Development of bio-based xylan composites for food packaging applications
- Authors: Naidu, Darrel Sarvesh
- Date: 2020
- Subjects: Xylanases
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/48544 , vital:40886
- Description: Currently a large number of chemicals and plastics are produced from petroleum-based resources. However, due to the concerns surrounding the depletion of petroleum resources and growing carbon emissions, there is a desire to produce chemicals and plastics from renewable and carbon natural sources. Lignocellulosic biomass (biomass consisting of cellulose, lignin and hemicellulose) is the most common biomass on earth and is renewable and carbon neutral. Of the three main constituents of lignocellulosic biomass, hemicellulose is composed of a mixture of sugars which can be converted into chemicals and plastics. The most common form of hemicellulose found in nature is xylan. This study is aimed at extracting xylan from maize stalk waste residues and the development of xylan films with properties that are suitable for food packaging applications. Xylan was extracted from maize stalk waste residues using an alkaline pre-treatment method. The effects of bleaching conditions (time, temperature and bleach concentration) prior to alkaline treatment on the yield and purity of xylan extracted was studied using a Box-Behnken experimental design. It was observed that the experimental conditions tested had no effect on the yield of the xylan extracted but the bleach concentration had a significant effect on the purity of the xylan extracted. The samples with the lowest lignin content were found to be the samples treated with 3wt% bleach prior to alkaline pre-treatment. One of the main disadvantages of xylan is that it has poor film forming properties, a method of overcoming this is to combine it with another abundantly available biopolymer that has good film forming properties, such as alginate. The effect of xylan, alginate and glycerol content on the mechanical, thermal, moisture uptake and water barrier properties of the films were investigated. It was observed that with an increase in the alginate content there was an increase in the tensile strength and Young’s modulus of the films, whereas the water vapour permeability (WVP) of the films decreased. This was attributed to the greater cohesion between alginate polymer chains compared to the cohesion between xylan polymer chains. The xylanalginate films exhibited better optical and water sorption properties at higher xylan content. In order to improve the inherently poor mechanical and barrier properties of the xylan-alginate films, bentonite and halloysite were incorporated into the films. It was found that 5wt% incorporation of either bentonite or halloysite resulted in a 49% decrease of the WVP, which was attributed to water vapour impermeable nature of the silicate layers that make up both clays. The incorporation of the clays into the xylan-alginate matrix resulted in a significant
- Full Text:
- Date Issued: 2020
- Authors: Naidu, Darrel Sarvesh
- Date: 2020
- Subjects: Xylanases
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/48544 , vital:40886
- Description: Currently a large number of chemicals and plastics are produced from petroleum-based resources. However, due to the concerns surrounding the depletion of petroleum resources and growing carbon emissions, there is a desire to produce chemicals and plastics from renewable and carbon natural sources. Lignocellulosic biomass (biomass consisting of cellulose, lignin and hemicellulose) is the most common biomass on earth and is renewable and carbon neutral. Of the three main constituents of lignocellulosic biomass, hemicellulose is composed of a mixture of sugars which can be converted into chemicals and plastics. The most common form of hemicellulose found in nature is xylan. This study is aimed at extracting xylan from maize stalk waste residues and the development of xylan films with properties that are suitable for food packaging applications. Xylan was extracted from maize stalk waste residues using an alkaline pre-treatment method. The effects of bleaching conditions (time, temperature and bleach concentration) prior to alkaline treatment on the yield and purity of xylan extracted was studied using a Box-Behnken experimental design. It was observed that the experimental conditions tested had no effect on the yield of the xylan extracted but the bleach concentration had a significant effect on the purity of the xylan extracted. The samples with the lowest lignin content were found to be the samples treated with 3wt% bleach prior to alkaline pre-treatment. One of the main disadvantages of xylan is that it has poor film forming properties, a method of overcoming this is to combine it with another abundantly available biopolymer that has good film forming properties, such as alginate. The effect of xylan, alginate and glycerol content on the mechanical, thermal, moisture uptake and water barrier properties of the films were investigated. It was observed that with an increase in the alginate content there was an increase in the tensile strength and Young’s modulus of the films, whereas the water vapour permeability (WVP) of the films decreased. This was attributed to the greater cohesion between alginate polymer chains compared to the cohesion between xylan polymer chains. The xylanalginate films exhibited better optical and water sorption properties at higher xylan content. In order to improve the inherently poor mechanical and barrier properties of the xylan-alginate films, bentonite and halloysite were incorporated into the films. It was found that 5wt% incorporation of either bentonite or halloysite resulted in a 49% decrease of the WVP, which was attributed to water vapour impermeable nature of the silicate layers that make up both clays. The incorporation of the clays into the xylan-alginate matrix resulted in a significant
- Full Text:
- Date Issued: 2020
Development of MOVPE-grown InAsSb for barrier diode applications
- Authors: Dobson, Stephen R
- Date: 2020
- Subjects: Gallium arsenide semiconductors , Electronics
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/49071 , vital:41598
- Description: In this study, layers of GaSb, InAs and InAsSb are grown by metalorganic vapour phase epitaxy and characterised. Growth is conducted using the precursors of trimethylgallium, trimethylindium, trimethylantimony and tertiarybutylarsine. Focus is then placed on the characterisation of the materials, carried out by the techniques of X-ray diffraction, photoluminescence spectroscopy, Hall measurements and photocurrent spectroscopy. It is observed that V/III ratio plays a vital role in the growth of the GaSb and InAsSb layers. Epilayers of GaSb showed best crystalline quality when a V/III ratio of 1.2 was used at a growth temperature of 600 °C and a cell pressure of 600 Torr. Resultant Hall measurements indicated p-type GaSb. The Hall carrier concentrations of the p-type GaSb samples were analyzed considering electrical neutrality conditions and found to be highly compensated with evidence of band impurity conduction at low measurement temperatures. Both the donor and acceptor concentrations were determined to be of the order of 1016 cm−3 for all samples. For low temperature (< 150 K) a monovalent acceptor concentration is calculated to have an activation energy at approximately 20 meV. At high temperature (> 150 K) a divalent acceptor is extracted with an activation energy varying between samples based on compensation in a range of 90 meV to 70 meV. Photoluminescence measurements show four peaks with recombination mechanisms linked to the native acceptor identified in literature as either the gallium antisite and/or vacant gallium site. A fifth peak observed is attributed to the longitudinal phonon of the native acceptor. InAs and InAsSb epilayer are all grown at a temperature of 600 °C and cell pressure of 600 Torr. InAs is grown at a V/III ratio of 9.5 on GaAs substrate. Photoluminescence of the InAs layer shows two distinct peaks, one of which is an extrinsic band to band recombination. The other is attributed to free electron to acceptor or a donor-acceptor pair transition. An additional weak peak is also observed which is assigned to the longitudinal phonon of the band to band. InAsSb growth was conducted under a range of V/III ratios of 4.8 to 5, with a vapour phase composition of 0.4 to 0.435. Structural analysis via X-ray diffraction showed a 6 % to 12 % solid antimony content. Photoluminescence exhibited a single broad peak for all samples, with extended band tails. Temperature and power dependant analysis of luminescence indicated a convolution of extrinsic band to tail and band to band recombinations. Hall measurements indicated the InAsSb was n-type material with an apparent measured maximum mobility at 120 K of 9.5 × 103 cm2/V.s. and a room temperature apparent mobility of 7.5 × 103 cm2/V.s. Analysis of hall results using a two-layer model calculated a true bulk mobility of the epilayer at room temperature with an increased value of 15.4 × 103 cm2/V.s. The two-layer model details the effects of the surface conduction. From photoconductivity measurements and further analysis a resultant effective lifetime, at room temperature, was found to be on same order of magnitude as that of InAs materials. Application of a single Einstein oscillator extrapolated 0 K energy gaps for two samples of solid Sb contents of 6 % and 12 %, of 354 meV and 332 meV, respectively. Finally consideration was given to the growth of aluminium containing compounds, particularly AlGaSb. Multiple phases were observed under scanning electron microscope showing growth of GaSb regions surrounded by amorphous solid aluminium and/or aluminium oxide phases. The failure of the aluminium to incorporate into the desired crystal structure is speculated to be due to impure precursor introducing oxygen into the films. Additionally, the effectiveness of the gallium precursor compared to the aluminium precursor in helping the removal of the methyl groups at the growth surface, could also promote a preference for GaSb growth.
- Full Text:
- Date Issued: 2020
- Authors: Dobson, Stephen R
- Date: 2020
- Subjects: Gallium arsenide semiconductors , Electronics
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/49071 , vital:41598
- Description: In this study, layers of GaSb, InAs and InAsSb are grown by metalorganic vapour phase epitaxy and characterised. Growth is conducted using the precursors of trimethylgallium, trimethylindium, trimethylantimony and tertiarybutylarsine. Focus is then placed on the characterisation of the materials, carried out by the techniques of X-ray diffraction, photoluminescence spectroscopy, Hall measurements and photocurrent spectroscopy. It is observed that V/III ratio plays a vital role in the growth of the GaSb and InAsSb layers. Epilayers of GaSb showed best crystalline quality when a V/III ratio of 1.2 was used at a growth temperature of 600 °C and a cell pressure of 600 Torr. Resultant Hall measurements indicated p-type GaSb. The Hall carrier concentrations of the p-type GaSb samples were analyzed considering electrical neutrality conditions and found to be highly compensated with evidence of band impurity conduction at low measurement temperatures. Both the donor and acceptor concentrations were determined to be of the order of 1016 cm−3 for all samples. For low temperature (< 150 K) a monovalent acceptor concentration is calculated to have an activation energy at approximately 20 meV. At high temperature (> 150 K) a divalent acceptor is extracted with an activation energy varying between samples based on compensation in a range of 90 meV to 70 meV. Photoluminescence measurements show four peaks with recombination mechanisms linked to the native acceptor identified in literature as either the gallium antisite and/or vacant gallium site. A fifth peak observed is attributed to the longitudinal phonon of the native acceptor. InAs and InAsSb epilayer are all grown at a temperature of 600 °C and cell pressure of 600 Torr. InAs is grown at a V/III ratio of 9.5 on GaAs substrate. Photoluminescence of the InAs layer shows two distinct peaks, one of which is an extrinsic band to band recombination. The other is attributed to free electron to acceptor or a donor-acceptor pair transition. An additional weak peak is also observed which is assigned to the longitudinal phonon of the band to band. InAsSb growth was conducted under a range of V/III ratios of 4.8 to 5, with a vapour phase composition of 0.4 to 0.435. Structural analysis via X-ray diffraction showed a 6 % to 12 % solid antimony content. Photoluminescence exhibited a single broad peak for all samples, with extended band tails. Temperature and power dependant analysis of luminescence indicated a convolution of extrinsic band to tail and band to band recombinations. Hall measurements indicated the InAsSb was n-type material with an apparent measured maximum mobility at 120 K of 9.5 × 103 cm2/V.s. and a room temperature apparent mobility of 7.5 × 103 cm2/V.s. Analysis of hall results using a two-layer model calculated a true bulk mobility of the epilayer at room temperature with an increased value of 15.4 × 103 cm2/V.s. The two-layer model details the effects of the surface conduction. From photoconductivity measurements and further analysis a resultant effective lifetime, at room temperature, was found to be on same order of magnitude as that of InAs materials. Application of a single Einstein oscillator extrapolated 0 K energy gaps for two samples of solid Sb contents of 6 % and 12 %, of 354 meV and 332 meV, respectively. Finally consideration was given to the growth of aluminium containing compounds, particularly AlGaSb. Multiple phases were observed under scanning electron microscope showing growth of GaSb regions surrounded by amorphous solid aluminium and/or aluminium oxide phases. The failure of the aluminium to incorporate into the desired crystal structure is speculated to be due to impure precursor introducing oxygen into the films. Additionally, the effectiveness of the gallium precursor compared to the aluminium precursor in helping the removal of the methyl groups at the growth surface, could also promote a preference for GaSb growth.
- Full Text:
- Date Issued: 2020
Development of Tio 2 nanostructure arrays for photonic extraction of hydrogen gas
- Authors: Suliali, Nyasha Joseph
- Date: 2020
- Subjects: Nanostructures , Nanostructured materials Hydrogen
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/49314 , vital:41620
- Description: Amid the energy crisis of the 21st century, renewable energy is a thriving field of study, light harvesting materials being a central theme due to the abundance of solar energy. Nanostructured TiO2 is the most studied photocatalysis material, since the discovery of its energy harvesting properties by Fujishima and Honda in 1972. Environmentally friendly products such as hydrogen fuel, can be produced using TiO2 due to its non-toxicity, chemical stability and photocatalytic activity. The surprising aspect of this important material is that it can be prepared using cost-effective methods such as hydrothermal synthesis, solution gelation and anodic oxidation. This research focused on the three key elements required to develop TiO2 photoelectrodes i.e. the deposition of Ti films on transparent substrates, a thorough analysis of the chemistry of the anodic oxidation process and the development of the TiO2 thin films. Glass substrates that have Ti films are the base component for TiO2 photoelectrode production. Ti films with thicknesses up to 4 μm, were developed on commercial F-doped SnO2 (FTO) glass substrates using high-power impulse magnetron sputtering (HiPIMS). The sputter deposition experiments were performed in the 1 to 8 kW range at a substrate temperature of 500 °C and Ar pressure of 400 mPa. At higher powers, thicker films were deposited, resulting in increased intensity of Xray-diffraction peaks. However, on comparing the XRD patterns, the (001) peak outgrew the rest regardless of thickness of the film. The deposition process therefore favoured orientation of most of the α-Ti phase crystallites with the [001] axis perpendicular to the substrate surface. Surface roughness results were interesting, showing a non-linear dependence of the surface roughness on HiPIMS pulse energy in the 1 to 8 kW range. The surface roughness is highest at the starting deposition power of 1450 W and reduces to a minimum at 4500 W. From this minimum, it increases to its second highest value at 7900 W. From this data, the parameters required to produce Ti films of lowest surface roughness, for deposition on commercial Technistro® FTO glass, were deduced at the inflection point, where the deposition power was 4500 W. The surface roughness obtained is a critical result for the anodic production of quality TiO2 photoelectrodes, which if high, leads to uneven etching, thus irregular and inefficient photoelectrodes. Direct current magnetron sputtering was also carried out in the 1 to 5 kW range to obtain ratios of power-normalised growth rates of the Ti films. This investigation provided the Ti films on FTO glass, the transparent, conductive substrates which were used to develop TiO2 photoelectrodes. To elucidate the chemistry of anodic oxidation of Ti, a mathematical model of the anodic current density, which had not been reported at the time of its publication, was developed. The technique, a highlight of this research, is a predictive numerical computation of the instantaneous quantities of species that participate in the anodization process. From eleven chemical reactions, 14 first order ordinary differential equations were compiled using the principles of chemical reaction kinetics. The pattern, transient behaviour and response to anodization parameters of the current density signal, were successfully predicted. Strong agreement between the model and measurements was demonstrated in seven experiments. The results confirm that the current density signal is a numerical integral of the kinetics of redox reactions of water. The bulk of this research was on the development of TiO2 nanotubular arrays on Ti foil substrates and Ti films on FTO glass. TiO2 films with well-defined tubular structures were synthesised. The films were developed in anhydrous, polar organic hosts with water and etching agents in the range of 10 V to 70 V. The control of geometrical properties of the tubes such as the length, pore diameter, wall thickness, tube separation and number of nanotubes per unit area was demonstrated. Anatase only and mixed anatase-rutile phase compositions were obtained at different annealing temperatures. Nanotubes with diameters as small as 20 nm and thickness as high as 29 μm were produced. Apart from an increase in nanotube thickness, a decrease in distance between nanotubes grown in diethylene glycol was observed at longer anodization times. Studies of the effects of anodization parameters on the current density measured, morphological and crystallographic properties of the nanotube films were conducted in three main investigations. The first was the study of the effect of anodization parameters on current density. Besides the obvious increase of current density with anodic voltage, the first steady state of the growth process was found to depend on the NH4F concentration. The second investigation focused on the effect of accelerated growth of TiO2 nanotubular films. In the study, 9 μm-thick nanotube films were synthesised at twice the growth rate of a 9 μm-thick control sample. The array obtained by accelerated growth had distinguishable nanotubes, however, the morphological quality was reduced. The third investigation demonstrates the control of the number of nanotubes per unit area. By varying the etchant content, the anodic voltage and the viscosity of the electrolyte host, various distributions were obtained. The research ends with a photoelectrochemical application: measurement on photocurrents generated in a two-electrode setup. The photocurrent densities measured in the off and on conditions were 30 nA/cm2 and 2.57 μA/cm2, respectively, demonstrating photoactivity of the developed films.
