Main thesis title 2021: A framework for a waterfront development in Nelson Mandela Bay
- Sethosa, Thandisizwe Theophilus
- Authors: Sethosa, Thandisizwe Theophilus
- Date: 2021-04
- Subjects: Gqeberha (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master' theses , text
- Identifier: http://hdl.handle.net/10948/52957 , vital:44902
- Description: Internationally, waterfront developments have become major tourist attractions and added to a city's infrastructure. This study seeks to traverse available literature to develop a conceptual framework for Waterfront Development in Nelson Mandela Bay. A framework is a systematic arrangement of ideas that are used to establish an understanding of ideas and principles that are relevant to a research study. Following the comprehensive analysis of literature that has been carried out globally, a conceptual framework was adopted as a blueprint for successful Waterfront Developments from the Port of Adelaide in South Australia. The framework essentially comprises one dependent factor, namely A successful Waterfront Development. This factor was expected to be influenced positively by the following independent factors, namely Functionality, Accessibility, Natural Environment and Culture, History and Memory. This research pursued a positivistic approach using quantitative methods of analysis. Accordingly, the researcher tested a conceptual model through the use of an online survey and statistical analysis. The hypothesised Waterfront Development Model for Nelson Mandela Bay was evaluated statistically. This includes a detailed process of the assessment of the factors via Exploratory Factor Analysis (EFA). The EFA produced new factors and rearranged the items allocated to different factors in accordance to best statistical fit. The study's questionnaire was distributed to the residents of Nelson Mandela Bay and was completed by a sample of 202 residents. The study sought to identify relevant factors to inform management on how to drive a successful waterfront development imperative in the city. The factor ‘Critical Success Factor’ in the hypothesised model, through the EFA process produced four additional factors namely, ‘Unique NMB Identity’, ‘Public-Private Partnership’, ‘Development Time frames’ and ‘Ownership Structure’. The factor ‘Functionality ‘in the hypothesised model, through the EFA process produced three additional factors namely, ‘Leisure Activities’, ‘Port Activities’ and ‘Residential Potential. , Thesis (MBA) -- Faculty of Business and Economic Sciences, NMU Business School, 2021
- Full Text: false
- Date Issued: 2021-04
- Authors: Sethosa, Thandisizwe Theophilus
- Date: 2021-04
- Subjects: Gqeberha (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master' theses , text
- Identifier: http://hdl.handle.net/10948/52957 , vital:44902
- Description: Internationally, waterfront developments have become major tourist attractions and added to a city's infrastructure. This study seeks to traverse available literature to develop a conceptual framework for Waterfront Development in Nelson Mandela Bay. A framework is a systematic arrangement of ideas that are used to establish an understanding of ideas and principles that are relevant to a research study. Following the comprehensive analysis of literature that has been carried out globally, a conceptual framework was adopted as a blueprint for successful Waterfront Developments from the Port of Adelaide in South Australia. The framework essentially comprises one dependent factor, namely A successful Waterfront Development. This factor was expected to be influenced positively by the following independent factors, namely Functionality, Accessibility, Natural Environment and Culture, History and Memory. This research pursued a positivistic approach using quantitative methods of analysis. Accordingly, the researcher tested a conceptual model through the use of an online survey and statistical analysis. The hypothesised Waterfront Development Model for Nelson Mandela Bay was evaluated statistically. This includes a detailed process of the assessment of the factors via Exploratory Factor Analysis (EFA). The EFA produced new factors and rearranged the items allocated to different factors in accordance to best statistical fit. The study's questionnaire was distributed to the residents of Nelson Mandela Bay and was completed by a sample of 202 residents. The study sought to identify relevant factors to inform management on how to drive a successful waterfront development imperative in the city. The factor ‘Critical Success Factor’ in the hypothesised model, through the EFA process produced four additional factors namely, ‘Unique NMB Identity’, ‘Public-Private Partnership’, ‘Development Time frames’ and ‘Ownership Structure’. The factor ‘Functionality ‘in the hypothesised model, through the EFA process produced three additional factors namely, ‘Leisure Activities’, ‘Port Activities’ and ‘Residential Potential. , Thesis (MBA) -- Faculty of Business and Economic Sciences, NMU Business School, 2021
- Full Text: false
- Date Issued: 2021-04
The effectiveness of Bhisho child and youth care Centre youth in conflict with the law rehabilitation programs
- Authors: Mzili, Hlumela
- Date: 2021-04
- Subjects: Juvenile delinquency
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/23731 , vital:58619
- Description: Youth in conflict with the law is seemingly becoming a significant problem in South Africa, especially in the Eastern Cape where youth engage in risk-taking activities, such as anti-social behaviour and criminal acts. This study builds on factors contributing to youth delinquency such as negative behaviours of parents, dysfunctional families, high crime rate in communities, poor self-concept, low literacy level, poor socio-economic status and no sense of belonging. Against this backdrop there are programmes put in place as a form of rehabilitation for the youth in an effort to eliminate from amongst them, recidivism that conflicts with the law. However, little importance has been given to the challenges faced when implementing such programmes, such as illiteracy, rebellion, deviance and lack of resilience among youth. This context informed the study’s aim to explore the effectiveness of the rehabilitation programmes at the Bhisho Child and Youth Care Centre. To achieve this aim, the study employed the qualitative research approach to explore the rehabilitation programmes. Data was collected through 20 semi-structured interviews with purposively sampled participants (children/youth and personnel from the centre) ranging from those who perpetrated the heavier crimes to those who perpetrated the least crimes. Collected data was analysed through thematic analysis whereby tape recordings were transcribed, sorted and interpreted under themes that show common cause or commonalities among the research participants. The main findings show that the programmes offered to the youth are effective and play an important role in curbing their criminal behaviour. The acts of the study recommend that the personnel at the Bhisho Child and Youth Care Centre be equipped with more developmental services which can enable them to produce more effectiveness to the programmes offered by the centre. , Thesis (MSoc) -- Faculty of Social Sciences and Humanities, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Mzili, Hlumela
- Date: 2021-04
- Subjects: Juvenile delinquency
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/23731 , vital:58619
- Description: Youth in conflict with the law is seemingly becoming a significant problem in South Africa, especially in the Eastern Cape where youth engage in risk-taking activities, such as anti-social behaviour and criminal acts. This study builds on factors contributing to youth delinquency such as negative behaviours of parents, dysfunctional families, high crime rate in communities, poor self-concept, low literacy level, poor socio-economic status and no sense of belonging. Against this backdrop there are programmes put in place as a form of rehabilitation for the youth in an effort to eliminate from amongst them, recidivism that conflicts with the law. However, little importance has been given to the challenges faced when implementing such programmes, such as illiteracy, rebellion, deviance and lack of resilience among youth. This context informed the study’s aim to explore the effectiveness of the rehabilitation programmes at the Bhisho Child and Youth Care Centre. To achieve this aim, the study employed the qualitative research approach to explore the rehabilitation programmes. Data was collected through 20 semi-structured interviews with purposively sampled participants (children/youth and personnel from the centre) ranging from those who perpetrated the heavier crimes to those who perpetrated the least crimes. Collected data was analysed through thematic analysis whereby tape recordings were transcribed, sorted and interpreted under themes that show common cause or commonalities among the research participants. The main findings show that the programmes offered to the youth are effective and play an important role in curbing their criminal behaviour. The acts of the study recommend that the personnel at the Bhisho Child and Youth Care Centre be equipped with more developmental services which can enable them to produce more effectiveness to the programmes offered by the centre. , Thesis (MSoc) -- Faculty of Social Sciences and Humanities, 2021
- Full Text:
- Date Issued: 2021-04
An investigation into the use of a consumer incentive to encourage recycling in South Africa
- Authors: Conway, John Charles
- Date: 2021-04
- Subjects: Recycling (Waste, etc.) -- Economic aspects , Consumption (Economics) -- South Africa , Consumer behavior
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/51096 , vital:43208
- Description: The focus of this study is the factors that influence recycling behaviours, particularly whether incentives are likely to change consumers’ recycling behaviours in South Africa. Africa is said to become the most polluted continent within a few decades. Three of the largest metropoles in South African are likely to run out of landfill space within the next ten years. Waste streams provide considerable opportunity if waste can be safely collected and either reused, recycled, or recovered, but extracting value from the waste streams is costly and difficult. Consumers need to separate waste at source to improve the efficacy of the recycling stream, yet South Africans do not separate waste at source as a norm. The question that arises then is would an incentive improve South Africans’ willingness to recycle? This study tried to determine if incentives are likely to change consumers’ recycling behaviours in South Africa. It explored the relationship between factors that influence recycling behaviours grounded in Taylor and Todd's (1995) extension of Ajzen's (1991) Theory Of Planned Behaviour. A quantitative survey design, using both online and face to face questionnaires, was used to collect data from a cross section of randomly selected consumers. The research determines that the call to address waste management infrastructure and facilities, is indeed correct. It further confirms previous research findings that an incentive alone is not enough to change recycling behaviours as it will not negate other environmental factors. Lower income groups are more conscientious about recycling and may be enticed to participate in the recycling industry through an incentive to improve their income. , Thesis (MBA) -- Faculty of Business and Economic Sciences, Business Administration, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Conway, John Charles
- Date: 2021-04
- Subjects: Recycling (Waste, etc.) -- Economic aspects , Consumption (Economics) -- South Africa , Consumer behavior
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/51096 , vital:43208
- Description: The focus of this study is the factors that influence recycling behaviours, particularly whether incentives are likely to change consumers’ recycling behaviours in South Africa. Africa is said to become the most polluted continent within a few decades. Three of the largest metropoles in South African are likely to run out of landfill space within the next ten years. Waste streams provide considerable opportunity if waste can be safely collected and either reused, recycled, or recovered, but extracting value from the waste streams is costly and difficult. Consumers need to separate waste at source to improve the efficacy of the recycling stream, yet South Africans do not separate waste at source as a norm. The question that arises then is would an incentive improve South Africans’ willingness to recycle? This study tried to determine if incentives are likely to change consumers’ recycling behaviours in South Africa. It explored the relationship between factors that influence recycling behaviours grounded in Taylor and Todd's (1995) extension of Ajzen's (1991) Theory Of Planned Behaviour. A quantitative survey design, using both online and face to face questionnaires, was used to collect data from a cross section of randomly selected consumers. The research determines that the call to address waste management infrastructure and facilities, is indeed correct. It further confirms previous research findings that an incentive alone is not enough to change recycling behaviours as it will not negate other environmental factors. Lower income groups are more conscientious about recycling and may be enticed to participate in the recycling industry through an incentive to improve their income. , Thesis (MBA) -- Faculty of Business and Economic Sciences, Business Administration, 2021
