Absenting the absence of parallel learning pathways for intermediate skills: The ‘missing middle' in the environmental sector in South Africa
- Authors: Ramsarup, Presha
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/436964 , vital:73320 , ISBN 9781315660899 , https://www.routledge.com/Critical-Realism-Environmental-Learning-and-Social-Ecological-Change/Price-Lotz-Sistka/p/book/9780367597689
- Description: Environment and sustainable development are recognized for: their significance for the future of South Africa’s well-being; their complex, transversal nature; and their associated ‘new-ness’ within South African education and training systems. In a sector with relatively new occupations without clear learning pathways into jobs and where occupational contexts are rapid-ly changing with evolving skill needs, the chapter explores a critical realist dialectical view of learning pathways across sys-tems of work and learning. It highlights the need to develop more sophisticated understandings of learning pathways, and the way in which work, education and training systems inter-face to support the transitions needed for particular forms of work and learning. The chapter also explores how critical real-ist dialectics can help to explain more fully the absence of in-termediate pathways in the environment and sustainable de-velopment ‘sector’ in South Africa. It highlights the absences within the post-school provisioning system and through this analysis raises the patterns of emergence that characterize environmental learning pathways. This then advances an edu-cational critique that assists in the development of deeper knowledge of the object of the study (elements constituting learning pathways) in order to understand possibilities for change and to present opportunities for creating more seam-less environmental learning pathways into green jobs, enhanc-ing social justice potential and public good concerns.
- Full Text:
- Date Issued: 2015
- Authors: Ramsarup, Presha
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/436964 , vital:73320 , ISBN 9781315660899 , https://www.routledge.com/Critical-Realism-Environmental-Learning-and-Social-Ecological-Change/Price-Lotz-Sistka/p/book/9780367597689
- Description: Environment and sustainable development are recognized for: their significance for the future of South Africa’s well-being; their complex, transversal nature; and their associated ‘new-ness’ within South African education and training systems. In a sector with relatively new occupations without clear learning pathways into jobs and where occupational contexts are rapid-ly changing with evolving skill needs, the chapter explores a critical realist dialectical view of learning pathways across sys-tems of work and learning. It highlights the need to develop more sophisticated understandings of learning pathways, and the way in which work, education and training systems inter-face to support the transitions needed for particular forms of work and learning. The chapter also explores how critical real-ist dialectics can help to explain more fully the absence of in-termediate pathways in the environment and sustainable de-velopment ‘sector’ in South Africa. It highlights the absences within the post-school provisioning system and through this analysis raises the patterns of emergence that characterize environmental learning pathways. This then advances an edu-cational critique that assists in the development of deeper knowledge of the object of the study (elements constituting learning pathways) in order to understand possibilities for change and to present opportunities for creating more seam-less environmental learning pathways into green jobs, enhanc-ing social justice potential and public good concerns.
- Full Text:
- Date Issued: 2015
Accommodation and job assignment for impaired workers:
- Authors: Pearson, Jessie
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143661 , vital:38271 , https://ischp.files.wordpress.com/2015/08/ischp_2015_abstract_booklet.pdf
- Description: Some compensation systems do not encourage permanently restricted workers disabled due to work-related injuries, to return to work. However, appropriate job placement of impaired workers has been shown to result in feelings of independence, usefulness and responsibility, as well as financial security. Physically impaired employees in many workplaces have experienced job discrimination because colleagues and supervisors assume that their work performance will be affected by physical limitations resulting from their disability. This theoretical paper discusses the possibilities of assigning workers to appropriate jobs based on their specific capabilities and limitations. The option of providing certain job accommodations in the form of workplace restructuring is also discussed.
- Full Text:
- Date Issued: 2015
- Authors: Pearson, Jessie
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143661 , vital:38271 , https://ischp.files.wordpress.com/2015/08/ischp_2015_abstract_booklet.pdf
- Description: Some compensation systems do not encourage permanently restricted workers disabled due to work-related injuries, to return to work. However, appropriate job placement of impaired workers has been shown to result in feelings of independence, usefulness and responsibility, as well as financial security. Physically impaired employees in many workplaces have experienced job discrimination because colleagues and supervisors assume that their work performance will be affected by physical limitations resulting from their disability. This theoretical paper discusses the possibilities of assigning workers to appropriate jobs based on their specific capabilities and limitations. The option of providing certain job accommodations in the form of workplace restructuring is also discussed.
- Full Text:
- Date Issued: 2015
Addressing local level food insecurity amongst small-holder communities in transition
- Shackleton, Charlie M, Hamer, Nicholas G, Swallow, Brent M, Ncube, K
- Authors: Shackleton, Charlie M , Hamer, Nicholas G , Swallow, Brent M , Ncube, K
- Date: 2015
- Subjects: Food security -- South Africa Economic development -- South Africa Rural development -- South Africa
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/50090 , vital:25958
- Description: Food insecurity affects as significant proportion of the world's population and hence it typically receives priority attention in global policies associated with poverty, equity and sustainable development. For example, it is the first of the Millennium Development Goals and the second of their successor, the Sustainable Development Goals. Access to sufficient and nutritious food is deemed a basic human right. The latest FAO analysis of the “State of Food Insecurity in the World 2014” reports that 805 million people (approximately 11-12% of the world's population) are chronically undernourished (i.e. do not have sufficient energy intake over a period of at least one year). In sub-Saharan Africa the prevalence remains stubbornly high at 24%, the highest in the world. Whilst most interpret food insecurity to mean an insufficient quantity of food (as measured by the number of calories consumed), the widely accepted FAO definition considers four dimensions of food security, namely quantity, quality or diversity, access and use. Provision of enough calories on a daily basis is not sufficient if the diet lacks diversity and appropriate balance to provide the full range of minerals and vitamins necessary for proper health, or if the food available is culturally unacceptable. Thus, there is a pressing need for more nuanced analyses of food security against all four of the dimensions embedded in the concept. Additionally, it is important that these be measured at more local or regional levels because national statistics can mask alarming regional discrepancies in food security, or amongst particular sectors of society, such as recent migrants, refugees, female- or child-headed households, those vulnerable to HIV/AIDS or the landless, to mention just a few. For example, at a national level South Africa is considered a food secure nation with respect to staple requirements, and access to sufficient food is enshrined in the Constitution (Section 27, subsection 1b), but nationally one in twenty (i.e. approx. 2.5 million people) go to bed hungry most nights, and 23% of children below the age of 15 are physically stunted, severely stunted or wasted, due to the long-term ill effects of insufficient food or of inadequate diversity and quality. At a subnational level, there are marked differences between rural and urban populations and even between geographic areas (for example, the prevalence of stunting amongst boys less than 15 years old is 23% in the Eastern Cape, compared to 12% in Gauteng). Once again, despite being a food secure nation, nationally 40% of the population have a dietary diversity score of four or less, which is a cut-off point signifying poor dietary diversity which makes people more vulnerable to malnutrition and ill health, and in Limpopo and Northwest provinces it is as high as 66% and 61%, respectively.
- Full Text:
- Date Issued: 2015
- Authors: Shackleton, Charlie M , Hamer, Nicholas G , Swallow, Brent M , Ncube, K
- Date: 2015
- Subjects: Food security -- South Africa Economic development -- South Africa Rural development -- South Africa
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/50090 , vital:25958
- Description: Food insecurity affects as significant proportion of the world's population and hence it typically receives priority attention in global policies associated with poverty, equity and sustainable development. For example, it is the first of the Millennium Development Goals and the second of their successor, the Sustainable Development Goals. Access to sufficient and nutritious food is deemed a basic human right. The latest FAO analysis of the “State of Food Insecurity in the World 2014” reports that 805 million people (approximately 11-12% of the world's population) are chronically undernourished (i.e. do not have sufficient energy intake over a period of at least one year). In sub-Saharan Africa the prevalence remains stubbornly high at 24%, the highest in the world. Whilst most interpret food insecurity to mean an insufficient quantity of food (as measured by the number of calories consumed), the widely accepted FAO definition considers four dimensions of food security, namely quantity, quality or diversity, access and use. Provision of enough calories on a daily basis is not sufficient if the diet lacks diversity and appropriate balance to provide the full range of minerals and vitamins necessary for proper health, or if the food available is culturally unacceptable. Thus, there is a pressing need for more nuanced analyses of food security against all four of the dimensions embedded in the concept. Additionally, it is important that these be measured at more local or regional levels because national statistics can mask alarming regional discrepancies in food security, or amongst particular sectors of society, such as recent migrants, refugees, female- or child-headed households, those vulnerable to HIV/AIDS or the landless, to mention just a few. For example, at a national level South Africa is considered a food secure nation with respect to staple requirements, and access to sufficient food is enshrined in the Constitution (Section 27, subsection 1b), but nationally one in twenty (i.e. approx. 2.5 million people) go to bed hungry most nights, and 23% of children below the age of 15 are physically stunted, severely stunted or wasted, due to the long-term ill effects of insufficient food or of inadequate diversity and quality. At a subnational level, there are marked differences between rural and urban populations and even between geographic areas (for example, the prevalence of stunting amongst boys less than 15 years old is 23% in the Eastern Cape, compared to 12% in Gauteng). Once again, despite being a food secure nation, nationally 40% of the population have a dietary diversity score of four or less, which is a cut-off point signifying poor dietary diversity which makes people more vulnerable to malnutrition and ill health, and in Limpopo and Northwest provinces it is as high as 66% and 61%, respectively.
