Population ecology of Indo-Pacific bottlenose dolphins along the south-east coast of South Africa
- Vargas-Fonseca, O. Alejandra
- Authors: Vargas-Fonseca, O. Alejandra
- Date: 2018
- Subjects: Bottlenose dolphin -- South Africa -- Western Cape , Bottlenose dolphin -- Ecology -- South Africa -- Western Cape Adaptation (Biology) Population biology -- Research
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/36090 , vital:33890
- Description: In this study, the genetic population structure of the Indo-Pacific bottlenose dolphin (Tursiops aduncus) was assessed across the Agulhas and Natal Bioregions of South Africa. At the same time, the abundance, distribution and habitat use of T. aduncus was investigated using boat-based surveys along 145 km of coastline from Goukamma Marine Protected Area (MPA) to Tsitsikamma MPA along the south-east coast of South Africa (Agulhas Bioregion). Tursiops aduncus habitat preferences were assessed based on locations of sightings and recorded behaviour, and compared with those of the sympatric Indian Ocean humpback dolphins (Sousa plumbea). Strong patterns of differentiation between two sub-populations of T. aduncus were identified using double digest Restriction Site Associated DNA sequencing (ddRADseq). Pairwise FST were significant (p < 0.05) between individuals from the Agulhas and Natal Bioregions and yielded values of 0.033 for all the loci. Resource requirements, specialization and differences in habitat use possibly provided sufficient isolation allowing differentiation between sub-populations of the two ecologically distinct bioregions, despite the lack of any prominent boundary to gene flow. The two identified sub-populations should each be managed as a distinct conservation unit. The abundance estimate of T. aduncus for the study area according to an open population model (POPAN) was 2,295 individuals (95% CI: 1,157 - 4,553). Although closed models were considered inappropriate, such a model was applied for the Plettenberg Bay part of the study area in isolation, to allow for comparison with a previous estimate. The comparison showed a 72.3% decrease in abundance between the two periods: from 6,997 (95% CI: 5,230 - 9,492) in 2002 - 2003 to 1,940 (95% CI: 1,448 - 2,600) in 2014 - 2016. The mean group size also declined from 120 (range: 1 - 500) to 26 (range: 1 - 100). The results highlight the importance of assessing abundance changes at other sites to inform the revision of T. aduncus conservation status in South Africa. Tursiops aduncus were encountered throughout the area. The lowest encounter rate was along rocky and exposed shorelines. These areas were, however, associated with relatively larger group sizes and greater likelihood of travelling behaviour, whereas sandy bottomed areas, where encounter rates were highest (e.g. parts of Plettenberg Bay and the Goukamma MPA), were more likely to be associated with other behaviours (e.g. foraging, socialising). There was a relatively low association of encounters with MPAs, possibly due to the fact that two of the three MPAs in the area (Tsitsikamma and Robberg) were characterised by non-preferred habitat, namely rocky shorelines. Comparison with Sousa plumbea showed similarity in habitat preferences between the species, though S. plumbea also showed an affinity for estuarine habitats. Two areas that were highly utilised by both species were located along Goukamma MPA and the north-east section in Plettenberg Bay including the Keurbooms Estuary. The latter is unprotected and a management measure could be to create a controlled-use zone to reduce disturbance to dolphins there.
- Full Text:
- Date Issued: 2018
- Authors: Vargas-Fonseca, O. Alejandra
- Date: 2018
- Subjects: Bottlenose dolphin -- South Africa -- Western Cape , Bottlenose dolphin -- Ecology -- South Africa -- Western Cape Adaptation (Biology) Population biology -- Research
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/36090 , vital:33890
- Description: In this study, the genetic population structure of the Indo-Pacific bottlenose dolphin (Tursiops aduncus) was assessed across the Agulhas and Natal Bioregions of South Africa. At the same time, the abundance, distribution and habitat use of T. aduncus was investigated using boat-based surveys along 145 km of coastline from Goukamma Marine Protected Area (MPA) to Tsitsikamma MPA along the south-east coast of South Africa (Agulhas Bioregion). Tursiops aduncus habitat preferences were assessed based on locations of sightings and recorded behaviour, and compared with those of the sympatric Indian Ocean humpback dolphins (Sousa plumbea). Strong patterns of differentiation between two sub-populations of T. aduncus were identified using double digest Restriction Site Associated DNA sequencing (ddRADseq). Pairwise FST were significant (p < 0.05) between individuals from the Agulhas and Natal Bioregions and yielded values of 0.033 for all the loci. Resource requirements, specialization and differences in habitat use possibly provided sufficient isolation allowing differentiation between sub-populations of the two ecologically distinct bioregions, despite the lack of any prominent boundary to gene flow. The two identified sub-populations should each be managed as a distinct conservation unit. The abundance estimate of T. aduncus for the study area according to an open population model (POPAN) was 2,295 individuals (95% CI: 1,157 - 4,553). Although closed models were considered inappropriate, such a model was applied for the Plettenberg Bay part of the study area in isolation, to allow for comparison with a previous estimate. The comparison showed a 72.3% decrease in abundance between the two periods: from 6,997 (95% CI: 5,230 - 9,492) in 2002 - 2003 to 1,940 (95% CI: 1,448 - 2,600) in 2014 - 2016. The mean group size also declined from 120 (range: 1 - 500) to 26 (range: 1 - 100). The results highlight the importance of assessing abundance changes at other sites to inform the revision of T. aduncus conservation status in South Africa. Tursiops aduncus were encountered throughout the area. The lowest encounter rate was along rocky and exposed shorelines. These areas were, however, associated with relatively larger group sizes and greater likelihood of travelling behaviour, whereas sandy bottomed areas, where encounter rates were highest (e.g. parts of Plettenberg Bay and the Goukamma MPA), were more likely to be associated with other behaviours (e.g. foraging, socialising). There was a relatively low association of encounters with MPAs, possibly due to the fact that two of the three MPAs in the area (Tsitsikamma and Robberg) were characterised by non-preferred habitat, namely rocky shorelines. Comparison with Sousa plumbea showed similarity in habitat preferences between the species, though S. plumbea also showed an affinity for estuarine habitats. Two areas that were highly utilised by both species were located along Goukamma MPA and the north-east section in Plettenberg Bay including the Keurbooms Estuary. The latter is unprotected and a management measure could be to create a controlled-use zone to reduce disturbance to dolphins there.
- Full Text:
- Date Issued: 2018
Possible futures for agricultural financing in sub-Saharan Africa towards 2055
- Authors: Oberholster, Jacobus Hoon
- Date: 2018
- Subjects: Agriculture -- Africa, Sub-Saharan -- Finance , Agricultural industries -- Africa, Sub-Saharan , Agricultural productivity -- Africa, Sub-Saharan
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/23069 , vital:30403
- Description: The research developed four possible future scenarios for agricultural financing in Sub-Saharan Africa towards 2055, namely the “Rising Sun”, “Two Wolves”, “The Left Wing and the Right Wing”, and the “Two Moons” scenarios. The scenarios aim to stimulate new thoughts on an inclusive and broader development approach to agricultural financing, and to identify gaps in the knowledge about a broad range of research issues relating to the level of complexity with regard to the decision-making environment in agricultural financing. The scenarios are developed, according to a strict and predetermined process, which is guided by the Six-Pillars approach of futures studies. A conceptual futures study model for agricultural financing was also developed to guide and clarify the way in which the research on agricultural financing can be integrated into the body of existing futures study theory. The research begins with a comprehensive environmental scan, from which various trends and driving forces emerged. The causal-layered analysis (CLA) method is then used in tandem with other futures-study techniques, such as the futures triangle and emerging issues analyses, to guide the process of knowledge creation about the future of agricultural financing. A real-time Delphi study was also conducted to validate and prioritise the megatrends and driving forces that emerged from the research. Subsequently, the research presents four future scenarios that aim to provide a better understanding of the future of agricultural financing in Sub-Saharan Africa over next 40 years. The research presents agriculture as a multi-dimensional sector that fulfils different roles and functions in especially rural communities in Sub-Saharan Africa, which contribute to the perceived riskiness of agricultural financing. The scenarios illustrate how conditions for agricultural development and agricultural financing can develop and change in the region towards 2055. Furthermore, it provides useful insight into the drivers for change and how to anticipate these changes. The Delphibased scenario research also allowed the aggregation of expert knowledge, which can be used to inform decision-makers in the financial-service sector to test the robustness and appropriateness of existing business models and strategies. The scenarios can also be used as a starting point for financial-service providers and other key stakeholders to identify the future challenges and to maximise the emerging business and development opportunities, as offered by the agricultural sector in Sub-Saharan Africa. The research closes a research gap with regard to scenario development in agricultural financing in Sub-Saharan Africa within the context of the globaldevelopment agenda. The research looks at the future of agricultural financing in Sub-Saharan Africa over the next 40 years from a decision-maker’s point of view; and it provides key insights into especially the rural agricultural financial challenge in the region. A cornerstone of the research is to align policy initiatives and the business strategies of financial service providers with the vision of a broadened view of rural finance and increased financial inclusion in agriculture. The scenarios offer a starting point to develop new and more inclusive agricultural financing strategies that have the ability to speed up income convergence and economic diversification, especially with regard to rural economies in Sub-Saharan Africa that are heavily dependent on agriculture and its related industries. The research also makes a meaningful contribution by introducing a forward-looking, systems-thinking approach to agricultural financing, which is necessary to evaluate the sector’s financing needs within the context of modern food systems that are increasingly being characterised by increased levels of chain co-ordination and value creation. Subsequently, disruptive digital technologies and innovations in agricultural value-chain financing emerged as the most significant driving forces for agricultural financing in Sub-Saharan Africa towards 2055.
- Full Text:
- Date Issued: 2018
- Authors: Oberholster, Jacobus Hoon
- Date: 2018
- Subjects: Agriculture -- Africa, Sub-Saharan -- Finance , Agricultural industries -- Africa, Sub-Saharan , Agricultural productivity -- Africa, Sub-Saharan
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/23069 , vital:30403
- Description: The research developed four possible future scenarios for agricultural financing in Sub-Saharan Africa towards 2055, namely the “Rising Sun”, “Two Wolves”, “The Left Wing and the Right Wing”, and the “Two Moons” scenarios. The scenarios aim to stimulate new thoughts on an inclusive and broader development approach to agricultural financing, and to identify gaps in the knowledge about a broad range of research issues relating to the level of complexity with regard to the decision-making environment in agricultural financing. The scenarios are developed, according to a strict and predetermined process, which is guided by the Six-Pillars approach of futures studies. A conceptual futures study model for agricultural financing was also developed to guide and clarify the way in which the research on agricultural financing can be integrated into the body of existing futures study theory. The research begins with a comprehensive environmental scan, from which various trends and driving forces emerged. The causal-layered analysis (CLA) method is then used in tandem with other futures-study techniques, such as the futures triangle and emerging issues analyses, to guide the process of knowledge creation about the future of agricultural financing. A real-time Delphi study was also conducted to validate and prioritise the megatrends and driving forces that emerged from the research. Subsequently, the research presents four future scenarios that aim to provide a better understanding of the future of agricultural financing in Sub-Saharan Africa over next 40 years. The research presents agriculture as a multi-dimensional sector that fulfils different roles and functions in especially rural communities in Sub-Saharan Africa, which contribute to the perceived riskiness of agricultural financing. The scenarios illustrate how conditions for agricultural development and agricultural financing can develop and change in the region towards 2055. Furthermore, it provides useful insight into the drivers for change and how to anticipate these changes. The Delphibased scenario research also allowed the aggregation of expert knowledge, which can be used to inform decision-makers in the financial-service sector to test the robustness and appropriateness of existing business models and strategies. The scenarios can also be used as a starting point for financial-service providers and other key stakeholders to identify the future challenges and to maximise the emerging business and development opportunities, as offered by the agricultural sector in Sub-Saharan Africa. The research closes a research gap with regard to scenario development in agricultural financing in Sub-Saharan Africa within the context of the globaldevelopment agenda. The research looks at the future of agricultural financing in Sub-Saharan Africa over the next 40 years from a decision-maker’s point of view; and it provides key insights into especially the rural agricultural financial challenge in the region. A cornerstone of the research is to align policy initiatives and the business strategies of financial service providers with the vision of a broadened view of rural finance and increased financial inclusion in agriculture. The scenarios offer a starting point to develop new and more inclusive agricultural financing strategies that have the ability to speed up income convergence and economic diversification, especially with regard to rural economies in Sub-Saharan Africa that are heavily dependent on agriculture and its related industries. The research also makes a meaningful contribution by introducing a forward-looking, systems-thinking approach to agricultural financing, which is necessary to evaluate the sector’s financing needs within the context of modern food systems that are increasingly being characterised by increased levels of chain co-ordination and value creation. Subsequently, disruptive digital technologies and innovations in agricultural value-chain financing emerged as the most significant driving forces for agricultural financing in Sub-Saharan Africa towards 2055.
- Full Text:
- Date Issued: 2018
Potential eco-physiological and phytosociological impacts of fracking on the vegetation of the Karoo, Eastern Cape, South Africa
- Authors: Martin, Kristen
- Date: 2018
- Subjects: Hydraulic fracturing -- Environmental aspects -- South Africa -- Eastern Cape , Germination Plant ecology Plant communities
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/31852 , vital:31853
- Description: Hydraulic fracturing or fracking is a technique that is used to extract gas from low permeable rocks. Large volumes of fluids (typically water combined with chemicals and sand) are injected at high pressure into rock formations to fracture them, allowing the gas to be released. A number of criticisms have come to light regarding the potential environmental impacts of this process. One concern is that there will be contamination of groundwater due to the toxicity of the chemicals used in the fracking process. There have been limited studies on the effects of fracking fluid on vegetation and no studies on South African vegetation specifically. The effects of fracking chemicals on the germination success and photosynthetic efficiency of plants was investigated for species common in areas earmarked for possible future hydraulic fracturing in the Karoo, South Africa. Germination of seeds was unaffected by these fracking fluids at application concentration in most species, but dwarf shrub and grass seeds were found to be sensitive to contamination. A single application treatment of plants with fracking fluid resulted in mortality in 50% of the species with reduced photosynthetic efficiency and growth in some of the surviving species. Long term continual treatment with diluted fracking fluids had an even greater effect on mortality and photosynthetic efficiency than a single high dose. The major vegetation types of the proposed fracking footprint were surveyed and analyses of the species, communities and their physiognomy were used to predict the tolerance of the Karoo vegetation to degradation resulting from shale gas development. An understanding of the sensitivity of vegetation was obtained from impacts of livestock on the vegetation. The results indicated that Grassland communities are least tolerant to degradation, Albany Thicket communities more tolerant and Nama-Karoo communities most tolerant. Escarpment Thickets were shown to be Nama-Karoo rather than Albany Thicket elements, and should be grouped with the former when considering the impacts of fracking.
