bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Effects of Composition and Fineness of Cement in Accelerated Testing of Concrete
Authors: Al-Rawi RS 
Published: February 2009

Abstract
The effects of C3A content, fineness, gypsum content, C3S:C2S ratio, and alkali content of the cement on the correlation between 1-day accelerated and 28-day normal strength of concrete were investigated. The accelerated testing method used was that developed by the Institution of Civil Engineers (ICE) Accelerated Testing Committee [1]. Both C3A and alkali content did not affect the correlation between accelerated and 28-day strength. Increased fineness caused the predicted 28-day strength to be less than actual. Increased gypsum content could cause an increase in accelerated strength and at the same time a decrease in 28-day strength. The ICE correlation was not applicable when cements of low C3S:C2S ratio were used.
Some Mechanical Properties of Sintered Fiber Metal Composites
Authors: Rostoker W , Galante JO , Shen G 
Published: February 2009

Abstract
Kinked, short-length, fine wire can be molded by conventional powder metallurgy procedures and sintered to a porous composite with large proportions of interconnecting voids. This material has potential applications for implanted prosthetic systems. The material behaves in a nonlinear elastic fashion which may be approximated as two linear elastic processes. In the strain range of 0 to about 0.5 percent, the elastic modulus can be less than 1 kg/mm2. In a higher strain regime the elastic modulus is about 100 kg/mm2. A total elastic strain range of 1.5 to 4 percent is found.
Contamination Control in the Production of High-Purity Chemicals
Authors: Zief M , Horvath J 
Published: February 2009

Abstract
Contamination problems inherent in the preparation of high-purity chemicals must be recognized and controlled. Major problems such as airborne contamination, leaching from containers, and reagents for ultratrace elemental analysis are reviewed. Trace impurities contributed by electrostatic charges, filtration media, and water are discussed.
A Critical Assessment of the Cantilever Beam Method for the Determination of Dynamic Young's Modulus
Authors: Rosinger HE , Ritchie IG 
Published: February 2009

Abstract
The application of a noncontacting optical transducer for the measurement of flexural resonant frequencies and normal mode shapes of a cantilever beam is described. Results on the resonant frequencies of cantilever beams, gripped at the fixed end by a vise, are compared with the Bernoulli-Euler and Timoshenko beam theories. Although the mode shapes agree well with the theories, there are large discrepancies between the experimental variation of resonant frequency with inverse slenderness ratio and that predicted by the theories. These discrepancies are attributed to imperfect clamping. It is concluded that for accurate Young's modulus calculations from the measured resonant frequencies of cantilever beams, tests must be restricted to long slender beams. For beams which cannot be fabricated to meet this criterion, an empirical method is presented which yields Young's modulus to within ±3 percent on the specimens tested. For increased accuracy the free-free reasonant beam method should be used.
An Acoustical Emission-Damping Fatigue Study of a 17-4 PH Steel
Authors: Willertz LE , Hunter DO 
Published: February 2009

Abstract
The acoustic emissions emitted from a 17-4 PH stainless steel were monitored while the specimen was undergoing fatigue testing in the torsional mode. Below the cyclical stress sensitivity limit (CSSL) of the material no abnormal emissions were detected, while at and above CSSL emissions were detected which could be attributed to fatigue damage which resulted in failure of the specimen. This test was the first in a series which will enable us to learn more about fatigue damage in various materials.
High Cycle Fatigue Crack Propagation Rates in Copper
Authors: Nakano Y , Sandor BI 
Published: February 2009

Abstract
The crack propagation rate was studied on axially loaded specimens of oxygen-free, high conductivity copper tested in the high cycle life region. Fatigue tests were conducted under load control without a mean load. The variables of the test conditions were the engineering stress range, the average grain size, and the atmosphere (air and argon gas). The crack propagation rate during the first 80 percent of the life was determined by using an electropolishing technique. The rate was also measured after final failure of each specimen from the distances of the striations on the fracture surface observed through a scanning electron microscope. The crack propagation rate depended upon the test conditions as well as on the prior stress cycling. The crack propagation was divided into two main stages: the crack nucleation and microcrack development stage, and the crack propagation or macrocrack development stage. Argon gas atmosphere reduced the macrocrack propagation rate, but did not affect the crack nucleation and microcrack development significantly. Increasing the grain size shortened the crack nucleation stage markedly.
Design and Analysis of Corrosion Experiments for Testing Materials Exposed to Gamma Radiation
Authors: Makepeace CE 
Published: February 2009

