Influence of laser surface treatment on residual stress distribution and dynamic properties in rotary friction welded ti-6al-4v components
- Authors: Tsikayi, Davies Shamiso
- Date: 2019
- Subjects: Lasers -- Industrial applications , Friction welding Pressure welding Metals -- Research
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/43823 , vital:37050
- Description: This manuscript details a study on laser surface treatment, a surface modification technique that is an easily flexible way of improving material surface properties of complex geometries. The research explored the potential of laser surface modification/treatment as a post welding surface processing technique for RFW Ti-6Al-4V ELI components by evaluating the microstructural effects, influence on fatigue life and the depth and magnitude of residual stresses induced. The outcome of this study reveals how post processing by laser surface modification affects crack initiation hence fatigue life and further explains mechanisms potentially contributing to enhanced joint properties. This study was accomplished by investigating the effect of laser surface treatment on surface properties of hourglass cylindrical rotary friction welded Ti-6Al-4V ELI specimens. Preliminary work was done in two stages. The first stage involved conducting laser surface treatment on 3 mm Ti-6Al-4V sheets. In this stage, an understanding of the process variables concerning the laser surface treatment process characteristics was established. Laser power and focus position were varied whilst scanning speed was kept constant. The observed macrographs were quantified in terms of laser penetration depth and width. A hardness and microstructural analysis was also conducted on selected specimens of the laser surface treated flat sheets trials. The second stage involved surface treatment of the hourglass fatigue specimen. This preliminary work allowed for the type and influence of treatment strategy to be analysed. The influence of treatment strategy on the depth of penetration was established with an emphasis on achieving homogeneity of the laser surface treated zone’s depth of penetration around the complete cylindrical specimen’s diameter. The final matrix involved varying laser power, scanning speed and focus position and the specimens were characterised by comparing hardness, residual stresses and microstructure. The results showed that laser surface treatment changed the hardness profile of the near surface of the specimen owing to the introduction of a homogenous microstructure at the surface as compared to a friction welded specimen. The microstructure was resolved using electron backscatter diffraction. A fully α-lamella microstructure was observed in the two specimens analysed at a position of 200 μm from the surface. The α-lamella had different width sizes with the low-power density specimen having a very fine microstructure as compared to that of the high-power density specimen. EBSD phase maps were also analysed for the parent, rotary friction welded only and friction welded laser surface treated specimens. The laser treated specimens showed virtually no β phase present as compared to the parent and rotary friction welded only specimens. LST processing improved the fatigue properties of the RFW specimens. The position of failure shifted from the HAZ to outside the RFW joint. This change in position was attributed to the surface modification by LST thereby introducing a more homogenous microstructure at the surface of the specimen. Additionally, it was also observed that the power density had an important role to play in the fatigue properties of the laser surface treated specimens. The high-power density LST specimens had a low fatigue limit compared to the low-power density specimens. The low fatigue limit at high- power density correlated with the residual stress results where the high-power density specimen had the highest attained surface tensile axial residual stresses. In conclusion, the main influences of laser surface treatment of small friction welded Ti-6Al-4V ELI components relate to an increase in fatigue properties by shifting crack initiation sites to less stressed areas. In this way, laser surface treatment could assist in the optimisation of manufacturing methodologies for small near net shape complex geometry components. The uniform and homogenous microstructure eliminates or reduces microstructural variations as observed in as welded components, reducing weld zone hardness variation. Additionally, the study showed that the introduction of a near surface refined microstructure inhibited crack initiation in the welded region.
- Full Text:
- Date Issued: 2019
- Authors: Tsikayi, Davies Shamiso
- Date: 2019
- Subjects: Lasers -- Industrial applications , Friction welding Pressure welding Metals -- Research
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/43823 , vital:37050
- Description: This manuscript details a study on laser surface treatment, a surface modification technique that is an easily flexible way of improving material surface properties of complex geometries. The research explored the potential of laser surface modification/treatment as a post welding surface processing technique for RFW Ti-6Al-4V ELI components by evaluating the microstructural effects, influence on fatigue life and the depth and magnitude of residual stresses induced. The outcome of this study reveals how post processing by laser surface modification affects crack initiation hence fatigue life and further explains mechanisms potentially contributing to enhanced joint properties. This study was accomplished by investigating the effect of laser surface treatment on surface properties of hourglass cylindrical rotary friction welded Ti-6Al-4V ELI specimens. Preliminary work was done in two stages. The first stage involved conducting laser surface treatment on 3 mm Ti-6Al-4V sheets. In this stage, an understanding of the process variables concerning the laser surface treatment process characteristics was established. Laser power and focus position were varied whilst scanning speed was kept constant. The observed macrographs were quantified in terms of laser penetration depth and width. A hardness and microstructural analysis was also conducted on selected specimens of the laser surface treated flat sheets trials. The second stage involved surface treatment of the hourglass fatigue specimen. This preliminary work allowed for the type and influence of treatment strategy to be analysed. The influence of treatment strategy on the depth of penetration was established with an emphasis on achieving homogeneity of the laser surface treated zone’s depth of penetration around the complete cylindrical specimen’s diameter. The final matrix involved varying laser power, scanning speed and focus position and the specimens were characterised by comparing hardness, residual stresses and microstructure. The results showed that laser surface treatment changed the hardness profile of the near surface of the specimen owing to the introduction of a homogenous microstructure at the surface as compared to a friction welded specimen. The microstructure was resolved using electron backscatter diffraction. A fully α-lamella microstructure was observed in the two specimens analysed at a position of 200 μm from the surface. The α-lamella had different width sizes with the low-power density specimen having a very fine microstructure as compared to that of the high-power density specimen. EBSD phase maps were also analysed for the parent, rotary friction welded only and friction welded laser surface treated specimens. The laser treated specimens showed virtually no β phase present as compared to the parent and rotary friction welded only specimens. LST processing improved the fatigue properties of the RFW specimens. The position of failure shifted from the HAZ to outside the RFW joint. This change in position was attributed to the surface modification by LST thereby introducing a more homogenous microstructure at the surface of the specimen. Additionally, it was also observed that the power density had an important role to play in the fatigue properties of the laser surface treated specimens. The high-power density LST specimens had a low fatigue limit compared to the low-power density specimens. The low fatigue limit at high- power density correlated with the residual stress results where the high-power density specimen had the highest attained surface tensile axial residual stresses. In conclusion, the main influences of laser surface treatment of small friction welded Ti-6Al-4V ELI components relate to an increase in fatigue properties by shifting crack initiation sites to less stressed areas. In this way, laser surface treatment could assist in the optimisation of manufacturing methodologies for small near net shape complex geometry components. The uniform and homogenous microstructure eliminates or reduces microstructural variations as observed in as welded components, reducing weld zone hardness variation. Additionally, the study showed that the introduction of a near surface refined microstructure inhibited crack initiation in the welded region.
- Full Text:
- Date Issued: 2019
Innovation: its impact on the success of construction micro, small, and medium enterprises in northern Nigeria
- Authors: Tsado, Abel John
- Date: 2019
- Subjects: Construction industry -- Nigeria , Business enterprises -- Nigeria Success in business -- Nigeria Economics—Environmental aspects
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/44951 , vital:38191
- Description: There is growing recognition of the important role Construction Micro, Small and Medium Enterprises (CMSMEs) play in economic development. In 2013, Nigeria had about 36,994,578 Micro, Small, and Medium Enterprises (MSMEs) and 731,303 CMSMEs, about 1.99% of the total number of MSMEs in the country. However, 50% of CMSMEs in Nigeria close down within their first five years of existence. Consequently, only about 10% of CMSMEs in Nigeria survive, thrive, and grow to maturity. Enterprises failing within so short a time, portend a huge problem surrounding CMSME innovation and success. While literature seems to indicate innovation as the likely way out of CMSMEs failure, few researchers have considered the connection between CMSMEs innovation and their success. Hence, this research aimed to explore the effect of innovation(s) and innovation systems on the success of the Northern Nigerian CMSMEs. The research objectives were: to identify the types of innovation that are predominant in/peculiar to the Northern Nigerian CMSMEs; to determine how the types of innovation impact the success of the Northern Nigerian CMSMEs; to establish what the innovation systems that manage the innovation of the Northern Nigerian CMSMEs are; and, to determine how the innovation systems, promote innovation among the Northern Nigerian CMSMEs. Qualitative research method was utilised; consisting of 17 recorded interviews within Northern Nigerian which is the study area. The interview also employed structured interview guide, comprising structured open-ended questions to ensure consistency and rigour in the data collection process. The research adopted two stage non-probabilistic sampling, comprising judgmental and snowballing sampling for stage one and two respectively. In stage one, participants were drawn judgmentally based on their innovation and in stage two, the sample size was expanded, using a snowballing sampling technique where the participants in stage one suggested other participants who had also been innovative. Data collected were transcribed and open coded, while the codes for innovation types, and innovation impact on CMSME success were developed with the aid of a deductive code earlier developed from literature. The code occurrences were determined and categorised, and themes were developed. These themes were then subjected to interpretation and analysis. The research findings indicate that the predominant type of innovations within the CMSMEs in the northern part of Nigeria are product innovation, management innovation and service innovation. In addition, there are, technological application innovations, logistics innovations and labour innovations. These innovations impact on the profit, capital, customers, workers and the products of the CMSMEs studied. The innovations are responsible for the CMSMEs success periods, reasons for success and their salient points of success. Therefore, the research concludes that innovation impacts on the studied CMSMEs success. Consequently, the research achieved its aim. The study also discovered an absence of systems that support the innovation of CMSMEs in the northern part of Nigeria. Through this research, an innovation system framework has been developed and it is recommended that it be implemented because of the observed lack of innovation systems in Nigeria.
- Full Text:
- Date Issued: 2019
- Authors: Tsado, Abel John
- Date: 2019
- Subjects: Construction industry -- Nigeria , Business enterprises -- Nigeria Success in business -- Nigeria Economics—Environmental aspects
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/44951 , vital:38191
- Description: There is growing recognition of the important role Construction Micro, Small and Medium Enterprises (CMSMEs) play in economic development. In 2013, Nigeria had about 36,994,578 Micro, Small, and Medium Enterprises (MSMEs) and 731,303 CMSMEs, about 1.99% of the total number of MSMEs in the country. However, 50% of CMSMEs in Nigeria close down within their first five years of existence. Consequently, only about 10% of CMSMEs in Nigeria survive, thrive, and grow to maturity. Enterprises failing within so short a time, portend a huge problem surrounding CMSME innovation and success. While literature seems to indicate innovation as the likely way out of CMSMEs failure, few researchers have considered the connection between CMSMEs innovation and their success. Hence, this research aimed to explore the effect of innovation(s) and innovation systems on the success of the Northern Nigerian CMSMEs. The research objectives were: to identify the types of innovation that are predominant in/peculiar to the Northern Nigerian CMSMEs; to determine how the types of innovation impact the success of the Northern Nigerian CMSMEs; to establish what the innovation systems that manage the innovation of the Northern Nigerian CMSMEs are; and, to determine how the innovation systems, promote innovation among the Northern Nigerian CMSMEs. Qualitative research method was utilised; consisting of 17 recorded interviews within Northern Nigerian which is the study area. The interview also employed structured interview guide, comprising structured open-ended questions to ensure consistency and rigour in the data collection process. The research adopted two stage non-probabilistic sampling, comprising judgmental and snowballing sampling for stage one and two respectively. In stage one, participants were drawn judgmentally based on their innovation and in stage two, the sample size was expanded, using a snowballing sampling technique where the participants in stage one suggested other participants who had also been innovative. Data collected were transcribed and open coded, while the codes for innovation types, and innovation impact on CMSME success were developed with the aid of a deductive code earlier developed from literature. The code occurrences were determined and categorised, and themes were developed. These themes were then subjected to interpretation and analysis. The research findings indicate that the predominant type of innovations within the CMSMEs in the northern part of Nigeria are product innovation, management innovation and service innovation. In addition, there are, technological application innovations, logistics innovations and labour innovations. These innovations impact on the profit, capital, customers, workers and the products of the CMSMEs studied. The innovations are responsible for the CMSMEs success periods, reasons for success and their salient points of success. Therefore, the research concludes that innovation impacts on the studied CMSMEs success. Consequently, the research achieved its aim. The study also discovered an absence of systems that support the innovation of CMSMEs in the northern part of Nigeria. Through this research, an innovation system framework has been developed and it is recommended that it be implemented because of the observed lack of innovation systems in Nigeria.
- Full Text:
- Date Issued: 2019
Integration of indigenous knowledge in the intermediate phase school curriculum in a selected education district in the Eastern Cape, South Africa
- Mkosi, Nkosinathi Ndumiso Lizo
- Authors: Mkosi, Nkosinathi Ndumiso Lizo
- Date: 2019
- Subjects: Education -- Curricula -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/16136 , vital:40671
- Description: The aims and principles of the post-apartheid South African school curricula, ranging from the Revised National Curriculum Statement Grades R-9 and the National Curriculum Statement Grades 10-12, to include the Curriculum and Assessment Policy Statements (Grades 1-12), have been aligned with the aims and principles of the South African Constitution. The aims and principles, among others, speak to the establishment of human rights, inclusivity, environmental and social justice, and valuing of indigenous knowledge systems. These are the bedrock of all the subjects and do not necessarily confine themselves to the science subjects only; even though the call of inclusion of indigenous knowledge in the sciences is oversubscribed. There has been concerns raised variously that the integration of indigenous knowledge systems in the curriculum, generally, and in the teaching of the respective subjects, particularly, does not necessarily happen as it should be. Thus, the purpose of this mixed methods approach study that adopted a concurrent triangulation mixed methods design and premised on the postpositivist paradigm investigated the integration of indigenous knowledge in the Intermediate Phase school curriculum in a selected Education District in the Eastern Cape Province, South Africa. The guiding lenses adopted for this study were two-fold. The main primary theoretical framework drew from three integration theories: (a) Huang and Newell’s (2003) Knowledge Integration Processes and Dynamics notions; (b) Beane’s (1995) Curriculum Integration and the Disciplines of Knowledge and (c) Harden’s (2000) Integration ladder: A Tool for Curriculum Planning and Evaluation. The ‘secondary’ lens of analysis, which the researcher named, the ‘supplemental framework’, was constituted by notions and constructs derived from the indigenous knowledge systems discourses and postcolonial notions and constructs. The study revealed, among other findings, that (i) whilst a majority of teachers claimed to integrate IK in their classrooms, a significant number did not, and those who claimed to be integrating were unsure about how to integrate (ii) the majority of teachers, HoDs and Subject Advisors were either poorly trained or did not receive any training in the integration of IK (iii) the support and monitoring of IK integration was poor to non-existent. Thus, the study proposes a model, the Integrative Indigenous Knowledge Integration Support and Monitoring Model (IIKISMM), which may act as a framework for the coordination of the support and monitoring of IK integration in the school curriculum. There are significant recommendations offered by the study to teachers and policy makers with regards the integration of indigenous knowledge systems in the school curriculum. Also offered by the study are possibilities for further research in the integration of indigenous knowledge system in the curriculum.
