‘They do not understand us’: a psychosocial analysis of the everyday lived experiences of a CYCC care worker in semi-rural South Africa
- Authors: Pieters, Cinnamon-Paige
- Date: 2022-04-07
- Subjects: Child care workers South Africa Attitudes , Narrative inquiry (Research method) , Intersubjectivity , Free association (Psychology) , Child care South Africa Psychological aspects , Burn out (Psychology) South Africa
- Language: English
- Type: Article , text
- Identifier: http://hdl.handle.net/10962/294482 , vital:57225
- Description: This paper employs a psychosocial framework to analyse the everyday lived experiences of a child and youth care worker in semi-rural South Africa. The aim is to provide a new perspective of care work by drawing on narrative analysis alongside a psychoanalytic approach to qualitative research. With an emphasis on the socially constructed nature of reality, the researcher aims to elucidate the rich unconscious depths of being a care worker and the dynamics of the intersubjective reality of care work. Employing a free association narrative interview technique allows the researcher to gain understanding of the narratives that the care worker draws on in the construction of his identity as a care worker. The use of a psychosocial approach enables the researcher to pay attention to both the social context that influences the narratives that he draws on, but also the psychological ‘pay offs’ of these constructions. Most notably, the study highlights how the care worker’s identity is mediated by a defended subjectivity and argues that his failures in mentalization might stem from the way he is treated as a care worker by other professionals as a result of their mindblindness. This maintains his narrative of invisibility, and the pervasive feeling of being misunderstood as a professional in his own right. The findings are discussed in terms of their contribution to understanding some of the challenges that CYCC care workers face. , Research Article (MA) -- Faculty of Humanities, Psychology, 2022
- Full Text:
- Date Issued: 2022-04-07
- Authors: Pieters, Cinnamon-Paige
- Date: 2022-04-07
- Subjects: Child care workers South Africa Attitudes , Narrative inquiry (Research method) , Intersubjectivity , Free association (Psychology) , Child care South Africa Psychological aspects , Burn out (Psychology) South Africa
- Language: English
- Type: Article , text
- Identifier: http://hdl.handle.net/10962/294482 , vital:57225
- Description: This paper employs a psychosocial framework to analyse the everyday lived experiences of a child and youth care worker in semi-rural South Africa. The aim is to provide a new perspective of care work by drawing on narrative analysis alongside a psychoanalytic approach to qualitative research. With an emphasis on the socially constructed nature of reality, the researcher aims to elucidate the rich unconscious depths of being a care worker and the dynamics of the intersubjective reality of care work. Employing a free association narrative interview technique allows the researcher to gain understanding of the narratives that the care worker draws on in the construction of his identity as a care worker. The use of a psychosocial approach enables the researcher to pay attention to both the social context that influences the narratives that he draws on, but also the psychological ‘pay offs’ of these constructions. Most notably, the study highlights how the care worker’s identity is mediated by a defended subjectivity and argues that his failures in mentalization might stem from the way he is treated as a care worker by other professionals as a result of their mindblindness. This maintains his narrative of invisibility, and the pervasive feeling of being misunderstood as a professional in his own right. The findings are discussed in terms of their contribution to understanding some of the challenges that CYCC care workers face. , Research Article (MA) -- Faculty of Humanities, Psychology, 2022
- Full Text:
- Date Issued: 2022-04-07
Monitoring and Management Mechanisms on Stress in HEI in Eastern Cape Province in South Africa: Critical Review
- Asoba, Samson Nambei, Patricia, Nteboheng Mefi
- Authors: Asoba, Samson Nambei , Patricia, Nteboheng Mefi
- Date: 2021
- Subjects: Teachers--Job stress , Ill-Discipline of Learners , Middle school education -- Parent participation
- Language: English
- Type: text , article , Article
- Identifier: http://hdl.handle.net/11260/8068 , vital:61393 , xlink:href="https://www.abacademies.org/articles/monitoring-and-management-mechanisms-on-stress-in-hei-in-eastern-cape-province-in-south-africa-critical-review-10636.html"
- Description: Stress is a global phenomenon that affects everyone regardless of gender, resources and environment. Although this phenomenon is well researched, teachers’ experiences of stress remains a worrying challenge particularly to schools’ effectiveness. This study sought to establish how monitoring and management mechanism that can assist teachers to cope with stress challenges. These are some of the recommendation: that the school disciplinary committee should be trained in various disciplinary measures that may be implemented in the school to curb learner ill-discipline and lack of commitment, that working relationship should be built between schools and the Department of Basic Education, motivational speakers and educational counsellors should meet with all learners on a regular basis to motivate them to have high desire for and interest in education and to build their self-confidence in the classroom, providing all the schools with healthy environment in classrooms, provision of learning and teaching materials to all schools, schools should set up an effective school-parents partnership in order to promote a safe drug and alcohol free environment, employ enough teachers in all secondary schools and the Department of Basic Education at district level should make room for stress management workshops for teachers.
