Molecularly imprinted polymeric materials for adsorptive removal of nitrogen compounds from fuel oils
- Abdul-Quadir, Muhammad Sabiu
- Authors: Abdul-Quadir, Muhammad Sabiu
- Date: 2018
- Subjects: Polymerization , Organonitrogen compounds Nitrogen compounds
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/23426 , vital:30542
- Description: The deleterious effects of refractory polyaromatic hydrocarbons found in fuels such as organonitrogen compounds (quinoline, carbazole and its alkylated derivatives) are such that they emit NOx to the environment when combusted, thereby reducing air quality. These compounds also deactivate the catalyst used during fuel refinement and in catalytic converters of cars. Hydro-denitrogenation (HDN), a process currently being employed in petroleum refineries to eliminate organonitrogen compounds in fuels, is limited in treating these refractory compounds. Hence, this thesis describes the use of two separate complimentary approaches for the removal of organonitrogen compounds in fuel such as oxidative denitrogenation and adsorptive denitrogenation. The catalyzed oxidation of fuel oil model nitrogen containing compound, quinoline to quinoline N-oxide, was conducted under batch and continuous flow microreactor at 70°C by using tert-butylhydroperoxide (t-BuOOH) as oxidant and silica supported V2O5 as catalyst, followed by the selective adsorption of the quinoline N-oxide. An overall conversion of 62% quinoline N-oxide was observed. Quinoline-N-oxide in model fuel was absorbed by employing synthesized molecularly imprinted 2,6-pyridine-polybenzimidazole (2,6-PyPBI) nanofibers, 86% of quinoline-N-oxide was removed to give an adsorption capacity (qe) of 4.8 mg/g. DFT calculations to study the interactions of quinoline-N-oxide vs 2,6-PyPBI indicated that: (i) hydrogen bonding (through amino group of 2,6-PyPBI and oxygen atoms of the quinoline-N-oxide), (ii) pi-pi stacking and (iii) extensive number of van der Waals interactions took place. Several oxygenates from N-compounds were produced, thus, complicating the fuel matrix. Therefore, there is a need to move towards adsorptive denitrogenation. Poly-2-(1H-imidazol-2-yl)-4-phenol (PIMH) imprinted microspheres was prepared by suspension polymerization using 2-(2’-hydroxy-4-ethenylphenyl) imidazole as a functional monomer and ethylene glycol dimethacrylate as a crosslinker in the presence of various organonitrogen compounds (templates) to produce 2-(2’-hydroxy-4-ethenylphenyl) imidazole (PIMH). Imprinted microspheres show selectivity for various target model nitrogen-containing compounds with adsorption capacities of 6.8 ± 0.2 mg/g, 6.3 ± 0.3 mg/g and 5.8 ± 0.3 mg/g for quinoline, pyrimidine and carbazole, respectively. Adsorption selectivity increased in the order of quinoline (αi-r = 136.9) ˃ pyrimidine (αi-r = 126.2) ˃carbazole (αi-r = 86.3), when naphthalene was selected as a reference compound. Though, imprinted microspheres displayed excellent nitrogen compound removal both in model and real fuel, there was a need to improve the adsorbent adsorption capacity for N-compounds in fuel through the fabrication of imprinted nanofibers. Molecularly imprinted poly-2-(1H-imidazol-2-yl)-4-phenol nanofibers was prepared by electrospinning of 2-(2’-hydroxy-4-ethenylphenyl) imidazole (PIMH) in the presence of various organonitrogen compounds. These imprinted nanofibers show selectivity for various target model nitrogen-containing compounds with adsorption capacities of 11.7 ± 0.9 mg/g, 11.9 ± 0.8 mg/g and 11.3 ± 1.1 mg/g for quinoline, pyrimidine and carbazole, respectively. Adsorption selectivity increased in the order of pyrimidine (αi-r = 258.8) ˃ quinoline (αi-r = 235.5) ˃ carbazole (αi-r = 168.2). It further displayed excellent nitrogen removal in real fuel. The use of polybenzimidazole (PBI) nanofibers showed selective adsorption of organonitrogen compounds as imprinted sorbent also displayed high selectivity for their target model nitrogen-containing compounds with adsorption capacities of 11.4 ± 0.4 mg/g, 11.9 ± 0.2 mg/g and 10.9 ± 0.7 mg/g for quinoline, pyrimidine and carbazole respectively. Adsorption selectivity increased in the order of pyrimidine (αi-r = 241.5) ˃ quinoline (αi-r = 237.6) ˃ carbazole (αi-r = 170). Thermodynamic parameters obtained from isothermal titration calorimetry (ITC) revealed that quinoline-PIMH/PBI and pyrimidine-PIMH/PBI interactions are exothermic in nature, while carbazole-PIMH/PBI is endothermic in nature. DFT calculations indicated that π-π interactions/stacking and hydrogen bond interactions took place between N-compounds (carbazole, quinoline and pyrimidine) and adsorbent (PIMH and PBI). A significant reduction in the quantity of nitrogen containing compounds in hydrotreated fuel was observed (peak area reduction) when adsorbents (PIMH and PBI) was employed, however, the complex nature of organonitrogen compounds in fuel complicate the structure/function approach on MIPs for targeting these unwanted compounds.
- Full Text:
- Date Issued: 2018
- Authors: Abdul-Quadir, Muhammad Sabiu
- Date: 2018
- Subjects: Polymerization , Organonitrogen compounds Nitrogen compounds
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/23426 , vital:30542
- Description: The deleterious effects of refractory polyaromatic hydrocarbons found in fuels such as organonitrogen compounds (quinoline, carbazole and its alkylated derivatives) are such that they emit NOx to the environment when combusted, thereby reducing air quality. These compounds also deactivate the catalyst used during fuel refinement and in catalytic converters of cars. Hydro-denitrogenation (HDN), a process currently being employed in petroleum refineries to eliminate organonitrogen compounds in fuels, is limited in treating these refractory compounds. Hence, this thesis describes the use of two separate complimentary approaches for the removal of organonitrogen compounds in fuel such as oxidative denitrogenation and adsorptive denitrogenation. The catalyzed oxidation of fuel oil model nitrogen containing compound, quinoline to quinoline N-oxide, was conducted under batch and continuous flow microreactor at 70°C by using tert-butylhydroperoxide (t-BuOOH) as oxidant and silica supported V2O5 as catalyst, followed by the selective adsorption of the quinoline N-oxide. An overall conversion of 62% quinoline N-oxide was observed. Quinoline-N-oxide in model fuel was absorbed by employing synthesized molecularly imprinted 2,6-pyridine-polybenzimidazole (2,6-PyPBI) nanofibers, 86% of quinoline-N-oxide was removed to give an adsorption capacity (qe) of 4.8 mg/g. DFT calculations to study the interactions of quinoline-N-oxide vs 2,6-PyPBI indicated that: (i) hydrogen bonding (through amino group of 2,6-PyPBI and oxygen atoms of the quinoline-N-oxide), (ii) pi-pi stacking and (iii) extensive number of van der Waals interactions took place. Several oxygenates from N-compounds were produced, thus, complicating the fuel matrix. Therefore, there is a need to move towards adsorptive denitrogenation. Poly-2-(1H-imidazol-2-yl)-4-phenol (PIMH) imprinted microspheres was prepared by suspension polymerization using 2-(2’-hydroxy-4-ethenylphenyl) imidazole as a functional monomer and ethylene glycol dimethacrylate as a crosslinker in the presence of various organonitrogen compounds (templates) to produce 2-(2’-hydroxy-4-ethenylphenyl) imidazole (PIMH). Imprinted microspheres show selectivity for various target model nitrogen-containing compounds with adsorption capacities of 6.8 ± 0.2 mg/g, 6.3 ± 0.3 mg/g and 5.8 ± 0.3 mg/g for quinoline, pyrimidine and carbazole, respectively. Adsorption selectivity increased in the order of quinoline (αi-r = 136.9) ˃ pyrimidine (αi-r = 126.2) ˃carbazole (αi-r = 86.3), when naphthalene was selected as a reference compound. Though, imprinted microspheres displayed excellent nitrogen compound removal both in model and real fuel, there was a need to improve the adsorbent adsorption capacity for N-compounds in fuel through the fabrication of imprinted nanofibers. Molecularly imprinted poly-2-(1H-imidazol-2-yl)-4-phenol nanofibers was prepared by electrospinning of 2-(2’-hydroxy-4-ethenylphenyl) imidazole (PIMH) in the presence of various organonitrogen compounds. These imprinted nanofibers show selectivity for various target model nitrogen-containing compounds with adsorption capacities of 11.7 ± 0.9 mg/g, 11.9 ± 0.8 mg/g and 11.3 ± 1.1 mg/g for quinoline, pyrimidine and carbazole, respectively. Adsorption selectivity increased in the order of pyrimidine (αi-r = 258.8) ˃ quinoline (αi-r = 235.5) ˃ carbazole (αi-r = 168.2). It further displayed excellent nitrogen removal in real fuel. The use of polybenzimidazole (PBI) nanofibers showed selective adsorption of organonitrogen compounds as imprinted sorbent also displayed high selectivity for their target model nitrogen-containing compounds with adsorption capacities of 11.4 ± 0.4 mg/g, 11.9 ± 0.2 mg/g and 10.9 ± 0.7 mg/g for quinoline, pyrimidine and carbazole respectively. Adsorption selectivity increased in the order of pyrimidine (αi-r = 241.5) ˃ quinoline (αi-r = 237.6) ˃ carbazole (αi-r = 170). Thermodynamic parameters obtained from isothermal titration calorimetry (ITC) revealed that quinoline-PIMH/PBI and pyrimidine-PIMH/PBI interactions are exothermic in nature, while carbazole-PIMH/PBI is endothermic in nature. DFT calculations indicated that π-π interactions/stacking and hydrogen bond interactions took place between N-compounds (carbazole, quinoline and pyrimidine) and adsorbent (PIMH and PBI). A significant reduction in the quantity of nitrogen containing compounds in hydrotreated fuel was observed (peak area reduction) when adsorbents (PIMH and PBI) was employed, however, the complex nature of organonitrogen compounds in fuel complicate the structure/function approach on MIPs for targeting these unwanted compounds.
- Full Text:
- Date Issued: 2018
A co-constructed practice model for supporting parents of children in conflict with the law
- Authors: Abdulla, Zurina
- Date: 2019
- Subjects: Children's rights -- South Africa , Children -- Legal status, laws, etc --South Africa , Parent and child -- Research -- South Africa , Social work with youth -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/30474 , vital:30949
- Description: The unique historical stressors linked to South Africa’s apartheid legacy, continues to manifest in the form of economic exclusion, social exclusion, inequality and poverty, with parents being subjugated to service users and extenders rather than included as service advocates, particularly in the child justice system. Furthermore, policies and practices do not include, engage and support parents on an intra and interpersonal level. Parents of children in conflict with the law, experience their children’s charge or arrest as well as their subsequent journey through the child justice system as a crisis resulting in their need for emotional, informational, practical and professional support during the child justice process. The similarities and differences between the contexts of child protection and child justice in supporting parents illuminates the existing gaps in child justice legislation, policy and practice resulting in a lack of support for parents during the child justice process. In the Children’s Act 38 of 2005, it is recognised that parents have a legal responsibility towards their children and that in fulfilling this responsibility parents can access support services to assist them when they face challenges in fulfilling this responsibility. In contrast, despite 80 percent of children in conflict with the law being released into parental care and parents expressing the need for support in fulfilling their parental responsibility, in this regard the Child Justice Act 75 of 2008 fails to make provision for parents to access support services. The child justice system’s narrow focus on parents as service extenders contributes to parents’ being excluded from targeted support services resulting in parents’ support needs not being addressed. The lack of programmes and services aimed at supporting parents highlight the need for coordinated services that address the multiple stressors parents are exposed to. To this end, this study was aimed at coconstructing a practice model for supporting parents of children in conflict with the law. The theoretical lenses employed in the current study namely; the Ecological systems model and the Buffering effect model describes the various systems parents need support from and the type of support they need from their family, community and professionals. Guided by a qualitative approach, the present study integrated applied research, in particular intervention design and development with participatory action research as it allowed systematic collaboration during the research process to ensure rigour. This study involved participants from two research sites namely, the Nerina One- Stop Child Justice Centre in Port Elizabeth and the Reception, Assessment and Referral office at the Uitenhage magistrates’ court. Employing a non-probability purposive sampling method, this study facilitated the participation of parents of children in conflict with the law and child justice officials who met the inclusion criteria, in the co-design and development of a practice model for supporting parents of children in conflict with the law. Participants assumed an expert and collaborative role, which enabled the co-construction of knowledge, meaning and innovation of the practice model. Qualitative data collection methods namely, twelve focus groups and thirty two participant observations, were used to explore, co-construct, describe and design a practice model for supporting parents of children in conflict with the law during the child justice process. Thematic analyses was employed to condense the data, search for codes, categories, themes, relationships and patterns in the data. Due to the research approach and design, data analysis was ongoing and informed design and development of the practice model. Based on the thematic analysis and synthesis both descriptive and analytic themes emerged. To ensure trustworthiness, this study employed various strategies to strengthen commitment, rigour, transparency and coherence. In addition, the participative research process, the inclusion of multiple forms of qualitative inquiry and the significance of the study contributed to the validity and quality of the study. Ethical considerations applicable to the study included participants’ voluntary participation, their informed consent and ensuring participants’ privacy or maintaining confidentially. Various strategies were employed to prevent or minimise risk to participants. The findings showed that formal sources of support, in particular, offer opportunities for parents to access individual and family counselling, parenting advice, and peer support. The study also highlighted the importance of recognising parents as a subsystem in the child justice system offers potential opportunities for inclusion of parents as co-facilitators of parenting programmes or support groups, as peer supporters during the child justice process. Parents’ inclusion as a partner in the child justice system is highlighted as an opportunity for parents to be able to vi participate in child justice fora, oversight committees and accreditation committees to influence policy, services and budget allocations for services to support parents of children in conflict with the law. This study’s contribution to the existing body of knowledge is an integrated, multidisciplinary, multi-phase co-constructed practice model that would enable inclusion of, and support for, parents of children in conflict with the law prior to, during and after the child justice. The co-constructed practice model (a) involves a continuum of parent-centred support for and inclusion of parents prior to, during and after the child justice process; (b) advances an inclusive and collaborative child justice system that views parents as important stakeholders in determining the type of services they need and being involved in developing practice; and (c) promotes parents as equal partners in decision making and policy making to influence legislation, policy and practice in the child justice system.
