A vision based multirotor aircraft for use in the security industry
- Authors: Nelson, Benjamin David
- Date: 2020
- Subjects: Drone aircraft -- South Africa , Mechatronics -- Research
- Language: English
- Type: Thesis , Masters , MEng
- Identifier: http://hdl.handle.net/10948/46816 , vital:39664
- Description: This research consisted of developing a vision based multirotor aircraft that could be used in the security industry. A second-hand aircraft was purchased and modified. The aircraft made use of a Pixhawk flight controller and a Odroid XU4 companion computer, which resulted in the computer injecting commands into the flight controller. Robot Operating System was installed and used on the companion computer to integrate the vision system and the aircraft. The vision system was designed to help develop a landing system where the aircraft would land on an ArUco marker. The vision system also allowed the aircraft to detect and follow humans. A Software in the Loop (SITL) was run alongside Gazebo, allowing the developed landing system and the human detecting system to be simulated and tested. The developed landing system was implemented on the aircraft, where the developed landing system was tested and compared to the aircraft’s current GPS based landing system. The developed landing system obtained a better overall accuracy , while also taking longer to land the aircraft compared to the GPS based landing system. There were also numerous manual and autonomous test flights implemented on the aircraft.
- Full Text:
- Date Issued: 2020
- Authors: Nelson, Benjamin David
- Date: 2020
- Subjects: Drone aircraft -- South Africa , Mechatronics -- Research
- Language: English
- Type: Thesis , Masters , MEng
- Identifier: http://hdl.handle.net/10948/46816 , vital:39664
- Description: This research consisted of developing a vision based multirotor aircraft that could be used in the security industry. A second-hand aircraft was purchased and modified. The aircraft made use of a Pixhawk flight controller and a Odroid XU4 companion computer, which resulted in the computer injecting commands into the flight controller. Robot Operating System was installed and used on the companion computer to integrate the vision system and the aircraft. The vision system was designed to help develop a landing system where the aircraft would land on an ArUco marker. The vision system also allowed the aircraft to detect and follow humans. A Software in the Loop (SITL) was run alongside Gazebo, allowing the developed landing system and the human detecting system to be simulated and tested. The developed landing system was implemented on the aircraft, where the developed landing system was tested and compared to the aircraft’s current GPS based landing system. The developed landing system obtained a better overall accuracy , while also taking longer to land the aircraft compared to the GPS based landing system. There were also numerous manual and autonomous test flights implemented on the aircraft.
- Full Text:
- Date Issued: 2020
Addo Elephant National Park 1900 – 1955: An Environmental History of the struggle between elephants and emerging commercial farmers in the Sundays River Valley
- Jones,Nicholas Austen Inskip
- Authors: Jones,Nicholas Austen Inskip
- Date: 2020
- Subjects: Wildlife conservation -- South Africa -- Addo National Park
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/46922 , vital:39733
- Description: The research covers the first half of the 20th Century in the Sundays River Valley, and the relations between the elephants and the local farmers. The research includes some discussion of the implementation of new ideas to agriculture, irrigation, and colonial settlement with the interplay between the colonial farmers and the Administration. There is reference to the early politics surrounding nature conservation and the difficulties faced by farmers from wildlife and the difficulty wildlife face trying to co-exist alongside early intensive commercial agriculture.Included is the decision making process of the Colonial administration with reference to wildlife and agriculture relating to charismatic animal species.
- Full Text:
- Date Issued: 2020
- Authors: Jones,Nicholas Austen Inskip
- Date: 2020
- Subjects: Wildlife conservation -- South Africa -- Addo National Park
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/46922 , vital:39733
- Description: The research covers the first half of the 20th Century in the Sundays River Valley, and the relations between the elephants and the local farmers. The research includes some discussion of the implementation of new ideas to agriculture, irrigation, and colonial settlement with the interplay between the colonial farmers and the Administration. There is reference to the early politics surrounding nature conservation and the difficulties faced by farmers from wildlife and the difficulty wildlife face trying to co-exist alongside early intensive commercial agriculture.Included is the decision making process of the Colonial administration with reference to wildlife and agriculture relating to charismatic animal species.
- Full Text:
- Date Issued: 2020
Alternative pine species/hybrids for the Cape timber growing regions of South Africa
- Authors: Van der Hoef, André
- Date: 2020
- Subjects: Species -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/47613 , vital:40258
- Description: Pinus radiata has been the preferred commercial sawtimber species for the Cape forestry region for many years. Since the introduction of Fusarium circinatum, and the susceptibility of P. radiata to this disease, the sustainable production of this pine species for the Cape has been negatively impacted due to poor survival in the nursery and in field plantings. For this reason, a number of additional pine species and hybrids have been established in the Cape region of South Africa since 2006 to identify taxa that would perform as well as or better than P. radiata. Three research trials were implemented on contrasting sites that contained eight common species/hybrids treatments that included P. elliottii, P. elliottii x P. caribaea, P. radiata, P. patula x P. greggii var. australis, P. patula x P. oocarpa, P. patula x P. tecunumanii (HE), P. patula x P. tecunumanii (LE) and P. tecunumanii (HE) x P. oocarpa were established at Witelsbos, Kruisfontein and Garcia across diverse soil types, drainage and climate conditions in the Cape. Survival, growth data and tree morphology (forking, foxtails, broken tops and stem form) were assessed at five years of age and individual tree volume was calculated. Five year results indicate that on the waterlogged site at Witelsbos P. elliottii and its hybrid with P. caribaea was best in terms of productivity, at the dry site of Garcia, P. taeda and P. elliottii demonstrated promise, and at Kruisfontein, the most fertile site, P. elliottii x P. caribaea, P. patula x P. tecunumanii (LE) and P. maximinoi were found to be promising alternatives to P. radiata. Wood properties were assessed at Kruisfontein at six-years of age. Basic density and Modulus of Elasticity (MOE) were found to be significantly different for the various species/hybrids. Pinus patula x P. tecunumanii (LE), P. patula x P. greggii (S), P. maximinoi and P. patula x P. tecunumanii (HE) were all significantly better than P. radiata, which would suggest that these taxa would have similar or superior wood strength over P. radiata, the preferred sawtimber species for the Cape region. Only P. tecunumanii (HE) x P. oocarpa had a higher basic density than P. radiata, but not significantly different. Species that had similar basic density were P. patula x P. greggii (S), P. taeda and P. tecunumanii (LE) x P. caribaea. Although P. elliottii x P. caribaea had the highest volume at Witelsbos and Kruisfontein, the timber qualities were the worst, suggesting that some breeding is needed to improve this hybrid to be an acceptable sawtimber species. From this study, several potential alternative species/hybrids have been identified that are tolerant to the F. circinatum pathogen and have acceptable growth and wood properties, compared to P. radiata.
- Full Text:
- Date Issued: 2020
- Authors: Van der Hoef, André
- Date: 2020
- Subjects: Species -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/47613 , vital:40258
- Description: Pinus radiata has been the preferred commercial sawtimber species for the Cape forestry region for many years. Since the introduction of Fusarium circinatum, and the susceptibility of P. radiata to this disease, the sustainable production of this pine species for the Cape has been negatively impacted due to poor survival in the nursery and in field plantings. For this reason, a number of additional pine species and hybrids have been established in the Cape region of South Africa since 2006 to identify taxa that would perform as well as or better than P. radiata. Three research trials were implemented on contrasting sites that contained eight common species/hybrids treatments that included P. elliottii, P. elliottii x P. caribaea, P. radiata, P. patula x P. greggii var. australis, P. patula x P. oocarpa, P. patula x P. tecunumanii (HE), P. patula x P. tecunumanii (LE) and P. tecunumanii (HE) x P. oocarpa were established at Witelsbos, Kruisfontein and Garcia across diverse soil types, drainage and climate conditions in the Cape. Survival, growth data and tree morphology (forking, foxtails, broken tops and stem form) were assessed at five years of age and individual tree volume was calculated. Five year results indicate that on the waterlogged site at Witelsbos P. elliottii and its hybrid with P. caribaea was best in terms of productivity, at the dry site of Garcia, P. taeda and P. elliottii demonstrated promise, and at Kruisfontein, the most fertile site, P. elliottii x P. caribaea, P. patula x P. tecunumanii (LE) and P. maximinoi were found to be promising alternatives to P. radiata. Wood properties were assessed at Kruisfontein at six-years of age. Basic density and Modulus of Elasticity (MOE) were found to be significantly different for the various species/hybrids. Pinus patula x P. tecunumanii (LE), P. patula x P. greggii (S), P. maximinoi and P. patula x P. tecunumanii (HE) were all significantly better than P. radiata, which would suggest that these taxa would have similar or superior wood strength over P. radiata, the preferred sawtimber species for the Cape region. Only P. tecunumanii (HE) x P. oocarpa had a higher basic density than P. radiata, but not significantly different. Species that had similar basic density were P. patula x P. greggii (S), P. taeda and P. tecunumanii (LE) x P. caribaea. Although P. elliottii x P. caribaea had the highest volume at Witelsbos and Kruisfontein, the timber qualities were the worst, suggesting that some breeding is needed to improve this hybrid to be an acceptable sawtimber species. From this study, several potential alternative species/hybrids have been identified that are tolerant to the F. circinatum pathogen and have acceptable growth and wood properties, compared to P. radiata.
- Full Text:
- Date Issued: 2020
An Analysis of the Impact of Industry 4.0 on the Motor Industry in the Eastern Cape
- Authors: Dorothy, Liesel
- Date: 2020
- Subjects: Motor vehicle industry -- South Africa -- Eastern Cape.
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10948/47721 , vital:40329
- Description: Over the past decade we have noted the accelerated development in information technology which has resulted in the internet moving from merely connecting people via computers to its connections now being extended to connect virtually everything. It has changed the daily lives of humans, from how we communicate with each other and drive our vehicles to how we work as well. These advancements in technology have created smart technologies which give organisations and countries a competitive advantage when implemented. Developed countries in Europe and North America have invested significant sums of money in order to speed up the implementation of industry 4.0 given the benefits that can be derived from it. Literature on industry 4.0 is on the rise, however not many studies have been conducted in Africa or South Africa. The purpose of this research is to analyse the impact that industry 4.0 technologies have on the operational performance of an organisation in the automotive industry in the Eastern Cape in South Africa. The effects of these technologies on the operational performance of an organisation will be assessed on the key performance measures of: speed, flexibility, quality, delivery dependability and cost. The study also seeks to define a guideline for organisations to use who wish to implement these technologies into their operations. A literature review on the subject was conducted as well as an empirical investigation. The results from both the literature review and the empirical investigation found that the operational performance of an organisation improves with the implementation of technology.
- Full Text:
- Date Issued: 2020
- Authors: Dorothy, Liesel
- Date: 2020
- Subjects: Motor vehicle industry -- South Africa -- Eastern Cape.
