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Investigating the effects of performance appraisal in the department of water and sanitation: a study of southern operations regional office
- Authors: Adonis Phelisa
- Date: 2019
- Subjects: Employees -- Rating of
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/40226 , vital:35983
- Description: This research examined the use of a personnel performance appraisal, a component of performance management system to evaluate employees at the Southern Operation Region Office of the Department of Water and Sanitation, Port Elizabeth and how this affects their performance. Writers in the available literature, contend that the objective of performance appraisal policy is to review work performance and provide feedback to facilitate measures and programmes to improve employee performance. Cascio and Aginis (2011:73) write that performance appraisal is a systematic description of individual or group job-relevant strengths and weaknesses as an important part of a performance management system. The study firstly analyses the effectiveness of performance appraisal in evaluating the management of the utilisation of resources. Secondly, the appropriateness of the tool in assessing the capacity of employees and contributing towards facilitating programmes and training to develop employee effectiveness. Thirdly, the study also examined the perception of employees on the use of performance appraisal as a management tool in the Department of Water and Sanitation Regional Operation Office. The study adopted a mainly qualitative methodological approach and purposively selected a sample of 30 employees at the Southern Operation Region Office of the Department of Water and Sanitation in Port Elizabeth who completed the questionnaire for the study. The choice of the qualitative research methodology is due to the fact that the approach is well suited to the collection of in-depth and perceptual information and for discovering underlying motivations and perceptions of the employees as respondents. The general employees at the area chosen for the study is one of a relatively young employee profile. The average age of the employees is about 28. The findings revealed that competence, assessment and development, communication and the adequate training which employees received based on the performance appraisal all had an impact on employee performance in Department of Water and Sanitation. Furthermore, factors, such as employee training, competence and communication could not be ignored since they were rated to a moderate extent v by the employees and it also contributed to employee performance. The study findings specifically highlight the importance of effective communication between the employer and the employees in order to improve employee performance appraisal processes. The study recommends a set of guidelines which could be used in improving the current performance appraisal policy and further boost employee performance.
- Full Text:
- Date Issued: 2019
- Authors: Adonis Phelisa
- Date: 2019
- Subjects: Employees -- Rating of
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/40226 , vital:35983
- Description: This research examined the use of a personnel performance appraisal, a component of performance management system to evaluate employees at the Southern Operation Region Office of the Department of Water and Sanitation, Port Elizabeth and how this affects their performance. Writers in the available literature, contend that the objective of performance appraisal policy is to review work performance and provide feedback to facilitate measures and programmes to improve employee performance. Cascio and Aginis (2011:73) write that performance appraisal is a systematic description of individual or group job-relevant strengths and weaknesses as an important part of a performance management system. The study firstly analyses the effectiveness of performance appraisal in evaluating the management of the utilisation of resources. Secondly, the appropriateness of the tool in assessing the capacity of employees and contributing towards facilitating programmes and training to develop employee effectiveness. Thirdly, the study also examined the perception of employees on the use of performance appraisal as a management tool in the Department of Water and Sanitation Regional Operation Office. The study adopted a mainly qualitative methodological approach and purposively selected a sample of 30 employees at the Southern Operation Region Office of the Department of Water and Sanitation in Port Elizabeth who completed the questionnaire for the study. The choice of the qualitative research methodology is due to the fact that the approach is well suited to the collection of in-depth and perceptual information and for discovering underlying motivations and perceptions of the employees as respondents. The general employees at the area chosen for the study is one of a relatively young employee profile. The average age of the employees is about 28. The findings revealed that competence, assessment and development, communication and the adequate training which employees received based on the performance appraisal all had an impact on employee performance in Department of Water and Sanitation. Furthermore, factors, such as employee training, competence and communication could not be ignored since they were rated to a moderate extent v by the employees and it also contributed to employee performance. The study findings specifically highlight the importance of effective communication between the employer and the employees in order to improve employee performance appraisal processes. The study recommends a set of guidelines which could be used in improving the current performance appraisal policy and further boost employee performance.
- Full Text:
- Date Issued: 2019
Why municipalities do not comply and implement expanded public works programmes: a case study of the Buffalo City Metropolitan Municipality in South Africa
- Jikwana, Mvumelwano Valithuba
- Authors: Jikwana, Mvumelwano Valithuba
- Date: 2018
- Subjects: Local government -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10948/22486 , vital:29975
- Description: The Expanded public works programme (EPWP) was a South African government initiative that was meant to fight poverty, reduce unemployment and develop skills for young people, women and people with disabilities. EPWP was to be implemented by the national, provincial and local governments in order to alleviate poverty and increase economic growth. The programme started with phase 1 in April 2004, where the objective was to create a minimum of 1 million job opportunities by March 2009. The target was achieved by the South African government, but many municipalities faced challenges as they were struggling to meet their own targets. EPWP phase 2 started in April 2009, where the target of creating 4.5 million work opportunities was set and it was meant to end in March 2014. Phase 3 was scheduled to start in April 2014 to March 2019. Buffalo City Metropolitan Municipality (BCMM) is a metropolitan municipality, which should implement EPWP, and it consists of the towns of East London, King Williams Town and Bisho. BCMM council accepted the EPWP structure in the financial year 2013/14, charging the Programme Manager to lead the EPWP unit, consisting of a single office to implement the programme. The municipality faced many challenges, in failing to meet the targets set by the National Department of Public Works (NDPW). These challenges include: the lack of political and administration commitment towards EPWP, lack of proper EPWP training and lack of accountability from Senior Management. Other challenges facing BCMM include: a lack of data capturers to consolidate EPWP information, lack of qualifies people to design and implement labour intensive projects and the shortage of staff within the EPWP unit, which was meant to support all departments. If the municipality can overcome all the challenges, the set targets can be met, unemployment can be reduced and poverty can be alleviated. There is an urgent need for the Mayor and Municipal Manager to commit themselves toward the full implementation of EPWP.
- Full Text:
- Date Issued: 2018
- Authors: Jikwana, Mvumelwano Valithuba
- Date: 2018
- Subjects: Local government -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10948/22486 , vital:29975
- Description: The Expanded public works programme (EPWP) was a South African government initiative that was meant to fight poverty, reduce unemployment and develop skills for young people, women and people with disabilities. EPWP was to be implemented by the national, provincial and local governments in order to alleviate poverty and increase economic growth. The programme started with phase 1 in April 2004, where the objective was to create a minimum of 1 million job opportunities by March 2009. The target was achieved by the South African government, but many municipalities faced challenges as they were struggling to meet their own targets. EPWP phase 2 started in April 2009, where the target of creating 4.5 million work opportunities was set and it was meant to end in March 2014. Phase 3 was scheduled to start in April 2014 to March 2019. Buffalo City Metropolitan Municipality (BCMM) is a metropolitan municipality, which should implement EPWP, and it consists of the towns of East London, King Williams Town and Bisho. BCMM council accepted the EPWP structure in the financial year 2013/14, charging the Programme Manager to lead the EPWP unit, consisting of a single office to implement the programme. The municipality faced many challenges, in failing to meet the targets set by the National Department of Public Works (NDPW). These challenges include: the lack of political and administration commitment towards EPWP, lack of proper EPWP training and lack of accountability from Senior Management. Other challenges facing BCMM include: a lack of data capturers to consolidate EPWP information, lack of qualifies people to design and implement labour intensive projects and the shortage of staff within the EPWP unit, which was meant to support all departments. If the municipality can overcome all the challenges, the set targets can be met, unemployment can be reduced and poverty can be alleviated. There is an urgent need for the Mayor and Municipal Manager to commit themselves toward the full implementation of EPWP.
- Full Text:
- Date Issued: 2018
Construction material logistics management: the case of North-Central Nigeria
- Authors: Alumbugu, Polycarp Olaku
- Date: 2019
- Subjects: Construction industry -- Nigeria
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/44556 , vital:38132
- Description: The Management of Construction Material Logistics Systems plays a significant role in meeting the goals of cost, quality and time to completion of a construction project. Fundamentally, it is accepted that any inefficiency in the delivery of construction material could lead to a time overrun and thus, a rise in construction costs. Therefore addressing the operational performance of logistics would have a positive impact on the goals of a construction project. The aim of this study was to investigate and evaluate the operational performance of material logistics in North-Central Nigeria as there is little specific research conducted on its effectiveness and efficiency. The methodology used included an extensive literature review and a field study conducted on ten quantitative approach that is rooted in the positivist paradigm, and purposive sampling techniques, was adopted. The descriptive method of data analysis was employed, and the findings and interpretations presented through graphs and images. Analysis of the findings led to the conclusion that material logistics did not operate as a system. There was almost no collaboration and integration of the logistics systems to create a synergistic interrelationship between functions in pursuit of higher overall effectiveness and efficiency. Improvement was needed in warehouse and transport operations and processes; technology and automation of logistics operations were absent, and delivery of material to customers was not effective. The implication was that the current materials logistics system did not meet the delivery goals of cost, quality and time of a construction project. The recommendations suggested included the adoption of the framework developed in this study. This would serve as a guide towards effective and efficient logistics management for material manufacturing firms, and for construction professionals.
- Full Text:
- Date Issued: 2019
- Authors: Alumbugu, Polycarp Olaku
- Date: 2019
- Subjects: Construction industry -- Nigeria
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/44556 , vital:38132
- Description: The Management of Construction Material Logistics Systems plays a significant role in meeting the goals of cost, quality and time to completion of a construction project. Fundamentally, it is accepted that any inefficiency in the delivery of construction material could lead to a time overrun and thus, a rise in construction costs. Therefore addressing the operational performance of logistics would have a positive impact on the goals of a construction project. The aim of this study was to investigate and evaluate the operational performance of material logistics in North-Central Nigeria as there is little specific research conducted on its effectiveness and efficiency. The methodology used included an extensive literature review and a field study conducted on ten quantitative approach that is rooted in the positivist paradigm, and purposive sampling techniques, was adopted. The descriptive method of data analysis was employed, and the findings and interpretations presented through graphs and images. Analysis of the findings led to the conclusion that material logistics did not operate as a system. There was almost no collaboration and integration of the logistics systems to create a synergistic interrelationship between functions in pursuit of higher overall effectiveness and efficiency. Improvement was needed in warehouse and transport operations and processes; technology and automation of logistics operations were absent, and delivery of material to customers was not effective. The implication was that the current materials logistics system did not meet the delivery goals of cost, quality and time of a construction project. The recommendations suggested included the adoption of the framework developed in this study. This would serve as a guide towards effective and efficient logistics management for material manufacturing firms, and for construction professionals.
- Full Text:
- Date Issued: 2019
Multi-drug resistant tuberculosis related adverse drug reactions: implementation of a documentation tool
- Authors: Cheng, Amber
- Date: 2019
- Subjects: Multi-drug resistant tuberculosis
- Language: English
- Type: Thesis , Masters , MPharm
- Identifier: http://hdl.handle.net/10948/44662 , vital:38151
- Description: Multi-drug resistant tuberculosis (MDR-TB) is an ever-growing problem in South Africa (SA). According to the literature, minimal documentation is done on adverse drug reactions (ADRs), specifically in the MDR-TB population. Co-administration of medications is typical for the treatment of drug resistant forms of TB, which leads to high incidences of ADRs during the treatment period, especially in patients with comorbid disease states. This before-and-after study investigated the impact of an intervention (education training presentation and implementation of a purpose-designed documentation tool) on the current documentation pattern in a public sector hospital in the Nelson Mandela Metropole. In order to measure the sustainability of the intervention, the study compared data from the pre-intervention phase to data collected from the post-intervention immediate phase and post-intervention delayed phase. Study results indicated that the intervention appeared to have had a positive effect on the frequency and variety of ADR documentation (2.1 and 1.3 fold increase, respectively) related to MDR-TB by the hospital staff of a public sector hospital, however, the positive change was not sustainable for longer than a three month period post intervention. It is recommended that factors such as: proper adoption; management; and additional resources are required to implement positive changes to documentation practices. Further studies need to be conducted in South Africa regarding the treatment of drug resistant tuberculosis, in order to establish safer treatment guidelines and more promising ADR reporting practices, which will ultimately improve patient care.
- Full Text:
- Date Issued: 2019
- Authors: Cheng, Amber
- Date: 2019
- Subjects: Multi-drug resistant tuberculosis
- Language: English
- Type: Thesis , Masters , MPharm
- Identifier: http://hdl.handle.net/10948/44662 , vital:38151
- Description: Multi-drug resistant tuberculosis (MDR-TB) is an ever-growing problem in South Africa (SA). According to the literature, minimal documentation is done on adverse drug reactions (ADRs), specifically in the MDR-TB population. Co-administration of medications is typical for the treatment of drug resistant forms of TB, which leads to high incidences of ADRs during the treatment period, especially in patients with comorbid disease states. This before-and-after study investigated the impact of an intervention (education training presentation and implementation of a purpose-designed documentation tool) on the current documentation pattern in a public sector hospital in the Nelson Mandela Metropole. In order to measure the sustainability of the intervention, the study compared data from the pre-intervention phase to data collected from the post-intervention immediate phase and post-intervention delayed phase. Study results indicated that the intervention appeared to have had a positive effect on the frequency and variety of ADR documentation (2.1 and 1.3 fold increase, respectively) related to MDR-TB by the hospital staff of a public sector hospital, however, the positive change was not sustainable for longer than a three month period post intervention. It is recommended that factors such as: proper adoption; management; and additional resources are required to implement positive changes to documentation practices. Further studies need to be conducted in South Africa regarding the treatment of drug resistant tuberculosis, in order to establish safer treatment guidelines and more promising ADR reporting practices, which will ultimately improve patient care.
