Modifcations to gravitational waves due to matter shells
- Authors: Naidoo, Monogaran
- Date: 2021-10-29
- Subjects: Gravitational waves , General relativity (Physics) , Einstein field equations , Cosmology , Matter shells
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/191118 , vital:45062 , 10.21504/10962/191119
- Description: As detections of gravitational waves (GWs) mount, the need to investigate various effects on the propagation of these waves from the time of emission until detection also grows. We investigate how a thin low density dust shell surrounding a gravitational wave source affects the propagation of GWs. The Bondi-Sachs (BS) formalism for the Einstein equations is used for the problem of a gravitational wave (GW) source surrounded by a spherical dust shell. Using linearised perturbation theory, we and the geometry of the regions exterior to, interior to and within the shell. We and that the dust shell causes the gravitational wave to be modified both in magnitude and phase, but without any energy being transferred to or from the dust. This finding is novel. In the context of cosmology, apart from the gravitational redshift, the effects are too small to be measurable; but the effect would be measurable if a GW event were to occur with a source surrounded by a massive shell and with the radius of the shell and the wavelength of the GWs of the same order. We extended our investigation to astrophysical scenarios such as binary black hole (BBH) mergers, binary neutron star (BNS) mergers, and core collapse supernovae (CCSNe). In these scenarios, instead of a monochromatic GW source, as we used in our initial investigation, we consider burst-like GW sources. The thin density shell approach is modified to include thick shells by considering concentric thin shells and integrating. Solutions are then found for these burst-like GW sources using Fourier transforms. We show that GW echoes that are claimed to be present in the Laser Interferometer Gravitational-Wave Observatory (LIGO) data of certain events, could not have been caused by a matter shell. We do and, however, that matter shells surrounding BBH mergers, BNS mergers, and CCSNe could make modifications of order a few percent to a GW signal. These modifications are expected to be measurable in GW data with current detectors if the event is close enough and at a detectable frequency; or in future detectors with increased frequency range and amplitude sensitivity. Substantial use is made of computer algebra in these investigations. In setting the scene for our investigations, we trace the evolution of general relativity (GR) from Einstein's postulation in 1915 to vindication of his theory with the confirmation of the existence of GWs a century later. We discuss the implications of our results to current and future considerations. Calculations of GWs, both analytical and numerical, have normally assumed their propagation from source to a detector on Earth in a vacuum spacetime, and so discounted the effect of intervening matter. As we enter an era of precision GW measurements, it becomes important to quantify any effects due to propagation of GWs through a non-vacuum spacetime Observational confirmation of the modification effect that we and in astrophysical scenarios involving black holes (BHs), neutron stars (NSs) and CCSNe, would also enhance our understanding of the details of the physics of these bodies. , Thesis (PhD) -- Faculty of Science, Mathematics (Pure and Applied), 2021
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- Date Issued: 2021-10-29
A framework to integrate social entrepreneurship into development planning in South Africa
- Authors: Nwauche, Sokeibelemaye
- Date: 2021-04
- Subjects: Gqeberha (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/52982 , vital:44881
- Description: The thesis presents a framework to integrate social entrepreneurship (SE) into development planning in South Africa. Even though there is no consensus on a universally accepted definition of the term, there is concurrence that SE brings about social change that can influence the overall development of the community. In South Africa, SE is thus conceived of as one of the mechanisms for addressing the wicked and persistent socio-economic challenges that face the country. Social entrepreneurship occurs in areas such as education, health, skills development, youth programmes, rehabilitation, safety, food security, poverty, job creation, human rights activism, environmental issues, arts and culture, among others. However, it remains unclear how SE is integrated into the development planning and implementation processes. Questions of integrating SE into development planning are asked within the context of South Africa as a democratic developmental state that intervenes in the development process. It emphasises the mobilization of and engagement with all sectors towards the achievement of its development objectives as articulated in the national development plan (NDP). Also, government recognizes organizations in the social enterprise sector (such as NPOs and NPCs) as stakeholders and development partners who deliver relevant services towards the achievement of these development objectives. However, there is a lack of framework to mobilize and integrate the social enterprise sector and SE into the development planning process. Social entrepreneurship, therefore, tends to occur in insolation from other development programmes. , Thesis (PhD) -- Faculty of Business and Economic Sciences, School of Economics, Development and Tourism, 2021
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- Date Issued: 2021-04
A Functional Data Analysis approach to understand patterns imbedded within various data types
- Authors: Mangisa, Siphumlile
- Date: 2021-04
- Subjects: Gqeberha (South Africa) , Eastern Cape (South Africa) , Data mining
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/52091 , vital:43426
- Description: The thesis investigates the use of the novel Functional Data Analysis (FDA) methods in tackling various data types. Strong motivation is provided for the use of interesting opportunities offered by FDA to analyse not only economic data, but generally, data from any domain. The use of these methods is illustrated using three unique self-contained case-studies from econometrics. , Thesis (PhD) -- Faculty of Science, School of Computer Science, Mathematics, Physics and Statistics, 2021