- Full Text:
- Date Issued: 2021-04
University students’ perceptions of the influence of cannabis use on mental health
- Ramodumo, Itumeleng Adolphina
- Authors: Ramodumo, Itumeleng Adolphina
- Date: 2021-04
- Subjects: Mental health -- Education (Higher) , Marijuana -- Physiological effect , Cannabis -- Psychological aspects
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/51611 , vital:43322
- Description: This study explored university students’ perceptions of cannabis use on mental health at a higher education institution (HEI). Cannabis is described as the most commonly used drug by youth, especially, those who are in tertiary institutions (Allen & Holder, 2014; Arria, Caldeira, Bugbee, Vincent & O’Grady, 2015). The use of cannabis has both negative and positive effects; this is evident in different areas of human functioning. Cannabis usage has been debated upon in courts, regarding its legalisation and decriminalisation, and on the 18th of September 2018, the South African High Court legalised cannabis for personal use. A qualitative study with an explorative- descriptive design was used to give a broader exploration of university students’ perceptions of the influence of cannabis on mental health. The study was conducted at an HEI in the Nelson Mandela Bay and purposive sampling was used to select 15 participants for the study. Data was collected using focused group interviews, following the granting of permission by the Nelson Mandela University Research Ethics Committee. The collected data was analysed and interpreted using thematic analysis. The research findings indicated both positive and negative influences of cannabis use on mental health. Most participants who expressed positive effects are pervious cannabis users, whereas, most participants with negative perspectives of cannabis use on mental health are non- cannabis users. The findings revealed that participants perceived that the quantity of cannabis smoked determined whether there was a positive or negative effect on mental health, that is, large doses of cannabis had negative effects. The research findings also revealed that the legalisation of cannabis is very likely to increase its use, and the precautionary measures users take to avoid the substance’s negative effects on mental health. The Cognitive Behavioural Theory was used as the lens to better understand how students perceive cannabis use and its influence on mental health. , Thesis (MA) -- Faculty of Health Sciences, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Ramodumo, Itumeleng Adolphina
- Date: 2021-04
- Subjects: Mental health -- Education (Higher) , Marijuana -- Physiological effect , Cannabis -- Psychological aspects
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/51611 , vital:43322
- Description: This study explored university students’ perceptions of cannabis use on mental health at a higher education institution (HEI). Cannabis is described as the most commonly used drug by youth, especially, those who are in tertiary institutions (Allen & Holder, 2014; Arria, Caldeira, Bugbee, Vincent & O’Grady, 2015). The use of cannabis has both negative and positive effects; this is evident in different areas of human functioning. Cannabis usage has been debated upon in courts, regarding its legalisation and decriminalisation, and on the 18th of September 2018, the South African High Court legalised cannabis for personal use. A qualitative study with an explorative- descriptive design was used to give a broader exploration of university students’ perceptions of the influence of cannabis on mental health. The study was conducted at an HEI in the Nelson Mandela Bay and purposive sampling was used to select 15 participants for the study. Data was collected using focused group interviews, following the granting of permission by the Nelson Mandela University Research Ethics Committee. The collected data was analysed and interpreted using thematic analysis. The research findings indicated both positive and negative influences of cannabis use on mental health. Most participants who expressed positive effects are pervious cannabis users, whereas, most participants with negative perspectives of cannabis use on mental health are non- cannabis users. The findings revealed that participants perceived that the quantity of cannabis smoked determined whether there was a positive or negative effect on mental health, that is, large doses of cannabis had negative effects. The research findings also revealed that the legalisation of cannabis is very likely to increase its use, and the precautionary measures users take to avoid the substance’s negative effects on mental health. The Cognitive Behavioural Theory was used as the lens to better understand how students perceive cannabis use and its influence on mental health. , Thesis (MA) -- Faculty of Health Sciences, 2021
- Full Text:
- Date Issued: 2021-04
Exploring how Grade 9 Physical Science teachers mediate learning of the topic of chemical changes
- Likando, Orrice Munukayumbwa
- Authors: Likando, Orrice Munukayumbwa
- Date: 2021-04
- Subjects: Science -- Study and teaching (Secondary) -- Namibia , Chemistry -- Study and teaching (Secondary) -- Namibia , Culturally relevant pedagogy , Pedagogical content knowledge , Prior learning -- Namibia
- Language: English
- Type: thesis , text , Masters , MEd
- Identifier: http://hdl.handle.net/10962/177918 , vital:42890
- Description: The examiners’ reports for 2013-2018 indicated that learners consistently perform poorly in questions based on chemical changes. My assumption is that the reason why learners are challenged with understanding the topic of chemical changes could be due to the way this topic is taught. It is against this background that this study explored how grade 9 Physical Science teachers mediated learning of the topic of chemical changes. The study is underpinned by an interpretive paradigm. Within the interpretive paradigm, a qualitative case study research design was employed. It was conducted at two different schools in the Otjozondjupa region with two Physical Science teachers. Data were collected using semi-structured interviews, lesson observations, stimulated recall interviews, and teachers’ reflections. The study is informed by Vygotsky’s socio-cultural theory together with Shulman’s pedagogical content knowledge as the theoretical frameworks. A thematic approach to data analysis was adopted. That is, qualitative data were analysed inductively to come up with sub-themes to form themes. Moreover, validation and trustworthiness were completed through data triangulation, member checking, and watching videotaped lessons with the participants. The findings of this study revealed that the topic of chemical changes has many examples which can be used during mediation. Teachers seemed to be aware of integrating learners’ experiences into their lessons. Furthermore, they were aware that they should improvise resources during mediation of learning. In contrast, during lesson observations, the findings revealed an imbalance between this awareness and the actual knowledge of using easily accessible materials, and the elicitation and integration of prior knowledge throughout the science lessons. Moreover, hands-on practical activities were lacking in the mediation process and instead, traditional methods of teaching tended to dominate. Nonetheless, teachers’ reflections influenced them to analyse and strengthen their lessons. Thus, the study recommends that there is a need for teachers to have mentorships and platforms which can expose them to the knowledge of different types of easily accessible materials. This might strengthen their PCK. Teachers are also encouraged to do some reflections after very lesson as these have a potential to influence their pedagogical practices. , Thesis (MEd) -- Faculty of Education, Education, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Likando, Orrice Munukayumbwa
- Date: 2021-04
- Subjects: Science -- Study and teaching (Secondary) -- Namibia , Chemistry -- Study and teaching (Secondary) -- Namibia , Culturally relevant pedagogy , Pedagogical content knowledge , Prior learning -- Namibia
- Language: English
- Type: thesis , text , Masters , MEd
- Identifier: http://hdl.handle.net/10962/177918 , vital:42890
- Description: The examiners’ reports for 2013-2018 indicated that learners consistently perform poorly in questions based on chemical changes. My assumption is that the reason why learners are challenged with understanding the topic of chemical changes could be due to the way this topic is taught. It is against this background that this study explored how grade 9 Physical Science teachers mediated learning of the topic of chemical changes. The study is underpinned by an interpretive paradigm. Within the interpretive paradigm, a qualitative case study research design was employed. It was conducted at two different schools in the Otjozondjupa region with two Physical Science teachers. Data were collected using semi-structured interviews, lesson observations, stimulated recall interviews, and teachers’ reflections. The study is informed by Vygotsky’s socio-cultural theory together with Shulman’s pedagogical content knowledge as the theoretical frameworks. A thematic approach to data analysis was adopted. That is, qualitative data were analysed inductively to come up with sub-themes to form themes. Moreover, validation and trustworthiness were completed through data triangulation, member checking, and watching videotaped lessons with the participants. The findings of this study revealed that the topic of chemical changes has many examples which can be used during mediation. Teachers seemed to be aware of integrating learners’ experiences into their lessons. Furthermore, they were aware that they should improvise resources during mediation of learning. In contrast, during lesson observations, the findings revealed an imbalance between this awareness and the actual knowledge of using easily accessible materials, and the elicitation and integration of prior knowledge throughout the science lessons. Moreover, hands-on practical activities were lacking in the mediation process and instead, traditional methods of teaching tended to dominate. Nonetheless, teachers’ reflections influenced them to analyse and strengthen their lessons. Thus, the study recommends that there is a need for teachers to have mentorships and platforms which can expose them to the knowledge of different types of easily accessible materials. This might strengthen their PCK. Teachers are also encouraged to do some reflections after very lesson as these have a potential to influence their pedagogical practices. , Thesis (MEd) -- Faculty of Education, Education, 2021
- Full Text:
- Date Issued: 2021-04
Ecosexual digital war machines: minoritarian environmental desires in the age of new media
- Authors: Weideman, Lisa
- Date: 2021-04
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/54828 , vital:47915
- Description: Today the (Transnational) State Apparatuses of neoliberal capitalism, ranging from educational institutions to mass media and financial institutions, have effectively created and channelled desires towards consumerism, predicated on resource-extractive practices, within the context of what Gilles Deleuze calls societies of control. This control has also intensified in the digital era, particularly through Internet-based technologies which provide increasingly efficient platforms for the escalation of commodification – ironically, despite the reality of ecological crisis being precipitated by the related extractive practices to the point where it now threatens the continued existence of life on earth. , Thesis (MA) -- Faculty of Humanities, School of Language, Media and Communication, 2021
- Full Text: false
- Date Issued: 2021-04
- Authors: Weideman, Lisa
- Date: 2021-04
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/54828 , vital:47915
- Description: Today the (Transnational) State Apparatuses of neoliberal capitalism, ranging from educational institutions to mass media and financial institutions, have effectively created and channelled desires towards consumerism, predicated on resource-extractive practices, within the context of what Gilles Deleuze calls societies of control. This control has also intensified in the digital era, particularly through Internet-based technologies which provide increasingly efficient platforms for the escalation of commodification – ironically, despite the reality of ecological crisis being precipitated by the related extractive practices to the point where it now threatens the continued existence of life on earth. , Thesis (MA) -- Faculty of Humanities, School of Language, Media and Communication, 2021
- Full Text: false
- Date Issued: 2021-04
A study of the airflow on the windward slope of a transverse dune in the Alexandria coastal dunefield
- Authors: Burkinshaw, Jennifer Ruth
- Date: 2021-04
