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Low Temperature Surface Carburization of Stainless Steels

Description: Low-temperature colossal supersaturation (LTCSS) is a novel surface hardening method for carburization of austenitic stainless steels (SS) without the precipitation of carbides. The formation of carbides is kinetically suppressed, enabling extremely high or colossal carbon supersaturation. As a result, surface carbon concentrations in excess of 12 at. % are routinely achieved. This treatment increases the surface hardness by a factor of four to five, improving resistance to wear, corrosion, and… more
Date: December 7, 2007
Creator: Collins, Sunniva R.; Heuer, Arthur H. & Sikka, Vinod K.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Comparisons of hydrodynamic beam models with kinetic treatments. Revision 1

Description: Hydrodynamic models have been derived by Mark and Yu and by others to described energetic self-pinch beams, such as those used in ion-beam fusion. The closure of the Mark-Yu model is obtained with adiabatic assumptions mathematically analogous to those of Chew, Goldberger, and Low for MHD. The other models treated here use an ideal gas closure and a closure by Newcomb based on an expansion in V/sub th//V/sub z/. Features of these hydrodynamic beam models are compared with a kinetic treatment.
Date: December 21, 1983
Creator: Boyd, J. K.; Mark, J. W.; Sharp, W. M. & Yu, S. S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Modeling pCO sub 2 in the upper ocean

Description: This report summarizes our current understanding of the physical, chemical, and biological processes that control the natural cycling of carbon dioxide (CO{sub 2}) in the surface ocean. Because the physics of mixing at the ocean surface creates the essential framework for the chemistry and biology, and because the literature on surface ocean mixing is extensive, a major focus of the report is to review existing mixed layer models for the upper ocean and their implementation in global ocean circ… more
Date: December 1, 1990
Creator: Archer, D.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Calculations of volatilities of Hg, NH{sub 3}, and Cs-137 in the F/H Effluent Treatment Facility evaporator system

Description: An evaporator will be used in the F/H Effluent Treatment Facility (F/H ETF) to reduce the volume of effluent dispensed to Upper Three Runs Creek and to concentrate solutions from three sources in the F/H ETF before sending that waste to Saltstone. The evaporator will be fed by backwash from the filters in the filtration unit, the concentrate stream from reverse osmosis, and the solutions used in regeneration of ion exchange columns. These streams will contain small amounts of Hg, NH{sub 3}, and… more
Date: December 20, 1985
Creator: Wallace, R. M. & Bibler, J. P.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Control of high level radioactive waste-glass melters. Part 5, Modelling of complex redox effects

Description: Slurry Fed Melters (SFM) are being developed in the United States, Europe and Japan for the conversion of high-level radioactive waste to borosilicate glass for permanent disposal. The high transition metal, noble metal, nitrate, organic, and sulfate contents of these wastes lead to unique melter redox control requirements. Pilot waste-glass melter operations have indicated the possibility of nickel sulfide or noble-metal fission-product accumulation on melter floors, which can lead to distorti… more
Date: December 31, 1991
Creator: Bickford, D. F. & Choi, A. S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Evaluation of Wax Deposition and Its Control During Production of Alaska North Slope Oils

Description: Due to increasing oil demand, oil companies are moving into arctic environments and deep-water areas for oil production. In these regions of lower temperatures, wax deposits begin to form when the temperature in the wellbore falls below wax appearance temperature (WAT). This condition leads to reduced production rates and larger pressure drops. Wax problems in production wells are very costly due to production down time for removal of wax. Therefore, it is necessary to develop a solution to wax… more
Date: December 31, 2008
Creator: Zhu, Tao; Walker, Jack A. & Liang, J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

A thermodynamic model of the hydrolysis of microcline in acid sulfate solutions

Description: A theoretical model of the hydrolysis of microcline by a hydrothermal solution has been determined for a closed system at constant temperature. Hypothetical solution compositions and temperatures were chosen to match the known geothermal system at Roosevelt Hot Springs, Utah. The calculated reaction paths indicate that the overall reaction process is an exchange of potassium from the reactant mineral, microcline, for hydrogen from the solution. Aluminum is nearly conserved among solid phases. T… more
Date: December 1, 1976
Creator: Dedolph, R.E. & Parry, W.T.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Thermodynamic property evaluation and magnetic refrigeration cycle analysis for gadolinium gallium garnet

Description: Based on relevant material property data and previous model formulations, a magnetothermodynamic property map for gadolinium gallium garnet (Gd{sub 3}Ga{sub 5}O{sub 12}) was adapted for refrigeration cycle analysis in the temperature range 4-40 K and the magnetic field range 0-6 T. Employing methods similar to those previously developed for other materials and temperature ranges, assessments of limitations and relative performance were made for Carnot, ideal regenerative, and pseudo-constant fi… more
Date: December 1, 1994
Creator: Murphy, R. W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Separation of Fischer-Tropsch wax from catalyst by supercritical extraction. Quarterly report, July 1, 1996 - September 30, 1996

Description: The objective of this research projects is to evaluate the potential of SCF extraction for separating the catalyst slurry of a Fischer- Tropsch (F-T) slurry bubble column (SBC) reactor into two fractions: (1) a catalyst-free wax containing less than 10 ppm particulate matter and (2) a concentrated catalyst slurry that is ready for recycle or regeneration. The wax will be extracted with a hydrocarbon solvent that has a critical temperature near the operating temperature of the SBC reactor, i.e. … more
Date: December 31, 1996
Creator: Joyce, P. C.; Thies, M. C.; Sherrard, D.; Biales, J.; Kilpatrick, P. & Roberts, G.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

An analytical method of predicting Lee-Kesler-Ploecker binary interaction coefficients: Part 1, For non-polar hydrocarbon mixtures

Description: An analytical method is proposed for finding numerical values of binary interaction coefficients for non-polar hydrocarbon mixtures when the Lee-Kesler (LK) equation of state is applied. The method is based on solving simultaneous equations, which are Ploecker`s mixing rules for pseudocritical parameters of a mixture, and the Lee-Kesler equation for the saturation line. For a hydrocarbon mixture, the method allows prediction of {kappa}{sub ij} interaction coefficients (ICs) which are close to v… more
Date: December 31, 1994
Creator: Sand, J.R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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