Contributions to the study of a class of optimal control problems on the orthogonal groups SO(3) and SO(4)
- Authors: Adams, Ross Montague
- Date: 2015
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/64826 , vital:28608
- Description: In this thesis we investigate a class of invariant optimal control problems, and their associated quadratic Hamilton-Poisson systems, on the orthogonal groups SO(3) and SO(4). Specifically, we are concerned with the class of left-invariant control affine systems. We begin by classifying all cost-extended systems on SO(3) under cost equivalence. (Cost-extended systems are closely related to optimal control problems.) A classification of all quadratic Hamilton-Poisson systems on the (minus) Lie-Poisson space so(3)*, under affine equivalence, is also obtained. For the normal forms obtained in our classification (of Hamilton-Poisson systems) we investigate the (Lyapunov) stability nature of the equilibria using spectral and energy-Casimir methods. For a subclass of these systems, we obtain analytic expressions for the integral curves of the associated Hamiltonian vector fields in terms of (basic) Jacobi elliptic functions. The explicit relationship between the classification of cost-extended systems on SO(3) and the classification of quadratic Hamilton- Poisson systems on so(3)* is provided. On SO(4), a classification of all left-invariant control affine systems under L-equivalence is obtained. We then determine which of these representatives are controllable, thus obtaining a classification under detached feedback equivalence. We also obtain a partial classification of quadratic Hamilton-Poisson systems on the Lie-Poisson space so(4)*. An investigation of the stability nature of the equilibria for a subclass of these systems is also done. Several illustrative examples of optimal control problems on the orthogonal group SO(3) are provided. More specifically, we consider an optimal control problem corresponding to a representative of our classification (of cost-extended system) for each possible number of control inputs. For each of these problems, we obtain explicit expressions for the extremal trajectories on the homogeneous space S2 by projecting the extremal trajectories on the group SO(3). The examples provided show how our classifications of cost-extended systems and Hamilton-Poisson systems can be used to obtain the optimal controls and the extremal trajectories corresponding to a large class of optimal control problems on SO(3). An example of a four-input optimal control problem on SO(4) is also provided. This example is provided to show how the solutions of certain problems on SO(4) can be related to the solutions of certain optimal control problems on SO(3).
- Full Text:
- Date Issued: 2015
- Authors: Adams, Ross Montague
- Date: 2015
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/64826 , vital:28608
- Description: In this thesis we investigate a class of invariant optimal control problems, and their associated quadratic Hamilton-Poisson systems, on the orthogonal groups SO(3) and SO(4). Specifically, we are concerned with the class of left-invariant control affine systems. We begin by classifying all cost-extended systems on SO(3) under cost equivalence. (Cost-extended systems are closely related to optimal control problems.) A classification of all quadratic Hamilton-Poisson systems on the (minus) Lie-Poisson space so(3)*, under affine equivalence, is also obtained. For the normal forms obtained in our classification (of Hamilton-Poisson systems) we investigate the (Lyapunov) stability nature of the equilibria using spectral and energy-Casimir methods. For a subclass of these systems, we obtain analytic expressions for the integral curves of the associated Hamiltonian vector fields in terms of (basic) Jacobi elliptic functions. The explicit relationship between the classification of cost-extended systems on SO(3) and the classification of quadratic Hamilton- Poisson systems on so(3)* is provided. On SO(4), a classification of all left-invariant control affine systems under L-equivalence is obtained. We then determine which of these representatives are controllable, thus obtaining a classification under detached feedback equivalence. We also obtain a partial classification of quadratic Hamilton-Poisson systems on the Lie-Poisson space so(4)*. An investigation of the stability nature of the equilibria for a subclass of these systems is also done. Several illustrative examples of optimal control problems on the orthogonal group SO(3) are provided. More specifically, we consider an optimal control problem corresponding to a representative of our classification (of cost-extended system) for each possible number of control inputs. For each of these problems, we obtain explicit expressions for the extremal trajectories on the homogeneous space S2 by projecting the extremal trajectories on the group SO(3). The examples provided show how our classifications of cost-extended systems and Hamilton-Poisson systems can be used to obtain the optimal controls and the extremal trajectories corresponding to a large class of optimal control problems on SO(3). An example of a four-input optimal control problem on SO(4) is also provided. This example is provided to show how the solutions of certain problems on SO(4) can be related to the solutions of certain optimal control problems on SO(3).
- Full Text:
- Date Issued: 2015
Investigating the devolution of decision-making in the Nelson Mandela Bay Municipality
- Authors: Adams, Sandiswa
- Date: 2012
- Subjects: Decentralization in government -- South Africa -- Port Elizabeth , Decision making -- South Africa -- Port Elizabeth , Local government --South Africa -- Port Elizabeth , Municipal services -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9053 , http://hdl.handle.net/10948/d1006783 , Decentralization in government -- South Africa -- Port Elizabeth , Decision making -- South Africa -- Port Elizabeth , Local government --South Africa -- Port Elizabeth , Municipal services -- South Africa -- Port Elizabeth
- Description: The research investigates the devolution of decision-making at the Nelson Mandela Bay Municipality (NMBM). The research sets out to investigate the extent to which the Municipality offers resources to its politically elected representatives and whether the support enables a devolution that includes local citizens in decision-making. The study was demarcated within the NMBM, using an empirical survey, a population group composed of councillors and officials who work very closely with politicians in mobilizing the community in public participation. The data collection tool of choice for the study was a selfadministered questionnaire, supplemented by document analysis, unstructured interviews and the researcher’s observations. The purpose of the study is to investigate reasons why devolution is not having the desired results at NMBM, Investigate and find alternatives to how devolved decision-making can be enhanced, using the viable local political process at the NMBM and similar municipalities. The study argues from a theoretical base of good governance and public participation. The findings made were inter alia: Politicians in public office are not using the resources at their disposal optimally; tussles amongst politicians and with officials do have a negative effect on devolved decision-making; and vandalism and closing down of ward council offices are not purely a reflection of a ward councillor’s failure to account to the constituency, and the ward committee system at NMBM has not since 2009. The recommendation is that deliberate efforts need to be made to establish democratically elected ward committees in all sixty wards of NMBM. The establishment of ward committees has to be a joint effort between political office bearers, the broader political landscape and officials as previous efforts have failed to produce legitimate structures. The politicians and officials need to work together to win over public opinion and community buy-in towards the establishment of ward committees that are representative and functional.
- Full Text:
- Date Issued: 2012
- Authors: Adams, Sandiswa
- Date: 2012
- Subjects: Decentralization in government -- South Africa -- Port Elizabeth , Decision making -- South Africa -- Port Elizabeth , Local government --South Africa -- Port Elizabeth , Municipal services -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9053 , http://hdl.handle.net/10948/d1006783 , Decentralization in government -- South Africa -- Port Elizabeth , Decision making -- South Africa -- Port Elizabeth , Local government --South Africa -- Port Elizabeth , Municipal services -- South Africa -- Port Elizabeth
- Description: The research investigates the devolution of decision-making at the Nelson Mandela Bay Municipality (NMBM). The research sets out to investigate the extent to which the Municipality offers resources to its politically elected representatives and whether the support enables a devolution that includes local citizens in decision-making. The study was demarcated within the NMBM, using an empirical survey, a population group composed of councillors and officials who work very closely with politicians in mobilizing the community in public participation. The data collection tool of choice for the study was a selfadministered questionnaire, supplemented by document analysis, unstructured interviews and the researcher’s observations. The purpose of the study is to investigate reasons why devolution is not having the desired results at NMBM, Investigate and find alternatives to how devolved decision-making can be enhanced, using the viable local political process at the NMBM and similar municipalities. The study argues from a theoretical base of good governance and public participation. The findings made were inter alia: Politicians in public office are not using the resources at their disposal optimally; tussles amongst politicians and with officials do have a negative effect on devolved decision-making; and vandalism and closing down of ward council offices are not purely a reflection of a ward councillor’s failure to account to the constituency, and the ward committee system at NMBM has not since 2009. The recommendation is that deliberate efforts need to be made to establish democratically elected ward committees in all sixty wards of NMBM. The establishment of ward committees has to be a joint effort between political office bearers, the broader political landscape and officials as previous efforts have failed to produce legitimate structures. The politicians and officials need to work together to win over public opinion and community buy-in towards the establishment of ward committees that are representative and functional.
- Full Text:
- Date Issued: 2012
An investigation of the challenges and their impacts as experienced by experts at the forensic pathology services in Port Elizabeth, South Africa
- Authors: Adams, Terry
- Date: 2019
- Subjects: Forensic pathology
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/40213 , vital:35985
- Description: This study focuses on the challenges facing the workers at the Port Elizabeth Forensic Pathology Services in Gelvandale and Mount Road stations. The study follow a qualitative approach which include among others, individual interviews using an interview guide containing questions. Observation has also been used as a research tool to observe at the two stations. To supplement the above research techniques, scholarly published journal articles and books were consulted to corroborate what might have transpired in other studies similar to this one. The concept backlog has been used as a conceptual framework to understand the challenges facing the workers in this study and relevant literature has been consulted. The research finding has been outlined and finally recommendations has been made with the view of addressing some of the problems encountered by the workers.
