Analysis of saprolite-hosted Rutile-Graphite deposit: a case study of Malingunde saprolite-hosted Rutile-Graphite project in Central Malawi
- Authors: Zabula, Ansel Aliko
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/464970 , vital:76562
- Description: The Malingunde graphite project, owned by Sovereign Metals Ltd (SML), has revealed significant potential for rutile and high-grade graphite in saprolite. This study addresses the complexity of mineral assemblages in the Malingunde area, emphasizing the coexistence of graphite and rutile. SML's exploration activities, including extensive drilling and soil sampling, have uncovered variations in associated minerals, such as muscovite, kyanite, garnets, and ilmenite. Rutile, initially discovered incidentally, has prompted further investigation, impacting the financial model of the project. This research aims to analyse the Malingunde deposit, focusing on understanding its mineralogy, formation, and potential for elements like vanadium. Geological surveys reveal the distribution of graphite in the Precambrian to lower Palaeozoic age basement complex, hosted in saprolite resulting from tropical weathering of graphitic gneisses. Exploration techniques, including remote sensing, and geophysics, are crucial in targeting graphite and rutile deposits. Ground electromagnetic surveys, airborne electromagnetic data, and GIS applications aid in identifying and quantifying mineralised areas. Geochemical analysis and metallurgical tests further contribute to understanding the ore body and processing methods. Results indicate an inverse relationship between graphite and rutile concentrations, influencing the economic viability of different regions within the project area. Correlation matrices and regression analyses reveal distinct geological conditions influencing the association of vanadium and graphite in Lifidzi and Malingunde. The study concludes with exploration potential outside the Malingunde project, highlighting regional prospects and potential byproducts like vanadium pentoxide. The ongoing metallurgical tests and pilot plant design signify the project's evolution toward production. Additionally, neighbouring licenses show potential, emphasizing the need for comprehensive research to define and quantify resources in the region. This research provides valuable insights for the mining industry, informing strategies for exploration, resource assessment, and potential byproduct utilization in similar geological settings. , Thesis (MSc) -- Faculty of Science, Geology, 2024
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- Date Issued: 2024-10-11
Application of SWAT+ model to assess the hydrology of irrigated agricultural catchments in Western Cape, South Africa
- Authors: Mabohlo, Sakikhaya
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/464986 , vital:76563
- Description: Agricultural activities can modify hydrological processes in catchments. An in-depth investigation of the impact of agriculture on hydrological processes is thus crucial for sustainable water management and utilisation planning in agricultural catchments. Hydrological models are widely used as practical tools to estimate and understand hydrological processes at various scales in catchments. However, it is often challenging to represent hydrological processes accurately in agriculture-dominated areas due to their complexity and the structural inadequacy of models. Complexities driven by agricultural developments such as reservoirs, cultivation irrigation, and water transfers are often intricate and difficult to represent in detail. The current study applied the SWAT+ hydrological model to the agriculture-dominated Twee and Leeu catchments in the Western Cape Province of South Africa. The SWAT+ model was preferred because it is versatile in representing multiple reservoirs and irrigation from multiple sources. The model application aimed to enhance the understanding of hydrological processes and the impact of agricultural water use on catchment hydrology, explore the capabilities and performance of this relatively new version of the SWAT in a complex catchment and provide baseline hydrology input for systems models that were used to formulate a water management plan for the catchment. The SWAT+ model was able to represent the significant number of reservoirs in the catchment. In some cases, small farm dams had to be lumped together to deal with the model's structural inadequacy. The model performed well in terms of observed and simulated streamflow comparison. NSE and R2 values above the standard of 0.5 were obtained for both catchments. Moreover, an NSE of 0.7 at a daily time-step simulation was obtained for the Leeu Catchment validation period, indicating a generally impressive SWAT+ performance. The model indicated that hydrological processes in the area were largely dominated by evapotranspiration, which is expected of semi-arid regions. 55% of the total water input into the Twee quaternary catchment is lost through evapotranspiration, while 22% is converted into surface runoff. Interflow and groundwater flow account for 9% and 9% of the catchment water, respectively. The remaining 5% is distributed to soil moisture and groundwater storage. For the Leeu, the model simulated a loss of 67% of the precipitation through evapotranspiration. Interflow and surface runoff were estimated to be 25% and 24%, respectively. Groundwater contribution to the stream accounts for 7%. Therefore, evapotranspiration and surface runoff are the dominant processes from a water balance perspective, whereas groundwater flow is also significant. Agricultural activities impacted the hydrological system significantly, and this is mainly attributed to the construction of numerous reservoirs and the subsequent intensive irrigation in the dry summer periods. The model simulation revealed that the reservoir and irrigation reduced the annual average streamflow by 71% in the Twee Catchment. In the Leeu Catchment, reservoirs and irrigation resulted in an annual average streamflow reduction of 77%. Therefore, agriculture has significantly altered flow patterns in the catchment, particularly downstream areas, during drier years. In conclusion, understanding of hydrological processes, reservoir and irrigation impact on catchment flow dynamics are the key outcomes that support decision-making regarding sustainable water management and utilisation planning. The broader outcomes, including spatially distributed flows and irrigation demand for different crop types, were used as baseline inputs for systems models that explored various water management options. SWAT+ thus played a crucial role in developing a water management plan for the area. Although the model exhibited some structural deficiencies in representing some catchment complexities, it fairly represented and enhanced our understanding of the hydrological dynamics of the Twee and Leeu Catchments. Additionally, the model has proven to be a versatile tool that can be applied for practical catchment water management in the agriculture-dominated catchments of South Africa. , Thesis (MSc) -- Faculty of Science, Institute for Water Research, 2024
