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Fatigue life and whip peen process parameter influence as applied to 21CRMOV5-7 turbine rotor steel
Get PDFSteam turbines are susceptible to Stress Corrosion Cracking (SCC) and fatigue failure during their life in-service. As a result, over the years, a variety of maintenance techniques have been used to guarantee their continuous production of electricity. Among these techniques, the grinding method stands out as the most used technique in the refurbishment of steam turbine rotors. The grinding process was used in this study to create grooves to remove cracks that were caused by SCC before they matured to fatigue failure. In addition, post the grinding process, a novel technique employed by eNtsa, called whip-peening, was utilised as a surface treatment to introduce a compressive surface layer to prevent crack initiation. This study considered all variables relating to the serration grinding process, developed by eNtsa, for refurbishment of stress corrosion damage. However, the main research focus was directed at developing a combination or a set of feasible whip-peening process parameters to restore compressive residual stress conditions along the grinding path, post the crack removal through grinding. Additionally, fatigue data was analysed to describe any shift in the fatigue life as a function of peening cycles. The research focused on determining the ideal number of peen or sweep cycles to improve the fatigue life of a grooved 21CrMoV5-7 alloy steel material used to produce steam turbines. Two peening parameters were selected, namely, 10 and 40 peening sweeps. The residual stresses were measured using the iXRD system to study the improvement of residual stresses from ground coupons to peened coupons. The induced residual stress results confirmed peening to improve the residual stresses from tensile to compressive, namely, from 200 MPa to -500 MPa. There was no significant difference between the 10 and 40 induced compressive residual stresses. These stresses were found to be satisfactory to enhance the fatigue life of the 21CrMoV5-7 alloy steel.Thesis (MEng) -- Faculty of Engineering, the Built Environment, and Technology, School of Engineering, 202
Improving the survival of SMMEs in the New Brighton township of Gqeberha through support partnerships
Get PDFTownships in South Africa are home to a significant proportion of the country's population and have historically been recognized as vital areas for economic development. With untapped potential to become thriving economic hubs, these regions hold the promise of addressing pressing socio-economic challenges such as unemployment and poverty. The SMMEs in New Brighton Township, Gqeberha, are diverse and primarily consist of retail, service-based, and informal businesses. Key sectors include spaza shops, street vendors, hair salons, small-scale manufacturing, automotive repair services, and hospitality (such as taverns and fast-food outlets). These enterprises play a crucial role in local economic development, providing essential goods, services, and employment opportunities despite facing challenges like limited funding, infrastructure constraints, and market competition. These include limited access to funding, inadequate infrastructure, regulatory burdens, and insufficient strategic support. This study focused on the New Brighton Township in Gqeberha, a region with considerable economic potential yet constrained by significant socio-economic challenges. Using a qualitative research methodology, this study explored the barriers to SMME sustainability and the role of support partnerships in overcoming these challenges. Purposive sampling was employed to select 12 SMME owners in New Brighton, and semi-structured interviews were conducted to gather in-depth insights. These interviews provided valuable perspectives on the specific obstacles faced by SMMEs, the influence of support partnerships on their survival, and the broader impact of franchised businesses on local enterprises. The findings revealed that barriers such as limited financial support, lack of capacity-building opportunities, and insufficient community engagement impede SMME growth. Conversely, collaborative support partnerships between government, private sector stakeholders, and local entrepreneurs were identified as critical to enhancing SMME sustainability. This research highlights the need for tailored interventions to address the unique challenges faced by township based SMMEs. Recommendations include the development of strategic alliances that provide financial support, training programs, and community-oriented business strategies. By fostering robust support partnerships, stakeholders can help SMMEs in New Brighton achieve resilience, stimulate local economic growth, and contribute to inclusive development. This study contributes towards bridging the knowledge gap on township based SMMEs, offering actionable insights for policymakers and practitioners committed to empowering these vital economic drivers.Thesis (MBA) -- Faculty of Business and Economic Sciences, Business School, 202
Covid-19 pandemic and livelihoods of SMME owners in the retail food and beverage industry in Gqeberha
