Mediating and examining expansive learning in the context of multidimensional complexities affecting household food security activity systems in Nyanyadzi Irrigation Scheme in the Manicaland Province of Zimbabwe
- Authors: Mukwambo, Robson
- Date: 2021-10-29
- Subjects: Active learning Zimbabwe Chimanimani District , Food security Zimbabwe Chimanimani District , Sustainable agriculture Zimbabwe Chimanimani District , Irrigation farming Zimbabwe Chimanimani District , Qualitative research , Cultural-historical activity theory (CHAT) , Nyanyadzi Irrigation Scheme
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/192712 , vital:45253 , 10.21504/10962/192712
- Description: The study sought to mediate and examine expansive learning in the context of multidimensional complexities affecting household food security activity systems in Nyanyadzi Irrigation Scheme in Ward 8 of Chimanimani District in the Manicaland province of Zimbabwe. Therefore, the main foci of the study were to investigate how multidimensional complexities have come to be the way they are (historicizing) and how they enable or constrain learning of household food production. The study utilized Cultural Historical Activity Theory and the Expansive Learning Cycle (Engeström & Sannino, 2010) to examine and mediate collective learning in response to the multidimensional complexities and also to contribute to transforming the farmers’ activity systems towards more sustainable practices to ensure household food security. The study used a qualitative research approach, utilizing an insider formative intervention approach in a case study design in which Nyanyadzi irrigation scheme was the case study. I have adopted the insider formative interventionist role as a 3rd generation farmer, born and bred in Nyanyadzi area, and my family has been involved in the Nyanyadzi irrigation scheme for three generations. I see this as synergistic with the need for deep cultural understanding in CHAT research. However, this role also provided challenges for me to maintain a rigorous approach to the research in which I also reflexively review my own role and influence in the research process. Following CHAT expansive learning methodological guidance, data was generated through fifteen (15) face to face interviews with three generations of farmers in the scheme (historical ethnographic data); four focus group discussions (contemporary ethnographic data) and eight (8) sessions in a three (3) day change laboratory workshop (expansive learning data). Double stimulation and ‘mirror’ data was used to surface and prioritise responses to contradictions in the Change Laboratory Workshops (CLW), which is a methodology developed in and for CHAT research (ibid). The data was analysed using both inductive and abductive approaches and were conducted in a three-phased process focusing firstly on the history of the object, followed by current perspectives on the object of activity and lastly on transformations emerging in the object of activity via the expansive learning process. Cultural Historical Activity Theoretical tools informed activity system analysis and analysis of the history of the object and emerging contradictions; and the expansive learning cycle (ELP) process framework associated with and emergent from CHAT was used to analyse the emergence of transformative agency and expansion of the object. Four levels of contradictions were used to describe and explain the emergent contradictions namely, primary, secondary, tertiary and quaternary contradictions and are presented in this sequence as catalytic opportunities for expansive learning as proposed in CHAT. In addition, the four types of discursive manifestations of contradictions namely, dilemma, conflict, critical conflict and double bind were used to describe and explain the manifestations of contradictions in this study and their role in catalysing transformative agency. The concept of linguistic cues for discursive manifestations of contradictions was adopted and employed in the preliminary data analysis phase. In addition, the transformative agency expressions and zone of proximal development (ZPD) concept was applied in and to the CLW data to examine the learning pathways and to co-develop and expand farmers’ and other stakeholders’ transformative agency and ZPD respectively. I found myself as formative insider researcher having to take on a strong role as co-engaged researcher / participant in the irrigation scheme expansive learning process. The study concluded that the farmers’ activity system is the central activity system and it interacts with other activity systems on a partially shared object “improved crop production and marketing under irrigation scheme”. Through interactions with other neighbouring activity systems, the farmers have faced multidimensional complexities that constrain their ability to fully realise their object. These multidimensional complexities manifest in three critical contradictions as a critical conflict in leadership and management crisis; a dilemma and double bind in a lack of farmer education and training; and lastly, a dilemma and double bind in poor crop marketing. These multidimensional complexities have a historical account and they have evolved in complexity over time and I argue in the thesis that, a careful cultural-historicity of the object of activity and mediation of the situated learning can help to collectively come up with solutions to these multidimensional complexities. The study further concluded that despite these multidimensional complexities in the scheme, learning has been taking place and such learning was sometimes mediated through demonstrations as “learning by doing,” “seeing is believing” and the “winners and losers” concept. Furthermore, through the CLW process the farmers and other stakeholders’ cognitive horizons were expanded by the mirror data and double stimulation processes, and the expansive learning process developed their individual and collective transformative agency pathways and expanded their collective zone of proximal development. In this study I argue that there has been little said about collective learning in irrigation schemes and given the dearth of detail on such learning, it seems that this learning is either going unnoticed or is ignored. Hence, I further argued that the multidimensional complexities in irrigation schemes are both a stimulant for learning and provide a space (object) for collective learning, as was also shown by Baloi (2016). The study also shows that the collective learning potential in these irrigation schemes can be pro-actively mediated via expansive learning formative interventions in support of improved crop production and marketing for produce developed under irrigation in irrigation schemes such as the Nyanyadzi Irrigation scheme. Lastly, being an insider formative interventionist researcher in this study, with intergenerational engagement and perspective on the history of the object and integrational engagement with the transforming object, I became part of the intergenerational transformation of the irrigation scheme’s object. The intergenerational co-construction of the history of the object, coupled with the insider formative interventionist researcher approach opened up and allowed me as a current generation agent or actor to develop an in-depth understanding of the multidimensional nature and historicity of the object. This was crucial for opening up the transformative agency pathways. It also produced a responsibility for me as an insider formative interventionist researcher to carry the summative findings of the study back into the social context to widen the engagement and mediation of the transformation needed in the community. Overall not only does the study offer an intergenerational perspective on multidimensional complexities of the object and how this can generatively be mobilised via expansive learning into emerging transformative learning agency pathways, but it also offers a new vantage point on the role of the insider formative interventionist researcher. Through this, the study offers insight into how we as third generation members of the community can be brought closer to our communities through the application of our skills, thereby also offering a new type of engaged and rigorously framed and executed research with roots in our communities. As shown in this study, not only does this expand the knowledge and experience of those we engage with, but it also expands our own knowledge and expertise in order to be more able to contribute to both the challenges of our own communities but also that of other communities and situations similar to ours, and beyond these bounded contexts. The study’s contribution is both practical, but also methodological from this vantage point, especially in an African context where there is much critique of ‘outsider research’, yet little pro-active articulation of what insider (in this case, formative intervention) research may look like. , Thesis (PhD) -- Faculty of Education, Education, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Mukwambo, Robson
- Date: 2021-10-29
- Subjects: Active learning Zimbabwe Chimanimani District , Food security Zimbabwe Chimanimani District , Sustainable agriculture Zimbabwe Chimanimani District , Irrigation farming Zimbabwe Chimanimani District , Qualitative research , Cultural-historical activity theory (CHAT) , Nyanyadzi Irrigation Scheme
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/192712 , vital:45253 , 10.21504/10962/192712
- Description: The study sought to mediate and examine expansive learning in the context of multidimensional complexities affecting household food security activity systems in Nyanyadzi Irrigation Scheme in Ward 8 of Chimanimani District in the Manicaland province of Zimbabwe. Therefore, the main foci of the study were to investigate how multidimensional complexities have come to be the way they are (historicizing) and how they enable or constrain learning of household food production. The study utilized Cultural Historical Activity Theory and the Expansive Learning Cycle (Engeström & Sannino, 2010) to examine and mediate collective learning in response to the multidimensional complexities and also to contribute to transforming the farmers’ activity systems towards more sustainable practices to ensure household food security. The study used a qualitative research approach, utilizing an insider formative intervention approach in a case study design in which Nyanyadzi irrigation scheme was the case study. I have adopted the insider formative interventionist role as a 3rd generation farmer, born and bred in Nyanyadzi area, and my family has been involved in the Nyanyadzi irrigation scheme for three generations. I see this as synergistic with the need for deep cultural understanding in CHAT research. However, this role also provided challenges for me to maintain a rigorous approach to the research in which I also reflexively review my own role and influence in the research process. Following CHAT expansive learning methodological guidance, data was generated through fifteen (15) face to face interviews with three generations of farmers in the scheme (historical ethnographic data); four focus group discussions (contemporary ethnographic data) and eight (8) sessions in a three (3) day change laboratory workshop (expansive learning data). Double stimulation and ‘mirror’ data was used to surface and prioritise responses to contradictions in the Change Laboratory Workshops (CLW), which is a methodology developed in and for CHAT research (ibid). The data was analysed using both inductive and abductive approaches and were conducted in a three-phased process focusing firstly on the history of the object, followed by current perspectives on the object of activity and lastly on transformations emerging in the object of activity via the expansive learning process. Cultural Historical Activity Theoretical tools informed activity system analysis and analysis of the history of the object and emerging contradictions; and the expansive learning cycle (ELP) process framework associated with and emergent from CHAT was used to analyse the emergence of transformative agency and expansion of the object. Four levels of contradictions were used to describe and explain the emergent contradictions namely, primary, secondary, tertiary and quaternary contradictions and are presented in this sequence as catalytic opportunities for expansive learning as proposed in CHAT. In addition, the four types of discursive manifestations of contradictions namely, dilemma, conflict, critical conflict and double bind were used to describe and explain the manifestations of contradictions in this study and their role in catalysing transformative agency. The concept of linguistic cues for discursive manifestations of contradictions was adopted and employed in the preliminary data analysis phase. In addition, the transformative agency expressions and zone of proximal development (ZPD) concept was applied in and to the CLW data to examine the learning pathways and to co-develop and expand farmers’ and other stakeholders’ transformative agency and ZPD respectively. I found myself as formative insider researcher having to take on a strong role as co-engaged researcher / participant in the irrigation scheme expansive learning process. The study concluded that the farmers’ activity system is the central activity system and it interacts with other activity systems on a partially shared object “improved crop production and marketing under irrigation scheme”. Through interactions with other neighbouring activity systems, the farmers have faced multidimensional complexities that constrain their ability to fully realise their object. These multidimensional complexities manifest in three critical contradictions as a critical conflict in leadership and management crisis; a dilemma and double bind in a lack of farmer education and training; and lastly, a dilemma and double bind in poor crop marketing. These multidimensional complexities have a historical account and they have evolved in complexity over time and I argue in the thesis that, a careful cultural-historicity of the object of activity and mediation of the situated learning can help to collectively come up with solutions to these multidimensional complexities. The study further concluded that despite these multidimensional complexities in the scheme, learning has been taking place and such learning was sometimes mediated through demonstrations as “learning by doing,” “seeing is believing” and the “winners and losers” concept. Furthermore, through the CLW process the farmers and other stakeholders’ cognitive horizons were expanded by the mirror data and double stimulation processes, and the expansive learning process