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 behaviour of South Africa’s economy towards inflows of foreign direct investment (FDI) from BRICs economies
- Authors: Dingela, Siyasanga
- Date: 2021-04
- Subjects: Investments, Foreign -- South Africa , Investments, Foreign -- Developing countries , South Africa -- Economic conditions , BRIC countries -- Foreign economic relations
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/51141 , vital:43212
- Description: This study investigated a behaviour of South Africa’s economy towards inflows of foreign direct investment (FDI) from Brazil, Russia, India and China (BRICs) economies, during the period 1997 to 2016. The BRICs bloc was coined in 2001 by then chairperson of Goldman Sachs Asset Management, Jim O’Neil. According to Goldman Sach (2001), the BRICs group was collectively expected to overtake the major economic powers over the span of a few decades. Their growth is expected to shape a new economic order and replace the currently dominant advanced economies. South Africa joined the BRICs bloc in 2010 as the jeweler of the world and as a gateway to Africa. It joined the BRICs group at the time when economic growth was at a sluggish rate, and the savings and investment were at the lowest rate. The country had a high unemployment rate, high levels of poverty and income inequality. On the other hand, the BRICs economies had limited intra-BRICs flows amongst themselves. It is against this background that this study investigated the long run impact of BRICs FDI inflows on South Africa’s economic growth, and the causality relationship between South Africa’s economic growth and BRICs FDI inflows. This study contributes to the body of knowledge of economics in South Africa and the literature on foreign direct investment and economic growth in South Africa. The study employed two cointegration methods to investigate the behaviour of South Africa’s economy towards inflows of foreign direct investment from BRICs economies. These are fully modified ordinary least squares (FMOLS) and dynamic ordinary least squares (DOLS). For granger causality, the study employed Stacked and Dumistrescu Hurlin tests. All the models used time series annual data from 1997 to 2016. The Unit root test results confirmed that the variables were stationary at first difference using panel Im, Pesaran, Shin (IPS) and Levin, Lin, Chu (LLC). The research employs four regressions, first, Economic growth and foreign direct investment (i.e. private sector, banking sector and both sectors), human capital, physical capital, household consumption, government expenditure, exports, and arable land; Second, Employment and foreign direct investment, human capital, physical capital, household consumption, government expenditure, exports, and arable land; third, Economic complexity and foreign direct investment, human capital, physical capital, household consumption, government expenditure, exports, and arable land; finally, Unemployment and foreign direct investment, human capital, physical capital, household consumption, government expenditure, exports, and arable land. The cointegration results for private FDI and economic growth, employment, economic complexity, and unemployment. The results show only economic complexity has significant effect on foreign direct investment and other variables show insignificant results. However, this effect is smaller compared to other growth determinants which are included in the regressions. The cointegration results for bank FDI. These results show more similarities with private FDI results and few differences. However, this effect is smaller compared to other growth determinants included in the regressions. These growth determinants, however, show a positive effect of human capital and household consumption on economic growth which is expected. Other interesting results are exports being positively related with economic growth and unemployment but negative with employment and insignificant with economic complexity. Another one is government spending negatively influence economic growth, employment and positively influence unemployment. But insignificant for economic complexity. Total FDI results and other variables. These results are also similar to private and bank FDI results discussed above. Economic complexity shows significant effect with foreign direct investment, yet other variables are insignificant. . Further results show human capital positively related with economic growth, which is expected. However, physical capital and household consumption negatively affects growth. Another one exports show positive influence on economic growth but negatively related with employment. Yet, insignificant with economic complexity and unemployment. Other results government spending shows negative influence with employment but insignificant with economic growth, economic complexity and unemployment. The results for nonlinearity between the variables under review. The results that employment and economic complexity are nonlinear with foreign direct investment and no nonlinearity between unemployment, economic growth and foreign direct investment. For employment, low levels of foreign direct investment (LFDI_private) adversely affects employment but at higher levels (FDI_private_SQ) is insignificant. For economic complexity, low levels of foreign direct investment are insignificant for economic complexity but at higher levels there is a positive effect of squared foreign direct investment on economic complexity. Further results show that economic growth and employment are nonlinear with human capital, physical capital, household consumption and exports. Physical capital and household consumption adversely affect economic growth, yet positively affects employment. Human