Examining the nature of entrepreneurship within the towns and rural areas of Sakhisizwe Local Municipality, Eastern Cape
- Authors: Maliwa, Noluvuyo
- Date: 2022-11
- Subjects: Entrepreneurship , Developing countries--Economic conditions , Small business
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/27555 , vital:69315
- Description: Entrepreneurship plays an important role in societies around the world because it supports economic growth and creates job opportunities. This study investigated the nature of entrepreneurship in three distinct parts of Sakhisizwe Local Municipality, including a town within Sakhisizwe’s former homeland area, rural communities within its former homeland area, and a town within an area characterised by large-scale commercial farms. The study sought to establish the share of adults in the different parts of the municipality involved in entrepreneurship, to identify factors that contribute to the decision to become an entrepreneur, and to examine strategies pursued by, and challenges experienced, different types of entrepreneurs. The study involved a random sample of 362 respondents and both quantitative and qualitative data analysis. Among the main findings is that the proportion of adults involved in enterprise in Sakhisizwe is higher than found by other studies for South Africa as a whole, but is especially high for those living in the town in the former homeland area. While those residing in rural communities also engage in enterprise, they are generally compelled to practice their enterprises in town, thus have the disadvantage of needing frequent transport. While residing in the town in the commercial farming area is not disadvantageous in the same way, the challenge is that the town itself is able to support relatively few entrepreneurs due to fewer people coming to town for their shopping. , Thesis (MSci) -- Faculty of Science and Agricultures, 2022
- Full Text:
- Date Issued: 2022-11
- Authors: Maliwa, Noluvuyo
- Date: 2022-11
- Subjects: Entrepreneurship , Developing countries--Economic conditions , Small business
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/27555 , vital:69315
- Description: Entrepreneurship plays an important role in societies around the world because it supports economic growth and creates job opportunities. This study investigated the nature of entrepreneurship in three distinct parts of Sakhisizwe Local Municipality, including a town within Sakhisizwe’s former homeland area, rural communities within its former homeland area, and a town within an area characterised by large-scale commercial farms. The study sought to establish the share of adults in the different parts of the municipality involved in entrepreneurship, to identify factors that contribute to the decision to become an entrepreneur, and to examine strategies pursued by, and challenges experienced, different types of entrepreneurs. The study involved a random sample of 362 respondents and both quantitative and qualitative data analysis. Among the main findings is that the proportion of adults involved in enterprise in Sakhisizwe is higher than found by other studies for South Africa as a whole, but is especially high for those living in the town in the former homeland area. While those residing in rural communities also engage in enterprise, they are generally compelled to practice their enterprises in town, thus have the disadvantage of needing frequent transport. While residing in the town in the commercial farming area is not disadvantageous in the same way, the challenge is that the town itself is able to support relatively few entrepreneurs due to fewer people coming to town for their shopping. , Thesis (MSci) -- Faculty of Science and Agricultures, 2022
- Full Text:
- Date Issued: 2022-11
Potential effects of different salinities on the survival of the mangrove crab, Uca urvillei and its associated chemoautotrophic bacterial symbionts
- Mbobo, Tumeka https://orcid.org/0000-0002-0159-6569
- Authors: Mbobo, Tumeka https://orcid.org/0000-0002-0159-6569
- Date: 2015-06
- Subjects: Mangrove ecology http://id.loc.gov/authorities/subjects/sh85080528 , Crabs--South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/19225 , vital:43033
- Description: The ability of natural populations to maintain fitness is important to their long-term persistence and has further relevance in the light of climate change scenarios. Fitness is however also influenced strongly by interactions with other species of the community. It is, therefore, important to focus on how environmental change can alter key biological interactions. The present study aimed to investigate the effects of different salinity levels on one species of mangrove crab, Uca urvillei and the associated chemoautotrophic bacterial symbionts, from the Mngazana estuary, South Africa. To examine the influence of different salinities over time on the symbiotic bacterial community, salinity experiments were set up, choosing three salinity exposures (5, 20 and 35percent) and four time exposures (3, 7, 14 and 21 days). The results showed that microbial community associated with U. urvillei was generally stable throughout the three salinity treatments, while the survival of the host (crab), was influenced by high salinities, particularly after day 14. Overall, the results of this study suggest that over time, environmental salinity (35percent) has the potential to affect significantly the physiology of U. urvillei, but this might not necessarily be the case for the associated microbial communities. The modes at which the significant symbionts are transferred from mother to offspring were also investigated by analysing the bacterial profiles from eggs, ovigerous and non-ovigerous females, along with mud. The results were fairly complex, but with significant differences in the bacterial communities of eggs from mud and females. These differences were driven mostly by two dominant phyla: Actinobacteria and Proteobacteria. The presence of both these phyla throughout the categories (even though in different percentages) suggest that U. urvillei might employ a mixed mode strategy of acquiring and maintaining the bacterial symbionts. Overall, this study contributes to further understand the dynamic and complex effects of environmental Abstract ii change on symbiotic communities, with overall potential cascading repercussions to the persistence of mangrove systems. , Thesis (MSc) (Zoology) -- Faculty of Science and Agriculture, 2015
- Full Text:
- Date Issued: 2015-06
- Authors: Mbobo, Tumeka https://orcid.org/0000-0002-0159-6569
- Date: 2015-06
- Subjects: Mangrove ecology http://id.loc.gov/authorities/subjects/sh85080528 , Crabs--South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/19225 , vital:43033
- Description: The ability of natural populations to maintain fitness is important to their long-term persistence and has further relevance in the light of climate change scenarios. Fitness is however also influenced strongly by interactions with other species of the community. It is, therefore, important to focus on how environmental change can alter key biological interactions. The present study aimed to investigate the effects of different salinity levels on one species of mangrove crab, Uca urvillei and the associated chemoautotrophic bacterial symbionts, from the Mngazana estuary, South Africa. To examine the influence of different salinities over time on the symbiotic bacterial community, salinity experiments were set up, choosing three salinity exposures (5, 20 and 35percent) and four time exposures (3, 7, 14 and 21 days). The results showed that microbial community associated with U. urvillei was generally stable throughout the three salinity treatments, while the survival of the host (crab), was influenced by high salinities, particularly after day 14. Overall, the results of this study suggest that over time, environmental salinity (35percent) has the potential to affect significantly the physiology of U. urvillei, but this might not necessarily be the case for the associated microbial communities. The modes at which the significant symbionts are transferred from mother to offspring were also investigated by analysing the bacterial profiles from eggs, ovigerous and non-ovigerous females, along with mud. The results were fairly complex, but with significant differences in the bacterial communities of eggs from mud and females. These differences were driven mostly by two dominant phyla: Actinobacteria and Proteobacteria. The presence of both these phyla throughout the categories (even though in different percentages) suggest that U. urvillei might employ a mixed mode strategy of acquiring and maintaining the bacterial symbionts. Overall, this study contributes to further understand the dynamic and complex effects of environmental Abstract ii change on symbiotic communities, with overall potential cascading repercussions to the persistence of mangrove systems. , Thesis (MSc) (Zoology) -- Faculty of Science and Agriculture, 2015
- Full Text:
- Date Issued: 2015-06
Integration of nanostructured metal sulfides into titanium (iv) oxide for high performance dye sensitized solar cell
- Adedoyin Mojeed Agoro https://orcid.org/0000-0002-0434-9635
- Authors: Adedoyin Mojeed Agoro https://orcid.org/0000-0002-0434-9635
- Date: 2020-01
- Subjects: Nanostructured materials , Sulfur compounds
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/21523 , vital:48857
- Description: The work in this thesis describes synthesis, characterization and integration of nanostructured metal sulfides into titanium (IV) oxide for high performance dye sensitized solar cell. The synthesised single source precursors were evaluated using TGA, FTIR, , UV-Vis, PL,1H and 13CNMR, SEM, EDS, HRTEM, XRD, AFM, Raman, I-V, CV, Bode plot and EIS. TGA revealed the thermal degradation and quantified the mass percentage of metal sulphides as 33percent, 45percent and 27percent for CuS, PbS and SnS nanoparticles, respectively. FTIR analysis showed bands at 1580-1450 cm-1, and 1060-940 cm-1 tentatively assigned to C-N and C-S stretching frequencies correspondingly. The (M-S) stretching was observed at 577-406 cm-1 for the complexes using bis(N-di-isopropyl-N-octyldithiocarbamato) as primary ligands. IR spectra of bis(N-1,4-phenyl-N-(4-morpholinedithiocarbamato) as secondary ligands suggested the presence of (C-N) vibrations at 1508-1513 cm-1 for the complexes and 1507-1584 cm-1 for the ligands. The bands in the region of 973-1030 cm-1 were assigned to the complexes and 974- 983 cm-1 were attributed to the ligands, whereas vibration frequencies at 416-625 cm-1 were Nelson's Choice were included in these preliminary variety trials (PVTs) as checks. Twenty-five hybrids expressing high values for the Smith – Hazel selection index were identified across sites over years. Among those hybrids were two checks, namely Q16 (PAN5Q649R) and Q33 (Phb31MO7BR). The top five high – yielding hybrids selected based on the selection index were considered to be the most productive, stable and adaptable based on the GGE biplot and AMMI stability values. None of these single cross hybrids over yielded the best hybrid check (Q16) in the current study. A high potential environment, Centane, was the ideal environments for evaluating genotypes in the present study. The studies showed inbred lines L22, L23, L26, L28, L25, L29 and L31 to be low N stress tolerant at 0 kg N ha-1 based on the low N stress tolerance indices under glasshouse and the field conditions; they were also among the top ten grain-yielders under field conditions at 0 kg N ha-1. Also, in the NUE study, they were found to be among the top ten most N-efficient inbred lines under low N soils, under 30 kg N ha-1, and were among the top twenty-four inbred lines with high NUE values across the N levels in the study. Inbred lines L29 and L22 also produced testcross hybrids that were among the top twenty based on GY under 0 kg N ha-1. The testcross hybrids produced from these inbred lines were also among the top twenty-five with outstanding SCA effects for GY. These inbred lines were also parental lines of some of the top twenty- five best hybrids selected based on the Smith – Hazel selection index in the PVT study. Inbred lines L22, L23, L26, L28, L25, L29 and L31 can therefore further be evaluated and used as sources of N-tolerance genes in QPM breeding programs. tentatively assigned to M-S bond in the complexes. UV-Vis spectroscopy analysis for the complexes and from primary and secondary ligands are between within the range of 338 – 340 nm. PL studies of the primary ligands with metal complexes indicated emissions at 464 nm, 462 nm, 462 nm for Pb(II) and Sn(II), and Cu(II). The presence of secondary ligands was revealed by the absorption peaks at 455, 456 and 457 nm, exhibiting both the signals and chemical constituents of the respective ligands and their corresponding complexes. The electrochemistry in chapters 3 and 4 reveals that phase angle in the Bode plots changes with frequencies for Sn(II) complexes at 58, 57 and 8 respectively. Bode plots showed remarkable electronics of Cu(II) and Pb(II) complex interfaces. The CV curves exhibit two kinds of redox peaks indicating reduction at the negative potentials and oxidation at the positive potentials. The EIS, electrodes produced Rct for Pb(II), Cu(II) and Sn(II) electrodes in chapter 3. Moreover The EIS revealed that Sn(II) sensitizer displaced a stronger chemical capacitance and improved efficiency which could lead to better electron lifetime yield. The obtained CV exhibited anodic and cathodic peaks for Pb(II), connoting a reduction in Pb2+ and oxidation in Pb2-. Bode plot phase angle displayed Sn(II) and Pb(II) with maxima phase, indicating the presence of time constants of the electrode processes in Bis(N-1,4-Phenyl-N-Morhpo-dithiocarbamato bis(Mo/1,4-PHDTC) complexes. From the results in chapter 4, the XRD patterns exhibited good crystalline nature of CuS as a result of sharp and strong diffraction peaks obtained. There are eight peaks of 2θ angle between 26° and 79° relating to orthorhombic structure of SnS. While PbS has a cubic structure with polycrystalline nature, PbS/HDA and PbS both correspond to their crystalline planes of (200), (111), (220), (311), (222), (400), (331), (420) and (422) affirming to PbS QDs structure. SnS/HDA and SnS photosensitizers displayed eleven peaks between the values of 27.02° to 66.05° for SnS/HDA and 26.03° to 66.04° for SnS, in confirming the orthorhombic structure. SEM analysis revealed hexagonal structure for CuS, while PbS and SnS exhibited mesoporous nanostructures with spherical nanoparticles. HRTEM images indicated spherical nano-particles with particle sizes in the range of 3.14 - 44.39 nm. The outcome of HRTEM analysis revealed crystallite sizes varying as 10.90 – 11.57 nm, 3.14 – 5.95 nm and 14.96 – 44.39 nm for the CuS, PbS and SnS, originated from the primary ligands. HRTEM images originating from the Bis(N-1,4-Phenyl-N-Morhpo-dithiocarbamato bis(Mo/1,4-PHDTC) complexes indicated spherical nano-particles with particle sizes of 3.14 - 44.39 nm. Raman images in chapter 5 revealed the presence of Raman active modes of E2g 66 cm-1 and 304, cm-1 and E1g 627 cm-1 and 706 cm-1 for CuS, the active modes of TO 65 cm-1 and 2LO 626 cm-1 for PbS, active modes of B1g 69 cm-1 for SnS and 266 cm-1 for Ag. From the AFM results in chapter 5, CuS photosensitizer displayed a smooth surface and particle estimated to be 0.50 μm and height profile of 12percent. The PbS photosensitizer exhibited particle size of 1.82 μm and 0.654 μm for PbS/HDA, depicting a regular crystal growth rate. The size distribution of SnS nanoparticle at 357 nm connotes smooth surface and good compactness on the substrate. However, SnS/HDA at 122 nm displayed shape and size of non-symmetrical particles. AFM analysis in chapter 8 revealed good size roughness for CuS film. PbS exhibited particle size of 365 nm and size height of 18percent as the smoothest film, while PbS/HDA revealed 1.22 um size with 9percent size height. The evaluated particle sizes varied as 0.11- 1.18 um for SnS/HDA and 0.054 – 0.54 um for SnS films grown at 360 ℃ with size height of 16.8 and 8.4percent. The I-V efficiency obtained indicated that the CuS exhibited a much better efficiency in the QDSCs with higher Voc and the highest η being 2.85percent compared to CuS/HDA and Cu(II). High JSC of 11 mA/cm has been observed in the PbS/HDA QDSSCs, compared to the PbS and Pb(II) cells. The SnS/HDA exhibited a better performance compared to SnS and Sn(II) sensitizers due to the presence of HDA capping agent. , Thesis (MSc -- Faculty of Science and Agriculture, 2020
- Full Text:
- Date Issued: 2020-01
- Authors: Adedoyin Mojeed Agoro https://orcid.org/0000-0002-0434-9635
- Date: 2020-01
- Subjects: Nanostructured materials , Sulfur compounds
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/21523 , vital:48857