- Full Text:
- Date Issued: 2019
- Authors: Adams, Terry
- Date: 2019
- Subjects: Forensic pathology
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/40213 , vital:35985
- Description: This study focuses on the challenges facing the workers at the Port Elizabeth Forensic Pathology Services in Gelvandale and Mount Road stations. The study follow a qualitative approach which include among others, individual interviews using an interview guide containing questions. Observation has also been used as a research tool to observe at the two stations. To supplement the above research techniques, scholarly published journal articles and books were consulted to corroborate what might have transpired in other studies similar to this one. The concept backlog has been used as a conceptual framework to understand the challenges facing the workers in this study and relevant literature has been consulted. The research finding has been outlined and finally recommendations has been made with the view of addressing some of the problems encountered by the workers.
- Full Text:
- Date Issued: 2019
Comparative phytochemical analyses of Aloe Ferox Mill. found in Eastern and Western Cape provinces in South Africa
- Authors: Adams, Zanele
- Date: 2013
- Subjects: Phytochemicals -- South Africa , Medicinal plants -- South Africa , Botanical chemistry -- South Africa , Aloe -- Analysis , Aloe -- Research -- South Africa , Aloin
- Language: English
- Type: Thesis , Masters , MSc (Botany)
- Identifier: vital:11308 , http://hdl.handle.net/10353/d1013114 , Phytochemicals -- South Africa , Medicinal plants -- South Africa , Botanical chemistry -- South Africa , Aloe -- Analysis , Aloe -- Research -- South Africa , Aloin
- Full Text:
- Date Issued: 2013
- Authors: Adams, Zanele
- Date: 2013
- Subjects: Phytochemicals -- South Africa , Medicinal plants -- South Africa , Botanical chemistry -- South Africa , Aloe -- Analysis , Aloe -- Research -- South Africa , Aloin
- Language: English
- Type: Thesis , Masters , MSc (Botany)
- Identifier: vital:11308 , http://hdl.handle.net/10353/d1013114 , Phytochemicals -- South Africa , Medicinal plants -- South Africa , Botanical chemistry -- South Africa , Aloe -- Analysis , Aloe -- Research -- South Africa , Aloin
- Full Text:
- Date Issued: 2013
Antiviral drug discovery: preparing for the next pandemic
- Adamson, Catherine S, Chibale, Kelly, Goss, Rebecca J M, Jaspars, Marcel, Newman, David J, Dorrington, Rosemary A
- Authors: Adamson, Catherine S , Chibale, Kelly , Goss, Rebecca J M , Jaspars, Marcel , Newman, David J , Dorrington, Rosemary A
- Date: 2021
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/177499 , vital:42827 , DOI: 10.1039/d0cs01118e
- Description: Clinically approved antiviral drugs are currently available for only 10 of the more than 220 viruses known to infect humans. The SARS-CoV-2 outbreak has exposed the critical need for compounds that can be rapidly mobilised for the treatment of re-emerging or emerging viral diseases, while vaccine development is underway. We review the current status of antiviral therapies focusing on RNA viruses, highlighting strategies for antiviral drug discovery and discuss the challenges, solutions and options to accelerate drug discovery efforts.
- Full Text:
- Date Issued: 2021
- Authors: Adamson, Catherine S , Chibale, Kelly , Goss, Rebecca J M , Jaspars, Marcel , Newman, David J , Dorrington, Rosemary A
- Date: 2021
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/177499 , vital:42827 , DOI: 10.1039/d0cs01118e
- Description: Clinically approved antiviral drugs are currently available for only 10 of the more than 220 viruses known to infect humans. The SARS-CoV-2 outbreak has exposed the critical need for compounds that can be rapidly mobilised for the treatment of re-emerging or emerging viral diseases, while vaccine development is underway. We review the current status of antiviral therapies focusing on RNA viruses, highlighting strategies for antiviral drug discovery and discuss the challenges, solutions and options to accelerate drug discovery efforts.
- Full Text:
- Date Issued: 2021
An investigation into the potential immunogenicity of various extracts of the South African bont tick Amblyomma hebraeum
- Authors: Adamson, Deborah Jane
- Date: 1993
- Subjects: Amblyomma -- South Africa , Ticks -- South Africa , Ticks -- Control -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4127 , http://hdl.handle.net/10962/d1015640
- Description: Rabbits and goats were inoculated with crude, membrane-associated and soluble components extracted from unengorged adult females and nymphs of the bont tick Amblyomma hebraeum. Inoculation provided some protection against nymphal infestation, however it had little effect on adult feeding. Histological examination of adults fed on inoculated hosts showed evidence of gut damage. Skin provocation testing with tick extracts elicited a Type I immediate hypersensitivity which was influenced by antihistamine. A delayed skin reaction was also evident. Whether this was attributable to Type III Arthus reaction or Type IV cell-mediated hypersensitivity was not determined. A comparative histological study of sites of tick extract injection, on inoculated and naive hosts, demonstrated the role of eosinophils in the hosts response to tick feeding. Serological examination revealed elevated anti-A hebraeum lgG titres following inoculation. These titres were found to decrease in the ten weeks after inoculation, despite the hosts being repeatedly infested with A hebraeum. Although the IgG titres of naive control hosts increased after each tick infestation, they failed to reach the titres achieved through inoculation. Western blot analysis of serum from inoculated hosts recognized most of the A. hebraeum proteins against which it was screened.
- Full Text:
- Date Issued: 1993
- Authors: Adamson, Deborah Jane
- Date: 1993
- Subjects: Amblyomma -- South Africa , Ticks -- South Africa , Ticks -- Control -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4127 , http://hdl.handle.net/10962/d1015640
- Description: Rabbits and goats were inoculated with crude, membrane-associated and soluble components extracted from unengorged adult females and nymphs of the bont tick Amblyomma hebraeum. Inoculation provided some protection against nymphal infestation, however it had little effect on adult feeding. Histological examination of adults fed on inoculated hosts showed evidence of gut damage. Skin provocation testing with tick extracts elicited a Type I immediate hypersensitivity which was influenced by antihistamine. A delayed skin reaction was also evident. Whether this was attributable to Type III Arthus reaction or Type IV cell-mediated hypersensitivity was not determined. A comparative histological study of sites of tick extract injection, on inoculated and naive hosts, demonstrated the role of eosinophils in the hosts response to tick feeding. Serological examination revealed elevated anti-A hebraeum lgG titres following inoculation. These titres were found to decrease in the ten weeks after inoculation, despite the hosts being repeatedly infested with A hebraeum. Although the IgG titres of naive control hosts increased after each tick infestation, they failed to reach the titres achieved through inoculation. Western blot analysis of serum from inoculated hosts recognized most of the A. hebraeum proteins against which it was screened.
- Full Text:
- Date Issued: 1993
Maintenance management systems of on-campus student hostels at Nigerian universities
- Authors: Adamu, Anita Dzikwi
- Date: 2015
- Subjects: School buildings -- Maintenance and repair , Dormitories -- Nigeria , Nigeria -- Student housing
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9710 , http://hdl.handle.net/10948/d1020168
- Description: Most universities have long recognised the importance and contribution of on-campus hostels to the learning process. In so doing, most of these institutions have provided and maintained building facilities for academic purposes (teaching and research). Hostels are integral components of most campuses of Nigerian universities, and they are part of the built assets of the institutions in terms of both administration and maintenance management. Currently, there is little understanding of the maintenance management systems of on-campus hostel buildings in both the public and the private universities. Moreover, there is a dearth of research evidence demonstrating that there is an appreciable difference in the maintenance management systems of the Federal, State and private universities in Nigeria. This research aimed at establishing an understanding of maintenance management systems of on-campus hostel buildings at Nigerian universities owned by the Federal and State governments and the Private Sector, relative to stipulated criteria for best practice.The qualitative method of research inquiry that is rooted in the phenomenological paradigm was employed in the investigations. The research activities included a comprehensive review of the related literature and study of selected cases. The North-central geopolitical zone of Nigeria was the selected geographical scope of this research. Ten universities were purposefully selected for the study, and they include three Federal, four state and three private universities. The nature and differences in the research questions necessitated generating different forms of data. The questions that were related to the maintenance management systems for the hostels in place at the universities were addressed with the outcomes of interviews with the hostel managers. The questions that were about the structures and current conditions of the hostel buildings at the three categories of universities were addressed with data that were generated from condition assessments of the facilities and physical observations with the aid of cameras. The study reveals apparent deteriorated and unhealthy conditions of most of the on-campus hostels at the public universities, while those of the private universities are satisfactory. The research also found that the maintenance management systems in use at all the universities are reactive and lack proper planning and coordination of maintenance activities. There is no significant difference in the maintenance management systems of hostels at the public and the private universities and the systems have major negative impact on the conditions of the buildings and their performances. The research has developed a conceptual model for the study of maintenance management informed by the theoretical framework. The model considered the impact of the external environmental factors on the management and maintenance of the hostels. Secondly, the interrelationships of strategic and performance management with maintenance management in developing an effective maintenance management system were established. The study has achieved its aim of establishing an understanding of maintenance management systems of on-campus hostel buildings at Nigerian universities owned by the Federal and, State governments and the Private Sector. The maintenance management model developed in the study is recommended to maintenance management departments as a guide for effective maintenance of the built facilities in their institutions.