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- Date Issued: 2021-04
A theoretical study of alkoxyl radical and radical cation mediated cyclisation reactions in unsaturated alkanols
- Authors: Lee, Peter Mattison Clarke
- Date: 2021-04
- Subjects: Gqeberha (South Africa) , Eastern Cape (South Africa) , Density functionals
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/52130 , vital:43430
- Description: A large part of this computational study focussed on selectivity patterns for 4-penten- 1-oxyl radical 1,5- and 1,6-cyclisations and for those of analogous 5-hexenyl, 4- penten-1-aminyl, 4-penten-1-iminyl and 3-phenylpropan-1-oxyl radicals. The study furthermore included cyclisation reactions of the radical cations of 4-penten-1-ol and 3-phenylpropan-1-ol. Calculations were performed for all applicable species involved in the two cyclisation modes studied, i.e. 1,5- and 1,6-cyclisation. These species included radical and radical cation precursors, as well as relevant radical transition state structures and radical adducts. All cyclisation systems investigated used the Density Functional Theory (DFT) functional B3LYP with a combination of eight basis sets. Each basis set used was a progressively higher level of theory than B3LYP/6-31G* which was used as a starting point. Cyclisations for unsubstituted species, e.g. the 4-penten-1-oxyl radical 1,5- and 1,6-cyclisations, were also simulated using the ωB97X-D and ωB97X-V functionals which account for dispersive effects. The same set of eight basis sets were used with these two functionals. , Thesis (PhD) -- Faculty of Science, School of Computer Science, Mathematics, Physics and Statistics, 2021
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- Date Issued: 2021-04
An exploration into an ESD-based teaching strategy to improve the critical thinking and problem-solving skills amongst development studies students at Nelson Mandela University
- Authors: Abrahams, Andre John
- Date: 2021-04
- Subjects: Sustainable development -- Study and teaching , Universities and colleges -- South Africa , Critical thinking
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/50906 , vital:43149
- Description: In recent years, Education for Sustainable Development (ESD) has been a significant focus for research pertaining to teacher education and transformative approaches to teaching and learning. However, there has been less specific focus on the implementation of ESD in the context of higher education. This study, therefore, explored the use of an ESD-based teaching and learning approach in an undergraduate Development Studies programme. The focus was on developing a teaching approach that was informed by the principles of ESD and which could assist Development Studies lecturers in creating a more transformative, student-centred environment. This study was a qualitative undertaking, conducted at the Nelson Mandela University’s (NMU) Development Studies undergraduate programme. The ESD-based approach was implemented by two participating lecturers who utilised the approach across four undergraduate classes. Qualitative data were generated through a systematic literature analysis (SLA), exploratory interviews, student exercises and assessments, focus group discussions, and reflective journal entries. The gathered data were then analysed using a framework analysis rubric adapted from the theoretical framework utilised in the study. In addition, the data were coded using the six coding techniques promoted by Saldaña (2013). The findings suggest that the ESD-based approach developed in the study could effectively contribute towards promoting ESD in the Development Studies programme. The findings also suggest that, when properly implemented, the ESD-based approach could assist lecturers in creating a more transformative learning environment where students have greater control over their learning experience. In addition, this study found that students in the selected Development Studies undergraduate programme could benefit from continued exposure to the teaching methods and techniques adopted in the approach. The implementation of the approach also uncovered some of the inhibiting factors that may prevent an ESD-based approach being mainstreamed into the context of higher education. , Thesis (DPhil) -- Faculty of Business and Economic Sciences, Development Studies, 2021
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- Date Issued: 2021-04
Comparison of behaviour between traditional male circumcision initiates of the yesteryears and those of the contemporary epoch in Cala and Mdantsane, Eastern Cape
- Authors: Mpateni, Aphiwe https://orcid.org/0000-0002-6823-9179
- Date: 2021-04
- Subjects: Circumcision , Xhosa (African people) -- Rites and ceremonies
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/22045 , vital:51968
- Description: Unequivocally, the traditional male circumcision as rite of passage in South African communities has been embraced for its role in shaping the behaviour among the initiates. This rite was highly valuable during the yesteryears as the traditional male circumcision initiates portrayed compliance with the society’s moral codes and cultural goalposts. Inopportunely, on the other hand, during the contemporary epoch this rite of passage and the cultural underpinnings embedded in it appear to be eroding and shifting from the initial purpose of inculcating good behaviour and morals. This study seeks to compare the behaviour of the yesteryears’ traditional male circumcision initiates and those of the contemporary epoch in Cala, Sakhisizwe Local Municipality and Mdantsane, Buffalo City Municipality in Eastern Cape. This study aimed to achieve the following objectives: (i) to explore the policy differences informing TMC practices in yesteryears and in the contemporary epoch; (ii) to identify the similarities and differences between the behaviour of the contemporary initiates and those of yesteryears; and (iii) to establish the environmental factors motivating the change of the behaviour apparent among the contemporary initiates as well as those of the yesteryears. This