setting of the accelerated weathering machine, the incident radiant flux does not equal or exceed that which can be absorbed by asphalt. Monitoring the incident radiant energy is recommended as a part of the accelerated weathering procedure for asphalt.
Composition as Related to Manufacturing and Weathering of Roofing Asphalt
Authors: Corbett L. W. , Swarbrick R. E.
Published: September 2009

Asphalt composition, as revealed by a separation technique giving paraffins plus naphthenes, three aromatic oil fractions, and asphaltenes, varies with crude oil source and with method of manufacture. This composition has a direct bearing on the asphalt's physical and chemical properties. By comparing properties of reconstituted asphalt, made with two fractions at a time, the influence of each fraction is illustrated. The influence of composition on weathering qualities of a roofing asphalt is also brought out by separately increasing the content of each aromatic oil and the paraffin plus naphthene fraction in the asphalt. Aromatic oils tend to increase weathering resistance, and the paraffins plus naphthenes have the opposite effect.
The Prediction of Coating-Grade Asphalt Weatherability from Asphaltene-Dispersibility Data
Authors: Jones T. K.
Published: September 2009

The dispersibility of the least soluble asphaltenes shows a good linear correlation with Weather-Ometer durability for coating-grade asphalts made by air blowing straight-run, blended crude oil, ferric-chloride-catalyzed residua, and oil fluxed stocks. Asphalts blown from phosphoric-acid-catalyzed residua show poor correlation.

A modification of the original procedure for titration of the xylene solutions of asphalt with n-heptane is presented. The modified method eliminates back-titrations that prove troublesome with some asphalts. Repeatability and reproducibility for these asphalts is improved over results obtained with the original procedure.
EPR Measurements of Radiation Immunization in Poly (methyl Methacrylate) by Organic Additives
Authors: Atwater H. A.
Published: September 2009

Electron paramagnetic resonance techniques were used to compare the relative radiation immunity against free-radical formation given to poly(methyl methacrylate) by the addition of various protective agents at low concentration (5%). Under irradiation by X rays and pile gamma rays, it was found that the degree of protection afforded varied rapidly with the total radiation dose.
Neutron and Neutron Spectra Contribution to Damage in Silicon F.E.T.'s
Authors: Kaufman Alvin B.
Published: September 2009

Frequently the system designer wishing to utilize semi-conductor devices in a particular radiation environment finds that the only test results available were obtained in a significantly different environment, and that circumstances beyond his control prohibit an empirical test under the new conditions (1). The problem then arises, how to successfully extrapolate to the new environment of interest. A determination of the effect of neutron and neutron spectra on silicon field effect transistors would allow the performance of such devices to be correlated from existing data, and subsequently to be extrapolated to new environments as required.
Hydraulic Fluid Closed Compartment Fire Tests
Authors: Kander K. A.
Published: September 2009

A Closed Compartment Fire Test for evaluating fire resistance of hydraulic fluids in advanced supersonic aircraft is discussed. This test simulates leakage in proximity to heated aircraft skin at temperatures up to 550°F, both with and without simultaneous electrical arcing. The response to an electrical arc (time to initiate fire), size of fire, intensity of fire, flame propagation, and duration of fire after removal of arc are observed during each test. Simulative flammability tests of this type are required, since conventional hot manifold drip and spray tests do not always predict fluid flammability within the confines of a heated, closed compartment.
A Simplified Spray-Flammability Test for Hydraulic Fluids
Authors: Rowand H. H. , Sargent L. B.
Published: September 2009

Hydraulic lines are known to rupture permitting a stream or spray of hydraulic fluid to encounter the flame of burning fuels or the surface of hot or molten metal. This is a prevalent cause of fires in many industries. High-pressure spray-flammability tests simulate this type of industrial hazard and are able to distinguish the difference in fire resistance among the various kinds of hydraulic fluids.

