Birthing process preparedness of first-time mothers in the public obstetric units of the Nelson Mandela Bay health district (NMBHD).
- Authors: Dlamini, Xolani
- Date: 2022-04
- Subjects: Birthparents , Nelson Mandela Bay Health District
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/58815 , vital:60126
- Description: The birthing process is a challenging, unpredictable yet a beautiful life event for birthing women, requiring reasonable birthing process preparedness on birthing woman to enhance her cooperation during the birthing process. Often first-time mothers lack their own frame of reference regarding the birthing process to improve their birthing process preparedness. As an alternative they are reliant on that of other people with birthing process experiences or on what they are told by midwives. The purpose of this study was to understand how was the preparedness of the birthing process of first-time mothers in the public obstetric units of the NMBHD. Thus, an indication of how ready were they, when the labour started. The objectives of the study were as follows, to: • explore and describe the birthing process preparedness of first-time mothers in the public obstetric units of the NMBHD and • formulate recommendations for midwives and nurse managers that would aid them in facilitating the birthing process preparedness of first-time mothers in public obstetric units in the NMBHD. The study adopted a qualitative research design with exploratory, descriptive and contextual approach. The research population were first-time mothers who had booked and delivered in any of the obstetric units in the NMBHD. The convenience, non-probability sampling methods were used in selecting the first-time mothers who met the inclusion criteria. Envisaged sample size was 21 participants but also depending on data saturation. Sixteen participants were ultimately interviewed but only fifteen of those interviews were used. The data collection method used was one-on-one semi-structured interviews which were captured on a digital voice-recorder. The thematic method of data analysis was used to analyse data from the interviews. Three main themes emerged from the data analysis: • Theme 1: Participants shared their experiences regarding the birthing process and their birthing process preparedness. • Theme 2: Participants expressed having had varied experiences from factors that had influenced their birthing preparedness. iv • Theme 3: Participants provided suggestions for midwives to facilitate their birthing process preparedness. Recommendations were made for midwives and managers, nursing education, research and limitations of the study were outlined. To comply with trustworthiness, this study adopted Lincoln and Guba’s Model of trustworthiness. The ethical principles that guided this study with human participants were the principles of respect for persons, beneficence, non-maleficence and justice. , Thesis (MA) -- Faculty of Health Sciences, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Dlamini, Xolani
- Date: 2022-04
- Subjects: Birthparents , Nelson Mandela Bay Health District
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/58815 , vital:60126
- Description: The birthing process is a challenging, unpredictable yet a beautiful life event for birthing women, requiring reasonable birthing process preparedness on birthing woman to enhance her cooperation during the birthing process. Often first-time mothers lack their own frame of reference regarding the birthing process to improve their birthing process preparedness. As an alternative they are reliant on that of other people with birthing process experiences or on what they are told by midwives. The purpose of this study was to understand how was the preparedness of the birthing process of first-time mothers in the public obstetric units of the NMBHD. Thus, an indication of how ready were they, when the labour started. The objectives of the study were as follows, to: • explore and describe the birthing process preparedness of first-time mothers in the public obstetric units of the NMBHD and • formulate recommendations for midwives and nurse managers that would aid them in facilitating the birthing process preparedness of first-time mothers in public obstetric units in the NMBHD. The study adopted a qualitative research design with exploratory, descriptive and contextual approach. The research population were first-time mothers who had booked and delivered in any of the obstetric units in the NMBHD. The convenience, non-probability sampling methods were used in selecting the first-time mothers who met the inclusion criteria. Envisaged sample size was 21 participants but also depending on data saturation. Sixteen participants were ultimately interviewed but only fifteen of those interviews were used. The data collection method used was one-on-one semi-structured interviews which were captured on a digital voice-recorder. The thematic method of data analysis was used to analyse data from the interviews. Three main themes emerged from the data analysis: • Theme 1: Participants shared their experiences regarding the birthing process and their birthing process preparedness. • Theme 2: Participants expressed having had varied experiences from factors that had influenced their birthing preparedness. iv • Theme 3: Participants provided suggestions for midwives to facilitate their birthing process preparedness. Recommendations were made for midwives and managers, nursing education, research and limitations of the study were outlined. To comply with trustworthiness, this study adopted Lincoln and Guba’s Model of trustworthiness. The ethical principles that guided this study with human participants were the principles of respect for persons, beneficence, non-maleficence and justice. , Thesis (MA) -- Faculty of Health Sciences, 2022
- Full Text:
- Date Issued: 2022-04
Bootstrap-based tolerance intervals for nested two-way random effects models
- Authors: Erasmus, Christopher Daniel
- Date: 2022-04
- Subjects: Mathematical statistics-South Africa , Multilevel models
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/55573 , vital:53331
- Description: Variance component, or random effects, models are frequently used by manufacturers to model the variance present in a manufacturing process. By applying tolerance intervals to variance component models, manufacturers are able to set upper and lower limits to monitor the variance within a process. Existing methods for constructing tolerance intervals are constrained by the necessity for data to be normally distributed. Recently, non-parametric bootstrap-based methods were developed by Deyzel (2018) to obtain α-expectation and (α, β) two-sided tolerance intervals for the two-way nested random effects model. Classical and non-parametric methods for obtaining tolerance intervals for the one way random effects model have been assessed in accordance with Rebafka et al. (2007). The present study assesses and compares classical, Bayesian and non-parametric methods for obtaining tolerance intervals for the two-way nested random effects model under different assumptions of the underlying distribution. Results show that the non-parametric methods provided relatively narrow intervals, and generally retain the nominal content and guarantee levels, regardless of the underlying distribution , Thesis (MSc) -- Faculty of Science, Mathematical Statistics , 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Erasmus, Christopher Daniel
- Date: 2022-04
- Subjects: Mathematical statistics-South Africa , Multilevel models
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/55573 , vital:53331
- Description: Variance component, or random effects, models are frequently used by manufacturers to model the variance present in a manufacturing process. By applying tolerance intervals to variance component models, manufacturers are able to set upper and lower limits to monitor the variance within a process. Existing methods for constructing tolerance intervals are constrained by the necessity for data to be normally distributed. Recently, non-parametric bootstrap-based methods were developed by Deyzel (2018) to obtain α-expectation and (α, β) two-sided tolerance intervals for the two-way nested random effects model. Classical and non-parametric methods for obtaining tolerance intervals for the one way random effects model have been assessed in accordance with Rebafka et al. (2007). The present study assesses and compares classical, Bayesian and non-parametric methods for obtaining tolerance intervals for the two-way nested random effects model under different assumptions of the underlying distribution. Results show that the non-parametric methods provided relatively narrow intervals, and generally retain the nominal content and guarantee levels, regardless of the underlying distribution , Thesis (MSc) -- Faculty of Science, Mathematical Statistics , 2022
- Full Text:
- Date Issued: 2022-04
Cannabidiol: extraction and purification using flow Chemistry
- Authors: Bopape, Karabo
- Date: 2022-04
- Subjects: Supercritical fluid extraction -- South Africa , Cannabis -- Therapeutic use
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/55723 , vital:53410
- Description: cannabinoids are of growing interest in research and pharmaceutical applications. Cannabidiol, which is a non-psychoactive cannabinoid, has many pharmaceutical applications. The current and main source of cannabidiol and other cannabinoids is from cannabis and hemp extractions. Current extraction methods involve the use of conventional solvent extraction, which employs the use of organic solvents, in some cases along with mechanical assistance from various equipment. Alternatively, another widely used extraction method is the use of supercritical extraction fluids (SC-CO2 being the most common). An alternative method, which uses chemical synthesis to derivatize cannabidiol to form an intermediate, which is crystalline and can easily be isolated from the extract; the crystalline intermediate can then be deprotected back to pure cannabidiol. In this research, we investigated and adapted the crystallisation method (originally employed by Adams) into continuous flow. In this research, hemp extracts and oilsrich in CBD were used as the source for cannabidiol. This synthesis was adapted into microreactors to synthesise the crystalline intermediate ester product (cannabidiol-3,5-bis-benzoate) which was subsequently reacted in a saponification ester hydrolysis to convert back and isolate pure CBD using continuous flow microreactor technology. Chapter one gives a comprehensive literature review and background on cannabidiol, along with its chemistry and pharmacological benefits in addition to a brief introduction to continuous flow technology with its advantages. Chapter two details the experimental procedures utilised for both batch and continuous flow syntheses. The continuous flow synthesis and subsequent hydrolysis of the ester intermediate, which shows the improvements in comparison to batch; giving higher product recovery (63% CBD), in shorter reaction times (2.5 min for CBD bis-benzoate; 30 min for CBD) is subsequently presented. This is expanded in chapter three with detailed discussions of the results attained during the continuous flow. The concluding remarks, the impact of this study and future work are elucidated in chapter four. , Thesis (MSc) -- Faculty of Science, Biomolecular and Chemical Sciences, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Bopape, Karabo
- Date: 2022-04
- Subjects: Supercritical fluid extraction -- South Africa , Cannabis -- Therapeutic use
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/55723 , vital:53410
- Description: cannabinoids are of growing interest in research and pharmaceutical applications. Cannabidiol, which is a non-psychoactive cannabinoid, has many pharmaceutical applications. The current and main source of cannabidiol and other cannabinoids is from cannabis and hemp extractions. Current extraction methods involve the use of conventional solvent extraction, which employs the use of organic solvents, in some cases along with mechanical assistance from various equipment. Alternatively, another widely used extraction method is the use of supercritical extraction fluids (SC-CO2 being the most common). An alternative method, which uses chemical synthesis to derivatize cannabidiol to form an intermediate, which is crystalline and can easily be isolated from the extract; the crystalline intermediate can then be deprotected back to pure cannabidiol. In this research, we investigated and adapted the crystallisation method (originally employed by Adams) into continuous flow. In this research, hemp extracts and oilsrich in CBD were used as the source for cannabidiol. This synthesis was adapted into microreactors to synthesise the crystalline intermediate ester product (cannabidiol-3,5-bis-benzoate) which was subsequently reacted in a saponification ester hydrolysis to convert back and isolate pure CBD using continuous flow microreactor technology. Chapter one gives a comprehensive literature review and background on cannabidiol, along with its chemistry and pharmacological benefits in addition to a brief introduction to continuous flow technology with its advantages. Chapter two details the experimental procedures utilised for both batch and continuous flow syntheses. The continuous flow synthesis and subsequent hydrolysis of the ester intermediate, which shows the improvements in comparison to batch; giving higher product recovery (63% CBD), in shorter reaction times (2.5 min for CBD bis-benzoate; 30 min for CBD) is subsequently presented. This is expanded in chapter three with detailed discussions of the results attained during the continuous flow. The concluding remarks, the impact of this study and future work are elucidated in chapter four. , Thesis (MSc) -- Faculty of Science, Biomolecular and Chemical Sciences, 2022
- Full Text:
- Date Issued: 2022-04
Cape Vultures (Gyps coprotheres) and the threat of wind farms: a race to extinction?
