Synthesis and characterization of Na(Y,Gd)F4 upconversion nanoparticles and an investigation of their effects on the photophysical properties of an unsubstituted tetrathiophenoxy phthalocyanine
- Taylor, Jessica M, Litwinski, Christian, Nyokong, Tebello, Antunes, Edith M
- Authors: Taylor, Jessica M , Litwinski, Christian , Nyokong, Tebello , Antunes, Edith M
- Language: English
- Type: Article
- Identifier: vital:7253 , http://hdl.handle.net/10962/d1020261
- Description: Sphere- and star-shaped Na(Y,Gd)F4:Yb/Er(Tm)upconversion nanoparticles (UCNP) were successfully synthesized utilizing a methanol-assisted thermal decomposition approach and their spectroscopic (absorption, emission and luminescence lifetime) properties fully characterized. The factors affecting the size and shape of the UCNPs were studied and discussed in detail. The size of the nanoparticles was determined using TEM primarily and found to be approximately 19 and 30 nm for the Er and Tm spheres, respectively, while the Er and Tm “stars” were found to be much larger with sizes ranging from 110 to 240 nm, respectively (as determined along the width of the nanoparticle). In addition, their influence on the spectroscopic properties of an unsubstituted tetrathiophenoxy phthalocyanine (H2Pc) was investigated. The UCNP were found to produce characteristic upconversion luminescence emissions in the blue, green, red and NIR regions. Simple mixing with an H2Pc in toluene was found to exert no obvious changes in the spectroscopic properties of the Pc, although a considerable increase in the radiative lifetimes is observed for the Pc in the presence of the UCNPs. The singlet oxygen generation mediated by the red light excitation of the H2Pc mixed with UCNP was found to decrease in the presence of the NPs. , Original publication is available at http://dx.doi.org/10.1007/s11051-015-2889-5
- Full Text: false
- Authors: Taylor, Jessica M , Litwinski, Christian , Nyokong, Tebello , Antunes, Edith M
- Language: English
- Type: Article
- Identifier: vital:7253 , http://hdl.handle.net/10962/d1020261
- Description: Sphere- and star-shaped Na(Y,Gd)F4:Yb/Er(Tm)upconversion nanoparticles (UCNP) were successfully synthesized utilizing a methanol-assisted thermal decomposition approach and their spectroscopic (absorption, emission and luminescence lifetime) properties fully characterized. The factors affecting the size and shape of the UCNPs were studied and discussed in detail. The size of the nanoparticles was determined using TEM primarily and found to be approximately 19 and 30 nm for the Er and Tm spheres, respectively, while the Er and Tm “stars” were found to be much larger with sizes ranging from 110 to 240 nm, respectively (as determined along the width of the nanoparticle). In addition, their influence on the spectroscopic properties of an unsubstituted tetrathiophenoxy phthalocyanine (H2Pc) was investigated. The UCNP were found to produce characteristic upconversion luminescence emissions in the blue, green, red and NIR regions. Simple mixing with an H2Pc in toluene was found to exert no obvious changes in the spectroscopic properties of the Pc, although a considerable increase in the radiative lifetimes is observed for the Pc in the presence of the UCNPs. The singlet oxygen generation mediated by the red light excitation of the H2Pc mixed with UCNP was found to decrease in the presence of the NPs. , Original publication is available at http://dx.doi.org/10.1007/s11051-015-2889-5
- Full Text: false
uMqathi talking about how times have changed
- uMqathi
- Authors: uMqathi
- Date: 2015
- Subjects: UNCATALOGUED
- Type: Video
- Identifier: http://hdl.handle.net/10962/303681 , vital:58361 , KHV-268
- Description: Elderly man talking about how times have changed , Use of this resource is governed by the terms and conditions of the Creative Commons "Attribution-NonCommercial-ShareAlike" License (http://creativecommons.org/licenses/by-nc-sa/2.0/) (NEVER CAHNGE THIS FIELD)
- Full Text: false
- Date Issued: 2015
- Authors: uMqathi
- Date: 2015
- Subjects: UNCATALOGUED
- Type: Video
- Identifier: http://hdl.handle.net/10962/303681 , vital:58361 , KHV-268
- Description: Elderly man talking about how times have changed , Use of this resource is governed by the terms and conditions of the Creative Commons "Attribution-NonCommercial-ShareAlike" License (http://creativecommons.org/licenses/by-nc-sa/2.0/) (NEVER CAHNGE THIS FIELD)
- Full Text: false
- Date Issued: 2015
Assessing the health and safety management of SMME's in the South African construction industry
- Authors: Quantoi, Phoebus Llewellyn
- Date: 2015
- Subjects: Construction industry -- Safety measures , Industrial safety -- South Africa -- Management , Small business -- Health aspects
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10948/3842 , vital:20468
- Description: The prosperity of small micro and medium enterprises (SMME’s) in the construction industry is vital for the improvement of the South African economy. Unfortunately, the poor safety record of this industry negatively affects the sustainability of SMME’s and augments the loss of human lives. Owners and managers of SMME’s in the construction industry are usually financially fragile and unaware of the direct and an indirect cost associated with injuries that may result in potential profit loss and ultimately, bankruptcy. The construction industry continues to lead with high levels of fatalities and injuries compared to other industrial sectors. High levels of non-compliance with health and safety legislation in the construction industry necessitate creative interventions to improve health and safety standards. The objective of the research was to establish to what extent SMME’s comply with health and safety in the construction industry. Research was done by means of a survey questionnaire and the findings concluded that government laws are appropriate however the enforcing of such law needs attention. Furthermore, most owners are aware of the required legislation but the competitive nature allude that “that shortcuts are taken”.
- Full Text:
- Date Issued: 2015
- Authors: Quantoi, Phoebus Llewellyn
- Date: 2015
- Subjects: Construction industry -- Safety measures , Industrial safety -- South Africa -- Management , Small business -- Health aspects
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10948/3842 , vital:20468
- Description: The prosperity of small micro and medium enterprises (SMME’s) in the construction industry is vital for the improvement of the South African economy. Unfortunately, the poor safety record of this industry negatively affects the sustainability of SMME’s and augments the loss of human lives. Owners and managers of SMME’s in the construction industry are usually financially fragile and unaware of the direct and an indirect cost associated with injuries that may result in potential profit loss and ultimately, bankruptcy. The construction industry continues to lead with high levels of fatalities and injuries compared to other industrial sectors. High levels of non-compliance with health and safety legislation in the construction industry necessitate creative interventions to improve health and safety standards. The objective of the research was to establish to what extent SMME’s comply with health and safety in the construction industry. Research was done by means of a survey questionnaire and the findings concluded that government laws are appropriate however the enforcing of such law needs attention. Furthermore, most owners are aware of the required legislation but the competitive nature allude that “that shortcuts are taken”.
- 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
Planning for the future: mapping anticipated environmental and social impacts in a nascent tourism destination
- Aswani, Shankar, Diedrich, Amy, Currier, Kitty
- Authors: Aswani, Shankar , Diedrich, Amy , Currier, Kitty
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/145415 , vital:38436 , DOI: 10.1080/08941920.2015.1020582
- Description: Tourism is a significant driver of social and ecological change in developing countries, particularly in small-island states, which are susceptible to tourism impacts due to their particular social and environmental characteristics. In this article we present a participatory mapping approach to obtaining spatially explicit local perceptions of future environmental and social change resulting from tourism development, as well as addressing the different community conflicts that may arise through the introduction of tourism in the future in a Solomon Islands community. The results show that spatial conflicts within a community over territory and associated resources are likely to occur when designing natural resource management and tourism development plans. This knowledge can help us increase the future sustainability of tourism in nascent small-islands destinations, particularly in vulnerable regions such as Roviana, which have experienced very little tourism development and will likely experience more in the near future.