Abstract
The scope of metallurgical engineering applied research and development of cladding and encapsulation materials has been extended during recent years beyond those materials used in core and cladding and in non-core structural nuclear applications in research and power reactors. Materials for the encapsulation of radioisotopes for medical and commercial uses must also be carefully selected for their suitability for exposure initially up to two years in the reactor followed by four or five years in service. The susceptibility to corrosion of all of these materials is a most important consideration. Conventional weight loss and potentiostatic experiments require careful design of both the physical corrosion assembly and experimental method. In this paper a controlled laboratory experiment using a 50,000-Ci gamma irradiator is used as an example to exemplify the use of Statistical Design of Corrosion Experiments.
Life Testing of Nickel-Chromium Alloys
Authors: Starr CD 
Published: February 2009

Abstract
An evaluation of the life test for 80Ni-20Cr alloys specified in ASTM B 76 has been made. It is shown that the emissivity of the wire is not constant after the pretreatment but requires about an additional four hours at the test temperature. The convection coefficient increases continuously during the life test causing more power to be dissipated by convection as the test progresses.
The small resistance change during the test is a balance between relatively large changes in both the resistivity and the dimension of the sample. A unique expression is developed that enables the change in resistivity to be determined from electrical data. Calculated decreases in chromium and in the diameter of the wire are compared to experimental values. Failure occurs after the alloy has lost about 6 percent chromium and about 10 percent of its cross-sectional area.
Experimental Determinations of the Thermal Conductivity of Fluids by Coaxial-Cylinder Apparatus
Authors: Tsvetkov OB 
Published: February 2009

Abstract
A coaxial-cylinder apparatus has been designed for steady-state and for non-steady-state measurements. The cell was calibrated by using several gases of known thermal conductivity (air, helium). The thermal conductivity of Refrigerant 12 (R 12) in the liquid and gaseous states at temperatures up to 0.95 Tcr and at pressures to 16 MPa has been determined. Erratum to this paper appears in 3(1)
Computer Optimization of Hydraulic System Pressure for Development and Qualification Testing
Authors: Goldenberg K , Collins DG 
Published: February 2009

Abstract
A computer program has been developed to optimize hydraulic pressure system selection for use in the structural testing of aeronautical vehicles. This program will select the minimal number of pressure systems, using available hydraulic cylinders, to match all the simulated flight loads which are applied during a test. Programs were written for Fortran and Advanced Basic language users of the IBM 360/67 time-sharing system or the Varian 620/i stand-alone system. Various options are present in the programs to adjust for unique testing conditions. Since the number of pressure system combinations for large-scale testing can be astronomical, this program has eliminated what was formerly a frustrating, time-consuming, and highly subjective task.
A Spectrophotometric Technique for the Fabric Analysis of Monomineralic Kaolinitic Soils
Authors: Sheeran DE , Krizek RJ 
Published: February 2009

Abstract
A technique for identifying the fabric of kaolin clay by measurement of the monochromatic light intensity emanating from the analyzer of a polarizing microscope is described and evaluated analytically and experimentally. This technique is based on the variation of light intensity with the degree of retardation in an optical compensator. Actual fabrics are simulated by super-imposing the optical properties of 2000 individual kaolinite crystals comprising hypothetical fabric models in which the individual c-crystallographic axis directions are normally distributed about a mean direction with respect to the microscope optics. The intensities are computed for models with different mean c-axis directions and degrees of fabric randomness, which is characterized by the standard deviation of the normal distribution, and these intensities serve as a reference to which experimentally obtained intensities for thin sections of kaolinitic soils with unknown fabric are compared. An appreciation of the fabric homogeneity over the area of a thin section can be obtained by use of an equal area spherical projection plot.
Waste Glass as Coarse Aggregate for Concrete
Authors: Johnston CD 
Published: February 2009

Abstract
The paper reports on the performance of 34 different concrete mixes containing glass crushed to ¾-in. (19-mm) maximum size as coarse aggregate and six reference mixes made with gravel of the same size. Two cements of alkali equivalent 0.58 and 1.13, classifiable as low and high alkali (ASTM C 150-72), in amounts ranging from 400–900 lb/yd3 (237–534 kg/m3 were used in combination with glass both with the fines removed and in the as-crushed condition. Partial cement replacement with fly ash and mixing of glass with gravel aggregate were included in an attempt to find a suitable method of overcoming the expected adverse effects of the reaction between glass and cement alkalis.
On the basis of compressive strength, flexural strength, expansion, and visible surface deterioration recorded up to an age of one year, the results show that in many cases the direct combination of glass with portland cement yields concrete which exhibits marked strength regression and excessive expansion due to alkali-aggregate reaction. The conditions under which performance is satisfactory appear to relate to limiting maximum values of cement content and alkali equivalent. Replacement of 25 to 30 percent by weight of the cement, whether low or high alkali, appears to be an effective and widely applicable method of ensuring good long-term concrete performance, although the minimum required in any given case may be related to cement composition.
Fracture of Rocket Grain Models Subjected to Cooldown: A Study of Temperature-Initiated Fractures of Two-Dimensional Rocket Grain Models
Authors: Francis EC , Deverall LI , Zitzer HJ 
Published: February 2009