- Full Text:
- Date Issued: 2019
The interaction between oil price shocks, currency volatility and stock market prices: evidence from South Africa
- Authors: Tshivhase, Mikovhe
- Date: 2019
- Subjects: Petroleum products -- Prices , Accounting and price fluctuations , Inflation (Finance) -- South Africa , Stock exchanges , Economics
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10948/43834 , vital:37051
- Description: Crude oil is an essential and strategic commodity in modern economies. Therefore, energy price fluctuations have the potential of affecting the economic welfare of a country. For instance, they have the potential to undermine the government’s attainment of its economic growth targets (National Treasury, 2016:2). The South African Reserve Bank (SARB) also considers oil price movements to be one of the major threats to currency volatility and the continued attainment of its inflation targets of about (3-6, per cent), as evidenced by numerous recent statements by its monetary policy committee (SARB, 2016:5-13). This study used co-integration tests to investigate the interaction between oil price shocks, exchange rates and stock market prices in South Africa over the period 1 January 2011 to 1 April 2018. The study employed the Johansen co-integration test. The results found no long run co-integration between oil prices, exchange rate and stock market prices. Therefore, this study adopted the VAR model for causality tests. Using the VAR model, this study found the existence of a unidirectional causality between stock prices and oil prices, with stock prices leading the oil prices changes. The all share index, resources and financials index were found to be significant variables to explain oil prices. This result is consistent with the business cycle view, which states that oil price fluctuations are mainly driven by demand factors. Furthermore, strong world output growth trends especially in emerging markets, could give rise to an upward surge in oil prices. The study also found that there is a weak correlation between stock price and exchange rate in South Africa. This is consistent with the asset approach. The findings of this study add to the already largely debated theories that seek to explain the relationship between the oil prices, exchange rates and stock market prices. The recommendation of this research is that, policy makers, researchers and investment bankers or fund managers who have interest or trade these financial instruments, may have to consider the role of stock market prices in the various sectors of the economy in their models for forecasting the path of the oil prices and the Rand/US Dollar exchange rate trend.
- Full Text:
- Date Issued: 2019
- Authors: Tshivhase, Mikovhe
- Date: 2019
- Subjects: Petroleum products -- Prices , Accounting and price fluctuations , Inflation (Finance) -- South Africa , Stock exchanges , Economics
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10948/43834 , vital:37051
- Description: Crude oil is an essential and strategic commodity in modern economies. Therefore, energy price fluctuations have the potential of affecting the economic welfare of a country. For instance, they have the potential to undermine the government’s attainment of its economic growth targets (National Treasury, 2016:2). The South African Reserve Bank (SARB) also considers oil price movements to be one of the major threats to currency volatility and the continued attainment of its inflation targets of about (3-6, per cent), as evidenced by numerous recent statements by its monetary policy committee (SARB, 2016:5-13). This study used co-integration tests to investigate the interaction between oil price shocks, exchange rates and stock market prices in South Africa over the period 1 January 2011 to 1 April 2018. The study employed the Johansen co-integration test. The results found no long run co-integration between oil prices, exchange rate and stock market prices. Therefore, this study adopted the VAR model for causality tests. Using the VAR model, this study found the existence of a unidirectional causality between stock prices and oil prices, with stock prices leading the oil prices changes. The all share index, resources and financials index were found to be significant variables to explain oil prices. This result is consistent with the business cycle view, which states that oil price fluctuations are mainly driven by demand factors. Furthermore, strong world output growth trends especially in emerging markets, could give rise to an upward surge in oil prices. The study also found that there is a weak correlation between stock price and exchange rate in South Africa. This is consistent with the asset approach. The findings of this study add to the already largely debated theories that seek to explain the relationship between the oil prices, exchange rates and stock market prices. The recommendation of this research is that, policy makers, researchers and investment bankers or fund managers who have interest or trade these financial instruments, may have to consider the role of stock market prices in the various sectors of the economy in their models for forecasting the path of the oil prices and the Rand/US Dollar exchange rate trend.
- Full Text:
- Date Issued: 2019
The relationship between conflict cycles and sustainable development goals
- Authors: Ngxeba, Zimkhitha Pamela
- Date: 2018
- Subjects: Sustainable development , Conflict management , Social conflict , Economic development -- Political aspects , Rural development
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/22846 , vital:30110
- Description: The objective of the study was to evaluate the relationship between conflict and the Sustainable Development Goals of the United Nations (UN) and the effect this relationship has on achieving these goals by the year 2030. The researcher gathered the data on this relationship from three communities within the Ngqushwa Municipality of the Eastern Cape, South Africa, using questionnaires and semi-structured interviews. The data collection tools that were used helped the researcher to develop a work plan that guided the type of information that should be collected with regards to the current situation in the three communities being studied. Three sample communities, namely Ndwayana, Ndlambe and Pikoli communities in the Ngqushwa Municipality of the Eastern Cape, South Africa were used. The first samples’ (Ndwayana community) responses to the survey, revealed that there are conflicts amongst the community members and amongst the community leadership. At Ndlambe, the response to the survey revealed that there is a divide between tribal authority and the community. In this village there are factions, with some of the people siding with the tribal authority and others who are against it. The third sample, which is from Pikoli community, however disclosed that conflict in their village is manageable and is mostly caused by outsiders. Based on the findings of the research, NGO’s and government have instituted development programmes in these villages, meaning that they are doing their part in trying to achieve the 2030 Sustainable Development Goals. However, efforts in some villages are rejected and conflicts still exist. This shows that there is a relationship between conflicts and sustainable development.
- Full Text:
- Date Issued: 2018
- Authors: Ngxeba, Zimkhitha Pamela
- Date: 2018
- Subjects: Sustainable development , Conflict management , Social conflict , Economic development -- Political aspects , Rural development
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/22846 , vital:30110
- Description: The objective of the study was to evaluate the relationship between conflict and the Sustainable Development Goals of the United Nations (UN) and the effect this relationship has on achieving these goals by the year 2030. The researcher gathered the data on this relationship from three communities within the Ngqushwa Municipality of the Eastern Cape, South Africa, using questionnaires and semi-structured interviews. The data collection tools that were used helped the researcher to develop a work plan that guided the type of information that should be collected with regards to the current situation in the three communities being studied. Three sample communities, namely Ndwayana, Ndlambe and Pikoli communities in the Ngqushwa Municipality of the Eastern Cape, South Africa were used. The first samples’ (Ndwayana community) responses to the survey, revealed that there are conflicts amongst the community members and amongst the community leadership. At Ndlambe, the response to the survey revealed that there is a divide between tribal authority and the community. In this village there are factions, with some of the people siding with the tribal authority and others who are against it. The third sample, which is from Pikoli community, however disclosed that conflict in their village is manageable and is mostly caused by outsiders. Based on the findings of the research, NGO’s and government have instituted development programmes in these villages, meaning that they are doing their part in trying to achieve the 2030 Sustainable Development Goals. However, efforts in some villages are rejected and conflicts still exist. This shows that there is a relationship between conflicts and sustainable development.
- Full Text:
- Date Issued: 2018
Levels of selected heavy metals in garden soil in Walmer Township and Wells Estate, Port Elizabeth
- Ogunfowora, Ebunoluwa Juliana
- Authors: Ogunfowora, Ebunoluwa Juliana
- Date: 2019
- Subjects: Environmental health -- South Africa -- Port Elizabeth , Environmental chemistry , Pollution -- Physiological effect
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/42990 , vital:36722
- Description: Heavy metals are naturally occurring elements that have high densities. Heavy metals have been found to have applications in various sectors such as the industrial, domestic, agricultural and medical sectors, thus resulting in environmental pollution which may pose a hazard to human health. Heavy metals such as arsenic, cadmium, manganese, lead and mercury rank among the priority metals that are of public health significance, and they are commonly found in garden soils. In this study, residential garden soils were sampled in dwelling sites in Wells Estate and Walmer Township, and analysed for mercury, cadmium, arsenic, manganese and lead. A cross sectional design was employed in this study. The research was carried out in two phases; the first phase involved soil sample collection, preparation and laboratory work for the determination of heavy metal concentrations. The second phase focused on the social aspect of the study population which included the use of a pre-approved questionnaire and face-to-face interviews for the collection of human health related information at each dwelling site where soil samples were collected. The research protocol was approved by the Health Sciences Faculty Postgraduate Studies Committees (FPGSC) of Nelson Mandela University. Garden soil from residential yards of Wells Estate (near an industrial site, ̴ 2 km) and Walmer Township (further away from the industrial site (̴ 22 km), but relatively close to Port Elizabeth airport, ̴ 2 km) were sampled over a total of six sampling sessions resulting in 100 soil samples. Fifty soil samples were collected in Wells Estate and fifty soil samples in Walmer Township during the month of May 2017. Surface soil samples were collected from the top 2 cm of the soil using a sterile stainless-steel spoon. In addition to the collection of soil samples, a visual inspection of the house was undertaken to collect information about the house characteristics, geographic location (GPS coordinates) and characteristics of the surrounding area. Soil samples were prepared for analysis by grinding and drying followed by heavy metal determination using an X-ray fluorescence (XRF) analyser (Bruker s1 TITAN Analyser, USA). A face-to-face questionnaire was administered to a suitable respondent at each dwelling site to obtain information related to health symptoms such as coughing, fever, chest pains, earache, sore throat, headaches, rapid breathing, sneezing, running/blocked nose, teary watery eyes, cancer, hypertension, heart diseases and mental illness. The mean concentrations of heavy metals were in the order manganese>lead>arsenic for both study sites. In Walmer Township soil samples, the mean concentrations of heavy metals determined were 154.8 mg/kg, 84.4 mg/kg and 5.4 mg/kg for manganese, lead, and arsenic, respectively. Mean concentrations of heavy metals as determined in Wells Estate were 322.2 mg/kg, 11.5 mg/kg, and 3.4 mg/kg for manganese, lead and arsenic, respectively. Manganese concentration across the study sites are below the guideline levels for USA (630 mg/kg) and South African (1500 mg/kg). About 2.0% of the sample exceeded the South African lead guideline level of 230 mg/kg, while 4.1% exceeded European lead level of 400 mg/kg in Walmer Township. Lead levels in Wells Estate were all below the South African, European and United States guideline levels. By contrast, 2.0% of the sample exceeded the South African arsenic guideline level of 48 mg/kg, 2.0% exceeded European arsenic guideline level of 50 mg/kg and 2.0% exceeded USA arsenic guideline level of 11 mg/kg in Walmer Township, while 2.0% exceeded USA arsenic guideline level of 11 mg/kg in Wells Estate. Mann Whitney U test showed statistically significant differences between lead levels (U=1527, p < 0.001) and manganese levels (U=2632, p < 0.001) across study sites. Soil manganese level showed significant association with age of house (crude OR: 0.34, 95% CI: 0.14-0.83, p =0.016). Using data obtained from the questionnaire, a multivariate logistic regression analysis was performed to examine the relationship between soil heavy metals and the various health outcomes. In Walmer Township, manganese showed association with dry cough (OR: 11.35, 95% CI: 1.08-119.20) and sneezing (OR: 11.30, 95% CI: 1.09-116.67). Manganese was also associated with wet cough (OR: 0.19 95% CI: 0.05-0.70), dry cough (OR: 0.22, 95% CI: 0.06-0.83) and watery eye (OR: 4.55, 95% CI: 1.01-20.58) in Wells Estate. Dry cough (OR: 0.31, 95% CI: 0.16-0.64), sneezing (OR: 2.18, 95% CI: 1.06-4.48) and watery eye adjusted (OR: 3.71, 95% CI: 1.63-8.48) were also associated with manganese in the total sample. Confounding factors such as overcrowding (adjusted OR = 2.23; 95% CI: 1.11-4.48) and air pollution (adjusted OR = 2.76; 95% CI:1.39-5.50), predicted wet cough and sneezing, respectively, across the total sample. Heavy metal concentration in most of the study dwellings of Walmer Township and Wells Estate were below the safe limit recommended by United States, European and South Africa soil reference levels. Nevertheless, we found a strong association between manganese and respiratory symptoms such as dry cough and sneezing in Walmer Township, as well as a strong association between manganese and watery eyes in Wells Estate. There was no evidence of associations between heavy metal exposure and gastrointestinal symptoms, chronic diseases and mental illness.
- Full Text:
- Date Issued: 2019
- Authors: Ogunfowora, Ebunoluwa Juliana
- Date: 2019
- Subjects: Environmental health -- South Africa -- Port Elizabeth , Environmental chemistry , Pollution -- Physiological effect
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/42990 , vital:36722
- Description: Heavy metals are naturally occurring elements that have high densities. Heavy metals have been found to have applications in various sectors such as the industrial, domestic, agricultural and medical sectors, thus resulting in environmental pollution which may pose a hazard to human health. Heavy metals such as arsenic, cadmium, manganese, lead and mercury rank among the priority metals that are of public health significance, and they are commonly found in garden soils. In this study, residential garden soils were sampled in dwelling sites in Wells Estate and Walmer Township, and analysed for mercury, cadmium, arsenic, manganese and lead. A cross sectional design was employed in this study. The research was carried out in two phases; the first phase involved soil sample collection, preparation and laboratory work for the determination of heavy metal concentrations. The second phase focused on the social aspect of the study population which included the use of a pre-approved questionnaire and face-to-face interviews for the collection of human health related information at each dwelling site where soil samples were collected. The research protocol was approved by the Health Sciences Faculty Postgraduate Studies Committees (FPGSC) of Nelson Mandela University. Garden soil from residential yards of Wells Estate (near an industrial site, ̴ 2 km) and Walmer Township (further away from the industrial site (̴ 22 km), but relatively close to Port Elizabeth airport, ̴ 2 km) were sampled over a total of six sampling sessions resulting in 100 soil samples. Fifty soil samples were collected in Wells Estate and fifty soil samples in Walmer Township during the month of May 2017. Surface soil samples were collected from the top 2 cm of the soil using a sterile stainless-steel spoon. In addition to the collection of soil samples, a visual inspection of the house was undertaken to collect information about the house characteristics, geographic location (GPS coordinates) and characteristics of the surrounding area. Soil samples were prepared for analysis by grinding and drying followed by heavy metal determination using an X-ray fluorescence (XRF) analyser (Bruker s1 TITAN Analyser, USA). A face-to-face questionnaire was administered to a suitable respondent at each dwelling site to obtain information related to health symptoms such as coughing, fever, chest pains, earache, sore throat, headaches, rapid breathing, sneezing, running/blocked nose, teary watery eyes, cancer, hypertension, heart diseases and mental illness. The mean concentrations of heavy metals were in the order manganese>lead>arsenic for both study sites. In Walmer Township soil samples, the mean concentrations of heavy metals determined were 154.8 mg/kg, 84.4 mg/kg and 5.4 mg/kg for manganese, lead, and arsenic, respectively. Mean concentrations of heavy metals as determined in Wells Estate were 322.2 mg/kg, 11.5 mg/kg, and 3.4 mg/kg for manganese, lead and arsenic, respectively. Manganese concentration across the study sites are below the guideline levels for USA (630 mg/kg) and South African (1500 mg/kg). About 2.0% of the sample exceeded the South African lead guideline level of 230 mg/kg, while 4.1% exceeded European lead level of 400 mg/kg in Walmer Township. Lead levels in Wells Estate were all below the South African, European and United States guideline levels. By contrast, 2.0% of the sample exceeded the South African arsenic guideline level of 48 mg/kg, 2.0% exceeded European arsenic guideline level of 50 mg/kg and 2.0% exceeded USA arsenic guideline level of 11 mg/kg in Walmer Township, while 2.0% exceeded USA arsenic guideline level of 11 mg/kg in Wells Estate. Mann Whitney U test showed statistically significant differences between lead levels (U=1527, p < 0.001) and manganese levels (U=2632, p < 0.001) across study sites. Soil manganese level showed significant association with age of house (crude OR: 0.34, 95% CI: 0.14-0.83, p =0.016). Using data obtained from the questionnaire, a multivariate logistic regression analysis was performed to examine the relationship between soil heavy metals and the various health outcomes. In Walmer Township, manganese showed association with dry cough (OR: 11.35, 95% CI: 1.08-119.20) and sneezing (OR: 11.30, 95% CI: 1.09-116.67). Manganese was also associated with wet cough (OR: 0.19 95% CI: 0.05-0.70), dry cough (OR: 0.22, 95% CI: 0.06-0.83) and watery eye (OR: 4.55, 95% CI: 1.01-20.58) in Wells Estate. Dry cough (OR: 0.31, 95% CI: 0.16-0.64), sneezing (OR: 2.18, 95% CI: 1.06-4.48) and watery eye adjusted (OR: 3.71, 95% CI: 1.63-8.48) were also associated with manganese in the total sample. Confounding factors such as overcrowding (adjusted OR = 2.23; 95% CI: 1.11-4.48) and air pollution (adjusted OR = 2.76; 95% CI:1.39-5.50), predicted wet cough and sneezing, respectively, across the total sample. Heavy metal concentration in most of the study dwellings of Walmer Township and Wells Estate were below the safe limit recommended by United States, European and South Africa soil reference levels. Nevertheless, we found a strong association between manganese and respiratory symptoms such as dry cough and sneezing in Walmer Township, as well as a strong association between manganese and watery eyes in Wells Estate. There was no evidence of associations between heavy metal exposure and gastrointestinal symptoms, chronic diseases and mental illness.
