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The J-TAC (Stephenville, Tex.), Ed. 1 Thursday, April 2, 1992
Weekly student newspaper from Tarleton State University in Stephenville, Texas that includes local, state and campus news along with advertising.
Date:
April 2, 1992
Creator:
unknown
Object Type:
Newspaper
System:
The Portal to Texas History
Optical assessment of large marine particles: Development of an imaging and analysis system for quantifying large particle distributions and fluxes. Final report, June 1992--May 1996
The central goal of DOE`s Ocean Margin Program (OMP) has been to determine whether continental shelves are quantitatively significant in removing carbon dioxide from the atmosphere and isolating it via burial in sediments or exporting it to the open ocean. The overall objective of this work within OMP was to develop an instrument package to measure the large aggregate population of particles in the shelf/slope environment at a rate sufficient to integrate the observed particle distributions into the coupled physical and biogeochemical models necessary to understand the shelf and slope as a system. Pursuant to this the authors have developed a video and optical instrument package (LAPS: Large Aggregate Profiling System) and assembled the computer and software methods to routinely measure a wide spectrum of the large aggregate population of particles in the shelf/slope environment. This particle population, encompassing the `marine snow` size particles (dia. > 0.5 mm), is thought to be the major pathway of material flux in the ocean. The instrument package collects aggregate abundance and size spectrum data using two video camera/strobe subsystems with a third subsystem collecting CTD, beam attenuation and fluorescence data. Additionally, measurements of particle flux were made with sediment traps deployed on the …
Date:
April 1, 1997
Creator:
Walsh, I. D. & Gardner, W. D.
Object Type:
Report
System:
The UNT Digital Library
Scientific drilling in the Valles caldera magma-hydrothermal system, New Mexico
None
Date:
April 1, 1994
Creator:
Goff, F.; Gardner, J. N.; Heiken, G. & Hulen, J. B.
Object Type:
Report
System:
The UNT Digital Library
Preparation and evaluation of novel hydrous metal oxide (HMO)-supported noble metal catalysts
Hydrous Metal Oxides (HMOs) are chemically synthesized materials that, because of their high cation exchange capacity, possess a unique ability to allow the preparation of highly dispersed supported-metal catalyst precursors with high metal loadings. This study evaluates high weight loading Rh/HMO catalysts with a wide range of HMO support compositions, including hydrous titanium oxide (HTO), silica-doped hydrous titanium oxide (HTO:Si), hydrous zirconium oxide (HZO), and silica-doped hydrous zirconium oxide (HZO:Si), against conventional oxide-supported Rh catalysts with similar weight loadings and support chemistries. Catalyst activity measurements for a structure-sensitive model reaction (n-butane hydrogenolysis) as a function of catalyst activation conditions show superior activity and stability for the ZrO{sub 2}, HZO, and HZO:Si supports, although all of the Rh/HMO catalysts have high ethane selectivity indicative of high Rh dispersion. For the TiO{sub 2}-, HTO-, and HTO:Si supported Rh catalysts, a significant loss of both catalyst activity and Rh dispersion is observed at more aggressive activation conditions, consistent with TiO{sub x} migration associated with SMSI phenomena. Of all the Rh/HMO catalysts, the Rh/HZO:Si catalysts appear to offer the best tradeoff in terms of high Rh dispersion, high activity, and high selectivity.
Date:
April 1, 1998
Creator:
Gardner, Timothy J.; McLaughlin, Linda I.; Evans, Lindsey R. & Datye, Abhaya K.
Object Type:
Report
System:
The UNT Digital Library
Data quality objectives for generic in-tank health and safety vapor issue resolution. Revision 1
Data Quality Objectives (DQOs) for generic waste storage tank vapor and gas sampling were developed in facilitated meetings and a stakeholder review session, using the most recent US EPA DQO guidelines. These meetings elicited DQOs for two major vapor problem areas: flammability and toxicity. This is a summary of the outputs of the planning team for each of the 7 steps of the DQO process.
Date:
April 28, 1995
Creator:
Osborne, J.W.