- Authors: Brooke, Francis Rae
- Date: 2022-04
- Subjects: Wind Turbines --Blades --Materials , Gyps --South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/55910 , vital:54399
- Description: The development of wind energy is increasing globally and is often considered more environmentally friendly when compared to fossil fuel technologies. However, one of the ecological drawbacks of wind energy are the collisions of wildlife with turbine blades. In addition, the resulting anthropogenic landscape transformation can negatively impact populations. The Cape Vulture (Gyps coprotheres), a large endangered southern African endemic species, thus may be at risk from turbine development. The species has decreased dramatically in the past 50 years and understanding how additional mortalities from wind turbine impacts affect the population is needed to ensure effective conservation efforts. This study aimed to determine the population response to this emerging threat. This study first reviewed the species-, site- and wind farm- specific traits that make Gyps species vulnerable to collision with wind energy infrastructure. It examined the monitoring practices employed during the pre- and post-construction phase and mitigation measures in South Africa and compared it with international standards. Furthermore, wind energy development may disrupt landscape connectivity and understanding which, and how habitat patches are used is needed. Using network theory combined with telemetry data from tagged individuals across three age classes, habitat patch use was identified. Further, environmental variables associated with identified habitat patches were identified. Additionally, considering the wind energy industry is expanding in South Africa, exploring how the Cape Vulture population will respond to this novel and emerging threat may aid future conservation management plans. Therefore, using a population viability analysis approach, the study explored how present and future wind turbine mortality scenarios impact the Cape Vulture population and how the population will respond to increased wind turbine development. , Thesis (PhD) -- Faculty of Science, School of Environmental Sciences, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Brooke, Francis Rae
- Date: 2022-04
- Subjects: Wind Turbines --Blades --Materials , Gyps --South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/55910 , vital:54399
- Description: The development of wind energy is increasing globally and is often considered more environmentally friendly when compared to fossil fuel technologies. However, one of the ecological drawbacks of wind energy are the collisions of wildlife with turbine blades. In addition, the resulting anthropogenic landscape transformation can negatively impact populations. The Cape Vulture (Gyps coprotheres), a large endangered southern African endemic species, thus may be at risk from turbine development. The species has decreased dramatically in the past 50 years and understanding how additional mortalities from wind turbine impacts affect the population is needed to ensure effective conservation efforts. This study aimed to determine the population response to this emerging threat. This study first reviewed the species-, site- and wind farm- specific traits that make Gyps species vulnerable to collision with wind energy infrastructure. It examined the monitoring practices employed during the pre- and post-construction phase and mitigation measures in South Africa and compared it with international standards. Furthermore, wind energy development may disrupt landscape connectivity and understanding which, and how habitat patches are used is needed. Using network theory combined with telemetry data from tagged individuals across three age classes, habitat patch use was identified. Further, environmental variables associated with identified habitat patches were identified. Additionally, considering the wind energy industry is expanding in South Africa, exploring how the Cape Vulture population will respond to this novel and emerging threat may aid future conservation management plans. Therefore, using a population viability analysis approach, the study explored how present and future wind turbine mortality scenarios impact the Cape Vulture population and how the population will respond to increased wind turbine development. , Thesis (PhD) -- Faculty of Science, School of Environmental Sciences, 2022
- Full Text:
- Date Issued: 2022-04
Career counselling in the context of Industry 4.0: A systematic literature review
- Authors: Chintokoma, Kudzai Ashley
- Date: 2022-04
- Subjects: Career development , Career changes
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/57589 , vital:58102
- Description: The researcher’s main aim was to summarise and evaluate the existing body of knowledge of career counselling practices, theory and models that can be used as a tool to help individuals cope or manage change in a contemporary work environment. The findings show that the world of work has changed due to technological advancement associated with Industry 4.0, resulting in careers becoming short term. More so, given the increasing speed at which current occupations are changing, people are forced to familiarize themselves with new occupations and industries that might offer new employment opportunities and career prospects. Based on a systematic literature review, the study holds the practical implication that with the help of evolving career counselling practices and HR processes, organisations can help employees attain a meaningful career and wellbeing in the digital era, through paying more attention to enabling interventions that help individuals develop self-regulatory future fit career self-management capabilities. This support system can be of assistance if they understand how employees’ identity in the demonstration of self-management capability can be developed and sustained both in the short and long run. Overall, the literature was effective and quite convincing in its call to discuss the pressing issues that come as a result of industry 4.0. The proposition is that career support should be promoted more and become an important policy within organisations in the digital era. , Thesis (MA) -- Faculty of Business and Economic science, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Chintokoma, Kudzai Ashley
- Date: 2022-04
- Subjects: Career development , Career changes
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/57589 , vital:58102
- Description: The researcher’s main aim was to summarise and evaluate the existing body of knowledge of career counselling practices, theory and models that can be used as a tool to help individuals cope or manage change in a contemporary work environment. The findings show that the world of work has changed due to technological advancement associated with Industry 4.0, resulting in careers becoming short term. More so, given the increasing speed at which current occupations are changing, people are forced to familiarize themselves with new occupations and industries that might offer new employment opportunities and career prospects. Based on a systematic literature review, the study holds the practical implication that with the help of evolving career counselling practices and HR processes, organisations can help employees attain a meaningful career and wellbeing in the digital era, through paying more attention to enabling interventions that help individuals develop self-regulatory future fit career self-management capabilities. This support system can be of assistance if they understand how employees’ identity in the demonstration of self-management capability can be developed and sustained both in the short and long run. Overall, the literature was effective and quite convincing in its call to discuss the pressing issues that come as a result of industry 4.0. The proposition is that career support should be promoted more and become an important policy within organisations in the digital era. , Thesis (MA) -- Faculty of Business and Economic science, 2022
- Full Text:
- Date Issued: 2022-04
Chemical analysis of selected Eastern Cape medicinal plants
- Authors: Mahanjana, Lungelwa
- Date: 2022-04
- Subjects: Medicinal plants -- South Africa --Eastern Cape , Traditional medicine --South Africa -- Eastern Cape Maps
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/55976 , vital:54560
- Description: In the rural parts of the Eastern Cape Province of South Africa, the use of medicinal plants to treat or manage diseases, including those associated with diabetes and HIV, is a common practice. However, the phytochemistry, safety and efficacy of these medicinal plants remain less investigated. Based on available traditional medicinal knowledge (through traditional healers, university library resources, ethnobotanical and science journals and other internet resources), traditional uses and availability, three plant species, namely Bulbine latifolia L. Wild, Dicerothamnus rhinocerotis Koek. and Olea europaea subsp. africana (Mill.) P.S. Green were selected and investigated for their hytoconstituents and biological effects. Phytochemical screening of the three medicinal plants was carried out quantitatively and qualitatively using spectrophotometric methods. Chemical profiling of the crude methanol extracts of all the plant species was successfully done by high-performance thin layer chromatography (HPTLC) and tentative identification of the secondary metabolites was achieved by liquid chromatography–mass spectrometry (LCMS). Cytotoxicity effect investigations on the crude extracts of the three species was done using the 3-[4,5- dimethylthiazole-2-yl]-2,5- hiphenyltetrazolium bromide (MTT) assay against HeLa cervical cancer cells. Isolation and purification of single compounds was done using chromatographic techniques (column chromatography (CC), and preparative thin-layer chromatography (PTLC)). Characterisation of single compounds was achieved using spectroscopic techniques such as Nuclear Magnetic Resonance (NMR), High Resolution Mass Spectrometry (HRMS), Ultra Violet Spectroscopy (UV-vis), Fourier-Transformed Infra-Red Spectroscopy (FTIR) and Single-Crystal X-ray Diffraction (XRD). For the first time from the methanol crude extract of the tubers of B. latifolia, the crystal structure of the phenylanthraquinone, knipholone (3.12) (1-(3-acetyl-2,6- dihydroxy-4- methoxyphenyl)-4,5-dihydroxy-2-methylanthraquinone), was isolated and elucidated along with its derivatives, isoknipholone (3.14), knipholone-6’-methyl (3.27). Moreover, two new compounds, (M)-8-O-β-D-glucopyranosyl-10’-α-L-rhamnopyranosyl-1,1',8',10'-tetrahydroxy 3,3'-dimethyl-[10,7'-bianthracene]-4,9,9'(10'H)-trione (3.23a) and (P)- 8-O-β-D glucopyranosyl-10’-α-L-rhamnopyranosyl-1,1',8',10'-tetrahydroxy-3,3'-dimethyl-[10,7'- bianthracene]-4,9,9'(10'H)-trione (3.23b) were isolated. , Thesis (PhD) -- Faculty of Science, School of Biomecular and Chemical Sciences, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Mahanjana, Lungelwa
- Date: 2022-04
- Subjects: Medicinal plants -- South Africa --Eastern Cape , Traditional medicine --South Africa -- Eastern Cape Maps
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/55976 , vital:54560
- Description: In the rural parts of the Eastern Cape Province of South Africa, the use of medicinal plants to treat or manage diseases, including those associated with diabetes and HIV, is a common practice. However, the phytochemistry, safety and efficacy of these medicinal plants remain less investigated. Based on available traditional medicinal knowledge (through traditional healers, university library resources, ethnobotanical and science journals and other internet resources), traditional uses and availability, three plant species, namely Bulbine latifolia L. Wild, Dicerothamnus rhinocerotis Koek. and Olea europaea subsp. africana (Mill.) P.S. Green were selected and investigated for their hytoconstituents and biological effects. Phytochemical screening of the three medicinal plants was carried out quantitatively and qualitatively using spectrophotometric methods. Chemical profiling of the crude methanol extracts of all the plant species was successfully done by high-performance thin layer chromatography (HPTLC) and tentative identification of the secondary metabolites was achieved by liquid chromatography–mass spectrometry (LCMS). Cytotoxicity effect investigations on the crude extracts of the three species was done using the 3-[4,5- dimethylthiazole-2-yl]-2,5- hiphenyltetrazolium bromide (MTT) assay against HeLa cervical cancer cells. Isolation and purification of single compounds was done using chromatographic techniques (column chromatography (CC), and preparative thin-layer chromatography (PTLC)). Characterisation of single compounds was achieved using spectroscopic techniques such as Nuclear Magnetic Resonance (NMR), High Resolution Mass Spectrometry (HRMS), Ultra Violet Spectroscopy (UV-vis), Fourier-Transformed Infra-Red Spectroscopy (FTIR) and Single-Crystal X-ray Diffraction (XRD). For the first time from the methanol crude extract of the tubers of B. latifolia, the crystal structure of the phenylanthraquinone, knipholone (3.12) (1-(3-acetyl-2,6- dihydroxy-4- methoxyphenyl)-4,5-dihydroxy-2-methylanthraquinone), was isolated and elucidated along with its derivatives, isoknipholone (3.14), knipholone-6’-methyl (3.27). Moreover, two new compounds, (M)-8-O-β-D-glucopyranosyl-10’-α-L-rhamnopyranosyl-1,1',8',10'-tetrahydroxy 3,3'-dimethyl-[10,7'-bianthracene]-4,9,9'(10'H)-trione (3.23a) and (P)- 8-O-β-D glucopyranosyl-10’-α-L-rhamnopyranosyl-1,1',8',10'-tetrahydroxy-3,3'-dimethyl-[10,7'- bianthracene]-4,9,9'(10'H)-trione (3.23b) were isolated. , Thesis (PhD) -- Faculty of Science, School of Biomecular and Chemical Sciences, 2022
