Thermoluminescence of annealed synthetic quartz
- Atang, Elizabeth Fende Midiki
- Authors: Atang, Elizabeth Fende Midiki
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/420 , vital:19957
- Description: The kinetic and dosimetric features of the main thermoluminescent peak of synthetic quartz have been investigated in quartz ordinarily annealed at 500_C as well as quartz annealed at 500_C for 10 minutes. The main peak is found at 78 _C for the samples annealed at 500_C for 10 minutes irradiated to 10 Gy and heated at 1.0 _C/s. For the samples ordinarily annealed at 500_C the main peak is found at 106 _C after the sample has been irradiated to 30 Gy and heated at 5.0 _C/s. In these samples, the intensity of the main peak is enhanced with repetitive measurement whereas its maximum temperature is unaffected. The peak position of the main peak in the sample is independent of the irradiation dose and this, together with its fading characteristics, are consistent with first-order kinetics. For doses between 5 and 25 Gy, the dose response of the main peak of the annealed sample is superlinear. The half-life of the main TL peak of the annealed sample is about 1 h. The activation energy E of the main peak is around 0.90 eV. For a heating rate of 0.4 _C/s, its order of kinetics b derived from the whole curve method of analysis is 1.0. Following irradiation, preheating and illumination with 470 nm blue light, the main peak in the annealed sample is regenerated during heating. The resulting phototransferred peak occurs at the same temperature as the original peak and has similar kinetic and dosimetric features, with a half-life of about 1 h. For a preheat temperature of 200 _C, the intensity of the phototransferred peak in the sample increases with illumination time up to a maximum and decreases thereafter. At longer illumination times, no further decrease in the intensity of the phototransferred peak is observed. The traps associated with the 325 _C peak are the main source of the electrons responsible for the regenerated peak.
- Full Text:
- Date Issued: 2016
- Authors: Atang, Elizabeth Fende Midiki
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/420 , vital:19957
- Description: The kinetic and dosimetric features of the main thermoluminescent peak of synthetic quartz have been investigated in quartz ordinarily annealed at 500_C as well as quartz annealed at 500_C for 10 minutes. The main peak is found at 78 _C for the samples annealed at 500_C for 10 minutes irradiated to 10 Gy and heated at 1.0 _C/s. For the samples ordinarily annealed at 500_C the main peak is found at 106 _C after the sample has been irradiated to 30 Gy and heated at 5.0 _C/s. In these samples, the intensity of the main peak is enhanced with repetitive measurement whereas its maximum temperature is unaffected. The peak position of the main peak in the sample is independent of the irradiation dose and this, together with its fading characteristics, are consistent with first-order kinetics. For doses between 5 and 25 Gy, the dose response of the main peak of the annealed sample is superlinear. The half-life of the main TL peak of the annealed sample is about 1 h. The activation energy E of the main peak is around 0.90 eV. For a heating rate of 0.4 _C/s, its order of kinetics b derived from the whole curve method of analysis is 1.0. Following irradiation, preheating and illumination with 470 nm blue light, the main peak in the annealed sample is regenerated during heating. The resulting phototransferred peak occurs at the same temperature as the original peak and has similar kinetic and dosimetric features, with a half-life of about 1 h. For a preheat temperature of 200 _C, the intensity of the phototransferred peak in the sample increases with illumination time up to a maximum and decreases thereafter. At longer illumination times, no further decrease in the intensity of the phototransferred peak is observed. The traps associated with the 325 _C peak are the main source of the electrons responsible for the regenerated peak.
- Full Text:
- Date Issued: 2016
Thermoluminescence of kunzite: a study of kinetic processes and dosimetry characteristics
- Ogundare, F O, Alatishe, M A, Chithambo, Makaiko L, Costin, G
- Authors: Ogundare, F O , Alatishe, M A , Chithambo, Makaiko L , Costin, G
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124701 , vital:35650 , https://doi.org/10.1016/j.nimb.2016.02.059
- Description: Since the use of natural minerals for dating and dose reconstruction using luminescence techniques is well-established and always of interest, we present thermoluminescence characteristics of kunzite, a gem variety of spodumene. The chemical composition of the sample was determined using an Electron Probe MicroAnalyzer.
- Full Text: false
- Date Issued: 2016
- Authors: Ogundare, F O , Alatishe, M A , Chithambo, Makaiko L , Costin, G
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124701 , vital:35650 , https://doi.org/10.1016/j.nimb.2016.02.059
- Description: Since the use of natural minerals for dating and dose reconstruction using luminescence techniques is well-established and always of interest, we present thermoluminescence characteristics of kunzite, a gem variety of spodumene. The chemical composition of the sample was determined using an Electron Probe MicroAnalyzer.
- Full Text: false
- Date Issued: 2016
The design of a centre for water sports in Newlands, Cape Town
- Authors: MacKenzie, Paul
- Date: 2016
- Subjects: Sports facilities -- South Africa -- Cape Town -- Designs and plans Recreation centers -- South Africa -- Cape Town -- Designs and plans
- Language: English
- Type: Thesis , Masters , MArch
- Identifier: http://hdl.handle.net/10948/39218 , vital:35064
- Description: This treatise focuses on the design of a Water Sports Centre in the sporting precinct of Newlands in Cape Town. The building is concerned with the redevelopment of an existing facility that is underutilised and outdated, compared to the 21st-century sporting arena. The purpose of this treatise is to investigate the processes and issues involved in the design of a Water Sports Centre that is located in a public park environment, and to better understand the contextual, spatial, physical, and theoretical influences on the nature of such a project’s architectural resolution. The process begins with an analysis of the two separate typologies, namely, water sports centres and sports stadiums, to better understand the spatial and physical nature of the combined building types. Various precedents are investigated of which the materiality and physical nature of the buildings are uncovered to identify an appropriate architectural language. Moreover, the spatial nature of these buildings are divided into categories of which the inter-relationships are analysed. The nature of the site is then investigated to identify and develop constraints and design informants. The site-defining elements are analysed individually, and a corresponding set of issues is established through the study of particular precedents. With an understanding of the physical and spatial attributes of the typology, combined with an appropriate response to the site, the design resolution for the Water Sports Centre in the Newlands sporting precinct is presented.
- Full Text:
- Date Issued: 2016
- Authors: MacKenzie, Paul
- Date: 2016
- Subjects: Sports facilities -- South Africa -- Cape Town -- Designs and plans Recreation centers -- South Africa -- Cape Town -- Designs and plans
- Language: English
- Type: Thesis , Masters , MArch
- Identifier: http://hdl.handle.net/10948/39218 , vital:35064
- Description: This treatise focuses on the design of a Water Sports Centre in the sporting precinct of Newlands in Cape Town. The building is concerned with the redevelopment of an existing facility that is underutilised and outdated, compared to the 21st-century sporting arena. The purpose of this treatise is to investigate the processes and issues involved in the design of a Water Sports Centre that is located in a public park environment, and to better understand the contextual, spatial, physical, and theoretical influences on the nature of such a project’s architectural resolution. The process begins with an analysis of the two separate typologies, namely, water sports centres and sports stadiums, to better understand the spatial and physical nature of the combined building types. Various precedents are investigated of which the materiality and physical nature of the buildings are uncovered to identify an appropriate architectural language. Moreover, the spatial nature of these buildings are divided into categories of which the inter-relationships are analysed. The nature of the site is then investigated to identify and develop constraints and design informants. The site-defining elements are analysed individually, and a corresponding set of issues is established through the study of particular precedents. With an understanding of the physical and spatial attributes of the typology, combined with an appropriate response to the site, the design resolution for the Water Sports Centre in the Newlands sporting precinct is presented.
- Full Text:
- Date Issued: 2016
The design of a cultural resource centre in the lower Khuiseb river valley, Namibia: a collective project
- Authors: Niedermeier, Inka
- Date: 2016
- Subjects: Community centers -- Namibia -- Designs and plans Community centers -- Namibia
- Language: English
- Type: Thesis , Masters , MArch
- Identifier: http://hdl.handle.net/10948/38830 , vital:35004
- Description: The treatise focuses on how to design built space that is ‘place-specific’ and captures the ‘spirit’ of the Namib Desert landscape through the experience of architecture. The project specifically focuses on tourism developments in natural and cultural environments. An investigation and analysis are done of the nature of the physical, spatial and cultural context of the ephemeral Khuiseb river of Namibia. By inductive and deductive reasoning, an argument is presented regarding the appropriate architectural approach of a luxury eco-lodge in a proposed eco-tourism precinct, that captures the Zeitgeist of the context while responding to the socio-economic conditions to encourage an autonomous community in a selfsufficient and sustainable way.