- Full Text:
- Date Issued: 2015
Africa in global International relations: emerging approaches to theory and practice: an introduction
- Bischoff, Paul, 1954-, Aning, Kwesi, Acharya, Amitav
- Authors: Bischoff, Paul, 1954- , Aning, Kwesi , Acharya, Amitav
- Date: 2015
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/161662 , vital:40651 , ISBN 9781317437536
- Description: This book investigates why Africa has been marginalised in IR discipline and theory and how this issue can be addressed in the context of the emerging Global IR paradigm. To have relevance for Africa, a new IR theory needs to be more inclusive, intellectually negotiated and holistically steeped in the African context. In this innovative volume, each author takes a critical look at existing IR paradigms and offers a unique perspective based on the African experience. Following on from Amitav Acharya and Barry Buzan’s work, Non-Western International Relations Theory, it develops and advances non-Western IR theory and the idea of Global IR.
- Full Text:
- Date Issued: 2015
- Authors: Bischoff, Paul, 1954- , Aning, Kwesi , Acharya, Amitav
- Date: 2015
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/161662 , vital:40651 , ISBN 9781317437536
- Description: This book investigates why Africa has been marginalised in IR discipline and theory and how this issue can be addressed in the context of the emerging Global IR paradigm. To have relevance for Africa, a new IR theory needs to be more inclusive, intellectually negotiated and holistically steeped in the African context. In this innovative volume, each author takes a critical look at existing IR paradigms and offers a unique perspective based on the African experience. Following on from Amitav Acharya and Barry Buzan’s work, Non-Western International Relations Theory, it develops and advances non-Western IR theory and the idea of Global IR.
- Full Text:
- Date Issued: 2015
Agathis bishopi (Hymenoptera: Braconidae) as a potential tool for detecting oranges infested with Thaumatotibia leucotreta (Lepidoptera: Tortricidae)
- Zimba, Kennedy J, Hill, Martin P, Moore, Sean D, Heshula, Unathi
- Authors: Zimba, Kennedy J , Hill, Martin P , Moore, Sean D , Heshula, Unathi
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/423955 , vital:72108 , xlink:href="https://doi.org/10.1007/s10905-015-9526-0"
- Description: In South Africa, Thaumatotibia leucotreta is a key pest of citrus impacting its production and trade. Detection of newly infested fruit by visual inspection is challenging and poses a risk of packing infested with healthy fruit for export. Agathis bishopi is a larval endoparasitoid of T. leucotreta, attacking early larval instars. Understanding how A. bishopi parasitoids locate fruit infested with their host is of interest for developing an efficient detector for T. leucotreta infested fruit. The response of female adult A. bishopi parasitoids to olfactory and visual cues associated with T. leucotreta infested fruit were evaluated using a Y-tube olfactometer and flight tunnel. Agathis bishopi parasitoids were strongly attracted to infested fruit over healthy fruit, either when only olfactory or combinations of visual and olfactory cues were offered. Among the four synthetic compounds tested, D-limonene and ocimene elicited a strong attraction to parasitoids with response rates of 92 % and 72 % respectively. A blend of four synthetic compounds simulating T. leucotreta infested fruit odour equally elicited strong attraction to parasitoids (84 % response rate). Attraction of parasitoids to infested fruit cues was heightened by prior experience, suggesting the occurrence of associative learning. Results from this study indicate that A. bishopi parasitoids mainly rely on olfactory cues in host habitat location and that D-limonene and ocimene are the major attractants in infested fruit volatiles. These findings and the potential for manipulating A. bishopi for detection of infested fruit in the packhouse are discussed.
- Full Text:
- Date Issued: 2015
- Authors: Zimba, Kennedy J , Hill, Martin P , Moore, Sean D , Heshula, Unathi
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/423955 , vital:72108 , xlink:href="https://doi.org/10.1007/s10905-015-9526-0"
- Description: In South Africa, Thaumatotibia leucotreta is a key pest of citrus impacting its production and trade. Detection of newly infested fruit by visual inspection is challenging and poses a risk of packing infested with healthy fruit for export. Agathis bishopi is a larval endoparasitoid of T. leucotreta, attacking early larval instars. Understanding how A. bishopi parasitoids locate fruit infested with their host is of interest for developing an efficient detector for T. leucotreta infested fruit. The response of female adult A. bishopi parasitoids to olfactory and visual cues associated with T. leucotreta infested fruit were evaluated using a Y-tube olfactometer and flight tunnel. Agathis bishopi parasitoids were strongly attracted to infested fruit over healthy fruit, either when only olfactory or combinations of visual and olfactory cues were offered. Among the four synthetic compounds tested, D-limonene and ocimene elicited a strong attraction to parasitoids with response rates of 92 % and 72 % respectively. A blend of four synthetic compounds simulating T. leucotreta infested fruit odour equally elicited strong attraction to parasitoids (84 % response rate). Attraction of parasitoids to infested fruit cues was heightened by prior experience, suggesting the occurrence of associative learning. Results from this study indicate that A. bishopi parasitoids mainly rely on olfactory cues in host habitat location and that D-limonene and ocimene are the major attractants in infested fruit volatiles. These findings and the potential for manipulating A. bishopi for detection of infested fruit in the packhouse are discussed.
- Full Text:
- Date Issued: 2015
Agathis bishopi, a larval parasitoid of false codling moth Thaumatotibia leucotreta: laboratory rearing and effect of adult food on parasitism and longevity
- Zimba, Kennedy J, Moore, Sean D, Heshula, LU, Hill, Martin P
- Authors: Zimba, Kennedy J , Moore, Sean D , Heshula, LU , Hill, Martin P
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/406985 , vital:70328 , xlink:href="https://hdl.handle.net/10520/EJC185849"
- Description: Agathis bishopi (Nixon) (Hymenoptera: Braconidae) is a koinobiont larval endoparasitoid of false codling moth (FCM), Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae), a pest of economic importance on citrus in South Africa. In the field Agathis bishopi was found to parasitise up to 34 % of FCM larvae in fruit, reflecting reasonable biocontrol potential. Improving the rearing of A. bishopi would therefore complement the existing biocontrol strategies for FCM. In several parasitic wasps, sugar concentration and feeding duration has been shown to influence parasitism and longevity. However, their effect on parasitism and longevity of A. bishopi is unknown. In the present study a rearing protocol for A. bishopi is described, including evaluation of the effects of honey concentration on parasitoid longevity. On average, 18.2%of FCM larvae in rearing containers were parasitised under the rearing protocol described. Cotton wool, instead of paper towelling, as honey carrier for feeding parasitoids in rearing containers significantly increased parasitism and yield of offspring. Furthermore, longevity significantly increased with higher concentrations of honey. Maximum lifespan duration for male and female parasitoids was achieved when parasitoids were fed on 36 % (w/v) honey. Results from this study indicate that A. bishopi requires a sufficient concentration of sugar, coupled with frequent and prolonged feeding on a cotton wool substrate, in order to achieve maximum parasitism and longevity. Such information provides a basis for optimising mass-rearing and longevity of A. bishopi and parasitism of FCM in orchards.
- Full Text:
- Date Issued: 2015
- Authors: Zimba, Kennedy J , Moore, Sean D , Heshula, LU , Hill, Martin P
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/406985 , vital:70328 , xlink:href="https://hdl.handle.net/10520/EJC185849"
- Description: Agathis bishopi (Nixon) (Hymenoptera: Braconidae) is a koinobiont larval endoparasitoid of false codling moth (FCM), Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae), a pest of economic importance on citrus in South Africa. In the field Agathis bishopi was found to parasitise up to 34 % of FCM larvae in fruit, reflecting reasonable biocontrol potential. Improving the rearing of A. bishopi would therefore complement the existing biocontrol strategies for FCM. In several parasitic wasps, sugar concentration and feeding duration has been shown to influence parasitism and longevity. However, their effect on parasitism and longevity of A. bishopi is unknown. In the present study a rearing protocol for A. bishopi is described, including evaluation of the effects of honey concentration on parasitoid longevity. On average, 18.2%of FCM larvae in rearing containers were parasitised under the rearing protocol described. Cotton wool, instead of paper towelling, as honey carrier for feeding parasitoids in rearing containers significantly increased parasitism and yield of offspring. Furthermore, longevity significantly increased with higher concentrations of honey. Maximum lifespan duration for male and female parasitoids was achieved when parasitoids were fed on 36 % (w/v) honey. Results from this study indicate that A. bishopi requires a sufficient concentration of sugar, coupled with frequent and prolonged feeding on a cotton wool substrate, in order to achieve maximum parasitism and longevity. Such information provides a basis for optimising mass-rearing and longevity of A. bishopi and parasitism of FCM in orchards.
- Full Text:
- Date Issued: 2015
Alexandra Fuller of Southern Africa: a white woman writer goes west
- Garman, Anthea, Rennie, Gillian
- Authors: Garman, Anthea , Rennie, Gillian
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159924 , vital:40356 , https://ialjs.org/wp-content/uploads/2015/05/134-147-LJS_v7n1.pdf
- Description: In terms of nationality, Alexandra Fuller is difficult to pigeonhole. She was born in England but from age two was brought up in Southern Africa (mostly Rhodesia). She married an American working in Zambia and then moved to Wyoming to raise a family. She has written three books about her family, their peripatetic life, and the violence of decolonizing Africa. The success of these works has made her one of the few African female nonfction writers to gain an international audience. Fuller’s longform journalism has been published in Granta and the Guardian in the United Kingdom, and in the New Yorker, Harper’s, National Geographic, Byliner, and Vogue in the United States. This paper traces the arc of a writer transcending her continent to break into the competitive American magazine market, portraying the complex land from which she has come for a foreign audience.
