An Assessment of the Effect of Rotenone on Selected Non-Target Aquatic Fauna: Reflections on Henri Lefebre, Urban Theory and the Politics of Scale
- Dalu, Tatenda, Wasserman, Ryan J, Jordaan, Martine, Froneman, Pierre William
- Authors: Dalu, Tatenda , Wasserman, Ryan J , Jordaan, Martine , Froneman, Pierre William
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/70425 , vital:29654 , https://doi.org/10.1371/journal.pone.0142140
- Description: Rotenone, a naturally occurring ketone, is widely employed for the management of invasive fish species. The use of rotenone poses serious challenges to conservation practitioners due to its impacts on non-target organisms including amphibians and macroinvertebrates. Using laboratory studies, we investigated the effects of different rotenone concentrations (0,12.5, 25, 37.5, 50, 100 μg L-1) on selected invertebrate groups; Aeshnidae, Belostomatids, Decapods, Ephemeroptera, Pulmonata and zooplankton over a period of 18 hours. Based on field observations and body size, we hypothesized that Ephemeropterans and zooplankton would be more susceptible to rotenone than Decapods, Belostomatids and snails. Experimental results supported this hypothesis and mortality and behaviour effects varied considerably between taxa, ranging from no effect (crab Potamonuates sidneyi) to 100% mortality (Daphnia pulex and Paradiaptomus lamellatus). Planktonic invertebrates were particularly sensitive to rotenone even at very low concentrations. Future research should investigate the recovery time of invertebrate communities after the application of rotenone and conduct field assessments assessing the longer term effects of rotenone exposure on the population dynamics of those less sensitive organisms.
- Full Text:
- Date Issued: 2015
- Authors: Dalu, Tatenda , Wasserman, Ryan J , Jordaan, Martine , Froneman, Pierre William
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/70425 , vital:29654 , https://doi.org/10.1371/journal.pone.0142140
- Description: Rotenone, a naturally occurring ketone, is widely employed for the management of invasive fish species. The use of rotenone poses serious challenges to conservation practitioners due to its impacts on non-target organisms including amphibians and macroinvertebrates. Using laboratory studies, we investigated the effects of different rotenone concentrations (0,12.5, 25, 37.5, 50, 100 μg L-1) on selected invertebrate groups; Aeshnidae, Belostomatids, Decapods, Ephemeroptera, Pulmonata and zooplankton over a period of 18 hours. Based on field observations and body size, we hypothesized that Ephemeropterans and zooplankton would be more susceptible to rotenone than Decapods, Belostomatids and snails. Experimental results supported this hypothesis and mortality and behaviour effects varied considerably between taxa, ranging from no effect (crab Potamonuates sidneyi) to 100% mortality (Daphnia pulex and Paradiaptomus lamellatus). Planktonic invertebrates were particularly sensitive to rotenone even at very low concentrations. Future research should investigate the recovery time of invertebrate communities after the application of rotenone and conduct field assessments assessing the longer term effects of rotenone exposure on the population dynamics of those less sensitive organisms.
- Full Text:
- Date Issued: 2015
An exploration of business level strategy at the bottom of the pyramid: a case study of Twizza, Eastern Cape
- Authors: Sityoshwana, Ludwe Lusu
- Date: 2015
- Language: English
- Type: text , Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10962/54486 , vital:26569
- Description: This qualitative study focuses on business level strategy adopted by Twizza to compete in the bottom of the pyramid market in the Eastern Cape, South Africa. Twizza enjoyed huge success between the years 2010 - 2014 as a medium to large sized manufacturer of carbonated soft drinks in the Eastern Cape. In light of this, the current study seeks to answer the following: What business level strategy did top management at Twizza adopt to compete and grow in the BoP market in the Eastern Cape, South Africa? The study takes the form of a case study to explore and understand the patterns of decisions adopted by Twizza’s top management in competing at the bottom of the pyramid. As such, the main objective of the study was to identify the business level strategy adopted by Twizza which enabled their superior performance within the BoP market. The study adopts Porter`s typology to explore business level strategy. Stratified, purposive sampling was used to identify 4 top managers as participants in this study. A total of 7, semi-structured, interviews were used to collect critical incidents from top management of Twizza. This was the primary data used in this study. This type of data was combined with relevant information which was gathered via published press articles and on-line commentary. The study found that central to Twizza’s business strategy were four pillars, namely, strict control and management of manufacturing costs, product quality equal to that of market leaders, the ability of the organisation to manufacture its own raw materials and ability to ensure product availability to the market to the market. These findings reveal that Twizza employed a hybrid strategy, anchored by cost leadership. Thus, Twizza incorporated elements of differentiation and best value strategies to offer its customers affordable quality.
- Full Text:
- Date Issued: 2015
- Authors: Sityoshwana, Ludwe Lusu
- Date: 2015
- Language: English
- Type: text , Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10962/54486 , vital:26569
- Description: This qualitative study focuses on business level strategy adopted by Twizza to compete in the bottom of the pyramid market in the Eastern Cape, South Africa. Twizza enjoyed huge success between the years 2010 - 2014 as a medium to large sized manufacturer of carbonated soft drinks in the Eastern Cape. In light of this, the current study seeks to answer the following: What business level strategy did top management at Twizza adopt to compete and grow in the BoP market in the Eastern Cape, South Africa? The study takes the form of a case study to explore and understand the patterns of decisions adopted by Twizza’s top management in competing at the bottom of the pyramid. As such, the main objective of the study was to identify the business level strategy adopted by Twizza which enabled their superior performance within the BoP market. The study adopts Porter`s typology to explore business level strategy. Stratified, purposive sampling was used to identify 4 top managers as participants in this study. A total of 7, semi-structured, interviews were used to collect critical incidents from top management of Twizza. This was the primary data used in this study. This type of data was combined with relevant information which was gathered via published press articles and on-line commentary. The study found that central to Twizza’s business strategy were four pillars, namely, strict control and management of manufacturing costs, product quality equal to that of market leaders, the ability of the organisation to manufacture its own raw materials and ability to ensure product availability to the market to the market. These findings reveal that Twizza employed a hybrid strategy, anchored by cost leadership. Thus, Twizza incorporated elements of differentiation and best value strategies to offer its customers affordable quality.
- Full Text:
- Date Issued: 2015
An exploration of the principle of Dance Movement Therapy in water resource management research practice:
- Authors: Copteros, Athina
- Date: 2015
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/142016 , vital:38024 , ISBN PECS Conference: Social-ecological dynamics in the Anthropocene, Spier Estate, Cape Town, 2-5 November , http://www.pecs-science.org/research/news/news/2015pecsconferencesocialecologicaldynamicsintheanthropocene.5.40768cbb14b32a0480b694.html
- Description: An exploration of the principle of Dance Movement Therapy in water resource management research practice
- Full Text:
- Date Issued: 2015
- Authors: Copteros, Athina
- Date: 2015
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/142016 , vital:38024 , ISBN PECS Conference: Social-ecological dynamics in the Anthropocene, Spier Estate, Cape Town, 2-5 November , http://www.pecs-science.org/research/news/news/2015pecsconferencesocialecologicaldynamicsintheanthropocene.5.40768cbb14b32a0480b694.html
- Description: An exploration of the principle of Dance Movement Therapy in water resource management research practice
- Full Text:
- Date Issued: 2015
An investigation into the feasibility of incorporating ketoconazole into solid lipid microparticles
- Authors: Jhundoo, Henusha Devi
- Date: 2015
- Language: English
- Type: text , Thesis , Masters , MPharm
- Identifier: http://hdl.handle.net/10962/54701 , vital:26601