- Full Text:
- Date Issued: 2015
- Authors: Adamu, Anita Dzikwi
- Date: 2015
- Subjects: School buildings -- Maintenance and repair , Dormitories -- Nigeria , Nigeria -- Student housing
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9710 , http://hdl.handle.net/10948/d1020168
- Description: Most universities have long recognised the importance and contribution of on-campus hostels to the learning process. In so doing, most of these institutions have provided and maintained building facilities for academic purposes (teaching and research). Hostels are integral components of most campuses of Nigerian universities, and they are part of the built assets of the institutions in terms of both administration and maintenance management. Currently, there is little understanding of the maintenance management systems of on-campus hostel buildings in both the public and the private universities. Moreover, there is a dearth of research evidence demonstrating that there is an appreciable difference in the maintenance management systems of the Federal, State and private universities in Nigeria. This research aimed at establishing an understanding of maintenance management systems of on-campus hostel buildings at Nigerian universities owned by the Federal and State governments and the Private Sector, relative to stipulated criteria for best practice.The qualitative method of research inquiry that is rooted in the phenomenological paradigm was employed in the investigations. The research activities included a comprehensive review of the related literature and study of selected cases. The North-central geopolitical zone of Nigeria was the selected geographical scope of this research. Ten universities were purposefully selected for the study, and they include three Federal, four state and three private universities. The nature and differences in the research questions necessitated generating different forms of data. The questions that were related to the maintenance management systems for the hostels in place at the universities were addressed with the outcomes of interviews with the hostel managers. The questions that were about the structures and current conditions of the hostel buildings at the three categories of universities were addressed with data that were generated from condition assessments of the facilities and physical observations with the aid of cameras. The study reveals apparent deteriorated and unhealthy conditions of most of the on-campus hostels at the public universities, while those of the private universities are satisfactory. The research also found that the maintenance management systems in use at all the universities are reactive and lack proper planning and coordination of maintenance activities. There is no significant difference in the maintenance management systems of hostels at the public and the private universities and the systems have major negative impact on the conditions of the buildings and their performances. The research has developed a conceptual model for the study of maintenance management informed by the theoretical framework. The model considered the impact of the external environmental factors on the management and maintenance of the hostels. Secondly, the interrelationships of strategic and performance management with maintenance management in developing an effective maintenance management system were established. The study has achieved its aim of establishing an understanding of maintenance management systems of on-campus hostel buildings at Nigerian universities owned by the Federal and, State governments and the Private Sector. The maintenance management model developed in the study is recommended to maintenance management departments as a guide for effective maintenance of the built facilities in their institutions.
- Full Text:
- Date Issued: 2015
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
Cloud computing adoption: Strategies for Sub-Saharan Africa SMEs for enhancing competitiveness
- Authors: Adane, Martin
- Date: 2018
- Subjects: business intelligence small businesses business planning Article
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/6862 , vital:51101 , xlink:href="https://doi.org/10.1080/20421338.2018.1439288"
- Description: Small and medium-sized enterprises (SMEs) need to design and implement strategies for adopting new technologies as a competitive tool for maintaining their competitive advantage and cloud computing is at its peak. 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 SMEs. This paper primarily explores cloud computing adoption strategies for SMEs operating in Sub-Saharan Africa. Using a mixed method approach, a sample of 261 respondents and 11 SMEs was respectively used for the quantitative and qualitative stages of the research. The results reveal that, even though SMEs have their unique expectations for adopting cloud computing, they were of the consensus that elements of an adoption strategy should include adoption goals, a roadmap, and considerations. The paper makes specific recommendations to SMEs to develop adoption strategies that meet their specific needs if they expect cloud computing to play a stronger role to support more strategic initiatives to grow their businesses and improve customer experience.
- Full Text:
- Date Issued: 2018
- Authors: Adane, Martin
- Date: 2018
- Subjects: business intelligence small businesses business planning Article
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/6862 , vital:51101 , xlink:href="https://doi.org/10.1080/20421338.2018.1439288"
- Description: Small and medium-sized enterprises (SMEs) need to design and implement strategies for adopting new technologies as a competitive tool for maintaining their competitive advantage and cloud computing is at its peak. 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 SMEs. This paper primarily explores cloud computing adoption strategies for SMEs operating in Sub-Saharan Africa. Using a mixed method approach, a sample of 261 respondents and 11 SMEs was respectively used for the quantitative and qualitative stages of the research. The results reveal that, even though SMEs have their unique expectations for adopting cloud computing, they were of the consensus that elements of an adoption strategy should include adoption goals, a roadmap, and considerations. The paper makes specific recommendations to SMEs to develop adoption strategies that meet their specific needs if they expect cloud computing to play a stronger role to support more strategic initiatives to grow their businesses and improve customer experience.
- Full Text:
- Date Issued: 2018
Strategies to facilitate the use of birth care provided by skilled birth attendants in the rural areas of Ghana
- Authors: Adatara, Peter
- Date: 2018
- Subjects: Maternity nursing -- Ghana , Neonatal nursing -- methods Delivery (Obstetrics) Midwifery -- Ghana
- Language: English
- Type: Thesis , Doctoral , DCur
- Identifier: http://hdl.handle.net/10948/23415 , vital:30541
- Description: Increasing skilled attendance during childbirth is well established in literature to play a significant role in averting the many preventable maternal deaths that occur in developing countries such as Ghana.Inadequate utilisation of skilled birth care services in Sub-Saharan Africa is believed to be a major hindrance to efforts aimed at improving the health of women, especially during delivery. There is low utilisation of birth care services provided by skilled birth attendants in the rural areas in Ghana. The purpose of this study was to develop strategies that could facilitate the utilisation of skilled birth care provided by skilled birth attendants in the rural areas of Ghana. The study adopted a qualitative, explorative, descriptive and contextual method to explore and describe women’s experiences regarding the utilisation or non-utilisation of skilled birth care services provided by skilled birth attendants in the rural areas in Ghana. The study was conducted in three phases: Phase One of this study described the research population, sampling method, data collection and analysis to obtain women’s experiences regarding the utilisation or non-utilisation of skilled birth care services. In this study, data were collected and analysed from the research population. The research population consisted of women who utilised skilled birth care attendants or unskilled care attendants during child birth. The data collection method used was individual interviews. Data collected from the interviews were transcribed verbatim and analysed according to the steps suggested by Tesch to identify themes and sub-themes. The study identified three themes and sub-themes: Theme 1: Experiences of participants related to the use of skilled birth care attendants; Theme 2: Participants expressed their reasons for choosing a home birth; Theme 3: Participants offered suggestions to improve skilled birth care at healthcare facilities. The findings in Phase one of this study formed the basis for the development of the strategies in Phase three. Phase Two of the research design focused on the development of a conceptual framework based on the research findings and utilized to develop strategies which skilled birth attendant may use to facilitate the use of skilled birth care services by women in the rural areas of Ghana where there is low utilisation of birth services provided by skilled birth attendants. The conceptual framework of Dickoff, James and Wiedenbach was used to provide a guide and a link between the different concepts in the research study. Phase Three of this study focused on the development of strategies that will facilitate an increased in the labouring women utilisation of the services provided by skilled birth attendants. The data obtained was used to developed three strategies such as collaboration, education and training, supportive supervision as well as community mobilisation and participation to guide skilled birth attendants to facilitate the utilisation of skilled birth care services during childbirth. The WHO Health for All model, the theoretical model underpinning this study, also guided the development of the strategies to facilitate labouring women utilisation of the services provided by skilled birth attendants. Recommendations regarding the implementation of a national collaborative, education and supportive supervision policies on a macro level are made, as well as recommendations for nursing practice, education and research. It is therefore concluded that the researcher succeeded in achieving the purpose for this study because the strategies which are understandable, clear, simple, applicable and significant to skilled birth care in rural areas has been developed for use by skilled birth attendants to facilitate the utilisation of skilled birth care provided by skilled birth attendants in the rural areas of Ghana.
