Risk factors associated with developing asthma and tuberculosis: a case study of a hospital, Lagos Nigeria
- Authors: Adeniji, Tolulope Olubunmi
- Date: 2015
- Subjects: Asthma -- Nigeria -- Epidemiology , Diseases -- Risk factors -- Nigeria
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/13216 , vital:39616
- Description: The purpose of the study is to assess risk factors associated with developing asthma and tuberculosis. Methodology: A quantitative study was conducted on 133 randomly selected tuberculosis respondents, 91 of whom were suffering from TB at the time of the study. 120 respondents were also selected randomly for asthma of which 82 were asthmatic. Data were collected by using a self-structured questionnaire. The statistical analysis was done with the statistical package for social sciences (SPSS, version 18) using the descriptive statistics and logistic regression model. Results: Findings from the study show that a large percentage of the participants for both diseases were male, and the carriers of the diseases were also mostly male. Amongst the factors assessed, smoking, a weak immune system and a history of contact with tuberculosis infected persons were factors independently associated with developing tuberculosis. In the case of asthma, family history, smoking and exposure to allergen irritants were the factors independently associated with developing the disease. Conclusion: The findings highlight the need for increasing awareness through information, education and communication to address the risk factors of tuberculosis and asthma in order to decrease the rate of outspread. Recommendations: Factors triggering asthma among humans should be avoided. Since tuberculosis can be contracted through person to person contact, proper sanitation and regular medical attention are advocated for safeguarding personal and public health.
- Full Text:
- Date Issued: 2015
- Authors: Adeniji, Tolulope Olubunmi
- Date: 2015
- Subjects: Asthma -- Nigeria -- Epidemiology , Diseases -- Risk factors -- Nigeria
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/13216 , vital:39616
- Description: The purpose of the study is to assess risk factors associated with developing asthma and tuberculosis. Methodology: A quantitative study was conducted on 133 randomly selected tuberculosis respondents, 91 of whom were suffering from TB at the time of the study. 120 respondents were also selected randomly for asthma of which 82 were asthmatic. Data were collected by using a self-structured questionnaire. The statistical analysis was done with the statistical package for social sciences (SPSS, version 18) using the descriptive statistics and logistic regression model. Results: Findings from the study show that a large percentage of the participants for both diseases were male, and the carriers of the diseases were also mostly male. Amongst the factors assessed, smoking, a weak immune system and a history of contact with tuberculosis infected persons were factors independently associated with developing tuberculosis. In the case of asthma, family history, smoking and exposure to allergen irritants were the factors independently associated with developing the disease. Conclusion: The findings highlight the need for increasing awareness through information, education and communication to address the risk factors of tuberculosis and asthma in order to decrease the rate of outspread. Recommendations: Factors triggering asthma among humans should be avoided. Since tuberculosis can be contracted through person to person contact, proper sanitation and regular medical attention are advocated for safeguarding personal and public health.
- Full Text:
- Date Issued: 2015
Study of the biotransformations and microbiological properties of cymbopogon citratus
- Ajayi, Emmanuel Olusegun https://orcid.org/0000-0002-0838-4948
- Authors: Ajayi, Emmanuel Olusegun https://orcid.org/0000-0002-0838-4948
- Date: 2015
- Subjects: Lemongras , Essences and essential oils
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/19737 , vital:43197
- Description: Variations in the essential oil yield, chemical composition and kinetics of chemical transformation, antibacterial, and antioxidant properties of the Cymbopogon citratus cultivated in Alice, Eastern Cape of South Africa, over a period of 12 months using the solvent-free microwave extraction and the modified forms of conventional hydrodistillation methods have been evaluated. The modified forms involve variation in the pH medium to effect extraction and to obtain the whole leaf extracts of Cymbopogon citratus (lemongrass). The GC-MS analyses of the essential oils revealed the presence of 10, 11, 13, and 9 principal compounds in the microwave, extraction, hydrodistillation (water-distilled), hydrodistillation (aciddistilled and hydrodistillation (base-distilled), respectively with citral being the prominent compound in all the various extraction methods, with the water-distilled method having the highest cumulative citral content under the period specified. Each of the components of the oils varied in quantity and quality of yield at different points of the year. Different extraction methods produce different compounds. Increase in the amount of citral content was observed during the maturation stage of Cymbopogon citratus in all the extraction methods. Quantitative evaluation of antibacterial activity, minimum inhibitory concentration (MIC) values were determined on the oils and extracts of Cymbopogon citratus using agar dilution method. The essential oils obtained using all the methods of extraction showed activity against all the tested bacteria at a concentration of 10 mg mL-1. The minimum inhibitory concentrations for the acid-distilled varied between 1.25 and 5.0 mg mL-1, while those obtained by both water- and base-distilled showed equal activity on the microorganisms with the MIC ranging between 2.5 and 10 mg mL-1. The microwave extraction showed the least activity with the MIC of 10 mg mL-1. This however suggested that the oils obtained through acid-distillation showed the greatest activity than all other methods of extraction. Activity of the various extracts on bacteria showed that the ethanol extract had the highest activity on the tested organisms with MIC ranging between 0.625 and 1.25 mg mL-1. This was closely followed by the acid-extract (1.25 and 5.0 mg mL-1), methanol extract (1.25 and 10 mg mL-1), acetone extract (2.5 and 5.0 mg mL-1), and base extract (5.0 mg mL-1). Both cold water and hot water extracts showed the least activity of MIC, >10 mg mL-1. The antioxidant and free-radical scavenging activity of the obtained oils and extracts were tested by means of 1,1-diphenyl-2-picrylhydrazyl radical (DPPH+) assay, [(2,2ˊ-azino bis-(3-ethylbenzothiazoline-6-sulfonic acid)] (ABTS), nitric oxide and ferric reducing power assays. The oils and extracts showed DPPH radical scavenging ability, but not as high as the standard drugs. The base extract showed a higher reducing power than the standard drug, rutin. There were significant differences in the phytochemicals contents of the various leaf extracts. The acetone extract has the highest flavonol, proanthocyanidin, and alkaloid contents. The ethanol extract showed the highest amount of phenolic content with the acid extract, having the least. Thin layer chromatography (TLC) and column chromatography was employed to obtain different fractions of extracts using four eluent solvent systems of varying polarities: toluene, petroleum ether, hexane and ethyl acetate and sprayed with anisaldehyde. A single, visible spot of B-fraction was developed, collected and analyzed as 1-methyl-2,4,5- trinitroimidazole with renown valuable properties. , Thesis (PhD) -- Faculty of Science and Agriculture, 2015
- Full Text:
- Date Issued: 2015
- Authors: Ajayi, Emmanuel Olusegun https://orcid.org/0000-0002-0838-4948
- Date: 2015
- Subjects: Lemongras , Essences and essential oils
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/19737 , vital:43197
- Description: Variations in the essential oil yield, chemical composition and kinetics of chemical transformation, antibacterial, and antioxidant properties of the Cymbopogon citratus cultivated in Alice, Eastern Cape of South Africa, over a period of 12 months using the solvent-free microwave extraction and the modified forms of conventional hydrodistillation methods have been evaluated. The modified forms involve variation in the pH medium to effect extraction and to obtain the whole leaf extracts of Cymbopogon citratus (lemongrass). The GC-MS analyses of the essential oils revealed the presence of 10, 11, 13, and 9 principal compounds in the microwave, extraction, hydrodistillation (water-distilled), hydrodistillation (aciddistilled and hydrodistillation (base-distilled), respectively with citral being the prominent compound in all the various extraction methods, with the water-distilled method having the highest cumulative citral content under the period specified. Each of the components of the oils varied in quantity and quality of yield at different points of the year. Different extraction methods produce different compounds. Increase in the amount of citral content was observed during the maturation stage of Cymbopogon citratus in all the extraction methods. Quantitative evaluation of antibacterial activity, minimum inhibitory concentration (MIC) values were determined on the oils and extracts of Cymbopogon citratus using agar dilution method. The essential oils obtained using all the methods of extraction showed activity against all the tested bacteria at a concentration of 10 mg mL-1. The minimum inhibitory concentrations for the acid-distilled varied between 1.25 and 5.0 mg mL-1, while those obtained by both water- and base-distilled showed equal activity on the microorganisms with the MIC ranging between 2.5 and 10 mg mL-1. The microwave extraction showed the least activity with the MIC of 10 mg mL-1. This however suggested that the oils obtained through acid-distillation showed the greatest activity than all other methods of extraction. Activity of the various extracts on bacteria showed that the ethanol extract had the highest activity on the tested organisms with MIC ranging between 0.625 and 1.25 mg mL-1. This was closely followed by the acid-extract (1.25 and 5.0 mg mL-1), methanol extract (1.25 and 10 mg mL-1), acetone extract (2.5 and 5.0 mg mL-1), and base extract (5.0 mg mL-1). Both cold water and hot water extracts showed the least activity of MIC, >10 mg mL-1. The antioxidant and free-radical scavenging activity of the obtained oils and extracts were tested by means of 1,1-diphenyl-2-picrylhydrazyl radical (DPPH+) assay, [(2,2ˊ-azino bis-(3-ethylbenzothiazoline-6-sulfonic acid)] (ABTS), nitric oxide and ferric reducing power assays. The oils and extracts showed DPPH radical scavenging ability, but not as high as the standard drugs. The base extract showed a higher reducing power than the standard drug, rutin. There were significant differences in the phytochemicals contents of the various leaf extracts. The acetone extract has the highest flavonol, proanthocyanidin, and alkaloid contents. The ethanol extract showed the highest amount of phenolic content with the acid extract, having the least. Thin layer chromatography (TLC) and column chromatography was employed to obtain different fractions of extracts using four eluent solvent systems of varying polarities: toluene, petroleum ether, hexane and ethyl acetate and sprayed with anisaldehyde. A single, visible spot of B-fraction was developed, collected and analyzed as 1-methyl-2,4,5- trinitroimidazole with renown valuable properties. , Thesis (PhD) -- Faculty of Science and Agriculture, 2015
- Full Text:
- Date Issued: 2015
Woody encroachment and plant-root soil interactions in a semi-arid savanna
- Authors: Gusha, Bukho
- Date: 2015
- Subjects: Pastures -- Management Weeds Invasive plants
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/12139 , vital:39174
- Description: Savannas occupy 1/8 of the global land surface, support a large proportion of the world’s human population and the majority of its rangeland and livestock. Woody encroachment has been reported as the major challenge in these landscapes. This study describes the differences between three contrasting tree density classes in a semi- arid savanna with the view to developing an improved understanding of woody encroachment which is prevalent in this region. The study attempted to determine if there was a relationship between lateral root distributions at varying soil depths with increasing levels of woody encroachment, and to compare species composition and soil water profiles in these rangelands. Three homogeneous vegetation units, namely: sparsely encroached (HVU1), grassland (HVU2) and Albany thicket (HVU3) were identified for the study sites. A Trench method was used determine root biomass and a step point method was used to determine herbaceous species composition in all the HVUs. The results showed that more Decreaser species (especially Themeda triandra) were recorded in a sparsely encroached site (HVU1) and grassland site (HVU2), while Cynodon dactylon was mostly recorded in the thicket site (HVU3). Acacia karroo was mostly recorded in HVU1 while in HVU2 other woody species such as Coddia rudis and Grewia occidentalis were also recoded. HVU3 had the poorest basal cover (point to tuft distance) (22.60 cm) while HVU1 (9.93 cm) and HVU2 (7.73 cm) had moderate basal cover. The herbaceous standing biomass was significantly different across the HVUs. HVU3 was higher (1206.15 kg ha-1) than HVU1 (942.43 kg ha-1) and HVU2 (677.10 kg ha-1). The soil moisture content was significantly different between the HVUs, but was not significantly different between the depths (p< 0.05). High soil moisture content was recorded in HVU3 compared to other HVUs. The results of Analysis of Variance (ANOVA) showed that soil depth and the type of homogenous vegetation unit (HVU) had significant effects (p<0.01) on root biomass. The pair wise t-test showed that there were no significant difference in root biomass between sparsely encroached (HVU1) and grassland (HVU2) sites (p>0.05), but there were significant differences in root biomass between grassland (HVU2) and thicket (HVU3) site (p<0.05). The mean for total root biomass found in the study was 2.66 kg m-2. In all the trenches most of the root biomass was found in depth 1 (0-30 cm) which was 2.43 kg m-2followed by 1.32 kg m-2 in depth 2 (30-60 cm) and 0.49 kg m-2 in depth 3 (60-90 cm). According to the results on species composition, herbaceous biomass, basal cover, soil moisture content and the root biomass, Kwezana communal rangeland has a potential of running a sustainable livestock production enterprise if proper management practices can be implemented. To improve the rangelands of Kwezana communal rangelands, management such as proper resting, burning, proper stocking rates and physically clearing of bushes should be considered.
