The role of computational thinking in introductory computer science
- Authors: Gouws, Lindsey Ann
- Date: 2014
- Subjects: Computer science , Computational complexity , Problem solving -- Study and teaching
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4690 , http://hdl.handle.net/10962/d1011152 , Computer science , Computational complexity , Problem solving -- Study and teaching
- Description: Computational thinking (CT) is gaining recognition as an important skill for students, both in computer science and other disciplines. Although there has been much focus on this field in recent years, it is rarely taught as a formal course, and there is little consensus on what exactly CT entails and how to teach and evaluate it. This research addresses the lack of resources for integrating CT into the introductory computer science curriculum. The question that we aim to answer is whether CT can be evaluated in a meaningful way. A CT framework that outlines the skills and techniques comprising CT and describes the nature of student engagement was developed; this is used as the basis for this research. An assessment (CT test) was then created to gauge the ability of incoming students, and a CT-specfic computer game was developed based on the analysis of an existing game. A set of problem solving strategies and practice activities were then recommended based on criteria defined in the framework. The results revealed that the CT abilities of first year university students are relatively poor, but that the students' scores for the CT test could be used as a predictor for their future success in computer science courses. The framework developed for this research proved successful when applied to the test, computer game evaluation, and classification of strategies and activities. Through this research, we established that CT is a skill that first year computer science students are lacking, and that using CT exercises alongside traditional programming instruction can improve students' learning experiences.
- Full Text:
- Date Issued: 2014
- Authors: Gouws, Lindsey Ann
- Date: 2014
- Subjects: Computer science , Computational complexity , Problem solving -- Study and teaching
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4690 , http://hdl.handle.net/10962/d1011152 , Computer science , Computational complexity , Problem solving -- Study and teaching
- Description: Computational thinking (CT) is gaining recognition as an important skill for students, both in computer science and other disciplines. Although there has been much focus on this field in recent years, it is rarely taught as a formal course, and there is little consensus on what exactly CT entails and how to teach and evaluate it. This research addresses the lack of resources for integrating CT into the introductory computer science curriculum. The question that we aim to answer is whether CT can be evaluated in a meaningful way. A CT framework that outlines the skills and techniques comprising CT and describes the nature of student engagement was developed; this is used as the basis for this research. An assessment (CT test) was then created to gauge the ability of incoming students, and a CT-specfic computer game was developed based on the analysis of an existing game. A set of problem solving strategies and practice activities were then recommended based on criteria defined in the framework. The results revealed that the CT abilities of first year university students are relatively poor, but that the students' scores for the CT test could be used as a predictor for their future success in computer science courses. The framework developed for this research proved successful when applied to the test, computer game evaluation, and classification of strategies and activities. Through this research, we established that CT is a skill that first year computer science students are lacking, and that using CT exercises alongside traditional programming instruction can improve students' learning experiences.
- Full Text:
- Date Issued: 2014
The role of the deep spawning grounds in chokka squid (Loligo reynaudi d'orbigny, 1845) recruitment
- Authors: Downey, Nicola Jean
- Date: 2014
- Subjects: Squids -- Spawning -- South Africa Squids -- Effect of temperature on -- South Africa Squids -- Embryos -- South Africa Squids -- South Africa -- Geographical distribution Loligo -- Research -- South Africa Loligo fisheries -- South Africa Recruitment (Population biology) -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5359 , http://hdl.handle.net/10962/d1011867
- Description: It was previously thought that the South African chokka squid Loligo reynaudi is exclusively an inshore, shallow water spawner. Although spawning mostly within shallow bays (<60 m) the presence of squid eggs in trawls at depths up to 130 m indicates this species frequently makes use of deeper spawning areas on the mid-shelf. The extent of mid-shelf spawning (referred to as deep spawning) and the contribution to recruitment has yet to be assessed. Studies have shown mid-shelf bottom temperature to vary considerably from those inshore, suggesting chokka squid spawn in two very different oceanographic environments. Considering these apparent environmental differences, what leads to the mid-shelf environment becoming a suitable spawning habitat? Does a suitable benthic habitat, required for the attachment of egg pods, occur on the mid-shelf? These questions are not only important for determining the extent of deep spawning, but also to the understanding of factors “driving” deep spawning. The fate of deep spawned hatchlings is another unknown. It has been proposed that the main chokka squid inshore spawning grounds are positioned to exploit the net westward currents on the Eastern Agulhas Bank, i.e. paralarvae would be transported west from the hatching site to the cold ridge, an area of high primary and secondary productivity on the Central Agulhas Bank. This concept has come to be known as the Western Transport Hypothesis. Lagrangian ROMS-IBMs (regional ocean model system – individual-based model) predict the net westward transport of paralarvae from both the inshore and deep spawning grounds, to the cold ridge. These simulations were used to investigate the transport of hatchlings to the cold ridge feeding grounds before the exhaustion of yolk reserves. The fate of paralarvae on reaching the feeding grounds has not yet been investigated. This work has contributed new knowledge to our understanding of deep spawning and its role in recruitment. Specific aims of this study were to (1) determine the extent, range and importance of the deep spawning grounds relative to those inshore; (2) investigate the deep spawning ground habitat (Agulhas Bank mid-shelf) morphology and oceanographic environment; (3) determine the transport and survival of deep spawned hatchlings; and (4) investigate the origin and distribution of chokka squid paralarvae on the Agulhas Bank. The extent, depth range and importance of the deep spawning grounds, relative to those inshore was assessed using 23 years of demersal trawl survey data. Data for both the west and south coasts of South Africa were examined for egg capsules. No spawning was found on the west coast. Data showed that chokka squid preferred the Eastern Agulhas Bank for spawning. Spawning occurred not only inshore but also on the mid-shelf extending to depths of 270 m near the shelf edge. The majority of deep spawned eggs however, were found in the depth range 71-130 m. Squid egg density markedly decreased beyond 70 m, suggesting delineation between the inshore and deep spawning grounds. Total egg biomass calculations for depths shallower and deeper than 70 m indicated the coastal area to be strongly favoured, i.e. 82 vs. 18%. These results contest the commonly accepted notion that chokka squid is an inshore spawner and redefine the spawning grounds to extend across the shelf. Apart from an initial study investigating bottom temperature on the mid-shelf, very little is known about the deep spawning habitat. St Francis Bay, a commonly used spawning location, was chosen as a demonstration area for further study. The deep spawning grounds (71-130 m) were mapped and benthic habitat described from underwater video footage. A study investigating cross-shelf bottom conditions was undertaken off Thys Bay. CTD data were used to compare seasonal bottom temperature and oxygen on the St Francis Bay inshore and deep spawning grounds. Squid movement between the two spawning habitats was assessed using filament tagging. Predation and fishing pressure across the spawning grounds was reviewed. The mid-shelf benthic habitat was found to be similar to that inshore and available for spawning. Despite the generally colder bottom temperatures on the mid-shelf, this study showed that bottom temperature in deeper waters can at times be warmer than inshore. Although mid-shelf warming events lasted from a few hours to a number of days, they resulted in similar conditions to those on the inshore spawning grounds. It is likely these events act to expand or shift spawning habitat. The movement of squid between the two spawning habitats makes it possible for them to seek patches of warm bottom water with appropiate substrate. This suggests they are spawning habitat opportunists. Predation and fishing pressure appear to be higher on the inshore spawning grounds. It is feasible that this also forces spawners to seek out more favourable habitat offshore. An individual-based model was used to predict the fate of mid-shelf and inshore hatched paralarvae. Within the model, both the highly productive cold ridge and inshore spawning grounds were considered feeding or nursery areas. Paralarvae were released from six inshore and six deep spawning sites, spanning the coast between Port Alfred and Knysna. All paralarvae not reaching the feeding areas before the exhaustion of yolk-reserves (≤5 days), not retained within the feeding grounds (≥14 days), and not retained on the Agulhas Bank after exiting the feeding grounds were considered lost. This work illustrated the dependence of paralarval transport success on both spawning location and time of hatching, as established in earlier studies. The current IBM has expanded on initial work, emphasizing the importance of the cold ridge and inshore spawning grounds as nursery areas for deep and inshore spawned paralarvae, respectively. This work has highlighted the complex interactions between processes influencing recruitment variability for chokka squid. Possible relationships between periods of highest recruitment success and spawning peaks were identified for both spawning habitats. Based on the likely autumn increase in deep spawning off Tsitsikamma, and the beneficial currents during this period, it can be concluded deep spawning may at times contribute significantly to recruitment. This is particularly true for years where the cold ridge persists into winter. Data on chokka squid paralarval distribution are scarce. Paralarval distribution and abundance, in relation to Agulhas Bank oceanography, was investigated using bongo caught paralarvae and corresponding oceanographic data. Individual-based models (IBMs) were used to predict the origin or spawning site of the wild caught paralarvae, with reference to inshore versus deep spawning. Although failing to predict realistic points of origin, this study provided evidence to support a number of scenarios previously assumed to influence chokka squid recruitment. First is the possible influence of coastal upwelling on the retention, and hence spatial distribution, of paralarvae on the inshore spawning grounds. The second factor thought to impact recruitment is the loss of paralarvae from the Agulhas Bank ecosystem. This study confirmed the removal of paralarvae from the Eastern Agulhas Bank due to Agulhas Current boundary phenomena and resultant offshelf leakage. In addition, data suggested that the formation of the cold ridge could enhance retention on the Central Agulhas Bank, and so prevent offshelf leakage from the Central and Western Agulhas Bank. A synthesis of the main conclusions is presented. Implications of the findings and directions for future research are discussed.
- Full Text:
- Date Issued: 2014
- Authors: Downey, Nicola Jean
- Date: 2014
- Subjects: Squids -- Spawning -- South Africa Squids -- Effect of temperature on -- South Africa Squids -- Embryos -- South Africa Squids -- South Africa -- Geographical distribution Loligo -- Research -- South Africa Loligo fisheries -- South Africa Recruitment (Population biology) -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5359 , http://hdl.handle.net/10962/d1011867
- Description: It was previously thought that the South African chokka squid Loligo reynaudi is exclusively an inshore, shallow water spawner. Although spawning mostly within shallow bays (<60 m) the presence of squid eggs in trawls at depths up to 130 m indicates this species frequently makes use of deeper spawning areas on the mid-shelf. The extent of mid-shelf spawning (referred to as deep spawning) and the contribution to recruitment has yet to be assessed. Studies have shown mid-shelf bottom temperature to vary considerably from those inshore, suggesting chokka squid spawn in two very different oceanographic environments. Considering these apparent environmental differences, what leads to the mid-shelf environment becoming a suitable spawning habitat? Does a suitable benthic habitat, required for the attachment of egg pods, occur on the mid-shelf? These questions are not only important for determining the extent of deep spawning, but also to the understanding of factors “driving” deep spawning. The fate of deep spawned hatchlings is another unknown. It has been proposed that the main chokka squid inshore spawning grounds are positioned to exploit the net westward currents on the Eastern Agulhas Bank, i.e. paralarvae would be transported west from the hatching site to the cold ridge, an area of high primary and secondary productivity on the Central Agulhas Bank. This concept has come to be known as the Western Transport Hypothesis. Lagrangian ROMS-IBMs (regional ocean model system – individual-based model) predict the net westward transport of paralarvae from both the inshore and deep spawning grounds, to the cold ridge. These simulations were used to investigate the transport of hatchlings to the cold ridge feeding grounds before the exhaustion of yolk reserves. The fate of paralarvae on reaching the feeding grounds has not yet been investigated. This work has contributed new knowledge to our understanding of deep spawning and its role in recruitment. Specific aims of this study were to (1) determine the extent, range and importance of the deep spawning grounds relative to those inshore; (2) investigate the deep spawning ground habitat (Agulhas Bank mid-shelf) morphology and oceanographic environment; (3) determine the transport and survival of deep spawned hatchlings; and (4) investigate the origin and distribution of chokka squid paralarvae on the Agulhas Bank. The extent, depth range and importance of the deep spawning grounds, relative to those inshore was assessed using 23 years of demersal trawl survey data. Data for both the west and south coasts of South Africa were examined for egg capsules. No spawning was found on the west coast. Data showed that chokka squid preferred the Eastern Agulhas Bank for spawning. Spawning occurred not only inshore but also on the mid-shelf extending to depths of 270 m near the shelf edge. The majority of deep spawned eggs however, were found in the depth range 71-130 m. Squid egg density markedly decreased beyond 70 m, suggesting delineation between the inshore and deep spawning grounds. Total egg biomass calculations for depths shallower and deeper than 70 m indicated the coastal area to be strongly favoured, i.e. 82 vs. 18%. These results contest the commonly accepted notion that chokka squid is an inshore spawner and redefine the spawning grounds to extend across the shelf. Apart from an initial study investigating bottom temperature on the mid-shelf, very little is known about the deep spawning habitat. St Francis Bay, a commonly used spawning location, was chosen as a demonstration area for further study. The deep spawning grounds (71-130 m) were mapped and benthic habitat described from underwater video footage. A study investigating cross-shelf bottom conditions was undertaken off Thys Bay. CTD data were used to compare seasonal bottom temperature and oxygen on the St Francis Bay inshore and deep spawning grounds. Squid movement between the two spawning habitats was assessed using filament tagging. Predation and fishing pressure across the spawning grounds was reviewed. The mid-shelf benthic habitat was found to be similar to that inshore and available for spawning. Despite the generally colder bottom temperatures on the mid-shelf, this study showed that bottom temperature in deeper waters can at times be warmer than inshore. Although mid-shelf warming events lasted from a few hours to a number of days, they resulted in similar conditions to those on the inshore spawning grounds. It is likely these events act to expand or shift spawning habitat. The movement of squid between the two spawning habitats makes it possible for them to seek patches of warm bottom water with appropiate substrate. This suggests they are spawning habitat opportunists. Predation and fishing pressure appear to be higher on the inshore spawning grounds. It is feasible that this also forces spawners to seek out more favourable habitat offshore. An individual-based model was used to predict the fate of mid-shelf and inshore hatched paralarvae. Within the model, both the highly productive cold ridge and inshore spawning grounds were considered feeding or nursery areas. Paralarvae were released from six inshore and six deep spawning sites, spanning the coast between Port Alfred and Knysna. All paralarvae not reaching the feeding areas before the exhaustion of yolk-reserves (≤5 days), not retained within the feeding grounds (≥14 days), and not retained on the Agulhas Bank after exiting the feeding grounds were considered lost. This work illustrated the dependence of paralarval transport success on both spawning location and time of hatching, as established in earlier studies. The current IBM has expanded on initial work, emphasizing the importance of the cold ridge and inshore spawning grounds as nursery areas for deep and inshore spawned paralarvae, respectively. This work has highlighted the complex interactions between processes influencing recruitment variability for chokka squid. Possible relationships between periods of highest recruitment success and spawning peaks were identified for both spawning habitats. Based on the likely autumn increase in deep spawning off Tsitsikamma, and the beneficial currents during this period, it can be concluded deep spawning may at times contribute significantly to recruitment. This is particularly true for years where the cold ridge persists into winter. Data on chokka squid paralarval distribution are scarce. Paralarval distribution and abundance, in relation to Agulhas Bank oceanography, was investigated using bongo caught paralarvae and corresponding oceanographic data. Individual-based models (IBMs) were used to predict the origin or spawning site of the wild caught paralarvae, with reference to inshore versus deep spawning. Although failing to predict realistic points of origin, this study provided evidence to support a number of scenarios previously assumed to influence chokka squid recruitment. First is the possible influence of coastal upwelling on the retention, and hence spatial distribution, of paralarvae on the inshore spawning grounds. The second factor thought to impact recruitment is the loss of paralarvae from the Agulhas Bank ecosystem. This study confirmed the removal of paralarvae from the Eastern Agulhas Bank due to Agulhas Current boundary phenomena and resultant offshelf leakage. In addition, data suggested that the formation of the cold ridge could enhance retention on the Central Agulhas Bank, and so prevent offshelf leakage from the Central and Western Agulhas Bank. A synthesis of the main conclusions is presented. Implications of the findings and directions for future research are discussed.
