Pregnant women’s construction of social support from their intimate partners during pregnancy
- Authors: Bottoman, Phathiswa Esona
- Date: 2018
- Subjects: Pregnant women -- South Africa -- Eastern Cape -- Relations with men Pregnancy -- Psychological aspects Pregnant women -- Social conditions
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/62560 , vital:28207
- Description: There is a growing body of research aimed at understanding social support during pregnancy in South Africa. Pregnancy is constantly referred to as one of the challenging and stressful periods affecting women’s physical and psychological well-being. Various research studies on social support argue that social support is paramount at this stage. Research on social support indicates that having adequate and quality social support impacts on how pregnant women experience pregnancy. My interest in social support comes in the wake of absent fathers in South Africa and with the emerging trend of “new” fathers. Although there is a volume of research on social support, it tends to be realist. Using a social constructionist framework, I explore other ways of talking about social support in an attempt to expand the discourse around social support. I explore how pregnant women talk about social support during pregnancy from their intimate partners in the small rural municipality of Elundini, Eastern Cape, South Africa. Intimate partner support was limited to heterosexual partners regardless of their marital status. The sampling procedure followed a non-probability sampling method. Participants of the study were between 24 and 32 years old. Their gestational age ranged between five and eight months. Fourteen in-depth interviews using photo-elicitation were conducted with seven participants and were analysed using a social constructionist informed thematic analysis. The major theme that emerged from the analysis was partner involvement and absence during pregnancy. The analysis of results suggests that expectant father presence translates to social support. Participants constructed his presence as reassurance in the context of possible abandonment. Absence was constructed in different ways: participants constructed absence as unjust and unfair, absence and marriage, temporary absence in the form of cultural phenomenon of ukwaliswa/ukubukubazana, absence as normal but burdening to the pregnant women’s social network. Participants reported that social support from the expectant father affected pregnancy wantedness.
- Full Text:
- Date Issued: 2018
- Authors: Bottoman, Phathiswa Esona
- Date: 2018
- Subjects: Pregnant women -- South Africa -- Eastern Cape -- Relations with men Pregnancy -- Psychological aspects Pregnant women -- Social conditions
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/62560 , vital:28207
- Description: There is a growing body of research aimed at understanding social support during pregnancy in South Africa. Pregnancy is constantly referred to as one of the challenging and stressful periods affecting women’s physical and psychological well-being. Various research studies on social support argue that social support is paramount at this stage. Research on social support indicates that having adequate and quality social support impacts on how pregnant women experience pregnancy. My interest in social support comes in the wake of absent fathers in South Africa and with the emerging trend of “new” fathers. Although there is a volume of research on social support, it tends to be realist. Using a social constructionist framework, I explore other ways of talking about social support in an attempt to expand the discourse around social support. I explore how pregnant women talk about social support during pregnancy from their intimate partners in the small rural municipality of Elundini, Eastern Cape, South Africa. Intimate partner support was limited to heterosexual partners regardless of their marital status. The sampling procedure followed a non-probability sampling method. Participants of the study were between 24 and 32 years old. Their gestational age ranged between five and eight months. Fourteen in-depth interviews using photo-elicitation were conducted with seven participants and were analysed using a social constructionist informed thematic analysis. The major theme that emerged from the analysis was partner involvement and absence during pregnancy. The analysis of results suggests that expectant father presence translates to social support. Participants constructed his presence as reassurance in the context of possible abandonment. Absence was constructed in different ways: participants constructed absence as unjust and unfair, absence and marriage, temporary absence in the form of cultural phenomenon of ukwaliswa/ukubukubazana, absence as normal but burdening to the pregnant women’s social network. Participants reported that social support from the expectant father affected pregnancy wantedness.
- Full Text:
- Date Issued: 2018
Largest reported groups for the Indo-Pacific bottlenose dolphin (Tursiops aduncus) found in Algoa Bay, South Africa: trends and potential drivers
- Bouveroux, Thibaut N, Caputo, Michelle, Froneman, P William, Plön, Stephanie
- Authors: Bouveroux, Thibaut N , Caputo, Michelle , Froneman, P William , Plön, Stephanie
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67913 , vital:29168 , https://doi.org/10.1111/mms.12471
- Description: Publisher version , This study investigates how group size of Indo‐Pacific bottlenose dolphins (Tursiops aduncus) changes temporally, spatially, and/or with predominant behavior at two discreet sites along the Eastern Cape coastline of South Africa: Algoa Bay and the Wild Coast. The mean group size of bottlenose dolphins was large with an average of 52 animals. Significantly larger groups were observed in Algoa Bay ( = 60, range = 1–600) than off the Wild Coast ( = 32.9, range = 1–250). In Algoa Bay, the mean group size increased significantly over the study period, from an average 18 animals in 2008 to 76 animals in 2016. Additionally, the largest average and maximum group sizes ever reported both in South Africa and worldwide, were recorded in Algoa Bay (maximum group size = 600). Neither season nor behavior had a significant effect on mean group size at both sites. Similarly environmental variables such as the depth and substrate type also had no influence on group size. It remains unclear which ecological drivers, such as predation risk and food availability, are leading to the large groups observed in this area, and further research on abundance and distribution of both predators and prey is necessary.
- Full Text: false
- Date Issued: 2018
- Authors: Bouveroux, Thibaut N , Caputo, Michelle , Froneman, P William , Plön, Stephanie
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67913 , vital:29168 , https://doi.org/10.1111/mms.12471
- Description: Publisher version , This study investigates how group size of Indo‐Pacific bottlenose dolphins (Tursiops aduncus) changes temporally, spatially, and/or with predominant behavior at two discreet sites along the Eastern Cape coastline of South Africa: Algoa Bay and the Wild Coast. The mean group size of bottlenose dolphins was large with an average of 52 animals. Significantly larger groups were observed in Algoa Bay ( = 60, range = 1–600) than off the Wild Coast ( = 32.9, range = 1–250). In Algoa Bay, the mean group size increased significantly over the study period, from an average 18 animals in 2008 to 76 animals in 2016. Additionally, the largest average and maximum group sizes ever reported both in South Africa and worldwide, were recorded in Algoa Bay (maximum group size = 600). Neither season nor behavior had a significant effect on mean group size at both sites. Similarly environmental variables such as the depth and substrate type also had no influence on group size. It remains unclear which ecological drivers, such as predation risk and food availability, are leading to the large groups observed in this area, and further research on abundance and distribution of both predators and prey is necessary.
- Full Text: false
- Date Issued: 2018
Limitations of the random response technique and a call to implement the ballot box method for estimating recreational angler compliance using surveys:
- Bova, Christopher S, Aswani, Shankar, Farthing, Matthew W, Potts, Warren M
- Authors: Bova, Christopher S , Aswani, Shankar , Farthing, Matthew W , Potts, Warren M
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/145359 , vital:38431 , DOI: 10.1016/j.fishres.2018.06.017
- Description: Accurate estimation of the levels of non-compliance to fishing regulations is crucial in ensuring that long term sustainability goals of fisheries are met. When requesting information regarding sensitive behaviour, such as an angler’s non-compliance to regulations through direct questioning methods (DQM), their responses can be influenced by social desirability bias (SDB). Literature in human dimensions research on methods for controlling this bias is limited. There has been an emerging prevalence in the use of the random response technique (RRT), which is a method aimed at reducing SDB in questions regarding sensitive behaviour, although it has never been validated against observed data in an environmental resource use context. An alternative to the RRT, the use of a ballot box method (BBM) has been successfully implemented to reduce SDB in contingent valuation studies and is introduced in this paper as a method for reducing SDB in face-to-face survey responses regarding sensitive behaviour.
- Full Text:
- Date Issued: 2018
- Authors: Bova, Christopher S , Aswani, Shankar , Farthing, Matthew W , Potts, Warren M
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/145359 , vital:38431 , DOI: 10.1016/j.fishres.2018.06.017
- Description: Accurate estimation of the levels of non-compliance to fishing regulations is crucial in ensuring that long term sustainability goals of fisheries are met. When requesting information regarding sensitive behaviour, such as an angler’s non-compliance to regulations through direct questioning methods (DQM), their responses can be influenced by social desirability bias (SDB). Literature in human dimensions research on methods for controlling this bias is limited. There has been an emerging prevalence in the use of the random response technique (RRT), which is a method aimed at reducing SDB in questions regarding sensitive behaviour, although it has never been validated against observed data in an environmental resource use context. An alternative to the RRT, the use of a ballot box method (BBM) has been successfully implemented to reduce SDB in contingent valuation studies and is introduced in this paper as a method for reducing SDB in face-to-face survey responses regarding sensitive behaviour.
- Full Text:
- Date Issued: 2018
Limitations of the random response technique and a call to implement the ballot box method for estimating recreational angler compliance using surveys
- Bova, Christopher S, Aswani, Shankar, Farthing, Matthew W, Potts, Warren M
- Authors: Bova, Christopher S , Aswani, Shankar , Farthing, Matthew W , Potts, Warren M
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/421197 , vital:71828 , xlink:href="https://doi.org/10.1016/j.fishres.2018.06.017"
- Description: Accurate estimation of the levels of non-compliance to fishing regulations is crucial in ensuring that long term sustainability goals of fisheries are met. When requesting information regarding sensitive behaviour, such as an angler’s non-compliance to regulations through direct questioning methods (DQM), their responses can be influenced by social desirability bias (SDB). Literature in human dimensions research on methods for controlling this bias is limited. There has been an emerging prevalence in the use of the random response technique (RRT), which is a method aimed at reducing SDB in questions regarding sensitive behaviour, although it has never been validated against observed data in an environmental resource use context. An alternative to the RRT, the use of a ballot box method (BBM) has been successfully implemented to reduce SDB in contingent valuation studies and is introduced in this paper as a method for reducing SDB in face-to-face survey responses regarding sensitive behaviour. The RRT, BBM and a baseline DQM were compared for accuracy in obtaining honest responses from non-compliant anglers in South Africa’s recreational marine based shore fishery (MBSF) who were covertly observed violating various regulations. A total of 79.6% of anglers who were interviewed using the BBM admitted to breaking the observed regulation. However, only 46.5% and 38.5% of the anglers who were interviewed using the DQM and RRT admitted to breaking the regulations. The length of the angler interview using the RRT was also significantly longer than the BBM and DQM. These results suggest that the BBM is the most accurate and practical method for reducing SDB in compliance surveys.
- Full Text:
- Date Issued: 2018
- Authors: Bova, Christopher S , Aswani, Shankar , Farthing, Matthew W , Potts, Warren M
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/421197 , vital:71828 , xlink:href="https://doi.org/10.1016/j.fishres.2018.06.017"
- Description: Accurate estimation of the levels of non-compliance to fishing regulations is crucial in ensuring that long term sustainability goals of fisheries are met. When requesting information regarding sensitive behaviour, such as an angler’s non-compliance to regulations through direct questioning methods (DQM), their responses can be influenced by social desirability bias (SDB). Literature in human dimensions research on methods for controlling this bias is limited. There has been an emerging prevalence in the use of the random response technique (RRT), which is a method aimed at reducing SDB in questions regarding sensitive behaviour, although it has never been validated against observed data in an environmental resource use context. An alternative to the RRT, the use of a ballot box method (BBM) has been successfully implemented to reduce SDB in contingent valuation studies and is introduced in this paper as a method for reducing SDB in face-to-face survey responses regarding sensitive behaviour. The RRT, BBM and a baseline DQM were compared for accuracy in obtaining honest responses from non-compliant anglers in South Africa’s recreational marine based shore fishery (MBSF) who were covertly observed violating various regulations. A total of 79.6% of anglers who were interviewed using the BBM admitted to breaking the observed regulation. However, only 46.5% and 38.5% of the anglers who were interviewed using the DQM and RRT admitted to breaking the regulations. The length of the angler interview using the RRT was also significantly longer than the BBM and DQM. These results suggest that the BBM is the most accurate and practical method for reducing SDB in compliance surveys.