developed their individual and collective transformative agency pathways and expanded their collective zone of proximal development. In this study I argue that there has been little said about collective learning in irrigation schemes and given the dearth of detail on such learning, it seems that this learning is either going unnoticed or is ignored. Hence, I further argued that the multidimensional complexities in irrigation schemes are both a stimulant for learning and provide a space (object) for collective learning, as was also shown by Baloi (2016). The study also shows that the collective learning potential in these irrigation schemes can be pro-actively mediated via expansive learning formative interventions in support of improved crop production and marketing for produce developed under irrigation in irrigation schemes such as the Nyanyadzi Irrigation scheme. Lastly, being an insider formative interventionist researcher in this study, with intergenerational engagement and perspective on the history of the object and integrational engagement with the transforming object, I became part of the intergenerational transformation of the irrigation scheme’s object. The intergenerational co-construction of the history of the object, coupled with the insider formative interventionist researcher approach opened up and allowed me as a current generation agent or actor to develop an in-depth understanding of the multidimensional nature and historicity of the object. This was crucial for opening up the transformative agency pathways. It also produced a responsibility for me as an insider formative interventionist researcher to carry the summative findings of the study back into the social context to widen the engagement and mediation of the transformation needed in the community. Overall not only does the study offer an intergenerational perspective on multidimensional complexities of the object and how this can generatively be mobilised via expansive learning into emerging transformative learning agency pathways, but it also offers a new vantage point on the role of the insider formative interventionist researcher. Through this, the study offers insight into how we as third generation members of the community can be brought closer to our communities through the application of our skills, thereby also offering a new type of engaged and rigorously framed and executed research with roots in our communities. As shown in this study, not only does this expand the knowledge and experience of those we engage with, but it also expands our own knowledge and expertise in order to be more able to contribute to both the challenges of our own communities but also that of other communities and situations similar to ours, and beyond these bounded contexts. The study’s contribution is both practical, but also methodological from this vantage point, especially in an African context where there is much critique of ‘outsider research’, yet little pro-active articulation of what insider (in this case, formative intervention) research may look like. , Thesis (PhD) -- Faculty of Education, Education, 2021
- Full Text:
- Date Issued: 2021-10-29
Mental Health Professionals’ Gender-Sensitivity and Responsiveness to the Genderqueer population in Substance Use Disorder Treatment: A Systematic Review
- Authors: Maseko, Moosa Lorenzo
- Date: 2021-10-29
- Subjects: Gender nonconformity , Substance abuse , Mental health personnel , Gender-nonconforming people Counseling of , Discrimination in mental health services , Joanna Briggs Institute’s systematic review method
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/190133 , vital:44966
- Description: Background: The prevalence of Substance Use Disorders (SUDs) amongst the genderqueer population is a huge concern in the public mental health system. The genderqueer population’s help-seeking barriers have been attributed to SUD treatment centre’s questionable ability to be responsive to the unique mental health needs of genderqueer individuals. Aim: The aim of this study is to conduct a systematic review on mental healthcare workers‟ responsiveness and gender-sensitivity towards the genderqueer population in SUD treatment centres. Methods: Employing the Joanna Briggs Institute’s (JBIs) systematic review method, 25 qualitative articles were included in this study. A thematic analysis was used to examine the data. Results: The analysis revealed that SUD treatment centres are experienced as discriminatory and unreceptive by the genderqueer population due to several barriers. The barriers identified were structural, financial, personal, cultural and the use of a heterosexual framework to treat SUD which led to abuse, isolation, and stigma. Mental healthcare providers lack skills in working with genderqueer individuals as well as a lack of knowledge on genderqueer related needs. Lack of gender sensitivity affects genderqueer individuals in accessing SUD treatment centres and the progress they make. This magnified the need and importance of specialised gender-responsive and gender-sensitive training in working with genderqueer individuals. Twelve interventions to address the areas of difficulty were identified. , Thesis (MA) -- Faculty of Humanities, Psychology, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Maseko, Moosa Lorenzo
- Date: 2021-10-29
- Subjects: Gender nonconformity , Substance abuse , Mental health personnel , Gender-nonconforming people Counseling of , Discrimination in mental health services , Joanna Briggs Institute’s systematic review method
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/190133 , vital:44966
- Description: Background: The prevalence of Substance Use Disorders (SUDs) amongst the genderqueer population is a huge concern in the public mental health system. The genderqueer population’s help-seeking barriers have been attributed to SUD treatment centre’s questionable ability to be responsive to the unique mental health needs of genderqueer individuals. Aim: The aim of this study is to conduct a systematic review on mental healthcare workers‟ responsiveness and gender-sensitivity towards the genderqueer population in SUD treatment centres. Methods: Employing the Joanna Briggs Institute’s (JBIs) systematic review method, 25 qualitative articles were included in this study. A thematic analysis was used to examine the data. Results: The analysis revealed that SUD treatment centres are experienced as discriminatory and unreceptive by the genderqueer population due to several barriers. The barriers identified were structural, financial, personal, cultural and the use of a heterosexual framework to treat SUD which led to abuse, isolation, and stigma. Mental healthcare providers lack skills in working with genderqueer individuals as well as a lack of knowledge on genderqueer related needs. Lack of gender sensitivity affects genderqueer individuals in accessing SUD treatment centres and the progress they make. This magnified the need and importance of specialised gender-responsive and gender-sensitive training in working with genderqueer individuals. Twelve interventions to address the areas of difficulty were identified. , Thesis (MA) -- Faculty of Humanities, Psychology, 2021
- Full Text:
- Date Issued: 2021-10-29
Microalgal-bacterial flocs and extracellular polymeric substances for optimum function of integrated algal pond systems
- Authors: Jimoh, Taobat Adekilekun
- Date: 2021-10-29
- Subjects: Flocculation , Extracellular polymeric substances , Water Purification , Sewage Purification Anaerobic treatment , Integrated algae pond systems (IAPS) , Microalgal-bacterial flocs
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/191214 , vital:45071 , 10.21504/10962/191214
- Description: Despite the dire state of sanitation infrastructures, water scarcity, and the dwindling reserve of natural resources due to ever-increasing population growth, implementation of a suitable technology that can provide a solution to all these issues continues to be ignored. The integrated algal pond system (IAPS) is a wastewater treatment technology that combines the processes of anaerobic digestion and photosynthetic oxygenation to achieve wastewater treatment and facilitate the recovery of treated water and resources in the form of biogas and microalgal-bacterial biomass. The natural process of bioflocculation through microalgal-bacterial mutualism and production of extracellular polymeric substances (EPS) in high rate algal oxidation ponds (HRAOPs) of an IAPS increases efficiency of wastewater treatment and potentially enhances harvestability and biomass recovery, which could contribute significantly to the successful establishment of a biorefinery. Using a 500 PE pilot-scale IAPS supplied domestic sewage coupled with laboratory experiments, this study investigated the importance and function of in situ EPS production and MaB-floc formation in HRAOP. A metagenomic study revealed the biological components of the biomass or mixed liquor suspended solids (MLSS) produced in HRAOP and showed that the suspended biomass is composed largely of eukaryotes that were dominated by the colonial microalgae Pseudopediastrum sp. and Desmodesmus sp., and a diverse range of prokaryotes including bacteria and cyanobacteria. Dominance, within the bacterial population, by a sulphur-oxidizing bacterium, Thiothrix which comprised up to 80% of the prokaryotes, coincided with a period of poor flocculation and was therefore rationalized to have contributed to bulking and poor biomass settleability. Otherwise, good flocs were formed in the MLSS with settleability up to 95% and, within 1 h. The formation of MaB-flocs appeared to be dependent on EPS concentration of the mixed liquor due to the observed positive correlation between soluble EPS (S-EPS), biomass concentration, and settleability. The contribution and role of MLSS components towards the formation and sustenance of MaB-flocs were further demonstrated in laboratory experiments using pure strains of microalgae, cyanobacteria, and bacteria. Results showed that pure cultures of dominant microalgae in MLSS, Pseudopediastrum sp. and Desmodesmus sp. achieved a rapid 92 and 75% settleability within 3 h. A self-flocculating filamentous cyanobacterium, Leptolyngbya strain ECCN 20BG was isolated, characterized, and shown to achieve 99% settleability within 5 min by forming large tightly aggregated flocs. In further experiments, this strain was found to improve the settleability of MLSS by an average of 20%. Bacterial strains identified as Bacillus strain ECCN 40b, Bacillus strain ECCN 41b, Planococcus strain ECCN 45b, and Exiguobacterium strain ECCN 46b were also observed to produce sticky EPS-like materials in pure cultures that could also contribute to the aggregation of cells in a mixed environment. Given these results, various factors and/or mechanisms that might enhance microbial aggregation and biomass recovery from HRAOP MLSS were identified in this study and include; (1) dominance by larger colonial microalgae prevents disintegration of MaB-flocs and enhances recovery of biomass from MLSS by gravity sedimentation, (2) presence of filamentous cyanobacteria species that can self-flocculate to form an interwoven network of filaments may play an important role in the structural stability and settleability of MaB-flocs in MLSS, and (3) production of EPS to form the matrix or scaffold whereon all microbial components aggregate to develop a microenvironment. Indeed, all forms of EPS, except for that produced by Bacillus strain ECCN 41b, showed bioflocculating property and were able to serve as flocculants for the recovery of Chlorella, an alga known for its poor settleability. A combination of biochemical analyses and FTIR spectroscopy revealed the importance of carbohydrate enrichment of these biopolymers. Carbohydrate concentration in all forms of EPS was between 12 and 41% suggesting that production of these compounds by microbes within the MLSS contributed to MaB-floc formation. EPS extracted from bulk MLSS and EPS produced by Bacillus strains possessed some surface-active properties that were comparable to Triton X-100, indicating potential application in bioremediation and recovery of oil from contaminated soil and water. In particular, EPS generated from Bacillus strain ECCN 41b displayed relatively distinct properties including the quantity produced (> 500 mg/L), increased viscosity, inability to flocculate microalgal cells, a rhamnolipid content of 32%, and a higher surface-activity. Based on these results, Bacillus strain ECCN 41b was rationalized to produce anionic EPS with potential application in metal or oil recovery. In addition to EPS production, the bacteria Planococcus strain ECCN 45b and Exiguobacterium strain ECCN 46b appeared pigmented. Based on partial characterization using UV/Vis spectrophotometry, thin-layer chromatography, FTIR, and NMR, the pigments produced by these two strains appeared to be identical and were tentatively identified as ketocarotenoids. This study successfully demonstrated the importance of EPS production and formation of MaB-flocs in the MLSS from HRAOP of an IAPS treating domestic sewage. It is evident that increased settleability of the biomass does contribute to the reported efficiency of wastewater treatment by IAPS and would reduce both total suspended solids (TSS) and chemical oxygen demand (COD). In addition, demonstration that this biomass contains products of value such as carotenoids and EPS with potential for commercial use strengthens the idea of using IAPS as a platform technology for innovation of the wastewater treatment process to a biorefinery. , Thesis (PhD) -- Faculty of Science, Institute for Environmental Biotechnology, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Jimoh, Taobat Adekilekun
- Date: 2021-10-29
- Subjects: Flocculation , Extracellular polymeric substances , Water Purification , Sewage Purification Anaerobic treatment , Integrated algae pond systems (IAPS) , Microalgal-bacterial flocs
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/191214 , vital:45071 , 10.21504/10962/191214