- Description: The work in this thesis describes synthesis, characterization and integration of nanostructured metal sulfides into titanium (IV) oxide for high performance dye sensitized solar cell. The synthesised single source precursors were evaluated using TGA, FTIR, , UV-Vis, PL,1H and 13CNMR, SEM, EDS, HRTEM, XRD, AFM, Raman, I-V, CV, Bode plot and EIS. TGA revealed the thermal degradation and quantified the mass percentage of metal sulphides as 33percent, 45percent and 27percent for CuS, PbS and SnS nanoparticles, respectively. FTIR analysis showed bands at 1580-1450 cm-1, and 1060-940 cm-1 tentatively assigned to C-N and C-S stretching frequencies correspondingly. The (M-S) stretching was observed at 577-406 cm-1 for the complexes using bis(N-di-isopropyl-N-octyldithiocarbamato) as primary ligands. IR spectra of bis(N-1,4-phenyl-N-(4-morpholinedithiocarbamato) as secondary ligands suggested the presence of (C-N) vibrations at 1508-1513 cm-1 for the complexes and 1507-1584 cm-1 for the ligands. The bands in the region of 973-1030 cm-1 were assigned to the complexes and 974- 983 cm-1 were attributed to the ligands, whereas vibration frequencies at 416-625 cm-1 were Nelson's Choice were included in these preliminary variety trials (PVTs) as checks. Twenty-five hybrids expressing high values for the Smith – Hazel selection index were identified across sites over years. Among those hybrids were two checks, namely Q16 (PAN5Q649R) and Q33 (Phb31MO7BR). The top five high – yielding hybrids selected based on the selection index were considered to be the most productive, stable and adaptable based on the GGE biplot and AMMI stability values. None of these single cross hybrids over yielded the best hybrid check (Q16) in the current study. A high potential environment, Centane, was the ideal environments for evaluating genotypes in the present study. The studies showed inbred lines L22, L23, L26, L28, L25, L29 and L31 to be low N stress tolerant at 0 kg N ha-1 based on the low N stress tolerance indices under glasshouse and the field conditions; they were also among the top ten grain-yielders under field conditions at 0 kg N ha-1. Also, in the NUE study, they were found to be among the top ten most N-efficient inbred lines under low N soils, under 30 kg N ha-1, and were among the top twenty-four inbred lines with high NUE values across the N levels in the study. Inbred lines L29 and L22 also produced testcross hybrids that were among the top twenty based on GY under 0 kg N ha-1. The testcross hybrids produced from these inbred lines were also among the top twenty-five with outstanding SCA effects for GY. These inbred lines were also parental lines of some of the top twenty- five best hybrids selected based on the Smith – Hazel selection index in the PVT study. Inbred lines L22, L23, L26, L28, L25, L29 and L31 can therefore further be evaluated and used as sources of N-tolerance genes in QPM breeding programs. tentatively assigned to M-S bond in the complexes. UV-Vis spectroscopy analysis for the complexes and from primary and secondary ligands are between within the range of 338 – 340 nm. PL studies of the primary ligands with metal complexes indicated emissions at 464 nm, 462 nm, 462 nm for Pb(II) and Sn(II), and Cu(II). The presence of secondary ligands was revealed by the absorption peaks at 455, 456 and 457 nm, exhibiting both the signals and chemical constituents of the respective ligands and their corresponding complexes. The electrochemistry in chapters 3 and 4 reveals that phase angle in the Bode plots changes with frequencies for Sn(II) complexes at 58, 57 and 8 respectively. Bode plots showed remarkable electronics of Cu(II) and Pb(II) complex interfaces. The CV curves exhibit two kinds of redox peaks indicating reduction at the negative potentials and oxidation at the positive potentials. The EIS, electrodes produced Rct for Pb(II), Cu(II) and Sn(II) electrodes in chapter 3. Moreover The EIS revealed that Sn(II) sensitizer displaced a stronger chemical capacitance and improved efficiency which could lead to better electron lifetime yield. The obtained CV exhibited anodic and cathodic peaks for Pb(II), connoting a reduction in Pb2+ and oxidation in Pb2-. Bode plot phase angle displayed Sn(II) and Pb(II) with maxima phase, indicating the presence of time constants of the electrode processes in Bis(N-1,4-Phenyl-N-Morhpo-dithiocarbamato bis(Mo/1,4-PHDTC) complexes. From the results in chapter 4, the XRD patterns exhibited good crystalline nature of CuS as a result of sharp and strong diffraction peaks obtained. There are eight peaks of 2θ angle between 26° and 79° relating to orthorhombic structure of SnS. While PbS has a cubic structure with polycrystalline nature, PbS/HDA and PbS both correspond to their crystalline planes of (200), (111), (220), (311), (222), (400), (331), (420) and (422) affirming to PbS QDs structure. SnS/HDA and SnS photosensitizers displayed eleven peaks between the values of 27.02° to 66.05° for SnS/HDA and 26.03° to 66.04° for SnS, in confirming the orthorhombic structure. SEM analysis revealed hexagonal structure for CuS, while PbS and SnS exhibited mesoporous nanostructures with spherical nanoparticles. HRTEM images indicated spherical nano-particles with particle sizes in the range of 3.14 - 44.39 nm. The outcome of HRTEM analysis revealed crystallite sizes varying as 10.90 – 11.57 nm, 3.14 – 5.95 nm and 14.96 – 44.39 nm for the CuS, PbS and SnS, originated from the primary ligands. HRTEM images originating from the Bis(N-1,4-Phenyl-N-Morhpo-dithiocarbamato bis(Mo/1,4-PHDTC) complexes indicated spherical nano-particles with particle sizes of 3.14 - 44.39 nm. Raman images in chapter 5 revealed the presence of Raman active modes of E2g 66 cm-1 and 304, cm-1 and E1g 627 cm-1 and 706 cm-1 for CuS, the active modes of TO 65 cm-1 and 2LO 626 cm-1 for PbS, active modes of B1g 69 cm-1 for SnS and 266 cm-1 for Ag. From the AFM results in chapter 5, CuS photosensitizer displayed a smooth surface and particle estimated to be 0.50 μm and height profile of 12percent. The PbS photosensitizer exhibited particle size of 1.82 μm and 0.654 μm for PbS/HDA, depicting a regular crystal growth rate. The size distribution of SnS nanoparticle at 357 nm connotes smooth surface and good compactness on the substrate. However, SnS/HDA at 122 nm displayed shape and size of non-symmetrical particles. AFM analysis in chapter 8 revealed good size roughness for CuS film. PbS exhibited particle size of 365 nm and size height of 18percent as the smoothest film, while PbS/HDA revealed 1.22 um size with 9percent size height. The evaluated particle sizes varied as 0.11- 1.18 um for SnS/HDA and 0.054 – 0.54 um for SnS films grown at 360 ℃ with size height of 16.8 and 8.4percent. The I-V efficiency obtained indicated that the CuS exhibited a much better efficiency in the QDSCs with higher Voc and the highest η being 2.85percent compared to CuS/HDA and Cu(II). High JSC of 11 mA/cm has been observed in the PbS/HDA QDSSCs, compared to the PbS and Pb(II) cells. The SnS/HDA exhibited a better performance compared to SnS and Sn(II) sensitizers due to the presence of HDA capping agent. , Thesis (MSc -- Faculty of Science and Agriculture, 2020
- Full Text:
- Date Issued: 2020-01
Synthesis of bioethanol from lignocellulosic materials: A focus on grass and waste paper as raw materials
- Authors: Vala, Mavula Kikwe
- Date: 2009-12
- Subjects: Ethanol as fuel , Biomass energy , Lignocellulose -- Biotechnology
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/24499 , vital:63049
- Description: Biofuels are currently recognized as not only a necessity, but an inevitable pathway to secure the planet future energy needs. Food crops have been used (so far) as the biomass for bioethanol and biodiesel production. This has increased concerns over food security and led to the search for diversification and alternative feedstocks for biofuel production. The use of lignocellulosic materials, the most abundant, low cost and easy feedstock to harvest for bioethanol purpose, involves challenging production processes. Several approaches have been used to facilitate the breakdown of the biopolymer structure to produce fermentable sugars that can be converted to ethanol. Most of the approaches have used high temperatures and pressures and have often led to the production of inhibitors of fermentation. In this study, lignocellulosic materials from grass and newsprint were investigated as sources of biomass for bioethanol production using a chemical route (sulfuric acid hydrolysis) which made use of temperatures below 100°C at normal atmospheric pressure. Fermentation of toxic lignocellulosic hydrolyzates was possible after the development of a method for inhibitors removal. The method used treated wood chips as a stationary phase in a chromatographic column to remove inhibitors. This method is expected to be extended to applications such as in municipal wastewater treatment. Sugar yields of 22.26 and 8.9 g/L of hydrolyzate; and an ethanol yield of 184.5 and 130.4 mg/mL of must were achieved for 5g grass and newsprint respectively using optimum conditions of 2percent H2SO4 at 97.5°C for grass and 0.5percent H2SO4 at 97.5°C for newsprint during the hydrolysis process. Pure cellulose was used as a control for the biomass where 254.1 g/L of fermentable sugars were recovered from soluble cellulose and the yield of ethanol was 201.8 mg/mL. , Thesis (MSc) -- Faculty of Science and Agriculture, 2009
- Full Text:
- Date Issued: 2009-12
- Authors: Vala, Mavula Kikwe
- Date: 2009-12
- Subjects: Ethanol as fuel , Biomass energy , Lignocellulose -- Biotechnology
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/24499 , vital:63049
- Description: Biofuels are currently recognized as not only a necessity, but an inevitable pathway to secure the planet future energy needs. Food crops have been used (so far) as the biomass for bioethanol and biodiesel production. This has increased concerns over food security and led to the search for diversification and alternative feedstocks for biofuel production. The use of lignocellulosic materials, the most abundant, low cost and easy feedstock to harvest for bioethanol purpose, involves challenging production processes. Several approaches have been used to facilitate the breakdown of the biopolymer structure to produce fermentable sugars that can be converted to ethanol. Most of the approaches have used high temperatures and pressures and have often led to the production of inhibitors of fermentation. In this study, lignocellulosic materials from grass and newsprint were investigated as sources of biomass for bioethanol production using a chemical route (sulfuric acid hydrolysis) which made use of temperatures below 100°C at normal atmospheric pressure. Fermentation of toxic lignocellulosic hydrolyzates was possible after the development of a method for inhibitors removal. The method used treated wood chips as a stationary phase in a chromatographic column to remove inhibitors. This method is expected to be extended to applications such as in municipal wastewater treatment. Sugar yields of 22.26 and 8.9 g/L of hydrolyzate; and an ethanol yield of 184.5 and 130.4 mg/mL of must were achieved for 5g grass and newsprint respectively using optimum conditions of 2percent H2SO4 at 97.5°C for grass and 0.5percent H2SO4 at 97.5°C for newsprint during the hydrolysis process. Pure cellulose was used as a control for the biomass where 254.1 g/L of fermentable sugars were recovered from soluble cellulose and the yield of ethanol was 201.8 mg/mL. , Thesis (MSc) -- Faculty of Science and Agriculture, 2009
- Full Text:
- Date Issued: 2009-12
Characterization of bioflocculants produced by consortia of three marine bacteria belonging to the genera bacillus and cobetia previously isolated from the bottom sediment of Algoa Bay in the Eastern Cape Province of South Africa
- Ugbenyen, Anthony Moses https://orcid.org/0000-0002-1381-3428
- Authors: Ugbenyen, Anthony Moses https://orcid.org/0000-0002-1381-3428
- Date: 2013
- Subjects: Water -- Purification -- Flocculation , Water quality management , Flocculation
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/24454 , vital:62804
- Description: The bioflocculant-producing potentials of three marine bacteria isolated from the sediment samples of Algoa Bay in the Eastern Cape Province of South Africa were assessed. Analysis of the partial nucleotide sequence of the 16S rDNA of the bacteria revealed 99 percent, 99 percent, and 98 percent similarity to Cobetia sp. L222, Bacillus sp. A-5A, and Bacillus sp. HXG-C1 respectively and the sequence was deposited in GenBank as Cobetia sp. OAUIFE, Bacillus sp. MAYA and Bacillus sp. Gilbert (accession number JF799092, JF799093, and HQ537128 respectively). Cultivation condition studies for Cobetia sp. OAUIFE revealed that bioflocculant production was optimal with an inoculum size of 2 percent (v/v), initial pH of 6.0, Mn2+ as the metal ion, and glucose as the carbon source. Metal ions, including Na+, K+, Li+, Ca2+and Mg2+ stimulated bioflocculant production resulting in flocculating activity of above 90 percent. This crude bioflocculant is thermally stable, with about 78 percent of its flocculating activity remaining after heating at 100 oC for 25 min. Analysis of the purified bioflocculant revealed it to be an acidic extracellular polysaccharide. FTIR analysis revealed the presence of methoxyl, hydroxyl, and carboxyl - groups in the compound bioflocculant and SEM micrograph of the bioflocculant revealed a crystal-linear structure. On the other hand, bioflocculant production by Bacillus sp. MAYA was optimal when glucose (95.6 percent flocculating activity) and ammonium nitrate (83.3 percent flocculating activity) were used as carbon and nitrogen sources respectively; inoculum size was 2 percent (v/v); initial pH 6; and Ca2+ as coagulant aid. Chemical analysis of the purified bioflocculant shows that it is composed of uronic acid, neutral sugar and protein. FTIR analysis also revealed the presence of methoxyl, hydroxyl, carboxyl and amino- groups in this bioflocculant. The bioflocculant is thermostable with about 65.6 percent residual flocculating activity retained after heating the bioflocculant at 100 oC for 25 min. However bioflocculant production by Bacillus sp. Gilbert was optimal when sodium carbonate (95.2 percent flocculating activity) and potassium nitrate (76.6 percent flocculating activity) were used as carbon and nitrogen sources respectively; inoculum size was 3 percent (v/v); initial pH 9; and Al3+ as cation. The crude bioflocculant retained 44.2 percent residual flocculating activity after heating at 100 oC for 15 min. FTIR analysis reveals the presence of hydroxyl, carboxyl and methylene - groups in the compound bioflocculant. SEM micrograph of the bioflocculant revealed an amorphous compound. The consortia of these bacteria strains also produced bioflocculants with high flocculating activities which were highly efficient in removing turbidity and chemical oxygen demand (COD) from brewery wastewater, diary wastewater and river water. The bioflocculants from the consortia seemed better than traditional flocculants such as alum . The characteristics of the bioflocculant produced by the consortium of Cobetia sp. OAUIFE and Bacillus sp. MAYA showed that this extracellular bioflocculant, composed of 66percent uronic acid and 31percent protein and an optimum flocculation (90 percent) of kaolin suspension, when the dosage concentration was 0.8 mg/ml, under weak alkaline pH of 8, and Ca2+ as a coagulant aid. The bioflocculant is thermally stable, with a high residual flocculating activity of 86.7 percent, 89.3 percent and 87.0 percent after heating at 50 oC, 80 oC and 100 oC for 25 min respectively. The FTIR analysis of the bioflocculant indicated the presence of hydroxyl, amino, carbonyl and carboxyl functional groups. Scanning electron microscopy (SEM) image revealed a crystal-linear spongy-like bioflocculant structure and EDX analysis of the purified bioflocculant showed that the elemental composition in mass proportion of C,N,O,S and P was 6.67:6.23:37.55:0.38:4.42 (percent w/w). However, the characteristics of the bioflocculant produced by the consortium of Cobetia sp OAUIFE and Bacillus sp. Gilbert showed an optimum flocculation (90 percent) of kaolin suspension when the dosage concentration was 0.2 mg/ml, under neutral pH of 7, and Ca2+ as a coagulant aid. The FTIR analysis of the bioflocculant indicated the presence of hydroxyl and carbonyl functional groups. Scanning electron microscopy (SEM) image revealed an amorphous morphology. On the other hand the bioflocculant produced by the consortium of Bacillus sp. MAYA and Bacillus sp. Gilbert showed similar characteristic with the bioflocculant from the consortium of Cobetia sp. OAUIFE and Bacillus sp. Gilbert except for Al3+ being the preferred coagulant aid. The characteristics of the bioflocculant produced by the consortium of Cobetia sp. OAUIFE, Bacillus sp. MAYA and Bacillus sp. Gilbert showed an optimum flocculation (87 percent) of kaolin suspension when the dosage concentration was 1.0 mg/ml. Under strong alkaline pH of 12, flocculating activity reached (95 percent) when Al3+ was the coagulant aid. The FTIR analysis of the bioflocculant indicated the presence of hydroxyl, amino, carbonyl and carboxyl and phosphoryl functional groups. Scanning electron microscopy (SEM) image revealed a flaky amorphous morphological structure. Due to the excellent COD and turbidity removal efficiencies of the bioflocculants produced by the consortia, these make those attractive candidates for use in water and wastewater treatment. , Thesis (PhD) -- Faculty of Science and Agriculture, 2013
- Full Text:
- Date Issued: 2013
- Authors: Ugbenyen, Anthony Moses https://orcid.org/0000-0002-1381-3428
- Date: 2013
- Subjects: Water -- Purification -- Flocculation , Water quality management , Flocculation
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/24454 , vital:62804