- Full Text:
- Date Issued: 2022-04
Classification and clustering based methods for outlier detection of solar resource data
- Authors: Abrahams, Waldo
- Date: 2022-04
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/55423 , vital:51996
- Description: Almost 90% of the primary global energy demand is serviced from the burning of fossil fuels (Abas, Kalair & Khan, 2015). Owing to the detrimental environmental impact of this, a global energy transition to the use of renewable energy, including solar energy, is needed (Gielen et al., 2019). An important aspect that inhibits the growth of solar energy is accurate solar resource data. Such data is needed because knowledge of the future reliability and quality of energy production is required to analyse a system’s performance and determine financial implications (Sengupta et al., 2017). Existing methods used to detect outliers in solar resource data do not efficiently identify outliers and an accurate and robust approach is required (Eastwood, 2019). Using simulated and real-world data, this study investigates the use of several classification methods, along with a two-stage clustering-classification approach to accurately identify outliers in solar resource data. The Treebag method proves to be an adequate outlier detection method for solar resource data. , Thesis (MSc) -- Faculty of Science, School of Computer Science, Mathematics, Physics and Statistics, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Abrahams, Waldo
- Date: 2022-04
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/55423 , vital:51996
- Description: Almost 90% of the primary global energy demand is serviced from the burning of fossil fuels (Abas, Kalair & Khan, 2015). Owing to the detrimental environmental impact of this, a global energy transition to the use of renewable energy, including solar energy, is needed (Gielen et al., 2019). An important aspect that inhibits the growth of solar energy is accurate solar resource data. Such data is needed because knowledge of the future reliability and quality of energy production is required to analyse a system’s performance and determine financial implications (Sengupta et al., 2017). Existing methods used to detect outliers in solar resource data do not efficiently identify outliers and an accurate and robust approach is required (Eastwood, 2019). Using simulated and real-world data, this study investigates the use of several classification methods, along with a two-stage clustering-classification approach to accurately identify outliers in solar resource data. The Treebag method proves to be an adequate outlier detection method for solar resource data. , Thesis (MSc) -- Faculty of Science, School of Computer Science, Mathematics, Physics and Statistics, 2022
- Full Text:
- Date Issued: 2022-04
Climate Change and Rural Livelihoods: A Case of Insiza District, Matabeleland
- Authors: Nyoni, Sibusisiwe Ruth
- Date: 2022-04
- Subjects: Climatic change -- Zimbabwe
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/58112 , vital:58579
- Description: Owen Jones’ famous article “Why don’t we treat climate change with the same urgency as Coronavirus” puts forward an intriguing dimension to the climate change phenomenon. Despite the threat it presents to millions of people as well as the world economy, little has been done to prevent countries from being overwhelmed by its effects. Due to the fact that climate change is happening now, the purpose of this study provides insight into climate change and rural livelihoods in Insiza district, Matabeleland. In this study, an interpretivist paradigm was adopted as it gave the researcher adequate information that embodies an account of the participants’ understanding of livelihood assets. The qualitative research approach was adopted as it allowed the researcher to classify the findings into broad themes in order to tell a story. Farmers in Insiza district who depend on agriculture for subsistence were interviewed to provide insight into this phenomenon. The findings of the study revealed that climate stresses, non-climate stresses as well as institutional constraints together contribute to the vulnerability of farmers. Additionally, the findings unveiled that the inconsistent weather patterns as well as the recurrent droughts in the area have pushed most farmers to find alternative means of livelihood. Therefore, farmers over time have resorted to other self-taught means of making a living such as building, small scale mining, buying and selling of clothing items, running grocery stores, baking, owning backyard vegetable gardens, welding, fishing, selling firewood and growing chickens for sale. On the same note the findings showed that farmers in Insiza district employ different coping strategies in attempting to deal with climate change. The most common method in the area of study is conservation farming which has to do with digging pits to store water. More so, the findings displayed that NGOs have been of great assistance in equipping farmers at such a time as this. The study recommends that the government needs to ensure financial and institutional mechanisms to assist the Insiza community. Also, the NGOs must continue to support the communities through equipping them to diversify their portfolios and through developing tailor made capacity building programmes. To the farmers it is recommended that they continue to move in unity and form relationships with other farmers from other districts and provinces so that they can continue to share information. , Thesis (MA) -- Faculty of Business and Economic science, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Nyoni, Sibusisiwe Ruth
- Date: 2022-04
- Subjects: Climatic change -- Zimbabwe
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/58112 , vital:58579
- Description: Owen Jones’ famous article “Why don’t we treat climate change with the same urgency as Coronavirus” puts forward an intriguing dimension to the climate change phenomenon. Despite the threat it presents to millions of people as well as the world economy, little has been done to prevent countries from being overwhelmed by its effects. Due to the fact that climate change is happening now, the purpose of this study provides insight into climate change and rural livelihoods in Insiza district, Matabeleland. In this study, an interpretivist paradigm was adopted as it gave the researcher adequate information that embodies an account of the participants’ understanding of livelihood assets. The qualitative research approach was adopted as it allowed the researcher to classify the findings into broad themes in order to tell a story. Farmers in Insiza district who depend on agriculture for subsistence were interviewed to provide insight into this phenomenon. The findings of the study revealed that climate stresses, non-climate stresses as well as institutional constraints together contribute to the vulnerability of farmers. Additionally, the findings unveiled that the inconsistent weather patterns as well as the recurrent droughts in the area have pushed most farmers to find alternative means of livelihood. Therefore, farmers over time have resorted to other self-taught means of making a living such as building, small scale mining, buying and selling of clothing items, running grocery stores, baking, owning backyard vegetable gardens, welding, fishing, selling firewood and growing chickens for sale. On the same note the findings showed that farmers in Insiza district employ different coping strategies in attempting to deal with climate change. The most common method in the area of study is conservation farming which has to do with digging pits to store water. More so, the findings displayed that NGOs have been of great assistance in equipping farmers at such a time as this. The study recommends that the government needs to ensure financial and institutional mechanisms to assist the Insiza community. Also, the NGOs must continue to support the communities through equipping them to diversify their portfolios and through developing tailor made capacity building programmes. To the farmers it is recommended that they continue to move in unity and form relationships with other farmers from other districts and provinces so that they can continue to share information. , Thesis (MA) -- Faculty of Business and Economic science, 2022
- Full Text:
- Date Issued: 2022-04
Combined Additive Manufacturing and Machining for Large-Scale Prototyping for Minimising Material Wastage
- Authors: Taylor, Kyle Joshua
- Date: 2022-04
- Subjects: Prototypes, Engineering
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/58484 , vital:59645
- Description: This research project aimed to develop a combined additive and subtractive manufacturing platform capable of rapidly producing large-scale prototypes for minimising material wastage. A design conceptualisation process led to the design and development of a system to deposit the additive material. The developed system was mounted to a large-scale CNC milling machine. This combination of additive and subtractive manufacturing into a single system integrated the separate benefits of the two independent technologies. Mastercam was selected as the preferred CAD/CAM software package to generate toolpaths for the additive and subtractive processes. The Beckhoff HMI provided a user-friendly interface to interpret the generated G-code files, set the Work Coordinate System, and control user-defined parameters such as the feed rate. An in-depth statistical analysis of the developed platform's dimensional accuracy, repeatability, stability, and material wastage was performed. In addition, the effects of the independent adjustment of the subtractive manufacturing process parameters such as the spindle speed, feed rate, depth of cut and stepover distance were considered. Finally, a cycle time comparison was performed in producing a working prototype between the developed HM system and a commercially available 3D printer. This research provided a platform for further investigation into the ever-expanding applications and benefits of rapid prototyping. , Thesis (MA) -- Faculty of Engineering, the Built Environment, and Technology, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Taylor, Kyle Joshua
- Date: 2022-04
- Subjects: Prototypes, Engineering
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/58484 , vital:59645
- Description: This research project aimed to develop a combined additive and subtractive manufacturing platform capable of rapidly producing large-scale prototypes for minimising material wastage. A design conceptualisation process led to the design and development of a system to deposit the additive material. The developed system was mounted to a large-scale CNC milling machine. This combination of additive and subtractive manufacturing into a single system integrated the separate benefits of the two independent technologies. Mastercam was selected as the preferred CAD/CAM software package to generate toolpaths for the additive and subtractive processes. The Beckhoff HMI provided a user-friendly interface to interpret the generated G-code files, set the Work Coordinate System, and control user-defined parameters such as the feed rate. An in-depth statistical analysis of the developed platform's dimensional accuracy, repeatability, stability, and material wastage was performed. In addition, the effects of the independent adjustment of the subtractive manufacturing process parameters such as the spindle speed, feed rate, depth of cut and stepover distance were considered. Finally, a cycle time comparison was performed in producing a working prototype between the developed HM system and a commercially available 3D printer. This research provided a platform for further investigation into the ever-expanding applications and benefits of rapid prototyping. , Thesis (MA) -- Faculty of Engineering, the Built Environment, and Technology, 2022
- Full Text:
- Date Issued: 2022-04
Constructing an online serviceScape for the funeral industry