- Full Text:
- Date Issued: 2018
- Authors: Adatara, Peter
- Date: 2018
- Subjects: Maternity nursing -- Ghana , Neonatal nursing -- methods Delivery (Obstetrics) Midwifery -- Ghana
- Language: English
- Type: Thesis , Doctoral , DCur
- Identifier: http://hdl.handle.net/10948/23415 , vital:30541
- Description: Increasing skilled attendance during childbirth is well established in literature to play a significant role in averting the many preventable maternal deaths that occur in developing countries such as Ghana.Inadequate utilisation of skilled birth care services in Sub-Saharan Africa is believed to be a major hindrance to efforts aimed at improving the health of women, especially during delivery. There is low utilisation of birth care services provided by skilled birth attendants in the rural areas in Ghana. The purpose of this study was to develop strategies that could facilitate the utilisation of skilled birth care provided by skilled birth attendants in the rural areas of Ghana. The study adopted a qualitative, explorative, descriptive and contextual method to explore and describe women’s experiences regarding the utilisation or non-utilisation of skilled birth care services provided by skilled birth attendants in the rural areas in Ghana. The study was conducted in three phases: Phase One of this study described the research population, sampling method, data collection and analysis to obtain women’s experiences regarding the utilisation or non-utilisation of skilled birth care services. In this study, data were collected and analysed from the research population. The research population consisted of women who utilised skilled birth care attendants or unskilled care attendants during child birth. The data collection method used was individual interviews. Data collected from the interviews were transcribed verbatim and analysed according to the steps suggested by Tesch to identify themes and sub-themes. The study identified three themes and sub-themes: Theme 1: Experiences of participants related to the use of skilled birth care attendants; Theme 2: Participants expressed their reasons for choosing a home birth; Theme 3: Participants offered suggestions to improve skilled birth care at healthcare facilities. The findings in Phase one of this study formed the basis for the development of the strategies in Phase three. Phase Two of the research design focused on the development of a conceptual framework based on the research findings and utilized to develop strategies which skilled birth attendant may use to facilitate the use of skilled birth care services by women in the rural areas of Ghana where there is low utilisation of birth services provided by skilled birth attendants. The conceptual framework of Dickoff, James and Wiedenbach was used to provide a guide and a link between the different concepts in the research study. Phase Three of this study focused on the development of strategies that will facilitate an increased in the labouring women utilisation of the services provided by skilled birth attendants. The data obtained was used to developed three strategies such as collaboration, education and training, supportive supervision as well as community mobilisation and participation to guide skilled birth attendants to facilitate the utilisation of skilled birth care services during childbirth. The WHO Health for All model, the theoretical model underpinning this study, also guided the development of the strategies to facilitate labouring women utilisation of the services provided by skilled birth attendants. Recommendations regarding the implementation of a national collaborative, education and supportive supervision policies on a macro level are made, as well as recommendations for nursing practice, education and research. It is therefore concluded that the researcher succeeded in achieving the purpose for this study because the strategies which are understandable, clear, simple, applicable and significant to skilled birth care in rural areas has been developed for use by skilled birth attendants to facilitate the utilisation of skilled birth care provided by skilled birth attendants in the rural areas of Ghana.
- Full Text:
- Date Issued: 2018
Household food insecurity and its association with psychological well-being of pregnant women in Ghana: the role of selected psychosocial factors
- Authors: Addai, Prince
- Date: 2020
- Subjects: Food security -- Ghana Households -- Ghana Self-reliance
- Language: English
- Type: Thesis , Doctoral , PhD (Industrial Psychology)
- Identifier: http://hdl.handle.net/10353/12547 , vital:39286
- Description: The inability to get enough food has contributed immensely to dangers confronting pregnant women, especially in the developing countries. Food insecurity has been associated with a variety of negative consequences such as poor health and wellbeing. However, the impact of food insecurity on well-being has not received the needed attention by researchers in Sub-Saharan Africa where the state of food insecurity and its consequence is very pandemic. The objective of this study was to assess the impact of food insecurity on psychological well-being and its components among pregnant women in Northern Ghana and to assess the roles of self-esteem, locus of control, proactivity, and social support on the underlying relationship. The cross-sectional survey was adopted where 386 pregnant women were recruited to complete questionnaires on demographic, some psychological factors, psychological well-being and food insecurity. Dimensionality and Item analyses were conducted to detect complex and poor items and also to ensure unidimensionality. Regression analysis, MANOVA, Baron and Kenney Model of moderation and mediation, the multivariate ANOVA and the Two-way ANOVA were used to test the hypotheses. Results indicated that the measurement and the structural models showed a good fit with the observed data. Results showed that about 37.5% (n=144) out of the 384 pregnant women experienced severe food insecurity. Food insecurity was negatively significantly related with psychological well-being and all its components among pregnant women. Food insecurity elucidated 48.5% of the observed variance of food insecurity. Food insecurity correlated highly to personal growth (β = -.327) element of psychological well-being compared to autonomy (β = -.227), interpersonal relationship (β = -.207), environmental mastery (β = -.168), self-acceptance (β = -.117), and of purpose in life (β = -.107). Self-esteem and locus of control mediated the relationship between food insecurity and psychological well-being. Proactivity and social support also moderated the nexus between food insecurity and psychological well-being. 4 Final Submission of Thesis, Dissertation or Research Report/Project, Conference or Exam Paper Having higher income status and being employed were associated positively with higher psychological well-being. Support was not found for the nexus between marital status and age with psychological well-being. Recommendations are made for pregnant mothers to be supported and empowered to boost their self-esteem and make them proactive.
- Full Text:
- Date Issued: 2020
- Authors: Addai, Prince
- Date: 2020
- Subjects: Food security -- Ghana Households -- Ghana Self-reliance
- Language: English
- Type: Thesis , Doctoral , PhD (Industrial Psychology)
- Identifier: http://hdl.handle.net/10353/12547 , vital:39286
- Description: The inability to get enough food has contributed immensely to dangers confronting pregnant women, especially in the developing countries. Food insecurity has been associated with a variety of negative consequences such as poor health and wellbeing. However, the impact of food insecurity on well-being has not received the needed attention by researchers in Sub-Saharan Africa where the state of food insecurity and its consequence is very pandemic. The objective of this study was to assess the impact of food insecurity on psychological well-being and its components among pregnant women in Northern Ghana and to assess the roles of self-esteem, locus of control, proactivity, and social support on the underlying relationship. The cross-sectional survey was adopted where 386 pregnant women were recruited to complete questionnaires on demographic, some psychological factors, psychological well-being and food insecurity. Dimensionality and Item analyses were conducted to detect complex and poor items and also to ensure unidimensionality. Regression analysis, MANOVA, Baron and Kenney Model of moderation and mediation, the multivariate ANOVA and the Two-way ANOVA were used to test the hypotheses. Results indicated that the measurement and the structural models showed a good fit with the observed data. Results showed that about 37.5% (n=144) out of the 384 pregnant women experienced severe food insecurity. Food insecurity was negatively significantly related with psychological well-being and all its components among pregnant women. Food insecurity elucidated 48.5% of the observed variance of food insecurity. Food insecurity correlated highly to personal growth (β = -.327) element of psychological well-being compared to autonomy (β = -.227), interpersonal relationship (β = -.207), environmental mastery (β = -.168), self-acceptance (β = -.117), and of purpose in life (β = -.107). Self-esteem and locus of control mediated the relationship between food insecurity and psychological well-being. Proactivity and social support also moderated the nexus between food insecurity and psychological well-being. 4 Final Submission of Thesis, Dissertation or Research Report/Project, Conference or Exam Paper Having higher income status and being employed were associated positively with higher psychological well-being. Support was not found for the nexus between marital status and age with psychological well-being. Recommendations are made for pregnant mothers to be supported and empowered to boost their self-esteem and make them proactive.
- Full Text:
- Date Issued: 2020
Probing learners' conceptual understanding of oxidation and reduction (redox) reactions : a case study
- Authors: Addam, Billey Bright
- Date: 2004
- Subjects: Competency based education -- South Africa Oxidation-reduction reaction -- Study and teaching Science -- Study and teaching -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1409 , http://hdl.handle.net/10962/d1002950
- Description: The new political dispensation in South Africa has seen a lot of changes taking place. The democratic wind, which has been blowing in all spheres of the political arena, could not leave out Education. This has led to the transformation in education and the revision of the curriculum guided by the Outcomes-Based Education philosophy (OBE). Thus, require education authorities as well as educators to look at education more comprehensively. The challenge posed to educators now is to develop tools and strategies that will make learning accessible to as many learners as possible and to teach for understanding and construction of knowledge. The principal objective of this study was to investigate the important role the learner's prior knowledge plays and the use of different tools and strategies in stimulating conceptual understanding and construction of knowledge of redox reactions. This was done using learners' own investigations, practical activities, teaching settings and a workshop. The findings show that the learners lacked organized and structured prior knowledge. Learners could not integrate prior experience with new experience. The main issue seems to be the failure of learners to relate classroom experience to everyday redox phenomena. Possible reasons are discussed with some implications for teaching redox. The study further postulates that to assist learners to develop conceptual understanding of redox reactions, different tools and strategies should be employed and teaching made relevant to real-life situations. In so doing, redox concepts would not be abstract to learners.
