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Exchange rate volatility and the returns on diversified South African investment portfolios

  • Authors: Mulamu, Murendeni
  • Date: 2022-04-06
  • Subjects: Foreign exchange rates South Africa , Rate of return , Investments , GARCH model , Regression analysis , ‎Autoregressive distributed lag (ARDL) model
  • Language: English
  • Type: Academic theses , Master's theses , text
  • Identifier: http://hdl.handle.net/10962/284581 , vital:56076
  • Description: Globalisation has made it much easier to invest in foreign countries. This creates endless options accessible to investors, including exploiting opportunities for investment in international economies. Although foreign investment portfolio diversification provides significant opportunities for financial returns, exchange rate volatility may play a prominent role when investing in foreign markets. Since the introduction of a floating exchange rate system, together with the inflation-targeting monetary policy framework in South Africa, there has been significant volatility in the exchange rate, far more than during the previous dispensations. This, however, creates a strong need to consider how the unpredictable nature of the exchange rate affects these investments. The purpose of this study is to analyse the effect of exchange rate volatility on the returns on diversified South African investment portfolios. This research examined whether there is a homogenous relationship between South African (domestic) portfolios and the internationally diversified portfolios. In addition, the study investigated the long-run relationship between the exchange rate volatility and both domestic portfolios and the internationally diversified portfolios for the period 2007-2019. To achieve these goals, a panel ARDL model was employed. This study found that exchange rate volatility does not account for a significant portion of returns on investment portfolios fluctuations. Moreover, the relationship is not homogenous because returns on domestic investment portfolios react positively to the exchange rate volatility, whereas returns international investment portfolios respond negatively/positively to the exchange rate volatility depending on whether the relationship is short or long run. This study will contribute to the existing literature, and it is important for investors intending to diversify their investment portfolios both domestically and internationally using different mutual funds in South Africa. , Thesis (MCom) -- Faculty of Commerce, Economics and Economic History, 2022
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  • Date Issued: 2022-04-06

Exploring the entrepreneurial intention of students in one Higher Education Institution (HEI)

  • Authors: Kenye-Duma, Ayanda Rachel
  • Date: 2022-04-06
  • Subjects: Entrepreneurship South Africa , Intention , Entrepreneurship Study and teaching (Higher) South Africa , Students Attitudes , Social entrepreneurship , Social capital (Sociology) , Unemployment South Africa , Entrepreneurship Development in Higher Education (EDHE)‎
  • Language: English
  • Type: Academic theses , Master's theses , text
  • Identifier: http://hdl.handle.net/10962/284514 , vital:56070
  • Description: This study was interpretive and qualitatively explored students' entrepreneurial intentions at Rhodes University. It was conducted to understand entrepreneurship among students. Understanding students' entrepreneurship is critical as entrepreneurship is touted as a reasonable response to alleviate the high unemployment in South Africa. The study explored how students became entrepreneurs (or how their entrepreneurship intentions were formed) and the factors that enhanced (enablers and barriers) and inhibited them. The significance of living with and after COVID-19, youth and graduate unemployment alleviation places entrepreneurship development by institutions of higher learning, governments and private sector in the centre of economic recovery. The establishment of the Entrepreneurship Development in Higher Education (EDHE) in 2016, highlights the commitment of the South African government, for Higher Education Institutions (HEI) to engage more in entrepreneurship and do more research to understand how students become entrepreneurs and unravel the challenges. Understanding students' entrepreneurship intentions can facilitate a supportive environment for students entrepreneurship. With “very little research about student entrepreneurship at this university” being the guiding research problem, the aim was to gain insight into the entrepreneurship intention of university students by exploring factors that influence students to become entrepreneurs. The study employed Ajzen’s Theory of Planned Behaviour to explore the entrepreneurial intentions of university students in terms of the underlying attitudes, subjective norms, and perceived behavioural control. The students who participated in the study fell into three categories of entrepreneurial intention: (i) Intending to start a business, (ii) starting a business, and (ii) those who were already operating a business. All the participants, irrespective of their stage of entrepreneurial intention, demonstrated a positive attitude and self-efficacy. All participants showed self-efficacy by identifying barriers and taking positive steps to overcome them. The main barriers were access to funding, capital, training, business opportunities with the university and lack of interaction with established entrepreneurs. The results demonstrated the close interplay of attitudes, social norms and perceived behavioural control in students’ entrepreneurial intentions. Social recognition of entrepreneurship, social capital, education and role models contributed to positive attitudes, and social norms influenced students’ entrepreneurial intentions. A supportive environment was found to be critical for nurturing entrepreneurship intentions. The study recommends a supportive climate cultivated by Rhodes University to promote entrepreneurship. The supportive environment must include the elevation of entrepreneurship in prominent offices of the university, strengthening entrepreneurship societies and interactions with established entrepreneurs, and engagement with the private sector to contribute and promote entrepreneurship among students. , Thesis (MBA) -- Faculty of Commerce, Rhodes Business School, 2022
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  • Date Issued: 2022-04-06

Fabrication and characterization of ciprofloxacin loaded niosomes for transtympanic delivery

  • Authors: Mhlanga, Asavela
  • Date: 2022-04-06
  • Subjects: Drug delivery systems , Liposomes , Ciprofloxacin , Quinolone antibacterial agents , Drug carriers (Pharmacy) , Drug stability , Lamellarity‎ , Niosomes‎
  • Language: English
  • Type: Academic theses , Master's theses , text
  • Identifier: http://hdl.handle.net/10962/290715 , vital:56777
  • Description: Ciprofloxacin (CPH) is a broad-spectrum antibiotic used to treat bone, joint, and skin infections. It is commercially available as an extended-release tablet and as a cream dosage form. CPH is a bactericidal active pharmaceutical ingredient (API) of the fluoroquinolone drug class. It inhibits deoxyribonucleic acid (DNA) replication by inhibiting bacterial DNA topoisomerase and DNA gyrase enzymes. Common adverse effects include nausea, vomiting, unusual fatigue, pale skin, and may increase the risk of tendinitis, which could be a major concern. CPH is, according to the Biopharmaceutics Classification System (BCS), classified as a BCS class IV drug exhibiting low oral bioavailability, low solubility, and intestinal permeability. CPH was chosen as a good candidate for the study because of its stability in solutions, its low molecular weight (331.4 g/mol), and its moderate lipophilicity (log P = 0.28) [16]. The use of conventional ear drops in the ear is effective, avoids hepatic first metabolism and extensive protein binding and may reduce adverse effects as a low dose may be used to achieve a therapeutic effect. However, conventional ear drops and oral antibiotics have a long onset of action and have to be taken/applied in short intervals. For convenience and assurance of a long residence time in the ear, CPH may be delivered by using a niosomal formulation, a liquid at room temperature, to allow administration into the ear without the need to constantly apply the ear drops for long periods of time. A simple, rapid, precise, accurate, reproducible, and specific reversed-phase high-performance liquid chromatography (RP-HPLC) method using ultraviolet (UV) detection for the quantitation of CPH was developed and optimized using a central composite design (CCD). The method was validated using International Conference on Harmonisation (ICH) guidelines and was found to be linear, precise, accurate, and specific for the analysis of CPH. Since the method is specific, it was used to quantify CPH in commercial and experimental formulations and monitor CPH released during in-vitro release testing. The compatibility of CPH and potential excipients was investigated during preformulation studies using Fourier transform infrared spectroscopy (FT-IR) and differential scanning calorimetry (DSC) to identify and select suitable excipients for use during formulation development activities. No apparent interactions were evident between CPH, and the excipients tested. The probe sonication method was used to manufacture CPH loaded niosomes using different surfactants/surfactant combinations, and a combination of Tween® 80: sodium lauryl sulfate (SLS) was found to be the best composition in terms of both entrapment efficiency and Zeta potential. The limits for the independent input variables used for the manufacture included amplitude, sonication time, and amount of cholesterol were determined. Design of experiments (DOE) was used to design the study. The input variables investigated included amplitude, amount of cholesterol, and sonication time. The output or responses monitored included Zeta potential, vesicle size, polydispersity index (PDI), and entrapment efficiency. Non-ionic surfactant systems are predominantly stabilized by steric stabilization, and there is only a minor electrostatic element from adsorbed hydroxyl ions. With the inclusion of SLS it is to be expected that Zeta potential will be a contributing factor. DOE using Box-Behnken design (BBD) and response surface methodology (RSM) in addition to Artificial Neural Networks (ANN) were used for the optimization of the formulation. The optimized formulation had a composition of 1 g cholesterol, 1 g of Tween® 80, 1 g of SLS and was prepared at an amplitude of 11.294 % with a sonication time of 3.304 minutes. The formulation exhibited zero-order release kinetics and had an average pH of 7.45. The formulation was stored at 4 ℃ and 25 ℃ and was assessed for vesicle size, entrapment efficiency, Zeta potential, colour, lamellarity, and PDI every 7 days for 4 weeks. The lead formulation stored at 4 ℃ was more stable than the formulation at 25 ℃ in terms of entrapment efficiency, PDI and vesicle size during the 4-week period. CPH loaded niosomes for transtympanic delivery in the treatment of otitis media were developed and optimized. The technology exhibits sustained release of CPH and has the potential for further development and optimization. , Thesis (MSc) -- Faculty of Pharmacy, Pharmacy, 2022
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  • Date Issued: 2022-04-06