study is underpinned by the socio- cultural perspective, anomie theory, and social learning theory. Methodologically, this study was qualitative in nature, where the data was collected through one-on-one in-depth interviews, focus group discussions, and Key informants interviews. An interview guide with open-ended questions was used to collect the data. A sample size of forty (40) participants was purposively selected for interviews. The data collection process was cross- sectional in design. Content analysis was employed to analyze the data and findings were presented thematically. The study established policy differences informing TMC during the yesteryears and the contemporary epoch, in that the yesteryears’ policy environment was culturally grounded; while the contemporary one’s is informed by the current national constitution and human rights perspectives. In relation to the policy issues, the study further established elements of illusionary interpretation of rights by the contemporary TMC initiates; poor implementation of policy guiding TMC practice. Further, the study revealed behavioural and morality differences between the yesteryears’ and the contemporary TMC initiates. For instance, the yesteryears’ TMC initiates were reported to be more responsible and well- mannered as compared to the contemporary ones. The shortfalls in expected behaviour and morality for the contemporary TMC initiates were attributed to modernization, and education in the contemporary initiation schools, which does not meet the societal expectations. On the environmental factors motivating the change of behaviour of the TMC initiates; Yesteryears’ TMC initiates complying with moral codes and cultural goalposts; Non-compliance to the moral codes and cultural goalposts by the contemporary TMC initiates; Culture of alcoholism during the contemporary epoch. Based on these findings, this study recommends that the government of South Africa should augment the existing TMC policies to ensure that traditional male circumcision as rite of passage achieves its socio-cultural objective of shaping behaviour and morals. The study further recommends training for traditional nurses “amakhankatha” and traditional surgeons “iingcibi”; and hosting cultural events for cultural resuscitation. The conclusions of this study state that the government must work hand in hand with cultural custodians to ensure that traditional male circumcision practice shapes good behaviour and morals of the initiates. This is because glaring gaps associated with the rite. , Thesis (PhD) -- Faculty of Social Sciences and Humanities, 2021
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- Date Issued: 2021-04
Contract compliance in procuring and disposing entities (PDES) in state departments in Uganda: subtitle if needed. If no subtitle follow instructions in manual
- Authors: Babirye, Hamidah
- Date: 2021-04
- Subjects: Communication , Records -- Management , Public contracts -- Uganda
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/50933 , vital:43173
- Description: Contract compliance has continuously played a vital role in the development of nations globally. It is important, because it enhances the efficiency and success of projects; ensures value for money; mitigates risks and saves a considerable amount of time and resources. Despite its importance, projects continue to fail due to poor communication, untimely deliveries, poor quality deliveries and the lack of a suitable compliance environment. This study helped to address the aforementioned challenges by creating an enabling environment for contract compliance in procuring and disposing entities (PDEs) in state departments in Uganda. The purpose of this study was to determine the enabling factors necessary for contract compliance and how it can be effectively used to assist PDEs in the Ugandan context. This purpose was achieved through a qualitative research approach that provided insights into the need for contract compliance among PDEs and the perceptions thereof; the contract compliance processes; challenges associated with contract compliance and the factors to be considered when creating an enabling environment for contract compliance. Data was gathered from telephonic interviews with twenty one participants and focus group discussions via the Zoom online platform with eight participants, bringing the total number of participants to twenty nine. Participants included auditors, accounting officers, heads of finance departments, heads of procurement departments and procurement officers. Data was collected using an interview guide and analysed by means of content and thematic analyses. A conceptual framework for creating a suitable environment for contract compliance in PDEs was developed. Findings indicate that the critical factors for creating an enabling environment include: communication; reporting; records management; institutional structure; compliance checks; enforcement; a legal and regulatory framework; and evaluation. Other factors include: stakeholder involvement; contract management; funding; openness; ethical orientation; and capacity building. The proposed conceptual framework serves as a valuable resource for researchers and practitioners, especially those involved in public procurement. , Thesis (DPhil) -- Faculty of Business and Economic Sciences, Business Management, 2021
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- Date Issued: 2021-04
Descriptive analysis of organic farming systems and factors affecting adoption and disadoption in Zambia : a case study
- Authors: Munthali, Robert
- Date: 2021-04
- Subjects: Gqeberha (South Africa) , Eastern Cape (South Africa) , Organic farming -- Zambia
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/52111 , vital:43434
