bluuebunny/crossref_metadata_2025_split huggingface dataset:
Geotechnical Testing Considerations in the Determination of Laboratory Permeability for Hazardous Waste Disposal Siting
Authors: Zimmie TF 
Published: March 2009

The paper deals with the laboratory determination of permeability (hydraulic conductivity) as applied to hazardous waste disposal siting studies. Probably the most important hydrogeologic parameter in a hazardous waste siting study is permeability. It is also the most variable property of soils, and this variability causes many problems in the laboratory, especially in the fine-grained soils typically tested for hazardous waste siting studies.
The determination of seepage velocity is discussed, and the importance of the groundwater level for hazardous waste disposal sites is considered.
The best overall laboratory device to determine permeability appears to be the triaxial device, utilizing the proper application of backpressure. The use of rigid wall permeameters or consolidation theory to determine permeability is not recommended, since unconservative results are generally obtained.
Subsurface Investigation of Metal Sludge and Explosive Disposal Pond Areas
Authors: Phung HT , Bulot MW 
Published: March 2009

A subsurface investigation at Area G (metal sludge) and O (explosives) ponds located in the Lone Star Ammunition Plant, Texarkana, Texas, was initiated. The study included review of existing data, site drilling, and sampling and analysis of soil and water.
Results indicate that the ponds are underlain by massive clay beds (aquiclude), and the potential for contamination of the usable ground water supply appears to be remote. No significant migration of hazardous contaminants through subsurface soils was observed.
Groundwater quality is poor due to high total dissolved solids (TDS) and soluble salt content. However, it is relatively free of trace metals, trinitrotoluene (TNT), cyclotrimethylenetrinitramine (RDX), and trace organics.
It is recommended that these ponds be closed and that appropriate post-closure maintenance and monitoring, as mandated under the Resource Conservation and Recovery Act, be implemented.
Application of Site-Specific Hazard Assessment Testing to Solid Wastes
Authors: Lee GF , Jones RA 
Published: March 2009

The U.S. Environmental Protection Agency (U.S. EPA) proposes to use a leaching test as one of the criteria for estimating the environmental hazard of on-land disposal of hazardous wastes. There are many significant technical problems with the specific protocols proposed for use, such as not specifying a defined redox condition under which the tests are to be conducted. The most significant deficiency is in the proposed method for interpretation of leaching test results. The use of these tests as currently formulated could readily result in chemicals that present minimal risk to the environment and human health, being classified as hazardous. More importantly, their use could cause truly hazardous wastes to be classified as acceptable for on-land disposal with minimum restrictions. Adopting the U.S. EPA's proposed approach will result in unnecessarily large amounts of money being spent for control of “hazardous” chemicals and, in some cases, without providing adequate environmental or human health protection.
This paper reviews some of the problems associated with the use of the U.S. EPA Resource Conservation and Recovery Act (RCRA) leaching test for classifying the hazardous nature of chemicals destined for land disposal. Recommendations are made for modification of the RCRA leaching test, to provide for a site-specific evaluation procedure to more properly evaluate the potential hazard associated with on-land disposal of hazardous wastes. An approach is discussed which combines environmental physics (transport and mixing), chemistry-fate, and biology (toxicology, bioconcentration) information. This approach is presented as a basis for interpretation of the results of the leaching tests in terms of the hazard associated with the disposal of a particular waste at a particular site. This “hazard assessment approach,” which has been adapted for application to solid wastes by the authors, is a sequential, selective testing-interpretation scheme for combining information on environmental physics (transport and mixing), chemistry-fate, and biology (toxicology and bioconcentration) of a waste and disposal site to determine potential environmental hazard.
Processing and Mechanical Properties of Investment Cast Ti-6Al-4V ELI Alloy for Surgical Implants: A Progress Report
Authors: Smickley RJ , Bednarz LP 
Published: March 2009

