This dissertation is focused on modeling charge-transport in π-conjugated organic materials, which serve as the active materials in light-weight, flexible, organic photovoltaic cells, offering the potential for cheap, ubiquitous renewable energy. In particular, we used computational chemistry to gain insight into the fundamental processes of charge transport within organic semiconductors to derive an understanding of chemical and physical phenomena that can not be explained through experiment alone in order to further the performance of organic-based electronic devices. In order to accurately model the organic materials, a combined quantum-mechanical and classical approach is needed, with the ground and excited state electronic properties of isolated organic materials determined using DFT/TD-DFT as a first step and coupled with molecular dynamics and mechanics. This allows for an understanding of the molecular order and packing within nanoscale structures as well as the impact of the intermolecular interactions. However, standard DFT methods suffer from intrinsic errors resulting from approximations to the exchange-correlation potential that can be corrected using a simple non-empirically tuning procedure. We briefly review the electronic structure methods that we use and the non-empirically procedure for DFT that allows for a substantial improvement over standard DFT methods. We then discuss the main results of this research. In Chapter 3, we detail the understanding of the limitations in DFT (currently one of our main tools) and improvements that can be achieved through non-empirically tuning a specific DFT method for the system of study. We detail the dependence of the range-separation parameter used in long-range corrected hybrid functionals on both the size and degree of conjugation for a given system. We also demonstrate the effect that self-interaction corrections employed through range-separated hybrid functionals can have in describing thermodynamic and electronic properties for large, organic π-conjugated systems. In this study, we chose a property that critically depends on the degree of delocalization (i.e., torsion potentials) to correlate the degree of delocalization with the choice of a given method in order to understand how the self-interaction errors affects this property. These results are published in C Sutton et al. “Accurate Description of Torsion Potentials in Conjugated Polymers using Density Functionals with Reduced Self-interaction Error” Journal of Chemical Physics, 140, 054310, 2014. In Chapter 4, we discuss how non-empirically tuning DFT can be used to rigorously model electron transfer in single-molecule systems (i.e., organic mixed-valence systems), where we modeled the symmetry breaking and charge (de)localization in charge-transfer complexes compared with high-level methods. The results presented in Chapter 4 are published in C Sutton et al. “Towards a Robust Quantum-Chemical Description of Organic Mixed-Valence Systems” Journal of Physical Chemistry C, 118, 3925, 2014. In Chapter 5, we applied this method to interpret photoelectron spectroscopy spectra in order to elucidate the localized nature of a charge carrier in prototypical organic semiconductors; this understanding was then extended to quantify the relaxation energy in finite molecular clusters in the presence of an excess charge from a combined multi-layer quantum-mechanical/molecular-mechanical method. In Chapter 6, we determined the effect of choosing various DFT methods on the intermolecular electronic couplings and band structure calculations in organic molecules, which are published by C Sutton et al. in "Understanding the Density Functional Dependence of DFT-Calculated Electronic Couplings in Organic Semiconductors” Journal of Physical Chemistry Letters, 4, 919, 2013. Finally, conclusions and further considerations are discussed in Chapter 7.