- Description: The last 30 years since the early 1990s has seen the heightened promotion of organic farming as a sustainable farming option in Zambia. The main objectives of this research study were to carry out an analysis of organic farming systems in order to understand factors affecting adoption, as well as reasons why some organic farmers discontinue using the approach. The study involved four districts in Zambia: Mazabuka, Chikankata, Lusaka and Chongwe. Specifically, the research investigated challenges and limitations of organic agronomic practices, and analysed factors that influence adopters and disadopters of organic agriculture. Primary data were collected through interviews and by administering semi-structured questionnaires. The research population comprised approximately 250 farmers adopters and disadopters, with the sample size being 50 farmers chosen across four districts using systematic random sampling methods. Additionally, five observation research field trials were conducted in order to gather practical data on individual farmer’s crop management practices. Farmers adopting and maintaining organic methods reported several reasons for embracing the system, some of which are: organic farming is regenerative; it is environmentally responsible; it uses manure, believed to help build healthy soils rich in organic matter with better nutrient and moisture holding capacity; pesticides and synthetic fertilizers are not used, reducing the levels of toxic residues in organic products which ultimately promotes health. Labour constraints, pest and disease challenges and weed problems were some of the reasons for disadoption. Data showed that disadopters had lower education (48% had primary education), were older and with slightly more children. Although there were more women adopting organic agriculture compared to men, the difference was small 56% and 44% women and men respectively. Among disadopters there were more women (67%) compared to men (33%). Overall, the study results suggest that promotion of organic agriculture should be encouraged through liaison with government departments such as the Zambian Department of Agriculture to include organic agriculture when developing policies. In general, organic farmers have positive opinions concerning the benefits resulting from organic agriculture. Organic farmers should enjoy equal opportunities to conventional agriculture in the provision of extension services, input support, infrastructural development, access to financial resources to procure farm machinery, and equipment and most important of all, they should get fair prices for their organic produce and products. , Thesis (PhD) -- Faculty of Science, School of Environmental Sciences, 2021
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- Date Issued: 2021-04
Ecosexual digital war machines: minoritarian environmental desires in the age of new media
- Authors: Weideman, Lisa
- Date: 2021-04
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/54828 , vital:47915
- Description: Today the (Transnational) State Apparatuses of neoliberal capitalism, ranging from educational institutions to mass media and financial institutions, have effectively created and channelled desires towards consumerism, predicated on resource-extractive practices, within the context of what Gilles Deleuze calls societies of control. This control has also intensified in the digital era, particularly through Internet-based technologies which provide increasingly efficient platforms for the escalation of commodification – ironically, despite the reality of ecological crisis being precipitated by the related extractive practices to the point where it now threatens the continued existence of life on earth. , Thesis (MA) -- Faculty of Humanities, School of Language, Media and Communication, 2021
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- Date Issued: 2021-04
Flash floods prediction in South African urban areas: Jukskei river catchment as case study
- Authors: Mawasha, Tshepo Sylvester
- Date: 2021-04
- Subjects: Gqeberha (South Africa) , Eastern Cape (South Africa) , Geographic information systems
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/52059 , vital:43429
- Description: This study explored the change relation of multi-temporal land-use/land-cover (LULC) conditions in order to determine how they contribute to change in surface runoff volumes and peak discharge, in an effort to predict flash flooding within the Jukskei River catchment. The research is divided into three main parts: (1) LULC change modeling, (2) rainfall-runoff modeling, and (3) flash floods prediction. Three multi-temporal satellite images of Landsat-5 MMS (1987), Landsat-5 TM (2001) and Landsat-8 OLI (2015) were used for LULC modeling. The analysis of the LULC model revealed that there is a continuous increment in built-up area, from 37.7% to 56.2%, in the expense of other LULC classes for the 28-years preceding this study (i.e., 1987 to 2015). Rainfall-runoff model output results revealed that, for these 28 years, there has been an increase in surface runoff due to change in LULC by 21.5%, 32.9% and 45.5% for 1987, 2001 and 2015, respectively. Due to an increase in surface runoff volume and impervious surface over time, the analysis of HEC-RAS/GeoRAS showed that floodplain extent, flood depth, flood velocity, depth-velocity and the level of damage increases especially in low elevation areas and areas at closed proximity to the Jukskei River. Thus, the building structures and infrastructures are at risk of being affected by flash floods during the rainy season. The findings of this study are expected to be used as basic data for the identification of causative factors of flash floods, areas that generate high surface runoff volume, and the prediction of flash floods within the catchment in future. The flood damage maps developed in this study will be useful to policy-makers and the relevant authorities, as well as to local residents, in finding suitable measures for residential development along the floodplain while reducing flood risk in the study area. , Thesis (PhD) -- Faculty of Science, School of Environmental Sciences, 2021
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- Date Issued: 2021-04
Fragmentation of the Albany Thicket Biome: consequences for the biodiversity and health of thicket vegetation
- Authors: Carvalho, Shandon Luke
- Date: 2021-04
- Subjects: Gqeberha (South Africa) , Eastern Cape (South Africa) , Fragmented landscapes
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/52344 , vital:43599