Recent advancements in the production of titanium alloy investment castings have enabled manufacturers to offer high-integrity net-shape components. Effective material utilization and attractive lead times for providing a finished product have fostered a growing interest in applying cast titanium technology to the production of surgical implant devices.
Howmet Turbine Components Corp., a major producer of titanium castings for the aerospace industry, is currently evaluating the potential of investment cast Ti-6Al-4V ELI alloy [ASTM Specification for Titanium 6Al-4V ELI Alloy for Surgical Implant Applications (F 136-79)] for surgical implant devices. Manufacturing processes such as hot isostatic pressing (HIP) and weld repair, vital to production of net-shape titanium alloy castings, have been evaluated for cast Ti-6Al-4V ELI material. Smooth and notched tensile properties, as well as impact and fatigue strength, have been investigated with favorable results.
Behavior of Commercially Pure Titanium and Ti-318 (Ti-6Al-4V) in Orthopedic Implants
Authors: Dobbs HS , Scales JT 
Published: March 2009

At the Royal National Orthopaedic Hospital major replacement of long bones began in 1949, and the first titanium-containing endoprosthesis was inserted in 1964. By now over 250 titanium-containing endoprostheses of various kinds have been inserted. Most of these components were made on a modular basis and included sections of cast cobalt-chromium-molybdenum alloy. In 1972 titanium alloy 318 (Ti-318)(Ti-6Al-4V) was introduced, and this alloy largely replaced the previously used commercially pure titanium.
This paper presents our experiences with these endoprostheses, with titanium total hip replacements, and with other titanium devices. Using standard statistical methods, survival curves for the nonremoval of the component were obtained. These curves demonstrated that the performance of upper femoral, lower femoral, and upper tibial endoprostheses was slightly worse than that of standard total hip replacements. This worse performance was a result of five intramedullary stem fractures, but we now think that this problem has been overcome by the introduction of Ti-318. These and other fractures emphasize the importance of good design, good surface finish, and optimum stem or section size. There was no evidence that the combination within a single implant of cobalt-chromium-molybdenum and titanium, commercially pure or alloy, caused corrosion or clinically significant problems. Although blackening of adjacent tissue has been observed, there was no evidence that this was associated with an undesirable tissue response.
An Evaluation of the Sandwich Beam Compression Test Method for Composites
Authors: Shuart MJ 
Published: March 2009

This report evaluates the sandwich beam in four-point bending as a compression test method for advanced composites. To accomplish this evaluation the test method was used to obtain preliminary compressive design data for the temperature range 117 to 589 K (−250 to 600°F) and was analyzed to determine any influence from the honeycomb core on composite mechanical properties. The [08], [908], [(±45)2]s, and [0/±45/90]s laminate orientations were investigated utilizing HTS1/PMR-15 graphite/polyimide composite material.
The experimental and analytical results indicated that the test method can be used to obtain compressive elastic constants for graphite/polyimide composites. Elastic data were obtained for a wide temperature range, although many failures were initiated by either load concentrations or top cover debonds. The analysis indicated that the honeycomb core had negligible effects on composite mechanical properties. The top cover carried essentially all the compressive load in the beam test section, and the stress state in the test section of the top cover was essentially uniform and uniaxial.
Mechanical Property Characterization of Intraply Hybrid Composites
Authors: Chamis CC , Lark RF , Sinclair JH 
Published: March 2009

An investigation was conducted to characterize the mechanical properties of intraply hybrids made from graphite fiber/epoxy matrix (primary composites) hybridized with varying amounts of secondary composites made from S-glass or Kevlar 49 fibers. The tests were conducted using thin laminates having the same thickness. The specimens for these tests were instrumented with strain gages to determine stress-strain behavior. The results show that the mechanical properties of intraply hybrid composites can be measured using available test methods such as the 10-deg off-axis method for intralaminar shear, and conventional test methods for tensile, flexure, and Izod impact properties. Intraply hybrids have linear stress-strain curves to fracture for longitudinal tension and nonlinear stress-strain curves for intralaminar shear.
The results also showed that combinations of high-modulus graphite/S-glass/epoxy matrix composites exist which yield intraply hybrid laminates with the “best” balanced properties: for example, 100 percent increase in impact resistance and 35 percent increase in tensile and flexural strengths, with no reduction in modulus compared with graphite fiber/epoxy matrix composites. In addition, the results showed that the translation efficiency of mechanical properties from the constituent composites to intraply hybrids may be assessed using a simple equation.
Reliability of Fatigue Testing
Authors: Young L , Ekvall JC 
Published: March 2009

