Thesis submitted in partial fulfilment of the requirements for the degree of Master of Management in Finance and Investment in the faculty of Commerce, Law and Management, Wits Businesss School, University of the Witwatersrand, 2012. / Idiosyncratic considerations relevant to South Africa’s economic and legal framework, as well as determining factors taken from the financial markets and the asset being auctioned are used to critically review the current auction mechanism used by the South African government to borrow funds publicly. A logistic regression with panel data is used in the empirical analysis. The dependent variable has a dichotomous outcome of uniform-price and discriminatory auction mechanisms. Data from 43 different countries over the period 2005 to 2011 are used for the analysis. It was hypothesized that countries with higher uncertainty about the price of their public debt, should use the auction mechanism that reduces under-pricing. Results from the logit regression supported this view. Upon comparing South Africa’s profile with the logit regression results, alongside a review of the literature, it becomes apparent that the proposed model does not provide a definitive answer. However, the model does aid policymakers’ decision on which auction mechanism should be preferred over the other for South Africa.

Thesis advisor: Rebecca Lowenhaupt / This qualitative case study examined the mechanisms employed by a public school Superintendent and Chief Academic Officer to support district wide curriculum reform. Utilizing organizational learning theory as a frame, the study aims to uncover the extent to which the district functions as learning organization. A learning organization can be characterized by a systematic approach to the acquisition and distribution of information to then retrieve and uniformly interpret new knowledge for the organization’s future use. Interview data and document analyses revealed strong evidence of organizational learning mechanisms employed by the Superintendent and Chief Academic Officer. Specifically, strategies for information acquisition and distribution were highly utilized, as well as structures for accountability including supervision, coaching models and a focus on data use. These district administrators delegated roles and meeting structures to support curricula adaptation, including heavy reliance on the instructional leadership of coaches and directors. With the goal of improving student outcomes via curricula reform, such structures facilitated adaptation and engagement in new learning by various members of the school district. / Thesis (EdD) — Boston College, 2016. / Submitted to: Boston College. Lynch School of Education. / Discipline: Educational Leadership and Higher Education.

Neste trabalho foi realizado um estudo das interações entre o corante catiônico azul de metileno com partículas de argilas em suspensão aquosa, visando detectar processos de migração de moléculas de corante entre partículas de argila. Até o momento as interações entre moléculas de corante e partículas de argila vem sendo descritas tendo-se em conta dois processos, um deles devido a adsorção de moléculas de corante nas superfícies externas e migração do corante para a região interlamelar, e outro devido as interações partícula-partícula, onde as interações entre as partículas de argila levam a formação de aglomerados de partículas, com o corante aprisionado nas regiões internas formadas. Há fortes indícios da ocorrência da migração de moléculas de corante entre partículas de argila, porém não houve detecção direta deste processo. No presente trabalho, foi idealizada uma metodologia que permitiu detectar variações espectrais, as quais podem ser atribuídas ao processo de migração de corante entre partículas de argila. A metodologia empregada consistiu na adição de suspensão de argila à suspensão argila-corante. Foram realizadas medidas espectrofotométricas na região do visível, em função do tempo, a partir do instante em que as suspensões são misturadas. Os espectros determinados para as amostras foram comparadas com os espectros determinados para a amostra de referência, a qual foi preparada pela adição de água a suspensão corante argila. Os resultados mostraram que as amostras e a referência apresentam comportamento espectral distinto, este comportamento pode ser atribuídos a migração de moléculas de corante entre partículas de argila. De forma geral, verificou-se que a migração do corante entre partículas ocorre preferencialmente para as partículas da argila SWy-1, pois esta argila apresenta a região interlamelar disponível para a adsorção das moléculas de AM, onde ocorre a protonação da molécula do corante, tornado-a mais estável. Os experimentos utilizando membrana de diálise mostraram que quando as suspensões estão isoladas pela membrana a migração das moléculas de corante entre partículas de argila não ocorre, é necessário uma interação ou contato entre as partículas para que a migração ocorra. / In the present work, studies on the interaction between the cationic dye methylene blue and clay particles in aqueous suspension are presented, aiming to detect migration processes of dyes molecules between clay particles. Up to now, the interaction between dye molecules and clay particles is described considering mainly two processes, one due to the adsorption of the dye molecules onto the outer surfaces of the clay particles, and subsequent migration toward the inner surfaces of the clay tactoids. The other process involves particle-particle interaction; the interaction between clay particles promotes particle agglomeration, with dye molecules being trapped in the internal sites formed between particles. There are strong evidences that dye molecules can exchange between dye coated particles, and in the present study a methodology was idealized to detect spectral changes, which could be attributed to migration of dye molecules between clay particles. According to the methodology used, clay particles were added to a dye-clay suspension and spectrophotometric measurements in the visible region was taken after different time intervals. The results were compared with reference spectra, determined for samples prepared adding water to the clay-dye suspension. The results showed that the spectral behavior of the samples and the reference were different, and this behavior can be attributed to the migration of adsorbed dye molecules between clay particles. It was observed that migration occurs preferentially in a direction towards the SWy-1 clay particles. The clay SWy-1 has interlamellar surfaces available to the dye adsorption. In the interlamellar region there are acids sites, where the dyes molecules are protonated. The protonation of dye molecules stabilize the adsorbed molecules. The experiments using dialysis membrane showed that when the particles are isolated by a membrane, the migration between clay particles do not occur, indicating that a close contact or interaction between the clay particles is necessary to the migration occur.