- Full Text:
- Date Issued: 2018
- Authors: Martin, Kristen
- Date: 2018
- Subjects: Hydraulic fracturing -- Environmental aspects -- South Africa -- Eastern Cape , Germination Plant ecology Plant communities
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/31852 , vital:31853
- Description: Hydraulic fracturing or fracking is a technique that is used to extract gas from low permeable rocks. Large volumes of fluids (typically water combined with chemicals and sand) are injected at high pressure into rock formations to fracture them, allowing the gas to be released. A number of criticisms have come to light regarding the potential environmental impacts of this process. One concern is that there will be contamination of groundwater due to the toxicity of the chemicals used in the fracking process. There have been limited studies on the effects of fracking fluid on vegetation and no studies on South African vegetation specifically. The effects of fracking chemicals on the germination success and photosynthetic efficiency of plants was investigated for species common in areas earmarked for possible future hydraulic fracturing in the Karoo, South Africa. Germination of seeds was unaffected by these fracking fluids at application concentration in most species, but dwarf shrub and grass seeds were found to be sensitive to contamination. A single application treatment of plants with fracking fluid resulted in mortality in 50% of the species with reduced photosynthetic efficiency and growth in some of the surviving species. Long term continual treatment with diluted fracking fluids had an even greater effect on mortality and photosynthetic efficiency than a single high dose. The major vegetation types of the proposed fracking footprint were surveyed and analyses of the species, communities and their physiognomy were used to predict the tolerance of the Karoo vegetation to degradation resulting from shale gas development. An understanding of the sensitivity of vegetation was obtained from impacts of livestock on the vegetation. The results indicated that Grassland communities are least tolerant to degradation, Albany Thicket communities more tolerant and Nama-Karoo communities most tolerant. Escarpment Thickets were shown to be Nama-Karoo rather than Albany Thicket elements, and should be grouped with the former when considering the impacts of fracking.
- Full Text:
- Date Issued: 2018
Prioritisation of spaces and services in on-campus student housing facilities in southern Ghana universities
- Authors: Simpeh, Fredrick
- Date: 2018
- Subjects: Student housing -- Ghana , College students -- Housing -- Ghana Student housing , Facility management -- Ghana Building management -- Ghana
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/35637 , vital:33769
- Description: Student housing facilities (SHFs) are an integral part of universities’ physical facilities. Therefore, the management of SHF should be seen as part of broader university facility management. Moreover, it can be argued that by understanding the requirements of occupants, facility managers would be able to effectively prioritise the spaces and services required in the SHFs. However, studies from many parts of the world, including Ghana, show that users’ requirements and expectations are not duly incorporated into the management process of university building facilities. As a result, users’, in this case students requirements are not well prioritised by facility managers. Thus, the facility departments are unable to adequately provide and deliver SHF spaces and services to meet students’ requirements. With this in mind, this research aimed to develop a prioritisation and a standard SHF frameworks to enhance the provisioning and management of the on-campus SHF spaces and services at southern Ghana universities. The overarching research methodology was subjective. The qualitative method was adopted for the study. The research was conducted within the southern part of Ghana and limited to five universities. A total of ten focus group discussions were carried out in the five universities. Other sources of primary data were interviews and site visit. The study found that washrooms (toilet and bath), sleeping spaces, kitchens, study areas, libraries, sick bays, computer labs, bookshops, drying areas and discussion rooms as well as electricity, water, security, internet, cleaning services, maintenance services, generators, ventilation (fans), health services, library services, electric sockets, study furniture, refuse collection, pest control and fire extinguishers are extremely important spaces and services that students expect to have in a SHF. Furthermore, it was found that only 3 spaces out of the 10 rated as extremely important were rated as basic, whilst 10 out of the 15 services rated as extremely important received a basic priority rating. However, the study also found that some of these extremely important spaces and services such as study areas, computer labs, kitchens and internet were not provided in some SHFs. The study also revealed that students were generally not satisfied with some of the spaces and services that were provided in the SHFs; dissatisfaction was expressed with: the infrequent water supply; the poor condition of washrooms, i.e. bath and toilet facilities; the lack of study areas and also the condition, adequacy and availability of chairs and tables in the study rooms; the slow response of maintenance departments; the poor standard/quality of cleaning and availability of cleaners; the lack of adequate kitchens and the lack of stable internet connectivity. The study has achieved its aim by developing a prioritisation framework as well as an ideal SHF framework to enhance the provision and management of the on-campus SHF spaces and services at southern Ghana universities. It is recommended that SHFs which do not meet average students’ expected standards should be upgraded to meet such standards. The frameworks developed in the study could be used by facility managers or departments as a guide for effective on-campus SHF management.
- Full Text:
- Date Issued: 2018
- Authors: Simpeh, Fredrick
- Date: 2018
- Subjects: Student housing -- Ghana , College students -- Housing -- Ghana Student housing , Facility management -- Ghana Building management -- Ghana
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/35637 , vital:33769
- Description: Student housing facilities (SHFs) are an integral part of universities’ physical facilities. Therefore, the management of SHF should be seen as part of broader university facility management. Moreover, it can be argued that by understanding the requirements of occupants, facility managers would be able to effectively prioritise the spaces and services required in the SHFs. However, studies from many parts of the world, including Ghana, show that users’ requirements and expectations are not duly incorporated into the management process of university building facilities. As a result, users’, in this case students requirements are not well prioritised by facility managers. Thus, the facility departments are unable to adequately provide and deliver SHF spaces and services to meet students’ requirements. With this in mind, this research aimed to develop a prioritisation and a standard SHF frameworks to enhance the provisioning and management of the on-campus SHF spaces and services at southern Ghana universities. The overarching research methodology was subjective. The qualitative method was adopted for the study. The research was conducted within the southern part of Ghana and limited to five universities. A total of ten focus group discussions were carried out in the five universities. Other sources of primary data were interviews and site visit. The study found that washrooms (toilet and bath), sleeping spaces, kitchens, study areas, libraries, sick bays, computer labs, bookshops, drying areas and discussion rooms as well as electricity, water, security, internet, cleaning services, maintenance services, generators, ventilation (fans), health services, library services, electric sockets, study furniture, refuse collection, pest control and fire extinguishers are extremely important spaces and services that students expect to have in a SHF. Furthermore, it was found that only 3 spaces out of the 10 rated as extremely important were rated as basic, whilst 10 out of the 15 services rated as extremely important received a basic priority rating. However, the study also found that some of these extremely important spaces and services such as study areas, computer labs, kitchens and internet were not provided in some SHFs. The study also revealed that students were generally not satisfied with some of the spaces and services that were provided in the SHFs; dissatisfaction was expressed with: the infrequent water supply; the poor condition of washrooms, i.e. bath and toilet facilities; the lack of study areas and also the condition, adequacy and availability of chairs and tables in the study rooms; the slow response of maintenance departments; the poor standard/quality of cleaning and availability of cleaners; the lack of adequate kitchens and the lack of stable internet connectivity. The study has achieved its aim by developing a prioritisation framework as well as an ideal SHF framework to enhance the provision and management of the on-campus SHF spaces and services at southern Ghana universities. It is recommended that SHFs which do not meet average students’ expected standards should be upgraded to meet such standards. The frameworks developed in the study could be used by facility managers or departments as a guide for effective on-campus SHF management.
- Full Text:
- Date Issued: 2018
Productivity and resilience of intertidal resources available to extant human foragers on South Africa’s cape south coast: behavioural implications for early Homo sapiens
- Authors: De Vynck, Jan Carlo
- Date: 2018
- Subjects: Marine invertebrates -- South Africa -- Prehistory , Shellfish -- South Africa -- Prehistory Fishes -- Behavior
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/30172 , vital:30854
- Description: Studies of pre-historic lifestyles can be limited by a lack of preserved material and sites and resource misinterpretation is augmented by the vagueness of pre-historic subsistence lifestyles. The present can inform the past and this study‟s ethnoarchaeological approach, through modern analogues, examines productivity, resilience and temporal and spatial size variation of intertidal invertebrates on the Cape‟s south coast. O‟Connell (1995) defined the mutualistic relationship between ethnography and archaeology thus: “Archaeology‟s ultimate aim is understanding past human behaviour by patterns in the form and distribution of objects made or modified by humans in the past and knowledge of human behaviour and its material consequences in the present. The first provides direct evidence of past behaviour; the second, a basis for interpreting that evidence”. Coastal archaeology, specifically the contribution of coastal resources to pre-historic subsistence, has gained increased global interest (Erlandson, 2001; Erlandson and Rick, 2008; Codding et al., 2014). Apart from the high representation of preserved shell in coastal archaeological sites, interest in intertidal resources has also been sparked by their economic value compared to terrestrial resource options. Intertidal resources offer low-risk protein acquisition whereas terrestrial protein can be dangerous to procure. However, in the past intertidal subsistence was thought to offer low caloric yields or unfavourable cost-to-benefit relationships until Meehan (1982) convincingly demonstrated the potential caloric „profit‟ possible from coastal foraging; the Anbarra women of northern Australia were contributing significantly to the overall caloric requirements of those people. In South Africa, two possible evolutionary behavioural hypotheses arose from the addition of intertidal resources to pre-historic diets. As background, it is important to note that the oldest global evidence for shellfish procurement [164 000 years ago (ka)] is found on the Cape‟s south coast (Jerardino and Marean, 2010) and the evidence is enriched by other sites from around 110 ka (Voight, 1973; Thackeray, 1988; Henshilwood et al., 2001; Langejans et al., 2012). Furthermore, this period coincides with the emergence of cognitively modern Homo sapiens as evidenced in xx the palaeoarchives from many sites in the region (d‟Errico et al., 2005; Marean et al., 2007; Wurz, 2008; Henshilwood et al., 2009; Watts, 2010; d‟Errico et al., 2012). These features have greatly enhanced the significance and importance of this area to understanding human evolution. The two hypotheses are centred around the effect that intertidal resources could have had on the emergence of our unique species. The addition of a nutritionally beneficial resource to cognitive development is seen by some (Broadhurst et al., 2002; Parkington, 2010) to have driven this cognitive evolution, where others suggest that resources which are both productive and dependable create pro-social proclivities that drive cognitive development (Whitaker and Byrd, 2014; Marean, 2014) and facilitate the migration of humans (Fa, 2008; Codding et al., 2014). Both hypotheses argue that resources on the Cape‟s coast must have been productive and had to be a frequent addition to diet to underpin brain development. The increased frequency of coastal resource procurement or coastal adaptation is therefore seen as an attribute of, or requisite for our species. This thesis attempts to shed light on the contribution of intertidal resources to prehistoric ‒ especially Middle Stone Age (MSA) – subsistence economy on the Cape‟s south coast and the possible effect thereof on human behavioural evolution. The first aim was to investigate the spatial productivity (once-off patch caloric profitability in numerous patches) of intertidal resources and the environmental and behavioural variables affecting it. The second aim was to investigate the resilience of caloric profitability (numerous harvests in the same patch) of these resources to sustained human predation. Productivity itself cannot affect human temporal social dynamics if the resource is swiftly depleted within a specific patch after one or a few harvests. Archaeological records that show the body size of shellfish decreasing over time are usually interpreted to indicate intensive exploitation and the depletion of these resources, but there may be other explanations for such patterns. Therefore, the third aim was to compare temporal and spatial variations in the body size of Turbo sarmaticus in the MSA, Later Stone Age (LSA) and the present day, in order to investigate whether such variations result from human exploitation or environmental changes.
- Full Text:
- Date Issued: 2018
- Authors: De Vynck, Jan Carlo
- Date: 2018
- Subjects: Marine invertebrates -- South Africa -- Prehistory , Shellfish -- South Africa -- Prehistory Fishes -- Behavior
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/30172 , vital:30854
- Description: Studies of pre-historic lifestyles can be limited by a lack of preserved material and sites and resource misinterpretation is augmented by the vagueness of pre-historic subsistence lifestyles. The present can inform the past and this study‟s ethnoarchaeological approach, through modern analogues, examines productivity, resilience and temporal and spatial size variation of intertidal invertebrates on the Cape‟s south coast. O‟Connell (1995) defined the mutualistic relationship between ethnography and archaeology thus: “Archaeology‟s ultimate aim is understanding past human behaviour by patterns in the form and distribution of objects made or modified by humans in the past and knowledge of human behaviour and its material consequences in the present. The first provides direct evidence of past behaviour; the second, a basis for interpreting that evidence”. Coastal archaeology, specifically the contribution of coastal resources to pre-historic subsistence, has gained increased global interest (Erlandson, 2001; Erlandson and Rick, 2008; Codding et al., 2014). Apart from the high representation of preserved shell in coastal archaeological sites, interest in intertidal resources has also been sparked by their economic value compared to terrestrial resource options. Intertidal resources offer low-risk protein acquisition whereas terrestrial protein can be dangerous to procure. However, in the past intertidal subsistence was thought to offer low caloric yields or unfavourable cost-to-benefit relationships until Meehan (1982) convincingly demonstrated the potential caloric „profit‟ possible from coastal foraging; the Anbarra women of northern Australia were contributing significantly to the overall caloric requirements of those people. In South Africa, two possible evolutionary behavioural hypotheses arose from the addition of intertidal resources to pre-historic diets. As background, it is important to note that the oldest global evidence for shellfish procurement [164 000 years ago (ka)] is found on the Cape‟s south coast (Jerardino and Marean, 2010) and the evidence is enriched by other sites from around 110 ka (Voight, 1973; Thackeray, 1988; Henshilwood et al., 2001; Langejans et al., 2012). Furthermore, this period coincides with the emergence of cognitively modern Homo sapiens as evidenced in xx the palaeoarchives from many sites in the region (d‟Errico et al., 2005; Marean et al., 2007; Wurz, 2008; Henshilwood et al., 2009; Watts, 2010; d‟Errico et al., 2012). These features have greatly enhanced the significance and importance of this area to understanding human evolution. The two hypotheses are centred around the effect that intertidal resources could have had on the emergence of our unique species. The addition of a nutritionally beneficial resource to cognitive development is seen by some (Broadhurst et al., 2002; Parkington, 2010) to have driven this cognitive evolution, where others suggest that resources which are both productive and dependable create pro-social proclivities that drive cognitive development (Whitaker and Byrd, 2014; Marean, 2014) and facilitate the migration of humans (Fa, 2008; Codding et al., 2014). Both hypotheses argue that resources on the Cape‟s coast must have been productive and had to be a frequent addition to diet to underpin brain development. The increased frequency of coastal resource procurement or coastal adaptation is therefore seen as an attribute of, or requisite for our species. This thesis attempts to shed light on the contribution of intertidal resources to prehistoric ‒ especially Middle Stone Age (MSA) – subsistence economy on the Cape‟s south coast and the possible effect thereof on human behavioural evolution. The first aim was to investigate the spatial productivity (once-off patch caloric profitability in numerous patches) of intertidal resources and the environmental and behavioural variables affecting it. The second aim was to investigate the resilience of caloric profitability (numerous harvests in the same patch) of these resources to sustained human predation. Productivity itself cannot affect human temporal social dynamics if the resource is swiftly depleted within a specific patch after one or a few harvests. Archaeological records that show the body size of shellfish decreasing over time are usually interpreted to indicate intensive exploitation and the depletion of these resources, but there may be other explanations for such patterns. Therefore, the third aim was to compare temporal and spatial variations in the body size of Turbo sarmaticus in the MSA, Later Stone Age (LSA) and the present day, in order to investigate whether such variations result from human exploitation or environmental changes.