- Description: The dense impenetrable vegetation of the Albany Thicket Biome is highly resistant to a wide variety of disturbances but, once disturbed, lacks the regenerative qualities that allow it to return to a stable state. Agricultural development is the main cause of degradation in this biome, creating a landscape consisting of patches of thicket vegetation scattered throughout land cleared for crops or transformed through grazing by domestic livestock. The main objective of this study is to determine the health, status and biodiversity of thicket fragments as it relates to elephant impacts. The level of fragmentation and the remaining extent of intact thicket were investigated as its current status is unknown. The findings suggest that the Thicket Biome is highly fragmented as almost 50% of solid thicket has been cleared, transformed or degraded by agricultural or urban development. For Arid Thicket, the level of fragmentation and the remaining extent of intact thicket could not be determined and both could potentially be greater. For the intact thicket of Dune, Mesic and Valley Thicket types, patch sizes ranged between almost 6 and 876 km2 while the weighted mean was between 2 and 251 km2 . Remote sensing methods (NDVI) were used to determine whether the health of thicket could be remotely assessed. The thicket within and beyond the extent of piospheres around watering holes is subjected to different levels of herbivory. These different levels were compared to corresponding NDVI values with the latter accurately measuring the impact of herbivores along a gradient and providing a method to assess the health of thicket vegetation. Ground surveys of the edge effect, along thicket fragments adjacent to open pastures and separated by cut lines, were conducted. Based on these surveys, the extent of the edge effect was established at a distance of 7 m into thicket fragments separated by cut lines but could not be determined for thicket fragments adjacent to open pastures. Ground surveys were also conducted to assess the health of thicket vegetation exposed to different levels of herbivory, including the impact of elephants (Loxodonta africana). Results showed that different elephant densities produced different levels of impact that could be described in terms of changes in species richness, species diversity, plant height and cover, and growth form composition. Lastly, the findings of the health-based assessments were combined with elephant densities to develop a model that could assess the health of thicket vegetation using a range of ecological variables and relate it to an ideal range of elephant densities. This assessment method was tested at the Addo Elephant National Park and results showed that an elephant density of 1 elephant/km2 would maintain the appropriate diversity, structure and composition of thicket. , Thesis (MSc) -- Faculty of Science, Department of Botany, 2021
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- Date Issued: 2021-04
Large mammalian fauna of the Palaeo-Agulhas Plain: predicting habitat use and range distribution
- Authors: Brooke, Christopher F
- Date: 2021-04
- Subjects: Gqeberha (South Africa) , Eastern Cape (South Africa) , Herbivores
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/52332 , vital:43590
- Description: Understanding the variations in structure and abundance of animals and what leads to their distribution within the landscape has captured the attention of ecologists for centuries. Importantly, knowledge of current behaviour of large mammals can be used to inform historic population dynamics and is essential to understanding how early humans used large mammals as a foraging resource. Central to this thesis and improving our understanding of large herbivores is the Palaeo-Agulhas Plain (PAP) where large mammalian herbivores formed a key food resource for early humans. The PAP, now submerged off the southern Cape of South Africa, formed a novel ecosystem during lower sea levels. Characterised by large expanses of nutrient rich grasslands and large grazing herbivores, the PAP stands in stark contrast to the nutrient poor fynbos ecosystems that is in the southern Cape today. In this thesis I focus on the Last Glacial Maximum (LGM; ~20 ka) when the PAP was last fully exposed to answer questions relating to the habitat use and range distribution of large herbivores. Importantly, through the Paleoscape Project, modelled climate, soil and vegetation have made these recreations of large mammals possible. Using modelled climate and vegetation this thesis aims to model the large herbivore communities and understand the influence of early humans on the PAP during the LGM for successful integration into the PaleoscapeABM (the PAP agent-based model). To improve our understanding of large mammals on the PAP I identified five large herbivores that became extinct on the PAP since the LGM and modelled their behavioural and physical traits using k-Nearest Neighbour imputation. I predicted the biomass of large herbivores across the PAP using actual biomass of large herbivores from 39 protected areas across South Africa (spanning five functional groups to include the extinct species) across a rainfall gradient and different biomes. The distribution of large herbivores would likely have been driven by similar top-down and bottom-up drivers we see in large herbivore ecology today. Knowing this, I created a predictive model for large mammals by predicting the probability of occurrence of functional groups of large herbivores in relation to environmental drivers and humans. Results showed that all species (except Antidorcas australis) were adapted to the grassy environment of the PAP and these specialisations likely contributed to their extinction along with changing climates and intensified hunting from humans. When predicting herbivore viii biomass, biome was the most important factor influencing the relationship between herbivores and rainfall. In general, large herbivore biomass increased with rainfall across biomes, except for grassland. Finally, I showed the probability of occurrence of large herbivores was influenced by early humans, water availability and a landscape of fear on the PAP. Through this thesis I have successfully provided detailed accounts of the biomass and probability of occurrence of large herbivores on the PAP. Importantly, this information can be seamlessly integrated into the PaleoscapeABM. Finally, I highlight the importance of this knowledge in understanding early humans, the potential shortcomings of this study and resulting areas where research needs to be focused. , Thesis (PhD) -- Faculty of Science, School of Natural Resource Management, 2021