- Full Text:
- Date Issued: 2015
- Authors: Garman, Anthea , Rennie, Gillian
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159924 , vital:40356 , https://ialjs.org/wp-content/uploads/2015/05/134-147-LJS_v7n1.pdf
- Description: In terms of nationality, Alexandra Fuller is difficult to pigeonhole. She was born in England but from age two was brought up in Southern Africa (mostly Rhodesia). She married an American working in Zambia and then moved to Wyoming to raise a family. She has written three books about her family, their peripatetic life, and the violence of decolonizing Africa. The success of these works has made her one of the few African female nonfction writers to gain an international audience. Fuller’s longform journalism has been published in Granta and the Guardian in the United Kingdom, and in the New Yorker, Harper’s, National Geographic, Byliner, and Vogue in the United States. This paper traces the arc of a writer transcending her continent to break into the competitive American magazine market, portraying the complex land from which she has come for a foreign audience.
- Full Text:
- Date Issued: 2015
All about the abs: discourse of health in the negotiation of masculine body-image
- Authors: Plüg, Simóne
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143793 , vital:38283 , https://ischp.files.wordpress.com/2015/08/ischp_2015_abstract_booklet.pdf
- Description: This paper explores contemporary South African masculinities and how aspects of consumer culture interweave the self and body-image where “the prime purpose of the maintenance of the inner body becomes the enhancement of the appearance of the outer body” (Featherstone, 1991, p. 171). It details a study of young men in Durban, using a qualitative research design and a social constructionist theoretical framework to explore the discourses participants use when discussing their own and other male bodies. It highlights the ways in which consumerism, the media, and other social dynamics promote and silence different discourses around what constitutes a desirable man in 21st century South Africa. The paper presents a detailed exploration of the ‘healthy body’ discourse, discussing how it shaped men’s engagement in self-sculpting practices and provided a means by which the participants came to understand and manage their gendered identities.
- Full Text:
- Date Issued: 2015
- Authors: Plüg, Simóne
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143793 , vital:38283 , https://ischp.files.wordpress.com/2015/08/ischp_2015_abstract_booklet.pdf
- Description: This paper explores contemporary South African masculinities and how aspects of consumer culture interweave the self and body-image where “the prime purpose of the maintenance of the inner body becomes the enhancement of the appearance of the outer body” (Featherstone, 1991, p. 171). It details a study of young men in Durban, using a qualitative research design and a social constructionist theoretical framework to explore the discourses participants use when discussing their own and other male bodies. It highlights the ways in which consumerism, the media, and other social dynamics promote and silence different discourses around what constitutes a desirable man in 21st century South Africa. The paper presents a detailed exploration of the ‘healthy body’ discourse, discussing how it shaped men’s engagement in self-sculpting practices and provided a means by which the participants came to understand and manage their gendered identities.
- Full Text:
- Date Issued: 2015
Amoxicillin removal from aqueous media using multi-walled carbon nanotubes
- Mohammadi, Ali, Kazemipour, Maryam, Walker, Roderick B, Ansari, Mehdi
- Authors: Mohammadi, Ali , Kazemipour, Maryam , Walker, Roderick B , Ansari, Mehdi
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/183861 , vital:44076 , xlink:href="https://doi.org/10.1080/1536383X.2013.866944"
- Description: Multi-walled carbon nanotubes (MWCNT) were used to separate amoxicillin from aqueous media. The parameters affecting amoxicillin adsorption such as pH, temperature, time, interferences of similar molecules, and the amount of adsorbent used were studied. Amoxicillin adsorption using MWCNT was compared to that using Fullerene C60 and activated carbon (AC). The adsorption efficiency of 0.1 and 0.2 g of MWCNT using in a continuous mode were 86.5% and 87.9%, respectively. Evaluation of the adsorbent capacity showed that each gram of MWCNT can absorb 22.9 mg amoxicillin. The effect of pH was studied over the range 2–8 and revealed that adsorption of the amoxicillin at the initial pH of 4.6 was more effective than any other pH. The adsorption of amoxicillin on MWCNT was much greater than Fullerene C60 and AC. Adsorption data showed that they were best fitted to the Langmuir isotherm.
- Full Text:
- Date Issued: 2015
- Authors: Mohammadi, Ali , Kazemipour, Maryam , Walker, Roderick B , Ansari, Mehdi
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/183861 , vital:44076 , xlink:href="https://doi.org/10.1080/1536383X.2013.866944"
- Description: Multi-walled carbon nanotubes (MWCNT) were used to separate amoxicillin from aqueous media. The parameters affecting amoxicillin adsorption such as pH, temperature, time, interferences of similar molecules, and the amount of adsorbent used were studied. Amoxicillin adsorption using MWCNT was compared to that using Fullerene C60 and activated carbon (AC). The adsorption efficiency of 0.1 and 0.2 g of MWCNT using in a continuous mode were 86.5% and 87.9%, respectively. Evaluation of the adsorbent capacity showed that each gram of MWCNT can absorb 22.9 mg amoxicillin. The effect of pH was studied over the range 2–8 and revealed that adsorption of the amoxicillin at the initial pH of 4.6 was more effective than any other pH. The adsorption of amoxicillin on MWCNT was much greater than Fullerene C60 and AC. Adsorption data showed that they were best fitted to the Langmuir isotherm.
- Full Text:
- Date Issued: 2015
An analysis of ethics and governance practices in the public sector: United Nations and African Union perspectives
- Authors: Shindika, Emmanuel Selemani
- Date: 2015
- Subjects: United Nations , African Union , Public administration -- Moral and ethical aspects
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/26164 , vital:64946
- Description: Recent studies highlight the importance of improving governance and ethics in public entities, especially in Africa. However, doing so requires an understanding on what forms governance and ethics in public institutions, particularly at a national level. Such considerations necessitates that some focus on continental and world institutions, such as, the African Union and the United Nations. These institutions have been in existence for a number of years with mandates of improving member states governance and ethics, as well as, service delivery to the public. As such, this research primarily focuses on understanding the roles played by the AU and the UN in shaping governance and ethics to member states, as well as, of its employees. The focus of this inquiry was to understand individual narratives about how working for public institutions on a daily to day basis influences governance and ethics understanding and application. Therefore, in order to properly analyse the narratives from respondents, the study applied an inductive and qualitative approach in order to explore how the AU and UN systems influence governance and ethics for member s states and employees. Data was collected through semi structured interviews with UN and AU officials, as well as public servants of member states for those organisations. The study made use of a thematic analyses method of interpreting data. A total of six major themes emerged, they are as follows: ethics a part in governance; effectiveness of AU and UN systems; disciplinary role; ethical guidelines and standards influence on public sector; member states adherence to the UN/AU ethical conduct; and implementation gaps in ethical guidelines within member states. Interviews were conducted in four countries namely; South Africa, Tanzania, Mauritius and Botswana. Findings from the study pointed that the AU and UN systems have loopholes in dealing with issues of governance and ethics. Moreover, member states respondents also pointed to the loopholes in those two organisations. The research suggests that member states should tighten their public entities ethical compliance assessments and follow suggestions from the UN and AU. Final recommendations and suggestions for further research are provided. , Thesis (PhD) -- Faculty of Management and Commerce, 2015
- Full Text:
- Date Issued: 2015
- Authors: Shindika, Emmanuel Selemani
- Date: 2015
- Subjects: United Nations , African Union , Public administration -- Moral and ethical aspects
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/26164 , vital:64946
- Description: Recent studies highlight the importance of improving governance and ethics in public entities, especially in Africa. However, doing so requires an understanding on what forms governance and ethics in public institutions, particularly at a national level. Such considerations necessitates that some focus on continental and world institutions, such as, the African Union and the United Nations. These institutions have been in existence for a number of years with mandates of improving member states governance and ethics, as well as, service delivery to the public. As such, this research primarily focuses on understanding the roles played by the AU and the UN in shaping governance and ethics to member states, as well as, of its employees. The focus of this inquiry was to understand individual narratives about how working for public institutions on a daily to day basis influences governance and ethics understanding and application. Therefore, in order to properly analyse the narratives from respondents, the study applied an inductive and qualitative approach in order to explore how the AU and UN systems influence governance and ethics for member s states and employees. Data was collected through semi structured interviews with UN and AU officials, as well as public servants of member states for those organisations. The study made use of a thematic analyses method of interpreting data. A total of six major themes emerged, they are as follows: ethics a part in governance; effectiveness of AU and UN systems; disciplinary role; ethical guidelines and standards influence on public sector; member states adherence to the UN/AU ethical conduct; and implementation gaps in ethical guidelines within member states. Interviews were conducted in four countries namely; South Africa, Tanzania, Mauritius and Botswana. Findings from the study pointed that the AU and UN systems have loopholes in dealing with issues of governance and ethics. Moreover, member states respondents also pointed to the loopholes in those two organisations. The research suggests that member states should tighten their public entities ethical compliance assessments and follow suggestions from the UN and AU. Final recommendations and suggestions for further research are provided. , Thesis (PhD) -- Faculty of Management and Commerce, 2015
- Full Text:
- Date Issued: 2015
An analysis of schooling outcomes in the Eastern Cape, using production function approach
- Authors: Ncanywa, Thobeka
- Date: 2015
- Subjects: Education -- Economic aspects , Production functions (Economic theory) , School management and organization
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/26570 , vital:65656
