The relative contribution of non-timber forest products, agriculture and off-farm sources of income to rural households in Koloni and Guquka, Eastern Cape
- Authors: Mtati, Nosiseko
- Date: 2015
- Subjects: Informal sector (Economics) -- South Africa -- Eastern Cape , Rural development -- South Africa -- Eastern Cape , Rural poor -- South Africa -- Eastern Cape , Households -- Economic aspects -- South Africa -- Eastern Cape , Forest products -- South Africa -- Eastern Cape , Non-timber forest products -- South Africa -- Eastern Cape , Agriculture -- Economic aspects -- South Africa -- Eastern Cape , Natural resources -- South Africa -- Eastern Cape , Income -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4785 , http://hdl.handle.net/10962/d1018193
- Description: [Partial abstract]: This study was carried out to determine the contribution of non-timber forest products (NTFPs) to household total income, other livelihood sectors were also examined simultaneously. The contribution of agriculture involved livestock and crop production. Wages and government grants were other livelihood sectors that were looked into. This study was important in determining the change in livelihood strategies in the last decade and to quantify the NTFPs used at the two sites. It was carried out in Guquka and Koloni, both part of the central Eastern Cape. Information on direct use value of the NTFPs used, the quantities and local price; crop production outputs and inputs and the costs. Data were collected via a questionnaire.
- Full Text:
- Date Issued: 2015
- Authors: Mtati, Nosiseko
- Date: 2015
- Subjects: Informal sector (Economics) -- South Africa -- Eastern Cape , Rural development -- South Africa -- Eastern Cape , Rural poor -- South Africa -- Eastern Cape , Households -- Economic aspects -- South Africa -- Eastern Cape , Forest products -- South Africa -- Eastern Cape , Non-timber forest products -- South Africa -- Eastern Cape , Agriculture -- Economic aspects -- South Africa -- Eastern Cape , Natural resources -- South Africa -- Eastern Cape , Income -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4785 , http://hdl.handle.net/10962/d1018193
- Description: [Partial abstract]: This study was carried out to determine the contribution of non-timber forest products (NTFPs) to household total income, other livelihood sectors were also examined simultaneously. The contribution of agriculture involved livestock and crop production. Wages and government grants were other livelihood sectors that were looked into. This study was important in determining the change in livelihood strategies in the last decade and to quantify the NTFPs used at the two sites. It was carried out in Guquka and Koloni, both part of the central Eastern Cape. Information on direct use value of the NTFPs used, the quantities and local price; crop production outputs and inputs and the costs. Data were collected via a questionnaire.
- Full Text:
- Date Issued: 2015
The genetic stock structure and distribution of Chrysoblephus Puniceus, a commercially important transboundary linefish species, endemic to the South West Indian Ocean
- Authors: Duncan, Murray Ian
- Date: 2014
- Subjects: Sparidae , Fishes -- Indian Ocean , Fish populations , Fishery management , Fish stock assessment -- South Africa , Fish stock assessment -- Mozambique , Overfishing , Habitat conservation , Fishes -- Genetics , Fishes -- Climatic factors , Fishes -- Variation , Fishes -- Migration
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5360 , http://hdl.handle.net/10962/d1011868 , Sparidae , Fishes -- Indian Ocean , Fish populations , Fishery management , Fish stock assessment -- South Africa , Fish stock assessment -- Mozambique , Overfishing , Habitat conservation , Fishes -- Genetics , Fishes -- Climatic factors , Fishes -- Variation , Fishes -- Migration
- Description: Chrysoblephus puniceus is an over-exploited linefish species, endemic to the coastlines off southern Mozambique and eastern South Africa. Over-exploitation and habitat loss are two of the biggest threats to the sustainability of fisheries globally. Assessing the genetic stock structure (a prerequisite for effective management) and predicting climate related range changes will provide a better understanding of these threats to C. puniceus which can be used to improve the sustainability of the fishery. Two hundred and eighty four genetic samples were collected from eight sampling sites between Ponta da Barra in Mozambique and Coffee Bay in South Africa. The mitochondrial control region and ten microsatellite loci were amplified to analyse the stock structure of C. puniceus. The majority of microsatellite and mtDNA pairwise population comparisons were not significant (P > 0.05) although Xai Xai and Inhaca populations had some significant population comparisons for mtDNA (P < 0.05). AMOVA did not explain any significant variation at the between groups hierarchical level for any pre-defined groupings except for a mtDNA grouping which separated out Xai Xai and Inhaca from other sampling sites. SAMOVA, isolation by distance tests, structure analysis, principle component analysis and spatial autocorrelation analysis all indicated a single population of C. puniceus as being most likely. The migrate-n analysis provided evidence of current driven larval transport, with net migration rates influenced by current dynamics.Two hundred and thirty six unique presence points of C. puniceus were correlated with seasonal maximum and minimum temperature data and bathymetry to model the current distribution and predict future distribution changes of the species up until 2030. Eight individual species distribution models were developed and combined into a mean ensemble model using the Biomod2 package. Winter minimum temperature was the most important variable in determining models outputs. Overall the ensemble model was accurate with a true skills statistic score of 0.962. Binary transformed mean ensemble models predicted a northern and southern range contraction of C. puniceus' distribution of 15 percent; by 2030. The mean ensemble probability of occurrence models indicated that C. puniceus' abundance is likely to decrease off the southern Mozambique coastline but remain high off KwaZulu-Natal. The results of the genetic analysis support the theory of external recruitment sustaining the KwaZulu Natal fishery for C. puniceus. While the high genetic diversity and connectivity may make C. puniceus more resilient to disturbances, the loss of 15 percent; distribution and 11 percent; genetic diversity by 2030 will increase the species vulnerability. The decrease in abundance of C. puniceus off southern Mozambique together with current widespread exploitation levels could result in the collapse of the fishery. A single transboundary stock of C. puniceus highlights the need for co-management of the species. A combined stock assessment between South Africa and Mozambique and the development of further Marine Protected Areas off southern Mozambique are suggested as management options to minimise the vulnerability of this species.