- Full Text:
- Date Issued: 2021
- Authors: Asoba, Samson Nambei , Patricia, Nteboheng Mefi
- Date: 2021
- Subjects: Teachers--Job stress , Ill-Discipline of Learners , Middle school education -- Parent participation
- Language: English
- Type: text , article , Article
- Identifier: http://hdl.handle.net/11260/8068 , vital:61393 , xlink:href="https://www.abacademies.org/articles/monitoring-and-management-mechanisms-on-stress-in-hei-in-eastern-cape-province-in-south-africa-critical-review-10636.html"
- Description: Stress is a global phenomenon that affects everyone regardless of gender, resources and environment. Although this phenomenon is well researched, teachers’ experiences of stress remains a worrying challenge particularly to schools’ effectiveness. This study sought to establish how monitoring and management mechanism that can assist teachers to cope with stress challenges. These are some of the recommendation: that the school disciplinary committee should be trained in various disciplinary measures that may be implemented in the school to curb learner ill-discipline and lack of commitment, that working relationship should be built between schools and the Department of Basic Education, motivational speakers and educational counsellors should meet with all learners on a regular basis to motivate them to have high desire for and interest in education and to build their self-confidence in the classroom, providing all the schools with healthy environment in classrooms, provision of learning and teaching materials to all schools, schools should set up an effective school-parents partnership in order to promote a safe drug and alcohol free environment, employ enough teachers in all secondary schools and the Department of Basic Education at district level should make room for stress management workshops for teachers.
- Full Text:
- Date Issued: 2021
Retracted COVID-19 Papers and the level of 'citation pollution': a preliminary analysis and directions for future research
- Van der Walt, Wynand, Willems, Kris A, Friedrich, Wernher, Hatsu, Sylvester, Krauss, Kirstin
- Authors: Van der Walt, Wynand , Willems, Kris A , Friedrich, Wernher , Hatsu, Sylvester , Krauss, Kirstin
- Date: 2020
- Subjects: Retraction watch , Research -- Evaluation , Bibliographical citations -- Evaluation , Science publishing -- Corrupt practices , Scholarly publishing -- Corrupt practices , Learning and scholarship -- Corrupt practices , Medical publishing -- Corrupt practices , COVID-19 (Disease) -- Publishing
- Language: English
- Type: Article , text
- Identifier: http://hdl.handle.net/10962/167732 , vital:41508 , https://www.abd-bvd.be/nl/bladen-voor-documentatie/2020-3-4/
- Description: Retraction Watch maintains a "running list" of retracted papers on Covid-19 related research. By the end of September 2020, thirty-three retracted Covid-19 papers were listed. We analysed these retracted papers, focusing specifically on how they have been cited by review papers, and subsequently how they have penetrated and potentially distorted public discourse and legitimate research on Covid-19. The study demonstrates the need for more in-depth studies that focus on the phenomenon of citation pollution. We show that the "Covid-19 publication race", amplified by a pressure-to-publish research culture, distorted published science on Covid-19. We highlight the urgency to engage popular media and critical decision makers on how to distinguish between questionable and legitimate science. We also emphasise the importance of dealing with illegitimate research in a timely manner, both from a scholarly communications and research quality perspective. , Retraction Watch maintient une "liste courante" des articles rétractés sur les recherches liées au Covid-19. Fin septembre 2020, trente-trois articles rétractés sur le Covid-19 étaient répertoriés. Nous avons analysé ces articles rétractés, en nous concentrant spécifiquement sur la façon dont ils ont été cités par d'autres articles, et ensuite sur la façon dont ils ont pénétré et potentiellement faussé le discours public et la recherche légitime sur le Covid-19. L'étude démontre le besoin d'études plus approfondies qui se concentrent sur le phénomène de la pollution des citations. Nous montrons que la "course à la publication sur le Covid-19", amplifiée par une culture de la pression à la publication de la recherche, a déformé l'information scientifique publiée sur le Covid-19. Nous soulignons l'urgence d'engager les médias populaires et les décideurs critiques sur la manière de distinguer la science douteuse de la science légitime. Nous soulignons également l'importance de traiter rapidement les recherches illégitimes, tant du point de vue de la communication scientifique que de la qualité de la recherche. , Retraction Watch houdt een "lopende lijst" bij van ingetrokken papieren over Covid-19-gerelateerd onderzoek. Eind september 2020 waren drieëndertig ingetrokken Covid-19 papieren op de lijst geplaatst. We hebben deze ingetrokken papieren geanalyseerd, waarbij we ons specifiek hebben gericht op de manier waarop ze zijn geciteerd door review papers, en vervolgens op de manier waarop ze zijn doorgedrongen en mogelijk vervormd in het publieke discours en het legitieme onderzoek naar Covid-19. De studie toont aan dat er behoefte is aan meer diepgaande studies die zich richten op het fenomeen van de citatievervuiling. We tonen aan dat de "Covid-19-publicatierace", versterkt door een druk om te publiceren onderzoekscultuur, de gepubliceerde wetenschap over Covid-19 vertekend heeft. We benadrukken de urgentie om de populaire media en kritische besluitvormers te betrekken bij het maken van een onderscheid tussen twijfelachtige en legitieme wetenschap. We benadrukken ook het belang van het tijdig aanpakken van onrechtmatig onderzoek, zowel vanuit het oogpunt van wetenschappelijke communicatie als vanuit het oogpunt van de kwaliteit van het onderzoek.
