Time motion analyses of one-day international and twenty/20 matches and the development of a simulated batting protocol specifically designed for female cricket players
- Authors: Munro, Catherine
- Date: 2019
- Subjects: Women cricket players , Cricket -- Batting , Cricket -- Coaching , Cricket -- Physiological aspects
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/76342 , vital:30550
- Description: Background: Accurate and reliable in-game data is fundamental when designing effective batting training. A simulated batting protocol that could aid research and training has not been specifically designed for female cricketers because of a distinct lack of empirical in-game data for the women’s version of the game. Objective: The purpose of this study was to quantify the motion demands and run-breakdown of a century and T20 half-century for women’s cricket matches to establish a simulated batting protocol specifically designed for female batters. Method: Time-motion analyses of four one-day international and six T20 innings were conducted on international cricket matches played around the world between 2012 and 2017. The innings was divided into the bowling and batting innings. The ODI innings that met the criterion of 100 runs scored and T20 innings with scores above 50 runs were used in the run breakdown, which included scores from the top 10 countries ranked by the ICC. The time-motion analyses and century breakdown were utilised in the establishment of a simulated batting protocol. The simulated batting protocol for female batters was created/developed by utilising the method designed by Houghton et al., (2011), who developed the BATEX© protocol. Results: The time-motion analyses indicated that the mean duration of an ODI innings was 169 minutes. An over lasted 2.45 minutes, with 24.86 seconds between each delivery and 55 seconds between each over. When the bowling side changed to a new bowler, it was 1.12 minutes between overs. The mean score for the first power play in an ODI was 41 runs with 1.38 wickets being taken. The mean score during the second power play was 28 runs with 0.714 wickets being taken. The T20 bowling innings lasted 75.50 minutes, with an over lasting 2.52 minutes with 25.58 seconds between deliveries. The mean score in the T20 batting innings was 122 runs. During the power play, which lasted 24.35 minutes, 37 runs were scored with 1.45 wickets being taken. The simulated batting innings was then designed as four stages lasting the duration of a typical women’s century. Each stage was based on theoretical phases of play that may occur during a batting innings. Conclusion: The study indicated that the women’s game has different movement requirements compared to the men’s game in both the ODI and T20 formats. Further, the demands differ depending on the country that is playing. A training and research protocol specifically designed for female batters is an important outcome.
- Full Text:
- Date Issued: 2019
- Authors: Munro, Catherine
- Date: 2019
- Subjects: Women cricket players , Cricket -- Batting , Cricket -- Coaching , Cricket -- Physiological aspects
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/76342 , vital:30550
- Description: Background: Accurate and reliable in-game data is fundamental when designing effective batting training. A simulated batting protocol that could aid research and training has not been specifically designed for female cricketers because of a distinct lack of empirical in-game data for the women’s version of the game. Objective: The purpose of this study was to quantify the motion demands and run-breakdown of a century and T20 half-century for women’s cricket matches to establish a simulated batting protocol specifically designed for female batters. Method: Time-motion analyses of four one-day international and six T20 innings were conducted on international cricket matches played around the world between 2012 and 2017. The innings was divided into the bowling and batting innings. The ODI innings that met the criterion of 100 runs scored and T20 innings with scores above 50 runs were used in the run breakdown, which included scores from the top 10 countries ranked by the ICC. The time-motion analyses and century breakdown were utilised in the establishment of a simulated batting protocol. The simulated batting protocol for female batters was created/developed by utilising the method designed by Houghton et al., (2011), who developed the BATEX© protocol. Results: The time-motion analyses indicated that the mean duration of an ODI innings was 169 minutes. An over lasted 2.45 minutes, with 24.86 seconds between each delivery and 55 seconds between each over. When the bowling side changed to a new bowler, it was 1.12 minutes between overs. The mean score for the first power play in an ODI was 41 runs with 1.38 wickets being taken. The mean score during the second power play was 28 runs with 0.714 wickets being taken. The T20 bowling innings lasted 75.50 minutes, with an over lasting 2.52 minutes with 25.58 seconds between deliveries. The mean score in the T20 batting innings was 122 runs. During the power play, which lasted 24.35 minutes, 37 runs were scored with 1.45 wickets being taken. The simulated batting innings was then designed as four stages lasting the duration of a typical women’s century. Each stage was based on theoretical phases of play that may occur during a batting innings. Conclusion: The study indicated that the women’s game has different movement requirements compared to the men’s game in both the ODI and T20 formats. Further, the demands differ depending on the country that is playing. A training and research protocol specifically designed for female batters is an important outcome.
- Full Text:
- Date Issued: 2019
Time-resolved luminescence: progress in development of theory and analytical methods
- Authors: Chithambo, Makaiko L
- Date: 2019
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/105403 , vital:32509 , https://doi.org/10.1142/9781786345790_0007
- Description: Time-resolved optical stimulation is an important method for measurement of optically stimulated luminescence. The aim of time-resolved optical stimulation is to separate the stimulation and emission of luminescence in time. The luminescence is stimulated from a sample using a short light pulse of constant intensity. The ensuing luminescence can be monitored either during stimulation in the presence of scattered stimulating light, or after the light-pulse. The time-resolved luminescence spectrum produced in this way can be resolved into components, each with a distinct lifetime. The lifetimes are linked to physical processes of luminescence. Time-resolved optical stimulation has thus been used to study dynamics of luminescence in various materials, particularly ones of interest in dosimetry such as quartz, feldspar, α-Al2O3:C and BeO. This chapter will review the theory of time-resolved luminescence, look at the instrumentation involved and discuss advances in analytical methods of time-resolved luminescence spectra.
- Full Text: false
- Date Issued: 2019
- Authors: Chithambo, Makaiko L
- Date: 2019
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/105403 , vital:32509 , https://doi.org/10.1142/9781786345790_0007
- Description: Time-resolved optical stimulation is an important method for measurement of optically stimulated luminescence. The aim of time-resolved optical stimulation is to separate the stimulation and emission of luminescence in time. The luminescence is stimulated from a sample using a short light pulse of constant intensity. The ensuing luminescence can be monitored either during stimulation in the presence of scattered stimulating light, or after the light-pulse. The time-resolved luminescence spectrum produced in this way can be resolved into components, each with a distinct lifetime. The lifetimes are linked to physical processes of luminescence. Time-resolved optical stimulation has thus been used to study dynamics of luminescence in various materials, particularly ones of interest in dosimetry such as quartz, feldspar, α-Al2O3:C and BeO. This chapter will review the theory of time-resolved luminescence, look at the instrumentation involved and discuss advances in analytical methods of time-resolved luminescence spectra.
- Full Text: false
- Date Issued: 2019
Timing of the incidence of tax in suspensive sale agreements and agreements with suspensive conditions
- Authors: Zondi, Bonginkosi
- Date: 2019
- Subjects: Tax administration and procedure -- South Africa , Taxation -- Law and legislation -- South Africa Taxation -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10948/44269 , vital:37144
- Description: This study critically examines suspensive sale agreements and agreements subject to suspensive conditions in the South African taxation system. It examines challenges associated with the application of the disposal rules in the context of the Income Tax Act No. 58 of 1962, which includes capital gains tax, and Value-Added Tax Act No. 89 of 1991 relating to these types of agreements. The study also looks at those aspects in which these agreements generally differ and concur. As one of its areas of focus, the study inter alia makes a comparison of the South African approach to the timing of the tax incidence under these agreements, to the approaches adopted by other countries, namely Canada, Zimbabwe and the United States of America (USA).
- Full Text:
- Date Issued: 2019
- Authors: Zondi, Bonginkosi
- Date: 2019
- Subjects: Tax administration and procedure -- South Africa , Taxation -- Law and legislation -- South Africa Taxation -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10948/44269 , vital:37144
- Description: This study critically examines suspensive sale agreements and agreements subject to suspensive conditions in the South African taxation system. It examines challenges associated with the application of the disposal rules in the context of the Income Tax Act No. 58 of 1962, which includes capital gains tax, and Value-Added Tax Act No. 89 of 1991 relating to these types of agreements. The study also looks at those aspects in which these agreements generally differ and concur. As one of its areas of focus, the study inter alia makes a comparison of the South African approach to the timing of the tax incidence under these agreements, to the approaches adopted by other countries, namely Canada, Zimbabwe and the United States of America (USA).
- Full Text:
- Date Issued: 2019
TiRiFiG, a graphical 3D kinematic modelling tool
- Authors: Twum, Samuel Nyarko
- Date: 2019
- Subjects: Tilted Ring Fitting GUI , Astronomy -- Observations , Galaxies -- Observations , Galaxies -- Measurement , Galaxies -- Measurement -- Data processing , Kinematics
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/76409 , vital:30558
- Description: Galaxy kinematics is of crucial importance to understanding the structure, formation and evolution of galaxies. The studies of mass distributions giving rise to the missing mass problem, first raised by Zwicky (1933), give us an insight into dark matter distributions which are tightly linked to cosmology. Neutral hydrogen (H i) has been widely used as a tracer in the kinematic studies of galaxies. The Square Kilometre Array (SKA) and its precursors will produce large Hi datasets which will require kinematic modelling tools to extract kinematic parameters such as rotation curves. TiRiFiC (Józsa et al., 2007) is an example of such a tool for 3D kinematic modelling of resolved spectroscopic observations of rotating disks in terms of the tilted-ring model with varying complexities. TiRiFiC can be used to model a large number (20+) of parameters which are set in a configuration file (.def) for its execution. However, manually editing these parameters in a text editor is uncomfortable. In this work, we present TiRiFiG, Tilted Ring Fitting GUI, which is the graphical user interface that provides an easy way for parameter inputs to be modified in an interactive manner.