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- Date Issued: 2024-10-11
Aspects of the sustainability of the wild honeybush industry
- Authors: McGregor, Gillian Kathleen
- Date: 2024-10-11
- Subjects: Cyclopia intermedia , Renewable natural resources South Africa , Sustainability , Local ecological knowledge , Harvesting
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/464266 , vital:76493 , DOI 10.21504/10962/464266
- Description: Honeybush products are uniquely South African, derived from plants of the fynbos genus, Cyclopia. Cyclopia intermedia is the most widespread species, distributed across 11 496 km2 of the Cape Fold Mountains, and provided the bulk of supply for the industry until 2022. While the industry is small, it is a locally significant industry affecting the livelihoods of harvesters, farmers and processors in the greater Langkloof region of the Eastern and Western Cape provinces of South Africa. The industry has evolved from a cottage one, to a commercial scale, and concerns have been raised over the sustainability of the wild resource specifically, and the industry in general. The research aimed to improve our understanding of aspects of the sustainability of the wild honeybush industry. A mixed methods design was adopted, which allowed for the inclusion of data collection approaches and analysis which tell a richer story than one with a singular modus. Four objectives were identified, which entailed: (i) mapping the resource to establish the distribution range of C. intermedia; (ii) recording of local ecological knowledge (LEK) and traditional ecological knowledge (TEK) around best practice harvesting; (iii) assessing the sustainability of harvest enterprise types through analysis of yield history and harvester loads; (iv) identifying differences between harvested and unharvested C. intermedia populations. Mapping of the resource drew on a variety of existing data sources, field mapping, GIS-based analysis, species distribution modelling and expert mapping to create a comprehensive and accurate map of the species distribution. The species is estimated to occupy a distribution range of 11 496 km2, 49% of which occurs in formally protected areas. Based on local scale mapping by experts, 100km2 is estimated to be in use for wild harvesting in the production area of the Langkloof. Information on best practice harvesting was collected through in-depth interviews with harvesters, harvest managers, processors and farmers (in the field at harvest events) and through questionnaire surveys and focus group discussions at a honeybush stakeholder workshop. In combination with harvest event surveys at which harvester practice was observed and recorded, and surveys were conducted of the harvest yield and of plants in the harvested population, the information was used to produce the first formal account of best practice for sustainable harvesting of wild honeybush. To assess the sustainability of harvest enterprises and associated harvester livelihoods, harvester managers were interviewed to create profiles of typical harvesting enterprises based on their practices and harvest yield histories. Of the three harvest enterprises considered, two showed sustained yields over time, while those of a large contract type enterprise were less sustainable with declining yields on three out of six farms. From a statistical analysis of the records it was found that the most effective team size was 10 or less harvesters in terms of livelihood sustainability. They could earn a fair livelihood (ZAR67 680.00) per annum, based on a 94 kg load per daily harvest event, sold to the processor at ZAR 5.00, for nine months of the year, working a four-day week. For a team to operate sustainably, it was found that it should consist of experienced harvesters harvesting conservatively, at intervals of at least four years, and be responsive to local environmental conditions. Detailed field surveys of C. intermedia plants at 38 sites representing harvested and unharvested populations were carried out to understand the impact of harvesting on the plants. A statistical analysis of the plant's dimensions related to the physical environment, fire and harvest history using generalised linear models revealed that while unharvested plants were slightly larger, only crown diameter and stem counts were significantly so. Seedlings were noticeably scarce at all sites, including recently burnt sites. A significant finding of the research was that in a fecundity survey, unharvested plants produced significantly more pods. The impact of this is unknown, but it has implications for management and the sustainable use of wild resources in the long term. Further understanding of the impact of harvesting came from surveys of cultivated stands of C. intermedia (different ages and harvest histories, but all harvested at three-year intervals) and surveys of a wild population, which was subjected to unregulated harvesting. For the cultivated stand: after 12 years, plants declined in all measured dimensions, while in the wild population, 45% of the plants died over a seven-year period. The surveys proved that a three-year interval or frequent, unregulated harvest is unsustainable. The research was used to produce the wild harvesting guidelines, which have become the accepted standard for the industry. It has demonstrated that under the right circumstances, harvesting of the wild C. intermedia resource is broadly sustainable. However, there needs to be informed management of the use of the resource in terms of harvest team types and their protocols, particularly with regard to harvest intervals and possible interventions to improve seed production to achieve sustainable use of the resource in social, economic and ecological terms. , Thesis (PhD) -- Faculty of Science, Geography, 2024