- Full Text:
- Date Issued: 2015
- Authors: Aswani, Shankar , Diedrich, Amy , Currier, Kitty
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/145415 , vital:38436 , DOI: 10.1080/08941920.2015.1020582
- Description: Tourism is a significant driver of social and ecological change in developing countries, particularly in small-island states, which are susceptible to tourism impacts due to their particular social and environmental characteristics. In this article we present a participatory mapping approach to obtaining spatially explicit local perceptions of future environmental and social change resulting from tourism development, as well as addressing the different community conflicts that may arise through the introduction of tourism in the future in a Solomon Islands community. The results show that spatial conflicts within a community over territory and associated resources are likely to occur when designing natural resource management and tourism development plans. This knowledge can help us increase the future sustainability of tourism in nascent small-islands destinations, particularly in vulnerable regions such as Roviana, which have experienced very little tourism development and will likely experience more in the near future.
- Full Text:
- Date Issued: 2015
Dismissal of members of the South African Police Service for criminal convictions
- Authors: Deysel, Petrus Gerhardus
- Date: 2015
- Subjects: Employees -- Dismissal of -- South Africa , Police corruption -- South Africa , Judgments, Criminal -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: http://hdl.handle.net/10948/6084 , vital:21037
- Description: The dawn of democracy failed to bring legitimacy to the Police Service. Public and political debate seriously lambasted the Police Service for criminal offences committed on and off duty by police officials which pertained to the infringement on the individual rights regarding personal safety and the right to own property. The outcry against criminal offences by police officials forced the Police Service to deal decisively with criminality in the Police Service by means of fitness boards. While the government and public approved of the attempts to rid the Police Service of criminality it was met with union resistance in the Eastern Cape and defeat in the Labour Court. Different legislation, internal arrangements and case law were observed in this study. The purpose was to determine the strength or weaknesses if any of the applicable legislation and internal arrangements which contributed to a finding against the Police Service in the Labour Court.
- Full Text:
- Date Issued: 2015
- Authors: Deysel, Petrus Gerhardus
- Date: 2015
- Subjects: Employees -- Dismissal of -- South Africa , Police corruption -- South Africa , Judgments, Criminal -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: http://hdl.handle.net/10948/6084 , vital:21037
- Description: The dawn of democracy failed to bring legitimacy to the Police Service. Public and political debate seriously lambasted the Police Service for criminal offences committed on and off duty by police officials which pertained to the infringement on the individual rights regarding personal safety and the right to own property. The outcry against criminal offences by police officials forced the Police Service to deal decisively with criminality in the Police Service by means of fitness boards. While the government and public approved of the attempts to rid the Police Service of criminality it was met with union resistance in the Eastern Cape and defeat in the Labour Court. Different legislation, internal arrangements and case law were observed in this study. The purpose was to determine the strength or weaknesses if any of the applicable legislation and internal arrangements which contributed to a finding against the Police Service in the Labour Court.
- Full Text:
- Date Issued: 2015
Gathering drinking strong spirits with students 2
- Unnamed
- Authors: Unnamed
- Date: 2015
- Subjects: UNCATALOGUED
- Type: Video
- Identifier: http://hdl.handle.net/10962/303144 , vital:58298 , KHV-257
- Description: The gathering drinking strong spirits passing it around the room , Use of this resource is governed by the terms and conditions of the Creative Commons "Attribution-NonCommercial-ShareAlike" License (http://creativecommons.org/licenses/by-nc-sa/2.0/) (NEVER CAHNGE THIS FIELD)
- Full Text: false
- Date Issued: 2015
- Authors: Unnamed
- Date: 2015
- Subjects: UNCATALOGUED
- Type: Video
- Identifier: http://hdl.handle.net/10962/303144 , vital:58298 , KHV-257
- Description: The gathering drinking strong spirits passing it around the room , Use of this resource is governed by the terms and conditions of the Creative Commons "Attribution-NonCommercial-ShareAlike" License (http://creativecommons.org/licenses/by-nc-sa/2.0/) (NEVER CAHNGE THIS FIELD)
- Full Text: false
- Date Issued: 2015
Human harvesting impacts on managed areas: ecological effects of socially-compatible shellfish reserves
- Aswani, Shankar, Flores, Carola F, Broitman, Bernardo R
- Authors: Aswani, Shankar , Flores, Carola F , Broitman, Bernardo R
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124664 , vital:35644 , https://doi.10.1007/s11160-014-9376-4
- Description: We examined how human harvesting impacts on managed areas affect the abundance and size distribution of the edible mangrove shellfish Anadara granosa and Polymesoda spp. in the Roviana Lagoon, Solomon Islands. We tested two hypotheses: (1) in areas permanently and temporally closed to human exploitation, abundance and size distribution of these shellfish species is significantly greater than in sites open to exploitation and (2) moderate human disturbance of shell beds, particularly of Polymesoda spp., increases their abundance. Firstly, we studied perceptions of environmental states and processes coupled to foraging and management interventions to assess sociocultural influences on harvesting practices and ascertain the types of management regime that people would consider in a context where poaching and interloping are common practices. Secondly, we compared shellfish abundance and shell size from areas that were permanently protected, temporally reserved for communal harvest, and permanently open for exploitation. Thirdly, drawing from women’s local knowledge, we measured the abundance of Polymesoda spp. in relation to mud compactness in quadrats across the three management regimes. Results showed that both species were significantly more abundant in permanent and temporally closed sites than in open sites. In the mud compactness study, however, while shell abundance was greater in moderately compacted quadrats, there was no statistical relationship between mud compactness and shell abundance within or across the three management regimes. Results suggest that even under the strong impacts of poaching, temporally closed areas have more clams than open areas and are as effective as areas that are permanently closed nominally. The results also suggest that human harvesting regimes can influence the effectiveness of local management decisions and thus are important when designing community-based conservation programs in the Solomon Islands and other Pacific Islands.
- Full Text:
- Date Issued: 2015
- Authors: Aswani, Shankar , Flores, Carola F , Broitman, Bernardo R
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124664 , vital:35644 , https://doi.10.1007/s11160-014-9376-4
- Description: We examined how human harvesting impacts on managed areas affect the abundance and size distribution of the edible mangrove shellfish Anadara granosa and Polymesoda spp. in the Roviana Lagoon, Solomon Islands. We tested two hypotheses: (1) in areas permanently and temporally closed to human exploitation, abundance and size distribution of these shellfish species is significantly greater than in sites open to exploitation and (2) moderate human disturbance of shell beds, particularly of Polymesoda spp., increases their abundance. Firstly, we studied perceptions of environmental states and processes coupled to foraging and management interventions to assess sociocultural influences on harvesting practices and ascertain the types of management regime that people would consider in a context where poaching and interloping are common practices. Secondly, we compared shellfish abundance and shell size from areas that were permanently protected, temporally reserved for communal harvest, and permanently open for exploitation. Thirdly, drawing from women’s local knowledge, we measured the abundance of Polymesoda spp. in relation to mud compactness in quadrats across the three management regimes. Results showed that both species were significantly more abundant in permanent and temporally closed sites than in open sites. In the mud compactness study, however, while shell abundance was greater in moderately compacted quadrats, there was no statistical relationship between mud compactness and shell abundance within or across the three management regimes. Results suggest that even under the strong impacts of poaching, temporally closed areas have more clams than open areas and are as effective as areas that are permanently closed nominally. The results also suggest that human harvesting regimes can influence the effectiveness of local management decisions and thus are important when designing community-based conservation programs in the Solomon Islands and other Pacific Islands.
