Facilities management competencies and performance : A case of a property company in the city of Johannesburg
- Authors: Matheba, Neo Elias
- Date: 2022-04
- Subjects: Property -- South Africa , Real estate management
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/58555 , vital:59812
- Description: Facilities management (FM) as a profession continues to evolve in the same manner and pace as the rest of the world. from being a profession hidden in the janitor rooms to being elevated to the senior executive position where influence on strategic organisational decisions is possible, FM professionals are required to possess virious skills, knowledge and qualifications to be considered competent and effective. the reserch seekd to establish the current qualifications and skills of the FM professionals in the Joburg property Company (JPC), thier attitudes and perceptions regarding FM qualification and training, the important competency requirements and practising levels, as well as the knowledge and application of strategic performance measures within the JPC to achieve its business objectives. , Thesis (MA) -- Faculty of Engineering, the Built Environment, and Technology, 2022
- Full Text: false
- Date Issued: 2022-04
- Authors: Matheba, Neo Elias
- Date: 2022-04
- Subjects: Property -- South Africa , Real estate management
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/58555 , vital:59812
- Description: Facilities management (FM) as a profession continues to evolve in the same manner and pace as the rest of the world. from being a profession hidden in the janitor rooms to being elevated to the senior executive position where influence on strategic organisational decisions is possible, FM professionals are required to possess virious skills, knowledge and qualifications to be considered competent and effective. the reserch seekd to establish the current qualifications and skills of the FM professionals in the Joburg property Company (JPC), thier attitudes and perceptions regarding FM qualification and training, the important competency requirements and practising levels, as well as the knowledge and application of strategic performance measures within the JPC to achieve its business objectives. , Thesis (MA) -- Faculty of Engineering, the Built Environment, and Technology, 2022
- Full Text: false
- Date Issued: 2022-04
Exploring the spiritual meaning of water among Amaxhosa: The study of spiritual practices in Isinuka
- Authors: Menye, Nomtha
- Date: 2022-04
- Subjects: Healing waters -- Eastern Cape , Xhosa (African people) --Religion -- South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/55811 , vital:53885
- Description: This study explores the spiritual relationship of water and uluntu lwase (people of) Port St. Johns, Eastern Cape, South Africa. Particularly the people that reside or regularly visit Isinuka sacred springs. This is done through an analysis and observations of the ritual practises performed at Isinuka sacred springs in Port St. Johns. This spring has provided sacred water used for healing, cleansing, and drinking for decades. Therefore, in this research we use the sacred water as an analysis point to understand the genesis of the ecological relationship of indigenous people and the environment. More so, this study uses the sacred water of the spring as an access point into indigenous knowledge systems (IKS) that have been passed on and maintained throughout history by the African elders. µRitual archives¶ have proved to carry indigenous knowledge systems on the history and philosophies of native regions and countries. Therefore, folktales, rituals, idioms and songs are didactic, and were intended to teach and sustain Isintu sakwa Xhosa (customs). This study uses observations ritual practises and face to face interviews to uncover the importance of nature and indigenous understanding of the environment from AmaXhosa residing in this area. The study was conducted in Port St. Johns in the rural parts of the Eastern Cape. Port St. Johns is a region of residing amaMpondo, which is an isiXhosa dialect. Therefore, amaMpondo and AmaXhosa are used in the study interchangeably. The researcher spent weeks visiting the spring daily and conducting qualitative semi-structured interviews. Observations and partaking in rituals were also used as a methodological approach to understand and capture the full experience of the sacred spring. The study uses the concept of as a medium to examine the relationship of water to spiritual ritual practises. The study literature shows a huge disjuncture between the literature written about the spring and the sociological meaning of the spring to the people that visit the spring. The results showed that the healing properties in the spring were caused by elements such as sulphur(s) and not the only the ritual practises that are performed at the spring. The study shows that, it is in the ritual practises that native Africans show their knowledge of the historical cosmological relationship between people and the environment. This is indicated in their use of sacred sites such as caves, rivers and ocean water to communicate with their ancestors. This study hopes to contribute towards a richer understanding of spirituality, ritual and archival work, for a holistic policymaking when dealing with water policies through an inclusive African indigenous perspective. , Thesis (MA) -- Faculty of Humanities, School of Sociology and anthropology, 2022
- Full Text:
- Date Issued: 2022-04
Exploring the spiritual meaning of water among Amaxhosa: The study of spiritual practices in Isinuka
- Authors: Menye, Nomtha
- Date: 2022-04
- Subjects: Healing waters -- Eastern Cape , Xhosa (African people) --Religion -- South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/55811 , vital:53885
- Description: This study explores the spiritual relationship of water and uluntu lwase (people of) Port St. Johns, Eastern Cape, South Africa. Particularly the people that reside or regularly visit Isinuka sacred springs. This is done through an analysis and observations of the ritual practises performed at Isinuka sacred springs in Port St. Johns. This spring has provided sacred water used for healing, cleansing, and drinking for decades. Therefore, in this research we use the sacred water as an analysis point to understand the genesis of the ecological relationship of indigenous people and the environment. More so, this study uses the sacred water of the spring as an access point into indigenous knowledge systems (IKS) that have been passed on and maintained throughout history by the African elders. µRitual archives¶ have proved to carry indigenous knowledge systems on the history and philosophies of native regions and countries. Therefore, folktales, rituals, idioms and songs are didactic, and were intended to teach and sustain Isintu sakwa Xhosa (customs). This study uses observations ritual practises and face to face interviews to uncover the importance of nature and indigenous understanding of the environment from AmaXhosa residing in this area. The study was conducted in Port St. Johns in the rural parts of the Eastern Cape. Port St. Johns is a region of residing amaMpondo, which is an isiXhosa dialect. Therefore, amaMpondo and AmaXhosa are used in the study interchangeably. The researcher spent weeks visiting the spring daily and conducting qualitative semi-structured interviews. Observations and partaking in rituals were also used as a methodological approach to understand and capture the full experience of the sacred spring. The study uses the concept of as a medium to examine the relationship of water to spiritual ritual practises. The study literature shows a huge disjuncture between the literature written about the spring and the sociological meaning of the spring to the people that visit the spring. The results showed that the healing properties in the spring were caused by elements such as sulphur(s) and not the only the ritual practises that are performed at the spring. The study shows that, it is in the ritual practises that native Africans show their knowledge of the historical cosmological relationship between people and the environment. This is indicated in their use of sacred sites such as caves, rivers and ocean water to communicate with their ancestors. This study hopes to contribute towards a richer understanding of spirituality, ritual and archival work, for a holistic policymaking when dealing with water policies through an inclusive African indigenous perspective. , Thesis (MA) -- Faculty of Humanities, School of Sociology and anthropology, 2022
- Full Text:
- Date Issued: 2022-04
Exploring the nature and scope of food insecurity among postgraduate students: a case of Nelson Mandela University
- Authors: Kuguyo, Yeukai T
- 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/10948/55348 , vital:51916
- Description: This study explores the nature and scope of food insecurity among postgraduate students at Nelson Mandela University, South Africa. The study employed a mixed method approach to access postgraduate students and university officials to investigate the prevalence of food insecurity. The approach also assesses the demographic factors; academic and mental implications along with the coping mechanisms associated with the experiences of food insecurity in higher education South Africa. The study incorporates an adapted conceptual framework from Alaimo’s food insecurity socio-economic risk models (2005) to understand the higher education context. Alaimo’s model seeks to connect the household conditions and broader systematic socio-economic mechanisms that households adopt to secure food. This model was adapted and employed in understanding the data collected while using a mixed-method approach between June and August 2021. The study employed an online survey for only postgraduate students enrolled at Nelson Mandela University (NMU) during the time of the study. This was supplemented by semi-structured interviews with student affairs officials that are directly involved in the formulation of strategies used to alleviate food insecurity at NMU. With 78 postgraduate students responding to the online survey, the study seems to confirm some of the studies done in this field on the inadequacy of food banks and food gardens in addressing food challenges effectively on campus. Similarly, the study found that the experiences of food insecurity were prevalent amongst postgraduate students that identified as black, low-income, and making access of the campus clinic for food relief. The study concluded by recommending a collaborative and a multi-level systematic approach in alleviating food insecurity in higher education. , Thesis (MA) -- Faculty of Humanities, School of Governmental and Social Sciences, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Kuguyo, Yeukai T
