Die erfolgreiche Optimierung der Leistung von thermoelektrischen Materialien, die durch zT beschrieben wird, ist entscheidend für ihre Anwendung für das Wärmemanagement und die Kühlung von Leistungselektronik. Im Gegensatz zu Bulk-Proben bleibt die vollständige zT-Charakterisierung von Dünn- und Dickfilmmaterialien eine große Herausforderung. Dies ist insbesondere relevant für Filme, die durch elektrochemische Abscheidung synthetisiert werden, wo das Material auf eine elektrisch leitende Schicht abgeschieden wird. In dieser Dissertation habe ich ein Transport-Device für eine vollständige zTCharakterisierung von elektrochemisch abgeschiedenen Materialien entwickelt, während der Einfluss der elektrisch leitenden Schicht, sowie des Substrats beseitigt wird. Die zT-Charakterisierung erfolgt unter Verwendung eines auf einer freistehenden Membran suspendierten thermoelektrischen Materials innerhalb des entwickelten Transport-Devices, die durch eine Kombination von Fotolithografie und Mikrostrukturierungstechnik zusammen mit Ätzprozessen hergestellt wurde. Für die Messung der Wärmeleitfähigkeit habe ich eine eindimensionale, analytische, stationäre Methode eingesetzt, welche mit Hilfe von dreidimensionalen Finite-Elemente-Simulationen bestätigt wurde. Darüber hinaus habe ich die temperaturabhängigen thermoelektrischen Eigenschaften von zwei Dickschichten mit Hilfe des entwickelten Devices untersucht und mit Bulk-Proben und Dünnfilmen verglichen. Auf diese Weise konnte die Validität des Transport-Devices nachgewiesen werden. Neben der Optimierung von mikro-thermoelektrischen Materialien, die mit dem Transport- Device charakterisiert werden, ist die Leistung von thermoelektrischen Devices von den Faktoren Design, Geometrie und Konstruktion beeinflusst. Daher habe ich den Einfluss der Geometrie auf die Leistung eines elektrochemisch hergestellten mikrothermoelektrischen Generators mit Hilfe einer Finite-Elemente-Simulation untersucht.