- Description: Despite the dire state of sanitation infrastructures, water scarcity, and the dwindling reserve of natural resources due to ever-increasing population growth, implementation of a suitable technology that can provide a solution to all these issues continues to be ignored. The integrated algal pond system (IAPS) is a wastewater treatment technology that combines the processes of anaerobic digestion and photosynthetic oxygenation to achieve wastewater treatment and facilitate the recovery of treated water and resources in the form of biogas and microalgal-bacterial biomass. The natural process of bioflocculation through microalgal-bacterial mutualism and production of extracellular polymeric substances (EPS) in high rate algal oxidation ponds (HRAOPs) of an IAPS increases efficiency of wastewater treatment and potentially enhances harvestability and biomass recovery, which could contribute significantly to the successful establishment of a biorefinery. Using a 500 PE pilot-scale IAPS supplied domestic sewage coupled with laboratory experiments, this study investigated the importance and function of in situ EPS production and MaB-floc formation in HRAOP. A metagenomic study revealed the biological components of the biomass or mixed liquor suspended solids (MLSS) produced in HRAOP and showed that the suspended biomass is composed largely of eukaryotes that were dominated by the colonial microalgae Pseudopediastrum sp. and Desmodesmus sp., and a diverse range of prokaryotes including bacteria and cyanobacteria. Dominance, within the bacterial population, by a sulphur-oxidizing bacterium, Thiothrix which comprised up to 80% of the prokaryotes, coincided with a period of poor flocculation and was therefore rationalized to have contributed to bulking and poor biomass settleability. Otherwise, good flocs were formed in the MLSS with settleability up to 95% and, within 1 h. The formation of MaB-flocs appeared to be dependent on EPS concentration of the mixed liquor due to the observed positive correlation between soluble EPS (S-EPS), biomass concentration, and settleability. The contribution and role of MLSS components towards the formation and sustenance of MaB-flocs were further demonstrated in laboratory experiments using pure strains of microalgae, cyanobacteria, and bacteria. Results showed that pure cultures of dominant microalgae in MLSS, Pseudopediastrum sp. and Desmodesmus sp. achieved a rapid 92 and 75% settleability within 3 h. A self-flocculating filamentous cyanobacterium, Leptolyngbya strain ECCN 20BG was isolated, characterized, and shown to achieve 99% settleability within 5 min by forming large tightly aggregated flocs. In further experiments, this strain was found to improve the settleability of MLSS by an average of 20%. Bacterial strains identified as Bacillus strain ECCN 40b, Bacillus strain ECCN 41b, Planococcus strain ECCN 45b, and Exiguobacterium strain ECCN 46b were also observed to produce sticky EPS-like materials in pure cultures that could also contribute to the aggregation of cells in a mixed environment. Given these results, various factors and/or mechanisms that might enhance microbial aggregation and biomass recovery from HRAOP MLSS were identified in this study and include; (1) dominance by larger colonial microalgae prevents disintegration of MaB-flocs and enhances recovery of biomass from MLSS by gravity sedimentation, (2) presence of filamentous cyanobacteria species that can self-flocculate to form an interwoven network of filaments may play an important role in the structural stability and settleability of MaB-flocs in MLSS, and (3) production of EPS to form the matrix or scaffold whereon all microbial components aggregate to develop a microenvironment. Indeed, all forms of EPS, except for that produced by Bacillus strain ECCN 41b, showed bioflocculating property and were able to serve as flocculants for the recovery of Chlorella, an alga known for its poor settleability. A combination of biochemical analyses and FTIR spectroscopy revealed the importance of carbohydrate enrichment of these biopolymers. Carbohydrate concentration in all forms of EPS was between 12 and 41% suggesting that production of these compounds by microbes within the MLSS contributed to MaB-floc formation. EPS extracted from bulk MLSS and EPS produced by Bacillus strains possessed some surface-active properties that were comparable to Triton X-100, indicating potential application in bioremediation and recovery of oil from contaminated soil and water. In particular, EPS generated from Bacillus strain ECCN 41b displayed relatively distinct properties including the quantity produced (> 500 mg/L), increased viscosity, inability to flocculate microalgal cells, a rhamnolipid content of 32%, and a higher surface-activity. Based on these results, Bacillus strain ECCN 41b was rationalized to produce anionic EPS with potential application in metal or oil recovery. In addition to EPS production, the bacteria Planococcus strain ECCN 45b and Exiguobacterium strain ECCN 46b appeared pigmented. Based on partial characterization using UV/Vis spectrophotometry, thin-layer chromatography, FTIR, and NMR, the pigments produced by these two strains appeared to be identical and were tentatively identified as ketocarotenoids. This study successfully demonstrated the importance of EPS production and formation of MaB-flocs in the MLSS from HRAOP of an IAPS treating domestic sewage. It is evident that increased settleability of the biomass does contribute to the reported efficiency of wastewater treatment by IAPS and would reduce both total suspended solids (TSS) and chemical oxygen demand (COD). In addition, demonstration that this biomass contains products of value such as carotenoids and EPS with potential for commercial use strengthens the idea of using IAPS as a platform technology for innovation of the wastewater treatment process to a biorefinery. , Thesis (PhD) -- Faculty of Science, Institute for Environmental Biotechnology, 2021
- Full Text:
- Date Issued: 2021-10-29
Mitigating salt accumulation in recycled brewery effluent through the integration of water treatment, agriculture and aquaculture
- Authors: Mabasa, Nyiko Charity
- Date: 2021-10-29
- Subjects: Brewery waste South Africa Eastern Cape , Recycling (Waste, etc.) South Africa Eastern Cape , Water reuse South Africa Eastern Cape , Irrigation South Africa Eastern Cape , Sewage Purification Anaerobic treatment , Constructed wetlands , Aquaculture
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/191126 , vital:45063 , 10.21504/10962/191126
- Description: Water scarcity in South Africa, and globally, presents challenges for industries. It is imperative to develop responsible water use, such as recycling and reusing wastewater from food processing industries such as breweries. The Ibhayi Brewery (SAB Ltd) employs a combination of sustainable treatment processes that include anaerobic digestion (AD), primary facultative ponds (PFP), high rate algal ponds (HRAP) and constructed wetlands (CW) to treat brewery effluent on an experimental scale. The constituent concentrations of these experimentally treated effluents are within the ranges prescribed by local regulations to allow for potential downstream use in agriculture and aquaculture. However, the sodium content in this treated effluent, which originates from upstream cleaning agents and pH control at the onsite effluent treatment facility, is a constraint to the downstream use of brewery effluent. This study addresses the salt problem, by investigating the potential of either reducing/eliminating salt addition at source, or developing alternative techniques for downstream agriculture to mitigate the effects of salt accumulation caused by irrigation with brewery effluent. Four salt-tolerant test crops; Swiss chard (Beta vulgaris), saltbush (Atriplex nummularia), Salicornia meyeriana and sorghum (Sorghum bicolor), grew efficiently in brewery effluent irrigated soils but did not stop sodium accumulation in the growth medium. Swiss chard had the best growth with a wet biomass accumulation of 8,173 g m-2, due to the plant’s ability to tolerate saline conditions and continuous cropping. Crop rotation, to limit effects of nutrient depletion in soil, had no significant effect on plant growth suggesting soils were adequately able to provide micro-nutrients in the short-term. Prolonged irrigation with brewery effluent can lead to sodium accumulation in the soil, which was successfully controlled through the addition of soil amendments (gypsum and Trichoderma cultures). These reduced soil sodium from a potentially limiting level of 1,398 mg L-1 to the acceptable levels of 240 mg L-1 and 353 mg L-1 respectively, mainly through leaching. However only Trichoderma improved Swiss chard production to 11,238 g m-2. While crop rotation in this work did not contribute to mitigating the problem of salt accumulation, soil amended with Trichoderma appears to be a potential solution when brewery effluent is reused in agriculture. In an alternative to soil cultivation, CWs were trialled with no significant differences in the sodium concentration of brewery effluent treated along a 15 m lateral flow CW, which could be attributed to evapotranspiration. This was notably accompanied by a desirable 95.21% decrease in ammonia from inlet to outlet resulting in significant improvement in water quality for reuse in aquaculture where ammonia levels are important limiting constraints. While CWs remain a suitable brewery effluent treatment solution, this technology requires additional modelling and optimisation in order to mitigate the problem of salt accumulation in the reuse of treated brewery effluent in agriculture and aquaculture. This research demonstrates the baseline information for such modelling and optimisation. African catfish (Clarias gariepinus) grew in CW treated brewery effluent; however, this growth was moderate at 0.92% bw day-1, whereas Mozambique tilapia (Oreochromis mossambicus) were shown to be unsuited to growth in this system and lost weight with an average specific growth rate (SGR) of -0.98% bw day-1; and both fish species presenting with health related concerns. Hardy fish species such as African catfish can be cultured in brewery effluent, but with risk involved. This was a preliminary study to develop parameters for future dimensional analysis modelling to allow optimisation of the CW, based on nutrient removal rates obtained which will allow for improved downstream aquaculture by reducing or eliminating risks presented in this study. This work has also contributed to a foundation for the development of guidelines that use a risk-based approach for water use in aquaculture. Alternatives to the current in place cleaning agents were considered to mitigate the effects of salt accumulation. Sodium is introduced into the effluent via the use of sodium hydroxide and sodium chlorite for cleaning and disinfection in the brewery, as well as through effluent pH adjustment in the AD plant. The widespread use of outdated legacy cleaning systems and pH adjustment regimes is entrenched in the brewery standard operating procedures (SOP). A cost-benefit analysis (CBA) demonstrated that a change of cleaning and disinfecting regimes to hydrogen peroxide in the brewery, and magnesium hydroxide pH adjustment in the effluent treatment plant addresses the sodium issue upstream in the brewery practically eliminating sodium from the effluent. In addition, a life cycle analysis (LCA) was carried out to assess the environmental impacts associated with the alternative cleaning and pH adjustment scenarios. The LCA showed that electricity consumption during use phase of the chemicals for respective purposes, as well as their production activities were major contributors to the significant environmental impact categories that were assessed. The cleaning scenario employing the use of hydrogen peroxide for both cleaning and disinfection was found to be the most environmentally sustainable. This was attributed to the reduced number of chemicals used compared to the other cleaning scenarios. Dolomitic lime was the pH adjustment alternative with the lowest average environmental impact; but, however, had a higher impact on freshwater eutrophication which is of major concern if the effluent will be reused for irrigation. Magnesium hydroxide was therefore considered to be the better option as a sodium hydroxide alternative for pH adjustment. This mitigates salt accumulation, making treated brewery effluent suitable for reuse in high value downstream agriculture and aquaculture, while employing more environmentally sustainable technologies. Notably, this converts brewery effluent from a financial liability to Ibhayi Brewery, into a product containing water and nutrients that generate income, improve food security, and can create employment in downstream agriculture and aquaculture in a sustainable manner. , Thesis (PhD) -- Faculty of Science, Ichthyology and Fisheries Science, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Mabasa, Nyiko Charity
- Date: 2021-10-29
- Subjects: Brewery waste South Africa Eastern Cape , Recycling (Waste, etc.) South Africa Eastern Cape , Water reuse South Africa Eastern Cape , Irrigation South Africa Eastern Cape , Sewage Purification Anaerobic treatment , Constructed wetlands , Aquaculture
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/191126 , vital:45063 , 10.21504/10962/191126