- 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/10948/55348 , vital:51916
- Description: This study explores the nature and scope of food insecurity among postgraduate students at Nelson Mandela University, South Africa. The study employed a mixed method approach to access postgraduate students and university officials to investigate the prevalence of food insecurity. The approach also assesses the demographic factors; academic and mental implications along with the coping mechanisms associated with the experiences of food insecurity in higher education South Africa. The study incorporates an adapted conceptual framework from Alaimo’s food insecurity socio-economic risk models (2005) to understand the higher education context. Alaimo’s model seeks to connect the household conditions and broader systematic socio-economic mechanisms that households adopt to secure food. This model was adapted and employed in understanding the data collected while using a mixed-method approach between June and August 2021. The study employed an online survey for only postgraduate students enrolled at Nelson Mandela University (NMU) during the time of the study. This was supplemented by semi-structured interviews with student affairs officials that are directly involved in the formulation of strategies used to alleviate food insecurity at NMU. With 78 postgraduate students responding to the online survey, the study seems to confirm some of the studies done in this field on the inadequacy of food banks and food gardens in addressing food challenges effectively on campus. Similarly, the study found that the experiences of food insecurity were prevalent amongst postgraduate students that identified as black, low-income, and making access of the campus clinic for food relief. The study concluded by recommending a collaborative and a multi-level systematic approach in alleviating food insecurity in higher education. , Thesis (MA) -- Faculty of Humanities, School of Governmental and Social Sciences, 2022
- Full Text:
- Date Issued: 2022-04
Exploring the Correlation of Two Field Tests with Match-Related Performance in Female Premier League Hockey Players
- Authors: Knott-Craig, Hannah Sue
- Date: 2022-04
- Subjects: Women hockey players
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/58892 , vital:60245
- Description: Background: Field hockey is a stick and ball team sport which is comprised of technical and tactical components and requires elevated physical conditioning. Due to the intermittent and complex nature of field hockey, it has become increasingly difficult for coaches to accurately measure the players hockey specific fitness levels. For this reason, various fitness tests have been developed over the years. However, some of the fitness tests utilised to this day do not incorporate movements similar to match situations, and therefore, do not stress the same energy systems in a similar manner to match-play. Hence, the INTER test and Dynamic Yo-Yo test are being utilised in the current study as they incorporate similar movements seen in match-play, and they incorporate varying rest periods. The INTER test is a test that incorporates shuttles, maximal sprints and agility movements. Whereas the Dynamic Yo-Yo test only incorporates shuttles running with differing changes in angles. However, both of these tests have previously only been used in a soccer context, therefore, the results obtained were compared to soccer specific data. Match-related data was compared to current field hockey data. Aim and Objectives: The main aim of the research study was to determine whether the INTER test and the Dynamic Yo-Yo test correlate with match-related physiological demands and physical performance. There were three main objectives of the study. First, to determine and describe the physical and physiological responses in selected cohort off hockey players during match-play, the INTER test and the Dynamic Yo-Yo test. Second, to run correlations between the two field tests and match-play to identify relationships. Third was to identify the differences between the two field tests. Methods: Using a combination of purposive and convenience sampling, a total of 20 field hockey players from the Eastern Cape Premier Hockey League voluntarily participated in the study (age: 22.25 ± 3.16 years; height: 167.3 ± 2.61cm; weight: 59.4 ± 3.87). The participants were monitored during the INTER test, Dynamic Yo-Yo test and the field hockey matches. The following physiological and physical variables were monitored: heart rate, breathing rate, distance and speed. The participants were given a minimum of 24 hours recovery time between field tests and matches to ensure fatigue did not impact results. The monitoring during the field tests and match-play was done by all participants wearing the Zephyr BioHarness and QStarz global positioning system. VI Results: The mean distance achieved in the INTER test and the Dynamic Yo-Yo test both produced a statistically strong relationship to the mean distance achieved in the matches (r=0.82, p=0.000). The time spent in the INTER test and the Dynamic Yo-Yo test compared to the time spent in match-play showed a very weak correlation (r=0.19; r=-0.08). Both the mean breathing rate for the INTER test and the Dynamic Yo-Yo test resulted in a very strong correlations (r=0.8) which was statistically significant (p=0.000). Participants spend on average 72% of match-play at >85% HRpeak compared to the 52% and 78% spent at >85% HRpeak during the INTER test and the Dynamic Yo-Yo test respectively. The INTER test produced a greater number of statistically significant correlations with the combined matches compared to the Dynamic Yo-Yo test. When identifying the differences between the variables measured in the INTER test and the Dynamic Yo-Yo test, it was identified that there were many significant differences. Conclusions: Both the Dynamic Yo-Yo and the INTER test can be used by hockey coaches. However, the researcher would recommend the utilisation of the INTER test, because it displayed stronger, more significant correlations to match-play. The set-up of the INTER test is also more convenient as it can be conducted on the astro turf. While, both tests did have some correlations to match-play, additional tests would need to be included in a testing battery to provide coaches with complete profiles of the players in order to assist in team selections. , Thesis (MA) -- Faculty of Health Sciences, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Knott-Craig, Hannah Sue
- Date: 2022-04
- Subjects: Women hockey players
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/58892 , vital:60245
- Description: Background: Field hockey is a stick and ball team sport which is comprised of technical and tactical components and requires elevated physical conditioning. Due to the intermittent and complex nature of field hockey, it has become increasingly difficult for coaches to accurately measure the players hockey specific fitness levels. For this reason, various fitness tests have been developed over the years. However, some of the fitness tests utilised to this day do not incorporate movements similar to match situations, and therefore, do not stress the same energy systems in a similar manner to match-play. Hence, the INTER test and Dynamic Yo-Yo test are being utilised in the current study as they incorporate similar movements seen in match-play, and they incorporate varying rest periods. The INTER test is a test that incorporates shuttles, maximal sprints and agility movements. Whereas the Dynamic Yo-Yo test only incorporates shuttles running with differing changes in angles. However, both of these tests have previously only been used in a soccer context, therefore, the results obtained were compared to soccer specific data. Match-related data was compared to current field hockey data. Aim and Objectives: The main aim of the research study was to determine whether the INTER test and the Dynamic Yo-Yo test correlate with match-related physiological demands and physical performance. There were three main objectives of the study. First, to determine and describe the physical and physiological responses in selected cohort off hockey players during match-play, the INTER test and the Dynamic Yo-Yo test. Second, to run correlations between the two field tests and match-play to identify relationships. Third was to identify the differences between the two field tests. Methods: Using a combination of purposive and convenience sampling, a total of 20 field hockey players from the Eastern Cape Premier Hockey League voluntarily participated in the study (age: 22.25 ± 3.16 years; height: 167.3 ± 2.61cm; weight: 59.4 ± 3.87). The participants were monitored during the INTER test, Dynamic Yo-Yo test and the field hockey matches. The following physiological and physical variables were monitored: heart rate, breathing rate, distance and speed. The participants were given a minimum of 24 hours recovery time between field tests and matches to ensure fatigue did not impact results. The monitoring during the field tests and match-play was done by all participants wearing the Zephyr BioHarness and QStarz global positioning system. VI Results: The mean distance achieved in the INTER test and the Dynamic Yo-Yo test both produced a statistically strong relationship to the mean distance achieved in the matches (r=0.82, p=0.000). The time spent in the INTER test and the Dynamic Yo-Yo test compared to the time spent in match-play showed a very weak correlation (r=0.19; r=-0.08). Both the mean breathing rate for the INTER test and the Dynamic Yo-Yo test resulted in a very strong correlations (r=0.8) which was statistically significant (p=0.000). Participants spend on average 72% of match-play at >85% HRpeak compared to the 52% and 78% spent at >85% HRpeak during the INTER test and the Dynamic Yo-Yo test respectively. The INTER test produced a greater number of statistically significant correlations with the combined matches compared to the Dynamic Yo-Yo test. When identifying the differences between the variables measured in the INTER test and the Dynamic Yo-Yo test, it was identified that there were many significant differences. Conclusions: Both the Dynamic Yo-Yo and the INTER test can be used by hockey coaches. However, the researcher would recommend the utilisation of the INTER test, because it displayed stronger, more significant correlations to match-play. The set-up of the INTER test is also more convenient as it can be conducted on the astro turf. While, both tests did have some correlations to match-play, additional tests would need to be included in a testing battery to provide coaches with complete profiles of the players in order to assist in team selections. , Thesis (MA) -- Faculty of Health Sciences, 2022