A statistical analysis was performed on fatigue test data for aluminum, titanium, steel, and nickel materials. The data for the titanium, steel, and nickel were obtained from spectrum fatigue tests, whereas the data for aluminum were obtained from both constant amplitude and spectrum fatigue tests. The analyzed data consisted of a total of 553 S-N test groups with 2417 specimens and 1288 spectrum test groups with approximately 5000 specimens.
The distribution of logarithmic standard deviation of fatigue life for these test groups was analyzed with normal, logarithmic, and two-parameter Weibull probability distribution functions and with 2-deg polynominal equations. The best fit was evaluated using the coefficient of correlation and the chi-squared goodness of fit test. None of the distribution functions or polynomial equations provided the best fit for all of the distributions of the logarithmic standard deviation of fatigue life for the selected sets of test groups. A comparison is also made of three methods of calculating scatter factors.
Statistical Fatigue Properties of Some Heat-Treated Steels for Machine Structural Use
Authors: Nishijima S 
Published: March 2009

A practical method for establishing the P-S-N diagram is proposed. The method is essentially based on consideration of the distribution of strength deviation values for individual test data determined against the mean S-N curve of the population. Thus an S-N curve for 1 percent failure probability can be derived from the fatigue test results using 100 specimens.
A series of statistically planned fatigue tests was conducted according to the proposed method, in order to obtain basic fatigue data about different materials most commonly used in mechanical industries. This paper deals with the results for some typical carbon and low-alloy steels with different heat treatments, the tests being on smooth specimens in rotating bending, and discusses the variation in statistical properties between materials.
Survey of Gas Turbine Synthetic Liquid Fuels
Authors: Amero RC , DeCorso SM , Thomas RL 
Published: March 2009

As the United States moves toward an alternative fuel economy, away from petroleum fuels, gas turbines fueled by nonpetroleum sources are expected to supply an increasing percentage of the total generation of power. New technology and procurement standards need to be developed for these alternative fuels to ensure an operable, economical turbine-fuel system.
Recognizing this need, Subcommittee B133.7 on Gas Turbine Fuel Procurement Standards, a subcommittee of the American National Standards Institute (ANSI), carried out a survey to establish a technical framework for interpreting the projected properties of synthetic fuels for gas turbine applications. The 55 responses received from synthetic liquid fuel producers, equipment manufacturers, turbine users, and consultants, as well as government and nongovernment agencies, showed that process developers, gas turbine manufacturers, and users are actively involved in planning for future synthetic fuels. While the quality and properties of synthetic liquid fuels were not fully established, it is clear that methanol and distillate fuels derived from shale, coal, and tar sands are being seriously developed and will play a major role in future gas turbine operation.
Corrosion of Fuel Handling System Materials by Coal-Derived Liquid Fuels
Authors: Doering HvonE , Haskell RW , Michelfelder T 
Published: March 2009

During a gas turbine test program requiring large volumes of coal-derived liquid fuel, creosote oil, used as a substitute liquid coal synthetic fuel, caused metal corrosion in some of the fuel handling and storage components.
A subsequent laboratory test program with creosote oil and several coal liquid synthetic fuels showed that the lower boiling grades were corrosive to copper and somewhat corrosive to brass and zinc. These metals often are used in fuel pumps, flow dividers, and valves. The corrosion rate was higher with dynamic flow conditions than with static conditions. Iron was only slightly attacked by creosote oil in these tests.
Synthetic Fuels for Stationary Gas Turbines: A California Perspective
Authors: Anderson SJ , Jackson MD , Smith KD 
Published: March 2009