capital positively affects economic growth, employment, and unemployment. Exports positively affect economic growth, but negatively affect employment. Further results show nonlinearity between employment and government expenditure. Government expenditure adversely affects employment. Also, economic growth and unemployment show nonlinearity with arable land. Arable land adversely affects economic growth but positively affects unemployment. Nonlinear results for economic growth and economic complexity with foreign direct investment but no nonlinearity in other remaining variables. For economic growth, low levels of foreign direct investment there is a positive effect of foreign direct investment on economic growth, however, at higher levels foreign direct investment are insignificant. For economic complexity, low levels of foreign direct investment are insignificant, yet, higher levels of foreign direct investment there is a positive influence of foreign direct investment on economic complexity. Further results show economic growth and employment that are nonlinear with human capital, physical capital, and household consumption. Human capital positively affects both economic growth and employment. Physical capital and household consumption are adversely affecting economic growth, yet positively affects employment. Further results show nonlinearity between economic growth and government expenditure. Government expenditure adversely affects employment. More results, employment, and unemployment show nonlinearity results with exports. Exports adversely affect employment but positively affects unemployment. Results show economic growth and unemployment that are nonlinear with arable land. Arable land adversely affects economic growth, but positively affect unemployment. Nonlinear results for economic complexity only and other variables show no nonlinearity in the regressions. For economic complexity, low levels of foreign direct investment are insignificant, but at higher levels of foreign direct investment there is positive effect of foreign direct investment on economic complexity. More results show economic growth and employment that are nonlinear with human capital, physical capital, household consumption and exports. Human capital and exports positively affect economic growth, employment, and unemployment. Whereas, physical capital and household consumption adversely affects economic growth and unemployment, yet positively affects employment. Further results show nonlinearity between employment and government expenditure. Government spending adversely affects employment. Further results show nonlinearity between economic growth and unemployment with arable land. Arable land positively affects unemployment, yet adversely affects economic growth. The following section discusses granger causality results. This study also employed granger causality tests. The causality results between economic growth, employment, economic complexity, unemployment, and private foreign direct investment. The causality results show that there is granger causality between economic growth and economic complexity with private foreign direct investment. Whereas, between bank foreign direct investment and other variables there is no granger causality. However, between total foreign direct investment and economic growth and employment there is granger causality. There are a number of policy recommendations that can be drawn from the study. The study results in overall revealed that BRICs (private and bank) FDI inflows had a positive impact on South Africa’s economic growth between 1997 and 2016. The study results suggest that the policy makers should focus the attention on lobbying foreign direct investment from BRICs economies, since this study shows positive impact and relationship between South Africa’s economic growth and BRICs FDI inflows. The BRICs economies should focus on enhancing investment partnership, preventing protectionism, and promoting intra-BRICS flows. In addition, South Africa should eliminate barriers affecting business with BRICs countries. Policy makers should promote the building of new companies (for example Greenfield Investment) so that the economy of South Africa could grow and create employment. , Thesis (MA) -- Faculty of Business and Economic Sciences, Economics, 2021
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- Date Issued: 2021-04
A best practice guideline for the management of the quality of objective structured clinical examinations at a multi-campus public college of nursing
- Authors: Nyangeni, Thandolwakhe
- Date: 2021-04
- Subjects: Nursing assessment-- Management , Clinical Competence -- Management
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/51466 , vital:43281
- Description: An Objective Structured Clinical Examination (OSCE) is a robust method of clinical assessment which, when properly planned and executed, results in a high quality and credible student assessment. However, concerns regarding its uniformity, fairness, objectivity and accuracy have been raised. Concerns regarding the management of the quality of OSCEs at a public College of Nursing in the Eastern Cape were raised by the College’s stakeholders. No best practice guideline had been developed regarding the management of the quality of OSCEs for this College. The aim of this study was therefore to develop a best practice guideline for the management of the quality of OSCEs at a public College of Nursing. The Transformative Pedagogy Theory proposed by Khedkar and Nair was used as a philosophical underpinning for this study. The Joanna Briggs Institute (JBI) model for evidence-based healthcare was used as a theoretical basis for this study. In Phase One, a qualitative, explorative, descriptive and contextual