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10948/47721 , vital:40329
- Description: Over the past decade we have noted the accelerated development in information technology which has resulted in the internet moving from merely connecting people via computers to its connections now being extended to connect virtually everything. It has changed the daily lives of humans, from how we communicate with each other and drive our vehicles to how we work as well. These advancements in technology have created smart technologies which give organisations and countries a competitive advantage when implemented. Developed countries in Europe and North America have invested significant sums of money in order to speed up the implementation of industry 4.0 given the benefits that can be derived from it. Literature on industry 4.0 is on the rise, however not many studies have been conducted in Africa or South Africa. The purpose of this research is to analyse the impact that industry 4.0 technologies have on the operational performance of an organisation in the automotive industry in the Eastern Cape in South Africa. The effects of these technologies on the operational performance of an organisation will be assessed on the key performance measures of: speed, flexibility, quality, delivery dependability and cost. The study also seeks to define a guideline for organisations to use who wish to implement these technologies into their operations. A literature review on the subject was conducted as well as an empirical investigation. The results from both the literature review and the empirical investigation found that the operational performance of an organisation improves with the implementation of technology.
- Full Text:
- Date Issued: 2020
An anthropoligical Inquiry on knowledge and understanding of Diabetes: a cultural analysis of knowledge construction amongst the youth in Humewood, Port Elizabeth
- Authors: Bota, Zizipho
- Date: 2020
- Subjects: Diabetes -- Port Elizabeth --South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/46659 , vital:39606
- Description: The study sought to inquire about the youth’s knowledge and understanding of diabetes in relation to its different types with regards to determined societal components such as education, culture, healthcare and socioeconomic status. It then became important to establish what the youth in Humewood, Port Elizabeth, understand about diabetes in relation to its three different types with regard to education, culture, healthcare and socioeconomic status in Humewood, Port Elizabeth. Previous studies have failed to inquire about knowledge construction and understanding of diabetes in Port Elizabeth, this provided an opportunity to do so, especially since diabetes is growing rapidly and is a lifelong illness. Most studies tend to focus on disseminating information to those that already have diabetes, overlooking the importance of diabetes education as a preventative strategy. The research followed a qualitative approach which included semi-structured individual face-to-face interviews as a method of data collection amongst ten participants using convenience sampling. The data revealed the importance of diabetes education and representation, and showed that financial standing and healthcare are interconnected. Complex inferiorities and social stratification hinder the betterment of the general welfare and therefore signifying social injustice. This research is an important contribution to medical anthropology in the context of Port Elizabeth, South Africa.
- Full Text:
- Date Issued: 2020
- Authors: Bota, Zizipho
- Date: 2020
- Subjects: Diabetes -- Port Elizabeth --South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/46659 , vital:39606
- Description: The study sought to inquire about the youth’s knowledge and understanding of diabetes in relation to its different types with regards to determined societal components such as education, culture, healthcare and socioeconomic status. It then became important to establish what the youth in Humewood, Port Elizabeth, understand about diabetes in relation to its three different types with regard to education, culture, healthcare and socioeconomic status in Humewood, Port Elizabeth. Previous studies have failed to inquire about knowledge construction and understanding of diabetes in Port Elizabeth, this provided an opportunity to do so, especially since diabetes is growing rapidly and is a lifelong illness. Most studies tend to focus on disseminating information to those that already have diabetes, overlooking the importance of diabetes education as a preventative strategy. The research followed a qualitative approach which included semi-structured individual face-to-face interviews as a method of data collection amongst ten participants using convenience sampling. The data revealed the importance of diabetes education and representation, and showed that financial standing and healthcare are interconnected. Complex inferiorities and social stratification hinder the betterment of the general welfare and therefore signifying social injustice. This research is an important contribution to medical anthropology in the context of Port Elizabeth, South Africa.
- Full Text:
- Date Issued: 2020
An educational intervention for professional nurses on the use of surgical attire in the prevention of surgical site infections in the operating theatres
- Authors: Alayemi, Joshua
- Date: 2020
- Subjects: Surgical wound infections -- Prevention , Surgical nursing Operating room nursing
- Language: English
- Type: Thesis , Masters , MCur
- Identifier: http://hdl.handle.net/10948/47937 , vital:40454
- Description: Infection control and prevention is an issue that is of utmost importance to every health practitioner, including professional nurses, as patients who undergo surgeries could develop sepsis, leading to failure of multiple organs and possibly death. Surgical site infections acquired from operating theatres are often introduced when there is lack of application of and adherence to the necessary control measures, sterile principles and techniques, including the appropriate use of surgical attire. This study aimed to contextualize, implement and evaluate an existing educational intervention regarding the use of surgical attire in operating theatres, in order to establish whether the educational intervention enhanced the practices of professional nurses in operating theatres regarding the use of surgical attire. A quantitative research design, using a quasi-experimental two-group pre-test, post-test intervention approach was employed for the study. The study consisted of three phases. Phase 1 consisted of the administration of the pre-test questionnaire relating to Objective One: “To explore and describe the practices of professional nurses on the use of surgical attire in the prevention of surgical site infections in operating theatres”. Phase 2 consisted of the contextualization and implementation of the educational intervention, which related to Objective Two: “To contextualize and implement an educational intervention for professional nurses on the use of surgical attire in the prevention of surgical site infections in operating theatres”. Phase 3 consisted of the administration of the posttest questionnaire, which related to Objective Three: “To evaluate whether an educational intervention regarding the use of surgical attire in the prevention of surgical site infections in operating theatres enhanced professional nurses’ practices”. The study is underpinned by the Promoting Action on Research Implementation (PARiHS) framework. The research sample consisted of all professional nurses working in the public and private operating theatres in the Nelson Mandela Bay Municipality. Purposive sampling was used to select the hospitals in control (Hospitals 2 and 3) and intervention groups (Hospitals 4 and 5), ensuring an equal number of public and private hospitals in each group. Data was collected through self-administered pre- and post-questionnaires. An existing educational intervention based on the Association of Perioperative Registered Nurses (AORN’s) guidelines was contextualized through review by three professional nurses with a specialty in operating theatre. The educational intervention was implemented for the intervention group, while the control group only received the summary of the AORN guidelines. Reliability and validity were ensured through the conduct of a pilot study, and expert review by three professional nurses with a specialty in operating theatre in order to check the validity and reliability of the data collection instrument and educational intervention. The data collection instrument was also reviewed by a statistician. Ethical clearance and permission was obtained from the relevant institutions. The following ethical principles were adhered to during the study: justice, respect and beneficence. The overall score of pre-test and post-test questionnaires for the control group revealed means of 3.96 and 4.01, with a standard deviation of 0.40 and 0.38, with a difference of -0.06 and a degree of freedom of 59. The overall score of the pre-test and post-test of the intervention group revealed means of 3.68 and 4.22, a standard deviation of 0.47 and 0.36, with a difference of -0.53, degree of freedom of 61 and a large significance difference of Cohen’s d= 1.26. This means that the educational intervention had a positive effect in terms of improving the professional nurses’ practices on the use of surgical attire to prevent surgical site infections in operating theatres. Recommendations for education, practice as well as future research were provided.
- Full Text:
- Date Issued: 2020
- Authors: Alayemi, Joshua
- Date: 2020
- Subjects: Surgical wound infections -- Prevention , Surgical nursing Operating room nursing
- Language: English
- Type: Thesis , Masters , MCur
- Identifier: http://hdl.handle.net/10948/47937 , vital:40454
- Description: Infection control and prevention is an issue that is of utmost importance to every health practitioner, including professional nurses, as patients who undergo surgeries could develop sepsis, leading to failure of multiple organs and possibly death. Surgical site infections acquired from operating theatres are often introduced when there is lack of application of and adherence to the necessary control measures, sterile principles and techniques, including the appropriate use of surgical attire. This study aimed to contextualize, implement and evaluate an existing educational intervention regarding the use of surgical attire in operating theatres, in order to establish whether the educational intervention enhanced the practices of professional nurses in operating theatres regarding the use of surgical attire. A quantitative research design, using a quasi-experimental two-group pre-test, post-test intervention approach was employed for the study. The study consisted of three phases. Phase 1 consisted of the administration of the pre-test questionnaire relating to Objective One: “To explore and describe the practices of professional nurses on the use of surgical attire in the prevention of surgical site infections in operating theatres”. Phase 2 consisted of the contextualization and implementation of the educational intervention, which related to Objective Two: “To contextualize and implement an educational intervention for professional nurses on the use of surgical attire in the prevention of surgical site infections in operating theatres”. Phase 3 consisted of the administration of the posttest questionnaire, which related to Objective Three: “To evaluate whether an educational intervention regarding the use of surgical attire in the prevention of surgical site infections in operating theatres enhanced professional nurses’ practices”. The study is underpinned by the Promoting Action on Research Implementation (PARiHS) framework. The research sample consisted of all professional nurses working in the public and private operating theatres in the Nelson Mandela Bay Municipality. Purposive sampling was used to select the hospitals in control (Hospitals 2 and 3) and intervention groups (Hospitals 4 and 5), ensuring an equal number of public and private hospitals in each group. Data was collected through self-administered pre- and post-questionnaires. An existing educational intervention based on the Association of Perioperative Registered Nurses (AORN’s) guidelines was contextualized through review by three professional nurses with a specialty in operating theatre. The educational intervention was implemented for the intervention group, while the control group only received the summary of the AORN guidelines. Reliability and validity were ensured through the conduct of a pilot study, and expert review by three professional nurses with a specialty in operating theatre in order to check the validity and reliability of the data collection instrument and educational intervention. The data collection instrument was also reviewed by a statistician. Ethical clearance and permission was obtained from the relevant institutions. The following ethical principles were adhered to during the study: justice, respect and beneficence. The overall score of pre-test and post-test questionnaires for the control group revealed means of 3.96 and 4.01, with a standard deviation of 0.40 and 0.38, with a difference of -0.06 and a degree of freedom of 59. The overall score of the pre-test and post-test of the intervention group revealed means of 3.68 and 4.22, a standard deviation of 0.47 and 0.36, with a difference of -0.53, degree of freedom of 61 and a large significance difference of Cohen’s d= 1.26. This means that the educational intervention had a positive effect in terms of improving the professional nurses’ practices on the use of surgical attire to prevent surgical site infections in operating theatres. Recommendations for education, practice as well as future research were provided.