- Description: The bioflocculant-producing potentials of three marine bacteria isolated from the sediment samples of Algoa Bay in the Eastern Cape Province of South Africa were assessed. Analysis of the partial nucleotide sequence of the 16S rDNA of the bacteria revealed 99 percent, 99 percent, and 98 percent similarity to Cobetia sp. L222, Bacillus sp. A-5A, and Bacillus sp. HXG-C1 respectively and the sequence was deposited in GenBank as Cobetia sp. OAUIFE, Bacillus sp. MAYA and Bacillus sp. Gilbert (accession number JF799092, JF799093, and HQ537128 respectively). Cultivation condition studies for Cobetia sp. OAUIFE revealed that bioflocculant production was optimal with an inoculum size of 2 percent (v/v), initial pH of 6.0, Mn2+ as the metal ion, and glucose as the carbon source. Metal ions, including Na+, K+, Li+, Ca2+and Mg2+ stimulated bioflocculant production resulting in flocculating activity of above 90 percent. This crude bioflocculant is thermally stable, with about 78 percent of its flocculating activity remaining after heating at 100 oC for 25 min. Analysis of the purified bioflocculant revealed it to be an acidic extracellular polysaccharide. FTIR analysis revealed the presence of methoxyl, hydroxyl, and carboxyl - groups in the compound bioflocculant and SEM micrograph of the bioflocculant revealed a crystal-linear structure. On the other hand, bioflocculant production by Bacillus sp. MAYA was optimal when glucose (95.6 percent flocculating activity) and ammonium nitrate (83.3 percent flocculating activity) were used as carbon and nitrogen sources respectively; inoculum size was 2 percent (v/v); initial pH 6; and Ca2+ as coagulant aid. Chemical analysis of the purified bioflocculant shows that it is composed of uronic acid, neutral sugar and protein. FTIR analysis also revealed the presence of methoxyl, hydroxyl, carboxyl and amino- groups in this bioflocculant. The bioflocculant is thermostable with about 65.6 percent residual flocculating activity retained after heating the bioflocculant at 100 oC for 25 min. However bioflocculant production by Bacillus sp. Gilbert was optimal when sodium carbonate (95.2 percent flocculating activity) and potassium nitrate (76.6 percent flocculating activity) were used as carbon and nitrogen sources respectively; inoculum size was 3 percent (v/v); initial pH 9; and Al3+ as cation. The crude bioflocculant retained 44.2 percent residual flocculating activity after heating at 100 oC for 15 min. FTIR analysis reveals the presence of hydroxyl, carboxyl and methylene - groups in the compound bioflocculant. SEM micrograph of the bioflocculant revealed an amorphous compound. The consortia of these bacteria strains also produced bioflocculants with high flocculating activities which were highly efficient in removing turbidity and chemical oxygen demand (COD) from brewery wastewater, diary wastewater and river water. The bioflocculants from the consortia seemed better than traditional flocculants such as alum . The characteristics of the bioflocculant produced by the consortium of Cobetia sp. OAUIFE and Bacillus sp. MAYA showed that this extracellular bioflocculant, composed of 66percent uronic acid and 31percent protein and an optimum flocculation (90 percent) of kaolin suspension, when the dosage concentration was 0.8 mg/ml, under weak alkaline pH of 8, and Ca2+ as a coagulant aid. The bioflocculant is thermally stable, with a high residual flocculating activity of 86.7 percent, 89.3 percent and 87.0 percent after heating at 50 oC, 80 oC and 100 oC for 25 min respectively. The FTIR analysis of the bioflocculant indicated the presence of hydroxyl, amino, carbonyl and carboxyl functional groups. Scanning electron microscopy (SEM) image revealed a crystal-linear spongy-like bioflocculant structure and EDX analysis of the purified bioflocculant showed that the elemental composition in mass proportion of C,N,O,S and P was 6.67:6.23:37.55:0.38:4.42 (percent w/w). However, the characteristics of the bioflocculant produced by the consortium of Cobetia sp OAUIFE and Bacillus sp. Gilbert showed an optimum flocculation (90 percent) of kaolin suspension when the dosage concentration was 0.2 mg/ml, under neutral pH of 7, and Ca2+ as a coagulant aid. The FTIR analysis of the bioflocculant indicated the presence of hydroxyl and carbonyl functional groups. Scanning electron microscopy (SEM) image revealed an amorphous morphology. On the other hand the bioflocculant produced by the consortium of Bacillus sp. MAYA and Bacillus sp. Gilbert showed similar characteristic with the bioflocculant from the consortium of Cobetia sp. OAUIFE and Bacillus sp. Gilbert except for Al3+ being the preferred coagulant aid. The characteristics of the bioflocculant produced by the consortium of Cobetia sp. OAUIFE, Bacillus sp. MAYA and Bacillus sp. Gilbert showed an optimum flocculation (87 percent) of kaolin suspension when the dosage concentration was 1.0 mg/ml. Under strong alkaline pH of 12, flocculating activity reached (95 percent) when Al3+ was the coagulant aid. The FTIR analysis of the bioflocculant indicated the presence of hydroxyl, amino, carbonyl and carboxyl and phosphoryl functional groups. Scanning electron microscopy (SEM) image revealed a flaky amorphous morphological structure. Due to the excellent COD and turbidity removal efficiencies of the bioflocculants produced by the consortia, these make those attractive candidates for use in water and wastewater treatment. , Thesis (PhD) -- Faculty of Science and Agriculture, 2013
- Full Text:
- Date Issued: 2013
Barriers and reasons for exercise of rural and urban overweight and obese populations in Buffalo City Metropolitan Municipality, Eastern Cape
- Authors: Mrwebi, Thembani
- Date: 2021-04
- Subjects: Obesity--Prevention , Public health--Exercise
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22522 , vital:52388
- Description: It is documented that obesity is highly prevalent across rural and urban groups in industrialised and underdeveloped countries. This problem is an alarming issue as community members remain unsure about avoiding risking their health. Various health surveys reveal that obesity has increased among communities in the Buffalo City Metro Municipality in the Eastern Cape, and it has consequently made communities vulnerable to non-communicable diseases. The researcher explored factors and barriers of exercise for rural and urban obese populations in Buffalo City Metropolitan Municipality, Eastern Cape. This study was descriptive and explorative, utilising a questionnaire for gathering information. A purposive sample of 80 members from the two selected communities completed the questionnaire. A factor analysis was performed to identify factors that motivate physical activity and barriers to physical activity. It was discovered that all evaluated members were fully aware of the harmful repercussions of being overweight or obese. Nevertheless, only a tiny percentage of those who took part in the study decided to live a healthier lifestyle because of their obesity. Constructive motivating factors included increasing their self-image, enhancing their wellbeing, and getting highly involved in active and regular exercise. Negative motivators included finding it challenging to fit into old clothes and the worry of developing obesity-related diseases. Respondents noted the following impediments in regular exercises and physical activities; African cultural values, limited operational hours of physical activity facilities, insufficient time, and a lack of enthusiasm. , Thesis (MPhil) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Mrwebi, Thembani
- Date: 2021-04
- Subjects: Obesity--Prevention , Public health--Exercise
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22522 , vital:52388
- Description: It is documented that obesity is highly prevalent across rural and urban groups in industrialised and underdeveloped countries. This problem is an alarming issue as community members remain unsure about avoiding risking their health. Various health surveys reveal that obesity has increased among communities in the Buffalo City Metro Municipality in the Eastern Cape, and it has consequently made communities vulnerable to non-communicable diseases. The researcher explored factors and barriers of exercise for rural and urban obese populations in Buffalo City Metropolitan Municipality, Eastern Cape. This study was descriptive and explorative, utilising a questionnaire for gathering information. A purposive sample of 80 members from the two selected communities completed the questionnaire. A factor analysis was performed to identify factors that motivate physical activity and barriers to physical activity. It was discovered that all evaluated members were fully aware of the harmful repercussions of being overweight or obese. Nevertheless, only a tiny percentage of those who took part in the study decided to live a healthier lifestyle because of their obesity. Constructive motivating factors included increasing their self-image, enhancing their wellbeing, and getting highly involved in active and regular exercise. Negative motivators included finding it challenging to fit into old clothes and the worry of developing obesity-related diseases. Respondents noted the following impediments in regular exercises and physical activities; African cultural values, limited operational hours of physical activity facilities, insufficient time, and a lack of enthusiasm. , Thesis (MPhil) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-04
Aspects of the ecology of the estuarine round-herring Gilchristella aestuaria (Pisces: Clupeidae) and its small-scale fishery potential
- Zvavahera, Munetsi https://orcid.org/0000-0002-5337-1943
- Authors: Zvavahera, Munetsi https://orcid.org/0000-0002-5337-1943
- Date: 2021-05
- Subjects: Small-scale fisheries , Silversides
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/22765 , vital:52752
- Description: In the past two decades, there has been increasing pressure for small-scale inland fisheries to play a central role in food and nutrient security for poor communities in South Africa. For decades, South African inland fisheries have focussed on the exploitation of large fish species and generally ignored the exploitation of inland small fish species (SFS). This research aimed to assess the ecology and small-scale fishery potential of the estuarine round-herring, Gilchristella aestuaria. To understand the ecology of G. aestuaria better, morphometric trait analysis and fish condition of populations in relation to environmental variables (salinity, pH, temperature, turbidity and chlorophyll-a) were done. Fish were supplemented with samples acquired from the SAIAB collection facility for 14 sites to cover all the three South African biogeographic regions, stretching from Lake Sibaya (KZN) to the Orange River estuary in the western parts of the country. The morphometric trait analysis showed that G. aestuaria populations can be distinguished based on the trait variation, however there were many overlaps for populations that are interconnected, with distant/ geographically separated populations showing clear differences. Morphometric traits of the G. aestuaria population were significantly different, however there was no strong directional relationship with environmental variables and variation in morphometric traits. However, fish condition as measured by Fulton’s condition (K) and relative weight (Wr) showed variation between populations found in different environments. These differences suggest that these populations must be managed differently if G. aestuaria is to be exploited in managed fisheries. To determine the potential nutrient value of G. aestuaria to the human diet, samples from two freshwater sites and five estuarine sites were analysed for essential macro and micronutrients. The nutrient content of G. aestuaria revealed there is potential for exploitation, as the species has a high macro (protein and fat) and micronutrient composition (calcium, iron and zinc). Mean ± SD of selected nutrients were protein (61.7±5.0 g/100g), fat (20.4±3.7g/ 100g), calcium (3507.5±314.0mg), iron (40.37±14.0mg/ 100g), zinc (22.47±5.6mg/ 100) and vitamin A (37.3±44.4 RAE/ 100g). The nutrient composition of fish collected from freshwater sites was comparable to those collected from estuarine environments. Using the recommended dietary allowances (RDA) from literature, the mass of fish and the number of fish that would provide a minimum amount for each nutrient were calculated. A child would require only 13.4g of dry G. aestuaria or approximately 74 dried fish to meet the daily requirements of zinc. Other minerals such as iron and calcium also showed a similar low weight or number of fish required to meet daily requirements for the different categories. A small number of G. aestuaria are needed to meet RDA for groups (children, adult men, adult women, pregnant women and lactating mothers). A comparison was done for the nutrient composition of G. aestuaria with reference species that are already harvested for human consumption in some African and Asian countries. The protein content of G. aestuaria was comparable to Chisense (Microthrissa moeruensis) and Kapenta Limnothrissa miodon), while the fat composition was more than twice Chisense and Kapenta. Comparing the mineral composition, G. aestuaria had more than three times higher calcium than Mola (Amblypharyngodon mola) and Puti (Puntius sophore). Zinc composition was four times higher than M. moeruensis and L. miodon. Further exploration of the ecology of G. aestuaria was studied using the Sundays River irrigations ponds as a case study that would represent small impoundments across South Africa. Species rank abundance curve and catch per unit effort (CPUE) on the Sundays Irrigation ponds revealed that G. aestuaria dominated numerically and biomass in the Sundays River irrigation ponds. To assess the potential of harvesting G. aestuaria harvesting experiments were conducted using depletion (removal) sampling. Catchweight (kg) ranged from 2.16 (1.03; 3.28) to 61.25 (44.40; 78.09) kg and the estimated biomass from the depletion model ranged from 1.05 to 40.19 kg/ha for September 2019. The depletion model revealed that small impoundments have high biomass per hectare of G. aestuaria ranging from which indicates that the species may not support a commercial fishery but small-scale fisheries. In conclusion, G. aestuaria could become a meaningful contribution to the food and nutrient security of poor communities where available as a food source through small-scale fishery exploitation. The extent of this contribution may depend on its production potential in various regions and environments. More research is however needed to determine the long-term sustainability of harvesting of G aestuaria by looking at how populations respond to harvesting. , Thesis (PhD) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-05
- Authors: Zvavahera, Munetsi https://orcid.org/0000-0002-5337-1943
- Date: 2021-05
- Subjects: Small-scale fisheries , Silversides
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/22765 , vital:52752
- Description: In the past two decades, there has been increasing pressure for small-scale inland fisheries to play a central role in food and nutrient security for poor communities in South Africa. For decades, South African inland fisheries have focussed on the exploitation of large fish species and generally ignored the exploitation of inland small fish species (SFS). This research aimed to assess the ecology and small-scale fishery potential of the estuarine round-herring, Gilchristella aestuaria. To understand the ecology of G. aestuaria better, morphometric trait analysis and fish condition of populations in relation to environmental variables (salinity, pH, temperature, turbidity and chlorophyll-a) were done. Fish were supplemented with samples acquired from the SAIAB collection facility for 14 sites to cover all the three South African biogeographic regions, stretching from Lake Sibaya (KZN) to the Orange River estuary in the western parts of the country. The morphometric trait analysis showed that G. aestuaria populations can be distinguished based on the trait variation, however there were many overlaps for populations that are interconnected, with distant/ geographically separated populations showing clear differences. Morphometric traits of the G. aestuaria population were significantly different, however there was no strong directional relationship with environmental variables and variation in morphometric traits. However, fish condition as measured by Fulton’s condition (K) and relative weight (Wr) showed variation between populations found in different environments. These differences suggest that these populations must be managed differently if G. aestuaria is to be exploited in managed fisheries. To determine the potential nutrient value of G. aestuaria to the human diet, samples from two freshwater sites and five estuarine sites were analysed for essential macro and micronutrients. The nutrient content of G. aestuaria revealed there is potential for exploitation, as the species has a high macro (protein and fat) and micronutrient composition (calcium, iron and zinc). Mean ± SD of selected nutrients were protein (61.7±5.0 g/100g), fat (20.4±3.7g/ 100g), calcium (3507.5±314.0mg), iron (40.37±14.0mg/ 100g), zinc (22.47±5.6mg/ 100) and vitamin A (37.3±44.4 RAE/ 100g). The nutrient composition of fish collected from freshwater sites was comparable to those collected from estuarine environments. Using the recommended dietary allowances (RDA) from literature, the mass of fish and the number of fish that would provide a minimum amount for each nutrient were calculated. A child would require only 13.4g of dry G. aestuaria or approximately 74 dried fish to meet the daily requirements of zinc. Other minerals such as iron and calcium also showed a similar low weight or number of fish required to meet daily requirements for the different categories. A small number of G. aestuaria are needed to meet RDA for groups (children, adult men, adult women, pregnant women and lactating mothers). A comparison was done for the nutrient composition of G. aestuaria with reference species that are already harvested for human consumption in some African and Asian countries. The protein content of G. aestuaria was comparable to Chisense (Microthrissa moeruensis) and Kapenta Limnothrissa miodon), while the fat composition was more than twice Chisense and Kapenta. Comparing the mineral composition, G. aestuaria had more than three times higher calcium than Mola (Amblypharyngodon mola) and Puti (Puntius sophore). Zinc composition was four times higher than M. moeruensis and L. miodon. Further exploration of the ecology of G. aestuaria was studied using the Sundays River irrigations ponds as a case study that would represent small impoundments across South Africa. Species rank abundance curve and catch per unit effort (CPUE) on the Sundays Irrigation ponds revealed that G. aestuaria dominated numerically and biomass in the Sundays River irrigation ponds. To assess the potential of harvesting G. aestuaria harvesting experiments were conducted using depletion (removal) sampling. Catchweight (kg) ranged from 2.16 (1.03; 3.28) to 61.25 (44.40; 78.09) kg and the estimated biomass from the depletion model ranged from 1.05 to 40.19 kg/ha for September 2019. The depletion model revealed that small impoundments have high biomass per hectare of G. aestuaria ranging from which indicates that the species may not support a commercial fishery but small-scale fisheries. In conclusion, G. aestuaria could become a meaningful contribution to the food and nutrient security of poor communities where available as a food source through small-scale fishery exploitation. The extent of this contribution may depend on its production potential in various regions and environments. More research is however needed to determine the long-term sustainability of harvesting of G aestuaria by looking at how populations respond to harvesting. , Thesis (PhD) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-05