Abstract
A method is presented for evaluating two-dimensional crack behavior resulting from thermal cooldown loading of rocket motor configurations in which the grain is bonded to a stiff case. The associated analytical solution used to quantitatively interpret the data is also presented. For three different grain geometries of a brittle epoxy tested, comparison was quite good between analytical predictions (using elastic fracture mechanics methods) and experimental observations. The results of this study can be applied to fracture analyses of solid propellant rocket grains and other structures containing cracks extending partially through the thicknesses of the structures.
Computer-Aided Interpretation of Stress-Strain Curves
Authors: Goodman ML , Jorgensen GJ , Wonsiewicz BC 
Published: February 2009

Abstract
A computer scheme for interpreting stress-strain curves has been developed using two basic algorithms. The first locates the initial linear portion of the curve by comparing the fit of linear and quadratic curves to the data. The second determines the intersection of the offset line with the data. The scheme was tested by comparing computer results with manual results obtained by skilled observers. Results were good: tensile strength and 0.2 percent offset yield strength showed small differences, less than 2 percent. For the modulus and yield strength at 0.01 percent offset, the differences between the various observers were more significant than the differences between the computer results and the observers. For 32 samples (95 specimens) the computer results for the modulus were generally within ±2 percent of the average of the results from four observers and within ±10 percent for the 0.01 percent yield strength. Based on these results, a standard computer program has been developed which generates graphical summaries of the mechanical properties in a form suitable for permanent records.
The Dynamic Response of Metals in Evaluating Stress Corrosion Cracking
Authors: Hochrein AA , Thiruvengadam A 
Published: February 2009

Abstract
An experimental investigation of stress corrosion cracking in metals is reproted for several alloy-corrodent systems. Internal damping measurements are made on the metals in the as-received condition and after they have been exposed to a corrosive environment. Data curves are reported for different grain sizes of 2024-T4 aluminum in a mercury-corrodent environment and for 304 stainless steel in boiling MgCl2. Considerable changes in the diffusion peaks of these alloys are observed following their exposure in a stressed state to the environment in which they are known to be susceptible to stress corrosion cracking. Corroborative tests on electrolytic copper stressed in a corroding environment of air-saturated synthetic seawater indicate no changes in its internal damping characteristics. This material is immune to stress corrosion cracking in the seawater environment.
This study is developed from the idea that metals which are susceptible to stress corrosion cracking exhibit changes in their damping properties after environmental exposure. From the experimental evidence obtained, susceptibility to stress corrosion cracking is associated with decreases in the peak amplitudes of the internal damping curves. The decrease occurs across either the thermal diffusion peak associated with the specimen thickness or with the grain size of the metal. Moreover, for alloys immune to stress corrosion cracking, it is shown that the peak amplitudes remain unchanged after environmental exposure and when compared to the same data curve for the as-received material.
From these studies it is concluded that the decreased amplitudes of the internal friction peaks indicate the susceptibility to stress corrosion cracking. This decrease results from the thermal diffusion effects associated either with the specimen thickness or with the grain size. For nonsusceptible systems, the peak amplitudes remain unchanged after environmental exposure.
The specific aluminum alloy and stainless steel are used in order to demonstrate a basic phenomenon. It should not be construed that neither aluminum alloys nor stainless steels are useful marine alloys.
Interlaboratory Evaluation of ASTM E 84-70 Tunnel Test Applied to Floor Coverings
Authors: Lee TG , Huggett C 
Published: February 2009

Abstract
Results of an interlaboratory evaluation of the American Society for Testing and Materials (ASTM) Test for Surface Burning Characteristics of Building Materials (E 84-70), involving eleven laboratoires and nine materials including four carpets, are reported. Data on flame spread, smoke, and fuel contribution were analyzed statistically to determine the reproducibility and repeatability of the test method. Selected physical characteristics of each tunnel are tabulated and compared relative to specifications in the test method. The between-laboratory coefficient of variation (reproducibility) in flame spread classification (FSC) was found to range from 7 to 29% for the four carpets and from 18 to 43% for the other materials tested. The between-laboratory coefficients of variation for smoke developed and fuel contribution ranged from 34 to 85% and from 22 to 117%, respectively, for all materials tested. The causes of higher variability in smoke and fuel contribution measurement between laboratories are not definitely known but may reasonably be attributed to variations in tunnel construction, instrumentation, and operation in different laboratories.
Spectral Energy Distributions and Aging Characteristics of Fluorescent Sunlamps and Blacklights
Authors: Mullen PA , Kinmonth RA , Searle NZ 
Published: February 2009