- Description: Water scarcity in South Africa, and globally, presents challenges for industries. It is imperative to develop responsible water use, such as recycling and reusing wastewater from food processing industries such as breweries. The Ibhayi Brewery (SAB Ltd) employs a combination of sustainable treatment processes that include anaerobic digestion (AD), primary facultative ponds (PFP), high rate algal ponds (HRAP) and constructed wetlands (CW) to treat brewery effluent on an experimental scale. The constituent concentrations of these experimentally treated effluents are within the ranges prescribed by local regulations to allow for potential downstream use in agriculture and aquaculture. However, the sodium content in this treated effluent, which originates from upstream cleaning agents and pH control at the onsite effluent treatment facility, is a constraint to the downstream use of brewery effluent. This study addresses the salt problem, by investigating the potential of either reducing/eliminating salt addition at source, or developing alternative techniques for downstream agriculture to mitigate the effects of salt accumulation caused by irrigation with brewery effluent. Four salt-tolerant test crops; Swiss chard (Beta vulgaris), saltbush (Atriplex nummularia), Salicornia meyeriana and sorghum (Sorghum bicolor), grew efficiently in brewery effluent irrigated soils but did not stop sodium accumulation in the growth medium. Swiss chard had the best growth with a wet biomass accumulation of 8,173 g m-2, due to the plant’s ability to tolerate saline conditions and continuous cropping. Crop rotation, to limit effects of nutrient depletion in soil, had no significant effect on plant growth suggesting soils were adequately able to provide micro-nutrients in the short-term. Prolonged irrigation with brewery effluent can lead to sodium accumulation in the soil, which was successfully controlled through the addition of soil amendments (gypsum and Trichoderma cultures). These reduced soil sodium from a potentially limiting level of 1,398 mg L-1 to the acceptable levels of 240 mg L-1 and 353 mg L-1 respectively, mainly through leaching. However only Trichoderma improved Swiss chard production to 11,238 g m-2. While crop rotation in this work did not contribute to mitigating the problem of salt accumulation, soil amended with Trichoderma appears to be a potential solution when brewery effluent is reused in agriculture. In an alternative to soil cultivation, CWs were trialled with no significant differences in the sodium concentration of brewery effluent treated along a 15 m lateral flow CW, which could be attributed to evapotranspiration. This was notably accompanied by a desirable 95.21% decrease in ammonia from inlet to outlet resulting in significant improvement in water quality for reuse in aquaculture where ammonia levels are important limiting constraints. While CWs remain a suitable brewery effluent treatment solution, this technology requires additional modelling and optimisation in order to mitigate the problem of salt accumulation in the reuse of treated brewery effluent in agriculture and aquaculture. This research demonstrates the baseline information for such modelling and optimisation. African catfish (Clarias gariepinus) grew in CW treated brewery effluent; however, this growth was moderate at 0.92% bw day-1, whereas Mozambique tilapia (Oreochromis mossambicus) were shown to be unsuited to growth in this system and lost weight with an average specific growth rate (SGR) of -0.98% bw day-1; and both fish species presenting with health related concerns. Hardy fish species such as African catfish can be cultured in brewery effluent, but with risk involved. This was a preliminary study to develop parameters for future dimensional analysis modelling to allow optimisation of the CW, based on nutrient removal rates obtained which will allow for improved downstream aquaculture by reducing or eliminating risks presented in this study. This work has also contributed to a foundation for the development of guidelines that use a risk-based approach for water use in aquaculture. Alternatives to the current in place cleaning agents were considered to mitigate the effects of salt accumulation. Sodium is introduced into the effluent via the use of sodium hydroxide and sodium chlorite for cleaning and disinfection in the brewery, as well as through effluent pH adjustment in the AD plant. The widespread use of outdated legacy cleaning systems and pH adjustment regimes is entrenched in the brewery standard operating procedures (SOP). A cost-benefit analysis (CBA) demonstrated that a change of cleaning and disinfecting regimes to hydrogen peroxide in the brewery, and magnesium hydroxide pH adjustment in the effluent treatment plant addresses the sodium issue upstream in the brewery practically eliminating sodium from the effluent. In addition, a life cycle analysis (LCA) was carried out to assess the environmental impacts associated with the alternative cleaning and pH adjustment scenarios. The LCA showed that electricity consumption during use phase of the chemicals for respective purposes, as well as their production activities were major contributors to the significant environmental impact categories that were assessed. The cleaning scenario employing the use of hydrogen peroxide for both cleaning and disinfection was found to be the most environmentally sustainable. This was attributed to the reduced number of chemicals used compared to the other cleaning scenarios. Dolomitic lime was the pH adjustment alternative with the lowest average environmental impact; but, however, had a higher impact on freshwater eutrophication which is of major concern if the effluent will be reused for irrigation. Magnesium hydroxide was therefore considered to be the better option as a sodium hydroxide alternative for pH adjustment. This mitigates salt accumulation, making treated brewery effluent suitable for reuse in high value downstream agriculture and aquaculture, while employing more environmentally sustainable technologies. Notably, this converts brewery effluent from a financial liability to Ibhayi Brewery, into a product containing water and nutrients that generate income, improve food security, and can create employment in downstream agriculture and aquaculture in a sustainable manner. , Thesis (PhD) -- Faculty of Science, Ichthyology and Fisheries Science, 2021
- Full Text:
- Date Issued: 2021-10-29
Modifcations to gravitational waves due to matter shells
- Authors: Naidoo, Monogaran
- Date: 2021-10-29
- Subjects: Gravitational waves , General relativity (Physics) , Einstein field equations , Cosmology , Matter shells
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/191118 , vital:45062 , 10.21504/10962/191119
- Description: As detections of gravitational waves (GWs) mount, the need to investigate various effects on the propagation of these waves from the time of emission until detection also grows. We investigate how a thin low density dust shell surrounding a gravitational wave source affects the propagation of GWs. The Bondi-Sachs (BS) formalism for the Einstein equations is used for the problem of a gravitational wave (GW) source surrounded by a spherical dust shell. Using linearised perturbation theory, we and the geometry of the regions exterior to, interior to and within the shell. We and that the dust shell causes the gravitational wave to be modified both in magnitude and phase, but without any energy being transferred to or from the dust. This finding is novel. In the context of cosmology, apart from the gravitational redshift, the effects are too small to be measurable; but the effect would be measurable if a GW event were to occur with a source surrounded by a massive shell and with the radius of the shell and the wavelength of the GWs of the same order. We extended our investigation to astrophysical scenarios such as binary black hole (BBH) mergers, binary neutron star (BNS) mergers, and core collapse supernovae (CCSNe). In these scenarios, instead of a monochromatic GW source, as we used in our initial investigation, we consider burst-like GW sources. The thin density shell approach is modified to include thick shells by considering concentric thin shells and integrating. Solutions are then found for these burst-like GW sources using Fourier transforms. We show that GW echoes that are claimed to be present in the Laser Interferometer Gravitational-Wave Observatory (LIGO) data of certain events, could not have been caused by a matter shell. We do and, however, that matter shells surrounding BBH mergers, BNS mergers, and CCSNe could make modifications of order a few percent to a GW signal. These modifications are expected to be measurable in GW data with current detectors if the event is close enough and at a detectable frequency; or in future detectors with increased frequency range and amplitude sensitivity. Substantial use is made of computer algebra in these investigations. In setting the scene for our investigations, we trace the evolution of general relativity (GR) from Einstein's postulation in 1915 to vindication of his theory with the confirmation of the existence of GWs a century later. We discuss the implications of our results to current and future considerations. Calculations of GWs, both analytical and numerical, have normally assumed their propagation from source to a detector on Earth in a vacuum spacetime, and so discounted the effect of intervening matter. As we enter an era of precision GW measurements, it becomes important to quantify any effects due to propagation of GWs through a non-vacuum spacetime Observational confirmation of the modification effect that we and in astrophysical scenarios involving black holes (BHs), neutron stars (NSs) and CCSNe, would also enhance our understanding of the details of the physics of these bodies. , Thesis (PhD) -- Faculty of Science, Mathematics (Pure and Applied), 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Naidoo, Monogaran
- Date: 2021-10-29
- Subjects: Gravitational waves , General relativity (Physics) , Einstein field equations , Cosmology , Matter shells
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/191118 , vital:45062 , 10.21504/10962/191119
- Description: As detections of gravitational waves (GWs) mount, the need to investigate various effects on the propagation of these waves from the time of emission until detection also grows. We investigate how a thin low density dust shell surrounding a gravitational wave source affects the propagation of GWs. The Bondi-Sachs (BS) formalism for the Einstein equations is used for the problem of a gravitational wave (GW) source surrounded by a spherical dust shell. Using linearised perturbation theory, we and the geometry of the regions exterior to, interior to and within the shell. We and that the dust shell causes the gravitational wave to be modified both in magnitude and phase, but without any energy being transferred to or from the dust. This finding is novel. In the context of cosmology, apart from the gravitational redshift, the effects are too small to be measurable; but the effect would be measurable if a GW event were to occur with a source surrounded by a massive shell and with the radius of the shell and the wavelength of the GWs of the same order. We extended our investigation to astrophysical scenarios such as binary black hole (BBH) mergers, binary neutron star (BNS) mergers, and core collapse supernovae (CCSNe). In these scenarios, instead of a monochromatic GW source, as we used in our initial investigation, we consider burst-like GW sources. The thin density shell approach is modified to include thick shells by considering concentric thin shells and integrating. Solutions are then found for these burst-like GW sources using Fourier transforms. We show that GW echoes that are claimed to be present in the Laser Interferometer Gravitational-Wave Observatory (LIGO) data of certain events, could not have been caused by a matter shell. We do and, however, that matter shells surrounding BBH mergers, BNS mergers, and CCSNe could make modifications of order a few percent to a GW signal. These modifications are expected to be measurable in GW data with current detectors if the event is close enough and at a detectable frequency; or in future detectors with increased frequency range and amplitude sensitivity. Substantial use is made of computer algebra in these investigations. In setting the scene for our investigations, we trace the evolution of general relativity (GR) from Einstein's postulation in 1915 to vindication of his theory with the confirmation of the existence of GWs a century later. We discuss the implications of our results to current and future considerations. Calculations of GWs, both analytical and numerical, have normally assumed their propagation from source to a detector on Earth in a vacuum spacetime, and so discounted the effect of intervening matter. As we enter an era of precision GW measurements, it becomes important to quantify any effects due to propagation of GWs through a non-vacuum spacetime Observational confirmation of the modification effect that we and in astrophysical scenarios involving black holes (BHs), neutron stars (NSs) and CCSNe, would also enhance our understanding of the details of the physics of these bodies. , Thesis (PhD) -- Faculty of Science, Mathematics (Pure and Applied), 2021
- Full Text:
- Date Issued: 2021-10-29
Museums for the Planet: Critical Realist Philosophy and the Possibility of an Eco-decolonial Museology
- Authors: Jeffery, Thomas Carnegie
- Date: 2021-10-29
- Subjects: Museums Management , Critical realism , Ontology , Decolonization , Organizational change , Social ecology , Eco-decolonial
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/192692 , vital:45251 , 10.21504/10962/192692
- Description: This study introduces dialectical critical realism into museology as a philosophical underlabourer for the development of new theoretical potentials for the transformation of museum practice. The idea of the museum is in a moment of fluidity evident in emergent decolonial and ecological perspectives and in the International Council of Museum’s process of redefinition of the museum. The potential to reimagine the museum lacks a coherent philosophical and theoretical foundation. The persistence of museological dualism separates the social from the ecological and absents the emergence of relational modes of thinking and practice. This study conceives an ecological-decolonial or eco-decolonial mode of museology that is disruptive of dualism and generative of relationality, and is thus generative of agency for deeper, more effective and enduring social-ecological justice. The core of this thesis is the development of the eco-decolonial mode of museology through the DCR onto-axiological chain or ‘MELD’ schema. At 1M a depth ontological analysis augmented by interviews with key informants establishes a dialectic of society and ecology in the museological context. 1M surfaces capitalism and the implicit neoliberal ontology of museology as deep causal mechanisms of the 2E persistence of museological human-nature dualism. The paradox of ‘emancipatory neoliberalism’ is a policy-practice contradiction that absents potentials for transformation of the museum and that is held in place by the grounding ontological activity of museology, collection. The 2E perspective on absences enables the emergence of new transformative pathways towards the 3L vision of the eco-decolonial mode of museology as a (4D) new way of thinking and working to resolve neoliberal restrictions. The fundamental 4D change envisioned for museum philosophy, theory and practice is an ontological transformation from traditionalist human-nature dualism to a progressive human-nature dialectic. A case study considers instances where museum workers exercised the agency to expand practice in this way. Future work using the expansive learning methodology of Change Laboratories will develop and implement the potentials generated by the onto-axiological chain for the eco-decolonial mode to bring real change to traditional, dualist museum practice, in order to ensure the relevance and the agency of the museum as a social structure in and for a changing world. , Thesis (PhD) -- Faculty of Education, Education, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Jeffery, Thomas Carnegie
- Date: 2021-10-29
- Subjects: Museums Management , Critical realism , Ontology , Decolonization , Organizational change , Social ecology , Eco-decolonial
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/192692 , vital:45251 , 10.21504/10962/192692