- Full Text:
- Date Issued: 2019
- Authors: Abdulla, Zurina
- Date: 2019
- Subjects: Children's rights -- South Africa , Children -- Legal status, laws, etc --South Africa , Parent and child -- Research -- South Africa , Social work with youth -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/30474 , vital:30949
- Description: The unique historical stressors linked to South Africa’s apartheid legacy, continues to manifest in the form of economic exclusion, social exclusion, inequality and poverty, with parents being subjugated to service users and extenders rather than included as service advocates, particularly in the child justice system. Furthermore, policies and practices do not include, engage and support parents on an intra and interpersonal level. Parents of children in conflict with the law, experience their children’s charge or arrest as well as their subsequent journey through the child justice system as a crisis resulting in their need for emotional, informational, practical and professional support during the child justice process. The similarities and differences between the contexts of child protection and child justice in supporting parents illuminates the existing gaps in child justice legislation, policy and practice resulting in a lack of support for parents during the child justice process. In the Children’s Act 38 of 2005, it is recognised that parents have a legal responsibility towards their children and that in fulfilling this responsibility parents can access support services to assist them when they face challenges in fulfilling this responsibility. In contrast, despite 80 percent of children in conflict with the law being released into parental care and parents expressing the need for support in fulfilling their parental responsibility, in this regard the Child Justice Act 75 of 2008 fails to make provision for parents to access support services. The child justice system’s narrow focus on parents as service extenders contributes to parents’ being excluded from targeted support services resulting in parents’ support needs not being addressed. The lack of programmes and services aimed at supporting parents highlight the need for coordinated services that address the multiple stressors parents are exposed to. To this end, this study was aimed at coconstructing a practice model for supporting parents of children in conflict with the law. The theoretical lenses employed in the current study namely; the Ecological systems model and the Buffering effect model describes the various systems parents need support from and the type of support they need from their family, community and professionals. Guided by a qualitative approach, the present study integrated applied research, in particular intervention design and development with participatory action research as it allowed systematic collaboration during the research process to ensure rigour. This study involved participants from two research sites namely, the Nerina One- Stop Child Justice Centre in Port Elizabeth and the Reception, Assessment and Referral office at the Uitenhage magistrates’ court. Employing a non-probability purposive sampling method, this study facilitated the participation of parents of children in conflict with the law and child justice officials who met the inclusion criteria, in the co-design and development of a practice model for supporting parents of children in conflict with the law. Participants assumed an expert and collaborative role, which enabled the co-construction of knowledge, meaning and innovation of the practice model. Qualitative data collection methods namely, twelve focus groups and thirty two participant observations, were used to explore, co-construct, describe and design a practice model for supporting parents of children in conflict with the law during the child justice process. Thematic analyses was employed to condense the data, search for codes, categories, themes, relationships and patterns in the data. Due to the research approach and design, data analysis was ongoing and informed design and development of the practice model. Based on the thematic analysis and synthesis both descriptive and analytic themes emerged. To ensure trustworthiness, this study employed various strategies to strengthen commitment, rigour, transparency and coherence. In addition, the participative research process, the inclusion of multiple forms of qualitative inquiry and the significance of the study contributed to the validity and quality of the study. Ethical considerations applicable to the study included participants’ voluntary participation, their informed consent and ensuring participants’ privacy or maintaining confidentially. Various strategies were employed to prevent or minimise risk to participants. The findings showed that formal sources of support, in particular, offer opportunities for parents to access individual and family counselling, parenting advice, and peer support. The study also highlighted the importance of recognising parents as a subsystem in the child justice system offers potential opportunities for inclusion of parents as co-facilitators of parenting programmes or support groups, as peer supporters during the child justice process. Parents’ inclusion as a partner in the child justice system is highlighted as an opportunity for parents to be able to vi participate in child justice fora, oversight committees and accreditation committees to influence policy, services and budget allocations for services to support parents of children in conflict with the law. This study’s contribution to the existing body of knowledge is an integrated, multidisciplinary, multi-phase co-constructed practice model that would enable inclusion of, and support for, parents of children in conflict with the law prior to, during and after the child justice. The co-constructed practice model (a) involves a continuum of parent-centred support for and inclusion of parents prior to, during and after the child justice process; (b) advances an inclusive and collaborative child justice system that views parents as important stakeholders in determining the type of services they need and being involved in developing practice; and (c) promotes parents as equal partners in decision making and policy making to influence legislation, policy and practice in the child justice system.
- Full Text:
- Date Issued: 2019
Rural-urban migration and its impact on rural development in Nigeria
- Authors: Abizu, Odion Stanley
- Date: 2018
- Subjects: Rural development Rural-urban migration -- Nigeria Rural poor
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/13815 , vital:39714
- Description: This thesis focuses on the developmental impact of rural-urban migration in Nigeria. While, recognising the negative impact of rural-urban migration, the study argues that in order to benefit internal migrants as well as rural development, there must be a paradigm shift to focus on how the benefits of migration on development can be achieved. It is proposed that rural-urban migration occurs as a response to economic, education, health, social and environmental factors. The challenges confronting rural areas are urban bias development paradigm pursued by the successive governments resulting in rural underdevelopment that exacerbates the rural urban disparity. And the neglect of agriculture in rural areas resulting from the discovery of oil in Nigeria. The study revealed that flawed policies adopted by successive Nigerian governments led to joblessness, entrenched social inequality and opportunities. One of the outcomes of these short-sighted policies was rural underdevelopment, which accelerated rural-urban migration in Nigeria. However, the study also demonstrates that the income flows from the migrants to the various rural households has contributed to improvement in the living standard of the households. The fragmentary approaches to rural development that is currently the case in Nigeria would not generate the required level of development and growth needed in the rural communities to improve the living standard. Thus, there is need for a policy framework in Nigeria, which would encourage the private sector to play a vital role in contributing their part in the provision of infrastructural facilities in the rural communities. Although this thesis is a case study of the impact of rural-urban migration on rural development in Nigeria, it can serve to appreciate the role migration can play in promoting development both in rural and urban areas in Nigeria and other Saharan Africa countries.
- Full Text:
- Date Issued: 2018
- Authors: Abizu, Odion Stanley
- Date: 2018
- Subjects: Rural development Rural-urban migration -- Nigeria Rural poor
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/13815 , vital:39714
- Description: This thesis focuses on the developmental impact of rural-urban migration in Nigeria. While, recognising the negative impact of rural-urban migration, the study argues that in order to benefit internal migrants as well as rural development, there must be a paradigm shift to focus on how the benefits of migration on development can be achieved. It is proposed that rural-urban migration occurs as a response to economic, education, health, social and environmental factors. The challenges confronting rural areas are urban bias development paradigm pursued by the successive governments resulting in rural underdevelopment that exacerbates the rural urban disparity. And the neglect of agriculture in rural areas resulting from the discovery of oil in Nigeria. The study revealed that flawed policies adopted by successive Nigerian governments led to joblessness, entrenched social inequality and opportunities. One of the outcomes of these short-sighted policies was rural underdevelopment, which accelerated rural-urban migration in Nigeria. However, the study also demonstrates that the income flows from the migrants to the various rural households has contributed to improvement in the living standard of the households. The fragmentary approaches to rural development that is currently the case in Nigeria would not generate the required level of development and growth needed in the rural communities to improve the living standard. Thus, there is need for a policy framework in Nigeria, which would encourage the private sector to play a vital role in contributing their part in the provision of infrastructural facilities in the rural communities. Although this thesis is a case study of the impact of rural-urban migration on rural development in Nigeria, it can serve to appreciate the role migration can play in promoting development both in rural and urban areas in Nigeria and other Saharan Africa countries.
- Full Text:
- Date Issued: 2018
An investigation of the attitudes of South African Police Service management with respect to the viability of computer-assisted training in the Eastern Cape Province
- Authors: Adams, Leinadu
- Date: 2011
- Subjects: Education -- South Africa -- Data processing , Education -- Computer-assisted instruction , Information technology -- Study and teaching -- South Africa , Police training -- South Africa , Police -- South Africa -- Attitudes
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:8190 , http://hdl.handle.net/10948/1410 , Education -- South Africa -- Data processing , Education -- Computer-assisted instruction , Information technology -- Study and teaching -- South Africa , Police training -- South Africa , Police -- South Africa -- Attitudes
- Description: The South African Police Service (SAPS) as a constituent part of the public service was established to deliver a specific category of services to the public. These services have to conform to requirements that are prescribed by various legislative provisions to promote effective and efficient delivery of public services. The implications of these provisions that are pursued by the study firstly, refer to the emphasis of government on the enhancement of public service delivery, with due consideration given to cost effectiveness and efficiency. Secondly, it refers to government's realisation of the important impact of education, development and training (EDT) on the competency of public service officials with an emphasis on the utilisation of information technology to enhance the effectiveness of EDT. Consequently, the study explores the viability of the utilisation of information technology as a measure to assist EDT interventions within the SAPS of the Eastern Cape Province to equip members of the institution to better fulfil their functions and duties. In this respect the study commenced to ascertain the levels of computer literacy of role-players, access to the appropriate facilities and what the general attitude in the organisation would be towards the utilisation of such an intervention. It was found that the computer literacy levels of role-players may be perceived as a problematic issue in this regard. However, access to suitable facilities was found to be more than sufficient for this intention. Furthermore, role-players agreed that information technology could be optimally applied in the EC SAPS for the mentioned use, thereby portraying an optimistic attitude towards the use thereof to harmonise EDT in the SAPS. The aim of the study has been to develop a model that will incorporate the use of information technology, given the strengths and weaknesses of the SAPS to enhance EDT and learning in the organization.
- Full Text:
- Date Issued: 2011
- Authors: Adams, Leinadu
- Date: 2011
- Subjects: Education -- South Africa -- Data processing , Education -- Computer-assisted instruction , Information technology -- Study and teaching -- South Africa , Police training -- South Africa , Police -- South Africa -- Attitudes
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:8190 , http://hdl.handle.net/10948/1410 , Education -- South Africa -- Data processing , Education -- Computer-assisted instruction , Information technology -- Study and teaching -- South Africa , Police training -- South Africa , Police -- South Africa -- Attitudes
- Description: The South African Police Service (SAPS) as a constituent part of the public service was established to deliver a specific category of services to the public. These services have to conform to requirements that are prescribed by various legislative provisions to promote effective and efficient delivery of public services. The implications of these provisions that are pursued by the study firstly, refer to the emphasis of government on the enhancement of public service delivery, with due consideration given to cost effectiveness and efficiency. Secondly, it refers to government's realisation of the important impact of education, development and training (EDT) on the competency of public service officials with an emphasis on the utilisation of information technology to enhance the effectiveness of EDT. Consequently, the study explores the viability of the utilisation of information technology as a measure to assist EDT interventions within the SAPS of the Eastern Cape Province to equip members of the institution to better fulfil their functions and duties. In this respect the study commenced to ascertain the levels of computer literacy of role-players, access to the appropriate facilities and what the general attitude in the organisation would be towards the utilisation of such an intervention. It was found that the computer literacy levels of role-players may be perceived as a problematic issue in this regard. However, access to suitable facilities was found to be more than sufficient for this intention. Furthermore, role-players agreed that information technology could be optimally applied in the EC SAPS for the mentioned use, thereby portraying an optimistic attitude towards the use thereof to harmonise EDT in the SAPS. The aim of the study has been to develop a model that will incorporate the use of information technology, given the strengths and weaknesses of the SAPS to enhance EDT and learning in the organization.
- Full Text:
- Date Issued: 2011
A framework for cloud computing adoption in small and medium-sized enterprises : a case of the Accra - Tema metropolis in Ghana
- Authors: Adane, Martin
- Date: 2015
- Subjects: Cloud computing -- Ghana Small business -- Ghana
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/13803 , vital:39713
- Description: Cloud computing adoption and usage is important to achieving business competition. This is done by making it a competitive tool for firms. The adoption of cloud computing enables firms to achieve greater business competency, improve performance, and allows them to maintain their competitive advantage. Since its emergence, there has been a surge in the adoption of cloud computing with research into its adoption primarily concentrated on bigger firms. However, a major characteristic of cloud computing is the anticipated possibilities it holds for small and medium-sized enterprises (SMEs). SMEs typically operate differently from larger firms and are not limited by resource constraints. For SMEs, the reduction in the financial burden normally associated with the adoption of new technologies is a significant benefit of cloud computing due to their financial constraints. In Ghana, SMEs mostly use obsolete technologies and have a slow response towards new technologies. Thus, they are unable to harness the numerous opportunities technology presents to them to stay competitive. Cloud computing is still regarded as a new technology in the business world, therefore research that focuses on its adoption by SMEs to help them stay competitive is minimal. Available research on cloud computing in Ghana does not provide clear guidelines for ensuring a successful adoption process and the continued use of cloud computing services. This study seeks to investigate how a framework can assist SMEs in their use of cloud computing in the Accra-Tema metropolis of Ghana. A knowledge of the factors associated with adoption decisions and those that significantly influence the decision are required to ensure a successful adoption process. The empirical data was gathered using a questionnaire and face-to-face interviews developed from literature and administered to users and potential users of cloud computing. The questionnaire and interviews primarily investigate key adoption factors and the findings are reported in this research study. The findings reveal interesting insights into understanding issues that affect the overall decision to adopt and use cloud computing services by SMEs. The findings show that the adoption of cloud computing can improve information management practices within SMEs. The findings also reveal that several factors need to be considered in the overall decision to adopt and use cloud computing to ensure a successful adoption process. An initial cloud computing adoption model was proposed based on the empirical findings. Key adoption factors of the initial adoption model include adoption benefits and drivers, concerns and barriers, adoption interventions, and information management in the cloud. computing adoption framework. The proposed adoption framework aims to assist SMEs to adopt and use cloud computing services and make them relevant in the global market.
- Full Text:
- Date Issued: 2015
- Authors: Adane, Martin
- Date: 2015
- Subjects: Cloud computing -- Ghana Small business -- Ghana
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/13803 , vital:39713
- Description: Cloud computing adoption and usage is important to achieving business competition. This is done by making it a competitive tool for firms. The adoption of cloud computing enables firms to achieve greater business competency, improve performance, and allows them to maintain their competitive advantage. Since its emergence, there has been a surge in the adoption of cloud computing with research into its adoption primarily concentrated on bigger firms. However, a major characteristic of cloud computing is the anticipated possibilities it holds for small and medium-sized enterprises (SMEs). SMEs typically operate differently from larger firms and are not limited by resource constraints. For SMEs, the reduction in the financial burden normally associated with the adoption of new technologies is a significant benefit of cloud computing due to their financial constraints. In Ghana, SMEs mostly use obsolete technologies and have a slow response towards new technologies. Thus, they are unable to harness the numerous opportunities technology presents to them to stay competitive. Cloud computing is still regarded as a new technology in the business world, therefore research that focuses on its adoption by SMEs to help them stay competitive is minimal. Available research on cloud computing in Ghana does not provide clear guidelines for ensuring a successful adoption process and the continued use of cloud computing services. This study seeks to investigate how a framework can assist SMEs in their use of cloud computing in the Accra-Tema metropolis of Ghana. A knowledge of the factors associated with adoption decisions and those that significantly influence the decision are required to ensure a successful adoption process. The empirical data was gathered using a questionnaire and face-to-face interviews developed from literature and administered to users and potential users of cloud computing. The questionnaire and interviews primarily investigate key adoption factors and the findings are reported in this research study. The findings reveal interesting insights into understanding issues that affect the overall decision to adopt and use cloud computing services by SMEs. The findings show that the adoption of cloud computing can improve information management practices within SMEs. The findings also reveal that several factors need to be considered in the overall decision to adopt and use cloud computing to ensure a successful adoption process. An initial cloud computing adoption model was proposed based on the empirical findings. Key adoption factors of the initial adoption model include adoption benefits and drivers, concerns and barriers, adoption interventions, and information management in the cloud. computing adoption framework. The proposed adoption framework aims to assist SMEs to adopt and use cloud computing services and make them relevant in the global market.