- Full Text:
- Date Issued: 2016
- Authors: Niedermeier, Inka
- Date: 2016
- Subjects: Community centers -- Namibia -- Designs and plans Community centers -- Namibia
- Language: English
- Type: Thesis , Masters , MArch
- Identifier: http://hdl.handle.net/10948/38830 , vital:35004
- Description: The treatise focuses on how to design built space that is ‘place-specific’ and captures the ‘spirit’ of the Namib Desert landscape through the experience of architecture. The project specifically focuses on tourism developments in natural and cultural environments. An investigation and analysis are done of the nature of the physical, spatial and cultural context of the ephemeral Khuiseb river of Namibia. By inductive and deductive reasoning, an argument is presented regarding the appropriate architectural approach of a luxury eco-lodge in a proposed eco-tourism precinct, that captures the Zeitgeist of the context while responding to the socio-economic conditions to encourage an autonomous community in a selfsufficient and sustainable way.
- Full Text:
- Date Issued: 2016
The design of a digital resource centre in Motherwell, Port Elizabeth
- Authors: Bursey, Rowan
- Date: 2016
- Subjects: Community centers -- South Africa -- Port Elizabeth -- Designs and plans Community centers -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MArch
- Identifier: http://hdl.handle.net/10948/38874 , vital:35009
- Description: This treatise is centered on the design of a digital resource centre in the township of Motherwell, Port Elizabeth. The building is concerned with providing a civic space which promotes access to and effective use of digital information and communication technologies. The treatise explores the issues and methods involved in the design of a public digital resource centre. The research starts with an investigation into the nature of public space and civic facilities within a South African township context before exploring the development of the library typology and its evolution in the digital age, while exploring the issues and processes involved in the design of a civic building in a township environment. The architectural design is seen as an appropriate response to the identified architectural issues. Relevant precedents are chosen based on the nature of these issues and the context in which they are situated. The buildings are analyzed in terms of these key issues and will thereby provide an understanding of the architectural identity of the civic building archetype. An understanding of the architectural typology and an analysis of relevant precedents leads to the identification of a set of site selection criteria which can be used to select an appropriate site within the Motherwell precinct. The nature of Motherwell and the identified issues related to the selected site are then investigated in order to develop a set of informants and constraints. Specific elements which are unique to the selected site are then investigated individually while using relevant precedents to establish an appropriate response to the issues involved. An appropriate architectural response is then developed through an understanding of the physical and spatial qualities of the building typology while also responding to the specific issues related to the site.
- Full Text:
- Date Issued: 2016
- Authors: Bursey, Rowan
- Date: 2016
- Subjects: Community centers -- South Africa -- Port Elizabeth -- Designs and plans Community centers -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MArch
- Identifier: http://hdl.handle.net/10948/38874 , vital:35009
- Description: This treatise is centered on the design of a digital resource centre in the township of Motherwell, Port Elizabeth. The building is concerned with providing a civic space which promotes access to and effective use of digital information and communication technologies. The treatise explores the issues and methods involved in the design of a public digital resource centre. The research starts with an investigation into the nature of public space and civic facilities within a South African township context before exploring the development of the library typology and its evolution in the digital age, while exploring the issues and processes involved in the design of a civic building in a township environment. The architectural design is seen as an appropriate response to the identified architectural issues. Relevant precedents are chosen based on the nature of these issues and the context in which they are situated. The buildings are analyzed in terms of these key issues and will thereby provide an understanding of the architectural identity of the civic building archetype. An understanding of the architectural typology and an analysis of relevant precedents leads to the identification of a set of site selection criteria which can be used to select an appropriate site within the Motherwell precinct. The nature of Motherwell and the identified issues related to the selected site are then investigated in order to develop a set of informants and constraints. Specific elements which are unique to the selected site are then investigated individually while using relevant precedents to establish an appropriate response to the issues involved. An appropriate architectural response is then developed through an understanding of the physical and spatial qualities of the building typology while also responding to the specific issues related to the site.
- Full Text:
- Date Issued: 2016
The design of a new medical faculty building at Livingston Hospital in Port Elizabeth
- Authors: Erwee, Chantal
- Date: 2016
- Subjects: College buildings -- South Africa -- Port Elizabeth -- Designs and plans College buildings -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MArch
- Identifier: http://hdl.handle.net/10948/39076 , vital:35036
- Description: On 24 July 2016, the Nelson Mandela Metropolitan University (NMMU) announced formal state approval to establish a new medical school. This treatise proposes the design of the medical faculty for NMMU. This medical faculty will challenge the typical school typology by the application of Biophilic design principles. This is achieved by critically engaging with the nature of a medical faculty and campus and by examining the context in which the proposal takes place. By means of a typological investigation, Livingstone Hospital in Port Elizabeth was deemed the most suitable location for the medical faculty. Through the integration of the programmatic requirements, technical strategy and the model of Biophilia, which stimulates the physiological needs and neurological functions of the users, the treatise successfully established a new precedent for medical school design in South Africa. The investigation of Livingstone Hospital highlighted the need for rehabilitation of the adjacent green structures and the campus as a whole. The design provides the “stent” which will fuse these entities, healing not only the physical campus but the users of the campus, the surrounding landscape and ultimately the adjacent precinct. The introduction of a medical faculty to the Health Sciences Department of NMMU in Port Elizabeth will breathe new life into the medical industry, unclogging the arteries which restrict the provision of healthcare for South African citizens.
- Full Text:
- Date Issued: 2016
- Authors: Erwee, Chantal
- Date: 2016
- Subjects: College buildings -- South Africa -- Port Elizabeth -- Designs and plans College buildings -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MArch
- Identifier: http://hdl.handle.net/10948/39076 , vital:35036
- Description: On 24 July 2016, the Nelson Mandela Metropolitan University (NMMU) announced formal state approval to establish a new medical school. This treatise proposes the design of the medical faculty for NMMU. This medical faculty will challenge the typical school typology by the application of Biophilic design principles. This is achieved by critically engaging with the nature of a medical faculty and campus and by examining the context in which the proposal takes place. By means of a typological investigation, Livingstone Hospital in Port Elizabeth was deemed the most suitable location for the medical faculty. Through the integration of the programmatic requirements, technical strategy and the model of Biophilia, which stimulates the physiological needs and neurological functions of the users, the treatise successfully established a new precedent for medical school design in South Africa. The investigation of Livingstone Hospital highlighted the need for rehabilitation of the adjacent green structures and the campus as a whole. The design provides the “stent” which will fuse these entities, healing not only the physical campus but the users of the campus, the surrounding landscape and ultimately the adjacent precinct. The introduction of a medical faculty to the Health Sciences Department of NMMU in Port Elizabeth will breathe new life into the medical industry, unclogging the arteries which restrict the provision of healthcare for South African citizens.
- Full Text:
- Date Issued: 2016
The design of a primary healthcare centre for women and children in KwaZakhele, Port Elizabeth
- Authors: Du Preez, Ashleigh
- Date: 2016
- Subjects: Health facilities -- Designs and plans Health facilities -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MArch
- Identifier: http://hdl.handle.net/10948/38863 , vital:35008
- Description: This treatise focuses on the design of a primary health care centre for women and children in Kwazakhele, Port Elizabeth. The primary health care facility will provide the space ‘in-between’ home and hospital and will promote improved maternal care by concentrating on antenatal and postnatal services, delivered in a safe environment. The Centre will encompass an understanding of cultural, social and economic informants of health and enable an empowerment of community through a holistic approach to health care design. The Centre aims at dealing with both physical and mental issues that are connected to pregnancy, as well as other aspects of women’s health needs. A maternity ward, as well as a psychological component that deals with antenatal depression and rape counselling, will be incorporated into the design. Understanding traditions in township architecture and the design of healthcare centres internationally and in South Africa provide the basis of a cultural engagement stimulating the design of a health centre providing opportunities for social interaction.By enhancing the urban space, a better quality of living will be provided in the community. Through this intervention, the promotion of wellness will be stimulated and strengthened.
