Developing a cross platform IMS client using the JAIN SIP applet phone
- Authors: Muswera, Walter Tawanda
- Date: 2015
- Subjects: Internet Protocol multimedia subsystem , Java (Computer program language)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4712 , http://hdl.handle.net/10962/d1017934
- Description: Since the introduction of the IP Multimedia Subsystem (IMS) by the Third Generation Partnership Project (3GPP) in 2002, a lot of research has been conducted aimed at designing and implementing IMS capable clients and network elements. Though considerable work has been done in the development of IMS clients, there is no single, free and open source IMS client that provides researchers with all the required functionality needed to test the applications they are developing. For example, several open and closed source SIP/IMS clients are used within the Rhodes University Conver- gence Research Group (RUCRG) to test applications under development, as a result of the fact that the various SIP/IMS clients support different subsets of SIP/IMS features. The lack of a single client and the subsequent use of various clients comes with several problems. Researchers have to know how to deploy, configure, use and at times adapt the various clients to suit their needs. This can be very time consuming and, in fact, contradicts the IMS philosophy (the IMS was proposed to support rapid service creation). This thesis outlines the development of a Java-based, IMS compliant client called RUCRG IMS client, that uses the JAIN SIP Applet Phone (JSAP) as its foundation. JSAP, which originally offered only basic voice calling and instant messaging (IM) capabilities, was modified to be IMS compliant and support video calls, IM and presence using XML Configuration Access Protocol (XCAP).
- Full Text:
- Date Issued: 2015
- Authors: Muswera, Walter Tawanda
- Date: 2015
- Subjects: Internet Protocol multimedia subsystem , Java (Computer program language)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4712 , http://hdl.handle.net/10962/d1017934
- Description: Since the introduction of the IP Multimedia Subsystem (IMS) by the Third Generation Partnership Project (3GPP) in 2002, a lot of research has been conducted aimed at designing and implementing IMS capable clients and network elements. Though considerable work has been done in the development of IMS clients, there is no single, free and open source IMS client that provides researchers with all the required functionality needed to test the applications they are developing. For example, several open and closed source SIP/IMS clients are used within the Rhodes University Conver- gence Research Group (RUCRG) to test applications under development, as a result of the fact that the various SIP/IMS clients support different subsets of SIP/IMS features. The lack of a single client and the subsequent use of various clients comes with several problems. Researchers have to know how to deploy, configure, use and at times adapt the various clients to suit their needs. This can be very time consuming and, in fact, contradicts the IMS philosophy (the IMS was proposed to support rapid service creation). This thesis outlines the development of a Java-based, IMS compliant client called RUCRG IMS client, that uses the JAIN SIP Applet Phone (JSAP) as its foundation. JSAP, which originally offered only basic voice calling and instant messaging (IM) capabilities, was modified to be IMS compliant and support video calls, IM and presence using XML Configuration Access Protocol (XCAP).
- Full Text:
- Date Issued: 2015
Genetic and morphometric variation of Octopus vulgaris in the Benguela Current region
- Authors: De Beer, Chénelle Lesley
- Date: 2014
- Subjects: Common octopus -- Africa, Southern , Common octopus -- Genetics , Common octopus -- Morphology , Common octopus -- Geographical distribution , Variation (Biology) , Benguela Current
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5362 , http://hdl.handle.net/10962/d1012971
- Description: The Benguela Current is a cold eastern boundary current located on the south-western coast of the African continent. The establishment of its present day features approximately two million years ago has triggered allopatric events which have driven genetic and/or phenotypic differentiation in many of the warm-temperate organisms that previously had continuous distributions along the south and west coast of southern Africa. However, since many of these species have responded differently, despite similar isolation times, research in this region provides a unique opportunity to increase our understanding of evolutionary processes. The common octopus (Octopus vulgaris, Cuvier 1797) is a coastal, sedentary species, inhabiting coral reefs or rocky environments at depths of up to a 100m. It is considered to be one of the most extensively studied cephalopod species due to its worldwide distribution. However, very little research has been conducted on O. vulgaris in southern Africa. In order to gain a holistic understanding of the effects of the Benguela Current on population connectivity, genetic and phenotypic diversity, and evolutionary history of O. vulgaris, a comparative genetic and morphological study was conducted across the Benguela region. A total of 168 specimens of O. vulgaris were collected from four different regions across the Benguela system. A small tissue sample was preserved in ethanol for molecular analysis, and the specimen was frozen whole for morphometric analysis in the laboratory. Octopus vulgaris genetic population structure and evolutionary history was investigated using a 580bp fragment of the mitochondrial cytochrome b (cytb) gene for 76 individuals located within the Benguela region, yielding 10 different haplotypes. AMOVA and pairwise FST analyses revealed significant genetic differentiation suggesting a northern-southern Benguela divergence. Estimates of time since most recent common ancestor, based on biogeographical calibrators and coalescent analyses, indicated that isolation between the Angolan and South African population occurred between ~231 Ka and 1 Ma. Mismatch distribution analyses revealed a past population expansion within the South African O. vulgaris roughly 129.31 Ka, whilst Bayesian skyline plots were indicative of gradual demographic growth within the Angolan population in the last ~100 Ka. Observed O. vulgaris population structure and demographic history was likely the result of historical climate-induced change within the system. Reconstruction of phylogenetic relationships within the Octopus genus, using cytb and COI suggest that O. vulgaris is not a monophyletic group and a major systematic revision is required. Furthermore, unidentified individuals from South Africa were found to group with species from Indo-West Pacific Oceans and were therefore considered to have been translocated through ballast water from Asia. While the molecular analysis indicated a significant northern-southern Benguela structure results from the principle component analysis (PCA) and discriminate function analysis (DFA) were unable to distinguish between O. vulgaris from different sampling localities throughout the Benguela Current region based on soft-parts, hard-parts and meristic characters. The lack of phenotypic variation, despite significant genetic divergence, highlights the importance of multi-method approaches in gaining a holistic understanding of the taxonomy and biogeography of species.