design was used to explore and describe the experiences of nurse educators regarding the management of the quality of OSCEs at a multi-campus public College of Nursing. Semi-structured individual interviews were used to collect data from fourteen (n=14) nurse educators. Thereafter, a qualitative document analysis of fifteen (n=15) external moderators’ reports was conducted to explore the information external moderators shared regarding the management of the quality of OSCEs at a multi-campus public College of Nursing. A document analysis checklist designed by the researcher was used to extract the data from external moderators’ reports. Tesch’s method of data analysis was utilised to analyse the data from the interviews while the data analysis process proposed by Dalglish, Khalid and McMahon was used to analyse the data from the external moderator’s reports. In Phase Two, an integrative literature review was conducted to search, select, extract, appraise and synthesise best practices regarding the management of the quality of OSCEs in health sciences education. The adapted integrative literature review steps, as proposed by de Souza, da Silva and de Carvalho, were utilised to guide this phase. Data of a total of thirteen (n=13) articles were extracted and synthesised. In Phase Three, the findings of Phase One and Phase Two were synthesised, as a basis for informing the development of a best practice guideline for the management of the quality of OSCEs. The National Institute for Health and Care (NICE) and the Appraisal of Guidelines for Research and Evaluation II (AGREE II) frameworks were used as a basis for developing the best practice guideline for the management of the quality of OSCEs at a multi-campus public College of Nursing. The draft best practice guideline was reviewed by eight (n=8) expert reviewers who were experienced in conducting OSCE’s and best practice guideline development. Lincoln and Guba’s principles—namely credibility, transferability, dependability and confirmability were applied to ensure the trustworthiness of the interview data. Wesley’s criteria- namely triangulation, thick description and audit trail were used to ensure the trustworthiness of the document analysis. The principles as stipulated in the Belmont Report were applied in order to ensure the ethical soundness of this study. Findings of the interviews and the document analysis in Phase One revealed that, while there are measures currently in place to facilitate quality in the management of OSCEs in this College of Nursing, there are gaps such as uncertainty in the assessment practices being used and resource constraints that hinder the overall quality of OSCEs. The participants indicated the need for the development of a best practice guideline for the management of the quality of OSCEs at this College. Findings from the integrative literature review in Phase Two revealed three themes, namely: apply quality measures in the preparation and planning phase of OSCEs; apply quality measures in the implementation phase of OSCEs; and apply quality measures in the evaluation phase of OSCEs. For Phase Three, the developed best practice guideline included three recommendations regarding the quality measures that should be applied in each of the three phases of OSCEs. It is recommended for the developed best practice guideline to be further refined, piloted and implemented to be used by nurse educators and other relevant stakeholders Once implemented, the guideline is expected to enhance the management of the quality of OSCEs at the multi-campus College of Nursing and, ultimately, nursing and patient outcomes through quality nursing education and assessment. , Thesis (PhD) -- Faculty of Health Sciences, 2021
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- Date Issued: 2021-04
A framework for public infrastructure financing in Zimbabwe
- Authors: Kapesa, Tonderai
- Date: 2021-04
- Subjects: Finance, Public -- Accounting -- Standards , Accounting -- Standards , Finance -- Zimbabwe , Infrastructure (Economics) -- Zimbabwe -- Finance
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/51688 , vital:43363
- Description: The Government of Zimbabwe is operating using the mantra: ‘Zimbabwe is open for business’. The notion of opening for business requires robust supporting economic infrastructure for enhanced productivity, in the form of reliable supply of electricity, accessible road/railway transport networks and availability of contemporary Information Communication Technology (ICT) infrastructure. The aim of the study was to develop a framework for making financing decisions for public infrastructure in Zimbabwe. The objectives of the study are to: determine the main sources of public infrastructure financing in Zimbabwe; establish innovative finance’s capacity to close the public infrastructure financing gap in Zimbabwe; assess the role played by public-sector accounting in attracting appropriate and efficient mechanisms to finance public infrastructure in Zimbabwe; and ultimately to develop and recommend a framework for selecting suitable and efficient mechanisms to finance public infrastructure in Zimbabwe. According to literature reviewed, public infrastructure is broadly financed by public sector entities using their own resources (internally financed) or through private sector investments and innovative financing instruments (externally financed). When infrastructure is internally financed, the study is theoretically guided by the Public Goods Theory and the Theory of Public Finance and Public Policy. When externally financed, the Risk Return and Pecking Order theories are important. There are many instruments used to finance public infrastructure and one project may be financed using one or more instruments. Therefore, considerations