Community policing and partnership policing : a case study of shared responsibilities between the police and Alice community
- Authors: Manganyi, Foster Mzamani
- Date: 2017
- Subjects: Police-community relations -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , DPhil
- Identifier: http://hdl.handle.net/10353/8386 , vital:32558
- Description: The purpose of this study was to explore the shared responsibilities between the police and the community on crime prevention. Various authorities such as Sir Robert Peel (1829), Sower (1957), William and Kelling (1982), Roelofse (2007), to mention a few, had been advocating community policing as an essential component of democratic policing. In an attempt to understand the shared responsibilities between the police and the community, a thorough literature review had been presented in chapter two. Through the intertwined approach of secondary data, explorations had been noted on the shared responsibility between the police and the community. Literature and theoretical review had been presented in the thesis to clarify critical aspects of the topic. Triangulation approach was adopted for the purpose of this study. The researcher triangulated, methodologies, sampling methods, data collection methods as well as data analysis methods. Using qualitative approach in Phase A, data was collected through structured interview, observation and content analysis which was thematically presented. The quantitative data (Phase B) was collected through structured questionnaire. In case of codding and analysis SPSS was utilised. The findings of the study in chapter six shows the shared responsibilities between the police and the community exist within Alice. Moreover, the findings shows that there is a need for community empowerment on human rights and its applicability.
- Full Text:
- Date Issued: 2017
- Authors: Manganyi, Foster Mzamani
- Date: 2017
- Subjects: Police-community relations -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , DPhil
- Identifier: http://hdl.handle.net/10353/8386 , vital:32558
- Description: The purpose of this study was to explore the shared responsibilities between the police and the community on crime prevention. Various authorities such as Sir Robert Peel (1829), Sower (1957), William and Kelling (1982), Roelofse (2007), to mention a few, had been advocating community policing as an essential component of democratic policing. In an attempt to understand the shared responsibilities between the police and the community, a thorough literature review had been presented in chapter two. Through the intertwined approach of secondary data, explorations had been noted on the shared responsibility between the police and the community. Literature and theoretical review had been presented in the thesis to clarify critical aspects of the topic. Triangulation approach was adopted for the purpose of this study. The researcher triangulated, methodologies, sampling methods, data collection methods as well as data analysis methods. Using qualitative approach in Phase A, data was collected through structured interview, observation and content analysis which was thematically presented. The quantitative data (Phase B) was collected through structured questionnaire. In case of codding and analysis SPSS was utilised. The findings of the study in chapter six shows the shared responsibilities between the police and the community exist within Alice. Moreover, the findings shows that there is a need for community empowerment on human rights and its applicability.
- Full Text:
- Date Issued: 2017
Community structure and trophic relations in marine tufa stromatolite pools of the Eastern Cape
- Authors: Rishworth, Gavin Midgley
- Date: 2017
- Subjects: Bioturbation -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/7116 , vital:21236
- Description: Microbialites were the dominant life-form of most shallow oceans during the Precambrian. These structures are formed by the deposition of calcium carbonate by cyanobacteria as well as the binding and trapping of sediment by these and other microalgae. In modern environments they are scarce due to several factors, including grazing pressures by metazoans, altered calcium carbonate saturation states of seawater and competition with macroalgae. The recent discovery of an extensive network of actively accreting layered microbialites (stromatolites) along the South African coastline is potentially informative from this perspective. These stromatolites form within the peritidal zone, at the interface of groundwater seepage and periodic marine incursion, forming pools trapped by the accreting fabric. The aim of this thesis was to characterise the ecosystem dynamics of a representative selection of the South African locations. During a comprehensive monthly assessment over an annual cycle, as well as for additional seasonal collections, physico-chemical measurements were monitored together with biological components such as benthic and pelagic microalgae as well as the invertebrate fauna inhabiting the stromatolite pools. These components were then assessed in terms of the potential physical and biological drivers which might explain patterns of variability. Finally, to link all of the ecosystem components, a food-web analysis was conducted, to determine the trophic linkages and, importantly, the reliance by the various consumer organisms on the stromatolite material as a food resource. Results show that the stromatolite pools are driven by a regular interplay between freshwater and marine salinity states, this being determined by tidal amplitude and ocean storm cycles. Furthermore, marine incursion represents the primary source of phosphorus for the stromatolite pools, while available nitrogen is consistently provided by the freshwater inlet stream at each site. This results in an optimum zone of primary biomass within the main stromatolite pool supported by nutrient conditions, while the shifts in salinity state occurring over a weekly tidal schedule likely exclude organisms and macrophytes that are not halotolerant. This is reflected in the benthic microalgae that form the stromatolite accretions in that they are primarily driven by salinity conditions, in addition to seasonal patterns. Interestingly, the variable nutrient conditions, both between sites and temporally, did not contribute as an important driver of the benthic microalgae but did significantly relate to the pelagic microalgae (phytoplankton). This, together with the higher biomass of benthic microalgae compared to its pelagic counterpart, suggests that the stromatolite pools are a benthic-driven system. The short duration of water retention within the stromatolite pools as a result of the constant freshwater inflow, likely also precludes nutrient build-up and favours the benthic, sessile ecosystem component, especially the stromatolite-forming microalgae. In terms of the metazoan infauna, the South African stromatolite pools support a persistent assemblage. This might be surprising given the apparently destructive influence of grazing and burrowing animals on microbial mats in terms of restricting the formation of layered accretions. However, metazoans that burrow within the stromatolite fabric were observed to coexist with clear, layered accretions. This supports the observations in some other modern microbialite habitats to suggest that metazoan disruption is clearly not the only or primary factor responsible for modern microbialite scarcity. When assessing the possible drivers of the metazoan community occupying the stromatolite matrix, both salinity patterns and resource conditions in terms of nutrient supply and macroalgal cover were consistently best related to infaunal abundance and presence/absence. This further demonstrates the role of salinity conditions in terms of providing a habitat that is restrictive to most metazoan organisms, while also suggesting that the metazoans are responding to macroalgal rather than the stromatolite microalgal conditions. To further develop this observation, the results from the stable isotope work clearly reflect a dominance of pool macroalgae in the diets of invertebrate consumers, with little to no stromatolite material consumed. This suggests that there is limited apparent destructive grazing influence by the metazoans on the stromatolite matrix, in addition to the burrowing bioturbation mentioned previously. Furthermore, the metazoan grazers may be indirectly benefitting the stromatolites by restricting macroalgal biomass, which might otherwise outcompete its microalgal counterpart. This study provides a valuable understanding of benthic-driven peritidal stromatolite ecosystems, and also, from a geological perspective of past stromatolite habitats, suggests some of the mechanisms as to why metazoans may be able to coexist with layered microbialites. Given the threats to similar habitats globally, especially in terms of water resources, management measures necessary to ensure stromatolite persistence in modern environments such as these are proposed. The possible ecological role of peritidal stromatolite habitats within the broader environment, as well as recommendations for future work, is also contextualised.
- Full Text:
- Date Issued: 2017
- Authors: Rishworth, Gavin Midgley
- Date: 2017
- Subjects: Bioturbation -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/7116 , vital:21236
- Description: Microbialites were the dominant life-form of most shallow oceans during the Precambrian. These structures are formed by the deposition of calcium carbonate by cyanobacteria as well as the binding and trapping of sediment by these and other microalgae. In modern environments they are scarce due to several factors, including grazing pressures by metazoans, altered calcium carbonate saturation states of seawater and competition with macroalgae. The recent discovery of an extensive network of actively accreting layered microbialites (stromatolites) along the South African coastline is potentially informative from this perspective. These stromatolites form within the peritidal zone, at the interface of groundwater seepage and periodic marine incursion, forming pools trapped by the accreting fabric. The aim of this thesis was to characterise the ecosystem dynamics of a representative selection of the South African locations. During a comprehensive monthly assessment over an annual cycle, as well as for additional seasonal collections, physico-chemical measurements were monitored together with biological components such as benthic and pelagic microalgae as well as the invertebrate fauna inhabiting the stromatolite pools. These components were then assessed in terms of the potential physical and biological drivers which might explain patterns of variability. Finally, to link all of the ecosystem components, a food-web analysis was conducted, to determine the trophic linkages and, importantly, the reliance by the various consumer organisms on the stromatolite material as a food resource. Results show that the stromatolite pools are driven by a regular interplay between freshwater and marine salinity states, this being determined by tidal amplitude and ocean storm cycles. Furthermore, marine incursion represents the primary source of phosphorus for the stromatolite pools, while available nitrogen is consistently provided by the freshwater inlet stream at each site. This results in an optimum zone of primary biomass within the main stromatolite pool supported by nutrient conditions, while the shifts in salinity state occurring over a weekly tidal schedule likely exclude organisms and macrophytes that are not halotolerant. This is reflected in the benthic microalgae that form the stromatolite accretions in that they are primarily driven by salinity conditions, in addition to seasonal patterns. Interestingly, the variable nutrient conditions, both between sites and temporally, did not contribute as an important driver of the benthic microalgae but did significantly relate to the pelagic microalgae (phytoplankton). This, together with the higher biomass of benthic microalgae compared to its pelagic counterpart, suggests that the stromatolite pools are a benthic-driven system. The short duration of water retention within the stromatolite pools as a result of the constant freshwater inflow, likely also precludes nutrient build-up and favours the benthic, sessile ecosystem component, especially the stromatolite-forming microalgae. In terms of the metazoan infauna, the South African stromatolite pools support a persistent assemblage. This might be surprising given the apparently destructive influence of grazing and burrowing animals on microbial mats in terms of restricting the formation of layered accretions. However, metazoans that burrow within the stromatolite fabric were observed to coexist with clear, layered accretions. This supports the observations in some other modern microbialite habitats to suggest that metazoan disruption is clearly not the only or primary factor responsible for modern microbialite scarcity. When assessing the possible drivers of the metazoan community occupying the stromatolite matrix, both salinity patterns and resource conditions in terms of nutrient supply and macroalgal cover were consistently best related to infaunal abundance and presence/absence. This further demonstrates the role of salinity conditions in terms of providing a habitat that is restrictive to most metazoan organisms, while also suggesting that the metazoans are responding to macroalgal rather than the stromatolite microalgal conditions. To further develop this observation, the results from the stable isotope work clearly reflect a dominance of pool macroalgae in the diets of invertebrate consumers, with little to no stromatolite material consumed. This suggests that there is limited apparent destructive grazing influence by the metazoans on the stromatolite matrix, in addition to the burrowing bioturbation mentioned previously. Furthermore, the metazoan grazers may be indirectly benefitting the stromatolites by restricting macroalgal biomass, which might otherwise outcompete its microalgal counterpart. This study provides a valuable understanding of benthic-driven peritidal stromatolite ecosystems, and also, from a geological perspective of past stromatolite habitats, suggests some of the mechanisms as to why metazoans may be able to coexist with layered microbialites. Given the threats to similar habitats globally, especially in terms of water resources, management measures necessary to ensure stromatolite persistence in modern environments such as these are proposed. The possible ecological role of peritidal stromatolite habitats within the broader environment, as well as recommendations for future work, is also contextualised.