- Full Text:
- Date Issued: 2019
- Authors: Mkosi, Nkosinathi Ndumiso Lizo
- Date: 2019
- Subjects: Education -- Curricula -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/16136 , vital:40671
- Description: The aims and principles of the post-apartheid South African school curricula, ranging from the Revised National Curriculum Statement Grades R-9 and the National Curriculum Statement Grades 10-12, to include the Curriculum and Assessment Policy Statements (Grades 1-12), have been aligned with the aims and principles of the South African Constitution. The aims and principles, among others, speak to the establishment of human rights, inclusivity, environmental and social justice, and valuing of indigenous knowledge systems. These are the bedrock of all the subjects and do not necessarily confine themselves to the science subjects only; even though the call of inclusion of indigenous knowledge in the sciences is oversubscribed. There has been concerns raised variously that the integration of indigenous knowledge systems in the curriculum, generally, and in the teaching of the respective subjects, particularly, does not necessarily happen as it should be. Thus, the purpose of this mixed methods approach study that adopted a concurrent triangulation mixed methods design and premised on the postpositivist paradigm investigated the integration of indigenous knowledge in the Intermediate Phase school curriculum in a selected Education District in the Eastern Cape Province, South Africa. The guiding lenses adopted for this study were two-fold. The main primary theoretical framework drew from three integration theories: (a) Huang and Newell’s (2003) Knowledge Integration Processes and Dynamics notions; (b) Beane’s (1995) Curriculum Integration and the Disciplines of Knowledge and (c) Harden’s (2000) Integration ladder: A Tool for Curriculum Planning and Evaluation. The ‘secondary’ lens of analysis, which the researcher named, the ‘supplemental framework’, was constituted by notions and constructs derived from the indigenous knowledge systems discourses and postcolonial notions and constructs. The study revealed, among other findings, that (i) whilst a majority of teachers claimed to integrate IK in their classrooms, a significant number did not, and those who claimed to be integrating were unsure about how to integrate (ii) the majority of teachers, HoDs and Subject Advisors were either poorly trained or did not receive any training in the integration of IK (iii) the support and monitoring of IK integration was poor to non-existent. Thus, the study proposes a model, the Integrative Indigenous Knowledge Integration Support and Monitoring Model (IIKISMM), which may act as a framework for the coordination of the support and monitoring of IK integration in the school curriculum. There are significant recommendations offered by the study to teachers and policy makers with regards the integration of indigenous knowledge systems in the school curriculum. Also offered by the study are possibilities for further research in the integration of indigenous knowledge system in the curriculum.
- Full Text:
- Date Issued: 2019
Management capacity within small and medium tourism enterprises (SMTEs)
- Authors: Mxunyelwa, Siyabonga
- Date: 2019
- Subjects: Small business -- South Africa -- Eastern Cape -- Management , Tourism -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/41708 , vital:36574
- Description: The small to medium tourism enterprises are identified as important contributors to the growth of the local and regional economies and creates much needed entrepreneurial ventures. Universally, small to medium tourism enterprises play a significant role in the tourism sector. The small businesses are in many instances deemed to facing risk to economic environmental challenges and face uphill battles to operate their enterprises in a sustainable manner. Management of these enterprises by owners and managers seems to face challenges. This study focuses on small to medium tourism enterprises in the Eastern Cape Province, South Africa, which faces the triple threat challenges of poverty, inequality and unemployment, and is one of the economically poorest provinces of South Africa. In an endeavour to create a trajectory for progression and development of small to medium tourism enterprises, owners and managers are required to undertake management capacity programmes to deal with the problems that confront the enterprise on a daily basis. The study examines the factors impacting on management capacity with specific focus on the small to medium tourism enterprises in the Eastern Cape Province, South Africa. Management capacity is paramount as it builds managerial competency and has become significant to the small business economy, as these enterprises make every effort to avoid discontinuation. Management capacity improves business performance and small enterprises require help in order to have a broader understanding of issues that can be an impediment to address the challenges in the business environment. The factors that could impact on management capacity within the enterprises are the focus of this research. The eleven main factors were identified, namely skills development; reasons for starting a business; business challenges; strategic and management knowledge; business leadership; business resources, business environment; business communication; business organisational leadership; organisational strategy; and organisational information factors. Furthermore, the study examined the level of influence of these factors on the management capacity of small businesses in the tourism and hospitality sector in the Eastern Cape and investigated the relationships between these factors. A descriptive research design and a quantitative approach were considered suitable for this study. A systematic random sampling technique was utilised to choose a sample of 320 business respondents from the 2012 database of the Eastern Cape Parks and Tourism Agency, comprising of formally registered small tourism businesses. A total of 310 usable questionnaires was finally obtained. In this study descriptive and inferential statistics were applied. Descriptive statistics were captured to highlight the owners and managers’ general characteristics and to consolidate their measurement scores. Utilising inferential statistics, the study undertook an investigation into relationships between demographic variables and business characteristics. Furthermore, an investigation of the relationships amongst the following factors: skills development; reasons for starting a business; business challenges; strategic and management knowledge; business leadership; business resources, business environment; business communication; business organisational leadership; organisational strategy and organisational information factors was undertaken. Data were subjected to exploratory factor analysis and both the validity and reliability of the research instrument was assessed. The research findings support an overall significant correlation between management capacity and skills development; reasons for starting a business; business challenges; strategic and management knowledge; business leadership; business resources, business environment; business communication; business organisational leadership; organisational strategy and organisational information. The study also explored the relationship between demographics and business characteristics. A significant relationship was found between business characteristics and variables in the demographic profile, namely the gender of owners/managers, educational levels, qualifications, and gross annual turnover. What follows is a summation of the most significant contributions of this research. The overview of the significance of the tourism sector in the economy and the role of small businesses in the tourism and hospitality industry of the Eastern Cape will benefit researchers and potential owners/managers who have an interest in this developing sector. The study enhances the understanding of the factors that relate to management capacity. The study has established a profile of SMTE sector in the Eastern Cape, South Africa, which can play a significant role for future research. This research makes a contribution to the largely under-researched area of management capacity in small to medium tourism enterprises. Recommendations for owners/managers and consideration of future research included the following. Owners/managers need to have management skills and a strong strategic focus. Through management capacity the needs of the business will be addressed, and capacity building programmes can be tailored to maximise the benefits for owners/managers of SMTEs, thereby improving business performance and avoiding high failure rate. Managers need to be effectively trained to deal with business needs. The management of the business plays a pivotal role in the performance of the enterprise. Managers must be skilled with regards to developing strategic plans, marketing plans, and business plans, thus enhancing management capacity. Longitudinal studies can be undertaken to investigating the same factors which could impact on management capacity. It is recommended that this study be replicated across the global spectrum in order to analyse the factors that impact on management capacity of small to medium tourism businesses of other countries.
- Full Text:
- Date Issued: 2019
- Authors: Mxunyelwa, Siyabonga
- Date: 2019
- Subjects: Small business -- South Africa -- Eastern Cape -- Management , Tourism -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/41708 , vital:36574
- Description: The small to medium tourism enterprises are identified as important contributors to the growth of the local and regional economies and creates much needed entrepreneurial ventures. Universally, small to medium tourism enterprises play a significant role in the tourism sector. The small businesses are in many instances deemed to facing risk to economic environmental challenges and face uphill battles to operate their enterprises in a sustainable manner. Management of these enterprises by owners and managers seems to face challenges. This study focuses on small to medium tourism enterprises in the Eastern Cape Province, South Africa, which faces the triple threat challenges of poverty, inequality and unemployment, and is one of the economically poorest provinces of South Africa. In an endeavour to create a trajectory for progression and development of small to medium tourism enterprises, owners and managers are required to undertake management capacity programmes to deal with the problems that confront the enterprise on a daily basis. The study examines the factors impacting on management capacity with specific focus on the small to medium tourism enterprises in the Eastern Cape Province, South Africa. Management capacity is paramount as it builds managerial competency and has become significant to the small business economy, as these enterprises make every effort to avoid discontinuation. Management capacity improves business performance and small enterprises require help in order to have a broader understanding of issues that can be an impediment to address the challenges in the business environment. The factors that could impact on management capacity within the enterprises are the focus of this research. The eleven main factors were identified, namely skills development; reasons for starting a business; business challenges; strategic and management knowledge; business leadership; business resources, business environment; business communication; business organisational leadership; organisational strategy; and organisational information factors. Furthermore, the study examined the level of influence of these factors on the management capacity of small businesses in the tourism and hospitality sector in the Eastern Cape and investigated the relationships between these factors. A descriptive research design and a quantitative approach were considered suitable for this study. A systematic random sampling technique was utilised to choose a sample of 320 business respondents from the 2012 database of the Eastern Cape Parks and Tourism Agency, comprising of formally registered small tourism businesses. A total of 310 usable questionnaires was finally obtained. In this study descriptive and inferential statistics were applied. Descriptive statistics were captured to highlight the owners and managers’ general characteristics and to consolidate their measurement scores. Utilising inferential statistics, the study undertook an investigation into relationships between demographic variables and business characteristics. Furthermore, an investigation of the relationships amongst the following factors: skills development; reasons for starting a business; business challenges; strategic and management knowledge; business leadership; business resources, business environment; business communication; business organisational leadership; organisational strategy and organisational information factors was undertaken. Data were subjected to exploratory factor analysis and both the validity and reliability of the research instrument was assessed. The research findings support an overall significant correlation between management capacity and skills development; reasons for starting a business; business challenges; strategic and management knowledge; business leadership; business resources, business environment; business communication; business organisational leadership; organisational strategy and organisational information. The study also explored the relationship between demographics and business characteristics. A significant relationship was found between business characteristics and variables in the demographic profile, namely the gender of owners/managers, educational levels, qualifications, and gross annual turnover. What follows is a summation of the most significant contributions of this research. The overview of the significance of the tourism sector in the economy and the role of small businesses in the tourism and hospitality industry of the Eastern Cape will benefit researchers and potential owners/managers who have an interest in this developing sector. The study enhances the understanding of the factors that relate to management capacity. The study has established a profile of SMTE sector in the Eastern Cape, South Africa, which can play a significant role for future research. This research makes a contribution to the largely under-researched area of management capacity in small to medium tourism enterprises. Recommendations for owners/managers and consideration of future research included the following. Owners/managers need to have management skills and a strong strategic focus. Through management capacity the needs of the business will be addressed, and capacity building programmes can be tailored to maximise the benefits for owners/managers of SMTEs, thereby improving business performance and avoiding high failure rate. Managers need to be effectively trained to deal with business needs. The management of the business plays a pivotal role in the performance of the enterprise. Managers must be skilled with regards to developing strategic plans, marketing plans, and business plans, thus enhancing management capacity. Longitudinal studies can be undertaken to investigating the same factors which could impact on management capacity. It is recommended that this study be replicated across the global spectrum in order to analyse the factors that impact on management capacity of small to medium tourism businesses of other countries.