- Full Text:
- Date Issued: 2015
- Authors: Gusha, Bukho
- Date: 2015
- Subjects: Pastures -- Management Weeds Invasive plants
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/12139 , vital:39174
- Description: Savannas occupy 1/8 of the global land surface, support a large proportion of the world’s human population and the majority of its rangeland and livestock. Woody encroachment has been reported as the major challenge in these landscapes. This study describes the differences between three contrasting tree density classes in a semi- arid savanna with the view to developing an improved understanding of woody encroachment which is prevalent in this region. The study attempted to determine if there was a relationship between lateral root distributions at varying soil depths with increasing levels of woody encroachment, and to compare species composition and soil water profiles in these rangelands. Three homogeneous vegetation units, namely: sparsely encroached (HVU1), grassland (HVU2) and Albany thicket (HVU3) were identified for the study sites. A Trench method was used determine root biomass and a step point method was used to determine herbaceous species composition in all the HVUs. The results showed that more Decreaser species (especially Themeda triandra) were recorded in a sparsely encroached site (HVU1) and grassland site (HVU2), while Cynodon dactylon was mostly recorded in the thicket site (HVU3). Acacia karroo was mostly recorded in HVU1 while in HVU2 other woody species such as Coddia rudis and Grewia occidentalis were also recoded. HVU3 had the poorest basal cover (point to tuft distance) (22.60 cm) while HVU1 (9.93 cm) and HVU2 (7.73 cm) had moderate basal cover. The herbaceous standing biomass was significantly different across the HVUs. HVU3 was higher (1206.15 kg ha-1) than HVU1 (942.43 kg ha-1) and HVU2 (677.10 kg ha-1). The soil moisture content was significantly different between the HVUs, but was not significantly different between the depths (p< 0.05). High soil moisture content was recorded in HVU3 compared to other HVUs. The results of Analysis of Variance (ANOVA) showed that soil depth and the type of homogenous vegetation unit (HVU) had significant effects (p<0.01) on root biomass. The pair wise t-test showed that there were no significant difference in root biomass between sparsely encroached (HVU1) and grassland (HVU2) sites (p>0.05), but there were significant differences in root biomass between grassland (HVU2) and thicket (HVU3) site (p<0.05). The mean for total root biomass found in the study was 2.66 kg m-2. In all the trenches most of the root biomass was found in depth 1 (0-30 cm) which was 2.43 kg m-2followed by 1.32 kg m-2 in depth 2 (30-60 cm) and 0.49 kg m-2 in depth 3 (60-90 cm). According to the results on species composition, herbaceous biomass, basal cover, soil moisture content and the root biomass, Kwezana communal rangeland has a potential of running a sustainable livestock production enterprise if proper management practices can be implemented. To improve the rangelands of Kwezana communal rangelands, management such as proper resting, burning, proper stocking rates and physically clearing of bushes should be considered.
- Full Text:
- Date Issued: 2015
Woody encroachment and plant-root soil interactions in a semi-arid savanna
- Authors: Gusha, Bukho
- Date: 2015
- Subjects: Pastures -- Management Weeds Invasive plants
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/12053 , vital:39131
- Description: Savannas occupy 1/8 of the global land surface, support a large proportion of the world’s human population and the majority of its rangeland and livestock. Woody encroachment has been reported as the major challenge in these landscapes. This study describes the differences between three contrasting tree density classes in a semi- arid savanna with the view to developing an improved understanding of woody encroachment which is prevalent in this region. The study attempted to determine if there was a relationship between lateral root distributions at varying soil depths with increasing levels of woody encroachment, and to compare species composition and soil water profiles in these rangelands. Three homogeneous vegetation units, namely: sparsely encroached (HVU1), grassland (HVU2) and Albany thicket (HVU3) were identified for the study sites. A Trench method was used determine root biomass and a step point method was used to determine herbaceousspecies composition in all the HVUs. The results showed that more Decreaser species (especially Themeda triandra) were recorded in a sparsely encroached site (HVU1) and grassland site (HVU2), while Cynodon dactylon was mostly recorded in the thicket site (HVU3). Acacia karroo was mostly recorded in HVU1 while in HVU2 other woody species such as Coddia rudis and Grewia occidentalis were also recoded. HVU3 had the poorest basal cover (point to tuft distance) (22.60 cm) while HVU1 (9.93 cm) and HVU2 (7.73 cm) had moderate basal cover. The herbaceous standing biomass was significantly different across the HVUs. HVU3 was higher (1206.15 kg ha-1) than HVU1 (942.43 kg ha-1) and HVU2 (677.10 kg ha-1). The soil moisture content was significantly different between the HVUs, but was not significantly different between the depths (p< 0.05). High soil moisture content was recorded in HVU3 compared to other HVUs. The results of Analysis of Variance (ANOVA) showed that soil depth and the type of homogenous vegetation unit (HVU) had significant effects (p<0.01) on root biomass. The pair wise t-test showed that there were no significant difference in root biomass between sparsely encroached (HVU1) and grassland (HVU2) sites (p>0.05), but there were significant differences in root biomass between grassland (HVU2) and thicket (HVU3) site (p<0.05). The mean for total root biomass found in the study was 2.66 kg m-2. In all the trenches most of the root biomass was found in depth 1 (0-30 cm) which was 2.43 kg m-2followed by 1.32 kg m-2 in depth 2 (30-60 cm) and 0.49 kg m-2 in depth 3 (60-90 cm). According to the results on species composition, herbaceous biomass, basal cover, soil moisture content and the root biomass, Kwezana communal rangeland has a potential of running a sustainable livestock production enterprise if proper management practices can be implemented. To improve the rangelands of Kwezana communal rangelands management such as proper resting, burning, proper stocking rates and physically clearing of bushes should be considered.
- Full Text:
- Date Issued: 2015
- Authors: Gusha, Bukho
- Date: 2015
- Subjects: Pastures -- Management Weeds Invasive plants
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/12053 , vital:39131
- Description: Savannas occupy 1/8 of the global land surface, support a large proportion of the world’s human population and the majority of its rangeland and livestock. Woody encroachment has been reported as the major challenge in these landscapes. This study describes the differences between three contrasting tree density classes in a semi- arid savanna with the view to developing an improved understanding of woody encroachment which is prevalent in this region. The study attempted to determine if there was a relationship between lateral root distributions at varying soil depths with increasing levels of woody encroachment, and to compare species composition and soil water profiles in these rangelands. Three homogeneous vegetation units, namely: sparsely encroached (HVU1), grassland (HVU2) and Albany thicket (HVU3) were identified for the study sites. A Trench method was used determine root biomass and a step point method was used to determine herbaceousspecies composition in all the HVUs. The results showed that more Decreaser species (especially Themeda triandra) were recorded in a sparsely encroached site (HVU1) and grassland site (HVU2), while Cynodon dactylon was mostly recorded in the thicket site (HVU3). Acacia karroo was mostly recorded in HVU1 while in HVU2 other woody species such as Coddia rudis and Grewia occidentalis were also recoded. HVU3 had the poorest basal cover (point to tuft distance) (22.60 cm) while HVU1 (9.93 cm) and HVU2 (7.73 cm) had moderate basal cover. The herbaceous standing biomass was significantly different across the HVUs. HVU3 was higher (1206.15 kg ha-1) than HVU1 (942.43 kg ha-1) and HVU2 (677.10 kg ha-1). The soil moisture content was significantly different between the HVUs, but was not significantly different between the depths (p< 0.05). High soil moisture content was recorded in HVU3 compared to other HVUs. The results of Analysis of Variance (ANOVA) showed that soil depth and the type of homogenous vegetation unit (HVU) had significant effects (p<0.01) on root biomass. The pair wise t-test showed that there were no significant difference in root biomass between sparsely encroached (HVU1) and grassland (HVU2) sites (p>0.05), but there were significant differences in root biomass between grassland (HVU2) and thicket (HVU3) site (p<0.05). The mean for total root biomass found in the study was 2.66 kg m-2. In all the trenches most of the root biomass was found in depth 1 (0-30 cm) which was 2.43 kg m-2followed by 1.32 kg m-2 in depth 2 (30-60 cm) and 0.49 kg m-2 in depth 3 (60-90 cm). According to the results on species composition, herbaceous biomass, basal cover, soil moisture content and the root biomass, Kwezana communal rangeland has a potential of running a sustainable livestock production enterprise if proper management practices can be implemented. To improve the rangelands of Kwezana communal rangelands management such as proper resting, burning, proper stocking rates and physically clearing of bushes should be considered.
- Full Text:
- Date Issued: 2015
Using GIS and remote sensing to map suitable sites for wind farms: a case study of Nkonkobe Municipality, Eastern Cape.
