A battle of values: analysing the changing attitudes towards African refugees in Europe
- Authors: Mannion, Megan Kate
- Date: 2024-04-04
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/435525 , vital:73165
- Description: Cosmopolitanism is a moral perspective that stresses the importance that every human being is an equal and ultimate unit of moral concern. These principles make cosmopolitanism more concerned for and accommodative towards outsiders to a political community. Against the abstraction and universalism of cosmopolitanism, communitarianism emphasizes the role communities play in shaping our individual identities and sees it as justified that the interests and well-being of community members receive priority over those of outsiders. Both these value systems are present in Europe. The question is about which direction the trend has moved in recent decades. This dissertation examines the changing values that inform attitudes toward African refugees in Europe to get at this issue. Have attitudes towards African refugees shifted in a cosmopolitan or a communitarian direction in recent decades? This dissertation examines newspaper articles from The Guardian between 1990 and 2022 to track changes in value. The analysis of these articles uncovered that communitarian values were the most prevalent and stayed the most prevalent from 1990 to 2022. These findings indicate that communitarian values are higher than cosmopolitan values regarding African refugees within the general European context. These findings add to the growing body of knowledge regarding attitude shifts, and they provide a timeline for value changes that can help predict future values and be used in future comparative studies. , Thesis (MA) -- Faculty of Humanities, Political and International Studies, 2024
- Full Text:
- Date Issued: 2024-04-04
- Authors: Mannion, Megan Kate
- Date: 2024-04-04
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/435525 , vital:73165
- Description: Cosmopolitanism is a moral perspective that stresses the importance that every human being is an equal and ultimate unit of moral concern. These principles make cosmopolitanism more concerned for and accommodative towards outsiders to a political community. Against the abstraction and universalism of cosmopolitanism, communitarianism emphasizes the role communities play in shaping our individual identities and sees it as justified that the interests and well-being of community members receive priority over those of outsiders. Both these value systems are present in Europe. The question is about which direction the trend has moved in recent decades. This dissertation examines the changing values that inform attitudes toward African refugees in Europe to get at this issue. Have attitudes towards African refugees shifted in a cosmopolitan or a communitarian direction in recent decades? This dissertation examines newspaper articles from The Guardian between 1990 and 2022 to track changes in value. The analysis of these articles uncovered that communitarian values were the most prevalent and stayed the most prevalent from 1990 to 2022. These findings indicate that communitarian values are higher than cosmopolitan values regarding African refugees within the general European context. These findings add to the growing body of knowledge regarding attitude shifts, and they provide a timeline for value changes that can help predict future values and be used in future comparative studies. , Thesis (MA) -- Faculty of Humanities, Political and International Studies, 2024
- Full Text:
- Date Issued: 2024-04-04
The role of sustainability perceptions of employees in corporate sustainability
- Authors: Cronjé, René
- Date: 2024-04
- Subjects: Corporations -- Environmental aspects , Corporate governance -- Environmental aspects , Sustainability , Climatic changes Environmental economics -- South Africa Sustainability -- Economic aspects -- South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/64918 , vital:73959
- Description: The purpose of this study is to investigate the relationship between employees' perception of environmental sustainability and pro-environmental behaviour within the corporate business environment of South Africa and its influence on a company’s corporate sustainability efforts. The study will follow a case study approach involving the employees of a corporate state-owned company in the logistics industry of the Nelson Mandela Bay area. In doing so the study attempts to better understand why enterprises, in their attempts to promote corporate sustainability, face challenges in aligning their variety of sustainability strategies, policies, and initiatives with employees' willingness to implement these measures or engage in pro-environmental behaviour in the workplace. To delve deeper into this issue the study also explores potential reasons for differences in perceptions by examining potential correlations between perceptions of environmental sustainability and pro-environmental behaviour, considering demographic factors such as gender, age, education, and work experience. The collective findings of the study underscore a positive relationship between employees’ environmental perception and their engagement in pro-environmental behaviour. This suggests that individuals who express a higher degree of concern for environmental issues are more likely to adopt and engage in environmentally-friendly behaviours. However, a notable disconnect was identified between awareness and action, highlighting variability in the extent to which perception translates into active pro-environmental behaviour. While environmental perception serves as a strong motivator, there is evident room for improvement in translating these concerns into concrete actions within the corporate setting. These insights emphasise the importance of addressing both attitudes and behaviours in the context of environmental sustainability. Thus, to enhance corporate sustainability efforts, it is imperative for companies to bridge the gap between environmental perception and action among their employees. The demographic variables (gender, age, education, and work experience) showed no significant influence on environmental perception or pro-environmental behaviour in this study, however these empirical findings challenge common findings in the existent literature, thus emphasising the need for a more nuanced understanding of the subject, within specific contexts. Recommendations for future studies include: larger sample sizes for robust findings; exploration of the influence of academic disciplines; consideration of household income and cultural differences; and broadening the study to multiple departments in order to gather more , Thesis (MBA) -- Faculty of Business and Economic Sciences, Business School, 2024