- Full Text:
- Date Issued: 2018
A critical discourse analysis of the Daily Nation and the Standard’s news coverage of the 2007/2008 Kenyan elections
- Authors: Bradfield, Sarah-Jane
- Date: 2018
- Subjects: Elections -- Kenya Nairobi (Kenya) -- Newspapers Mass media -- Political aspects -- Kenya Kenya -- Politics and government , Discourse analysis Daily Nation (Nairobi, Kenya) Standard (Nairobi, Kenya)
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/63437 , vital:28411
- Description: This study investigates the Daily Nation and Standard’s news coverage of Kenya’s 2007/2008 general election and the unprecedented eruptions of violence which followed. This research responds to the question which came about as Kenyan print journalists and editors considered their role in possibly contributing to the violence, which took on an ethnic dimension. Vernacular radio has been fingered for having escalated longstanding ethnic tensions, but the role of the press has not been fully understood. In the aftermath of the violence, print journalists and editors met over a series of Round Table events in Nairobi to consider whether their conduct during the election could have encouraged violence. Although ten years have passed since this incidence, much of what happened within the Kenyan print media during and after the 2007/2008 general election remains unexplored and, largely, unexplained today. Although the pre- and post-election phases spanned months, my research is confined to purposive samples from a four-week period from 3 December 2007 to 4 January 2008. These four weeks were selected as they are roughly representative of the three phases of the national election which are considered significant to this study, namely the pre-election phase, the election, and the post-election violence. The research is concerned with analysing and understanding the coverage in the two dailies, the Daily Nation and Standard, and comparing the discursive work of the two, particularly in relation to identity and ethnicity. This study draws on cultural studies, critical discourse analysis and normative theories of the media to inform the research project. The critical discourse analysis explores the discourses articulated during and after the election, with a particular focus on issues of identity, ethnicity and incitement. Through this process the study found that both publications avoided references to ethnicity, despite this being an important factor in Kenyan politics and voter behaviour. In analysing these issues the study found that while the publications might claim to attempt to avoid fuelling tensions by not reporting on ethnicity, the disavowal comprised a silence which positioned the press in a collaborative role, in which it colluded with a powerful Kenyan state. Although a significant amount of time has gone by since the 2007/2008 elections, this study still considers the event significant in understanding the conduct of journalists during times of violence, and specifically for the future of journalism in Kenya.
- Full Text:
- Date Issued: 2018
- Authors: Bradfield, Sarah-Jane
- Date: 2018
- Subjects: Elections -- Kenya Nairobi (Kenya) -- Newspapers Mass media -- Political aspects -- Kenya Kenya -- Politics and government , Discourse analysis Daily Nation (Nairobi, Kenya) Standard (Nairobi, Kenya)
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/63437 , vital:28411
- Description: This study investigates the Daily Nation and Standard’s news coverage of Kenya’s 2007/2008 general election and the unprecedented eruptions of violence which followed. This research responds to the question which came about as Kenyan print journalists and editors considered their role in possibly contributing to the violence, which took on an ethnic dimension. Vernacular radio has been fingered for having escalated longstanding ethnic tensions, but the role of the press has not been fully understood. In the aftermath of the violence, print journalists and editors met over a series of Round Table events in Nairobi to consider whether their conduct during the election could have encouraged violence. Although ten years have passed since this incidence, much of what happened within the Kenyan print media during and after the 2007/2008 general election remains unexplored and, largely, unexplained today. Although the pre- and post-election phases spanned months, my research is confined to purposive samples from a four-week period from 3 December 2007 to 4 January 2008. These four weeks were selected as they are roughly representative of the three phases of the national election which are considered significant to this study, namely the pre-election phase, the election, and the post-election violence. The research is concerned with analysing and understanding the coverage in the two dailies, the Daily Nation and Standard, and comparing the discursive work of the two, particularly in relation to identity and ethnicity. This study draws on cultural studies, critical discourse analysis and normative theories of the media to inform the research project. The critical discourse analysis explores the discourses articulated during and after the election, with a particular focus on issues of identity, ethnicity and incitement. Through this process the study found that both publications avoided references to ethnicity, despite this being an important factor in Kenyan politics and voter behaviour. In analysing these issues the study found that while the publications might claim to attempt to avoid fuelling tensions by not reporting on ethnicity, the disavowal comprised a silence which positioned the press in a collaborative role, in which it colluded with a powerful Kenyan state. Although a significant amount of time has gone by since the 2007/2008 elections, this study still considers the event significant in understanding the conduct of journalists during times of violence, and specifically for the future of journalism in Kenya.
- Full Text:
- Date Issued: 2018
An interpretative phenomenological analysis of HIV positive individuals’ experiences of being in a support group
- Authors: Brink, Nicole
- Date: 2018
- Subjects: HIV-positive persons -- Social aspects Self-help groups AIDS (Disease) -- Patients -- Counseling of AIDS (Disease) -- Social aspects
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/62988 , vital:28351
- Description: People who have been diagnosed HIV positive often experience distress and anxiety due to uncertainties pertaining to the implications of an HIV positive status. Research has shown that support groups have always been a way for people to cope with the distress and stressful circumstances associated with health conditions such as HIV. This research investigated the role of face to face support groups in the lives of those living with HIV. The primary focus of this research project is to provide an in-depth exploration of HIV positive individuals‟ experiences of being in a support group. The study aims to explore the positive and negative experiences of being in an HIV support group and aims to gain an understanding of the role support plays in the lives of those living with HIV. A qualitative research design was used to explore the above mentioned aim. Semi-structured interviews were conducted with five individuals, (three women and two men) who had experienced HIV support groups. The interviews were transcribed and then analysed according to the principles of interpretative phenomenological analysis (IPA). The findings of this study revealed five super-ordinate themes, which revealed not only the positive and negative experiences of being in a support group, but also the challenges that the participants‟ experienced before joining the group. Getting a sense of the participants‟ experience before joining the group allowed the researcher to get a better understanding of how useful or not the support group has been in helping them deal with the challenges of living with HIV. The themes included: „struggling to survive after diagnosis‟, „struggling to cope: adopting negative coping skills‟, „experiencing a turning-point: a will to survive‟, „attending support group: a sweet experience‟ and lastly, „attending support groups: a bitter experience‟. Findings suggest that for these participants, the advantages outweighed the disadvantages of being in a support group. Therefore this study suggests that face to face support groups are a viable and even necessary option for support. These findings support previous research and literature in regards to the importance of social support in the form of support groups in effectively assisting HIV positive people in their journey to adjust to the consequence of living with HIV.
- Full Text:
- Date Issued: 2018
- Authors: Brink, Nicole
- Date: 2018
- Subjects: HIV-positive persons -- Social aspects Self-help groups AIDS (Disease) -- Patients -- Counseling of AIDS (Disease) -- Social aspects
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/62988 , vital:28351
- Description: People who have been diagnosed HIV positive often experience distress and anxiety due to uncertainties pertaining to the implications of an HIV positive status. Research has shown that support groups have always been a way for people to cope with the distress and stressful circumstances associated with health conditions such as HIV. This research investigated the role of face to face support groups in the lives of those living with HIV. The primary focus of this research project is to provide an in-depth exploration of HIV positive individuals‟ experiences of being in a support group. The study aims to explore the positive and negative experiences of being in an HIV support group and aims to gain an understanding of the role support plays in the lives of those living with HIV. A qualitative research design was used to explore the above mentioned aim. Semi-structured interviews were conducted with five individuals, (three women and two men) who had experienced HIV support groups. The interviews were transcribed and then analysed according to the principles of interpretative phenomenological analysis (IPA). The findings of this study revealed five super-ordinate themes, which revealed not only the positive and negative experiences of being in a support group, but also the challenges that the participants‟ experienced before joining the group. Getting a sense of the participants‟ experience before joining the group allowed the researcher to get a better understanding of how useful or not the support group has been in helping them deal with the challenges of living with HIV. The themes included: „struggling to survive after diagnosis‟, „struggling to cope: adopting negative coping skills‟, „experiencing a turning-point: a will to survive‟, „attending support group: a sweet experience‟ and lastly, „attending support groups: a bitter experience‟. Findings suggest that for these participants, the advantages outweighed the disadvantages of being in a support group. Therefore this study suggests that face to face support groups are a viable and even necessary option for support. These findings support previous research and literature in regards to the importance of social support in the form of support groups in effectively assisting HIV positive people in their journey to adjust to the consequence of living with HIV.
- Full Text:
- Date Issued: 2018
Energy maximisation strategies of different African herbivores in a fire dominated and nutrient poor grassland ecosystem
- Authors: Brooke, Christopher
- Date: 2018
- Subjects: Grassland ecology -- South Africa -- Eastern Cape , Animals -- Food -- South Africa -- Eastern Cape , Herbivores -- Ecology -- South Africa -- Eastern Cape , Fire ecology -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/21961 , vital:29807
- Description: Fire and herbivory are both major drivers in grassland ecosystems throughout the world. Although these two driving forces act independently from one another the relationship between fire and herbivory may be more significant than either acting on their own. Heterogeneity within the landscape as a result of fire results in herbivores having to adapt their behaviour in space and time. My research focussed on 1) characterising the fire regime on Mkambati Nature Reserve (hereafter Mkambati) and 2) determining the foraging choices and energy maximisation principles displayed by herbivores in relation to the biomass of vegetation and post fire vegetation age. Fire regimes were characterised between 2007-2016 in the low nutrient coastal grasslands of Mkambati in terms of fire season, seasonality of fire-prone weather conditions, fire return interval (FRI) and influence of poaching-related ignitions. Based on these results I then assessed foraging choices in terms of energy maximisation of four large herbivore species. I explored what energy maximisation strategy was employed, i.e. maximisation of daily digestible energy (DDE) (recently burnt low biomass vegetation) or instantaneous digestible energy (IDE) (older high biomass vegetation), by herbivore species with different morpho-physiological traits. Common reedbuck (Redunca arundinum), red hartebeest (Alcelaphus buselaphus subsp. caama), zebra (Equus quagga) and eland (Tragelaphus oryx subsp. oryx) were fitted with GPS satellite tracking collars, and hourly GPS locations (observed) were taken between 2008 and 2016. Using mixed effects models, I compared observed and an associated set of random locations to determine the energy maximisation strategy employed by each species. Our results indicated that fires were concentrated in winter when monthly fire danger weather (FDI) was highest. The mean FRI at Mkambati was <3 years, but varied according to vegetation type, and whether censoring (for open ended FRIs) was applied to estimate mean FRIs. Poachers, with the intention of attracting ungulates, are an important source of ignition at Mkambati. Accordingly FRIs were shorter (approximately 2 years) in areas within 3 km of likely poacher entry points. Although all fires recorded at Mkambati during the study period were of anthropogenic origin, mean FRI still fell within the natural range reported for interior grasslands in South Africa. Based on these findings, underpinned by the fire regime information, I showed that red hartebeest and zebra maximised DDE inside and outside of fire seasons and frequently foraged in low biomass recently burnt grasslands. Eland generally favoured areas where they could maximise IDE outside of the fire season, however during the fire season they switched strategy to maximise DDE. Reedbuck did not maximise IDE or DDE at the same scale (patch scale) as the other species, but at a landscape (broader) scale they maximised both IDE and DDE. Through this research I have shown how regular fire affects the foraging and energy maximisation behaviour of large African herbivores and how morpho-physiological traits affect these decisions. In response to these results I recommend that the management of Mkambati implement a focused monitoring program comparing the frequently and less frequently burnt areas of the reserve in order to understand the complex effects of anthropogenic fire and its subsequent effects on the biota of Mkambati.