- Full Text:
- Date Issued: 2015
Chemical constituents and biological studies of Tagetes minuta L. and Rauvolfia caffra Sond
- Authors: Mlala, Sithenkosi
- Date: 2015
- Language: English
- Type: Thesis , Masters , MSc (Organic Chemistry)
- Identifier: vital:11358 , http://hdl.handle.net/10353/d1021325
- Description: Consequently, specific parts or the whole plant can be used for various treatments. The aim of this study was to extract, isolate and characterize the biologically active volatile and non-volatile compounds from Tagetes minuta and Rauvolfia caffra respectively. Tagetes minuta plant was considered for extraction of essential oils using hydrodistillation method. Cis-β-ocimene (38.03%), caryophyllene oxide (18.04%), alloocimene (25.35 %), isopropyl tetradecanoate (17.02 %), cis-ocimene (38.14%) and trans-β-ocimene (37.03%) were the major components of essential oil analyzed from fresh stem, dried stem, fresh leaf, dried leaf, fresh flower and dried flower respectively. The volatile compounds were identified by Gas Chromatography-Mass Spectrometry (GC-MS) and Gas Chromatography (GC). Essential oil of dried stem leaf and flower parts of T. minuta exhibit antioxidant activity as demonstrated by the DPPH and FRAP bioassays. Crude extracts were extracted from R. caffra stem bark using sequence of solvents namely n-hexane, dichloromethane, ethyl acetate, methanol and ethanol. A white powder, a β-sitosterol (non-volatile compound) was isolated by column chromatography from ethyl acetate fractions of R. caffra stem bark and identified on various spectroscopic techniques such as FTIR and (1D and 2D) NMR. Melting point was also determined to be a sharp 129-130 ºC. DCM, EA, MetOH and EtOH fractions as well as β-Sitosterol (compound SM/01), showed antioxidant activity when tested on DPPH, FRAP, total phenolic and flavonoid bioassays. This antioxidant activity might be due to the presence of hydroxyl groups in the compound and crude fractions. On the other hand, T. minuta’s essential oil showed high antioxidant activity when evaluated on the DPPH and FRAP bioassays, which can be attributed to the presence of oxygenated monoterpenes and sesquiterpenes known to act as free radical scavenging and reducing agents. The use of R. caffra stem bark extracts against hypertension and other diseases by traditional healers could be attributed to the presence of phytochemicals (polyphenols and flavonoids) with known health benefits. Thus, it is recommended that the plant should be exploited further using modern techniques involving separation and purification of compounds that can be used for drug formulation. This study supports the use of T. minuta and R. caffra as the potential natural antioxidant source to manage various diseases including hypertension.
- Full Text:
- Date Issued: 2015
- Authors: Mlala, Sithenkosi
- Date: 2015
- Language: English
- Type: Thesis , Masters , MSc (Organic Chemistry)
- Identifier: vital:11358 , http://hdl.handle.net/10353/d1021325
- Description: Consequently, specific parts or the whole plant can be used for various treatments. The aim of this study was to extract, isolate and characterize the biologically active volatile and non-volatile compounds from Tagetes minuta and Rauvolfia caffra respectively. Tagetes minuta plant was considered for extraction of essential oils using hydrodistillation method. Cis-β-ocimene (38.03%), caryophyllene oxide (18.04%), alloocimene (25.35 %), isopropyl tetradecanoate (17.02 %), cis-ocimene (38.14%) and trans-β-ocimene (37.03%) were the major components of essential oil analyzed from fresh stem, dried stem, fresh leaf, dried leaf, fresh flower and dried flower respectively. The volatile compounds were identified by Gas Chromatography-Mass Spectrometry (GC-MS) and Gas Chromatography (GC). Essential oil of dried stem leaf and flower parts of T. minuta exhibit antioxidant activity as demonstrated by the DPPH and FRAP bioassays. Crude extracts were extracted from R. caffra stem bark using sequence of solvents namely n-hexane, dichloromethane, ethyl acetate, methanol and ethanol. A white powder, a β-sitosterol (non-volatile compound) was isolated by column chromatography from ethyl acetate fractions of R. caffra stem bark and identified on various spectroscopic techniques such as FTIR and (1D and 2D) NMR. Melting point was also determined to be a sharp 129-130 ºC. DCM, EA, MetOH and EtOH fractions as well as β-Sitosterol (compound SM/01), showed antioxidant activity when tested on DPPH, FRAP, total phenolic and flavonoid bioassays. This antioxidant activity might be due to the presence of hydroxyl groups in the compound and crude fractions. On the other hand, T. minuta’s essential oil showed high antioxidant activity when evaluated on the DPPH and FRAP bioassays, which can be attributed to the presence of oxygenated monoterpenes and sesquiterpenes known to act as free radical scavenging and reducing agents. The use of R. caffra stem bark extracts against hypertension and other diseases by traditional healers could be attributed to the presence of phytochemicals (polyphenols and flavonoids) with known health benefits. Thus, it is recommended that the plant should be exploited further using modern techniques involving separation and purification of compounds that can be used for drug formulation. This study supports the use of T. minuta and R. caffra as the potential natural antioxidant source to manage various diseases including hypertension.
- Full Text:
- Date Issued: 2015
An analysis of the risk exposure of adopting IPV6 in enterprise networks
- Authors: Berko, Istvan Sandor
- Date: 2015
- Subjects: International Workshop on Deploying the Future Infrastructure , Computer networks , Computer networks -- Security measures , Computer network protocols
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4722 , http://hdl.handle.net/10962/d1018918
- Description: The IPv6 increased address pool presents changes in resource impact to the Enterprise that, if not adequately addressed, can change risks that are locally significant in IPv4 to risks that can impact the Enterprise in its entirety. The expected conclusion is that the IPv6 environment will impose significant changes in the Enterprise environment - which may negatively impact organisational security if the IPv6 nuances are not adequately addressed. This thesis reviews the risks related to the operation of enterprise networks with the introduction of IPv6. The global trends are discussed to provide insight and background to the IPv6 research space. Analysing the current state of readiness in enterprise networks, quantifies the value of developing this thesis. The base controls that should be deployed in enterprise networks to prevent the abuse of IPv6 through tunnelling and the protection of the enterprise access layer are discussed. A series of case studies are presented which identify and analyse the impact of certain changes in the IPv6 protocol on the enterprise networks. The case studies also identify mitigation techniques to reduce risk.
- Full Text:
- Date Issued: 2015
- Authors: Berko, Istvan Sandor
- Date: 2015
- Subjects: International Workshop on Deploying the Future Infrastructure , Computer networks , Computer networks -- Security measures , Computer network protocols
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4722 , http://hdl.handle.net/10962/d1018918
- Description: The IPv6 increased address pool presents changes in resource impact to the Enterprise that, if not adequately addressed, can change risks that are locally significant in IPv4 to risks that can impact the Enterprise in its entirety. The expected conclusion is that the IPv6 environment will impose significant changes in the Enterprise environment - which may negatively impact organisational security if the IPv6 nuances are not adequately addressed. This thesis reviews the risks related to the operation of enterprise networks with the introduction of IPv6. The global trends are discussed to provide insight and background to the IPv6 research space. Analysing the current state of readiness in enterprise networks, quantifies the value of developing this thesis. The base controls that should be deployed in enterprise networks to prevent the abuse of IPv6 through tunnelling and the protection of the enterprise access layer are discussed. A series of case studies are presented which identify and analyse the impact of certain changes in the IPv6 protocol on the enterprise networks. The case studies also identify mitigation techniques to reduce risk.