- Full Text:
- Date Issued: 2014
The water and nutrient potential of brewery effluent for hydroponic tomato production
- Authors: Power, Sean Duncan
- Date: 2014
- Subjects: Hydroponics , Tomatoes -- Breeding , Brewery waste , Water -- Purification , Algae culture , Algae -- Biotechnology , Nitric acid , Phosphoric acid
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5358 , http://hdl.handle.net/10962/d1011604 , Hydroponics , Tomatoes -- Breeding , Brewery waste , Water -- Purification , Algae culture , Algae -- Biotechnology , Nitric acid , Phosphoric acid
- Description: Brewery effluent that had undergone treatment in an anaerobic digester (AD) was used as an alternative water and nutrient source for hydroponic crop production. Brewery effluent was demonstrated to contain sufficient nutrients to support the growth, flowering and fruiting of Lycopersicum escolentum "Moneymaker" tomato crops. The adjustment of the effluent pH with phosphoric acid to between pH 6.0 and 6.5 increased the development of the crops by around 100% compared to crops grown in unaltered effluent. The pH adjusted effluent-grown plants grew to a mean height of 831.4 ± 21.1 mm and a dry biomass weight of 42.34 ± 2.76 g compared to the unaltered pH effluent plants which grew to a height of 410.6 ± 20.5 mm and a weight of 7.65 ± 0.68 g after 49 days. Effluent treatment in high-rate algal ponds (HRAP) was determined to have no positive effect on the nutritional potential of the effluent for Moneymaker production. The effluent-grown plants did not perform as well as plants grown in inorganic-fertilizer and municipal water. Plants grown in effluent grew taller but did not produce significantly more fruit when phosphoric acid (height: 1573.3 ± 50.4 mm, 19.4 ± 1.4 fruit per plant) was compared to nitric acid (height: 1254.1 ± 25.4 mm, 15.6 ± 1.5 fruit per plant) as the pH adjustment over 72 days. Direct and secondary plant stresses from effluent alkalinity, ammonium nutrition, nitrogen limitation, sodium concentrations and heat stress among other factors were probably confounding variables in these trials and require further investigation. Considering the raw effluent composition and manipulating the AD operation is a potential opportunity to improve overall AD performance, reduce chemical inputs in the effluent treatment process, reduce the final effluent alkalinity, and increase available nitrogen content in the final effluent. The anaerobic digester discharging >1000 m³ of nutrient enriched effluent every day is a resource with considerable potential. The benefits of developing this resource can contribute to cost-reduction at the brewery, more efficient water, nutrient and energy management at the brewery, and offer opportunities for job creation and potentially benefit local food security.
- Full Text:
- Date Issued: 2014
- Authors: Power, Sean Duncan
- Date: 2014
- Subjects: Hydroponics , Tomatoes -- Breeding , Brewery waste , Water -- Purification , Algae culture , Algae -- Biotechnology , Nitric acid , Phosphoric acid
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5358 , http://hdl.handle.net/10962/d1011604 , Hydroponics , Tomatoes -- Breeding , Brewery waste , Water -- Purification , Algae culture , Algae -- Biotechnology , Nitric acid , Phosphoric acid
- Description: Brewery effluent that had undergone treatment in an anaerobic digester (AD) was used as an alternative water and nutrient source for hydroponic crop production. Brewery effluent was demonstrated to contain sufficient nutrients to support the growth, flowering and fruiting of Lycopersicum escolentum "Moneymaker" tomato crops. The adjustment of the effluent pH with phosphoric acid to between pH 6.0 and 6.5 increased the development of the crops by around 100% compared to crops grown in unaltered effluent. The pH adjusted effluent-grown plants grew to a mean height of 831.4 ± 21.1 mm and a dry biomass weight of 42.34 ± 2.76 g compared to the unaltered pH effluent plants which grew to a height of 410.6 ± 20.5 mm and a weight of 7.65 ± 0.68 g after 49 days. Effluent treatment in high-rate algal ponds (HRAP) was determined to have no positive effect on the nutritional potential of the effluent for Moneymaker production. The effluent-grown plants did not perform as well as plants grown in inorganic-fertilizer and municipal water. Plants grown in effluent grew taller but did not produce significantly more fruit when phosphoric acid (height: 1573.3 ± 50.4 mm, 19.4 ± 1.4 fruit per plant) was compared to nitric acid (height: 1254.1 ± 25.4 mm, 15.6 ± 1.5 fruit per plant) as the pH adjustment over 72 days. Direct and secondary plant stresses from effluent alkalinity, ammonium nutrition, nitrogen limitation, sodium concentrations and heat stress among other factors were probably confounding variables in these trials and require further investigation. Considering the raw effluent composition and manipulating the AD operation is a potential opportunity to improve overall AD performance, reduce chemical inputs in the effluent treatment process, reduce the final effluent alkalinity, and increase available nitrogen content in the final effluent. The anaerobic digester discharging >1000 m³ of nutrient enriched effluent every day is a resource with considerable potential. The benefits of developing this resource can contribute to cost-reduction at the brewery, more efficient water, nutrient and energy management at the brewery, and offer opportunities for job creation and potentially benefit local food security.
- Full Text:
- Date Issued: 2014
Thermoluminescence characteristics of synthetic quartz
- Authors: Niyonzima, Pontien
- Date: 2014
- Subjects: Thermoluminescence , Quartz , Emission spectroscopy
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5538 , http://hdl.handle.net/10962/d1013190
- Description: Quartz is one of the most abundant natural minerals in the crust of the earth. Due to its dosimetric luminescence properties, it is employed in retrospective dosimetry, archaeological and geological dating. The intensity and the structure of the TL glow curves of quartz are strongly dependent upon the origin, impurity content, formation condition and pre-irradiation heat treatment. The aim of this project is to study the mechanisms of thermoluminescence (TL), Phototranssferred thermoluminescence (PTTL) and radioluminescence (RL) in synthetic quartz and to discuss the results in terms of physical characteristics of point defects involved. Thermoluminescence measurements were made on a sample of synthetic quartz in its as-received state (unannealed) synthetic quartz annealed at 500˚C for 10 minutes. The unannealed sample shows six TL glow peaks located at 94, 116, 176, 212, 280 and 348˚C at a heating rate of 5˚Cs⁻¹. The annealed sample shows seven TL peaks at 115, 148, 214, 246, 300, 348 and 412˚C at a heating rate of 5˚Cs⁻¹. The intensity of peak I, at 94 and 115˚C for the unannealed and annealed samples respectively, increases with irradiation. Peak I has an activation energy of approximately 0.90 eV and a frequency factor of the order of 10¹¹ s⁻¹. The order of kinetics is between 0.9 and 1.2. The unannealed synthetic quartz shows phototransferred thermoluminescence (PTTL) at the position of peak I after removal of the first three peaks followed by illumination. The PTTL intensities show peak shaped behaviour when plotted against illumination time. The PTTL showed a quadratic increase with dose. The material exhibits fading of PTTL intensity with delay time. Radioluminescence was measured on synthetic quartz unannealed and annealed annealed at 500, 600, 700, 800, 900 and 1000˚C for 10 to 60 min. The emission spectra of synthetic quartz show seven emission bands. The effect of irradiation on the RL spectra is to increase the intensity of all emission bands for samples annealed at temperatures less than or equal to 700˚C. The effect of annealing time is to increase the RL amplitude for the samples annealed at temperatures greater than 700˚C. The annealing temperature increases the RL amplitude of all emission bands of the spectrum for all samples.
- Full Text:
- Date Issued: 2014
- Authors: Niyonzima, Pontien
- Date: 2014
- Subjects: Thermoluminescence , Quartz , Emission spectroscopy
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5538 , http://hdl.handle.net/10962/d1013190
- Description: Quartz is one of the most abundant natural minerals in the crust of the earth. Due to its dosimetric luminescence properties, it is employed in retrospective dosimetry, archaeological and geological dating. The intensity and the structure of the TL glow curves of quartz are strongly dependent upon the origin, impurity content, formation condition and pre-irradiation heat treatment. The aim of this project is to study the mechanisms of thermoluminescence (TL), Phototranssferred thermoluminescence (PTTL) and radioluminescence (RL) in synthetic quartz and to discuss the results in terms of physical characteristics of point defects involved. Thermoluminescence measurements were made on a sample of synthetic quartz in its as-received state (unannealed) synthetic quartz annealed at 500˚C for 10 minutes. The unannealed sample shows six TL glow peaks located at 94, 116, 176, 212, 280 and 348˚C at a heating rate of 5˚Cs⁻¹. The annealed sample shows seven TL peaks at 115, 148, 214, 246, 300, 348 and 412˚C at a heating rate of 5˚Cs⁻¹. The intensity of peak I, at 94 and 115˚C for the unannealed and annealed samples respectively, increases with irradiation. Peak I has an activation energy of approximately 0.90 eV and a frequency factor of the order of 10¹¹ s⁻¹. The order of kinetics is between 0.9 and 1.2. The unannealed synthetic quartz shows phototransferred thermoluminescence (PTTL) at the position of peak I after removal of the first three peaks followed by illumination. The PTTL intensities show peak shaped behaviour when plotted against illumination time. The PTTL showed a quadratic increase with dose. The material exhibits fading of PTTL intensity with delay time. Radioluminescence was measured on synthetic quartz unannealed and annealed annealed at 500, 600, 700, 800, 900 and 1000˚C for 10 to 60 min. The emission spectra of synthetic quartz show seven emission bands. The effect of irradiation on the RL spectra is to increase the intensity of all emission bands for samples annealed at temperatures less than or equal to 700˚C. The effect of annealing time is to increase the RL amplitude for the samples annealed at temperatures greater than 700˚C. The annealing temperature increases the RL amplitude of all emission bands of the spectrum for all samples.
- Full Text:
- Date Issued: 2014
Thermoluminescence of natural quartz
- Authors: Lontsi Sob, Aaron Joel
- Date: 2014
- Subjects: Thermoluminescence , Quartz , Thermoluminescence dosimetry
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5543 , http://hdl.handle.net/10962/d1013358
- Description: The kinetic and dosimetric features of the main thermoluminescence peak of quartz have been investigated in unannealed as well in quartz annealed at 500˚C for 10 minutes. The main peak is found at 92 and 86˚C respectively for aliquots of unannealed and annealed samples irradiated to 10 Gy and heated at 5.0˚C/s. For each sample, the intensity of the main peak is enhanced with repetitive measurement whereas its maximum temperature is unaffected. The peak position of the main peak in each sample is independent of the irradiation dose and this, together with its fading characteristics are consistent with first-order kinetics. For low doses, typically between 2 and 10 Gy, the dose response of the main peak in each sample is linear. In the intermediate dose range from 10 to 60 Gy, the growth of the main peak in each sample is sub-linear and for greater doses, in the range from 60 Gy to 151 Gy, it is linear again. The half-life of the main peak of the unannealed sample is about 1.3 h whereas that of the annealed sample is about 1.2 h. The main peak in each sample can be approximated to a first-order glow peak. As the heating rate increases, the intensity of the main peak in each sample decreases. This is evidence of thermal quenching. The main peak in each sample is the only peak regenerated by phototransfer. The resulting phototransferred peak occurs at the same temperature as the original peak and has similar kinetic and dosimetric features. For a preheat temperature of 120˚C, the intensity of the phototransferred peak in each sample increases with illumination time up to a maximum and decreases afterwards. At longer illumination times (such as 30 min up to 1 h), no further decrease in the intensity of the phototransferred peak is observed. The traps associated with the 325˚C peak are the main source of the electrons responsible for the regenerated peak. Radioluminescence emission spectra were also measured for quartz annealed at various temperatures. Emission bands in quartz are affected by annealing and irradiation. A strong enhancement of the 3.4 eV (~366 nm) emission band is observed in quartz annealed at 500˚C. A new emission band which grows with annealing up to 1000˚C is observed at 3.7 eV (~330 nm) for quartz annealed at 600˚C. An attempt has been made to correlate the changes in radioluminescence emission spectra due to annealing with the influence of annealing on luminescence lifetimes in quartz.