- Full Text:
- Date Issued: 2020
- Authors: Van der Walt, Wynand , Willems, Kris A , Friedrich, Wernher , Hatsu, Sylvester , Krauss, Kirstin
- Date: 2020
- Subjects: Retraction watch , Research -- Evaluation , Bibliographical citations -- Evaluation , Science publishing -- Corrupt practices , Scholarly publishing -- Corrupt practices , Learning and scholarship -- Corrupt practices , Medical publishing -- Corrupt practices , COVID-19 (Disease) -- Publishing
- Language: English
- Type: Article , text
- Identifier: http://hdl.handle.net/10962/167732 , vital:41508 , https://www.abd-bvd.be/nl/bladen-voor-documentatie/2020-3-4/
- Description: Retraction Watch maintains a "running list" of retracted papers on Covid-19 related research. By the end of September 2020, thirty-three retracted Covid-19 papers were listed. We analysed these retracted papers, focusing specifically on how they have been cited by review papers, and subsequently how they have penetrated and potentially distorted public discourse and legitimate research on Covid-19. The study demonstrates the need for more in-depth studies that focus on the phenomenon of citation pollution. We show that the "Covid-19 publication race", amplified by a pressure-to-publish research culture, distorted published science on Covid-19. We highlight the urgency to engage popular media and critical decision makers on how to distinguish between questionable and legitimate science. We also emphasise the importance of dealing with illegitimate research in a timely manner, both from a scholarly communications and research quality perspective. , Retraction Watch maintient une "liste courante" des articles rétractés sur les recherches liées au Covid-19. Fin septembre 2020, trente-trois articles rétractés sur le Covid-19 étaient répertoriés. Nous avons analysé ces articles rétractés, en nous concentrant spécifiquement sur la façon dont ils ont été cités par d'autres articles, et ensuite sur la façon dont ils ont pénétré et potentiellement faussé le discours public et la recherche légitime sur le Covid-19. L'étude démontre le besoin d'études plus approfondies qui se concentrent sur le phénomène de la pollution des citations. Nous montrons que la "course à la publication sur le Covid-19", amplifiée par une culture de la pression à la publication de la recherche, a déformé l'information scientifique publiée sur le Covid-19. Nous soulignons l'urgence d'engager les médias populaires et les décideurs critiques sur la manière de distinguer la science douteuse de la science légitime. Nous soulignons également l'importance de traiter rapidement les recherches illégitimes, tant du point de vue de la communication scientifique que de la qualité de la recherche. , Retraction Watch houdt een "lopende lijst" bij van ingetrokken papieren over Covid-19-gerelateerd onderzoek. Eind september 2020 waren drieëndertig ingetrokken Covid-19 papieren op de lijst geplaatst. We hebben deze ingetrokken papieren geanalyseerd, waarbij we ons specifiek hebben gericht op de manier waarop ze zijn geciteerd door review papers, en vervolgens op de manier waarop ze zijn doorgedrongen en mogelijk vervormd in het publieke discours en het legitieme onderzoek naar Covid-19. De studie toont aan dat er behoefte is aan meer diepgaande studies die zich richten op het fenomeen van de citatievervuiling. We tonen aan dat de "Covid-19-publicatierace", versterkt door een druk om te publiceren onderzoekscultuur, de gepubliceerde wetenschap over Covid-19 vertekend heeft. We benadrukken de urgentie om de populaire media en kritische besluitvormers te betrekken bij het maken van een onderscheid tussen twijfelachtige en legitieme wetenschap. We benadrukken ook het belang van het tijdig aanpakken van onrechtmatig onderzoek, zowel vanuit het oogpunt van wetenschappelijke communicatie als vanuit het oogpunt van de kwaliteit van het onderzoek.