Effect of Mucuna pruriens based-diets on fatty acids composition and sensory attributes of meat from broiler chickens
- Authors: Makhamba, Nasiphi
- Date: 2020-11
- Subjects: Fatty acids , Broilers (Chickens)
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20771 , vital:46554
- Description: The current study was conducted to determine the effect of feeding different inclusion levels of processed Mucuna pruriens on fatty acid composition and sensory attributes of broiler chickens. 120 Cob500 broilers were used in the experiment. The experiment was divided into 4 treatment (0, 10, 15 and 20 percent of Mucuna pruriens) groups, each treatment with 6 replicates (5 birds per replicate) in a completely randomized design. The first treatment (0 percent) was used as control against the three different levels of Mucuna pruriens. The birds were reared in a deep litter system until they reached slaughter weight of 2kg. At day 42 a total of 80 birds were slaughtered and breast muscles were sampled for the evaluation of sensory attributes and fatty acid composition. For sensory evaluation meat samples were prepared and boiled at 80°C until the internal temperature reached 82°C, 40 consumers were used to assess the meat samples and give scores according to 9-point hedonic scale. The fatty acid content was determined and recorded using the gas chromatography. Total saturated fatty acid (SFA), total monounsaturated fatty acid (MUFA), and total polyunsaturated fatty acid (PUFA) of the breast meat were not affected by diets. Omega-6 and omega-3 fatty acid were also not influenced by treatment diets. However, breast muscle from broilers fed 20 percent Mucuna pruriens seed meal inclusion had lower Myristic acid. The sensory attributes; aroma, colour, flavour, juiciness, tenderness and acceptability were assessed, dietary treatments affected the juiciness, tenderness and acceptability of meat, the treatments showed no significant difference on colour, aroma and flavour. Different age groups accepted the meat differently, the respondents that were between 18 and 22 years old gave the highest scores to the acceptability of meat than the other age groups, and different age groups also gave different scores in the aroma of meat. Females and males accepted the meat differently, the female respondents gave higher scores on the flavour of meat than males. Different inclusion levels of Mucuna pruriens positively affected fatty acid composition and sensory attributes of broiler chickens without causing any detrimental effects. , Thesis (MSc) (Animal Science) -- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2020-11
- Authors: Makhamba, Nasiphi
- Date: 2020-11
- Subjects: Fatty acids , Broilers (Chickens)
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20771 , vital:46554
- Description: The current study was conducted to determine the effect of feeding different inclusion levels of processed Mucuna pruriens on fatty acid composition and sensory attributes of broiler chickens. 120 Cob500 broilers were used in the experiment. The experiment was divided into 4 treatment (0, 10, 15 and 20 percent of Mucuna pruriens) groups, each treatment with 6 replicates (5 birds per replicate) in a completely randomized design. The first treatment (0 percent) was used as control against the three different levels of Mucuna pruriens. The birds were reared in a deep litter system until they reached slaughter weight of 2kg. At day 42 a total of 80 birds were slaughtered and breast muscles were sampled for the evaluation of sensory attributes and fatty acid composition. For sensory evaluation meat samples were prepared and boiled at 80°C until the internal temperature reached 82°C, 40 consumers were used to assess the meat samples and give scores according to 9-point hedonic scale. The fatty acid content was determined and recorded using the gas chromatography. Total saturated fatty acid (SFA), total monounsaturated fatty acid (MUFA), and total polyunsaturated fatty acid (PUFA) of the breast meat were not affected by diets. Omega-6 and omega-3 fatty acid were also not influenced by treatment diets. However, breast muscle from broilers fed 20 percent Mucuna pruriens seed meal inclusion had lower Myristic acid. The sensory attributes; aroma, colour, flavour, juiciness, tenderness and acceptability were assessed, dietary treatments affected the juiciness, tenderness and acceptability of meat, the treatments showed no significant difference on colour, aroma and flavour. Different age groups accepted the meat differently, the respondents that were between 18 and 22 years old gave the highest scores to the acceptability of meat than the other age groups, and different age groups also gave different scores in the aroma of meat. Females and males accepted the meat differently, the female respondents gave higher scores on the flavour of meat than males. Different inclusion levels of Mucuna pruriens positively affected fatty acid composition and sensory attributes of broiler chickens without causing any detrimental effects. , Thesis (MSc) (Animal Science) -- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2020-11
Adolescent sexual reproductive health and rights in the Alice area, Eastern Cape Province of South Africa
- Authors: Moko, Zukhanye
- Date: 2021-02
- Subjects: Reproductive health , Right to health , HIV infections
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20676 , vital:46423
- Description: Sexual Reproductive Health (SRH) is a significant aspect of adolescent’s growth. Adolescents particularly girls face the risk of exposure to Human Immunodeficiency Virus (HIV), Sexually Transmitted Diseases (STDs), child marriages, high rates of unwanted pregnancy and the risk of those pregnancies can lead to unsafe abortion. In South Africa, considerable progress has been made in achieving improved access to Sexual Reproductive Health and Rights (SRHR) among the general population, however, some factors influencing SRHR of adolescents and young people have been slow to achieve. The study aims to investigate factors influencing Sexual Reproductive Health and Rights of adolescents in Alice, which is located in the Eastern Cape Province of South Africa. The Social-Ecological Model was considered appropriate for this study as it provides a comprehensive understanding of the multiple and interacting determinants of Sexual Reproductive Health and Rights. A qualitative methodology was adopted, involving focus groups with high school learners, in-depth interviews with institutional actors (Department of Health, Basic Education and Social Development), and participant observations. The study reveals that adolescents’ have access to Sexual Reproductive Health services from healthcare centres but only a few utilize or access them due to barriers such as the geographical location, denial and judgement about young people's sexuality limits their access to comprehensive knowledge to protect and promote their Sexual and Reproductive Health. The findings show that the adolescents who were most affected by Sexual Reproductive Health and Rights challenges were those from deep rural areas. They had minimal information/education compared to those residing in areas close to the town of Alice and major roads. Multi-sectoral interventions empowering adolescents and young people to exercise their rights to optimize SRHR service yield better results. , Thesis (MSc) -- Faculty of Science & Agriculture, 2021
- Full Text:
- Date Issued: 2021-02
- Authors: Moko, Zukhanye
- Date: 2021-02
- Subjects: Reproductive health , Right to health , HIV infections
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20676 , vital:46423
- Description: Sexual Reproductive Health (SRH) is a significant aspect of adolescent’s growth. Adolescents particularly girls face the risk of exposure to Human Immunodeficiency Virus (HIV), Sexually Transmitted Diseases (STDs), child marriages, high rates of unwanted pregnancy and the risk of those pregnancies can lead to unsafe abortion. In South Africa, considerable progress has been made in achieving improved access to Sexual Reproductive Health and Rights (SRHR) among the general population, however, some factors influencing SRHR of adolescents and young people have been slow to achieve. The study aims to investigate factors influencing Sexual Reproductive Health and Rights of adolescents in Alice, which is located in the Eastern Cape Province of South Africa. The Social-Ecological Model was considered appropriate for this study as it provides a comprehensive understanding of the multiple and interacting determinants of Sexual Reproductive Health and Rights. A qualitative methodology was adopted, involving focus groups with high school learners, in-depth interviews with institutional actors (Department of Health, Basic Education and Social Development), and participant observations. The study reveals that adolescents’ have access to Sexual Reproductive Health services from healthcare centres but only a few utilize or access them due to barriers such as the geographical location, denial and judgement about young people's sexuality limits their access to comprehensive knowledge to protect and promote their Sexual and Reproductive Health. The findings show that the adolescents who were most affected by Sexual Reproductive Health and Rights challenges were those from deep rural areas. They had minimal information/education compared to those residing in areas close to the town of Alice and major roads. Multi-sectoral interventions empowering adolescents and young people to exercise their rights to optimize SRHR service yield better results. , Thesis (MSc) -- Faculty of Science & Agriculture, 2021
- Full Text:
- Date Issued: 2021-02
Agro-morphological characterization and investigations into the response of yellow Quality Protein Maize (QPM) genotypes to low soil pH
- Authors: Bobotyana, Simthandile
- Date: 2021-04
- Subjects: Corn as food , Plants--Drought tolerance
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20528 , vital:46087
- Description: Maize (Zea mays L) is an essential food grain crop in South Africa and is mainly grown under rainfed conditions by small-scale farmers. Quality Protein Maize (QPM) contains a higher level of two essential amino acids, tryptophan, and lysine when equated to normal maize. Therefore, the QPM in communities is a vital cereal where maize is a staple crop. Among the significant abiotic stresses that adversely affect maize productivity, such as soil fertility. Low soil pH or soil acidity results in nutrient deficiencies, as well as the toxicity of minerals such as manganese (Mn), aluminium (Al), and iron (Fe). The objectives of the study were to: (1) Characterize yellow QPM inbred lines and testcross hybrids for agro-morphological variability under optimum conditions, (2) Determine the response of QPM inbred lines and testcross hybrids to Al toxicity, and (3) Estimate the combining ability of QPM genotypes for the tolerance to Al toxicity. The laboratory assessment for tolerance to Al toxicity revealed a negative relationship between relative root growth RRG and hematoxylin staining; among the inbred lines, the genotype 8Y, 17Y, and 7Y had the highest RRG and net root growth (NRG) values and exhibited the highest tolerance to Al tolerance with the least hematoxylin staining. Inbred lines 12Y, 16Y, 19Y, 2Y, 20Y, 24Y, 30Y, 27Y, 34Y, 4Y, and 11Y were moderately tolerant. On the other hand, inbred lines 13Y, 18Y, and QSY5 had the least RRG were susceptible. Forty-four testcross hybrids were generated by crossing 22 QPM inbred lines with two open-pollinated variety (OPV) testers. These hybrids were evaluated together with five checks for different agronomic traits. The hybrids were planted in the summer season of 2017/18 and 2018/19 under rain-fed conditions 7 x 7 alpha lattice design was used. The significant variations among the genotypes for grain yield and most other agronomic traits under optimum, acidic conditions and across environments on combined analysis of variance. The hybrid was 14Y x NC (3.22 t/ha), followed by QSY5 x NC (3.02 t/ha) showed the highest yielding. The mean plant height was 226.23 cm, with ranges 197.60 to 254.85cm. The number of kernels per ear was 35, with a range from 29.45 to 40.25. Conversely, the mean ear length was 19.30 cm with a range of 17.65 to 20.95 cm, and the mean ear diameter ranged from 13,50 to 16,05 cm. The highest yielding hybrid, according to ranking, was 14Y x NC (2,93t/ha), which was ranked number 3, followed by 3Y x NC (2,83 t/ha), which was ranked number 4. Twenty-two yellow QPM inbred lines were evaluated for agro-morphological characteristics. A randomized complete block design with three replicates was used under acidic and normal soil conditions at two locations. The mean performance of inbred lines for grain yield ranged from 1.6 t/ha to 3.1 t/ha under optimum conditions, whereas it ranged from 1.1.t/ha to 1.7 t/ha under an acidic environment. The highest grain yielding genotypes under the optimum environment were 14Y, 7Y, and QSY5, while, in the acidic environment, the highest yielders were 3Y, QSY5, and 17Y. The lowest grain yielder under the optimum environment was 16Y at 1.5 t/ha, whereas 6Y, 7Y, 8Y, and 29Y were the most moderate yielders under the acidic environment. Grain yield displayed positive and significant (p<0,05) correlation with ear height (0.59), plant height (0.55), leaf length (0.18), number of leaves (0.37), number of ears per plot (0,54), number of kernels per row, number of rows per ear and thousand kernel weight. Combined ANOVA revealed that the environment effect was significant for all traits except the number of rows per ear and the number of ears in both environments. A total of 71 genotypes (22 inbred lines, forty-four single crosses, and five checks) were evaluated using a 7 x 7 alpha lattice design with two replications in combining ability. Across environments, the analysis showed a mean grain yield record of hybrids that ranged from 1.78 t/ha to 3.42 t/ha. Combined analysis showed only about 4 percent of the 44 hybrids had better grain yield than hybrid checks, whereas about 11 percent of the 44 hybrids had higher grain yield than two of the five hybrid checks. The highest yielding hybrid was 14Y x NC followed by QSY5 x NC. The Mid-parent heterosis (MPH) for grain yield ranged from -32.70 for 11YxObat to 16.50 percent for 14YxNC among the top-yielding genotypes. The highest positive mid-parent heterosis (MPH) for grain yield was observed in hybrid 14YxNC followed by QSY9xNC, QSY5xOBAT, 3YxNC, 13YxNC and 4YxOBAT, while the remaining hybrids exhibited negative estimates. Inbred lines' proportional contributions to the total variances were much higher than the testers for all traits. Whereas the inbred lines' proportional contribution was lower than the interaction of line x tester except on the number of ears which displayed the highest estimates of variances due to SCA effects, significant variation was observed. The GCA effects on grain yield in both environments generally showed no significant difference among inbred lines except for inbred lines such as QSY5 and 34Y but were positive. The selected crosses showed significant SCA effects in a few agronomic yield-related traits in the combined analysis. Among the hybrids, the only crosses that showed significant and positive SCA effects for grain yield were 25YxNC under optimum and 34YxObat under acidic environment. The inbred lines were assessed for tolerance to Al toxicity under laboratory conditions. Overall, the study identified soil acidity tolerant QPM inbred lines with an excellent combining ability for high-yielding QPM test hybrids, grain yield, and related traits. , Thesis (MSc) (Agriculture, Crop Science) -- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Bobotyana, Simthandile