- Full Text:
- Date Issued: 2017
Community ‘Broadband Islands’ for digital government access in rural South Africa
- Terzoli, Alfredo, Siebörger, Ingrid, Gumbo, Sibukelo
- Authors: Terzoli, Alfredo , Siebörger, Ingrid , Gumbo, Sibukelo
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/431248 , vital:72758 , https://www.academic-bookshop.com/ourshop/prod_6128029-ECDG-2017-PDF-Proceedings-of-the-17th-European-Conference-on-Digital-Government.html
- Description: In the developing world, one of the main obstacles to the realization of the potential of digital government in rendering services to citizens is the lack of access infrastructure. In this paper we present a model for the diffusion of Internet connectivity and access to computing infrastructure in rural communities in South Africa, through the aggregation of inde-pendent small and micro networks. The model is based on multi-year experimentation in the Siyakhula Living Lab, a long term joint venture between the Telkom Centres of Excellence hosted at Rhodes Universi-ty and the University of Fort Hare in South Africa. At the core of the model is the concept of ‘Broadband Island’, a high speed LAN realized through easy-to-deploy wireless technologies connecting groups of nearby schools. Each connected school, doubling as Digital Access Nodes for the community, hosts computing infrastructure in a serv-ers/thin clients configuration. Two schools belonging to the Broadband Island are then connected to the Internet with whatever technique makes sense within that specific geographical area: VSAT, microwave link, fibre etc. Each Broadband Island can be provisioned and support-ed by a variety of independent entities (such as Municipalities, Educa-tion Districts, NGOs, local action groups etc), possibly combined in con-sortia and in some cases using a Public Private Partnership format.
- Full Text:
- Date Issued: 2017
- Authors: Terzoli, Alfredo , Siebörger, Ingrid , Gumbo, Sibukelo
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/431248 , vital:72758 , https://www.academic-bookshop.com/ourshop/prod_6128029-ECDG-2017-PDF-Proceedings-of-the-17th-European-Conference-on-Digital-Government.html
- Description: In the developing world, one of the main obstacles to the realization of the potential of digital government in rendering services to citizens is the lack of access infrastructure. In this paper we present a model for the diffusion of Internet connectivity and access to computing infrastructure in rural communities in South Africa, through the aggregation of inde-pendent small and micro networks. The model is based on multi-year experimentation in the Siyakhula Living Lab, a long term joint venture between the Telkom Centres of Excellence hosted at Rhodes Universi-ty and the University of Fort Hare in South Africa. At the core of the model is the concept of ‘Broadband Island’, a high speed LAN realized through easy-to-deploy wireless technologies connecting groups of nearby schools. Each connected school, doubling as Digital Access Nodes for the community, hosts computing infrastructure in a serv-ers/thin clients configuration. Two schools belonging to the Broadband Island are then connected to the Internet with whatever technique makes sense within that specific geographical area: VSAT, microwave link, fibre etc. Each Broadband Island can be provisioned and support-ed by a variety of independent entities (such as Municipalities, Educa-tion Districts, NGOs, local action groups etc), possibly combined in con-sortia and in some cases using a Public Private Partnership format.
- Full Text:
- Date Issued: 2017
Community-based natural resource use and management of Bigodi Wetland Sanctuary, Uganda, for livelihood benefits
- Gosling, Amanda, Shackleton, Charlie M, Gambiza, James
- Authors: Gosling, Amanda , Shackleton, Charlie M , Gambiza, James
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/60844 , vital:27839 , https://doi.org/10.1007/s11273-017-9546-y
- Description: publisher version , Conservation and sustainable management of wetlands requires participation of local stakeholders, including communities. The Bigodi Wetland is unusual because it is situated in a common property landscape but the local community has been running a successful community-based natural resource management programme (CBNRM) for the wetland for over a decade. Whilst external visitors to the wetland provide ecotourism revenues we sought to quantify community benefits through the use of wetland goods such as firewood, plant fibres, and the like, and costs associated with wild animals damaging farming activities. We interviewed 68 households living close to the wetland and valued their cash and non-cash incomes from farming and collection of non-timber forest products (NTFPs) and water. The majority of households collected a wide variety of plant and fish resources and water from the wetland for household use and livestock. Overall, 53% of total household cash and non-cash income was from collected products, mostly the wetland, 28% from arable agriculture, 12% from livestock and 7% from employment and cash transfers. Female-headed households had lower incomes than male-headed ones, and with a greater reliance on NTFPs. Annual losses due to wildlife damage were estimated at 4.2% of total gross income. Most respondents felt that the wetland was important for their livelihoods, with more than 80% identifying health, education, craft materials and firewood as key benefits. Ninety-five percent felt that the wetland was in a good condition and that most residents observed the agreed CBNRM rules regarding use of the wetland. This study confirms the success of the locally run CBNRM processes underlying the significant role that the wetland plays in local livelihoods.
- Full Text:
- Date Issued: 2017
- Authors: Gosling, Amanda , Shackleton, Charlie M , Gambiza, James
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/60844 , vital:27839 , https://doi.org/10.1007/s11273-017-9546-y
- Description: publisher version , Conservation and sustainable management of wetlands requires participation of local stakeholders, including communities. The Bigodi Wetland is unusual because it is situated in a common property landscape but the local community has been running a successful community-based natural resource management programme (CBNRM) for the wetland for over a decade. Whilst external visitors to the wetland provide ecotourism revenues we sought to quantify community benefits through the use of wetland goods such as firewood, plant fibres, and the like, and costs associated with wild animals damaging farming activities. We interviewed 68 households living close to the wetland and valued their cash and non-cash incomes from farming and collection of non-timber forest products (NTFPs) and water. The majority of households collected a wide variety of plant and fish resources and water from the wetland for household use and livestock. Overall, 53% of total household cash and non-cash income was from collected products, mostly the wetland, 28% from arable agriculture, 12% from livestock and 7% from employment and cash transfers. Female-headed households had lower incomes than male-headed ones, and with a greater reliance on NTFPs. Annual losses due to wildlife damage were estimated at 4.2% of total gross income. Most respondents felt that the wetland was important for their livelihoods, with more than 80% identifying health, education, craft materials and firewood as key benefits. Ninety-five percent felt that the wetland was in a good condition and that most residents observed the agreed CBNRM rules regarding use of the wetland. This study confirms the success of the locally run CBNRM processes underlying the significant role that the wetland plays in local livelihoods.
- Full Text:
- Date Issued: 2017
Comparative analysis of zero-tillage and conventional tillage practices in the Amahlathi local municipality of the Eastern Cape province of South Africa
- Authors: Gomo, Zintle
- Date: 2017
- Subjects: Tillage--South Africa--Eastern Cape Farms, Small--South Africa--Eastern Cape No-tillage--South Africa--Eastern Cape
- Language: English
- Type: Thesis , Masters , Agricultural Economics
- Identifier: http://hdl.handle.net/10353/11586 , vital:39087
- Description: The current interest in zero tillage/no-till technologies is a result of the need to reduce excessive land degradation in most crop producing areas as well as to enhance sustainable food production. Farmers are always looking for ways to increase yields and profits and zero-tillage may be a way to achieve this goal. However, a systematic comparative study of the performance of zero-tillage and conventional tillage within the former homeland areas of the Eastern Cape Province is lacking. The broad objective of the study is to comparatively analyze zero tillage and conventional tillage and to determine which practice is more beneficial for the land and farmers in the area. Specifically, the study investigated the relative performance of Zero-tillage and conventional–tillage in terms of quantity produced per farm and per hectare, factors influencing the adoption rate of zero tillage and conventional tillage and to determine the relative impact of zero-tillage and conventional tillage on household income. The study was carried out in Amahlathi Local Municipality in the Eastern Cape Province and employed survey data obtained from 100 respondents using conventional tillage and zero tillage farmers growing spinach, cabbage, beetroot, maize, and potatoes. The study employed a cross-sectional research design. A multistage stratified sampling procedure was used in which the first stage involved selecting respondents from Amahlathi Local Municipally. This was followed by the selection of villages and then the respondents. This was done through stratification of smallholder farmers from the different Villages. This was followed by random sampling which was used to get the sample size for the study. Stata and SPSS were used to analyze the data. Descriptive statistics was used to examine current farming practices in the Eastern Cape Province while Propensity Score Matching was employed to estimate the factors that had an impact on zero tillage adoption as well as the relative impact of zero tillage and conventional tillage on household income. Gross margin analysis was used to estimate profitability of zero tillage and conventional. female farmers are participating more in zero tillage with 63.8percent while males are dominating the conventional tillage with 51.6percent. These results show that females play a crucial role in decision making when it comes to agriculture and adoption of new agricultural technologies. The majority of the farmers involved in the study were young farmers with 58percent from zero tillage and 42percent practically involved in conventional tillage. Moreover, the study showed that 41percent of the respondents practising ZT were married, and about 39percent of the respondents practising conventional tillage were married. The marital status of the respondents suggested that zero-tillage farmers were relatively stable in their farming activities as compared to conventional tillage. The results presented that 52.2percent of the respondents who practised zero tillage were better educated than the 48.4percent of the respondents practising conventional tillage. The respondents that were specialising in zero-tillage, about 41% relied on farming, 6% relied on salaried income and 54percent relied on social grants. On the other hand, respondents that were specialising in conventional tillage about, 26percent relied on farming, 16percent relied on salaried income, while 58percent relied on social grants. The respondents that were specialising in zero-tillage, about 28percent used communal land, 1percent used own land and 71percent used family land. On the other hand, respondents that were specialising in conventional tillage about, 42percent used communal land, 7percent use own land and 52percent used family land. The average household size for both groups of farmers is 5 people per household. Household income distribution for conventional tillage is giving the farmers an average of R3187.10 income while the zero tillage is giving them an income of R2305.80 on average. The study revealed that the landholdings for conventional tillage agriculture tend to be more (1.77 ha) compared to zero tillage (0.79 ha) agriculture. The Propensity Score Matching results indicated that participation in smallholder zero tillage farming contributes to household income. This implies that participating in zero tillage farming can contribute to rural livelihoods, increased income and production yields. The study results showed that households chose different farming systems based on their knowledge, level of education and farming experiences. The gross margin results show that conventional tillage farming households generated more income than zero tillage farming households. Farmers who were involved in conventional tillage farming were complaining that yields and income have decreased with time and they are continuing to decrease while farmers who carried out zero tillage farming indicated that their yields and income have improved considerably and continue to increase with time. Thus, support for adopting and implementing zero tillage practices can be an important factor for improving incomes for rural households. Based on the findings highlighted above, the study recommends provision of farm inputs and continuation of government support with more emphasis on strengthening access to inputs and technical assistance. There is a need for support programmes that would help to motivate farmers for better performance. The programmes include infrastructure developments, research and extension activities.