- Full Text:
- Date Issued: 2019
Investigation of the potential separation of isomers and related compounds using host compound (2R,3R)-(−)-2,3-dimethoxy-1,1,4,4-tetraphenylbutane-1,4-diol
- Authors: Pohl, Pieter Lourens
- Date: 2018
- Subjects: Chemistry, Organic , Clathrate compounds , Thermal analysis
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/23131 , vital:30432
- Description: In this study, we investigated the potential of a host compound, (2R,3R)-(−)-2,3-dimethoxy-1,1,4,4-tetraphenylbutane-1,4-diol (DMT), for use in the separation of isomers and related compounds using host-guest chemistry. The title molecule, DMT, is composed of a butane chain bearing hydroxyl moieties on the terminal carbons and methoxy moieties on the two internal, chiral carbon atoms. In addition, there are two phenyl rings on each of the terminal carbons. The synthesis of DMT was carried out by subjecting the diester of naturally-occurring optically active tartaric acid to a Grignard reaction employing phenylmagnesium bromide. Subsequent methylation of the secondary hydroxy groups with dimethyl sulfate afforded DMT. The resulting host molecule was investigated for its inclusion abilities by crystallizing with a number of potential aromatic, aliphatic and alicyclic guests such as toluene, aniline, nitrobenzene, anisole, cyclohexane, ethyl acetate and ethanol. Host:guest ratios were determined by means of 1H-NMR spectroscopy. Of the hosts investigated, DMT favoured a host:guest ratio of 2:1 for all included guests investigated. It complexed with most non-polycyclic aromatic guests as well as cyclohexane, cyclohexene and cyclohexanone. It was not able to include short chain or branched alcohols such as methanol, ethanol or 2-propanol, or other hetero-aliphatic or hetero- cyclic compounds such as diethyl ether, acetonitrile, morpholine or dioxane. Competition inclusion experiments were performed in which DMT was crystallized from equimolar and non-equimolar binary, ternary and quaternary mixtures of appropriate guests. The mother liquor mixtures and resultant crystals were subjected to GC-MS analysis in order to determine whether DMT showed discriminatory behaviour towards the guests from a mixture. It was observed that DMT was able to differentiate between related compounds, for example, the host preferred to include N,N-dimethylaniline compared with N-methylaniline and aniline. The host also discriminated against isomers, for example, p-xylene was preferentially included over o-xylene and m-xylene, while o-cresol was included in preference to p-cresol and m-cresol. Single crystal X-ray analysis was used to investigate the host–guest interactions responsible for guest inclusion, as well as to discern reasons for the host’s selective behaviour. X-ray data for the inclusion complexes indicated that each complex was isostructural, crystallizing in the monoclinic C2 crystal system. A pair of 1,3- and 2,4- intramolecular hydrogen bonds, as well as intramolecular non-classic hydrogen bonds between adjacent ortho-aromatic hydrogens and hydroxy moieties was a significant stabilizing factor for the geometry of the host. Guests were held within discrete cavities in the crystal lattice, and experienced only π–π stacking, CH–π interactions and other short contacts. Thermal analyses were used to determine the relative thermal stabilities of the complexes, and these data compared to the selectivity preference of DMT, obtained from the competition experiments, in order to assess the reasons for any discriminatory behaviour. Finally, Hirshfeld surface analysis data was used to determine if the thermal stability of the complexes was related to the number and type of interactions between host and guest.
- Full Text:
- Date Issued: 2018
- Authors: Pohl, Pieter Lourens
- Date: 2018
- Subjects: Chemistry, Organic , Clathrate compounds , Thermal analysis
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/23131 , vital:30432
- Description: In this study, we investigated the potential of a host compound, (2R,3R)-(−)-2,3-dimethoxy-1,1,4,4-tetraphenylbutane-1,4-diol (DMT), for use in the separation of isomers and related compounds using host-guest chemistry. The title molecule, DMT, is composed of a butane chain bearing hydroxyl moieties on the terminal carbons and methoxy moieties on the two internal, chiral carbon atoms. In addition, there are two phenyl rings on each of the terminal carbons. The synthesis of DMT was carried out by subjecting the diester of naturally-occurring optically active tartaric acid to a Grignard reaction employing phenylmagnesium bromide. Subsequent methylation of the secondary hydroxy groups with dimethyl sulfate afforded DMT. The resulting host molecule was investigated for its inclusion abilities by crystallizing with a number of potential aromatic, aliphatic and alicyclic guests such as toluene, aniline, nitrobenzene, anisole, cyclohexane, ethyl acetate and ethanol. Host:guest ratios were determined by means of 1H-NMR spectroscopy. Of the hosts investigated, DMT favoured a host:guest ratio of 2:1 for all included guests investigated. It complexed with most non-polycyclic aromatic guests as well as cyclohexane, cyclohexene and cyclohexanone. It was not able to include short chain or branched alcohols such as methanol, ethanol or 2-propanol, or other hetero-aliphatic or hetero- cyclic compounds such as diethyl ether, acetonitrile, morpholine or dioxane. Competition inclusion experiments were performed in which DMT was crystallized from equimolar and non-equimolar binary, ternary and quaternary mixtures of appropriate guests. The mother liquor mixtures and resultant crystals were subjected to GC-MS analysis in order to determine whether DMT showed discriminatory behaviour towards the guests from a mixture. It was observed that DMT was able to differentiate between related compounds, for example, the host preferred to include N,N-dimethylaniline compared with N-methylaniline and aniline. The host also discriminated against isomers, for example, p-xylene was preferentially included over o-xylene and m-xylene, while o-cresol was included in preference to p-cresol and m-cresol. Single crystal X-ray analysis was used to investigate the host–guest interactions responsible for guest inclusion, as well as to discern reasons for the host’s selective behaviour. X-ray data for the inclusion complexes indicated that each complex was isostructural, crystallizing in the monoclinic C2 crystal system. A pair of 1,3- and 2,4- intramolecular hydrogen bonds, as well as intramolecular non-classic hydrogen bonds between adjacent ortho-aromatic hydrogens and hydroxy moieties was a significant stabilizing factor for the geometry of the host. Guests were held within discrete cavities in the crystal lattice, and experienced only π–π stacking, CH–π interactions and other short contacts. Thermal analyses were used to determine the relative thermal stabilities of the complexes, and these data compared to the selectivity preference of DMT, obtained from the competition experiments, in order to assess the reasons for any discriminatory behaviour. Finally, Hirshfeld surface analysis data was used to determine if the thermal stability of the complexes was related to the number and type of interactions between host and guest.
- Full Text:
- Date Issued: 2018
Synthesis, characterization and application of novel acetals derived from Eucalyptus oil
- Date: 2018
- Subjects: Plasticizers , Eucalyptus citriodora
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/23548 , http://vital.seals.ac.za8080/10948/27452 , vital:30579
- Description: The aim of the project was to develop new bio-plasticizer compounds which could be incorporated into infant plastics. Plasticizers increase flexibility of plastic. These plasticizer compounds were derived from crude natural oils such as Eucalyptus citriodora oil and virgin coconut oil. A reagent which could be synthesized from Eucalyptus citriodora oil was, para-menthane-3,8-diol (PMD) which was present in a 60:40 ratio of cis and trans isomers of the diol. A green procedure to synthesize the diol, where an environmentally friendly catalyst, citric acid was used. Optimal conditions were 7% aqueous citric acid as the catalyst and 12 hour reaction which resulted in a citronellal conversion of 88.4 ± 0.80% and PMD selectivity of 75.4 ± 1.22%. As the diol was present in isomers, it was of interest to separate the cis and trans isomers for characterization purposes and later for subsequent individual isomer acetalization reactions. Yields obtained for the reaction for cis and trans-PMD were 51% and 36%, respectively. The kinetics for PMD synthesis from Eucalyptus citriodora oil was determined as second order with a rate constant of 0.0008hr-1 and Ea of 15.77kJ/mol. The isomers of para-menthane-3,8-diol could be separated from the isomeric mixture by solvent extraction at -78°C with n-heptane. Individual rod-shaped crystals could be isolated with this procedure and was characterized by X-ray crystallography techniques and identified as cis-para-menthane-3,8-diol. The trans-para-menthane-3,8-diol was successfully separated, however adequate crystals were not grown for X-ray crystallography analysis. Another method of isomer separation was investigated for PMD by the formation of a complex where anhydrous copper chloride could only form a novel complex with cis-para-menthane-3,8-diol. The trans isomer remained unreacted in the filtrate. The cis-para-menthane-3,8-diol isomer could be freed from the complex to yield pure cis isomer. Aldehydes could be synthesized from virgin coconut oil with carboxylic acid extraction procedures of the crude oil. Subsequent synthesis reactions from carboxylic acid to form aldehydes were performed and octanal (85% yield), decanal (88% yield), dodecanal (86% yield) and tetradecanal (14% yield) could be successfully synthesized as precursors to the novel acetalization reactions. Eight novel cyclic acetals with a characteristic 1,3-dioxine ring were successfully synthesized. However, diastereoisomers of cis-acetal and trans-acetal were present and required separation for characterization 1H-NMR, 13C-NMR, FT-IR, GC-MS and optical rotation techniques. The eight novel acetals were further characterized according to their physical properties such as there was no data available for these compounds. The following properties were determined: molecular mass, molecular formula, density, viscosity, boiling point, refractive index, enthalpy of vaporization, flash point, UV-VIS compatibility, solubility’s, colour and odour determination. Yields of up to 97% were obtained for these acetal compounds. The synthesis of acetals was optimized with batch reactions and optimum conditions were determined where eight catalysts were screened. These catalysts included: scandium triflate, Zeolite, sulphuric acid, p-toluene-sulfonic acid, Amberlyst 15®, Amberlyst 36®, Amberlite® IRA-120 and formic acid. Optimal conditions were with Amberlyst 15® catalyst, 50 minute reaction time at 65°C reaction temperature. The kinetics of the reaction was determined as zero order with a rate constant of 11.92 hr-1 and Ea of 0.050 kJ/mol. The acetalization reaction was evaluated using a UniQsis FlowSyn continuous flow reactor. One of the eight acetals (hexanal acetal) was used for the optimization study and the remaining acetals were evaluated with the optimum flow conditions. The reaction was improved with the use of continuous flow chemistry techniques by lowering of the optimum batch conditions. Various residence times (3.46-17.30 minutes) and temperature range (25-85°C) were studied to obtain optimum conditions. This process was efficient and low maintenance, which produced high acetal product selectivity of Optimum continuous flow conditions were determined at 55°C and 17.30 minute residence time with the flow rate of 0.1 ml/min. Heterogeneous catalysts such as Amberlyst 15® and Zeolite were screened and Amberlyst 15® determined as most favourable. The effect of Amberlyst 15® catalyst loading (0.5-2 g) was investigated over a temperature range of 25-85°C. Optimum catalyst loading was determined at 1g. The 8 compounds were tested for potential as plasticizers. This included mechanical, thermal, migratory and aesthetic testing. The novel acetals had to be compared to known plasticizers. Therefore, their plasticizer properties were compared to two commercial plasticizers: DBP and Eastman 168. As the compounds were derived from natural resources, they would be classified as bio-plasticizers if they exhibited such properties. Therefore, it was of interest to compare the novel compounds to a known bio-plasticizer: PMD-citronellal acetal. This compound was also present as a diastereoisomers mixture of cis and trans isomers. Therefore, diastereoisomers of the 8 acetals were separated as cis and trans isomers in high yields for plasticizer testing purposes. All 11 compounds (8 novel acetals, PMD-citronellal acetal, DBP and Eastman 168) were formulated in PVC to produce plastic films. As previously stated, isomers were present for the acetal compounds and these individual isomers were formulated into PVC formulations to evaluate if there was an effect of stereochemistry in the plastic films. Studies on this phenomenon were limited and therefore of interest. For isomeric plasticizer testing, 9 acetals (8 novel acetals and PMD-citronellal acetal) were used in the testing. Therefore 18 test compounds were formulated in PVC films for isomer plasticizer testing. The effect of increasing the compound amount in the PVC formulation was investigated in the range of 3-12% (w/w). The following tests were evaluated for all PVC test films: elongation, stress to fracture, glass transition temperature, leaching rate, flexibility, gloss and opacity. To validate the data and observations made, statistical validation models were developed to justify experimental design and trends observed. All novel compounds had plasticizer properties and one acetal compound was concluded as superior to DBP and Eastman 168, within the testing scope of the research. It was observed that higher molecular mass acetal compounds had increased plasticizer properties. Isomers for all acetal compounds were concluded to affect plasticizer properties differently and were highly significant. As the novel acetal compounds could be synthesized from natural crude resources, it was interesting to investigate if the synthesized acetals retained their anti-bacterial properties which the precursor oils possessed. Anti-bacterial testing of isomeric mixtures of C5-C12 acetal was investigated and compared to PMD-citronellal acetal and the two commercial plasticizers: DBP and Eastman 168. As the scope of the research focussed on bio-plasticizers for infant plastic products, test bacterial strains were chosen based on the pathogenic strains which cause diseases in babies. Six strains of bacteria were evaluated. It was of interest to evaluate the potency of the compounds by determining the minimum concentration of the compounds which would be potent enough to inhibit the bacteria. The commercial plasticizers inhibited no bacteria within the scope of the research. The acetals retained their anti-bacterial properties where C12 acetal was superior in 4/6 strains of bacteria and PMD-citronellal acetal was superior in 2/6 strains of bacteria. This research is novel and there are presently no data available on this. It was concluded that 8 new bio-plasticizers were synthesized, optimized and tested, within the scope of this research. These compounds were comparable to industry standards in all tests and possessed anti-bacterial properties which the industrial standards don’t possess.