- Full Text:
- Date Issued: 2020
Lipophilic M(α,α′-OC5H11)8phthalocyanines (M = H2 and Ni(II)): synthesis, electronic structure, and their utility for highly efficient carbonyl reductions
- Jiang, Yu, Li, Minzhi, Liang, Xu, Mack, John, Wildervanck, Martijn, Nyokong, Tebello, Qin, Mingfeng, Zhu, Weihua
- Authors: Jiang, Yu , Li, Minzhi , Liang, Xu , Mack, John , Wildervanck, Martijn , Nyokong, Tebello , Qin, Mingfeng , Zhu, Weihua
- Date: 2015-10-07
- Subjects: Dalton Transactions (2015), 44, 18237-18246, doi:10.1039/c5dt03256c
- Language: English
- Type: Article
- Identifier: vital:7282 , http://hdl.handle.net/10962/d1020322
- Description: A lipophilic and electron-rich phthalocyanine (α,α′-n-OC5H11)8-H2Pc and its nickel(II) complex (α,α′-n-OC5H11)8-Ni(II)Pc have been synthesized and characterized. Detailed analyses of the electronic structure were carried out by spectroscopy, electrochemistry, spectroelectrochemistry, and TD-DFT calculations. A series of experiments demonstrate that the (α,α′-n-OC5H11)8-Ni(II)Pc complex can be used as a catalyst for highly efficient carbonyl reductions. , Original publication is available at http://dx.doi.org/10.1039/C5DT03256C
- Full Text:
- Authors: Jiang, Yu , Li, Minzhi , Liang, Xu , Mack, John , Wildervanck, Martijn , Nyokong, Tebello , Qin, Mingfeng , Zhu, Weihua
- Date: 2015-10-07
- Subjects: Dalton Transactions (2015), 44, 18237-18246, doi:10.1039/c5dt03256c
- Language: English
- Type: Article
- Identifier: vital:7282 , http://hdl.handle.net/10962/d1020322
- Description: A lipophilic and electron-rich phthalocyanine (α,α′-n-OC5H11)8-H2Pc and its nickel(II) complex (α,α′-n-OC5H11)8-Ni(II)Pc have been synthesized and characterized. Detailed analyses of the electronic structure were carried out by spectroscopy, electrochemistry, spectroelectrochemistry, and TD-DFT calculations. A series of experiments demonstrate that the (α,α′-n-OC5H11)8-Ni(II)Pc complex can be used as a catalyst for highly efficient carbonyl reductions. , Original publication is available at http://dx.doi.org/10.1039/C5DT03256C
- Full Text:
A discourse of disconnect : young people from the Eastern Cape talk about the failure of adult communications to provide habitable sexual subject positions
- Jearey-Graham, Nicola, Macleod, Catriona I
- Authors: Jearey-Graham, Nicola , Macleod, Catriona I
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:6308 , http://hdl.handle.net/10962/d1018864 , http://0-hdl.handle.net.wam.seals.ac.za/10520/EJC171669
- Description: Face-to-face adult communication with young people about sexuality is, for the most part, assigned to two main groups of people: educators tasked with teaching schoolbased sexuality education that is provided as part of the compulsory Life Orientation (LO) learning area, and parents. In this paper, we report on a study conducted with Further Education and Training College students in an Eastern Cape town. Using a discursive psychology lens, we analysed data from, first, a written question on what participants remember being taught about sexuality in LO classes and, second, focus group discussions held with mixed and same-sex groups. Discussions were structured around the sexualities of high school learners and the LO sexuality education that participants received at high school. We highlight participants’ common deployment of a ‘discourse of disconnect’ in their talk. In this discourse, the messages of ‘risk’ and ‘responsibility’ contained in adult face-to-face communications, by both parents and LO teachers, are depicted as being delivered through inadequate or nonrelational styles of communication, and as largely irrelevant to participants’ lives. Neither of these sources of communication was seen as understanding the realities of youth sexualities or as creating habitable or performable sexual subject positions. The dominance of this ‘discourse of disconnect’ has implications for how sexuality education and parent communication interventions are conducted.
- Full Text:
- Date Issued: 2015
- Authors: Jearey-Graham, Nicola , Macleod, Catriona I
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:6308 , http://hdl.handle.net/10962/d1018864 , http://0-hdl.handle.net.wam.seals.ac.za/10520/EJC171669
- Description: Face-to-face adult communication with young people about sexuality is, for the most part, assigned to two main groups of people: educators tasked with teaching schoolbased sexuality education that is provided as part of the compulsory Life Orientation (LO) learning area, and parents. In this paper, we report on a study conducted with Further Education and Training College students in an Eastern Cape town. Using a discursive psychology lens, we analysed data from, first, a written question on what participants remember being taught about sexuality in LO classes and, second, focus group discussions held with mixed and same-sex groups. Discussions were structured around the sexualities of high school learners and the LO sexuality education that participants received at high school. We highlight participants’ common deployment of a ‘discourse of disconnect’ in their talk. In this discourse, the messages of ‘risk’ and ‘responsibility’ contained in adult face-to-face communications, by both parents and LO teachers, are depicted as being delivered through inadequate or nonrelational styles of communication, and as largely irrelevant to participants’ lives. Neither of these sources of communication was seen as understanding the realities of youth sexualities or as creating habitable or performable sexual subject positions. The dominance of this ‘discourse of disconnect’ has implications for how sexuality education and parent communication interventions are conducted.
