Surfactant studies for bench-scale operation (open access)

Surfactant studies for bench-scale operation

A phase II study has been initiated to investigate surfactant-assisted coal liquefaction, with the objective of quantifying the enhancement in liquid yields and product quality. This publication covers the first quarter of work. The major accomplishments were: (1) the refurbishment of the high-pressure, high-temperature reactor autoclave, (2) the completion of four coal liquefaction runs with Pittsburgh [number sign]8 coal, two each with and without sodium lignosulfonate surfactant, and (3) the development of an analysis scheme for the product liquid filtrate and filter cake. Initial results at low reactor temperatures show that the addition of the surfactant produces an improvement in conversion yields and an increase in lighter boiling point fractions for the filtrate.
Date: December 30, 1992
Creator: Hickey, G.S. & Sharma, P.K.
Object Type: Report
System: The UNT Digital Library
Surfactant studies for bench-scale operation. First quarterly technical progress report, July 1, 1992--September 30, 1992 (open access)

Surfactant studies for bench-scale operation. First quarterly technical progress report, July 1, 1992--September 30, 1992

A phase II study has been initiated to investigate surfactant-assisted coal liquefaction, with the objective of quantifying the enhancement in liquid yields and product quality. This publication covers the first quarter of work. The major accomplishments were: (1) the refurbishment of the high-pressure, high-temperature reactor autoclave, (2) the completion of four coal liquefaction runs with Pittsburgh {number_sign}8 coal, two each with and without sodium lignosulfonate surfactant, and (3) the development of an analysis scheme for the product liquid filtrate and filter cake. Initial results at low reactor temperatures show that the addition of the surfactant produces an improvement in conversion yields and an increase in lighter boiling point fractions for the filtrate.
Date: December 30, 1992
Creator: Hickey, G. S. & Sharma, P. K.
Object Type: Report
System: The UNT Digital Library
Direct Methane Conversion to Methanol (open access)

Direct Methane Conversion to Methanol

Objective is to demonstrate the effectiveness of a catalytic membrane reactor (ceramic membrane combined with catalyst) to selectively produce methanol by partial oxidation of methane. None of the membranes tested in a high pressure system could selectively remove methanol, until a cooling tube was inserted inside the membrane reactor to quench the product stream; this effectively increased methanol selectivity 2[times] during methane oxidation. For both conditions, combined selectivity for methanol and CO is constant, 85%. The remaining product is CO[sub 2]. The membranes were broken when removed from the system; this was remedied when a cooling tube with a smaller diameter was used.
Date: December 3, 1992
Creator: Falconer, J. L. & Noble, R. D.
Object Type: Report
System: The UNT Digital Library
Direct Methane Conversion to Methanol. Quarterly Project Status Report, July 1, 1992--September 30, 1992 (open access)

Direct Methane Conversion to Methanol. Quarterly Project Status Report, July 1, 1992--September 30, 1992

Objective is to demonstrate the effectiveness of a catalytic membrane reactor (ceramic membrane combined with catalyst) to selectively produce methanol by partial oxidation of methane. None of the membranes tested in a high pressure system could selectively remove methanol, until a cooling tube was inserted inside the membrane reactor to quench the product stream; this effectively increased methanol selectivity 2{times} during methane oxidation. For both conditions, combined selectivity for methanol and CO is constant, 85%. The remaining product is CO{sub 2}. The membranes were broken when removed from the system; this was remedied when a cooling tube with a smaller diameter was used.
Date: December 3, 1992
Creator: Falconer, J. L. & Noble, R. D.
Object Type: Report
System: The UNT Digital Library
1991 Environmental Monitoring Report Sandia National Laboratories, Albuquerque, New Mexico (open access)