are given to the need for a framework that helps improve the efficiency of the financing decision. The study was designed as a multiple case study that focused on four sectors of economic infrastructure, that is, transport, energy (electricity), ICT as well as water and sanitation. The research used synchronous mixed methods to achieve the objectives of the study. Qualitative research methods addressed the following objectives: a) to determine the main sources of public infrastructure financing in Zimbabwe; b) to establish innovative finance’s capacity to close the public infrastructure financing gap in Zimbabwe; and c) to assess the role played by public-sector accounting in attracting appropriate and efficient mechanisms to finance public infrastructure in Zimbabwe. Whilst to develop and recommend a framework for selecting suitable and efficient mechanisms to finance public infrastructure in Zimbabwe the study combined qualitative and quantitative research methods. Qualitative data was collected through interviews conducted with officials and staff from government ministries, government departments, as well as parastatal enterprises dealing with the four infrastructure types. The same respondents were asked to complete a survey questionnaire used to address part of the objective that developed a framework for public infrastructure financing. Interview data were triangulated using secondary data extracted from reports and financial statements. Some of the secondary data was collected from the World Bank’s development indicators online repository. Qualitative data analysis was done using RQDA, an open-source computer-aided data analysis software. Findings from the study revealed that the main sources of finance for public infrastructure in Zimbabwe are the government through budget appropriations, and concessionary loans from the China Export-Import Bank. There was also finance obtained from multilateral financial institutions such as the Development Bank of Southern Africa and the African Export-Import Bank. The study revealed that there is currently very limited use of innovative financing instruments such as PPPs in financing public infrastructure in Zimbabwe, despite the country having legislation to support such financing arrangements. The innovations in financing observed in the study entail the use of conventional financing mechanisms in unconventional ways. However, there is scope for improving the financing of public infrastructure using innovative financing mechanisms and significantly mitigate the financing gap. Public sector accountants in Zimbabwe are mainly active in financial reporting, although the financial statements for most ministries, government departments and parastatal enterprises had qualified audit opinions from the Auditor General’s office. Public sector accountants are not active in financial management and cost and management accounting responsibilities. As a result, public sector accountants are not adding value to public money through offering advisory services in the efficient investment of public money, as well as financing public infrastructure assets using the most efficient financing mechanism. There is no uniformly applied framework when making financing decisions for public infrastructure in Zimbabwe. Therefore, a framework was developed and is recommended for use by this study. The developed framework entails eight steps that are interrelated and interconnected. Use of the proposed framework requires availability of data about infrastructure projects that have been done in the past. The study recommends that Zimbabwe should ensure a robust framework for protecting private sector investments, which can be achieved by ensuring policy consistency; creating and implementing a legal framework that protects private capital; and having economically viable infrastructure sectors, that are liberalised to allow private sector participation. The Government of Zimbabwe must take deliberate actions that ensure variety of financing options at the disposal of the public sector to lower costs of financing public infrastructure. It is also important to fully operationalise the legislation and policies designed to facilitate the participation of the private sector in financing public sector projects. Such operationalisation entails a decentralisation of the regulations and policies to the provincial and municipal levels. , Thesis (PhD) -- Faculty of Business and Economic Sciences, Accounting, 2021
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- Date Issued: 2021-04
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 problematisation of Afrikaner identity subject positions as found in the coverage of contemporary Afrikaans music in HUISGENOOT magazine discourse
- Authors: Hughes, Lestie
- Date: 2021-04
- Subjects: Afrikaners -- South Africa -- Music -- History and criticism , Multimedia (Art)
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/52558 , vital:43686