- Full Text:
- Date Issued: 2020
- Authors: Suliali, Nyasha Joseph
- Date: 2020
- Subjects: Nanostructures , Nanostructured materials Hydrogen
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/49314 , vital:41620
- Description: Amid the energy crisis of the 21st century, renewable energy is a thriving field of study, light harvesting materials being a central theme due to the abundance of solar energy. Nanostructured TiO2 is the most studied photocatalysis material, since the discovery of its energy harvesting properties by Fujishima and Honda in 1972. Environmentally friendly products such as hydrogen fuel, can be produced using TiO2 due to its non-toxicity, chemical stability and photocatalytic activity. The surprising aspect of this important material is that it can be prepared using cost-effective methods such as hydrothermal synthesis, solution gelation and anodic oxidation. This research focused on the three key elements required to develop TiO2 photoelectrodes i.e. the deposition of Ti films on transparent substrates, a thorough analysis of the chemistry of the anodic oxidation process and the development of the TiO2 thin films. Glass substrates that have Ti films are the base component for TiO2 photoelectrode production. Ti films with thicknesses up to 4 μm, were developed on commercial F-doped SnO2 (FTO) glass substrates using high-power impulse magnetron sputtering (HiPIMS). The sputter deposition experiments were performed in the 1 to 8 kW range at a substrate temperature of 500 °C and Ar pressure of 400 mPa. At higher powers, thicker films were deposited, resulting in increased intensity of Xray-diffraction peaks. However, on comparing the XRD patterns, the (001) peak outgrew the rest regardless of thickness of the film. The deposition process therefore favoured orientation of most of the α-Ti phase crystallites with the [001] axis perpendicular to the substrate surface. Surface roughness results were interesting, showing a non-linear dependence of the surface roughness on HiPIMS pulse energy in the 1 to 8 kW range. The surface roughness is highest at the starting deposition power of 1450 W and reduces to a minimum at 4500 W. From this minimum, it increases to its second highest value at 7900 W. From this data, the parameters required to produce Ti films of lowest surface roughness, for deposition on commercial Technistro® FTO glass, were deduced at the inflection point, where the deposition power was 4500 W. The surface roughness obtained is a critical result for the anodic production of quality TiO2 photoelectrodes, which if high, leads to uneven etching, thus irregular and inefficient photoelectrodes. Direct current magnetron sputtering was also carried out in the 1 to 5 kW range to obtain ratios of power-normalised growth rates of the Ti films. This investigation provided the Ti films on FTO glass, the transparent, conductive substrates which were used to develop TiO2 photoelectrodes. To elucidate the chemistry of anodic oxidation of Ti, a mathematical model of the anodic current density, which had not been reported at the time of its publication, was developed. The technique, a highlight of this research, is a predictive numerical computation of the instantaneous quantities of species that participate in the anodization process. From eleven chemical reactions, 14 first order ordinary differential equations were compiled using the principles of chemical reaction kinetics. The pattern, transient behaviour and response to anodization parameters of the current density signal, were successfully predicted. Strong agreement between the model and measurements was demonstrated in seven experiments. The results confirm that the current density signal is a numerical integral of the kinetics of redox reactions of water. The bulk of this research was on the development of TiO2 nanotubular arrays on Ti foil substrates and Ti films on FTO glass. TiO2 films with well-defined tubular structures were synthesised. The films were developed in anhydrous, polar organic hosts with water and etching agents in the range of 10 V to 70 V. The control of geometrical properties of the tubes such as the length, pore diameter, wall thickness, tube separation and number of nanotubes per unit area was demonstrated. Anatase only and mixed anatase-rutile phase compositions were obtained at different annealing temperatures. Nanotubes with diameters as small as 20 nm and thickness as high as 29 μm were produced. Apart from an increase in nanotube thickness, a decrease in distance between nanotubes grown in diethylene glycol was observed at longer anodization times. Studies of the effects of anodization parameters on the current density measured, morphological and crystallographic properties of the nanotube films were conducted in three main investigations. The first was the study of the effect of anodization parameters on current density. Besides the obvious increase of current density with anodic voltage, the first steady state of the growth process was found to depend on the NH4F concentration. The second investigation focused on the effect of accelerated growth of TiO2 nanotubular films. In the study, 9 μm-thick nanotube films were synthesised at twice the growth rate of a 9 μm-thick control sample. The array obtained by accelerated growth had distinguishable nanotubes, however, the morphological quality was reduced. The third investigation demonstrates the control of the number of nanotubes per unit area. By varying the etchant content, the anodic voltage and the viscosity of the electrolyte host, various distributions were obtained. The research ends with a photoelectrochemical application: measurement on photocurrents generated in a two-electrode setup. The photocurrent densities measured in the off and on conditions were 30 nA/cm2 and 2.57 μA/cm2, respectively, demonstrating photoactivity of the developed films.
- Full Text:
- Date Issued: 2020
Diversion Programmes and Empowerment: A Case Study of Young Offenders’ Experiences in the Buffalo City Metropolitan and Amathole District Municipalities in the Eastern Cape Province of South Africa
- Authors: Mangwiro, Vongai P
- Date: 2020
- Subjects: Social work with criminals Social work with juvenile delinquents
- Language: English
- Type: Thesis , Doctoral , PhD (Social Work)
- Identifier: http://hdl.handle.net/10353/18031 , vital:42006
- Description: Crime amongst the young in South Africa has been high since the attainment of democracy in 1994. Diversion programmes were established through the National Framework Chid Justice Act of 2008, as part of a plethora of measures to curb the ever spiralling problem of crime amongst the youth. The purpose of this thesis was to investigate the experiences of young offenders regarding their empowerment vis-à-vis diversion programmes in the Buffalo City Metropolitan and Amathole District Municipalities in the Eastern Cape Province. Underpinned by the Empowerment and Social Control Theories, the study adopted a qualitative research paradigm and used focus group discussions and in-depth interviews amongst thirty-five young offenders and five social workers, who work as probation officers at NICRO, to collect data, which was analysed using thematic analysis. The major findings indicated that diversion programmes are effective in reducing the number of children who commit crimes in these two municipalities and in influencing their behavioural change, resulting in fewer chances of re-offending. The Life Skills Programme was identified as the most effective programme, in comparison to the other programmes, such as the Community pre-trial Service Programme, in changing the behaviour of the young offenders, as it helps them to discover themselves; learn respect for the self and others in the community; help with family and community reintegration; and helps them focus on who they want to be in the future. In spite of such positive attributes for the diversion programmes, the study observed that there are challenges being faced by the implementing organisation, NICRO. These include high caseloads; lack of support from the probation officers who refer young offenders; limited support from parents; paucity of financial resources; lack of transport; poor v coordination from the courts; and delays in the implementation of some accredited but not credited programmes. Overall, the study concluded that diversion programmes in the Buffalo city Metropolitan and Amathole district municipalities in the Eastern Cape suffer due to weak partnerships between different organisations and stakeholders that are supposed to complement the efforts of the judiciary. From the research findings above, it is recommended that the Child Justice System should promote a multi-sectored approach in order to restore and reunify all the stakeholders, working with children in conflict with the law. This adds more roles and responsibilities for the various stakeholders, such as the Department of Justice and Department of Social development. Furthermore, there is a need to increase the monitoring and evaluation of diversion programmes to advance accountability and improve effectiveness; and there is a need to enhance the efficiency of accrediting authorities to timeously accredit other diversion programmes that, so far, have not yet been accredited, but may be useful in empowering young offenders. Therefore, the study proposes an extension of the framework with additions of strategies to support diversion programmes at NICRO, through a stakeholder extension to the model allocating more roles and responsibilities for stakeholders in the Child Justice system, in order for diversion programmes to effectively achieve desired goals.
- Full Text:
- Date Issued: 2020
- Authors: Mangwiro, Vongai P
- Date: 2020
- Subjects: Social work with criminals Social work with juvenile delinquents
- Language: English
- Type: Thesis , Doctoral , PhD (Social Work)
- Identifier: http://hdl.handle.net/10353/18031 , vital:42006
- Description: Crime amongst the young in South Africa has been high since the attainment of democracy in 1994. Diversion programmes were established through the National Framework Chid Justice Act of 2008, as part of a plethora of measures to curb the ever spiralling problem of crime amongst the youth. The purpose of this thesis was to investigate the experiences of young offenders regarding their empowerment vis-à-vis diversion programmes in the Buffalo City Metropolitan and Amathole District Municipalities in the Eastern Cape Province. Underpinned by the Empowerment and Social Control Theories, the study adopted a qualitative research paradigm and used focus group discussions and in-depth interviews amongst thirty-five young offenders and five social workers, who work as probation officers at NICRO, to collect data, which was analysed using thematic analysis. The major findings indicated that diversion programmes are effective in reducing the number of children who commit crimes in these two municipalities and in influencing their behavioural change, resulting in fewer chances of re-offending. The Life Skills Programme was identified as the most effective programme, in comparison to the other programmes, such as the Community pre-trial Service Programme, in changing the behaviour of the young offenders, as it helps them to discover themselves; learn respect for the self and others in the community; help with family and community reintegration; and helps them focus on who they want to be in the future. In spite of such positive attributes for the diversion programmes, the study observed that there are challenges being faced by the implementing organisation, NICRO. These include high caseloads; lack of support from the probation officers who refer young offenders; limited support from parents; paucity of financial resources; lack of transport; poor v coordination from the courts; and delays in the implementation of some accredited but not credited programmes. Overall, the study concluded that diversion programmes in the Buffalo city Metropolitan and Amathole district municipalities in the Eastern Cape suffer due to weak partnerships between different organisations and stakeholders that are supposed to complement the efforts of the judiciary. From the research findings above, it is recommended that the Child Justice System should promote a multi-sectored approach in order to restore and reunify all the stakeholders, working with children in conflict with the law. This adds more roles and responsibilities for the various stakeholders, such as the Department of Justice and Department of Social development. Furthermore, there is a need to increase the monitoring and evaluation of diversion programmes to advance accountability and improve effectiveness; and there is a need to enhance the efficiency of accrediting authorities to timeously accredit other diversion programmes that, so far, have not yet been accredited, but may be useful in empowering young offenders. Therefore, the study proposes an extension of the framework with additions of strategies to support diversion programmes at NICRO, through a stakeholder extension to the model allocating more roles and responsibilities for stakeholders in the Child Justice system, in order for diversion programmes to effectively achieve desired goals.