- Full Text:
- Date Issued: 2024-04
- Authors: Cronjé, René
- Date: 2024-04
- Subjects: Corporations -- Environmental aspects , Corporate governance -- Environmental aspects , Sustainability , Climatic changes Environmental economics -- South Africa Sustainability -- Economic aspects -- South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/64918 , vital:73959
- Description: The purpose of this study is to investigate the relationship between employees' perception of environmental sustainability and pro-environmental behaviour within the corporate business environment of South Africa and its influence on a company’s corporate sustainability efforts. The study will follow a case study approach involving the employees of a corporate state-owned company in the logistics industry of the Nelson Mandela Bay area. In doing so the study attempts to better understand why enterprises, in their attempts to promote corporate sustainability, face challenges in aligning their variety of sustainability strategies, policies, and initiatives with employees' willingness to implement these measures or engage in pro-environmental behaviour in the workplace. To delve deeper into this issue the study also explores potential reasons for differences in perceptions by examining potential correlations between perceptions of environmental sustainability and pro-environmental behaviour, considering demographic factors such as gender, age, education, and work experience. The collective findings of the study underscore a positive relationship between employees’ environmental perception and their engagement in pro-environmental behaviour. This suggests that individuals who express a higher degree of concern for environmental issues are more likely to adopt and engage in environmentally-friendly behaviours. However, a notable disconnect was identified between awareness and action, highlighting variability in the extent to which perception translates into active pro-environmental behaviour. While environmental perception serves as a strong motivator, there is evident room for improvement in translating these concerns into concrete actions within the corporate setting. These insights emphasise the importance of addressing both attitudes and behaviours in the context of environmental sustainability. Thus, to enhance corporate sustainability efforts, it is imperative for companies to bridge the gap between environmental perception and action among their employees. The demographic variables (gender, age, education, and work experience) showed no significant influence on environmental perception or pro-environmental behaviour in this study, however these empirical findings challenge common findings in the existent literature, thus emphasising the need for a more nuanced understanding of the subject, within specific contexts. Recommendations for future studies include: larger sample sizes for robust findings; exploration of the influence of academic disciplines; consideration of household income and cultural differences; and broadening the study to multiple departments in order to gather more , Thesis (MBA) -- Faculty of Business and Economic Sciences, Business School, 2024
- Full Text:
- Date Issued: 2024-04
Improved service delivery through financial management mechanisms: a case of O. R Tambo District Municipality
- Dunywa, Petronella Andiswa Xoliswa
- Authors: Dunywa, Petronella Andiswa Xoliswa
- Date: 2023-12
- Subjects: Financial management , Finance, Public -- South Africa -- Eastern Cape , Corporations -- Finance
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/65589 , vital:74199
- Description: The study investigated how effective and efficient financial management mechanisms can lead to improved service delivery in the O. R Tambo District Municipality. The study targeted the political leadership, senior and middle management, and key Budget and Treasury Office (BTO) personnel. The non-probability sampling method was used in the study with semi structured interviews conducted on a seventy-one sample size. The results of the interviews were analysed and pointed to the importance of sound financial management systems being critical to enhancing service delivery in the O. R Tambo District. The levels of understanding the role of financial management systems in municipalities differed across levels of authority but there was a general consensus of how effective and efficient financial management mechanisms affect service delivery. In conclusions municipalities need to continuously strive to skill and reskill personnel to maximize on efficiency and improved service delivery. , Thesis (MPhil) -- Faculty of Business and Economic Sciences, School of Economics, Development and Tourism, 2023
- Full Text:
- Date Issued: 2023-12
- Authors: Dunywa, Petronella Andiswa Xoliswa
- Date: 2023-12
- Subjects: Financial management , Finance, Public -- South Africa -- Eastern Cape , Corporations -- Finance
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/65589 , vital:74199
- Description: The study investigated how effective and efficient financial management mechanisms can lead to improved service delivery in the O. R Tambo District Municipality. The study targeted the political leadership, senior and middle management, and key Budget and Treasury Office (BTO) personnel. The non-probability sampling method was used in the study with semi structured interviews conducted on a seventy-one sample size. The results of the interviews were analysed and pointed to the importance of sound financial management systems being critical to enhancing service delivery in the O. R Tambo District. The levels of understanding the role of financial management systems in municipalities differed across levels of authority but there was a general consensus of how effective and efficient financial management mechanisms affect service delivery. In conclusions municipalities need to continuously strive to skill and reskill personnel to maximize on efficiency and improved service delivery. , Thesis (MPhil) -- Faculty of Business and Economic Sciences, School of Economics, Development and Tourism, 2023
- Full Text:
- Date Issued: 2023-12
Halogenated Aza-BODIPY dyes for photodynamic anticancer and antimicrobial activity studies
- Magwaza, Temlandvo Matshidiso
- Authors: Magwaza, Temlandvo Matshidiso
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424514 , vital:72160