- Full Text:
- Date Issued: 2014
- Authors: Duncan, Murray Ian
- Date: 2014
- Subjects: Sparidae , Fishes -- Indian Ocean , Fish populations , Fishery management , Fish stock assessment -- South Africa , Fish stock assessment -- Mozambique , Overfishing , Habitat conservation , Fishes -- Genetics , Fishes -- Climatic factors , Fishes -- Variation , Fishes -- Migration
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5360 , http://hdl.handle.net/10962/d1011868 , Sparidae , Fishes -- Indian Ocean , Fish populations , Fishery management , Fish stock assessment -- South Africa , Fish stock assessment -- Mozambique , Overfishing , Habitat conservation , Fishes -- Genetics , Fishes -- Climatic factors , Fishes -- Variation , Fishes -- Migration
- Description: Chrysoblephus puniceus is an over-exploited linefish species, endemic to the coastlines off southern Mozambique and eastern South Africa. Over-exploitation and habitat loss are two of the biggest threats to the sustainability of fisheries globally. Assessing the genetic stock structure (a prerequisite for effective management) and predicting climate related range changes will provide a better understanding of these threats to C. puniceus which can be used to improve the sustainability of the fishery. Two hundred and eighty four genetic samples were collected from eight sampling sites between Ponta da Barra in Mozambique and Coffee Bay in South Africa. The mitochondrial control region and ten microsatellite loci were amplified to analyse the stock structure of C. puniceus. The majority of microsatellite and mtDNA pairwise population comparisons were not significant (P > 0.05) although Xai Xai and Inhaca populations had some significant population comparisons for mtDNA (P < 0.05). AMOVA did not explain any significant variation at the between groups hierarchical level for any pre-defined groupings except for a mtDNA grouping which separated out Xai Xai and Inhaca from other sampling sites. SAMOVA, isolation by distance tests, structure analysis, principle component analysis and spatial autocorrelation analysis all indicated a single population of C. puniceus as being most likely. The migrate-n analysis provided evidence of current driven larval transport, with net migration rates influenced by current dynamics.Two hundred and thirty six unique presence points of C. puniceus were correlated with seasonal maximum and minimum temperature data and bathymetry to model the current distribution and predict future distribution changes of the species up until 2030. Eight individual species distribution models were developed and combined into a mean ensemble model using the Biomod2 package. Winter minimum temperature was the most important variable in determining models outputs. Overall the ensemble model was accurate with a true skills statistic score of 0.962. Binary transformed mean ensemble models predicted a northern and southern range contraction of C. puniceus' distribution of 15 percent; by 2030. The mean ensemble probability of occurrence models indicated that C. puniceus' abundance is likely to decrease off the southern Mozambique coastline but remain high off KwaZulu-Natal. The results of the genetic analysis support the theory of external recruitment sustaining the KwaZulu Natal fishery for C. puniceus. While the high genetic diversity and connectivity may make C. puniceus more resilient to disturbances, the loss of 15 percent; distribution and 11 percent; genetic diversity by 2030 will increase the species vulnerability. The decrease in abundance of C. puniceus off southern Mozambique together with current widespread exploitation levels could result in the collapse of the fishery. A single transboundary stock of C. puniceus highlights the need for co-management of the species. A combined stock assessment between South Africa and Mozambique and the development of further Marine Protected Areas off southern Mozambique are suggested as management options to minimise the vulnerability of this species.