- Date: 2021-04
- Subjects: Corn as food , Plants--Drought tolerance
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20528 , vital:46087
- Description: Maize (Zea mays L) is an essential food grain crop in South Africa and is mainly grown under rainfed conditions by small-scale farmers. Quality Protein Maize (QPM) contains a higher level of two essential amino acids, tryptophan, and lysine when equated to normal maize. Therefore, the QPM in communities is a vital cereal where maize is a staple crop. Among the significant abiotic stresses that adversely affect maize productivity, such as soil fertility. Low soil pH or soil acidity results in nutrient deficiencies, as well as the toxicity of minerals such as manganese (Mn), aluminium (Al), and iron (Fe). The objectives of the study were to: (1) Characterize yellow QPM inbred lines and testcross hybrids for agro-morphological variability under optimum conditions, (2) Determine the response of QPM inbred lines and testcross hybrids to Al toxicity, and (3) Estimate the combining ability of QPM genotypes for the tolerance to Al toxicity. The laboratory assessment for tolerance to Al toxicity revealed a negative relationship between relative root growth RRG and hematoxylin staining; among the inbred lines, the genotype 8Y, 17Y, and 7Y had the highest RRG and net root growth (NRG) values and exhibited the highest tolerance to Al tolerance with the least hematoxylin staining. Inbred lines 12Y, 16Y, 19Y, 2Y, 20Y, 24Y, 30Y, 27Y, 34Y, 4Y, and 11Y were moderately tolerant. On the other hand, inbred lines 13Y, 18Y, and QSY5 had the least RRG were susceptible. Forty-four testcross hybrids were generated by crossing 22 QPM inbred lines with two open-pollinated variety (OPV) testers. These hybrids were evaluated together with five checks for different agronomic traits. The hybrids were planted in the summer season of 2017/18 and 2018/19 under rain-fed conditions 7 x 7 alpha lattice design was used. The significant variations among the genotypes for grain yield and most other agronomic traits under optimum, acidic conditions and across environments on combined analysis of variance. The hybrid was 14Y x NC (3.22 t/ha), followed by QSY5 x NC (3.02 t/ha) showed the highest yielding. The mean plant height was 226.23 cm, with ranges 197.60 to 254.85cm. The number of kernels per ear was 35, with a range from 29.45 to 40.25. Conversely, the mean ear length was 19.30 cm with a range of 17.65 to 20.95 cm, and the mean ear diameter ranged from 13,50 to 16,05 cm. The highest yielding hybrid, according to ranking, was 14Y x NC (2,93t/ha), which was ranked number 3, followed by 3Y x NC (2,83 t/ha), which was ranked number 4. Twenty-two yellow QPM inbred lines were evaluated for agro-morphological characteristics. A randomized complete block design with three replicates was used under acidic and normal soil conditions at two locations. The mean performance of inbred lines for grain yield ranged from 1.6 t/ha to 3.1 t/ha under optimum conditions, whereas it ranged from 1.1.t/ha to 1.7 t/ha under an acidic environment. The highest grain yielding genotypes under the optimum environment were 14Y, 7Y, and QSY5, while, in the acidic environment, the highest yielders were 3Y, QSY5, and 17Y. The lowest grain yielder under the optimum environment was 16Y at 1.5 t/ha, whereas 6Y, 7Y, 8Y, and 29Y were the most moderate yielders under the acidic environment. Grain yield displayed positive and significant (p<0,05) correlation with ear height (0.59), plant height (0.55), leaf length (0.18), number of leaves (0.37), number of ears per plot (0,54), number of kernels per row, number of rows per ear and thousand kernel weight. Combined ANOVA revealed that the environment effect was significant for all traits except the number of rows per ear and the number of ears in both environments. A total of 71 genotypes (22 inbred lines, forty-four single crosses, and five checks) were evaluated using a 7 x 7 alpha lattice design with two replications in combining ability. Across environments, the analysis showed a mean grain yield record of hybrids that ranged from 1.78 t/ha to 3.42 t/ha. Combined analysis showed only about 4 percent of the 44 hybrids had better grain yield than hybrid checks, whereas about 11 percent of the 44 hybrids had higher grain yield than two of the five hybrid checks. The highest yielding hybrid was 14Y x NC followed by QSY5 x NC. The Mid-parent heterosis (MPH) for grain yield ranged from -32.70 for 11YxObat to 16.50 percent for 14YxNC among the top-yielding genotypes. The highest positive mid-parent heterosis (MPH) for grain yield was observed in hybrid 14YxNC followed by QSY9xNC, QSY5xOBAT, 3YxNC, 13YxNC and 4YxOBAT, while the remaining hybrids exhibited negative estimates. Inbred lines' proportional contributions to the total variances were much higher than the testers for all traits. Whereas the inbred lines' proportional contribution was lower than the interaction of line x tester except on the number of ears which displayed the highest estimates of variances due to SCA effects, significant variation was observed. The GCA effects on grain yield in both environments generally showed no significant difference among inbred lines except for inbred lines such as QSY5 and 34Y but were positive. The selected crosses showed significant SCA effects in a few agronomic yield-related traits in the combined analysis. Among the hybrids, the only crosses that showed significant and positive SCA effects for grain yield were 25YxNC under optimum and 34YxObat under acidic environment. The inbred lines were assessed for tolerance to Al toxicity under laboratory conditions. Overall, the study identified soil acidity tolerant QPM inbred lines with an excellent combining ability for high-yielding QPM test hybrids, grain yield, and related traits. , Thesis (MSc) (Agriculture, Crop Science) -- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2021-04
Medicinal properties of Moringa (Moringa Oleifera Lam) leaves and the effect of its use as a supplement on goat growth performance and meat characteristics
- Moyo, Busani https://orcid.org/0000-0001-7002-7266
- Authors: Moyo, Busani https://orcid.org/0000-0001-7002-7266
- Date: 2011-09
- Subjects: Moringa , Medicinal plants
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/24376 , vital:62662
- Description: The main objective of the study was to determine if feeding goats with Moringa oleifera leaves would lead to an increase in productivity and in value of the meat. The proximate, van Soet, atomic absorption spectrophotometric and soxhlet extraction methods were used to determine the nutritional value M. oleifera leaves of the South African. The in-vitro antimicrobial screening methods were used to determine antimicrobial activities M. oleifera extracts while in vitro and invivo models were used to determine the antioxidant activities of M. oleifera leaves. An evaluation of the potential of M. oleifera leaf meal as a feed supplement in terms of its effect on helminth load, goat growth performance, carcass characteristics, meat quality attributes, nutritional and consumer sensory characteristics of goat meat was done. A total of 24, eight month old goats were randomly allocated to dietary treatments of M. oleifera leaf meal (MOL), sunflower seed cake (SC) and GH (grass hay) which was the control. All the groups were fed on basal diet of grass hay ad libitum and 200g wheat bran per head per day. The MOL group was given an additional 200 g of dried M. oleifera leaves while the SC group was offered 170 g sunflower seed cake per head/day. The study showed that the dried leaves had crude protein levels of 30.3 percent, polyunsaturated fatty acids (52.21 percent), Saturated fatty acids (43.31), n-3 (44.57 percent), n-6 (7.64 percent), 19 amino acids, vitamin E (77 mg/100 g) and Beta-carotene (18.5 mg/100 g). The M. oleifera leaf extracts showed antibacterial activities against Escherichia coli, Enterobacter cloace, Proteus vulgaris, Staphylococcus aureus and Micrococcus kristinae. The supplementation of goats with MOL and SC resulted in decreased feacal larval count and lower Haemonchus contortus, Trichostrongylus colubriforms and Oesophagastum columbianum worm burdens than those in the non-supplemented goats. Goats supplemented with SC and MOL had higher average daily weight gain and heavier carcasses than those in the GH group. Higher pH1 scores were observed in chevon from GH diet than the supplemented ones. The MOL and SC supplemented goats had chevon with higher values for lightness (L*) 24 hr post-mortem than the one from the GH group. The redness (a*) values of chevon 24 hr post mortem was highest in MOL supplemented goats. Warner Bratzler shear force (WBSF) values of SC (30.1 N) and MOL (29.8 N) supplemented goats were lower than those from GH diet (32.6 N). Chevon from goats fed GH diet had significantly higher cooking losses (29.5 percent) than that from MOL (25.4 percent) and SC (25.6 percent) fed groups. It was observed that chevon from MOL and SC supplemented groups had higher crude protein (23.57 and 22.95 percent, respectively) than the one from the GH group (21.20 percent). Cholesterol levels were higher in chevon from SC (42.84) supplemented goats than those from MOL (38.76) and GH (35.63 mg). Chevon from GH and MOL group had higher (P < 0.05) proportions of PUFA, n-3, PUFA/SFA ratio and lower n-6/n-3 ratio. Mean consumer scores for first bite, aroma, flavour and juiceness were higher in the MOL group than in the GH group (P < 0.05). The acetone extract exhibited higher concentrations of total flavonoids, flavonols, phenolics. The acetone extracts depicted higher percentage inhibition against DPPH, ABTS and nitric oxide radicals which were comparable with reference antioxidant (vitamin C and BHT). The M. oleifera leaf meal increased the antioxidant activity of GSH, SOD and catalase. Moringa oleifera leaves also exhibited medicinal properties by having anthelmintic, antibacterial activities and showed antioxidant properties. It was also observed that protein supplementation improved the animal growth performance, the physico-chemical characteristics, nutritional and fatty acids composition of meat hence meeting the consumer needs. , Thesis (PhD) -- Faculty of Science and Agriculture, 2011
- Full Text:
- Date Issued: 2011-09
- Authors: Moyo, Busani https://orcid.org/0000-0001-7002-7266
- Date: 2011-09
- Subjects: Moringa , Medicinal plants
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/24376 , vital:62662
- Description: The main objective of the study was to determine if feeding goats with Moringa oleifera leaves would lead to an increase in productivity and in value of the meat. The proximate, van Soet, atomic absorption spectrophotometric and soxhlet extraction methods were used to determine the nutritional value M. oleifera leaves of the South African. The in-vitro antimicrobial screening methods were used to determine antimicrobial activities M. oleifera extracts while in vitro and invivo models were used to determine the antioxidant activities of M. oleifera leaves. An evaluation of the potential of M. oleifera leaf meal as a feed supplement in terms of its effect on helminth load, goat growth performance, carcass characteristics, meat quality attributes, nutritional and consumer sensory characteristics of goat meat was done. A total of 24, eight month old goats were randomly allocated to dietary treatments of M. oleifera leaf meal (MOL), sunflower seed cake (SC) and GH (grass hay) which was the control. All the groups were fed on basal diet of grass hay ad libitum and 200g wheat bran per head per day. The MOL group was given an additional 200 g of dried M. oleifera leaves while the SC group was offered 170 g sunflower seed cake per head/day. The study showed that the dried leaves had crude protein levels of 30.3 percent, polyunsaturated fatty acids (52.21 percent), Saturated fatty acids (43.31), n-3 (44.57 percent), n-6 (7.64 percent), 19 amino acids, vitamin E (77 mg/100 g) and Beta-carotene (18.5 mg/100 g). The M. oleifera leaf extracts showed antibacterial activities against Escherichia coli, Enterobacter cloace, Proteus vulgaris, Staphylococcus aureus and Micrococcus kristinae. The supplementation of goats with MOL and SC resulted in decreased feacal larval count and lower Haemonchus contortus, Trichostrongylus colubriforms and Oesophagastum columbianum worm burdens than those in the non-supplemented goats. Goats supplemented with SC and MOL had higher average daily weight gain and heavier carcasses than those in the GH group. Higher pH1 scores were observed in chevon from GH diet than the supplemented ones. The MOL and SC supplemented goats had chevon with higher values for lightness (L*) 24 hr post-mortem than the one from the GH group. The redness (a*) values of chevon 24 hr post mortem was highest in MOL supplemented goats. Warner Bratzler shear force (WBSF) values of SC (30.1 N) and MOL (29.8 N) supplemented goats were lower than those from GH diet (32.6 N). Chevon from goats fed GH diet had significantly higher cooking losses (29.5 percent) than that from MOL (25.4 percent) and SC (25.6 percent) fed groups. It was observed that chevon from MOL and SC supplemented groups had higher crude protein (23.57 and 22.95 percent, respectively) than the one from the GH group (21.20 percent). Cholesterol levels were higher in chevon from SC (42.84) supplemented goats than those from MOL (38.76) and GH (35.63 mg). Chevon from GH and MOL group had higher (P < 0.05) proportions of PUFA, n-3, PUFA/SFA ratio and lower n-6/n-3 ratio. Mean consumer scores for first bite, aroma, flavour and juiceness were higher in the MOL group than in the GH group (P < 0.05). The acetone extract exhibited higher concentrations of total flavonoids, flavonols, phenolics. The acetone extracts depicted higher percentage inhibition against DPPH, ABTS and nitric oxide radicals which were comparable with reference antioxidant (vitamin C and BHT). The M. oleifera leaf meal increased the antioxidant activity of GSH, SOD and catalase. Moringa oleifera leaves also exhibited medicinal properties by having anthelmintic, antibacterial activities and showed antioxidant properties. It was also observed that protein supplementation improved the animal growth performance, the physico-chemical characteristics, nutritional and fatty acids composition of meat hence meeting the consumer needs. , Thesis (PhD) -- Faculty of Science and Agriculture, 2011
- Full Text:
- Date Issued: 2011-09
Evaluation of cellulase and xylanase production by two actinobacteria species belonging to the Micrococcus genus isolated from decaying lignocellulosic biomass
- Mmango-Kaseke, Ziyanda https://orcid.org/0000-0002-8936-1149
- Authors: Mmango-Kaseke, Ziyanda https://orcid.org/0000-0002-8936-1149
- Date: 2016-05
- Subjects: Lignocellulose , Biomass energy
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/24197 , vital:62442
- Description: Bacteria were isolated from sawdust and screened for cellulase and xylanase production on carboxyl methyl cellulose (CMC) and birchwood xylan agar. The bacteria showing halo forms around the colony were selected for further analyses and those isolates with the highest cumulative halozone size (isolate PLY1 and MLY10) were chosen for detailed studies. Evaluation of cellulase and xylanase production by saw dust actinobacterial species whose 16S rDNA nucleotide sequences were deposited in GenBank as Micrococcus luteus strain SAMRC-UFH3 with accession number KU171371 and Micrococcus yunnanensis strain SAMRC-UFH4 with accession number KU171372. Optimum culture conditions for the production of cellulase for respective axenic culture include incubation period (96 h), incubation temperature (25oC), agitation speed (50 rpm), and pH 5. For xylanase production, the optimum culture conditions in the presence of 1percent (w/v) birchwood xylan include incubation period (84 h), incubation temperature (25oC), agitation speed (200 rpm), and pH 10. For Micrococcus yunnanensis strain SAMRC-UFH4 cellulase production was optimal under such conditions as, incubation temperature (30oC), agitation speed (0 rpm), and pH 5, while xylanase production was optimal at, incubation temperature (30oC), agitation speed (150 rpm), and pH 10. The high cellulase and xylanase activity obtained from these isolates suggest suitability of the organisms as important candidates for commercial application. , Thesis (MSc) -- Faculty of Science and Agriculture, 2016
- Full Text:
- Date Issued: 2016-05
- Authors: Mmango-Kaseke, Ziyanda https://orcid.org/0000-0002-8936-1149
- Date: 2016-05
- Subjects: Lignocellulose , Biomass energy
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/24197 , vital:62442