- Full Text:
- Date Issued: 2014
- Authors: De Beer, Chénelle Lesley
- Date: 2014
- Subjects: Common octopus -- Africa, Southern , Common octopus -- Genetics , Common octopus -- Morphology , Common octopus -- Geographical distribution , Variation (Biology) , Benguela Current
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5362 , http://hdl.handle.net/10962/d1012971
- Description: The Benguela Current is a cold eastern boundary current located on the south-western coast of the African continent. The establishment of its present day features approximately two million years ago has triggered allopatric events which have driven genetic and/or phenotypic differentiation in many of the warm-temperate organisms that previously had continuous distributions along the south and west coast of southern Africa. However, since many of these species have responded differently, despite similar isolation times, research in this region provides a unique opportunity to increase our understanding of evolutionary processes. The common octopus (Octopus vulgaris, Cuvier 1797) is a coastal, sedentary species, inhabiting coral reefs or rocky environments at depths of up to a 100m. It is considered to be one of the most extensively studied cephalopod species due to its worldwide distribution. However, very little research has been conducted on O. vulgaris in southern Africa. In order to gain a holistic understanding of the effects of the Benguela Current on population connectivity, genetic and phenotypic diversity, and evolutionary history of O. vulgaris, a comparative genetic and morphological study was conducted across the Benguela region. A total of 168 specimens of O. vulgaris were collected from four different regions across the Benguela system. A small tissue sample was preserved in ethanol for molecular analysis, and the specimen was frozen whole for morphometric analysis in the laboratory. Octopus vulgaris genetic population structure and evolutionary history was investigated using a 580bp fragment of the mitochondrial cytochrome b (cytb) gene for 76 individuals located within the Benguela region, yielding 10 different haplotypes. AMOVA and pairwise FST analyses revealed significant genetic differentiation suggesting a northern-southern Benguela divergence. Estimates of time since most recent common ancestor, based on biogeographical calibrators and coalescent analyses, indicated that isolation between the Angolan and South African population occurred between ~231 Ka and 1 Ma. Mismatch distribution analyses revealed a past population expansion within the South African O. vulgaris roughly 129.31 Ka, whilst Bayesian skyline plots were indicative of gradual demographic growth within the Angolan population in the last ~100 Ka. Observed O. vulgaris population structure and demographic history was likely the result of historical climate-induced change within the system. Reconstruction of phylogenetic relationships within the Octopus genus, using cytb and COI suggest that O. vulgaris is not a monophyletic group and a major systematic revision is required. Furthermore, unidentified individuals from South Africa were found to group with species from Indo-West Pacific Oceans and were therefore considered to have been translocated through ballast water from Asia. While the molecular analysis indicated a significant northern-southern Benguela structure results from the principle component analysis (PCA) and discriminate function analysis (DFA) were unable to distinguish between O. vulgaris from different sampling localities throughout the Benguela Current region based on soft-parts, hard-parts and meristic characters. The lack of phenotypic variation, despite significant genetic divergence, highlights the importance of multi-method approaches in gaining a holistic understanding of the taxonomy and biogeography of species.
- Full Text:
- Date Issued: 2014
A qualitative exploration of the experience of Black women in violent relationships
- Authors: Mesatywa, Nontando Jennifer
- Date: 2011-11-16
- Subjects: Abused women -- South Africa , Abused wives -- South Africa , Family violence -- Research -- South Africa
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:701 , http://hdl.handle.net/10962/d1006458 , Abused women -- South Africa , Abused wives -- South Africa , Family violence -- Research -- South Africa
- Description: This study is a qualitative exploration of black women experiences in violent relationships. The study was conducted at Masimanyane Women Support Centre in East London. As a qualitative exploratory study, in-depth interviews were conducted and a sample of ten abused women was utilized. A study of related literature has been made to focus on the existing literature concerning abuse on black women. Various theories have been explored, various feminist views were discussed and the existing legal system, nationally and internationally was looked into. The findings suggest that black women are abused by their partners. Alcohol abuse, failing to support the children and extra marital relationships have been cited as some of the reasons. Women in abusive relationships in this study sustained physical as well as emotional abuse. The professional networks assisted these women to some extent. However, there is an indication of a dire need for training, interdisciplinary approach and a legal system that prohibits further abuse by male partners. Various recommendations have been postulated. The researcher indicated that there is a need for empowering programs for the abused, rehabilitative program for the abuser, and an effective legal system to prevent further abuse on women.
- Full Text:
- Authors: Mesatywa, Nontando Jennifer
- Date: 2011-11-16
- Subjects: Abused women -- South Africa , Abused wives -- South Africa , Family violence -- Research -- South Africa
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:701 , http://hdl.handle.net/10962/d1006458 , Abused women -- South Africa , Abused wives -- South Africa , Family violence -- Research -- South Africa
- Description: This study is a qualitative exploration of black women experiences in violent relationships. The study was conducted at Masimanyane Women Support Centre in East London. As a qualitative exploratory study, in-depth interviews were conducted and a sample of ten abused women was utilized. A study of related literature has been made to focus on the existing literature concerning abuse on black women. Various theories have been explored, various feminist views were discussed and the existing legal system, nationally and internationally was looked into. The findings suggest that black women are abused by their partners. Alcohol abuse, failing to support the children and extra marital relationships have been cited as some of the reasons. Women in abusive relationships in this study sustained physical as well as emotional abuse. The professional networks assisted these women to some extent. However, there is an indication of a dire need for training, interdisciplinary approach and a legal system that prohibits further abuse by male partners. Various recommendations have been postulated. The researcher indicated that there is a need for empowering programs for the abused, rehabilitative program for the abuser, and an effective legal system to prevent further abuse on women.