by Lo, Ka-wah. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1995. / Includes bibliographical references (leaves 76-81 (2nd gp.)). / Acknowledgments --- p.i / Abstract --- p.ii / Notations --- p.iii / List of Figures --- p.v / List of Tables --- p.vii / Chapter 1. --- Introduction / Chapter 1.1 --- Motivation --- p.1 / Chapter 1.2 --- Literature Review --- p.4 / Chapter 1.3 --- Objective --- p.10 / Chapter 2. --- Comparison of Different Approaches / Chapter 2.1 --- Sample Manipulator --- p.11 / Chapter 2.1.1 --- Force Decomposition Method --- p.12 / Chapter 2.1.2 --- Forward Rate Kinematics Base Method --- p.15 / Chapter 2.1.3 --- Grassmann Geometry Method --- p.18 / Chapter 2.2 --- Comparison Criteria --- p.20 / Chapter 2.2.1 --- Computational Complexity --- p.20 / Chapter 2.2.2 --- Scope of Application --- p.22 / Chapter 2.3 --- Summary --- p.23 / Chapter 3. --- Enumeration of Configuration Singularity / Chapter 3.1 --- Novel 6 DOF --- p.25 / Chapter 3.1.1 --- Result Analysis --- p.31 / Chapter 3.2 --- A 3 DOF with Symmetric Base --- p.33 / Chapter 3.2.1 --- Result Analysis --- p.35 / Chapter 3.3 --- A 3 DOF with Non-Symmetric Base --- p.36 / Chapter 3.3.1 --- Result Analysis --- p.37 / Chapter 3.4 --- A New Model of 6-SPS Defined by Kong et al --- p.40 / Chapter 3.5 --- A New Class of 6-SPS Platform-Type Parallel Manipulator --- p.45 / Chapter 3.5.1 --- The Hexagonal Base --- p.46 / Chapter 3.5.2 --- The Pentagonal Base --- p.50 / Chapter 3.5.3 --- The Tetragonal Base --- p.52 / Chapter 3.5.4 --- The Triangular Base --- p.55 / Chapter 3.6 --- Summary --- p.59 / Chapter 4. --- Numerical Analysis / Chapter 4.1 --- Parameter Analysis --- p.60 / Chapter 4.1.1 --- One Unknown Variable --- p.61 / Chapter 4.1.2 --- Two Unknown Variables --- p.63 / Chapter 4.2 --- Critical Value of Ratio R/q --- p.69 / Chapter 4.3 --- Summary --- p.72 / Chapter 5. --- Conclusions and Future Work / Chapter 5.1 --- Conclusions --- p.73 / Chapter 5.2 --- Future Work --- p.75 / References --- p.76 / Appendix --- p.82