- Full Text:
- Date Issued: 2018
- Date: 2018
- Subjects: Plasticizers , Eucalyptus citriodora
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/23548 , http://vital.seals.ac.za8080/10948/27452 , vital:30579
- Description: The aim of the project was to develop new bio-plasticizer compounds which could be incorporated into infant plastics. Plasticizers increase flexibility of plastic. These plasticizer compounds were derived from crude natural oils such as Eucalyptus citriodora oil and virgin coconut oil. A reagent which could be synthesized from Eucalyptus citriodora oil was, para-menthane-3,8-diol (PMD) which was present in a 60:40 ratio of cis and trans isomers of the diol. A green procedure to synthesize the diol, where an environmentally friendly catalyst, citric acid was used. Optimal conditions were 7% aqueous citric acid as the catalyst and 12 hour reaction which resulted in a citronellal conversion of 88.4 ± 0.80% and PMD selectivity of 75.4 ± 1.22%. As the diol was present in isomers, it was of interest to separate the cis and trans isomers for characterization purposes and later for subsequent individual isomer acetalization reactions. Yields obtained for the reaction for cis and trans-PMD were 51% and 36%, respectively. The kinetics for PMD synthesis from Eucalyptus citriodora oil was determined as second order with a rate constant of 0.0008hr-1 and Ea of 15.77kJ/mol. The isomers of para-menthane-3,8-diol could be separated from the isomeric mixture by solvent extraction at -78°C with n-heptane. Individual rod-shaped crystals could be isolated with this procedure and was characterized by X-ray crystallography techniques and identified as cis-para-menthane-3,8-diol. The trans-para-menthane-3,8-diol was successfully separated, however adequate crystals were not grown for X-ray crystallography analysis. Another method of isomer separation was investigated for PMD by the formation of a complex where anhydrous copper chloride could only form a novel complex with cis-para-menthane-3,8-diol. The trans isomer remained unreacted in the filtrate. The cis-para-menthane-3,8-diol isomer could be freed from the complex to yield pure cis isomer. Aldehydes could be synthesized from virgin coconut oil with carboxylic acid extraction procedures of the crude oil. Subsequent synthesis reactions from carboxylic acid to form aldehydes were performed and octanal (85% yield), decanal (88% yield), dodecanal (86% yield) and tetradecanal (14% yield) could be successfully synthesized as precursors to the novel acetalization reactions. Eight novel cyclic acetals with a characteristic 1,3-dioxine ring were successfully synthesized. However, diastereoisomers of cis-acetal and trans-acetal were present and required separation for characterization 1H-NMR, 13C-NMR, FT-IR, GC-MS and optical rotation techniques. The eight novel acetals were further characterized according to their physical properties such as there was no data available for these compounds. The following properties were determined: molecular mass, molecular formula, density, viscosity, boiling point, refractive index, enthalpy of vaporization, flash point, UV-VIS compatibility, solubility’s, colour and odour determination. Yields of up to 97% were obtained for these acetal compounds. The synthesis of acetals was optimized with batch reactions and optimum conditions were determined where eight catalysts were screened. These catalysts included: scandium triflate, Zeolite, sulphuric acid, p-toluene-sulfonic acid, Amberlyst 15®, Amberlyst 36®, Amberlite® IRA-120 and formic acid. Optimal conditions were with Amberlyst 15® catalyst, 50 minute reaction time at 65°C reaction temperature. The kinetics of the reaction was determined as zero order with a rate constant of 11.92 hr-1 and Ea of 0.050 kJ/mol. The acetalization reaction was evaluated using a UniQsis FlowSyn continuous flow reactor. One of the eight acetals (hexanal acetal) was used for the optimization study and the remaining acetals were evaluated with the optimum flow conditions. The reaction was improved with the use of continuous flow chemistry techniques by lowering of the optimum batch conditions. Various residence times (3.46-17.30 minutes) and temperature range (25-85°C) were studied to obtain optimum conditions. This process was efficient and low maintenance, which produced high acetal product selectivity of Optimum continuous flow conditions were determined at 55°C and 17.30 minute residence time with the flow rate of 0.1 ml/min. Heterogeneous catalysts such as Amberlyst 15® and Zeolite were screened and Amberlyst 15® determined as most favourable. The effect of Amberlyst 15® catalyst loading (0.5-2 g) was investigated over a temperature range of 25-85°C. Optimum catalyst loading was determined at 1g. The 8 compounds were tested for potential as plasticizers. This included mechanical, thermal, migratory and aesthetic testing. The novel acetals had to be compared to known plasticizers. Therefore, their plasticizer properties were compared to two commercial plasticizers: DBP and Eastman 168. As the compounds were derived from natural resources, they would be classified as bio-plasticizers if they exhibited such properties. Therefore, it was of interest to compare the novel compounds to a known bio-plasticizer: PMD-citronellal acetal. This compound was also present as a diastereoisomers mixture of cis and trans isomers. Therefore, diastereoisomers of the 8 acetals were separated as cis and trans isomers in high yields for plasticizer testing purposes. All 11 compounds (8 novel acetals, PMD-citronellal acetal, DBP and Eastman 168) were formulated in PVC to produce plastic films. As previously stated, isomers were present for the acetal compounds and these individual isomers were formulated into PVC formulations to evaluate if there was an effect of stereochemistry in the plastic films. Studies on this phenomenon were limited and therefore of interest. For isomeric plasticizer testing, 9 acetals (8 novel acetals and PMD-citronellal acetal) were used in the testing. Therefore 18 test compounds were formulated in PVC films for isomer plasticizer testing. The effect of increasing the compound amount in the PVC formulation was investigated in the range of 3-12% (w/w). The following tests were evaluated for all PVC test films: elongation, stress to fracture, glass transition temperature, leaching rate, flexibility, gloss and opacity. To validate the data and observations made, statistical validation models were developed to justify experimental design and trends observed. All novel compounds had plasticizer properties and one acetal compound was concluded as superior to DBP and Eastman 168, within the testing scope of the research. It was observed that higher molecular mass acetal compounds had increased plasticizer properties. Isomers for all acetal compounds were concluded to affect plasticizer properties differently and were highly significant. As the novel acetal compounds could be synthesized from natural crude resources, it was interesting to investigate if the synthesized acetals retained their anti-bacterial properties which the precursor oils possessed. Anti-bacterial testing of isomeric mixtures of C5-C12 acetal was investigated and compared to PMD-citronellal acetal and the two commercial plasticizers: DBP and Eastman 168. As the scope of the research focussed on bio-plasticizers for infant plastic products, test bacterial strains were chosen based on the pathogenic strains which cause diseases in babies. Six strains of bacteria were evaluated. It was of interest to evaluate the potency of the compounds by determining the minimum concentration of the compounds which would be potent enough to inhibit the bacteria. The commercial plasticizers inhibited no bacteria within the scope of the research. The acetals retained their anti-bacterial properties where C12 acetal was superior in 4/6 strains of bacteria and PMD-citronellal acetal was superior in 2/6 strains of bacteria. This research is novel and there are presently no data available on this. It was concluded that 8 new bio-plasticizers were synthesized, optimized and tested, within the scope of this research. These compounds were comparable to industry standards in all tests and possessed anti-bacterial properties which the industrial standards don’t possess.
- Full Text:
- Date Issued: 2018
Residents’ perspectives on township tourism in Mondesa, Swakopmund, Namibia
- Auala, Lovisa Sisco Ndapanda
- Authors: Auala, Lovisa Sisco Ndapanda
- Date: 2019
- Subjects: Tourism — Namibia
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/42448 , vital:36661
- Description: Township tourism is regarded as one of the fastest growing tourist activities in Namibia (Buning, Legant, Schauwinhold, Steinbrink & Subenguth, 2016:14). This research study presents an exploratory inquiry that seeks an in-depth understanding of residents’perspectives on township tourism in Mondesa, Swakopmund, Namibia.In order to conceptualise the extent to which the residents’needs are being met through the benefits derived from township tourism. The residents’ perspectives on township tourism in Mondesa areexplored with respect to the benefits and costs derived from township tourism, participation in township tourism, and interaction with tourist during a township tour and consultation on township tourismwhich forms part of the research questions ofthe study. By applying the Social Exchange Theory (SET) in this study, the relationships between the variables that influence the residents perceived benefit and costs of township tourism in Mondesa are explored further in depth in combination with Pretty’s Typology of participation and Scheyne’s typology of community empowerment in tourism (Ap, 1992: 668; Mason, 2003:119; Sharpley and Telfer, 2002:152;Cooper, Fletcher, Gilbert & Wanhill, 1993:91).These variables are namely; social, economic, psychological, environmental, cultural, Manipulative, passive, educational and political factors. They form part of the conceptual framework of the study.This study followed a qualitative research approachandmultiple data sources were collected including semi-structured interviews with residents from Mondesa:these included residents involved in township tourism and those not involved in township tourism. To triangulate the data collection, semi-structured interviews were conducted with representatives from tourism industry and government bodies related to townshiptourism. Data analysis was done through the facilitation of Atlas tiaqualitative data analysis software and deductive codes were established from the literature(variables from the conceptual framework)and themes were developed from the research questions.The findings indicate that residents who are not involved in township tourism arenot influenced by the benefit and cost equation of the social exchange theory (Andriotis, 2005:69). Therefore residents not involved in township tourism are positive about tourism irrespective of whether they benefit directly from financial gain through tourism. The findingsfurtheremphasis oncommunity benefitsfrom township tourism being as important, than individual benefits. This study also provides knowledge that meaningful interaction between tourist and residents has the ability to reduce the apartheid paradigm of racial division and discrimination, which was the basis of the formation of townships.Residents’ misconception about white people are changed due to their personal interaction and cultural exchange with white tourist during a township tour. Anothersignificant findings to emerge from this study is the ability for township tourism to transform the lives of residents living in townships through the intrinsic benefits derived from township tourism. Township tourism has the ability to contribute to positive human exchange through interaction between residents and tourists. By sharing a positive cultural exchange, strong relationships are built between the tourists and residents, which may provide long term sustainability of township tourism. The positive personal transformational effect on residents through interaction with tourists is contributing to residents’ socio-economic well-being. Therefore township tourism has the ability to quantitatively and qualitatively address the alleviationof poverty in townshipsand fostering understanding and mutual respect among peoples of the world.The studyconcluded with a framework of guidelines toaid key stakeholders in the development and planning of township tourism and encourages the practice of sustainable tourism in townships.
- Full Text:
- Date Issued: 2019
- Authors: Auala, Lovisa Sisco Ndapanda
- Date: 2019
- Subjects: Tourism — Namibia
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/42448 , vital:36661
- Description: Township tourism is regarded as one of the fastest growing tourist activities in Namibia (Buning, Legant, Schauwinhold, Steinbrink & Subenguth, 2016:14). This research study presents an exploratory inquiry that seeks an in-depth understanding of residents’perspectives on township tourism in Mondesa, Swakopmund, Namibia.In order to conceptualise the extent to which the residents’needs are being met through the benefits derived from township tourism. The residents’ perspectives on township tourism in Mondesa areexplored with respect to the benefits and costs derived from township tourism, participation in township tourism, and interaction with tourist during a township tour and consultation on township tourismwhich forms part of the research questions ofthe study. By applying the Social Exchange Theory (SET) in this study, the relationships between the variables that influence the residents perceived benefit and costs of township tourism in Mondesa are explored further in depth in combination with Pretty’s Typology of participation and Scheyne’s typology of community empowerment in tourism (Ap, 1992: 668; Mason, 2003:119; Sharpley and Telfer, 2002:152;Cooper, Fletcher, Gilbert & Wanhill, 1993:91).These variables are namely; social, economic, psychological, environmental, cultural, Manipulative, passive, educational and political factors. They form part of the conceptual framework of the study.This study followed a qualitative research approachandmultiple data sources were collected including semi-structured interviews with residents from Mondesa:these included residents involved in township tourism and those not involved in township tourism. To triangulate the data collection, semi-structured interviews were conducted with representatives from tourism industry and government bodies related to townshiptourism. Data analysis was done through the facilitation of Atlas tiaqualitative data analysis software and deductive codes were established from the literature(variables from the conceptual framework)and themes were developed from the research questions.The findings indicate that residents who are not involved in township tourism arenot influenced by the benefit and cost equation of the social exchange theory (Andriotis, 2005:69). Therefore residents not involved in township tourism are positive about tourism irrespective of whether they benefit directly from financial gain through tourism. The findingsfurtheremphasis oncommunity benefitsfrom township tourism being as important, than individual benefits. This study also provides knowledge that meaningful interaction between tourist and residents has the ability to reduce the apartheid paradigm of racial division and discrimination, which was the basis of the formation of townships.Residents’ misconception about white people are changed due to their personal interaction and cultural exchange with white tourist during a township tour. Anothersignificant findings to emerge from this study is the ability for township tourism to transform the lives of residents living in townships through the intrinsic benefits derived from township tourism. Township tourism has the ability to contribute to positive human exchange through interaction between residents and tourists. By sharing a positive cultural exchange, strong relationships are built between the tourists and residents, which may provide long term sustainability of township tourism. The positive personal transformational effect on residents through interaction with tourists is contributing to residents’ socio-economic well-being. Therefore township tourism has the ability to quantitatively and qualitatively address the alleviationof poverty in townshipsand fostering understanding and mutual respect among peoples of the world.The studyconcluded with a framework of guidelines toaid key stakeholders in the development and planning of township tourism and encourages the practice of sustainable tourism in townships.
