The maturity of project management in engineering consulting firms
- Authors: Machite, Kennedy
- Date: 2016
- Subjects: Project management Consulting engineers -- South Africa , Engineering firms -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/18409 , vital:28634
- Description: With a considerable number of built environment projects not being completed successfully, this study was undertaken to investigate how effectively consulting engineering firms are applying project management principles in the way they manage projects. This was achieved by measuring the project management maturity levels of consulting engineering firms. Maturity levels were measured for each of the ten knowledge areas of the Project Management Institute’s Project Management Body of Knowledge to determine areas where consulting engineering firms perform below expectation and as a result determine probable causes of project failures. The maturity of the firm was then calculated as the average of the maturity for the knowledge areas. The study found that consulting engineering firms have higher levels of project management maturity than the average for the construction and civil engineering sector. Apart from risk and procurement management, all the other knowledge areas have higher maturity levels than the corresponding construction and civil engineering knowledge areas. Although the overall maturity results indicate that the larger firms are more mature in their project management practices than the smaller firms, the individual knowledge areas are inconsistent. The study reveals that consulting engineering firms are weakest in the risk management, human resources and stakeholder management knowledge areas. There is limited literature available on the status of project management, project management methodologies, and performance of consulting projects in the engineering environment (Labuschagne & Steyn, 2010:70). There is need for future studies to establish a methodology developed specifically for the Consulting Engineering Firms in line with what Labuschagne & Steyn (2010) started and a Project Management Maturity Model specific to the Consulting Engineering Industry.
- Full Text:
- Date Issued: 2016
- Authors: Machite, Kennedy
- Date: 2016
- Subjects: Project management Consulting engineers -- South Africa , Engineering firms -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/18409 , vital:28634
- Description: With a considerable number of built environment projects not being completed successfully, this study was undertaken to investigate how effectively consulting engineering firms are applying project management principles in the way they manage projects. This was achieved by measuring the project management maturity levels of consulting engineering firms. Maturity levels were measured for each of the ten knowledge areas of the Project Management Institute’s Project Management Body of Knowledge to determine areas where consulting engineering firms perform below expectation and as a result determine probable causes of project failures. The maturity of the firm was then calculated as the average of the maturity for the knowledge areas. The study found that consulting engineering firms have higher levels of project management maturity than the average for the construction and civil engineering sector. Apart from risk and procurement management, all the other knowledge areas have higher maturity levels than the corresponding construction and civil engineering knowledge areas. Although the overall maturity results indicate that the larger firms are more mature in their project management practices than the smaller firms, the individual knowledge areas are inconsistent. The study reveals that consulting engineering firms are weakest in the risk management, human resources and stakeholder management knowledge areas. There is limited literature available on the status of project management, project management methodologies, and performance of consulting projects in the engineering environment (Labuschagne & Steyn, 2010:70). There is need for future studies to establish a methodology developed specifically for the Consulting Engineering Firms in line with what Labuschagne & Steyn (2010) started and a Project Management Maturity Model specific to the Consulting Engineering Industry.
- Full Text:
- Date Issued: 2016
Synthesis and characterisation of lanthanide complexes with nitrogen- and oxygen-donor ligands
- Authors: Madanhire, Tatenda
- Date: 2016
- Subjects: Rare earth metals
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/13127 , vital:27154
- Description: The reactions of Ln(NO3)3∙6H2O (Ln = Pr, Nd or Er) with the potentially tridentate O,N,O chelating ligand 2,6-pyridinedimethanol (H2pydm) were investigated, and complexes with the formula, [Ln(H2pydm)2(NO3)2](NO3) (Ln = Pr or Nd) and [Er(H2pydm)3](NO3)3 were isolated. The ten-coordinate Pr(III) and Nd(III) compounds crystallise in the triclinic space group P-1 while the nine-coordinate Er(III) complex crystallises in the monoclinic system (P21/n). The reaction of PrCl3∙6H2O with H2pydm yielded the compound, [Pr(H2pydm)3](Cl)3, that crystallises in the monoclinic system, space group P21/c with α = 90, β = 98.680(1) and γ = 90°. The nine-coordinate Pr(III) ion is bound to three H2pydm ligands, with bond distances Pr-O 2.455(2)-2.478(2) Å and Pr-N 2.6355(19)-2.64(2) Å. X-ray crystal structures of all the H2pydm complexes reveal that the ligand coordinates tridentately, via the pyridyl nitrogen atom and the two hydroxyl oxygen atoms. The electronic absorption spectra of complexes show 4f-4f transitions. Rare-earth complexes, [Ln(H2L1)2(NO3)3] [Ln = Gd, Ho or Nd], were also prepared from a Schiff base. The X-ray single-crystal diffraction studies and SHAPE analyses of the Gd(III) and Ho(III) complexes shows that the complexes are ten-coordinate and exhibit distorted tetradecahedron geometries. With proton migration occurring from the phenol group to the imine function, complexation of the lanthanides to the ligand gives the ligand a zwitterionic phenoxo-iminium form. A phenolate oxygen-bridged dinuclear complex, [Ce2(H2L1)(ovan)3(NO3)3], has been obtained by reacting Ce(NO3)3∙6H2O with an o-vanillin derived Schiff base ligand, 2-((E)-(1-hydroxy-2-methylpropan-2-ylimino)methyl)-6-methoxyphenol (H2L1). Hydrolysis of the Schiff base occurred to yield o-vanillin, which bridged two cerium atoms with the Ce∙∙∙Ce distance equal to 3.823 Å. The Ce(III) ions are both tencoordinate, but have different coordination environments, showing tetradecahedron and staggered dodecahedron geometries, respectively. The reaction of salicylaldehyde-N(4)-diethylthiosemicarbazone (H2L2) in the presence of hydrated Ln(III) nitrates led to the isolation of two novel compounds: (E)-2[(ortho-hydroxy)benzylidene]-2-(thiomethyl)-thionohydrazide (1) and bis[2,3-diaza4-(2-hydroxyphenyl)-1-thiomethyl-buta-1,3-diene]disulfide. The latter is a dimer of the former. For this asymmetric Schiff base, 1 and the symmetric disulfide, classical hydrogen bonds of the O–H∙∙∙N as well as N–H∙∙∙S (for 1) type are apparent next to C–H∙∙∙O contacts. 4-(4-Bromophenyl)-1-(propan-2-ylidene)thiosemicarbazide was also prepared upon reacting 4-(4-bromophenyl)-3-thiosemicarbazide with acetone in the presence of ethanol and La(NO3)3∙6H2O. The C=S bond length was found to be 1.6686(16) Å which is in good agreement with other thioketones whose metrical parameters have been deposited with the Cambridge Structural Database. Classical hydrogen bonds of the N–H∙∙∙N and the N–H∙∙∙Br type are observed next to C–H∙∙∙S contacts. All synthesised compounds were characterised by microanalyses, single-crystal X-ray diffraction (except for [Nd(H2L1)2(NO3)3]), 1H NMR and IR spectroscopy.
- Full Text:
- Date Issued: 2016
- Authors: Madanhire, Tatenda
- Date: 2016
- Subjects: Rare earth metals
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/13127 , vital:27154
- Description: The reactions of Ln(NO3)3∙6H2O (Ln = Pr, Nd or Er) with the potentially tridentate O,N,O chelating ligand 2,6-pyridinedimethanol (H2pydm) were investigated, and complexes with the formula, [Ln(H2pydm)2(NO3)2](NO3) (Ln = Pr or Nd) and [Er(H2pydm)3](NO3)3 were isolated. The ten-coordinate Pr(III) and Nd(III) compounds crystallise in the triclinic space group P-1 while the nine-coordinate Er(III) complex crystallises in the monoclinic system (P21/n). The reaction of PrCl3∙6H2O with H2pydm yielded the compound, [Pr(H2pydm)3](Cl)3, that crystallises in the monoclinic system, space group P21/c with α = 90, β = 98.680(1) and γ = 90°. The nine-coordinate Pr(III) ion is bound to three H2pydm ligands, with bond distances Pr-O 2.455(2)-2.478(2) Å and Pr-N 2.6355(19)-2.64(2) Å. X-ray crystal structures of all the H2pydm complexes reveal that the ligand coordinates tridentately, via the pyridyl nitrogen atom and the two hydroxyl oxygen atoms. The electronic absorption spectra of complexes show 4f-4f transitions. Rare-earth complexes, [Ln(H2L1)2(NO3)3] [Ln = Gd, Ho or Nd], were also prepared from a Schiff base. The X-ray single-crystal diffraction studies and SHAPE analyses of the Gd(III) and Ho(III) complexes shows that the complexes are ten-coordinate and exhibit distorted tetradecahedron geometries. With proton migration occurring from the phenol group to the imine function, complexation of the lanthanides to the ligand gives the ligand a zwitterionic phenoxo-iminium form. A phenolate oxygen-bridged dinuclear complex, [Ce2(H2L1)(ovan)3(NO3)3], has been obtained by reacting Ce(NO3)3∙6H2O with an o-vanillin derived Schiff base ligand, 2-((E)-(1-hydroxy-2-methylpropan-2-ylimino)methyl)-6-methoxyphenol (H2L1). Hydrolysis of the Schiff base occurred to yield o-vanillin, which bridged two cerium atoms with the Ce∙∙∙Ce distance equal to 3.823 Å. The Ce(III) ions are both tencoordinate, but have different coordination environments, showing tetradecahedron and staggered dodecahedron geometries, respectively. The reaction of salicylaldehyde-N(4)-diethylthiosemicarbazone (H2L2) in the presence of hydrated Ln(III) nitrates led to the isolation of two novel compounds: (E)-2[(ortho-hydroxy)benzylidene]-2-(thiomethyl)-thionohydrazide (1) and bis[2,3-diaza4-(2-hydroxyphenyl)-1-thiomethyl-buta-1,3-diene]disulfide. The latter is a dimer of the former. For this asymmetric Schiff base, 1 and the symmetric disulfide, classical hydrogen bonds of the O–H∙∙∙N as well as N–H∙∙∙S (for 1) type are apparent next to C–H∙∙∙O contacts. 4-(4-Bromophenyl)-1-(propan-2-ylidene)thiosemicarbazide was also prepared upon reacting 4-(4-bromophenyl)-3-thiosemicarbazide with acetone in the presence of ethanol and La(NO3)3∙6H2O. The C=S bond length was found to be 1.6686(16) Å which is in good agreement with other thioketones whose metrical parameters have been deposited with the Cambridge Structural Database. Classical hydrogen bonds of the N–H∙∙∙N and the N–H∙∙∙Br type are observed next to C–H∙∙∙S contacts. All synthesised compounds were characterised by microanalyses, single-crystal X-ray diffraction (except for [Nd(H2L1)2(NO3)3]), 1H NMR and IR spectroscopy.