- Full Text:
- Date Issued: 2018
- Authors: Brooke, Christopher
- Date: 2018
- Subjects: Grassland ecology -- South Africa -- Eastern Cape , Animals -- Food -- South Africa -- Eastern Cape , Herbivores -- Ecology -- South Africa -- Eastern Cape , Fire ecology -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/21961 , vital:29807
- Description: Fire and herbivory are both major drivers in grassland ecosystems throughout the world. Although these two driving forces act independently from one another the relationship between fire and herbivory may be more significant than either acting on their own. Heterogeneity within the landscape as a result of fire results in herbivores having to adapt their behaviour in space and time. My research focussed on 1) characterising the fire regime on Mkambati Nature Reserve (hereafter Mkambati) and 2) determining the foraging choices and energy maximisation principles displayed by herbivores in relation to the biomass of vegetation and post fire vegetation age. Fire regimes were characterised between 2007-2016 in the low nutrient coastal grasslands of Mkambati in terms of fire season, seasonality of fire-prone weather conditions, fire return interval (FRI) and influence of poaching-related ignitions. Based on these results I then assessed foraging choices in terms of energy maximisation of four large herbivore species. I explored what energy maximisation strategy was employed, i.e. maximisation of daily digestible energy (DDE) (recently burnt low biomass vegetation) or instantaneous digestible energy (IDE) (older high biomass vegetation), by herbivore species with different morpho-physiological traits. Common reedbuck (Redunca arundinum), red hartebeest (Alcelaphus buselaphus subsp. caama), zebra (Equus quagga) and eland (Tragelaphus oryx subsp. oryx) were fitted with GPS satellite tracking collars, and hourly GPS locations (observed) were taken between 2008 and 2016. Using mixed effects models, I compared observed and an associated set of random locations to determine the energy maximisation strategy employed by each species. Our results indicated that fires were concentrated in winter when monthly fire danger weather (FDI) was highest. The mean FRI at Mkambati was <3 years, but varied according to vegetation type, and whether censoring (for open ended FRIs) was applied to estimate mean FRIs. Poachers, with the intention of attracting ungulates, are an important source of ignition at Mkambati. Accordingly FRIs were shorter (approximately 2 years) in areas within 3 km of likely poacher entry points. Although all fires recorded at Mkambati during the study period were of anthropogenic origin, mean FRI still fell within the natural range reported for interior grasslands in South Africa. Based on these findings, underpinned by the fire regime information, I showed that red hartebeest and zebra maximised DDE inside and outside of fire seasons and frequently foraged in low biomass recently burnt grasslands. Eland generally favoured areas where they could maximise IDE outside of the fire season, however during the fire season they switched strategy to maximise DDE. Reedbuck did not maximise IDE or DDE at the same scale (patch scale) as the other species, but at a landscape (broader) scale they maximised both IDE and DDE. Through this research I have shown how regular fire affects the foraging and energy maximisation behaviour of large African herbivores and how morpho-physiological traits affect these decisions. In response to these results I recommend that the management of Mkambati implement a focused monitoring program comparing the frequently and less frequently burnt areas of the reserve in order to understand the complex effects of anthropogenic fire and its subsequent effects on the biota of Mkambati.
- Full Text:
- Date Issued: 2018
The role of field and garden cultivation for food security under a changing climate: the case of Fairbairn and Ntloko villages, Eastern Cape
- Authors: Brooks, Haydn
- Date: 2018
- Subjects: Climatic changes -- Economic aspects -- Eastern Cape (South Africa) , Climatic changes -- Social aspects -- South Africa , Food -- Economic aspects -- South Africa , Food security -- South Africa -- Eastern Cape
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/58013 , vital:27019
- Description: The world is becoming more complex due to the increasing occurrence of social-ecological change. This is particularly evident in the developing world, especially on the African continent, where existing vulnerabilities (i.e. endemic poverty, weak governance, overpopulation and HIV/AIDS) are being exacerbated by the impact of climate change. Climate change poses a very real threat to millions of Africans, especially those who rely on the natural world for their livelihoods. The increasing variability of climate and rainfall patterns are said to have dire consequences on agricultural production which is the main livelihood activity of rural dwellers across the continent. The impacts of such change and variability include, changes in the frequency and intensity of droughts, flooding and heavy storms, leading to worsening soil conditions, desertification as well as disease and pest out-breaks which will likely result in reduced crop and livestock yields. A reduction in agricultural production will likely have a negative effect on the food security of millions of people. This study was conducted in the Eastern Cape of South Africa, in two rural villages, Fairbairn and Ntloko located in the former Ciskei homeland, with the purpose of exploring the nexus between climate change, cultivation and food security. This study combined social-ecological thinking with that of political ecology to create a robust lens, in which to analyse the complex interactions between humans and the environment. A mixed methods approach was used to gather the data which consisted of a household survey, using a structured questionnaire as well as semi-structured interviews with various respondents. Quantitative data were analysed using Excel and Statistica 13, whilst coding was used for qualitative data. The main aim of the study was to explore the extent and characteristics of cultivation in the two study sites, the role of household food production in food security as well as the challenges that local cultivator’s face with regards to climate change. In recent decades, there has been a decline in rural agricultural production with many fields that were previously cultivated, lying vacant and unused. However, as this study found, cultivation is still important as over 50% of sampled households cultivated a small area within the homestead. This was mainly done to supplement household food expenditure in order to save cash incomes. The results also found that although participants had perceived negative changes in climate and rainfall (amount, onset, duration), it was not considered the most important challenge for own production. Rather, lack of fencing and capital were seen as major hindrances to efficient own production. Understanding the complexity of own production and food security under a changing climate can help form better and more resilient policies and strategies for rural development, in addition to strengthening future livelihoods of rural people in an ever changing world.
- Full Text:
- Date Issued: 2018
- Authors: Brooks, Haydn
- Date: 2018
- Subjects: Climatic changes -- Economic aspects -- Eastern Cape (South Africa) , Climatic changes -- Social aspects -- South Africa , Food -- Economic aspects -- South Africa , Food security -- South Africa -- Eastern Cape
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/58013 , vital:27019
- Description: The world is becoming more complex due to the increasing occurrence of social-ecological change. This is particularly evident in the developing world, especially on the African continent, where existing vulnerabilities (i.e. endemic poverty, weak governance, overpopulation and HIV/AIDS) are being exacerbated by the impact of climate change. Climate change poses a very real threat to millions of Africans, especially those who rely on the natural world for their livelihoods. The increasing variability of climate and rainfall patterns are said to have dire consequences on agricultural production which is the main livelihood activity of rural dwellers across the continent. The impacts of such change and variability include, changes in the frequency and intensity of droughts, flooding and heavy storms, leading to worsening soil conditions, desertification as well as disease and pest out-breaks which will likely result in reduced crop and livestock yields. A reduction in agricultural production will likely have a negative effect on the food security of millions of people. This study was conducted in the Eastern Cape of South Africa, in two rural villages, Fairbairn and Ntloko located in the former Ciskei homeland, with the purpose of exploring the nexus between climate change, cultivation and food security. This study combined social-ecological thinking with that of political ecology to create a robust lens, in which to analyse the complex interactions between humans and the environment. A mixed methods approach was used to gather the data which consisted of a household survey, using a structured questionnaire as well as semi-structured interviews with various respondents. Quantitative data were analysed using Excel and Statistica 13, whilst coding was used for qualitative data. The main aim of the study was to explore the extent and characteristics of cultivation in the two study sites, the role of household food production in food security as well as the challenges that local cultivator’s face with regards to climate change. In recent decades, there has been a decline in rural agricultural production with many fields that were previously cultivated, lying vacant and unused. However, as this study found, cultivation is still important as over 50% of sampled households cultivated a small area within the homestead. This was mainly done to supplement household food expenditure in order to save cash incomes. The results also found that although participants had perceived negative changes in climate and rainfall (amount, onset, duration), it was not considered the most important challenge for own production. Rather, lack of fencing and capital were seen as major hindrances to efficient own production. Understanding the complexity of own production and food security under a changing climate can help form better and more resilient policies and strategies for rural development, in addition to strengthening future livelihoods of rural people in an ever changing world.
- Full Text:
- Date Issued: 2018
Investigating combinations of feature extraction and classification for improved image-based multimodal biometric systems at the feature level
- Authors: Brown, Dane
- Date: 2018
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/63470 , vital:28414
- Description: Multimodal biometrics has become a popular means of overcoming the limitations of unimodal biometric systems. However, the rich information particular to the feature level is of a complex nature and leveraging its potential without overfitting a classifier is not well studied. This research investigates feature-classifier combinations on the fingerprint, face, palmprint, and iris modalities to effectively fuse their feature vectors for a complementary result. The effects of different feature-classifier combinations are thus isolated to identify novel or improved algorithms. A new face segmentation algorithm is shown to increase consistency in nominal and extreme scenarios. Moreover, two novel feature extraction techniques demonstrate better adaptation to dynamic lighting conditions, while reducing feature dimensionality to the benefit of classifiers. A comprehensive set of unimodal experiments are carried out to evaluate both verification and identification performance on a variety of datasets using four classifiers, namely Eigen, Fisher, Local Binary Pattern Histogram and linear Support Vector Machine on various feature extraction methods. The recognition performance of the proposed algorithms are shown to outperform the vast majority of related studies, when using the same dataset under the same test conditions. In the unimodal comparisons presented, the proposed approaches outperform existing systems even when given a handicap such as fewer training samples or data with a greater number of classes. A separate comprehensive set of experiments on feature fusion show that combining modality data provides a substantial increase in accuracy, with only a few exceptions that occur when differences in the image data quality of two modalities are substantial. However, when two poor quality datasets are fused, noticeable gains in recognition performance are realized when using the novel feature extraction approach. Finally, feature-fusion guidelines are proposed to provide the necessary insight to leverage the rich information effectively when fusing multiple biometric modalities at the feature level. These guidelines serve as the foundation to better understand and construct biometric systems that are effective in a variety of applications.
- Full Text:
- Date Issued: 2018
- Authors: Brown, Dane
- Date: 2018
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/63470 , vital:28414
- Description: Multimodal biometrics has become a popular means of overcoming the limitations of unimodal biometric systems. However, the rich information particular to the feature level is of a complex nature and leveraging its potential without overfitting a classifier is not well studied. This research investigates feature-classifier combinations on the fingerprint, face, palmprint, and iris modalities to effectively fuse their feature vectors for a complementary result. The effects of different feature-classifier combinations are thus isolated to identify novel or improved algorithms. A new face segmentation algorithm is shown to increase consistency in nominal and extreme scenarios. Moreover, two novel feature extraction techniques demonstrate better adaptation to dynamic lighting conditions, while reducing feature dimensionality to the benefit of classifiers. A comprehensive set of unimodal experiments are carried out to evaluate both verification and identification performance on a variety of datasets using four classifiers, namely Eigen, Fisher, Local Binary Pattern Histogram and linear Support Vector Machine on various feature extraction methods. The recognition performance of the proposed algorithms are shown to outperform the vast majority of related studies, when using the same dataset under the same test conditions. In the unimodal comparisons presented, the proposed approaches outperform existing systems even when given a handicap such as fewer training samples or data with a greater number of classes. A separate comprehensive set of experiments on feature fusion show that combining modality data provides a substantial increase in accuracy, with only a few exceptions that occur when differences in the image data quality of two modalities are substantial. However, when two poor quality datasets are fused, noticeable gains in recognition performance are realized when using the novel feature extraction approach. Finally, feature-fusion guidelines are proposed to provide the necessary insight to leverage the rich information effectively when fusing multiple biometric modalities at the feature level. These guidelines serve as the foundation to better understand and construct biometric systems that are effective in a variety of applications.