In recent decades the development of technologies capable to offer highly localized and precise temperature control has received increasing attention due to their relevance and applicability in numerous engineering fields. Multiple scientific papers have been written that focus on the enhancement of the performance of thermoelectric materials and micro-devices. This Ph.D. thesis in the field of Mechanical Engineering pursues three main research goals regarding electrothermal phenomena: (1) To provide an optimization design strategy for micro-thermoelectric coolers by analyzing the interplay between electrical and thermal fluxes during device operation. (2) To analyze the suitability of a device, based on micro-thermoelectric coolers, for controlling the thermal environment in microbiological systems. (3) To develop an experimental technique, based on optical pump-probe thermal imaging, to extract the thermal conductivity anisotropy of thin films. For this purpose, numerical simulations and experiments were carried out. The results show, that the design of micro-thermoelectric devices must take into account the impact of parameters that are typically neglected in the construction of macro scale devices. Poorly designed parameters, such as the metallic contacts, the distance between thermoelectric elements and their interaction with the substrate, carry severe reductions of the performance of micro-thermoelectric devices. It is demonstrated that the optimal performance is achieved when the thermoelectric legs are properly dimensioned, so that a balance of the Fourier and Joule fluxes is reached. Numerical analyses prove that micro-thermoelectric coolers offer a feasible alternative to overcome the current spatial and temperature limitations of conventional technologies and therefore enable to investigate the thermal environment of biological systems at the micro-scale. Guidelines for the implementation of the experimental platform are provided. The evaluation of the numerical and experimental data proves that optical pump-probe thermal imaging is suitable to characterize both the in-plane and the through-plane thermal conductivity of thin films. The experimental conditions to extract the anisotropy of the sample under study are determined. The outcome of this work yields new insights into electrothermal phenomena at the micro-scale and thus creates new routes in the design, fabrication and characterization of micro- thermoelectric materials and devices.:Acknowledgements IV Erklärung der Urheberschaft VI Summary VII Zusammenfassung VIII Table of content IX List of figures XI List of tables XIV Abbreviations and symbols XV 1 Introduction 1 1.1 Motivation 1 1.2 Outline of the thesis 4 1.2.1 Chapter 2 - Fundamentals 4 1.2.2 Chapter 3 - Design guidelines of micro-thermoelectric coolers 4 1.2.3 Chapter 4 - Development of a platform for biological systems experimentation 4 1.2.4 Chapter 5 - Development of a technique for thermal transport characterization in thin films 5 1.2.5 Chapter 6 - Main conclusion and future research 5 1.3 Main research objectives 5 2 Fundamentals 7 2.1 Thermoelectric phenomena 7 2.2 Performance estimation of micro-thermoelectric coolers 10 2.3 Finite element modelling 12 2.3.1 Introduction to finite element modelling 12 2.3.2 Finite element modelling of thermoelectric phenomena 17 2.4 Thermoreflectance imaging microscopy 19 3 Design guidelines of micro-thermoelectric coolers 26 3.1 Introduction 26 3.2 Micro-thermoelectric coolers: an alternative for thermal management 28 3.3 Analysis approach 29 3.3.1 Input current optimization 31 3.3.2 Metallic contacts 32 3.3.3 Leg pair geometry 35 3.3.4 Fill factor 38 3.3.5 Experimental characterization of µTECs 41 3.4 Summary 44 4 Development of a platform for biological systems experimentation 46 4.1 Introduction 46 4.2 Thermal analysis on biological systems 48 4.3 Platform conceptual proposal 50 4.4 Analysis approach 52 4.4.1 Input current optimization 52 4.4.2 Fill material 54 4.4.3 Thermotaxis 55 4.4.4 Top material 56 4.4.5 Cold spot optimization 58 4.5 Experimental platform construction 59 4.6 Summary 62 5 Development of a technique for thermal transport characterization in thin films 64 5.1 Introduction 64 5.2 Thermal anisotropy characterization in thin films 65 5.3 Experimental apparatus 66 5.4 Experimental measurements 69 5.5 Analysis approach 72 5.5.1 Thermal conductivity anisotropy analysis 76 5.5.2 Effect of the laser power on the temperature distribution 79 5.5.3 Enhancement of the system sensitivity 80 5.6 Summary 83 6 Main conclusion and future research 85 6.1 Main conclusion 85 6.2 Outlook 88 7 References 89 8 Scientific output 97 8.1 Publications in peer review journals 97 8.2 Selected conference abstracts 98 9 Curriculum vitae 99

Climate change and land use transition are the main drivers of watershed hydrological processes. The main objective of this study was to assess the hydrometeorological responses to climate and land use changes in the Jhelum River Basin (JRB), Pakistan. The development of proper climate information is a challenging task. To date, Global Climate Models (GCMs) are used for climate projections. However, these models have a coarse spatial resolution, which is not suitable for regional/local impact studies such as water resources management in the JRB. Therefore, different downscaling methods and techniques have been developed as means of bridging the gap between the coarse resolution global models projection and the spatial resolution required for hydrological impact studies. Statistical Downscaling Model (SDSM) and Long Ashton Research Station Weather Generator (LARS-WG) are selected in this study for downscaling of temperature and precipitation. Both downscaling approaches consider three climate models and two emission scenarios (i.e., RCP4.5 and RCP8.5) in order to sample the widest range of uncertainties in climate projections. Current land use and land cover (LULC) maps are generated from Landsat imagery to analyze the pattern and dynamic of land use change. Both climate projections and LULC are fed into SWAT (Soil and Water Assessment Tool) hydrological model to investigate the streamflow dynamics. The results indicate good applicability of SDSM and LARS-WG for downscaling of temperature and precipitation in three future periods (2020s, 2050s and 2080s). Both models show an increase mean annual max temperature, min temperature and precipitation as 0.4-4.2°C, 0.3-4.2°C and 4.4-32.2% under both RCPs scenarios. Similarly, results of SWAT model suggest an increase in mean annual discharge about 3.6 to 28.8% under RCP4.5 and RCP8.5. The study also revealed that water yield and evapotranspiration in the eastern part of the basin (sub-basins at high elevation) would be most affected by climate change. The results of LULC change detection show that forest exhibited maximum positive change while agriculture showed maximum negative change during 2001-2018. SWAT model simulations suggested that implementation of afforestation in the watershed would reduce surface runoff and water yield while enhancing the evapotranspiration. It is recommended that authorities should pay attention to both climate change and land use transition for proper water resources management.