Object Type:
Report
System:
The UNT Digital Library
Use of coal liquefaction catalysts for coal/oil coprocessing and heavy oil upgrading
The catalytic hydrogenation of coal and model solvents using dispersed or supported catalysts at different pressures has been the focus of several recent studies at PETC. The effectiveness of these catalysts has been studied in coal liquefaction and coal-oil coprocessing. Coal-oil coprocessing involves the co-reaction of coal and petroleum-derived oil or resid. The results of these studies have indicated that both dispersed and supported catalysts are effective in these systems at elevated H{sub 2} pressures ({approximately}2,500 psig). Attempts to reduce pressure indicated that a combination of catalyst concentration and solvent quality could be used to compensate for reductions in H{sub 2} pressure. Comparison of the coal and coprocessing systems reveals many similarities in the catalytic requirements for both systems. Both hydrogenation and hydrogenolysis activities are required and the reactive environments are similar. Also, the use of catalysts in the two systems shares problems with similar types of inhibitors and poisons. The logical extension of this is that it may be reasonable to expect similar trends in catalyst activity for both systems. In fact, many of the catalysts selected for coal liquefaction were selected based on their effectiveness in petroleum systems. This study investigates the use of supported and dispersed coal …
Date:
April 1, 1997
Creator:
Cugini, A. V.; Krastman, D.; Thompson, R. L.; Gardner, T. J. & Ciocco, M. V.
Object Type:
Article
System:
The UNT Digital Library
Hydrogen Production for Fuel Cells by Selective Dehydrogenation of Alkanes in Catalytic Membrane Reactors
None
Date:
April 1, 1999
Creator:
Gardner, Timothy J.; Boespflug, Elaine P.; Brinker, C. Jeffrey; Sault, Allen G.; Tsai, Andy C. Y. & Collins, John P.
Object Type:
Report
System:
The UNT Digital Library
WASP News, Volume 31, Number 1, April 1993
Newsletter of the former World War II Women Airforce Service Pilots including news, events, stories about the group's history, and other information of interest to the members.
Date:
April 1993
Creator:
Women Airforce Service Pilots (U.S.)
Object Type:
Journal/Magazine/Newsletter
System:
The Portal to Texas History
The extraction of bitumen from western tar sands. Annual report, July 1990--July 1991
Contents of this report include the following: executive summary; characterization of the native bitumen from the Whiterocks oil sand deposit; influence of carboxylic acid content on bitumen viscosity; water based oil sand separation technology; extraction of bitumen from western oil sands by an energy-efficient thermal method; large- diameter fluidized bed reactor studies; rotary kiln pyrolysis of oil sand; catalytic upgrading of bitumen and bitumen derived liquids; ebullieted bed hydrotreating and hydrocracking; super critical fluid extraction; bitumen upgrading; 232 references; Appendix A--Whiterocks tar sand deposit bibliography; Appendix B--Asphalt Ridge tar sand deposit bibliography; and Appendix C--University of Utah tar sands bibliography.
Date:
April 1, 1992
Creator:
Oblad, A. G.; Bunger, J. W.; Deo, M. D.; Hanson, F. V.; Miller, J. D. & Seader, J. D.
Object Type:
Report
System:
The UNT Digital Library
Structure of the Espanola Basin, Rio Grande Rift, New Mexico, from SAGE seismic and gravity data
Seismic and gravity data, acquired by the SAGE program over the past twelve years, are used to define the geometry of the Espanola basin and the extent of pre-Tertiary sedimentary rocks. The Paleozoic and Mesozoic units have been thinned and removed during Laramide uplift in an area now obscured by the younger rift basin. The Espanola basin is generally a shallow, asymmetric transitional structure between deeper, better developed basins to the northeast and southwest. The gravity data indicate the presence of three narrow, but deep, structural lows arrayed along the Embudo/Pajarito fault system. These sub-basins seem to be younger than the faults on the basin margins. This apparent focussing of deformation in the later history of the basin may be a response to changes in regional stress or more local accommodation of the rift extension. Future work is planned to develop seismic data over one of these sub-basins, the Velarde graben, and to better define the gravity map in order to facilitate three-dimensional modeling.