1991 Environmental Monitoring Report Sandia National Laboratories, Albuquerque, New Mexico

This 1991 report contains monitoring data from routine radiological and nonradiological environmental surveillance activities. Summaries of significant environmental compliance programs in progress such as National Environmental Policy Act (NEPA) documentation, environmental permits, environmental restoration (ER), and various waste management programs for Sandia National Laboratories in Albuquerque (SNL, Albuquerque) are included. The maximum offsite dose impact was calculated to be 1.3 {times} 10{sup {minus}3} mrem. The total population within a 50-mile radius of SNL, Albuquerque, received a collective dose of 0.53 person-rem during 1991 from SNL, Albuquerque, operations. As in the previous year, the 1991 operations at SNL, Albuquerque, had no discernible impact on the general public or on the environment.
Date: November 1992
Creator: Culp, T.; Cox, W.; Hwang, S.; Jones, A.; Longley, S.; Parsons, A. et al.
Object Type: Report
System: The UNT Digital Library
Role of polycrystallinity in CdTe and CuInSe[sub 2] photovoltaic cells (open access)

Role of polycrystallinity in CdTe and CuInSe[sub 2] photovoltaic cells

The limiting role of polycrystallinity in thin-film solar calls has been reduced somewhat during the past year, and efficiencies of both CdTe and CuInSe[sub 2] cells are approaching 15%. Quantitative separation of loss mechanisms shows that individual losses, with the exception of forward recombination current, can be made comparable to their single crystal counterparts. One general manifestation of the extraneous trapping states in that the voltage of all polycrystalline thin-film cells drifts upward by 10--50 mV following the onset of illumination.
Date: November 1, 1992
Creator: Sites, J.R. (Colorado State Univ., Fort Collins, CO (United States))
Object Type: Report
System: The UNT Digital Library
Role of polycrystallinity in CdTe and CuInSe{sub 2} photovoltaic cells. Annual subcontract report, 1 April 1991--31 March 1992 (open access)

Role of polycrystallinity in CdTe and CuInSe{sub 2} photovoltaic cells. Annual subcontract report, 1 April 1991--31 March 1992

The limiting role of polycrystallinity in thin-film solar calls has been reduced somewhat during the past year, and efficiencies of both CdTe and CuInSe{sub 2} cells are approaching 15%. Quantitative separation of loss mechanisms shows that individual losses, with the exception of forward recombination current, can be made comparable to their single crystal counterparts. One general manifestation of the extraneous trapping states in that the voltage of all polycrystalline thin-film cells drifts upward by 10--50 mV following the onset of illumination.
Date: November 1, 1992
Creator: Sites, J. R.
Object Type: Report
System: The UNT Digital Library
Electrical characterization of electrophoretically coated aluminum samples for photovoltaic concentrator application (open access)

Electrical characterization of electrophoretically coated aluminum samples for photovoltaic concentrator application

The practicality of using a thin-film styrene/acrylate copolymer electrophoretic coating to isolate concentrator cells electrically from their surroundings in a photovoltaic concentrator module is assessed. Only the electrical isolation problem was investigated. The approach was to subject various types of EP-coated aluminum specimens to electrical stress testing and to aging tests while monitoring coating electrical resistivity properties. It was determined that, in general, longer processing times--i.e., thicker electrophoretic layers--resulted in better voltage-withstand properties. In particular, a two-minute processing time seemed sufficient to provide the electrical isolation required in photovoltaic concentrator application applications. Even though electrophoretic coatings did not seem to fill voids in porous-anodized aluminum substrates, breakdown voltages generally exceeded hi-pot pass-fail voltage levels with a comfortable margin. 6 refs, 11 figs, 5 tabs.
Date: October 1, 1992
Creator: Sugimura, R. S.; Mon, G. R. & Ross, R. G. Jr.
Object Type: Report
System: The UNT Digital Library
Electron cyclotron resonance deposition of amorphous silicon alloy films and devices (open access)

Electron cyclotron resonance deposition of amorphous silicon alloy films and devices

