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Growth performance of three F1 Hybrid tomato (Solanum lycopersicum L.) Cultivars grown in Peat moss and Sawdust
Get PDFThe tomato is one of the most important and commonly grown vegetable crops cultivated by subsistence as well as commercial farmers in South Africa. Even though hydroponic tomato production has gained popularity, tomato production in South Africa is mostly practised open field. This is because most South African households in rural communities depend on agriculture for their livelihoods. Tomatoes are one of the “cash crops” − meaning cash in hand for many farmers. As a staple food for many rural communities and households, tomatoes are prepared as relish daily. Including tomatoes in the human diet provides the benefit of various important nutrients, such as Vitamin C, amongst others. The main aim of this study was to evaluate the growth performance − by assessing the number of leaves, stem diameter, plant height and number of flowers per plant − in three Solanum lycopersicum L. cultivars, namely: F1 hybrids Star9006, TF4009 and TF4011, grown in peat moss and sawdust respectively. In addition, the research aimed at investigating how peat moss and sawdust, as growing media, influenced the growth performance of the tomato cultivars under study. The study was conducted at the Döhne Agricultural Development Institute near Stutterheim in the Eastern Cape. The experiment was laid out in a split randomized complete block design (RCBD) in which the growing media, namely: sawdust and peat moss, were assigned as main plots and the tomato cultivars to sub-plots, with three replicates.Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 202
The Impact of COVID-19 on Maritime Operations at the Port of Mossel Bay
Get PDFThe goal of this study is to evaluate the impact of COVID-19 on maritime operations at the Port of Mossel Bay, South Africa (SA) before and during the COVID-19 pandemic. The Port of Mossel Bay is the smallest commercial port in SA. The Transnet National Ports Authority (TNPA), which is owned by the South African government and reports directly to the Department of Public Enterprises, manages and operates the Port of Mossel Bay. The oil and gas industry, as well as a small fishing fleet, are served by the port at Mossel Bay. Although fishing industry is crucial to the local population in the Southern Cape, the Port of Mossel Bay also manages a number of other commercial activities, which greatly contributes to the South African economy and Growth Domestic Product (GDP). The study focused on four companies, which conduct maritime operations at the Port of Mossel Bay, namely, Mossel Bay Transnet Port Authority, PetroSA, SeaVuna and Viking Fishing Operations. Various literature studies were utilised to gather background information for each company, as well as data for comparison, evaluation and interpretation of maritime operations before, during and after the COVID-19 pandemic. Using an interpretivist approach as a research philosophy, a qualitative research methodology was employed. For the qualitative data collection, participants were contacted, after which the data was analysed, leading to the identification of themes. COVID-19 has had a financial and operational influence on maritime operations at the Port of Mossel Bay, according to the empirical findings. Companies created are continuing to implement, steps to ameliorate the impact of the COVID-19 pandemic to ensure that operations are carried out effectively and efficiently. The intention of this study is to contribute to the body of knowledge to improve the effectiveness and efficiency of marine operations in South African waters and beyond before, during and after the COVID-19 pandemic. Additional benefits of this research are to provide a framework of analysis for restoring maritime operations but also to serve as a preventative framework for prolonged or recurring pandemic phenomena in the future.Thesis (MPhil) -- Faculty of Business and Economic Science, School of Applied Accounting, 202
Effects of Lignin on the properties of reclaimed rubber /natural rubber blends
Get PDFThe environmental challenge posed by waste tyres is a serious global crisis from which South Africa is not isolated. The concept of tyre rubber reclamation into reusable rubber over the years has been on the increase, however, despite the environmental and economic advantages offered by the reclaiming process the main demerits of the resulting rubber include its relatively poor physical and mechanical properties when compared to newly manufactured rubber. The deterioration of these properties arises from the structural changes which occur during the reclaiming process. To overcome this disadvantage, reclaimed rubber can be blended with other rubbers such as natural rubber to compensate for its weak properties. However, there is stilll a limited industrial application of reclaimed/natural rubber blends due to their brittleness and relatively poor impact strength. By adding reinforcing fillers, the mechanical properties of the blends can be significantly improved. In recent years, there has been a renewed interest in the use of lignocellulosic materials as fillers, modifiers and reinforcements in polymeric materials. They are receiving attention because they are the most abundantly available raw materials on earth, and they offer greater versatility compared to inorganic fillers. Being the most abundant renewable agricultural derived lignocellulosic