This thesis presents new insights into Alpine Fault structures at the drill site of the Deep Fault Drilling Project (DFDP)-2B at Whataroa in New Zealand. Despite the challenging conditions for seismic imaging within a glacial valley filled with sediments and steeply dipping valley flanks, several structures related to the valley itself as well as the tectonic fault system are imaged. The Alpine Fault at the West Coast in New Zealand is a major plate boundary forming a significant geohazard as large earthquakes (magnitude 7-8) occur regularly and the next earthquake is expected relatively soon. A major effort has been made to study the fault characteristics through scientific drilling in the Deep Fault Drilling Project (DFDP) Alpine Fault with the deepest DFDP-2B borehole located in the Whataroa Valley. A great variety of seismic data are newly acquired. First, the WhataDUSIE (Whataroa Detailed University Seismic Imaging Experiment) data set is a ~5 km long 2D profile acquired in 2011 prior to the drilling. As the 2D profile could not fully explain the 3D structures in the Whataroa Valley, an extended surface and borehole data set was acquired in 2016 after the drilling. This data set consists of shorter 2D lines (< 3 km), a dense 3D-array, and vertical seismic profiling (VSP) using the DFDP-2B borehole including the fibre-optic cable. 3D seismic data proved to be essential to understand the complex 3D structures of the glacial valley and the major fault. First-arrival travel time tomography and prestack depth migration (PSDM) are applied to obtain a P-wave velocity model and seismic images of the subsurface (<5 km). In this complex setting, the Fresnel volume migration (a focusing PSDM method) proved to best obtain structural information about the subsurface. Analysing the results of the seismic data processing, two major outcomes are achieved: improved knowledge about the glacial structures of the Whataroa Valley and structural images of the Alpine Fault zone. The Whataroa Valley is an overdeepened glacial valley with details of the basement topography visible in the seismic images. A deep trough is identified south of the DFDP-2B borehole with horizontal layering of the sediments. Valley flanks are identified in both the seismic images and the P-wave velocity model, particularly the western valley flank. Thus, Quaternary and glacial processes can be analysed with the help of the newly derived seismic images. The Alpine Fault is directly imaged with the seismic data, which is the first time in this region at shallow depths (<5 km). Several shorter fault segments between depths of 0.2 km and 2.2 km dipping 40-56° to the southeast are directly imaged. Further identified reflectors and faults are interpreted to represent Alpine Fault structures in the form of a damage zone and induced faults adding further complexity to the fault zone. In conclusion, the 3D seismic results presented in this thesis provide new insights into the Whataroa subsurface. Hence, the new results form a good basis for a deeper understanding of the Alpine Fault structures and underlying processes which is important for potential future drilling but also for the estimation of the geohazard in the region.

Sarcopenia is a disease of muscle wasting primarily seen in older adults. Although this term was first coined over three decades ago, there is a lack of consensus on a definition, screening criteria, and treatment protocol for sarcopenia. The primary purpose of this study is to determine whether registered dietitian nutritionists (RDNs) in the United States (U.S.) screen for sarcopenia. Study participants were recruited through a randomized email list and included RDNs throughout the U.S. Respondents completed a survey questioning knowledge of sarcopenia, screening tools and company protocols in place, and the need and desire for sarcopenia education. Data revealed a lack of pre-existing protocols in place, a dissonance of validated and unvalidated screening tools used in practice, and substantial need for sarcopenia education.