- Full Text:
- Date Issued: 2018
Roads and their effects in fynbos of the south-eastern Cape: implications for conservation and management of road verge vegetation
- Authors: Grobler, Barend Adriaan
- Date: 2018
- Subjects: Plant ecology -- South Africa , Ecology -- South Africa Ecology -- Research -- South Africa Conservation biology -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/30105 , vital:30825
- Description: Roads are some of the most conspicuous and pervasive conduits of human influence in modern landscapes. Over the past three decades, there has been a growing interest in the ecological effects of roads. These effects are numerous and generally deleterious, but much of our current knowledge on the matter stems from research conducted in North America, Britain, and Europe, where the focus has been on animal components of ecosystems. There is, however, a need for a plant dimension in road ecology, especially in those areas where plant biodiversity, and threats to this biodiversity, are concentrated. The research presented in this thesis aimed to further our understanding of road effects on the plant component of fynbos ecosystems in the megadiverse Cape Floristic Region (CFR). The exceptional plant diversity of the Cape and the presence of an extensive road network in the region present an ideal system for studying the interactions of roads and plants. Road verges have been emphasised as valuable habitats for plants. However, to assess the viability of road verges as habitats for fynbos plants, we first need to understand how these communities are influenced by the disturbances that exist in these environments. To this end, I investigated fynbos plant communities along roads and showed that road-mediated changes in the soil environment can bring about subtle changes in their composition while key components of the communities persist in road verges. Even though fynbos community patterns remain intact in road verges, the ecological processes that facilitate the persistence of plant species may be disrupted in these environments. As such, I studied the pollination of an ornithophilous plant in road verges and fynbos fragments of a highly transformed landscape. Here, landscape context was an important determining factor in the visitation rate of birds to plants in verges, with those occurring next to transformed land experiencing reduced visitation rates. Furthermore, I studied the pollination and fecundity of a highly threatened entomophilous plant and showed that, while there were no impacts on reproductive output of plants, road effects bolstered the reproductive growth of plants near the road. ii Finally, I implement the road-effect distances identified in the above studies to estimate the proportion of extant fynbos vegetation that may be impacted by roads. While the proportion of vegetation affected by roads is small, a substantial proportion is in close proximity to roads, potentially rendering large areas vulnerable to road-mediated human impacts. I further highlight the fact that several plant species of conservation concern in the Cape are affected by roads, and that many of these constitute a significant proportion of South Africa’s threatened flora. A case study from the N2 national road in the south-eastern Cape, where vegetation in road verges is in a better condition than that of adjacent, demonstrates the potential conservation value of road verges for fynbos vegetation in the region.
- Full Text:
- Date Issued: 2018
- Authors: Grobler, Barend Adriaan
- Date: 2018
- Subjects: Plant ecology -- South Africa , Ecology -- South Africa Ecology -- Research -- South Africa Conservation biology -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/30105 , vital:30825
- Description: Roads are some of the most conspicuous and pervasive conduits of human influence in modern landscapes. Over the past three decades, there has been a growing interest in the ecological effects of roads. These effects are numerous and generally deleterious, but much of our current knowledge on the matter stems from research conducted in North America, Britain, and Europe, where the focus has been on animal components of ecosystems. There is, however, a need for a plant dimension in road ecology, especially in those areas where plant biodiversity, and threats to this biodiversity, are concentrated. The research presented in this thesis aimed to further our understanding of road effects on the plant component of fynbos ecosystems in the megadiverse Cape Floristic Region (CFR). The exceptional plant diversity of the Cape and the presence of an extensive road network in the region present an ideal system for studying the interactions of roads and plants. Road verges have been emphasised as valuable habitats for plants. However, to assess the viability of road verges as habitats for fynbos plants, we first need to understand how these communities are influenced by the disturbances that exist in these environments. To this end, I investigated fynbos plant communities along roads and showed that road-mediated changes in the soil environment can bring about subtle changes in their composition while key components of the communities persist in road verges. Even though fynbos community patterns remain intact in road verges, the ecological processes that facilitate the persistence of plant species may be disrupted in these environments. As such, I studied the pollination of an ornithophilous plant in road verges and fynbos fragments of a highly transformed landscape. Here, landscape context was an important determining factor in the visitation rate of birds to plants in verges, with those occurring next to transformed land experiencing reduced visitation rates. Furthermore, I studied the pollination and fecundity of a highly threatened entomophilous plant and showed that, while there were no impacts on reproductive output of plants, road effects bolstered the reproductive growth of plants near the road. ii Finally, I implement the road-effect distances identified in the above studies to estimate the proportion of extant fynbos vegetation that may be impacted by roads. While the proportion of vegetation affected by roads is small, a substantial proportion is in close proximity to roads, potentially rendering large areas vulnerable to road-mediated human impacts. I further highlight the fact that several plant species of conservation concern in the Cape are affected by roads, and that many of these constitute a significant proportion of South Africa’s threatened flora. A case study from the N2 national road in the south-eastern Cape, where vegetation in road verges is in a better condition than that of adjacent, demonstrates the potential conservation value of road verges for fynbos vegetation in the region.
- Full Text:
- Date Issued: 2018
Rural-urban migration and its impact on rural development in Nigeria
- Authors: Abizu, Odion Stanley
- Date: 2018
- Subjects: Rural development Rural-urban migration -- Nigeria Rural poor
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/13815 , vital:39714
- Description: This thesis focuses on the developmental impact of rural-urban migration in Nigeria. While, recognising the negative impact of rural-urban migration, the study argues that in order to benefit internal migrants as well as rural development, there must be a paradigm shift to focus on how the benefits of migration on development can be achieved. It is proposed that rural-urban migration occurs as a response to economic, education, health, social and environmental factors. The challenges confronting rural areas are urban bias development paradigm pursued by the successive governments resulting in rural underdevelopment that exacerbates the rural urban disparity. And the neglect of agriculture in rural areas resulting from the discovery of oil in Nigeria. The study revealed that flawed policies adopted by successive Nigerian governments led to joblessness, entrenched social inequality and opportunities. One of the outcomes of these short-sighted policies was rural underdevelopment, which accelerated rural-urban migration in Nigeria. However, the study also demonstrates that the income flows from the migrants to the various rural households has contributed to improvement in the living standard of the households. The fragmentary approaches to rural development that is currently the case in Nigeria would not generate the required level of development and growth needed in the rural communities to improve the living standard. Thus, there is need for a policy framework in Nigeria, which would encourage the private sector to play a vital role in contributing their part in the provision of infrastructural facilities in the rural communities. Although this thesis is a case study of the impact of rural-urban migration on rural development in Nigeria, it can serve to appreciate the role migration can play in promoting development both in rural and urban areas in Nigeria and other Saharan Africa countries.
- Full Text:
- Date Issued: 2018
- Authors: Abizu, Odion Stanley
- Date: 2018
- Subjects: Rural development Rural-urban migration -- Nigeria Rural poor
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/13815 , vital:39714
- Description: This thesis focuses on the developmental impact of rural-urban migration in Nigeria. While, recognising the negative impact of rural-urban migration, the study argues that in order to benefit internal migrants as well as rural development, there must be a paradigm shift to focus on how the benefits of migration on development can be achieved. It is proposed that rural-urban migration occurs as a response to economic, education, health, social and environmental factors. The challenges confronting rural areas are urban bias development paradigm pursued by the successive governments resulting in rural underdevelopment that exacerbates the rural urban disparity. And the neglect of agriculture in rural areas resulting from the discovery of oil in Nigeria. The study revealed that flawed policies adopted by successive Nigerian governments led to joblessness, entrenched social inequality and opportunities. One of the outcomes of these short-sighted policies was rural underdevelopment, which accelerated rural-urban migration in Nigeria. However, the study also demonstrates that the income flows from the migrants to the various rural households has contributed to improvement in the living standard of the households. The fragmentary approaches to rural development that is currently the case in Nigeria would not generate the required level of development and growth needed in the rural communities to improve the living standard. Thus, there is need for a policy framework in Nigeria, which would encourage the private sector to play a vital role in contributing their part in the provision of infrastructural facilities in the rural communities. Although this thesis is a case study of the impact of rural-urban migration on rural development in Nigeria, it can serve to appreciate the role migration can play in promoting development both in rural and urban areas in Nigeria and other Saharan Africa countries.
- Full Text:
- Date Issued: 2018
South Africa’s exports to Zimbabwe: a gravity model analysis
- Authors: Muronda, Francis
- Date: 2018
- Subjects: Exports -- South Africa , Foreign trade promotion -- South Africa Foreign trade promotion -- Zimbabwe International finance South Africa -- Economic policy
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/22375 , vital:29964
- Description: This study sets out to explore South Africa’s exports to Zimbabwe as explained by the exchange rates, distance, the two countries’ GDPs and populations. The underlying international trade theories as well as relevant empirical literature are discussed in order to put the study into perspective. Panel data methodology was used to estimate respective gravity models per product category using the log linear specification of the Random effects model. The resultant regression parameters are elasticities. Distance being a proxy to transport costs and the exchange rates retard SA’s exports to Zimbabwe. The GDP of Zimbabwe is found to play a positive and significant role in determining SA’s export flows. The other variables had varying effects from one product category to another. The objectives of the research were threefold: firstly, to apply the gravity model to determine South Africa’s export potential to Zimbabwe; secondly, to determine the gap between the actual and potential flows of exports from South Africa to Zimbabwe and thirdly to apply the speed of convergence tests between the actual and the potential flows of SA’s exports to Zimbabwe. To estimate the gravity models for each product category the study used panel data on South Africa’s exports to SADC countries covering a period of eight years from 2009 when Zimbabwe dollarized to 2016. The parameters obtained were then simulated to provide the point estimates of potential export flows from South Africa to Zimbabwe for each product category. Simple point estimate comparisons between potential flows and the actual flows indicated that most of the product categories portrayed untapped potential; for example, 2017 point estimates showed unutilized potential in 14 product categories. The speed of convergence tests which provide a more efficient measure of expandable opportunities were then carried out between the actual and potential flows for each product category. The results of the speed of convergence tests indicated 10 product categories that presented unutilized potential for South Africa’s exports to Zimbabwe with product category C11 (Textiles and textile articles) at the top of the ranking. Thus the study established that there exists unutilized potential for SA’s exports in Zimbabwe in several product categories despite the prevailing economic hardships that the latter country is facing. Negotiating better bi-lateral trade arrangements specific to product categories; implementation of a one stop border control point and improved international marketing; product quality and disease control strategies are the policy recommendations that the study makes in order for untapped potential to be utilized to realize symbiotic benefits for the two nations.
- Full Text:
- Date Issued: 2018
- Authors: Muronda, Francis
- Date: 2018
- Subjects: Exports -- South Africa , Foreign trade promotion -- South Africa Foreign trade promotion -- Zimbabwe International finance South Africa -- Economic policy
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/22375 , vital:29964
- Description: This study sets out to explore South Africa’s exports to Zimbabwe as explained by the exchange rates, distance, the two countries’ GDPs and populations. The underlying international trade theories as well as relevant empirical literature are discussed in order to put the study into perspective. Panel data methodology was used to estimate respective gravity models per product category using the log linear specification of the Random effects model. The resultant regression parameters are elasticities. Distance being a proxy to transport costs and the exchange rates retard SA’s exports to Zimbabwe. The GDP of Zimbabwe is found to play a positive and significant role in determining SA’s export flows. The other variables had varying effects from one product category to another. The objectives of the research were threefold: firstly, to apply the gravity model to determine South Africa’s export potential to Zimbabwe; secondly, to determine the gap between the actual and potential flows of exports from South Africa to Zimbabwe and thirdly to apply the speed of convergence tests between the actual and the potential flows of SA’s exports to Zimbabwe. To estimate the gravity models for each product category the study used panel data on South Africa’s exports to SADC countries covering a period of eight years from 2009 when Zimbabwe dollarized to 2016. The parameters obtained were then simulated to provide the point estimates of potential export flows from South Africa to Zimbabwe for each product category. Simple point estimate comparisons between potential flows and the actual flows indicated that most of the product categories portrayed untapped potential; for example, 2017 point estimates showed unutilized potential in 14 product categories. The speed of convergence tests which provide a more efficient measure of expandable opportunities were then carried out between the actual and potential flows for each product category. The results of the speed of convergence tests indicated 10 product categories that presented unutilized potential for South Africa’s exports to Zimbabwe with product category C11 (Textiles and textile articles) at the top of the ranking. Thus the study established that there exists unutilized potential for SA’s exports in Zimbabwe in several product categories despite the prevailing economic hardships that the latter country is facing. Negotiating better bi-lateral trade arrangements specific to product categories; implementation of a one stop border control point and improved international marketing; product quality and disease control strategies are the policy recommendations that the study makes in order for untapped potential to be utilized to realize symbiotic benefits for the two nations.