- Description: This thesis reports on the synthesis and characterisation of differently substituted aza-BODIPY dyes for use in photodynamic antimicrobial chemotherapy (PACT) and photodynamic therapy (PDT) activity studies. The aza-BODIPY dyes were synthesised by adding phenyl and naphthyl rings at the 3,5-positions of the aza-BODIPY core, with methylthiolphenyl (9a and 9b, respectively) or thien-2-yl rings (9c and 9d, respectively) at the 1,7-positions. 9a-c were iodinated at the 2-position to form 10a-c, respectively, while 9d was diiodinated at the 2,6-positions to form 10d. The methylthiolphenyl-substituted dyes (10a and 10b) were successfully conjugated to gold nanoparticles (AuNPs) to form nanoparticles conjugates (10a-AuNPs and 10b-AuNPs), while attempts to conjugate the thien-2-yl-substituted dyes were unsuccessful. The photophysicochemical properties of 9a-d, 10a-d and nanoconjugates 10a-AuNPs and 10b-AuNPs were investigated to determine their suitability for use in the applications. Adding heavy atoms such as iodine at the 2,6-positions of the aza-BODIPY led to enhanced singlet oxygen generation since these dyes displayed moderate to high singlet oxygen quantum yields. None of the dyes exhibited any fluorescence. The PACT activity studies for 9c-d, 10a-d, and the 10a-AuNPs and 10b-AuNPs were carried out against Staphylococcus aureus and Escherichia coli with a Thorlabs M660L3 light-emitting diode (LED) with an irradiance of 280 mW/cm2 for all dyes other than 10d. A Thorlabs M730L4 LED with an irradiance of 160 mW/cm2 was used for 10d. Time dependence studies were only carried out against Staphylococcus aureus, so very low log reductions were observed against Escherichia coli in initial concentration studies. The 10a-AuNP and 10b-AuNP nanoconjugates exhibited high antimicrobial activity with a log reduction of 9.41 and 0.00% viable colonies, while the iodinated aza-BODIPY had a log reduction of 8.94. The in vitro photodynamic therapy activities and dark cytotoxicity were investigated against human MCF-7 breast cancer cells for dyes 9c-d and 10c-d with a Thorlabs M660L3 LED (280 mW/cm2) for all dyes. The dark cytotoxicity was minimal in each case with IC50 > 50. Iodinated dyes 10c and 10d had IC50 values of 11.6 and 8.2 μM, respectively, and non-iodinated dyes 9c and 9d had IC50 values of 12.5 and 19.2 μM. The heavy atom effect associated with the iodine atoms increases the singlet oxygen quantum yield and enhances the suitability of the dyes for photodynamic therapy. , Thesis (MSc) -- Faculty of Science, Chemistry, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Magwaza, Temlandvo Matshidiso
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424514 , vital:72160
- Description: This thesis reports on the synthesis and characterisation of differently substituted aza-BODIPY dyes for use in photodynamic antimicrobial chemotherapy (PACT) and photodynamic therapy (PDT) activity studies. The aza-BODIPY dyes were synthesised by adding phenyl and naphthyl rings at the 3,5-positions of the aza-BODIPY core, with methylthiolphenyl (9a and 9b, respectively) or thien-2-yl rings (9c and 9d, respectively) at the 1,7-positions. 9a-c were iodinated at the 2-position to form 10a-c, respectively, while 9d was diiodinated at the 2,6-positions to form 10d. The methylthiolphenyl-substituted dyes (10a and 10b) were successfully conjugated to gold nanoparticles (AuNPs) to form nanoparticles conjugates (10a-AuNPs and 10b-AuNPs), while attempts to conjugate the thien-2-yl-substituted dyes were unsuccessful. The photophysicochemical properties of 9a-d, 10a-d and nanoconjugates 10a-AuNPs and 10b-AuNPs were investigated to determine their suitability for use in the applications. Adding heavy atoms such as iodine at the 2,6-positions of the aza-BODIPY led to enhanced singlet oxygen generation since these dyes displayed moderate to high singlet oxygen quantum yields. None of the dyes exhibited any fluorescence. The PACT activity studies for 9c-d, 10a-d, and the 10a-AuNPs and 10b-AuNPs were carried out against Staphylococcus aureus and Escherichia coli with a Thorlabs M660L3 light-emitting diode (LED) with an irradiance of 280 mW/cm2 for all dyes other than 10d. A Thorlabs M730L4 LED with an irradiance of 160 mW/cm2 was used for 10d. Time dependence studies were only carried out against Staphylococcus aureus, so very low log reductions were observed against Escherichia coli in initial concentration studies. The 10a-AuNP and 10b-AuNP nanoconjugates exhibited high antimicrobial activity with a log reduction of 9.41 and 0.00% viable colonies, while the iodinated aza-BODIPY had a log reduction of 8.94. The in vitro photodynamic therapy activities and dark cytotoxicity were investigated against human MCF-7 breast cancer cells for dyes 9c-d and 10c-d with a Thorlabs M660L3 LED (280 mW/cm2) for all dyes. The dark cytotoxicity was minimal in each case with IC50 > 50. Iodinated dyes 10c and 10d had IC50 values of 11.6 and 8.2 μM, respectively, and non-iodinated dyes 9c and 9d had IC50 values of 12.5 and 19.2 μM. The heavy atom effect associated with the iodine atoms increases the singlet oxygen quantum yield and enhances the suitability of the dyes for photodynamic therapy. , Thesis (MSc) -- Faculty of Science, Chemistry, 2023
- Full Text:
- Date Issued: 2023-10-13
Appraising the sustainability of groud water quantity and quality
- Authors: Mkosana, Kululwa
- Date: 2023-00
- Subjects: Geography
- Language: English
- Type: Masters theses , text
- Identifier: http://hdl.handle.net/11260/9398 , vital:73516
- Description: South Africa is a semi-arid region that suffers from water scarcity. With a changing climate, incidents such as droughts and human migration will exacerbate the water scarcity already experienced. Thus, the assessment of groundwater quality and quantity is a major step toward ensuring a viable sustainable water argumentation for general use and to serve as one of the most basic needs of human beings. Hence, this study appraises the sustainability of groundwater resource availability and assesses its water quality at the King Sabatha Dalindyebo Local Municipality within the Mthatha River Catchment (MRC). The objectives were to: i) examine the extent of groundwater potential in the area ii) investigate the determinant factors that characterized the groundwater and surface water interaction and assess the impacts of climatic variables on yield iii) compare the physico-chemical and microbial concentration samples collected at different boreholes in the MRC with respect to South African and World Health Organization (WHO) standards and iv) develop the temporal variation trend in modeling the groundwater quality parameters. Using a systematic sampling method, a preliminary survey was carried out to identify the location and selection of the appropriate boreholes’ representation. Thereafter, reconnaissance map and characterisation of the 10 selected borehole's location was made to spatially represent the sites. The water samples were made thrice per site (totally 30 samples). The collected samples were transported to Talbot and Talbot Laboratory, where they were analysed for their physico-chemical and bacteriological parameters using established procedures. Other parameters such as depth of hole, water level, borehole yield, abstraction rate, the screen length, drawdown, morphometry, geological, land-use variables, were generated after rigorous geographical information system (GIS) analysis in QGIS environment and Excel in achieving the study aims. The Soil and Water Assessment Tool (SWAT) model was used for the estimation of the groundwater flow or baseflow drawing strength from the hydraulic conductivity of the aquifer flow (Ksat) (mm/day), sub-basin divide for the groundwater system to the main channel Lgw (m), and the water table height (m). Thereafter, the principal iv component analysis, multiple linear regression analysis, and correlation analysis were used to assess the controlling factors for the spatial variation of recharge in the watershed characteristics and assess the impacts of climatic variables on groundwater yield. The simulated results revealed a mean monthly water yield range of 2.7-14.8 m3/s for groundwater over the study years (2000-2019). The development of temporal variation trend modeling of the physico-chemical composition of the groundwater varied from one borehole to another despite their proximity, thus, making it difficult to generalise the water quality parameters fluctuation. The water quality results showed that the majority of the variables are not within acceptable standards. Ammonia and total coliform levels depict a range between 1.5 mg/l minimum to 10 mg/l maximum with to 1000 counts/mL for total coliform. Also, there was no clear relationship between the location of the boreholes and the borehole yield among the selected samples. However, there was a significant difference between the borehole yield and the risk description matrix for the various water quality parameters. Most of the borehole water quality depicts a non-health aesthetic, acute health, and disinfectant status for the area. Keywords: Water scarcity, groundwater, seasonal variability, aquifer scale , Thesis (Masters) -- Faculty of Natural Sciences, 2023
- Full Text:
- Date Issued: 2023-00
- Authors: Mkosana, Kululwa
- Date: 2023-00
- Subjects: Geography
- Language: English
- Type: Masters theses , text
- Identifier: http://hdl.handle.net/11260/9398 , vital:73516
- Description: South Africa is a semi-arid region that suffers from water scarcity. With a changing climate, incidents such as droughts and human migration will exacerbate the water scarcity already experienced. Thus, the assessment of groundwater quality and quantity is a major step toward ensuring a viable sustainable water argumentation for general use and to serve as one of the most basic needs of human beings. Hence, this study appraises the sustainability of groundwater resource availability and assesses its water quality at the King Sabatha Dalindyebo Local Municipality within the Mthatha River Catchment (MRC). The objectives were to: i) examine the extent of groundwater potential in the area ii) investigate the determinant factors that characterized the groundwater and surface water interaction and assess the impacts of climatic variables on yield iii) compare the physico-chemical and microbial concentration samples collected at different boreholes in the MRC with respect to South African and World Health Organization (WHO) standards and iv) develop the temporal variation trend in modeling the groundwater quality parameters. Using a systematic sampling method, a preliminary survey was carried out to identify the location and selection of the appropriate boreholes’ representation. Thereafter, reconnaissance map and characterisation of the 10 selected borehole's location was made to spatially represent the sites. The water samples were made thrice per site (totally 30 samples). The collected samples were transported to Talbot and Talbot Laboratory, where they were analysed for their physico-chemical and bacteriological parameters using established procedures. Other parameters such as depth of hole, water level, borehole yield, abstraction rate, the screen length, drawdown, morphometry, geological, land-use variables, were generated after rigorous geographical information system (GIS) analysis in QGIS environment and Excel in achieving the study aims. The Soil and Water Assessment Tool (SWAT) model was used for the estimation of the groundwater flow or baseflow drawing strength from the hydraulic conductivity of the aquifer flow (Ksat) (mm/day), sub-basin divide for the groundwater system to the main channel Lgw (m), and the water table height (m). Thereafter, the principal iv component analysis, multiple linear regression analysis, and correlation analysis were used to assess the controlling factors for the spatial variation of recharge in the watershed characteristics and assess the impacts of climatic variables on groundwater yield. The simulated results revealed a mean monthly water yield range of 2.7-14.8 m3/s for groundwater over the study years (2000-2019). The development of temporal variation trend modeling of the physico-chemical composition of the groundwater varied from one borehole to another despite their proximity, thus, making it difficult to generalise the water quality parameters fluctuation. The water quality results showed that the majority of the variables are not within acceptable standards. Ammonia and total coliform levels depict a range between 1.5 mg/l minimum to 10 mg/l maximum with to 1000 counts/mL for total coliform. Also, there was no clear relationship between the location of the boreholes and the borehole yield among the selected samples. However, there was a significant difference between the borehole yield and the risk description matrix for the various water quality parameters. Most of the borehole water quality depicts a non-health aesthetic, acute health, and disinfectant status for the area. Keywords: Water scarcity, groundwater, seasonal variability, aquifer scale , Thesis (Masters) -- Faculty of Natural Sciences, 2023
- Full Text:
- Date Issued: 2023-00
On legal expressivism, incorporeal injuries and the equal protection clause: an analysis through the lens of the Civil Union Act
- Authors: Tsele, Michael Vuyo
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/405434 , vital:70171