- Authors: Gwena, Jay
- Date: 2015
- Subjects: Geographic information systems http://id.loc.gov/authorities/subjects/sh90001880 , Remote sensing http://id.loc.gov/authorities/subjects/sh85112798 , Renewable energy sources http://id.loc.gov/authorities/subjects/sh85112837
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/19420 , vital:43082
- Description: Issues relating to energy use, renewable energy introduction and climate change have received a lot of attention from governments throughout the world in the past two decades. Many developing nations like South Africa heavily rely on coal and other non-renewable resources for their production of energy. The processing of the non-renewable resources into secondary energy forms is according to many energy experts a chief contributor to climate change. Climate change is affecting agricultural production in many developing countries that entirely rely on rainfall for their production. The loss in production in South Africa is increasing the level of poverty in low-income earners and unemployed people. Also a lot of households found in rural areas of South Africa have no access to electricity. Electricity in South Africa is generated and distributed by Eskom a state owned company. In April 2008 Eskom failed to meet power demand and started introducing load shedding to maintain and upgrade their power plants. The load shedding stopped for while and was introduced again in 2014 when the power utility faced the challenge of failing to produce power to meet demand again due to problems with their power stations. The ongoing energy provision problems in South Africa can be alleviated by introducing alternative sources like renewable energy. Introduction of renewable energy in poorly developed areas like Nkonkobe Municipality can help households‘ access electricity and reduce load on the national grid. The aim of this study was to locate suitable sites for setting up wind farms in Nkonkobe municipality in South Africa. Wind energy as a resource is abundant in many areas of South Africa and areas to set wind farms for optimum harness of wind power were identified using GIS, remote sensing and multi-criteria decision making techniques. Wind speed, distance from settlements, distance from main roads, distance from national, slope and land use/land cover were chosen as the factors to consider in selecting a suitable site. Data was collected from South Africa Weather Services, University of Fort Hare and online free data sources. Thematic maps for all the factors were developed in ArcGIS and fed into Nkonkobe Municipality database developed for the study. Thematic maps were assigned weights before being overlaid using weighted overlay tool. Weights for the factors were determined using Analytical hierarchy Process‘ pairwise comparison approach. Weighted overlay of the thematic maps produced a map showing suitable areas based on the weight influence of each factor. The output map was compared to results obtained from using Boolean approach and weighted sum method as a way of checking the accuracy of obtained suitable sites. Results showed there are three sites that can be used for setting up wind farms in the study area. , Thesis (MSc) (Applied Remote Sensing and GIS) -- University of Fort Hare, 2015
- Full Text:
- Date Issued: 2015
- Authors: Gwena, Jay
- Date: 2015
- Subjects: Geographic information systems http://id.loc.gov/authorities/subjects/sh90001880 , Remote sensing http://id.loc.gov/authorities/subjects/sh85112798 , Renewable energy sources http://id.loc.gov/authorities/subjects/sh85112837
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/19420 , vital:43082
- Description: Issues relating to energy use, renewable energy introduction and climate change have received a lot of attention from governments throughout the world in the past two decades. Many developing nations like South Africa heavily rely on coal and other non-renewable resources for their production of energy. The processing of the non-renewable resources into secondary energy forms is according to many energy experts a chief contributor to climate change. Climate change is affecting agricultural production in many developing countries that entirely rely on rainfall for their production. The loss in production in South Africa is increasing the level of poverty in low-income earners and unemployed people. Also a lot of households found in rural areas of South Africa have no access to electricity. Electricity in South Africa is generated and distributed by Eskom a state owned company. In April 2008 Eskom failed to meet power demand and started introducing load shedding to maintain and upgrade their power plants. The load shedding stopped for while and was introduced again in 2014 when the power utility faced the challenge of failing to produce power to meet demand again due to problems with their power stations. The ongoing energy provision problems in South Africa can be alleviated by introducing alternative sources like renewable energy. Introduction of renewable energy in poorly developed areas like Nkonkobe Municipality can help households‘ access electricity and reduce load on the national grid. The aim of this study was to locate suitable sites for setting up wind farms in Nkonkobe municipality in South Africa. Wind energy as a resource is abundant in many areas of South Africa and areas to set wind farms for optimum harness of wind power were identified using GIS, remote sensing and multi-criteria decision making techniques. Wind speed, distance from settlements, distance from main roads, distance from national, slope and land use/land cover were chosen as the factors to consider in selecting a suitable site. Data was collected from South Africa Weather Services, University of Fort Hare and online free data sources. Thematic maps for all the factors were developed in ArcGIS and fed into Nkonkobe Municipality database developed for the study. Thematic maps were assigned weights before being overlaid using weighted overlay tool. Weights for the factors were determined using Analytical hierarchy Process‘ pairwise comparison approach. Weighted overlay of the thematic maps produced a map showing suitable areas based on the weight influence of each factor. The output map was compared to results obtained from using Boolean approach and weighted sum method as a way of checking the accuracy of obtained suitable sites. Results showed there are three sites that can be used for setting up wind farms in the study area. , Thesis (MSc) (Applied Remote Sensing and GIS) -- University of Fort Hare, 2015
- Full Text:
- Date Issued: 2015
Phytochemical, antibacterial and pharmacological investigations of Clausena Anisata (Wild). Hook : bone of the medicinal plants used for traditional treatment of "tuberculosis" in Eastern Cape, South Africa
- Authors: Lawal, Ibraheem O
- Date: 2015
- Subjects: Traditional medicine--South Africa--Eastern Cape Tuberculosis--Treatment--South Africa--Eastern Cape Mycobacterial diseases--South Africa--Eastern Cape
- Language: English
- Type: Thesis , Doctoral , Ethnobotany
- Identifier: http://hdl.handle.net/10353/11828 , vital:39110
- Description: Clausena anisata (Willd) Hook, is the only species out of the 15 species of the genus found in the African continent and is regarded as a threatened species in this area of Southern region of Africa. Its distribution spread across Africa to south-east Asia. C. anisata has a wide range of ethno-pharmacological importance. Despite the numerous studies on the pharmacological profile of the plant, there is still dearth of scientific literature on the foliar micro-morphology of this valuable medicinal plant. The morphorlogical structure of the leaves of C. anisata was examined under Light Microscopy (LM), Scanning Electron Microscopy (SEM) and Energy Dispersive x-ray Spectroscopy (EDS) following standard procedures. LM indicates the types of stomata of the leaves (amphistomatic). SEM revealed the presence of the whip like trichomes with its uniqueness to the plants. EDS showed the chemical composition of the foliar appendages which indicated the presence Ca, Mg, S, and Fe. The indication of the elements could probably be helpful in the herbal drug regulation based on the mineral composition and in return reduced herbal drug toxicity.
- Full Text:
- Date Issued: 2015
- Authors: Lawal, Ibraheem O
- Date: 2015
- Subjects: Traditional medicine--South Africa--Eastern Cape Tuberculosis--Treatment--South Africa--Eastern Cape Mycobacterial diseases--South Africa--Eastern Cape
- Language: English
- Type: Thesis , Doctoral , Ethnobotany
- Identifier: http://hdl.handle.net/10353/11828 , vital:39110
- Description: Clausena anisata (Willd) Hook, is the only species out of the 15 species of the genus found in the African continent and is regarded as a threatened species in this area of Southern region of Africa. Its distribution spread across Africa to south-east Asia. C. anisata has a wide range of ethno-pharmacological importance. Despite the numerous studies on the pharmacological profile of the plant, there is still dearth of scientific literature on the foliar micro-morphology of this valuable medicinal plant. The morphorlogical structure of the leaves of C. anisata was examined under Light Microscopy (LM), Scanning Electron Microscopy (SEM) and Energy Dispersive x-ray Spectroscopy (EDS) following standard procedures. LM indicates the types of stomata of the leaves (amphistomatic). SEM revealed the presence of the whip like trichomes with its uniqueness to the plants. EDS showed the chemical composition of the foliar appendages which indicated the presence Ca, Mg, S, and Fe. The indication of the elements could probably be helpful in the herbal drug regulation based on the mineral composition and in return reduced herbal drug toxicity.
- Full Text:
- Date Issued: 2015
Bush encroachment in the semi-arid communal grazing lands of Eastern Cape and farmer's perception of causes and livelihood impacts
- Authors: Libala, Notiswa
- Date: 2015
- Subjects: Communal rangelands--South Africa--Eastern Cape Grazing--South Africa--Eastern Cape egetation management--South Africa--Eastern Cape
- Language: English
- Type: Thesis , Masters , Pasture Science
- Identifier: http://hdl.handle.net/10353/11817 , vital:39109
- Description: The study was conducted in two communal rangelands of the Eastern Cape Province (Thorn and Mixed bush veld). The objective of the study was to investigate 1) the historical trends of bush encroachment, causes and impacts based on indigenous knowledge and perceptions of the communal people in two savannah vegetation types and 2) to determine the density and cover of woody species in the grazing areas. In each veld type, two villages were selected purposefully. A total of 120 households who own livestock were randomly selected from the four communal areas and a total of 48 elders were selected to provide information on bush encroachment and rangeland condition. For woody density and cover, grazing areas surrounding two homesteads (settlements) were selected from each communal rangeland, Two long transects radiating in the opposite direction from each homestead were established. The woody vegetation survey was conducted at 100, 200, 300, 400, 500, 600, 700, 800 and 900m distance from each homestead. In each distance, 3 (10 m x 10 m) quadrates were laid to record individual woody plant species, the height, basal stem and canopy diameters. Woody species were classified into seedlings (>0 - 1 m), saplings (>1 - 1.5 m), young shrubs (>1.5 - 2.0 m), mature shrubs (>2 - 3.0 m) and mature trees (>3.0 m). The average household size in of goat was higher than that of other livestock species. A total of 40 woody plant species were identified in all study areas. Acacia karoo, Coddia rudis and Scutia myrtina were the most dominant woody species in all study areas. Most of the woody plant species had the highest abundance in the height class >0 - 1 m. The average total woody plant density in Thorn bush and Mixed bush were 3461 and 2416 number ha-1, respectively. In conclusion both study areas were highly encroached and it was also perceived by elder from both areas that bush encroachment is a problem in the rangelands.
- Full Text:
- Date Issued: 2015
- Authors: Libala, Notiswa
- Date: 2015
- Subjects: Communal rangelands--South Africa--Eastern Cape Grazing--South Africa--Eastern Cape egetation management--South Africa--Eastern Cape
- Language: English
- Type: Thesis , Masters , Pasture Science
- Identifier: http://hdl.handle.net/10353/11817 , vital:39109
- Description: The study was conducted in two communal rangelands of the Eastern Cape Province (Thorn and Mixed bush veld). The objective of the study was to investigate 1) the historical trends of bush encroachment, causes and impacts based on indigenous knowledge and perceptions of the communal people in two savannah vegetation types and 2) to determine the density and cover of woody species in the grazing areas. In each veld type, two villages were selected purposefully. A total of 120 households who own livestock were randomly selected from the four communal areas and a total of 48 elders were selected to provide information on bush encroachment and rangeland condition. For woody density and cover, grazing areas surrounding two homesteads (settlements) were selected from each communal rangeland, Two long transects radiating in the opposite direction from each homestead were established. The woody vegetation survey was conducted at 100, 200, 300, 400, 500, 600, 700, 800 and 900m distance from each homestead. In each distance, 3 (10 m x 10 m) quadrates were laid to record individual woody plant species, the height, basal stem and canopy diameters. Woody species were classified into seedlings (>0 - 1 m), saplings (>1 - 1.5 m), young shrubs (>1.5 - 2.0 m), mature shrubs (>2 - 3.0 m) and mature trees (>3.0 m). The average household size in of goat was higher than that of other livestock species. A total of 40 woody plant species were identified in all study areas. Acacia karoo, Coddia rudis and Scutia myrtina were the most dominant woody species in all study areas. Most of the woody plant species had the highest abundance in the height class >0 - 1 m. The average total woody plant density in Thorn bush and Mixed bush were 3461 and 2416 number ha-1, respectively. In conclusion both study areas were highly encroached and it was also perceived by elder from both areas that bush encroachment is a problem in the rangelands.
- Full Text:
- Date Issued: 2015
An exploration of perceptions, adaptive capacity and food security in the Ngqushwa local municipality, Eastern Cape, South Africa
- Authors: Mazinyo, Sonwabo Perez
- Date: 2015
- Subjects: Food security -- South Africa -- Eastern Cape Climatic changes -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/19043 , vital:40107
- Description: Approximately sixty percent of Africans depend on rainfed agriculture for their livelihoods. South Africa is evidenced to be susceptible to inclement climate which impacts on rural livelihoods as well as on farming systems. While South Africa is considered to be food sufficient, it is estimated that approximately 35percent of the population is vulnerable to food insecurity. Therefore with the application of surveys and interviews this study investigates the factors influencing household, subsistence and small-scale farmer perceptions of vulnerability to climate variability as well as the determinants of adaptive capacity. A sample of 308 households is surveyed and four focus group discussions are administered in Ngqushwa Local Municipality as a case study. Furthermore, the study also focuses on the biophysical changes or factors (scientific analysis of the prevailing climatic regimes–rainfall trends); the interrogation of the impact of food systems on both food prices as well as its implications on food sovereignty. The study also interrogates the relationship between crop yield and rainfall data over a 30-year period. Therefore the study adopts a mixed method approach to ensure triangulation. The study finds that rural communities are able to perceive climate variability and its related changes as well as its negative impact on crop production, food access and availability. The perceived rainfall trends also corroborate this Pearson product-moment correlation coefficient reveals that there is a strong correlation between crop yields and rainfall (r = 0.69). Meteorological analyses also show that the rainfall trend has been significantly variable over 112 years (1900 - 2011) with several dry spells threatening the subsistence and small-scale farmers’ sustainable livelihoods. The food systems pose threats to food safety, food security and historical food sovereignty for the rural community of Ngqushwa Local Municipality. Adaptive capacity is greatly impaired by the lack of co-ordination of adaptation strategies, which communally benefit the majority of the farming respondents in the study area. Therefore vulnerability to climate variability impacts on the ability of the respondents to achieve food security. The study also finds that there is perceived competition between the farmers and wild life for the natural resources. The respondents’ perception is that climate variability and change is responsible for such competition. The study recommends that the national, provincial and local governments must foster a new food production model that is not based on the agro-business model and its attendant technologies but on one that is based on robust agro-ecological farming techniques which enhance adaptive capacity; which foster food safety; which promote food sovereignty; and which reduce vulnerability in a sustainable manner. Given the extent of climate variability in the study area the restoration of the NLM weather station infrastructure can also aid the farmers in taking advantage of a robust early warning system for better estimation of climate trends which enhance crop production.
