A thesis submitted to the Faculty of Engineering, University of the Witwatersrand, Johannesburg, South Africa in fulfilment of the requirements for the degree of Doctor of Philosophy. / The aim of process synthesis is to select process equipment and interconnections in order to achieve some performance goal, such as the composition of one or more products, in an optimal manner. This work focuses on the synthesis and optimization of vapour-liquid equilibrium (VLE) separation processes. The regions of feasible products for a range of VLE separation processes (including simple distillation, simple condensation and processes comprised of one or two flash stages and mixing) are determined and analyzed. Binary and ternary systems, both ideal and non-ideal, are considered. It is shows .at the products of VLE separation processes are not inherently restricted; limitations in product composition are therefore introduced by the choice of separation equipment. The products on the boundary of the region of feasible products are often found to be associated with infinite costs. Therefore costs and, product composition should he considered simultaneously in process synthesis. This work introduces a pair of variables which are proposed as cost indicators for VLE separation processes. These variables, which are called "capacity variables", pertain to distillation columns and a wide range of other VLE separation processes, allowing their comparison. The variables incorporate both capital and energy costs of a process and are thus related to total annual costs. They accommodate costs of both boiling and condensing. They ate simple to calculate from the mass balance equations. The capacity variables are analogous to mean residence time, which serves as a cost indicator for processes invoi ving reaction. The capacity variables are evaluated for a range of processes separatins binary and ternary mixtures and a range of thermodynamic systems. The capacity variables reflect the impact of the operating parameters, such as product specifications and reflux ratio, on process costs. In distillation processes, the optimum reflux ratio is found to be close to the beuristic value of 1.2 times the minimum reflux ratio. The capacity variables are proposed as useful tools for the initial stages of process synthesis. / Andrew Chakane 2018

Este trabalho apresenta um extenso estudo experimental das características elétricas de um laser de Cu-HBr com o objetivo de determinar as condições de operação que permitem obter máxima potência média e eficiência do laser. Medidas das formas de onda da tensão e corrente de descarga foram realizadas para vários parâmetros importantes de operação do laser: freqüência de repetição de pulsos, tensão de carga, circuito elétrico de excitação e diferentes misturas de gases (Neônio puro, Neônio/HBr e Ne/HBr/Cu). Comparando as medidas para diferentes misturas de gases, foi possível identificar a influência da composição do gás em importantes parâmetros de descarga, tais como: tensão de ruptura, tensão de sustentação, corrente máxima e densidade residual de elétrons. Os resultados experimentais obtidos indicam que a máxima eficiência de conversão do laser ocorre para um campo elétrico efetivo de descarga muito bem definido. Este campo elétrico, por sua vez, depende da densidade residual de elétrons que assume um intervalo no qual o laser opera nas condições ótimas de potência média e eficiência. Foi determinado a maneira pela qual os diferentes parâmetros do laser influenciam esta densidadade residual de elétrons, e foi mostrado que é possível operar o laser com a máxima eficiência em diferentes condições de operação. Embora nestas condições ótimas a energia do pulso de laser permaneça constante, demonstrou-se que a largura do pulso e a potência instantânea máxima do laser variam de forma acentuada. Assim, os resultados deste trabalho mostram que é possível controlar muito bem as características da radiação emitida pelo laser mantendo a eficiência de conversão de energia.

