Philosophiae Doctor - PhD / Organic and inorganic pollutants are two broad classes of pollutants in the environment with their main sources from waste waters that are indiscriminately dumped from chemical related industries. Among the organic pollutants are dyes that come as effluents from the textile industries. Toxic metals are the main inorganic pollutants with their sources from industries such as mining, electroplating, batteries etc. The presence of both classes of pollutants in the aquatic environment poses a serious threat to aquatic organisms and humans who depend on these waters for domestic purpose. Therefore, this research focused on the fabrication of materials and designing of methods for removal of both classes of pollutants from their aqueous solutions.

Uplift of the Al Hajar Mountains in Oman has been related to either Late Cretaceous ophiolite obduction or the Neogene Zagros collision. To test these hypotheses, the cooling of the central Al Hajar Mountains is constrained by 10 apatite (U-Th)/He (AHe), 15 fission track (AFT), and four zircon (U-Th)/He (ZHe) sample ages. These data show differential cooling between the two major structural culminations of the mountains. In the 3km high Jabal Akhdar culmination AHe single-grain ages range between 392 Ma and 101 Ma (2 sigma errors), AFT ages range from 518 Ma to 324 Ma, and ZHe single-grain ages range from 62 +/- 3Ma to 39 +/- 2 Ma. In the 2 km high Saih Hatat culmination AHe ages range from 26 +/- 4 to 12 +/- 4 Ma, AFT ages from 73 +/- 19Ma to 57 +/- 8 Ma, and ZHe single-grain ages from 81 +/- 4 Ma to 58 +/- 3 Ma. Thermal modeling demonstrates that cooling associated with uplift and erosion initiated at 40 Ma, indicating that uplift occurred 30 Myr after ophiolite obduction and at least 10 Myr before the Zagros collision. Therefore, this uplift cannot be related to either event. We propose that crustal thickening supporting the topography of the Al Hajar Mountains was caused by a slowdown of Makran subduction and that north Oman took up the residual fraction of N-S convergence between Arabia and Eurasia.

Jag har undersökt hur användandet av två olika metoder i låtskrivning och musikproduktion som beskrivs i Seabrooks bok The Song Machine påverkar det slutliga klingande resultatet av en färdig produktion. Detta gjordes genom att producera fyra stycken låtar varav två metoder använts som kallas Melody & Hook och Track & Hook som innebär att melodin och till viss del text skrivs antingen först eller sist i arbetsflödet. När det klingande resultatet var färdigt jämfördes låtarna i deras sound i form av instrumentering, genretillhörighet och eventuella övriga effekter där min slutsats var att det inte var av större betydelse, men det som var av större betydelse var inspirationen som befann sig i stunden vid skrivandet av låten och mina val av instrument.