- Full Text:
- Date Issued: 2017
- Authors: Gomo, Zintle
- Date: 2017
- Subjects: Tillage--South Africa--Eastern Cape Farms, Small--South Africa--Eastern Cape No-tillage--South Africa--Eastern Cape
- Language: English
- Type: Thesis , Masters , Agricultural Economics
- Identifier: http://hdl.handle.net/10353/11586 , vital:39087
- Description: The current interest in zero tillage/no-till technologies is a result of the need to reduce excessive land degradation in most crop producing areas as well as to enhance sustainable food production. Farmers are always looking for ways to increase yields and profits and zero-tillage may be a way to achieve this goal. However, a systematic comparative study of the performance of zero-tillage and conventional tillage within the former homeland areas of the Eastern Cape Province is lacking. The broad objective of the study is to comparatively analyze zero tillage and conventional tillage and to determine which practice is more beneficial for the land and farmers in the area. Specifically, the study investigated the relative performance of Zero-tillage and conventional–tillage in terms of quantity produced per farm and per hectare, factors influencing the adoption rate of zero tillage and conventional tillage and to determine the relative impact of zero-tillage and conventional tillage on household income. The study was carried out in Amahlathi Local Municipality in the Eastern Cape Province and employed survey data obtained from 100 respondents using conventional tillage and zero tillage farmers growing spinach, cabbage, beetroot, maize, and potatoes. The study employed a cross-sectional research design. A multistage stratified sampling procedure was used in which the first stage involved selecting respondents from Amahlathi Local Municipally. This was followed by the selection of villages and then the respondents. This was done through stratification of smallholder farmers from the different Villages. This was followed by random sampling which was used to get the sample size for the study. Stata and SPSS were used to analyze the data. Descriptive statistics was used to examine current farming practices in the Eastern Cape Province while Propensity Score Matching was employed to estimate the factors that had an impact on zero tillage adoption as well as the relative impact of zero tillage and conventional tillage on household income. Gross margin analysis was used to estimate profitability of zero tillage and conventional. female farmers are participating more in zero tillage with 63.8percent while males are dominating the conventional tillage with 51.6percent. These results show that females play a crucial role in decision making when it comes to agriculture and adoption of new agricultural technologies. The majority of the farmers involved in the study were young farmers with 58percent from zero tillage and 42percent practically involved in conventional tillage. Moreover, the study showed that 41percent of the respondents practising ZT were married, and about 39percent of the respondents practising conventional tillage were married. The marital status of the respondents suggested that zero-tillage farmers were relatively stable in their farming activities as compared to conventional tillage. The results presented that 52.2percent of the respondents who practised zero tillage were better educated than the 48.4percent of the respondents practising conventional tillage. The respondents that were specialising in zero-tillage, about 41% relied on farming, 6% relied on salaried income and 54percent relied on social grants. On the other hand, respondents that were specialising in conventional tillage about, 26percent relied on farming, 16percent relied on salaried income, while 58percent relied on social grants. The respondents that were specialising in zero-tillage, about 28percent used communal land, 1percent used own land and 71percent used family land. On the other hand, respondents that were specialising in conventional tillage about, 42percent used communal land, 7percent use own land and 52percent used family land. The average household size for both groups of farmers is 5 people per household. Household income distribution for conventional tillage is giving the farmers an average of R3187.10 income while the zero tillage is giving them an income of R2305.80 on average. The study revealed that the landholdings for conventional tillage agriculture tend to be more (1.77 ha) compared to zero tillage (0.79 ha) agriculture. The Propensity Score Matching results indicated that participation in smallholder zero tillage farming contributes to household income. This implies that participating in zero tillage farming can contribute to rural livelihoods, increased income and production yields. The study results showed that households chose different farming systems based on their knowledge, level of education and farming experiences. The gross margin results show that conventional tillage farming households generated more income than zero tillage farming households. Farmers who were involved in conventional tillage farming were complaining that yields and income have decreased with time and they are continuing to decrease while farmers who carried out zero tillage farming indicated that their yields and income have improved considerably and continue to increase with time. Thus, support for adopting and implementing zero tillage practices can be an important factor for improving incomes for rural households. Based on the findings highlighted above, the study recommends provision of farm inputs and continuation of government support with more emphasis on strengthening access to inputs and technical assistance. There is a need for support programmes that would help to motivate farmers for better performance. The programmes include infrastructure developments, research and extension activities.
- Full Text:
- Date Issued: 2017
Comparative fish ecology in three periodically connected rivers in the upper Zambezi and Okavango ecoregions
- Authors: Taylor, Geraldine Claire
- Date: 2017
- Subjects: Fishes Ecology Zambia Zambezi District , Floodplain ecology Zambia Zambezi District , Stable isotopes , Fishes Food Zambia Zambezi District , Fishes Mortality Zambia Zambezi District , Fish populations Zambia Zambezi District , Fishes Growth
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/65055 , vital:28660 , DOI https://doi.org/10.21504/10962/65055
- Description: The Upper Zambezi, Kavango and Kwando rivers are three periodically interlinked floodplain rivers which share the same Upper Zambezian floodplain ichthyofauna. The aim of this thesis was to compare the biology and ecology of the fish communities in these three rivers. The objective was to test the hypothesis that fish community composition and assemblage structure, fish diets, food web structure and trophic dynamics, fish growth rates and total mortality are influenced by the differing flood magnitudes of the three rivers, in support of the flood pulse concept. To understand the abiotic characteristics of each river, water temperature, flood regime, total dissolved inorganic nitrogen concentrations and water quality parameters were measured and compared between rivers. Water temperatures varied seasonally, and seven day moving averages peaked above 30 °C in January, and fell to between 16 and 19 °C in June. The Zambezi River had the largest flood (6.14 m), followed by the Kavango River (3.80 m), while the Kwando River had the smallest flood (0.65 m). Total dissolved inorganic nitrogen concentrations were low in the Kavango and Zambezi Rivers (0.2 - 0.6 mg/l), and slightly higher in the Kwando River (<1 mg/l). Conductivity, total dissolved solids and total dissolved inorganic nitrogen concentrations decreased with the flood (dilution effect). Using biomass catch per unit effort data from experimental gillnets, fish community composition and assemblage structure was described, and differed between rivers in all hydrological seasons. In the Zambezi and Kavango rivers, fish assemblages varied with hydrological season as a result of the homogenising influence of the flood pulse, while in the Kwando River fish assemblages did not differ seasonally as flood pulses were small and often irregular. Differences in community composition were attributed to the abundance of Hydrocynus vittatus, a large bodied open water predator, in the Zambezi and Kavango rivers, and its relative absence in the Kwando River. Based on the results of the community composition, six focus species were chosen that were abundant and representative of the various feeding modes and life history strategies of the fish community. These were the striped robber Brycinus lateralis, sharptooth catfish Clarias gariepinus, blunttooth catfish Clarias ngamensis, African pike Hepsetus cuvieri, silver catfish Schilbe intermedius and purpleface largemouth Serranochromis macrocephalus. Stomach contents analysis was then used to compare the feeding ecology of the six example species between rivers. Clarias gariepinus, C. ngamensis and S. intermedius were piscivorous in the Zambezi and Kavango rivers, and preyed upon more invertebrates in the Kwando River, while Hepsetus cuvieri and S. macrocephalus were piscivorous in all three rivers. Differences in diets were attributed to seasonal prey abundance, with prey fishes abundant during falling and low water when the Zambezi and Kavango rivers were sampled, while invertebrates were abundant during rising and high water when the Kwando River was sampled. Prey mastication by B. lateralis made prey identification difficult. For other predators, the usefulness of stomach contents analysis for dietary descriptions was restricted by the high proportion of empty stomachs. As a result, whole ecosystem stable isotope analysis was used to gain a holistic understanding of the food web structure and fish feeding ecology of the three rivers. The Zambezi and Kavango river food webs were supported by C enriched resources such as C4 and C3 riparian vegetation from the floodplain, while the Kwando River food web was based on C depleted resources such as filamentous algae and aquatic macrophytes. The Zambezi River food web had a restricted nitrogen range, with reduced food chain length and the predators in this river did not occupy such elevated trophic positions compared to in the Kavango and Kwando river food webs. This was attributed to the overfishing of the primary and tertiary consumers in the Zambezi River, a phenomenon known to reduce food chain length. Focussing on predator communities, in the Zambezi and Kavango rivers, H. vittatus isotopic niche width was large and overlapped significantly with most other predators, while in the Kwando River predator niches were more distinct. This supported previously proposed hypotheses by describing H. vittatus as a dominant predator which excludes all other fishes by predation or competition. Despite the dominance of H. vittatus, C. gariepinus occupied the position of top predator in all three rivers, and information on the habitat use, feeding habits and trophic niches of the serranochromine cichlids added understanding of their ecology. Lastly, age was determined using sectioned sagittal otoliths for C. gariepinus, C. ngamensis, S. intermedius and S. macrocephalus and using whole asteriscus otoliths for B. lateralis and H. cuvieri, and growth was modelled using the von Bertalanffy growth equation. Growth performance was high in the Zambezi and Kavango rivers, and lower in the Kwando River, most likely in response to the varying flood magnitudes. Total mortality rates, estimated using Hoenig’s maximum-age based equation, were high in the Zambezi River as a result of the high fishing pressure on this river. Overall floodplain fish ecology in the Zambezi, Kavango and Kwando rivers was influenced by the flood pulse, as was predicted by the flood pulse concept. Periodic and equilibrium life history strategists were found to adapt either to the pulsing environments of the Zambezi and Kavango rivers, or to the more stable environment of the Kwando River, and large bodied, long lived periodic strategists such as C. gariepinus tended to be highly plastic and able to thrive in most conditions. Data also suggested that Zambezi River food web structure and fish mortality rates have been impacted by overfishing, for which more information is needed to conserve and manage this system. , Thesis (PhD) -- Faculty of Science, Ichthyology and Fisheries Science, 2018