- Full Text:
Public sector industrial relations in the context of alliance politics: the case of Makana Local Municipality, South Africa (1994-2006)
- Authors: Makwembere, Sandra
- Date: 2007
- Subjects: Makana Municipality , South African Municipal Workers Union , African National Congress , Cosatu , South African Communist Party , Local government -- South Africa -- Eastern Cape , Industrial relations -- South Africa -- Eastern Cape , Labor unions -- South Africa , South Africa -- Politics and government -- 1994-
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:3301 , http://hdl.handle.net/10962/d1003089 , Makana Municipality , South African Municipal Workers Union , African National Congress , Cosatu , South African Communist Party , Local government -- South Africa -- Eastern Cape , Industrial relations -- South Africa -- Eastern Cape , Labor unions -- South Africa , South Africa -- Politics and government -- 1994-
- Description: This thesis is in the field of Industrial Relations. It concerns a micro-level investigation of the dynamics of public sector industrial relations in post-apartheid South Africa. It focuses on the Tripartite Alliance between the African National Congress (ANC), the South African Communist Party (SACP) and the Congress of South African Trade Unions (COSATU) and explores what the Alliance relationship has meant for the traditional roles of employees and their representatives on the one hand, and employers and their representatives on the other. The thesis examines the political, organisational and societal contradictions and implications for COSATU public sector union affiliates and their members in their relationship to the ANC as an ally (via the Alliance) and the context in which ANC members form part of management (in government). The South African Municipal Workers’ Union (SAMWU) was used as an archetype of a COSATU public sector union affiliate that engages with the State as employer at the municipal level. It is a case study of Makana Local Municipality (Eastern Cape Province, South Africa) using qualitative research techniques and content analysis to derive the relevant information. The author conducted a series of in-depth interviews of key informants and observations at Makana Local Municipality were done. Based on the empirical data obtained from the investigation, the thesis argues that the traditional roles in the employment relationship at the workplace have been affected by the political alliance. Industrial relations roles have become increasingly vague especially since many within local government share ANC/SACP memberships with members of the trade union. The study also highlights that within an increasingly globalising post-apartheid environment, the Alliance provides mixture of benefits and challenges for workplace negotiations and employment relations in ways that macro-level analyses of employer-employee relationships do not always capture.
- Full Text:
- Date Issued: 2007
- Authors: Makwembere, Sandra
- Date: 2007
- Subjects: Makana Municipality , South African Municipal Workers Union , African National Congress , Cosatu , South African Communist Party , Local government -- South Africa -- Eastern Cape , Industrial relations -- South Africa -- Eastern Cape , Labor unions -- South Africa , South Africa -- Politics and government -- 1994-
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:3301 , http://hdl.handle.net/10962/d1003089 , Makana Municipality , South African Municipal Workers Union , African National Congress , Cosatu , South African Communist Party , Local government -- South Africa -- Eastern Cape , Industrial relations -- South Africa -- Eastern Cape , Labor unions -- South Africa , South Africa -- Politics and government -- 1994-
- Description: This thesis is in the field of Industrial Relations. It concerns a micro-level investigation of the dynamics of public sector industrial relations in post-apartheid South Africa. It focuses on the Tripartite Alliance between the African National Congress (ANC), the South African Communist Party (SACP) and the Congress of South African Trade Unions (COSATU) and explores what the Alliance relationship has meant for the traditional roles of employees and their representatives on the one hand, and employers and their representatives on the other. The thesis examines the political, organisational and societal contradictions and implications for COSATU public sector union affiliates and their members in their relationship to the ANC as an ally (via the Alliance) and the context in which ANC members form part of management (in government). The South African Municipal Workers’ Union (SAMWU) was used as an archetype of a COSATU public sector union affiliate that engages with the State as employer at the municipal level. It is a case study of Makana Local Municipality (Eastern Cape Province, South Africa) using qualitative research techniques and content analysis to derive the relevant information. The author conducted a series of in-depth interviews of key informants and observations at Makana Local Municipality were done. Based on the empirical data obtained from the investigation, the thesis argues that the traditional roles in the employment relationship at the workplace have been affected by the political alliance. Industrial relations roles have become increasingly vague especially since many within local government share ANC/SACP memberships with members of the trade union. The study also highlights that within an increasingly globalising post-apartheid environment, the Alliance provides mixture of benefits and challenges for workplace negotiations and employment relations in ways that macro-level analyses of employer-employee relationships do not always capture.