Magister Scientiae - MSc / South Africa s coal and platinum mineral resources are crucial resources towards creating an alternative and environmentally sustainable energy system. The beneficiation of these natural resources can help to enhance a sustainable and effective clean energy base infrastructure and further promote their exploration and exportation for economics gains. By diversification of these resources, coal and the platinum group metals (PGMs) especially palladium market can be further harnessed in the foreseeable future hence SA energy security can be guaranteed from the technological point of view. The South Africa power industry is a critical sector, and has served as a major platform in the South African socio-economic development. This sector has also been identified as a route towards an independent energy base, with global relevance through the development of membrane technologies to effectively and economically separate and purify hydrogen from the gas mixtures released during coal gasification. The South Africa power industry is a critical sector, and has served as a major platform in the SA's socio-economic development. This sector has also been identified as a route towards an independent energy base, with global relevance through the development of membrane technologies to effectively and economically separate and purify hydrogen from the gas mixtures released during coal gasification. Coal gasification is considered as a source of hydrogen gas and the effluent gases released during this process include hydrogen sulphide, oxides of carbon and nitrogen, hydrogen and other particulates. In developing an alternative hydrogen gas separating method, composite membrane based on organic-inorganic system is being considered since the other available methods of hydrogen separation are relatively expensive. The scientific approach of this study involves the use of palladium modified polyimide composite membrane. Palladium metal serves as hydrogen sorption material, deposited on polyimide substrates (composite film) by electroless technique. Polyimide is a class of polymer with excellent physico-chemical properties such as good mechanical strength, superior thermal stability and high resistance to chemical attack. In this study, a composite polymer-palladium membrane was developed and investigated to determine the prospect of using this membrane as a cheap, accessible, reliable and efficient system to separate and purify hydrogen gas. Prior to the palladium metal plating, the challenge of metal adhesion on glassy polymer such as polyimide film was addressed by chemical etching and unirradiated and irradiated polyimide film surface using NaOH, NaOCl and a mixture of NaOH/NaOCl solutions. The time of etching was varied and the overall effect of this surface treatment was deeply investigated using Fourier transform infrared (FTIR) spectroscopy. The FTIR study focused on the structural deformation of the polyimide functional group units and the emergence of ‘active sites’ along the polyimide backbone structures that have been identified to allow the Pd metal exchange on the functionalised polyimide film. The detailed use of FTIR spectroscopic technique in this study on the etched unirradiated and irradiated polyimide film was to understand the chemical interaction between the polyimide functional group units and the chemical etchants. The surface morphology of unirradiated and irradiated polyimide samples was studied using SEM, the depth profile (penetration) of palladium particles after electroless deposition on the polyimide matrix was investigated by SEM and TEM analysis. As for the alkaline etched irradiated polyimide, pore distribution, shape and size depended on the etching time and solution. In the XRD analysis, the palladium modified unirradiated polyimide film indicated the diffraction peaks of palladium metal in the (1,1,1), (2,2,0) and (2,0,0) planes present in the polyimide surface, and the peel test showed that the strength of adhesion of palladium on unirradiated surface was low compared to the palladium modified irradiated polyimide. The NaOH solution showed the best etchant at 20 minutes for the unirradiated palladium modified polyimide. The hallmark of this study was the design, fabrication and assemblage of home-built hydrogen diffusion reactor unit used to measure rate of hydrogen diffusion property of unirradiated and irradiated polyimide films from 25 °C to 325 °C. The rate of hydrogen diffusion was observed to depend on the etching time of polyimide surface before and after the polyimide surface irradiation treatment. / South Africa

The integration of low-temperature thermochronometers, including apatite and zircon (U-Th)/He (AHe, ZHe) and apatite fission-track (AFT) methods, allows for a quantification of the thermal history experienced by rocks as they heat and cool through upper crustal temperature regimes (<200°C). Whereas these methods are practical in geologic terranes that have undergone rapid cooling, application to strata with protracted cooling histories is complicated by the enhanced role of grain-specific parameters (volume, chemistry, radiation damage) on the kinetics of helium diffusion and fission track annealing. The effects of these variables are most prevalent in sedimentary samples, where natural variance in detrital accessory mineral populations results in a broad range of diffusion kinetics and great dispersion in corresponding cooling dates. This thesis integrates contemporary thermochronometer diffusion and annealing kinetics to investigate the burial and exhumation history of two natural laboratories. In the Mackenzie Mountains and Plain of the Northwest Territories, long-term radiation damage accumulation in zircon from Neoproterozoic siliciclastic units produces ZHe dates that track Albian to Paleocene burial and exhumation in front of the foreland-propagating fold-thrust belt. For the Phanerozoic stratigraphic section, AFT annealing kinetics are calculated from Devonian and Cretaceous samples, and are incorporated into multi-kinetic AFT modeling. These kinetics also constrain AHe date-radiation damage trends, and when combined allow for an estimation on the magnitude of eroded sediment across regional pre-Albian and post-Paleocene unconformities. Finally, conodont (U-Th)/He data from Anticosti Island, Québec in the Gulf of the St. Lawrence are compared with ZHe, AHe and AFT data to test their utility as a thermochronometer for carbonate basin analysis. These data evince a Mesozoic thermal history previously unattributed to the region. Ultimately, this thesis provides a novel assessment on the ways in which thermochronometer date dispersion can be quantified to assess the thermal evolution of sedimentary basins from burial through to inversion.

