bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparison of Aluminum Powder Average Particle Diameter Values Determined by Various Methods
Authors: Ping SW 
Published: February 2009

Abstract
Average particle diameters (APDs) from alloyed aluminum powders were obtained by three methods including these instruments: (1) Fisher Sub-Siever Sizer®, (2) Elzone Particle Counter®, and (3) the Microtrac. Although each method was relatively fast and gave consistent results, when compared against each other the differences observed were significant. These differences were caused by the instrumentation and mathematical expressions used in each technique. Generally, the Microtrac and Elzone volume mode APD results were similar for the −325 mesh powders and were approximately double the Fisher APDs for the −270+325 and −325 mesh air-atomized powders. Fisher APDs for spherical powders can be estimated by using the Elzone surface area mode APD values. The Elzone could detect much larger (up to 380-µm) particle diameters than the Microtrac (176 µm) or the Fisher (50 µm) and, therefore, analyzed more accurately the coarser powders. Scanning electron micrographs showed surface roughness and particle size distribution of the powders.
Tensile Properties of A357-T6 Aluminum Castings
Authors: McLellan DL 
Published: February 2009

Abstract
Consideration of high-strength aluminum alloy castings as primary aircraft structure requires assurance that these products will possess structural integrity. Current industrial design practices place factors on properties or loads to offset the unknown characteristics of castings in recognition that the only absolute guarantee of properties is achievable through destructive tests. This paper presents an evaluation of tensile properties and their relationships to physical parameters for A357-T6 castings as an attempt to improve product assurance through nondestructive inspections. By improving both production controls and the measurements of significant physical conditions, it is believed that adequate product assurance can be developed to make these materials competitive with various wrought aluminum alloy fabricated structures.
Influence of Cold Work on the In-Pile Stress Rupture Strength of 16Chromium-16Nickel-Niobium Austenitic Stainless Steels
Authors: Closs KD , Schaefer L 
Published: February 2009

Abstract
The in-pile stress rupture strength of three casts of 16Cr-16Ni-Nb stainless steel was investigated. Different pretreatments were used, namely solution annealing plus various cold-working levels up to 20%. Thermal stability under irradiation and the high-temperature embrittlement of the different material conditions were studied. The specimens were irradiated in the form of electrically heated pressurized tubes at irradiation temperatures ranging from 615 to 720°C. Irradiation time was up to 4800 h, corresponding to a maximum fast neutron fluence (E &gt; 0.1 MeV) of 8.2 × 1025 n/m2.
Neutron irradiation caused a marked reduction in stress rupture strength for the solution-annealed and the cold-worked specimens. For the solution-annealed tubes, this reduction was mainly attributed to high-temperature embrittlement; the decrease in rupture strain was less pronounced for the cold-worked tubes. The reduction in stress rupture strength came mainly from an increase in creep rate. As far as stress rupture strength and creep strength at high irradiation temperatures were concerned, the 15% cold-worked 16Cr-16Ni-Nb steel was superior to the other cold-work levels.
Precision Secondary Resistors
Authors: Starr CD , Graule RS 
Published: February 2009

Abstract
Data on the stability of resistance of four types of secondary standards containing either Manganin® (a copper-manganese-nickel alloy) or nickel-chromium-aluminum-copper resistance wire have been measured for 19 secondary standards. The standards range from 0.01 to 1000 ohms and have been tested annually for about 7 to 14 years, although one standard has been in use and tested for 33 years. The change in resistance in parts per million is documented, and causes for the change are suggested. For the most part, the stability of resistance of the precision secondary standards is much less than the manufactured tolerance of ± 30 ppm/year.
Phase Analysis of Standard and Molybdenum-Modified Mar-M509 Superalloys
Authors: Bišs V 
Published: February 2009

Abstract
Phase characterization studies have been conducted by an ASTM Task Group on interlaboratory specimens of three Mar-M509-type superalloys heat treated to simulate service conditions. The results of the studies, employing X-ray and electron diffraction analysis and energy dispersive X-ray analysis, showed that the alloys contain (a) script-type metal-carbon (MC) carbides, (b) two types of eutectics (both containing M23C6-type carbides), (c) M23C6 carbides precipitated in the vicinity of script-type MC carbides and M23C6 eutectics, and (d) very fine MC carbides precipitated along crystallographic planes of the matrix phase. The molybdenum-modified Alloys XC-224 and XC-224Fe also contain M6C carbides. The compositional and crystallographic data for the phases are presented and discussed.
Gypsum Content of Cements Used in Concrete Cured by Accelerated Methods
Authors: Al-Rawi RS 
Published: February 2009