- Full Text:
- Date Issued: 2018
Bioinformatics tool development with a focus on structural bioinformatics and the analysis of genetic variation in humans
- Authors: Brown, David K
- Date: 2018
- Subjects: Bioinformatics , Human genetics -- Variation , High performance computing , Workflow management systems , Molecular dynamics , Next generation sequencing , Human Mutation Analysis (HUMA)
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/60708 , vital:27820
- Description: This thesis is divided into three parts, united under the general theme of bioinformatics tool development and variation analysis. Part 1 describes the design and development of the Job Management System (JMS), a workflow management system for high performance computing (HPC). HPC has become an integral part of bioinformatics. Computational methods for molecular dynamics and next generation sequencing (NGS) analysis, which require complex calculations on large datasets, are not yet feasible on desktop computers. As such, powerful computer clusters have been employed to perform these calculations. However, making use of these HPC clusters requires familiarity with command line interfaces. This excludes a large number of researchers from taking advantage of these resources. JMS was developed as a tool to make it easier for researchers without a computer science background to make use of HPC. Additionally, JMS can be used to host computational tools and pipelines and generates both web-based interfaces and RESTful APIs for those tools. The web-based interfaces can be used to quickly and easily submit jobs to the underlying cluster. The RESTful web API, on the other hand, allows JMS to provided backend functionality for external tools and web servers that want to run jobs on the cluster. Numerous tools and workflows have already been added to JMS, several of which have been incorporated into external web servers. One such web server is the Human Mutation Analysis (HUMA) web server and database. HUMA, the topic of part 2 of this thesis, is a platform for the analysis of genetic variation in humans. HUMA aggregates data from various existing databases into a single, connected and related database. The advantages of this are realized in the powerful querying abilities that it provides. HUMA includes protein, gene, disease, and variation data and can be searched from the angle of any one of these categories. For example, searching for a protein will return the protein data (e.g. protein sequences, structures, domains and families, and other meta-data). However, the related nature of the database means that genes, diseases, variation, and literature related to the protein will also be returned, giving users a powerful and holistic view of all data associated with the protein. HUMA also provides links to the original sources of the data, allowing users to follow the links to find additional details. HUMA aims to be a platform for the analysis of genetic variation. As such, it also provides tools to visualize and analyse the data (several of which run on the underlying cluster, via JMS). These tools include alignment and 3D structure visualization, homology modeling, variant analysis, and the ability to upload custom variation datasets and map them to proteins, genes and diseases. HUMA also provides collaboration features, allowing users to share and discuss datasets and job results. Finally, part 3 of this thesis focused on the development of a suite of tools, MD-TASK, to analyse genetic variation at the protein structure level via network analysis of molecular dynamics simulations. The use of MD-TASK in combination with the tools developed in the previous parts of this thesis is showcased via the analysis of variation in the renin-angiotensinogen complex, a vital part of the renin-angiotensin system.
- Full Text:
- Date Issued: 2018
- Authors: Brown, David K
- Date: 2018
- Subjects: Bioinformatics , Human genetics -- Variation , High performance computing , Workflow management systems , Molecular dynamics , Next generation sequencing , Human Mutation Analysis (HUMA)
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/60708 , vital:27820
- Description: This thesis is divided into three parts, united under the general theme of bioinformatics tool development and variation analysis. Part 1 describes the design and development of the Job Management System (JMS), a workflow management system for high performance computing (HPC). HPC has become an integral part of bioinformatics. Computational methods for molecular dynamics and next generation sequencing (NGS) analysis, which require complex calculations on large datasets, are not yet feasible on desktop computers. As such, powerful computer clusters have been employed to perform these calculations. However, making use of these HPC clusters requires familiarity with command line interfaces. This excludes a large number of researchers from taking advantage of these resources. JMS was developed as a tool to make it easier for researchers without a computer science background to make use of HPC. Additionally, JMS can be used to host computational tools and pipelines and generates both web-based interfaces and RESTful APIs for those tools. The web-based interfaces can be used to quickly and easily submit jobs to the underlying cluster. The RESTful web API, on the other hand, allows JMS to provided backend functionality for external tools and web servers that want to run jobs on the cluster. Numerous tools and workflows have already been added to JMS, several of which have been incorporated into external web servers. One such web server is the Human Mutation Analysis (HUMA) web server and database. HUMA, the topic of part 2 of this thesis, is a platform for the analysis of genetic variation in humans. HUMA aggregates data from various existing databases into a single, connected and related database. The advantages of this are realized in the powerful querying abilities that it provides. HUMA includes protein, gene, disease, and variation data and can be searched from the angle of any one of these categories. For example, searching for a protein will return the protein data (e.g. protein sequences, structures, domains and families, and other meta-data). However, the related nature of the database means that genes, diseases, variation, and literature related to the protein will also be returned, giving users a powerful and holistic view of all data associated with the protein. HUMA also provides links to the original sources of the data, allowing users to follow the links to find additional details. HUMA aims to be a platform for the analysis of genetic variation. As such, it also provides tools to visualize and analyse the data (several of which run on the underlying cluster, via JMS). These tools include alignment and 3D structure visualization, homology modeling, variant analysis, and the ability to upload custom variation datasets and map them to proteins, genes and diseases. HUMA also provides collaboration features, allowing users to share and discuss datasets and job results. Finally, part 3 of this thesis focused on the development of a suite of tools, MD-TASK, to analyse genetic variation at the protein structure level via network analysis of molecular dynamics simulations. The use of MD-TASK in combination with the tools developed in the previous parts of this thesis is showcased via the analysis of variation in the renin-angiotensinogen complex, a vital part of the renin-angiotensin system.
- Full Text:
- Date Issued: 2018
HUMA: A platform for the analysis of genetic variation in humans
- Brown, David K, Tastan Bishop, Özlem
- Authors: Brown, David K , Tastan Bishop, Özlem
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124653 , vital:35642 , https://doi.10.1002/humu.23334
- Description: The completion of the human genome project at the beginning of the 21st century, along with the rapid advancement of sequencing technologies thereafter, has resulted in exponential growth of biological data. In genetics, this has given rise to numerous variation databases, created to store and annotate the ever-expanding dataset of known mutations. Usually, these databases focus on variation at the sequence level. Few databases focus on the analysis of variation at the 3D level, that is, mapping, visualizing, and determining the effects of variation in protein structures. Additionally, these Web servers seldom incorporate tools to help analyze these data. Here, we present the Human Mutation Analysis (HUMA) Web server and database. HUMA integrates sequence, structure, variation, and disease data into a single, connected database. A user-friendly interface provides click-based data access and visualization, whereas a RESTfulWebAPI provides programmatic access to the data. Tools have been integrated into HUMA to allow initial analyses to be carried out on the server. Furthermore, users can upload their private variation datasets, which are automatically mapped to public data and can be analyzed using the integrated tools. HUMA is freely accessible at https://huma.rubi.ru.ac.za.
- Full Text:
- Date Issued: 2018
- Authors: Brown, David K , Tastan Bishop, Özlem
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124653 , vital:35642 , https://doi.10.1002/humu.23334
- Description: The completion of the human genome project at the beginning of the 21st century, along with the rapid advancement of sequencing technologies thereafter, has resulted in exponential growth of biological data. In genetics, this has given rise to numerous variation databases, created to store and annotate the ever-expanding dataset of known mutations. Usually, these databases focus on variation at the sequence level. Few databases focus on the analysis of variation at the 3D level, that is, mapping, visualizing, and determining the effects of variation in protein structures. Additionally, these Web servers seldom incorporate tools to help analyze these data. Here, we present the Human Mutation Analysis (HUMA) Web server and database. HUMA integrates sequence, structure, variation, and disease data into a single, connected database. A user-friendly interface provides click-based data access and visualization, whereas a RESTfulWebAPI provides programmatic access to the data. Tools have been integrated into HUMA to allow initial analyses to be carried out on the server. Furthermore, users can upload their private variation datasets, which are automatically mapped to public data and can be analyzed using the integrated tools. HUMA is freely accessible at https://huma.rubi.ru.ac.za.
- Full Text:
- Date Issued: 2018
A case study of emergent environmental pedagogical content knowledge in a Fundisa for Change teacher professional development course
- Authors: Brundrit, Susan
- Date: 2018
- Subjects: Career development -- South Africa , Environmental education -- South Africa , Teachers -- Training of --South Africa , Environmental education -- Study and teaching -- South Africa , Fundisa for Change
- Language: English
- Type: text , Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/62850 , vital:28301
- Description: This study set out to explore and describe in the form of a qualitative case study, an iteration of a Fundisa for Change teacher professional development programme, in this case the Teaching Life & Living short course presented to seventeen teachers as part of their Advanced Certificate in Teaching (ACT) Senior Phase Natural Sciences, at the University of Cape Town. The focus of the research was on describing how the development of teacher environmental pedagogical content knowledge (PCK) was supported and constructed in the course. The Consensus Model of Teacher Professional Knowledge and Skill, an outcome of the 2012 PCK Summit, was used to define the concept of PCK and also contributed the concept of amplifiers and filters as processes that mediate the development of teacher PCK. The study drew on Borko’s (2004) model of a professional development system, using the elements of course, teachers, facilitators and context as an analytical framework. Data generated included a teacher contextual profile questionnaire, audio-recordings of group work, course outputs and reflection and evaluation forms. Data analysis had two phases: the first phase concentrated on the development of analytic memos based on particular data sources whereas the second phase worked across data sources to present the evidence relating to each of the professional development system elements. The study found that teachers were supported in the development of their environmental PCK by the collaborative learning opportunities afforded by the course. Emergent PCK was organised according to five components: assessment knowledge; pedagogical knowledge; content knowledge; knowledge of learners; and, curricular knowledge. Emergent teacher learning ranged in specificity from general, to subject-specific, to domain-specific, and lastly to topic-specific knowledge. Teacher beliefs and orientations, prior knowledge and contexts brought into the professional development system were described as amplifiers and filters to teacher learning of PCK. In particular there were several contextual factors that emerged as themes from the data that had potentially filtering effects. Recommendations included that facilitators create an atmosphere conducive to collaborative learning, that evidence of learner conceptual understanding be examined during the course, that teachers be exposed to in-depth examples of canonical PCK and that more modelling of formative assessment strategies are presented.
- Full Text:
- Date Issued: 2018
- Authors: Brundrit, Susan
- Date: 2018
- Subjects: Career development -- South Africa , Environmental education -- South Africa , Teachers -- Training of --South Africa , Environmental education -- Study and teaching -- South Africa , Fundisa for Change
- Language: English
- Type: text , Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/62850 , vital:28301
- Description: This study set out to explore and describe in the form of a qualitative case study, an iteration of a Fundisa for Change teacher professional development programme, in this case the Teaching Life & Living short course presented to seventeen teachers as part of their Advanced Certificate in Teaching (ACT) Senior Phase Natural Sciences, at the University of Cape Town. The focus of the research was on describing how the development of teacher environmental pedagogical content knowledge (PCK) was supported and constructed in the course. The Consensus Model of Teacher Professional Knowledge and Skill, an outcome of the 2012 PCK Summit, was used to define the concept of PCK and also contributed the concept of amplifiers and filters as processes that mediate the development of teacher PCK. The study drew on Borko’s (2004) model of a professional development system, using the elements of course, teachers, facilitators and context as an analytical framework. Data generated included a teacher contextual profile questionnaire, audio-recordings of group work, course outputs and reflection and evaluation forms. Data analysis had two phases: the first phase concentrated on the development of analytic memos based on particular data sources whereas the second phase worked across data sources to present the evidence relating to each of the professional development system elements. The study found that teachers were supported in the development of their environmental PCK by the collaborative learning opportunities afforded by the course. Emergent PCK was organised according to five components: assessment knowledge; pedagogical knowledge; content knowledge; knowledge of learners; and, curricular knowledge. Emergent teacher learning ranged in specificity from general, to subject-specific, to domain-specific, and lastly to topic-specific knowledge. Teacher beliefs and orientations, prior knowledge and contexts brought into the professional development system were described as amplifiers and filters to teacher learning of PCK. In particular there were several contextual factors that emerged as themes from the data that had potentially filtering effects. Recommendations included that facilitators create an atmosphere conducive to collaborative learning, that evidence of learner conceptual understanding be examined during the course, that teachers be exposed to in-depth examples of canonical PCK and that more modelling of formative assessment strategies are presented.