- Full Text:
- Date Issued: 2019
- Authors: Twum, Samuel Nyarko
- Date: 2019
- Subjects: Tilted Ring Fitting GUI , Astronomy -- Observations , Galaxies -- Observations , Galaxies -- Measurement , Galaxies -- Measurement -- Data processing , Kinematics
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/76409 , vital:30558
- Description: Galaxy kinematics is of crucial importance to understanding the structure, formation and evolution of galaxies. The studies of mass distributions giving rise to the missing mass problem, first raised by Zwicky (1933), give us an insight into dark matter distributions which are tightly linked to cosmology. Neutral hydrogen (H i) has been widely used as a tracer in the kinematic studies of galaxies. The Square Kilometre Array (SKA) and its precursors will produce large Hi datasets which will require kinematic modelling tools to extract kinematic parameters such as rotation curves. TiRiFiC (Józsa et al., 2007) is an example of such a tool for 3D kinematic modelling of resolved spectroscopic observations of rotating disks in terms of the tilted-ring model with varying complexities. TiRiFiC can be used to model a large number (20+) of parameters which are set in a configuration file (.def) for its execution. However, manually editing these parameters in a text editor is uncomfortable. In this work, we present TiRiFiG, Tilted Ring Fitting GUI, which is the graphical user interface that provides an easy way for parameter inputs to be modified in an interactive manner.
- Full Text:
- Date Issued: 2019
To explore the Reconstruction Development Programme housing system in South Africa and its full potential relating to the system itself, the design, government’s role and the challenges encountered in its implementation: The Case of Buffalo City Metropolitan Municipality, Eastern Cape
- Authors: Mvunge, Nathunathi Mvunge
- Date: 2019
- Subjects: Housing -- South Africa -- Eastern Cape Human services -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MPA
- Identifier: http://hdl.handle.net/10353/13782 , vital:39711
- Description: The issue of housing in South Africa presents a challenge confronting many citizens. As such, this dissertation seeks to identify the challenges faced by the Buffalo City Metropolitan Municipality in its implementation of the RDP Housing Scheme, to assess how the housing challenges in the BCMM differ from those in other municipalities, to identify the measures taken by the Buffalo City Metropolitan Municipality to address the challenges encountered in the implementation of the RDP Housing Scheme and to give possible recommendations that address the challenges encountered in the implementation of the RDP Housing Scheme in BCMM. The study makes use of qualitative research in the form of in-depth interviews, focus group discussions, observations and relevant secondary literature to collect data from the Buffalo City Metropolitan Municipality and from citizens residing in Amalinda and Scenery Park RDP houses. The findings of the study show that the majority of the occupants of RDP houses in both Amalinda and Scenery Park are not satisfied with the quality of the houses mainly in terms of their sizes and space. The government has limited resources and is not able to provide enough good quality houses to the applicant’s needs. In addition, the study reveals that there are bureaucratic (red tape) delays in the implementation of the RDP and that the government does not work together with or consult with the beneficiaries of the RDP Housing scheme sufficiently. The study was anchored in the Neo-institutional and the growth pole theory. As to recommendations, the study has recommended that the government address the still extant barriers intiated by the apartheid government, by allowing public participation in the implementation of the RDP housing scheme and ensuring that effective screening measures be used to eligible RDP housing occupants.
- Full Text:
- Date Issued: 2019
- Authors: Mvunge, Nathunathi Mvunge
- Date: 2019
- Subjects: Housing -- South Africa -- Eastern Cape Human services -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MPA
- Identifier: http://hdl.handle.net/10353/13782 , vital:39711
- Description: The issue of housing in South Africa presents a challenge confronting many citizens. As such, this dissertation seeks to identify the challenges faced by the Buffalo City Metropolitan Municipality in its implementation of the RDP Housing Scheme, to assess how the housing challenges in the BCMM differ from those in other municipalities, to identify the measures taken by the Buffalo City Metropolitan Municipality to address the challenges encountered in the implementation of the RDP Housing Scheme and to give possible recommendations that address the challenges encountered in the implementation of the RDP Housing Scheme in BCMM. The study makes use of qualitative research in the form of in-depth interviews, focus group discussions, observations and relevant secondary literature to collect data from the Buffalo City Metropolitan Municipality and from citizens residing in Amalinda and Scenery Park RDP houses. The findings of the study show that the majority of the occupants of RDP houses in both Amalinda and Scenery Park are not satisfied with the quality of the houses mainly in terms of their sizes and space. The government has limited resources and is not able to provide enough good quality houses to the applicant’s needs. In addition, the study reveals that there are bureaucratic (red tape) delays in the implementation of the RDP and that the government does not work together with or consult with the beneficiaries of the RDP Housing scheme sufficiently. The study was anchored in the Neo-institutional and the growth pole theory. As to recommendations, the study has recommended that the government address the still extant barriers intiated by the apartheid government, by allowing public participation in the implementation of the RDP housing scheme and ensuring that effective screening measures be used to eligible RDP housing occupants.
- Full Text:
- Date Issued: 2019
Tools to enrich vulnerability assessment and adaptation planning for coastal communities in data-poor regions: application to a case study in Madagascar
- Cochrane, Kevern L, Rakotondrazafy, H, Aswani, Shankar, Chaigneau, Tomas, Downey-Breedt, Nicola, Lemahieu, Anne, Paytan, Adina, Pecl, Gretta T, Plagányi, Éva, Popova, Elizaveta, Van Putten, Ingrid E, Sauer, Warwick H H, Byfield, Val, Gasalla, Maria A, Van Gennip, Simon J, Malherbe, Willem, Rabary, Andriantsilavo, Rabeariso, Ando, Ramaroson, N, Randrianarimanana, V, Scott, Lucy E P, Tsimanaoraty, P M
- Authors: Cochrane, Kevern L , Rakotondrazafy, H , Aswani, Shankar , Chaigneau, Tomas , Downey-Breedt, Nicola , Lemahieu, Anne , Paytan, Adina , Pecl, Gretta T , Plagányi, Éva , Popova, Elizaveta , Van Putten, Ingrid E , Sauer, Warwick H H , Byfield, Val , Gasalla, Maria A , Van Gennip, Simon J , Malherbe, Willem , Rabary, Andriantsilavo , Rabeariso, Ando , Ramaroson, N , Randrianarimanana, V , Scott, Lucy E P , Tsimanaoraty, P M
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/145347 , vital:38430 , DOI: 10.3389/fmars.2018.00505
- Description: Here we describe an interdisciplinary and multi-country initiative to develop rapid, participatory methods to assess the vulnerability of coastal communities and facilitate adaptation to climate change in data-poor regions. The methods were applied in Madagascar as a case study. The initiative centered on an exploratory research exercise in two communities in the south-west of Madagascar, a workshop held in Antananarivo in June 2016, combined with a component on communicating ocean science and climate change to stakeholders. It utilized innovative and rapid approaches to combine global and local skills and information on adaptation and resilience building, taking cognizance of national policies, and was based on the principles of a holistic, integrated and participatory approach. This paper summarizes the activities undertaken and assesses how effective they were in achieving the project goals, as well as presenting examples of the outputs obtained.
- Full Text:
- Date Issued: 2019
- Authors: Cochrane, Kevern L , Rakotondrazafy, H , Aswani, Shankar , Chaigneau, Tomas , Downey-Breedt, Nicola , Lemahieu, Anne , Paytan, Adina , Pecl, Gretta T , Plagányi, Éva , Popova, Elizaveta , Van Putten, Ingrid E , Sauer, Warwick H H , Byfield, Val , Gasalla, Maria A , Van Gennip, Simon J , Malherbe, Willem , Rabary, Andriantsilavo , Rabeariso, Ando , Ramaroson, N , Randrianarimanana, V , Scott, Lucy E P , Tsimanaoraty, P M
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/145347 , vital:38430 , DOI: 10.3389/fmars.2018.00505
- Description: Here we describe an interdisciplinary and multi-country initiative to develop rapid, participatory methods to assess the vulnerability of coastal communities and facilitate adaptation to climate change in data-poor regions. The methods were applied in Madagascar as a case study. The initiative centered on an exploratory research exercise in two communities in the south-west of Madagascar, a workshop held in Antananarivo in June 2016, combined with a component on communicating ocean science and climate change to stakeholders. It utilized innovative and rapid approaches to combine global and local skills and information on adaptation and resilience building, taking cognizance of national policies, and was based on the principles of a holistic, integrated and participatory approach. This paper summarizes the activities undertaken and assesses how effective they were in achieving the project goals, as well as presenting examples of the outputs obtained.
- Full Text:
- Date Issued: 2019
Top-soil water retention in organic and conventional farming systems in South Africa’s Southern Cape
- Authors: Eckert, Catherine Jessica
- Date: 2019
- Subjects: Water harvesting , Soil moisture conservation Organic farming Sustainable agriculture
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/39885 , vital:35500
- Description: With the world’s growing population and limited natural resources, there is a need to produce more food using less inputs. A major limiting factor to meeting the agricultural production needs of the growing population is fresh water. Water is a critical resource in agriculture and may be more of a limiting factor than other crop growth requirements in some areas. Furthermore, water availability is being impacted by climate change and competition from other industries. Methods of improving crop water use efficiency through conservation of water and the enhancement of crop growth need to be employed to meet the growing demand sustainably. The purpose of the research was to assess the differences in soil water status between organically farmed crops with a grass mulch and conventionally farmed crops without mulch, with a view to making more efficient use of the water resource. This research was conducted at the Mandela long term organic farming systems research trial site at Nelson Mandela University, George campus in the southern Cape, South Africa. It is part of a larger research project (the Mandela Trials) in which various researchers have been involved in different aspects of this trial including agronomy, microbiology and pest and disease control. This research took place over two seasons, namely, 2016-2017 season and 2017-2018 season. The soil water content (SWC) of organic and conventional plots were measured using fixed capacitance probes that recorded continuous data, every half hour, at depths of 10, 30 and 50 cm. A handheld theta probe was also used to measure the SWC in the top 6 cm of the soil at 7 to14 day intervals. The organic treatment had a significantly higher SWC than the conventional treatment over the two seasons in which this research was conducted. In addition, soil carbon was significantly higher in the organic treatment, than the conventional. Organic farming methods preserve and promote an increase in soil organic matter, thus improving the soil structure and increasing the soil’s water holding capacity. From this research, it is concluded that organic farming practices can be used to help conserve SWC, keeping it available to crops for longer and helping farmers make more efficient use of this scarce resource. This is especially relevant for low rainfall areas which are affected by water shortages. The improved SWC availability should be coupled with good agronomic practices to increase productive water losses and the conversion of water to yields, thus increasing water use efficiency. In addition, adding organic matter to the soil will improve resilience of the soil and help sequester carbon and thus help in mitigating climate change.