- Full Text:
- Date Issued: 2007
The development of a geographic information system (GIS) as a mariculture sector planning tool in South Africa
- Authors: Shiran-Klotz, Imran
- Date: 2004
- Subjects: Geographic information systems -- South Africa , Fishery management -- Geographic information systems -- South Africa , Mariculture -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5337 , http://hdl.handle.net/10962/d1005870 , Geographic information systems -- South Africa , Fishery management -- Geographic information systems -- South Africa , Mariculture -- South Africa
- Description: The South African coastline has a high potential for mariculture development, particularly in land-based systems, due to excellent water quality, good infrastructure, and relatively cheap land in certain areas. Development of mariculture however, has been slow primarily due to the absence of a national sector development plan to coordinate contribution to development by government, industry and academia. Recent mariculture development plans however, supported by government commitment to stimulate coastal development, offers new opportunity for the sector's growth. These new sector development plans require a multi-disciplinary intensive information base with a strong regional and national spatial component. Geographic Information System (GIS) is a spatial analytical tool, which is capable of handling such large coastal databases and analysing them. Nevertheless, many mariculture GIS planning applications, often developed in isolation and with limited practical use for decision makers, highlighted the need to develop GIS in relation to the mariculture sector development plan. Hence, the aim of this study was to develop and evaluate a GIS for the national and regional mariculture sector planning process in South Africa, in order to identify potentially suitable areas along the South African coastline for mariculture operations. The GIS development in this study was based on the mariculture planning approach developed by PAP/RAe (1996), which recognizes the variations of scales in mariculture planning. Three case studies, representing the diversity of the South African sector plan, were selected to develop the GIS. They included: a national suitability analysis for all land-based culture systems, a specific national analysis on abalone ranching, and a detailed regional analysis of land-based culture and abalone ranching along the Namaqualand coastline. The GIS was developed separately for each case study based on a strategy consisting of six main phases, including: identification of project requirements, developing analytical framework, selection and location of data sources, organization and manipulation of data, analysing data and verifying and evaluation of the outputs. Biophysical, coastal use, and infrastructure criteria were collected, sorted and analysed to identify development constraints. Based on a set of conditions, and Boolean logic and arithmetic operations, unsuitable areas were identified and eliminated. Main constraints for national land-based development included competition over space along KwaZuluNatal Province coastline and restricted access to the coast along the south region of the Northern Cape Province, Wild Coast along the Eastern Cape Province, and Maputaland along KwaZulu-Natal Province. Ten areas along the country coastline were therefore identified as potentially suitable for land-based mariculture. Furthermore, South African abalone ranching potential was found to be limited mostly along the Western and Northern Cape Province's coastline due to the high risk of Paralytic Shellfish Poison (PSP) occurrences, alternative resource use and activities such as commercial fishery, poaching, and conservation. Hence, a total of nine areas along the Northern Cape, Western Cape, and Eastern Cape coastlines were identified as premier areas for abalone ranching. The regional study along the Namaqualand coastline revealed potential conflict between mining activity and mariculture development due to security issues and restricted access to the coast. Land-based mariculture development was confined to the four main coastal urban areas. The highest potential for land-based mariculture was along Port Nolloth and Kleinsee coastlines, whereas marine-based (i.e. abalone ranching) potential was poor along the north part of the coast due to intense marine mining activities, restricted access to the coast, and low kelp bed density. High potential abalone ranching areas were identified south to Kleinsee, and around Port Nolloth. Potential conflict with marine mining activity was minimal since it was localised and not related to kelp bed locations. It was concluded that GIS is a relevant and compatible tool for South African mariculture sector planning. However, future development of GIS as integrated planning tool in mariculture and coastal planning, requires updated spatial data (e.g. recreational activity), and continued interaction among project planners, mariculture specialists and GIS analysts.
- Full Text:
- Date Issued: 2004
- Authors: Shiran-Klotz, Imran
- Date: 2004
- Subjects: Geographic information systems -- South Africa , Fishery management -- Geographic information systems -- South Africa , Mariculture -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5337 , http://hdl.handle.net/10962/d1005870 , Geographic information systems -- South Africa , Fishery management -- Geographic information systems -- South Africa , Mariculture -- South Africa
- Description: The South African coastline has a high potential for mariculture development, particularly in land-based systems, due to excellent water quality, good infrastructure, and relatively cheap land in certain areas. Development of mariculture however, has been slow primarily due to the absence of a national sector development plan to coordinate contribution to development by government, industry and academia. Recent mariculture development plans however, supported by government commitment to stimulate coastal development, offers new opportunity for the sector's growth. These new sector development plans require a multi-disciplinary intensive information base with a strong regional and national spatial component. Geographic Information System (GIS) is a spatial analytical tool, which is capable of handling such large coastal databases and analysing them. Nevertheless, many mariculture GIS planning applications, often developed in isolation and with limited practical use for decision makers, highlighted the need to develop GIS in relation to the mariculture sector development plan. Hence, the aim of this study was to develop and evaluate a GIS for the national and regional mariculture sector planning process in South Africa, in order to identify potentially suitable areas along the South African coastline for mariculture operations. The GIS development in this study was based on the mariculture planning approach developed by PAP/RAe (1996), which recognizes the variations of scales in mariculture planning. Three case studies, representing the diversity of the South African sector plan, were selected to develop the GIS. They included: a national suitability analysis for all land-based culture systems, a specific national analysis on abalone ranching, and a detailed regional analysis of land-based culture and abalone ranching along the Namaqualand coastline. The GIS was developed separately for each case study based on a strategy consisting of six main phases, including: identification of project requirements, developing analytical framework, selection and location of data sources, organization and manipulation of data, analysing data and verifying and evaluation of the outputs. Biophysical, coastal use, and infrastructure criteria were collected, sorted and analysed to identify development constraints. Based on a set of conditions, and Boolean logic and arithmetic operations, unsuitable areas were identified and eliminated. Main constraints for national land-based development included competition over space along KwaZuluNatal Province coastline and restricted access to the coast along the south region of the Northern Cape Province, Wild Coast along the Eastern Cape Province, and Maputaland along KwaZulu-Natal Province. Ten areas along the country coastline were therefore identified as potentially suitable for land-based mariculture. Furthermore, South African abalone ranching potential was found to be limited mostly along the Western and Northern Cape Province's coastline due to the high risk of Paralytic Shellfish Poison (PSP) occurrences, alternative resource use and activities such as commercial fishery, poaching, and conservation. Hence, a total of nine areas along the Northern Cape, Western Cape, and Eastern Cape coastlines were identified as premier areas for abalone ranching. The regional study along the Namaqualand coastline revealed potential conflict between mining activity and mariculture development due to security issues and restricted access to the coast. Land-based mariculture development was confined to the four main coastal urban areas. The highest potential for land-based mariculture was along Port Nolloth and Kleinsee coastlines, whereas marine-based (i.e. abalone ranching) potential was poor along the north part of the coast due to intense marine mining activities, restricted access to the coast, and low kelp bed density. High potential abalone ranching areas were identified south to Kleinsee, and around Port Nolloth. Potential conflict with marine mining activity was minimal since it was localised and not related to kelp bed locations. It was concluded that GIS is a relevant and compatible tool for South African mariculture sector planning. However, future development of GIS as integrated planning tool in mariculture and coastal planning, requires updated spatial data (e.g. recreational activity), and continued interaction among project planners, mariculture specialists and GIS analysts.