- Description: Thesis embargoed. To be released in 2024. , Thesis (LLM) -- Faculty of Law, Law, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Tsele, Michael Vuyo
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/405434 , vital:70171
- Description: Thesis embargoed. To be released in 2024. , Thesis (LLM) -- Faculty of Law, Law, 2022
- Full Text:
- Date Issued: 2022-10-14
Production of mannooligosaccharides from pineapple pulp and pine sawdust using Aspergillus niger derived Man26A and determination of their prebiotic effect
- Authors: Hlalukana, Nosipho Pretty
- Date: 2022-10-14
- Subjects: Oligosaccharides , Prebiotics , Lignocellulose , Mannans
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/362853 , vital:65368
- Description: Lignocellulosic biomass is the most abundant source of renewable biomass on earth. Lignocellulosic biomass consists of cellulose, hemicelluloses and lignin. These can be used as a source of renewable fuel as well as other value-added products . Mannans are part of the hemicellulose fraction of lignocellulosic biomass and are the major hemicellulosic polysaccharide fraction in softwoods, where they are found as galactoglucomannans and as glucomannans. Mannans are also found in hardwoods in the form of glucomannans. Mannans can be enzymatically hydrolysed using endo-mannanases to produce of short chain mannooligosaccharides (MOS). MOS have received significant attention for their prebiotic properties, as they promote the growth of probiotic bacteria, which have positively affects on gut health. This study focused on the production of prebiotic MOS from lignocellulosic biomass waste (LBW) and an evaluation of the prebiotic potential of the produced MOS. An Aspergillus niger derived endo-mannanase, Man26A, was fractionated and biochemically analysed. Purified Man26A had a fold purification of 1.25 and a yield of 41.1%. SDS-PAGE analysis of the enzyme revealed that it had a molecular weight of 46 kDa. The pH and temperature optima of Man26A were determined and the pH optimum was found to be pH 4.0 (but the enzyme displayed high activity over a broad acidic pH range, with up to 90% of the activity retained between pH 3.0 and 7.0). The temperature optimum was 50℃. The enzyme was shown to have the highest specific activity on locust bean gum (52.27 U/mg) and ivory nut mannan (57.25 U/mg), compared to guar gum (29.07 U/mg), which indicated that it was affected by the substitution pattern of the mannans. Man26A produced MOS of different diversity on model mannan substrates, where the MOS produced were mannobiose, mannotriose, and mannotetraose for ivory nut mannan, mannobiose, mannotriose, mannotetraose, and mannopentaose and MOS with a higher degree of polymerisation for locust bean gum, and mannobiose, mannotriose, mannotetraose, mannopentaose, and mannohexose and MOS with a higher degree of polymerisation for guar gum, as determined by thin layer chromatography (TLC) and high-performance liquid chromatography (HPLC). Pretreatment and characterisation of pineapple pulp (PP) and pine sawdust (PSD) was conducted, and the impact of the pretreatment procedures was analysed using Megazyme sugar kits, thermogravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FTIR), and microscopic analysis using scanning electron microscopy (SEM) and light microscopy. Compositional analysis of the carbohydrates present in both substrates revealed that they had a glucan content of 36.41 and 50.47% for untreated PP and PSD, respectively. Their respective mannan content was 6.74 and 11.59% and was deemed sufficient for the production of MOS via enzymatic hydrolysis. TGA analysis revealed that untreated and sodium chlorite-acetic acid delignified samples decomposed at approximately the same time, and had a negligible ash content at 600℃, while delignified plus phosphoric acid swollen substrates decomposed at a faster rate, but had a residual ash content at 600℃. FTIR analysis of the substrates revealed slight changes in the structures of untreated and pretreated samples. SEM analysis of PP and PSD showed a change in the morphology of the substrates with subsequent pretreatment steps. Histochemical analysis for lignin for PP and PSD showed successful delignification upon pretreatment. Untreated and sodium chlorite delignified PP and PSD released low amounts of reducing sugars compared to delignified + phosphoric acid swollen substrates. The delignified + phosphoric acid swollen substrates were used for further experiments. MOS produced from delignified and phosphoric acid swollen (Del + PAS) PP and PSD at 0.1 mg/ml enzyme loading and 80 mg/ml (8% (w/v)) substrate concentration, ran between mannose and mannobiose and between mannobiose and manotriose on TLC, with low concentrations of MOS running between mannotetraose and mannopentaose. HPLC analysis of the MOS revealed that Del + PAS PP produced mannose to mannohexose, while Del + PAS PSD produced mannose, mannobiose, and mannotetraose. The MOS were analysed using FTIR, to determine whether the MOS produced contained any acetyl groups, which were present for Del + PAS PSD at 1706 cm-1. The MOS were stable at different pHs, and at temperatures below 200℃. The MOS were also found to be stable in a simulated gastrointestinal environment, in the presence of bile salts and digestive enzymes. The prebiotic effect of the MOS derived from Del + PAS PP and PSD was evaluated. MOS had a proliferative effect on probiotic bacteria (Lactobacillus bulgaricus, Bacillus subtilis and Streptococcus thermophilus). The production of short chain fatty acids (SCFAs) was evaluated on TLC, where no SCFAs were observed on the plate. The effect of MOS on the adhesion ability of bacteria revealed that they do not positively influence the adhesion of probiotic bacteria. The antioxidant activities of 1 mg/ml MOS produced from both substrates were determined to be approximately 15% using the ABTS radical scavenging assay, compared to a radical scavenging activity of 45% for the 0.02 mg/ml gallic acid standard. This study demonstrated that biomass waste could be used to produce prebiotic MOS, which play a positive role in gut ecology and provide health benefits. , Thesis (MSc) -- Faculty of Science, Biochemistry and Microbiology, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Hlalukana, Nosipho Pretty
- Date: 2022-10-14
- Subjects: Oligosaccharides , Prebiotics , Lignocellulose , Mannans
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/362853 , vital:65368