- Authors: Coetzee, Cornelis Albertus
- Date: 2022-04
- Subjects: Funeral supplies industry , Funeral service , Service industries -- Marketing
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/57611 , vital:58186
- Description: An online servicescape serves as a moderator for excellence in Customer Relationship Management (CRM). The study approached the online servicescape from the perspective of the funeral industry. Nowhere is the relevance of an online servicescape more apparent than in an industry which is firstly, unsought, and secondly, perceived as dismal. During the process of arranging a funeral, the customer is experiencing an unusual purchase situation as it is a purchase that cannot be avoided. The possibility also exists that the customer most likely did not seek information about a funeral home prior to the demise of a loved one. A third contributing factor is the emotional state of the customer which will, in a time of bereavement, have a strong impact on the rational decision-making process. Considering these conditions, the study approached the online servicescape based on three elements, namely Search Engine Optimisation, perceived value, and perceived usefulness of the online servicescape. These elements contribute to trust in the funeral home’s online offerings, which could influence the purchase outcomes significantly. The aim of the study was to construct a functional servicescape for an unsought business such as a funeral home, hence contributing significantly to the CRM body of knowledge as it was determined that this has not been explored before from an academic perspective. A quantitative, exploratory methodology was implemented. The exploration is depended on Bitner's (1992a:60) seminal model of servicescapes, Harris and Goode's (2010:230-243) model for online servicescapes, and the key constructs of Simon's (1996:141-142) Design Theory to provide a methodological basis with which to construct the key elements for a funeral industry based online servicescape. The data collection process followed a twostep process. A content analysis was conducted on existing websites from five English speaking countries, followed by a survey that largely reflected the content analysis variables to gain customer insights. The data was analysed using a descriptive analysis process. v It was determined that customers would trust a functional servicescape, which will most probably lead to a purchase situation. However, customers also indicated the opposite if they detect anything on the website that might lead to distrust. It was therefore concluded that it is imperative for a funeral home to ensure that their online servicescape meets the functional needs of customers in order ensure trust and purchase intention. , Thesis (PhD) -- Faculty of Business and Economic science, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Coetzee, Cornelis Albertus
- Date: 2022-04
- Subjects: Funeral supplies industry , Funeral service , Service industries -- Marketing
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/57611 , vital:58186
- Description: An online servicescape serves as a moderator for excellence in Customer Relationship Management (CRM). The study approached the online servicescape from the perspective of the funeral industry. Nowhere is the relevance of an online servicescape more apparent than in an industry which is firstly, unsought, and secondly, perceived as dismal. During the process of arranging a funeral, the customer is experiencing an unusual purchase situation as it is a purchase that cannot be avoided. The possibility also exists that the customer most likely did not seek information about a funeral home prior to the demise of a loved one. A third contributing factor is the emotional state of the customer which will, in a time of bereavement, have a strong impact on the rational decision-making process. Considering these conditions, the study approached the online servicescape based on three elements, namely Search Engine Optimisation, perceived value, and perceived usefulness of the online servicescape. These elements contribute to trust in the funeral home’s online offerings, which could influence the purchase outcomes significantly. The aim of the study was to construct a functional servicescape for an unsought business such as a funeral home, hence contributing significantly to the CRM body of knowledge as it was determined that this has not been explored before from an academic perspective. A quantitative, exploratory methodology was implemented. The exploration is depended on Bitner's (1992a:60) seminal model of servicescapes, Harris and Goode's (2010:230-243) model for online servicescapes, and the key constructs of Simon's (1996:141-142) Design Theory to provide a methodological basis with which to construct the key elements for a funeral industry based online servicescape. The data collection process followed a twostep process. A content analysis was conducted on existing websites from five English speaking countries, followed by a survey that largely reflected the content analysis variables to gain customer insights. The data was analysed using a descriptive analysis process. v It was determined that customers would trust a functional servicescape, which will most probably lead to a purchase situation. However, customers also indicated the opposite if they detect anything on the website that might lead to distrust. It was therefore concluded that it is imperative for a funeral home to ensure that their online servicescape meets the functional needs of customers in order ensure trust and purchase intention. , Thesis (PhD) -- Faculty of Business and Economic science, 2022
- Full Text:
- Date Issued: 2022-04
Credit risk management impact on loan performance in development finance institutions in South Africa
- Lekhelebana, Letlatsa George
- Authors: Lekhelebana, Letlatsa George
- Date: 2022-04
- Subjects: Development finance institutions , Credit -- Management -- South Africa
- Language: English
- Type: Doctoral's theses , text
- Identifier: http://hdl.handle.net/10948/57698 , vital:58217
- Description: Development Finance Institutions ( play an important role in being a catalyst for economic development and growth where they operate. TUHF Group operates as a niche commercial property D FI funding entrepreneurs that seek to bring to market properties that deliver multi let housing units. This also deals with the pro blem of the lack of housing that South Africa has. For DFIs to operate optimally and be financially sustainable , they need to source funding from either shareholders or the financial markets. Financial markets require that the DFIs operate in a profitable manner to qualify for funding and this is also driven by the way the DFI manages the loan book’s integrity. This study examines the relationship between credit risk management policy, processes and procedures in practice and the TUHF Group and their impa ct on the performance of the loan book. In order that the research aim and objectives are fulfilled, and the research question answered, the study undertook an extensive review of existing literature on DFIs, the impact on economic development and growt h, the impact of badly performing loan books on the performance of companies and how this is impacted on by credit management structures, policies and procedures. An empirical study was conducted through the collection of primary data from the internal doc uments at TUHF Group and among some of the staff members at TUHF through a structured interviews based on open ended questions. The research revealed that there is indeed a link between the credit risk management processes and procedures at TUHF and the performance of the loan book, the findings indicated that the current policy and procedures is not sufficient for a well performing loan book and the pr imary data showed worsening performance of the loan book over time. These findings further indicate a requirement for TUHF to improve the credit policies and architecture for a sustainable financial performance in future. , Thesis (MA) -- Faculty of Business and Economic science, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Lekhelebana, Letlatsa George
- Date: 2022-04
- Subjects: Development finance institutions , Credit -- Management -- South Africa
- Language: English
- Type: Doctoral's theses , text
- Identifier: http://hdl.handle.net/10948/57698 , vital:58217
- Description: Development Finance Institutions ( play an important role in being a catalyst for economic development and growth where they operate. TUHF Group operates as a niche commercial property D FI funding entrepreneurs that seek to bring to market properties that deliver multi let housing units. This also deals with the pro blem of the lack of housing that South Africa has. For DFIs to operate optimally and be financially sustainable , they need to source funding from either shareholders or the financial markets. Financial markets require that the DFIs operate in a profitable manner to qualify for funding and this is also driven by the way the DFI manages the loan book’s integrity. This study examines the relationship between credit risk management policy, processes and procedures in practice and the TUHF Group and their impa ct on the performance of the loan book. In order that the research aim and objectives are fulfilled, and the research question answered, the study undertook an extensive review of existing literature on DFIs, the impact on economic development and growt h, the impact of badly performing loan books on the performance of companies and how this is impacted on by credit management structures, policies and procedures. An empirical study was conducted through the collection of primary data from the internal doc uments at TUHF Group and among some of the staff members at TUHF through a structured interviews based on open ended questions. The research revealed that there is indeed a link between the credit risk management processes and procedures at TUHF and the performance of the loan book, the findings indicated that the current policy and procedures is not sufficient for a well performing loan book and the pr imary data showed worsening performance of the loan book over time. These findings further indicate a requirement for TUHF to improve the credit policies and architecture for a sustainable financial performance in future. , Thesis (MA) -- Faculty of Business and Economic science, 2022
- Full Text:
- Date Issued: 2022-04
Design, Development and Testing of a Low-cost Sub-Joule μPPT for a PocketQube
- Authors: Bae, Ji Eun
- Date: 2022-04
- Subjects: Electric current converters , Pulse circuits , Plasma jets
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/58295 , vital:58953
- Description: Small satellites are unmanned spacecraft with small size and mass weighing less than 500kg. A small satellite called the CubeSat was created by two university professors to help students understand satellite design. The idea of small satellites caught on and they became popular due to their low cost, quick development time and easy deployment. The inexpensive nature of small satellites has helped lower the entry barrier to space and led to a movement called the “democratisation of space”. The popularity of small satellites has also caught the eye of private companies that recognise the potential of commercialising small satellite technologies. Nowadays, small satellites are being considered for more complex and challenging space missions. However for a small satellite to reach its full potential, it needs to be equipped with a proper propulsion system. Governments, space agencies, companies and universities around the world have started to research new innovative miniaturised space propulsion technologies. Nowadays, there are many newly developed miniaturised propulsion technologies available. The new propulsion systems are either sold by the companies and universities at a very high price, or research and development is closely guarded due to the potential commercial value of the propulsion system. Companies and universities have primarily focused on researching and developing top-of-the-line micro-propulsion devices to win lucrative research funds. This has resulted in a lack of research into cheap reliable micropropulsion as there have been no incentives for companies and universities to develop this area. As a result, fund-limited students and individuals have been left behind, defeating the purpose of small satellites. This dissertation focuses on designing and developing a low-cost sub-joule micro-PPT propulsion system for a PocketQube satellite. The first section covers the literature review, which looks at the different space propulsion technologies currently available. The next section covers the micro-PPT propulsion system’s mechanical and electrical design and development process. After the development process, the performance of the prototype is tested using various input parameters, as well as in vacuum conditions and over its lifetime. The test results show that the optimal performance is obtained with an input voltage supply of 5V at a pulse frequency of 0.5Hz, which achieves a minimal impulse bit v of 0.698μNs and thrust range of 0.349~1.071μN. In comparison to the STRaND-1 3U CubeSat’s PPT, performance data show that the developed μPPT propulsion system is a competitive propulsion solution, as it achieves more thrust with similar minimal impulse bit, using only one third of the power consumption. The μPPT propulsion system is able to produce 1980 shots so far, which is far lower relatively than other established PPTs due to the limitations resulting from capacitor failure. , Thesis (MA) -- Faculty of Engineering, the Built Environment, and Technology, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Bae, Ji Eun