- Full Text:
- Date Issued: 2014
- Authors: Lontsi Sob, Aaron Joel
- Date: 2014
- Subjects: Thermoluminescence , Quartz , Thermoluminescence dosimetry
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5543 , http://hdl.handle.net/10962/d1013358
- Description: The kinetic and dosimetric features of the main thermoluminescence peak of quartz have been investigated in unannealed as well in quartz annealed at 500˚C for 10 minutes. The main peak is found at 92 and 86˚C respectively for aliquots of unannealed and annealed samples irradiated to 10 Gy and heated at 5.0˚C/s. For each sample, the intensity of the main peak is enhanced with repetitive measurement whereas its maximum temperature is unaffected. The peak position of the main peak in each sample is independent of the irradiation dose and this, together with its fading characteristics are consistent with first-order kinetics. For low doses, typically between 2 and 10 Gy, the dose response of the main peak in each sample is linear. In the intermediate dose range from 10 to 60 Gy, the growth of the main peak in each sample is sub-linear and for greater doses, in the range from 60 Gy to 151 Gy, it is linear again. The half-life of the main peak of the unannealed sample is about 1.3 h whereas that of the annealed sample is about 1.2 h. The main peak in each sample can be approximated to a first-order glow peak. As the heating rate increases, the intensity of the main peak in each sample decreases. This is evidence of thermal quenching. The main peak in each sample is the only peak regenerated by phototransfer. The resulting phototransferred peak occurs at the same temperature as the original peak and has similar kinetic and dosimetric features. For a preheat temperature of 120˚C, the intensity of the phototransferred peak in each sample increases with illumination time up to a maximum and decreases afterwards. At longer illumination times (such as 30 min up to 1 h), no further decrease in the intensity of the phototransferred peak is observed. The traps associated with the 325˚C peak are the main source of the electrons responsible for the regenerated peak. Radioluminescence emission spectra were also measured for quartz annealed at various temperatures. Emission bands in quartz are affected by annealing and irradiation. A strong enhancement of the 3.4 eV (~366 nm) emission band is observed in quartz annealed at 500˚C. A new emission band which grows with annealing up to 1000˚C is observed at 3.7 eV (~330 nm) for quartz annealed at 600˚C. An attempt has been made to correlate the changes in radioluminescence emission spectra due to annealing with the influence of annealing on luminescence lifetimes in quartz.
- Full Text:
- Date Issued: 2014
Thermoluminescence of secondary glow peaks in carbon-doped aluminium oxide
- Authors: Seneza, Cleophace
- Date: 2014
- Subjects: Thermoluminescence , Aluminum oxide , Thermoluminescence dosimetry
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5537 , http://hdl.handle.net/10962/d1013053
- Description: Carbon-doped aluminium oxide, α-Al₂O₃ : C, is a highly sensitive luminescence dosimeter. The high sensitivity of α-Al₂O₃ : C has been attributed to large concentrations of oxygen vacancies, F and F⁺ centres, induced in the material during its preparation. The material is prepared in a highly reducing atmosphere in the presence of carbon. In the luminescence process, electrons are trapped in F-centre defects as a result of irradiation of the material. Thermal or optical release of trapped electrons leads to emission of light, thermoluminescence (TL) or optically stimulated light (OSL) respectively. The thermoluminescence technique is used to study point defects involved in luminescence of α-Al₂O₃ : C. A glow curve of α-Al₂O₃ : C, generally, shows three peaks; the main dosimetric peak of high intensity (peak II) and two other peaks of lower intensity called secondary glow peaks (peaks I and III). The overall aim of our work was to study the TL mechanisms responsible for secondary glow peaks in α-Al₂O₃ : C. The dynamics of charge movement between centres during the TL process was studied. The phototransferred thermoluminescence (PTTL) from secondary glow peaks was also studied. The kinetic analysis of TL from secondary peaks has shown that the activation energy of peak I is 0.7 eV and that of peak III, 1.2 eV. The frequency factor, the frequency at which an electron attempts to escape a trap, was found near the range of the Debye vibration frequency. Values of the activation energy are consistent within a variety of methods used. The two peaks follow first order kinetics as confirmed by the TM-Tstop method. A linear dependence of TL from peak I on dose is observed at various doses from 0.5 to 2.5 Gy. The peak position for peak I was also independent on dose, further confirmation that peak I is of first order kinetics. Peak I suffers from thermal fading with storage with a half-life of about 120 s. The dependence of TL intensity for peak I increased as a function of heating rate from 0.2 to 6ºCs⁻¹. In contrast to the TL intensity for peak I, the intensity of TL for peak III decreases with an increase of heating rate from 0.2 to 6ºCs⁻¹. This is evidence of thermal quenching for peak III. Parameters W = 1.48 ± 0:10 eV and C = 4 x 10¹³ of thermal quenching were calculated from peak III intensities at different heating rates. Thermal cleaning of peak III and the glow curve deconvolution methods confirmed that the main peak is actually overlapped by a small peak (labeled peak IIA). The kinetic analysis of peak IIA showed that it is of first order kinetics and that its activation energy is 1:0 eV. In addition, the peak IIA is affected by thermal quenching. Another secondary peak appears at 422ºC (peak IV). However, the kinetic analysis of TL from peak IV was not studied because its intensity is not well defined. A heating rate of 0.4ºCs⁻¹ was used after a dose of 3 Gy in kinetic analysis of peaks IIA and III. The study of the PTTL showed that peaks I and II were regenerated under PTTL but peak III was not. Various effects of the PTTL for peaks I and II for different preheating temperatures in different samples were observed. The effect of annealing at 900ºC for 15 minutes between measurements following each illumination time was studied. The effect of dose on secondary peaks was also studied in this work. The kinetic analysis of the PTTL intensity for peak I showed that its activation energy is 0.7 eV, consistent with the activation energy of the normal TL for peak I. The PTTL intensity from peak I fades rapidly with storage compared with the thermal fading from peak I of the normal TL. The PTTL intensity for peak I decreases as a function of heating rate. This decrease was attributed to thermal quenching. Thermal quenching was not observed in the case of the normal TL intensity. The cause of this contrast requires further study.
- Full Text:
- Date Issued: 2014
- Authors: Seneza, Cleophace
- Date: 2014
- Subjects: Thermoluminescence , Aluminum oxide , Thermoluminescence dosimetry
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5537 , http://hdl.handle.net/10962/d1013053
- Description: Carbon-doped aluminium oxide, α-Al₂O₃ : C, is a highly sensitive luminescence dosimeter. The high sensitivity of α-Al₂O₃ : C has been attributed to large concentrations of oxygen vacancies, F and F⁺ centres, induced in the material during its preparation. The material is prepared in a highly reducing atmosphere in the presence of carbon. In the luminescence process, electrons are trapped in F-centre defects as a result of irradiation of the material. Thermal or optical release of trapped electrons leads to emission of light, thermoluminescence (TL) or optically stimulated light (OSL) respectively. The thermoluminescence technique is used to study point defects involved in luminescence of α-Al₂O₃ : C. A glow curve of α-Al₂O₃ : C, generally, shows three peaks; the main dosimetric peak of high intensity (peak II) and two other peaks of lower intensity called secondary glow peaks (peaks I and III). The overall aim of our work was to study the TL mechanisms responsible for secondary glow peaks in α-Al₂O₃ : C. The dynamics of charge movement between centres during the TL process was studied. The phototransferred thermoluminescence (PTTL) from secondary glow peaks was also studied. The kinetic analysis of TL from secondary peaks has shown that the activation energy of peak I is 0.7 eV and that of peak III, 1.2 eV. The frequency factor, the frequency at which an electron attempts to escape a trap, was found near the range of the Debye vibration frequency. Values of the activation energy are consistent within a variety of methods used. The two peaks follow first order kinetics as confirmed by the TM-Tstop method. A linear dependence of TL from peak I on dose is observed at various doses from 0.5 to 2.5 Gy. The peak position for peak I was also independent on dose, further confirmation that peak I is of first order kinetics. Peak I suffers from thermal fading with storage with a half-life of about 120 s. The dependence of TL intensity for peak I increased as a function of heating rate from 0.2 to 6ºCs⁻¹. In contrast to the TL intensity for peak I, the intensity of TL for peak III decreases with an increase of heating rate from 0.2 to 6ºCs⁻¹. This is evidence of thermal quenching for peak III. Parameters W = 1.48 ± 0:10 eV and C = 4 x 10¹³ of thermal quenching were calculated from peak III intensities at different heating rates. Thermal cleaning of peak III and the glow curve deconvolution methods confirmed that the main peak is actually overlapped by a small peak (labeled peak IIA). The kinetic analysis of peak IIA showed that it is of first order kinetics and that its activation energy is 1:0 eV. In addition, the peak IIA is affected by thermal quenching. Another secondary peak appears at 422ºC (peak IV). However, the kinetic analysis of TL from peak IV was not studied because its intensity is not well defined. A heating rate of 0.4ºCs⁻¹ was used after a dose of 3 Gy in kinetic analysis of peaks IIA and III. The study of the PTTL showed that peaks I and II were regenerated under PTTL but peak III was not. Various effects of the PTTL for peaks I and II for different preheating temperatures in different samples were observed. The effect of annealing at 900ºC for 15 minutes between measurements following each illumination time was studied. The effect of dose on secondary peaks was also studied in this work. The kinetic analysis of the PTTL intensity for peak I showed that its activation energy is 0.7 eV, consistent with the activation energy of the normal TL for peak I. The PTTL intensity from peak I fades rapidly with storage compared with the thermal fading from peak I of the normal TL. The PTTL intensity for peak I decreases as a function of heating rate. This decrease was attributed to thermal quenching. Thermal quenching was not observed in the case of the normal TL intensity. The cause of this contrast requires further study.
- Full Text:
- Date Issued: 2014
Thinking academic freedom
- Authors: Lange, Lis
- Date: 2014
- Subjects: Academic Freedom -- South Africa Universities and colleges -- South Africa Equality Liberty Education and state -- South Africa Education, Higher -- South Africa
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/784 , vital:19990
- Description: I have titled this lecture Thinking Academic Freedom, because I would like to make thinking in the Arendtian sense the axis along which to organise this exposition. It was interesting for me that when I sent the title of the lecture I was asked whether I meant thinking or rethinking. It is true that we tend to rethink, revisit and review in the titles of our lectures and papers. This usually means that the accent is not so much on the act of thinking but on the object we are trying to examine. For this occasion, I would like to make the act of thinking itself as important an aspect of the lecture as the issue of academic freedom itself. What interests me is to explore the nature of our work as academics and how this relates to the notion of academic freedom. So, this is my proposed itinerary: I will first stop to flag some of the issues we all know about, current debates on academic freedom which inevitably constitute one layer of the background for these reflections; then I would like to explore with the lens of Hannah Arendt's political thinking the meaning of freedom and thinking in relation to the life of academics. I will then complicate matters further by jumping from Arendt to Pierre Bourdieu's Homo Academicus, after which I hope to land in the not too comfortable terrain of a call to action.
- Full Text:
- Date Issued: 2014
- Authors: Lange, Lis
- Date: 2014
- Subjects: Academic Freedom -- South Africa Universities and colleges -- South Africa Equality Liberty Education and state -- South Africa Education, Higher -- South Africa
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/784 , vital:19990
- Description: I have titled this lecture Thinking Academic Freedom, because I would like to make thinking in the Arendtian sense the axis along which to organise this exposition. It was interesting for me that when I sent the title of the lecture I was asked whether I meant thinking or rethinking. It is true that we tend to rethink, revisit and review in the titles of our lectures and papers. This usually means that the accent is not so much on the act of thinking but on the object we are trying to examine. For this occasion, I would like to make the act of thinking itself as important an aspect of the lecture as the issue of academic freedom itself. What interests me is to explore the nature of our work as academics and how this relates to the notion of academic freedom. So, this is my proposed itinerary: I will first stop to flag some of the issues we all know about, current debates on academic freedom which inevitably constitute one layer of the background for these reflections; then I would like to explore with the lens of Hannah Arendt's political thinking the meaning of freedom and thinking in relation to the life of academics. I will then complicate matters further by jumping from Arendt to Pierre Bourdieu's Homo Academicus, after which I hope to land in the not too comfortable terrain of a call to action.