Get PDFThis study aimed to investigate the effect of the COVID-19 pandemic on Small Micro and Medium Enterprises (SMMEs) in the retail food and beverage industry in Gqeberha, South Africa. The study’s objectives were to determine the effects of COVID-19 on SMMEs, examine the challenges faced, investigate the pandemic's effects on performance, identify resilient strategies adopted, and develop livelihood coping strategies for SMME owners. The study explored existing literature, developed a conceptual framework, infused theoretical grounding, and described the operationalisation process and data collection methods. The study follows an interpretivist research philosophy and uses sustainable livelihood and capability approaches to ground the study theoretically. The research adopts a hybrid methodology, incorporating a Systematic Literature Review (SLR) and qualitative semi-structured interviews with purposively selected participants in Humewood, Walmer, Gqeberha Central Business District (CBD), and the Summerstrand suburbs of Gqeberha. The methodology, including data collection and ethical considerations, is thoroughly explained and prioritised throughout the study. The study also conducted a bibliometric analysis and selected 192 peer-reviewed articles for the global SLR, 6 grey literature (newspaper articles), and 2 articles for the Gqeberha SLR. The study population comprises SMME owners/managers with 5 to 200 staff in the retail food and beverage industry in Gqeberha. The findings revealed that many SMMEs in the retail food and beverage industry had to close during the mandatory lockdown period, while others struggled to keep their businesses afloat due to the significant impact of the pandemic. Challenges such as logistics, customer compliance with health and safety regulations, sales, and staffing issues were prevalent. Some SMMEs experienced improved turnover despite initial concerns, while others faced decreased sales and customer numbers. SMMEs adopted various resilient strategies, including implementing health and safety standards, utilising social media for marketing, offering specials, and promoting takeaways to adapt to the challenges posed by the pandemic. To survive the COVID-19 challenges, SMMEs in the retail food and beverage industry must prioritise operational resilience and strategic innovation. This study provides valuable insights into the specific difficulties SMMEs face in Gqeberha and offers recommendations to assist current and future SMME owners in navigating the effects of the pandemic. The findings of the research and the proposed strategies aim to assist SMME owners in the retail food and beverage industry in mitigating the challenges posed by the COVID-19 pandemic and building resilience in the face of future disruptions by similar pandemics.Thesis (PhD) -- Faculty of Business and Economic Sciences, School of Economics, Development and Tourism, 202
The implications of alluvial diamond mining for rural communities of Chiadzwa-Marange, Zimbabwe
No full textThe extraction of metals and minerals has had, and continues to have, material implications for society. Given the significant growth in alluvial diamond mining activities witnessed in Chiadzwa, a rural community situated just southwest of Zimbabwe's third largest city, Mutare. This study focuses on the implications of alluvial diamond mining for rural communities of Chiadzwa-Marange, Zimbabwe. It assesses the socioeconomic and environmental impacts of alluvial mining on rural communities. It also establishes the measures put in place by mining companies and governments to mitigate and enhance the effects of alluvial diamonds. It further identifies policy gaps and recommends strategies for improving the positive implications while mitigating the negative impact of alluvial diamond mining. The study was influenced by the Resource Curse Theory, Political Ecology Theory and the Conflict Theory. The study was an explorative case study utilising qualitative data collection methods. Qualitative data were gathered through a systematic review of the literature and bibliometric research. The bibliometric research findings discussed the current state of the research and probable future directions on the study topic. Documents were selected using non-probability sampling methods, including purposive and snowball sampling techniques. The systematic review employed qualitative content analysis and bibliometric analysis to examine the collected data. Whilst the bibliometric analysis used VOS viewer software to perform bibliometric network visualizations, trend, and clustering and citation analysis on the study topic. Both the systematic literature review and bibliometric research were, carried out using multiple data bases. The study findings showed that the implications of alluvial diamond mining activities for the Chiadzwa community were two-fold, namely, positive and negative. A major finding of this study was that the adverse effects of alluvial diamond mining outweighed the potential positive benefits of alluvial diamond mining for the host community. Hence, there was a need to avert this gap. It was evident from the study findings that alluvial diamond mining activities continued to have adverse implications on the well-being and lives of the Chiadzwa people. As such, the host community were