- Date: 2022-04
- Subjects: Electric current converters , Pulse circuits , Plasma jets
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/58295 , vital:58953
- Description: Small satellites are unmanned spacecraft with small size and mass weighing less than 500kg. A small satellite called the CubeSat was created by two university professors to help students understand satellite design. The idea of small satellites caught on and they became popular due to their low cost, quick development time and easy deployment. The inexpensive nature of small satellites has helped lower the entry barrier to space and led to a movement called the “democratisation of space”. The popularity of small satellites has also caught the eye of private companies that recognise the potential of commercialising small satellite technologies. Nowadays, small satellites are being considered for more complex and challenging space missions. However for a small satellite to reach its full potential, it needs to be equipped with a proper propulsion system. Governments, space agencies, companies and universities around the world have started to research new innovative miniaturised space propulsion technologies. Nowadays, there are many newly developed miniaturised propulsion technologies available. The new propulsion systems are either sold by the companies and universities at a very high price, or research and development is closely guarded due to the potential commercial value of the propulsion system. Companies and universities have primarily focused on researching and developing top-of-the-line micro-propulsion devices to win lucrative research funds. This has resulted in a lack of research into cheap reliable micropropulsion as there have been no incentives for companies and universities to develop this area. As a result, fund-limited students and individuals have been left behind, defeating the purpose of small satellites. This dissertation focuses on designing and developing a low-cost sub-joule micro-PPT propulsion system for a PocketQube satellite. The first section covers the literature review, which looks at the different space propulsion technologies currently available. The next section covers the micro-PPT propulsion system’s mechanical and electrical design and development process. After the development process, the performance of the prototype is tested using various input parameters, as well as in vacuum conditions and over its lifetime. The test results show that the optimal performance is obtained with an input voltage supply of 5V at a pulse frequency of 0.5Hz, which achieves a minimal impulse bit v of 0.698μNs and thrust range of 0.349~1.071μN. In comparison to the STRaND-1 3U CubeSat’s PPT, performance data show that the developed μPPT propulsion system is a competitive propulsion solution, as it achieves more thrust with similar minimal impulse bit, using only one third of the power consumption. The μPPT propulsion system is able to produce 1980 shots so far, which is far lower relatively than other established PPTs due to the limitations resulting from capacitor failure. , Thesis (MA) -- Faculty of Engineering, the Built Environment, and Technology, 2022
- Full Text:
- Date Issued: 2022-04
Determining and its effects on perceptual motor skills of soccer players
- Authors: Van Niekerk, Tyra-lee
- Date: 2022-04
- Subjects: Soccer players , Perceptual-motor processes
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/58961 , vital:60251
- Description: Objectives: The influence of detraining on the perceptual motor skills of soccer players has been theorized, but not verified empirically (Farrow & Robertson, 2017). The aim of this study was to examine detraining and its effects on the perceptual-motor skills of soccer players by employing a three-week period of no training, immediately post-season. Method: To further examine the effects that three weeks of no training would have on the perceptual-motor and perceptual-cognitive abilities of soccer players, sixteen male club university soccer players (aged 21.10±2.69 years with 12.40±3.18 years of playing experience) participated in this single-cohort longitudinal observation study. The measurements were performed in the following order with sprint testing encompassing the 40-Meter Sprint Test, aerobic performance testing by use of Intermittent Yo-Yo Test (YYIR2), perceptual-motor testing which consisted of the Loughborough Soccer Passing Test and perceptual-cognitive testing undertaken by means of Video-based assessment. Results: A three-week period of no training showed no negligible effects of detraining on sprint performance (F(2, 30) = 1.43, p = .255, ƞp2 = .09), perceptual-motor performance (F(1, 15) = 2.52, p = .133, ƞp2 = .14) nor effects of detraining regarding perceptual-cognitive aptitudes (F(2, 30)= 0.28, p= .813, ƞp 2= .01 ). Results of the study did, however, suggest the potential for increasing aerobic performance (F(1, 15) = 6.17, p = .025, ƞp2 = .29). Additionally, the study results inferred that within Video-based assessment, university club soccer players may develop a response bias due to familiarity or repeated exposure to the testing procedures. Conclusions: Results from the study fail to comprehensively show the effects of detraining on male club university soccer players in all aspects of the perceptual-skill framework, after three weeks of no training. The researcher further discusses the effects of familiarity, repeated exposure and the robustness of these perceptual-cognitive and perceptual-motor abilities as possible reasons for the results returned. , Thesis (MA) -- Faculty of Health Sciences, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Van Niekerk, Tyra-lee
- Date: 2022-04
- Subjects: Soccer players , Perceptual-motor processes
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/58961 , vital:60251
- Description: Objectives: The influence of detraining on the perceptual motor skills of soccer players has been theorized, but not verified empirically (Farrow & Robertson, 2017). The aim of this study was to examine detraining and its effects on the perceptual-motor skills of soccer players by employing a three-week period of no training, immediately post-season. Method: To further examine the effects that three weeks of no training would have on the perceptual-motor and perceptual-cognitive abilities of soccer players, sixteen male club university soccer players (aged 21.10±2.69 years with 12.40±3.18 years of playing experience) participated in this single-cohort longitudinal observation study. The measurements were performed in the following order with sprint testing encompassing the 40-Meter Sprint Test, aerobic performance testing by use of Intermittent Yo-Yo Test (YYIR2), perceptual-motor testing which consisted of the Loughborough Soccer Passing Test and perceptual-cognitive testing undertaken by means of Video-based assessment. Results: A three-week period of no training showed no negligible effects of detraining on sprint performance (F(2, 30) = 1.43, p = .255, ƞp2 = .09), perceptual-motor performance (F(1, 15) = 2.52, p = .133, ƞp2 = .14) nor effects of detraining regarding perceptual-cognitive aptitudes (F(2, 30)= 0.28, p= .813, ƞp 2= .01 ). Results of the study did, however, suggest the potential for increasing aerobic performance (F(1, 15) = 6.17, p = .025, ƞp2 = .29). Additionally, the study results inferred that within Video-based assessment, university club soccer players may develop a response bias due to familiarity or repeated exposure to the testing procedures. Conclusions: Results from the study fail to comprehensively show the effects of detraining on male club university soccer players in all aspects of the perceptual-skill framework, after three weeks of no training. The researcher further discusses the effects of familiarity, repeated exposure and the robustness of these perceptual-cognitive and perceptual-motor abilities as possible reasons for the results returned. , Thesis (MA) -- Faculty of Health Sciences, 2022
- Full Text:
- Date Issued: 2022-04
Developing a socio- ecological framework for the restoration of estuaries using the Swartkops Estuary as a case study
- Authors: Tsipa, Vusumzi
- Date: 2022-04
- Subjects: Estuarine ecology -- South Africa -- Swartkops River Estuary , Ecosystem
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/59622 , vital:62208
- Description: The aim of this study was to develop and test a socio-ecological systems framework for the restoration of estuaries in South Africa using the Swartkops Estuary as a case study. This necessitated a review of existing SES frameworks that have been developed for use in other disciplines. As part of the newly developed framework, the Swartkops estuary condition was assessed using the Estuary Health Index to understand the present ecological state (PES) of the estuary following from the last assessment done in 2013/2014. The Estuary Health Index is a nationally accepted method of measuring the health of South African estuaries. The state of the societal system was assessed through field observations, engagements with estuary users on-site, insights provided by the Zwartkops Conservancy, and from recent literature. The potential for restoration of habitats for the purpose of carbon storage was also assessed as part of this study. The suitability of disturbed habitats for stimulating future salt marsh growth was investigated since an important incentive for restoration is blue carbon storage. This is important as blue carbon ecosystems offer great potential as a climate change mitigation measure through their ability to sequester carbon. This was done by evaluating plant cover and sediment characteristics at sites along the length of the estuary representing disturbed and undisturbed areas. The estuarine health score for the Swartkops Estuary was found to be 47 out of 100 translating to a PES Category D (largely modified estuary). The main problem in the estuary is water quality along with habitat loss and resource exploitation. The three Wastewater Treatment Works (WWTWs) located upstream of the estuary are the main drivers behind the decline in estuary health in addition to other threats to the water quality which are stormwater run-off inputs from the Motherwell canal and Markman canal. This study showed that the health of the estuary is on a negative trajectory towards a largely degraded estuary. Fishing, bait collection and the use of spiritual sites are the dominant vii ecosystem services used at the estuary. Through the assessment of the state of the societal system, the estuary was highlighted to be a major food source for many people living close to the estuary through subsistence fishing and bait collection for selling to recreational fishers. The estuary is also a health hazard to the very same people that depend on it for survival because of the poor water quality particularly high metal inputs from past and present nearby industrial activities. Restoration plans need to be developed in consideration of the estuary status quo that includes the societal system and the ecosystem services provided by the estuary. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Tsipa, Vusumzi
- Date: 2022-04
- Subjects: Estuarine ecology -- South Africa -- Swartkops River Estuary , Ecosystem
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/59622 , vital:62208