- Description: This study analysed the schooling outcomes of the Eastern Cape Department of Basic Education in the period heading into the second decade of democracy. The main objective of the thesis is to discover what constitutes the education production function of the Eastern Cape schooling system. In an attempt to reach this objective, the study adopted an education production function approach to answer the questions of what constitute the Eastern Cape education production function, what the effects are of the Dinaledi policy interventions on learner performance and the effects of district size on schooling outcomes. The main focus of the constituents of the production function is on the level of the former Bantustan penalty and Department of Education and Training (DET) penalty in relation to former White schools; as well as the quality of educators in the province. The Ordinary Least Squares (OLS) and quantile regressions were used to analyse the data and the Annual National Assessment (ANA) represented schooling outcomes and was estimated against school, educator and community characteristics. The results indicated a strong relationship between schooling outcomes and the school inputs that were used in the study. The effects of the Dinaledi intervention programme were analysed using the grade 12 panel data for the period from 2008 to 2013, where event dropout rates represented schooling outcomes. The findings that emerged from this study indicated that this programme provides a model that can improve the Eastern Cape schooling outcomes. The effects of district size on schooling outcomes were analysed with the regression discontinuity design technique and this revealed that district sizes have an impact on schooling outcomes. Overall, the results suggested that White schools perform better than their counterparts; that placing schools in quintiles is a good policy intervention; and that educator quality is associated with schooling outcomes. The key findings from this research were the continuing existence of the apartheid legacy in Black schools; poor educator quality; an inappropriate language of instruction; gender inequalities in performance and an uneven distribution of schools in districts. The recommendations for this research are to pay more attention to the improvement of educator quality in terms of educator qualifications, training and remuneration; implement a programme like the Dinaledi programme to all schools, as it provides resources to schools; and enforce the district size as informed by the district act so as to improve the support that district officials give to schools. , Thesis (PhD) -- Faculty of Management and Commerce, 2015
- Full Text:
- Date Issued: 2015
- Authors: Ncanywa, Thobeka
- Date: 2015
- Subjects: Education -- Economic aspects , Production functions (Economic theory) , School management and organization
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/26570 , vital:65656
- Description: This study analysed the schooling outcomes of the Eastern Cape Department of Basic Education in the period heading into the second decade of democracy. The main objective of the thesis is to discover what constitutes the education production function of the Eastern Cape schooling system. In an attempt to reach this objective, the study adopted an education production function approach to answer the questions of what constitute the Eastern Cape education production function, what the effects are of the Dinaledi policy interventions on learner performance and the effects of district size on schooling outcomes. The main focus of the constituents of the production function is on the level of the former Bantustan penalty and Department of Education and Training (DET) penalty in relation to former White schools; as well as the quality of educators in the province. The Ordinary Least Squares (OLS) and quantile regressions were used to analyse the data and the Annual National Assessment (ANA) represented schooling outcomes and was estimated against school, educator and community characteristics. The results indicated a strong relationship between schooling outcomes and the school inputs that were used in the study. The effects of the Dinaledi intervention programme were analysed using the grade 12 panel data for the period from 2008 to 2013, where event dropout rates represented schooling outcomes. The findings that emerged from this study indicated that this programme provides a model that can improve the Eastern Cape schooling outcomes. The effects of district size on schooling outcomes were analysed with the regression discontinuity design technique and this revealed that district sizes have an impact on schooling outcomes. Overall, the results suggested that White schools perform better than their counterparts; that placing schools in quintiles is a good policy intervention; and that educator quality is associated with schooling outcomes. The key findings from this research were the continuing existence of the apartheid legacy in Black schools; poor educator quality; an inappropriate language of instruction; gender inequalities in performance and an uneven distribution of schools in districts. The recommendations for this research are to pay more attention to the improvement of educator quality in terms of educator qualifications, training and remuneration; implement a programme like the Dinaledi programme to all schools, as it provides resources to schools; and enforce the district size as informed by the district act so as to improve the support that district officials give to schools. , Thesis (PhD) -- Faculty of Management and Commerce, 2015
- Full Text:
- Date Issued: 2015
An assessment of chlorophyll-a concentration spatio-temporal variation using Landsat satellite data, in a small tropical reservoir
- Dalu, Tatenda, Dube, Timothy, Froneman, P William, Sachikonye, Mwazvita T B, Clegg, Bruce W, Nhiwatiwa, Tamuka
- Authors: Dalu, Tatenda , Dube, Timothy , Froneman, P William , Sachikonye, Mwazvita T B , Clegg, Bruce W , Nhiwatiwa, Tamuka
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68042 , vital:29189 , https://doi.org/10.1080/10106049.2015.1027292
- Description: Publisher version , Traditional approaches to monitoring aquatic systems are often limited by the need for data collection which often is time-consuming, expensive and non-continuous. The aim of the study was to map the spatio-temporal chlorophyll-a concentration changes in Malilangwe Reservoir, Zimbabwe as an indicator of phytoplankton biomass and trophic state when the reservoir was full (year 2000) and at its lowest capacity (year 2011), using readily available Landsat multispectral images. Medium-spatial resolution (30 m) Landsat multispectral Thematic Mapper TM 5 and ETM+ images for May to December 1999–2000 and 2010–2011 were used to derive chlorophyll-a concentrations. In situ measured chlorophyll-a and total suspended solids (TSS) concentrations for 2011 were employed to validate the Landsat chlorophyll-a and TSS estimates. The study results indicate that Landsat-derived chlorophyll-a and TSS estimates were comparable with field measurements. There was a considerable wet vs. dry season differences in total chlorophyll-a concentration, Secchi disc depth, TSS and turbidity within the reservoir. Using Permutational multivariate analyses of variance (PERMANOVA) analysis, there were significant differences (p < 0.0001) for chlorophyll-a concentration among sites, months and years whereas TSS was significant during the study months (p < 0.05). A strong positive significant correlation among both predicted TSS vs. chlorophyll-a and measured vs. predicted chlorophyll-a and TSS concentrations as well as an inverse relationship between reservoir chlorophyll-a concentrations and water level were found (p < 0.001 in all cases). In conclusion, total chlorophyll-a concentration in Malilangwe Reservoir was successfully derived from Landsat remote sensing data suggesting that the Landsat sensor is suitable for real-time monitoring over relatively short timescales and for small reservoirs. Satellite data can allow for surveying of chlorophyll-a concentration in aquatic ecosystems, thus, providing invaluable data in data scarce (limited on site ground measurements) environments.
- Full Text: false
- Date Issued: 2015
- Authors: Dalu, Tatenda , Dube, Timothy , Froneman, P William , Sachikonye, Mwazvita T B , Clegg, Bruce W , Nhiwatiwa, Tamuka
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68042 , vital:29189 , https://doi.org/10.1080/10106049.2015.1027292
- Description: Publisher version , Traditional approaches to monitoring aquatic systems are often limited by the need for data collection which often is time-consuming, expensive and non-continuous. The aim of the study was to map the spatio-temporal chlorophyll-a concentration changes in Malilangwe Reservoir, Zimbabwe as an indicator of phytoplankton biomass and trophic state when the reservoir was full (year 2000) and at its lowest capacity (year 2011), using readily available Landsat multispectral images. Medium-spatial resolution (30 m) Landsat multispectral Thematic Mapper TM 5 and ETM+ images for May to December 1999–2000 and 2010–2011 were used to derive chlorophyll-a concentrations. In situ measured chlorophyll-a and total suspended solids (TSS) concentrations for 2011 were employed to validate the Landsat chlorophyll-a and TSS estimates. The study results indicate that Landsat-derived chlorophyll-a and TSS estimates were comparable with field measurements. There was a considerable wet vs. dry season differences in total chlorophyll-a concentration, Secchi disc depth, TSS and turbidity within the reservoir. Using Permutational multivariate analyses of variance (PERMANOVA) analysis, there were significant differences (p < 0.0001) for chlorophyll-a concentration among sites, months and years whereas TSS was significant during the study months (p < 0.05). A strong positive significant correlation among both predicted TSS vs. chlorophyll-a and measured vs. predicted chlorophyll-a and TSS concentrations as well as an inverse relationship between reservoir chlorophyll-a concentrations and water level were found (p < 0.001 in all cases). In conclusion, total chlorophyll-a concentration in Malilangwe Reservoir was successfully derived from Landsat remote sensing data suggesting that the Landsat sensor is suitable for real-time monitoring over relatively short timescales and for small reservoirs. Satellite data can allow for surveying of chlorophyll-a concentration in aquatic ecosystems, thus, providing invaluable data in data scarce (limited on site ground measurements) environments.
- Full Text: false
- Date Issued: 2015
An Assessment of the Effect of Rotenone on Selected Non-Target Aquatic Fauna
- Dalu, Tatenda, Wasserman, Ryan J, Jordaan, Martine, Froneman, P William, Froneman, Pierre William, Weyl, Olaf L F
- Authors: Dalu, Tatenda , Wasserman, Ryan J , Jordaan, Martine , Froneman, P William , Froneman, Pierre William , Weyl, Olaf L F
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124240 , vital:35579 , https://doi.org/10.1371/journal.pone.0142140.g001
- Description: Rotenone, a naturally occurring ketone, is widely employed for the management of invasive fish species. The use of rotenone poses serious challenges to conservation practitioners due to its impacts on non-target organisms including amphibians and macroinvertebrates. Using laboratory studies, we investigated the effects of different rotenone concentrations (0, 12.5, 25, 37.5, 50, 100 μg L-1) on selected invertebrate groups; Aeshnidae, Belostomatids, Decapods, Ephemeroptera, Pulmonata and zooplankton over a period of 18 hours. Based on field observations and body size, we hypothesized that Ephemeropterans and zooplank- ton would be more susceptible to rote none than Decapods, Belostomatids and snails. Experimental results supported this hypothesis and mortality and behaviour effects varied considerably between taxa, ranging from no effect (crab Potamonuates sidneyi) to 100% mortality (Daphnia pulex and Paradiaptomus lamellatus). Planktonic invertebrates were par- ticularly sensitive to rotenone even at very low concentrations. Future research should investigate the recovery time of invertebrate communities after the application of rotenone and conduct field assessments assessing the longer term effects of rotenone exposure on the population dynamics of those less sensitive organisms.
