bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development of Acoustic Emission Testing for the Inspection of Gas Distribution Pipelines
Authors: McElroy JW 
Published: March 2009

This paper describes how a utility became interested in acoustic emission testing for the survey inspection of its buried gas pipelines. Several weld failures emphasized the need to develop inspection techniques to monitor these pipelines in order to locate weld flaws in high-stress regions to permit prompt weld repairs and assure system integrity. It was found that a weld must have a certain metallurgical flaw and must be located in a high-stress region in order to precipitate an inservice oxyacetylene weld failure in a pipeline. It was found that metallurgical flaws in high-stress regions can be located by acoustic emission tests.
This paper describes the field development of the acoustic emission testing technique and the correlation of the field results with the laboratory results. It was found that the stress levels imposed by either internal pressurization or by external loading in the field tests are sufficient to cause critical flaws to emit and be located. Then replacement or reparation of the critical flaws located in this manner would restore the integrity of the pipeline. Discussed in the paper are the other nondestructive correlations such as radiography and correlations through tension tests, hydrostatic tests, bend tests, and fatigue tests.
The International System of Units (SI)
Authors: Graham JD 
Published: March 2009

The world's dependence upon measurement is an old story in which a new chapter is being written by the introduction of SI, The International System of Units. The United States is now changing to this system.
The system is given in detail and its unique characteristics described. The units outside the system that will continue to be used are discussed. Style and manner of applying the units are detailed.
A brief discussion of the problem of converting from one system of units to another is included. Difficulties of using SI and possible remedies are also covered.
Metrication in the Contract Tooling and Machining Industry
Authors: Darrone DW 
Published: March 2009

The contract tool, die, and precision machining industry faces unique problems in the area of metrication due to its role as a supplier industry.
Although little work to metric specifications is presently being done, and a significant level of awareness exists in the industry regarding the trend toward metrication, only a very small segment of the industry has any definite plans for handling the transition.
Metrication at Vauxhall Motors Limited England
Authors: King AF 
Published: March 2009

Metrication is being progressively introduced at Vauxhall Motors Limited generally in line with the recommendations of the Metrication Board set up by the British Government, and the Society of Motor Manufacturers and Traders. A Coordination Committee was given responsibility to consider all aspects and implications of the change, to determine the approach to be taken, and to allocate priorities.
Application to all new products became effective with the commencement of the 1972 model year, and non-product changes are programmed annually in accordance with internal needs and external progress.
Special attention has been given to color identification of fasteners and to the provision of personal tools and measuring instruments. The current status reported by each and every operating department within the company illustrates the wide ranging implication of this fundamental change.
Metric Conversion at General Motors Corporation
Authors: Streichert EJ 
Published: March 2009

This paper attempts to describe how a large international manufacturing complex arrived at the decision to convert operations to the metric system with the subsequent issuance of general guidelines from management.
The implementations of metrication from these general guidelines is further explained with a discourse of the metric organizational structure, including channels of communication, rate of conversion, standardization procedures, and personnel training modules. Also included is a typical example of the type of investigation required to derive an internal metric interim standard.
New Method of Microscopic Inclusions Ratings for Specialty Steels in West Germany
Authors: Barteld KGH 
Published: March 2009

For the determination of the microscopic degree of cleanliness, many charts and evaluation methods are in use internationally.
A summary of the best elements from the established methods used by the experts in West Germany is described. A procedure is given to the metallographer that sufficiently describes the microscopic degree of cleanliness as to shape, frequency, and size of the inclusions. The result is suitable for a statistic evaluation with modern computers.
Several Rating Methods of Nonmetallic Inclusions in Bearing Steels in Japan
Authors: Koyanagi A , Kinoshi M 
Published: March 2009

