bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cyclic Stress-Strain Behavior of Two Alloys at High Temperature
Authors: Jaske CE , Mindlin H , Perrin JS 
Published: March 2009

The cyclic stress-strain curve is useful in the design of structural components that are subjected to cyclic plastic deformation. Since the incremental step test has been used successfully to approximate cyclic stress-strain curves of metals at room temperature, the objective of this study is to evaluate its usefulness in describing the cyclic deformation behavior of two alloys at elevated temperature.
Constant strain rate incremental step tests were conducted on nickel-iron-chromium Alloy 800 and Type 304 austenitic stainless steel in air at temperatures between 70 and 1400 F. This experimental technique provided a useful method of determining cyclic stress-strain curves for these two alloys over that temperature range. Alloy 800 cyclically hardened by factors between 2 and 5, with a maximum amount of hardening at 1200 F. Type 304 stainless steel cyclically hardened by factors between 2 and 3, with a maximum amount of cyclic hardening at 1000 F. Strain rate and maximum strain range were shown to influence cyclic hardening of the Type 304 stainless steel at both 1000 and 1200 F. Results indicated that the cyclic stress-strain curve obtained from an incremental step test is most useful for estimating the cyclic stress-strain response of a material under variable-amplitude loading.
Characterization Of Semiconductor X-ray Energy Spectrometers
Authors: Walter FJ 
Published: March 2009

The important performance parameters of a semiconductor X-ray energy spectrometer and the standardized techniques for measuring and documenting most of the related specifications are described.
The strong coupling between performance parameters such as energy resolution, detector size (efficiency), count-rate capability, and general spectral integrity (tailing, etc.) is detailed. In particular, the conflict between the need to improve energy resolution by increasing the amplifier shaping time constants (that is, minimizing field-effect transistor noise) and the need to improve count-rate capability by decreasing amplifier pulse shaping time constants are examined thoroughly.
Since, as is shown, most performance parameters can be improved at the expense of other characteristics, the importance of providing enough test data to determine the trade-off cost involved in optimizing a particular variable is emphasized.
Role of Multichannel Analyzer in Data Handling
Authors: Williams G 
Published: March 2009

The multichannel analyzer role in X-ray spectrometer analysis has been taking on an ever increasing importance. Complete energy spectra observations are now possible from a single scan of a specimen with electron microscope.
The scope of this paper will be to interpret these spectral data in terms of accuracy, parameters, and usefulness to the X-ray spectrometer user. A set of general specifications will be outlined for the multichannel analyzer to cope with the ever changing requirements of the user and developments of the manufacturer.
With this aid it is the hope that the users of the multichannel analyzers will be able to incorporate units in their system that will perform the present and future functions of their applications.
Results of Cooperative Test Series on Asphalts from the Zaca-Wigmore Experimental Project
Authors: Skog J 
Published: March 2009

The Zaca-Wigmore Experimental Asphalt Project was constructed during 1954–1955 and involved 16 individual test sections and 10 different asphalts. During the construction of the pavement 16 individual barrel samples of asphalt were obtained. Each sample represented the asphalt placed in each test section.
The barrels were carefully heated and separated into 1-gal samples. These samples were sent to 9 laboratories for testing. Later four other laboratories also performed the required test schedule.
The values for the Pensky-Martens closed flash, Cleveland open cup flash, penetration at 77 F and 39.2 F, Saybolt Furol viscosity at 275 F, and standard loss at 325 F tests were determined in duplicate by each laboratory. Also certain of the laboratories performed the thin film test.
A statistical analysis of the results is presented together with a discussion on the influence of the source of the asphalt on the accuracy of the tests.
A Study of the Strength Characteristics of Marine Sediments Utilizing a Submersible
Authors: Inderbitzen AL , Simpson F 
Published: March 2009

One of the tasks of the Lockheed Missiles and Space Company's submersible Deep Quest has been to obtain detailed information on the strength characteristics of the sea floor. Continuing projects, carried out with a corer and a vane shear machine mounted on the submersible, are a comparison of in-place and laboratory vane shear strength values and an investigation of the lateral and vertical variability of in-place shear strength. The area being investigated for these projects is approximately 13 nautical miles southwest of San Diego, Calif., on the floor of the San Diego Trough at a depth of 4050 ft.
Because the projects are still incomplete, no definitive conclusions can be made. However, initial results indicate inconsistencies in the difference between in-place and laboratory vane shear strength values. Lateral variability between in-place vane shear strength measurements does not appear to be related to distance between test locations. Vertical variability in in-place vane shear strength values appears to decrease with depth into the sediment.
Fatigue of Asphalt Concrete Mixtures—Summary of Existing Information
Authors: Epps JA , Monismith CL 
Published: March 2009