biomass after cellulose, and as far as polymer composites and blends are concerned, lignin has shown promise as a well-received and sustainable alternative to inorganic fillers due to its low-cost production and ability to improve on the biodegradability of polyolefins and minimise loss of ultimate mechanical properties of polymer matrices. The main aim of the research is to investigate the effect of lignin on the properties of reclaimed/natural rubber (RR/NR) blends for possible low-density and eco-friendly rubber materials. The motivation for the research arises from the global challenges that are connected to the dynamic increase of rubber wastes, especially in the form of used tyres and the potential availability of lignin from its annual production from the sugarcane pulp mills, which is regarded as waste. A mixture design of experiments was used to formulate different blends of lignin with reclaimed and natural rubber. The rubber blends and the lignin-rubberThesis (MSc) -- Faculty of Science, School of Biomolecular and Chemical Sciences, 202
The determinants of entrepreneurship in African countries
Get PDFThis research investigates the determinants of entrepreneurship by examining the statistical relationships between entrepreneurship and macroeconomic, human capital, and institutional quality variables in 50 African countries utilising data from 2000-2018. The study intended to contribute to existing literature with new knowledge on the discipline since there is limited literature on African countries. The Generalised Methods of Moments technique was employed to examine the effect of independent variables on the dependent variable using Stata software. The study findings indicate that domestic credit to the private sector, education and training, the rule of law, political stability and absence of violence/terrorism, regulatory quality have a significant effect on entrepreneurship. The remaining selected variables are insignificant. These findings suggest that smooth access to credit through business loans, trade credits, and other accounts receivables from financial institutions as the primary funding mechanism for businesses. Further encouraging entrepreneurship, the African government should ensure that education and training, particularly entrepreneurial education, is available to all inhabitants. Improving existing laws and regulations and enacting new effective laws and regulations that align with the current African business climate is recommended to protect existing and infant businesses by governing the entire entrepreneurial environment.Thesis (MEcon) -- Faculty of Business and Economic Science, School of Applied Accounting, 202
Improving governance and service delivery in Nelson Mandela Metropolitan Municipality: a quest for a clean audit opinion
Get PDFThe purpose of the study was to investigate how Nelson Mandela Bay Metropolitan Municipality (NMBMM) can improve its governance and service delivery to obtain a clean audit outcome. In addition, the study explored the role of auditing in the functioning and performance of municipalities. NMBMM public officials and political office-bearers are expected in terms of Chapter 7 of the Constitution of South Africa Act 108 of 1996 to promote the general welfare of the community by meeting its needs, expectations and demands. The qualitative (non-empirical) research methodology followed in the study was based on a desktop approach. The annual documents reviewed to answer the research objectives were the Consolidated General Reports on the Local Government Audit Outcome and the Reports of the Auditor-General to the Eastern Cape Provincial Legislature and the council on the NMBMM and its municipal entity for the financial period 2015/2016 to 2019/2020. The problem was that the NMBMM did not obtain a clean audit opinion during this period. The study findings indicated that the main contributing factors that prevented the NMBMM from improving governance, service delivery and obtaining a clean audit outcome were as follows: poor management of accounting practices (financial management); inadequate financial statements and performance reports; a lack of adherence to predetermined objectives and legislation; and unauthorised, fruitless, wasteful and irregular expenditure. To attain a clean audit outcome, NMBMM municipal officials and political officebearers need to perform their mandated duties diligently and overcome the challenges that have barred them from obtaining an unqualified audit opinion. Such an endeavour would be consistent with the Operation Clean Audit (OPCA) campaign, which was introduced by the former Minister of Cooperative Governance and Traditional Affairs, Sicelo Shiceka, in 2009. In other words, the NMBMM must improve its governance and service delivery because a municipality without good governance lacks accountability, which has a direct negative impact on the delivery of services to its communities. Hence, it is recommended inter alia that the NMBMM seeks advice from iii the Auditor-General on strategies to improve its audit outcomes, maintains infrastructure, addresses criminal activities and improves its internal controls.Thesis (MSc) -- Faculty of Humanities, School of Governmental and Social sciences, 202
Modular Omni-directional AGV Developmental Platform with Integrated Suspension, Power-plant and Control Systems