- Full Text:
- Date Issued: 2019
Design of metal ion-selective reagents for recovery of precious metals
- Authors: Moleko-Boyce, Pulleng
- Date: 2019
- Subjects: Bioinorganic chemistry , Metal complexes , Speciation (Chemistry)
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/42510 , vital:36664
- Description: The study is divided into two sections; namely, (1) the design of rhodium(III) specific chelating ligands (tridentate bis-benzimidazole derivatives), and (2) the development of iridium(IV)-specific quaternary diammonium cations with electron donating and electron withdrawing groups. Bis-benzimidazole chelating ligands used were bis((1H-benzimidazol-2-yl)methyl)amine (NNN1), bis((1H-benzimidazol-2-yl)ethyl)amine (NNN2), bis((1H-benzimidazol-2-yl)methyl)sulfide (NSN1) and bis((1H-benzimidazol-2-yl)ethyl)sulfide (NSN2). Quaternary diammonium cations used were tetramethylbenzyl-1,10-diammonium chloride (QuatDMDAMeBnz), tetrabenzyl-1,10-diammonium chloride (QuatDMDABnz), tetratrifluoromethylbenzyl-1,10-diammonium chloride (QuatDMDACF3Bnz) and tetranitrobenzyl-1,10-diammonium chloride (QuatDMDANO2Bnz). For both studies, polyvinylbenzylchloride (PVBC) nanofibers were used as support material. The PVBC nanofibers which were functionalised with bis-benzimidazole derivatives and quaternary diammonium cations, respectively, were investigated for the selectivity for Rh(III) over Ir(III), Pt(II), Pd(II) and Ni(II), and for separation of Ir(IV) from Rh(III), respectively. The sorbent materials were characterised by FTIR, SEM, BET surface area, TGA, EDS and elemental analysis, and the results showed that the functionalization of the sorbent materials was successful.The efficiency of bis-benzimidazole derivatives and quaternary diammonium cations, respectively, were investigated in a column study under dynamic flow adsorption conditions. The adsorption kinetics and isotherms were investigated under batch conditions and fitted on pseudo-first-order and pseudo-second-order model, and Freundlich and Langmuir isotherm, respectively. It was observed that the bis-benzimidazole derivatives showed uptake of [RhCl3(H2O)3], and the loading capacities were observed in the following order; NSN1 (181.06 mg/g) > NSN2 (148.55 mg/g) > NNN1 (131.88 mg/g) > NNN2 (75.87 mg/g). The bis-benzimidazole derivatives preference for metal ions was further investigated with a multi-element solution containing Rh(III), Ir(III), Pt(II), Pd(II) and Ni(II). The bis-benzimidazole derivatives showed the following order of loading capacity: NSN1 (47.28 mg/g) > NSN2 (23.89 mg/g) > NNN1 (17.47 mg/g) > NNN2 (14.91 mg/g) for Rh(III); NSN2 (10.64 mg/g) > NNN2 (6.84 mg/g) > NSN1 (5.74 mg/g) > NNN1 (5.02 mg/g) for Ir(III); NNN2 (33.96 mg/g) > NSN1 (30.95 mg/g) > NSN2 (19.95 mg/g) > NNN1 (14.92 mg/g) for Pt(II); NNN1 (47.94 mg/g) > NNN2 (28.90 mg/g) > NSN1 (16.22 mg/g) > NSN2 (15.83 mg/g) for Pd(II). Bis-benzimidazole derivatives showed no uptake of nickel(II) under these conditions. It was observed the ligand-selectivity order for Rh(III) was similar in both single-element and multi-element studies. This order showed that the bis-benzimidazoles containing a sulfur atom showed a high preference for rhodium(III) compared to Pt(II) which had a high preference for NNN2 as well as Pd(II) which had a high preference for NNN1. Ir(III) generally had a lower preference for the ligands presumably due to its higher kinetic inertness compared with Rh(III). Column sorption of [IrCl6]2- and [RhCl5(H2O)]2- on nanofibers functionalized with diammonium cations was carried out and the loading capacities of [IrCl6]2- were obtained. [RhCl5(H2O)]2- was not adsorbed by the sorbent materials while [IrCl6]2- was loaded onto the column. The loading capacities of [IrCl6]2- with the quaternary diammonium sorbent materials increased in the order of F-QuatDMDAMeBnz (60.29 mg/g) < F-QuatDMDABnz (67.61 mg/g) < F-QuatDMDACF3Bnz (107.59 mg/g) < F-QuatDMDANO2Bnz (140.47 mg/g). The loading capacity for Ir(IV) with quaternary diammonium cationic nanofibers increased with an increase in the electron-withdrawing nature of the quaternizing group. The charge delocalizing ability of the nitrobenzyl group resulted in the best interaction of the diammonium cation with [IrCl6]2-. Batch equilibrium studies were carried out to assess the efficiency of bis-benzimidazole chelating derivatives as adsorbents using a multi-metal solution (Rh(III), Ir(III), Pt(II), Pd(II) and Ni(II)) in 0.5 M HCl. The efficiency of the quaternary diammonium cations was tested using a binary metal solution (Ir(IV) and Rh(III)) in 6 M HCl. The isothermal batch adsorption studies of a multi-metal solution with bis-benzimidazoles derivatives fitted the Langmuir isotherm model which confirmed monolayer adsorption onto a homogeneous surface. The Langmuir isotherm parameter (qe (mg/g)), using functionalized nanofibers, showed the order of NNN2 (128.21 mg/g) > NSN1 (99.01 mg/g) > NSN2 (91.74 mg/g) > NNN1 (84.03 mg/g) for Pt(II); NNN1 (66.23 mg/g) > NNN2 (5.89 mg/g) > NSN1 (1.40 mg/g) > NSN2 (0.59 mg/g) for Pd(II); NSN2 (10.64 mg/g) > NNN2 (6.84 mg/g) > NSN1 (5.74 mg/g) > NNN1 (5.02 mg/g) for Ir(III); NSN1 (140.85 mg/g) > NSN2 (109.89 mg/g) > NNN1 (104.17 mg/g) > NNN2 (91.74 mg/g) for Rh(III). The pseudo-first-order kinetics model was found to be the best fit to describe the adsorption kinetics of all metal ions onto all the sorbent materials. K1 (min-1) value in pseudo-first-order kinetics showed the same order of adsorption as observed in the Langmuir isotherms. The isothermal batch adsorption studies of [IrCl6]2- and [RhCl5(H2O)]2- with quaternary diammonium cations fitted the Freundlich isotherm model and confirmed to be effective for multiple-layered adsorption onto a heterogeneous surface. The Freundlich isotherm parameter (kf (mg/g)) using functionalized quaternary diammonium cationic nanofibers increased in the order of F-QuatDMDANO2Bnz (794.33 mg/g) > F-QuatDMDACF3Bnz (185.35 mg/g) > F-QuatDMDABnz (156.32 mg/g) > F-QuatDMDAMeBnz (112.46 mg/g) for Ir(IV) uptake. F-QuatDMDANO2Bnz resin showed the highest adsorption than that of F-QuatDMDAMeBnz, F-QuatDMDABnz and F-QuatDMDACF3Bnz and this order is similar to what was observed in column studies. The quaternary diammonium cations were shown to have the highest adsorption capacity for Ir(IV) compared with Rh(III). The adsorption of Rh(III) was also observed to increase in the order of F-QuatDMDANO2Bnz (177.83 mg/g) > F-QuatDMDACF3Bnz (40.37 mg/g) > F-QuatDMDABnz (36.98 mg/g) > F-QuatDMDAMeBnz (12.71 mg/g). The pseudo-second-order kinetic model was found to be the best fit to describe the adsorption kinetics of both metal ions onto all the sorbent materials. K2 (g.mg-1min-1) value in pseudo-second-order kinetics showed the same order of adsorption as observed in the Freundlich isotherms. The adsorption studies showed adsorption takes place via chemisorption process. This thesis presents PGMs and iridium-specific materials that could be applied in solutions of secondary PGMs sources containing rhodium, platinum and palladium with bis-benzimidazoles as well as in feed solutions from ore processing with diammonium cations for iridium recovery.
- Full Text:
- Date Issued: 2019
- Authors: Moleko-Boyce, Pulleng
- Date: 2019
- Subjects: Bioinorganic chemistry , Metal complexes , Speciation (Chemistry)
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/42510 , vital:36664
- Description: The study is divided into two sections; namely, (1) the design of rhodium(III) specific chelating ligands (tridentate bis-benzimidazole derivatives), and (2) the development of iridium(IV)-specific quaternary diammonium cations with electron donating and electron withdrawing groups. Bis-benzimidazole chelating ligands used were bis((1H-benzimidazol-2-yl)methyl)amine (NNN1), bis((1H-benzimidazol-2-yl)ethyl)amine (NNN2), bis((1H-benzimidazol-2-yl)methyl)sulfide (NSN1) and bis((1H-benzimidazol-2-yl)ethyl)sulfide (NSN2). Quaternary diammonium cations used were tetramethylbenzyl-1,10-diammonium chloride (QuatDMDAMeBnz), tetrabenzyl-1,10-diammonium chloride (QuatDMDABnz), tetratrifluoromethylbenzyl-1,10-diammonium chloride (QuatDMDACF3Bnz) and tetranitrobenzyl-1,10-diammonium chloride (QuatDMDANO2Bnz). For both studies, polyvinylbenzylchloride (PVBC) nanofibers were used as support material. The PVBC nanofibers which were functionalised with bis-benzimidazole derivatives and quaternary diammonium cations, respectively, were investigated for the selectivity for Rh(III) over Ir(III), Pt(II), Pd(II) and Ni(II), and for separation of Ir(IV) from Rh(III), respectively. The sorbent materials were characterised by FTIR, SEM, BET surface area, TGA, EDS and elemental analysis, and the results showed that the functionalization of the sorbent materials was successful.The efficiency of bis-benzimidazole derivatives and quaternary diammonium cations, respectively, were investigated in a column study under dynamic flow adsorption conditions. The adsorption kinetics and isotherms were investigated under batch conditions and fitted on pseudo-first-order and pseudo-second-order model, and Freundlich and Langmuir isotherm, respectively. It was observed that the bis-benzimidazole derivatives showed uptake of [RhCl3(H2O)3], and the loading capacities were observed in the following order; NSN1 (181.06 mg/g) > NSN2 (148.55 mg/g) > NNN1 (131.88 mg/g) > NNN2 (75.87 mg/g). The bis-benzimidazole derivatives preference for metal ions was further investigated with a multi-element solution containing Rh(III), Ir(III), Pt(II), Pd(II) and Ni(II). The bis-benzimidazole derivatives showed the following order of loading capacity: NSN1 (47.28 mg/g) > NSN2 (23.89 mg/g) > NNN1 (17.47 mg/g) > NNN2 (14.91 mg/g) for Rh(III); NSN2 (10.64 mg/g) > NNN2 (6.84 mg/g) > NSN1 (5.74 mg/g) > NNN1 (5.02 mg/g) for Ir(III); NNN2 (33.96 mg/g) > NSN1 (30.95 mg/g) > NSN2 (19.95 mg/g) > NNN1 (14.92 mg/g) for Pt(II); NNN1 (47.94 mg/g) > NNN2 (28.90 mg/g) > NSN1 (16.22 mg/g) > NSN2 (15.83 mg/g) for Pd(II). Bis-benzimidazole derivatives showed no uptake of nickel(II) under these conditions. It was observed the ligand-selectivity order for Rh(III) was similar in both single-element and multi-element studies. This order showed that the bis-benzimidazoles containing a sulfur atom showed a high preference for rhodium(III) compared to Pt(II) which had a high preference for NNN2 as well as Pd(II) which had a high preference for NNN1. Ir(III) generally had a lower preference for the ligands presumably due to its higher kinetic inertness compared with Rh(III). Column sorption of [IrCl6]2- and [RhCl5(H2O)]2- on nanofibers functionalized with diammonium cations was carried out and the loading capacities of [IrCl6]2- were obtained. [RhCl5(H2O)]2- was not adsorbed by the sorbent materials while [IrCl6]2- was loaded onto the column. The loading capacities of [IrCl6]2- with the quaternary diammonium sorbent materials increased in the order of F-QuatDMDAMeBnz (60.29 mg/g) < F-QuatDMDABnz (67.61 mg/g) < F-QuatDMDACF3Bnz (107.59 mg/g) < F-QuatDMDANO2Bnz (140.47 mg/g). The loading capacity for Ir(IV) with quaternary diammonium cationic nanofibers increased with an increase in the electron-withdrawing nature of the quaternizing group. The charge delocalizing ability of the nitrobenzyl group resulted in the best interaction of the diammonium cation with [IrCl6]2-. Batch equilibrium studies were carried out to assess the efficiency of bis-benzimidazole chelating derivatives as adsorbents using a multi-metal solution (Rh(III), Ir(III), Pt(II), Pd(II) and Ni(II)) in 0.5 M HCl. The efficiency of the quaternary diammonium cations was tested using a binary metal solution (Ir(IV) and Rh(III)) in 6 M HCl. The isothermal batch adsorption studies of a multi-metal solution with bis-benzimidazoles derivatives fitted the Langmuir isotherm model which confirmed monolayer adsorption onto a homogeneous surface. The Langmuir isotherm parameter (qe (mg/g)), using functionalized nanofibers, showed the order of NNN2 (128.21 mg/g) > NSN1 (99.01 mg/g) > NSN2 (91.74 mg/g) > NNN1 (84.03 mg/g) for Pt(II); NNN1 (66.23 mg/g) > NNN2 (5.89 mg/g) > NSN1 (1.40 mg/g) > NSN2 (0.59 mg/g) for Pd(II); NSN2 (10.64 mg/g) > NNN2 (6.84 mg/g) > NSN1 (5.74 mg/g) > NNN1 (5.02 mg/g) for Ir(III); NSN1 (140.85 mg/g) > NSN2 (109.89 mg/g) > NNN1 (104.17 mg/g) > NNN2 (91.74 mg/g) for Rh(III). The pseudo-first-order kinetics model was found to be the best fit to describe the adsorption kinetics of all metal ions onto all the sorbent materials. K1 (min-1) value in pseudo-first-order kinetics showed the same order of adsorption as observed in the Langmuir isotherms. The isothermal batch adsorption studies of [IrCl6]2- and [RhCl5(H2O)]2- with quaternary diammonium cations fitted the Freundlich isotherm model and confirmed to be effective for multiple-layered adsorption onto a heterogeneous surface. The Freundlich isotherm parameter (kf (mg/g)) using functionalized quaternary diammonium cationic nanofibers increased in the order of F-QuatDMDANO2Bnz (794.33 mg/g) > F-QuatDMDACF3Bnz (185.35 mg/g) > F-QuatDMDABnz (156.32 mg/g) > F-QuatDMDAMeBnz (112.46 mg/g) for Ir(IV) uptake. F-QuatDMDANO2Bnz resin showed the highest adsorption than that of F-QuatDMDAMeBnz, F-QuatDMDABnz and F-QuatDMDACF3Bnz and this order is similar to what was observed in column studies. The quaternary diammonium cations were shown to have the highest adsorption capacity for Ir(IV) compared with Rh(III). The adsorption of Rh(III) was also observed to increase in the order of F-QuatDMDANO2Bnz (177.83 mg/g) > F-QuatDMDACF3Bnz (40.37 mg/g) > F-QuatDMDABnz (36.98 mg/g) > F-QuatDMDAMeBnz (12.71 mg/g). The pseudo-second-order kinetic model was found to be the best fit to describe the adsorption kinetics of both metal ions onto all the sorbent materials. K2 (g.mg-1min-1) value in pseudo-second-order kinetics showed the same order of adsorption as observed in the Freundlich isotherms. The adsorption studies showed adsorption takes place via chemisorption process. This thesis presents PGMs and iridium-specific materials that could be applied in solutions of secondary PGMs sources containing rhodium, platinum and palladium with bis-benzimidazoles as well as in feed solutions from ore processing with diammonium cations for iridium recovery.