- Full Text:
- Date Issued: 2014
Tourism and development : a case study of Mdumbi Backpackers and Transcape non-profit organisation
- Authors: Hitchcock, Kelly Alexandra
- Date: 2014
- Subjects: Mdumbi Backpackers -- South Africa -- Eastern Cape , Tourism -- South Africa -- Eastern Cape , Tourism -- South Africa -- Eastern Cape -- Planning , Backpacking -- South Africa -- Eastern Cape -- Case studies , Black people -- Employment -- South Africa -- Eastern Cape , Sustainable development -- South Africa -- Eastern Cape , Economic development -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:3377 , http://hdl.handle.net/10962/d1013143
- Description: The former Transkei region of the Eastern Cape of South Africa, in common with many of the other former Bantustans, is currently facing a developmental backlog. It is one of the poorest regions of the country and is a direct product of South Africa’s history of colonisation and geopolitical nature of apartheid in which people were forcibly located onto former tribal lands, called Bantustans. Tourism is one of the few business opportunities providing employment along the former Transkei coast. The tourism industry has been identified by many worldwide as a key strategy that can lead to economic upliftment, community development and poverty relief in the developing world. The predicament however, lies in the challenge of accepting or managing the negative consequences of tourism for the potential long term benefits offered by tourism-led development. Tourism development theory reflects development theory from traditional, top-down economic-growth based models to a more wide based approach with an emphasis on bottom-up planning, meeting of basic human need and a focus on sustainable development. Consequentially new and alternative forms of tourism have emerged and can be viewed as a response to some of the negative consequences of the mass tourism-led model of economic development. Backpacker tourism is one niche of the tourism market that is providing positive local socioeconomic benefits. This thesis is presented as a case study of Mdumbi Backpackers on the former Transkei coast. Mdumbi Backpackers is a unique example of a model of tourism that is providing meaningful benefits to the people who live in this community. By going one step further with the creation of the non-profit organisation Transcape, their involvement in the community has grown significantly, encouraging positive and sustainable development in the areas of social development, education and health. Mdumbi Backpackers goes beyond the notions of locally owned and sustainable approaches and actively encourages development by setting up community organisations and initiatives in a sustainable and equitable way. This approach to tourism-led development is well suited for the needs and objectives of the community as well preserving the natural environment. This thesis presents an exemplary example from which lessons can be learned and applied to developing tourism in a sustainable and equitable way in other rural communities.
- Full Text:
- Date Issued: 2014
- Authors: Hitchcock, Kelly Alexandra
- Date: 2014
- Subjects: Mdumbi Backpackers -- South Africa -- Eastern Cape , Tourism -- South Africa -- Eastern Cape , Tourism -- South Africa -- Eastern Cape -- Planning , Backpacking -- South Africa -- Eastern Cape -- Case studies , Black people -- Employment -- South Africa -- Eastern Cape , Sustainable development -- South Africa -- Eastern Cape , Economic development -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:3377 , http://hdl.handle.net/10962/d1013143
- Description: The former Transkei region of the Eastern Cape of South Africa, in common with many of the other former Bantustans, is currently facing a developmental backlog. It is one of the poorest regions of the country and is a direct product of South Africa’s history of colonisation and geopolitical nature of apartheid in which people were forcibly located onto former tribal lands, called Bantustans. Tourism is one of the few business opportunities providing employment along the former Transkei coast. The tourism industry has been identified by many worldwide as a key strategy that can lead to economic upliftment, community development and poverty relief in the developing world. The predicament however, lies in the challenge of accepting or managing the negative consequences of tourism for the potential long term benefits offered by tourism-led development. Tourism development theory reflects development theory from traditional, top-down economic-growth based models to a more wide based approach with an emphasis on bottom-up planning, meeting of basic human need and a focus on sustainable development. Consequentially new and alternative forms of tourism have emerged and can be viewed as a response to some of the negative consequences of the mass tourism-led model of economic development. Backpacker tourism is one niche of the tourism market that is providing positive local socioeconomic benefits. This thesis is presented as a case study of Mdumbi Backpackers on the former Transkei coast. Mdumbi Backpackers is a unique example of a model of tourism that is providing meaningful benefits to the people who live in this community. By going one step further with the creation of the non-profit organisation Transcape, their involvement in the community has grown significantly, encouraging positive and sustainable development in the areas of social development, education and health. Mdumbi Backpackers goes beyond the notions of locally owned and sustainable approaches and actively encourages development by setting up community organisations and initiatives in a sustainable and equitable way. This approach to tourism-led development is well suited for the needs and objectives of the community as well preserving the natural environment. This thesis presents an exemplary example from which lessons can be learned and applied to developing tourism in a sustainable and equitable way in other rural communities.
- Full Text:
- Date Issued: 2014
Toward a culture of engagement: leveraging the enterprise social network
- Authors: Alistoun, Garth
- Date: 2014
- Subjects: Communication in organizations -- South Africa Business communication -- South Africa Social media -- South Africa -- Case studies Leadership -- South Africa -- Case studies Human capital -- Management Personnel management Organizational effectiveness
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1154 , http://hdl.handle.net/10962/d1010869
- Description: This research aims to provide a theory of enterprise social networking that generates and/or sustains a culture of employee engagement within a chosen South African private sector company. Based on an extensive review of interesting literature and the application of a grounded theory process in a chosen case, this research work provides a theory of enterprise social networking sustaining and growing employee engagement together with an explanatory theoretical framework that makes the theory more practical. Employee engagement is defined as “the harnessing of organisation member’s selves to their work roles; in engagement people employ and express themselves physically, cognitively, and emotionally during role performances.” This research regards employee engagement as a three part concept composed of a trait (personality/cognitive) aspect, a state (emotional) aspect, and a behavioural aspect. Research has shown that employee engagement has an unequivocal positive impact on business outcomes, such as profitability, business performance, employee retention and productivity. Employee engagement can be regarded as a culture if it is abundant within the organization’s employee population. Gatenby et al. (2009) propose that employee engagement is fostered by creating the desire and opportunity for employees to connect with colleagues, managers and the wider organisation. This standpoint is supported by Kular et al. (2008) who state that the “key drivers of employee engagement identified include communication, opportunities for employees to feed their views upward and thinking that their managers are committed to the organisation.” Further indicators of employee engagement include strong leadership (particularly in the form of servant leadership), accountability, a positive and open organisational culture, autonomy, and opportunities for development. One of the key facets of employee engagement is connection. A complementary definition of social media, an umbrella under which enterprise social networks fall, is that “(it) is more of a relationship channel, a connection channel. Each and every tweet, update, video, post, is a connection point to another human being. And it’s the other human being who will determine your worth to them.” Social media provides participants with access to a larger pool of resources and relationships than they would normally have access to. This enlarged relationship/resource pool is a result of expanding human and social capital enabled through social media tools. In order to produce a theory of enterprise social networking sustaining and growing a culture of employee engagement a rigorous grounded theory methodology coupled with a case study methodology was applied. The case study methodology was used to identify a suitable research site and interesting participants within the site while the grounded theory process was used to produce both qualitative and quantitative data sets in a suitability rigorous fashion. The corroborative data was then used to discover and define the emergent theory.
- Full Text:
- Date Issued: 2014
- Authors: Alistoun, Garth
- Date: 2014
- Subjects: Communication in organizations -- South Africa Business communication -- South Africa Social media -- South Africa -- Case studies Leadership -- South Africa -- Case studies Human capital -- Management Personnel management Organizational effectiveness
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1154 , http://hdl.handle.net/10962/d1010869
- Description: This research aims to provide a theory of enterprise social networking that generates and/or sustains a culture of employee engagement within a chosen South African private sector company. Based on an extensive review of interesting literature and the application of a grounded theory process in a chosen case, this research work provides a theory of enterprise social networking sustaining and growing employee engagement together with an explanatory theoretical framework that makes the theory more practical. Employee engagement is defined as “the harnessing of organisation member’s selves to their work roles; in engagement people employ and express themselves physically, cognitively, and emotionally during role performances.” This research regards employee engagement as a three part concept composed of a trait (personality/cognitive) aspect, a state (emotional) aspect, and a behavioural aspect. Research has shown that employee engagement has an unequivocal positive impact on business outcomes, such as profitability, business performance, employee retention and productivity. Employee engagement can be regarded as a culture if it is abundant within the organization’s employee population. Gatenby et al. (2009) propose that employee engagement is fostered by creating the desire and opportunity for employees to connect with colleagues, managers and the wider organisation. This standpoint is supported by Kular et al. (2008) who state that the “key drivers of employee engagement identified include communication, opportunities for employees to feed their views upward and thinking that their managers are committed to the organisation.” Further indicators of employee engagement include strong leadership (particularly in the form of servant leadership), accountability, a positive and open organisational culture, autonomy, and opportunities for development. One of the key facets of employee engagement is connection. A complementary definition of social media, an umbrella under which enterprise social networks fall, is that “(it) is more of a relationship channel, a connection channel. Each and every tweet, update, video, post, is a connection point to another human being. And it’s the other human being who will determine your worth to them.” Social media provides participants with access to a larger pool of resources and relationships than they would normally have access to. This enlarged relationship/resource pool is a result of expanding human and social capital enabled through social media tools. In order to produce a theory of enterprise social networking sustaining and growing a culture of employee engagement a rigorous grounded theory methodology coupled with a case study methodology was applied. The case study methodology was used to identify a suitable research site and interesting participants within the site while the grounded theory process was used to produce both qualitative and quantitative data sets in a suitability rigorous fashion. The corroborative data was then used to discover and define the emergent theory.
- Full Text:
- Date Issued: 2014
Towards sustainable municipalities : an evaluation of sustainability integration in Elundini Local Municipality strategy
- Authors: Sokutu, Nonkuselo
- Date: 2014
- Subjects: Municipal government -- South Africa -- Eastern Cape , Strategic planning -- South Africa -- Eastern Cape , Sustainability -- South Africa -- Eastern Cape , Sustainable development -- South Africa -- Eastern Cape , Sustainable development -- Social aspects -- South Africa -- Eastern Cape , Sustainable development -- Environmental aspects -- South Africa -- Eastern Cape , Sustainable development -- Economic aspects -- South Africa -- Eastern Cape , Environmental impact analysis -- South Africa -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:830 , http://hdl.handle.net/10962/d1013018
- Description: This research study evaluated and assessed the extent to which strategic management processes integrated economic, environmental and social sustainability elements in the fiveyear strategy (2012) of Elundini Local Municipality (ELM). The study focused on three areas of strategic management, that is, environmental analysis, strategic direction and strategy formulation. The study also looked at possible reasons for sustainability integration in ELM strategy or lack thereof and also recommended possible solutions. The literature reviewed revealed that there was adequate basis for municipalities to integrate sustainable development in their strategies even though sustainability was noted as an evolving, complex and changing phenomenon. Local Agenda 21 principles, national legislative & policy framework, regulations and other relevant guidelines were found to be adequate for municipalities to develop credible sustainability strategies. The objectives of the study were achieved by data collected through the review of existing literature; the review of ELM Five Year Strategy (2012-2017); and SIAT-based questionnaires that were filled in by ELM employees. The results of the study showed that economic and social sustainability activities were identified most in the ELM strategy compared to environmental sustainability. The study then mainly recommended the review of the current strategy in order to improve all areas of strategy formulation; introduction of Economic, Social and Environmental sustainability – Strengths, Weaknesses, Opportunities and Threats (ESEs-SWOT) for internal analysis as an improvement of SWOT analysis; introduction of Sustainability Integration and Strategic Management Framework (SISMF) as an improvement to existing framework.
- Full Text:
- Date Issued: 2014
- Authors: Sokutu, Nonkuselo
- Date: 2014
- Subjects: Municipal government -- South Africa -- Eastern Cape , Strategic planning -- South Africa -- Eastern Cape , Sustainability -- South Africa -- Eastern Cape , Sustainable development -- South Africa -- Eastern Cape , Sustainable development -- Social aspects -- South Africa -- Eastern Cape , Sustainable development -- Environmental aspects -- South Africa -- Eastern Cape , Sustainable development -- Economic aspects -- South Africa -- Eastern Cape , Environmental impact analysis -- South Africa -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:830 , http://hdl.handle.net/10962/d1013018
- Description: This research study evaluated and assessed the extent to which strategic management processes integrated economic, environmental and social sustainability elements in the fiveyear strategy (2012) of Elundini Local Municipality (ELM). The study focused on three areas of strategic management, that is, environmental analysis, strategic direction and strategy formulation. The study also looked at possible reasons for sustainability integration in ELM strategy or lack thereof and also recommended possible solutions. The literature reviewed revealed that there was adequate basis for municipalities to integrate sustainable development in their strategies even though sustainability was noted as an evolving, complex and changing phenomenon. Local Agenda 21 principles, national legislative & policy framework, regulations and other relevant guidelines were found to be adequate for municipalities to develop credible sustainability strategies. The objectives of the study were achieved by data collected through the review of existing literature; the review of ELM Five Year Strategy (2012-2017); and SIAT-based questionnaires that were filled in by ELM employees. The results of the study showed that economic and social sustainability activities were identified most in the ELM strategy compared to environmental sustainability. The study then mainly recommended the review of the current strategy in order to improve all areas of strategy formulation; introduction of Economic, Social and Environmental sustainability – Strengths, Weaknesses, Opportunities and Threats (ESEs-SWOT) for internal analysis as an improvement of SWOT analysis; introduction of Sustainability Integration and Strategic Management Framework (SISMF) as an improvement to existing framework.