- Full Text:
- Date Issued: 2015
A multi-stakeholder approach to productivity improvement in the South African construction industry
- Authors: Adebowale, Oluseyi Julius
- Date: 2018
- Subjects: Labor productivity , Construction industry -- Labor productivity Construction industry -- South Africa Construction industry -- Management
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/19597 , vital:28902
- Description: As poor productivity in construction continues to constitute a setback to projects’ success in different countries of the world, the situation in South African construction is no exception. Poor productivity on construction projects and its detrimental impact on project objectives have continually resonated for decades. As a result, several strategies, interventions, and measures that aimed at improving productivity in the construction sector have been proposed. Nevertheless, the phenomenon importunately creates a major challenge on construction projects, and by extension, the construction industry especially in developing countries. Even when construction management literature acknowledged the commonalities in productivity influences, the practice of addressing construction productivity influences as separate entities has gained much relevance over the years. Taking into perspective, the multidisciplinary and complexity inherent in construction, a systemic approach to addressing construction productivity influences is fast becoming essential. This study addressed productivity-influencing factors by considering factors that are related to rework, shortage of construction resources, constructability, political, socio-economic, working environment, welfare conditions, disputes, planning and training. Consequently, the interdependencies of the most significant productivity-influencing factors in South African construction was developed in the form of a qualitative model. The study adopts the underlying assumptions of the quantitative approach, but also accepts some qualitative data. With regards to the subject of enquiry, the paradigm of the research is positivism which consists of realists’ ontological prescriptions and objectivists’ epistemological prescriptions. Site engineers, site managers, and site supervisors working for cidb registered contractors in four South African provinces constitute the sample stratum. Statistical Package for the Social Sciences (SPSS) version 24 was used to analyse the data gathered from these project participants; both descriptive and inferential statistics were used. Descriptive statistics was used to summarise and describe the data obtained, while inferential statistics in the form of analysis of variance, T-test, and Tukey post hoc test were adopted. The study reported the most significant factors which negatively influence productivity on South African construction projects as inadequate workers’ skills, defective workmanship, the practice of awarding contracts to lowest bidders, political activities resulting in industrial action, inadequate contractors’ experience in project planning, payment delays by contractors, and corruption. Furthermore, it was found that contractors largely share similar perceptions regarding the factors that constrain productivity growth in South African construction. The approximate level of labour, material, and plant productivity on South African construction projects is 50.4%, 72.9%, and 62.0% respectively, while the approximate multifactor productivity was estimated as 61.8%. The study concluded that productivity has a considerable relationship with time and cost and a less potent relationship with quality. Based on the research findings, contractors’, consultants’, clients’ and government qualitative intervention models were proposed while recommendations towards improving South African construction productivity were made. The study recommended the reinvention of the apprentice training system to develop skills in construction, the involvement of stakeholders in improving workers’ skills, improved collaboration between the construction industry and higher institutions of learning regarding curricula development, adequate supervision of construction activities to mitigate the propagation of rework on construction projects, character in leadership, and integrity of project stakeholders.
- Full Text:
- Date Issued: 2018
- Authors: Adebowale, Oluseyi Julius
- Date: 2018
- Subjects: Labor productivity , Construction industry -- Labor productivity Construction industry -- South Africa Construction industry -- Management
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/19597 , vital:28902
- Description: As poor productivity in construction continues to constitute a setback to projects’ success in different countries of the world, the situation in South African construction is no exception. Poor productivity on construction projects and its detrimental impact on project objectives have continually resonated for decades. As a result, several strategies, interventions, and measures that aimed at improving productivity in the construction sector have been proposed. Nevertheless, the phenomenon importunately creates a major challenge on construction projects, and by extension, the construction industry especially in developing countries. Even when construction management literature acknowledged the commonalities in productivity influences, the practice of addressing construction productivity influences as separate entities has gained much relevance over the years. Taking into perspective, the multidisciplinary and complexity inherent in construction, a systemic approach to addressing construction productivity influences is fast becoming essential. This study addressed productivity-influencing factors by considering factors that are related to rework, shortage of construction resources, constructability, political, socio-economic, working environment, welfare conditions, disputes, planning and training. Consequently, the interdependencies of the most significant productivity-influencing factors in South African construction was developed in the form of a qualitative model. The study adopts the underlying assumptions of the quantitative approach, but also accepts some qualitative data. With regards to the subject of enquiry, the paradigm of the research is positivism which consists of realists’ ontological prescriptions and objectivists’ epistemological prescriptions. Site engineers, site managers, and site supervisors working for cidb registered contractors in four South African provinces constitute the sample stratum. Statistical Package for the Social Sciences (SPSS) version 24 was used to analyse the data gathered from these project participants; both descriptive and inferential statistics were used. Descriptive statistics was used to summarise and describe the data obtained, while inferential statistics in the form of analysis of variance, T-test, and Tukey post hoc test were adopted. The study reported the most significant factors which negatively influence productivity on South African construction projects as inadequate workers’ skills, defective workmanship, the practice of awarding contracts to lowest bidders, political activities resulting in industrial action, inadequate contractors’ experience in project planning, payment delays by contractors, and corruption. Furthermore, it was found that contractors largely share similar perceptions regarding the factors that constrain productivity growth in South African construction. The approximate level of labour, material, and plant productivity on South African construction projects is 50.4%, 72.9%, and 62.0% respectively, while the approximate multifactor productivity was estimated as 61.8%. The study concluded that productivity has a considerable relationship with time and cost and a less potent relationship with quality. Based on the research findings, contractors’, consultants’, clients’ and government qualitative intervention models were proposed while recommendations towards improving South African construction productivity were made. The study recommended the reinvention of the apprentice training system to develop skills in construction, the involvement of stakeholders in improving workers’ skills, improved collaboration between the construction industry and higher institutions of learning regarding curricula development, adequate supervision of construction activities to mitigate the propagation of rework on construction projects, character in leadership, and integrity of project stakeholders.
- Full Text:
- Date Issued: 2018
Evaluation of the incidence of enteric viruses, Vibrio species and Escherichia coli pathotypes in effluents of two wastewater treatment plants located in Keiskammahoek and Stutterheim in the Eastern Cape Province of South Africa
- Authors: Adefisoye, Martins Ajibade
- Date: 2016
- Subjects: Escherichia coli -- South Africa -- Eastern Cape Water -- Purification -- South Africa -- Eastern Cape Effluent quality -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/3165 , vital:28328
- Description: South Africa is currently experiencing water shortage crisis, a challenge that has been attributed not only to the scarcity of freshwater, but also to fast degrading water quality. Factors such as rapid urbanisation, population and economic growth, climate change as well as poor operational and maintenance of many of the exisiting water/wastewater treatment facilities have been acknowledged as important contributors to degrading water quality in the country. Untreated or inadequately treated discharged wastewater effluents constitute point source pollution to many freshwater environments in South Africa. Hence, it becomes imperative to evaluate wastewater discharges in other to protect the scarce freshwater resource, the environment and public health. Over a twelve-month sampling period (September 2012 to August 2013), we assessed the bacteriological, virological and physicochemical qualities of the discharged final effluents of two wastewater treatment facilities in the Eastern Cape Province of South Africa. For the physicochemical assessment, a total of 144 final effluent samples were collected from both the final effluent tanks (FE) and the discharge points (DP) of the treatment facilities. Physicochemical parameters including pH, temperature, turbidity, total dissolved solids (TDS), dissolved oxygen (DO), electrical conductivity (EC) and free chlorine concentration were determined on site while biological oxygen demand (BOD), nitrate (NO3-), nitrite (NO2-), phosphate (PO4-) and chemical oxygen demand (COD) were determined in the laboratory. The bacteriological analysis of the samples was done using standard membrane filtration (MF) technique. Bacterial group assessed included: faecal indicator bacteria (faecal coliforms and E. coli) and Vibrio species, while the antibiotic susceptibility profiles of selected E. coli and Vibrio species isolates against some selected antibiotics commonly used in human therapy and veterinary medicine were determind using the standard agar-disc diffusion method. The occurrence and concentrations of human enteric viruses including: human adenovirus (HAdV), hepatitis A virus (HAV) and rotavirus (RoV) in the samples were determined by TaqMan-based real-time polymerase chain reaction (qPCR) following concentration by adsorption-elution method. The physicochemical characteristics of the samples ranged as follows: pH (6.5 – 7.6), TDS (95 – 171 mg/L), EC (134 – 267 μS/cm), temperature (12 – 27 °C), turbidity (1.5 – 65.7 mg/L), free chlorine (0.08 – 0.72 mg/L), DO (2.06 – 9.81 mg/L), BOD (0.13 – 9.81 mg/L), NO3- (0 – 21.5 mg/L), NO2- (0 – 0.72 mg/L), PO4- (0 – 18.3 mg/L) and COD (27 – 680 mg/L). Some of the characteristic such as pH, TDS, EC, temperature, nitrite and DO (on most instances) complied with recommended guidelines. Other characteristics, however, including turbidity, BOD, nitrate, phosphate and COD fell short of the recommended guidelines. All the 48 samples analysed for bacteriological qualities tested positive for the presence of the bacterial groups with significant (P≤0.05) seasonal variation in their densities. Faecal coliforms were detected in counts ranging from 1 CFU/100ml to 2.7 × 104 CFU/100ml. Presumptive E. coli counts ranged generally between 1 CFU/100ml – 1.4 × 105 CFU/100ml while counts of presumptive Vibrio species ranged between 4 CFU/100ml – 1.4 × 104 CFU/100ml. Molecular identification of the presumptive isolates by polymerase chain reactions PCR gave positive reaction rates of 76.2 percent (381/500) and 69.8 percent (279/400) for E.coli and Vibrio species respectively. The antibiotic susceptibility profiling of 205 PCR-confirmed Vibiro isolates against 18 commomly used antibiotics showed resistance frequencies ranging from 0.5 percent (imipenem) to 96.1 percent (penicillin G) at recommended breakpoint concentrations. Eighty-one percent (166/205) of the Vibrio isolates showed multidrug resistance (resistance to 3 or more antibiotics) with the most common multiple antibiotic resistance phenotype (MARP) being AP-T-TM-SMX-PG-NI-PB, occurring in 8 isolates.
- Full Text:
- Date Issued: 2016
- Authors: Adefisoye, Martins Ajibade
- Date: 2016
- Subjects: Escherichia coli -- South Africa -- Eastern Cape Water -- Purification -- South Africa -- Eastern Cape Effluent quality -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/3165 , vital:28328
- Description: South Africa is currently experiencing water shortage crisis, a challenge that has been attributed not only to the scarcity of freshwater, but also to fast degrading water quality. Factors such as rapid urbanisation, population and economic growth, climate change as well as poor operational and maintenance of many of the exisiting water/wastewater treatment facilities have been acknowledged as important contributors to degrading water quality in the country. Untreated or inadequately treated discharged wastewater effluents constitute point source pollution to many freshwater environments in South Africa. Hence, it becomes imperative to evaluate wastewater discharges in other to protect the scarce freshwater resource, the environment and public health. Over a twelve-month sampling period (September 2012 to August 2013), we assessed the bacteriological, virological and physicochemical qualities of the discharged final effluents of two wastewater treatment facilities in the Eastern Cape Province of South Africa. For the physicochemical assessment, a total of 144 final effluent samples were collected from both the final effluent tanks (FE) and the discharge points (DP) of the treatment facilities. Physicochemical parameters including pH, temperature, turbidity, total dissolved solids (TDS), dissolved oxygen (DO), electrical conductivity (EC) and free chlorine concentration were determined on site while biological oxygen demand (BOD), nitrate (NO3-), nitrite (NO2-), phosphate (PO4-) and chemical oxygen demand (COD) were determined in the laboratory. The bacteriological analysis of the samples was done using standard membrane filtration (MF) technique. Bacterial group assessed included: faecal indicator bacteria (faecal coliforms and E. coli) and Vibrio species, while the antibiotic susceptibility profiles of selected E. coli and Vibrio species isolates against some selected antibiotics commonly used in human therapy and veterinary medicine were determind using the standard agar-disc diffusion method. The occurrence and concentrations of human enteric viruses including: human adenovirus (HAdV), hepatitis A virus (HAV) and rotavirus (RoV) in the samples were determined by TaqMan-based real-time polymerase chain reaction (qPCR) following concentration by adsorption-elution method. The physicochemical characteristics of the samples ranged as follows: pH (6.5 – 7.6), TDS (95 – 171 mg/L), EC (134 – 267 μS/cm), temperature (12 – 27 °C), turbidity (1.5 – 65.7 mg/L), free chlorine (0.08 – 0.72 mg/L), DO (2.06 – 9.81 mg/L), BOD (0.13 – 9.81 mg/L), NO3- (0 – 21.5 mg/L), NO2- (0 – 0.72 mg/L), PO4- (0 – 18.3 mg/L) and COD (27 – 680 mg/L). Some of the characteristic such as pH, TDS, EC, temperature, nitrite and DO (on most instances) complied with recommended guidelines. Other characteristics, however, including turbidity, BOD, nitrate, phosphate and COD fell short of the recommended guidelines. All the 48 samples analysed for bacteriological qualities tested positive for the presence of the bacterial groups with significant (P≤0.05) seasonal variation in their densities. Faecal coliforms were detected in counts ranging from 1 CFU/100ml to 2.7 × 104 CFU/100ml. Presumptive E. coli counts ranged generally between 1 CFU/100ml – 1.4 × 105 CFU/100ml while counts of presumptive Vibrio species ranged between 4 CFU/100ml – 1.4 × 104 CFU/100ml. Molecular identification of the presumptive isolates by polymerase chain reactions PCR gave positive reaction rates of 76.2 percent (381/500) and 69.8 percent (279/400) for E.coli and Vibrio species respectively. The antibiotic susceptibility profiling of 205 PCR-confirmed Vibiro isolates against 18 commomly used antibiotics showed resistance frequencies ranging from 0.5 percent (imipenem) to 96.1 percent (penicillin G) at recommended breakpoint concentrations. Eighty-one percent (166/205) of the Vibrio isolates showed multidrug resistance (resistance to 3 or more antibiotics) with the most common multiple antibiotic resistance phenotype (MARP) being AP-T-TM-SMX-PG-NI-PB, occurring in 8 isolates.
