Resource Type

Titanium/gold process characterization (open access)

Titanium/gold process characterization

Characterization of the titanium/gold (Ti/Au) deposition process used at the Allied-Signal Inc., Albuquerque Microelectronics Operation (AMO) was performed. Tests were conducted to set up evaporation parameters, correlate titanium and gold thicknesses to sheet resistance, improve thickness uniformity, and reduce frontside contamination of deposit material on product wafers. The Ti/Au process is the final step in the production of integrated circuits (ICs) at the AMO wafer fabrication facility. 3 figs.
Date: November 1, 1991
Creator: Fajardo, L.S.
System: The UNT Digital Library
Polysaccharides and bacterial plugging (open access)

Polysaccharides and bacterial plugging

Before any successful application of Microbial Enhanced Oil Recovery process can be realized, an understanding of the cells' transport and retentive mechanisms in porous media is needed. Cell transport differs from particle transport in their ability to produce polysaccharides, which are used by cells to adhere to surfaces. Cell injection experiments have been conducted using Leuconostoc cells to illustrate the importance of cellular polysaccharide production as a transport mechanism that hinders cell movement and plugs porous media. Kinetic studies of the Leuconostoc cells, carried out to further understand the plugging rates of porous media, have shown that the cells' growth rates are approximately equal when provided with monosaccharide (glucose and fructose) or sucrose. The only difference in cell metabolism is the production of dextran when sucrose is supplied as a carbon source. Experimentally it has also been shown that the cells' growth rate is weakly dependent upon the sucrose concentration in the media, and strongly dependent upon the concentration of yeast extract. The synthesis of cellular dextran has been found to lag behind cell generation, thus indicating that the cells need to reach maturity before they are capable of expressing the detransucrase enzyme and synthesizing insoluble dextran. Dextran yields were …
Date: November 1, 1991
Creator: Fogler, H. S.
System: The UNT Digital Library
Mass and energy budgets of animals: Behavioral and ecological implications (open access)

Mass and energy budgets of animals: Behavioral and ecological implications

The two major aims of our lab are as follows: First, to develop and field-test general mechanistic models that predict animal life history characteristics as influenced by climate and the physical, physiological behavioral characteristics of species. This involves: understanding how animal time and energy budgets are affected by climate and animal properties; predicting growth and reproductive potential from time and energy budgets; predicting mortality based on climate and time and energy budgets; and linking these individual based models to population dynamics. Second to conduct empirical studies of animal physiological ecology, particularly the effects of temperature on time and energy budgets. The physiological ecology of individual animals is the key link between the physical environment and population-level phenomena. We address the macroclimate to microclimate linkage on a broad spatial scale; address the links between individuals and population dynamics for lizard species; test the endotherm energetics and behavior model using beaver; address the spatial variation in climate and its effects on individual energetics, growth and reproduction; and address patchiness in the environment and constraints they may impose on individual energetics, growth and reproduction. These projects are described individually in the following section. 24 refs., 9 figs.
Date: November 1, 1991
Creator: Porter, W.P.
System: The UNT Digital Library
Modeling requirements for in situ vitrification (open access)

Modeling requirements for in situ vitrification

This document outlines the requirements for the model being developed at the INEL which will provide analytical support for the ISV technology assessment program. The model includes representations of the electric potential field, thermal transport with melting, gas and particulate release, vapor migration, off-gas combustion and process chemistry. The modeling objectives are to (1) help determine the safety of the process by assessing the air and surrounding soil radionuclide and chemical pollution hazards, the nuclear criticality hazard, and the explosion and fire hazards, (2) help determine the suitability of the ISV process for stabilizing the buried wastes involved, and (3) help design laboratory and field tests and interpret results therefrom.
Date: November 1, 1991
Creator: MacKinnon, R.J.; Mecham, D. C.; Hagrman, D. L.; Johnson, R. W.; Murray, P. E.; Slater, C. E. et al.
System: The UNT Digital Library
Lung cancer epidemiology in New Mexico uranium miners (open access)