by Chung Pui Shan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references (leaves 105-110). / Abstracts in English and Chinese. / Abstract --- p.i / Acknowledgements --- p.iii / Table of contents --- p.v / Chapter Chapter 1. --- Introduction --- p.1 / Chapter 1.1 --- Metal clusters embedded in fused silica glass --- p.2 / Chapter 1.2 --- Ion implantation of metal clusters --- p.3 / Chapter 1.3 --- Feature of MEVVA implantation --- p.5 / Chapter 1.4 --- Motivation and organization of this thesis --- p.7 / Chapter Chapter 2. --- Sample Preparation and Characterization Methods / Chapter 2.1 --- MEVVA implantation --- p.9 / Chapter 2.2 --- TRIM simulation --- p.11 / Chapter 2.3 --- Sample preparation --- p.14 / Chapter 2.4 --- Rutherford backscattering spectroscopy (RBS) --- p.16 / Chapter 2.5 --- X-ray diffraction (XRD) technique --- p.17 / Chapter 2.6 --- X-ray photoelectron spectroscopy (XPS) --- p.21 / Chapter 2.7 --- Transmission electron microscopy (TEM) technique --- p.24 / Chapter 2.8 --- Spectroscopic ellipsometry (S.E.) --- p.25 / Chapter 2.9 --- Z-scan technique --- p.32 / Chapter Chapter 3. --- Characterization of Single Implanted Samples / Chapter 3.1 --- Experimental results and discussion / Chapter 3.1.1 --- RBS --- p.35 / Chapter 3.1.2 --- XRD --- p.38 / Chapter 3.1.3 --- XPS --- p.42 / Chapter 3.1.4 --- XTEM --- p.49 / Chapter 3.1.5 --- S.E --- p.54 / Chapter 3.1.6 --- Z-scan measurements --- p.60 / Chapter 3.2 --- Summary --- p.65 / Chapter Chapter 4. --- Characterization of Sequentially Cu-Ni Implanted Samples / Chapter 4.1 --- Experimental results and discussion / Chapter 4.1.1 --- XRD --- p.66 / Chapter 4.1.2 --- XPS --- p.68 / Chapter 4.1.3 --- XTEM --- p.77 / Chapter 4.1.4 --- Z-scan measurements --- p.87 / Chapter 4.2 --- Summary --- p.91 / Chapter Chapter 5. --- Conclusion and Future Works / Chapter 5.1 --- Conclusion --- p.92 / Chapter 5.2 --- Future works --- p.93 / Appendix / Appendix I --- p.94 / Chapter ☆ --- Sample preparation procedures for XTEM / Appendix II --- p.97 / Chapter ☆ --- Alignment procedures of S.E. / Chapter ☆ --- Implementation of the Merlin system / Appendix III --- p.101 / Chapter ☆ --- Calibration of S.E. / Reference --- p.105