- Full Text:
- Date Issued: 2018
Sustainable competitive tourism in South Africa
- Authors: Ferreira, Daniel Petrus
- Date: 2018
- Subjects: Tourism -- South Africa , Sustainable development Competition -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/22464 , vital:29972
- Description: Tourism is one of the major economic industries in the world and is one of the main income sources for many developing countries such as South Africa (SA). The South African tourism industry contributes approximately R309 billion to the country‘s Gross Domestic Product, and is considered the country‘s fastest growing industry. Although, in comparison to 2016 SA experienced a 2% growth rate of international tourist arrivals in 2014, the increase is considerably lower than the global average of 7%. In 2018, SA also dropped five rankings to number 61, as compared to the previous year according to the Global Competitiveness 2017 to 2018 report. Consequently, SA is not considered a competitive global tourism economy. To increase the country‘s position in the global ranking, it must develop policies and marketing strategies that include both competitive and sustainable aspects. The primary objective of this study is to develop a sustainable- and competitive tourism model for SA. The study investigated and analysed how the independent variables (tourism driving forces) influence sustainable- and competitive tourism (dependent variables). From a comprehensive literature review, a hypothetical model was developed to determine tourism driving forces that might influence sustainable- and competitive tourism. Twenty-two hypotheses were formulated to test the relationships between the eleven tourism driving forces and two dependent variables, namely sustainable- and competitive tourism. This quantitative research approach study sought the perceptions of various tourism stakeholders in SA. A survey was conducted with the aid of a structured web-based questionnaire, distributed via e-mail, and posted on various tourism-specific Facebook pages. A combination of convenience- and snowball sampling was utilised. A final sample of 512 respondents was obtained. The items in the questionnaire were validated by conducting exploratory factor analysis, thereafter the Cronbach‘s alpha values were calculated for each of the valid constructs to confirm inter-item reliability. The results of the Pearson product-moment correlation tests between the various independent and dependent variables revealed mostly moderate to strong correlations. For this reason, multi-collinearity diagnostics testing was conducted prior to multiple regression analysis to confirm that there is no evidence of collinearity between the tourism driving forces, as well as between the dependent variables. The multiple regression analysis reveals three statistically significant relationships between the enabling country conditions (market conditions, technological conditions and tourism policy development) and sustainable tourism. In addition, four statistically significant relationships were found between the destination appeal forces (enablers, enhancers, infrastructure and political conditions) and competitive tourism. The empirical findings further confirmed natural attraction promotional tactics as a destination appeal driving force had a statistically significant relationship with both competitive tourism and sustainability tourism. The inter-relationship between sustainable- and competitive tourism was also confirmed, however, competitive tourism was shown to influence sustainable tourism to a larger extent. Multivariate analysis of variance calculations was used to identify whether the demographic profiles of respondents (classification data) occupy a role in how they view the tourism forces (destination appeal and enabling country conditions) important to create tourism demand in South Africa. A total of 69 statistically significant relationships were found between the classification data and the tourism forces. Post-hoc Tukey tests identified numerous significant means differences within the different classification data categories. The Cohen‘s D analysis revealed 135 practically significant relationships, of which twenty had large practical significance. The five key aspects relevant to increase tourism demand were to have a discrimination-free country regarding race, religion and sexual preference, as well as a safe and stable tourism environment without xenophobic violence. For this reason, the SA government must work actively towards providing a peaceful, safe and discrimination-free tourism environment to attract tourists. Based on the multiple regression results, the marketing of SA‘s natural attractions as a destination appeal factor is essential for competitive tourism to enhance the tourism experience, while it is also imperative for sustainable tourism to increase tourism demand. It is thus suggested that SA Tourism update relevant information regarding the country‘s wildlife and national parks monthly to remain competitive in its quest to towards sustainability. As the destination appeal factors (enablers, enhancers, infrastructure and political conditions) had statistically significant relationships with competitive tourism, these destination appeal factors require consideration. It is therefore recommended that SA should ensure its visa regulations are easily understood, and consider introducing a Tourist Visa On Arrival system to increase the country‘s global tourism competitiveness. In addition, SA should consider creating business- and paleo-tourism niche markets for tourism sustainability. Furthermore, the marketing material must outline the favourable infrastructure available and contain visuals to capture the tourists‘ experiences when selecting SA as a travel destination. The SA government should act responsibly in addressing politically-related unrest through public condemnation of xenophobic violence and showing the severe consequences to those involved in it. Based on the empirical results, enabling country condition factors such as market- and technological conditions, as well as paying attention to the development of the tourism policy, are essential in striving towards sustainable tourism in SA. It is thus suggested that tourism companies promote SA‘s current (2018) favourable exchange rate to potential foreign tourists originating from developed countries. Furthermore, the SA government should adopt globally acceptable online travel application technology to provide travellers with access to reliable and accurate information and enable easy and swift online bookings. This study can be considered one of the first in SA to compile a comprehensive model to confirm empirically which tourism driving forces bring about sustainable- and competitive tourism in the country. This model can now be used by other researchers as a framework for further testing within their respective countries. The study is also the first to identify the major role the demographic profiles of tourists can play in how they view the tourism forces by clearly indicating the differences in thinking of the different demographic groups. The recommendations are tailored for different stakeholder groups such as the government, SA Tourism and travel companies to market SA aptly in their quest towards increasing the country‘s tourism competitiveness and striving towards sustainable tourism.
- Full Text:
- Date Issued: 2018
- Authors: Ferreira, Daniel Petrus
- Date: 2018
- Subjects: Tourism -- South Africa , Sustainable development Competition -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/22464 , vital:29972
- Description: Tourism is one of the major economic industries in the world and is one of the main income sources for many developing countries such as South Africa (SA). The South African tourism industry contributes approximately R309 billion to the country‘s Gross Domestic Product, and is considered the country‘s fastest growing industry. Although, in comparison to 2016 SA experienced a 2% growth rate of international tourist arrivals in 2014, the increase is considerably lower than the global average of 7%. In 2018, SA also dropped five rankings to number 61, as compared to the previous year according to the Global Competitiveness 2017 to 2018 report. Consequently, SA is not considered a competitive global tourism economy. To increase the country‘s position in the global ranking, it must develop policies and marketing strategies that include both competitive and sustainable aspects. The primary objective of this study is to develop a sustainable- and competitive tourism model for SA. The study investigated and analysed how the independent variables (tourism driving forces) influence sustainable- and competitive tourism (dependent variables). From a comprehensive literature review, a hypothetical model was developed to determine tourism driving forces that might influence sustainable- and competitive tourism. Twenty-two hypotheses were formulated to test the relationships between the eleven tourism driving forces and two dependent variables, namely sustainable- and competitive tourism. This quantitative research approach study sought the perceptions of various tourism stakeholders in SA. A survey was conducted with the aid of a structured web-based questionnaire, distributed via e-mail, and posted on various tourism-specific Facebook pages. A combination of convenience- and snowball sampling was utilised. A final sample of 512 respondents was obtained. The items in the questionnaire were validated by conducting exploratory factor analysis, thereafter the Cronbach‘s alpha values were calculated for each of the valid constructs to confirm inter-item reliability. The results of the Pearson product-moment correlation tests between the various independent and dependent variables revealed mostly moderate to strong correlations. For this reason, multi-collinearity diagnostics testing was conducted prior to multiple regression analysis to confirm that there is no evidence of collinearity between the tourism driving forces, as well as between the dependent variables. The multiple regression analysis reveals three statistically significant relationships between the enabling country conditions (market conditions, technological conditions and tourism policy development) and sustainable tourism. In addition, four statistically significant relationships were found between the destination appeal forces (enablers, enhancers, infrastructure and political conditions) and competitive tourism. The empirical findings further confirmed natural attraction promotional tactics as a destination appeal driving force had a statistically significant relationship with both competitive tourism and sustainability tourism. The inter-relationship between sustainable- and competitive tourism was also confirmed, however, competitive tourism was shown to influence sustainable tourism to a larger extent. Multivariate analysis of variance calculations was used to identify whether the demographic profiles of respondents (classification data) occupy a role in how they view the tourism forces (destination appeal and enabling country conditions) important to create tourism demand in South Africa. A total of 69 statistically significant relationships were found between the classification data and the tourism forces. Post-hoc Tukey tests identified numerous significant means differences within the different classification data categories. The Cohen‘s D analysis revealed 135 practically significant relationships, of which twenty had large practical significance. The five key aspects relevant to increase tourism demand were to have a discrimination-free country regarding race, religion and sexual preference, as well as a safe and stable tourism environment without xenophobic violence. For this reason, the SA government must work actively towards providing a peaceful, safe and discrimination-free tourism environment to attract tourists. Based on the multiple regression results, the marketing of SA‘s natural attractions as a destination appeal factor is essential for competitive tourism to enhance the tourism experience, while it is also imperative for sustainable tourism to increase tourism demand. It is thus suggested that SA Tourism update relevant information regarding the country‘s wildlife and national parks monthly to remain competitive in its quest to towards sustainability. As the destination appeal factors (enablers, enhancers, infrastructure and political conditions) had statistically significant relationships with competitive tourism, these destination appeal factors require consideration. It is therefore recommended that SA should ensure its visa regulations are easily understood, and consider introducing a Tourist Visa On Arrival system to increase the country‘s global tourism competitiveness. In addition, SA should consider creating business- and paleo-tourism niche markets for tourism sustainability. Furthermore, the marketing material must outline the favourable infrastructure available and contain visuals to capture the tourists‘ experiences when selecting SA as a travel destination. The SA government should act responsibly in addressing politically-related unrest through public condemnation of xenophobic violence and showing the severe consequences to those involved in it. Based on the empirical results, enabling country condition factors such as market- and technological conditions, as well as paying attention to the development of the tourism policy, are essential in striving towards sustainable tourism in SA. It is thus suggested that tourism companies promote SA‘s current (2018) favourable exchange rate to potential foreign tourists originating from developed countries. Furthermore, the SA government should adopt globally acceptable online travel application technology to provide travellers with access to reliable and accurate information and enable easy and swift online bookings. This study can be considered one of the first in SA to compile a comprehensive model to confirm empirically which tourism driving forces bring about sustainable- and competitive tourism in the country. This model can now be used by other researchers as a framework for further testing within their respective countries. The study is also the first to identify the major role the demographic profiles of tourists can play in how they view the tourism forces by clearly indicating the differences in thinking of the different demographic groups. The recommendations are tailored for different stakeholder groups such as the government, SA Tourism and travel companies to market SA aptly in their quest towards increasing the country‘s tourism competitiveness and striving towards sustainable tourism.
- Full Text:
- Date Issued: 2018
Sustainable livelihood adaptation strategies to climate change in the Nelson Mandela Bay Municipality
- Authors: Nzante, Ekiyie
- Date: 2018
- Subjects: Climatic changes -- Social aspects -- South Africa -- Nelson Mandela Bay Municipality , Sustainable development -- South Africa -- Nelson Mandela Bay Municipality Global warming -- South Africa -- Nelson Mandela Bay Municipality
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/22924 , vital:30146
- Description: The Nelson Mandela Bay Municipality (NMBM) is in the Eastern Cape Province of South Africa and is comprised of Port Elizabeth, Uitenhage, Seaview, Despatch and Blue Horizon Bay. The municipality spans 100 km of coastline and is responsible for 44% of the province’s gross geographical product. In past years the NMBM has experienced problems related to severe climate change, such as storm surges, floods and droughts, which have affected the livelihood of the people. Generally, the NMBM is looked upon as a vulnerable region with regard to climate change because of environmental stressors compounded by recurrent droughts and floods that limit the community’s capacity to cope and adapt effectively. This research explored the existing livelihood strategies set to adapt to the effects of climate change in the municipal area and assessed how effective these strategies are. It proposed sustainable solutions to livelihood problems as climate change consequences were accentuated within the municipal area. The study employed a qualitative research approach whereby data was collected by means of strategic interviews, document analysis, participant observation, focus groups and a study of existing literature. A total of 38 respondents were interviewed using a self-administered questionnaire and 5 focus groups participated in the study. The data was collected within the NMBM over a period of 9 months. The concept of sustainable livelihood (SL) was used to assess the effectiveness of the livelihood strategies implemented in the NMBM to adapt to climate change. The study findings primarily disclosed that certain livelihood strategies exist in the NMBM, such as the hydroponics projects. These strategies are ineffective due to the lack of capital and poor leadership within the municipality. Based on these findings several recommendations were made, for example, the implementation of a household credit system and the creation of a community environmental education programme, amongst others. These will speak not only to a short-term mitigation model of climate change, but would be capable of ensuring a long-term scenario and also create sustainable livelihoods for the people of the NMBM.
- Full Text:
- Date Issued: 2018
- Authors: Nzante, Ekiyie
- Date: 2018
- Subjects: Climatic changes -- Social aspects -- South Africa -- Nelson Mandela Bay Municipality , Sustainable development -- South Africa -- Nelson Mandela Bay Municipality Global warming -- South Africa -- Nelson Mandela Bay Municipality
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/22924 , vital:30146
- Description: The Nelson Mandela Bay Municipality (NMBM) is in the Eastern Cape Province of South Africa and is comprised of Port Elizabeth, Uitenhage, Seaview, Despatch and Blue Horizon Bay. The municipality spans 100 km of coastline and is responsible for 44% of the province’s gross geographical product. In past years the NMBM has experienced problems related to severe climate change, such as storm surges, floods and droughts, which have affected the livelihood of the people. Generally, the NMBM is looked upon as a vulnerable region with regard to climate change because of environmental stressors compounded by recurrent droughts and floods that limit the community’s capacity to cope and adapt effectively. This research explored the existing livelihood strategies set to adapt to the effects of climate change in the municipal area and assessed how effective these strategies are. It proposed sustainable solutions to livelihood problems as climate change consequences were accentuated within the municipal area. The study employed a qualitative research approach whereby data was collected by means of strategic interviews, document analysis, participant observation, focus groups and a study of existing literature. A total of 38 respondents were interviewed using a self-administered questionnaire and 5 focus groups participated in the study. The data was collected within the NMBM over a period of 9 months. The concept of sustainable livelihood (SL) was used to assess the effectiveness of the livelihood strategies implemented in the NMBM to adapt to climate change. The study findings primarily disclosed that certain livelihood strategies exist in the NMBM, such as the hydroponics projects. These strategies are ineffective due to the lack of capital and poor leadership within the municipality. Based on these findings several recommendations were made, for example, the implementation of a household credit system and the creation of a community environmental education programme, amongst others. These will speak not only to a short-term mitigation model of climate change, but would be capable of ensuring a long-term scenario and also create sustainable livelihoods for the people of the NMBM.