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- Date Issued: 2024-10-11
Aspects of the water use of Cannabis sativa L. under dryland cultivation in the Eastern Cape
- Authors: Zenani, Kamva Trevor Songo
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/465035 , vital:76567
- Description: Cannabis spp is one of the oldest cultivated plants, with its origin in Asia. It has two species, namely C. indica and C. sativa. This research focuses on C. sativa, which is widely cultivated locally and globally. C. sativa has a wide range of uses, including industrial, medicinal, religious, and recreational. This study will be focusing on the water use of medicinal and recreational C. sativa grown under dryland conditions. In recent years, there has been a growing interest in increasing its cultivation, but there are reports of it having high water usage. The global interest has led many governments to review the laws governing this plant as it is a controlled substance in many countries. Due to its legal status, there is a dearth of knowledge about its growth and water use. It is against this backdrop that the Water Research Commission (WRC) commissioned this study into the water use of this plant. This will provide evidence-based support for the issuing of water use licenses by the Department of Water and Sanitation. The Eastern Cape and KwaZulu Natal have many small-scale legacy farmers who have been growing C. sativa illegally for decades. The findings of this research will seek to fill some of these knowledge gaps and assist legacy farmers in the cultivation of this plant. This research had four approaches, which include 1) planting the crop in a dryland location that will mimic the conditions experienced by legacy growers, 2) the collection of plant biophysical variables in the study site in order to gain a better understanding of the plant’s health, growth, progress, and to use these variables to parameterize a mechanistic eco-physiological model, 3) the installing of a large aperture scintillometer (LAS) together with a micro-meteorological station to measure the evapotranspiration (ET) and meteorological parameters over a crop cycle, 4) to use MEDRUSH evapotranspiration model to predict the ET and compare these results against that of the LAS. The results show that water provision had a significant impact on plant biophysical variables and water use. The plants received 154 mm (2 mm day-1) of rain during the crop cycle. The large aperture scintillometer recorded a total ET of 126.8 mm (1.76 mm day-1) during the same period. The MEDRUSH model (2.5 mm day-1) overestimated the LAS ET (1.79 mm day-1), and the results from the daily ET revealed that C. sativa had higher daily ET when compared to the local grass Eragrostis plana. These results confirm that at this location in the Eastern Cape, C. sativa requires regular irrigation during the growing season to grow and secure a crop. , Thesis (MSc) -- Faculty of Science, Institute for Water Research, 2024
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- Date Issued: 2024-10-11
Bio-vectoring by honeybees and symbiosis: a combined approach to controlling Botrytis mould on strawberry
- Authors: Starbuck, Megan
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/463985 , vital:76463
- Description: Access restricted. Exxpected release in 2026. , Thesis (MSc) -- Faculty of Science, Biochemistry, Microbiology & Bioinformatics, 2024
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- Date Issued: 2024-10-11
Burgernomics: Raw BMI vs Adjusted BMI. A comparative analysis of appropriate exchange rate valuation measures
- Authors: Gumedze, Siyanda Nakiwe Nomfundo
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/462702 , vital:76327
- Description: The Big Mac Index was developed in 1986 by The Economist magazine as a playful take on the Purchasing Power Parity theory. Its purpose is to indicate whether a currency is overpriced or undervalued in relation to the real exchange rate and whether it can be used as a reliable indicator of exchange rate predictions. There are two versions of the Big Mac Index: the raw Big Mac Index and the adjusted Big Mac Index. If appropriate, this index might be developed into an economic theory that can be applied to corporate finance, international trade, and international finance. To determine which Big Mac Index measure is a better indicator of exchange rate valuation, a comparison analysis was conducted. This study set out to determine how well the adjusted Big Mac Index performed as a gauge for exchange rate valuation. The research then compares the two Big Mac Index measures' ability to anticipate future exchange rates in order to determine which is more accurate. Data from the South African Reserve Bank and The Economist databases covering 37 nations from 2000 to 2022 were used for the analysis. Exchange rate misalignment trends were assessed globally, and the results indicated that the adjusted BMI was a more accurate measure of purchasing power. Tests of correlation revealed that there was a positive association between the real exchange rate and the Big Mac Index. Findings from a panel ARDL Model indicated that taking into consideration country-specific GDP variations and group heterogeneity can enhance the real exchange rates' ability to predict the raw BMI. The research also focused on the South African Rand to ascertain whether the Big Mac Index validates the Purchasing Power Parity theoretical framework. Using cointegration tests and graphic analysis, it was possible to find evidence for a cointegrating relationship between the real exchange rate and the Big Mac Index measures during the last 20 years. Additionally, a positive correlation between the modified Big Mac Index and terms of trade was discovered in the results, confirming the hypothesis that the Big Mac Index satisfies current account assumptions. Finally, a VEC model demonstrated that the modified BMI outperforms the raw BMI in terms of forecasting estimates. Overall, the study found that the Big Mac Index is more than a bit of fun as per its origin. The results showed that the adjusted Big Mac Index has practical applications and the potential to be considered as an economic theory. , Thesis (MCom) -- Faculty of Commerce, Economics and Economic History, 2024