largely excluded from the significant benefits of alluvial diamond mining. The findings were further corroborated by a bibliometric analysis carried that examined 2,159 publications on alluvial diamond mining. The keywords "Zimbabwe," "diamond," and "mining," which had a total link strength of 2,385 emerged as the most frequently occurring terms. This highlights the significance of research focused on understanding the impact of alluvial diamond discoveries and mining activities in the Chiadzwa-Marange community in Zimbabwe.This signified the importance of research to understand the implications of alluvial diamond discoveries and mining taking place in Chiadzwa-Marange community in Zimbabwe.The diamond discoveries in Chiadzwa mirror other African countries where natural resources are becoming a curse rather than a blessing to countries. The study contributes to our understanding of the implications of alluvial diamond mining for rural communities in Zimbabwe and other regions experiencing the same phenomena. Given the adverse implications, it is recommended that multi-stakeholder platforms, improved legal frameworks, corporate social responsibility initiatives, and effective monitoring mechanisms be used to ensure sustainable and equitable alluvial diamond mining practices in the Zimbabwean mining sector.Thesis (MPhil) -- Faculty of Business and Economic Sciences, School of Economics, Development and Tourism, 202
Evaluating the role of special economic zones and SMMEs’ sustainability: a case study of Coega
Get PDFThis research assesses the influence of Special Economic Zones (SEZ) on the sustainability of Small, Medium, and Micro-sized Enterprises (SMMEs) in the Eastern Cape. The main goal is to improve the comprehension of the role of SEZs and to identify the obstacles that hinder the growth and sustainability of SMMEs. The literature suggests that funding, skills, and management are identified as the major constraints hindering sustainability. Additionally, the study analysed the financial and administrative support provided by Coega SEZ that could enhance SMME sustainability, as well as the policies and programs that can support SMME businesses. Small, Medium, and Micro Enterprises (SMMEs) face a range of challenges that hinder their growth and sustainability, despite government efforts to support them. Among these challenges, limited financial resources stand out as one of the most significant obstacles. Without adequate capital, SMMEs struggle to scale their operations, invest in necessary technology, or hire skilled employees. This case study of the Coega SEZ in South Africa examines its impact on Small, Medium, and Micro Enterprises (SMMEs), highlighting how SMME development can drive various socio-economic benefits. The qualitative research demonstrates that by simultaneously providing access to opportunities, finance, and technical and managerial expertise, Special Economic Zones (SEZs) can serve as a valuable policy tool for SMMEs, helping them overcome key challenges. The case study offers policy recommendations on how to leverage SEZs to support SMME growth and development. The study utilized a qualitative research methodology and employed a non-probability, purposive sampling technique to select a sample of fifteen participants. Data was collected through semi-structured interviews and analysed using thematic analysis. The main findings indicated that small, medium, and micro enterprises (SMMEs) often lack industry knowledge and face challenges related to skills and finance. The study recommended greater support from the government and multinational companies for SMMEs, along with incentives for financial institutions that assist them. Additionally, government intervention during periods of high interest rates was suggested. The study also emphasized the importance of SMMEs enhancing their skills and diversifying their businesses.Thesis (MBA) -- Faculty of Business and Economic Sciences, Business School, 202
“I be African man original”: a study of the vernacular intellectual contribution of Fela Anikulapo Kuti in post-colonial Nigeria
Get PDFThis thesis investigates the intellectual legacies of Fela Anikulapo Kuti. In positioning him as a ‘vernacular intellectual’ within the postcolonial Nigerian landscape, this study applies endogenous approaches (Orunmilaist perspective and Ti’bi-t’ire logic), which are complimented by Grant Farred's (2003) concept of the vernacular intellectual. The intersection of these three approaches forms this study's Trifocal lens approach as a conceptual and methodological framework. Influenced by the post-colonial Nigerian setting, this study argues that Fela's music transcends mere entertainment but is an important vehicle for conscientizing the Nigerian community for social change. Incorporating insights from the literature on the global impact of popular music, the study situates Fela alongside other musicians and intellectuals who have historically mobilised societal transformation. The research foregrounds Fela’s discography, employing Critical Discourse Analysis (CDA) to decode the socio-political ideologies embedded within his songs. These narratives are contextualised with historical and contemporary issues in Nigeria, demonstrating Fela's relevance in critiquing