- Description: One of the major challenges of the oral administration of ketoconazole (KTZ), an inhibitor of sterol 14α demethylase, used in the management of systemic and topical mycoses in immuno-compromised and paediatric patients is the lack of availability of liquid dosage forms. In order to overcome this challenge, extemporaneous preparations have been manufactured by care-givers and health care providers by crushing or breaking solid oral dosage forms of KTZ and mixing with a vehicle to produce a liquid dosage form that can be swallowed by patients. However, the use of extemporaneous preparations may lead to under or over-dosing if the care-givers are not guided accordingly. Furthermore, the dearth of information on the stability of these KTZ-containing extemporaneous preparations may lead to ineffective antifungal therapy and complicate the problems of resistance as it is difficult to estimate the shelf-lives of these extemporaneous products under varying storage conditions due to the susceptibility of KTZ to chemical degradation. Therefore, there is a need for formulation scientists to develop novel drug delivery systems that avoid the need for extemporaneous preparations, possess well-established limits of stability and minimize the risks of systemic adverse effects to facilitate KTZ therapy. The use of solid lipid microparticles (SLM) as potential carriers for the oral administration of KTZ was investigated since solid lipid carriers are known to exhibit the advantages of traditional colloidal carriers. The research undertaken in these studies aimed to investigate the feasibility of developing and manufacturing solid lipid microparticles (SLM), using a simple micro-emulsion technique, as a carrier for KTZ. Prior to pre-formulation, formulation development and optimization studies of KTZ-loaded SLM, it was necessary to develop and validate an analytical method for the in vitro quantitation and characterization of KTZ in aqueous dispersions of SLM during development and assessment studies. An accurate, precise, specific and sensitive reversed-phase high performance liquid chromatographic (RP-HPLC) method coupled with UV detection at 206 nm was developed, optimized and validated for the analysis of KTZ in formulations. Formulation development studies were preceded by solubility studies of KTZ in different lipids. Labrafil® M2130 CS was found to exhibit the best solubilising potential for KTZ. Pre-formulation studies were also designed to determine the polymorphic behavior and the crystallinity of KTZ and Labrafil® M2130 CS that was used for subsequent manufacture of the solid lipid carriers. DSC and FTIR studies revealed that there were no changes in the crystallinity of KTZ or Labrafil® M2130 CS following exposure to a temperature of 60°C for 1 hour. In addition the potential for physicochemical interaction of KTZ with the lipid Labrafil® M2130 CS was investigated using DSC and FTIR and the results revealed that KTZ was molecularly dispersed in Labrafil® M2130 CS and that it is unlikely that KTZ would interact with the lipid. It was therefore established that KTZ and Labrafil® M2130 CS were thermo-stable at a temperature of 60°C and thus a micro-emulsion technique could be used to manufacture the KTZ-loaded SLM. Drug-free and KTZ-loaded SLM were prepared using a modified micro-emulsion technique that required the use of an Ultra-Turrax® homogenizer set at 24 000 rpm for 5 minutes followed by the use of the Erweka GmbH homogenizer. SLM were characterized in terms of particle size (PS), zeta potential (ZP), shape and surface morphology using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). In addition drug loading capacity (DLC) and encapsulation efficiency (EE) of SLM for KTZ were assessed using RP-HPLC. Formulation development and optimization studies of KTZ-loaded SLM were initially aimed at selecting an emulsifying system that was able to stabilize the SLM in an aqueous dispersion. Successful formulations were selected based on their ability to remain physically stable on the day of manufacture. Pluronic® F68 used in combination with Lutrol® E40, Soluphor® P, Soluplus® produced unstable dispersions on the day of manufacture and these combinations were not investigated further. However, the formulation of a stable KTZ-loaded SLM dispersion was accomplished by use of a combination of Pluronic® F68, Tween 80 and sodium cholate as the surfactant system. Increasing amounts of Labrafil® M2130 CS resulted in the production of particles with low DLC and EE, a large PS and a relatively unchanged ZP. An optimum concentration of 10% w/v Labrafil® M2130 CS was selected to manufacture the KTZ-loaded SLM. Studies to determine the influence of KTZ loading on the quality of SLM revealed that concentrations of KTZ > 5% w/v led to a reduction in DLC and EE and an increase in PS with minimal impact on the ZP. Stability studies conducted at 25°C/65% RH and 40°C/75% RH for up to 30 days following manufacture revealed that batch SLM 15 manufactured using 10% w/v Labrafil® M2130 CS, 5% w/v KTZ and a combination of 4% w/v Pluronic® F-68, 2% w/v Tween 80 and 1% w/v sodium cholate produced the most stable dosage form when stored at 25°C/65% RH for up to 30 days. However, storage at 40°C/75% RH resulted in instability of the formulation. An aqueous dispersion of KTZ-loaded SLM has been developed and assessed and may offer an alternative to extemporaneous preparations used for KTZ therapy in paediatric and immuno-compromised patients.
- Full Text:
- Date Issued: 2015
- Authors: Jhundoo, Henusha Devi
- Date: 2015
- Language: English
- Type: text , Thesis , Masters , MPharm
- Identifier: http://hdl.handle.net/10962/54701 , vital:26601
- Description: One of the major challenges of the oral administration of ketoconazole (KTZ), an inhibitor of sterol 14α demethylase, used in the management of systemic and topical mycoses in immuno-compromised and paediatric patients is the lack of availability of liquid dosage forms. In order to overcome this challenge, extemporaneous preparations have been manufactured by care-givers and health care providers by crushing or breaking solid oral dosage forms of KTZ and mixing with a vehicle to produce a liquid dosage form that can be swallowed by patients. However, the use of extemporaneous preparations may lead to under or over-dosing if the care-givers are not guided accordingly. Furthermore, the dearth of information on the stability of these KTZ-containing extemporaneous preparations may lead to ineffective antifungal therapy and complicate the problems of resistance as it is difficult to estimate the shelf-lives of these extemporaneous products under varying storage conditions due to the susceptibility of KTZ to chemical degradation. Therefore, there is a need for formulation scientists to develop novel drug delivery systems that avoid the need for extemporaneous preparations, possess well-established limits of stability and minimize the risks of systemic adverse effects to facilitate KTZ therapy. The use of solid lipid microparticles (SLM) as potential carriers for the oral administration of KTZ was investigated since solid lipid carriers are known to exhibit the advantages of traditional colloidal carriers. The research undertaken in these studies aimed to investigate the feasibility of developing and manufacturing solid lipid microparticles (SLM), using a simple micro-emulsion technique, as a carrier for KTZ. Prior to pre-formulation, formulation development and optimization studies of KTZ-loaded SLM, it was necessary to develop and validate an analytical method for the in vitro quantitation and characterization of KTZ in aqueous dispersions of SLM during development and assessment studies. An accurate, precise, specific and sensitive reversed-phase high performance liquid chromatographic (RP-HPLC) method coupled with UV detection at 206 nm was developed, optimized and validated for the analysis of KTZ in formulations. Formulation development studies were preceded by solubility studies of KTZ in different lipids. Labrafil® M2130 CS was found to exhibit the best solubilising potential for KTZ. Pre-formulation studies were also designed to determine the polymorphic behavior and the crystallinity of KTZ and Labrafil® M2130 CS that was used for subsequent manufacture of the solid lipid carriers. DSC and FTIR studies revealed that there were no changes in the crystallinity of KTZ or Labrafil® M2130 CS following exposure to a temperature of 60°C for 1 hour. In addition the potential for physicochemical interaction of KTZ with the lipid Labrafil® M2130 CS was investigated using DSC and FTIR and the results revealed that KTZ was molecularly dispersed in Labrafil® M2130 CS and that it is unlikely that KTZ would interact with the lipid. It was therefore established that KTZ and Labrafil® M2130 CS were thermo-stable at a temperature of 60°C and thus a micro-emulsion technique could be used to manufacture the KTZ-loaded SLM. Drug-free and KTZ-loaded SLM were prepared using a modified micro-emulsion technique that required the use of an Ultra-Turrax® homogenizer set at 24 000 rpm for 5 minutes followed by the use of the Erweka GmbH homogenizer. SLM were characterized in terms of particle size (PS), zeta potential (ZP), shape and surface morphology using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). In addition drug loading capacity (DLC) and encapsulation efficiency (EE) of SLM for KTZ were assessed using RP-HPLC. Formulation development and optimization studies of KTZ-loaded SLM were initially aimed at selecting an emulsifying system that was able to stabilize the SLM in an aqueous dispersion. Successful formulations were selected based on their ability to remain physically stable on the day of manufacture. Pluronic® F68 used in combination with Lutrol® E40, Soluphor® P, Soluplus® produced unstable dispersions on the day of manufacture and these combinations were not investigated further. However, the formulation of a stable KTZ-loaded SLM dispersion was accomplished by use of a combination of Pluronic® F68, Tween 80 and sodium cholate as the surfactant system. Increasing amounts of Labrafil® M2130 CS resulted in the production of particles with low DLC and EE, a large PS and a relatively unchanged ZP. An optimum concentration of 10% w/v Labrafil® M2130 CS was selected to manufacture the KTZ-loaded SLM. Studies to determine the influence of KTZ loading on the quality of SLM revealed that concentrations of KTZ > 5% w/v led to a reduction in DLC and EE and an increase in PS with minimal impact on the ZP. Stability studies conducted at 25°C/65% RH and 40°C/75% RH for up to 30 days following manufacture revealed that batch SLM 15 manufactured using 10% w/v Labrafil® M2130 CS, 5% w/v KTZ and a combination of 4% w/v Pluronic® F-68, 2% w/v Tween 80 and 1% w/v sodium cholate produced the most stable dosage form when stored at 25°C/65% RH for up to 30 days. However, storage at 40°C/75% RH resulted in instability of the formulation. An aqueous dispersion of KTZ-loaded SLM has been developed and assessed and may offer an alternative to extemporaneous preparations used for KTZ therapy in paediatric and immuno-compromised patients.
- Full Text:
- Date Issued: 2015
An investigation of source rocks and depositional environments on acid mine drainage in South African coal mines: a comparison of the main karoo basin and sub-basins.
