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Electron-Irradiation-Induced Crystallization of Amorphous Orthophosphates

Description: Amorphous LaPO{sub 4}, EuPO{sub 4}, GdPO{sub 4}, ScPO{sub 4}, and fluorapatite [Ca{sub 5}(PO{sub 4}){sub 3}F] were irradiated by electron beam in a TEM. Irradiations were done at -150 to 300 C, 80 to 200 keV, and current densities from 0.3 to 16 A/cm{sup 2}. In all cases, the materials crystallized to form a randomly oriented polycrystalline assemblage. Crystallization is driven dominantly by inelastic processes, although ballistic collisions with target nuclei can be important above 175 keV, p… more
Date: December 1, 1996
Creator: Meldrum, A.; Ewing, R. C. & Boatner, L. A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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The effects of thermal cycling on the physical and mechanical properties of [NZP] ceramics

Description: The [NZP] ceramics, sodium zirconium phosphate and its crystal structure analogs, are noted for their very low thermal expansion characteristics. What has not been widely studied is the effect of thermal cycling on physical and mechanical properties. Two [NZP] compositional series were selected (Ba{sub 1+x}Zr{sub 4}P{sub 6{minus}2x}Si{sub 2x}O{sub 24} and Ca{sub 1{minus}x}Sr{sub x}Zr{sub 4}P{sub 6}O{sub 24}) that exhibit varying bulk thermal expansion from positive to negative and varying degre… more
Date: December 31, 1994
Creator: Jackson, T.B.; Limaye, S.Y. & Porter, W.D.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Airborne Radioactivity Surveys for Phosphate in Florida

Description: Report discussing airborne radioactivity surveys, aimed at finding uraniferous phosphate deposits, in ten areas of Florida. A subsequent ground investigation of two radioactivity anomalies out of eight was conducted. Information on radioactivity measurements for each area is given as well as conclusions.
Date: August 1953
Creator: Moxham, R. M.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Rare Earth Phosphate Glass and Glass-Ceramic Proton Conductors

Description: The structure and conductivity of cerium and lanthanum phosphate glasses and glass-ceramics were investigated. The effects of varying the metal to phosphate ratio in the glasses, doping LaP3O9 glasses with Ce, and recrystallization of CeP3O9 glasses, on the glasses' microstructure and total conductivity were investigated using XRD, SEM, and AC impedance techniques. Strong increases in conductivity occurred when the glasses were recrystallized: the conductivity of a cerium metaphosphate glass in… more
Date: December 3, 2008
Creator: De Jonghe, Lutgard C.; Ray, Hannah L. & Wang, Ruigang
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Effect of Inorganic Phosphate on the Morphology and Poly-β-Hydroxybutyrate Content of Azotobacter Vinelandii Atcc 12837

Description: This study was designed to determine the effect of inorganic phosphate in the growth media of A. vinelandii on the synthesis and accumulation of poly-β-hydroxybutyrate (PHB) and cellular morphology. Burk's media with no added phosphate and ten times normal phosphate resulted in altered cells, lower levels of protein, and decreased cell populations. PHB accumulation was much higher in the cultures with no added phosphate; however, the polymer granules differed in appearance from those of normal … more
Date: May 1975
Creator: Collins, Patricia Ann
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Advance concepts for conversion of syngas to liquids. Quarterly progress report No. 4, July 30, 1995--October 29, 1995

Description: Substitution of transition metals for either aluminum and/or phosphorus in the AlPO{sub 4}-11 framework is found to afford novel heterogeneous catalysts for liquid phase hydroxylation of phenol with hydrogen peroxide. AlPO{sub 4}-11 is more active than SAPO-11 and MgAPO-11 for phenol conversion to hydroquinone. The Bronsted acid sites of SAPO-11 and MgAPO-11 may promote the decomposition of hydrogen peroxide to water and oxygen, thus leading to lower phenol conversions. Substitution of divalent… more
Date: February 1, 1996
Creator: Dai, Pei-Shing Eugene; Petty, R.H.; Ingram, C. & Szostak, R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Metal Oxide Decomposition In Hydrothermal Alkaline Sodium Phosphate Solutions