- Description: The aim of this study was to develop and test a socio-ecological systems framework for the restoration of estuaries in South Africa using the Swartkops Estuary as a case study. This necessitated a review of existing SES frameworks that have been developed for use in other disciplines. As part of the newly developed framework, the Swartkops estuary condition was assessed using the Estuary Health Index to understand the present ecological state (PES) of the estuary following from the last assessment done in 2013/2014. The Estuary Health Index is a nationally accepted method of measuring the health of South African estuaries. The state of the societal system was assessed through field observations, engagements with estuary users on-site, insights provided by the Zwartkops Conservancy, and from recent literature. The potential for restoration of habitats for the purpose of carbon storage was also assessed as part of this study. The suitability of disturbed habitats for stimulating future salt marsh growth was investigated since an important incentive for restoration is blue carbon storage. This is important as blue carbon ecosystems offer great potential as a climate change mitigation measure through their ability to sequester carbon. This was done by evaluating plant cover and sediment characteristics at sites along the length of the estuary representing disturbed and undisturbed areas. The estuarine health score for the Swartkops Estuary was found to be 47 out of 100 translating to a PES Category D (largely modified estuary). The main problem in the estuary is water quality along with habitat loss and resource exploitation. The three Wastewater Treatment Works (WWTWs) located upstream of the estuary are the main drivers behind the decline in estuary health in addition to other threats to the water quality which are stormwater run-off inputs from the Motherwell canal and Markman canal. This study showed that the health of the estuary is on a negative trajectory towards a largely degraded estuary. Fishing, bait collection and the use of spiritual sites are the dominant vii ecosystem services used at the estuary. Through the assessment of the state of the societal system, the estuary was highlighted to be a major food source for many people living close to the estuary through subsistence fishing and bait collection for selling to recreational fishers. The estuary is also a health hazard to the very same people that depend on it for survival because of the poor water quality particularly high metal inputs from past and present nearby industrial activities. Restoration plans need to be developed in consideration of the estuary status quo that includes the societal system and the ecosystem services provided by the estuary. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2022
- Full Text:
- Date Issued: 2022-04
Developing an effective HR framework/model to improve HR officials’ performance at the port of Port Elizabeth
- Authors: Maqetuka, Siphokazi Suzanne
- Date: 2022-04
- Subjects: Personnel management , Human Resources Assessment , Human resource professionals
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/57853 , vital:58280
- Description: With rising economic conditions and intense competitive conditions in business development, companies are increasingly facing the need to hire, motivate and retain talented people (Irana Bagaeva, 2018). Therefore, employees with the skills to meet market and customer requirements, regardless of ownership or the range of production in the modern world, are crucial to growth, survival, and sustainability. This emphasises the importance of those who must ensure that the above is achieved, that is, the human resources department of the organisation. The Human Resources Department is considered by business leaders and employees to be the body that builds and evaluates the human resources network that drives the effectiveness of the organization (Vanderpyl, 2018). Organisations need to be able to configure themselves, and HR leaders and teams keep their networks strong by not only satisfying regulations but also by leveraging and addressing social trends that benefit the organisation. Given the background highlighted above, which highlights the importance of an effective Human resource department and the role it ought to play in the organisation’s success, growth, and sustainability, it was therefore sought by the researcher to delve into the effectiveness of the Human resources department at the Port of Port Elizabeth, as they have continually been receiving mediocre performance ratings from the organisation’s leaders. Thus, the purpose of this study was to explore and investigate, from the Human Resource personnel in this department, their opinions of the effectiveness of the service offerings of the Human Resource department of the Port of PE to service the needs of their customers. This led to the development of a qualitative research approach where semi-structured interviews, supported with questionnaires, were conducted on all the personnel of the Human Resource department. The questionnaire contained closed and open-ended statements of opinions held by the respondents, which consisted of the Human resource personnel of the Port of Port Elizabeth. The study findings indicate that the Human Resource Department of the Port of PE is functioning at a mediocre level of service provision and that it is not a high-performing team or highly effective. The impact of mediocre service delivery means that the iii department is not fully meeting the client’s mandate that drives the People agenda of the organisation. There were a few factors identified in the study that prevented the team from reaching levels of high performance, and some can be attributed to organisational, systemic, and policy challenges preventing the team from reaching the required levels of service. A new Operating model has been presented in this study to address these challenges faced by the department. Finally, it was imperative to highlight the context in which the Port of Port Elizabeth exists, that being of Transnet which is a State-Owned enterprise that is therefore owned by the government, which has the mandate to drive the South African Government’s agenda of poverty and unemployment alleviation. , Thesis (MA) -- Faculty of Business and Economic science, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Maqetuka, Siphokazi Suzanne
- Date: 2022-04
- Subjects: Personnel management , Human Resources Assessment , Human resource professionals
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/57853 , vital:58280
- Description: With rising economic conditions and intense competitive conditions in business development, companies are increasingly facing the need to hire, motivate and retain talented people (Irana Bagaeva, 2018). Therefore, employees with the skills to meet market and customer requirements, regardless of ownership or the range of production in the modern world, are crucial to growth, survival, and sustainability. This emphasises the importance of those who must ensure that the above is achieved, that is, the human resources department of the organisation. The Human Resources Department is considered by business leaders and employees to be the body that builds and evaluates the human resources network that drives the effectiveness of the organization (Vanderpyl, 2018). Organisations need to be able to configure themselves, and HR leaders and teams keep their networks strong by not only satisfying regulations but also by leveraging and addressing social trends that benefit the organisation. Given the background highlighted above, which highlights the importance of an effective Human resource department and the role it ought to play in the organisation’s success, growth, and sustainability, it was therefore sought by the researcher to delve into the effectiveness of the Human resources department at the Port of Port Elizabeth, as they have continually been receiving mediocre performance ratings from the organisation’s leaders. Thus, the purpose of this study was to explore and investigate, from the Human Resource personnel in this department, their opinions of the effectiveness of the service offerings of the Human Resource department of the Port of PE to service the needs of their customers. This led to the development of a qualitative research approach where semi-structured interviews, supported with questionnaires, were conducted on all the personnel of the Human Resource department. The questionnaire contained closed and open-ended statements of opinions held by the respondents, which consisted of the Human resource personnel of the Port of Port Elizabeth. The study findings indicate that the Human Resource Department of the Port of PE is functioning at a mediocre level of service provision and that it is not a high-performing team or highly effective. The impact of mediocre service delivery means that the iii department is not fully meeting the client’s mandate that drives the People agenda of the organisation. There were a few factors identified in the study that prevented the team from reaching levels of high performance, and some can be attributed to organisational, systemic, and policy challenges preventing the team from reaching the required levels of service. A new Operating model has been presented in this study to address these challenges faced by the department. Finally, it was imperative to highlight the context in which the Port of Port Elizabeth exists, that being of Transnet which is a State-Owned enterprise that is therefore owned by the government, which has the mandate to drive the South African Government’s agenda of poverty and unemployment alleviation. , Thesis (MA) -- Faculty of Business and Economic science, 2022
- Full Text:
- Date Issued: 2022-04
Development and training projects for poverty alleviation in Zwide township Qgeberha
- Authors: Ngqezana, Amanda
- Date: 2022-04
- Subjects: Economic aspects -- South Africa , Economic development projects -- South Africa -- Port Elizabeth
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/58069 , vital:58535
- Description: The purpose of this study was to establish what projects have been implemented in Zwide Township in Gqeberha to alleviate poverty. Criteria for a successful poverty alleviation project were identified guided by the factors that determine poverty and the sustainability of the development and training projects in place to alleviate poverty. This study assessed existing projects to ascertain where they were successful and where they could improve. The study revealed that several projects and programmes have been planned in Gqeberha, specifically for Zwide Township, to alleviate poverty but according to Nelson Mandela Bay’s IDP (2017:04), several projects have been placed on hold due to a lack of funds. This was a qualitative study that employed documentary analysis to gather relevant data. The study concluded that the Nelson Mandela Bay Expanded Public Works Programme is currently in operation in Zwide Township and should continue to target unemployed youth and adults to alleviate poverty. , Thesis (MA) -- Faculty of Business and Economic science, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Ngqezana, Amanda
- Date: 2022-04
- Subjects: Economic aspects -- South Africa , Economic development projects -- South Africa -- Port Elizabeth
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/58069 , vital:58535
- Description: The purpose of this study was to establish what projects have been implemented in Zwide Township in Gqeberha to alleviate poverty. Criteria for a successful poverty alleviation project were identified guided by the factors that determine poverty and the sustainability of the development and training projects in place to alleviate poverty. This study assessed existing projects to ascertain where they were successful and where they could improve. The study revealed that several projects and programmes have been planned in Gqeberha, specifically for Zwide Township, to alleviate poverty but according to Nelson Mandela Bay’s IDP (2017:04), several projects have been placed on hold due to a lack of funds. This was a qualitative study that employed documentary analysis to gather relevant data. The study concluded that the Nelson Mandela Bay Expanded Public Works Programme is currently in operation in Zwide Township and should continue to target unemployed youth and adults to alleviate poverty. , Thesis (MA) -- Faculty of Business and Economic science, 2022
- Full Text:
- Date Issued: 2022-04
Development of a distributed optical fiber sensor for geological applications
- Authors: James, Jena
- Date: 2022-04
- Subjects: Polymers--Optical properties -- South Africa , Detectors—Materials
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/56156 , vital:55973