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- Date Issued: 2024-10-11
Carbonylation of cyclohexene with carbon dioxide (CO2) using transition metals as heterogeneous and homogeneous catalysts
- Authors: Sekaleli, Bafokeng Thabelo
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/464565 , vital:76522
- Description: From a green chemistry perspective, carbon dioxide (CO2) emerges as an appealing C1 synthon, given its abundance in the atmosphere and cost-effectiveness. Many essential chemicals for daily life are derived from fossilized carbon sources like coal, petroleum, and natural gas. However, the by-product of these processes, CO2, poses environmental risks when excessively emitted as a greenhouse gas. Achieving a balance between carbon emissions and removal is crucial to address environmental concerns surrounding CO2. Utilizing CO2 as a C1 source in organic synthesis holds promise for mitigating this balance in the long term. Combining CO2 with other underutilized fine chemicals, such as alkanes, alkenes, and alkynes, to produce more valuable platform chemicals presents an economically viable strategy due to carbon dioxide’s abundance, low cost, and recyclability. Despite its simplicity, CO2's high thermodynamic stability and low kinetic reactivity, owing to its highly oxidized state, pose challenges to its use as a feedstock. Overcoming these hurdles requires catalysts to enhance CO2 reactivity. Our work focuses on developing and employing catalytic systems capable of activating CO2 as a C1 synthon in reactions with cyclohexene and a reducing agent to yield carboxylic acids or esters. In one approach, we have developed heterogeneous catalyst systems comprising transition metals (Au, Fe, Ni, Ru) supported on metal oxide (TiO2). Characterization techniques such as TEM, EDX, UV-Vis, BET, and XRD were used to study the properties of these materials. The catalysts were evaluated in a reaction involving cyclohexene, CO2, and H2O. In another approach, we explored the use of cyclo-tris(tetracarbonylruthenium) [Ru3(CO)12] as a homogeneous catalyst in a reaction involving cyclohexene, methanol, and CO2 in the presence of an ionic liquid, 1-Butyl-3-methylimidazolium chloride ([BMIM]+Cl-). 1H NMR and ATR-FT-IR were utilized to characterize [BMIM]+Cl-. The reaction product was characterised utilizing GC-MS. Upon seeing that Ru3(CO)12 changes color from orange to black when exposed to heat, an investigation was undertaken on the kind of transformations that the catalyst undergoes. This investigation was carried out with the hopes of finding the structures that could be resulting from Ru3(CO)12 during the reaction and their significance to it. The orange and black Ru complexes were characterized utilizing DSC, TGA, ATR-FT-IR and PXRD. , Thesis (MSc) -- Faculty of Science, Chemistry, 2024
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- Date Issued: 2024-10-11
Carnivory submerged: aspects of the ecology and ecophysiology of the aquatic Utricularia stellaris L. fil. (Lentibulariaceae) in South Africa
- Authors: Marais, Alice-Jane
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/464473 , vital:76514
- Description: The trapping structures produced by aquatic species of Utricularia have traditionally been interpreted to function as adaptations to capture and break down zooplankton prey, as in other carnivorous plants, to overcome nutrient limitations. However, an increasing number of studies have found that these plants may also rely on benefits derived from living mutualistic microbial communities contained within traps. This study documents aspects of the environmental, growth and physiological characteristics of U. stellaris to inform and to form a basis for future investigation into the plant-microbe interaction. The environmental conditions in which U. stellaris grows were documented to identify potential adverse conditions plants are subject to in situ, from which nutrient limitation was identified as a primary limitation. Plant growth and trapping structures were then assessed to identify possible adaptations of plants to overcome these limitations. The production of trapping structures likely constitutes an adaptive trait, with 30% of total biomass per node allocated to the production of these structures. Based on their capture function, traps may aid plants based on their contents, possibly supplementing plants with nutrients. Although assessments of the habitats of U. stellaris indicate that dissolved CO₂ concentrations in the ambient water are high, CO₂ may still be limiting to the photosynthetic rates of these plants due to viscous water resisting the diffusion of CO₂. The primary site of photosynthesis in U. stellaris is leaves and trap tissue’s contribution to photosynthetic output is negligible. U. stellaris plants are subject to CO₂ limitations in natural pond conditions, making the substantial allocation of resources to non-photosynthetic trapping tissue even more costly. Therefore, benefits gained from trapping structures are likely to be derived from trap contents; having ruled out the possibility that the trap tissue itself is photosynthetic. Trap contents of U. stellaris were assessed. The proportion of traps containing living microbial communities greatly exceeded the proportion containing zooplankton prey. In addition, these communities were found to be diverse, stable, and self-sustaining. These results suggest that trapping structures may be beneficial for both the carnivorous capture of prey and the housing of living microbial communities. These results indicate the plantmicrobe interaction in U. stellaris warrants further study. , Thesis (MSc) -- Faculty of Science, Botany, 2024
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- Date Issued: 2024-10-11
Characterisation, and remote sensing exploration potential, of a hydrothermally mineralised Diorite, Chris Hani district, Eastern Cape, South Africa
- Authors: Johnstone, Shawn Douglas
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/464930 , vital:76558
- Description: Access restricted. Expected release in 2026. , Thesis (MSc) -- Faculty of Science, Geology, 2024
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- Date Issued: 2024-10-11
Co-crystal formation of pharmaceutical and veterinary tranquilizer molecules
- Authors: Mngwengwe, Bongeka Naledi Precious