- Full Text:
- Date Issued: 2019
Top-soil water retention in organic and conventional farming systems in South Africa’s Southern Cape
- Authors: Eckert, Catherine Jessica
- Date: 2019
- Subjects: Water harvesting , Soil moisture conservation Organic farming Sustainable agriculture
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/39885 , vital:35500
- Description: With the world’s growing population and limited natural resources, there is a need to produce more food using less inputs. A major limiting factor to meeting the agricultural production needs of the growing population is fresh water. Water is a critical resource in agriculture and may be more of a limiting factor than other crop growth requirements in some areas. Furthermore, water availability is being impacted by climate change and competition from other industries. Methods of improving crop water use efficiency through conservation of water and the enhancement of crop growth need to be employed to meet the growing demand sustainably. The purpose of the research was to assess the differences in soil water status between organically farmed crops with a grass mulch and conventionally farmed crops without mulch, with a view to making more efficient use of the water resource. This research was conducted at the Mandela long term organic farming systems research trial site at Nelson Mandela University, George campus in the southern Cape, South Africa. It is part of a larger research project (the Mandela Trials) in which various researchers have been involved in different aspects of this trial including agronomy, microbiology and pest and disease control. This research took place over two seasons, namely, 2016-2017 season and 2017-2018 season. The soil water content (SWC) of organic and conventional plots were measured using fixed capacitance probes that recorded continuous data, every half hour, at depths of 10, 30 and 50 cm. A handheld theta probe was also used to measure the SWC in the top 6 cm of the soil at 7 to14 day intervals. The organic treatment had a significantly higher SWC than the conventional treatment over the two seasons in which this research was conducted. In addition, soil carbon was significantly higher in the organic treatment, than the conventional. Organic farming methods preserve and promote an increase in soil organic matter, thus improving the soil structure and increasing the soil’s water holding capacity. From this research, it is concluded that organic farming practices can be used to help conserve SWC, keeping it available to crops for longer and helping farmers make more efficient use of this scarce resource. This is especially relevant for low rainfall areas which are affected by water shortages. The improved SWC availability should be coupled with good agronomic practices to increase productive water losses and the conversion of water to yields, thus increasing water use efficiency. In addition, adding organic matter to the soil will improve resilience of the soil and help sequester carbon and thus help in mitigating climate change.
- Full Text:
- Date Issued: 2019
Toward universal sustainability: strategies and guidelines
- Authors: Robertson, Struan Ross
- Date: 2019
- Subjects: Sustainability , Sustainable development , Economic development , Social planning
- Language: English
- Type: text , Thesis , Masters , MEcon
- Identifier: http://hdl.handle.net/10962/71591 , vital:29922
- Description: This research considers the notion of universal sustainability, which involves the three well-known pillars of sustainable development, namely, economic development, social development, and environmental sustainability. Critical to achieving this unity of purpose in the aligning of economic and social aspirations with the limits of the natural environment is the enhancing of human capability and the development of political institutions capable of representing the interests of all people by leveraging resources responsibly. Universal sustainability differs from the concept of sustainable development in that the emphasis is cast not on merely achieving economic development despite the challenges presented by social and environmental concerns, but on seeking to understand what a better society might look like that integrates outcomes in-line with these three factors. Universal sustainability is about re-thinking the purpose of material progress to realign this with the need for social cohesion and to reposition human values and expectations safely within ecological boundaries. In other words, strategies and guidelines that promote the realisation of universal sustainability would recommend a society that values economic and technological progress with equal measure to social development and environmental sustainability, as well as all the other factors that promote human wellbeing. Consequently, this research also considers the inter-linkages that are found between economic development (i.e. technological advancement) and social (i.e. normative progress) and societal (i.e. long-term institutional differentiation) development with respect to labour markets, the formation of skills, the scope of welfare regimes and hence, the trajectory of the social reproduction of society. The prospects of environmental sustainability, like that of societal development, are found to be influenced by the values that a society holds and the ability of economic and social factors to adapt in response to the environmental challenges that face societies in socially workable ways. This research concerns the great quest for meaning and purpose that humans have undertaken throughout history, and asks how human wellbeing – in its best, most expansive sense, can be improved and how societies can advance and prosper going forward while keeping the avenue of individual self-actualisation open as a possibility in the everyday lives of citizens? In achieving this end, this research looks at what economic development strategies suggest as tenable against these aspirations. Furthermore, this research looks at the experience of advanced democratic societies to better conceive of how material progress, social cohesion via education and welfare, and environmental sustainability can be attained. The selection of these countries ensures understanding for the kind of political arrangements that safeguard human wellbeing and give voice to freedom, material opportunities, and civic responsibilities. Critical to both these assessments is defining the mechanics that underlie the processes that achieve material and moral progress in human societies. The main goal of this research is to recommend strategies and guidelines for developing countries like South Africa that wish to develop and thrive. Therefore, this research presents an assessment framework for understanding both universal sustainability and how to achieve it. This research concludes that mindfulness about the natural environment and the services it supplies, as well as mindfulness about what drives economic development and what supports the conditions for human flourishing, are necessary for universal sustainability strategies and guidelines to work. Indeed, the ideologies that societies subscribe to and the values they hold are important 84 to creating the right conditions for economic tools to work to advance economic development, material improvement, socio-environmental justice, and ultimately for achieving universal sustainability. But central to both economic and environmental futures is an understanding that at the heart of the matter is a concern for apprehending what drives human behaviour and aspiration, and what creates social cohesion.
- Full Text:
- Date Issued: 2019
- Authors: Robertson, Struan Ross
- Date: 2019
- Subjects: Sustainability , Sustainable development , Economic development , Social planning
- Language: English
- Type: text , Thesis , Masters , MEcon
- Identifier: http://hdl.handle.net/10962/71591 , vital:29922
- Description: This research considers the notion of universal sustainability, which involves the three well-known pillars of sustainable development, namely, economic development, social development, and environmental sustainability. Critical to achieving this unity of purpose in the aligning of economic and social aspirations with the limits of the natural environment is the enhancing of human capability and the development of political institutions capable of representing the interests of all people by leveraging resources responsibly. Universal sustainability differs from the concept of sustainable development in that the emphasis is cast not on merely achieving economic development despite the challenges presented by social and environmental concerns, but on seeking to understand what a better society might look like that integrates outcomes in-line with these three factors. Universal sustainability is about re-thinking the purpose of material progress to realign this with the need for social cohesion and to reposition human values and expectations safely within ecological boundaries. In other words, strategies and guidelines that promote the realisation of universal sustainability would recommend a society that values economic and technological progress with equal measure to social development and environmental sustainability, as well as all the other factors that promote human wellbeing. Consequently, this research also considers the inter-linkages that are found between economic development (i.e. technological advancement) and social (i.e. normative progress) and societal (i.e. long-term institutional differentiation) development with respect to labour markets, the formation of skills, the scope of welfare regimes and hence, the trajectory of the social reproduction of society. The prospects of environmental sustainability, like that of societal development, are found to be influenced by the values that a society holds and the ability of economic and social factors to adapt in response to the environmental challenges that face societies in socially workable ways. This research concerns the great quest for meaning and purpose that humans have undertaken throughout history, and asks how human wellbeing – in its best, most expansive sense, can be improved and how societies can advance and prosper going forward while keeping the avenue of individual self-actualisation open as a possibility in the everyday lives of citizens? In achieving this end, this research looks at what economic development strategies suggest as tenable against these aspirations. Furthermore, this research looks at the experience of advanced democratic societies to better conceive of how material progress, social cohesion via education and welfare, and environmental sustainability can be attained. The selection of these countries ensures understanding for the kind of political arrangements that safeguard human wellbeing and give voice to freedom, material opportunities, and civic responsibilities. Critical to both these assessments is defining the mechanics that underlie the processes that achieve material and moral progress in human societies. The main goal of this research is to recommend strategies and guidelines for developing countries like South Africa that wish to develop and thrive. Therefore, this research presents an assessment framework for understanding both universal sustainability and how to achieve it. This research concludes that mindfulness about the natural environment and the services it supplies, as well as mindfulness about what drives economic development and what supports the conditions for human flourishing, are necessary for universal sustainability strategies and guidelines to work. Indeed, the ideologies that societies subscribe to and the values they hold are important 84 to creating the right conditions for economic tools to work to advance economic development, material improvement, socio-environmental justice, and ultimately for achieving universal sustainability. But central to both economic and environmental futures is an understanding that at the heart of the matter is a concern for apprehending what drives human behaviour and aspiration, and what creates social cohesion.