- Full Text:
- Date Issued: 2020
Dynamics of stimulated luminescence in natural quartz: Thermoluminescence and phototransferred thermoluminescence
- Authors: Folley, Damilola Esther
- Date: 2020
- Subjects: Thermoluminescence , Quartz
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/146255 , vital:38509
- Description: Natural quartz has remained an important mineral that is of topical interest in luminescence and dosimetry-related research. We investigate the dynamics of stimulated luminescence on this material through thermoluminescence (TL) and phototransferred thermoluminescence (PTTL). Measurements were made on unannealed natural quartz as well as quartz annealed at 800 and 1000̊C. The samples were annealed for 10 minutes and for 1 hour. The material, in its un- and annealed state has its main peak between 68 and 72̊C when measured at 1Cs ̃1 after a dose of 50 Gy. A study of dosimetric features and kinetic analysis was carried out on two prominent peaks, peak I and III for all the samples. The peaks show a sublinear dose response for irradiation doses between 10 and 300 Gy. Kinetic analysis shows that peak I is a first-order peak and peak III a general-order peak. Interestingly, we observe for peak I for the sample annealed at 800̊C for 1 hour an inverse thermal quenching behaviour. We demonstrate that a peak affected with an inverse thermal quenching-like behaviour can still show effect of thermal quenching when the dose the sample is irradiated to is significantly reduced. We ascribe the apparent dependence of thermal quenching on dose to competition between radiative and non-radiative transitions at the recombination centre. Peaks I, II, and III for all the samples were reproduced under phototransfer when the peaks, initially removed by preheating to a certain temperature are exposed to 470 and 525 nm light. The infuence of duration of illumination on the PTTL intensity of these peaks corresponding to various preheating temperatures is modelled using coupled first-order dfferential equations. The model is based on systems of acceptors and donors whose number and role depends on preheating temperature
- Full Text:
- Date Issued: 2020
- Authors: Folley, Damilola Esther
- Date: 2020
- Subjects: Thermoluminescence , Quartz
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/146255 , vital:38509
- Description: Natural quartz has remained an important mineral that is of topical interest in luminescence and dosimetry-related research. We investigate the dynamics of stimulated luminescence on this material through thermoluminescence (TL) and phototransferred thermoluminescence (PTTL). Measurements were made on unannealed natural quartz as well as quartz annealed at 800 and 1000̊C. The samples were annealed for 10 minutes and for 1 hour. The material, in its un- and annealed state has its main peak between 68 and 72̊C when measured at 1Cs ̃1 after a dose of 50 Gy. A study of dosimetric features and kinetic analysis was carried out on two prominent peaks, peak I and III for all the samples. The peaks show a sublinear dose response for irradiation doses between 10 and 300 Gy. Kinetic analysis shows that peak I is a first-order peak and peak III a general-order peak. Interestingly, we observe for peak I for the sample annealed at 800̊C for 1 hour an inverse thermal quenching behaviour. We demonstrate that a peak affected with an inverse thermal quenching-like behaviour can still show effect of thermal quenching when the dose the sample is irradiated to is significantly reduced. We ascribe the apparent dependence of thermal quenching on dose to competition between radiative and non-radiative transitions at the recombination centre. Peaks I, II, and III for all the samples were reproduced under phototransfer when the peaks, initially removed by preheating to a certain temperature are exposed to 470 and 525 nm light. The infuence of duration of illumination on the PTTL intensity of these peaks corresponding to various preheating temperatures is modelled using coupled first-order dfferential equations. The model is based on systems of acceptors and donors whose number and role depends on preheating temperature
- Full Text:
- Date Issued: 2020
Ecological assessment of a temperate river system using biomonitoring techniques: a case study of the Bloukrans River system, South Africa
- Authors: Magadze, Tinotenda
- Date: 2020
- Subjects: Bloukrans River , Ecological assessment (Biology) -- South Africa , Stream ecology -- South Africa , Rivers -- Environmental aspects -- South Africa , Benthic animals -- Effect of human beings on -- South Africa , Water quality biological assessment -- South Africa , Diatoms -- South Africa -- Data processing
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/142933 , vital:38177
- Description: Escalating pressures from growing human populations and environmental impacts increasingly imperil freshwater ecosystems. The Bloukrans River, which drains an urbanised and agricultural catchment in the Eastern Cape province of South Africa, is no exception. Detailed knowledge of the structure and function of the aquatic ecosystems is required in order to create models and matrices that predict, guide assessment and direct intervention on ecological integrity and water quality management in these systems. The main objectives of this research were to: examine the effects of urbanization on the benthic macroinvertebrate functional feeding guild structure among different stream orders; determine if benthic diatoms can be used as effective and reliable indicators of ionic composition and conductivity in different stream order categories and finally; to evaluate the applicability of the South African Diatom Index (SADI) and other indices in the Eastern Cape region of South Africa. Field studies were carried out to explore temporal patterns in community structure (macroinvertebrates and diatoms) and ecosystem function related to land-use patterns, instream habitat availability, and water quality parameters in the Bloukrans River system across four study periods: February (summer) and July (winter) 2016 and February (summer) and May/July (winter) 2018. The study was conducted along a gradient of impacts from less impacted agricultural headwaters to highly impacted urban sites located immediately downstream of the city of Makhanda. Macroinvertebrates were separated into functional feeding groups (FFGs) (i.e. collector-gatherer, collector-filterer, scraper, shredder, and predator) which were then used to assess the effects of selected physico-chemical variables and riparian zone condition on FFG organization. Collector-gatherers were the most abundant in the Bloukrans River and represented 71.3 % of the macroinvertebrate assemblages. Stream order 1species such as Nitzschia palea, Gomphonema parvulum, Tryblionella apiculata, Diploneis vulgaris and Staurosira elliptica. Multivariate analysis (Canonical correspondence analysis (CCA)) indicated that differences in diatom community assemblages were best explained by calcium, magnesium, pH, phosphate, nitrate, dissolved oxygen, sediment nitrate, conductivity and salinity. These results indicate that diatoms can be used as bioindicators for monitoring highly impacted river systems and to also further examine pollution gradients and impacts of specific/point pollution sources. In order to further test the application of diatom indices, nine sites with contrasting water quality were sampled along the length river system in February, May and July 2018. Diatom-based indices incorporated in OMNIDIA software were applied to assess the integrity of the water quality as indicated by diatom communities. For comparative purposes, several foreign indices (e.g. the trophic diatom index (TDI), the percentage pollution-tolerant valves (%PTV), biological diatom index (BDI)) and the South African Diatom Index (SADI) were used in the study. From the results, the Percentage Pollution-Tolerant Valves (%PTV) of most urban sites in the Bloukrans River was above the 20% limit indicating the presence of organic pollutants. Although the foreign diatom indices were applicable in the study, the SADI had significant correlations with most water quality variables (p < 0.05) compared to other indices such as Watanabe Index (WAT), Biological Index of Water Quality Trophic Index (BIWQ) and Trophic Index (TI)). These results support wider use of the SADI as an indicator of water quality conditions in South African river systems. Finally, the observed variations in diatom community structure and composition as a result of changes in water quality were broadly in agreement with the results of macroinvertebrate FFG structure indicating that the two biological indicators can, and should, be used as complementary techniques in the biomonitoring of rivers and streams in South Africa.
- Full Text:
- Date Issued: 2020
- Authors: Magadze, Tinotenda
- Date: 2020
- Subjects: Bloukrans River , Ecological assessment (Biology) -- South Africa , Stream ecology -- South Africa , Rivers -- Environmental aspects -- South Africa , Benthic animals -- Effect of human beings on -- South Africa , Water quality biological assessment -- South Africa , Diatoms -- South Africa -- Data processing
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/142933 , vital:38177
- Description: Escalating pressures from growing human populations and environmental impacts increasingly imperil freshwater ecosystems. The Bloukrans River, which drains an urbanised and agricultural catchment in the Eastern Cape province of South Africa, is no exception. Detailed knowledge of the structure and function of the aquatic ecosystems is required in order to create models and matrices that predict, guide assessment and direct intervention on ecological integrity and water quality management in these systems. The main objectives of this research were to: examine the effects of urbanization on the benthic macroinvertebrate functional feeding guild structure among different stream orders; determine if benthic diatoms can be used as effective and reliable indicators of ionic composition and conductivity in different stream order categories and finally; to evaluate the applicability of the South African Diatom Index (SADI) and other indices in the Eastern Cape region of South Africa. Field studies were carried out to explore temporal patterns in community structure (macroinvertebrates and diatoms) and ecosystem function related to land-use patterns, instream habitat availability, and water quality parameters in the Bloukrans River system across four study periods: February (summer) and July (winter) 2016 and February (summer) and May/July (winter) 2018. The study was conducted along a gradient of impacts from less impacted agricultural headwaters to highly impacted urban sites located immediately downstream of the city of Makhanda. Macroinvertebrates were separated into functional feeding groups (FFGs) (i.e. collector-gatherer, collector-filterer, scraper, shredder, and predator) which were then used to assess the effects of selected physico-chemical variables and riparian zone condition on FFG organization. Collector-gatherers were the most abundant in the Bloukrans River and represented 71.3 % of the macroinvertebrate assemblages. Stream order 1species such as Nitzschia palea, Gomphonema parvulum, Tryblionella apiculata, Diploneis vulgaris and Staurosira elliptica. Multivariate analysis (Canonical correspondence analysis (CCA)) indicated that differences in diatom community assemblages were best explained by calcium, magnesium, pH, phosphate, nitrate, dissolved oxygen, sediment nitrate, conductivity and salinity. These results indicate that diatoms can be used as bioindicators for monitoring highly impacted river systems and to also further examine pollution gradients and impacts of specific/point pollution sources. In order to further test the application of diatom indices, nine sites with contrasting water quality were sampled along the length river system in February, May and July 2018. Diatom-based indices incorporated in OMNIDIA software were applied to assess the integrity of the water quality as indicated by diatom communities. For comparative purposes, several foreign indices (e.g. the trophic diatom index (TDI), the percentage pollution-tolerant valves (%PTV), biological diatom index (BDI)) and the South African Diatom Index (SADI) were used in the study. From the results, the Percentage Pollution-Tolerant Valves (%PTV) of most urban sites in the Bloukrans River was above the 20% limit indicating the presence of organic pollutants. Although the foreign diatom indices were applicable in the study, the SADI had significant correlations with most water quality variables (p < 0.05) compared to other indices such as Watanabe Index (WAT), Biological Index of Water Quality Trophic Index (BIWQ) and Trophic Index (TI)). These results support wider use of the SADI as an indicator of water quality conditions in South African river systems. Finally, the observed variations in diatom community structure and composition as a result of changes in water quality were broadly in agreement with the results of macroinvertebrate FFG structure indicating that the two biological indicators can, and should, be used as complementary techniques in the biomonitoring of rivers and streams in South Africa.
- Full Text:
- Date Issued: 2020
Effect of increasing fossil shell flour levels on digestive and metabolic utilization, health, body weight change and wool production, and quality in Dohne-Merino wethers
- Authors: Ikusika, Olusegun Oyebade
- Date: 2020
- Subjects: Merino sheep Sheep -- Quality
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/18465 , vital:42542
- Description: The study's broad objective was to assess growth performance, blood and parasitic profiles, wool parameters, methane emission, and nutritional status of Dohne-Merino wethers fed diets supplemented with varying levels of fossil shell flour. Twenty-four Dohne-Merino wethers, averagely weighing 20.0±1.50 kg, were divided into four groups and used in this study. The effects of varying inclusion levels of fossil shell flour (FSF) (0, 2, 4, and 6 %) on feed intake, water intake, nutrient digestibility, N-retention, hematobiochemical and parasitic profiles, body condition scores, feed preference, wool parameters and methane output were determined. The influence of FSF's varying inclusion levels on fermentation parameters, in vitro true digestibility, and relative feed values were also determined. Wethers fed with 4% FSF inclusion level diet showed the highest (P<0.05) values for dry matter intake, average daily weight gain, N retention, (Nitrogen retention) and apparent digestibility of crude protein (CP), Ether Extract (EE) and Ash 6 % (P < 0.05). The urinary N and fecal N were lowest in wethers fed 4% FSF inclusion level and highest in those fed on diets without FSF (P < 0.05). Water intake was highest in wethers fed 0% FSF diet, followed by those fed on 4% and lowest in 6% FSF (P< 0.05). There was a significant increase in white blood cell counts in wethers fed on a diet with 4% and 6% FSF inclusion levels from day 10 to 100 compared to wethers fed on a diet with 0% and 2% FSF (P <0.05). Red blood cell counts also increased significantly in wethers fed on a diet containing 4% FSF, but a slight increase in wethers with 6 % FSF diet, throughout the experimental period (P < 0.05). Blood urea was highest in wethers fed 0% FSF inclusion level and lowest in 6% at day 30 to day 100. Wethers on 4% FSF diet showed an increase in blood urea from day 30 to day 100 (P < 0.05) while wethers on 0% and 2% remained unchanged (P<0.05) during this period and not different (P > 0.05) from wethers on 4% FSF as well. The total protein concentration, albumin, total bilirubin, Na, K, glucose, cholesterol, and liver enzymes were normal for wethers. However, serum creatinine level was lower in wethers fed on 4% FSF than those on 0% FSF (P < 0.01). Haemonchus and Coccidian fecal egg counts were low in wethers fed diets with 2%, 4%, and 6 % FSF (P < 0.01) compared 11 with wethers fed with 0% FSF inclusion level during the same period. The body condition score of wethers fed on diets with 2%, 4%, and 6% FSF inclusion levels were higher than those on 0% (P < 0.05). Wool yield, staple length, the coefficient variation of the fibre diameter, and fibre of wethers fed on diets with FSF were higher than those without FSF (P < 0.05). The fibre diameter of the wethers fed on FSF supplemented diets was the same as those on 0 % FSF (P > 0.05). The wethers spent more time on FSF supplemented diets and consumed more feed compared to that without FSF supplemented (P < 0.05). The levels of FSF inclusion in the diet affected the enteric methane output (ppm-m), where 4 % FSF had the highest enteric methane output while wethers on 2 % FSF had the lowest methane output (P < 0.05). Resting wethers produced more methane (g/day) than those feeding or standing (P < 0.05). Increasing levels of FSF did not affect ruminal temperature and pH. Ammonia-N increased with increasing FSF except in wethers fed on a diet with 4% FSF (P < 0.01). The total molar concentrations of the wethers' volatile fatty acids decreased with increasing FSF levels (P > 0.05). The acetic propionic ratio of the wethers also decreased except at a 4% inclusion level. The in vitro true digestibility dry matter (IVTDDM), in vitro true digestibility neutral detergent fibre (IVTDNDF), and in vitro true digestibility acid detergent fibre (IVTDADF) of the wethers decreased up to 4% FSF inclusion but tended to increase at 6% inclusion. This study's result as one of the pioneer studies in Dohne-Marino wethers showed that FSF treatment has the potential to improve the nutritional status of the animal and the animal performance and wool quality. Health-wise, FSF decrease nematode population and boost animal immunity as seen in RBC and WBC counts. It also can play a major role in protecting the environment, as seen in its reduction in feacal and urinary nitrogen, which is heavily involved in environmental pollution. Result also confirmed that the best period to target for methane mitigation in ruminants is the resting period. In conclusion, the inclusion of FSF in the diet of Dohne-Merino wethers has the potential to improve the overall performance, with a 4% FSF inclusion level having optimal productivity. However, future research is required to investigate FSF's effect on meat quality, rumen microbial community, in-vivo digestibility, and milk production.
- Full Text:
- Date Issued: 2020
- Authors: Ikusika, Olusegun Oyebade
- Date: 2020
- Subjects: Merino sheep Sheep -- Quality
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/18465 , vital:42542
- Description: The study's broad objective was to assess growth performance, blood and parasitic profiles, wool parameters, methane emission, and nutritional status of Dohne-Merino wethers fed diets supplemented with varying levels of fossil shell flour. Twenty-four Dohne-Merino wethers, averagely weighing 20.0±1.50 kg, were divided into four groups and used in this study. The effects of varying inclusion levels of fossil shell flour (FSF) (0, 2, 4, and 6 %) on feed intake, water intake, nutrient digestibility, N-retention, hematobiochemical and parasitic profiles, body condition scores, feed preference, wool parameters and methane output were determined. The influence of FSF's varying inclusion levels on fermentation parameters, in vitro true digestibility, and relative feed values were also determined. Wethers fed with 4% FSF inclusion level diet showed the highest (P<0.05) values for dry matter intake, average daily weight gain, N retention, (Nitrogen retention) and apparent digestibility of crude protein (CP), Ether Extract (EE) and Ash 6 % (P < 0.05). The urinary N and fecal N were lowest in wethers fed 4% FSF inclusion level and highest in those fed on diets without FSF (P < 0.05). Water intake was highest in wethers fed 0% FSF diet, followed by those fed on 4% and lowest in 6% FSF (P< 0.05). There was a significant increase in white blood cell counts in wethers fed on a diet with 4% and 6% FSF inclusion levels from day 10 to 100 compared to wethers fed on a diet with 0% and 2% FSF (P <0.05). Red blood cell counts also increased significantly in wethers fed on a diet containing 4% FSF, but a slight increase in wethers with 6 % FSF diet, throughout the experimental period (P < 0.05). Blood urea was highest in wethers fed 0% FSF inclusion level and lowest in 6% at day 30 to day 100. Wethers on 4% FSF diet showed an increase in blood urea from day 30 to day 100 (P < 0.05) while wethers on 0% and 2% remained unchanged (P<0.05) during this period and not different (P > 0.05) from wethers on 4% FSF as well. The total protein concentration, albumin, total bilirubin, Na, K, glucose, cholesterol, and liver enzymes were normal for wethers. However, serum creatinine level was lower in wethers fed on 4% FSF than those on 0% FSF (P < 0.01). Haemonchus and Coccidian fecal egg counts were low in wethers fed diets with 2%, 4%, and 6 % FSF (P < 0.01) compared 11 with wethers fed with 0% FSF inclusion level during the same period. The body condition score of wethers fed on diets with 2%, 4%, and 6% FSF inclusion levels were higher than those on 0% (P < 0.05). Wool yield, staple length, the coefficient variation of the fibre diameter, and fibre of wethers fed on diets with FSF were higher than those without FSF (P < 0.05). The fibre diameter of the wethers fed on FSF supplemented diets was the same as those on 0 % FSF (P > 0.05). The wethers spent more time on FSF supplemented diets and consumed more feed compared to that without FSF supplemented (P < 0.05). The levels of FSF inclusion in the diet affected the enteric methane output (ppm-m), where 4 % FSF had the highest enteric methane output while wethers on 2 % FSF had the lowest methane output (P < 0.05). Resting wethers produced more methane (g/day) than those feeding or standing (P < 0.05). Increasing levels of FSF did not affect ruminal temperature and pH. Ammonia-N increased with increasing FSF except in wethers fed on a diet with 4% FSF (P < 0.01). The total molar concentrations of the wethers' volatile fatty acids decreased with increasing FSF levels (P > 0.05). The acetic propionic ratio of the wethers also decreased except at a 4% inclusion level. The in vitro true digestibility dry matter (IVTDDM), in vitro true digestibility neutral detergent fibre (IVTDNDF), and in vitro true digestibility acid detergent fibre (IVTDADF) of the wethers decreased up to 4% FSF inclusion but tended to increase at 6% inclusion. This study's result as one of the pioneer studies in Dohne-Marino wethers showed that FSF treatment has the potential to improve the nutritional status of the animal and the animal performance and wool quality. Health-wise, FSF decrease nematode population and boost animal immunity as seen in RBC and WBC counts. It also can play a major role in protecting the environment, as seen in its reduction in feacal and urinary nitrogen, which is heavily involved in environmental pollution. Result also confirmed that the best period to target for methane mitigation in ruminants is the resting period. In conclusion, the inclusion of FSF in the diet of Dohne-Merino wethers has the potential to improve the overall performance, with a 4% FSF inclusion level having optimal productivity. However, future research is required to investigate FSF's effect on meat quality, rumen microbial community, in-vivo digestibility, and milk production.