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/464532 , vital:76519
- Description: Midazolam, a 1,4-benzodiazepine derivative is commonly used to treat anxiety, insomnia and may be used as a sedative in anaesthesia as it has calming, anti-convulsant and muscle relaxant properties. Midazolam has a rapid onset but a short duration of action resulting in fewer adverse effects. Midazolam also has the potential to form insoluble crystalline precipitates in pharmaceutical dosage forms such as syrups and solutions, which is a challenge in formulation and process development activities. The primary goal of this research was to prepare multicomponent crystals of midazolam free base, specifically targeting interactions with coformers structurally similar to methyl paraben. Key preparation techniques included neat grinding, liquid-assisted grinding, and slow evaporation. The resulting solid forms were characterized using Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), and powder X-Ray Diffraction (PXRD). In addition, Single-Crystal X-Ray Diffraction (SCXRD) was used to elucidate detailed structural information on the novel multicomponent crystals formed. Successful preparation of midazolam free base from the hydrochloride salt was confirmed through FTIR, DSC, and PXRD analysis. Different co-crystals and salts of midazolam with coformers such as salicylic acid (SA), benzoic acid (BA), 3-hydroxybenzoic acid (3-HBA) and p-aminobenzoic acid (PABA) were synthesized and characterized. The structure of the single crystal obtained from a veterinary tranquilizer solution was solved and found to be a salt that had formed between midazolam free base, midazolam HCl, and methyl paraben. This finding inspired further investigation of similar multicomponent crystals of midazolam and methyl paraben analogues. This study demonstrated the effectiveness of both mechanochemical and slow evaporation methods for the preparation of multicomponent crystals. PXRD and DSC provided insights into the stability and purity of the crystals that had formed and the differences in melting points and PXRD patterns were particularly important in this regard. Differences in FTIR spectra were used to distinguish between different solid forms and to confirm the successful formation of new solid forms. Extensive searches in the Cambridge Structural Database (CSD) confirmed that the multicomponent crystals of midazolam, such as MDZ‧SA, MDZ‧BA, MDZ‧3-HBA, and MDZ‧PABA, had not previously been reported, highlighting the novelty of these findings. The research successfully isolated and characterized several novel multicomponent crystals of midazolam, demonstrating the potential of mechanochemistry and solvent evaporation techniques in the development of pharmaceutical and veterinary medicinal applications. These findings contribute to the understanding of cocrystal formation and provide a foundation for future studies in which the stability and efficacy of midazolam-based formulations can be evaluated. , Thesis (MSc) -- Faculty of Science, Chemistry, 2024
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- Date Issued: 2024-10-11
Co-management and social equity at Silaka and Hluleka Nature Reserves, South Africa
- Authors: Mtshintsho, Anda
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/464834 , vital:76549
- Description: Co-management of protected areas (PAs) is a desired conservation approach aimed at balancing ecological goals and livelihood needs. Central to co-management are issues related to power sharing, responsibilities and benefit sharing. However, there still remains a dominance of an ecological emphasis in PA management, with studies focusing more on ‘objective’ biodiversity indicators for measuring the effectiveness of protected areas. However, focusing only on ecological indicators addresses a narrow perspective of achieving ecological integrity and misses social dimensions that, in some cases, might be considered more important than technical considerations. Particularly, in contexts with a history of socio-physical displacement of Indigenous people and local communities (IPLC), the social dimensions of wellbeing are complexly embedded into the economic and ecological dimensions, such that ignoring these linkages might jeopardise the success of protected areas. Thus, the aim of this study was to examine the state of research and conceptual advances on social indicators of conservation success in co-managed PAs and stakeholder views and perceptions on socially just conservation in co-managed protected areas in Silaka and Hluleka Nature Reserves, South Africa. To achieve this, a scoping review, semi-structured interviews and futures workshops (using the three horizons framework) were conducted. Findings from the scoping review (chapter 2) revealed that much of the reported social monitoring indicators still rely on quantifiable metrics (i.e., economic benefits) and less on subjective and relational metrics (i.e., qualitative strength of social networks and perceptions). Unsurprisingly, many of the reviewed case studies revealed the use of participation as an indicator of evaluating co-management success. Further, the interviews and futures workshop results in chapter 3 showed that the non-accrual of key co-management expectations such as the employment of local people, benefit-sharing (material or otherwise), participation in decision-making and community development has led to heightened conflicts between the reserve management agency and local people. Consequently, the respondents did not value the co-management arrangements, citing unfulfilled promises. Broadly, the findings of this study emphasise the need for collective and collaborative efforts in developing indicators that are not only socially just but those that are context dependent and sensitive. , Thesis (MSc) -- Faculty of Science, Environmental Science, 2024
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- Date Issued: 2024-10-11
Cocrystals, salts and eutectics of anti-tuberculosis medicines
- Authors: Matlapeng, Tsebang Alice
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/464521 , vital:76518