- Full Text:
- Date Issued: 2016
A management model for human settlements: a case study of Nigeria and South Africa
- Authors: Adeniran, Adeleye Ayoade
- Date: 2020
- Subjects: Human settlements -- Nigeria , Human settlements -- South Africa Sustainable development
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/45985 , vital:39403
- Description: Persistent depreciating human settlements is a global challenge, particularly in developing countries and this challenge contributes to the continuously increasing housing gap, despite several novel policies and programmes. Although there is a dearth of research-based literature on human settlements management, studies show that property management, Facility Management, housing management and urban management impact the sustainability of all these built environment milieus which form part of the human settlements’ sub-components. This research aimed at altering the afore-said challenge by exploring the management of human settlements in Nigeria and in South Africa. Philosophically, the research is pragmatic, and it rests on positivist deductive reasoning. The methods used for data collection include a review of literature, collection of archival records, and empirical studies of purposively selected professionals and stakeholders involved in human settlements’ management in Nigeria and in South Africa. The findings indicate that existing human settlements in the case studies are “good” and “acceptable” with the majority adopting an outsourced method of management. Furthermore, the lack of maintenance records, the deficiency in policy monitoring and the training of management and maintenance personnel were the three highest ranking factors indicated to be affecting human settlements management. Moreover, an inhabitant’s income, the time available for management, professional expertise and technology employed for management are recognised as the critical sustainability sub-factors affecting human settlement management. The factor analysis established ownership, human resource and capital, social, legal, technology, economic, physical and environmental factors as vital and very significant in achieving sustainable management of human settlements. The study recommends the professionalisation of the field of human settlements as well as a formulation of management policy among others. The study developed a management model for human settlements, and it advocates that human settlements managers, owners and organisations should apply the model in this study, to improve their human settlement management practices, so as to achieve sustainability, and in essence, Sustainable Development Goal 11. It is hoped that the suggested management model will influence human settlement policy development and review, the designing of human settlement management programmes including the framework for their ongoing monitoring and evaluation. The study furthermore contributes to the development of housing and human settlement curricula and evolving human settlement research in both developed and developing countries.
- Full Text:
- Date Issued: 2020
- Authors: Adeniran, Adeleye Ayoade
- Date: 2020
- Subjects: Human settlements -- Nigeria , Human settlements -- South Africa Sustainable development
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/45985 , vital:39403
- Description: Persistent depreciating human settlements is a global challenge, particularly in developing countries and this challenge contributes to the continuously increasing housing gap, despite several novel policies and programmes. Although there is a dearth of research-based literature on human settlements management, studies show that property management, Facility Management, housing management and urban management impact the sustainability of all these built environment milieus which form part of the human settlements’ sub-components. This research aimed at altering the afore-said challenge by exploring the management of human settlements in Nigeria and in South Africa. Philosophically, the research is pragmatic, and it rests on positivist deductive reasoning. The methods used for data collection include a review of literature, collection of archival records, and empirical studies of purposively selected professionals and stakeholders involved in human settlements’ management in Nigeria and in South Africa. The findings indicate that existing human settlements in the case studies are “good” and “acceptable” with the majority adopting an outsourced method of management. Furthermore, the lack of maintenance records, the deficiency in policy monitoring and the training of management and maintenance personnel were the three highest ranking factors indicated to be affecting human settlements management. Moreover, an inhabitant’s income, the time available for management, professional expertise and technology employed for management are recognised as the critical sustainability sub-factors affecting human settlement management. The factor analysis established ownership, human resource and capital, social, legal, technology, economic, physical and environmental factors as vital and very significant in achieving sustainable management of human settlements. The study recommends the professionalisation of the field of human settlements as well as a formulation of management policy among others. The study developed a management model for human settlements, and it advocates that human settlements managers, owners and organisations should apply the model in this study, to improve their human settlement management practices, so as to achieve sustainability, and in essence, Sustainable Development Goal 11. It is hoped that the suggested management model will influence human settlement policy development and review, the designing of human settlement management programmes including the framework for their ongoing monitoring and evaluation. The study furthermore contributes to the development of housing and human settlement curricula and evolving human settlement research in both developed and developing countries.
- Full Text:
- Date Issued: 2020
In vivo toxicological evaluation of peptide conjugated gold nanoparticles for potential application in colorectal cancer diagnosis
- Authors: Adewale, Olusola Bolaji
- Date: 2018
- Subjects: Nanostructured materials -- Toxicology , Colon (Anatomy) -- Cancer Rectum -- Cancer
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/50133 , vital:42050
- Description: Colorectal cancer (CRC) is among the leading cause of cancer-related deaths in South Africa and worldwide. Efforts are being made at finding improved diagnostic tools, as early detection (before metastasis) is a major factor in CRC treatment. Colonoscopy is the most reliable detection method, but is a specialised and expensive procedure, which is invasive, not readily available and not patient-friendly. There is a risk of developing interval cancers, as colonoscopies are performed every 10 years after the age of 40. The development of non-invasive, cost efficient and readily available diagnostic tools to CRC, which can be performed at more regular intervals, using tumour-targeting molecular imaging agents, is of urgent attention. Gold nanoparticles (AuNPs) possess several physicochemical properties, including ease of synthesis, biocompatibility, and the ability to be conjugated by ligands or biomolecules such as polyethylene glycol (PEG) and peptides for improved stability, tissue targeting and selectivity. These factors potentiate the role in biomedical applications, including cancer theranostics. Conjugation of AuNPs with a targeting molecule (e.g. antibody or peptide) is directed against cancer cell receptors. The peptides, p.C, p.L, and p.14, bind to CRC cells in vitro. Conjugation of AuNPs with these peptides should be investigated for CRC diagnosis in vivo, as it is hypothesised to allow examinations at shorter intervals through imaging techniques. This could reduce the risk of interval cancers, but before developing this novel tool, in vivo toxicity evaluations are essential. This study was therefore aimed at investigating the short- and long-term toxicological effects of a single intravenous injection of peptides (p.C, p.L, and p.14) conjugated to AuNPs in a healthy rat model. Citrate-capped AuNPs were synthesised by the citrate-reduction method, and conjugated with each peptide (biotinylated) using a combination of PEG (99% PEG-OH and 1% PEG-biotin) as a stabilising agent and linker, via biotin-streptavidin interaction. Healthy male Wistar rats were intravenously injected with 14 nm citrate-AuNPs, PEG-, p.C-PEG, p.L-PEG, and p.14-PEG-AuNPs (100 μg/kg body weight), and the control rats were injected with phosphate buffered saline. The animals were monitored for behavioural, physiological, biochemical, haematological and histological changes, as well as inflammatory responses. Phase 1 rats were sacrificed 2 weeks post-injection to determine the immediate or acute toxicity of the AuNPs, while phase 2 animals were sacrificed 12 weeks post-injection, to investigate the delayed or persistence toxicity of the AuNPs. Results revealed no significant toxicities with the citrate, PEG-, p.C-PEG and p.14-PEG-AuNPs over 12 weeks post-exposure, as evidenced by biochemical assays such as serum marker enzymes, liver and kidney function markers, and cholestatic indicators; haematological parameters; oxidative stress markers; and histopathological examinations. P.L-PEG-AuNPs, however, caused significant toxicity (p<0.05) to rats, as evidenced by increased relative liver weight, increased malondialdehyde levels, and total white blood cell counts 2 weeks post-exposure when compared to the control group. This was, however, reversed during the 12 weeks post-exposure. Further, there were no evidence of inflammatory responses, using pro-inflammatory markers including phospho interleukin 18 (IL-18) and interferon-γ (IFN-γ), as indicated by immunohistochemical staining of the liver, spleen, kidney and colon of rats 2 weeks post-injection of AuNPs. Citrate, PEG-, p.C-PEG, and p.14-PEG-AuNPs did not induce immediate, acute or persistent toxicity, while p.L-PEG-AuNPs induced a transient acute toxicity. It can be concluded that 14 nm spherical citrate-AuNPs at 100 μg/kg body weight is a good candidate for biomedical applications, and as a suitable carrier for diagnostic and/or therapeutic molecules. Combination of 99% PEG-OH and 1% PEG-biotin is an appropriate option for stabilising AuNPs in biological environment, and conjugating secondary diagnostic or therapeutic biomolecules or agents to citrate-capped AuNPs. Peptide-conjugated AuNPs are suitable for the development into a diagnostic tool for CRC in vivo.
- Full Text:
- Date Issued: 2018
- Authors: Adewale, Olusola Bolaji
- Date: 2018
- Subjects: Nanostructured materials -- Toxicology , Colon (Anatomy) -- Cancer Rectum -- Cancer
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/50133 , vital:42050
- Description: Colorectal cancer (CRC) is among the leading cause of cancer-related deaths in South Africa and worldwide. Efforts are being made at finding improved diagnostic tools, as early detection (before metastasis) is a major factor in CRC treatment. Colonoscopy is the most reliable detection method, but is a specialised and expensive procedure, which is invasive, not readily available and not patient-friendly. There is a risk of developing interval cancers, as colonoscopies are performed every 10 years after the age of 40. The development of non-invasive, cost efficient and readily available diagnostic tools to CRC, which can be performed at more regular intervals, using tumour-targeting molecular imaging agents, is of urgent attention. Gold nanoparticles (AuNPs) possess several physicochemical properties, including ease of synthesis, biocompatibility, and the ability to be conjugated by ligands or biomolecules such as polyethylene glycol (PEG) and peptides for improved stability, tissue targeting and selectivity. These factors potentiate the role in biomedical applications, including cancer theranostics. Conjugation of AuNPs with a targeting molecule (e.g. antibody or peptide) is directed against cancer cell receptors. The peptides, p.C, p.L, and p.14, bind to CRC cells in vitro. Conjugation of AuNPs with these peptides should be investigated for CRC diagnosis in vivo, as it is hypothesised to allow examinations at shorter intervals through imaging techniques. This could reduce the risk of interval cancers, but before developing this novel tool, in vivo toxicity evaluations are essential. This study was therefore aimed at investigating the short- and long-term toxicological effects of a single intravenous injection of peptides (p.C, p.L, and p.14) conjugated to AuNPs in a healthy rat model. Citrate-capped AuNPs were synthesised by the citrate-reduction method, and conjugated with each peptide (biotinylated) using a combination of PEG (99% PEG-OH and 1% PEG-biotin) as a stabilising agent and linker, via biotin-streptavidin interaction. Healthy male Wistar rats were intravenously injected with 14 nm citrate-AuNPs, PEG-, p.C-PEG, p.L-PEG, and p.14-PEG-AuNPs (100 μg/kg body weight), and the control rats were injected with phosphate buffered saline. The animals were monitored for behavioural, physiological, biochemical, haematological and histological changes, as well as inflammatory responses. Phase 1 rats were sacrificed 2 weeks post-injection to determine the immediate or acute toxicity of the AuNPs, while phase 2 animals were sacrificed 12 weeks post-injection, to investigate the delayed or persistence toxicity of the AuNPs. Results revealed no significant toxicities with the citrate, PEG-, p.C-PEG and p.14-PEG-AuNPs over 12 weeks post-exposure, as evidenced by biochemical assays such as serum marker enzymes, liver and kidney function markers, and cholestatic indicators; haematological parameters; oxidative stress markers; and histopathological examinations. P.L-PEG-AuNPs, however, caused significant toxicity (p<0.05) to rats, as evidenced by increased relative liver weight, increased malondialdehyde levels, and total white blood cell counts 2 weeks post-exposure when compared to the control group. This was, however, reversed during the 12 weeks post-exposure. Further, there were no evidence of inflammatory responses, using pro-inflammatory markers including phospho interleukin 18 (IL-18) and interferon-γ (IFN-γ), as indicated by immunohistochemical staining of the liver, spleen, kidney and colon of rats 2 weeks post-injection of AuNPs. Citrate, PEG-, p.C-PEG, and p.14-PEG-AuNPs did not induce immediate, acute or persistent toxicity, while p.L-PEG-AuNPs induced a transient acute toxicity. It can be concluded that 14 nm spherical citrate-AuNPs at 100 μg/kg body weight is a good candidate for biomedical applications, and as a suitable carrier for diagnostic and/or therapeutic molecules. Combination of 99% PEG-OH and 1% PEG-biotin is an appropriate option for stabilising AuNPs in biological environment, and conjugating secondary diagnostic or therapeutic biomolecules or agents to citrate-capped AuNPs. Peptide-conjugated AuNPs are suitable for the development into a diagnostic tool for CRC in vivo.
