Thesis (PhDMiningEngineering)--University of South Australia, 2001.

Bibliography: leaves 279-293. / xxxiv, 323 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Temperature-programmed Pyrolysis experiments employing Bowmans and Lochiel low-rank coal and treated Bowmans coals, were conducted to investigate the sulphur transformations during pyrolysis. / Thesis (Ph.D.)--University of Adelaide, Dept. of Chemical Engineering, 2000

The unique properties of diamond make it an excellent material for electronic and optical applications. It is particularly attractive for ultraviolet radiation dosimetry due to its intrinsic properties, which include biological tissue equivalence and visible blindness. Importantly, the advent of synthetic diamond, especially Chemical Vapour Deposition (CVD) diamond, has made it more economically viable for such applications. A thorough understanding of the electronic properties of diamond is needed before these applications can be fully explored. Consequently, this thesis investigates charge carrier trapping states in CVD polycrystalline diamond for the optimization of ultraviolet radiation dosimetry. / The technique of Thermally Stimulated Conductivity (TSC) is used to probe electrically active defects and is also applied for dosimetric read-out. A range of as-grown CVD polycrystalline diamond films are studied to determine attributes that favour dosimetric-related TSC. In doing so, we establish that dosimetric TSC in these films originate from defects at the grain boundaries with a correlation to high crystalline quality. / With this finding in hand, we then investigate the possibility of optimising diamond for dosimetry by controllably introducing extrinsic dosimetric defects using ion implantation. However, it is shown that these defects are not suitable for dosimetry and have a detrimental effect on the indigenous TSC signal. This study verifies the importance of crystalline quality on the indigenous dosimetric properties of CVD polycrystalline diamond. / The possibility of doping CVD diamond during growth is also investigated as a means for intentionally introducing extrinsic dosimetric defects. Sulphur is selected as the dopant based on the theoretical energy levels formed by this defect, and because the prospect of S doping in diamond remains an actively debated issue in the literature. We report for the first time defect levels extracted from TSC analysis of S-doped CVD diamond and find consistency with theoretical predications. In addition, the dominant TSC trap level in S-doped diamond shows promise for radiation dosimetry with certain properties exceeding many current radiation dosimeters. / The experimental results in this thesis lead to a deeper understanding of defect and trapping mechanisms in CVD polycrystalline diamond and establish attributes that favour TSC and related dosimetric properties in such films. This knowledge is fundamental to the realisation of diamond for ultraviolet dosimetry.

Australia has the largest economical lignite resources in the world. However, the utilisation of lignite is faced with a number of technical, economical and environmental problems due to its high moisture content and some of the deposits containing high sulphur and high inorganic matter. During pyrolysis, the first step of any thermochemical conversion processes of coal, some of the sulphur in lignite evolves as sulphur-bearing volatiles while others are retained in the solid phase of the lignite char. The present research aims to study the sulphur transformation during pyrolysis of Australian lignite. The specific objectives of this research include a study on the transformation of pyrite, sulphate and organic sulphur during lignite pyrolysis as well as an investigation of the effect of inorganic matter on the sulphur transformation during lignite pyrolysis. To help the interpretation of sulphur transformation, the lignite samples were characterised using a combination of analytical techniques, i.e. X-ray diffraction (XRD), X-ray fluorescent (XRF), ion chromatography (IC), Scanning electron microscope equipped with an energy-dispersive X-ray spectroscopy (SEM-EDS), Fourier transform infra red (FTIR), solid state 13C nuclear magnetic resonance (NMR) and petrographic analysis. Pyrolysis was carried out in a thermogravimetric analyser (TGA) and fixed bed reactor. The lignites and their chars were analysed for sulphur forms using a carbon sulphur (CS) analyser. To study the volatiles released during pyrolysis, experiments were also performed using a TGA coupled to a mass spectrometer (TGA-MS). Eleven (11) Australian lignite samples, denoted as L1 to L11, respectively, from the same lignite deposit but with different sulphur and inorganic matter concentrations were employed in this study. They are categorised as of low quality since they contain high Executive Summary Sulphur Transformation during Pyrolysis of an Australian Lignite v moisture, very high ash, low fixed carbon and thus they have low calorific value, except for L1. The lignites contain considerable amount of total sulphur, except for L1. Mineralogy of the lignites showed that the lignites contain extremely high sodium and chlorine. FTIR and solid state 13C NMR spectroscopy confirmed that oxygenated functional structures are significantly present in the lignites.