Get PDFThe thesis focuses on the development of an industrial automatic guided vehicle (AGV) with omni-directional capabilities. The omni-directional strategy used was the "swerve drive" system, a system whereby a wheel can be rotated about both its y axis (rolling axis) and z axis (vertical axis). Unlike most commonly used swerve drive systems that have swerve capabilities on each wheel attached to the body of the vehicle, this research seeks to reduce cost by only having swerve capabilities on two diagonal wheels. The remaining two wheels will act as castor units. AC drives are used on the system in place of more traditional DC drives, due to their cost vs capability advantage over DC and their prevalence in the industrial environment. Since an AGV is a mobile platform any power source found on it is usually derived from batteries, a DC source. Usage of DC introduces several limitations including difficulty transforming voltage levels for different systems, inability to run AC drives directly from the power source and comparably larger conduction wires. These limitations were overcome by adding a stand-alone power-plant on the AGV in the form of an inverter. The inverter transformed the DC power supplied by a battery bank from 48 volts DC to 230 volts AC. Thus, the primary focus of this research is on the development and validation of a novel two wheel omni-directional drive system that makes use of inexpensive and readily available components that have already been proven to work in industry.Thesis (PhD) -- Faculty of Engineering, the Built Environment, and Technology, 202
The thermal physiology of Lysathia sp.(Coleoptera: Chrysomelidae), a biocontrol agent of parrot’s feather in South Africa, supports its success
No full textThe establishment success of biocontrol agents originating from tropical regions is often limited by climate when introduced in temperate regions. However, the flea beetle, Lysathia sp. (Coleoptera: Chrysomelidae), a biocontrol agent of Myriophyllum aquaticum (Vell.) Verdc. (Haloragaceae) in South Africa, is an effective agent in regions where other biocontrol agents of tropical aquatic weeds have failed due to winter-induced mortality. The development (degree-day model) and thermal tolerance (critical thermal minimum/maximum [CTmin/max] and lower/upper lethal limits [LLT/ULT50]) of Lysathia sp. were investigated to explain this success. The model predicted that Lysathia sp. could complete 6 to 12 generations per year in the colder regions of the country. The lower threshold for development (t0) was 13.0 °C and thermal constant (K) was 222.4 days, which is considerably lower than the K values of other biocontrol agents of aquatic weeds in South Africa. This suggests that above the temperature threshold, Lysathia sp. can develop faster than those other species and complete multiple life cycles in the cooler winter months, allowing for rapid population growth and thus improving M. aquaticum control. Furthermore, the CTmin of Lysathia sp. was 2.3 ± 0.2 °C and the CTmax was 49.0 ± 0.5 °C. The LLT50 was calculated as ∼ −7.0 °C and the ULT50 as ∼ 43.0 °C. These wide tolerance ranges and survival below freezing show why Lysathia sp. has established at cool sites and suggest that it may be a suitable agent for other cold countries invaded by M. aquaticum
Integrating child rights standards in contraceptive and abortion care for minors in Africa
Get PDFMinor girls in Africa face challenges in accessing high-quality contraceptive and abortion services because laws and policies are not child-friendly. Many countries maintain restrictive laws, policies, or hospital practices that make it difficult for minors to access contraception and safe abortion even when the pregnancy would risk their life or health. Further, the clinical guidelines on contraceptive and abortion care are silent, vague, or ambiguous regarding minors' consent. African states should remedy the situation by ensuring that clinical guidelines integrate child rights principles and standards articulated in child rights treaties to enable health providers to facilitate full, unencumbered access to contraceptive and abortion care for minor girls. A sample of clinical guidelines is analyzed to demonstrate the importance of explicit, consistent, and unambiguous language about children's consent to ensure that healthcare workers provide sexual and reproductive health care in a manner that respects child rights
Solvent promoted tautomerism in thione-containing tetraazatricyclics: evidence from 1H NMR spectroscopy and transition state studies
Get PDFTautomerism in the nitro substituted thione-containing traazatricyclics has been investigated. Evidence from 1 H NMR indicating the existence of the tautomers has been augmented with computational studies providing evidence of the stability or otherwise of these tautomers. The role of water and DMSO in the formation of the tautomers has been explained. The role of the nitro group in assisting in the formation of the tautomers has been discussed
Synthesis of 2, 3-dihydroxy-3-(N-substituted carbamoyl) propylphosphonic acid derivatives as hybrid DOXP-fosmidomycin analogues
Get PDFA six-step synthetic pathway has been established to access a series of racemic 2,3-dihydroxy-3-(Nsubstituted carbamoyl)propylphosphonic acid derivatives, designed to contain structural features common to both the natural substrate 1-deoxy-D-xylulose 5-phosphate (DOXP) of the Plasmodium falciparum (Pf) DXR enzyme and its known inhibitor, fosmidomycin. Positive STD-NMR and in silico docking data obtained for some of the compounds indicate their capacity to bind to the analogous E.coli DXR enzyme