Date:
April 1, 1995
Creator:
Ferguson, J. F.; Baldridge, W. S.; Braile, L. W.; Biehler, S.; Gilpin, B. & Jiracek, G. R.
Object Type:
Article
System:
The UNT Digital Library
Land application uses for dry FGD by-products, Phase 1 report
The 1990 amendments to the Clean Air Act have spurred the development of flue gas desulfurization (FGD) processes, several of which produce a dry, solid by-product material consisting of excess sorbent, reaction products containing sulfates and sulfites, and coal fly ash. FGD by-product materials are treated as solid wastes and must be landfilled. It is highly desirable to find beneficial reuses for these materials provided the environmental impacts are minimal and socially acceptable. Phase 1 results of a 4 and 1/2 year study to demonstrate large volume beneficial uses of FGD by-products are reported. The purpose of the Phase 1 portion of the project was to characterize the chemical, physical, mineralogical and engineering properties of the FGD by-product materials obtained from various FGD technologies being developed in the state of Ohio. Phase 1 also involved the collection of baseline economic data related to the beneficial reuse of these FGD materials. A total of 58 samples were collected and analyzed. The results indicated the chemical composition of the FGD by-product materials were dominated by Ca, S, Al, and Si. Many of the elements regulated by the US Environmental Protection Agency reside primarily in the fly ash. Phase 1 results revealed that …
Date:
April 1, 1993
Creator:
Bigham, J.; Dick, W.; Forster, L.; Hitzhusen, F.; McCoy, E.; Stehouwer, R. et al.
Object Type:
Report
System:
The UNT Digital Library
Solar powered hydrogen generating facility and hydrogen powered vehicle fleet. Final technical report, August 11, 1994--January 6, 1997
This final report describes activities carried out in support of a demonstration of a hydrogen powered vehicle fleet and construction of a solar powered hydrogen generation system. The hydrogen generation system was permitted for construction, constructed, and permitted for operation. It is not connected to the utility grid, either for electrolytic generation of hydrogen or for compression of the gas. Operation results from ideal and cloudy days are presented. The report also describes the achievement of licensing permits for their hydrogen powered trucks in California, safety assessments of the trucks, performance data, and information on emissions measurements which demonstrate performance better than the Ultra-Low Emission Vehicle levels.
Date:
April 1, 1997
Creator:
Provenzano, J.J.
Object Type:
Report
System:
The UNT Digital Library
La-oxides as tracers for PuO{sub 2} to simulate contaminated aerosol behavior
An analytical and experimental study was performed on the use of lanthanide oxides (La-oxides) as surrogates for plutonium oxides (PuO{sub 2}) during simulated buried waste retrieval. This study determined how well the La-oxides move compared to PuO{sub 2} in aerosolized soils during retrieval scenarios. As part of the analytical study, physical properties of La-oxides and PuO{sub 2}, such as molecular diameter, diffusivity, density, and molecular weight are compared. In addition, an experimental study was performed in which Idaho National Engineering Laboratory (INEL) soil, INEL soil with lanthanides, and INEL soil with plutonium were aerosolized and collected in filters. Comparison of particle size distribution parameters from this experimental study show similarity between INEL soil, INEL soil with lanthanides, and INEL soil with plutonium.
Date:
April 1, 1994
Creator:
Meyer, L. C.; Newton, G. J.; Cronenberg, A. W. & Loomis, G. G.
Object Type:
Report
System:
The UNT Digital Library
Design, Development and Testing of a Drillable Straddle Packer for Lost Circulation Control in Geothermal Drilling
Lost Circulation is a widespread problem encountered when drilling geothermal wells, and often represents a substantial portion of the cost of drilling a well. The U.S. Department of Energy sponsors research and development work at Sandia National Laboratories in an effort to reduce these lost circulation expenditures. Sandia has developed a down hole tool that improves the effectiveness and reduces th cost of lost circulation cement treatment while drilling geothermal wells. This tool, the Drillable Straddle Packer, is a low-cost disposable device that is used to isolate the loss zone and emplace the cement treatment directly into the region of concern. This report documents the design and development of the Drillabe Straddle Packer, the laboratory and field test results, and the design package that is available to transfer this technology to industry users.