- Full Text:
- Date Issued: 2004
Sulphate reduction utilizing hydrolysis of complex carbon sources
- Authors: Molipane, Ntaoleng Patricia
- Date: 1999
- Subjects: Sewage sludge , Acid mine drainage , Hydrolysis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4000 , http://hdl.handle.net/10962/d1004060 , Sewage sludge , Acid mine drainage , Hydrolysis
- Description: Due to environmental pollution caused by acid mine drainage (AMD), the Department of Water Affairs has developed a National Water Bill for managing and controlling the water environment to prevent AMD pollution. The application of sulphate reducing bacteria have been demonstrated for the treatment of AMD. However, the scale-up application of this technology ultimately depends on the cost and availability of a carbon source. This study evaluated the use of sewage sludge to provide a carbon source for sulphate reduction in synthetic drainage wastewaters. The demonstration of this process in a laboratory-scale reactor proved that sewage sludge could provide a useful model and viable carbon source for evaluation of sulphate reduction as a process for treating AMD. Since sewage sludge is a complex carbon source, hydrolysis reactions controlling the anaerobic digestion of particulate substrate from this medium were optimized by evaluating the effect of pH on hydrolysis. Controlled and uncontrolled pH studies were conducted using a three stage mixed anaerobic reactor. Analysis of the degradation behaviour of the three important organic classes (carbohydrate, proteins and lipids) revealed that each class followed an indvidual trend with respect to pH changes. In addition, the solubilization of organic particulate carbon was also shown to be a function of pH. The hydrolysis pattern of organic substrate and COD solublization was induced at pH 6.5 rather than at high pH values (7.5 and 8.5). The biodegradation activity of sewage sludge was characterized by the API-ZYM1N test system to provide rapid semiquantitative information on the activity of hydrolytic enzymes associated with the degradation of carbohydrates, lipids, proteins and nucleic acids. A wide range of enzyme activities with phosphatases, aminopeptidases, and glucosyl hydralases dominating were displayed. The pattern of substrate hydrolysis correlated to the degradation efficiency of each organic class as a function of pH. The evaluation of scale-up application for sulphate reduction utilizing sewage sludge as a carbon source demonstrated that large water volume flows could possibly be treated with this cost-effective technology. Generation of alkalinity and sulphide in this medium was shown to be successful in the removal of heavy metals by precipitation. The use of this technology coupled to reduced cost involved showed that biological sulphate reduction utilizing hydrolysates of complex organic particulate from sewage sludge ss a carbon source has a potential scale-up application for the treatment of AMD.
- Full Text:
- Date Issued: 1999
- Authors: Molipane, Ntaoleng Patricia
- Date: 1999
- Subjects: Sewage sludge , Acid mine drainage , Hydrolysis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4000 , http://hdl.handle.net/10962/d1004060 , Sewage sludge , Acid mine drainage , Hydrolysis
- Description: Due to environmental pollution caused by acid mine drainage (AMD), the Department of Water Affairs has developed a National Water Bill for managing and controlling the water environment to prevent AMD pollution. The application of sulphate reducing bacteria have been demonstrated for the treatment of AMD. However, the scale-up application of this technology ultimately depends on the cost and availability of a carbon source. This study evaluated the use of sewage sludge to provide a carbon source for sulphate reduction in synthetic drainage wastewaters. The demonstration of this process in a laboratory-scale reactor proved that sewage sludge could provide a useful model and viable carbon source for evaluation of sulphate reduction as a process for treating AMD. Since sewage sludge is a complex carbon source, hydrolysis reactions controlling the anaerobic digestion of particulate substrate from this medium were optimized by evaluating the effect of pH on hydrolysis. Controlled and uncontrolled pH studies were conducted using a three stage mixed anaerobic reactor. Analysis of the degradation behaviour of the three important organic classes (carbohydrate, proteins and lipids) revealed that each class followed an indvidual trend with respect to pH changes. In addition, the solubilization of organic particulate carbon was also shown to be a function of pH. The hydrolysis pattern of organic substrate and COD solublization was induced at pH 6.5 rather than at high pH values (7.5 and 8.5). The biodegradation activity of sewage sludge was characterized by the API-ZYM1N test system to provide rapid semiquantitative information on the activity of hydrolytic enzymes associated with the degradation of carbohydrates, lipids, proteins and nucleic acids. A wide range of enzyme activities with phosphatases, aminopeptidases, and glucosyl hydralases dominating were displayed. The pattern of substrate hydrolysis correlated to the degradation efficiency of each organic class as a function of pH. The evaluation of scale-up application for sulphate reduction utilizing sewage sludge as a carbon source demonstrated that large water volume flows could possibly be treated with this cost-effective technology. Generation of alkalinity and sulphide in this medium was shown to be successful in the removal of heavy metals by precipitation. The use of this technology coupled to reduced cost involved showed that biological sulphate reduction utilizing hydrolysates of complex organic particulate from sewage sludge ss a carbon source has a potential scale-up application for the treatment of AMD.