- Full Text:
- Date Issued: 2015
Methods to improve the effective implementation of organisational codes of conduct
- Robinson, Bryan Michael Kenneth
- Authors: Robinson, Bryan Michael Kenneth
- Date: 2015
- Subjects: Business ethics , Organizational behavior -- Moral and ethical aspects
- Language: English
- Type: Thesis , Doctoral , DBA
- Identifier: http://hdl.handle.net/10948/6541 , vital:21105
- Description: This research explores methods to improve code of conduct effectiveness. Misconduct is a common phenomenon in the business environment, even in the face of increased regulation, and the adoption of codes of conduct by organisations. This impacts negatively on organisations’ reputations, results in financial loss, and has a negative impact on the sustainability of businesses. While researchers suggest that codes of conduct should reduce misconduct and improve the ethical culture of organisations, mixed research results suggest codes of conduct are not always effective. While research into code of conduct effectiveness proliferates, seldom does such research take a holistic approach to understanding effectiveness of codes of conduct. Models proposed to better research code of conduct effectiveness, such as Kaptein and Schwartz’ (2008) integrated research model, do not present guidelines for better developing and implementing codes of conduct. Therefore the primary research objective was to develop a benchmarking framework which could provide insight into factors that could influence code of conduct effectiveness, and provide guidelines on how these factors should be influenced and accounted for to improve code of conduct effectiveness. Content of codes of conduct can play an important part in code of conduct effectiveness, yet they vary enormously in terms of provisions, language, tone, style, design. Some are directional or rules based, others aspirational, or values based. Bettcher, Deshpandé, Margolis and Paine (2005) developed the Global Business Standards Codex that depicted the most commonly found provisions in organisations they surveyed. A secondary research objective was therefore to apply this codex to the evaluation of participating organisations codes of conduct, and in so doing, evaluate the suitability of the codex as a benchmarking framework for the content of the code of conduct. Adopting a grounded theory methodological approach and code of conduct content analysis, the researcher investigated nine of South Africa’s largest multinational organisations in order to understand the factors influencing their code of conduct effectiveness better. The research makes a significant contribution to the understanding of codes of conduct, their effectiveness, and provides practical guidelines on improving their effectiveness. This is achieved by 1) presenting nine formulae for an effective code of conduct; 2) detailing a multi-dimensional model that can facilitate the effectiveness of codes of conduct; and 3) improving the codex developed by Bettcher et al. (2005) on the content of codes of conduct with the proposed code of conduct architecture criterion.
- Full Text:
- Date Issued: 2015
- Authors: Robinson, Bryan Michael Kenneth
- Date: 2015
- Subjects: Business ethics , Organizational behavior -- Moral and ethical aspects
- Language: English
- Type: Thesis , Doctoral , DBA
- Identifier: http://hdl.handle.net/10948/6541 , vital:21105
- Description: This research explores methods to improve code of conduct effectiveness. Misconduct is a common phenomenon in the business environment, even in the face of increased regulation, and the adoption of codes of conduct by organisations. This impacts negatively on organisations’ reputations, results in financial loss, and has a negative impact on the sustainability of businesses. While researchers suggest that codes of conduct should reduce misconduct and improve the ethical culture of organisations, mixed research results suggest codes of conduct are not always effective. While research into code of conduct effectiveness proliferates, seldom does such research take a holistic approach to understanding effectiveness of codes of conduct. Models proposed to better research code of conduct effectiveness, such as Kaptein and Schwartz’ (2008) integrated research model, do not present guidelines for better developing and implementing codes of conduct. Therefore the primary research objective was to develop a benchmarking framework which could provide insight into factors that could influence code of conduct effectiveness, and provide guidelines on how these factors should be influenced and accounted for to improve code of conduct effectiveness. Content of codes of conduct can play an important part in code of conduct effectiveness, yet they vary enormously in terms of provisions, language, tone, style, design. Some are directional or rules based, others aspirational, or values based. Bettcher, Deshpandé, Margolis and Paine (2005) developed the Global Business Standards Codex that depicted the most commonly found provisions in organisations they surveyed. A secondary research objective was therefore to apply this codex to the evaluation of participating organisations codes of conduct, and in so doing, evaluate the suitability of the codex as a benchmarking framework for the content of the code of conduct. Adopting a grounded theory methodological approach and code of conduct content analysis, the researcher investigated nine of South Africa’s largest multinational organisations in order to understand the factors influencing their code of conduct effectiveness better. The research makes a significant contribution to the understanding of codes of conduct, their effectiveness, and provides practical guidelines on improving their effectiveness. This is achieved by 1) presenting nine formulae for an effective code of conduct; 2) detailing a multi-dimensional model that can facilitate the effectiveness of codes of conduct; and 3) improving the codex developed by Bettcher et al. (2005) on the content of codes of conduct with the proposed code of conduct architecture criterion.
- Full Text:
- Date Issued: 2015
Assessment of bioflocculant production by two marine bacteria isolated from the bottom sediment of marine Algoa Bay
- Authors: Ntozonke, Ncedo
- Date: 2015
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11298 , http://hdl.handle.net/10353/d1021290
- Description: Bioflocculants are polymers, mostly, of microbial origin which floc out suspended particles from liquid medium. The ability of these biopolymers to remove suspended particles from solutions is termed bioflocculation, and the efficiency of flocculation activities depends on the characteristics of the flocculants. In comparison with conventionally used flocculants, bioflocculants have the advantage of being safe (no toxic effects known), biodegradable and harmlessness to the environment. The study assessed production of bioflocculant by two marine bacteria from the bottom sediment of marine environment. The 16S rDNA was used for identification, and the two bacteria species were identified as Enterococcus hirae and Bacillus thuringiensis. Factors affecting the production and activity of the bioflocculants produced by these two organisms were studied. The bacteria optimally produced bioflocculant with fructose (91.7%) and urea (91%) as sole carbon and nitrogen sources respectively. Mg2+ (87%) and Ca2+ (86%), likewise, served as best cation sources on the production of the bioflocculant at pH 5(93%). Additionally, the flocculating activity of the bioflocculant increased with the addition of Mg2+ (81%) and Na+ (81%), and the highest flocculating activity was at pH 5 of the kaolin clay. The Fourier transform infrared spectroscopy (FTIR) shows that the bioflocculant is a glycoprotein. The second bacterium (Bacillus thuringiensis) produced bioflocculant optimally when the media had mixed nitrogen sources (Urea, ammonium chloride and tryptone (67%)) and glucose (85.65%) as a sole carbon source, also Ca2+ (74.6%) was the best cation that induced the production of bioflocculant. After purification, the bioflocculant flocculated optimally in alkaline pH 12 (81%) in the presence of Mn2+ (73%) and Ca2+ (72.8%). Chemical analysis of the bioflocculant revealed it to be a polysaccharide. Both bioflocculants flocculate efficiently and can be used to replace synthetic flocculants in water treatment, wastewater, in downstream processing, and processing of food and chemicals and other industrial uses of flocculants. Challenges though (i) are to develop conditions for large scale production of the bioflocculant, (ii) to do further characterization of the both bioflocculants (iii) to assess the bioflocculants for treatments of water/wastewater, and to apply it in various industrial processes.