- Description: This study introduces dialectical critical realism into museology as a philosophical underlabourer for the development of new theoretical potentials for the transformation of museum practice. The idea of the museum is in a moment of fluidity evident in emergent decolonial and ecological perspectives and in the International Council of Museum’s process of redefinition of the museum. The potential to reimagine the museum lacks a coherent philosophical and theoretical foundation. The persistence of museological dualism separates the social from the ecological and absents the emergence of relational modes of thinking and practice. This study conceives an ecological-decolonial or eco-decolonial mode of museology that is disruptive of dualism and generative of relationality, and is thus generative of agency for deeper, more effective and enduring social-ecological justice. The core of this thesis is the development of the eco-decolonial mode of museology through the DCR onto-axiological chain or ‘MELD’ schema. At 1M a depth ontological analysis augmented by interviews with key informants establishes a dialectic of society and ecology in the museological context. 1M surfaces capitalism and the implicit neoliberal ontology of museology as deep causal mechanisms of the 2E persistence of museological human-nature dualism. The paradox of ‘emancipatory neoliberalism’ is a policy-practice contradiction that absents potentials for transformation of the museum and that is held in place by the grounding ontological activity of museology, collection. The 2E perspective on absences enables the emergence of new transformative pathways towards the 3L vision of the eco-decolonial mode of museology as a (4D) new way of thinking and working to resolve neoliberal restrictions. The fundamental 4D change envisioned for museum philosophy, theory and practice is an ontological transformation from traditionalist human-nature dualism to a progressive human-nature dialectic. A case study considers instances where museum workers exercised the agency to expand practice in this way. Future work using the expansive learning methodology of Change Laboratories will develop and implement the potentials generated by the onto-axiological chain for the eco-decolonial mode to bring real change to traditional, dualist museum practice, in order to ensure the relevance and the agency of the museum as a social structure in and for a changing world. , Thesis (PhD) -- Faculty of Education, Education, 2021
- Full Text:
- Date Issued: 2021-10-29
Negotiating shame: An exploration of the body experience among young South African women who have attended or are attending University
- Authors: Spyker, Jessica Grace
- Date: 2021-10-29
- Subjects: Shame , Body image in women , Body image Social aspects , College students Social conditions , College students Attitudes , Feminist aesthetics , Self-perception in women
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/294880 , vital:57265
- Description: Guided by phenomenological and feminist phenomenological perspectives, this research aimed to explore the ways in which young South African women, who were attending or had recently graduated from university, navigated body shame. It interrogated the socially situated ‘lived body’ and the way it was impacted by restrictive appearance ideals. Fifteen in-depth interviews were conducted, mostly through the video conferencing website Zoom. It became evident that women experienced their bodies in complex ways. There was evidence of conformity to as well as resistance against the “regime of shame”. Conformity and resistance often happened simultaneously. Both of these kinds of experiences were viewed as valid and explored in their own right. External messages around women’s bodies and how they should look had greatly influenced participants experiences of their own bodies. This included messages from discourses such as postfeminism and the body positivity movement, which informed the ways in which they navigated shame. , Thesis (MA) -- Faculty of Humanities, Sociology, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Spyker, Jessica Grace
- Date: 2021-10-29
- Subjects: Shame , Body image in women , Body image Social aspects , College students Social conditions , College students Attitudes , Feminist aesthetics , Self-perception in women
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/294880 , vital:57265
- Description: Guided by phenomenological and feminist phenomenological perspectives, this research aimed to explore the ways in which young South African women, who were attending or had recently graduated from university, navigated body shame. It interrogated the socially situated ‘lived body’ and the way it was impacted by restrictive appearance ideals. Fifteen in-depth interviews were conducted, mostly through the video conferencing website Zoom. It became evident that women experienced their bodies in complex ways. There was evidence of conformity to as well as resistance against the “regime of shame”. Conformity and resistance often happened simultaneously. Both of these kinds of experiences were viewed as valid and explored in their own right. External messages around women’s bodies and how they should look had greatly influenced participants experiences of their own bodies. This included messages from discourses such as postfeminism and the body positivity movement, which informed the ways in which they navigated shame. , Thesis (MA) -- Faculty of Humanities, Sociology, 2021
- Full Text:
- Date Issued: 2021-10-29
Neutral Atomic Hydrogen in Gravitationally Lensed Systems
- Authors: Blecher, Tariq Dylan
- Date: 2021-10-29
- Subjects: Uncatalogued
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/192776 , vital:45263
- Description: Thesis (PhD) -- Faculty of Law, Law, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Blecher, Tariq Dylan
- Date: 2021-10-29
- Subjects: Uncatalogued
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/192776 , vital:45263
- Description: Thesis (PhD) -- Faculty of Law, Law, 2021
- Full Text:
- Date Issued: 2021-10-29
On the gravitational dual to strongly coupled fluids
- Authors: Shawa, Mark Musonda Webster
- Date: 2021-10-29
- Subjects: Quantum gravity , String models , Gauge fields (Physics) , Scattering amplitude (Nuclear physics) , Quark-gluon plasma , Anti-de Sitter/Conformal Field Theory (AdS/CFT) , Gauge/gravity duality
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/192933 , vital:45280 , 10.21504/10962/192933
- Description: This thesis discusses the prospect of finding the gravitational dual to the strongly coupled conformal fluids, with a special interest in the quark-gluon plasma. Such a task can be achieved by matching certain physical observables of two apparently different theories that are dually related owing to the fact that the same string theory can be viewed in two different ways. This is particularly useful when one of the theories is intractable while its dual is manageable. We begin by postulating a particular type of gravitational theory from which we determine graviton scattering amplitudes in a special regime of high momentum. Using the gauge–gravity duality dictionary, the graviton scattering amplitudes can be mapped to stress-tensor correlation functions in the gauge theory. One of the outcomes of high-energy scattering experiments involving the quark-gluon plasma is stress-tensor correlator data. This thesis provides an algorithm for matching graviton scattering amplitudes with stress-tensor correlator data which, in principle, can be used to identify the gravitational dual to the quark-gluon plasma. , Thesis (PhD) -- Faculty of Science, Physics and Electronics, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Shawa, Mark Musonda Webster
- Date: 2021-10-29
- Subjects: Quantum gravity , String models , Gauge fields (Physics) , Scattering amplitude (Nuclear physics) , Quark-gluon plasma , Anti-de Sitter/Conformal Field Theory (AdS/CFT) , Gauge/gravity duality
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/192933 , vital:45280 , 10.21504/10962/192933
- Description: This thesis discusses the prospect of finding the gravitational dual to the strongly coupled conformal fluids, with a special interest in the quark-gluon plasma. Such a task can be achieved by matching certain physical observables of two apparently different theories that are dually related owing to the fact that the same string theory can be viewed in two different ways. This is particularly useful when one of the theories is intractable while its dual is manageable. We begin by postulating a particular type of gravitational theory from which we determine graviton scattering amplitudes in a special regime of high momentum. Using the gauge–gravity duality dictionary, the graviton scattering amplitudes can be mapped to stress-tensor correlation functions in the gauge theory. One of the outcomes of high-energy scattering experiments involving the quark-gluon plasma is stress-tensor correlator data. This thesis provides an algorithm for matching graviton scattering amplitudes with stress-tensor correlator data which, in principle, can be used to identify the gravitational dual to the quark-gluon plasma. , Thesis (PhD) -- Faculty of Science, Physics and Electronics, 2021
- Full Text:
- Date Issued: 2021-10-29
On the Wiener index of bicyclic graphs and graphs with fixed segment sequence
- Authors: Xhanti, Sinoxolo
- Date: 2021-10-29
- Subjects: Graph theory , Chemistry Mathematics , Chemistry Graphic methods , Wiener index , Bicyclic graphs , Fixed segment sequence , Degree sequence , Circumference , Core
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/190700 , vital:45019
- Description: Wiener index is defined as the sum of the distances between all unordered pairs of vertices in a graph. The study of the Wiener index is motivated by its application in chemistry. This thesis focuses on finding extremal bicyclic graphs relative to Wiener index under various conditions such as fixed circumference (length of the longest cycle) or fixed size of the core (maximal subgraph with no degree less than 2). A segment of a graph G is either a path whose end vertices have degree 1 or at least 3 in G and all the internal vertices have degree 2 in G, or a cycle where all the vertices have degree 2 in G except possibly one. The lengths of all the segments of G form it segment sequence. We also discuss extremal graphs with given segment sequence. , Thesis (MSc) -- Faculty of Science, Mathematics, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Xhanti, Sinoxolo
- Date: 2021-10-29
- Subjects: Graph theory , Chemistry Mathematics , Chemistry Graphic methods , Wiener index , Bicyclic graphs , Fixed segment sequence , Degree sequence , Circumference , Core
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/190700 , vital:45019
- Description: Wiener index is defined as the sum of the distances between all unordered pairs of vertices in a graph. The study of the Wiener index is motivated by its application in chemistry. This thesis focuses on finding extremal bicyclic graphs relative to Wiener index under various conditions such as fixed circumference (length of the longest cycle) or fixed size of the core (maximal subgraph with no degree less than 2). A segment of a graph G is either a path whose end vertices have degree 1 or at least 3 in G and all the internal vertices have degree 2 in G, or a cycle where all the vertices have degree 2 in G except possibly one. The lengths of all the segments of G form it segment sequence. We also discuss extremal graphs with given segment sequence. , Thesis (MSc) -- Faculty of Science, Mathematics, 2021
- Full Text:
- Date Issued: 2021-10-29
Opportunities for the inclusion of Environmental Education in the Namibia Senior Secondary Certificate, Geography, Grade 11-12: a case study from Namibia
- Authors: Ashipala, Helena Taakondjo
- Date: 2021-10-29
- Subjects: Environmental education Namibia , Geography Study and teaching (Secondary) , Teacher participation in curriculum planning Namibia , Geography teachers Training of Namibia , Student-centered learning Namibia , Action competence
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/245725 , vital:51399
- Description: Geography is widely recognised in Namibia as a subject within the curriculum that has been framed for understanding and resolving environment issues and sustainable development. It is in this light that this study examined the inclusion of opportunities for environmental education (EE)1 embedded in the Grade 11-12 Geography curriculum in the Namibian context. This study is undertaken as a case study of two schools in the Omusati region in northern Namibia. It investigated opportunities for EE that are embedded in the Geography curriculum using action competence as a lens to review the curriculum and how teachers are working with it in two rural school contexts. This study employed qualitative methods, specifically semi-structured interviews, an analysis of curriculum documents, classroom observations and focus group interviews. Ethical issues were taken into consideration throughout the study. The key findings from the study are: 1. The specification of EE has mainly emerged as a series of concerns that present as topics to be taught and compared with similar concerns in other parts of the world; 2. Teachers have little experience of what and how to teach and inform environmental education within their classrooms; 3. Learners are not actively involved in seeking and probing environmental concerns or in seeking solutions to these. These findings have been used to make recommendations that teachers: 1. Revisit and review the curriculum documents to carry theory into classroom practice; 2. Encourage learners’ participation to enhance their interest and emotional responsibility in environmental education. The study concludes by calling for further research into EE in Geography. This can be used to improve EE in the region where this study was conducted and beyond. , Thesis (MEd) -- Faculty of Education, Education, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Ashipala, Helena Taakondjo
- Date: 2021-10-29
- Subjects: Environmental education Namibia , Geography Study and teaching (Secondary) , Teacher participation in curriculum planning Namibia , Geography teachers Training of Namibia , Student-centered learning Namibia , Action competence
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/245725 , vital:51399
