bluuebunny/crossref_metadata_2025_split huggingface dataset:
Automated Fatigue Crack Growth Monitoring: Comparison of Different Crack-Following Techniques
Authors: Ranganathan N , Guilbon G , Jendoubi K , Nadeau A , Petit J 
Published: December 2008

A software has been developed to conduct constant amplitude fatigue crack growth tests on the lines of a standard test method proposed by the American Society for Testing and Materials (ASTM E 647).
In this paper, after a brief description of this software, the results of calibration tests conducted using compact tension specimens of the high-strength aluminum alloy 2024-T351 are presented and discussed.
The crack length was monitored by the compliance technique and the d-c potential drop technique for automated tests and by optical means for manual verification.
Analysis of the results shows that both crack-following techniques are suitable for automated crack growth monitoring. The maximum absolute error for the compliance technique is on the order of 2.5% and on the order of 1.3% for the potential drop technique.
Calibration functions relating the crack length to normalized compliance for measurements under the loading axis and to the potential drop have been determined for the studied specimen geometry.
Finally, the experimental results relating the crack growth rate to the amplitude of the stress intensity factor by the different techniques used are compared.
Service Experience Related to Unspecified Elements
Authors: Schnabel GJ 
Published: December 2008

Over the past 50 years the anomalous behavior of steels has not always been consistent. Part of the inconsistency can be attributed to transient or other conditions that exceeded design conditions. Another part can be attributed to unspecified elements. Conversely, some steels have proven exceptionally capable to withstand their service conditions. Some of the more generic problems were serious enough to generate cooperative group actions to resolve them. Graphitization, weldability, low creep resistance, stress corrosion, caustic embrittlement, poor fracture toughness, shifting nil-ductility transition temperatures, and low upper shelf impact resistance have been some of the more notorious problems.
Until recently there was little attention given to the buildup of residuals (or unspecified elements) in steels where scrap steels were recycled into new product forms. Copper, chromium, cobalt, zinc, tin, nickel, and nitrogen have all influenced the behavior of steels. In some cases they could be beneficial. However, without a clear understanding of their synergistic behavior, it is difficult to predict their service behavior. If our industry potential is to remain strong in its world position, it will be necessary to develop more specific information on materials. We look forward to the successful implementation of the National Materials Properties Data Network (NMPD) to provide the data base from which the generation of new or more specific data will provide more confidence for the least cost.
The Role of Trace Elements in a Martensitic 12% Chromium Steel
Authors: Coulon PA 
Published: December 2008

The comparison of mechanical properties between a “super-clean” heat of a 12% chromium steel and a heat with an identical chemical analysis, but “industrially” produced, does not yield any definite differences. At most it can be ascertained that the “super-clean” heat displays better ductility and impact strength while keeping a comparable strength to that of the other heats.
The comparisons of structures are more interesting and give better results since the study showed (1) that trace elements, especially antimony, (comparison between castings 7–8 and 91) seem to be responsible for the embrittlement of austenitic intergranular boundaries and (2) that no brittle intergranular fracture has been noticed, which distinguishes this superclean heat from the others. Besides, the following comments may be made on superclean heat: (1) the carbides that are visible under the optical microscope (0.5 to 1 m) are still heterogeneously distributed and (2) few carbides are detected in the platelike crystals of martensite.
The main characteristic of this clean heat is to provide a good impact energy and a low transition temperature. For the more in spite of the very clear and relatively abundant precipitations of carbides and carbonitrides in the grain boundaries, no intergranular rupture as shown up during the scanning electron microscope (SEM) examination of the fracture surfaces. One can deduce from this, that the brittle intergranular ruptures observed in the case of heats 7–8 and similar heats are more as a result of the intergranular segregations of trace elements than that of carbides and carbonitrides derived from contents of carbon, nitrogen, neon, niobium, vanadium, and so forth, since all these steels undergo the same thermal treatments.
But it clearly appears that the relationship between the content and distribution of these various carbides and the mechanical properties measured (creep, impact strength) is of prime interest for future research. This paper does not claim to establish this close relationship. Moreover, it is not absolutely certain that this study would be interesting to the mechanics specialist. A materials specialist might well have an opposed opinion.
Oxygen Fires, Materials Compatibility and System Contaminants
Authors: Barter SA , Hillen LW 
Published: December 2008