- Authors: Ncube, Lindani
- Date: 2015
- Subjects: Mine drainage--Environmental aspects--South Africa , Coal mines and mining--Environmental aspects--South Africa , Acid mine drainage--Environmental aspects--South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/19556 , vital:43139
- Description: The coal deposits have been and continue to be the primary source of energy in South Africa. The continuous use of coal presents many challenges that includes genesis of acid mine drainage (AMD) which is as a result of the oxidation of predominant pyrite (FeS2) and other sulphides. The aim of this study was to investigate the role of source rocks and their depositional environments on AMD generation in South African coal mine environments. Five collieries from five coalfields were selected as case studies: Brandspruit in the Highveld, Vaalkrantz in the Vryheid, the Elitheni in the Molteno-Indwe, the Arnot in the Witbank and the Malatleng Exploration Project in the Waterberg Coalfields. Brandspruit, Vaalkrantz and Elitheni Collieries are located in the Main Karoo Basin, while the Witbank and the Waterberg Coalfields are located in Sub-Basins. The study investigated a variety of indices such as palaeo-depositional environments, mineral assemblages, geochemical signatures, water quality parameters, acid base accounting (ABA) and water leach tests for the coal and associated non-coal strata. An effort was made to establish the relationship between the mineralogy of the studied lithologies and the associated water quality. The study resulted in delineation of detrital and diagenetic rock components and interpretation of source area of rock types and the origin and timing of diagenetic alterations. Sandstone units are prevalent, except in the Waterberg Coalfield where mudstones are prevalent. Classifications of the mineralogical composition with descriptive adjectives yield the rock names arkose to sub-arkose categories in the Main Karoo Basin, and sub-arenites to quartz arenites in the Sub-Basins with the sandstones of recycled origin. Further, the sandstones of the Main Karoo Basin are of mixed provenance whilst those of Sub-Basins represent cratonic interior provenance. Sandstone from the Main Karoo Basin generally exhibit high concentrations of feldspars, which favour either high relief, arid or arctic climates with less chemical weathering at the source area. The presence of glauconite in sediments of the Main Karoo Basin attests to a marine continental shelf depositional environment. Sediments of the Main Karoo Basin have high contents of tadpole-shaped pyrite in coal and non-coal strata as compared to sediments of the Sub-Basins. The observed pyrite is ascribed to early diagenetic origin, and is closely related to the generation of acid mining drainage. The sediments have experienced an involved sequence of diagenetic alterations. The alterations considered to be typical for sandstones in the Main Karoo Basin are calcite cementation, feldspar dissolution, kaolinite infilling, pyrite grain coatings, albitization and pressure solution; whereas, quartz overgrowth and clay matrix filling are characteristics of sediments of Sub-Basins. The sequence and distribution of these alterations are related to the source mineral composition, depositional environment, stratigraphic relationships and burial history of the sediments. A direct link exists among the depositional environments, the mineral assemblages and the geochemical compositions of the lithologies. SiO2 is the dominant major oxide and is abundant in coals from coalfields located in the Sub-Basins. Si, Al, Fe, Ca, S, Mg, K and Na show strong association with their discrete minerals. The sandstones are substantially enriched in elements that are chemically immobile and associated with terrigenous influx, such as SiO2, Al2O3, and TiO2. The observed high contents of SiO2 are probably due to source rocks and silicification. SiO2, Al2O3 and TiO2 are related to clay and heavy minerals, with elevated Fe2O3 (Total) content in sediments of the Main Karoo Basin ascribed to sulphidization. Sediments from the Main Karoo Basin are enriched in both Na2O and K2O due to albitization and muscovitization. Substantial concentrations of Ba, Rb and Zr are in accordance to the high amount of phyllosilicates and heavy minerals. Muscovitization contributes to the correlation of Rb and Ba with K2O. The shales are substantially depleted in SiO2, CaO, MgO, Na2O, K2O, TiO2 and Fe2O3 due to weathering and diagenetic alteration, but are enriched in Al2O3 and P2O5. The ABA test clearly indicates that sandstones from the Main Karoo Basin have a potential of generating AMD as they contain sufficient pyrite to generate acid, with the final pH values of the samples turning acidic upon complete oxidation of pyrite. On the contrary, sediments of SubBasins contain sufficient calcite that serves to limit the amount of acid generation. Both sandstone and coal from collieries representing the Main Karoo Basin are characterised by elevated contents of S percent in comparison to coal from collieries representing the Sub-Basins. In general, the quality of water is as a result of a combination of complex geochemical interactions that involves various ions from different sources. Water leaching test shows that the leachates have varied chemical compositions with pH values in the range of 4.5-9 for the sandstone, and 2– 8.9 for the coal leachates. Variations in the pH values are attributed to regional phenomena controlled by the mineralogical and hydrological environments. Furthermore, the variation in pH is ascribed to the presence of acid forming pyrite and acid neutralizing carbonate minerals that are highly reactive in the mining environment. Elements Na, Ca, Mg and K occur in non-compliant concentrations in both coal and non-coal leachates indicating their abundance in all of the lithologies. Na enrichment in the lithologies is associated with albite, clay minerals and Al-Ksulphate coatings. Elements Fe, Al, Cd and Pb are easily leached from the lithologies. According to the equilibrium model, gibbsite, cuprite, diaspore and boehmite are the supersaturated minerals in the lithologies. Influencing factors such as the mineralogical composition of rocks are reflected in the wide variation of pH, TDS, EC and the ion concentrations of the studied water samples. The pH of the studied areas is neutral to alkaline. High levels of TDS and EC are observed in the Brandspruit Colliery, which is due to dissolution of soluble salts from the rock sequence that the water passes through. The anion chemistry shows the dominance of SO4 2- in the surface and groundwater of Brandspruit, Vaalkrantz and Elitheni Collieries, whereas HCO3 - dominates in the Arnot Colliery. SO4 2- is ascribed to the oxidative weathering of pyrites. Cldominates in groundwater from the Arnot Colliery and the Waterberg Coalfield. The cation chemistry is dominated by Na+ in the surface and groundwater of the Brandspruit, Vaalkrantz and Elitheni Collieries. Mg2+ dominates in groundwater from the Arnot Colliery, while K+ dominates in the Waterberg Coalfield. Fe is highly enriched in water from the Brandspruit Colliery, and is linked to the oxidation of pyrite. Carbonates are the supersaturated minerals in the Sub-Basins whilst sulphates are supersaturated in the Main Karoo Basin. The research shows that variations in regional mineral distribution is a result of a palaeo-deposition environment that was of marine nature for the coal sequence in the Main Karoo Basin and of fresh water for the coal sequence in Sub-Basins. A direct link therefore exists between depositional environments, mineral assemblages and whole rock geochemistry. It can be concluded that AMD is directly linked to pyrite and other sulphides, the coal mines located in the Main Karoo Basin have the possibility to deteriorate surface- and ground-water quality and to generate AMD during the mining processes; coal miners need to seriously consider applying environmental protection measures when mining coal in the Main Karoo Basin. Whereas, coal mining in the Sub-Basins has low possibility of generating AMD and pollution. , Thesis (PhD) (Geology) -- University of Fort Hare, 2015
- Full Text:
- Date Issued: 2015
- Authors: Ncube, Lindani
- Date: 2015
- Subjects: Mine drainage--Environmental aspects--South Africa , Coal mines and mining--Environmental aspects--South Africa , Acid mine drainage--Environmental aspects--South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/19556 , vital:43139
- Description: The coal deposits have been and continue to be the primary source of energy in South Africa. The continuous use of coal presents many challenges that includes genesis of acid mine drainage (AMD) which is as a result of the oxidation of predominant pyrite (FeS2) and other sulphides. The aim of this study was to investigate the role of source rocks and their depositional environments on AMD generation in South African coal mine environments. Five collieries from five coalfields were selected as case studies: Brandspruit in the Highveld, Vaalkrantz in the Vryheid, the Elitheni in the Molteno-Indwe, the Arnot in the Witbank and the Malatleng Exploration Project in the Waterberg Coalfields. Brandspruit, Vaalkrantz and Elitheni Collieries are located in the Main Karoo Basin, while the Witbank and the Waterberg Coalfields are located in Sub-Basins. The study investigated a variety of indices such as palaeo-depositional environments, mineral assemblages, geochemical signatures, water quality parameters, acid base accounting (ABA) and water leach tests for the coal and associated non-coal strata. An effort was made to establish the relationship between the mineralogy of the studied lithologies and the associated water quality. The study resulted in delineation of detrital and diagenetic rock components and interpretation of source area of rock types and the origin and timing of diagenetic alterations. Sandstone units are prevalent, except in the Waterberg Coalfield where mudstones are prevalent. Classifications of the mineralogical composition with descriptive adjectives yield the rock names arkose to sub-arkose categories in the Main Karoo Basin, and sub-arenites to quartz arenites in the Sub-Basins with the sandstones of recycled origin. Further, the sandstones of the Main Karoo Basin are of mixed provenance whilst those of Sub-Basins represent cratonic interior provenance. Sandstone from the Main Karoo Basin generally exhibit high concentrations of feldspars, which favour either high relief, arid or arctic climates with less chemical weathering at the source area. The presence of glauconite in sediments of the Main Karoo Basin attests to a