- Full Text:
- Date Issued: 2016
Technical and institutional constraints faced by vegetable co-operatives in the Buffalo City Metropolitan Municipality in Eastern Cape Province, South Africa
- Authors: Madlodlo, Sinazo
- Date: 2016
- Subjects: Agriculture, Cooperative -- South Africa -- Eastern Cape , Vegetable trade -- South Africa -- Eastern Cape , Cooperative marketing of farm produce -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/1497 , vital:27396
- Description: This study focused on the technical and institutional constraints faced by the vegetable co-operatives with regard to the impact on productivity. Vegetable co-operatives have no access to markets due to their poor performance on productivity and poor quality produce resulting to low prices for the produce such that they cannot compete in a market economy. In this study, the data was drawn from a sample of thirty vegetable co-operatives in the Buffalo City Metropolitan Municipality (BCMM) of the Eastern Cape; obtained through focus group discussions and interviews from each cooperative. The objectives of the study are to measure the productivity of vegetable co-operatives using Total factor productivity analysis (TFP) and profitability of vegetable co-operative using Gross Margin (GM). Followed by the descriptive statistics in identifying and assessing the socio-economic characteristics as well as coping strategies adopted by vegetable co-operatives in BCMM where percentages, means and tables are used looking at the highest frequency. The results show that the vegetable co-operatives in the BCMM are not productive and profitable due to major constraints experienced by co-operatives such as lack of market, information, trainings and business skills, capital, infrastructural facilities, effective extension services that all leads to poor produce quality. Co-operative is said to be profitable and viable if total revenue is greater than the total variable cost which makes the gross margin positive. In this case, the total gross margin is negative. The results showed that the production costs, maintenance (tractor hire, generator hire and servicing) and electricity costs were the major costs incurred in the production of vegetable by the co-operatives.
- Full Text:
- Date Issued: 2016
- Authors: Madlodlo, Sinazo
- Date: 2016
- Subjects: Agriculture, Cooperative -- South Africa -- Eastern Cape , Vegetable trade -- South Africa -- Eastern Cape , Cooperative marketing of farm produce -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/1497 , vital:27396
- Description: This study focused on the technical and institutional constraints faced by the vegetable co-operatives with regard to the impact on productivity. Vegetable co-operatives have no access to markets due to their poor performance on productivity and poor quality produce resulting to low prices for the produce such that they cannot compete in a market economy. In this study, the data was drawn from a sample of thirty vegetable co-operatives in the Buffalo City Metropolitan Municipality (BCMM) of the Eastern Cape; obtained through focus group discussions and interviews from each cooperative. The objectives of the study are to measure the productivity of vegetable co-operatives using Total factor productivity analysis (TFP) and profitability of vegetable co-operative using Gross Margin (GM). Followed by the descriptive statistics in identifying and assessing the socio-economic characteristics as well as coping strategies adopted by vegetable co-operatives in BCMM where percentages, means and tables are used looking at the highest frequency. The results show that the vegetable co-operatives in the BCMM are not productive and profitable due to major constraints experienced by co-operatives such as lack of market, information, trainings and business skills, capital, infrastructural facilities, effective extension services that all leads to poor produce quality. Co-operative is said to be profitable and viable if total revenue is greater than the total variable cost which makes the gross margin positive. In this case, the total gross margin is negative. The results showed that the production costs, maintenance (tractor hire, generator hire and servicing) and electricity costs were the major costs incurred in the production of vegetable by the co-operatives.
- Full Text:
- Date Issued: 2016
Impact of smallholder irrigation schemes on rural livelihoods of farmers in the Eastern Cape Province of South Africa: the case of Melani Irrigation Scheme
- Authors: Magqibelo, Sinovuyo
- Date: 2016
- Subjects: Irrigation farming -- Economic aspects Irrigation -- South Africa -- Eastern Cape Farms, Small -- South Africa -- Eastern Cape , Rural development -- South Africa -- Eastern Cape Agriculture -- Economic aspects -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/1774 , vital:27557
- Description: Irrigation farming is one of the most important rural development investments that can have both direct and indirect impacts on poverty and food security. The irregular and unreliable rainfall in the Eastern Cape Province has caused the smallholder farmers to deepen the irrigation farming systems as a strategy to cope with food shortage, income and poverty. South Africa has invested substantially in smallholder irrigation to benefit smallholder farmers in the less developed areas. Although the investment on small scale irrigation was to improve the welfare of the people, the performance and welfare impact of smallholder irrigation schemes has been poor and fall far short of the expectations of many stakeholders. The broad objective of the study was to examine the contribution of smallholder irrigation scheme on rural livelihoods of smallholder farmers at the project area. The null hypothesis was that smallholder irrigation schemes have no impact on farmer’s livelihoods. The alternative hypothesis for this study was that Melani irrigation scheme is contributing in improving rural livelihoods of smallholder farmers in the area. Cross study research design was used in the methodology. The purposive sampling was applied in order to choose a sample of 107 respondents that were interviewed using questionnaires, including both irrigating and non-irrigating farmers. A multiple linear regression analysis was used to find out whether the performance of the two groups of farmers is different and to what extent. To determine the specific role of irrigation an Independent T-Test was ran. Out of the selected sample 68 percent of households were farmers, 7.5 percent informal employed and 27 percent unemployed. It was found that the majority of participants were males and were uneducated. They depended on social grants for a living. The findings from the study showed that 84 percent of the respondents agreed that there is no market available in the village and farmers had limited access to credits. The crop income was the most contributing factor to household income. The results showed that whether the farmer is a non-irrigator or an irrigator the performance is not significant. Irrigation scheme improvement attained by smallholder farmers need to be maintained.
- Full Text:
- Date Issued: 2016
- Authors: Magqibelo, Sinovuyo
- Date: 2016
- Subjects: Irrigation farming -- Economic aspects Irrigation -- South Africa -- Eastern Cape Farms, Small -- South Africa -- Eastern Cape , Rural development -- South Africa -- Eastern Cape Agriculture -- Economic aspects -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/1774 , vital:27557
- Description: Irrigation farming is one of the most important rural development investments that can have both direct and indirect impacts on poverty and food security. The irregular and unreliable rainfall in the Eastern Cape Province has caused the smallholder farmers to deepen the irrigation farming systems as a strategy to cope with food shortage, income and poverty. South Africa has invested substantially in smallholder irrigation to benefit smallholder farmers in the less developed areas. Although the investment on small scale irrigation was to improve the welfare of the people, the performance and welfare impact of smallholder irrigation schemes has been poor and fall far short of the expectations of many stakeholders. The broad objective of the study was to examine the contribution of smallholder irrigation scheme on rural livelihoods of smallholder farmers at the project area. The null hypothesis was that smallholder irrigation schemes have no impact on farmer’s livelihoods. The alternative hypothesis for this study was that Melani irrigation scheme is contributing in improving rural livelihoods of smallholder farmers in the area. Cross study research design was used in the methodology. The purposive sampling was applied in order to choose a sample of 107 respondents that were interviewed using questionnaires, including both irrigating and non-irrigating farmers. A multiple linear regression analysis was used to find out whether the performance of the two groups of farmers is different and to what extent. To determine the specific role of irrigation an Independent T-Test was ran. Out of the selected sample 68 percent of households were farmers, 7.5 percent informal employed and 27 percent unemployed. It was found that the majority of participants were males and were uneducated. They depended on social grants for a living. The findings from the study showed that 84 percent of the respondents agreed that there is no market available in the village and farmers had limited access to credits. The crop income was the most contributing factor to household income. The results showed that whether the farmer is a non-irrigator or an irrigator the performance is not significant. Irrigation scheme improvement attained by smallholder farmers need to be maintained.
- Full Text:
- Date Issued: 2016
Wavelength-modulation spectroscopy for the evaluation of the photoresponse of solar cells
- Mandanirina, Nambinintsoa Roméoh Hasinjatovo
- Authors: Mandanirina, Nambinintsoa Roméoh Hasinjatovo
- Date: 2016
- Subjects: Gallium arsenide semiconductors , Solar cells , Modulation spectroscopy
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/7244 , vital:21312
- Description: This study describes the development of a wavelength-modulation spectroscopy technique for the evaluation of solar cell devices. In particular, the technique is used to investigate the sub-bandgap response associated with the incorporation of GaSb quantum rings into the active region of a conventional GaAs p-i-n solar cell. These GaSb/GaAs quantum ring solar cells are a class of third generation cells, with the potential to exceed the Shockley-Queisser efficiency limit of single junction devices. Wavelength-modulation spectroscopy (WMS) techniques involve the modulation of the wavelength of a pseudo-monochromatic light source, with the resulting variation in the measured photocurrent then being a measure of the differential optical response of the solar cell. Although the conventional photocurrent spectrum of a solar cell is a good measure of the optical response characteristics, the differential technique gives supplemental detail related to the absorption spectrum. In addition to the basic WMS setup, we also developed an in situ flux correction module to ensure that a constant excitation intensity is maintained during the wavelength modulation. The excitation source inherently has a spectral dependence that leads to an undesirable contribution to the photocurrent signal. The operation of the flux corrected WMS setup has been demonstrated by photocurrent and photo-capacitance response measurements to obtain the differential quantum efficiency and charging characteristics of the quantum ring solar cells.
- Full Text:
- Date Issued: 2016
- Authors: Mandanirina, Nambinintsoa Roméoh Hasinjatovo
- Date: 2016
- Subjects: Gallium arsenide semiconductors , Solar cells , Modulation spectroscopy
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/7244 , vital:21312
- Description: This study describes the development of a wavelength-modulation spectroscopy technique for the evaluation of solar cell devices. In particular, the technique is used to investigate the sub-bandgap response associated with the incorporation of GaSb quantum rings into the active region of a conventional GaAs p-i-n solar cell. These GaSb/GaAs quantum ring solar cells are a class of third generation cells, with the potential to exceed the Shockley-Queisser efficiency limit of single junction devices. Wavelength-modulation spectroscopy (WMS) techniques involve the modulation of the wavelength of a pseudo-monochromatic light source, with the resulting variation in the measured photocurrent then being a measure of the differential optical response of the solar cell. Although the conventional photocurrent spectrum of a solar cell is a good measure of the optical response characteristics, the differential technique gives supplemental detail related to the absorption spectrum. In addition to the basic WMS setup, we also developed an in situ flux correction module to ensure that a constant excitation intensity is maintained during the wavelength modulation. The excitation source inherently has a spectral dependence that leads to an undesirable contribution to the photocurrent signal. The operation of the flux corrected WMS setup has been demonstrated by photocurrent and photo-capacitance response measurements to obtain the differential quantum efficiency and charging characteristics of the quantum ring solar cells.
- Full Text:
- Date Issued: 2016
Quantitative microstructural evaluation of 12 Cr creep aged steels after welding
- Marx, Genevéve, Neethling, Jan
- Authors: Marx, Genevéve , Neethling, Jan
- Date: 2016
- Subjects: Stainless steel -- Welding , Electron microscopy
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/7232 , vital:21307
- Description: This dissertation focuses on the quantitative microstructural evaluation of new and creep aged X20 (12 Cr) stainless steel after welding. X20 stainless steel has been widely used in the high temperature and pressure pipework of coal-fired power plants. Consequently, this material has to withstand extreme conditions of high temperature and stress during service exposure. Under these conditions, creep deteriorates the strength of the material. The material’s resistance to creep damage due to its microstructure can be quantitatively described by the back-stress. There are four microstructural contributions to the back-stress: Precipitate Hardening, Sub-Boundary Hardening, Solid-Solution Hardening and Dislocation Hardening. Fusion welding is performed on creep aged materials when a component needs to be replaced. This high temperature process results in the formation of different microstructural regions within the weldment. These creep damaged components have a weldability limit as set by the life management strategy of the power plant company. Measuring techniques capable of quantifying the microstructural contributions (precipitates, subgrains and dislocations) were developed and evaluated in this study. These techniques were then used to characterise the different microstructural regions within a new and creep aged X20 steel weldment. Differences in the microstructure of the new and creep aged X20 steel was illustrated by the results of this study. The measured size and number densities of the precipitates in the creep aged X20 material showed that there is a decrease in PH during creep exposure. There was a decrease in SBH and DH stress for the creep aged X20 material due to coarsening of the subgrains and annealing of dislocations during creep exposure. The quantitative techniques demonstrated in this study opens up the possibility to perform life assessment on weldments with inhomogeneous microstructures by following a microstructural based approach.