- Full Text:
- Date Issued: 2018
The contribution of small-scale fisheries to rural livelihoods and food security : evidence from Hamburg, Eastern Cape Province, South Africa
- Authors: Budaza, Nwabisa
- Date: 2018
- Subjects: Small-scale fisheries -- South Africa -- Eastern Cape Food supply -- South Africa -- Eastern Cape Fishery management -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/10338 , vital:35396
- Description: Small-scale fisheries are known to provide food and income to millions of people around the world, but their role and existence is often ignored in development planning. The growing human demand for animal protein has become one of the foremost world challenges for which aquatic organisms have a significant role to play. In South Africa, small-scale fisheries have been recognized since the end of Apartheid, but the extent of the contribution of the sector to rural livelihoods and food security is not well understood. Using data drawn from a sample of 80 fishers in the coastal community of Hamburg, Eastern Cape, this dissertation presents an assessment of the contribution of small-scale fisheries to rural livelihoods, income and food security. The primary data were collected from the fishers using a structured questionnaire and non-probability sampling. The data were analysed with the assistance of descriptive techniques and a few simply statistical tests. The results of the study indicate that fishers in Hamburg catch a wide range of fish, which include wild kob, octopus, spotted grunter, white/black mussel cracker and white steenbras. Fishers in the study area are not solely dependent on small-scale fisheries for their livelihoods, income and food security, but generally supplement their welfare payments with fishing in order to sustain their livelihoods. About 78percent of the surveyed fishers depend on government grants, including old age grants, child support grants and social care grant. In terms of employment, 15percent of the surveyed fishers are casually employed, while 6percent are formally employed on a contract basis. Although they are not only dependent on fishing, nevertheless fishing is an important source of livelihood, income and food security. About 37percent of the fishers harvest marine resources for home consumption, while 7percent harvest solely for income, and 56percent harvest for both home consumption and income. Income generated from fisheries is approximately R935 per month and is used to buy food, electricity, fishing equipment and other household needs. The findings from this research underline the need for interventions such as coordinated institutions, improved infrastructure, improved monitoring and enforcement systems, as well as improved access to permit/fishing rights for sustainable use of marine resources.
- Full Text:
- Date Issued: 2018
- Authors: Budaza, Nwabisa
- Date: 2018
- Subjects: Small-scale fisheries -- South Africa -- Eastern Cape Food supply -- South Africa -- Eastern Cape Fishery management -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/10338 , vital:35396
- Description: Small-scale fisheries are known to provide food and income to millions of people around the world, but their role and existence is often ignored in development planning. The growing human demand for animal protein has become one of the foremost world challenges for which aquatic organisms have a significant role to play. In South Africa, small-scale fisheries have been recognized since the end of Apartheid, but the extent of the contribution of the sector to rural livelihoods and food security is not well understood. Using data drawn from a sample of 80 fishers in the coastal community of Hamburg, Eastern Cape, this dissertation presents an assessment of the contribution of small-scale fisheries to rural livelihoods, income and food security. The primary data were collected from the fishers using a structured questionnaire and non-probability sampling. The data were analysed with the assistance of descriptive techniques and a few simply statistical tests. The results of the study indicate that fishers in Hamburg catch a wide range of fish, which include wild kob, octopus, spotted grunter, white/black mussel cracker and white steenbras. Fishers in the study area are not solely dependent on small-scale fisheries for their livelihoods, income and food security, but generally supplement their welfare payments with fishing in order to sustain their livelihoods. About 78percent of the surveyed fishers depend on government grants, including old age grants, child support grants and social care grant. In terms of employment, 15percent of the surveyed fishers are casually employed, while 6percent are formally employed on a contract basis. Although they are not only dependent on fishing, nevertheless fishing is an important source of livelihood, income and food security. About 37percent of the fishers harvest marine resources for home consumption, while 7percent harvest solely for income, and 56percent harvest for both home consumption and income. Income generated from fisheries is approximately R935 per month and is used to buy food, electricity, fishing equipment and other household needs. The findings from this research underline the need for interventions such as coordinated institutions, improved infrastructure, improved monitoring and enforcement systems, as well as improved access to permit/fishing rights for sustainable use of marine resources.
- Full Text:
- Date Issued: 2018
Performance evaluation of an off-grid building integrated photovoltaic system in Alice, Eastern Cape province, South Africa
- Authors: Buma, Carine Lethem
- Date: 2018
- Subjects: Building-integrated photovoltaic systems Buildings -- Energy conservation Performance -- Evaluation
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/13227 , vital:39623
- Description: The constant increase in the global demand for energy and the current crisis on global warming and climate change has prompted a dying quest for clean, sustainable and reliable sources of energy. Amongst numerous renewable energy technologies, harnessing energy from the sun is the most viable way of guaranteeing a clean and sustainable supply of energy. Also, photovoltaic energy is one of the ways of using energy from the sun, where sunlight is converted to electricity using photovoltaic panels. Furthermore, the integration of photovoltaic modules into buildings is one of the most elegant innovations of this technology, as it plays the dual role of supplying energy to the building as well as protecting the building from outdoor weather conditions. Moreover, operating off the grid offers the possibility of energy access to locations far off from the grid and individuals willing to gain some degree of energy independence. Evaluating the performance of existing off grid and/or building integrated photovoltaic systems is the key to guaranteeing sustainable development and advancement in the technology. Thus, the aim of this work was to evaluate the performance of an off-grid building integrated photovoltaic system that was installed at the Fort Hare Institute of Technology. This entailed performing an in-depth characterisation of the solar resource at this location, evaluating the performance of the modules under outdoor weather conditions and also evaluating the performance of the balance of system (BOS) components. The system was monitored for a period of nine months (between February and October 2017). A data acquisition system was designed for measuring and recording both electrical system parameters and meteorological parameters affecting the performance of the system. These meteorological parameters include; solar irradiance, ambient temperature, cell temperature, relative humidity, wind speed and direction. A detailed characterisation of the solar resource at this location was carried out. It was observed that the solar declination angle varied from -23.5o on the summer solstice to 23.5o on the winter solstice. Also, the solar altitude angle (at solar noon) which is a complementary angle to the zenith angle varied from 33.7o in June to 80.65o in December. During the summer months, longer day lengths were experienced because the sun traversed the sky over a longer time, rising south of east and setting south of west. Whereas, in the winter months, the path length of the sun was shorter, with the sun rising north of east and setting north of west, hence, shorter day lengths. The solar radiation incident on a 25o north facing solar collector was found to be in three components; beam, diffuse and reflected. The beam component was higher in summer whereas the diffuse component was higher in winter due to an increase in the air mass ratio. However, the total daily average radiation was highest in January (7.12 peak sun hours) and least in June (3.04 peak sun hours). Finally, a comparison between the calculated and measured values of solar radiation showed just a 1.1percent difference over the year with disparities being in the individual months.m The influence of outdoor weather conditions on the performance of the system was also evaluated. Operating temperatures were noticed to have a great impact on the output voltage and power of the PV array. Significant correlations existed between various meteorological parameters. Also, a multiple linear regression model was developed to ascertain the dependence of module temperature on solar irradiance, ambient temperature, relative humidity, wind speed and wind direction. The coefficient of determination for the model was 0.928, showing a strong relationship between cell temperature and the chosen predictors. Also, the six thermocouples installed at various locations of the PV array revealed variations in the operating temperatures of the modules. The modules on the east side of the array recorded relatively lower temperatures because of the ceiling that had been removed beneath one of the modules on this side of the array, which permitted the free flow of air. Furthermore, I-V measurements conducted on various strings of the array revealed so many steps (hotspots), indicative of module (or cell) mismatch on almost all the cell strings.
- Full Text:
- Date Issued: 2018
- Authors: Buma, Carine Lethem
- Date: 2018
- Subjects: Building-integrated photovoltaic systems Buildings -- Energy conservation Performance -- Evaluation
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/13227 , vital:39623
- Description: The constant increase in the global demand for energy and the current crisis on global warming and climate change has prompted a dying quest for clean, sustainable and reliable sources of energy. Amongst numerous renewable energy technologies, harnessing energy from the sun is the most viable way of guaranteeing a clean and sustainable supply of energy. Also, photovoltaic energy is one of the ways of using energy from the sun, where sunlight is converted to electricity using photovoltaic panels. Furthermore, the integration of photovoltaic modules into buildings is one of the most elegant innovations of this technology, as it plays the dual role of supplying energy to the building as well as protecting the building from outdoor weather conditions. Moreover, operating off the grid offers the possibility of energy access to locations far off from the grid and individuals willing to gain some degree of energy independence. Evaluating the performance of existing off grid and/or building integrated photovoltaic systems is the key to guaranteeing sustainable development and advancement in the technology. Thus, the aim of this work was to evaluate the performance of an off-grid building integrated photovoltaic system that was installed at the Fort Hare Institute of Technology. This entailed performing an in-depth characterisation of the solar resource at this location, evaluating the performance of the modules under outdoor weather conditions and also evaluating the performance of the balance of system (BOS) components. The system was monitored for a period of nine months (between February and October 2017). A data acquisition system was designed for measuring and recording both electrical system parameters and meteorological parameters affecting the performance of the system. These meteorological parameters include; solar irradiance, ambient temperature, cell temperature, relative humidity, wind speed and direction. A detailed characterisation of the solar resource at this location was carried out. It was observed that the solar declination angle varied from -23.5o on the summer solstice to 23.5o on the winter solstice. Also, the solar altitude angle (at solar noon) which is a complementary angle to the zenith angle varied from 33.7o in June to 80.65o in December. During the summer months, longer day lengths were experienced because the sun traversed the sky over a longer time, rising south of east and setting south of west. Whereas, in the winter months, the path length of the sun was shorter, with the sun rising north of east and setting north of west, hence, shorter day lengths. The solar radiation incident on a 25o north facing solar collector was found to be in three components; beam, diffuse and reflected. The beam component was higher in summer whereas the diffuse component was higher in winter due to an increase in the air mass ratio. However, the total daily average radiation was highest in January (7.12 peak sun hours) and least in June (3.04 peak sun hours). Finally, a comparison between the calculated and measured values of solar radiation showed just a 1.1percent difference over the year with disparities being in the individual months.m The influence of outdoor weather conditions on the performance of the system was also evaluated. Operating temperatures were noticed to have a great impact on the output voltage and power of the PV array. Significant correlations existed between various meteorological parameters. Also, a multiple linear regression model was developed to ascertain the dependence of module temperature on solar irradiance, ambient temperature, relative humidity, wind speed and wind direction. The coefficient of determination for the model was 0.928, showing a strong relationship between cell temperature and the chosen predictors. Also, the six thermocouples installed at various locations of the PV array revealed variations in the operating temperatures of the modules. The modules on the east side of the array recorded relatively lower temperatures because of the ceiling that had been removed beneath one of the modules on this side of the array, which permitted the free flow of air. Furthermore, I-V measurements conducted on various strings of the array revealed so many steps (hotspots), indicative of module (or cell) mismatch on almost all the cell strings.