power, politics, and identity construction. Additionally, the thesis underscores the importance of oral traditions and vernacular relationality (Eze, 2008) in understanding Fela’s role as a cultural and intellectual figure who challenged oppressive regimes and inspired collective consciousness among Nigerians. Critical Discourse Analysis (CDA) was supplemented by interviews with family, friends and figures deeply connected to Fela’s music and philosophy. Through these interviews, the study found that Fela’s politics and agency as a vernacular intellectual are shaped by language, community, and historical moments. The research study maps Fela’s discursive strategies against Nigeria’s post-colonial challenges while highlighting his enduring intellectual impact on contemporary social movements. This thesis hopes to contribute to the growing body of African sociological thinking in excavating the vernacular concepts in understanding the impact of music, arts, and popular culture in shaping societal change.Thesis (Phd) -- Faculty of Humanities, School of Governmental and Social Sciences, 202
factors influencing value creation through design thinking in the hospitality industry in Ghana
Get PDFGlobally, as the hospitality industry continues to change, there is a growing emphasis on the application of innovative management tools to stay competitive in the global market. Design Thinking and value creation have become the management intervention. Design thinking and value creation are receiving attention in the business sector as panaceas for developing human-centered services to satisfy customers and create value for organisations. Value creation is how business organisations create and offer products and services for customers that are willing to pay and how they attempt to capture a share of the total value that is created in the resultant economic exchange processes. This research study critically identified and examined factors influencing value creation through Design Thinking in the hospitality industry in Ghana. Specifically, it examined how two different concepts of Design Thinking influenced value creation in the hospitality industry in Ghana. The study adopted a quantitative approach to gather data. Based on Fowler’s table a disproportionate stratified sample was used to select a sample size of 315 with a confidence level of 95% at a 5% margin of error. Partial least square structural equation modelling (PLS-SEM) was used for the analysis and evaluation of the hypothesised model. Findings showed that technology, employees’ knowledge and skills, external actors and financial strength through Design Thinking have a statistically significant relationship with value creation in the Ghana’s hospital industry evidenced in their respective p-values. Technology shows a moderate influence on value creation relative to external actors while the Employee knowledge and skills are crucial for service delivery in the hospitality industry. Mediation effects were asymmetrical in distribution across constructs including technology, external actors, and financial strength. While the Q² values indicate strong predictive relevance, the moderate R² values of constructs such as technology and employee knowledge and skills suggest that other unmeasured factors also have influence on value creation.The following recommendations were made based on the key results of the study, namely hospitality businesses in Ghana should invest in training employees and managers in the principles of Design Thinking. Workshops, collaborative brainstorming sessions and innovation labs will help to better embed Design Thinking into routine activities and nurture a culture of creativity and problem-solving. The industry should invest in state-of-the-art technologies such as CRM systems, mobile applications for bookings, and AI-driven data analytics to enhance customer experiences in streamlining operations and achieving cost efficiencies. The hospitality industry must implement training programmes that have a focus on both technical and soft skills, tailor-made for employee knowledge and skills to fully meet dynamic customer needs. The study also recommended the strengthening of relationships with external actors such as customers and other stakeholders, suppliers, travel agents in value creation strategies by requesting customer feedback through surveys and focus groups to adapt services to meet the diverse needs to foster loyalty. Other recommendations included leveraging financial resources strategically in areas that yield the highest returns, target emerging and luxury market segments, creating innovation by collaboration with industry players in policy formulation service models suitable for the Ghanaian market. The study further recommended the application of key performance metrics for the monitoring and evaluation of customer satisfaction, employee productivity, and financial performance to highlight areas for improvement to align with value creation goals. Finally, the government and industry associations should create a favourable regulatory environment, as well as incentives for innovation and investment to enhance the industry’s value creation capability. Further study should be conducted into the exploration of cultural influences on Design Thinking and value creation in the Ghanaian hospitality industry. Furthermore, a longitudinal study should be conducted on the long-term effects of the implementation of Design Thinking practices on value creation.Thesis (PhD) -- Faculty of Business and Economic Sciences, School of Management Sciences, 202