- Description: Tuberculosis remains as a prominent cause of death worldwide. This infectious disease is treated with first and second line drugs. However, challenges of multi drug resistant tuberculosis and adverse side effects such as depletion of essential B group vitamins in the body by first line drugs, as well as poor physicochemical properties of second line drugs persist. Cocrystallisation of anti-tubercular drugs with various coformers has therefore been used as an alternative method to improve the physicochemical properties of active pharmaceutical ingredients (API) while maintaining their efficacy. The main objective of this study was to carry out cocrystal screening of anti-tubercular API and vitamin B coformers to make drug-drug or drug-vitamin multicomponent complexes. Preparation of the multicomponent complexes was carried out by mechanochemical grinding (neat grinding (NG), liquid assisted grinding (LAG) and slow evaporation. All complexes were characterised using Fourier-transform infrared spectroscopy (FTIR), powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and crystal structures were elucidated using single-crystal X-ray diffraction (SCXRD). The cocrystal screening resulted in the formation of various solid forms, which included cocrystals, salts and eutectic products. Two cocrystals of 4-aminosalicylic acid (PAS) were isolated and characterised. The cocrystal of PAS with isoniazid (INH) demonstrated similar characteristics for both the bulk crystalline material and milled materials. The cocrystal of PAS and pyrazinamide (PYR) prepared using mechanochemical synthesis was met with challenges, while difficulties were also encountered in obtaining suitable crystals for SCXRD analysis. The ground and recrystallised samples of the PAS and pyrazinecarboxylic acid (PCBA) showed distinct differences in their thermal behaviour, with SCXRD revealing the decomposition product phenolammonium-pyrazinecarboxylate salt ‘sans’ the CO2 moiety. Salt formation involving pyridoxine (PN) yielded a salt hydrate with PAS (PN-PAS) and an anhydrous salt with PCBA (PN-PCBA). Both salts exhibited very complex packing arrangements with equally complex thermal behaviour depending on the solvent used during preparation, and the method of preparation. Three eutectic systems involving INH with PYR, PN and pyridoxine hydrochloride (PNꞏHCl) were identified, and their phase diagrams were constructed from DSC data. The eutectic compositions obtained were 1:1 for INH:PYR, 1:1 for INH:PN and 6:4 for INH:PNꞏHCl. Finally, a total of eight multicomponent complexes were prepared using selected API and vitamin B6 components. The results presented here provide motivation for further investigation and evaluation of the pharmacochemical properties of these API. , Thesis (MSc) -- Faculty of Science, Chemistry, 2024
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- Date Issued: 2024-10-11
Comparative analysis of YOLOV5 and YOLOV8 for automated fish detection and classification in underwater environments
- Authors: Kuhlane, Luxolo
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/464333 , vital:76502
- Description: The application of traditional manual techniques for fish detection and classification faces significant challenges, primarily stemming from their labour-intensive nature and limited scalability. Automating these kinds of processes through computer vision practices and machine learning techniques has emerged as a potential solution in recent years. With the development of and increase in ease of access to new technology in recent years, the use of a deep learning object detector known as YOLO (You Only Look Once) in the detection and classification of fish has steadily become notably popular. This thesis thus explores suitable YOLO architectures for detecting and classifying fish. The YOLOv5 and YOLOv8 models were evaluated explicitly for detecting and classifying fish in underwater environments. The selection of these models was based on a literature review highlighting their success in similar applications but remains largely understudied in underwater environments. Therefore, the effectiveness of these models was evaluated through comprehensive experimentation on collected and publicly available underwater fish datasets. In collaboration with the South African Institute of Biodiversity (SAIAB), five datasets were collected and manually annotated for labels for supervised machine learning. Moreover, two publicly available datasets were sourced for comparison to the literature. Furthermore, after determining that the smallest YOLO architectures are better suited to these imbalanced datasets, hyperparameter tuning tailored the models to the characteristics of the various underwater environments used in the research. The popular DeepFish dataset was evaluated to establish a baseline and feasibility of these models in the understudied domain. The results demonstrated high detection accuracy for both YOLOv5 and YOLOv8. However, YOLOv8 outperformed YOLOv5, achieving 97.43% accuracy compared to 94.53%. After experiments on seven datasets, trends revealed YOLOv8’s enhanced generalisation accuracy due to architectural improvements, particularly in detecting smaller fish. Overall, YOLOv8 demonstrated that it is the better fish detection and classification model on diverse data. , Thesis (MSc) -- Faculty of Science, Computer Science, 2024
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- Date Issued: 2024-10-11
Computational search for nature-derived dual-action inhibitors of HIV-1 reverse transcriptase and integrase: a potential strategy to mitigate drug resistance progression
- Authors: Mwiinga, Luyando
- Date: 2024-10-11
- Subjects: HIV (Viruses) , Reverse transcriptase , Antiretroviral agents , RDKit , Drug resistance , Docking
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/463930 , vital:76458