- Full Text:
- Date Issued: 2022-04
Exploring psychologists’ perceptions on how they integrate their own cultural belief systems within the therapeutic relationship in the Eastern Cape province, South Africa
- Authors: Potso, Thando
- Date: 2022-04
- Subjects: Psychologist -- Eastern Cape , Cultural competence , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/58936 , vital:60249
- Description: While there is extensive research exploring the influence of a client’s cultural beliefs on the therapeutic process; there is still a scarcity of information on how the cultural beliefs held by a psychologist may affect or influence the therapeutic process. Psychologists are trained to work with clients objectively by suspending their own beliefs, ideas, and values. Despite this, it would be interesting to explore how South African psychologists’ personal belief systems are navigated within the therapeutic space. Given the diversity of cultures within the South African context, it becomes important to explore and understand psychologists’ cultural belief systems, as they may influence the therapeutic relationship but to also, understand how they assimilate these belief systems into the therapeutic relationships with diverse clients. Drawing on the qualitative methodology, the study sought to draw participants using a purposive sampling technique. Participants were sourced through different databases, such as the Eastern Cape database of registered and practicing psychologists. Participants who agreed to partake in the study were sent an email with the interview schedule and the link to either MS Teams or Zoom, depending on their preference. The collected data was transcribed and then analysed using thematic analysis through which three themes and six sub-themes were identified and discussed. The identified themes are as follows; 1) Culture as perceived by psychologists, 2) Cultural beliefs in therapy and, 3) The therapeutic alliance. The study found that shared cultural beliefs between psychologists and clients facilitated rapport building. It allowed the therapeutic process to move in a positive direction. The study applied the principles of ethics and trustworthiness. , Thesis (MA) -- Faculty of Health Sciences, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Potso, Thando
- Date: 2022-04
- Subjects: Psychologist -- Eastern Cape , Cultural competence , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/58936 , vital:60249
- Description: While there is extensive research exploring the influence of a client’s cultural beliefs on the therapeutic process; there is still a scarcity of information on how the cultural beliefs held by a psychologist may affect or influence the therapeutic process. Psychologists are trained to work with clients objectively by suspending their own beliefs, ideas, and values. Despite this, it would be interesting to explore how South African psychologists’ personal belief systems are navigated within the therapeutic space. Given the diversity of cultures within the South African context, it becomes important to explore and understand psychologists’ cultural belief systems, as they may influence the therapeutic relationship but to also, understand how they assimilate these belief systems into the therapeutic relationships with diverse clients. Drawing on the qualitative methodology, the study sought to draw participants using a purposive sampling technique. Participants were sourced through different databases, such as the Eastern Cape database of registered and practicing psychologists. Participants who agreed to partake in the study were sent an email with the interview schedule and the link to either MS Teams or Zoom, depending on their preference. The collected data was transcribed and then analysed using thematic analysis through which three themes and six sub-themes were identified and discussed. The identified themes are as follows; 1) Culture as perceived by psychologists, 2) Cultural beliefs in therapy and, 3) The therapeutic alliance. The study found that shared cultural beliefs between psychologists and clients facilitated rapport building. It allowed the therapeutic process to move in a positive direction. The study applied the principles of ethics and trustworthiness. , Thesis (MA) -- Faculty of Health Sciences, 2022
- Full Text:
- Date Issued: 2022-04
Exchange rate volatility and bank performance: the case of South Africa
- Authors: Rozani, Zukiswa
- Date: 2022-04
- Subjects: Foreign exchange rates -- South Africa , Exchange rates -- South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/58156 , vital:58615
- Description: The increasing financial liberalisation since the collapse of the Bretton Woods regime in the 1970s has made exchange rates in both developing and industrialised countries unpredictable. As a result, both researchers and policymakers have become increasingly interested in the consequences and causes of exchange rate volatility. Fluctuations in foreign exchange rates may be a significant source of concern for banking institutions. In the worst case, significant losses in foreign exchange could result in financial crises, apart from causing significant constraints on the revenue growth of banks. This research study sought to investigate the volatility of exchange rates in South Africa and how this volatility affects commercial banks’ performance. The study was guided by both theoretical and empirical literature to achieve its main objective. This investigation is rooted in two theories: The Purchasing Power Parity theory, and the International Fishers Effect theory. The purchasing power parity (PPP) theory expresses that, homogeneous goods, in various countries, cost equally in similar countries when estimated in terms of the same currency (Brunnermeier and Pedersen, 2009). The theory postulates that if two homogeneous goods are traded at various costs in various countries, the arbitrage opportunity would be exploited, which prompts convergence of the deviations from Purchasing Power Parity towards equilibrium without arbitrage costs. The International Fisher Effect stipulates that the distinction in returns between two countries is simply equivalent to the distinction in inflation rates (Ross, Westerfield, Jaffe, & Jordan, 2008). The theory proposes that foreign currencies with relatively high-interest rates would depreciate on grounds that the high nominal interest rates reflect anticipated inflation. The nominal interest rates would likewise fuse the risk of an investment (Majok, 2015). The research adopts two econometric models namely: The EGARCH technique in modelling volatility, and the NARDL method to investigate the relationship. Results from the NARDL model reveal the occurrence of a long-run relationship between exchange rate volatility and bank performance. However, the influence of exchange rate on bank performance varies, depending on the type of proxy employed to measure bank performance. Four commercial banks revealed evidence of cointegration among the variables in the model in the short run, and indicated the v | P a g e speed of adjustment in the short run towards the long run. Nedbank’s return on equity, however, has an insignificant short-run relationship. Therefore, the study recommends that management of banks should place a greater emphasis on assessing and overseeing economic exposure, and factoring this into strategies in decision making. , Thesis (MA) -- Faculty of Business and Economic science, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Rozani, Zukiswa
- Date: 2022-04
- Subjects: Foreign exchange rates -- South Africa , Exchange rates -- South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/58156 , vital:58615
- Description: The increasing financial liberalisation since the collapse of the Bretton Woods regime in the 1970s has made exchange rates in both developing and industrialised countries unpredictable. As a result, both researchers and policymakers have become increasingly interested in the consequences and causes of exchange rate volatility. Fluctuations in foreign exchange rates may be a significant source of concern for banking institutions. In the worst case, significant losses in foreign exchange could result in financial crises, apart from causing significant constraints on the revenue growth of banks. This research study sought to investigate the volatility of exchange rates in South Africa and how this volatility affects commercial banks’ performance. The study was guided by both theoretical and empirical literature to achieve its main objective. This investigation is rooted in two theories: The Purchasing Power Parity theory, and the International Fishers Effect theory. The purchasing power parity (PPP) theory expresses that, homogeneous goods, in various countries, cost equally in similar countries when estimated in terms of the same currency (Brunnermeier and Pedersen, 2009). The theory postulates that if two homogeneous goods are traded at various costs in various countries, the arbitrage opportunity would be exploited, which prompts convergence of the deviations from Purchasing Power Parity towards equilibrium without arbitrage costs. The International Fisher Effect stipulates that the distinction in returns between two countries is simply equivalent to the distinction in inflation rates (Ross, Westerfield, Jaffe, & Jordan, 2008). The theory proposes that foreign currencies with relatively high-interest rates would depreciate on grounds that the high nominal interest rates reflect anticipated inflation. The nominal interest rates would likewise fuse the risk of an investment (Majok, 2015). The research adopts two econometric models namely: The EGARCH technique in modelling volatility, and the NARDL method to investigate the relationship. Results from the NARDL model reveal the occurrence of a long-run relationship between exchange rate volatility and bank performance. However, the influence of exchange rate on bank performance varies, depending on the type of proxy employed to measure bank performance. Four commercial banks revealed evidence of cointegration among the variables in the model in the short run, and indicated the v | P a g e speed of adjustment in the short run towards the long run. Nedbank’s return on equity, however, has an insignificant short-run relationship. Therefore, the study recommends that management of banks should place a greater emphasis on assessing and overseeing economic exposure, and factoring this into strategies in decision making. , Thesis (MA) -- Faculty of Business and Economic science, 2022