- Full Text:
- Date Issued: 2020
Exploring and modelling the effects of agricultural land management and climate change on agroecosystem services in the Eastern Cape, South Africa
- Authors: Choruma, Dennis Junior
- Date: 2020
- Subjects: Agricultural ecology -- South Africa -- Eastern Cape , Agriculture -- Environmental aspects -- South Africa -- Eastern Cape , Crops and climate -- South Africa -- Eastern Cape , Corn -- Climatic factors -- South Africa -- Eastern Cape , Land use -- South Africa -- Eastern Cape
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/146756 , vital:38554
- Description: The aims of this study were to evaluate the impacts of agricultural land management strategies and climate change on irrigated maize production in the Eastern Cape, South Africa. To achieve these aims, the study was guided by two overarching research questions, subsequently broken down into more specific questions. The first research question examined the reasons behind farmers’ current agricultural land management practices, the values they assigned to different agroecosystem services, their perceptions of climate change and the adaptation strategies they used to address challenges associated with agricultural crop production and climate change. To answer these questions, a survey of conventional farmers in the Eastern Cape was carried out. The survey targeted farmers who used fertilisers and irrigation water in their day to day farming. Results showed that farmers recognised the different benefits that agroecosystems provided even though they were not familiar with the term ‘ecosystem services.’ Farmers assigned a high value to food provisioning compared to other agroecosystem services and managed their farms for maximum crop yields or maximum crop quality. Fertiliser and irrigation water management decisions were based on multiple factors such as cost, availability of farming equipment and crop yield or crop quality considerations. Survey results showed that while most farmers were able to state the amount of fertiliser used per growing season, the majority of farmers did not know the amount of water they used per growing season. From the farmers’ survey it was recommended that extension services and agricultural education programmes be strengthened in the region to increase farmers’ knowledge on effective agricultural land management strategies that support sustainable intensification. The second research question investigated the effects of agricultural land management strategies and climate change on crop yields in the Eastern Cape. This investigation was done in three steps. First, a crop model, the Environmental Policy Integrated Climate (EPIC) model was calibrated and validated using limited field data from maize variety trials carried out at the Cradock Research Farm in the Eastern Cape. Calibration and validation results proved satisfactory with model efficiencies (Nash Sutcliffe, NSE) greater than 0.5 for both calibration and validation. It was concluded that limited data from field trials on maize that only included grain yield and agricultural land management dates can be used for the calibration of the EPIC model to simulate maize production under South African conditions. In the second step, the calibrated model was applied to simulate different irrigation and fertiliser management strategies for maize production in the Eastern Cape. Different irrigation and Nitrogen (N) fertiliser levels were compared to find optimal irrigation and N fertiliser management strategies that would increase maize yields while minimising environmental pollution (nitrate leaching). Model outputs were also compared to the average yields obtained in the field trials (baseline) and to maize yields reported by farmers in the farmers’ survey. Results showed that improved management of irrigation water and N fertiliser could improve farmers’ maize yields from approximately 7.2 t ha-1 to approximately 12.2 t ha-1, an increase of approximately 69%. Results also revealed a trade-off between food provision and nitrate leaching. Simulations showed that increasing N fertiliser application under sufficient irrigation water levels would increase maize yields, however, this would be accompanied by an increase in N leaching. Lastly, the EPIC model was then applied to simulate the effects of future climate change on irrigated maize production in the Eastern Cape. For these simulations, the model was driven by statistically downscaled climate data derived from three General Circulation Models (GCMs) for two future climate periods, (2040-2069) and (2070-2099), under two Representative Concentration Pathways (RCPs): RCP 4.5 and RCP 8.5. Future maize yields were compared to the baseline (1980-2010) maize yield average. All three climate models predicted a decline in maize yields, with yields declining by as much as 23.8% in RCP 8.5, 2070-2099. Simulations also predicted increases in average daily maximum and minimum temperatures for both the two future climate periods under both RCPs. Results also indicated a decrease in seasonal irrigation water requirements. Nitrate leaching was projected to significantly increase towards the end of the century, increasing by as much as 373.8% in RCP 8.5 2070-2099. Concerning farmers’ perceptions of climate change, results showed that farmers were aware of climate change and identified temperature and rainfall changes as the most important changes in climate that they had observed. To adapt to climate change, farmers used a variety of adaptation strategies such as crop rotations and intercropping. Apart from challenges posed by climate change, farmers also faced other challenges such as access to markets and access to financial credit lines, challenges that prevented them from effectively adapting to climate change. The study therefore recommended that appropriate and adequate strategies be designed to help farmers in the region offset the projected decrease in maize production and increase crop yields while minimising negative environmental impacts.
- Full Text:
- Date Issued: 2020
- Authors: Choruma, Dennis Junior
- Date: 2020
- Subjects: Agricultural ecology -- South Africa -- Eastern Cape , Agriculture -- Environmental aspects -- South Africa -- Eastern Cape , Crops and climate -- South Africa -- Eastern Cape , Corn -- Climatic factors -- South Africa -- Eastern Cape , Land use -- South Africa -- Eastern Cape
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/146756 , vital:38554
- Description: The aims of this study were to evaluate the impacts of agricultural land management strategies and climate change on irrigated maize production in the Eastern Cape, South Africa. To achieve these aims, the study was guided by two overarching research questions, subsequently broken down into more specific questions. The first research question examined the reasons behind farmers’ current agricultural land management practices, the values they assigned to different agroecosystem services, their perceptions of climate change and the adaptation strategies they used to address challenges associated with agricultural crop production and climate change. To answer these questions, a survey of conventional farmers in the Eastern Cape was carried out. The survey targeted farmers who used fertilisers and irrigation water in their day to day farming. Results showed that farmers recognised the different benefits that agroecosystems provided even though they were not familiar with the term ‘ecosystem services.’ Farmers assigned a high value to food provisioning compared to other agroecosystem services and managed their farms for maximum crop yields or maximum crop quality. Fertiliser and irrigation water management decisions were based on multiple factors such as cost, availability of farming equipment and crop yield or crop quality considerations. Survey results showed that while most farmers were able to state the amount of fertiliser used per growing season, the majority of farmers did not know the amount of water they used per growing season. From the farmers’ survey it was recommended that extension services and agricultural education programmes be strengthened in the region to increase farmers’ knowledge on effective agricultural land management strategies that support sustainable intensification. The second research question investigated the effects of agricultural land management strategies and climate change on crop yields in the Eastern Cape. This investigation was done in three steps. First, a crop model, the Environmental Policy Integrated Climate (EPIC) model was calibrated and validated using limited field data from maize variety trials carried out at the Cradock Research Farm in the Eastern Cape. Calibration and validation results proved satisfactory with model efficiencies (Nash Sutcliffe, NSE) greater than 0.5 for both calibration and validation. It was concluded that limited data from field trials on maize that only included grain yield and agricultural land management dates can be used for the calibration of the EPIC model to simulate maize production under South African conditions. In the second step, the calibrated model was applied to simulate different irrigation and fertiliser management strategies for maize production in the Eastern Cape. Different irrigation and Nitrogen (N) fertiliser levels were compared to find optimal irrigation and N fertiliser management strategies that would increase maize yields while minimising environmental pollution (nitrate leaching). Model outputs were also compared to the average yields obtained in the field trials (baseline) and to maize yields reported by farmers in the farmers’ survey. Results showed that improved management of irrigation water and N fertiliser could improve farmers’ maize yields from approximately 7.2 t ha-1 to approximately 12.2 t ha-1, an increase of approximately 69%. Results also revealed a trade-off between food provision and nitrate leaching. Simulations showed that increasing N fertiliser application under sufficient irrigation water levels would increase maize yields, however, this would be accompanied by an increase in N leaching. Lastly, the EPIC model was then applied to simulate the effects of future climate change on irrigated maize production in the Eastern Cape. For these simulations, the model was driven by statistically downscaled climate data derived from three General Circulation Models (GCMs) for two future climate periods, (2040-2069) and (2070-2099), under two Representative Concentration Pathways (RCPs): RCP 4.5 and RCP 8.5. Future maize yields were compared to the baseline (1980-2010) maize yield average. All three climate models predicted a decline in maize yields, with yields declining by as much as 23.8% in RCP 8.5, 2070-2099. Simulations also predicted increases in average daily maximum and minimum temperatures for both the two future climate periods under both RCPs. Results also indicated a decrease in seasonal irrigation water requirements. Nitrate leaching was projected to significantly increase towards the end of the century, increasing by as much as 373.8% in RCP 8.5 2070-2099. Concerning farmers’ perceptions of climate change, results showed that farmers were aware of climate change and identified temperature and rainfall changes as the most important changes in climate that they had observed. To adapt to climate change, farmers used a variety of adaptation strategies such as crop rotations and intercropping. Apart from challenges posed by climate change, farmers also faced other challenges such as access to markets and access to financial credit lines, challenges that prevented them from effectively adapting to climate change. The study therefore recommended that appropriate and adequate strategies be designed to help farmers in the region offset the projected decrease in maize production and increase crop yields while minimising negative environmental impacts.
- Full Text:
- Date Issued: 2020
Exploring teaching and learning German as a foreign language at a South African institution of higher education: blended learning and collocations
- Authors: Ortner, Gwyndolen Jeanie
- Date: 2020
- Subjects: German language -- Study and teaching (Higher) -- South Africa , German language -- Study and teaching (Higher) -- Foreign speakers -- South Africa , German language -- Study and teaching (Higher) -- English speakers -- South Africa , Rhodes University -- Students , Rhodes University. German Studies
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/167295 , vital:41465
- Description: German Studies students at Rhodes University have normally never studied the German language before enrolling for the first-year course and face the challenge of a fairly rapid linguistic advancement, in a context with very limited exposure to the foreign language outside the classroom. Free writing is an area which students find particularly challenging as it requires students to syndissertatione grammatical and vocabulary knowledge. Furthermore, South African students are often underprepared for the challenges they face at university regarding language, technology and finance, as they try to to assimilate to the academic environment and gain epistemological access to their various subjects, in this case, language acquisition and the attendant modules of translation, literature and cultural studies. The use of technology in teaching and learning, known as blended learning, is said to produce better results than face-to face teaching alone, through creating opportunities for more autonomous student learning. Scholars of instructed second-language acquisition also suggest using technology to improve language instruction. One particular area which is gaining ground is teaching students collocational structures through exploring large language corpora, to improve students’ language competencies such as writing fluency. However, both blended learning practices and corpus-based teaching practices suggested by scholars are often not reported on in a particular teaching and learning context, taking into account factors such as institutional infrastructure, student and staff backgrounds and preparedness, and larger socio-political factors. Thus, it remains unclear how these practices (blended learning and corpus-based teaching of collocations) may be integrated into standard urricula, particularly for languages other than English, which have been severely under-researched. The purpose of this research is to take a context-based approach to language teaching and thereby investigate current blended learning practices for German Studies at Rhodes University in South Africa and explore through an action research approach how to integrate collocational awareness into the curriculum, within the blended learning model. Insights from corpus linguistics guide an adaptation of teaching practice, helping students develop skills to aid with writing fluency, seeking to make the patterned nature of language salient to our students. This is undertaken in a scaffolded way, within the curriculum, making use firstly of the texts to which students are exposed in the textbook (comprehensible input) as a source of collocational examples, and following this by making use of reallife language data from an online German corpus, DWDS. Findings from the study reveal a number of best practices related to the use of blended learning and teaching collocations in context of the German foreign language curriculum at a South African institution of higher education.
- Full Text:
- Date Issued: 2020
- Authors: Ortner, Gwyndolen Jeanie
- Date: 2020
- Subjects: German language -- Study and teaching (Higher) -- South Africa , German language -- Study and teaching (Higher) -- Foreign speakers -- South Africa , German language -- Study and teaching (Higher) -- English speakers -- South Africa , Rhodes University -- Students , Rhodes University. German Studies
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/167295 , vital:41465
- Description: German Studies students at Rhodes University have normally never studied the German language before enrolling for the first-year course and face the challenge of a fairly rapid linguistic advancement, in a context with very limited exposure to the foreign language outside the classroom. Free writing is an area which students find particularly challenging as it requires students to syndissertatione grammatical and vocabulary knowledge. Furthermore, South African students are often underprepared for the challenges they face at university regarding language, technology and finance, as they try to to assimilate to the academic environment and gain epistemological access to their various subjects, in this case, language acquisition and the attendant modules of translation, literature and cultural studies. The use of technology in teaching and learning, known as blended learning, is said to produce better results than face-to face teaching alone, through creating opportunities for more autonomous student learning. Scholars of instructed second-language acquisition also suggest using technology to improve language instruction. One particular area which is gaining ground is teaching students collocational structures through exploring large language corpora, to improve students’ language competencies such as writing fluency. However, both blended learning practices and corpus-based teaching practices suggested by scholars are often not reported on in a particular teaching and learning context, taking into account factors such as institutional infrastructure, student and staff backgrounds and preparedness, and larger socio-political factors. Thus, it remains unclear how these practices (blended learning and corpus-based teaching of collocations) may be integrated into standard urricula, particularly for languages other than English, which have been severely under-researched. The purpose of this research is to take a context-based approach to language teaching and thereby investigate current blended learning practices for German Studies at Rhodes University in South Africa and explore through an action research approach how to integrate collocational awareness into the curriculum, within the blended learning model. Insights from corpus linguistics guide an adaptation of teaching practice, helping students develop skills to aid with writing fluency, seeking to make the patterned nature of language salient to our students. This is undertaken in a scaffolded way, within the curriculum, making use firstly of the texts to which students are exposed in the textbook (comprehensible input) as a source of collocational examples, and following this by making use of reallife language data from an online German corpus, DWDS. Findings from the study reveal a number of best practices related to the use of blended learning and teaching collocations in context of the German foreign language curriculum at a South African institution of higher education.