- Full Text:
- Date Issued: 2017
- Authors: Taylor, Geraldine Claire
- Date: 2017
- Subjects: Fishes Ecology Zambia Zambezi District , Floodplain ecology Zambia Zambezi District , Stable isotopes , Fishes Food Zambia Zambezi District , Fishes Mortality Zambia Zambezi District , Fish populations Zambia Zambezi District , Fishes Growth
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/65055 , vital:28660 , DOI https://doi.org/10.21504/10962/65055
- Description: The Upper Zambezi, Kavango and Kwando rivers are three periodically interlinked floodplain rivers which share the same Upper Zambezian floodplain ichthyofauna. The aim of this thesis was to compare the biology and ecology of the fish communities in these three rivers. The objective was to test the hypothesis that fish community composition and assemblage structure, fish diets, food web structure and trophic dynamics, fish growth rates and total mortality are influenced by the differing flood magnitudes of the three rivers, in support of the flood pulse concept. To understand the abiotic characteristics of each river, water temperature, flood regime, total dissolved inorganic nitrogen concentrations and water quality parameters were measured and compared between rivers. Water temperatures varied seasonally, and seven day moving averages peaked above 30 °C in January, and fell to between 16 and 19 °C in June. The Zambezi River had the largest flood (6.14 m), followed by the Kavango River (3.80 m), while the Kwando River had the smallest flood (0.65 m). Total dissolved inorganic nitrogen concentrations were low in the Kavango and Zambezi Rivers (0.2 - 0.6 mg/l), and slightly higher in the Kwando River (<1 mg/l). Conductivity, total dissolved solids and total dissolved inorganic nitrogen concentrations decreased with the flood (dilution effect). Using biomass catch per unit effort data from experimental gillnets, fish community composition and assemblage structure was described, and differed between rivers in all hydrological seasons. In the Zambezi and Kavango rivers, fish assemblages varied with hydrological season as a result of the homogenising influence of the flood pulse, while in the Kwando River fish assemblages did not differ seasonally as flood pulses were small and often irregular. Differences in community composition were attributed to the abundance of Hydrocynus vittatus, a large bodied open water predator, in the Zambezi and Kavango rivers, and its relative absence in the Kwando River. Based on the results of the community composition, six focus species were chosen that were abundant and representative of the various feeding modes and life history strategies of the fish community. These were the striped robber Brycinus lateralis, sharptooth catfish Clarias gariepinus, blunttooth catfish Clarias ngamensis, African pike Hepsetus cuvieri, silver catfish Schilbe intermedius and purpleface largemouth Serranochromis macrocephalus. Stomach contents analysis was then used to compare the feeding ecology of the six example species between rivers. Clarias gariepinus, C. ngamensis and S. intermedius were piscivorous in the Zambezi and Kavango rivers, and preyed upon more invertebrates in the Kwando River, while Hepsetus cuvieri and S. macrocephalus were piscivorous in all three rivers. Differences in diets were attributed to seasonal prey abundance, with prey fishes abundant during falling and low water when the Zambezi and Kavango rivers were sampled, while invertebrates were abundant during rising and high water when the Kwando River was sampled. Prey mastication by B. lateralis made prey identification difficult. For other predators, the usefulness of stomach contents analysis for dietary descriptions was restricted by the high proportion of empty stomachs. As a result, whole ecosystem stable isotope analysis was used to gain a holistic understanding of the food web structure and fish feeding ecology of the three rivers. The Zambezi and Kavango river food webs were supported by C enriched resources such as C4 and C3 riparian vegetation from the floodplain, while the Kwando River food web was based on C depleted resources such as filamentous algae and aquatic macrophytes. The Zambezi River food web had a restricted nitrogen range, with reduced food chain length and the predators in this river did not occupy such elevated trophic positions compared to in the Kavango and Kwando river food webs. This was attributed to the overfishing of the primary and tertiary consumers in the Zambezi River, a phenomenon known to reduce food chain length. Focussing on predator communities, in the Zambezi and Kavango rivers, H. vittatus isotopic niche width was large and overlapped significantly with most other predators, while in the Kwando River predator niches were more distinct. This supported previously proposed hypotheses by describing H. vittatus as a dominant predator which excludes all other fishes by predation or competition. Despite the dominance of H. vittatus, C. gariepinus occupied the position of top predator in all three rivers, and information on the habitat use, feeding habits and trophic niches of the serranochromine cichlids added understanding of their ecology. Lastly, age was determined using sectioned sagittal otoliths for C. gariepinus, C. ngamensis, S. intermedius and S. macrocephalus and using whole asteriscus otoliths for B. lateralis and H. cuvieri, and growth was modelled using the von Bertalanffy growth equation. Growth performance was high in the Zambezi and Kavango rivers, and lower in the Kwando River, most likely in response to the varying flood magnitudes. Total mortality rates, estimated using Hoenig’s maximum-age based equation, were high in the Zambezi River as a result of the high fishing pressure on this river. Overall floodplain fish ecology in the Zambezi, Kavango and Kwando rivers was influenced by the flood pulse, as was predicted by the flood pulse concept. Periodic and equilibrium life history strategists were found to adapt either to the pulsing environments of the Zambezi and Kavango rivers, or to the more stable environment of the Kwando River, and large bodied, long lived periodic strategists such as C. gariepinus tended to be highly plastic and able to thrive in most conditions. Data also suggested that Zambezi River food web structure and fish mortality rates have been impacted by overfishing, for which more information is needed to conserve and manage this system. , Thesis (PhD) -- Faculty of Science, Ichthyology and Fisheries Science, 2018
- Full Text:
- Date Issued: 2017
Comparative localization studies of P.falciparum ADP-ribosylation factor proteins in P.falciparum parasites and hela cells using GFP tagged constructs
- Authors: Swart, Tarryn
- Date: 2017
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/3537 , vital:20519
- Description: Expected release date-December 2018
- Full Text:
- Date Issued: 2017
- Authors: Swart, Tarryn
- Date: 2017
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/3537 , vital:20519
- Description: Expected release date-December 2018
- Full Text:
- Date Issued: 2017
Comparative perch selection in Southern Fiscal Lanius collaris and Fiscal Flycatcher Sigelus silens at Amakhala Game Reserve, South Africa
- Daniels, Ryan J, Hulley, Patrick E, Craig, Adrian J F K
- Authors: Daniels, Ryan J , Hulley, Patrick E , Craig, Adrian J F K
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/449294 , vital:74809 , https://doi.org/10.2989/00306525.2016.1264496
- Description: The Southern Fiscal Lanius collaris and the Fiscal Flycatcher Sigelus silens are common, widespread and sympatric in much of southern Africa. They are similar in plumage and ecology, which may predispose them to competition and interspecific territorial aggression but this has not been tested to date. Here we tested for evidence of competition for perch space. At Amakhala Private Game Reserve, Eastern Cape, South Africa we monitored the occurrence and perch use of both species along transects. The birds do co-occur locally but there is evidence of small-scale spatial separation possibly a result of interspecific territoriality. Perch selection differed in respect of perch type but not perch height. Both species perched prominently in the majority of observations. Southern Fiscals make greater use of Searsia and Gymnosporia trees, whereas the Fiscal Flycatcher makes near-equal use of Vachellia karroo, Searsia and Gymnosporia trees. This may be an example of niche partitioning, though it remains unclear whether the birds actively compete for perch space, or if the separation is a product of different perch preferences, territoriality and the local plant community.
- Full Text:
- Date Issued: 2017
- Authors: Daniels, Ryan J , Hulley, Patrick E , Craig, Adrian J F K
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/449294 , vital:74809 , https://doi.org/10.2989/00306525.2016.1264496
- Description: The Southern Fiscal Lanius collaris and the Fiscal Flycatcher Sigelus silens are common, widespread and sympatric in much of southern Africa. They are similar in plumage and ecology, which may predispose them to competition and interspecific territorial aggression but this has not been tested to date. Here we tested for evidence of competition for perch space. At Amakhala Private Game Reserve, Eastern Cape, South Africa we monitored the occurrence and perch use of both species along transects. The birds do co-occur locally but there is evidence of small-scale spatial separation possibly a result of interspecific territoriality. Perch selection differed in respect of perch type but not perch height. Both species perched prominently in the majority of observations. Southern Fiscals make greater use of Searsia and Gymnosporia trees, whereas the Fiscal Flycatcher makes near-equal use of Vachellia karroo, Searsia and Gymnosporia trees. This may be an example of niche partitioning, though it remains unclear whether the birds actively compete for perch space, or if the separation is a product of different perch preferences, territoriality and the local plant community.