- Full Text:
- Date Issued: 2018
Synthesis, characterization and evaluation of photophysical and electrochemical properties of ruthenium(II) complexes for dye-sensitized solar cells
- Authors: Adjogri, Shadrack John
- Date: 2018
- Subjects: Ruthenium Ruthenium compounds
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/17828 , vital:41363
- Description: Eight series of thirty (30) novel heteroleptic ruthenium(II) complexes were designed, synthesized and spectroscopically characterized, with the following general molecular formulae as [Ru(bdmpmar)(H2dcbpy)(NCS)]+, [Ru(bdmpmar)(vpdiinp)(H2dcbpy)]2,+, [Ru(bdmpmar)(vpbpp)(H2dcbpy)]2+,[Ru(H2dcbpy)2(N^)(NCS)]+, [Ru(H2dcbpy)2(N^)2]2+, [Ru(H2dcbpy)(N^)2(NCS)2], [Ru(H2dcbpy)(N^)(NCS)3]– and [Ru(vptpy)(H2dcbpy)(N^^^)]2+ where bdmpmar is a tridentate ligand of N,N-bis(3, 5-dimethylpyrazol-1-yl-methyl) aromatic organic compound (such aromatic organic compounds(Ar) are anthranilic acid, 4-methoxy-2-nitroaniline, aniline, toluidine, cyclohexylamine and anisidine), vpdiinp represents a monodentate ligand of 11-(4-vinylphenyl)diindeno[1,2-b:2’,1’-e]pyridine, vpbpp represents a monodentate ligand of 4-(4-vinylphenyl)-2.6-bis(phenyl)pyridine and vptpy represents a tridentate ligand of 4’-(4-vinyl)-2,2’:6’,2’’-terpyridine. Meanwhile, N^ represents any of the monodentate ligands of either vpdiinp or vpbpp and (N^^^) represents any of the monodentate ligands either of vpdiinp or vpbpp or NCS as disclosed in series VIII. The complexes were characterized by conductivity measurement, solubility, melting point, UV-Vis, PL, FTIR (ATR), NMR, Cyclic and square wave voltammetry. Nine chelating ligands, comprising of six (6) tripodal chelating ligands, two (2) vinyl monodentate ligands and one (1) vinyl tridentate ligand, were used for the synthesis of ruthenium(II) complexes ATR-FTIR spectra of all the ruthenium(II) complexes measured as solid samples, exhibited fine resolution IR bands in region between 3473-3438 cm-1 of carboxylic group in H2dcbpy. The bands in the range 3040-2950 cm-1 were ascribed to C-H bond stretching for the CH3 groups. The coordination of NCS group in the sphere of ruthenium(II) complexes related to series I, IV, VI VII and one compound of series VIII was investigated by ATR-FTIR spectroscopy. Bands in the range of 2116-2106 cm-1 and 777-770 cm-1 are ascribed to the respective N=C and the C=S bond stretching vibration which confirms the N-coordination of the SCN group. For all the complexes, the stretching vibration of Ru-N bonding was between 466 and 411 cm-1 due to coordination of the nitrogen atoms of the ligands to ruthenium central metal atom. The introduction of the two vinyl monodentate ligands (vpdiinp and vpbpp) in the coordination sphere of [Ru(bdmpmar)(vpdiinp)(H2dcbpy)]2+, [Ru(bdmpmar) (vpbpp)(H2dcbpy)]2+, [Ru(H2dcbpy)2(N^)(NCS)]+, [Ru(H2dcbpy)2(N^)2]2+, [Ru(H2dcbpy)(N^)2(NCS)2], [Ru(H2dcbpy)(N^)(NCS)3]– and [Ru(vptpy)(H2dcbpy)(N^^^)]2+ respectively, all related to series II, III, IV, V, VI, VII and two compounds of series VIII ruthenium(II) complexes, has been studied using the 1H and 13C NMR spectroscopy techniques. The 1H NMR spectra of series II-VII and the two compounds of series VIII of the ruthenium(II) complexes show multiplets in the aromatic region above 6 ppm due to the presence of either vpdiinp or vpbpp ligand, situated in different magnetic environment. However, no splitting pattern was observed in series I and part of VIII complexes possibly due to the absence vinyl monodentate subunits (vpdiinp and vpbpp) in series I and one of compound in series VIII ruthenium(II) complexes show no signals of complex splitting patterns. Carbon-13 NMR spectra data of series I to VIII ruthenium(II) complexes show most resonance signals range in the aromatic region of (δ 116.54-199.63ppm) corresponding to the molecular formulation of ruthenium(II) complexes incorporating 4,4-dicarboxy-2,2’-bipyridine, bdmpmar, vptpy, vpdiinp or vpbpp and NCS ligands respectively, depending on the intrinsic ligand variations. Carbon-13 NMR spectra data of series I, IV, VI VII and one compound in VIII show resonance peaks within the range 130-135 ppm are ascribed to NCS ligand confirming the presence of N-coordinated thiocyanate. Cyclic voltammograms of series I-IV and VI-VIII complexes display ruthenium-based oxidative peaks and the pyridines ligand-based reductive peaks. The redox behavior of complexes 4-12, 14-16, 18-20, 24-26 and 30 is dominated by the Ru(II)/R(III) redox couple in region (E1/2 between 0.53 and 1.18) and the pyridines ligand-based redox couples in the region between (E1/2 between −0.25 and −1.45). The photophysical property studies of the Ru(II) complexes are determined through the acquisitions of the absorption spectra, which tends to have profound effect on the short circuit current of DSSC. The absorption maxima were tuned by the introduction and variation of six (6) tripodal chelating ligands, two (2) vinyl monodentate ligands and one (1) vinyl tridentate ligand. From the studies, the results show that series IV, V, VI, VII and VIII complexes of molecular formula [Ru(H2dcbpy)2(N^)(NCS)]2+, [Ru(H2dcbpy)2(N^)2]2+, [Ru(H2dcbpy)(N^)2(NCS)2]2+, [Ru(H2dcbpy)(N^)(NCS)3]2+ and [Ru(vptpy)(H2dcbpy)(N^^^)]2+ respectively, have higher and multiple local absorption maxima near-IR region than the complexes of series I, II and III of molecular [Ru(bdmpmar)(H2dcbpy)(NCS)]2,+, [Ru(bdmpmar)(vpdiinp)(H2dcbpy)]2,+, [Ru(bdmpmar)(vpbpp)(H2dcbpy)]2,+respectively.
- Full Text:
- Date Issued: 2018
- Authors: Adjogri, Shadrack John
- Date: 2018
- Subjects: Ruthenium Ruthenium compounds
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/17828 , vital:41363
- Description: Eight series of thirty (30) novel heteroleptic ruthenium(II) complexes were designed, synthesized and spectroscopically characterized, with the following general molecular formulae as [Ru(bdmpmar)(H2dcbpy)(NCS)]+, [Ru(bdmpmar)(vpdiinp)(H2dcbpy)]2,+, [Ru(bdmpmar)(vpbpp)(H2dcbpy)]2+,[Ru(H2dcbpy)2(N^)(NCS)]+, [Ru(H2dcbpy)2(N^)2]2+, [Ru(H2dcbpy)(N^)2(NCS)2], [Ru(H2dcbpy)(N^)(NCS)3]– and [Ru(vptpy)(H2dcbpy)(N^^^)]2+ where bdmpmar is a tridentate ligand of N,N-bis(3, 5-dimethylpyrazol-1-yl-methyl) aromatic organic compound (such aromatic organic compounds(Ar) are anthranilic acid, 4-methoxy-2-nitroaniline, aniline, toluidine, cyclohexylamine and anisidine), vpdiinp represents a monodentate ligand of 11-(4-vinylphenyl)diindeno[1,2-b:2’,1’-e]pyridine, vpbpp represents a monodentate ligand of 4-(4-vinylphenyl)-2.6-bis(phenyl)pyridine and vptpy represents a tridentate ligand of 4’-(4-vinyl)-2,2’:6’,2’’-terpyridine. Meanwhile, N^ represents any of the monodentate ligands of either vpdiinp or vpbpp and (N^^^) represents any of the monodentate ligands either of vpdiinp or vpbpp or NCS as disclosed in series VIII. The complexes were characterized by conductivity measurement, solubility, melting point, UV-Vis, PL, FTIR (ATR), NMR, Cyclic and square wave voltammetry. Nine chelating ligands, comprising of six (6) tripodal chelating ligands, two (2) vinyl monodentate ligands and one (1) vinyl tridentate ligand, were used for the synthesis of ruthenium(II) complexes ATR-FTIR spectra of all the ruthenium(II) complexes measured as solid samples, exhibited fine resolution IR bands in region between 3473-3438 cm-1 of carboxylic group in H2dcbpy. The bands in the range 3040-2950 cm-1 were ascribed to C-H bond stretching for the CH3 groups. The coordination of NCS group in the sphere of ruthenium(II) complexes related to series I, IV, VI VII and one compound of series VIII was investigated by ATR-FTIR spectroscopy. Bands in the range of 2116-2106 cm-1 and 777-770 cm-1 are ascribed to the respective N=C and the C=S bond stretching vibration which confirms the N-coordination of the SCN group. For all the complexes, the stretching vibration of Ru-N bonding was between 466 and 411 cm-1 due to coordination of the nitrogen atoms of the ligands to ruthenium central metal atom. The introduction of the two vinyl monodentate ligands (vpdiinp and vpbpp) in the coordination sphere of [Ru(bdmpmar)(vpdiinp)(H2dcbpy)]2+, [Ru(bdmpmar) (vpbpp)(H2dcbpy)]2+, [Ru(H2dcbpy)2(N^)(NCS)]+, [Ru(H2dcbpy)2(N^)2]2+, [Ru(H2dcbpy)(N^)2(NCS)2], [Ru(H2dcbpy)(N^)(NCS)3]– and [Ru(vptpy)(H2dcbpy)(N^^^)]2+ respectively, all related to series II, III, IV, V, VI, VII and two compounds of series VIII ruthenium(II) complexes, has been studied using the 1H and 13C NMR spectroscopy techniques. The 1H NMR spectra of series II-VII and the two compounds of series VIII of the ruthenium(II) complexes show multiplets in the aromatic region above 6 ppm due to the presence of either vpdiinp or vpbpp ligand, situated in different magnetic environment. However, no splitting pattern was observed in series I and part of VIII complexes possibly due to the absence vinyl monodentate subunits (vpdiinp and vpbpp) in series I and one of compound in series VIII ruthenium(II) complexes show no signals of complex splitting patterns. Carbon-13 NMR spectra data of series I to VIII ruthenium(II) complexes show most resonance signals range in the aromatic region of (δ 116.54-199.63ppm) corresponding to the molecular formulation of ruthenium(II) complexes incorporating 4,4-dicarboxy-2,2’-bipyridine, bdmpmar, vptpy, vpdiinp or vpbpp and NCS ligands respectively, depending on the intrinsic ligand variations. Carbon-13 NMR spectra data of series I, IV, VI VII and one compound in VIII show resonance peaks within the range 130-135 ppm are ascribed to NCS ligand confirming the presence of N-coordinated thiocyanate. Cyclic voltammograms of series I-IV and VI-VIII complexes display ruthenium-based oxidative peaks and the pyridines ligand-based reductive peaks. The redox behavior of complexes 4-12, 14-16, 18-20, 24-26 and 30 is dominated by the Ru(II)/R(III) redox couple in region (E1/2 between 0.53 and 1.18) and the pyridines ligand-based redox couples in the region between (E1/2 between −0.25 and −1.45). The photophysical property studies of the Ru(II) complexes are determined through the acquisitions of the absorption spectra, which tends to have profound effect on the short circuit current of DSSC. The absorption maxima were tuned by the introduction and variation of six (6) tripodal chelating ligands, two (2) vinyl monodentate ligands and one (1) vinyl tridentate ligand. From the studies, the results show that series IV, V, VI, VII and VIII complexes of molecular formula [Ru(H2dcbpy)2(N^)(NCS)]2+, [Ru(H2dcbpy)2(N^)2]2+, [Ru(H2dcbpy)(N^)2(NCS)2]2+, [Ru(H2dcbpy)(N^)(NCS)3]2+ and [Ru(vptpy)(H2dcbpy)(N^^^)]2+ respectively, have higher and multiple local absorption maxima near-IR region than the complexes of series I, II and III of molecular [Ru(bdmpmar)(H2dcbpy)(NCS)]2,+, [Ru(bdmpmar)(vpdiinp)(H2dcbpy)]2,+, [Ru(bdmpmar)(vpbpp)(H2dcbpy)]2,+respectively.
- Full Text:
- Date Issued: 2018
Development of InSb/GaSb quantum dots by MOVPE
- Authors: Ahia, Chinedu Christian
- Date: 2018
- Subjects: Semiconductors , Quantum electronics Organometallic compounds
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/23382 , vital:30537
- Description: There has been an increasing interest in the modification of semiconductor band structures through the reduction of their dimensions, which simultaneously increases the band gap energy of the material and gives rise to flexibility in device properties. Advances in III-V antimony (Sb) based semiconductor fabrication have triggered the quest for extension of the emission/absorption wavelength range of this family of compounds for optoelectronic devices operating in the mid-infrared region of the electromagnetic spectrum. An interesting material system for mid-infrared (MIR) applications is indium antimonide (InSb) quantum dots (QDs) within a gallium antimonide (GaSb) matrix. However, its band alignment and emission wavelength has been the subject of some interest and controversy over the years. This study focuses on the development of InSb/GaSb QDs by metal organic vapour phase epitaxy (MOVPE). The samples were grown on different substrates using various growth parameters in order to vary the size, density and aspect ratio of the dots. Interfacial growth interruptions while flowing various source precursors through the reactor were investigated in order to influence the chemical termination of the surface, and hence the resulting strain in the structures. The samples were characterized using photoluminescence spectroscopy, scanning probe microscopy, scanning electron microscopy, X-ray diffraction and transmission electron microscopy. Likewise, the band alignment, energy levels, and carrier wave functions of the samples in this work were modelled theoretically using the nextnanomat software (version 3.1.0.0). A comparison of growth on two different GaSb substrates [(100) 2° off towards <111>B ± 0.1ᵒ and (111) ± 0.1ᵒ] using similar growth conditions yielded a higher dot density on the (100) substrate compared to the (111) substrate. This was attributed to the presence of terraces/atomic steps induced by the misorientation on the (100) substrate, which invariably gives rise to increased adsorption and an enhanced sticking coefficient of adatoms. Studies on the influence of a buffer layer on the morphology of uncapped dots showed that the shape and size of the dots are sensitive to the thickness of the buffer layer. In some case a corrugated buffer surface resulted, which introduced order in the arrangement of the dots, which formed preferentially inside the troughs. An increase in the V/III ratio from 1.0 to 3.0 was found to reduce the areal density of the QDs, while an analysis of the diameter histograms showed a narrowing of the size distribution with an increase in V/III ratio. The larger size distribution at low V/III was ascribed to the increase in indium species and the increased indium adatom migration length. This leads to increased dot density and nucleation sites, and thus triggers an increase in the conversion of tiny QDs into thermodynamically more suitable larger dots via coalescence. However, as the V/III ratio increased, the number of indium adatoms available for growth on the surface reduced, which automatically led to a decrease in the migration length of indium species which is unfavourable for the production of nucleation sites and to a decrease in dot density. Low growth rates were found to be beneficial for the growth of a high density (~5×1010cm-2) of QDs. Photoluminescence (PL) analysis of the capped samples at low temperature (~10 K), using an excitation power of 2 mW, showed a PL peak at ∼732 meV. Upon an increase in laser power to 120 mW, a blue shift of ∼ 8 meV was noticed. This emission typically persisted up to 60–70 K. An increase in the number of InSb QD-layers, was observed to cause an increase in the luminescence spectral line width and a long-wavelength shift of the PL lines, together with an enhancement in the strength of the PL emission. However, high resolution transmission electron microscopy (HRTEM) of the capped dots revealed the formation of an InGaSb quantum well-like structure, ∼10 nm thick, which was responsible for the PL signal mentioned above. The absence of QDs in the capped sample was attributed to inter-diffusion of Ga and In during the deposition of the cap layer, giving rise to a quantum well (QW) instead of the intended QDs. The presence of threading dislocations and stacking faults were also observed in the TEM micrographs of the samples containing multilayers, which can account for the fast quenching of the PL emission with increasing temperature from these samples. Theoretical simulations of the band alignment, wave functions and energy levels were in good agreement with the data collected from the PL spectra of the samples.