In order that considerations for fatigue distress of the asphalt concrete may be incorporated into pavement design procedures, it is necessary that definitive information on the fatigue behavior of asphalt concrete mixtures be determined. Data are presented based on a review of the literature as well as our research, which illustrate the effects of a number of mixture variables on fatigue response and include an indication of the influence of: mixture stiffness, air void content, aggregate gradation, aggregate type, asphalt content, and asphalt type.
A literature review indicates the variation of air void content, aggregate gradation, and asphalt content to be expected on typical construction projects. This information together with the fatigue data presented previously allows the engineer to assess the relative importance of these mixture variables on predicting the performance of pavements. Asphalt content and test temperature appear to be more critical than the variation associated with aggregate gradation, asphalt hardness, and air void content.
Effect of Geometric Characteristics of Aggregates on the Fatigue Response of Bituminous Paving Mixtures
Authors: Huang EY , Grisham DA 
Published: March 2009

This paper presents the results of a laboratory study concerning the effects of the geometric characteristics of aggregates on the fatigue response of bituminous paving mixtures with both asphalt content and percentage of air voids constant. Three coarse aggregates and two fine aggregates, representing both natural and crushed materials were used. The geometric characteristics of these materials were determined by the particle index test for positive, quantitative identification.
The aggregate materials were combined to form three different gradations, and mixed with 6 percent (by weight) of an 85–100 penetration grade asphalt cement. The fatigue response of the various mixtures was determined by subjecting beam specimens to reversed bending at 3 constant stress amplitudes. The test program was designed according to the scheme of a factorial experiment and the data were analyzed in terms of the variances of the factors involved.
The results of the investigation show that the fatigue life of the mixtures increased with the value of the particle index of the fine aggregate. The effect of the fine aggregate was the same for all levels of the applied stress, within chance variation as measured by experimental error. The fatigue behavior of the mixtures tested was not significantly affected by the geometric characteristics of the coarse aggregate, nor was it affected by the gradation of the aggregates in these mixtures.
The J Integral as a Fracture Criterion
Authors: Begley JA , Landes JD 
Published: March 2009

The path independent J integral, as formulated by Rice, can be viewed as a parameter which is an average measure of the crack tip elastic-plastic field. This together with the fact that J can be evaluated experimentally, makes a critical J value an attractive elastic-plastic fracture criterion. The JIc fracture criterion refers to crack initiation under plane strain conditions from essentially elastic to fully plastic behavior.
Experiments supporting the validity of a JIc fracture criterion are presented in this paper. Values of the J integral were determined experimentally for two steel alloys, one of low and the other of intermediate strength. A review is given of the analytic support for the JIc fracture criterion. The range of applicability of the JIc concept, its limitations, and its advantages are also discussed.
Calcium-45-Tagged Clay as Detergency Test Soil
Authors: Hensley JW , Inks CG 
Published: March 2009

Lack of progress in reaching any general agreement on standard laboratory tests for laundry detergency performance may be related to the general use of carbon blacks as standard soils and limitations on measurement methods. Availability of radioisotopes and sensitive methods of measurement facilitate investigations with other soil materials more similar to those encountered in practice.
Some investigations have been carried out with a test soil consisting of calcium-45-tagged clay dispersed in lubricating oil and applied to cotton swatches. This soil has been employed in a miniature laboratory wash apparatus to evaluate soil removal and redeposition properties of detergents. Data are given on precision of the test method and effects on evaluations of certain test variables. Employing various detergent compositions as well as commercial laundry products, comparisons have been made between evaluations with the oily tagged clay and a conventional carbon black soil. Pronounced contradictions were found in relative evaluations with the two methods, particularly with regard to the effect of alkalies as builders, the effectiveness of unbuilt nonionic surfactant, and the action of NaCMC in promoting whiteness retention of a built anionic surfactant. Evaluations with the tagged clay soil appear to be in better general accord with practical observations than those with carbon black soil.
Tracer Techniques for Thickness of Very Thin Vacuum-Evaporated Metal Films
Authors: Preuss LE 
Published: March 2009

