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Showing 1 to 20 of 237 for “"zirconia"”.
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Characterization and Catalytic Properties of Sulfated Zirconia
<p>Sulfated zirconia has attracted extensive attention due to its superactivity to isomerize alkane and alkenes. Platinum or iron/manganese promoted sulfated zirconia has been shown to increase the reaction rate. These catalysts are normally activated to 650-725°C in air before use. Through on-line …
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Chemistry of Zirconia and Its Bioanalytical Applications
This research studies the chemical nature of zirconia and the complex surface chemistry of zirconia in order to better comprehend its behavior under chromatographic conditions. This research shows how the physical and chemical properties of zirconia depend strongly on the thermal treatment during …
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Exploring Zirconia as a Column Packing Material
Zirconia is one of the most promising column packing materials for High Performance Liquid Chromatography (HPLC). The perfect HPLC support material should be energetically homogenous, have a high surface area on which different chemical species can reversibly attach and be physically and chemically …
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Mechanisms of Flash Sintering in Cubic Zirconia
… sintering of cubic 8 mol% yttria stabilized zirconia (8YSZ). This materials has been selected because it was one of the first materials show flash sintering properties, and that it has been very well characterized because of its use as a fast oxygen ion conductor. This work began with the …
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Low-energy excitations in yttria-stabilized zirconia
Thermal conductivity, specific heat, dielectric constant and thermal expansion measurements below 2 K on single crystal samples of Zr02 :Y203 with 10.5, 16 and 18 mole % Y2O3 contents exhibit properties typical of glasses. The presence of glass-like excitations having a broad spectrum of energies …
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Transformation-mismatch plasticity in zirconia ceramic composites
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 1997.
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Partial Oxidation of Hydrocarbons Over Ceria Zirconia Catalysts
… Next, methane partial oxidation over ceria zirconia catalysts is studied with infrared spectroscopy. Methane and oxygen concentrations are modulated to differentiate active and spectator species via modulation excitation spectroscopy. Aromatic and alkoxy surface species modulate in sync with …
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Pressureless infiltrated alumina and zirconia based steel - MMCs
Alumina and zirconia based steel-MMCs were produced by pressureless Ti-activated melt infiltration using a high vacuum furnace. The effect of particle size and morphology on the formation of a ceramic network in-situ and MMC properties were investigated using three different alumina powders. The …
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Sintering Kinetics of Ultra-Fine Calcia Stabilized Zirconia
Made available in DSpace on 2014-12-10T17:32:36Z (GMT). No. of bitstreams: 1 6801887.pdf: 3471989 bytes, checksum: 695b31d9017c760d48c0eb76200a5bf1 (MD5) Previous issue date: 1967
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Supramolecular templating of mesoporous zirconia-based nanocomposite catalysts
… catalysts but they suffer from deactivation. Zirconia is of particular interest in acid catalysis because its surface acidic properties can be flexibly tailored. However, the zirconia-based materials typically have low surface areas and poorly controlled textural properties. This thesis …
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An investigation of low expansion cordierite-zirconia bodies
… could be increased by the addition of zirconia without increasing the thermal expansion above 4.0 x 10⁻⁶ cm./cm./°c. A procedure has been presented for making the compound cordierite. Several raw batch compositions which can be expected to produce a high percentage of relatively pure …
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Influence of Orthodontic Bracket Bonding Protocol on Zirconia Ceramics and Resulting Bond Strength, Adhesive Remnant, and Debonded-Polished Zirconia Surface Roughness
… for metal orthodontic brackets bonded to zirconia ceramic and resulting shear bond strength (SBS), adhesive remnant index (ARI), and debonded and polished zirconia surface roughness. Methods: Zirconia specimens were milled, glazed, embedded in acrylic resin and the target area microetched …
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Effect of ceria and zirconia on nanoparticulate rhodium catalysts
… at 1.6 Rh and 4 wt % Rh loading. Ceria and zirconia have been deposited on the pre-supported Rh catalysts by the controlled surface reaction between the reduced Rh surface and an organometallic precursors: Zr(acac)4 and Ce(acac)3, with different cerium : zirconium ratios: Ce:Zr;1:0, 1:1, …
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Reaction sintering of yttria stabilized zirconia via nickel oxide
Includes bibliographical references (pages 49-52).
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Phase Equilibria Studies in the System Magnesia - Alumina - Zirconia
Made available in DSpace on 2014-12-10T17:32:34Z (GMT). No. of bitstreams: 1 6503173.pdf: 8958432 bytes, checksum: 8bb2ae70a1597347d489ee3e30894cb5 (MD5) Previous issue date: 1964
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Comparative study of physical properties of zirconia based dental ceramics
… yttria partially stabilized tetragonal zirconia polycrystalline (Y-TZP) ceramics, which have generated interest in restorative dentistry because of their high strength and high resistance to fracture. Mechanical properties of three commercial Y-TZP ceramics (Lava™, Cercon® and Invizion™) …
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Effect of sintering protocols on zirconia with various YTTRIA concentrations
… of different yttria concentrations of Tosoh zirconia materials (TZ-3YSB-E, TZ-3YB-E, Zpex, and Zpex Smile). MATERIALS AND METHODS: A total of 242 zirconia discs were manufactured from commercially available Tosoh zirconia powders. Zpex smile, Zpex, TZ-3YB-E, and TZ-3YSB-E were uniaxially dry …
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Electrical Conductivity and Defect Structure of Ceria - Zirconia Solid Solutions
Made available in DSpace on 2014-12-10T17:32:38Z (GMT). No. of bitstreams: 1 6915303.pdf: 2735266 bytes, checksum: ec8ad9d7fca8762f98afcd2986b0d24b (MD5) Previous issue date: 1969
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Microstructure development in alkoxide-derived mullite and mullite/zirconia composites
Made available in DSpace on 2011-05-07T13:05:51Z (GMT). No. of bitstreams: 2 license.txt: 4922 bytes, checksum: 910b249b4beec47e7ab768910c8f966f (MD5) 9503362.pdf: 6061044 bytes, checksum: a80d4cfd87ff6cfa07c6e501b0ab11c4 (MD5) Previous issue date: 1994
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