A thesis Submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, for the Degree of Master of Science. Johannesburg, December 1992. / The ethanol conversion to hydrocarbons over acidic catalysts proceeds with high activity and selectivity and has hence generated considerable interest. In this thesis an investigation of the use of a range of supports, loaded with metals as potential catalysts for the ethanol transformation reaction, is reported. In particular, Ti02 was investigated as a support and the addition of a secondary component to the catalyst was examined with respect to product selectivities. [Abbreviated Abstract. Open document to view full version] / AC2017

A thesis submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Doctor of Philosophy. Johannesburg / In this thesis we investigate the evolution of viscous FRW cosmological models for two different constitutive equations for the bulk viscous pressure a, namely (Abbreviation abstract) / Andrew Chakane 2018

A thesis submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Doctor of Philosophy. Johannesburg, / In this thesis we investigate the evolution of viscous FRW cosmological models for two different constitutive equations for the bulk viscous pressure a, namely: The truncated theory,,,,,,,,,,,,,,,, and the full (non-truncated] Israel-Stewart theory ...................We first review the relativistic theory of non-equilibrium thermodynamics developed by Eckart (1940) and the essentially equivalent formulation of the theory given by Landau and Lifshitz (1958). We give a, brief description of the relativistic second-order theories found by Israel and Stewart (1976) and subsequently developed by Pavon, Jou, and co-workers (1982, 1993). All this is done in order to develop the tools for the study of the evolution of FRW cosmological models in the context of causal thermodynamics. We find new exact and perturbative solutions of Einstein's field equations for the truncated Israel-Stewart theory of irreversible thermodynamics. We show that viscous effects speed up the expansion of the universe. We also consider a viscous fluid in the presence of a " non-interacting scalar field and show that inflationary solutions exist. The full theory of bulk viscosity is applied to dissipative FRW spacetimes. New causal viscous inflationary solutions are presented. These solutions extend the results obtained by Maartens (1995a) to cases where the coefficient of bulk viscosity e and the relaxation time r are independent. Power-law solutions for the scale factor are shown to exist. / Andrew Chakane 2018

Orientador: Ricardo Alan Verdú Ramos / Coorientador: Emanuel RochaWoiski / Banca: João Batista Aparecido / Banca: Paulo Hélio Kanayama / Resumo: O presente trabalho teve como objetivo o desenvolvimento e teste de um protótipo de um programa computacional para simulação de plantas térmica e de potência, com os principais recursos de programas comerciais existentes, com baixo custo e com interface gráfica mais amigável. O referido programa foi denominado TPPS (abreviação de Thermal Power Plant Software), tendo sido desenvolvido na linguagem object pascal, utilizando a IDE do DELPHI e a biblioteca FLUIDPROP, na qual constam os componentes para cálculo das propriedades termodinâmicas envolvidas. Para tanto, inicialmente é apresentada uma breve descrição de alguns programas computacionais disponíveis no mercado que comumente são utilizados no meio acadêmico sendo que, dentre eles, foram escolhidos três (Cycle-Tempo, EES e IPSEpro) para efeito comparativo dos resultados das simulações com o programa desenvolvido, tendo como base duas plantas básicas, uma de geração e outra de cogeração de energia. Foi utilizada uma metodologia de simulação que consiste na avaliação dos processos, dos dados e do resultado dos cálculos obtidos. Para tanto, foram consideradas as hipóteses de regime permanente; variações das energias cinéticas e potencial são desprezadas em virtude de se desejar apenas um simples comparativo de valores das propriedades termodinâmicas calculadas; processos adiabáticos em todos os equipamentos que fazem parte dos ciclos, exceto para trocadores de calor, para os quais um parâmetro de eficiência define a quantidade de calor transferida ao meio. Os resultados obtidos foram bastante satisfatórios, tendo em vista que não houve discrepâncias entre os resultados obtidos por cada um dos programas, mostrando que a ferramenta desenvolvida, em sua primeira versão, atende os requisitos a que se propôs. Por fim, são apresentados resultados de uma simulação de uma planta de cogeração mais complexa, através do TPPS / Abstract: This study aimed to develop and test a prototype of a computer program for simulation of thermal and power plants, with the main sources of existing commercial programs, with low cost and friendlier graphical interface. The program was denominated TPPS (abbreviation for Thermal Power Plant Software), and has been developed in Object Pascal language, using the Delphi IDE and FLUIDPROP library, which contains the components for calculating the thermodynamic properties involved. Therefore, initially presents a brief description of some computational programs available that are commonly utilized in the academic environment and among them, three were chosen (Cycle-Time, EES and IPSEpro) for comparison of the simulation results with the program developed, based on two basic plants, one of power generation and the other one of cogeneration. The simulation methodology consists of the evaluation of the processes, data and results obtained from the calculations. Therefore, it was considered the hypothesis of steady state and the variations of kinetic and potential energies were neglected because just a simple comparison of calculated values of thermodynamic properties; adiabatic processes in all devices of the cycles, except for heat exchangers, for which an efficiency parameter defines the amount of heat transferred to the environment. The results were quite satisfactory, considering that there were no discrepancies between the results obtained by each one of the programs, showing that the first version of the software developed meets the proposed requirements. Finally, results of simulation of a more complex cogeneration plant through the TPPS are presented / Mestre