- Full Text:
- Date Issued: 2014
COIN : a customisable, incentive driven video on demand framework for low-cost IPTV services
- Authors: Musvibe, Ray
- Date: 2012 , 2012-03-02
- Subjects: Internet television , Digital television , Television broadcasting -- Technological innovations , Multicasting (Computer networks) , Video dial tone , Open source software , Telecommunication , Capital investments
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4654 , http://hdl.handle.net/10962/d1006650 , Internet television , Digital television , Television broadcasting -- Technological innovations , Multicasting (Computer networks) , Video dial tone , Open source software , Telecommunication , Capital investments
- Description: There has been a significant rise in the provision of television and video services over IP (IPTV) in recent years. Increasing network capacity and falling bandwidth costs have made it both technically and economically feasible for service providers to deliver IPTV services. Several telecommunications (telco) operators worldwide are rolling out IPTV solutions and view IPTV as a major service differentiator and alternative revenue source. The main challenge that IPTV providers currently face, however, is the increasingly congested television service provider market, which also includes Internet Television. IPTV solutions therefore need strong service differentiators to succeed. IPTV solutions can doubtlessly sell much faster if they are more affordable or low-cost. Advertising has already been used in many service sectors to help lower service costs, including traditional broadcast television. This thesis therefore explores the role that advertising can play in helping to lower the cost of IPTV services and to incentivise IPTV billing. Another approach that IPTV providers can use to help sell their product is by addressing the growing need for control by today's multimedia users. This thesis will therefore explore the varied approaches that can be used to achieve viewer focused IPTV implementations. To further lower the cost of IPTV services, telcos can also turn to low-cost, open source platforms for service delivery. The adoption of low-cost infrastructure by telcos can lead to reduced Capital Expenditure (CAPEX), which in turn can lead to lower service fees, and ultimately to higher subscriptions and revenue. Therefore, in this thesis, the author proposes a CustOmisable, INcentive (COIN) driven Video on Demand (VoD) framework to be developed and deployed using the Mobicents Communication Platform, an open source service creation and execution platform. The COIN framework aims to provide a viewer focused, economically competitive service that combines the potential cost savings of using free and open source software (FOSS), with an innovative, incentive-driven billing approach. This project will also aim to evaluate whether the Mobicents Platform is a suitable service creation and execution platform for the proposed framework. Additionally, the proposed implementation aims to be interoperable with other IPTV implementations, hence shall follow current IPTV standardisation architectures and trends. The service testbed and its implementation are described in detail and only free and open source software is used; this is to enable its easy duplication and extension for future research. , TeX output 2012.03.02:1241 , Adobe Acrobat 9.2 Paper Capture Plug-in
- Full Text:
- Date Issued: 2012
- Authors: Musvibe, Ray
- Date: 2012 , 2012-03-02
- Subjects: Internet television , Digital television , Television broadcasting -- Technological innovations , Multicasting (Computer networks) , Video dial tone , Open source software , Telecommunication , Capital investments
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4654 , http://hdl.handle.net/10962/d1006650 , Internet television , Digital television , Television broadcasting -- Technological innovations , Multicasting (Computer networks) , Video dial tone , Open source software , Telecommunication , Capital investments
- Description: There has been a significant rise in the provision of television and video services over IP (IPTV) in recent years. Increasing network capacity and falling bandwidth costs have made it both technically and economically feasible for service providers to deliver IPTV services. Several telecommunications (telco) operators worldwide are rolling out IPTV solutions and view IPTV as a major service differentiator and alternative revenue source. The main challenge that IPTV providers currently face, however, is the increasingly congested television service provider market, which also includes Internet Television. IPTV solutions therefore need strong service differentiators to succeed. IPTV solutions can doubtlessly sell much faster if they are more affordable or low-cost. Advertising has already been used in many service sectors to help lower service costs, including traditional broadcast television. This thesis therefore explores the role that advertising can play in helping to lower the cost of IPTV services and to incentivise IPTV billing. Another approach that IPTV providers can use to help sell their product is by addressing the growing need for control by today's multimedia users. This thesis will therefore explore the varied approaches that can be used to achieve viewer focused IPTV implementations. To further lower the cost of IPTV services, telcos can also turn to low-cost, open source platforms for service delivery. The adoption of low-cost infrastructure by telcos can lead to reduced Capital Expenditure (CAPEX), which in turn can lead to lower service fees, and ultimately to higher subscriptions and revenue. Therefore, in this thesis, the author proposes a CustOmisable, INcentive (COIN) driven Video on Demand (VoD) framework to be developed and deployed using the Mobicents Communication Platform, an open source service creation and execution platform. The COIN framework aims to provide a viewer focused, economically competitive service that combines the potential cost savings of using free and open source software (FOSS), with an innovative, incentive-driven billing approach. This project will also aim to evaluate whether the Mobicents Platform is a suitable service creation and execution platform for the proposed framework. Additionally, the proposed implementation aims to be interoperable with other IPTV implementations, hence shall follow current IPTV standardisation architectures and trends. The service testbed and its implementation are described in detail and only free and open source software is used; this is to enable its easy duplication and extension for future research. , TeX output 2012.03.02:1241 , Adobe Acrobat 9.2 Paper Capture Plug-in
- Full Text:
- Date Issued: 2012
The design and synthesis of multidentate N-heterocyclic carbenes as metathesis catalyst ligands
- Authors: Truscott, Byron John
- Date: 2011
- Subjects: Carbenes (Methylene compounds) , Heterocyclic compounds , Ligands , Ligands -- Design , Metathesis (Chemistry) , Catalysis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4304 , http://hdl.handle.net/10962/d1004962 , Carbenes (Methylene compounds) , Heterocyclic compounds , Ligands , Ligands -- Design , Metathesis (Chemistry) , Catalysis
- Description: This study has focused on the design and preparation of bi– and tridentate N–Heterocyclic Carbene (NHC) ligands in order to investigate the effect of a multidentate approach to the formation, stability and catalytic activity of coordination complexes. Chapters 1 – 3 provide background information of relevant catalysis, carbene and coordination chemistry, followed by previous work performed within our research group. In Chapter 4 attention is given to the synthetic aspects of the research conducted, comprising two distinct approaches to the preparation of unsymmetrical saturated and unsaturated NHCs. Firstly, an investigation of the saturated NHC ligands yielded three novel, unsymmetrical pro–ligands, viz., two halopropyl imidazolinium salts and a bidentate hydroxypropyl imidazolinium salt. Secondly, eight imidazolium salts have been generated, including a hydroxypropyl analogue and novel decyl and tridentate malonyl derivatives. These compounds were prepared using microwave–assisted methodology for the alkylation of N– mesitylimidazole – an approach that drastically reduced reaction times (from 8 hours – 7 days to ca. 0.5 – 2 hours) and facilitated isolation of the imidazolium salts. Many of the compounds prepared in this study are novel and were fully characterized using HRMS and 1– and 2–D NMR analysis. Coordination studies using a selection of the prepared pro–ligands afforded an alkoxy–NHC silver derivative and four novel Ru–complexes, viz., Grubbs II–type Ru–complexes containing:– chloropropyl imidazolinylidene; propenyl imidazolylidene; and bidentate alkoxypropyl imidazolylidene ligands. Furthermore, a well–defined benzyl mesitylimidazolylidene Ru–complex has been isolated, which exhibited good stability in air. DFT–level geometry–optimization studies, using the Accelrys DMol3 package have given valuable insights into the likely geometries of the prepared and putative catalysts.