- Description: The purpose of the study was to develop a distributed optical fiber acoustic sensor for monitoring ground subsidence before collapse sinkholes form causing costly damage on infrastructure. Costs in excess of R1.3 billion have been incurred while dealing with sinkhole related measures in South Africa. Monitoring sinkholes and the presence of an early warning alert system can drastically reduce the impact, risk and cost caused by sudden ground collapse. A related goal was to construct a reliable collapse alert early warning system to facilitate disaster preparedness and avoid further damage from accidents. This was achieved by developing a spectroscopic shift monitoring algorithm which analysed changes in the subsurface vibration modes using ambient noise signals. For the first time to our knowledge, an optic fiber sensor with an early warning alarm, using ambient noise vibrations to detect and monitor sinkholes was developed at NMU. A polarisation-based, interferometric optical fiber seismic sensor was developed and compared to a commercial geophone. The fiber sensor exhibited superior performance in sensitivity, bandwidth, signal response and recovery times. The sensitivity of the optical fiber sensor was 0.47 rad/Pa surpassing the geophone sensitivity by 9.32%, and the bandwidth of 3.349kHz was 20 times greater for the optical fiber sensor. The fiber sensor was used to measure millisecond events as the impact duration of a bouncing ball was successfully obtained. It was used to detect sinkhole formation in the simulator model, designed. Ground collapse precursors were identified, and early warning alert was achieved using the spectral analysis algorithm, developed. The collapse precursor condition was identified as a functional combination of variations in the peak frequency, bandwidth and peak intensity. A distributed acoustic sensor was built to detect ambient noise induced subsurface signals. Vibrations were located along the 28km length of optical fiber with a relative error of 9.6%. The sensor demonstrated a frequency response range of 212.25Hz, an event distance precision of 224m with time resolution of 1.12µs, and a spatial resolution of 1km. The position of disturbance was measured within 300m of its actual point of 3.21km along the optical fiber. The results showed that distributed optical fiber sensing allows real-time monitoring of the subsurface over extended distances, using ambient noise signals. , Thesis (PhD) -- Faculty of Science, School of Computer Science, Mathematics, Physics and Statistics, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: James, Jena
- Date: 2022-04
- Subjects: Polymers--Optical properties -- South Africa , Detectors—Materials
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/56156 , vital:55973
- Description: The purpose of the study was to develop a distributed optical fiber acoustic sensor for monitoring ground subsidence before collapse sinkholes form causing costly damage on infrastructure. Costs in excess of R1.3 billion have been incurred while dealing with sinkhole related measures in South Africa. Monitoring sinkholes and the presence of an early warning alert system can drastically reduce the impact, risk and cost caused by sudden ground collapse. A related goal was to construct a reliable collapse alert early warning system to facilitate disaster preparedness and avoid further damage from accidents. This was achieved by developing a spectroscopic shift monitoring algorithm which analysed changes in the subsurface vibration modes using ambient noise signals. For the first time to our knowledge, an optic fiber sensor with an early warning alarm, using ambient noise vibrations to detect and monitor sinkholes was developed at NMU. A polarisation-based, interferometric optical fiber seismic sensor was developed and compared to a commercial geophone. The fiber sensor exhibited superior performance in sensitivity, bandwidth, signal response and recovery times. The sensitivity of the optical fiber sensor was 0.47 rad/Pa surpassing the geophone sensitivity by 9.32%, and the bandwidth of 3.349kHz was 20 times greater for the optical fiber sensor. The fiber sensor was used to measure millisecond events as the impact duration of a bouncing ball was successfully obtained. It was used to detect sinkhole formation in the simulator model, designed. Ground collapse precursors were identified, and early warning alert was achieved using the spectral analysis algorithm, developed. The collapse precursor condition was identified as a functional combination of variations in the peak frequency, bandwidth and peak intensity. A distributed acoustic sensor was built to detect ambient noise induced subsurface signals. Vibrations were located along the 28km length of optical fiber with a relative error of 9.6%. The sensor demonstrated a frequency response range of 212.25Hz, an event distance precision of 224m with time resolution of 1.12µs, and a spatial resolution of 1km. The position of disturbance was measured within 300m of its actual point of 3.21km along the optical fiber. The results showed that distributed optical fiber sensing allows real-time monitoring of the subsurface over extended distances, using ambient noise signals. , Thesis (PhD) -- Faculty of Science, School of Computer Science, Mathematics, Physics and Statistics, 2022
- Full Text:
- Date Issued: 2022-04
Early maladaptive schemas among re-offenders in Gqeberha 102
- Authors: Mantshiyose, Asisipho
- Date: 2022-04
- Subjects: Recidivism -- Gqeberha
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/58904 , vital:60246
- Description: high crime rate in South Africa showed an increase in 2018 with recidivism being the highest contributing factor. The increase in recidivism rates is a result of many factors, including the ineffectiveness of rehabilitation programmes. In an attempt to combat the increase in recidivism, its causes have been examined from a number of perspectives, especially social factors. However, very few studies have focussed on psychological factors when studying crime in South Africa. International studies have found personality factors to be a contributing factor towards recidivism. Concordantly, international studies have also established a correlation between early maladaptive schemas, a core component of personality, and crime. This study aimed to explore early maladaptive schemas among reoffenders in Gqeberha, South Africa. The objective of the study was to establish the prevalence of EMS in a sample of repeat offenders from the National Institute for Crime Prevention and the Reintegration of Offenders (NICRO) in Gqeberha. The study used a quantitative methodology and a sample size of 14 participants was utilised. Convenience sampling was utilised to identify reoffenders. The data was collected by administering a short demographical questionnaire and the Young Schema Questionnaire (YSQ). Descriptive statistics and Spearman’s correlations were utilised to analyse the data. , Thesis (MA) -- Faculty of Health Sciences, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Mantshiyose, Asisipho
- Date: 2022-04
- Subjects: Recidivism -- Gqeberha
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/58904 , vital:60246
- Description: high crime rate in South Africa showed an increase in 2018 with recidivism being the highest contributing factor. The increase in recidivism rates is a result of many factors, including the ineffectiveness of rehabilitation programmes. In an attempt to combat the increase in recidivism, its causes have been examined from a number of perspectives, especially social factors. However, very few studies have focussed on psychological factors when studying crime in South Africa. International studies have found personality factors to be a contributing factor towards recidivism. Concordantly, international studies have also established a correlation between early maladaptive schemas, a core component of personality, and crime. This study aimed to explore early maladaptive schemas among reoffenders in Gqeberha, South Africa. The objective of the study was to establish the prevalence of EMS in a sample of repeat offenders from the National Institute for Crime Prevention and the Reintegration of Offenders (NICRO) in Gqeberha. The study used a quantitative methodology and a sample size of 14 participants was utilised. Convenience sampling was utilised to identify reoffenders. The data was collected by administering a short demographical questionnaire and the Young Schema Questionnaire (YSQ). Descriptive statistics and Spearman’s correlations were utilised to analyse the data. , Thesis (MA) -- Faculty of Health Sciences, 2022
- Full Text:
- Date Issued: 2022-04
Effect of fire severity on Afrotemperate forest tree survival
- Authors: Giddey, Brandon Louis
- Date: 2022-04
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/55385 , vital:51988
- Description: Weather patterns have changed globally with increased fire danger weather conditions, along with poor management and fire suppression, likely contributing to the increase in prevalence of large wildfires. Ecosystems such as temperate broadleaved forests, where fire is limited by climatic conditions, are particularly at risk of altered fire regimes related to climate change. It is thus important to monitor the effects of fire in these ecosystems. Satellite remote sensing is a cost-effective way to assess spatial variability of fire effects on a landscape scale and has become an increasingly used tool for studying fire severity. In the southern Cape of South Africa during October-November 2018, a large wildfire burnt patches of Southern Cape Afrotemperate Forest (hereafter ‘Afrotemperate forest’). This provided an opportunity to investigate the accuracy of a satellite index for fire severity and the effect of fire on Afrotemperate forest survival. The first objective was to verify through field observations the accuracy of the differenced Normalised Burn Ratio (dNBR) as an index of fire severity derived from Sentinel 2 images in Afrotemperate forest. The second objective was to investigate the effect of fire severity and tree size on the post-fire survival of Afrotemperate forest tree species. For the first objective, stem fire severity, estimated from observed damage to the main stem, was recorded for 1 648 trees in 87 plots and linear regression used to test whether the observed measure of fire severity was related to dNBR. For the second objective, stem fire severity and tree survival 19-24 months post-fire were recorded for 40 species and 1 378 trees in 88 plots. Trees were considered to have survived if they resprouted from the main stem or had green foliage in the canopy. The survival response was assessed in relation to stem fire severity and tree size for all trees collectively and for 10 species (with sample size > 40) individually, using logistic regression. A strong linear relationship between dNBR and stem fire severity (r2 = 0.69, p < 0.001) confirmed the accuracy of dNBR as a measure of fire severity in Afrotemperate forest. In the fire investigated, 4 628 ha of Afrotemperate forest burnt of which 67% burnt at low severity, 21% at medium severity and 12% at high severity. The dNBR values associated with fire severity categories were comparable between Afrotemperate and North American forests, suggesting that dNBR values are relatively standard across forest types. Information on the distribution of fire severity facilitates investigation of further questions regarding past and future fire regimes and the fire ecology of Afrotemperate forest. The post-fire survival rate of Afrotemperate forest trees was 45% which is comparable to that in coniferous forests of North America but lower than that in temperate forests of Australia and Portugal and the neighbouring dune thicket which shares several species with Afrotemperate forest. Fire severity had a significant negative effect on survival and tree size a significant positive effect. Total variance explained by the model (for species collectively) was 40.8%, of which fire severity and tree size combined explained 13.2%, and species as random factor, 27.6%. Respective tree species showed differential survival responses – four species showed high survival (> 60% of individuals), while five species showed low survival (< 40%). This study was the first post-fire assessment of the resprouting ability of Afrotemperate forest trees and a third of the trees surveyed (for species collectively) resprouted from the stem. This suggested that resprouting from the stem is a primary means of post-fire recovery in Afrotemperate forest trees, in contrast with previous assertions that several common canopy species, including Podocarpus latifolius, Afrocarpus falcatus, Scutia myrtina, Scolopia mundii and Rapanea melanophloeos, are unable to resprout. Varying resilience to fire among species supports previous suggestions that fire affects species’ composition and diversity in these forests and calls for careful management of fire regimes in the face of global change. , Thesis (MSc) -- Faculty of Science, School of Natural Resource Management, 2022
- Full Text: false
- Date Issued: 2022-04
- Authors: Giddey, Brandon Louis
- Date: 2022-04
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/55385 , vital:51988