Financial technology and bank risk-taking behavior: a case of selected South African banks

  • Authors: Magula, Zizipho
  • Date: 2022-04-06
  • Subjects: Uncatalogued
  • Language: English
  • Type: Master's theses , text
  • Identifier: http://hdl.handle.net/10962/234206 , vital:50172
  • Description: Thesis (MCom) -- Faculty of Commerce, Economics and Economic History, 2022
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  • Date Issued: 2022-04-06

Influence of argon ion implantation on the thermoluminescence properties of aluminium oxide

  • Authors: Khabo, Bokang
  • Date: 2022-04-06
  • Subjects: Aluminum oxide , Thermoluminescence , Ion implantation , ‎Kinetic analysis , ‎Oxygen vacancies , Argon , Irradiation
  • Language: English
  • Type: Master's thesis , text
  • Identifier: http://hdl.handle.net/10962/234220 , vital:50173
  • Description: The influence of argon ion implantation on the thermoluminescence properties (TL) of aluminium oxide (alumina) was investigated. Aluminium oxide (Al2O3) samples were implanted with 80 keV Ar ions. An unimplanted sample and samples implanted at fluences of 1×1014, 5×1014, 1×1015, 5×1015, 1×1016 Ar+/cm2 were irradiated at a dose of 40 Gy and heated at a rate of 1°C/s using a Risø reader model TL/OSL-DA-20 equipped with a Hoya U-340 filter. The thermoluminescence glow curves showed five distinct peaks with main peaks at 178°C, 188°C, 176°C, 208°C, 216°C and 204°C for the unimplanted sample as well as implanted samples. The peak positions of the samples were independent of the irradiation dose suggesting that the samples were characterised by first order kinetics. This was also confirmed by the TM-TSTOP analysis. It was observed that the TL intensity decreases with fluence of implantation. This observation suggests that the concentration of electron traps responsible for thermoluminescence decreases with ion implantation. The decrease in electron concentration might be due to the formation of non-radiative transition bands or the creation of defect clusters and extended defects following the ion implantation and ion fluence increases. The stopping and range of atoms in matter (SRIM) program was used to correlate the TL response of Al2O3 with defects under ion implantation. Subsequent to ion implantation, it was found that the number of oxygen vacancies which are related to electron traps are higher than the number of aluminium vacancies. Kinetic analysis was carried out using the initial rise, Chens peak shape, various heating rate, the whole glow curve, glow curve fitting and the isothermal decay methods. The activation energy was found to be around 0.8 eV and the frequency factor to be of the order 108 𝑠−1 regardless of the implantation fluence. This means that argon ion implantation did not affect the nature of electron traps. The dosimetric features of samples were also investigated at doses in the range of 40 – 200 Gy. Samples generally showed a superlinear response at doses less than 140 Gy and sublinear response at doses higher than 160 Gy. , Thesis (MSc) -- Faculty of Science, Physics and Electronics, 2022
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  • Date Issued: 2022-04-06

Institutional innovations for improved water security in smallholder irrigation schemes in KwaZulu-Natal and Eastern Cape Provinces, South Africa

  • Authors: Phakathi, Sandile
  • Date: 2022-04-06
  • Subjects: Water security South Africa , Rural development projects South Africa , Institutional cooperation South Africa , Irrigation farming South Africa , Food security South Africa , Agricultural innovations South Africa , Irrigation Technological innovations South Africa , Smallholder irrigation schemes‎
  • Language: English
  • Type: Doctoral thesis , text
  • Identifier: http://hdl.handle.net/10962/232341 , vital:49983 , DOI 10.21504/10962/232341
  • Description: Smallholder irrigation schemes are regarded as a key strategy to eliminate poverty and increase food security in rural areas in South Africa. While the South African government has invested heavily in rural development schemes, most irrigation schemes face a myriad of challenges, including deficient infrastructure, weak institutional arrangements and water insecurity. Weak institutions have been identified as a major bottleneck in the performance of smallholder irrigation schemes in developing countries, including South Africa. Two main reasons have been identified for this challenge. Firstly, the agency of the irrigators was ignored during the design of the schemes. Treating farmers as passive rather than active agents resulted in institutional arrangements that were not context-specific, as well as weak farmer commitment to the ownership and management of the schemes, leading to system breakdown. Despite being noble in intention or design, institutions designed by outsiders often fail due to a lack of legitimacy. Secondly, institutions have failed to evolve to cope with dynamic challenges and opportunities in the sector. Stability over a reasonable period is required for institutions to effectively perform their crucial role of establishing reasonable expectations in dealings among people. Institutional innovations are required to keep up with the changing nature of development. In particular, farmer-led institutional innovations have been touted as key to improving the management of water resources in irrigation schemes. Farmer-led institutional innovation refers to a process, in which farmers themselves initiate, establish, and improve institutions based on their context-specific challenges or opportunities. Farmers’ groups are regarded as an important institutional arrangement to reduce transaction costs, improve social networks, and increase livelihood outcomes. However, little is known about the internal dynamics of these farmer groups, how they operate, and whether or not they are inclusive and innovative, as well as what makes certain groups more successful than others. Furthermore, there is a paucity of research on whether these farmer groups embrace institutional innovations to improve water security and strengthen their design principles that are crucial for collective action. It is against this background that this study aimed to examine the internal group dynamics within the farmer groups; determine whether smallholder farmers are capable of implementing institutional innovations that are novel, useful and legitimate; determine the nature of these innovations (incremental or radical) and their role in improving water security. The main theories that underpinned the study were induced institutional innovation theory, collective action theory, random utility theory and Ostrom’s eight design principles. Multistage sampling was used to collect data from 28 farmer groups and 401 irrigators in smallholder irrigation schemes in KwaZulu-Natal (Tugela Ferry and Mooi River) and the Eastern Cape (Qamata and Zanyokwe). Data were gathered by means of focus group discussions, key informant interviews and household surveys. Several empirical tools were employed to analyse the data (descriptive statistics, thematic analysis, logit model, propensity score matching, PCA and OLS). The study found that group membership was associated with higher levels of water access, adoption of inorganic fertiliser, incomes and assets. Group members had an additional four days’ access to water in a month and applied at least 130 kg/ha more inorganic fertiliser than non-group members. Group members also had a higher household income per capita and more assets than non-group members. However, the results revealed a heterogeneous effect among group members, with the benefits varying according to members’ socio-economic characteristics as well as internal group dynamics. The results suggest that organising farmers into groups should be promoted to improve farmers’ access to productive assets such as water, technology adoption and welfare outcomes. However, the study findings also indicate that smaller groups should be promoted, programmes targeted at empowering women should be prioritised, and that it is imperative to invest in improving farmers’ human capital through various training initiatives. The results indicated that farmers could develop and implement institutional innovations that are novel, useful and legitimate. Of the 28 groups, 21 (75%) had implemented institutional innovations in the past three years. Examples of innovations include, among others, the introduction of a secret voting system to improve marginalised people’s participation in decision-making processes, designing daily rotation rosters to reduce conflict, using an attendance register for participation in group activities, and rewarding members according to their participation levels. Most of these innovations were designed to improve the graduated sanction mechanism (22.2%), enhance the penalty system for non-compliance; improve collective action arrangements (27.8%); monitor attendance of group meetings (18.5%); democratise decision making; and ensure equitable water distribution. However, they mainly focused on addressing challenges rather than exploiting opportunities and were largely incremental (94%), involving an adjustment or reinterpretation of rules and regulations. Furthermore, the innovative groups were small in size and were dominated by male farmers. Based on these results, it is recommended that the government should build on the irrigators’ agency to improve the effectiveness and legitimacy of institutional arrangements in irrigation schemes. The findings also suggest that small groups should be actively promoted, while tailored training should be offered based on the groups’ specific needs to improve institutional innovations in the smallholder irrigation sector in South Africa. A positive association was established between belonging to an innovative group and water security, highlighting the importance of institutional innovations in water security. The propensity score matching indicated that water secure irrigators produced an additional 569-622 kg of maize and earned additional income of R2 037.81. The study’s findings suggest that organising farmers into groups is a promising strategy to improve farmers livelihoods and water security. The government and private donors should thus continue to promote the formation and organisation of farmers into groups. The innovative agency of the irrigators should be acknowledged and harnessed to strengthen institutional innovations. The focus should be on strengthening the institutions designed by farmers themselves, as these are locally contextualised and socially embedded, and hence legitimate. It is recommended that small groups should be actively promoted, while tailored training should be offered based on groups’ specific needs to improve institutional innovations in the smallholder irrigation sector in South Africa. , Thesis (PhD) -- Faculty of Commerce, Economics and Economic History, 2022
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  • Date Issued: 2022-04-06