Orientador: Celso Eduardo Tuna / Coorientador: José Alexandre Matelli / Banca: Pedro Magalhães Sobrinho / Banca: Diovana Aparecida dos Santos Napoleão / Resumo: As indústrias queimam combustíveis para produzir energia térmica para um processo. Em alguns casos, uma fração dessa energia não é completamente utilizada. Com o intuito melhorar a eficiência do sistema, essa fração de energia térmica não utilizada pode ser usada para acionar um Sistema de Refrigeração por Absorção (SRA). Nas últimas décadas, o interesse em usar SRA aumentou consideravelmente por conta da possibilidade de se utilizar vapor, água quente e gases de exaustão de sistemas de potência. Além disso, melhorias tecnológicas permitiram uma melhor eficiência do SRA. Uma modelagem termodinâmica do SRA foi realizada para analisar o desempenho de uma máquina em termos energéticos e exergéticos para obter água gelada a 5, 7, 9, 11 e 15 oC com uma fonte de água quente a 80, 90, 100, 110, 120 e 130 oC . A primeira e segunda lei da termodinâmica, tabelas e equações das propriedades da solução aquosa de brometo de lítio e água foram utilizadas para modelar o ciclo e efetuar os cálculos. As hipóteses básicas consideradas foram regime permanente, água pura, bomba isentrópica e processos adiabáticos. Através da análise dos resultados, que essa metodologia pode ser aplicada para determinar o comportamento da variação do COP e eficiência exergética em função da temperatura da água quente que alimenta o gerador e da água gelada obtida no evaporador. Realizou-se análise energética e exergética em cada componente do sistema. Com base nesses dados, pode-se verificar que a faixa de temper... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Industries burn fuels to produce thermal energy for a process. In some cases, a fraction of this energy is not fully utilized. In order to improve the efficiency of the system, this waste of energy can be used to drive an Absorption Refrigeration System (ARS). On the last decades, the interest in using ARS increased considerably because of the possibility of using steam, hot water or exhaust gases from thermal engines. Furthermore, technological improvements increased efficiency of this cycle. A thermodynamic model of an ARS was developed to calculate the required energy to generate cold water at 5, 7, 9, 11 e 15 oC from a heat source at 80, 90, 100, 110, 120, 130 oC. First law of thermodynamic, tables and equations of property of aqueous solution of lithium bromide and water were used to model the cycle. The basic hypothesis considered was steady state, pure water, isentropic pump and adiabatic processes. Analysis of the results revealed that this methodology can be applied to study the relationship between COP and exergetic efficiency as a function of the inlet hot water temperature and outlet cold water . Energetic and exergetic analysis were performed for each component. The results show that the highest COP and exergetic efficiency were obtained for hotwater temperature range between 90 to 100 oC. The distribution in terms of exergy in main components were studied and revealed that the high losses of exergy occurred in evaporator and absorber / Mestre