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The present thesis concerns catalytic conversion of syngas (H2+ CO) into a blend of methanol and higher alcohols, an attractive way of producing fuels and chemicals. This route has the potential to reduce the oil dependence in the transport sector and, with the use of biomass for the syngas generation, produce CO2-neutral fuels. Alkali promoted MoS2-based catalysts show a high selectivity to higher alcohols, while at the same time being coke resistant, sulfur tolerant and displaying high water-gas shift activity. This makes this type of catalyst especially suitable for being used with syngas derived from biomass or coal which typically has a low H2/CO-ratio. This thesis discusses various important aspects of higher alcohol synthesis using MoS2-based catalysts and is a summary of four scientific papers. The first part of the thesis gives an introduction to how syngas can be produced and converted into different fuels and chemicals. It is followed by an overview of higher alcohol synthesis and a description of MoS2-based catalysts. The topic alcohol for use in internal combustion engines ends the first part of the thesis. In the second part, the experimental part, the preparation of the MoS2-based catalysts and the characterization of them are handled. After describing the high-pressure alcohol reactor setup, the development of an on-line gas chromatographic system for higher alcohol synthesis with MoS2 catalysts is covered (Paper I). This method makes activity and selectivity studies of higher alcohol synthesis catalysts more accurate and detailed but also faster and easier. Virtually all products are very well separated and the established carbon material balance over the reactor closed well under all tested conditions. The method of trace level sulfur analysis is additionally described. Then the effect of operating conditions, space velocity and temperature on product distribution is highlighted (Paper II). It is shown that product selectivity is closely correlated with the CO conversion level and why it is difficult to combine both a high single pass conversion and high alcohol selectivity over this catalyst type. Correlations between formed products and formation pathways are additionally described and discussed. The CO2 pressure in the reactor increases as the CO conversion increases, however, CO2 influence on formation rates and product distribution is to a great extent unclear. By using a CO2-containing syngas feed the effect of CO2 was studied (Paper III). An often emphasized asset of MoS2-based catalysts is their sulfur tolerance. However, the use of sulfur-containing feed and/or catalyst potentially can lead to incorporation of unwanted organic sulfur compounds in the product. The last topic in this thesis covers the sulfur compounds produced and how their quantity is changed when the feed syngas contains H2S (Paper IV). The effect on catalyst activity and selectivity in the presence of H2S in the feed is also covered. / <p>QC 20150115</p>

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Thesis (PhD)--Macquarie University, Division of Humanities, Department of English, 2004. / Bibliography: leaves 270-277. / Introduction -- George MacDonald's religious heritage -- George MacDonald's philosophical and literary roots -- Of friends and teachers -- Conversion studies and critical application -- Children on the path -- Waking from slumber -- Courageous stances -- Toppled pride -- Broken vessels -- Implications of MacDonald's conversion depictions. / Victorian author George MacDonald is best remembered for his writing in the genres of fairy tale and fantasy. MacDonald was, however, most popular during his own time as a writer of realistic adult fiction. He was widely read but critically dismissed as a writer whose works were both didactic and predictable in plot. MacDonald was primarily a teacher who used the novel as a means to convey to readers his Christian message of hope and transformation. -- This thesis begins with a study of those individuals and ideas that influenced MacDonald's thoughts and beliefs. The second part of this thesis is an overview of studies of spiritual conversion, with particular emphasis on the works of V. Bailey Gillespie, Lewis Rambo, John Lofland, and Norman Skonovd. Their works in the field of conversion studies include several schemata which are helpful in explaining specific depictions of conversion within MacDonald's adult fiction. -- The remainder of the thesis focuses on MacDonald's portrayals of characters who experience conversion in his novels. They are placed into the following categories: Children on the Path; Waking from Slumber; Courageous Stances; Toppled Pride; and Broken Vessels. The experiences of the characters are thoroughly examined and justification is offered for their inclusions in their respective categories. -- This study counters the criticism levelled at MacDonald during his own time that he was caught in repetitive plots for lack of skill or inspiration. My findings suggest that MacDonald's depictions show a deep as well as wide understanding of the process of conversion, an understanding which seems to have encompassed a broader understanding than those of most of the religious writers of his own day. I suggest that his focus was on his message rather than his art. Therefore, his adult realistic fiction constitutes a very substantial literary achievement and offers contemporary readers and writers a benchmark against which to measure both their own understandings of conversion and their own expressions of it. / Mode of access: World Wide Web. / 277 leaves

Thesis (D. Min.)--Bethel Theological Seminary, 1988. / Bibliography: leaves 201-204.

Thesis (Ph. D. - Hydrology and Water Resources)--University of Arizona. / Includes bibliographical references.

Thesis (M.S. - Mechanical Engineering)--University of Arizona. / Includes bibliographical references.

Thesis (MSc)--University of Stellenbosch, 2007. / Bibliography. Also available via the Internet.