marine continental shelf depositional environment. Sediments of the Main Karoo Basin have high contents of tadpole-shaped pyrite in coal and non-coal strata as compared to sediments of the Sub-Basins. The observed pyrite is ascribed to early diagenetic origin, and is closely related to the generation of acid mining drainage. The sediments have experienced an involved sequence of diagenetic alterations. The alterations considered to be typical for sandstones in the Main Karoo Basin are calcite cementation, feldspar dissolution, kaolinite infilling, pyrite grain coatings, albitization and pressure solution; whereas, quartz overgrowth and clay matrix filling are characteristics of sediments of Sub-Basins. The sequence and distribution of these alterations are related to the source mineral composition, depositional environment, stratigraphic relationships and burial history of the sediments. A direct link exists among the depositional environments, the mineral assemblages and the geochemical compositions of the lithologies. SiO2 is the dominant major oxide and is abundant in coals from coalfields located in the Sub-Basins. Si, Al, Fe, Ca, S, Mg, K and Na show strong association with their discrete minerals. The sandstones are substantially enriched in elements that are chemically immobile and associated with terrigenous influx, such as SiO2, Al2O3, and TiO2. The observed high contents of SiO2 are probably due to source rocks and silicification. SiO2, Al2O3 and TiO2 are related to clay and heavy minerals, with elevated Fe2O3 (Total) content in sediments of the Main Karoo Basin ascribed to sulphidization. Sediments from the Main Karoo Basin are enriched in both Na2O and K2O due to albitization and muscovitization. Substantial concentrations of Ba, Rb and Zr are in accordance to the high amount of phyllosilicates and heavy minerals. Muscovitization contributes to the correlation of Rb and Ba with K2O. The shales are substantially depleted in SiO2, CaO, MgO, Na2O, K2O, TiO2 and Fe2O3 due to weathering and diagenetic alteration, but are enriched in Al2O3 and P2O5. The ABA test clearly indicates that sandstones from the Main Karoo Basin have a potential of generating AMD as they contain sufficient pyrite to generate acid, with the final pH values of the samples turning acidic upon complete oxidation of pyrite. On the contrary, sediments of SubBasins contain sufficient calcite that serves to limit the amount of acid generation. Both sandstone and coal from collieries representing the Main Karoo Basin are characterised by elevated contents of S percent in comparison to coal from collieries representing the Sub-Basins. In general, the quality of water is as a result of a combination of complex geochemical interactions that involves various ions from different sources. Water leaching test shows that the leachates have varied chemical compositions with pH values in the range of 4.5-9 for the sandstone, and 2– 8.9 for the coal leachates. Variations in the pH values are attributed to regional phenomena controlled by the mineralogical and hydrological environments. Furthermore, the variation in pH is ascribed to the presence of acid forming pyrite and acid neutralizing carbonate minerals that are highly reactive in the mining environment. Elements Na, Ca, Mg and K occur in non-compliant concentrations in both coal and non-coal leachates indicating their abundance in all of the lithologies. Na enrichment in the lithologies is associated with albite, clay minerals and Al-Ksulphate coatings. Elements Fe, Al, Cd and Pb are easily leached from the lithologies. According to the equilibrium model, gibbsite, cuprite, diaspore and boehmite are the supersaturated minerals in the lithologies. Influencing factors such as the mineralogical composition of rocks are reflected in the wide variation of pH, TDS, EC and the ion concentrations of the studied water samples. The pH of the studied areas is neutral to alkaline. High levels of TDS and EC are observed in the Brandspruit Colliery, which is due to dissolution of soluble salts from the rock sequence that the water passes through. The anion chemistry shows the dominance of SO4 2- in the surface and groundwater of Brandspruit, Vaalkrantz and Elitheni Collieries, whereas HCO3 - dominates in the Arnot Colliery. SO4 2- is ascribed to the oxidative weathering of pyrites. Cldominates in groundwater from the Arnot Colliery and the Waterberg Coalfield. The cation chemistry is dominated by Na+ in the surface and groundwater of the Brandspruit, Vaalkrantz and Elitheni Collieries. Mg2+ dominates in groundwater from the Arnot Colliery, while K+ dominates in the Waterberg Coalfield. Fe is highly enriched in water from the Brandspruit Colliery, and is linked to the oxidation of pyrite. Carbonates are the supersaturated minerals in the Sub-Basins whilst sulphates are supersaturated in the Main Karoo Basin. The research shows that variations in regional mineral distribution is a result of a palaeo-deposition environment that was of marine nature for the coal sequence in the Main Karoo Basin and of fresh water for the coal sequence in Sub-Basins. A direct link therefore exists between depositional environments, mineral assemblages and whole rock geochemistry. It can be concluded that AMD is directly linked to pyrite and other sulphides, the coal mines located in the Main Karoo Basin have the possibility to deteriorate surface- and ground-water quality and to generate AMD during the mining processes; coal miners need to seriously consider applying environmental protection measures when mining coal in the Main Karoo Basin. Whereas, coal mining in the Sub-Basins has low possibility of generating AMD and pollution. , Thesis (PhD) (Geology) -- University of Fort Hare, 2015
- Full Text:
- Date Issued: 2015
Antjie Krog and the post-apartheid public sphere: Speaking poetry to power
- Authors: Garman, Anthea
- Date: 2015
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/159913 , vital:40355 , ISBN 978-1869142933
- Description: Antjie Krog has been known in Afrikaans literary circles and the media for decades because of her poetry and her strong political convictions. Often known simply as 'Antjie,' she is also affectionately called 'our beloved poet' and our 'Joan of Arc' by Afrikaans commentators. It was through her work on the Truth and Reconciliation Commission as an SABC radio journalist and her subsequent book, Country of My Skull, that Antjie Krog then became known to English-speakers in South Africa and across the world. Her work catapulted her particular brand of poetics and politics, honed over many years of her opposition to apartheid, into the South African public sphere at a time when the country was not only looking for a humane and just resolution after the apartheid era, but was also establishing itself as a new democracy.
- Full Text:
- Date Issued: 2015
- Authors: Garman, Anthea
- Date: 2015
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/159913 , vital:40355 , ISBN 978-1869142933
- Description: Antjie Krog has been known in Afrikaans literary circles and the media for decades because of her poetry and her strong political convictions. Often known simply as 'Antjie,' she is also affectionately called 'our beloved poet' and our 'Joan of Arc' by Afrikaans commentators. It was through her work on the Truth and Reconciliation Commission as an SABC radio journalist and her subsequent book, Country of My Skull, that Antjie Krog then became known to English-speakers in South Africa and across the world. Her work catapulted her particular brand of poetics and politics, honed over many years of her opposition to apartheid, into the South African public sphere at a time when the country was not only looking for a humane and just resolution after the apartheid era, but was also establishing itself as a new democracy.
- Full Text:
- Date Issued: 2015
Anton and Vale van der Merwe: reinterpreting Afro-Oriental studio ceramics traditions in South Africa
- Authors: Steele, John
- Date: 2015
- Language: English
- Type: text , Article
- Identifier: http://hdl.handle.net/11260/968 , vital:30077
- Description: Growing awareness of ancient Chinese Song and Yuan ceramics, amongst other Oriental traditions, by people with western connections such as Bernard Leach and Michael Cardew, in conjunction with influences from Japanese associates such as Soyetsu Yanagi, Kenkichi Tomimoto, and Shoji Hamada, (De Waal 1997, Harrod 2012, Kikuchi 1977, Leach 1976) has had many consequences. It spread a consciousness idealizing self-sufficient pottery studios where potters were in touch with all aspects of creating utilityware, largely from local materials for local use. Out of this emerged an Anglo-Oriental studio ceramic philosophy of form and practice, associated mainly with hand-made high temperature reduction fired ceramics. These ideas spread to South Africa in the late 1950s, and by the early 1960s local studios were being established along these lines. This studio ceramics movement grew exponentially in South Africa, initiating a phase of Afro-Oriental ceramics that remains a powerful way of life and visual arts influence. This paper seeks to explore aspects of Afro- Oriental studio ceramics in South Africa, with particular reference to the Leach/Hamada/Cardew to Rabinowitz, and Van der Merwe lineage.
- Full Text:
- Date Issued: 2015
- Authors: Steele, John
- Date: 2015
- Language: English
- Type: text , Article
- Identifier: http://hdl.handle.net/11260/968 , vital:30077
- Description: Growing awareness of ancient Chinese Song and Yuan ceramics, amongst other Oriental traditions, by people with western connections such as Bernard Leach and Michael Cardew, in conjunction with influences from Japanese associates such as Soyetsu Yanagi, Kenkichi Tomimoto, and Shoji Hamada, (De Waal 1997, Harrod 2012, Kikuchi 1977, Leach 1976) has had many consequences. It spread a consciousness idealizing self-sufficient pottery studios where potters were in touch with all aspects of creating utilityware, largely from local materials for local use. Out of this emerged an Anglo-Oriental studio ceramic philosophy of form and practice, associated mainly with hand-made high temperature reduction fired ceramics. These ideas spread to South Africa in the late 1950s, and by the early 1960s local studios were being established along these lines. This studio ceramics movement grew exponentially in South Africa, initiating a phase of Afro-Oriental ceramics that remains a powerful way of life and visual arts influence. This paper seeks to explore aspects of Afro- Oriental studio ceramics in South Africa, with particular reference to the Leach/Hamada/Cardew to Rabinowitz, and Van der Merwe lineage.