- Full Text:
- Date Issued: 2015
- Authors: Ntozonke, Ncedo
- Date: 2015
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11298 , http://hdl.handle.net/10353/d1021290
- Description: Bioflocculants are polymers, mostly, of microbial origin which floc out suspended particles from liquid medium. The ability of these biopolymers to remove suspended particles from solutions is termed bioflocculation, and the efficiency of flocculation activities depends on the characteristics of the flocculants. In comparison with conventionally used flocculants, bioflocculants have the advantage of being safe (no toxic effects known), biodegradable and harmlessness to the environment. The study assessed production of bioflocculant by two marine bacteria from the bottom sediment of marine environment. The 16S rDNA was used for identification, and the two bacteria species were identified as Enterococcus hirae and Bacillus thuringiensis. Factors affecting the production and activity of the bioflocculants produced by these two organisms were studied. The bacteria optimally produced bioflocculant with fructose (91.7%) and urea (91%) as sole carbon and nitrogen sources respectively. Mg2+ (87%) and Ca2+ (86%), likewise, served as best cation sources on the production of the bioflocculant at pH 5(93%). Additionally, the flocculating activity of the bioflocculant increased with the addition of Mg2+ (81%) and Na+ (81%), and the highest flocculating activity was at pH 5 of the kaolin clay. The Fourier transform infrared spectroscopy (FTIR) shows that the bioflocculant is a glycoprotein. The second bacterium (Bacillus thuringiensis) produced bioflocculant optimally when the media had mixed nitrogen sources (Urea, ammonium chloride and tryptone (67%)) and glucose (85.65%) as a sole carbon source, also Ca2+ (74.6%) was the best cation that induced the production of bioflocculant. After purification, the bioflocculant flocculated optimally in alkaline pH 12 (81%) in the presence of Mn2+ (73%) and Ca2+ (72.8%). Chemical analysis of the bioflocculant revealed it to be a polysaccharide. Both bioflocculants flocculate efficiently and can be used to replace synthetic flocculants in water treatment, wastewater, in downstream processing, and processing of food and chemicals and other industrial uses of flocculants. Challenges though (i) are to develop conditions for large scale production of the bioflocculant, (ii) to do further characterization of the both bioflocculants (iii) to assess the bioflocculants for treatments of water/wastewater, and to apply it in various industrial processes.
- Full Text:
- Date Issued: 2015
Environmental ethics, protection and valuation
- Authors: Du Preez, M
- Subjects: Environmental ethics , Environmental protection , f-sa
- Language: English
- Type: text , Lectures
- Identifier: http://hdl.handle.net/10948/21022 , vital:29428
- Description: This lecture addresses the environmental ethics, protection and valuation of natural assets. The aim of the lecture is threefold: first, to present a bio-ethical argument for the extension of our moral reference class to include all conscious and non-conscious natural assets; second, to discuss the moral significance of a broader moral reference class in terms of Aldo Leopold’s ‘Land Ethic’; third, to discuss the valuation of natural assets from a system’s perspective with specific reference to the estimation of non-use values. In what follows, Section I discusses environmental protection from a bioethical point of view, Section II discusses the moral significance of a broader moral reference class in terms of Aldo Leopold’s ‘Land Ethic’, Section III describes the concept of valuing natural assets with specific reference to the concept of non-use value and its measurement, and finally, Section IV concludes the lecture.
- Full Text:
- Authors: Du Preez, M
- Subjects: Environmental ethics , Environmental protection , f-sa
- Language: English
- Type: text , Lectures
- Identifier: http://hdl.handle.net/10948/21022 , vital:29428
- Description: This lecture addresses the environmental ethics, protection and valuation of natural assets. The aim of the lecture is threefold: first, to present a bio-ethical argument for the extension of our moral reference class to include all conscious and non-conscious natural assets; second, to discuss the moral significance of a broader moral reference class in terms of Aldo Leopold’s ‘Land Ethic’; third, to discuss the valuation of natural assets from a system’s perspective with specific reference to the estimation of non-use values. In what follows, Section I discusses environmental protection from a bioethical point of view, Section II discusses the moral significance of a broader moral reference class in terms of Aldo Leopold’s ‘Land Ethic’, Section III describes the concept of valuing natural assets with specific reference to the concept of non-use value and its measurement, and finally, Section IV concludes the lecture.
- Full Text:
Montane Wetlands of the South African Great Escarpment : plant communities and environmental drivers
- Authors: Janks, Matthew Richard
- Date: 2015
- Subjects: Mountain plants -- South Africa -- Eastern Cape , Wetland plants -- South Africa -- Eastern Cape , Wetland plants -- Effect of altitude on -- South Africa -- Eastern Cape , Wetland ecology -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4274 , http://hdl.handle.net/10962/d1018917
- Description: Wetlands provide a number of valuable functions to both the surrounding environment and society. The anaerobic conditions created by flooding in wetlands provide a habitat that supports unique assemblages of plant life. High altitude wetlands are amongst the most species-rich in South Africa. They house a number of rare species and play a vital role in the supply of water to lower lying areas. These are some of the reasons that mountain wetlands are of high conservation value. A phytosociological study was undertaken on the high altitude wetlands of the Great Escarpment with the aim of classifying the plant communities and identifying the environmental drivers of plant community patterns within these ecosystems. Data collection was focused in the Eastern Cape and was supplemented with data from existing studies to gain a more complete understanding of the wetlands of the Great Escarpment of South Africa. Using the Braun-Blanquet approach, Hierarchical Cluster Analysis and Indicator Species Analysis; five broad wetland groups were identified, comprised of 33 individual plant communities and 81 indicator species. Multivariate analysis, including Canonical Correspondence Analysis revealed that the effects of altitude, such as temperature and rainfall, are the most significant large-scale drivers of vegetation patterns. Smaller scale drivers include wetness and soil nutrients including nitrogen, phosphorus, electrical conductivity, sodium, and organic content. The identification of indicator species served to reveal potentially important wetland species across different areas of the Great Escarpment. The effects of altitude on plant community patterns highlights the susceptibility of the high altitude specific communities to upward temperature zone shifts resulting from global warming. Other threats include livestock trampling, water extraction, and land use change for agricultural purposes. The relative absence of alien species in these wetlands gives an indication of their pristine condition and therefore their importance as a reference from which they may be monitored. A large proportion of the wetlands studied here occur outside protected areas, and given the rate of wetland loss in South Africa, it is important that continued effective land management is practiced to ensure that these ecosystems are conserved in the future .
- Full Text:
- Date Issued: 2015
Montane Wetlands of the South African Great Escarpment : plant communities and environmental drivers
- Authors: Janks, Matthew Richard
- Date: 2015
- Subjects: Mountain plants -- South Africa -- Eastern Cape , Wetland plants -- South Africa -- Eastern Cape , Wetland plants -- Effect of altitude on -- South Africa -- Eastern Cape , Wetland ecology -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4274 , http://hdl.handle.net/10962/d1018917
- Description: Wetlands provide a number of valuable functions to both the surrounding environment and society. The anaerobic conditions created by flooding in wetlands provide a habitat that supports unique assemblages of plant life. High altitude wetlands are amongst the most species-rich in South Africa. They house a number of rare species and play a vital role in the supply of water to lower lying areas. These are some of the reasons that mountain wetlands are of high conservation value. A phytosociological study was undertaken on the high altitude wetlands of the Great Escarpment with the aim of classifying the plant communities and identifying the environmental drivers of plant community patterns within these ecosystems. Data collection was focused in the Eastern Cape and was supplemented with data from existing studies to gain a more complete understanding of the wetlands of the Great Escarpment of South Africa. Using the Braun-Blanquet approach, Hierarchical Cluster Analysis and Indicator Species Analysis; five broad wetland groups were identified, comprised of 33 individual plant communities and 81 indicator species. Multivariate analysis, including Canonical Correspondence Analysis revealed that the effects of altitude, such as temperature and rainfall, are the most significant large-scale drivers of vegetation patterns. Smaller scale drivers include wetness and soil nutrients including nitrogen, phosphorus, electrical conductivity, sodium, and organic content. The identification of indicator species served to reveal potentially important wetland species across different areas of the Great Escarpment. The effects of altitude on plant community patterns highlights the susceptibility of the high altitude specific communities to upward temperature zone shifts resulting from global warming. Other threats include livestock trampling, water extraction, and land use change for agricultural purposes. The relative absence of alien species in these wetlands gives an indication of their pristine condition and therefore their importance as a reference from which they may be monitored. A large proportion of the wetlands studied here occur outside protected areas, and given the rate of wetland loss in South Africa, it is important that continued effective land management is practiced to ensure that these ecosystems are conserved in the future .