This report describes work to develop a state-of-the-art electron cyclotron resonance (ECR) plasma-enhanced chemical vapor deposition (PECVD) system. The objective was to understand the deposition processes of amorphous silicon (a-Si:H) and related alloys, with a best-effort improvement of optoelectronic material properties and best-effort stabilization of solar cell performance. ECR growth parameters were systematically and extensively investigated; materials characterization included constant photocurrent measurement (CPM), junction capacitance, drive-level capacitance profiling (DLCP), optical transmission, light and dark photoconductivity, and small-angle X-ray scattering (SAXS). Conventional ECR-deposited a-Si:H was compared to a new form, a-Si:(Xe, H), in which xenon gas was added to the ECR plasma. a-Si:(Xe,H) possessed low, stable dark conductivities and high photosensitivites. Light-soaking revealed photodegradation rates about 35% lower than those of comparable radio frequency (rf)-deposited material. ECR-deposited p-type a SiC:H and intrinsic a-Si:H films underwent evaluation as components of p-i-n solar cells with standard rf films for the remaining layers.
Date: October 1, 1992
Creator: Shing, Y. H. (Jet Propulsion Lab., Pasadena, CA (United States))
Object Type: Report
System: The UNT Digital Library
Electron cyclotron resonance deposition of amorphous silicon alloy films and devices. Final subcontract report, 1 April 1991--31 March 1992 (open access)

Electron cyclotron resonance deposition of amorphous silicon alloy films and devices. Final subcontract report, 1 April 1991--31 March 1992

This report describes work to develop a state-of-the-art electron cyclotron resonance (ECR) plasma-enhanced chemical vapor deposition (PECVD) system. The objective was to understand the deposition processes of amorphous silicon (a-Si:H) and related alloys, with a best-effort improvement of optoelectronic material properties and best-effort stabilization of solar cell performance. ECR growth parameters were systematically and extensively investigated; materials characterization included constant photocurrent measurement (CPM), junction capacitance, drive-level capacitance profiling (DLCP), optical transmission, light and dark photoconductivity, and small-angle X-ray scattering (SAXS). Conventional ECR-deposited a-Si:H was compared to a new form, a-Si:(Xe, H), in which xenon gas was added to the ECR plasma. a-Si:(Xe,H) possessed low, stable dark conductivities and high photosensitivites. Light-soaking revealed photodegradation rates about 35% lower than those of comparable radio frequency (rf)-deposited material. ECR-deposited p-type a SiC:H and intrinsic a-Si:H films underwent evaluation as components of p-i-n solar cells with standard rf films for the remaining layers.
Date: October 1, 1992
Creator: Shing, Y. H.
Object Type: Report
System: The UNT Digital Library
Analysis of thermally-stable electron transport factors from the hyperthermophilic archaebacterium Pyrodictium brockii (open access)

Analysis of thermally-stable electron transport factors from the hyperthermophilic archaebacterium Pyrodictium brockii

The mechanisms by which hyperthermophilic archaebacteria grow and carry out metabolic functions at elevated temperatures have yet to be determined. The objective of this work is to develop an understanding of the metabolic characteristics of, and the electron transport enzymes involved in, hydrogen/sulfur transformation by hyperthermophilic archaebacteria. Efforts focus on the autotrophic H{sub 2}-oxidizing bacterium, Pyrodictium brockii which has an optimum growth temperature of 105{degrees}C. Biochemical and genetic characterization of enzymes involved in hydrogen oxidizing electron transport pathway. These including investigating the role of the membrane lipids in protecting the hydrogenase enzyme from thermal inactivation, characterization of a quinone and a c-type cytochrome, and analysis of the topology in the membrane in the net energy generating components are reported. The long-term goal is to understand some of the factors contributing to the biochemical basis of extreme thermophily.
Date: September 1, 1992
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Analysis of thermally-stable electron transport factors from the hyperthermophilic archaebacterium Pyrodictium brockii. Progress report (open access)

Analysis of thermally-stable electron transport factors from the hyperthermophilic archaebacterium Pyrodictium brockii. Progress report

The mechanisms by which hyperthermophilic archaebacteria grow and carry out metabolic functions at elevated temperatures have yet to be determined. The objective of this work is to develop an understanding of the metabolic characteristics of, and the electron transport enzymes involved in, hydrogen/sulfur transformation by hyperthermophilic archaebacteria. Efforts focus on the autotrophic H{sub 2}-oxidizing bacterium, Pyrodictium brockii which has an optimum growth temperature of 105{degrees}C. Biochemical and genetic characterization of enzymes involved in hydrogen oxidizing electron transport pathway. These including investigating the role of the membrane lipids in protecting the hydrogenase enzyme from thermal inactivation, characterization of a quinone and a c-type cytochrome, and analysis of the topology in the membrane in the net energy generating components are reported. The long-term goal is to understand some of the factors contributing to the biochemical basis of extreme thermophily.
Date: September 1, 1992
Creator: unknown
Object Type: Report
System: The UNT Digital Library
[Development of a Human Genome Data Base]. Progress report (open access)