- Full Text:
- Date Issued: 2011
- Authors: Truscott, Byron John
- Date: 2011
- Subjects: Carbenes (Methylene compounds) , Heterocyclic compounds , Ligands , Ligands -- Design , Metathesis (Chemistry) , Catalysis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4304 , http://hdl.handle.net/10962/d1004962 , Carbenes (Methylene compounds) , Heterocyclic compounds , Ligands , Ligands -- Design , Metathesis (Chemistry) , Catalysis
- Description: This study has focused on the design and preparation of bi– and tridentate N–Heterocyclic Carbene (NHC) ligands in order to investigate the effect of a multidentate approach to the formation, stability and catalytic activity of coordination complexes. Chapters 1 – 3 provide background information of relevant catalysis, carbene and coordination chemistry, followed by previous work performed within our research group. In Chapter 4 attention is given to the synthetic aspects of the research conducted, comprising two distinct approaches to the preparation of unsymmetrical saturated and unsaturated NHCs. Firstly, an investigation of the saturated NHC ligands yielded three novel, unsymmetrical pro–ligands, viz., two halopropyl imidazolinium salts and a bidentate hydroxypropyl imidazolinium salt. Secondly, eight imidazolium salts have been generated, including a hydroxypropyl analogue and novel decyl and tridentate malonyl derivatives. These compounds were prepared using microwave–assisted methodology for the alkylation of N– mesitylimidazole – an approach that drastically reduced reaction times (from 8 hours – 7 days to ca. 0.5 – 2 hours) and facilitated isolation of the imidazolium salts. Many of the compounds prepared in this study are novel and were fully characterized using HRMS and 1– and 2–D NMR analysis. Coordination studies using a selection of the prepared pro–ligands afforded an alkoxy–NHC silver derivative and four novel Ru–complexes, viz., Grubbs II–type Ru–complexes containing:– chloropropyl imidazolinylidene; propenyl imidazolylidene; and bidentate alkoxypropyl imidazolylidene ligands. Furthermore, a well–defined benzyl mesitylimidazolylidene Ru–complex has been isolated, which exhibited good stability in air. DFT–level geometry–optimization studies, using the Accelrys DMol3 package have given valuable insights into the likely geometries of the prepared and putative catalysts.
- Full Text:
- Date Issued: 2011
Determination of the botanical composition of black rhinoceros (Diceros bicornis) dung using the rbcL gene as a molecular marker, and analysis of antioxidant and phenolic content of its browse
- Authors: Bulani, Siyavuya Ishmael
- Date: 2007 , 2013-06-25
- Subjects: Black rhinoceros -- Food , Black rhinoceros -- South Africa -- Eastern Cape , Browse (Animal food) -- Analysis -- South Africa -- Eastern Cape , Plant ecology -- South Africa -- Eastern Cape , Genetic markers , Black rhinoceros -- Manure -- Analysis , Phenols , Antioxidants
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4070 , http://hdl.handle.net/10962/d1006468 , Black rhinoceros -- Food , Black rhinoceros -- South Africa -- Eastern Cape , Browse (Animal food) -- Analysis -- South Africa -- Eastern Cape , Plant ecology -- South Africa -- Eastern Cape , Genetic markers , Black rhinoceros -- Manure -- Analysis , Phenols , Antioxidants
- Description: The black rhinoceros remains one of the world's extremely endangered species despite a variety of policies to protect it. The black rhinoceros population at the Great Fish River Reserve (GFRR) in the Eastern Cape in South Africa has increased steadily since their re-introduction in 1986. This megaherbivore is a browser, with a diet obtained largely from the short and medium succulent thicket of the GFRR. Knowledge of the preferential diet of the black rhinoceros on the reserve is an important factor for the effective management of the land and the herbivores that compete for its resources. The dietary preferences of the black rhinoceros at the reserve have been established using backtracking methods. In this study the rbcL gene was used to establish an rbcL gene database of the plants from the GFRR and determine the botanical composition of the black rhinoceros dung from the GFRR. Due to the limited number of rbcL gene plant sequences from the GFRR deposited in the GenBank database, 18 plant species from the GFRR were sequenced. Sequence analyses between the partial rbcL gene sequences generated were able to distinguish between plants down to species level. Plant species from the family Euphorbiaceae and Fabaceae showed sequence variation at intra-specific level compared to those of Tiliaceae which were more conserved. The generated rbcL gene sequences from seasonal dung samples were compared to the rbcL gene sequenced from 18 plant species obtained from the GFRR and those from the GenBank database. A wide range of plant species were identified from the dung samples. There were no major differences in botanical composition between the dung samples, except that Grewia spp. were found to dominate in almost all seasons. The results obtained on the free radical scavenging activity of the extracts against 2,2-Diphenyl-l-picrylhydrazyl (DPPH) increased in the order of methanol > ethyl acetate > chloroform. The DPPH free radical scavenging activity of the methanol plant extracts increased in the order Brachylaena elliptica > Plumbago auriculata > Grewia robusta > Azima tetracantha. Methanol extracts on the TLC plate sprayed with Fe³⁺-2,4,6-Tri-2-pyridyl-s-triazine (TPTZ) showed that the compounds present in the extracts react differently to ferric ion, with most compounds unable to reduce ferric ion. Furthermore the methanol extracts were able to exhibit reduction potentials vs. Ag/AgCl at low concentrations. The compounds in the extracts were shown to be phenolic acids and flavonoid glycosides.
