Biological evaluation and semi-synthesis of Isolated compounds from (Syzygium aromaticum (L.) Merr. & Perry) Buds
- Authors: Sibusiso, Rali
- Date: 2014
- Language: English
- Type: Thesis , Masters , MSc (Chemistry)
- Identifier: vital:11352 , http://hdl.handle.net/10353/d1021140
- Description: Natural products play a fundamental role in modern drug discovery as they continue providing diverse bioactive lead compounds for new drug formulation. However, isolation of these valued compounds is problematic. On the other hand, the morbidity and mortality rates caused by non-communicable diseases are increasing with improved longevity. Thus, the study herein focused on the isolation of plant-derived compounds from Syzygium aromaticum and evaluated their biological properties. Syzygium aromaticum is a well-known plant which belongs to family Myrtaceae. Dried flower buds of S. aromaticum were subjected to sequential solvent extraction. The ethyl acetate extract (15.535 g) was subjected to column chromatography using a silica gel (0.063-0.200 mm) for isolation. This has led to the isolation of three distinct compounds that were identified as eugenol, maslinic acid (MA) and oleanolic acid (OA). The structural elucidation of these valued compounds was done using NMR, GC-MS, LC-MS, FT-IR and Mp. Further semi-synthesis of the oleanolic acid afforded acetate and ester OA-derived compounds with better solubility properties. All these compounds were evaluated for analgesic and anti-inflammatory properties. All tested compounds were administered at a dose of 40 mg/kg to both Wistar rats and Swiss mice. Significant (p<0.01) analgesic and anti-inflammatory properties are obtained for all compounds. The effects of eugenol in all experiment were better except in the thermal-induced pain or tail flick test. In the case of modified compounds, the formalin induced pain test disclosed that oleanane derived compounds confessed analgesic and anti-inflammatory effects better than OA, whereas, in tale flick test oleanolic acid proved superior analgesic effects compared to all its derivatives with the exception of the acetyl-derivative. Acute anti-inflammatory test showed that acetyl-derivatives were more active than other compounds. In conclusion, chromatographic techniques and semi-synthesise of oleanolic acid have resulted to several plant-derived compounds with analgesic and anti-inflammatory properties. The semi-synthesized compounds may serve as alternative drug candidates for new analgesic and anti-inflammatory drug formulation
- Full Text:
- Authors: Sibusiso, Rali
- Date: 2014
- Language: English
- Type: Thesis , Masters , MSc (Chemistry)
- Identifier: vital:11352 , http://hdl.handle.net/10353/d1021140
- Description: Natural products play a fundamental role in modern drug discovery as they continue providing diverse bioactive lead compounds for new drug formulation. However, isolation of these valued compounds is problematic. On the other hand, the morbidity and mortality rates caused by non-communicable diseases are increasing with improved longevity. Thus, the study herein focused on the isolation of plant-derived compounds from Syzygium aromaticum and evaluated their biological properties. Syzygium aromaticum is a well-known plant which belongs to family Myrtaceae. Dried flower buds of S. aromaticum were subjected to sequential solvent extraction. The ethyl acetate extract (15.535 g) was subjected to column chromatography using a silica gel (0.063-0.200 mm) for isolation. This has led to the isolation of three distinct compounds that were identified as eugenol, maslinic acid (MA) and oleanolic acid (OA). The structural elucidation of these valued compounds was done using NMR, GC-MS, LC-MS, FT-IR and Mp. Further semi-synthesis of the oleanolic acid afforded acetate and ester OA-derived compounds with better solubility properties. All these compounds were evaluated for analgesic and anti-inflammatory properties. All tested compounds were administered at a dose of 40 mg/kg to both Wistar rats and Swiss mice. Significant (p<0.01) analgesic and anti-inflammatory properties are obtained for all compounds. The effects of eugenol in all experiment were better except in the thermal-induced pain or tail flick test. In the case of modified compounds, the formalin induced pain test disclosed that oleanane derived compounds confessed analgesic and anti-inflammatory effects better than OA, whereas, in tale flick test oleanolic acid proved superior analgesic effects compared to all its derivatives with the exception of the acetyl-derivative. Acute anti-inflammatory test showed that acetyl-derivatives were more active than other compounds. In conclusion, chromatographic techniques and semi-synthesise of oleanolic acid have resulted to several plant-derived compounds with analgesic and anti-inflammatory properties. The semi-synthesized compounds may serve as alternative drug candidates for new analgesic and anti-inflammatory drug formulation
- Full Text:
Challenges faced by traditional healers when treating people living with HIV and AIDS: the case of Intsika Municipality, Eastern Cape province
- Authors: Zimba, Zibonele France
- Date: 2014
- Subjects: People with HIV and AIDS disease -- Healers -- South Africa , Traditional medicine -- South Africa , HIV infections -- Treatment -- South Africa , AIDS (Disease) -- Treatment -- South Africa
- Language: English
- Type: Thesis , Masters , M SW
- Identifier: vital:11768 , http://hdl.handle.net/10353/d1015357 , People with HIV and AIDS disease -- Healers -- South Africa , Traditional medicine -- South Africa , HIV infections -- Treatment -- South Africa , AIDS (Disease) -- Treatment -- South Africa
- Description: The aim of the study was to examine the procedures followed by traditional healers treating people living with HIV and AIDS in the Instika Municipality and the challenges faced by them in this endeavour. Using the qualitative research method, in-depth interviews and focus group discussions were conducted with twenty traditional healers. Among the significant findings of this study were the hardships encountered by traditional healers in terms of finance, the transport needed to collect medicinal plants, the shortage of medicinal plants, the lack of co-operation from the formal health care sector and the discrimination and abuse suffered at the hands of members of the community, with Christians and members of the SAPS being among the chief antagonists. It is also acknowledged in this study that traditional healers have been trained by the Department of Health concerning issues of hygiene and that traditional healers have knowledge of the symptoms of HIV and AIDS. It can therefore be concluded that traditional healers have a significant role to play in preventing the spread of HIV and AIDS if they employ preventative measures such as the use of protective gloves and limiting the use of a blade to one patient only. However, traditional healers are not supplied with safety kits or condoms to distribute to patients who consult them for treatment of STIs.
- Full Text:
- Authors: Zimba, Zibonele France
- Date: 2014
- Subjects: People with HIV and AIDS disease -- Healers -- South Africa , Traditional medicine -- South Africa , HIV infections -- Treatment -- South Africa , AIDS (Disease) -- Treatment -- South Africa
- Language: English
- Type: Thesis , Masters , M SW
- Identifier: vital:11768 , http://hdl.handle.net/10353/d1015357 , People with HIV and AIDS disease -- Healers -- South Africa , Traditional medicine -- South Africa , HIV infections -- Treatment -- South Africa , AIDS (Disease) -- Treatment -- South Africa
- Description: The aim of the study was to examine the procedures followed by traditional healers treating people living with HIV and AIDS in the Instika Municipality and the challenges faced by them in this endeavour. Using the qualitative research method, in-depth interviews and focus group discussions were conducted with twenty traditional healers. Among the significant findings of this study were the hardships encountered by traditional healers in terms of finance, the transport needed to collect medicinal plants, the shortage of medicinal plants, the lack of co-operation from the formal health care sector and the discrimination and abuse suffered at the hands of members of the community, with Christians and members of the SAPS being among the chief antagonists. It is also acknowledged in this study that traditional healers have been trained by the Department of Health concerning issues of hygiene and that traditional healers have knowledge of the symptoms of HIV and AIDS. It can therefore be concluded that traditional healers have a significant role to play in preventing the spread of HIV and AIDS if they employ preventative measures such as the use of protective gloves and limiting the use of a blade to one patient only. However, traditional healers are not supplied with safety kits or condoms to distribute to patients who consult them for treatment of STIs.
- Full Text:
Changing marriage practices: the case of urban working class in East London, South Africa
- Authors: Stofile, Zimkhitha Sphokazi
- Date: 2014
- Subjects: Marriage -- South Africa -- Eastern Cape , Interpersonal relations
- Language: English
- Type: Thesis , Masters , M Soc Sc (African Studies)
- Identifier: http://hdl.handle.net/10353/1283 , vital:26542 , Marriage -- South Africa -- Eastern Cape , Interpersonal relations
- Description: This research sought to examine changing meaning of marriage and meaning of family among urban working class residing in East London and how their perceptions of marriage have shifted from the orthodox norms. This study was conducted in Amalinda, which is one of the East London suburbs. Interviews were conducted with male and female informants. It is acknowledged in this study that marriage has traditionally been regarded as imperative in both African and Western cultures. However, there have been some drastic changes in the marriage institution in the twenty-first century. This study found out that people have shifted from the orthodox practices of marriage. The traditional culture has been influenced by various factors such as education, globalisation, and urbanisation. Furthermore, there has been a rise in the number of people who cohabit, increase in the age of first marriage, premarital childbearing and there has been a decline in the number of polygamous marriages and arranged marriages and a number of people have no problem with same-sex marriages. Furthermore, financial implications and financial securities play are influences on why some people choose or not choose to marry.
- Full Text:
- Authors: Stofile, Zimkhitha Sphokazi
- Date: 2014
- Subjects: Marriage -- South Africa -- Eastern Cape , Interpersonal relations
- Language: English
- Type: Thesis , Masters , M Soc Sc (African Studies)
- Identifier: http://hdl.handle.net/10353/1283 , vital:26542 , Marriage -- South Africa -- Eastern Cape , Interpersonal relations
- Description: This research sought to examine changing meaning of marriage and meaning of family among urban working class residing in East London and how their perceptions of marriage have shifted from the orthodox norms. This study was conducted in Amalinda, which is one of the East London suburbs. Interviews were conducted with male and female informants. It is acknowledged in this study that marriage has traditionally been regarded as imperative in both African and Western cultures. However, there have been some drastic changes in the marriage institution in the twenty-first century. This study found out that people have shifted from the orthodox practices of marriage. The traditional culture has been influenced by various factors such as education, globalisation, and urbanisation. Furthermore, there has been a rise in the number of people who cohabit, increase in the age of first marriage, premarital childbearing and there has been a decline in the number of polygamous marriages and arranged marriages and a number of people have no problem with same-sex marriages. Furthermore, financial implications and financial securities play are influences on why some people choose or not choose to marry.