The study attempted to analyse the impacts of the ‘fast track’ land reform on maize production in Zimbabwe. This purpose was tackled by constructing a partial equilibrium model that depicted what could have happened if no further policy shifts had taken place after 2001. Setting up a partial equilibrium model required a sound understanding of the functioning of the Zimbabwe’s maize market. The institutional structure of the Zimbabwean maize market was explored to inform the model development process that would allow for the development of the baseline model. Developing the model started off with the estimation of single equations which were collapsed into a simultaneous system of equations through the use of a combination of ordinary least squares and generalised least squares techniques. The development of the simulation model required that assumptions be made for exogenous variables, and crafted assumptions were based on the 2000 macro-economic and institutional environment as well as agricultural policies. The re-simulated baseline model that was constructed in this study was used to make projections based on the various trends of exogenous variables in 2000. This means that the model generated an artificial data set based on what the maize market would have looked like under a set of the pre-2000 existent policy conditions. As such, all the shifts in the political and economic environment that took place after 2000 were not introduced in the model. The ‘fast track’ land reform policy was thus assessed based on the performance of the baseline model using a range of “what if” assumptions. Therefore, the re-simulated baseline solutions discussed result not only from policy shifts that occurred before 2000, but also from the convergence of hypothetical political and economic stability within the period in question. The results of the re-simulated baseline indicated that the commercial area harvested was negatively affected by the expropriation of commercial farms. The arguments in literature that the ‘fast track’ land reform policy shift contributed the loss in area planted owing to the stalling of farming operations due to political unrest, economic instability and input shortages were supported by the model results which showed that total area harvested would have been higher under pre-2000 conditions. From the re-simulated baseline results, the difference between actual and would be outcomes revealed that the total maize production was 13.27% less than what could have been produced in 2001, the year that the ‘fast track’ land reform policy was formally implemented. In view of the 2002/03 drought, output was 57.44% less and 33.53% less than what could have actually been produced for the 2002 and 2003 seasons respectively. In the 2005 drought season, the total maize production was 41.8% less than what could have been produced without the ‘fast track’ land reform. This may imply that droughts would have been less severe if the ‘fast track’ land reform was not implemented. In 2007, the baseline showed that the nation could have produced almost 48.03% more than what was actually produced. Therefore, according to the model results, the assertion that the ‘fast track’ land reform contributed, to a fair extent, to the underperformance of the maize sector still holds. The model developed in this dissertation contributes to an understanding of not only the general structure of the maize market, but also of the impact of the ‘fast track’ land reform policy on the Zimbabwean maize market based on how the market itself could have performed under the absence of these land reforms. The baseline model revealed that the maize sector performed below potential within the period of the ‘fast track’ land reform. The maize market model could thus be used as a tool that may assist policymakers to design future strategies that will help enhance maize sector performance. / Dissertation (MSc(Agric))--University of Pretoria, 2010. / Agricultural Economics, Extension and Rural Development / unrestricted

The purpose of this study was to explore the subjective experiences of participants who had completed a fast-track management development programme (FMPD) for hospital managers. The participants in this study were part of a targeted or single-identity group FMDP in a private hospital group in South Africa. Single-identity group management development programmes target women and minorities, and are designed to equip them to fulfil more senior roles. These programmes were introduced by some South African companies in response to the Employment Act 55 of 1998 to ensure that all population groups are represented across occupational levels, including senior management. This study sought to gain insight of the participants’ perceptions of the programme and its effectiveness. Qualitative, semi-structured interviews were conducted with the participants. The sample consisted of six managers (four men and two women). The developer of the programme was also interviewed. The findings indicate that all of the participants believed there is a need for these types of programmes because of South Africa’s history. However, the interviews also surfaced concerns about the structure of the programme and the stigmatisation associated with being in a single-identity programme. The results suggest a number of theoretical and practical implications for the use of single-identity management development programmes. / Dissertation (MCom)--University of Pretoria, 2012. / Human Resource Management / unrestricted