- Full Text:
- Date Issued: 2016
- Authors: Marx, Genevéve , Neethling, Jan
- Date: 2016
- Subjects: Stainless steel -- Welding , Electron microscopy
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/7232 , vital:21307
- Description: This dissertation focuses on the quantitative microstructural evaluation of new and creep aged X20 (12 Cr) stainless steel after welding. X20 stainless steel has been widely used in the high temperature and pressure pipework of coal-fired power plants. Consequently, this material has to withstand extreme conditions of high temperature and stress during service exposure. Under these conditions, creep deteriorates the strength of the material. The material’s resistance to creep damage due to its microstructure can be quantitatively described by the back-stress. There are four microstructural contributions to the back-stress: Precipitate Hardening, Sub-Boundary Hardening, Solid-Solution Hardening and Dislocation Hardening. Fusion welding is performed on creep aged materials when a component needs to be replaced. This high temperature process results in the formation of different microstructural regions within the weldment. These creep damaged components have a weldability limit as set by the life management strategy of the power plant company. Measuring techniques capable of quantifying the microstructural contributions (precipitates, subgrains and dislocations) were developed and evaluated in this study. These techniques were then used to characterise the different microstructural regions within a new and creep aged X20 steel weldment. Differences in the microstructure of the new and creep aged X20 steel was illustrated by the results of this study. The measured size and number densities of the precipitates in the creep aged X20 material showed that there is a decrease in PH during creep exposure. There was a decrease in SBH and DH stress for the creep aged X20 material due to coarsening of the subgrains and annealing of dislocations during creep exposure. The quantitative techniques demonstrated in this study opens up the possibility to perform life assessment on weldments with inhomogeneous microstructures by following a microstructural based approach.
- Full Text:
- Date Issued: 2016
The consumption and use of wild foods by children across a deforestation gradient in Zomba District, Malawi
- Authors: Maseko, Heather Nonhlanhla
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/3212 , vital:20392
- Description: Despite consensus on their significant nutritional value, wild foods are continually excluded from both food security statistics and economic values of natural resources. Though largely unexplored, there is evidence on the use of wild foods by children to supplement their diets and as a source of income. Children have knowledge on the gathering and hunting of selected wild food species and sources thereof. Wetlands, agro-ecosystems, natural forests, human landscapes and river systems remain important sources of wild food resources. The provision of and access to these resources are significantly affected by the interference and disruption to natural ecosystems. In Malawi, interference has been largely due to deforestation and land use change caused by an interplay of pressures from population growth for development and agricultural expansion. Against this background, the implications of deforestation and vegetation cover on the availability of wild foods and their access and use by children is largely unexplored. Through a comprehensive analysis of data collected from 150 children and 50 elderly men and women, the integration of Participatory Rural Appraisal (PRA) exercises and Geographic Information System (GIS), in the four sites of Mpheta, Mtuluma, Kasonga and Makombe in Zomba district, wild foods availability was established and their contribution to the nutritional status of children and households’ food security assessed. Study sites were identified along the deforestation gradient of Lake Chilwa, Zomba Mountain and Shire River basin with an additional focus on varying landscapes. One hundred and twenty species of wild foods were identified with greatest availability in areas of high vegetation cover and the lowest in areas of low vegetation cover, but with meaningful differences per wild food category. There was considerable reduction in the availability of wild foods with increasing deforestation; mainly wild game and fruits species and, in turn, decreased access of these by children. Nevertheless, small game, insects, other wild fruits and wild vegetables thrive well in agro-ecosystems and therefore were minimally affected by deforestation but largely by management practices of those systems and can be possibly improved through the promotion of agro-ecological farming systems. The research reveals that wild foods form an important component of the starch based diets of households from agricultural communities in the various landscapes. Besides securing the household’s food base, all children largely supplemented their diets with wild foods but with increased dependence by children from poorer households who are highly vulnerable to food insecurity. Access and use of wild foods was largely dependent on children’s knowledge, perceptions of the wild food and ease of access, with considerable variations due to gender and socio-cultural norms. Besides contributing to the nutritional status and food security, commercialisation of wild foods was common among children, hence providing them with an alternative livelihood strategy and in some cases only viable source of income.
- Full Text:
- Date Issued: 2016
- Authors: Maseko, Heather Nonhlanhla
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/3212 , vital:20392
- Description: Despite consensus on their significant nutritional value, wild foods are continually excluded from both food security statistics and economic values of natural resources. Though largely unexplored, there is evidence on the use of wild foods by children to supplement their diets and as a source of income. Children have knowledge on the gathering and hunting of selected wild food species and sources thereof. Wetlands, agro-ecosystems, natural forests, human landscapes and river systems remain important sources of wild food resources. The provision of and access to these resources are significantly affected by the interference and disruption to natural ecosystems. In Malawi, interference has been largely due to deforestation and land use change caused by an interplay of pressures from population growth for development and agricultural expansion. Against this background, the implications of deforestation and vegetation cover on the availability of wild foods and their access and use by children is largely unexplored. Through a comprehensive analysis of data collected from 150 children and 50 elderly men and women, the integration of Participatory Rural Appraisal (PRA) exercises and Geographic Information System (GIS), in the four sites of Mpheta, Mtuluma, Kasonga and Makombe in Zomba district, wild foods availability was established and their contribution to the nutritional status of children and households’ food security assessed. Study sites were identified along the deforestation gradient of Lake Chilwa, Zomba Mountain and Shire River basin with an additional focus on varying landscapes. One hundred and twenty species of wild foods were identified with greatest availability in areas of high vegetation cover and the lowest in areas of low vegetation cover, but with meaningful differences per wild food category. There was considerable reduction in the availability of wild foods with increasing deforestation; mainly wild game and fruits species and, in turn, decreased access of these by children. Nevertheless, small game, insects, other wild fruits and wild vegetables thrive well in agro-ecosystems and therefore were minimally affected by deforestation but largely by management practices of those systems and can be possibly improved through the promotion of agro-ecological farming systems. The research reveals that wild foods form an important component of the starch based diets of households from agricultural communities in the various landscapes. Besides securing the household’s food base, all children largely supplemented their diets with wild foods but with increased dependence by children from poorer households who are highly vulnerable to food insecurity. Access and use of wild foods was largely dependent on children’s knowledge, perceptions of the wild food and ease of access, with considerable variations due to gender and socio-cultural norms. Besides contributing to the nutritional status and food security, commercialisation of wild foods was common among children, hence providing them with an alternative livelihood strategy and in some cases only viable source of income.
- Full Text:
- Date Issued: 2016
Crop yields from organic and conventional farming systems in South Africa's Southern Cape
- Authors: Mashele, N'wa-Jama
- Date: 2016
- Subjects: Organic farming -- South Africa Sustainable agriculture -- South Africa Agricultural systems -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/11637 , vital:26946
- Description: South Africa (SA) is food secure on a national level, however citizens in rural and marginalised areas face household food insecurity due to lack of access to this food. South Africa has low fertility soils and scarce water resources. Climate change reports of unpredictable weather conditions will further exacerbate these challenges. The majority of the agricultural production methods in SA are industrialised and rely heavily on external inputs. Alternative agricultural production methods which are environmentally less taxing, are affordable and yield nutritious food, need to be investigated and adopted. A long-term trial investigating the differences in yields between conventional and organic farming systems was established at the NMMU George Saasveld campus. A baseline study preceded the cropping seasons to establish pre-treatment soil conditions before the two farming systems were be implemented. The trial was a randomized complete block design split into organic, conventional and control plots. In the first cropping season (summer) three crops cabbage (Brassica oleracea var. capitata), sweet potato (Ipomea batatas) and cowpea (vigna ungucuilata) were planted under the different treatments. Soil fertility changes after application of chemical and organic fertilizer were measured. Soil pH and phosphorus increased whilst potassium and soil carbon decreased from baseline levels. The organic plots were found to have higher soil pH, potassium and carbon, whilst P was higher in the conventional plots. The organic cabbages had a yield 12% lower than conventional cabbages, organic cowpeas were 51% lower than conventional cowpeas. Baboons damaged sweet potato plots before maturity. Broccoli (Brassica oleracea var. italica), radish (Raphanus sativa) and green pea (Pisum sativum) were planted in the second cropping season (winter). Organic broccoli yields were 51% lower than conventional broccoli, organic green peas were 18 % lower than conventional green peas. The organic radish yields were 36% lower than conventional yields and this was statically significant. The yield differences were statically significant between control and conventional cabbages (25%) and broccolis (68%). The results indicate that there is on average an initial 25% yield difference between organic and conventional farming systems. Similar studies have shown that the yield gap can be reduced within three to four years. This study presents preliminary results of trials that are to continue for ten years, during which time the yield differences may vary.
- Full Text:
- Date Issued: 2016
- Authors: Mashele, N'wa-Jama
- Date: 2016
- Subjects: Organic farming -- South Africa Sustainable agriculture -- South Africa Agricultural systems -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/11637 , vital:26946
- Description: South Africa (SA) is food secure on a national level, however citizens in rural and marginalised areas face household food insecurity due to lack of access to this food. South Africa has low fertility soils and scarce water resources. Climate change reports of unpredictable weather conditions will further exacerbate these challenges. The majority of the agricultural production methods in SA are industrialised and rely heavily on external inputs. Alternative agricultural production methods which are environmentally less taxing, are affordable and yield nutritious food, need to be investigated and adopted. A long-term trial investigating the differences in yields between conventional and organic farming systems was established at the NMMU George Saasveld campus. A baseline study preceded the cropping seasons to establish pre-treatment soil conditions before the two farming systems were be implemented. The trial was a randomized complete block design split into organic, conventional and control plots. In the first cropping season (summer) three crops cabbage (Brassica oleracea var. capitata), sweet potato (Ipomea batatas) and cowpea (vigna ungucuilata) were planted under the different treatments. Soil fertility changes after application of chemical and organic fertilizer were measured. Soil pH and phosphorus increased whilst potassium and soil carbon decreased from baseline levels. The organic plots were found to have higher soil pH, potassium and carbon, whilst P was higher in the conventional plots. The organic cabbages had a yield 12% lower than conventional cabbages, organic cowpeas were 51% lower than conventional cowpeas. Baboons damaged sweet potato plots before maturity. Broccoli (Brassica oleracea var. italica), radish (Raphanus sativa) and green pea (Pisum sativum) were planted in the second cropping season (winter). Organic broccoli yields were 51% lower than conventional broccoli, organic green peas were 18 % lower than conventional green peas. The organic radish yields were 36% lower than conventional yields and this was statically significant. The yield differences were statically significant between control and conventional cabbages (25%) and broccolis (68%). The results indicate that there is on average an initial 25% yield difference between organic and conventional farming systems. Similar studies have shown that the yield gap can be reduced within three to four years. This study presents preliminary results of trials that are to continue for ten years, during which time the yield differences may vary.