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/52734 , vital:43883
- Description: Our understanding of the evolution of dune morphology has been hampered by a lack of empirical observations of airflow behaviour over dune forms. Sand dunes intrude into the atmospheric boundary layer and convergence of streamlines results in an acceleration of airflow up the windward slopes of dunes. This study examines the airflow structure and corresponding bedform development on the windward slope of a 7 m high transverse dune on the edge of the Alexandria coastal dunefield, Algoa Bay, South Africa. The Alexandria dunefield is subjected to a trimodal wind regime, consisting of the dominant south-westerly which blows all year round, summer easterlies and winter northwesterlies. The morphology of the study dune, Dune13, is controlled by the easterlies and north-westerlies, and reverses seasonally with respect to these two winds. Seven section lines 30 m apart and normal to the dune crest were surveyed regularly over the period of a year to monitor the reversal process. Three detailed topographic surveys were also done during this period. Airflow behaviour was monitored during the year. Wind speed profiles on the windward slope of the dune were measured using 4 to 5 vertical arrays of anemometers positioned from the base of the dune to the crest on a 1 selected section line. Usually 4 to 5 anemometers were deployed in each vertical array, from a height of 6 to 10 cm above the surface, up to a height of 150 cm above the surface. Initially 8 microanemometers were available; ultimately 28 anemometers were run simultaneously. An independent weather station at an elevation of 6 m recorded the unaccelerated flow. Local gradient measurements and erosion and deposition rates were recorded along selected section lines. Strong summer easterly winds (14 m/sec at 1.4 m above the dune crest) were measured on a dune slope in the process of being transformed from a slipface to a stoss slope. The following winter, light north-westerly winds (typically B m/sec at 1.6 m above the dune crest) were measured on the new windward slope already reversed by the prevailing winter wind. Airflow data confirm the compression of airflow against the windward slope resulting in a non-logarithmic wind speed profile. Compression results in an increased shear velocity within 30 cm of the dune surface, and the dune slope is eroded. Higher up in the wind speed profile, shear velocity decreases to 0.1 m/sec. It is not known at what height the wind speed profile recovers from the intrusion of the dune into the boundary layer. High values of shear velocity (1.6 m/sec) above the rounded crestal area of the dune record the recovery of the wind speed profile from flow divergence, which is a response to the rapid reduction of dune gradient and is accompanied by deposition of sand in this region. 2 The erosion pin data act as a simple and sensitive test for changes in gradient, reflecting the dune's response to changes in the airflow regime. The shape of the dune plays a major role in determining the extent of the compression and the distribution of shear velocity up the slope. Increased shear velocity is experienced on that part of the slope which is nonaerodynamic with respect to the prevailing wind. Under unidirectional conditions, feedback between flow and form results ultimately in a slope with a curvature such that shear velocity increases systematically upslope. The survey data and erosion pin data record the reversal process as the dune achieves a new steady state during each wind season. The existence of a non-logarithmic wind speed profile makes it difficult to know what relevant measure of shear velocity is to be used in sand transport equations. Future work should include wind speed measurements within 10 cm of the surface. An ideal study modelling aeolian bedform development would utilise wind tunnel measurements, combined with field measurements such as obtained in this study, for comparison with numerical modelling. The study needs to be extended to 3-dimensional airflow measurements. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Burkinshaw, Jennifer Ruth
- Date: 2021-04
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/52734 , vital:43883
- Description: Our understanding of the evolution of dune morphology has been hampered by a lack of empirical observations of airflow behaviour over dune forms. Sand dunes intrude into the atmospheric boundary layer and convergence of streamlines results in an acceleration of airflow up the windward slopes of dunes. This study examines the airflow structure and corresponding bedform development on the windward slope of a 7 m high transverse dune on the edge of the Alexandria coastal dunefield, Algoa Bay, South Africa. The Alexandria dunefield is subjected to a trimodal wind regime, consisting of the dominant south-westerly which blows all year round, summer easterlies and winter northwesterlies. The morphology of the study dune, Dune13, is controlled by the easterlies and north-westerlies, and reverses seasonally with respect to these two winds. Seven section lines 30 m apart and normal to the dune crest were surveyed regularly over the period of a year to monitor the reversal process. Three detailed topographic surveys were also done during this period. Airflow behaviour was monitored during the year. Wind speed profiles on the windward slope of the dune were measured using 4 to 5 vertical arrays of anemometers positioned from the base of the dune to the crest on a 1 selected section line. Usually 4 to 5 anemometers were deployed in each vertical array, from a height of 6 to 10 cm above the surface, up to a height of 150 cm above the surface. Initially 8 microanemometers were available; ultimately 28 anemometers were run simultaneously. An independent weather station at an elevation of 6 m recorded the unaccelerated flow. Local gradient measurements and erosion and deposition rates were recorded along selected section lines. Strong summer easterly winds (14 m/sec at 1.4 m above the dune crest) were measured on a dune slope in the process of being transformed from a slipface to a stoss slope. The following winter, light north-westerly winds (typically B m/sec at 1.6 m above the dune crest) were measured on the new windward slope already reversed by the prevailing winter wind. Airflow data confirm the compression of airflow against the windward slope resulting in a non-logarithmic wind speed profile. Compression results in an increased shear velocity within 30 cm of the dune surface, and the dune slope is eroded. Higher up in the wind speed profile, shear velocity decreases to 0.1 m/sec. It is not known at what height the wind speed profile recovers from the intrusion of the dune into the boundary layer. High values of shear velocity (1.6 m/sec) above the rounded crestal area of the dune record the recovery of the wind speed profile from flow divergence, which is a response to the rapid reduction of dune gradient and is accompanied by deposition of sand in this region. 2 The erosion pin data act as a simple and sensitive test for changes in gradient, reflecting the dune's response to changes in the airflow regime. The shape of the dune plays a major role in determining the extent of the compression and the distribution of shear velocity up the slope. Increased shear velocity is experienced on that part of the slope which is nonaerodynamic with respect to the prevailing wind. Under unidirectional conditions, feedback between flow and form results ultimately in a slope with a curvature such that shear velocity increases systematically upslope. The survey data and erosion pin data record the reversal process as the dune achieves a new steady state during each wind season. The existence of a non-logarithmic wind speed profile makes it difficult to know what relevant measure of shear velocity is to be used in sand transport equations. Future work should include wind speed measurements within 10 cm of the surface. An ideal study modelling aeolian bedform development would utilise wind tunnel measurements, combined with field measurements such as obtained in this study, for comparison with numerical modelling. The study needs to be extended to 3-dimensional airflow measurements. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2021
- Full Text:
- Date Issued: 2021-04
The role of national culture characteristics and business orientations in Tanzanian small business success
- Authors: Chachage, Bukaza Loth
- Date: 2021-04
- Subjects: Success in business -- Tanzania , Small business -- Tanzania , New business enterprises -- Tanzania
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/51061 , vital:43205
- Description: Despite numerous efforts to increase the business success of Tanzanian small businesses, it is still reported that progress in this regard has stagnated. The desired success in the SMME sector, and small businesses, is not being achieved, and is one of the reasons poverty in Tanzania remains significantly high. Researchers have suggested that low-income countries (LICs) such as Tanzania often do not achieve the desired growth of business enterprises due to insufficient attention being paid to issues of national culture and business orientations. Against this background, the purpose of the current study is to contribute to small business success in Tanzania by investigating the role that national culture characteristics (egalitarianism, mastery, harmony, embeddedness, affective autonomy and intellectual autonomy) and business orientations (technology, market and entrepreneurial) play in increasing the business success of Tanzanian small businesses. In this study, business success is defined as the extent to which small businesses effectively manage marketing, operations, human resources and finances. Located in the quantitative research paradigm, and using a mail survey data collection method, a sample of 640 SMMEs was targeted from eight regional economic zones in Tanzania. Of this group, 410 SMMEs, mostly small businesses, participated in the study (response rate = 64%). Instruments based on the works of Burgess (2011) and Schwartz (2004) were used to measure the business orientations and national culture characteristics of the selected Tanzanian small business owners and managers. The instrument developed by the South African Small Enterprise Development Agency (SEDA 2004) was used to measure small business success. The data analyses in this study included tests for data normalcy and the reliability and validity of the data (using Cronbach ‘s alpha and confirmatory factor analysis, respectively). Furthermore, multiple regression analyses were conducted to investigate the hypothesised relationships and other research propositions. The results of this study provided sound empirical proof of the interactive influence of national culture characteristics and business orientations on the business success of small businesses. Based on these empirical findings, a proposed framework for small business success in Tanzania was developed. The empirical results of the study provided evidence that support several existing theories, perceptions and beliefs about the relationship between national culture characteristics and business orientations. Certain findings also provided evidence that challenged aspects of existing theories, perceptions and beliefs. The study specifically highlights the importance of the technology and entrepreneurial business orientations as key positive determinants of the effectiveness of all four business functions (marketing, operations, human resources and financial management) investigated in the study. A surprising finding was the significantly negative relationship between market orientation and human resources management. The study also highlighted the centrality of the national characteristics of egalitarianism and intellectual autonomy in the development of the three business orientations (technology, entrepreneurial and market) investigated in the study. The findings suggest that the principle of the equality of people and a commitment to the continuous search and rewarding of new ideas and unique ways of doing things through continuous and professional development are important drivers of critical business orientations among Tanzanian small business owners and managers. The empirical findings furthermore highlighted the importance of mastery as a national culture characteristic. Mastery, which emphasises competence, goal-setting, hard-work, efficiency, effectiveness and self-reliance in attaining goals, influenced the effectiveness of all four business functions and two of the three business orientations investigated in the study. Finally, the study made significant contributions to the understanding of small business success in Tanzania and, arguably, across the African continent. The infusion of these insights into strategies for entrepreneurship development will go a long way to building successful businesses in the small business sector. , Thesis (DBA) -- Faculty of Business and Economic Sciences, Business Administration, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Chachage, Bukaza Loth
- Date: 2021-04
- Subjects: Success in business -- Tanzania , Small business -- Tanzania , New business enterprises -- Tanzania
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/51061 , vital:43205