- Full Text:
- Date Issued: 2019
Mechanisms and modes of β-N-methylamino-lalanine neurotoxicity: the basis for designing therapies
- Authors: Van Onselen, Rianita
- Date: 2019
- Subjects: Cyanobacteria , Amino acids -- Toxicology , Neurotoxic agents
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/32971 , vital:32483
- Description: Since the discovery of the non-canonical amino acid β-N-methylamino-L-alanine (BMAA) and the demonstration of its acute neurotoxicity in chicks and rats, it has been postulated that BMAA might contribute to the development of neurodegenerative diseases worldwide due to its presence in numerous aquatic and terrestrial food webs. This hypothesized link was widely criticized because of the inability to reproduce symptoms in a BMAA-exposed animal model that resembled the symptoms observed in humans, and for the inability to achieve significant levels of toxicity in in vitro models via the postulated mechanisms of toxicity. The most widely described mechanism of BMAA toxicity was excitotoxicity by over-excitation of ionotropic and/or metabotropic glutamate receptors following activation by BMAA. However, the excitotoxic potency of BMAA is much lower than those of other known excitotoxins and it was not known whether BMAA could accumulate in significant concentrations in synapses to cause the said excitotoxicity. Therefore, uptake of BMAA into synaptic vesicles from where it can be released into synapses in high concentrations, was investigated and it was found that, unlike the uptake that was observed for glutamate, BMAA was not taken up into synaptic vesicles. This discovery suggests that BMAA is not released into synapses via synaptic vesicles and that excitotoxicity is an unlikely mechanism of BMAA toxicity in mammalian systems. Misincorporation of BMAA into proteins in the place of L-serine was suggested to be an important mechanism of BMAA toxicity that could lead to protein misfolding and the subsequent protein aggregates that are typically found in the central nervous system (CNS) of neurodegenerative disease patients. However, previous studies in prokaryotes and in a rat pheochromocytoma PC12 cell line showed that misincorporation of BMAA does not occur to any significant extent. However, these studies were criticized for not using human-derived model systems to show that misincorporation does not occur, and it was argued that due to differences in mitochondrial protein synthesis mechanisms, misincorporation of BMAA into human proteins could not be ruled out as a possible mechanism of toxicity. Therefore, misincorporation of BMAA was investigated in a number of human-derived non-neuronal cell lines and directly compared to the misincorporation of other known amino acid analogues. No evidence of misincorporation of BMAA into these cell lines was obtained and therefore it was concluded that misincorporation of BMAA into proteins does not occur in human-derived cell models. Although misincorporation of BMAA into proteins was refuted as a mechanism of toxicity, the strong interactions between BMAA and proteins that require extensive purification procedures to remove the associated BMAA, could not be discounted as a possible contributor to the toxicity of BMAA. Cell-free interactions between BMAA and enzymes, which resulted in reduced activity, were described previously but the nature of these interactions was never determined. Therefore, the direct interactions between BMAA and a range of commercial proteins and melanin (that is known to also have a strong affinity for BMAA) were investigated in an attempt to describe the nature of these interactions. It was discovered that BMAA has a high affinity for hydroxyl groups, and that if these hydroxyl groups in the form of hydroxyl containing amino acid residues occurred in important regulatory or active sites of proteins, BMAA reduced the enzyme activity. Catalase was subsequently selected as an important enzyme required for the maintenance of the delicate reactive oxygen species (ROS) balance in the CNS, to test the effect of BMAA on the activity of the enzyme. BMAA inhibited a human commercial extract of catalase in a cell free system, and this inhibition appeared to be non-competitive in nature. Subsequently, catalase in an extract from a human cell line was also shown to be inhibited by BMAA and it was concluded that this BMAA induced inhibition of catalase could be an important contributor to the toxicity of BMAA in in vivo systems. The affinity of BMAA for hydroxyl groups, especially the reactive L-tyrosine side chain hydroxyl, was recognized as a possible mechanism that can be utilized to protect against the toxicity of BMAA. It was subsequently shown that excess concentrations of L-serine and L-tyrosine could protect against the BMAA-induced enzyme inhibition and improper folding of proteins in a cell-free system. By administering an equimolar concentration of either L-phenylalanine (the soluble precursor of L-tyrosine) or L-serine an hour before administration of BMAA in a rat model, the BMAA-induced neurotoxicity was greatly reduced, especially by treatment with L-phenylalanine, which resulted in a decrease of between 60-70% in the observed neuropathologies. It was recognized that the protection offered by L-phenylalanine was greater than would be expected if protection was by virtue of direct hydroxyl binding alone and it was subsequently hypothesized that the conversion of L-phenylalanine to dopamine could have contributed to the observed protection. Subsequently, the possible protection offered by dopamine, administered as L-DOPA, against BMAA neurotoxicity was investigated in the same neonatal rat model and compared to the protection offered by L-tyrosine. It was discovered that dopamine protected against the BMAAinduced neuronal cell losses in the hippocampus, striatum and spinal cord but it was not as efficient as L-tyrosine in protection against the BMAA-induced proteinopathies, suggesting two distinct mechanisms of BMAA toxicity, one of which is a depletion of dopamine, which had not been previously described. Finally, the nature of the BMAA-induced dopamine depletion was investigated by administering BMAA in combination with other dopaminergic modifiers viz. apomorphine (a D1/D2 receptor agonist), a dopamine transporter inhibitor (GBR12783) and reserpine (a vesicular monoamine transporter -VMAT2- inhibitor) to the neonatal rat model in an attempt to describe how BMAA functions as a dopaminergic toxin. Based on these results it was concluded that BMAA inhibits uptake of dopamine into synaptic vesicles by inhibiting VMAT2-mediated uptake of dopamine, which causes neuronal loss in the hippocampus, striatum and substantia nigra pars compacta, and that the BMAA-induced inhibition of catalase contributes significantly to the toxicity of BMAA by causing an accumulation of hydrogen peroxide in the hippocampus, striatum and spinal cord, which results in extensive neuronal damage in these areas. This work was the first to thoroughly investigate the mechanisms that explain the observed pathologies caused by BMAA in an in vivo model, and was the first to suggest that BMAA can reduce the dopamine in the CNS by inhibiting VMAT2-mediated uptake of dopamine into synaptic vesicles, and increase damage by reactive oxygen species by inhibiting catalase. BMAA is therefore a multimechanistic and multimodal.
- Full Text:
- Date Issued: 2019
- Authors: Van Onselen, Rianita
- Date: 2019
- Subjects: Cyanobacteria , Amino acids -- Toxicology , Neurotoxic agents
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/32971 , vital:32483
- Description: Since the discovery of the non-canonical amino acid β-N-methylamino-L-alanine (BMAA) and the demonstration of its acute neurotoxicity in chicks and rats, it has been postulated that BMAA might contribute to the development of neurodegenerative diseases worldwide due to its presence in numerous aquatic and terrestrial food webs. This hypothesized link was widely criticized because of the inability to reproduce symptoms in a BMAA-exposed animal model that resembled the symptoms observed in humans, and for the inability to achieve significant levels of toxicity in in vitro models via the postulated mechanisms of toxicity. The most widely described mechanism of BMAA toxicity was excitotoxicity by over-excitation of ionotropic and/or metabotropic glutamate receptors following activation by BMAA. However, the excitotoxic potency of BMAA is much lower than those of other known excitotoxins and it was not known whether BMAA could accumulate in significant concentrations in synapses to cause the said excitotoxicity. Therefore, uptake of BMAA into synaptic vesicles from where it can be released into synapses in high concentrations, was investigated and it was found that, unlike the uptake that was observed for glutamate, BMAA was not taken up into synaptic vesicles. This discovery suggests that BMAA is not released into synapses via synaptic vesicles and that excitotoxicity is an unlikely mechanism of BMAA toxicity in mammalian systems. Misincorporation of BMAA into proteins in the place of L-serine was suggested to be an important mechanism of BMAA toxicity that could lead to protein misfolding and the subsequent protein aggregates that are typically found in the central nervous system (CNS) of neurodegenerative disease patients. However, previous studies in prokaryotes and in a rat pheochromocytoma PC12 cell line showed that misincorporation of BMAA does not occur to any significant extent. However, these studies were criticized for not using human-derived model systems to show that misincorporation does not occur, and it was argued that due to differences in mitochondrial protein synthesis mechanisms, misincorporation of BMAA into human proteins could not be ruled out as a possible mechanism of toxicity. Therefore, misincorporation of BMAA was investigated in a number of human-derived non-neuronal cell lines and directly compared to the misincorporation of other known amino acid analogues. No evidence of misincorporation of BMAA into these cell lines was obtained and therefore it was concluded that misincorporation of BMAA into proteins does not occur in human-derived cell models. Although misincorporation of BMAA into proteins was refuted as a mechanism of toxicity, the strong interactions between BMAA and proteins that require extensive purification procedures to remove the associated BMAA, could not be discounted as a possible contributor to the toxicity of BMAA. Cell-free interactions between BMAA and enzymes, which resulted in reduced activity, were described previously but the nature of these interactions was never determined. Therefore, the direct interactions between BMAA and a range of commercial proteins and melanin (that is known to also have a strong affinity for BMAA) were investigated in an attempt to describe the nature of these interactions. It was discovered that BMAA has a high affinity for hydroxyl groups, and that if these hydroxyl groups in the form of hydroxyl containing amino acid residues occurred in important regulatory or active sites of proteins, BMAA reduced the enzyme activity. Catalase was subsequently selected as an important enzyme required for the maintenance of the delicate reactive oxygen species (ROS) balance in the CNS, to test the effect of BMAA on the activity of the enzyme. BMAA inhibited a human commercial extract of catalase in a cell free system, and this inhibition appeared to be non-competitive in nature. Subsequently, catalase in an extract from a human cell line was also shown to be inhibited by BMAA and it was concluded that this BMAA induced inhibition of catalase could be an important contributor to the toxicity of BMAA in in vivo systems. The affinity of BMAA for hydroxyl groups, especially the reactive L-tyrosine side chain hydroxyl, was recognized as a possible mechanism that can be utilized to protect against the toxicity of BMAA. It was subsequently shown that excess concentrations of L-serine and L-tyrosine could protect against the BMAA-induced enzyme inhibition and improper folding of proteins in a cell-free system. By administering an equimolar concentration of either L-phenylalanine (the soluble precursor of L-tyrosine) or L-serine an hour before administration of BMAA in a rat model, the BMAA-induced neurotoxicity was greatly reduced, especially by treatment with L-phenylalanine, which resulted in a decrease of between 60-70% in the observed neuropathologies. It was recognized that the protection offered by L-phenylalanine was greater than would be expected if protection was by virtue of direct hydroxyl binding alone and it was subsequently hypothesized that the conversion of L-phenylalanine to dopamine could have contributed to the observed protection. Subsequently, the possible protection offered by dopamine, administered as L-DOPA, against BMAA neurotoxicity was investigated in the same neonatal rat model and compared to the protection offered by L-tyrosine. It was discovered that dopamine protected against the BMAAinduced neuronal cell losses in the hippocampus, striatum and spinal cord but it was not as efficient as L-tyrosine in protection against the BMAA-induced proteinopathies, suggesting two distinct mechanisms of BMAA toxicity, one of which is a depletion of dopamine, which had not been previously described. Finally, the nature of the BMAA-induced dopamine depletion was investigated by administering BMAA in combination with other dopaminergic modifiers viz. apomorphine (a D1/D2 receptor agonist), a dopamine transporter inhibitor (GBR12783) and reserpine (a vesicular monoamine transporter -VMAT2- inhibitor) to the neonatal rat model in an attempt to describe how BMAA functions as a dopaminergic toxin. Based on these results it was concluded that BMAA inhibits uptake of dopamine into synaptic vesicles by inhibiting VMAT2-mediated uptake of dopamine, which causes neuronal loss in the hippocampus, striatum and substantia nigra pars compacta, and that the BMAA-induced inhibition of catalase contributes significantly to the toxicity of BMAA by causing an accumulation of hydrogen peroxide in the hippocampus, striatum and spinal cord, which results in extensive neuronal damage in these areas. This work was the first to thoroughly investigate the mechanisms that explain the observed pathologies caused by BMAA in an in vivo model, and was the first to suggest that BMAA can reduce the dopamine in the CNS by inhibiting VMAT2-mediated uptake of dopamine into synaptic vesicles, and increase damage by reactive oxygen species by inhibiting catalase. BMAA is therefore a multimechanistic and multimodal.
- Full Text:
- Date Issued: 2019
Microalgae as indicators of environmental change in the St Lucia estuarine system
- Authors: Nunes, Monique
- Date: 2019
- Subjects: Microalgae -- South Africa -- St Lucia estuarine
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/31165 , vital:31333
- Description: The St Lucia system represents 56% of the estuarine habitat area in South Africa. This dynamic estuarine lake responds to a complex interaction of climatic and anthropogenic drivers. There has been a long history of human interventions and the extended drought (2002-2012) led to major changes. In 1952, the inlet shared between the estuarine system and the Mfolozi River was artificially separated, which significantly reduced freshwater inflow. The systems were separated because of the silt load from the expanding agricultural activities in the Mfolozi River catchment. The drought prompted a critical review of re-establishing the historic connection, and in July 2012, the beach spillway was excavated marking the start of restoring connectivity. Increased rainfall coupled with the partial re-connection with the agriculturally-impacted Mfolozi River shifted the St Lucia estuarine system to a new wet phase. This study investigated the microalgal dynamics of the estuarine system as it transitioned to this new wet phase. Results showed that the phytoplankton and microphytobenthos (MPB) biomass was low (< 5 ug l-1 and < 60 mg m-2 respectively) throughout the system due to nutrient and light availability, water residence time and sediment type. The increased freshwater inflow from the Mfolozi River was limited to the Narrows and available nutrients promoted the growth of cyanobacteria and dinophytes in the water column. Of interest was the presence of the potentially harmful algal species Prorocentrum minimum. A weekly study investigated the relationship between freshwater inflow, phytoplankton succession and the introduction and persistence of harmful microalgal species in the lower reaches. The increased freshwater inflow received from the Mfolozi River has led to a system in a constant state of flux. The changes in salinity, light availability and water residence time, shifted the phytoplankton functional group structure to one where chlorophytes and euglenoids were dominant. The persistence of the nutrient tolerant euglenoids highlighted the influence of the nutrient-enriched freshwater inflow on the phytoplankton functional groups. However, the relative abundance of all functional groups remained low due to the rapid change in environmental conditions. The next step was to test the use of an artificial substrate as a monitoring method to detect nutrient induced change. Findings from the 28-day study showed that epilithic diatom communities growing on glass slides were good indicators of nutrient enrichment. The epilithic algal biomass increased significantly from 1.5 mg m-2 (Day 14) to 6 mg m-2 (Day 21), following peak river inflow. In contrast, the phytoplankton and MPB showed no discernible increase in biomass. Epilithic diatom community diversity, richness and evenness scores declined due to the increasing relative abundance of a single nutrient tolerant species, Cocconeis placentula var. euglypta. The use of diatoms as indicators of change depends on the accuracy of identification to species level. This can be a slow process requiring a high level of taxonomic expertise. Considering that molecular phylogenetic methods are readily used to produce a reliable taxonomic list, the suitability of DNA metabarcoding for diatom monitoring in the St Lucia Estuary was tested. Comparisons between the molecular and morphological method indicated that the diatom taxonomic composition was similar at 9 to 27% for genus level and 2 to 9% at species level. The low taxonomic similarity was related to the large number of unclassified DNA representative sequences included in the molecular inventory due to the incomplete DNA library database. However, the available operational taxonomic units (OTUs) from the molecular method did provide an effective alternative to determine the relevant community diversity estimates required for the application of the South African Estuarine Health Index (EHI). This research has highlighted the dynamic nature of the St Lucia estuarine system and the effectiveness of the microalgal communities to differentiate between the cyclical climatic phases and anthropogenic stressors such as nutrient enrichment.