- Full Text:
- Date Issued: 2015
Anton and Vale van der Merwe: reinterpreting Afro-Oriental studio ceramics traditions in South Africa
- Authors: Steele, John
- Date: 2015
- Language: English
- Type: text , Article
- Identifier: http://hdl.handle.net/11260/968 , vital:30077
- Description: Growing awareness of ancient Chinese Song and Yuan ceramics, amongst other Oriental traditions, by people with western connections such as Bernard Leach and Michael Cardew, in conjunction with influences from Japanese associates such as Soyetsu Yanagi, Kenkichi Tomimoto, and Shoji Hamada, (De Waal 1997, Harrod 2012, Kikuchi 1977, Leach 1976) has had many consequences. It spread a consciousness idealizing self-sufficient pottery studios where potters were in touch with all aspects of creating utilityware, largely from local materials for local use. Out of this emerged an Anglo-Oriental studio ceramic philosophy of form and practice, associated mainly with hand-made high temperature reduction fired ceramics. These ideas spread to South Africa in the late 1950s, and by the early 1960s local studios were being established along these lines. This studio ceramics movement grew exponentially in South Africa, initiating a phase of Afro-Oriental ceramics that remains a powerful way of life and visual arts influence. This paper seeks to explore aspects of Afro- Oriental studio ceramics in South Africa, with particular reference to the Leach/Hamada/Cardew to Rabinowitz, and Van der Merwe lineage.
- Full Text:
- Date Issued: 2015
- Authors: Steele, John
- Date: 2015
- Language: English
- Type: text , Article
- Identifier: http://hdl.handle.net/11260/968 , vital:30077
- Description: Growing awareness of ancient Chinese Song and Yuan ceramics, amongst other Oriental traditions, by people with western connections such as Bernard Leach and Michael Cardew, in conjunction with influences from Japanese associates such as Soyetsu Yanagi, Kenkichi Tomimoto, and Shoji Hamada, (De Waal 1997, Harrod 2012, Kikuchi 1977, Leach 1976) has had many consequences. It spread a consciousness idealizing self-sufficient pottery studios where potters were in touch with all aspects of creating utilityware, largely from local materials for local use. Out of this emerged an Anglo-Oriental studio ceramic philosophy of form and practice, associated mainly with hand-made high temperature reduction fired ceramics. These ideas spread to South Africa in the late 1950s, and by the early 1960s local studios were being established along these lines. This studio ceramics movement grew exponentially in South Africa, initiating a phase of Afro-Oriental ceramics that remains a powerful way of life and visual arts influence. This paper seeks to explore aspects of Afro- Oriental studio ceramics in South Africa, with particular reference to the Leach/Hamada/Cardew to Rabinowitz, and Van der Merwe lineage.
- Full Text:
- Date Issued: 2015
Applications of social media and web 2.0 for research support in selected African academic institutions
- Owusu-Ansah, Christopher M, Gontshi, Vuyokazi, Mutibwa, Lois, Ukwoma, Scholarstica
- Authors: Owusu-Ansah, Christopher M , Gontshi, Vuyokazi , Mutibwa, Lois , Ukwoma, Scholarstica
- Date: 2015
- Subjects: Social networks , Web 2.0. , Research -- Study and teaching
- Language: English
- Type: Article
- Identifier: vital:6996 , http://hdl.handle.net/10962/d1018520
- Description: This study examined the use of Social Media/Web 2.0 for research support and it is guided by three objectives namely: a) to ascertain the uses of social media in academic institutions; b) to identify the challenges associated with social media use for research purposes and c) to provide experiences of social media application in selected African academic institutions. The study makes use of literature analysis in combination with personal and professional work experiences on the use of social media from librarians in four different countries. Institutional experiences of the four librarians showed that it is only Rhodes University Library that uses social media in its library, which is as a result of a formal social media strategy. For the other three universities, University of Education, Winneba Library in Ghana, Makerere University Library in Uganda and the University of Nigeria Library, the use of social media is not encouraging. They use it mostly for communication and interaction with colleagues. It was also discovered that there is no social media strategy available in these university libraries. Based on these findings, the study recommended the implementation of a social media strategy, appointment of social media librarians in these libraries, and continuing professional development of librarians to keep abreast with current trends. Web 2.0/Social Media is a new technology offering new options for African academic librarians in their research support role
- Full Text:
- Date Issued: 2015
- Authors: Owusu-Ansah, Christopher M , Gontshi, Vuyokazi , Mutibwa, Lois , Ukwoma, Scholarstica
- Date: 2015
- Subjects: Social networks , Web 2.0. , Research -- Study and teaching
- Language: English
- Type: Article
- Identifier: vital:6996 , http://hdl.handle.net/10962/d1018520