- Full Text:
- Date Issued: 2016
Monitoring changes in vegetation distribution to ascertain the extent of degradation in the savannas of Nkonkobe Local Municipality, Eastern Cape, South Africa
- Authors: Masiza, Wonga
- Date: 2016
- Subjects: Savanna ecology -- South Africa -- Eastern Cape Land degradation -- South Africa -- Eastern Cape Vegetation management -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/2027 , vital:27598
- Description: Savanna degradation is an environmental problem occurring in most countries around the world and it poses threats to biodiversity conservation, the food industry, and other economic sectors. According to FAO, South Africa’s rangelands exhibit the highest rate of fragmentation in comparison to range ecosystems in neighbouring countries including Lesotho and Swaziland, and consensus among researchers is that communal rangelands are more degraded than commercial rangelands. Although researchers and communities have identified the occurrence of land degradation in communal savannas at a local scale, land degradation has been poorly estimated because little has been done to quantify the extent and dynamics of perceived and observed changes associated with land degradation. The main goal of this study is to provide empirical insights on the direction of changes in the communal savannas of Nkonkobe Local Municipality in order to inform policy formulation and implementation. Additional to the communal sites is a private farm included for comparative analysis of trends in communal and commercial savannas. Landsat imagery was used to map, assess, and quantify the extent of land degradation in Nkonkobe Local Municipality, over a period of 30 years between 1984 and 2014. Field investigations were undertaken in June 2015 to acquire reference data to guide supervised classification of Landsat images. Three algorithms (Mahalanobis-distance, Minimum-distance, and Maximum likelihood classification) were compared to identify a classifier that produced the best results. The maximum likelihood classifier produced the best results with classification accuracy levels of 95.24 percent, 89.66 percent, and 95.65 percent for Honeydale Farm, Thyume, and Sheshegu respectively. Regression analysis revealed that both communal and private lands have experienced statistically significant increases in bush encroachment and decreases in surface water. Communal savannas have been confronted more by expansion of built-up area, decrease in open grassland, abandonment of arable land, soil erosion, and a steady invasion by Acacia Karroo compared to the privately owned commercial farm. The land cover changes measured through this investigation suggest an environmental shift that threatens biodiversity and agricultural activity. The study provides empirically informed insights about the direction to which these savannas are changing with the hope that the findings will prompt formulation and implementation of effective policies.
- Full Text:
- Date Issued: 2016
- Authors: Masiza, Wonga
- Date: 2016
- Subjects: Savanna ecology -- South Africa -- Eastern Cape Land degradation -- South Africa -- Eastern Cape Vegetation management -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/2027 , vital:27598
- Description: Savanna degradation is an environmental problem occurring in most countries around the world and it poses threats to biodiversity conservation, the food industry, and other economic sectors. According to FAO, South Africa’s rangelands exhibit the highest rate of fragmentation in comparison to range ecosystems in neighbouring countries including Lesotho and Swaziland, and consensus among researchers is that communal rangelands are more degraded than commercial rangelands. Although researchers and communities have identified the occurrence of land degradation in communal savannas at a local scale, land degradation has been poorly estimated because little has been done to quantify the extent and dynamics of perceived and observed changes associated with land degradation. The main goal of this study is to provide empirical insights on the direction of changes in the communal savannas of Nkonkobe Local Municipality in order to inform policy formulation and implementation. Additional to the communal sites is a private farm included for comparative analysis of trends in communal and commercial savannas. Landsat imagery was used to map, assess, and quantify the extent of land degradation in Nkonkobe Local Municipality, over a period of 30 years between 1984 and 2014. Field investigations were undertaken in June 2015 to acquire reference data to guide supervised classification of Landsat images. Three algorithms (Mahalanobis-distance, Minimum-distance, and Maximum likelihood classification) were compared to identify a classifier that produced the best results. The maximum likelihood classifier produced the best results with classification accuracy levels of 95.24 percent, 89.66 percent, and 95.65 percent for Honeydale Farm, Thyume, and Sheshegu respectively. Regression analysis revealed that both communal and private lands have experienced statistically significant increases in bush encroachment and decreases in surface water. Communal savannas have been confronted more by expansion of built-up area, decrease in open grassland, abandonment of arable land, soil erosion, and a steady invasion by Acacia Karroo compared to the privately owned commercial farm. The land cover changes measured through this investigation suggest an environmental shift that threatens biodiversity and agricultural activity. The study provides empirically informed insights about the direction to which these savannas are changing with the hope that the findings will prompt formulation and implementation of effective policies.
- Full Text:
- Date Issued: 2016
The implications of the 2014 construction regulations for the Department of Public Works procurement system
- Authors: Matete, Kenevoe Rose
- Date: 2016
- Subjects: Construction industry -- Safety regulations -- South Africa Construction industry -- Standards -- South Africa Industrial procurement -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/10309 , vital:26651
- Description: The Organisation of Economic Co-operation and Development (OECD) notes that regulations seek to make improvements by changing individual or organisational behaviour in ways that generate positive impacts in terms of solving societal and economic problems. At its most basic level, regulations are designed to work according to implementation, leading to changes in behaviours that, in turn, lead to changes in outcomes. Such outcomes can be satisfaction in terms of an underlying problem or other (hopefully positive) changes in conditions in the world. Following this premise, this research project investigates the implications of the 2014 Construction Regulations for the Department of Public Works’ procurement system. The study also examines the contents of the construction Regulations; the impact of the Construction Regulations 2014 – permit-to-work; client / contractor procurement issues; the enforcement of compliance to permit-to-work requirements, and education and training demands in relation to health and safety (H&S) competency. The study shows that even though industry role players are relatively familiar with the Construction Regulations 2014, there is a common concern regarding competency (education and training) levels required for the implementation of the permit-to-work requirement of the regulations. The concerns focus on the ability of the Department of Labour (DoL) to process the permits. Based on the study’s findings, the research concludes that there would be cost implications for project actors when implementing the permit-to-work requirement and this cost factor could delay project initiation and planning, as well as service delivery.
- Full Text:
- Date Issued: 2016
- Authors: Matete, Kenevoe Rose
- Date: 2016
- Subjects: Construction industry -- Safety regulations -- South Africa Construction industry -- Standards -- South Africa Industrial procurement -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/10309 , vital:26651
- Description: The Organisation of Economic Co-operation and Development (OECD) notes that regulations seek to make improvements by changing individual or organisational behaviour in ways that generate positive impacts in terms of solving societal and economic problems. At its most basic level, regulations are designed to work according to implementation, leading to changes in behaviours that, in turn, lead to changes in outcomes. Such outcomes can be satisfaction in terms of an underlying problem or other (hopefully positive) changes in conditions in the world. Following this premise, this research project investigates the implications of the 2014 Construction Regulations for the Department of Public Works’ procurement system. The study also examines the contents of the construction Regulations; the impact of the Construction Regulations 2014 – permit-to-work; client / contractor procurement issues; the enforcement of compliance to permit-to-work requirements, and education and training demands in relation to health and safety (H&S) competency. The study shows that even though industry role players are relatively familiar with the Construction Regulations 2014, there is a common concern regarding competency (education and training) levels required for the implementation of the permit-to-work requirement of the regulations. The concerns focus on the ability of the Department of Labour (DoL) to process the permits. Based on the study’s findings, the research concludes that there would be cost implications for project actors when implementing the permit-to-work requirement and this cost factor could delay project initiation and planning, as well as service delivery.
- Full Text:
- Date Issued: 2016
The phytogeography of Southern Mistbelt Forests of the Eastern Cape, South Africa
- Authors: Matiwane, Aviwe
- Date: 2016
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/3224 , vital:20393
- Description: In the Eastern Cape, a moisture gradient (from west to east) exists along the Escarpment where patches of Southern Mistbelt Forests (SMF) occur. There is a notable profusion of plants in these forests, but the factors that drive plant species composition and abundance in these patches is poorly understood and such knowledge is critical if we are to address or mitigate the problems imposed by global change. Many of our ideas on plant community assembly are based on the premise that species differ in their environmental requirements for successful regeneration, especially when young. The aims of this study were to document the floristic diversity of poorly known patches of Southern Mistbelt Forests in the Eastern Cape and identify the environmental factors that influence plant community composition in these forest patches. Twenty six forest patches across the Eastern Cape were sampled. In each forest 400m2 circular plots were constructed. The diameter at breast height and stem counts for the tree species was taken and the % cover of the herbaceous species was recorded. General collections were also made to supplement the plot data in order to obtain a comprehensive flora for each forest patch. All sampling was done during the summer season of 2013 and 2014. Using plot data, Hierarchal Cluster Analysis and Multidimensional Scaling Analysis were done to compare similarities between patches. Plots from the same forest patch clustered which indicated that the species composition in each forest patch was unique. However, this pattern went down when only tree species were considered. Plant diversity also varied between patches; with those located in the east being generally more diverse than those in the west are. Clustering patterns in fragmented communities and differences in species diversity indicate evidence of species “nestedness”. Analysis of nestedness indicated that these forest patches were significantly nested. To identify which environmental variables might be correlated with both species diversity and nestedness, twelve environmental variables was selected for analysis using Canonical Correspondence Analysis and Principal Component Analysis. Results show that Mean Annual Precipitation, Mean Annual Potential Evapotranspiration, and percentage of Organic Matter of the soil were most strongly correlated with the patterns of diversity observed in these forest patches. Regression analysis indicated that Mean Annual Precipitation accounted for most of the variation in species diversity, especially for the herbaceous species. The herbaceous species thus show a greater sensitivity to “climate filtering” as a consequence of rainfall gradients. With the implementation of suitable monitoring programs, changes in abundance or even local extinction of these species can act as an early warning indicator of the possible long-term effects of climate change on forest communities.