Lung cancer epidemiology in New Mexico uranium miners

This investigation assesses the health effects of radon progeny exposure in New Mexico uranium miners. Cumulative exposures sustained by most New Mexico miners are well below those received earlier in the Colorado Plateau. This project utilizes the research opportunity offered by New Mexico miners to address unresolved issues related to radon progeny exposure: (1) the lung cancer risk of lower levels of exposure, (2) interaction between radon progeny exposure and cigarette smoking in the causation of lung cancer, (3) the relationship between lung cancer histologic type and radon progeny exposure, and (4) possible effects of radon progeny exposure other than lung cancer. A cohort study of 3800 men with at least one year of underground uranium mining experience in New Mexico is in progress. Results are discussed.
Date: November 1, 1991
Creator: Samet, J.M.
System: The UNT Digital Library
Experimental evaluation of oxygen-enriched air and emulsified fuels in a single-cylinder diesel engine (open access)

Experimental evaluation of oxygen-enriched air and emulsified fuels in a single-cylinder diesel engine

This report contains the data gathered from tests conducted on a single-cylinder diesel engine to study the benefits and problems of oxygen-enriched diesel combustion and the use of water-emulsified and low-grade diesel fuels. This research, funded by the Office of Industrial Technologies (OIT) in the United States Department of Energy, is being conducted in support of the Industrial Cogeneration Program. The report is made up of two volumes. Volume 1 contains the description of the experiments, selected data points, discussion of trends, and conclusions and recommendations; Volume 2 contains the data sets. With the two-volume approach, readers can find information at the desired level of detail, depending on individual interest or need.
Date: November 1, 1991
Creator: Sekar, R.R.; Marr, W.W.; Cole, R.L. & Marciniak, T.J.
System: The UNT Digital Library
Boundary plasma transport studies on TFTR (open access)

Boundary plasma transport studies on TFTR

In this report we summarize the experimental and theoretical investigations supported under the DOE Transport Initiative Contract on the subject of Boundary Plasma Transport Studies on TFTR. This work can be logically separated into two areas of investigations and therefore the report included here is divided into two parts. First, in Section I, detailed boundary plasma data obtained from TFTR in an Ohmic density scan has been compared with results from the LIM Impurity Production and Transport Code. Second, in Section II, experimental results taken with the newly-purchased (specifically for this Initiative) intensified CCD camera are presented, which, after comparison with simple modeling, reveals a new and important effect that has implications for limiter and divertor plate design.
Date: November 1, 1991
Creator: Pitcher, C.S. & Stangeby, P.C.
System: The UNT Digital Library
Task plan for TARA-II compaction and grouting demonstration (open access)

Task plan for TARA-II compaction and grouting demonstration

This task directly supports the corrective measures evaluation for the closure of Solid Waste Storage Area (SWSA) 6 but also supports technology development for the closure of other Oak Ridge National Laboratory (ORNL) SWSAs and waste management units. Previous demonstrations have established the effectiveness of dynamic compaction and in situ grouting in stabilizing burial trenches against subsidence, which would otherwise compromise the support of infiltration barrier structures designed to protect buried waste from leaching. In situ grouting with polyacrylamide has also been demonstrated to improve the hydrologic isolation of buried waste. Both of these stabilization techniques have been demonstrated on burial trenches that are situated well above the water table and, hence, are in a chronic unsaturated moisture regime. Further demonstrations of these shallow-land burial trench stabilization techniques are necessary to establish their effectiveness and safety when applied to burial trenches that are chronically inundated with groundwater.
Date: November 1, 1991
Creator: Spalding, B. P.
System: The UNT Digital Library
Coal liquefaction process streams characterization and evaluation (open access)

Coal liquefaction process streams characterization and evaluation

This study clearly demonstrated the usefulness of liquid- and solid-state {sup 13}C- and {sup 1}H-NMR for the examination of process-derived materials from direct coal liquefaction. The techniques can provide data not directly obtainable by other methods to examine the saturation of aromatic rings and to determine the modes of hydrogen utilization during coal liquefaction. In addition, these methods can be used to infer the extent of condensation and retrograde reactions occurring in the direct coal liquefaction process. Five NMR techniques were employed. Solid-state {sup 13}C-NMR measurements were made using the Cross Polarization Magic Angle Spinning (CP/MAS) and Single Pulse (SP) techniques. Solid-state {sup 1}H-NMR measurements were made using the technique of Combined Rotation and Multiple-Pulse spectroscopy (CRAMPS). Conventional liquid-state {sup 12}C- and {sup 1}H-NMR techniques were employed as appropriate. Interpretation of the NMR data, once obtained, is relatively straightforward. Combined with other information, such as elemental analyses and process conversion data, the NMR data prove to be a powerful tool for the examination of direct coal liquefaction process-derived material. Further development and more wide-spread application of this analytical method as a process development tool is justified on the basis of these results.
Date: November 1, 1991
Creator: Miknis, F.P. (Western Research Inst., Laramie, WY (United States))
System: The UNT Digital Library
Emissions of greenhouse gases from the use of transportation fuels and electricity (open access)