- Full Text:
- Date Issued: 2020
An evaluation of programme management with reference to inner -city problem buildings: The case of Nelson Mandela Bay Metropolitan Municipality ,South Africa
- Conradie, Hendrik Francois, Shaidi,Walter
- Authors: Conradie, Hendrik Francois , Shaidi,Walter
- Date: 2020
- Subjects: Municipal government -- South Africa -- Port Elizabeth , Finance,Public --South Africa --Port Elizabeth
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/46670 , vital:39607
- Description: This research study is qualitative and cross-sectional in nature. Programme management by South African city governments is investigated and evaluated, as related to inner-city decay and problem (derelict; hijacked; dilapidated; overcrowded) buildings. A case study approach, focusing on the Nelson Mandela Bay Municipality in Port Elizabeth, South Africa, is utilised to understand the phenomenon, and to answer the research question. The significant challenge of inner-city and central business district problem buildings in major South African cities has prompted the study; no scientific research has previously been conducted or published on this topic The study started out with this research question, asked in a case study context: to what extent are programmes dealing with inner-city problem buildings and decay managed effectively by city government in South Africa? In the literature review the researcher focused on programme management theory, emphasising the usefulness of project management principles and practice in public sector programme management contexts. In a subsequent chapter the applicable constitutional and legislative frameworks were presented. The researcher developed, as outcome, strategic remedial legal options available to city governments when dealing with transgressing owners of problematic buildings. Problem building by-laws were dealt with in detail. A qualitative research approach, including semi-structured in-depth interviews with political and managerial leaders at the case study city government, assisted the researcher in effective data generation. Data analysis was performed with vigour, based on thematic content analysis.relevant coding practices were utilised in analysis and interpretation of data.
- Full Text:
- Date Issued: 2020
- Authors: Conradie, Hendrik Francois , Shaidi,Walter
- Date: 2020
- Subjects: Municipal government -- South Africa -- Port Elizabeth , Finance,Public --South Africa --Port Elizabeth
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/46670 , vital:39607
- Description: This research study is qualitative and cross-sectional in nature. Programme management by South African city governments is investigated and evaluated, as related to inner-city decay and problem (derelict; hijacked; dilapidated; overcrowded) buildings. A case study approach, focusing on the Nelson Mandela Bay Municipality in Port Elizabeth, South Africa, is utilised to understand the phenomenon, and to answer the research question. The significant challenge of inner-city and central business district problem buildings in major South African cities has prompted the study; no scientific research has previously been conducted or published on this topic The study started out with this research question, asked in a case study context: to what extent are programmes dealing with inner-city problem buildings and decay managed effectively by city government in South Africa? In the literature review the researcher focused on programme management theory, emphasising the usefulness of project management principles and practice in public sector programme management contexts. In a subsequent chapter the applicable constitutional and legislative frameworks were presented. The researcher developed, as outcome, strategic remedial legal options available to city governments when dealing with transgressing owners of problematic buildings. Problem building by-laws were dealt with in detail. A qualitative research approach, including semi-structured in-depth interviews with political and managerial leaders at the case study city government, assisted the researcher in effective data generation. Data analysis was performed with vigour, based on thematic content analysis.relevant coding practices were utilised in analysis and interpretation of data.
- Full Text:
- Date Issued: 2020
An evaluation of the effectiveness of communication between the education district office and schools in Nelson Mandela Bay
- Authors: Brown, Xenophon
- Date: 2020
- Subjects: Communication in organizations , Communication in management
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10948/50491 , vital:42203
- Description: This study focuses on an evaluation of communication effectiveness between the school administration office in Nelson Mandela Bay and its representative schools in advancing the business case of school development and heightened learner experience in line with the national development goal. The research uses a qualitative research approach to gather rich insights into the challenges, opportunities and problems that heighten and affect the quality of communication methods, channels and the roles of communication that the interviewed stakeholders representing both the district and schools depict and understand within the communication processes and methods used. Fourteen interviewees were identified using a judgemental and purposive sampling technique. They were identified from the Nelson Mandela Bay district office and schools within the district. Findings from the study reveal that the critical areas of concern include the roles of communication, stakeholder roles in the communication process, methods of communication, and challenges in communication effectiveness. While schools and the district office share the responsibility for providing quality education, it is critical that an effective communication strategy, which embraces computer-mediated communication as a supplementary tool, should be adopted to ensure that this shared mandate could be achieved.
- Full Text:
- Date Issued: 2020
- Authors: Brown, Xenophon
- Date: 2020
- Subjects: Communication in organizations , Communication in management
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10948/50491 , vital:42203
- Description: This study focuses on an evaluation of communication effectiveness between the school administration office in Nelson Mandela Bay and its representative schools in advancing the business case of school development and heightened learner experience in line with the national development goal. The research uses a qualitative research approach to gather rich insights into the challenges, opportunities and problems that heighten and affect the quality of communication methods, channels and the roles of communication that the interviewed stakeholders representing both the district and schools depict and understand within the communication processes and methods used. Fourteen interviewees were identified using a judgemental and purposive sampling technique. They were identified from the Nelson Mandela Bay district office and schools within the district. Findings from the study reveal that the critical areas of concern include the roles of communication, stakeholder roles in the communication process, methods of communication, and challenges in communication effectiveness. While schools and the district office share the responsibility for providing quality education, it is critical that an effective communication strategy, which embraces computer-mediated communication as a supplementary tool, should be adopted to ensure that this shared mandate could be achieved.
- Full Text:
- Date Issued: 2020
An evaluation of the integrative propositional analysis model for complex policy environments:The case of the Drakenstein housing policy, 2010-2017
- Authors: De Wee, Guswin
- Date: 2020
- Subjects: Housing policy -- South Africa -- Drakenstein
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/46681 , vital:39608
- Description: This study evaluates the Integrative Propositional Analysis (IPA) (Wallis, 2015), and its usefulness as a complementary model for analysing and evaluating public policy and policy implementation. The IPA model is evaluated in this longitudinal study and seeks to establish the validity of the correlation between the historically implemented results of the Drakenstein Local Municipality Housing Policy against the complexity and systemicity scores of the policy between 2010 and 2017. The IPA model predicts that the higher the complexity and systemicity of the internal logic structure of a policy, the more useful and effective the policy will be, and for its successful implementation. The model is premised on the idea that policies are more useful when they have some level of structure and has been accepted widely for some time (Wallis, 2018). The study thus is an evaluation of the usefulness of the model as complementing policy analysis and evaluation for successful implementation based on the policy internal structure. The research study provided a brief historical background on the development of the IPA and locates it as a ‗science two‘ model based on its systems thinking and Complexity Theory properties to policy analysis. An extensive literature review was undertaken, and secondary data was gathered and analysed to gauge the policy‘s historical success. In examining the Drakenstein‘s housing policy outcomes for evaluating the IPA model, the study adopted both qualitative and quantitative approaches for this exploratory descriptive report. The diagnosis indicated that the revised targets, introduced during the implementation altered the vision of the policy. This allowed for an analysis of the low structure of the policy and its inability to create integrated sustainable human settlements.
- Full Text:
- Date Issued: 2020
- Authors: De Wee, Guswin
- Date: 2020
- Subjects: Housing policy -- South Africa -- Drakenstein
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/46681 , vital:39608
- Description: This study evaluates the Integrative Propositional Analysis (IPA) (Wallis, 2015), and its usefulness as a complementary model for analysing and evaluating public policy and policy implementation. The IPA model is evaluated in this longitudinal study and seeks to establish the validity of the correlation between the historically implemented results of the Drakenstein Local Municipality Housing Policy against the complexity and systemicity scores of the policy between 2010 and 2017. The IPA model predicts that the higher the complexity and systemicity of the internal logic structure of a policy, the more useful and effective the policy will be, and for its successful implementation. The model is premised on the idea that policies are more useful when they have some level of structure and has been accepted widely for some time (Wallis, 2018). The study thus is an evaluation of the usefulness of the model as complementing policy analysis and evaluation for successful implementation based on the policy internal structure. The research study provided a brief historical background on the development of the IPA and locates it as a ‗science two‘ model based on its systems thinking and Complexity Theory properties to policy analysis. An extensive literature review was undertaken, and secondary data was gathered and analysed to gauge the policy‘s historical success. In examining the Drakenstein‘s housing policy outcomes for evaluating the IPA model, the study adopted both qualitative and quantitative approaches for this exploratory descriptive report. The diagnosis indicated that the revised targets, introduced during the implementation altered the vision of the policy. This allowed for an analysis of the low structure of the policy and its inability to create integrated sustainable human settlements.
- Full Text:
- Date Issued: 2020
An evaluation of the organisational performance of members of the district based support team in inclusive education – a case study of the Grahamstown circuit
- Authors: Dyantyi, Khona
- Date: 2020
- Subjects: Education -- South Africa -- Grahamstown -- Administration
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10948/47868 , vital:40391
- Description: Inclusive learning around the world takes into account both the rights of learners and how education systems can adapt in just and equitable ways to respond to learner differences. White Paper 6, launched by the Department of Education in 2001, has been praised in this regard as a groundbreaking post-Apartheid strategy that provides the vision and basis for turning the fragmented and unequal education system in South Africa into one that is inclusive. This represents a fundamental change from an academic placement process throughout the education system to an influx of educational support services. This study specifically explores how one Eastern Cape District Based Support Team perceives its roles and responsibilities. To investigate these viewpoints, a qualitative research model was used within an interpretive framework. For the choice of participants in the study, purposeful sampling methods were used. Data was collected and analysed using thematic data analysis through semi-structured individual interviews and a single focus group interview. The following key findings were revealed in the results. On the one hand, there are significant factors that allow the efficacy of District Based Support Teams as enabling agents of inclusion to be supported. These include: • A substantial degree of alignment between inclusive education theory and current inclusive education policy; • Enabling inclusive education policy and guidelines; • The interpretation of inclusive education by research participants and the goals of inclusive education are aligned with the policy they see as a framework to direct and encourage their practice; • The District Based Support Team's view of their position is basically that of support service with the primary responsibility to allow inclusive learning to be implemented. On the other hand, structural debilitating factors substantially weaken these teams ' effectiveness. These include:South African School and Administration Management System • Early identification of obstacles and admission age • Budget • Support tools/ equipment • Human Resources - human and physical resources • The unproductive inclusion of special schools as resource centres in the District Based Support Teams. • Poor infrastructure • Coordination and cooperation with the National DoE to enforce IE policies. Years after its adoption, the key challenge remains the translation of encouraging policy language into practical action at all levels of the process within the broader context of the failure of Inclusive Education Policy to have any significant impact on the education system. At the district level, it needs innovative leadership across the Specialised Education Support Unit (including District Based Teams and Special School Resource Centers) and firm management within it to allow organisational coordination and intersectoral cooperation within an integrated community context.