- Full Text:
- Date Issued: 2007
- Authors: Bulani, Siyavuya Ishmael
- Date: 2007 , 2013-06-25
- Subjects: Black rhinoceros -- Food , Black rhinoceros -- South Africa -- Eastern Cape , Browse (Animal food) -- Analysis -- South Africa -- Eastern Cape , Plant ecology -- South Africa -- Eastern Cape , Genetic markers , Black rhinoceros -- Manure -- Analysis , Phenols , Antioxidants
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4070 , http://hdl.handle.net/10962/d1006468 , Black rhinoceros -- Food , Black rhinoceros -- South Africa -- Eastern Cape , Browse (Animal food) -- Analysis -- South Africa -- Eastern Cape , Plant ecology -- South Africa -- Eastern Cape , Genetic markers , Black rhinoceros -- Manure -- Analysis , Phenols , Antioxidants
- Description: The black rhinoceros remains one of the world's extremely endangered species despite a variety of policies to protect it. The black rhinoceros population at the Great Fish River Reserve (GFRR) in the Eastern Cape in South Africa has increased steadily since their re-introduction in 1986. This megaherbivore is a browser, with a diet obtained largely from the short and medium succulent thicket of the GFRR. Knowledge of the preferential diet of the black rhinoceros on the reserve is an important factor for the effective management of the land and the herbivores that compete for its resources. The dietary preferences of the black rhinoceros at the reserve have been established using backtracking methods. In this study the rbcL gene was used to establish an rbcL gene database of the plants from the GFRR and determine the botanical composition of the black rhinoceros dung from the GFRR. Due to the limited number of rbcL gene plant sequences from the GFRR deposited in the GenBank database, 18 plant species from the GFRR were sequenced. Sequence analyses between the partial rbcL gene sequences generated were able to distinguish between plants down to species level. Plant species from the family Euphorbiaceae and Fabaceae showed sequence variation at intra-specific level compared to those of Tiliaceae which were more conserved. The generated rbcL gene sequences from seasonal dung samples were compared to the rbcL gene sequenced from 18 plant species obtained from the GFRR and those from the GenBank database. A wide range of plant species were identified from the dung samples. There were no major differences in botanical composition between the dung samples, except that Grewia spp. were found to dominate in almost all seasons. The results obtained on the free radical scavenging activity of the extracts against 2,2-Diphenyl-l-picrylhydrazyl (DPPH) increased in the order of methanol > ethyl acetate > chloroform. The DPPH free radical scavenging activity of the methanol plant extracts increased in the order Brachylaena elliptica > Plumbago auriculata > Grewia robusta > Azima tetracantha. Methanol extracts on the TLC plate sprayed with Fe³⁺-2,4,6-Tri-2-pyridyl-s-triazine (TPTZ) showed that the compounds present in the extracts react differently to ferric ion, with most compounds unable to reduce ferric ion. Furthermore the methanol extracts were able to exhibit reduction potentials vs. Ag/AgCl at low concentrations. The compounds in the extracts were shown to be phenolic acids and flavonoid glycosides.