- Full Text:
- Date Issued: 2016
- Authors: Du Preez, Ashleigh
- Date: 2016
- Subjects: Health facilities -- Designs and plans Health facilities -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MArch
- Identifier: http://hdl.handle.net/10948/38863 , vital:35008
- Description: This treatise focuses on the design of a primary health care centre for women and children in Kwazakhele, Port Elizabeth. The primary health care facility will provide the space ‘in-between’ home and hospital and will promote improved maternal care by concentrating on antenatal and postnatal services, delivered in a safe environment. The Centre will encompass an understanding of cultural, social and economic informants of health and enable an empowerment of community through a holistic approach to health care design. The Centre aims at dealing with both physical and mental issues that are connected to pregnancy, as well as other aspects of women’s health needs. A maternity ward, as well as a psychological component that deals with antenatal depression and rape counselling, will be incorporated into the design. Understanding traditions in township architecture and the design of healthcare centres internationally and in South Africa provide the basis of a cultural engagement stimulating the design of a health centre providing opportunities for social interaction.By enhancing the urban space, a better quality of living will be provided in the community. Through this intervention, the promotion of wellness will be stimulated and strengthened.
- Full Text:
- Date Issued: 2016
The design of botanical conservatory facilities at cathedral peak in the Drakensberg, KwaZulu Natal: a cathedral of conservation
- Authors: Hirst, Charné
- Date: 2016
- Subjects: Conservatories -- South Africa -- KwaZulu-Natal -- Design and plans Architecture -- Environmental aspects , Architecture, Modern -- 20th century
- Language: English
- Type: Thesis , Masters , MArch
- Identifier: http://hdl.handle.net/10948/39098 , vital:35042
- Description: This treatise investigates how eco-tourism can be employed to support the development of natural identity and place-making of a sacred environment through architectural intervention in the midst of an industrialised society. The principle argument of this treatise is that through the symbiosis of nature and the built environment, architecture can provide a counter-narrative to the disconnection between humans and nature. With ecotourism being a contemporary attempt to re-connect humans with our natural routes, to create awareness, a spiritual awakening and a global warming crisis intervention, this treatise will be the architectural product of conservation. The unification of ecology and architecture is critical to a contemporary definition of the natural environment. This treatise proposes the design of botanical conservatory facilities at Cathedral Peak, a tourist and research precinct in the renowned natural and cultural National Heritage Site of the Drakensberg Mountains. It presents an architecture which becomes an extension of the landscape and articulates its natural ecological systems through architectural design, while reinforcing the junction of the natural and built environment. It places the focus on integration between inside/outside spaces, in which the harmonious and symbiotic relationship can be experienced. Although it presents a contemporary architecture, it integrates various vernacular material and tectonic references, becoming a symbol of the nature of the place. The proposal is further described as a ‘cathedral of conservation’ designed as a modulated system for the simulation of particular climatic environments, with attributes drawn from the Gothic cathedral archetype in its attention to verticality and detail to materiality, and from a phenomenological perspective of place and identity as a building asserting the distinctive nature of the place. This cathedral of conservation is an architectural response to the sacredness and spirituality of the mountains, inducing a dialogue between the conservatory and the mighty Cathedral Peak which is one of the most famous natural attributes of the Drakensberg and thus the site’s most valuable vista.
- Full Text:
- Date Issued: 2016
- Authors: Hirst, Charné
- Date: 2016
- Subjects: Conservatories -- South Africa -- KwaZulu-Natal -- Design and plans Architecture -- Environmental aspects , Architecture, Modern -- 20th century
- Language: English
- Type: Thesis , Masters , MArch
- Identifier: http://hdl.handle.net/10948/39098 , vital:35042
- Description: This treatise investigates how eco-tourism can be employed to support the development of natural identity and place-making of a sacred environment through architectural intervention in the midst of an industrialised society. The principle argument of this treatise is that through the symbiosis of nature and the built environment, architecture can provide a counter-narrative to the disconnection between humans and nature. With ecotourism being a contemporary attempt to re-connect humans with our natural routes, to create awareness, a spiritual awakening and a global warming crisis intervention, this treatise will be the architectural product of conservation. The unification of ecology and architecture is critical to a contemporary definition of the natural environment. This treatise proposes the design of botanical conservatory facilities at Cathedral Peak, a tourist and research precinct in the renowned natural and cultural National Heritage Site of the Drakensberg Mountains. It presents an architecture which becomes an extension of the landscape and articulates its natural ecological systems through architectural design, while reinforcing the junction of the natural and built environment. It places the focus on integration between inside/outside spaces, in which the harmonious and symbiotic relationship can be experienced. Although it presents a contemporary architecture, it integrates various vernacular material and tectonic references, becoming a symbol of the nature of the place. The proposal is further described as a ‘cathedral of conservation’ designed as a modulated system for the simulation of particular climatic environments, with attributes drawn from the Gothic cathedral archetype in its attention to verticality and detail to materiality, and from a phenomenological perspective of place and identity as a building asserting the distinctive nature of the place. This cathedral of conservation is an architectural response to the sacredness and spirituality of the mountains, inducing a dialogue between the conservatory and the mighty Cathedral Peak which is one of the most famous natural attributes of the Drakensberg and thus the site’s most valuable vista.
- Full Text:
- Date Issued: 2016
Tide-induced variations in the fatty acid composition of estuarine particulate organic matter
- Antonio, Emily S, Richoux, Nicole B
- Authors: Antonio, Emily S , Richoux, Nicole B
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/456336 , vital:75504 , xlink:href="https://doi.org/10.1007/s12237-015-0049-x"
- Description: The particulate organic matter (POM) in hydrodynamically variable habitats such as the lower reaches of estuaries can change in its content and quality on very short time scales (example, hourly), and these changes can potentially influence higher-level consumers in river-estuary-marine systems. Estuarine water samples were collected hourly for 12 h downstream in a small river to evaluate the fatty acid composition of POM over a tidal cycle. Fatty acid constituents of POM collected during the flood tide were dominated by the saturated, higher plant and bacterial fatty acids, whereas unsaturated, polyunsaturated, essential, and diatom-associated fatty acids dominated the POM collected during the ebb tide. Elevated algal biomass (as indicated by high chlorophyll a concentrations), diatom, and freshness indices in the POM indicated enhanced fresh autochthonous-origin materials that dominated the mixed organic pool during the ebb tide compared to more degraded detritus during the flood tide. Tidal retention of organic matter and algal primary production were the most influential factors that differentiated the fatty acid composition of estuarine POM over the short time scale. The results of this study have important implications on the quality of POM at the time of sampling, especially in estuaries where mixed organic pools have multiple inputs and are strongly influenced by tidal cycles.
- Full Text:
- Date Issued: 2016
- Authors: Antonio, Emily S , Richoux, Nicole B
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/456336 , vital:75504 , xlink:href="https://doi.org/10.1007/s12237-015-0049-x"
- Description: The particulate organic matter (POM) in hydrodynamically variable habitats such as the lower reaches of estuaries can change in its content and quality on very short time scales (example, hourly), and these changes can potentially influence higher-level consumers in river-estuary-marine systems. Estuarine water samples were collected hourly for 12 h downstream in a small river to evaluate the fatty acid composition of POM over a tidal cycle. Fatty acid constituents of POM collected during the flood tide were dominated by the saturated, higher plant and bacterial fatty acids, whereas unsaturated, polyunsaturated, essential, and diatom-associated fatty acids dominated the POM collected during the ebb tide. Elevated algal biomass (as indicated by high chlorophyll a concentrations), diatom, and freshness indices in the POM indicated enhanced fresh autochthonous-origin materials that dominated the mixed organic pool during the ebb tide compared to more degraded detritus during the flood tide. Tidal retention of organic matter and algal primary production were the most influential factors that differentiated the fatty acid composition of estuarine POM over the short time scale. The results of this study have important implications on the quality of POM at the time of sampling, especially in estuaries where mixed organic pools have multiple inputs and are strongly influenced by tidal cycles.
- Full Text:
- Date Issued: 2016
Time-resolved luminescence from quartz: an overview of contemporary developments and applications
- Chithambo, Makaiko L, Pagonis, Vasilis, Ankjærgaard, Christina
- Authors: Chithambo, Makaiko L , Pagonis, Vasilis , Ankjærgaard, Christina
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124743 , vital:35658 , https://doi.org/10.1016/j.physb.2015.10.014
- Description: Time-resolved optical stimulation of luminescence has become established as a key method for measurement of optically stimulated luminescence from quartz, feldspar and α-Al2O3:C, all materials of interest in dosimetry. The aim of time-resolved optical stimulation is to separate in time the stimulation and emission of luminescence. The luminescence is stimulated from a sample using a brief light pulse and the emission monitored during stimulation in the presence of scattered stimulating light or after pulsing, over photomultiplier noise only. Although the use of the method in retrospective dosimetry has been somewhat limited, the technique has been successfully applied to study mechanisms in the processes leading up to luminescence emission. The main means for this has been the temperature dependence of the luminescence intensity as well as the luminescence lifetimes determined from time-resolved luminescence spectra. In this paper we review some key developments in theory and applications to quartz including methods of evaluating lifetimes, techniques of evaluating kinetic parameters using both the dependence of luminescence intensity and lifetime on measurement temperature, and of lifetimes on annealing temperature. We then provide an overview of some notable applications such as separation of quartz signals from a quartz–feldspar admixture and the utility of the dynamic throughput, a measure of luminescence measured as a function of the pulse width. The paper concludes with some suggestions of areas where further exploration would advance understanding of dynamics of luminescence in quartz and help address some outstanding problems in its application.