- Full Text:
- Date Issued: 2015
Appraising the appraisal framework: evidence from Grahamstown property advertisements
- Authors: Beangstrom, Tracy
- Date: 2015
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/54744 , vital:26608
- Description: This thesis considers how interpersonal meaning choices in property advertisements are best reflected in a context of constraint in Grahamstown, South Africa, using and appraising Martin & White’s (2005) APPRAISAL Framework. The study is comparative in two senses since the data is analysed using Martin & White’s (2005) APPRAISAL Framework and a revision to it, and property advertisements from two competing estate agencies are analysed: Remax Frontier Properties and Pam Golding Properties. An initial strict application of Martin & White’s (2005) framework is followed by a second, based on analyst difficulties and framework limitations experienced in the first analysis, as well as those experienced by other researchers. Revisions to the original framework include added ‘local’, context-driven features and sub-categories: Exclusivity and Convenience in Attitude, a Scale of Intensity in Graduation, and a category ‘Invite’ in Engagement. These enable a richer, more detailed account of the alignment strategies and interpersonal micro-politics at play in the property advertisements than is possible using the original framework. Findings from the analyses reveal four facts of note. Firstly, that while the original Martin & White (2005) APPRAISAL Framework captures a general level of interpersonal meaning in the data, it does so more fully when it includes contextual and contextually-driven categories that are informed by local knowledge. Secondly, two levels of meaning are expressed in the data. One is aimed at an ‘external’ audience; the other, truer, fuller and more contentious, is aimed at what appears to be the intended audience only. Thirdly, and relatedly, specific contextual and cultural knowledge is needed by the intended audience to access the intended meaning. Fourthly, both estate agencies promote values of high prestige, exclusivity, elitism and wealth as their intended meaning to align a like-minded audience, although Remax Frontier Properties attribute these values to location and features of the home to a greater extent than Pam Golding Properties, who place greater emphasis on the size of the home. The thesis suggests further avenues for research into the discourse of property advertising, as well as into overcoming certain context-specific limitations of the APPRAISAL Framework.
- Full Text:
- Date Issued: 2015
- Authors: Beangstrom, Tracy
- Date: 2015
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/54744 , vital:26608
- Description: This thesis considers how interpersonal meaning choices in property advertisements are best reflected in a context of constraint in Grahamstown, South Africa, using and appraising Martin & White’s (2005) APPRAISAL Framework. The study is comparative in two senses since the data is analysed using Martin & White’s (2005) APPRAISAL Framework and a revision to it, and property advertisements from two competing estate agencies are analysed: Remax Frontier Properties and Pam Golding Properties. An initial strict application of Martin & White’s (2005) framework is followed by a second, based on analyst difficulties and framework limitations experienced in the first analysis, as well as those experienced by other researchers. Revisions to the original framework include added ‘local’, context-driven features and sub-categories: Exclusivity and Convenience in Attitude, a Scale of Intensity in Graduation, and a category ‘Invite’ in Engagement. These enable a richer, more detailed account of the alignment strategies and interpersonal micro-politics at play in the property advertisements than is possible using the original framework. Findings from the analyses reveal four facts of note. Firstly, that while the original Martin & White (2005) APPRAISAL Framework captures a general level of interpersonal meaning in the data, it does so more fully when it includes contextual and contextually-driven categories that are informed by local knowledge. Secondly, two levels of meaning are expressed in the data. One is aimed at an ‘external’ audience; the other, truer, fuller and more contentious, is aimed at what appears to be the intended audience only. Thirdly, and relatedly, specific contextual and cultural knowledge is needed by the intended audience to access the intended meaning. Fourthly, both estate agencies promote values of high prestige, exclusivity, elitism and wealth as their intended meaning to align a like-minded audience, although Remax Frontier Properties attribute these values to location and features of the home to a greater extent than Pam Golding Properties, who place greater emphasis on the size of the home. The thesis suggests further avenues for research into the discourse of property advertising, as well as into overcoming certain context-specific limitations of the APPRAISAL Framework.
- Full Text:
- Date Issued: 2015
Art investment as a portfolio diversification strategy in South Africa
- Botha, Ferdi, Scott, Brett, Snowball, Jeanette D
- Authors: Botha, Ferdi , Scott, Brett , Snowball, Jeanette D
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67422 , vital:29086
- Description: publisher version , Art has been suggested as a good way to diversify investment portfolios during times of financial uncertainty. The argument is that art exhibits different risk and return characteristics to conventional investments in other asset classes. The new Citadel Art Price index offered the opportunity to test this theory in the South African context. The Citadel index uses the hedonic regression method with observations drawn from the top 100, 50 and 20 artists by sales volume, giving approximately 29 503 total auction observations. The Index consists of quarterly data from the period 2000Q1 to 2013Q3. A VAR of the art price index, Johannesburg Stock Exchange all-share index, house price index, and South African government bond index were used. Flowing from the VAR results, additional analyses included variance decomposition, impulse response, and, to determine volatility, variance and standard deviation measures for each index. Results show that, when there are increased returns on the stock market in the previous period and wealth increases, there is a change in the Citadel Art Price Index in the same direction. This finding is consistent with Goetzmann et al. (2009), who reported that there is a strong relationship between art and equity markets and that art price changes are driven by capital gains and losses. No significant difference was found between the house price index and the art price index, and neither between the art and government bond price indices. Overall, the South African art market does not offer the opportunity to diversify portfolios dominated by either property, bonds, or shares.
- Full Text:
- Date Issued: 2015
- Authors: Botha, Ferdi , Scott, Brett , Snowball, Jeanette D
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67422 , vital:29086
- Description: publisher version , Art has been suggested as a good way to diversify investment portfolios during times of financial uncertainty. The argument is that art exhibits different risk and return characteristics to conventional investments in other asset classes. The new Citadel Art Price index offered the opportunity to test this theory in the South African context. The Citadel index uses the hedonic regression method with observations drawn from the top 100, 50 and 20 artists by sales volume, giving approximately 29 503 total auction observations. The Index consists of quarterly data from the period 2000Q1 to 2013Q3. A VAR of the art price index, Johannesburg Stock Exchange all-share index, house price index, and South African government bond index were used. Flowing from the VAR results, additional analyses included variance decomposition, impulse response, and, to determine volatility, variance and standard deviation measures for each index. Results show that, when there are increased returns on the stock market in the previous period and wealth increases, there is a change in the Citadel Art Price Index in the same direction. This finding is consistent with Goetzmann et al. (2009), who reported that there is a strong relationship between art and equity markets and that art price changes are driven by capital gains and losses. No significant difference was found between the house price index and the art price index, and neither between the art and government bond price indices. Overall, the South African art market does not offer the opportunity to diversify portfolios dominated by either property, bonds, or shares.
- Full Text:
- Date Issued: 2015
Aspects of the biology and life history of largespot pompano, Trachinotus botla, in South Africa
- Parker, Daniel, Booth, Anthony J
- Authors: Parker, Daniel , Booth, Anthony J
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123798 , vital:35499 , https://doi.10.1071/MF14029
- Description: Trachinotus botla is an important recreational surf zone-dependent fish species distributed in the Indo-west Pacific from South Africa to Australia. In South Africa it is restricted to the northern KwaZulu-Natal coast. Biological investigations revealed that it is a fast growing species that attains a maximum age of, 7 years. Males and females sexually matured in their third year. It has a protracted summer spawning season with evidence of serial spawning behaviour. T. botla is an opportunistic predator with a generalist diet, with fish feeding on a wide variety of prey items particularly those that are temporally ‘superabundant’. Small fish fed predominantly on copepods and terrestrial insects, whereas larger fish consumed bivalves and crabs. Teleosts, primarily engraulids, were important components to the diet of fish of all sizes. An ontogenetic dietary shift was observed just after sexual maturity (300-mm fork length) that is possibly linked to a change in habitat preference with larger fish foraging on deeper reefs.
- Full Text:
- Date Issued: 2015
- Authors: Parker, Daniel , Booth, Anthony J
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123798 , vital:35499 , https://doi.10.1071/MF14029
- Description: Trachinotus botla is an important recreational surf zone-dependent fish species distributed in the Indo-west Pacific from South Africa to Australia. In South Africa it is restricted to the northern KwaZulu-Natal coast. Biological investigations revealed that it is a fast growing species that attains a maximum age of, 7 years. Males and females sexually matured in their third year. It has a protracted summer spawning season with evidence of serial spawning behaviour. T. botla is an opportunistic predator with a generalist diet, with fish feeding on a wide variety of prey items particularly those that are temporally ‘superabundant’. Small fish fed predominantly on copepods and terrestrial insects, whereas larger fish consumed bivalves and crabs. Teleosts, primarily engraulids, were important components to the diet of fish of all sizes. An ontogenetic dietary shift was observed just after sexual maturity (300-mm fork length) that is possibly linked to a change in habitat preference with larger fish foraging on deeper reefs.