Integrating blockchain and microgrid technology to enable peer-to-peer energy trading: a business process model

  • Authors: Higgs, James
  • Date: 2022-04-06
  • Subjects: Blockchains (Databases) , Peer-to-peer architecture (Computer networks) , Electric power-plants Decentralization South Africa , Microgrids (Smart power grids) South Africa , ‎Energy trading , Business process model‎
  • Language: English
  • Type: Academic theses , Master's theses , text
  • Identifier: http://hdl.handle.net/10962/284559 , vital:56074
  • Description: Traditional centralised energy systems are coming under increasing pressure because of decarbonisation, decentralisation, and digitisation. A lack of energy security and the inability to manage bi-directional electricity flows constitute two of the biggest challenges faced by centralised systems. Furthermore, in South Africa, the country’s energy system remains monopolised with one large utility satisfying most of the country’s electricity demand. This study is motivated by the need to address energy security within such a monopolised market. To redress the problems highlighted above, this study explores how blockchain and microgrid technology can be integrated to enable decentralised energy production and trading in South Africa. As such, this study develops a fully integrated blockchain-based microgrid energy trading system model. The functional requirements of the system are presented in the form of a business process model. Amongst other benefits, an active blockchain-based microgrid energy trading system provides a means to bolster energy security for the systems’ users. A unique aspect of this study’s approach to energy trading is the utilisation of blockchain’s native tokenizing capabilities. Prosumer energy tokens are minted to create a digital currency for local peer-to-peer energy exchange. A commons-rule based approach is adopted for governing energy resources. As such, this study demonstrates that commons-based solutions provide a feasible alternative to market and profit driven trading for organizing local energy exchange. The primary deliverable of this study satisfies the request of various blockchain researchers for blockchain research to focus on holistic conceptualisations, rather than on the minutiae of blockchain technicalities. Eight core functional requirements of a blockchain energy trading system were identified prior to the construction of the process model. The functional requirements were elicited during a scoping review as a part of the secondary data collection process. Expert review was utilised to verify the functional requirements of the blockchain energy trading system. Once the experts were identified, each expert completed a questionnaire with the intention to verify the requirements. The above process constituted the expert review process for the study. Additionally, the syntactic correctness of the business process model was verified by a business process modelling expert. Weber’s Theory of Evaluation constitutes the theoretical underpinning for the evaluation of the system parts. This study contributes the first publicly accessible business process models of a blockchain-based microgrid energy trading system. This study seeks to advance the discussion of a more integrative and cross disciplinary approach concerning blockchain research, particularly as it pertains to microgrid energy trading. , Thesis (MCom) -- Faculty of Commerce, Department of Information Systems, 2022
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  • Date Issued: 2022-04-06