- Description: Weather patterns have changed globally with increased fire danger weather conditions, along with poor management and fire suppression, likely contributing to the increase in prevalence of large wildfires. Ecosystems such as temperate broadleaved forests, where fire is limited by climatic conditions, are particularly at risk of altered fire regimes related to climate change. It is thus important to monitor the effects of fire in these ecosystems. Satellite remote sensing is a cost-effective way to assess spatial variability of fire effects on a landscape scale and has become an increasingly used tool for studying fire severity. In the southern Cape of South Africa during October-November 2018, a large wildfire burnt patches of Southern Cape Afrotemperate Forest (hereafter ‘Afrotemperate forest’). This provided an opportunity to investigate the accuracy of a satellite index for fire severity and the effect of fire on Afrotemperate forest survival. The first objective was to verify through field observations the accuracy of the differenced Normalised Burn Ratio (dNBR) as an index of fire severity derived from Sentinel 2 images in Afrotemperate forest. The second objective was to investigate the effect of fire severity and tree size on the post-fire survival of Afrotemperate forest tree species. For the first objective, stem fire severity, estimated from observed damage to the main stem, was recorded for 1 648 trees in 87 plots and linear regression used to test whether the observed measure of fire severity was related to dNBR. For the second objective, stem fire severity and tree survival 19-24 months post-fire were recorded for 40 species and 1 378 trees in 88 plots. Trees were considered to have survived if they resprouted from the main stem or had green foliage in the canopy. The survival response was assessed in relation to stem fire severity and tree size for all trees collectively and for 10 species (with sample size > 40) individually, using logistic regression. A strong linear relationship between dNBR and stem fire severity (r2 = 0.69, p < 0.001) confirmed the accuracy of dNBR as a measure of fire severity in Afrotemperate forest. In the fire investigated, 4 628 ha of Afrotemperate forest burnt of which 67% burnt at low severity, 21% at medium severity and 12% at high severity. The dNBR values associated with fire severity categories were comparable between Afrotemperate and North American forests, suggesting that dNBR values are relatively standard across forest types. Information on the distribution of fire severity facilitates investigation of further questions regarding past and future fire regimes and the fire ecology of Afrotemperate forest. The post-fire survival rate of Afrotemperate forest trees was 45% which is comparable to that in coniferous forests of North America but lower than that in temperate forests of Australia and Portugal and the neighbouring dune thicket which shares several species with Afrotemperate forest. Fire severity had a significant negative effect on survival and tree size a significant positive effect. Total variance explained by the model (for species collectively) was 40.8%, of which fire severity and tree size combined explained 13.2%, and species as random factor, 27.6%. Respective tree species showed differential survival responses – four species showed high survival (> 60% of individuals), while five species showed low survival (< 40%). This study was the first post-fire assessment of the resprouting ability of Afrotemperate forest trees and a third of the trees surveyed (for species collectively) resprouted from the stem. This suggested that resprouting from the stem is a primary means of post-fire recovery in Afrotemperate forest trees, in contrast with previous assertions that several common canopy species, including Podocarpus latifolius, Afrocarpus falcatus, Scutia myrtina, Scolopia mundii and Rapanea melanophloeos, are unable to resprout. Varying resilience to fire among species supports previous suggestions that fire affects species’ composition and diversity in these forests and calls for careful management of fire regimes in the face of global change. , Thesis (MSc) -- Faculty of Science, School of Natural Resource Management, 2022
- Full Text: false
- Date Issued: 2022-04
Effect of fire severity on Afrotemperate forest tree survival
- Authors: Giddey, Brandon Louis
- Date: 2022-04
- Subjects: Trees -- Mortality , Wildfires
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/57413 , vital:57635
- Description: Weather patterns have changed globally with increased fire danger weather conditions, along with poor management and fire suppression, likely contributing to the increase in prevalence of large wildfires. Ecosystems such as temperate broad-leaved forests, where fire is limited by climatic conditions, are particularly at risk of altered fire regimes related to climate change. It is thus important to monitor the effects of fire in these ecosystems. Satellite remote sensing is a cost-effective way to assess spatial variability of fire effects on a landscape scale and has become an increasingly used tool for studying fire severity. In the southern Cape of South Africa during October-November 2018, a large wildfire burnt patches of Southern Cape Afrotemperate Forest (hereafter ‘Afrotemperate forest’). This provided an opportunity to investigate the accuracy of a satellite index for fire severity and the effect of fire on Afrotemperate forest survival. The first objective was to verify through field observations the accuracy of the differenced Normalised Burn Ratio (dNBR) as an index of fire severity derived from Sentinel 2 images in Afrotemperate forest. The second objective was to investigate the effect of fire severity and tree size on the post-fire survival of Afrotemperate forest tree species. For the first objective, stem fire severity, estimated from observed damage to the main stem, was recorded for 1 648 trees in 87 plots and linear regression used to test whether the observed measure of fire severity was related to dNBR. For the second objective, stem fire severity and tree survival 19-24 months post-fire were recorded for 40 species and 1 378 trees in 88 plots. Trees were considered to have survived if they resprouted from the main stem or had green foliage in the canopy. The survival response was assessed in relation to stem fire severity and tree size for all trees collectively and for 10 species (with sample size > 40) individually, using logistic regression. A strong linear relationship between dNBR and stem fire severity (r2 = 0.69, p < 0.001) confirmed the accuracy of dNBR as a measure of fire severity in Afrotemperate forest. In the fire investigated, 4 628 ha of Afrotemperate forest burnt of which 67% burnt at low severity, 21% at medium severity and 12% at high severity. The dNBR values associated with fire severity categories were comparable between Afrotemperate and North American forests, suggesting that dNBR values are relatively standard across forest types. Information on the distribution of fire severity vi facilitates investigation of further questions regarding past and future fire regimes and the fire ecology of Afrotemperate forest. The post-fire survival rate of Afrotemperate forest trees was 45% which is comparable to that in coniferous forests of North America but lower than that in temperate forests of Australia and Portugal and the neighbouring dune thicket which shares several species with Afrotemperate forest. Fire severity had a significant negative effect on survival and tree size a significant positive effect. Total variance explained by the model (for species collectively) was 40.8%, of which fire severity and tree size combined explained 13.2%, and species as random factor, 27.6%. Respective tree species showed differential survival responses – four species showed high survival (> 60% of individuals), while five species showed low survival (< 40%). This study was the first post-fire assessment of the resprouting ability of Afrotemperate forest trees and a third of the trees surveyed (for species collectively) resprouted from the stem. This suggested that resprouting from the stem is a primary means of post-fire recovery in Afrotemperate forest trees, in contrast with previous assertions that several common canopy species, including Podocarpus latifolius, Afrocarpus falcatus, Scutia myrtina, Scolopia mundii and Rapanea melanophloeos, are unable to resprout. Varying resilience to fire among species supports previous suggestions that fire affects species’ composition and diversity in these forests and calls for careful management of fire regimes in the face of global change. , Thesis (MSc) -- Faculty of Science, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Giddey, Brandon Louis
- Date: 2022-04
- Subjects: Trees -- Mortality , Wildfires
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/57413 , vital:57635
- Description: Weather patterns have changed globally with increased fire danger weather conditions, along with poor management and fire suppression, likely contributing to the increase in prevalence of large wildfires. Ecosystems such as temperate broad-leaved forests, where fire is limited by climatic conditions, are particularly at risk of altered fire regimes related to climate change. It is thus important to monitor the effects of fire in these ecosystems. Satellite remote sensing is a cost-effective way to assess spatial variability of fire effects on a landscape scale and has become an increasingly used tool for studying fire severity. In the southern Cape of South Africa during October-November 2018, a large wildfire burnt patches of Southern Cape Afrotemperate Forest (hereafter ‘Afrotemperate forest’). This provided an opportunity to investigate the accuracy of a satellite index for fire severity and the effect of fire on Afrotemperate forest survival. The first objective was to verify through field observations the accuracy of the differenced Normalised Burn Ratio (dNBR) as an index of fire severity derived from Sentinel 2 images in Afrotemperate forest. The second objective was to investigate the effect of fire severity and tree size on the post-fire survival of Afrotemperate forest tree species. For the first objective, stem fire severity, estimated from observed damage to the main stem, was recorded for 1 648 trees in 87 plots and linear regression used to test whether the observed measure of fire severity was related to dNBR. For the second objective, stem fire severity and tree survival 19-24 months post-fire were recorded for 40 species and 1 378 trees in 88 plots. Trees were considered to have survived if they resprouted from the main stem or had green foliage in the canopy. The survival response was assessed in relation to stem fire severity and tree size for all trees collectively and for 10 species (with sample size > 40) individually, using logistic regression. A strong linear relationship between dNBR and stem fire severity (r2 = 0.69, p < 0.001) confirmed the accuracy of dNBR as a measure of fire severity in Afrotemperate forest. In the fire investigated, 4 628 ha of Afrotemperate forest burnt of which 67% burnt at low severity, 21% at medium severity and 12% at high severity. The dNBR values associated with fire severity categories were comparable between Afrotemperate and North American forests, suggesting that dNBR values are relatively standard across forest types. Information on the distribution of fire severity vi facilitates investigation of further questions regarding past and future fire regimes and the fire ecology of Afrotemperate forest. The post-fire survival rate of Afrotemperate forest trees was 45% which is comparable to that in coniferous forests of North America but lower than that in temperate forests of Australia and Portugal and the neighbouring dune thicket which shares several species with Afrotemperate forest. Fire severity had a significant negative effect on survival and tree size a significant positive effect. Total variance explained by the model (for species collectively) was 40.8%, of which fire severity and tree size combined explained 13.2%, and species as random factor, 27.6%. Respective tree species showed differential survival responses – four species showed high survival (> 60% of individuals), while five species showed low survival (< 40%). This study was the first post-fire assessment of the resprouting ability of Afrotemperate forest trees and a third of the trees surveyed (for species collectively) resprouted from the stem. This suggested that resprouting from the stem is a primary means of post-fire recovery in Afrotemperate forest trees, in contrast with previous assertions that several common canopy species, including Podocarpus latifolius, Afrocarpus falcatus, Scutia myrtina, Scolopia mundii and Rapanea melanophloeos, are unable to resprout. Varying resilience to fire among species supports previous suggestions that fire affects species’ composition and diversity in these forests and calls for careful management of fire regimes in the face of global change. , Thesis (MSc) -- Faculty of Science, 2022
- Full Text:
- Date Issued: 2022-04