- Full Text:
- Date Issued: 2019
- Authors: Nunes, Monique
- Date: 2019
- Subjects: Microalgae -- South Africa -- St Lucia estuarine
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/31165 , vital:31333
- Description: The St Lucia system represents 56% of the estuarine habitat area in South Africa. This dynamic estuarine lake responds to a complex interaction of climatic and anthropogenic drivers. There has been a long history of human interventions and the extended drought (2002-2012) led to major changes. In 1952, the inlet shared between the estuarine system and the Mfolozi River was artificially separated, which significantly reduced freshwater inflow. The systems were separated because of the silt load from the expanding agricultural activities in the Mfolozi River catchment. The drought prompted a critical review of re-establishing the historic connection, and in July 2012, the beach spillway was excavated marking the start of restoring connectivity. Increased rainfall coupled with the partial re-connection with the agriculturally-impacted Mfolozi River shifted the St Lucia estuarine system to a new wet phase. This study investigated the microalgal dynamics of the estuarine system as it transitioned to this new wet phase. Results showed that the phytoplankton and microphytobenthos (MPB) biomass was low (< 5 ug l-1 and < 60 mg m-2 respectively) throughout the system due to nutrient and light availability, water residence time and sediment type. The increased freshwater inflow from the Mfolozi River was limited to the Narrows and available nutrients promoted the growth of cyanobacteria and dinophytes in the water column. Of interest was the presence of the potentially harmful algal species Prorocentrum minimum. A weekly study investigated the relationship between freshwater inflow, phytoplankton succession and the introduction and persistence of harmful microalgal species in the lower reaches. The increased freshwater inflow received from the Mfolozi River has led to a system in a constant state of flux. The changes in salinity, light availability and water residence time, shifted the phytoplankton functional group structure to one where chlorophytes and euglenoids were dominant. The persistence of the nutrient tolerant euglenoids highlighted the influence of the nutrient-enriched freshwater inflow on the phytoplankton functional groups. However, the relative abundance of all functional groups remained low due to the rapid change in environmental conditions. The next step was to test the use of an artificial substrate as a monitoring method to detect nutrient induced change. Findings from the 28-day study showed that epilithic diatom communities growing on glass slides were good indicators of nutrient enrichment. The epilithic algal biomass increased significantly from 1.5 mg m-2 (Day 14) to 6 mg m-2 (Day 21), following peak river inflow. In contrast, the phytoplankton and MPB showed no discernible increase in biomass. Epilithic diatom community diversity, richness and evenness scores declined due to the increasing relative abundance of a single nutrient tolerant species, Cocconeis placentula var. euglypta. The use of diatoms as indicators of change depends on the accuracy of identification to species level. This can be a slow process requiring a high level of taxonomic expertise. Considering that molecular phylogenetic methods are readily used to produce a reliable taxonomic list, the suitability of DNA metabarcoding for diatom monitoring in the St Lucia Estuary was tested. Comparisons between the molecular and morphological method indicated that the diatom taxonomic composition was similar at 9 to 27% for genus level and 2 to 9% at species level. The low taxonomic similarity was related to the large number of unclassified DNA representative sequences included in the molecular inventory due to the incomplete DNA library database. However, the available operational taxonomic units (OTUs) from the molecular method did provide an effective alternative to determine the relevant community diversity estimates required for the application of the South African Estuarine Health Index (EHI). This research has highlighted the dynamic nature of the St Lucia estuarine system and the effectiveness of the microalgal communities to differentiate between the cyclical climatic phases and anthropogenic stressors such as nutrient enrichment.
- Full Text:
- Date Issued: 2019
Microstructural evolution of welded creep aged 12% cr martensitic stainless steel
- Authors: Marx, Genevéve
- Date: 2019
- Subjects: Stainless steel -- Welding
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/30766 , vital:31128
- Description: Tempered martensite ferritic (TMF) steels with 9-12% Cr additions are used extensively for high-pressure steam pipes in coal-fired power plants. They operate at temperatures above 500ºC and are consequently susceptible to creep damage. Due to economic reasons, welding must be performed on service exposed materials when a component needs to be replaced. Fusion welding results in the formation of different microstructural regions within the weldment. The primary failure mechanism of TMF steel welded components is Type IV cracking that results from accelerated void formation in the fine-grained heat affected zone (FGHAZ) during creep. Short-term creep-tests performed across weldments made on new and service exposed steels have shown that the weldment consistently fails in the FGHAZ of the service exposed material. This observation has not yet been fully explained since not much is known about the microstructural evolution of creep aged material during welding. Thus, further investigation on the microstructure of welded creep aged material is warranted. The main aim of this thesis was to investigate the microstructural evolution when welding upon creep aged 9-12% Cr martensitic steels using advanced electron microscopy techniques. X20CrMoV12-1 (12% Cr) in the virgin and long-term service-exposed state were investigated. GleebleTM weld simulation of the FGHAZ was performed on the materials. Detailed microstructural investigations were conducted on the parent and simulated FGHAZ materials to analyse the voids, dislocation density, micro-grains, and precipitates (M23C6, MX, Laves, Z-phase) in the materials. Light Microscopy (LM) and Scanning Electron Microscopy (SEM) was used to examine the voids. Twin-jet electropolished specimens were prepared for precipitate, micro-grain and substructure analyses using Transmission Kikuchi Diffraction (TKD) combined with Energy Dispersive Spectrometry (EDS), Concentric Backscatter (CBS) imaging, Energy-Filtered Transmission Electron Microscopy (EFTEM), and Annular Dark-Field Scanning Transmission Electron Microscopy (ADF-STEM) combined with EDS. The precipitates were extracted from the iron matrix using Bulk Replication and further investigated using EFTEM and STEM-EDS.
- Full Text:
- Date Issued: 2019
- Authors: Marx, Genevéve
- Date: 2019
- Subjects: Stainless steel -- Welding
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/30766 , vital:31128
- Description: Tempered martensite ferritic (TMF) steels with 9-12% Cr additions are used extensively for high-pressure steam pipes in coal-fired power plants. They operate at temperatures above 500ºC and are consequently susceptible to creep damage. Due to economic reasons, welding must be performed on service exposed materials when a component needs to be replaced. Fusion welding results in the formation of different microstructural regions within the weldment. The primary failure mechanism of TMF steel welded components is Type IV cracking that results from accelerated void formation in the fine-grained heat affected zone (FGHAZ) during creep. Short-term creep-tests performed across weldments made on new and service exposed steels have shown that the weldment consistently fails in the FGHAZ of the service exposed material. This observation has not yet been fully explained since not much is known about the microstructural evolution of creep aged material during welding. Thus, further investigation on the microstructure of welded creep aged material is warranted. The main aim of this thesis was to investigate the microstructural evolution when welding upon creep aged 9-12% Cr martensitic steels using advanced electron microscopy techniques. X20CrMoV12-1 (12% Cr) in the virgin and long-term service-exposed state were investigated. GleebleTM weld simulation of the FGHAZ was performed on the materials. Detailed microstructural investigations were conducted on the parent and simulated FGHAZ materials to analyse the voids, dislocation density, micro-grains, and precipitates (M23C6, MX, Laves, Z-phase) in the materials. Light Microscopy (LM) and Scanning Electron Microscopy (SEM) was used to examine the voids. Twin-jet electropolished specimens were prepared for precipitate, micro-grain and substructure analyses using Transmission Kikuchi Diffraction (TKD) combined with Energy Dispersive Spectrometry (EDS), Concentric Backscatter (CBS) imaging, Energy-Filtered Transmission Electron Microscopy (EFTEM), and Annular Dark-Field Scanning Transmission Electron Microscopy (ADF-STEM) combined with EDS. The precipitates were extracted from the iron matrix using Bulk Replication and further investigated using EFTEM and STEM-EDS.
- Full Text:
- Date Issued: 2019
Optimising construction project role-player performance
- Authors: Hefer, Andre Le Roux
- Date: 2019
- Subjects: Construction industry -- Management , Project management Performance
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/40316 , vital:36140
- Description: Authors predict major changes in the requirements to manage complex environments in the 21st century. These 21st century challenges, for Project Managers (PM) in the construction industry, are evident through the ongoing perception that the industry performance record is suboptimal. In the pursuit of performance optimisation, management disciplines developed and implemented theories and models not only to achieve what is required, but also to excel and create high-performing teams. In search of project success, researchers have also identified quantifiable variables, models, success factors and other related issues. The PM’s role in the attainment of success has also been widely researched, especially the impact, influence, methods and tools related to the discipline. Nevertheless, the general concern remains, that the performance of the industry is suboptimal. This study therefore aimed to qualitatively evaluate and examine the various factors and influences on performance of a construction project team. This research applies to the motivation and environmental factors influencing project teams in the achievement of optimum performance; and in doing so, to enhance the performance of project-role players; while adding disciplinespecific theory. This study has employed in-depth interview data, which were thematically analysed. The interviews were conducted in a case-study design comprising four projects in South Africa. The study concluded by emphasising the importance of how role-players RELATE to each other, and LOVE project challenges. It further noted that PMs who are MANAGING LEADERS would be most influential in the project environment; while PROCUREMENT greatly influences the project environment. Relational issues are important to role-players; and they act as MOTIVATORS, with certain issues in a project presenting both performance BARRIERS and DRIVER capabilities. Finally, project MOMENTUM changes constantly, with the current momentum direction influencing the future course thereof. In meeting the aims of the research, a Performance Optimisation Framework was developed, noting how the emergent themes co-exist in optimal performance environments. The study also developed the Project Husbandry approach, reflecting on a caring, nurturing, diligent and mature approach when managing role-players. The study recommends that the themes impacting the project-operating environment should be influenced by management and leadership, in order to optimise the performance of all the role-players involved.
- Full Text:
- Date Issued: 2019
- Authors: Hefer, Andre Le Roux
- Date: 2019
- Subjects: Construction industry -- Management , Project management Performance
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/40316 , vital:36140
- Description: Authors predict major changes in the requirements to manage complex environments in the 21st century. These 21st century challenges, for Project Managers (PM) in the construction industry, are evident through the ongoing perception that the industry performance record is suboptimal. In the pursuit of performance optimisation, management disciplines developed and implemented theories and models not only to achieve what is required, but also to excel and create high-performing teams. In search of project success, researchers have also identified quantifiable variables, models, success factors and other related issues. The PM’s role in the attainment of success has also been widely researched, especially the impact, influence, methods and tools related to the discipline. Nevertheless, the general concern remains, that the performance of the industry is suboptimal. This study therefore aimed to qualitatively evaluate and examine the various factors and influences on performance of a construction project team. This research applies to the motivation and environmental factors influencing project teams in the achievement of optimum performance; and in doing so, to enhance the performance of project-role players; while adding disciplinespecific theory. This study has employed in-depth interview data, which were thematically analysed. The interviews were conducted in a case-study design comprising four projects in South Africa. The study concluded by emphasising the importance of how role-players RELATE to each other, and LOVE project challenges. It further noted that PMs who are MANAGING LEADERS would be most influential in the project environment; while PROCUREMENT greatly influences the project environment. Relational issues are important to role-players; and they act as MOTIVATORS, with certain issues in a project presenting both performance BARRIERS and DRIVER capabilities. Finally, project MOMENTUM changes constantly, with the current momentum direction influencing the future course thereof. In meeting the aims of the research, a Performance Optimisation Framework was developed, noting how the emergent themes co-exist in optimal performance environments. The study also developed the Project Husbandry approach, reflecting on a caring, nurturing, diligent and mature approach when managing role-players. The study recommends that the themes impacting the project-operating environment should be influenced by management and leadership, in order to optimise the performance of all the role-players involved.
- Full Text:
- Date Issued: 2019
Oral narratives as intertexts in selected Nigerian films
- Authors: Usman, Joshua
- Date: 2019
- Subjects: Folk literature -- Nigeria , Oral tradition -- Nigeria Motion pictures -- Nigeria
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/43721 , vital:37038
- Description: This research into the interface between orality and Nigerian film builds on previous scholarly works in the field (Ladebo (1992), Onabajo and M’Bayo (2009), Omolola (2013), Ezeigbo (2013), Mgbemere (2015) and Onzuike (2016)). Evident from these studies is the prevalence of recurring patterns of oral narratives in Nigerian film. The aim of this study is to consider the following research questions: Do film producers/directors adopt the use of oral narratives in Nigerian film texts? How do oral narratives translate into films? What is the rate of recurrence of oral narratives in Nigerian films? Do oral narratives aesthetically influence the quality of Nigerian films? For the purpose of this study a selection of nine Nigerian films (three each from the Yoruba, Hausa and Igbo groups). These films are analysed as primary texts to show the occurrence of elements of orature and oral narratives. Underpinning such analysis is the theory of intertextuality as coined by the French linguist Julia Kristeva. Kristeva sees the text as “intertextuality […] within the text of society and history” (Kristeva, 1980: 37). This approach is augmented by the views of Greenblatt on New Historicism, which implies literature should be studied and interpreted within the context of the history of the author and cultural/social context. The nine films under discussion are considered within their cultural/social context.
- Full Text:
- Date Issued: 2019
- Authors: Usman, Joshua
- Date: 2019
- Subjects: Folk literature -- Nigeria , Oral tradition -- Nigeria Motion pictures -- Nigeria
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/43721 , vital:37038
- Description: This research into the interface between orality and Nigerian film builds on previous scholarly works in the field (Ladebo (1992), Onabajo and M’Bayo (2009), Omolola (2013), Ezeigbo (2013), Mgbemere (2015) and Onzuike (2016)). Evident from these studies is the prevalence of recurring patterns of oral narratives in Nigerian film. The aim of this study is to consider the following research questions: Do film producers/directors adopt the use of oral narratives in Nigerian film texts? How do oral narratives translate into films? What is the rate of recurrence of oral narratives in Nigerian films? Do oral narratives aesthetically influence the quality of Nigerian films? For the purpose of this study a selection of nine Nigerian films (three each from the Yoruba, Hausa and Igbo groups). These films are analysed as primary texts to show the occurrence of elements of orature and oral narratives. Underpinning such analysis is the theory of intertextuality as coined by the French linguist Julia Kristeva. Kristeva sees the text as “intertextuality […] within the text of society and history” (Kristeva, 1980: 37). This approach is augmented by the views of Greenblatt on New Historicism, which implies literature should be studied and interpreted within the context of the history of the author and cultural/social context. The nine films under discussion are considered within their cultural/social context.