- Full Text:
- Date Issued: 1999
The use of remote sensing and Geographic Information System (GIS) techniques, to interpret savanna ecosystem patterns in the Sabi Sand Game Reserve, Mpumalanga province
- Fortescue, Alexander Kenneth John
- Authors: Fortescue, Alexander Kenneth John
- Date: 1997
- Subjects: Sabi-Sand Game Reserve (South Africa) , Savanna ecology -- South Africa -- Mpumalanga , Geographic information systems , Savanna ecology -- Remote sensing
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4857 , http://hdl.handle.net/10962/d1005533 , Sabi-Sand Game Reserve (South Africa) , Savanna ecology -- South Africa -- Mpumalanga , Geographic information systems , Savanna ecology -- Remote sensing
- Description: This thesis explores techniques which ultimately strive to optimize production systems in rangeland areas of southern Africa. By linking spatially significant, satellite derived data to practical measurements of vegetation structure, valuable insight has been derived on processes of ecosystem function, in the Sabi Sand Game Reserve. A broad ecosystem response mechanism has been established from a conventional Normalized Differentiation Vegetation Index (NDVI). By responding to increases in production, which are driven by disturbance, this index has allowed quantitative systems theory in savanna to be tested and refined. Methods of biomass and production estimation which are specifically designed to reduce the cost and time involved with the more conventional method of destructive harvesting have been tested in the savanna at the Sabi Sand Game Reserve. Results from these estimates relate well with data derived through destructive harvesting in structurally similar savanna. Moreover, by relating the above-ground woody production estimates to remere sensing indices, it was possible to demonstrate that the problem of extrapolation, universal to most biomass and production studies can be overcome. Since remote sensing encompasses an array of tools fundamental to rangeland inventory, monitoring and management, valuable spatially significant information pertaining to ecosystem structure and function has been provided for managers in the Sabi Sand Game Reserve.
- Full Text:
- Date Issued: 1997
- Authors: Fortescue, Alexander Kenneth John
- Date: 1997
- Subjects: Sabi-Sand Game Reserve (South Africa) , Savanna ecology -- South Africa -- Mpumalanga , Geographic information systems , Savanna ecology -- Remote sensing
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4857 , http://hdl.handle.net/10962/d1005533 , Sabi-Sand Game Reserve (South Africa) , Savanna ecology -- South Africa -- Mpumalanga , Geographic information systems , Savanna ecology -- Remote sensing
- Description: This thesis explores techniques which ultimately strive to optimize production systems in rangeland areas of southern Africa. By linking spatially significant, satellite derived data to practical measurements of vegetation structure, valuable insight has been derived on processes of ecosystem function, in the Sabi Sand Game Reserve. A broad ecosystem response mechanism has been established from a conventional Normalized Differentiation Vegetation Index (NDVI). By responding to increases in production, which are driven by disturbance, this index has allowed quantitative systems theory in savanna to be tested and refined. Methods of biomass and production estimation which are specifically designed to reduce the cost and time involved with the more conventional method of destructive harvesting have been tested in the savanna at the Sabi Sand Game Reserve. Results from these estimates relate well with data derived through destructive harvesting in structurally similar savanna. Moreover, by relating the above-ground woody production estimates to remere sensing indices, it was possible to demonstrate that the problem of extrapolation, universal to most biomass and production studies can be overcome. Since remote sensing encompasses an array of tools fundamental to rangeland inventory, monitoring and management, valuable spatially significant information pertaining to ecosystem structure and function has been provided for managers in the Sabi Sand Game Reserve.
- Full Text:
- Date Issued: 1997
An integrated approach to aspects of coastal dune planning and management along a portion of the Eastern Cape coastal zone
- Authors: Hellström, Gavin B
- Date: 1995
- Subjects: Coastal zone management -- South Africa , Sand dune ecology -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4197 , http://hdl.handle.net/10962/d1003766 , Coastal zone management -- South Africa , Sand dune ecology -- South Africa
- Description: Ecological evaluation techniques have been used to classify or evaluate the relative conservation worthiness of a portion of the Eastern Cape coastal zone from Cannon Rocks to Port Alfred. A system-based approach, using a basic GIS, was used to compare three aspects of the coastal zone. Two existing planning documents (EMATEK/s Coastal Vegetation Importance Rating plan and CPA's Cape Coastal Conservation plan) were statistically compared - based primarily on the size and number of the landscape fragments (environmental criteria polygons). The resultant plan, an Intermediate Sensitivity Class map, was further integrated with the biophysical aspect of the coastal zone - coastal dunes. The final map is the product of these overlays to be used as a-working overlay for coastal zone decision-making. This is an Environmental Sensitivity map, which has no particular direct reference to any particular biophysical criteria, which categorizes the coastal zone according to the environmental sensitivity or conservation worthiness of the site. The categories are listed according to a sliding-scale of sensitivity or worthiness. There is, however, it strong association between the final map and the vegetation status of the coastline, as a direct result of the vegetation rating map and indirectly from the perception based coastal conservation plan. The formation of most assessment or evaluation plans are based on the vegetation status of the area. This map can be overlayed over the particular stretch of the coastline which it covers and the particular conservation status noted. There are numerous techniques available for assessment and evaluation each having their own specific merits and advantages. This plan, however, is a first attempt at integrating other specific plans into a single working document for the coastal zone manager.