- Full Text:
- Date Issued: 2016
- Authors: Matiwane, Aviwe
- Date: 2016
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/3224 , vital:20393
- Description: In the Eastern Cape, a moisture gradient (from west to east) exists along the Escarpment where patches of Southern Mistbelt Forests (SMF) occur. There is a notable profusion of plants in these forests, but the factors that drive plant species composition and abundance in these patches is poorly understood and such knowledge is critical if we are to address or mitigate the problems imposed by global change. Many of our ideas on plant community assembly are based on the premise that species differ in their environmental requirements for successful regeneration, especially when young. The aims of this study were to document the floristic diversity of poorly known patches of Southern Mistbelt Forests in the Eastern Cape and identify the environmental factors that influence plant community composition in these forest patches. Twenty six forest patches across the Eastern Cape were sampled. In each forest 400m2 circular plots were constructed. The diameter at breast height and stem counts for the tree species was taken and the % cover of the herbaceous species was recorded. General collections were also made to supplement the plot data in order to obtain a comprehensive flora for each forest patch. All sampling was done during the summer season of 2013 and 2014. Using plot data, Hierarchal Cluster Analysis and Multidimensional Scaling Analysis were done to compare similarities between patches. Plots from the same forest patch clustered which indicated that the species composition in each forest patch was unique. However, this pattern went down when only tree species were considered. Plant diversity also varied between patches; with those located in the east being generally more diverse than those in the west are. Clustering patterns in fragmented communities and differences in species diversity indicate evidence of species “nestedness”. Analysis of nestedness indicated that these forest patches were significantly nested. To identify which environmental variables might be correlated with both species diversity and nestedness, twelve environmental variables was selected for analysis using Canonical Correspondence Analysis and Principal Component Analysis. Results show that Mean Annual Precipitation, Mean Annual Potential Evapotranspiration, and percentage of Organic Matter of the soil were most strongly correlated with the patterns of diversity observed in these forest patches. Regression analysis indicated that Mean Annual Precipitation accounted for most of the variation in species diversity, especially for the herbaceous species. The herbaceous species thus show a greater sensitivity to “climate filtering” as a consequence of rainfall gradients. With the implementation of suitable monitoring programs, changes in abundance or even local extinction of these species can act as an early warning indicator of the possible long-term effects of climate change on forest communities.
- Full Text:
- Date Issued: 2016
The application of GIS and remote sensing to assess the effect of periodic flooding on communities along the Juskeiriver: A case study of Alexandria Township, Johannesburg, South Africa
- Authors: Mawasha, Tshepo Sylvester
- Date: 2016
- Subjects: Remote sensing Geographic information systems -- South Africa , Remote sensing
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/45613 , vital:38918
- Description: Floods are water induced disasters that led to temporary induction of dry and cause serious damages in the affected location such as loss of valuable assets, lives and destruction of infrastructure. Flooding had become common in Alexandra Township during rainfall season and the recorded impact of periodic flooding on communities is increasing at an alarming rate. This study seeks to identify populations vulnerable to flooding and to map-out areas at high risk of flood disasters, using GIS and RS as a tool. For GIS application different types of maps were produced, namely, flood vulnerability, hazards, risk and risk index map highlighting areas at risk of being affected by flooding. Flood risk index maps identify three categories of risk zones; low and high risk zone. The household units within each of the risk zones was calculated and the total was estimated to be 762 for low-risk and 32 486 for high risk zone. The SRTM Digital Elevation Model (DEM) and multi-temporal Satellite Probatoire d’Observation de la Terra (SPOT) satellite images for 1997, 2006 and 2013 of the area was used for land-use and land-cover (LULC) change analyses using maximum-likelihood post-classification comparison. Results reveal that tremendous urban development had taken place in the study area along the Jukskei River area for the past sixteen years. It was observed that there was a sharp decrease in vegetation from 237ha (1997) to 134ha (2006) to 68ha (2013). This may had a negative impact on the environment around this area by decreasing surface runoff. The trend however, shows that bare surface and vegetation land-cover class has no potential to recover. Questionnaires aimed at all the residents in the study area were used to assess the effect of periodic flooding on communities. Community leader and City of Johannesburg Disaster Management Unit (CoJDMU) interviews were also conducted to get more insight about floods management in the study area. Finally, strategies for alleviating flood risk in the study area were discussed and some recommendations were made to help the government and municipal authorities to improve and development sustainable flood mitigation measures.
- Full Text:
- Date Issued: 2016
- Authors: Mawasha, Tshepo Sylvester
- Date: 2016
- Subjects: Remote sensing Geographic information systems -- South Africa , Remote sensing
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/45613 , vital:38918
- Description: Floods are water induced disasters that led to temporary induction of dry and cause serious damages in the affected location such as loss of valuable assets, lives and destruction of infrastructure. Flooding had become common in Alexandra Township during rainfall season and the recorded impact of periodic flooding on communities is increasing at an alarming rate. This study seeks to identify populations vulnerable to flooding and to map-out areas at high risk of flood disasters, using GIS and RS as a tool. For GIS application different types of maps were produced, namely, flood vulnerability, hazards, risk and risk index map highlighting areas at risk of being affected by flooding. Flood risk index maps identify three categories of risk zones; low and high risk zone. The household units within each of the risk zones was calculated and the total was estimated to be 762 for low-risk and 32 486 for high risk zone. The SRTM Digital Elevation Model (DEM) and multi-temporal Satellite Probatoire d’Observation de la Terra (SPOT) satellite images for 1997, 2006 and 2013 of the area was used for land-use and land-cover (LULC) change analyses using maximum-likelihood post-classification comparison. Results reveal that tremendous urban development had taken place in the study area along the Jukskei River area for the past sixteen years. It was observed that there was a sharp decrease in vegetation from 237ha (1997) to 134ha (2006) to 68ha (2013). This may had a negative impact on the environment around this area by decreasing surface runoff. The trend however, shows that bare surface and vegetation land-cover class has no potential to recover. Questionnaires aimed at all the residents in the study area were used to assess the effect of periodic flooding on communities. Community leader and City of Johannesburg Disaster Management Unit (CoJDMU) interviews were also conducted to get more insight about floods management in the study area. Finally, strategies for alleviating flood risk in the study area were discussed and some recommendations were made to help the government and municipal authorities to improve and development sustainable flood mitigation measures.
- Full Text:
- Date Issued: 2016
Genetic structure and biogeography of three wrasse species (Labridae) within the Western Indian Ocean
- Authors: Mayekiso, Sisanda
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/1114 , vital:20021
- Description: The biogeography of wrasses within the Western Indian Ocean (WIO) is poorly understood, with regard to origins and genetic differentiation or connectivity among the regions of the WIO. This region is a good model for studying the influence of physical complexities and biogeographic breaks in shaping patterns of differentiation in wrasses. Three reef-associated fish species, Cheilio inermis, Thalassoma hebraicum and T. lunare, were selected to examine the factors that have influenced patterns of differentiation across the WIO. Each species was sampled from various localities of the WIO, the Red Sea and Indo-West Pacific Islands. Sequence data were generated from two mitochondrial gene fragments (cytochrome b and ATPase 6) and one nuclear locus (the first intron of the ribosomal protein S7 gene). Genetic analyses were used to calculate genetic diversity indices within species, which were then compared among species. The relationships among haplotypes and alleles were constructed using median-joining networks. Where necessary, neighbour-joining trees (NJ) were constructed to examine relationships among haplotypes and alleles for the Thalassoma species. Population structure was analysed using AMOVA and pairwise ФST to compare and calculate differentiation between the WIO localities. Mismatch distributions were used to examine population growth and decline or stability, and demographic parameters were used to calculate time of population expansion. There was high haplotype (h = 0.88 to 0.98) and low nucleotide diversities (π = 0.003 to 0.008) among all species for mitochondrial markers. For S7 intron I, high allelic (A = 0.95 to 0.98) and low nucleotide diversities (π = 0.002 to 0.014) were observed for all species. The pairwise ФST values revealed little to great (ФST = -0.02 to 0.67) genetic differentiation between localities, across all species for the three gene regions. The pairwise comparisons indicated the differentiation in C. inermis of Tanzania and Kenya from Mozambique and Nosy Be (Madagascar). The widespread C. inermis also revealed the differentiation of Kenya and Tanzania. For C. inermis, the AMOVAs of ATPase 6 and cytochrome b data indicated high differentiation among defined locality groups. The groups were defined according to geographic proximity. However, the AMOVA of the nuclear gene (S7 intron I) did not find variation among defined locality groups. Cheilio inermis revealed a sequence divergence of 0.4%. The divergence that was found in C. inermis was not enough to suggest a cryptic species within the WIO. Overall, the widespread and monotypic C. inermis revealed genetic differentiation within the WIO. Thalassoma hebraicum generally revealed little genetic differentiation across the WIO. The AMOVAs of the three gene regions showed no variation among specimens of the defined locality groups. However, some differentiation was found between localities. The pairwise comparisons of T. hebraicum revealed the differentiation of Seychelles from the African mainland and Madagascar. Southern Africa was observed to be differentiated from Nosy Be and Zanzibar. The observed differentiation could be caused by oceanic barriers such as the South Equatorial Current (SEQC), East African Coastal Current (EACC), and the Comoros Gyres and eddies in the Mozambique Channel, and Agulhas Current. Thalassoma lunare revealed genetic isolation between the WIO and the Red Sea as well as within the WIO. The genetic isolation between the WIO and the Red Sea is probably due to the historical isolation by the Bab al Mandab and contemporary barriers such as the cold upwelling cells in Somalia. The differentiation of Maldives from the African mainland and Seychelles could be due to distance and the upwelling cells created by monsoon winds. Mismatch distributions suggested that C. inermis and T. hebraicum had undergone demographic expansion during the Pleistocene (92 678 to 40 219 years ago). The results of the current study are similar to those from previous studies of WIO reef fish species, and the results of the present study could have potential implications for conservation and fisheries management. Single genetic markers and single species studies do not detect all barriers to dispersal in the WIO, thus they are insufficient to inform conservation management. Thus, the use of multispecies and genetic markers in the current study can be adopted by other studies of the marine taxa of the WIO.
- Full Text:
- Date Issued: 2016
- Authors: Mayekiso, Sisanda
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/1114 , vital:20021
- Description: The biogeography of wrasses within the Western Indian Ocean (WIO) is poorly understood, with regard to origins and genetic differentiation or connectivity among the regions of the WIO. This region is a good model for studying the influence of physical complexities and biogeographic breaks in shaping patterns of differentiation in wrasses. Three reef-associated fish species, Cheilio inermis, Thalassoma hebraicum and T. lunare, were selected to examine the factors that have influenced patterns of differentiation across the WIO. Each species was sampled from various localities of the WIO, the Red Sea and Indo-West Pacific Islands. Sequence data were generated from two mitochondrial gene fragments (cytochrome b and ATPase 6) and one nuclear locus (the first intron of the ribosomal protein S7 gene). Genetic analyses were used to calculate genetic diversity indices within species, which were then compared among species. The relationships among haplotypes and alleles were constructed using median-joining networks. Where necessary, neighbour-joining trees (NJ) were constructed to examine relationships among haplotypes and alleles for the Thalassoma species. Population structure was analysed using AMOVA and pairwise ФST to compare and calculate differentiation between the WIO localities. Mismatch distributions were used to examine population growth and decline or stability, and demographic parameters were used to calculate time of population expansion. There was high haplotype (h = 0.88 to 0.98) and low nucleotide diversities (π = 0.003 to 0.008) among all species for mitochondrial markers. For S7 intron I, high allelic (A = 0.95 to 0.98) and low nucleotide diversities (π = 0.002 to 0.014) were observed for all species. The pairwise ФST values revealed little to great (ФST = -0.02 to 0.67) genetic differentiation between localities, across all species for the three gene regions. The pairwise comparisons indicated the differentiation in C. inermis of Tanzania and Kenya from Mozambique and Nosy Be (Madagascar). The widespread C. inermis also revealed the differentiation of Kenya and Tanzania. For C. inermis, the AMOVAs of ATPase 6 and cytochrome b data indicated high differentiation among defined locality groups. The groups were defined according to geographic proximity. However, the AMOVA of the nuclear gene (S7 intron I) did not find variation among defined locality groups. Cheilio inermis revealed a sequence divergence of 0.4%. The divergence that was found in C. inermis was not enough to suggest a cryptic species within the WIO. Overall, the widespread and monotypic C. inermis revealed genetic differentiation within the WIO. Thalassoma hebraicum generally revealed little genetic differentiation across the WIO. The AMOVAs of the three gene regions showed no variation among specimens of the defined locality groups. However, some differentiation was found between localities. The pairwise comparisons of T. hebraicum revealed the differentiation of Seychelles from the African mainland and Madagascar. Southern Africa was observed to be differentiated from Nosy Be and Zanzibar. The observed differentiation could be caused by oceanic barriers such as the South Equatorial Current (SEQC), East African Coastal Current (EACC), and the Comoros Gyres and eddies in the Mozambique Channel, and Agulhas Current. Thalassoma lunare revealed genetic isolation between the WIO and the Red Sea as well as within the WIO. The genetic isolation between the WIO and the Red Sea is probably due to the historical isolation by the Bab al Mandab and contemporary barriers such as the cold upwelling cells in Somalia. The differentiation of Maldives from the African mainland and Seychelles could be due to distance and the upwelling cells created by monsoon winds. Mismatch distributions suggested that C. inermis and T. hebraicum had undergone demographic expansion during the Pleistocene (92 678 to 40 219 years ago). The results of the current study are similar to those from previous studies of WIO reef fish species, and the results of the present study could have potential implications for conservation and fisheries management. Single genetic markers and single species studies do not detect all barriers to dispersal in the WIO, thus they are insufficient to inform conservation management. Thus, the use of multispecies and genetic markers in the current study can be adopted by other studies of the marine taxa of the WIO.