- Description: Despite numerous efforts to increase the business success of Tanzanian small businesses, it is still reported that progress in this regard has stagnated. The desired success in the SMME sector, and small businesses, is not being achieved, and is one of the reasons poverty in Tanzania remains significantly high. Researchers have suggested that low-income countries (LICs) such as Tanzania often do not achieve the desired growth of business enterprises due to insufficient attention being paid to issues of national culture and business orientations. Against this background, the purpose of the current study is to contribute to small business success in Tanzania by investigating the role that national culture characteristics (egalitarianism, mastery, harmony, embeddedness, affective autonomy and intellectual autonomy) and business orientations (technology, market and entrepreneurial) play in increasing the business success of Tanzanian small businesses. In this study, business success is defined as the extent to which small businesses effectively manage marketing, operations, human resources and finances. Located in the quantitative research paradigm, and using a mail survey data collection method, a sample of 640 SMMEs was targeted from eight regional economic zones in Tanzania. Of this group, 410 SMMEs, mostly small businesses, participated in the study (response rate = 64%). Instruments based on the works of Burgess (2011) and Schwartz (2004) were used to measure the business orientations and national culture characteristics of the selected Tanzanian small business owners and managers. The instrument developed by the South African Small Enterprise Development Agency (SEDA 2004) was used to measure small business success. The data analyses in this study included tests for data normalcy and the reliability and validity of the data (using Cronbach ‘s alpha and confirmatory factor analysis, respectively). Furthermore, multiple regression analyses were conducted to investigate the hypothesised relationships and other research propositions. The results of this study provided sound empirical proof of the interactive influence of national culture characteristics and business orientations on the business success of small businesses. Based on these empirical findings, a proposed framework for small business success in Tanzania was developed. The empirical results of the study provided evidence that support several existing theories, perceptions and beliefs about the relationship between national culture characteristics and business orientations. Certain findings also provided evidence that challenged aspects of existing theories, perceptions and beliefs. The study specifically highlights the importance of the technology and entrepreneurial business orientations as key positive determinants of the effectiveness of all four business functions (marketing, operations, human resources and financial management) investigated in the study. A surprising finding was the significantly negative relationship between market orientation and human resources management. The study also highlighted the centrality of the national characteristics of egalitarianism and intellectual autonomy in the development of the three business orientations (technology, entrepreneurial and market) investigated in the study. The findings suggest that the principle of the equality of people and a commitment to the continuous search and rewarding of new ideas and unique ways of doing things through continuous and professional development are important drivers of critical business orientations among Tanzanian small business owners and managers. The empirical findings furthermore highlighted the importance of mastery as a national culture characteristic. Mastery, which emphasises competence, goal-setting, hard-work, efficiency, effectiveness and self-reliance in attaining goals, influenced the effectiveness of all four business functions and two of the three business orientations investigated in the study. Finally, the study made significant contributions to the understanding of small business success in Tanzania and, arguably, across the African continent. The infusion of these insights into strategies for entrepreneurship development will go a long way to building successful businesses in the small business sector. , Thesis (DBA) -- Faculty of Business and Economic Sciences, Business Administration, 2021
- Full Text:
- Date Issued: 2021-04
Perceived impact of cyberbullying on young adults’ psychological well-being
- Authors: Whitehorn, Hayley
- Date: 2021-04
- Subjects: Cyberbullying -- South Africa -- Psychological aspects , Youth -- Crimes against -- Psychological aspects
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/52374 , vital:43620
- Description: Cyberbullying is a significant field of study within cyberpsychology and requires continued research and development in order to further literature and understanding in a South African context. An increase in cyberbullying results in an increased prevalence of the occurrence of psychological distress in the form of short-term consequences as well as long-term chronic impacts such as depression, anxiety, and decreased life satisfaction. This qualitative study aimed to explore and describe the experiences of young adults who have experienced cyberbullying and the perceived impact of this experience on their psychological well-being. Qualitative research is a flexible exploratory and descriptive approach to understanding the lived experiences of an individual and their subjective view of a specific phenomenon through an interpretivist paradigm. This study utilised purposive and snowball sampling of Nelson Mandela University students aged 18 – 25 years old to gain a total of 6 participants for data gathering through semi-structured interviews. This research process followed a retrospective perspective which focuses on the specific meaning-making and understandings which that individual places on that experience, in relation to their psychological well-being. Thematic analysis was employed to analyse the data and trustworthiness criteria and was utilised throughout to ensure the credibility of the study. It was found that cyberbullying, through multiple forms and methods, has various short-term and long-term perceived impacts in several spheres. The perceived psychological impacts occurred in the short-term and were internalised to extend to long-term impacts on psychological well-being, of which the majority were negative. There are influencing factors to the development, coping and management of perceived long-term impacts which reflect the outcomes on well-being. The findings of this study highlight the perceived impact of cyberbullying on young adults’ psychological well-being which is vital for future recommendations and intervention. , Thesis (MA) -- Faculty of Health Sciences, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Whitehorn, Hayley
- Date: 2021-04
- Subjects: Cyberbullying -- South Africa -- Psychological aspects , Youth -- Crimes against -- Psychological aspects
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/52374 , vital:43620
- Description: Cyberbullying is a significant field of study within cyberpsychology and requires continued research and development in order to further literature and understanding in a South African context. An increase in cyberbullying results in an increased prevalence of the occurrence of psychological distress in the form of short-term consequences as well as long-term chronic impacts such as depression, anxiety, and decreased life satisfaction. This qualitative study aimed to explore and describe the experiences of young adults who have experienced cyberbullying and the perceived impact of this experience on their psychological well-being. Qualitative research is a flexible exploratory and descriptive approach to understanding the lived experiences of an individual and their subjective view of a specific phenomenon through an interpretivist paradigm. This study utilised purposive and snowball sampling of Nelson Mandela University students aged 18 – 25 years old to gain a total of 6 participants for data gathering through semi-structured interviews. This research process followed a retrospective perspective which focuses on the specific meaning-making and understandings which that individual places on that experience, in relation to their psychological well-being. Thematic analysis was employed to analyse the data and trustworthiness criteria and was utilised throughout to ensure the credibility of the study. It was found that cyberbullying, through multiple forms and methods, has various short-term and long-term perceived impacts in several spheres. The perceived psychological impacts occurred in the short-term and were internalised to extend to long-term impacts on psychological well-being, of which the majority were negative. There are influencing factors to the development, coping and management of perceived long-term impacts which reflect the outcomes on well-being. The findings of this study highlight the perceived impact of cyberbullying on young adults’ psychological well-being which is vital for future recommendations and intervention. , Thesis (MA) -- Faculty of Health Sciences, 2021
- Full Text:
- Date Issued: 2021-04
Physical activity, physical fitness, sedentary behaviour and screen time profiles of primary school children in a school within the Makana Municipality, Eastern Cape, South Africa
- Authors: Kade, Andréa Gaby
- Date: 2021-04
- Subjects: Sedentary behavior in children -- South Africa -- Makana Municipality , Physical fitness for children -- South Africa -- Makana Municipality , Exercise -- Physiological aspects , Exercise -- Health aspects , Diabetes -- Risk factors , Heart -- Diseases -- Risk factors
- Language: English
- Type: thesis , text , Masters , MSc
- Identifier: http://hdl.handle.net/10962/177282 , vital:42806
- Description: There is a lack of data on the physical activity, physical fitness and sedentary behaviour of children in South Africa. Furthermore chronic diseases such as type II diabetes and coronary heart disease have been linked to childhood inactivity, and improving cardiorespiratory fitness and increasing levels of physical activity has been shown to be beneficial in reducing the risk of such diseases. In South Africa more broadly there is a lack of information on levels of physical activity and sedentary behaviour as well as physical fitness measures particularly in children. Objective: The purpose of this study was to enhance the existing body of knowledge on this, by measuring the prevalence of physical inactivity, sedentary behaviour and screen time of primary school children in a private school from the Makana Municipal region in the Eastern Cape Province of South Africa, where the evidence is most sparse. A secondary aim was to assess levels of physical fitness in this cohort, as well as to compare across grades and sexes. Method: After ethical approval was granted, stature and body mass measurements were taken and body mass index was computed for primary school children (Grade one to seven) from a private school in the Makana Municipality. Sitting stature was measured in order to determine each child’s peak height velocity and maturity offset. Five different physical fitness tests were conducted on the children and blood pressure and heart rate values were measured at rest. Physical activity and screen time questionnaires were completed by the children’s parents for a seven day period. Results: Females were found to mature faster than males. In addition females were more physically active (Females= 916 min/week; Males= 669 min/week) while also accumulating more sedentary time (Females= 1241 min/week; Males= 970 min/week) as compared to males, although no significant differences were found between males and females for these variables. The sample participated in more than 60 minutes of moderate-to-vigorous physical activity and less than two hours of screen time daily, which is in accordance with guidelines. No differences were found between grades and sexes for accumulated screen time. Strength increased significantly with grade and age, and there were also statistical differences between the sexes for all three strength measures with males being stronger than females. Females were more flexible than males and no statistical differences were found between sexes for the shuttle run test. Blood pressure correlated positively with mass, as did all the strength measures as well as maturity offset. No correlations were found between screen time and all other variables. A negative relationship was recorded between screen time and physical activity, although not significant. For females a strong positive correlation was found between sedentary behaviour and physical activity. Conclusion: The study was successful in adding to the body of knowledge regarding the prevalence of physical inactivity, sedentary behaviour and screen time within school children from the Makana Municipality in the Eastern Cape Province of South Africa. The sample was considered physically active as they accumulated on average more than 60 minutes of moderate-to-vigorous physical activity daily (Males= 96 min/day; Females 130 min/day), which is in accordance with guidelines recommended by the World Health Organization (World Health Organization, 2018). The sample accumulated more sedentary behaviour than physical activity, although not significant. Screen time was below regulations of two hours daily, indicating this population participated in more non screen related sedentary behaviour. More research is needed into the risks presented with different forms of sedentary behaviour. Physical fitness increased with increasing grade and age and males were considerably more fit. The current study did not present any concern with regards to the effects of increased physical activity and fitness levels within school aged children. More research into the current levels of physical activity, physical fitness and sedentary behaviour of school aged children in South Africa in general, and in the Eastern Cape Province, is needed. , Thesis (MSc) -- Faculty of Science, Human Kinetics and Ergonomics, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Kade, Andréa Gaby