O presente estudo teve por objetivo caracterizar em atletas homens e mulheres a dinâmica do stiffness e dos parâmetros biomecânicos atrelados ao stiffness (PBAS) durante uma corrida de elevada velocidade e curta duração. Ainda, investigar possíveis discriminantes de desempenho da corrida, e a relação destes com as tarefas de salto frequentemente utilizados nos treinamentos. Para tanto, foram realizados 2 estudos, sendo que o estudo 1 caracterizou a dinâmica dos parâmetros biomecânicos atrelados ao stiffness e apontou possíveis discriminantes de desempenho (por gênero), e no estudo 2 relacionou-se estes possíveis discriminantes com as tarefas de salto. O \"Spring Mass Model\" foi utilizado para obtenção dos PBAS, ao ponto que plataformas de força (AMTI) e a cinemetria (VICON) foram utilizados para a aquisição dos dados de salto. Foi evidenciado que o stiffness não apresentou total convergência com a dinâmica da velocidade apresentada no teste de corrida de elevada velocidade e curta duração, e que a força vertical aplicada ao solo durante a fase de apoio foi o PBAS que mais se aproximou da dinâmica apresentada pela velocidade. Não houveram distinções entre os gêneros na dinâmica do stiffness e dos PBAS, porém o gênero feminino apresentou maior dependência de parâmetros temporais de passo no início do teste e complacência muscular no final do teste, e o gênero masculino maior dependência de parâmetros atrelados a incremento de força no início do teste e incremento da fase aérea no final do teste. Ainda, houve diferença com significância estatística entre os gêneros quanto à magnitude e contribuição das fases da corrida. No mais, o salto horizontal (SH) apresentou maior relação com o desempenho em ambos os gêneros. Desta forma, conclui-se que 1) o stiffness propriamente dito não pode explicar o desempenho em uma corrida de elevada velocidade e curta duração, 2) dentre os PBAS, a magnitude da força vertical aplicada ao solo durante a fase de apoio apresentou maior proximidade com a dinâmica da velocidade, 3) homens e mulheres dependem distintamente dos PBAS para melhora no desempenho na corrida, e 4) o SH é meio de maior validade ecológica a ser utilizado nas rotinas de avaliação e treinamento de atletas envolvidos em provas de elevada velocidade e curta duração / The present study aims to characterize the dynamics of stiffness and biomechanical parameters related to stiffness (BPRS) in male and female athletes during top speed short distance run. It also intends to investigate possible performance discriminative factors and their relation with jumping tasks frequently used in training. For this purpose, two studies have been developed. Study 1 has characterized the dynamics of the biomechanical parameters related to stiffness and indicated possible discriminative factors (by gender). The study 2 has related these possible discriminative factors with jumping. The \'Spring Mass Model\' has been used to obtain the BRPS and the force plate (AMTI) and cinemetry (VICON) have been used to acquire jumping data. The study showed that stiffness has not presented total convergence with velocity dynamics and the vertical force applied to the ground during the support phase has been the closest result to the velocity dynamics presented. There has not been distinctions regarding gender in stiffness and BRPS dynamics, however, females have showed more dependency on step timing parameters on the test beginning and muscle complacency at the end of the test; and males presented more dependency on to the vertical force applied to the ground during the support phase on the test beginning and parameters connected to the increase in the swing phase at the end test. Moreover, there has been a difference with statistical significance between genders regarding magnitude and contribution through the running phases. In additional, the horizontal jump (HJ) results represented a closer relation to the performance top speed short distance run. Therefore, it has been concluded that 1) stiffness itself cannot explain the performance in top speed short distance run, 2) among the BRPS, vertical force magnitude applied to the ground during support phase presents closer results to velocity dynamics, 3) males and females depend on distinct BRPS to enrich their performance and 4) HJ is the exercise with the major validity to be used for the evaluation and training routine of top speed short distance run athletes

Magister Artium (Sport, Recreation and Exercise Science) - MA(SRES) / In swimming, a swimmer’s performance is mostly determined by the time spent on starts, stroking and turning. The start of a swimming races, especially sprint races, can account for almost a quarter of race time

Doctor Educationis / Background: In swimming, a swimmer’s performance is mostly determined by the time spent on starts, stroking and turning. The start of a swimming races, especially sprint races, can account for almost a quarter of race time. Aim: The aim of this study was to analyse the biomechanics and performance of three start techniques off the OSB11 starting platform over 15-meters to determine which of the three is most effective when looking at the three parts that constitute the start: block time, flight time and underwater time. Methods: A Quasi-experimental cross over trial-based study design was used to determine which of three starting techniques (Grab, Track & Kick) was the most effective off the OSB11 starting block. Ten Swimmers who qualified for junior nationals from Vineyard Swimming Club participated in the study. Each participant acted as their own control and were required to perform each start once. All trials were filmed and analysed on Dartfish pro suite 10. The following variables were analysed: shoulder angle, hip angle, knee angle, reaction time, movement time, total block time, flight distance, flight time, flight velocity, entry angle, underwater time, underwater distance, time to 15-meters.