- Description: Lignocellulosic biomass is the most abundant source of renewable biomass on earth. Lignocellulosic biomass consists of cellulose, hemicelluloses and lignin. These can be used as a source of renewable fuel as well as other value-added products . Mannans are part of the hemicellulose fraction of lignocellulosic biomass and are the major hemicellulosic polysaccharide fraction in softwoods, where they are found as galactoglucomannans and as glucomannans. Mannans are also found in hardwoods in the form of glucomannans. Mannans can be enzymatically hydrolysed using endo-mannanases to produce of short chain mannooligosaccharides (MOS). MOS have received significant attention for their prebiotic properties, as they promote the growth of probiotic bacteria, which have positively affects on gut health. This study focused on the production of prebiotic MOS from lignocellulosic biomass waste (LBW) and an evaluation of the prebiotic potential of the produced MOS. An Aspergillus niger derived endo-mannanase, Man26A, was fractionated and biochemically analysed. Purified Man26A had a fold purification of 1.25 and a yield of 41.1%. SDS-PAGE analysis of the enzyme revealed that it had a molecular weight of 46 kDa. The pH and temperature optima of Man26A were determined and the pH optimum was found to be pH 4.0 (but the enzyme displayed high activity over a broad acidic pH range, with up to 90% of the activity retained between pH 3.0 and 7.0). The temperature optimum was 50℃. The enzyme was shown to have the highest specific activity on locust bean gum (52.27 U/mg) and ivory nut mannan (57.25 U/mg), compared to guar gum (29.07 U/mg), which indicated that it was affected by the substitution pattern of the mannans. Man26A produced MOS of different diversity on model mannan substrates, where the MOS produced were mannobiose, mannotriose, and mannotetraose for ivory nut mannan, mannobiose, mannotriose, mannotetraose, and mannopentaose and MOS with a higher degree of polymerisation for locust bean gum, and mannobiose, mannotriose, mannotetraose, mannopentaose, and mannohexose and MOS with a higher degree of polymerisation for guar gum, as determined by thin layer chromatography (TLC) and high-performance liquid chromatography (HPLC). Pretreatment and characterisation of pineapple pulp (PP) and pine sawdust (PSD) was conducted, and the impact of the pretreatment procedures was analysed using Megazyme sugar kits, thermogravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FTIR), and microscopic analysis using scanning electron microscopy (SEM) and light microscopy. Compositional analysis of the carbohydrates present in both substrates revealed that they had a glucan content of 36.41 and 50.47% for untreated PP and PSD, respectively. Their respective mannan content was 6.74 and 11.59% and was deemed sufficient for the production of MOS via enzymatic hydrolysis. TGA analysis revealed that untreated and sodium chlorite-acetic acid delignified samples decomposed at approximately the same time, and had a negligible ash content at 600℃, while delignified plus phosphoric acid swollen substrates decomposed at a faster rate, but had a residual ash content at 600℃. FTIR analysis of the substrates revealed slight changes in the structures of untreated and pretreated samples. SEM analysis of PP and PSD showed a change in the morphology of the substrates with subsequent pretreatment steps. Histochemical analysis for lignin for PP and PSD showed successful delignification upon pretreatment. Untreated and sodium chlorite delignified PP and PSD released low amounts of reducing sugars compared to delignified + phosphoric acid swollen substrates. The delignified + phosphoric acid swollen substrates were used for further experiments. MOS produced from delignified and phosphoric acid swollen (Del + PAS) PP and PSD at 0.1 mg/ml enzyme loading and 80 mg/ml (8% (w/v)) substrate concentration, ran between mannose and mannobiose and between mannobiose and manotriose on TLC, with low concentrations of MOS running between mannotetraose and mannopentaose. HPLC analysis of the MOS revealed that Del + PAS PP produced mannose to mannohexose, while Del + PAS PSD produced mannose, mannobiose, and mannotetraose. The MOS were analysed using FTIR, to determine whether the MOS produced contained any acetyl groups, which were present for Del + PAS PSD at 1706 cm-1. The MOS were stable at different pHs, and at temperatures below 200℃. The MOS were also found to be stable in a simulated gastrointestinal environment, in the presence of bile salts and digestive enzymes. The prebiotic effect of the MOS derived from Del + PAS PP and PSD was evaluated. MOS had a proliferative effect on probiotic bacteria (Lactobacillus bulgaricus, Bacillus subtilis and Streptococcus thermophilus). The production of short chain fatty acids (SCFAs) was evaluated on TLC, where no SCFAs were observed on the plate. The effect of MOS on the adhesion ability of bacteria revealed that they do not positively influence the adhesion of probiotic bacteria. The antioxidant activities of 1 mg/ml MOS produced from both substrates were determined to be approximately 15% using the ABTS radical scavenging assay, compared to a radical scavenging activity of 45% for the 0.02 mg/ml gallic acid standard. This study demonstrated that biomass waste could be used to produce prebiotic MOS, which play a positive role in gut ecology and provide health benefits. , Thesis (MSc) -- Faculty of Science, Biochemistry and Microbiology, 2022
- Full Text:
- Date Issued: 2022-10-14
The relationship between economic growth and taxation: an empirical study on optimal taxation in sub-Saharan Africa
- Authors: Kent, Bradley Athol
- Date: 2022-10-14
- Subjects: Taxation Africa, Sub-Saharan , Optimal tax , Economic development Africa, Sub-Saharan , Tax collection Africa, Sub-Saharan
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/403058 , vital:69918
- Description: The relationship between economic growth and taxation is a complex and highly debated issue, this thesis investigates whether a significant relationship can be identified, and whether it is the level that truly matters for fiscal policies aimed at being growth enhancing. Further investigation examines this relationship, in addition to testing whether there is a threshold below which tax collection may be considered ‘growth-enhancing’, and above which is negative for economic growth, and if such a threshold exists, to identify the manner in which taxation negatively impacts economic growth. The study makes use of a panel data approach to autoregressive distributed lag modelling and a generalised least squares regression. The study focuses on a panel data sample for seven (7) countries within Sub-Saharan Africa (SSA) between 1997 – 2017. It found that total tax revenue held a positive and significant relationship with economic growth at the SSA level, whilst at the individual tax level; PAYE and property taxes were found to have a negative influence on growth, with no other fiscal variables significantly influencing growth in the long run in SSA test. Whereas, when analysing at the country-specific level it was found PAYE was only significantly influencing growth in South Africa, where the relationship was found to be negative. Corporate tax revealed a similar significant negative relationship in Swaziland and Cameroon. In addition, property taxes revealed a significant and negative relationship in South Africa, yet in Rwanda the influence was positive. Overall, the study found that there is significant relationship between economic growth and taxation in the SSA context. However, when analysing the countries in isolation, no such relationship was found. , Thesis (MEcon) -- Faculty of Commerce, Economics and Economic History, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Kent, Bradley Athol