Yeung Chun Fai = 厚度和眞空熱處理對單晶 La0.67Ca0.33MnO3 薄膜特性之影響 / 楊進輝. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2000. / Includes bibliographical references. / Text in English; abstracts in English and Chinese. / by Yeung Chun Fai = Hou du he zhen kong re chu li dui dan jing La0.67Ca0.33MnO3 bo mo te xing zhi ying xiang / Yang Jinhui. / Acknowledgements --- p.i / Abstract --- p.ii / 論文摘要 --- p.iv / Table of contents --- p.v / List of Figures --- p.viii / List of Tables --- p.xiii / Chapter Chapter I --- Introduction / Chapter 1.1 --- Development of magnetoresistance materials --- p.1-1 / Chapter 1.1.1 --- Magnetoresistance (MR) --- p.1-1 / Chapter 1.1.2 --- Anisotropy magnetoresistance (AMR) --- p.1-1 / Chapter 1.1.3 --- Giant magnetoresistance (GMR) --- p.1-2 / Chapter 1.1.4 --- Colossal magnetoresistance (CMR) in rare-earth manganites --- p.1-3 / Chapter 1.1.5 --- Possible origin of CMR in rare-earth manganites --- p.1-4 / Chapter 1.1.5.1 --- Double exchange mechanism --- p.1-4 / Chapter 1.1.5.2 --- Jahn-teller effect --- p.1-6 / Chapter 1.1.5.3 --- Other mechanisms --- p.1-7 / Chapter 1.1.6 --- Possible origins of CMR in Thallium manganite pyrochlores (TI2Mn207) --- p.1-7 / Chapter 1.2 --- New developments in manganite materials --- p.1-8 / Chapter 1.3 --- Our approach --- p.1-8 / Chapter 1.3.1 --- Why choose La0 .67Ca0.33Mn03 material? --- p.1-8 / Chapter 1.3.2 --- The role of oxygen content in manganite materials --- p.1-9 / Chapter 1.4 --- The scope of this thesis work --- p.1-11 / References --- p.1-12 / Chapter Chapter II --- Instrumentation / Chapter 2.1 --- Thin film deposition --- p.2-1 / Chapter 2.1.1 --- Introduction --- p.2-1 / Chapter 2.1.2 --- Facing-target sputtering (FTS) --- p.2-3 / Chapter 2.1.3 --- Deposition profile calculation for sputtering with FTS --- p.2-4 / Chapter 2.1.4 --- Vacuum system --- p.2-7 / Chapter 2.2 --- Characterization --- p.2-8 / Chapter 2.2.1 --- Profilometer --- p.2-8 / Chapter 2.2.2 --- Atomic force microscopy (AFM) --- p.2-8 / Chapter 2.2.3 --- X-ray diffraction (XRD) --- p.2-8 / Chapter 2.2.4 --- Resistance and magnetoresistance measurement --- p.2-10 / Chapter 2.2.5 --- Hall effect measurement --- p.2-11 / References --- p.2-13 / Chapter Chapter III --- Epitaxial growth of La0.67Ca0.33 Mn03 thin films / Chapter 3.1 --- Introduction --- p.3-1 / Chapter 3.2 --- Fabrication and characteristics of LCMO target --- p.3-1 / Chapter 3.3 --- Substrate materials --- p.3-5 / Chapter 3.4 --- Deposition --- p.3-10 / Chapter 3.4.1 --- Sample preparation --- p.3-10 / Chapter 3.4.2 --- Substrate temperature --- p.3-10 / Chapter 3.4.3 --- Deposition process --- p.3-17 / Chapter 3.5 --- Post-annealing effect --- p.3-18 / Chapter 3.6 --- Film composition analysis --- p.3-22 / Chapter 3.7 --- Epitaxial growth examination --- p.3-22 / References --- p.3-27 / Chapter Chapter IV --- Thickness effect in single-crystal LCMO thin films grown on NGO and STO / Chapter 4.1 --- Motivation --- p.4-1 / Chapter 4.2 --- Resistance measurement --- p.4-2 / Chapter 4.3 --- Magnetoresistance (MR) --- p.4-8 / Chapter 4.4 --- Crystal structure --- p.4-12 / Chapter 4.5 --- Surface morphology --- p.4-16 / Chapter 4.6 --- Hall effect measurement --- p.4-19 / Chapter 4.6.1 --- Basic principle --- p.4-19 / Chapter 4.6.2 --- Experiment --- p.4-20 / Chapter 4.6.3 --- Carrier concentration & mobility --- p.4-20 / Chapter 4.7 --- Discussions --- p.4-25 / References --- p.4-27 / Chapter Chapter V --- Strain dependent vacuum annealing effectin single-crystal La0.67Ga0.33MnO3 thin films / Chapter 5.1 --- Motivation --- p.5-1 / Chapter 5.2 --- Sample description --- p.5-1 / Chapter 5.3 --- Vacuum annealing process --- p.5-2 / Chapter 5.4 --- Crystal structure --- p.5-2 / Chapter 5.5 --- Resistance measurement --- p.5-6 / Chapter 5.6 --- Discussions --- p.5-8 / Chapter 5.6.1 --- Lattice expansion --- p.5-8 / Chapter 5.6.2 --- Determination of oxygen content --- p.5-9 / References --- p.5-11 / Chapter Chapter VI --- Activation energy of small polaron in La0.67Ca0.33MnO3 thin films / Chapter 6.1 --- Motivation --- p.6-1 / Chapter 6.2 --- Basic theory --- p.6-1 / Chapter 6.2.1 --- Variable range hopping --- p.6-1 / Chapter 6.2.2 --- Semiconduction --- p.6-2 / Chapter 6.2.3 --- Nearest-neighbor hoping of small polarons --- p.6-2 / Chapter 6.3 --- Sample description --- p.6-3 / Chapter 6.4 --- Resistance measurement --- p.6-4 / Chapter 6.5 --- Activation energy --- p.6-4 / Chapter 6.6 --- Discussions --- p.6-5 / References --- p.6-12 / Chapter Chapter VII --- Conclusions --- p.7-1