The objective of the thesis is to understand the particle/substrate interaction of micron-sized High Purity (HP) aluminum (Al) powder particles with varying surface oxide/hydroxide layers, during single particle impact and determine the critical impact velocity (CIV). Advancements in analytical techniques enable in-situ supersonic impact of individual metallic micro-particles on substrates with micro-scale and nanosecond-level resolution. This novel capability allowed direct observation and measurement of a material-dependent threshold velocity, above which the particle underwent impact-induced material ejection and adhered to the substrate, (critical impact velocity). The data was then compared to empirical, as well as predicted values of the CIV from published data that were based upon theoretical iso-entropic fluid dynamics models. A major emphasis of this research was to perform, in-depth characterization of the Al powder in the as-received, gas atomized state and subsequent to controlled temperature and humidity exposure (designed to form a prescribed oxide and/or hydroxide surface layer) and finally after single particle impact. Analytical techniques including XPS, ICP, IGF, TEM and SEM were performed to determine the species of oxide and/or hydroxide, bulk chemical composition, oxygen content and thickness of the surface oxide/hydroxide layer. Finally, bulk samples of material were produced by the cold spray process, from powder representing select test groups and subsequently characterized to determine tensile and hardness properties, chemistry, microstructure and conductivity. A fundamental understanding of the role of surface oxidization in relationship to particle deformation during impact and the bonding mechanism will be applicable toward the development of optimized parameters for the cold spray (CS) process. Results from this study will aid in the development of industrial practices for producing, packaging and storing Al powders.

"Escapement mechanisms hold back a stream of parts driven either by mechanical or pneumatic means for a length of time and release a single part as required to an assembly station. They are used in most automatic multi-component assembly equipment. They occupy a significant design space and have dynamic characteristics of their own. This research aimed to develop a novel high speed mechanism for parts escapement that occupies less design space and contributes less to the dynamic activity of the structure. Several conceptual mechanisms were generated and evaluated. A compliant mechanism that amplifies the very small displacement of a piezo actuator was selected for detailed design. A proof of concept prototype was fabricated and tested. A piezo stack was used to bend a thin, spring steel, compliant beam. Its deflection was further amplified by attaching a comparatively rigid beam extension at the end of the compliant section. The mechanism escapes parts at 16 Hz using constrained layer damping on the beam to reduce vibrations. The concept is feasible to use on production machinery and provides advantages in terms of higher operating speeds and compactness. The concept could also be used where there is a requirement of high speed gating."

"Learning lessons from nature is the key element in the design of tough and light composites."

As interações entre as moléculas de corante e as partículas de argila em suspensão podem envolver diferentes processos dependendo da argila e da maneira pela qual as suspensões corante/argila são preparadas. Os processos que ocorrem são: a adsorção de moléculas de nas superfícies externas das partículas de argila seguidas de migração para as regiões interlamelares, outro processo é devido a interações partícula-partícula, onde as moléculas de corante ficam envoltas em aglomerados de partículas de argila e um terceiro processo é devido a migração das moléculas de corante entre partículas de argila. No presente trabalho foi estudada a influência de diferentes metodologias nos processos de migração de moléculas do corante azul de metileno (AM) entre partículas de argilas em suspensão aquosa. Experimentos adicionando-se partículas de argila nas suspensões corante/argila foram realizados com acompanhamento das variações espectrais em função do tempo. Foi possível detectar variações espectrais nas suspensões corante/argila atribuídas a processos de migração de moléculas de corante adsorvidas em partículas de argila para outras partículas na suspensão. Os resultados indicaram que o processo de migração entre diferentes partículas de argila depende da razão corante/argila. Em outro tipo de experimento, utilizando diferentes formas de adição do corante à suspensão de argila (lenta, rápida e diálise) constatou-se que o modo de adição do corante pode afetar os processos de adsorção, para alguns sistemas corante/argila é muito importante considerar a forma de adição do corante à suspensão de argila, para que se tenham suspensões corante/argila com propriedades desejáveis. / Interactions between dye molecules and suspended clay particles may follow different processes depending on how the dye/clay suspensions are prepared. The processes that occur are: adsorption of molecules on the external surfaces of clay followed by migration to the interlamelar areas, another process is due to particle-particle interactions, in which the dye molecules are wrapped in clay particle agglomerates and a third process due to the migration of the dye molecules between clay particles. In the presente work the influence of different metodologies on the migration processes for the methylene blue dye between clay particles in aqueous suspension was studied. Experiments adding clay particles to the system dye/clay were done monitoring following the spectral changes in function of time. It was possible to detect spectral variations in the dye/clay suspensions attributed to the migration of adsorbed dye molecules to other particles in the suspension dye molecules adsorbed in clay particles migration process. The results indicated that the migration process between different clay particles depend on the nature of the clay and on the dye/clay ratio. In another type of experiment, using different forms for adding dye to the clay suspension (slow, fast and dialysis) it was seen that the adding way for the dye can affect the adsorption processes, for some dye/clay systems it is very important to consider the adding way of the dye to the clay suspension, so that dye/clay suspensions with desirable properties are obtained.