The state of California currently depends extensively on imported oil and natural gas from other states and foreign countries. To ensure uninterrupted service to industrial and utility company engines, alternative fuels to petroleum are being investigated. Sponsored by the California Energy Commission, an evaluation was conducted by the Acurex Corp. of coal and coal-based fuels for use in stationary gas turbines. A broad range of coal-derived solids, gases, and liquids is reviewed in this paper. Candidate fuels are identified which do not affect engine operation or exceed California environmental regulations—particularly for nitrogen oxides (NOx) pollutants.
Beneficiated coals, which contain significant amounts of ash, cause unacceptable turbine blade erosion and corrosion problems. Therefore, coal solids cannot be considered viable turbine fuels at this time. However, many gas and liquid synthetic fuels exhibit handling and combustion characteristics similar to those of petroleum fuels. Only minor hardware modifications are necessary to burn these fuels. For fuels with high nitrogen content, such as unhydrotreated direct liquids, advanced combustors are required to control NOx emissions and to meet California's stringent environmental standards.
Methanol was selected as the preferred synthetic fuel. Methanol produces low emissions and requires only minor equipment changes. Testing is under way to quantify methanol's NOx emission characteristics.
Direct-Contact Cell-Culture Method
Authors: Smith LM 
Published: March 2009

A direct-contact cell-culture test method has been developed to provide routine lot-to-lot biological assurance as a part of the quality assurance program during the manufacture and distribution of medical materials and sterile-packaged human-implant devices. It is particularly useful for detecting trace ethylene oxide or catalyst residuals. The method has also been used routinely to provide a first biocompatibility evaluation of proposed new materials or formulation.
Specimens are placed in direct contact with human fibroblastic cells grown to a confluent monolayer. The results are evaluated microscopically after 24 h incubation, using appropriate positive and negative controls. An alteration in cellular morphology is considered a cytopathic effect (CPE). Implant materials and devices are approved by the quality assurance department only if they produce no CPE in this test.
This test method has been used continuously in the lot-to-lot quality assurance program at Dow Corning's Medical Products Plant for more than ten years and has provided a fast, reliable, highly sensitive, and inexpensive method for evaluation of biocompatibility.
Test Method for Human Cell-Culture Elution to Evaluate Medical Materials and Devices for Cytotoxicity
Authors: Ettorre LM , Phillips K 
Published: March 2009

Tissue-culture testing used for screening selected new-components as well as for lot-to-lot testing of designated incoming materials before approval for use is performed routinely by the employees of the Microbiology Department at Extracorporeal, Inc. The “extraction method,” which uses the WI-38 cell line, is used most often. MRC-5 cells, a similar cell line, are also maintained as an alternate.
Materials are extracted on a surface area or weight ratio basis at 37°C for 24 h. The growth media is aspirated from the plates, replaced with extracting media, and incubated at 37°C for 24 h. Plates are stained, dried, and examined under a light microscope. Cytotoxicity is scored on a scale of 0 (negative response) to 4 (more than 75% of cells morphologically changed). Results of +2 to +4 are considered cytotoxic. Retesting is done to verify cytotoxic results.
Primary Acute Toxicity Screen for Biomaterials: Rationale, In Vitro/In Vivo Relationship and Interlaboratory Performance
Authors: Dillingham EO 
Published: March 2009