- Full Text:
- Date Issued: 2007
A framework for responsive content adaptation in electronic display networks
- Authors: West, Philip
- Date: 2006
- Subjects: Computer networks , Cell phone systems , Wireless communication systems , Mobile communication systems , HTML (Document markup language) , XML (Document markup language)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4589 , http://hdl.handle.net/10962/d1004824 , Computer networks , Cell phone systems , Wireless communication systems , Mobile communication systems , HTML (Document markup language) , XML (Document markup language)
- Description: Recent trends show an increase in the availability and functionality of handheld devices, wireless network technology, and electronic display networks. We propose the novel integration of these technologies to provide wireless access to content delivered to large-screen display systems. Content adaptation is used as a method of reformatting web pages to display more appropriately on handheld devices, and to remove unwanted content. A framework is presented that facilitates content adaptation, implemented as an adaptation layer, which is extended to provide personalization of adaptation settings and response to network conditions. The framework is implemented as a proxy server for a wireless network, and handles HTML and XML documents. Once a document has been requested by a user, the HTML/XML is retrieved and parsed, creating a Document Object Model tree representation. It is then altered according to the user’s personal settings or predefined settings, based on current network usage and the network resources available. Three adaptation techniques were implemented; spatial representation, which generates an image map of the document, text summarization, which creates a tree view representation of a document, and tag extraction, which replaces specific tags with links. Three proof-of-concept systems were developed in order to test the robustness of the framework. A system for use with digital slide shows, a digital signage system, and a generalized system for use with the internet were implemented. Testing was performed by accessing sample web pages through the content adaptation proxy server. Tag extraction works correctly for all HTML and XML document structures, whereas spatial representation and text summarization are limited to a controlled subset. Results indicate that the adaptive system has the ability to reduce average bandwidth usage, by decreasing the amount of data on the network, thereby allowing a greater number of users access to content. This suggests that responsive content adaptation has a positive influence on network performance metrics.
- Full Text:
- Date Issued: 2006
- Authors: West, Philip
- Date: 2006
- Subjects: Computer networks , Cell phone systems , Wireless communication systems , Mobile communication systems , HTML (Document markup language) , XML (Document markup language)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4589 , http://hdl.handle.net/10962/d1004824 , Computer networks , Cell phone systems , Wireless communication systems , Mobile communication systems , HTML (Document markup language) , XML (Document markup language)
- Description: Recent trends show an increase in the availability and functionality of handheld devices, wireless network technology, and electronic display networks. We propose the novel integration of these technologies to provide wireless access to content delivered to large-screen display systems. Content adaptation is used as a method of reformatting web pages to display more appropriately on handheld devices, and to remove unwanted content. A framework is presented that facilitates content adaptation, implemented as an adaptation layer, which is extended to provide personalization of adaptation settings and response to network conditions. The framework is implemented as a proxy server for a wireless network, and handles HTML and XML documents. Once a document has been requested by a user, the HTML/XML is retrieved and parsed, creating a Document Object Model tree representation. It is then altered according to the user’s personal settings or predefined settings, based on current network usage and the network resources available. Three adaptation techniques were implemented; spatial representation, which generates an image map of the document, text summarization, which creates a tree view representation of a document, and tag extraction, which replaces specific tags with links. Three proof-of-concept systems were developed in order to test the robustness of the framework. A system for use with digital slide shows, a digital signage system, and a generalized system for use with the internet were implemented. Testing was performed by accessing sample web pages through the content adaptation proxy server. Tag extraction works correctly for all HTML and XML document structures, whereas spatial representation and text summarization are limited to a controlled subset. Results indicate that the adaptive system has the ability to reduce average bandwidth usage, by decreasing the amount of data on the network, thereby allowing a greater number of users access to content. This suggests that responsive content adaptation has a positive influence on network performance metrics.
- Full Text:
- Date Issued: 2006
Development of nickel-selective molecularly imprinted polymers
- Tshikhudo, Tshinyadzo Robert
- Authors: Tshikhudo, Tshinyadzo Robert
- Date: 2002 , 2013-07-25
- Subjects: Imprinted polymers , Imprinted polymers -- Synthesis , Molecular imprinting , Nickel , Nickel -- Metallurgy
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4292 , http://hdl.handle.net/10962/d1004449 , Imprinted polymers , Imprinted polymers -- Synthesis , Molecular imprinting , Nickel , Nickel -- Metallurgy
- Description: A series of eight novel bidentate ligands, designed for use in the construction of nickel-selective molecularly imprinted polymers (MIP's), have been prepared. The synthetic pathway was established by retrosynthetic analysis of the target molecules to the readily available precursors, pyridine-2-carbaldehyde (or 6-methylpyridine-2-carbaldehyde) and ethyl bromoacetate. The ligands were designed to contain an allyl group for co-polymerisation and amine and pyridyl nitrogen donors, located to permit the formation of 5-membered nickel chelates. The eight novel ligands and their respective precursors were characterized by elemental (high-resolution MS) and spectroscopic (IR and ¹H and ¹³C NMR) analysis. High resolution electron-impact mass spectrometry has also been used, together with B/E linked scan data, to explore the fragmentation patterns of selected ligands. The various nickel(ll) complexes were analyzed using spectroscopic techniques and, in some cases, elemental analysis; computer modelling has also been used to explore conformational effects and complex stability. Numerous MIP's, containing nickel(II) complexes of the bidentate ligands, have been prepared, using ethylene glycol dimethylacrylate (EGDMA) as the cross-linker, azobis(isobutyronitrile) (AlBN) as the polymerization initiator and MeOH as the porogenic solvent. The template nickel(II) ions were leached out with conc. HCI, and the nickel(II) selectivity [in the presence of Fe(Ill)] of the nickel-imprinted polymers was examined by ICP-MS analysis. The ICP-MS data indicate that the MIP's examined exhibit extremely high selectivity for nickel over iron. , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