- Description: This study examined the use of Social Media/Web 2.0 for research support and it is guided by three objectives namely: a) to ascertain the uses of social media in academic institutions; b) to identify the challenges associated with social media use for research purposes and c) to provide experiences of social media application in selected African academic institutions. The study makes use of literature analysis in combination with personal and professional work experiences on the use of social media from librarians in four different countries. Institutional experiences of the four librarians showed that it is only Rhodes University Library that uses social media in its library, which is as a result of a formal social media strategy. For the other three universities, University of Education, Winneba Library in Ghana, Makerere University Library in Uganda and the University of Nigeria Library, the use of social media is not encouraging. They use it mostly for communication and interaction with colleagues. It was also discovered that there is no social media strategy available in these university libraries. Based on these findings, the study recommended the implementation of a social media strategy, appointment of social media librarians in these libraries, and continuing professional development of librarians to keep abreast with current trends. Web 2.0/Social Media is a new technology offering new options for African academic librarians in their research support role
- Full Text:
- Date Issued: 2015
Celebrating libraries in 20 years of democracy : an overview of library and information services in South Africa
- Authors: Satgoor, Ujala
- Date: 2015
- Subjects: Libraries , Library administration -- South Africa , Information services -- South Africa , Public libraries -- South Africa , Library science -- South Africa
- Language: English
- Type: Article
- Identifier: vital:6997 , http://hdl.handle.net/10962/d1019841 , ISSN ISSN: 0340-0352 , http://journals.sagepub.com/doi/10.1177/0340035215585100
- Description: Since the establishment of the first public library in 1818, the South African library and information services landscape has also been a reflection of the socio-political order and developments in the country. This article presents an historical perspective as well as an overview of libraries in South Africa since 1994, the context within which libraries function, library governance and legislative framework, government funding for redress, library technologies, library and information services education and the professional association. The article further highlights the importance of libraries in meeting the goals of the national development agenda towards entrenching a strong democracy and an educated and informed nation , Original publication is available at: http://dx.doi.org/10.1177/0340035215585100
- Full Text:
- Date Issued: 2015
- Authors: Satgoor, Ujala
- Date: 2015
- Subjects: Libraries , Library administration -- South Africa , Information services -- South Africa , Public libraries -- South Africa , Library science -- South Africa
- Language: English
- Type: Article
- Identifier: vital:6997 , http://hdl.handle.net/10962/d1019841 , ISSN ISSN: 0340-0352 , http://journals.sagepub.com/doi/10.1177/0340035215585100
- Description: Since the establishment of the first public library in 1818, the South African library and information services landscape has also been a reflection of the socio-political order and developments in the country. This article presents an historical perspective as well as an overview of libraries in South Africa since 1994, the context within which libraries function, library governance and legislative framework, government funding for redress, library technologies, library and information services education and the professional association. The article further highlights the importance of libraries in meeting the goals of the national development agenda towards entrenching a strong democracy and an educated and informed nation , Original publication is available at: http://dx.doi.org/10.1177/0340035215585100
- Full Text:
- Date Issued: 2015
Comparative photophysicochemical behavior of nanoconjugates of indium tetracarboxyphenoxy phthalocyanines covalently linked to CdTe/ZnSe/ZnO quantum dots
- Oluwole, David O, Nyokong, Tebello
- Authors: Oluwole, David O , Nyokong, Tebello
- Date: 2015
- Language: English
- Type: text , Article
- Identifier: vital:7294 , http://hdl.handle.net/10962/d1020357 , http://dx.doi.org/10.1016/j.jphotochem.2015.07.009
- Description: This work reports on the photophysicochemical behavior of different nanoconjugates of core/shell/shell (GSH-CdTe/ZnSe/ZnO), core/shell (GSH-CdTe/ZnSe) and core (GSH-CdTe) (quantum dots QDs) with indium tetracarboxyphenoxy phthalocyanines ((OH)InTCPPc) in dimethylsulfoxide. The fluorescence quantum yields (Φf) and lifetimes (τf, in brackets) of QDs ranged from 0.20 (13.9 ns) to 0.42 (25.6 ns). The highest Φf value was obtained for GSH-CdTe/ZnSe/ZnO (4.5) while the least was observed in GSH-CdTe/ZnSe/ZnO (7.6), the numbers in brackets refer to the sizes. For (OH)InTCPPc alone a Φf and τf values of 0.02 and 2.43 ns, respectively were obtained. In the nanoconjugates, pivotal decrease in the Φf and τf of the QDs were observed with increase in the triplet and singlet oxygen quantum yields of (OH)InTCPPc. , Original publication is available at http://dx.doi.org/10.1016/j.jphotochem.2015.07.009
- Full Text: false
- Date Issued: 2015