- Full Text:
- Date Issued: 2020
Financial integration in the BRICS countries
- Authors: Nach, Marida Nephertiti
- Date: 2020
- Subjects: Autogression (Statistics) -- mathematical models , Monetary policy -- Econometric models
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/50609 , vital:42278
- Description: An optimum currency area (OCA) owes its definition to Robert Mundell (1961). In his seminal paper, Mundell (1961) defines an OCA as an area for which the costs of relinquishing the exchange rate as an internal instrument of adjustments are outweighed by the benefits of adopting a single currency or a fixed exchange rate regime. Mundell (1961) emphasises two major benefits of adopting a single currency: the elimination of transaction costs and a better performance of money as a medium of exchange and as a unit of account. Thus far, OCA theory has served as the framework for the discussion about monetary integration and has provided an explanation for the monetary integration processes around the world both developed and developing countries in Europe, Asia, Africa, and Latin America. The emergence of the BRICS (Brazil, Russia, India, China, South Africa) countries can be a model and a representation of developing and emerging countries in the global economic and financial system. Hence, this has made the BRICS economies the object of many discussions and recent empirical researches. The research presented in this thesis uses a structural vector autoregression (SVAR) econometric model to explore whether there is a feasibility of macroeconomic convergence among the BRICS economies. The SVAR model permitted to examine the symmetry of shocks (supply, demand and monetary) among the five BRICS countries. The findings of this research showed that there was some degree of symmetry of shocks among the BRICS countries. Nevertheless, there is a need for more policy coordination in order to achieve the desired level of symmetry of shocks among these countries.
- Full Text:
- Date Issued: 2020
- Authors: Nach, Marida Nephertiti
- Date: 2020
- Subjects: Autogression (Statistics) -- mathematical models , Monetary policy -- Econometric models
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/50609 , vital:42278
- Description: An optimum currency area (OCA) owes its definition to Robert Mundell (1961). In his seminal paper, Mundell (1961) defines an OCA as an area for which the costs of relinquishing the exchange rate as an internal instrument of adjustments are outweighed by the benefits of adopting a single currency or a fixed exchange rate regime. Mundell (1961) emphasises two major benefits of adopting a single currency: the elimination of transaction costs and a better performance of money as a medium of exchange and as a unit of account. Thus far, OCA theory has served as the framework for the discussion about monetary integration and has provided an explanation for the monetary integration processes around the world both developed and developing countries in Europe, Asia, Africa, and Latin America. The emergence of the BRICS (Brazil, Russia, India, China, South Africa) countries can be a model and a representation of developing and emerging countries in the global economic and financial system. Hence, this has made the BRICS economies the object of many discussions and recent empirical researches. The research presented in this thesis uses a structural vector autoregression (SVAR) econometric model to explore whether there is a feasibility of macroeconomic convergence among the BRICS economies. The SVAR model permitted to examine the symmetry of shocks (supply, demand and monetary) among the five BRICS countries. The findings of this research showed that there was some degree of symmetry of shocks among the BRICS countries. Nevertheless, there is a need for more policy coordination in order to achieve the desired level of symmetry of shocks among these countries.
- Full Text:
- Date Issued: 2020
Financial services use in a rural context: a case of rural communities in South Africa
- Authors: Maciko,Loyiso
- Date: 2020
- Subjects: Finance --South Africa Financial institutions -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD (Economics)
- Identifier: http://hdl.handle.net/10353/18930 , vital:42999
- Description: The thesis focuses on the gap between access and usage of financial services in rural communities of South Africa by using primary data and secondary data. It seeks to examine the factors that affect financial inclusion in rural communities of South Africa and to investigate South African trends regarding utilisation of financial services. This is since there has been an increase on adoption of financial services in South Africa however, this has not been complemented by effective usage. This rise in access of banks paints a misleading picture that majority of South Africans are included while the usage strand remains unmet as most people use bank accounts as a ‘mailbox’. This creates interest on what might be the underlying causes for lack of use, particularly in rural areas. This study adopts a mixed-methods approach in the form of exploratory sequential approach. This study was done in two stages. Firstly, focus groups were conducted in 20 villages from the Eastern Cape and Kwa-Zulu Natal. During the second stage, the quantitative research was conducted, using Finscope data for all provinces covering 2013 to 2017. For data analysis the Binary logistic regression and Multinomial regressions were adopted The study discovered that rural households from the Eastern Cape and Kwa-Zulu Natal, Limpopo and other provinces, dominated by rural areas, are often detached from the formal economy. As is the case with the rural residents that partook in this study relative to Gauteng, they did not derive any benefit from most formal economic initiatives or policies aimed at improving their well-being through access and use of financial services. Secondly, lack of income, trust, costs of financial services and distance to the nearest financial service provider remain barriers to use of financial services. To have a qualification or degree is regarded as an important factor that influences whether one saves at a bank. This causes rural residents with less education to rely on more informal saving methods. Furthermore, this study showed that households in rural locations of South Africa were either not aware or confident enough about the use and benefits of insurance and other financial services. Therefore, awareness campaigns should be promoted to gain client confidence by educating the current and potential clients. Rural households should be made aware of the safety that financial institutions give them, the interest rates earned, and the benefits that come with investing in formal institutions contrary to not investing. This study suggests that access and use of financial services has a non-uniform impact on household wealth. Thus, for effective poverty eradication in rural communities, there is a need for customized financial services and products aimed at addressing the explicit needs of the marginalised, as their needs diverge along the poverty distribution line. The results provide support to Andersen’s model as a mechanism that can be used to explain the demand-side perspective within the South African rural context. The study has made an empirical contribution tailored to the South African context. This study contributes to the current body of literature by applying the modified version of the Andersen Behavioural Model to financial vi services. It further contributes to the understanding of the relationship between the barrier to use or not use financial services in South African rural areas. It proposes that for financial market participation in the old traditional banking way there is a need to bring services to the people, and design the financial products in the manner that addresses the specific needs of the people in rural communities.
- Full Text:
- Date Issued: 2020
- Authors: Maciko,Loyiso
- Date: 2020
- Subjects: Finance --South Africa Financial institutions -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD (Economics)
- Identifier: http://hdl.handle.net/10353/18930 , vital:42999
- Description: The thesis focuses on the gap between access and usage of financial services in rural communities of South Africa by using primary data and secondary data. It seeks to examine the factors that affect financial inclusion in rural communities of South Africa and to investigate South African trends regarding utilisation of financial services. This is since there has been an increase on adoption of financial services in South Africa however, this has not been complemented by effective usage. This rise in access of banks paints a misleading picture that majority of South Africans are included while the usage strand remains unmet as most people use bank accounts as a ‘mailbox’. This creates interest on what might be the underlying causes for lack of use, particularly in rural areas. This study adopts a mixed-methods approach in the form of exploratory sequential approach. This study was done in two stages. Firstly, focus groups were conducted in 20 villages from the Eastern Cape and Kwa-Zulu Natal. During the second stage, the quantitative research was conducted, using Finscope data for all provinces covering 2013 to 2017. For data analysis the Binary logistic regression and Multinomial regressions were adopted The study discovered that rural households from the Eastern Cape and Kwa-Zulu Natal, Limpopo and other provinces, dominated by rural areas, are often detached from the formal economy. As is the case with the rural residents that partook in this study relative to Gauteng, they did not derive any benefit from most formal economic initiatives or policies aimed at improving their well-being through access and use of financial services. Secondly, lack of income, trust, costs of financial services and distance to the nearest financial service provider remain barriers to use of financial services. To have a qualification or degree is regarded as an important factor that influences whether one saves at a bank. This causes rural residents with less education to rely on more informal saving methods. Furthermore, this study showed that households in rural locations of South Africa were either not aware or confident enough about the use and benefits of insurance and other financial services. Therefore, awareness campaigns should be promoted to gain client confidence by educating the current and potential clients. Rural households should be made aware of the safety that financial institutions give them, the interest rates earned, and the benefits that come with investing in formal institutions contrary to not investing. This study suggests that access and use of financial services has a non-uniform impact on household wealth. Thus, for effective poverty eradication in rural communities, there is a need for customized financial services and products aimed at addressing the explicit needs of the marginalised, as their needs diverge along the poverty distribution line. The results provide support to Andersen’s model as a mechanism that can be used to explain the demand-side perspective within the South African rural context. The study has made an empirical contribution tailored to the South African context. This study contributes to the current body of literature by applying the modified version of the Andersen Behavioural Model to financial vi services. It further contributes to the understanding of the relationship between the barrier to use or not use financial services in South African rural areas. It proposes that for financial market participation in the old traditional banking way there is a need to bring services to the people, and design the financial products in the manner that addresses the specific needs of the people in rural communities.
- Full Text:
- Date Issued: 2020
Foraging for fruits: natural resource use and its conservation potential in urban environments
- Authors: Sardeshpande, Mallika
- Date: 2020
- Subjects: Non-timber forest products , Wild plants, Edible , Urban plants , Urban ecology (Biology) , Open spaces , Environmental protection -- Citizen participation
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/167465 , vital:41483
- Description: Wild edible fruits (WEFs) are a type of natural resource that humans across the world collect from diverse natural landscapes. They are among the most used non-timber forest products (NTFPs) and wild foods, and often serve more than a nutritional purpose for humans, in the form of fibre, fuel, medicine, and other products. The use of WEFs may augment household dietary diversity, food security, and income in some contexts. The prevalence of WEF species across the spectrum of natural to modified ecosystems presents the potential for integrated landscape-level conservation efforts centred on these species. The first half of this thesis investigates the state of knowledge about this versatile and ubiquitous resource in the wider context of other wild foods and NTFPs, and compares the patterns of use of WEFs with those of other wild foods and NTFPs. Through these studies, I find that WEFs are indeed a widely occurring, resilient, and useful resource along the rural-urban gradient. They are unique in that their use transcends the geographical and socio-economic criteria that influence the use of other wild foods and NTFPs. Based on these findings, in the second half of the thesis, I propose the use-based conservation of WEF species in urban landscapes through the practice of urban foraging. Through interviews with urban land managers and foragers, I describe the state of urban green space management and urban foraging, and identify synergies between the two. Green space management is increasingly devolved and well-defined in developed cities, and relatively diffused in smaller towns, but nevertheless supportive of use-based biodiversity conservation. Planting and foraging for WEFs in urban green spaces ties in with local and national objectives of urban land use management policy. However, the lack of information on species, spaces, and sustainability related to foraging are a hindrance to addressing this activity and harnessing its conservation potential. Foragers use a variety of WEF species collected from natural as well as highly used and urbanised areas in their cities. Although most foragers consider foraging as a cultural and recreational activity, many of them agreed with the prospect of commercialising or popularising it to protect and promote the biodiversity and culture associated with their foraging spaces. The synthesis of this study presents four possible pathways to conserve the diversity of WEF species, and to extend the benefits of WEF use to landscape stewardship. It identifies key stakeholders in implementing these pathways and possible collaborations between these stakeholders; the multiple conservation objectives and policies these pathways respond to; and context-specific considerations for policy and implementation related to planting and foraging of WEFs.
- Full Text:
- Date Issued: 2020
- Authors: Sardeshpande, Mallika
- Date: 2020
- Subjects: Non-timber forest products , Wild plants, Edible , Urban plants , Urban ecology (Biology) , Open spaces , Environmental protection -- Citizen participation
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/167465 , vital:41483
- Description: Wild edible fruits (WEFs) are a type of natural resource that humans across the world collect from diverse natural landscapes. They are among the most used non-timber forest products (NTFPs) and wild foods, and often serve more than a nutritional purpose for humans, in the form of fibre, fuel, medicine, and other products. The use of WEFs may augment household dietary diversity, food security, and income in some contexts. The prevalence of WEF species across the spectrum of natural to modified ecosystems presents the potential for integrated landscape-level conservation efforts centred on these species. The first half of this thesis investigates the state of knowledge about this versatile and ubiquitous resource in the wider context of other wild foods and NTFPs, and compares the patterns of use of WEFs with those of other wild foods and NTFPs. Through these studies, I find that WEFs are indeed a widely occurring, resilient, and useful resource along the rural-urban gradient. They are unique in that their use transcends the geographical and socio-economic criteria that influence the use of other wild foods and NTFPs. Based on these findings, in the second half of the thesis, I propose the use-based conservation of WEF species in urban landscapes through the practice of urban foraging. Through interviews with urban land managers and foragers, I describe the state of urban green space management and urban foraging, and identify synergies between the two. Green space management is increasingly devolved and well-defined in developed cities, and relatively diffused in smaller towns, but nevertheless supportive of use-based biodiversity conservation. Planting and foraging for WEFs in urban green spaces ties in with local and national objectives of urban land use management policy. However, the lack of information on species, spaces, and sustainability related to foraging are a hindrance to addressing this activity and harnessing its conservation potential. Foragers use a variety of WEF species collected from natural as well as highly used and urbanised areas in their cities. Although most foragers consider foraging as a cultural and recreational activity, many of them agreed with the prospect of commercialising or popularising it to protect and promote the biodiversity and culture associated with their foraging spaces. The synthesis of this study presents four possible pathways to conserve the diversity of WEF species, and to extend the benefits of WEF use to landscape stewardship. It identifies key stakeholders in implementing these pathways and possible collaborations between these stakeholders; the multiple conservation objectives and policies these pathways respond to; and context-specific considerations for policy and implementation related to planting and foraging of WEFs.
- Full Text:
- Date Issued: 2020
Foraging in a dynamic environment: movement and stable isotope ecology of marine top predators breeding at the Prince Edward Archipelago
- Authors: Carpenter-Kling, Tegan
- Date: 2020
- Subjects: Marine ecology , Stable isotope tracers , Estuarine ecology
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/49049 , vital:41596
- Description: Marine ecosystems are experiencing rapid changes due to climate change. The associated temporal and spatial changes in resource distribution impacts on the foraging behaviour of marine top predators. If these changes negatively affect the ability of marine predators to forage efficiently, there may be dire consequences for their populations. However, evidence of foraging plasticity during adverse conditions, or generalist foraging behaviour, can allow inference about the resilience of species to environmental change and provide essential knowledge towards effective and proactive conservation measures. I examined plasticity in the trophic ecology of 12 marine predator species breeding on Marion Island, southern Indian Ocean, over three years (2015 – 2018), a period characterized by pronounced environmental variability. Firstly, I correlated behavioural states inferred along the GPS tracks of incubating wandering, grey-headed, sooty and light-mantled albatrosses to environmental variables that are indicative of biologically productive oceanographic features. Secondly, I analysed δ13C and δ15N blood values in 12 marine predator species (the afore-mentioned albatrosses as well as king, gentoo, macaroni and eastern rockhopper penguins, northern and southern giant petrels and Antarctic and sub-Antarctic fur seals) over two seasons: summer and autumn. My results revealed that the foraging behaviour of all the species is, to some degree, either plastic (temporally variable isotopic niche) or general (large isotopic niche which remained similar over time), except for the king penguin (small isotopic niche which remained similar over time), a known foraging specialist. Furthermore, despite their dynamic foraging behaviour, resource partitioning among the predators was maintained over time. Due to the ease and relatively low cost of collecting tissues for stable isotope analysis it has the potential to be a powerful tool to monitor the trophic ecology of marine predators. I thus used my simultaneously collected dataset of GPS tracks with the stable isotope blood compositions to investigate some of the assumptions underlying the inferences made from marine predator δ13C and δ15N blood values. I reconstructed species- and guild- specific δ13C and δ15N isoscapes for eight seabird species. Following this, I coupled individual-based movement models of northern giant petrels with global marine isotope models to explore the sensitivity of tissue δ13C values to a range of extrinsic (environmental) and intrinsic (behavioural, physiological) drivers. My results demonstrate the strong influence of reference isoscapes on the inference of stable isotope compositions of marine predators. Furthermore, I show that caution should be used when using non-species-specific or temporally inaccurate isoscapes. I furthermore demonstrate that biological interactions, such as competition for food resources, either past or present, as well as spatio-temporal distribution of food patches strongly influence the foraging behaviour of marine predators. These findings highlight the importance of integrating biological interactions in species distribution models which are used to predict possible distributional shifts of marine predators in the context of global changes. My thesis further developed previously available methods and presents a novel approach to investigate sources of variance in the stable isotopic composition of animals’ tissues.