Date:
April 1, 1999
Creator:
Gabaldon, J.; Glowka, D. A.; Gronewald, P.; Knudsen, S. D.; Raymond, D. W.; Staller, G. E. et al.
Object Type:
Report
System:
The UNT Digital Library
Color Measurements on Marble and Limestone Briquettes Exposed to Outdoor Environment in the Eastern United States
In a long-term program that began in 1984, limestone and marble briquettes have been exposed to both anthropogenic acid deposition and natural weathering at four field sites in the eastern United States.
Date:
April 1994
Creator:
Reimann, K. J.
Object Type:
Report
System:
The UNT Digital Library
An adaptive optics package designed for astronomical use with a laser guide star tuned to an absorption line of atomic sodium
We present the design and implementation of a very compact adaptive optic system that senses the return light from a sodium guide-star and controls a deformable mirror and a pointing mirror to compensate atmospheric perturbations in the wavefront. The deformable mirror has 19 electrostrictive actuators and triangular subapertures. The wavefront sensor is a Hartmann sensor with lenslets on triangular centers. The high-bandwidth steering mirror assembly incorporates an analog controller that samples the tilt with an avalanche photodiode quad cell. An {line_integral}/25 imaging leg focuses the light into a science camera that can either obtain long-exposure images or speckle data. In laboratory tests overall Strehl ratios were improved by a factor of 3 when a mylar sheet was used as an aberrator. The crossover frequency at unity gain is 30 Hz.
Date:
April 11, 1994
Creator:
Salmon, J. T.; Avicola, K. & Brase, J. M.
Object Type:
Article
System:
The UNT Digital Library
Land application uses for dry FGD by-products. Phase 1, [Annual report], December 1, 1991--November 30, 1992
The 1990 amendments to the Clean Air Act have spurred the development of flue gas desulfurization (FGD) processes, several of which produce a dry, solid by-product material consisting of excess sorbent, reaction products containing sulfates and sulfites, and coal fly ash. Presently FGD by-product materials are treated as solid wastes and must be landfilled. However, landfill sites are becoming more scarce and tipping fees are constantly increasing. It is, therefore, highly desirable to find beneficial reuses for these materials provided the environmental impacts are minimal and socially acceptable. Phase 1 results of a 4 and 1/2 year study to demonstrate large volume beneficial uses of FGD by-products are reported. The purpose of the Phase 1 portion of the project was to characterize the chemical, physical, mineralogical and engineering properties of the FGD by-product materials obtained from various FGD technologies being developed in the state of Ohio. Phase 1 also involved the collection of baseline economic data related to the beneficial reuse of these FGD materials. A total of 58 samples were collected and analyzed. In summary Phase 1 results revealed that FGD by-product materials are essentially coal fly ash materials diluted with unreacted sorbent and reaction products. High volume beneficial …
Date:
April 1, 1993
Creator:
Bigham, J.; Dick, W.; Forster, L.; Hitzhusen, F.; McCoy, E.; Stehouwer, R. et al.
Object Type:
Report
System:
The UNT Digital Library
Color measurements on marble and limestone briquettes exposed to outdoor environment in the Eastern United States. Volume I: Results of exposure 1984-1990
In a long-term program that began in 1984, limestone and marble briquettes have been exposed to both anthropogenic acid deposition and natural weathering at four field sites in the eastern United States. Similar tests began at an Ohio site in 1986. Effects of exposure on the briquettes and other materials at the sites are evaluated periodically by several federal agencies cooperating in the National Acid Precipitation Assessment Program (NAPAP). One of the primary contributions of Argonne National Laboratory to the NAPAP has been the measurement of tristimulus color change on samples exposed to the environment. Results from the first six years indicate a yellowing of the marble and a darkening of limestone on both the skyward and groundward surfaces of fresh and preexposed briquettes. The relationship between discoloration and exposure period appears to be linear. Discoloration rates as a function of a cumulative exposure time are almost constant for marble and slightly decreasing for limestone Dark spots on groundward surfaces were measured with tristimulus color equipment prior to chemical analysis to determine if a correlation exists between darkening (change in reflectance) and SO{sub 4} concentration. Taking exposure time into consideration, and assuming that the airborne concentration of dark particles, which …
Date:
April 1, 1994
Creator:
Reimann, K. J.