- Full Text:
- Date Issued: 2015
Assessing public administration implications of the use and disposal of agro-chemicals in A2 farms in Zimbabwe : a case study of Chirumhanzu District
- Authors: Matunhu, Viola
- Date: 2015
- Subjects: Agricultural chemicals , Hazardous waste treatment facilities , Pesticide waste
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/26481 , vital:65471
- Description: This study is concerned with use and disposal of agro-chemical in A2 farms in Zimbabwe with specific reference to Chirumhanzu District. The study is located in the field of public administration. A transformational mixed research design was employed in the collection, analysis and interpretation of the field data. The study involved farm employees in 21 A2 farms that use agro-chemicals to enhance farm productivity. Non probability sampling techniques were employed to select the participating farms. Interviews, questionnaires, literature search, and observation where the main data collection instruments. A total of 150 purposively selected employees drawn from 21 participating farms participated in the study. The findings of this empirical study, which uses the terms I, the researcher, and the study interchangeably, were that there is poor use and management of agro-chemicals in the area. Most farm employees do not adhere to instructions on use and disposal of the chemicals and there is a weak monitoring and evaluation of the use and disposal of agro-chemicals on the farms. Yet, most of these chemicals are carcinogens. Farm employees need to be trained on personal and public health implications of poor management of agro-chemicals. Labels on containers that store chemicals need to be written in both English and vernacular, which is not the case in the district. Labels on most of the chemicals on the farms studied are written in English and technical terms are used. Although, most of the employees on the farms are literate, they find it difficult to understand the jargon on labels. , Thesis (PhD) -- Faculty of Management and Commerce, 2015
- Full Text:
- Date Issued: 2015
- Authors: Matunhu, Viola
- Date: 2015
- Subjects: Agricultural chemicals , Hazardous waste treatment facilities , Pesticide waste
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/26481 , vital:65471
- Description: This study is concerned with use and disposal of agro-chemical in A2 farms in Zimbabwe with specific reference to Chirumhanzu District. The study is located in the field of public administration. A transformational mixed research design was employed in the collection, analysis and interpretation of the field data. The study involved farm employees in 21 A2 farms that use agro-chemicals to enhance farm productivity. Non probability sampling techniques were employed to select the participating farms. Interviews, questionnaires, literature search, and observation where the main data collection instruments. A total of 150 purposively selected employees drawn from 21 participating farms participated in the study. The findings of this empirical study, which uses the terms I, the researcher, and the study interchangeably, were that there is poor use and management of agro-chemicals in the area. Most farm employees do not adhere to instructions on use and disposal of the chemicals and there is a weak monitoring and evaluation of the use and disposal of agro-chemicals on the farms. Yet, most of these chemicals are carcinogens. Farm employees need to be trained on personal and public health implications of poor management of agro-chemicals. Labels on containers that store chemicals need to be written in both English and vernacular, which is not the case in the district. Labels on most of the chemicals on the farms studied are written in English and technical terms are used. Although, most of the employees on the farms are literate, they find it difficult to understand the jargon on labels. , Thesis (PhD) -- Faculty of Management and Commerce, 2015
- Full Text:
- Date Issued: 2015
Assessment in higher education: reframing traditional understandings and practices
- Clarence, Sherran, Quinn, Lynn, Vorster, Jo-Anne
- Authors: Clarence, Sherran , Quinn, Lynn , Vorster, Jo-Anne
- Date: 2015
- Language: English
- Type: Book , text
- Identifier: http://hdl.handle.net/10962/59534 , vital:27624
- Description: The case studies in this publication provide examples of lecturers who have considered the role of assessment in their courses carefully. All of them have engaged with matters related to assessment as part of the formal courses or qualifications offered by staff of the Centre for Higher Education Research, Teaching and Learning (CHERTL) at Rhodes University. In these courses lecturers are encouraged to reflect critically on their current assessment practices, engage with some of the literature and research on assessment in higher education, and then re-conceptualise their assessment methods and approaches. These case studies were drawn from the assignments and portfolios that they completed as part of the summative assessment for the courses they attended. The purpose of the case studies is pedagogic and to illustrate a range of assessment practices and principles. For the sake of clarity some of the details have been omitted or slightly changed.
- Full Text:
- Date Issued: 2015
- Authors: Clarence, Sherran , Quinn, Lynn , Vorster, Jo-Anne
- Date: 2015
- Language: English
- Type: Book , text
- Identifier: http://hdl.handle.net/10962/59534 , vital:27624
- Description: The case studies in this publication provide examples of lecturers who have considered the role of assessment in their courses carefully. All of them have engaged with matters related to assessment as part of the formal courses or qualifications offered by staff of the Centre for Higher Education Research, Teaching and Learning (CHERTL) at Rhodes University. In these courses lecturers are encouraged to reflect critically on their current assessment practices, engage with some of the literature and research on assessment in higher education, and then re-conceptualise their assessment methods and approaches. These case studies were drawn from the assignments and portfolios that they completed as part of the summative assessment for the courses they attended. The purpose of the case studies is pedagogic and to illustrate a range of assessment practices and principles. For the sake of clarity some of the details have been omitted or slightly changed.
- Full Text:
- Date Issued: 2015
Assessment of the spatial and temporal variations in periphyton communities along a small temperate river system: A multimetric and stable isotope analysis approach
- Dalu, Tatenda, Bere, Taurai, Richoux, Nicole B, Froneman, P William
- Authors: Dalu, Tatenda , Bere, Taurai , Richoux, Nicole B , Froneman, P William
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124249 , vital:35580 , https://doi.org/10.1016/j.sajb.2015.05.028
- Description: Periphyton community structure and stable isotope values have been identified as potential indicators of anthropogenic nitrogen pollution, an increasingly important challenge in aquatic systems. The aim of the study was to assess the spatio-temporal changes in periphyton characteristics to identify potential anthropogenic nitrogen pollution sources such as agricultural and sewage discharge within the Kowie River catchment, South Africa. Periphyton was collected once a season from five sites between September 2012 and May 2013. Diversity indices, multimetric and stable isotope analyses were employed for describing the spatial and temporal dynamics of periphyton community assemblages. Water depth, salinity, resistivity, oxygen reduction potential, nitrates, water velocity and conductivity were the major factors affecting periphyton community structure. Eighty-seven periphyton taxa belonging to 43 genera were recorded throughout the study sites and periods. Periphyton species richness, abundance and stable isotope signatures differed significantly among sites but not among seasons. The lower sections of the Kowie River were polluted by anthropogenic sources as indicated by the high periphytic isotopic nitrogen values (7.9–15.2‰) compared to the pristine upstream sites (4–8‰). We recommend that researchers use a combination of community structure and stable isotope measurements to monitor the periphyton in lotic systems.
- Full Text:
- Date Issued: 2015
- Authors: Dalu, Tatenda , Bere, Taurai , Richoux, Nicole B , Froneman, P William
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124249 , vital:35580 , https://doi.org/10.1016/j.sajb.2015.05.028
- Description: Periphyton community structure and stable isotope values have been identified as potential indicators of anthropogenic nitrogen pollution, an increasingly important challenge in aquatic systems. The aim of the study was to assess the spatio-temporal changes in periphyton characteristics to identify potential anthropogenic nitrogen pollution sources such as agricultural and sewage discharge within the Kowie River catchment, South Africa. Periphyton was collected once a season from five sites between September 2012 and May 2013. Diversity indices, multimetric and stable isotope analyses were employed for describing the spatial and temporal dynamics of periphyton community assemblages. Water depth, salinity, resistivity, oxygen reduction potential, nitrates, water velocity and conductivity were the major factors affecting periphyton community structure. Eighty-seven periphyton taxa belonging to 43 genera were recorded throughout the study sites and periods. Periphyton species richness, abundance and stable isotope signatures differed significantly among sites but not among seasons. The lower sections of the Kowie River were polluted by anthropogenic sources as indicated by the high periphytic isotopic nitrogen values (7.9–15.2‰) compared to the pristine upstream sites (4–8‰). We recommend that researchers use a combination of community structure and stable isotope measurements to monitor the periphyton in lotic systems.
- Full Text:
- Date Issued: 2015
Azawan: precolonial musical culture and Saharawi nationalism in the refugee camps of the Hamada Desert in Algeria
- Authors: Amoros, Luis Gimenez
- Date: 2015
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/59710 , vital:27641 , http://dx.doi.org/10.21504/amj.v10i1.1225
- Description: This article analyses Saharawi music as performed for the refugee community in the camps. I argue that the construction and evolution of Saharawi music in the camps is divided into two main areas: nationalism in relation to the decolonisation of Western Sahara, and maintenance of cultural values in Saharawi music found in the historical retention of the Haul modal system originating in precolonial Saharawi culture. Local audiences use the term Azawan to define the combination of nationalist sentiments and retention of their precolonial musical culture in Saharawi music.
- Full Text:
- Date Issued: 2015
- Authors: Amoros, Luis Gimenez
- Date: 2015
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/59710 , vital:27641 , http://dx.doi.org/10.21504/amj.v10i1.1225
- Description: This article analyses Saharawi music as performed for the refugee community in the camps. I argue that the construction and evolution of Saharawi music in the camps is divided into two main areas: nationalism in relation to the decolonisation of Western Sahara, and maintenance of cultural values in Saharawi music found in the historical retention of the Haul modal system originating in precolonial Saharawi culture. Local audiences use the term Azawan to define the combination of nationalist sentiments and retention of their precolonial musical culture in Saharawi music.