- Date: 2021-04
- Subjects: Sedentary behavior in children -- South Africa -- Makana Municipality , Physical fitness for children -- South Africa -- Makana Municipality , Exercise -- Physiological aspects , Exercise -- Health aspects , Diabetes -- Risk factors , Heart -- Diseases -- Risk factors
- Language: English
- Type: thesis , text , Masters , MSc
- Identifier: http://hdl.handle.net/10962/177282 , vital:42806
- Description: There is a lack of data on the physical activity, physical fitness and sedentary behaviour of children in South Africa. Furthermore chronic diseases such as type II diabetes and coronary heart disease have been linked to childhood inactivity, and improving cardiorespiratory fitness and increasing levels of physical activity has been shown to be beneficial in reducing the risk of such diseases. In South Africa more broadly there is a lack of information on levels of physical activity and sedentary behaviour as well as physical fitness measures particularly in children. Objective: The purpose of this study was to enhance the existing body of knowledge on this, by measuring the prevalence of physical inactivity, sedentary behaviour and screen time of primary school children in a private school from the Makana Municipal region in the Eastern Cape Province of South Africa, where the evidence is most sparse. A secondary aim was to assess levels of physical fitness in this cohort, as well as to compare across grades and sexes. Method: After ethical approval was granted, stature and body mass measurements were taken and body mass index was computed for primary school children (Grade one to seven) from a private school in the Makana Municipality. Sitting stature was measured in order to determine each child’s peak height velocity and maturity offset. Five different physical fitness tests were conducted on the children and blood pressure and heart rate values were measured at rest. Physical activity and screen time questionnaires were completed by the children’s parents for a seven day period. Results: Females were found to mature faster than males. In addition females were more physically active (Females= 916 min/week; Males= 669 min/week) while also accumulating more sedentary time (Females= 1241 min/week; Males= 970 min/week) as compared to males, although no significant differences were found between males and females for these variables. The sample participated in more than 60 minutes of moderate-to-vigorous physical activity and less than two hours of screen time daily, which is in accordance with guidelines. No differences were found between grades and sexes for accumulated screen time. Strength increased significantly with grade and age, and there were also statistical differences between the sexes for all three strength measures with males being stronger than females. Females were more flexible than males and no statistical differences were found between sexes for the shuttle run test. Blood pressure correlated positively with mass, as did all the strength measures as well as maturity offset. No correlations were found between screen time and all other variables. A negative relationship was recorded between screen time and physical activity, although not significant. For females a strong positive correlation was found between sedentary behaviour and physical activity. Conclusion: The study was successful in adding to the body of knowledge regarding the prevalence of physical inactivity, sedentary behaviour and screen time within school children from the Makana Municipality in the Eastern Cape Province of South Africa. The sample was considered physically active as they accumulated on average more than 60 minutes of moderate-to-vigorous physical activity daily (Males= 96 min/day; Females 130 min/day), which is in accordance with guidelines recommended by the World Health Organization (World Health Organization, 2018). The sample accumulated more sedentary behaviour than physical activity, although not significant. Screen time was below regulations of two hours daily, indicating this population participated in more non screen related sedentary behaviour. More research is needed into the risks presented with different forms of sedentary behaviour. Physical fitness increased with increasing grade and age and males were considerably more fit. The current study did not present any concern with regards to the effects of increased physical activity and fitness levels within school aged children. More research into the current levels of physical activity, physical fitness and sedentary behaviour of school aged children in South Africa in general, and in the Eastern Cape Province, is needed. , Thesis (MSc) -- Faculty of Science, Human Kinetics and Ergonomics, 2021
- Full Text:
- Date Issued: 2021-04
Inhibitor search and variant analysis of Acetylcholinesterase
- Authors: Ras, Harnaud
- Date: 2021-04
- Subjects: Acetylcholinesterase , Alzheimer's disease , Acetylcholinesterase -- Inhibitors , Alzheimer's disease -- Chemotherapy , Cerebrovascular disease -- Treatment , Molecular mechanics Poisson–Boltzmann surface area (MM-PBSA)
- Language: English
- Type: thesis , text , Masters , MSc
- Identifier: http://hdl.handle.net/10962/178191 , vital:42919
- Description: Acetylcholinesterase (AChE) inhibition is used to treat Alzheimer's disease by increasing the availability of acetylcholine to carry nerve signals in the brain. The response to this treatment varies widely, which may be due to altered affnity to the current drugs caused by genetic variation. Various negative side-effects limit their use. As this is one of the only available therapeutic drug targets to treat Alzheimer's disease, decreasing the negative effects is of great importance. AChE is involved in biological processes that occur after acute ischemic stroke. Stroke is the third leading cause of death worldwide, and 87% of all stroke cases belong to ischemic stroke. AchEI (cholinesterase inhibitors) have been suggested to have properties that lower the risk of stroke. AChE is one of 15 verified drug targets under study for treatment of stroke. In addition to Alzheimer's disease and stroke, Lewy body disease (LBD) may be treated using cholinesterase inhibitors. The goals of this study are to find inhibitors that can potentially be used to treat Alzheimer's disease and/or stroke and to investigate variants which may affect protein dynamics and function. Two variants were analyzed, P247L and T229S. Molecular simulation of the P247L variant resulted in a disruption in protein dynamics in comparison to the wildtype. A total of 5728 molecules were screened and 10 nanosecond simulations were used to narrow down the set of compounds. The four best performing molecules were simulated for 10 nanoseconds. MM-PBSA was performed to identify molecules with high binding free energies. , Thesis (MSc) -- Faculty of Science, Biochemistry and Microbiology, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Ras, Harnaud
- Date: 2021-04
- Subjects: Acetylcholinesterase , Alzheimer's disease , Acetylcholinesterase -- Inhibitors , Alzheimer's disease -- Chemotherapy , Cerebrovascular disease -- Treatment , Molecular mechanics Poisson–Boltzmann surface area (MM-PBSA)
- Language: English
- Type: thesis , text , Masters , MSc
- Identifier: http://hdl.handle.net/10962/178191 , vital:42919
- Description: Acetylcholinesterase (AChE) inhibition is used to treat Alzheimer's disease by increasing the availability of acetylcholine to carry nerve signals in the brain. The response to this treatment varies widely, which may be due to altered affnity to the current drugs caused by genetic variation. Various negative side-effects limit their use. As this is one of the only available therapeutic drug targets to treat Alzheimer's disease, decreasing the negative effects is of great importance. AChE is involved in biological processes that occur after acute ischemic stroke. Stroke is the third leading cause of death worldwide, and 87% of all stroke cases belong to ischemic stroke. AchEI (cholinesterase inhibitors) have been suggested to have properties that lower the risk of stroke. AChE is one of 15 verified drug targets under study for treatment of stroke. In addition to Alzheimer's disease and stroke, Lewy body disease (LBD) may be treated using cholinesterase inhibitors. The goals of this study are to find inhibitors that can potentially be used to treat Alzheimer's disease and/or stroke and to investigate variants which may affect protein dynamics and function. Two variants were analyzed, P247L and T229S. Molecular simulation of the P247L variant resulted in a disruption in protein dynamics in comparison to the wildtype. A total of 5728 molecules were screened and 10 nanosecond simulations were used to narrow down the set of compounds. The four best performing molecules were simulated for 10 nanoseconds. MM-PBSA was performed to identify molecules with high binding free energies. , Thesis (MSc) -- Faculty of Science, Biochemistry and Microbiology, 2021
- Full Text:
- Date Issued: 2021-04
An analysis of supply chain management procedures within the Nelson Mandela Bay Municipality
- Authors: Zizipho, Goniwe
- Date: 2021-04
- Subjects: Business logistics -- South Africa -- Nelson Mandela Bay Municipality , Industrial procurement -- South Africa -- Nelson Mandela Bay Municipality -- Management
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/52524 , vital:43683
- Description: This study has analysed the Supply Chain Management (SCM) procedures in the Nelson Mandela Bay Municipality. Moreover, subsequent the research study provided a brief background on the local government SCM and the significance of the study which lies on its contribution in the improvement of SCM policies and procedures within the NMBMM. The problem that driven this study is the lack and inadequate use of SCM policies, procedures, practices, and systems in municipalities which that may lead to the misuse of public funds as well as poor service delivery. To address SCM issues in local government, SCM policy was adopted by the Cabinet of Republic of South Africa in 2003 as a way to address noted deficiencies in its public procurement processes within the SCM. This is in conjunction with the number of legislative frameworks were set to guide processes and procedures in this department. This research adopted the use of qualitative approach, for the purpose of this study it is the suitable approach due to time and resources efficiency, as it used desktop analysis and the secondary data which entails internet sources. Based on the literature review findings the study shows the application of six SCM elements, as outlined in the NMBMM SCM Policy. The recommendations of the study setting more emphasis on online tender application procedure. The effective employment of these recommendations can improve the processes and procedures in local government SCM, specifically NMBMM, and this can address the problem of lack of and inadequate use of SCM policies. Transforming NMBMM to the most effective, accountable, responsive local government prioritising the needs of public. , Thesis (MPA) -- Faculty of Humanities, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Zizipho, Goniwe
- Date: 2021-04
- Subjects: Business logistics -- South Africa -- Nelson Mandela Bay Municipality , Industrial procurement -- South Africa -- Nelson Mandela Bay Municipality -- Management
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/52524 , vital:43683