- Full Text:
- Date Issued: 2020
- Authors: Dyantyi, Khona
- Date: 2020
- Subjects: Education -- South Africa -- Grahamstown -- Administration
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10948/47868 , vital:40391
- Description: Inclusive learning around the world takes into account both the rights of learners and how education systems can adapt in just and equitable ways to respond to learner differences. White Paper 6, launched by the Department of Education in 2001, has been praised in this regard as a groundbreaking post-Apartheid strategy that provides the vision and basis for turning the fragmented and unequal education system in South Africa into one that is inclusive. This represents a fundamental change from an academic placement process throughout the education system to an influx of educational support services. This study specifically explores how one Eastern Cape District Based Support Team perceives its roles and responsibilities. To investigate these viewpoints, a qualitative research model was used within an interpretive framework. For the choice of participants in the study, purposeful sampling methods were used. Data was collected and analysed using thematic data analysis through semi-structured individual interviews and a single focus group interview. The following key findings were revealed in the results. On the one hand, there are significant factors that allow the efficacy of District Based Support Teams as enabling agents of inclusion to be supported. These include: • A substantial degree of alignment between inclusive education theory and current inclusive education policy; • Enabling inclusive education policy and guidelines; • The interpretation of inclusive education by research participants and the goals of inclusive education are aligned with the policy they see as a framework to direct and encourage their practice; • The District Based Support Team's view of their position is basically that of support service with the primary responsibility to allow inclusive learning to be implemented. On the other hand, structural debilitating factors substantially weaken these teams ' effectiveness. These include:South African School and Administration Management System • Early identification of obstacles and admission age • Budget • Support tools/ equipment • Human Resources - human and physical resources • The unproductive inclusion of special schools as resource centres in the District Based Support Teams. • Poor infrastructure • Coordination and cooperation with the National DoE to enforce IE policies. Years after its adoption, the key challenge remains the translation of encouraging policy language into practical action at all levels of the process within the broader context of the failure of Inclusive Education Policy to have any significant impact on the education system. At the district level, it needs innovative leadership across the Specialised Education Support Unit (including District Based Teams and Special School Resource Centers) and firm management within it to allow organisational coordination and intersectoral cooperation within an integrated community context.
- Full Text:
- Date Issued: 2020
An inquiry on the efficacy of structures by South African government to promote intergration of traditional medicine and modern medicine: A case of Mossel Bay, Western Cape Province
- Authors: Heynes, Derick Vincent
- Date: 2020
- Subjects: Traditional medicine -- South Africa -- Western cape
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/46890 , vital:39723
- Description: The two health systems are currently functioning parallel to one another as it seeks to contribute towards improving the health care delivery systems in South Africa. The myriad of literature available on the topic has nudged this phenomenon into the spotlight, and this realisation became even more apparent since South Africa’s transition from a system of separate development (also known as apartheid) to a democratic dispensation in 1994. Traditional Medicine, also known as folk medicine or complementary and Alternative Medicine (also known as CAM), is regarded as the oldest form of health care system that has been around since the dawn of time. It is in ancient cultures that method of healing have used to cope and deal with various diseases that have threatened their existence and survival (Abdullahi, 2011). Botha (2004) puts it succinctly as she notes that the clash between traditional methods of healing and Western medical science in places like South Africa requires that we ask questions like “What is health?” “What does healing mean?” and outlines that the contemporary move towards the recognition of alternative medicine is concurrent with a shift in Western thinking on the nature of science, healing and human being. These concepts namely; “What is health?” and “What does healing mean?” will be expounded in the chapters that follow. The researcher concurs with Botha (2004) views in that access to basic health services, as well as related infrastructure, such as water supplies, sanitary works and roads, generally remains one of the biggest problems on the continent and this has a huge impact on health care delivery systems, particularly in South Africa.
- Full Text:
- Date Issued: 2020
- Authors: Heynes, Derick Vincent
- Date: 2020
- Subjects: Traditional medicine -- South Africa -- Western cape
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/46890 , vital:39723
- Description: The two health systems are currently functioning parallel to one another as it seeks to contribute towards improving the health care delivery systems in South Africa. The myriad of literature available on the topic has nudged this phenomenon into the spotlight, and this realisation became even more apparent since South Africa’s transition from a system of separate development (also known as apartheid) to a democratic dispensation in 1994. Traditional Medicine, also known as folk medicine or complementary and Alternative Medicine (also known as CAM), is regarded as the oldest form of health care system that has been around since the dawn of time. It is in ancient cultures that method of healing have used to cope and deal with various diseases that have threatened their existence and survival (Abdullahi, 2011). Botha (2004) puts it succinctly as she notes that the clash between traditional methods of healing and Western medical science in places like South Africa requires that we ask questions like “What is health?” “What does healing mean?” and outlines that the contemporary move towards the recognition of alternative medicine is concurrent with a shift in Western thinking on the nature of science, healing and human being. These concepts namely; “What is health?” and “What does healing mean?” will be expounded in the chapters that follow. The researcher concurs with Botha (2004) views in that access to basic health services, as well as related infrastructure, such as water supplies, sanitary works and roads, generally remains one of the biggest problems on the continent and this has a huge impact on health care delivery systems, particularly in South Africa.
- Full Text:
- Date Issued: 2020
An internal audit expectation gap: South African Revenue Services project audit engagements
- Authors: Sekhwela, Mmanapo Bella
- Date: 2020
- Subjects: Electronic data processing -- Auditing , Business enterprises -- Computer networks -- Security measures Information technology -- Security measures Computer security
- Language: English
- Type: Thesis , Masters , MPhil
- Identifier: http://hdl.handle.net/10948/47139 , vital:39815
- Description: South African Revenue Services (SARS) was established as a quasi-government organisation with a mandate to efficiently and effectively collect revenue based on the export, import, movement, manufacture and storage of specific goods. Information Technology (IT) governance is strategically important to SARS in that its business processes are technology driven and that technology projects are implemented to support the SARS strategic objectives. In alignment to the King code for corporate governance and ethical business practices, an Internal Audit Function (IAF) as a regulatory requirement of all public sector entities in South Africa exists at SARS. The aim of the research was to evaluate the perspectives of SARS stakeholders regarding the organisation’s IT project auditing process. The study focused on gathering data from various SARS stakeholders involved in the delivery of IT projects and IT projects auditing. Through a qualitative research approach, interviews were conducted with practitioners such as Internal Auditors, Internal Audit managers, and executives as well as project managers and ownersso asto obtain a holistic understanding of stakeholder expectations of an IT project audit. An analysis of the data collected led to the deduction of recommendations meant to enhance stakeholder perceptions of the IT audit function within SARS. The study found that there is a perceived value derived from IA reviews of IT projects. The findings also revealed that rather than lack of resources and expertise, skill set deficiencies were the major setback in achieving IA goals. The findings further revealed that there are deficiencies in the quality of IA reports. Some of the main recommendations were to expand the scope of the Internal Audit roles, intensify engagements of Internal Audits by the Enterprise Project Management Office (EPMO), improve the quality of reports, and capacitate Internal Auditors with reporting skills. This study presents a modest contribution that is expected to enrich knowledge on how to audit IT projects. Moreover, the study contributes towards a methodological position of design science by producing results from a smaller sample augmented by interview results in an environment characterised by smaller populations so that inferences can be made.
- Full Text:
- Date Issued: 2020
- Authors: Sekhwela, Mmanapo Bella
- Date: 2020
- Subjects: Electronic data processing -- Auditing , Business enterprises -- Computer networks -- Security measures Information technology -- Security measures Computer security
- Language: English
- Type: Thesis , Masters , MPhil
- Identifier: http://hdl.handle.net/10948/47139 , vital:39815
- Description: South African Revenue Services (SARS) was established as a quasi-government organisation with a mandate to efficiently and effectively collect revenue based on the export, import, movement, manufacture and storage of specific goods. Information Technology (IT) governance is strategically important to SARS in that its business processes are technology driven and that technology projects are implemented to support the SARS strategic objectives. In alignment to the King code for corporate governance and ethical business practices, an Internal Audit Function (IAF) as a regulatory requirement of all public sector entities in South Africa exists at SARS. The aim of the research was to evaluate the perspectives of SARS stakeholders regarding the organisation’s IT project auditing process. The study focused on gathering data from various SARS stakeholders involved in the delivery of IT projects and IT projects auditing. Through a qualitative research approach, interviews were conducted with practitioners such as Internal Auditors, Internal Audit managers, and executives as well as project managers and ownersso asto obtain a holistic understanding of stakeholder expectations of an IT project audit. An analysis of the data collected led to the deduction of recommendations meant to enhance stakeholder perceptions of the IT audit function within SARS. The study found that there is a perceived value derived from IA reviews of IT projects. The findings also revealed that rather than lack of resources and expertise, skill set deficiencies were the major setback in achieving IA goals. The findings further revealed that there are deficiencies in the quality of IA reports. Some of the main recommendations were to expand the scope of the Internal Audit roles, intensify engagements of Internal Audits by the Enterprise Project Management Office (EPMO), improve the quality of reports, and capacitate Internal Auditors with reporting skills. This study presents a modest contribution that is expected to enrich knowledge on how to audit IT projects. Moreover, the study contributes towards a methodological position of design science by producing results from a smaller sample augmented by interview results in an environment characterised by smaller populations so that inferences can be made.
- Full Text:
- Date Issued: 2020
An investigation of the link between Financial sector development and economic growth in Zimbabwe from 1980 -2016
- Authors: Machokoto, Sydney
- Date: 2020
- Subjects: Financial institutions-- Zimbambwe , Economic growth, development,planning -- Zimbabwe
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/49894 , vital:41814
- Description: This study investigated the link between financial sector development and economic growth in Zimbabwe from 1980 to 2016 using the Auto Regressive Distributed Lag model. Market capitalization as a ratio of gross domestic product (GDP), bank credit to the private sector as a ratio of GDP and financial assets of microfinance as a ratio of GDP were used as proxy variables for financial sector development. Economic growth was measured by real GDP. The Granger causality test indicated bi-directional causality between access to financial services and economic growth in Zimbabwe in the long run. Market capitalization and bank credit to the private sector did not Granger cause economic growth in Zimbabwe. It was recommended that the government should promote the functioning of the capital market as it is the conduit for providing long term capital to businesses. Bank credit to the private sector was found to be statistically significant. It was recommended that the government should promote decentralization of the banking sector to rural areas. The proxy variables of financial development used were statistically significant in influencing economic growth. The findings from the study led to the recommendation to open additional microfinance companies in remote areas and to increase the supply of financial services and products. Empirical evidence indicates that the link between financial development and economic growth depends on the proxy variables of financial sector development used in econometric modelling. The model was tested for heteroscedasticity, serial correlation, stability and normality. The econometric tests conducted were all satisfactory. This made the model ideal for policy formulation and recommendation.