- Full Text: false
- Date Issued: 2016
- Authors: Chithambo, Makaiko L , Pagonis, Vasilis , Ankjærgaard, Christina
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124743 , vital:35658 , https://doi.org/10.1016/j.physb.2015.10.014
- Description: Time-resolved optical stimulation of luminescence has become established as a key method for measurement of optically stimulated luminescence from quartz, feldspar and α-Al2O3:C, all materials of interest in dosimetry. The aim of time-resolved optical stimulation is to separate in time the stimulation and emission of luminescence. The luminescence is stimulated from a sample using a brief light pulse and the emission monitored during stimulation in the presence of scattered stimulating light or after pulsing, over photomultiplier noise only. Although the use of the method in retrospective dosimetry has been somewhat limited, the technique has been successfully applied to study mechanisms in the processes leading up to luminescence emission. The main means for this has been the temperature dependence of the luminescence intensity as well as the luminescence lifetimes determined from time-resolved luminescence spectra. In this paper we review some key developments in theory and applications to quartz including methods of evaluating lifetimes, techniques of evaluating kinetic parameters using both the dependence of luminescence intensity and lifetime on measurement temperature, and of lifetimes on annealing temperature. We then provide an overview of some notable applications such as separation of quartz signals from a quartz–feldspar admixture and the utility of the dynamic throughput, a measure of luminescence measured as a function of the pulse width. The paper concludes with some suggestions of areas where further exploration would advance understanding of dynamics of luminescence in quartz and help address some outstanding problems in its application.
- Full Text: false
- Date Issued: 2016
Tourism potential as a tool for local economic development in Mnquma Local Municipality
- Authors: Mlondleni, Mzuyanda
- Date: 2016
- Subjects: Economic development -- South Africa -- Eastern Cape , Sustainable tourism -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/3095 , vital:20398
- Description: This research study aims to investigate what is there on offer for tourists in Mnquma Local Municipality, such as products (arts and craft, accommodation establishments and places of interests), their readiness for tourist consumption (state, accessibility), tourism routes and the understanding of communities on tourism and what can be derived from it to improve their livelihoods. This in turn will establish whether the tourism sector can be used as a tool for local economic development in the municipality. In the end, this study will make recommendations on what needs to be done in the municipality for the tourism sector to be more effective for the local communities and the municipality. The researcher has conducted a qualitative research study through the use of structured questionnaires as the data collection tool, in order to obtain information from specific population members of the concerned local municipality on tourism and LED issues. The study has been conducted from twenty three accommodation establishments in Mnquma Local Municipality. During the data collection period, the researcher discovered that these accommodation establishments are facing a number of challenges ranging from poor accessibility and signage for which the study is expected to address these in the recommendations. The study will include a purposive sample of tourism businesses in the hospitality sector in Mnquma Local Municipality. From the purposive sample, the researcher opted for total population sampling which is a type of purposive sampling technique where the researcher chooses to examine the entire population. At the end, researcher recommends that the municipality needs to address the infrastructural challenges such as roads (for accessibility to tourist sites), electricity and health centers to be able to support tourism economic activities. It also needs to ensure on the continuous hosting of events to address the seasonal nature of tourism and to market the municipality as an event destination. The researcher also recommended the establishment of partnerships with sector departments and parastatals such as SEDA, DTI, ECPTA, TEP etc. Lastly, being such a rural municipality with a rich history, culture and heritage, it is recommended that the municipality must prioritise tourism as a tool for Local Economic Development to better the lives of its population and to improve its economy.
- Full Text:
- Date Issued: 2016
- Authors: Mlondleni, Mzuyanda
- Date: 2016
- Subjects: Economic development -- South Africa -- Eastern Cape , Sustainable tourism -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/3095 , vital:20398
- Description: This research study aims to investigate what is there on offer for tourists in Mnquma Local Municipality, such as products (arts and craft, accommodation establishments and places of interests), their readiness for tourist consumption (state, accessibility), tourism routes and the understanding of communities on tourism and what can be derived from it to improve their livelihoods. This in turn will establish whether the tourism sector can be used as a tool for local economic development in the municipality. In the end, this study will make recommendations on what needs to be done in the municipality for the tourism sector to be more effective for the local communities and the municipality. The researcher has conducted a qualitative research study through the use of structured questionnaires as the data collection tool, in order to obtain information from specific population members of the concerned local municipality on tourism and LED issues. The study has been conducted from twenty three accommodation establishments in Mnquma Local Municipality. During the data collection period, the researcher discovered that these accommodation establishments are facing a number of challenges ranging from poor accessibility and signage for which the study is expected to address these in the recommendations. The study will include a purposive sample of tourism businesses in the hospitality sector in Mnquma Local Municipality. From the purposive sample, the researcher opted for total population sampling which is a type of purposive sampling technique where the researcher chooses to examine the entire population. At the end, researcher recommends that the municipality needs to address the infrastructural challenges such as roads (for accessibility to tourist sites), electricity and health centers to be able to support tourism economic activities. It also needs to ensure on the continuous hosting of events to address the seasonal nature of tourism and to market the municipality as an event destination. The researcher also recommended the establishment of partnerships with sector departments and parastatals such as SEDA, DTI, ECPTA, TEP etc. Lastly, being such a rural municipality with a rich history, culture and heritage, it is recommended that the municipality must prioritise tourism as a tool for Local Economic Development to better the lives of its population and to improve its economy.
- Full Text:
- Date Issued: 2016
Toward an automated botnet analysis framework: a darkcomet case-study
- Authors: du Bruyn, Jeremy Cecil
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/2937 , vital:20344
- Full Text:
- Date Issued: 2016
- Authors: du Bruyn, Jeremy Cecil
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/2937 , vital:20344
- Full Text:
- Date Issued: 2016
Towards an alternative spatial-based management approach for estuarine fisheries in South Africa, with a case study from the Sundays Estuary
- Authors: Kramer, Rachel
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/1007 , vital:20012
- Description: Estuaries are productive habitats and biologically important ecosystems which serve as juvenile nursery areas and feeding grounds for adults from a host of fish species. They are, however, threatened habitats, increasingly exposed to human disturbance and exploitation. The stocks of several South African estuary-dependent linefish species are now considered as either overexploited or collapsed. It is clear that their dependence on estuaries would warrant the inclusion of these ecosystems into marine reserve planning exercises. Since traditional management strategies (e.g. bag and size limit restrictions) have proven ineffective for estuarine fisheries, there is a need for alternative management measures, such as spatial and temporal restrictions, to ensure increased survival of juveniles and recovery of adult breeding populations. This thesis explored the potential for an ecosystem-based approach through the application of a rapid sustainability assessment technique, and a spatial-based management approach for an important fishery species, using conservation planning software. The Sundays Estuary, Eastern Cape, South Africa falls within the footprint of the Addo Elephant National Park, with a proposed expansion to include a marine protected area (MPA). However the estuaries resources were not considered during the planning of the proposed MPA. This study conducted an indicator-based sustainability assessment based on the principles of sustainable development. The results showed that present levels of exploitation, due to non-compliance and a lack of law enforcement are unsustainable. The sustainability of the Sundays Estuary had a low overall sustainability score of only 23.8%. With limited enforcement of estuarine fisheries regulations in South Africa, alternative management measures such as spatial regulations may provide a viable option forward. The sustainability of fishery resources depends on the comprehensive understanding of the fishery resource. Acoustic telemetry is a technique that has been widely adopted to infer habitat and area use patterns of fish species. The second component of this study made use of high resolution telemetry data collected on juvenile dusky kob Argyrosomus japonicus movements within the Sundays Estuary to conduct a scenario-based approach using Marxan conservation planning software. The best solution given by Marxan, in the form of a protected area for the conservation of juvenile A. japonicus in the Sundays Estuary was identified in the middle (starting 7km from the mouth) to the upper reaches (approximately 16km from the mouth) of the estuary, ultimately providing protection to tagged individuals for 61% of their time in the estuary. Although Marxan presented a best solution, the Sundays Estuary’s small size and shape, and minimal features used, was too simplistic to be included into a Marxan analysis. However, new methods and tools to analyse and plan spatial-based management options at this scale are currently being developed. Using the Sundays Estuary as a case study, a decision tree was then developed as a protocol to assist management address the challenges of effective estuarine management depending on the unique biological and socio-economic characteristics of individual estuaries in South Africa.