- Full Text:
- Date Issued: 2015
A best practice guideline for evidence based teaching strategies for nurse educators
- Authors: Breytenbach, Cecile
- Date: 2015
- Subjects: Nursing -- Study and teaching -- Great Britain , Nurse educators , Evidence-based nursing
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/4831 , vital:20699
- Description: Evidence based practice (EBP) is a worldwide phenomena defined as the “conscientious explicit and judicious use of current best evidence in making decisions about the patient’s care”. The evidence based practice concept’s aim is to effectively guide health care professionals to build knowledge that will be supported by evidence. Evidence based practice must be supported by evidence based teaching. Nurse educators must be up to date with evidence based teaching as well as the latest evidence based teaching strategies, in order to teach the new millennial nursing students and for the new qualifications structure. Teaching the concept of evidence based practice by implementing evidence based teaching to nursing students will enable them to transform the future of healthcare by delivering high quality care practice. A paucity of evidence is available on evidence based teaching and teaching strategies in the South African context. Therefore the researcher used a systematic review methodology to explore and describe the best available evidence based teaching strategies and to develop a guideline on evidence based teaching strategies for nurse educators. The data bases searched included: MEDLINE, CINAHL, PubMed and Google Scholar. Manual searches were done and completed with the assistance of librarians. A total number of n=50 studies were identified as potentially relevant to the study. The number or articles included for critical appraisal were 20. On completion of the critical appraisal n=17 articles were identified for the review. The included studies for the review were n=7 Level 1, systematic reviews and n=10 Level 2, quasi-experimental studies. Three studies were excluded after critical appraisal from two reviewers, appraisal was done independently, and consensuses were reached between the two reviewers. The Joanna Briggs Institutes critical appraisal and data extraction instruments were used for the study. The descriptive data synthesis was done of the included studies as well as a comparison of teaching strategies to determine which one to better than the other one. Although n = 4 of the teaching strategies (concept mapping, internet-based learning, evidence based interactive strategy and cultural competence) significantly increased knowledge, the overall results found that a variety of teaching strategies to be implemented to increase the knowledge outcomes of the nursing students. The different teaching strategies found were: e-learning, concept mapping, internet-based learning, web-based learning, gaming, problem-based learning, and case studies, evidence based learning and cultural competence. However, more research is needed to investigate the best use of the different teaching strategies and compare the impact of a variety of teaching strategies on increasing knowledge of the nursing student.
- Full Text:
- Date Issued: 2015
- Authors: Breytenbach, Cecile
- Date: 2015
- Subjects: Nursing -- Study and teaching -- Great Britain , Nurse educators , Evidence-based nursing
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/4831 , vital:20699
- Description: Evidence based practice (EBP) is a worldwide phenomena defined as the “conscientious explicit and judicious use of current best evidence in making decisions about the patient’s care”. The evidence based practice concept’s aim is to effectively guide health care professionals to build knowledge that will be supported by evidence. Evidence based practice must be supported by evidence based teaching. Nurse educators must be up to date with evidence based teaching as well as the latest evidence based teaching strategies, in order to teach the new millennial nursing students and for the new qualifications structure. Teaching the concept of evidence based practice by implementing evidence based teaching to nursing students will enable them to transform the future of healthcare by delivering high quality care practice. A paucity of evidence is available on evidence based teaching and teaching strategies in the South African context. Therefore the researcher used a systematic review methodology to explore and describe the best available evidence based teaching strategies and to develop a guideline on evidence based teaching strategies for nurse educators. The data bases searched included: MEDLINE, CINAHL, PubMed and Google Scholar. Manual searches were done and completed with the assistance of librarians. A total number of n=50 studies were identified as potentially relevant to the study. The number or articles included for critical appraisal were 20. On completion of the critical appraisal n=17 articles were identified for the review. The included studies for the review were n=7 Level 1, systematic reviews and n=10 Level 2, quasi-experimental studies. Three studies were excluded after critical appraisal from two reviewers, appraisal was done independently, and consensuses were reached between the two reviewers. The Joanna Briggs Institutes critical appraisal and data extraction instruments were used for the study. The descriptive data synthesis was done of the included studies as well as a comparison of teaching strategies to determine which one to better than the other one. Although n = 4 of the teaching strategies (concept mapping, internet-based learning, evidence based interactive strategy and cultural competence) significantly increased knowledge, the overall results found that a variety of teaching strategies to be implemented to increase the knowledge outcomes of the nursing students. The different teaching strategies found were: e-learning, concept mapping, internet-based learning, web-based learning, gaming, problem-based learning, and case studies, evidence based learning and cultural competence. However, more research is needed to investigate the best use of the different teaching strategies and compare the impact of a variety of teaching strategies on increasing knowledge of the nursing student.
- Full Text:
- Date Issued: 2015
Evaluation of the quality indices of the final effluents of two wastewater treatment plants in buffalo City Metropolitan Municipality in the Eastern Cape Province
- Authors: Osuolale, Olayinka O
- Date: 2015
- Language: English
- Type: Thesis , Doctoral , PhD (Microbiology)
- Identifier: vital:11292 , http://hdl.handle.net/10353/d1021079
- Description: Waste waters can be sources of pollution to surface water and the environment with severe implications for public health. Most treatment plants in the Buffalo City Municipality in the Eastern Cape Province discharge their treated effluent into the surface waters which directly and indirectly impacts on the quality of surface waters in the region. The objective of this study was to determine the microbiological and physicochemical qualities of the final effluents of two wastewater treatment plants in the Buffalo City Municipality in the Eastern Cape Province of South Africa over a period of 12 months (September 2012 to August 2013). The qualities of the final effluents of WW-Ama Wastewater Treatment Plant with respect to phosphate (3.9 mg/l - 20.6 mg/l), free chlorine (0.05 mg/l - 0.71 mg/l), chemical oxygen demand (COD) (4.7 mg/l - 211 mg/l), and faecal coliform (0 - 2.92 × 104 CFU/100 ml) were not in compliance with the permissible limits set for effluent discharged to surface water by South Africa guidelines for effluent discharge. Other physicochemical parameters like biological oxygen demand (BOD) (2.2 mg/l - 9.0 mg/l), total dissolve solid (TDS) (253 mg/l - 336.3 mg/l) and turbidity (4.8 NTU - 43.20 NTU) with no SA regulatory set limits were compared to other regulatory standards and they do not comply with the limits. Also, at the second WWTP’s, the WW-Dim Treatment Plant effluent quality for free chlorine (0.06 mg/l - 7.2 mg/l), BOD (0.1 mg/l - 7.4 mg/l), and turbidity (4.02 NTU - 24.3 NTU) also did not comply. For microbiological qualities, counts of presumptive E. coli and Vibrio ranged between 0 - 2.92 × PROFESSOR ANTHONY I. OKOHAntibiogram of the bacterial isolates were determined using the disk diffusion method. A total of 107 confirmed E. coli and 100 confirmed Vibrio spp. were used for this assay. Results of antibiotic sensitivity test revealed that 63.6% of the E. coli isolates were resistance to ampicillin while 49.5% were resistant to tetracycline and cephalothin. The least resistances were observed against gentamicin (3.7%) and cefotaxime (1.9%). No resistance was observed against meropenem. For the Vibrio spp, resistance was most frequently observed against tetracycline (38%) ampicillin (26%), chloramphenicol (16%), cefotaxime (14%), trimethoprim-sulfamethoxazole (13%) and the least resistance observed was against ciprofloxacin (1%). This study demonstrates that poorly treated wastewater effluent can be a source of eutrophic water with high nutrient levels and pathogenic bacteria and enteric viruses as well as antibiotic resistance determinants that could impact negatively on human health. The finding of this study also suggests that WWTPs have to be properly monitored and controlled to ensure compliance to set guidelines. This could be attained through the application of appropriate treatment processes, which will help to minimize possible dangers to public environment health.
