(Experimental development, testing and research work in support of the inertial confinement fusion program) (open access)

(Experimental development, testing and research work in support of the inertial confinement fusion program)

This report discusses: Cryogenic technology; polymer shell fabrication; glass shell fabrication and characterization; coating technology; development of characterization techniques; laser technology; and plasma research and instrumentation.
Date: February 28, 1990
Creator: Drake, D.J.; Luckhardt, R.; Moyer, S.; Armentrout, C.J.; Downs, R.L. & Moncur, K. (eds.)
Object Type: Report
System: The UNT Digital Library
High resolution microstructural and microchemical analysis of zirconia eutectic interfaces (open access)

High resolution microstructural and microchemical analysis of zirconia eutectic interfaces

The goal of the research performed here is to study and understand the nature of fine scale microchemical variation, on the order of the lattice periodicity, in ceramic oxides. To that end, during the past year, emphasis was placed on the selection of appropriate materials systems and their fabrication into samples suitable for study using advanced high resolution analytical electron microscopy (work to be performed in the coming year). The work concentrated on two materials systems.
Date: January 28, 1992
Creator: Notis, Michael R.
Object Type: Report
System: The UNT Digital Library
Modeling the absorption of intense, short laser pulses in steep density gradients (open access)

Modeling the absorption of intense, short laser pulses in steep density gradients

A subroutine which calculates the absorption of short pulse electromagnetic radiation in a material has been installed into the laser fusion modeling program called LASNEX. Calculational results show the necessity for NLTE physics to account for ionization, the development of non-exponential density profiles for the expanding plasma and movement of the critical point toward the surface which results in Doppler shifts of the reflected light. Comparison of calculations of local scale lengths with experiments shows not only good agreement but the correct scaling with intensity. 8 refs., 5 figs.
Date: January 28, 1991
Creator: Alley, W.E.
Object Type: Article
System: The UNT Digital Library
Construction of a human genome library composed of multimegabase acentric chromosome fragments (open access)

Construction of a human genome library composed of multimegabase acentric chromosome fragments

None
Date: February 28, 1992
Creator: Lane, M.J.
Object Type: Report
System: The UNT Digital Library
Ultrasonic cleaning of depleted uranium material as an alternative to nitric acid cleaning (open access)

Ultrasonic cleaning of depleted uranium material as an alternative to nitric acid cleaning

Nitric acid is used to clean depleted uranium in the form of cast billets, and cast and wrought parts in the processing cycle and is the largest contributor of waste to the West End Treatment Facility (WETF). An estimated 27,000 gallons of liquid and 75 to 95% of all uranium received was sent to the WETF for processing from this facility in our baseline year. Because wrought parts account for the largest throughput at the nitric acid facility, an alternative cleaning method for these parts was examined first. Test results on the first part type from the wrought family showed ultrasonic cleaning to be an effective cleaning method. Since the geometry for this part presented the most difficulty in terms of ultrasonic cleaning, the entire wrought family is expected to be moved from the nitric acid facility to the ultrasonic cleaning facility. As a result, there will be an 83% reduction part throughput at the nitric acid facility which corresponds to a significant decrease in wastes sent to the WETF and a reduction in the generation and associated costs of waste overall. This change also eliminated two building moves involving two RAD areas resulting in a part movement reduction of …
Date: May 28, 1991
Creator: Frye, L.E. & Senviel, C.B.
Object Type: Report
System: The UNT Digital Library
Molecular mechanisms in radiation damage to DNA (open access)

Molecular mechanisms in radiation damage to DNA

The objectives of this work are to elucidate the molecular mechanisms that are responsible for radiation-induced DNA damage. The overall goal is to understand the relationship between the chemical and structural changes produced by ionizing radiation in DNA and the resulting impairment of biological function expressed as carcinogenesis or cell death. The studies are based on theoretical explorations of possible mechanisms that link initial radiation damage in the form of base and sugar damage to conformational changes in DNA. These mechanistic explorations should lead to the formulation of testable hypothesis regarding the processes of impairment of regulation of gene expression, alternation in DNA repair, and damage to DNA structure involved in cell death or cancer.
Date: October 28, 1991
Creator: Osman, R.
Object Type: Report
System: The UNT Digital Library
A novel process for methanol synthesis (open access)