- Description: This study has analysed the Supply Chain Management (SCM) procedures in the Nelson Mandela Bay Municipality. Moreover, subsequent the research study provided a brief background on the local government SCM and the significance of the study which lies on its contribution in the improvement of SCM policies and procedures within the NMBMM. The problem that driven this study is the lack and inadequate use of SCM policies, procedures, practices, and systems in municipalities which that may lead to the misuse of public funds as well as poor service delivery. To address SCM issues in local government, SCM policy was adopted by the Cabinet of Republic of South Africa in 2003 as a way to address noted deficiencies in its public procurement processes within the SCM. This is in conjunction with the number of legislative frameworks were set to guide processes and procedures in this department. This research adopted the use of qualitative approach, for the purpose of this study it is the suitable approach due to time and resources efficiency, as it used desktop analysis and the secondary data which entails internet sources. Based on the literature review findings the study shows the application of six SCM elements, as outlined in the NMBMM SCM Policy. The recommendations of the study setting more emphasis on online tender application procedure. The effective employment of these recommendations can improve the processes and procedures in local government SCM, specifically NMBMM, and this can address the problem of lack of and inadequate use of SCM policies. Transforming NMBMM to the most effective, accountable, responsive local government prioritising the needs of public. , Thesis (MPA) -- Faculty of Humanities, 2021
- Full Text:
- Date Issued: 2021-04
Effect of fire frequency on the recovery of soil invertebrate communities in semi-arid savanna biome of the Eastern Cape, South Africa
- Madikana, Ayabulela https://orcid.org/0000-0002-9119-4650
- Authors: Madikana, Ayabulela https://orcid.org/0000-0002-9119-4650
- Date: 2021-04
- Subjects: Soil invertebrates , Fire ecology , Arid regions
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22831 , vital:52946
- Description: Fires are common in South African savanna habitats, which can disrupt the dynamics of entire invertebrate populations, endangering biodiversity and the environment. The aim of this study was to look at how fire frequency affected invertebrate population dynamics and biodiversity in a 41-year-old fire experiment at the University of Fort Hare research farm in Alice. The experiment had six different levels of burning frequency: no-burn (K), annual burn (B1), biannual burn (B2), triennial burn (B3), quadrennial burn (B4), and sexennial burn (B6). The experimental plots were replicated two times in a randomized complete block design and have been continuously retained since 1980. A ground yellow mustard solution was used to collect earthworms, which were then identified by an earthworm taxonomist. Pitfall traps were used to collect ants and other insects, which were then identified under a microscope. In total, three soil samples were collected from each plot to assess selected soil nutrients, moisture, and pH. The Shannon diversity index, richness, and population of earthworms, ants, and other insects were calculated, and a one-way ANOVA analysis was done to check if the treatments differed significantly. A correlations study was used to look for any influence connected to soil parameters, including the Shannon diversity index, species richness, and density of soil invertebrates. According to our findings, the measured parameters did not show any significant differences in the measured parameters between the different frequency levels. All the plots had two species of earthworm , Proandricus timmianus and Proandricus beddardi except the biennial burn plot, which had all three, the afore mentioned species and one other unidentified species, Proandricus sp. The triennial burn treatment slightly enhanced the insect diversity, richness, and evenness of ant species difference while the diversity, evenness, and richness were lowest in the sexennial burn plot. However, there was no signif difference in population. After B4, the no burn plot had the second largest diversity and species richness, and the third highest species evenness and had a 100 percent species similarity index. The ants were evenly distributed in the no burn plot compared to the other plots, with K having a lower density than the other plots except for B4, K being slightly more diverse than B6, and B1 with a slightly lower diversity than the other plots, and it being the third species rich plot after B2 and B3, followed by the rest of the plots. This study implied that fire frequency has an insignificant impact on invertebrates’ communities in Savanna biomes words.icant , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Madikana, Ayabulela https://orcid.org/0000-0002-9119-4650
- Date: 2021-04
- Subjects: Soil invertebrates , Fire ecology , Arid regions
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22831 , vital:52946
- Description: Fires are common in South African savanna habitats, which can disrupt the dynamics of entire invertebrate populations, endangering biodiversity and the environment. The aim of this study was to look at how fire frequency affected invertebrate population dynamics and biodiversity in a 41-year-old fire experiment at the University of Fort Hare research farm in Alice. The experiment had six different levels of burning frequency: no-burn (K), annual burn (B1), biannual burn (B2), triennial burn (B3), quadrennial burn (B4), and sexennial burn (B6). The experimental plots were replicated two times in a randomized complete block design and have been continuously retained since 1980. A ground yellow mustard solution was used to collect earthworms, which were then identified by an earthworm taxonomist. Pitfall traps were used to collect ants and other insects, which were then identified under a microscope. In total, three soil samples were collected from each plot to assess selected soil nutrients, moisture, and pH. The Shannon diversity index, richness, and population of earthworms, ants, and other insects were calculated, and a one-way ANOVA analysis was done to check if the treatments differed significantly. A correlations study was used to look for any influence connected to soil parameters, including the Shannon diversity index, species richness, and density of soil invertebrates. According to our findings, the measured parameters did not show any significant differences in the measured parameters between the different frequency levels. All the plots had two species of earthworm , Proandricus timmianus and Proandricus beddardi except the biennial burn plot, which had all three, the afore mentioned species and one other unidentified species, Proandricus sp. The triennial burn treatment slightly enhanced the insect diversity, richness, and evenness of ant species difference while the diversity, evenness, and richness were lowest in the sexennial burn plot. However, there was no signif difference in population. After B4, the no burn plot had the second largest diversity and species richness, and the third highest species evenness and had a 100 percent species similarity index. The ants were evenly distributed in the no burn plot compared to the other plots, with K having a lower density than the other plots except for B4, K being slightly more diverse than B6, and B1 with a slightly lower diversity than the other plots, and it being the third species rich plot after B2 and B3, followed by the rest of the plots. This study implied that fire frequency has an insignificant impact on invertebrates’ communities in Savanna biomes words.icant , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-04
Ranked factors influencing the sustainability and growth of SMMEs in the city of Port Elizabeth
- Authors: Bussy, Matthew
- Date: 2021-04
- Subjects: Business enterprises -- South Africa -- Port Elizabeth , Small business -- South Africa -- Port Elizabeth , Sustainable development -- South Africa -- Port Elizabeth
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/51050 , vital:43204
- Description: SMMEs are the backbone of both established and developing economies with their ability to contribute to a country’s GDP, create employment, stimulate innovation and create new revenue streams. In South Africa the majority of SMMEs do not reach the critical threshold period for sustainability, defined by the Small Enterprise Development Agency (SEDA) as three years. This study explores twenty-five barriers and influences (nine external and sixteen internal) as experienced by small businesses operating in the city of Port Elizabeth, and their effect on the sustainability and success of the small business. The internal barriers and influences are ranked according to their relative importance to business sustainability and success as viewed by small businesses in the city of Port Elizabeth. The research is exploratory in nature and was conducted using a structured questionnaire. The findings show that the nineteen barriers and influencers that are controllable within the business are all important to the success and sustainability of small businesses. Of these internal factors, the most important one relatively speaking is found to be the general management abilities of management, and the least important, relatively speaking, is the education levels of the non-management employees. , Thesis (MBA) -- Faculty of Business and Economic Sciences, Business Administration, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Bussy, Matthew
- Date: 2021-04
- Subjects: Business enterprises -- South Africa -- Port Elizabeth , Small business -- South Africa -- Port Elizabeth , Sustainable development -- South Africa -- Port Elizabeth
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/51050 , vital:43204
- Description: SMMEs are the backbone of both established and developing economies with their ability to contribute to a country’s GDP, create employment, stimulate innovation and create new revenue streams. In South Africa the majority of SMMEs do not reach the critical threshold period for sustainability, defined by the Small Enterprise Development Agency (SEDA) as three years. This study explores twenty-five barriers and influences (nine external and sixteen internal) as experienced by small businesses operating in the city of Port Elizabeth, and their effect on the sustainability and success of the small business. The internal barriers and influences are ranked according to their relative importance to business sustainability and success as viewed by small businesses in the city of Port Elizabeth. The research is exploratory in nature and was conducted using a structured questionnaire. The findings show that the nineteen barriers and influencers that are controllable within the business are all important to the success and sustainability of small businesses. Of these internal factors, the most important one relatively speaking is found to be the general management abilities of management, and the least important, relatively speaking, is the education levels of the non-management employees. , Thesis (MBA) -- Faculty of Business and Economic Sciences, Business Administration, 2021
- Full Text:
- Date Issued: 2021-04
Impact of automation technologies on employment
- Authors: Dukashe, Loyiso
- Date: 2021-04
- Subjects: Automation , Automation -- Economic aspects , Employees -- Technological innovations
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/51335 , vital:43265
- Description: Throughout history, the introduction of automated technologies has an impact on on human labour. The current wave of technological advancement has expanded the scope of automation raising a concern about the future relevance of human labour. Hence, this study investigated possible futures on the effect of automation technologies on employment. The study adopted a desktop research approach using secondary sources employing future studies methodologies. The study identified a need to transform employment, educational systems and social policy to proactively respond to future effects of automation technologies towards employment. , Thesis (MBA) -- Faculty of Business and Economic Sciences, Business Administration, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Dukashe, Loyiso
- Date: 2021-04
- Subjects: Automation , Automation -- Economic aspects , Employees -- Technological innovations
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/51335 , vital:43265
- Description: Throughout history, the introduction of automated technologies has an impact on on human labour. The current wave of technological advancement has expanded the scope of automation raising a concern about the future relevance of human labour. Hence, this study investigated possible futures on the effect of automation technologies on employment. The study adopted a desktop research approach using secondary sources employing future studies methodologies. The study identified a need to transform employment, educational systems and social policy to proactively respond to future effects of automation technologies towards employment. , Thesis (MBA) -- Faculty of Business and Economic Sciences, Business Administration, 2021
- Full Text:
- Date Issued: 2021-04
The effect of transport infrastructure investment on economic growth in South Africa
- Authors: Matsolo, Khanya
- Date: 2021-04
- Subjects: Transportation -- South Africa , Infrastructure (Economics) -- South Africa , Economic development -- South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/51699 , vital:43364
- Description: The objective of the study was to examine the effect of transport infrastructure investment on economic growth of South Africa. The time series data that covered the period from 2001-2019 using converted quarterly data was used. The study applied autoregressive distributed lag (ARDL) to analyse the relationship between transport infrastructure investment and economic growth in South Africa. The empirical results shows that there is positive relationship between these two variables both in the short run and long run. Thus, it is recommended that policy makers should develop strategies that are aligned with effective and efficient transport infrastructure investment to enhance economic growth in South Africa. , Thesis (MPhil) -- Faculty of Business and Economic Sciences, Development Finance, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Matsolo, Khanya