- Full Text:
- Date Issued: 2015
- Authors: Osuolale, Olayinka O
- Date: 2015
- Language: English
- Type: Thesis , Doctoral , PhD (Microbiology)
- Identifier: vital:11292 , http://hdl.handle.net/10353/d1021079
- Description: Waste waters can be sources of pollution to surface water and the environment with severe implications for public health. Most treatment plants in the Buffalo City Municipality in the Eastern Cape Province discharge their treated effluent into the surface waters which directly and indirectly impacts on the quality of surface waters in the region. The objective of this study was to determine the microbiological and physicochemical qualities of the final effluents of two wastewater treatment plants in the Buffalo City Municipality in the Eastern Cape Province of South Africa over a period of 12 months (September 2012 to August 2013). The qualities of the final effluents of WW-Ama Wastewater Treatment Plant with respect to phosphate (3.9 mg/l - 20.6 mg/l), free chlorine (0.05 mg/l - 0.71 mg/l), chemical oxygen demand (COD) (4.7 mg/l - 211 mg/l), and faecal coliform (0 - 2.92 × 104 CFU/100 ml) were not in compliance with the permissible limits set for effluent discharged to surface water by South Africa guidelines for effluent discharge. Other physicochemical parameters like biological oxygen demand (BOD) (2.2 mg/l - 9.0 mg/l), total dissolve solid (TDS) (253 mg/l - 336.3 mg/l) and turbidity (4.8 NTU - 43.20 NTU) with no SA regulatory set limits were compared to other regulatory standards and they do not comply with the limits. Also, at the second WWTP’s, the WW-Dim Treatment Plant effluent quality for free chlorine (0.06 mg/l - 7.2 mg/l), BOD (0.1 mg/l - 7.4 mg/l), and turbidity (4.02 NTU - 24.3 NTU) also did not comply. For microbiological qualities, counts of presumptive E. coli and Vibrio ranged between 0 - 2.92 × PROFESSOR ANTHONY I. OKOHAntibiogram of the bacterial isolates were determined using the disk diffusion method. A total of 107 confirmed E. coli and 100 confirmed Vibrio spp. were used for this assay. Results of antibiotic sensitivity test revealed that 63.6% of the E. coli isolates were resistance to ampicillin while 49.5% were resistant to tetracycline and cephalothin. The least resistances were observed against gentamicin (3.7%) and cefotaxime (1.9%). No resistance was observed against meropenem. For the Vibrio spp, resistance was most frequently observed against tetracycline (38%) ampicillin (26%), chloramphenicol (16%), cefotaxime (14%), trimethoprim-sulfamethoxazole (13%) and the least resistance observed was against ciprofloxacin (1%). This study demonstrates that poorly treated wastewater effluent can be a source of eutrophic water with high nutrient levels and pathogenic bacteria and enteric viruses as well as antibiotic resistance determinants that could impact negatively on human health. The finding of this study also suggests that WWTPs have to be properly monitored and controlled to ensure compliance to set guidelines. This could be attained through the application of appropriate treatment processes, which will help to minimize possible dangers to public environment health.
- Full Text:
- Date Issued: 2015
Understanding how Grade 11 life sciences teachers mediate biodiversity concepts in a second language context : a case study
- Authors: Gqoloqa, Zingisa
- Date: 2015
- Subjects: Life sciences -- Study and teaching (Secondary) -- South Africa -- Eastern Cape , Language and education
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:2028 , http://hdl.handle.net/10962/d1017339
- Description: This research focused on an investigation of the pedagogy and strategies used by Grade 11 Life Sciences teachers when mediating Biodiversity concepts with English second language learners. My interest in this investigation was triggered by the Examiners’ Reports for Life Sciences from 2009 to 2012 which consistently noted learner challenges in answering, interpreting and analysing questions during exams. The reports highlighted learners’ lack of understanding of the questions which led to them providing irrelevant information in their exam scripts. These reports claimed that challenges experienced by these learners could be attributed to language issues experienced by English second language learners. Influenced by these reports, a qualitative case study of two Senior Secondary schools in East London, Eastern Cape South Africa was conducted. Underpinned by an interpretive paradigm and driven by the desire to achieve an in-depth understanding of the case under study, three phases of information gathering were followed. The first phase was that of gathering information through document analysis. Documents were analysed to gain insights and understanding of the issue before conducting interviews. The next phase was that of gathering information through semi-structured interviews followed by classroom observations. Findings from these observations were verified through stimulated recall interviews which provided clarity on the intentionality of choosing a certain method and strategy over another when assisting learners in making meaning of biodiversity concepts. The main findings of this study are that factors which limit learner understanding of biodiversity concepts are a result of a combination of factors such as failure to interpret questions, spelling problems which alter meaning of concepts and an inability to make distinctions among closely related concepts within the topic of Biodiversity. Responding to these factors, teachers demonstrated knowledge of a variety of teaching strategies to support learners. The choice of teaching strategies seemed to be guided by their experiences as well as the challenges they often encounter. Furthermore, teachers’ reflections on their practice provided opportunities for them to identify strengths and limitations of their choice of strategies and possibilities for improvement. It was also noted that factors such as large class sizes, gaps in content knowledge and a lack of detail in chalkboard summary limited the effectiveness of their teaching strategies. The study recommends that: • Teacher-learner ratio needs to be considered for effective support; • There is still a need to capacitate educators in environmental education. In-service training should focus on developing teacher understanding of foundational knowledge in life sciences; and • Teachers need to improve their chalkboard summary skills to increase the level of support that could be provided by comprehensive chalkboard summary through the elaboration of ideas
- Full Text:
- Date Issued: 2015
- Authors: Gqoloqa, Zingisa
- Date: 2015
- Subjects: Life sciences -- Study and teaching (Secondary) -- South Africa -- Eastern Cape , Language and education
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:2028 , http://hdl.handle.net/10962/d1017339
- Description: This research focused on an investigation of the pedagogy and strategies used by Grade 11 Life Sciences teachers when mediating Biodiversity concepts with English second language learners. My interest in this investigation was triggered by the Examiners’ Reports for Life Sciences from 2009 to 2012 which consistently noted learner challenges in answering, interpreting and analysing questions during exams. The reports highlighted learners’ lack of understanding of the questions which led to them providing irrelevant information in their exam scripts. These reports claimed that challenges experienced by these learners could be attributed to language issues experienced by English second language learners. Influenced by these reports, a qualitative case study of two Senior Secondary schools in East London, Eastern Cape South Africa was conducted. Underpinned by an interpretive paradigm and driven by the desire to achieve an in-depth understanding of the case under study, three phases of information gathering were followed. The first phase was that of gathering information through document analysis. Documents were analysed to gain insights and understanding of the issue before conducting interviews. The next phase was that of gathering information through semi-structured interviews followed by classroom observations. Findings from these observations were verified through stimulated recall interviews which provided clarity on the intentionality of choosing a certain method and strategy over another when assisting learners in making meaning of biodiversity concepts. The main findings of this study are that factors which limit learner understanding of biodiversity concepts are a result of a combination of factors such as failure to interpret questions, spelling problems which alter meaning of concepts and an inability to make distinctions among closely related concepts within the topic of Biodiversity. Responding to these factors, teachers demonstrated knowledge of a variety of teaching strategies to support learners. The choice of teaching strategies seemed to be guided by their experiences as well as the challenges they often encounter. Furthermore, teachers’ reflections on their practice provided opportunities for them to identify strengths and limitations of their choice of strategies and possibilities for improvement. It was also noted that factors such as large class sizes, gaps in content knowledge and a lack of detail in chalkboard summary limited the effectiveness of their teaching strategies. The study recommends that: • Teacher-learner ratio needs to be considered for effective support; • There is still a need to capacitate educators in environmental education. In-service training should focus on developing teacher understanding of foundational knowledge in life sciences; and • Teachers need to improve their chalkboard summary skills to increase the level of support that could be provided by comprehensive chalkboard summary through the elaboration of ideas
- Full Text:
- Date Issued: 2015
Effects of ZnO nanohexagons and nanorods on the fluorescence behavior of metallophthalocyanines
- D'Souza, Sarah, Moeno, Sharon, Nyokong, Tebello
- Authors: D'Souza, Sarah , Moeno, Sharon , Nyokong, Tebello
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189741 , vital:44927 , xlink:href="https://doi.org/10.1016/j.poly.2014.09.012"
- Description: This paper looks at the fluorescence behavior of zinc phthalocyanines: 2,(3),9(10),16(17),23(24)-tetrakis- (mercaptoacetic acid phthalocyaninato) zinc(II) (ZnTMAAPc), 2,(3),9(10),16(17),23(24)-tetrakis-(mercaptopropanoic acid phthalocyaninato) zinc(II) (ZnTMPAPc) and (OH)AlPcSmix (the latter contains a mixture of the di-, tri- and tetra-sulfonated derivatives with an average of three sulfonated groups per molecule) in the presence of ZnO nanoparticles. Fluorescence lifetimes of Pc complexes generally decreased in the presence of ZnO nanoparticles, with generally longer lifetimes for ZnO nanohexagons compared to ZnO nanorods.