- Full Text:
- Date Issued: 2022-04
Evaluation of groundwater potential using geological and geophysical methods in the University of Fort Hare Alice Campus, Eastern Cape Province of South Africa
- Adesola, Gbenga Olamide https://orcid.org/0000-0002-4151-5305
- Authors: Adesola, Gbenga Olamide https://orcid.org/0000-0002-4151-5305
- Date: 2022-04
- Subjects: Groundwater , Geology, Structural -- South Africa , Geographical Information Systems
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22490 , vital:52344
- Description: Geological and geophysical methods were used to evaluate the groundwater potential in University of Fort Hare (Alice campus), Eastern Cape Province of South Africa. Methodologies adopted for obtaining these results included a comprehensive literature review, thin section analysis, scanning electron microscopy, Geographical Information Systems (GIS), remote sensing and geophysical investigations (magnetic survey and vertical electrical sounding). The geology of the study area belongs to the Balfour Formation, which forms part of the Beaufort Group in the Karoo Supergroup. The rocks within the study area are composed majorly of sandstone and mudstone. Lineaments were automatically extracted using the PCI Geomatica 2018 software. Fifteen samples were collected at various locations within the study area and were analyzed using the petrographic microscope while others were analyzed with the Scanning Electron Microscopic (SEM) combined with an Energy dispersive x-ray spectrometry. The results show that the rocks are fractured, porous and contained minerals such as quartz, feldspar, calcite, mica and clay minerals. The occurrence of these fractures helps to improve the groundwater storage capacity in the study area. Out of the twenty seven (27) rock samples collected in the field, ten (10) rock samples were selected for densities (dry, wet and grain densities) and porosity measurements in the laboratory. The rocks density values range from 2.5763 – 2.6978 g/cm3. The average porosities of the rocks range from 0.85 – 2.56 percent. The density of the sandstone ranges from 2.5908 – 2.6820 g/cm3 whilst the porosity range from 0.85 – 2.02 percent. The density of the mudstone ranges from 2.5763 – 2.6978 g/cm3 whilst the porosity ranges from 1.84 – 2.56 percent. About 8458 magnetic measurements were taken at about 20 m spacing along linear and non-linear paths and road. A variety of magnetic maps were generated. Several magnetic highs were observed and the linear highs were interpreted to be due to dolerite dykes whilst the broader high zones were inferred to be due to dolerite sills. These Karoo dolerites intruded the sediments at various depths and must have fractured the sediments causing them to be more porous and permeable. The depth slices of magnetic data reveal that near surface magnetic bodies occur within the depth of approximately 19 m from the surface while deep seated ones occur as deep as 31 m and maybe deeper. The knowledge of the dolerite intrusions enabled the location of drilling targets for groundwater. Electrical resistivity data were collected at 28 sites using the Schlumberger array and a maximum cable length (250 m) from the centre point which achieved a maximum depth penetration of about 70 m to 162 m. The results from 1D modelling using WINRESIST software showed that the vertical electric sounding curves are composed of HA and HK curve-types, which show four geoelectric layers. The resistivity of the first layer which is the topmost layer has values ranging from 20 - 5752 Ωm and the thickness is between 0.4 – 1.8 m. The second layer which consists of clay, mudstone and sandstone has resistivity values varying from 3 - 51 Ωm and thickness varying from 0.8 – 17.5 m. The third layer which is interpreted to be the aquiferous layer of the study area is made up majorly of sandstone with resistivity that varies from 136 – 352 Ωm and thickness range from 9.9 – 143.9 m. The fourth layer of resistivity varying from 44 to 60428 Ωm is made up of mudstone and sandstone, which are in some places intruded by dolerites. Groundwater potential is favourably high in some of the areas investigated. Furthermore, the results of the research indicated that secondary porosity is the main porosity for the reservoir rocks in the study area. , Thesis (MSc) -- Faculty of Science and Agriculture, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Adesola, Gbenga Olamide https://orcid.org/0000-0002-4151-5305
- Date: 2022-04
- Subjects: Groundwater , Geology, Structural -- South Africa , Geographical Information Systems
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22490 , vital:52344
- Description: Geological and geophysical methods were used to evaluate the groundwater potential in University of Fort Hare (Alice campus), Eastern Cape Province of South Africa. Methodologies adopted for obtaining these results included a comprehensive literature review, thin section analysis, scanning electron microscopy, Geographical Information Systems (GIS), remote sensing and geophysical investigations (magnetic survey and vertical electrical sounding). The geology of the study area belongs to the Balfour Formation, which forms part of the Beaufort Group in the Karoo Supergroup. The rocks within the study area are composed majorly of sandstone and mudstone. Lineaments were automatically extracted using the PCI Geomatica 2018 software. Fifteen samples were collected at various locations within the study area and were analyzed using the petrographic microscope while others were analyzed with the Scanning Electron Microscopic (SEM) combined with an Energy dispersive x-ray spectrometry. The results show that the rocks are fractured, porous and contained minerals such as quartz, feldspar, calcite, mica and clay minerals. The occurrence of these fractures helps to improve the groundwater storage capacity in the study area. Out of the twenty seven (27) rock samples collected in the field, ten (10) rock samples were selected for densities (dry, wet and grain densities) and porosity measurements in the laboratory. The rocks density values range from 2.5763 – 2.6978 g/cm3. The average porosities of the rocks range from 0.85 – 2.56 percent. The density of the sandstone ranges from 2.5908 – 2.6820 g/cm3 whilst the porosity range from 0.85 – 2.02 percent. The density of the mudstone ranges from 2.5763 – 2.6978 g/cm3 whilst the porosity ranges from 1.84 – 2.56 percent. About 8458 magnetic measurements were taken at about 20 m spacing along linear and non-linear paths and road. A variety of magnetic maps were generated. Several magnetic highs were observed and the linear highs were interpreted to be due to dolerite dykes whilst the broader high zones were inferred to be due to dolerite sills. These Karoo dolerites intruded the sediments at various depths and must have fractured the sediments causing them to be more porous and permeable. The depth slices of magnetic data reveal that near surface magnetic bodies occur within the depth of approximately 19 m from the surface while deep seated ones occur as deep as 31 m and maybe deeper. The knowledge of the dolerite intrusions enabled the location of drilling targets for groundwater. Electrical resistivity data were collected at 28 sites using the Schlumberger array and a maximum cable length (250 m) from the centre point which achieved a maximum depth penetration of about 70 m to 162 m. The results from 1D modelling using WINRESIST software showed that the vertical electric sounding curves are composed of HA and HK curve-types, which show four geoelectric layers. The resistivity of the first layer which is the topmost layer has values ranging from 20 - 5752 Ωm and the thickness is between 0.4 – 1.8 m. The second layer which consists of clay, mudstone and sandstone has resistivity values varying from 3 - 51 Ωm and thickness varying from 0.8 – 17.5 m. The third layer which is interpreted to be the aquiferous layer of the study area is made up majorly of sandstone with resistivity that varies from 136 – 352 Ωm and thickness range from 9.9 – 143.9 m. The fourth layer of resistivity varying from 44 to 60428 Ωm is made up of mudstone and sandstone, which are in some places intruded by dolerites. Groundwater potential is favourably high in some of the areas investigated. Furthermore, the results of the research indicated that secondary porosity is the main porosity for the reservoir rocks in the study area. , Thesis (MSc) -- Faculty of Science and Agriculture, 2022
- Full Text:
- Date Issued: 2022-04
Evaluation of antimicrobial combination therapy options for the management of integron-mediated multidrug resistance in enterococcus species and acinetobacter baumannii from aquatic environment in the Eastern Cape Province, South Africa
- Authors: Ola, Adeniji Oluwaseun
- Date: 2022-04
- Subjects: Enterococcus , Aquatic biodiversity , Acinetobacter
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/27776 , vital:69467
