Collection
Office of Scientific & Technical Information Technical Reports
7,927
Texas State Publications
238
Congressional Research Service Reports
144
Texas Attorney General Opinions
143
Texas Register
73
Government Accountability Office Reports
63
Texas State Auditor's Office: Reports
24
Federal Communications Commission Record
23
Technical Report Archive and Image Library
20
Office of Technology Assessment
9
7 More
Country
States
Decade
Month
Language
8,687 Matching Results
Results open in a new window/tab.
Results:
1 - 24 of
8,687
next
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.
Object Type:
Report
System:
The UNT Digital Library
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.
Object Type:
Report
System:
The UNT Digital Library
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.
Object Type:
Report
System:
The UNT Digital Library
Theoretical modeling and experimental characterization of planar defects in Y sub 2 Ba sub 4 Cu sub 6+x O sub 14+x
Crystallographic defects and phase transformations in the system Y{sub 2}Ba{sub 4}Cu{sub 6 + x}O{sub 14 + x}(0{le}{times}{le}4) are investigated by high resolution transmission electron microscopy (TEM) and static lattice, three dimensional Monte Carlo computer simulations. High resolution images of partially transformed (x = 2 to x = 1) material reveal a prevalence of CuO planar defects (stacking faults) associated with the transformation and an absence of disturbance to the perovskite Ba-Y-Ba blocks. An atomic mechanism involving the intercalculation and removal of extra CuO planes by partial dislocation climb, and requiring only a-b plane diffusion, is developed for the formation of such planar defects during changes in the layered YBaCuO crystal structure. Monte Carlo simulations based on the proposed transformation mechanism accurately reproduce the observed defects and known equilibrium structures. 24 refs., 4 figs.
Date:
November 1, 1990
Creator:
Burmester, C. P.; Fendorf, M.; Gronsky, R. & Wille, L. T.
Object Type:
Article
System:
The UNT Digital Library
Framework for control system development
Control systems being developed for the present generation of accelerators will need to adapt to changing machine and operating state conditions. Such systems must also be capable of evolving over the life of the accelerator operation. In this paper we present a framework for the development of adaptive control systems.
Date:
November 1, 1991
Creator:
Cork, C. & Nishimura, Hiroshi.
Object Type:
Article
System:
The UNT Digital Library
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.
Object Type:
Report
System:
The UNT Digital Library
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.
Object Type:
Report
System:
The UNT Digital Library
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.
Object Type:
Report
System:
The UNT Digital Library
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.
Object Type:
Report
System:
The UNT Digital Library
Annual review of cultural resource investigations by the Savannah River Archaeological Research Program, fiscal year 1990
The Savannah River Archaeological Research Program (SRARP) of the South Carolina Institute of Archaeology and Anthropology, University of South Carolina, is funded through a direct contract with the United States Department of Energy to provide services required under federal law for the protection and management of archaeological resources on the Savannah River Site (SRS). Because the significance of most archaeological resources is dependent upon research potential, the SRARP is guided by research objectives. An on-going research program provides the problems, methods and means of assessing site significance within the compliance process specified by law. In addition, the SRARP maintains an active program of public education to disseminate knowledge about prehistory and history, and to enhance public awareness about historic preservation. The following report summarizes the management, research and public education activities of the SRARP during Fiscal Year 1990.
Date:
November 1, 1990
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
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.
Object Type:
Report
System:
The UNT Digital Library
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))
Object Type:
Report
System:
The UNT Digital Library
Tempered glass
This document describes a demonstration for making tempered glass using minimal equipment. The demonstration is intended for a typical student of materials science, at the high school level or above. (JL)
Date:
November 1, 1991
Creator:
Bunnell, L.R.
Object Type:
Article
System:
The UNT Digital Library
Monte Carlo optimization of depth-of-interaction resolution in PET crystals
The light distribution along one edge of a PET scintillation crystal was investigated with a Monte Carlo simulation. This position-dependent light can be used to measure the 511 keV photon interaction position in the crystal on an event by event basis, thus reducing radial elongation. The expected full width at half maximum (FWHM) of the light distribution on the 3 {times} 30 mm{sup 2} surface of a 3 {times} 10 {times} 30 mm{sup 3} bismuth germanate (BGO) crystal surrounded by a diffuse reflector was determined to be 3.0 mm. This light distribution does not change as the width (originally 3 mm) is varied from 1 to 6 mm, but decreases monotonically from 3.0 to 1.8 mm FWHM as the height (originally 10 mm) is reduced to 3 mm. Other geometrical modifications were simulated, including numerous corner reflectors on the opposing 3 {times} 30 mm{sup 2} surface, which reduced the FWHM to 2.4 mm. The response of a dual wedge photodiode combined with the predicted light distribution for the 3 {times} 10 {times} 30 mm{sup 3} BGO simulation crystal results in an expected depth of interaction resolution of 7.5 mm FWHM.