Emissions of greenhouse gases from the use of transportation fuels and electricity

This report presents estimates of full fuel-cycle emissions of greenhouse gases from using transportation fuels and electricity. The data cover emissions of carbon dioxide (CO{sub 2}), methane, carbon monoxide, nitrous oxide, nitrogen oxides, and nonmethane organic compounds resulting from the end use of fuels, compression or liquefaction of gaseous transportation fuels, fuel distribution, fuel production, feedstock transport, feedstock recovery, manufacture of motor vehicles, maintenance of transportation systems, manufacture of materials used in major energy facilities, and changes in land use that result from using biomass-derived fuels. The results for electricity use are in grams of CO{sub 2}-equivalent emissions per kilowatt-hour of electricity delivered to end users and cover generating plants powered by coal, oil, natural gas, methanol, biomass, and nuclear energy. The transportation analysis compares CO{sub 2}-equivalent emissions, in grams per mile, from base-case gasoline and diesel fuel cycles with emissions from these alternative- fuel cycles: methanol from coal, natural gas, or wood; compressed or liquefied natural gas; synthetic natural gas from wood; ethanol from corn or wood; liquefied petroleum gas from oil or natural gas; hydrogen from nuclear or solar power; electricity from coal, uranium, oil, natural gas, biomass, or solar energy, used in battery-powered electric vehicles; and hydrogen …
Date: November 1, 1991
Creator: DeLuchi, M.A. (California Univ., Davis, CA (United States))
System: The UNT Digital Library
Substitute safety rods: Physics of operation and irradiation (open access)

Substitute safety rods: Physics of operation and irradiation

Under certain assumed accidents, an SRS reactor may lose most of its bulk moderator while maintaining flow to fuel assemblies. If this occurs immediately after operation at power, components normally dependent on convective heat transfer to the moderator will heat up with the possibility of melting that component. One component at risk is the currently used cadmium safety rod. A substitute safety rod consisting solely of sintered B{sub 4}C and stainless steel has been designed which is capable of withstanding much higher temperatures. This memorandum provides the physics basis for the adequacy of the rod for reactor shutdown and provides a set of criteria for acceptance in the NTG tests. This memorandum provides physics data for other aspects of operation. These include: Heat production and helium production, along with related phenomena, resulting from inadvertent irradiation at power. Gamma heat input under drained tank conditions. An equivalent rod design suitable for charge design and safety analyses. Degradation under normal operation. Thermal flux ripple in adjacent fuel due to axial striping of alternate B{sub 4}C and steel pellets. Possible effect on safety analyses. Safety rod withdrawal during reactor startup.
Date: November 18, 1991
Creator: Baumann, N.P.
System: The UNT Digital Library
Experimental evaluation of oxygen-enriched air and emulsified fuels in a single-cylinder diesel engine (open access)

Experimental evaluation of oxygen-enriched air and emulsified fuels in a single-cylinder diesel engine

The performance of a single-cylinder, direct-injection diesel engine was measured with intake oxygen levels of up to 35% and fuel water contents of up to 20%. Because a previous study indicated that the use of a less-expensive fuel would be more economical, two series of tests with No. 4 diesel fuel and No. 2 diesel fuel were conducted. To control the emissions of nitrogen oxides (NO{sub x}), water was introduced into the combustion process in the form of water-emulsified fuel, or the fuel injection timing was retarded. In the first series of tests, compressed oxygen was used; in the second series of tests, a hollow-tube membrane was used. Steady-state engine performance and emissions data were obtained. Test results indicated a large increase in engine power density, a slight improvement in thermal efficiency, and significant reductions in smoke and particulate-matter emissions. Although NO{sub x} emissions increased, they could be controlled by introducing water and retarding the injection timing. The results further indicated that thermal efficiency is slightly increased when moderately water-emulsified fuels are used, because a greater portion of the fuel energy is released earlier in the combustion process. Oxygen-enriched air reduced the ignition delay and caused the heat-release rate and …
Date: November 1, 1991
Creator: Sekar, R. R.; Marr, W. W.; Cole, R. L. & Marciniak, T. J.
System: The UNT Digital Library
Magnet operating experience review for fusion applications (open access)