- Full Text:
- Date Issued: 2019
Towards a biological profile for South African perinatal remains: osteological and genetic perspectives
- Authors: Thornton, Roxanne
- Date: 2019
- Subjects: Identification , Forensic osteology , Methylation , RNA , Autopsy
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/68102 , vital:29198 , DOI 10.21504/10962/68102
- Description: Forensic identification of abandoned and suspected infanticide cases admitted to the South African Forensic Pathology Services is often impossible due to decomposition of the remains. In these cases, investigation of suspected criminal activity is almost never pursued. Ancillary tests in the form of anthropological and molecular analyses can assist with the forensic identification of perinatal remains. To provide fundamental information about bone development of perinatal skeleton, osteological and genetic techniques focusing on the pars basilaris, pars lateralis, sternal rib and left femur were used. Samples were obtained from unidentified and unclaimed remains originating from the Johannesburg Forensic Pathology Service (JFPS). To provide a biological age to individuals in the collection, dental aging was used to categorize remains for comparisons with anthropological and molecular data. A molecular protocol was designed to sex individuals using the X-linked G6PD and Y-linked SRY genes. Bone development was studied using osteometric and morphological data of dry bone remains coupled with bone mineral density analysis (Micro-CT). The methylation levels of CpG rich sites within the promoter region of selected bone-associated genes were incorporated to examine silencing of genes during development. Osteological results support the use of the pars basilaris, pars lateralis and femur for age-at-death estimations as well as provide the foundation for dry bone aging criteria for South African individuals. Data compared with established skeletal aging standards indicated developmental differences between populations. Through the use of animal models and the perinatal sternal rib tissue, insights and precautions into the use of post mortem bone derived RNA for forensic applications is communicated. The methylation status of CpG rich sites within the promoter regions support the hypothesis for interdependent machinery involving selected genes during early bone development. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2019
- Full Text:
- Date Issued: 2019
- Authors: Thornton, Roxanne
- Date: 2019
- Subjects: Identification , Forensic osteology , Methylation , RNA , Autopsy
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/68102 , vital:29198 , DOI 10.21504/10962/68102
- Description: Forensic identification of abandoned and suspected infanticide cases admitted to the South African Forensic Pathology Services is often impossible due to decomposition of the remains. In these cases, investigation of suspected criminal activity is almost never pursued. Ancillary tests in the form of anthropological and molecular analyses can assist with the forensic identification of perinatal remains. To provide fundamental information about bone development of perinatal skeleton, osteological and genetic techniques focusing on the pars basilaris, pars lateralis, sternal rib and left femur were used. Samples were obtained from unidentified and unclaimed remains originating from the Johannesburg Forensic Pathology Service (JFPS). To provide a biological age to individuals in the collection, dental aging was used to categorize remains for comparisons with anthropological and molecular data. A molecular protocol was designed to sex individuals using the X-linked G6PD and Y-linked SRY genes. Bone development was studied using osteometric and morphological data of dry bone remains coupled with bone mineral density analysis (Micro-CT). The methylation levels of CpG rich sites within the promoter region of selected bone-associated genes were incorporated to examine silencing of genes during development. Osteological results support the use of the pars basilaris, pars lateralis and femur for age-at-death estimations as well as provide the foundation for dry bone aging criteria for South African individuals. Data compared with established skeletal aging standards indicated developmental differences between populations. Through the use of animal models and the perinatal sternal rib tissue, insights and precautions into the use of post mortem bone derived RNA for forensic applications is communicated. The methylation status of CpG rich sites within the promoter regions support the hypothesis for interdependent machinery involving selected genes during early bone development. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2019
- Full Text:
- Date Issued: 2019
Towards a norm of compliance in recreational fisheries
- Authors: Bova, Christopher S
- Date: 2019
- Subjects: Fishing -- Management -- South Africa , Fishery law and legislation -- South Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/95909 , vital:31213
- Description: The activity of fishing can be traced back to prehistoric times. However, only in the last century has there been a focus on the management of fisheries. Fishery regulations are tools used by resource managers with the aim of protecting the long-term sustainability of fishery resources. Although there is an overwhelming amount of evidence demonstrating the decline of fisheries, non-compliance with these regulations by fishers continues to manifest, which can exacerbate the negative ecological impacts of fisheries. Popular methods towards the measurement of noncompliance in fisheries derived from previous human dimensions literature may be flawed. Theories on improving compliance behaviour have typically relied on theory, which has at times proved paradoxical. Addressing the issues of non-compliance within a fishery of interest requires measuring the levels of non-compliance within the fishery and determining the relevant sociopsychological drivers behind the non-compliant behaviour. The data collection methods used during these assessments are limited in human dimensions research and are often case and context specific, requiring researchers to identify which approach is most practical for the specific fishery of interest. By identifying relevant behavioural drivers of non-compliance, a more effective approach aimed at improving compliance can be tailored. The recreational marine-based shore fishery (MBSF) in South Africa is not impervious to noncomplaint behaviour. In fact, it has been estimated to have relatively high rates of non-compliance. This high level of non-compliance makes the South African MBSF a unique and optimal context in which to undertake research that aims to formulate a framework towards compliance assessments and that develops a suitable approach for improving compliance rates. Using surveys to obtain compliance data can provide a range of details about violators, however they are susceptible to social desirability bias (SDB). Choosing the best method for controlling SDB required an assessment of existing methods for doing so. In this first part of the study, only fishers who were covertly observed breaking the rules were surveyed, using one of three methods for reducing SDB, to ground-truth the responses. Ground-truthing was done to determine which method would be most effective for a large-scale study within the same fishery. Of the methods used, which include the direct questioning method (DQM), the random response technique (RRT) and the ballot box method (BBM), all contained some level of SDB. However, the BBM provided a significantly higher level of response accuracy (79.6% ± 11.9) than the DQM (46.5% ± 14.9) and the RRT (44.3% ± 12.5). Random-stratified roving creel compliance surveys that employed the BBM were then undertaken at various locations along South Africa’s coastline to estimate current rates of non-compliance, and the face-to-face results were compared to results from an identical online survey to determine the suitability of online surveys as a replacement. The results indicated that online surveys only represent a subgroup of the fisher population within the MBSF, suggesting that face-to-face survey methods are required to obtain a more comprehensive sample and a more robust estimate of noncompliance. The results, based on 453 face-to-face surveys, showed a high level of overall self-reported noncompliance (48.3%) within the fishery. Responses to Likert scale survey questions on various aspects of the fishery, including angler motivations for fishing, were then modelled to test the relationship between the anglers’ responses and their compliance behaviour. In the South African MBSF context, the most significant behavioural drivers behind non-compliance related to normative concepts. Specifically, the poor perceptions of management and value-based legitimacy as well as low levels of moral obligation to adhere to the regulations appeared to contribute most to the observed non-compliant behaviour. Angler motivations for fishing also played a significant role in determining the compliance behaviour of anglers, with those fishing for food being more likely to violate regulations. In most countries, regardless of economic context, interventions to improve recreational fishery compliance have been developed around the instrumental concept. However, these findings suggest that for recreational fisheries, managers would do well to evaluate the impact of normative concepts on compliance and to design interventions aimed at addressing these. In the case of the South African MBSF, interventions that address angler perceptions of legitimacy and aim to correct misperceptions about social norms of compliance may provide a more practical and cost- effective method for improving poor compliance behaviour.
- Full Text:
- Date Issued: 2019
- Authors: Bova, Christopher S
- Date: 2019
- Subjects: Fishing -- Management -- South Africa , Fishery law and legislation -- South Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/95909 , vital:31213
- Description: The activity of fishing can be traced back to prehistoric times. However, only in the last century has there been a focus on the management of fisheries. Fishery regulations are tools used by resource managers with the aim of protecting the long-term sustainability of fishery resources. Although there is an overwhelming amount of evidence demonstrating the decline of fisheries, non-compliance with these regulations by fishers continues to manifest, which can exacerbate the negative ecological impacts of fisheries. Popular methods towards the measurement of noncompliance in fisheries derived from previous human dimensions literature may be flawed. Theories on improving compliance behaviour have typically relied on theory, which has at times proved paradoxical. Addressing the issues of non-compliance within a fishery of interest requires measuring the levels of non-compliance within the fishery and determining the relevant sociopsychological drivers behind the non-compliant behaviour. The data collection methods used during these assessments are limited in human dimensions research and are often case and context specific, requiring researchers to identify which approach is most practical for the specific fishery of interest. By identifying relevant behavioural drivers of non-compliance, a more effective approach aimed at improving compliance can be tailored. The recreational marine-based shore fishery (MBSF) in South Africa is not impervious to noncomplaint behaviour. In fact, it has been estimated to have relatively high rates of non-compliance. This high level of non-compliance makes the South African MBSF a unique and optimal context in which to undertake research that aims to formulate a framework towards compliance assessments and that develops a suitable approach for improving compliance rates. Using surveys to obtain compliance data can provide a range of details about violators, however they are susceptible to social desirability bias (SDB). Choosing the best method for controlling SDB required an assessment of existing methods for doing so. In this first part of the study, only fishers who were covertly observed breaking the rules were surveyed, using one of three methods for reducing SDB, to ground-truth the responses. Ground-truthing was done to determine which method would be most effective for a large-scale study within the same fishery. Of the methods used, which include the direct questioning method (DQM), the random response technique (RRT) and the ballot box method (BBM), all contained some level of SDB. However, the BBM provided a significantly higher level of response accuracy (79.6% ± 11.9) than the DQM (46.5% ± 14.9) and the RRT (44.3% ± 12.5). Random-stratified roving creel compliance surveys that employed the BBM were then undertaken at various locations along South Africa’s coastline to estimate current rates of non-compliance, and the face-to-face results were compared to results from an identical online survey to determine the suitability of online surveys as a replacement. The results indicated that online surveys only represent a subgroup of the fisher population within the MBSF, suggesting that face-to-face survey methods are required to obtain a more comprehensive sample and a more robust estimate of noncompliance. The results, based on 453 face-to-face surveys, showed a high level of overall self-reported noncompliance (48.3%) within the fishery. Responses to Likert scale survey questions on various aspects of the fishery, including angler motivations for fishing, were then modelled to test the relationship between the anglers’ responses and their compliance behaviour. In the South African MBSF context, the most significant behavioural drivers behind non-compliance related to normative concepts. Specifically, the poor perceptions of management and value-based legitimacy as well as low levels of moral obligation to adhere to the regulations appeared to contribute most to the observed non-compliant behaviour. Angler motivations for fishing also played a significant role in determining the compliance behaviour of anglers, with those fishing for food being more likely to violate regulations. In most countries, regardless of economic context, interventions to improve recreational fishery compliance have been developed around the instrumental concept. However, these findings suggest that for recreational fisheries, managers would do well to evaluate the impact of normative concepts on compliance and to design interventions aimed at addressing these. In the case of the South African MBSF, interventions that address angler perceptions of legitimacy and aim to correct misperceptions about social norms of compliance may provide a more practical and cost- effective method for improving poor compliance behaviour.