- 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
Synthesis, characterization and evaluation of photophysical and electrochemical properties of ruthenium(II) complexes for dye-sensitized solar cells
- Authors: Adjogri, Shadrack John
- Date: 2018
- Subjects: Ruthenium Ruthenium compounds
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/17828 , vital:41363
- Description: Eight series of thirty (30) novel heteroleptic ruthenium(II) complexes were designed, synthesized and spectroscopically characterized, with the following general molecular formulae as [Ru(bdmpmar)(H2dcbpy)(NCS)]+, [Ru(bdmpmar)(vpdiinp)(H2dcbpy)]2,+, [Ru(bdmpmar)(vpbpp)(H2dcbpy)]2+,[Ru(H2dcbpy)2(N^)(NCS)]+, [Ru(H2dcbpy)2(N^)2]2+, [Ru(H2dcbpy)(N^)2(NCS)2], [Ru(H2dcbpy)(N^)(NCS)3]– and [Ru(vptpy)(H2dcbpy)(N^^^)]2+ where bdmpmar is a tridentate ligand of N,N-bis(3, 5-dimethylpyrazol-1-yl-methyl) aromatic organic compound (such aromatic organic compounds(Ar) are anthranilic acid, 4-methoxy-2-nitroaniline, aniline, toluidine, cyclohexylamine and anisidine), vpdiinp represents a monodentate ligand of 11-(4-vinylphenyl)diindeno[1,2-b:2’,1’-e]pyridine, vpbpp represents a monodentate ligand of 4-(4-vinylphenyl)-2.6-bis(phenyl)pyridine and vptpy represents a tridentate ligand of 4’-(4-vinyl)-2,2’:6’,2’’-terpyridine. Meanwhile, N^ represents any of the monodentate ligands of either vpdiinp or vpbpp and (N^^^) represents any of the monodentate ligands either of vpdiinp or vpbpp or NCS as disclosed in series VIII. The complexes were characterized by conductivity measurement, solubility, melting point, UV-Vis, PL, FTIR (ATR), NMR, Cyclic and square wave voltammetry. Nine chelating ligands, comprising of six (6) tripodal chelating ligands, two (2) vinyl monodentate ligands and one (1) vinyl tridentate ligand, were used for the synthesis of ruthenium(II) complexes ATR-FTIR spectra of all the ruthenium(II) complexes measured as solid samples, exhibited fine resolution IR bands in region between 3473-3438 cm-1 of carboxylic group in H2dcbpy. The bands in the range 3040-2950 cm-1 were ascribed to C-H bond stretching for the CH3 groups. The coordination of NCS group in the sphere of ruthenium(II) complexes related to series I, IV, VI VII and one compound of series VIII was investigated by ATR-FTIR spectroscopy. Bands in the range of 2116-2106 cm-1 and 777-770 cm-1 are ascribed to the respective N=C and the C=S bond stretching vibration which confirms the N-coordination of the SCN group. For all the complexes, the stretching vibration of Ru-N bonding was between 466 and 411 cm-1 due to coordination of the nitrogen atoms of the ligands to ruthenium central metal atom. The introduction of the two vinyl monodentate ligands (vpdiinp and vpbpp) in the coordination sphere of [Ru(bdmpmar)(vpdiinp)(H2dcbpy)]2+, [Ru(bdmpmar) (vpbpp)(H2dcbpy)]2+, [Ru(H2dcbpy)2(N^)(NCS)]+, [Ru(H2dcbpy)2(N^)2]2+, [Ru(H2dcbpy)(N^)2(NCS)2], [Ru(H2dcbpy)(N^)(NCS)3]– and [Ru(vptpy)(H2dcbpy)(N^^^)]2+ respectively, all related to series II, III, IV, V, VI, VII and two compounds of series VIII ruthenium(II) complexes, has been studied using the 1H and 13C NMR spectroscopy techniques. The 1H NMR spectra of series II-VII and the two compounds of series VIII of the ruthenium(II) complexes show multiplets in the aromatic region above 6 ppm due to the presence of either vpdiinp or vpbpp ligand, situated in different magnetic environment. However, no splitting pattern was observed in series I and part of VIII complexes possibly due to the absence vinyl monodentate subunits (vpdiinp and vpbpp) in series I and one of compound in series VIII ruthenium(II) complexes show no signals of complex splitting patterns. Carbon-13 NMR spectra data of series I to VIII ruthenium(II) complexes show most resonance signals range in the aromatic region of (δ 116.54-199.63ppm) corresponding to the molecular formulation of ruthenium(II) complexes incorporating 4,4-dicarboxy-2,2’-bipyridine, bdmpmar, vptpy, vpdiinp or vpbpp and NCS ligands respectively, depending on the intrinsic ligand variations. Carbon-13 NMR spectra data of series I, IV, VI VII and one compound in VIII show resonance peaks within the range 130-135 ppm are ascribed to NCS ligand confirming the presence of N-coordinated thiocyanate. Cyclic voltammograms of series I-IV and VI-VIII complexes display ruthenium-based oxidative peaks and the pyridines ligand-based reductive peaks. The redox behavior of complexes 4-12, 14-16, 18-20, 24-26 and 30 is dominated by the Ru(II)/R(III) redox couple in region (E1/2 between 0.53 and 1.18) and the pyridines ligand-based redox couples in the region between (E1/2 between −0.25 and −1.45). The photophysical property studies of the Ru(II) complexes are determined through the acquisitions of the absorption spectra, which tends to have profound effect on the short circuit current of DSSC. The absorption maxima were tuned by the introduction and variation of six (6) tripodal chelating ligands, two (2) vinyl monodentate ligands and one (1) vinyl tridentate ligand. From the studies, the results show that series IV, V, VI, VII and VIII complexes of molecular formula [Ru(H2dcbpy)2(N^)(NCS)]2+, [Ru(H2dcbpy)2(N^)2]2+, [Ru(H2dcbpy)(N^)2(NCS)2]2+, [Ru(H2dcbpy)(N^)(NCS)3]2+ and [Ru(vptpy)(H2dcbpy)(N^^^)]2+ respectively, have higher and multiple local absorption maxima near-IR region than the complexes of series I, II and III of molecular [Ru(bdmpmar)(H2dcbpy)(NCS)]2,+, [Ru(bdmpmar)(vpdiinp)(H2dcbpy)]2,+, [Ru(bdmpmar)(vpbpp)(H2dcbpy)]2,+respectively.
- Full Text:
- Date Issued: 2018
- Authors: Adjogri, Shadrack John
- Date: 2018
- Subjects: Ruthenium Ruthenium compounds
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/17828 , vital:41363
- Description: Eight series of thirty (30) novel heteroleptic ruthenium(II) complexes were designed, synthesized and spectroscopically characterized, with the following general molecular formulae as [Ru(bdmpmar)(H2dcbpy)(NCS)]+, [Ru(bdmpmar)(vpdiinp)(H2dcbpy)]2,+, [Ru(bdmpmar)(vpbpp)(H2dcbpy)]2+,[Ru(H2dcbpy)2(N^)(NCS)]+, [Ru(H2dcbpy)2(N^)2]2+, [Ru(H2dcbpy)(N^)2(NCS)2], [Ru(H2dcbpy)(N^)(NCS)3]– and [Ru(vptpy)(H2dcbpy)(N^^^)]2+ where bdmpmar is a tridentate ligand of N,N-bis(3, 5-dimethylpyrazol-1-yl-methyl) aromatic organic compound (such aromatic organic compounds(Ar) are anthranilic acid, 4-methoxy-2-nitroaniline, aniline, toluidine, cyclohexylamine and anisidine), vpdiinp represents a monodentate ligand of 11-(4-vinylphenyl)diindeno[1,2-b:2’,1’-e]pyridine, vpbpp represents a monodentate ligand of 4-(4-vinylphenyl)-2.6-bis(phenyl)pyridine and vptpy represents a tridentate ligand of 4’-(4-vinyl)-2,2’:6’,2’’-terpyridine. Meanwhile, N^ represents any of the monodentate ligands of either vpdiinp or vpbpp and (N^^^) represents any of the monodentate ligands either of vpdiinp or vpbpp or NCS as disclosed in series VIII. The complexes were characterized by conductivity measurement, solubility, melting point, UV-Vis, PL, FTIR (ATR), NMR, Cyclic and square wave voltammetry. Nine chelating ligands, comprising of six (6) tripodal chelating ligands, two (2) vinyl monodentate ligands and one (1) vinyl tridentate ligand, were used for the synthesis of ruthenium(II) complexes ATR-FTIR spectra of all the ruthenium(II) complexes measured as solid samples, exhibited fine resolution IR bands in region between 3473-3438 cm-1 of carboxylic group in H2dcbpy. The bands in the range 3040-2950 cm-1 were ascribed to C-H bond stretching for the CH3 groups. The coordination of NCS group in the sphere of ruthenium(II) complexes related to series I, IV, VI VII and one compound of series VIII was investigated by ATR-FTIR spectroscopy. Bands in the range of 2116-2106 cm-1 and 777-770 cm-1 are ascribed to the respective N=C and the C=S bond stretching vibration which confirms the N-coordination of the SCN group. For all the complexes, the stretching vibration of Ru-N bonding was between 466 and 411 cm-1 due to coordination of the nitrogen atoms of the ligands to ruthenium central metal atom. The introduction of the two vinyl monodentate ligands (vpdiinp and vpbpp) in the coordination sphere of [Ru(bdmpmar)(vpdiinp)(H2dcbpy)]2+, [Ru(bdmpmar) (vpbpp)(H2dcbpy)]2+, [Ru(H2dcbpy)2(N^)(NCS)]+, [Ru(H2dcbpy)2(N^)2]2+, [Ru(H2dcbpy)(N^)2(NCS)2], [Ru(H2dcbpy)(N^)(NCS)3]– and [Ru(vptpy)(H2dcbpy)(N^^^)]2+ respectively, all related to series II, III, IV, V, VI, VII and two compounds of series VIII ruthenium(II) complexes, has been studied using the 1H and 13C NMR spectroscopy techniques. The 1H NMR spectra of series II-VII and the two compounds of series VIII of the ruthenium(II) complexes show multiplets in the aromatic region above 6 ppm due to the presence of either vpdiinp or vpbpp ligand, situated in different magnetic environment. However, no splitting pattern was observed in series I and part of VIII complexes possibly due to the absence vinyl monodentate subunits (vpdiinp and vpbpp) in series I and one of compound in series VIII ruthenium(II) complexes show no signals of complex splitting patterns. Carbon-13 NMR spectra data of series I to VIII ruthenium(II) complexes show most resonance signals range in the aromatic region of (δ 116.54-199.63ppm) corresponding to the molecular formulation of ruthenium(II) complexes incorporating 4,4-dicarboxy-2,2’-bipyridine, bdmpmar, vptpy, vpdiinp or vpbpp and NCS ligands respectively, depending on the intrinsic ligand variations. Carbon-13 NMR spectra data of series I, IV, VI VII and one compound in VIII show resonance peaks within the range 130-135 ppm are ascribed to NCS ligand confirming the presence of N-coordinated thiocyanate. Cyclic voltammograms of series I-IV and VI-VIII complexes display ruthenium-based oxidative peaks and the pyridines ligand-based reductive peaks. The redox behavior of complexes 4-12, 14-16, 18-20, 24-26 and 30 is dominated by the Ru(II)/R(III) redox couple in region (E1/2 between 0.53 and 1.18) and the pyridines ligand-based redox couples in the region between (E1/2 between −0.25 and −1.45). The photophysical property studies of the Ru(II) complexes are determined through the acquisitions of the absorption spectra, which tends to have profound effect on the short circuit current of DSSC. The absorption maxima were tuned by the introduction and variation of six (6) tripodal chelating ligands, two (2) vinyl monodentate ligands and one (1) vinyl tridentate ligand. From the studies, the results show that series IV, V, VI, VII and VIII complexes of molecular formula [Ru(H2dcbpy)2(N^)(NCS)]2+, [Ru(H2dcbpy)2(N^)2]2+, [Ru(H2dcbpy)(N^)2(NCS)2]2+, [Ru(H2dcbpy)(N^)(NCS)3]2+ and [Ru(vptpy)(H2dcbpy)(N^^^)]2+ respectively, have higher and multiple local absorption maxima near-IR region than the complexes of series I, II and III of molecular [Ru(bdmpmar)(H2dcbpy)(NCS)]2,+, [Ru(bdmpmar)(vpdiinp)(H2dcbpy)]2,+, [Ru(bdmpmar)(vpbpp)(H2dcbpy)]2,+respectively.
- Full Text:
- Date Issued: 2018
Tanzania’s mediation process in the conflict between the Hutu and Tutsi parties in Burundi 1993 -2005: a mediation perspective
- Authors: Kanuwa, Juma Mabasa
- Date: 2018
- Subjects: Mediation -- Tanzania , Mediation -- Burundi Conflict management -- Tanzania Conflict management -- Burundi Hutu (African people) -- Burundi
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/30671 , vital:31011
- Description: The goal of this research was to examine Tanzania’s mediation process in the conflict between the Hutu and Tutsi parties in Burundi from 1993 to 2005, from a mediation theoretical perspective. To achieve this, a critical paradigm was used as the way to view the mediation process in the Great Lakes Region. The study also aimed at attaining a grounded theoretical understanding of the topic under study, including an in depth understanding of Tanzania’s history in conflict resolution, the historical causes of Burundi’s deep-rooted social conflict, theories of conflict and conflict resolution, third party intervention and mediation theories and perspectives. This study is underpinned by Bercovitch’s Mediation Framework and its quest for problem-solving. It is a qualitative study that used documentary review, individual interviews and focus group interviews as data-gathering instruments. The selection of the study sample was carried out according to a purposive approach. The data was collected from minutes of meetings, verbatim reports, letters, journals, books, individual interviews and focus group interviews. The findings of the study culminated in three major findings which are: the finding of the first research question on Tanzania’s mediation process that Tanzania’s motivation for mediating stemmed from its traditional foreign policy, the effectiveness of the intervention stemmed from its sound understanding of the root causes of the conflict between the Hutu and Tutsi and because the parties retained ownership of the mediation process. Other success factors were due to the third-party collaboration with International Organizations, and the use of a transformative mediation approach. The finding in respect of the second research question comparing Tanzania’s mediation process with the mediation perspectives of Bercovitch and Burton was that there were similarities which were based on their assumptions in respect of social conflict, responses to conflict, the objectives of mediation, the role of mediator, the mediation action itself, the focus of mediator, timing of mediation and the success of mediation. With regards to the third question, the findings proposed improvements in respect of vii professionalism of the mediator, a change of mediation culture and attitude, the personality of mediators, diplomatic support for mediation and the institutionalisation and consolidation of conflict management. The study concluded by proposing a Professional Integration Mediation Practice (PIMP) framework. The PIMP framework was developed, based on the findings of the study, and anticipates the provision of guidance to mediators and facilitators on the use of a more Professional Integration Mediation Practice approach to facilitate a positive mediation process. The PIMP framework further provides a range of advantages in the process of conflict resolution with respect to deep–rooted social conflict. However, there is a need for agreement of international organizations on the use of professional mediators and facilitators in a mediation process. The PIMP framework can go a long way to effectively resolve deep–rooted social conflicts with the appropriate support of international organisations, and the international community as a whole.