Description: Alkaline hydrothermal solutions of sodium orthophosphate (2.15 < Na/P < 2.75) are shown to decompose transition metal oxides into two families of sodium-metal ion-(hydroxy)phosphate compounds. Equilibria for these reactions are quantified by determining phosphate concentration-temperature thresholds for decomposition of five oxides in the series: Ti(IV), Cr(III), Fe(III, II), Ni(II) and Zn(II). By application of a computational chemistry method General Utility Lattice Program (GULP), it i… more
Date: September 24, 2003
Creator: Ziemniak, S. E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Oxidation resistant coatings for ceramic matrix composite components

Description: Corrosion resistant Ca{sub 0.6}Mg{sub 0.4}Zr{sub 4}(PO{sub 4}){sub 6} (CMZP) and Ca{sub 0.5}Sr{sub 0.5}Zr{sub 4}(PO{sub 4}){sub 6} (CS-50) coatings for fiber-reinforced SiC-matrix composite heat exchanger tubes have been developed. Aqueous slurries of both oxides were prepared with high solids loading. One coating process consisted of dipping the samples in a slip. A tape casting process has also been created that produced relatively thin and dense coatings covering a large area. A processing t… more
Date: November 1, 1998
Creator: Vaubert, V. M.; Stinton, D. P. & Hirschfeld, D. A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Prototype development and testing of ultrafine grain NZP ceramics. Final report, July 28, 1995--April 27, 1997

Description: The goal of this project was to demonstrate that a new low-expanding ceramic (Ca{sub 0.6},Mg{sub 0.4})Zr{sub 4}(PO{sub 4}){sub 6}, hereafter referred to as CMZP, could be used as an exhaust manifold liner in off-road diesel engines and provide improved engine efficiency (by permitting higher engine operating temperature). This study has successfully demonstrated this improvement and further engine testing (and possible manufacturing) is presently underway at Caterpillar Inc. Laboratories. Basic… more
Date: August 4, 1997
Creator: Brown, J. J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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SOLUBILITIES OF URANYL AND IRON(III) DIBUTYL AND MONOBUTYL PHOSPHATES IN TBP SOLVENT EXTRACTION SOLUTIONS

Description: The solubilities of uranyl dlbutyl phosphate, uranyl monobutyl phosphate, ferric dibutyl phosphate, and ferric monobutyl phosphate were measured in aqueous nitric acid solutions ranging from 0 to 3 M and in 30% TBP in Amsco 125-82 solution containing 0--0.7 M HNO/sub 3/. For the respective compounds in the aqueous phases, as the acidity increased from 0 to 3 M, the solubilities increased from 0.004 to 0.7 g U/liter, O.O5to 50 g U/liter, <1 to 30 mg Fe(III)/ liter, and 0.003 to 3 g Fe(III)/liter… more
Date: May 1, 1961
Creator: Davis, W. Jr.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Prototype development and testing of ultrafine grain NZP ceramics. Quarterly progress report {number_sign}4, January 28, 1996--April 27, 1996

Description: Caterpillar Inc. continues to develop a slip casting procedure for CMZP (CaMgZr phosphate) exhaust portliners for diesel engines. ZnO was used as additive. Tubes have been cast and fired and initial properties look excellent. 40 lbs of CMZP powder are being prepared for Caterpillar to complete the slip casting of 90 degree elbows.
Date: May 24, 1996
Creator: Brown, J. J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Prototype development and testing of ultrafine grain NZP ceramics. Quarterly technical progress report No. 3, October 28, 1995--January 27, 1996

Description: Caterpillar has been developing advanced low-heat-rejection (LHR) engine designs because by insulating the combustion chamber components for reduced heat rejection, improved fuel economy and emission reduction can be achieved. The insulation eliminates heat loss during the closed portion of the cycle and increases the combustion temperature. Increased combustion temperatures improve emissions by reducing the amount of particulate or smoke. The higher combustion temperatures also provide additio… more
Date: February 8, 1996
Creator: Brown, J. J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Monte Carlo Simulations of Phosphate Polyhedron Connectivity in Glasses