- Full Text:
- Date Issued: 2020
- Authors: Machokoto, Sydney
- Date: 2020
- Subjects: Financial institutions-- Zimbambwe , Economic growth, development,planning -- Zimbabwe
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/49894 , vital:41814
- Description: This study investigated the link between financial sector development and economic growth in Zimbabwe from 1980 to 2016 using the Auto Regressive Distributed Lag model. Market capitalization as a ratio of gross domestic product (GDP), bank credit to the private sector as a ratio of GDP and financial assets of microfinance as a ratio of GDP were used as proxy variables for financial sector development. Economic growth was measured by real GDP. The Granger causality test indicated bi-directional causality between access to financial services and economic growth in Zimbabwe in the long run. Market capitalization and bank credit to the private sector did not Granger cause economic growth in Zimbabwe. It was recommended that the government should promote the functioning of the capital market as it is the conduit for providing long term capital to businesses. Bank credit to the private sector was found to be statistically significant. It was recommended that the government should promote decentralization of the banking sector to rural areas. The proxy variables of financial development used were statistically significant in influencing economic growth. The findings from the study led to the recommendation to open additional microfinance companies in remote areas and to increase the supply of financial services and products. Empirical evidence indicates that the link between financial development and economic growth depends on the proxy variables of financial sector development used in econometric modelling. The model was tested for heteroscedasticity, serial correlation, stability and normality. The econometric tests conducted were all satisfactory. This made the model ideal for policy formulation and recommendation.
- Full Text:
- Date Issued: 2020
An investigation of the morphological and electrochemical properties of anode titanate materials used in li-ion batteries
- Authors: Gelant, Charmaine
- Date: 2020
- Subjects: Electrodes
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/48346 , vital:40851
- Description: The chemistry involved in the synthesis of lithium titanium oxide (Li4Ti5O12) for lithium ion battery applications is critical for understanding and optimizing the most cost-efficient manufacturing route. This study investigates the sol-gel synthesis technique of Li4Ti5O12 using triethanolamine (TEOA) as complexing agent by means of in-situ Powder X-ray Diffraction (PXRD). The influence of doping with various metals such as Al3+, Mg2+ , Co3+ and Ni2+ that were made as precursors was considered for comparison purposes due to literature showing improved electrochemical performance using the molecular formula of Li4Ti4.95M0.05O12. The in-situ PXRD technique was used to identify the phase changes that occurred in the thermal synthesis process from the sol-gel precursors to the final crystalline oxides. The materials’ decomposition mechanisms were characterized by thermal gravimetric analysis (TGA) as the precursors were gradually heated to obtain the final oxides. BET surface area analysis and scanning electron microscopy (SEM) were used in order to obtain a morphological understanding of the materials during the synthetic route at specific temperature regions. The in-situ studies have shown that the precursor materials are amorphous at room temperature to about 550 °C, after which the spinel and anatase formed, with relatively small crystallites and a large surface area. The study also showed that a crystalline intermediate phase formed at around 150-200 °C, which then disappeared above 250 °C and was speculated to be a titanium acid (H2Ti2O5.H2O). Upon further heating above 250 °C, the anatase phase converted to the high temperature stable TiO2 phase, rutile, also with an increased formation of the expected LTO spinel phase around 850 °C. Keeping the material at 850 °C, isothermally, did show further conversion of the rutile into the desired spinel phase Li4Ti5O12 (LTO) with an increase in the crystallite size and a decrease in surface area. SEM analysis of the material at 850 °C did show some extensive sintering of the particles with some samples indicating the presence of an additional β-Li2TiO3 phase that formed at the high temperatures. Upon cooling, the βLi2TiO3 phase showed a distinctive powder diffraction pattern besides the typical spinel II LTO phase. The study showed that in comparison to the oxide formed at 850 °C, a mixed phase material of the spinel LTO, anatase and rutile could be achieved at temperatures close to 650 °C with very small crystallites and a relatively large surface area that showed desirable electrochemical properties. Suitable Li-ion coin cells were built with the undoped spinel and doped materials that were isothermally made at 650 °C and 850 °C, whereby their electrochemical properties were tested in the form of cell capacity, electrochemical impedance spectroscopy (EIS) and differential capacity (dQ/dV) studies. The cells made with the materials at 850 °C provided reasonable capacity where the dQ/dV plots did show a single step redox reaction at around 1.5V vs Li/Li+ . These were compared to cells made with commercially available LTO and highlighted the importance of high surface area and small particle size of the active material in order to achieve acceptable electrochemical performances. The cells with the materials made at 650 °C showed to have good capacity upon the first discharge with a number of irreversible phase transitions that were subsequently not observed upon recharging. The dQ/dV graphs showed that the phase transitions were unique to the mixed phase composition of the material made at low temperatures and the cells made with the doped spinel materials were on average better performing than the undoped LTO material. Subsequent grinding steps of the active material made at 850 °C improved the capacity performance of the cells but were still lower when compared to the commercially available material. Hence, significantly longer grinding and processing time would be required to achieve battery active materials that are acceptable for commercial use. This study highlights the importance of understanding the phase transitions that occur during the synthesis route of making battery active material, where doping with different elements and using lower temperatures during synthesis could lead to electroactive materials that do not require additional excessive processing steps such as grinding.
- Full Text:
- Date Issued: 2020
- Authors: Gelant, Charmaine
- Date: 2020
- Subjects: Electrodes
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/48346 , vital:40851
- Description: The chemistry involved in the synthesis of lithium titanium oxide (Li4Ti5O12) for lithium ion battery applications is critical for understanding and optimizing the most cost-efficient manufacturing route. This study investigates the sol-gel synthesis technique of Li4Ti5O12 using triethanolamine (TEOA) as complexing agent by means of in-situ Powder X-ray Diffraction (PXRD). The influence of doping with various metals such as Al3+, Mg2+ , Co3+ and Ni2+ that were made as precursors was considered for comparison purposes due to literature showing improved electrochemical performance using the molecular formula of Li4Ti4.95M0.05O12. The in-situ PXRD technique was used to identify the phase changes that occurred in the thermal synthesis process from the sol-gel precursors to the final crystalline oxides. The materials’ decomposition mechanisms were characterized by thermal gravimetric analysis (TGA) as the precursors were gradually heated to obtain the final oxides. BET surface area analysis and scanning electron microscopy (SEM) were used in order to obtain a morphological understanding of the materials during the synthetic route at specific temperature regions. The in-situ studies have shown that the precursor materials are amorphous at room temperature to about 550 °C, after which the spinel and anatase formed, with relatively small crystallites and a large surface area. The study also showed that a crystalline intermediate phase formed at around 150-200 °C, which then disappeared above 250 °C and was speculated to be a titanium acid (H2Ti2O5.H2O). Upon further heating above 250 °C, the anatase phase converted to the high temperature stable TiO2 phase, rutile, also with an increased formation of the expected LTO spinel phase around 850 °C. Keeping the material at 850 °C, isothermally, did show further conversion of the rutile into the desired spinel phase Li4Ti5O12 (LTO) with an increase in the crystallite size and a decrease in surface area. SEM analysis of the material at 850 °C did show some extensive sintering of the particles with some samples indicating the presence of an additional β-Li2TiO3 phase that formed at the high temperatures. Upon cooling, the βLi2TiO3 phase showed a distinctive powder diffraction pattern besides the typical spinel II LTO phase. The study showed that in comparison to the oxide formed at 850 °C, a mixed phase material of the spinel LTO, anatase and rutile could be achieved at temperatures close to 650 °C with very small crystallites and a relatively large surface area that showed desirable electrochemical properties. Suitable Li-ion coin cells were built with the undoped spinel and doped materials that were isothermally made at 650 °C and 850 °C, whereby their electrochemical properties were tested in the form of cell capacity, electrochemical impedance spectroscopy (EIS) and differential capacity (dQ/dV) studies. The cells made with the materials at 850 °C provided reasonable capacity where the dQ/dV plots did show a single step redox reaction at around 1.5V vs Li/Li+ . These were compared to cells made with commercially available LTO and highlighted the importance of high surface area and small particle size of the active material in order to achieve acceptable electrochemical performances. The cells with the materials made at 650 °C showed to have good capacity upon the first discharge with a number of irreversible phase transitions that were subsequently not observed upon recharging. The dQ/dV graphs showed that the phase transitions were unique to the mixed phase composition of the material made at low temperatures and the cells made with the doped spinel materials were on average better performing than the undoped LTO material. Subsequent grinding steps of the active material made at 850 °C improved the capacity performance of the cells but were still lower when compared to the commercially available material. Hence, significantly longer grinding and processing time would be required to achieve battery active materials that are acceptable for commercial use. This study highlights the importance of understanding the phase transitions that occur during the synthesis route of making battery active material, where doping with different elements and using lower temperatures during synthesis could lead to electroactive materials that do not require additional excessive processing steps such as grinding.