- Full Text:
- Date Issued: 2015
- Authors: Dalu, Tatenda , Wasserman, Ryan J , Jordaan, Martine , Froneman, P William , Froneman, Pierre William , Weyl, Olaf L F
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124240 , vital:35579 , https://doi.org/10.1371/journal.pone.0142140.g001
- Description: Rotenone, a naturally occurring ketone, is widely employed for the management of invasive fish species. The use of rotenone poses serious challenges to conservation practitioners due to its impacts on non-target organisms including amphibians and macroinvertebrates. Using laboratory studies, we investigated the effects of different rotenone concentrations (0, 12.5, 25, 37.5, 50, 100 μg L-1) on selected invertebrate groups; Aeshnidae, Belostomatids, Decapods, Ephemeroptera, Pulmonata and zooplankton over a period of 18 hours. Based on field observations and body size, we hypothesized that Ephemeropterans and zooplank- ton would be more susceptible to rote none than Decapods, Belostomatids and snails. Experimental results supported this hypothesis and mortality and behaviour effects varied considerably between taxa, ranging from no effect (crab Potamonuates sidneyi) to 100% mortality (Daphnia pulex and Paradiaptomus lamellatus). Planktonic invertebrates were par- ticularly sensitive to rotenone even at very low concentrations. Future research should investigate the recovery time of invertebrate communities after the application of rotenone and conduct field assessments assessing the longer term effects of rotenone exposure on the population dynamics of those less sensitive organisms.
- Full Text:
- Date Issued: 2015
An assessment of the effect of rotenone on selected non-target aquatic fauna:
- Dalu, Tatenda, Wasserman, Ryan J, Jordaan, Martine, Froneman, P William, Weyl, Olaf L F
- Authors: Dalu, Tatenda , Wasserman, Ryan J , Jordaan, Martine , Froneman, P William , Weyl, Olaf L F
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143247 , vital:38214 , https://doi.org/10.1371/journal.pone.0142140
- Description: Rotenone, a naturally occurring ketone, is widely employed for the management of invasive fish species. The use of rotenone poses serious challenges to conservation practitioners due to its impacts on non-target organisms including amphibians and macroinvertebrates. Using laboratory studies, we investigated the effects of different rotenone concentrations (0, 12.5, 25, 37.5, 50, 100 μg L-1) on selected invertebrate groups; Aeshnidae, Belostomatids, Decapods, Ephemeroptera, Pulmonata and zooplankton over a period of 18 hours. Based on field observations and body size, we hypothesized that Ephemeropterans and zooplankton would be more susceptible to rotenone than Decapods, Belostomatids and snails.
- Full Text:
- Date Issued: 2015
- Authors: Dalu, Tatenda , Wasserman, Ryan J , Jordaan, Martine , Froneman, P William , Weyl, Olaf L F
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143247 , vital:38214 , https://doi.org/10.1371/journal.pone.0142140
- Description: Rotenone, a naturally occurring ketone, is widely employed for the management of invasive fish species. The use of rotenone poses serious challenges to conservation practitioners due to its impacts on non-target organisms including amphibians and macroinvertebrates. Using laboratory studies, we investigated the effects of different rotenone concentrations (0, 12.5, 25, 37.5, 50, 100 μg L-1) on selected invertebrate groups; Aeshnidae, Belostomatids, Decapods, Ephemeroptera, Pulmonata and zooplankton over a period of 18 hours. Based on field observations and body size, we hypothesized that Ephemeropterans and zooplankton would be more susceptible to rotenone than Decapods, Belostomatids and snails.
- Full Text:
- Date Issued: 2015
An Assessment of the Effect of Rotenone on Selected Non-Target Aquatic Fauna: Reflections on Henri Lefebre, Urban Theory and the Politics of Scale
- Dalu, Tatenda, Wasserman, Ryan J, Jordaan, Martine, Froneman, Pierre William
- Authors: Dalu, Tatenda , Wasserman, Ryan J , Jordaan, Martine , Froneman, Pierre William
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/70425 , vital:29654 , https://doi.org/10.1371/journal.pone.0142140
- Description: Rotenone, a naturally occurring ketone, is widely employed for the management of invasive fish species. The use of rotenone poses serious challenges to conservation practitioners due to its impacts on non-target organisms including amphibians and macroinvertebrates. Using laboratory studies, we investigated the effects of different rotenone concentrations (0,12.5, 25, 37.5, 50, 100 μg L-1) on selected invertebrate groups; Aeshnidae, Belostomatids, Decapods, Ephemeroptera, Pulmonata and zooplankton over a period of 18 hours. Based on field observations and body size, we hypothesized that Ephemeropterans and zooplankton would be more susceptible to rotenone than Decapods, Belostomatids and snails. Experimental results supported this hypothesis and mortality and behaviour effects varied considerably between taxa, ranging from no effect (crab Potamonuates sidneyi) to 100% mortality (Daphnia pulex and Paradiaptomus lamellatus). Planktonic invertebrates were particularly sensitive to rotenone even at very low concentrations. Future research should investigate the recovery time of invertebrate communities after the application of rotenone and conduct field assessments assessing the longer term effects of rotenone exposure on the population dynamics of those less sensitive organisms.
- Full Text:
- Date Issued: 2015
- Authors: Dalu, Tatenda , Wasserman, Ryan J , Jordaan, Martine , Froneman, Pierre William
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/70425 , vital:29654 , https://doi.org/10.1371/journal.pone.0142140
- Description: Rotenone, a naturally occurring ketone, is widely employed for the management of invasive fish species. The use of rotenone poses serious challenges to conservation practitioners due to its impacts on non-target organisms including amphibians and macroinvertebrates. Using laboratory studies, we investigated the effects of different rotenone concentrations (0,12.5, 25, 37.5, 50, 100 μg L-1) on selected invertebrate groups; Aeshnidae, Belostomatids, Decapods, Ephemeroptera, Pulmonata and zooplankton over a period of 18 hours. Based on field observations and body size, we hypothesized that Ephemeropterans and zooplankton would be more susceptible to rotenone than Decapods, Belostomatids and snails. Experimental results supported this hypothesis and mortality and behaviour effects varied considerably between taxa, ranging from no effect (crab Potamonuates sidneyi) to 100% mortality (Daphnia pulex and Paradiaptomus lamellatus). Planktonic invertebrates were particularly sensitive to rotenone even at very low concentrations. Future research should investigate the recovery time of invertebrate communities after the application of rotenone and conduct field assessments assessing the longer term effects of rotenone exposure on the population dynamics of those less sensitive organisms.
- Full Text:
- Date Issued: 2015
An exploration of business level strategy at the bottom of the pyramid: a case study of Twizza, Eastern Cape
- Authors: Sityoshwana, Ludwe Lusu
- Date: 2015
- Language: English
- Type: text , Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10962/54486 , vital:26569
- Description: This qualitative study focuses on business level strategy adopted by Twizza to compete in the bottom of the pyramid market in the Eastern Cape, South Africa. Twizza enjoyed huge success between the years 2010 - 2014 as a medium to large sized manufacturer of carbonated soft drinks in the Eastern Cape. In light of this, the current study seeks to answer the following: What business level strategy did top management at Twizza adopt to compete and grow in the BoP market in the Eastern Cape, South Africa? The study takes the form of a case study to explore and understand the patterns of decisions adopted by Twizza’s top management in competing at the bottom of the pyramid. As such, the main objective of the study was to identify the business level strategy adopted by Twizza which enabled their superior performance within the BoP market. The study adopts Porter`s typology to explore business level strategy. Stratified, purposive sampling was used to identify 4 top managers as participants in this study. A total of 7, semi-structured, interviews were used to collect critical incidents from top management of Twizza. This was the primary data used in this study. This type of data was combined with relevant information which was gathered via published press articles and on-line commentary. The study found that central to Twizza’s business strategy were four pillars, namely, strict control and management of manufacturing costs, product quality equal to that of market leaders, the ability of the organisation to manufacture its own raw materials and ability to ensure product availability to the market to the market. These findings reveal that Twizza employed a hybrid strategy, anchored by cost leadership. Thus, Twizza incorporated elements of differentiation and best value strategies to offer its customers affordable quality.
- Full Text:
- Date Issued: 2015
- Authors: Sityoshwana, Ludwe Lusu
- Date: 2015
- Language: English
- Type: text , Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10962/54486 , vital:26569
- Description: This qualitative study focuses on business level strategy adopted by Twizza to compete in the bottom of the pyramid market in the Eastern Cape, South Africa. Twizza enjoyed huge success between the years 2010 - 2014 as a medium to large sized manufacturer of carbonated soft drinks in the Eastern Cape. In light of this, the current study seeks to answer the following: What business level strategy did top management at Twizza adopt to compete and grow in the BoP market in the Eastern Cape, South Africa? The study takes the form of a case study to explore and understand the patterns of decisions adopted by Twizza’s top management in competing at the bottom of the pyramid. As such, the main objective of the study was to identify the business level strategy adopted by Twizza which enabled their superior performance within the BoP market. The study adopts Porter`s typology to explore business level strategy. Stratified, purposive sampling was used to identify 4 top managers as participants in this study. A total of 7, semi-structured, interviews were used to collect critical incidents from top management of Twizza. This was the primary data used in this study. This type of data was combined with relevant information which was gathered via published press articles and on-line commentary. The study found that central to Twizza’s business strategy were four pillars, namely, strict control and management of manufacturing costs, product quality equal to that of market leaders, the ability of the organisation to manufacture its own raw materials and ability to ensure product availability to the market to the market. These findings reveal that Twizza employed a hybrid strategy, anchored by cost leadership. Thus, Twizza incorporated elements of differentiation and best value strategies to offer its customers affordable quality.