The history of rating methods of nonmetallic inclusions in Japan, the background behind the adoption of the Microscopic Testing Method for the Nonmetallic Inclusions in Steel (JIS-G-0555), and the details of this original method are discussed.
To determine the relationship between the cleanliness index values obtained by this method and those obtained by the ASTM Recommended Practice for Determining the Inclusion Content of Steel (E 45-63), Method A, and the U.S.S.R. Microscopic Testing Method for Nonmetallic Inclusions in Ball and Roller Bearing Steel (GOST-801-60), the inclusion ratings of some bearing steels are examined by these three methods at the same time, and the different cleanliness indexes obtained by each method are compared.
Nonmetallic Inclusion Rating and Fatigue Properties of Ball Bearing Steels
Authors: Rousseau D , Seraphin L , Tricot R 
Published: March 2009

We have had the opportunity to apply the most widely used methods of inclusion rating; and, from our experience, it appears that all metallographic methods, including the use of the quantitative television microscope, give roughly equivalent results as far as heat to heat comparison is concerned.
In this respect, the ASTM Recommended Practice for Determining Inclusion Content in Steel (E 45-63), adopted by the French Bearing Steels Quality Standard (NF A 35-565), appears to be one of the simplest and most readily achievable. Nevertheless, the addition of more precise practical rules would be useful in order to improve laboratory to laboratory reproducibility.
From the point of view of service behavior, it should be emphasized that fatigue properties do not depend upon the overall cleanliness of the steel but, mainly, upon the chemical nature of each type of inclusions. The nondetrimental effect of sulfide inclusions is now widely accepted, but the case of oxide inclusions needs to be carefully considered.
The major problem is, therefore, to afford realistic values for the permissible limits of every type of nonmetallic inclusion.
Relevance of Steel Cleanness and Fatigue Tests to Bearing Performance
Authors: Johnson RF , Sewell JF , Robinson JL 
Published: March 2009

A collaborative program of work undertaken in England to compare bearing steels by different types of fatigue tests and to relate the results to the cleanness of the steels as measured by the standard Jernkontoret (JK) method is described. Four bearing manufacturers, their tube maker, and three steelworks cooperated, and the results were generated by six laboratories.
Two casts of one percent carbon-chromium steel were selected by JK inclusion assessments as having widely different cleanness levels. One cast met the prevailing bearing steel standards while the other cast was very inferior to these standards. Randomized samples of tube and bar were supplied from these. These samples provided specimens for all six laboratories to perform fatigue tests using rigs of the Unisteel type and material for three bearing manufacturers to produce and test bearings of the type and under conditions used for normal approval purposes.
The results were reassuring in that all tests confirmed the order of quality indicated by the inclusion counts. In the rig tests agreement between laboratories was reasonable when the fatigue lives were compared on the basis of life distribution curves. Nevertheless, some anomalies occurred; and, in the case of the bearing tests, the match was even less complete. Up to the present time, emphasis has been placed largely upon inclusions as the cause of these anomalies as well as the scatter between the results of individual specimens; but, other quality aspects should perhaps be taken more into account in establishing the true causes.
Effect of Nonmetallic Inclusions on Rolling-Contact Fatigue Life in Bearing Steels
Authors: Kinoshi M , Koyanagi A 
Published: March 2009

Rolling-contact fatigue life tests were studied to evaluate the effect of nonmetallic inclusions in bearing steels similar to AISI 52100.
Fatigue tests were conducted on a test machine that was composed of a round disk specimen substituted for the housing washer of a thrust ball bearing. The specimen was loaded at 455 and 500 kg/mm2 (4.46 × 109 and 4.90 × 109 N/m2) in maximum hertzian stress, lubricated with spindle oil, and operated at room temperature.
The results of the fatigue tests showed that alumina-type inclusions were very harmful to fatigue life, but sulfide inclusions not only had no influence but increased the fatigue life in air-melted and even vacuum-melted steels. In electro-slag remelting steel, increased fatigue life indicated the possibility of effects with the exception of nonmetallic inclusions.
Reliability Aspects of a Composite Bolted Scarf Joint
Authors: Reed DL , Eisenmann JR 
Published: March 2009