- Authors: Oluwole, David O , Nyokong, Tebello
- Date: 2015
- Language: English
- Type: text , Article
- Identifier: vital:7294 , http://hdl.handle.net/10962/d1020357 , http://dx.doi.org/10.1016/j.jphotochem.2015.07.009
- Description: This work reports on the photophysicochemical behavior of different nanoconjugates of core/shell/shell (GSH-CdTe/ZnSe/ZnO), core/shell (GSH-CdTe/ZnSe) and core (GSH-CdTe) (quantum dots QDs) with indium tetracarboxyphenoxy phthalocyanines ((OH)InTCPPc) in dimethylsulfoxide. The fluorescence quantum yields (Φf) and lifetimes (τf, in brackets) of QDs ranged from 0.20 (13.9 ns) to 0.42 (25.6 ns). The highest Φf value was obtained for GSH-CdTe/ZnSe/ZnO (4.5) while the least was observed in GSH-CdTe/ZnSe/ZnO (7.6), the numbers in brackets refer to the sizes. For (OH)InTCPPc alone a Φf and τf values of 0.02 and 2.43 ns, respectively were obtained. In the nanoconjugates, pivotal decrease in the Φf and τf of the QDs were observed with increase in the triplet and singlet oxygen quantum yields of (OH)InTCPPc. , Original publication is available at http://dx.doi.org/10.1016/j.jphotochem.2015.07.009
- Full Text: false
- Date Issued: 2015
Deconstructing developmental psychology twenty years on : reflections, implications and empirical work
- Callaghan, Jane, Andenæs, Agnes, Macleod, Catriona I
- Authors: Callaghan, Jane , Andenæs, Agnes , Macleod, Catriona I
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:6315 , http://hdl.handle.net/10962/d1020934 , http://journals.sagepub.com/doi/abs/10.1177/0959353515583702
- Description: Editorial
- Full Text:
- Date Issued: 2015
- Authors: Callaghan, Jane , Andenæs, Agnes , Macleod, Catriona I
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:6315 , http://hdl.handle.net/10962/d1020934 , http://journals.sagepub.com/doi/abs/10.1177/0959353515583702
- Description: Editorial
- Full Text:
- Date Issued: 2015
Deposition of CdS, CdS/ZnSe and CdS/ZnSe/ZnS shells around CdSeTe alloyed core quantum dots: effects on optical properties
- Adegoke, Oluwasesan, Nyokong, Tebello, Forbes, Patricia B C
- Authors: Adegoke, Oluwasesan , Nyokong, Tebello , Forbes, Patricia B C
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:7289 , http://hdl.handle.net/10962/d1020342
- Description: In this work, we synthesized water-soluble L-cysteine-capped alloyed CdSeTe core quantum dots (QDs) and investigated the structural and optical properties of deposition of each of CdS, CdS/ZnSe and CdS/ZnSe/ZnS shell layers. Photophysical results showed that the overcoating of a CdS shell around the alloyed CdSeTe core [quantum yield (QY) = 8.4%] resulted in effective confinement of the radiative exciton with an improved QY value of 93.5%. Subsequent deposition of a ZnSe shell around the CdSeTe/CdS surface decreased the QY value to 24.7%, but an increase in the QY value of up to 49.5% was observed when a ZnS shell was overcoated around the CdSeTe/CdS/ZnSe surface. QDs with shell layers showed improved stability relative to the core. Data obtained from time-resolved fluorescence measurements provided useful insight into variations in the photophysical properties of the QDs upon the formation of each shell layer. Our study suggests that the formation of CdSeTe/CdS core/shell QDs meets the requirements of quality QDs in terms of high photoluminescence QY and stability, hence further deposition of additional shells are not necessary in improving the optical properties of the core/shell QDs. Copyright © 2015 John Wiley & Sons, Ltd. , Original publication is available at http://dx.doi.org/10.1002/bio.3013
- Full Text: false
- Date Issued: 2015
- Authors: Adegoke, Oluwasesan , Nyokong, Tebello , Forbes, Patricia B C
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:7289 , http://hdl.handle.net/10962/d1020342
- Description: In this work, we synthesized water-soluble L-cysteine-capped alloyed CdSeTe core quantum dots (QDs) and investigated the structural and optical properties of deposition of each of CdS, CdS/ZnSe and CdS/ZnSe/ZnS shell layers. Photophysical results showed that the overcoating of a CdS shell around the alloyed CdSeTe core [quantum yield (QY) = 8.4%] resulted in effective confinement of the radiative exciton with an improved QY value of 93.5%. Subsequent deposition of a ZnSe shell around the CdSeTe/CdS surface decreased the QY value to 24.7%, but an increase in the QY value of up to 49.5% was observed when a ZnS shell was overcoated around the CdSeTe/CdS/ZnSe surface. QDs with shell layers showed improved stability relative to the core. Data obtained from time-resolved fluorescence measurements provided useful insight into variations in the photophysical properties of the QDs upon the formation of each shell layer. Our study suggests that the formation of CdSeTe/CdS core/shell QDs meets the requirements of quality QDs in terms of high photoluminescence QY and stability, hence further deposition of additional shells are not necessary in improving the optical properties of the core/shell QDs. Copyright © 2015 John Wiley & Sons, Ltd. , Original publication is available at http://dx.doi.org/10.1002/bio.3013
- Full Text: false
- Date Issued: 2015
Insecticidal activities and chemical composition of the essential oil from Tarchonanthus camphoratus (L.), leaves against Sitophilus zeamais Motschulsky, and Sitophilus oryzae (L.)