- Full Text:
- Date Issued: 2019
Towards defining the tipping point of tolerance to CO2-induced ocean acidification for the growth, development and metabolism of larval dusky kob Argyrosomus japonicus (Pisces: Sciaenidae)
- Authors: Mpopetsi, Pule Peter
- Date: 2019
- Subjects: Argyrosomus japonicus , Argyrosomus , Argyrosomus japonicus -- Larvae , Argyrosomus -- Larvae -- Effect of water acidification on , Argyrosomus japonicus -- Larvae -- Nutrition , Argyrosomus -- Larvae -- Nutrition , Ocean acidification
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/71602 , vital:29924
- Description: Increased CO2 production and the consequent ocean acidification (OA) have been identified as one of the greatest threats to both calcifying and non-calcifying marine organisms. Traditionally, marine fishes, as non-calcifying organisms, were considered to have a higher tolerance to near-future OA conditions owing to their well-developed ion regulatory mechanisms. However, recent studies provide evidence to suggest that they may not be as resilient to near-future OA conditions as previously thought. In addition, earlier life stages of marine fishes are thought to be less tolerant than juveniles and adults of the same species as they lack well-developed ion regulatory mechanisms for maintaining homeostasis. This study follows up on previous studies examining the effects of near-future OA on larval Argyrosomus japonicus, an estuarine-dependent marine fish species, in order to identify the tipping point of tolerance for the larvae of this species. These previous studies showed that elevated pCO2, predicted for the year 2100, had negative effects on growth, development and metabolism and ultimately, survival of larval A. japonicus from post-flexion stage. Larval A. japonicus in the present study were reared from egg up to 22 DAH (days after hatching) under three treatments. The three treatments, (pCO2 353 μatm; pH 8.03), (pCO2 451 μatm; pH 7.93) and (pCO2 602 μatm; pH 7.83) corresponded to levels predicted to occur in year 2050, 2068 and 2090 respectively under the Intergovernmental Panel on Climate Change (IPCC) Representative Concentration Pathways (IPCC RCP) 8.5 model. Size-at-hatch, growth, development and metabolic responses (standard and active metabolic rates and metabolic scope) were assessed and compared between the three treatments throughout the rearing period. Five earlier larval life stages (hatchling – flexion/post-flexion) were identified by the end of the experiment. There were no significant differences in size-at-hatch (P > 0.05), development or the active metabolic (P > 0.05) or metabolic scope (P > 0.05) of fish in the three treatments throughout the study. However, the standard metabolic rate was significantly higher in the year 2068 treatment but only at the flexion/post-flexion stage which could be attributed to differences in developmental rates (including the development of the gills) between the 2068 and the other two treatments. Overall, the metabolic scope was narrowest in the 2090 treatment, but varied according to life stage. Although not significantly different, metabolic scope in the 2090 treatment was noticeably lower at the flexion stage compared to the other two treatments, and the development appeared slower, suggesting that this could be the stage most prone to OA. The study concluded that, in isolation, OA levels predicted to occur between 2050 and 2090 will not negatively affect size-at-hatch, growth, development, and metabolic responses of larval A. japonicus up to 22 DAH (flexion/post-flexion stage). Taken together with the previous studies of the same species, the tipping point of tolerance (where negative impacts will begin) in larvae of the species appears to be between the years 2090 and 2100.
- Full Text:
- Date Issued: 2019
- Authors: Mpopetsi, Pule Peter
- Date: 2019
- Subjects: Argyrosomus japonicus , Argyrosomus , Argyrosomus japonicus -- Larvae , Argyrosomus -- Larvae -- Effect of water acidification on , Argyrosomus japonicus -- Larvae -- Nutrition , Argyrosomus -- Larvae -- Nutrition , Ocean acidification
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/71602 , vital:29924
- Description: Increased CO2 production and the consequent ocean acidification (OA) have been identified as one of the greatest threats to both calcifying and non-calcifying marine organisms. Traditionally, marine fishes, as non-calcifying organisms, were considered to have a higher tolerance to near-future OA conditions owing to their well-developed ion regulatory mechanisms. However, recent studies provide evidence to suggest that they may not be as resilient to near-future OA conditions as previously thought. In addition, earlier life stages of marine fishes are thought to be less tolerant than juveniles and adults of the same species as they lack well-developed ion regulatory mechanisms for maintaining homeostasis. This study follows up on previous studies examining the effects of near-future OA on larval Argyrosomus japonicus, an estuarine-dependent marine fish species, in order to identify the tipping point of tolerance for the larvae of this species. These previous studies showed that elevated pCO2, predicted for the year 2100, had negative effects on growth, development and metabolism and ultimately, survival of larval A. japonicus from post-flexion stage. Larval A. japonicus in the present study were reared from egg up to 22 DAH (days after hatching) under three treatments. The three treatments, (pCO2 353 μatm; pH 8.03), (pCO2 451 μatm; pH 7.93) and (pCO2 602 μatm; pH 7.83) corresponded to levels predicted to occur in year 2050, 2068 and 2090 respectively under the Intergovernmental Panel on Climate Change (IPCC) Representative Concentration Pathways (IPCC RCP) 8.5 model. Size-at-hatch, growth, development and metabolic responses (standard and active metabolic rates and metabolic scope) were assessed and compared between the three treatments throughout the rearing period. Five earlier larval life stages (hatchling – flexion/post-flexion) were identified by the end of the experiment. There were no significant differences in size-at-hatch (P > 0.05), development or the active metabolic (P > 0.05) or metabolic scope (P > 0.05) of fish in the three treatments throughout the study. However, the standard metabolic rate was significantly higher in the year 2068 treatment but only at the flexion/post-flexion stage which could be attributed to differences in developmental rates (including the development of the gills) between the 2068 and the other two treatments. Overall, the metabolic scope was narrowest in the 2090 treatment, but varied according to life stage. Although not significantly different, metabolic scope in the 2090 treatment was noticeably lower at the flexion stage compared to the other two treatments, and the development appeared slower, suggesting that this could be the stage most prone to OA. The study concluded that, in isolation, OA levels predicted to occur between 2050 and 2090 will not negatively affect size-at-hatch, growth, development, and metabolic responses of larval A. japonicus up to 22 DAH (flexion/post-flexion stage). Taken together with the previous studies of the same species, the tipping point of tolerance (where negative impacts will begin) in larvae of the species appears to be between the years 2090 and 2100.
- Full Text:
- Date Issued: 2019
Towards understanding and mitigating attacks leveraging zero-day exploits
- Authors: Smit, Liam
- Date: 2019
- Subjects: Computer crimes -- Prevention , Data protection , Hacking , Computer security , Computer networks -- Security measures , Computers -- Access control , Malware (Computer software)
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/115718 , vital:34218
- Description: Zero-day vulnerabilities are unknown and therefore not addressed with the result that they can be exploited by attackers to gain unauthorised system access. In order to understand and mitigate against attacks leveraging zero-days or unknown techniques, it is necessary to study the vulnerabilities, exploits and attacks that make use of them. In recent years there have been a number of leaks publishing such attacks using various methods to exploit vulnerabilities. This research seeks to understand what types of vulnerabilities exist, why and how these are exploited, and how to defend against such attacks by either mitigating the vulnerabilities or the method / process of exploiting them. By moving beyond merely remedying the vulnerabilities to defences that are able to prevent or detect the actions taken by attackers, the security of the information system will be better positioned to deal with future unknown threats. An interesting finding is how attackers exploit moving beyond the observable bounds to circumvent security defences, for example, compromising syslog servers, or going down to lower system rings to gain access. However, defenders can counter this by employing defences that are external to the system preventing attackers from disabling them or removing collected evidence after gaining system access. Attackers are able to defeat air-gaps via the leakage of electromagnetic radiation as well as misdirect attribution by planting false artefacts for forensic analysis and attacking from third party information systems. They analyse the methods of other attackers to learn new techniques. An example of this is the Umbrage project whereby malware is analysed to decide whether it should be implemented as a proof of concept. Another important finding is that attackers respect defence mechanisms such as: remote syslog (e.g. firewall), core dump files, database auditing, and Tripwire (e.g. SlyHeretic). These defences all have the potential to result in the attacker being discovered. Attackers must either negate the defence mechanism or find unprotected targets. Defenders can use technologies such as encryption to defend against interception and man-in-the-middle attacks. They can also employ honeytokens and honeypots to alarm misdirect, slow down and learn from attackers. By employing various tactics defenders are able to increase their chance of detecting and time to react to attacks, even those exploiting hitherto unknown vulnerabilities. To summarize the information presented in this thesis and to show the practical importance thereof, an examination is presented of the NSA's network intrusion of the SWIFT organisation. It shows that the firewalls were exploited with remote code execution zerodays. This attack has a striking parallel in the approach used in the recent VPNFilter malware. If nothing else, the leaks provide information to other actors on how to attack and what to avoid. However, by studying state actors, we can gain insight into what other actors with fewer resources can do in the future.