- Full Text:
Characterization and computer simulation of corn stover/coal blends for co-gasification in a downdraft gasifier
- Authors: Mabizela, Polycarp Sbusiso
- Date: 2014
- Language: English
- Type: Thesis , Masters , MSc (Physics)
- Identifier: vital:11600 , http://hdl.handle.net/10353/d1020203
- Description: The need for sustainable alternative energy technology is becoming more urgent as the demand for clean energy environment increases. For centuries, electricity in South Africa has been derived mostly from coal with results growing in multifold annually due to concerns about the impact of fossil fuel utilization related to emission of greenhouse gasses. It is practically impossible at the moment to replace coal with biomass resources because of the low energy value of biomass. However, the conversion of coal has experienced some challenges especially during its gasification which includes, but are not limited to a high reaction temperature exceeding 900°C which most gasifiers cannot achieve, and if achieved in most cases, combustion of the resulting syngas usually occur, leading to low conversion efficiency and the risk of reaching extremely high temperatures that may result in pressure build up and explosion may also occur. Therefore, this study sought to investigate the possibility of co-gasifying corn stover with coal with the ultimate aim establishing the best mixing ratio that would result in optimum co-gasification efficiency after computer simulation. Proximate and ultimate analysis, including energy values of corn stover and coal as well as their blends were undertaken and results showed significant differences between the two feedstocks and narrow range composition betwee their blends in terms of properties and energy value. Corn stover showed a higher fraction of volatile matter and lower ash content than coal, whereas those of their blends vary considerably in terms of physical properties. Differences in chemical composition also showed higher fraction of hydrogen and oxygen, and less carbon than coal while those of their blends vary according to the ratio of corn stover to coal and vice versa in the blends. The thermal stability of corn stover and coal as well as their blends were also established and the maximum temperature reached for thermal degradation of their blends was 900°C as depicted by TGA analysis. The SEM results revealed no changes in morphology of the pure samples of corn stover and coal which was due to the fact that a pre-treatment of the samples were not undertaken, whereas the blends showed significant changes in morphology as a result of blending. However, luminous and non-luminous features were noticed in both SEM images of the blends with the 10% coal/90% corn stover blend having higher percentages of luminosity as a result of higher quantities of coal in the blend. The energy density of the samples were also measured and found to be 16.1 MJ/kg and 22.8 MJ/kg for corn stover and coal respectively. Those of their blends varied from 16.9 to approximately 23.5 MJ/kg. These results were used to conduct computer simulation of the co-gasification process in order to establish the best blend that would result in maximum co-gasification efficiency. The blend 90% corn stover/10% coal was found to be the most suitable blend for co-gasification resulting in an efficiency of approximately 58% because its conversion was efficiently achieved at a temperature that is intermediate to that of coal and biomass independently. The simulation results were, however, compared with experimental data found in the literature and results showed only slight variation between them.
- Full Text:
- Authors: Mabizela, Polycarp Sbusiso
- Date: 2014
- Language: English
- Type: Thesis , Masters , MSc (Physics)
- Identifier: vital:11600 , http://hdl.handle.net/10353/d1020203
- Description: The need for sustainable alternative energy technology is becoming more urgent as the demand for clean energy environment increases. For centuries, electricity in South Africa has been derived mostly from coal with results growing in multifold annually due to concerns about the impact of fossil fuel utilization related to emission of greenhouse gasses. It is practically impossible at the moment to replace coal with biomass resources because of the low energy value of biomass. However, the conversion of coal has experienced some challenges especially during its gasification which includes, but are not limited to a high reaction temperature exceeding 900°C which most gasifiers cannot achieve, and if achieved in most cases, combustion of the resulting syngas usually occur, leading to low conversion efficiency and the risk of reaching extremely high temperatures that may result in pressure build up and explosion may also occur. Therefore, this study sought to investigate the possibility of co-gasifying corn stover with coal with the ultimate aim establishing the best mixing ratio that would result in optimum co-gasification efficiency after computer simulation. Proximate and ultimate analysis, including energy values of corn stover and coal as well as their blends were undertaken and results showed significant differences between the two feedstocks and narrow range composition betwee their blends in terms of properties and energy value. Corn stover showed a higher fraction of volatile matter and lower ash content than coal, whereas those of their blends vary considerably in terms of physical properties. Differences in chemical composition also showed higher fraction of hydrogen and oxygen, and less carbon than coal while those of their blends vary according to the ratio of corn stover to coal and vice versa in the blends. The thermal stability of corn stover and coal as well as their blends were also established and the maximum temperature reached for thermal degradation of their blends was 900°C as depicted by TGA analysis. The SEM results revealed no changes in morphology of the pure samples of corn stover and coal which was due to the fact that a pre-treatment of the samples were not undertaken, whereas the blends showed significant changes in morphology as a result of blending. However, luminous and non-luminous features were noticed in both SEM images of the blends with the 10% coal/90% corn stover blend having higher percentages of luminosity as a result of higher quantities of coal in the blend. The energy density of the samples were also measured and found to be 16.1 MJ/kg and 22.8 MJ/kg for corn stover and coal respectively. Those of their blends varied from 16.9 to approximately 23.5 MJ/kg. These results were used to conduct computer simulation of the co-gasification process in order to establish the best blend that would result in maximum co-gasification efficiency. The blend 90% corn stover/10% coal was found to be the most suitable blend for co-gasification resulting in an efficiency of approximately 58% because its conversion was efficiently achieved at a temperature that is intermediate to that of coal and biomass independently. The simulation results were, however, compared with experimental data found in the literature and results showed only slight variation between them.
- Full Text:
Clinical experiences of third-year student nurses in a public college in the Eastern Cape
- Authors: Tyanti, Mandisa
- Date: 2014
- Language: English
- Type: Thesis , Masters , MSc (Nursing Science)
- Identifier: vital:11912 , http://hdl.handle.net/10353/d1016097
- Description: Clinical experience has always been an important part of nursing education. Nursing colleges require students to be placed in clinical areas in order to acquire new knowledge and skills. The purpose of the study was to explore and describe the clinical experiences during their clinical placement of the third-year student nurses at a public college in the Eastern Cape. The objectives of this study were: to explore and describe the experiences of the third-year student of a public nursing college in the Eastern Cape, and to describe strategies for the improvement of student learning during clinical practice. A qualitative, explorative and descriptive research design was used to describe the clinical experiences of these student nurses and the strategies for the improvement of student learning during clinical practice. Data were collected from focus group interviews, using a purposive and convenience sample from one college campus in the Eastern Cape. Tesch’s method of data analysis (in Creswell, 2003) was used to analyse data. Trustworthiness was ensured in this research by using Guba’s model (in Lincoln & Guba, 1985) of qualitative research. Ethical approval was obtained from the University of Fort Hare Research Ethics Committee, the Department of Health, Eastern Cape, the Head of the Nursing College, the Campus Head and the participants and ethical consideration was ensured throughout the research process. Themes and sub-themes emerged from data collected about the clinical experiences of the nurses. The study brought to light the experiences of third-year student nurses during allocation to clinical areas. The findings from this study revealed the need for proper clinical accompaniment by college staff to ensure that clinical learning is taking place. Strategies to improve learning in the clinical areas are described. and recommendations for nursing education and nursing practice are made. If this is applied, it will help the student nurses to be better professionals.
- Full Text:
- Authors: Tyanti, Mandisa
- Date: 2014
- Language: English
- Type: Thesis , Masters , MSc (Nursing Science)
- Identifier: vital:11912 , http://hdl.handle.net/10353/d1016097
- Description: Clinical experience has always been an important part of nursing education. Nursing colleges require students to be placed in clinical areas in order to acquire new knowledge and skills. The purpose of the study was to explore and describe the clinical experiences during their clinical placement of the third-year student nurses at a public college in the Eastern Cape. The objectives of this study were: to explore and describe the experiences of the third-year student of a public nursing college in the Eastern Cape, and to describe strategies for the improvement of student learning during clinical practice. A qualitative, explorative and descriptive research design was used to describe the clinical experiences of these student nurses and the strategies for the improvement of student learning during clinical practice. Data were collected from focus group interviews, using a purposive and convenience sample from one college campus in the Eastern Cape. Tesch’s method of data analysis (in Creswell, 2003) was used to analyse data. Trustworthiness was ensured in this research by using Guba’s model (in Lincoln & Guba, 1985) of qualitative research. Ethical approval was obtained from the University of Fort Hare Research Ethics Committee, the Department of Health, Eastern Cape, the Head of the Nursing College, the Campus Head and the participants and ethical consideration was ensured throughout the research process. Themes and sub-themes emerged from data collected about the clinical experiences of the nurses. The study brought to light the experiences of third-year student nurses during allocation to clinical areas. The findings from this study revealed the need for proper clinical accompaniment by college staff to ensure that clinical learning is taking place. Strategies to improve learning in the clinical areas are described. and recommendations for nursing education and nursing practice are made. If this is applied, it will help the student nurses to be better professionals.
- Full Text:
Core self-evaluations, stress and work aspirations of Department of Education officers in selected districts in the Eastern Cape
- Authors: Gabelana, Nomzamo
- Date: 2014
- Language: English
- Type: Thesis , Masters , MCom (Industrial Psychology)
- Identifier: http://hdl.handle.net/10353/944 , vital:26511
- Description: The aim of the study was to investigate the effects of core self-evaluations and stress on the aspiration levels of the Department of Education (DoE) officers. An additional interest was on checking if general relationships amongst the three variables exist and the magnitude of such relationships. A literature study was conducted on three aspects, which are core self-evaluations, stress and work aspirations. This was followed by a survey involving 250 education specialists from four selected districts in the Eastern Cape, which are, Dutywa, Butterworth, Fort Beaufort and Mthatha. Results of the current research indicated that there is a positive relationship between core self-evaluation and DoE stress levels (r=0.32409; p=0.0014). These findings indicate that some individuals have low core self-evaluations due to their exposure to stressful situations hence they negatively appraise themselves and are less confident of themselves. DoE Senior Management Team (SMT) has to strategise and adopt measures that reduce stress levels and encourage positive CSE so as to deal effectively with under-performance.
- Full Text:
- Authors: Gabelana, Nomzamo
- Date: 2014
- Language: English
- Type: Thesis , Masters , MCom (Industrial Psychology)
- Identifier: http://hdl.handle.net/10353/944 , vital:26511
- Description: The aim of the study was to investigate the effects of core self-evaluations and stress on the aspiration levels of the Department of Education (DoE) officers. An additional interest was on checking if general relationships amongst the three variables exist and the magnitude of such relationships. A literature study was conducted on three aspects, which are core self-evaluations, stress and work aspirations. This was followed by a survey involving 250 education specialists from four selected districts in the Eastern Cape, which are, Dutywa, Butterworth, Fort Beaufort and Mthatha. Results of the current research indicated that there is a positive relationship between core self-evaluation and DoE stress levels (r=0.32409; p=0.0014). These findings indicate that some individuals have low core self-evaluations due to their exposure to stressful situations hence they negatively appraise themselves and are less confident of themselves. DoE Senior Management Team (SMT) has to strategise and adopt measures that reduce stress levels and encourage positive CSE so as to deal effectively with under-performance.
- Full Text:
Determinants of rural households’ diversification of livelihood strategies: a case of Intsika Yethu farmers of the Eastern Cape province, South Africa
- Authors: Munhenga, Daniel
- Date: 2014
- Subjects: Sustainable development -- South Africa -- Eastern Cape , Economic development projects -- South Africa -- Eastern Cape , Farm management -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc Agric (Agricultural Economics)
- Identifier: vital:11220 , http://hdl.handle.net/10353/d1019818 , Sustainable development -- South Africa -- Eastern Cape , Economic development projects -- South Africa -- Eastern Cape , Farm management -- South Africa -- Eastern Cape
- Description: Despite the continuing perceived economic centrality of agriculture in Intsika Yethu local municipality, rural households engage and pursue diverse non-farm livelihood activities to cope with diverse challenges and risks such as drought. This study assessed the importance of existing livelihood strategies adopted by the different rural households in Intsika Yethu; the link between households’ ownership and access to different ‘assets’; factors determining households’ ability to adopt certain livelihood strategies in the area. A survey of 120 households in six administrative areas and informal discussions with key informants were used to collect demographic data, data on socio-economic activities and factors determining the choice of livelihood strategies of the households in Intsika Yethu. The research findings indicated that only about 10% of the interviewed households relied solely on on-farm livelihood strategy only. Credit, remittances, market distance, affiliating to cooperatives, education and household size have a potential of influencing households to shift from on-farm livelihood strategy to other livelihood strategies. The government may need to promote programs and awareness on how households can diversify their livelihood strategies as a way of coping with economic constraints in the area.