How important is the financial market for economic growth? It can be argued that from the supply perspective that a well-functioning stock market boosts economic growth by lowering the cost of the firm to access public funds for new investment opportunities to expand business and production. Another view suggests that from the demand perspective that stock markets create a wealth effect on consumption for economic growth. In turn, the growth induces more demand for financial services and so the growth of the stock market. Both the supply and the demand argument imply a positive relationship between the stock market and the economy. Exactly how the behaviour of investors in trading stocks on a stock market can affect the performance of the firm is unclear. The study of this question helps to understand how stock trading activities can affect manufacturing production and so the growth of an economy from the perspective of the micro structure of a market. China as the largest emerging economy in the world has experienced the fastest growth of the economy and rapid development of its stock market over the last 30 years. It provides us with an excellent case to study the question on how the momentum of paper trading of shares can be transmitted to the growth of industry and firms which is a determined part of a real economy. The thesis takes China to study the question in an attempt to discover the micro mechanism of transmission as its key contribution to the existing literature on the study of the stock market effect on economic growth. The thesis employs a fixed effects model to estimate longitudinal firm-level data comprising 2233 heterogeneous Chinese listed firms over the period 2005-2015. In our estimation, it finds how stronger stock-trading performance can induce an increase in external funding of the firm. It then shows how the improvement in a firm's financing ability will turn to improvements in inter-firm reallocations of resources towards the more productive firms. However, the presence of equity over-trading appears to hinder the growth of firm business, possibly because the negative externalities of the speculative trading outweigh the effect of the positive externalities, such as excessive volatility that creates high risk of stock investment. Overall, empirically, the thesis establishes a micro-economic structure of transmission from stock trading activities to the growth of the firm. The structure explains the importance of stock markets on economic growth from the supply perspective of an economy.

The application of MIDA boronates (MIDA = N-methyliminodiacetic acid) in Suzuki- Miyaura reactions has increased over the last years. This is mainly because in many cases, the replacement of the boronic acid for the respective MIDA boronate has a positive result in the reaction yield. The key feature that makes MIDA boronates efficient coupling partners is that they can undergo a slow hydrolysis reaction under Suzuki-Miyaura conditions, which generates the boronic acid in situ. The control of the hydrolysis rate is crucial to keep a low concentration of the boronic acid to avoid some of the side reactions frequently observed. The kinetics of the hydrolysis reaction from a range of alkyl, aryl, and heteroaryl MIDA boronates have been determined under different reactions conditions. In addition, competition experiments and computational calculations have resulted in the proposal of three distinct mechanisms for the hydrolysis of MIDA boronates: ‘base-promoted’, ‘water-promoted’, and ‘acid-promoted’. The base and acid mediated processes occur at faster rates than the neutral pathway and involves a rate-limiting addition at the MIDA carbonyl carbon by hydroxide or water, respectively. Whilst the 'neutral' hydrolysis requires neither base nor acid and involves ratelimiting B-N bond cleavage by a water cluster. Under certain conditions the neutral mechanism can operate in parallel with the base or with the acid mediated mechanism; relative rates are easily quantified by 18O incorporation in the MIDA, after this is released from the hydrolysis reaction. This insight is expected to assist informed application and optimisation of MIDA boronates in synthesis as well as the design of new MIDA boronate derivatives.