Large and multi scale mechanistic modeling of Diels-Alder reactions

  • Authors: Isamura, Bienfait Kabuyaya
  • Date: 2022-04-06
  • Subjects: Computational chemistry , Diels-Alder reaction , Python (Computer program language) , ‎Reaction force theory , Fullerenes , Diolefins , AMADAR (Automated workflow for Mechanistic Analysis of Diels-Alder Reactions , ONIOM‎
  • Language: English
  • Type: Master's thesis , text
  • Identifier: http://hdl.handle.net/10962/232317 , vital:49981
  • Description: The [4+2] cycloaddition reaction between conjugated dienes and substituted alkenes is known as the Diels-Alder (DA) reaction, in honor of two German chemists, Otto Diels and Kurt Alder, who first reported this marvelous chemical transformation. The DA reaction is one of the most popular reactions in organic chemistry, allowing for the regio- and stereospecific establishment of six-membered rings with up to four stereogenic centers. This pericyclic reaction has found many applications in areas as diverse as natural products chemistry, polymer chemistry, and agrochemistry. Over the past decades, the mechanism of the Diels-Alder (DA) reaction has been the subject of numerous studies, dealing with questions as diverse as the mechanistic pathway, the synchronicity, the use of catalysts, the effect of solvents and salts, etc. On the other hand, as an example, fullerenes (and particularly [60] fullerene) have been found to act as good dienophiles in DA reactions to the extent that many functionalized fullerenes with interesting applications are still synthesized by reacting C60 with dienes. However, despite the very abundant literature about the mechanism of the DA reaction, some pertinent questions have been still pending, including, without being restricted to, the prediction of transition state (TS) geometries and the modeling of DA reactions involving large systems, such as those of C60 fullerene. It must be emphasized that TSs are not easy to predict and the main reason is that many existing algorithms require that the search is initiated from a good starting point (guess TS), which must be very similar to the actual TS. This problem is even more difficult when many TSs are to be located as may be the case in large-scale studies. Moreover, due to the large size of the C60 molecule, the usage of accurate high-level computational methods in the investigation of its reactivity towards dienes is computationally costly, implying the need to find the best threshold between accuracy and computational cost. Therefore, the present study was carried out to contribute to solving the problems of large-scale prediction of DA transition state geometries and the multi-scale modeling of C60 fullerene DA reactions. To address the first problem (large-scale prediction of TSs), we have developed a python program named “AMADAR”, which predicts an unlimited number of DA transition states, using only the SMILES strings of the cycloadducts. AMADAR is customizable and allows for the description of intramolecular DA reactions as well as systems resulting in competing paths. In addition, The AMADAR tool contains two separate modules that perform reaction force analyses and atomic decomposition of energy derivatives from the predicted Intrinsic Reaction Coordinates (IRC) paths. The performance of AMADAR was assessed using 2000 DA cycloadducts and showed a success rate of ~ 95%. Most of the errors were due to basis set inconsistencies or convergence issues that we are still working on. Furthermore, a set of 150 IRC paths generated by the AMADAR program were analyzed to get insight into the (a)synchronicity of DA reactions. This investigation confirmed that the reaction force constant 𝜅 (second derivatives of the system energy with respect to the reaction coordinate) was a good indicator of synchronicity in DA reactions. A close inspection of the profile of 𝜅 has enabled us to propose an alternative classification of DA reactions based on their synchronicity degree, in terms of (quasi)-synchronous, moderate asynchronous, asynchronous, and likely two-steps DA reactions. Natural population analyses seemed to indicate that the global maximum of the reaction force constant could be identified with the formation of all the bonds in the reaction site. Finally, the atomic resolution of energy derivatives suggested that the mechanism of the DA reaction involves two inner elementary processes associated with the formation of each C-C bond. A striking mechanistic difference between synchronous and asynchronous DA reactions emerging from this study is that, in asynchronous reactions, the driving and retarding forces are mainly caused by the fast and slow-forming bonds (elementary process) respectively, while in the case of synchronous ones both elementary processes retard and drive the process concomitantly and equivalently. Regarding the DA reaction of C60 fullerene that was considered to illustrate the problem of multiscale modeling, we have constructed 12 ONIOM2 and 10 ONIOM3 models combining five semi-empirical methods (AM1, PM3, PM3MM, PDDG, PM6) and the LDA(SVWN) functional in conjunction with the B3LYP/6-31G(d) level. Then, their accuracy and efficiency were assessed in comparison with the pure B3LYP/6-31G(d) level considering first the DA reaction between C60 and cyclopentadiene whose experimental data are available. Further, different DFT functionals were employed in place of the B3LYP functional to describe the higher-layer of the best ONIOM partition, and the results obtained were compared to experimental data. At this step, the ONIOM2(M06-2X/6-31 G(d): SVWN/STO-3G) model, where the higher layer encompasses the diene and pyracyclene portion of C60, was found to provide the best tradeoff between accuracy and cost, with respect to experimental data. This model showed errors lower than 2.6 and 2.0 kcal/mol for the estimation of the activation and reaction enthalpies respectively. We have also demonstrated, by comparing several ONIOM2(DFT/6-31G(d): SVWN/STO-3G) models, the importance of dispersion corrections in the accurate estimation of reaction and activation energies. Finally, we have considered a set of 21 dienes, including anthracene, 1,3-butadiene, 1,3-cyclopentadiene, furan, thiophene, selenothiophene, pyrrole and their mono-cyano and hydroxyl derivatives to get insight into the DA reaction of C60 using the best ONIOM2(M06-2X/6-31 G(d): SVWN/STO-3G) model. For a given diene and its derivatives, the analysis of frontier molecular orbitals provides a consistent explanation for the substituent effect on the activation barrier. It revealed that electron-donating (withdrawing) groups such as -OH (–CN) cut down on the activation barrier of the reaction by lowering (extending) of the HOMOdiene – LUMOC60 gap and consequently enhancing (weakening) the interaction between the two reactants. Further, the decomposition of the activation energy into the strain and interaction components suggested that, for a given diene, electron-donating groups (here –OH) diminish the height of the activation barrier not only by favoring the attractive interaction between the diene and C60, but also by reducing the strain energy of the system; the opposite effect is observed for electron-withdrawing groups (here –CN). In contrast with some previous findings on typical DA reactions, we could not infer any general rule applicable to the entire dataset for the prediction of activation energies because the latter does not correlate well with either of the TS polarity, electrophilicity of the diene, or the reaction energy. , Thesis (MSc) -- Faculty of Science, Chemistry, 2022
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  • Date Issued: 2022-04-06

Mediating transition to household electricity conservation through co-designing in Makhanda, South Africa

  • Authors: Mutumbi, Uzziah
  • Date: 2022-04-06
  • Subjects: Households Energy consumption South Africa Makhanda , Renewable energy sources South Africa , Consumer behavior South Africa Makhanda , Energy conservation South Africa Makhanda Citizen participation , Low-income consumers South Africa Makhanda
  • Language: English
  • Type: Academic theses , Master's theses , text
  • Identifier: http://hdl.handle.net/10962/291262 , vital:56838
  • Description: Households consume up to 20% of total global electricity consumption, hence they are important role players in efforts for promoting sustainable consumption. Research on electricity-use behaviour and effectiveness of interventions is important for informing intervention strategies. However, relative to developed countries, research on this subject is lacking in developing countries, where electricity access is limited, and a substantial proportion of households are energy poor. The main goal of this study was to examine reported electricity-use behaviour and the effects of co-designed interventions on household electricity consumption in low-income households in Makhanda, South Africa, using a field-based experiment. Findings from self-reported electricity-use practices showed mixed results, with households reporting both good electricity-use behaviour (e.g., cooling down hot food before refrigeration) and wasteful actions (e.g., leaving appliances on standby). Results showed that electricity-use behaviour was influenced by socio-psychological values including universalism, benevolence, hedonism, and power. Over the intervention period, households exposed to co-designed electricity-saving interventions showed mean electricity savings of about 5.5%, while households in the Partial Treatment and Control group showed increased electricity consumption. Socio-demographic factors such as age and psychological factors (involvement and perceived behavioural control) were very important determinants of household consumption. Broadly, the findings empirically validate the impact of collective problem formulation and co-designing interventions in promoting sustainable actions. , Thesis (MSc) -- Faculty of Science, Environmental Science, 2022
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  • Date Issued: 2022-04-06

Molecular characterization of microbial communities in the Sundays and Swartkops estuaries impacted by anthropogenic activities