- Full Text:
- Date Issued: 2004
- Authors: Addam, Billey Bright
- Date: 2004
- Subjects: Competency based education -- South Africa Oxidation-reduction reaction -- Study and teaching Science -- Study and teaching -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1409 , http://hdl.handle.net/10962/d1002950
- Description: The new political dispensation in South Africa has seen a lot of changes taking place. The democratic wind, which has been blowing in all spheres of the political arena, could not leave out Education. This has led to the transformation in education and the revision of the curriculum guided by the Outcomes-Based Education philosophy (OBE). Thus, require education authorities as well as educators to look at education more comprehensively. The challenge posed to educators now is to develop tools and strategies that will make learning accessible to as many learners as possible and to teach for understanding and construction of knowledge. The principal objective of this study was to investigate the important role the learner's prior knowledge plays and the use of different tools and strategies in stimulating conceptual understanding and construction of knowledge of redox reactions. This was done using learners' own investigations, practical activities, teaching settings and a workshop. The findings show that the learners lacked organized and structured prior knowledge. Learners could not integrate prior experience with new experience. The main issue seems to be the failure of learners to relate classroom experience to everyday redox phenomena. Possible reasons are discussed with some implications for teaching redox. The study further postulates that to assist learners to develop conceptual understanding of redox reactions, different tools and strategies should be employed and teaching made relevant to real-life situations. In so doing, redox concepts would not be abstract to learners.
- Full Text:
- Date Issued: 2004
Integrating information and communications technology (ICT) into teaching and learning: the case of mathematics, science and technology education in one higher education institution
- Authors: Addam, Billey Bright Kwadwo
- Date: 2014
- Subjects: Educational teaching -- South Africa , Computer-assisted instruction -- South Africa , Mathematics -- Study and teaching -- South Africa , Science -- Study and teaching -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD (Education)
- Identifier: vital:16224 , http://hdl.handle.net/10353/d1019736 , Educational teaching -- South Africa , Computer-assisted instruction -- South Africa , Mathematics -- Study and teaching -- South Africa , Science -- Study and teaching -- South Africa
- Description: This study explores the integration of Information and Communication Technologies (ICT) into teaching and learning within one Higher Education institution. The main question driving the study was: How is ICT integrated in the teaching and learning of mathematics, science and technology education (MSTE) in a Bachelor of Education programme? This is a case study of lecturers and students in Mathematics, Science and Technology Education. It makes use of questionnaires, interviews, field notes and document analyses to collect data. MSTE lecturers and students were assumed to be well versed in ICT usage and, therefore, well placed to assess its integration into teaching and learning. There were five main findings: First, that Mathematics, Science and Technology Education lecturers showed some ambivalence in their ontological and epistemological orientation to using ICT. Some leaned towards the instruction paradigm and used ICT as a tool for the transmission of knowledge; others leaned towards the learning paradigm, showing an awareness of the need to elicit discovery through ICT. Secondly, that lecturers’ understanding of ICT integration was oriented towards teaching and learning from technologies rather than with technologies. Thirdly, that processes of ‘pedagogical evolution’ were taking place, in terms of which there was a gradual but perceptible shift in the teaching and learning practice of both students and lecturers. Fourthly, there was no evidence to show that lecturers used ICT to promote innovative and creative teaching; in fact, students appeared to be more creative in using ICT resources, than lecturers. Fifthly, and finally, lecturers did not assign ICT-based tasks that promote conceptual understanding. They assigned tasks that asked students to extract and reproduce information from computers, without demonstrating understanding. When used in this way, ICT can, in fact, be de-skilling. From these findings, it can be concluded that ICT integration cannot be understood without exploring the ontological and epistemological orientations, as well as the theoretical orientations, at play in the teaching and learning situation. It is on the basis of these that people, that is, lecturers and students, make use of, ICTs to achieve desired goals. It is therefore recommended that, for the improvement of integration, there should be a greater emphasis on developing and sharing pedagogical expertise concerning ICT use in teaching and learning. It is recommended that a country-wide research survey should be undertaken, based on probability sampling and focussing on pedagogical issues in ICT integration in teaching and learning.
- Full Text:
- Date Issued: 2014
- Authors: Addam, Billey Bright Kwadwo
- Date: 2014
- Subjects: Educational teaching -- South Africa , Computer-assisted instruction -- South Africa , Mathematics -- Study and teaching -- South Africa , Science -- Study and teaching -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD (Education)
- Identifier: vital:16224 , http://hdl.handle.net/10353/d1019736 , Educational teaching -- South Africa , Computer-assisted instruction -- South Africa , Mathematics -- Study and teaching -- South Africa , Science -- Study and teaching -- South Africa
- Description: This study explores the integration of Information and Communication Technologies (ICT) into teaching and learning within one Higher Education institution. The main question driving the study was: How is ICT integrated in the teaching and learning of mathematics, science and technology education (MSTE) in a Bachelor of Education programme? This is a case study of lecturers and students in Mathematics, Science and Technology Education. It makes use of questionnaires, interviews, field notes and document analyses to collect data. MSTE lecturers and students were assumed to be well versed in ICT usage and, therefore, well placed to assess its integration into teaching and learning. There were five main findings: First, that Mathematics, Science and Technology Education lecturers showed some ambivalence in their ontological and epistemological orientation to using ICT. Some leaned towards the instruction paradigm and used ICT as a tool for the transmission of knowledge; others leaned towards the learning paradigm, showing an awareness of the need to elicit discovery through ICT. Secondly, that lecturers’ understanding of ICT integration was oriented towards teaching and learning from technologies rather than with technologies. Thirdly, that processes of ‘pedagogical evolution’ were taking place, in terms of which there was a gradual but perceptible shift in the teaching and learning practice of both students and lecturers. Fourthly, there was no evidence to show that lecturers used ICT to promote innovative and creative teaching; in fact, students appeared to be more creative in using ICT resources, than lecturers. Fifthly, and finally, lecturers did not assign ICT-based tasks that promote conceptual understanding. They assigned tasks that asked students to extract and reproduce information from computers, without demonstrating understanding. When used in this way, ICT can, in fact, be de-skilling. From these findings, it can be concluded that ICT integration cannot be understood without exploring the ontological and epistemological orientations, as well as the theoretical orientations, at play in the teaching and learning situation. It is on the basis of these that people, that is, lecturers and students, make use of, ICTs to achieve desired goals. It is therefore recommended that, for the improvement of integration, there should be a greater emphasis on developing and sharing pedagogical expertise concerning ICT use in teaching and learning. It is recommended that a country-wide research survey should be undertaken, based on probability sampling and focussing on pedagogical issues in ICT integration in teaching and learning.
- Full Text:
- Date Issued: 2014
A study of the heroine in certain Victorian novels
- Authors: Addecott, Grahame John
- Date: 1959
- Subjects: English fiction -- 19th century -- History and criticism , Heroines in literature
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2319 , http://hdl.handle.net/10962/d1013374
- Description: During the reign of Queen Victoria was seen the gradual emergence of the emancipated woman. The idea that women were innocent beings who must be kept from real knowledge of the world died hard, however, and to the end of the era there were many who repudiated the very concept of emancipation whether in literature or life. Coupled with the chivalrous, idealistic concept of womanhood was Victorian respectability, and it is not surprising that in the earlier Victorian novels we see clearly the idealistic concept of women and the effects of the cult of respectability. To illustrate my theme, of the gradual change in the concept of the novel which naturally kept pace, more or less, with the progress the emancipation of women was making, I have chosen one novel from each of seven great Victorian novelists whose works span the whale era. The only exception I have made is with Charlotte Bronte. In her case the heroines of two of her novels are discussed mainly because she is the first Victorian novelist to sound a note of protest against the then conventional concept of the heroine.