- Full Text:
- Date Issued: 2020
- Authors: Carpenter-Kling, Tegan
- Date: 2020
- Subjects: Marine ecology , Stable isotope tracers , Estuarine ecology
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/49049 , vital:41596
- Description: Marine ecosystems are experiencing rapid changes due to climate change. The associated temporal and spatial changes in resource distribution impacts on the foraging behaviour of marine top predators. If these changes negatively affect the ability of marine predators to forage efficiently, there may be dire consequences for their populations. However, evidence of foraging plasticity during adverse conditions, or generalist foraging behaviour, can allow inference about the resilience of species to environmental change and provide essential knowledge towards effective and proactive conservation measures. I examined plasticity in the trophic ecology of 12 marine predator species breeding on Marion Island, southern Indian Ocean, over three years (2015 – 2018), a period characterized by pronounced environmental variability. Firstly, I correlated behavioural states inferred along the GPS tracks of incubating wandering, grey-headed, sooty and light-mantled albatrosses to environmental variables that are indicative of biologically productive oceanographic features. Secondly, I analysed δ13C and δ15N blood values in 12 marine predator species (the afore-mentioned albatrosses as well as king, gentoo, macaroni and eastern rockhopper penguins, northern and southern giant petrels and Antarctic and sub-Antarctic fur seals) over two seasons: summer and autumn. My results revealed that the foraging behaviour of all the species is, to some degree, either plastic (temporally variable isotopic niche) or general (large isotopic niche which remained similar over time), except for the king penguin (small isotopic niche which remained similar over time), a known foraging specialist. Furthermore, despite their dynamic foraging behaviour, resource partitioning among the predators was maintained over time. Due to the ease and relatively low cost of collecting tissues for stable isotope analysis it has the potential to be a powerful tool to monitor the trophic ecology of marine predators. I thus used my simultaneously collected dataset of GPS tracks with the stable isotope blood compositions to investigate some of the assumptions underlying the inferences made from marine predator δ13C and δ15N blood values. I reconstructed species- and guild- specific δ13C and δ15N isoscapes for eight seabird species. Following this, I coupled individual-based movement models of northern giant petrels with global marine isotope models to explore the sensitivity of tissue δ13C values to a range of extrinsic (environmental) and intrinsic (behavioural, physiological) drivers. My results demonstrate the strong influence of reference isoscapes on the inference of stable isotope compositions of marine predators. Furthermore, I show that caution should be used when using non-species-specific or temporally inaccurate isoscapes. I furthermore demonstrate that biological interactions, such as competition for food resources, either past or present, as well as spatio-temporal distribution of food patches strongly influence the foraging behaviour of marine predators. These findings highlight the importance of integrating biological interactions in species distribution models which are used to predict possible distributional shifts of marine predators in the context of global changes. My thesis further developed previously available methods and presents a novel approach to investigate sources of variance in the stable isotopic composition of animals’ tissues.
- Full Text:
- Date Issued: 2020
Formulation development, manufacture and evaluation of a lamivudine-zidovudine nano co-crystal thermo-responsive suspension
- Authors: Witika, Bwalya Angel
- Date: 2020
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/140546 , vital:37897 , http://dx.doi.org/10.21504/10962/140546
- Description: Expected release date-April 2021
- Full Text:
- Date Issued: 2020
- Authors: Witika, Bwalya Angel
- Date: 2020
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/140546 , vital:37897 , http://dx.doi.org/10.21504/10962/140546
- Description: Expected release date-April 2021
- Full Text:
- Date Issued: 2020
Fraud tolerance level as a predictor of insurance claims behavior: A South African Study
- Authors: Chetty,Moonsamy Perumal
- Date: 2020
- Subjects: Insurance fraud Fraud -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD(Criminology)
- Identifier: http://hdl.handle.net/10353/17964 , vital:41999
- Description: The insurance sector as a foundation which other sectors depend on is a critical cornerstone of a well-functioning society. An insurer’s strength exists in its ability to foresee, assess, price and mitigate current and emerging risks. Despite the value that insurance brings to maintaining and sustaining society there is large scale abuse of the various insurance products on offer. The abuse is predominately committed through the submitting of either false or inflated claims which negatively impacts the entire insurance value chain from underwriting to claims processes. Insurance claims fraud is classified as opportunistic or organised. Opportunistic claims fraud consists of claims inflation or claims padding for a genuine loss while organised claims fraud involves the lodging a claim for a loss that did not occur and usually involves staging of incidents. Opportunistic fraud is the most common type of fraud experienced by insurers and presents the greatest challenge to the insurance industry. While there are challenges in accurately determining the true costs of insurance fraud; there is consensus that the costs are significant. In response to incidents of insurance fraud insurers have implemented various measures to curb fraud; these measures range from the establishment of insurance crime bureaus, creation of internal investigation teams and the employment of technology as early warning systems. These measures although useful have not been able to be very effective as insurance fraud still continues to rise. Studies indicate that consumer attitudes towards insurance fraud play an important role which must be considered when developing fraud prevention strategies. Tolerance has been identified as an important factor which influence consumer v attitudes towards insurance fraud. Previous studies found that factors such as high insurance premiums, excess payments, consumer relationship with insurers, consumer’s previous claims experience and societal acceptability of insurance fraud played a role in shaping a consumer’s tolerance level. This study was undertaken to explore the role that policyholder tolerance has on predicting claims behaviour in the South African insurance market. The study also aimed at identifying reasons which motivated policyholder’s to commit and deter them from committing insurance fraud. A further aim was to identify the common types of insurance fraud and to measure policyholders’ perceptions towards their primary insurer, the insurance industry, brokers and insurance assessors. The fraud triangle and the theory of planned behaviour were used as theories in support of this study. Primary data for this study was gather through an online self-administered questionnaire and the sample population consisted of policyholders within the shortterm insurance market. A total of 560 completed valid questionnaires were received and analysed. The study shows that respondents have low levels of tolerance for insurance fraud. Results indicated that financial pressure, greed, financial benefit and opportunity were reasons why policyholders’ committed insurance fraud in SA. Factors which deterred policyholders from committing insurance fraud included consumer integrity and honesty, fear of being caught and prosecuted and fairness and value for money. vi Respondents indicated that inflated claims were more prevalent than false claims and it was easier to submit an inflated claim than a false claim. Regarding perceptions the study shows that respondents have a more positive view of their own primary insurer than the insurance industry in general, brokers and insurance assessors. Lastly, the research identified five factors that significantly explain levels of short-term insurance fraud tolerance, namely 'Unfairness/injustice', “Have policyholders’ best interest at heart”, 'Industry relations', ‘Opportunity’ and 'Morality'. The findings of this study could be useful to insurers when developing consumer education and awareness programmes. There exists opportunities for future research regarding several aspects of insurance fraud which was not dealt with in this study.
- Full Text:
- Date Issued: 2020
- Authors: Chetty,Moonsamy Perumal
- Date: 2020
- Subjects: Insurance fraud Fraud -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD(Criminology)
- Identifier: http://hdl.handle.net/10353/17964 , vital:41999
- Description: The insurance sector as a foundation which other sectors depend on is a critical cornerstone of a well-functioning society. An insurer’s strength exists in its ability to foresee, assess, price and mitigate current and emerging risks. Despite the value that insurance brings to maintaining and sustaining society there is large scale abuse of the various insurance products on offer. The abuse is predominately committed through the submitting of either false or inflated claims which negatively impacts the entire insurance value chain from underwriting to claims processes. Insurance claims fraud is classified as opportunistic or organised. Opportunistic claims fraud consists of claims inflation or claims padding for a genuine loss while organised claims fraud involves the lodging a claim for a loss that did not occur and usually involves staging of incidents. Opportunistic fraud is the most common type of fraud experienced by insurers and presents the greatest challenge to the insurance industry. While there are challenges in accurately determining the true costs of insurance fraud; there is consensus that the costs are significant. In response to incidents of insurance fraud insurers have implemented various measures to curb fraud; these measures range from the establishment of insurance crime bureaus, creation of internal investigation teams and the employment of technology as early warning systems. These measures although useful have not been able to be very effective as insurance fraud still continues to rise. Studies indicate that consumer attitudes towards insurance fraud play an important role which must be considered when developing fraud prevention strategies. Tolerance has been identified as an important factor which influence consumer v attitudes towards insurance fraud. Previous studies found that factors such as high insurance premiums, excess payments, consumer relationship with insurers, consumer’s previous claims experience and societal acceptability of insurance fraud played a role in shaping a consumer’s tolerance level. This study was undertaken to explore the role that policyholder tolerance has on predicting claims behaviour in the South African insurance market. The study also aimed at identifying reasons which motivated policyholder’s to commit and deter them from committing insurance fraud. A further aim was to identify the common types of insurance fraud and to measure policyholders’ perceptions towards their primary insurer, the insurance industry, brokers and insurance assessors. The fraud triangle and the theory of planned behaviour were used as theories in support of this study. Primary data for this study was gather through an online self-administered questionnaire and the sample population consisted of policyholders within the shortterm insurance market. A total of 560 completed valid questionnaires were received and analysed. The study shows that respondents have low levels of tolerance for insurance fraud. Results indicated that financial pressure, greed, financial benefit and opportunity were reasons why policyholders’ committed insurance fraud in SA. Factors which deterred policyholders from committing insurance fraud included consumer integrity and honesty, fear of being caught and prosecuted and fairness and value for money. vi Respondents indicated that inflated claims were more prevalent than false claims and it was easier to submit an inflated claim than a false claim. Regarding perceptions the study shows that respondents have a more positive view of their own primary insurer than the insurance industry in general, brokers and insurance assessors. Lastly, the research identified five factors that significantly explain levels of short-term insurance fraud tolerance, namely 'Unfairness/injustice', “Have policyholders’ best interest at heart”, 'Industry relations', ‘Opportunity’ and 'Morality'. The findings of this study could be useful to insurers when developing consumer education and awareness programmes. There exists opportunities for future research regarding several aspects of insurance fraud which was not dealt with in this study.
- Full Text:
- Date Issued: 2020
Genetic connectivity in sandy beach macroinfauna with contrasting life histories and zonation patterns
- Authors: Bezuidenhout, Karien
- Date: 2020
- Subjects: Fishes -- Genetics , Seashore ecology -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/45944 , vital:39380
- Description: Open-ocean sandy beaches are highly dynamic ecosystems that continuously respond to waves, tides and storms. These beaches support a suite of uniquely adapted fauna that exhibits a high degree of endemism. This diversity, which also includes some economically important resource species, contributes to the great socio-economic and ecological value of sandy beach systems, which provide ecosystem services such as nutrient recycling and water purification, fish nursery habitat (surf zone), and natural buffering against storms. Despite their broad global distribution comprising ~70 % of the world’s ice-free coastline, beaches are naturally fragmented by other intertidal marine habitats and extensive coastal development. Sea-level rise is now threatening beaches, particularly along developed coasts through coastal squeeze, with an increased risk of habitat loss and exacerbated fragmentation. Such habitat loss has important implications for population and species persistence, depending on the level of connectivity among populations. While sandy beach macroinfauna tend to be highly mobile across and along shore, they also show a strong bias towards direct, or aplanktonic, development; the latter could reduce opportunities for dispersal and sustained population connectivity. However, comparatively little is known about population connectivity on sandy beaches, limiting scientifically sound management of much of the world’s coastline. This study aims to address this knowledge gap by working towards a conceptual model quantifying population connectivity, and by investigating the specific roles of life history, across-shore zonation, and geographic range as putative indicators and possibly drivers of genetic differentiation (ΦST) and connectivity (gene flow) among beach macroinvertebrate populations. The main hypotheses are that 1) species with a pelagic larval stage will display lower genetic differentiation with higher rates of gene flow among populations than species with a benthic lecithotrophic larval stage or direct development; and 2) genetic differentiation among populations will decrease along an across-shore axis, from the supratidal to the low water mark. Two opposing hypotheses were tested concerning the relationship between genetic structure and distributional range: 3a) Species with a large range (measured as distance and number of latitudes) will show less genetic differentiation than those with a narrow range, because they are more able to disperse; or 3b) more widely distributed species may occur across more phylogenetic | v breaks, and thus show higher genetic differentiation than species restricted to a smaller ranges and single biogeographic provinces. First, the extent and likely drivers of population connectivity were investigated for a suite of temperate South African macroinfauna. Very low, non-significant genetic differentiation was demonstrated for the beach clam Donax serra, thus supporting the hypothesis that pelagic larval dispersers display low/no genetic differentiation among populations (Chapter 2). Statistical power of the COI locus was, however, low in this species, due to reduced genetic variability which could be attributed to an expansion from a small source population into extant habitats. The results highlighted the need for caution when interpreting a lack of genetic differentiation as evidence for population connectivity. Nevertheless, COI sequences verified that D. serra occupying the cool and warm-temperate regions of the South African coast, constitute a single species, despite morphological and behavioural differences between inhabitants of these two bioregions. D. sordidus, a congener of D. serra, and endemic to the warm-temperate (Agulhas) bioregion of South Africa, was investigated to test two opposing hypotheses (Chapter 3): 1) this pelagic larval disperser lack genetic differentiation with high rates of gene flow across its range, or alternatively 2) these clams are genetically structured across their range due to the influence of freshwater input (measured as distance to nearest estuary), and morphodynamics of the surf zone (represented by surf-zone width). Significant global ΦST was estimated for D. sordidus, with differentiation predominantly driven by haplotype frequencies at a single study site and estimates of gene flow among most sample locations generally high. Tentative evidence suggested that natural selection driven by differences in water salinity due to estuarine runoff and surf-zone width, might be maintaining two dominant haplotypes across the range of this species. Beach clams from the Southern Hemisphere, occupying different distributional ranges, were compared to test the hypothesis that genetic structure decreases with an increase in range. This hypothesis was poorly supported by the results; opposite (yet mostly non-significant) trends demonstrated for ΦST and haplotype diversity, thus providing some support for the alternative hypothesis that more phylogeographic breaks in broad-ranging species results in higher estimates of genetic structure in these species.
