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Thermodynamics of solid and liquid group III-V alloys

Description: Solid-state electrochemical techniques are applied to the Ga-In-Sb-O system to measure some thermodynamic properties important for the analysis of solid-liquid phase equilibria in these important semiconductor materials. The standard Gibbs energies of formation of the most stable oxides of gallium and of indium are determined with a high-temperature solid-state electrochemical cell utilizing calcia-stabilized zirconia as the solid electrolyte and a (CO + CO/sub 2/) gaseous mixture as the refere… more
Date: October 1, 1978
Creator: Anderson, T. J.
Partner: UNT Libraries Government Documents Department
open access

Chemistry of coal model compounds: cleavage of aliphatic bridges between aromatic nuclei catalyzed by Lewis acids.

Description: The condensed polynuclear aromatic clusters of coal are believed to be linked principally by straight-chain aliphatic bridges varying from 0 to 4 carbon atoms in length and the cleavage of these linkages is expected to be an important step in the coal liquefaction process. This study focuses on the means by which Lewis acid catalysts, specifically AlCl/sub 3/ and ZnCl/sub 2/, promote the cleavage of these linkages. To facilitate product identification and interpretation of reaction mechanisms, … more
Date: April 1, 1978
Creator: Taylor, N. D.
Partner: UNT Libraries Government Documents Department
open access

Flow cytometric analysis of mitotic cycle perturbation by chemical carcinogens in cultured epithelial cells. [Effects of benzo(a)pyrene-diol-epoxide on mitotic cycle of cultural mouse liver epithelial cells]

Description: A system for kinetic analysis of mitotic cycle perturbation by various agents was developed and applied to the study of the mitotic cycle effects and dependency of the chemical carcinogen benzo(a)pyrene-diolepoxide, DE, upon a mouse lever epithelial cell line, NMuLi. The study suggests that the targets of DE action are not confined to DNA alone but may include cytoplasmic structures as well. DE was found to affect cells located in virtually every phase of the mitotic cycle, with cells that were… more
Date: August 1, 1978
Creator: Pearlman, A.L.
Partner: UNT Libraries Government Documents Department
open access

Equation of state and transport measurements on expanded liquid metals up to 8000/sup 0/K and 0. 4 GPa

Description: Equilibrium measurements of pressure, enthalpy, density, temperature and resistivity have been made on liquid lead, platinum, gold-copper, uranium, niobium, and niobium-hafnium at high temperatures and pressures. A unique method of determining sample temperatures from multi-channel fast radiation pyrometry has been developed and used to calculate temperatures between 1600 and 8000 K without definitive emissivity information. Pseudo-potential theory has been used to model the lead resistivity an… more
Date: May 1, 1978
Creator: Hodgson, William Mark
Partner: UNT Libraries Government Documents Department
open access

Analysis and Development of FACE Automatic Apparatus for Rapid Identification of Transuranium Isotopes

Description: A description of and operating manual for the FACE Automatic Apparatus has been written along with a documentation of the FACE machine operating program, to provide a user manual for the FACE Automatic Apparatus. In addition, FACE machine performance was investigated to improve transuranium throughput. Analysis of the causes of transuranium isotope loss was undertaken both chemical and radioactive. To lower radioactive loss, the dynamics of the most time consuming step of the FACE machine, the … more
Date: September 1, 1978
Creator: Sebesta, E.H.
Partner: UNT Libraries Government Documents Department
open access

SUPERCONDUCTING TRANSITION EDGE BOLOMETER AND NOISE IN THIN FILMS

Description: We report the development of the composite superconducting transition edge bolometer. The temperature sensitive element is an aluminum strip evaporated onto the sapphire substrate. A bismuth film evaporated on the reverse side of the substrate is used to absorb the submillimeter radiation. The noise limitation of the bolometer is calculated. The fabrication and measured performance are described. The best electrical NEP (noise-equivalent-power) obtained is (1.7 {+-} 0.1) x 10{sup -15} WHz{sup -… more
Date: June 1, 1978
Creator: Yeh, Nan-Hsiung
Partner: UNT Libraries Government Documents Department
open access