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- Date Issued: 2021-04
Presidential accountability for cabinet appointments in South Africa
- Authors: Phorego, Molefhi Solomon
- Date: 2021-04
- Subjects: Gqeberha (South Africa) , Eastern Cape (South Africa) , Executive power--South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/51212 , vital:43228
- Description: The President’s power to appoint cabinet members in South Africa constitutes an essential part of the country’s constitutional framework. It is a discretionary power exercised by the President in his capacity as Head of State bestowed on him by the Constitution, which underpins cabinet appointments.The underlying debates in relation to the President’s power to make cabinet appointments lie between justiciability and non-justiciability. In this respect, there are two schools of thought regarding the question whether the exercise of such a power may be the subject of a judicial inquiry, and if so, to what extent. This thesis provides insight into the nature and origin of the President’s power to appoint cabinet members. It also delves deeply into issues raised by the doctrine of separation of powers surrounding the exercise of this power. The core focus of the thesis is on the extent to which the President can be held accountable for making cabinet appointments. The main argument advanced is that because South Africa is a country founded on the principles of constitutional supremacy and the rule of law, every exercise of public power should be subject to the Constitution, including the President’s power to appoint cabinet members. The determination of whether public power is in line with the dictates of the Constitution calls for an independent judiciary, with the power to rule on any aspect of societal disputes. In pursuit of the above, the thesis analyses the constitutional provisions and case law relevant to the President’s powers as Head of State. The research highlights, amongst others, the President’s duty to give reasons for cabinet appointments. On this point it is submitted that the President does have the constitutional obligation to give reasons for cabinet appointments. Comparisons with other jurisdictions on cabinet appointment processes and oversight mechanisms regarding the exercise of that power form the backdrop against which recommendations are made in the thesis. Proposals are advanced for increased legislative oversight in cabinet appointments. Such oversight should focus on inter alia, the President’s duty to furnish reasons for cabinet appointments. The thesis also proposes a constitutional framework in terms of which Parliament plays a role in the selection of appointees to cabinet. The rationale behind this recommendation is the minimising of instances in which the judiciary is accused of overreaching on the powers of the political organs of government. The courts should, however, still retain the power to pronounce whether both the President and Parliament have fulfilled their relevant constitutional obligations in relation to the process of cabinet appointments. , Thesis (PhD) -- Faculty of Law, Public Law, 2021
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- Date Issued: 2021-04
Score driven volatility models based on skewed-t distributions
- Authors: Janse van Rensburg, Stéfan
- Date: 2021-04
- Subjects: Gqeberha (South Africa) , Eastern Cape (South Africa) , GARCH Model
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/52010 , vital:43425
- Description: Score driven (SD) conditional volatility models allow for rich volatility dynamics and realistic distributional assumptions. These models link the evolution of time-varying volatility to the shape of the predictive density, which often results in models that are robust against outliers. These models also allow for conditional skewness. The combination of skewness and robustness may improve in-sample fit, conditional volatility forecasts and tail-risk forecasts. Therefore, this study proposes novel SD conditional volatility models with Skewed-t distributed innovations. For some of these models, the formof skewness partially negates robustness against outliers. This result demonstrates that the formof skewness requires careful consideration in the specification of SD conditional volatility models. The study also expands upon earlier observations that the assumption of negative conditional skewness may induce a form of volatility asymmetry in SD conditional volatility models that is incompatible with the leverage effect typically observed in equity markets. A simulation experiment shows that neglected leverage, therefore, biases maximum likelihood estimates. Additionally, the study considers SD conditional volatility models that account for leverage effects and have Skewed-t distributed innovations. An empirical application to the daily Johannesburg Stock Exchange (JSE) / Financial Times Stock Exchange (FTSE) All Share Index returns demonstrates the utility of SD conditional volatility models with Skewed-t distributed innovations. Extensions of these models that account for leverage prove competitive with more traditional conditional volatility models in terms of in-sample fit and tail-risk forecasts. These results suggest that the models considered in this study are useful within the context of financial risk management. , Thesis (PhD) -- Faculty of Science, School of Computer Science, Mathematics, Physics and Statistics, 2021
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- Date Issued: 2021-04
South Africa’s auto industry trade elasticity to economic performance in BRICS countries
- Authors: Siswana, Babalwa
- Date: 2021-04
- Subjects: Gqeberha (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/52980 , vital:44901