A novel process for methanol synthesis

A bench-scale reactor is being used to conduct studies of the conversion of synthesis gas to methanol by a novel process. In previous reports, we provided evidence for a two step reaction in series: the carbonylation of methanol to methyl formate taking place in a non-equilibrium region in the vicinity of the copper chromite surface, and the hydrogenolysis of methyl formate to methanol taking place on the surface of the copper chromite. The synergism between the two catalysts enhances the rate of methanol formation. In this quarter, we tested several copper chromites (with different surface areas and stabilizing agents) on the rate of methanol synthesis. It seems likely that pore diffusion limitations control the hydrogenolysis reaction since the rate of methanol formation is proportional to the square root of the copper chromite surface area. Elemental analyses using Inductively Coupled Plasma analysis and pore size distribution analysis of copper chromite were carried out.
Date: January 28, 1992
Creator: Tierney, J.W. & Wender, I.
Object Type: Report
System: The UNT Digital Library
(Efficient identification and analysis of low and medium frequency repeats) (open access)

(Efficient identification and analysis of low and medium frequency repeats)

The effective starting date of this grant was May 15. In the first three months of this project we focused primarily on organizational and technical aspects of our research which included: organization of the database of repeats in primates; preparation of software for rapid and sensitive search of novel repetitive elements in GenBank; purchase and installation of the Sun workstation; and research on the mammal-specific MAR1 family of repetitive elements (to be communicated in October).
Date: August 28, 1991
Creator: Jurka, J.
Object Type: Report
System: The UNT Digital Library
Schlieren observations of density channels in MPPE (open access)

Schlieren observations of density channels in MPPE

Schlieren imaging techniques were used to study the density depressions created by the ATA electron beam 37 cm after the entrance foil. Typical channel depressions were 5--10% of ambient density per pulse. Under IFR guiding channel depths as deep as 30% were seen on single pulse operation. Pulse 5 of the 5 pulse burst has passed through a channel reduced to 30% of ambient density. To lowest order, one would expect channel density depressions to scale as ({Delta}n/n) {proportional to} ({number sign} of pulses * I{sub beam}/channel area). Channel depth observations scaled roughly with beam current, {number sign} of pulses, and inversely with channel area. Pressure scaling was anomalous in that {Delta}n appeared to be less sensitive to pressure than the linear dependence expected. This would require that the energy deposition (stopping power) is independent of pressure and is a surprising result which can only be explained with collective effects. Scaling of channel expansion rates with pressure suggest classical diffusion (D {proportional to} 1/n) for times up to 200 mS. During these early times, the diffusion constant was, however, 3--5 times larger than the classical value. At later times, large scale turbulence was observed and the effective diffusion constant increased …
Date: September 28, 1990
Creator: Guethlein, G. (Lawrence Livermore National Lab., CA (USA)) & Pechacek, B. (Naval Research Lab., Washington, DC (USA))
Object Type: Article
System: The UNT Digital Library
Oxidation of Coal and Coal Pyrite Mechanisms and Influence on Surface Characteristics (open access)

Oxidation of Coal and Coal Pyrite Mechanisms and Influence on Surface Characteristics

The objective of this research is to develop a mechanistic understanding of the oxidation of coal and coal pyrite, and to correlate the intrinsic physical and chemical properties of these minerals, along with changes resulting from oxidation, with those surface properties that influence the behavior in physical coal cleaning processes. The results will provide fundamental insight into oxidation, in terms of the bulk and surface chemistry, the microstructure, and the semiconductor properties of the pyrite. During the fifth quarter, wet chemical and dry oxidation tests were done on Upper Freeport coal from the Troutville {number sign}2 Mine, Clearfield County, Pennsylvania.
Date: January 28, 1992
Creator: Doyle, F. M.
Object Type: Report
System: The UNT Digital Library
Contract administration involving the remedial investigation and feasibility study at the Feed Materials Production Center (open access)

Contract administration involving the remedial investigation and feasibility study at the Feed Materials Production Center

Advanced Sciences, Incorporated (ASI), has been performing a Remedial Investigation and Feasibility Study (RI/FS) at the Feed Materials Production Center (Fernald Facility) at Fernald, Ohio, under an 8 (a) contract with the US Small Business Administration (SBA). The Fernald Facility is a Government-owned facility operated by Westinghouse Materials Company of Ohio (WMCO) under a management and operating contract. The objective of this audit was to evaluate the award and administration of the ASI contract.
Date: August 28, 1991
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Cedar Project---Original goals and progress to date (open access)

Cedar Project---Original goals and progress to date

This work encompasses a broad attack on high speed parallel processing. Hardware, software, applications development, and performance evaluation and visualization as well as research topics are proposed. Our goal is to develop practical parallel processing for the 1990's.
Date: November 28, 1990
Creator: Cybenko, G.; Kuck, D.; Padua, D. & Sameh, A.
Object Type: Report
System: The UNT Digital Library
Syntheses and structural characterization of zirconium-tin and zirconium-lead binary and ternary systems (open access)