- Full Text:
- Authors: Munhenga, Daniel
- Date: 2014
- Subjects: Sustainable development -- South Africa -- Eastern Cape , Economic development projects -- South Africa -- Eastern Cape , Farm management -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc Agric (Agricultural Economics)
- Identifier: vital:11220 , http://hdl.handle.net/10353/d1019818 , Sustainable development -- South Africa -- Eastern Cape , Economic development projects -- South Africa -- Eastern Cape , Farm management -- South Africa -- Eastern Cape
- Description: Despite the continuing perceived economic centrality of agriculture in Intsika Yethu local municipality, rural households engage and pursue diverse non-farm livelihood activities to cope with diverse challenges and risks such as drought. This study assessed the importance of existing livelihood strategies adopted by the different rural households in Intsika Yethu; the link between households’ ownership and access to different ‘assets’; factors determining households’ ability to adopt certain livelihood strategies in the area. A survey of 120 households in six administrative areas and informal discussions with key informants were used to collect demographic data, data on socio-economic activities and factors determining the choice of livelihood strategies of the households in Intsika Yethu. The research findings indicated that only about 10% of the interviewed households relied solely on on-farm livelihood strategy only. Credit, remittances, market distance, affiliating to cooperatives, education and household size have a potential of influencing households to shift from on-farm livelihood strategy to other livelihood strategies. The government may need to promote programs and awareness on how households can diversify their livelihood strategies as a way of coping with economic constraints in the area.
- Full Text:
Determinants of the yield curve in South Africa
- Authors: Ngonyama, Nomasomi
- Date: 2014
- Language: English
- Type: Thesis , Masters , M Com
- Identifier: vital:11496
- Description: The yield curve has been the subject of many studies for some time, mainly in predicting recessions, economic growth and inflation. However, scant work is available on what drives the yield spread. Given this, the paper examines the determinants of the yield curve in South Africa by using time series econometric analysis over the period 2000-2012. Some key variables considered include inflation, economic growth, budget deficit, and monetary policy. To separate the long and short run effects, VECM was employed after ensuring stationarity of the series. The study found that a long run relationship exist between the yield spread, inflation, GDP, budget deficit, Repo rate, Real effective exchange rate and a money supply (M1). The Results of this thesis have implications for policy and academic work.
- Full Text:
- Authors: Ngonyama, Nomasomi
- Date: 2014
- Language: English
- Type: Thesis , Masters , M Com
- Identifier: vital:11496
- Description: The yield curve has been the subject of many studies for some time, mainly in predicting recessions, economic growth and inflation. However, scant work is available on what drives the yield spread. Given this, the paper examines the determinants of the yield curve in South Africa by using time series econometric analysis over the period 2000-2012. Some key variables considered include inflation, economic growth, budget deficit, and monetary policy. To separate the long and short run effects, VECM was employed after ensuring stationarity of the series. The study found that a long run relationship exist between the yield spread, inflation, GDP, budget deficit, Repo rate, Real effective exchange rate and a money supply (M1). The Results of this thesis have implications for policy and academic work.
- Full Text:
Development of a bench scale single batch biomass to liquid fuel facility
- Authors: Zhang, Yusheng
- Date: 2014
- Subjects: Biomass energy , Renewable energy sources , Energy conversion , Electric power production
- Language: English
- Type: Thesis , Masters , MSc (Chemistry)
- Identifier: http://hdl.handle.net/10353/811 , vital:26499 , Biomass energy , Renewable energy sources , Energy conversion , Electric power production
- Description: The research described in this dissertation was motivated by the global demand for energy that is not dependent on coal, oil, natural gas and other non-renewable fossil fuels. The technology used in this project is related to the use of biomass to produce a viable alternative to conventional sources of fuel. A bench scale biomass to liquid (BTL) facility was built and tested. This produced results confirming the feasibility of the BTL process. The findings of the pilot study outlined in this dissertation justified the conclusion that the next step will be to expand the capacity and productivity of the BTL pilot plant to an industrial scale. Biomass comes from a variety of renewable sources that are readily available. In this case, the material used in the fixed bed biomass gasification facility to generate wood gas was agricultural and forestry waste, such as straw and wood chips. The gasifier had the capacity to produce up to 10 cubic metres/hr of gas with a carbon monoxide and hydrogen content of between 20–40% by volume, when it was operated at ambient pressure and with air as the oxidizer. The gas, produced at a temperature above 700º C, was cooled in a quench/water scrubber in order to remove most of the mechanical impurities (tars and water-soluble inorganic particles), condensed and dried with corn cobs before being compressed in cylinders at over 100 bar (g) for use in the Fischer-Tropsch Synthesis (FTS). The syngas was subjected further to a series of refining processes which included removal of sulphur and oxygen. The sulphur removal technology chosen entailed applying modified activated carbon to adsorb H2S with the help of hydrolysis in order to convert organic sulphur impurities into H2S which reduced the sulphur content of the gas to less than 5 ppbv. Supported cobalt catalyst (100 grams), were loaded into a single-tube fixed bed FT reactor with an inner diameter of 50 mm. The reactor was fitted with a heating jacket through which, heated oil ran to cool the reactor during a normal reaction occurring at < 250 ºC, while nitrogen was used in the heating jacket during reduction, which occurred at temperatures up ~ 350 ºC. The FTS reaction was carried out at different pressures and temperatures. Liquid and wax products were produced from the facility. The properties of the liquid and solid hydrocarbons produced were found to be the same as FT products from other feed stocks, such as natural gas and coal.
- Full Text:
- Authors: Zhang, Yusheng
- Date: 2014
- Subjects: Biomass energy , Renewable energy sources , Energy conversion , Electric power production
- Language: English
- Type: Thesis , Masters , MSc (Chemistry)
- Identifier: http://hdl.handle.net/10353/811 , vital:26499 , Biomass energy , Renewable energy sources , Energy conversion , Electric power production
- Description: The research described in this dissertation was motivated by the global demand for energy that is not dependent on coal, oil, natural gas and other non-renewable fossil fuels. The technology used in this project is related to the use of biomass to produce a viable alternative to conventional sources of fuel. A bench scale biomass to liquid (BTL) facility was built and tested. This produced results confirming the feasibility of the BTL process. The findings of the pilot study outlined in this dissertation justified the conclusion that the next step will be to expand the capacity and productivity of the BTL pilot plant to an industrial scale. Biomass comes from a variety of renewable sources that are readily available. In this case, the material used in the fixed bed biomass gasification facility to generate wood gas was agricultural and forestry waste, such as straw and wood chips. The gasifier had the capacity to produce up to 10 cubic metres/hr of gas with a carbon monoxide and hydrogen content of between 20–40% by volume, when it was operated at ambient pressure and with air as the oxidizer. The gas, produced at a temperature above 700º C, was cooled in a quench/water scrubber in order to remove most of the mechanical impurities (tars and water-soluble inorganic particles), condensed and dried with corn cobs before being compressed in cylinders at over 100 bar (g) for use in the Fischer-Tropsch Synthesis (FTS). The syngas was subjected further to a series of refining processes which included removal of sulphur and oxygen. The sulphur removal technology chosen entailed applying modified activated carbon to adsorb H2S with the help of hydrolysis in order to convert organic sulphur impurities into H2S which reduced the sulphur content of the gas to less than 5 ppbv. Supported cobalt catalyst (100 grams), were loaded into a single-tube fixed bed FT reactor with an inner diameter of 50 mm. The reactor was fitted with a heating jacket through which, heated oil ran to cool the reactor during a normal reaction occurring at < 250 ºC, while nitrogen was used in the heating jacket during reduction, which occurred at temperatures up ~ 350 ºC. The FTS reaction was carried out at different pressures and temperatures. Liquid and wax products were produced from the facility. The properties of the liquid and solid hydrocarbons produced were found to be the same as FT products from other feed stocks, such as natural gas and coal.
- Full Text:
Development of an M-commerce security framework
- Murufu, Mufudzi Anesu Chapman
- Authors: Murufu, Mufudzi Anesu Chapman
- Date: 2014
- Subjects: Mobile commerce , Telecommunication systems
- Language: English
- Type: Thesis , Masters , MSc (Computer Science)
- Identifier: http://hdl.handle.net/10353/833 , vital:26501 , Mobile commerce , Telecommunication systems
- Description: Research shows how M-Commerce has managed to find its way to previously inaccessible parts of the world as a major Information and Communication Technologies (ICT) tool for development due to widespread introduction of mobile phones in remote areas. M-Commerce has offered valuable advantages: anytime, anywhere, more personal, more location-aware, more context-aware, more age aware, always online and instant connectivity. But this is not without its problems, of which security is high on the list. The security issues span the whole M-Commerce spectrum, from the top to the bottom layer of the OSI network protocol stack, from machines to humans. This research proposes a threat-mitigation modular framework to help address the security issues lurking in M-Commerce systems being used by marginalised rural community members. The research commences with a literature survey carried out to establish security aspects related to M-Commerce and to determine requirements for a security framework. The framework classifies M-Commerce security threat-vulnerability-risks into four levels: human behaviour and mobile device interaction security, mobile device security, M-Commerce access channel security, wireless network access security. This is followed by a review of the supporting structures or related frameworks that the proposed framework could leverage to address security issues on M-Commerce systems as ICT4D initiatives. The proposed security framework based on the requirements discovered is then presented. As a proof-of-concept, a case study was undertaken at the Siyakhula Living Lab at Dwesa in the Eastern Cape province of South Africa in order to validate the components of the proposed framework. Following the application of the framework in a case study, it can be argued that the proposed security framework allows for secure transacting by marginalised users using M-Commerce initiatives. The security framework is therefore useful in addressing the identified security requirements of M-Commerce in ICT4D contexts.