Following the destruction of a Royal Australian Air Force (RAAF) Orion Aircraft due to a fire which initiated in an aluminum component of the aircraft oxygen system [1], the authors have been requested to investigate a range of incidents in, and problems associated with, oxygen systems, of which several are described and discussed here.
While many of the incidents can be attributed to high levels of contamination or physical deficiencies or both. within the equipment, attention is given to the contribution made by the oxygen component designer, in mechanical design and materials selection.
Many of the tests for oxygen compatibility are carried out on single components. In practice, however, real oxygen systems become contaminated with frequent use or abuse or both. Therefore it is important for the designer to have information not only on material performance in oxygen, but also on the oxygen compatibility of the spectrum of potential contaminants and combinations of contaminants that come in contact with these construction materials.
Comments are made on valve designs which are considered particularly sensitive to system contaminants. It is suggested that design philosophy should address sensitivity to contamination and design codes should identify and if necessary bar “poor practice”, since the oxygen system user will not usually have ready access to the technical expertise needed to evaluate designs in the time frame required for critical decisions.
The severity of gaseous oxygen fires is intimately related to the period of oxygen flow. There is a need for an automatic shut-off device that would operate when abnormal flow conditions occur. One such device is described and its limitations discussed. It is concluded that a successful design would possibly be based on a mass flow characteristic.
Mechanical Evaluation of ASTM F75 Alloy in Various Metallurgical Conditions
Authors: Spires WP , Kelman DC , Pafford JA 
Published: December 2008

This study evaluated the mechanical properties and microstructure, in various metallurgical conditions, of an alloy meeting the requirements of the ASTM Specification for Cast Cobalt-Chromium-Molybdenum Alloy for Surgical Implant Applications (F 75–82). Standard mechanical property analyses such as tensile and yield strength, percentage of elongation, and rotating-beam fatigue tests were performed. The materials were tested in the as-cast, as-cast plus solution-annealed, as-cast plus hot-isostatic-pressed (HIP) plus solution-annealed, and as-cast plus HIP plus sintered conditions. Chemical analyses of the test specimens were reviewed to determine the extent of the correlation between mechanical properties and certain elements within the alloy, as has been suggested by other authors.
No effect on ultimate tensile strength was observed with a reduction of carbon content from 0.30 to 0.24%, but a reduction of the yield strength and a corresponding increase in ductility were observed. The as-sintered surface appeared to reduce the fatigue properties of the test specimens. A direct correlation between the fatigue properties, static mechanical properties, and microstructure was not established.
Development of Tricalcium Phosphate Ceramic Cements
Authors: Bajpai PK , Fuchs CM , McCullum DE 
Published: December 2008

Slowly resorbable and relatively nonresorbable bone cements have been developed to repair various types of defects in bone. A relatively fast-resorbing, porous, biocompatible beta tricalcium phosphate (TCP) cement would be ideal for replacing bone lost as a result of nonresorptive processes. In this investigation the following materials were tested as setting agents for developing a resorbable TCP cement: bovine serum albumin, Carbopol, Hespan, monomers of low-molecular-weight carboxylic acids, orthophosphoric acid, polyvinyl pyrrolidone, and water.
Initial experiments consisted of determining the amounts of setting agent or water or both required to gel the TCP powder. The gel time was monitored at 30-s intervals. The setting hardness was determined by mixing the optimal proportions of TCP and setting agent or water, or both, and monitoring the hardness at 15-min intervals at room temperature for 105 min. Mixtures of TCP and monomers of low-molecular-weight carboxylic acids yielded the most efficient cements. By varying the quantity of acid or combining different acids, or combining both methods, setting times from 30 s to 8 min were achieved for the TCP/polyfunctional acid cements. These cements have been used successfully to repair experimentally traumatized tibiae and femora in rabbits and rats, respectively.
On the Use of the R50
Authors: Engeman RM , Otis DL , Bromaghin JF , Dusenberry WE 
Published: December 2008