The available high-pressure spray tests are inconvenient to use, however, since they usually must be done outdoors where they are subject to the vagaries of the weather. If done indoors, the tests must be performed in specially assembled fireproof areas. In addition, relatively large volumes of test fluids are needed, and the high-pressure pump, motor, and auxiliary equipment can become costly.

A low-pressure spray-flammability test that can be conducted safely in a conventional laboratory hood is described. The equipment required is simple and inexpensive and only limited amounts of fluid and fuel are needed. The flame from a laboratory gasair burner serves as the source of ignition. The data obtained correlate very well with those from a conventional high-pressure spray-flammability apparatus. Results from both kinds of tests evaluating the several types of fire-resistant hydraulic fluids are presented in tabular and pictorial forms.

A variety of test conditions is not available with the new method described, but the conditions are chosen so that they simulate practical industrial situations and provide correlation with other flammability tests at a sufficient confidence level.
The Ignition of Flammable Fluids by Hot Surfaces
Authors: Goodall D. G. , Ingle R.
Published: September 2009

The full-scale fire testing of aircraft power plants has suggested that laboratory closed-vessel spontaneous ignition tests give results which are pessimistic for many practical applications. The results of a number of test programs involving specific configurations of hot and cool surfaces have indicated that, for a particular fluid, it might be possible to establish a thermal correlation which would enable the risk of ignition to be calculated at the design stage.

Tests have been carried out on two rigs, both incorporating a hot bottom plate surface onto which the test fluid was sprayed, the side walls and top plate being somewhat cooler. The first rig was a static rig in which top and bottom plate temperatures and the gap between them was varied. The effects of mixture strength, atomization, and wall materials were studied for kerosine, and the ignition temperatures for various fluids have been determined for a limited number of configurations.

The second rig consisted of a small wind tunnel in which the effect of air velocities up to 10 ft/sec and altitudes up to 20,000 ft were investigated. It is shown that air velocities up to 3 ft/sec have a large effect on spontaneous ignition temperatures.

A correlation based on gas temperature and distance from the nearest wall shows good agreement for the static and wind tunnel rigs and for closed-vessel tests of other investigations. An outline of the future program of work is given.
Survey of Techniques for the Evaluation of the Fire Resistance Properties of Aviation Hydraulic Fluids
Authors: Alan R. , Ker C.
Published: September 2009

Five types of aviation hydraulic fluid were examined — mineral, snuffer, phosphate ester, siloxane, and chlorosilicone.

Statistics show that more aircraft accidents are associated with wheel brakes than with any other components. A hot brake test simulating conditions that could develop from a fractured hydraulic pipe during braking revealed little difference in the ignitability of phosphate esters, mineral type and a snuffer fluid D.

Only one fluid, a snuffer fluid C, withstood ignition with brake heat pack temperature of 700C.

Several well known simpler laboratory techniques were used. Of these a combined high pressure spray/manifold test not only gave a reasonable degree of correlation with the hot brake test results, but also differentiated between the degree of flame propagation evidenced by these fluids.

The shape of the nozzle in the spray tests influenced results whilst fluid temperature and pressure were found to have generally little significant effect.
Factors Affecting the Formulation of Engine Oils for LP-Gas Service
Authors: Broman V. E.
Published: September 2009

The problems associated with crankcase oils for engines using liquefied petroleum gas as a fuel are largely those involving oxidation and excessive ash. Engine oils for propane or natural gas service, therefore, must be formulated to control combustion chamber deposits which may promote preignition and spark plug fouling and to resist oxidative deterioration. These requirements define an LP-Gas engine oil composition as a virtually ashless product with excellent oxidation stability. Generally, since propane/natural gas fuels produce no liquid byproducts to act as a temperature quench and, in addition, burn cleanly and completely, combustion temperatures are high.

Fuel combustion properties and other factors such as exhaust blow-by determine the performance characteristics needed by LP-Gas engine oils as: superior dispersancy for oil oxidation products, high-temperature oxidation inhibition, rust protection, antiwear and extreme pressure (load carrying) qualities, and pour-point depression.