- Description: Human immunodeficiency virus Type 1 (HIV-1) is a devastating viral infection affecting millions worldwide and presents significant challenges in treatment and management. In 2022, approximately 39 million people were living with HIV with Sub-Saharan Africa having two thirds of these infections. Devastatingly, there were approximately 300 000 HIV/AIDS related deaths in Sub-Saharan Africa alone in 2022 alone. Antiretroviral therapy (ART) which is fundamental for HIV treatment, comprises of a combination of drugs such as nucleoside reverse transcriptase inhibitors (NRTIs), non-nucleoside reverse transcriptase inhibitors (NNRTs), protease inhibitors (PIs) and integrase strand transfer inhibitors (INSTIs). However, although 28.7 million people out of the estimated 38.4 million people living with HIV in 2021 were receiving ART, the emergence of drug-resistant strains further complicates treatment efforts, highlighting the need for novel therapeutic approaches. This study aimed to address the challenges raised by drug resistance and significant side effects by identifying potential dual inhibitors against HIV-1 Reverse Transcriptase (RT) and Integrase (IN) using in silico techniques. RT RNase H and IN were chosen as targets for their shared dependency on Mg2+ ions within their active sites, which are crucial for catalytic activity. The selection of dual inhibitors was motivated by the fact that the virus would need to replicate at two points simultaneously to develop resistance, making it less likely. The objectives of this study included the creation of a natural derivative compound library using RDKit with the aid of SciFinder, utilizing (-)-epigallocatechin-3-O-gallate (EGCG), because of its dual inhibitory effects against RT and IN, as indicated by a study conducted by Sanna et al. 2019. The natural derivatives were chosen to take advantage of their chemical diversity and to explore potential novel therapeutic options for combating HIV drug resistance. The compound library created comprised of 125 203 compounds. Then docking studies were conducted to assess proteinligand binding. After the correlation of the RT and IN docking studies, 288 compounds were filtered to have potential dual inhibitory activity. Then quantitative estimation of druggability (QED) analysis identified three compounds with superior properties compared to EGCG and FDAapproved drug raltegravir (RAL). Molecular docking simulations revealed interactions between the inhibitors and the key active site residues of RT and IN, along with the chelation of at least one 3 Mg2+, suggesting the potential for enzymatic disruption. Furthermore, molecular dynamic (MD) simulations were then conducted to assess protein-ligand system behavior, through RMSD and RMSF analysis. The RMSD analysis uncovered instability in the IN-Sci30703 complex, leading to its exclusion as a potential dual action inhibitor. RMSF analysis for IN showed that all the inhibitors had the ability to limit the flexibility of the catalytic loop which is essential for catalytic activity. Therefore, further in vitro studies are required to evaluate the effectiveness of the remaining two EGCG derivatives (Sci33211 and Sci48919) in inhibiting RT and IN through the chelation of at least one Mg2+ ion to determine if they have superior dual inhibitory effects compared to EGCG. This study adds to the ongoing efforts to develop effective strategies against HIV-1 drug resistance and emphasizes the importance of continued research in this field. , Thesis (MSc) -- Faculty of Science, Biochemistry, Microbiology & Bioinformatics, 2024
- Full Text:
- Date Issued: 2024-10-11
Connecting culture and science: Utilising Oshikundu and Ombidi in biology lessons on diffusion and osmosis
- Authors: Shilomboleni, Helena Ilena Ndilimeke
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/463636 , vital:76427
- Description: Various science curricula including that of Namibia recommend that teaching and learning should start with the knowledge and experiences of learners from their homes and communities. These experiences are the learners’ Indigenous Knowledge (IK) which should be integrated to make science accessible and relevant to learners from diverse sociocultural backgrounds. This suggests that science teachers are encouraged to integrate IK into their teaching to help learners grasp abstract concepts and construct their own understanding of phenomena. However, much literature has revealed that many teachers find it difficult to integrate IK into their science teaching. Some scholars further argue that teachers lack the pedagogical content knowledge to effectively integrate IK. I assume this could be because the science curriculum is not explicit on how IK should be integrated into science teaching. It is against this backdrop that in this study I mobilised the Indigenous technologies of making oshikundu and preserving ombidi to support Grade 10 Biology learners in talking and making sense of diffusion and osmosis. This study was underpinned by the interpretivist and Indigenous research paradigms. Within the Indigenous research paradigm, I focused on Ubuntu as a perspective. A qualitative case study was employed and conducted at a certain school in the northern part of Namibia, in the Ohangwena region. I worked with a group of 35 Grade 10 learners, two Indigenous Knowledge Custodians (KCs) who are the custodians of cultural heritage and one Biology teacher (critical friend) as participants in this study. Qualitative data were collected using a focus group interview (sharing circle), group activity, participatory observation, and learners’ journal reflections. Vygotsky’s sociocultural theory together with Ogunniyi’s Contiguity Argumentative Theory were used as lenses to analyse data. The findings of the study revealed that during the IKCs’ practical demonstrations learners were able to identify science concepts embedded in the cultural practices of making oshikundu and preserving ombidi. The findings further revealed that the practical demonstrations enhanced active participation and interactions among learners. I thus recommend that teachers should tap into IKCs’ cultural heritage by inviting them into their classrooms to make science relevant, accessible and meaningful to learners. , Thesis (MEd) -- Faculty of Education, Secondary and Post-School Education, 2024
- Full Text:
- Date Issued: 2024-10-11
Design and fabrication of millifluidic devices for maintenance of tissue cultures under perfusion
- Authors: Buthelezi, Khanyisile Thando Fatima
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/464358 , vital:76504
- Description: Restricted access. Expected release in 2026. , Thesis (MSc) -- Faculty of Science, Biotechnology Innovation Centre, 2024
- Full Text:
- Date Issued: 2024-10-11
Developing transformative community-university partnerships: a participatory assessment of Rhodes University community engagement monitoring and evaluation system
- Authors: Nkwinti, Nosipho
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/463592 , vital:76423