[Development of a Human Genome Data Base]. Progress report

This report describes managerial aspects and briefly some technical accomplishments a Human Genome Database in Baltimore.
Date: September 1, 1992
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Evaluation of Aftermarket Fuel Delivery Systems for Natural Gas and Lpg Vehicles (open access)

Evaluation of Aftermarket Fuel Delivery Systems for Natural Gas and Lpg Vehicles

This study was designed to evaluate the effectiveness of aftermarket fuel delivery systems for vehicles fueled by compressed natural gas (CNG) and liquefied petroleum gas (LPG). Most of the CNG and LPG vehicles studied were converted to the alternative fuel after purchase. There are wide variations in the quality of the conversion hardware and the installation. This leads to questions about the overall quality of the converted vehicles, in terms of emissions, safety, and performance. There is a considerable body of emissions data for converted light-duty vehicles, and a smaller amount for medium- and heavy-duty vehicles. However, very few of these data involve real world conditions, and there is growing concern about in-use emissions. This report also attempts to assess factors that could allow in-use emissions to vary from the ``best-case`` results normally reported. The study also addresses issues of fuel supply, fuel composition, performance, safety, and warranty waivers. The report is based on an extensive literature and product survey and on the author`s experience with fuel delivery systems for light-duty vehicles.
Date: September 1, 1992
Creator: Willson, B.
Object Type: Report
System: The UNT Digital Library
Evaluation of Aftermarket Fuel Delivery Systems for Natural Gas and Lpg Vehicles (open access)

Evaluation of Aftermarket Fuel Delivery Systems for Natural Gas and Lpg Vehicles

This study was designed to evaluate the effectiveness of aftermarket fuel delivery systems for vehicles fueled by compressed natural gas (CNG) and liquefied petroleum gas (LPG). Most of the CNG and LPG vehicles studied were converted to the alternative fuel after purchase. There are wide variations in the quality of the conversion hardware and the installation. This leads to questions about the overall quality of the converted vehicles, in terms of emissions, safety, and performance. There is a considerable body of emissions data for converted light-duty vehicles, and a smaller amount for medium- and heavy-duty vehicles. However, very few of these data involve real world conditions, and there is growing concern about in-use emissions. This report also attempts to assess factors that could allow in-use emissions to vary from the best-case'' results normally reported. The study also addresses issues of fuel supply, fuel composition, performance, safety, and warranty waivers. The report is based on an extensive literature and product survey and on the author's experience with fuel delivery systems for light-duty vehicles.
Date: September 1, 1992
Creator: Willson, B. (Colorado State Univ., Fort Collins, CO (United States))
Object Type: Report
System: The UNT Digital Library
Remedial Action Plan and Site Design for Stabilization of the Inactive Uranium Mill Tailings Site at Falls City, Texas: Final Report (open access)

Remedial Action Plan and Site Design for Stabilization of the Inactive Uranium Mill Tailings Site at Falls City, Texas: Final Report

The uranium processing site near Falls City, Texas, was one of 24 inactive uranium mill sites designated to be remediated by the U.S. Department of Energy (DOE) under Title I of the Uranium Mill Tailings Radiation Control Act of 1978 (UMTRCA). The UMTRCA requires that the U.S. Nuclear Regulatory Commission (NRC) concur with the DOE`s remedial action plan (RAP) and certify that the remedial action conducted at the site complies with the standards promulgated by the U.S. Environmental Protection Agency (EPA). The RAP, which includes this summary remedial action selection report (RAS), serves a two-fold purpose. First, it describes the activities proposed by the DOE to accomplish long-term stabilization and control of the residual radioactive materials at the inactive uranium processing site near Falls City, Texas. Second, this document and the remainder of the RAP, upon concurrence and execution by the DOE, the State of Texas, and the NRC, becomes Appendix B of the Cooperative Agreement between the DOE and the State of Texas.
Date: September 1, 1992
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Capillary discharge extreme ultraviolet lasers. [Colorado State Univ. , Ft. Collins] (open access)