- Full Text:
- Date Issued: 2015
- Authors: Mazinyo, Sonwabo Perez
- Date: 2015
- Subjects: Food security -- South Africa -- Eastern Cape Climatic changes -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/19043 , vital:40107
- Description: Approximately sixty percent of Africans depend on rainfed agriculture for their livelihoods. South Africa is evidenced to be susceptible to inclement climate which impacts on rural livelihoods as well as on farming systems. While South Africa is considered to be food sufficient, it is estimated that approximately 35percent of the population is vulnerable to food insecurity. Therefore with the application of surveys and interviews this study investigates the factors influencing household, subsistence and small-scale farmer perceptions of vulnerability to climate variability as well as the determinants of adaptive capacity. A sample of 308 households is surveyed and four focus group discussions are administered in Ngqushwa Local Municipality as a case study. Furthermore, the study also focuses on the biophysical changes or factors (scientific analysis of the prevailing climatic regimes–rainfall trends); the interrogation of the impact of food systems on both food prices as well as its implications on food sovereignty. The study also interrogates the relationship between crop yield and rainfall data over a 30-year period. Therefore the study adopts a mixed method approach to ensure triangulation. The study finds that rural communities are able to perceive climate variability and its related changes as well as its negative impact on crop production, food access and availability. The perceived rainfall trends also corroborate this Pearson product-moment correlation coefficient reveals that there is a strong correlation between crop yields and rainfall (r = 0.69). Meteorological analyses also show that the rainfall trend has been significantly variable over 112 years (1900 - 2011) with several dry spells threatening the subsistence and small-scale farmers’ sustainable livelihoods. The food systems pose threats to food safety, food security and historical food sovereignty for the rural community of Ngqushwa Local Municipality. Adaptive capacity is greatly impaired by the lack of co-ordination of adaptation strategies, which communally benefit the majority of the farming respondents in the study area. Therefore vulnerability to climate variability impacts on the ability of the respondents to achieve food security. The study also finds that there is perceived competition between the farmers and wild life for the natural resources. The respondents’ perception is that climate variability and change is responsible for such competition. The study recommends that the national, provincial and local governments must foster a new food production model that is not based on the agro-business model and its attendant technologies but on one that is based on robust agro-ecological farming techniques which enhance adaptive capacity; which foster food safety; which promote food sovereignty; and which reduce vulnerability in a sustainable manner. Given the extent of climate variability in the study area the restoration of the NLM weather station infrastructure can also aid the farmers in taking advantage of a robust early warning system for better estimation of climate trends which enhance crop production.
- Full Text:
- Date Issued: 2015
An exploration of perceptions, adaptive capacity and food security in the Ngqushwa local municipality, Eastern Cape, South Africa
- Mazinyo, Sonwabo Perez, Zhou, Leocadia
- Authors: Mazinyo, Sonwabo Perez , Zhou, Leocadia
- Date: 2015
- Subjects: Food security -- South Africa -- Eastern Cape Climatic changes -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/19032 , vital:40106
- Description: Approximately sixty percent of Africans depend on rainfed agriculture for their livelihoods. South Africa is evidenced to be susceptible to inclement climate which impacts on rural livelihoods as well as on farming systems. While South Africa is considered to be food sufficient, it is estimated that approximately 35% of the population is vulnerable to food insecurity. Therefore with the application of surveys and interviews this study investigates the factors influencing household, subsistence and small-scale farmer perceptions of vulnerability to climate variability as well as the determinants of adaptive capacity. A sample of 308 households is surveyed and four focus group discussions are administered in Ngqushwa Local Municipality as a case study. Furthermore, the study also focuses on the biophysical changes or factors (scientific analysis of the prevailing climatic regimes–rainfall trends); the interrogation of the impact of food systems on both food prices as well as its implications on food sovereignty. The study also interrogates the relationship between crop yield and rainfall data over a 30-year period. Therefore the study adopts a mixed method approach to ensure triangulation. The study finds that rural communities are able to perceive climate variability and its related changes as well as its negative impact on crop production, food access and availability. The perceived rainfall trends also corroborate this Pearson product-moment correlation coefficient reveals that there is a strong correlation between crop yields and rainfall (r = 0.69). Meteorological analyses also show that the rainfall trend has been significantly variable over 112 years (1900 - 2011) with several dry spells threatening the subsistence and small-scale farmers’ sustainable livelihoods. The food systems pose threats to food safety, food security and historical food sovereignty for the rural community of Ngqushwa Local Municipality. Adaptive capacity is greatly impaired by the lack of co-ordination of adaptation strategies, which communally benefit the majority of the farming respondents in the study area. Therefore vulnerability to climate variability impacts on the ability of the respondents to achieve food security. The study also finds that there is perceived competition between the farmers and wild life for the natural resources. The respondents’ perception is that climate variability and change is responsible for such competition. The study recommends that the national, provincial and local governments must foster a new food production model that is not based on the agro-business model and its attendant technologies but on one that is based on robust agro-ecological farming techniques which enhance adaptive capacity; which foster food safety; which promote food sovereignty; and which reduce vulnerability in a sustainable manner. Given the extent of climate variability in the study area the restoration of the NLM weather station infrastructure can also aid the farmers in taking advantage of a robust early warning system for better estimation of climate trends which enhance crop production.
- Full Text:
- Date Issued: 2015
- Authors: Mazinyo, Sonwabo Perez , Zhou, Leocadia
- Date: 2015
- Subjects: Food security -- South Africa -- Eastern Cape Climatic changes -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/19032 , vital:40106
- Description: Approximately sixty percent of Africans depend on rainfed agriculture for their livelihoods. South Africa is evidenced to be susceptible to inclement climate which impacts on rural livelihoods as well as on farming systems. While South Africa is considered to be food sufficient, it is estimated that approximately 35% of the population is vulnerable to food insecurity. Therefore with the application of surveys and interviews this study investigates the factors influencing household, subsistence and small-scale farmer perceptions of vulnerability to climate variability as well as the determinants of adaptive capacity. A sample of 308 households is surveyed and four focus group discussions are administered in Ngqushwa Local Municipality as a case study. Furthermore, the study also focuses on the biophysical changes or factors (scientific analysis of the prevailing climatic regimes–rainfall trends); the interrogation of the impact of food systems on both food prices as well as its implications on food sovereignty. The study also interrogates the relationship between crop yield and rainfall data over a 30-year period. Therefore the study adopts a mixed method approach to ensure triangulation. The study finds that rural communities are able to perceive climate variability and its related changes as well as its negative impact on crop production, food access and availability. The perceived rainfall trends also corroborate this Pearson product-moment correlation coefficient reveals that there is a strong correlation between crop yields and rainfall (r = 0.69). Meteorological analyses also show that the rainfall trend has been significantly variable over 112 years (1900 - 2011) with several dry spells threatening the subsistence and small-scale farmers’ sustainable livelihoods. The food systems pose threats to food safety, food security and historical food sovereignty for the rural community of Ngqushwa Local Municipality. Adaptive capacity is greatly impaired by the lack of co-ordination of adaptation strategies, which communally benefit the majority of the farming respondents in the study area. Therefore vulnerability to climate variability impacts on the ability of the respondents to achieve food security. The study also finds that there is perceived competition between the farmers and wild life for the natural resources. The respondents’ perception is that climate variability and change is responsible for such competition. The study recommends that the national, provincial and local governments must foster a new food production model that is not based on the agro-business model and its attendant technologies but on one that is based on robust agro-ecological farming techniques which enhance adaptive capacity; which foster food safety; which promote food sovereignty; and which reduce vulnerability in a sustainable manner. Given the extent of climate variability in the study area the restoration of the NLM weather station infrastructure can also aid the farmers in taking advantage of a robust early warning system for better estimation of climate trends which enhance crop production.
- Full Text:
- Date Issued: 2015
Evaluation of knowledge and practices of nurses with regard to prevention of nosocomial infection in the intensive care units of Eastern Cape Province
- Mlenzana, Nosiphiwo Priscilla
- Authors: Mlenzana, Nosiphiwo Priscilla
- Date: 2015
- Subjects: Nosocomial infections http://id.loc.gov/authorities/subjects/sh85092770 , Cross infection--Prevention http://id.loc.gov/authorities/subjects/sh2009122612 , Infection http://id.loc.gov/authorities/subjects/sh85066076
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/19639 , vital:43154
- Description: Aim: To determine the level of knowledge and practice of the nurses in the prevention and control of nosocomial infection in the intensive care units and make recommendations aiming at bridging the gap identified. In this study, the level of knowledge and practice of nurses in the intensive care units was described and its relationship with the demographic characteristics was examined utilising a quantitative approach. A quantitative descriptive design was used to examine and describe knowledge and practices of intensive care nurses with regards to prevention and control of nosocomial infection. One hundred and thirty (130) nurses participated in the study taken from the intensive care units of the five (5) state hospitals of the Eastern Cape Province. A self-designed questionnaire with close-ended questions was utilised comprising of dichotomous questions, with ‘yes’ or ‘no’ measuring knowledge nurses have and a Likert scale that measured knowledge with regards to clinical practice utilised in the prevention and control of nosocomial infections. The following ethical considerations were addressed by the study: ethical clearance, permission to conduct the study, informed consent from participants, anonymity and confidentiality and respect of individual autonomy. Findings: The respondents showed encouraging agreement with the different practices that should be followed in order to prevent spreading of nosocomial infections in their units. This knowledge suggests that the problem of infection control in ICUs may be related to the individual characteristics of the profession as opposed to being institutional. Limitations: Not all the intensive care units of the Eastern Cape hospitals were included due to challenges of time, finance and geographic factors. Recommendations: The following recommendations were made: Orientation programme to all new staff coming into the ICUs including infection control policies and guidelines; Involvement of the ICU staff in the development of infection control policies so as to ensure ownership and ultimate compliance; The employer must ensure that all resources for infection control and prevention are available and accessible to the health care workers at all times to ensure compliance. , Thesis (MCur) -- University of Fort Hare, 2015
- Full Text:
- Date Issued: 2015
- Authors: Mlenzana, Nosiphiwo Priscilla
- Date: 2015
- Subjects: Nosocomial infections http://id.loc.gov/authorities/subjects/sh85092770 , Cross infection--Prevention http://id.loc.gov/authorities/subjects/sh2009122612 , Infection http://id.loc.gov/authorities/subjects/sh85066076
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/19639 , vital:43154
- Description: Aim: To determine the level of knowledge and practice of the nurses in the prevention and control of nosocomial infection in the intensive care units and make recommendations aiming at bridging the gap identified. In this study, the level of knowledge and practice of nurses in the intensive care units was described and its relationship with the demographic characteristics was examined utilising a quantitative approach. A quantitative descriptive design was used to examine and describe knowledge and practices of intensive care nurses with regards to prevention and control of nosocomial infection. One hundred and thirty (130) nurses participated in the study taken from the intensive care units of the five (5) state hospitals of the Eastern Cape Province. A self-designed questionnaire with close-ended questions was utilised comprising of dichotomous questions, with ‘yes’ or ‘no’ measuring knowledge nurses have and a Likert scale that measured knowledge with regards to clinical practice utilised in the prevention and control of nosocomial infections. The following ethical considerations were addressed by the study: ethical clearance, permission to conduct the study, informed consent from participants, anonymity and confidentiality and respect of individual autonomy. Findings: The respondents showed encouraging agreement with the different practices that should be followed in order to prevent spreading of nosocomial infections in their units. This knowledge suggests that the problem of infection control in ICUs may be related to the individual characteristics of the profession as opposed to being institutional. Limitations: Not all the intensive care units of the Eastern Cape hospitals were included due to challenges of time, finance and geographic factors. Recommendations: The following recommendations were made: Orientation programme to all new staff coming into the ICUs including infection control policies and guidelines; Involvement of the ICU staff in the development of infection control policies so as to ensure ownership and ultimate compliance; The employer must ensure that all resources for infection control and prevention are available and accessible to the health care workers at all times to ensure compliance. , Thesis (MCur) -- University of Fort Hare, 2015
- Full Text:
- Date Issued: 2015
Primiparous and multiparous cow behaviour of friesland, jersey and cross-bred cows around calving time and during milking
- Authors: Mpisana, Zuko
- Date: 2015
- Subjects: Dairy products--Analysis Jersey cattle Milk yield
- Language: English
- Type: Thesis , Masters , Animal Science
- Identifier: http://hdl.handle.net/10353/16113 , vital:40665
- Description: The objective of the study was to determine effect of behaviour of primiparous and multiparous Friesland, Jersey and Cross-bred cows around calving time and during milking of first lactating cows in a pasture-based dairy system. The trial was conducted at the Fort Hare dairy farm. All pregnant primiparous and multiparous were kept in a maternity paddock. Five observers monitored the cows from the onset of parturition until the calf was fully expelled using digital stop watches. The behavioural responses of the cows during parturition (frequency and duration of lying, standing and walking bouts; calf licking; suckling) and milking (avoidance distance scores (ADS), entrance score, (ES), exit speed (ES), feeding score (FS), and the occurrence of stepping (STP) and kicking (KCK)) were determined on eighty consecutive days. The behavioural attributes were analysed using generalised linear model of procedure of SAS (2003). One hundred and twenty pregnant cows were used in the study, comprising of forty cows per genotype in different parities (A-primiparous, B- 2 to 4, C-5 to 6 and D-7 to 8) and kept in a maternity paddock. Five observers monitored cows from the onset of parturition until the calf was fully expelled. There were differences (P < 0.05) observed on the behavioural patterns around the time of calving. Jersey multiparous cows spent (P < 0.05) significantly most of their time (20.50±3.10) in lying position as compared to the other genotypes. The Jersey genotype also spent most (P < 0.05) of their time (48.00±0.34) in a standing position during calving period. Friesland cows spent (P < 0.05) most of their time (12.00±1.19) exhibiting either stepping or walking attributes as compared to Jersey and Crossbred cows. The Jersey genotype spent significantly (P < 0.05) more time (123.00±10.43) expelling calves compared to the other genotypes. Crossbred cows had the highest avoidance distance (14percent) scores compared to other genotypes and the Friesland cows had the lowest distance scores. The occurrence of kicking was significantly (P < 0.05) higher for the Friesland cows (57.3percent) compared to Jersey (23.2percent) and Crossbred cows (19.6percent). The Friesland cows had the highest (P < 0.05) frequency (36.2percent) feeding score compared to Jersey and Crossbred cows. The Jersey cows had the highest (60.2percent) exit speed compared to other genotypes. The occurrence of stepping was higher for the Friesland cows (53.9percent). The Friesland cows had the highest (P < 0.05) daily milk yield compared to Jersey and Crossbred cows. The present study revealed that behavioural activities of dairy cattle during parturition differed according to genotype and parity and the behavioural response of first lactating cows differ according to genotype during milking.