- Description: Bacteria were isolated from sawdust and screened for cellulase and xylanase production on carboxyl methyl cellulose (CMC) and birchwood xylan agar. The bacteria showing halo forms around the colony were selected for further analyses and those isolates with the highest cumulative halozone size (isolate PLY1 and MLY10) were chosen for detailed studies. Evaluation of cellulase and xylanase production by saw dust actinobacterial species whose 16S rDNA nucleotide sequences were deposited in GenBank as Micrococcus luteus strain SAMRC-UFH3 with accession number KU171371 and Micrococcus yunnanensis strain SAMRC-UFH4 with accession number KU171372. Optimum culture conditions for the production of cellulase for respective axenic culture include incubation period (96 h), incubation temperature (25oC), agitation speed (50 rpm), and pH 5. For xylanase production, the optimum culture conditions in the presence of 1percent (w/v) birchwood xylan include incubation period (84 h), incubation temperature (25oC), agitation speed (200 rpm), and pH 10. For Micrococcus yunnanensis strain SAMRC-UFH4 cellulase production was optimal under such conditions as, incubation temperature (30oC), agitation speed (0 rpm), and pH 5, while xylanase production was optimal at, incubation temperature (30oC), agitation speed (150 rpm), and pH 10. The high cellulase and xylanase activity obtained from these isolates suggest suitability of the organisms as important candidates for commercial application. , Thesis (MSc) -- Faculty of Science and Agriculture, 2016
- Full Text:
- Date Issued: 2016-05
Synthesis and characterization of molybdenum dichalcogenides nanoparticles via solution-processed technique for photovoltaic applications
- Authors: Shelter, Chikukwa Evernice
- Date: 2021-02
- Subjects: Nanoparticles , Colloids
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20653 , vital:46417
- Description: Energy generated from non-renewable energy sources has a drawback of prompted outflow of ozone harming substances. These drawbacks of the non-renewable energy have quickened innovative work of renewable power sources, since they have an advantage of the provision of a better, preserved, decent environment that is free from natural contamination and commotion. Photovoltaic devices are prevalent in improving the green energy utilization and defeating the natural concerns yielded from the current most overwhelming energy sources. Herein, the synthesis, characterization, and application of Molybdenum chalcogenide nanoparticles (NP) as alternative sources in the absorber layer of quantum dot solar sensitized cells (QDSSCs) is discussed. The MoS2 NPs were synthesized from the aliphatic and aromatic dithiocarbamate (DTC) ligands and complexes as precursors. The successful synthesis of the DTC ligands and MoDTC complexes was confirmed through characterization with a variety of techniques including 1H and 13C-NMR, Raman Spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), Ultraviolet-visible spectroscopy (UV-VIS), Thermogravimetric analysis (TGA) and Derivative thermogravimetric (DTG) analysis. The synthesized MoDTC complexes (precursors) were further used in the synthesis of MoS2 nanoparticles. A bottom -up colloidal approach was employed for the synthesis of the MoX2 NPs. The successful synthesis of the NP was confirmed as the results from the diffractive peaks obtained from XRD which were positive and agreed in comparison with the standard. The diffractive peaks were shown in the planes (100), (002), (100) and (105) for MoS2 nanoparticles; (002), (100), (103) and (110) for MoSe2 and (0002), (0004), (103) as well as (0006) for the MoTe2 nanoparticles. The MoSe2 nanoparticles showed the least size of the nanoparticles followed by MoTe2 and lastly MoS2. These results agreed with the results obtained using SEM analysis. For the optical properties of the nanoparticles, UV-VIS and PL were used, the shift of the peaks from the red shift (600 nm) to the blue shift 270-5 nm and 287-9 nm (UV-VIS) confirmed that the nanoparticles were quantum confined. The application of the MoX2 NPs in QDSSCs was done with MoSe2 showing the greatest PCE of 7.86 percent followed by MoTe2 6.93 percent and lastly MoS2 with a PCE of 6.05 percent and 5.47 percent. , Thesis (MSc) (Chemistry) -- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2021-02
- Authors: Shelter, Chikukwa Evernice
- Date: 2021-02
- Subjects: Nanoparticles , Colloids
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20653 , vital:46417
- Description: Energy generated from non-renewable energy sources has a drawback of prompted outflow of ozone harming substances. These drawbacks of the non-renewable energy have quickened innovative work of renewable power sources, since they have an advantage of the provision of a better, preserved, decent environment that is free from natural contamination and commotion. Photovoltaic devices are prevalent in improving the green energy utilization and defeating the natural concerns yielded from the current most overwhelming energy sources. Herein, the synthesis, characterization, and application of Molybdenum chalcogenide nanoparticles (NP) as alternative sources in the absorber layer of quantum dot solar sensitized cells (QDSSCs) is discussed. The MoS2 NPs were synthesized from the aliphatic and aromatic dithiocarbamate (DTC) ligands and complexes as precursors. The successful synthesis of the DTC ligands and MoDTC complexes was confirmed through characterization with a variety of techniques including 1H and 13C-NMR, Raman Spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), Ultraviolet-visible spectroscopy (UV-VIS), Thermogravimetric analysis (TGA) and Derivative thermogravimetric (DTG) analysis. The synthesized MoDTC complexes (precursors) were further used in the synthesis of MoS2 nanoparticles. A bottom -up colloidal approach was employed for the synthesis of the MoX2 NPs. The successful synthesis of the NP was confirmed as the results from the diffractive peaks obtained from XRD which were positive and agreed in comparison with the standard. The diffractive peaks were shown in the planes (100), (002), (100) and (105) for MoS2 nanoparticles; (002), (100), (103) and (110) for MoSe2 and (0002), (0004), (103) as well as (0006) for the MoTe2 nanoparticles. The MoSe2 nanoparticles showed the least size of the nanoparticles followed by MoTe2 and lastly MoS2. These results agreed with the results obtained using SEM analysis. For the optical properties of the nanoparticles, UV-VIS and PL were used, the shift of the peaks from the red shift (600 nm) to the blue shift 270-5 nm and 287-9 nm (UV-VIS) confirmed that the nanoparticles were quantum confined. The application of the MoX2 NPs in QDSSCs was done with MoSe2 showing the greatest PCE of 7.86 percent followed by MoTe2 6.93 percent and lastly MoS2 with a PCE of 6.05 percent and 5.47 percent. , Thesis (MSc) (Chemistry) -- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2021-02
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
Investigations of water deficit interactions with heat and elevated carbon dioxide in wheat
- Authors: Mavindidze, Peter
- Date: 2021-02
- Subjects: Plants--Effect of heat on , Growth (Plants)
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20664 , vital:46422
- Description: Future climate is predicted to be characterised by elevated carbon dioxide (eCO2), as well as more incidences of heat and water deficit. eCO2 has been widely reported as enhancing growth, biomass and grain yield. To investigate the interactive effects of abiotic stresses on genotypic performance, an experiment was established in open-top chambers at the University of Rhodes eCO2 facility in Grahamstown, South Africa. The specific objectives of the study were: i) to evaluate the effects of eCO2 on wheat grain yield, yield components and grain quality under heat and terminal water deficit conditions; ii) to identify cultivar sources of tolerance to combined water deficit and heat stress under eCO2; iii) to identify appropriate stress indices that can be used as screening tools for tolerance to combined effects of water deficit and heat stress under eCO2. A total of 19 wheat genotypes were evaluated in three environments varying in CO2, temperature and water deficit during the 2019 winter season. The experiment was laid out in a split-split plot design arranged in blocks inside the chambers. The parameters recorded were: leaf water potential (LWP), biomass content (TB), number of productive tillers (NPT), days to flowering (DTA), days to maturity (DTM), plant height (PH), thousand kernel weight (TKW), number of kernels per spike (KPS), kernel weight per spike (KWS) and total grain weight (TGW). The following stress indices were determined: tolerance index, stress tolerance, yield susceptibility index, mean productivity, geometric mean productivity, stress intensity index and yield index. Elevated atmospheric CO2 ameliorated the negative effects of combined heat and water deficit stress by enhancing LWP, NPT, KPS, TB and TGW. Wheat genotypes responded the same way to CO2 with respect to grain yield. Furthermore, adequate water supply mitigated the adverse effects of heat stress. In addition, the combined effects of eCO2, heat and water deficit are confounding and hypo-additive in nature. The separation of environmental effects revealed that significant genotypic responses on grain yield and biomass were caused by heat and water deficit stress, while eCO2 mitigated their negative effects, promoting growth and reproduction. Both Principal component analysis (PCA) biplot analysis and cultivar superiority measure proved to be reliable statistical tools since they managed to identify 13-5HTSBWYT-H18, Ncema and SST8135 as having both specific adaptations to future climates as well as wide adaption to multiple environments. The genotypes may be used as sources (parents for crosses) for wide adaptation in breeding programmes in the wake of predicted future climate environments. PCA biplot analysis identified mean productivity (MP) and geometric mean productivity (GMP) as the best indices; hence can also be as secondary traits complimenting traditional agronomic and physiological traits in wheat breeding under environments varying in water availability, CO2 and temperature. The interactive effects of eCO2 with heat and water deficit stress did not significantly compromise the grain physical characteristics, flour extraction, protein content, falling number and flour ash. eCO2 ameliorated the negative effects of heat and water deficit by increasing protein content by 4.75 percent , Thesis (MSc) (Crop Science) -- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2021-02
- Authors: Mavindidze, Peter
- Date: 2021-02
- Subjects: Plants--Effect of heat on , Growth (Plants)
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20664 , vital:46422
- Description: Future climate is predicted to be characterised by elevated carbon dioxide (eCO2), as well as more incidences of heat and water deficit. eCO2 has been widely reported as enhancing growth, biomass and grain yield. To investigate the interactive effects of abiotic stresses on genotypic performance, an experiment was established in open-top chambers at the University of Rhodes eCO2 facility in Grahamstown, South Africa. The specific objectives of the study were: i) to evaluate the effects of eCO2 on wheat grain yield, yield components and grain quality under heat and terminal water deficit conditions; ii) to identify cultivar sources of tolerance to combined water deficit and heat stress under eCO2; iii) to identify appropriate stress indices that can be used as screening tools for tolerance to combined effects of water deficit and heat stress under eCO2. A total of 19 wheat genotypes were evaluated in three environments varying in CO2, temperature and water deficit during the 2019 winter season. The experiment was laid out in a split-split plot design arranged in blocks inside the chambers. The parameters recorded were: leaf water potential (LWP), biomass content (TB), number of productive tillers (NPT), days to flowering (DTA), days to maturity (DTM), plant height (PH), thousand kernel weight (TKW), number of kernels per spike (KPS), kernel weight per spike (KWS) and total grain weight (TGW). The following stress indices were determined: tolerance index, stress tolerance, yield susceptibility index, mean productivity, geometric mean productivity, stress intensity index and yield index. Elevated atmospheric CO2 ameliorated the negative effects of combined heat and water deficit stress by enhancing LWP, NPT, KPS, TB and TGW. Wheat genotypes responded the same way to CO2 with respect to grain yield. Furthermore, adequate water supply mitigated the adverse effects of heat stress. In addition, the combined effects of eCO2, heat and water deficit are confounding and hypo-additive in nature. The separation of environmental effects revealed that significant genotypic responses on grain yield and biomass were caused by heat and water deficit stress, while eCO2 mitigated their negative effects, promoting growth and reproduction. Both Principal component analysis (PCA) biplot analysis and cultivar superiority measure proved to be reliable statistical tools since they managed to identify 13-5HTSBWYT-H18, Ncema and SST8135 as having both specific adaptations to future climates as well as wide adaption to multiple environments. The genotypes may be used as sources (parents for crosses) for wide adaptation in breeding programmes in the wake of predicted future climate environments. PCA biplot analysis identified mean productivity (MP) and geometric mean productivity (GMP) as the best indices; hence can also be as secondary traits complimenting traditional agronomic and physiological traits in wheat breeding under environments varying in water availability, CO2 and temperature. The interactive effects of eCO2 with heat and water deficit stress did not significantly compromise the grain physical characteristics, flour extraction, protein content, falling number and flour ash. eCO2 ameliorated the negative effects of heat and water deficit by increasing protein content by 4.75 percent , Thesis (MSc) (Crop Science) -- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2021-02
Groundwater exploration using borehole and geophysical techniques in the east of Raymond Mhlaba Local Municipality (formerly Nkonkobe Local Municipality) in the Eastern Cape Province, South Africa
- Authors: Xanga, Sithule
- Date: 2021-07
- Subjects: Groundwater ecology , Geophysical instruments , Borehole gravimetry
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22643 , vital:52616
- Description: The study area lies in the eastern portion of Raymond Mhlaba Local Municipality (RMLM), formerly known as Nkonkobe Local Municipality within the Eastern Cape Province of South Africa in the southeastern portion of the main Karoo Basin. Its northen part is mountainous with high altitude of about 1500 m with dense vegetation, whereas the southern part attains low altitude of about 600 m with sparse vegetation. The entire study area is covered on the surface by the Beaufort Group sediments comprised of three geological formations namely Middleton Formation, Balfour Formation members (Oudeberg, Daggaboersnek, Baberskrans, Elandsberg, and Pilangkloof), and the Katberg Formation. Karoo igneous bodies (dolerite dykes and sills) intruded the sediments causing fracturing. The area receives mean annual precipitation of about 54 mm. It is semi-arid to dry with insufficient surface water resources and hence the need for this research to explore for potential groundwater. Many techniques were employed to reveal the surface and subsurface geology, including groundwater potential areas using climate data, vegetation cover, borehole data analysis, geological field mapping, rock samples collection for petrographic analysis, a density-porosity determination, magnetic data analysis, and electrical resistivity tomography. The study area was divided into seven sub-regions, SR1 to SR7. The climate data showed that the area experiences high monthly average temperatures of about 21.6 °C during the summer, and is a semi-arid to dry region. Vegetation cover is dense in the mountainous northern part of the study area. It receives comparatively high rainfall, experiences less evapotranspiration than the southern part the low altitude, receives less rainfall, and has relatively high temperatures and evapotranspiration. A total of 385 boreholes from the Department Water and Sanitation were analysed and these showed that sub-regions SR1 up to SR7 had average borehole depths ranging from 51.9 to 67.7 m, water strike depths from 13.8 to 21.7 m and yields from 0.8 to 1.9 L/s. Sub-regions SR2, SR4, SR5, while SR7 have an average yield ≥ 1.4 L/s up to 1.9 L/s and are classified in this study as having a good or high groundwater yield potential. Fifteen thin sections were studied indicating that the Beaufort Group has mudstone, shale and fine-grained sandstone. The latter was dominant in the studied thin sections with 70 – 80 % quartz, 15 – 20 % groundmass, 5 – 10 % of feldspars, 2 – 5 % biotite, and some had vein like cracks filled with clay cement. Laboratory studies show average dry densities for the formations vary from 2.44 to 2.65 g/cm3, and porosities range from 1.6 to 4.0 %. Magnetic grid data obtained from the Council for Geoscience (CGS) were reduced to the pole, first vertical derivative and analytic signal maps were generated to delineate magnetic sources in the sediments. The magnetic anomalies showed lineaments and ring-shaped patterns that were interpreted to be due to Karoo dykes and sills, respectively. Some of these intrusions are mapped on the geological map and quite a number are not mapped as they are under sediment cover. The intrusions are important in groundwater exploration as they would have caused fracturing of surrounding formations causing increased secondary porosity and permeability. Further, they are groundwater localisers. Electrical resistivity tomography (ERT) was carried out at 12 selected sites using the dipoledipole and Wenner-Schlumberger arrays, with a maximum cable length of 360 m was used with an approximate maximum depth of investigation of 70 m. Most of the sites’ inverted models show a low resistivity top layer of about 10 m thickness, which is inferred to be topsoil with moisture/water and or clayey content. A high resistivity second layer underneath the top layer, and is interpreted to be slightly weathered sandstone at its top grading into compact sandstones at the bottom of the investigation depth. Four site results show models with an intermediate layer between the top and bottom layers consisting of moderate resistivity values due to mudstones. Most of the models have vertical, narrow, low resistivity zones extending from the surface to the bottom layer, interpreted as fracturing. The top layer could be an unconfined aquifer during the wet months but is likely to dry up during the dry, hot months. The inferred fractures that extend deeper from the surface could be good groundwater targets to drill boreholes. Dolerite intrusions can act as natural groundwater barriers depending on their orientation hence such structures are the main targets when searching for groundwater. Vegetation cover observed on satellite images of remote sensing can be used along with other techniques to explore for groundwater. It is recommended that future ERT surveys should measure both electrical resistivity and induced polarization chargeability to discriminate between water and clay influence. , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-07