Object Type:
Report
System:
The UNT Digital Library
Impact of a 1,000-foot thermal mixing zone on the steam electric power industry
Thermal discharge requirements for power plants using once-through cooling systems are based on state water quality standards for temperatures that must be met outside of designated mixing zones. This study evaluates the impact of limiting the extent of thermal mixing zones. This study evaluates the impact of limiting the extent of thermal mixing zones to no more than 1,000 feet from the discharge point. Data were collected from 79 steam electric plants. Of the plants currently using once-through cooling systems, 74% could not meet current thermal standards at the edge of a 1,000-foot mixing zone. Of this total, 68% would retrofit cooling towers, and 6% would retrofit diffusers. The estimated nationwide capital cost for retrofitting plants that could not meet current thermal standards at the edge of a 1,000-foot mixing zone is $21.4 billion. Conversion of a plant from once-through cooling to cooling towers or addition of diffusers would result in a lower energy output from that plant. For the affected plants, the total estimated replacement cost would be $370 to $590 million per year. Some power companies would have to construct new generating capacity to meet the increased energy demand. The estimated nationwide cost of this additional capacity would …
Date:
April 1, 1994
Creator:
Veil, J. A.
Object Type:
Report
System:
The UNT Digital Library
Evaluation and silicon nitride internal combustion engine components. Final report, Phase I
The feasibility of silicon nitride (Si{sub 3}N{sub 4}) use in internal combustion engines was studied by testing three different components for wear resistance and lower reciprocating mass. The information obtained from these preliminary spin rig and engine tests indicates several design changes are necessary to survive high-stress engine applications. The three silicon nitride components tested were valve spring retainers, tappet rollers, and fuel pump push rod ends. Garrett Ceramic Components` gas-pressure sinterable Si{sub 3}N{sub 4} (GS-44) was used to fabricate the above components. Components were final machined from densified blanks that had been green formed by isostatic pressing of GS-44 granules. Spin rig testing of the valve spring retainers indicated that these Si{sub 3}N{sub 4} components could survive at high RPM levels (9,500) when teamed with silicon nitride valves and lower spring tension than standard titanium components. Silicon nitride tappet rollers showed no wear on roller O.D. or I.D. surfaces, steel axles and lifters; however, due to the uncrowned design of these particular rollers the cam lobes indicated wear after spin rig testing. Fuel pump push rod ends were successful at reducing wear on the cam lobe and rod end when tested on spin rigs and in real-world race applications.
Date:
April 1, 1992
Creator:
Voldrich, W.
Object Type:
Report
System:
The UNT Digital Library
Comparison of neutron probe and time domain reflectometry techniques of soil moisture analysis
The Environmental Science Group of Los Alamos National Laboratory collected soil water content data using Time Domain Reflectometry (TDR) and neutron probe in order to correlate the results from the two techniques in a study performed at Los Alamos, NM. Two well-characterized field plots (3m {times} 10m) were instrumented with TDR waveguides and neutron probe access tubes at four locations. At each location, TDR rod pairs were placed horizontally at 5-,15-,30-,45- and 60-cm depths and vertical sets of rod pairs with lengths of 15-,30-,45- and 60-cm were installed. Neutron probe measurements were taken at 15-,30-,45- and 60-cm depths. Because the neutron probe measures a spherical volume, soil water content values were compared with horizontal TDR readings averaged over the same zone. Additionally, vertical TDR readings were compared to neutron probe readings averaged over the depths corresponding to each TDR length. Measurements for each technique were taken weekly since Fall of 1992. A time series comparison of the results is presented.