- Full Text:
- Date Issued: 2016
- Authors: Kramer, Rachel
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/1007 , vital:20012
- Description: Estuaries are productive habitats and biologically important ecosystems which serve as juvenile nursery areas and feeding grounds for adults from a host of fish species. They are, however, threatened habitats, increasingly exposed to human disturbance and exploitation. The stocks of several South African estuary-dependent linefish species are now considered as either overexploited or collapsed. It is clear that their dependence on estuaries would warrant the inclusion of these ecosystems into marine reserve planning exercises. Since traditional management strategies (e.g. bag and size limit restrictions) have proven ineffective for estuarine fisheries, there is a need for alternative management measures, such as spatial and temporal restrictions, to ensure increased survival of juveniles and recovery of adult breeding populations. This thesis explored the potential for an ecosystem-based approach through the application of a rapid sustainability assessment technique, and a spatial-based management approach for an important fishery species, using conservation planning software. The Sundays Estuary, Eastern Cape, South Africa falls within the footprint of the Addo Elephant National Park, with a proposed expansion to include a marine protected area (MPA). However the estuaries resources were not considered during the planning of the proposed MPA. This study conducted an indicator-based sustainability assessment based on the principles of sustainable development. The results showed that present levels of exploitation, due to non-compliance and a lack of law enforcement are unsustainable. The sustainability of the Sundays Estuary had a low overall sustainability score of only 23.8%. With limited enforcement of estuarine fisheries regulations in South Africa, alternative management measures such as spatial regulations may provide a viable option forward. The sustainability of fishery resources depends on the comprehensive understanding of the fishery resource. Acoustic telemetry is a technique that has been widely adopted to infer habitat and area use patterns of fish species. The second component of this study made use of high resolution telemetry data collected on juvenile dusky kob Argyrosomus japonicus movements within the Sundays Estuary to conduct a scenario-based approach using Marxan conservation planning software. The best solution given by Marxan, in the form of a protected area for the conservation of juvenile A. japonicus in the Sundays Estuary was identified in the middle (starting 7km from the mouth) to the upper reaches (approximately 16km from the mouth) of the estuary, ultimately providing protection to tagged individuals for 61% of their time in the estuary. Although Marxan presented a best solution, the Sundays Estuary’s small size and shape, and minimal features used, was too simplistic to be included into a Marxan analysis. However, new methods and tools to analyse and plan spatial-based management options at this scale are currently being developed. Using the Sundays Estuary as a case study, a decision tree was then developed as a protocol to assist management address the challenges of effective estuarine management depending on the unique biological and socio-economic characteristics of individual estuaries in South Africa.
- Full Text:
- Date Issued: 2016
Towards an industrial ecology for the Nelson Mandela Bay: Metropolitan area
- Authors: Dalindyebo, Litha
- Date: 2016
- Subjects: Industrial ecology -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/9263 , vital:26556
- Description: The aim of this study is to formulate a model of industrial ecology for wider application in the Nelson Mandel Bay (NMB) Metropole. To achieve this aim, the following objectives will be pursued: • A theoretical investigation of the concept of industrial ecology – in an attempt to establish its meaning, as well as the implications thereof. • A theoretical investigation of the operational implications of industrial ecology, including existing methodologies, such as Material Flow Analysis (MFA) and Life Cycle Assessment (LCA) that can be applied, in order to develop a system of industrial ecology between different companies. • The formulation of a methodology for application to the case study. • Presenting and discussing the research results produced by the application of the industrial ecology related methodology to the case study. • To present a synthesis of the research results of this study. This objective includes a critical evaluation of the research methodology and results, as well as some recommendations for the facilitation of industrial ecology. The methodology of the research involved conducting semi structured interviews, conducting a Material Flow Analysis and Life Cycle Analysis using SIMAPRO software. There interview with Goodyear management took place (see Appendix A), while the management at Sovereign Foods agreed to an interview however they didn’t honour the agreement. During the interview at Goodyear understanding of the operational process was achieved by conducting the interviews. The three areas that were discussed during the interview process were: 1. How the boiler works; 2. Current Air-Emission results; and 3. The process of steam generation. An MFA and an LCA on the production process of comparing the boiler functionality was conducted, so that there is an adequate understanding of the environmental performance of the two different boilers. The results of the MFA are presented as follows, namely: the goal and scope definition and the inventory results. Coal boiler versus fluidised boiler data where modelled. The modelling is done on comparing the flow of chemicals during steam production process, and which chemicals have a significant environmental impact. The LCA results looked at the basis of the symbiotic approach by identifying sustainable choices of design, production and consumption. The findings of this research have been obtained from the investigation of industrial ecology framework planning at Goodyear SA and Sovereign Foods. The findings have revealed that there is a synergy that exists between the two case-study areas. However, this is based on Goodyear changing the technology of the boiler they use (a boiler creates steam for the tyre-building process). The company will be required to use a fluidised boiler, instead of the current coal boiler. The use of the fluidised boiler will ensure that all waste streams at Goodyear will be reused and recycled, thereby creating the framework for industrial ecology. The results that are firstly drawn out of SIMAPRO is the Life Cycle Inventory. In this research, there is a flow of 1437 chemical materials and substances in the production of steam using both coal boiler and fluidized boiler. Due to the number of substance flow elements, the research has presented only the significant substances that influence the environmental performance of steam production using the two different feeder materials, which are coal and chicken matter (see Figure 4.4). In the coal boiler process, sulfur comprises the largest amount of chemical substance. The other top five chemical components that contribute to the steam production process are: nickel, chromium, arsenic and iodosulfuron-methyl-sodium. The scale of figure 4.4 is reduced to show the various number of chemical flows found in the steam production process through SIMAPRO software. The Life Cycle Assessment (LCA) results were presented looking at namely the following characterization, normalization, weighting, single score and damage assessment (see Figure 4.7 – 4.10 p87 – p90). The figures are presented as taken directly from the reports drawn from the SIMAPRO software. Figure 4.7 gives the characterisation results up to 100%, where 0% has a minimal environmental effect; whereas 100% has the most significant environmental effect. Oxidation of coal is compared versus the oxidation of chicken matter, the coal boiler process has higher environmental impacts. Figure 4.8 shows the normalisation results of the coal boiler versus the fluidised boiler for the functional unit steam production. The environmental degradation under normalisation between the two boilers are measured, based on three parameters, namely: human health, ecosystems and resources. In all three parameters that are measured under normalisation, the production of steam using the coal boiler has the highest impacts. The weighting results in Figure 4.9 show a mirror image of the normalisation results. Finally, a gap analysis of the theoretical requirements for industrial ecology is displayed versus what currently exists in the case study area. The gap analysis will assist in the development of recommendations. These will be presented in the next chapter. A gap analysis of findings is discussed leading into the synthesis. The value of this research is that the baseline data of planning for an industrial ecology create a platform that can be used for implementing an industrial ecology between Goodyear SA and Sovereign Foods. This will, in time, have wider applications for the entire NMB metropole.