- Full Text:
- Date Issued: 2015
- Authors: Mpisana, Zuko
- Date: 2015
- Subjects: Dairy products--Analysis Jersey cattle Milk yield
- Language: English
- Type: Thesis , Masters , Animal Science
- Identifier: http://hdl.handle.net/10353/16113 , vital:40665
- Description: The objective of the study was to determine effect of behaviour of primiparous and multiparous Friesland, Jersey and Cross-bred cows around calving time and during milking of first lactating cows in a pasture-based dairy system. The trial was conducted at the Fort Hare dairy farm. All pregnant primiparous and multiparous were kept in a maternity paddock. Five observers monitored the cows from the onset of parturition until the calf was fully expelled using digital stop watches. The behavioural responses of the cows during parturition (frequency and duration of lying, standing and walking bouts; calf licking; suckling) and milking (avoidance distance scores (ADS), entrance score, (ES), exit speed (ES), feeding score (FS), and the occurrence of stepping (STP) and kicking (KCK)) were determined on eighty consecutive days. The behavioural attributes were analysed using generalised linear model of procedure of SAS (2003). One hundred and twenty pregnant cows were used in the study, comprising of forty cows per genotype in different parities (A-primiparous, B- 2 to 4, C-5 to 6 and D-7 to 8) and kept in a maternity paddock. Five observers monitored cows from the onset of parturition until the calf was fully expelled. There were differences (P < 0.05) observed on the behavioural patterns around the time of calving. Jersey multiparous cows spent (P < 0.05) significantly most of their time (20.50±3.10) in lying position as compared to the other genotypes. The Jersey genotype also spent most (P < 0.05) of their time (48.00±0.34) in a standing position during calving period. Friesland cows spent (P < 0.05) most of their time (12.00±1.19) exhibiting either stepping or walking attributes as compared to Jersey and Crossbred cows. The Jersey genotype spent significantly (P < 0.05) more time (123.00±10.43) expelling calves compared to the other genotypes. Crossbred cows had the highest avoidance distance (14percent) scores compared to other genotypes and the Friesland cows had the lowest distance scores. The occurrence of kicking was significantly (P < 0.05) higher for the Friesland cows (57.3percent) compared to Jersey (23.2percent) and Crossbred cows (19.6percent). The Friesland cows had the highest (P < 0.05) frequency (36.2percent) feeding score compared to Jersey and Crossbred cows. The Jersey cows had the highest (60.2percent) exit speed compared to other genotypes. The occurrence of stepping was higher for the Friesland cows (53.9percent). The Friesland cows had the highest (P < 0.05) daily milk yield compared to Jersey and Crossbred cows. The present study revealed that behavioural activities of dairy cattle during parturition differed according to genotype and parity and the behavioural response of first lactating cows differ according to genotype during milking.
- Full Text:
- Date Issued: 2015
An investigation of source rocks and depositional environments on acid mine drainage in South African coal mines: a comparison of the main Karoo basin and sub-basins.
- Authors: Ncube, Lindani
- Date: 2015
- Subjects: Mine drainage -- Environmental aspects -- South Africa , Coal mines and mining -- Environmental aspects -- South Africa , Acid mine drainage -- Environmental aspects -- South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/19556 , vital:43139
- Description: The coal deposits have been and continue to be the primary source of energy in South Africa. The continuous use of coal presents many challenges that includes genesis of acid mine drainage (AMD) which is as a result of the oxidation of predominant pyrite (FeS2) and other sulphides. The aim of this study was to investigate the role of source rocks and their depositional environments on AMD generation in South African coal mine environments. Five collieries from five coalfields were selected as case studies: Brandspruit in the Highveld, Vaalkrantz in the Vryheid, the Elitheni in the Molteno-Indwe, the Arnot in the Witbank and the Malatleng Exploration Project in the Waterberg Coalfields. Brandspruit, Vaalkrantz and Elitheni Collieries are located in the Main Karoo Basin, while the Witbank and the Waterberg Coalfields are located in Sub-Basins. The study investigated a variety of indices such as palaeo-depositional environments, mineral assemblages, geochemical signatures, water quality parameters, acid base accounting (ABA) and water leach tests for the coal and associated non-coal strata. An effort was made to establish the relationship between the mineralogy of the studied lithologies and the associated water quality. The study resulted in delineation of detrital and diagenetic rock components and interpretation of source area of rock types and the origin and timing of diagenetic alterations. Sandstone units are prevalent, except in the Waterberg Coalfield where mudstones are prevalent. Classifications of the mineralogical composition with descriptive adjectives yield the rock names arkose to sub-arkose categories in the Main Karoo Basin, and sub-arenites to quartz arenites in the Sub-Basins with the sandstones of recycled origin. Further, the sandstones of the Main Karoo Basin are of mixed provenance whilst those of Sub-Basins represent cratonic interior provenance. Sandstone from the Main Karoo Basin generally exhibit high concentrations of feldspars, which favour either high relief, arid or arctic climates with less chemical weathering at the source area. The presence of glauconite in sediments of the Main Karoo Basin attests to a marine continental shelf depositional environment. Sediments of the Main Karoo Basin have high contents of tadpole-shaped pyrite in coal and non-coal strata as compared to sediments of the Sub-Basins. The observed pyrite is ascribed to early diagenetic origin, and is closely related to the generation of acid mining drainage. The sediments have experienced an involved sequence of diagenetic alterations. The alterations considered to be typical for sandstones in the Main Karoo Basin are calcite cementation, feldspar dissolution, kaolinite infilling, pyrite grain coatings, albitization and pressure solution; whereas, quartz overgrowth and clay matrix filling are characteristics of sediments of Sub-Basins. The sequence and distribution of these alterations are related to the source mineral composition, depositional environment, stratigraphic relationships and burial history of the sediments. A direct link exists among the depositional environments, the mineral assemblages and the geochemical compositions of the lithologies. SiO2 is the dominant major oxide and is abundant in coals from coalfields located in the Sub-Basins. Si, Al, Fe, Ca, S, Mg, K and Na show strong association with their discrete minerals. The sandstones are substantially enriched in elements that are chemically immobile and associated with terrigenous influx, such as SiO2, Al2O3, and TiO2. The observed high contents of SiO2 are probably due to source rocks and silicification. SiO2, Al2O3 and TiO2 are related to clay and heavy minerals, with elevated Fe2O3 (Total) content in sediments of the Main Karoo Basin ascribed to sulphidization. Sediments from the Main Karoo Basin are enriched in both Na2O and K2O due to albitization and muscovitization. Substantial concentrations of Ba, Rb and Zr are in accordance to the high amount of phyllosilicates and heavy minerals. Muscovitization contributes to the correlation of Rb and Ba with K2O. The shales are substantially depleted in SiO2, CaO, MgO, Na2O, K2O, TiO2 and Fe2O3 due to weathering and diagenetic alteration, but are enriched in Al2O3 and P2O5. The ABA test clearly indicates that sandstones from the Main Karoo Basin have a potential of generating AMD as they contain sufficient pyrite to generate acid, with the final pH values of the samples turning acidic upon complete oxidation of pyrite. On the contrary, sediments of SubBasins contain sufficient calcite that serves to limit the amount of acid generation. Both sandstone and coal from collieries representing the Main Karoo Basin are characterised by elevated contents of S percent in comparison to coal from collieries representing the Sub-Basins. In general, the quality of water is as a result of a combination of complex geochemical interactions that involves various ions from different sources. Water leaching test shows that the leachates have varied chemical compositions with pH values in the range of 4.5-9 for the sandstone, and 2– 8.9 for the coal leachates. Variations in the pH values are attributed to regional phenomena controlled by the mineralogical and hydrological environments. Furthermore, the variation in pH is ascribed to the presence of acid forming pyrite and acid neutralizing carbonate minerals that are highly reactive in the mining environment. Elements Na, Ca, Mg and K occur in non-compliant concentrations in both coal and non-coal leachates indicating their abundance in all of the lithologies. Na enrichment in the lithologies is associated with albite, clay minerals and Al-Ksulphate coatings. Elements Fe, Al, Cd and Pb are easily leached from the lithologies. According to the equilibrium model, gibbsite, cuprite, diaspore and boehmite are the supersaturated minerals in the lithologies. Influencing factors such as the mineralogical composition of rocks are reflected in the wide variation of pH, TDS, EC and the ion concentrations of the studied water samples. The pH of the studied areas is neutral to alkaline. High levels of TDS and EC are observed in the Brandspruit Colliery, which is due to dissolution of soluble salts from the rock sequence that the water passes through. The anion chemistry shows the dominance of SO4 2- in the surface and groundwater of Brandspruit, Vaalkrantz and Elitheni Collieries, whereas HCO3 - dominates in the Arnot Colliery. SO4 2- is ascribed to the oxidative weathering of pyrites. Cldominates in groundwater from the Arnot Colliery and the Waterberg Coalfield. The cation chemistry is dominated by Na+ in the surface and groundwater of the Brandspruit, Vaalkrantz and Elitheni Collieries. Mg2+ dominates in groundwater from the Arnot Colliery, while K+ dominates in the Waterberg Coalfield. Fe is highly enriched in water from the Brandspruit Colliery, and is linked to the oxidation of pyrite. Carbonates are the supersaturated minerals in the Sub-Basins whilst sulphates are supersaturated in the Main Karoo Basin. The research shows that variations in regional mineral distribution is a result of a palaeo-deposition environment that was of marine nature for the coal sequence in the Main Karoo Basin and of fresh water for the coal sequence in Sub-Basins. A direct link therefore exists between depositional environments, mineral assemblages and whole rock geochemistry. It can be concluded that AMD is directly linked to pyrite and other sulphides, the coal mines located in the Main Karoo Basin have the possibility to deteriorate surface- and ground-water quality and to generate AMD during the mining processes; coal miners need to seriously consider applying environmental protection measures when mining coal in the Main Karoo Basin. Whereas, coal mining in the Sub-Basins has low possibility of generating AMD and pollution. , Thesis (PhD) (Geology) -- University of Fort Hare, 2015
- Full Text:
- Date Issued: 2015
- Authors: Ncube, Lindani
- Date: 2015
- Subjects: Mine drainage -- Environmental aspects -- South Africa , Coal mines and mining -- Environmental aspects -- South Africa , Acid mine drainage -- Environmental aspects -- South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/19556 , vital:43139