- Full Text:
- Date Issued: 1995
- Authors: Hellström, Gavin B
- Date: 1995
- Subjects: Coastal zone management -- South Africa , Sand dune ecology -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4197 , http://hdl.handle.net/10962/d1003766 , Coastal zone management -- South Africa , Sand dune ecology -- South Africa
- Description: Ecological evaluation techniques have been used to classify or evaluate the relative conservation worthiness of a portion of the Eastern Cape coastal zone from Cannon Rocks to Port Alfred. A system-based approach, using a basic GIS, was used to compare three aspects of the coastal zone. Two existing planning documents (EMATEK/s Coastal Vegetation Importance Rating plan and CPA's Cape Coastal Conservation plan) were statistically compared - based primarily on the size and number of the landscape fragments (environmental criteria polygons). The resultant plan, an Intermediate Sensitivity Class map, was further integrated with the biophysical aspect of the coastal zone - coastal dunes. The final map is the product of these overlays to be used as a-working overlay for coastal zone decision-making. This is an Environmental Sensitivity map, which has no particular direct reference to any particular biophysical criteria, which categorizes the coastal zone according to the environmental sensitivity or conservation worthiness of the site. The categories are listed according to a sliding-scale of sensitivity or worthiness. There is, however, it strong association between the final map and the vegetation status of the coastline, as a direct result of the vegetation rating map and indirectly from the perception based coastal conservation plan. The formation of most assessment or evaluation plans are based on the vegetation status of the area. This map can be overlayed over the particular stretch of the coastline which it covers and the particular conservation status noted. There are numerous techniques available for assessment and evaluation each having their own specific merits and advantages. This plan, however, is a first attempt at integrating other specific plans into a single working document for the coastal zone manager.
- Full Text:
- Date Issued: 1995
Towards a gender analysis of women and development: a case study of the gender division of labour in a rural black community in South Africa
- Authors: Middleton, Susan Clare
- Date: 1994
- Subjects: Rural women -- Employment -- South Africa -- Case studies , Women in development -- South Africa -- Case studies , Sexual division of labor -- South Africa , Sex role -- South Africa -- Case studies , Sexual division of labor -- South Africa -- Eastern Cape -- Thornhill -- Merino Walk
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:3326 , http://hdl.handle.net/10962/d1003114 , Rural women -- Employment -- South Africa -- Case studies , Women in development -- South Africa -- Case studies , Sexual division of labor -- South Africa , Sex role -- South Africa -- Case studies , Sexual division of labor -- South Africa -- Eastern Cape -- Thornhill -- Merino Walk
- Description: This thesis examines the topic of the position of women in rural development. This topic has become the focus of extensive international debate at theoretical and policy levels, but for historical reasons remains relatively undeveloped in South Africa. After reviewing a number of contemporary approaches, the thesis argues in favour of the "Gender and Development" approach, and applies this to a case study of the gender division of labour in a rural black community in South Africa. Chapter one reviews the variants of the "Women in Development" (WID) approaches, as well as the claims of "Global Feminism". It is argued that, although Global Feminism began as a critique of WID approaches, it is in fact similar in many respects to the contemporary "empowerment" focus within the WID tradition. Although useful, these approaches are not sufficiently explicit in their theorizing of gender relations in the context of development. Chapter 2 sets out the key elements of the "Gender and Development" approach, which emphasises the complexity of the issue of women's interests, and warns against assuming a commonality of interests amongst all women. Instead, the GAD approach demands a detailed investigation of socially constructed gender relations in specific communities, with a special focus on the gender division of labour. For GAD theorists such analysis is a requirement of development planning which seeks to advance the position of women. Chapter 3 spells out the methodological implications of the GAD approach, and develops a specific research design, influenced by GAD as well as feminist methodology, for the investigation of the gender-specific needs of women in Merino Walk, a rural black community. Chapter 4 presents a brief overview of the general context of rural women in Southern Africa, and a specific history of the Merino Walk community. Chapter 5 presents the results of the research. In the context of this thesis, the results are presented essentially as an illustration of the application of the GAD principles to a specific South African example. The conclusion draws out some of the issues which emerge from the research.
- Full Text:
- Date Issued: 1994
- Authors: Middleton, Susan Clare
- Date: 1994
- Subjects: Rural women -- Employment -- South Africa -- Case studies , Women in development -- South Africa -- Case studies , Sexual division of labor -- South Africa , Sex role -- South Africa -- Case studies , Sexual division of labor -- South Africa -- Eastern Cape -- Thornhill -- Merino Walk
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:3326 , http://hdl.handle.net/10962/d1003114 , Rural women -- Employment -- South Africa -- Case studies , Women in development -- South Africa -- Case studies , Sexual division of labor -- South Africa , Sex role -- South Africa -- Case studies , Sexual division of labor -- South Africa -- Eastern Cape -- Thornhill -- Merino Walk
- Description: This thesis examines the topic of the position of women in rural development. This topic has become the focus of extensive international debate at theoretical and policy levels, but for historical reasons remains relatively undeveloped in South Africa. After reviewing a number of contemporary approaches, the thesis argues in favour of the "Gender and Development" approach, and applies this to a case study of the gender division of labour in a rural black community in South Africa. Chapter one reviews the variants of the "Women in Development" (WID) approaches, as well as the claims of "Global Feminism". It is argued that, although Global Feminism began as a critique of WID approaches, it is in fact similar in many respects to the contemporary "empowerment" focus within the WID tradition. Although useful, these approaches are not sufficiently explicit in their theorizing of gender relations in the context of development. Chapter 2 sets out the key elements of the "Gender and Development" approach, which emphasises the complexity of the issue of women's interests, and warns against assuming a commonality of interests amongst all women. Instead, the GAD approach demands a detailed investigation of socially constructed gender relations in specific communities, with a special focus on the gender division of labour. For GAD theorists such analysis is a requirement of development planning which seeks to advance the position of women. Chapter 3 spells out the methodological implications of the GAD approach, and develops a specific research design, influenced by GAD as well as feminist methodology, for the investigation of the gender-specific needs of women in Merino Walk, a rural black community. Chapter 4 presents a brief overview of the general context of rural women in Southern Africa, and a specific history of the Merino Walk community. Chapter 5 presents the results of the research. In the context of this thesis, the results are presented essentially as an illustration of the application of the GAD principles to a specific South African example. The conclusion draws out some of the issues which emerge from the research.