- Full Text:
- Date Issued: 1959
- Authors: Addecott, Grahame John
- Date: 1959
- Subjects: English fiction -- 19th century -- History and criticism , Heroines in literature
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2319 , http://hdl.handle.net/10962/d1013374
- Description: During the reign of Queen Victoria was seen the gradual emergence of the emancipated woman. The idea that women were innocent beings who must be kept from real knowledge of the world died hard, however, and to the end of the era there were many who repudiated the very concept of emancipation whether in literature or life. Coupled with the chivalrous, idealistic concept of womanhood was Victorian respectability, and it is not surprising that in the earlier Victorian novels we see clearly the idealistic concept of women and the effects of the cult of respectability. To illustrate my theme, of the gradual change in the concept of the novel which naturally kept pace, more or less, with the progress the emancipation of women was making, I have chosen one novel from each of seven great Victorian novelists whose works span the whale era. The only exception I have made is with Charlotte Bronte. In her case the heroines of two of her novels are discussed mainly because she is the first Victorian novelist to sound a note of protest against the then conventional concept of the heroine.
- Full Text:
- Date Issued: 1959
Intimacy in romantic relationships during young adulthood: the role of the mother-daughter relationship
- Authors: Addinall, Elizabeth Liezl
- Date: 2008
- Subjects: Intimacy (Psychology) , Parent and child , Mothers and daughters
- Language: English
- Type: Thesis , Masters , M Soc Sc (C Psy)
- Identifier: vital:11850 , http://hdl.handle.net/10353/160 , Intimacy (Psychology) , Parent and child , Mothers and daughters
- Description: This study addressed the role of the mother-daughter relationship on the daughter‟s development of the capacity for intimacy with a romantic partner. The objective of this study was to examine whether separateness in mother-daughter interactions was related to romantic intimacy (sexual and non-sexual intimacy) in romantic relationships. The following instruments were used: 1) Socio-demographic questionnaire; 2) Competence in Mother-Daughter Relationship Questionnaire (ICQ-M) and 3) Personal Assessment of Intimacy Questionnaire (PAIR). 179 adolescent female university students participated in this study most of who were between the ages of 20 and 24. The results indicated that a positive relationship existed between separateness and sexual intimacy (r=.688, p<.01) as well as separateness and non-sexual intimacy (r=.598, p<.01). A positive relationship between connectedness and non-sexual intimacy (r=.468, p<.01) was also observed, however no correlation was observed between connectedness and sexual intimacy. These findings indicate that separateness in mother-daughter interactions has a definite effect on the different dimensions of romantic intimacy. Therefore, late adolescent women who possess the ability to assert themselves and express differences between themselves and their mothers are not as apprehensive as their peers when it comes to romantic intimacy with a partner.
- Full Text:
- Date Issued: 2008
- Authors: Addinall, Elizabeth Liezl
- Date: 2008
- Subjects: Intimacy (Psychology) , Parent and child , Mothers and daughters
- Language: English
- Type: Thesis , Masters , M Soc Sc (C Psy)
- Identifier: vital:11850 , http://hdl.handle.net/10353/160 , Intimacy (Psychology) , Parent and child , Mothers and daughters
- Description: This study addressed the role of the mother-daughter relationship on the daughter‟s development of the capacity for intimacy with a romantic partner. The objective of this study was to examine whether separateness in mother-daughter interactions was related to romantic intimacy (sexual and non-sexual intimacy) in romantic relationships. The following instruments were used: 1) Socio-demographic questionnaire; 2) Competence in Mother-Daughter Relationship Questionnaire (ICQ-M) and 3) Personal Assessment of Intimacy Questionnaire (PAIR). 179 adolescent female university students participated in this study most of who were between the ages of 20 and 24. The results indicated that a positive relationship existed between separateness and sexual intimacy (r=.688, p<.01) as well as separateness and non-sexual intimacy (r=.598, p<.01). A positive relationship between connectedness and non-sexual intimacy (r=.468, p<.01) was also observed, however no correlation was observed between connectedness and sexual intimacy. These findings indicate that separateness in mother-daughter interactions has a definite effect on the different dimensions of romantic intimacy. Therefore, late adolescent women who possess the ability to assert themselves and express differences between themselves and their mothers are not as apprehensive as their peers when it comes to romantic intimacy with a partner.
- Full Text:
- Date Issued: 2008
Censorship of the press in South Africa during the Angolan War: a case study of news manipulation and suppression
- Authors: Addison, Graeme
- Date: 1982
- Subjects: Mass media -- Censorship -- South Africa Censorship -- South Africa Mass media -- Censorship -- South Africa Government and the press -- South Africa Freedom of the press -- South Africa Angola -- History -- Civil War, 1975-2002 Angola -- History -- South African Invasion, 1975-1976
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3495 , http://hdl.handle.net/10962/d1003058
- Description: During the Angolan War of 1975-6, whilst South African troops were actively engaged on the side of the Unita/FNLA alliance, news media in South Africa were prohibited from disclosing information about the country's role in the war. Under Section 118 of the Defence Amendment Act of 1967, no information about SA troop movements or plans could be published without the permission of the Minister of Defence or his nominees. This case study shows how the Government used the Defence Act to censor certain news while releasing other news which suited its political outlook and objectives. The study documents the history of the Defence Act and of the military-press liaison machinery which grew out of it. The introduction defines propaganda as a technique of ideological control designed to supplement the control of society by means of repression. The study sets in context the Government's propaganda strategy before, during and after the Angolan War, arguing that the structures of white domination, including the newspaper industry, are being drawn into the Government's scheme of total co-ordination to fight a total war.
- Full Text:
- Date Issued: 1982
- Authors: Addison, Graeme
- Date: 1982
- Subjects: Mass media -- Censorship -- South Africa Censorship -- South Africa Mass media -- Censorship -- South Africa Government and the press -- South Africa Freedom of the press -- South Africa Angola -- History -- Civil War, 1975-2002 Angola -- History -- South African Invasion, 1975-1976
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3495 , http://hdl.handle.net/10962/d1003058
- Description: During the Angolan War of 1975-6, whilst South African troops were actively engaged on the side of the Unita/FNLA alliance, news media in South Africa were prohibited from disclosing information about the country's role in the war. Under Section 118 of the Defence Amendment Act of 1967, no information about SA troop movements or plans could be published without the permission of the Minister of Defence or his nominees. This case study shows how the Government used the Defence Act to censor certain news while releasing other news which suited its political outlook and objectives. The study documents the history of the Defence Act and of the military-press liaison machinery which grew out of it. The introduction defines propaganda as a technique of ideological control designed to supplement the control of society by means of repression. The study sets in context the Government's propaganda strategy before, during and after the Angolan War, arguing that the structures of white domination, including the newspaper industry, are being drawn into the Government's scheme of total co-ordination to fight a total war.