- Date: 2021-04
- Subjects: Transportation -- South Africa , Infrastructure (Economics) -- South Africa , Economic development -- South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/51699 , vital:43364
- Description: The objective of the study was to examine the effect of transport infrastructure investment on economic growth of South Africa. The time series data that covered the period from 2001-2019 using converted quarterly data was used. The study applied autoregressive distributed lag (ARDL) to analyse the relationship between transport infrastructure investment and economic growth in South Africa. The empirical results shows that there is positive relationship between these two variables both in the short run and long run. Thus, it is recommended that policy makers should develop strategies that are aligned with effective and efficient transport infrastructure investment to enhance economic growth in South Africa. , Thesis (MPhil) -- Faculty of Business and Economic Sciences, Development Finance, 2021
- Full Text:
- Date Issued: 2021-04
Ultraprecision Diamond Turning of Monocrystalline Germanium
- Authors: Adeleke, Adeniyi Kehinde
- Date: 2021-04
- Subjects: Precision , Diamond Turning
- Language: English
- Type: Master's theses , Thesis
- Identifier: http://hdl.handle.net/10948/44453 , vital:37835
- Description: Infrared lens production demands a surface with a high degree of accuracy and integrity. Surface roughness is a critical index of the measure of any product’s surface integrity. As a result of this, ultra-high machining technology has enjoyed extensive application, due to the continuous request for components within the range of 1 – 10nm roughness value. This technology has brought about the increased productivity and manufacture of quality products with a top-notch surface finish. Brittle materials such as germanium are hard to machine through the conventional processes such as lapping and polishing. Hence, the ultra-precision machining technology based on single point diamond turning (SPDT), is now been applied to machine germanium in the ductile mode, where material chip removal occurs by plastic deformation instead of a brittle fracture. During machining, selecting the optimal cutting conditions which includes cutting parameters and tool geometry, will not only improve productivity but ensure the minimisation of operating cost. In this research work, SPDT operation was used to conduct two experiments on a (monocrystalline germanium) workpiece. The first experiment was carried out using a diamond tool with a 1.5 mm nose radius, while the second experiment employed the use of a tool having a nose radius of 1.0 mm. A combination of machining parameters for each of the experimental runs were derived from a Box-Behnken method of design and the surface roughness was measured at each interval for both experiments with the aid of a Taylor Hopson PGI Dimension XL profilometer. Acoustic emission (AE) was also used as a quality sensing and tool-monitoring technique, to acquire signals and give indications of the expected surface roughness. Predictive models based on response surface methodology (RSM) and artificial neural networks (ANN), were developed for determining surface roughness. Optimisation was performed using RSM to determine the optimal set of machining factors, which results in optimal condition of the output response. Further investigations on the acquired signals were carried out using signal-processing techniques. Time-domain and time-frequency domain features acquired from the AE signals, together with the process parameters, were employed as input variables in the neural network design, having shown a good association with the surface roughness. ix Conclusively, it can be observed that the predictive model results and the experimental roughness measurements are in good agreement with each other. For accuracy and cost of computation, the RSM and ANN developed models for single-crystal germanium are compared using mean absolute error (MAE). , Thesis (M.Eng) -- Faculty of Engineering, the built environment & Information Technology, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Adeleke, Adeniyi Kehinde
- Date: 2021-04
- Subjects: Precision , Diamond Turning
- Language: English
- Type: Master's theses , Thesis
- Identifier: http://hdl.handle.net/10948/44453 , vital:37835
- Description: Infrared lens production demands a surface with a high degree of accuracy and integrity. Surface roughness is a critical index of the measure of any product’s surface integrity. As a result of this, ultra-high machining technology has enjoyed extensive application, due to the continuous request for components within the range of 1 – 10nm roughness value. This technology has brought about the increased productivity and manufacture of quality products with a top-notch surface finish. Brittle materials such as germanium are hard to machine through the conventional processes such as lapping and polishing. Hence, the ultra-precision machining technology based on single point diamond turning (SPDT), is now been applied to machine germanium in the ductile mode, where material chip removal occurs by plastic deformation instead of a brittle fracture. During machining, selecting the optimal cutting conditions which includes cutting parameters and tool geometry, will not only improve productivity but ensure the minimisation of operating cost. In this research work, SPDT operation was used to conduct two experiments on a (monocrystalline germanium) workpiece. The first experiment was carried out using a diamond tool with a 1.5 mm nose radius, while the second experiment employed the use of a tool having a nose radius of 1.0 mm. A combination of machining parameters for each of the experimental runs were derived from a Box-Behnken method of design and the surface roughness was measured at each interval for both experiments with the aid of a Taylor Hopson PGI Dimension XL profilometer. Acoustic emission (AE) was also used as a quality sensing and tool-monitoring technique, to acquire signals and give indications of the expected surface roughness. Predictive models based on response surface methodology (RSM) and artificial neural networks (ANN), were developed for determining surface roughness. Optimisation was performed using RSM to determine the optimal set of machining factors, which results in optimal condition of the output response. Further investigations on the acquired signals were carried out using signal-processing techniques. Time-domain and time-frequency domain features acquired from the AE signals, together with the process parameters, were employed as input variables in the neural network design, having shown a good association with the surface roughness. ix Conclusively, it can be observed that the predictive model results and the experimental roughness measurements are in good agreement with each other. For accuracy and cost of computation, the RSM and ANN developed models for single-crystal germanium are compared using mean absolute error (MAE). , Thesis (M.Eng) -- Faculty of Engineering, the built environment & Information Technology, 2021
- Full Text:
- Date Issued: 2021-04
Bayesian tolerance intervals and their application to ballistic grouping consistency in competitive shooting
- Authors: Gardiner, Marcell
- Date: 2021-04
- Subjects: Gqeberha (South Africa) , Eastern Cape (South Africa) , Bayesian statistical decision theory -- South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/52456 , vital:43662
- Description: Competitive shooting has become immensely popular since the first modern Games held in 1896. Competitive shooting remains the fastest growing segment in the firearm industry, catering to individuals of all ages. Elite shooters are capable of reaching extreme levels of precision and accuracy, despite many factors existing that affect performance in Olympic shooting. One such factor is speed variability, which is dependent on the mass of the bullet, how constant is the lead being used, and, how constant the gunpowder is. The study focusses on the Bayesian simulation method proposed by Wolfinger (1998) for determining three kinds of tolerance intervals when applied to competitive shooting data, particularly examining speed variability. These tolerance intervals included the (𝛼𝛼,𝛿𝛿) tolerance interval (where 𝛼𝛼 is the content and 𝛿𝛿 is the confidence), the 𝛼𝛼 - expectation tolerance interval (where 𝛼𝛼 is the expected coverage of the interval) and the fixed-in advance tolerance interval in which the interval is held fixed and the proportion of process measurements it contains, is estimated. Speed measurements of individual shots fired were measured with either an Oeler 35P or Magneto Speed V3 chronograph and the data was fitted to a one-way random effects model. , Thesis (MSc) -- Faculty of Science, School of Computer Science, Mathematics, Physics and Statistics, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Gardiner, Marcell
- Date: 2021-04
- Subjects: Gqeberha (South Africa) , Eastern Cape (South Africa) , Bayesian statistical decision theory -- South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/52456 , vital:43662
- Description: Competitive shooting has become immensely popular since the first modern Games held in 1896. Competitive shooting remains the fastest growing segment in the firearm industry, catering to individuals of all ages. Elite shooters are capable of reaching extreme levels of precision and accuracy, despite many factors existing that affect performance in Olympic shooting. One such factor is speed variability, which is dependent on the mass of the bullet, how constant is the lead being used, and, how constant the gunpowder is. The study focusses on the Bayesian simulation method proposed by Wolfinger (1998) for determining three kinds of tolerance intervals when applied to competitive shooting data, particularly examining speed variability. These tolerance intervals included the (𝛼𝛼,𝛿𝛿) tolerance interval (where 𝛼𝛼 is the content and 𝛿𝛿 is the confidence), the 𝛼𝛼 - expectation tolerance interval (where 𝛼𝛼 is the expected coverage of the interval) and the fixed-in advance tolerance interval in which the interval is held fixed and the proportion of process measurements it contains, is estimated. Speed measurements of individual shots fired were measured with either an Oeler 35P or Magneto Speed V3 chronograph and the data was fitted to a one-way random effects model. , Thesis (MSc) -- Faculty of Science, School of Computer Science, Mathematics, Physics and Statistics, 2021
- Full Text:
- Date Issued: 2021-04
On the ideals and semimodules of commutative semirings
- Authors: Olivier, Ruan
- Date: 2021-04
- Subjects: Gqeberha (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/52782 , vital:44026
- Description: Semirings are a generalisation of rings where additive inverses need not exist. In this dissertation, we focus on results of commutative semirings with non-zero identity. Many results that we study are analogous to results from commutative rings with non-zero identity. Properties which are unique to semirings are also investigated, such as semirings where all elements are additively idempotent. The notion of ideals is examined in the context of a semiring. Specifically, prime ideals, maximal ideals, k-ideals and partitioning ideals of semirings are considered. Additionally, the module over a ring is generalised to a semimodule over a semiring. The emphasis is on prime subsemimodules and multiplication semimodules. Lastly, invertible ideals of semirings are examined. , Thesis (MSc) -- Faculty of Science, School of Computer Science, Mathematics, Physics and Statistics, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Olivier, Ruan
- Date: 2021-04
- Subjects: Gqeberha (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/52782 , vital:44026
- Description: Semirings are a generalisation of rings where additive inverses need not exist. In this dissertation, we focus on results of commutative semirings with non-zero identity. Many results that we study are analogous to results from commutative rings with non-zero identity. Properties which are unique to semirings are also investigated, such as semirings where all elements are additively idempotent. The notion of ideals is examined in the context of a semiring. Specifically, prime ideals, maximal ideals, k-ideals and partitioning ideals of semirings are considered. Additionally, the module over a ring is generalised to a semimodule over a semiring. The emphasis is on prime subsemimodules and multiplication semimodules. Lastly, invertible ideals of semirings are examined. , Thesis (MSc) -- Faculty of Science, School of Computer Science, Mathematics, Physics and Statistics, 2021
- Full Text:
- Date Issued: 2021-04
Biology, ecology and management of the Keurboom moth, Leto venus Cramer and the leafhopper Molopopterus sp. Jacobi in cultivated Honeybush (Cyclopia spp.)