- Full Text:
- Date Issued: 2020
- Authors: Bezuidenhout, Karien
- Date: 2020
- Subjects: Fishes -- Genetics , Seashore ecology -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/45944 , vital:39380
- Description: Open-ocean sandy beaches are highly dynamic ecosystems that continuously respond to waves, tides and storms. These beaches support a suite of uniquely adapted fauna that exhibits a high degree of endemism. This diversity, which also includes some economically important resource species, contributes to the great socio-economic and ecological value of sandy beach systems, which provide ecosystem services such as nutrient recycling and water purification, fish nursery habitat (surf zone), and natural buffering against storms. Despite their broad global distribution comprising ~70 % of the world’s ice-free coastline, beaches are naturally fragmented by other intertidal marine habitats and extensive coastal development. Sea-level rise is now threatening beaches, particularly along developed coasts through coastal squeeze, with an increased risk of habitat loss and exacerbated fragmentation. Such habitat loss has important implications for population and species persistence, depending on the level of connectivity among populations. While sandy beach macroinfauna tend to be highly mobile across and along shore, they also show a strong bias towards direct, or aplanktonic, development; the latter could reduce opportunities for dispersal and sustained population connectivity. However, comparatively little is known about population connectivity on sandy beaches, limiting scientifically sound management of much of the world’s coastline. This study aims to address this knowledge gap by working towards a conceptual model quantifying population connectivity, and by investigating the specific roles of life history, across-shore zonation, and geographic range as putative indicators and possibly drivers of genetic differentiation (ΦST) and connectivity (gene flow) among beach macroinvertebrate populations. The main hypotheses are that 1) species with a pelagic larval stage will display lower genetic differentiation with higher rates of gene flow among populations than species with a benthic lecithotrophic larval stage or direct development; and 2) genetic differentiation among populations will decrease along an across-shore axis, from the supratidal to the low water mark. Two opposing hypotheses were tested concerning the relationship between genetic structure and distributional range: 3a) Species with a large range (measured as distance and number of latitudes) will show less genetic differentiation than those with a narrow range, because they are more able to disperse; or 3b) more widely distributed species may occur across more phylogenetic | v breaks, and thus show higher genetic differentiation than species restricted to a smaller ranges and single biogeographic provinces. First, the extent and likely drivers of population connectivity were investigated for a suite of temperate South African macroinfauna. Very low, non-significant genetic differentiation was demonstrated for the beach clam Donax serra, thus supporting the hypothesis that pelagic larval dispersers display low/no genetic differentiation among populations (Chapter 2). Statistical power of the COI locus was, however, low in this species, due to reduced genetic variability which could be attributed to an expansion from a small source population into extant habitats. The results highlighted the need for caution when interpreting a lack of genetic differentiation as evidence for population connectivity. Nevertheless, COI sequences verified that D. serra occupying the cool and warm-temperate regions of the South African coast, constitute a single species, despite morphological and behavioural differences between inhabitants of these two bioregions. D. sordidus, a congener of D. serra, and endemic to the warm-temperate (Agulhas) bioregion of South Africa, was investigated to test two opposing hypotheses (Chapter 3): 1) this pelagic larval disperser lack genetic differentiation with high rates of gene flow across its range, or alternatively 2) these clams are genetically structured across their range due to the influence of freshwater input (measured as distance to nearest estuary), and morphodynamics of the surf zone (represented by surf-zone width). Significant global ΦST was estimated for D. sordidus, with differentiation predominantly driven by haplotype frequencies at a single study site and estimates of gene flow among most sample locations generally high. Tentative evidence suggested that natural selection driven by differences in water salinity due to estuarine runoff and surf-zone width, might be maintaining two dominant haplotypes across the range of this species. Beach clams from the Southern Hemisphere, occupying different distributional ranges, were compared to test the hypothesis that genetic structure decreases with an increase in range. This hypothesis was poorly supported by the results; opposite (yet mostly non-significant) trends demonstrated for ΦST and haplotype diversity, thus providing some support for the alternative hypothesis that more phylogeographic breaks in broad-ranging species results in higher estimates of genetic structure in these species.
- Full Text:
- Date Issued: 2020
Girls here and boys there : participatory visual methodology as pedagogy to facilitate gender sensitive practices with pre-service foundation phase teachers
- Authors: Notshulwana, Robin Anne
- Date: 2020
- Subjects: Gender identity -- Psychological aspects
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/49385 , vital:41700
- Description: This study explores how participatory visual methodology (PVM) might facilitate a deeper understanding of gender sensitive practices (GSP) in Foundation Phase (FP) pre-service teachers. Foundation Phase classrooms are not impervious to unequal gender practices and despite policies that promote gender equitable practices in schools and in society in general, most South African schools still engage in gendered practices that perpetuate inequality and gender based violence (GBV). While the topic of gender currently features in a South African university FP curriculum with the intention of promoting social justice, the pedagogy used to enable pre-service FP teachers to understand how gender works in schools seems to do nothing more than describe the problem and give cursory suggestions for creating gender equitable practices. Teachers are often unaware of how their own gendered identity influences their facilitation of the curriculum in a gendered way. This is important in South Africa, where gender inequality remains a problem and GBV is rife. This study adopted a qualitative approach and is located within the critical paradigm applying the principles of PVM. It drew on feminist poststructuralism and feminist pedagogy as theoretical lenses to frame the study and to make meaning of the data. Participants in the study were five female pre-service FP teachers who were purposively selected. Data were generated through the visual methods of family photo album, drawing and participatory video, which were first analysed using participatory analysis, and then using thematic analysis. The main purpose of the research was to explore how PVM can facilitate a deeper awareness of GSP in pre-service FP teachers. The secondary aim was to explore their understandings of gender and GSP and how these understandings might facilitate or inhibit GSP among pre-service FP teachers. The pre-service FP teachers’ understandings of gender were elicited using the self as an entry point to explore their own gendered identities which demonstrated their somewhat narrow understanding of how gender is reified in society through mechanisms such as dress and particular performances. They further understood that their own gendered selves can shift and change with time and context. Their understanding of gender further informed their understanding of GSP. The pre-service FP teachers understood GSP as going beyond interchanging roles of girls and boys and that it meant constantly engaging with their own understandings of gender; to review their constructions of FP learners, to see pedagogical moments to teach gender sensitivity, and to recognise that GSP extends beyond the classroom. Finally, the pre-service FP teachers articulated the circumstances that might enable or inhibit their GSP in their classrooms. They recognised how the powerful constructions of gender in a society influence their work, and how, in turn their work might influence society. This translated into them understanding how the ethos of the school might mirror and sustain the hegemonic discourse of society and at the same time how they might begin to question and disrupt the discourse sustained in school. The teacher education programme, with a vested interest in gender equality, is an important mechanism to begin disrupting hegemonic discourses perpetuated in schools. The findings suggest that through its potential for reflexivity and criticality, PVM enabled the pre-service FP teachers to see how their constructions of gender influence their own practices in schools. The findings have implications for FP teacher education programmes in the South African context. Faculties of education could revisit their curriculum to ensure that gender is infused throughout the curriculum, but more importantly, could consider ‘starting with the self’ (Kirk, 2009) as an impetus to learn about how gender is reified in society and in schools. In doing so, faculties of education could also consider tools of analysis such as a feminist poststructural theory to enable the pre-service FP teachers to deepen their understandings but also support the potential to articulate and make meaning of their experiences. Teacher educators could revisit their curriculum content to determine whether the content might perpetuate a narrow view of learning and learners especially with regards to gender and considering pedagogical choices that develop pre-service teachers’ ability to cultivate classroom environments that promote gender equality. Starting with the self is an entry point for pre-service FP teachers to examine their own understanding of gender and see how this might enable GSP in their professional work. PVM, aligned with a feminist pedagogy and feminist poststructuralism, facilitated such a process.
- Full Text:
- Date Issued: 2020
- Authors: Notshulwana, Robin Anne
- Date: 2020
- Subjects: Gender identity -- Psychological aspects
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/49385 , vital:41700
- Description: This study explores how participatory visual methodology (PVM) might facilitate a deeper understanding of gender sensitive practices (GSP) in Foundation Phase (FP) pre-service teachers. Foundation Phase classrooms are not impervious to unequal gender practices and despite policies that promote gender equitable practices in schools and in society in general, most South African schools still engage in gendered practices that perpetuate inequality and gender based violence (GBV). While the topic of gender currently features in a South African university FP curriculum with the intention of promoting social justice, the pedagogy used to enable pre-service FP teachers to understand how gender works in schools seems to do nothing more than describe the problem and give cursory suggestions for creating gender equitable practices. Teachers are often unaware of how their own gendered identity influences their facilitation of the curriculum in a gendered way. This is important in South Africa, where gender inequality remains a problem and GBV is rife. This study adopted a qualitative approach and is located within the critical paradigm applying the principles of PVM. It drew on feminist poststructuralism and feminist pedagogy as theoretical lenses to frame the study and to make meaning of the data. Participants in the study were five female pre-service FP teachers who were purposively selected. Data were generated through the visual methods of family photo album, drawing and participatory video, which were first analysed using participatory analysis, and then using thematic analysis. The main purpose of the research was to explore how PVM can facilitate a deeper awareness of GSP in pre-service FP teachers. The secondary aim was to explore their understandings of gender and GSP and how these understandings might facilitate or inhibit GSP among pre-service FP teachers. The pre-service FP teachers’ understandings of gender were elicited using the self as an entry point to explore their own gendered identities which demonstrated their somewhat narrow understanding of how gender is reified in society through mechanisms such as dress and particular performances. They further understood that their own gendered selves can shift and change with time and context. Their understanding of gender further informed their understanding of GSP. The pre-service FP teachers understood GSP as going beyond interchanging roles of girls and boys and that it meant constantly engaging with their own understandings of gender; to review their constructions of FP learners, to see pedagogical moments to teach gender sensitivity, and to recognise that GSP extends beyond the classroom. Finally, the pre-service FP teachers articulated the circumstances that might enable or inhibit their GSP in their classrooms. They recognised how the powerful constructions of gender in a society influence their work, and how, in turn their work might influence society. This translated into them understanding how the ethos of the school might mirror and sustain the hegemonic discourse of society and at the same time how they might begin to question and disrupt the discourse sustained in school. The teacher education programme, with a vested interest in gender equality, is an important mechanism to begin disrupting hegemonic discourses perpetuated in schools. The findings suggest that through its potential for reflexivity and criticality, PVM enabled the pre-service FP teachers to see how their constructions of gender influence their own practices in schools. The findings have implications for FP teacher education programmes in the South African context. Faculties of education could revisit their curriculum to ensure that gender is infused throughout the curriculum, but more importantly, could consider ‘starting with the self’ (Kirk, 2009) as an impetus to learn about how gender is reified in society and in schools. In doing so, faculties of education could also consider tools of analysis such as a feminist poststructural theory to enable the pre-service FP teachers to deepen their understandings but also support the potential to articulate and make meaning of their experiences. Teacher educators could revisit their curriculum content to determine whether the content might perpetuate a narrow view of learning and learners especially with regards to gender and considering pedagogical choices that develop pre-service teachers’ ability to cultivate classroom environments that promote gender equality. Starting with the self is an entry point for pre-service FP teachers to examine their own understanding of gender and see how this might enable GSP in their professional work. PVM, aligned with a feminist pedagogy and feminist poststructuralism, facilitated such a process.
- Full Text:
- Date Issued: 2020
History on trial: a study of the Salem commonage land claim
- Authors: Bezuidenhout, GJW
- Date: 2020
- Subjects: South Africa. Restitution of Land Rights Act, 1994 , Salem (South Africa) -- History , Land tenure -- Law and legilstion -- South Africa , Land reform -- Law and legislation -- South Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/146647 , vital:38545
- Description: This thesis critically examines the Salem commonage claim, a dispute that has shaken the hamlet of Salem to its core. On ground level it has caused racialized fault lines to reopen, while suspicion and distrust has also grown between the black Africans of the area as well. On a national level, the Constitutional Court judgement has potentially set a precedent with regards to its jurisprudential approach in determining the validity of land claims in South Africa. Its interpretation of the law was determined by the restorative justice jurisprudence enshrined in the Restitution of Land Rights Act 22 of 1994 (the Act). It based its own understanding of the history of the commonage on this jurisprudence. In a bold step towards realising the aims and purposes of the Act, the Constitutional Court found that both the black African claimants as well as the white landowners have equal rights to the land. One of the reasons why the decision of the Constitutional Court is ground-breaking is that the dispute involves a former commonage – land used for common purpose. The Constitutional Court emphasised that the Act was an “extraordinary piece of legislation” and had to be interpreted in such a way so as to address the injustices of the past. This included provisions of the Act which dealt with how oral testimonies from claimants would be dealt with. Another interesting feature was the heavy reliance by all parties on expert witnesses in the persons of eminent historians, Professors Martin Legassick and Herman Giliomee. This case gave much-needed clarification as to what the appropriate role of an expert historian witness may be in a land claim. The success or failure of land claims often depend on the weight of the evidence supplied by the expert historian witness. But the historian must also take cognisance of the fact that the evidence s/he gives is appropriate according to the scope of law. This case also dismisses the assumption that colonial instruments of land assignation are beyond reproach. These instruments which grant rights to land may also be scrutinised in a court of law, just like when oral testimony is tested for its credibility. This is important to note, especially when balancing land rights of the claimants against those of the landowners. This thesis agrees with the decision taken by the Constitutional Court in this instance. However, it also cautions that such softly-softly approaches may appear as a suitable compromise on paper, but the feeling on the ground may not be as receptive to reconciliation as what the courts would have hoped for. To the jurist, this judgement accurately encapsulates the purpose and aims of the Act. However, such a judgement may not seem satisfactory to the people of Salem. The decisions of the Salem commonage case are sure to inform the discourse of land claims in South Africa.