Magnet operating experience review for fusion applications

This report presents a review of magnet operating experiences for normal-conducting and superconducting magnets from fusion, particle accelerator, medical technology, and magnetohydrodynamics research areas. Safety relevant magnet operating experiences are presented to provide feedback on field performance of existing designs and to point out the operational safety concerns. Quantitative estimates of magnet component failure rates and accident event frequencies are also presented, based on field experience and on performance of similar components in other industries.
Date: November 1, 1991
Creator: Cadwallader, L.C.
System: The UNT Digital Library
CNC grinding of valve housing piston holes (open access)

CNC grinding of valve housing piston holes

Grinding has traditionally been used for machining operations requiring close dimensional tolerances and better surface finishes than can be obtained from other metal removal techniques. Using a grinding process for the last metal removal operation, the close tolerances and surface finishes can be easily held while eliminating the adverse conditions from the current metal removal processes. Pre-machined test parts were sent to a machine tool supplier to have the critical inside features of a typical piston bore finish machined using an internal CNC grinder equipped with high-frequency spindles. The piston bore and sealing angle were ground using a standard 120-grit silicon carbide wheel. The wafer step was machined using a solid carbide tool designed and built at Allied-Signal Inc., Kansas City Division (KCD). Six consecutive parts were machined for evaluation. The repeatability on all six parts was within print requirements. The inside corner radii was less than 0.002 in. and the surface finish was 8.2 arithmetical average or better as defined by ANSI B46.1, Surface Texture. Machining parts by this grinding process would eliminate bellmouth, chatter, waviness, and traveler polishing operations. It would produce a superior surface finish, small inside radii, and small easily removable burrs. It would also hold …
Date: November 1, 1991
Creator: Ashbaugh, F.A.
System: The UNT Digital Library
Renewable energy data requirements: A review of user opinions and data collection efforts (open access)

Renewable energy data requirements: A review of user opinions and data collection efforts

Interest in the contribution of renewable energy to US energy supply is growing. This interest stems from environmental and energy security concerns and the desire to develop domestic resources. In order to plan for the use of renewable energy, data are essential to a variety of users both inside and outside the government. The purpose of this study is to identify priorities and requirements for gathering different types of renewable energy data. Results of this study are to be used by the US Department of Energy, Energy Information Administration (EIA), in planning and evaluating its ongoing and future renewable energy information programs. The types of renewable energy addressed in this study include biomass (wood, agricultural residues, and crops grown for energy), municipal solid waste, geothermal energy, solar energy, and wind. To assess the relative importance of different types of information, we reviewed existing renewable energy data collection efforts and asked the opinions of renewable energy data users. Individuals in government, private industry, research organizations, industry trade associations, and public interest research groups were contacted and questioned about particular renewable energy data items. An analysis of their responses provides the basis for the conclusions in this report. The types of information; …
Date: November 1, 1991
Creator: Stevenson, G.G.
System: The UNT Digital Library
Meteorological conditions during the winter validation study at Rocky Flats, Colorado: An overview (open access)

Meteorological conditions during the winter validation study at Rocky Flats, Colorado: An overview

The objective for the Winter Validation Study was to gather field data for validation of the Terrain-Responsive Atmospheric Code (TRAC) under winter time meteorological conditions. Twelve tracer tests were conducted during a two-week period in February 1991. Each test lasted 12 hours, with releases of SF{sub 6} tracer from the Rocky Flats Plant near Golden, Colorado. The tests included ground-based and airborne sampling to 16 km from the release point. This presentation summarizes meteorological conditions during the testing period. Forty six viewgraphs are included.
Date: November 6, 1991
Creator: Hodgin, C.R.
System: The UNT Digital Library
Nuclear magnetic resonance studies of the regulation of the pentose phosphate pathway (open access)