- Full Text:
- Date Issued: 2015
Bacterial degradation of fossil fuel waste in aqueous and solid media
- Authors: Edeki, Oghenekume Gerald
- Date: 2015
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/54565 , vital:26588
- Description: The generation of environmental pollutants worldwide is mainly due to over reliance on fossil fuels as a source of energy. As a result of the negative impacts of these pollutants on the health of humans, animals, plants and microorganisms, global attention has been directed towards ways of containing this problem. Biodegradation of fossil fuel is one of the most effective methods used to remediate contaminated systems. However with regard to coal waste, much of what is known is based on the ability of fungal species to biosolubilize this material under enrichment conditions in a laboratory setting. For effective biodegradation as a remediation technique, there is an immediate need to source, isolate, enrich and incorporate other microorganisms such as bacteria into bioremediation technologies. The goal of this dissertation was to isolate bacteria from fossil fuel contaminated environments and to demonstrate competence for petroleum hydrocarbon degradation which was achieved using a combination of analytical methods such as spectrophotometry, FT-IR, SEM and GC-MS. Screening for biodegradation of coal and petroleum hydrocarbon waste resulted in the isolation of 75 bacterial strains of which 15 showed good potential for use in developing remedial biotechnologies. Spectrophotometric analysis of bacteria both in coal and petroleum hydrocarbons (all in aqueous media) revealed a high proliferation of bacteria in these media suggesting that these microbes can effectively utilize the various substrates as a source of carbon. The isolated bacteria effectively degraded and converted waste coal to humic and fulvic acids; products required to enrich coal mine dumps to support re-vegetation. Scanning electron microscopy showed the attachment of bacteria to waste coal surfaces and the disintegration of coal structures while FT-IR analysis of extracted humic-like substances from biodegraded waste coal revealed these to have the same functional groups as commercial humic acid. Specific consortia which were established using the isolated bacterial strains, showed greater potential to biodegrade coal than did individual isolates. This was evident in experiments carried out on coal and hydrocarbons where the efficient colonization and utilization of these substrates by each bacterial consortium was observed due to the effect of added nutrients such as algae. The biodegradation of liquid petroleum hydrocarbons (diesel and BTEX) was also achieved using the 15 bacterial isolates. GC-MS analysis of extracted residual PHC from aqueous and solid media revealed rapid breakdown of these contaminants by bacteria. Different bacterial consortia established from the individual isolates were shown to be more efficient than single isolates indicating that formulated consortia are the biocatalysts of choice for fossil fuel biodegradation. This study represents one of the most detailed screenings for bacteria from fossil fuel contaminated sites and the isolation of strains with potential to biodegrade coal and petroleum hydrocarbon wastes. Several consortia have been developed and these show potential for further development as biocatalysts for use in bioremediation technology development. An evaluation of efficiency of each established bacterial consortium for biodegradation in a commercial and/or industrial setting at pilot scale is now needed.
- Full Text:
- Date Issued: 2015
- Authors: Edeki, Oghenekume Gerald
- Date: 2015
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/54565 , vital:26588
- Description: The generation of environmental pollutants worldwide is mainly due to over reliance on fossil fuels as a source of energy. As a result of the negative impacts of these pollutants on the health of humans, animals, plants and microorganisms, global attention has been directed towards ways of containing this problem. Biodegradation of fossil fuel is one of the most effective methods used to remediate contaminated systems. However with regard to coal waste, much of what is known is based on the ability of fungal species to biosolubilize this material under enrichment conditions in a laboratory setting. For effective biodegradation as a remediation technique, there is an immediate need to source, isolate, enrich and incorporate other microorganisms such as bacteria into bioremediation technologies. The goal of this dissertation was to isolate bacteria from fossil fuel contaminated environments and to demonstrate competence for petroleum hydrocarbon degradation which was achieved using a combination of analytical methods such as spectrophotometry, FT-IR, SEM and GC-MS. Screening for biodegradation of coal and petroleum hydrocarbon waste resulted in the isolation of 75 bacterial strains of which 15 showed good potential for use in developing remedial biotechnologies. Spectrophotometric analysis of bacteria both in coal and petroleum hydrocarbons (all in aqueous media) revealed a high proliferation of bacteria in these media suggesting that these microbes can effectively utilize the various substrates as a source of carbon. The isolated bacteria effectively degraded and converted waste coal to humic and fulvic acids; products required to enrich coal mine dumps to support re-vegetation. Scanning electron microscopy showed the attachment of bacteria to waste coal surfaces and the disintegration of coal structures while FT-IR analysis of extracted humic-like substances from biodegraded waste coal revealed these to have the same functional groups as commercial humic acid. Specific consortia which were established using the isolated bacterial strains, showed greater potential to biodegrade coal than did individual isolates. This was evident in experiments carried out on coal and hydrocarbons where the efficient colonization and utilization of these substrates by each bacterial consortium was observed due to the effect of added nutrients such as algae. The biodegradation of liquid petroleum hydrocarbons (diesel and BTEX) was also achieved using the 15 bacterial isolates. GC-MS analysis of extracted residual PHC from aqueous and solid media revealed rapid breakdown of these contaminants by bacteria. Different bacterial consortia established from the individual isolates were shown to be more efficient than single isolates indicating that formulated consortia are the biocatalysts of choice for fossil fuel biodegradation. This study represents one of the most detailed screenings for bacteria from fossil fuel contaminated sites and the isolation of strains with potential to biodegrade coal and petroleum hydrocarbon wastes. Several consortia have been developed and these show potential for further development as biocatalysts for use in bioremediation technology development. An evaluation of efficiency of each established bacterial consortium for biodegradation in a commercial and/or industrial setting at pilot scale is now needed.
- Full Text:
- Date Issued: 2015
Baculovirus-based strategies for the management of insect pests: a focus on development and application in South Africa
- Knox, Caroline M, Moore, Sean D, Luke, Garry, Hill, Martin P
- Authors: Knox, Caroline M , Moore, Sean D , Luke, Garry , Hill, Martin P
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/416829 , vital:71389 , xlink:href="https://doi.org/10.1080/09583157.2014.949222"
- Description: There is growing concern among governments, scientists, agricultural practitioners and the general public regarding the negative implications of widespread synthetic chemical pesticide application for the control of crop pests. As a result, baculovirus biopesticides are gaining popularity as components of integrated pest management (IPM) programmes in many countries despite several disadvantages related to slow speed of kill, limited host range and complex large scale production. In South Africa, baculoviruses are incorporated into IPM programmes for the control of crop pests in the field, and recent bioprospecting has led to the characterisation of several novel isolates with the potential to be formulated as commercial products. This contribution will provide an overview of the use of baculoviruses against insect pests in South Africa, as well as research and development efforts aimed at broadening their application as biocontrol agents. Challenges faced by researchers in developmental projects as well as potential users of baculoviruses as biopesticides in the field are also discussed.
- Full Text:
- Date Issued: 2015
- Authors: Knox, Caroline M , Moore, Sean D , Luke, Garry , Hill, Martin P
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/416829 , vital:71389 , xlink:href="https://doi.org/10.1080/09583157.2014.949222"
- Description: There is growing concern among governments, scientists, agricultural practitioners and the general public regarding the negative implications of widespread synthetic chemical pesticide application for the control of crop pests. As a result, baculovirus biopesticides are gaining popularity as components of integrated pest management (IPM) programmes in many countries despite several disadvantages related to slow speed of kill, limited host range and complex large scale production. In South Africa, baculoviruses are incorporated into IPM programmes for the control of crop pests in the field, and recent bioprospecting has led to the characterisation of several novel isolates with the potential to be formulated as commercial products. This contribution will provide an overview of the use of baculoviruses against insect pests in South Africa, as well as research and development efforts aimed at broadening their application as biocontrol agents. Challenges faced by researchers in developmental projects as well as potential users of baculoviruses as biopesticides in the field are also discussed.
- Full Text:
- Date Issued: 2015
Beauveria and Metarhizium against false codling moth (Lepidoptera: Tortricidae): a step towards selecting isolates for potential development of a mycoinsecticide
- Coombes, Candice A, Hill, Martin P, Moore, Sean D, Dames, Joanna F, Fullard, T
- Authors: Coombes, Candice A , Hill, Martin P , Moore, Sean D , Dames, Joanna F , Fullard, T
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/405757 , vital:70203 , xlink:href="https://hdl.handle.net/10520/EJC167505"
- Description: False codling moth, Thaumatotibia leucotreta Meyrick (1912) (Lepidoptera: Tortricidae), can cause both pre- and post-harvest damage to citrus fruit. Not only can this result in reduced crop yield, but more importantly because of the moth's endemism to sub-Saharan Africa, it is classified as a phytosanitary pest by many export markets. An entire consignment of citrus may be rejected in the presence of a single moth (Moore 2012). Since the bulk of citrus fruit production in South Africa is exported, the control of T. leucotreta is critical (Citrus Growers Association, South Africa 2012). Traditionally, control has been achieved through the use of chemical insecticides; however, residue restrictions, resistance development and concerns about environmental pollution have substantially reduced the dependence on chemical pesticides in citrus. Research on T. leucotreta control has therefore focused on the use of biological organisms (e.g. parasitoids and viruses), which are used as control agents within an integrated pest management (IPM) programme in citrus. These biological control agents, however, only targeted the aboveground life stages of the pest, not the soil-dwelling life stages (late fifth instars, prepupae, pupae), which is the subject of this contribution (Moore 2012).
- Full Text:
- Date Issued: 2015
- Authors: Coombes, Candice A , Hill, Martin P , Moore, Sean D , Dames, Joanna F , Fullard, T
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/405757 , vital:70203 , xlink:href="https://hdl.handle.net/10520/EJC167505"
- Description: False codling moth, Thaumatotibia leucotreta Meyrick (1912) (Lepidoptera: Tortricidae), can cause both pre- and post-harvest damage to citrus fruit. Not only can this result in reduced crop yield, but more importantly because of the moth's endemism to sub-Saharan Africa, it is classified as a phytosanitary pest by many export markets. An entire consignment of citrus may be rejected in the presence of a single moth (Moore 2012). Since the bulk of citrus fruit production in South Africa is exported, the control of T. leucotreta is critical (Citrus Growers Association, South Africa 2012). Traditionally, control has been achieved through the use of chemical insecticides; however, residue restrictions, resistance development and concerns about environmental pollution have substantially reduced the dependence on chemical pesticides in citrus. Research on T. leucotreta control has therefore focused on the use of biological organisms (e.g. parasitoids and viruses), which are used as control agents within an integrated pest management (IPM) programme in citrus. These biological control agents, however, only targeted the aboveground life stages of the pest, not the soil-dwelling life stages (late fifth instars, prepupae, pupae), which is the subject of this contribution (Moore 2012).