The details of an additive system supplying these performance properties is given. The proposed formulation has Supplement I compounding and satisfactorily meets the service requirements of both automotive and high, medium, and slow speed industrial engines.
State of the Art in LP-Gas Fueling Systems and Problems for Motor Fuel, Forklift, and Recreational Vehicle Bottle Filling
Authors: Carnahan J.R. E.
Published: September 2009

Major problem areas of LP-Gas dispensing systems relate to deficiencies in existing systems, improper fuel transfer practices, customer service standards, failure to observe regulations and codes, and education and training of personnel handling transfer of LP-Gas.

The state of the art is at a point where engineering and technical deficiencies of existing dispensing systems can be corrected satisfactorily in most instances. High standards of customer service are being met by some marketers and dealers, especially those who maintain continuing education and training programs for their personnel. Requirements for satisfactory dispensing systems are clearly outlined in equipment manufacturers' technical literature and field service manuals.

The continuous, ongoing element of training is the key factor in marketers' and dealers' programs, with persistent follow-up of all critical phases of such efforts. Equipment manufacturers and industry publishers continue to provide excellent source material for the education and training of industry personnel.

It has been accepted as the joint responsibility of manufacturers, marketers, dealers, LP-Gas associations, and industry trade journals to continue established programs and to initiate new ones.

It is evident that important contributions to the state of the art in LP-Gas fueling systems will continue for the benefit of all segments of the industry in the years ahead.
LP-Gas Engines for Heavy Duty Trucks
Authors: Ingerson Howard
Published: September 2009

Diamond Reo Trucks, Inc. has been a builder and user of heavy duty LP-Gas engines for many years. During this time period, a considerable amount of experience has been acquired relating to the peculiarities of LP-Gas as an engine fuel and design details of the engines to utilize this excellent fuel.

Unfortunately, many engines that have been converted to use LP-Gas fuel have either been simple fuel system conversions, with little or no attention to mechanical details, or have been light or medium duty engines, and were never really designed for heavy duty usage.

This paper describes some of the differences of behavior of LP-Gas as an engine fuel, contrasting to gasoline, and engine design details found necessary to provide optimum engine performance and durability with LP-Gas fuel.
Application of Catalytic Converters for Exhaust Emission Control of Gaseous and Liquid Fueled Engines
Authors: Jagel K. I. , Lehmann G. J.
Published: September 2009

A survey covers the use of catalytic combustion to oxidize engine exhaust pollutants; Engelhard Minerals & Chemicals Corp.'s PTX catalytic purifier including its development and evaluation in the laboratory, bench scale data for the standard PTX catalyst, and the physical structure of the catalyst; its applications in nonautomotive areas such as floor sweepers and scrubbers, mining equipment, and pumps; automotive uses, including 1975 prototype automotive exhaust emission control systems and a retrofit fleet test of durability; and its use in lift trucks.
Industrial Fuel Oils
Authors: Hume H. V.
Published: September 2009

Man's discovery of fire, the exact date of which is lost in the dim pages of antiquity, marked one of the most significant steps forward in human progress. In the evolution of heating and lighting we are accustomed to think of petroleum and its products as a very recent contribution. As a matter of fact, however, petroleum has a very ancient history. It is quite probable that Noah caulked the seams of the Ark with natural pitch from petroleum seepages. As long as seven thousand years ago the Egyptians used asphalt in embalming. In China, several hundred years before Christ. oil was obtained in deep well drilling for salt. Pliny mentions “Maltha” and “naptha” which were known to burn freely and were used in lamps. Marco Polo described the uses of oil as an illuminant in the thirteenth century in connection with a description of Baku petroleum. Over three hundred years ago there was a thriving industry on the shores of the Caspian Sea, a district which is today one of the world's oil centers. In the seventeenth century in America missionaries reported the use of petroleum by the Indians.