- Full Text:
- Date Issued: 2019
Political education as a determinant of university students’ political participation in the Eastern Cape, South Africa
- Authors: Badaru, Kazeem Ajasa
- Date: 2019
- Subjects: Citizenship -- Study and teaching -- South Africa Democracy and education -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/15793 , vital:40524
- Description: Globally, there is a downward trend in youths’ political interest and participation in the learning of political education in their school curricula as a measure to combat the apparent dangers posed by the declining young citizens’ participation in the political processes.This study therefore investigated political education as a determinant of university students’ political participation in the Province of the Eastern Cape, South Africa. The study employed a mixed methods design. Using the probability sampling technique, a sample of 375 participants was randomly selected from one university in the Eastern Cape Province while semi-structured interviews were conducted among five (5) purposively selected members of the same university’s Student Representative Council (SRC) executive committee. Simple descriptive statistics such as frequency counts and percentages were used to summarize all categories of variables; while Pearson correlation statistics, Chi-square and Ordinary least square regression were used to examine the relationship between dependent and independent variables at a 95percent confidence interval. Alpha values less than 0.05 were considered to be statistically significant. Thematic content analysis was performed on the qualitative data. The quantitative analysis revealed that students’ level of political awareness was high; 98.1percent of them were aware of their rights to vote and be voted for. Students’ political judgment was positively correlated with participation in campus (r =0.182) and national politics (r = 0.030) respectively. Most of the students agreed to take part in the 2018 SRC (78.8percent) and 2019 national elections (77.9percent) respectively. Political interest was significantly correlated with participation in campus (r = 0.375) and national politics (r =0. 404). The findings from the multivariate analysis showed that political interest (<0.001), parents’ political involvement (<0.001) and year of study (<0.001) were the significant determinants of students’ participation in politics. The qualitative findings also showed that there was a positive relationship between political education and students’ participation in politics. Since political interest and family are element and agent of political education respectively, it is concluded that political education is to a large extent a determinant of university students’ political participation. It is recommended that the universities, the Department of Higher Education and Training (DHET) and other stakeholders should do a thorough review of the university education curricula and programmes to ensure that political education is adequately accommodated and taken care of in a way that would increase students’ interest, awareness and participation in politics. When this is amply done, students’ cognitive skills and capacities would be enhanced to increase their participation in the political processes in South Africa.
- Full Text:
- Date Issued: 2019
- Authors: Badaru, Kazeem Ajasa
- Date: 2019
- Subjects: Citizenship -- Study and teaching -- South Africa Democracy and education -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/15793 , vital:40524
- Description: Globally, there is a downward trend in youths’ political interest and participation in the learning of political education in their school curricula as a measure to combat the apparent dangers posed by the declining young citizens’ participation in the political processes.This study therefore investigated political education as a determinant of university students’ political participation in the Province of the Eastern Cape, South Africa. The study employed a mixed methods design. Using the probability sampling technique, a sample of 375 participants was randomly selected from one university in the Eastern Cape Province while semi-structured interviews were conducted among five (5) purposively selected members of the same university’s Student Representative Council (SRC) executive committee. Simple descriptive statistics such as frequency counts and percentages were used to summarize all categories of variables; while Pearson correlation statistics, Chi-square and Ordinary least square regression were used to examine the relationship between dependent and independent variables at a 95percent confidence interval. Alpha values less than 0.05 were considered to be statistically significant. Thematic content analysis was performed on the qualitative data. The quantitative analysis revealed that students’ level of political awareness was high; 98.1percent of them were aware of their rights to vote and be voted for. Students’ political judgment was positively correlated with participation in campus (r =0.182) and national politics (r = 0.030) respectively. Most of the students agreed to take part in the 2018 SRC (78.8percent) and 2019 national elections (77.9percent) respectively. Political interest was significantly correlated with participation in campus (r = 0.375) and national politics (r =0. 404). The findings from the multivariate analysis showed that political interest (<0.001), parents’ political involvement (<0.001) and year of study (<0.001) were the significant determinants of students’ participation in politics. The qualitative findings also showed that there was a positive relationship between political education and students’ participation in politics. Since political interest and family are element and agent of political education respectively, it is concluded that political education is to a large extent a determinant of university students’ political participation. It is recommended that the universities, the Department of Higher Education and Training (DHET) and other stakeholders should do a thorough review of the university education curricula and programmes to ensure that political education is adequately accommodated and taken care of in a way that would increase students’ interest, awareness and participation in politics. When this is amply done, students’ cognitive skills and capacities would be enhanced to increase their participation in the political processes in South Africa.
- Full Text:
- Date Issued: 2019
Pre-service education students’ application of visualisation strategies to solve mathematical word-problems
- Authors: Shaw, Peter
- Date: 2019
- Subjects: Word problems (Mathematics)
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/16604 , vital:40735
- Description: This classroom-based action research dissertation examined visualisation strategies used by pre-service Intermediate Phase PGCE education students to solve mathematical word-problems. The setting was an Eastern Cape university. Previous literature indicated a positive correlation between the use of visual scaffolds and success in solving word problems. However, a gap was found insofar as little research had been published on the application of visualisation to word-problems by student teachers in South Africa. This thesis advances our understanding of the role visualisation may play in assisting student teachers to solve word-problems. The theoretic framework was informed by Bruner’s theory of learning. The research was grounded in the hermeneutic tradition. An interpretivist research paradigm was expedited by using an inductive, naturalistic perspective and relativist ontology. Thirty-eight student-teachers participated in the study. Parallel and convergent qualitative and quantitative data gathering instruments were used, thereby facilitating triangulation and examination for microgenesis. It was found that vestiges of past teaching practices initially limited the participants’ knowledge to a deeply-flawed, banking model of routines and an instrumental perception of mathematics. Disruptive calls for social justice impeded progress. Albeit visualisation strategies liberated understanding, many foundational concepts and skills had to be reconstructed. The confluence of time and rehearsal culminated in some measure of expertise. Sustained effort enabled new knowledge to be compressed and consigned to long-term memory. Salient visual representations assisted participants to conceptualise relational mathematical meta-concepts and reduced the cognitive demands imposed by word-problems but that achievement was a hard-won prize.
- Full Text:
- Date Issued: 2019
- Authors: Shaw, Peter
- Date: 2019
- Subjects: Word problems (Mathematics)
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/16604 , vital:40735
- Description: This classroom-based action research dissertation examined visualisation strategies used by pre-service Intermediate Phase PGCE education students to solve mathematical word-problems. The setting was an Eastern Cape university. Previous literature indicated a positive correlation between the use of visual scaffolds and success in solving word problems. However, a gap was found insofar as little research had been published on the application of visualisation to word-problems by student teachers in South Africa. This thesis advances our understanding of the role visualisation may play in assisting student teachers to solve word-problems. The theoretic framework was informed by Bruner’s theory of learning. The research was grounded in the hermeneutic tradition. An interpretivist research paradigm was expedited by using an inductive, naturalistic perspective and relativist ontology. Thirty-eight student-teachers participated in the study. Parallel and convergent qualitative and quantitative data gathering instruments were used, thereby facilitating triangulation and examination for microgenesis. It was found that vestiges of past teaching practices initially limited the participants’ knowledge to a deeply-flawed, banking model of routines and an instrumental perception of mathematics. Disruptive calls for social justice impeded progress. Albeit visualisation strategies liberated understanding, many foundational concepts and skills had to be reconstructed. The confluence of time and rehearsal culminated in some measure of expertise. Sustained effort enabled new knowledge to be compressed and consigned to long-term memory. Salient visual representations assisted participants to conceptualise relational mathematical meta-concepts and reduced the cognitive demands imposed by word-problems but that achievement was a hard-won prize.
- Full Text:
- Date Issued: 2019
Selected stakeholders’ views on the use of tablet computers in learning and teaching – a South African case study at a university
- Fernandez, Simon Christopher
- Authors: Fernandez, Simon Christopher
- Date: 2019
- Subjects: Computer-assisted instruction Tablet computers Educational technology
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/15903 , vital:40553
- Description: The popularity of mobile technologies has greatly influenced the people of all ages, especially adolescents. Tablet computers as part of mobile technologies, were launched in colleges and universities in many countries to supplement and complement learning and teaching. However, research reports based on the effectiveness of the use of tablet computers in higher education institutions in South Africa’s Eastern Cape Province are scarce. In order to address the deficiency, this study examined the views of stakeholders such as students, lecturers and managers on the use of tablet computers for learning and teaching in one of the Eastern Cape universities. The research adopted the Post-Positivist paradigm and mixed method approach. The theoretical frameworks were Constructivism and Technological Pedagogical Content Knowledge. The sample consisted of (a) 155 students from a population of 254 extended-stream National Diploma students in Information and Communication Technology and National Diploma Electrical Engineering cohorts; (b) 14 lecturers from a relevant population of 25; and, (c) 16 managers from a population of 20. Three separate questionnaires as well as interview protocols for each of the stakeholder cohorts provided the core data. All members in the sample were surveyed. The researcher opted to be an outsider and received assistance from a few qualified trained academics to administer the questionnaire to students in different cohorts in order to minimise data bias. Only 18 students, five lecturers and nine managers were interviewed. Quantitative data were captured manually into Statistical Package for Social Sciences (version 24) and they were analysed using descriptive and inferential analysis: Analysis of Variance and Independent Samples t-test. Qualitative data were transcribed and analysed using thematic analysis to generate major themes and sub themes for the sub-research questions. Main strengths of using tablets from the findings of the study were (a) tablets motivated students in learning and lecturers in teaching (b) students understood the different styles of learning (c) enhanced students’ engagement and collaboration in learning. Main weakness of using tablets were students’ use of tablets for personal work and social networking during class hours was causing distractions to lecturers and other students. Generally, the evidence shows that strengths were greater than the weaknesses. It should also be noted that all stakeholders were positive and not statistically significantly different from each other in their views towards the use of tablets for learning and teaching in university classroom. However, students had views different from lecturers on the advantages and disadvantages of using tablets. The variance could be due to new students or new lecturers’ ignorance in the effective use of tablets and this might change as their familiarity in the use of the device improves. The research report makes a few recommendations which include training to all students and lecturers on the effective use of tablet computers for learning and teaching and installation of relevant applications before the commencement of each academic year. Moreover, the Information and communication technology technical staff must prevent students from visiting unwanted and restricted sites by keeping a network based tracker and blocker software application.
- Full Text:
- Date Issued: 2019
- Authors: Fernandez, Simon Christopher
- Date: 2019
- Subjects: Computer-assisted instruction Tablet computers Educational technology
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/15903 , vital:40553
- Description: The popularity of mobile technologies has greatly influenced the people of all ages, especially adolescents. Tablet computers as part of mobile technologies, were launched in colleges and universities in many countries to supplement and complement learning and teaching. However, research reports based on the effectiveness of the use of tablet computers in higher education institutions in South Africa’s Eastern Cape Province are scarce. In order to address the deficiency, this study examined the views of stakeholders such as students, lecturers and managers on the use of tablet computers for learning and teaching in one of the Eastern Cape universities. The research adopted the Post-Positivist paradigm and mixed method approach. The theoretical frameworks were Constructivism and Technological Pedagogical Content Knowledge. The sample consisted of (a) 155 students from a population of 254 extended-stream National Diploma students in Information and Communication Technology and National Diploma Electrical Engineering cohorts; (b) 14 lecturers from a relevant population of 25; and, (c) 16 managers from a population of 20. Three separate questionnaires as well as interview protocols for each of the stakeholder cohorts provided the core data. All members in the sample were surveyed. The researcher opted to be an outsider and received assistance from a few qualified trained academics to administer the questionnaire to students in different cohorts in order to minimise data bias. Only 18 students, five lecturers and nine managers were interviewed. Quantitative data were captured manually into Statistical Package for Social Sciences (version 24) and they were analysed using descriptive and inferential analysis: Analysis of Variance and Independent Samples t-test. Qualitative data were transcribed and analysed using thematic analysis to generate major themes and sub themes for the sub-research questions. Main strengths of using tablets from the findings of the study were (a) tablets motivated students in learning and lecturers in teaching (b) students understood the different styles of learning (c) enhanced students’ engagement and collaboration in learning. Main weakness of using tablets were students’ use of tablets for personal work and social networking during class hours was causing distractions to lecturers and other students. Generally, the evidence shows that strengths were greater than the weaknesses. It should also be noted that all stakeholders were positive and not statistically significantly different from each other in their views towards the use of tablets for learning and teaching in university classroom. However, students had views different from lecturers on the advantages and disadvantages of using tablets. The variance could be due to new students or new lecturers’ ignorance in the effective use of tablets and this might change as their familiarity in the use of the device improves. The research report makes a few recommendations which include training to all students and lecturers on the effective use of tablet computers for learning and teaching and installation of relevant applications before the commencement of each academic year. Moreover, the Information and communication technology technical staff must prevent students from visiting unwanted and restricted sites by keeping a network based tracker and blocker software application.
- Full Text:
- Date Issued: 2019
Study habits and learning styles as correlates of grade 11 students’ academic performance in mathematical literacy in the Amathole Education District
- Authors: Yako, Mzwandile John-Mott
- Date: 2019
- Subjects: Academic performance
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/16687 , vital:40743
- Description: This study investigated whether there was correlation in study habits and learning styles with Mathematical Literacy among the Grade 11 (eleven) high school learners. The Amatole Education District was chosen for this study since it is composed of urban and rural schools. Since Mathematical Literacy was introduced in the system of education in South Africa with the understanding that learners who are finding it a challenge to study Mathematics be complemented with Mathematical Literacy to provide them with skills that are a prerequisite for tertiary level and participation in the economic development. The study purposed to establish whether there was a relationship between academic performance with study habits and learning styles in Mathematical Literacy. The study used the post-positivistic paradigm; the approach was quantitative and the design was descriptive correlational. In sampling probability, cluster sampling was used based on the number of high schools in the Amatole Education District of the Eastern Cape. It was then followed by sub-sampling of learners in Grade 11 (eleven) whose mathematical Literacy skills and performance were being investigated in this study. The theory of Covey on study habits and Kolb’s theory on learning styles were used as a theoretical framework for the study. The data collection instrument used was a closed-ended questionnaire based on a Likert scale measurement. Confidentiality and anonymity were emphasized with informed consent in place. Data was analyzed using SPSS software and Microsoft Excel. The results showed a significant relationship between note taking, writing skills and Mathematical Literacy skills and performance. The findings on the learning styles indicated no significant relationship between socio-demographic factors (visual language, visual numerical, auditory-numerical e.tc.) and academic performance in Mathematical Literacy. This research revealed that study habits had an impact on the academic performance of learners in mathematical literacy. This relationship between academic performance and study habits is an indication that learners needed to improve in their use of English as a second language, especially on note taking, writing skills and Mathematical Literacy.