- Authors: Mushore, Tapiwa Gift
- Date: 2021-04
- Subjects: Legumes , Legumes -- Diseases and pests , Hepialidae , Leafhoppers , Pests -- Biological control , Entomopathogenic fungi , Leafhoppers -- Biological control , Hepialidae -- Biological control , Keurboom moth (Leto venus Cramer) , Molopopterus sp. Jacobi , Honeybush (Cyclopia spp.)
- Language: English
- Type: thesis , text , Masters , MSc
- Identifier: http://hdl.handle.net/10962/177125 , vital:42792
- Description: Honeybush, Cyclopia spp. Vent (Fabaceae), farmers have raised pest concerns following commercial cultivation. The Keurboom moth Leto venus Cramer (Lepidoptera: Hepialidae) and the leafhopper Molopopterus sp. Jacobi (Hemiptera: Cicadellidae), are two of the major pests identified in cultivated Honeybush. Laboratory and field studies were conducted to gain an understanding of the biology of these two pests to inform future pest management solutions. Additionally, entomopathogenic fungi were isolated from Honeybush farms and screened for virulence against Molopopterus sp. as a possible management strategy. This study showed that the L. venus infestation on Honeybush was a product of four fixed effects; stem diameter, species of Cyclopia, Farm location and age of the plants. Cyclopia subternata, had the highest likelihood of infestation. Increase in age of the plants resulted in an increase in the stem diameter and therefore a higher probability of infestation. Stem diameter was also shown to be a significant predictor of infestation likelihood. Infestation severity, determined by the number of larvae per plant, was shown to be influenced by three fixed effects; stem diameter, plant species and Farm location. The results also showed that L. venus prefers to initiate penetration at, or just aboveground level. Laboratory studies showed that the leafhopper Molopopterus sp. undergoes five nymphal instars with an average egg incubation time of 20 days, development time from 1st instar to adult of 26 days and average generation time of 47 days. Laboratory experiments revealed variations in host preference by the leafhopper over a period of 15 days. Cyclopia longifolia was identified to be the most preferred species for feeding compared to the two other commonly cultivated species, C. subternata and C. maculata. The results were consistent with those obtained from the field survey which showed that leafhopper density was influenced by four fixed effects; plant species, age of the plant, Farm location and harvesting practices. There were significant differences in leafhopper density in different species with C. longifolia having the highest number of leafhoppers per plant. There were differences in leafhopper density in different farms as 57% of the sampled farms had leafhopper infestations, of these farms, Lodestone and Kurland had the highest leafhopper densities. Harvested plants were shown to have significantly higher leafhopper density than non-harvested plants. Age was also shown to influence leafhopper density, which reduced with an increase in the age of the plants. A total of 20 fungal isolates were recovered from 98 soil samples of which 70% were from Honeybush fields and 30% were from surrounding refugia. Fusarium oxysporum isolates comprised 20% of the recovered isolates, with Metarhizium anisopliae isolates making up the remainder. Laboratory bioassays against adults and nymphs of the leafhopper, Molopopterus sp., showed that F. oxysporum isolates induced 10 – 45% mortality and M. anisopliae isolates induce 30 – 80% mortality. Metarhizium anisopliae isolates J S1, KF S3, KF S11, KF S13, LS1 and LS2 were the most virulent and induced over 60% mortality in both Molopopterus sp. nymphs and adults. The results of this study showed pest preference towards different Cyclopia species. As such, they should be managed differently. Furthermore, L. venus was observed to occur in low densities, hence, it cannot be considered a major pest. However, Molopopterus sp. recorded high population densities making it a major pest in Honeybush production. Positive results indicated that some of the isolated fungal isolates have potential for control, an avenue worth investigating further. , Thesis (MSc) -- Faculty of Science, Department of Zoology and Entomology, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Mushore, Tapiwa Gift
- Date: 2021-04
- Subjects: Legumes , Legumes -- Diseases and pests , Hepialidae , Leafhoppers , Pests -- Biological control , Entomopathogenic fungi , Leafhoppers -- Biological control , Hepialidae -- Biological control , Keurboom moth (Leto venus Cramer) , Molopopterus sp. Jacobi , Honeybush (Cyclopia spp.)
- Language: English
- Type: thesis , text , Masters , MSc
- Identifier: http://hdl.handle.net/10962/177125 , vital:42792
- Description: Honeybush, Cyclopia spp. Vent (Fabaceae), farmers have raised pest concerns following commercial cultivation. The Keurboom moth Leto venus Cramer (Lepidoptera: Hepialidae) and the leafhopper Molopopterus sp. Jacobi (Hemiptera: Cicadellidae), are two of the major pests identified in cultivated Honeybush. Laboratory and field studies were conducted to gain an understanding of the biology of these two pests to inform future pest management solutions. Additionally, entomopathogenic fungi were isolated from Honeybush farms and screened for virulence against Molopopterus sp. as a possible management strategy. This study showed that the L. venus infestation on Honeybush was a product of four fixed effects; stem diameter, species of Cyclopia, Farm location and age of the plants. Cyclopia subternata, had the highest likelihood of infestation. Increase in age of the plants resulted in an increase in the stem diameter and therefore a higher probability of infestation. Stem diameter was also shown to be a significant predictor of infestation likelihood. Infestation severity, determined by the number of larvae per plant, was shown to be influenced by three fixed effects; stem diameter, plant species and Farm location. The results also showed that L. venus prefers to initiate penetration at, or just aboveground level. Laboratory studies showed that the leafhopper Molopopterus sp. undergoes five nymphal instars with an average egg incubation time of 20 days, development time from 1st instar to adult of 26 days and average generation time of 47 days. Laboratory experiments revealed variations in host preference by the leafhopper over a period of 15 days. Cyclopia longifolia was identified to be the most preferred species for feeding compared to the two other commonly cultivated species, C. subternata and C. maculata. The results were consistent with those obtained from the field survey which showed that leafhopper density was influenced by four fixed effects; plant species, age of the plant, Farm location and harvesting practices. There were significant differences in leafhopper density in different species with C. longifolia having the highest number of leafhoppers per plant. There were differences in leafhopper density in different farms as 57% of the sampled farms had leafhopper infestations, of these farms, Lodestone and Kurland had the highest leafhopper densities. Harvested plants were shown to have significantly higher leafhopper density than non-harvested plants. Age was also shown to influence leafhopper density, which reduced with an increase in the age of the plants. A total of 20 fungal isolates were recovered from 98 soil samples of which 70% were from Honeybush fields and 30% were from surrounding refugia. Fusarium oxysporum isolates comprised 20% of the recovered isolates, with Metarhizium anisopliae isolates making up the remainder. Laboratory bioassays against adults and nymphs of the leafhopper, Molopopterus sp., showed that F. oxysporum isolates induced 10 – 45% mortality and M. anisopliae isolates induce 30 – 80% mortality. Metarhizium anisopliae isolates J S1, KF S3, KF S11, KF S13, LS1 and LS2 were the most virulent and induced over 60% mortality in both Molopopterus sp. nymphs and adults. The results of this study showed pest preference towards different Cyclopia species. As such, they should be managed differently. Furthermore, L. venus was observed to occur in low densities, hence, it cannot be considered a major pest. However, Molopopterus sp. recorded high population densities making it a major pest in Honeybush production. Positive results indicated that some of the isolated fungal isolates have potential for control, an avenue worth investigating further. , Thesis (MSc) -- Faculty of Science, Department of Zoology and Entomology, 2021
- Full Text:
- Date Issued: 2021-04