  • Authors: Kgomokhumo, Tlhoafalang Evah
  • Date: 2022-04-06
  • Subjects: Microbial ecology South Africa Sundays Estuary (Eastern Cape) , Microbial ecology South Africa Swartkops River Estuary , Estuarine health Effect of human beings on South Africa Sundays Estuary (Eastern Cape) , Estuarine health Effect of human beings on South Africa Swartkops River Estuary , Microorganisms South Africa Sundays Estuary (Eastern Cape) Molecular aspects , Microorganisms South Africa Swartkops River Estuary Molecular aspects , Eutrophication South Africa Sundays Estuary (Eastern Cape) , Eutrophication South Africa Swartkops River Estuary , Algal blooms South Africa Sundays Estuary (Eastern Cape) , Algal blooms South Africa Swartkops River Estuary
  • Language: English
  • Type: Academic theses , Master's theses , text
  • Identifier: http://hdl.handle.net/10962/290994 , vital:56806
  • Description: Anthropogenic activities are of concern in estuarine systems as they are the main source of water degradation. Water pollution in estuaries is indicated by eutrophication and the presence of pathogens and bacterial indicators which affect biodiversity and energy flow. This study focused on two geographically linked estuaries, namely the Sundays and Swartkops Estuaries. The Sundays Estuary is primarily impacted by agricultural activities in the river catchment with increased nutrients levels, particularly of total oxidised nitrogen (TOxN), likely derived from these farming activities. In contrast, the Swartkops Estuary, which is heavily influenced by urban/industrial activities, reflected increased levels of phosphates likely from wastewater and sewage water contamination from residential areas, leaking pipes, and poorly managed sewage treatment plants. The central objective of this study was to assess microbial population profiles and diversity impacted by agricultural activities in Sundays Estuary and industrial/urban-influenced Swartkops Estuary using 16S and 18S rRNA gene metabarcoding. A distinct difference in eukaryotic composition and diversity was evident between the two sampling exercises in 2018 and 2019 in Sundays Estuary. The eutrophication of both the Sundays and Swartkops estuaries was evident in the repeated occurrences of bloom events. In the Sundays Estuary, a bloom of Heterosigma akashiwo was observed in 2018 whilst Cyclotella dominated the estuary in 2019. The Swartkops Estuary exhibited seasonal variation in phytoplankton composition with Bacillariophyceae blooms in the upper reaches of the estuary in summer and increased prevalence of Dinophyceae in spring. Bacterial taxonomic variation was also noted between the two contrasting estuaries. Although members of the Proteobacteria dominated both estuaries, Gammaproteobacteria were in increased abundance in Sundays Estuary while members of Alphaproteobacteria were in high relative abundance in the marine dominated Swartkops Estuary. Members of the Bacteroidetes were the second most abundant bacterial phylum in both estuaries. Bacterial indicators of agricultural anthropogenic impacts identified in Sundays Estuary included members of Sporichthyaceae, Erysipelotrichaceae, Nostocaceae, and NS11-12_marine_group while some taxa such as the Flavobacteriaceae, Cryomorphaceae, and Halieaceae reflected their capability in degrading the phytoplankton bloom biomass present in the estuary. The urban impacts on the Swartkops Estuary was reflected by the contamination of the estuary with potential pathogens including Aeromonas caviae, Vibrio fluvialis, Mycobacterium intracellulare, Vibrio cholerae, and Bacillus cereus. Bacterial community profiles of the major water inflow points into the Swartkops Estuary included members of the Burkholderiaceae, Rhodocyclaceae, Aeromonadaceae, and Arcobacteriaceae which are typically indicative of raw sewage contamination. The Motherwell canal, which runs through informal settlements, was the most polluted input source with high levels of anthropogenic nutrients and pathogenic bacteria. The Chatty river, which also runs through townships, recorded increased nutrient concentrations and low bacterial richness and diversity which was likely due to an Arthrospira bloom at the time of sampling. The overall results of this study identified sources of pollution in Sundays and Swartkops Estuaries and highlighted the impacts of anthropogenic inputs on microbial population profiles and diversity. , Thesis (MSc) -- Faculty of Science, Biochemistry and Microbiology, 2022
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  • Date Issued: 2022-04-06

Motives and barriers to the implementation of renewable energy sources in South African tertiary institutions

  • Authors: Sibindi, Siyangiso
  • Date: 2022-04-06
  • Subjects: Renewable energy sources South Africa , Education, Higher South Africa , Education, Higher Environmental aspects South Africa , Environmental responsibility South Africa , Climate change mitigation South Africa , Sustainable development South Africa
  • Language: English
  • Type: Academic theses , Master's theses , text
  • Identifier: http://hdl.handle.net/10962/284537 , vital:56072
  • Description: Organisations face major challenges to address the exploitation of non-renewable resources and consider management considerations for dealing with climate change. Organisations have been pushed to play a part in their carbon footprints and in curbing climate change. Among these organisations are tertiary institutions that can greatly impact environmental sustainability and address carbon dioxide emissions by embarking on renewable energy technologies. Tertiary institutions play a major role in society by the provision of skilled labour and personnel that are equipped to deal with a range of advancements and challenges. The sustainability of these tertiary institutions has thus been called into question due to the impact they can bring to societies. This research thus aims to identify the motives and barriers to renewable energy adoption in tertiary education institutions. To do this, a literature review was conducted to identify possible motives and barriers to renewable energy adoption. These were then compiled into a questionnaire that was sent to respondents of three different institutions. Respondents were then requested to give feedback on each of the motives and barriers. The respondents were also asked general questions found in literature that addressed the adoption of renewable energy technologies in tertiary institutions. The data was collected using the designed questionnaires. The respondents were able to articulate their perceived barriers and motives to the implementation of renewable energy technologies in tertiary institutions. Data analysis was done using thematic analysis. The results showed that the barriers in the implementation of renewable energy technologies in tertiary institutions were: ‘Cost to Install’, ‘Transition Process’ and ‘Government Policies’. The motives on why educational institutions need to embark on renewable energy projects were found to be ‘Energy Independence’, ‘Cleaner Source of Energy’ and ‘Reduction in Carbon Emissions’. The cost of renewable energy technologies, the process of moving from the Eskom grid, and renewable energy policies that are ambiguous were some factors that were highlighted by respondents on why it is challenging to adopt renewable energies in tertiary institutions. On the other hand, the effects of load shedding currently being experienced in the country and the migration to cleaner sources of energy that cause less harm to the environment, are some of the drivers noted by respondents on why tertiary institutions need to embark on renewable energy technologies. More emphasis needs to be put by stakeholders on tertiary institutions to migrate to cleaner sources of energy, and policies need to be put in place in order to promote institutions to adopt these types of energies. Governments and other role-players need to be visible at all times in addressing energy challenges in tertiary institutions in the wake of the recent load-shedding concerns that have been crippling South Africa. , Thesis (MBA) -- Faculty of Commerce, Rhodes Business School, 2022
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  • Date Issued: 2022-04-06

Pharmacists’ attitudes and perception of using pictograms as a communication tool in practice