Abstract
The effects of the gypsum content of cement on several engineering properties of concrete cured by accelerated and normal methods were investigated. It is shown that increased gypsum content results in a significant decrease in the slump of concrete and that there is an optimum gypsum content, considerably higher for accelerated-cured concrete than for normally cured concrete, at which maximum strength is obtained.
Contrary to prevailing theory, the increase in the compressive strength of accelerated-cured concrete with increased gypsum content is too small to warrant a gypsum content higher than that for normal curing conditions. In addition, insufficient SO3 content cannot be the only cause for the reduction in the later-age strength of accelerated-cured concrete compared with that of normally cured concrete. The optimum gypsum content under accelerated curing conditions may be used without risk of reduction in the durability of concrete caused by excessive, delayed expansion.
Verification of Compliance Corrections Used in Determining Load-Line Energies from Dynamic Load-Time Data
Authors: McConnell P 
Published: February 2009

Abstract
Absorbed energy is readily determined by integrating the load versus load-line displacement function. However, in dynamic testing (strain rate approximately 10/s), load-time data are more conveniently obtained. Conversion of load-time data to the energy absorbed by a test specimen during an instrumented impact test requires that the energy absorbed by the test machine be deleted from the total energy represented by the area under the load-time curve. A technique is described whereby previously reported compliance corrections have been experimentally verified. A test specimen is allowed to deflect to an accurately known value. Integration of the quasi-load-deflection curve yields the energy absorbed by the specimen. This value is shown to compare favorably with that obtained from the compliance-corrected load-time curve.
A Fracture Toughness Data Bank
Authors: Kaufman JG , Collis SF 
Published: February 2009

AbstractA data bank containing fully characterized plane-strain fracture toughness test data on aluminum products has been developed for The Metal Properties Council. Procedures were developed for computer storage, retrieval, and analysis of the data. Statistical tolerance limits were determined for two high-strength high-toughness plate products to demonstrate the system's capability. Regression analyses correlating plane-strain fracture toughness values with notch-yield ratios were performed on data for the same two products to generate critical notch-yield ratios. Such critical notch-yield ratios can be used for quality assurance purposes. The fully characterized test data provide system capability for validity criteria revision, although this was not done in the initial contract.
An Optimal Method for Determining Anisotropic Parameters Under Combined Stress Tests
Authors: Ikegami K 
Published: February 2009

Abstract
An optimal test method to determine the anisotropic parameters of the yield condition under a combined stress state is proposed. Because scattering of experimental values affects the calculated results, the combined stress tests should be conducted under conditions that minimize the scattering effect. Hill's anisotropic yield function is used to establish such a test condition.
Laser Scanner for Exoelectron Display and Measurement of Fatigue Damage
Authors: Baxter WJ 
Published: February 2009

Abstract
Fatigue damage in metals can be displayed and assessed by means of exoelectron emission. The surface of a fatigue sample is scanned by a focused ultraviolet laser and the spatial distribution of the exoelectron emission is displayed on an oscilloscope. The operation of the system is illustrated by torsional and reverse bending fatigue tests on two different types of steel. The local intensity of the emission is a quantitative measure of the local deformation and permits the accumulated damage to be expressed in terms of the fraction of fatigue life expended.
Results of Interlaboratory Test Programs to Evaluate the ⅝-in. (16-mm) Dynamic Tear Test Method
Authors: Heberling TG , Harris ES , Lange EA 
Published: February 2009

Abstract
An ASTM Task Group evaluated the “Proposed Method for ⅝-in. (16-mm) Dynamic Tear Test of Metallic Materials.” Effects of testing machine type, impact velocity, specimen geometry, and testing variables on dynamic tear test results were determined. The method was found to be useful in reproducibly determining fracture energy and transition temperature. Difficulties were encountered in pressing the notch tip to the specified depth range, and the method has been modified.
Dynamic tear absorbed energy was not significantly affected by testing machine type or impact velocity. Small but statistically significant energy differences were found among the participating laboratories as a result of specimen preparation and testing variables. Increasing experience with the test method should make possible the reduction or elimination of these differences.
A Modified Fourier Method of Shape and Surface Texture Analysis of Planar Sections of Particles
Authors: Czarnecka ET , Gillott JE 
Published: February 2009

Abstract
A mathematical model based on a Fourier series expansion has been used to represent the roughness of planar sections of particles, that is, the combined effect of shape and surface texture. A new coefficient T is introduced which more precisely expresses the total roughness of the projected two-dimensional profile. It also gives a measure of shape and texture contribution factors separately. The value of the total roughness coefficient depends on the Fourier amplitude coefficients Cn, the length of the perimeter of the profile, and the difference between the maximum and minimum radii. Therefore the value of the total roughness coefficient T is a better representation of grain morphology than is a coefficient derived only from Fourier terms to which shape makes a dominant contribution. This value is the sum of the shape contribution factor Pc and the texture contribution factor Tc.
The Effect of Hygrothermal History on Residual Strength of Glass Fiber Reinforced Plastic Laminates
Authors: Ishai O , Arnon U 
Published: February 2009