A wing splice representative of a next-generation transport aircraft requires an extended fatigue life and the capability of disassembly and reassembly. The design, fabrication, static test, and fatigue test of both tension and compression graphite-epoxy candidates for such a splice was the objective of the research program reported here. A single-scarf bolted joint was selected as the design concept.
Test specimens were designed and fabricated to represent an upper surface and a lower surface panel containing the splice. The load spectrum was a flight-by-flight random load history including ground-air-ground loads.
The results of the fatigue testing indicate that, for this type of joint, the inherent fatigue resistance of the laminate is reflected in the joint behavior, and consequently the rate of damage accumulation is very slow under realistic fatigue loadings.
Shear Property Measurements of Adhesives in Composite Material Bonded Joints
Authors: Renton WJ , Vinson JR 
Published: March 2009

A test specimen has been designed and procedures developed for determining the effective shear modulus, shear proportional limit, and ultimate shear strength for adhesive materials used in bonded lap joints between adherends of either metals or composite materials. By utilizing adhesives in their joint geometry, effects of errors from using bulk property data are avoided. Surface interaction phenomena between adhesive and adherend, surface roughness effects, etc. are automatically included.
Test data to date are presented for adherends of 1002 S-glass uniply and angleply construction, and Hysol EA951 adhesive. Effects of adhesive thickness and joint length are also presented.
Measurement of Thermal and Mechanical Properties of Graphiteepoxy Composites for Precision Applications
Authors: Freund NP 
Published: March 2009

Results are reported on an investigation to evaluate the usefulness of selected graphite-epoxy composite structures for applications requiring precision tolerancing and dimensional control. GY-70/X-904 laminate composites in the double symmetric design (0/ ± 45/90)2s were tested, as well as a honey-comb design having two singly symmetric GY-70/X-904 faceplates bonded to an aluminum core.
Measurements were made to evaluate the coefficient of thermal expansion and its directional variations at 0, 45, and 90 deg to the outermost fiber orientation. Additional measurements of the coefficient included variations normal to the surface. Nondestructive testing employing holography was conducted to determine microcreep behavior.
Optical processing methods were investigated and mirrors with three types of reflector surfaces were fabricated. Environmental testing, including thermal cycling, thermal stability, humidity/vacuum effects, and temporal stability, was done on mirrors representing the various processing methods.
Data, discussion of results, and recommendations for applicable areas are given for the specific material and design types tested.
Reliability of Composite Zero-Expansion Structures for Use in Orbital Environment
Authors: Berman LD 
Published: March 2009

Composite sandwich structures, composed of graphite-epoxy face sheets on aluminum honeycomb core, were found to successfully withstand 15 000 thermal cycles between -250 and 150°F (-157 and 66°C) in vacuum. Although thermal cycling induced microcracking in the face sheets, laminate flexural and tensile properties were unaffected, and the only noticeable effect was on the coefficient of thermal expansion and flatwise tensile strength of the sandwich. In addition, exposure of the structure to 95 percent relative humidity resulted in a finite change in dimensions, but no effect on the coefficient of thermal expansion.
These environmental effects were determined on composite sandwich structures selected for isotropy, uniformity of mechanical properties at temperature extremes, and balanced thermal expansion characteristics in two perpendicular directions.
Molecular Correlations with Fracture in Fibers and Granular-Filled Composites
Authors: DeVries KL , Lloyd BA , Wilde TB 
Published: March 2009