  • Authors: Okeyo, Sam Juma
  • Date: 2022-04-06
  • Subjects: Picture-writing South Africa , Communication in public health South Africa , Pharmacists South Africa Attitudes , Health literacy South Africa , Patient education South Africa , Structural equation modeling , ‎Theory of planned behavior
  • Language: English
  • Type: Academic theses , Master's theses , text
  • Identifier: http://hdl.handle.net/10962/290693 , vital:56775
  • Description: Pictograms, when used in conjunction with verbal and written information, are known to be effective in improving comprehension and recall of medicines information and in supporting communication between healthcare professionals and patients. However, pictograms are seldom used in routine pharmacy practice, and little is known about pharmacists’ opinions of pictograms and their intention to possibly incorporate pictograms into routine practice. This study aimed to investigate pharmacists’ opinions relating to pictograms as a communication tool, and, by applying the Theory of Planned Behaviour (TPB), to explore their intention to use pictograms in pharmacy practice as well as the barriers to their use. The quantitative study design involved a two-phase approach. Phase 1 was a descriptive, cross-sectional online national survey of pharmacists. The 70-item, four-section survey was primarily based on the constructs of TPB, which included attitude, intention, subjective norm, and perceived behavioural control. The last survey section recruited pharmacists for a follow-up Phase 2 survey. Following a pilot study, the survey was emailed to all pharmacists registered with the South African Pharmacy Council. Descriptive statistics for survey items were generated. Pearson correlation investigated the correlation between participant characteristics, familiarity with pictograms and use of pictograms in practice. Structural Equation Modelling (SEM) determined if there was a significant relationship between attitude, subjective norm and perceived behavioural control with intention to use pictograms. A total of 426 pharmacists responded to the Phase 1 survey. Most pharmacists were familiar with the term ‘pictogram’; however, over three-quarters of pharmacists had never observed pictograms being routinely used in a pharmacy setting. When presented with pictograms designed for a low health literate population, most pharmacists thought the design and overall look of the pictograms would be easy for most patients in South Africa to understand (71.6 ± 24.0). Two-thirds of pharmacists (65.0 ± 30.6), felt that pictograms should be used for all patient populations. More than 85% of pharmacists agreed that pictograms should be used for dosage instructions, auxiliary or additional information, warnings, and storage instructions. However, fewer (58-68%) felt that indication, side effects and risk communication information should be accompanied by pictograms. Pharmacists demonstrated positive attitudes towards using pictograms in practice (mean = 4.2 ± 0.9; range: 1 - 5), while perceived behavioural control (mean = 3.0 ± 1.2; range: 1 - 5), subjective norm (mean = 3.8 ± 1.0; range 1 - 5) and intention (mean = 3.3 ± 1.0; range 1 - 5) were all neutral. Attitude (β = -0.25, p < 0.117), however, was not a significant predictor of intention while perceived behavioural control (β = -0.83, p < 0.000) presented with a significant negative correlation with intention. Subjective norm (β = 0.57, p <0.000) was the strongest predictor of intention. Scale reliability ranged from 0.770 to 0.865 for the TPB constructs. Phase 2 aimed to expand on, and further investigate Phase 1 findings relating to current and intended pharmacist behaviour and opinions concerning pictogram usage. As Phase 2 looked to investigate issues in greater depth, questions included open-ended response options. The survey link was emailed to all pharmacists who had voluntarily offered to participate in Phase 2. Frequency data for all questions were generated, and content analysis was undertaken for the free-response comments offered by pharmacists. A total of 35 pharmacists responded to the Phase 2 survey. Most pharmacists who routinely used pictograms initiated their use with support from pharmacists’ colleagues (8/12) and their supervisor/manager (6/7). Pharmacists who stated their intention to use pictograms anticipated receiving support from their pharmacists' colleagues (18/23) and manager/supervisor (15/23). All 12 pharmacists who were routinely using pictograms reported a positive effect on patient communication, with almost all having encountered no negative aspects of using pictograms (11/12). Almost all pharmacists intending to use pictograms could foresee benefits from their use (22/23). Misinterpretation of pictograms was a prevalent barrier common to both pharmacists routinely using pictograms and to those intending to use pictograms. Increased workload was regarded as a prevalent barrier only by pharmacists intending to use pictograms. This study was the first national study of pharmacists to investigate their opinion of pictograms and their use and to adopt a theoretical approach to consider pharmacist intention to use pictograms in routine pharmacy practice. Pharmacists generally expressed positive attitudes to pictograms but showed inadequate understanding of pictogram use. Pharmacists using pictograms reported the positive effect of pictograms on their patient communication, whereas those planning to use pictograms could foresee the benefits of using pictograms despite regarding increased workload as a barrier. As the strongest predictor of intention was subjective norm, this construct should therefore be targeted to motivate pharmacists to adopt the use of pictograms. , Thesis (MPharm) -- Faculty of Pharmacy, Pharmacy, 2022
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  • Date Issued: 2022-04-06

Potential running related injury contributors in South African long-distance runners

  • Authors: Jäger, Chloë Rose Laubscher
  • Date: 2022-04-06
  • Subjects: Running injuries South Africa , Long-distance running South Africa , Running Physiological aspects , Running shoes , Biomechanics , Chi-square test , Fisher exact test
  • Language: English
  • Type: Academic theses , Master's theses , text
  • Identifier: http://hdl.handle.net/10962/290943 , vital:56801
  • Description: Running related injuries (RRIs) are a common problem among long-distance runners, with injury rates ranging from 19.4% to 79.3%. Many studies have been done, investigating possible contributors to RRIs however, very few studies have investigated RRIs in South African long-distance runners, a population which may differ from previously studied populations. The current study aimed to build a descriptive profile of South African long-distance runners, as well as to determine associated factors that may contribute to RRIs. In order to do this, a cross-sectional, retrospective study design was employed using a questionnaire which was mostly electronically distributed. The sample consisted of 378 long-distance runners from each province in South Africa (SA). Using the Chi-square analysis and Fisher exact tests, significant associations were established (p<0.05). The current study found that certain RRI variables were associated with specific aspects of the participants’ personal characteristics and demographics, training characteristics, running experience, footwear, and cross training activities. Footwear and training characteristics produced the largest number of significant RRI associations. The findings of the current study could assist future research on RRIs in South African long-distance runners, by informing researchers of potential areas where more in-depth research is needed. In the long term, researchers may be able to narrow down the main contributors to RRI, possibly decreasing RRI rates in the unique population of South African long-distance runners. , Thesis (MSc) -- Faculty of Science, Human Kinetics and Ergonomics, 2022
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  • Date Issued: 2022-04-06

Protecting the right to identity against catfishing

  • Authors: Ndyulo, Lisa Neliswa Latima
  • Date: 2022-04-06
  • Subjects: Catfishing South Africa , False personation Law and legislation South Africa , Torts South Africa , Mass media and publicity South Africa , Social media Law and legislation South Africa , Identity theft Law and legislation South Africa
  • Language: English
  • Type: Academic theses , Master's theses , text
  • Identifier: http://hdl.handle.net/10962/290767 , vital:56782
  • Description: Catfishing is a form of impersonation occurring on social media that interferes with a person’s right to identity. It involves creating a fake profile online using another person’s images. The facets of the right to identity are image, name, and likeness, among others. Catfishing affects a person’s right to identity and human dignity. Hence, the thesis aims to determine whether the right to identity adequately protects individuals against catfishing. This thesis is a desktop analysis considering the South African legal framework related to the right to identity, including the common law, the Constitution of the Republic of South Africa, 1996, and legislation. The thesis is also a comparative analysis assessing the adequacy of addressing catfishing through the right to identity. The study evaluates the right to identity’s adequacy by juxtaposing the South African legal framework with California and Oklahoma’s common law and statutory interventions. The study reveals that the right to identity protects South African social networking website users against catfishing. Like the common law right of privacy in California and Oklahoma, a person infringes the right to identity when they use another person’s identity facets to portray them in a false light, and like the statutory right of publicity in California and Oklahoma, a person infringes identity when they appropriate facets of another person’s identity for commercial gain. The infringement of the right to identity entitles a person to legal remedies, including a claim for damages, among other things. The thesis also considers principles of conflict of laws to determine the operative law in an instance where a victim resides in South Africa and the perpetrator resides in the US, or vice versa. The study recommends that developing the common law to recognise that identity can be infringed by mere appropriation not linked to a commercial purpose would be beneficial for addressing catfishing adequately in South Africa. Legal development contributes to the constitutional imperative to align the common law with society’s shifting needs and address novel legal issues, such as catfishing. , Thesis (LLM) -- Faculty of Law, Law, 2022
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  • Date Issued: 2022-04-06

Rainwater and alternative potable water microbial water quality and DRM implications in Makana Local Municipality

  • Authors: Nhokodi, Tererai
  • Date: 2022-04-06
  • Subjects: Uncatalogued
  • Language: English
  • Type: Master's theses , text
  • Identifier: http://hdl.handle.net/10962/232227 , vital:49973
  • Description: Thesis (MSc (Pharm)) -- Faculty of Pharmacy, Pharmacy, 2022
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  • Date Issued: 2022-04-06

Soil and vegetation recovery following Acacia dealbata clearing in the Tsitsa catchment, Eastern Cape Province of South Africa: implications for ecological restoration