- Description: The coal deposits have been and continue to be the primary source of energy in South Africa. The continuous use of coal presents many challenges that includes genesis of acid mine drainage (AMD) which is as a result of the oxidation of predominant pyrite (FeS2) and other sulphides. The aim of this study was to investigate the role of source rocks and their depositional environments on AMD generation in South African coal mine environments. Five collieries from five coalfields were selected as case studies: Brandspruit in the Highveld, Vaalkrantz in the Vryheid, the Elitheni in the Molteno-Indwe, the Arnot in the Witbank and the Malatleng Exploration Project in the Waterberg Coalfields. Brandspruit, Vaalkrantz and Elitheni Collieries are located in the Main Karoo Basin, while the Witbank and the Waterberg Coalfields are located in Sub-Basins. The study investigated a variety of indices such as palaeo-depositional environments, mineral assemblages, geochemical signatures, water quality parameters, acid base accounting (ABA) and water leach tests for the coal and associated non-coal strata. An effort was made to establish the relationship between the mineralogy of the studied lithologies and the associated water quality. The study resulted in delineation of detrital and diagenetic rock components and interpretation of source area of rock types and the origin and timing of diagenetic alterations. Sandstone units are prevalent, except in the Waterberg Coalfield where mudstones are prevalent. Classifications of the mineralogical composition with descriptive adjectives yield the rock names arkose to sub-arkose categories in the Main Karoo Basin, and sub-arenites to quartz arenites in the Sub-Basins with the sandstones of recycled origin. Further, the sandstones of the Main Karoo Basin are of mixed provenance whilst those of Sub-Basins represent cratonic interior provenance. Sandstone from the Main Karoo Basin generally exhibit high concentrations of feldspars, which favour either high relief, arid or arctic climates with less chemical weathering at the source area. The presence of glauconite in sediments of the Main Karoo Basin attests to a marine continental shelf depositional environment. Sediments of the Main Karoo Basin have high contents of tadpole-shaped pyrite in coal and non-coal strata as compared to sediments of the Sub-Basins. The observed pyrite is ascribed to early diagenetic origin, and is closely related to the generation of acid mining drainage. The sediments have experienced an involved sequence of diagenetic alterations. The alterations considered to be typical for sandstones in the Main Karoo Basin are calcite cementation, feldspar dissolution, kaolinite infilling, pyrite grain coatings, albitization and pressure solution; whereas, quartz overgrowth and clay matrix filling are characteristics of sediments of Sub-Basins. The sequence and distribution of these alterations are related to the source mineral composition, depositional environment, stratigraphic relationships and burial history of the sediments. A direct link exists among the depositional environments, the mineral assemblages and the geochemical compositions of the lithologies. SiO2 is the dominant major oxide and is abundant in coals from coalfields located in the Sub-Basins. Si, Al, Fe, Ca, S, Mg, K and Na show strong association with their discrete minerals. The sandstones are substantially enriched in elements that are chemically immobile and associated with terrigenous influx, such as SiO2, Al2O3, and TiO2. The observed high contents of SiO2 are probably due to source rocks and silicification. SiO2, Al2O3 and TiO2 are related to clay and heavy minerals, with elevated Fe2O3 (Total) content in sediments of the Main Karoo Basin ascribed to sulphidization. Sediments from the Main Karoo Basin are enriched in both Na2O and K2O due to albitization and muscovitization. Substantial concentrations of Ba, Rb and Zr are in accordance to the high amount of phyllosilicates and heavy minerals. Muscovitization contributes to the correlation of Rb and Ba with K2O. The shales are substantially depleted in SiO2, CaO, MgO, Na2O, K2O, TiO2 and Fe2O3 due to weathering and diagenetic alteration, but are enriched in Al2O3 and P2O5. The ABA test clearly indicates that sandstones from the Main Karoo Basin have a potential of generating AMD as they contain sufficient pyrite to generate acid, with the final pH values of the samples turning acidic upon complete oxidation of pyrite. On the contrary, sediments of SubBasins contain sufficient calcite that serves to limit the amount of acid generation. Both sandstone and coal from collieries representing the Main Karoo Basin are characterised by elevated contents of S percent in comparison to coal from collieries representing the Sub-Basins. In general, the quality of water is as a result of a combination of complex geochemical interactions that involves various ions from different sources. Water leaching test shows that the leachates have varied chemical compositions with pH values in the range of 4.5-9 for the sandstone, and 2– 8.9 for the coal leachates. Variations in the pH values are attributed to regional phenomena controlled by the mineralogical and hydrological environments. Furthermore, the variation in pH is ascribed to the presence of acid forming pyrite and acid neutralizing carbonate minerals that are highly reactive in the mining environment. Elements Na, Ca, Mg and K occur in non-compliant concentrations in both coal and non-coal leachates indicating their abundance in all of the lithologies. Na enrichment in the lithologies is associated with albite, clay minerals and Al-Ksulphate coatings. Elements Fe, Al, Cd and Pb are easily leached from the lithologies. According to the equilibrium model, gibbsite, cuprite, diaspore and boehmite are the supersaturated minerals in the lithologies. Influencing factors such as the mineralogical composition of rocks are reflected in the wide variation of pH, TDS, EC and the ion concentrations of the studied water samples. The pH of the studied areas is neutral to alkaline. High levels of TDS and EC are observed in the Brandspruit Colliery, which is due to dissolution of soluble salts from the rock sequence that the water passes through. The anion chemistry shows the dominance of SO4 2- in the surface and groundwater of Brandspruit, Vaalkrantz and Elitheni Collieries, whereas HCO3 - dominates in the Arnot Colliery. SO4 2- is ascribed to the oxidative weathering of pyrites. Cldominates in groundwater from the Arnot Colliery and the Waterberg Coalfield. The cation chemistry is dominated by Na+ in the surface and groundwater of the Brandspruit, Vaalkrantz and Elitheni Collieries. Mg2+ dominates in groundwater from the Arnot Colliery, while K+ dominates in the Waterberg Coalfield. Fe is highly enriched in water from the Brandspruit Colliery, and is linked to the oxidation of pyrite. Carbonates are the supersaturated minerals in the Sub-Basins whilst sulphates are supersaturated in the Main Karoo Basin. The research shows that variations in regional mineral distribution is a result of a palaeo-deposition environment that was of marine nature for the coal sequence in the Main Karoo Basin and of fresh water for the coal sequence in Sub-Basins. A direct link therefore exists between depositional environments, mineral assemblages and whole rock geochemistry. It can be concluded that AMD is directly linked to pyrite and other sulphides, the coal mines located in the Main Karoo Basin have the possibility to deteriorate surface- and ground-water quality and to generate AMD during the mining processes; coal miners need to seriously consider applying environmental protection measures when mining coal in the Main Karoo Basin. Whereas, coal mining in the Sub-Basins has low possibility of generating AMD and pollution. , Thesis (PhD) (Geology) -- University of Fort Hare, 2015
- Full Text:
- Date Issued: 2015
Multi linear regression-based modeling and performance monitoring of flat plate solar collector outlet temperature in Alice, South Africa
- Authors: Ndlovu, Nothando
- Date: 2015
- Subjects: Solar collectors Solar water heaters
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/12676 , vital:39298
- Description: In a period of rapidly increasing energy demand, the exploitation of abundantly available solar energy is imperative. Temperate climates like South Africa show good potential for utilizing solar-driven technologies such as solar water heaters. These systems offer an attractive alternative over conventional water geysers as a means to supply hot water for residential use. In South Africa, the solar water heater industry is growing rapidly as the government offers incentives manufactures and consumers. This necessitates the determination of performance of these systems through experimental analysis as well as performance prediction. This study evaluated the summer and winter performance of a flat plate, thermosyphon solar water heater under climatic conditions encountered in Alice, South Africa by considering the collector outlet temperature. The performance and weather data obtained were used to develop a multi linear regression (MLR) model for each season. MLR is a simple and easily applicable modelling approach which uses a set of input and output data to determine the model coefficients of a linear relation of two or more variables. The collector outlet temperature was correlated with solar radiation, ambient temperature, relative humidity, and collector inlet temperature since these variables have a direct impact on the collector temperature rise. Results from the performance showed that the collector performs well, attaining temperatures up to 87.2oC during the summer season and 70oC during winter season. The summer and winter percentage mean absolute error for the whole monitoring period were 4.07 percent and 6.2 percent respectively which indicate that MLR can be successfully applied to predict collector outlet temperatures in both seasons.
- Full Text:
- Date Issued: 2015
- Authors: Ndlovu, Nothando
- Date: 2015
- Subjects: Solar collectors Solar water heaters
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/12676 , vital:39298
- Description: In a period of rapidly increasing energy demand, the exploitation of abundantly available solar energy is imperative. Temperate climates like South Africa show good potential for utilizing solar-driven technologies such as solar water heaters. These systems offer an attractive alternative over conventional water geysers as a means to supply hot water for residential use. In South Africa, the solar water heater industry is growing rapidly as the government offers incentives manufactures and consumers. This necessitates the determination of performance of these systems through experimental analysis as well as performance prediction. This study evaluated the summer and winter performance of a flat plate, thermosyphon solar water heater under climatic conditions encountered in Alice, South Africa by considering the collector outlet temperature. The performance and weather data obtained were used to develop a multi linear regression (MLR) model for each season. MLR is a simple and easily applicable modelling approach which uses a set of input and output data to determine the model coefficients of a linear relation of two or more variables. The collector outlet temperature was correlated with solar radiation, ambient temperature, relative humidity, and collector inlet temperature since these variables have a direct impact on the collector temperature rise. Results from the performance showed that the collector performs well, attaining temperatures up to 87.2oC during the summer season and 70oC during winter season. The summer and winter percentage mean absolute error for the whole monitoring period were 4.07 percent and 6.2 percent respectively which indicate that MLR can be successfully applied to predict collector outlet temperatures in both seasons.
- Full Text:
- Date Issued: 2015
The electrical, structural and elemental analyis of degraded single junction amorphous silicon solar modules
- Osayemwenre, Gilbert Omorodion
- Authors: Osayemwenre, Gilbert Omorodion
- Date: 2015
- Subjects: Amorphous semiconductors , Solar cells , Silicon crystals
- Language: English
- Type: Thesis , Masters , Science
- Identifier: http://hdl.handle.net/10353/11674 , vital:39095
- Description: This study focuses on the degradation of solar cells due to localized heat. A decrease in optical absorbance represents a huge problem because of long-term solar cell degradation, decrease in absorption coefficient and a reduction in solar cell conversion efficiency. This decreases the photo-generating current hence reduces the effective efficiency of the solar device. As such the electrical output decreases, this research investigates the reduction in a-Si:H modules maximum power and its light absorption and correlates this with hot spot formation. Infrared Thermography was used for mapping of the module temperature profile, while IR flying meter software was used to analyze the hot spot centre. Fourier Transform Infrared Spectroscopy (FTIR) was used for absorption characterization. The study was undertaken during outdoor deployment of five PV modules. This method was chosen so as to deduce the practical effect of hot spot formation on the module’s absorption ability. The results show a direct correlation between localized heat and absorption degradation and structural degradation (damaged) in a-Si:H.