- Date: 2022-10-14
- Subjects: Taxation Africa, Sub-Saharan , Optimal tax , Economic development Africa, Sub-Saharan , Tax collection Africa, Sub-Saharan
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/403058 , vital:69918
- Description: The relationship between economic growth and taxation is a complex and highly debated issue, this thesis investigates whether a significant relationship can be identified, and whether it is the level that truly matters for fiscal policies aimed at being growth enhancing. Further investigation examines this relationship, in addition to testing whether there is a threshold below which tax collection may be considered ‘growth-enhancing’, and above which is negative for economic growth, and if such a threshold exists, to identify the manner in which taxation negatively impacts economic growth. The study makes use of a panel data approach to autoregressive distributed lag modelling and a generalised least squares regression. The study focuses on a panel data sample for seven (7) countries within Sub-Saharan Africa (SSA) between 1997 – 2017. It found that total tax revenue held a positive and significant relationship with economic growth at the SSA level, whilst at the individual tax level; PAYE and property taxes were found to have a negative influence on growth, with no other fiscal variables significantly influencing growth in the long run in SSA test. Whereas, when analysing at the country-specific level it was found PAYE was only significantly influencing growth in South Africa, where the relationship was found to be negative. Corporate tax revealed a similar significant negative relationship in Swaziland and Cameroon. In addition, property taxes revealed a significant and negative relationship in South Africa, yet in Rwanda the influence was positive. Overall, the study found that there is significant relationship between economic growth and taxation in the SSA context. However, when analysing the countries in isolation, no such relationship was found. , Thesis (MEcon) -- Faculty of Commerce, Economics and Economic History, 2022
- Full Text:
- Date Issued: 2022-10-14
Modelling internet network intrusion detection in smart city ecosystems
- Authors: Mfenguza, Wandisa
- Date: 2021-05
- Subjects: Ecosystem management , Smart cities
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22501 , vital:52382
- Description: Smart city systems are intended to enhance the lives of citizens through the design of systems that promote resource efficiency and the real-time provisioning of resources in cities. The benefits offered by smart cities include the use of internet of things (IoT) sensors to gather useful data such as power demand to inhibit blackouts and the average speed of vehicles to alleviate traffic congestion. Nonetheless, earlier studies have indicated a substantial increase in cyber-security issues due to the increase in the deployment of smart city ecosystems. Consequently, IoT cyber-security is recognised as an area that requires crucial scrutiny. This study begins by investigating the current state of intrusion detection in smart city ecosystems. Current intrusion detection frameworks lack the capability to operate under extremely limiting settings such as conditions of low processing power and fast response times. Moreover, the study also identifies that, despite intrusion detection being a highly researched thematic area, a plethora of previous studies tend to propose intrusion detection frameworks that are more suitable for traditional computer networks rather than wireless sensor networks (WSNs) which consist of heterogeneous settings with diverse devices and communication protocols. Subsequently, this study developed two candidate deep learning models, namely a convolutional neural network (CNN) and a long short-term memory (LSTM) network and presents evidence on their robustness and predictive power. Results have indicated that, unlike the CNN model, the LSTM model can quickly converge and offer high predictive power without the vigorous application of regularisation techniques. The proposed LSTM classification model obtained a remarkable 100% in detection rates and further reported 0% in false alarm and false negative rates. This study gives a broad overview of the current state of intrusion detection mechanisms for smart city ecosystems to guide future studies. The study also demonstrates that existing intrusion detection systems (IDSs) can be enhanced through the development of more robust and lightweight models that offer high detection rates and minimal false alarm rates to prevent security risks in smart city ecosystems to ensure sustainable and safe smart cities. , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-05
- Authors: Mfenguza, Wandisa
- Date: 2021-05
- Subjects: Ecosystem management , Smart cities
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22501 , vital:52382