- Full Text:
- Authors: Murufu, Mufudzi Anesu Chapman
- Date: 2014
- Subjects: Mobile commerce , Telecommunication systems
- Language: English
- Type: Thesis , Masters , MSc (Computer Science)
- Identifier: http://hdl.handle.net/10353/833 , vital:26501 , Mobile commerce , Telecommunication systems
- Description: Research shows how M-Commerce has managed to find its way to previously inaccessible parts of the world as a major Information and Communication Technologies (ICT) tool for development due to widespread introduction of mobile phones in remote areas. M-Commerce has offered valuable advantages: anytime, anywhere, more personal, more location-aware, more context-aware, more age aware, always online and instant connectivity. But this is not without its problems, of which security is high on the list. The security issues span the whole M-Commerce spectrum, from the top to the bottom layer of the OSI network protocol stack, from machines to humans. This research proposes a threat-mitigation modular framework to help address the security issues lurking in M-Commerce systems being used by marginalised rural community members. The research commences with a literature survey carried out to establish security aspects related to M-Commerce and to determine requirements for a security framework. The framework classifies M-Commerce security threat-vulnerability-risks into four levels: human behaviour and mobile device interaction security, mobile device security, M-Commerce access channel security, wireless network access security. This is followed by a review of the supporting structures or related frameworks that the proposed framework could leverage to address security issues on M-Commerce systems as ICT4D initiatives. The proposed security framework based on the requirements discovered is then presented. As a proof-of-concept, a case study was undertaken at the Siyakhula Living Lab at Dwesa in the Eastern Cape province of South Africa in order to validate the components of the proposed framework. Following the application of the framework in a case study, it can be argued that the proposed security framework allows for secure transacting by marginalised users using M-Commerce initiatives. The security framework is therefore useful in addressing the identified security requirements of M-Commerce in ICT4D contexts.
- Full Text:
Diet and microhabitat use of the woodland dormouse Graphiurus murinus at the Great Fish River Reserve, Eastern Cape, South Africa
- Authors: Lamani, Siviwe
- Date: 2014
- Language: English
- Type: Thesis , Masters , MSc (Zoology)
- Identifier: vital:11797 , http://hdl.handle.net/10353/d1019854
- Description: The diet of the woodland dormouse Graphiurus murinus was studied in a riverine Combretum forest at the Great Fish River Reserve (Eastern Cape, South Africa). Food remains were collected seasonally from a maximum of 45 different nest boxes between December 2010 and November 2011. An overall mean of 1.32 ± 0.51 food categories (range 1–4) were identified in each nest box used as “larder” during the year. Dietary diversity and standardized diet breadth were low to intermediate, with a peak in summer and a nadir in winter. In terms of percentage occurrence, arthropods were dominant (99%) in all seasons, followed by molluscs (16%) and fruits (14%). When relative percentage occurrence and percentage weight were considered, arthropods were still dominant, but a slight decrease was observed in summer. Besides spiders (order Araneae), nine arthropod families were found in the diet of the woodland dormouse; Tenebrionidae (40%), Spirostreptidae (30%), Carabidae (15%) and Blattidae (14%) were the most dominant families in terms of percentage weight. Grewia robusta and Ziziphus mucronata were the only fruit species present in the diet. Pianka’s diet overlap indices were very high (>0.93), indicating that the diet of the woodland dormouse was similar between pairs of seasons. This study also investigated whether woodland dormice Graphiurus murinus positively select or avoid specific microhabitat types or structures, and whether a set of predictor variables related to microhabitat characteristics can explain the presence and rates of visits to specific trapping stations. Trapping was conducted seasonally, over 5 days, between June 2011 and April 2012. A grid of 96 stations (16 rows × 6 lines) was established. Trap stations were set at 10-m intervals. At each station two Sherman traps were placed. The 192 traps were distributed relatively equitably among four height categories (0–0.5 m, 0.51–1 m, 1.01–1.5 m, and 1.51–2.5 m). On average, trapping success was 4.70 ± 4.17 dormice per 100 traps. Dormice were trapped at an average height of 136 ± 64 cm, which was significantly higher than the average height at which traps were set (99 ± 75 cm). Bonferroni Z tests indicated that dormice positively selected areas with high canopy cover and connectivity, possibly to decrease predation risk. Generalized Linear Models showed that trap use and numbers of visits and different animals caught were positively associated with a high arboreal connectivity, hence supporting the hypothesis that woodland dormice may depend on wooden “corridors” for their movements.
- Full Text:
- Authors: Lamani, Siviwe
- Date: 2014
- Language: English
- Type: Thesis , Masters , MSc (Zoology)
- Identifier: vital:11797 , http://hdl.handle.net/10353/d1019854
- Description: The diet of the woodland dormouse Graphiurus murinus was studied in a riverine Combretum forest at the Great Fish River Reserve (Eastern Cape, South Africa). Food remains were collected seasonally from a maximum of 45 different nest boxes between December 2010 and November 2011. An overall mean of 1.32 ± 0.51 food categories (range 1–4) were identified in each nest box used as “larder” during the year. Dietary diversity and standardized diet breadth were low to intermediate, with a peak in summer and a nadir in winter. In terms of percentage occurrence, arthropods were dominant (99%) in all seasons, followed by molluscs (16%) and fruits (14%). When relative percentage occurrence and percentage weight were considered, arthropods were still dominant, but a slight decrease was observed in summer. Besides spiders (order Araneae), nine arthropod families were found in the diet of the woodland dormouse; Tenebrionidae (40%), Spirostreptidae (30%), Carabidae (15%) and Blattidae (14%) were the most dominant families in terms of percentage weight. Grewia robusta and Ziziphus mucronata were the only fruit species present in the diet. Pianka’s diet overlap indices were very high (>0.93), indicating that the diet of the woodland dormouse was similar between pairs of seasons. This study also investigated whether woodland dormice Graphiurus murinus positively select or avoid specific microhabitat types or structures, and whether a set of predictor variables related to microhabitat characteristics can explain the presence and rates of visits to specific trapping stations. Trapping was conducted seasonally, over 5 days, between June 2011 and April 2012. A grid of 96 stations (16 rows × 6 lines) was established. Trap stations were set at 10-m intervals. At each station two Sherman traps were placed. The 192 traps were distributed relatively equitably among four height categories (0–0.5 m, 0.51–1 m, 1.01–1.5 m, and 1.51–2.5 m). On average, trapping success was 4.70 ± 4.17 dormice per 100 traps. Dormice were trapped at an average height of 136 ± 64 cm, which was significantly higher than the average height at which traps were set (99 ± 75 cm). Bonferroni Z tests indicated that dormice positively selected areas with high canopy cover and connectivity, possibly to decrease predation risk. Generalized Linear Models showed that trap use and numbers of visits and different animals caught were positively associated with a high arboreal connectivity, hence supporting the hypothesis that woodland dormice may depend on wooden “corridors” for their movements.
- Full Text:
Diet of the yellow mongoose (Cynictis penicillata) in the Albany Thicket Biome of South Africa
- Authors: Bizani, Mfundo
- Date: 2014
- Language: English
- Type: Thesis , Masters , MSc (Zoology)
- Identifier: vital:11796 , http://hdl.handle.net/10353/d1019840
- Description: The dietary habits of the yellow mongoose Cynictis penicillata were studied in the Albany Thicket Biome of South Africa (Great Fish River Reserve, Eastern Cape). The diet was investigated through the analysis of 1,056 scats that were sampled over a period of 7 years (2005−2009 and 2011−2012) mainly in three similar sites (Kelarny, Grasslands and Junction 10) that were used by at least three families or groups of yellow mongooses. Scats were collected near latrine sites, labelled and stored in a freezer. In the laboratory, scats were oven dried for a period of 24 hours at 50 C. Diet was determined by identifying undigested food remains in the scats. Hair samples were examined under the compound microscope to identify which mammals were ingested. In the field, both arthropod and small mammal abundance were determined in order to evaluate whether yellow mongooses are opportunistic or specialist feeders. Furthermore, inter-annual (2006–2008) and inter-group/inter-site variations in the diet were assessed. Based on faecal analysis, arthropods were the principal prey, while small mammals acted as supplementary food item. Other food categories like vegetation, reptiles and birds were only ingested or preyed upon infrequently. Intermediate dietary diversity, and low standardised diet breadth indices were obtained for all seasons, as well as for the whole sampling period. The diet overlaps calculated for pairs of seasons were very high and did not differ substantially. However, the diet of the yellow mongoose varied seasonally, yearly and between groups (sites), mostly due to variations in arthropod and small mammal consumption. Food availability displayed an increase in biomass of both small mammals and arthropods in summer and autumn. Results obtained in this study could suggest that the yellow mongoose at the GFRR is insectivorous by preferring to feed on insects (and arthropods in general) when both insects and rodents are abundant. However the fact that its diet varies both seasonally, yearly and locally, as well as the presence of remains of other food categories in the scats, indicates that this species is rather an opportunistic, generalist feeder than an insect specialist.
- Full Text:
- Authors: Bizani, Mfundo
- Date: 2014
- Language: English
- Type: Thesis , Masters , MSc (Zoology)
- Identifier: vital:11796 , http://hdl.handle.net/10353/d1019840
- Description: The dietary habits of the yellow mongoose Cynictis penicillata were studied in the Albany Thicket Biome of South Africa (Great Fish River Reserve, Eastern Cape). The diet was investigated through the analysis of 1,056 scats that were sampled over a period of 7 years (2005−2009 and 2011−2012) mainly in three similar sites (Kelarny, Grasslands and Junction 10) that were used by at least three families or groups of yellow mongooses. Scats were collected near latrine sites, labelled and stored in a freezer. In the laboratory, scats were oven dried for a period of 24 hours at 50 C. Diet was determined by identifying undigested food remains in the scats. Hair samples were examined under the compound microscope to identify which mammals were ingested. In the field, both arthropod and small mammal abundance were determined in order to evaluate whether yellow mongooses are opportunistic or specialist feeders. Furthermore, inter-annual (2006–2008) and inter-group/inter-site variations in the diet were assessed. Based on faecal analysis, arthropods were the principal prey, while small mammals acted as supplementary food item. Other food categories like vegetation, reptiles and birds were only ingested or preyed upon infrequently. Intermediate dietary diversity, and low standardised diet breadth indices were obtained for all seasons, as well as for the whole sampling period. The diet overlaps calculated for pairs of seasons were very high and did not differ substantially. However, the diet of the yellow mongoose varied seasonally, yearly and between groups (sites), mostly due to variations in arthropod and small mammal consumption. Food availability displayed an increase in biomass of both small mammals and arthropods in summer and autumn. Results obtained in this study could suggest that the yellow mongoose at the GFRR is insectivorous by preferring to feed on insects (and arthropods in general) when both insects and rodents are abundant. However the fact that its diet varies both seasonally, yearly and locally, as well as the presence of remains of other food categories in the scats, indicates that this species is rather an opportunistic, generalist feeder than an insect specialist.