- Full Text:
- Date Issued: 2019
The non-restoration of land: scope and ambit of section 34 of the restitution of land rights act
- Date: 2018
- Subjects: Restitution -- South Africa , Land reform -- South Africa , Land reform -- Government policy -- South Africa
- Type: Thesis , Masters , LLM
- Identifier: http://hdl.handle.net/10948/23869 , http://vital.seals.ac.za8080/10948/29168 , vital:30636
- Description: The land question is an emotionally-laden issue for all people across the racial divide in South Africa, albeit for different reasons land serves a variety of human needs: it creates a sense of identity, it creates wealth, imbues the owner with human dignity; it is also an axis for social cohesion and it is key to the exercise of economic and political power. South Africa is still in the throes of withdrawal symptoms as a result of a checkered colonial past, when it comes to the issue of the land. Having been dispossessed of their ancestral land by the country’s former colonial rulers, the majority of South Africans now have the yearning that the wrongs of the past be addressed, and that justice be done. Having repealed the Apartheid laws which had provided for the calculated systematic dispossession of the land and rights in land of the majority of citizens of South Africa, was and is not sufficient. The Constitution of the Republic of South Africa, being negotiated Constitution, which is internationally lauded, provides for a three-pronged land reform programme, namely restitution, redistribution and tenure reform. The focus of this dissertation is on the restitution leg and more specifically the issue of non-restoration which is provided for in section 34 of the RLRA 22 of 1994, as amended (the RLRA). Section 34 specifically provides that in some instances, land will not be restored to claimants even though they may satisfy the requirements for a valid claim provided for in section 25(7) of the Constitution and section 2 of the RLRA. It is submitted that it is necessary to acquire an understanding of the requirements for a restitution claim even though the land claimed may be removed from the process before a claim has been finalised, since the claimants will still have to satisfy the abovementioned requirements after a particular parcel of land or right in land has been removed from the process by a court of law. In other words, the court has made an order of non-restoration even before the claim has been finalised. Such an application for non-restoration of the land in question or rights in relation to land, may be brought by any national, provincial or local government body, in terms of section 34(1) of the RLRA, and the court will then grant such application provided the applicant has convinced the court that the two threshold requirements listed in section 34(6) have been satisfied. This dissertation outlines a number of cases which serve as practical examples of how the courts dealt with the threshold requirements contained in section 34(6). Included in this examination is the courts’ interpretation of the concepts “public interest” and “substantial prejudice”, which are contained in the requirements listed in section 34(6). This dissertation furthermore sought to determine whether the courts have adopted a broad or narrow approach to these concepts and whether the approach that the courts have adopted strikes an appropriate balance between the constitutional right to restitution and the goals underlying section 34. What is evident from the research is that, apart from the Constitutional Court in the KwaLindile case, none of the other courts provided a substantive definition of the concept “public interest”, but rather chose to refer to academic writings. It is submitted that the courts by and large appear to overlook the fact that the restitution of land and rights in land and arguably, the restoration of land, are in the public interest. While the courts do acknowledge the claimants’ rights to restitution, they downplay the importance of restoration since they argue that there is only a right to restitution and not a right to restoration, and that claimants can still be offered an alternative remedy in lieu of restoration, and in the process courts are ignorant of the fact that these other remedies do not help to change the skewed racial distribution of land in South Africa. Two factors seem to weigh heavily with the courts in favouring the granting of a section 34 order, it being the development of the land or development potential and the avoidance of the cost of a lengthy trial focusing on the restoration when there is no chance of success. It is submitted that there seems to be an over-emphasis on these factors while ignoring the fact that a person’s house is part of his identity, deserving more protection than other property, such as a shopping centre, which is not constitutive of a person’s identity. This view is espoused by Radin. Dyal-Chand postulates the idea that property is not always exclusive but can be shared. This would mean that when it comes to property like shopping centres, which she regards as quasi-public property, the courts should be more willing to grant restoration orders and thus not be so willing to grant section 34 non-restoration orders. Even though the RLRA, through section 34(5)(c) gives the courts the power to transform our colonial system of property law, it is submitted that they have largely failed to rise to this challenge. There appears to be an unwillingness to make a shift from our Roman-Dutch law past and break with our Eurocentric view of property law.
- Full Text:
- Date Issued: 2018
- Date: 2018
- Subjects: Restitution -- South Africa , Land reform -- South Africa , Land reform -- Government policy -- South Africa
- Type: Thesis , Masters , LLM
- Identifier: http://hdl.handle.net/10948/23869 , http://vital.seals.ac.za8080/10948/29168 , vital:30636
- Description: The land question is an emotionally-laden issue for all people across the racial divide in South Africa, albeit for different reasons land serves a variety of human needs: it creates a sense of identity, it creates wealth, imbues the owner with human dignity; it is also an axis for social cohesion and it is key to the exercise of economic and political power. South Africa is still in the throes of withdrawal symptoms as a result of a checkered colonial past, when it comes to the issue of the land. Having been dispossessed of their ancestral land by the country’s former colonial rulers, the majority of South Africans now have the yearning that the wrongs of the past be addressed, and that justice be done. Having repealed the Apartheid laws which had provided for the calculated systematic dispossession of the land and rights in land of the majority of citizens of South Africa, was and is not sufficient. The Constitution of the Republic of South Africa, being negotiated Constitution, which is internationally lauded, provides for a three-pronged land reform programme, namely restitution, redistribution and tenure reform. The focus of this dissertation is on the restitution leg and more specifically the issue of non-restoration which is provided for in section 34 of the RLRA 22 of 1994, as amended (the RLRA). Section 34 specifically provides that in some instances, land will not be restored to claimants even though they may satisfy the requirements for a valid claim provided for in section 25(7) of the Constitution and section 2 of the RLRA. It is submitted that it is necessary to acquire an understanding of the requirements for a restitution claim even though the land claimed may be removed from the process before a claim has been finalised, since the claimants will still have to satisfy the abovementioned requirements after a particular parcel of land or right in land has been removed from the process by a court of law. In other words, the court has made an order of non-restoration even before the claim has been finalised. Such an application for non-restoration of the land in question or rights in relation to land, may be brought by any national, provincial or local government body, in terms of section 34(1) of the RLRA, and the court will then grant such application provided the applicant has convinced the court that the two threshold requirements listed in section 34(6) have been satisfied. This dissertation outlines a number of cases which serve as practical examples of how the courts dealt with the threshold requirements contained in section 34(6). Included in this examination is the courts’ interpretation of the concepts “public interest” and “substantial prejudice”, which are contained in the requirements listed in section 34(6). This dissertation furthermore sought to determine whether the courts have adopted a broad or narrow approach to these concepts and whether the approach that the courts have adopted strikes an appropriate balance between the constitutional right to restitution and the goals underlying section 34. What is evident from the research is that, apart from the Constitutional Court in the KwaLindile case, none of the other courts provided a substantive definition of the concept “public interest”, but rather chose to refer to academic writings. It is submitted that the courts by and large appear to overlook the fact that the restitution of land and rights in land and arguably, the restoration of land, are in the public interest. While the courts do acknowledge the claimants’ rights to restitution, they downplay the importance of restoration since they argue that there is only a right to restitution and not a right to restoration, and that claimants can still be offered an alternative remedy in lieu of restoration, and in the process courts are ignorant of the fact that these other remedies do not help to change the skewed racial distribution of land in South Africa. Two factors seem to weigh heavily with the courts in favouring the granting of a section 34 order, it being the development of the land or development potential and the avoidance of the cost of a lengthy trial focusing on the restoration when there is no chance of success. It is submitted that there seems to be an over-emphasis on these factors while ignoring the fact that a person’s house is part of his identity, deserving more protection than other property, such as a shopping centre, which is not constitutive of a person’s identity. This view is espoused by Radin. Dyal-Chand postulates the idea that property is not always exclusive but can be shared. This would mean that when it comes to property like shopping centres, which she regards as quasi-public property, the courts should be more willing to grant restoration orders and thus not be so willing to grant section 34 non-restoration orders. Even though the RLRA, through section 34(5)(c) gives the courts the power to transform our colonial system of property law, it is submitted that they have largely failed to rise to this challenge. There appears to be an unwillingness to make a shift from our Roman-Dutch law past and break with our Eurocentric view of property law.
- Full Text:
- Date Issued: 2018
High-intensity Interval Training utilising a standardised versus customised training programme among endurance trained male cyclists
- Authors: Salzwedel, Jarred Wayne
- Date: 2020
- Subjects: Cycling South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/46423 , vital:39596
- Description: The primary aim of this study was to compare the effect of a standardised versus customised high-intensity interval training programmeon performance indicators of endurance trained male cyclists utilising a standardised method of prescribing intervals in comparison to a customised method of prescribing intervals based on training feedback. The study was exploratory and quasi-experimental in nature and utilized a quantitative approach. A quasi-experimental, pretest-postestcontrol group study design was used. A total number of 22 participants that met the inclusion criteria were included in the study by means of purposive sampling. The participants were subdivided into an experimental group (n=11) and a control group (n=11)by means of random stratification in order to ensure performance equality between the two groups. The experimental group completed a High-Intensity Interval Training (HIIT) block of 28 days (four weeks) with three weeks of interval-based sessions and one recovery week ending off the block. The programmeutilised the same “anaerobic” type intervals (10 x 30 seconds at 170% PPO with 4 minutes 30 seconds recovery) as the control group, performed twice per week for three consecutive weeks. The Lamberts and Lambert submaximal cycling test (LSCT) was used to determine whether a participant in the experimental group could start his HIIT session on a particular day.Participants were notallowed to start their HIIT session if twoor more of the set criteria weremet.If the participants did not qualify to participate in a HIIT session they were required to perform a low intensity training session in the same venue. Differences between the pre-and post-test showed statistically non-significant improvements (p>0.05) from pre-to post-test for both the experimental and control groups in respect of the physiological variables measured (gas exchange threshold, respiratory compensation point, maximal oxygen consumption). The experimental group did however show more positive, but statistically non-significantimprovements in peak power output. The findings of this study therefore showed that no significant within group nor between group improvements were achieved utilizing a standised versus customised HIIT training programme over the four-week study period. The findings do however suggest that the LSCT may have merit in prescribing HIIT sessions in trained athletesas suggested by the improvements of the experimental group’s peak power output.
- Full Text:
- Date Issued: 2020
- Authors: Salzwedel, Jarred Wayne
- Date: 2020
- Subjects: Cycling South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/46423 , vital:39596
- Description: The primary aim of this study was to compare the effect of a standardised versus customised high-intensity interval training programmeon performance indicators of endurance trained male cyclists utilising a standardised method of prescribing intervals in comparison to a customised method of prescribing intervals based on training feedback. The study was exploratory and quasi-experimental in nature and utilized a quantitative approach. A quasi-experimental, pretest-postestcontrol group study design was used. A total number of 22 participants that met the inclusion criteria were included in the study by means of purposive sampling. The participants were subdivided into an experimental group (n=11) and a control group (n=11)by means of random stratification in order to ensure performance equality between the two groups. The experimental group completed a High-Intensity Interval Training (HIIT) block of 28 days (four weeks) with three weeks of interval-based sessions and one recovery week ending off the block. The programmeutilised the same “anaerobic” type intervals (10 x 30 seconds at 170% PPO with 4 minutes 30 seconds recovery) as the control group, performed twice per week for three consecutive weeks. The Lamberts and Lambert submaximal cycling test (LSCT) was used to determine whether a participant in the experimental group could start his HIIT session on a particular day.Participants were notallowed to start their HIIT session if twoor more of the set criteria weremet.If the participants did not qualify to participate in a HIIT session they were required to perform a low intensity training session in the same venue. Differences between the pre-and post-test showed statistically non-significant improvements (p>0.05) from pre-to post-test for both the experimental and control groups in respect of the physiological variables measured (gas exchange threshold, respiratory compensation point, maximal oxygen consumption). The experimental group did however show more positive, but statistically non-significantimprovements in peak power output. The findings of this study therefore showed that no significant within group nor between group improvements were achieved utilizing a standised versus customised HIIT training programme over the four-week study period. The findings do however suggest that the LSCT may have merit in prescribing HIIT sessions in trained athletesas suggested by the improvements of the experimental group’s peak power output.