by Poon Chun Yu. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (leaves 110-112). / Abstracts in English and Chinese. / ACKNOWLEDGEMENTS --- p.2 / ABSTRACT --- p.3 / TABLE OF CONTENTS --- p.5 / LIST OF FIGURES --- p.8 / LIST OF TABLES --- p.13 / Chapter CHAPTER 1 --- INTRODUCTION --- p.14 / Chapter 1.1 --- Overview --- p.14 / Chapter 1.2 --- Ferromagnetism --- p.15 / Chapter 1.3 --- Ferromagnetic granular thin film --- p.16 / Chapter 1.4 --- Ferromagnetism-magnetization --- p.17 / Chapter 1.5 --- Ferromagnetism - magnetization of a polycrystalline --- p.18 / Chapter 1.6 --- Soft and hard magnetic materials --- p.21 / Chapter 1.7 --- Preparation methods --- p.22 / Chapter 1.8 --- This thesis --- p.24 / Chapter CHAPTER 2 --- SAMPLE PREPARATION AND EXPERIMENTAL METHODS --- p.25 / Chapter 2.1 --- Sample preparation --- p.25 / Chapter 2.1.1 --- The pulsed filtered cathodic arc co-deposition system --- p.25 / Chapter 2.1.2 --- Details of sample preparation --- p.27 / Chapter 2.1.3 --- Improvement of the target holder --- p.30 / Chapter 2.2 --- Rutherford backscattering spectrometry (RBS) --- p.30 / Chapter 2.3 --- X-ray diffraction (XRD) --- p.32 / Chapter 2.3.1 --- Diffraction technique --- p.32 / Chapter 2.3.2 --- Scherrer's formula --- p.35 / Chapter 2.4 --- Raman spectroscopy --- p.35 / Chapter 2.5 --- Transmission electron microscopy (TEM) --- p.36 / Chapter 3.5.1 --- The technique of transmission electron microscopy (TEM) --- p.36 / Chapter 3.5.2 --- Transmission electron microscopy (TEM) sample preparation --- p.37 / Chapter 2.6 --- X-ray photoelectron spectroscopy (XPS) --- p.41 / Chapter 2.6.1 --- The principle of XPS --- p.41 / Chapter 2.6.2 --- Qualitative analysis of XPS (chemical shift) --- p.43 / Chapter 2.7 --- Scanning probe microscopy (SPM) --- p.43 / Chapter 2.7.1 --- The principle of atomic force microscopy (AFM) --- p.43 / Chapter 2.7.2 --- Tapping mode atomic force microscopy --- p.44 / Chapter 2.7.3 --- Magnetic force microscopy (MFM) --- p.46 / Chapter 2.8 --- Vibrating sample magnetometer (VSM) --- p.47 / Chapter 2.8.1 --- The principle of VSM operation --- p.47 / Chapter 2.8.2 --- Useful of the pick up coils --- p.49 / Chapter 2.8.3 --- M-H Loop --- p.50 / Chapter 2.9 --- Four-contacts technique --- p.51 / Chapter CHAPTER 3 --- CHARACTERIZATION OF CO-DEPOSITED CO-C SAMPLES --- p.53 / Chapter 3.1 --- Introduction --- p.53 / Chapter 3.2 --- Results and discussion --- p.54 / Chapter 3.2.1 --- NRBS measurements --- p.54 / Chapter 3.2.2 --- X-ray diffraction --- p.57 / Chapter 3.2.3 --- Raman spectroscopy --- p.59 / Chapter 3.2.4 --- AFM and MFM measurements --- p.64 / Chapter 3.2.4.1 --- AFM result --- p.64 / Chapter 3.2.4.2 --- MFM result --- p.68 / Chapter 3.2.5 --- Vibrating sample magnetometer (VSM) measurements --- p.73 / Chapter 3.3 --- Summary --- p.78 / Chapter CHAPTER 4 --- CHARACTERIZATION OF CO-DEPOSITED FE-C SAMPLES --- p.79 / Chapter 4.1 --- Introduction --- p.79 / Chapter 4.2 --- Results and discussion --- p.80 / Chapter 4.2.1 --- NRBS measurement --- p.80 / Chapter 4.2.2 --- X-ray diffraction --- p.81 / Chapter 4.2.3 --- x-ray photoelectron spectroscopy (XPS) --- p.84 / Chapter 4.2.4 --- AFM results --- p.87 / Chapter 4.2.5 --- MFM results --- p.91 / Chapter 4.2.6 --- Vibrating sample magnetometer (VSM) measurements --- p.95 / Chapter 4.2.7 --- Resistivity --- p.99 / Chapter 4.2.8 --- Transmission electron microscopy (TEM) --- p.100 / Chapter 4.3 --- Application potential --- p.101 / Chapter 4.4 --- Summary --- p.104 / Chapter CHAPTER 5 --- CONCLUSION --- p.106 / Chapter 5.1 --- Main results of this work --- p.106 / Chapter 5.2 --- Future work --- p.108 / REFERENCE --- p.110 / PUBLICATIONS --- p.112 / APPENDIX --- p.113

Partiendo de la motivación de buscar medios que permitan el ahorro de energía tanto por el aspecto económico como el ecológico se desarrolló este trabajo el cual pretende diseñar un controlador predictivo basado en modelo (CPBM) para controlar un generador de vapor de tubos de agua de forma más efectiva y eficiente que los sistemas actuales Para este fin se realizó una revisión del estado del arte de los generadores de vapor y de sus sistemas de control donde se identificaron las principales variables a controlar. Debido al bajo desempeño de estos sistemas de control se propuso, luego de un análisis previo, el uso de un controlador predictivo basado en modelo para su aplicación en el generador de vapor. Para lograr este objetivo se estudió un modelo matemático no lineal multivariable de un generador de vapor reportado en la literatura, el cual posteriormente se utilizó para realizar la simulación de la planta real. Luego para el diseño del controlador se utilizó el modelo linealizado con el fin de aligerar cálculos. El diseño del controlador multivariable está basado en un controlador predictivo que es computacionalmente más eficiente que el controlador predictivo convencional. Para la aplicación de este controlador se consideraron restricciones en la señal de control y durante las pruebas simuladas en Matlab/Simulink se le introdujo señales ruidosas y perturbaciones alcanzando buenos resultados en eficiencia energética y de control superando al sistema actual basado en controladores PID. Finalmente se propuso la implementación práctica del controlador haciendo uso de un DSP hibrido. / Tesis