by Lee Siu-keung. / Parallel title in Chinese. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1992. / Includes bibliographical references (leaves 162-164). / Chapter Chapter 1 --- Introduction --- p.5 / Chapter Chapter 2 --- Path Integrals / Chapter 2.1 --- Path´ؤIntegral Approach to Quantum Mechanics --- p.8 / Chapter 2.2 --- Path´ؤIntegral Approach to Statistical Mechanics --- p.14 / Chapter 2.3 --- Variational Principle --- p.18 / Chapter 2.4 --- "Variational Method Proposed by Giachetti and Tognetti, and by Feynman and Kleinert" / Chapter 2.4.1 --- Effective Classical Partition Function --- p.24 / Chapter 2.4.2 --- Particle Distribution Function From Effective Classical Potential --- p.34 / Chapter Chapter 3 --- Systematic Perturbation Corrections to the Variational Approximation Proposed in Section2.4 / Chapter 3.1 --- Formalism / Chapter 3.1.1 --- Free Energy --- p.38 / Chapter 3.1.2 --- Particle Distribution Function --- p.49 / Chapter 3.2 --- Second Order Correction to Free Energy --- p.53 / Chapter 3.3 --- First Order Correction to Particle Distribution Function --- p.60 / Chapter Chapter 4 --- Examples and Results / Chapter 4.1 --- Quartic Anharmonic Oscillator / Chapter 4.1.1 --- "Free Energy, Internal Energy and Specific Heat" --- p.69 / Chapter 4.1.2 --- Particle Distribution Function --- p.87 / Chapter 4.2 --- Symmetric Double-well Potential / Chapter 4.2.1 --- "Free Energy, Internal Energy and Specific Heat" --- p.88 / Chapter 4.2.2 --- Particle Distribution Function --- p.106 / Chapter 4.3 --- Quartic-cubic Anharmonic Potential / Chapter 4.3.1 --- Free Energy --- p.108 / Chapter 4.3.2 --- Particle Distribution Function --- p.115 / Chapter Chapter 5 --- Application to the One-dimensional Ginzburg-Landau Model / Chapter 5.1 --- Introduction --- p.120 / Chapter 5.2 --- Exact Partition Function and Free Energy Per Unit Length --- p.123 / Chapter 5.3 --- Zeroth Order Approximation to Free Energy Per Unit Length --- p.126 / Chapter 5.4 --- Exact Specific Heat --- p.133 / Chapter 5.5 --- Zeroth Order Approximation to Specific Heat --- p.139 / Chapter Chapter 6 --- Conclusion --- p.141 / Chapter Appendix I --- Functional Calculus - Differentiation --- p.145 / Chapter Appendix II --- Evaluation of Feynman Propagator Δf(τ) --- p.147 / Chapter Appendix III --- Vanishing of the First Order Correction-βf1 --- p.150 / Chapter Appendix IV --- Numerical Method for the Energy Eigenvalues and Eigenfunctions of the One-dimensional Schroedinger Equation with ax2 + bx4 Potential --- p.153 / Chapter Appendix V --- Numerical Integrations with imaginary Ω --- p.158 / References --- p.162 / Figures --- p.165