- Description: Infectious diseases caused by multidrug-resistant MDR pathogens, such as Acinetobacter baumannii and Enterococcus spp., is an increasing worldwide problem. For treating these diseases, antibiotics are usually the first choice. But organisms develop resistance as a result of drug abuse, continuous use of antibiotics and release of antibiotics into the environment. These have prompted MDR's development, making even the most active drugs ineffective. Transposons, plasmids and integrons are the most effective mobile genetic elements that promote acquisition and spread of resistance determinants. Integrons carrying various arrays of resistance gene cassettes are principally helpful for epidemiological studies of these disease-causing organisms. Alternative treatments, such as using drugs in combination or with adjuvants and nanoparticles therapy, have been documented. Nanoparticles have the potential requirements for qualifying as antibacterial agents. In addition to their antimicrobial activities, nanoparticles can be used together with antibiotics for more enhanced antimicrobial activity In this study, Acinetobacter baumanni, Enterococcus faecium and Enterococcus faecalis were recovered from the aquatic environment in the Eastern Cape Province, South Africa with a standard microbiological method. Their antibiotic sensitivity testing was carried out using Kirby Bauer disk diffusion and microdilution methods. A high occurrence of class-1 integrons was discovered in MDR A. baumanni, with the internal variable containing aadA1, aadA5 and aadA2 genes, which confer resistance for streptomycin and spectinomycin, aac 6Ib for amikacin/ tobramycin and dfrA17 genes for trimethoprim. Similarly, class1 integron was detected in Enterococcus, without the presence of gene cassette. The checkerboard assay and time-kill assay were used to test for the effect of the combination of the antibiotic. The impact of colistin combined with quinolones (ciprofloxacin) with the Fractional inhibitory concentration index FICs 0.31 indicated synergistic effects against MDR A baumanni. However, when colistin was combined with meropenem and ceftazidime, additive effects with FIC, ranging from 0.52 to 1 were observed. In addition, a combination of gentamicin MIC 4 μgml with vancomycin MIC 256 μgml antibiotics against vancomycin-resistant Enterococcus faecalis showed antibacterial activity. In contrast, the combination of ciprofloxacin 1 μgml with Ampicillin 16 μgml antibiotics against Enterococcus faecalis showed a bacteriostatic effect. The initial inoculum declined by 100 percentage when gentamicin was combined with vancomycin at a concentration of 4 and 128 μgml MIC respectively, for about 2 h following the treatment for MDR E. faecium. Enterobacterial Repetitive Intergenic Consensus Polymerase Chain Reaction ERIC PCR analyses of the studied pathogens revealed great genetic diversity, suggesting the various sources of environmental contamination. Silver nanoparticles AgNPs and zinc oxide nanoparticles ZnO NPs were chemically synthesized using a precipitation method and characterized using energy dispersive Xray analysis EDX, scanning electron microscopy SEM, Fourier transforms infrared spectroscopic analysis FTIR and transmission electron microscopy TEM. The characterization results showed the synthesis of 43.37 nm and 21.03 nm nanoparticles of zinc oxide and silver origins, correspondingly, with distinct morphology, as revealed in TEM. The size, stability and functional groups of the nanoparticles produced were revealed using EDX and FTIR. Zinc oxide nanoparticles were cytotoxic against Vero cell lines at the tested concentrations, whereas AgNPs had no cytotoxic effect at lower concentrations. Acinetobacter baumanni, Enterococcus faecium and Enterococcus faecalis were with MIC in the range of 0.0390.078mgml for silver nanoparticles. Zinc oxide nanoparticles were explicitly active against Enterococcus species gram-positive with MIC of 1.25 5 mgml. Both studied nanoparticles exhibited profound synergistic and additive activities against all the investigated MDR pathogens. These findings demonstrate good antibacterial potential of the nanoparticles against drug-resistant strains and open a new arena of antimicrobials for medical treatment. , Thesis (MSc) -- Faculty of Science and Agriculture, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Ola, Adeniji Oluwaseun
- Date: 2022-04
- Subjects: Enterococcus , Aquatic biodiversity , Acinetobacter
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/27776 , vital:69467
- Description: Infectious diseases caused by multidrug-resistant MDR pathogens, such as Acinetobacter baumannii and Enterococcus spp., is an increasing worldwide problem. For treating these diseases, antibiotics are usually the first choice. But organisms develop resistance as a result of drug abuse, continuous use of antibiotics and release of antibiotics into the environment. These have prompted MDR's development, making even the most active drugs ineffective. Transposons, plasmids and integrons are the most effective mobile genetic elements that promote acquisition and spread of resistance determinants. Integrons carrying various arrays of resistance gene cassettes are principally helpful for epidemiological studies of these disease-causing organisms. Alternative treatments, such as using drugs in combination or with adjuvants and nanoparticles therapy, have been documented. Nanoparticles have the potential requirements for qualifying as antibacterial agents. In addition to their antimicrobial activities, nanoparticles can be used together with antibiotics for more enhanced antimicrobial activity In this study, Acinetobacter baumanni, Enterococcus faecium and Enterococcus faecalis were recovered from the aquatic environment in the Eastern Cape Province, South Africa with a standard microbiological method. Their antibiotic sensitivity testing was carried out using Kirby Bauer disk diffusion and microdilution methods. A high occurrence of class-1 integrons was discovered in MDR A. baumanni, with the internal variable containing aadA1, aadA5 and aadA2 genes, which confer resistance for streptomycin and spectinomycin, aac 6Ib for amikacin/ tobramycin and dfrA17 genes for trimethoprim. Similarly, class1 integron was detected in Enterococcus, without the presence of gene cassette. The checkerboard assay and time-kill assay were used to test for the effect of the combination of the antibiotic. The impact of colistin combined with quinolones (ciprofloxacin) with the Fractional inhibitory concentration index FICs 0.31 indicated synergistic effects against MDR A baumanni. However, when colistin was combined with meropenem and ceftazidime, additive effects with FIC, ranging from 0.52 to 1 were observed. In addition, a combination of gentamicin MIC 4 μgml with vancomycin MIC 256 μgml antibiotics against vancomycin-resistant Enterococcus faecalis showed antibacterial activity. In contrast, the combination of ciprofloxacin 1 μgml with Ampicillin 16 μgml antibiotics against Enterococcus faecalis showed a bacteriostatic effect. The initial inoculum declined by 100 percentage when gentamicin was combined with vancomycin at a concentration of 4 and 128 μgml MIC respectively, for about 2 h following the treatment for MDR E. faecium. Enterobacterial Repetitive Intergenic Consensus Polymerase Chain Reaction ERIC PCR analyses of the studied pathogens revealed great genetic diversity, suggesting the various sources of environmental contamination. Silver nanoparticles AgNPs and zinc oxide nanoparticles ZnO NPs were chemically synthesized using a precipitation method and characterized using energy dispersive Xray analysis EDX, scanning electron microscopy SEM, Fourier transforms infrared spectroscopic analysis FTIR and transmission electron microscopy TEM. The characterization results showed the synthesis of 43.37 nm and 21.03 nm nanoparticles of zinc oxide and silver origins, correspondingly, with distinct morphology, as revealed in TEM. The size, stability and functional groups of the nanoparticles produced were revealed using EDX and FTIR. Zinc oxide nanoparticles were cytotoxic against Vero cell lines at the tested concentrations, whereas AgNPs had no cytotoxic effect at lower concentrations. Acinetobacter baumanni, Enterococcus faecium and Enterococcus faecalis were with MIC in the range of 0.0390.078mgml for silver nanoparticles. Zinc oxide nanoparticles were explicitly active against Enterococcus species gram-positive with MIC of 1.25 5 mgml. Both studied nanoparticles exhibited profound synergistic and additive activities against all the investigated MDR pathogens. These findings demonstrate good antibacterial potential of the nanoparticles against drug-resistant strains and open a new arena of antimicrobials for medical treatment. , Thesis (MSc) -- Faculty of Science and Agriculture, 2022
- Full Text:
- Date Issued: 2022-04
Enterprise development funds as a catalyst for growth and sustainability of black-owned SMMEs in manufacturing
- Authors: Tsheketshe, Yomelela Mfundo
- Date: 2022-04
- Subjects: Business enterprises, Black -- South Africa , Small business
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/58223 , vital:58742