- Full Text:
- Date Issued: 2016
- Authors: Dalindyebo, Litha
- Date: 2016
- Subjects: Industrial ecology -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/9263 , vital:26556
- Description: The aim of this study is to formulate a model of industrial ecology for wider application in the Nelson Mandel Bay (NMB) Metropole. To achieve this aim, the following objectives will be pursued: • A theoretical investigation of the concept of industrial ecology – in an attempt to establish its meaning, as well as the implications thereof. • A theoretical investigation of the operational implications of industrial ecology, including existing methodologies, such as Material Flow Analysis (MFA) and Life Cycle Assessment (LCA) that can be applied, in order to develop a system of industrial ecology between different companies. • The formulation of a methodology for application to the case study. • Presenting and discussing the research results produced by the application of the industrial ecology related methodology to the case study. • To present a synthesis of the research results of this study. This objective includes a critical evaluation of the research methodology and results, as well as some recommendations for the facilitation of industrial ecology. The methodology of the research involved conducting semi structured interviews, conducting a Material Flow Analysis and Life Cycle Analysis using SIMAPRO software. There interview with Goodyear management took place (see Appendix A), while the management at Sovereign Foods agreed to an interview however they didn’t honour the agreement. During the interview at Goodyear understanding of the operational process was achieved by conducting the interviews. The three areas that were discussed during the interview process were: 1. How the boiler works; 2. Current Air-Emission results; and 3. The process of steam generation. An MFA and an LCA on the production process of comparing the boiler functionality was conducted, so that there is an adequate understanding of the environmental performance of the two different boilers. The results of the MFA are presented as follows, namely: the goal and scope definition and the inventory results. Coal boiler versus fluidised boiler data where modelled. The modelling is done on comparing the flow of chemicals during steam production process, and which chemicals have a significant environmental impact. The LCA results looked at the basis of the symbiotic approach by identifying sustainable choices of design, production and consumption. The findings of this research have been obtained from the investigation of industrial ecology framework planning at Goodyear SA and Sovereign Foods. The findings have revealed that there is a synergy that exists between the two case-study areas. However, this is based on Goodyear changing the technology of the boiler they use (a boiler creates steam for the tyre-building process). The company will be required to use a fluidised boiler, instead of the current coal boiler. The use of the fluidised boiler will ensure that all waste streams at Goodyear will be reused and recycled, thereby creating the framework for industrial ecology. The results that are firstly drawn out of SIMAPRO is the Life Cycle Inventory. In this research, there is a flow of 1437 chemical materials and substances in the production of steam using both coal boiler and fluidized boiler. Due to the number of substance flow elements, the research has presented only the significant substances that influence the environmental performance of steam production using the two different feeder materials, which are coal and chicken matter (see Figure 4.4). In the coal boiler process, sulfur comprises the largest amount of chemical substance. The other top five chemical components that contribute to the steam production process are: nickel, chromium, arsenic and iodosulfuron-methyl-sodium. The scale of figure 4.4 is reduced to show the various number of chemical flows found in the steam production process through SIMAPRO software. The Life Cycle Assessment (LCA) results were presented looking at namely the following characterization, normalization, weighting, single score and damage assessment (see Figure 4.7 – 4.10 p87 – p90). The figures are presented as taken directly from the reports drawn from the SIMAPRO software. Figure 4.7 gives the characterisation results up to 100%, where 0% has a minimal environmental effect; whereas 100% has the most significant environmental effect. Oxidation of coal is compared versus the oxidation of chicken matter, the coal boiler process has higher environmental impacts. Figure 4.8 shows the normalisation results of the coal boiler versus the fluidised boiler for the functional unit steam production. The environmental degradation under normalisation between the two boilers are measured, based on three parameters, namely: human health, ecosystems and resources. In all three parameters that are measured under normalisation, the production of steam using the coal boiler has the highest impacts. The weighting results in Figure 4.9 show a mirror image of the normalisation results. Finally, a gap analysis of the theoretical requirements for industrial ecology is displayed versus what currently exists in the case study area. The gap analysis will assist in the development of recommendations. These will be presented in the next chapter. A gap analysis of findings is discussed leading into the synthesis. The value of this research is that the baseline data of planning for an industrial ecology create a platform that can be used for implementing an industrial ecology between Goodyear SA and Sovereign Foods. This will, in time, have wider applications for the entire NMB metropole.
- Full Text:
- Date Issued: 2016
Towards determining the dietary lysine requirement in the South African abalone, Haliotis midae
- Authors: Lloyd, Kyle Everett
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/1024 , vital:20014
- Description: Animals generally do not have a requirement for protein, but instead have a requirement for specific essential amino acids (EAAs) and non-essential amino acids (NEAAs). The NEAAs are those that can be synthesised by the animal, however, EAAs cannot be synthesised and must therefore be supplied as part of the diet. When these amino acids (AAs) are supplied in the correct ratios and with the correct level of digestible energy, nutritionists can maximise somatic growth from proteins. This has resulted in increased research into the use of crystalline AAs as a tool in feed formulation research in order to quantify the AA requirements in aquaculture species, and allow for alternative protein sources (other than fishmeal) to be utilised. In common with other water soluble nutrients, leaching of crystalline AAs from diets prior to ingestion is of concern in an aquatic environment. Microencapsulation techniques have been successfully employed to restrict micronutrient leaching, and improve ingestion rates. In this research, LysiPEARL™ (Kemin®) was used as a means to determine the lysine requirement in Haliotis. midae. This encapsulated lysine product is used in the dairy cattle industry as an effective source of rumen bypass for intestinal release of lysine. It has previously been proposed that crystalline AAs are not suitable for AA studies in H. midae due to the slow feeding rates of the species as well as the solubility of these AAs. However, 90.00 % of supplemented lysine was maintained in this study after a six hour period of leaching, showing that if effective microencapsulation techniques are used, it is possible to use crystalline amino acids to supplement protein bound lysine in abalone feeds. Six isoenergetic (15.90 MJ/kg), isolipidic (6.00 %) and isonitrogenous (29.00 %) diets enriched with 5.52, 6.40, 7.28, 8.14, 9.00 and 9.86 % lysine (as a % of protein) were fed to triplicate groups of 20 H. midae (20.41 ± 1.95 mm SL 1.51 ± 0.44 g w.wt) for 90 days. Wet weight and shell length measurements were taken every 30 days and specific growth rate (SGR) (% body weight.day-1), feed conversion ratio (FCR), protein efficiency ratio (PER), feed consumption (% body weight.day-1) and condition factor were calculated for each dietary treatment. Linear regression showed that FCR increased as dietary lysine increased (Regression analysis, p=0.031), and that PER reduced as dietary lysine increased (Regression analysis, p=0.026). Feed consumption also increased as dietary lysine increased (Regression analysis, p<0.001). The inclusion of lysine at 7.28 % of the total protein in the diet resulted in significantly superior SGR (0.57±0.01 % body weight.day-1) to that of 5.52 % (0.42±0.05 % body weight.day-1), FCR (1.51±0.05) to that of 8.14 % (1.99±0.21) and PER (2.45±0.07) to that of 8.14 % (1.99±0.18; ANOVA, p<0.05). There was a significant difference found in feed consumption (% body wt.d-1), with consumption increasing significantly between the first three dietary treatments and the last three dietary treatments (ANOVA, p<0.001). There was no significant improvement in SGR when dietary lysine increased above 7.28 % of the dietary protein in the diet, indicating that dietary lysine requirement was being met at 7.28 %, after which excess lysine promoted no growth response. The diet producing the best SGR, PER and FCR in this study was diet 3 which had a measured lysine content of 6.90 %. The results of the present study suggest that the lysine requirement in H. midae is in the range of 6.00 - 7.00 % of dietary protein. From these data amino acid ratios were used to estimate optimum inclusion levels of other essential amino acids. However, lysine availability in LysiPEARL™ may have resulted in over estimations due to the lipid encapsulation technique used, and haliotids limited ability to efficiently digest lipids. For this reason EAA requirements were suggested based on three different hypothetical scenarios of lysine availability from LysiPEARL™.
- Full Text:
- Date Issued: 2016
- Authors: Lloyd, Kyle Everett
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/1024 , vital:20014
- Description: Animals generally do not have a requirement for protein, but instead have a requirement for specific essential amino acids (EAAs) and non-essential amino acids (NEAAs). The NEAAs are those that can be synthesised by the animal, however, EAAs cannot be synthesised and must therefore be supplied as part of the diet. When these amino acids (AAs) are supplied in the correct ratios and with the correct level of digestible energy, nutritionists can maximise somatic growth from proteins. This has resulted in increased research into the use of crystalline AAs as a tool in feed formulation research in order to quantify the AA requirements in aquaculture species, and allow for alternative protein sources (other than fishmeal) to be utilised. In common with other water soluble nutrients, leaching of crystalline AAs from diets prior to ingestion is of concern in an aquatic environment. Microencapsulation techniques have been successfully employed to restrict micronutrient leaching, and improve ingestion rates. In this research, LysiPEARL™ (Kemin®) was used as a means to determine the lysine requirement in Haliotis. midae. This encapsulated lysine product is used in the dairy cattle industry as an effective source of rumen bypass for intestinal release of lysine. It has previously been proposed that crystalline AAs are not suitable for AA studies in H. midae due to the slow feeding rates of the species as well as the solubility of these AAs. However, 90.00 % of supplemented lysine was maintained in this study after a six hour period of leaching, showing that if effective microencapsulation techniques are used, it is possible to use crystalline amino acids to supplement protein bound lysine in abalone feeds. Six isoenergetic (15.90 MJ/kg), isolipidic (6.00 %) and isonitrogenous (29.00 %) diets enriched with 5.52, 6.40, 7.28, 8.14, 9.00 and 9.86 % lysine (as a % of protein) were fed to triplicate groups of 20 H. midae (20.41 ± 1.95 mm SL 1.51 ± 0.44 g w.wt) for 90 days. Wet weight and shell length measurements were taken every 30 days and specific growth rate (SGR) (% body weight.day-1), feed conversion ratio (FCR), protein efficiency ratio (PER), feed consumption (% body weight.day-1) and condition factor were calculated for each dietary treatment. Linear regression showed that FCR increased as dietary lysine increased (Regression analysis, p=0.031), and that PER reduced as dietary lysine increased (Regression analysis, p=0.026). Feed consumption also increased as dietary lysine increased (Regression analysis, p<0.001). The inclusion of lysine at 7.28 % of the total protein in the diet resulted in significantly superior SGR (0.57±0.01 % body weight.day-1) to that of 5.52 % (0.42±0.05 % body weight.day-1), FCR (1.51±0.05) to that of 8.14 % (1.99±0.21) and PER (2.45±0.07) to that of 8.14 % (1.99±0.18; ANOVA, p<0.05). There was a significant difference found in feed consumption (% body wt.d-1), with consumption increasing significantly between the first three dietary treatments and the last three dietary treatments (ANOVA, p<0.001). There was no significant improvement in SGR when dietary lysine increased above 7.28 % of the dietary protein in the diet, indicating that dietary lysine requirement was being met at 7.28 %, after which excess lysine promoted no growth response. The diet producing the best SGR, PER and FCR in this study was diet 3 which had a measured lysine content of 6.90 %. The results of the present study suggest that the lysine requirement in H. midae is in the range of 6.00 - 7.00 % of dietary protein. From these data amino acid ratios were used to estimate optimum inclusion levels of other essential amino acids. However, lysine availability in LysiPEARL™ may have resulted in over estimations due to the lipid encapsulation technique used, and haliotids limited ability to efficiently digest lipids. For this reason EAA requirements were suggested based on three different hypothetical scenarios of lysine availability from LysiPEARL™.