- Description: This thesis comprehensively explores transformative community engagement (CE) in higher education, focusing on the context of collaborative community-university partnerships (CUPs) in Makhanda, South Africa. The study aimed to assess and revise the monitoring and evaluation (M&E) system of the Rhodes University Community Engagement division to foster a transformation in CUPs. The research employs an exploratory design to understand the complexities of CUPs and improve the M&E systems by generating new concepts and ideas. A variety of qualitative methods, including focus groups, interviews, and document analysis, were utilized to engage community partners, student leaders, and Rhodes University Community Engagement staff. The participatory approach to research was critical, involving stakeholders in finalizing the M&E framework to ensure it met the shared objective. Data analysis was conducted inductively, with themes emerging from the data to facilitate a bottom-up understanding of the research questions. The study found that diverse community engagement projects at Rhodes University enhanced partnerships between the university and the local community in Makhanda. Participants shared varied understandings and experiences of Community Engagement. They saw CE as crucial for bridging the university-community divide and aiding local development. Furthermore, the research identified the need for a Monitoring and Evaluation system that supports collaborative Community-University Partnerships. Participants collaboratively developed and refined this M&E system, ensuring it aligns with community needs and promotes sustained development in Makhanda. Challenges such as diverse perspectives, logistical issues in focus groups, and power dynamics were also highlighted and addressed through an inclusive and participatory approach. This research highlights the elaborate distinctions of community engagement and the importance of such partnerships in fostering sustainable societal development. The framework developed has practical implications for shaping policies, fostering inclusivity, and promoting responsive university-community engagement that is aligned with community needs. The research concludes by suggesting the value of inclusivity, communication, and a flexible adaptation of practices to maximize the benefits of such partnerships. Future research could explore the longitudinal impacts of university-community partnerships, examine the scalability of the current framework to other universities, and evaluate the long-term socio-economic outcomes of the engaged citizen program on the community. , Thesis (MEd) -- Faculty of Education, Secondary and Post-School Education, 2024
- Full Text:
- Date Issued: 2024-10-11
Developing transformative community-university partnerships: a participatory assessment of Rhodes University community engagement monitoring and evaluation system
- Authors: Nkwinti, Nosipho
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/463603 , vital:76424
- Description: This thesis comprehensively explores transformative community engagement (CE) in higher education, focusing on the context of collaborative community-university partnerships (CUPs) in Makhanda, South Africa. The study aimed to assess and revise the monitoring and evaluation (M&E) system of the Rhodes University Community Engagement division to foster a transformation in CUPs. The research employs an exploratory design to understand the complexities of CUPs and improve the M&E systems by generating new concepts and ideas. A variety of qualitative methods, including focus groups, interviews, and document analysis, were utilized to engage community partners, student leaders, and Rhodes University Community Engagement staff. The participatory approach to research was critical, involving stakeholders in finalizing the M&E framework to ensure it met the shared objective. Data analysis was conducted inductively, with themes emerging from the data to facilitate a bottom-up understanding of the research questions. The study found that diverse community engagement projects at Rhodes University enhanced partnerships between the university and the local community in Makhanda. Participants shared varied understandings and experiences of Community Engagement. They saw CE as crucial for bridging the university-community divide and aiding local development. Furthermore, the research identified the need for a Monitoring and Evaluation system that supports collaborative Community-University Partnerships. Participants collaboratively developed and refined this M&E system, ensuring it aligns with community needs and promotes sustained development in Makhanda. Challenges such as diverse perspectives, logistical issues in focus groups, and power dynamics were also highlighted and addressed through an inclusive and participatory approach. This research highlights the elaborate distinctions of community engagement and the importance of such partnerships in fostering sustainable societal development. The framework developed has practical implications for shaping policies, fostering inclusivity, and promoting responsive university-community engagement that is aligned with community needs. The research concludes by suggesting the value of inclusivity, communication, and a flexible adaptation of practices to maximize the benefits of such partnerships. Future research could explore the longitudinal impacts of university-community partnerships, examine the scalability of the current framework to other universities, and evaluate the long-term socio-economic outcomes of the engaged citizen program on the community. , Thesis (MEd) -- Faculty of Education, Secondary and Post-School Education, 2024
- Full Text:
- Date Issued: 2024-10-11
Development of a novel agar-based microtitre plate system for construction of consistent biofilm models and subsequent use in antimicrobial screening
- Authors: Davies, Michaela Roxanne
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/464369 , vital:76505
- Description: Restricted access. Expected release in 2026. , Thesis (MSc) -- Faculty of Science, Biotechnology Innovation Centre, 2024
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- Date Issued: 2024-10-11
Development of efficient protocols to generate breast cancer spheroids for application in drug discovery
- Authors: Ntsoyi, Nomaphelo Ntombikayise
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/464380 , vital:76506
- Description: Restricted access. Expected release in 2026. , Thesis (MSc) -- Faculty of Science, Biotechnology Innovation Centre, 2024
- Full Text:
- Date Issued: 2024-10-11