Nuclear magnetic resonance studies of the regulation of the pentose phosphate pathway

The goal of this work is to investigate the potential for and limitations of in vivo nuclear magnetic resonance (NMR) spectroscopy for quantitation of glucose flux through the pentose phosphate pathway (shunt). Interest in the shunt is motivated by the possibility that its activity may be greatly increased in cancer and in the pathological states of cardiac and cerebral ischemia. The ability to dynamically monitor flux through the pentose shunt can give new knowledge about metabolism in pathological states. {sup 13}C NMR spectroscopy was used to monitor shunt activity by determination of the ratios of ({sup 13}C-4) to ({sup 13}C-5)-glutamate, ({sup 13}C-3) to ({sup 13}C-2)-alanine or ({sup 13}C-3) to ({sup 13}C-2)-lactate produced when ({sup 13}C-2)-glucose is infused. These methods provide measures of the effect of oxidative stresses on shunt activity in systems ranging from cell free enzyme-substrate preparations to cell suspensions and whole animals. In anaerobic cell free preparations, the fraction of glucose flux through the shunt was monitored with a time resolution of 3 minutes. This work predicts the potential for in vivo human studies of pentose phosphate pathway activity based on the mathematical simulation of the {sup 13}C fractional enrichments of C4 and C5-glutamate as a function of …
Date: November 1, 1991
Creator: Bolo, N.R.
System: The UNT Digital Library
Coal-fueled high-speed diesel engine development (open access)

Coal-fueled high-speed diesel engine development

The objectives of this program are to study combustion feasibility by running Series 149 engine tests at high speeds with a fuel injection and combustion system designed for coal-water-slurry (CWS). The following criteria will be used to judge feasibility: (1) engine operation for sustained periods over the load range at speeds from 600 to 1900 rpm. The 149 engine for mine-haul trucks has a rated speed of 1900 rpm; (2) reasonable fuel economy and coal burnout rate; (3) reasonable cost of the engine design concept and CWS fuel compared to future oil prices.
Date: November 1, 1991
Creator: unknown
System: The UNT Digital Library
Water-enhanced solubility of carboxylic acids in organic solvents and its applications to extraction processes (open access)

Water-enhanced solubility of carboxylic acids in organic solvents and its applications to extraction processes

The solubilities of carboxylic acids in certain organic solvents increase remarkably with an increasing amount of water in the organic phase. This phenomenon leads to a novel extract regeneration process in which the co-extracted water is selectively removed from an extract, and the carboxylic acid precipitates. This approach is potentially advantageous compared to other regeneration processes because it removes a minor component of the extract in order to achieve a large recovery of acid from the extract. Carboxylic acids of interest include adipic acid, fumaric acid, and succinic acid because of their low to moderate solubilities in organic solvents. Solvents were screened for an increase in acid solubility with increased water concentration in the organic phase. Most Lewis-base solvents were found to exhibit this increased solubility phenomena. Solvents that have a carbonyl functional group showed a very large increase in acid solubility. 71 refs., 52 figs., 38 tabs.
Date: November 1, 1991
Creator: Starr, J. N. & King, C. J.
System: The UNT Digital Library
Development of an advanced continuous mild gasification process for the production of coproducts (open access)

Development of an advanced continuous mild gasification process for the production of coproducts

This report is a final brief summary of development of a mild-gasification and char conversion process. Morgantown Energy Technology Center developed a concept called mild gasification. In this concept, devolatilization of coal under nonoxidizing and relatively mild temperature and pressure conditions can yield three marketable products: (1) a high-heating-value gas, (2) a high-aromatic coal liquid, and (3) a high-carbon char. The objective of this program is to develop an advanced, continuous, mild-gasification process to produce products that will make the concept economically and environmentally viable. (VC)
Date: November 1, 1991
Creator: Merriam, N. W. & Jha, M. C.
System: The UNT Digital Library
Automated Insertion of Sequences into a Ribosomal RNA Alignment: an Application of Computational Linguistics in Molecular Biology (open access)

Automated Insertion of Sequences into a Ribosomal RNA Alignment: an Application of Computational Linguistics in Molecular Biology