- Full Text:
- Date Issued: 2017
Comparative performance of natural and synthetic fibre nonwoven geotextiles
- Tshifularo, Cyrus Alushavhiwi
- Authors: Tshifularo, Cyrus Alushavhiwi
- Date: 2017
- Subjects: Geotextiles Textile fabrics , Textile fibers -- Testing Textile industry -- Quality control
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/21362 , vital:29504
- Description: The aim of this work was to establish a range of suitable process parameters which can be utilized to produce needlepunched nonwoven fabrics for geotextile applications. Nonwoven fabrics were produced from 100% PP, a blend of 50/50% PP/kenaf and 100% kenaf fibres. The depths of needle penetration of 4, 7 and 10 mm, stroke frequencies of 250, 350 and 450 strokes/min and mass per unit area of 300, 600 and 900 g/m2 were utilized for producing the fabrics, on a Dilo loom. The effect of depth of needle penetration, stroke frequency and mass per unit area on the fabric properties, namely, tensile strength, puncture resistance, pore size, water permeability and transmissivity were analysed. In addition, the effect of chemicals, namely, 10% ammonium hydroxide (NH4OH), 10% sodium chloride (NaCl) and 3% sulphuric acid (H2SO4) solutions on degradation of the fabric was also studied. The results have shown that density, thickness and nominal weight of the needlepunched nonwoven fabrics were related to each other and they were influenced by stroke frequency, depth of needle penetration and feed rate of the needlepunching process. The increase in nominal weight of the fabrics also increases thickness and density of the fabrics. The tensile strength and puncture resistance of the fabrics increased with the increases in stroke frequency, depth of needle penetration and fabric mass per unit area. However, lower tensile strength and puncture resistance were achieved in the fabrics produced at lower stroke frequency, lower depth of needle penetration and lower mass per unit area. Bigger pores were resulted in the fabrics produced at lower stroke frequency, lower depth of needle penetration and lower mass per unit area, however, pore size decreased with increases in stroke frequency, depth of needle penetration and mass per unit area. Water permeability depends on the pore size, properties of the fibres, stroke frequency, depth of needle penetration and mass per unit area. Higher tensile strength and higher puncture resistance were achieved in the needlepunched nonwoven fabrics produced from 100% PP fibres, therefore, they are suitable for some load-bearing geotextile applications, such as reinforcement and separation. However, higher water permeability was achieved in the fabrics produced from 100% kenaf fibres, therefore, they are ideal for geotextile applications where good water permeability is required. Higher values for transmissivity were obtained in the fabrics produced from a blend of 50/50% PP/kenaf fibres, therefore they are suitable for drainage applications. The fabrics produced from a blend of 50/50% PP/kenaf fibres achieved better values of tensile strength, puncture resistance, pore size and water permeability in comparison to that produced from 100% PP and 100% kenaf fibres. However, better tensile strength and puncture resistance were achieved in the fabrics produced from 100% PP fibres and bigger pore size and higher water permeability were achieved in the fabrics produced from 100% kenaf fibres. Therefore, it can be suggested that the nonwoven fabrics produced from a blend of 50/50% PP/kenaf fibres can fulfil almost all requirements of geotextile applications, such as, filtration, separation, reinforcement and drainage. The fabrics produced from 100% PP fibres were not damaged or deteriorated when treated with all the three chemicals due to chemical inertness of polypropylene. However, the fabrics produced from a blend of 50/50% PP/kenaf and 100% kenaf fibres were damaged and deteriorated when treated with H2SO4.
- Full Text:
- Date Issued: 2017
- Authors: Tshifularo, Cyrus Alushavhiwi
- Date: 2017
- Subjects: Geotextiles Textile fabrics , Textile fibers -- Testing Textile industry -- Quality control
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/21362 , vital:29504
- Description: The aim of this work was to establish a range of suitable process parameters which can be utilized to produce needlepunched nonwoven fabrics for geotextile applications. Nonwoven fabrics were produced from 100% PP, a blend of 50/50% PP/kenaf and 100% kenaf fibres. The depths of needle penetration of 4, 7 and 10 mm, stroke frequencies of 250, 350 and 450 strokes/min and mass per unit area of 300, 600 and 900 g/m2 were utilized for producing the fabrics, on a Dilo loom. The effect of depth of needle penetration, stroke frequency and mass per unit area on the fabric properties, namely, tensile strength, puncture resistance, pore size, water permeability and transmissivity were analysed. In addition, the effect of chemicals, namely, 10% ammonium hydroxide (NH4OH), 10% sodium chloride (NaCl) and 3% sulphuric acid (H2SO4) solutions on degradation of the fabric was also studied. The results have shown that density, thickness and nominal weight of the needlepunched nonwoven fabrics were related to each other and they were influenced by stroke frequency, depth of needle penetration and feed rate of the needlepunching process. The increase in nominal weight of the fabrics also increases thickness and density of the fabrics. The tensile strength and puncture resistance of the fabrics increased with the increases in stroke frequency, depth of needle penetration and fabric mass per unit area. However, lower tensile strength and puncture resistance were achieved in the fabrics produced at lower stroke frequency, lower depth of needle penetration and lower mass per unit area. Bigger pores were resulted in the fabrics produced at lower stroke frequency, lower depth of needle penetration and lower mass per unit area, however, pore size decreased with increases in stroke frequency, depth of needle penetration and mass per unit area. Water permeability depends on the pore size, properties of the fibres, stroke frequency, depth of needle penetration and mass per unit area. Higher tensile strength and higher puncture resistance were achieved in the needlepunched nonwoven fabrics produced from 100% PP fibres, therefore, they are suitable for some load-bearing geotextile applications, such as reinforcement and separation. However, higher water permeability was achieved in the fabrics produced from 100% kenaf fibres, therefore, they are ideal for geotextile applications where good water permeability is required. Higher values for transmissivity were obtained in the fabrics produced from a blend of 50/50% PP/kenaf fibres, therefore they are suitable for drainage applications. The fabrics produced from a blend of 50/50% PP/kenaf fibres achieved better values of tensile strength, puncture resistance, pore size and water permeability in comparison to that produced from 100% PP and 100% kenaf fibres. However, better tensile strength and puncture resistance were achieved in the fabrics produced from 100% PP fibres and bigger pore size and higher water permeability were achieved in the fabrics produced from 100% kenaf fibres. Therefore, it can be suggested that the nonwoven fabrics produced from a blend of 50/50% PP/kenaf fibres can fulfil almost all requirements of geotextile applications, such as, filtration, separation, reinforcement and drainage. The fabrics produced from 100% PP fibres were not damaged or deteriorated when treated with all the three chemicals due to chemical inertness of polypropylene. However, the fabrics produced from a blend of 50/50% PP/kenaf and 100% kenaf fibres were damaged and deteriorated when treated with H2SO4.
- Full Text:
- Date Issued: 2017
Comparative studies of different ant-hypertensive treatments used for cardiovascular disease patients : a case study of public health facility in the Eastern Cape South Africa
- Abiodun, Oluwatoyin Victoria
- Authors: Abiodun, Oluwatoyin Victoria
- Date: 2017
- Subjects: Survival analysis (Biometry) Cardiovascular system -- Diseases
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/13205 , vital:39519
- Description: Discovery has shown that many deaths arising from cardiovascular disease often show early symptoms of high blood pressure, which makes it the leading risk factor of cardiovascular diseases. There is a distressing rate of 970 million hypertensive patients worldwide, a higher ratio of 640 million are from developing countries, if proper measures are not taken, there will be a higher growth of cardiovascular disease in adults by 2025. The focus of this study was to compare the therapeutic potentials of the anti-hypertensive therapies, drug A (amiloride + furosemide) and drug B (hydrochlorothiazide + enalapril) used in the treatment of cardiovascular disease patients for their capability to lengthen remission duration and survival time. All patients were diagnosed with a type of cardiovascular disorder, therefore patient records were followed up and blood pressure was being monitored for a period of two years. The retrospective data gotten from the public health facility was analysed using survival analysis methods. The results revealed that there was no statistical significance in the distributions of the length of remission and survival time of drug A and drug B patients. Also, in the age category, CVD patients that are 55 and above recover faster with drug A, while CVD patients below 55 shows a better survival with drug B. Then again, estimates from the gender category show a better survival in males using drug A, while the females thrive slightly better using drug B. Among all the risk factors considered in the study, only employment status showed a strong impact on survival time (remission). The findings from this study may help to formulate interventions and strategies that will increase the lifespan of cardiovascular patients and reduce early mortality due to cardiovascular diseases.
- Full Text:
- Date Issued: 2017
- Authors: Abiodun, Oluwatoyin Victoria
- Date: 2017
- Subjects: Survival analysis (Biometry) Cardiovascular system -- Diseases
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/13205 , vital:39519
- Description: Discovery has shown that many deaths arising from cardiovascular disease often show early symptoms of high blood pressure, which makes it the leading risk factor of cardiovascular diseases. There is a distressing rate of 970 million hypertensive patients worldwide, a higher ratio of 640 million are from developing countries, if proper measures are not taken, there will be a higher growth of cardiovascular disease in adults by 2025. The focus of this study was to compare the therapeutic potentials of the anti-hypertensive therapies, drug A (amiloride + furosemide) and drug B (hydrochlorothiazide + enalapril) used in the treatment of cardiovascular disease patients for their capability to lengthen remission duration and survival time. All patients were diagnosed with a type of cardiovascular disorder, therefore patient records were followed up and blood pressure was being monitored for a period of two years. The retrospective data gotten from the public health facility was analysed using survival analysis methods. The results revealed that there was no statistical significance in the distributions of the length of remission and survival time of drug A and drug B patients. Also, in the age category, CVD patients that are 55 and above recover faster with drug A, while CVD patients below 55 shows a better survival with drug B. Then again, estimates from the gender category show a better survival in males using drug A, while the females thrive slightly better using drug B. Among all the risk factors considered in the study, only employment status showed a strong impact on survival time (remission). The findings from this study may help to formulate interventions and strategies that will increase the lifespan of cardiovascular patients and reduce early mortality due to cardiovascular diseases.
- Full Text:
- Date Issued: 2017
Comparing the automotive industry manufacturing costs between East London, Uitenhage and Gaborone
- Authors: Domingo, Steve Cecil
- Date: 2017
- Subjects: Manufactures -- Costs Manufacturing industries -- South Africa -- Eastern Cape , Manufacturing industries -- Botswana -- Gaborone Automobile industry and trade -- South Africa -- Eastern Cape Automobile industry and trade -- Botswana -- Gaborone
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10948/46306 , vital:39545
- Description: South Africa faces the problem of its automotive production facilities, threatening relocation from South Africa to neighbouring countries such as Botswana, Nigeria and Mozambique, this while, the South African manufacturing industry suffers a very high unemployment rate. The business models for South African automotive manufacturing industry is currently too cost inefficient, making relocation to neighbouring countries more feasible and attractive. The purpose of this research study is to conduct an “Automotive Manufacturing Costs comparison between East London, Uitenhage, Gaborone and the resultant impact on the South African employment of manufacturing staff” The primary objective of this study is to measure the manufacturing cost between East London, Uitenhage and Gaborone (Botswana) for one automotive component and explain if this can affect employment at the current costs of labour. The findings might add value to the South African working population about the serious impact and effect of the high cost of labour in the country. A literature review was conducted on the South African and Botswana automotive manufacturing industry, the economic development and the strategic challenges of the two countries. In conclusion, the relocation of the production industry, specifically the South African market relocating to broader Africa. In order to achieve the research objectives, personal interviews with senior managers (Plant Managers, Business Managers and Human Resources Managers) of firms that have been involved in projects of the relocation of firms into Africa was conducted. The aim of the study is to identify to the local automotive manufacturing industry, unions, government and business people that the current labour cost is South Africa could cause future relocation of industry from South Africa which will cause more unemployment.