- Description: South Africa is confronted with a skewed economy along racial lines through a history of colonialism and apartheid. The laws of government have tried to include companies in advancing social cohesion and in dealing with issues of the historical exclusion of African communities from the mainstream economy. With the advent of democracy, the government has been faced with the mammoth task of driving transformation and inclusion in various sectors of the economy. Various pieces of legislation have been promulgated to give effect to this ideal. The Broad Based Black Economic Empowerment (BBBEE) Act with its associated regulations has Enterprise and Supplier development (ESD) as one of the five pillars underpinning the targeted areas for transformation in companies. Enterprise development is a key contributor to companies achieving a good score card rating as determined by the government of South Africa for various industries. This scoring also has advantages in terms of accessing government incentives as well as procurement opportunities for businesses with government. Companies therefore deploy capital for the development of businesses within their supply chains and also any other businesses whether or not they do business with them. This process of enterprise development funding is largely undefined and sees companies use various methods and criteria to deploy the capital with a myriad of outcomes all of which vary depending on the area of interest. The primary intent of the enterprise development funds is to create patient, free and sometimes affordable capital for the growth and sustainability of previously disadvantaged businesses in the South African context. Industries like manufacturing, in their nature are capital intensive and require huge capital outlays which then become a barrier to entry particularly for previously disadvantaged groupings like black people. The aim of the study is to identify key determinants that can unlock the growth and sustainability of black owned SMMEs in the manufacturing sector and also to understand the environment in which they operate. It is intended to assist policy makers, enterprise development practitioners, regulators and the beneficiaries of enterprise development on what can be done to ensure that this critical programme achieves its desired outcome. , Thesis (MA) -- Faculty of Business and Economic science, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Tsheketshe, Yomelela Mfundo
- Date: 2022-04
- Subjects: Business enterprises, Black -- South Africa , Small business
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/58223 , vital:58742
- Description: South Africa is confronted with a skewed economy along racial lines through a history of colonialism and apartheid. The laws of government have tried to include companies in advancing social cohesion and in dealing with issues of the historical exclusion of African communities from the mainstream economy. With the advent of democracy, the government has been faced with the mammoth task of driving transformation and inclusion in various sectors of the economy. Various pieces of legislation have been promulgated to give effect to this ideal. The Broad Based Black Economic Empowerment (BBBEE) Act with its associated regulations has Enterprise and Supplier development (ESD) as one of the five pillars underpinning the targeted areas for transformation in companies. Enterprise development is a key contributor to companies achieving a good score card rating as determined by the government of South Africa for various industries. This scoring also has advantages in terms of accessing government incentives as well as procurement opportunities for businesses with government. Companies therefore deploy capital for the development of businesses within their supply chains and also any other businesses whether or not they do business with them. This process of enterprise development funding is largely undefined and sees companies use various methods and criteria to deploy the capital with a myriad of outcomes all of which vary depending on the area of interest. The primary intent of the enterprise development funds is to create patient, free and sometimes affordable capital for the growth and sustainability of previously disadvantaged businesses in the South African context. Industries like manufacturing, in their nature are capital intensive and require huge capital outlays which then become a barrier to entry particularly for previously disadvantaged groupings like black people. The aim of the study is to identify key determinants that can unlock the growth and sustainability of black owned SMMEs in the manufacturing sector and also to understand the environment in which they operate. It is intended to assist policy makers, enterprise development practitioners, regulators and the beneficiaries of enterprise development on what can be done to ensure that this critical programme achieves its desired outcome. , Thesis (MA) -- Faculty of Business and Economic science, 2022
- Full Text:
- Date Issued: 2022-04
Encapsulation of flame retardants for lithium-ion battery safety
- Authors: Ntombela, Nompilo Princess
- 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/10948/55412 , vital:51993
- Description: Lithium-ion technology takes the lead in electric mobility systems, resulting in an increase in the global demand for Li-ion batteries; however, these batteries are associated with numerous safety concerns. Additionally, there are high costs, high energy and power issues which are some of its key limitations. Research efforts are focused on overcoming these obstacles, with different approaches being explored, such as the investigation of more stable salts, modification of active materials and organic solvents, and the use of electrolyte additives. This study focused specifically on electrolyte additives since the electrolyte is one of the most unstable components of the battery. The electrolyte’s decomposition is one of the reactions that occur inside a battery, which may occur due to overcharging or due to an internal short circuit, amongst others. The electrolyte’s decomposition occurs at the early stages of the thermal runaway process and forms part of the reactions that lead to fires and explosions. Thus, this research aims to develop suitable electrolyte additives to improve the safety aspects of Li-ion batteries. Flame retardant additives show great promise in reducing the flammability of the electrolyte in Li-ion batteries, since they serve to suppress the chemical reactions associated with battery ignition. They retard the fires by scavenging the active radical species formed during the decomposition reaction. In this study, the use of flame retardants was investigated. Flame retardant additives have shown to have flame impeding properties inside a battery; however, their direct addition to the electrolyte tends to cause adverse effects on the ionic conductivity and electrochemical performance of the cells. This study investigated an alternative option - the option to microencapsulate such additives into a neutral compound to ensure that the flame retardant has minimal/no effect on the performance of the battery. This investigation looked at tris(2-butoxyethyl) phosphate (TBP) and bis(2,2,2-trifluoroethyl) methylphosphonate (BFP) as flame retardant additives for the electrolyte. The TBP and BFP flame retardants were microencapsulated in poly(urea formaldehyde) (PUF) coating material via in situ polymerization method. The capsules were characterized using various analytical techniques - to prove it was successfully encapsulated. Electrochemical studies were further done on the capsules and neat flame retardants inside a coin cell. Self-extinguishing time (SET), which is the flammability test, proved that the additives have flame retarding abilities. Opto-digital microscopy (DSX) and scanning electron microscopy (SEM) did confirm the spherical shape of the microcapsules, where SEM also showed the smooth outer layer of the microcapsules and its hollow inner side. Fourier transform infrared spectroscopy (FTIR) proved the presence of the TBP and BFP inside the PUF resin by showing that the chemical composition of microcapsules consisted of both the PUF and flame retardant additives. Simultaneous DSC-TGA (DST) was also performed which showed that the microcapsules were stable before 200 °C, which indicates it would not decompose before the thermal runaway events are occurring. TGA analysis did show that the microcapsules underwent multiple decomposition steps upon heating. Additionally, 31P nuclear magnetic resonance (NMR) was used to quantify the amount of flame retardants additives encapsulated inside PUF shell, and also confirmed the stability of the microcapsules for one month in the electrolyte and at temperatures up to 200 °C. The ionic conductivity was vastly decreased when the flame retardants were added directly to the electrolyte. However, adding the flame retardants in a form of capsules had minimal effect on the ionic conductivity. The cycle capacities of the capsules were also improved when the capsules were added to the cell compared to that of neat flame retardants. The same effect was also noticed when doing Electrochemical Impedance Spectroscopy (EIS). This shows that microencapsulation improves the resistance of the cell caused by the flame retardant in comparison to when added directly to the electrolyte of the cell. , Thesis (MSC) -- Faculty of Science, School of Biomolecular and Chemical Sciences, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Ntombela, Nompilo Princess
- 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/10948/55412 , vital:51993
- Description: Lithium-ion technology takes the lead in electric mobility systems, resulting in an increase in the global demand for Li-ion batteries; however, these batteries are associated with numerous safety concerns. Additionally, there are high costs, high energy and power issues which are some of its key limitations. Research efforts are focused on overcoming these obstacles, with different approaches being explored, such as the investigation of more stable salts, modification of active materials and organic solvents, and the use of electrolyte additives. This study focused specifically on electrolyte additives since the electrolyte is one of the most unstable components of the battery. The electrolyte’s decomposition is one of the reactions that occur inside a battery, which may occur due to overcharging or due to an internal short circuit, amongst others. The electrolyte’s decomposition occurs at the early stages of the thermal runaway process and forms part of the reactions that lead to fires and explosions. Thus, this research aims to develop suitable electrolyte additives to improve the safety aspects of Li-ion batteries. Flame retardant additives show great promise in reducing the flammability of the electrolyte in Li-ion batteries, since they serve to suppress the chemical reactions associated with battery ignition. They retard the fires by scavenging the active radical species formed during the decomposition reaction. In this study, the use of flame retardants was investigated. Flame retardant additives have shown to have flame impeding properties inside a battery; however, their direct addition to the electrolyte tends to cause adverse effects on the ionic conductivity and electrochemical performance of the