Abstract
Structural glass fabric/epoxy laminates were exposed to various periods of immersion in water at room and elevated temperatures and tested after oven drying. Changes in weight, dimensions, and mechanical characteristics with exposure indicated that immersion in hot water had a significant effect on residual weight loss and residual tensile strength. A correlation between these two variables could be derived which is independent of hygrothermal history. The observed deterioration of mechanical properties is attributable mainly to degradative processes to which the glass fiber reinforced plastic laminate is subjected as a result of water penetration processes that are accelerated at elevated temperature.
Fatigue Life and Crack Propagation Analyses of Welded Components Containing Residual Stresses
Authors: Smith KN , El Haddad M , Martin JF 
Published: February 2009

AbstractThis study deals with the fatigue of welded components emphasizing the use of small specimen data, a general stress-strain expression, the fatigue notch factor, and the effect of residual stresses. A computer-based fatigue damage analysis for welded structures is investigated; although accurate fatigue predictions have been made for notched structures, this type of analysis has not previously been applied to welded components. Fatigue crack propagation data are presented emphasizing the mean stress effect on the rate of cracking. Crack measurements have been made for both butt and fillet welded specimens in which the cracks commence from the toe of the weld.For fillet welded attachments and butt welds with substantial reinforcement, a residual stress adjustment was made based on the assumption that the maximum stress at the notch root is equal to yield stress. A fatigue damage analysis for welded specimens subjected to block loading using a computer-based damage model gave results close to experimental data. With a proposed stress function as the controlling stress parameter for crack growth, crack propagation data were successfully correlated.
Enhancement of Compressive Properties of Failed Concrete Cylinders with Polymer Impregnation
Authors: Blankenhorn PR , Kline DE 
Published: February 2009

Abstract
Compressive properties of concrete which was failed in compression and then impregnated were investigated. Specimens were impregnated with a vacuum-pressure technique. The two monomer systems used were epoxy and a methyl methacrylate prepolymer system. The mixing ratio of the methyl methacrylate prepolymer system was adjusted so that its viscosity was very close to that of the epoxy system just prior to impregnation. Control specimens (not failed) were also impregnated with the monomer systems and tested in compression to compare their data with the data of the failed-impregnated specimens. The specimens which were failed and then impregnated had compressive data, stress-strain curves, compressive modulus and compressive strength almost identical to the impregnated controls. The work suggests that the epoxy system used in the study fills the void volume of the specimens somewhat better than the methyl methacrylate prepolymer system.
An Apparatus for Two-Dimensional Measurement of the Shrinkage Resistance of Soils
Authors: Uzan J 
Published: February 2009

Abstract
This paper deals with the behavior of an Israeli fat clay under the combined action of shrinkage due to drying and tensile stresses which develop as a result of controlled shrinkage. Since the behavior is known to be nonlinear, an appropriate theoretical background which permits design of apparatuses and tests is presented. Two apparatuses are described which allow for the measurement of stress and strain in a two-dimensional state of stressing. Results of preliminary tests are presented and analyzed.
A Strain Gage Method for Determining the Mechanical Properties of Filaments
Authors: Swearengen JC , Ericksen RH 
Published: February 2009

Abstract
A test method has been established which permits utilization of strain gages to obtain mechanical properties of filaments. Uniaxial monotonic load-strain and creep measurements were made using several techniques to verify that the method measures properties representative of the flaments. The method eliminates the requirements of obtaining a compliance calibration of the testing machine and has the advantage of facilitating measurements of small strains in filaments having very high stiffness.
Tensile Creep of Angle-Plied Boron/Epoxy Laminates
Authors: Chwirut DJ 
Published: February 2009

Abstract
Tensile creep tests were performed at 75°F (24°C) and 300°F (149°C) on 26 specimens cut from ±30-deg and ±45-deg laminates of boron/epoxy composite material to characterize the creep behavior of these materials. A linear viscoelastic laminate theory proposed by McQuillen was compared with the experimental data for the tests run at 75°F (24°C). The predicted creep strains differed greatly from the measured values, indicating that the linear theory is not applicable to laminates with these filament orientations. A general creep equation of the form ε = kσmtn was fitted to the experimental data with excellent correlation. The stress exponents was fitted to the experimental data with excellent correlation. The stress exponents m varied from 1.79 to 5.17 for the four series of tests, thus characterizing the nonlinear behavior of boron/epoxy laminates with these filament orientations.
A Simple Technique for Determining Relative Strength of Aggregates
Authors: Rad PF 
Published: February 2009

