<p> The involvement of d orbitals in the coordination of sulphur in three simple sulphur compounds ls Investigated using an ab initio approach. Comparison of minimal and extended basis set results for molecular properties such as dipole moment, molecular geometry, and force constants provides a means of establishing the importance of d orbitals In sulphur compounds and probably other second row compounds. Excited states of sulphur dioxide and ozone are studied in the hope of elucidating the respective spectra on a theoretical basis. These investigations also provide initial data for the parametrization of the semi-empirical CNDO approach for second row atoms. </p> / Thesis / Master of Science (MSc)

<p> International Nickel Company's 1250 ft. stack located in Sudbury, Ontario emits an estimated 3,000 tons of sulphur oxide daily. The purpose of this study is to investigate the use of stable sulphur isotopes as a means of tracing the movement of these sulphur oxide emissions. Sulphur isotope analysis were done for lakewater, rainwater and sediment samples taken from the Sudbury-Timagami district and also for particulate and gas samples taken from the 600 ft. level of the International Nickel Company's 1250 ft. stack. </p> <p> The s s^34 values of lake surface samples showed a decrease related directly to the increase of the logarithm of the distance from Sudbury. The maximum s s^34 value for the lakewater samples was + 8.49 p.p.t. at a distance of 7 miles from Sudbury. The minimum s s^34 value for lakewater samples was+2.97 p.p.t. at a distance of 55 miles from Sudbury. </p> <p> The rainwater s s^34 values vary from + 4.85 p.p.t. recorded for a station 5 miles north of Sudbury to + 2.07 p.p.t. for a station 60 miles east north east of Sudbury. </p> <p> The increase in s s^34 values in the lakewater relative to rainwater strongly suggest that the oxidation of so2(g) to s4^2- is occurring in the lakes in the Sudbury-Timagami district. </p> / Thesis / Bachelor of Arts (BA)

<p> The preparation of compounds containing polyatomic cations of sulphur, selenium and tellurium has been investigated by using oxidising agents such as AsF5, SbF5, S2O6F2 and SO3. New compounds, containing polyatomic cations Se8 2+, Se4 2+, Te3n n+, Te4 2+ Ten n+, S16 2+, S8 2+ and S4 2+, and anions of very strong acids such as Sb2F11- and AsF6- were isolated and characterised by a combination of the stoichiometry of the preparation reactions, UV-visible spectrophotometry, Infrared and Raman spectroscopy and magnetic susceptibility measurements.</p> <p> Solutions of sulphur in various concentrations of oleum were investigated in detail by UV-visible spectrophotometry and e.s.r. spectroscopy. Evidence is presented for the formation of the sulphur cations S16 2+, S8 2+ and S4 2+ in these media, and for the presence of low concentrations of the radical cations S8+ and S4+.</p> / Thesis / Doctor of Philosophy (PhD)

The sulfonation of bromobenzene with sulfur trioxide in liquid sulfur dioxide at -12 to -13° C. was studied to determine its relative reactivity. The relative rate constant ratio, kbenzene/kbromobenzene, was found to be 28.6 in a competitive reaction between benzene and bromobenzene. The isomer distribution was found to be 0.15 ± 0.02% for the meta, 0.91 ± 0.04% for the ortho and 98.93 ± 0.14% for the para isomers. The partial rate factors were calculated to be pf= 0.208, of= 0.0096 and mf = 0.00018. The relative rate data exhibited a distinctive behaviour previously noted in related systems, possibly due to secondary reactions. Data, generated artiticially, which showed similar behaviour, indicate that possibly the primary and secondary reactions both produce the final products in competition with each other at significantly different selectivities.

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Earth and Planetary Science, 1982. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND LINDGREN / Bibliography: leaves 38-42. / by Jeffrey Thomas Goodwin. / M.S.

This item was digitized as part of the Million Books Project led by Carnegie Mellon University and supported by grants from the National Science Foundation (NSF). Cornell University coordinated the participation of land-grant and agricultural libraries in providing historical agricultural information for the digitization project; the University of Arizona Libraries, the College of Agriculture and Life Sciences, and the Office of Arid Lands Studies collaborated in the selection and provision of material for the digitization project.

The technical feasibility of producing sulphur-impregnated activated carbons (SIACs) from high-sulphur fluid coke by chemical activation was investigated. Using KOH and SO2, the activation process was able to produce SIACs with controllable specific surface area (SBET), pore size distribution and sulphur content. The highest SBET was over 2500 m2/g and the highest sulphur content was 8.1 wt%. K-edge X-ray Absorption Near Edge Structure (XANES) spectroscopy was employed to characterize the sulphur in fluid cokes and SIACs. The results revealed that the sulphur on fluid coke surface was mainly in the form of organic sulphide and thiophene (total 91-95 %), in addition to some sulphate (5 - 9%). The study of KOH-treated fluid coke suggested that KOH was effective in converting organic sulphide and thiophene to water soluble inorganic species which were readily removed by acid and water washing. SO2 treatment of fluid coke added sulphur to fluid coke through SO2-carbon reaction. Elemental sulphur was the main product, while part of the thiophene, sulphide and sulphate in the raw coke remained in the product. In KOH-SO2 activation, disulphide, sulphide, sulphonate and sulphate were identified on SIAC surface; no thiophene was found, suggesting a complete removal of thiophene. Sulphur content in specific forms in SIACs was therefore controllable by varying the ratio of KOH, SO2 and fluid coke. SIACs produced from KOH-SO2 activation showed a comparable Hg2+ adsorption capacity (43 – 72 mg/g) with those reported in the literature (35-100 mg/g) and that of a commercial SIAC (41 mg/g). Although a larger SBET often resulted in a greater Hg2+ adsorption capacity, the benefit started to diminish when SBET was greater than about 1000 m2/g. A statistically significant and positive correlation was found between Hg2+ adsorption capacity and total sulphur content. Elemental sulphur and reduced sulphur were largely responsible for the enhanced Hg2+ adsorption.