- Full Text:
- Date Issued: 2016
Consumer perceptions and microbial quality of meat sold in the informal markets of Nkonkobe and Buffalo City municipalities in the Eastern province, South Africa
- Authors: Mazizi, Bulelani Elvis
- Date: 2016
- Subjects: Meat -- Quality -- South Africa --Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/15365 , vital:40401
- Description: The main objective of the study was to determine consumer perceptions and microbial quality of meat sold in the informal markets found in Nkonkobe and Buffalo City Municipalities in the Eastern Cape Province, South Africa. To determine consumer perceptions of the quality of the meat and meat products sold in the informal markets in Nkonkobe and Buffalo City Municipalities, a survey was conducted. A total of 160 consumers from two municipalities in the Eastern Cape (EC) Province of South Africa was randomly sampled and interviewed. A questionnaire was used to gather information about consumer perceptions of meat and meat products sold in the informal markets regarding their knowledge about safety, food-borne diseases, hygiene, and the quality of the meat among others. The study showed that Alice Town has a larger (66.25percent) proportion of consumers with knowledge about foodborne diseases while King Williams’s Town had a larger proportion (48.75percent) of respondents who had no knowledge about Food-borne diseases. However, a large proportion of consumers in King Williams’s Town considered vendor (82.5percent) and environmental hygiene (93.75percent) than in Alice Town. Consumers (83.75percent) in King Williams’s Town viewed the meat from street vendors to be of low quality while a small proportion (18.75percent) of consumers in Alice Town viewed it as the meat of good quality. Alice had a large proportion (61.25percent) of consumers, which had knowledge of the meat safety law than King Williams’s Town. More consumers from King Williams’s Town (31.25percent) agreed that government plays a role while Alice had a small proportion (26.25percent) which disagreed. The results also showed that consumer perceptions about the safety of meat and meat products are focused more on hygiene, neglecting other important aspects such as vending infrastructure. However, most consumers do not have enough knowledge concerning meat safety. The second study determined the microbial quality of meat sold by street vendors based in Alice and Kind Williams Town in the Eastern Cape Province South Africa. A total of 48 fresh and uncooked meat samples (beef, pork, and mutton), 48 surface contact plates and 40 water samples was collected from 4 street vendors from each town for microbial analysis (n=48). After collection, all samples were subjected to Aerobic plate count (APC), Salmonella spp, Staphylococcus aureus (Staph) and Escherichia coli (E. coli). The results revealed that Salmonella spp tested negative across all the meat samples used in the study. However, no significant differences were found in the microbial quality of meat sold by street vendors in Alice and King Williams town. Furthermore, there were no significant differences (P>0.05) between the APC of raw beef (4.8 Log CFU/g), mutton (3.7 Log CFU/g) and pork (2.8 Log CFU/g) and also the cooked beef (1.5 Log CFU/g), mutton (1.3 Log CFU/g) and pork (1.9 Log CFU/g) samples. A similar trend was observed in the values of Staphylococcus aureus (Staph) and Escherichia coli (E. coli) counts in raw and cooked meat samples. However, a positive correlation between Aerobic plate counts (APC) and Staphylococcus aureus (Staph) (P<0.001) and Escherichia coli (E. coli) (P<0.01) was found in the study. It can, therefore, be concluded that there were no differences in the microbial counts of raw and cooked meat sold in the informal markets of Nkonkobe and Buffalo City Municipalities in the Eastern Cape Province, South Africa.
- Full Text:
- Date Issued: 2016
- Authors: Mazizi, Bulelani Elvis
- Date: 2016
- Subjects: Meat -- Quality -- South Africa --Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/15365 , vital:40401
- Description: The main objective of the study was to determine consumer perceptions and microbial quality of meat sold in the informal markets found in Nkonkobe and Buffalo City Municipalities in the Eastern Cape Province, South Africa. To determine consumer perceptions of the quality of the meat and meat products sold in the informal markets in Nkonkobe and Buffalo City Municipalities, a survey was conducted. A total of 160 consumers from two municipalities in the Eastern Cape (EC) Province of South Africa was randomly sampled and interviewed. A questionnaire was used to gather information about consumer perceptions of meat and meat products sold in the informal markets regarding their knowledge about safety, food-borne diseases, hygiene, and the quality of the meat among others. The study showed that Alice Town has a larger (66.25percent) proportion of consumers with knowledge about foodborne diseases while King Williams’s Town had a larger proportion (48.75percent) of respondents who had no knowledge about Food-borne diseases. However, a large proportion of consumers in King Williams’s Town considered vendor (82.5percent) and environmental hygiene (93.75percent) than in Alice Town. Consumers (83.75percent) in King Williams’s Town viewed the meat from street vendors to be of low quality while a small proportion (18.75percent) of consumers in Alice Town viewed it as the meat of good quality. Alice had a large proportion (61.25percent) of consumers, which had knowledge of the meat safety law than King Williams’s Town. More consumers from King Williams’s Town (31.25percent) agreed that government plays a role while Alice had a small proportion (26.25percent) which disagreed. The results also showed that consumer perceptions about the safety of meat and meat products are focused more on hygiene, neglecting other important aspects such as vending infrastructure. However, most consumers do not have enough knowledge concerning meat safety. The second study determined the microbial quality of meat sold by street vendors based in Alice and Kind Williams Town in the Eastern Cape Province South Africa. A total of 48 fresh and uncooked meat samples (beef, pork, and mutton), 48 surface contact plates and 40 water samples was collected from 4 street vendors from each town for microbial analysis (n=48). After collection, all samples were subjected to Aerobic plate count (APC), Salmonella spp, Staphylococcus aureus (Staph) and Escherichia coli (E. coli). The results revealed that Salmonella spp tested negative across all the meat samples used in the study. However, no significant differences were found in the microbial quality of meat sold by street vendors in Alice and King Williams town. Furthermore, there were no significant differences (P>0.05) between the APC of raw beef (4.8 Log CFU/g), mutton (3.7 Log CFU/g) and pork (2.8 Log CFU/g) and also the cooked beef (1.5 Log CFU/g), mutton (1.3 Log CFU/g) and pork (1.9 Log CFU/g) samples. A similar trend was observed in the values of Staphylococcus aureus (Staph) and Escherichia coli (E. coli) counts in raw and cooked meat samples. However, a positive correlation between Aerobic plate counts (APC) and Staphylococcus aureus (Staph) (P<0.001) and Escherichia coli (E. coli) (P<0.01) was found in the study. It can, therefore, be concluded that there were no differences in the microbial counts of raw and cooked meat sold in the informal markets of Nkonkobe and Buffalo City Municipalities in the Eastern Cape Province, South Africa.
- Full Text:
- Date Issued: 2016
Construction small and medium enterprise development
- Authors: Mbambe, Putumani
- Date: 2016
- Subjects: Construction industry -- Management Small business -- South Africa -- Port Elizabeth Building -- Development
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/11681 , vital:26950
- Description: The objective of this treatise study was to determine the leading causes which limit the development of SMME contractors, to ascertain the accessibility of SMME incubators available to support SMME development and to identify the cause of poor management performance by SMME contractors based in the Nelson Mandela Bay Metropolitan Municipality. A qualitative method was adopted for this study. The primary data was collected using a structured interview guide which incorporated the sub problems and the research questions. The salient findings of this study are: SMME contractors are unaware of the available business information and government support programmes designed to assist them; SMME contractors do not receive capital from banks when they don‟t have collateral; Desperation to secure projects among SMME contractors is the leading cause for under-pricing; SMME contractors are still paid later than the 30 day period for completed work; SMME owners who had started their construction companies lacked training and do not have the relevant experience and knowledge required to manage a construction company. In summary the study concluded that SMME who have access to capital have high growth prospects than those that have not. Accessibility to information and awareness of available opportunities remains significant for the growth of SMMEs. Construction related knowledge and training for SMME owners contributes vastly to the success of SMME companies. The study recommended that; Government needs to promote the accessibility of SMME incubators and ensure institutions designed to assist SMMEs with finance are accessible; The effectiveness of current development programs for small enterprises and skills development programs should be reviewed; MMBM should setup a mentoring program to help train SMME contractors theoretically and practically; NMBM local government should promote women to own SMMEs in order to close the gap of inequality in the built environment; Banks must work with government institutions to ensure that they are able to fund SMMEs.
- Full Text:
- Date Issued: 2016
- Authors: Mbambe, Putumani
- Date: 2016
- Subjects: Construction industry -- Management Small business -- South Africa -- Port Elizabeth Building -- Development
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/11681 , vital:26950
- Description: The objective of this treatise study was to determine the leading causes which limit the development of SMME contractors, to ascertain the accessibility of SMME incubators available to support SMME development and to identify the cause of poor management performance by SMME contractors based in the Nelson Mandela Bay Metropolitan Municipality. A qualitative method was adopted for this study. The primary data was collected using a structured interview guide which incorporated the sub problems and the research questions. The salient findings of this study are: SMME contractors are unaware of the available business information and government support programmes designed to assist them; SMME contractors do not receive capital from banks when they don‟t have collateral; Desperation to secure projects among SMME contractors is the leading cause for under-pricing; SMME contractors are still paid later than the 30 day period for completed work; SMME owners who had started their construction companies lacked training and do not have the relevant experience and knowledge required to manage a construction company. In summary the study concluded that SMME who have access to capital have high growth prospects than those that have not. Accessibility to information and awareness of available opportunities remains significant for the growth of SMMEs. Construction related knowledge and training for SMME owners contributes vastly to the success of SMME companies. The study recommended that; Government needs to promote the accessibility of SMME incubators and ensure institutions designed to assist SMMEs with finance are accessible; The effectiveness of current development programs for small enterprises and skills development programs should be reviewed; MMBM should setup a mentoring program to help train SMME contractors theoretically and practically; NMBM local government should promote women to own SMMEs in order to close the gap of inequality in the built environment; Banks must work with government institutions to ensure that they are able to fund SMMEs.