The vacuum evaporation process has attained importance in the field of optical coatings, sensitization methods, printed circuitry, and similar applications. Some problems exist in the determination of condensed metal film thickness, evaporant spatial dispersion, condensand profiles, and composition. A number of assay methods, such as the microbalance system, light absorption, beta scatter, and others, may be used for measurement of condensed films which vary in thickness from less than the mono-layer to over several hundred Ångstroms. Conventional methods are not sufficiently sensitive for exceedingly thin films, but the direct tracer scheme with the tagged radioactive metal charge exhibits an experimental reach sufficient to assay even the most tenuous sensitization layers.
Determinations of dispersion patterns, condensand surface concentration, condensand profile and uniformity, binary evaporant assay, trace contaminations, and alloying may be made by the tracer scheme. Techniques and the advantages and disadvantages of the method are discussed.
This paper will be concerned exclusively with the determination of surface concentrations of the more tenuous thin films-those metal layers which fall about, or below, 100 Å in thickness. Although the technique is also applicable to films of thicknesses greater than 100 Å, the thicker condensates are accurately measurable by sundry well-established systems (1,2).2 Discussion of the direct tracer scheme will be here limited principally to those films below the 100-Å region and, in particular, to its application to the condensand at the mono-layer and even below. It is in this range that the direct tracer technique may have some useful application which will supplement and compete efficiently with the various other methods for assay of thin layers.
The method will be described principally in connection with metallic layers condensed from the evaporant produced by the vacuum distillation of certain metal charges, although the direct system is not inapplicable to other tagged layers. It is safe to predict that as the direct system of test is pursued, the distilland condensate assay will become a minor application of this test mechanism.
The incorporation of the tagged element into a film to determine surface concentration is not a unique idea (3). This, in essence, could be done each time a dry planchet is assayed. Nevertheless, the method has a distinct applicability to the vacuum distillation phenomena and to the very thin condensands associated with the evaporation of metal charge.
Observations in Testing and Use of Water-Reducing Retarders
Authors: Tuthill LH , Adams RF , Hemme JM 
Published: March 2009

Continuing work in both laboratory and field with water-reducing and set-retarding admixtures has resulted in further helpful knowledge concerning them and has added to confidence in their use on the job. Significant benefits are obtained with these admixtures in job concrete, particularly in warm weather. Through postponement of the vibration limit, cold joints are less a hazard.
Reduction in water requirement to a large extent offsets normal increases in water due to warm weather, and due to higher slumps whatever their cause. At two days and later ages, strength is increased when the dosage is not above normal. At various ages beyond the first few days, the higher strengths achieved are greater than can be ascribed to reduction in water-cement ratio. Fear of the sugar content of the admixtures is apparently unfounded; troublesome delay in hardening is more likely to be the result of gross overdosage from malfunction of a dispenser. Hence dispensing equipment must be completely reliable and its performance readily verified for each batch. Such equipment is described.
Performance of the admixtures usually varies with concrete temperature and somewhat with various cements. Expected performance should be verified in advance using job materials. Dosages and sometimes the admixture must be changed accordingly, based on such test results and job performance.
The paper discusses these matters with related test data. It also discusses practical aspects of specifications, delivery, and acceptance testing when these are appropriate.
Introduction to Producers' Papers on Water-Reducing Admixtures and Set-Retarding Admixtures for Concrete
Authors: Prior ME , Adams AB 
Published: March 2009

Water-reducing admixtures and set-retarding admixtures are defined and the functional difference between them explained. The products of the four producers are divided into four chemical classifications, (1) lignosulfonic acids and their salts; (2) modifications and derivatives of lignosulfonic acids and their salts; (3) hydroxylated carboxylic acids and their salts; (4) modifications and derivatives of hydroxylated carboxylic acids and their salts. The four papers of the producers' group are concerned only with products falling within this classification.
A brief explanation of the function and mechanism of the actions of such admixtures in portland-cement concrete is suggested and discussed as it applies to this series of papers
The final section of this paper points out the significance of the design and quality control exercised by the producers to insure the functional performance of these admixtures. Particular emphasis is placed on this portion of tin-paper because of its importance to the consumer.
Effect of Water-Reducing Admixtures and Set-Retarding Admixtures on the Properties of Plastic Concrete
Authors: Vollck CA 
Published: March 2009

Commonly used water reducers and set retarders are divided into four basic categories. The effect of materials from each of these classes on water reduc-tion, set retardation, air entrainment, bleeding, workability and unit weight of plastic concrete is discussed.
Data are presented to show the effect of normal dosage and over-dosage of the admixtures at various temperatures. Influence of type and brand of cement, air entraining agents, and other admixtures on properties of plastic concrete is shown.
Application and dosage of the admixtures are given. Qualities of plastic concrete containing water reducers or set retarders that may be used to the advantage of the engineer who is seeking to solve a particular problem in the con-struction of a project are discussed.
Water-Reducing Admixtures and Set-Retarding Ad-Mixtures for Concrete: Uses; Specifications; Research Objectives
Authors: Mielenz RC 
Published: March 2009