- Full Text:
Educators’ perceptions of foundation phase mathematics Curriculum Assessment Policy Statements (CAPS)
- Authors: Mnqatu, Fiola Wayne
- Date: 2014
- Subjects: Curriculum evaluation -- South Africa , Curriculum planning -- South Africa , Mathematics -- Study and teaching --South Africa
- Language: English
- Type: Thesis , Masters , M Ed
- Identifier: http://hdl.handle.net/10353/1358 , vital:26549 , Curriculum evaluation -- South Africa , Curriculum planning -- South Africa , Mathematics -- Study and teaching --South Africa
- Description: The aim of the study was to investigate the educators’ perceptions of the Foundation Phase Mathematics Curriculum Assessment Policy Statements (CAPS). This was a case study of eight educators in two primary schools based in Cradock in the Eastern Cape Province of South Africa. There were six main findings. First, all participants displayed a good general knowledge of CAPS. They saw CAPS as different from NCS in that the former is content driven as opposed to outcomes driven in the latter. Second, all participants were happy that CAPS specifies what is to be taught grade by grade as opposed to NCS which specified outcomes and required educators to construct the content. Third, a feature which participants liked was the weighting of different components of the subjects taught. This was seen as an important guideline that indicates how much time should be spent on each component. Fourth, participants understood that CAPS is not a new curriculum; it is an amendment of the NCS. As such educators used the same teaching strategies and methods. Fifth, participants had reservations about the CAPS assessment guidelines as they were the same as those of the NCS and felt that the guidelines which require educators to discuss assessment criteria with children were not suitable for children in Foundation Phase. Sixth, participants were happy with the CAPS programme of assessment and workbooks .They felt the programme guides their teaching while the workbooks complement their teaching. It can be concluded that educators, on the whole, held positive perceptions about CAPS. They saw it as explicit about the content that is to be taught, and it has clear guidelines about assessment procedures. For this reason it can be seen as an improvement on the NCS. Given the findings, it can be recommended that further research be carried out on how educators’ understanding of CAPS is translated into practical teaching and learning in the classroom. To improve the delivery of CAPS, the Education Department must devise strategies aimed at educator empowerment activities that will enhance their work performance.
- Full Text:
- Authors: Mnqatu, Fiola Wayne
- Date: 2014
- Subjects: Curriculum evaluation -- South Africa , Curriculum planning -- South Africa , Mathematics -- Study and teaching --South Africa
- Language: English
- Type: Thesis , Masters , M Ed
- Identifier: http://hdl.handle.net/10353/1358 , vital:26549 , Curriculum evaluation -- South Africa , Curriculum planning -- South Africa , Mathematics -- Study and teaching --South Africa
- Description: The aim of the study was to investigate the educators’ perceptions of the Foundation Phase Mathematics Curriculum Assessment Policy Statements (CAPS). This was a case study of eight educators in two primary schools based in Cradock in the Eastern Cape Province of South Africa. There were six main findings. First, all participants displayed a good general knowledge of CAPS. They saw CAPS as different from NCS in that the former is content driven as opposed to outcomes driven in the latter. Second, all participants were happy that CAPS specifies what is to be taught grade by grade as opposed to NCS which specified outcomes and required educators to construct the content. Third, a feature which participants liked was the weighting of different components of the subjects taught. This was seen as an important guideline that indicates how much time should be spent on each component. Fourth, participants understood that CAPS is not a new curriculum; it is an amendment of the NCS. As such educators used the same teaching strategies and methods. Fifth, participants had reservations about the CAPS assessment guidelines as they were the same as those of the NCS and felt that the guidelines which require educators to discuss assessment criteria with children were not suitable for children in Foundation Phase. Sixth, participants were happy with the CAPS programme of assessment and workbooks .They felt the programme guides their teaching while the workbooks complement their teaching. It can be concluded that educators, on the whole, held positive perceptions about CAPS. They saw it as explicit about the content that is to be taught, and it has clear guidelines about assessment procedures. For this reason it can be seen as an improvement on the NCS. Given the findings, it can be recommended that further research be carried out on how educators’ understanding of CAPS is translated into practical teaching and learning in the classroom. To improve the delivery of CAPS, the Education Department must devise strategies aimed at educator empowerment activities that will enhance their work performance.
- Full Text:
Effect of irrigation farming potential on commercialization of smallholder farming in the Eastern Cape Province of South Africa
- Authors: Sipoko, Nomava
- Date: 2014
- Subjects: Irrigation farming -- South Africa -- Eastern Cape , Farms, Small -- South Africa -- Eastern Cape , Agriculture -- Economic aspects
- Language: English
- Type: Thesis , Masters , MSc Agric (Agricultural Economics)
- Identifier: vital:11218 , http://hdl.handle.net/10353/d1019772 , Irrigation farming -- South Africa -- Eastern Cape , Farms, Small -- South Africa -- Eastern Cape , Agriculture -- Economic aspects
- Description: Enhancement of smallholder production to improve rural livelihood is an important policy goal in developing countries. Research findings indicate that smallholder production can be improved through establishment of new smallholder irrigation schemes, and the rehabilitation of abandoned ones. Smallholder irrigation has a potential to contribute significantly in shifting smallholder farming to commercial farming. Although the roles of irrigating farmers are clearly defined, smallholder farmer’s development results in South Africa have been disappointing. The performance of smallholder irrigation is unsatisfactory. Smallholder irrigation has failed to improve the standard of living and livelihoods of smallholder farmers in South Africa. The majority of farmers are still producing at subsistence level. This study, therefore, aimed to contribute to smallholder irrigation literature in two ways; firstly by evaluating the extent of irrigation participation of smallholder farmers towards commercialization in the study areas. The study also examined the determinants of irrigation participation among smallholder farmers. A sample of 80 households was drawn by random sampling of smallholders in four villages as follows: 40 respondents from Mgxabakazi and Dinizulu villages and 40 respondents from Ncorha flats and Tshatshu. The sample included both irrigators and non-irrigators. Descriptive analysis shows that irrigators had better production and wellbeing than non-irrigators. For the inferential analysis of the data, two models were employed namely, Binary Logistic Regression Model (BRM) and Truncated Regression Model (TRM). The Binary Regression model was used to predict the probability of farmers participating in irrigation schemes. Whether or not a farmer participated in irrigation was introduced as the binary dependent or response variable that could be explained by a range of explanatory or predictor variables such as source of water, land size, ability to sustain business, membership in the scheme, market access, availability of the irrigation system, willingness to irrigate, farming type commercial or subsistence and institutional support services. From these predictor variables, being part of the irrigation, ability to sustain business and market were found to be factors influencing farmer’s decision to participate. The second model required the in-depth investigation of the influence of irrigation participation as reflected by extent of commercialization. In order to do this, the level of commercialization was measured by calculating Household Commercialization Index. Then the truncated regression model (TR) was used to test the factors that affect the level of commercialization for the farmers who are participating in the irrigation schemes.Age, irrigated land, willingness to commercialize and gross value of production were found to exert strong influence on the level of commercialization among farmers participating in irrigation. The study recommends that investments in smallholder irrigation should receive high priority, with emphasis on collective action, promotion of contract farming and strengthening the support services from government and the private sector, and ensuring enhanced access to market to all farmers.
- Full Text:
- Authors: Sipoko, Nomava
- Date: 2014
- Subjects: Irrigation farming -- South Africa -- Eastern Cape , Farms, Small -- South Africa -- Eastern Cape , Agriculture -- Economic aspects
- Language: English
- Type: Thesis , Masters , MSc Agric (Agricultural Economics)
- Identifier: vital:11218 , http://hdl.handle.net/10353/d1019772 , Irrigation farming -- South Africa -- Eastern Cape , Farms, Small -- South Africa -- Eastern Cape , Agriculture -- Economic aspects
- Description: Enhancement of smallholder production to improve rural livelihood is an important policy goal in developing countries. Research findings indicate that smallholder production can be improved through establishment of new smallholder irrigation schemes, and the rehabilitation of abandoned ones. Smallholder irrigation has a potential to contribute significantly in shifting smallholder farming to commercial farming. Although the roles of irrigating farmers are clearly defined, smallholder farmer’s development results in South Africa have been disappointing. The performance of smallholder irrigation is unsatisfactory. Smallholder irrigation has failed to improve the standard of living and livelihoods of smallholder farmers in South Africa. The majority of farmers are still producing at subsistence level. This study, therefore, aimed to contribute to smallholder irrigation literature in two ways; firstly by evaluating the extent of irrigation participation of smallholder farmers towards commercialization in the study areas. The study also examined the determinants of irrigation participation among smallholder farmers. A sample of 80 households was drawn by random sampling of smallholders in four villages as follows: 40 respondents from Mgxabakazi and Dinizulu villages and 40 respondents from Ncorha flats and Tshatshu. The sample included both irrigators and non-irrigators. Descriptive analysis shows that irrigators had better production and wellbeing than non-irrigators. For the inferential analysis of the data, two models were employed namely, Binary Logistic Regression Model (BRM) and Truncated Regression Model (TRM). The Binary Regression model was used to predict the probability of farmers participating in irrigation schemes. Whether or not a farmer participated in irrigation was introduced as the binary dependent or response variable that could be explained by a range of explanatory or predictor variables such as source of water, land size, ability to sustain business, membership in the scheme, market access, availability of the irrigation system, willingness to irrigate, farming type commercial or subsistence and institutional support services. From these predictor variables, being part of the irrigation, ability to sustain business and market were found to be factors influencing farmer’s decision to participate. The second model required the in-depth investigation of the influence of irrigation participation as reflected by extent of commercialization. In order to do this, the level of commercialization was measured by calculating Household Commercialization Index. Then the truncated regression model (TR) was used to test the factors that affect the level of commercialization for the farmers who are participating in the irrigation schemes.Age, irrigated land, willingness to commercialize and gross value of production were found to exert strong influence on the level of commercialization among farmers participating in irrigation. The study recommends that investments in smallholder irrigation should receive high priority, with emphasis on collective action, promotion of contract farming and strengthening the support services from government and the private sector, and ensuring enhanced access to market to all farmers.
- Full Text:
Effect of pre-slaughter stress of pigs on the levels of cortisol, creatine kinase and their subsequent relationship with pork quality
- Authors: Nzolo, Jama
- Date: 2014
- Subjects: Slaughtering and slaughter-houses , Pork -- Quality , Swine -- Handling , Livestock -- Handling , Creatine kinase
- Language: English
- Type: Thesis , Masters , MSc Agric (Animal Science)
- Identifier: vital:11837 , http://hdl.handle.net/10353/d1021287 , Slaughtering and slaughter-houses , Pork -- Quality , Swine -- Handling , Livestock -- Handling , Creatine kinase
- Description: The study was conducted to determine the effect of pre-slaughter stress of pigs on the levels of cortisol, creatine kinase (CK) and their subsequent relationship with pork quality. From our knowledge, there is paucity of information on transportation, lairage duration and sex effects on saliva cortisol and its relation with serum cortisol, urine cortisol and other meat quality traits. Stage one of the study assessed the effect of sex and time to slaughter (transport and lairage duration) on the levels of cortisol and CK in crossbred pigs. The second stage of the study evaluated the effect of sex and lairage duration on pork quality. The trials comprised of 60 22-weeks old commercial crossbred pigs [(30 boars vs. 30 gilts) with an average body weight of 76.9kg for gilts and 78.3kg for boars. Thirty pigs (15 Boars vs. 15 Gilts) were slaughtered on arrival after a 120km road journey and the other 30, after travelling the same road and distance, were slaughtered after having been in the lairage for 20 hours. Saliva samples were obtained during three time periods: between 07:00-10:00 on the day before the journey, on arrival at the abattoir and after lairage. Levels of cortisol in serum and urine and CK in serum samples collected at slaughter were determined. The samples (saliva and serum) were centrifuged at 20oC for 10 min at 3550 x g and stored at -20oC in separate vials until analysis. Pork quality was assessed using muscle pH, colour, thawing and cooking losses and Warner-Bratzler Shear Force. Correlations between cortisol levels in saliva, serum and urine and meat quality were assessed. The effect of sex and time to slaughter on saliva cortisol was significant. Statistical analysis showed significant interaction of sex by time to slaughter on serum cortisol. It was only the effect of sex that demonstrated higher (P <0.05) serum creatine kinase levels in gilts. Likewise, urine cortisol was influenced (P <0.05) only by time to slaughter. Saliva cortisol after transportation (r = 0.52) was correlated (P <0.05) with urine cortisol. The study suggests that there are greater responses of the Hypothalamic-pituitary-adrenal axis following time to slaughter (transport and lairage duration) between gilts and boars. This can be used in measuring cortisol in saliva, serum and urine, and serum creatine kinase to determine stress levels in pigs. Besides the lightness (L*) colour value which was significantly lower (P <0.05) in meat from gilts than from boars, the results of this study showed no interaction or individual effect (sex or lairage duration) on pH and other colour measurements. Meat cooking loss was affected (P <0.05) by gender x lairage interaction. Effect of lairage duration (as an individual effect) on the measured meat quality traits was not significant (P <0.05). Correlation analysis showed significant (P <0.05) negative relation between baseline saliva cortisol (r = -0.40) and the pork L* value. Saliva cortisol after lairage duration (r = -0.38 and r = 0.38) was correlated (P <0.05) with pH45 and pork a* value, respectively. Serum cortisol (r = -0.35) was negatively correlated (P <0.05) with pH45. Moreover, there were negative correlations (P <0.05) between saliva cortisol after transportation (r = -0.35), saliva cortisol after lairage duration (r = -0.44), serum cortisol (r = -0.40) and meat cooking loss. The study suggests that cortisol in saliva and serum can be used to determine effect of time to slaughter (transport and lairage duration) on meat quality traits from gilts and boars. Keywords: Boars; gilts; saliva cortisol; serum cortisol; serum creatine kinase; urine cortisol.