- Full Text:
- Date Issued: 2019
- Authors: Yako, Mzwandile John-Mott
- Date: 2019
- Subjects: Academic performance
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/16687 , vital:40743
- Description: This study investigated whether there was correlation in study habits and learning styles with Mathematical Literacy among the Grade 11 (eleven) high school learners. The Amatole Education District was chosen for this study since it is composed of urban and rural schools. Since Mathematical Literacy was introduced in the system of education in South Africa with the understanding that learners who are finding it a challenge to study Mathematics be complemented with Mathematical Literacy to provide them with skills that are a prerequisite for tertiary level and participation in the economic development. The study purposed to establish whether there was a relationship between academic performance with study habits and learning styles in Mathematical Literacy. The study used the post-positivistic paradigm; the approach was quantitative and the design was descriptive correlational. In sampling probability, cluster sampling was used based on the number of high schools in the Amatole Education District of the Eastern Cape. It was then followed by sub-sampling of learners in Grade 11 (eleven) whose mathematical Literacy skills and performance were being investigated in this study. The theory of Covey on study habits and Kolb’s theory on learning styles were used as a theoretical framework for the study. The data collection instrument used was a closed-ended questionnaire based on a Likert scale measurement. Confidentiality and anonymity were emphasized with informed consent in place. Data was analyzed using SPSS software and Microsoft Excel. The results showed a significant relationship between note taking, writing skills and Mathematical Literacy skills and performance. The findings on the learning styles indicated no significant relationship between socio-demographic factors (visual language, visual numerical, auditory-numerical e.tc.) and academic performance in Mathematical Literacy. This research revealed that study habits had an impact on the academic performance of learners in mathematical literacy. This relationship between academic performance and study habits is an indication that learners needed to improve in their use of English as a second language, especially on note taking, writing skills and Mathematical Literacy.
- Full Text:
- Date Issued: 2019
Sustainable rural development through community participation: modeling community-based tourism in Nqileni village, Eastern Cape, South Africa
- Authors: Setokoe, Tshepiso Jonathan
- Date: 2019
- Subjects: Rural development -- South Africa -- Eastern Cape , Tourism -- South Africa Tourism -- South Africa -- Eastern Cape Ecotourism
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/43379 , vital:36863
- Description: The development of tourism has been heralded to be a mechanism for sustainable rural development. Sustainable development of any nature requires that any efforts aimed at developing rural areas must involve the community in which the development is undertaken. This has given rise to concerted efforts by governments and development practitioners to involve local communities in development initiatives undertaken within their locale. The study analysed the importance of community participation in tourism development, with the aim to ensure the sustainable rural development of areas such as Nqileni village. This was undertaken using a qualitative research approach using semi-structured interviews to solicit data from twenty members of the Nqileni village community. The data was analysed with the assistance of a specialist qualitative data analyst, using the NVivo sytem, version 11, and was objectively interpreted and analysed by the researcher. The results revealed that the community viewed their participation to be paramount in development initiatives undertaken within the area, which also allows for the building of capacity, and ultimately empowers the community to meaningfully participate in the sustainable development of the area. Finally, the study proposed a community-based tourism model for sustainable rural development, which placed community participations at the root of sustainable development. This has been presented in a form that proposes that a leadership that works together in harmony, coupled with a flow of tourists and investment in the area, which can encourage the community to participate in tourism, resulting in a tourism economy that will allow for positive impacts (such as employment, conservation of resources and preservation of culture).This will enable the reduction of poverty, revival of other economic sectors within the area and foster social cohesion, and ultimately developing the area and its people.
- Full Text:
- Date Issued: 2019
- Authors: Setokoe, Tshepiso Jonathan
- Date: 2019
- Subjects: Rural development -- South Africa -- Eastern Cape , Tourism -- South Africa Tourism -- South Africa -- Eastern Cape Ecotourism
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/43379 , vital:36863
- Description: The development of tourism has been heralded to be a mechanism for sustainable rural development. Sustainable development of any nature requires that any efforts aimed at developing rural areas must involve the community in which the development is undertaken. This has given rise to concerted efforts by governments and development practitioners to involve local communities in development initiatives undertaken within their locale. The study analysed the importance of community participation in tourism development, with the aim to ensure the sustainable rural development of areas such as Nqileni village. This was undertaken using a qualitative research approach using semi-structured interviews to solicit data from twenty members of the Nqileni village community. The data was analysed with the assistance of a specialist qualitative data analyst, using the NVivo sytem, version 11, and was objectively interpreted and analysed by the researcher. The results revealed that the community viewed their participation to be paramount in development initiatives undertaken within the area, which also allows for the building of capacity, and ultimately empowers the community to meaningfully participate in the sustainable development of the area. Finally, the study proposed a community-based tourism model for sustainable rural development, which placed community participations at the root of sustainable development. This has been presented in a form that proposes that a leadership that works together in harmony, coupled with a flow of tourists and investment in the area, which can encourage the community to participate in tourism, resulting in a tourism economy that will allow for positive impacts (such as employment, conservation of resources and preservation of culture).This will enable the reduction of poverty, revival of other economic sectors within the area and foster social cohesion, and ultimately developing the area and its people.
- Full Text:
- Date Issued: 2019
The anti-proliferative activity of drimia altissima and a novel isolated flavonoid glycoside against hela cervical cancer cells
- Authors: Nyambe, Mutenta Nsokolo
- Date: 2019
- Subjects: Cancer -- Research , Cervix uteri -- Cancer , Cervix uteri -- Cancer -- Diagnosis -- Developing countries
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/42770 , vital:36690
- Description: Cancer is one of the leading causes of mortality worldwide. About 44% of all cancer morbidity and 53% of all cancer mortality occur in countries with a low to medium Human Development Index (HDI). Thus, cancer is rapidly emerging as a serious threat to public health in Africa and most especially, sub-Saharan Africa. The International Agency for Research on Cancer (IARC) projects that there will be 1.28 million new cancer cases and 970 000 cancer deaths in Africa by the year 2030 owing to the increase in economic development associated lifestyles. The dominant types of cancer in Africa are those related to infectious diseases such as Kaposi’s sarcoma and cervical, hepatic and urinary bladder carcinomas. The main challenge to cancer treatment in Africa is the unavailability of efficacious anticancer drugs. This is because most developing countries can only afford to procure the most basic anticancer drugs, which are also frequently unavailable due to intermittent supplies. This results in patients progressing to more advanced cancer states. One way of combating this African problem is to focus on research that aims at discovering efficacious and cost effective cancer therapies from available natural resources within the African continent. This study investigated the potential anti-proliferative activity (against HeLa cervical cancer cells) of four plants (Adansonia digitata, Ceiba pentandra, Maytenus senegalensis and Drimia altissima) commonly used in the African traditional treatment of malignancies. After in vitro bio-assay screening using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, M. senegalensis root extract (MS-R) and D. altissima bulb extract (DA-B) showed anti-proliferative activity against HeLa cervical cancer cells with IC50 values of 25 μg/mL and 1.1 μg/mL respectively. By possessing the strongest anti-proliferative activity among the tested extracts, D. altissima was selected for further studies. Liquid-liquid partitioning of the Drimia altissima bulb extract with n-hexane, ethyl acetate, and n-butanol, yielded partitions 79a – d, with the n-butanol fraction, 79d, exhibiting the strongest cytotoxic activity (IC50 = 0.497 μg/mL). Through High Content Analysis (HCA) screening, fraction 79d was found to induce marked early mitotic cell cycle arrest. Fractionation of 79d using Diaion® HP-20 open column chromatography and a stepwise gradient of reducing polarity (water-methanol-ethanol-ethyl acetate) yielded cytotoxic fractions 82b, 82c, 82d and 82e, all with significant anti-proliferative activities at the tested concentrations of 0.1, 1.0 and 10 μg/mL. Bio-assay guided fractionation of 82c (the most effective fraction at the lowest tested concentration of 0.1 μg/mL) using Sephadex® LH-20 open column chromatography and 50% MeOH led to the isolation of compound 3.17. After structural elucidation using 1D and 2D Nuclear Magnetic Resonance spectroscopy (NMR), High resolution Mass spectrometry (HRMS), Fourier-Transform Infrared spectroscopy (FT-IR), ultraviolet spectroscopy (UV) and Circular Dichroism (CD), compound 3.17 was identified as a novel C-glucosylflavonoid-O-glucoside, 6-C-[-apio-α-D-furanosyl-(1→6)-β-glucopyranosyl]-4′, 5, 7-trihydroxyflavone (Altissimin, 3.17). Compound 3.17 exhibited a dose dependant anti-proliferative activity with an IC50 of 2.44 μM. The mechanism of action for compound 3.17 was investigated through cell cycle arrest, phosphatidylserine translocation (PS), caspase activation and mitochondrial membrane depolarization. The mechanism of cell death elicited by compound 3.17 in HeLa cells was found to involve the induction of M phase cell cycle arrest with consequent activation of apoptotic cell death which was evident from annexin V staining, mitochondrial membrane potential (ΔΨm) collapse and the activation of caspases -8 and -3. In silico computational techniques were employed to virtually determine potential biological targets of compound 3.17. Target fishing using the Similarity Ensemble Approach (SEA) target prediction gave human aldose reductase (hAR, AKR1B1) the highest ranking with a p value of 2.85 x 10-24, a max Tc of 0.35 and a Z-score of 41.8217. Using AutoDock4 and the AutoDock tools suite (ADT), molecular docking of compound 3.17 in the hAR binding pocket was successfully achieved with a lower ΔG free energy binding (-9.4 kcal/mol) than that of positive control ligand 393 (-8.7 kcal/mol). In conclusion, this study identified the genus Drimia and particularly D. altissima as a potential source for novel cytotoxic compounds. The discovery of altissimin (3.17), the first flavonoid glycoside to be isolate from D. altissima, enquires into the possible existence of similar compounds within the species. In addition to the observed in vitro cytotoxic activity against HeLa cells, the potential of altissimin (3.17) as a hAR enzyme inhibitor opens up the possibility of its use as an adjunct to increase cancer cell sensitivity to chemotherapy. Thus, altissimin (3.17) shows promise as a potential anticancer agent.
- Full Text:
- Date Issued: 2019
- Authors: Nyambe, Mutenta Nsokolo
- Date: 2019
- Subjects: Cancer -- Research , Cervix uteri -- Cancer , Cervix uteri -- Cancer -- Diagnosis -- Developing countries
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/42770 , vital:36690
- Description: Cancer is one of the leading causes of mortality worldwide. About 44% of all cancer morbidity and 53% of all cancer mortality occur in countries with a low to medium Human Development Index (HDI). Thus, cancer is rapidly emerging as a serious threat to public health in Africa and most especially, sub-Saharan Africa. The International Agency for Research on Cancer (IARC) projects that there will be 1.28 million new cancer cases and 970 000 cancer deaths in Africa by the year 2030 owing to the increase in economic development associated lifestyles. The dominant types of cancer in Africa are those related to infectious diseases such as Kaposi’s sarcoma and cervical, hepatic and urinary bladder carcinomas. The main challenge to cancer treatment in Africa is the unavailability of efficacious anticancer drugs. This is because most developing countries can only afford to procure the most basic anticancer drugs, which are also frequently unavailable due to intermittent supplies. This results in patients progressing to more advanced cancer states. One way of combating this African problem is to focus on research that aims at discovering efficacious and cost effective cancer therapies from available natural resources within the African continent. This study investigated the potential anti-proliferative activity (against HeLa cervical cancer cells) of four plants (Adansonia digitata, Ceiba pentandra, Maytenus senegalensis and Drimia altissima) commonly used in the African traditional treatment of malignancies. After in vitro bio-assay screening using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, M. senegalensis root extract (MS-R) and D. altissima bulb extract (DA-B) showed anti-proliferative activity against HeLa cervical cancer cells with IC50 values of 25 μg/mL and 1.1 μg/mL respectively. By possessing the strongest anti-proliferative activity among the tested extracts, D. altissima was selected for further studies. Liquid-liquid partitioning of the Drimia altissima bulb extract with n-hexane, ethyl acetate, and n-butanol, yielded partitions 79a – d, with the n-butanol fraction, 79d, exhibiting the strongest cytotoxic activity (IC50 = 0.497 μg/mL). Through High Content Analysis (HCA) screening, fraction 79d was found to induce marked early mitotic cell cycle arrest. Fractionation of 79d using Diaion® HP-20 open column chromatography and a stepwise gradient of reducing polarity (water-methanol-ethanol-ethyl acetate) yielded cytotoxic fractions 82b, 82c, 82d and 82e, all with significant anti-proliferative activities at the tested concentrations of 0.1, 1.0 and 10 μg/mL. Bio-assay guided fractionation of 82c (the most effective fraction at the lowest tested concentration of 0.1 μg/mL) using Sephadex® LH-20 open column chromatography and 50% MeOH led to the isolation of compound 3.17. After structural elucidation using 1D and 2D Nuclear Magnetic Resonance spectroscopy (NMR), High resolution Mass spectrometry (HRMS), Fourier-Transform Infrared spectroscopy (FT-IR), ultraviolet spectroscopy (UV) and Circular Dichroism (CD), compound 3.17 was identified as a novel C-glucosylflavonoid-O-glucoside, 6-C-[-apio-α-D-furanosyl-(1→6)-β-glucopyranosyl]-4′, 5, 7-trihydroxyflavone (Altissimin, 3.17). Compound 3.17 exhibited a dose dependant anti-proliferative activity with an IC50 of 2.44 μM. The mechanism of action for compound 3.17 was investigated through cell cycle arrest, phosphatidylserine translocation (PS), caspase activation and mitochondrial membrane depolarization. The mechanism of cell death elicited by compound 3.17 in HeLa cells was found to involve the induction of M phase cell cycle arrest with consequent activation of apoptotic cell death which was evident from annexin V staining, mitochondrial membrane potential (ΔΨm) collapse and the activation of caspases -8 and -3. In silico computational techniques were employed to virtually determine potential biological targets of compound 3.17. Target fishing using the Similarity Ensemble Approach (SEA) target prediction gave human aldose reductase (hAR, AKR1B1) the highest ranking with a p value of 2.85 x 10-24, a max Tc of 0.35 and a Z-score of 41.8217. Using AutoDock4 and the AutoDock tools suite (ADT), molecular docking of compound 3.17 in the hAR binding pocket was successfully achieved with a lower ΔG free energy binding (-9.4 kcal/mol) than that of positive control ligand 393 (-8.7 kcal/mol). In conclusion, this study identified the genus Drimia and particularly D. altissima as a potential source for novel cytotoxic compounds. The discovery of altissimin (3.17), the first flavonoid glycoside to be isolate from D. altissima, enquires into the possible existence of similar compounds within the species. In addition to the observed in vitro cytotoxic activity against HeLa cells, the potential of altissimin (3.17) as a hAR enzyme inhibitor opens up the possibility of its use as an adjunct to increase cancer cell sensitivity to chemotherapy. Thus, altissimin (3.17) shows promise as a potential anticancer agent.