R50 is a statistic used to describe the repellency of a substance in the manner that an LC50 is used to describe toxicity. Although the R50 is calculated using the same methods as for estimating an LC50, the data initially collected on individual animals are proportional, not binary. Transforming nonbinary data into binary data is subjective, can result in substantial losses of information, and, consequently, can result in a greater chance for erroneous inferences concerning the repellency of a substance. The subjective nature of R50 estimation arises because a test animal is defined as repelled if less than 50% of treated food items are consumed. The R50 is calculated as the concentration at which 50% of the population consumes less than 50% of the food times. It is more appropriate and of more direct interest to estimate the concentration of a substance at which an average of 50% of the food items are consumed rather than to estimate the R50.
Problematic aspects of R50 estimation are demonstrated in this paper, and alternative analyses are recommended for studying the repellency of a substance. Example data sets are used to compare inferences from estimation of an R50 versus use of inverse regression methods to estimate concentrations at which various proportions of food items are consumed.
Evaluation of Accreditation Systems and Their Demands on the Independent Testing Laboratory
Authors: Stanger DH 
Published: December 2008

for over a decade governments have been introducing laboratory accreditation schemes in support of their national quality campaigns. Review of national standards and measurement systems has taken place with international competitiveness in mind. The independent testing laboratory owner has been invited to join the voluntary club of accredited laboratories.
This paper describes the experiences of one independent laboratory organization with accredited laboratories in the United Kingdom, Australia, and Hong Kong and will also refer to the author's experiences as a member of national and international organizations involved in the development of systems for the assessment of testing and calibration services.
Accreditation of Medical Laboratories in Australia
Authors: Gilmour JA 
Published: December 2008

Medical laboratories in Australia are required to be accredited by either the Commonwealth government or by one of the state governments. Arrangements vary from state to state but almost all rely on an on-site assessment conducted by the National Association of Testing Authorities, Australia (NATA) in collaboration with the Royal College of Pathologists of Australasia (RCPA).
This paper describes the background to this system and outlines the complementary roles of the various organizations involved. Some information is also provided on criteria development, selection and training of assessors, and the assessment process as employed by NATA. The role of proficiency testing programs operated by bodies such as RCPA, Wellcome Laboratories, and the College of American Pathologists is also mentioned.
The system has been operational since 1983, and over 100 separate laboratories representing approximately 300 laboratory units have been accredited. This paper comments on the outcome of those assessments.
Radiation-Induced Creep of Aluminum and Copper
Authors: Ibragimov SS , Aitkhozhin ES , Pyatiletov YS 
Published: December 2008

Results of experimental and theoretical investigations of in-reactor creep of metals are presented in this paper. Experiments have been made in the WWR-K reactor at a neutron flux density of 1.4 × 1016 n/m2 · s (2.5 × 1015 n/m2 · s, E &gt; 0.1 MeV). Polycrystalline aluminum (99.99%) and copper (99.99%) have been investigated. Aluminum specimens have been examined at temperature levels of 333 to 473 K and stresses of 9.8 to 24.5 MPa, and copper specimens at 423 to 773 K and 20 to 69 MPa, respectively.
Experiments indicate the steady state creep rate depends on stress as ˙ε ∼ σn (n ≈ 3 for aluminum and n ≈ 5 for copper) and increases with increasing test temperature. Three regions with different slopes are observed on the temperature versus creep rate ˙ε(1/T) curve.
Theoretical calculations of the creep rate of irradiated metal as a function of the temperature have been carried out within the framework of the model based on the dislocation climb and glide. Calculation of the temperature dependence of the creep rate established that three temperature regions were recognized as in the case of experiments on copper.
Effects of 14-MeV Neutron Irradiations on Mechanical Properties of Ferritic Steels
Authors: Kohyama A , Asano K , Igata N 
Published: December 2008