- Full Text:
- Date Issued: 2020
Analysis of the effectiveness of Tulbaghia Violacea extracts as devulcanizing agents for synthetic CIS-1,4-polyisoprene vulcanizates
- Authors: Gxakuma, Lutho
- Date: 2020
- Subjects: Plant extracts , Plant products -- South Africa Medicinal plants -- South Africa Plants -- Analysis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/49093 , vital:41600
- Description: Tulbaghia violacea is an indigenous plant commonly known as wild garlic, wilde knoffel in Afrikaans, isihaqa in Zulu or itswele lomlambo in Xhosa. Its leaves and bulbs are widely used as herbal remedies for various ailments and its medicinal uses include fever and colds, asthma, tuberculosis and stomach problems. Like all other members of the Alliacea family, Tulbaghia violacea produces a distinctive garlic-like odour when its leaves or rhizomes are damaged, resulting in the release of cysteine-derived sulphur compounds which include the oil-soluble organo-sulphur compounds and water-soluble cysteine derivatives. Chemically synthesized sulphur containing compounds have been reported to be effective devulcanizing agents and many industries prefer to perform devulcanization using them. Most commonly applied devulcanizing agents include disulphides, thiophenols and their zinc salts, and mercaptans which are mixed with the rubber scrap powder under specific reaction conditions. In this study, instead of performing devulcanization by using industrial synthesized sulphur containing compounds, the effectiveness of the extracts of organo-sulphur containing compounds from Tulbaghia violacea are evaluated as potential devulcanizing agents for synthetic cis-1,4-polyisoprene vulcanizates. This is a new, cheap and greener practice of rubber devulcanization. Diallyl disulphide, which is one of the organo-sulphur containing compounds present in Tulbaghia violacea, is the devulcanizing agent of interest to this study. The organo-sulphur containing compounds were extracted from the bulbs, roots and leaves of the plant using the soxhlet and ultrasonic bath extraction method. The solvent system used in the soxhlet extraction method was 2% of 2-propanol in n-hexane whereas in ultrasonic bath extraction method the solvent system used was 100% ethanol. An essential oil extract was obtained from the plant organs. The yield of the essential oil extracts obtained using the soxhlet extraction method was higher compared to the yield of the essential oil extracts obtained using the ultrasonic bath extraction method. According to the Fourier-Transform Infrared spectroscopy, the organo-sulphur containing compounds were present in the essential oil extracts of the plant. The essential oil extracts that were extracted using the soxhlet extraction method were chosen for further analysis. It was found out that the allyl sulphide and diallyl disulphide have the same retention time from the High Performance Liquid Chromatography (using a normal phase column). The Differential Scanning Calorimeter indicated that the allyl sulphide was not present in the essential oil extracts whereas the diallyl disulphide was present in the essential oil extract of the roots and leaves. The High Performance Liquid Chromatography was used to quantify the presence of the diallyl disulphide in the essential oil extract of roots and leaves. The quantity of diallyl disulphide was 23% in the dry mass of the essential oil extract of roots. In the essential oil extract of leaves the diallyl disulphide was very low concentrated and the High Performance Liquid Chromatography was less sensitive to detect it. According to the Thermogravimetric Analyser, it was found that the essential oil extracts begin to degrade at 120 °C and experience a multistage degradation. The softening temperature of the essential oil extracts was 60 °C from the Simultaneous Differential Scanning Calorimeter-Thermogravimetric Analyser. Conventional vulcanization of synthetic cis-1,4-polyisoprene was prepared with the vulcanization ingredients of zinc oxide, sulphur, stearic acid and N-tert-butyl-2-benzothiazole sulphenamide. The vulcanized synthetic cis-1,4-polyisoprene produced, under the heating temperature of 160 °C, was mixed with the essential oil extracts using the internal mixer at 60 °C and the two-roll mill. The overall torque, tan delta and the total crosslink density were the properties of interest of synthetic cis-1,4-polyisoprene vulcanizate in this study. The devulcanization temperature for the treated synthetic cis-1,4-polyisoprene vulcanizate with the essential oil extracts was optimized using the Dynamic Moving Die Rheometer and Dynamic Rubber Process Analyser. The amount of essential oil extracts at which they are effective devulcanizing agents for synthetic cis-1,4-polyisoprene vulcanizate was also optimized. During optimization a change on the latter mentioned properties of synthetic cis-1,4-polyisoprene vulcanizate was observed, indicating that the essential oil extracts have an effect as potential devulcanizing agents. The essential oil extracts increased the tan delta and reduced the overall torque, and total crosslink density of synthetic cis-1,4-polyisoprene vulcanizate as expected from devulcanizing agents. 200 °C was a preferable devulcanization temperature whereas essential oil extracts were effective as devulcanizing agent at 1.4%. However, the essential oil extracts influenced the overall torque and tan delta of synthetic cis-1,4-polyisoprene vulcanizate during the mixing process in the internal mixer at 60 °C, which was before heating at 200 °C. The essential oil extracts had a higher influence on the overall torque of synthetic cis-1,4-polyisoprene vulcanizate under heating at 200 °C whereas at 60 °C, during the mixing process, they had a higher influence on the tan delta of synthetic cis-1,4-polyisoprene vulcanizate. The essential oil extract of leaves had a higher influence on the overall torque whereas the essential oil extract of bulbs had a higher influence on the tan delta of synthetic cis-1,4-polyisoprene vulcanizate at 200 °C. The essential oil extract of roots shown a greater influence on the overall torque and tan delta of synthetic cis-1,4-polyisoprene vulcanizate at 60 °C during the mixing process. The effect of the essential oil extracts on the reversing heat capacity of synthetic cis-1,4-polyisoprene vulcanizate was also investigated using the Modulated Differential Scanning Calorimetry method. The essential oil extract of bulbs and roots influenced the reversing heat capacity of synthetic cis-1,4-polyisoprene vulcanizate by reducing it whereas the essential oil extract of leaves caused a temperature shift of the reversing heat capacity curve from the Modulated Differential Scanning Calorimeter thermogram of synthetic cis-1,4-polyisoprene vulcanizate. Therefore, the results indicated that the essential oil extracts of Tulbaghia violacea have an effect as an alternative potential devulcanizing agents for conventional vulcanized synthetic cis-1,4-polyisoprene whether the diallyl disulphide compound is present or not in them.
- Full Text:
- Date Issued: 2020
- Authors: Gxakuma, Lutho
- Date: 2020
- Subjects: Plant extracts , Plant products -- South Africa Medicinal plants -- South Africa Plants -- Analysis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/49093 , vital:41600
- Description: Tulbaghia violacea is an indigenous plant commonly known as wild garlic, wilde knoffel in Afrikaans, isihaqa in Zulu or itswele lomlambo in Xhosa. Its leaves and bulbs are widely used as herbal remedies for various ailments and its medicinal uses include fever and colds, asthma, tuberculosis and stomach problems. Like all other members of the Alliacea family, Tulbaghia violacea produces a distinctive garlic-like odour when its leaves or rhizomes are damaged, resulting in the release of cysteine-derived sulphur compounds which include the oil-soluble organo-sulphur compounds and water-soluble cysteine derivatives. Chemically synthesized sulphur containing compounds have been reported to be effective devulcanizing agents and many industries prefer to perform devulcanization using them. Most commonly applied devulcanizing agents include disulphides, thiophenols and their zinc salts, and mercaptans which are mixed with the rubber scrap powder under specific reaction conditions. In this study, instead of performing devulcanization by using industrial synthesized sulphur containing compounds, the effectiveness of the extracts of organo-sulphur containing compounds from Tulbaghia violacea are evaluated as potential devulcanizing agents for synthetic cis-1,4-polyisoprene vulcanizates. This is a new, cheap and greener practice of rubber devulcanization. Diallyl disulphide, which is one of the organo-sulphur containing compounds present in Tulbaghia violacea, is the devulcanizing agent of interest to this study. The organo-sulphur containing compounds were extracted from the bulbs, roots and leaves of the plant using the soxhlet and ultrasonic bath extraction method. The solvent system used in the soxhlet extraction method was 2% of 2-propanol in n-hexane whereas in ultrasonic bath extraction method the solvent system used was 100% ethanol. An essential oil extract was obtained from the plant organs. The yield of the essential oil extracts obtained using the soxhlet extraction method was higher compared to the yield of the essential oil extracts obtained using the ultrasonic bath extraction method. According to the Fourier-Transform Infrared spectroscopy, the organo-sulphur containing compounds were present in the essential oil extracts of the plant. The essential oil extracts that were extracted using the soxhlet extraction method were chosen for further analysis. It was found out that the allyl sulphide and diallyl disulphide have the same retention time from the High Performance Liquid Chromatography (using a normal phase column). The Differential Scanning Calorimeter indicated that the allyl sulphide was not present in the essential oil extracts whereas the diallyl disulphide was present in the essential oil extract of the roots and leaves. The High Performance Liquid Chromatography was used to quantify the presence of the diallyl disulphide in the essential oil extract of roots and leaves. The quantity of diallyl disulphide was 23% in the dry mass of the essential oil extract of roots. In the essential oil extract of leaves the diallyl disulphide was very low concentrated and the High Performance Liquid Chromatography was less sensitive to detect it. According to the Thermogravimetric Analyser, it was found that the essential oil extracts begin to degrade at 120 °C and experience a multistage degradation. The softening temperature of the essential oil extracts was 60 °C from the Simultaneous Differential Scanning Calorimeter-Thermogravimetric Analyser. Conventional vulcanization of synthetic cis-1,4-polyisoprene was prepared with the vulcanization ingredients of zinc oxide, sulphur, stearic acid and N-tert-butyl-2-benzothiazole sulphenamide. The vulcanized synthetic cis-1,4-polyisoprene produced, under the heating temperature of 160 °C, was mixed with the essential oil extracts using the internal mixer at 60 °C and the two-roll mill. The overall torque, tan delta and the total crosslink density were the properties of interest of synthetic cis-1,4-polyisoprene vulcanizate in this study. The devulcanization temperature for the treated synthetic cis-1,4-polyisoprene vulcanizate with the essential oil extracts was optimized using the Dynamic Moving Die Rheometer and Dynamic Rubber Process Analyser. The amount of essential oil extracts at which they are effective devulcanizing agents for synthetic cis-1,4-polyisoprene vulcanizate was also optimized. During optimization a change on the latter mentioned properties of synthetic cis-1,4-polyisoprene vulcanizate was observed, indicating that the essential oil extracts have an effect as potential devulcanizing agents. The essential oil extracts increased the tan delta and reduced the overall torque, and total crosslink density of synthetic cis-1,4-polyisoprene vulcanizate as expected from devulcanizing agents. 200 °C was a preferable devulcanization temperature whereas essential oil extracts were effective as devulcanizing agent at 1.4%. However, the essential oil extracts influenced the overall torque and tan delta of synthetic cis-1,4-polyisoprene vulcanizate during the mixing process in the internal mixer at 60 °C, which was before heating at 200 °C. The essential oil extracts had a higher influence on the overall torque of synthetic cis-1,4-polyisoprene vulcanizate under heating at 200 °C whereas at 60 °C, during the mixing process, they had a higher influence on the tan delta of synthetic cis-1,4-polyisoprene vulcanizate. The essential oil extract of leaves had a higher influence on the overall torque whereas the essential oil extract of bulbs had a higher influence on the tan delta of synthetic cis-1,4-polyisoprene vulcanizate at 200 °C. The essential oil extract of roots shown a greater influence on the overall torque and tan delta of synthetic cis-1,4-polyisoprene vulcanizate at 60 °C during the mixing process. The effect of the essential oil extracts on the reversing heat capacity of synthetic cis-1,4-polyisoprene vulcanizate was also investigated using the Modulated Differential Scanning Calorimetry method. The essential oil extract of bulbs and roots influenced the reversing heat capacity of synthetic cis-1,4-polyisoprene vulcanizate by reducing it whereas the essential oil extract of leaves caused a temperature shift of the reversing heat capacity curve from the Modulated Differential Scanning Calorimeter thermogram of synthetic cis-1,4-polyisoprene vulcanizate. Therefore, the results indicated that the essential oil extracts of Tulbaghia violacea have an effect as an alternative potential devulcanizing agents for conventional vulcanized synthetic cis-1,4-polyisoprene whether the diallyl disulphide compound is present or not in them.