- Full Text:
- Date Issued: 2018
- Authors: Kanuwa, Juma Mabasa
- Date: 2018
- Subjects: Mediation -- Tanzania , Mediation -- Burundi Conflict management -- Tanzania Conflict management -- Burundi Hutu (African people) -- Burundi
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/30671 , vital:31011
- Description: The goal of this research was to examine Tanzania’s mediation process in the conflict between the Hutu and Tutsi parties in Burundi from 1993 to 2005, from a mediation theoretical perspective. To achieve this, a critical paradigm was used as the way to view the mediation process in the Great Lakes Region. The study also aimed at attaining a grounded theoretical understanding of the topic under study, including an in depth understanding of Tanzania’s history in conflict resolution, the historical causes of Burundi’s deep-rooted social conflict, theories of conflict and conflict resolution, third party intervention and mediation theories and perspectives. This study is underpinned by Bercovitch’s Mediation Framework and its quest for problem-solving. It is a qualitative study that used documentary review, individual interviews and focus group interviews as data-gathering instruments. The selection of the study sample was carried out according to a purposive approach. The data was collected from minutes of meetings, verbatim reports, letters, journals, books, individual interviews and focus group interviews. The findings of the study culminated in three major findings which are: the finding of the first research question on Tanzania’s mediation process that Tanzania’s motivation for mediating stemmed from its traditional foreign policy, the effectiveness of the intervention stemmed from its sound understanding of the root causes of the conflict between the Hutu and Tutsi and because the parties retained ownership of the mediation process. Other success factors were due to the third-party collaboration with International Organizations, and the use of a transformative mediation approach. The finding in respect of the second research question comparing Tanzania’s mediation process with the mediation perspectives of Bercovitch and Burton was that there were similarities which were based on their assumptions in respect of social conflict, responses to conflict, the objectives of mediation, the role of mediator, the mediation action itself, the focus of mediator, timing of mediation and the success of mediation. With regards to the third question, the findings proposed improvements in respect of vii professionalism of the mediator, a change of mediation culture and attitude, the personality of mediators, diplomatic support for mediation and the institutionalisation and consolidation of conflict management. The study concluded by proposing a Professional Integration Mediation Practice (PIMP) framework. The PIMP framework was developed, based on the findings of the study, and anticipates the provision of guidance to mediators and facilitators on the use of a more Professional Integration Mediation Practice approach to facilitate a positive mediation process. The PIMP framework further provides a range of advantages in the process of conflict resolution with respect to deep–rooted social conflict. However, there is a need for agreement of international organizations on the use of professional mediators and facilitators in a mediation process. The PIMP framework can go a long way to effectively resolve deep–rooted social conflicts with the appropriate support of international organisations, and the international community as a whole.
- Full Text:
- Date Issued: 2018
The adoption of green building in South Africa
- Authors: Simpeh, Eric Kwame
- Date: 2018
- Subjects: Ecological houses -- Design and construction -- South Africa , Sustainable buildings -- Design and construction -- South Africa Sustainable construction -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/35653 , vital:33771
- Description: In South Africa there is pressure to deliver green building due to environmental issues such as climate changes, the energy crisis, as well as persistent water shortages. Although awareness and promotional effort have increased drastically concerning the adoption of green buildings, the South African design and construction industry is still lagging due to the conservativeness and slow rate of change in the construction industry. While enablers / facilitators have been recognised as opportunities to advance green building development, the South African built environment has not extensively explored the various possibilities to initiate enablers / facilitating conditions to enhance the adoption of green building. This study therefore investigates the critical factors impeding the adoption of green building and to explore the economic and non-economic facilitators / enablers regarded as the most important to stimulate stakeholders’ behavioural intentions to adopt green building. After an extensive review of literature with respect to barriers and factors that engender green building adoption, coupled with theoretical arguments relating change agents to construction innovation and sustainability theory, an exhaustive mixed-mode research approach was adopted. The sampling frame for the study was limited to four provinces, namely the Eastern Cape, Gauteng, Kwazulu–Natal, and Western Cape, given that 99% of the green building accredited professionals registered with the GBCSA are from these four provinces. The quantitative data was analysed using descriptive and inferential statistics, namely paired sample test, ANOVA test, Factor Analysis (FA), and logistic regression analysis (LRA). The qualitative data obtained across individual cases by means of a semi-structured interview was analysed using content analysis. In total, 106 professionals participated in the survey, and three respondents indicated their willingness and availability to be interviewed, hence three case studies were conducted. The results emanating from the study, inter-alia, indicate that the factors constraining the adoption of green building are categorised as: lack of information and incentives; inadequate skilled professionals; behavioural barriers; regulatory and steering factors, and the cost of green building. The results also indicate that green building consultants and environmental groups are classified as ‘innovators’, whilst architects are ‘early adopters’. However, government; municipalities, and general contractors are characterised as ‘late majority’. It was also evident from the empirical findings that the key attributes of adopters that encourage the adoption of green building were classified as: qualities of consultant team and contractor, and developers / clients’ experience. The perceived benefits of green buildings emanating from the findings were categorised as socio-economic, financial, and health and community benefits. The enablers that engender the adoption of green building were also categorised as: extended knowledge base and technical capacity; research and training of professionals; green lending incentives; progressive green building policy; economic incentives, and reward scheme and technical assistance. Two models have been developed using logistic regression model (LRM), model one (1) examined the predictable effect of economic and non-economic factors on the intention to adopt green building, whereas model two (2) examined the likelihood of the extent of green building adoption. The LRM results revealed five predictors and two control variables made a unique statistically significant contribution to model 1. The strongest predictor to enhance the intention to adopt green building was financial benefit (FB), recording an odds ratio of 9.1, which indicates that the likelihood to adopt is approximately 9.1 times more if financial benefits is evident. With respect to Model two (2), the LRM results showed that only two of the independent variables and three control variables contributed significantly to the model. The strongest predictor that determines the extent of adoption of green building was research and training of professionals (RTP), with odd ratio equal to 2.9. In effect, to engender the adoption of green building within the South African built environment, there is the need for an integrated and holistic approach forecasting on the importance of economic and non-economic enablers / facilitators in enhancing decision to adopt green building.
- Full Text:
- Date Issued: 2018
- Authors: Simpeh, Eric Kwame
- Date: 2018
- Subjects: Ecological houses -- Design and construction -- South Africa , Sustainable buildings -- Design and construction -- South Africa Sustainable construction -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/35653 , vital:33771
- Description: In South Africa there is pressure to deliver green building due to environmental issues such as climate changes, the energy crisis, as well as persistent water shortages. Although awareness and promotional effort have increased drastically concerning the adoption of green buildings, the South African design and construction industry is still lagging due to the conservativeness and slow rate of change in the construction industry. While enablers / facilitators have been recognised as opportunities to advance green building development, the South African built environment has not extensively explored the various possibilities to initiate enablers / facilitating conditions to enhance the adoption of green building. This study therefore investigates the critical factors impeding the adoption of green building and to explore the economic and non-economic facilitators / enablers regarded as the most important to stimulate stakeholders’ behavioural intentions to adopt green building. After an extensive review of literature with respect to barriers and factors that engender green building adoption, coupled with theoretical arguments relating change agents to construction innovation and sustainability theory, an exhaustive mixed-mode research approach was adopted. The sampling frame for the study was limited to four provinces, namely the Eastern Cape, Gauteng, Kwazulu–Natal, and Western Cape, given that 99% of the green building accredited professionals registered with the GBCSA are from these four provinces. The quantitative data was analysed using descriptive and inferential statistics, namely paired sample test, ANOVA test, Factor Analysis (FA), and logistic regression analysis (LRA). The qualitative data obtained across individual cases by means of a semi-structured interview was analysed using content analysis. In total, 106 professionals participated in the survey, and three respondents indicated their willingness and availability to be interviewed, hence three case studies were conducted. The results emanating from the study, inter-alia, indicate that the factors constraining the adoption of green building are categorised as: lack of information and incentives; inadequate skilled professionals; behavioural barriers; regulatory and steering factors, and the cost of green building. The results also indicate that green building consultants and environmental groups are classified as ‘innovators’, whilst architects are ‘early adopters’. However, government; municipalities, and general contractors are characterised as ‘late majority’. It was also evident from the empirical findings that the key attributes of adopters that encourage the adoption of green building were classified as: qualities of consultant team and contractor, and developers / clients’ experience. The perceived benefits of green buildings emanating from the findings were categorised as socio-economic, financial, and health and community benefits. The enablers that engender the adoption of green building were also categorised as: extended knowledge base and technical capacity; research and training of professionals; green lending incentives; progressive green building policy; economic incentives, and reward scheme and technical assistance. Two models have been developed using logistic regression model (LRM), model one (1) examined the predictable effect of economic and non-economic factors on the intention to adopt green building, whereas model two (2) examined the likelihood of the extent of green building adoption. The LRM results revealed five predictors and two control variables made a unique statistically significant contribution to model 1. The strongest predictor to enhance the intention to adopt green building was financial benefit (FB), recording an odds ratio of 9.1, which indicates that the likelihood to adopt is approximately 9.1 times more if financial benefits is evident. With respect to Model two (2), the LRM results showed that only two of the independent variables and three control variables contributed significantly to the model. The strongest predictor that determines the extent of adoption of green building was research and training of professionals (RTP), with odd ratio equal to 2.9. In effect, to engender the adoption of green building within the South African built environment, there is the need for an integrated and holistic approach forecasting on the importance of economic and non-economic enablers / facilitators in enhancing decision to adopt green building.
- Full Text:
- Date Issued: 2018
The classification of fuzzy groups of finite cyclic groups Zpn Zqm Zr and Zp1 Zp2 Zpn for distinct prime numbers p; q; r; p1; p2; ; pn and n;m 2 Z+
- Authors: Munywoki, Michael Mbindyo
- Date: 2018
- Subjects: Fuzzy sets Finite groups
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/17817 , vital:41295
- Description: Let G be the cyclic group Zpn _ Zqm _ Zr where p; q; r are distinct primes and n;m 2 Z+. Using the criss-cut method by Murali and Makamba, we determine in general the number of distinct fuzzy subgroups of G. This is achieved by using the maximal chains of subgroups of the respective groups, and the equivalence relation given in their research papers. For cases of m, the number of fuzzy subgroups is _rst given, from which the general pattern for G is achieved. Murali and Makamba discussed the number of fuzzy subgroups of Zpn _ Zqm using the cross-cut method. A brief revisit of the group Zpn _Zqm is done using the criss-cut method. The formulae for _nding the number of distinct fuzzy subgroups in each of the cases is given and proofs provided. Furthermore, we classify the fuzzy subgroups of the group Zp1_Zp2__ _ __Zpn for p1; p2; _ _ _ ; pn distinct primes and n 2 Z+ using the criss-cut method. An algorithm for counting the distinct fuzzy subgroups of this group is developed.
- Full Text:
- Date Issued: 2018
- Authors: Munywoki, Michael Mbindyo
- Date: 2018
- Subjects: Fuzzy sets Finite groups
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/17817 , vital:41295
- Description: Let G be the cyclic group Zpn _ Zqm _ Zr where p; q; r are distinct primes and n;m 2 Z+. Using the criss-cut method by Murali and Makamba, we determine in general the number of distinct fuzzy subgroups of G. This is achieved by using the maximal chains of subgroups of the respective groups, and the equivalence relation given in their research papers. For cases of m, the number of fuzzy subgroups is _rst given, from which the general pattern for G is achieved. Murali and Makamba discussed the number of fuzzy subgroups of Zpn _ Zqm using the cross-cut method. A brief revisit of the group Zpn _Zqm is done using the criss-cut method. The formulae for _nding the number of distinct fuzzy subgroups in each of the cases is given and proofs provided. Furthermore, we classify the fuzzy subgroups of the group Zp1_Zp2__ _ __Zpn for p1; p2; _ _ _ ; pn distinct primes and n 2 Z+ using the criss-cut method. An algorithm for counting the distinct fuzzy subgroups of this group is developed.