- Full Text:
- Date Issued: 2019
The future of banking in South Africa towards 2055: disruptive innovation scenarios
- Authors: Koekemoer, Jonathan
- Date: 2019
- Subjects: Finance -- South Africa , Economic development -- South Africa , Banks and banking -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/40577 , vital:36184
- Description: The research effort developed four possible scenarios for the future of banking in South Africa towards 2055. The scenarios sought to stimulate thought on the possible, probable, plausible and preferred effects of disruptive innovation and regulation in the South African banking sector. The scenarios were developed in strict accordance with the 5 stages, and 9 steps, of the scenario-based planning process of futures studies. A conceptual futures studies model for banking in South Africa was developed to guide and clarify the way in which the research on South African banking can be integrated into the body of existing futures studies theory. The research study began with a comprehensive environmental scan, where various megatrends and driving forces are identified. A PESTEL analysis provided a deeper understanding of the driving forces. A Real-Time Delphi study was conducted in order to validate and prioritise the megatrends and driving forces that emerged. As a result, the research study was able to present four plausible scenarios that provide a better understanding of the future of banking in South Africa over the decades to come. The research presents banking as a complex, multi-faceted sector that is heavily influenced by advances in technology. The Real-Time Delphi research allowed the aggregation of expert knowledge. This is used as a guide to assist decision-makers and industry leaders in the adoption of appropriate business models and strategies towards a preferred future state. The research defined the Integrated Vision as the preferred future state for the South African banking sector towards 2055. The study closes a research gap where current strategies deviate from proposed strategies that drive the achievement of the Integrated Vision by 2055. Finally, contextually aligned practical recommendations are provided to assist decision-makers, industry leaders and change agents to work towards a preferable future state. The proposed recommendations are placed into broad categories of innovation, financial inclusion and collaborative regulatory relationships. The research makes a meaningful contribution to the South African banking sector by introducing a forward-looking, systems-thinking approach to disruptive innovation and regulation in the South African context.
- Full Text:
- Date Issued: 2019
- Authors: Koekemoer, Jonathan
- Date: 2019
- Subjects: Finance -- South Africa , Economic development -- South Africa , Banks and banking -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/40577 , vital:36184
- Description: The research effort developed four possible scenarios for the future of banking in South Africa towards 2055. The scenarios sought to stimulate thought on the possible, probable, plausible and preferred effects of disruptive innovation and regulation in the South African banking sector. The scenarios were developed in strict accordance with the 5 stages, and 9 steps, of the scenario-based planning process of futures studies. A conceptual futures studies model for banking in South Africa was developed to guide and clarify the way in which the research on South African banking can be integrated into the body of existing futures studies theory. The research study began with a comprehensive environmental scan, where various megatrends and driving forces are identified. A PESTEL analysis provided a deeper understanding of the driving forces. A Real-Time Delphi study was conducted in order to validate and prioritise the megatrends and driving forces that emerged. As a result, the research study was able to present four plausible scenarios that provide a better understanding of the future of banking in South Africa over the decades to come. The research presents banking as a complex, multi-faceted sector that is heavily influenced by advances in technology. The Real-Time Delphi research allowed the aggregation of expert knowledge. This is used as a guide to assist decision-makers and industry leaders in the adoption of appropriate business models and strategies towards a preferred future state. The research defined the Integrated Vision as the preferred future state for the South African banking sector towards 2055. The study closes a research gap where current strategies deviate from proposed strategies that drive the achievement of the Integrated Vision by 2055. Finally, contextually aligned practical recommendations are provided to assist decision-makers, industry leaders and change agents to work towards a preferable future state. The proposed recommendations are placed into broad categories of innovation, financial inclusion and collaborative regulatory relationships. The research makes a meaningful contribution to the South African banking sector by introducing a forward-looking, systems-thinking approach to disruptive innovation and regulation in the South African context.
- Full Text:
- Date Issued: 2019
The impact of public spending on economic growth, employment and poverty reduction in South Africa
- Authors: Kavese, Kambale
- Date: 2019
- Subjects: Expenditures, Public -- South Africa , Economic development -- South Africa Labor economics -- South Africa Employment (Economic theory) Poor -- Employment -- South Africa South Africa -- Economic conditions
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/39940 , vital:35570
- Description: This study seeks to assess the effect of public spending on economic growth, employment, and poverty reduction. The co-existence of a sound fiscal policy and a substantial government expenditure but insignificant returns in terms of social development suggests the potential of a dilemma that needs to be investigated, and to reflect on the dynamics of selected marginalised groups of people and marginalised areas. Hence, the “social inclusion” strategy of the RDP in 1994, and the “inclusive economy” strategy of the NDP in 2014 were implemented with one single objective in mind, that is to narrow the gaps associated with the legacy of apartheid. Despite the implantation of government plans like the RDP and recently the NDP, and regardless of the effective use of fiscal policy, low growth has continued during the post-recession era; unemployment and inequality have persistently remained at high levels. This paradox has led to controversies around fiscal policy’s dual role of stimulating economic growth and income redistribution. To achieve the research objective, the study employs four types of empirical techniques: the nonlinear autoregressive distributive lag (N-ARDL) cointegration model; the economy-wide Leontief approach calibrated on the supply and use tables (dynamic SUT model); a partial general equilibrium approach based on the Social Accounting Matrix (SAM model) used for micro-simulations; and lastly a contemporaneous dynamic computable general equilibrium (CGE) model to assess the effect of fiscal policy on macroeconomic and socioeconomic variables. The study found that during the post-recession era, expansionary fiscal policy had a positive but minute effect on growth, employment and poverty reduction. The effect of government spending has had a minimal effect on historically marginalised groups of people and marginalised areas. This is why a tortoise pace in reducing poverty and inequality has persisted. So, the study recommends that governments should follow a priorities-based government spending policy which fits well with the current situation of the country. Moreover, South Africa needs to adopt international standards and best practices of “science-based strategic” rather than that of “evidence-based strategy” and ensure that only programmes that have proved to be effective be financed in the fiscal budget.
- Full Text:
- Date Issued: 2019
- Authors: Kavese, Kambale
- Date: 2019
- Subjects: Expenditures, Public -- South Africa , Economic development -- South Africa Labor economics -- South Africa Employment (Economic theory) Poor -- Employment -- South Africa South Africa -- Economic conditions
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/39940 , vital:35570
- Description: This study seeks to assess the effect of public spending on economic growth, employment, and poverty reduction. The co-existence of a sound fiscal policy and a substantial government expenditure but insignificant returns in terms of social development suggests the potential of a dilemma that needs to be investigated, and to reflect on the dynamics of selected marginalised groups of people and marginalised areas. Hence, the “social inclusion” strategy of the RDP in 1994, and the “inclusive economy” strategy of the NDP in 2014 were implemented with one single objective in mind, that is to narrow the gaps associated with the legacy of apartheid. Despite the implantation of government plans like the RDP and recently the NDP, and regardless of the effective use of fiscal policy, low growth has continued during the post-recession era; unemployment and inequality have persistently remained at high levels. This paradox has led to controversies around fiscal policy’s dual role of stimulating economic growth and income redistribution. To achieve the research objective, the study employs four types of empirical techniques: the nonlinear autoregressive distributive lag (N-ARDL) cointegration model; the economy-wide Leontief approach calibrated on the supply and use tables (dynamic SUT model); a partial general equilibrium approach based on the Social Accounting Matrix (SAM model) used for micro-simulations; and lastly a contemporaneous dynamic computable general equilibrium (CGE) model to assess the effect of fiscal policy on macroeconomic and socioeconomic variables. The study found that during the post-recession era, expansionary fiscal policy had a positive but minute effect on growth, employment and poverty reduction. The effect of government spending has had a minimal effect on historically marginalised groups of people and marginalised areas. This is why a tortoise pace in reducing poverty and inequality has persisted. So, the study recommends that governments should follow a priorities-based government spending policy which fits well with the current situation of the country. Moreover, South Africa needs to adopt international standards and best practices of “science-based strategic” rather than that of “evidence-based strategy” and ensure that only programmes that have proved to be effective be financed in the fiscal budget.
- Full Text:
- Date Issued: 2019
The influence of multinational corporations in promoting foreign direct investment in the South African business environment
- Van der Berg, Jan Gabriel Mara
- Authors: Van der Berg, Jan Gabriel Mara
- Date: 2019
- Subjects: Investments, Foreign -- South Africa , Business enterprises Business Organisations Industrial promotion
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/44213 , vital:37131
- Description: One of the major driving forces behind international trade over the past thirty years has been Foreign Direct Investment (FDI). Due to the importance of FDI, a vast amount of research has been conducted on the various elements that make up FDI. There has also been widespread research done to measure the impact of FDI on host countries, and attempts have been made to determine the long-term benefits thereof. Despite the existent research on FDI, there is a dearth of literature on the unique situation in South Africa (due to the country’s fragmented past) and the impact of FDI on the South African economy. This study attempts to address this research gap and to add to the existent body of knowledge on FDI market entry. Thus, the primary objective of this study was to examine the impact of multinational corporations (MNCs) in promoting the entry of FDIs in South Africa, and the effectiveness of these investments in the South African business environment. The comprehensive literature review in this study included a discussion of the background to the pre- and post-apartheid South African economy, and the various efforts made by the South African government to facilitate sustainable economic growth through various economic policies. FDI was identified as one of the four major indicators of economic growth and was therefore investigated as a concept, strategy and driver of change. The South African marketing environment was analysed in order to assist in the identification of variables that are conducive to FDI. The final section of the literature review utilised three cases to better illustrate and understand the different challenges, market entry strategies and long-term implications of FDI. In this study, the independent variables (international marketing environment, stakeholder intervention, government considerations, resources and FDI incentives) were identified as influencing the mediating variable (FDI market entry strategy) and the dependent variables (competitiveness, sustainability, trade agreements and commitment of traders). These independent variables were selected to construct a hypothesised model and the research hypotheses. To this end, an empirical investigation was conducted, the measuring instrument used in this investigation was a questionnaire, which was assembled with the help of insights gained from secondary sources. The study respondents were selected through convenience sampling. A total of 210 respondents participated in the study, and 165 useable questionnaires were subjected to statistical analysis. The data collected for this study was subjected to five phases of analysis: exploratory factor analysis to assess validity; Cronbach’s alpha was used to test for internal consistency reliability; descriptive statistics to describe the fundamental features of the data by providing a statistical summary and analysis; and the nine hypotheses pertaining to the relationships between different variables were assessed using inferential statistical procedures, Pearson’s product correlation and regression analysis. This led to the adaptation of the hypothesised model and the hypotheses so as to indicate the changes resulting from the EFA. The findings of this study reveals that external stakeholder intervention as well as FDI incentives and resources effectively influence FDI market entry strategy in the South African business environment. The study results further reveal that the promotion of FDI market entry strategy positively influences competitiveness, sustainability, trade agreements and commitment of traders in the South African business environment. For MNCs to be successful in the expansion of FDI market entry strategy in the South African business environment, the study recommends that it is important to consider the availability of potential local partners, proximity to trading routes, reduction of the costs involved in supplying the market, the effect of tariff barriers and a competitive domestic economy. It is further recommended that MNCs need to focus on the utilisation of reliable and effective equipment in order to enable the productive management of operations in the South African business environment. The study also recommends the South African business environment as a strategic investment destination for the promotion of FDI market entry strategy as it offers low production costs in particular trading locations. This study has contributed to the field of FDI and the FDI market entry strategies employed by MNCs in South Africa. The research findings identified the international marketing (SLEPTS) factors through an assessment of the South African marketing environment, as these factors are deemed important for FDI to occur. The study also highlights the critical international marketing factors that could be used to improve local conditions through a mixture of incentives and policy re-alignment, so as to be more conducive to attracting large scale FDI. The hypothesised model developed for this study contributed to identifying the influence of external stakeholders on the successful market entry of FDI into South Africa, a critical element that MNCs usually only identify after market entry is complete. Evidence from the study shows that the South African government should direct FDI incentives towards those sectors in the economy that stand to benefit the most from the spill-over effects of FDI, in order to maximise the impact of FDI on the local economy. The research also indicates that elements such as restrictive legislation and government corruption may, to a certain degree, hinder FDI; therefore, these issues need to be addressed through legislation. It is recommended that all local efforts to attract FDI are industry or sector focussed, and that they are guided by government policies towards the greater benefit of the South African economy. Furthermore, the study found that the relationship between the host country and the MNC is critical to achieving sustainability in the long-term; therefore, it is suggested that the South African government improves its relationship with local businesses and MNCs that are looking to invest in South Africa. To conclude, it was found that South Africa has a very important role to play in attracting global FDI to Africa, as it has an accessible market based on geographic location, trade channels and traditional linkages with African and European networks.