- Full Text:
- Authors: Nzolo, Jama
- Date: 2014
- Subjects: Slaughtering and slaughter-houses , Pork -- Quality , Swine -- Handling , Livestock -- Handling , Creatine kinase
- Language: English
- Type: Thesis , Masters , MSc Agric (Animal Science)
- Identifier: vital:11837 , http://hdl.handle.net/10353/d1021287 , Slaughtering and slaughter-houses , Pork -- Quality , Swine -- Handling , Livestock -- Handling , Creatine kinase
- Description: The study was conducted to determine the effect of pre-slaughter stress of pigs on the levels of cortisol, creatine kinase (CK) and their subsequent relationship with pork quality. From our knowledge, there is paucity of information on transportation, lairage duration and sex effects on saliva cortisol and its relation with serum cortisol, urine cortisol and other meat quality traits. Stage one of the study assessed the effect of sex and time to slaughter (transport and lairage duration) on the levels of cortisol and CK in crossbred pigs. The second stage of the study evaluated the effect of sex and lairage duration on pork quality. The trials comprised of 60 22-weeks old commercial crossbred pigs [(30 boars vs. 30 gilts) with an average body weight of 76.9kg for gilts and 78.3kg for boars. Thirty pigs (15 Boars vs. 15 Gilts) were slaughtered on arrival after a 120km road journey and the other 30, after travelling the same road and distance, were slaughtered after having been in the lairage for 20 hours. Saliva samples were obtained during three time periods: between 07:00-10:00 on the day before the journey, on arrival at the abattoir and after lairage. Levels of cortisol in serum and urine and CK in serum samples collected at slaughter were determined. The samples (saliva and serum) were centrifuged at 20oC for 10 min at 3550 x g and stored at -20oC in separate vials until analysis. Pork quality was assessed using muscle pH, colour, thawing and cooking losses and Warner-Bratzler Shear Force. Correlations between cortisol levels in saliva, serum and urine and meat quality were assessed. The effect of sex and time to slaughter on saliva cortisol was significant. Statistical analysis showed significant interaction of sex by time to slaughter on serum cortisol. It was only the effect of sex that demonstrated higher (P <0.05) serum creatine kinase levels in gilts. Likewise, urine cortisol was influenced (P <0.05) only by time to slaughter. Saliva cortisol after transportation (r = 0.52) was correlated (P <0.05) with urine cortisol. The study suggests that there are greater responses of the Hypothalamic-pituitary-adrenal axis following time to slaughter (transport and lairage duration) between gilts and boars. This can be used in measuring cortisol in saliva, serum and urine, and serum creatine kinase to determine stress levels in pigs. Besides the lightness (L*) colour value which was significantly lower (P <0.05) in meat from gilts than from boars, the results of this study showed no interaction or individual effect (sex or lairage duration) on pH and other colour measurements. Meat cooking loss was affected (P <0.05) by gender x lairage interaction. Effect of lairage duration (as an individual effect) on the measured meat quality traits was not significant (P <0.05). Correlation analysis showed significant (P <0.05) negative relation between baseline saliva cortisol (r = -0.40) and the pork L* value. Saliva cortisol after lairage duration (r = -0.38 and r = 0.38) was correlated (P <0.05) with pH45 and pork a* value, respectively. Serum cortisol (r = -0.35) was negatively correlated (P <0.05) with pH45. Moreover, there were negative correlations (P <0.05) between saliva cortisol after transportation (r = -0.35), saliva cortisol after lairage duration (r = -0.44), serum cortisol (r = -0.40) and meat cooking loss. The study suggests that cortisol in saliva and serum can be used to determine effect of time to slaughter (transport and lairage duration) on meat quality traits from gilts and boars. Keywords: Boars; gilts; saliva cortisol; serum cortisol; serum creatine kinase; urine cortisol.
- Full Text:
Effects of dietary inclusion of Moringa oleifera leaf meal on growth performance, physico-chemical attributes, oxidative stability and sensory quality of pork
- Authors: Nduku, Xola Pauline
- Date: 2014
- Subjects: Pork -- Quality , Food -- Sensory evaluation , Fatty acids , Moringa , Meat -- Quality
- Language: English
- Type: Thesis , Masters , MSc Agric (Animal Science)
- Identifier: vital:11836 , http://hdl.handle.net/10353/d1021281 , Pork -- Quality , Food -- Sensory evaluation , Fatty acids , Moringa , Meat -- Quality
- Description: The objective of the study was to determine growth performance, physico-chemical attributes, oxidative stability and sensory quality of pork from pigs fed one of three dietary treatments, eac containing 0%, 2.5% or 5% (T1, T2 and T3, respectively) Moringa oleifera leaf meal (MOLM). Dietary treatments were formulated to be isonitrogenous and isoenergetic for weaner (6 – 8 weeks) and grower (9 – 13 weeks) phases. Twelve Large White (LW) and 12 Kolbroek (KB) male pigs at 6 weeks of age, initially weighing an average 10 kg, were randomly allocated to one of the dietary treatments, each with four replicates, in individual pens. Feed and water were offered ad libitum. The Longissimus thoracis et lumborum (LTL) muscle of each carcass (n = 24) was sampled for meat quality and fatty acid analyses. Breed differences in measured parameters were observed. In pigs receiving 5% MOLM, the LW had significantly the highest ADFI (P<0.05) than KB pigs. In pigs receiving 2.5% and 5% MOLM, backfat thickness was significantly highest (P<0.05) compared to those receiving 0% MOML. Dietary inclusion of MOLM had no significant effects (P>0.05) on the physico-chemical quality of pork from LW pigs; although it significantly (P<0.05) increased a* and reduced WBSF values in pork from KB pigs. Pork from LW pigs receiving 5% MOLM had significantly increased (P<0.05) n-3 content of the subcutaneous tissue of LW pigs compared to KB, and also when compread to other treatment groups. In both breeds, the composition of PUFA: SFA and n-6: n-3 in the subcutaneous adipose tissue was significantly (P<0.05) lower in T2 and T3 than in T1. The n-3 levels for pork muscle from LW pigs receiving 2.5% and 5% MOLM, and from KB pigs receiving 5% MOLM, were significantly (P<0.05) lower. Inclusions of MOLM significantly (P<0.05) reduced the n-6: n-3 fatty acids in pork from both LW pigs and KB pigs. Consumer scores on sensory attributes (aroma intensity, initial impression of juiciness, first bite, sustained impression of juiciness, muscle fibre and overall tenderness and overall flavor intensity) significantly (P<0.05) increased as the level of MOLM inclusion in the diet increased; and higher scores were observed in fried meat than in boiled for most sensory attributes. It may be concluded that inclusion of MOLM in pig diets up to 5% improved the ADFI, a*, tenderness of pork without adversely affecting the FCR and other physico-chemical quality attributes; and resulted in desired increase in levels of n-3 and reduced the n-6: n-3 fatty acid ratio.
- Full Text:
- Authors: Nduku, Xola Pauline
- Date: 2014
- Subjects: Pork -- Quality , Food -- Sensory evaluation , Fatty acids , Moringa , Meat -- Quality
- Language: English
- Type: Thesis , Masters , MSc Agric (Animal Science)
- Identifier: vital:11836 , http://hdl.handle.net/10353/d1021281 , Pork -- Quality , Food -- Sensory evaluation , Fatty acids , Moringa , Meat -- Quality
- Description: The objective of the study was to determine growth performance, physico-chemical attributes, oxidative stability and sensory quality of pork from pigs fed one of three dietary treatments, eac containing 0%, 2.5% or 5% (T1, T2 and T3, respectively) Moringa oleifera leaf meal (MOLM). Dietary treatments were formulated to be isonitrogenous and isoenergetic for weaner (6 – 8 weeks) and grower (9 – 13 weeks) phases. Twelve Large White (LW) and 12 Kolbroek (KB) male pigs at 6 weeks of age, initially weighing an average 10 kg, were randomly allocated to one of the dietary treatments, each with four replicates, in individual pens. Feed and water were offered ad libitum. The Longissimus thoracis et lumborum (LTL) muscle of each carcass (n = 24) was sampled for meat quality and fatty acid analyses. Breed differences in measured parameters were observed. In pigs receiving 5% MOLM, the LW had significantly the highest ADFI (P<0.05) than KB pigs. In pigs receiving 2.5% and 5% MOLM, backfat thickness was significantly highest (P<0.05) compared to those receiving 0% MOML. Dietary inclusion of MOLM had no significant effects (P>0.05) on the physico-chemical quality of pork from LW pigs; although it significantly (P<0.05) increased a* and reduced WBSF values in pork from KB pigs. Pork from LW pigs receiving 5% MOLM had significantly increased (P<0.05) n-3 content of the subcutaneous tissue of LW pigs compared to KB, and also when compread to other treatment groups. In both breeds, the composition of PUFA: SFA and n-6: n-3 in the subcutaneous adipose tissue was significantly (P<0.05) lower in T2 and T3 than in T1. The n-3 levels for pork muscle from LW pigs receiving 2.5% and 5% MOLM, and from KB pigs receiving 5% MOLM, were significantly (P<0.05) lower. Inclusions of MOLM significantly (P<0.05) reduced the n-6: n-3 fatty acids in pork from both LW pigs and KB pigs. Consumer scores on sensory attributes (aroma intensity, initial impression of juiciness, first bite, sustained impression of juiciness, muscle fibre and overall tenderness and overall flavor intensity) significantly (P<0.05) increased as the level of MOLM inclusion in the diet increased; and higher scores were observed in fried meat than in boiled for most sensory attributes. It may be concluded that inclusion of MOLM in pig diets up to 5% improved the ADFI, a*, tenderness of pork without adversely affecting the FCR and other physico-chemical quality attributes; and resulted in desired increase in levels of n-3 and reduced the n-6: n-3 fatty acid ratio.