- Full Text:
- Date Issued: 1982
Plastochron index - an indicator of plant structure and function a case study using Pisum sativum L
- Ade-Ademilua, Omobolanle Elizabeth
- Authors: Ade-Ademilua, Omobolanle Elizabeth
- Date: 2006
- Subjects: Plant anatomy Plant physiology Peas -- Anatomy Peas -- Physiology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4183 , http://hdl.handle.net/10962/d1003751
- Description: The use of chronological age for example, using days after sowing (DAS), or days after germination (DAG) as a time variable may result in the inherent variability between plants resulting in differences which can be large enough to obscure subtle developmental trends that become evident among plants sown at the same time. An alternative to DAS or DAG is the plastochron index (PI), first used by Erickson and Michelini (1957) as a morphological time scale and numerical index; which to according to the authors suggested and represented a more accurate reflection of the developmental status of a plant. The research presented in this thesis was therefore aimed specifically at utilizing the index in qualitative and quantitative analyses, to confirm its usefulness in analyzing and predicting plant growth and development. Specifically this research focused on investigating various morphological and physiological events that together, hopefully, would serve as a template for the prediction of the growth, development and reactions of Pisum sativum L. to different growth conditions. In Chapter 3, the use of the average length of the first pair of leaflets on each node as a suitable parameter for calculating PI in P. sativum is suggested. The results presented in Chapter 3 suggest that plant age is best expressed using the plastochron index, as this reflects the time interval between the initiations of successive pairs of leaflets. This section of the research has been published as “Ade-Ademilua OE, Botha CEJ (2005) A re-evaluation of plastochron index in peas - a case for using leaflet length. South African Journal of Botany 71: 76-80”. The PI formula developed was subsequently used in this research to conduct qualitative and quantitative investigations of plant growth and development in which all data and observations were related directly to the plastochron index. In Chapter 4, the sink to source transition in Pisum sativum L. leaves at different plastochron ages in nodulating plants was investigated using the phloem-mobile fluorescent marker, 5,6-carboxyfluorescein (5,6-CF). The results demonstrated that young leaves remained strong sinks up until LPI 0, after which sink-source transition occurred up to LPI 1.8 and leaflets transitioned to strong source systems by LPI 2.0. A well-developed cross-connected phloem system between paired leaflets in peas, and the petiole and the stem vascular supply was observed. The data presented in the second part of Chapter 4 suggest that the phloem transport between leaflet pairs is independent of the sink/source state of the leaflets, or of movement along the source to sink gradient. The data support the presence of a modular transport system which may ensure re-allocation and balancing between leaflets of the same physiological age and photosynthetic and transport status, thereby load-balancing the local transport system, before exporting to other younger (sink) regions. The investigation of leaf development using the plastochron index (Chapter 5) revealed that the formation of air spaces in the palisade and spongy mesophyll, one of the preparatory events for transition from sink to source state in developing leaves, occurs between LPI 0 and LPI 1 in pea leaflets. Results of the anatomical and ultrastructural study related to PI are presented in Chapter 5. The density of wall ingrowths in transfer cells of minor veins increased with LPI and appeared to be associated with the probable transition to source state and the related potential increase in the production of assimilates for export. The onset of wall ingrowth development in leaflets at LPI 0 provided evidence that sink-to-source transition commences at LPI 0 in P. sativum. Presumably-functional plasmodesmata as well as a few mature sieve elements were evident in class IV veins in the apical region of young and older leaflets at LPI 0. The number of mature sieve elements per vein however, increased with increasing LPI. Most class V veins were still undergoing division at LPI 0 and their sieve elements did not show signs of maturity until LPI 1. The increase in the number of mature metaphloem sieve elements in young, supposedly importing tissue at LPI 0 to older, supposedly exporting tissues at LPI 2 is evidence of the association between phloem maturation and transition from importing to exporting status. In Chapter 6, I report on the effects of elevated CO[subscript 2] on the growth and leaf development of nodulating and non-nodulating Pisum sativum L var. Greenfeast grown under controlled environment of the same nitrogen (6mM) and nitrogen- free nutrient solution conditions. Shortterm exposure to elevated CO[subscript 2] induced rapid plant growth, irrespective of treatment. However, long-term elevated CO[subscript 2] treatment did not affect rate of leaf appearance (RLA) in nodulated plants, irrespective of mineral N supply but enhanced RLA in non- nodulating plants supplied with mineral N. Supplied N resulted in a significant increase in leaflet elongation rate (LfER) under both ambient and elevated CO[subscript 2], but LfER was not significantly affected by nodulation but was increased by high CO[subscript 2]. This suggested that the growth of nodulating P. sativum L may not be significantly affected under CO[subscript 2] levels as high as 1000 μmol mol[superscript -1]. The data suggest that elevated CO[subscript 2] will enhance canopy size, provided adequate soil N is available and more so in non-nodulating plants. This section of the research has been published as “Ade-Ademilua OE, Botha CEJ (2004) The effects of elevated CO[subscript 2] and nitrogen availability supersedes the need for nodulation in peas grown under controlled environmental conditions. South African Journal of Botany 70: 816 – 823”. This thesis demonstrates that the similarity in the qualitative analyses results obtained from plants from different CO[subscript 2], nitrogen and nodulation treatment conditions, highlights the fact that plants of same PI value are at the same developmental state, irrespective of the growth condition. Furthermore, changes in plant structure and function observed under different growth conditions can be related simply to changes in plastochron index. The work presented in this thesis demonstrate that changes in plant structure and function analyzed are related to changes in PI. An important finding of this thesis is that with the use of PI, results can be compiled as a template for predicting the structure- function state of pea plants at any plastochron age, under any growth conditions, before using small representative sample populations.
- Full Text:
- Date Issued: 2006
- Authors: Ade-Ademilua, Omobolanle Elizabeth
- Date: 2006
- Subjects: Plant anatomy Plant physiology Peas -- Anatomy Peas -- Physiology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4183 , http://hdl.handle.net/10962/d1003751
- Description: The use of chronological age for example, using days after sowing (DAS), or days after germination (DAG) as a time variable may result in the inherent variability between plants resulting in differences which can be large enough to obscure subtle developmental trends that become evident among plants sown at the same time. An alternative to DAS or DAG is the plastochron index (PI), first used by Erickson and Michelini (1957) as a morphological time scale and numerical index; which to according to the authors suggested and represented a more accurate reflection of the developmental status of a plant. The research presented in this thesis was therefore aimed specifically at utilizing the index in qualitative and quantitative analyses, to confirm its usefulness in analyzing and predicting plant growth and development. Specifically this research focused on investigating various morphological and physiological events that together, hopefully, would serve as a template for the prediction of the growth, development and reactions of Pisum sativum L. to different growth conditions. In Chapter 3, the use of the average length of the first pair of leaflets on each node as a suitable parameter for calculating PI in P. sativum is suggested. The results presented in Chapter 3 suggest that plant age is best expressed using the plastochron index, as this reflects the time interval between the initiations of successive pairs of leaflets. This section of the research has been published as “Ade-Ademilua OE, Botha CEJ (2005) A re-evaluation of plastochron index in peas - a case for using leaflet length. South African Journal of Botany 71: 76-80”. The PI formula developed was subsequently used in this research to conduct qualitative and quantitative investigations of plant growth and development in which all data and observations were related directly to the plastochron index. In Chapter 4, the sink to source transition in Pisum sativum L. leaves at different plastochron ages in nodulating plants was investigated using the phloem-mobile fluorescent marker, 5,6-carboxyfluorescein (5,6-CF). The results demonstrated that young leaves remained strong sinks up until LPI 0, after which sink-source transition occurred up to LPI 1.8 and leaflets transitioned to strong source systems by LPI 2.0. A well-developed cross-connected phloem system between paired leaflets in peas, and the petiole and the stem vascular supply was observed. The data presented in the second part of Chapter 4 suggest that the phloem transport between leaflet pairs is independent of the sink/source state of the leaflets, or of movement along the source to sink gradient. The data support the presence of a modular transport system which may ensure re-allocation and balancing between leaflets of the same physiological age and photosynthetic and transport status, thereby load-balancing the local transport system, before exporting to other younger (sink) regions. The investigation of leaf development using the plastochron index (Chapter 5) revealed that the formation of air spaces in the palisade and spongy mesophyll, one of the preparatory events for transition from sink to source state in developing leaves, occurs between LPI 0 and LPI 1 in pea leaflets. Results of the anatomical and ultrastructural study related to PI are presented in Chapter 5. The density of wall ingrowths in transfer cells of minor veins increased with LPI and appeared to be associated with the probable transition to source state and the related potential increase in the production of assimilates for export. The onset of wall ingrowth development in leaflets at LPI 0 provided evidence that sink-to-source transition commences at LPI 0 in P. sativum. Presumably-functional plasmodesmata as well as a few mature sieve elements were evident in class IV veins in the apical region of young and older leaflets at LPI 0. The number of mature sieve elements per vein however, increased with increasing LPI. Most class V veins were still undergoing division at LPI 0 and their sieve elements did not show signs of maturity until LPI 1. The increase in the number of mature metaphloem sieve elements in young, supposedly importing tissue at LPI 0 to older, supposedly exporting tissues at LPI 2 is evidence of the association between phloem maturation and transition from importing to exporting status. In Chapter 6, I report on the effects of elevated CO[subscript 2] on the growth and leaf development of nodulating and non-nodulating Pisum sativum L var. Greenfeast grown under controlled environment of the same nitrogen (6mM) and nitrogen- free nutrient solution conditions. Shortterm exposure to elevated CO[subscript 2] induced rapid plant growth, irrespective of treatment. However, long-term elevated CO[subscript 2] treatment did not affect rate of leaf appearance (RLA) in nodulated plants, irrespective of mineral N supply but enhanced RLA in non- nodulating plants supplied with mineral N. Supplied N resulted in a significant increase in leaflet elongation rate (LfER) under both ambient and elevated CO[subscript 2], but LfER was not significantly affected by nodulation but was increased by high CO[subscript 2]. This suggested that the growth of nodulating P. sativum L may not be significantly affected under CO[subscript 2] levels as high as 1000 μmol mol[superscript -1]. The data suggest that elevated CO[subscript 2] will enhance canopy size, provided adequate soil N is available and more so in non-nodulating plants. This section of the research has been published as “Ade-Ademilua OE, Botha CEJ (2004) The effects of elevated CO[subscript 2] and nitrogen availability supersedes the need for nodulation in peas grown under controlled environmental conditions. South African Journal of Botany 70: 816 – 823”. This thesis demonstrates that the similarity in the qualitative analyses results obtained from plants from different CO[subscript 2], nitrogen and nodulation treatment conditions, highlights the fact that plants of same PI value are at the same developmental state, irrespective of the growth condition. Furthermore, changes in plant structure and function observed under different growth conditions can be related simply to changes in plastochron index. The work presented in this thesis demonstrate that changes in plant structure and function analyzed are related to changes in PI. An important finding of this thesis is that with the use of PI, results can be compiled as a template for predicting the structure- function state of pea plants at any plastochron age, under any growth conditions, before using small representative sample populations.