Failure in polymeric materials might be envisioned as occurring by any of several molecular mechanisms. Where homolytic bond rupture occurs, free radicals (unpaired electrons) result. This paper presents results of electron spin resonance studies of chain-scission kinetics in (1) oriented nylon fibers and (2) in granular-filled elastomer composites.
The most extensive work to date has been done on high-strength oriented fibers. It has been concluded that many of the desirable properties of fibers can be attributed to their own microscopic physical composite nature. A reaction-rate molecular model is proposed and is successfully used as a failure criterion to predict failure under various loadings.
The model assumes a statistical distribution in stress on the polymeric chain structure. Failure first occurs in the more highly stressed regions with a subsequent redistribution of the load among the unfractured elements in the fiber. Once the physical parameters are determined for a given material, behavior for other loading is predicted by numerical techniques. Electron spin resonance was used also to investigate interfacial failure in filled composites. Depending on the magnitude of the interactive forces, failure at the interface between the filler and the matrix may be largely adhesive (dewetting) or cohesive in nature. In the former case little or no detectable bond rupture occurs while in the latter case significant free radical concentrations may be produced. Electron spin resonance and scanning electron microscopy are used to systematically investigate the role of the surface interaction, dewetting, etc. on the strength and toughness of composites.
Qualification of Source Test Methods as Reference Methods
Authors: Howes JE , Pesut RN 
Published: March 2009

Air pollution measurements require test methods that have a demonstrated capability to yield reliable data when the procedures are carried out by people with different backgrounds and experience. Collaborative testing can provide “real world” situations in which the performance of test methods can be evaluated and useful measures of the accuracy and precision of data obtained by a given method can be obtained. For methods designed to measure emissions from stationary sources, this form of round robin approach requires that the samples be collected on-site and simultaneously by the various teams involved. Laboratory analyses of the samples can then be performed on an individual basis. Statistical analysis of the collaborative test data from properly designed experiments should yield estimates of within-laboratory and between-laboratory precision and accuracy of the method under test. It should also be possible in some cases to separate the overall accuracy and precision into the individual components due to sampling techniques and laboratory analytical procedures.
This discussion is concerned with measurement methods for gaseous emissions from stationary sources. The circumstances and data cited are based on experience with the American Society for Testing and Materials Project Threshold test program. Collaborative testing of methods for sulfur oxides and nitrogen oxides is discussed specifically; however, the considerations involved with the experimental design, conduct of the testing, and data analysis are applicable to testing of other methods. Collaborative sampling was performed at both an oil- and coal-fired power station, a foundry, a cement plant, and using a pilot-plant furnace unit with gas and oil firing. Samples which were spiked with known amounts of the pollutant gases were included at the pilot plant site to provide a measure of the accuracy of the methods.
Sampling for sulfur oxides was accomplished by a continuous method in which the sulfur trioxide was condensed from the gas stream and the sulfur dioxide was absorbed and reacted with a hydrogen peroxide solution. Both sulfur oxides were then determined by the barium chloranilate method. The nitrogen oxides were samples by a “grab” technique in which an evacuated bulb was used to collect the gas sample. The nitrogen oxides were reacted with acidified hydrogen peroxide in the bulb, and then determined by the phenol disulfonic acid method.
Statistical analysis of the collaborative test data provides equations which express the accuracy and precision of the methods as functions of the gas concentration. Accuracy and precision of the analytical procedures also were measured from analyses of standard reference materials by the participating laboratories.
A Mechanical Toxicant Injector for Flow-Through Toxicity Tests
Authors: Ozburn GW , Smith AD 
Published: March 2009

An injector is described for delivering a series of constant concentrations of toxicant in a flow-through toxicity test. The apparatus can be employed either as a single channel unit for use with a proportional diluter or as a multichannel injector for use with an equal-volume water delivery system. The multichannel approach is emphasized for pesticide addition because the test concentrations are independent of each other. This allows the establishment of an unlimited range of toxicant concentrations.
Water is passed through a series of buckets which are capable of downward vertical displacement. The dropping buckets operate a series of pipettes which introduce the toxicant material to the system. Each channel is calibrated independently by controlling the stroke distance of the pipette plunger. A return spring mechanism automatically reprimes the pipettes for the subsequent water cycle.
Although the system is suitable for toxicity tests employing freshwater diluent, the metal components of the injector may be susceptible to corrosion under saltwater conditions.
Method for Assessing Additive Toxicity of Chemical Mixtures
Authors: Marking LL 
Published: March 2009