The technical feasibility of producing sulphur-impregnated activated carbons (SIACs) from high-sulphur fluid coke by chemical activation was investigated. Using KOH and SO2, the activation process was able to produce SIACs with controllable specific surface area (SBET), pore size distribution and sulphur content. The highest SBET was over 2500 m2/g and the highest sulphur content was 8.1 wt%. K-edge X-ray Absorption Near Edge Structure (XANES) spectroscopy was employed to characterize the sulphur in fluid cokes and SIACs. The results revealed that the sulphur on fluid coke surface was mainly in the form of organic sulphide and thiophene (total 91-95 %), in addition to some sulphate (5 - 9%). The study of KOH-treated fluid coke suggested that KOH was effective in converting organic sulphide and thiophene to water soluble inorganic species which were readily removed by acid and water washing. SO2 treatment of fluid coke added sulphur to fluid coke through SO2-carbon reaction. Elemental sulphur was the main product, while part of the thiophene, sulphide and sulphate in the raw coke remained in the product. In KOH-SO2 activation, disulphide, sulphide, sulphonate and sulphate were identified on SIAC surface; no thiophene was found, suggesting a complete removal of thiophene. Sulphur content in specific forms in SIACs was therefore controllable by varying the ratio of KOH, SO2 and fluid coke. SIACs produced from KOH-SO2 activation showed a comparable Hg2+ adsorption capacity (43 – 72 mg/g) with those reported in the literature (35-100 mg/g) and that of a commercial SIAC (41 mg/g). Although a larger SBET often resulted in a greater Hg2+ adsorption capacity, the benefit started to diminish when SBET was greater than about 1000 m2/g. A statistically significant and positive correlation was found between Hg2+ adsorption capacity and total sulphur content. Elemental sulphur and reduced sulphur were largely responsible for the enhanced Hg2+ adsorption.

Thesis (M.S.)--Texas A&M University, 2003 / "August 2003." Includes bibliographical references (p. 70-82). Also available via the Internet.

Bird populations are changing at unprecedented rates in response to human-induced changes to the global environment, and these rates of change are expected to accelerate over the coming decades. Changes in the levels of sulphur dioxide (SO2) in the atmosphere through emissions from power stations pose a potential threat to bird populations. However, avian response to SO2 pollution is poorly understood. Exploring the relationship between avian diversity and SO2 exposure levels will help in determining species sensitive to air pollution. This study seeks to understand the interactions between avian diversity and SO2 concentration levels around Matimba power station so as to have more insight on the level of avian vulnerability to air pollution. Matimba is an important site in South Africa as a second coal fired power station, Medupi, is currently being constructed with additional stations also a possibility. This study represents an important baseline assessment of the avian population status before the additional pollution burden is realised from Medupi. Ten min repeated point counts were conducted at three sample sites with varying distances from Matimba and Medupi power stations. These counts were used to calculate bird species density and diversity. Cloud-free Landsat 8 imagery acquired on 7 January, 2014 was used to derive habitat structure and productivity variables. Elevation variables were derived using a DEM (Digital Elevation Model) obtained from NASA Global Data Explorer. The AERMOD dispersion model was used to characterise spatio-temporal variations in ambient SO2 concentrations around Matimba power station. Multiple regression analysis was then used to ascertain which of these variables (SO2, habitat structure, productivity and terrain) contribute most to the observed variation in bird species density and diversity around Matimba and Medupi power stations. SO2 polluted air did not have an influence on bird species density and diversity at the community level. At species level two species (Batis molitor and Streptopelia senegalensis) exhibited some measure of negative response to SO2 air pollution. However, after further investigation using multiple regression analysis it was revealed that habitat structure had more influence on the density of these two species compared with ambient SO2 concentrations. Bird species density and diversity varied significantly among the sample sites but were not related to the distance to the source of the SO2 air pollution. Evidence obtained from this study revealed that continuous monitoring of the interactions between SO2 polluted air and bird populations is recommended for a more comprehensive understanding of avian susceptibility towards SO2 air pollution and this will also facilitate in the selection of sensitive and relevant species for future ecology studies at other coal-fired power stations. Furthermore, it is expected that SO2 concentrations will significantly increase with the commissioning of Medupi power station thus further necessitating the need for continuous monitoring of bird species densities around Matimba and Medupi power stations. / MSc (Geography and Environmental Management), North-West University, Potchefstroom Campus, 2015