- Full Text:
- Date Issued: 2018
Foreign aid and social development in Burundi
- Authors: Burarame, Yvette
- Date: 2018
- Subjects: Economic assistance -- Burundi , Burundi -- Economic conditions
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/23559 , vital:30580
- Description: This study scrutinized foreign aid and social development in Burundi. It analysed the relationship between the amount of foreign aid received and enrolment in basic education in Burundi, the relationship between the amount of foreign aid and educational equality in Burundi, the relationship between the amount of foreign aid and the teaching and learning process in Burundi and finally explored the problems in basic education that need solutions. This study made use of various related literature on social development, basic education and foreign aid. It mainly scrutinised literature on basic education in Burundi. This study used a case study research design where both qualitative and quantitative approaches were used. A quantitative approach was used to quantify the effectiveness of foreign aid on social development, while a qualitative approach was adopted to descriptively explain the events linking the findings to the objectives of the study. Thirty six respondents from the provincial education administration office were interviewed and observed and document analysis was performed. These were the main instruments for data collection. This study found that despite incoming foreign aid, the gender issues affecting education were not addressed, residents from marginalised areas had not adequately accessed foreign aid and net development assistance in Burundi was affected by politics, preventing a number of areas from benefitting. It also highlights shortages in school learning materials, late disbursement of education funds and civil conflict, among others. This study recommended the incorporation of government ministries and departments in donor-funded projects to reduce stand-alone projects, to emphasise project monitoring and evaluation, to emphasise mutual accountability and to encourage donor support for national educational priorities, to work on joint and coordinated analysis and missions, to address gender disparities and finally, to separate national politics from foreign aid projects and agencies.
- Full Text:
- Date Issued: 2018
- Authors: Burarame, Yvette
- Date: 2018
- Subjects: Economic assistance -- Burundi , Burundi -- Economic conditions
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/23559 , vital:30580
- Description: This study scrutinized foreign aid and social development in Burundi. It analysed the relationship between the amount of foreign aid received and enrolment in basic education in Burundi, the relationship between the amount of foreign aid and educational equality in Burundi, the relationship between the amount of foreign aid and the teaching and learning process in Burundi and finally explored the problems in basic education that need solutions. This study made use of various related literature on social development, basic education and foreign aid. It mainly scrutinised literature on basic education in Burundi. This study used a case study research design where both qualitative and quantitative approaches were used. A quantitative approach was used to quantify the effectiveness of foreign aid on social development, while a qualitative approach was adopted to descriptively explain the events linking the findings to the objectives of the study. Thirty six respondents from the provincial education administration office were interviewed and observed and document analysis was performed. These were the main instruments for data collection. This study found that despite incoming foreign aid, the gender issues affecting education were not addressed, residents from marginalised areas had not adequately accessed foreign aid and net development assistance in Burundi was affected by politics, preventing a number of areas from benefitting. It also highlights shortages in school learning materials, late disbursement of education funds and civil conflict, among others. This study recommended the incorporation of government ministries and departments in donor-funded projects to reduce stand-alone projects, to emphasise project monitoring and evaluation, to emphasise mutual accountability and to encourage donor support for national educational priorities, to work on joint and coordinated analysis and missions, to address gender disparities and finally, to separate national politics from foreign aid projects and agencies.
- Full Text:
- Date Issued: 2018
Synthesis, characterization and application of novel acetals derived from Eucalyptus oil
- Authors: Burger, Kirstin.
- Date: 2018
- Subjects: Plasticizers , Eucalyptus citriodora
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/23548 , vital:30579
- Description: The aim of the project was to develop new bio-plasticizer compounds which could be incorporated into infant plastics. Plasticizers increase flexibility of plastic. These plasticizer compounds were derived from crude natural oils such as Eucalyptus citriodora oil and virgin coconut oil. A reagent which could be synthesized from Eucalyptus citriodora oil was, para-menthane-3,8-diol (PMD) which was present in a 60:40 ratio of cis and trans isomers of the diol. A green procedure to synthesize the diol, where an environmentally friendly catalyst, citric acid was used. Optimal conditions were 7% aqueous citric acid as the catalyst and 12 hour reaction which resulted in a citronellal conversion of 88.4 ± 0.80% and PMD selectivity of 75.4 ± 1.22%. As the diol was present in isomers, it was of interest to separate the cis and trans isomers for characterization purposes and later for subsequent individual isomer acetalization reactions. Yields obtained for the reaction for cis and trans-PMD were 51% and 36%, respectively. The kinetics for PMD synthesis from Eucalyptus citriodora oil was determined as second order with a rate constant of 0.0008hr-1 and Ea of 15.77kJ/mol. The isomers of para-menthane-3,8-diol could be separated from the isomeric mixture by solvent extraction at -78°C with n-heptane. Individual rod-shaped crystals could be isolated with this procedure and was characterized by X-ray crystallography techniques and identified as cis-para-menthane-3,8-diol. The trans-para-menthane-3,8-diol was successfully separated, however adequate crystals were not grown for X-ray crystallography analysis. Another method of isomer separation was investigated for PMD by the formation of a complex where anhydrous copper chloride could only form a novel complex with cis-para-menthane-3,8-diol. The trans isomer remained unreacted in the filtrate. The cis-para-menthane-3,8-diol isomer could be freed from the complex to yield pure cis isomer. Aldehydes could be synthesized from virgin coconut oil with carboxylic acid extraction procedures of the crude oil. Subsequent synthesis reactions from carboxylic acid to form aldehydes were performed and octanal (85% yield), decanal (88% yield), dodecanal (86% yield) and tetradecanal (14% yield) could be successfully synthesized as precursors to the novel acetalization reactions. Eight novel cyclic acetals with a characteristic 1,3-dioxine ring were successfully synthesized. However, diastereoisomers of cis-acetal and trans-acetal were present and required separation for characterization 1H-NMR, 13C-NMR, FT-IR, GC-MS and optical rotation techniques. The eight novel acetals were further characterized according to their physical properties such as there was no data available for these compounds. The following properties were determined: molecular mass, molecular formula, density, viscosity, boiling point, refractive index, enthalpy of vaporization, flash point, UV-VIS compatibility, solubility’s, colour and odour determination. Yields of up to 97% were obtained for these acetal compounds. The synthesis of acetals was optimized with batch reactions and optimum conditions were determined where eight catalysts were screened. These catalysts included: scandium triflate, Zeolite, sulphuric acid, p-toluene-sulfonic acid, Amberlyst 15®, Amberlyst 36®, Amberlite® IRA-120 and formic acid. Optimal conditions were with Amberlyst 15® catalyst, 50 minute reaction time at 65°C reaction temperature. The kinetics of the reaction was determined as zero order with a rate constant of 11.92 hr-1 and Ea of 0.050 kJ/mol. The acetalization reaction was evaluated using a UniQsis FlowSyn continuous flow reactor. One of the eight acetals (hexanal acetal) was used for the optimization study and the remaining acetals were evaluated with the optimum flow conditions. The reaction was improved with the use of continuous flow chemistry techniques by lowering of the optimum batch conditions. Various residence times (3.46-17.30 minutes) and temperature range (25-85°C) were studied to obtain optimum conditions. This process was efficient and low maintenance, which produced high acetal product selectivity of Optimum continuous flow conditions were determined at 55°C and 17.30 minute residence time with the flow rate of 0.1 ml/min. Heterogeneous catalysts such as Amberlyst 15® and Zeolite were screened and Amberlyst 15® determined as most favourable. The effect of Amberlyst 15® catalyst loading (0.5-2 g) was investigated over a temperature range of 25-85°C. Optimum catalyst loading was determined at 1g. The 8 compounds were tested for potential as plasticizers. This included mechanical, thermal, migratory and aesthetic testing. The novel acetals had to be compared to known plasticizers. Therefore, their plasticizer properties were compared to two commercial plasticizers: DBP and Eastman 168. As the compounds were derived from natural resources, they would be classified as bio-plasticizers if they exhibited such properties. Therefore, it was of interest to compare the novel compounds to a known bio-plasticizer: PMD-citronellal acetal. This compound was also present as a diastereoisomers mixture of cis and trans isomers. Therefore, diastereoisomers of the 8 acetals were separated as cis and trans isomers in high yields for plasticizer testing purposes. All 11 compounds (8 novel acetals, PMD-citronellal acetal, DBP and Eastman 168) were formulated in PVC to produce plastic films. As previously stated, isomers were present for the acetal compounds and these individual isomers were formulated into PVC formulations to evaluate if there was an effect of stereochemistry in the plastic films. Studies on this phenomenon were limited and therefore of interest. For isomeric plasticizer testing, 9 acetals (8 novel acetals and PMD-citronellal acetal) were used in the testing. Therefore 18 test compounds were formulated in PVC films for isomer plasticizer testing. The effect of increasing the compound amount in the PVC formulation was investigated in the range of 3-12% (w/w). The following tests were evaluated for all PVC test films: elongation, stress to fracture, glass transition temperature, leaching rate, flexibility, gloss and opacity. To validate the data and observations made, statistical validation models were developed to justify experimental design and trends observed. All novel compounds had plasticizer properties and one acetal compound was concluded as superior to DBP and Eastman 168, within the testing scope of the research. It was observed that higher molecular mass acetal compounds had increased plasticizer properties. Isomers for all acetal compounds were concluded to affect plasticizer properties differently and were highly significant. As the novel acetal compounds could be synthesized from natural crude resources, it was interesting to investigate if the synthesized acetals retained their anti-bacterial properties which the precursor oils possessed. Anti-bacterial testing of isomeric mixtures of C5-C12 acetal was investigated and compared to PMD-citronellal acetal and the two commercial plasticizers: DBP and Eastman 168. As the scope of the research focussed on bio-plasticizers for infant plastic products, test bacterial strains were chosen based on the pathogenic strains which cause diseases in babies. Six strains of bacteria were evaluated. It was of interest to evaluate the potency of the compounds by determining the minimum concentration of the compounds which would be potent enough to inhibit the bacteria. The commercial plasticizers inhibited no bacteria within the scope of the research. The acetals retained their anti-bacterial properties where C12 acetal was superior in 4/6 strains of bacteria and PMD-citronellal acetal was superior in 2/6 strains of bacteria. This research is novel and there are presently no data available on this. It was concluded that 8 new bio-plasticizers were synthesized, optimized and tested, within the scope of this research. These compounds were comparable to industry standards in all tests and possessed anti-bacterial properties which the industrial standards don’t possess.
- Full Text:
- Date Issued: 2018
- Authors: Burger, Kirstin.