- Full Text:
- Date Issued: 2017
- Authors: Domingo, Steve Cecil
- Date: 2017
- Subjects: Manufactures -- Costs Manufacturing industries -- South Africa -- Eastern Cape , Manufacturing industries -- Botswana -- Gaborone Automobile industry and trade -- South Africa -- Eastern Cape Automobile industry and trade -- Botswana -- Gaborone
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10948/46306 , vital:39545
- Description: South Africa faces the problem of its automotive production facilities, threatening relocation from South Africa to neighbouring countries such as Botswana, Nigeria and Mozambique, this while, the South African manufacturing industry suffers a very high unemployment rate. The business models for South African automotive manufacturing industry is currently too cost inefficient, making relocation to neighbouring countries more feasible and attractive. The purpose of this research study is to conduct an “Automotive Manufacturing Costs comparison between East London, Uitenhage, Gaborone and the resultant impact on the South African employment of manufacturing staff” The primary objective of this study is to measure the manufacturing cost between East London, Uitenhage and Gaborone (Botswana) for one automotive component and explain if this can affect employment at the current costs of labour. The findings might add value to the South African working population about the serious impact and effect of the high cost of labour in the country. A literature review was conducted on the South African and Botswana automotive manufacturing industry, the economic development and the strategic challenges of the two countries. In conclusion, the relocation of the production industry, specifically the South African market relocating to broader Africa. In order to achieve the research objectives, personal interviews with senior managers (Plant Managers, Business Managers and Human Resources Managers) of firms that have been involved in projects of the relocation of firms into Africa was conducted. The aim of the study is to identify to the local automotive manufacturing industry, unions, government and business people that the current labour cost is South Africa could cause future relocation of industry from South Africa which will cause more unemployment.
- Full Text:
- Date Issued: 2017
Comparing the fish assemblages and food web structures of large floodplain rivers
- Taylor, Geraldine C, Weyl, Olaf L F, Hill, Jaclyn M, Peel, Richard A, Hay, Clinton J
- Authors: Taylor, Geraldine C , Weyl, Olaf L F , Hill, Jaclyn M , Peel, Richard A , Hay, Clinton J
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68961 , vital:29343 , https://doi.org/10.1111/fwb.13032
- Description: The Upper Zambezi, Kavango and Kwando are large floodplain rivers with substantial biodiversity, providing water and ecosystem services to a large tract of southern Africa. These rivers differ in hydrological regime. The Upper Zambezi and Kavango rivers are in flood for 4 months (March, April, May, June) while, in the Kwando River, floods are later and last for 1–2 months in July and August. The Upper Zambezi River has the largest annual flood pulse, followed by the Kavango River, while the Kwando River experiences small and unreliable floods. During years of exceptional flooding of the Upper Zambezi and Kavango rivers, the rivers are interconnected at peak flows and therefore share a common ichthyofauna. This provided a natural experiment to investigate the responses of fish communities comprised of the same species to differing flood regimes by comparing the fish assemblages and food‐web structures between rivers.
- Full Text: false
- Date Issued: 2017
- Authors: Taylor, Geraldine C , Weyl, Olaf L F , Hill, Jaclyn M , Peel, Richard A , Hay, Clinton J
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68961 , vital:29343 , https://doi.org/10.1111/fwb.13032
- Description: The Upper Zambezi, Kavango and Kwando are large floodplain rivers with substantial biodiversity, providing water and ecosystem services to a large tract of southern Africa. These rivers differ in hydrological regime. The Upper Zambezi and Kavango rivers are in flood for 4 months (March, April, May, June) while, in the Kwando River, floods are later and last for 1–2 months in July and August. The Upper Zambezi River has the largest annual flood pulse, followed by the Kavango River, while the Kwando River experiences small and unreliable floods. During years of exceptional flooding of the Upper Zambezi and Kavango rivers, the rivers are interconnected at peak flows and therefore share a common ichthyofauna. This provided a natural experiment to investigate the responses of fish communities comprised of the same species to differing flood regimes by comparing the fish assemblages and food‐web structures between rivers.
- Full Text: false
- Date Issued: 2017
Comparison of taxation reforms regarding retirement funding between South Africa and the United Kingdom
- Authors: Kruger, Leander
- Date: 2017
- Subjects: Pension trusts -- Law and legislation -- South Africa Pension trusts -- Law and legislation -- Great Britain , Taxation -- Law and legislation -- South Africa Taxation -- Law and legislation -- Great Britain Pensions -- Law and legislation -- South Africa Pensions -- Law and legislation -- Great Britain
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: http://hdl.handle.net/10948/18200 , vital:28588
- Description: The purpose of this study was to review the provision of public and private retirement funding in both South Africa and the United Kingdom and the role of taxation in encouraging greater private provision for retirement. The study described the basis of taxation and determination of ‘taxable income’ in each jurisdiction, before addressing the relationship between taxation and retirement funding in each jurisdiction respectively. Both jurisdictions have introduced significant reforms of their systems of retirement funding and these reforms were accordingly addressed in the present research. The study compared the two jurisdictions based on the above mentioned areas to determine similarities or differences. The study concluded with recommendations, these being that South Africa should assess the feasibility of providing greater State provided retirement funding by possibly including a mandatory contribution, such as that used by the UK for its single-tier flat rate New State Pension. A further recommendation was that South Africa should encourage greater provision of private retirement funding by considering even greater tax deductions for contributions.
- Full Text:
- Date Issued: 2017
- Authors: Kruger, Leander
- Date: 2017
- Subjects: Pension trusts -- Law and legislation -- South Africa Pension trusts -- Law and legislation -- Great Britain , Taxation -- Law and legislation -- South Africa Taxation -- Law and legislation -- Great Britain Pensions -- Law and legislation -- South Africa Pensions -- Law and legislation -- Great Britain
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: http://hdl.handle.net/10948/18200 , vital:28588
- Description: The purpose of this study was to review the provision of public and private retirement funding in both South Africa and the United Kingdom and the role of taxation in encouraging greater private provision for retirement. The study described the basis of taxation and determination of ‘taxable income’ in each jurisdiction, before addressing the relationship between taxation and retirement funding in each jurisdiction respectively. Both jurisdictions have introduced significant reforms of their systems of retirement funding and these reforms were accordingly addressed in the present research. The study compared the two jurisdictions based on the above mentioned areas to determine similarities or differences. The study concluded with recommendations, these being that South Africa should assess the feasibility of providing greater State provided retirement funding by possibly including a mandatory contribution, such as that used by the UK for its single-tier flat rate New State Pension. A further recommendation was that South Africa should encourage greater provision of private retirement funding by considering even greater tax deductions for contributions.
- Full Text:
- Date Issued: 2017
Competition factors influencing client switching behaviour within the commercial banking industry
- Authors: Mathiyase, Kholiswa
- Date: 2017
- Subjects: Banks and banking -- South Africa , Competition -- South Africa , Financial services industry -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10948/45366 , vital:38574
- Description: Banks are faced with challenges of retaining clients and preventing them from switching to competitors. For many years the South African banking industry has been dominated by the big four banks that were not known to be client focused. The banks were also known for serving only the middle and high-income earners, with the banks having a high and non-transparent banking fee structure. As a result, Capitec Bank was established in 2001 and differentiated itself from the traditional ways of providing banking service. One of their value propositions, Capitec Bank provided low and transparent banking fees, provided a unique personalised service to cater for the unbanked market and is gradually serving the middle and high-income market as well. Capitec Bank managed to establish its presence in the South African banking industry despite the dominance of the big four banks. The banking industry environment has also been subjected to a number of changes, including the entrants of other non-traditional banks, changing client behaviour, technology, regulatory and political reforms and the current depressed economic conditions.
- Full Text:
- Date Issued: 2017
- Authors: Mathiyase, Kholiswa
- Date: 2017
- Subjects: Banks and banking -- South Africa , Competition -- South Africa , Financial services industry -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10948/45366 , vital:38574
- Description: Banks are faced with challenges of retaining clients and preventing them from switching to competitors. For many years the South African banking industry has been dominated by the big four banks that were not known to be client focused. The banks were also known for serving only the middle and high-income earners, with the banks having a high and non-transparent banking fee structure. As a result, Capitec Bank was established in 2001 and differentiated itself from the traditional ways of providing banking service. One of their value propositions, Capitec Bank provided low and transparent banking fees, provided a unique personalised service to cater for the unbanked market and is gradually serving the middle and high-income market as well. Capitec Bank managed to establish its presence in the South African banking industry despite the dominance of the big four banks. The banking industry environment has also been subjected to a number of changes, including the entrants of other non-traditional banks, changing client behaviour, technology, regulatory and political reforms and the current depressed economic conditions.