- Description: Through the lens of Foucauldian genealogy, this thesis problematises the subject positions towards Afrikaner identity reflected in contemporary Afrikaans songs covered by Huisgenoot magazine. Such a genealogical exploration thematises the games of truth underpinning the formation of Huisgenoot, highlights its role in solidifying white Afrikaner Nationalist discourse of apartheid, observes its more populist, profit-oriented approach from the 1970s onwards and considers the residual echoing of its former discursive orientation. The song analysis of selected Afrikaans songs/music videos covered in Huisgenoot is guided by the semiotics of Nicholas Cook, such that it frames the analytical question of how such music is driven by conformance, contest and complementation between multi-media elements in ways that make meaning possible. Accordingly, this methodology resonates with the non-essentialising focus of Foucauldian problematisation, premised on critical resistance that makes new responses simultaneously possible. The self-reflexive autoethnographical approach employed, entailing the author’s dialogical engagement with her own ‘Afrikaner self’, similarly facilitates the dynamic interplay between multiplicities. Correlatively, on the one hand, more ‘closed’ and more ‘open’ Afrikaner identity positions reflected within the songs are analysed, as well as seemingly ‘reconciliatory’ / collaborative’ musical manifestations which ultimately revert back to more ‘closed’ identity constructs. But on the other hand, observation of adherence to a ‘white-black’ dichotomy within songs that manifest more ‘closed’ identity positions also leads to consideration of the parallels between the goals of white Afrikaner Nationalism and the current Decolonisation narrative, which is informed by Black Consciousness thought and generated by the ‘Colonisation of a Special Kind’ ANC policy. Both such Decolonisation rhetoric and the countering rhetoric of the Neo-Afrikaner Protest Movement (NAP) are thus identified as metanarratives, underpinned by a ‘white-black’ dichotomy. In this regard, while Huisgenoot’s predisposition towards songs manifesting more ‘closed’ Afrikaner identity positions is considered in terms of its aforementioned profit-oriented endeavour to appeal to its ostensible primary readership, an encouraging increase in coverage of coloured artists is both noted and occasionally seen to overlap with its coverage of songs manifesting more ‘open’ Afrikaner identity positions. Among the latter one may – again in Foucauldian terms – differentiate between songs focussed on an engagement in cross-cultural relations of power, and songs intent on shattering states of domination of power blocks, often through shocking juxtaposition of disparate elements. These more violently dismantling endeavours, it is argued, comprise examples of Foucauldian transversal struggles, although their coverage in Huisgenoot is also attributed to their shock value and/or record sales, rather than their transformational potential. Furthermore, such Huisgenoot coverage is also seen to place more transformationally oriented artists at risk of media ‘domestication’, with its concomitant inhibiting of creativity. Finally, the researcher’s commitment to creative problematisation of her own Afrikaner identity, coupled with acknowledgement of her inescapable textual entrapment, culminates in her acceptance of the continual flux characterising dialogical power relations, before she – in accordance with the Foucauldian methodology employed – presents all ‘conclusions’ in a non-dictatorial spirit of ‘truth creation’, desirous of continual self/other dialogue. , Thesis (PhD) -- Faculty of Humanities, 2021
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- Date Issued: 2021-04
A sociological investigation of child labour in the fishing communities of Kalangala, Uganda
- Authors: Majanja, Zaaly’embikke Irene Margaret
- Date: 2021-04
- Subjects: Child labor -- Uganda -- Sociological aspects
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/53428 , vital:45153
- Description: The researcher conducted a sociological investigation into the persistence of child labour in the fishing communities of Uganda, specifically in the Ssese Islands, Kalangala District, on the Kisaba and Nakibanga landing sites situate in Bukasa. The study aimed at investigating the sociological aspects of persistent child labour practices in the fishing communities. The study employed a qualitative research method with a descriptive case study design, utilising an interpretive paradigm. The case study design facilitated the researcher’s investigation into child labour practices in their natural settings. The study employed mainly in-depth interviews, focus group discussions and observations for data collection. Data analysis was performed utilising the ATLAS.ti computer software package to identify the sociological factors involved with employing child labour. The Various themes emerged from the data analysis. The study established that despite the Ugandan Government domesticating all the UN/ILO Conventions on Rights of a Child and Worst Forms of Child Labour, the OAU Charter on Child Rights and Welfare and also instituting legal frameworks at national level, the practice of using child labour persists. The findings disclosed that economic, sociological and structural factors appear to perpetuate child labour in the fishing communities. Economic factors such as poverty, unemployment or underemployment, then sociological aspects such as men abandoning their helpless families on landing sites as they follow the fish according to seasons. Furthermore, the community attitudes such as low value for education, child labour being a normal trend and part of apprenticeship for the children. Again, there are structural issues such as the inadequate implementation and the weak enforcement of the legal frameworks, including insufficient infrastructures such as schooling facilities. These factors appear to perpetuate child labour in the fishing communities. The study concluded that there is an urgent need to address the issues associated with the persistence of child labour in the fishing communities. The study recommends employing a holistic multipronged approach through bottom-up participatory planning and integrating stakeholders at various levels. This could enhance efforts and share ideas and resources that can result in effective operations in order to eliminate child labour in the fishing communities. , Thesis (DPhil) -- Faculty of Humanities, 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, André John