  • Authors: Balintulo, Putuma
  • Date: 2022-04-06
  • Subjects: Acacia South Africa Eastern Cape , Invasive plants South Africa Eastern Cape , Working for Water Programme , Soil restoration South Africa Eastern Cape , Plant nutrients South Africa Eastern Cape , Restoration ecology South Africa Eastern Cape , Clearing of land South Africa Eastern Cape , Legacy effect‎
  • Language: English
  • Type: Academic theses , Master's theses , text
  • Identifier: http://hdl.handle.net/10962/290778 , vital:56783
  • Description: Invasion by alien plant species in South Africa continues to compromise the stability of ecosystems by causing declines in biodiversity, altering soil nutrients and processes, and subsequently transforming ecosystem functionality. Control of invasive alien plant species has been widely implemented in South Africa to minimize their negative impacts; however, the legacy effects can persist long after the plant has been removed. The impacts of Acacia dealbata clearing on soil properties and native vegetation recovery remains understudied despite their significance in ecological restoration and monitoring. This comparative study determined the impacts of A. dealbata clearing on both soil physicochemical properties and vegetation in the Eastern Cape Province of South Africa. Soils were collected from three different clearing treatments, namely, cleared, invaded, and uninvaded, on 5 m x 5 m plots over three summer months. The plots were replicated four times for each clearing treatment, making a total of 72 sampling plots. Soils were assessed for soil pH, resistivity, P, C, N, and exchangeable cations as well as soil moisture content, penetration resistance, infiltration rate, hydraulic conductivity, and water repellency. Clearing of A. dealbata did not have any significant effects on most soil nutrients, however, there were variations in soil pH, resistance, and Na. Soil pH was significantly higher in the uninvaded treatments than in the cleared and invaded treatments. Soil moisture content was significantly higher in the cleared treatments than the adjacent invaded and uninvaded treatments, but this was observed in the month of December only. Soil penetration resistance and infiltration rates were significantly higher in the month of December in the cleared treatments. For all clearing treatments, no significant differences were recorded for soil hydraulic conductivity. These results on changes in soil properties following A. dealbata clearing are varied, with some soil properties showing decreases, an indication that removal of A. dealbata has the potential to shift soil properties towards a positive recovery trajectory. This study further assessed whether the clearing of A. dealbata facilitates the recovery of native plant species. Vegetation surveys were conducted in the three above-mentioned treatments and plots. Results showed little recruitment of native grasses and forbs, but the persistence of A. dealbata seedlings in the cleared treatments. Species richness and Shannon-Wiener diversity index were significantly (P < 0.05) higher in the cleared and invaded treatments than the uninvaded treatments, and this was more visible for trees and shrubs. Cover for all species was significantly higher (P < 0.05) in the uninvaded than the cleared and invaded treatments. This study observed the recruitment of some native species in the cleared treatments that were not present in the invaded treatments. Therefore, the recruitment and establishment of some native species, mostly grasses, in the cleared treatments gives assurance that passive restoration is on a positive vegetation recovery trajectory that can lead to recovery of native vegetation after A. dealbata clearing. Therefore, the study concludes that investing in ecological restoration after alien plant clearing is a necessity for complete ecosystem recovery to be achieved. Overall, the study concludes that the removal of A. dealbata triggers changes to some soil properties. Similarly, the study observed recruitment of some native grasses in cleared areas, an indication that alien plant clearing facilitates changes in both soil properties and vegetation. However, soil and vegetation recovery are being hampered by the regrowth of A. dealbata and secondary invaders that were observed in the cleared treatments. Two key recommendations of this study are (i) clearing follow-up to remove recruiting seedlings of invasive plant species and secondary invaders should be timeous and well-funded, and (ii) active restoration should be considered to speed-up soil and vegetation recovery processes. , Thesis (MSc) -- Faculty of Science, Environmental Science, 2022
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  • Date Issued: 2022-04-06

Statistical and Mathematical Learning: an application to fraud detection and prevention

  • Authors: Hamlomo, Sisipho
  • Date: 2022-04-06
  • Subjects: Credit card fraud , Bootstrap (Statistics) , Support vector machines , Neural networks (Computer science) , Decision trees , Machine learning , Cross-validation‎ , Imbalanced data‎
  • Language: English
  • Type: Master's thesis , text
  • Identifier: http://hdl.handle.net/10962/233795 , vital:50128
  • Description: Credit card fraud is an ever-growing problem. There has been a rapid increase in the rate of fraudulent activities in recent years resulting in a considerable loss to several organizations, companies, and government agencies. Many researchers have focused on detecting fraudulent behaviours early using advanced machine learning techniques. However, credit card fraud detection is not a straightforward task since fraudulent behaviours usually differ for each attempt and the dataset is highly imbalanced, that is, the frequency of non-fraudulent cases outnumbers the frequency of fraudulent cases. In the case of the European credit card dataset, we have a ratio of approximately one fraudulent case to five hundred and seventy-eight non-fraudulent cases. Different methods were implemented to overcome this problem, namely random undersampling, one-sided sampling, SMOTE combined with Tomek links and parameter tuning. Predictive classifiers, namely logistic regression, decision trees, k-nearest neighbour, support vector machine and multilayer perceptrons, are applied to predict if a transaction is fraudulent or non-fraudulent. The model's performance is evaluated based on recall, precision, F1-score, the area under receiver operating characteristics curve, geometric mean and Matthew correlation coefficient. The results showed that the logistic regression classifier performed better than other classifiers except when the dataset was oversampled. , Thesis (MSc) -- Faculty of Science, Statistics, 2022
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  • Date Issued: 2022-04-06

Stock market volatility during times of crisis: a comparative analysis of the conditional volatilities of JSE stock indices during the 2007/08 global financial crisis and COVID-19

  • Authors: Wang, Zixiao
  • Date: 2022-04-06
  • Subjects: Stock exchanges , Johannesburg Stock Exchange , Global Financial Crisis, 2008-2009 , COVID-19 (Disease) Economic aspects , Economic forecasting , Stock exchanges and current events , GARCH model
  • Language: English
  • Type: Academic theses , Master's theses , text
  • Identifier: http://hdl.handle.net/10962/284603 , vital:56078
  • Description: This research analyses the comparative behaviour of stock market volatility during two crises. The goal of this research is to determine whether assumed cyclical and defensive sectors have either retained or revealed their expected properties during both the Global Financial Crisis (GFC) and COVID-19 by analysing sectoral volatility amid these two crises. Understanding how volatility changes amid crises helps to determine whether the volatility assumptions of diversified investment portfolios for both defensive and cyclical sectors still held given the different causes of each crisis. In turn, this knowledge can assist with risk management and portfolio allocation in stock market investments. The study can also contribute towards the enhancement of financial markets’ resistance against systemic risks through portfolio diversification, and aid government decision-making targeted at tackling the weaknesses of different economic sectors especially in times of overall economic weakness. This research makes use of the GARCH model to analyse a group of daily time series that consists of eleven sectoral indices and one benchmark index, all based on the South African stock markets. These observed series are categorised into two full sample periods, one designated to the Global Financial Crisis (January 2006 to May 2009) and the other for COVID-19 (January 2018 to May 2021). These are further divided into two sets of sub-sample periods, each made up of a pre-crisis and during-crisis. Furthermore, the dummy variables representing the occurrence of structural breaks are inserted into the full sample periods’ conditional variance equations. This is aimed at capturing the asymmetrical impact of the crises themselves on all observed series. Based on the movement of volatility persistency from pre-crisis to during-crisis for both crises, the results show that, firstly, Health Care and Consumer Goods are considered defensive Sectors. Secondly, Banks, Basic Materials, Chemicals, Telecommunications, and Financials are considered cyclical Sectors. Thirdly, Automobiles & Parts, Consumer Services, and Technology are considered indeterminable Sectors due to the inconsistent behaviour of these sectors’ volatility persistency throughout the sub-sample periods of both crises. Overall, according to the average volatility persistency, the observed series for COVID-19’s full sample period are generally less volatile than those of the GFC. However, the sub-sample periods suggest that the observed series for both pre-crisis and during-crisis periods of COVID-19 are more volatile than those same sub-samples of the Global Financial Crisis. Being able to analyse the characteristics of stock market sectors is crucial for risk management and optimal portfolio allocation of stock market investments. This can be achieved through portfolio diversification by investing in a variety of stocks, both cyclical and defensive, and adjusted over time based the needs of stock market investors. Diversified portfolios do not only serve the interests of individual investors, but can also enhance the financial markets’ overall resistance against systemic risks. , Thesis (MCom) -- Faculty of Commerce, Economics and Economic History, 2022
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  • Date Issued: 2022-04-06