B.Ed fourth-year primary school pre-service mathematics students’ perceived experiences of their mentoring experience with their mentor teachers during their school-based learning professional development component
Get PDFThis dissertation examines the role of mentorship in shaping the professional development of fourth-year B Ed pre-service mathematics teachers during their School-Based Learning (SBL) placements. Grounded in an expanded version of Hudson’s five-factor mentoring model, the study assesses the quality and impact of mentor-mentee interactions, illuminating how mentorship influences the growth of pre-service teachers. Using an explanatory sequential mixed-methods approach, the study integrates quantitative and qualitative data within a pragmatic framework. Surveys with Likert scales collected quantitative data, while qualitative insights were drawn from open-ended questionnaires, semi-structured interviews, and focus group discussions. Structural Equation Modelling (SEM) was used to analyse the relationship between mentor attributes—such as pedagogical knowledge, feedback, and self-efficacy—and pre-service teachers’ perceptions of mentorship. The thematic analysis further explored mentees’ lived experiences. Findings reveal that mentorship is a reciprocal and dynamic process that has a significant impact on the growth of pre-service teachers. Key themes include developmental scaffolding, collaboration, and the application of theoretical knowledge to practice. Statistical analyses highlight strong correlations between specific mentor qualities (e.g., pedagogical feedback) and mentees’ perceptions of mentorship effectiveness. However, challenges such as inconsistent feedback, limited ICT integration, and varying levels of mentor engagement were identified. To enhance mentorship, the study recommends structured mentor training, greater university oversight, and strengthened mentor-mentee relationships. It also advocates workshops and webinars to equip both mentors and mentees with practical teaching strategies. This research contributes to the field by offering an evidence-based framework for improving school-based mentorship. By addressing existing gaps, it provides actionable strategies to enhance professional development for pre-service teachers, ensuring they are better equipped to meet the demands of the teaching profession in South Africa and beyond.Thesis (MEd) -- Faculty of Education, School of Education, Research and Engagement, 202
Laboratory-scale study of Sinkhole Progression : An analysis using a simple OFDR configuration and a proposed signal processing workflow
Get PDFKarstic formations pose significant risks for sinkhole development, threatening surrounding health of infrastructure. The gradual shift from conventional geophysical methods towards less invasive ground-based sensing, has facilitated the adoption of Distributed Optical Fibre Sensing (DOFS) technologies. The expansion of fibre-optic telecommunication networks in urban environments further enhances the feasibility of DOFS for sinkhole monitoring. Through the use of this established network, cavity formation and sinkhole collapse may be adequately monitored for future mitigation efforts and risk assessment. This study investigates cavity formation and sinkhole evolution using a dual-interferometric Optical Frequency Domain Reflectometer (OFDR) distributed strain sensor in laboratory scale instrumented models. A proposed signal processing workflow incorporates a resampling algorithm applied prior to distributed strain calculations for enhanced spatial resolutions. Distributed strain calculations were preformed using a Discrete Fourier Transform with a window size of 20,000,000 and 256, respectively, at a sampling rate of 50 KHz, achieving a sweep range of ⁓18 GHz. The investigated OFDR configuration achieved successful calibration, detection, monitoring and quantitative analysis of strain variations associated with cavity formation and sinkhole evolution. Additionally, inexpensive capacitance-based soil moisture sensors were integrated for wetting front tracking. Probability density estimation was used to classify shifts in the dominant strain type along the sensing fibre related to cavity formation and sinkhole collapse. Cavity formation is initially governed by tensile-dominated strain, transitioning to a compressive strain environment as cavities develop, before reverting to tensile dominated systems at sinkhole collapse. These findings provide a foundation for future early waring detection methods in distributed strain networks. Integrating artificial intelligence with fibre optic infrastructure could significantly enhance precursor cavity formation monitoring, improving early waring detection methods and risk assessment.Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 202
Macroinvertebrates associated with seagrass at point-source pollutant inputs in the Knysna Estuary