- Full Text:
- Date Issued: 2014
Towards the development of a larval feeding strategy for the white-margined sole (Dagetichthys marginatus)
- Authors: Thompson, Ernst Frederick
- Date: 2014
- Subjects: Flatfishes -- South Africa , Soleidae -- South Africa , Soleidae -- Larvae , Soleidae -- Larvae -- Feeding and feeds , Soleidae -- Larvae -- Physiology , Artemia
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5364 , http://hdl.handle.net/10962/d1012982
- Description: The major bottleneck during the domestication of the white-margined sole Dagetichthys marginatus in South Africa has been low larval survival. The cause of this is not clear but considering current literature on flatfish culture and more specifically soleid culture, nutritional deficiencies are hypothesized to be the main possible cause. Following the importance of nutrition, the first aim of the research was to use an ontogenetic developmental approach to develop a species specific larval feeding strategy. Ontogenetic development of D. marginatus showed that weaning will take place at much later ages than other soleids currently being farmed. This makes the partial replacement of Artemia with a suitable inert diet in co-feeding strategies very important to cut the cost associated of live food production. This leads on to the second aim, in which an 'in vitro' approach was used to model the digestibility of Artemia, which could ultimately contribute towards designing inert feeds with similar digestibility characteristics to Artemia in the future. Obtaining nutrients from food is closely linked to the functional status of the digestive tract, the support organs and the external morphological characteristics required for the ingestion of live or inert feeds. Considering both morphological and physiological ontogenetic development, it is clear that D. marginatus follow a similar pattern to other soleids. Larvae can successfully feed on Artemia as early as 3 days after hatching but exhibit a slow metamorphosis into the juvenile stage when compared to other soleids. The absence of any detectable acidic protease activity during the first 45 days of development and the importance of exogenous enzymes from Artemia all points to limited capacity to digest artificial diets. Prior to modelling the 'in vitro' digestion of Artemia, digestive enzyme activity at different pH's were modelled using functional forms from the normal distributive category of functions. , As there is no substantiated information for the general effects of pH on enzyme activity in the literature for finfish larvae, three species occurring in the same bio-geographical region of Dagetichthys marginatus, namely Sarpa salpa, Diplodus sargus capensis and Argyrosomus japonicus were used to investigate this effect. The fitted parameters, namely the optimal pH and sigma (the slope around the optimal pH) showed two interesting results. When using a negative log likelihood ratio test to test for differences between species for a particular enzyme, the optimal pH for alkaline proteases (7.67), lipase (8.03), amylase (7.69) and phosphatase (9.84) activity was the same for all three species. Furthermore, the study illustrated the potential to detect dietary shifts during ontogenetic development based on changes in enzyme activity around the optimal pH using the sigma parameter. Sarpa salpa showed increased amylase activity and a decrease in protease activity around the optimal pH with increased size, corresponding to a change in diet from zooplankton to algae. The 'in vitro' modelling approach taken in this study was based on known enzyme interactions and dynamics which makes the results very interpretable. from Artemia is achieved based on gut evacuation time and enzyme levels. This 'in vitro' study furthermore clearly indicates the importance of exogenous enzymes from Artemia, contributing as much as 54 percent to protein digestion and 64 – 72 percent to carbohydrate digestion. This was however, only an initial investigation, and further expansion of the model is required to achieve a complete understanding of Artemia digestion and ultimately partial replacement with artificial diets. A feeding strategy for D. marginatus should therefore follow those of other farmed soleids, although there will be a general delay in implementation due to slower development. Problems can thus be solved and improvements made by transferring technology from other soleids to D. marginatus.
- Full Text:
- Date Issued: 2014
- Authors: Thompson, Ernst Frederick
- Date: 2014
- Subjects: Flatfishes -- South Africa , Soleidae -- South Africa , Soleidae -- Larvae , Soleidae -- Larvae -- Feeding and feeds , Soleidae -- Larvae -- Physiology , Artemia
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5364 , http://hdl.handle.net/10962/d1012982
- Description: The major bottleneck during the domestication of the white-margined sole Dagetichthys marginatus in South Africa has been low larval survival. The cause of this is not clear but considering current literature on flatfish culture and more specifically soleid culture, nutritional deficiencies are hypothesized to be the main possible cause. Following the importance of nutrition, the first aim of the research was to use an ontogenetic developmental approach to develop a species specific larval feeding strategy. Ontogenetic development of D. marginatus showed that weaning will take place at much later ages than other soleids currently being farmed. This makes the partial replacement of Artemia with a suitable inert diet in co-feeding strategies very important to cut the cost associated of live food production. This leads on to the second aim, in which an 'in vitro' approach was used to model the digestibility of Artemia, which could ultimately contribute towards designing inert feeds with similar digestibility characteristics to Artemia in the future. Obtaining nutrients from food is closely linked to the functional status of the digestive tract, the support organs and the external morphological characteristics required for the ingestion of live or inert feeds. Considering both morphological and physiological ontogenetic development, it is clear that D. marginatus follow a similar pattern to other soleids. Larvae can successfully feed on Artemia as early as 3 days after hatching but exhibit a slow metamorphosis into the juvenile stage when compared to other soleids. The absence of any detectable acidic protease activity during the first 45 days of development and the importance of exogenous enzymes from Artemia all points to limited capacity to digest artificial diets. Prior to modelling the 'in vitro' digestion of Artemia, digestive enzyme activity at different pH's were modelled using functional forms from the normal distributive category of functions. , As there is no substantiated information for the general effects of pH on enzyme activity in the literature for finfish larvae, three species occurring in the same bio-geographical region of Dagetichthys marginatus, namely Sarpa salpa, Diplodus sargus capensis and Argyrosomus japonicus were used to investigate this effect. The fitted parameters, namely the optimal pH and sigma (the slope around the optimal pH) showed two interesting results. When using a negative log likelihood ratio test to test for differences between species for a particular enzyme, the optimal pH for alkaline proteases (7.67), lipase (8.03), amylase (7.69) and phosphatase (9.84) activity was the same for all three species. Furthermore, the study illustrated the potential to detect dietary shifts during ontogenetic development based on changes in enzyme activity around the optimal pH using the sigma parameter. Sarpa salpa showed increased amylase activity and a decrease in protease activity around the optimal pH with increased size, corresponding to a change in diet from zooplankton to algae. The 'in vitro' modelling approach taken in this study was based on known enzyme interactions and dynamics which makes the results very interpretable. from Artemia is achieved based on gut evacuation time and enzyme levels. This 'in vitro' study furthermore clearly indicates the importance of exogenous enzymes from Artemia, contributing as much as 54 percent to protein digestion and 64 – 72 percent to carbohydrate digestion. This was however, only an initial investigation, and further expansion of the model is required to achieve a complete understanding of Artemia digestion and ultimately partial replacement with artificial diets. A feeding strategy for D. marginatus should therefore follow those of other farmed soleids, although there will be a general delay in implementation due to slower development. Problems can thus be solved and improvements made by transferring technology from other soleids to D. marginatus.
- Full Text:
- Date Issued: 2014
Towards the feasibility of a landowner enterprise in the western Baviaanskloof : an external stakeholder analysis
- Authors: Wiles, Kira Leigh Deborah
- Date: 2014
- Subjects: Landowners -- South Africa -- Eastern Cape , Natural resources -- Co-management -- South Africa -- Eastern Cape , Land use -- Environmental aspects -- South Africa -- Eastern Cape , Land use -- Economic aspects -- South Africa -- Eastern Cape , Partnership -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1198 , http://hdl.handle.net/10962/d1012075 , Landowners -- South Africa -- Eastern Cape , Natural resources -- Co-management -- South Africa -- Eastern Cape , Land use -- Environmental aspects -- South Africa -- Eastern Cape , Land use -- Economic aspects -- South Africa -- Eastern Cape , Partnership -- South Africa -- Eastern Cape
- Description: In May 2012, a meeting was held between various stakeholder representatives of the Western Baviaanskloof to discuss the concept of a proposed landowner-enterprise. This concept was put forward in response to a need for collaboration in the midst of economic, environmental and social issues at play in the Baviaanskloof. Owing to the conservation value and rapidly decreasing economic output of the land, a radical shift to sustainable land-use practices was called for by various stakeholders. Suggested as a vehicle to generate income for the local landowners through alternative sustainable land-uses, the proposed enterprise may aid in addressing this shift by use of a bottom-up approach. During the stakeholder meeting, it was requested by the representative landowners that a feasibility assessment be conducted on the concept of the proposed enterprise prior to establishment. As an integral part of this assessment, the researcher took on the task of investigating stakeholder reception to the enterprise by means of a stakeholder analysis. It was decided to limit this to three markets: water, carbon and tourism. The purpose of this research study is twofold, namely to: investigate stakeholder influence and their reception of the proposed enterprise using a stakeholder analysis; and also to identify and advise on the opportunities and constraints relating to stakeholders, thus contributing to determining the feasibility of the proposed enterprise. In achieving the purpose of this study, a systematic stakeholder analysis framework was constructed, based on existing theory. This was necessary because, although stakeholder analysis is commonly practiced, no study was found to provide a theoretically based framework for the purpose of feasibility in the initial stages of enterprise establishment. Thus the contribution of the study is also twofold, namely the practical outcome of determining stakeholder reception for feasibility, and a secondary outcome of constructing a stakeholder analysis framework. The stakeholder analysis framework is based on an interpretation of existing stakeholder theory, with the addition of four "relational indicators" – goals, intentions, relationships, and resources. These four indicators provide a link between theory and practice in gauging the two attributes of stakeholder influence – power and interest. Dealing with a number of stakeholder interests in a unique context, the study takes on a single network case study approach in the paradigm of phenomenology. To suit the complex nature of the study, semi-structured interviews with various stakeholder representatives were conducted, using groups or organisations as units of analysis. Drawing from the stakeholder analysis framework and overall purpose of the study, four research objectives were set. The first was to identify the proposed enterprise's legitimate key external stakeholders, based on the three markets: water, carbon and tourism; the second to describe, categorise and assess relative dyadic influence of the above stakeholders by gauging their power and interest; the third, to determine the stakeholder network influence and probable reception of the proposed enterprise; and the last to advise the landowners on any identified opportunities or constraints stakeholders might pose, and thus to contribute to determining feasibility. In addressing the first objective, 21 stakeholders were identified, 12 of whom were found to be key to the current investigation. These key stakeholders were: Gamtoos Irrigation Board (GIB), LivingLands, R3G, Rhodes Restoration Group, Eastern Cape Parks and Tourism Agency (ECPTA), Department of Water Affairs (DWA), Nelson Mandela Bay Metropolitan (NMBM), Saaimanshoek, South African National Biodiversity Institute (SANBI), Department of Economic Development, Environmental Affairs and Tourism (DEDEAT), Baviaans Tourism, and Baviaans Municipality. In applying the stakeholder analysis framework, ECPTA was categorised as the definitive (most influential) stakeholder to the enterprise, and DEDEAT, SANBI (through Working for Wetlands), Baviaans Tourism, GIB, and NMBM were categorised as pivotal (influential and active). In discerning stakeholder interest in the proposed enterprise, a number of emerging themes were found to affect the projected interest and behaviour of stakeholders, apart from their specified goals. Emerging themes included: tunnel visioning, internal disparity, individual/personality clashes, and misaligned interests. In addition to this, in interpreting stakeholder interest, specific intentions or agendas that might affect the interest shown towards the proposed enterprise were also taken into account. Five predominant intentions of stakeholders were identified as: implementing a stewardship programme, establishing a tourism association, establishing a water users' association, social development, and "the big vision". Findings on the final objective revealed a number of perceived opportunities and constraints relative to the feasibility of the enterprise. Three prime opportunities were identified as: partnerships with definitive and pivotal stakeholders, the possibility of tendering for implementer of the "Working for" programmes, and taking on the role of Tourism Association. The following potential constraints were also emphasised by participants: social aspects such as individuals and personalities, the incompatibility or non-existence of local market structures, and the need for external funding. With regard to stakeholder reception, most of the stakeholders, with the exception of NMBM and Saaimanshoek, responded positively to the idea of the enterprise. Overall, based on participant perceptions, the tourism market was found to be the most feasible the carbon market uncertain and a long-term possibility, and the water market the least feasible.
- Full Text:
- Date Issued: 2014
- Authors: Wiles, Kira Leigh Deborah
- Date: 2014
- Subjects: Landowners -- South Africa -- Eastern Cape , Natural resources -- Co-management -- South Africa -- Eastern Cape , Land use -- Environmental aspects -- South Africa -- Eastern Cape , Land use -- Economic aspects -- South Africa -- Eastern Cape , Partnership -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1198 , http://hdl.handle.net/10962/d1012075 , Landowners -- South Africa -- Eastern Cape , Natural resources -- Co-management -- South Africa -- Eastern Cape , Land use -- Environmental aspects -- South Africa -- Eastern Cape , Land use -- Economic aspects -- South Africa -- Eastern Cape , Partnership -- South Africa -- Eastern Cape
- Description: In May 2012, a meeting was held between various stakeholder representatives of the Western Baviaanskloof to discuss the concept of a proposed landowner-enterprise. This concept was put forward in response to a need for collaboration in the midst of economic, environmental and social issues at play in the Baviaanskloof. Owing to the conservation value and rapidly decreasing economic output of the land, a radical shift to sustainable land-use practices was called for by various stakeholders. Suggested as a vehicle to generate income for the local landowners through alternative sustainable land-uses, the proposed enterprise may aid in addressing this shift by use of a bottom-up approach. During the stakeholder meeting, it was requested by the representative landowners that a feasibility assessment be conducted on the concept of the proposed enterprise prior to establishment. As an integral part of this assessment, the researcher took on the task of investigating stakeholder reception to the enterprise by means of a stakeholder analysis. It was decided to limit this to three markets: water, carbon and tourism. The purpose of this research study is twofold, namely to: investigate stakeholder influence and their reception of the proposed enterprise using a stakeholder analysis; and also to identify and advise on the opportunities and constraints relating to stakeholders, thus contributing to determining the feasibility of the proposed enterprise. In achieving the purpose of this study, a systematic stakeholder analysis framework was constructed, based on existing theory. This was necessary because, although stakeholder analysis is commonly practiced, no study was found to provide a theoretically based framework for the purpose of feasibility in the initial stages of enterprise establishment. Thus the contribution of the study is also twofold, namely the practical outcome of determining stakeholder reception for feasibility, and a secondary outcome of constructing a stakeholder analysis framework. The stakeholder analysis framework is based on an interpretation of existing stakeholder theory, with the addition of four "relational indicators" – goals, intentions, relationships, and resources. These four indicators provide a link between theory and practice in gauging the two attributes of stakeholder influence – power and interest. Dealing with a number of stakeholder interests in a unique context, the study takes on a single network case study approach in the paradigm of phenomenology. To suit the complex nature of the study, semi-structured interviews with various stakeholder representatives were conducted, using groups or organisations as units of analysis. Drawing from the stakeholder analysis framework and overall purpose of the study, four research objectives were set. The first was to identify the proposed enterprise's legitimate key external stakeholders, based on the three markets: water, carbon and tourism; the second to describe, categorise and assess relative dyadic influence of the above stakeholders by gauging their power and interest; the third, to determine the stakeholder network influence and probable reception of the proposed enterprise; and the last to advise the landowners on any identified opportunities or constraints stakeholders might pose, and thus to contribute to determining feasibility. In addressing the first objective, 21 stakeholders were identified, 12 of whom were found to be key to the current investigation. These key stakeholders were: Gamtoos Irrigation Board (GIB), LivingLands, R3G, Rhodes Restoration Group, Eastern Cape Parks and Tourism Agency (ECPTA), Department of Water Affairs (DWA), Nelson Mandela Bay Metropolitan (NMBM), Saaimanshoek, South African National Biodiversity Institute (SANBI), Department of Economic Development, Environmental Affairs and Tourism (DEDEAT), Baviaans Tourism, and Baviaans Municipality. In applying the stakeholder analysis framework, ECPTA was categorised as the definitive (most influential) stakeholder to the enterprise, and DEDEAT, SANBI (through Working for Wetlands), Baviaans Tourism, GIB, and NMBM were categorised as pivotal (influential and active). In discerning stakeholder interest in the proposed enterprise, a number of emerging themes were found to affect the projected interest and behaviour of stakeholders, apart from their specified goals. Emerging themes included: tunnel visioning, internal disparity, individual/personality clashes, and misaligned interests. In addition to this, in interpreting stakeholder interest, specific intentions or agendas that might affect the interest shown towards the proposed enterprise were also taken into account. Five predominant intentions of stakeholders were identified as: implementing a stewardship programme, establishing a tourism association, establishing a water users' association, social development, and "the big vision". Findings on the final objective revealed a number of perceived opportunities and constraints relative to the feasibility of the enterprise. Three prime opportunities were identified as: partnerships with definitive and pivotal stakeholders, the possibility of tendering for implementer of the "Working for" programmes, and taking on the role of Tourism Association. The following potential constraints were also emphasised by participants: social aspects such as individuals and personalities, the incompatibility or non-existence of local market structures, and the need for external funding. With regard to stakeholder reception, most of the stakeholders, with the exception of NMBM and Saaimanshoek, responded positively to the idea of the enterprise. Overall, based on participant perceptions, the tourism market was found to be the most feasible the carbon market uncertain and a long-term possibility, and the water market the least feasible.