Historically, the New Zealand rationale behind air quality management has been to adopt an effects-based approach based on environmental impacts. Generally, this method has been efficient in that it permitted emitters to decide how to minimise and mitigate impacts. However, to address the inconsistencies in air quality management across New Zealand born of this approach, and to permit measures designed to improve the working of the Resource Management Act (RMA), National Environmental Standards for Ambient Air Quality have been developed and implemented to establish consistent regulation and protection for all New Zealanders. The standards were gazetted in September 2004, for full implementation by 2013. This thesis explores the implementation of the National Environmental Standards for Ambient Air Quality, examining the philosophy behind the standards and associated strategies for dealing with air pollution management in New Zealand, and the international context for the development of appropriate tools to address air quality concerns. The research also provides an independent dispersion modelling assessment of the application of the Ministry for the Environment's initiative regarding sulphur dioxide in the Marsden Point airshed, Northland, utilising The Air Pollution Model (TAPM) for a period when heightened concentration values had been recorded. The key outcomes of the thesis are: (i) 99.9th percentile and maximum values for the simulated two-day modelling case study are within those stipulated by the air quality standards for sulphur dioxide; (ii) modelled concentrations associated with shipping within the airshed of interest contribute significantly to total modelled values; (iii) the chief obstruction to increased use of the prognostic modelling approach is that of the unsatisfactory availability and integrity of emission inventories; (iv) performing long-term high-resolution simulations with multiple point sources is prohibitive due to computational demands; (v) good quality monitoring will always be required; (vi) the standards have broad and far-reaching implications for resource managers, resource users and possibly the economy of individual regions and the country as a whole; (vii) the successful implementation of the National Environmental Standards for Ambient Air Quality in New Zealand will integrate a thorough understanding of modelling, measurements, meteorology and emissions.

Bibliography: leaves 279-293. Temperature-programmed Pyrolysis experiments employing Bowmans and Lochiel low-rank coal and treated Bowmans coals, were conducted to investigate the sulphur transformations during pyrolysis.

This thesis describes the synthesis of a range of novel dithiadiazolyl radicals. The structures of these compounds are discussed. The physical properties of several compounds have been investigated using EPR spectroscopy and magnetic susceptibility studies. Chapter one begins with an overview of the chemistry of 1,2,3,5-dithiadiazolyl radicals. A general discussion of the history of organic conductors and magnets, and the terms involved in some of the techniques used is given in order to provide a background to the work presented. The second chapter outlines the synthesis and general characterisation of all the dithiadiazolyl radicals discussed in this thesis. A proposed mechanism for the conversion of parent nitriles into dithiadiazolyl radicals has been included. The third chapter describes the solid state structures of three dichlorophenyl dithiadiazolyl derivatives (2,4-, 2,5- and 3,5-dichlorophenyl-l,2,3,5-dithiadiazolyl). A further polymorph of 3,5-dichlorophenyl-1,2,3,5-dithiadiazolyl has also been included. The magnetic susceptibility of 2,4- and 3,5-dichlorophenyl-1,2,3,5-dithiadiazolyl has been investigated and the EPR analysis of all three compounds has been performed. These compounds are the first examples of neutral dithiadiazolyl radicals that form evenly spaced, segregated stacks in the solid state. Chapter four describes the dimer stacking structures of two further dichlorophenyl dithiadiazolyl derivatives (2,3- and 3,4-dichlorophenyl-1,2,3,5-dithiadiazolyl). The fifth chapter discusses the association of 3,5-dibromphenyl-1,2,3,5-dithiadiazolyl in the solid state. An investigation of this compound by EPR spectroscopy is also presented. Chapter six describes the trans cofacial association of p-iodophenyl-1,2,3,5-dithiadiazolyl in the solid state, only the second published example of this mode of dimerisation. The synthesis of o- and p-iodobenzonitrile are also described. An investigation of the EPR signal of this compound has also been included. Chapter seven describes the specialised techniques used in the synthesis of all the compounds. A list of the instruments used for analysis is also included.

No description available.

<p> Adducts of aluminum chloride and aluminum bromide with tetrasulphur tetranitride have been prepared and characterized. The reaction of trimethylaluminum and triethylaluminum with tetrasulphur tetranitride has been studied. The reaction of sulphur with α-methylbenzylamine has been investigated, and the reaction mechanism proposed by Sasaki for benzylamine reacting with sulphur has been found to be consistent with the data, provided certain limitations are imposed. </p> / Thesis / Master of Science (MSc)

<p> The methylation of three isomeric hexasulphur diimides under basic conditions has been investigated. Both mono- and dimethylated products have been obtained from the 1, 5- and 1,4-hexasulphur diimides. The anion formed from the 1,3 isomer was found to undergo decomposition, the major products being polysulphides and N-methyl heptasulphur imide. The usefulness of proton NMR, mass spectra, and infrared spectra in conjunction with these compounds has been considered.</p> / Thesis / Master of Science (MSc)