Date:
April 1, 1994
Creator:
Schofield, T. G.; Langhorst, G. J.; Trujillo, G.; Bostick, K. V. & Hansen, W. R.
Object Type:
Article
System:
The UNT Digital Library
Ranking of Texas reservoirs for application of carbon dioxide miscible displacement
Of the 431 reservoirs screened, 211 projected revenue that exceeded cost, ie, were profitable. Only the top 154 reservoirs, however, showed a profit greater than 30%. The top 10 reservoirs predicted a profit of at least 80%. Six of the top ten were Gulf Coast sandstones. The reservoirs are representative of the most productive discoveries in Texas; they account for about 72% of the recorded 52 billion barrels oil production in the State. Preliminary evaluation in this study implied that potential production from CO{sub 2}-EOR could be as much as 4 billion barrels. In order to enhance the chances of achieving this, DOE should consider a targeted outreach program to the specific independent operators controlling the leases. Development of ownership/technical potential maps and an outreach program should be initiated to aid this identification.
Date:
April 1, 1996
Creator:
Ham, J
Object Type:
Report
System:
The UNT Digital Library
Inhalation developmental toxicology studies: Developmental toxicity of chloroprene vapors in New Zealand white rabbits. Final report
Chloroprene, 2-chloro-1,3-butadiene, is a colorless liquid with a pungent ethereal odor that is primarily used as an intermediate in the manufacture of neoprene rubber, and has been used as such since about 1930. This study addressed the potential for chloroprene to cause developmental toxicity in New Zealand white rabbits following gestational exposure to 0, 10, 40, or 175 ppm chloroprene vapors, 6h/dy, 7dy/wk. Each treatment group consisted of 15 artificially inseminated females exposed on 6 through 28 days of gestation (dg). Body weights were obtained throughout the study period, and uterine and fetal body weights were obtained at sacrifice on 29 dg. Implants were enumerated and their status recorded and live fetuses were examined for gross, visceral, skeletal, and soft-tissue craniofacial defects. There were no overt signs of maternal toxicity and the change in maternal body weight over the course of the study was not affected. Exposure of pregnant rabbits to chloroprene vapors on 6-28 dg had no effect on the number of implantation, the mean percent of live pups per litter, or on the incidence of resorptions per litter. The incidence of fetal malformations was not increased by exposure to chloroprene. Results of this study indicate that gestational exposure …
Date:
April 1, 1994
Creator:
Mast, T. J.; Evanoff, J. J.; Westerberg, R. B.; Rommereim, R. L. & Weigel, R. J.
Object Type:
Report
System:
The UNT Digital Library
Simulation of landscape disturbances and the effect of climatic change. Final report, July 15, 1990--January 14, 1993
Altering the natural disturbance regime of a landscape produces changes in the structure of that landscape as the landscape adjusts to the new disturbance regime. A computer simulation model was designed to enable analyses of the longterm changes to be expected in landscapes as their disturbance regime changes. The model, DISPATCH, is the first dynamic spatial simulation model built around a geographical information system (GIS). The model also includes a new set of programs, the r.le programs, that is the first set of programs designed for calculating landscape structure measures within a GIS. The DISPATCH model was used, to analyze the effects of human alterations of disturbance regimes and global change on landscape structure. Landscapes do not adjust quickly to these alterations based on available data. Landscapes subjected to warming or to longterm fire suppression experience a decline in patch richness, Shannon diversity, the amount of edge and contrast, but an increase in distance between patches, angular second moment (texture measure) and patch size. In contrast, landscapes subjected to cooling, the short-term effects of fire suppression, fragmentation, or traditional prescribed burning tend to respond with increasing richness, Shannon diversity, edge, and contrast, but declining distance, angular second moment, and size. …
Date:
April 1, 1993
Creator:
Baker, W. L.
Object Type:
Report
System:
The UNT Digital Library