- Authors: Xanga, Sithule
- Date: 2021-07
- Subjects: Groundwater ecology , Geophysical instruments , Borehole gravimetry
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22643 , vital:52616
- Description: The study area lies in the eastern portion of Raymond Mhlaba Local Municipality (RMLM), formerly known as Nkonkobe Local Municipality within the Eastern Cape Province of South Africa in the southeastern portion of the main Karoo Basin. Its northen part is mountainous with high altitude of about 1500 m with dense vegetation, whereas the southern part attains low altitude of about 600 m with sparse vegetation. The entire study area is covered on the surface by the Beaufort Group sediments comprised of three geological formations namely Middleton Formation, Balfour Formation members (Oudeberg, Daggaboersnek, Baberskrans, Elandsberg, and Pilangkloof), and the Katberg Formation. Karoo igneous bodies (dolerite dykes and sills) intruded the sediments causing fracturing. The area receives mean annual precipitation of about 54 mm. It is semi-arid to dry with insufficient surface water resources and hence the need for this research to explore for potential groundwater. Many techniques were employed to reveal the surface and subsurface geology, including groundwater potential areas using climate data, vegetation cover, borehole data analysis, geological field mapping, rock samples collection for petrographic analysis, a density-porosity determination, magnetic data analysis, and electrical resistivity tomography. The study area was divided into seven sub-regions, SR1 to SR7. The climate data showed that the area experiences high monthly average temperatures of about 21.6 °C during the summer, and is a semi-arid to dry region. Vegetation cover is dense in the mountainous northern part of the study area. It receives comparatively high rainfall, experiences less evapotranspiration than the southern part the low altitude, receives less rainfall, and has relatively high temperatures and evapotranspiration. A total of 385 boreholes from the Department Water and Sanitation were analysed and these showed that sub-regions SR1 up to SR7 had average borehole depths ranging from 51.9 to 67.7 m, water strike depths from 13.8 to 21.7 m and yields from 0.8 to 1.9 L/s. Sub-regions SR2, SR4, SR5, while SR7 have an average yield ≥ 1.4 L/s up to 1.9 L/s and are classified in this study as having a good or high groundwater yield potential. Fifteen thin sections were studied indicating that the Beaufort Group has mudstone, shale and fine-grained sandstone. The latter was dominant in the studied thin sections with 70 – 80 % quartz, 15 – 20 % groundmass, 5 – 10 % of feldspars, 2 – 5 % biotite, and some had vein like cracks filled with clay cement. Laboratory studies show average dry densities for the formations vary from 2.44 to 2.65 g/cm3, and porosities range from 1.6 to 4.0 %. Magnetic grid data obtained from the Council for Geoscience (CGS) were reduced to the pole, first vertical derivative and analytic signal maps were generated to delineate magnetic sources in the sediments. The magnetic anomalies showed lineaments and ring-shaped patterns that were interpreted to be due to Karoo dykes and sills, respectively. Some of these intrusions are mapped on the geological map and quite a number are not mapped as they are under sediment cover. The intrusions are important in groundwater exploration as they would have caused fracturing of surrounding formations causing increased secondary porosity and permeability. Further, they are groundwater localisers. Electrical resistivity tomography (ERT) was carried out at 12 selected sites using the dipoledipole and Wenner-Schlumberger arrays, with a maximum cable length of 360 m was used with an approximate maximum depth of investigation of 70 m. Most of the sites’ inverted models show a low resistivity top layer of about 10 m thickness, which is inferred to be topsoil with moisture/water and or clayey content. A high resistivity second layer underneath the top layer, and is interpreted to be slightly weathered sandstone at its top grading into compact sandstones at the bottom of the investigation depth. Four site results show models with an intermediate layer between the top and bottom layers consisting of moderate resistivity values due to mudstones. Most of the models have vertical, narrow, low resistivity zones extending from the surface to the bottom layer, interpreted as fracturing. The top layer could be an unconfined aquifer during the wet months but is likely to dry up during the dry, hot months. The inferred fractures that extend deeper from the surface could be good groundwater targets to drill boreholes. Dolerite intrusions can act as natural groundwater barriers depending on their orientation hence such structures are the main targets when searching for groundwater. Vegetation cover observed on satellite images of remote sensing can be used along with other techniques to explore for groundwater. It is recommended that future ERT surveys should measure both electrical resistivity and induced polarization chargeability to discriminate between water and clay influence. , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-07
Comparative performance of 3-kWp ranges Solar Photovoltaic Systems under varying meteorological conditions in Alice, Eastern Cape Province, South Africa
- Apeh, Oliver Okechukwu https://orcid.org/0000-0003-4076-0613
- Authors: Apeh, Oliver Okechukwu https://orcid.org/0000-0003-4076-0613
- Date: 2021-08
- Subjects: Photovoltaic power systems , Solar energy
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/21567 , vital:48888
- Description: PVsystem has recently emerged in South Africa as a way to curb the country’s persistent shortage of electricity. A wide effort for the past few decades have targeted at study, testing and demonstration of PV power systems which was established all over the country as an appropriate measure to tackle transportation, agriculture, industry, commercial as well as domestic activities. In view of these drives, both off-grid and grid-connected PV systems are being applied. However, operating a building with an off-grid system is one of the means to providing the possibility of energy access to places far away from the national grid. As an off-grid choice, 50 W SHS is being distributed to customers in distant rustic parts of the country where grid option is difficult to access. But the SHS of the stated capacity can barely generate 0.3 to 0.4 kWh of electric energy per day, even at the optimal solar radiations. In view of this, more efforts are directed at expanding the off-grid systems to accommodate large rural households in South Africa. This thesis is dedicated to a study on the various configurations and components of PV power plant as a way to enhance electricity generations in South Africa. To this effect, different power plants were considered at SolarWatt park, University of Fort Hare with the aim to conduct a comparative analysis of the charge controllers with respect to the charge and discharge rates of their respective batteries. The grid-connected PV power generation was classified into hybrid PV and grid-assisted PV, while off-grid is a BIPV. These power plants generations were installed for the purpose of research level with a total capacity of 11.4 kW. The off-grid system is made up of HIT modules, FlexMax80 charge controller, Victron energy inverter and M-Molar battery bank. The hybrid and grid-assisted systems each consist of 15 polycrystalline modules and Microcare charge controllers. In addition, hybrid comprises SMA Sunny Island inverter and Trojan battery bank whereas grid-assisted consist of Microcare inverter and Hoppercke battery bank. The first part of the experimental work was monitored, and the meteorological parameters which are ambient temperature, solar radiation, relative humidity and wind speed, were measured and evaluated while electrical parameters includes PV current and voltage, MPPT current and voltage, battery current and voltage and inverter current and voltage were also measured and evaluated in the second part of the experiment. This lasted for a period of four years, starting from 1st January 2017 to 31st December 2020. Similarly, the second aspect was to monitor the electrical performance of the three systems and was performed for a period of six months, starting from January to June 2019. During the second experiment, hybrid and grid-assisted systems were reconfigured to function as off-grid systems. Moreover, a detailed data acquisition system designed to measure and record both meteorological and electrical parameters affecting the performance of the systems. The electrical parameters include PV current and voltage, MPPT current, battery current and voltage and inverter current and voltage. Other parameters in the measurements are; inverter efficiency, active and apparent power, while meteorological parameters include; solar irradiance, ambient temperature, relative humidity, wind speed and direction. The meteorological results show that the maximum and minimum mean amount of global solar radiation was 7.34 kWh/m2/day in December and 3.03 kWh/m2/day in June, respectively, while the average radiation and temperature for the typical year were 4.98 kWh/m2/day and 16.88 oC respectively. The solar radiations obtained are within the range in major places in South Africa. Similarly, an average wind speed of 2.5 m/s is experienced in Alice in a year and average solar radiation of 606.06 W/m2 in summer and 346.17 W/m2 in winter. The three lead-acid battery systems monitored under the electrical aspect are M-Molar, Trojan and Hoppecke battery systems. It was established that the charging current decreases gradually from 27.7 to 18.5 A for the M-Molar while Hoppecke and Trojan deceased respectively from 15 to 10 A and 23 to 13 A at the end of each phase by charging it at the maximum power point of the PV array. It was equally found that the M-Molar battery current has the highest rate of charging and quickest rate of discharging in comparison to the other two batteries. Finally, from the results gotten from this research, we may propose that the solar PV system contributes significantly to the satisfaction of the needed electricity in South Africa. , Thesis (PhD) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-08
- Authors: Apeh, Oliver Okechukwu https://orcid.org/0000-0003-4076-0613
- Date: 2021-08
- Subjects: Photovoltaic power systems , Solar energy
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/21567 , vital:48888
- Description: PVsystem has recently emerged in South Africa as a way to curb the country’s persistent shortage of electricity. A wide effort for the past few decades have targeted at study, testing and demonstration of PV power systems which was established all over the country as an appropriate measure to tackle transportation, agriculture, industry, commercial as well as domestic activities. In view of these drives, both off-grid and grid-connected PV systems are being applied. However, operating a building with an off-grid system is one of the means to providing the possibility of energy access to places far away from the national grid. As an off-grid choice, 50 W SHS is being distributed to customers in distant rustic parts of the country where grid option is difficult to access. But the SHS of the stated capacity can barely generate 0.3 to 0.4 kWh of electric energy per day, even at the optimal solar radiations. In view of this, more efforts are directed at expanding the off-grid systems to accommodate large rural households in South Africa. This thesis is dedicated to a study on the various configurations and components of PV power plant as a way to enhance electricity generations in South Africa. To this effect, different power plants were considered at SolarWatt park, University of Fort Hare with the aim to conduct a comparative analysis of the charge controllers with respect to the charge and discharge rates of their respective batteries. The grid-connected PV power generation was classified into hybrid PV and grid-assisted PV, while off-grid is a BIPV. These power plants generations were installed for the purpose of research level with a total capacity of 11.4 kW. The off-grid system is made up of HIT modules, FlexMax80 charge controller, Victron energy inverter and M-Molar battery bank. The hybrid and grid-assisted systems each consist of 15 polycrystalline modules and Microcare charge controllers. In addition, hybrid comprises SMA Sunny Island inverter and Trojan battery bank whereas grid-assisted consist of Microcare inverter and Hoppercke battery bank. The first part of the experimental work was monitored, and the meteorological parameters which are ambient temperature, solar radiation, relative humidity and wind speed, were measured and evaluated while electrical parameters includes PV current and voltage, MPPT current and voltage, battery current and voltage and inverter current and voltage were also measured and evaluated in the second part of the experiment. This lasted for a period of four years, starting from 1st January 2017 to 31st December 2020. Similarly, the second aspect was to monitor the electrical performance of the three systems and was performed for a period of six months, starting from January to June 2019. During the second experiment, hybrid and grid-assisted systems were reconfigured to function as off-grid systems. Moreover, a detailed data acquisition system designed to measure and record both meteorological and electrical parameters affecting the performance of the systems. The electrical parameters include PV current and voltage, MPPT current, battery current and voltage and inverter current and voltage. Other parameters in the measurements are; inverter efficiency, active and apparent power, while meteorological parameters include; solar irradiance, ambient temperature, relative humidity, wind speed and direction. The meteorological results show that the maximum and minimum mean amount of global solar radiation was 7.34 kWh/m2/day in December and 3.03 kWh/m2/day in June, respectively, while the average radiation and temperature for the typical year were 4.98 kWh/m2/day and 16.88 oC respectively. The solar radiations obtained are within the range in major places in South Africa. Similarly, an average wind speed of 2.5 m/s is experienced in Alice in a year and average solar radiation of 606.06 W/m2 in summer and 346.17 W/m2 in winter. The three lead-acid battery systems monitored under the electrical aspect are M-Molar, Trojan and Hoppecke battery systems. It was established that the charging current decreases gradually from 27.7 to 18.5 A for the M-Molar while Hoppecke and Trojan deceased respectively from 15 to 10 A and 23 to 13 A at the end of each phase by charging it at the maximum power point of the PV array. It was equally found that the M-Molar battery current has the highest rate of charging and quickest rate of discharging in comparison to the other two batteries. Finally, from the results gotten from this research, we may propose that the solar PV system contributes significantly to the satisfaction of the needed electricity in South Africa. , Thesis (PhD) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-08
Investigating communal farmer’s perceptions on production practices and evaluating pre-slaughter responsiveness of extensively reared Boran and Nguni steers
- Guzi, Anelisa https://orcid.org/0000-0001-5568-3396
- Authors: Guzi, Anelisa https://orcid.org/0000-0001-5568-3396
- Date: 2020-01
- Subjects: Boran cattle , Nguni cattle , Cattle breeds
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22721 , vital:52672