Correlation analysis of in vitro and in vivo toxic response to biomaterials, based on tests done directly on the materials and the material extracts (water, saline, polyethylene glycol-400, and cottonseed oil), demonstrated significant in vitro/in vivo correlations. In vitro tests that most strongly correlated with in vivo tests were inhibition of cell growth, hemolysis, and agar overlay tissue culture (zone index for test directly on the material). In vivo tests that most strongly correlated with in vitro tests were intradermal irritation (cottonseed oil and polyethylene glycol-400 extracts), systemic toxicity (cottonseed oil and polyethylene glycol-400 extracts of high toxicity materials), and intramuscular implantation (gross rating of the material implant). In vitro and in vivo toxicity ratings were correlated with histopathologic tissue response to material implants (necrosis [coagulative necrosis and overall degree of necrosis], inflammatory cellular infiltrates [polymorphonuclear leukocytes, macrophages, and giant cells], and fibroendothelial proliferation), although the correlations were lower than for the primary screen tests per se.
Interlaboratory performance of the primary screen indicated a useful degree of discrimination of the toxicity of different materials; all laboratories ranking the test materials in the same order with respect to toxicity. Significant differences in the absolute toxicity ratings among laboratories indicated that laboratory performance with respect to standard reference materials will be required for meaningful comparison of toxicity ratings from different laboratories.
Exploitable Characteristics of Neophobia and Food Aversions for Improvements in Rodent and Bird Control
Authors: Reidinger RF , Mason JR 
Published: March 2009

Rodent and bird pests display a variety of behavioral defenses against dietary poisoning that could be exploited for improvement in control. Such defenses include neophobia, primary food aversion, and learned food aversion. Particularly with pest birds, social learning can also facilitate the transfer of learned aversions. With the rodents studied, taste appears critical for the defensive behaviors, whereas, with birds, visual or visual/taste cues appear more important.
With pest rodents, objective assessments of taste properties of rodenticides and baits could lead to improved formulations and methodology for objectively evaluating masking agents, microencapsulation, and prebaits. Assessment of the potential of a rodenticide as an unconditioned stimulus in food aversion learning, of the bait as a conditioned stimulus, and of other attributes such as generalization of learned aversions and conditioned stimulus/unconditioned stimulus intervals could lead to improved baits, baiting systems, and repellents. Weaknesses in the behaviors (for example, continuation of grooming in the presence of the defenses) might also be further exploited in rodent control.
With pest birds, Batesian mimicry probably offers advantages over food aversion learning as the conceptual basis of repellency. Use of visual cues with repellents such as methiocarb might improve aversion learning. Differential responses of the common chemical sense in birds and mammals to some compounds (such as dimethyl anthranilate) might also be used to advantage in some control situations.
Use of Outdoor Pens in Evaluating Field Efficacy of Rodenticides
Authors: Daniel Ashton A , McCumber JH , Jackson WB 
Published: March 2009

While laboratory efficacy testing of commensal rodenticides is essential in the development of a compound, this environment does not represent the “real world” of rodent control. Thus testing under actual-use conditions is necessary. However, such field tests may be seriously compromised by peripheral, nonexposed animals moving into an area immediately after rodenticide exposure.
When information necessary for rodenticide development, formulation, or reregistration does not warrant a full-scale field trial, a simulated field trial, using an out-door pen, may be applicable. It offers a small but restricted population of rodents [such as house mice (Mus musculus) or white-footed mice (Peromyscus leucopus)] and is less expensive.
Pen trials are confined field trials, limited in scope, subject to normal weather conditions, yet with environmental controls more akin to those of laboratory testing. Outdoor mouse pens, with harborage and food, enable introduced animals to establish a reproductively active population, which the investigator can regulate; and sensitive index methods can be utilized to monitor population density and activity.
Penned areas (about 232 m2) served as the test sites. Pen walls (aluminum sheet metal) extended 20 cm into a stone trench and 51 cm above the ground. A 1-m-wide grass strip on the interior perimeter was kept mowed to deter mice from moving near the perimeter wall. An area outside the pen also was mowed. Straw bales were placed within the pen, and grass and weeds were allowed to grow, the combination providing excellent harborage for mice.
Wild house mice released in the pen were allowed to acclimate to the surroundings for at least 30 days. Sherman live traps were placed along both sides of the pen perimeter for monitoring rodent movement into or out of the test area. Large Tomahawk live traps also were placed along the exterior pen wall to protect against ground predators.
Pens of this nature can be used for determining rodenticide efficacy, the comparative testing of rodenticides, or comparing population indexes with populations of known size. Such pens also constitute an investigative tool to study population responses to a rodenticide or bait formulation.