This thesis involved the construction of (1) a grammar that incorporates knowledge on base invariancy and secondary structure in a molecule and (2) a parser engine that uses the grammar to position bases into the structural subunits of the molecule. These concepts were combined with a novel pinning technique to form a tool that semi-automates insertion of a new species into the alignment for the 16S rRNA molecule (a component of the ribosome) maintained by Dr. Carl Woese`s group at the University of Illinois at Urbana. The tool was tested on species extracted from the alignment and on a group of entirely new species. The results were very encouraging, and the tool should be substantial aid to the curators of the 16S alignment. The construction of the grammar was itself automated, allowing application of the tool to alignments for other molecules. The logic programming language Prolog was used to construct all programs involved. The computational linguistics approach used here was found to be a useful way to attach the problem of insertion into an alignment.
Date: November 1991
Creator: Taylor, Ronald C.
System: The UNT Digital Library
Use of noninvasive geophysical techniques for the In Situ Vitrification Program (open access)

Use of noninvasive geophysical techniques for the In Situ Vitrification Program

This document is the second volume of a three volume report to evaluate geophysical methods for use in the detailed characterization of waste pits. The In Situ Vitrification (ISV) Program funded the study to support the ISV remediation technology being developed at the Idaho National Engineering Laboratory (INEL). The ISV Program is considering geophysical waste characterization as a means to enhance the efficiency of the ISV process. Field tests were conducted to demonstrate and evaluate the application of magnetic, electromagnetic induction, and ground penetrating radar methods to waste site characterization. The primary objective was to investigate the ability of these noninvasive geophysical methods to locate and identify buried waste materials under conditions representative of the INEL Subsurface Disposal Area (SDA). The tests were conducted at an simulated waste pit designed to represent conditions at the SDA.
Date: November 1, 1991
Creator: Marts, S.T.; Josten, N.E. & Carpenter, G.S.
System: The UNT Digital Library
A surface science investigation of silicon carbide: Oxidation, crystal growth and surface structural analysis (open access)

A surface science investigation of silicon carbide: Oxidation, crystal growth and surface structural analysis

For the semiconductor SiC to fulfill its potential as an electronic material, methods must be developed to produce insulating surface oxide layers in a reproducible fashion. Auger electron spectroscopy (AES), low energy electron diffraction (LEED) and x-ray photoelectron spectroscopy (XPS) were used to investigate the oxidation of single crystal {alpha}-SiC over a wide temperature and O{sub 2} pressure range. The {alpha}-SiC surface becomes graphitic at high temperatures and low O{sub 2} pressures due to Si and SiO sublimation from the surface. Amorphous SiO{sub 2} surface layers from on {alpha}-SiC at elevated O{sub 2} pressures and temperatures. Both the graphitization and oxidation of {alpha}-SiC appears to be enhanced by surface roughness. Chemical vapor deposition (CVD) is currently the preferred method of producing single crystal SiC, although the method is slow and prone to contamination. We have attempted to produce SiC films at lower temperatures and higher deposition rates using plasma enhanced CVD with CH{sub 3}SiH{sub 3}. Scanning AES, XPS and scanning electron microscopy (SEM) were utilized to study the composition and morphology of the deposited Si{sub x}C{sub y}H{sub z} films as a function of substrate temperature, plasma power and ion flux bombardment of the film during deposition. High energy ion bombardment …
Date: November 1, 1991
Creator: Powers, J. M.
System: The UNT Digital Library
Component external leakage and rupture frequency estimates (open access)

Component external leakage and rupture frequency estimates

In order to perform detailed internal flooding risk analyses of nuclear power plants, external leakage and rupture frequencies are needed for various types of components - piping, valves, pumps, flanges, and others. However, there appears to be no up-to-date, comprehensive source for such frequency estimates. This report attempts to fill that void. Based on a comprehensive search of Licensee Event Reports (LERs) contained in Nuclear Power Experience (NPE), and estimates of component populations and exposure times, component external leakage and rupture frequencies were generated. The remainder of this report covers the specifies of the NPE search for external leakage and rupture events, analysis of the data, a comparison with frequency estimates from other sources, and a discussion of the results.
Date: November 1, 1991
Creator: Eide, S. A.; Khericha, S. T.; Calley, M. B.; Johnson, D. A. & Marteeny, M. L.
System: The UNT Digital Library