Abstract
The performance of graded aggregate bases can normally be determined from the property indexes of the aggregate materials such as compressive strength, density, abrasion, hardness, and absorption. All these values can be systematically obtained through standardized laboratory operations.
A simple impact technique is advocated for characterization of base materials in the field. This technique, modified from one successfully used in fragmentation operations, uses a cylinder nearly 3 in. (76 mm) in diameter and 26 in. (660 mm) high. A sample of the material is placed on the bottom and impacted with a standard weight. The change in size distribution of the material as a result of several impacts is used to determine the impact strength index (ISI). The value of ISI correlates with unconfined compressive strength and specific energy. Progress is being made to determine correlation of the results of a multisize sample with compressive strength and the Los Angeles number.
Detection of Chrysotile Asbestos in Airborne Dust from Thermosetting Resin Grinding
Authors: Faulring GM , Forgeng WD , Kleber EJ , Rhodes HB 
Published: February 2009

Abstract
Airborne dust samples generated during grinding thermosetting resin plaques containing 0.8 to 18% chrysotile and reference samples were examined optically and on the electron microprobe up to magnifications of ×900.
Chrysotile in dust samples was analyzed by new methods using iodine in solution or as a vapor for selectively staining chrysotile and increasing its visibility and by the NIOSH phase contrast method. No free fibers of chrysotile were detected in dust collected from 0.8% chrysotile-polyester plaques. Only a low-level concentration was found in dust from 4–18% chrysotile-polyester plaques. The difference in texture of chrysotile and cellulose ester membrane (CEM) filters was emphasized by vacuum deposition of aluminum and carbon.
The importance of care in handling chrysotile-bearing CEM filters and the improvement in retention with carbon coating are described.
Electron microprobe methods are presented that distinguish between chrysotile completely encapsulated in resin and chrysotile with a free surface. The airborne chrysotile in the grinding dust was usually nonfibrous, encapsulated in resin, and closely associated with other materials. In the samples analyzed, the number of chrysotile fibers with a free surface varied from zero to two per thousand dust particles.
Methods for estimating the bioconcentration factor of ionizable organic chemicals
Authors: Fu Wenjing , Franco Antonio , Trapp Stefan 
Published: February 2009

Abstract
The bioaccumulation potential is an important criterion in risk assessment of chemicals. Several regressions between bioconcentration factor (BCF) in fish and octanol-water partition coefficient (KOW) have been developed for neutral organic compounds, but very few approaches address the BCF of ionizable compounds. A database with BCFs of 73 acids and 65 bases was collected from the literature. The BCF estimation method recommended by the Technical Guidance Document (TGD) for chemical risk assessment in the European Union was tested for ionizing substances using log KOW (corrected for the neutral species, log[fn·KOW]) and log D (sum of log KOW of neutral and ionic molecule, apparent log KOW) as predictors. In addition, the method of Meylan et al. (Environ Toxicol Chem 1999; 18:664–672) for ionizable compounds and a dynamic cell model based on the Fick-Nernst-Planck equation were tested. Moreover, our own regressions for the BCF were established from log KOW and pKa. The bioaccumulation of lipophilic compounds depends mainly on their lipophilicity, and the best predictor is log D. Dissociation, the pH-dependent ion trap, and electrical attraction of cations impact the BCF. Several methods showed acceptable results. The TGD regressions gave good predictions when log(fn·KOW) or log D were used as a predictor instead of log KOW. The new regressions to log KOW and pKa performed similarly, with mean errors of approximately 0.4. The method of Meylan et al. did not perform as well. The cell model showed weak results for acids but was among the best methods for bases.
Technical basis for polar and nonpolar narcotic chemicals and polycyclic aromatic hydrocarbon criteria. III. A polyparameter model for target lipid partitioning
Authors: Kipka Undine , Di Toro Dominic M. 
Published: February 2009

AbstractA method is presented for extending the target lipid model (TLM) of narcotic toxicity to polar narcotic chemicals. The proposed polyparameter TLM extends the applicability of the TLM by including polar compounds and removing explicit chemical class corrections. The validity of the model is tested using a data set of 1,687 acute toxicity tests for 42 aquatic species, including fish, amphibians, arthropods, mollusks, polychaetes, coelenterates, protozoans, and algae, and 398 chemicals. The target lipid-water partition coefficient is computed using the Abraham polyparameter model. This replaces use of the octanol-water partition coefficient so that the partitioning of polar narcotic chemicals can be described correctly. The model predicts the log median lethal concentration with a root mean square error of 0.460 for nonpolar and polar chemicals and 0.501 for only polar chemicals.