When properly selected and proportioned, water-reducing admixtures and set-retarding admixtures (1) permit control of certain properties of fresh or hardened concrete, (2) aid in producing concrete meeting requirements of specifications when plain air-entrained concrete will not meet these requirements, (3) decrease costs of concrete and of concreting operations, and (4) permit use of design and construction practices not otherwise feasible.
Water-reducing admixtures and set-retarding admixtures should be purchased under specifications which assure uniformity, development in concrete of satisfactory qualities for the intended use, and freedom from deleterious qualities which may adversely affect significant properties of the concrete.
Major producers of these admixtures are engaged actively in basic and developmental research to improve their performance and expand their application.
Reactor Monitoring by Calorimetry
Authors: Hall KL , Klaver RF , Carroll JG , Bolt RO 
Published: March 2009

Experience with monitoring mixed radiation fields in nuclear reactors is described. Dose rates were measured by the radiation-produced heat in simple calorimeters constructed for this purpose. Principles of construction are reviewed for two types of instruments. Accuracies of about 10 per cent are estimated.
One type of calorimeter measured the total reactor radiation. This device embodied a graphite radiation absorber suspended within a hollow cylinder. Heat flowed radially to the wall of the cylinder. Four units of this type were operated in the Materials Testing Reactor.
The other type of instrument measured only the gamma portion of the reactor radiation. Neutron sensitivity was minimized by using lead as the absorber. Heat flowed axially along the lead rod to a heat sink. Three versions were built in evolving the final model which was used to determine gamma heat in the Brookhaven graphite reactor.
Dosimetry Nomenclature in the United States
Authors: Tschaeche AN 
Published: March 2009

The purpose of this paper is to present briefly the history of dosimetry, to describe the work done in the field of dosimetric systems and nomenclature by five national and one international committee, to present the current nomenclature attendant to material dosimetry, and to point out some of the current problems in the field.
The terms discussed are: absorbed dose, dosimetry, carbon dose, cadmium ratio, exposure dose, and neutron energy ranges. A new definition is suggested for absorbed dose. The concept of reference dose is discussed and defined.
The national committees concerned with nuclear technology are: (1) Aircraft Nuclear Propulsion Advisory Committee for Nuclear Measurements and Standards, (2) the National Research Council's Subcommittee on High Level Dosimetry, (3) the ASTM Joint Subcommittee, of Committees D-9 and D-20, on Radiation Effects to Plastics and Electrical Insulating Materials, (4) the ASTM Task Groups on Dosimetry, of Committee E-10 on Radioisotopes and Radiation Effects, (5) the Nuclear Standards Board's Subcommittee on Nuclear Terms, and (6) the International Commission on Radiological Units and Measurements.
The conclusions derived from the discussion of the current state of material dosimetry nomenclature are that confusion exists in the field but that the nature of the confusion is recognized and work is being done to remedy the situation by establishing generally accepted nomenclature and methods for material dosimetry.
Effects of Gamma Radiation on Some Electrical Properties of TFE-Fluorocarbon Plastics
Authors: Loy WE 
Published: March 2009

The investigation reported herein included the measurements of several dielectric properties of TFE-fluorocarbon (Teflon) plastics before, during, and after gamma irradiation by a cobalt-60 source.
Postirradiation measurements of dielectric constant of 32- and 125-mil specimens, irradiated to a dose of 5.7 × 10 7 r, indicated no change from the preirradiation values. Dielectric strengths of 3-, 5-, and 11-mil specimens, irradiated to a dose of 5.7 × 10 7 r, did not change significantly from the preirradiation values.
Volume resistivity of specimens irradiated at dose rates ranging from 3 × 10- 2 r per hr to 1.85 × 10 5 r per hr decreased very rapidly during irradiation. After approximately 20 hr resistivity reached a constant value which was at least a factor of 10 3 below the preirradiation value. Results indicate that the resistivity during irradiation is an inverse function of dose rate and specimen thickness.
After the removal of -4- and 8-mil specimens from the irradiation field, resistivity increased steadily toward the preirradiation value. The postirradiation resistivity of 250-mil specimens increased exponentially for approximately 8 hr after which a gradual decrease was observed for several hundred hours. Post irradiation values of resistivity indicate a dependence on the dose to which a specimen was irradiated.