- Description: South Africa’s automotive industry is a vital element in the country’s economy. This sector has been a strategically important sector in South Africa, and it is imperative to ensure not only the sustainability of the automotive sector in the country, but also the continued growth of the industry. This study addressed the determinants of South Africa’s automotive exports to BRICS countries. The main aim of the study is to examine South Africa’s automotive industry trade elasticity to economic performance in BRICS countries. An econometric assessment was done using different estimation techniques, namely Dynamic Panel Data General Method of Moments (GMM) on annual data from 2000 to 2016, quantile regression for the same period, and ANOVA analysis. This study used eight endogenous variables in explaining determinants of South African automotive export to BRICS countries. The results from the GMM technique suggested that only four variables out of eight variables were statistically significant, namely, automotive exports lagged once, corporate tax, research and development (R&D), and real exchange rates. Gross Domestic Product (GDP), Foreign Direct Investment (FDI), trade openness, and R&D all reduced automotive exports in South Africa. Quantile regression provided difference compared to the GMM dynamic panel data analysis. In the panel data analysis, corporate tax was positive, while in the quantile regression only Brazil’s corporate tax had a positive effect on South African automotive exports. FDI results in panel data GMM results were the same as quantile, while other variables results were not consistence with the dynamic panel data GMM results. The ANOVA results suggested that significant differences between BRICS countries impact on South Africa’s automotive exports. The findings indicate that South African automotive exports to BRICS have been proven to be elastic in four variables., namely, automotive exports lagged once, corporate tax, research and development (R&D), and real exchange rates. The South African automotive industry implemented policies such as the Motor Industry Development Programme (MIDP) and the Automotive Production and Development Programme (APDP); however, these policies failed to realise the targets set by the v industry. On the policies regarding automotive exports in South Africa, it is equally important to pay attention to corporate tax in South Africa as well as in other BRICS countries. BRICS economies lack policy synchronisation, hence the adverse impact on South African automotive exports. South Africa’s BRICS counterparts are knowledge-driven economies. Developing a strong human base is required in the sector. In addition, there is a need for BRICS countries to have a free trade agreement (FTA) to enhance trade amongst member states. Having free trade could help to make BRICS economic integration more meaningful to BRICS countries and the region. , Thesis (PhD) -- Faculty of Business and Economic Sciences, School of Economics, Development and Tourism, 2021
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- Date Issued: 2021-04
Spatial fisheries management options for inclusion in marine spatial planning in South Africa
- Authors: Reed, Jodie Romay
- Date: 2021-04
- Subjects: Gqeberha (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/52068 , vital:43451
- Description: Integration of sectoral based management into a coherent and coordinated spatial management framework is one of the central challenges of marine spatial planning ȋMSPȌǤ MSP initiatives aim to provide operational frameworks to promote sustainable use of the economic potential of the ocean while maintaining the value of marine biodiversity and the integrity of marine ecosystems to provide servicesǤ The ecosystem services associated with fisheries in terms of food and job provision are some of the most well recognised and highly valued in the marine realm and maintaining these benefits depends on a holistic understanding of the ecosystemǡ human uses and the management thereofǡ including areaǦbased managementǤ In ͲͰͱǡ South Africa was the first African country to enact MSP legislationǤ The development of MSP was advanced through a Presidential ocean economy initiative ȋOperation Phakisaǣ Oceans EconomyȌ that aimed to fast track marine transport and manufacturingǡ aquacultureǡ and the development of oil and gasǡ small harbourǡ and coastal and marine tourismǤ A dedicated ocean governance component was included to develop an overarchingǡ integrated ocean governance frameworkǤ The absence of fisheries in the plans and initiatives was conspicuousǤ The implementation of MSPǡ howeverǡ provides an opportunity to safeguard the ecosystem services provided by fisheries but only if the interests of fisheries can be adequately reflected in spatial plans and analysesǤ Furthermoreǡ the implementation of MSP may provide new opportunities for innovation in spatial approaches to local fisheries management that could address numerous spatial conflicts that have been reportedǤ Integration of spatial fisheries management approaches into MSP can also support the implementation of ecosystemǦbased management ȋEBMȌǡ by including mechanisms such as habitat protectionǡ effective management of areas important for vulnerable life history stagesǡ and bycatch managementǤ This study aimed to identifyǡ assess and further develop spatial management options for fisheries to facilitate the integration of fisheries management and MSPǤ This was achieved by firstlyǡ identifying existing spatial management instruments and assessing the way in which these instruments may be implemented to support spatial fisheries managementǤ Secondlyǡ the application of two contrasting spatial management optionsǡ applied to two pelagic fisheriesǡ was examined to assess their effectiveness at achieving fisheries management objectives with a focus on bycatch reductionǡ while minimising the costs to the fisheries. , Thesis (PhD) -- Faculty of Science, Ocean Sciences, 2021
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- Date Issued: 2021-04
The Effect of Using English as A Language of Learning and Teaching on Learner Academic Performance in Senior Phase of Mthatha, Eastern Cape Province
- Authors: Seabela, Marcia Motlatso
- Date: 2021-04
- Subjects: teaching strategies
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/11260/6782 , vital:49059