cells. This study investigated an alternative option - the option to microencapsulate such additives into a neutral compound to ensure that the flame retardant has minimal/no effect on the performance of the battery. This investigation looked at tris(2-butoxyethyl) phosphate (TBP) and bis(2,2,2-trifluoroethyl) methylphosphonate (BFP) as flame retardant additives for the electrolyte. The TBP and BFP flame retardants were microencapsulated in poly(urea formaldehyde) (PUF) coating material via in situ polymerization method. The capsules were characterized using various analytical techniques - to prove it was successfully encapsulated. Electrochemical studies were further done on the capsules and neat flame retardants inside a coin cell. Self-extinguishing time (SET), which is the flammability test, proved that the additives have flame retarding abilities. Opto-digital microscopy (DSX) and scanning electron microscopy (SEM) did confirm the spherical shape of the microcapsules, where SEM also showed the smooth outer layer of the microcapsules and its hollow inner side. Fourier transform infrared spectroscopy (FTIR) proved the presence of the TBP and BFP inside the PUF resin by showing that the chemical composition of microcapsules consisted of both the PUF and flame retardant additives. Simultaneous DSC-TGA (DST) was also performed which showed that the microcapsules were stable before 200 °C, which indicates it would not decompose before the thermal runaway events are occurring. TGA analysis did show that the microcapsules underwent multiple decomposition steps upon heating. Additionally, 31P nuclear magnetic resonance (NMR) was used to quantify the amount of flame retardants additives encapsulated inside PUF shell, and also confirmed the stability of the microcapsules for one month in the electrolyte and at temperatures up to 200 °C. The ionic conductivity was vastly decreased when the flame retardants were added directly to the electrolyte. However, adding the flame retardants in a form of capsules had minimal effect on the ionic conductivity. The cycle capacities of the capsules were also improved when the capsules were added to the cell compared to that of neat flame retardants. The same effect was also noticed when doing Electrochemical Impedance Spectroscopy (EIS). This shows that microencapsulation improves the resistance of the cell caused by the flame retardant in comparison to when added directly to the electrolyte of the cell. , Thesis (MSC) -- Faculty of Science, School of Biomolecular and Chemical Sciences, 2022
- Full Text:
- Date Issued: 2022-04
Effect of pomegranate (Punica granatum L) peel powder meal on growth performance, gut integrity, haemato-biochemical indices, meat, and bone quality of broiler chickens
- Akuru, Eunice Amaka https://orcid.org/0000-0002-3093-0247
- Authors: Akuru, Eunice Amaka https://orcid.org/0000-0002-3093-0247
- Date: 2022-04
- Subjects: Broilers (Chickens) , Meat -- Quality
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/23611 , vital:58218
- Description: The objective of the current study was to investigate the overall response of broiler birds to varying dietary levels of pomegranate (Punica granatum L) peel powder meal (PPPM). A total of 432-day-old Cobb 500 broiler chicks were randomly divided into six experimental groups of four replications with 18 birds per replicate in a completely randomized design (CRD). The birds were fed isonitrogenous and isocaloric experimental diets designated as: T1-control diet with 0percent additives (negative control; NEGCON); T2- control diet supplemented with α-tocopherol acetate at 200g per ton (positive control; POSCON): T3, T4, T5 and T6-control diet supplemented with 2, 4, 6 and 8g/kg PPPM (PPPM2, PPPM4, PPPM6, PPPM8). The phytochemical, nutritional and antioxidant properties of the pomegranate peel powder were determined. Results showed that the South African-grown pomegranate peel (“Wonderful” variety) had rich protein and trace mineral contents. Higher (p < 0.05) antioxidant and hepatic anti-lipid peroxidative activities were recorded in the ethanol and acetone extracts than the water extract, whereas the three extracts had no toxic effects on liver and kidney cells (p > 0.05). The dietary effects of PPPM supplementation on growth performance, digestibility, carcass, and organ weight indices of Cobb 500 birds were determined. The POSCON diet enhanced (p < 0.05) feed conversion ratio (FCR) at week 3. The average final body weight and average daily weight gain were highest (p < 0.05) in birds fed PPPM2 and PPPM4 diets, whereas birds fed PPPM2 diet had enhanced (p < 0.05) FCR and protein efficiency ratio when compared with birds on POSCON. Thigh and breast weights were highest (p < 0.05) in birds on PPPM4 and PPPM8 diets, whereas birds fed PPPM4 diet had enhanced (p < 0.05) nutrient digestibility compared with those on POSCON. The antioxidant status and breast meat quality of Cobb 500 broiler birds fed diets supplemented with PPPM were determined. Meat from birds fed PPPM8 diet had the highest (p < 0.05) thawing loss, while cooking loss was lowest (p < 0.05) in the PPPM2 group. The highest (p < 0.05) ability to scavenge ABTS [(2, 2-azinobis (3ethylbenzothiazoline-6 sulfonic acid))] radical cation (ABTS+) was recorded in the PPPM2 and PPPM4 meat while PPPM8 meat had increased (p < 0.05) catalase activity. The fatty acid composition, oxidative status, and drip loss in breast meat of Cobb 500 broiler birds fed graded levels of PPPM was determined. Meat from birds fed PPPM4 diet had the lowest (p < 0.05) margaric (C17:0) and arachidic (C20:0) acids, while meat from birds fed PPPM8 diet had higher (p < 0.05) levels of eicosadenoic (C20:2, n-6) and arachidonic (AA, 20:4) acids. The POSCON had higher (p < 0.05) ability to reduce TBARS levels in meat on day-1 and day-16 of storage than the NEGCON and PPPM diets, whereas TBARS levels were lowest (p < 0.05) in PPPM6 meat on day-16. The gut pH, histology, haematology, serum-biochemical indices, and bone quality parameters of Cobb 500 broiler birds fed diets supplemented with PPPM was determined. Birds fed POSCON, PPM2 and PPPM4 diets had the lowest (p < 0.05) pH in the duodenum, jejunum, and caecum, whereas duodenal pH values were lowest (p < 0.05) in birds fed PPPM2 and PPPM4 diets compared with birds on NEGCON. Birds fed PPPM4 diet had the highest (p < 0.01) duodenal, jejunal and ileal villi height (VH), and the highest (p < 0.01) VH to crypt depth (CD) ratio in the duodenum, jejunum, and ileum. The lowest (p < 0.05) CD in the duodenum, jejunum and ileum was also recorded in birds fed PPPM4 diet. Birds fed PPPM8 diet had higher (p < 0.05) values for white blood cell count, red blood cell count, haemoglobin concentration and packed cell volume, whereas the lowest (p < 0.05) concentration of serum aspartate transaminase was recorded in birds fed PPPM4 diet. Birds on PPM4 diet had longer (p < 0.05) bones. Bone weight and bone breaking strength were highest (p < 0.05) in birds fed PPPM8 diet. Tibia zinc and iron concentrations increased as the inclusion levels of pomegranate peel powder meal increased. It was concluded that broiler birds require 4 g/kg pomegranate peel powder for enhanced growth performance, nutrient digestibility, gut histology, quality, and antioxidant enzyme activity of meat, whereas 8 g/kg pomegranate peel powder meal supplementation is required for enhanced heamato-biochemical indices, bone quality, fatty acid composition and lipid peroxidative parameters in broiler birds. , Thesis (PhD) -- Faculty of Science and Agriculture, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Akuru, Eunice Amaka https://orcid.org/0000-0002-3093-0247
- Date: 2022-04
- Subjects: Broilers (Chickens) , Meat -- Quality
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/23611 , vital:58218
- Description: The objective of the current study was to investigate the overall response of broiler birds to varying dietary levels of pomegranate (Punica granatum L) peel powder meal (PPPM). A total of 432-day-old Cobb 500 broiler chicks were randomly divided into six experimental groups of four replications with 18 birds per replicate in a completely randomized design (CRD). The birds were fed isonitrogenous and isocaloric experimental diets designated as: T1-control diet with 0percent additives (negative control; NEGCON); T2- control diet supplemented with α-tocopherol acetate at 200g per ton (positive control; POSCON): T3, T4, T5 and T6-control diet supplemented with 2, 4, 6 and 8g/kg PPPM (PPPM2, PPPM4, PPPM6, PPPM8). The phytochemical, nutritional and antioxidant properties of the pomegranate peel powder were determined. Results showed that the South African-grown pomegranate peel (“Wonderful” variety) had rich protein and trace mineral contents. Higher (p < 0.05) antioxidant and hepatic anti-lipid peroxidative activities were recorded in the ethanol and acetone extracts than the water extract, whereas the three extracts had no toxic effects on liver and kidney cells (p > 0.05). The dietary effects of PPPM supplementation on growth performance, digestibility, carcass, and organ weight indices of Cobb 500 birds were determined. The POSCON diet enhanced (p < 0.05) feed conversion ratio (FCR) at week 3. The average final body weight and average daily weight gain were highest (p < 0.05) in birds fed PPPM2 and PPPM4 diets, whereas birds fed PPPM2 diet had enhanced (p < 0.05) FCR and protein efficiency ratio when compared with birds on POSCON. Thigh and breast weights were highest (p < 0.05) in birds on PPPM4 and PPPM8 diets, whereas birds fed PPPM4 diet had enhanced (p < 0.05) nutrient digestibility compared with those on POSCON. The antioxidant status and breast meat quality of Cobb 500 broiler birds fed diets supplemented with PPPM were determined. Meat from birds fed PPPM8 diet had the highest (p < 0.05) thawing loss, while cooking loss was lowest (p < 0.05) in the PPPM2 group. The highest (p < 0.05) ability to scavenge ABTS [(2, 2-azinobis (3ethylbenzothiazoline-6 sulfonic acid))] radical cation (ABTS+) was recorded in the PPPM2 and PPPM4 meat while PPPM8 meat had increased (p < 0.05) catalase activity. The fatty acid composition, oxidative status, and drip loss in breast meat of Cobb 500 broiler birds fed graded levels of PPPM was determined. Meat from birds fed