- Date: 2021-04
- Subjects: Problem solving -- Study and teaching , Divergent thinking -- Study and teaching , Sustainable development -- Study and teaching , Environmental education
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/50907 , vital:43148
- 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
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
Best practice psychosocial–cultural care guideline for primary caregivers of couples in the Talensi and Nabdam districts of Ghana experiencing infertility
- Authors: Kuug, Anthony Kolsabilik
- Date: 2021-04
- Subjects: Caregivers -- Infertility -- Ghana , Couples -- Infertility -- Ghana
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/51264 , vital:43258
- Description: Infertility remains a major clinical and social problem, affecting approximately one in every ten couples. The implications of infertility range from physical abuse to denial of family property, divorce, psychological problems, such as withdrawal, anxiety and depression to social isolation, scorn, rejection and stigmatisation. The health of infertile couples needs holistic attention because, while their medical and surgical needs are addressed to correct physical and physiological barriers of infertility, their psychological and emotive needs, which constitute the psychosocial aspects of infertility, need to be addressed as well. The current study explored and described the experiences of couples with infertility and primary caregivers who rendered care to couples. The study aimed to develop a best practice psychosocial-cultural care guideline for primary caregivers to enhance the management of couples experiencing infertility in Talensi and Nabdam districts of the Upper East Region in Ghana. The study followed a qualitative design while making use of explorative, descriptive contextual and interpretive ethnographic approaches. The research populations comprised couples experiencing infertility and the primary caregivers who cared for them, consisting of public health nurses and midwives. The research study comprised three phases. In Phase 1, semi-structured interviews, narrative sketching and storytelling were used to collect data on experiences of couples with infertility while semi-structured interviews were used to explore and describe the experiences of primary caregivers who cared for them. The interviews were transcribed and analysed using Tesch’s eight steps of data analysis to make sense of the data collected. The researcher ensured the validity of the study by conforming to the Lincoln and Guba’s approach to trustworthiness by using an independent coder to validate the researcher’s coding. In Phase 2, an integrative literature review was conducted to identify previous guidelines and systematic reviews regarding psychosocial–cultural care of infertility. Relevant guidelines and reviews were selected and critically appraised. Data were extracted and synthesised for the development of a best practice guideline for psychosocial–cultural care of couples experiencing infertility. An independent appraiser critically appraised relevant guidelines to ensure trustworthiness. In phase 3, the findings of Phases 1 and 2 were integrated to formulate a draft best practice guideline for psychosocial–cultural care of couples experiencing infertility. The guideline was reviewed by a six-member expert panel and modified based on their recommendations, suggestions and comments leading to the finalisation of the best practice psychosocial–cultural care guideline for primary caregivers of couples experiencing infertility in the Talensi and Nabdam districts in Ghana. , Thesis (PhD) -- Faculty of Health Sciences, 2021
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- Date Issued: 2021-04
Co-generating a people-centred approach to addressing student hunger at a South African university
- Authors: Mansvelt, Natalie
- Date: 2021-04
- Subjects: Food security -- South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/51309 , vital:43262
- Description: While considerable progress has been made regarding access to higher education in South Africa for previously excluded and disadvantaged students, great challenges are experienced in terms of student well-being. One of the key factors contributing to students’ ability to complete their studies successfully is food-related challenges. Various programmes have been introduced at institutions of higher education to assist and support students who lack funds for food. However, these programmes are characteristic of the welfarist model, as it is often based on needs, short-term by nature, and dependent on external resources. Furthermore, it reduces students to the role of passive beneficiaries. This research answers the question of how student hunger can be addressed through co-generating a people-centred approach at one higher education institution in South Africa. The study was underpinned by Sen’s capabilities approach to enable a theoretical understanding of the issue of student hunger. Additionally, Korten’s people-centred development provided the value base of the study to place students at the centre of the problem-solving process. An approach to student hunger that would be participative, student-centred, and enhancing nutritional capabilities was invited. Situated within the critical paradigm, I employed the participatory action research design to facilitate a process whereby students critically questioned the issue of hunger and took action to address the issue. Eight students from various study fields volunteered to co-research the issue of student hunger. Over the period of one year, we generated data using different methods (including photovoice, community self-survey, workshops, purposeful group