- Full Text:
- Date Issued: 2020
The design of a building linking central and the Baakens river mouth
- Authors: de Klerk, Paul
- Date: 2019
- Subjects: Architecture -- South Africa -- Port Elizabeth -- 21st century , Architecture -- South Africa -- Port Elizabeth , Urban renewal -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MArch
- Identifier: http://hdl.handle.net/10948/43138 , vital:36746
- Description: This treatsie focuses around the reationship of the Baakens Valley and the historical core and their respective declined states that has been affected through shifts in urban development and urban sprawl. Urban centres are moving away from the core decentralizing activity affecting the central areas allowing people-orientated environments to decline as an outcome of urbanism. Settlement expansion was forced along the coast due to topography Decentralised city growth with urban sprawl far from the historical core. New centres developed within residential realms detracted from people returning to the historical core Increased major arterial routes diminished density through vehicular orientated living spaces vs the density of the historical core orientated to the pedestian and mixed use activity City centre deteriorated due to Urban expansion and activity centres leaving the CBD resulting in a dilapidated city core.
- Full Text:
- Date Issued: 2019
- Authors: de Klerk, Paul
- Date: 2019
- Subjects: Architecture -- South Africa -- Port Elizabeth -- 21st century , Architecture -- South Africa -- Port Elizabeth , Urban renewal -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MArch
- Identifier: http://hdl.handle.net/10948/43138 , vital:36746
- Description: This treatsie focuses around the reationship of the Baakens Valley and the historical core and their respective declined states that has been affected through shifts in urban development and urban sprawl. Urban centres are moving away from the core decentralizing activity affecting the central areas allowing people-orientated environments to decline as an outcome of urbanism. Settlement expansion was forced along the coast due to topography Decentralised city growth with urban sprawl far from the historical core. New centres developed within residential realms detracted from people returning to the historical core Increased major arterial routes diminished density through vehicular orientated living spaces vs the density of the historical core orientated to the pedestian and mixed use activity City centre deteriorated due to Urban expansion and activity centres leaving the CBD resulting in a dilapidated city core.
- Full Text:
- Date Issued: 2019
The impact of job embeddedness on innovative work behaviours
- Authors: Wood, Jaryd Marc
- Date: 2019
- Subjects: Organizational behavior -- South Africa , Employee retention -- South Africa , Work -- Psychological aspects , Work ethic -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10948/44379 , vital:37160
- Description: Modern day organisations compete in an ever growing and highly competitive global environment. International competitiveness continues to play a critical role in ensuring that both organisations and employees grow and succeed. An organisation’s and employee’s ability to innovate remains one of the key factors in ensuring that they remain competitive and relevant amongst global organisations. Globalisation, access to advanced technology and the enhanced ability to travel has further enabled consumers and to keep up to date with international trends. These phenomena’s make it increasingly and ever important to remain relevant and innovate to attract new customers or consumers and to retain the current ones. The term job embeddedness relates to the relationships employees have between the organisation they work for and the community they form part of. It is felt that a link may exist between job embeddedness and employees engagement in innovative work behaviours to ensure that employees continuously generate new and improved processes, ideas, technologies to contribute to the organisations success. It is against this setting that an empirical study was created for the purpose of concluding evidential data needed to draw conclusions and make recommendations to leadership within organisation’s relating to the impact that job embeddedness has on engagement in innovative work behaviours. Furthermore, the impact of job embeddedness is tested against employee’s engagement in innovative work behaviours. 90 professional part-time executive MBA programme individuals who were enrolled at the Nelson Mandela University Business School in South Africa and who are based at the four major centres of the Business School, which included Port Elizabeth, Cape Town, Durban and Johannesburg were approached to take part in this study. These individuals were employed in a variety of spheres in industry, including engineering, financial services, information technology, accounting and management in organisations that spanned a multitude of additional industries. As a result of these individuals participation, 549 participants took part in the survey. Key findings of the study includes that employee fit into the organisation, employee fit into the community and employee perceived sacrifice in the event of leaving the organisation are all significantly related to engagement in innovative work behaviours. A key recommendation of the study would be that in order to increase the organisational aspect of job embeddedness, organisational leaders would need to consider ways to or place emphasis on factors that would promote organisational fit and organisational sacrifice.
- Full Text:
- Date Issued: 2019
- Authors: Wood, Jaryd Marc
- Date: 2019
- Subjects: Organizational behavior -- South Africa , Employee retention -- South Africa , Work -- Psychological aspects , Work ethic -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10948/44379 , vital:37160
- Description: Modern day organisations compete in an ever growing and highly competitive global environment. International competitiveness continues to play a critical role in ensuring that both organisations and employees grow and succeed. An organisation’s and employee’s ability to innovate remains one of the key factors in ensuring that they remain competitive and relevant amongst global organisations. Globalisation, access to advanced technology and the enhanced ability to travel has further enabled consumers and to keep up to date with international trends. These phenomena’s make it increasingly and ever important to remain relevant and innovate to attract new customers or consumers and to retain the current ones. The term job embeddedness relates to the relationships employees have between the organisation they work for and the community they form part of. It is felt that a link may exist between job embeddedness and employees engagement in innovative work behaviours to ensure that employees continuously generate new and improved processes, ideas, technologies to contribute to the organisations success. It is against this setting that an empirical study was created for the purpose of concluding evidential data needed to draw conclusions and make recommendations to leadership within organisation’s relating to the impact that job embeddedness has on engagement in innovative work behaviours. Furthermore, the impact of job embeddedness is tested against employee’s engagement in innovative work behaviours. 90 professional part-time executive MBA programme individuals who were enrolled at the Nelson Mandela University Business School in South Africa and who are based at the four major centres of the Business School, which included Port Elizabeth, Cape Town, Durban and Johannesburg were approached to take part in this study. These individuals were employed in a variety of spheres in industry, including engineering, financial services, information technology, accounting and management in organisations that spanned a multitude of additional industries. As a result of these individuals participation, 549 participants took part in the survey. Key findings of the study includes that employee fit into the organisation, employee fit into the community and employee perceived sacrifice in the event of leaving the organisation are all significantly related to engagement in innovative work behaviours. A key recommendation of the study would be that in order to increase the organisational aspect of job embeddedness, organisational leaders would need to consider ways to or place emphasis on factors that would promote organisational fit and organisational sacrifice.
- Full Text:
- Date Issued: 2019
Project management in the Mauritian construction industry
- Paurobally, Mohamad Ali Zeeshan
- Authors: Paurobally, Mohamad Ali Zeeshan
- Date: 2018
- Subjects: Project management -- Mauritius , Construction industry -- Mauritius , Construction industry -- Forecasting
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/34499 , vital:33386
- Description: The main objective of this research study was to find out the various factors affecting the success of projects, with specific reference to the client’s related factors, consultant’s related and main contractor’s related factors. Completion of the construction project within the required cost, time and quality parameters was identified as the motivation for the study. The objectives of the study were achieved by reviewing literature relevant to the topic. The study investigated whether certain assumptions being made were corresponding with already published literature. Data were sourced both from primary and secondary sources. The quantitative part of the research was carried out by analyzing the literature and by envisaging possible scenarios which could be implemented for the completion of projects, within the three parameters (Time, cost and quality). Not being able to complete a project within the required cost, time and quality parameters will ultimately result in time and cost overruns up to the dissatisfaction of the client. As such, the various stages of the construction cycle need to be monitored and controlled as from the inception stage up to the close out stage by the various stakeholders involved on the project in order to obtain a positive project outcome. The research sample was focused mainly on professionals in the built environment, since a better understanding and reliable feedback would be obtained due to their understanding of the relevant topic. The study first introduces project management as a background, and then focuses on the different factors that influence successful project outcome.
- Full Text:
- Date Issued: 2018
- Authors: Paurobally, Mohamad Ali Zeeshan
- Date: 2018
- Subjects: Project management -- Mauritius , Construction industry -- Mauritius , Construction industry -- Forecasting
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/34499 , vital:33386
- Description: The main objective of this research study was to find out the various factors affecting the success of projects, with specific reference to the client’s related factors, consultant’s related and main contractor’s related factors. Completion of the construction project within the required cost, time and quality parameters was identified as the motivation for the study. The objectives of the study were achieved by reviewing literature relevant to the topic. The study investigated whether certain assumptions being made were corresponding with already published literature. Data were sourced both from primary and secondary sources. The quantitative part of the research was carried out by analyzing the literature and by envisaging possible scenarios which could be implemented for the completion of projects, within the three parameters (Time, cost and quality). Not being able to complete a project within the required cost, time and quality parameters will ultimately result in time and cost overruns up to the dissatisfaction of the client. As such, the various stages of the construction cycle need to be monitored and controlled as from the inception stage up to the close out stage by the various stakeholders involved on the project in order to obtain a positive project outcome. The research sample was focused mainly on professionals in the built environment, since a better understanding and reliable feedback would be obtained due to their understanding of the relevant topic. The study first introduces project management as a background, and then focuses on the different factors that influence successful project outcome.
- Full Text:
- Date Issued: 2018
South Africa’s readiness of the smart built environment towards 2035
- Authors: Holmes, Clinton Keith
- Date: 2019
- Subjects: Internet of things , City planning , Technology -- Social aspects
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10948/40128 , vital:35758
- Description: It is imperative that society works together with government and industry to find solutions in solving the problem of the high utilisation of natural resources in the built environment. Natural resources are not infinite, and the increasing population are compounding the problem. The high level of unemployment in South Africa could be increased dramatically if the old skills in the industry become redundant due to new technology and there are not enough skills to apply to these technologies. This study set out to investigate the extent of the readiness of South Africa for the Smart built environment towards 2035 with an aim to provide valuable information for decision making to the government, policy makers, academic and training institutions and business leaders. South Africa boasts about the achievements of the four major municipalities namely, Cape Town, Johannesburg, Tshwane and eThekwini in terms of their commitment towards the aim for net zero carbon emissions of newly built buildings by 2050. The commitment for sustainable solutions in all sectors is echoed by the Minister of Environmental affairs, as part of the Paris agreement. South Africa does not lack the ability to plan for eventualities. This is evident by the myriad of strategies and policies that can be found all over the government information sharing outlets. The South African government is failing in implementing these policies and strategies that have been around for more than a decade. A lack of execution, lack of transparency as well as a lack of accountability is a hindrance to South Africa’s general growth path. The realisation of the preferred future rest on the acceptance, by all South Africans, that technological advancement is inevitable, and that a joint and inclusive effort should be made to prepare for such a future. South Africa has the ability and appetite to change the future for the better. Two fundamental areas of improvement are to create a united South Africa where people are held accountable for their actions. The unisons should transcend across the various South African government departments but must also include industry, entrepreneurs and the public to create a future where technology is embraced, and innovation encouraged, instead of waiting for technology to dictate a specific future.
- Full Text:
- Date Issued: 2019
- Authors: Holmes, Clinton Keith
- Date: 2019
- Subjects: Internet of things , City planning , Technology -- Social aspects
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10948/40128 , vital:35758
- Description: It is imperative that society works together with government and industry to find solutions in solving the problem of the high utilisation of natural resources in the built environment. Natural resources are not infinite, and the increasing population are compounding the problem. The high level of unemployment in South Africa could be increased dramatically if the old skills in the industry become redundant due to new technology and there are not enough skills to apply to these technologies. This study set out to investigate the extent of the readiness of South Africa for the Smart built environment towards 2035 with an aim to provide valuable information for decision making to the government, policy makers, academic and training institutions and business leaders. South Africa boasts about the achievements of the four major municipalities namely, Cape Town, Johannesburg, Tshwane and eThekwini in terms of their commitment towards the aim for net zero carbon emissions of newly built buildings by 2050. The commitment for sustainable solutions in all sectors is echoed by the Minister of Environmental affairs, as part of the Paris agreement. South Africa does not lack the ability to plan for eventualities. This is evident by the myriad of strategies and policies that can be found all over the government information sharing outlets. The South African government is failing in implementing these policies and strategies that have been around for more than a decade. A lack of execution, lack of transparency as well as a lack of accountability is a hindrance to South Africa’s general growth path. The realisation of the preferred future rest on the acceptance, by all South Africans, that technological advancement is inevitable, and that a joint and inclusive effort should be made to prepare for such a future. South Africa has the ability and appetite to change the future for the better. Two fundamental areas of improvement are to create a united South Africa where people are held accountable for their actions. The unisons should transcend across the various South African government departments but must also include industry, entrepreneurs and the public to create a future where technology is embraced, and innovation encouraged, instead of waiting for technology to dictate a specific future.
- Full Text:
- Date Issued: 2019
A national strategy towards cultivating a cybersecurity culture in South Africa
- Authors: Gcaza, Noluxolo
- Date: 2017
- Subjects: Computer networks -- Security measures , Cyberspace -- Security measures , Computer security -- South Africa , Subculture -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/13735 , vital:27303
- Description: In modern society, cyberspace is interwoven into the daily lives of many. Cyberspace is increasingly redefining how people communicate as well as gain access to and share information. Technology has transformed the way the business world operates by introducing new ways of trading goods and services whilst bolstering traditional business methods. It has also altered the way nations govern. Thus individuals, organisations and nations are relying on this technology to perform significant functions. Alongside the positive innovations afforded by cyberspace, however, those who use it are exposed to a variety of risks. Cyberspace is beset by criminal activities such as cybercrime, fraud, identity theft to name but a few. Nonetheless, the negative impact of these cyber threats does not outweigh the advantages of cyberspace. In light of such threats, there is a call for all entities that reap the benefits of online services to institute cybersecurity. As such, cybersecurity is a necessity for individuals, organisations and nations alike. In practice, cybersecurity focuses on preventing and mitigating certain security risks that might compromise the security of relevant assets. For a long time, technology-centred measures have been deemed the most significant solution for mitigating such risks. However, after a legacy of unsuccessful technological efforts, it became clear that such solutions in isolation are insufficient to mitigate all cyber-related risks. This is mainly due to the role that humans play in the security process, that is, the human factor. In isolation, technology-centred measures tend to fail to counter the human factor because of the perception among many users that security measures are an obstacle and consequently a waste of time. This user perception can be credited to the perceived difficulty of the security measure, as well as apparent mistrust and misinterpretation of the measure. Hence, cybersecurity necessitates the development of a solution that encourages acceptable user behaviour in the reality of cyberspace. The cultivation of a cybersecurity culture is thus regarded as the best approach for addressing the human factors that weaken the cybersecurity chain. While the role of culture in pursuing cybersecurity is well appreciated, research focusing on defining and measuring cybersecurity culture is still in its infancy. Furthermore, studies have shown that there are no widely accepted key concepts that delimit a cybersecurity culture. However, the notion that such a culture is not well-delineated has not prevented national governments from pursuing a culture in which all citizens behave in a way that promotes cybersecurity. As a result, many countries now offer national cybersecurity campaigns to foster a culture of cybersecurity at a national level. South Africa is among the nations that have identified cultivating a culture of cybersecurity as a strategic priority. However, there is an apparent lack of a practical plan to cultivate such a cybersecurity culture in South Africa. Thus, this study sought firstly to confirm from the existing body of knowledge that cybersecurity culture is indeed ill-defined and, secondly, to delineate what constitutes a national cybersecurity culture. Finally, and primarily, it sought to devise a national strategy that would assist SA in fulfilling its objective of cultivating a culture of cybersecurity on a national level.