- Date Issued: 2002
- Authors: Tshikhudo, Tshinyadzo Robert
- Date: 2002 , 2013-07-25
- Subjects: Imprinted polymers , Imprinted polymers -- Synthesis , Molecular imprinting , Nickel , Nickel -- Metallurgy
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4292 , http://hdl.handle.net/10962/d1004449 , Imprinted polymers , Imprinted polymers -- Synthesis , Molecular imprinting , Nickel , Nickel -- Metallurgy
- Description: A series of eight novel bidentate ligands, designed for use in the construction of nickel-selective molecularly imprinted polymers (MIP's), have been prepared. The synthetic pathway was established by retrosynthetic analysis of the target molecules to the readily available precursors, pyridine-2-carbaldehyde (or 6-methylpyridine-2-carbaldehyde) and ethyl bromoacetate. The ligands were designed to contain an allyl group for co-polymerisation and amine and pyridyl nitrogen donors, located to permit the formation of 5-membered nickel chelates. The eight novel ligands and their respective precursors were characterized by elemental (high-resolution MS) and spectroscopic (IR and ¹H and ¹³C NMR) analysis. High resolution electron-impact mass spectrometry has also been used, together with B/E linked scan data, to explore the fragmentation patterns of selected ligands. The various nickel(ll) complexes were analyzed using spectroscopic techniques and, in some cases, elemental analysis; computer modelling has also been used to explore conformational effects and complex stability. Numerous MIP's, containing nickel(II) complexes of the bidentate ligands, have been prepared, using ethylene glycol dimethylacrylate (EGDMA) as the cross-linker, azobis(isobutyronitrile) (AlBN) as the polymerization initiator and MeOH as the porogenic solvent. The template nickel(II) ions were leached out with conc. HCI, and the nickel(II) selectivity [in the presence of Fe(Ill)] of the nickel-imprinted polymers was examined by ICP-MS analysis. The ICP-MS data indicate that the MIP's examined exhibit extremely high selectivity for nickel over iron. , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
- Date Issued: 2002
An exploration of the factors which promote and impede correctional supervision effectiveness with regard to the juvenile or youth offenders
- Authors: Van Zyl, Claudette
- Date: 1999
- Subjects: Juvenile corrections , Juvenile delinquency , Juvenile delinquents. , Social work with juvenile delinquents
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:709 , http://hdl.handle.net/10962/d1006529 , Juvenile corrections , Juvenile delinquency , Juvenile delinquents. , Social work with juvenile delinquents
- Description: Youth Crime is increasing at an alarming rate and imprisonment as the only measure of punishment has become a contentious issue for the South African Correctional Services. National and international awareness has been raised about young people at risk in the 1992 campaign" Justice for the children: No child should be caged". In the words of Ruth Morris: " Prisons are not the greatest. They breed bitterness and crime, destroy people who work and live in them and its not nice to cage your fellow human beings. Prisons cost more than the best university education, while giving appalling results". (1993 (1) SA 476). The question that needs to be asked is whether imprisonment really does effect the punitive motives of deterrence, retribution, protecting the community and rehabilitation of the offender. The introduction of correctional supervision as a sentencing option has ushered in a new phase in our criminal justice system. The South African Model of correctional supervision is described as a community-based sentence that is served within the community and the probationer is subject to stringent conditions such as house arrest, community service, monitoring and the attendance of treatment programmes. The study aimed to: * identify the variables that appear to be operating in determining the successful and or unsuccessful correctional supervision sentences with young offenders; (the terms effectiveness and successful are used interchangeably). * contribute to a better understanding of working with young offenders in the community and to make positive recommendations concerning their rehabilitation. The design applied in this study was the exploratory-descriptive design. It was exploratory since the field of correctional supervision at this stage is not well developed and descriptive because the researcher described features of this phenomenon. This was combined with an empirical investigation that explored the youths experience on correctional supervision. Another component of the empirical investigation consisted of how the parents or significant other as well as the supervision committee perceived the respondents adjustment on correctional supervision. The findings of the empirical investigation clearly showed that although the respondents found house arrest extremely difficult to comply with, their overall functioning and adjustment in the community was positive. Factors that emerged from the study that can promote a successful correctional supervision sentence were factors such as positive support systems that can instill discipline, no involvement in gangsterism, no family pathologies such as alcoholism, family violence and financial problems. Factors such as negative attitude of staff members, familial problems, stringent house arrest conditions, financial problems impeded the youths functioning on correctional supervision. The correctional social worker together with the multi-disciplinary team both have a cardinal role to play in the treatment of the young offender. The various professions with their expertise have a major role to play in the treatment programmes geared to assist the young offender to reintegrate and function positively in the community
- Full Text:
- Date Issued: 1999
- Authors: Van Zyl, Claudette
- Date: 1999
- Subjects: Juvenile corrections , Juvenile delinquency , Juvenile delinquents. , Social work with juvenile delinquents
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:709 , http://hdl.handle.net/10962/d1006529 , Juvenile corrections , Juvenile delinquency , Juvenile delinquents. , Social work with juvenile delinquents