- Full Text:
- Date Issued: 2014
Towards understanding the effects of stocking density on farmed South African abalone, Haliotis Midae
- Authors: Nicholson, Gareth Hurst
- Date: 2014
- Subjects: Haliotis midae -- South Africa , Haliotis midae fisheries -- South Africa , Abalones -- South Africa , Fish stocking -- South Africa , Abalone populations -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5371 , http://hdl.handle.net/10962/d1015646
- Description: The profitability of abalone farms is heavily influenced by their production per unit of grow-out space. With farms having physically expanded to the maximum, and with increasing production costs, one of the most realistic ways for farms to increase their production is through optimizing stocking densities. The effect of stocking density on Haliotis midae performance is undocumented and optimal stocking densities for this species have not been determined. Experiments were conducted under farm conditions to investigate the effects of four different stocking densities (16 %, 20 %, 22 % and 24 % of available surface area) on growth, production and health of three different size classes of abalone (15-35 g, 45-65 g, and 70-90 g start weight). Each treatment was replicated four times and trials ran over a period of eight months with measurements being made at four month intervals. Abalone behaviour was observed during the trials in the experimental tanks. Weight gain per abalone decreased with an increase in density for all tested size classes (5.04 ± 0.18 to 2.38 ± 0.17; 5.35 ± 0.21 to 4.62 ± 0.29; 7.97 ± 0.37 to 6.53 ± 0.28 g.abalone-1.month-1 for the 15-35, 45-65 and 70-90 g classes respectively, with an increased density of 16 to 24 %). Individual weight gain of 15-35 g abalone was similar at stocking densities of 16 % and 20 % while weight gain of 45-65 g and 70-90 g abalone decreased when density was increased above 16 %. Biomass gain (kg.basket-1.month-1) was not affected by stocking density in the 15-35 g and 45-65 g size classes (1.29 ± 0.02 and 0.97 ± 0.02 kg.basket-1.month-1 respectively). However, the biomass gained by baskets stocked with 70-90 g abalone increased with stocking density (1.08 ± 0.02 to 1.33 ± 0.02 kg.basket-1.month-1) with an increased density of 16 to 24 %) and did not appear to plateau within the tested density range (16 to 24 %). Food conversion ratio did not differ significantly between densities across all size classes. Stocking density did not have a significant effect on abalone condition factor or health indices. The proportion of abalone above the level of the feeder plate increased with density (7.26 ± 1.33 to 16.44 ± 1.33 with an increased density of 16 to 24 %). As a proportion of abalone situated in the area of the basket, the same proportions were situated on the walls above the feeder plate and on the feeder plate itself irrespective of stocking density (p > 0.05). Higher proportions of animals had restricted access to feed at higher stocking densities (p = 0.03). The amount of formulated feed available on the feeder plate did not differ between stocking densities throughout the night (p = 0.19). Individual abalone spent more time above the feeder plate at higher stocking densities (p < 0.05). The percentage of time above the feeder plate, spent on the walls of the basket and on the feeding surface was not significantly different at densities of 20 %, 22 % and 24 % (p > 0.05) but abalone stocked at 16 % spent a greater percentage of time above the feeder plate on the feeding surface (83.99 ± 6.26 %) than on the basket walls (16.01 ± 6.26 %). Stocking density did not affect the positioning of abalone within a basket during the day or at night. Different size H. midae are affected differently by increases in stocking density in terms of growth performance. Findings from this research may be implemented into farm management strategies to best suit production goals, whether in terms of biomass production or individual weight gain. The fundamental mechanisms resulting in reduced growth at higher densities are not well understood, however results from behaviour observations suggest that competition for preferred attachment space and feed availability are contributing to decreased growth rates. With knowledge of abalone behaviour at different densities, innovative tank designs may be established in order to counter the reduction in growth at higher densities.
- Full Text:
- Date Issued: 2014
- Authors: Nicholson, Gareth Hurst
- Date: 2014
- Subjects: Haliotis midae -- South Africa , Haliotis midae fisheries -- South Africa , Abalones -- South Africa , Fish stocking -- South Africa , Abalone populations -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5371 , http://hdl.handle.net/10962/d1015646
- Description: The profitability of abalone farms is heavily influenced by their production per unit of grow-out space. With farms having physically expanded to the maximum, and with increasing production costs, one of the most realistic ways for farms to increase their production is through optimizing stocking densities. The effect of stocking density on Haliotis midae performance is undocumented and optimal stocking densities for this species have not been determined. Experiments were conducted under farm conditions to investigate the effects of four different stocking densities (16 %, 20 %, 22 % and 24 % of available surface area) on growth, production and health of three different size classes of abalone (15-35 g, 45-65 g, and 70-90 g start weight). Each treatment was replicated four times and trials ran over a period of eight months with measurements being made at four month intervals. Abalone behaviour was observed during the trials in the experimental tanks. Weight gain per abalone decreased with an increase in density for all tested size classes (5.04 ± 0.18 to 2.38 ± 0.17; 5.35 ± 0.21 to 4.62 ± 0.29; 7.97 ± 0.37 to 6.53 ± 0.28 g.abalone-1.month-1 for the 15-35, 45-65 and 70-90 g classes respectively, with an increased density of 16 to 24 %). Individual weight gain of 15-35 g abalone was similar at stocking densities of 16 % and 20 % while weight gain of 45-65 g and 70-90 g abalone decreased when density was increased above 16 %. Biomass gain (kg.basket-1.month-1) was not affected by stocking density in the 15-35 g and 45-65 g size classes (1.29 ± 0.02 and 0.97 ± 0.02 kg.basket-1.month-1 respectively). However, the biomass gained by baskets stocked with 70-90 g abalone increased with stocking density (1.08 ± 0.02 to 1.33 ± 0.02 kg.basket-1.month-1) with an increased density of 16 to 24 %) and did not appear to plateau within the tested density range (16 to 24 %). Food conversion ratio did not differ significantly between densities across all size classes. Stocking density did not have a significant effect on abalone condition factor or health indices. The proportion of abalone above the level of the feeder plate increased with density (7.26 ± 1.33 to 16.44 ± 1.33 with an increased density of 16 to 24 %). As a proportion of abalone situated in the area of the basket, the same proportions were situated on the walls above the feeder plate and on the feeder plate itself irrespective of stocking density (p > 0.05). Higher proportions of animals had restricted access to feed at higher stocking densities (p = 0.03). The amount of formulated feed available on the feeder plate did not differ between stocking densities throughout the night (p = 0.19). Individual abalone spent more time above the feeder plate at higher stocking densities (p < 0.05). The percentage of time above the feeder plate, spent on the walls of the basket and on the feeding surface was not significantly different at densities of 20 %, 22 % and 24 % (p > 0.05) but abalone stocked at 16 % spent a greater percentage of time above the feeder plate on the feeding surface (83.99 ± 6.26 %) than on the basket walls (16.01 ± 6.26 %). Stocking density did not affect the positioning of abalone within a basket during the day or at night. Different size H. midae are affected differently by increases in stocking density in terms of growth performance. Findings from this research may be implemented into farm management strategies to best suit production goals, whether in terms of biomass production or individual weight gain. The fundamental mechanisms resulting in reduced growth at higher densities are not well understood, however results from behaviour observations suggest that competition for preferred attachment space and feed availability are contributing to decreased growth rates. With knowledge of abalone behaviour at different densities, innovative tank designs may be established in order to counter the reduction in growth at higher densities.
- Full Text:
- Date Issued: 2014
Trends in the fish assemblage structure of two South African transition-zone estuaries : can these trends be linked to climate change?
- Authors: Midgley, Craig
- Date: 2014
- Subjects: Estuarine fishes -- South Africa -- Climatic factors , Fish communities -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5368 , http://hdl.handle.net/10962/d1013173
- Description: Changes in the fish communities of the Breede and Mbashe estuaries were investigated in relation to the environmental variables that influence the fish assemblages in these systems. The Breede Estuary (34° 24’21.6”S, 20° 51’ 08.2”E) occurs within the warm-temperate/cool-temperate transition-zone, while the Mbashe Estuary (32o 14' 55.4"S, 28o 54' 03.7"E) falls within the subtropical/warm-temperate transition-zone along the South African coastline. The Breede Estuary was sampled (seine and gill nets) during summer (January-March) over a period of 10 years (2002-2012), while the Mbashe Estuary was sampled (seine net) during spring (October) over a period of three years (2010-2012). The proportion of tropical fish species was higher in the Mbashe Estuary compared to the Breede Estuary, while the Breede Estuary contained a higher proportion of temperate species than the Mbashe Estuary. Although the abundance of individual species in both estuaries varied, the ranking of species in the Breede Estuary was stable over the 10 year period. Multivariate analysis showed that the fish communities within each reach (upper, middle, lower) of the Breede Estuary remained similar, regardless of year. In contrast, species composition in the Mbashe Estuary differed significantly between years mainly due to differences in the river flow regime during the study period. Environmental variables responsible for structuring the fish assemblage in each estuary differed. Salinity significantly impacted the spatial fish assemblage structure of the Breede Estuary, with most of the species recorded being associated with the more saline lower reaches. The abundance of tropical species near their distributional limit in the Breede Estuary appeared to be impacted by sea surface temperature (SST) as peak total abundance of these species coincided with the warmest SST, while the lowest total abundance coincided with the coldest annual SST during the study period. The fish assemblage structure in the Mbashe Estuary was impacted by differing freshwater input prior to sampling, with flooding negatively impacting the mean total abundance, species composition and diversity in this system. The variables that influenced the fish assemblage structure of both transition-zone estuaries will be affected by climate change in the future. These variables will, in turn, determine the composition, abundance and diversity of species within these important estuarine systems. In order to measure these impacts with any degree of understanding, long-term studies on the abiotic and biotic (including the ichthyofauna) features of these estuaries are required to interpret climate change trends.
- Full Text:
- Date Issued: 2014
- Authors: Midgley, Craig
- Date: 2014
- Subjects: Estuarine fishes -- South Africa -- Climatic factors , Fish communities -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5368 , http://hdl.handle.net/10962/d1013173
- Description: Changes in the fish communities of the Breede and Mbashe estuaries were investigated in relation to the environmental variables that influence the fish assemblages in these systems. The Breede Estuary (34° 24’21.6”S, 20° 51’ 08.2”E) occurs within the warm-temperate/cool-temperate transition-zone, while the Mbashe Estuary (32o 14' 55.4"S, 28o 54' 03.7"E) falls within the subtropical/warm-temperate transition-zone along the South African coastline. The Breede Estuary was sampled (seine and gill nets) during summer (January-March) over a period of 10 years (2002-2012), while the Mbashe Estuary was sampled (seine net) during spring (October) over a period of three years (2010-2012). The proportion of tropical fish species was higher in the Mbashe Estuary compared to the Breede Estuary, while the Breede Estuary contained a higher proportion of temperate species than the Mbashe Estuary. Although the abundance of individual species in both estuaries varied, the ranking of species in the Breede Estuary was stable over the 10 year period. Multivariate analysis showed that the fish communities within each reach (upper, middle, lower) of the Breede Estuary remained similar, regardless of year. In contrast, species composition in the Mbashe Estuary differed significantly between years mainly due to differences in the river flow regime during the study period. Environmental variables responsible for structuring the fish assemblage in each estuary differed. Salinity significantly impacted the spatial fish assemblage structure of the Breede Estuary, with most of the species recorded being associated with the more saline lower reaches. The abundance of tropical species near their distributional limit in the Breede Estuary appeared to be impacted by sea surface temperature (SST) as peak total abundance of these species coincided with the warmest SST, while the lowest total abundance coincided with the coldest annual SST during the study period. The fish assemblage structure in the Mbashe Estuary was impacted by differing freshwater input prior to sampling, with flooding negatively impacting the mean total abundance, species composition and diversity in this system. The variables that influenced the fish assemblage structure of both transition-zone estuaries will be affected by climate change in the future. These variables will, in turn, determine the composition, abundance and diversity of species within these important estuarine systems. In order to measure these impacts with any degree of understanding, long-term studies on the abiotic and biotic (including the ichthyofauna) features of these estuaries are required to interpret climate change trends.