- Full Text:
- Date Issued: 2019
- Authors: Van der Berg, Jan Gabriel Mara
- Date: 2019
- Subjects: Investments, Foreign -- South Africa , Business enterprises Business Organisations Industrial promotion
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/44213 , vital:37131
- Description: One of the major driving forces behind international trade over the past thirty years has been Foreign Direct Investment (FDI). Due to the importance of FDI, a vast amount of research has been conducted on the various elements that make up FDI. There has also been widespread research done to measure the impact of FDI on host countries, and attempts have been made to determine the long-term benefits thereof. Despite the existent research on FDI, there is a dearth of literature on the unique situation in South Africa (due to the country’s fragmented past) and the impact of FDI on the South African economy. This study attempts to address this research gap and to add to the existent body of knowledge on FDI market entry. Thus, the primary objective of this study was to examine the impact of multinational corporations (MNCs) in promoting the entry of FDIs in South Africa, and the effectiveness of these investments in the South African business environment. The comprehensive literature review in this study included a discussion of the background to the pre- and post-apartheid South African economy, and the various efforts made by the South African government to facilitate sustainable economic growth through various economic policies. FDI was identified as one of the four major indicators of economic growth and was therefore investigated as a concept, strategy and driver of change. The South African marketing environment was analysed in order to assist in the identification of variables that are conducive to FDI. The final section of the literature review utilised three cases to better illustrate and understand the different challenges, market entry strategies and long-term implications of FDI. In this study, the independent variables (international marketing environment, stakeholder intervention, government considerations, resources and FDI incentives) were identified as influencing the mediating variable (FDI market entry strategy) and the dependent variables (competitiveness, sustainability, trade agreements and commitment of traders). These independent variables were selected to construct a hypothesised model and the research hypotheses. To this end, an empirical investigation was conducted, the measuring instrument used in this investigation was a questionnaire, which was assembled with the help of insights gained from secondary sources. The study respondents were selected through convenience sampling. A total of 210 respondents participated in the study, and 165 useable questionnaires were subjected to statistical analysis. The data collected for this study was subjected to five phases of analysis: exploratory factor analysis to assess validity; Cronbach’s alpha was used to test for internal consistency reliability; descriptive statistics to describe the fundamental features of the data by providing a statistical summary and analysis; and the nine hypotheses pertaining to the relationships between different variables were assessed using inferential statistical procedures, Pearson’s product correlation and regression analysis. This led to the adaptation of the hypothesised model and the hypotheses so as to indicate the changes resulting from the EFA. The findings of this study reveals that external stakeholder intervention as well as FDI incentives and resources effectively influence FDI market entry strategy in the South African business environment. The study results further reveal that the promotion of FDI market entry strategy positively influences competitiveness, sustainability, trade agreements and commitment of traders in the South African business environment. For MNCs to be successful in the expansion of FDI market entry strategy in the South African business environment, the study recommends that it is important to consider the availability of potential local partners, proximity to trading routes, reduction of the costs involved in supplying the market, the effect of tariff barriers and a competitive domestic economy. It is further recommended that MNCs need to focus on the utilisation of reliable and effective equipment in order to enable the productive management of operations in the South African business environment. The study also recommends the South African business environment as a strategic investment destination for the promotion of FDI market entry strategy as it offers low production costs in particular trading locations. This study has contributed to the field of FDI and the FDI market entry strategies employed by MNCs in South Africa. The research findings identified the international marketing (SLEPTS) factors through an assessment of the South African marketing environment, as these factors are deemed important for FDI to occur. The study also highlights the critical international marketing factors that could be used to improve local conditions through a mixture of incentives and policy re-alignment, so as to be more conducive to attracting large scale FDI. The hypothesised model developed for this study contributed to identifying the influence of external stakeholders on the successful market entry of FDI into South Africa, a critical element that MNCs usually only identify after market entry is complete. Evidence from the study shows that the South African government should direct FDI incentives towards those sectors in the economy that stand to benefit the most from the spill-over effects of FDI, in order to maximise the impact of FDI on the local economy. The research also indicates that elements such as restrictive legislation and government corruption may, to a certain degree, hinder FDI; therefore, these issues need to be addressed through legislation. It is recommended that all local efforts to attract FDI are industry or sector focussed, and that they are guided by government policies towards the greater benefit of the South African economy. Furthermore, the study found that the relationship between the host country and the MNC is critical to achieving sustainability in the long-term; therefore, it is suggested that the South African government improves its relationship with local businesses and MNCs that are looking to invest in South Africa. To conclude, it was found that South Africa has a very important role to play in attracting global FDI to Africa, as it has an accessible market based on geographic location, trade channels and traditional linkages with African and European networks.
- Full Text:
- Date Issued: 2019
The social sustainability of low-cost housing: the role of social capital and sense of place
- Authors: Williams-Bruinders, Leizel
- Date: 2019
- Subjects: Housing -- South Africa , City planning -- South Africa Cities and towns -- Research Urban geography
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/44390 , vital:37161
- Description: In the past twenty years we have seen the South African government deliver the largest number of houses in the world (NDHS, 2011). However, this great effort does not appeal to the principles that policies have set out in terms of equality. Along with the delivery of this high level of state funded housing, many of the RDP dwellers feel as though they have been marginalised and forced out of the area of opportunity, namely, the CBD and the northern suburbs (Huchzermeyer, 2003). Many researchers believe that the South African housing delivery pattern resembles that of apartheid segregationist planning, which exacerbated the social inequalities in the country (Huchzermeyer, 2003; Donaldson, 2001; Harrison et al., 2003). To gain an in-depth understanding of the lived experiences of residents of a low-cost housing settlement, an interpretative phenomenological analysis was undertaken. The emergent themes emanating from the research study revealed that social problems were pertinent factors to the lack of formulation of community social cohesion. Without this aspect, community building will be hampered, and thus cohesive neighbourhoods will be lacking. To this end, social innovation is proposed as a solution to the Zanemvula development. The issue of social development needs to placed back on the housing agenda, as is stated in the latest Housing Act.
- Full Text:
- Date Issued: 2019
- Authors: Williams-Bruinders, Leizel
- Date: 2019
- Subjects: Housing -- South Africa , City planning -- South Africa Cities and towns -- Research Urban geography
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/44390 , vital:37161
- Description: In the past twenty years we have seen the South African government deliver the largest number of houses in the world (NDHS, 2011). However, this great effort does not appeal to the principles that policies have set out in terms of equality. Along with the delivery of this high level of state funded housing, many of the RDP dwellers feel as though they have been marginalised and forced out of the area of opportunity, namely, the CBD and the northern suburbs (Huchzermeyer, 2003). Many researchers believe that the South African housing delivery pattern resembles that of apartheid segregationist planning, which exacerbated the social inequalities in the country (Huchzermeyer, 2003; Donaldson, 2001; Harrison et al., 2003). To gain an in-depth understanding of the lived experiences of residents of a low-cost housing settlement, an interpretative phenomenological analysis was undertaken. The emergent themes emanating from the research study revealed that social problems were pertinent factors to the lack of formulation of community social cohesion. Without this aspect, community building will be hampered, and thus cohesive neighbourhoods will be lacking. To this end, social innovation is proposed as a solution to the Zanemvula development. The issue of social development needs to placed back on the housing agenda, as is stated in the latest Housing Act.
- Full Text:
- Date Issued: 2019
The synthesis and assessment of thioxanthone- and xanthone- derived compounds as hosts for application in host-guest chemistry
- Authors: Greyling, Lizé
- Date: 2019
- Subjects: Chemistry, Organic , Biochemistry
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/42525 , vital:36665
- Description: In this work, the host capabilities of two structurally related compounds, N,N’-bis(9-phenyl-9- thioxanthenyl)ethylenediamine (H1) and N,N’-bis(9-phenyl-9-xanthenyl)ethylenediamine (H2) were compared in the presence of a wide variety of guest species. Additionally, the selectivity displayed by these host compounds were examined when exposed to mixtures of guests in order to ascertain whether it would be feasible to employ them in alternative separation strategies for the purification of industrially relevant chemicals. H1 and H2 were synthesized by reacting thioxanthone and xanthone with phenylmagnesium bromide. The resultant alcohol was then treated with perchloric acid and, finally, two of these molecules were effectively linked by utilizing ethylenediamine to afford the two host compounds. Initially, H1 and H2 were investigated for their inclusion abilities by recrystallizing each from a number of potential isomeric and non-isomeric guest compounds such as the xylenes and ethylbenzene, methylanisoles and anisole, methylpyridines and pyridine, methylcyclohexanones and cyclohexanone, heterocyclic five- and six- membered ring compounds, alkylsubstituted benzenes, anilines, and dihaloalkanes. H1 displayed excellent inclusion ability when presented with the above-mentioned compounds, and a 1:1 H:G ratio was consistently preferred in each case. H2 also proved to be successful in this regard but did not include the methylcyclohexanones and cyclohexanone nor the heterocyclic five-membered ring solvents. Furthermore, varying host:guest ratios were observed for the complexes formed with H2. Mixed competition experiments were carried out in the presence of either isomeric or related but non-isomeric guest species. When H1 and H2 were independently recrystallized from mixtures of the former, selectivity orders correlated for both hosts, but it was observed that H2 exhibited an enhanced selectivity for the preferred guests in each case, compared with H1. Interestingly, in mixtures of the latter, host behaviours were distinctly opposing (with the exception of the dihaloalkanes). H1, and even more so H2, demonstrated very high selectivities for p-xylene, aniline and N,Ndimethylaniline from the xylene and aniline guest series, respectively, where selectivities were found to be ~90% or higher for host recrystallization experiments from respective mixtures of these guests. Single crystal X-ray diffraction, Hirshfeld surface and thermal analyses were employed in order to elucidate the reasons for any selectivity observations. The inclusion of these guests was, in most cases, found to be as a result of interactions between host and guest species, which included π∙∙∙π stacking, C‒H∙∙∙π, hydrogen bonding and various other short contact types. Guest compounds were accommodated in either cavities or channels and this was dependent on the nature of the guest. The host molecule conformations showed H1 to adopt a bent tricyclic fused ring system with the N atoms of the linker in a synclinal arrangement, while in complexes with H2, the fused ring system was near-planar and the N atoms adopted an antiperiplanar geometry. These key differences resulted in a very ordered host‒host packing for H2 as a direct result of the more planar O-containing ring and linear linker; for H1, on the other hand, the buckled S-containing ring and gauche-orientated N atoms resulted in a less ordered packing, which ultimately related to the differences in the behaviour of the two host species. Hirshfeld surface analyses, in general, did not provide much information to explain the host selectivities, with the exception of complexes containing the five-membered ring guest heterocyclics. Thermal analyses were completed on all suitable host-guest complexes and, in most cases but not all, the onset and peak temperatures (terms Ton and Tp, respectively) were related to the thermal stability of the complexes, which were used to rationalize the selectivities of these host compounds.
- Full Text:
- Date Issued: 2019
- Authors: Greyling, Lizé
- Date: 2019
- Subjects: Chemistry, Organic , Biochemistry
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/42525 , vital:36665
- Description: In this work, the host capabilities of two structurally related compounds, N,N’-bis(9-phenyl-9- thioxanthenyl)ethylenediamine (H1) and N,N’-bis(9-phenyl-9-xanthenyl)ethylenediamine (H2) were compared in the presence of a wide variety of guest species. Additionally, the selectivity displayed by these host compounds were examined when exposed to mixtures of guests in order to ascertain whether it would be feasible to employ them in alternative separation strategies for the purification of industrially relevant chemicals. H1 and H2 were synthesized by reacting thioxanthone and xanthone with phenylmagnesium bromide. The resultant alcohol was then treated with perchloric acid and, finally, two of these molecules were effectively linked by utilizing ethylenediamine to afford the two host compounds. Initially, H1 and H2 were investigated for their inclusion abilities by recrystallizing each from a number of potential isomeric and non-isomeric guest compounds such as the xylenes and ethylbenzene, methylanisoles and anisole, methylpyridines and pyridine, methylcyclohexanones and cyclohexanone, heterocyclic five- and six- membered ring compounds, alkylsubstituted benzenes, anilines, and dihaloalkanes. H1 displayed excellent inclusion ability when presented with the above-mentioned compounds, and a 1:1 H:G ratio was consistently preferred in each case. H2 also proved to be successful in this regard but did not include the methylcyclohexanones and cyclohexanone nor the heterocyclic five-membered ring solvents. Furthermore, varying host:guest ratios were observed for the complexes formed with H2. Mixed competition experiments were carried out in the presence of either isomeric or related but non-isomeric guest species. When H1 and H2 were independently recrystallized from mixtures of the former, selectivity orders correlated for both hosts, but it was observed that H2 exhibited an enhanced selectivity for the preferred guests in each case, compared with H1. Interestingly, in mixtures of the latter, host behaviours were distinctly opposing (with the exception of the dihaloalkanes). H1, and even more so H2, demonstrated very high selectivities for p-xylene, aniline and N,Ndimethylaniline from the xylene and aniline guest series, respectively, where selectivities were found to be ~90% or higher for host recrystallization experiments from respective mixtures of these guests. Single crystal X-ray diffraction, Hirshfeld surface and thermal analyses were employed in order to elucidate the reasons for any selectivity observations. The inclusion of these guests was, in most cases, found to be as a result of interactions between host and guest species, which included π∙∙∙π stacking, C‒H∙∙∙π, hydrogen bonding and various other short contact types. Guest compounds were accommodated in either cavities or channels and this was dependent on the nature of the guest. The host molecule conformations showed H1 to adopt a bent tricyclic fused ring system with the N atoms of the linker in a synclinal arrangement, while in complexes with H2, the fused ring system was near-planar and the N atoms adopted an antiperiplanar geometry. These key differences resulted in a very ordered host‒host packing for H2 as a direct result of the more planar O-containing ring and linear linker; for H1, on the other hand, the buckled S-containing ring and gauche-orientated N atoms resulted in a less ordered packing, which ultimately related to the differences in the behaviour of the two host species. Hirshfeld surface analyses, in general, did not provide much information to explain the host selectivities, with the exception of complexes containing the five-membered ring guest heterocyclics. Thermal analyses were completed on all suitable host-guest complexes and, in most cases but not all, the onset and peak temperatures (terms Ton and Tp, respectively) were related to the thermal stability of the complexes, which were used to rationalize the selectivities of these host compounds.
- Full Text:
- Date Issued: 2019