The overwhelming prevalence of child labour globally continues to be a matter of concern. Millions of children below the age of eighteen years are found engaging in exploitative and life-threatening economic activities, leaving them susceptible to human rights violations and ultimately death. The African continent accounts for a greater number of child labourers, calling therefore for an immediate action against child labour, particularly the worst forms of child labour. As a result of harsh and appalling social, economic, political and cultural realities evident within the continent, child labour remains inevitable for many African countries including the Kingdom of Lesotho. In an attempt to help their economically ailing families, children engage in labour activities as either sole providers or contributors to the little household income. Resultantly, a vast majority of children are found working within hazardous and unregulated informal sectors; comprising of street vendors, domestic workers, working on farms and caring for livestock to state but the least. Due to lack of official regulation of the informal sector, children are then exposed to abuse, exploitation and violation with little to no protection. In response to the incidences of child labour, several treaties and conventions aimed at protecting the rights of children and ultimately eradicating child labour have been adopted by both international and regional communities. These include the Convention on the Rights of the Child, International Labour Organisation Conventions on child labour, the United Nations Sustainable Development Goals (SDGs) target 8.7, which prohibits and seek to eliminate child labour by 2025, the African Charter on Human and People’s Rights as well as the African Charter on the Rights and Welfare of the Child among others. The endorsement and domestication of these treaties have been evident in many African countries including the Kingdom of Lesotho through the enactment of laws and adoption of policies aimed at promoting the rights of children and protecting children against harmful practices such as child labour. While there have been evident and positive progress in terms of the ratification of treaties and conventions that address the issues of child labour globally, the Kingdom of Lesotho included, child labour practices continues to be a challenge for Lesotho. The study identified that these could be attributed to the lack of implementation and enforcement of both adopted international conventions and enacted domestic laws in Lesotho, therefore a matter of concern. Moreover, failure to conform to international human rights treaties aimed at promoting and protecting the rights of children by the Kingdom of Lesotho has resulted in failure to protect children, particularly those involved in child labour. Furthermore, the evident inconsistencies and ambiguities in the definition of child labour, conception of work, childhood and adulthood, posed a major challenge in understanding the severity of the practice of child labour and its effects on children. Child labour should also be considered a security issue, calling therefore for an immediate action. It is however crucial to note that, while the Kingdom of Lesotho continues to grapple with the plight of child labour, a number of African countries have made great progress in responding to child labour and bringing about a reduction in its prevalence. This includes the Republic of South Africa, the Republic of Tanzania and the Kingdom of Morocco among others. Cognisant of these advancements, the study critically evaluated practices of child labour in these countries and the responses thereto as means to identify good practices to be emulated by the Kingdom of Lesotho. These good practices will help provide strategies that will ensure better protection for children involved in child labour and ultimately end the practice of child labour in the near future. / Thesis (DPhil)--University of Pretoria, 2020. / Mercantile Law / DPhil / Unrestricted

Magister Legum - LLM / Global climate change is a serious, severe, and potentially irreversible problem. If no actions are taken to curb greenhouse gas emissions, global temperatures and sea levels will rise, wreaking havoc on earth, particularly in developing countries. The Stockholm Declaration of 1972 facilitated the first international consensus concerning the application of CBDR to international environmental problems. This was in reaction to the developing countries refusal to adhere to the same standards as the developed countries as they perceived this as a burden to their economic growth, which is unjust due to the developed countries historical culpability.

Magister Legum - LLM / The common law duties have been preserved by the partial codification of the duties of directors in terms of the Companies Act of 2008 (‘2008 Act’). One such duty is the duty to disclose personal financial interest in terms of s 75 of the 2008 Act. The need for directors to disclose personal financial interest has become more necessary than ever before in South African companies, particularly State-Owned Companies (‘SOCs’), due to their role in the South African economy. The injury caused by the breach of this duty is not only to the company, but more harm is caused to the economy and the beneficiaries who are the recipients of services rendered by SOCs. There has been a plethora of media reports of poor corporate governance in SOCs which is attributed to conflict of interest due to failure of directors to disclose their personal financial interests in proposed transactions or approved agreements.

Magister Artium (Sport, Recreation and Exercise Science) - MA(SRES) / University student-athlete dropout continues to be a concern for many universities and has been the focus of many researchers globally. This qualitative study explored the factors that influenced students to dropout of a cricket and development programme at a university in the Western Cape metropole. Seven former student-athletes and two current administrators participated in this study. This study was guided by the Student Athlete Retention Model by Rivera (2004).

Philosophiae Doctor - PhD / Cardiovascular disease is amongst the top three leading causes of mortality in South Africa and the world. The effects of cardiovascular disease can be seen in limitations of function within all spheres of life, including work function. Cardiac rehabilitation programmes have been documented to improve functional abilities, but little is known about the return to work rate after cardiac rehabilitation. Access to cardiac rehabilitation programmes in the Western Cape is limited. This study aimed to determine the return to work rates and influencing factors after cardiac rehabilitation as well as to design an intervention programme that is accessible and could facilitate return to work for individuals with cardiovascular disease.