discussions, focus group discussions, and my reflective notes). We applied cyclical processes to plan, implement, and reflect on actions intended to address student hunger. Through a combination of collaborative and individual processes of data analysis, we responded to four subquestions through four phases, which culminated in the co-construction of a people-centred approach to student hunger. Students’ conceptualisations of student hunger revealed two types: hunger of the stomach and hunger of the mind. The cyclical relationship between the two types infers that nutritional well-being is not achieved adequately when students have the means to acquire food. Choices regarding the utilisation of the available means also need consideration. The findings revealed that students apply the conscientisation framework in the ways that they plan to address student hunger. Applying value-driven processes, actions entailed physical dialogues with groups of people. The approach developed in this study offers strategies for the stakeholders who attend to student hunger, to collaborate and make contributions towards comprehensively resolving the complex issue. It primarily could be useful to institutions of higher education as the suggested coordinators of a collaborative structure. A second part of the developed approach puts forward a strategy to address the financial capabilities of students. The study contributes a consideration to constraints that stem from students’ mindsets and adoption of a prevailing culture that maintains student hunger. This demonstrates that resolutions to addressing student hunger might be more effective and sustainable if the context, views and participation of people experiencing the hunger are considered. , Thesis (PhD) -- Faculty of Health Sciences, 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
Enriching the physical education pedagogical content knowledge of foundation phase teachers
- Authors: Kahts-Kramer, Samantha Andrea
- Date: 2021-04
- Subjects: Physical education and training , Early childhood education -- Curricula
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/51242 , vital:43236
- Description: Physical Education (PE) is vital for the holistic development of Foundation Phase learners. Foundation Phase teachers working in low resource contexts, however, being generalists rather than specialists, struggle to teach PE effectively, even when supplied with programmes by external experts. I was interested in finding out why, and what could be done to help them integrate Fundamental Movement Skills (FMS) into their teaching, to benefit their learners. I proceeded from the hypothesis that teachers should play an active part in their own development, otherwise any Continual Professional Teacher Development (CPTD) would not bring about the change desired. I argued that if CPTD training and support is embedded within their context and based on teaching philosophies that foster teacher transformation, empowerment, and advocacy, then teachers might be more likely to commit to teaching PE. My aim in this study was thus to develop a collaborative process of CPTD with Foundation Phase teachers in low resource schools to enrich their pedagogical content knowledge (PCK) of PE and FMS within their contexts of social disadvantage. I initially adopted a qualitative design, but during this study, I realised that a more participatory approach was needed. I therefore present my study in two phases In Phase One, I answered the question: What are Foundation Phase teachers’ experiences of implementing PE in low resource schools? I did so to inform the design of an appropriately suited CPTD model for Phase Two of this study. I used a qualitative research design situated within the interpretive paradigm. I purposively sampled 24 Foundation Phase teachers to partake in semi-structured interviews. Thematic analysis revealed three broad themes, namely, personal, and systemic barriers to PE, as well as positive responses to challenges. The overlap between themes was significant, highlighting the complexity of teachers’ experiences and perceptions of PE. Teachers’ positive responses emphasised that they possess the creativity and advocacy to overcome challenges posed and necessitated that I adopt a participatory design to work with teachers to develop a collaborative form of CPTD. Phase Two of this study was guided by the questions set by the participating teachers. Ten Foundation Phase teachers from two schools volunteered to be part of the study. In Cycle One they asked: What do we need to learn to be able to effectively implement PE? The findings of Cycle One led them to ask the following question in Cycle Two: How can we improve our confidence to teach PE within our school contexts? Participants did so through collaboratively creating PE lessons which they then implemented and evaluated. The findings of Phase Two highlighted how Foundation Phase teachers can be guided to empower themselves to overcome the barriers to teaching PE that they face in their low resource schools. Based on teachers’ CPTD experiences, I then addressed the third question of this study: What CPTD guidelines can be generated to enable Foundation Phase teachers to improve on and to implement their PCK of PE and FMS at low resource schools? Five CPTD guidelines aimed at collaborative and transformative PE-based CPTD focused on whole school transformation were identified. I provide a graphic depiction of the CPTD guidelines that explains how it can be operationalised. These CPTD guidelines and process model provide valuable knowledge to inform CPTD policy and practice of PE in the Foundation Phase in low resource schools. , Thesis (PhD) -- Faculty of Health Sciences, 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