Syntheses and structural characterization of zirconium-tin and zirconium-lead binary and ternary systems

The binary zirconium-tin system was reinvestigated. The A15 phase appears to be a line phase with a Zr{sub 4}Sn composition. The Zr{sub 5}Sn{sub 3} (Mn{sub 5}Si{sub 3}-type) and Zr{sub 5}Sn{sub 4} (Ti{sub 5}Ga{sub 4}-type) compounds are line phases below 1000{degree}C, the latter being a self-interstitial phase of the former. ZrSn{sub 2} is the tin-richest phase. There is an one-phase region between these phases with partial self-interstitials at high temperatures. The zirconium-lead system behaves similarly: there are an A15 phase with a Zr{sub {approximately}5.8}Pb composition, Zr{sub 5}Pb{sub 3} (Mn{sub 5}Si{sub 3}-type) and Zr{sub 5}Pb{sub 4} (Ti{sub 5}Ga{sub 4-type}) compounds, and a high temperature solid solution between Zr{sub 5}Pb{sub >3.5} and Zr{sub 5}Pb{sub 4} from below 1000{degree}C; however, the ZrSn{sub 2} analogue is not formed. The Mn{sub 5}Si{sub 3}-type phases in these systems can accommodate third elements interstitially to form stoichiometric compounds Zr{sub 5}Sn{sub 3}Z (Z = B, C, N, O, Al, Si, P, S, Cu, Zn, Ga, Ge, and As and Se) and Zr{sub 5}Pb{sub 3}Z (Z = Al, Si, P, S, Fe, Co, Ni, Cu, Zn, Ga, Ge, As, Se, Ag, Cd, In, Sn, Sb and Te) as well as their self-interstitial derivatives. The systems Zr-Sn-T, T = Fe, Co …
Date: January 28, 1991
Creator: Kwon, Y.U.
Object Type: Report
System: The UNT Digital Library
Advective diffusive/dispersive transport in geochemical processes (open access)

Advective diffusive/dispersive transport in geochemical processes

Comprehensive understanding of chemical transport in response to fluid flow and diffusion in geologic processes requires thermodynamic and transport properties of a wide variety of aqueous species at the temperature and pressure of interest, as well as mass transfer computer codes that provide simultaneously for fluid flow, diffusion, dispersion, homogeneous chemical reactions, and mineral solubilities. As a result of research carried out with support from DOE in prior years of this grant, considerable progress has been made in developing computer codes to calculate advective-dispersive-diffusional transport at both high and low pressures and temperatures. These codes have become highly sophisticated, but their application to geochemical processes is limited by the availability of thermodynamic and transport data for the major solute species in the aqueous phase. Over the past three years, research has been directed primarily toward characterizing the thermodynamic behavior of concentrated supercritical aqueous electrolyte solutions and predicting the diffusion coefficients of organic species in oil field brines. Related research has been concerned with characterizing the growth rate of hydrothermal alteration zones and assessing the relative importance of aqueous diffusion and heterogeneous reactions at mineral surfaces in geochemical processes. 103 refs., 12 figs.
Date: May 28, 1991
Creator: Helgeson, H. C.
Object Type: Report
System: The UNT Digital Library
Alternative filtration testing program: Pre-evaluation of test results (open access)

Alternative filtration testing program: Pre-evaluation of test results

Based on results of testing eight solids removal technologies and one pretreatment option, it is recommended that a centrifugal ultrafilter and polymeric ultrafilter undergo further testing as possible alternatives to the Norton Ceramic filters. Deep bed filtration should be considered as a third alternative, if a backwashable cartridge filter is shown to be inefficient in separate testing.
Date: September 28, 1990
Creator: Georgeton, G.K. & Poirier, M.R.
Object Type: Report
System: The UNT Digital Library
Catalytic studies on a novel synthesis of methanol (open access)

Catalytic studies on a novel synthesis of methanol

Catalytic studies on a new method for methanol synthesis from CO and H{sub 2} in a slurry reactor are described. This reaction proceeds through the carbonylation of methanol to methyl formate in the liquid phase followed by hydrogenolysis of methyl formate to two molecules of methanol; the net result is the reaction of CO with H{sub 2} to give methanol. Moderate temperatures and pressures (100--160{degrees}C, 50--65 atm) are used. Reaction rates using mixed catalysts comprised of an alkali methoxide and Cu-chromite are presented. It seems likely that Cu-chromite maintains the activity of the alkali methoxide catalyst. A mixed catalyst comprised of potassium methoxide and Cu-chromite was found to be the most active under the reaction conditions used. Evidence is provided for an interaction between the alkali methoxide and Cu-chromite. 27 refs., 6 figs., 2 tabs.
Date: June 28, 1991
Creator: Palekar, V.M.; Tierney, J.W. & Wender, I.
Object Type: Article
System: The UNT Digital Library
Engineering development of advanced coal-fired low-emission boiler system (open access)

