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Lot No. 2 of Frit 202 for DWPF cold runs

Description: In the DWPF (Defense Waste Processing Facility), glass forming chemicals will be added to the waste in the form of premelted glass frit. On an oxide weight basis, DWPF glass will consist of approximately 64 wt% glass frit, 8 wt% precipitate hydrolysis aqueous product, and 28 wt% sludge. The glass frit and the precipitate hydrolysis aqueous product together make up what is called the glass-former composition. Current plants are to control the composition of the frit through the procurement speci… more
Date: April 5, 1993
Creator: Schumacher, R. F.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Catalytic hydrocarbon reactions over supported metals. Progress report, February 1, 1992--March 31, 1993

Description: During the past year we have completed our characterization of the factors that control the structure of fully oxidized W and Mo on silica and have established that support hydroxyl groups play a central role in dispersing and attaching cations to the support oxide. Work with M{sub 2}(CO){sub 4}Cp{sub 2}(M{sub 2}=MoMo, WW, MoW) system has been very encouraging and continues to support the notion that it may be possible to control the structure of adsorbed catalysts (in this case generate metal … more
Date: March 29, 1993
Creator: Ekerdt, J. G.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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A literature review of surface alteration layer effects on waste glass behavior

Description: When in contact with an aqueous solution, nuclear waste glass is subject to a chemical attack that results in progressive alteration. During tills alteration, constituent elements of the glass pass into the solution; elements initially in solution diffuse into, or are adsorbed onto, the solid; and new phases appear. This results in the formation of surface layers on the reacted glass. The glass corrosion and radionuclide release can be better understood by investigating these surface layer effe… more
Date: May 1, 1993
Creator: Feng, X.; Cunnane, J. C. & Bates, J. K.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Surfactant loss control in chemical flooding: Spectroscopic and calorimetric study of adsorption and precipitation on reservoir minerals. Quarterly technical progress report, January 1, 1993--March 31, 1993

Description: The aim of this project is to elucidate the mechanisms of adsorption and surface precipitation of flooding surfactants on reservoir minerals. Effect of surfactant structure, surfactant combinations and other inorganic and polymeric species will be determined using solids of relevant mineralogy. A multi-pronged approach consisting of micro & nano spectroscopy, microcalorimetry, electrokinetics, surface tension and wettability win be used to achieve the goals. The results of this study should hel… more
Date: May 1, 1993
Creator: Somasundaran, P.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The role of interfacial chemistry in surface nucleation and growth of calcium oxalate

Description: The surface adsorption of Ca{sup 2+} and oxalate anions (Ox{sup 2{minus}}) on SiO{sub 2}, TiO{sub 2} and Al{sub 2}O{sub 3} oxide colloids were by electrosonic amplitude measurements. Kinetics studies of CaO{sub x} formation on the model oxide surfaces were carried out using constant composition method. Results suggested Ca{sup 2+} and Ox{sup 2{minus}} adsorptiopn was promoted on the oxide surfaces with opposite charges, and the specific adsorption of the divalent ions also resulted in surface c… more
Date: June 1, 1993
Creator: Song, L.; Campbell, A. A. & Bunker, B. C.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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NMR measurement of pore structure

Description: An attempt was made to pursue {sup 129}Xe NMR as a pore measurement technique. Samples studied were synthetic imogolite (tubular aluminosilicate with gibbsite structure), sodium Y-zeolite, and an aerogel and a xerogel. Gases used were normal Xe, {sup 13}CO{sub 2}, and {sup 15}N{sub 2}. Although a completely general NMR technique for measuring pore size distributions may not be possible, information about molecular motion and interactions can be obtained, because NMR is sensitive to short range … more
Date: May 31, 1993
Creator: Earl, W. L.; Kim, Yong-Wah & Smith, D. M.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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[Diffusion/dispersion transport of chemically reacting species]. Progress report, FY 1992--1993

Description: Progress is reported on the following: calculation of activity coefficients for aqueous silica in alkali metal chloride solutions; calculation of degrees of formation of polyatomic clusters of Al in alkali chloride solutions; bulk composition-pH diagrams for arkosic sediments; and chemical interaction of petroleum, oil field brines, and authigenic mineral assemblages. Plans for future research are given.
Date: July 1, 1993
Creator: Helgeson, H. C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Dielectric properties and electronic applications of aerogels

Description: Among their other exceptional properties, aerogels also exhibits unusual dielectric properties due to their nano-sized structures and high porosities. For example, our measurements of the dielectric constants and loss tangents for several aerogel varieties at microwave frequencies show that they both vary linearly with the aerogel density, indicating that the dielectric behavior of aerogels is more gas-like than solid-like. We have also measured the dielectric strength of silica aerogels and fi… more
Date: July 1, 1993
Creator: Hrubesh, L. W. & Pekala, R. W.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Tritium release from beryllium discs and lithium ceramics irradiated in the SIBELIUS experiment