- Date: 2018
- Subjects: Plasticizers , Eucalyptus citriodora
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/23548 , vital:30579
- Description: The aim of the project was to develop new bio-plasticizer compounds which could be incorporated into infant plastics. Plasticizers increase flexibility of plastic. These plasticizer compounds were derived from crude natural oils such as Eucalyptus citriodora oil and virgin coconut oil. A reagent which could be synthesized from Eucalyptus citriodora oil was, para-menthane-3,8-diol (PMD) which was present in a 60:40 ratio of cis and trans isomers of the diol. A green procedure to synthesize the diol, where an environmentally friendly catalyst, citric acid was used. Optimal conditions were 7% aqueous citric acid as the catalyst and 12 hour reaction which resulted in a citronellal conversion of 88.4 ± 0.80% and PMD selectivity of 75.4 ± 1.22%. As the diol was present in isomers, it was of interest to separate the cis and trans isomers for characterization purposes and later for subsequent individual isomer acetalization reactions. Yields obtained for the reaction for cis and trans-PMD were 51% and 36%, respectively. The kinetics for PMD synthesis from Eucalyptus citriodora oil was determined as second order with a rate constant of 0.0008hr-1 and Ea of 15.77kJ/mol. The isomers of para-menthane-3,8-diol could be separated from the isomeric mixture by solvent extraction at -78°C with n-heptane. Individual rod-shaped crystals could be isolated with this procedure and was characterized by X-ray crystallography techniques and identified as cis-para-menthane-3,8-diol. The trans-para-menthane-3,8-diol was successfully separated, however adequate crystals were not grown for X-ray crystallography analysis. Another method of isomer separation was investigated for PMD by the formation of a complex where anhydrous copper chloride could only form a novel complex with cis-para-menthane-3,8-diol. The trans isomer remained unreacted in the filtrate. The cis-para-menthane-3,8-diol isomer could be freed from the complex to yield pure cis isomer. Aldehydes could be synthesized from virgin coconut oil with carboxylic acid extraction procedures of the crude oil. Subsequent synthesis reactions from carboxylic acid to form aldehydes were performed and octanal (85% yield), decanal (88% yield), dodecanal (86% yield) and tetradecanal (14% yield) could be successfully synthesized as precursors to the novel acetalization reactions. Eight novel cyclic acetals with a characteristic 1,3-dioxine ring were successfully synthesized. However, diastereoisomers of cis-acetal and trans-acetal were present and required separation for characterization 1H-NMR, 13C-NMR, FT-IR, GC-MS and optical rotation techniques. The eight novel acetals were further characterized according to their physical properties such as there was no data available for these compounds. The following properties were determined: molecular mass, molecular formula, density, viscosity, boiling point, refractive index, enthalpy of vaporization, flash point, UV-VIS compatibility, solubility’s, colour and odour determination. Yields of up to 97% were obtained for these acetal compounds. The synthesis of acetals was optimized with batch reactions and optimum conditions were determined where eight catalysts were screened. These catalysts included: scandium triflate, Zeolite, sulphuric acid, p-toluene-sulfonic acid, Amberlyst 15®, Amberlyst 36®, Amberlite® IRA-120 and formic acid. Optimal conditions were with Amberlyst 15® catalyst, 50 minute reaction time at 65°C reaction temperature. The kinetics of the reaction was determined as zero order with a rate constant of 11.92 hr-1 and Ea of 0.050 kJ/mol. The acetalization reaction was evaluated using a UniQsis FlowSyn continuous flow reactor. One of the eight acetals (hexanal acetal) was used for the optimization study and the remaining acetals were evaluated with the optimum flow conditions. The reaction was improved with the use of continuous flow chemistry techniques by lowering of the optimum batch conditions. Various residence times (3.46-17.30 minutes) and temperature range (25-85°C) were studied to obtain optimum conditions. This process was efficient and low maintenance, which produced high acetal product selectivity of Optimum continuous flow conditions were determined at 55°C and 17.30 minute residence time with the flow rate of 0.1 ml/min. Heterogeneous catalysts such as Amberlyst 15® and Zeolite were screened and Amberlyst 15® determined as most favourable. The effect of Amberlyst 15® catalyst loading (0.5-2 g) was investigated over a temperature range of 25-85°C. Optimum catalyst loading was determined at 1g. The 8 compounds were tested for potential as plasticizers. This included mechanical, thermal, migratory and aesthetic testing. The novel acetals had to be compared to known plasticizers. Therefore, their plasticizer properties were compared to two commercial plasticizers: DBP and Eastman 168. As the compounds were derived from natural resources, they would be classified as bio-plasticizers if they exhibited such properties. Therefore, it was of interest to compare the novel compounds to a known bio-plasticizer: PMD-citronellal acetal. This compound was also present as a diastereoisomers mixture of cis and trans isomers. Therefore, diastereoisomers of the 8 acetals were separated as cis and trans isomers in high yields for plasticizer testing purposes. All 11 compounds (8 novel acetals, PMD-citronellal acetal, DBP and Eastman 168) were formulated in PVC to produce plastic films. As previously stated, isomers were present for the acetal compounds and these individual isomers were formulated into PVC formulations to evaluate if there was an effect of stereochemistry in the plastic films. Studies on this phenomenon were limited and therefore of interest. For isomeric plasticizer testing, 9 acetals (8 novel acetals and PMD-citronellal acetal) were used in the testing. Therefore 18 test compounds were formulated in PVC films for isomer plasticizer testing. The effect of increasing the compound amount in the PVC formulation was investigated in the range of 3-12% (w/w). The following tests were evaluated for all PVC test films: elongation, stress to fracture, glass transition temperature, leaching rate, flexibility, gloss and opacity. To validate the data and observations made, statistical validation models were developed to justify experimental design and trends observed. All novel compounds had plasticizer properties and one acetal compound was concluded as superior to DBP and Eastman 168, within the testing scope of the research. It was observed that higher molecular mass acetal compounds had increased plasticizer properties. Isomers for all acetal compounds were concluded to affect plasticizer properties differently and were highly significant. As the novel acetal compounds could be synthesized from natural crude resources, it was interesting to investigate if the synthesized acetals retained their anti-bacterial properties which the precursor oils possessed. Anti-bacterial testing of isomeric mixtures of C5-C12 acetal was investigated and compared to PMD-citronellal acetal and the two commercial plasticizers: DBP and Eastman 168. As the scope of the research focussed on bio-plasticizers for infant plastic products, test bacterial strains were chosen based on the pathogenic strains which cause diseases in babies. Six strains of bacteria were evaluated. It was of interest to evaluate the potency of the compounds by determining the minimum concentration of the compounds which would be potent enough to inhibit the bacteria. The commercial plasticizers inhibited no bacteria within the scope of the research. The acetals retained their anti-bacterial properties where C12 acetal was superior in 4/6 strains of bacteria and PMD-citronellal acetal was superior in 2/6 strains of bacteria. This research is novel and there are presently no data available on this. It was concluded that 8 new bio-plasticizers were synthesized, optimized and tested, within the scope of this research. These compounds were comparable to industry standards in all tests and possessed anti-bacterial properties which the industrial standards don’t possess.
- Full Text:
- Date Issued: 2018
A mineralogical, geochemical and metallogenic study of unusual Mn/Na/Ba assemblages at the footwall of conglomeratic iron-ore at farm Langverwacht, Northern Cape Province of South Africa
- Authors: Bursey, James Rodney
- Date: 2018
- Subjects: Iron ores -- Geology -- South Africa -- Northern Cape , Conglomerate -- South Africa -- Northern Cape , Petrology -- South Africa -- Northern Cape , Manganese -- South Africa -- Northern Cape , Sodium -- South Africa -- Northern Cape , Barium -- South Africa -- Northern Cape
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/62516 , vital:28201
- Description: The Postmasburg Manganese Field (PMF), located in the Northern Cape province of South Africa, plays host to significant deposits of iron and manganese that have been utilized since their discovery in 1922 by Captain L.T. Shone. Further afield, lies the massive high-grade manganese deposit of the Kalahari Manganese Field (KMF), which drew attention away from the PMF after its discovery. These deposits are not limited to iron and manganese ore, but contain significant assemblages of alkali-rich rocks - which is the focus of this study. The existence of alkali-rich assemblages beneath conglomeratic iron-ore on farm Langwervacht, has come under investigation in this study, and in particular, the enrichment of these rocks in Ba, Na and Mn. Petrographic analysis of the clast-supported conglomerate unit (ore-zone), has uncovered the presence of vugs (up to 8mm across) which contain barite, K-feldspar and fluorapatite. In addition to this, the ore-zone of one of the three boreholes contains late carbonate veins (kutnohorite), which travel along Fe-clast boundaries, and exploit clast-fractures and areas of weakness. Further down, within the ‘enriched-zone’ of alkalis, the mineralogy is more diverse - containing elevated concentrations of Ba, Na and Mn. Seventeen distinct minerals containing these three key elements have been identified - along with one solid-solution series in the form of hollandite-coronadite. The existence of minerals such as natrolite, aegirine, albite, banalsite, barite, serandite, celsian and hollandite-coronadite are indicative of hydrothermal activity having influenced these rocks. Bulk-geochemistry was used to compare the major and trace elements of each borehole and the associated units. Both the trace elements and the REE’s from the ore-zone are enriched by an average of 5-10x relative to the BIF standard used - which immediately suggests an influx of elements. Compared to PAAS (Post Archaean Australian Shales), the ore-zone REE’s are slightly depleted, but more importantly the profiles are very similar to that of the Mapedi shales achieved in previous studies. This result points towards a strong shale influence in the ore-zone protolith. Expectedly, many of the enriched-zone trace elements and REE’s show far greater enrichment than what is observed in the ore-zone. Trace and Rare Earth Element profiles between the ore-zone and the enriched-zone are, however, generally correlative, with profiles reflecting similar enrichments and depletions for a given element - even within different rock units. This suggests that the hydrothermal fluid has moved in a general upward direction, reacting with host-rock units, and relinquishing elements carried in solution - wherever conditions have been favourable for the accommodation of these elements. This study has shed light on the relationship between the ore-zone and the enriched-zone, and results suggest that the process of alkali enrichment is not directly related to the process of upgrading of the iron ores. This is due to the extent of the alkali-enrichment below the ore-zone, as well as enrichment factors in some trace elements being superior to that of Fe2O3 in the ore- zone. Hence, both of these zones have both been affected by a later hydrothermal fluid. The source of the fluid is likely a mature basinal brine, of oxidized, alkaline nature - which leached elements (Ba, K, Na, Pb, Ca) from older rocks, and carried them in solution. On a local-scale, this fluid has exploited areas of weakness in the form of fractures, less consolidated conglomeratic material and crosscutting veins. Manganese and iron has been remobilized on a local scale - producing secondary textures and partitioning into phases such as Mn-rich calcite and serandite. Comparisons to other studies in the PMF and KMF have revealed very similar alkali-rich assemblages, bearing many of the same minerals observed in this study - even within more manganiferous deposits. These findings have led to suggestions of a possible regional-scale hydrothermal overprint, which may have imparted a similar geochemical signal over the entire region - with the assistance of faults and unconformities. Of course, proving this is no mean feat, but current work on the source of barium in barite, using Sr isotopes from samples across the region may shed light on the source of at least one key element of these deposits.