- Full Text:
- Date Issued: 2015
An exploration of the principle of Dance Movement Therapy in water resource management research practice:
- Authors: Copteros, Athina
- Date: 2015
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/142016 , vital:38024 , ISBN PECS Conference: Social-ecological dynamics in the Anthropocene, Spier Estate, Cape Town, 2-5 November , http://www.pecs-science.org/research/news/news/2015pecsconferencesocialecologicaldynamicsintheanthropocene.5.40768cbb14b32a0480b694.html
- Description: An exploration of the principle of Dance Movement Therapy in water resource management research practice
- Full Text:
- Date Issued: 2015
- Authors: Copteros, Athina
- Date: 2015
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/142016 , vital:38024 , ISBN PECS Conference: Social-ecological dynamics in the Anthropocene, Spier Estate, Cape Town, 2-5 November , http://www.pecs-science.org/research/news/news/2015pecsconferencesocialecologicaldynamicsintheanthropocene.5.40768cbb14b32a0480b694.html
- Description: An exploration of the principle of Dance Movement Therapy in water resource management research practice
- Full Text:
- Date Issued: 2015
An investigation into the feasibility of incorporating ketoconazole into solid lipid microparticles
- Authors: Jhundoo, Henusha Devi
- Date: 2015
- Language: English
- Type: text , Thesis , Masters , MPharm
- Identifier: http://hdl.handle.net/10962/54701 , vital:26601
- Description: One of the major challenges of the oral administration of ketoconazole (KTZ), an inhibitor of sterol 14α demethylase, used in the management of systemic and topical mycoses in immuno-compromised and paediatric patients is the lack of availability of liquid dosage forms. In order to overcome this challenge, extemporaneous preparations have been manufactured by care-givers and health care providers by crushing or breaking solid oral dosage forms of KTZ and mixing with a vehicle to produce a liquid dosage form that can be swallowed by patients. However, the use of extemporaneous preparations may lead to under or over-dosing if the care-givers are not guided accordingly. Furthermore, the dearth of information on the stability of these KTZ-containing extemporaneous preparations may lead to ineffective antifungal therapy and complicate the problems of resistance as it is difficult to estimate the shelf-lives of these extemporaneous products under varying storage conditions due to the susceptibility of KTZ to chemical degradation. Therefore, there is a need for formulation scientists to develop novel drug delivery systems that avoid the need for extemporaneous preparations, possess well-established limits of stability and minimize the risks of systemic adverse effects to facilitate KTZ therapy. The use of solid lipid microparticles (SLM) as potential carriers for the oral administration of KTZ was investigated since solid lipid carriers are known to exhibit the advantages of traditional colloidal carriers. The research undertaken in these studies aimed to investigate the feasibility of developing and manufacturing solid lipid microparticles (SLM), using a simple micro-emulsion technique, as a carrier for KTZ. Prior to pre-formulation, formulation development and optimization studies of KTZ-loaded SLM, it was necessary to develop and validate an analytical method for the in vitro quantitation and characterization of KTZ in aqueous dispersions of SLM during development and assessment studies. An accurate, precise, specific and sensitive reversed-phase high performance liquid chromatographic (RP-HPLC) method coupled with UV detection at 206 nm was developed, optimized and validated for the analysis of KTZ in formulations. Formulation development studies were preceded by solubility studies of KTZ in different lipids. Labrafil® M2130 CS was found to exhibit the best solubilising potential for KTZ. Pre-formulation studies were also designed to determine the polymorphic behavior and the crystallinity of KTZ and Labrafil® M2130 CS that was used for subsequent manufacture of the solid lipid carriers. DSC and FTIR studies revealed that there were no changes in the crystallinity of KTZ or Labrafil® M2130 CS following exposure to a temperature of 60°C for 1 hour. In addition the potential for physicochemical interaction of KTZ with the lipid Labrafil® M2130 CS was investigated using DSC and FTIR and the results revealed that KTZ was molecularly dispersed in Labrafil® M2130 CS and that it is unlikely that KTZ would interact with the lipid. It was therefore established that KTZ and Labrafil® M2130 CS were thermo-stable at a temperature of 60°C and thus a micro-emulsion technique could be used to manufacture the KTZ-loaded SLM. Drug-free and KTZ-loaded SLM were prepared using a modified micro-emulsion technique that required the use of an Ultra-Turrax® homogenizer set at 24 000 rpm for 5 minutes followed by the use of the Erweka GmbH homogenizer. SLM were characterized in terms of particle size (PS), zeta potential (ZP), shape and surface morphology using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). In addition drug loading capacity (DLC) and encapsulation efficiency (EE) of SLM for KTZ were assessed using RP-HPLC. Formulation development and optimization studies of KTZ-loaded SLM were initially aimed at selecting an emulsifying system that was able to stabilize the SLM in an aqueous dispersion. Successful formulations were selected based on their ability to remain physically stable on the day of manufacture. Pluronic® F68 used in combination with Lutrol® E40, Soluphor® P, Soluplus® produced unstable dispersions on the day of manufacture and these combinations were not investigated further. However, the formulation of a stable KTZ-loaded SLM dispersion was accomplished by use of a combination of Pluronic® F68, Tween 80 and sodium cholate as the surfactant system. Increasing amounts of Labrafil® M2130 CS resulted in the production of particles with low DLC and EE, a large PS and a relatively unchanged ZP. An optimum concentration of 10% w/v Labrafil® M2130 CS was selected to manufacture the KTZ-loaded SLM. Studies to determine the influence of KTZ loading on the quality of SLM revealed that concentrations of KTZ > 5% w/v led to a reduction in DLC and EE and an increase in PS with minimal impact on the ZP. Stability studies conducted at 25°C/65% RH and 40°C/75% RH for up to 30 days following manufacture revealed that batch SLM 15 manufactured using 10% w/v Labrafil® M2130 CS, 5% w/v KTZ and a combination of 4% w/v Pluronic® F-68, 2% w/v Tween 80 and 1% w/v sodium cholate produced the most stable dosage form when stored at 25°C/65% RH for up to 30 days. However, storage at 40°C/75% RH resulted in instability of the formulation. An aqueous dispersion of KTZ-loaded SLM has been developed and assessed and may offer an alternative to extemporaneous preparations used for KTZ therapy in paediatric and immuno-compromised patients.
- Full Text:
- Date Issued: 2015
- Authors: Jhundoo, Henusha Devi
- Date: 2015
- Language: English
- Type: text , Thesis , Masters , MPharm
- Identifier: http://hdl.handle.net/10962/54701 , vital:26601
- Description: One of the major challenges of the oral administration of ketoconazole (KTZ), an inhibitor of sterol 14α demethylase, used in the management of systemic and topical mycoses in immuno-compromised and paediatric patients is the lack of availability of liquid dosage forms. In order to overcome this challenge, extemporaneous preparations have been manufactured by care-givers and health care providers by crushing or breaking solid oral dosage forms of KTZ and mixing with a vehicle to produce a liquid dosage form that can be swallowed by patients. However, the use of extemporaneous preparations may lead to under or over-dosing if the care-givers are not guided accordingly. Furthermore, the dearth of information on the stability of these KTZ-containing extemporaneous preparations may lead to ineffective antifungal therapy and complicate the problems of resistance as it is difficult to estimate the shelf-lives of these extemporaneous products under varying storage conditions due to the susceptibility of KTZ to chemical degradation. Therefore, there is a need for formulation scientists to develop novel drug delivery systems that avoid the need for extemporaneous preparations, possess well-established limits of stability and minimize the risks of systemic adverse effects to facilitate KTZ therapy. The use of solid lipid microparticles (SLM) as potential carriers for the oral administration of KTZ was investigated since solid lipid carriers are known to exhibit the advantages of traditional colloidal carriers. The research undertaken in these studies aimed to investigate the feasibility of developing and manufacturing solid lipid microparticles (SLM), using a simple micro-emulsion technique, as a carrier for KTZ. Prior to pre-formulation, formulation development and optimization studies of KTZ-loaded SLM, it was necessary to develop and validate an analytical method for the in vitro quantitation and characterization of KTZ in aqueous dispersions of SLM during development and assessment studies. An accurate, precise, specific and sensitive reversed-phase high performance liquid chromatographic (RP-HPLC) method coupled with UV detection at 206 nm was developed, optimized and validated for the analysis of KTZ in formulations. Formulation development studies were preceded by solubility studies of KTZ in different lipids. Labrafil® M2130 CS was found to exhibit the best solubilising potential for KTZ. Pre-formulation studies were also designed to determine the polymorphic behavior and the crystallinity of KTZ and Labrafil® M2130 CS that was used for subsequent manufacture of the solid lipid carriers. DSC and FTIR studies revealed that there were no changes in the crystallinity of KTZ or Labrafil® M2130 CS following exposure to a temperature of 60°C for 1 hour. In addition the potential for physicochemical interaction of KTZ with the lipid Labrafil® M2130 CS was investigated using DSC and FTIR and the results revealed that KTZ was molecularly dispersed in Labrafil® M2130 CS and that it is unlikely that KTZ would interact with the lipid. It was therefore established that KTZ and Labrafil® M2130 CS were thermo-stable at a temperature of 60°C and thus a micro-emulsion technique could be used to manufacture the KTZ-loaded SLM. Drug-free and KTZ-loaded SLM were prepared using a modified micro-emulsion technique that required the use of an Ultra-Turrax® homogenizer set at 24 000 rpm for 5 minutes followed by the use of the Erweka GmbH homogenizer. SLM were characterized in terms of particle size (PS), zeta potential (ZP), shape and surface morphology using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). In addition drug loading capacity (DLC) and encapsulation efficiency (EE) of SLM for KTZ were assessed using RP-HPLC. Formulation development and optimization studies of KTZ-loaded SLM were initially aimed at selecting an emulsifying system that was able to stabilize the SLM in an aqueous dispersion. Successful formulations were selected based on their ability to remain physically stable on the day of manufacture. Pluronic® F68 used in combination with Lutrol® E40, Soluphor® P, Soluplus® produced unstable dispersions on the day of manufacture and these combinations were not investigated further. However, the formulation of a stable KTZ-loaded SLM dispersion was accomplished by use of a combination of Pluronic® F68, Tween 80 and sodium cholate as the surfactant system. Increasing amounts of Labrafil® M2130 CS resulted in the production of particles with low DLC and EE, a large PS and a relatively unchanged ZP. An optimum concentration of 10% w/v Labrafil® M2130 CS was selected to manufacture the KTZ-loaded SLM. Studies to determine the influence of KTZ loading on the quality of SLM revealed that concentrations of KTZ > 5% w/v led to a reduction in DLC and EE and an increase in PS with minimal impact on the ZP. Stability studies conducted at 25°C/65% RH and 40°C/75% RH for up to 30 days following manufacture revealed that batch SLM 15 manufactured using 10% w/v Labrafil® M2130 CS, 5% w/v KTZ and a combination of 4% w/v Pluronic® F-68, 2% w/v Tween 80 and 1% w/v sodium cholate produced the most stable dosage form when stored at 25°C/65% RH for up to 30 days. However, storage at 40°C/75% RH resulted in instability of the formulation. An aqueous dispersion of KTZ-loaded SLM has been developed and assessed and may offer an alternative to extemporaneous preparations used for KTZ therapy in paediatric and immuno-compromised patients.