Hong Liang = 用化学气相淀积方法生长氮化物纳米材料 / 洪亮. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references. / Text in English; abstracts in English and Chinese. / Hong Liang = Yong hua xue qi xiang dian ji fang fa sheng chang dan hua wu na mi cai liao / Hong Liang. / Acknowledgements --- p.ii / Abstract --- p.iii / Contents --- p.v / Chapter Chapter 1 --- Introduction / Chapter 1.1 --- Background --- p.1 / Chapter 1.2 --- Motivation --- p.2 / Chapter 1.2.1 --- A1N and AlGaN nanowires --- p.2 / Chapter 1.2.2 --- CVD --- p.3 / Chapter 1.3 --- Our work --- p.3 / Chapter Chapter 2 --- Experiment --- p.7 / Chapter 2.1 --- CVD system --- p.7 / Chapter 2.2 --- Sources and Substrates --- p.7 / Chapter 2.3 --- Growth of A1N nanowires --- p.8 / Chapter 2.4 --- Growth of AlGaN nanowires --- p.9 / Chapter Chapter 3 --- Characterization --- p.11 / Chapter 3.1 --- Scanning Electron Microscopy --- p.11 / Chapter 3.1.1 --- Topographic images by secondary electrons --- p.11 / Chapter 3.1.2 --- Elemental Analysis by Energy Dispersive X-ray --- p.12 / Chapter 3.2 --- Transmission Electron Microscopy --- p.12 / Chapter 3.3 --- X-Ray Diffraction --- p.14 / Chapter 3.4 --- Micro-Raman --- p.15 / Chapter Chapter 4 --- Results and Discussion --- p.18 / Chapter 4.1 --- A1N nano-structures --- p.18 / Chapter 4.1.1 --- A1N nano-leaves grown on silicon substrates --- p.18 / Chapter 4.1.2 --- A1N nanowires grown on silicon substrates --- p.19 / Chapter 4.1.3 --- SiNx nanowires grown on silicon substrates --- p.22 / Chapter 4.1.4 --- A1N nanowires grown on sapphire substrates --- p.26 / Chapter 4.1.5 --- Comparison with the results of other research groups --- p.31 / Chapter 4.2 --- AlGaN nano-structures --- p.33 / Chapter 4.2.1 --- AlGaN nanowires grown on silicon substrates --- p.33 / Chapter 4.2.2 --- Temperature dependence --- p.38 / Chapter 4.2.3 --- The influence of the mass ratio (Ga/Al) in the precursor metal sources --- p.43 / Chapter 4.2.4 --- Substrate effect --- p.46 / Chapter Chapter 5 --- Suggestion of the growth mechanism --- p.51 / Chapter 5.1 --- Growth mechanisms: an introduction --- p.51 / Chapter 5.2 --- The growth mechanisms for our produced samples --- p.57 / Chapter 5.2.1 --- Growth mechanism for A1N nanowires --- p.58 / Chapter 5.2.2 --- Growth mechanism for AlGaN nanowires --- p.61 / Chapter 5.2.3 --- Substrate effect --- p.65 / Chapter Chapter 6 --- Conclusions --- p.71 / Appendix --- p.73

Thesis (Ph.D.)--Boston University / PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you. / The purpose of the dissertation is to present and discuss the areal distribution of dew point and vapor pressure near the ground in the United States less Hawaii and Alaska. The analysis is based on hourly psychrometric observations at nearly 200 stations for lengths of record which average ten years. Maps of average monthly dew point and its standard deviation, average monthly vapor pressure, and maps presenting four characteristic types of diurnal variation of dew point each month are included in an Appendix to the dissertation. The history of the development of knowledge of water vapor in the atmosphere is also covered in an Appendix to add perspective to the study. The maps are a contribution to the climatography of the United States since the standard maps of average monthly vapor pressure still in use were prepared in 1917, and there are no previous maps showing the several measures of variability of average water vapor content of the air near the ground included in this study [TRUNCATED] / 2031-01-01

Vita. / Digitized by Kansas Correctional Industries

by Chen Dihu. / "November 1999." / Thesis (Ph.D.)--Chinese University of Hong Kong, 1999. / Includes bibliographical references (p. 160-173). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.