- Full Text:
- Date Issued: 2020
Analysis of the existence of the Phillips curve, Okun’s law and Taylor rule in the Zambian economy
- Authors: Chella, Siame Nampasa
- Date: 2020
- Subjects: Unemployment -- Effect of inflation -- Mathematical models --Zambia
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10948/49783 , vital:41800
- Description: The objective for this study was to explore the relationship between inflation and growth with an understanding of the effects of unemployment on growth. The primary objective of this paper was to investigate the existence of Phillips Curve, Okun’s Law, and Taylor Rule in Zambia on the basis that Zambia is a youthful economy, with a growing population, which is expected to temper with unemployment rates, as an increase in the supply of labour might be too high for the demand for jobs available. To be specific, the study aims at determining the relationship between inflation and growth and seeks to understand what policy measures have been undertaken to curb inflation and reduce unemployment in Zambia. To achieve this, a quantitative research was undertaken using the ARDL cointegration model in conjunction with sensitivity tests to cater for structural changes in the economy with 2007 standing as the break point, as well as paying attention to the fact that different policy regimes employed during the course of the data covered, that being, 1996 to 2017, would affect that rates of unemployment, inflation and growth of the country, across period under review. The study revealed that Zambia faces a Hybrid New Keynesian Phillips Curve during the period under study which is dominated by a mixture of both back-ward and forward-looking aspects of inflation. This specifically, paints the effects of inflation persistence as well future expectations of inflation on growth. Further, a cointegration relationship was established between unemployment and output, while Taylor principles were found not to apply to the Zambian economy, which have proved in other economies to be foundation blocks for good economic growth and as such significant to both fiscal and monetary policy authorities of the economy. The researcher therefore recommends that Zambian policy makers, that is, both the fiscal and the monetary authorities, work together in order to attain minimal and optimal levels of inflation to help achieve a conducive economic environment for the country.
- Full Text:
- Date Issued: 2020
- Authors: Chella, Siame Nampasa
- Date: 2020
- Subjects: Unemployment -- Effect of inflation -- Mathematical models --Zambia
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10948/49783 , vital:41800
- Description: The objective for this study was to explore the relationship between inflation and growth with an understanding of the effects of unemployment on growth. The primary objective of this paper was to investigate the existence of Phillips Curve, Okun’s Law, and Taylor Rule in Zambia on the basis that Zambia is a youthful economy, with a growing population, which is expected to temper with unemployment rates, as an increase in the supply of labour might be too high for the demand for jobs available. To be specific, the study aims at determining the relationship between inflation and growth and seeks to understand what policy measures have been undertaken to curb inflation and reduce unemployment in Zambia. To achieve this, a quantitative research was undertaken using the ARDL cointegration model in conjunction with sensitivity tests to cater for structural changes in the economy with 2007 standing as the break point, as well as paying attention to the fact that different policy regimes employed during the course of the data covered, that being, 1996 to 2017, would affect that rates of unemployment, inflation and growth of the country, across period under review. The study revealed that Zambia faces a Hybrid New Keynesian Phillips Curve during the period under study which is dominated by a mixture of both back-ward and forward-looking aspects of inflation. This specifically, paints the effects of inflation persistence as well future expectations of inflation on growth. Further, a cointegration relationship was established between unemployment and output, while Taylor principles were found not to apply to the Zambian economy, which have proved in other economies to be foundation blocks for good economic growth and as such significant to both fiscal and monetary policy authorities of the economy. The researcher therefore recommends that Zambian policy makers, that is, both the fiscal and the monetary authorities, work together in order to attain minimal and optimal levels of inflation to help achieve a conducive economic environment for the country.
- Full Text:
- Date Issued: 2020
Application of section 197 of the Labour Relations Act in an insourcing context
- Authors: Mahlati, Nomphelo Miliswa
- Date: 2020
- Subjects: Labor laws and legislation -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: http://hdl.handle.net/10948/47392 , vital:39974
- Description: The last two decades have been characterised by a phenomenal rise in the outsourcing of services to external service providers. The driver of this trend has been largely economic, since outsourcing offers more competitive price points for the same service at a comparable service level. Beyond the cost saving objective, the rationale for outsourcing has been to drive core strategy. However, with the economic slowdown, declining consumption and production are forcing entrepreneurs to change their way of thinking about the management of companies. Notably, in recent years there has been a small but a growing reversal of this trend where companies that have previously outsourced functions are being brought back in-house. One of the major concerns surrounding these changes of business strategies is the extent to which the employee rights are safeguarded.
- Full Text:
- Date Issued: 2020
- Authors: Mahlati, Nomphelo Miliswa
- Date: 2020
- Subjects: Labor laws and legislation -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: http://hdl.handle.net/10948/47392 , vital:39974
- Description: The last two decades have been characterised by a phenomenal rise in the outsourcing of services to external service providers. The driver of this trend has been largely economic, since outsourcing offers more competitive price points for the same service at a comparable service level. Beyond the cost saving objective, the rationale for outsourcing has been to drive core strategy. However, with the economic slowdown, declining consumption and production are forcing entrepreneurs to change their way of thinking about the management of companies. Notably, in recent years there has been a small but a growing reversal of this trend where companies that have previously outsourced functions are being brought back in-house. One of the major concerns surrounding these changes of business strategies is the extent to which the employee rights are safeguarded.
- Full Text:
- Date Issued: 2020
Applied phylogeography : mapping the genetic resource of Honeybush across the Cape Floristic Region
- Authors: Galuszynski, Nicholas C
- Date: 2020
- Subjects: Phylogeography -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/46771 , vital:39655
- Description: Aim: Honeybush tea is a herbal infusion made from members of the Cape Floristic Region (CFR) endemic Cyclopia Vent. Consting of 21 extant species, six are anthropogenically redistributed across the CFR for Honeybush cultivation. However, with no information regarding the distribution and levels of genetic diversity among wild Honeybush populations, anthropogenic translocation of cultivated genotypes may risk disrupting natural genetic diversity patterns. In this thesis, an applied phylogeographic approach is used to provide baseline insights into the spatial structuring of Honeybush genetic diversity. Location: The Cape Floristic Region (CFR), located along the southern Cape of South Africa. Methods: Spatial structuring of evolutionary lineages within Cyclopia are explored at a genus level using data generated from the combination of Anchored Hybrid Enrichment library preparation and high through put sequencing. A High Resolution Melt analysis (HRM) toolkit is then developed to screen haplotype variation across three non-coding chloroplast loci. This HRM toolkit coupled with haplotype confirmation Sanger sequencing is then applied to describe the spatial structuring of genetic diversity in wild populations for two Honeybush species (C. intermedia and C. subternata) and to compare genetic diversity among wild and cultivated populations of three Honeybush species (C. intermedia, C. subternata, and C. longifolia). A reanalysis of published phylogeographic data focusing on CFR plant taxa is used to test if phylogeographic breaks occur across the boundaries among adjacent Centers of Endemism (CoEs). Finally, the low-copy nuclear data set generated via AHE and high throughput sequencing is summarized. Results: Phylogeographic structuring was detected at the inter- and intraspecific levels in Cyclopia. The genus level analysis revealed a strong phylogenetic split between western CFR and eastern CFR endemic species in the nuclear and chloroplast genomes. At the intraspecific level, HRM proved to be a high throughput and accurate tool for haplotype detection, revealing phylogeographic structuring of genetic diversity in C.intermediaand C.subternata. This genetic diversity and structuring was not detected in cultivated Honeybush populations, which appear to have originated from a small number of founding individuals and have experienced a genetic bottleneck. Spatial structuring of genetic lineages is common among CFR plant taxa and the reanalysis of existing data found a significant trend for phylogeographic breaks tooccuracrosstheboundariesamongadjacentCoEs. Finally, over200000baseswere sequenced across 445 low-copy nuclear loci for 14 Cyclopia species. Conclusions: This thesis provides important baseline information on the spatial distribution of wild Honeybush genetic diversity. Phylogeographic structuring is present in wild Honeybush populations. This however is not accounted for in cultivated populations, which may place wild genetic diversity at risk of being disrupted if geneflow among wild and cultivated populations occurs. The results from this thesis should therefore be used to develop precautionary guidelines for the anthropogenic redistribution of Honeybush genetic material for cultivation. Furthermore, the novel insights into regional patterns of phylogeohraphic structuring of plant populations should encourage more efficient and hypothesis driven sampling designs in future phylogeographic work in the CFR. The high throughput sequence data generated in this thesis should transform Cyclopia to a model organism for the study of molecular evolution in the CFR.
- Full Text:
- Date Issued: 2020
- Authors: Galuszynski, Nicholas C
- Date: 2020
- Subjects: Phylogeography -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/46771 , vital:39655
- Description: Aim: Honeybush tea is a herbal infusion made from members of the Cape Floristic Region (CFR) endemic Cyclopia Vent. Consting of 21 extant species, six are anthropogenically redistributed across the CFR for Honeybush cultivation. However, with no information regarding the distribution and levels of genetic diversity among wild Honeybush populations, anthropogenic translocation of cultivated genotypes may risk disrupting natural genetic diversity patterns. In this thesis, an applied phylogeographic approach is used to provide baseline insights into the spatial structuring of Honeybush genetic diversity. Location: The Cape Floristic Region (CFR), located along the southern Cape of South Africa. Methods: Spatial structuring of evolutionary lineages within Cyclopia are explored at a genus level using data generated from the combination of Anchored Hybrid Enrichment library preparation and high through put sequencing. A High Resolution Melt analysis (HRM) toolkit is then developed to screen haplotype variation across three non-coding chloroplast loci. This HRM toolkit coupled with haplotype confirmation Sanger sequencing is then applied to describe the spatial structuring of genetic diversity in wild populations for two Honeybush species (C. intermedia and C. subternata) and to compare genetic diversity among wild and cultivated populations of three Honeybush species (C. intermedia, C. subternata, and C. longifolia). A reanalysis of published phylogeographic data focusing on CFR plant taxa is used to test if phylogeographic breaks occur across the boundaries among adjacent Centers of Endemism (CoEs). Finally, the low-copy nuclear data set generated via AHE and high throughput sequencing is summarized. Results: Phylogeographic structuring was detected at the inter- and intraspecific levels in Cyclopia. The genus level analysis revealed a strong phylogenetic split between western CFR and eastern CFR endemic species in the nuclear and chloroplast genomes. At the intraspecific level, HRM proved to be a high throughput and accurate tool for haplotype detection, revealing phylogeographic structuring of genetic diversity in C.intermediaand C.subternata. This genetic diversity and structuring was not detected in cultivated Honeybush populations, which appear to have originated from a small number of founding individuals and have experienced a genetic bottleneck. Spatial structuring of genetic lineages is common among CFR plant taxa and the reanalysis of existing data found a significant trend for phylogeographic breaks tooccuracrosstheboundariesamongadjacentCoEs. Finally, over200000baseswere sequenced across 445 low-copy nuclear loci for 14 Cyclopia species. Conclusions: This thesis provides important baseline information on the spatial distribution of wild Honeybush genetic diversity. Phylogeographic structuring is present in wild Honeybush populations. This however is not accounted for in cultivated populations, which may place wild genetic diversity at risk of being disrupted if geneflow among wild and cultivated populations occurs. The results from this thesis should therefore be used to develop precautionary guidelines for the anthropogenic redistribution of Honeybush genetic material for cultivation. Furthermore, the novel insights into regional patterns of phylogeohraphic structuring of plant populations should encourage more efficient and hypothesis driven sampling designs in future phylogeographic work in the CFR. The high throughput sequence data generated in this thesis should transform Cyclopia to a model organism for the study of molecular evolution in the CFR.