- Full Text:
- Date Issued: 2015
- Authors: D'Souza, Sarah , Moeno, Sharon , Nyokong, Tebello
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189741 , vital:44927 , xlink:href="https://doi.org/10.1016/j.poly.2014.09.012"
- Description: This paper looks at the fluorescence behavior of zinc phthalocyanines: 2,(3),9(10),16(17),23(24)-tetrakis- (mercaptoacetic acid phthalocyaninato) zinc(II) (ZnTMAAPc), 2,(3),9(10),16(17),23(24)-tetrakis-(mercaptopropanoic acid phthalocyaninato) zinc(II) (ZnTMPAPc) and (OH)AlPcSmix (the latter contains a mixture of the di-, tri- and tetra-sulfonated derivatives with an average of three sulfonated groups per molecule) in the presence of ZnO nanoparticles. Fluorescence lifetimes of Pc complexes generally decreased in the presence of ZnO nanoparticles, with generally longer lifetimes for ZnO nanohexagons compared to ZnO nanorods.
- Full Text:
- Date Issued: 2015
Teaching Mandarin in schools is another slap in the face for African languages
- Kaschula, Russell H, Nosilela, Bulelwa, Heugh, Kathleen, Hendricks, Monica, Maseko, Pamela
- Authors: Kaschula, Russell H , Nosilela, Bulelwa , Heugh, Kathleen , Hendricks, Monica , Maseko, Pamela
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67042 , vital:29023 , https://theconversation.com/teaching-mandarin-in-schools-is-another-slap-in-the-face-for-african-languages-48505
- Description: publisher version , It’s said that behind every powerful language is an army and money. Consider the case of English. In South Africa, as in its other colonies, the British arrived with the Bible in one hand and the breech-loader in the other. Behind them was the English language, military might and money. British missionaries wanted to convert Africa’s indigenous “heathens” to Christianity; to clone little English people on the continent through the medium of English. Next came the Afrikaners, descended from the Dutch. Their slaves created a “kitchen” language out of Dutch and called it Afrikaans. White Afrikaners appropriated it as their own and it became the language of apartheid. One of the tipping points of white rule was the 1976 Soweto uprising – a furious, powerful response to the news that Afrikaans would become a compulsory medium of instruction. Now there is a new potential coloniser on South Africa’s linguistic block. From 2016, Mandarin will be taught in the country’s schools as a Second Additional Language. This new government policy will see African languages bumped even further down the educational pecking order.
- Full Text: false
- Date Issued: 2015
- Authors: Kaschula, Russell H , Nosilela, Bulelwa , Heugh, Kathleen , Hendricks, Monica , Maseko, Pamela
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67042 , vital:29023 , https://theconversation.com/teaching-mandarin-in-schools-is-another-slap-in-the-face-for-african-languages-48505
- Description: publisher version , It’s said that behind every powerful language is an army and money. Consider the case of English. In South Africa, as in its other colonies, the British arrived with the Bible in one hand and the breech-loader in the other. Behind them was the English language, military might and money. British missionaries wanted to convert Africa’s indigenous “heathens” to Christianity; to clone little English people on the continent through the medium of English. Next came the Afrikaners, descended from the Dutch. Their slaves created a “kitchen” language out of Dutch and called it Afrikaans. White Afrikaners appropriated it as their own and it became the language of apartheid. One of the tipping points of white rule was the 1976 Soweto uprising – a furious, powerful response to the news that Afrikaans would become a compulsory medium of instruction. Now there is a new potential coloniser on South Africa’s linguistic block. From 2016, Mandarin will be taught in the country’s schools as a Second Additional Language. This new government policy will see African languages bumped even further down the educational pecking order.
- Full Text: false
- Date Issued: 2015
A roller test bench for the evaluation of automotive vehicle noise, vibration and harshness
- Authors: Raffler, Oliver
- Date: 2015
- Subjects: Motor vehicles -- Transmission devices -- Noise Mechanical engineering Automobiles -- Noise
- Language: English
- Type: Thesis , Masters , MEngineering
- Identifier: http://hdl.handle.net/10948/21646 , vital:29728
- Description: The purpose of this thesis is the construction of a test bench for the assessment of the NVH behaviour of a newly manufactured VW Polo 5. This will be done in collaboration with Volkswagen South Africa. Firstly, in order to gain a better understanding of the requirements such a test bench has to fulfill, the VW Polo, the guidelines prescribed by VW as well as the actual testing procedure implemented by VW Uitenhage will be analysed. Thereafter, the main section of the thesis will deal with the construction of the test bench. As agreed upon with Volkswagen Uitenhage, a test bench will be built during the course of the studies. This test bench will allow stimulation in low frequency as well as high frequency ranges and in addition to that, a second version of the test bench with optimised costing will be derived from the first one. The second model will only allow stimulation in high frequency ranges. During the thesis, a version of the test bench, the RTB-HC, has been developed which enables the stimulation of the high and low frequencies. In addition, a cost optimized version was developed. This version will be referred as RTB-LC. This version allows only a high frequency excitation.
- Full Text:
- Date Issued: 2015
- Authors: Raffler, Oliver
- Date: 2015
- Subjects: Motor vehicles -- Transmission devices -- Noise Mechanical engineering Automobiles -- Noise
- Language: English
- Type: Thesis , Masters , MEngineering
- Identifier: http://hdl.handle.net/10948/21646 , vital:29728
- Description: The purpose of this thesis is the construction of a test bench for the assessment of the NVH behaviour of a newly manufactured VW Polo 5. This will be done in collaboration with Volkswagen South Africa. Firstly, in order to gain a better understanding of the requirements such a test bench has to fulfill, the VW Polo, the guidelines prescribed by VW as well as the actual testing procedure implemented by VW Uitenhage will be analysed. Thereafter, the main section of the thesis will deal with the construction of the test bench. As agreed upon with Volkswagen Uitenhage, a test bench will be built during the course of the studies. This test bench will allow stimulation in low frequency as well as high frequency ranges and in addition to that, a second version of the test bench with optimised costing will be derived from the first one. The second model will only allow stimulation in high frequency ranges. During the thesis, a version of the test bench, the RTB-HC, has been developed which enables the stimulation of the high and low frequencies. In addition, a cost optimized version was developed. This version will be referred as RTB-LC. This version allows only a high frequency excitation.
- Full Text:
- Date Issued: 2015