- Full Text:
- Date Issued: 2015
Being a Born Free: the misunderstandings and missed opportunities facing young South Africans
- Authors: Malila, Vanessa
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/158680 , vital:40220 , https://hdl.handle.net/10520/EJC175765
- Description: Young South Africans are often referred to as the Born Frees - a term which sometimes means people born after 1994, sometimes people born after 1990, or young people who came of age politically after 1994. I've come to really dislike the term Born Frees and particularly the way it is used by the media and the politicians. By calling young people Born Frees, society is using apartheid as a reference point to identify a post-apartheid generation. This reference point (the transition to a 'free' society) unfortunately does not resonate with many of the young people that I've encountered in my research and many feel insulted by the implications of this term, which does not apply to them in any way. Should South African society really be using the transition from apartheid to define its young people and how does it relate to the lives of real young people in South Africa today? Are they really Born Free, free from what, free to do what, free individuals or free as a collective? I will look at some of the stereotypes being used in the mainstream media of Born Frees, and then look at the reaction to this term by some real young South Africans.
- Full Text:
- Date Issued: 2015
- Authors: Malila, Vanessa
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/158680 , vital:40220 , https://hdl.handle.net/10520/EJC175765
- Description: Young South Africans are often referred to as the Born Frees - a term which sometimes means people born after 1994, sometimes people born after 1990, or young people who came of age politically after 1994. I've come to really dislike the term Born Frees and particularly the way it is used by the media and the politicians. By calling young people Born Frees, society is using apartheid as a reference point to identify a post-apartheid generation. This reference point (the transition to a 'free' society) unfortunately does not resonate with many of the young people that I've encountered in my research and many feel insulted by the implications of this term, which does not apply to them in any way. Should South African society really be using the transition from apartheid to define its young people and how does it relate to the lives of real young people in South Africa today? Are they really Born Free, free from what, free to do what, free individuals or free as a collective? I will look at some of the stereotypes being used in the mainstream media of Born Frees, and then look at the reaction to this term by some real young South Africans.
- Full Text:
- Date Issued: 2015
Being at Home: Race, Institutional Culture and Transformation at South African Higher Education Institutions
- Tabensky, Pedro, Matthews, Sally
- Authors: Tabensky, Pedro , Matthews, Sally
- Date: 2015
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/142084 , vital:38048 , ISBN 9781869142902 , https://books.google.co.za/books?id=49o8rgEACAAJanddq=Being+at+home:+Race,+institutional+culture+and+transformation+at+South+African+higher+education+institutionandhl=enandsa=Xandved=0ahUKEwiPgsa6mpjjAhXNN8AKHbNwAtoQ6AEIKDAA
- Description: This edited work has gathered together contributions on how to transform universities in South Africa; as many are struggling to shift their institutional culture. In a South African context, transformation means to attempt to change higher education institutions such that they no longer reflect the values promoted by apartheid but rather reflect the values embodied in South Africa's 1996 Constitution. Institutional culture is the main subject for discussion in this book. In order to transform South Africa's universities, the contributors begin by analyzing the idea of what a university is, and relatedly, what its ideal aims are. A second theme is to understand what institutional culture is and how it functions. Moreover, transformation cannot occur without transforming the broader cultures of which they are a part. Related to this theme is a general concern about how contemporary moves towards the instrumentalization of higher education affect the ability to transform institutions. These institutions are being pushed to conform to goals that are outside the traditional idea of a university, such as concerns that universities are being 'bureaucratized' and becoming corporations, instead of a place of learning open to all. In conclusion it can be said that the contemporary South African academic community has an opportunity to recreate itself as the end of apartheid created space for engaging in transformative epistemic projects. The transformation of the tertiary sector entails a transformation of institutional cultures.
- Full Text:
- Date Issued: 2015
- Authors: Tabensky, Pedro , Matthews, Sally
- Date: 2015
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/142084 , vital:38048 , ISBN 9781869142902 , https://books.google.co.za/books?id=49o8rgEACAAJanddq=Being+at+home:+Race,+institutional+culture+and+transformation+at+South+African+higher+education+institutionandhl=enandsa=Xandved=0ahUKEwiPgsa6mpjjAhXNN8AKHbNwAtoQ6AEIKDAA
- Description: This edited work has gathered together contributions on how to transform universities in South Africa; as many are struggling to shift their institutional culture. In a South African context, transformation means to attempt to change higher education institutions such that they no longer reflect the values promoted by apartheid but rather reflect the values embodied in South Africa's 1996 Constitution. Institutional culture is the main subject for discussion in this book. In order to transform South Africa's universities, the contributors begin by analyzing the idea of what a university is, and relatedly, what its ideal aims are. A second theme is to understand what institutional culture is and how it functions. Moreover, transformation cannot occur without transforming the broader cultures of which they are a part. Related to this theme is a general concern about how contemporary moves towards the instrumentalization of higher education affect the ability to transform institutions. These institutions are being pushed to conform to goals that are outside the traditional idea of a university, such as concerns that universities are being 'bureaucratized' and becoming corporations, instead of a place of learning open to all. In conclusion it can be said that the contemporary South African academic community has an opportunity to recreate itself as the end of apartheid created space for engaging in transformative epistemic projects. The transformation of the tertiary sector entails a transformation of institutional cultures.
- Full Text:
- Date Issued: 2015
Biotechnology from bench to market: the design, scale-up and commercialisation strategy development of a disruptive bioprocess for potable ethanol production
- Authors: Dhanani, Karim Colin Hassan
- Date: 2015
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/55863 , vital:26750
- Description: The capacity of research institutions to engage in technology transfer activities has important implications on both economic development and technological advancement. This thesis explores the developmental and commercialisation processes involved in the transfer of a potentially disruptive bioprocessing technology for beverage alcohol production. Ethanolic fermentation strategies are of interest due to their global economic importance and their potential to produce clean renewable fuels in the future. Currently used methods are both energetically wasteful and economically inefficient. To this end more effective bioprocessing methods and implementation strategies are required to enable commercially viable decentralised small-scale ethanol production. Perfusion reactors have a number of advantages over batch and other continuous fermentation strategies. This study aimed to develop and study the fermentative efficiency of a perfusion tower bioreactor system at the bench scale, and subsequently through a scale up process to a low level commercial capacity. An HPLC method was developed for the Simultaneous quantification of common fermentation analytes; this was used to determine bench scale fermentation efficacies over an operational period. At steady state the ethanol volumetric productivity of the bench scale bioreactor system was 3.40 g. L-1.h-1, the average yield of ethanol to consumed sugar was 0.467 g.g -1, with an average sugar conversion percentage of 96%. Results showed that the tower perfusion bioreactor was appropriate for high performance ethyl alcohol fermentations. This reactor design was then scaled up to pilot scale and then commercial scale ca pacity. Similar efficienCies were achieved with these larger systems. Based on the process performance data obtained, a commercialisation strategy was developed and market performance was projected. It was found that productivity rates per unit volume were favourable, and the bioreactor system was determined to be very cost effective for a decentralised ethanolic beverage manufacturing model.
- Full Text:
- Date Issued: 2015
- Authors: Dhanani, Karim Colin Hassan
- Date: 2015
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/55863 , vital:26750
- Description: The capacity of research institutions to engage in technology transfer activities has important implications on both economic development and technological advancement. This thesis explores the developmental and commercialisation processes involved in the transfer of a potentially disruptive bioprocessing technology for beverage alcohol production. Ethanolic fermentation strategies are of interest due to their global economic importance and their potential to produce clean renewable fuels in the future. Currently used methods are both energetically wasteful and economically inefficient. To this end more effective bioprocessing methods and implementation strategies are required to enable commercially viable decentralised small-scale ethanol production. Perfusion reactors have a number of advantages over batch and other continuous fermentation strategies. This study aimed to develop and study the fermentative efficiency of a perfusion tower bioreactor system at the bench scale, and subsequently through a scale up process to a low level commercial capacity. An HPLC method was developed for the Simultaneous quantification of common fermentation analytes; this was used to determine bench scale fermentation efficacies over an operational period. At steady state the ethanol volumetric productivity of the bench scale bioreactor system was 3.40 g. L-1.h-1, the average yield of ethanol to consumed sugar was 0.467 g.g -1, with an average sugar conversion percentage of 96%. Results showed that the tower perfusion bioreactor was appropriate for high performance ethyl alcohol fermentations. This reactor design was then scaled up to pilot scale and then commercial scale ca pacity. Similar efficienCies were achieved with these larger systems. Based on the process performance data obtained, a commercialisation strategy was developed and market performance was projected. It was found that productivity rates per unit volume were favourable, and the bioreactor system was determined to be very cost effective for a decentralised ethanolic beverage manufacturing model.
- Full Text:
- Date Issued: 2015