Mixtures of chemicals or pesticides may produce unexpected effects; some are hazardous and some are beneficial. A method was divised in which individual toxic contributions of chemicals are summed, and the additive toxicity is defined by an index for two or more chemicals in combination. This linear index expresses the toxicity quantitatively: zero indicates simple additive toxicity, negative values indicate less than additive toxicity, and positive values indicate greater than additive toxicity. The significance of index values near zero is assessed by substituting values from the 95 percent confidence intervals into the formula to determine whether the range for the additive indices overlaps zero (simple additive toxicity). The range is derived by selecting values of the 95 percent confidence interval yielding the greatest deviation from the additive index.Mixtures of malathion and Delnav were found to be extremely toxic, and the additive index for the mixture against rainbow trout (Salmo gairdneri) was 7.20; that is, highly synergistic. Mixtures of copper, zinc, and nickel were additive in toxicity to rainbow trout. Mixtures of commercial synergizers sulfoxide or piperonyl butoxide with rotenone produced greater than additive toxicity against rainbow trout (indices = +2.13 and 2.36).
Utility of Toxicity Tests with Embryos and Fry of Fish in Evaluating Hazards Associated with the Chronic Toxicity of Chemicals to Fishes
Authors: Macek KJ , Sleight BH 
Published: March 2009

The hypothesis that concentrations of toxicants safe to fish over their entire life cycle can be estimated from the results of continuous exposure of embryos and newly hatched fry has been examined critically in the light of recent data. The assumptions underlying the proposed hypothesis appear to be: (a) the chemical does not exhibit significant cumulative toxicity; (b) there is a single mode of action through which the effect of the chemical is manifested in a relatively short time frame; and (c) the effect is most severe on the critical life stages (that is, embryos and newly hatched fry), where parameters such as hatchability, survival, and growth can be measured readily.
The majority of available data indicate that the hypothesis is valid. In most cases, estimates of specific application factors derived from exposure of critical life stages reasonably approximate specific application factors empirically derived from chronic toxicity studies with much less cost, effort, and time required. Other data suggest that exposure of critical life stages of fish can indicate to the researcher certain of those chemicals for which the underlying assumptions are not valid and for which the hypothesis is not applicable. In all cases, estimates of specific application factors derived from critical life stage studies provide information equal or greater in predictive value than information derived from the use of an arbitrary general application factor.
Methods for Improving the Impact Resistance of Composite Materials
Authors: Beaumont PWR , Riewald PG , Zweben C 
Published: March 2009

A three-phase program to improve the impact resistance of composite materials was undertaken. In the first phase, the Charpy impact test was investigated for its utility in characterizing impact performance. It was found that the results of the standard Charpy test can be misleading, but the addition of instrumentation to provide load and energy histories can make this test a useful one. The importance of differentiating between initiation energy and propagation energy is shown, and a new parameter (the “Ductility Index”) is proposed, along with maximum stress and total energy, as a useful measure for comparing impact behavior of materials.
The instrumented Charpy test was used to investigate impact behavior of unidirectional, epoxy-matrix composites reinforced with fibers of E-glass, Kevlar 49, and graphite. In addition, two unidirectional hybrid composite materials consisting of graphite and Kevlar 49 fibers in epoxy were investigated. Comparisons were made with quasi-static three-point bend tests. It was found that the hybrid materials had significantly higher impact energies, ductility indices, and maximum stresses than the all-graphite fiber material.
Impact behavior of [±45] graphite/epoxy and hybrid Kevlar 49-graphite/epoxy panels, representative of aircraft fuselage shear panels, was studied using a ball-drop test. Results indicate a significant improvement in impact resistance with hybrid construction.