Description: Monte Carlo simulations of phosphate tetrahedron connectivity distributions in alkali and alkaline earth phosphate glasses are reported. By utilizing a discrete bond model, the distribution of next-nearest neighbor connectivities between phosphate polyhedron for random, alternating and clustering bonding scenarios was evaluated as a function of the relative bond energy difference. The simulated distributions are compared to experimentally observed connectivities reported for solid-state two-dim… more
Date: December 21, 1999
Creator: ALAM,TODD M.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Results of Geologic Drilling, 1953, Land-Pebble Phosphate District, Florida

Description: Report discussing the results of geologic drilling of the land-pebble phosphate district in Florida. Specifically, the general geology, stratigraphy, mineralogy, chemistry, weathering, and economic geology are discussed.
Date: January 1956
Creator: Cathcart, James Bachelder & McGreevey, Lawrence J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Hydrothermal Transformation of Microporous Lithium Zinc Phosphates; A Kinetic Study using in situ Synchrotron Radiation Powder Diffraction.

Description: The solution mediated phase transformation of a lithium zinc phosphate has been investigated. The zeolite type ABW phase, LiZnPO{sub 4}. H{sub 2}O, suspended in an aqueous solution of LiNO{sub 3}, transforms to the more dense phase, (delta tau) LiZnPO{sub 4} (crystobalite type structure). In situ time resolved powder diffraction using synchrotron radiation, has been utilized to obtain isothermal crystallization curves in the temperature range 179 {degrees} C to 210 {degrees} C. A power law was … more
Date: December 31, 1997
Creator: Jensen, T. R.; Norby, P. & Hanson, J. C.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Scaling behavior in the conductivity of alkali oxide glasses

Description: Although the frequency dependent conductivity, {sigma}({omega}), of ion-containing glasses displays power law dispersion ({sigma}({omega}) {approx} {omega}{sup n}) that can usually be described by a master curve, several findings have suggested that this scaling fails at low temperatures as indicated by a temperature dependence of the scaling exponent, n. The authors investigate this behavior in the frequency range between 1 Hz and 10{sup 6} Hz for a different materials including alkali metapho… more
Date: November 1, 1995
Creator: Sidebottom, D. L.; Green, P. F. & Brow, R. K.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Recovery of Plutonium From Slag and Crucible

Description: Report evaluating different methods of preparing nitric acid solution and different methods of separating plutonium from this nitric acid solution of slag and crucible. Methods are explained and experimental data is given.
Date: June 15, 1951
Creator: Groot, C.; Hopkins, H. H. & Schulz, W. W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Uraniferous Phosphate Resources and Technology and Economics of Uranium Recovery From Phosphate Resources, United States and Free World: Volume 1. Uraniferous Phosphate Resources, United States and Free World

Description: From abstract: This report summarizes data of the uraniferous phosphate resources of the United States in detail and of the rest of the Free World more generally (Volume 1). It also evaluates the technical, economic, and environmental feasibility of production of uranium as a by-product, co-product, or single product from the uraniferous phosphate resources (Volume 2).
Date: June 1979
Creator: De Voto, Richard H. & Stevens, D. N.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Uraniferous Phosphate Resources and Technology and Economics of Uranium Recovery From Phosphate Resources, United States and Free World: Volume 2. Technology and Economics of Uranium Recovery from Phosphate Resources, United States and Free World

Description: From abstract: This report summarizes data of the uraniferous phosphate resources of the United States in detail and of the rest of the Free World more generally (Volume 1). It also evaluates the technical, economic, and environmental feasibility of production of uranium as a by-product, co-product, or single product from the uraniferous phosphate resources (Volume 2).
Date: June 1979
Creator: De Voto, Richard H. & Stevens, D. N.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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