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Effects of oats and vetch cover crops on light organic matter fractions and activities of selected enzymes in an irrigated maize based conservation agriculture system on Alice Jozini Ecotope in the Eastern Cape, South Africa
- Authors: Mukumbareza, Caroline
- Date: 2014
- Language: English
- Type: Thesis , Masters , MSc Agric (Crop Science)
- Identifier: vital:11872 , http://hdl.handle.net/10353/d1019815
- Description: Low soil fertility in the Eastern Cape Province (EC) is attributed to poor agricultural management, which reduces organic matter, among other factors. Conservation agriculture (CA), consisting of no-till, soil cover and rotations, is being promoted to improve soil quality and productivity. Soil biological parameters respond to the overall effects of management on the physical and chemical components of soil. This study was conducted to evaluate the effects of oat (Avena sativa) and grazing vetch (Vicia dasycarpa) cover crops on soil biological activity after five years under CA and evaluate light organic matter fractions, MBC and activities of selected enzymes as early indicators of organic matter build up under in no-till maize based CA system. The study was based on soil samples collected from a five year trial with rotations of maize and sole covercrops and two younger trials (4 and 28 months) with oat and grazing vetch bicultures. In the five year old trial, oat and grazing vetch were planted at four fertiliser regimes (i) Fertilizer applied to cover crops and maize (F1), (ii) fertilizer applied to cover crops only (F2), (iii) fertilizer applied to maize only (F3) and (iv) no fertilizer applied (F4)) to give a 2 × 4 factorial plus control laid out in a randomized complete block design (RCBD) with three replications. Fertilizer was applied at 10 kg P ha-1, as a compound (6.7% N; 10% P; 13.3% K) at planting and grazing vetch was inoculated with Rhizobium legunominosarium biovar viciae. Oat was top dressed using limestone ammonium nitrate (LAN – 28% N) at 7 weeks after planting (WAP) to make a total of 45 kg N ha-1. Three weeks after termination of the cover crops, all plots were split in half and maize was planted and fertilizer applied at 0 and 60 N kg ha-1. A third of the N was applied at planting (6.7% N; 10% P; 13.3% K). In the biculture trials, the treatments were 90% oat + 10% vetch, 70% oat + 30% vetch, 50% oat+ 50% vetch, 100% vetch and 100% oat and laid out in a RCBD with three replicates. Only basal fertilizer was applied to the cover crop at planting at 13.34 kg N ha-1, 20 kg P ha-1 and 26.66 kg K ha-1 using 2:3:4 (30 + 0.5% Zn) compound fertiliser. After cover crop termination, SC701 maize variety was planted, and fertilised at 60 kg N ha-1 with a third of the N applied as a basal. In the five year old trial, oat and vetch gave significantly (P < 0.05) higher MBC and activities of all soil enzymes measured than the weedy fallow at 0-5 and 5-20 cm depths. Fertilization of cover crop (F2) and maize (F3) gave similar MBC. The F4 in cover crops gave similar dehydrogenase activity with F3 under weedy fallow and that for vetch rotation was the same for F3 in oat. The F4 for grazing vetch had similar β-glucosidase activity as F1 and similar urease activity as F1, F2 and F3 of oat rotations. Acid and alkaline activity in F1 had similar results to F2. In the younger trials, biculture treatments did not improve total C, and N when compared with the weedy fallow. Dehydrogenase, β-glucosidase, arylsulphatase and alkaline phosphatase activities were higher in the 28 month trial compared to the 4 month one while urease was higher in the 4-month old trial. Treatments with more than 50% oat content had higher acid phosphatase activity in the 4- than 28 month old trial. Effects of cover crop, as the main factor, was significant in all enzymes (P < 0.05), with 70% oat + 30% vetch treatment having the highest dehydrogenase and arylsulphatase while for alkaline phosphatase it had similar results to 90% oat + 10% vetch. For β-glucosidase and urease, effects of cover crop as the main factor were also significant with sole vetch giving the highest activity for both enzymes. Acid phosphatase activity was highest in sole oat. Particulate OM was highest in the 100% oat treatment and declined with decrease in the proportion of oat in the biculture. The 50% oat + 50% vetch treatment had similar POM to the 70% oat +30% vetch in the 4 month old trial and to the 90% oat + 10% vetch in the 28 months old trial in the 0-5 cm depth (P < 0.05). In the 5-20 cm depth, the 70% oat +30% vetch treatment had similar POM to the 90% oat + 10% vetch in the 28 month old trial. The 70% oat+30% vetch had greatest WSC and MBC followed by the 90% oat +10% vetch, with the 50% oat + 50% vetch being similar to 100% vetch and 100% oat (MBC only). The 28 months old trial had greater POM and WSC than the 4 months trial. The findings of this study imply that the use of grazing vetch and fertilization of cover crops only improves soil biological activity, represented by MBC and enzyme activities, after 5 years of maize-cover crop rotations in low input conservation agriculture system. Bicultures, particularly the 70% oat + 30% vetch, work better than their sole crops in improving organic matter fractions, MBC and enzyme activities and that POM, WSC, MBC, enzyme activities are useful early indicators of soil organic matter build-up of CA systems.
- Full Text:
- Authors: Mukumbareza, Caroline
- Date: 2014
- Language: English
- Type: Thesis , Masters , MSc Agric (Crop Science)
- Identifier: vital:11872 , http://hdl.handle.net/10353/d1019815
- Description: Low soil fertility in the Eastern Cape Province (EC) is attributed to poor agricultural management, which reduces organic matter, among other factors. Conservation agriculture (CA), consisting of no-till, soil cover and rotations, is being promoted to improve soil quality and productivity. Soil biological parameters respond to the overall effects of management on the physical and chemical components of soil. This study was conducted to evaluate the effects of oat (Avena sativa) and grazing vetch (Vicia dasycarpa) cover crops on soil biological activity after five years under CA and evaluate light organic matter fractions, MBC and activities of selected enzymes as early indicators of organic matter build up under in no-till maize based CA system. The study was based on soil samples collected from a five year trial with rotations of maize and sole covercrops and two younger trials (4 and 28 months) with oat and grazing vetch bicultures. In the five year old trial, oat and grazing vetch were planted at four fertiliser regimes (i) Fertilizer applied to cover crops and maize (F1), (ii) fertilizer applied to cover crops only (F2), (iii) fertilizer applied to maize only (F3) and (iv) no fertilizer applied (F4)) to give a 2 × 4 factorial plus control laid out in a randomized complete block design (RCBD) with three replications. Fertilizer was applied at 10 kg P ha-1, as a compound (6.7% N; 10% P; 13.3% K) at planting and grazing vetch was inoculated with Rhizobium legunominosarium biovar viciae. Oat was top dressed using limestone ammonium nitrate (LAN – 28% N) at 7 weeks after planting (WAP) to make a total of 45 kg N ha-1. Three weeks after termination of the cover crops, all plots were split in half and maize was planted and fertilizer applied at 0 and 60 N kg ha-1. A third of the N was applied at planting (6.7% N; 10% P; 13.3% K). In the biculture trials, the treatments were 90% oat + 10% vetch, 70% oat + 30% vetch, 50% oat+ 50% vetch, 100% vetch and 100% oat and laid out in a RCBD with three replicates. Only basal fertilizer was applied to the cover crop at planting at 13.34 kg N ha-1, 20 kg P ha-1 and 26.66 kg K ha-1 using 2:3:4 (30 + 0.5% Zn) compound fertiliser. After cover crop termination, SC701 maize variety was planted, and fertilised at 60 kg N ha-1 with a third of the N applied as a basal. In the five year old trial, oat and vetch gave significantly (P < 0.05) higher MBC and activities of all soil enzymes measured than the weedy fallow at 0-5 and 5-20 cm depths. Fertilization of cover crop (F2) and maize (F3) gave similar MBC. The F4 in cover crops gave similar dehydrogenase activity with F3 under weedy fallow and that for vetch rotation was the same for F3 in oat. The F4 for grazing vetch had similar β-glucosidase activity as F1 and similar urease activity as F1, F2 and F3 of oat rotations. Acid and alkaline activity in F1 had similar results to F2. In the younger trials, biculture treatments did not improve total C, and N when compared with the weedy fallow. Dehydrogenase, β-glucosidase, arylsulphatase and alkaline phosphatase activities were higher in the 28 month trial compared to the 4 month one while urease was higher in the 4-month old trial. Treatments with more than 50% oat content had higher acid phosphatase activity in the 4- than 28 month old trial. Effects of cover crop, as the main factor, was significant in all enzymes (P < 0.05), with 70% oat + 30% vetch treatment having the highest dehydrogenase and arylsulphatase while for alkaline phosphatase it had similar results to 90% oat + 10% vetch. For β-glucosidase and urease, effects of cover crop as the main factor were also significant with sole vetch giving the highest activity for both enzymes. Acid phosphatase activity was highest in sole oat. Particulate OM was highest in the 100% oat treatment and declined with decrease in the proportion of oat in the biculture. The 50% oat + 50% vetch treatment had similar POM to the 70% oat +30% vetch in the 4 month old trial and to the 90% oat + 10% vetch in the 28 months old trial in the 0-5 cm depth (P < 0.05). In the 5-20 cm depth, the 70% oat +30% vetch treatment had similar POM to the 90% oat + 10% vetch in the 28 month old trial. The 70% oat+30% vetch had greatest WSC and MBC followed by the 90% oat +10% vetch, with the 50% oat + 50% vetch being similar to 100% vetch and 100% oat (MBC only). The 28 months old trial had greater POM and WSC than the 4 months trial. The findings of this study imply that the use of grazing vetch and fertilization of cover crops only improves soil biological activity, represented by MBC and enzyme activities, after 5 years of maize-cover crop rotations in low input conservation agriculture system. Bicultures, particularly the 70% oat + 30% vetch, work better than their sole crops in improving organic matter fractions, MBC and enzyme activities and that POM, WSC, MBC, enzyme activities are useful early indicators of soil organic matter build-up of CA systems.
