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We are the Crystal Gems taxonomic revision of the gemfruited species of Commelina L Commelinaceae Commelinales and their allies
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Choose Your Character: The Motivations Behind Character Selection in the Art of Cosplay
No full textA dissertation submitted in fulfilment of the requirements for the degree of Master of Arts in Digital Arts, to the Faculty of Humanities, Wits School of Arts, University of the Witwatersrand, Johannesburg, 2025Most conventions and geek gatherings around the world will undoubtedly have at least a couple of attendees who have dressed in cosplay as various characters from popular culture. These cosplays range from instantly recognisable characters such as Darth Vader to characters that only the greatest superfans will be familiar with. They can be assembled from cardboard and regular clothes made a couple of days before the convention or be completely screen-accurate cosplays years in the making. With cosplay being such a diverse medium, this research aims to investigate the process that cosplayers undergo when choosing a character to cosplay. This research is also focused on cosplayers residing in South Africa and makes use of detailed and in-depth surveys and interviews with multiple members of the South African cosplay community to understand and classify the various aspects that play a role in the character selection process. This research makes use of discourse analysis to analyse the answers provided by participants, as well as the context of these answers to develop a deeper understanding.MMM202
Optimal Design and Operation Control of Electrical Vehicle Battery Swapping Station incorporating Hybrid Renewable Energy and Grid Power Systems
No full textA research report submitted in fulfillment of the requirements for the Master of Science, in the Faculty of Engineering and the Built Environment, School of Chemical and Metallurgical Engineering, University of the Witwatersrand, Johannesburg, 2025Transportation is a major contributor to air pollution and one of the largest consumers of fossil fuels. As a sustainable alternative, electric vehicles have gained widespread adoption due to advances in technology, the expansion of public charging networks, and improvements in battery materials and charging infras- tructure. However, limitations in the charger power capacity and battery characteristics of electric vehicles often result in longer charging times compared to refueling traditional vehicles, leading to range anxiety and hindering broader adoption. To address this challenge, battery swapping stations have emerged as an innovative solution, allowing drivers to exchange depleted batteries for fully charged ones, thus minimizing downtime and enhancing the feasibility of electric vehicles for modern transportation systems. Recent research has explored the concept of battery swapping stations, presenting various optimization approaches and operational systems. Battery swapping station providers have successfully implemented swapping services at both private and commercial stations. This research study focuses on the optimal design approach and operation management strategy of battery swapping stations, with a particular em- phasis on leveraging renewable energy sources, such as wind turbines and photovoltaic systems, as primary resources for charging the depleted electric vehicle battery. The aim is to develop solutions that minimize energy consumption and operational costs while enhancing charging performance by reducing the swapping service time. For this purpose, first, an optimal design for a battery swapping station integrated with a grid-connected hybrid power supply system is developed and evaluated. The optimization problem is formulated to minimize the overall life cycle cost and reduce electricity costs purchased from the utility grid while maximizing its reliability. This model provides continuous, cost-effective power support and implements a scheduling strategy that consistently meets charging demand. Mixed integer linear programming is used to determine key decision variables, such as the power drawn from the utility grid and the number of wind turbines and solar photovoltaic panels. Simulation results demonstrate that the optimal configuration, including wind turbines and solar panels, yields significant energy cost savings over its lifecycle. In addition, an economic analysis is performed to assess the payback period, an essential metric for investors. Secondly, an optimal operational control strategy is developed and evaluated for grid-connected wind-solar power generation with a storage system for the battery swapping station. The strategy minimizes the total operational costs associated with the cost of electrical energy purchased from the utility grid and the wear cost of the hybrid system due to the frequent charging and discharging of the battery energy storage system. At the same time, it maximizes the self-consumption of locally generated renewable energy. This optimization model ensures a cost-effective power supply that efficiently meets charging demands while selling excess energy back to the utility grid. The simulation results from four scenarios show that the model optimizes energy use, reduces costs, and increases hybrid power feedback to the utility grid. The main outcome is improved energy efficiency, cost savings, and additional revenue from surplus power sales. vi The impact of this outcome is enhanced financial viability, demonstrated through an economic analysis that evaluates the investment feasibility and payback period of the proposed system. Thirdly, a model predictive control approach is designed and evaluated to determine the optimal opera- tional strategy for a battery swapping station integrated with a grid-connected wind-solar power generation system and a battery energy storage system. The primary objective is to minimize the operational costs of the proposed system. By implementing model predictive control (MPC), the system dynamically optimizes power flow in real-time to account for uncertainties and disturbances. A comparative analysis is conducted between open-loop control and MPC-based closed-loop control under various scenarios, with and without disturbances. The simulation results demonstrate that the closed-loop MPC approach consistently out- performs the open-loop model, exhibiting superior robustness and adaptability in handling uncertainties. By optimizing power flow in real-time, MPC ensures efficient power distribution, reduces reliance on the utility grid, and maximizes renewable energy utilization. Despite its computational complexity, model predictive control offers significant advantages in industrial applications, enhancing efficiency, reliability, and cost-effectiveness through real-time optimization. The findings of this research underscore the effectiveness of integrating battery swapping stations with demand-side management strategies. This integration plays a crucial role in advancing sustainable urban transportation, enhancing the efficiency of electric vehicle infrastructure, and improving the reliability and stability of the utility grid.MM202
The Influence of Mobile Applications on Loyalty Programme Engagement Among Low-Income Consumers in South Africa
No full textA research report submitted in fulfillment of the requirements for the Master of Business Administration, in the Faculty of Commerce Law and Management, Wits Business School, University of the Witwatersrand, Johannesburg, 2025With mobile apps becoming central to brand-consumer interactions, understanding their role in driving loyalty among economically disadvantaged users is crucial. This study explores how mobile applications influence loyalty programme (LP) engagement among low-income consumers in South Africa. Using a qualitative approach, the research examined user experiences, challenges, and motivations through semi-structured interviews with eight participants residing in and around Johannesburg townships. Findings revealed that perceived ease of use, usefulness, affordability, and data accessibility significantly impact engagement. Participants valued simple app interfaces, clear reward structures, and real-time tracking but faced challenges like high data costs, complex point systems, and limited educational resources. To address these challenges, the study proposes a model for improving mobile app LP engagement among low-income consumers, offering a practical framework for businesses to enhance engagement through user-focused solutions. This model emphasises zero- rated apps, simplified onboarding, affordable access, and personalised rewards, alongside continuous evaluation and refinement. The findings contribute to inclusive marketing strategies and support economic capacitation for low-income consumers by promoting more accessible and impactful mobile-based LPs.MM202
Growth Inhibition of Algae in Aquaculture Fishponds Using Banana Peel Powder A Mesocosm Experiment
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ParameterEfficient FineTuning of Pretrained Large Language Models for Financial Text Analysis
No full textThe adequacy of entrepreneurship education in Gauteng TVET colleges in preparing students for entrepreneurship
No full textA research report submitted in fulfillment of the requirements for the Master of Business Administration, in the Faculty of Commerce Law and Management, Wits Business School, University of the Witwatersrand, Johannesburg, 2025The research evaluates the effectiveness of entrepreneurship education in Gauteng TVET colleges, aiming to prepare students for entrepreneurial success. Driven by the rising youth unemployment crisis in South Africa and the limited success of youth-led businesses, the study addresses the gaps between theory and practice in business programmes. It assesses the curriculum's structure, identifies challenges for instructors, and examines factors influencing students’ entrepreneurial readiness aspirations. A qualitative methodology involved semi-structured interviews with 13 participants, including students and lecturers from Gauteng TVET colleges. Findings reveal that the curriculum is overly theoretical, limiting practical exposure and students' readiness for entrepreneurship. Lecturers noted systemic challenges, such as inadequate professional development. Students reported external barriers, including a lack of mentorship, that impact their entrepreneurial aspirations. The study contributes practically by advocating reforms to include experiential learning, such as internships and capstone projects, alongside institutional support structures like mentorship programmes and entrepreneurship centres. Theoretically, it underscores the importance of integrating human capital theory into curriculum design to bridge the gap between knowledge acquisition and practical application. The research emphasises a balanced approach to entrepreneurship education, merging theory with hands-on experiences and support systems, allowing TVET colleges to empower students in entrepreneurial ventures and tackle South Africa's socio-economic challenges effectively.MM202