- Full Text:
- Date Issued: 2018
- Authors: Ahia, Chinedu Christian
- Date: 2018
- Subjects: Semiconductors , Quantum electronics Organometallic compounds
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/23382 , vital:30537
- Description: There has been an increasing interest in the modification of semiconductor band structures through the reduction of their dimensions, which simultaneously increases the band gap energy of the material and gives rise to flexibility in device properties. Advances in III-V antimony (Sb) based semiconductor fabrication have triggered the quest for extension of the emission/absorption wavelength range of this family of compounds for optoelectronic devices operating in the mid-infrared region of the electromagnetic spectrum. An interesting material system for mid-infrared (MIR) applications is indium antimonide (InSb) quantum dots (QDs) within a gallium antimonide (GaSb) matrix. However, its band alignment and emission wavelength has been the subject of some interest and controversy over the years. This study focuses on the development of InSb/GaSb QDs by metal organic vapour phase epitaxy (MOVPE). The samples were grown on different substrates using various growth parameters in order to vary the size, density and aspect ratio of the dots. Interfacial growth interruptions while flowing various source precursors through the reactor were investigated in order to influence the chemical termination of the surface, and hence the resulting strain in the structures. The samples were characterized using photoluminescence spectroscopy, scanning probe microscopy, scanning electron microscopy, X-ray diffraction and transmission electron microscopy. Likewise, the band alignment, energy levels, and carrier wave functions of the samples in this work were modelled theoretically using the nextnanomat software (version 3.1.0.0). A comparison of growth on two different GaSb substrates [(100) 2° off towards <111>B ± 0.1ᵒ and (111) ± 0.1ᵒ] using similar growth conditions yielded a higher dot density on the (100) substrate compared to the (111) substrate. This was attributed to the presence of terraces/atomic steps induced by the misorientation on the (100) substrate, which invariably gives rise to increased adsorption and an enhanced sticking coefficient of adatoms. Studies on the influence of a buffer layer on the morphology of uncapped dots showed that the shape and size of the dots are sensitive to the thickness of the buffer layer. In some case a corrugated buffer surface resulted, which introduced order in the arrangement of the dots, which formed preferentially inside the troughs. An increase in the V/III ratio from 1.0 to 3.0 was found to reduce the areal density of the QDs, while an analysis of the diameter histograms showed a narrowing of the size distribution with an increase in V/III ratio. The larger size distribution at low V/III was ascribed to the increase in indium species and the increased indium adatom migration length. This leads to increased dot density and nucleation sites, and thus triggers an increase in the conversion of tiny QDs into thermodynamically more suitable larger dots via coalescence. However, as the V/III ratio increased, the number of indium adatoms available for growth on the surface reduced, which automatically led to a decrease in the migration length of indium species which is unfavourable for the production of nucleation sites and to a decrease in dot density. Low growth rates were found to be beneficial for the growth of a high density (~5×1010cm-2) of QDs. Photoluminescence (PL) analysis of the capped samples at low temperature (~10 K), using an excitation power of 2 mW, showed a PL peak at ∼732 meV. Upon an increase in laser power to 120 mW, a blue shift of ∼ 8 meV was noticed. This emission typically persisted up to 60–70 K. An increase in the number of InSb QD-layers, was observed to cause an increase in the luminescence spectral line width and a long-wavelength shift of the PL lines, together with an enhancement in the strength of the PL emission. However, high resolution transmission electron microscopy (HRTEM) of the capped dots revealed the formation of an InGaSb quantum well-like structure, ∼10 nm thick, which was responsible for the PL signal mentioned above. The absence of QDs in the capped sample was attributed to inter-diffusion of Ga and In during the deposition of the cap layer, giving rise to a quantum well (QW) instead of the intended QDs. The presence of threading dislocations and stacking faults were also observed in the TEM micrographs of the samples containing multilayers, which can account for the fast quenching of the PL emission with increasing temperature from these samples. Theoretical simulations of the band alignment, wave functions and energy levels were in good agreement with the data collected from the PL spectra of the samples.
- Full Text:
- Date Issued: 2018
A lean production approach to materials management in the Nigerian construction industry
- Authors: Albert, Idowu
- Date: 2020
- Subjects: Materials management , Lean manufacturing Construction industry -- Nigeria
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/46008 , vital:39408
- Description: The Nigerian Construction Industry faces a problem of poor materials management that leads to, among other things, materials waste, poor quality of work, poor materials flow, project delay and cost overrun. Overcoming these challenges, requires the rethinking the current modus operandi of the Nigerian construction industry. One such method that has been espoused as having potential to improve materials management, and associated challenges is ‘lean production’. This research aimed at deciphering the lean approach to production management with a view of extracting its utility in enhancing materials management in the construction industry. The qualitative method of research inquiry that is rooted in the phenomenological paradigm was employed. The research activities included a comprehensive review of the related literature and study of selected cases. Abuja, the Federal capital territory of Nigeria was the selected geographical scope of the research. Ten case studies were purposefully selected for the study. The research instrument was a tick box used for direct observation. The study revealed that poor materials management has a negative effect on the materials management plan. Moreover, mixing of waste at the site, negates the effort for identification of materials waste streams, and makes it difficult to account for materials waste, as well as implementing a materials waste management policy on sites. The research also found that poor materials management has a significant effect (high, moderate or low) on materials waste, quality of work, materials flow, productivity, project delay, project profitability and accounting for materials. The research has developed a conceptual model for a lean production approach to materials management based on the results and informed by the theoretical framework. The study has achieved its aim of establishing an understanding of the lean production approach to materials management in the Nigerian construction industry. The study recommends that construction professionals should be well informed on the effects of poor materials management.
- Full Text:
- Date Issued: 2020
- Authors: Albert, Idowu
- Date: 2020
- Subjects: Materials management , Lean manufacturing Construction industry -- Nigeria
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/46008 , vital:39408
- Description: The Nigerian Construction Industry faces a problem of poor materials management that leads to, among other things, materials waste, poor quality of work, poor materials flow, project delay and cost overrun. Overcoming these challenges, requires the rethinking the current modus operandi of the Nigerian construction industry. One such method that has been espoused as having potential to improve materials management, and associated challenges is ‘lean production’. This research aimed at deciphering the lean approach to production management with a view of extracting its utility in enhancing materials management in the construction industry. The qualitative method of research inquiry that is rooted in the phenomenological paradigm was employed. The research activities included a comprehensive review of the related literature and study of selected cases. Abuja, the Federal capital territory of Nigeria was the selected geographical scope of the research. Ten case studies were purposefully selected for the study. The research instrument was a tick box used for direct observation. The study revealed that poor materials management has a negative effect on the materials management plan. Moreover, mixing of waste at the site, negates the effort for identification of materials waste streams, and makes it difficult to account for materials waste, as well as implementing a materials waste management policy on sites. The research also found that poor materials management has a significant effect (high, moderate or low) on materials waste, quality of work, materials flow, productivity, project delay, project profitability and accounting for materials. The research has developed a conceptual model for a lean production approach to materials management based on the results and informed by the theoretical framework. The study has achieved its aim of establishing an understanding of the lean production approach to materials management in the Nigerian construction industry. The study recommends that construction professionals should be well informed on the effects of poor materials management.
- Full Text:
- Date Issued: 2020
Commercial maritime higher education needs in South Africa
- Authors: Allison, Lee-Anne
- Date: 2020
- Subjects: Education, Higher -- Curricula , Education, Higher -- Research Merchant marine Shipping -- Economic aspects
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/50350 , vital:42111
- Description: Seaborne cargo trade accounts for over 80% of the physical volume of global trade. Maritime transport thus fulfils an integral function in the economy of the world. South Africa generates approximately 3.5% of the world’s seaborne trade by value and 1.61% by tonnage; but the business of shipping all that cargo is undertaken by foreign firms. Operation Phakisa, the Comprehensive Maritime Transport Policy and the South African Maritime Road Map, in pursuance of the National Development Plan, aim to revive the commercial maritime sector. In order to meet the demand for the skills and innovative abilities sought at executive and managerial levels in the commercial maritime sector, higher education in the knowledge of maritime business is increasingly becoming a prerequisite. Investment in higher education of quality and relevance in the maritime field would contribute to achieving the goals of the government for harnessing the potential of South Africa’s blue economy. The literature is researched in order to establish an authoritative view that the knowledge and the inspiration for entrepreneurial activity in the maritime sector can be imparted through higher education; and for example, that a viable shipping sector can contribute to the growth of a country’s economy. The South African maritime sector is then described. The commercial maritime higher education available at universities and other institutions of higher learning in South Africa, as well as in other African countries and elsewhere in the world, is examined, in order to be able to identify the degree and diploma courses available. Maritime courses imply not only the content of the educational material, but also the method whereby the knowledge is instilled in learners, and which extends well beyond the classroom. A survey, by way of the personal interviews of leaders in maritime business, maritime government affairs, and academics teaching maritime topics, is then undertaken to ascertain their views on the education required to promote the maritime sector in South Africa, using the list of subjects available for study worldwide, to assist their choice. The literature research and the interview survey by design also enable the secondary aims of the study to be achieved. Those aims include determining how awareness of the maritime domain could be raised and how co-operation between academia, business and government, known as the triple helix could be organised, to promote the growth of the maritime sector. The results of the survey are analysed and tabulated, in order to illustrate the extent of the agreement between those interviewed and the conclusions reached. These conclusions establish: that the commercial maritime education currently available in South Africa, is inadequate to meet the aim of the government to the sector; that a post-graduate degree in the specified maritime studies incorporating a period of internship, and following on a first degree in business subjects, is required; that a triple helix of co-operation between academia, business and the government is essential to grow the commercial maritime sector in which South African entrepreneurs educated in such business will have the advantage; that greater awareness of the maritime domain is essential in South Africa if entrepreneurship in maritime business is to be cultivated; and that such awareness can be cultivated in various ways; but it should start by including more maritime topics in the current school curricula.
- Full Text:
- Date Issued: 2020
- Authors: Allison, Lee-Anne
- Date: 2020
- Subjects: Education, Higher -- Curricula , Education, Higher -- Research Merchant marine Shipping -- Economic aspects
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/50350 , vital:42111
- Description: Seaborne cargo trade accounts for over 80% of the physical volume of global trade. Maritime transport thus fulfils an integral function in the economy of the world. South Africa generates approximately 3.5% of the world’s seaborne trade by value and 1.61% by tonnage; but the business of shipping all that cargo is undertaken by foreign firms. Operation Phakisa, the Comprehensive Maritime Transport Policy and the South African Maritime Road Map, in pursuance of the National Development Plan, aim to revive the commercial maritime sector. In order to meet the demand for the skills and innovative abilities sought at executive and managerial levels in the commercial maritime sector, higher education in the knowledge of maritime business is increasingly becoming a prerequisite. Investment in higher education of quality and relevance in the maritime field would contribute to achieving the goals of the government for harnessing the potential of South Africa’s blue economy. The literature is researched in order to establish an authoritative view that the knowledge and the inspiration for entrepreneurial activity in the maritime sector can be imparted through higher education; and for example, that a viable shipping sector can contribute to the growth of a country’s economy. The South African maritime sector is then described. The commercial maritime higher education available at universities and other institutions of higher learning in South Africa, as well as in other African countries and elsewhere in the world, is examined, in order to be able to identify the degree and diploma courses available. Maritime courses imply not only the content of the educational material, but also the method whereby the knowledge is instilled in learners, and which extends well beyond the classroom. A survey, by way of the personal interviews of leaders in maritime business, maritime government affairs, and academics teaching maritime topics, is then undertaken to ascertain their views on the education required to promote the maritime sector in South Africa, using the list of subjects available for study worldwide, to assist their choice. The literature research and the interview survey by design also enable the secondary aims of the study to be achieved. Those aims include determining how awareness of the maritime domain could be raised and how co-operation between academia, business and government, known as the triple helix could be organised, to promote the growth of the maritime sector. The results of the survey are analysed and tabulated, in order to illustrate the extent of the agreement between those interviewed and the conclusions reached. These conclusions establish: that the commercial maritime education currently available in South Africa, is inadequate to meet the aim of the government to the sector; that a post-graduate degree in the specified maritime studies incorporating a period of internship, and following on a first degree in business subjects, is required; that a triple helix of co-operation between academia, business and the government is essential to grow the commercial maritime sector in which South African entrepreneurs educated in such business will have the advantage; that greater awareness of the maritime domain is essential in South Africa if entrepreneurship in maritime business is to be cultivated; and that such awareness can be cultivated in various ways; but it should start by including more maritime topics in the current school curricula.
- Full Text:
- Date Issued: 2020
Construction material logistics management: the case of north-central Nigeria
- Authors: Alumbugu, Polycarp Olaku
- Date: 2019
- Subjects: Construction projects-- Nigeria --Management Construction projects --Management Logistics-- Nigeria -- Management , Construction industry -- Nigeria
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/44879 , vital:38179
- 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. Studies have revealed that the cost of construction materials is usually about 50%-60% of the total cost of the project and that the logistic cost accounts for between 17%-35% of the cost material. 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 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 projects-- Nigeria --Management Construction projects --Management Logistics-- Nigeria -- Management , Construction industry -- Nigeria
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/44879 , vital:38179
- 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. Studies have revealed that the cost of construction materials is usually about 50%-60% of the total cost of the project and that the logistic cost accounts for between 17%-35% of the cost material. 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 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
Towards theorizing human resource development in South Africa: a critical analysis and the development of a tool to facilitate improved understanding and practice
- Authors: Anderson, Amber Cristal
- Date: 2006
- Subjects: Manpower planning -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:16130 , http://hdl.handle.net/10948/469 , Manpower planning -- South Africa
- Description: The primary objective of this study is to generate pathways to understanding Human Resources Development (HRD) by developing a tool which enables and enhances a shared and common understanding of HRD in South Africa (SA). To achieve this objective, this research explores the nature and importance of HRD and articulates and aggregates these thoughts and practices into a tool which facilitates an understanding of HRD with the overarching aim of improving HRD thoughts and practices in South Africa. While there is substantial international and local literature on HRD, the existing body of research on the nature and importance of HRD in South Africa is skeletal. National HRD concepts and practices are fragmented, and are as diverse as the number of stakeholders and partners that it serves. In addition, theory-building in HRD is disconnected and removed from practice. In order to address this problem, a qualitative, interpretive, theory-building social constructionist research strategy was embarked upon. The research strategy was executed in an iterative, cyclical manner, using theoretical sampling and content analysis rigorously executed within a coding paradigm informed by open, axial and selective coding techniques with local and international literature and informal reviews as the units of analysis. Qualitative and quantitative findings of the South African Qualifications Authority ground-breaking, world-first longitudinal study was analyzed and used to find relevance and corroborate the international literature available on HRD. Informal reviews were conducted with 7 human resources (HR) practitioners and 54 internationally-based HR colleagues of the researcher in order to ensure as appropriate a degree of integration between theory and practice as was possible. This process culminated in the most significant contribution of this research, which is a tool consisting of six pathways, that facilitates an understanding of the nature and importance of HRD in South Africa. The development of the tool enabled the articulation and aggregation of a thorough and coherent description, explanation and representation of HRD. The research highlights the need for HRD scholars and practitioners to channel their energies and effort on all the catalytic aspects of organizational life, namely uniqueness, social complexity, knowledge, and path dependency, by acquiring critical insight into the profound value of HRD which will allow the realization and sustainability of competitive advantage in a rich and dynamic global economy.