Abstract
The spectral energy distributions of commercially produced 20-W fluorescent sunlamps and blacklights designated for use in the revision of the American Society of Testing and Materials (ASTM) Recommended Practice for Exposure of Plastics to Fluorescent Sunlamp (D 1501-71), were measured between 250 and 600 nm at 3-nm intervals. Two types of blacklights with the same designation (F20T12B1), but with different emission characteristics, are manufactured. The decrease in emission intensity with hours of use varies with type and source of lamps. The best simulation of sunlight in the ultraviolet region below 360 nm is given by the combination of one sunlamp with one of each type of blacklight.
Finite Element Modeling of Magnetic Field/Defect Interactions
Authors: Hwang JH , Lord W 
Published: February 2009

Abstract
Defect modeling and the prediction of magnetic field/defect interactions is of importance to the further refinement of electromagnetic methods of defect detection and categorization. Finite element methods are particularly suited to the analysis of field distributions within magnetic structures having complex boundary geometries and nonlinear B-H characteristics. This paper describes operational aspects of the finite element technique and shows how such methods can be applied to the analysis of electromagnetic methods of nondestructive testing, by predicting the magnetic field distribution around a rectangular slot in the surface of a circular ferromagnetic bar carrying an axial magnetisation current.
Effect of Specimen Thickness on Delay in Fatigue Crack Growth
Authors: Shih TT , Wei RP 
Published: February 2009

AbstractThe effect of specimen thickness on delay in fatigue crack growth, produced by load interactions in variable-amplitude loading, was examined. Experiments were carried out on 7075-T6 aluminum alloy sheets. The results indicate that delay is a function of specimen thickness. This influence of thickness, along with variations in behavior among different materials, suggest that extensive extrapolation of existing data should not be made.
Inverse Method for Determining Approximate Stress-Strain Behavior of Soils
Authors: Farzin MH , Corotis RB , Krizek RJ 
Published: February 2009

Abstract
A new approach is advanced to analyze and interpret experimental data from a compression test on a cylindrical soil specimen. With a knowledge of the applied axial and radial pressures, the overall axial deformation, and radial deformations at several discrete points on the boundary, a piecewise linear continuum model is used to calculate approximate secant and tangent values for the modulus and Poisson's ratio of two different soils. Although soil moduli are found to be highly stress dependent and significantly influenced by the dry density of the specimen, values of Poisson's ratio are relatively insensitive to these variables. Results obtained by use of this new approach can be used to evaluate the assumptions that are frequently incorporated into simpler interpretation procedures. In particular, a comparison of secant and tangent moduli determined by the proposed method with other modulus values determined by commonly used procedures reveals substantial differences and suggests the use of extreme caution when selecting values of soil parameters for use in mathematical models of soil mechanics problems.
Stress Relaxation in Tension of CA 172 Copper-Beryllium
Authors: Goel RP 
Published: February 2009

Abstract
Stress relaxation data on commercially available copper-beryllium alloy 172 are presented. Test samples were subjected to strains of up to 2% and temperatures from 25 to 181°C. The data show that a high degree of relaxation occurs at higher temperatures and relaxation was found to be independent of the initial stress levels. Time-temperature plots of stress relaxation are presented for designing accelerated relaxation tests on the copper-beryllium alloy tested. The material in the tested condition is generally not used in spring applications and thus results of Austen which compare stress relaxation characteristics of copper-beryllium alloy 172 in the aged and unaged conditions are also presented.
The Strength of Concrete Subjected to Compression-Compression-Tension Stress Systems
Authors: Mahmood N , Hannant DJ 
Published: February 2009

Abstract
An experimental investigation into the failure of a particular concrete subjected to stress fields varying between biaxial compression, compression-compression-tension, and uniaxial tension is described. The results are compared with published data for related stress systems, and the shape of the failure surface in the compression-tension quadrants of stress space is shown to be of the simple hexagonal pyramid type.
Evaluation of an 80Ni-20Cr Alloy in an Enclosed Heating Element
Authors: Starr CD 
Published: February 2009

Abstract
Accelerated life tests on enclosed heating elements were conducted using a constant power cyclic type of test that caused failure in about 500 h. The results were compared to those on a cyclic test run near rated power of the element where failure occurred in approximately 5000 h. The change in both the hot and cold resistance of the heater wire in the accelerated test was about five times greater than in the rated power test. This correlated with a much larger loss in chromium and silicon from the heating coil tested under accelerated conditions.
The cold resistance of the MgO was always over 100 Mω during the test. The hot resistance of the MgO decreased during the test but was always over 3000 times the resistance of the heater coil. This correlated with X-ray fluorescence analyses of the MgO which disclosed no chromium in the midpoint of the MgO to form a continuous conductive path.
The emissivity and convection coefficient of the sheath were essentially constant during the test at rated power.
The accelerated test method selected for range-type enclosed elements is not suitable for predicting the service life of an enclosed element. It is usable as a quality control test.