- Full Text:
- Date Issued: 2018
The economic and ecological trade-offs of wetland conversion for development projects: the case of the Kampala–Mukono corridor
- Authors: Wasswa, Hannington
- Date: 2018
- Subjects: Wetland ecology -- Uganda -- Kampala , Wetlands -- Uganda -- Kampala Wetland management -- Uganda -- Kampala Hydrogeology
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/36409 , vital:33939
- Description: Wetland diminution for development projects (DPs) in the Kampala–Mukono Corridor (KMC) continues to pose threats to the socio-economic and ecological benefits of wetlands because decision-makers and wetland users at various levels often have insufficient knowledge of these benefits. This situation has resulted in unsustainable development decisions that accord little weight to wetlands and have allocated many of them to DPs. In order to inform decision making for optimal development in the KMC, the present study analysed the spatial and temporal wetland loss to DPs, estimated the economic value of the KMC wetlands, and assessed the environmental consequences of wetland conversion for DPs. Sets of ortho-rectified and cloud-free multi-temporal Landsat MSS (1974) and Landsat TM/ETM+ images (30m) for 1986, 2006, and 2013 were analysed in a spatial and temporal framework. The 79m Landsat image (MSS) of 1974 was resampled and later filtered with subsequent 30m images using a majority filter method. An unsupervised classification approach was employed to characterize the wetlands and associated DPs. The classified DPs and wetland cover types were validated by reference to topographical maps (sheets) of 1974 at a scale of 1:50,000 obtained from Uganda Lands and Surveys, apriori knowledge and Google earth images corresponding to the same spatial and temporal frames. The IDRISI Selva-based Markov Chain model was employed to model future wetland loss to DPs. The Total Economic Valuation Approach (TEV) was employed to quantify selected use values of wetland economic benefits using the market price, replacement cost and contingent valuation techniques. The ecological implications of wetland loss focused on soil organic carbon (SOC) and hydrological impacts in the KMC wetlands. The estimated SOC was assessed with climatic data in order to infer the implication of SOC loss for local climate variability. The manual wet chemistry/oxidation method by Walkley-Black (1934) was adopted to estimate SOC in various wetland cover types. Hydrological impact assessments focused on water quality analysis in various wetland cover types, with major parameters being total nitrogen (TN), total phosphorous (TP) total dissolved solids – (TDS) and total suspended sediments (TSS). Hydrologic flow data parameters across the different wetland cover types in the KMC focused on water level, speed, stream width, and bed load. Results from analysis of the spatial-temporal wetland change revealed that by 2013 the KMC wetlands had lost almost half (47%) of their 1974 areal coverage, with 56% of this loss resulting from conversion to DPs. It is projected that 26% of the KMC wetlands will be lost to more DPs by 2040. Wetland loss is attributed to intensified economic activity and preference of Kampala as an industrial zone, weakness in the previous spatial planning of Kampala, and the general lack of information flow to various institutions involved in the establishment of DPs. The KMC wetlands provide a flow of economic benefits at a minimum approximated value of US$ 3,418 / ha / per year. It is revealed that a great deal of these economic benefits (88%) accrues to the local subsistence level in the form of livelihood products, incomes, and employment benefits. The 56% wetlands loss to DPs in the KMC by 2013 brings the minimum economic value lost to US$ 19,311,700 in the sampled wetlands, and projections of future wetland loss put the minimum economic loss at US$ 48,368,118 by 2040. Continuous degradation of these wetlands means serious economic costs to the government and local communities, as reflected in high replacement expenditures for wetland services, foregone incomes, subsistence livelihood support and alternative employment. The highest carbon (C) sinks were identified in forest swamps, palms, thickets and wetlands converted to agriculture, which accounted for 25% of the KMC wetlands by 2013, while the lowest total soil organic carbon (TSOC) range occurred in converted wetland cover types (converted wetlands to industrial and settlements) that occupied 47% of the study area. A general decrease in SOC sequestration from 1974 to 2013 across the KMC wetlands is identified, with the lowest C pool registered in 2013. The dwindling SOC banks are considered to be partly responsible for varying climate and related feedbacks on wetland benefits in the KMC. The hydrologic impacts of wetland loss are felt mainly in converted wetland cover types, in the form of compromised water quality, with increased nutrient pollution and TSS. These all create negative impacts on wetland hydrological services, particularly filtration, flood attenuation, recharge and discharge benefits, all of which have profound effects on biodiversity. There is an urgent need to reduce the scale of wetland diminution in the KMC. This will be achieved if mitigation and conservation measures are undertaken. Mitigation measures should include a revision of development plans, user sensitization on wetland economic values and enforcement of regulatory mechanisms. Conservation strategies should involve the use of economic incentives and disincentives which include: a revision of historic property rights to regulate wetland use, performance bonds or subsidies for environmentally friendly activities and taxes, fees or fines for unacceptable levels of degradation and tradable permits that utilise the concept of ‘wetland banks’ to ensure no further loss of the KMC wetlands to DPs. Future research should focus on modelling the response of wetland ecosystems to multiple threats and management interventions, and on a feasibility study of wetland restoration options and the implications for local people’s livelihoods in the KMC.
- Full Text:
- Date Issued: 2018
- Authors: Wasswa, Hannington
- Date: 2018
- Subjects: Wetland ecology -- Uganda -- Kampala , Wetlands -- Uganda -- Kampala Wetland management -- Uganda -- Kampala Hydrogeology
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/36409 , vital:33939
- Description: Wetland diminution for development projects (DPs) in the Kampala–Mukono Corridor (KMC) continues to pose threats to the socio-economic and ecological benefits of wetlands because decision-makers and wetland users at various levels often have insufficient knowledge of these benefits. This situation has resulted in unsustainable development decisions that accord little weight to wetlands and have allocated many of them to DPs. In order to inform decision making for optimal development in the KMC, the present study analysed the spatial and temporal wetland loss to DPs, estimated the economic value of the KMC wetlands, and assessed the environmental consequences of wetland conversion for DPs. Sets of ortho-rectified and cloud-free multi-temporal Landsat MSS (1974) and Landsat TM/ETM+ images (30m) for 1986, 2006, and 2013 were analysed in a spatial and temporal framework. The 79m Landsat image (MSS) of 1974 was resampled and later filtered with subsequent 30m images using a majority filter method. An unsupervised classification approach was employed to characterize the wetlands and associated DPs. The classified DPs and wetland cover types were validated by reference to topographical maps (sheets) of 1974 at a scale of 1:50,000 obtained from Uganda Lands and Surveys, apriori knowledge and Google earth images corresponding to the same spatial and temporal frames. The IDRISI Selva-based Markov Chain model was employed to model future wetland loss to DPs. The Total Economic Valuation Approach (TEV) was employed to quantify selected use values of wetland economic benefits using the market price, replacement cost and contingent valuation techniques. The ecological implications of wetland loss focused on soil organic carbon (SOC) and hydrological impacts in the KMC wetlands. The estimated SOC was assessed with climatic data in order to infer the implication of SOC loss for local climate variability. The manual wet chemistry/oxidation method by Walkley-Black (1934) was adopted to estimate SOC in various wetland cover types. Hydrological impact assessments focused on water quality analysis in various wetland cover types, with major parameters being total nitrogen (TN), total phosphorous (TP) total dissolved solids – (TDS) and total suspended sediments (TSS). Hydrologic flow data parameters across the different wetland cover types in the KMC focused on water level, speed, stream width, and bed load. Results from analysis of the spatial-temporal wetland change revealed that by 2013 the KMC wetlands had lost almost half (47%) of their 1974 areal coverage, with 56% of this loss resulting from conversion to DPs. It is projected that 26% of the KMC wetlands will be lost to more DPs by 2040. Wetland loss is attributed to intensified economic activity and preference of Kampala as an industrial zone, weakness in the previous spatial planning of Kampala, and the general lack of information flow to various institutions involved in the establishment of DPs. The KMC wetlands provide a flow of economic benefits at a minimum approximated value of US$ 3,418 / ha / per year. It is revealed that a great deal of these economic benefits (88%) accrues to the local subsistence level in the form of livelihood products, incomes, and employment benefits. The 56% wetlands loss to DPs in the KMC by 2013 brings the minimum economic value lost to US$ 19,311,700 in the sampled wetlands, and projections of future wetland loss put the minimum economic loss at US$ 48,368,118 by 2040. Continuous degradation of these wetlands means serious economic costs to the government and local communities, as reflected in high replacement expenditures for wetland services, foregone incomes, subsistence livelihood support and alternative employment. The highest carbon (C) sinks were identified in forest swamps, palms, thickets and wetlands converted to agriculture, which accounted for 25% of the KMC wetlands by 2013, while the lowest total soil organic carbon (TSOC) range occurred in converted wetland cover types (converted wetlands to industrial and settlements) that occupied 47% of the study area. A general decrease in SOC sequestration from 1974 to 2013 across the KMC wetlands is identified, with the lowest C pool registered in 2013. The dwindling SOC banks are considered to be partly responsible for varying climate and related feedbacks on wetland benefits in the KMC. The hydrologic impacts of wetland loss are felt mainly in converted wetland cover types, in the form of compromised water quality, with increased nutrient pollution and TSS. These all create negative impacts on wetland hydrological services, particularly filtration, flood attenuation, recharge and discharge benefits, all of which have profound effects on biodiversity. There is an urgent need to reduce the scale of wetland diminution in the KMC. This will be achieved if mitigation and conservation measures are undertaken. Mitigation measures should include a revision of development plans, user sensitization on wetland economic values and enforcement of regulatory mechanisms. Conservation strategies should involve the use of economic incentives and disincentives which include: a revision of historic property rights to regulate wetland use, performance bonds or subsidies for environmentally friendly activities and taxes, fees or fines for unacceptable levels of degradation and tradable permits that utilise the concept of ‘wetland banks’ to ensure no further loss of the KMC wetlands to DPs. Future research should focus on modelling the response of wetland ecosystems to multiple threats and management interventions, and on a feasibility study of wetland restoration options and the implications for local people’s livelihoods in the KMC.
- Full Text:
- Date Issued: 2018
The effects of environmental variability on the physiology and ecology of Cape stumpnose Rhabdosargus holubi (Steindachner, 1881) (Sparidae)
- Authors: Kisten, Yanasivan
- Date: 2018
- Subjects: Freshwater fishes -- South Africa , Fishes -- Ecology Freshwater fishes -- Ecology Estuarine ecology -- South Africa Estuaries -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/31424 , vital:31374
- Description: Estuaries are important nursery areas for early stages of marine estuarine-dependent fishes, such as the sparid Rhabdosargus holubi. Estuaries provide food, shelter from predators and optimal habitats and environmental conditions for growth and development. However, estuaries are environmentally dynamic and resident organisms must be able to adapt to rapid changes. Such changes are potentially further exacerbated anthropogenically by water and land use practices such as freshwater abstraction, impoundment, pollution and anthropogenically driven climatic change. An effective approach to better understanding the current and future impacts of these kinds of changes, is by assessing the environmental adaptability of organisms, especially to extreme conditions such as droughts and resulting water shortages, which are prevalent in some parts of southern Africa. This thesis examines the effect of various environmental changes such as salinity, turbidity and temperature on the ecology and physiology of a South African common endemic fish species, the Cape stumpnose, R. holubi. Previous work on the species have investigated short term impacts on physiology while this study investigates medium to short term impacts. The specie’s wide distribution in South Africa and tolerance enabled a range of environmental, ecological and physiological relationships to be tested in the context of a changing world. These included: 1) determining the relationship between environmental variability and the distribution and abundance of R. holubi larvae in 25 estuaries along the temperate coast of South Africa; 2) determining the relationship between environmental variability and the movement of larvae and juveniles within two permanently open estuaries; 3) determining the impact of shock and acclimatization on R. holubi salinity tolerance ranges under hypersaline conditions; 4) II determining the impact of hypersalinity on the potential long term impacts growth and skeletal deformities of juvenile R. holubi in aquaria. The findings of these studies suggest that larval occurrence and density within estuaries is a function of salinity and turbidity, by proxy indicating a preference for high freshwater inflow especially in estuary types such as permanently open estuaries. The movement of larvae and juveniles within these estuaries is also mediated by salinity, turbidity and temperature, indicating the importance of seasonality along with environmental conditions and potential olfactory recruitment cues driven by freshwater flow. Tolerance experiments showed that slower acclimation to higher salinities can expand the previously reported tolerance range indicating the potential for adaptation. Physiological experiments showed negative impacts on respiration at salinities exceeding 45, indicating potential long-term physiological effects in hypersaline conditions. Further, living at high salinities for extended periods may have potentially negative effects on long term physiology, particularly growth and skeletal development. The overall results indicate that low salinity (5–18), high turbidity (20–30 NTU) and high temperature (5–22°C) are integral to the distribution and abundance of the species in permanently open estuaries. This conforms to the general rule that estuarine-associated marine fish have higher growth rates in salinities of 12-19. However, juveniles are also adapted to survive at higher salinities for long periods (2 months in the current thesis). This explains why R. holubi is one of the few species in the estuarine fish community that may persist during droughts. The predicted future changes in coastal temperatures and rainfall by climate change investigators, are likely to result in range shifts and changes in recruitment times of estuarine fish communities. The current work addresses novel aspects of the ecology and physiology of R. holubi and indicates that this species will play an increasingly important role within the estuaries of South Africa.
- Full Text:
- Date Issued: 2018
- Authors: Kisten, Yanasivan
- Date: 2018
- Subjects: Freshwater fishes -- South Africa , Fishes -- Ecology Freshwater fishes -- Ecology Estuarine ecology -- South Africa Estuaries -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/31424 , vital:31374
- Description: Estuaries are important nursery areas for early stages of marine estuarine-dependent fishes, such as the sparid Rhabdosargus holubi. Estuaries provide food, shelter from predators and optimal habitats and environmental conditions for growth and development. However, estuaries are environmentally dynamic and resident organisms must be able to adapt to rapid changes. Such changes are potentially further exacerbated anthropogenically by water and land use practices such as freshwater abstraction, impoundment, pollution and anthropogenically driven climatic change. An effective approach to better understanding the current and future impacts of these kinds of changes, is by assessing the environmental adaptability of organisms, especially to extreme conditions such as droughts and resulting water shortages, which are prevalent in some parts of southern Africa. This thesis examines the effect of various environmental changes such as salinity, turbidity and temperature on the ecology and physiology of a South African common endemic fish species, the Cape stumpnose, R. holubi. Previous work on the species have investigated short term impacts on physiology while this study investigates medium to short term impacts. The specie’s wide distribution in South Africa and tolerance enabled a range of environmental, ecological and physiological relationships to be tested in the context of a changing world. These included: 1) determining the relationship between environmental variability and the distribution and abundance of R. holubi larvae in 25 estuaries along the temperate coast of South Africa; 2) determining the relationship between environmental variability and the movement of larvae and juveniles within two permanently open estuaries; 3) determining the impact of shock and acclimatization on R. holubi salinity tolerance ranges under hypersaline conditions; 4) II determining the impact of hypersalinity on the potential long term impacts growth and skeletal deformities of juvenile R. holubi in aquaria. The findings of these studies suggest that larval occurrence and density within estuaries is a function of salinity and turbidity, by proxy indicating a preference for high freshwater inflow especially in estuary types such as permanently open estuaries. The movement of larvae and juveniles within these estuaries is also mediated by salinity, turbidity and temperature, indicating the importance of seasonality along with environmental conditions and potential olfactory recruitment cues driven by freshwater flow. Tolerance experiments showed that slower acclimation to higher salinities can expand the previously reported tolerance range indicating the potential for adaptation. Physiological experiments showed negative impacts on respiration at salinities exceeding 45, indicating potential long-term physiological effects in hypersaline conditions. Further, living at high salinities for extended periods may have potentially negative effects on long term physiology, particularly growth and skeletal development. The overall results indicate that low salinity (5–18), high turbidity (20–30 NTU) and high temperature (5–22°C) are integral to the distribution and abundance of the species in permanently open estuaries. This conforms to the general rule that estuarine-associated marine fish have higher growth rates in salinities of 12-19. However, juveniles are also adapted to survive at higher salinities for long periods (2 months in the current thesis). This explains why R. holubi is one of the few species in the estuarine fish community that may persist during droughts. The predicted future changes in coastal temperatures and rainfall by climate change investigators, are likely to result in range shifts and changes in recruitment times of estuarine fish communities. The current work addresses novel aspects of the ecology and physiology of R. holubi and indicates that this species will play an increasingly important role within the estuaries of South Africa.