- Full Text:
- Date Issued: 2014
Trophic relationships of hake (Merluccius capensis Castelnau, 1851 and M. paradoxus Franca 1960) from the Northern Benguela current ecosystem (Namibia) : inferences from stable isotopes and fatty acids
- Authors: Iitembu, Johannes Angala
- Date: 2014
- Subjects: Hake -- Benguela Current , Merlucciidae -- Benguela Current , Multitrophic interactions (Ecology) , Food chains (Ecology) , Biotic communities -- Benguela Current , Merlucciidae -- Food , Fishery management -- Namibia , Stable isotopes , Fatty acids
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5944 , http://hdl.handle.net/10962/d1020296
- Description: Two species of hake (Merluccius capensis and Merluccius paradoxus) account for most of Namibia’s fisheries catch, and they are important secondary consumers in the Benguela Current ecosystem. Inferences on their trophic relationships have been based mainly on stomach content analyses. However, such data are limited temporally because they represent only snapshots of recent feeding, and are quantitatively biased because of variation in the digestion rates of different prey. The principal aim of the thesis was to understand the trophic relationships of two hake species relative to each other, their known prey and top predators (demersal sharks) in the northern Benguela Current ecosystem (Namibia), using time-integrating trophic biomarkers. By using stable isotope (carbon and nitrogen) and fatty acid signatures of their muscle tissues, my overall objectives were to produce new knowledge about 1) hake ontogenic trophic relationships, 2) the contributions of different prey to hake diets, 3) hake dietary differences, and 4) some aspects of hake’s trophic relationships with demersal sharks. Tissues of hake (n=358), their potential prey (n=455), and demersal sharks (n=42) were collected between 2008 and 2012 during demersal bottom trawl surveys off Namibia, for stable isotope and fatty acid analyses. And more...
- Full Text:
- Date Issued: 2014
- Authors: Iitembu, Johannes Angala
- Date: 2014
- Subjects: Hake -- Benguela Current , Merlucciidae -- Benguela Current , Multitrophic interactions (Ecology) , Food chains (Ecology) , Biotic communities -- Benguela Current , Merlucciidae -- Food , Fishery management -- Namibia , Stable isotopes , Fatty acids
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5944 , http://hdl.handle.net/10962/d1020296
- Description: Two species of hake (Merluccius capensis and Merluccius paradoxus) account for most of Namibia’s fisheries catch, and they are important secondary consumers in the Benguela Current ecosystem. Inferences on their trophic relationships have been based mainly on stomach content analyses. However, such data are limited temporally because they represent only snapshots of recent feeding, and are quantitatively biased because of variation in the digestion rates of different prey. The principal aim of the thesis was to understand the trophic relationships of two hake species relative to each other, their known prey and top predators (demersal sharks) in the northern Benguela Current ecosystem (Namibia), using time-integrating trophic biomarkers. By using stable isotope (carbon and nitrogen) and fatty acid signatures of their muscle tissues, my overall objectives were to produce new knowledge about 1) hake ontogenic trophic relationships, 2) the contributions of different prey to hake diets, 3) hake dietary differences, and 4) some aspects of hake’s trophic relationships with demersal sharks. Tissues of hake (n=358), their potential prey (n=455), and demersal sharks (n=42) were collected between 2008 and 2012 during demersal bottom trawl surveys off Namibia, for stable isotope and fatty acid analyses. And more...
- Full Text:
- Date Issued: 2014
Understanding and modelling of surface and groundwater interactions
- Authors: Tanner, Jane Louise
- Date: 2014
- Subjects: Groundwater -- South Africa , Water-supply -- Management , Integrated water development , Hydrogeology , Water resources development -- South Africa , Water -- Analysis , Groundwater -- Management , Watersheds -- South Africa , Hydrologic models
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:6043 , http://hdl.handle.net/10962/d1012994
- Description: The connections between surface water and groundwater systems remain poorly understood in many catchments throughout the world and yet they are fundamental to effectively managing water resources. Managing water resources in an integrated manner is not straightforward, particularly if both resources are being utilised, and especially in those regions that suffer problems of data scarcity. This study explores some of the principle issues associated with understanding and practically modelling surface and groundwater interactions. In South Africa, there remains much controversy over the most appropriate type of integrated model to be used and the way forward in terms of the development of the discipline; part of the disagreement stems from the fact that we cannot validate models adequately. This is largely due to traditional forms of model testing having limited power as it is difficult to differentiate between the uncertainties within different model structures, different sets of alternative parameter values and in the input data used to run the model. While model structural uncertainties are important to consider, the uncertainty from input data error together with parameter estimation error are often more significant to the overall residual error, and essential to consider if we want to achieve reliable predictions for water resource decisions. While new philosophies and theories on modelling and results validation have been developed (Beven, 2002; Gupta et al., 2008), in many cases models are not only still being validated and compared using sparse and uncertain datasets, but also expected to produce reliable predictions based on the flawed data. The approach in this study is focused on fundamental understanding of hydrological systems rather than calibration based modelling and promotes the use of all the available 'hard' and 'soft' data together with thoughtful conceptual examination of the processes occurring in an environment to ensure as far as possible that a model is generating sensible results by simulating the correct processes. The first part of the thesis focuses on characterising the 'typical' interaction environments found in South Africa. It was found that many traditional perceptual models are not necessarily applicable to South African conditions, largely due to the relative importance of unsaturated zone processes and the complexity of the dominantly fractured rock environments. The interaction environments were categorised into four main 'types' of environment. These include karst, primary, fractured rock (secondary), and alluvial environments. Processes critical to Integrated Water Resource Management (IWRM) were defined within each interaction type as a guideline to setting a model up to realistically represent the dominant processes in the respective settings. The second part of the thesis addressed the application and evaluation of the modified Pitman model (Hughes, 2004), which allows for surface and groundwater interaction behaviour at the catchment scale to be simulated. The issue is whether, given the different sources of uncertainty in the modelling process, we can differentiate one conceptual flow path from another in trying to refine the understanding and consequently have more faith in model predictions. Seven example catchments were selected from around South Africa to assess whether reliable integrated assessments can be carried out given the existing data. Specific catchment perceptual models were used to identify the critical processes occurring in each setting and the Pitman model was assessed on whether it could represent them (structural uncertainty). The available knowledge of specific environments or catchments was then examined in an attempt to resolve the parameter uncertainty present within each catchment and ensure the subsequent model setup was correctly representing the process understanding as far as possible. The confidence in the quantitative results inevitably varied with the amount and quality of the data available. While the model was deemed to be robust based on the behavioural results obtained in the majority of the case studies, in many cases a quantitative validation of the outputs was just not possible based on the available data. In these cases, the model was judged on its ability to represent the conceptualisation of the processes occurring in the catchments. While the lack of appropriate data means there will always be considerable uncertainty surrounding model validation, it can be argued that improved process understanding in an environment can be used to validate model outcomes to a degree, by assessing whether a model is getting the right results for the right reasons. Many water resource decisions are still made without adequate account being taken of the uncertainties inherent in assessing the response of hydrological systems. Certainly, with all the possible sources of uncertainty in a data scarce country such as South Africa, pure calibration based modelling is unlikely to produce reliable information for water resource managers as it can produce the right results for the wrong reasons. Thus it becomes essential to incorporate conceptual thinking into the modelling process, so that at the very least we are able to conclude that a model generates estimates that are consistent with, and reflect, our understanding (however limited) of the catchment processes. It is fairly clear that achieving the optimum model of a hydrological system may be fraught with difficulty, if not impossible. This makes it very difficult from a practitioner's point of view to decide which model and uncertainty estimation method to use. According to Beven (2009), this may be a transitional problem and in the future it may become clearer as we learn more about how to estimate the uncertainties associated with hydrological systems. Until then, a better understanding of the fundamental and most critical hydrogeological processes should be used to critically test and improve model predictions as far as possible. A major focus of the study was to identify whether the modified Pitman model could provide a practical tool for water resource managers by reliably determining the available water resource. The incorporation of surface and groundwater interaction routines seems to have resulted in a more robust and realistic model of basin hydrology. The overall conclusion is that the model, although simplified, is capable of representing the catchment scale processes that occur under most South African conditions.
- Full Text:
- Date Issued: 2014
- Authors: Tanner, Jane Louise
- Date: 2014
- Subjects: Groundwater -- South Africa , Water-supply -- Management , Integrated water development , Hydrogeology , Water resources development -- South Africa , Water -- Analysis , Groundwater -- Management , Watersheds -- South Africa , Hydrologic models
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:6043 , http://hdl.handle.net/10962/d1012994
- Description: The connections between surface water and groundwater systems remain poorly understood in many catchments throughout the world and yet they are fundamental to effectively managing water resources. Managing water resources in an integrated manner is not straightforward, particularly if both resources are being utilised, and especially in those regions that suffer problems of data scarcity. This study explores some of the principle issues associated with understanding and practically modelling surface and groundwater interactions. In South Africa, there remains much controversy over the most appropriate type of integrated model to be used and the way forward in terms of the development of the discipline; part of the disagreement stems from the fact that we cannot validate models adequately. This is largely due to traditional forms of model testing having limited power as it is difficult to differentiate between the uncertainties within different model structures, different sets of alternative parameter values and in the input data used to run the model. While model structural uncertainties are important to consider, the uncertainty from input data error together with parameter estimation error are often more significant to the overall residual error, and essential to consider if we want to achieve reliable predictions for water resource decisions. While new philosophies and theories on modelling and results validation have been developed (Beven, 2002; Gupta et al., 2008), in many cases models are not only still being validated and compared using sparse and uncertain datasets, but also expected to produce reliable predictions based on the flawed data. The approach in this study is focused on fundamental understanding of hydrological systems rather than calibration based modelling and promotes the use of all the available 'hard' and 'soft' data together with thoughtful conceptual examination of the processes occurring in an environment to ensure as far as possible that a model is generating sensible results by simulating the correct processes. The first part of the thesis focuses on characterising the 'typical' interaction environments found in South Africa. It was found that many traditional perceptual models are not necessarily applicable to South African conditions, largely due to the relative importance of unsaturated zone processes and the complexity of the dominantly fractured rock environments. The interaction environments were categorised into four main 'types' of environment. These include karst, primary, fractured rock (secondary), and alluvial environments. Processes critical to Integrated Water Resource Management (IWRM) were defined within each interaction type as a guideline to setting a model up to realistically represent the dominant processes in the respective settings. The second part of the thesis addressed the application and evaluation of the modified Pitman model (Hughes, 2004), which allows for surface and groundwater interaction behaviour at the catchment scale to be simulated. The issue is whether, given the different sources of uncertainty in the modelling process, we can differentiate one conceptual flow path from another in trying to refine the understanding and consequently have more faith in model predictions. Seven example catchments were selected from around South Africa to assess whether reliable integrated assessments can be carried out given the existing data. Specific catchment perceptual models were used to identify the critical processes occurring in each setting and the Pitman model was assessed on whether it could represent them (structural uncertainty). The available knowledge of specific environments or catchments was then examined in an attempt to resolve the parameter uncertainty present within each catchment and ensure the subsequent model setup was correctly representing the process understanding as far as possible. The confidence in the quantitative results inevitably varied with the amount and quality of the data available. While the model was deemed to be robust based on the behavioural results obtained in the majority of the case studies, in many cases a quantitative validation of the outputs was just not possible based on the available data. In these cases, the model was judged on its ability to represent the conceptualisation of the processes occurring in the catchments. While the lack of appropriate data means there will always be considerable uncertainty surrounding model validation, it can be argued that improved process understanding in an environment can be used to validate model outcomes to a degree, by assessing whether a model is getting the right results for the right reasons. Many water resource decisions are still made without adequate account being taken of the uncertainties inherent in assessing the response of hydrological systems. Certainly, with all the possible sources of uncertainty in a data scarce country such as South Africa, pure calibration based modelling is unlikely to produce reliable information for water resource managers as it can produce the right results for the wrong reasons. Thus it becomes essential to incorporate conceptual thinking into the modelling process, so that at the very least we are able to conclude that a model generates estimates that are consistent with, and reflect, our understanding (however limited) of the catchment processes. It is fairly clear that achieving the optimum model of a hydrological system may be fraught with difficulty, if not impossible. This makes it very difficult from a practitioner's point of view to decide which model and uncertainty estimation method to use. According to Beven (2009), this may be a transitional problem and in the future it may become clearer as we learn more about how to estimate the uncertainties associated with hydrological systems. Until then, a better understanding of the fundamental and most critical hydrogeological processes should be used to critically test and improve model predictions as far as possible. A major focus of the study was to identify whether the modified Pitman model could provide a practical tool for water resource managers by reliably determining the available water resource. The incorporation of surface and groundwater interaction routines seems to have resulted in a more robust and realistic model of basin hydrology. The overall conclusion is that the model, although simplified, is capable of representing the catchment scale processes that occur under most South African conditions.