- Description: Geography is widely recognised in Namibia as a subject within the curriculum that has been framed for understanding and resolving environment issues and sustainable development. It is in this light that this study examined the inclusion of opportunities for environmental education (EE)1 embedded in the Grade 11-12 Geography curriculum in the Namibian context. This study is undertaken as a case study of two schools in the Omusati region in northern Namibia. It investigated opportunities for EE that are embedded in the Geography curriculum using action competence as a lens to review the curriculum and how teachers are working with it in two rural school contexts. This study employed qualitative methods, specifically semi-structured interviews, an analysis of curriculum documents, classroom observations and focus group interviews. Ethical issues were taken into consideration throughout the study. The key findings from the study are: 1. The specification of EE has mainly emerged as a series of concerns that present as topics to be taught and compared with similar concerns in other parts of the world; 2. Teachers have little experience of what and how to teach and inform environmental education within their classrooms; 3. Learners are not actively involved in seeking and probing environmental concerns or in seeking solutions to these. These findings have been used to make recommendations that teachers: 1. Revisit and review the curriculum documents to carry theory into classroom practice; 2. Encourage learners’ participation to enhance their interest and emotional responsibility in environmental education. The study concludes by calling for further research into EE in Geography. This can be used to improve EE in the region where this study was conducted and beyond. , Thesis (MEd) -- Faculty of Education, Education, 2021
- Full Text:
- Date Issued: 2021-10-29
Peer-to-peer energy trading system using IoT and a low-computation blockchain network
- Authors: Ncube, Tyron
- Date: 2021-10-29
- Subjects: Blockchains (Databases) , Internet of things , Renewable energy sources , Smart power grids , Peer-to-peer architecture (Computer networks) , Energy trading system
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/192119 , vital:45197
- Description: The use of renewable energy is increasing every year as it is seen as a viable and sustain- able long-term alternative to fossil-based sources of power. Emerging technologies are being merged with existing renewable energy systems to address some of the challenges associated with renewable energy, such as reliability and limited storage facilities for the generated energy. The Internet of Things (IoT) has made it possible for consumers to make money by selling off excess energy back to the utility company through smart grids that allow bi-directional communication between the consumer and the utility company. The major drawback of this is that the utility company still plays a central role in this setup as they are the only buyer of this excess energy generated from renewable energy sources. This research intends to use blockchain technology by leveraging its decentralized architecture to enable other individuals to be able to purchase this excess energy. Blockchain technology is first explained in detail, and its main features, such as consensus mechanisms, are examined. This evaluation of blockchain technology gives rise to some design questions that are taken into consideration to create a low-energy, low-computation Ethereum-based blockchain network that is the foundation for a peer-to-peer energy trading system. The peer-to-peer energy trading system makes use of smart meters to collect data about energy usage and gives users a web-based interface where they can transact with each other. A smart contract is also designed to facilitate payments for transactions. Lastly, the system is tested by carrying out transactions and transferring energy from one node in the system to another. , Thesis (MSc) -- Faculty of Science, Computer Science, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Ncube, Tyron
- Date: 2021-10-29
- Subjects: Blockchains (Databases) , Internet of things , Renewable energy sources , Smart power grids , Peer-to-peer architecture (Computer networks) , Energy trading system
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/192119 , vital:45197
- Description: The use of renewable energy is increasing every year as it is seen as a viable and sustain- able long-term alternative to fossil-based sources of power. Emerging technologies are being merged with existing renewable energy systems to address some of the challenges associated with renewable energy, such as reliability and limited storage facilities for the generated energy. The Internet of Things (IoT) has made it possible for consumers to make money by selling off excess energy back to the utility company through smart grids that allow bi-directional communication between the consumer and the utility company. The major drawback of this is that the utility company still plays a central role in this setup as they are the only buyer of this excess energy generated from renewable energy sources. This research intends to use blockchain technology by leveraging its decentralized architecture to enable other individuals to be able to purchase this excess energy. Blockchain technology is first explained in detail, and its main features, such as consensus mechanisms, are examined. This evaluation of blockchain technology gives rise to some design questions that are taken into consideration to create a low-energy, low-computation Ethereum-based blockchain network that is the foundation for a peer-to-peer energy trading system. The peer-to-peer energy trading system makes use of smart meters to collect data about energy usage and gives users a web-based interface where they can transact with each other. A smart contract is also designed to facilitate payments for transactions. Lastly, the system is tested by carrying out transactions and transferring energy from one node in the system to another. , Thesis (MSc) -- Faculty of Science, Computer Science, 2021
- Full Text:
- Date Issued: 2021-10-29
Perceptions and experience of school violence among teachers and learners within a black township in the Sarah Baartman District, Eastern Cape, South Africa
- Authors: Ndemka, Sibulela
- Date: 2021-10-29
- Subjects: School violence South Africa Eastern Cape , Teachers South Africa Eastern Cape Attitudes , High school students South Africa Eastern Cape Attitudes , High school students Conduct of life , High school students Economic conditions , High school students Social conditions , Social constructionism South Africa Eastern Cape
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/190760 , vital:45025
- Description: In exploring the knowledge/awarness of school violence within the teacher and student school relationship. The principal objective of the study was to investigate the perceptions and experiences of school violence among teachers and learners by reference to a public high school in a historically black African, working class township in the Sarah Baartman District Municipality, Eastern Cape Province, South Africa. The high school was chosen for its geographical location within the community and relative nature of shared stories of violence within the surrounding vicinity. The conceptual, theoretical, and analytical frameworks underpinning this study is social constructionism theory, expanding from the theoretical claim that violence is socially constructed through the process of socialisation and institutionalization. The study reviewed relavant literature on violence in South African schools highlighting the relationship of school violence to current social and educational challenges and crises and the impact that school violence has on learners, teachers, and communities. The research methodology employed is qualitative and evidence was derived through semi-structured in-depth interviews. A sample male and female teachers and learners were recruited through networking. The researcher recruited participants outside the school and through participant referrals to uncover intricacies of school violence drawing on relevant literature in relation to the dynamics of this social and institutional problem. Data was analysed and thematically presented in line with the research objectives. The study findings imply that school violence is complex and gendered. Arguing that cultural, socio-economic, family, community, and social interpersonal factors account for school violence in South Africa. Male teachers and students mostly bieng the victims and perpetrators, implicating this behaviour to a culture of toxic masculinity and shared complicities as contributing factors to school violence. In addition, the study found that the change in status and expectations of boys who return from initiation sometimes provoked violence between initiated learners and adults who did not accord them the respect expected post-initiation. , Thesis (MSocSci) -- Faculty of Humanities, Sociology, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Ndemka, Sibulela
- Date: 2021-10-29
- Subjects: School violence South Africa Eastern Cape , Teachers South Africa Eastern Cape Attitudes , High school students South Africa Eastern Cape Attitudes , High school students Conduct of life , High school students Economic conditions , High school students Social conditions , Social constructionism South Africa Eastern Cape
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/190760 , vital:45025
- Description: In exploring the knowledge/awarness of school violence within the teacher and student school relationship. The principal objective of the study was to investigate the perceptions and experiences of school violence among teachers and learners by reference to a public high school in a historically black African, working class township in the Sarah Baartman District Municipality, Eastern Cape Province, South Africa. The high school was chosen for its geographical location within the community and relative nature of shared stories of violence within the surrounding vicinity. The conceptual, theoretical, and analytical frameworks underpinning this study is social constructionism theory, expanding from the theoretical claim that violence is socially constructed through the process of socialisation and institutionalization. The study reviewed relavant literature on violence in South African schools highlighting the relationship of school violence to current social and educational challenges and crises and the impact that school violence has on learners, teachers, and communities. The research methodology employed is qualitative and evidence was derived through semi-structured in-depth interviews. A sample male and female teachers and learners were recruited through networking. The researcher recruited participants outside the school and through participant referrals to uncover intricacies of school violence drawing on relevant literature in relation to the dynamics of this social and institutional problem. Data was analysed and thematically presented in line with the research objectives. The study findings imply that school violence is complex and gendered. Arguing that cultural, socio-economic, family, community, and social interpersonal factors account for school violence in South Africa. Male teachers and students mostly bieng the victims and perpetrators, implicating this behaviour to a culture of toxic masculinity and shared complicities as contributing factors to school violence. In addition, the study found that the change in status and expectations of boys who return from initiation sometimes provoked violence between initiated learners and adults who did not accord them the respect expected post-initiation. , Thesis (MSocSci) -- Faculty of Humanities, Sociology, 2021
- Full Text:
- Date Issued: 2021-10-29
Performing Emil Hartmann – The Importance of Musical Contextualisation: A practice-based research project
- Authors: Robertson, Garreth Damon
- Date: 2021-10-29
- Subjects: Hartmann, Emil, 1836-1898 , Hartmann, Emil, 1836-1898 Criticism and interpretation History 19th century , Practice (Philosophy) , Research Methodology , Contextualism (Philosophy) , Music Denmark History and criticism , Music appreciation , Musical analysis
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/190771 , vital:45026
- Description: When embarking on a journey of preparing a musical work for performance, a contextualisation process is undertaken which informs the performer/s of the factors which govern the parameters of the work. In this study, the author performed Emil Hartmann’s piano trio op. 10 as a part of an integrated master’s degree program. As the composer was not a part of mainland European musical society, information on his life and work was difficult to access, which presented the performer with a contextualisation problem. This study aimed to highlight the process of contextualisation, in the absence of sufficient literary material, through the lens of Emil Hartmann’s piano trio op. 10. The research used a three-pronged methodological approach in order to construct the narrative around Hartmann’s life and composition. Through a structured process of using practice-based research to analyse the creative process undertaken by the practitioners, alongside a micro-historical and analytical methodology, the study builds layers of understanding to inform Hartmann’s narrative, and thus provides interpretational insight into the execution of the work. The research finds that, although it is possible to interpret a musical work based on the musical score, there are layers of depth which cannot be accessed without a contextual understanding of the composer and the conditions in which the composition was written. Through forming the narrative on Emil Hartmann and his piano trio, the research uses the methodology to highlight a method which can be undertaken in the absence of contextual knowledge, and thus presents a contextual understanding of Emil Hartmann’s narrative. With the constructed knowledge, the author uses the findings based on the methodological approaches to weave a narrative around the life of Emil Hartmann. Applying the information discovered in the findings, interpretational approaches are discussed to inform future performances of the work. , Thesis (MMus) -- Faculty of Humanities, Music and Musicology, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Robertson, Garreth Damon
- Date: 2021-10-29
- Subjects: Hartmann, Emil, 1836-1898 , Hartmann, Emil, 1836-1898 Criticism and interpretation History 19th century , Practice (Philosophy) , Research Methodology , Contextualism (Philosophy) , Music Denmark History and criticism , Music appreciation , Musical analysis
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/190771 , vital:45026