- Full Text:
- Date Issued: 2015
- Authors: Osayemwenre, Gilbert Omorodion
- Date: 2015
- Subjects: Amorphous semiconductors , Solar cells , Silicon crystals
- Language: English
- Type: Thesis , Masters , Science
- Identifier: http://hdl.handle.net/10353/11674 , vital:39095
- Description: This study focuses on the degradation of solar cells due to localized heat. A decrease in optical absorbance represents a huge problem because of long-term solar cell degradation, decrease in absorption coefficient and a reduction in solar cell conversion efficiency. This decreases the photo-generating current hence reduces the effective efficiency of the solar device. As such the electrical output decreases, this research investigates the reduction in a-Si:H modules maximum power and its light absorption and correlates this with hot spot formation. Infrared Thermography was used for mapping of the module temperature profile, while IR flying meter software was used to analyze the hot spot centre. Fourier Transform Infrared Spectroscopy (FTIR) was used for absorption characterization. The study was undertaken during outdoor deployment of five PV modules. This method was chosen so as to deduce the practical effect of hot spot formation on the module’s absorption ability. The results show a direct correlation between localized heat and absorption degradation and structural degradation (damaged) in a-Si:H.
- Full Text:
- Date Issued: 2015
Socio-economic factors influencing apiculture in the Eastern Cape province, South Africa
- Authors: Peter, Luntulwandile
- Date: 2015
- Subjects: Bee culture -- South Africa -- Eastern Cape Honey -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/15321 , vital:40362
- Description: The aim of this study was to assess socio-economic factors influencing apiculture in the Eastern Cape Province. In addition, production costs and profitability of beekeeping were determined, and opportunities and challenges to beekeeping were identified. The data was generated from 58 individual interviews using pre-tested structured questionnaires and checklists. This was supplemented by secondary data collected from different published and unpublished sources. Gross margin analysis was employed to examine the income contribution of honey production to household income, and a Linear Regression Model was used to identify the determinants of honey production. Of the twelve variables included in the regression model, only six were found to be statistically significant. These were gender of the beekeeper, access to credit, availability of labour, price of honey, distance to the market, and number of bee colonies owned. On average, each beekeeper owned and operated 35 bee colonies, with an average production of 9 kg of honey per colony per annum; the latter is well beyond a potential production of 35 kg per colony per annum. Beekeeping contributed an average of R12 231.80 per beekeeping household per annum. Except for the honey, no other bee products were produced and marketed. The beekeepers could access the market (retailers and consumers) readily and efficiently; the latter having been determined through calculation and analysing marketing margins. The major constraints to production identified and prioritised by beekeepers in the study area were drought, pests and insects, the shortage of bee forage, and the lack of adequate beekeeping skills. Based on the study results, interventions required to raise the marketable supply of honey produce are recommended.
- Full Text:
- Date Issued: 2015
- Authors: Peter, Luntulwandile
- Date: 2015
- Subjects: Bee culture -- South Africa -- Eastern Cape Honey -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/15321 , vital:40362
- Description: The aim of this study was to assess socio-economic factors influencing apiculture in the Eastern Cape Province. In addition, production costs and profitability of beekeeping were determined, and opportunities and challenges to beekeeping were identified. The data was generated from 58 individual interviews using pre-tested structured questionnaires and checklists. This was supplemented by secondary data collected from different published and unpublished sources. Gross margin analysis was employed to examine the income contribution of honey production to household income, and a Linear Regression Model was used to identify the determinants of honey production. Of the twelve variables included in the regression model, only six were found to be statistically significant. These were gender of the beekeeper, access to credit, availability of labour, price of honey, distance to the market, and number of bee colonies owned. On average, each beekeeper owned and operated 35 bee colonies, with an average production of 9 kg of honey per colony per annum; the latter is well beyond a potential production of 35 kg per colony per annum. Beekeeping contributed an average of R12 231.80 per beekeeping household per annum. Except for the honey, no other bee products were produced and marketed. The beekeepers could access the market (retailers and consumers) readily and efficiently; the latter having been determined through calculation and analysing marketing margins. The major constraints to production identified and prioritised by beekeepers in the study area were drought, pests and insects, the shortage of bee forage, and the lack of adequate beekeeping skills. Based on the study results, interventions required to raise the marketable supply of honey produce are recommended.
- Full Text:
- Date Issued: 2015
Stratigraphy, geochemistry and origin of the manganese ore deposit in Carletonville, North West province of South Africa
- Authors: Pharoe, Benedict Kinshasa
- Date: 2015
- Subjects: Geology, Stratigraphic Geology--South Africa Geochemistry--South Africa
- Language: English
- Type: Thesis , Masters , Geology
- Identifier: http://hdl.handle.net/10353/11641 , vital:39092
- Description: The Carletonville manganese ore-deposit is a Neogene weathered nodule deposit which was developed on the Early Proterozoic Malmani dolomite succession of the Transvaal Supergroup in Carletonville area, North-West Province, South Africa. The deposits were formed from surficial weathering of the underlying Mn-rich dolomites of the Malmani Subgroup and some were formed from weathered Mn-rich Tertiary alluvial-fluvial sediments. These deposits are currently mineralized and hosted in modern Mn-Fe rich soil profiles and occurs at shallow depths, thus the ore is suitable to be mined by open-cast mining. The study dealt with the stratigraphy, petrology, geochemistry, diagenesis and origin of the ore-deposit. The stratigraphic profile of the manganese ore-deposit was subdivided into 8 zones, namely the (A, B, C, D, E, F, G, and H) zones from the surface downwards. On the basis of variation in mineralogical and chemical composition, nodule grain sizes and the zonation colour, the above mentioned zones were further integrated into the Upper (A and B), Middle (C, D and E) and Lower (F, G and H) Zone, with the I zone, the basement zone, representing the underlying Malmani Subgroup stromatolitic dolomite. The Upper Zone represents organic rich, fine grain silty soil which caps the stratigraphic succession in the mine area. Mineralogically, these zones are depleted in manganese and comprises of hematite, kaolinite, micas and quartz grains, with Mn-Fe coated terrigenous clasts concentrated at the lowermost portion of the B-zone along the contact with the underlying zones. The Middle Zone is characteristically medium to fine in grain sizes with reddish colour due to intense weathering of iron minerals to hematite and is depleted in Ca, Na and Mg bearing minerals as a result of dissolution and leaching and is highly concentrated in quartz and caliche fragments. The Lower Zone is coarse grained with dark, reddish-brown colour. The Middle and Lower Zones comprise mainly of Mn and Fe oxides, clays, quartz, limonite, micas and caliche patches. The concentration of manganese is, however, not consistent in these zones from one borehole to the next, it deviates with topography and depth. The overall stratigraphic succession in the mine area can be described as characterizing of basal stromatolitic dolomite of the Malmani Subgroup, overlain by zone of black, powder-like manganiferous wad which is in turn overlain by weathered Mn-rich Tertiary alluvial-fluvial sediments hosting manganiferous nodules. The whole succession is covered by Quaternary sands. The studies undertaken on grain size analysis for the determination of variation in nodule grain sizes with increasing depth along the profile has indicated a perfect variation trend in grain sizes, where the underlying Lower Zone characterizes of coarse grain fraction whilst the overlying Middle Zone is mainly medium to fine grained and the Upper Zone comprise of very fine silt soil. Statistical parameters were used to classify these sediments under Udden-Wentworth grain size classification scheme. Based on these parameters the samples were classified as pebbles and/or gravel on GRADISTAT program and were found to be moderately to poorly sorted, positively skewed with moderate kurtosis and displays a bimodal distribution. Mineralogical analysis with X-Ray Diffraction and petrographic studies indicates that cryptomelane (KMn8 O16) is the major manganese mineral, whereas pyrolusite occurs as a minor manganese mineral in the mine. Other mineral constituents include hematite/goethite, clay minerals, muscovite, quartz, calcite, limonite with minor amount of heavy minerals. The modal composition studies carried out on the terrigenous clasts which are coated on surface by Mn-Fe oxide concentric laminae indicated their nature to be sub-arkoses and quartz arenites. These clasts are found to occur in association with manganiferous nodules in the mine area, with high concentration experienced at the uppermost portion of the profile below the top soil. The provenance studies indicates the source of these terrigenous sediments from cratonic interior to recycle orogen at low plains with a temperate and subhumid climate and on tropical, humid conditions within an area of moderate to low relief. Based on the geochemical studies, different manganese classification schemes were adopted in this study and inferences were made from geochemical data which indicated supergene and hydrogenous source of the Carletonville manganese nodules suggesting precipitation from weathering residues of Malmani dolomite at passive continental margin of tectonic provenance, with temperate and tropical to humid climatic conditions. The diagenetic features were broadly divided into early, mid and uplift diagenetic stage. Early stage includes sediment consolidation which characterized of cementation and neomorphism in carbonate sediments. This period was followed by mid (burial diagenesis) stage which brought about an increase in tightness of grain packing, loss of pore spaces and thinning of beds due to weight of overlying sediments and selective dissolution of framework grains. Mineral dissolution and replacement were common factors during this stage. In the last diagenetic stage, rocks were uplifted, weathered and unroofed by erosion bringing mineral assemblage including newly formed diagenetic minerals into environment of low temperature and pressure, and high oxygen environment.
- Full Text:
- Date Issued: 2015
- Authors: Pharoe, Benedict Kinshasa
- Date: 2015
- Subjects: Geology, Stratigraphic Geology--South Africa Geochemistry--South Africa
- Language: English
- Type: Thesis , Masters , Geology
- Identifier: http://hdl.handle.net/10353/11641 , vital:39092
- Description: The Carletonville manganese ore-deposit is a Neogene weathered nodule deposit which was developed on the Early Proterozoic Malmani dolomite succession of the Transvaal Supergroup in Carletonville area, North-West Province, South Africa. The deposits were formed from surficial weathering of the underlying Mn-rich dolomites of the Malmani Subgroup and some were formed from weathered Mn-rich Tertiary alluvial-fluvial sediments. These deposits are currently mineralized and hosted in modern Mn-Fe rich soil profiles and occurs at shallow depths, thus the ore is suitable to be mined by open-cast mining. The study dealt with the stratigraphy, petrology, geochemistry, diagenesis and origin of the ore-deposit. The stratigraphic profile of the manganese ore-deposit was subdivided into 8 zones, namely the (A, B, C, D, E, F, G, and H) zones from the surface downwards. On the basis of variation in mineralogical and chemical composition, nodule grain sizes and the zonation colour, the above mentioned zones were further integrated into the Upper (A and B), Middle (C, D and E) and Lower (F, G and H) Zone, with the I zone, the basement zone, representing the underlying Malmani Subgroup stromatolitic dolomite. The Upper Zone represents organic rich, fine grain silty soil which caps the stratigraphic succession in the mine area. Mineralogically, these zones are depleted in manganese and comprises of hematite, kaolinite, micas and quartz grains, with Mn-Fe coated terrigenous clasts concentrated at the lowermost portion of the B-zone along the contact with the underlying zones. The Middle Zone is characteristically medium to fine in grain sizes with reddish colour due to intense weathering of iron minerals to hematite and is depleted in Ca, Na and Mg bearing minerals as a result of dissolution and leaching and is highly concentrated in quartz and caliche fragments. The Lower Zone is coarse grained with dark, reddish-brown colour. The Middle and Lower Zones comprise mainly of Mn and Fe oxides, clays, quartz, limonite, micas and caliche patches. The concentration of manganese is, however, not consistent in these zones from one borehole to the next, it deviates with topography and depth. The overall stratigraphic succession in the mine area can be described as characterizing of basal stromatolitic dolomite of the Malmani Subgroup, overlain by zone of black, powder-like manganiferous wad which is in turn overlain by weathered Mn-rich Tertiary alluvial-fluvial sediments hosting manganiferous nodules. The whole succession is covered by Quaternary sands. The studies undertaken on grain size analysis for the determination of variation in nodule grain sizes with increasing depth along the profile has indicated a perfect variation trend in grain sizes, where the underlying Lower Zone characterizes of coarse grain fraction whilst the overlying Middle Zone is mainly medium to fine grained and the Upper Zone comprise of very fine silt soil. Statistical parameters were used to classify these sediments under Udden-Wentworth grain size classification scheme. Based on these parameters the samples were classified as pebbles and/or gravel on GRADISTAT program and were found to be moderately to poorly sorted, positively skewed with moderate kurtosis and displays a bimodal distribution. Mineralogical analysis with X-Ray Diffraction and petrographic studies indicates that cryptomelane (KMn8 O16) is the major manganese mineral, whereas pyrolusite occurs as a minor manganese mineral in the mine. Other mineral constituents include hematite/goethite, clay minerals, muscovite, quartz, calcite, limonite with minor amount of heavy minerals. The modal composition studies carried out on the terrigenous clasts which are coated on surface by Mn-Fe oxide concentric laminae indicated their nature to be sub-arkoses and quartz arenites. These clasts are found to occur in association with manganiferous nodules in the mine area, with high concentration experienced at the uppermost portion of the profile below the top soil. The provenance studies indicates the source of these terrigenous sediments from cratonic interior to recycle orogen at low plains with a temperate and subhumid climate and on tropical, humid conditions within an area of moderate to low relief. Based on the geochemical studies, different manganese classification schemes were adopted in this study and inferences were made from geochemical data which indicated supergene and hydrogenous source of the Carletonville manganese nodules suggesting precipitation from weathering residues of Malmani dolomite at passive continental margin of tectonic provenance, with temperate and tropical to humid climatic conditions. The diagenetic features were broadly divided into early, mid and uplift diagenetic stage. Early stage includes sediment consolidation which characterized of cementation and neomorphism in carbonate sediments. This period was followed by mid (burial diagenesis) stage which brought about an increase in tightness of grain packing, loss of pore spaces and thinning of beds due to weight of overlying sediments and selective dissolution of framework grains. Mineral dissolution and replacement were common factors during this stage. In the last diagenetic stage, rocks were uplifted, weathered and unroofed by erosion bringing mineral assemblage including newly formed diagenetic minerals into environment of low temperature and pressure, and high oxygen environment.