- Full Text:
- Date Issued: 2017
- Authors: Gcaza, Noluxolo
- Date: 2017
- Subjects: Computer networks -- Security measures , Cyberspace -- Security measures , Computer security -- South Africa , Subculture -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/13735 , vital:27303
- Description: In modern society, cyberspace is interwoven into the daily lives of many. Cyberspace is increasingly redefining how people communicate as well as gain access to and share information. Technology has transformed the way the business world operates by introducing new ways of trading goods and services whilst bolstering traditional business methods. It has also altered the way nations govern. Thus individuals, organisations and nations are relying on this technology to perform significant functions. Alongside the positive innovations afforded by cyberspace, however, those who use it are exposed to a variety of risks. Cyberspace is beset by criminal activities such as cybercrime, fraud, identity theft to name but a few. Nonetheless, the negative impact of these cyber threats does not outweigh the advantages of cyberspace. In light of such threats, there is a call for all entities that reap the benefits of online services to institute cybersecurity. As such, cybersecurity is a necessity for individuals, organisations and nations alike. In practice, cybersecurity focuses on preventing and mitigating certain security risks that might compromise the security of relevant assets. For a long time, technology-centred measures have been deemed the most significant solution for mitigating such risks. However, after a legacy of unsuccessful technological efforts, it became clear that such solutions in isolation are insufficient to mitigate all cyber-related risks. This is mainly due to the role that humans play in the security process, that is, the human factor. In isolation, technology-centred measures tend to fail to counter the human factor because of the perception among many users that security measures are an obstacle and consequently a waste of time. This user perception can be credited to the perceived difficulty of the security measure, as well as apparent mistrust and misinterpretation of the measure. Hence, cybersecurity necessitates the development of a solution that encourages acceptable user behaviour in the reality of cyberspace. The cultivation of a cybersecurity culture is thus regarded as the best approach for addressing the human factors that weaken the cybersecurity chain. While the role of culture in pursuing cybersecurity is well appreciated, research focusing on defining and measuring cybersecurity culture is still in its infancy. Furthermore, studies have shown that there are no widely accepted key concepts that delimit a cybersecurity culture. However, the notion that such a culture is not well-delineated has not prevented national governments from pursuing a culture in which all citizens behave in a way that promotes cybersecurity. As a result, many countries now offer national cybersecurity campaigns to foster a culture of cybersecurity at a national level. South Africa is among the nations that have identified cultivating a culture of cybersecurity as a strategic priority. However, there is an apparent lack of a practical plan to cultivate such a cybersecurity culture in South Africa. Thus, this study sought firstly to confirm from the existing body of knowledge that cybersecurity culture is indeed ill-defined and, secondly, to delineate what constitutes a national cybersecurity culture. Finally, and primarily, it sought to devise a national strategy that would assist SA in fulfilling its objective of cultivating a culture of cybersecurity on a national level.
- Full Text:
- Date Issued: 2017
Triggering biodegradation of low-density polyethylene films containing biobased additives for ecological applications
- Authors: Gada, Abongile
- Date: 2019
- Subjects: Refuse and refuse disposal , Plastics industry and trade -- Waste disposal , Polyethylene , Polyurethanes
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/39796 , vital:35460
- Description: The aims of the present study are focused on the investigation of low-density polyethylene (LDPE) films that contain biobased pro-oxidizing additives (CSIR1% and CSIR3% (w/w)) for environmental degradation in different abiotic and biotic conditions in comparison to non-biodegradable commercially available Pick n Pay (PnP) PE grocery bags. In this project, a biobased pro-oxidant additive master batch was prepared in a heat kneader mixer. A mixture of biobased radical reaction initiators and natural polymers were melt processed as a master batch. The biobased pro-oxidant additive master batch CSIR1% and CSIR3% and LDPE components were melt-extruded to form biobased pro-oxidant additive LDPE pellets using a twin screw melt extruder. The pelletized biobased pro-oxidant additive LDPE was blown into a 25 -27 μm thick film using a melt blower machine. The LDPE containing biobased pro-oxidant additive CSIR 1% and 3% test samples and the PnP polyethylene carrier bags were submitted to thermal oxidizing test conditions in a 70°C air ventilated oven and direct sunlight (photo oxidation) for a period of six months (180 days). The thermal and photo-oxidized LDPE film test samples were further subjected to biotic degradation tests in aqueous, soil and compost environments for varying periods of 180 days to 263 days in biodegradation evaluation studies. The oxidation degradation rates of the test samples were monitored and determined by evaluating carbonyl index (COi) using FT-IR spectroscopy; molecular weight determination and distribution of the test materials were analyzed by Gel Permeation Chromatography (GPC); compounds analysis was done by GC-MS; percentage crystallinity (Xc%) was quantified by DSC; thermal stability by TGA and morphological surfaces were examined by SEM analytical techniques. Biodegradation tests simulating marine salt water, burial in soil and compost conditioning methods were used to determine the “potential biodegradability” of the thermally and photo-oxidized test samples after the oxidation period. The oxidation extent and rate of LDPE films containing CSIR3% biobased additives was higher than that of LDPE films containing CSIR1% biobased additives. GPC molecular weight determination and distribution results showed a decrease for all the test samples exposed to oxidation. The molecular weight of LDPE films containing CSIR1% biobased additives decreased from 404K Mw to 111K Mw for sunlight oxidized samples and to 16KMw for the thermally oxidized LDPE samples after 200 days of oxidation exposure. Molecular weight of LDPE films containing CSIR3% biobased additives showed the most reduction from 293K Mw to 22K Mw for sunlight oxidized samples and to 2K Mw for thermally oxidized samples after 100 days of oxidation exposure. DSC analysis showed that crystallinity degree decreased after exposure to thermal and photo-oxidation. TGA results showed a reduction of initial degradation temperature by almost half compared to zero-days untreated CSIR3% samples, with higher degree temperatures observed in samples exposed to thermal oxidation than those exposed to photo-oxidation. GC-MS revealed peaks of carbonyls such as alcohols, aldehydes, ketones, carboxylic and anionic acids, and very short chain alkenes and alkanes. The SEM showed heterogeneous morphological modifications in surfaces of samples even though they were not severe. After 172 days the oxidized LDPE samples containing CSIR3% biobased additives, were investigated for potential biodegradation in aqueous, soil and composting environments. Thermally oxidized and photo-oxidized CSIR3% samples showed a mineralization degree of 10.4% and 10.7% respectively, when oxidized in 181 days aqueous biodegradation, 20% and 7.7% respectively, when oxidized in 233 days of soil burial, and 52.6% and 62% respectively, oxidized in 263 days of compost. The obtained results confirmed the abiotic oxidation step as the initiation step for PE degradation, succeeded by assimilation, by action of microorganisms (ultimate biodegradation), of lower weight molecular compounds of oxidized LDPE samples in aqueous medium, soil and composting conditions to final end products of CO2, H2O and new microbial cell biomass.
- Full Text:
- Date Issued: 2019
- Authors: Gada, Abongile
- Date: 2019
- Subjects: Refuse and refuse disposal , Plastics industry and trade -- Waste disposal , Polyethylene , Polyurethanes
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/39796 , vital:35460
- Description: The aims of the present study are focused on the investigation of low-density polyethylene (LDPE) films that contain biobased pro-oxidizing additives (CSIR1% and CSIR3% (w/w)) for environmental degradation in different abiotic and biotic conditions in comparison to non-biodegradable commercially available Pick n Pay (PnP) PE grocery bags. In this project, a biobased pro-oxidant additive master batch was prepared in a heat kneader mixer. A mixture of biobased radical reaction initiators and natural polymers were melt processed as a master batch. The biobased pro-oxidant additive master batch CSIR1% and CSIR3% and LDPE components were melt-extruded to form biobased pro-oxidant additive LDPE pellets using a twin screw melt extruder. The pelletized biobased pro-oxidant additive LDPE was blown into a 25 -27 μm thick film using a melt blower machine. The LDPE containing biobased pro-oxidant additive CSIR 1% and 3% test samples and the PnP polyethylene carrier bags were submitted to thermal oxidizing test conditions in a 70°C air ventilated oven and direct sunlight (photo oxidation) for a period of six months (180 days). The thermal and photo-oxidized LDPE film test samples were further subjected to biotic degradation tests in aqueous, soil and compost environments for varying periods of 180 days to 263 days in biodegradation evaluation studies. The oxidation degradation rates of the test samples were monitored and determined by evaluating carbonyl index (COi) using FT-IR spectroscopy; molecular weight determination and distribution of the test materials were analyzed by Gel Permeation Chromatography (GPC); compounds analysis was done by GC-MS; percentage crystallinity (Xc%) was quantified by DSC; thermal stability by TGA and morphological surfaces were examined by SEM analytical techniques. Biodegradation tests simulating marine salt water, burial in soil and compost conditioning methods were used to determine the “potential biodegradability” of the thermally and photo-oxidized test samples after the oxidation period. The oxidation extent and rate of LDPE films containing CSIR3% biobased additives was higher than that of LDPE films containing CSIR1% biobased additives. GPC molecular weight determination and distribution results showed a decrease for all the test samples exposed to oxidation. The molecular weight of LDPE films containing CSIR1% biobased additives decreased from 404K Mw to 111K Mw for sunlight oxidized samples and to 16KMw for the thermally oxidized LDPE samples after 200 days of oxidation exposure. Molecular weight of LDPE films containing CSIR3% biobased additives showed the most reduction from 293K Mw to 22K Mw for sunlight oxidized samples and to 2K Mw for thermally oxidized samples after 100 days of oxidation exposure. DSC analysis showed that crystallinity degree decreased after exposure to thermal and photo-oxidation. TGA results showed a reduction of initial degradation temperature by almost half compared to zero-days untreated CSIR3% samples, with higher degree temperatures observed in samples exposed to thermal oxidation than those exposed to photo-oxidation. GC-MS revealed peaks of carbonyls such as alcohols, aldehydes, ketones, carboxylic and anionic acids, and very short chain alkenes and alkanes. The SEM showed heterogeneous morphological modifications in surfaces of samples even though they were not severe. After 172 days the oxidized LDPE samples containing CSIR3% biobased additives, were investigated for potential biodegradation in aqueous, soil and composting environments. Thermally oxidized and photo-oxidized CSIR3% samples showed a mineralization degree of 10.4% and 10.7% respectively, when oxidized in 181 days aqueous biodegradation, 20% and 7.7% respectively, when oxidized in 233 days of soil burial, and 52.6% and 62% respectively, oxidized in 263 days of compost. The obtained results confirmed the abiotic oxidation step as the initiation step for PE degradation, succeeded by assimilation, by action of microorganisms (ultimate biodegradation), of lower weight molecular compounds of oxidized LDPE samples in aqueous medium, soil and composting conditions to final end products of CO2, H2O and new microbial cell biomass.
- Full Text:
- Date Issued: 2019
Isixhosa speaking biological fathers’ perceptions and experiences of parental alienation
- Mokolobate, Motshabi Catherine
- Authors: Mokolobate, Motshabi Catherine
- Date: 2019
- Subjects: Parental alienation syndrome , Fatherhood -- Psychological aspects , Father and Child -- Psychological aspects , Parenting -- Psychological aspects
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/45053 , vital:38229
- Description: There has been a positive shift in South African laws advocating for children and father’s rights to parent-child relationships. Children often get caught in the middle of their parents’ enduring battles and acrimonious separations or divorces frequently resulting in loss of contact with one parent. The term parental alienation is used to describe this phenomenon. Parental alienation can take many forms with the common thread being the negative impact that it has on the parent-child relationship and an increase in father absenteeism. The psychological effects of absent fathers on children and single parenthood are significant and contribute to social ailments such as substance abuse, violence and abuse. Extensive research has been conducted on the effects of parental alienation on children; however, there is limited research on how fathers experience parental alienation and how it shapes their perception of fatherhood. This study aimed to explore and describe the perceptions and experiences of fathers who have experienced parental alienation. A purposive sampling method was utilized using 6 participants who were sourced from a male-focused NGO in Zwide Township in the Port Elizabeth Metropolitan area. Data was collected through in-depth semi-structured audio taped interviews. Transcribed data was analysed by means of thematic analysis following Guba’s Model of Trustworthiness as a guide for data verification. All necessary ethical considerations were adhered to. Four themes emerged from the study. Participants understood and experienced parental alienation as unjust and painful; parental alienation was perceived as complex and challenging; upbringing influenced their paternal involvement and finally parental alienation affected their perception of fatherhood and their construction of paternal identity.
- Full Text:
- Date Issued: 2019
- Authors: Mokolobate, Motshabi Catherine
- Date: 2019
- Subjects: Parental alienation syndrome , Fatherhood -- Psychological aspects , Father and Child -- Psychological aspects , Parenting -- Psychological aspects
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/45053 , vital:38229
- Description: There has been a positive shift in South African laws advocating for children and father’s rights to parent-child relationships. Children often get caught in the middle of their parents’ enduring battles and acrimonious separations or divorces frequently resulting in loss of contact with one parent. The term parental alienation is used to describe this phenomenon. Parental alienation can take many forms with the common thread being the negative impact that it has on the parent-child relationship and an increase in father absenteeism. The psychological effects of absent fathers on children and single parenthood are significant and contribute to social ailments such as substance abuse, violence and abuse. Extensive research has been conducted on the effects of parental alienation on children; however, there is limited research on how fathers experience parental alienation and how it shapes their perception of fatherhood. This study aimed to explore and describe the perceptions and experiences of fathers who have experienced parental alienation. A purposive sampling method was utilized using 6 participants who were sourced from a male-focused NGO in Zwide Township in the Port Elizabeth Metropolitan area. Data was collected through in-depth semi-structured audio taped interviews. Transcribed data was analysed by means of thematic analysis following Guba’s Model of Trustworthiness as a guide for data verification. All necessary ethical considerations were adhered to. Four themes emerged from the study. Participants understood and experienced parental alienation as unjust and painful; parental alienation was perceived as complex and challenging; upbringing influenced their paternal involvement and finally parental alienation affected their perception of fatherhood and their construction of paternal identity.
- Full Text:
- Date Issued: 2019