- Description: When embarking on a journey of preparing a musical work for performance, a contextualisation process is undertaken which informs the performer/s of the factors which govern the parameters of the work. In this study, the author performed Emil Hartmann’s piano trio op. 10 as a part of an integrated master’s degree program. As the composer was not a part of mainland European musical society, information on his life and work was difficult to access, which presented the performer with a contextualisation problem. This study aimed to highlight the process of contextualisation, in the absence of sufficient literary material, through the lens of Emil Hartmann’s piano trio op. 10. The research used a three-pronged methodological approach in order to construct the narrative around Hartmann’s life and composition. Through a structured process of using practice-based research to analyse the creative process undertaken by the practitioners, alongside a micro-historical and analytical methodology, the study builds layers of understanding to inform Hartmann’s narrative, and thus provides interpretational insight into the execution of the work. The research finds that, although it is possible to interpret a musical work based on the musical score, there are layers of depth which cannot be accessed without a contextual understanding of the composer and the conditions in which the composition was written. Through forming the narrative on Emil Hartmann and his piano trio, the research uses the methodology to highlight a method which can be undertaken in the absence of contextual knowledge, and thus presents a contextual understanding of Emil Hartmann’s narrative. With the constructed knowledge, the author uses the findings based on the methodological approaches to weave a narrative around the life of Emil Hartmann. Applying the information discovered in the findings, interpretational approaches are discussed to inform future performances of the work. , Thesis (MMus) -- Faculty of Humanities, Music and Musicology, 2021
- Full Text:
- Date Issued: 2021-10-29
Pessimism and the secular problem of evil
- Authors: Ruiters, Siphamandla
- Date: 2021-10-29
- Subjects: Good and evil , Pessimism , Optimism , Secularism , Quality of life
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/190111 , vital:44964
- Description: How should we respond to the prevalence of ubiquitous evil? In this thesis, I present two responses to the secular problem of evil. The secular problem of evil exists because we want to live good lives, but we are all existentially vulnerable to evil. Consequently, we can think of various ways in which evil's existence poses a problem for us. When faced with such evil, I distinguish two responses that we may adopt, namely, optimistic or pessimistic responses to the secular problem of evil. These responses may be understood as stances that we may adopt about the relative evil and goodness in the world. Once I have made a thorough evaluation of the discussion around the secular problem of evil and the responses, I will suggest that pessimism is an appealing and appropriate response that we should adopt. To achieve the aims of this thesis, I will first clarify the kind of evil at stake in this thesis and then explain how philosophers have historically responded to this problem. Secondly, I will focus on the contemporary discussion on the secular problem of evil and show the responses are optimistic responses. Finally, I will provide a case against optimism and then show why pessimism is the most appealing and appropriate response. , Thesis (MA) -- Faculty of Humanities, Philosophy, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Ruiters, Siphamandla
- Date: 2021-10-29
- Subjects: Good and evil , Pessimism , Optimism , Secularism , Quality of life
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/190111 , vital:44964
- Description: How should we respond to the prevalence of ubiquitous evil? In this thesis, I present two responses to the secular problem of evil. The secular problem of evil exists because we want to live good lives, but we are all existentially vulnerable to evil. Consequently, we can think of various ways in which evil's existence poses a problem for us. When faced with such evil, I distinguish two responses that we may adopt, namely, optimistic or pessimistic responses to the secular problem of evil. These responses may be understood as stances that we may adopt about the relative evil and goodness in the world. Once I have made a thorough evaluation of the discussion around the secular problem of evil and the responses, I will suggest that pessimism is an appealing and appropriate response that we should adopt. To achieve the aims of this thesis, I will first clarify the kind of evil at stake in this thesis and then explain how philosophers have historically responded to this problem. Secondly, I will focus on the contemporary discussion on the secular problem of evil and show the responses are optimistic responses. Finally, I will provide a case against optimism and then show why pessimism is the most appealing and appropriate response. , Thesis (MA) -- Faculty of Humanities, Philosophy, 2021
- Full Text:
- Date Issued: 2021-10-29
Photosynthetic microbial fuel cells and fabricated photobioreactors applied with halotolerant microorganisms for nutrient and metal remediation under adverse hypersaline
- Authors: Smith, Galad Gilbert
- Date: 2021-10-29
- Subjects: Uncatalogued
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/192561 , vital:45237
- Description: Thesis (MSc) -- Faculty of Science, Biotechnology Innovation Centre, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Smith, Galad Gilbert
- Date: 2021-10-29
- Subjects: Uncatalogued
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/192561 , vital:45237
- Description: Thesis (MSc) -- Faculty of Science, Biotechnology Innovation Centre, 2021
- Full Text:
- Date Issued: 2021-10-29
Phthalocyanine-nanoparticle conjugates supported on inorganic nanofibers as photocatalysts for the treatment of biological and organic pollutants as well as for hydrogen generation
- Authors: Mapukata, Sivuyisiwe
- Date: 2021-10-29
- Subjects: Phthalocyanines , Nanofibers , Nanoparticles , Zinc , Hydrogen , Organic water pollutants , Water Purification , Electrospinning , Photocatalysis , Photodegradation , Anti-infective agents
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/192831 , vital:45268 , 10.21504/10962/192831
- Description: This thesis reports on the synthesis, photophysicochemical and photocatalytic properties of various zinc phthalocyanines (Pcs). For enhanced properties and catalyst support, the reported Pcs were conjugated to different nanoparticles (NPs) through chemisorption as well as amide bond formation to yield Pc-NP conjugates. For increased catalyst surface area and catalyst reusability, the Pcs and some of their conjugates were also supported on electrospun inorganic nanofibers i.e. SiO2, hematite (abbreviated Hem and has formula α-Fe2O3), ZnO and TiO2 nanofibers. The effect that the number of charges on a Pc has on its antimicrobial activities was evaluated by comparing the photoactivities of neutral, octacationic and hexadecacationic Pcs against S. aureus, E. coli and C. albicans. The extent of enhancement of their antimicrobial activities upon conjugation (through chemisorption) to Ag NPs was also studied in solution and when supported on SiO2 nanofibers. The results showed that the hexadecacationic complex 3 possessed the best antimicrobial activity against all three microorganisms, in solution and when supported on the SiO2 nanofibers. Covalent conjugation of Pcs with carboxylic acid moieties (complexes 4-6) to amine functionalised NPs (Cys-Ag, NH2-Fe3O4 and Cys-Fe3O4@Ag) resulted in enhanced singlet oxygen generation and thus antibacterial efficiencies. Comparison of the photodegradation efficiencies of semiconductor nanofibers (hematite, ZnO and TiO2) when bare and when modified with a Pc (complex 6) were evaluated. Modification of the nanofibers with the Pc resulted in enhanced photoactivities for the nanofibers with the hematite nanofibers being the best. Modification of the hematite nanofibers with two different Pcs i.e. monosubstituted (complex 5) and an asymmetrical tetrasubstituted Pc (complex 6) showed that complex 6 better enhanced the activity of the nanofibers. Evaluation of the hydrogen generation efficiencies of the bare and modified TiO2 nanofibers calcined at different temperatures demonstrated that the anatase nanofibers calcined at 500 oC possessed the best catalytic efficiency. The efficiency of the TiO2 nanofibers was enhanced in the presence of the Co and Pd NPs as well as a Pc (complex 7), with the extent of enhancement being the greatest for the nanofibers modified with the Pd NPs. The reported findings therefore demonstrate the versatility of applications of Pcs for different water purification techniques when supported on different nanomaterials. , Thesis (PhD) -- Faculty of Science, Chemistry, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Mapukata, Sivuyisiwe
- Date: 2021-10-29
- Subjects: Phthalocyanines , Nanofibers , Nanoparticles , Zinc , Hydrogen , Organic water pollutants , Water Purification , Electrospinning , Photocatalysis , Photodegradation , Anti-infective agents
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/192831 , vital:45268 , 10.21504/10962/192831
- Description: This thesis reports on the synthesis, photophysicochemical and photocatalytic properties of various zinc phthalocyanines (Pcs). For enhanced properties and catalyst support, the reported Pcs were conjugated to different nanoparticles (NPs) through chemisorption as well as amide bond formation to yield Pc-NP conjugates. For increased catalyst surface area and catalyst reusability, the Pcs and some of their conjugates were also supported on electrospun inorganic nanofibers i.e. SiO2, hematite (abbreviated Hem and has formula α-Fe2O3), ZnO and TiO2 nanofibers. The effect that the number of charges on a Pc has on its antimicrobial activities was evaluated by comparing the photoactivities of neutral, octacationic and hexadecacationic Pcs against S. aureus, E. coli and C. albicans. The extent of enhancement of their antimicrobial activities upon conjugation (through chemisorption) to Ag NPs was also studied in solution and when supported on SiO2 nanofibers. The results showed that the hexadecacationic complex 3 possessed the best antimicrobial activity against all three microorganisms, in solution and when supported on the SiO2 nanofibers. Covalent conjugation of Pcs with carboxylic acid moieties (complexes 4-6) to amine functionalised NPs (Cys-Ag, NH2-Fe3O4 and Cys-Fe3O4@Ag) resulted in enhanced singlet oxygen generation and thus antibacterial efficiencies. Comparison of the photodegradation efficiencies of semiconductor nanofibers (hematite, ZnO and TiO2) when bare and when modified with a Pc (complex 6) were evaluated. Modification of the nanofibers with the Pc resulted in enhanced photoactivities for the nanofibers with the hematite nanofibers being the best. Modification of the hematite nanofibers with two different Pcs i.e. monosubstituted (complex 5) and an asymmetrical tetrasubstituted Pc (complex 6) showed that complex 6 better enhanced the activity of the nanofibers. Evaluation of the hydrogen generation efficiencies of the bare and modified TiO2 nanofibers calcined at different temperatures demonstrated that the anatase nanofibers calcined at 500 oC possessed the best catalytic efficiency. The efficiency of the TiO2 nanofibers was enhanced in the presence of the Co and Pd NPs as well as a Pc (complex 7), with the extent of enhancement being the greatest for the nanofibers modified with the Pd NPs. The reported findings therefore demonstrate the versatility of applications of Pcs for different water purification techniques when supported on different nanomaterials. , Thesis (PhD) -- Faculty of Science, Chemistry, 2021
- Full Text:
- Date Issued: 2021-10-29
Plant-fungal mutualism as a strategy for the bioremediation of hydrocarbon polluted soils
- Authors: Keshinro, Olajide Muritala
- Date: 2021-10-29
- Subjects: Mutualism (Biology) , Plant-fungus relationships , Bioremediation , Mucilage , Plant exudates , Extracellular polymeric substances , Laccase , Peroxidase , Phytoremediation , Ligninolytic enzymes
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/190918 , vital:45041 , 10.21504/10962/190918
- Description: Inasmuch as coal remains the linchpin for the generation of electricity and liquid petroleum products in South Africa, hydrocarbon waste and coal discard will continue to pose a threat to the environment. Therefore, the onus is on the associated industries to develop and implement efficient and sustainable strategies to mitigate the negative impacts of energy generating activities on the environment. Most conventional efforts in this regard, although successful for soil repair and the initiation of vegetation, have been deemed unsustainable. In an effort to find a sustainable remediation strategy a novel technology termed “FungCoal” was conceptualized and patented as a strategy for the rehabilitation of open cast coal mines, carbonaceous-rich spoils and coal wastes. This biotechnology, which exploits plant-fungal mutualism to achieve effective biodegradation of coal on discard dumps and the breakdown of the carbonaceous component in spoils, promotes revegetation to facilitate rehabilitation of mining-disturbed land. However, one limiting factor of the FungCoal bioprocess is that it requires oxidized weathered coal, a highly complex and variable resource for use as a co-substrate, for growth and proliferation of the coal degrading microorganisms. To fully exploit the potential of plant-fungal mutualism and its interaction for use in the remediation of coal contaminated soils, this study investigated the proposed relationship between plant roots, root exudate and the coal degrading fungus “Aspergillus sp.” (previously Neosartorya fischeri) strain 84 in more detail, in an effort to gain further insight into the mechanisms underpinning plant-fungal mutualism as a strategy for re-vegetation of coal discard dumps and the rehabilitation of hydrocarbon-contaminated soil using the FungCoal approach. A pot-on-beaker (PoB) method was developed for the easy cultivation and collection of extracellular polymeric substance (EPS)-containing exudates from Zea mays L. (maize) and Abelmuschus esculentus (okra). Characterisation of the EPS material from these exudates was carried out using a combination of physicochemical and biochemical methods. The results from analysis of phenolics and indoles showed that exudates contain some form of indoles and phenolic compounds, although in little proportions, which may fulfil a signalling function, responsible for attracting soil microorganisms into the rhizosphere. Spectroscopic analysis of the exudates using FT-IR revealed vibrations corresponding to functional groups of alkanes, alkenes, alkynes, and carboxylic acids. These compounds likely provide an easily accessible source of carbon to soil microorganisms and are also a better alternative to the poly-aromatics which are an inherent component locked-up in the supposed recalcitrant coal