Engineering development of advanced coal-fired low-emission boiler system

The Pittsburgh Energy Technology Center of the US Department of Energy (DOE) has contracted with Combustion Engineering, Inc. (ABB CE) to perform work on the Engineering Development of Advanced Coal-Fired Low-Emission Boiler Systems'' Project and has authorized ABB CE to complete Phase I on a cost-reimbursable basis. The overall objective of the Project is the expedited commercialization of advanced coal-fired low-emission boiler systems. The specified primary objectives are: (1) NOx emissions not greater than one-third NSPS. (2) SOx emissions not greater than one-third NSPS. (3) Particulate emissions not greater than one-half NSPS. The specific secondary objectives are: (1) Improved ash disposability and reduced waste generation. (2) Reduced air toxics emissions. (3) Increased generating efficiency. The final deliverables are a design data base that will allow future coal-fired power plants to meet the stated objectives and a preliminary design of a commercial generation unit.
Date: May 28, 1993
Creator: unknown
Object Type: Report
System: The UNT Digital Library
The cascade ICF reactor with an x-ray and debris shield and a heavy-ion driver (open access)

The cascade ICF reactor with an x-ray and debris shield and a heavy-ion driver

The use of a 1-kg solid-lithium x-ray and debris shield around each fusion fuel pellet prevents vaporization of, and destructive shock waves in, the Cascade blanket granules thereby increasing their lifetime. The shield vaporizes as it absorbs energy and the vapor flows into the blanket several centimeters. The shield also increases tritium breeding and enhances vacuum pumping of high Z materials that are vaporized in the fuel pellet. Using heavy ion beams allows illumination of the fuel pellets with the restricted geometry present in Cascade. We used a 5 MJ driver with 18 beams (one 3 {times} 3 array from each end).
Date: September 28, 1990
Creator: Pitts, John H. & Tabak, Max
Object Type: Article
System: The UNT Digital Library
Preliminary remedial action objectives for the Tank 16 groundwater operable unit (open access)

Preliminary remedial action objectives for the Tank 16 groundwater operable unit

Tank 16 is a High Level Radioactive Waste tank in the H-Area Tank Farm on the Savannah River Site that was placed into service in May 1959. A leak was detected in one of the construction weld joints while the tank was being filled. Before jet evacuation of the tank waste was completed, the leak overflowed the annulus pan and an estimated 16 to 700 gallons of waste escaped to the environment (soil and groundwater) over a six hour period contaminating approximately 1,600--70,000 cubic feet of soil with up to 5000 curies of activity (principally Cs[sup 137]). The Tank 16 bottom is constructed below the groundwater table which resulted in almost immediate contamination of that medium. Low groundwater flow rates, the ion exchange property of adjacent soils, and the distance to the nearest surface water bodies (1,500 to 8,000 feet) indicates that surface water and sediment outcrop of contaminates may be expected between 44 and 530 years (Poe et al., 1974). Remedial action objectives consist of medium-specific and operable unit specific goals for protecting human health and the environment. These objectives are specific and do not limit the range of alternatives that may be developed.A range of remedial technologies, which …
Date: October 28, 1992
Creator: Miles, W.C. Jr.
Object Type: Report
System: The UNT Digital Library
The role of catalyst precursor anions in coal gasification (open access)