- Full Text:
- Date Issued: 2006
- Authors: Anderson, Amber Cristal
- Date: 2006
- Subjects: Manpower planning -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:16130 , http://hdl.handle.net/10948/469 , Manpower planning -- South Africa
- Description: The primary objective of this study is to generate pathways to understanding Human Resources Development (HRD) by developing a tool which enables and enhances a shared and common understanding of HRD in South Africa (SA). To achieve this objective, this research explores the nature and importance of HRD and articulates and aggregates these thoughts and practices into a tool which facilitates an understanding of HRD with the overarching aim of improving HRD thoughts and practices in South Africa. While there is substantial international and local literature on HRD, the existing body of research on the nature and importance of HRD in South Africa is skeletal. National HRD concepts and practices are fragmented, and are as diverse as the number of stakeholders and partners that it serves. In addition, theory-building in HRD is disconnected and removed from practice. In order to address this problem, a qualitative, interpretive, theory-building social constructionist research strategy was embarked upon. The research strategy was executed in an iterative, cyclical manner, using theoretical sampling and content analysis rigorously executed within a coding paradigm informed by open, axial and selective coding techniques with local and international literature and informal reviews as the units of analysis. Qualitative and quantitative findings of the South African Qualifications Authority ground-breaking, world-first longitudinal study was analyzed and used to find relevance and corroborate the international literature available on HRD. Informal reviews were conducted with 7 human resources (HR) practitioners and 54 internationally-based HR colleagues of the researcher in order to ensure as appropriate a degree of integration between theory and practice as was possible. This process culminated in the most significant contribution of this research, which is a tool consisting of six pathways, that facilitates an understanding of the nature and importance of HRD in South Africa. The development of the tool enabled the articulation and aggregation of a thorough and coherent description, explanation and representation of HRD. The research highlights the need for HRD scholars and practitioners to channel their energies and effort on all the catalytic aspects of organizational life, namely uniqueness, social complexity, knowledge, and path dependency, by acquiring critical insight into the profound value of HRD which will allow the realization and sustainability of competitive advantage in a rich and dynamic global economy.
- Full Text:
- Date Issued: 2006
The role of family structure and financial socialisation in influencing students' financial capabilities
- Authors: Antoni, Xolile Lucas
- Date: 2018
- Subjects: Finance, Personal , Families -- Economic aspects Finance -- Social aspects
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/21505 , vital:29531
- Description: This research used three theories to develop a theoretical framework that investigated the role of family structures and financial socialisation in influencing students’ levels of financial knowledge, attitudes, self-efficacy and behaviour (financial capabilities). It also examined the mediating role of family financial situation in the relationship between the family structure and the mechanisms of financial socialisation. The theories of consumer socialisation, family financial socialisation and family structure model, guided the development of a proposed theoretical framework and development of five major hypotheses. To answer the research questions of the study and test the hypotheses, this study followed a quantitative survey research design. Undergraduate students in the Faculty of Business and Economic Sciences completed 350 questionnaires. Using exploratory factor analyses results, the theoretical framework was updated, and statistical relationships tested. Simple regression analysis results showed that students who were born or raised in an intact family structure reported more financial socialisation in terms of the mechanisms of financial socialisation than students who were born or raised in non-intact family structures. Simple regression results showed that intact family structures had positive significant relationships with four of the six components of the mechanisms of financial socialisation. Furthermore, intact family structures had negative significant relationships with two components of the mechanisms of financial socialisation. Multiple regression results showed four components of the mechanisms of financial socialisation (teaching and monitoring, reinforcement of financial behaviour, modelling of financial behaviour and financial conflict) had positive significant relationships with financial capabilities. The components of financial socialisation agents (peers and media) had positive significant relationships with three components of financial capabilities (financial behaviour, money is respect and freedom, and money is good). In addition, family financial situation partially mediated the relationship between intact family structure and three components of the mechanisms of financial socialisation, namely, parental teaching and monitoring, modelling of financial behaviour and parental relationship. Furthermore, family financial situation perfectly mediated the relationship between intact family structures and one component of the mechanisms of financial socialisation (reinforcement of financial behaviour). Three components of the mechanisms of financial socialisation (parental teaching and monitoring, reinforcement of financial behaviour and modelling of financial behaviour) also perfectly mediated the relationship between intact family structure and one component of financial capabilities, namely, financial behaviour. Similarly, one component of the mechanisms of financial socialisation (parental teaching and monitoring) also perfectly mediated the relationship between intact family structure and one component of financial capabilities (financial self-efficacy). These results assisted in the development of a new empirically tested model to investigate the role of family structure and financial socialisation in influencing students’ financial capabilities. This study showed that family structures was an important variable that should not be excluded in financial planning as it influenced all the components of the mechanisms of financial socialisation. Financial socialisation agents also had an influence on financial capabilities and, thus, the parental financial socialisation should not be investigated in isolation. It was also important to identify the mechanisms of financial socialisation as seen in this study, as the components of the mechanisms had different influences on students’ financial capabilities. For this study, parental teaching and monitoring, reinforcement of financial behaviour and modelling of financial behaviour proved to be the most important components of the mechanisms of financial socialisation, which ultimately influenced students’ financial capabilities. This study has proved that family structures and financial socialisation influence the financial capabilities of students. To improve financial capabilities of students, parents should increase their level of modelling of financial behaviour and decrease the level of secrecy about money in the household. Parents should also instill positive financial attitudes in students, monitor their financial behaviour, and reinforce positive financial behaviour. This study contributes to the much-needed body of knowledge in financial planning by showing through empirical results that family structure has an influence on the components of the factor mechanisms of financial socialisation, and the factor financial capabilities. As little information exists to explain these relationships, this study makes a valuable contribution to new knowledge in this area.
- Full Text:
- Date Issued: 2018
- Authors: Antoni, Xolile Lucas
- Date: 2018
- Subjects: Finance, Personal , Families -- Economic aspects Finance -- Social aspects
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/21505 , vital:29531
- Description: This research used three theories to develop a theoretical framework that investigated the role of family structures and financial socialisation in influencing students’ levels of financial knowledge, attitudes, self-efficacy and behaviour (financial capabilities). It also examined the mediating role of family financial situation in the relationship between the family structure and the mechanisms of financial socialisation. The theories of consumer socialisation, family financial socialisation and family structure model, guided the development of a proposed theoretical framework and development of five major hypotheses. To answer the research questions of the study and test the hypotheses, this study followed a quantitative survey research design. Undergraduate students in the Faculty of Business and Economic Sciences completed 350 questionnaires. Using exploratory factor analyses results, the theoretical framework was updated, and statistical relationships tested. Simple regression analysis results showed that students who were born or raised in an intact family structure reported more financial socialisation in terms of the mechanisms of financial socialisation than students who were born or raised in non-intact family structures. Simple regression results showed that intact family structures had positive significant relationships with four of the six components of the mechanisms of financial socialisation. Furthermore, intact family structures had negative significant relationships with two components of the mechanisms of financial socialisation. Multiple regression results showed four components of the mechanisms of financial socialisation (teaching and monitoring, reinforcement of financial behaviour, modelling of financial behaviour and financial conflict) had positive significant relationships with financial capabilities. The components of financial socialisation agents (peers and media) had positive significant relationships with three components of financial capabilities (financial behaviour, money is respect and freedom, and money is good). In addition, family financial situation partially mediated the relationship between intact family structure and three components of the mechanisms of financial socialisation, namely, parental teaching and monitoring, modelling of financial behaviour and parental relationship. Furthermore, family financial situation perfectly mediated the relationship between intact family structures and one component of the mechanisms of financial socialisation (reinforcement of financial behaviour). Three components of the mechanisms of financial socialisation (parental teaching and monitoring, reinforcement of financial behaviour and modelling of financial behaviour) also perfectly mediated the relationship between intact family structure and one component of financial capabilities, namely, financial behaviour. Similarly, one component of the mechanisms of financial socialisation (parental teaching and monitoring) also perfectly mediated the relationship between intact family structure and one component of financial capabilities (financial self-efficacy). These results assisted in the development of a new empirically tested model to investigate the role of family structure and financial socialisation in influencing students’ financial capabilities. This study showed that family structures was an important variable that should not be excluded in financial planning as it influenced all the components of the mechanisms of financial socialisation. Financial socialisation agents also had an influence on financial capabilities and, thus, the parental financial socialisation should not be investigated in isolation. It was also important to identify the mechanisms of financial socialisation as seen in this study, as the components of the mechanisms had different influences on students’ financial capabilities. For this study, parental teaching and monitoring, reinforcement of financial behaviour and modelling of financial behaviour proved to be the most important components of the mechanisms of financial socialisation, which ultimately influenced students’ financial capabilities. This study has proved that family structures and financial socialisation influence the financial capabilities of students. To improve financial capabilities of students, parents should increase their level of modelling of financial behaviour and decrease the level of secrecy about money in the household. Parents should also instill positive financial attitudes in students, monitor their financial behaviour, and reinforce positive financial behaviour. This study contributes to the much-needed body of knowledge in financial planning by showing through empirical results that family structure has an influence on the components of the factor mechanisms of financial socialisation, and the factor financial capabilities. As little information exists to explain these relationships, this study makes a valuable contribution to new knowledge in this area.
- Full Text:
- Date Issued: 2018
Effective and efficient performance management in local government, with reference to the Cacadu District Municipality
- Authors: Asmah-Andoh, Kwame
- Date: 2012
- Subjects: Performance -- Management , Performance standards -- South Africa -- Eastern Cape , Municipal government -- South Africa -- Eastern Cape , Employees -- Rating of -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:8161 , http://hdl.handle.net/10948/1633 , Performance -- Management , Performance standards -- South Africa -- Eastern Cape , Municipal government -- South Africa -- Eastern Cape , Employees -- Rating of -- South Africa
- Description: This study examined the existing levels of effectiveness and efficiency in local government with the application of performance management systems in the provision of municipal services. The provision of district-wide water services in Cacadu District Municipality in the Province of the Eastern Cape, South Africa is used for particular reference. Local government reforms after 1994 led to the creation of the district municipality (which groups together a number of local municipalities) to drive district-wide services provision, the introduction of systematic services provision standards and performance management as part of management reforms in municipalities. The problem for the research deals with how the Cacadu District Council and the councils of the local municipalities within the district are collaborating in using performance management systems, what effects this could have on programmes and services provision and how communication of performance information would improve service provision. Conceptual and practical difficulties encountered in effective and efficient utilisation and some obstacles that contribute to impeding progress in the use of performance management systems in municipalities were analysed. The qualitative research included a review of documents from the public administration and management literature; discourse analysis of interviews with municipal councilors and appointed officials, community members and provincial managers. The document review included a review of municipal documents that incorporated performance management or described development and use of performance management systems. It also included the legal frameworks and statutory requirements for municipal government and administration. All the responding municipal councils within the Cacadu District Municipality reported using performance management over the past five years yet little empirical evidence explains usage for district-wide programmes and services provision. Research shows that a comprehensive performance management approach to programmes and services has a more effective and efficient impact on service improvement than utilisation of personnnel appraisal (Ammons and Rivenbark, 2005). Despite the expected benefits, personnel performance appraisal is often flawed and the need exists in the district municipal model to develop and utilise performance management systems that validly assess the work performance of personnel (Hindo, 2010). Performance management system utilisation in decision making management is more related to the long-term benefits of effectiveness and efficiency than personnel appraisal for performance rewards and reporting. To overcome and address a situation of managing performance without a performance management system the study proposes a programme performance measurement and management system which incorporates information on management inputs, programme-specific data and citizens' feedback for outcomes and impact of the service. The suggested design for district-wide and specific municipal services provision elicit and provide relevant and appropriate performance information for management, decision-making and accountability to community. The effectiveness of the proposed system is to provide information for decision-making, long-term planning, strategic management and accountability reporting. The proposal is built on the exisiting method and thus efficient in the utilisation of resources. This has implications both for the theory of Public Administration and Management and the practical application of performamce management in public institutions. The study explicity provides a Public Administration perspective on management in a multi-municipal district context with different authorities. The study contributes to the theory of administrative policy and management context of the municipality with special attention to functions for which different authorities are responsible and the role of a performance system for better insught into managing overlapping authority, gaps and duplications. A central purpose of public management research is to theorise and influence practice. The practical utilisation of the proposed method is intended to assist managers and politicians with better understanding of a sustainable performance management system.
- Full Text:
- Date Issued: 2012
- Authors: Asmah-Andoh, Kwame
- Date: 2012
- Subjects: Performance -- Management , Performance standards -- South Africa -- Eastern Cape , Municipal government -- South Africa -- Eastern Cape , Employees -- Rating of -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:8161 , http://hdl.handle.net/10948/1633 , Performance -- Management , Performance standards -- South Africa -- Eastern Cape , Municipal government -- South Africa -- Eastern Cape , Employees -- Rating of -- South Africa
- Description: This study examined the existing levels of effectiveness and efficiency in local government with the application of performance management systems in the provision of municipal services. The provision of district-wide water services in Cacadu District Municipality in the Province of the Eastern Cape, South Africa is used for particular reference. Local government reforms after 1994 led to the creation of the district municipality (which groups together a number of local municipalities) to drive district-wide services provision, the introduction of systematic services provision standards and performance management as part of management reforms in municipalities. The problem for the research deals with how the Cacadu District Council and the councils of the local municipalities within the district are collaborating in using performance management systems, what effects this could have on programmes and services provision and how communication of performance information would improve service provision. Conceptual and practical difficulties encountered in effective and efficient utilisation and some obstacles that contribute to impeding progress in the use of performance management systems in municipalities were analysed. The qualitative research included a review of documents from the public administration and management literature; discourse analysis of interviews with municipal councilors and appointed officials, community members and provincial managers. The document review included a review of municipal documents that incorporated performance management or described development and use of performance management systems. It also included the legal frameworks and statutory requirements for municipal government and administration. All the responding municipal councils within the Cacadu District Municipality reported using performance management over the past five years yet little empirical evidence explains usage for district-wide programmes and services provision. Research shows that a comprehensive performance management approach to programmes and services has a more effective and efficient impact on service improvement than utilisation of personnnel appraisal (Ammons and Rivenbark, 2005). Despite the expected benefits, personnel performance appraisal is often flawed and the need exists in the district municipal model to develop and utilise performance management systems that validly assess the work performance of personnel (Hindo, 2010). Performance management system utilisation in decision making management is more related to the long-term benefits of effectiveness and efficiency than personnel appraisal for performance rewards and reporting. To overcome and address a situation of managing performance without a performance management system the study proposes a programme performance measurement and management system which incorporates information on management inputs, programme-specific data and citizens' feedback for outcomes and impact of the service. The suggested design for district-wide and specific municipal services provision elicit and provide relevant and appropriate performance information for management, decision-making and accountability to community. The effectiveness of the proposed system is to provide information for decision-making, long-term planning, strategic management and accountability reporting. The proposal is built on the exisiting method and thus efficient in the utilisation of resources. This has implications both for the theory of Public Administration and Management and the practical application of performamce management in public institutions. The study explicity provides a Public Administration perspective on management in a multi-municipal district context with different authorities. The study contributes to the theory of administrative policy and management context of the municipality with special attention to functions for which different authorities are responsible and the role of a performance system for better insught into managing overlapping authority, gaps and duplications. A central purpose of public management research is to theorise and influence practice. The practical utilisation of the proposed method is intended to assist managers and politicians with better understanding of a sustainable performance management system.