- Full Text:
- Date Issued: 2017
Composition and fate of triclosan in the sludge from wastewater treatment in Grahamstown, South Africa and Tiaret, Algeria
- Authors: Ncube, Mbonisi
- Date: 2017
- Subjects: Sewage sludge , Sewage Purification South Africa Grahamstown , Sewage Purification Algeria Tiaret , Sewage sludge as fertilizer , Anti-infective agents
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/65156 , vital:28697
- Description: Physicochemical properties such as pH, specific surface area (SSA), cationic exchange capacity (CEC), loss on ignition (LOI), pathogens, plant nutrients (nitrates, ammonium and phosphates), and heavy metals (manganese, copper, lead and cadmium) were determined for sewage sludge from Grahamstown and Tiaret. The values obtained were log transformed thereafter a t-test at 5 % level of significance was used to test for the difference in each parameter for both sludges. The pH of sludge was determined in 1:3 water, 16 water, 1:3 0.01 M calcium chloride and 1:3 1 M potassium chloride. The pH for Grahamstown and Tiaret sludge were in the ranges of 6.66-7.11 and 7.88-8.18 respectively. The SSA values for Grahamstown and Tiaret were 218 ± 108 and 261 ± 99.9 m2/g, and the CEC values were 119 ± 2.09 and 136 ± 6.03 mEq/100, respectively. The LOI values obtained were 1.33 ± 0.03 and 1.48 ± 0.11 % for Grahamstown and Tiaret, respectively. E. coll and heterotrophic bacteria were the pathogens determined, and were extracted from sludge using sterile saline and nutrient broth. The concentration of E. coll in Grahamstown and Tiaret sludge were 468 ± 7.63 and 7769 ± 1268 CFU/g d.w and for heterotrophic bacteria were 1.17x109 ± 7.42x108 and 1.43x109 ± 9.11 x108 CFU/g d.w. For Grahamstown sludge, the concentration of nitrates, ammonium and phosphates were 55.61 ± 55.20 mg/g d.w, 6.60 ± 2.36 mg/g d.w and 1.40 ± 0.30 mg/g d.w, respectively. For Tiaret sludge, the concentration of nitrates, ammonium and phosphates were 2.56 ± 2.90 mg/g d.w, 0.64 ± 0.45 mg/g d.w and 0.24 ± 0.19 mg/g d.w, respectively. The concentration of Mn, Cu, Pb and Cd in Grahamstown sludge were 423 ± 101, 353 ± 92, 40.2 ± 20 and 0.0 mg/kg d.w respectively, and for Tiaret sludge, the corresponding concentrations were 358± 295, 549±50, 1427± 1352 and 1.54 ± 0.61 mg/kg d.w. Sewage sludge was found to contain Triclosan, and solubility studies of the compound were conducted using sodium deoxycholate and sodium lithocholate. The apparent solubilities and rate constants indicated in brackets of TCS at 37 °C were 35.4 ± 1.21 mg/L (1.28 ± 0.36 Hr-) and 14.4 ± 0.34 mg/L (0.99 ± 0.17 Hr-) in sodium lithocholate and sodium deoxycholate, respectively. The apparent solubilities and rate constants indicated in brackets of TCS at 15 °C were 32.3 ± 0.88 mg/L (2.16 ± 0.80 Hr-) and 14.2 ± 0.39 mg/L (1.02 ± 0.17 Hr-) in sodium lithocholate and sodium deoxycholate, respectively. Triclosan was extracted from sludge using 1 g/L sodium deoxycholate and the determined concentration were 142 ± 33.5 gg/g d.w for Grahamstown sludge and 0-12 gg/g d.w for Tiaret sludge. Finally plant growth studies were conducted on radish and garden cress plants using Grahamstown sludge at 0, 20, 40, 80 and 100 % treatments. Statistical analysis (t-test and Kruskal-Wallis) at 5 % level of significance was done to compare growth parameters between control and different sludge treatments. For radish plants, the values for plant height, root length, number of leaves, leaf length and dry mass were 28.4-80-7 mm, 4.3-44.7 mm, 3.3-17.0 mm, 2.3-4.0 leaves and 6.3-15.3 %, respectively. For garden cress, the values for plant height, root length, number of leaves, leaf length and dry mass were 13.7-25.0 mm, 7.7-20.3 mm, 5.7-8.3 leaves, 3.0-8.3 mm and 8.8-15.0 %, respectively. Twenty percent (20 %) sludge treatment gave the best results in radish and garden cress plants with respect to plant height, root length, number of leaves and dry mass. Triclosan concentration in radish and garden cress plants was below the detection limit of 32.4 gg/g d.w. , Thesis (MSc) -- Faculty of Pharmacy, Pharmacy, 2017
- Full Text:
- Date Issued: 2017
- Authors: Ncube, Mbonisi
- Date: 2017
- Subjects: Sewage sludge , Sewage Purification South Africa Grahamstown , Sewage Purification Algeria Tiaret , Sewage sludge as fertilizer , Anti-infective agents
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/65156 , vital:28697
- Description: Physicochemical properties such as pH, specific surface area (SSA), cationic exchange capacity (CEC), loss on ignition (LOI), pathogens, plant nutrients (nitrates, ammonium and phosphates), and heavy metals (manganese, copper, lead and cadmium) were determined for sewage sludge from Grahamstown and Tiaret. The values obtained were log transformed thereafter a t-test at 5 % level of significance was used to test for the difference in each parameter for both sludges. The pH of sludge was determined in 1:3 water, 16 water, 1:3 0.01 M calcium chloride and 1:3 1 M potassium chloride. The pH for Grahamstown and Tiaret sludge were in the ranges of 6.66-7.11 and 7.88-8.18 respectively. The SSA values for Grahamstown and Tiaret were 218 ± 108 and 261 ± 99.9 m2/g, and the CEC values were 119 ± 2.09 and 136 ± 6.03 mEq/100, respectively. The LOI values obtained were 1.33 ± 0.03 and 1.48 ± 0.11 % for Grahamstown and Tiaret, respectively. E. coll and heterotrophic bacteria were the pathogens determined, and were extracted from sludge using sterile saline and nutrient broth. The concentration of E. coll in Grahamstown and Tiaret sludge were 468 ± 7.63 and 7769 ± 1268 CFU/g d.w and for heterotrophic bacteria were 1.17x109 ± 7.42x108 and 1.43x109 ± 9.11 x108 CFU/g d.w. For Grahamstown sludge, the concentration of nitrates, ammonium and phosphates were 55.61 ± 55.20 mg/g d.w, 6.60 ± 2.36 mg/g d.w and 1.40 ± 0.30 mg/g d.w, respectively. For Tiaret sludge, the concentration of nitrates, ammonium and phosphates were 2.56 ± 2.90 mg/g d.w, 0.64 ± 0.45 mg/g d.w and 0.24 ± 0.19 mg/g d.w, respectively. The concentration of Mn, Cu, Pb and Cd in Grahamstown sludge were 423 ± 101, 353 ± 92, 40.2 ± 20 and 0.0 mg/kg d.w respectively, and for Tiaret sludge, the corresponding concentrations were 358± 295, 549±50, 1427± 1352 and 1.54 ± 0.61 mg/kg d.w. Sewage sludge was found to contain Triclosan, and solubility studies of the compound were conducted using sodium deoxycholate and sodium lithocholate. The apparent solubilities and rate constants indicated in brackets of TCS at 37 °C were 35.4 ± 1.21 mg/L (1.28 ± 0.36 Hr-) and 14.4 ± 0.34 mg/L (0.99 ± 0.17 Hr-) in sodium lithocholate and sodium deoxycholate, respectively. The apparent solubilities and rate constants indicated in brackets of TCS at 15 °C were 32.3 ± 0.88 mg/L (2.16 ± 0.80 Hr-) and 14.2 ± 0.39 mg/L (1.02 ± 0.17 Hr-) in sodium lithocholate and sodium deoxycholate, respectively. Triclosan was extracted from sludge using 1 g/L sodium deoxycholate and the determined concentration were 142 ± 33.5 gg/g d.w for Grahamstown sludge and 0-12 gg/g d.w for Tiaret sludge. Finally plant growth studies were conducted on radish and garden cress plants using Grahamstown sludge at 0, 20, 40, 80 and 100 % treatments. Statistical analysis (t-test and Kruskal-Wallis) at 5 % level of significance was done to compare growth parameters between control and different sludge treatments. For radish plants, the values for plant height, root length, number of leaves, leaf length and dry mass were 28.4-80-7 mm, 4.3-44.7 mm, 3.3-17.0 mm, 2.3-4.0 leaves and 6.3-15.3 %, respectively. For garden cress, the values for plant height, root length, number of leaves, leaf length and dry mass were 13.7-25.0 mm, 7.7-20.3 mm, 5.7-8.3 leaves, 3.0-8.3 mm and 8.8-15.0 %, respectively. Twenty percent (20 %) sludge treatment gave the best results in radish and garden cress plants with respect to plant height, root length, number of leaves and dry mass. Triclosan concentration in radish and garden cress plants was below the detection limit of 32.4 gg/g d.w. , Thesis (MSc) -- Faculty of Pharmacy, Pharmacy, 2017
- Full Text:
- Date Issued: 2017
Composition portfolio
- Boesack, Lenrick Jonathan Angus
- Authors: Boesack, Lenrick Jonathan Angus
- Date: 2017
- Subjects: Piano music , Prepared piano music , Saxophone music
- Language: English
- Type: text , Thesis , Masters , MMus
- Identifier: http://hdl.handle.net/10962/56233 , vital:26786
- Description: This short composition portfolio comprises 40% of the requirements for the Master of Music Degree in performance and composition at Rhodes University. In addition to the music presented here, I played two public exam recitals of 70 minutes each. While I played piano as a child, my main instrument during my BMUS studies at the University of Cape Town (2004-2007) was the saxophone. In 2010 I was diagnosed with Polymyositis(an auto-immune desease) which particularly affected my breathing and therefore my ability to play the saxophone. For this reason I opted to play my recitals on the piano. The first recital focused on interpretations of Swing Era, Bebop and post-Bebop standards such as: Someday my prince will come, What is this thing called love, In your own sweet way, Eternal Triangle, Recordame, Peace, Dolphin Dance, Caravan and Some other blues. The second recital comprised of seven original compositions that were presented in trio, quartet and quintet settings.
- Full Text:
- Date Issued: 2017
- Authors: Boesack, Lenrick Jonathan Angus
- Date: 2017
- Subjects: Piano music , Prepared piano music , Saxophone music
- Language: English
- Type: text , Thesis , Masters , MMus
- Identifier: http://hdl.handle.net/10962/56233 , vital:26786
- Description: This short composition portfolio comprises 40% of the requirements for the Master of Music Degree in performance and composition at Rhodes University. In addition to the music presented here, I played two public exam recitals of 70 minutes each. While I played piano as a child, my main instrument during my BMUS studies at the University of Cape Town (2004-2007) was the saxophone. In 2010 I was diagnosed with Polymyositis(an auto-immune desease) which particularly affected my breathing and therefore my ability to play the saxophone. For this reason I opted to play my recitals on the piano. The first recital focused on interpretations of Swing Era, Bebop and post-Bebop standards such as: Someday my prince will come, What is this thing called love, In your own sweet way, Eternal Triangle, Recordame, Peace, Dolphin Dance, Caravan and Some other blues. The second recital comprised of seven original compositions that were presented in trio, quartet and quintet settings.