Capillary discharge extreme ultraviolet lasers. [Colorado State Univ. , Ft. Collins]

The project objective is to explore the generation of soft X-ray laser radiation in a plasma column created by a fast capillary discharge. The proposed capillary lasing scheme offers the potential for compact, simple and efficient soft X-ray laser sources. For this purpose a compact, fast pulse generator which produces 100 kA current pulses with a risetime of 11 ns was constructed. Initial experiments were conducted in evacuated capillaries, in which the plasma is produced by ablation of the capillary walls. The soft X-ray emission from discharges in polyethylene capillary channels was studied to investigate the possibility of amplification in the 3-2 transition of C VI, at {lambda} = 18.2 nm. Time-resolved spectra in which this transition appears anomalously intense with respect to the 4--2 transition of the same ion were obtained. To date, however, this phenomenoa could not be confirmed as gain, as the intensity of the 18.2 nm line has not been observed to increase exponentially as a function of the capillary length. Encouraging results were obtained by fast pulse discharge excitation of capillaries filled with preionized gas. High temperature (Te > 150 eV), small diameter ({approximately}200 {mu}m) plasma columns were efficiently generated. Fast current pulse excitation of …
Date: August 1, 1992
Creator: Rocca, J. J.
Object Type: Report
System: The UNT Digital Library
Capillary discharge extreme ultraviolet lasers. Progress report, December 15, 1991--December 14, 1992 (open access)

Capillary discharge extreme ultraviolet lasers. Progress report, December 15, 1991--December 14, 1992

The project objective is to explore the generation of soft X-ray laser radiation in a plasma column created by a fast capillary discharge. The proposed capillary lasing scheme offers the potential for compact, simple and efficient soft X-ray laser sources. For this purpose a compact, fast pulse generator which produces 100 kA current pulses with a risetime of 11 ns was constructed. Initial experiments were conducted in evacuated capillaries, in which the plasma is produced by ablation of the capillary walls. The soft X-ray emission from discharges in polyethylene capillary channels was studied to investigate the possibility of amplification in the 3-2 transition of C VI, at {lambda} = 18.2 nm. Time-resolved spectra in which this transition appears anomalously intense with respect to the 4--2 transition of the same ion were obtained. To date, however, this phenomenoa could not be confirmed as gain, as the intensity of the 18.2 nm line has not been observed to increase exponentially as a function of the capillary length. Encouraging results were obtained by fast pulse discharge excitation of capillaries filled with preionized gas. High temperature (Te > 150 eV), small diameter ({approximately}200 {mu}m) plasma columns were efficiently generated. Fast current pulse excitation of …
Date: August 1, 1992
Creator: Rocca, J. J.
Object Type: Report
System: The UNT Digital Library
Effects of Vegetation of Radon Transport Processes in Soil: The Origins and Pathways of {Sup 222}Rn Entering Into Basement Structures. Final Report, March 15, 1987--May 15, 1993 (open access)

Effects of Vegetation of Radon Transport Processes in Soil: The Origins and Pathways of {Sup 222}Rn Entering Into Basement Structures. Final Report, March 15, 1987--May 15, 1993

The entry rate of {sup 22}Rn into a basement structure was measured continuously. These measurements demonstrated that radon entry did not vanish even when the structure was slightly pressurized. This persistent entry has been determined to be dominated by diffusion through the floor and walls and a combination of diffusion and convection through the floor-wall joint. The highest indoor radon concentrations occurred during calm periods when the pressure differentials between the inside and outside of the structure were small. The objectives of this work were to identify the origins of the radon and investigate the entry pathways. The radon could originate either in the concrete or in the soil surrounding the structure. Entry pathways into the basement were through the concrete floor and walls as well as through the floor-wall joint. The contributions of the origins and entry pathways were determined by continuously measuring the radon entry rate into the basement, using a trace gas system, and the flux density through portions of the floor and walls. Radon entry through the floor-wall joint could be controlled using a baseboard barrier system. Results indicated that, during calm conditions with wind speeds less than 1 m s{sup {minus}1}, 25 % of the …
Date: August 1, 1992
Creator: Borak, T. B.
Object Type: Report
System: The UNT Digital Library
Genes and gene expression: Localization, damage and control -- A multi-level and interdisciplinary study (open access)