- Full Text:
- Date Issued: 2016
Towards malicious network activity mitigation through subnet reputation analysis
- Herbert, Alan, Irwin, Barry V W
- Authors: Herbert, Alan , Irwin, Barry V W
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427799 , vital:72463 , https://www.researchgate.net/profile/Barry-Ir-win/publication/327622788_Towards_Malicious_Network_Activity_Mitigation_through_Subnet_Reputation_Analysis/links/5b9a1a88458515310583fda6/Towards-Malicious-Network-Activity-Mitigation-through-Subnet-Reputation-Analysis.pdf
- Description: Analysis technologies that focus on partial packet rather than full packet analysis have shown promise in detection of malicious activity on net-works. NetFlow is one such emergent protocol that is used to log net-work flows through summarizing key features of them. These logs can then be exported to external NetFlow sinks and proper configuration can see effective bandwidth bottleneck mitigation occurring on net-works. Furthermore, each NetFlow source node is configurable with its own unique ID number. This feature enables a system that knows where a NetFlow source node ID number resides physically to say which network flows are occurring from which physical locations irre-spective of the IP addresses involved in these network flows.
- Full Text:
- Date Issued: 2016
- Authors: Herbert, Alan , Irwin, Barry V W
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427799 , vital:72463 , https://www.researchgate.net/profile/Barry-Ir-win/publication/327622788_Towards_Malicious_Network_Activity_Mitigation_through_Subnet_Reputation_Analysis/links/5b9a1a88458515310583fda6/Towards-Malicious-Network-Activity-Mitigation-through-Subnet-Reputation-Analysis.pdf
- Description: Analysis technologies that focus on partial packet rather than full packet analysis have shown promise in detection of malicious activity on net-works. NetFlow is one such emergent protocol that is used to log net-work flows through summarizing key features of them. These logs can then be exported to external NetFlow sinks and proper configuration can see effective bandwidth bottleneck mitigation occurring on net-works. Furthermore, each NetFlow source node is configurable with its own unique ID number. This feature enables a system that knows where a NetFlow source node ID number resides physically to say which network flows are occurring from which physical locations irre-spective of the IP addresses involved in these network flows.
- Full Text:
- Date Issued: 2016
Trade liberalisation, the real exchange rate and sectoral employment : a case study of South Africa
- Authors: Sibanda, Kin
- Date: 2016
- Subjects: Foreign exchange rates Employment (Economic theory) Free trade -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/12777 , vital:39360
- Description: This study examined the relationship between trade liberalisation, the real exchange rate and sectoral employment in South Africa for the period 1994 to 2014. Firstly, using quarterly time series data, the Autoregressive Distributed Lag (ARDL) technique was employed to formally check if South African real exchange rates are responsive to trade liberalisation. This was done to see if trade liberalisation impacts real exchange rates in South Africa, to the extent that they cannot be controlled concurrently in the subsequent models. Based on the ARDL results, trade liberalisation does not have a significant effect on the exchange rate. However, when the real exchange rate is an independent variable of trade liberalisation, the results show that real exchange rates affect trade, specifically the export propensity index. The next step was to assess the impact of trade liberalisation and real exchange rate on sectoral employment using quarterly panel data for South Africa from 1994 to 2014 controlling for both sector-specific and macro-economic variables. The study employed diverse panel data analysis techniques to separate the sectoral effects, starting with broad sectors followed by the disaggregated sectors, to identify the sectors most affected by real exchange rates and trade liberalisation. The Generalised method of Moments (GMM) results reveal that a unit increase in exchange rate (implying appreciation), causes employment to go down by about 9 percent in South Africa. The same relationship is depicted from the Pooled Mean Group (PMG) estimations in both the short run and long run. Random coefficients (betas) show that the real exchange rate negatively affects the primary and secondary sector with a positive but insignificant effect on the tertiary sector. The sub-sectors negatively hit hard by real exchange rates are communication, mining and transport. The results also show that trade liberalisation is linked to both job destruction and job creation. The static models reveal that trade openness has a statistically positive and significant impact on employment in the short run while the PMG estimator results show that the effect is negative and only significant in the short run. The dynamic models (GMM and PMG) showed trade liberalisation (as proxied by trade openness and import propensity) has a statistical and significantly positive short run impact on employment. This implies that selective trade liberalisation strategies are needed in order for South Africa to maximise the gains from trade.
- Full Text:
- Date Issued: 2016
- Authors: Sibanda, Kin
- Date: 2016
- Subjects: Foreign exchange rates Employment (Economic theory) Free trade -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/12777 , vital:39360
- Description: This study examined the relationship between trade liberalisation, the real exchange rate and sectoral employment in South Africa for the period 1994 to 2014. Firstly, using quarterly time series data, the Autoregressive Distributed Lag (ARDL) technique was employed to formally check if South African real exchange rates are responsive to trade liberalisation. This was done to see if trade liberalisation impacts real exchange rates in South Africa, to the extent that they cannot be controlled concurrently in the subsequent models. Based on the ARDL results, trade liberalisation does not have a significant effect on the exchange rate. However, when the real exchange rate is an independent variable of trade liberalisation, the results show that real exchange rates affect trade, specifically the export propensity index. The next step was to assess the impact of trade liberalisation and real exchange rate on sectoral employment using quarterly panel data for South Africa from 1994 to 2014 controlling for both sector-specific and macro-economic variables. The study employed diverse panel data analysis techniques to separate the sectoral effects, starting with broad sectors followed by the disaggregated sectors, to identify the sectors most affected by real exchange rates and trade liberalisation. The Generalised method of Moments (GMM) results reveal that a unit increase in exchange rate (implying appreciation), causes employment to go down by about 9 percent in South Africa. The same relationship is depicted from the Pooled Mean Group (PMG) estimations in both the short run and long run. Random coefficients (betas) show that the real exchange rate negatively affects the primary and secondary sector with a positive but insignificant effect on the tertiary sector. The sub-sectors negatively hit hard by real exchange rates are communication, mining and transport. The results also show that trade liberalisation is linked to both job destruction and job creation. The static models reveal that trade openness has a statistically positive and significant impact on employment in the short run while the PMG estimator results show that the effect is negative and only significant in the short run. The dynamic models (GMM and PMG) showed trade liberalisation (as proxied by trade openness and import propensity) has a statistical and significantly positive short run impact on employment. This implies that selective trade liberalisation strategies are needed in order for South Africa to maximise the gains from trade.