- Full Text:
- Date Issued: 2019
- Authors: Smit, Liam
- Date: 2019
- Subjects: Computer crimes -- Prevention , Data protection , Hacking , Computer security , Computer networks -- Security measures , Computers -- Access control , Malware (Computer software)
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/115718 , vital:34218
- Description: Zero-day vulnerabilities are unknown and therefore not addressed with the result that they can be exploited by attackers to gain unauthorised system access. In order to understand and mitigate against attacks leveraging zero-days or unknown techniques, it is necessary to study the vulnerabilities, exploits and attacks that make use of them. In recent years there have been a number of leaks publishing such attacks using various methods to exploit vulnerabilities. This research seeks to understand what types of vulnerabilities exist, why and how these are exploited, and how to defend against such attacks by either mitigating the vulnerabilities or the method / process of exploiting them. By moving beyond merely remedying the vulnerabilities to defences that are able to prevent or detect the actions taken by attackers, the security of the information system will be better positioned to deal with future unknown threats. An interesting finding is how attackers exploit moving beyond the observable bounds to circumvent security defences, for example, compromising syslog servers, or going down to lower system rings to gain access. However, defenders can counter this by employing defences that are external to the system preventing attackers from disabling them or removing collected evidence after gaining system access. Attackers are able to defeat air-gaps via the leakage of electromagnetic radiation as well as misdirect attribution by planting false artefacts for forensic analysis and attacking from third party information systems. They analyse the methods of other attackers to learn new techniques. An example of this is the Umbrage project whereby malware is analysed to decide whether it should be implemented as a proof of concept. Another important finding is that attackers respect defence mechanisms such as: remote syslog (e.g. firewall), core dump files, database auditing, and Tripwire (e.g. SlyHeretic). These defences all have the potential to result in the attacker being discovered. Attackers must either negate the defence mechanism or find unprotected targets. Defenders can use technologies such as encryption to defend against interception and man-in-the-middle attacks. They can also employ honeytokens and honeypots to alarm misdirect, slow down and learn from attackers. By employing various tactics defenders are able to increase their chance of detecting and time to react to attacks, even those exploiting hitherto unknown vulnerabilities. To summarize the information presented in this thesis and to show the practical importance thereof, an examination is presented of the NSA's network intrusion of the SWIFT organisation. It shows that the firewalls were exploited with remote code execution zerodays. This attack has a striking parallel in the approach used in the recent VPNFilter malware. If nothing else, the leaks provide information to other actors on how to attack and what to avoid. However, by studying state actors, we can gain insight into what other actors with fewer resources can do in the future.
- Full Text:
- Date Issued: 2019
Tracking the decline of the world’s largest seabream against policy adjustments
- Kerwath, Sven E, Parker, Denham, Winker, A Henning, Potts, Warren M, Mann, Bruce Q, Wilke, Christopher, Attwood, Colin G
- Authors: Kerwath, Sven E , Parker, Denham , Winker, A Henning , Potts, Warren M , Mann, Bruce Q , Wilke, Christopher , Attwood, Colin G
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/131433 , vital:36571 , https://doi.org/10.3354/meps12853
- Description: For most rare marine species, abundance trends are poorly estimated. This uncertainty often translates into disagreement on management regulations, impeding conservation efforts when they are most urgently required. The world’s largest sea bream, the red steenbras Petrus rupestris, has undergone a substantial and widely acknowledged decline during the 20th century. Standardised probability of encounter over the last 3 decades was used to track red steenbras abundance trajectories in 2 regions, which together represent the species’ distribution. The results predicted a reduction in abundance of 44% in the East region and 96% in the South-West region, from what was already considered to be a collapsed population at the start of the time series. The species is now largely confined to areas in the centre of its historical abundance. Content analysis of a recreational angling magazine revealed a concurrent 50% decrease in reported size between 1984 and 2012. Shore-based observer data (2009-2010) indicate that the impact of recreational fishers on this species far exceeded that of commercial fishers at the time. Regulations in the form of progressively more stringent catch and effort restrictions appear to have been largely ineffective, too lenient, implemented too late or were unsuitable to control fishing mortality for this species. This study highlights 2 fundamental challenges in management of rare marine fish species: (1) providing decision makers with a credible measure of abundance for species whose rarity limits data availability and (2) implementing effective policy changes before the specific measures become ineffective and obsolete.
- Full Text:
- Date Issued: 2019
- Authors: Kerwath, Sven E , Parker, Denham , Winker, A Henning , Potts, Warren M , Mann, Bruce Q , Wilke, Christopher , Attwood, Colin G
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/131433 , vital:36571 , https://doi.org/10.3354/meps12853
- Description: For most rare marine species, abundance trends are poorly estimated. This uncertainty often translates into disagreement on management regulations, impeding conservation efforts when they are most urgently required. The world’s largest sea bream, the red steenbras Petrus rupestris, has undergone a substantial and widely acknowledged decline during the 20th century. Standardised probability of encounter over the last 3 decades was used to track red steenbras abundance trajectories in 2 regions, which together represent the species’ distribution. The results predicted a reduction in abundance of 44% in the East region and 96% in the South-West region, from what was already considered to be a collapsed population at the start of the time series. The species is now largely confined to areas in the centre of its historical abundance. Content analysis of a recreational angling magazine revealed a concurrent 50% decrease in reported size between 1984 and 2012. Shore-based observer data (2009-2010) indicate that the impact of recreational fishers on this species far exceeded that of commercial fishers at the time. Regulations in the form of progressively more stringent catch and effort restrictions appear to have been largely ineffective, too lenient, implemented too late or were unsuitable to control fishing mortality for this species. This study highlights 2 fundamental challenges in management of rare marine fish species: (1) providing decision makers with a credible measure of abundance for species whose rarity limits data availability and (2) implementing effective policy changes before the specific measures become ineffective and obsolete.
- Full Text:
- Date Issued: 2019
Trade union liability for unprotected strike action and violence in furtherance thereof
- Authors: Tshentu, Nolitha
- Date: 2019
- Subjects: Strikes and lockouts -- Law and legislation -- South Africa , Strikes and lockouts -- South Africa Strikes and lockouts Labor unions -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: http://hdl.handle.net/10948/43743 , vital:37040
- Description: The right to strike is a constitutional right and is integral to the process of collective bargaining. Collective bargaining tends to focus on sensitive issues like wages, as well as terms and conditions of employment. Resolving these issues often requires compromise from both parties through the collective bargaining process. However, in the earlier stages of labour law there was no collective bargaining. There was a master and servant relationship, there was no compromise, and it was limited only to the individual contract of hire. As much as a strikes are a constitutional right and are recognised by the law, they don’t seem to happen without violence and destruction of property. There are some views that view violence as being synonymous with strikes in South Africa. The legal framework is very clear and supports the right to strike, and emphasises that any demonstrations and picketing should be peaceful. Section 68(1)(b) of the LRA should be a solution to the violence that comes with unprotected strikes. This section refers to just and equitable compensation, it does not equate to full loss suffered and it also depends on the merits of each case. The ILO’s approach to illegitimate actions linked to strikes should be proportionate to the offence of fault committed. The Constitution saw South Africa making a clean break with the past. The Constitution is focused on ensuring human dignity, the achievement of equality and advancement of human rights and freedoms.1 According to the Constitution the right to assemble and demonstrate must be peaceful. According to Grogan the right is now seen as a necessary adjunct to collective bargaining and is constitutionally entrenched.2 The LRA supports participation in protected strikes. In cases of unprotected strikes allows employers to interdict that particular strike, sue for compensation in cases of damages and losses and also to discipline employees. The Regulations of the Gatherings Act (RGA) was introduced to reconcile the right of assemblers with the state’s interest in maintaining public order. Section 11 of this Act seeks to deter violence and discourages violation of others by ensuring that organisers are held liable. The LRA holds the trade union and its members liable for the damages and violence that is accompanied by unprotected strikes. Section 68(1)(b) seeks just and equitable compensation for damages caused during an unprotected strike. However even though there is recourse for the damages suffered during the protest, unprotected strikes still continue and the violence is still part of the strikes. It is proper to ask if this section is really serving what it was intended. Surely the intention of this section was to deter strikers from embarking on unprotected strikes as the LRA is very clear on the procedure to be followed before a strike action takes place. Another intention of this section is to curb the violence during strikes. This section seems to have fallen on deaf ears.
- Full Text:
- Date Issued: 2019
- Authors: Tshentu, Nolitha
- Date: 2019
- Subjects: Strikes and lockouts -- Law and legislation -- South Africa , Strikes and lockouts -- South Africa Strikes and lockouts Labor unions -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: http://hdl.handle.net/10948/43743 , vital:37040
- Description: The right to strike is a constitutional right and is integral to the process of collective bargaining. Collective bargaining tends to focus on sensitive issues like wages, as well as terms and conditions of employment. Resolving these issues often requires compromise from both parties through the collective bargaining process. However, in the earlier stages of labour law there was no collective bargaining. There was a master and servant relationship, there was no compromise, and it was limited only to the individual contract of hire. As much as a strikes are a constitutional right and are recognised by the law, they don’t seem to happen without violence and destruction of property. There are some views that view violence as being synonymous with strikes in South Africa. The legal framework is very clear and supports the right to strike, and emphasises that any demonstrations and picketing should be peaceful. Section 68(1)(b) of the LRA should be a solution to the violence that comes with unprotected strikes. This section refers to just and equitable compensation, it does not equate to full loss suffered and it also depends on the merits of each case. The ILO’s approach to illegitimate actions linked to strikes should be proportionate to the offence of fault committed. The Constitution saw South Africa making a clean break with the past. The Constitution is focused on ensuring human dignity, the achievement of equality and advancement of human rights and freedoms.1 According to the Constitution the right to assemble and demonstrate must be peaceful. According to Grogan the right is now seen as a necessary adjunct to collective bargaining and is constitutionally entrenched.2 The LRA supports participation in protected strikes. In cases of unprotected strikes allows employers to interdict that particular strike, sue for compensation in cases of damages and losses and also to discipline employees. The Regulations of the Gatherings Act (RGA) was introduced to reconcile the right of assemblers with the state’s interest in maintaining public order. Section 11 of this Act seeks to deter violence and discourages violation of others by ensuring that organisers are held liable. The LRA holds the trade union and its members liable for the damages and violence that is accompanied by unprotected strikes. Section 68(1)(b) seeks just and equitable compensation for damages caused during an unprotected strike. However even though there is recourse for the damages suffered during the protest, unprotected strikes still continue and the violence is still part of the strikes. It is proper to ask if this section is really serving what it was intended. Surely the intention of this section was to deter strikers from embarking on unprotected strikes as the LRA is very clear on the procedure to be followed before a strike action takes place. Another intention of this section is to curb the violence during strikes. This section seems to have fallen on deaf ears.