Genes and gene expression: Localization, damage and control -- A multi-level and interdisciplinary study

This progress report describes gains made in three projects entitled (1) 3-Dimensional nuclear topography of genes and chromosomes in interphase nuclei, (2) Sequence specific identification and perturbation of the genomic DNA in living cells by nonionic oligonucleotide analogs (Matagen), and Resolution and isolation of specific DNA restriction fragments.(DT)
Date: August 1, 1992
Creator: Ts'o, P.O.P.
Object Type: Report
System: The UNT Digital Library
Genes and gene expression: Localization, damage and control -- A multi-level and interdisciplinary study. Progress report, February 1, 1992--January 31, 1993 (open access)

Genes and gene expression: Localization, damage and control -- A multi-level and interdisciplinary study. Progress report, February 1, 1992--January 31, 1993

This progress report describes gains made in three projects entitled (1) 3-Dimensional nuclear topography of genes and chromosomes in interphase nuclei, (2) Sequence specific identification and perturbation of the genomic DNA in living cells by nonionic oligonucleotide analogs (Matagen), and Resolution and isolation of specific DNA restriction fragments.(DT)
Date: August 1, 1992
Creator: Ts`o, P. O. P.
Object Type: Report
System: The UNT Digital Library
Activated transport in AMTEC electrodes (open access)

Activated transport in AMTEC electrodes

Transport of alkali metal atoms through porous cathodes of alkali metal thermal-to-electric converter (AMTEC) cells is responsible for significant, reducible losses in the electrical performance of these cells. Experimental evidence for activated transport of metal atoms at grain surfaces and boundaries within some AMTEC electrodes has been derived from temperature dependent studies as well as from analysis of the detailed frequency dependence of ac impedance results for other electrodes, including thin, mature molybdenum electrodes which exhibit transport dominated by free molecular flow of sodium gas at low frequencies or dc conditions. Activated surface transport will almost always exist in parallel with free molecular flow transport, and the process of alkali atom adsorption/desorption from the electrode surface will invariably be part of the transport process, and possibly a dominant part in some cases. Little can be learned about the detailed mass transport process from the ac impedance or current voltage curves of an electrode at one set of operating parameters, because the transport process includes a number of important physical parameters that are not all uniquely determined by one experiment. The temperature dependence of diffusion coefficient of the alkali metal through the electrode in several cases provides an activation energy and …
Date: July 1, 1992
Creator: Williams, R. M.; Jeffries-Nakamura, B.; Ryan, M. A.; Underwood, M. L.; O`Connor, D. & Kikkert, S.
Object Type: Article
System: The UNT Digital Library
Direct Conversion Technology (open access)

Direct Conversion Technology

The overall objective of the Direct Conversion Technology task is to develop an experimentally verified technology base for promising direct conversion systems that have potential application for energy conservation in the end-use sectors. Initially, two systems were selected for exploratory research and advanced development. These are Alkali Metal Thermal-to-Electric Converter (AMTEC) and Two-Phase Liquid Metal MD Generator (LMMHD). This report describes progress that has been made during the first six months of 1992 on research activities associated with these two systems. (GHH)
Date: July 1, 1992
Creator: Back, L.H.; Fabris, G. & Ryan, M.A.
Object Type: Report
System: The UNT Digital Library
Direct Conversion Technology. Progress report, January 1, 1992--June 30, 1992 (open access)

Direct Conversion Technology. Progress report, January 1, 1992--June 30, 1992

The overall objective of the Direct Conversion Technology task is to develop an experimentally verified technology base for promising direct conversion systems that have potential application for energy conservation in the end-use sectors. Initially, two systems were selected for exploratory research and advanced development. These are Alkali Metal Thermal-to-Electric Converter (AMTEC) and Two-Phase Liquid Metal MD Generator (LMMHD). This report describes progress that has been made during the first six months of 1992 on research activities associated with these two systems. (GHH)
Date: July 1, 1992
Creator: Back, L. H.; Fabris, G. & Ryan, M. A.
Object Type: Report
System: The UNT Digital Library