Date:
November 1, 1991
Creator:
DeVol, T. A. (Michigan Univ., Ann Arbor, MI (United States). Dept. of Nuclear Engineering); Moses, W. W. & Derenzo, S. E. (Lawrence Berkeley Lab., CA (United States))
Object Type:
Article
System:
The UNT Digital Library
Numerical simulations of heterogeneous chemical reactions coupled to fluid flow in varying thermal fields
A numerical simulator of reactive chemical transport with coupling from precipitation-dissolution reactions to fluid flow, via changes of porosity and permeability, is applied to precipitation-dissolution of quartz and calcite in spatially and temporally variable fields of temperature. Significant effects on fluid flow are found in the quartz-silicic acid system in the presence of persistent, strong gradient of temperature. Transient heat flow in the quartz-silicic acid system and in a calcite-calcium ion-carbonato species system produces vanishingly small effects on fluid flow.
Date:
November 1, 1991
Creator:
Carnahan, C.L.
Object Type:
Article
System:
The UNT Digital Library
Controlled Synthesis of Polyenes by Catalytic Methods. Progress Report for the period December 1, 1989 - November 30, 1992
A more direct approach to polyenes by the direct polymerization of acetylenes has been achieved. We were able to show that polymerization of acetylene itself can be controlled with a well- characterized alkylidene catalyst, but only if a base such as quinuclidine is present in order to slow down the rate of propagation relative to initiation. (Quinuclidine may also stabilize vinylalkylidene intermediates formed in the reaction). Unfortunately, living polyenes'' were no more stable than isolated polyenes, and so this approach had its limitations. Direct polymerization of acetylene by Mo(CH-t-Bu)(NAr)(O-t-Bu){sub 2} was more successful, but inherent polyene instability was still a problem. The most important result of the past grant period is the finding that dipropargyl derivatives (HC=CCH{sub 2}XCH{sub 2}C=CH; X = CH{sub 2}, C(CO{sub 2}R){sub 2}, SiR{sub 2}, etc.), which have been reported to be cyclopolymerized by various classical catalysts by as yet unknown mechanisms, are polymerized by Mo(CH-t-Bu)(NAr)(OCMe(CF{sub 3}){sub 2}){sub 2} in dimethoxyethane. We speculate that intramolecular formation of a five-membered ring in the product of {alpha} addition is fast enough to yield another terminal alkylidene on the time scale of the polymerization reaction, while a six-membered ring is formed in a reaction involving a more reaction terminal alkylidene. …
Date:
November 30, 1992
Creator:
Schrock, R. R.
Object Type:
Report
System:
The UNT Digital Library
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))
Object Type:
Report
System:
The UNT Digital Library
Very intense pulse in the groundwater flow in fissurized-porous stratum
None
Date:
November 1, 1999
Creator:
Barenblatt, G.I.; Ingerman, E.A.; Shvets, H. & Vazquez, J.L.
Object Type:
Article
System:
The UNT Digital Library
Review of CERN heavy-ion physics
Results from the heavy-ion experiments at the CERN SPS are reviewed in the context of possible formation and identification of a quark-gluon plasma (QGP).
Date:
November 1, 1991
Creator:
Odyniec, G.
Object Type:
Article
System:
The UNT Digital Library
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.
Object Type:
Report
System:
The UNT Digital Library
D0 papers on B-physics submitted to DPF '96: b-quark inclusive cross sections and b anti-b correlations using dimuons from the D0 experiment; Single muon production in the forward region at [radical]s=1. 8 TEV; Rapidity dependence of the inclusive J[psi] production in the forward region [radical]s=1. 8 TEV; A search for b [r arrow] X[mu][sup +][mu][sup [minus]] and B[sup 0] [r arrow] [mu][sup +][mu][sup [minus]] decays in p anti-p collisions at [radical]s=1. 8 TEV
Paper 1: Using dimuons collected with the D0 detector during the 1993--1995 Tevatron collider run, the authors have measured the b-quark cross section and b[anti b] correlations as given by the difference in azimuthal angle between the two muons. Both measurements agree with the NLO QCD predictions within experimental and theoretical errors. (Three other papers are included in this report.)
Date:
November 1, 1996
Creator:
Vititoe, D.L. (Arizona Univ., Tucson, AZ (United States). Dept. of Physics); Kozelov, Alexander; Jesik, Richard & Collaboration., D0
Object Type:
Article
System:
The UNT Digital Library
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.
Object Type:
Report
System:
The UNT Digital Library
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.
Object Type:
Report
System:
The UNT Digital Library
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.
Object Type:
Report
System:
The UNT Digital Library