PPPM4 diet had the lowest (p < 0.05) margaric (C17:0) and arachidic (C20:0) acids, while meat from birds fed PPPM8 diet had higher (p < 0.05) levels of eicosadenoic (C20:2, n-6) and arachidonic (AA, 20:4) acids. The POSCON had higher (p < 0.05) ability to reduce TBARS levels in meat on day-1 and day-16 of storage than the NEGCON and PPPM diets, whereas TBARS levels were lowest (p < 0.05) in PPPM6 meat on day-16. The gut pH, histology, haematology, serum-biochemical indices, and bone quality parameters of Cobb 500 broiler birds fed diets supplemented with PPPM was determined. Birds fed POSCON, PPM2 and PPPM4 diets had the lowest (p < 0.05) pH in the duodenum, jejunum, and caecum, whereas duodenal pH values were lowest (p < 0.05) in birds fed PPPM2 and PPPM4 diets compared with birds on NEGCON. Birds fed PPPM4 diet had the highest (p < 0.01) duodenal, jejunal and ileal villi height (VH), and the highest (p < 0.01) VH to crypt depth (CD) ratio in the duodenum, jejunum, and ileum. The lowest (p < 0.05) CD in the duodenum, jejunum and ileum was also recorded in birds fed PPPM4 diet. Birds fed PPPM8 diet had higher (p < 0.05) values for white blood cell count, red blood cell count, haemoglobin concentration and packed cell volume, whereas the lowest (p < 0.05) concentration of serum aspartate transaminase was recorded in birds fed PPPM4 diet. Birds on PPM4 diet had longer (p < 0.05) bones. Bone weight and bone breaking strength were highest (p < 0.05) in birds fed PPPM8 diet. Tibia zinc and iron concentrations increased as the inclusion levels of pomegranate peel powder meal increased. It was concluded that broiler birds require 4 g/kg pomegranate peel powder for enhanced growth performance, nutrient digestibility, gut histology, quality, and antioxidant enzyme activity of meat, whereas 8 g/kg pomegranate peel powder meal supplementation is required for enhanced heamato-biochemical indices, bone quality, fatty acid composition and lipid peroxidative parameters in broiler birds. , Thesis (PhD) -- Faculty of Science and Agriculture, 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
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
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
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
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
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
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
Design, synthesis, characterization and evaluation of Chitosan-based hydrogel for controlled drug delivery system
- Authors: Safari, Justin Bazibuhe
- Date: 2022-04
- Subjects: Chitosan , Drug delivery systems , Drugs Controlled release , Tenofovir , Colloids , Hepatitis B Chemotherapy , Hydrogel
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/232182 , vital:49969
- Description: Hepatitis B infection is a deadly infectious disease caused by the hepatitis B virus and is responsible for many deaths every year worldwide. Despite medication and vaccines against hepatitis B infection, it still presents high morbidity and mortality among populations. This is partly due to factors such as a long medication period of the existing treatments, resulting in poor patient compliance and leading to treatment failure. In addition, this situation can be responsible for the observed emerging drug resistance. Hence, novel drugs and drug delivery systems are needed to tackle this matter. Many strategies have been used to develop long-acting drug delivery systems treatment for several infectious diseases. Hydrogel drug delivery systems have shown interesting results as controlled drug delivery systems for several drugs. Therefore, the present study aimed to develop chitosan grafted poly (acrylamide-co-acrylic acid) hydrogel and apply it as a pH-sensitive controlled delivery system of tenofovir disoproxil fumarate (TDF). TDF is a nucleoside reverse transcriptase inhibitor used as first-line treatment of hepatitis B chronic infection and in the treatment of other viral infections. The free-radical polymerization method was utilized to modify chitosan by grafting acrylamide and acrylic acid and using N, N’-methylene bisacrylamide as the crosslinking agent to prepare the hydrogel, followed by an optimization of parameters that could affect the swelling capacity. The prepared chitosan-g-poly(acrylamide-co-acrylic acid) hydrogel was characterized using Fourier Transmission Infra-red spectroscopy (FTIR), X-Ray Diffraction (XRD), Thermal Gravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), Energy-dispersive X-ray spectroscopy (EDS), Scanning Electron Microscopy (SEM), and was evaluated for cytotoxicity using a HeLa cell assay. TDF was used as a drug model, it was loaded by the swelling equilibrium method, following by the investigation of the release profile of TDF-loaded hydrogel at pH 1.2 and 7.4. A successful synthesis of chitosan grafted poly(acrylamide-co-acrylic acid) hydrogel was confirmed by Fourier Transmission Infra-red spectroscopy (FTIR), X-Ray Diffraction Spectroscopy (XRD), Thermal Gravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), Energy-dispersive X-ray spectroscopy (EDS) and Scanning Electron Microscopy (SEM). Optimization results showed that the ratio of monomers impacted the swelling ratio of the hydrogel and both the concentration of the crosslinking agent, and the reaction initiator also affected the swelling ratio. The synthesized hydrogels were sensitive to pH and ionic strength. Hydrogel swelling was lower in acidic solutions and higher in neutral and basic solutions and decreased with the increasing ionic strength. Furthermore, SEM results revealed that hydrogel have a rough and fibrous surface structure with numerous pores. Cytotoxicity studies demonstrated that the hydrogel was non-cytotoxic at 50 μg/ml against HeLa cells which suggested a good biocompatibility of the material. TDF was loaded and released from the hydrogels and showed an encapsulation efficiency and drug loading percentage ranging from 81-96% and 8-10%, respectively. TDF release profile was found to be low in buffer solution of pH 1.2 (in the range of 5-10%) and much higher (38-53%) at pH 7.4 within 96 hours. TDF maintained its chemical integrity after release and the hydrogels can therefore be proposed as a new controlled-release drug delivery system for hepatitis B treatment. , Thesis (MSc) -- Faculty of Science, Chemistry, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Safari, Justin Bazibuhe
- Date: 2022-04
- Subjects: Chitosan , Drug delivery systems , Drugs Controlled release , Tenofovir , Colloids , Hepatitis B Chemotherapy , Hydrogel
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/232182 , vital:49969
- Description: Hepatitis B infection is a deadly infectious disease caused by the hepatitis B virus and is responsible for many deaths every year worldwide. Despite medication and vaccines against hepatitis B infection, it still presents high morbidity and mortality among populations. This is partly due to factors such as a long medication period of the existing treatments, resulting in poor patient compliance and leading to treatment failure. In addition, this situation can be responsible for the observed emerging drug resistance. Hence, novel drugs and drug delivery systems are needed to tackle this matter. Many strategies have been used to develop long-acting drug delivery systems treatment for several infectious diseases. Hydrogel drug delivery systems have shown interesting results as controlled drug delivery systems for several drugs. Therefore, the present study aimed to develop chitosan grafted poly (acrylamide-co-acrylic acid) hydrogel and apply it as a pH-sensitive controlled delivery system of tenofovir disoproxil fumarate (TDF). TDF is a nucleoside reverse transcriptase inhibitor used as first-line treatment of hepatitis B chronic infection and in the treatment of other viral infections. The free-radical polymerization method was utilized to modify chitosan by grafting acrylamide and acrylic acid and using N, N’-methylene bisacrylamide as the crosslinking agent to prepare the hydrogel, followed by an optimization of parameters that could affect the swelling capacity. The prepared chitosan-g-poly(acrylamide-co-acrylic acid) hydrogel was characterized using Fourier Transmission Infra-red spectroscopy (FTIR), X-Ray Diffraction (XRD), Thermal Gravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), Energy-dispersive X-ray spectroscopy (EDS), Scanning Electron Microscopy (SEM), and was evaluated for cytotoxicity using a HeLa cell assay. TDF was used as a drug model, it was loaded by the swelling equilibrium method, following by the investigation of the release profile of TDF-loaded hydrogel at pH 1.2 and 7.4. A successful synthesis of chitosan grafted poly(acrylamide-co-acrylic acid) hydrogel was confirmed by Fourier Transmission Infra-red spectroscopy (FTIR), X-Ray Diffraction Spectroscopy (XRD), Thermal Gravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), Energy-dispersive X-ray spectroscopy (EDS) and Scanning Electron Microscopy (SEM). Optimization results showed that the ratio of monomers impacted the swelling ratio of the hydrogel and both the concentration of the crosslinking agent, and the reaction initiator also affected the swelling ratio. The synthesized hydrogels were sensitive to pH and ionic strength. Hydrogel swelling was lower in acidic solutions and higher in neutral and basic solutions and decreased with the increasing ionic strength. Furthermore, SEM results revealed that hydrogel have a rough and fibrous surface structure with numerous pores. Cytotoxicity studies demonstrated that the hydrogel was non-cytotoxic at 50 μg/ml against HeLa cells which suggested a good biocompatibility of the material. TDF was loaded and released from the hydrogels and showed an encapsulation efficiency and drug loading percentage ranging from 81-96% and 8-10%, respectively. TDF release profile was found to be low in buffer solution of pH 1.2 (in the range of 5-10%) and much higher (38-53%) at pH 7.4 within 96 hours. TDF maintained its chemical integrity after release and the hydrogels can therefore be proposed as a new controlled-release drug delivery system for hepatitis B treatment. , Thesis (MSc) -- Faculty of Science, Chemistry, 2022
- Full Text:
- Date Issued: 2022-04