Get PDFEstuaries are important ecosystems that provide many functions, including filtering nutrients and other contaminants from surrounding catchments before they reach the ocean. These services are provided by habitats such as seagrasses. Increasing anthropogenic pressures and development threaten the integrity of such coastal ecosystems. Nutrient enrichment or eutrophication affects seagrass habitats globally, causing ecosystem degradation and loss of ecological and economic value. Nutrient enrichment can induce various changes to both the floral and faunal communities within estuarine environments. These effects include the proliferation of opportunistic algae and shifts in macroinvertebrate community structure from sensitive to resilient taxa. The aim of this study was to investigate the drivers and responses of Zostera capensis and the macroinvertebrates dwelling within its rhizosphere, to nutrient pollution at the Knysna Estuary, South Africa. This was achieved by quantifying seagrass metrics, sediment characteristics and macroinvertebrate indices at six polluted sites (referred to as point-sources) along the Knysna Estuary. Sampling was carried out quarterly from May 2023 to January 2024. Direct indices of nutrient pollution were measured as nutrient concentrations (N and P) in seagrass tissue of above- and belowground biomass, the overlying water column as well as in epiphytic tissue. A nutrient gradient was determined across the point-sources. Sites sheltered from wave action were more nutrient enriched than exposed sites, reflecting their depositional nature. Bongani River (which is linked to a wastewater treatment works) was identified as the most polluted site, however, δ15N isotopic signatures in Z. capensis leaves were not consistently indicative of enrichment. This could be related to seasonal trade-offs of nutrient requirements or poorly primary treated wastewater resulting in depleted δ15N signals (mean of 1.76 ± 4.65 ‰). Featherbed, which is an exposed site, was the least polluted. Seagrass metrics did not increase in response to high nutrient concentrations but rather a decrease in above- and belowground biomass was observed. This could be linked to long-term enrichment with nutrient levels exceeding plant growth needs, leading to reduced growth from direct effects such as NH4 + growth suppressant, or secondary effects such as overgrowth from other primary producers or sediment anoxia. Nutrient storage (N and P) in Z. capensis above- and belowground biomass did not differ overall. Epiphyte biomass increased in response to high nutrient concentrations and demonstrated a high nutrient storage capacity, suggesting that epiphytes responded more rapidly to nutrient enrichment. The highest epiphyte biomass was recorded at Bongani (61.6 ± 28.87 mg m-2), while Featherbed had the lowest (21.71 ± 21.63 mg m-2) epiphyte biomass. Nutrient enrichment effected a change in site-specific community composition of macroinvertebrates associated with the rhizosphere sediment. The dominance of general pollution-tolerant groups such as clitellates and polychaetes and the low abundance of pollution-sensitive groups such as burrowing amphipods was observed at Bongani compared to other sites. The Benthic Opportunistic Annelids Amphipods (BO2A) index highlighted the poor ecological status of Bongani and the comparatively less polluted conditions at Featherbed. Regression modelling suggested that sediment characteristics such as redox was the dominant driver of macroinvertebrate responses (abundance, richness and diversity). A well oxygenated habitat is a crucial metabolic requirement forvfauna. A higher sediment redox potential indicating aerobic conditions reflected higher macroinvertebrate abundance and richness. The rhizosphere sediment was predominantlyvsilty (2.8 ± 1.29 μm). Sandier sediment was negatively related to species richness andvsediment with higher clay content was negatively related to polychaete abundance. Thesevresults suggested that indirect effects of increasing organic matter and nutrient loading linked to sediment type can increase oxygen consumption, lowering redox potential whichvcollectively negatively affects the benthic fauna.vDeteriorating water quality is becoming more prevalent in South Africa and worldwide.vMonitoring effluent flows and the effects it has on water resources is vital to combatvpollution. This study showed that different indicators of nutrient enrichment such asvseagrass, macroinvertebrates and epiphytes can be effectively used in studies investigating pollution impacts on coastal environments. Although seagrass habitats have been shown tovimprove water quality through storage and filtering capacity, efforts should steer towardsvreducing excess nutrient input received from catchments. This is especially true in sensitivevareas where seagrass is exposed to long-term nutrient enrichment. Many studies have experimentally tested enrichment effects across various timeframes. However, more in-situvinvestigations should be conducted to assess combined seagrass and macroinvertebratevresponses to eutrophic conditions. This is necessary to protect the ecological functionsvprovided by these components which are intrinsically linked.Thesis (MSc) -- Faculty of Science, Life, Earth, Environmental & Agricultural Sciences Cluster, 202