Description: The SIBELIUS experiment was designed to obtain information on the compatibility between beryllium and ceramics, as well as beryllium and steel, in a neutron environment. This experiment comprised irradiation of eight capsules, seven of which were independently purged with a He/0.1% H{sub 2} gas mixture. Four capsules were used to examine beryllium/ceramic (Li{sub 2}O, LiAlO{sub 2}, Li{sub 4}SiO{sub 4}, and Li{sub 2}ZrO{sub 3}) and beryllium/steel (Types 316L and 1.4914) compacts. Isothermal ann… more
Date: November 1, 1993
Creator: Johnson, C. E.; Kopasz, J. P. & Baldwin, D. L.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Coal Ash Behavior in Reducing Environments

Description: A series of tests have been conducted on two coals with the PDTF under various conditions (temperatures ranging from 1100{degree} to 1500{degree}C, pressures ranging from 50 to 100 psi, O/C ratios ranging from 1.0 to 2.0, and residence times ranging from 5 to 13 seconds). In summary, the results from the pressurized drop-tube furnace testing show differences in the inorganic transformations as a function of temperature residence time and coal type. The gas atmosphere and pressure did not have a… more
Date: September 1, 1993
Creator: Benson, S. A.; Erickson, T. A.; Brekke, D. W.; Folkedahl, B. C.; Tibbetts, J. E. & Nowok, J. W.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Shock compression of low-density foams

Description: Shock compression of very low density micro-cellular materials allows entirely new regimes of hot fluid states to be investigated experimentally. Using a two-stage light-gas gun to generate strong shocks, temperatures of several eV are readily achieved at densities of roughly 0.5--1 g/cm{sup 3} in large, uniform volumes. The conditions in these hot, expanded fluids are readily found using the Hugoniot jump conditions. We will briefly describe the basic methodology for sample preparation and exp… more
Date: July 1, 1993
Creator: Holmes, N. C.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Transient studies of low temperature catalysts for methane conversion

Description: This report summarizes studies conducted during the past quarter on the partial oxidation of methane on the following catalysts: vanadium phosphate, unsupported and supported on silica, and on the silica (SiO[sub 2]) support. It was found that the unsupported vanadium phosphate catalyst exhibits some selectivity towards formaldehyde at relatively low methane conversions (up to 5% conversion). The selectivity decreases even further on the silica supported VPO catalyst without a significant incre… more
Date: January 1, 1993
Creator: Wolf, E. E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Preparation of H{sub 2}-Permselective Silica Membranes by Alternating Reactant Deposition. Quarterly Progress Report, September 1, 1993--December 31, 1993

Description: Thin SiO{sub 2} layers were deposited on the surface of porous Vycor glass by alternating vapor phase reaction with SiCl{sub 4} and H{sub 2}O. The membranes prepared by this technique had H{sub 2} permeance of 0.3--0.4 cm{sup 3} (STP)/(min{center_dot}cm{sup 2}{center_dot}atm) and H{sub 2}:N{sub 2} selectivity of 500--1000 at 600{degrees}C. The SiCl{sub 4} dosage at each silylation cycle, the concentration of initial surface -OH groups, and the reaction temperature influence significantly the de… more
Date: December 31, 1993
Creator: Kim, Soojin & Gavalas, G. R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Silica Membranes for Hydrogen Separation From Coal Gas. Quarterly Progress Report, December 1, 1992--February 28, 1993

Description: A new reactor system was constructed which can be used for CVD Of SiO{sub 2} layers on porous Vycor tubes. The system is suitable for the usual one-sided deposition and for alternating (or layer-by-layer) deposition whereby the silylating agent and water are passed one at a time in alternating periods. The main advantage of alternating deposition is that it allows membrane deposition using silica precursors for which the homogeneous hydrolysis is fast. As we have demonstrated in earlier work, f… more
Date: April 15, 1993
Creator: Gavalas, G. R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Reduced optical transmission of SiO{sub 2} fibers used in controlled fusion diagnostics

Description: We have subjected a silica core fiber optic cable to 4 years of low-level neutron and gamma radiation from Princeton`s TFTR controlled fusion experiment The accumulated dose was 200 Gy. As a result of the radiation, we have measured increased attenuations of 100--300 db/km in the visible part of the spectrum, and a decrease of the numerical aperture. An attempt to decrease this damage by photobleaching failed. We argue that this failure is not unexpected, since the rate of damage is so slow and… more
Date: February 1, 1993
Creator: Ramsey, A. T.; Adler, H. G. & Hill, K. W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Characterization of defects in Si and SiO{sub 2}-Si using positrons

Description: Positron annihilation spectroscopy of overlayers, interfaces, and buried regions of semiconductors has seen a rapid growth in recent years. The characteristics of the annihilation gamma rays depend strongly on the local environment of the annihilation sites, and can be used to probe defect concentrations in a range inaccessible to conventional defect probes. Some of the recent success of the technique in examining low concentrations of point defects in technologically important Si-based structu… more
Date: December 31, 1993
Creator: Asoka-Kumar, P. & Lynn, K. G.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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H2O{underscore}TREAT users` manual: An aid for evaluating water treatment requirements for aquifer thermal energy storage systems