- Full Text:
- Date Issued: 2018
The effects of frost on Albany subtropical thicket and nama-karoo shrubland in South Africa
- Authors: Duker, Robert
- Date: 2018
- Subjects: Shrubland ecology , Desert ecology -- South Africa Ecological surveys -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/29951 , vital:30799
- Description: Numerous treeless shrublands exist in areas where climates should support tree growth. In South Africa, the predominantly lowland Albany Subtropical Thicket (thicket), and the predominantly upland Nama-Karoo semi-desert shrubland share a boundary that is often abrupt and analogous to a forest-shrubland alpine ‘treeline’. This boundary exists across similar climatic and edaphic conditions, and field observations and leaf-level experiments suggest that certain thicket component species have lower levels of frost tolerance than the Nama-Karoo shrubs. The hypothesis is that the occurrence of sub-zero temperatures and frost dictates the position of this boundary at both the local landscape and broader regional levels. I test this hypothesis by quantifying leaf-level and whole-plant freezing tolerance of thicket and Nama-Karoo shrubland species, in relation to their local- and regional-scale distribution, and by modelling the occurrence of frost in the mountainous areas of the coastal lowlands relation to 1) naturally occurring boundaries between these two vegetation types, and 2) levels of aboveground net primary productivity (NPP) of Portulacaria afra Jacq. (spekboom) cuttings (planted with the aim of restoring livestock-degraded thicket). I found that the observed and modelled occurrence of frost in the local landscape has significant negative influences on the photosynthetic health, survival and growth rates of thicket component species, and that leaf-level freezing tolerance of evergreen thicket and Nama-Karoo shrubland species is strongly related to their broader regional-scale distributional thresholds. These results support the hypothesis that the occurrence of sub-zero temperatures and frost play a major role in determining the local- and regional-scale distribution of thicket and Nama-Karoo shrubland species, via their reliance on frost-defined refugia at a variety of different scales, and that the once-widespread and regionally dominant thicket vegetation contracted into small climatic refugia during the Last Glacial Maximum (LGM). These results also have major implications for landscape- and regional-level planning of livestock-degraded thicket restoration efforts that use planting of spekboom as an ecosystem engineer, and for predicting boundary shifts under the predicted future warming of global climates.
- Full Text:
- Date Issued: 2018
- Authors: Duker, Robert
- Date: 2018
- Subjects: Shrubland ecology , Desert ecology -- South Africa Ecological surveys -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/29951 , vital:30799
- Description: Numerous treeless shrublands exist in areas where climates should support tree growth. In South Africa, the predominantly lowland Albany Subtropical Thicket (thicket), and the predominantly upland Nama-Karoo semi-desert shrubland share a boundary that is often abrupt and analogous to a forest-shrubland alpine ‘treeline’. This boundary exists across similar climatic and edaphic conditions, and field observations and leaf-level experiments suggest that certain thicket component species have lower levels of frost tolerance than the Nama-Karoo shrubs. The hypothesis is that the occurrence of sub-zero temperatures and frost dictates the position of this boundary at both the local landscape and broader regional levels. I test this hypothesis by quantifying leaf-level and whole-plant freezing tolerance of thicket and Nama-Karoo shrubland species, in relation to their local- and regional-scale distribution, and by modelling the occurrence of frost in the mountainous areas of the coastal lowlands relation to 1) naturally occurring boundaries between these two vegetation types, and 2) levels of aboveground net primary productivity (NPP) of Portulacaria afra Jacq. (spekboom) cuttings (planted with the aim of restoring livestock-degraded thicket). I found that the observed and modelled occurrence of frost in the local landscape has significant negative influences on the photosynthetic health, survival and growth rates of thicket component species, and that leaf-level freezing tolerance of evergreen thicket and Nama-Karoo shrubland species is strongly related to their broader regional-scale distributional thresholds. These results support the hypothesis that the occurrence of sub-zero temperatures and frost play a major role in determining the local- and regional-scale distribution of thicket and Nama-Karoo shrubland species, via their reliance on frost-defined refugia at a variety of different scales, and that the once-widespread and regionally dominant thicket vegetation contracted into small climatic refugia during the Last Glacial Maximum (LGM). These results also have major implications for landscape- and regional-level planning of livestock-degraded thicket restoration efforts that use planting of spekboom as an ecosystem engineer, and for predicting boundary shifts under the predicted future warming of global climates.
- Full Text:
- Date Issued: 2018
The extraction, quantification and application of high-value biological compounds from olive oil processing waste
- Authors: Postma-Botha, Marthie
- Date: 2018
- Subjects: Organic compounds , Biochemistry , Biomass energy , Olive oil industry
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/34383 , vital:33371
- Description: Olive oil processing waste (pomace) as a by-product of the olive oil industry is regarded as a rich source of high-value biological compounds exhibiting antioxidant potential. The objective of the present work was to obtain a concentrated extract of high-value biological antioxidants from the pomace. The effect of extraction conditions on the concentration of the bioactive compounds in the extracts was investigated. The simultaneous recovery of both hydrophilic and lipophilic high-value biological compounds exhibiting antioxidant potential was achieved through a one-step extraction method under reduced pressure using a non-toxic solvent blend. A multilevel experimental design was implemented with the aim of optimising the recovery of selected compounds, namely, hydroxytyrosol, tyrosol, oleuropein, α-tocopherol and squalene from olive pomace by using solvent blends of n-heptane, d-limonene, ethanol and water. The factors considered were: extraction time, percentage composition of solvent blends and extraction temperature. The results suggested that a good recovery of the hydrophilic polyphenolic compounds, namely, hydroxytyrosol, tyrosol and oleuropein, as well as the lipophilic compounds, α-tocopherol and squalene may be achieved at a solvent temperature of 60°C at 400 mbar with a solvent blend of 30% n-heptane, 50% ethanol and 20% water and an extraction time of two hours. It was found that freeze-drying the pomace before extraction minimised production of artefacts, avoided degradation of biophenols, ensured long term stability of a reproducible sample and achieved better recovery of important hydrophilic and lipophilic bioactive compounds. Since the bioactive compounds are temperature sensitive, the extraction was performed under reduced pressure in order to reduce solvent reflux temperature and to improve extraction efficiency. The quantitative and qualitative determinations of the aforementioned high-value compounds were performed by high-performance liquid chromatography (HPLC), which revealed that the hydrophilic polyphenolic as well as the lipophilic α-tocopherol and squalene were present. In this study hydroxytyrosol, tyrosol, oleuropein, α-tocopherol and squalene were extracted from the pomace of two olive cultivars (Frantoio and Coratina). A comparison among the two cultivars showed quantitative differences between the two cultivars in all five high-value biological compounds and in the antioxidant capacity of the extracts evaluated by measuring the radical scavenging effect on 1,1-diphenyl-2- picrylhydrazyl (DPPH) free radical. Coratina cultivar was found to have a significantly higher antioxidant capacity than Frantoio due to the much greater oleuropein content in the Coratina compared to the Frantoio although Frantoio had a significantly greater amount of hydroxytyrosol. The stability of olive waste extracts stored at four temperatures was also investigated and the results show that increased temperatures caused greater extent of degradation of both the hydrophilic polyphenolic and lipophilic compounds. The proposed optimum storage condition for the olive pomace extracts was found to be at 5°C in the absence of light. The extracts were incorporated into two cosmetic formulations and were found, from a stability study, to be stable at room temperature and optimally stable at 5°C in the absence of light.
- Full Text:
- Date Issued: 2018
- Authors: Postma-Botha, Marthie
- Date: 2018
- Subjects: Organic compounds , Biochemistry , Biomass energy , Olive oil industry
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/34383 , vital:33371
- Description: Olive oil processing waste (pomace) as a by-product of the olive oil industry is regarded as a rich source of high-value biological compounds exhibiting antioxidant potential. The objective of the present work was to obtain a concentrated extract of high-value biological antioxidants from the pomace. The effect of extraction conditions on the concentration of the bioactive compounds in the extracts was investigated. The simultaneous recovery of both hydrophilic and lipophilic high-value biological compounds exhibiting antioxidant potential was achieved through a one-step extraction method under reduced pressure using a non-toxic solvent blend. A multilevel experimental design was implemented with the aim of optimising the recovery of selected compounds, namely, hydroxytyrosol, tyrosol, oleuropein, α-tocopherol and squalene from olive pomace by using solvent blends of n-heptane, d-limonene, ethanol and water. The factors considered were: extraction time, percentage composition of solvent blends and extraction temperature. The results suggested that a good recovery of the hydrophilic polyphenolic compounds, namely, hydroxytyrosol, tyrosol and oleuropein, as well as the lipophilic compounds, α-tocopherol and squalene may be achieved at a solvent temperature of 60°C at 400 mbar with a solvent blend of 30% n-heptane, 50% ethanol and 20% water and an extraction time of two hours. It was found that freeze-drying the pomace before extraction minimised production of artefacts, avoided degradation of biophenols, ensured long term stability of a reproducible sample and achieved better recovery of important hydrophilic and lipophilic bioactive compounds. Since the bioactive compounds are temperature sensitive, the extraction was performed under reduced pressure in order to reduce solvent reflux temperature and to improve extraction efficiency. The quantitative and qualitative determinations of the aforementioned high-value compounds were performed by high-performance liquid chromatography (HPLC), which revealed that the hydrophilic polyphenolic as well as the lipophilic α-tocopherol and squalene were present. In this study hydroxytyrosol, tyrosol, oleuropein, α-tocopherol and squalene were extracted from the pomace of two olive cultivars (Frantoio and Coratina). A comparison among the two cultivars showed quantitative differences between the two cultivars in all five high-value biological compounds and in the antioxidant capacity of the extracts evaluated by measuring the radical scavenging effect on 1,1-diphenyl-2- picrylhydrazyl (DPPH) free radical. Coratina cultivar was found to have a significantly higher antioxidant capacity than Frantoio due to the much greater oleuropein content in the Coratina compared to the Frantoio although Frantoio had a significantly greater amount of hydroxytyrosol. The stability of olive waste extracts stored at four temperatures was also investigated and the results show that increased temperatures caused greater extent of degradation of both the hydrophilic polyphenolic and lipophilic compounds. The proposed optimum storage condition for the olive pomace extracts was found to be at 5°C in the absence of light. The extracts were incorporated into two cosmetic formulations and were found, from a stability study, to be stable at room temperature and optimally stable at 5°C in the absence of light.
- Full Text:
- Date Issued: 2018
The influence of legislation and regulations on strategy in public entities
- Authors: Govender, Kasavan
- Date: 2018
- Subjects: Government business enterprises -- Law and legislation -- South Africa -- Eastern Cape , Government corporations -- Law and legislation -- South Africa -- Eastern Cape Industrial development projects -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/22178 , vital:29866
- Description: While citizens require products and services to meet their needs, government goes about designing systems and processes to meet that need through the setting of goals and objectives. Many methods are adopted for that to happen. However, one of the ways that this occurs is through legislation and regulations and the formation of public entities. On the other hand, strategy is needed to devise techniques and plans to meet needs, goals and aspirations of government in the most efficient manner. At face value it would seem that the enactment of certain legislation and regulations seems to make the need for strategy obsolete especially since there is proliferation of national, provincial and local strategies that only need implementation. The purpose of this research is to determine the influence of legislation and regulations on strategy in public entities focusing on the Eastern Cape Province and using the Eastern Cape Development Corporation as a case study. The study focused on the assessment of the relationship between the public entities and the shareholder through the use of legislation and regulations. The context for the research is prefixed on creating an understanding of the public administrative system and especially the components of the New Public Management approach that deal with the principal-agent and public choice theory. The study assessed the public administrative system and its relationships in order to locate the use of legislation and regulations and public entities to deliver products and services to citizens. Likewise the concept of strategy was examined from three perspectives namely that strategy is about goal consciousness, strategy involves leadership and strategy is multifaceted in its nature. In order to undertake the study a document review was conducted on the legislation and regulations, semi-structured interviews were held with the principal or shareholder and a questionnaire was administered to executives and senior managers in public entities in the Eastern Cape Province. The findings revealed that there is a relationship between legislation and regulations and strategy on the one hand and on the other strategy appears to be ineffective due to a lack of planning, key role players’ involvement in the process, leadership, inflexible compliance and restrictive conditions. The research further found that strategy involves implementation of legislation and regulations which support the rise of the regulatory state. The study proposes a normative model that is built around defining the nature of strategy and predetermining the definition of roles in the system.
- Full Text:
- Date Issued: 2018
- Authors: Govender, Kasavan
- Date: 2018
- Subjects: Government business enterprises -- Law and legislation -- South Africa -- Eastern Cape , Government corporations -- Law and legislation -- South Africa -- Eastern Cape Industrial development projects -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/22178 , vital:29866
- Description: While citizens require products and services to meet their needs, government goes about designing systems and processes to meet that need through the setting of goals and objectives. Many methods are adopted for that to happen. However, one of the ways that this occurs is through legislation and regulations and the formation of public entities. On the other hand, strategy is needed to devise techniques and plans to meet needs, goals and aspirations of government in the most efficient manner. At face value it would seem that the enactment of certain legislation and regulations seems to make the need for strategy obsolete especially since there is proliferation of national, provincial and local strategies that only need implementation. The purpose of this research is to determine the influence of legislation and regulations on strategy in public entities focusing on the Eastern Cape Province and using the Eastern Cape Development Corporation as a case study. The study focused on the assessment of the relationship between the public entities and the shareholder through the use of legislation and regulations. The context for the research is prefixed on creating an understanding of the public administrative system and especially the components of the New Public Management approach that deal with the principal-agent and public choice theory. The study assessed the public administrative system and its relationships in order to locate the use of legislation and regulations and public entities to deliver products and services to citizens. Likewise the concept of strategy was examined from three perspectives namely that strategy is about goal consciousness, strategy involves leadership and strategy is multifaceted in its nature. In order to undertake the study a document review was conducted on the legislation and regulations, semi-structured interviews were held with the principal or shareholder and a questionnaire was administered to executives and senior managers in public entities in the Eastern Cape Province. The findings revealed that there is a relationship between legislation and regulations and strategy on the one hand and on the other strategy appears to be ineffective due to a lack of planning, key role players’ involvement in the process, leadership, inflexible compliance and restrictive conditions. The research further found that strategy involves implementation of legislation and regulations which support the rise of the regulatory state. The study proposes a normative model that is built around defining the nature of strategy and predetermining the definition of roles in the system.
- Full Text:
- Date Issued: 2018