- Description: This study's overall objective was to investigate communal farmers' perceptions on production practices and evaluate pre-slaughter responsiveness of extensively reared Boran and Nguni steers. On objective one farmers’ knowledge and perceptions on cattle breeds, management, and marketing channels in selected villages of Alice, Eastern Cape, South Africa were evaluated. Interviews were conducted using a structured questionnaire divided into demographic information and relevant cattle production practices, following a snowball technique to select 101 cattle-keeping households from Gaga, Ntselamanzi, and Ncerha villages. Most of the interviewed cattle farmers were males (65percent), in the age range of 40-60 years, with a primary-matric educational level. Among others, they highlighted financial security (47percent) and traditional ceremonies (26percent) as the reasons for keeping cattle. Most dominant in their herds were the Boran (49percent) and crossbreds (23percent) reared extensively with some supplementation (nutritional and medicinal). Their breed selection was based on disease and tick tolerance, temperament, and product (milk and meat) quality. It was noted that most of the interviewed cattle owners have the basic knowledge of good management practices, breed differences, and marketing chains. They related to low productivity to diseases, lack of knowledge, and poor resources. On the second objective pre-slaughter blood-based stress indicators and their subsequent effects were evaluated on beef quality of extensively reared Nguni and Boran steers . Twenty steers (10 Nguni and 10 Boran) aged 18 months were divided into two groups (with 5 of each breed per group) and transported from the University of Fort Hare Honeydale farm to the East London abattoir in the morning and afternoon trips. Upon arrival at the abattoir, the steers were held in lairage units for 24 hours (group 1) and 16 hours (group 2) until slaughter. Blood samples were drawn using a needle and vacutainer tubes from each steer's jugular vein at the farm before transportation, upon arrival at the abattoir, and during slaughter to perform cortisol, glucose, and routine haematological analysis. M. longissimus dorsi samples were harvested on the left side of each carcass to measure the meat quality attributes. Interactions between the observed production-stage activities, breeds, and physiological changes of these steers were recognized; with cortisol and glucose increasing (P ≤ 0.05) during transportation (4.15±0.46 ng/mL and 5.35±0.46nmol/L respectively) and also with farm group 1 showing higher cortisol (42.62±14.47 ng/mL) than the second group. Furthermore, all steers that were in slaughter group 1 showed less cortisol (101.49±14.47 ng/mL) and glucose (6.50±14.47 nmol/L) levels than those in group 2. In addition, Boran steers had higher packed cell volume, erythrocyte count, and haemoglobin values (33.27±0.54 percent, 7.66±0.19 106 μL, and 11.15±0.16 g/dl respectively) compared to Nguni steers in all production-stages. Later in the experiment, the effect of breed type, production stage activities (farm handling, transportation, and lairage duration), and stress responsiveness on some meat quality parameters (pH, lightness (L*), redness (a*), yellowness (b*), hue, Chroma, thawing and cooking loss, and tenderness) collected from the steers were measured. It was observed that the group lairaged for 16 hours produced the highest L* value (36.25±0.88) compared to those lairaged for 24 hours. As for the b* and hue of the meat, there were positive interactions between the breed type and the production stages (p<0.05). Lastly, cooking loss and tenderness were significantly affected by the breed type in all groups, with Nguni having the most tender meat (24.06±1.39 percent) and less cooking loss (16.92±1.33 percent) than Boran breeds. Therefore, the production stage conditions and breed type influenced some physiological stress-indicators and meat quality of Boran and Nguni steers raised on natural pastures. However, there were not many differences observed between the groups and breeds. , Thesis (MSc) -- Faculty of Science and Agriculture, 2020
- Full Text:
- Date Issued: 2020-01
- Authors: Guzi, Anelisa https://orcid.org/0000-0001-5568-3396
- Date: 2020-01
- Subjects: Boran cattle , Nguni cattle , Cattle breeds
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22721 , vital:52672
- Description: This study's overall objective was to investigate communal farmers' perceptions on production practices and evaluate pre-slaughter responsiveness of extensively reared Boran and Nguni steers. On objective one farmers’ knowledge and perceptions on cattle breeds, management, and marketing channels in selected villages of Alice, Eastern Cape, South Africa were evaluated. Interviews were conducted using a structured questionnaire divided into demographic information and relevant cattle production practices, following a snowball technique to select 101 cattle-keeping households from Gaga, Ntselamanzi, and Ncerha villages. Most of the interviewed cattle farmers were males (65percent), in the age range of 40-60 years, with a primary-matric educational level. Among others, they highlighted financial security (47percent) and traditional ceremonies (26percent) as the reasons for keeping cattle. Most dominant in their herds were the Boran (49percent) and crossbreds (23percent) reared extensively with some supplementation (nutritional and medicinal). Their breed selection was based on disease and tick tolerance, temperament, and product (milk and meat) quality. It was noted that most of the interviewed cattle owners have the basic knowledge of good management practices, breed differences, and marketing chains. They related to low productivity to diseases, lack of knowledge, and poor resources. On the second objective pre-slaughter blood-based stress indicators and their subsequent effects were evaluated on beef quality of extensively reared Nguni and Boran steers . Twenty steers (10 Nguni and 10 Boran) aged 18 months were divided into two groups (with 5 of each breed per group) and transported from the University of Fort Hare Honeydale farm to the East London abattoir in the morning and afternoon trips. Upon arrival at the abattoir, the steers were held in lairage units for 24 hours (group 1) and 16 hours (group 2) until slaughter. Blood samples were drawn using a needle and vacutainer tubes from each steer's jugular vein at the farm before transportation, upon arrival at the abattoir, and during slaughter to perform cortisol, glucose, and routine haematological analysis. M. longissimus dorsi samples were harvested on the left side of each carcass to measure the meat quality attributes. Interactions between the observed production-stage activities, breeds, and physiological changes of these steers were recognized; with cortisol and glucose increasing (P ≤ 0.05) during transportation (4.15±0.46 ng/mL and 5.35±0.46nmol/L respectively) and also with farm group 1 showing higher cortisol (42.62±14.47 ng/mL) than the second group. Furthermore, all steers that were in slaughter group 1 showed less cortisol (101.49±14.47 ng/mL) and glucose (6.50±14.47 nmol/L) levels than those in group 2. In addition, Boran steers had higher packed cell volume, erythrocyte count, and haemoglobin values (33.27±0.54 percent, 7.66±0.19 106 μL, and 11.15±0.16 g/dl respectively) compared to Nguni steers in all production-stages. Later in the experiment, the effect of breed type, production stage activities (farm handling, transportation, and lairage duration), and stress responsiveness on some meat quality parameters (pH, lightness (L*), redness (a*), yellowness (b*), hue, Chroma, thawing and cooking loss, and tenderness) collected from the steers were measured. It was observed that the group lairaged for 16 hours produced the highest L* value (36.25±0.88) compared to those lairaged for 24 hours. As for the b* and hue of the meat, there were positive interactions between the breed type and the production stages (p<0.05). Lastly, cooking loss and tenderness were significantly affected by the breed type in all groups, with Nguni having the most tender meat (24.06±1.39 percent) and less cooking loss (16.92±1.33 percent) than Boran breeds. Therefore, the production stage conditions and breed type influenced some physiological stress-indicators and meat quality of Boran and Nguni steers raised on natural pastures. However, there were not many differences observed between the groups and breeds. , Thesis (MSc) -- Faculty of Science and Agriculture, 2020
- Full Text:
- Date Issued: 2020-01
Development of a Mobile-Based Livestock Breeding Management System for Communal Farmers in Eastern Cape, South Africa
- Authors: Aduradola, Oluwatobi John
- Date: 2021-05
- Subjects: Mobile communication systems , Mobile computing
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20600 , vital:46364
- Description: More than a decade ago, South Africa realized the significance of Information and Communication Technology (ICT) and its use in delivering several services; there are still several challenges that block implementing an ICT-based system to deliver services and information better. Since communal development is still one of the country's biggest concerns, ICT is among several advances and views recognized for speeding up communal development and providing for the country's economic growth. This research aimed to investigate and implement ICT tools for communal farmers in the context of information needs and information dissemination. The research concentrated on the technical tools and skills needed to implement an ICT tool for communal farmers and other stakeholders. A prototyping methodology was used in this research in the development of the required prototype. A study was then conducted to understand the present state and the information needs of communal farmers where the questionnaire was administered. The research results demonstrated the critical need for communal farmers to get information timely at their convenience. A mobile database system was then designed and developed that suits communal farmers' nature. This system was an offline android application that assists with their information need and its dissemination, and it allows the sharing of the communal farmer's data to other stakeholders. , Thesis (MSc) (Computer Science)-- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2021-05
- Authors: Aduradola, Oluwatobi John
- Date: 2021-05
- Subjects: Mobile communication systems , Mobile computing
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20600 , vital:46364
- Description: More than a decade ago, South Africa realized the significance of Information and Communication Technology (ICT) and its use in delivering several services; there are still several challenges that block implementing an ICT-based system to deliver services and information better. Since communal development is still one of the country's biggest concerns, ICT is among several advances and views recognized for speeding up communal development and providing for the country's economic growth. This research aimed to investigate and implement ICT tools for communal farmers in the context of information needs and information dissemination. The research concentrated on the technical tools and skills needed to implement an ICT tool for communal farmers and other stakeholders. A prototyping methodology was used in this research in the development of the required prototype. A study was then conducted to understand the present state and the information needs of communal farmers where the questionnaire was administered. The research results demonstrated the critical need for communal farmers to get information timely at their convenience. A mobile database system was then designed and developed that suits communal farmers' nature. This system was an offline android application that assists with their information need and its dissemination, and it allows the sharing of the communal farmer's data to other stakeholders. , Thesis (MSc) (Computer Science)-- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2021-05
Synthesis and in vitro biological studies of ursolic acid-based hybrid compounds
- Authors: Khwaza, Vuyolwethu
- Date: 2022
- Subjects: Herbal medicine , Herbs -- Therapeutic use , Antineoplastic antibiotics
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/27797 , vital:69689
- Description: Ursolic acid UA, a pentacyclic triterpenoid that is commonly found in many medicinal herbs and fruits, has been identified as a potential source of therapeutic agents because of its potent biological effects, which include its potential anticancer and antimicrobial activities. However, its limited solubility, rapid metabolism and poor bioavailability inhibit its clinical applications. Numerous UA derivatives have been prepared over the past years in an effort to mitigate the drawbacks associated with UA, as new chemical entities for the treatment of various infections. There is very little progress in the discovery of efficient UA derivatives. In this study, a class of ester and amide-linked ursolic acid-based hybrid compounds fused with selected pharmaceutical scaffolds were successfully synthesized using amidation and esterification reactions and tested for antibacterial and cytotoxicity activities. Hybridizing UA with other known pharmaceutical scaffolds has the potential of overcoming its drawbacks. FT-IR, Mass Spectroscopy, and 1H13C-NMR spectroscopy were used to confirm the structures of the synthesized hybrid compounds. Among the tested ester-linked hybrid compounds in Chapter three, compounds 3.14-3.19,3.21, 3.34, 3.31, and 3.30 demonstrated significant antibacterial activities against some tested bacteria, with MIC values of 15.625 μgml. Furthermore, the in vitro cytotoxicity of these hybrids was determined using the MTT assay against three human tumor cell lines MCF7, MDA-MB-231, and HeLa cells. Compounds 3.19 and 3.34 were found to have better cytotoxic activity when compared to ursolic acid, with IC50 values of 46.99 and 48.18 μg ml respectively. Both compounds revealed more promising docking results, presenting favourable binding interactions as well as better docking energy against the MCF 7 protein target compared to the parent compound ursolic acid. In Chapter Four, among the tested amide-linked hybrid compounds, Compounds 4.17 and 4.24 demonstrated significant antibacterial activity against the majority of bacterial strains with MIC values of 15.625 gml. Compound 4.24 exhibited a MIC value of 15.625gmL against BS, SA, PV, KO, PM, and EC. Compound 4.23 was more cytotoxic to HeLa cells than ursolic acid. Furthermore, molecular docking calculations revealed that compound 4.16 strongly binds to the protein epidermal growth factor receptor while e compounds 4.17 and 4.24 showed a strong binding affinity for the methionyl-tRNA synthetase. In both cases, the hybrid compounds showed better conformational fittings in the active site of the targeted proteins as compared to the parent ursolic acid. , Thesis (MSc) -- Faculty of Science and Agriculture, 2022
- Full Text:
- Date Issued: 2022
- Authors: Khwaza, Vuyolwethu
- Date: 2022
- Subjects: Herbal medicine , Herbs -- Therapeutic use , Antineoplastic antibiotics
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/27797 , vital:69689
- Description: Ursolic acid UA, a pentacyclic triterpenoid that is commonly found in many medicinal herbs and fruits, has been identified as a potential source of therapeutic agents because of its potent biological effects, which include its potential anticancer and antimicrobial activities. However, its limited solubility, rapid metabolism and poor bioavailability inhibit its clinical applications. Numerous UA derivatives have been prepared over the past years in an effort to mitigate the drawbacks associated with UA, as new chemical entities for the treatment of various infections. There is very little progress in the discovery of efficient UA derivatives. In this study, a class of ester and amide-linked ursolic acid-based hybrid compounds fused with selected pharmaceutical scaffolds were successfully synthesized using amidation and esterification reactions and tested for antibacterial and cytotoxicity activities. Hybridizing UA with other known pharmaceutical scaffolds has the potential of overcoming its drawbacks. FT-IR, Mass Spectroscopy, and 1H13C-NMR spectroscopy were used to confirm the structures of the synthesized hybrid compounds. Among the tested ester-linked hybrid compounds in Chapter three, compounds 3.14-3.19,3.21, 3.34, 3.31, and 3.30 demonstrated significant antibacterial activities against some tested bacteria, with MIC values of 15.625 μgml. Furthermore, the in vitro cytotoxicity of these hybrids was determined using the MTT assay against three human tumor cell lines MCF7, MDA-MB-231, and HeLa cells. Compounds 3.19 and 3.34 were found to have better cytotoxic activity when compared to ursolic acid, with IC50 values of 46.99 and 48.18 μg ml respectively. Both compounds revealed more promising docking results, presenting favourable binding interactions as well as better docking energy against the MCF 7 protein target compared to the parent compound ursolic acid. In Chapter Four, among the tested amide-linked hybrid compounds, Compounds 4.17 and 4.24 demonstrated significant antibacterial activity against the majority of bacterial strains with MIC values of 15.625 gml. Compound 4.24 exhibited a MIC value of 15.625gmL against BS, SA, PV, KO, PM, and EC. Compound 4.23 was more cytotoxic to HeLa cells than ursolic acid. Furthermore, molecular docking calculations revealed that compound 4.16 strongly binds to the protein epidermal growth factor receptor while e compounds 4.17 and 4.24 showed a strong binding affinity for the methionyl-tRNA synthetase. In both cases, the hybrid compounds showed better conformational fittings in the active site of the targeted proteins as compared to the parent ursolic acid. , Thesis (MSc) -- Faculty of Science and Agriculture, 2022
- Full Text:
- Date Issued: 2022