- Full Text:
- Date Issued: 2020
- Authors: Bezuidenhout, GJW
- Date: 2020
- Subjects: South Africa. Restitution of Land Rights Act, 1994 , Salem (South Africa) -- History , Land tenure -- Law and legilstion -- South Africa , Land reform -- Law and legislation -- South Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/146647 , vital:38545
- Description: This thesis critically examines the Salem commonage claim, a dispute that has shaken the hamlet of Salem to its core. On ground level it has caused racialized fault lines to reopen, while suspicion and distrust has also grown between the black Africans of the area as well. On a national level, the Constitutional Court judgement has potentially set a precedent with regards to its jurisprudential approach in determining the validity of land claims in South Africa. Its interpretation of the law was determined by the restorative justice jurisprudence enshrined in the Restitution of Land Rights Act 22 of 1994 (the Act). It based its own understanding of the history of the commonage on this jurisprudence. In a bold step towards realising the aims and purposes of the Act, the Constitutional Court found that both the black African claimants as well as the white landowners have equal rights to the land. One of the reasons why the decision of the Constitutional Court is ground-breaking is that the dispute involves a former commonage – land used for common purpose. The Constitutional Court emphasised that the Act was an “extraordinary piece of legislation” and had to be interpreted in such a way so as to address the injustices of the past. This included provisions of the Act which dealt with how oral testimonies from claimants would be dealt with. Another interesting feature was the heavy reliance by all parties on expert witnesses in the persons of eminent historians, Professors Martin Legassick and Herman Giliomee. This case gave much-needed clarification as to what the appropriate role of an expert historian witness may be in a land claim. The success or failure of land claims often depend on the weight of the evidence supplied by the expert historian witness. But the historian must also take cognisance of the fact that the evidence s/he gives is appropriate according to the scope of law. This case also dismisses the assumption that colonial instruments of land assignation are beyond reproach. These instruments which grant rights to land may also be scrutinised in a court of law, just like when oral testimony is tested for its credibility. This is important to note, especially when balancing land rights of the claimants against those of the landowners. This thesis agrees with the decision taken by the Constitutional Court in this instance. However, it also cautions that such softly-softly approaches may appear as a suitable compromise on paper, but the feeling on the ground may not be as receptive to reconciliation as what the courts would have hoped for. To the jurist, this judgement accurately encapsulates the purpose and aims of the Act. However, such a judgement may not seem satisfactory to the people of Salem. The decisions of the Salem commonage case are sure to inform the discourse of land claims in South Africa.
- Full Text:
- Date Issued: 2020
Household food insecurity and its association with psychological well-being of pregnant women in Ghana: the role of selected psychosocial factors
- Authors: Addai, Prince
- Date: 2020
- Subjects: Food security -- Ghana Households -- Ghana Self-reliance
- Language: English
- Type: Thesis , Doctoral , PhD (Industrial Psychology)
- Identifier: http://hdl.handle.net/10353/12547 , vital:39286
- Description: The inability to get enough food has contributed immensely to dangers confronting pregnant women, especially in the developing countries. Food insecurity has been associated with a variety of negative consequences such as poor health and wellbeing. However, the impact of food insecurity on well-being has not received the needed attention by researchers in Sub-Saharan Africa where the state of food insecurity and its consequence is very pandemic. The objective of this study was to assess the impact of food insecurity on psychological well-being and its components among pregnant women in Northern Ghana and to assess the roles of self-esteem, locus of control, proactivity, and social support on the underlying relationship. The cross-sectional survey was adopted where 386 pregnant women were recruited to complete questionnaires on demographic, some psychological factors, psychological well-being and food insecurity. Dimensionality and Item analyses were conducted to detect complex and poor items and also to ensure unidimensionality. Regression analysis, MANOVA, Baron and Kenney Model of moderation and mediation, the multivariate ANOVA and the Two-way ANOVA were used to test the hypotheses. Results indicated that the measurement and the structural models showed a good fit with the observed data. Results showed that about 37.5% (n=144) out of the 384 pregnant women experienced severe food insecurity. Food insecurity was negatively significantly related with psychological well-being and all its components among pregnant women. Food insecurity elucidated 48.5% of the observed variance of food insecurity. Food insecurity correlated highly to personal growth (β = -.327) element of psychological well-being compared to autonomy (β = -.227), interpersonal relationship (β = -.207), environmental mastery (β = -.168), self-acceptance (β = -.117), and of purpose in life (β = -.107). Self-esteem and locus of control mediated the relationship between food insecurity and psychological well-being. Proactivity and social support also moderated the nexus between food insecurity and psychological well-being. 4 Final Submission of Thesis, Dissertation or Research Report/Project, Conference or Exam Paper Having higher income status and being employed were associated positively with higher psychological well-being. Support was not found for the nexus between marital status and age with psychological well-being. Recommendations are made for pregnant mothers to be supported and empowered to boost their self-esteem and make them proactive.
- Full Text:
- Date Issued: 2020
- Authors: Addai, Prince
- Date: 2020
- Subjects: Food security -- Ghana Households -- Ghana Self-reliance
- Language: English
- Type: Thesis , Doctoral , PhD (Industrial Psychology)
- Identifier: http://hdl.handle.net/10353/12547 , vital:39286
- Description: The inability to get enough food has contributed immensely to dangers confronting pregnant women, especially in the developing countries. Food insecurity has been associated with a variety of negative consequences such as poor health and wellbeing. However, the impact of food insecurity on well-being has not received the needed attention by researchers in Sub-Saharan Africa where the state of food insecurity and its consequence is very pandemic. The objective of this study was to assess the impact of food insecurity on psychological well-being and its components among pregnant women in Northern Ghana and to assess the roles of self-esteem, locus of control, proactivity, and social support on the underlying relationship. The cross-sectional survey was adopted where 386 pregnant women were recruited to complete questionnaires on demographic, some psychological factors, psychological well-being and food insecurity. Dimensionality and Item analyses were conducted to detect complex and poor items and also to ensure unidimensionality. Regression analysis, MANOVA, Baron and Kenney Model of moderation and mediation, the multivariate ANOVA and the Two-way ANOVA were used to test the hypotheses. Results indicated that the measurement and the structural models showed a good fit with the observed data. Results showed that about 37.5% (n=144) out of the 384 pregnant women experienced severe food insecurity. Food insecurity was negatively significantly related with psychological well-being and all its components among pregnant women. Food insecurity elucidated 48.5% of the observed variance of food insecurity. Food insecurity correlated highly to personal growth (β = -.327) element of psychological well-being compared to autonomy (β = -.227), interpersonal relationship (β = -.207), environmental mastery (β = -.168), self-acceptance (β = -.117), and of purpose in life (β = -.107). Self-esteem and locus of control mediated the relationship between food insecurity and psychological well-being. Proactivity and social support also moderated the nexus between food insecurity and psychological well-being. 4 Final Submission of Thesis, Dissertation or Research Report/Project, Conference or Exam Paper Having higher income status and being employed were associated positively with higher psychological well-being. Support was not found for the nexus between marital status and age with psychological well-being. Recommendations are made for pregnant mothers to be supported and empowered to boost their self-esteem and make them proactive.
- Full Text:
- Date Issued: 2020
How to do things with speeches: a critical discourse analysis of military coup texts in Nigeria
- Authors: Bello, Umar
- Date: 2020
- Subjects: Speeches, addresses, etc., Nigerian -- 20th century -- History and criticism , Critical discourse analysis -- Nigeria , Corpora (Linguistics) , Social sciences -- Philosophy , Intertextuality , Interpellation -- Nigeria , Forensics (Public speaking) , Oratory -- Nigeria , Nigeria -- Politics and government -- 1960- , Nigeria -- Social conditions -- 1960-
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/143336 , vital:38234
- Description: Coup speeches that usher the military into political power in Nigeria are the central focus of this thesis. There are seven coup speeches that are notable in the changing of the political course in Nigeria and in enabling the military to rule Nigeria for 30 years, establishing another alternative political construct and party (Bangura 1991). The seven coup speeches along with two others, one a colonial proclamation of conquest and the other a counter coup speech (altogether making nine) constitute the data of this thesis. The analysis done here uses Critical Discourse Analysis, based on a combination of Fairclough (1989, 2001), Fairclough and Fairclough (2012), Thompson’s (1984, 1988 and 1990) works with complementary insights by Chilton (2004), to analyze the speeches in order to understand the ideologies, perceptions and arguments of the coup makers enshrined in the texts. I also employ a concordance analytic system in corpus linguistics to sort uses of important terms and lexical items. The analysis is divided into three broad parts, namely: an analysis of representation of social actors and their action, an analysis of the processes of interpellation and then an analysis of the premises of the arguments contained in the speeches. In the concluding part, there is a discussion of the dialectical nature of the coup speeches especially in the areas of mutual influences which aids in the gradual sedimentation of the political ideology of the military. In particular, there is a longitudinal intertextual analysis across all the speeches, from the earliest to the latest, to see how a coup speech genre is created. The contribution of this work to knowledge is in terms of combining discourse analysis and social theory to illuminate some aspects of Nigeria’s socio- political crises in depth and multifariously. This work helps in understanding the nature of Nigerian autocratic democracy, subservient followership by the citizenry and the supremacy of the military elite. The work employs a novel combination of representation, argumentation, interpellation and constitutive intertextuality in understanding military discourse. It looks at speaker intention, the exploitation of interpretation or reception and the formation of subjects in general and each with its importance and social context. The work as a whole reveals that the military try to build legitimacy by way of establishing authority through rhetorical arguments in varying degrees. These arguments are laid bare, and what they discern is that charges are decidedly trumped up by the military against their opponents and constructed to suit the spin of their moments. The coup makers in some instances construct strawmen of opponents and then go ahead to attack their constructed assumptions or they charge without substance using nominalizations, metaphorical constructions and presuppositions. They apply stipulative definitions and emotionally loaded words in evaluating their actions favourably and also in the negative evaluation of the actions of the opponents. At the level of interpellational analysis, the data reveals the use of language in gradually hailing the citizens as military subjects. The role of the audience changes here i.e. from those to be convinced in rhetorical evaluation of opponents to those to be firmly controlled. The persistent hailing and positioning of the citizens as military subjects help in concretizing their subjecthood. The reaction of the people in affirmation of support to the rule of the military is crucial and it completes the interpellation process. As observed by Clark (2007, 141) “many African societies are so inured to military intervention as not to regard it as aberrant”. This inuring of the societies has to do with hegemonic ideological practices in military discourses claiming legitimacy and the right to rule. At the reception level, this shows that most of the citizens have bought into the dominant ideology and are as such interpellated by it or have adopted what Hall (2015, 125) would call the ‘dominant-hegemonic position’. Aspects of argumentation, speech acts, and deontic modals used by the coup makers help in gradually solidifying the subservient nature of the citizens to the military junta. The diachronic and intertextual nature of the analysis also reveals that the colonial proclamation of conquest in Nigeria by Lord Fredrick Lugard possibly influenced the first coup speech in 1966 in terms of structure and genre. There are traces of the colonial proclamations found in the 1966 coup speech. In substance, the military appear to copy their colonial progenitors. Historically, the military were formed as an army of colonial conquest. There is a dialectical interplay between colonial discourse and military coup speeches. The first coup speech, for its part, influences other coup speeches and they in general impact on civilian political language. The work analyzes from the minute to the global and in this bid unties the layers of assumptions, constructions and points of views that underpin an otherwise objective presentation of reality. The study also engages social theory in illuminating aspects of discourse, social practice and political action. The works of post-structuralists like Foucault, Althusser, Bourdieu, Habermas, Laclau and Mouffe, Derrida etc. are employed in shedding light on the processes of social formation in the interpellation of subjects and in the construction of a new political authority by the military regimes.
- Full Text:
- Date Issued: 2020
- Authors: Bello, Umar
- Date: 2020
- Subjects: Speeches, addresses, etc., Nigerian -- 20th century -- History and criticism , Critical discourse analysis -- Nigeria , Corpora (Linguistics) , Social sciences -- Philosophy , Intertextuality , Interpellation -- Nigeria , Forensics (Public speaking) , Oratory -- Nigeria , Nigeria -- Politics and government -- 1960- , Nigeria -- Social conditions -- 1960-
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/143336 , vital:38234
- Description: Coup speeches that usher the military into political power in Nigeria are the central focus of this thesis. There are seven coup speeches that are notable in the changing of the political course in Nigeria and in enabling the military to rule Nigeria for 30 years, establishing another alternative political construct and party (Bangura 1991). The seven coup speeches along with two others, one a colonial proclamation of conquest and the other a counter coup speech (altogether making nine) constitute the data of this thesis. The analysis done here uses Critical Discourse Analysis, based on a combination of Fairclough (1989, 2001), Fairclough and Fairclough (2012), Thompson’s (1984, 1988 and 1990) works with complementary insights by Chilton (2004), to analyze the speeches in order to understand the ideologies, perceptions and arguments of the coup makers enshrined in the texts. I also employ a concordance analytic system in corpus linguistics to sort uses of important terms and lexical items. The analysis is divided into three broad parts, namely: an analysis of representation of social actors and their action, an analysis of the processes of interpellation and then an analysis of the premises of the arguments contained in the speeches. In the concluding part, there is a discussion of the dialectical nature of the coup speeches especially in the areas of mutual influences which aids in the gradual sedimentation of the political ideology of the military. In particular, there is a longitudinal intertextual analysis across all the speeches, from the earliest to the latest, to see how a coup speech genre is created. The contribution of this work to knowledge is in terms of combining discourse analysis and social theory to illuminate some aspects of Nigeria’s socio- political crises in depth and multifariously. This work helps in understanding the nature of Nigerian autocratic democracy, subservient followership by the citizenry and the supremacy of the military elite. The work employs a novel combination of representation, argumentation, interpellation and constitutive intertextuality in understanding military discourse. It looks at speaker intention, the exploitation of interpretation or reception and the formation of subjects in general and each with its importance and social context. The work as a whole reveals that the military try to build legitimacy by way of establishing authority through rhetorical arguments in varying degrees. These arguments are laid bare, and what they discern is that charges are decidedly trumped up by the military against their opponents and constructed to suit the spin of their moments. The coup makers in some instances construct strawmen of opponents and then go ahead to attack their constructed assumptions or they charge without substance using nominalizations, metaphorical constructions and presuppositions. They apply stipulative definitions and emotionally loaded words in evaluating their actions favourably and also in the negative evaluation of the actions of the opponents. At the level of interpellational analysis, the data reveals the use of language in gradually hailing the citizens as military subjects. The role of the audience changes here i.e. from those to be convinced in rhetorical evaluation of opponents to those to be firmly controlled. The persistent hailing and positioning of the citizens as military subjects help in concretizing their subjecthood. The reaction of the people in affirmation of support to the rule of the military is crucial and it completes the interpellation process. As observed by Clark (2007, 141) “many African societies are so inured to military intervention as not to regard it as aberrant”. This inuring of the societies has to do with hegemonic ideological practices in military discourses claiming legitimacy and the right to rule. At the reception level, this shows that most of the citizens have bought into the dominant ideology and are as such interpellated by it or have adopted what Hall (2015, 125) would call the ‘dominant-hegemonic position’. Aspects of argumentation, speech acts, and deontic modals used by the coup makers help in gradually solidifying the subservient nature of the citizens to the military junta. The diachronic and intertextual nature of the analysis also reveals that the colonial proclamation of conquest in Nigeria by Lord Fredrick Lugard possibly influenced the first coup speech in 1966 in terms of structure and genre. There are traces of the colonial proclamations found in the 1966 coup speech. In substance, the military appear to copy their colonial progenitors. Historically, the military were formed as an army of colonial conquest. There is a dialectical interplay between colonial discourse and military coup speeches. The first coup speech, for its part, influences other coup speeches and they in general impact on civilian political language. The work analyzes from the minute to the global and in this bid unties the layers of assumptions, constructions and points of views that underpin an otherwise objective presentation of reality. The study also engages social theory in illuminating aspects of discourse, social practice and political action. The works of post-structuralists like Foucault, Althusser, Bourdieu, Habermas, Laclau and Mouffe, Derrida etc. are employed in shedding light on the processes of social formation in the interpellation of subjects and in the construction of a new political authority by the military regimes.
- Full Text:
- Date Issued: 2020