Seven kinds of 9Cr-2Mo type ferritic steels were irradiated at 300, 473, and 673 K with 14-MeV neutrons from Rotating Target Neutron Source II (RTNS-II) at Lawrence Livermore National Laboratory (LLNL). The maximum neutron fluence was 4 × 1022 n/m2. Post-irradiation mechanical property tests, microVickers hardness tests, microtension tests, and micro-bulge tests were performed. Microstructural evolutions under irradiation were examined by transmission electron microscopy.
Irradiation hardening and softening were observed at 300 K and at elevated temperatures, respectively. Radiation induced defect cluster formation was observed. The clusters were identified as mostly vacancy type complex defects from their fluence dependence. The irradiation hardening can be reasonably explained by the dispersion hardening from these complex defects. The correlation of mechanical properties among miniaturized sample tests, which are initially derived for unirradiated materials, have proved to be valid for the neutron irradiated specimens with fluences up to 4 × 1022 n/m2. Specimen size effects on tension test results were investigated.
Steel Impurity Element Effects on Postirradiation Properties Recovery by Annealing
Authors: Hawthorne JR 
Published: December 2008

The influence of copper content and phosphorus content on notch ductility recovery by 399°C postirradiation heat treatment was explored for A 533-B and A 302-B pressure vessel steels. Charpy-V (Cv) specimens for the investigation were obtained from ten plates produced from four (4-way split) laboratory melts. The plates were 15.2 mm thick but were heat treated to reproduce the microstructure of 150-mm and thicker A 302-B plates at the quarter-thickness location.
The Cv specimens were irradiated in two assemblies at 288°C (550°F) to a fluence of ∼2.5 × 1019 n/cm2 in a light-water-cooled and moderated test reactor. Notch ductility properties in the as-irradiated and 399°C, 168 h postirradiation-annealed conditions were determined. In addition, separate sets of specimens were thermally conditioned at 288°C and at 288°C followed by 399°C to benchmark the effects of temperature in the absence of irradiation.
The results indicate that copper has a significant influence on the magnitude of residual embrittlement after annealing. In contrast, phosphorus contents in the range of 0.002 to 0.025% were found not to have an effect on residual embrittlement either in high or low copper steels. Essentially full recovery in 41-J transition temperature was observed for high phosphorus, low copper content steels. Effects of nickel alloying on recovery behavior were also investigated through data comparisons for A 302-B versus A 533-B plates.
The Effects of Radiation on Organic Matrix Waste Forms
Authors: Phillips DC , Johnson DI , Burnay SG , Hitchon JW 
Published: December 2008

This report summarizes the results of a program carried out between July 1981 and March 1985 on behalf of the Commission of European Communities (CEC) and the Department of Environment (DoE). The effects of gamma and alpha irradiation have been studied on a range of bitumen and polymer matrix waste forms.
Under irradiation, bitumens swell because of the nucleation and growth of bubbles of radiolytic gas. Swelling depends on dose rate and specimen size, as well as total dose, but accelerated tests can be carried out by irradiating specimens of varied size under the same conditions of dose rate × specimen depth squared. Swelling commences at around 50 kGy and saturates at 300 kGy. The magnitude of swelling depends on the type of bitumen. For bitumenisates used in Europe the magnitude is ≤ 10%. The effects of alpha radiation are more severe than equivalent doses of gamma radiation but are unlikely to have a significant effect on physical properties in practice. Irradiation to 10 MGy and swelling have no significant effect on leach rates.
The behavior of polymer waste forms under gamma irradiation is more complicated. The most pronounced effects occur with waste forms containing wet wastes. Some of these can shrink by substantial amounts on irradiation caused primarily by water loss. Others exhibit small amounts of swelling or shrinkage and the exact behavior appears to depend on a combination of bubble growth, polymer cross linking, and water desorption. Data are presented on the effects of radiation on leaching and on radiolytic gas evolution.
Overview of Indoor Air Quality Sampling and Analysis
Authors: Levin H 
Published: December 2008