ELECTROCHEMICAL MACHINING OF CARBIDES AND BORIDES

Description: The use of high rate anodic dissolution (electrochemical machining) for shaping titanium carbide, zirconium carbide, titanium boride and zirconium boride has been investigated in 2N potassium nitrate and 3N sodium chloride under current densities ranging from 20 to 120 A/cm{sup 2} (corresponding to cutting rates of 0.3 to 1.8 mm/min). The dissolution stoichiometry for all these materials is independent of the current density in the range 20 to 120 A/cm{sup 2}. Both titanium and zirconium appear… more
Date: July 1, 1978
Creator: Dissaux, Bernard Antoine; Muller, Rolf H. & Tobias, Charles W.
Partner: UNT Libraries Government Documents Department
open access

CONTAMINATION OF GROUNDWATER BY ORGANIC POLLUTANTS LEACHED FROM IN-SITU SPENT SHALE

Description: The potential for contamination of groundwater by organic pollutants leached from in-situ spent shale was studied in a series of laboratory leaching experiments. Both batch-mode and continuous-flow column experiments were conducted to study the leaching phenomenon. Experimental variables included retorting characteristics of spent shale, leaching time, initial quality of leach water, temperature of leach water, and particle size of spent shale. Several unique samples of spent shale were examine… more
Date: June 1, 1978
Creator: Amy, Gary L.
Partner: UNT Libraries Government Documents Department
open access

Catalytic Conversion of Solvent Refined Coal to Liquid Products

Description: Catalytic reactions of solvent refined coal (SRC) were studied using mixed metal oxide and low melting Lewis acid catalysts in extracting solvent media. From characterization of the benzene- and cyclohexane-soluble products, ZnCl/sub 2/ and SnCl/sub 2/ were determined to be the most effective at hydrogenating and solubilizing SRC while assisting in heteroatom removal. ZnCl/sub 2/ and SnCl/sub 2/ were also found to be more effective at producing oil-like products rather than alphaltene-like prod… more
Date: February 1, 1978
Creator: Tanner, K. I. & Bell, A. T.
Partner: UNT Libraries Government Documents Department
open access

Turbulent heat transport in two- and three-dimensional temperature fields

Description: A fundamental numerical study of turbulent heat and mass transport processes in two- and three-dimensional convective flows is presented. The model of turbulence employed is the type referred to as a second-order closure. In this scheme transport equations for all nonzero components of the Reynolds stress tensor, for the isotropic dissipation rate of turbulent kinetic energy, for all nonzero scalar flux tensor components and for the mean square scalar fluctuations are solved by a finite differe… more
Date: March 1, 1978
Creator: Samaraweera, D. S. A.
Partner: UNT Libraries Government Documents Department
open access

REDUCTION OF NITRIC OXIDE BY CARBON MONOXIDE OVER A SILICA SUPPORTED PLATINUM CATALYST: INFRARED AND KINETIC STUDIES

Description: The reduction of nitric oxide by carbon monoxide over a 4.5 weight precent platinum catalyst supported on silica was studied at 300 C. Reaction rate data was obtained together with in situ infrared spectra of species on the catalyst surface. The kinetics of the system were found to exhibit two distinct trends, depending on the molar ratio of CO/NO in the reactor. For net reducing conditions (CO/NO> 1) the catalyst underwent a transient deactivation, the extent of which was dependent on the s… more
Date: August 1, 1978
Creator: Lorimer, D.H.
Partner: UNT Libraries Government Documents Department
open access

Process development studies for the production of. beta. -glucosidase from Aspergillus phoenicis

Description: This work is concerned with the production of ..beta..-glucosidase from Aspergillus phoenicis for use in the enzymatic hydrolysis of cellulose. Kinetic growth data indicate that two distinct periods of growth exist. The observed growth kinetics result from a biochemical differentiation of the filament which is independent of the substrate concentration. The optimum temperature for cell mass and ..beta..-glucosidase production was found to be 30/sup 0/C. The optimum pH for ..beta..-glucosidase p… more
Date: September 1, 1978
Creator: Howell, M. J. & Wilke, C. R.
Partner: UNT Libraries Government Documents Department
open access

Utilization of immobilized B-glucosidase in the enzymatic hydrolysis of cellulose

Description: ..beta..-glucosidase obtained from Aspergillus phoenicis was immobilized onto phenol formaldehyde resin using glutaraldehyde as a fixing agent, and kinetic characteristics such as pH optimum, temperature stability and Michaelis-Menton constants were determined. Three experiments were performed where a batch hydrolysis of a cellulosic source was carried out with a recycle stream through an immobilized ..beta..-glucosidase column in order to continuously remove cellobiose. The first two experimen… more
Date: January 1, 1978
Creator: Issacs, S. H. & Wilke, C. R.
Partner: UNT Libraries Government Documents Department
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