- Full Text:
- Date Issued: 2014
Understanding development aid and state autonomy : the case of European Union budget support to Mozambique
- Authors: Ndlovu, Ana Admiração
- Date: 2014
- Subjects: Economic assistance, European -- Mozambique , Economic development -- Mozambique , Mozambique -- Economic conditions , Autonomy , Budget -- Mozambique
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:3378 , http://hdl.handle.net/10962/d1013218
- Description: Post-colonial states in Africa continue to pursue nation-building and socio-economic development. This process is taking place with the sustained support of global agencies in terms of development cooperation, assistance and aid. Insofar as an endogenous development path which speaks to national priorities can be formulated and implemented by post-colonial states, their relationship with these agencies raises serious questions about such a path if the relationship entails dependence and indeed subordination of post-colonial states. This raises important questions about state autonomy under post-colonial conditions and the possibility of autonomy being compromised. In this light, the thesis examines European Union budget support to Mozambique and, in particular, the relationship between EU budget support and Mozambique state autonomy in pursuing national development. This is particularly pertinent given the massive dependence of the Mozambican state on foreign funding (notably EU funding) with specific regard to the national budget. Despite the broad claims existing in the prevailing literature that nation-state autonomy is seriously undermined in and through the international development system, the thesis argues against reductionist arguments that simply posit post-colonial states as mere instruments of global forces. This system, including European Union budget support, does indeed set the conditions of existence for post-colonial states such as Mozambique. But autonomy is necessarily relative and is subject to different forms and degrees. Ultimately, it is through empirical investigation that the specific form and degree of autonomy can be pinpointed and understood. The thesis contributes to this endeavour and suggests that the relationship between European budget support and Mozambican state autonomy is more complex and tension-riddled than the prevailing literature would seem to suggest.
- Full Text:
- Date Issued: 2014
- Authors: Ndlovu, Ana Admiração
- Date: 2014
- Subjects: Economic assistance, European -- Mozambique , Economic development -- Mozambique , Mozambique -- Economic conditions , Autonomy , Budget -- Mozambique
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:3378 , http://hdl.handle.net/10962/d1013218
- Description: Post-colonial states in Africa continue to pursue nation-building and socio-economic development. This process is taking place with the sustained support of global agencies in terms of development cooperation, assistance and aid. Insofar as an endogenous development path which speaks to national priorities can be formulated and implemented by post-colonial states, their relationship with these agencies raises serious questions about such a path if the relationship entails dependence and indeed subordination of post-colonial states. This raises important questions about state autonomy under post-colonial conditions and the possibility of autonomy being compromised. In this light, the thesis examines European Union budget support to Mozambique and, in particular, the relationship between EU budget support and Mozambique state autonomy in pursuing national development. This is particularly pertinent given the massive dependence of the Mozambican state on foreign funding (notably EU funding) with specific regard to the national budget. Despite the broad claims existing in the prevailing literature that nation-state autonomy is seriously undermined in and through the international development system, the thesis argues against reductionist arguments that simply posit post-colonial states as mere instruments of global forces. This system, including European Union budget support, does indeed set the conditions of existence for post-colonial states such as Mozambique. But autonomy is necessarily relative and is subject to different forms and degrees. Ultimately, it is through empirical investigation that the specific form and degree of autonomy can be pinpointed and understood. The thesis contributes to this endeavour and suggests that the relationship between European budget support and Mozambican state autonomy is more complex and tension-riddled than the prevailing literature would seem to suggest.
- Full Text:
- Date Issued: 2014
Understanding educators' and learners' perceptions and experiences of their participation in Science Fairs/Expos : a South African case study.
- Authors: Kahenge, Wendelina Nambahu
- Date: 2014
- Subjects: Science fairs -- South Africa -- Grahamstown , Science -- Study and teaching -- South Africa -- Grahamstown , Vocational guidance -- South Africa -- Grahamstown , School children -- South Africa -- Attitudes , Teachers -- South Africa -- Attitudes , Teacher effectiveness -- South Africa -- Grahamstown
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1981 , http://hdl.handle.net/10962/d1013130
- Description: The rationale behind Science Expos is to develop and empower learners to be able to identify problems and find solutions (Eskom Expo Project Guide Book, 2013). It is believed that involvement in Science Expos arouses learners' interest to pursue science related careers. But despite these ideals, there is still poor participation in Science Expos by educators and learners. I conducted this case study in five schools in Grahamstown, Eastern Cape, South Africa. The purpose of this study was to understand educators' and learners' perceptions and experiences of their participation in Science Expos. The case study was designed within an interpretive paradigm. The data were generated, triangulated and validated by a variety of methods, namely, document analysis, interviews (semi-structured and focus group) and observations. The main findings of the study were that learners who participate in Science Expos attend workshops organised by Scifest and SAEON office with the help of some of the educators and lecturers from Rhodes University. Learners' participation was influenced and assisted by the educators and peers with whom they were able to communicate and share their projects with. It emerged from the study that, as a result of participating in Science Expos, educators (teachers) and learners were exposed to a wide variety of scientific investigations and skills that are necessary for their classroom based-scientific investigations. It also emerged from this study that educators and learners face the challenge of a lack of motivation; insufficient support from schools and parents; time constraints to support learners in their participation and a lack of knowledge among some educators on their learners' projects. Some learners are even discouraged from participating in Science Expos by their peers on the grounds that they have no chance of winning. Teachers therefore require continuous mentorship and capacity building in order to encourage their learners to partake.
- Full Text:
- Date Issued: 2014
- Authors: Kahenge, Wendelina Nambahu
- Date: 2014
- Subjects: Science fairs -- South Africa -- Grahamstown , Science -- Study and teaching -- South Africa -- Grahamstown , Vocational guidance -- South Africa -- Grahamstown , School children -- South Africa -- Attitudes , Teachers -- South Africa -- Attitudes , Teacher effectiveness -- South Africa -- Grahamstown
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1981 , http://hdl.handle.net/10962/d1013130
- Description: The rationale behind Science Expos is to develop and empower learners to be able to identify problems and find solutions (Eskom Expo Project Guide Book, 2013). It is believed that involvement in Science Expos arouses learners' interest to pursue science related careers. But despite these ideals, there is still poor participation in Science Expos by educators and learners. I conducted this case study in five schools in Grahamstown, Eastern Cape, South Africa. The purpose of this study was to understand educators' and learners' perceptions and experiences of their participation in Science Expos. The case study was designed within an interpretive paradigm. The data were generated, triangulated and validated by a variety of methods, namely, document analysis, interviews (semi-structured and focus group) and observations. The main findings of the study were that learners who participate in Science Expos attend workshops organised by Scifest and SAEON office with the help of some of the educators and lecturers from Rhodes University. Learners' participation was influenced and assisted by the educators and peers with whom they were able to communicate and share their projects with. It emerged from the study that, as a result of participating in Science Expos, educators (teachers) and learners were exposed to a wide variety of scientific investigations and skills that are necessary for their classroom based-scientific investigations. It also emerged from this study that educators and learners face the challenge of a lack of motivation; insufficient support from schools and parents; time constraints to support learners in their participation and a lack of knowledge among some educators on their learners' projects. Some learners are even discouraged from participating in Science Expos by their peers on the grounds that they have no chance of winning. Teachers therefore require continuous mentorship and capacity building in order to encourage their learners to partake.
- Full Text:
- Date Issued: 2014
Understanding how trainee teachers engage with prior everyday knowledge and experience associated with biological concepts during integrated natural science education 5-7 : a case study
- Authors: Enghono, Albertina Magano
- Date: 2014
- Subjects: Biology teachers -- Training of -- Namibia -- Case studies Teacher educators -- Training of -- Case studies Teachers -- Training of -- Namibia -- Case studies Education -- Namibia -- Case studies Prior learning -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1970 , http://hdl.handle.net/10962/d1011972
- Description: Since the Namibian independence in 1990, the education system has undergone some major revamping which involved the adoption of social constructivist perspectives in the teaching and learning of sciences. This learning theory acknowledges learners’ background prior knowledge as valuable tools in the effective construction of science concepts during lessons. A corollary is that the socio-cultural circumstances of learners might negatively influence the way learners construct new knowledge in the science classroom if they are not taken into consideration. This study was thus prompted by the need to understand how trainee science teachers engage with prior everyday knowledge and experiences, so as to enhance the conceptual development of biological concepts. The study was qualitative and it was underpinned by an interpretive paradigm with some elements of action research. Science trainee teachers at Katima Mulilo, Unam Campus were used as research participants. The techniques used to gather data included document analysis, brainstorming, observation, audio-visual, microteaching and semi-structured interviews. The results of this study showed that the changes that occurred during microteaching practices of the four trainee teachers involved in the study reflected their professional development in this approach. However, it emerged that prior everyday knowledge can be both a barrier and enabler to the construction of meaningful teaching and learning; hence its oversight may lead to instructional failures. The findings also indicated that selected platforms are essential to enable trainee teachers to incorporate prior everyday knowledge and experiences into the teaching of Western science. However, larger scale study should be conducted in order to deepen the understanding of the topic.
- Full Text:
- Date Issued: 2014
- Authors: Enghono, Albertina Magano
- Date: 2014
- Subjects: Biology teachers -- Training of -- Namibia -- Case studies Teacher educators -- Training of -- Case studies Teachers -- Training of -- Namibia -- Case studies Education -- Namibia -- Case studies Prior learning -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1970 , http://hdl.handle.net/10962/d1011972
- Description: Since the Namibian independence in 1990, the education system has undergone some major revamping which involved the adoption of social constructivist perspectives in the teaching and learning of sciences. This learning theory acknowledges learners’ background prior knowledge as valuable tools in the effective construction of science concepts during lessons. A corollary is that the socio-cultural circumstances of learners might negatively influence the way learners construct new knowledge in the science classroom if they are not taken into consideration. This study was thus prompted by the need to understand how trainee science teachers engage with prior everyday knowledge and experiences, so as to enhance the conceptual development of biological concepts. The study was qualitative and it was underpinned by an interpretive paradigm with some elements of action research. Science trainee teachers at Katima Mulilo, Unam Campus were used as research participants. The techniques used to gather data included document analysis, brainstorming, observation, audio-visual, microteaching and semi-structured interviews. The results of this study showed that the changes that occurred during microteaching practices of the four trainee teachers involved in the study reflected their professional development in this approach. However, it emerged that prior everyday knowledge can be both a barrier and enabler to the construction of meaningful teaching and learning; hence its oversight may lead to instructional failures. The findings also indicated that selected platforms are essential to enable trainee teachers to incorporate prior everyday knowledge and experiences into the teaching of Western science. However, larger scale study should be conducted in order to deepen the understanding of the topic.
- Full Text:
- Date Issued: 2014
Understanding the livelihoods of child-grant mothers in Sinathingi in KwaZulu-Natal, South Africa
- Motsetse, Matsepo Nomathemba
- Authors: Motsetse, Matsepo Nomathemba
- Date: 2014
- Subjects: Welfare recipients -- South Africa -- KwaZulu-Natal , Social security -- South Africa , Family policy -- South Africa , Women -- South Africa -- KwaZulu-Natal -- Social conditions , Women -- South Africa -- KwaZulu-Natal -- Economic conditions , Poverty -- South Africa , Income -- South Africa -- KwaZulu-Natal
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:3380 , http://hdl.handle.net/10962/d1013284
- Description: The main focus of this thesis is the child support grant, as part of a broader social security system, in post-apartheid South Africa. Since the end of apartheid of 1994, the new South African government has sought to redress the racial imbalances and inequalities of the past by engaging in measures of redistribution. Central to this pursuit of redistribution has been a restructured system of social grants, of which the child support grant is the most significant. However, the post-apartheid government has adopted a largely neo-liberal macro-economic strategy such that social inequality and endemic poverty remain pervasive particularly amongst the African population, which includes the recipients of the child support grants. In adopting a sustainable livelihoods framework as the main theoretical perspective, the thesis seeks to understand the livelihoods of child support grant mothers in the face of conditions of extreme poverty. It does this through a localised study of twenty child grant mothers in Sinathingi Township in KwaZulu-Natal Province. In examining the livelihoods of these child-grant mothers, the thesis brings to the fore that mothers and their children do not exist as autonomous living units but are embedded in a broader set of social relations, including intra-household relations and relations with the fathers of the grant-children. It also demonstrates that child-grant mothers are not simply victims of structures of poverty in contemporary South Africa, but actively construct their livelihoods through a range of activities and strategies which show perseverance and ingenuity.
- Full Text:
- Date Issued: 2014
- Authors: Motsetse, Matsepo Nomathemba
- Date: 2014
- Subjects: Welfare recipients -- South Africa -- KwaZulu-Natal , Social security -- South Africa , Family policy -- South Africa , Women -- South Africa -- KwaZulu-Natal -- Social conditions , Women -- South Africa -- KwaZulu-Natal -- Economic conditions , Poverty -- South Africa , Income -- South Africa -- KwaZulu-Natal
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:3380 , http://hdl.handle.net/10962/d1013284
- Description: The main focus of this thesis is the child support grant, as part of a broader social security system, in post-apartheid South Africa. Since the end of apartheid of 1994, the new South African government has sought to redress the racial imbalances and inequalities of the past by engaging in measures of redistribution. Central to this pursuit of redistribution has been a restructured system of social grants, of which the child support grant is the most significant. However, the post-apartheid government has adopted a largely neo-liberal macro-economic strategy such that social inequality and endemic poverty remain pervasive particularly amongst the African population, which includes the recipients of the child support grants. In adopting a sustainable livelihoods framework as the main theoretical perspective, the thesis seeks to understand the livelihoods of child support grant mothers in the face of conditions of extreme poverty. It does this through a localised study of twenty child grant mothers in Sinathingi Township in KwaZulu-Natal Province. In examining the livelihoods of these child-grant mothers, the thesis brings to the fore that mothers and their children do not exist as autonomous living units but are embedded in a broader set of social relations, including intra-household relations and relations with the fathers of the grant-children. It also demonstrates that child-grant mothers are not simply victims of structures of poverty in contemporary South Africa, but actively construct their livelihoods through a range of activities and strategies which show perseverance and ingenuity.
- Full Text:
- Date Issued: 2014