Coarse-graining and multi-scale approaches are rapidly becoming important tools for computer simulations of large complex molecular systems. Such theoretical models are powerful tools because they allow one to probe the essential features of a complex, many-bodied system on length and time scales over which emergent phenomena may occur. Because of the computational advantages and fundamental insight made available through coarse-grained methods, a vast array of various phenomenological potentials to describe coarse-grained interactions have been developed; nonetheless, the ability of these potentials to provide quantitative information about several different properties of the same system is not evident. On a theoretical level, it is not well-understood how small correlations in the long-range structure propagate through the coarse-graining procedure into the effective potential and lead to incorrect thermodynamics. Taking an alternative approach, this dissertation will discuss an analytical coarse-graining method for synthetic polymer chains of specific chemical structure, where a group of atoms on a polymer chain are represented by a variable number of soft interacting effective sites. The approach is based in liquid-state theory, providing a theoretical framework to address questions of thermodynamic consistency. It will be shown that the proposed method of coarse-graining maintains thermodynamic consistency for a variety of polymer models. In a multi-scale modeling scheme simulations of the same system represented by several different levels of detail may be joined to provide a complete description of the system at all length and time scales of interest. This dissertation includes previously published and unpublished co-authored material.

Vita. / Digitized by Kansas Correctional Industries

Este trabalho consiste basicamente em dois experimentos: Determinação da equação de estado de um gás frio aprisionado, e na comparação das temperaturas de uma amostra de átomos confinadas em dois tipos de armadilhas magneto-ópticas. No primeiro experimento utilizamos a generalização do conceito de pressão e volume que foram redefinidos de maneira apropriada para alcançamos uma equação de estado. Experimentalmente nossa amostra apresentou um desvio do esperado para um gás ideal, dessa forma utilizamos uma expansão virial com as novas definições de pressão e volume para investigar as interações entre os átomos. Já no segundo experimento utilizamos uma técnica que mede transiente temporal da absorção do feixe pelos átomos através de um fotodetector para a obtenção da temperatura. Neste experimento obtemos temperaturas equivalentes para as duas armadilhas. / This work consists of two experiments: Determination of the state equation a trapped cold gas, and the comparison of the temperatures of confined atoms in two types of magneto-optical traps. For the first experiment we generalized and defined a new pressure and volume concept and we reached a state equation. Experimentally our sample presented a deviation of the ideal gas, in that way we used a virial expansion with the new pressure and volume definitions to investigate the interactions among the atoms. In the second experiment we used a technique that measures temporal variation of the absorption of a probe beam that crosses the atoms by a photodetector, witch gives us the information about the temperature. We have found equivalent temperatures for the two traps.

Cryptosporidium parvum is a deadly waterborne protozoan parasite that invades the gastrointestinal tract of humans and causes severe to life-threatening gastro enteric disease. Due to the ubiquitous nature of Cryptosporidium parvum in the world’s water, it is necessary to determine the source of an outbreak. Rapid detection and identification of various genotypes of Cryptosporidium are a valuable goal in determining the source of the pathogen in a human epidemic. Exploitation of gene sequences specific to species is a powerful tool detecting pathogens. Molecular beacons are one of these tools for high selectivity and specificity detection of DNA and RNA. Molecular beacon is a single strand of DNA that forms a stem and loop structure, where the stem holds the DNA together and the loop detects a target sequence. This molecular beacon detection is determined by the changes of fluorescent emissions of fluorescent dye linked to the ends of the stem. In this thesis work, a new and novel molecular beacon was designed to detect the specific sequences from the heat shock protein gene of Cryptosporidium parvum that infects humans. This probe is synthesized by the conjugation of pyrene molecules to both ends of the stem which leads to a unique feature of pyrene excimer-monomer switching molecular beacon upon the hybridization of the loop sequence with the target DNA sequence. This thesis systematically investigates the physical binding (e.g., quantum yield) and thermodynamic properties, including enthalpy, entropy, and free energy of this excimer-monomer switching molecular beacon in the presences of complimentary, mismatched, and damaged DNA, respectively, in the three phases: phase one is the molecular beacon in the stem and loop structure, phase two is the molecular beacon hybridized to its target DNA, and phase three is the molecular beacon in a random coil. The effect of magnesium concentration on the binding and thermodynamic properties was also investigated. Finally, as a comparison, a conventional fluorescence resonance energy transfer-based molecular beacon with a fluorophore at the 5’ end and quencher at the 3’ end was used to assess selectivity and sensitivity in detection of DNA-DNA hybridization.