- Full Text:
- Date Issued: 2012
A value-based approach to promoting excellence in mathematics education
- Authors: Austin, Pamela Winifred
- Date: 2010
- Subjects: Mathematics -- Study and teaching -- South Africa , Inquiry-based learning -- South Africa , Active learning -- South Africa , Effective teaching -- South Africa , Self-efficacy
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:9482 , http://hdl.handle.net/10948/1656 , Mathematics -- Study and teaching -- South Africa , Inquiry-based learning -- South Africa , Active learning -- South Africa , Effective teaching -- South Africa , Self-efficacy
- Description: This research study has emerged as a result of my concern regarding the apparent low self-efficacy amongst initial teacher education students in my mathematics education classes. It also reflects a reported renewed interest in values, and the promotion of excellence in education. The effects of a values-based approach to mathematics education towards improving students’ self-efficacy and promoting excellence have been investigated, grounded within my ontology of excellence in mathematics education, which incorporates the values of respect, fairness, accountability, honesty and compassion. An inquiry-based teaching and learning approach formed the framework within which the study took place. Notions of ‘new scholarship’, premised on the view that teaching is about engagement in participatory learning, and the development of communities of creative students, provided the theoretical framework. Both quantitative and qualitative data gathering methods were used. Data-collection tools included affective-disposition statements, interviews, journal entries, as well as a video recording of a mathematics education lesson. The quantitative and qualitative data generated suggest improved levels of self-efficacy amongst the students who participated in the study. The data also suggest that a valuesbased approach to teaching can be used as an effective approach by mathematics teachers – and mathematics teacher educators – for the purpose of promoting the pursuit of excellence. As teacher education worldwide is currently characterised by a lack of vitality in teacher preparation (Grossman, 2008), the findings of this study should provide insights for teacher educators, teachers and policy makers who wish to promote mathematics self-efficacy, excellence and facilitate enhanced vitality within the teaching profession.
- Full Text:
- Date Issued: 2010
- Authors: Austin, Pamela Winifred
- Date: 2010
- Subjects: Mathematics -- Study and teaching -- South Africa , Inquiry-based learning -- South Africa , Active learning -- South Africa , Effective teaching -- South Africa , Self-efficacy
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:9482 , http://hdl.handle.net/10948/1656 , Mathematics -- Study and teaching -- South Africa , Inquiry-based learning -- South Africa , Active learning -- South Africa , Effective teaching -- South Africa , Self-efficacy
- Description: This research study has emerged as a result of my concern regarding the apparent low self-efficacy amongst initial teacher education students in my mathematics education classes. It also reflects a reported renewed interest in values, and the promotion of excellence in education. The effects of a values-based approach to mathematics education towards improving students’ self-efficacy and promoting excellence have been investigated, grounded within my ontology of excellence in mathematics education, which incorporates the values of respect, fairness, accountability, honesty and compassion. An inquiry-based teaching and learning approach formed the framework within which the study took place. Notions of ‘new scholarship’, premised on the view that teaching is about engagement in participatory learning, and the development of communities of creative students, provided the theoretical framework. Both quantitative and qualitative data gathering methods were used. Data-collection tools included affective-disposition statements, interviews, journal entries, as well as a video recording of a mathematics education lesson. The quantitative and qualitative data generated suggest improved levels of self-efficacy amongst the students who participated in the study. The data also suggest that a valuesbased approach to teaching can be used as an effective approach by mathematics teachers – and mathematics teacher educators – for the purpose of promoting the pursuit of excellence. As teacher education worldwide is currently characterised by a lack of vitality in teacher preparation (Grossman, 2008), the findings of this study should provide insights for teacher educators, teachers and policy makers who wish to promote mathematics self-efficacy, excellence and facilitate enhanced vitality within the teaching profession.
- Full Text:
- Date Issued: 2010
Influence of the macro-economic environment on the construction sector's contribution to the South African economy, 1984 to 2011
- Authors: Babalola, Adewumi Joseph
- Date: 2016
- Subjects: Construction industry -- Economic aspects Economic development Environmental economics
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/5618 , vital:20916
- Description: The construction sector serves as the engine of growth to the South Africa economy because of its catalytic role in the growth and development of the country. This study focuses mainly on the influence of the macro-economic environment on the contribution of the private sector to construction in the South Africa economy from 1984 to 2011. Government construction work is considered to be an injection into the economy; in this regard, state construction is regarded as public investment in the economy; and therefore, it is anti-cyclic (Keynes, 1936). The aim of this study has been to develop an econometric model for predicting the influence of the macroeconomic environment on the contribution of the private sector to the construction sector in the South Africa economy. The research design adopted in this study was an “ex-post facto” type, otherwise known as a causal-comparative design. The data were extracted from the published sources of the South African National Statistics, namely SARB, Stats SA and Quantec SA. The estimation technique used in this study was the ARDL model using quarterly data from 1984 to 2011. This is because in the construction sector, the influence of the independent variables is always felt over time – rather than all at once. The results of this study show that there is a long run causal relationship between inflation rate, interest rate, real exchange rate, GDP and gdp in the construction sector. The descriptive statistical analysis shows that there is a negative relationship between variables inflation rate and interest rate and the private sector spending in construction. However, economic growth as well as growth in the construction sector has a positive relationship with the private sector spending in construction. Likewise, the real exchange rate and labour productivity in construction have a negative relationship with the private sector’s spending in construction and they are statistically insignificant. The variance decomposition analysis show that the private sector spending in construction explains about 75 per cent of it variations, followed by inflation rate that explains 21 per cent on the average; while the remaining variations, comprising about 4 per cent, were shared among the other independent variables, such as GDP, GDP in construction, the interest rate and the real exchange rate. It was discovered that only the inflation rate does Granger-cause the private sector spending in construction. From the finding it can be concluded that inflation rate is a significant explanatory variable in explaining the variation in the dependent variable during period under review. Policy recommendations are as follows: firstly, the monetary authorities in South Africa should embark on sound policies that would bring about low prices of the construction materials. This would ensure growth and development in the construction sector; secondly, a stimulating development plan that would encourage private sector investment in properties and infrastructural development must be instituted; thirdly, an alternative policy to the present inflation targeting is recommended that would bring about low inflation, high growth, low unemployment and stable exchange rate; fourthly, the present policy on interest rate must be reviewed to allow for more participation in construction projects by the private sectors of the economy; fifthly, due to the fact that fluctuation in the crude oil prices in the international market is one of the major factors causing high inflation rate in South Africa, government must source local alternative products that would bring down prices of construction materials.
- Full Text:
- Date Issued: 2016
- Authors: Babalola, Adewumi Joseph
- Date: 2016
- Subjects: Construction industry -- Economic aspects Economic development Environmental economics
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/5618 , vital:20916
- Description: The construction sector serves as the engine of growth to the South Africa economy because of its catalytic role in the growth and development of the country. This study focuses mainly on the influence of the macro-economic environment on the contribution of the private sector to construction in the South Africa economy from 1984 to 2011. Government construction work is considered to be an injection into the economy; in this regard, state construction is regarded as public investment in the economy; and therefore, it is anti-cyclic (Keynes, 1936). The aim of this study has been to develop an econometric model for predicting the influence of the macroeconomic environment on the contribution of the private sector to the construction sector in the South Africa economy. The research design adopted in this study was an “ex-post facto” type, otherwise known as a causal-comparative design. The data were extracted from the published sources of the South African National Statistics, namely SARB, Stats SA and Quantec SA. The estimation technique used in this study was the ARDL model using quarterly data from 1984 to 2011. This is because in the construction sector, the influence of the independent variables is always felt over time – rather than all at once. The results of this study show that there is a long run causal relationship between inflation rate, interest rate, real exchange rate, GDP and gdp in the construction sector. The descriptive statistical analysis shows that there is a negative relationship between variables inflation rate and interest rate and the private sector spending in construction. However, economic growth as well as growth in the construction sector has a positive relationship with the private sector spending in construction. Likewise, the real exchange rate and labour productivity in construction have a negative relationship with the private sector’s spending in construction and they are statistically insignificant. The variance decomposition analysis show that the private sector spending in construction explains about 75 per cent of it variations, followed by inflation rate that explains 21 per cent on the average; while the remaining variations, comprising about 4 per cent, were shared among the other independent variables, such as GDP, GDP in construction, the interest rate and the real exchange rate. It was discovered that only the inflation rate does Granger-cause the private sector spending in construction. From the finding it can be concluded that inflation rate is a significant explanatory variable in explaining the variation in the dependent variable during period under review. Policy recommendations are as follows: firstly, the monetary authorities in South Africa should embark on sound policies that would bring about low prices of the construction materials. This would ensure growth and development in the construction sector; secondly, a stimulating development plan that would encourage private sector investment in properties and infrastructural development must be instituted; thirdly, an alternative policy to the present inflation targeting is recommended that would bring about low inflation, high growth, low unemployment and stable exchange rate; fourthly, the present policy on interest rate must be reviewed to allow for more participation in construction projects by the private sectors of the economy; fifthly, due to the fact that fluctuation in the crude oil prices in the international market is one of the major factors causing high inflation rate in South Africa, government must source local alternative products that would bring down prices of construction materials.
- Full Text:
- Date Issued: 2016
Political education as a determinant of university students’ political participation in the Eastern Cape, South Africa
- Authors: Badaru, Kazeem Ajasa
- Date: 2019
- Subjects: Citizenship -- Study and teaching -- South Africa Democracy and education -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/15793 , vital:40524
- Description: Globally, there is a downward trend in youths’ political interest and participation in the learning of political education in their school curricula as a measure to combat the apparent dangers posed by the declining young citizens’ participation in the political processes.This study therefore investigated political education as a determinant of university students’ political participation in the Province of the Eastern Cape, South Africa. The study employed a mixed methods design. Using the probability sampling technique, a sample of 375 participants was randomly selected from one university in the Eastern Cape Province while semi-structured interviews were conducted among five (5) purposively selected members of the same university’s Student Representative Council (SRC) executive committee. Simple descriptive statistics such as frequency counts and percentages were used to summarize all categories of variables; while Pearson correlation statistics, Chi-square and Ordinary least square regression were used to examine the relationship between dependent and independent variables at a 95percent confidence interval. Alpha values less than 0.05 were considered to be statistically significant. Thematic content analysis was performed on the qualitative data. The quantitative analysis revealed that students’ level of political awareness was high; 98.1percent of them were aware of their rights to vote and be voted for. Students’ political judgment was positively correlated with participation in campus (r =0.182) and national politics (r = 0.030) respectively. Most of the students agreed to take part in the 2018 SRC (78.8percent) and 2019 national elections (77.9percent) respectively. Political interest was significantly correlated with participation in campus (r = 0.375) and national politics (r =0. 404). The findings from the multivariate analysis showed that political interest (<0.001), parents’ political involvement (<0.001) and year of study (<0.001) were the significant determinants of students’ participation in politics. The qualitative findings also showed that there was a positive relationship between political education and students’ participation in politics. Since political interest and family are element and agent of political education respectively, it is concluded that political education is to a large extent a determinant of university students’ political participation. It is recommended that the universities, the Department of Higher Education and Training (DHET) and other stakeholders should do a thorough review of the university education curricula and programmes to ensure that political education is adequately accommodated and taken care of in a way that would increase students’ interest, awareness and participation in politics. When this is amply done, students’ cognitive skills and capacities would be enhanced to increase their participation in the political processes in South Africa.
- Full Text:
- Date Issued: 2019
- Authors: Badaru, Kazeem Ajasa
- Date: 2019
- Subjects: Citizenship -- Study and teaching -- South Africa Democracy and education -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/15793 , vital:40524
- Description: Globally, there is a downward trend in youths’ political interest and participation in the learning of political education in their school curricula as a measure to combat the apparent dangers posed by the declining young citizens’ participation in the political processes.This study therefore investigated political education as a determinant of university students’ political participation in the Province of the Eastern Cape, South Africa. The study employed a mixed methods design. Using the probability sampling technique, a sample of 375 participants was randomly selected from one university in the Eastern Cape Province while semi-structured interviews were conducted among five (5) purposively selected members of the same university’s Student Representative Council (SRC) executive committee. Simple descriptive statistics such as frequency counts and percentages were used to summarize all categories of variables; while Pearson correlation statistics, Chi-square and Ordinary least square regression were used to examine the relationship between dependent and independent variables at a 95percent confidence interval. Alpha values less than 0.05 were considered to be statistically significant. Thematic content analysis was performed on the qualitative data. The quantitative analysis revealed that students’ level of political awareness was high; 98.1percent of them were aware of their rights to vote and be voted for. Students’ political judgment was positively correlated with participation in campus (r =0.182) and national politics (r = 0.030) respectively. Most of the students agreed to take part in the 2018 SRC (78.8percent) and 2019 national elections (77.9percent) respectively. Political interest was significantly correlated with participation in campus (r = 0.375) and national politics (r =0. 404). The findings from the multivariate analysis showed that political interest (<0.001), parents’ political involvement (<0.001) and year of study (<0.001) were the significant determinants of students’ participation in politics. The qualitative findings also showed that there was a positive relationship between political education and students’ participation in politics. Since political interest and family are element and agent of political education respectively, it is concluded that political education is to a large extent a determinant of university students’ political participation. It is recommended that the universities, the Department of Higher Education and Training (DHET) and other stakeholders should do a thorough review of the university education curricula and programmes to ensure that political education is adequately accommodated and taken care of in a way that would increase students’ interest, awareness and participation in politics. When this is amply done, students’ cognitive skills and capacities would be enhanced to increase their participation in the political processes in South Africa.
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- Date Issued: 2019