- Full Text:
- Date Issued: 2020
Applying blockchain technology to aspects of electronic health records in South Africa: lessons learnt
- Authors: Adlam, Ryno
- Date: 2020
- Subjects: Blockchains (Databases) , Database security Data protection Medical records -- Data processing
- Language: English
- Type: Thesis , Masters , MIT
- Identifier: http://hdl.handle.net/10948/45996 , vital:39405
- Description: The purpose of this study was to explore the applicability of blockchain technology as a viable alternative for the secure storage and distribution of electronic health records in a South African context. The adoption of electronic health records (EHRs) has grown over recent years. Electronic health records (EHRs) can be seen as electronic versions of patients’ medical history. EHRs promise benefits such as improving the quality of care, reducing medical errors, reducing costs, saving time, and enhancing the availability and sharing of medical records. Blockchain, in simple terms, could be seen as a distributed database controlled by a group of individuals. Blockchain technology differs from other distributed ledger technology by bundling unrelated data into blocks that are chained together in a linked-list manner, hence the name blockchain. Blockchain technology strives to provide desirable features, such as decentralization, immutability, audibility, and transparency. EHRs are traditionally constructed with a cloud-based infrastructure to promote the storing and distribution of medical records. These medical records are commonly stored in a centralized architecture, such as a relational database. The centralized architecture employed by EHRs may present a single point of failure. These kinds of failures may lead to data-breaches. The cloud-based infrastructure is effective and efficient from an availability standpoint. The increased availability of electronic health records has brought forth challenges related to the security and privacy of the patient’s medical records. The sensitive nature of EHRs attracts the attention of cyber-criminals. There has been a rise in the number of data breaches related to electronic health records. The traditional infrastructure used by electronic health records can no longer ensure the privacy and security of patient’s medical records. To determine whether blockchain is a viable alternative to these approaches, the main objective of this study was to compile a technical report on the applicability of aspects of blockchain technology to the secure storage and distribution of electronic health records. The study first conducted a literature review to gather background on the current state of electronic health records and blockchain technology. The results of the literature review were used to compile an initial report. Experiments were conducted with various aspects of blockchain technology to build a technical baseline and to ultimately validate the initial report. The insights gained from the experiments served to refine the initial report into a final technical report. The final deliverable of this study was to devise a technical report. The technical report serves as a generalized overview of the applicability of blockchain technology as a secure storage and distribution mechanism for electronic health records. The main topics covered by the technical report to outline the applicability of blockchain technology to EHRs are as follows: authentication, authorization, audit log, storage and transactions. The insights gained from the study illustrate that permissioned blockchain technology can enhance the traditional AAA security scheme employed by traditional EHRs. The AAA security scheme entails the use of certificate-based authentication and attributebased access control for authorization. Audit logs can be stored in a semi-decentralized architecture that can enhance the security and privacy of audit logs. Using blockchain technology for storing electronic health records might not be a viable alternative to traditional EHRs architecture. Blockchain technology violates certain privacy regulations as information is stored in a permanent manner. Furthermore, blockchain technology is not optimized for dealing with large volumes of data. However, blockchain technology could be used to store a cryptographic hash of electronic health records to ensure the integrity of records. Permissioned blockchain technology can enhance the EHRs transaction process by transacting health records in a peer-to-peer infrastructure. In doing so, the above-mentioned AAA security scheme can enhance the security, confidentiality, and integrity of electronic health records shared across organizational bounds.
- Full Text:
- Date Issued: 2020
- Authors: Adlam, Ryno
- Date: 2020
- Subjects: Blockchains (Databases) , Database security Data protection Medical records -- Data processing
- Language: English
- Type: Thesis , Masters , MIT
- Identifier: http://hdl.handle.net/10948/45996 , vital:39405
- Description: The purpose of this study was to explore the applicability of blockchain technology as a viable alternative for the secure storage and distribution of electronic health records in a South African context. The adoption of electronic health records (EHRs) has grown over recent years. Electronic health records (EHRs) can be seen as electronic versions of patients’ medical history. EHRs promise benefits such as improving the quality of care, reducing medical errors, reducing costs, saving time, and enhancing the availability and sharing of medical records. Blockchain, in simple terms, could be seen as a distributed database controlled by a group of individuals. Blockchain technology differs from other distributed ledger technology by bundling unrelated data into blocks that are chained together in a linked-list manner, hence the name blockchain. Blockchain technology strives to provide desirable features, such as decentralization, immutability, audibility, and transparency. EHRs are traditionally constructed with a cloud-based infrastructure to promote the storing and distribution of medical records. These medical records are commonly stored in a centralized architecture, such as a relational database. The centralized architecture employed by EHRs may present a single point of failure. These kinds of failures may lead to data-breaches. The cloud-based infrastructure is effective and efficient from an availability standpoint. The increased availability of electronic health records has brought forth challenges related to the security and privacy of the patient’s medical records. The sensitive nature of EHRs attracts the attention of cyber-criminals. There has been a rise in the number of data breaches related to electronic health records. The traditional infrastructure used by electronic health records can no longer ensure the privacy and security of patient’s medical records. To determine whether blockchain is a viable alternative to these approaches, the main objective of this study was to compile a technical report on the applicability of aspects of blockchain technology to the secure storage and distribution of electronic health records. The study first conducted a literature review to gather background on the current state of electronic health records and blockchain technology. The results of the literature review were used to compile an initial report. Experiments were conducted with various aspects of blockchain technology to build a technical baseline and to ultimately validate the initial report. The insights gained from the experiments served to refine the initial report into a final technical report. The final deliverable of this study was to devise a technical report. The technical report serves as a generalized overview of the applicability of blockchain technology as a secure storage and distribution mechanism for electronic health records. The main topics covered by the technical report to outline the applicability of blockchain technology to EHRs are as follows: authentication, authorization, audit log, storage and transactions. The insights gained from the study illustrate that permissioned blockchain technology can enhance the traditional AAA security scheme employed by traditional EHRs. The AAA security scheme entails the use of certificate-based authentication and attributebased access control for authorization. Audit logs can be stored in a semi-decentralized architecture that can enhance the security and privacy of audit logs. Using blockchain technology for storing electronic health records might not be a viable alternative to traditional EHRs architecture. Blockchain technology violates certain privacy regulations as information is stored in a permanent manner. Furthermore, blockchain technology is not optimized for dealing with large volumes of data. However, blockchain technology could be used to store a cryptographic hash of electronic health records to ensure the integrity of records. Permissioned blockchain technology can enhance the EHRs transaction process by transacting health records in a peer-to-peer infrastructure. In doing so, the above-mentioned AAA security scheme can enhance the security, confidentiality, and integrity of electronic health records shared across organizational bounds.
- Full Text:
- Date Issued: 2020
Applying high-resolution remote sensing to quantify baboon damage at a sub-compartment level in pine stands in the Mpumalanga escarpment region of South Africa
- Authors: Ferreira, Regardt
- Date: 2020
- Subjects: Environmental sciences -- Remote sensing , Geographic information systems Remote sensing
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/49082 , vital:41599
- Description: Managing risk in intensively managed monoculture plantation forests is an essential task to ensure sustainable yield and a continuous flow of forest products. However, since risks can be either biotic or abiotic, not all of them have a predictable pattern of spread, which can cause severe losses if management does not have the chance to implement mitigation action. Monitoring the change in forest health is vital as this provides the opportunity for preventative management and quantifies the amount of damage that management has to deal with. To provide this window of opportunity for appropriate action, constant monitoring is required. Until recently, forest health was measured through field surveys which provided adequate data. This procedure, however, is time consuming. Remote sensing has become very popular as a monitoring tool, due to its ability to provide assessment data in a fraction of the time. In this study, baboon damage in plantations along the Mpumalanga escarpment area of South Africa was monitored using remote sensing methods. While there are many methods of forest health monitoring using remote sensing, some approaches are less suitable as they either monitor damage caused at a plantation level, use lower spatial resolution (>10m) datasets or map damage using one available time period. The purpose of this study was first to establish the impact of baboon damage through time, using Sentinel-2 satellite imagery with all vegetation indices available, and the Extreme Gradient Boosting (XGboost) algorithm. The second part focused on analysing the damage at a tree level using PlanetScope imagery using a deep Learning approach. Overall, the study found that the use of Sentinel-2 data and PlanetScope data could accurately distinguish between the varying severity of baboon damage, achieving an accuracy of 95% and 82%. The processing time of the deep learning Artificial Neural Network (ANN) was greatly affected by the number of hidden layers and neurons used. Implementation of techniques used in this study has the potential to improve the accuracy of forest health monitoring in compartment forestry in South Africa.
- Full Text:
- Date Issued: 2020
- Authors: Ferreira, Regardt
- Date: 2020
- Subjects: Environmental sciences -- Remote sensing , Geographic information systems Remote sensing
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/49082 , vital:41599
- Description: Managing risk in intensively managed monoculture plantation forests is an essential task to ensure sustainable yield and a continuous flow of forest products. However, since risks can be either biotic or abiotic, not all of them have a predictable pattern of spread, which can cause severe losses if management does not have the chance to implement mitigation action. Monitoring the change in forest health is vital as this provides the opportunity for preventative management and quantifies the amount of damage that management has to deal with. To provide this window of opportunity for appropriate action, constant monitoring is required. Until recently, forest health was measured through field surveys which provided adequate data. This procedure, however, is time consuming. Remote sensing has become very popular as a monitoring tool, due to its ability to provide assessment data in a fraction of the time. In this study, baboon damage in plantations along the Mpumalanga escarpment area of South Africa was monitored using remote sensing methods. While there are many methods of forest health monitoring using remote sensing, some approaches are less suitable as they either monitor damage caused at a plantation level, use lower spatial resolution (>10m) datasets or map damage using one available time period. The purpose of this study was first to establish the impact of baboon damage through time, using Sentinel-2 satellite imagery with all vegetation indices available, and the Extreme Gradient Boosting (XGboost) algorithm. The second part focused on analysing the damage at a tree level using PlanetScope imagery using a deep Learning approach. Overall, the study found that the use of Sentinel-2 data and PlanetScope data could accurately distinguish between the varying severity of baboon damage, achieving an accuracy of 95% and 82%. The processing time of the deep learning Artificial Neural Network (ANN) was greatly affected by the number of hidden layers and neurons used. Implementation of techniques used in this study has the potential to improve the accuracy of forest health monitoring in compartment forestry in South Africa.
- Full Text:
- Date Issued: 2020