- Full Text:
- Date Issued: 2019
Training intervention for volunteers supporting victims of intimate partner violence in South Africa
- Authors: Thomas, Samantha
- Date: 2019
- Subjects: Intimate partner violence -- Psychological aspects , Victims of family violence -- Services for -- South Africa , Marital violence , Victims of dating violence , Family violence -- Law and legislation , Non-governmental organizations -- South Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/65079 , vital:28679
- Description: Intimate Partner Violence continues to be a significant social problem in South Africa, requiring a systematised and effective response at multiple levels. The organisation at the centre of this research offers crisis intervention to victims of intimate partner violence, providing basic psychological support, legal information and referrals. The volunteer crisis interventionists are exposed to numerous in-depth accounts of violent and distressing victimisation, making them more vulnerable to vicarious traumatisation. Through this work, their prior assumptions about personal safety, the trustworthiness of other people, and basic justice in the world, are challenged. The challenge to these assumptions increases the likelihood of countertransference victim blaming responses, as it is often easier to hold the client responsible for the tragic event than for the support worker to transform their own assumptions about safety and justice. This victim blaming response is supported by the dominant patriarchal ideology which frequently seeks to maintain the systems of oppression, excusing the perpetrator and placing responsibility on the victim. It was therefore clear that in order to do this work effectively, volunteers needed to be trained to identify their countertransference reactions and emotional responses, as well as undergo a critical re-assessment of their ideas relating to intimate partner violence and victimisation. Using an Intervention Research paradigm, this research designed and developed a training programme based on transformative learning theory, moving away from traditional information models of training to a focus on emotional skills and critical self-insight. The phases of the intervention refined the intervention in order to ensure that the research objectives were met and that the programme could be easily replicated. The evaluation of each phase showed an increased capacity for critical insight, and evidence for a transformative shift in the trainees understanding and approach to intimate partner violence.
- Full Text:
- Date Issued: 2019
Training intervention for volunteers supporting victims of intimate partner violence in South Africa
- Authors: Thomas, Samantha
- Date: 2019
- Subjects: Intimate partner violence -- Psychological aspects , Victims of family violence -- Services for -- South Africa , Marital violence , Victims of dating violence , Family violence -- Law and legislation , Non-governmental organizations -- South Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/65079 , vital:28679
- Description: Intimate Partner Violence continues to be a significant social problem in South Africa, requiring a systematised and effective response at multiple levels. The organisation at the centre of this research offers crisis intervention to victims of intimate partner violence, providing basic psychological support, legal information and referrals. The volunteer crisis interventionists are exposed to numerous in-depth accounts of violent and distressing victimisation, making them more vulnerable to vicarious traumatisation. Through this work, their prior assumptions about personal safety, the trustworthiness of other people, and basic justice in the world, are challenged. The challenge to these assumptions increases the likelihood of countertransference victim blaming responses, as it is often easier to hold the client responsible for the tragic event than for the support worker to transform their own assumptions about safety and justice. This victim blaming response is supported by the dominant patriarchal ideology which frequently seeks to maintain the systems of oppression, excusing the perpetrator and placing responsibility on the victim. It was therefore clear that in order to do this work effectively, volunteers needed to be trained to identify their countertransference reactions and emotional responses, as well as undergo a critical re-assessment of their ideas relating to intimate partner violence and victimisation. Using an Intervention Research paradigm, this research designed and developed a training programme based on transformative learning theory, moving away from traditional information models of training to a focus on emotional skills and critical self-insight. The phases of the intervention refined the intervention in order to ensure that the research objectives were met and that the programme could be easily replicated. The evaluation of each phase showed an increased capacity for critical insight, and evidence for a transformative shift in the trainees understanding and approach to intimate partner violence.
- Full Text:
- Date Issued: 2019
Transitioning into work
- Authors: Rosenberg, Eureta
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/436132 , vital:73229 , ISBN 9780429279362 , https://www.taylorfrancis.com/chapters/edit/10.4324/9780429279362-13/synthesis-elaboration-critical-realist-methodology-green-skills-research-eureta-rosenberg
- Description: Due to the relative newness and contemporary emergence of environmental concerns and sustainable development challenges, policies and forms of work, little is known about the transitioning patterns from education to work. As environmental occupations are found in multiple sectors, and at multiple levels, it is necessary to understand how diversity of disciplinary foundation, historical factors and the nature of the field-based occupation as it is emerging influence transitions into work, especially for highly specialised occupations that are in high demand, such as wildlife vets or wetland ecologists, and in critical occupations that shape sustainable development for whole communities, such as sustainable development employees in municipalities. This chapter utilises a complex notion of learning pathways as neither completely individualistic nor wholly structurally determined, and positions our interest in transitions research within a framing of critical vocationalism that seeks to address not only individual experiences of transitioning, or individual agentive factors, but also structural dynamics and structural processes that can help to ‘ease’ the transitioning process in these critical areas of green skills development.
- Full Text:
- Date Issued: 2019
- Authors: Rosenberg, Eureta
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/436132 , vital:73229 , ISBN 9780429279362 , https://www.taylorfrancis.com/chapters/edit/10.4324/9780429279362-13/synthesis-elaboration-critical-realist-methodology-green-skills-research-eureta-rosenberg
- Description: Due to the relative newness and contemporary emergence of environmental concerns and sustainable development challenges, policies and forms of work, little is known about the transitioning patterns from education to work. As environmental occupations are found in multiple sectors, and at multiple levels, it is necessary to understand how diversity of disciplinary foundation, historical factors and the nature of the field-based occupation as it is emerging influence transitions into work, especially for highly specialised occupations that are in high demand, such as wildlife vets or wetland ecologists, and in critical occupations that shape sustainable development for whole communities, such as sustainable development employees in municipalities. This chapter utilises a complex notion of learning pathways as neither completely individualistic nor wholly structurally determined, and positions our interest in transitions research within a framing of critical vocationalism that seeks to address not only individual experiences of transitioning, or individual agentive factors, but also structural dynamics and structural processes that can help to ‘ease’ the transitioning process in these critical areas of green skills development.
- Full Text:
- Date Issued: 2019
Transitioning into work: A learning and work transitioning process perspective
- Ramsarup, Presha, Lotz-Sisitka, Heila
- Authors: Ramsarup, Presha , Lotz-Sisitka, Heila
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/392944 , vital:68814 , ISBN 9780429279362 , https://doi.org/10.4324/9780429279362
- Description: Due to the relative newness and contemporary emergence of environmental concerns and sustainable development challenges, policies and forms of work, little is known about the transitioning patterns from education to work. As environmental occupations are found in multiple sectors, and at multiple levels, it is necessary to understand how diversity of disciplinary foundation, historical factors and the nature of the field-based occupation as it is emerging influence transitions into work, especially for highly specialised occupations that are in high demand, such as wildlife vets or wetland ecologists, and in critical occupations that shape sustainable development for whole communities, such as sustainable development employees in municipalities. This chapter utilises a complex notion of learning pathways as neither completely individualistic nor wholly structurally determined, and positions our interest in transitions research within a framing of critical vocationalism that seeks to address not only individual experiences of transitioning, or individual agentive factors, but also structural dynamics and structural processes that can help to ‘ease’ the transitioning process in these critical areas of green skills development.
- Full Text:
- Date Issued: 2019
- Authors: Ramsarup, Presha , Lotz-Sisitka, Heila
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/392944 , vital:68814 , ISBN 9780429279362 , https://doi.org/10.4324/9780429279362
- Description: Due to the relative newness and contemporary emergence of environmental concerns and sustainable development challenges, policies and forms of work, little is known about the transitioning patterns from education to work. As environmental occupations are found in multiple sectors, and at multiple levels, it is necessary to understand how diversity of disciplinary foundation, historical factors and the nature of the field-based occupation as it is emerging influence transitions into work, especially for highly specialised occupations that are in high demand, such as wildlife vets or wetland ecologists, and in critical occupations that shape sustainable development for whole communities, such as sustainable development employees in municipalities. This chapter utilises a complex notion of learning pathways as neither completely individualistic nor wholly structurally determined, and positions our interest in transitions research within a framing of critical vocationalism that seeks to address not only individual experiences of transitioning, or individual agentive factors, but also structural dynamics and structural processes that can help to ‘ease’ the transitioning process in these critical areas of green skills development.