material. The results from biochemical analyses also revealed the presence of carbohydrate, proteins, lipids, and low amounts of α-amino-nitrogen in the EPS of maize and okra. These components of EPS are all essential for the stimulation of enzymatic activities in soil microorganisms and, which may in turn aid biodegradation. The action of the root EPS from maize was further tested on three coal-degrading fungal isolates identified as Aspergillus strain ECCN 84, Aspergillus strain ECCN 225 and Penicillium strain ECCN 243 for manganese peroxidase (MnP) and laccase (LAC) activities. The results revealed that the Aspergillus species, strains ECCN 84 and ECCN 225, showed with or without EPS, observable black halos surrounding each of the colonies after 7d incubation indicative of positive MnP activity, while no activity was observed for the Penicillium sp. strain ECCN 243. Analysis for LAC revealed little or no activity in any of the coal degrading fungi following addition of pulverized coal to the growth medium. Interestingly, the addition of EPS-containing exudate to the coal-containing medium resulted in increased LAC activity for all fungal isolates. This finding affirmed the positive contribution of EPS to extracellular LAC activity, purported as an important enzyme in the coal biodegradation process. Finally, the impact of plant-derived exudate on the colonisation and biodegradation of coal was investigated in situ using rhizoboxes, to simulate a coal environment, and was carried out for 16 weeks. Microscopic examination of coal samples after termination of the experiment showed fungal proliferation and attachment to coal particles. All of the rhizoboxes that contained plants had higher medium pH and EC, and the concentration of phenolics, indoles and humic acids was greater than that of control treatments. These observations indicated better rhizosphere colonisation, substrate biodegradation and humification. Therefore, root exudate appears to play a significant role in coordination of soil microorganisms within the rhizosphere and likely serves both as a scaffold for rhizospheric interactions by providing microorganisms with accessible carbon and as a likely ‘trigger’ for induction of coal-degrading enzymes such as fungal LAC for mobilisation of recalcitrant carbon. This study has shown that EPS exuded from roots of Zea mays together with coal degrading fungus Aspergillus strain ECCN 84 can alkalinise the coal substrate and facilitate introduction of oxygen, possibly as a result of increased laccase activity, and increase availability of nutrients (as indicated by higher EC) in a coal-polluted rhizosphere, to provide plants and their associated mycorrhizae and presumably other beneficial microorganisms a more mesic environment for sustained phytoremediation with enhanced rehabilitation potential. In conclusion, this study confirms the positive role of root exudate in mediating a mutualistic rehabilitation strategy involving plants and fungi such as the FungCoal bioprocess. , Thesis (PhD) -- Faculty of Science, Institute for Environmental Biotechnology, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Keshinro, Olajide Muritala
- Date: 2021-10-29
- Subjects: Mutualism (Biology) , Plant-fungus relationships , Bioremediation , Mucilage , Plant exudates , Extracellular polymeric substances , Laccase , Peroxidase , Phytoremediation , Ligninolytic enzymes
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/190918 , vital:45041 , 10.21504/10962/190918
- Description: Inasmuch as coal remains the linchpin for the generation of electricity and liquid petroleum products in South Africa, hydrocarbon waste and coal discard will continue to pose a threat to the environment. Therefore, the onus is on the associated industries to develop and implement efficient and sustainable strategies to mitigate the negative impacts of energy generating activities on the environment. Most conventional efforts in this regard, although successful for soil repair and the initiation of vegetation, have been deemed unsustainable. In an effort to find a sustainable remediation strategy a novel technology termed “FungCoal” was conceptualized and patented as a strategy for the rehabilitation of open cast coal mines, carbonaceous-rich spoils and coal wastes. This biotechnology, which exploits plant-fungal mutualism to achieve effective biodegradation of coal on discard dumps and the breakdown of the carbonaceous component in spoils, promotes revegetation to facilitate rehabilitation of mining-disturbed land. However, one limiting factor of the FungCoal bioprocess is that it requires oxidized weathered coal, a highly complex and variable resource for use as a co-substrate, for growth and proliferation of the coal degrading microorganisms. To fully exploit the potential of plant-fungal mutualism and its interaction for use in the remediation of coal contaminated soils, this study investigated the proposed relationship between plant roots, root exudate and the coal degrading fungus “Aspergillus sp.” (previously Neosartorya fischeri) strain 84 in more detail, in an effort to gain further insight into the mechanisms underpinning plant-fungal mutualism as a strategy for re-vegetation of coal discard dumps and the rehabilitation of hydrocarbon-contaminated soil using the FungCoal approach. A pot-on-beaker (PoB) method was developed for the easy cultivation and collection of extracellular polymeric substance (EPS)-containing exudates from Zea mays L. (maize) and Abelmuschus esculentus (okra). Characterisation of the EPS material from these exudates was carried out using a combination of physicochemical and biochemical methods. The results from analysis of phenolics and indoles showed that exudates contain some form of indoles and phenolic compounds, although in little proportions, which may fulfil a signalling function, responsible for attracting soil microorganisms into the rhizosphere. Spectroscopic analysis of the exudates using FT-IR revealed vibrations corresponding to functional groups of alkanes, alkenes, alkynes, and carboxylic acids. These compounds likely provide an easily accessible source of carbon to soil microorganisms and are also a better alternative to the poly-aromatics which are an inherent component locked-up in the supposed recalcitrant coal material. The results from biochemical analyses also revealed the presence of carbohydrate, proteins, lipids, and low amounts of α-amino-nitrogen in the EPS of maize and okra. These components of EPS are all essential for the stimulation of enzymatic activities in soil microorganisms and, which may in turn aid biodegradation. The action of the root EPS from maize was further tested on three coal-degrading fungal isolates identified as Aspergillus strain ECCN 84, Aspergillus strain ECCN 225 and Penicillium strain ECCN 243 for manganese peroxidase (MnP) and laccase (LAC) activities. The results revealed that the Aspergillus species, strains ECCN 84 and ECCN 225, showed with or without EPS, observable black halos surrounding each of the colonies after 7d incubation indicative of positive MnP activity, while no activity was observed for the Penicillium sp. strain ECCN 243. Analysis for LAC revealed little or no activity in any of the coal degrading fungi following addition of pulverized coal to the growth medium. Interestingly, the addition of EPS-containing exudate to the coal-containing medium resulted in increased LAC activity for all fungal isolates. This finding affirmed the positive contribution of EPS to extracellular LAC activity, purported as an important enzyme in the coal biodegradation process. Finally, the impact of plant-derived exudate on the colonisation and biodegradation of coal was investigated in situ using rhizoboxes, to simulate a coal environment, and was carried out for 16 weeks. Microscopic examination of coal samples after termination of the experiment showed fungal proliferation and attachment to coal particles. All of the rhizoboxes that contained plants had higher medium pH and EC, and the concentration of phenolics, indoles and humic acids was greater than that of control treatments. These observations indicated better rhizosphere colonisation, substrate biodegradation and humification. Therefore, root exudate appears to play a significant role in coordination of soil microorganisms within the rhizosphere and likely serves both as a scaffold for rhizospheric interactions by providing microorganisms with accessible carbon and as a likely ‘trigger’ for induction of coal-degrading enzymes such as fungal LAC for mobilisation of recalcitrant carbon. This study has shown that EPS exuded from roots of Zea mays together with coal degrading fungus Aspergillus strain ECCN 84 can alkalinise the coal substrate and facilitate introduction of oxygen, possibly as a result of increased laccase activity, and increase availability of nutrients (as indicated by higher EC) in a coal-polluted rhizosphere, to provide plants and their associated mycorrhizae and presumably other beneficial microorganisms a more mesic environment for sustained phytoremediation with enhanced rehabilitation potential. In conclusion, this study confirms the positive role of root exudate in mediating a mutualistic rehabilitation strategy involving plants and fungi such as the FungCoal bioprocess. , Thesis (PhD) -- Faculty of Science, Institute for Environmental Biotechnology, 2021
- Full Text:
- Date Issued: 2021-10-29
Potential of the Gravel Filter Towers, Pilot-scale Filter system and Biochar/Clay adsorbents for Bio-Physicochemical remediation and Desalination of greywater
- Authors: Bani, Siphumze
- Date: 2021-10-29
- Subjects: Uncatalogued
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/188375 , vital:44748
- Description: Thesis embargoed until 2023 , Thesis (MSc) -- Faculty of Science, Rhodes University Biotechnology Innovation Centre, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Bani, Siphumze
- Date: 2021-10-29
- Subjects: Uncatalogued
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/188375 , vital:44748
- Description: Thesis embargoed until 2023 , Thesis (MSc) -- Faculty of Science, Rhodes University Biotechnology Innovation Centre, 2021
- Full Text:
- Date Issued: 2021-10-29
Power in periods: a Foucauldian-feminist exploration of menstruation in an all-girls’ secondary school in South Africa
- Authors: Parkinson, Catherine Anne
- Date: 2021-10-29
- Subjects: Menstruation South Africa , Menstruation Social aspects South Africa , High school girls Health and hygiene South Africa , Communication in reproductive health South Africa , Sexual health South Africa , Sex differences (Psychology) in adolescence South Africa , Male domination (Social structure) South Africa , Feminist theory , Foucault, Michel, 1926-1984. Surveiller et punir. English , Discourse analysis
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/190930 , vital:45042
- Description: Absenteeism from school among girls due to a lack of menstrual health management (MHM) products has increasingly attracted attention from researchers and activists in recent years. Having highlighted the challenges caused by a lack of MHM products, the focus has been on the available facilities at schools to ensure MHM. Many schools in South Africa lack water, sanitation and hygiene (WASH) to ensure hygiene standards for the removal of bodily excre-ment, which further causes distress to girls needing MHM while at school. To investigate fur-ther the MHM challenges girls face, apart from access to products and WASH, this qualita-tive study purposively selected an all-girls’ school with access to good sanitation facilities. This research uses Foucauldian Discourse Analysis and Feminist Theory to explore the forms of discipline and control that girls experience at school to contain their bodily functioning and fluids, and the forms of resistance and support that girls encounter with MHM at school. I will argue that the ambivalent meanings girls acquire about menstruation at home and in soci-ety persist at school despite their own views that menstruation is normal. While MHM prod-ucts and WASH facilities need to be freely available, the problematic social response to men-struation is what needs to be addressed in order to emancipate women from the social patriar-chal power that informs their understanding that menstruation is shameful. MHM cannot only encompass products and facilities but needs to encompass a change in societal views of sex-ual and reproductive health. , Thesis (MA) -- Faculty of Humanities, Psychology, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Parkinson, Catherine Anne
- Date: 2021-10-29
- Subjects: Menstruation South Africa , Menstruation Social aspects South Africa , High school girls Health and hygiene South Africa , Communication in reproductive health South Africa , Sexual health South Africa , Sex differences (Psychology) in adolescence South Africa , Male domination (Social structure) South Africa , Feminist theory , Foucault, Michel, 1926-1984. Surveiller et punir. English , Discourse analysis
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/190930 , vital:45042
- Description: Absenteeism from school among girls due to a lack of menstrual health management (MHM) products has increasingly attracted attention from researchers and activists in recent years. Having highlighted the challenges caused by a lack of MHM products, the focus has been on the available facilities at schools to ensure MHM. Many schools in South Africa lack water, sanitation and hygiene (WASH) to ensure hygiene standards for the removal of bodily excre-ment, which further causes distress to girls needing MHM while at school. To investigate fur-ther the MHM challenges girls face, apart from access to products and WASH, this qualita-tive study purposively selected an all-girls’ school with access to good sanitation facilities. This research uses Foucauldian Discourse Analysis and Feminist Theory to explore the forms of discipline and control that girls experience at school to contain their bodily functioning and fluids, and the forms of resistance and support that girls encounter with MHM at school. I will argue that the ambivalent meanings girls acquire about menstruation at home and in soci-ety persist at school despite their own views that menstruation is normal. While MHM prod-ucts and WASH facilities need to be freely available, the problematic social response to men-struation is what needs to be addressed in order to emancipate women from the social patriar-chal power that informs their understanding that menstruation is shameful. MHM cannot only encompass products and facilities but needs to encompass a change in societal views of sex-ual and reproductive health. , Thesis (MA) -- Faculty of Humanities, Psychology, 2021
- Full Text:
- Date Issued: 2021-10-29