- Full Text:
- Date Issued: 2018
- Authors: Bursey, James Rodney
- Date: 2018
- Subjects: Iron ores -- Geology -- South Africa -- Northern Cape , Conglomerate -- South Africa -- Northern Cape , Petrology -- South Africa -- Northern Cape , Manganese -- South Africa -- Northern Cape , Sodium -- South Africa -- Northern Cape , Barium -- South Africa -- Northern Cape
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/62516 , vital:28201
- Description: The Postmasburg Manganese Field (PMF), located in the Northern Cape province of South Africa, plays host to significant deposits of iron and manganese that have been utilized since their discovery in 1922 by Captain L.T. Shone. Further afield, lies the massive high-grade manganese deposit of the Kalahari Manganese Field (KMF), which drew attention away from the PMF after its discovery. These deposits are not limited to iron and manganese ore, but contain significant assemblages of alkali-rich rocks - which is the focus of this study. The existence of alkali-rich assemblages beneath conglomeratic iron-ore on farm Langwervacht, has come under investigation in this study, and in particular, the enrichment of these rocks in Ba, Na and Mn. Petrographic analysis of the clast-supported conglomerate unit (ore-zone), has uncovered the presence of vugs (up to 8mm across) which contain barite, K-feldspar and fluorapatite. In addition to this, the ore-zone of one of the three boreholes contains late carbonate veins (kutnohorite), which travel along Fe-clast boundaries, and exploit clast-fractures and areas of weakness. Further down, within the ‘enriched-zone’ of alkalis, the mineralogy is more diverse - containing elevated concentrations of Ba, Na and Mn. Seventeen distinct minerals containing these three key elements have been identified - along with one solid-solution series in the form of hollandite-coronadite. The existence of minerals such as natrolite, aegirine, albite, banalsite, barite, serandite, celsian and hollandite-coronadite are indicative of hydrothermal activity having influenced these rocks. Bulk-geochemistry was used to compare the major and trace elements of each borehole and the associated units. Both the trace elements and the REE’s from the ore-zone are enriched by an average of 5-10x relative to the BIF standard used - which immediately suggests an influx of elements. Compared to PAAS (Post Archaean Australian Shales), the ore-zone REE’s are slightly depleted, but more importantly the profiles are very similar to that of the Mapedi shales achieved in previous studies. This result points towards a strong shale influence in the ore-zone protolith. Expectedly, many of the enriched-zone trace elements and REE’s show far greater enrichment than what is observed in the ore-zone. Trace and Rare Earth Element profiles between the ore-zone and the enriched-zone are, however, generally correlative, with profiles reflecting similar enrichments and depletions for a given element - even within different rock units. This suggests that the hydrothermal fluid has moved in a general upward direction, reacting with host-rock units, and relinquishing elements carried in solution - wherever conditions have been favourable for the accommodation of these elements. This study has shed light on the relationship between the ore-zone and the enriched-zone, and results suggest that the process of alkali enrichment is not directly related to the process of upgrading of the iron ores. This is due to the extent of the alkali-enrichment below the ore-zone, as well as enrichment factors in some trace elements being superior to that of Fe2O3 in the ore- zone. Hence, both of these zones have both been affected by a later hydrothermal fluid. The source of the fluid is likely a mature basinal brine, of oxidized, alkaline nature - which leached elements (Ba, K, Na, Pb, Ca) from older rocks, and carried them in solution. On a local-scale, this fluid has exploited areas of weakness in the form of fractures, less consolidated conglomeratic material and crosscutting veins. Manganese and iron has been remobilized on a local scale - producing secondary textures and partitioning into phases such as Mn-rich calcite and serandite. Comparisons to other studies in the PMF and KMF have revealed very similar alkali-rich assemblages, bearing many of the same minerals observed in this study - even within more manganiferous deposits. These findings have led to suggestions of a possible regional-scale hydrothermal overprint, which may have imparted a similar geochemical signal over the entire region - with the assistance of faults and unconformities. Of course, proving this is no mean feat, but current work on the source of barium in barite, using Sr isotopes from samples across the region may shed light on the source of at least one key element of these deposits.
- Full Text:
- Date Issued: 2018
A peaceful revenge: Achieving structural and agential transformation in a South African context using cognitive justice and emancipatory social learning
- Authors: Burt, Jane C , James, Anna
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/392049 , vital:68717 , xlink:href="https://doi.org/10.1080/14767430.2018.1550312"
- Description: This is an account of the emancipatory struggle that faces agents who seek to change the oppressive social structures associated with neo-liberalism. We begin by ‘digging amongst the bones’ of the calls for resistance that have been declared dead or assimilated/co-opted by neoliberal theorists. This leads us to unearth, then utilize, Paulo Freire’s Pedagogy of the Oppressed, Steve Biko’s Black Consciousness and Shiv Visvanathan's ideas; which are examples of Roy Bhaskar’s transformative dialectic. We argue, using examples, that cognitive justice – a concept common to each of our chosen theorists – is vital in enabling emancipatory social learning. By embracing cognitive justice, the agents gained confidence, which led to their increased ability to champion community and non-academic knowledge. It also uncovered structural tensions – attendant in neoliberalism – around privilege. By articulating these tensions, the participants were able to ‘come closer together’. Such processes, initiated by ensuring cognitive justice, are possible steps in achieving universal solidarity; which is likely to be a necessary step along the path of achieving emancipation.
- Full Text:
- Date Issued: 2018
- Authors: Burt, Jane C , James, Anna
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/392049 , vital:68717 , xlink:href="https://doi.org/10.1080/14767430.2018.1550312"
- Description: This is an account of the emancipatory struggle that faces agents who seek to change the oppressive social structures associated with neo-liberalism. We begin by ‘digging amongst the bones’ of the calls for resistance that have been declared dead or assimilated/co-opted by neoliberal theorists. This leads us to unearth, then utilize, Paulo Freire’s Pedagogy of the Oppressed, Steve Biko’s Black Consciousness and Shiv Visvanathan's ideas; which are examples of Roy Bhaskar’s transformative dialectic. We argue, using examples, that cognitive justice – a concept common to each of our chosen theorists – is vital in enabling emancipatory social learning. By embracing cognitive justice, the agents gained confidence, which led to their increased ability to champion community and non-academic knowledge. It also uncovered structural tensions – attendant in neoliberalism – around privilege. By articulating these tensions, the participants were able to ‘come closer together’. Such processes, initiated by ensuring cognitive justice, are possible steps in achieving universal solidarity; which is likely to be a necessary step along the path of achieving emancipation.
- Full Text:
- Date Issued: 2018
Assessment of the Eastern Cape Provincial Public Service Commission in promoting public service ethics
- Authors: Butana, Vulikhaya
- Date: 2018
- Subjects: Public administration -- Moral and ethical aspects Civil service ethics Public administration
- Language: English
- Type: Thesis , Masters , Public Administration
- Identifier: http://hdl.handle.net/10353/10295 , vital:35391
- Description: After the fall of the apartheid government with discriminatory laws and the rise and dawn of democracy in South Africa (SA), the government had to restructure the Public Service (PS). The creation and development of PS legislations and policies to regulate the PS took place. The PSC in 1999 was developed to monitor and steer the operation of the PS. The main objective of this study is to assess the Public Service Commission (PSC) in promoting the professional and ethical environment in the Public Service (PS). The PSC is an independent and impartial body or institution which is mandated by the Republic of South African Constitution of 1996 (Act No.108 of 1996), Public Service Commission Act and the Public Service Act. Chapter ten of the Constitution gives PSC a mandate to ensure that the egalitarian values and principles governing public administration are maintained by government departments, organizations, parastatals and administrations providing the PS, where in this study focus on the promotion of ethics. The methodology used in this study is qualitative research methodology. The study used desktop research where by a data was collected using books, journal articles, academic papers, online information and media reports. The findings of this study highlighted that non-compliance to rules and regulations, lack of policy implementation, limited financial and human resources are still the major problems facing the South African Public Service (SAPS). However, the study recommends that, the PSC must work closely with government departments, promotion of ethics workshops and conferences. In a nutshell, the PSC could improve by developing and regularly reviewing policies, procedures, practices and institutions influencing ethical conduct in the public service.
- Full Text:
- Date Issued: 2018
- Authors: Butana, Vulikhaya
- Date: 2018
- Subjects: Public administration -- Moral and ethical aspects Civil service ethics Public administration
- Language: English
- Type: Thesis , Masters , Public Administration
- Identifier: http://hdl.handle.net/10353/10295 , vital:35391
- Description: After the fall of the apartheid government with discriminatory laws and the rise and dawn of democracy in South Africa (SA), the government had to restructure the Public Service (PS). The creation and development of PS legislations and policies to regulate the PS took place. The PSC in 1999 was developed to monitor and steer the operation of the PS. The main objective of this study is to assess the Public Service Commission (PSC) in promoting the professional and ethical environment in the Public Service (PS). The PSC is an independent and impartial body or institution which is mandated by the Republic of South African Constitution of 1996 (Act No.108 of 1996), Public Service Commission Act and the Public Service Act. Chapter ten of the Constitution gives PSC a mandate to ensure that the egalitarian values and principles governing public administration are maintained by government departments, organizations, parastatals and administrations providing the PS, where in this study focus on the promotion of ethics. The methodology used in this study is qualitative research methodology. The study used desktop research where by a data was collected using books, journal articles, academic papers, online information and media reports. The findings of this study highlighted that non-compliance to rules and regulations, lack of policy implementation, limited financial and human resources are still the major problems facing the South African Public Service (SAPS). However, the study recommends that, the PSC must work closely with government departments, promotion of ethics workshops and conferences. In a nutshell, the PSC could improve by developing and regularly reviewing policies, procedures, practices and institutions influencing ethical conduct in the public service.
- Full Text:
- Date Issued: 2018
Evidence for protandry in Polydactylus quadrifilis in the Kwanza Estuary, Angola, and its implications for local fisheries
- Butler, Edward C, Childs, Amber-Robyn, Winkler, Alexander C, Milner, Marianne V, Potts, Warren M
- Authors: Butler, Edward C , Childs, Amber-Robyn , Winkler, Alexander C , Milner, Marianne V , Potts, Warren M
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124451 , vital:35614 , https://doi.10.1007/s10641-017-0699-6
- Description: A total of 141 Polydactylus quadrifilis were sampled from the Kwanza Estuary in Angola ranging in size from 436 to 1360 mm fork-length (FL). Of these, 124 were male, six intersex and 11 female. Female fish were significantly longer (mm, FL) and heavier (kg) than males and had significantly higher gonadosomatic indices (GSI’s) than those of males and intersex fish. Transitional (intersex) gonads were delimited, with testicular and ovarian regions separated by connective tissue. The first signs of ovarian tissue appeared on the outer ventral surface of the gonad. A second layer of ovarian tissue was first noticeable at either end of the initial ovarian region and developed back towards the centre of the ventral wall to form a luminal space. Early-stage oocytes were commonly found in the outer area of male regions and residual late-stage spermatids and spermatozoa were found in the luminal space of ovarian regions, suggesting a process of sex change from the outside inwards. A loss of male function was noted with increased ovarian prevalence. Based on this evidence it is suggested that P. quadrifilis in the Kwanza Estuary are protandrous. Owing to the reliance of P. quadrifilis on large highly fecund females for egg production, it is likely that they will be sensitive to fishing practices that target larger individuals within the population.
- Full Text:
- Date Issued: 2018
- Authors: Butler, Edward C , Childs, Amber-Robyn , Winkler, Alexander C , Milner, Marianne V , Potts, Warren M
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124451 , vital:35614 , https://doi.10.1007/s10641-017-0699-6
- Description: A total of 141 Polydactylus quadrifilis were sampled from the Kwanza Estuary in Angola ranging in size from 436 to 1360 mm fork-length (FL). Of these, 124 were male, six intersex and 11 female. Female fish were significantly longer (mm, FL) and heavier (kg) than males and had significantly higher gonadosomatic indices (GSI’s) than those of males and intersex fish. Transitional (intersex) gonads were delimited, with testicular and ovarian regions separated by connective tissue. The first signs of ovarian tissue appeared on the outer ventral surface of the gonad. A second layer of ovarian tissue was first noticeable at either end of the initial ovarian region and developed back towards the centre of the ventral wall to form a luminal space. Early-stage oocytes were commonly found in the outer area of male regions and residual late-stage spermatids and spermatozoa were found in the luminal space of ovarian regions, suggesting a process of sex change from the outside inwards. A loss of male function was noted with increased ovarian prevalence. Based on this evidence it is suggested that P. quadrifilis in the Kwanza Estuary are protandrous. Owing to the reliance of P. quadrifilis on large highly fecund females for egg production, it is likely that they will be sensitive to fishing practices that target larger individuals within the population.
- Full Text:
- Date Issued: 2018