- Description: Smart city systems are intended to enhance the lives of citizens through the design of systems that promote resource efficiency and the real-time provisioning of resources in cities. The benefits offered by smart cities include the use of internet of things (IoT) sensors to gather useful data such as power demand to inhibit blackouts and the average speed of vehicles to alleviate traffic congestion. Nonetheless, earlier studies have indicated a substantial increase in cyber-security issues due to the increase in the deployment of smart city ecosystems. Consequently, IoT cyber-security is recognised as an area that requires crucial scrutiny. This study begins by investigating the current state of intrusion detection in smart city ecosystems. Current intrusion detection frameworks lack the capability to operate under extremely limiting settings such as conditions of low processing power and fast response times. Moreover, the study also identifies that, despite intrusion detection being a highly researched thematic area, a plethora of previous studies tend to propose intrusion detection frameworks that are more suitable for traditional computer networks rather than wireless sensor networks (WSNs) which consist of heterogeneous settings with diverse devices and communication protocols. Subsequently, this study developed two candidate deep learning models, namely a convolutional neural network (CNN) and a long short-term memory (LSTM) network and presents evidence on their robustness and predictive power. Results have indicated that, unlike the CNN model, the LSTM model can quickly converge and offer high predictive power without the vigorous application of regularisation techniques. The proposed LSTM classification model obtained a remarkable 100% in detection rates and further reported 0% in false alarm and false negative rates. This study gives a broad overview of the current state of intrusion detection mechanisms for smart city ecosystems to guide future studies. The study also demonstrates that existing intrusion detection systems (IDSs) can be enhanced through the development of more robust and lightweight models that offer high detection rates and minimal false alarm rates to prevent security risks in smart city ecosystems to ensure sustainable and safe smart cities. , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-05
A causal analysis to investigate low production efficiency in the tyre manufacturing industry in South Africa
- Authors: Bruinders, Bramwill Bertram
- Date: 2021-04
- Subjects: Industrial efficiency , Production management , Lean manufacturing -- South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/50977 , vital:43177
- Description: The evolution of tyre manufacturing in South Africa went back to the early 1930s and matured technologically, becoming automated in the 1960s. The tyre industry in South Africa is worth approximately R30bn per annum and is one of the major supporting industries for domestic vehicle manufacturers. The local industry manufactures only 11 million tyres but can manufacture 18 million tyres per annum. The tyre industry thus plays a crucial role in South Africa’s economic development. Consumers are opting to buy cheaper imported tyres even though tyres are essential purchases. Therefore, the major tyre manufacturers must compete against an estimated 200 importers of various brands, most from China and Japan. The excess local capacity and increasing volume of imports put the local tyre manufacturers under severe pressure to grow their market share, reduce operational cost and achieve economies of scale. The study’s general objective was to conduct a root cause analysis of South African tyre manufacturers’ underlying issues resulting in low production efficiencies. This study used critical manufacturing principles such as traceability, knowledge of lean principles, lean implementation challenges, Total Quality Management, organisational buy-in, waste and rework and maintenance planning that constitute tools of lean practices. These principles provided an opportunity to adopt efficient manufacturing practices in tyre manufacturing companies and help organisations identify improvement areas. A questionnaire was developed and distributed electronically to 93 respondents employed in the tyre manufacturing industry in South Africa. The study addressed product traceability, investigated the quality measures in place, and examined the influence of the workforce’s attitude and morale on productivity, and determined management’s influence on decision-making. The key findings indicated that traceability, lean implementation challenges and organisational buy-in played a significant role in improving production efficiency. Recommendations were made to management to ensure that they lead by example and enhance these key constructs to foster their growth. , Thesis (MBA) -- Faculty of Business and Economic Sciences, Business Administration , 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Bruinders, Bramwill Bertram
- Date: 2021-04
- Subjects: Industrial efficiency , Production management , Lean manufacturing -- South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/50977 , vital:43177
- Description: The evolution of tyre manufacturing in South Africa went back to the early 1930s and matured technologically, becoming automated in the 1960s. The tyre industry in South Africa is worth approximately R30bn per annum and is one of the major supporting industries for domestic vehicle manufacturers. The local industry manufactures only 11 million tyres but can manufacture 18 million tyres per annum. The tyre industry thus plays a crucial role in South Africa’s economic development. Consumers are opting to buy cheaper imported tyres even though tyres are essential purchases. Therefore, the major tyre manufacturers must compete against an estimated 200 importers of various brands, most from China and Japan. The excess local capacity and increasing volume of imports put the local tyre manufacturers under severe pressure to grow their market share, reduce operational cost and achieve economies of scale. The study’s general objective was to conduct a root cause analysis of South African tyre manufacturers’ underlying issues resulting in low production efficiencies. This study used critical manufacturing principles such as traceability, knowledge of lean principles, lean implementation challenges, Total Quality Management, organisational buy-in, waste and rework and maintenance planning that constitute tools of lean practices. These principles provided an opportunity to adopt efficient manufacturing practices in tyre manufacturing companies and help organisations identify improvement areas. A questionnaire was developed and distributed electronically to 93 respondents employed in the tyre manufacturing industry in South Africa. The study addressed product traceability, investigated the quality measures in place, and examined the influence of the workforce’s attitude and morale on productivity, and determined management’s influence on decision-making. The key findings indicated that traceability, lean implementation challenges and organisational buy-in played a significant role in improving production efficiency. Recommendations were made to management to ensure that they lead by example and enhance these key constructs to foster their growth. , Thesis (MBA) -- Faculty of Business and Economic Sciences, Business Administration , 2021
- Full Text:
- Date Issued: 2021-04
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