"February 2003" / Bibliography: leaves 186-201. / viii, 201, ix, [41] leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Chemistry, 2003

Thèse de doctorat : Chimie informatique et théorique : Strasbourg 1 : 2008. / Titre provenant de l'écran-titre. Notes bibliogr.

published_or_final_version / Physiology / Master / Master of Philosophy

This dissertation explores the use of photoelectron imaging spectrometry to probe the molecular electronic structure of various chemical systems, with an emphasis on photoelectron angular distributions. Experimental ion generation, mass selection, laser photodetachment, and photoelectron ion imaging were all done in a photoelectron imaging spectrometer described in detail. Results from simplistic systems, OH- and CH-, are used to illustrate the general and fundamental capabilities of imaging spectroscopy and angular distributions. This illustration is then expanded when both qualitative and quantitative analyses of photoelectron angular distributions are used to aid in the understanding of the electronic structure of several heterocyclic aromatic systems. First a qualitative analysis aids in the exploration of the electronic structure of thiophenide, C₄H₃S⁻, and furanide, C₄H₃O⁻. Ground and excited C₄H₃S and C₄H₃O radical states are observed, and bond dissociation energies are defined. Next, a new model used to qualitatively analyze photoelectron angular distributions resulting from mixed s - p hybrid states is presented and applied to detachment from pyridinide, C₅H₄N⁻; as a benchmark system. Before further exploring this model, the synthesis of several deuterated heterocyclic compounds is presented in order to determine the experimentally produced systems in our experimental setup. The electronic structure of the resultant molecules oxazolide, C₃H₂NO⁻, and thiazolide, C₃H₂NS⁻; are then investigated. Using this new qualitative model, the mixed s - p states model, to evaluate the angular distributions of the systems, the hybridization of the anion molecular orbitals is probed. Comparison of the photoelectron angular distributions that are modeled for each heterocyclic aromatic system yields several trends relating aromatic stabilization, molecular hybridization, and bond dissociation energies. A new qualitative model is then presented to evaluate photoelectron angular distributions resulting from mixed p - d states and applied to detachment from NO⁻. Finally, new ideas and directions are proposed.

No description available.

The research provides data of pH and conductivity, some anions (e. g. fluoride, chloride, bromide, nitrate, phosphate and sulphate), monovalent cations (e. g sodium, ammonium and potassium), divalent cations (e. g calcium and magnesium) heavy metals (e. g. iron, copper, zinc, nickel, cobalt, cadmium and manganese) and organic compounds – from water samples of rivers of Brunei Darussalam, namely, Brunei River, Belait River, Tutong River and Temburong River. The higher values of certain parameters with respect to the acceptable standard limits for river water indicate the pollution in river water samples of the study area, make the waters unsuitable for various applications and do pose a human health hazard. The pH levels in Brunei Darussalam is quite reassuring and mostly safe. Although there are some stretches of rivers that show slightly lower levels of pH, there is no cause for any alarm as these waterways are not sources of drinking water. As for anions and cations, the only anion of significant levels detected in Brunei Rivers is chloride whereas only monovalent cation detected in significant levels, is sodium. The concentrations of chloride and sodium ions are below the standard concentrations. Brunei Rivers are still free from chloride and sodium pollution. For heavy metals, only iron is detected in Brunei Rivers. Brunei being a oil based country experiments were done to identify levels of a numbers of significant toxic organic compounds, including, toluene and benzene which have been detected in the waters of the oil mining district of Belait District but are within normal limits. The use of a photolytic cell system to achieve the photodegradation of benzene, toluene, ethylenediaminetetra-acetic acid (EDTA) and the surfactant – hexadecyltrimethyl-ammonium bromide (C19H42NBr) is reported. The system has been optimised by investigating the effects of the addition of hydrogen peroxide (H202) as an oxidant and the addition of titanium dioxide (TiO2) as a catalyst. The results show that the photolytic system can be used to achieve >99% degradation of organic contaminants. The research also includes a final chapter on management system which covers water protection, pollution control and solid waste management in Brunei. In addition to investigating various factors of the solid waste management in Brunei, the researcher has also exposed some of the weaknesses that need immediate addressing. Various measures have been suggested to make Brunei's water more efficient. Moreover, ways of preserving the high quality of Brunei's water figures in this chapter.

Thesis (Ph.D.) -- McMaster University, 1998. / Includes bibliographical references (leaves 281-296). Also available via World Wide Web.

Thesis (Ph. D.)--University of Adelaide, Dept. of Chemistry, 2002. / Appendix inside back cover. "June 2002." Includes bibliographical references (leaves 157-168).

Thesis (M.S.)--University of Texas at El Paso, 2008. / Title from title screen. Vita. CD-ROM. Includes bibliographical references. Also available online.

Thesis (Ph. D.)--University of Missouri--Columbia, 1998. / "December 1998" Typescript. Vita. Includes bibliographical references (l. 152-155). Also available on the Internet.