- Full Text:
- Date Issued: 2019
Transport infrastructure investment and exports growth in South Africa
- Authors: Gengele , Nosiphelo
- Date: 2019
- Subjects: Transportation -- South Africa Infrastructure (Economics) -- South Africa
- Language: English
- Type: Thesis , Masters , MCom (Transport Economics)
- Identifier: http://hdl.handle.net/10353/13370 , vital:39638
- Description: The transport sector is very important in facilitating trade and travel between and within nations. It is at the core of every country‟s economy. In order for transport to play this critical role, this research suggests that it is important for countries to invest in infrastructure. This study examined the impact of transport infrastructure investment on export growth in South Africa for the period of 1994 to 2017. The standard procedure in interpreting the long-run VECM results was applied. All the variables enter the long-run equation significantly, and the signs and magnitudes also appear reasonable. The long run results suggest that transport infrastructure investment have a positive effect on exports in South Africa. As indicated on the long-run equation, transport infrastructure investment is significant in specification; the positive coefficient of the variable in the regression suggests that an increase in investment in the transport infrastructure will lead to an increase in exports. A vector error correction model was estimated with exports, transport infrastructure investment, real effective exchange rate, world gross domestic product, export prices and consumer price index. The variance decompositions show that exports have a high level of inertia in the first year with most of the variations dependent on past export variations. In the second year, employment contributes significantly to variations in exports. Transport infrastructure investment makes very little contribution. Impulse responses show that a positive shock to infrastructure investments increases exports marginally. The results of the study have revealed a number of policy implications that affect transport infrastructure investment and exports. It is highly recommended that government should improve transport infrastructure for all modes of transport as this will lead to an increase in the level of exports in South Africa. Empirical evidence shows that transport infrastructure investment granger cause exports. Government expenditure in transport infrastructure has been considered s one of the means to enhance economic development and transport sector operates as the crucial engine of the economic growth in both developed and developing countries
- Full Text:
- Date Issued: 2019
- Authors: Gengele , Nosiphelo
- Date: 2019
- Subjects: Transportation -- South Africa Infrastructure (Economics) -- South Africa
- Language: English
- Type: Thesis , Masters , MCom (Transport Economics)
- Identifier: http://hdl.handle.net/10353/13370 , vital:39638
- Description: The transport sector is very important in facilitating trade and travel between and within nations. It is at the core of every country‟s economy. In order for transport to play this critical role, this research suggests that it is important for countries to invest in infrastructure. This study examined the impact of transport infrastructure investment on export growth in South Africa for the period of 1994 to 2017. The standard procedure in interpreting the long-run VECM results was applied. All the variables enter the long-run equation significantly, and the signs and magnitudes also appear reasonable. The long run results suggest that transport infrastructure investment have a positive effect on exports in South Africa. As indicated on the long-run equation, transport infrastructure investment is significant in specification; the positive coefficient of the variable in the regression suggests that an increase in investment in the transport infrastructure will lead to an increase in exports. A vector error correction model was estimated with exports, transport infrastructure investment, real effective exchange rate, world gross domestic product, export prices and consumer price index. The variance decompositions show that exports have a high level of inertia in the first year with most of the variations dependent on past export variations. In the second year, employment contributes significantly to variations in exports. Transport infrastructure investment makes very little contribution. Impulse responses show that a positive shock to infrastructure investments increases exports marginally. The results of the study have revealed a number of policy implications that affect transport infrastructure investment and exports. It is highly recommended that government should improve transport infrastructure for all modes of transport as this will lead to an increase in the level of exports in South Africa. Empirical evidence shows that transport infrastructure investment granger cause exports. Government expenditure in transport infrastructure has been considered s one of the means to enhance economic development and transport sector operates as the crucial engine of the economic growth in both developed and developing countries
- Full Text:
- Date Issued: 2019
Triggering biodegradation of low-density polyethylene films containing biobased additives for ecological applications
- Authors: Gada, Abongile
- Date: 2019
- Subjects: Refuse and refuse disposal , Plastics industry and trade -- Waste disposal Polyethylene Polyurethanes
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/39796 , vital:35460
- Description: The aims of the present study are focused on the investigation of low-density polyethylene (LDPE) films that contain biobased pro-oxidizing additives (CSIR1% and CSIR3% (w/w)) for environmental degradation in different abiotic and biotic conditions in comparison to non-biodegradable commercially available Pick n Pay (PnP) PE grocery bags. In this project, a biobased pro-oxidant additive master batch was prepared in a heat kneader mixer. A mixture of biobased radical reaction initiators and natural polymers were melt processed as a master batch. The biobased pro-oxidant additive master batch CSIR1% and CSIR3% and LDPE components were melt-extruded to form biobased pro-oxidant additive LDPE pellets using a twin screw melt extruder. The pelletized biobased pro-oxidant additive LDPE was blown into a 25 -27 μm thick film using a melt blower machine. The LDPE containing biobased pro-oxidant additive CSIR 1% and 3% test samples and the PnP polyethylene carrier bags were submitted to thermal oxidizing test conditions in a 70°C air ventilated oven and direct sunlight (photo oxidation) for a period of six months (180 days). The thermal and photo-oxidized LDPE film test samples were further subjected to biotic degradation tests in aqueous, soil and compost environments for varying periods of 180 days to 263 days in biodegradation evaluation studies. The oxidation degradation rates of the test samples were monitored and determined by evaluating carbonyl index (COi) using FT-IR spectroscopy; molecular weight determination and distribution of the test materials were analyzed by Gel Permeation Chromatography (GPC); compounds analysis was done by GC-MS; percentage crystallinity (Xc%) was quantified by DSC; thermal stability by TGA and morphological surfaces were examined by SEM analytical techniques. Biodegradation tests simulating marine salt water, burial in soil and compost conditioning methods were used to determine the “potential biodegradability” of the thermally and photo-oxidized test samples after the oxidation period. The oxidation extent and rate of LDPE films containing CSIR3% biobased additives was higher than that of LDPE films containing CSIR1% biobased additives. GPC molecular weight determination and distribution results showed a decrease for all the test samples exposed to oxidation. The molecular weight of LDPE films containing CSIR1% biobased additives decreased from 404K Mw to 111K Mw for sunlight oxidized samples and to 16KMw for the thermally oxidized LDPE samples after 200 days of oxidation exposure. Molecular weight of LDPE films containing CSIR3% biobased additives showed the most reduction from 293K Mw to 22K Mw for sunlight oxidized samples and to 2K Mw for thermally oxidized samples after 100 days of oxidation exposure. DSC analysis showed that crystallinity degree decreased after exposure to thermal and photo-oxidation. TGA results showed a reduction of initial degradation temperature by almost half compared to zero-days untreated CSIR3% samples, with higher degree temperatures observed in samples exposed to thermal oxidation than those exposed to photo-oxidation. GC-MS revealed peaks of carbonyls such as alcohols, aldehydes, ketones, carboxylic and anionic acids, and very short chain alkenes and alkanes. The SEM showed heterogeneous morphological modifications in surfaces of samples even though they were not severe. After 172 days the oxidized LDPE samples containing CSIR3% biobased additives, were investigated for potential biodegradation in aqueous, soil and composting environments. Thermally oxidized and photo-oxidized CSIR3% samples showed a mineralization degree of 10.4% and 10.7% respectively, when oxidized in 181 days aqueous biodegradation, 20% and 7.7% respectively, when oxidized in 233 days of soil burial, and 52.6% and 62% respectively, oxidized in 263 days of compost. The obtained results confirmed the abiotic oxidation step as the initiation step for PE degradation, succeeded by assimilation, by action of microorganisms (ultimate biodegradation), of lower weight molecular compounds of oxidized LDPE samples in aqueous medium, soil and composting conditions to final end products of CO2, H2O and new microbial cell biomass.
- Full Text:
- Date Issued: 2019
- Authors: Gada, Abongile
- Date: 2019
- Subjects: Refuse and refuse disposal , Plastics industry and trade -- Waste disposal Polyethylene Polyurethanes
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/39796 , vital:35460
- Description: The aims of the present study are focused on the investigation of low-density polyethylene (LDPE) films that contain biobased pro-oxidizing additives (CSIR1% and CSIR3% (w/w)) for environmental degradation in different abiotic and biotic conditions in comparison to non-biodegradable commercially available Pick n Pay (PnP) PE grocery bags. In this project, a biobased pro-oxidant additive master batch was prepared in a heat kneader mixer. A mixture of biobased radical reaction initiators and natural polymers were melt processed as a master batch. The biobased pro-oxidant additive master batch CSIR1% and CSIR3% and LDPE components were melt-extruded to form biobased pro-oxidant additive LDPE pellets using a twin screw melt extruder. The pelletized biobased pro-oxidant additive LDPE was blown into a 25 -27 μm thick film using a melt blower machine. The LDPE containing biobased pro-oxidant additive CSIR 1% and 3% test samples and the PnP polyethylene carrier bags were submitted to thermal oxidizing test conditions in a 70°C air ventilated oven and direct sunlight (photo oxidation) for a period of six months (180 days). The thermal and photo-oxidized LDPE film test samples were further subjected to biotic degradation tests in aqueous, soil and compost environments for varying periods of 180 days to 263 days in biodegradation evaluation studies. The oxidation degradation rates of the test samples were monitored and determined by evaluating carbonyl index (COi) using FT-IR spectroscopy; molecular weight determination and distribution of the test materials were analyzed by Gel Permeation Chromatography (GPC); compounds analysis was done by GC-MS; percentage crystallinity (Xc%) was quantified by DSC; thermal stability by TGA and morphological surfaces were examined by SEM analytical techniques. Biodegradation tests simulating marine salt water, burial in soil and compost conditioning methods were used to determine the “potential biodegradability” of the thermally and photo-oxidized test samples after the oxidation period. The oxidation extent and rate of LDPE films containing CSIR3% biobased additives was higher than that of LDPE films containing CSIR1% biobased additives. GPC molecular weight determination and distribution results showed a decrease for all the test samples exposed to oxidation. The molecular weight of LDPE films containing CSIR1% biobased additives decreased from 404K Mw to 111K Mw for sunlight oxidized samples and to 16KMw for the thermally oxidized LDPE samples after 200 days of oxidation exposure. Molecular weight of LDPE films containing CSIR3% biobased additives showed the most reduction from 293K Mw to 22K Mw for sunlight oxidized samples and to 2K Mw for thermally oxidized samples after 100 days of oxidation exposure. DSC analysis showed that crystallinity degree decreased after exposure to thermal and photo-oxidation. TGA results showed a reduction of initial degradation temperature by almost half compared to zero-days untreated CSIR3% samples, with higher degree temperatures observed in samples exposed to thermal oxidation than those exposed to photo-oxidation. GC-MS revealed peaks of carbonyls such as alcohols, aldehydes, ketones, carboxylic and anionic acids, and very short chain alkenes and alkanes. The SEM showed heterogeneous morphological modifications in surfaces of samples even though they were not severe. After 172 days the oxidized LDPE samples containing CSIR3% biobased additives, were investigated for potential biodegradation in aqueous, soil and composting environments. Thermally oxidized and photo-oxidized CSIR3% samples showed a mineralization degree of 10.4% and 10.7% respectively, when oxidized in 181 days aqueous biodegradation, 20% and 7.7% respectively, when oxidized in 233 days of soil burial, and 52.6% and 62% respectively, oxidized in 263 days of compost. The obtained results confirmed the abiotic oxidation step as the initiation step for PE degradation, succeeded by assimilation, by action of microorganisms (ultimate biodegradation), of lower weight molecular compounds of oxidized LDPE samples in aqueous medium, soil and composting conditions to final end products of CO2, H2O and new microbial cell biomass.
- Full Text:
- Date Issued: 2019
Truth and reconciliation and other stories: a critical multimodal investigation of representations of post-apartheid South Africa in children's picturebooks: volume 1
- Authors: Smith, Jade
- Date: 2019
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/97614 , vital:31458
- Description: Expected release date-April 2021
- Full Text: false
- Date Issued: 2019
- Authors: Smith, Jade
- Date: 2019
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/97614 , vital:31458
- Description: Expected release date-April 2021
- Full Text: false
- Date Issued: 2019