- Full Text:
- Date Issued: 2015
An investigation into the signals leakage from a smartcard based on different runtime code
- Frieslaar, Ibraheem, Irwin, Barry V W
- Authors: Frieslaar, Ibraheem , Irwin, Barry V W
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427845 , vital:72466 , https://www.researchgate.net/profile/Ibraheem-Fries-laar/publication/307918229_An_investigation_into_the_signals_leakage_from_a_smartcard_based_on_different_runtime_code/links/57d1996008ae0c0081e04fd5/An-investigation-into-the-signals-leakage-from-a-smartcard-based-on-different-runtime-code.pdf
- Description: This paper investigates the power leakage of a smartcard. It is intended to answer two vital questions: what information is leaked out when different characters are used as output; and does the length of the output affect the amount of the information leaked. The investigation determines that as the length of the output is increased more bus lines are switched from a precharge state to a high state. This is related to the output array in the code increasing its length. Furthermore, this work shows that the output for different characters generates a different pattern. This is due to the fact that various characters needs different amount of bytes to be executed since they have different binary value. Additionally, the information leaked out can be directly linked to the smartcard’s interpreter.
- Full Text:
- Date Issued: 2015
- Authors: Frieslaar, Ibraheem , Irwin, Barry V W
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427845 , vital:72466 , https://www.researchgate.net/profile/Ibraheem-Fries-laar/publication/307918229_An_investigation_into_the_signals_leakage_from_a_smartcard_based_on_different_runtime_code/links/57d1996008ae0c0081e04fd5/An-investigation-into-the-signals-leakage-from-a-smartcard-based-on-different-runtime-code.pdf
- Description: This paper investigates the power leakage of a smartcard. It is intended to answer two vital questions: what information is leaked out when different characters are used as output; and does the length of the output affect the amount of the information leaked. The investigation determines that as the length of the output is increased more bus lines are switched from a precharge state to a high state. This is related to the output array in the code increasing its length. Furthermore, this work shows that the output for different characters generates a different pattern. This is due to the fact that various characters needs different amount of bytes to be executed since they have different binary value. Additionally, the information leaked out can be directly linked to the smartcard’s interpreter.
- Full Text:
- Date Issued: 2015
An investigation of source rocks and depositional environments on acid mine drainage in South African coal mines: a comparison of the main Karoo basin and sub-basins.
- Authors: Ncube, Lindani
- Date: 2015
- Subjects: Mine drainage -- Environmental aspects -- South Africa , Coal mines and mining -- Environmental aspects -- South Africa , Acid mine drainage -- Environmental aspects -- South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/19556 , vital:43139
- Description: The coal deposits have been and continue to be the primary source of energy in South Africa. The continuous use of coal presents many challenges that includes genesis of acid mine drainage (AMD) which is as a result of the oxidation of predominant pyrite (FeS2) and other sulphides. The aim of this study was to investigate the role of source rocks and their depositional environments on AMD generation in South African coal mine environments. Five collieries from five coalfields were selected as case studies: Brandspruit in the Highveld, Vaalkrantz in the Vryheid, the Elitheni in the Molteno-Indwe, the Arnot in the Witbank and the Malatleng Exploration Project in the Waterberg Coalfields. Brandspruit, Vaalkrantz and Elitheni Collieries are located in the Main Karoo Basin, while the Witbank and the Waterberg Coalfields are located in Sub-Basins. The study investigated a variety of indices such as palaeo-depositional environments, mineral assemblages, geochemical signatures, water quality parameters, acid base accounting (ABA) and water leach tests for the coal and associated non-coal strata. An effort was made to establish the relationship between the mineralogy of the studied lithologies and the associated water quality. The study resulted in delineation of detrital and diagenetic rock components and interpretation of source area of rock types and the origin and timing of diagenetic alterations. Sandstone units are prevalent, except in the Waterberg Coalfield where mudstones are prevalent. Classifications of the mineralogical composition with descriptive adjectives yield the rock names arkose to sub-arkose categories in the Main Karoo Basin, and sub-arenites to quartz arenites in the Sub-Basins with the sandstones of recycled origin. Further, the sandstones of the Main Karoo Basin are of mixed provenance whilst those of Sub-Basins represent cratonic interior provenance. Sandstone from the Main Karoo Basin generally exhibit high concentrations of feldspars, which favour either high relief, arid or arctic climates with less chemical weathering at the source area. The presence of glauconite in sediments of the Main Karoo Basin attests to a marine continental shelf depositional environment. Sediments of the Main Karoo Basin have high contents of tadpole-shaped pyrite in coal and non-coal strata as compared to sediments of the Sub-Basins. The observed pyrite is ascribed to early diagenetic origin, and is closely related to the generation of acid mining drainage. The sediments have experienced an involved sequence of diagenetic alterations. The alterations considered to be typical for sandstones in the Main Karoo Basin are calcite cementation, feldspar dissolution, kaolinite infilling, pyrite grain coatings, albitization and pressure solution; whereas, quartz overgrowth and clay matrix filling are characteristics of sediments of Sub-Basins. The sequence and distribution of these alterations are related to the source mineral composition, depositional environment, stratigraphic relationships and burial history of the sediments. A direct link exists among the depositional environments, the mineral assemblages and the geochemical compositions of the lithologies. SiO2 is the dominant major oxide and is abundant in coals from coalfields located in the Sub-Basins. Si, Al, Fe, Ca, S, Mg, K and Na show strong association with their discrete minerals. The sandstones are substantially enriched in elements that are chemically immobile and associated with terrigenous influx, such as SiO2, Al2O3, and TiO2. The observed high contents of SiO2 are probably due to source rocks and silicification. SiO2, Al2O3 and TiO2 are related to clay and heavy minerals, with elevated Fe2O3 (Total) content in sediments of the Main Karoo Basin ascribed to sulphidization. Sediments from the Main Karoo Basin are enriched in both Na2O and K2O due to albitization and muscovitization. Substantial concentrations of Ba, Rb and Zr are in accordance to the high amount of phyllosilicates and heavy minerals. Muscovitization contributes to the correlation of Rb and Ba with K2O. The shales are substantially depleted in SiO2, CaO, MgO, Na2O, K2O, TiO2 and Fe2O3 due to weathering and diagenetic alteration, but are enriched in Al2O3 and P2O5. The ABA test clearly indicates that sandstones from the Main Karoo Basin have a potential of generating AMD as they contain sufficient pyrite to generate acid, with the final pH values of the samples turning acidic upon complete oxidation of pyrite. On the contrary, sediments of SubBasins contain sufficient calcite that serves to limit the amount of acid generation. Both sandstone and coal from collieries representing the Main Karoo Basin are characterised by elevated contents of S percent in comparison to coal from collieries representing the Sub-Basins. In general, the quality of water is as a result of a combination of complex geochemical interactions that involves various ions from different sources. Water leaching test shows that the leachates have varied chemical compositions with pH values in the range of 4.5-9 for the sandstone, and 2– 8.9 for the coal leachates. Variations in the pH values are attributed to regional phenomena controlled by the mineralogical and hydrological environments. Furthermore, the variation in pH is ascribed to the presence of acid forming pyrite and acid neutralizing carbonate minerals that are highly reactive in the mining environment. Elements Na, Ca, Mg and K occur in non-compliant concentrations in both coal and non-coal leachates indicating their abundance in all of the lithologies. Na enrichment in the lithologies is associated with albite, clay minerals and Al-Ksulphate coatings. Elements Fe, Al, Cd and Pb are easily leached from the lithologies. According to the equilibrium model, gibbsite, cuprite, diaspore and boehmite are the supersaturated minerals in the lithologies. Influencing factors such as the mineralogical composition of rocks are reflected in the wide variation of pH, TDS, EC and the ion concentrations of the studied water samples. The pH of the studied areas is neutral to alkaline. High levels of TDS and EC are observed in the Brandspruit Colliery, which is due to dissolution of soluble salts from the rock sequence that the water passes through. The anion chemistry shows the dominance of SO4 2- in the surface and groundwater of Brandspruit, Vaalkrantz and Elitheni Collieries, whereas HCO3 - dominates in the Arnot Colliery. SO4 2- is ascribed to the oxidative weathering of pyrites. Cldominates in groundwater from the Arnot Colliery and the Waterberg Coalfield. The cation chemistry is dominated by Na+ in the surface and groundwater of the Brandspruit, Vaalkrantz and Elitheni Collieries. Mg2+ dominates in groundwater from the Arnot Colliery, while K+ dominates in the Waterberg Coalfield. Fe is highly enriched in water from the Brandspruit Colliery, and is linked to the oxidation of pyrite. Carbonates are the supersaturated minerals in the Sub-Basins whilst sulphates are supersaturated in the Main Karoo Basin. The research shows that variations in regional mineral distribution is a result of a palaeo-deposition environment that was of marine nature for the coal sequence in the Main Karoo Basin and of fresh water for the coal sequence in Sub-Basins. A direct link therefore exists between depositional environments, mineral assemblages and whole rock geochemistry. It can be concluded that AMD is directly linked to pyrite and other sulphides, the coal mines located in the Main Karoo Basin have the possibility to deteriorate surface- and ground-water quality and to generate AMD during the mining processes; coal miners need to seriously consider applying environmental protection measures when mining coal in the Main Karoo Basin. Whereas, coal mining in the Sub-Basins has low possibility of generating AMD and pollution. , Thesis (PhD) (Geology) -- University of Fort Hare, 2015