Description: This manual addresses the use of a public-domain software package developed to aid engineers in the desip of water treatment systems for aquifer thermal energy storage (ATES). The software, H20{underscore}TREAT, which runs in the DOS or UNIX Environment, was developed by the Pacific Northwest Laboratory and targeted to engineers possessing limited or no experience in geochemistry. To do this, the software provides guidance on geochemical phenomena that can cause problems in ATES systems (i.e., … more
Date: February 1, 1993
Creator: Vail, L. W.; Jenne, E. A.; Zipperer, J. P. & McKinley, M. I.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Alkaline assisted thermal oil recovery: Kinetic and displacement studies

Description: This report deals with two major issues of chemical assisted flooding - the interaction of caustic, one of the proposed additives to steam flood, with the reservoir rock, and the displacement of oil by a chemical flood at elevated temperatures. A mathematical model simulating the kinetics of silica dissolution and hydroxyl ion consumption in a typical alkaline flooding environment is first developed. The model is based on the premise that dissolution occurs via hydrolysis of active sites throug… more
Date: June 1, 1993
Creator: Saneie, Shahrouzeh & Yortsos, Yanis C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Investigation of the effects of polyelectrolyte coatings on colloid transport in porous media. Progress report, August 1, 1992--July 31, 1993

Description: Goal is to study the repulsive interaction forces between humic- coated colloids and negatively charged porous media surfaces. Filtration experiments were carried out on hematite coated with humic acid or NOM, in porous media or packed bed (silica bed). Effects of Ca{sup 2+} are being studied. Results so far indicate that many humic coating properties (molecular size, acidity, polarity, surface conformation) have an important effect on colloid attachment rates but very little effect on colloid … more
Date: August 1, 1993
Creator: Olson, T. M.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Enhanced thermal capacity aerogels summary report for FY 1993

Description: In a continuation of work done previously, the authors have fabricated a set of silica aerogels and then chemically modified their internal surfaces for the purpose of inhibiting the effects of sintering at high temperatures. They performed surface nitridation of silica aerogels, i.e., the replacement of surface oxygen atoms with nitrogen atoms, by reacting ammonia gas with the silica surfaces at elevated temperatures. After pre-oxidizing the aerogels, they exposed three sets of samples to anhy… more
Date: December 1, 1993
Creator: Hrubesh, L. W.; Coronado, P. R. & Poco, J. F.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Kinetics of silica-phase transitions

Description: In addition to the stable silica polymorph quartz, several metastable silica phases are present in Yucca Mountain. The conversion of these phases to quartz is accompanied by volume reduction and a decrease in the aqueous silica activity, which may destabilize clinoptilolite and mordenite. The primary reaction sequence for the silica phases is from opal or glass to disordered opal-CT, followed by ordering of the opal-CT and finally by the crystallization of quartz. The ordering of opal-CT takes … more
Date: July 1, 1993
Creator: Duffy, C.J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Hot isostatically-pressed aluminosilicate glass-ceramic with natural crystalline analogues for immobilizing the calcined high-level nuclear waste at the Idaho Chemical Processing Plant

Description: The additives Si, Al, MgO, P{sub 2}O{sub 5} were mechanically blended with fluorinelsodium calcine in varying proportions. The batches were vacuum sealed in stainless steel canisters and hot isostatically pressed at 20,000 PSI and 1000 C for 4 hours. The resulting suite of glass-ceramic waste forms parallels the natural rocks in microstructural and compositional heterogeneity. Several crystalline phases ar analogous in composition and structure to naturally occurring minerals. Additional crysta… more
Date: December 1, 1993
Creator: Raman, S.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Silica Membranes for Hydrogen Separation From Coal Gas

Description: A new reactor system was constructed which can be used for CVD Of SiO[sub 2] layers on porous Vycor tubes. The system is suitable for the usual one-sided deposition and for alternating (or layer-by-layer) deposition whereby the silylating agent and water are passed one at a time in alternating periods. The main advantage of alternating deposition is that it allows membrane deposition using silica precursors for which the homogeneous hydrolysis is fast. As we have demonstrated in earlier work, f… more
Date: April 15, 1993
Creator: Gavalas, G. R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Silica Membranes for Hydrogen Separation in Coal Gas Processing

Description: The general objective of this project was to synthesize permselective membranes suitable for hydrogen separation from coal gas. The specific objectives were: (i) to synthesize membranes by chemical vapor deposition (CVD) of SiO[sub 2] or other oxides on porous support tubes, (ii) characterize the membranes by permeation measurements of various gases and by electron microscopy, and (iii) obtain information about the mechanism and kinetics Of SiO[sub 2] deposition, and model the process of membra… more
Date: January 1, 1993
Creator: Gavalas, G. R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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