- Description: Youth Crime is increasing at an alarming rate and imprisonment as the only measure of punishment has become a contentious issue for the South African Correctional Services. National and international awareness has been raised about young people at risk in the 1992 campaign" Justice for the children: No child should be caged". In the words of Ruth Morris: " Prisons are not the greatest. They breed bitterness and crime, destroy people who work and live in them and its not nice to cage your fellow human beings. Prisons cost more than the best university education, while giving appalling results". (1993 (1) SA 476). The question that needs to be asked is whether imprisonment really does effect the punitive motives of deterrence, retribution, protecting the community and rehabilitation of the offender. The introduction of correctional supervision as a sentencing option has ushered in a new phase in our criminal justice system. The South African Model of correctional supervision is described as a community-based sentence that is served within the community and the probationer is subject to stringent conditions such as house arrest, community service, monitoring and the attendance of treatment programmes. The study aimed to: * identify the variables that appear to be operating in determining the successful and or unsuccessful correctional supervision sentences with young offenders; (the terms effectiveness and successful are used interchangeably). * contribute to a better understanding of working with young offenders in the community and to make positive recommendations concerning their rehabilitation. The design applied in this study was the exploratory-descriptive design. It was exploratory since the field of correctional supervision at this stage is not well developed and descriptive because the researcher described features of this phenomenon. This was combined with an empirical investigation that explored the youths experience on correctional supervision. Another component of the empirical investigation consisted of how the parents or significant other as well as the supervision committee perceived the respondents adjustment on correctional supervision. The findings of the empirical investigation clearly showed that although the respondents found house arrest extremely difficult to comply with, their overall functioning and adjustment in the community was positive. Factors that emerged from the study that can promote a successful correctional supervision sentence were factors such as positive support systems that can instill discipline, no involvement in gangsterism, no family pathologies such as alcoholism, family violence and financial problems. Factors such as negative attitude of staff members, familial problems, stringent house arrest conditions, financial problems impeded the youths functioning on correctional supervision. The correctional social worker together with the multi-disciplinary team both have a cardinal role to play in the treatment of the young offender. The various professions with their expertise have a major role to play in the treatment programmes geared to assist the young offender to reintegrate and function positively in the community
- Full Text:
- Date Issued: 1999
The significance of unconformities in the development of Witwatersrand gold and uranium placers
- Authors: Beater, Christian Douglas
- Date: 1983 , 2013-04-03
- Subjects: Placer deposits , Gold ores -- Geology -- South Africa -- Witwatersrand , Uranium ores -- Geology -- South Africa -- Witwatersrand
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4925 , http://hdl.handle.net/10962/d1004535 , Placer deposits , Gold ores -- Geology -- South Africa -- Witwatersrand , Uranium ores -- Geology -- South Africa -- Witwatersrand
- Description: Most of the economic gold and uranium placers are developed on low angle disconformities in the Central Rand Group and concentrations of gold and uranium are usually at their optimum on unconformity surfaces. Examples include the Kimberley Reef and South Reef of the East Rand, the Main Reef Leader of the Central Rand, the Carbon Leader of the Carletonville goldfield, the Vaal Reef of the Klerksdorp goldfield and the Basal/Steyn placers of the Welkom goldfield. The individual goldfields represent fluvial fans which are composed of a large number of tectonogenetic sedimentary packages separated by unconformities. The tectonic responses between cycles of sedimentation produced unconformities and tectonically controlled cyclic sedimentation is one of the key factors culminating in the preparation and deposition of auriferous placers within the Witwatersrand succession. Unconformities, which represent breaks in sedimentation, result in the preconditioning of palaeosurfaces and redistribution of sediments and heavy minerals on them. Winnowing of sands produced heavy mineral residual accumulations on erosion surfaces which were generally preserved by small-pebble lags or algal mats. Reworking of units truncated by the unconformities provided additional gold, uranium and heavy minerals to unconformity surfaces.
- Full Text:
- Date Issued: 1983
- Authors: Beater, Christian Douglas
- Date: 1983 , 2013-04-03
- Subjects: Placer deposits , Gold ores -- Geology -- South Africa -- Witwatersrand , Uranium ores -- Geology -- South Africa -- Witwatersrand
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4925 , http://hdl.handle.net/10962/d1004535 , Placer deposits , Gold ores -- Geology -- South Africa -- Witwatersrand , Uranium ores -- Geology -- South Africa -- Witwatersrand
- Description: Most of the economic gold and uranium placers are developed on low angle disconformities in the Central Rand Group and concentrations of gold and uranium are usually at their optimum on unconformity surfaces. Examples include the Kimberley Reef and South Reef of the East Rand, the Main Reef Leader of the Central Rand, the Carbon Leader of the Carletonville goldfield, the Vaal Reef of the Klerksdorp goldfield and the Basal/Steyn placers of the Welkom goldfield. The individual goldfields represent fluvial fans which are composed of a large number of tectonogenetic sedimentary packages separated by unconformities. The tectonic responses between cycles of sedimentation produced unconformities and tectonically controlled cyclic sedimentation is one of the key factors culminating in the preparation and deposition of auriferous placers within the Witwatersrand succession. Unconformities, which represent breaks in sedimentation, result in the preconditioning of palaeosurfaces and redistribution of sediments and heavy minerals on them. Winnowing of sands produced heavy mineral residual accumulations on erosion surfaces which were generally preserved by small-pebble lags or algal mats. Reworking of units truncated by the unconformities provided additional gold, uranium and heavy minerals to unconformity surfaces.
- Full Text:
- Date Issued: 1983
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