- Full Text:
- Date Issued: 2006
A re-evaluation of plastochron index determination in peas - a case for using leaflet length
- Ade-Ademilua, Omobolanle Elizabeth, Botha, Christiaan E J
- Authors: Ade-Ademilua, Omobolanle Elizabeth , Botha, Christiaan E J
- Date: 2005
- Language: English
- Type: Article
- Identifier: vital:6491 , http://hdl.handle.net/10962/d1004472
- Description: The plastochron index (PI) is a measure of plant growth reports our findings on PI using the average length of and can be used to determine growth rate, based upon the first pair of leaflets on each node. Early leaflet appearance of successive leaves on the axis of the growth in peas occurs exponentially and the early plant. PI should under ideal growth conditions be a stages of growth of successive pairs of leaflets occur at regular event and should be predictable with a relatively the same relative growth rate. Given that growth of small error of a few hours. PI has been variously leaflets during early development can be measured calculated in peas, and each method reported has had successfully, we propose the use of leaflet growth as a with it a number of problems that do not allow for measure of the plastochron index in peas. Our results reasonable prediction of PI. Internode length varies suggest that plant age is best expressed using the greatly and is dependent upon the variety, which may be plastochron index, which is a measure of the time short- or long-stemmed; thus this parameter is not ideal interval between the initiations of successive events — for determining growth rate or plant age. This paper in the case of peas, of successive pairs of leaflets.
- Full Text:
- Date Issued: 2005
- Authors: Ade-Ademilua, Omobolanle Elizabeth , Botha, Christiaan E J
- Date: 2005
- Language: English
- Type: Article
- Identifier: vital:6491 , http://hdl.handle.net/10962/d1004472
- Description: The plastochron index (PI) is a measure of plant growth reports our findings on PI using the average length of and can be used to determine growth rate, based upon the first pair of leaflets on each node. Early leaflet appearance of successive leaves on the axis of the growth in peas occurs exponentially and the early plant. PI should under ideal growth conditions be a stages of growth of successive pairs of leaflets occur at regular event and should be predictable with a relatively the same relative growth rate. Given that growth of small error of a few hours. PI has been variously leaflets during early development can be measured calculated in peas, and each method reported has had successfully, we propose the use of leaflet growth as a with it a number of problems that do not allow for measure of the plastochron index in peas. Our results reasonable prediction of PI. Internode length varies suggest that plant age is best expressed using the greatly and is dependent upon the variety, which may be plastochron index, which is a measure of the time short- or long-stemmed; thus this parameter is not ideal interval between the initiations of successive events — for determining growth rate or plant age. This paper in the case of peas, of successive pairs of leaflets.
- Full Text:
- Date Issued: 2005
What does the movement of the Phloem-mobile symplastic tracer, 5,6-carboxyfluorescein in shoots of Pisum Sativum L. Indicate - the existence of a symplastic transport system? - a bid to answer some puzzling questions
- Ade-Ademilua, Omobolanle Elizabeth, Botha, Christiaan E J
- Authors: Ade-Ademilua, Omobolanle Elizabeth , Botha, Christiaan E J
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6492 , http://hdl.handle.net/10962/d1004475 , http://dx.doi.org/10.3923/ajpp.2006.127.131
- Description: Like other members of the Fabaceae, the minor veins of Pisum are categorized as a closed system termed type 2 minor vein configuration due to the presence of few or no plasmodesmal connections between the sieve element-transfer cell complex (SE-TCC) and the adjacent cells (Gamalei, 1989; van Bel and Gamalei, 1991) Pisum is classified further into the category of type 2 b minor vein configuration due to the presence of transfer cells with the characteristic wall ingrowths in the minor vein phloem (Gamalei, 1989). According to van Bel et al. (1992), there is a correlation between minor vein configuration and phloem loading. However, by reason of low plasmodesmal frequency, the pathway of the flow of assimilates in plants with type 2 minor vein configuration is considered to be apoplasmic (Gamalei, 1989; van Bel and Gamalei, 1991). Therefore, present reports on the movement of phloem-mobile 5,6-carboxyfluorescein, a known symplamically transported compound between pea leaflets raises some doubts on the accession that transport within the phloem in pea is strictly apoplasmic. In this study we look at different points of arguments and try to offer our explanation and conclusions on the transport pathways that are likely to exist in Pisum.
- Full Text: false
- Date Issued: 2006
- Authors: Ade-Ademilua, Omobolanle Elizabeth , Botha, Christiaan E J
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6492 , http://hdl.handle.net/10962/d1004475 , http://dx.doi.org/10.3923/ajpp.2006.127.131
- Description: Like other members of the Fabaceae, the minor veins of Pisum are categorized as a closed system termed type 2 minor vein configuration due to the presence of few or no plasmodesmal connections between the sieve element-transfer cell complex (SE-TCC) and the adjacent cells (Gamalei, 1989; van Bel and Gamalei, 1991) Pisum is classified further into the category of type 2 b minor vein configuration due to the presence of transfer cells with the characteristic wall ingrowths in the minor vein phloem (Gamalei, 1989). According to van Bel et al. (1992), there is a correlation between minor vein configuration and phloem loading. However, by reason of low plasmodesmal frequency, the pathway of the flow of assimilates in plants with type 2 minor vein configuration is considered to be apoplasmic (Gamalei, 1989; van Bel and Gamalei, 1991). Therefore, present reports on the movement of phloem-mobile 5,6-carboxyfluorescein, a known symplamically transported compound between pea leaflets raises some doubts on the accession that transport within the phloem in pea is strictly apoplasmic. In this study we look at different points of arguments and try to offer our explanation and conclusions on the transport pathways that are likely to exist in Pisum.
- Full Text: false
- Date Issued: 2006
Synthesis, spectroscopic and electrochemical properties of manganese, nickel and iron octakis-(2-diethylaminoethanethiol)-phthalocyanine
- Adebayo, A I, Nyokong, Tebello
- Authors: Adebayo, A I , Nyokong, Tebello
- Date: 2009
- Language: English
- Type: Article
- Identifier: vital:6563 , http://hdl.handle.net/10962/d1004122
- Description: The syntheses, spectroscopic and electrochemical properties of manganese (3), nickel (4) and iron (5) phthalocyanine complexes, octa-substituted at the peripheral positions with diethlyaminoethanethiol substituent, are reported. The electrochemistry of these complexes and the corresponding cobalt complex (6) are reported. Complex 3 showed two reversible reduction couples attributed to the MnIIIPc−2/MnIIPc−2 (E½ = −0.12 V versus Ag|AgCl) and MnIIPc−2/MnIIPc−3 (E½ = −0.82 V versus Ag|AgCl) species. Two ring-based reduction couples were also observed for complex 4. Two reduction couples, assigned to the FeIIPc−2/FeIPc−2 (E½ = −0.35 V versus Ag|AgCl) and FeIPc−2/FeIPc−3 (E½ = −0.96 V versus Ag|AgCl) species, and an oxidation couple, attributed to FeIIIPc−2/FeIIPc−2 (E½ = 0.26 V versus Ag|AgCl) species, were observed. For complex 6, two reductions and one oxidation were also observed with the potential range of 1.2 to −1.8 V versus Ag|AgCl Spectroelectrochemical studies were used to confirm some of the assigned processes.
- Full Text:
- Date Issued: 2009
- Authors: Adebayo, A I , Nyokong, Tebello
- Date: 2009
- Language: English
- Type: Article
- Identifier: vital:6563 , http://hdl.handle.net/10962/d1004122
- Description: The syntheses, spectroscopic and electrochemical properties of manganese (3), nickel (4) and iron (5) phthalocyanine complexes, octa-substituted at the peripheral positions with diethlyaminoethanethiol substituent, are reported. The electrochemistry of these complexes and the corresponding cobalt complex (6) are reported. Complex 3 showed two reversible reduction couples attributed to the MnIIIPc−2/MnIIPc−2 (E½ = −0.12 V versus Ag|AgCl) and MnIIPc−2/MnIIPc−3 (E½ = −0.82 V versus Ag|AgCl) species. Two ring-based reduction couples were also observed for complex 4. Two reduction couples, assigned to the FeIIPc−2/FeIPc−2 (E½ = −0.35 V versus Ag|AgCl) and FeIPc−2/FeIPc−3 (E½ = −0.96 V versus Ag|AgCl) species, and an oxidation couple, attributed to FeIIIPc−2/FeIIPc−2 (E½ = 0.26 V versus Ag|AgCl) species, were observed. For complex 6, two reductions and one oxidation were also observed with the potential range of 1.2 to −1.8 V versus Ag|AgCl Spectroelectrochemical studies were used to confirm some of the assigned processes.
- Full Text:
- Date Issued: 2009