- Full Text:
- Date Issued: 2016
Traditional and cultural practices and the rights of women : a study of widowhood practices among the Akans in Ghana
- Authors: Afari-Twumasi, Lucy
- Date: 2016
- Subjects: Widows -- Legal status, laws, etc. -- Ghana Widowhood -- Ghana Akan (African people) -- Social life and customs
- Language: English
- Type: Thesis , Masters , MPhil
- Identifier: http://hdl.handle.net/10353/2844 , vital:28106
- Description: The study investigates the human rights violations that underlie widowhood practices in Cape Coast and Komenda in the Central Region of Ghana. Review of the relevant literature on widowhood practices suggests that widowhood practices are a global cultural phenomenon, which is not confined to Sub-Sahara Africa. A survey of relevant studies on the phenomenon suggests that there are two competing perceptions on African widowhood practices: (1) a dominant negative perspective and (2) a minor positive perspective. The dominant negative perspective, which receives overwhelming research attention, focuses only on the negative characteristics of widowhood while the minor positive perspective which receives scanty research attention, rejects the criticisms levelled against widowhood practices as being externally influenced by Christianity and Western Feminism. Various stakeholders within the Akan community were given an opportunity to retell their own versions of widowhood practices. In order to achieve this purpose, the research extracted competing narratives from all the multiple sample subgroups of the proposed study: widows; widow family heads; chiefs; widowhood ritual practitioners; elderly female supervisors of widowhood practices; an official from the Commission for Human Rights and Administrative Justice (CHRAJ); an official from the Ministry of Women and Children Affairs (MOWAC); and an official from the Domestic Violence and Victims Support Unit (DOVVSU) of Ghana. The study found out that despite legislative intervention and policy frameworks, the practice still persist among the Akan communities in Ghana. The reasons for the continued existence of such rituals are explained followed by recommendations for possible solutions.
- Full Text:
- Date Issued: 2016
- Authors: Afari-Twumasi, Lucy
- Date: 2016
- Subjects: Widows -- Legal status, laws, etc. -- Ghana Widowhood -- Ghana Akan (African people) -- Social life and customs
- Language: English
- Type: Thesis , Masters , MPhil
- Identifier: http://hdl.handle.net/10353/2844 , vital:28106
- Description: The study investigates the human rights violations that underlie widowhood practices in Cape Coast and Komenda in the Central Region of Ghana. Review of the relevant literature on widowhood practices suggests that widowhood practices are a global cultural phenomenon, which is not confined to Sub-Sahara Africa. A survey of relevant studies on the phenomenon suggests that there are two competing perceptions on African widowhood practices: (1) a dominant negative perspective and (2) a minor positive perspective. The dominant negative perspective, which receives overwhelming research attention, focuses only on the negative characteristics of widowhood while the minor positive perspective which receives scanty research attention, rejects the criticisms levelled against widowhood practices as being externally influenced by Christianity and Western Feminism. Various stakeholders within the Akan community were given an opportunity to retell their own versions of widowhood practices. In order to achieve this purpose, the research extracted competing narratives from all the multiple sample subgroups of the proposed study: widows; widow family heads; chiefs; widowhood ritual practitioners; elderly female supervisors of widowhood practices; an official from the Commission for Human Rights and Administrative Justice (CHRAJ); an official from the Ministry of Women and Children Affairs (MOWAC); and an official from the Domestic Violence and Victims Support Unit (DOVVSU) of Ghana. The study found out that despite legislative intervention and policy frameworks, the practice still persist among the Akan communities in Ghana. The reasons for the continued existence of such rituals are explained followed by recommendations for possible solutions.
- Full Text:
- Date Issued: 2016
Transcription factor motif quality assessment requires systematic comparative analysis
- Kibet, Cabel K, Machanick, Philip
- Authors: Kibet, Cabel K , Machanick, Philip
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/439366 , vital:73570 , https://f1000research.com/articles/4-1429
- Description: Transcription factor (TF) binding site prediction remains a challenge in gene regulatory research due to degeneracy and potential variability in binding sites in the genome. Dozens of algorithms designed to learn binding models (motifs) have generated many motifs available in research papers with a subset making it to databases like JASPAR, UniPROBE and Transfac. The presence of many versions of motifs from the various databases for a single TF and the lack of a standardized assessment technique makes it difficult for biologists to make an appropriate choice of binding model and for algorithm developers to benchmark, test and improve on their models. In this study, we review and evaluate the approaches in use, highlight differences and demonstrate the difficulty of defining a standardized motif assessment approach. We review scoring functions, motif length, test data and the type of performance metrics used in prior studies as some of the factors that influence the outcome of a motif assessment. We show that the scoring functions and statistics used in motif assessment influence ranking of motifs in a TF-specific manner. We also show that TF binding specificity can vary by source of genomic binding data. We also demonstrate that information content of a motif is not in isolation a measure of motif quality but is influenced by TF binding behaviour. We conclude that there is a need for an easy-to-use tool that presents all available evidence for a comparative analysis.
- Full Text:
- Date Issued: 2016
- Authors: Kibet, Cabel K , Machanick, Philip
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/439366 , vital:73570 , https://f1000research.com/articles/4-1429
- Description: Transcription factor (TF) binding site prediction remains a challenge in gene regulatory research due to degeneracy and potential variability in binding sites in the genome. Dozens of algorithms designed to learn binding models (motifs) have generated many motifs available in research papers with a subset making it to databases like JASPAR, UniPROBE and Transfac. The presence of many versions of motifs from the various databases for a single TF and the lack of a standardized assessment technique makes it difficult for biologists to make an appropriate choice of binding model and for algorithm developers to benchmark, test and improve on their models. In this study, we review and evaluate the approaches in use, highlight differences and demonstrate the difficulty of defining a standardized motif assessment approach. We review scoring functions, motif length, test data and the type of performance metrics used in prior studies as some of the factors that influence the outcome of a motif assessment. We show that the scoring functions and statistics used in motif assessment influence ranking of motifs in a TF-specific manner. We also show that TF binding specificity can vary by source of genomic binding data. We also demonstrate that information content of a motif is not in isolation a measure of motif quality but is influenced by TF binding behaviour. We conclude that there is a need for an easy-to-use tool that presents all available evidence for a comparative analysis.
- Full Text:
- Date Issued: 2016
Transcription factor motif quality assessment requires systematic comparative analysis [version 2; referees: 2 approved]
- Kibet, Caleb K, Machanick, Philip
- Authors: Kibet, Caleb K , Machanick, Philip
- Date: 2016
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/61169 , vital:27987 , http://dx.doi.org/10.12688/f1000research.7408.2
- Description: Transcription factor (TF) binding site prediction remains a challenge in gene regulatory research due to degeneracy and potential variability in binding sites in the genome. Dozens of algorithms designed to learn binding models (motifs) have generated many motifs available in research papers with a subset making it to databases like JASPAR, UniPROBE and Transfac. The presence of many versions of motifs from the various databases for a single TF and the lack of a standardized assessment technique makes it difficult for biologists to make an appropriate choice of binding model and for algorithm developers to benchmark, test and improve on their models. In this study, we review and evaluate the approaches in use, highlight differences and demonstrate the difficulty of defining a standardized motif assessment approach. We review scoring functions, motif length, test data and the type of performance metrics used in prior studies as some of the factors that influence the outcome of a motif assessment. We show that the scoring functions and statistics used in motif assessment influence ranking of motifs in a TF-specific manner. We also show that TF binding specificity can vary by source of genomic binding data. We also demonstrate that information content of a motif is not in isolation a measure of motif quality but is influenced by TF binding behaviour. We conclude that there is a need for an easy-to-use tool that presents all available evidence for a comparative analysis.
- Full Text:
- Date Issued: 2016
- Authors: Kibet, Caleb K , Machanick, Philip
- Date: 2016
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/61169 , vital:27987 , http://dx.doi.org/10.12688/f1000research.7408.2
- Description: Transcription factor (TF) binding site prediction remains a challenge in gene regulatory research due to degeneracy and potential variability in binding sites in the genome. Dozens of algorithms designed to learn binding models (motifs) have generated many motifs available in research papers with a subset making it to databases like JASPAR, UniPROBE and Transfac. The presence of many versions of motifs from the various databases for a single TF and the lack of a standardized assessment technique makes it difficult for biologists to make an appropriate choice of binding model and for algorithm developers to benchmark, test and improve on their models. In this study, we review and evaluate the approaches in use, highlight differences and demonstrate the difficulty of defining a standardized motif assessment approach. We review scoring functions, motif length, test data and the type of performance metrics used in prior studies as some of the factors that influence the outcome of a motif assessment. We show that the scoring functions and statistics used in motif assessment influence ranking of motifs in a TF-specific manner. We also show that TF binding specificity can vary by source of genomic binding data. We also demonstrate that information content of a motif is not in isolation a measure of motif quality but is influenced by TF binding behaviour. We conclude that there is a need for an easy-to-use tool that presents all available evidence for a comparative analysis.
- Full Text:
- Date Issued: 2016