- Full Text:
- Date Issued: 2017
Composition portfolio
- Authors: Caplan, Anthony
- Date: 2017
- Language: English
- Type: text , Thesis , Masters , MMus
- Identifier: http://hdl.handle.net/10962/6940 , vital:21202
- Description: Restricted access-thesis available at the Music Library
- Full Text: false
- Date Issued: 2017
- Authors: Caplan, Anthony
- Date: 2017
- Language: English
- Type: text , Thesis , Masters , MMus
- Identifier: http://hdl.handle.net/10962/6940 , vital:21202
- Description: Restricted access-thesis available at the Music Library
- Full Text: false
- Date Issued: 2017
Comprehensive kinetic analysis of thermoluminescence peaks of α-Al2O3: C, Mg
- Kalita, Jitumani M, Chithambo, Makaiko L
- Authors: Kalita, Jitumani M , Chithambo, Makaiko L
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/116142 , vital:34323 , https://doi.org/10.1016/j.jlumin.2017.01.003
- Description: A comprehensive kinetic analysis of the glow peaks in α-Al2O3:C,Mg is reported. A thermoluminescence glow curve measured at 1 °C/s after beta irradiation to 1 Gy shows a high intensity peak hereafter referred to as the main peak at 161 °C and six lower intensity secondary peaks at 42, 72, 193, 279, 330, 370 °C respectively. For ease of reference, the secondary peaks are labelled as I, II, IV, V, VI and VII respectively and the main peak denoted peak III. Kinetic analysis of the glow peaks has been carried out using the initial rise, whole glow peak, peak shape, variable heating rate and glow curve deconvolution methods as well as by way of phosphorescence. Using Tm-Tstop, Tm-dose and phosphorescence analyses, the order of kinetics of the peaks has been evaluated as first order. Analysis by the peak shape, whole glow peak and deconvolution methods produce the same conclusion. The activation energy of peaks I through VII are calculated as ~0.83, 0.96, 1.37, 1.20, 1.15, 1.61 and 1.94 eV respectively. The frequency factors for all the peaks are of the order of 109 to 1014 s−1. The question of thermal quenching affecting the peaks was considered. The peaks III, IV and V, the only ones that could be conveniently studied in this regard, were found to be affected by thermal quenching. The activation energy for thermal quenching was calculated for peak III as 0.96±0.03 eV, for peak VI as 0.95±0.07 eV and for peak V as 1.26±0.08 eV. The thermal quenching phenomenon has been discussed with reference to F+ and F centres. An energy band model has been developed to discuss the luminescence mechanisms in α-Al2O3:C,Mg in light of finding in this work.
- Full Text: false
- Date Issued: 2017
- Authors: Kalita, Jitumani M , Chithambo, Makaiko L
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/116142 , vital:34323 , https://doi.org/10.1016/j.jlumin.2017.01.003
- Description: A comprehensive kinetic analysis of the glow peaks in α-Al2O3:C,Mg is reported. A thermoluminescence glow curve measured at 1 °C/s after beta irradiation to 1 Gy shows a high intensity peak hereafter referred to as the main peak at 161 °C and six lower intensity secondary peaks at 42, 72, 193, 279, 330, 370 °C respectively. For ease of reference, the secondary peaks are labelled as I, II, IV, V, VI and VII respectively and the main peak denoted peak III. Kinetic analysis of the glow peaks has been carried out using the initial rise, whole glow peak, peak shape, variable heating rate and glow curve deconvolution methods as well as by way of phosphorescence. Using Tm-Tstop, Tm-dose and phosphorescence analyses, the order of kinetics of the peaks has been evaluated as first order. Analysis by the peak shape, whole glow peak and deconvolution methods produce the same conclusion. The activation energy of peaks I through VII are calculated as ~0.83, 0.96, 1.37, 1.20, 1.15, 1.61 and 1.94 eV respectively. The frequency factors for all the peaks are of the order of 109 to 1014 s−1. The question of thermal quenching affecting the peaks was considered. The peaks III, IV and V, the only ones that could be conveniently studied in this regard, were found to be affected by thermal quenching. The activation energy for thermal quenching was calculated for peak III as 0.96±0.03 eV, for peak VI as 0.95±0.07 eV and for peak V as 1.26±0.08 eV. The thermal quenching phenomenon has been discussed with reference to F+ and F centres. An energy band model has been developed to discuss the luminescence mechanisms in α-Al2O3:C,Mg in light of finding in this work.
- Full Text: false
- Date Issued: 2017
Computational design of a smart and efficient control system for a residential air source heat pump water heater
- Authors: Yongoua Nana Joel
- Date: 2017
- Subjects: Heat pumps -- Specifications Water heaters Renewable energy sources
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/4582 , vital:28435
- Description: An air source heat pump (ASHP) water heater is a renewable and energy efficient hot water heating technology. ASHP water heaters are fast gaining maturity in the South African market and in Africa at large due to their low energy consumption (about 67 percent lower than conventional geysers), relatively low installation and operation cost, their environmental friendly nature and possibly the ease to retrofit with the old inefficient technologies. Furthermore, ASHP water heaters make use of some of the most recent advancement in refrigeration technologies enhancing their performance through a wide range of weather conditions. However, residential ASHP water heaters which come at the tail of a series of highly sophisticated models still harbour primitive control designs. One of such control system is the intermittent (on/off) control whereby the ASHP unit responds to a temperature differential threshold rather than instantaneous temperature fluctuations. Unfortunately, this control method contributes to a rapid deterioration of the compressor and other actuators due to high starting current during transient states and partial loading. Capacity control is a better alterative as it offers a more reliable system’s performance as well as a better protection for the system components. However, the drawbacks of implementing such a technology on residential ASHP water heaters is the initial purchasing cost. We use a systematic approach in this research to circumvent the purchasing cost and complete redesign hysteresis. The first step was centered around a hypothetical analysis of the performance of the heat exchangers in a bid to uncover the weakness during the operation of a residential ASHP water heater. It was observed that at ambient temperatures above 22°C notably during summer and winter afternoons, water only harnesses about 75 percent of the total heat rejected. Furthermore, the actuators keep doing work for about 15-20 minutes even after the heat transfer process has ceased completely. Following these observations, a sequential flow algorithm was developed aimed at matching the consumption point to weather variables like ambient temperature and secondly to most efficiently synchronize actuator components for a better energy management. This novel control method can save up to 58 percent of energy compared to the conventional on/off method during summer afternoons and averagely 20 percent during the rest of the day. It also has the merit to be cost effective as it barely requires no component retrofitting.
- Full Text:
- Date Issued: 2017
- Authors: Yongoua Nana Joel
- Date: 2017
- Subjects: Heat pumps -- Specifications Water heaters Renewable energy sources
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/4582 , vital:28435
- Description: An air source heat pump (ASHP) water heater is a renewable and energy efficient hot water heating technology. ASHP water heaters are fast gaining maturity in the South African market and in Africa at large due to their low energy consumption (about 67 percent lower than conventional geysers), relatively low installation and operation cost, their environmental friendly nature and possibly the ease to retrofit with the old inefficient technologies. Furthermore, ASHP water heaters make use of some of the most recent advancement in refrigeration technologies enhancing their performance through a wide range of weather conditions. However, residential ASHP water heaters which come at the tail of a series of highly sophisticated models still harbour primitive control designs. One of such control system is the intermittent (on/off) control whereby the ASHP unit responds to a temperature differential threshold rather than instantaneous temperature fluctuations. Unfortunately, this control method contributes to a rapid deterioration of the compressor and other actuators due to high starting current during transient states and partial loading. Capacity control is a better alterative as it offers a more reliable system’s performance as well as a better protection for the system components. However, the drawbacks of implementing such a technology on residential ASHP water heaters is the initial purchasing cost. We use a systematic approach in this research to circumvent the purchasing cost and complete redesign hysteresis. The first step was centered around a hypothetical analysis of the performance of the heat exchangers in a bid to uncover the weakness during the operation of a residential ASHP water heater. It was observed that at ambient temperatures above 22°C notably during summer and winter afternoons, water only harnesses about 75 percent of the total heat rejected. Furthermore, the actuators keep doing work for about 15-20 minutes even after the heat transfer process has ceased completely. Following these observations, a sequential flow algorithm was developed aimed at matching the consumption point to weather variables like ambient temperature and secondly to most efficiently synchronize actuator components for a better energy management. This novel control method can save up to 58 percent of energy compared to the conventional on/off method during summer afternoons and averagely 20 percent during the rest of the day. It also has the merit to be cost effective as it barely requires no component retrofitting.
- Full Text:
- Date Issued: 2017
Conceptualising knowledge for access in the sciences: academic development from a social realist perspective
- Authors: Ellery, Karen
- Date: 2017
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/59863 , vital:27671 , https://doi.org/10.1007/s10734-016-0085-x
- Description: Whilst arguing from a social realist perspective that knowledge matters in academic development (AD) curricula, this paper addresses the question of what knowledge types and practices are necessary for enabling epistemological access. It presents a single, in-depth, qualitative case study in which the curriculum of a science AD course is characterised using Legitimation Code Theory (LCT). Analysis of the course curriculum reveals legitimation of four main categories of knowledge types along a continuum of stronger to weaker epistemic relations: disciplinary knowledge, scientific literacies knowledge, general academic practices knowledge and everyday knowledge. These categories are ‘mapped’ onto an LCT(Semantics)(how meaning relates to both context and empirical referents) topological plane to reveal a curriculum that operates in three distinct but interrelated spaces by facing towards both the field of science and the practice of academia. It is argued that this empirically derived differentiated curriculum framework offers a conceptual means for considering the notion of access to ‘powerful’ knowledge in a range of AD and mainstream contexts.
- Full Text:
- Date Issued: 2017
- Authors: Ellery, Karen
- Date: 2017
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/59863 , vital:27671 , https://doi.org/10.1007/s10734-016-0085-x
- Description: Whilst arguing from a social realist perspective that knowledge matters in academic development (AD) curricula, this paper addresses the question of what knowledge types and practices are necessary for enabling epistemological access. It presents a single, in-depth, qualitative case study in which the curriculum of a science AD course is characterised using Legitimation Code Theory (LCT). Analysis of the course curriculum reveals legitimation of four main categories of knowledge types along a continuum of stronger to weaker epistemic relations: disciplinary knowledge, scientific literacies knowledge, general academic practices knowledge and everyday knowledge. These categories are ‘mapped’ onto an LCT(Semantics)(how meaning relates to both context and empirical referents) topological plane to reveal a curriculum that operates in three distinct but interrelated spaces by facing towards both the field of science and the practice of academia. It is argued that this empirically derived differentiated curriculum framework offers a conceptual means for considering the notion of access to ‘powerful’ knowledge in a range of AD and mainstream contexts.
- Full Text:
- Date Issued: 2017