- Description: The study sought to investigate the effect of using English as a language of learning and teaching on learner academic performance in the senior phase of Mthatha District, Eastern Cape Province. This study employed a mixed-method approach. The researcher used both qualitative and quantitative methods to collect data. The study was conducted in 3 semi-rural senior secondary schools that were conveniently selected. The quantitative part employed Likert-type scale questionnaires that were administered to 10 Mathematics (Math), 10 Natural Sciences (NS) and 10 Social Sciences (SS) teachers making a total of 30 teachers and a total of 30 learners from grades 8 and 9. For the qualitative part, nine (9) teachers and eighteen (18) learners from the selected schools were interviewed. The 18 teachers in three schools were observed as they taught Grade 8 and 9 learners in their respective classes. Qualitative data were, thus, gathered through interviews and observations. Quantitative data was collected using Likert-type scale questionnaires and was analysed using descriptive statistics and Microsoft Excel. The voice recorded qualitative data from the participant’s responses were transcribed and analysed manually through coding, forming categories and themes that were used for data presentation. These are some of the findings: The majority of learners do not understand English, therefore, it was difficult for them to understand the teaching and learning of the selected subjects in Senior Phase (SP) using English as the language of learning and teaching (LoLT); Although the majority of learners reported that they usually use English as a LoLT and their home language when learning the selected subjects, they still struggled to ask and answer questions in English in a classroom and during examinations; Learners who experience difficulties in learning the selected subjects through the use of English as a LoLT in SP, were taught in their home language (isiXhosa) by their teachers; English and isiXhosa, in the form of code-switching, were used when teaching the selected subjects; Inadequate teacher training and preparation made it more difficult for the learners to perform well in the selected subjects. The study recommends that: The Department of Education should conduct enough workshops to help HOD’s and teachers who teach the selected subjects to keep abreast of new developments in these subjects. These should be integrated with appropriate teaching strategies and learning and teaching support materials. Keywords: English as the language of learning and teaching, teaching strategies, learning, teaching support materials. , Thesis (D.Ed) -- Faculty of Education Sciences, 2021
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- Date Issued: 2021-04
The implementation of tourism curriculum in secondary schools in Fort Beaufort Education District, Eastern Cape Province: implications for sustainable tourism
- Authors: Mbilini-Kuze, Bukiwe Nomonde Constance
- Date: 2021-04
- Subjects: Education, Secondary -- Curricula , Curriculum planning
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/24728 , vital:63536
- Description: This study examined the implementation of Tourism curriculum in Secondary Schools in Fort Beaufort Education District in the Eastern Cape. The study arose from a concern that despite the Government of the Eastern Cape organizing workshops to facilitate the implementation of Tourism curriculum for secondary school teachers, research has shown that teachers have not improved their classroom practice. It discussed the concept of Tourism curriculum implementation and highlighted problems militating against curriculum implementation at secondary school level. The researcher adopted the mixed method methodology which is embedded in the post-positivist research paradigm. The post-positivist research paradigm explains the way things are and views objectivity as an ideal that can never be achieved, however research should be conducted with greater awareness of subjectivity. By combining qualitative and quantitative methodologies, it assisted the researcher to strike a balance and avoid being subjective on issues of teacher capacity, teaching strategies and assessment, availability and use of resources and support and monitoring. The research methods used in this study include questionnaires, interviews, document analysis and observations. The findings of the study showed that there are limitations in the implementation of Tourism curriculum because of lack of capacity of School management Teams and teachers who are implementing NCS Tourism. Although the teaching strategies and assessment are stipulated in the curriculum document teachers are not using appropriate methods and assessment. Moreover, there are crucial resources and facilities provided by SMTs and the Department of Education to implement Tourism curriculum, inadequate compared to those provided for other subjects. Moreover there are limitations in terms of support (including training) and monitoring systems which are in place to enable the implementation of NCS Tourism. Possible areas for future research were highlighted and recommendations were made, for example the researcher recommends teachers to be trained adequately in order to effectively implement the Tourism curriculum. Teachers should be encouraged to use new learner-centred teaching strategies and resources should be provided in all secondary schools through the combined effort of the government, Fort Beaufort Education district and the School Management Teams (SMTs). Support and monitoring systems should be in place for proper implementation of Tourism curriculum. Tourism industries should contribute through provision of instructional materials and teachers as implementers of the curriculum should be involved in decision-making and curriculum planning. The government should employ enough teachers qualified to teach Tourism. On the other hand subject advisors should be adequately trained to enable them to provide relevant support to teachers in Fort Beaufort secondary schools. All stakeholders should be involved in fostering skills and capacities at local level to develop sustainable Tourism and local development in an integrated way. The study identified a possible an alternative model for the implementation of Tourism curriculum. , Thesis (PhD) -- Faculty of Education, 2012
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- Date Issued: 2021-04