- Full Text:
- Date Issued: 2015
- Authors: Ncube, Lindani
- Date: 2015
- Subjects: Mine drainage -- Environmental aspects -- South Africa , Coal mines and mining -- Environmental aspects -- South Africa , Acid mine drainage -- Environmental aspects -- South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/19556 , vital:43139
- Description: The coal deposits have been and continue to be the primary source of energy in South Africa. The continuous use of coal presents many challenges that includes genesis of acid mine drainage (AMD) which is as a result of the oxidation of predominant pyrite (FeS2) and other sulphides. The aim of this study was to investigate the role of source rocks and their depositional environments on AMD generation in South African coal mine environments. Five collieries from five coalfields were selected as case studies: Brandspruit in the Highveld, Vaalkrantz in the Vryheid, the Elitheni in the Molteno-Indwe, the Arnot in the Witbank and the Malatleng Exploration Project in the Waterberg Coalfields. Brandspruit, Vaalkrantz and Elitheni Collieries are located in the Main Karoo Basin, while the Witbank and the Waterberg Coalfields are located in Sub-Basins. The study investigated a variety of indices such as palaeo-depositional environments, mineral assemblages, geochemical signatures, water quality parameters, acid base accounting (ABA) and water leach tests for the coal and associated non-coal strata. An effort was made to establish the relationship between the mineralogy of the studied lithologies and the associated water quality. The study resulted in delineation of detrital and diagenetic rock components and interpretation of source area of rock types and the origin and timing of diagenetic alterations. Sandstone units are prevalent, except in the Waterberg Coalfield where mudstones are prevalent. Classifications of the mineralogical composition with descriptive adjectives yield the rock names arkose to sub-arkose categories in the Main Karoo Basin, and sub-arenites to quartz arenites in the Sub-Basins with the sandstones of recycled origin. Further, the sandstones of the Main Karoo Basin are of mixed provenance whilst those of Sub-Basins represent cratonic interior provenance. Sandstone from the Main Karoo Basin generally exhibit high concentrations of feldspars, which favour either high relief, arid or arctic climates with less chemical weathering at the source area. The presence of glauconite in sediments of the Main Karoo Basin attests to a marine continental shelf depositional environment. Sediments of the Main Karoo Basin have high contents of tadpole-shaped pyrite in coal and non-coal strata as compared to sediments of the Sub-Basins. The observed pyrite is ascribed to early diagenetic origin, and is closely related to the generation of acid mining drainage. The sediments have experienced an involved sequence of diagenetic alterations. The alterations considered to be typical for sandstones in the Main Karoo Basin are calcite cementation, feldspar dissolution, kaolinite infilling, pyrite grain coatings, albitization and pressure solution; whereas, quartz overgrowth and clay matrix filling are characteristics of sediments of Sub-Basins. The sequence and distribution of these alterations are related to the source mineral composition, depositional environment, stratigraphic relationships and burial history of the sediments. A direct link exists among the depositional environments, the mineral assemblages and the geochemical compositions of the lithologies. SiO2 is the dominant major oxide and is abundant in coals from coalfields located in the Sub-Basins. Si, Al, Fe, Ca, S, Mg, K and Na show strong association with their discrete minerals. The sandstones are substantially enriched in elements that are chemically immobile and associated with terrigenous influx, such as SiO2, Al2O3, and TiO2. The observed high contents of SiO2 are probably due to source rocks and silicification. SiO2, Al2O3 and TiO2 are related to clay and heavy minerals, with elevated Fe2O3 (Total) content in sediments of the Main Karoo Basin ascribed to sulphidization. Sediments from the Main Karoo Basin are enriched in both Na2O and K2O due to albitization and muscovitization. Substantial concentrations of Ba, Rb and Zr are in accordance to the high amount of phyllosilicates and heavy minerals. Muscovitization contributes to the correlation of Rb and Ba with K2O. The shales are substantially depleted in SiO2, CaO, MgO, Na2O, K2O, TiO2 and Fe2O3 due to weathering and diagenetic alteration, but are enriched in Al2O3 and P2O5. The ABA test clearly indicates that sandstones from the Main Karoo Basin have a potential of generating AMD as they contain sufficient pyrite to generate acid, with the final pH values of the samples turning acidic upon complete oxidation of pyrite. On the contrary, sediments of SubBasins contain sufficient calcite that serves to limit the amount of acid generation. Both sandstone and coal from collieries representing the Main Karoo Basin are characterised by elevated contents of S percent in comparison to coal from collieries representing the Sub-Basins. In general, the quality of water is as a result of a combination of complex geochemical interactions that involves various ions from different sources. Water leaching test shows that the leachates have varied chemical compositions with pH values in the range of 4.5-9 for the sandstone, and 2– 8.9 for the coal leachates. Variations in the pH values are attributed to regional phenomena controlled by the mineralogical and hydrological environments. Furthermore, the variation in pH is ascribed to the presence of acid forming pyrite and acid neutralizing carbonate minerals that are highly reactive in the mining environment. Elements Na, Ca, Mg and K occur in non-compliant concentrations in both coal and non-coal leachates indicating their abundance in all of the lithologies. Na enrichment in the lithologies is associated with albite, clay minerals and Al-Ksulphate coatings. Elements Fe, Al, Cd and Pb are easily leached from the lithologies. According to the equilibrium model, gibbsite, cuprite, diaspore and boehmite are the supersaturated minerals in the lithologies. Influencing factors such as the mineralogical composition of rocks are reflected in the wide variation of pH, TDS, EC and the ion concentrations of the studied water samples. The pH of the studied areas is neutral to alkaline. High levels of TDS and EC are observed in the Brandspruit Colliery, which is due to dissolution of soluble salts from the rock sequence that the water passes through. The anion chemistry shows the dominance of SO4 2- in the surface and groundwater of Brandspruit, Vaalkrantz and Elitheni Collieries, whereas HCO3 - dominates in the Arnot Colliery. SO4 2- is ascribed to the oxidative weathering of pyrites. Cldominates in groundwater from the Arnot Colliery and the Waterberg Coalfield. The cation chemistry is dominated by Na+ in the surface and groundwater of the Brandspruit, Vaalkrantz and Elitheni Collieries. Mg2+ dominates in groundwater from the Arnot Colliery, while K+ dominates in the Waterberg Coalfield. Fe is highly enriched in water from the Brandspruit Colliery, and is linked to the oxidation of pyrite. Carbonates are the supersaturated minerals in the Sub-Basins whilst sulphates are supersaturated in the Main Karoo Basin. The research shows that variations in regional mineral distribution is a result of a palaeo-deposition environment that was of marine nature for the coal sequence in the Main Karoo Basin and of fresh water for the coal sequence in Sub-Basins. A direct link therefore exists between depositional environments, mineral assemblages and whole rock geochemistry. It can be concluded that AMD is directly linked to pyrite and other sulphides, the coal mines located in the Main Karoo Basin have the possibility to deteriorate surface- and ground-water quality and to generate AMD during the mining processes; coal miners need to seriously consider applying environmental protection measures when mining coal in the Main Karoo Basin. Whereas, coal mining in the Sub-Basins has low possibility of generating AMD and pollution. , Thesis (PhD) (Geology) -- University of Fort Hare, 2015
- Full Text:
- Date Issued: 2015