- Full Text:
Electing high-order modes in solid state laser resonators
- Authors: Iheanetu, Kelachukwu
- Date: 2014
- Language: English
- Type: Thesis , Masters , MSc (Physics)
- Identifier: http://hdl.handle.net/10353/995 , vital:26516
- Description: The first chapter considered the fundamental processes of laser operation: photon absorption, spontaneous and stimulated emissions. These processes are considered when designing a laser gain medium. A four-level laser scheme was also illustrated. Then, the basic components and operating principle of a simple laser system was presented using a diode end-pumped Nd:YAG solid state laser resonator. The second chapter considered laser light as light rays propagating in the resonator and extensively discussed the oscillating field in the laser resonators. It examined the characteristics of the fundamental Gaussian mode and the same theory was applied to higher-order modes. Chapter three started with an introduction to beam shaping and proceeded to present a review of some intra-cavity beam shaping techniques, the use of; graded phase mirrors, difractive elements { binary phase elements and spiral phase elements. Also, a brief discussion was given on the concept of conventional holography and digital holography. The phase-only spatial light modulator (SLM) was presented, which by default is used to perform (only) phase modulation of optical fields and how it can be use to perform amplitude modulation also. Finally, a detailed discussion of the digital laser which uses the intracavity SLM as a mode selection element was presented, since it was the technique used in the experiment. The elegance of dynamic on-demand mode selection that required only a change of the grey-scale hologram on the SLM was one quality that was exploited in using the digital laser. The next two chapters presented the experiments and results. The concept of the digital laser was first used in the experiment in chapter four, to assemble a stable diode endpumped Nd:YAG solid state laser resonator. Basically, the cavity was of hemispherical configuration using an intra-cavity SLM (virtual concave mirror) as a back re ector and a at mirror output coupler. A virtual concave mirror was achieve on the SLM by using phase modulation to generate the hologram of a lens, which when displayed on the SLM made it to mimic a concave mirror. Then the next phase was using symmetric Laguerre-Gaussian mode function, of zero azimuthal order to generate digital holograms that correspond to amplitude absorbing concentric rings. These holograms, combined with the hologram that iv mimics a concave mirror were used on the SLM to perform high-order Laguerre-Gaussian modes selection in the cavity. The fifth chapter presented the results of the mode selection and considered the purity of the beam at the output coupler by comparing measured modal properties with the theoretical prediction. The outcome confirmed that the modes were of high purity and quality which further implied that the cavity was indeed selecting single pure high-order modes. The results also demonstrated that forcing the cavity to oscillate at higher-order modes (p = 3) extracted 74% more power from the gain medium compared to the fundamental mode (p = 0), but this extra power is only accessible beyond a critical pump input power of 38.8 W. Laser brightness describes the potential of a laser beam to achieve high intensities while still maintaining a large Rayleigh range. It is a property that is dependent on beam power and its quality factor. To achieve high brightness one needs to generate a beam that extracts maximum power from the gain with good beam quality. Building on the experiments demonstrated in this study, one can make the correct choices of output coupler's re ectivity, the laser gain medium's length and doping concentration and the pump mode overlap for a particular mode to further enhance energy extraction from the cavity, and then using well known extra-cavity techniques to improve the output beams quality factor by transforming the high-order mode back to the fundamental mode. This will electively achieve higher laser brightness.
- Full Text:
- Authors: Iheanetu, Kelachukwu
- Date: 2014
- Language: English
- Type: Thesis , Masters , MSc (Physics)
- Identifier: http://hdl.handle.net/10353/995 , vital:26516
- Description: The first chapter considered the fundamental processes of laser operation: photon absorption, spontaneous and stimulated emissions. These processes are considered when designing a laser gain medium. A four-level laser scheme was also illustrated. Then, the basic components and operating principle of a simple laser system was presented using a diode end-pumped Nd:YAG solid state laser resonator. The second chapter considered laser light as light rays propagating in the resonator and extensively discussed the oscillating field in the laser resonators. It examined the characteristics of the fundamental Gaussian mode and the same theory was applied to higher-order modes. Chapter three started with an introduction to beam shaping and proceeded to present a review of some intra-cavity beam shaping techniques, the use of; graded phase mirrors, difractive elements { binary phase elements and spiral phase elements. Also, a brief discussion was given on the concept of conventional holography and digital holography. The phase-only spatial light modulator (SLM) was presented, which by default is used to perform (only) phase modulation of optical fields and how it can be use to perform amplitude modulation also. Finally, a detailed discussion of the digital laser which uses the intracavity SLM as a mode selection element was presented, since it was the technique used in the experiment. The elegance of dynamic on-demand mode selection that required only a change of the grey-scale hologram on the SLM was one quality that was exploited in using the digital laser. The next two chapters presented the experiments and results. The concept of the digital laser was first used in the experiment in chapter four, to assemble a stable diode endpumped Nd:YAG solid state laser resonator. Basically, the cavity was of hemispherical configuration using an intra-cavity SLM (virtual concave mirror) as a back re ector and a at mirror output coupler. A virtual concave mirror was achieve on the SLM by using phase modulation to generate the hologram of a lens, which when displayed on the SLM made it to mimic a concave mirror. Then the next phase was using symmetric Laguerre-Gaussian mode function, of zero azimuthal order to generate digital holograms that correspond to amplitude absorbing concentric rings. These holograms, combined with the hologram that iv mimics a concave mirror were used on the SLM to perform high-order Laguerre-Gaussian modes selection in the cavity. The fifth chapter presented the results of the mode selection and considered the purity of the beam at the output coupler by comparing measured modal properties with the theoretical prediction. The outcome confirmed that the modes were of high purity and quality which further implied that the cavity was indeed selecting single pure high-order modes. The results also demonstrated that forcing the cavity to oscillate at higher-order modes (p = 3) extracted 74% more power from the gain medium compared to the fundamental mode (p = 0), but this extra power is only accessible beyond a critical pump input power of 38.8 W. Laser brightness describes the potential of a laser beam to achieve high intensities while still maintaining a large Rayleigh range. It is a property that is dependent on beam power and its quality factor. To achieve high brightness one needs to generate a beam that extracts maximum power from the gain with good beam quality. Building on the experiments demonstrated in this study, one can make the correct choices of output coupler's re ectivity, the laser gain medium's length and doping concentration and the pump mode overlap for a particular mode to further enhance energy extraction from the cavity, and then using well known extra-cavity techniques to improve the output beams quality factor by transforming the high-order mode back to the fundamental mode. This will electively achieve higher laser brightness.
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Electronic Governance (E-Governance) as a Public Sector Management Tool for service provision in Buffalo City Metropolitan Municipality
- Authors: Moyo, Thokozani P
- Date: 2014
- Language: English
- Type: Thesis , Masters , MPA
- Identifier: vital:11714 , http://hdl.handle.net/10353/d1015268
- Description: The study explores the use of Electronic governance (E-governance) as a Public Sector management tool for service provision in the Buffalo City Metropolitan Municipality. The main research question being pursued sought to find out the extent to which E-governance can be an effective tool for public sector management and service provision in the municipality. The study used both quantitative data (obtained through questionnaire survey) and qualitative data (through in-depth responses from municipality employees). The findings of the study seem to indicate that electronic governance is being utilised by a lesser percentage of citizens although it seems to be slowly gaining popularity with the highly educated and younger members of the public. Some members of the communities were still adamant to using online resources for different reasons. The study also reveals some challenges such as poverty, inequality and illiteracy as some of the hindrances to e-government. However, there is a degree of success of electronic governance in the municipality as evidenced by the percentage of the population now using the online transactions. A lot needs to be done in order to view e-governance as a true success in this municipality of Buffalo City Metropolitan if services are to be delivered effectively and efficiently to the people. It is therefore strongly recommended that there is a need to put in place good educational measures to ensure that the citizens are informed about various ways of doing online transactions with the municipality other than physically going there.
- Full Text:
- Authors: Moyo, Thokozani P
- Date: 2014
- Language: English
- Type: Thesis , Masters , MPA
- Identifier: vital:11714 , http://hdl.handle.net/10353/d1015268
- Description: The study explores the use of Electronic governance (E-governance) as a Public Sector management tool for service provision in the Buffalo City Metropolitan Municipality. The main research question being pursued sought to find out the extent to which E-governance can be an effective tool for public sector management and service provision in the municipality. The study used both quantitative data (obtained through questionnaire survey) and qualitative data (through in-depth responses from municipality employees). The findings of the study seem to indicate that electronic governance is being utilised by a lesser percentage of citizens although it seems to be slowly gaining popularity with the highly educated and younger members of the public. Some members of the communities were still adamant to using online resources for different reasons. The study also reveals some challenges such as poverty, inequality and illiteracy as some of the hindrances to e-government. However, there is a degree of success of electronic governance in the municipality as evidenced by the percentage of the population now using the online transactions. A lot needs to be done in order to view e-governance as a true success in this municipality of Buffalo City Metropolitan if services are to be delivered effectively and efficiently to the people. It is therefore strongly recommended that there is a need to put in place good educational measures to ensure that the citizens are informed about various ways of doing online transactions with the municipality other than physically going there.
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Energy and sustainable development: the case of Dewedzo rural community in Zimbabwe
- Authors: Mbulayi, Shingirai P
- Date: 2014
- Subjects: Sustainable development -- Zimbabwe , Renewable energy sources -- Zimbabwe , Power resources -- Zimbabwe , Energy consumption -- Zimbabwe
- Language: English
- Type: Thesis , Masters , M Soc Sc (Dev)
- Identifier: http://hdl.handle.net/10353/866 , vital:26504 , Sustainable development -- Zimbabwe , Renewable energy sources -- Zimbabwe , Power resources -- Zimbabwe , Energy consumption -- Zimbabwe
- Description: Energy poverty is a concept that has gained significance quite recently. Its significance has been prompted by the realization that without sustainable modern energy alternatives for the rural poor, prospects for rural transformation remains low. The recognition of modern energy as one of the missing link in rural transformation comes amid the growing concern about the negative effects of relying on traditional energy services and the increasing forecasts that most developing countries are likely to miss their MDG targets by 2015. Drawing on the Modernization and the Sustainable Development Approach, this study concluded that improving the quantity and quality of energy services consumed by the rural poor can counteract rural underdevelopment and enhance rural social and economic transformation in Dewedzo. The study confirmed that energy poor households are prone to various social, economic and environmental detriments such as poor health, hunger, malnutrition, poor education and missed socio economic opportunities. By addressing rural people‟s energy needs, more nexus can be injected into rural productivity and the economic social outputs of this process can in turn increase the pace at which MDGs can be achieved.
- Full Text:
- Authors: Mbulayi, Shingirai P
- Date: 2014
- Subjects: Sustainable development -- Zimbabwe , Renewable energy sources -- Zimbabwe , Power resources -- Zimbabwe , Energy consumption -- Zimbabwe
- Language: English
- Type: Thesis , Masters , M Soc Sc (Dev)
- Identifier: http://hdl.handle.net/10353/866 , vital:26504 , Sustainable development -- Zimbabwe , Renewable energy sources -- Zimbabwe , Power resources -- Zimbabwe , Energy consumption -- Zimbabwe
- Description: Energy poverty is a concept that has gained significance quite recently. Its significance has been prompted by the realization that without sustainable modern energy alternatives for the rural poor, prospects for rural transformation remains low. The recognition of modern energy as one of the missing link in rural transformation comes amid the growing concern about the negative effects of relying on traditional energy services and the increasing forecasts that most developing countries are likely to miss their MDG targets by 2015. Drawing on the Modernization and the Sustainable Development Approach, this study concluded that improving the quantity and quality of energy services consumed by the rural poor can counteract rural underdevelopment and enhance rural social and economic transformation in Dewedzo. The study confirmed that energy poor households are prone to various social, economic and environmental detriments such as poor health, hunger, malnutrition, poor education and missed socio economic opportunities. By addressing rural people‟s energy needs, more nexus can be injected into rural productivity and the economic social outputs of this process can in turn increase the pace at which MDGs can be achieved.
- Full Text: