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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Thermal decomposition of mixed metal oxalates

Coetzee, Anita January 1993 (has links)
The mixed metal oxalates, FeCu(ox)₂.3H₂0, CoCu(ox)₂.3H₂0, and NiCu(ox)₂.3.5H₂0, [ox = C₂0₄] have been prepared by coprecipitation from solution. The thermal behaviour of these compounds in nitrogen and in oxygen has been examined using thermogravimetry (TG), thermomagnetometry (TM), differential scanning calorimetry (DSC) and evolved gas analysis (EGA), and results are compared with results obtained for Cuox and Mox.yH₂0. The thermal behaviour of the mixed oxalates, MCU(OX)₂.xH₂0, differed from that of the individual metal oxalates, Cuox, Coox.2H₂0, Niox.2H₂0 and Feox.2H₂0. All three mixed oxalates on heating in N₂, first dehydrate and then decompose in at least two overlapping endothermic stages. Both CO and CO₂ were evolved in proportions which varied with the surrounding atmosphere, and from compound to compound, and with extent of reaction of a given compound. The mixed oxalates, MCU(OX)₂.xH₂0, do not show the exothermic behaviour characteristic of Cuox, and reasons for this are discussed. Thermochemical calculations were done and the enthalpies of formation of the hydrates and dehydrated oxalates were determined. It was found that the enthalpy of mixing was very small or within experimental error. X-ray powder diffraction patterns for the individual and mixed oxalates were compared. The pattern for Cuox differs from the patterns obtained for the other oxalates, confirming suggestions that Cuox has a structure different to most other transition metal oxalates. The kinetics of dehydration and decomposition of the mixed oxalates were investigated, using isothermal and programmed temperature TG and DSC experiments. The yield and composition of evolved gases during isothermal decomposition were measured and compared with the enthalpy changes. X-ray photoelectron spectroscopy studies provided some information on the electron environment of the metal atoms in the various oxalates.
12

Structure control and characterization of ferroelectric SrBi2Ta2O9 thin films prepared by a modified metal organic decomposition technique. / CUHK electronic theses & dissertations collection

January 2000 (has links)
by Hu Guangda. / "June 2000." / The numerals in the title are subscript. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2000. / Includes bibliographical references (p. 131-141). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.
13

Oxidation & 1, 5-hydride shift of sulfoximine derivatives

Gao, Xuefeng, Harmata, Michael, January 2009 (has links)
Title from PDF of title page (University of Missouri--Columbia, viewed on March 10, 2010). The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Thesis advisor: Dr. Michael Harmata. Includes bibliographical references.
14

Kinetic and mechanistic studies of the thermal decomposition of glycolate and N-Nitrosoiminodiacetic acid in aqueous basic salt solutions : II Phase transfer catalysis in supercritical fluids

Boatright, David L. 05 1900 (has links)
No description available.
15

A study of direct dyes which decompose on prolonged boiling

Shah, Pravinchandra Tricumji January 1959 (has links)
No description available.
16

Molecular modelling applications in crystallization fouling and clay/polymer nanocomposites

Mrayed, Sabri Mohamed Ali, Chemical Sciences & Engineering, Faculty of Engineering, UNSW January 2007 (has links)
The present work used ab initio density functional theory (DFT) to study two different physical phenomena crystallization fouling and clay-based polymer nanocomposites. In the first part, two foulant materials were studied including calcium carbonate, and calcium sulfate. The lattice energy and enthalpy of formations of each crystal system were predicted using DFT methods. The most stable forms of calcium carbonate foul ant, calcite and aragonite, were investigated. For calcium sulfate, both gypsum and anhydrite crystals were investigated. The thermodynamic solubility product of each crystal system, for both foul ants, was predicted from the lattice energy and enthalpy of formations. Comparison of the stability between the different crystal systems for the same foul ant material was carried out to elucidate the effect of crystal atomic configuration and space group on the stability of foulant materials. The effect of temperature on the formation and stability of foulant material was also carried out. The results obtained using DFT methods, for enthalpy of formation and thermodynamic solubility products, were comparable with the experimental data reported in the literature. In the second part, study has been made on the clay-based nylon 6 nanocomposite materials. The purpose was to understand the interfacial interactions between clay and polymer with and without surfactant component. Both sides of the clay were examined with nylon 6. In order to determine specifically the type of interfacial interaction between clay and nylon 6, the electron distribution around the whole system was predicted. The study was carried out at various isomorphic substitutions. The substitutions took place at both octahedral and tetrahedral layers of the clay. The strength between clay and nylon 6 was predicted by calculating the binding energy. The results obtained revealed that, the strength increases with the increase in the degree of isomorphic substitutions. The type of bond between nylon 6 and basal surface of the clay was found to be basically electrostatic interactions, and particularly hydrogen bonds. Whilst, the type of interactions between nylon 6 and clay edge surface was found to include covalent bonds as well as electrostatic interactions. The formation and breakage of covalent bonds between nylon 6 and clay means that, a chemical decomposition of the clay can happen when it is mixed with certain type of polymers. The presence of surfactant can decrease the interfacial interactions between clay and nylon 6.
17

Simulation of a membrane reactor for ammonia decomposition /

Kraisuwansarn, Nichakorn. January 1991 (has links)
Thesis (M.S.)--Oregon State University, 1992. / Typescript (photocopy). Includes bibliographical references (leaves 82-85). Also available on the World Wide Web.
18

The homogenous decomposition of hydrogen peroxide by plutonium (IV)

Elson, Robert E. January 1961 (has links)
Thesis (Ph.D.)--University of California, Berkeley, 1961. / "Chemistry, UC-4" -t.p. "TID-4500 (16th Ed.)" -t.p.
19

An analysis of the thermal decomposition reactions of organic electrolytes used in lithium-ion batteries /

Campion, Christopher Lawrence. January 2005 (has links)
Thesis (Ph. D.)--University of Rhode Island, 2005. / Typescript. Includes bibliographical references (leaves 74-76).
20

I. Significant electronic effects in catalytic asymmetricepoxidation ; II. Peroxynitrite decomposition mediated by ketones andaldehydes

Chen, Jian, 陳健 January 2000 (has links)
published_or_final_version / Chemistry / Doctoral / Doctor of Philosophy

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