- Full Text:
- Date Issued: 2016
The impact of three different footwear conditions on individual biomechanical, physiological and perceptual responses during running.
- Authors: McDougall, Justin John
- Date: 2016
- Subjects: Running -- Physiological aspects , Running shoes -- Physiological aspects , Running -- Health aspects
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5177 , http://hdl.handle.net/10962/d1019988
- Description: Background: Despite the introduction of running footwear in the 1970’s, running injury rates continue to be unacceptably high. The subsequent revival of barefoot running and the introduction of minimalist footwear occurred, in an attempt to reduce injury rates and increase performance. There is much contention in the literature around the effectiveness of these footwear conditions. Furthermore individual responses have recently been proposed to provide more accurate and reflective conclusions than the use of mean data. Objectives: Twofold: a) to compare the biomechanical, physiological and perceptual responses between the shod, minimalist and barefoot footwear conditions and b) to assess and compare individual responses under these footwear conditions. Methods: 26 well-trained, male, habitually shod endurance runners, aged between 18 - 30 years completed three experimental sessions on an indoor runway and motorized treadmill. Each session was completed in either the shod, minimalist or barefoot condition, running at 15km.h-1. Variables assessed included stride rate, stride length, impact peak, vertical impact and average loading rate and strike time (biomechanical); heart rate, oxygen consumption and electromyography (physiological); and rating of perceived exertion and body discomfort (perceptual). Results: Biomechanics – Stride rate and stride length showed a significant (p<0.001) increase and decrease respectively when running in the minimalist or barefoot conditions versus shod. Running barefoot versus the minimalist and shod conditions resulted in a significantly (p<0.001) greater vertical impact loading rate. Strike time was significantly (p=0.008) reduced running in the minimalist and barefoot conditions versus shod. Physiology – Running barefoot versus shod resulted in a significantly (p=0.02) reduced heart rate and Tibialis Anterior activity (p=0.005). There was a large variability in individual responses for many variables, with responders and non-responders seen. Conclusion: The study suggests that there are significant differences between all three forms of running for some variables. It was further noted that there is support for the proposal that individual responses are highly variable and should be analysed accordingly
- Full Text:
- Date Issued: 2016
- Authors: McDougall, Justin John
- Date: 2016
- Subjects: Running -- Physiological aspects , Running shoes -- Physiological aspects , Running -- Health aspects
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5177 , http://hdl.handle.net/10962/d1019988
- Description: Background: Despite the introduction of running footwear in the 1970’s, running injury rates continue to be unacceptably high. The subsequent revival of barefoot running and the introduction of minimalist footwear occurred, in an attempt to reduce injury rates and increase performance. There is much contention in the literature around the effectiveness of these footwear conditions. Furthermore individual responses have recently been proposed to provide more accurate and reflective conclusions than the use of mean data. Objectives: Twofold: a) to compare the biomechanical, physiological and perceptual responses between the shod, minimalist and barefoot footwear conditions and b) to assess and compare individual responses under these footwear conditions. Methods: 26 well-trained, male, habitually shod endurance runners, aged between 18 - 30 years completed three experimental sessions on an indoor runway and motorized treadmill. Each session was completed in either the shod, minimalist or barefoot condition, running at 15km.h-1. Variables assessed included stride rate, stride length, impact peak, vertical impact and average loading rate and strike time (biomechanical); heart rate, oxygen consumption and electromyography (physiological); and rating of perceived exertion and body discomfort (perceptual). Results: Biomechanics – Stride rate and stride length showed a significant (p<0.001) increase and decrease respectively when running in the minimalist or barefoot conditions versus shod. Running barefoot versus the minimalist and shod conditions resulted in a significantly (p<0.001) greater vertical impact loading rate. Strike time was significantly (p=0.008) reduced running in the minimalist and barefoot conditions versus shod. Physiology – Running barefoot versus shod resulted in a significantly (p=0.02) reduced heart rate and Tibialis Anterior activity (p=0.005). There was a large variability in individual responses for many variables, with responders and non-responders seen. Conclusion: The study suggests that there are significant differences between all three forms of running for some variables. It was further noted that there is support for the proposal that individual responses are highly variable and should be analysed accordingly
- Full Text:
- Date Issued: 2016
The GARCH-EVT-Copula model and simulation in scenario-based asset allocation
- McEwan, Peter Gareth Fredric
- Authors: McEwan, Peter Gareth Fredric
- Date: 2016
- Subjects: Extreme value theory GARCH model
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/11732 , vital:26961
- Description: Financial market integration, in particular, portfolio allocations from advanced economies to South African markets, continues to strengthen volatility linkages and quicken volatility transmissions between participating markets. Largely as a result, South African portfolios are net recipients of returns and volatility shocks emanating from major world markets. In light of these, and other, sources of risk, this dissertation proposes a methodology to improve risk management systems in funds by building a contemporary asset allocation framework that offers practitioners an opportunity to explicitly model combinations of hypothesised global risks and the effects on their investments. The framework models portfolio return variables and their key risk driver variables separately and then joins them to model their combined dependence structure. The separate modelling of univariate and multivariate (MV) components admits the benefit of capturing the data generating processes with improved accuracy. Univariate variables were modelled using ARMA-GARCH-family structures paired with a variety of skewed and leptokurtic conditional distributions. Model residuals were fit using the Peaks-over-Threshold method from Extreme Value Theory for the tails and a non-parametric, kernel density for the interior, forming a completed semi-parametric distribution (SPD) for each variable. Asset and risk factor returns were then combined and their dependence structure jointly modelled with a MV Student t copula. Finally, the SPD margins and Student t copula were used to construct a MV meta t distribution. Monte Carlo simulations were generated from the fitted MV meta t distribution on which an out-of-sample test was conducted. The 2014-to-2015 horizon served to proxy as an out-of-sample, forward-looking scenario for a set of key risk factors against which a hypothetical, diversified portfolio was optimised. Traditional mean-variance and contemporary mean-CVaR optimisation techniques were used and their results compared. As an addendum, performance over the in-sample 2008 financial crisis was reported. The final Objective (7) addressed management and conservation strategies for the NMBM. The NMBM wetland database that was produced during this research is currently being used by the Municipality and will be added to the latest National Wetland Map. From the database, and tools developed in this research, approximately 90 wetlands have been identified as being highly vulnerable due to anthropogenic and environmental factors (Chapter 6) and should be earmarked as key conservation priority areas. Based on field experience and data collected, this study has also made conservation and rehabilitation recommendations for eight locations. Recommendations are also provided for six more wetland systems (or regions) that should be prioritised for further research, as these systems lack fundamental information on where the threat of anthropogenic activities affecting them is greatest. This study has made a significant contribution to understanding the underlying geomorphological processes in depressions, seeps and wetland flats. The desktop mapping component of this study illustrated the dominance of wetlands in the wetter parts of the Municipality. Perched wetland systems were identified in the field, on shallow bedrock, calcrete or clay. The prevalence of these perches in depressions, seeps and wetland flats also highlighted the importance of rainfall in driving wetland formation, by allowing water to pool on these perches, in the NMBM. These perches are likely to be a key factor in the high number of small, ephemeral wetlands that were observed in the study area, compared to other semi-arid regions. Therefore, this research highlights the value of multi-faceted and multi-scalar wetland research and how similar approaches should be used in future research methods has been highlighted. The approach used, along with the tools/methods developed in this study have facilitated the establishment of priority areas for conservation and management within the NMBM. Furthermore, the research approach has revealed emergent wetland properties that are only apparent when looking at different spatial scales. This research has highlighted the complex biological and geomorphological interactions between wetlands that operate over various spatial and temporal scales. As such, wetland management should occur across a wetland complex, rather than individual sites, to account for these multi-scalar influences.
- Full Text:
- Date Issued: 2016
- Authors: McEwan, Peter Gareth Fredric
- Date: 2016
- Subjects: Extreme value theory GARCH model
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/11732 , vital:26961
- Description: Financial market integration, in particular, portfolio allocations from advanced economies to South African markets, continues to strengthen volatility linkages and quicken volatility transmissions between participating markets. Largely as a result, South African portfolios are net recipients of returns and volatility shocks emanating from major world markets. In light of these, and other, sources of risk, this dissertation proposes a methodology to improve risk management systems in funds by building a contemporary asset allocation framework that offers practitioners an opportunity to explicitly model combinations of hypothesised global risks and the effects on their investments. The framework models portfolio return variables and their key risk driver variables separately and then joins them to model their combined dependence structure. The separate modelling of univariate and multivariate (MV) components admits the benefit of capturing the data generating processes with improved accuracy. Univariate variables were modelled using ARMA-GARCH-family structures paired with a variety of skewed and leptokurtic conditional distributions. Model residuals were fit using the Peaks-over-Threshold method from Extreme Value Theory for the tails and a non-parametric, kernel density for the interior, forming a completed semi-parametric distribution (SPD) for each variable. Asset and risk factor returns were then combined and their dependence structure jointly modelled with a MV Student t copula. Finally, the SPD margins and Student t copula were used to construct a MV meta t distribution. Monte Carlo simulations were generated from the fitted MV meta t distribution on which an out-of-sample test was conducted. The 2014-to-2015 horizon served to proxy as an out-of-sample, forward-looking scenario for a set of key risk factors against which a hypothetical, diversified portfolio was optimised. Traditional mean-variance and contemporary mean-CVaR optimisation techniques were used and their results compared. As an addendum, performance over the in-sample 2008 financial crisis was reported. The final Objective (7) addressed management and conservation strategies for the NMBM. The NMBM wetland database that was produced during this research is currently being used by the Municipality and will be added to the latest National Wetland Map. From the database, and tools developed in this research, approximately 90 wetlands have been identified as being highly vulnerable due to anthropogenic and environmental factors (Chapter 6) and should be earmarked as key conservation priority areas. Based on field experience and data collected, this study has also made conservation and rehabilitation recommendations for eight locations. Recommendations are also provided for six more wetland systems (or regions) that should be prioritised for further research, as these systems lack fundamental information on where the threat of anthropogenic activities affecting them is greatest. This study has made a significant contribution to understanding the underlying geomorphological processes in depressions, seeps and wetland flats. The desktop mapping component of this study illustrated the dominance of wetlands in the wetter parts of the Municipality. Perched wetland systems were identified in the field, on shallow bedrock, calcrete or clay. The prevalence of these perches in depressions, seeps and wetland flats also highlighted the importance of rainfall in driving wetland formation, by allowing water to pool on these perches, in the NMBM. These perches are likely to be a key factor in the high number of small, ephemeral wetlands that were observed in the study area, compared to other semi-arid regions. Therefore, this research highlights the value of multi-faceted and multi-scalar wetland research and how similar approaches should be used in future research methods has been highlighted. The approach used, along with the tools/methods developed in this study have facilitated the establishment of priority areas for conservation and management within the NMBM. Furthermore, the research approach has revealed emergent wetland properties that are only apparent when looking at different spatial scales. This research has highlighted the complex biological and geomorphological interactions between wetlands that operate over various spatial and temporal scales. As such, wetland management should occur across a wetland complex, rather than individual sites, to account for these multi-scalar influences.