- Full Text:
- Date Issued: 1994
A preliminary appraisal of the mineral potential of Venda based on a reconnaissance geochemical soil sampling survey and literature review
- Wilson, Michael George Carey
- Authors: Wilson, Michael George Carey
- Date: 1990
- Subjects: Mines and mineral resources -- South Africa -- Venda
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4994 , http://hdl.handle.net/10962/d1005606 , Mines and mineral resources -- South Africa -- Venda
- Description: A reconnaissance soil sampling survey was carried out over Venda by Cycad (Pty) Ltd and the samples were analysed for 36 elements using XRF techniques, by Anglo American Research Laboratories in Johanuesburg. The data resulting from this survey forms the basis for the present interpretive study. Initially the sample positions were co-ordinated, then the geological, soil and sample types were allocated to each point. Twelve lithological groupings were chosen which incorporated most of the available data, retained significant geological characteristics and consisted of statistically significant sample populations. Statistical manipulation was undertaken for each of the lithological groups. Using a final population of 5768 samples, means were determined and anomalous values were identified using a threshold of mean plus two standard deviations. Due to time and budgetary constraints, 24 of the 36 elements were chosen for statisical manipulation and fourteen of these, with particular economic significance, were chosen for plotting, wherever significant numbers of anomalies were present. The element overlays were plotted so as to coincide with 18 of the 25, 1:50 000 topographic sheets covering Venda , the remaining 7 having inadequate sample coverage to yield meaningful contours. In this way a total of 175 element overlay sheets were plotted, each showing contoured element levels, with selected anomalous values. The treatment of the vast body of information made available by the Cycad sampling programme has thus been selective and has continually been aimed at highlighting and concentrating attention on the areas of greatest indicated mineralization potential, rather than on specific anomalies. In this regard it is felt that the present study has been successful, in spite of limited sample coverage in some areas. Combining the results of this study with a modern tectonically-based appraisal of mineralization potential and a knowledge of the local geology and previously known mineralization gleaned from an extensive literature review, the following types of mineralization are considered to have the highest potential in Venda: i) Nickel-copper-platinum mineralization as well as magnesite, in the olivine dolerite sills which intrude the base of the Karoo Sequence in Northern Venda. ii) Coal in the basal Karoo Sequence sediments in a broad zone from Jazz 715 MS in the west, and along the Klein Tshipise fault from Amonda 159 MT to the Mutale Copper Fields then east of these to the Kruger National Park. Where intrusives invade these lower Karoo sed iments the potential exists for amorphous graphite. iii) Hydrothermal copper and possibly gold and silver concentrations, in Nzhelele and Sibasa Formation rocks, particularly those associated with faults known to have been active in post-Soutpansberg times. iv) Sediment-hosted massive sulphide deposits (Cu-Pb -Zn) close to basin margin faults, near intersections with cross cutting faults that have resulted in localized basin formation. These are most likely in the Soutpansberg sediments. v) Martle, flake-graphite and late stage skarn mineralization (including lead, zinc, gold and tungsten), in calcareous rocks of the Gumbu Formation.
- Full Text:
- Date Issued: 1990
- Authors: Wilson, Michael George Carey
- Date: 1990
- Subjects: Mines and mineral resources -- South Africa -- Venda
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4994 , http://hdl.handle.net/10962/d1005606 , Mines and mineral resources -- South Africa -- Venda
- Description: A reconnaissance soil sampling survey was carried out over Venda by Cycad (Pty) Ltd and the samples were analysed for 36 elements using XRF techniques, by Anglo American Research Laboratories in Johanuesburg. The data resulting from this survey forms the basis for the present interpretive study. Initially the sample positions were co-ordinated, then the geological, soil and sample types were allocated to each point. Twelve lithological groupings were chosen which incorporated most of the available data, retained significant geological characteristics and consisted of statistically significant sample populations. Statistical manipulation was undertaken for each of the lithological groups. Using a final population of 5768 samples, means were determined and anomalous values were identified using a threshold of mean plus two standard deviations. Due to time and budgetary constraints, 24 of the 36 elements were chosen for statisical manipulation and fourteen of these, with particular economic significance, were chosen for plotting, wherever significant numbers of anomalies were present. The element overlays were plotted so as to coincide with 18 of the 25, 1:50 000 topographic sheets covering Venda , the remaining 7 having inadequate sample coverage to yield meaningful contours. In this way a total of 175 element overlay sheets were plotted, each showing contoured element levels, with selected anomalous values. The treatment of the vast body of information made available by the Cycad sampling programme has thus been selective and has continually been aimed at highlighting and concentrating attention on the areas of greatest indicated mineralization potential, rather than on specific anomalies. In this regard it is felt that the present study has been successful, in spite of limited sample coverage in some areas. Combining the results of this study with a modern tectonically-based appraisal of mineralization potential and a knowledge of the local geology and previously known mineralization gleaned from an extensive literature review, the following types of mineralization are considered to have the highest potential in Venda: i) Nickel-copper-platinum mineralization as well as magnesite, in the olivine dolerite sills which intrude the base of the Karoo Sequence in Northern Venda. ii) Coal in the basal Karoo Sequence sediments in a broad zone from Jazz 715 MS in the west, and along the Klein Tshipise fault from Amonda 159 MT to the Mutale Copper Fields then east of these to the Kruger National Park. Where intrusives invade these lower Karoo sed iments the potential exists for amorphous graphite. iii) Hydrothermal copper and possibly gold and silver concentrations, in Nzhelele and Sibasa Formation rocks, particularly those associated with faults known to have been active in post-Soutpansberg times. iv) Sediment-hosted massive sulphide deposits (Cu-Pb -Zn) close to basin margin faults, near intersections with cross cutting faults that have resulted in localized basin formation. These are most likely in the Soutpansberg sediments. v) Martle, flake-graphite and late stage skarn mineralization (including lead, zinc, gold and tungsten), in calcareous rocks of the Gumbu Formation.
- Full Text:
- Date Issued: 1990
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