The role of catalyst precursor anions in coal gasification

The aims of the proposed project are to enrich our understanding of the roles of various aqueous soluble catalyst precursor anions on the surface electrical properties of coal and to ascertain the influence of the surface charge on the adsorption, dispersion, and activities of calcium and potassium. These goals will be achieved by impregnating a North Dakota lignite (PSOC 1482) and its demineralized derivative with calcium or potassium catalyst precursors containing acetate (CH{sub 3}COO{sup {minus}}), chloride (Cl{sup {minus}}), nitrate (NO{sub 3}{sup {minus}}), sulfate (SO{sub 4}{sup 2{minus}}), and carbonate (CO{sub 3}{sup 2{minus}}) anions. Catalyst loading will be conducted under well-controlled conditions of solution pH and ionic strength. In the last quarter, the surface charge properties of the coal was determined as a function of acetate (CH{sub 3}COO{sup {minus}}), chloride (Cl{sup {minus}}), nitrate (NO{sup 3}{sup {minus}}), carbonate (CO{sub 3}{sup 2{minus}}) or sulfate (SO{sub 4}{sup 2{minus}})concentration using the respective potassium salts of these anions. In general, low anion concentrations (10{sup {minus}3} or 10{sup {minus}2} mol/L) had little effect on the zeta potentials of the coals. However, the surface charge densities of the coal become less negative at 10-1 mol/L of the nitrate, carbonate or sulfate anions. These trends suggest that the surface charge …
Date: August 28, 1992
Creator: Abotsi, G.M.K.
Object Type: Report
System: The UNT Digital Library
Intergranular stress corrosion cracking: A rationalization of apparent differences among stress corrosion cracking tendencies for sensitized regions in the process water piping and in the tanks of SRS reactors (open access)

Intergranular stress corrosion cracking: A rationalization of apparent differences among stress corrosion cracking tendencies for sensitized regions in the process water piping and in the tanks of SRS reactors

The frequency of stress corrosion cracking in the near weld regions of the SRS reactor tank walls is apparently lower than the cracking frequency near the pipe-to-pipe welds in the primary cooling water system. The difference in cracking tendency can be attributed to differences in the welding processes, fabrication schedules, near weld residual stresses, exposure conditions and other system variables. This memorandum discusses the technical issues that may account the differences in cracking tendencies based on a review of the fabrication and operating histories of the reactor systems and the accepted understanding of factors that control stress corrosion cracking in austenitic stainless steels.
Date: September 28, 1990
Creator: Louthan, M.R.
Object Type: Report
System: The UNT Digital Library
Development of biological coal gasification (MicGAS Process) (open access)

Development of biological coal gasification (MicGAS Process)

This report describes progress on three fronts of the project. First in studies to elucidate optimal growing conditions for the consortia of coal degraders employed indicates that best growth occurs with 0. 2% w/v Shefton T. Secondly in comparing the biodegradative properties of the coal degraders, isolates identified as Mic-1 and Mic-4 were the best performers. And lastly bioreactors studies in batch mode are related.
Date: July 28, 1992
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Corrosion tests of DWPF recycle solution (open access)

Corrosion tests of DWPF recycle solution

Coupon immersion tests were performed on ASTM A537, Class 1 carbon steel in simulated Defense Waste Processing Facility recycle solutions at 93 [plus minus] 2[degree]C, in an effort to reproduce the results of earlier tests in which hard, shock-sensitive deposits were found. There was no evidence of pitting corrosion on the coupons exposed to solutions containing 0.5 M hydroxide and 2000 ppm (0.043 M) nitrite. Liquid mercury and small solid deposits were found on the specimens' immersed surfaces. However, the deposits were soft and not shock-sensitive. The absence of shock-sensitive deposits may have been due to a lower mercuric ion concentration in the test solutions or to different post-immersion handling. Coupons of 304L stainless steel and alloy C276 were also immersed in the simulated recycle solution. These coupons were not subject to localized corrosion, nor were shock-sensitive deposits found. Additional immersion tests on A537 coupons will be started in July 1992.
Date: July 28, 1992
Creator: Zapp, P.E.
Object Type: Report
System: The UNT Digital Library
Commercial nuclear power 1990 (open access)

Commercial nuclear power 1990

This report presents the status at the end of 1989 and the outlook for commercial nuclear capacity and generation for all countries in the world with free market economies (FME). The report provides documentation of the US nuclear capacity and generation projections through 2030. The long-term projections of US nuclear capacity and generation are provided to the US Department of Energy's (DOE) Office of Civilian Radioactive Waste Management (OCRWM) for use in estimating nuclear waste fund revenues and to aid in planning the disposal of nuclear waste. These projections also support the Energy Information Administration's annual report, Domestic Uranium Mining and Milling Industry: Viability Assessment, and are provided to the Organization for Economic Cooperation and Development. The foreign nuclear capacity projections are used by the DOE uranium enrichment program in assessing potential markets for future enrichment contracts. The two major sections of this report discuss US and foreign commercial nuclear power. The US section (Chapters 2 and 3) deals with (1) the status of nuclear power as of the end of 1989; (2) projections of nuclear capacity and generation at 5-year intervals from 1990 through 2030; and (3) a discussion of institutional and technical issues that affect nuclear power. The …
Date: September 28, 1990
Creator: unknown
Object Type: Report
System: The UNT Digital Library