- Full Text:
- Date Issued: 2015
A comparative economic analysis of small scale tobacco production under contract and non-contract farming : the case of Marondera rural district, Mashonaland East province, Zimbabwe
- Authors: Ruzhani, Freddy
- Date: 2015
- Subjects: Farms, Small -- Zimbabwe Tobacco industry -- Zimbabwe Farmers -- Zimbabwe
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/12653 , vital:39296
- Description: Constitutionalism and separation of powers is the most dynamic topic worldwide. Montesquieu, the French philosopher is credited with the doctrine of separation of powers. Various countries adopted the doctrine and modified it, in order to fit their systems of governments. The reason behind is that there is no universally recognized model of separation of powers or one size fit all. Countries apply this doctrine differently in a fashion that fits their domestic laws and constitutional requirements. Montesquieu gave a classic exposition and the rationale for separation of powers in one of his well-celebrated work “The Spirit of Laws”. The concept of separation of powers emerged premised on the theory that the arms of state namely, the judiciary, the legislature and the executive, should operate within their providence without one interfering with the other. From the South African perspective, the Constitution of South Africa of 1996 requires separation of powers even though it is not explicitly so stated in the text. This research examines the unique South African model of separation of powers and how the courts have navigated through it from the time the Constitution was promulgated. It seeks to establish whether or not a South African model of separation of powers has come to the fore. The research further examines the problem of interference amongst the arms of state and mechanism of checks and balances which can be applied to prevent or minimise such interference. In doing so, the study pursued a desktop survey of primary and secondary materials, including scientific literature, legislation, courts’ jurisprudence, and official documents. A comparative perspective was also made in order to learn from the experiences of other jurisdictions where the doctrine is applied. The findings reveal that South Africa has a unique model of separation of powers. The model was learned and enriched from various foreign jurisdictions. The courts have contributed enormously to this model, which contrive to be fluid and living.
- Full Text:
- Date Issued: 2015
- Authors: Ruzhani, Freddy
- Date: 2015
- Subjects: Farms, Small -- Zimbabwe Tobacco industry -- Zimbabwe Farmers -- Zimbabwe
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/12653 , vital:39296
- Description: Constitutionalism and separation of powers is the most dynamic topic worldwide. Montesquieu, the French philosopher is credited with the doctrine of separation of powers. Various countries adopted the doctrine and modified it, in order to fit their systems of governments. The reason behind is that there is no universally recognized model of separation of powers or one size fit all. Countries apply this doctrine differently in a fashion that fits their domestic laws and constitutional requirements. Montesquieu gave a classic exposition and the rationale for separation of powers in one of his well-celebrated work “The Spirit of Laws”. The concept of separation of powers emerged premised on the theory that the arms of state namely, the judiciary, the legislature and the executive, should operate within their providence without one interfering with the other. From the South African perspective, the Constitution of South Africa of 1996 requires separation of powers even though it is not explicitly so stated in the text. This research examines the unique South African model of separation of powers and how the courts have navigated through it from the time the Constitution was promulgated. It seeks to establish whether or not a South African model of separation of powers has come to the fore. The research further examines the problem of interference amongst the arms of state and mechanism of checks and balances which can be applied to prevent or minimise such interference. In doing so, the study pursued a desktop survey of primary and secondary materials, including scientific literature, legislation, courts’ jurisprudence, and official documents. A comparative perspective was also made in order to learn from the experiences of other jurisdictions where the doctrine is applied. The findings reveal that South Africa has a unique model of separation of powers. The model was learned and enriched from various foreign jurisdictions. The courts have contributed enormously to this model, which contrive to be fluid and living.
- Full Text:
- Date Issued: 2015
Glycolytic potential and meat quality from dorper and merino sheep slaughtered at a commercial abattoir
- Authors: Stempa, Thuthuzelwa
- Date: 2015
- Subjects: Slaughtering and slaughter-houses Meat -- Quality
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/15310 , vital:40361
- Description: The objective of the study was to determine glycolytic potential and meat quality from Dorper and Merino sheep of both sexes slaughtered at a commercial abattoir. Dorper (n=52) and Merino (n= 48) breeds aged eight years, consisting of 50 intact rams and 50 non-pregnant ewes were used in the study. The sheep used in the study were reared, transported and lairised under identical conditions. Blood samples were collected at exsanguination for the measurement of glucose, lactate and cortisol levels. Samples were also collected from the Muscularis longmissius thoracis et lumborum (LTL) for the measurement glycogen, lactate levels, pH decline and colour. Correlations amongst blood stress indicators, muscle metabolites and meat quality attributes were also determined. Sex and breed had no effect on muscle glycolytic potential, glycogen and lactate levels from Dorper and Merino sheep of both sexes at the abattoir. Although sex and breed had an effect on pre-slaughter stress indicators (lactate and cortisol) collected at exsanguination. Ewes had higher levels of blood lactate (7.4 3 ± 0.49 mmol/L) and cortisol (293.92 ± 14.32 nmol/L) than the rams which had (5.19 ± 0.49 mmol/L) and (179.50 ± 14.32 nmol/L) lactate and cortisol levels, respectively. Furthermore, higher levels of lactate were observed in Dorper (7.54 ± 0.42 mmol/L) compared to the Merino sheep (4.97 ± 0.49 mmol/L). Meat pH decline and colour were also significantly affected by sex and breed. Ewes had higher levels of at pH45 minutes post slaughter (7.05 ± 0.04), pH3 hours (6.45 ± 0.04) , pH24 hours (6.00 ± 0.03), a* (14.31 ± 0.33) , b* (8.84 ± 0.29), H* (31.47 ± 0.73) and C* (16.75 ± 0.24) compared to the rams which had pH45 minutes (6.44 ± 0.04), pH3 hours (6.12 ± 0.04), pH24 hours (5.88 ± 0.03), a* (12.25 ± 0.33), b* (7.00 ± 0.29), H* (29.36 ± 0.73) and C* (14.15 ± 0.42) values. Moreover, Merino sheep had higher levels of L* (38.17 ± 0.48) and H* (31.59 ± 0.74) compared to the Dorper which had (36.39 ± 0.46) and (29.33 ± 0.71) L* and H* values, respectively. Blood cortisol was also positively correlated (P < 0.05) to glucose (r = 0.27), lactate (r = 0.37) but was negatively correlated (P < 0.001) to meat lightness (r = -0.44). Furthermore, blood cortisol was positively correlated (P < 0.001) to pH45 (r = 0.34), pH24 (r =0.22), meat yellowness (r = 0.24) and chroma (r = 0.37), but was negatively correlated to meat lightness (r = -0.47). Glycolytic potential was positively correlated (P < 0.001) to muscle glycogen levels (r = 0.66) and muscle lactate (r = 0.71).
- Full Text:
- Date Issued: 2015
- Authors: Stempa, Thuthuzelwa
- Date: 2015
- Subjects: Slaughtering and slaughter-houses Meat -- Quality
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/15310 , vital:40361
- Description: The objective of the study was to determine glycolytic potential and meat quality from Dorper and Merino sheep of both sexes slaughtered at a commercial abattoir. Dorper (n=52) and Merino (n= 48) breeds aged eight years, consisting of 50 intact rams and 50 non-pregnant ewes were used in the study. The sheep used in the study were reared, transported and lairised under identical conditions. Blood samples were collected at exsanguination for the measurement of glucose, lactate and cortisol levels. Samples were also collected from the Muscularis longmissius thoracis et lumborum (LTL) for the measurement glycogen, lactate levels, pH decline and colour. Correlations amongst blood stress indicators, muscle metabolites and meat quality attributes were also determined. Sex and breed had no effect on muscle glycolytic potential, glycogen and lactate levels from Dorper and Merino sheep of both sexes at the abattoir. Although sex and breed had an effect on pre-slaughter stress indicators (lactate and cortisol) collected at exsanguination. Ewes had higher levels of blood lactate (7.4 3 ± 0.49 mmol/L) and cortisol (293.92 ± 14.32 nmol/L) than the rams which had (5.19 ± 0.49 mmol/L) and (179.50 ± 14.32 nmol/L) lactate and cortisol levels, respectively. Furthermore, higher levels of lactate were observed in Dorper (7.54 ± 0.42 mmol/L) compared to the Merino sheep (4.97 ± 0.49 mmol/L). Meat pH decline and colour were also significantly affected by sex and breed. Ewes had higher levels of at pH45 minutes post slaughter (7.05 ± 0.04), pH3 hours (6.45 ± 0.04) , pH24 hours (6.00 ± 0.03), a* (14.31 ± 0.33) , b* (8.84 ± 0.29), H* (31.47 ± 0.73) and C* (16.75 ± 0.24) compared to the rams which had pH45 minutes (6.44 ± 0.04), pH3 hours (6.12 ± 0.04), pH24 hours (5.88 ± 0.03), a* (12.25 ± 0.33), b* (7.00 ± 0.29), H* (29.36 ± 0.73) and C* (14.15 ± 0.42) values. Moreover, Merino sheep had higher levels of L* (38.17 ± 0.48) and H* (31.59 ± 0.74) compared to the Dorper which had (36.39 ± 0.46) and (29.33 ± 0.71) L* and H* values, respectively. Blood cortisol was also positively correlated (P < 0.05) to glucose (r = 0.27), lactate (r = 0.37) but was negatively correlated (P < 0.001) to meat lightness (r = -0.44). Furthermore, blood cortisol was positively correlated (P < 0.001) to pH45 (r = 0.34), pH24 (r =0.22), meat yellowness (r = 0.24) and chroma (r = 0.37), but was negatively correlated to meat lightness (r = -0.47). Glycolytic potential was positively correlated (P < 0.001) to muscle glycogen levels (r = 0.66) and muscle lactate (r = 0.71).
- Full Text:
- Date Issued: 2015
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