The assessment of degradation state in Ecological Infrastructure and prioritisation for rehabilitation and drought mitigation in the Tsitsa River Catchment

  • Authors: Mahlaba, Bawinile
  • Date: 2022-04-06
  • Subjects: Environmental degradation South Africa Eastern Cape , Restoration ecology South Africa Eastern Cape , Climate change mitigation South Africa Eastern Cape , Droughts South Africa Eastern Cape , South African National Biodiversity Institute , Sustainable development South Africa Eastern Cape , Watersheds , Ecological Infrastructure (EI)‎ , ‎Tsitsa River Catchment
  • Language: English
  • Type: Master's theses , text
  • Identifier: http://hdl.handle.net/10962/202138 , vital:46470
  • Description: Ecosystem degradation is a serious concern globally, including in South Africa, because of the potential adverse impacts on food security, livelihoods, climate change, biodiversity, and ecosystem services. Ecosystem degradation can result in flow alteration in the landscape through changes in the hydrological regime. The study adopts the South African National Biodiversity Institute (SANBI) Framework of Investing in Ecological Infrastructure (EI) to prioritise the restoration of degraded ecosystems and maintain ecosystem structures and functions. This study aims to assess how EI (specifically wetlands, grassland, abandoned cultivated fields, and riparian zone) can facilitate drought mitigation: to assess land degradation status and identify priority EI areas that can be restored to improve the drought mitigation capacity. Two assessment methods were used in this study. Firstly, the Trends.Earth tool was used to assess degradation and land cover change from the year 2000-2015 in Tsitsa catchment, through assessment of Sustainable Development Goal degradation indicator (SDG15.3.1) at a resolution of 300 m. The degradation indicator uses information from three sub-indicators: Productivity, Landcover and Soil Organic Carbon to compute degraded areas. The degraded areas need to be restored and rehabilitated to maintain the flow of essential ecosystems services provided by EI. The second assessment used the Analytical Hierarchy Process (AHP), which integrates stakeholder inputs into a multi-criteria decision analysis (MCDA). The AHP is a useful decision support system that considers a range of quantitative and qualitative alternatives in making a final decision to solve complex problems. As part of the AHP analysis, participatory mapping using Participatory Geographic Information System was conducted to obtain stakeholder inputs for prioritising restoration of the key EI categories (wetlands, grassland, abandoned cultivated fields, and riparian zone) in the catchment. During the participatory mapping, communities prioritised the key EI based on three criteria: (1) ecosystem health, (2) water provisioning and (3) social benefits. The AHP method was used in ArcGIS to prioritise suitable key EI restoration areas with high potential to increase water recharge and storage, contribute to drought mitigation and ecosystem services for the catchment. The prioritisation of EI for community livelihoods in the AHP analysis included all three main criteria. In comparison, the prioritisation of suitable key EI restoration areas for flow regulations was based on two criteria: ecosystem health and water provisioning. The land degradation indicator showed that approximately 54% of the catchment is stable, 41% is degraded land, and 5% of the area has improved over the assessment period (15 years). The degradation status in the EI suggests that more than half (>50%) of each EI category is stable, but there are areas showing signs of degradation, including 43% of grasslands degraded and 39% of wetlands, cultivated lands, and riparian zones also degraded. Degradation is dominant in the upper (T35B and T3C) and lower (T35K, T35L and T35M) parts of the catchments. The three criteria used by the stakeholders in the prioritisation process of the key EI were assigned 12 spatial attributes (the catchment characteristics about the study area in relation to the criteria) to indicate relevant information needed for selecting suitable restoration areas to enhance flow regulation. The AHP analysis results identified approximately 63% (17,703 ha) of wetlands, 88% (235,829 ha) of grasslands, 78% (13,608 ha) of abandoned cultivated fields and 93% (3,791 ha) of the riparian zones as suitable areas for restoration to mitigate drought impact through flow regulation. Also, the suitability results showed 63% (17,703 ha) of wetlands, 58% (2,203 ha) of riparian zones, 68% (11,745 ha) of abandoned cultivated fields and 46% (122,285 ha) of grasslands as suitable restoration areas for improving ecosystem services for community livelihoods. The AHP analysis identified more than 39-43% (of the degraded EI indicated by the Trends.Earth analysis) areas that are suitable for restoration, because key EI plays a significant role in flow regulation and people’s livelihoods, especially when they are managed, maintained, and restored to good health conditions. Therefore, the prioritized EI areas should be either maintained, managed, rehabilitated or restored. The major distinct causes of land degradation are woody encroachment in grasslands, invasion of alien plants on abandoned cultivated fields and soil erosion in the catchment. The most suitable EI areas recommended for restoration are those natural resources near local communities, which provide essential ecosystem services to sustain their livelihood. Therefore, degraded EI in the T35 catchments should be restored and maintained to improve livelihood and mitigate drought impacts. The study pointed out how the key selected ecological infrastructure can help mitigate the impacts of droughts and improve human livelihood. The study contributes towards the important concept of investing in ecological infrastructure to improve the social, environmental, and economic benefits. , Thesis (MSc) -- Faculty of Science, Institute for Water Research, 2022
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  • Date Issued: 2022-04-06

The biology and movement patterns of non-native common carp, cyprinus carpio (l) in Groenvlei, South Africa

  • Authors: Mukhari, Dinah Lorraine
  • Date: 2022-04-06
  • Subjects: Carp South Africa Goukamma Nature Reserve , Introduced fishes South Africa Goukamma Nature Reserve , Carp Behavior South Africa Goukamma Nature Reserve , Carp South Africa Goukamma Nature Reserve Growth , Carp Habitat South Africa Goukamma Nature Reserve , Carp South Africa Goukamma Nature Reserve Reproduction , Habitat conservation South Africa Goukamma Nature Reserve , Aquatic resources conservation South Africa Goukamma Nature Reserve
  • Language: English
  • Type: Academic theses , Master's theses , text
  • Identifier: http://hdl.handle.net/10962/291233 , vital:56834
  • Description: The common carp, Cyprinus carpio is a highly invasive fish species, first introduced into South Africa in the late nineteen century, and now widely spread throughout the country. In 1991 carp were illegally introduced to Groenvlei, within the Goukamma Nature Reserve in the Western Cape Province. Decreases in water quality and declines in biota have been attributed to the now large numbers of carp. Management measures have commenced to reduce the carp population, however these are not underpinned by science as little is known about the biology and movement patterns of resident carp. The age, growth and maturity of carp within the lake was determined using oxytetracycline hydrochloride marked asteriscus otoliths and macroscopic gonad development staging methods. The results showed that carp in Groenvlei had similar growth characteristics to the invasive populations in North America and Australia; fast growth during the first three to five years and reproductive maturity attained between the ages of two to three years, and are long lived (maximum age of 20 years old). Their growth however differed from the only other study on a South African population. Six acoustically tagged carp were manually tracked in order to report on their movement patterns and habitat use. Carp moved much greater distances in February compared to October and November, and occupied different areas of the lake. In November they were found to aggregate in backwaters which corresponds with their breeding activities. Literature on global carp control shows that whilst eradication of this fish can be achieved in small isolated waters using icthyocides and water drawdowns, in conservation priority areas such as Groenvlei where this is not possible, mechanical removal using multiple gears targeting vulnerable life stages can most efficient at controlling carp. This study identified where and when these methods could be focused to optimise control efforts. , Thesis (MSc) -- Faculty of Science, Ichthyology and Fisheries Science, 2022
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  • Date Issued: 2022-04-06
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