During recent years, sampling and analysis of atmospheres for indoor air quality in non-industrial environments have increased substantially. Enhanced understanding of indoor air pollution has resulted. Increased recognition of the complexity of indoor environments has led to even more sampling and analysis. Many methods used for indoor air are similar to those employed in workplace and ambient air. However, sampling conditions are often difficult; a very large number of pollutants are usually present, although at low concentrations; some pollutants of concern are at extremely low concentrations; and complex mixtures can create interferences.
Instrumentation requirements differ from those of ambient or industrial applications. Passive monitors and other unobtrusive monitoring equipment have received much attention. Sampling and analysis for biological aerosols will probably increase during the next few years. Other environmental factors are often critical and must also be characterized or measured. Social science and health investigatory methods are often employed in conjunction with air monitoring. Further research and development are needed for standardization in several areas including the sampling and analysis of organic compounds at very low concentrations, the general acceptance of standardized monitoring protocols, and guidelines for the consistent reporting and interpretation of data.
Special Calibration Systems for Reactive Gases and Other Difficult Measurements
Authors: Dorko WD , Hughes EE 
Published: December 2008

The most popular method for determining a component of interest in a gas mixture is to use a detector that responds to the analyte and is calibrated directly with a cylinder gas mixture containing the analyte at the approximate concentration of interest. In many instances, however, this cannot be achieved; cylinder calibration mixtures may be unstable or the direct response detector may not be sensitive enough. The unstable cylinder mixture can be replaced by a dynamic dilution gas calibration system where the analyte can be introduced by any one of several means including permeation devices, or a higher concentration gas mixture that can be more easily stabilized. If the detector for the analyte is insensitive or difficult to calibrate, then the analyte can be converted to another compound for which there is a detector that is sufficiently sensitive and easy to calibrate.
In the case of analytical systems, such as gas chromatography, where separation occurs, a mixture of a stable gas can be used to calibrate for a reactive gas if the relative detector responses are known. There is no one particular way to either provide calibration mixtures for the analysis of all reactive gases or to provide a means for the determination of difficult compounds. Any system that will produce a mixture of the required concentration, of acceptable uncertainty, and of stability sufficient for the analysis at hand can be a special calibration system.
A Comparative Study of Dynamic Impact and Static Loading of One-Ply Roofing Assemblies
Authors: Koontz JD 
Published: December 2008

In just the past few years, there has been industry-wide acceptance of the use of oneply roofing systems. This has basically involved three major groups: elastomerics, thermoplastics, and modified bitumens. The use of these different one-ply membranes over a variety of substrates has led to a virtual collage of roofing systems available on the market today.
The relative puncture resistance of these membranes, in conjunction with their substrates, has not been clearly understood. At present, several different methods of measuring static and dynamic puncture resistance are used by a variety of organizations, such as ASTM, the Canadian General Standards Board (CGSB), the European Union of Agrement (EUAtc), and various manufacturers.
This paper addresses some preliminary data relating to the dynamic and static puncture resistance of one-ply assemblies.
Coefficient of Expansion Values for Modified Bitumen Roof Membranes
Authors: Dupuis RM , Lee JW 
Published: December 2008

A laboratory study was undertaken to determine the nature and the value of the coefficient of expansion for a wide variety of modified bitumen roof membranes. Tests were run from temperatures of 48.9°C (120°F) down to −40°C (−40°F) with observations being made at discrete temperature points. Regression analysis was used to establish a continuous curve for the coefficient of expansion values. This allowed for either tangent or secant coefficient of expansion values to be derived at any point (or between any two points for the secant coefficient) along the temperature range.
These data are provided as basic information on the possible range of variation in the coefficient of expansion for these materials. The range of coefficients presented in this paper has been found to be an important factor in evaluating design and performance standards for roof membranes using these sheets.