- Full Text:
- Date Issued: 2016
Relevance of the family assessment for least developed countries (FALDC) assessment tool rendering child protection services in the Eastern Cape, South Africa
- Authors: Mgidi, Siphelele
- Date: 2016
- Subjects: Child abuse -- South Africa -- Prevention Family social work -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/6335 , vital:29578
- Description: Assessment tools have been used for various purposes, including for protecting children from maltreatment. The main aim of this study was to to evaluate and determine the relevance of the Family Assessment for Leased Developed Countries (FALDC) assessment tool for child protection services in the Eastern Cape Province. The research was conducted using the social developmental welfare approach (Patel, 2005) and ecological systems theory (Healy, 2005). The study made use of the qualitative research method; in doing so the study made use of the case study design. In using the qualitative research method, focus group discussions were conducted with 29 social workers involved in child protection services. The findings of the study indicated that the FALDC assessment tool provides information useful for child protection services even though it contains sections that are regarded as less relevant to child protection. The study also founded that the FALDC assessment tool is relevant to child protection in the South African context, yet it needs to be aligned so that it provides much of the information desired by those involved in child protection. A conclusion drawn from this study is that the FALDC assessment tool appears to be relevant for child protection services. The FALDC assessment tool needs to be adjusted taking into consideration other aspects important to child protection in the South African child protection context.
- Full Text:
- Date Issued: 2016
- Authors: Mgidi, Siphelele
- Date: 2016
- Subjects: Child abuse -- South Africa -- Prevention Family social work -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/6335 , vital:29578
- Description: Assessment tools have been used for various purposes, including for protecting children from maltreatment. The main aim of this study was to to evaluate and determine the relevance of the Family Assessment for Leased Developed Countries (FALDC) assessment tool for child protection services in the Eastern Cape Province. The research was conducted using the social developmental welfare approach (Patel, 2005) and ecological systems theory (Healy, 2005). The study made use of the qualitative research method; in doing so the study made use of the case study design. In using the qualitative research method, focus group discussions were conducted with 29 social workers involved in child protection services. The findings of the study indicated that the FALDC assessment tool provides information useful for child protection services even though it contains sections that are regarded as less relevant to child protection. The study also founded that the FALDC assessment tool is relevant to child protection in the South African context, yet it needs to be aligned so that it provides much of the information desired by those involved in child protection. A conclusion drawn from this study is that the FALDC assessment tool appears to be relevant for child protection services. The FALDC assessment tool needs to be adjusted taking into consideration other aspects important to child protection in the South African child protection context.
- Full Text:
- Date Issued: 2016
Mesoscale mechanisms of larval transport and settlement in relation to physical factors off the south coast of South Africa: a topographic approach
- Authors: Mian, Shana Iva
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5947 , http://hdl.handle.net/10962/d1020844
- Description: The majority of benthic marine invertebrate life cycles include a meroplanktonic phase. Most marine biologists recognise that this stage could play an important role in dispersal, especially for sedentary or sessile organisms. Recent studies on larval dispersal have found that dispersal does not occur to the extent that was previously believed. Some larvae instead remain close to their natal populations through larval nearshore retention mechanisms, both active and passive. This study attempted to a) describe nearshore distribution patterns of several intertidal larvae in relation to nearshore hydrodynamics, b) infer whether larvae are active or passive in the water column and whether this differs among taxa and c) compare pelagic mussel larval abundance with settlement rates, at 2 bay and 2 open coast sites on the south coast of South Africa to note any topographical effects. At each of the four sites, pelagic samples were collected along 2 transects. Larvae and current speed data were collected at various depths (surface, mid-depth and bottom) at distances of 200, 400, 900 and 2400m offshore of the coast. Settlement samples were collected at sites that were onshore of the pelagic transects using plastic souring pads following previous studies. Pelagic larval distribution showed no effect of topography. Instead larval abundance was highly variable among sample periods and among different taxa. Slow swimming D-stage mussel larvae were found to be positively correlated with both upwelling and turbulence indices suggesting that they behave as passive particles in the water column. The abundances of larval taxa with faster swimming speeds than the D-larvae were negatively correlated with upwelling and did not correlate with turbulence. This suggests that these larvae are more active within the water column than the D-larvae which would theoretically allow them to maintain their position in the water column. Further analysis revealed that mean larval depth correlated with mean depth of shoreward moving water masses regardless of the state of upwelling. These results suggest that larvae were actively selecting the depth at which they were found presumably in order to associate themselves with shoreward moving currents. This interpretation was supported by ontogenetic patterns in the behaviour of barnacle larvae, the nauplii of which were found further offshore as they aged, and closer onshore again once they reach the faster swimming cyprid stage. Although there was no detectable effect of topography on the abundances of planktonic larvae, the settlement section of this study revealed an effect of topography, with higher settlement and recruitment rates at bay sites than at the open coast sites. Settlement rates were seen to be negatively correlated with turbulence at bay sites but not open coast sites. Recruitment rates for each sample event were positively correlated with upwelling at each site. This study found pelagic larvae to be generally active within the water column which allowed them to remain close to the shore regardless of topography and upwelling/turbulence regimes. Although meaningful correlation analyses between pelagic larval supply and settlement rates could not be conducted due to loss of settlement collectors, settlement rates were affected by local topography with higher settlement and recruitment in bay sites.
- Full Text:
- Date Issued: 2016
- Authors: Mian, Shana Iva
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5947 , http://hdl.handle.net/10962/d1020844
- Description: The majority of benthic marine invertebrate life cycles include a meroplanktonic phase. Most marine biologists recognise that this stage could play an important role in dispersal, especially for sedentary or sessile organisms. Recent studies on larval dispersal have found that dispersal does not occur to the extent that was previously believed. Some larvae instead remain close to their natal populations through larval nearshore retention mechanisms, both active and passive. This study attempted to a) describe nearshore distribution patterns of several intertidal larvae in relation to nearshore hydrodynamics, b) infer whether larvae are active or passive in the water column and whether this differs among taxa and c) compare pelagic mussel larval abundance with settlement rates, at 2 bay and 2 open coast sites on the south coast of South Africa to note any topographical effects. At each of the four sites, pelagic samples were collected along 2 transects. Larvae and current speed data were collected at various depths (surface, mid-depth and bottom) at distances of 200, 400, 900 and 2400m offshore of the coast. Settlement samples were collected at sites that were onshore of the pelagic transects using plastic souring pads following previous studies. Pelagic larval distribution showed no effect of topography. Instead larval abundance was highly variable among sample periods and among different taxa. Slow swimming D-stage mussel larvae were found to be positively correlated with both upwelling and turbulence indices suggesting that they behave as passive particles in the water column. The abundances of larval taxa with faster swimming speeds than the D-larvae were negatively correlated with upwelling and did not correlate with turbulence. This suggests that these larvae are more active within the water column than the D-larvae which would theoretically allow them to maintain their position in the water column. Further analysis revealed that mean larval depth correlated with mean depth of shoreward moving water masses regardless of the state of upwelling. These results suggest that larvae were actively selecting the depth at which they were found presumably in order to associate themselves with shoreward moving currents. This interpretation was supported by ontogenetic patterns in the behaviour of barnacle larvae, the nauplii of which were found further offshore as they aged, and closer onshore again once they reach the faster swimming cyprid stage. Although there was no detectable effect of topography on the abundances of planktonic larvae, the settlement section of this study revealed an effect of topography, with higher settlement and recruitment rates at bay sites than at the open coast sites. Settlement rates were seen to be negatively correlated with turbulence at bay sites but not open coast sites. Recruitment rates for each sample event were positively correlated with upwelling at each site. This study found pelagic larvae to be generally active within the water column which allowed them to remain close to the shore regardless of topography and upwelling/turbulence regimes. Although meaningful correlation analyses between pelagic larval supply and settlement rates could not be conducted due to loss of settlement collectors, settlement rates were affected by local topography with higher settlement and recruitment in bay sites.
- Full Text:
- Date Issued: 2016
Characterization of various garden grass species for energy conversion in a down draft biomass gasifier
- Authors: Mkosi, Lungisa
- Date: 2016
- Subjects: Biomass energy Greenhouse gases Renewable energy sources
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/5817 , vital:29399
- Description: Energy plays a vital role in socio-economic development and raising living standards of human beings. The overreliance on fossil fuels results in the depletion of fossil fuels as well as environmental pollution from the green-house gases that result from the use of fossil fuels. Biomass feedstock are able to ameliorate this situation by utilizing the CO2 that has been used by plants during photosynthesis. This study investigated the suitability of the three garden grass species (Chloris gayana, Cynodon dactylon and Pennisetum clandestum) as biomass feedstock for gasification purposes. The three garden grass species were collected at the Alice Campus of the University of Fort Hare. These grass species were characterized using elemental analyser (CHNS), FT-IR, EDX and TGA. The Activation energy (Ea) of the three grass species were 48.22 kJ/mol for P. clandestum, 36.8 kJ/mol for C. gayana and 258 kJ/mol for C. dactylon. Of the three grass species, C. gayana had the lowest Activation energy of 36.8 kJ/mol and also had the highest maximum efficiency of 69 percent compared to 65.3 percent for P. clandestum and 63.5 percent for C. dactylon. Actual gasification was not carried out but the results on maximum efficiency were obtained from computer simulation of gasification.
- Full Text:
- Date Issued: 2016
- Authors: Mkosi, Lungisa
- Date: 2016
- Subjects: Biomass energy Greenhouse gases Renewable energy sources
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/5817 , vital:29399
- Description: Energy plays a vital role in socio-economic development and raising living standards of human beings. The overreliance on fossil fuels results in the depletion of fossil fuels as well as environmental pollution from the green-house gases that result from the use of fossil fuels. Biomass feedstock are able to ameliorate this situation by utilizing the CO2 that has been used by plants during photosynthesis. This study investigated the suitability of the three garden grass species (Chloris gayana, Cynodon dactylon and Pennisetum clandestum) as biomass feedstock for gasification purposes. The three garden grass species were collected at the Alice Campus of the University of Fort Hare. These grass species were characterized using elemental analyser (CHNS), FT-IR, EDX and TGA. The Activation energy (Ea) of the three grass species were 48.22 kJ/mol for P. clandestum, 36.8 kJ/mol for C. gayana and 258 kJ/mol for C. dactylon. Of the three grass species, C. gayana had the lowest Activation energy of 36.8 kJ/mol and also had the highest maximum efficiency of 69 percent compared to 65.3 percent for P. clandestum and 63.5 percent for C. dactylon. Actual gasification was not carried out but the results on maximum efficiency were obtained from computer simulation of gasification.
- Full Text:
- Date Issued: 2016