- Nanyonga, Sarah K, Opoku, Andy R, Lewu, Francis B, Oyedeji, Adebola O
- Authors: Nanyonga, Sarah K , Opoku, Andy R , Lewu, Francis B , Oyedeji, Adebola O
- Date: 2015
- Language: English
- Type: text , Article
- Identifier: http://hdl.handle.net/11260/711 , vital:29660
- Description: The essential oil of Tarchonanthus camphoratus dry leaves growing in Kwa-Zulu Natal, South Africa was obtained by hydrodistillation and evaluated for its repellent effect, contact and fumigation toxicity against both Sitophilus zeamais and Sarocladium oryzae. Chemical composition of the essential oil was analysed by gas chromatography mass spectrometry (GC/MS). The study revealed that the essential oil of T. camphoratus had no contact and fumigation toxicity against stored insect pests, S. zeamais and S. oryzae. The oil, however, showed good repellent activity of over 50% after 24 h for all the concentrations used on both S. zeamais and S. oryzae. A total of 27 compounds accounting for 73% of the total oil composition were identified of which sesquiterpene hydrocarbons, (59.18%), were the most dominant. These results suggest that the essential oil of T. camphoratus could be considered a potential control agent of stored grain pests as a repellent.
- Full Text:
- Date Issued: 2015
- Authors: Nanyonga, Sarah K , Opoku, Andy R , Lewu, Francis B , Oyedeji, Adebola O
- Date: 2015
- Language: English
- Type: text , Article
- Identifier: http://hdl.handle.net/11260/711 , vital:29660
- Description: The essential oil of Tarchonanthus camphoratus dry leaves growing in Kwa-Zulu Natal, South Africa was obtained by hydrodistillation and evaluated for its repellent effect, contact and fumigation toxicity against both Sitophilus zeamais and Sarocladium oryzae. Chemical composition of the essential oil was analysed by gas chromatography mass spectrometry (GC/MS). The study revealed that the essential oil of T. camphoratus had no contact and fumigation toxicity against stored insect pests, S. zeamais and S. oryzae. The oil, however, showed good repellent activity of over 50% after 24 h for all the concentrations used on both S. zeamais and S. oryzae. A total of 27 compounds accounting for 73% of the total oil composition were identified of which sesquiterpene hydrocarbons, (59.18%), were the most dominant. These results suggest that the essential oil of T. camphoratus could be considered a potential control agent of stored grain pests as a repellent.
- Full Text:
- Date Issued: 2015
Life orientation sexuality education in South Africa: gendered norms, justice and transformation
- Shefer, Tamara, Macleod, Catriona I
- Authors: Shefer, Tamara , Macleod, Catriona I
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:6310 , http://hdl.handle.net/10962/d1018868
- Description: [From introduction] Research on sexual practices among young South Africans has proliferated in light of the national imperatives to challenge the spread of HIV/AIDS, gender-based violence and unwanted early pregnancies. It has been widely acknowledged that, in order to respond to these social problems, we need to understand the enmeshment of gender, class, age and other forms of social inequality, and how these are played out in ‘normal’ heterosexual relationships. Life Orientation (LO) sexuality education programmes have been viewed as key locations for incorporating education to challenge negative assumptions in respect of HIV/AIDS, gender-based violence and unwanted pregnancy and to promote safer, equitable and non-violent sexual practices. There is a paucity of work that interrogates the LO sexuality education programme in terms of gender norms, gender justice and gender transformation. In the handful of studies conducted on school-based sexuality education in South Africa, researchers have foregrounded a number of challenges, including the dominance of a guiding metaphor of danger and disease in the sexuality education component of LO manuals (Macleod, 2009); educators using a transmission mode of teaching to the exclusion of participation and experiential modes of learning (Rooth, 2005); educators understanding sexuality education as chiefly addressing the provision of information concerning, and prevention of, HIV/AIDS (Francis, 2011); teachers’ preference for abstinence-only education taught by means of a series of moral injunctions (Francis, 2011); and the avoidance of discussions of sexual diversity, and the endorsement of compulsory heterosexuality when same-sex relationships are mentioned (Francis, 2012). Recent research has also highlighted the variation in how teachers approach sexuality education. Francis and DePalma (2014) indicate that, while teachers may promote abstinence as the only appropriate choice for young people, they also recognise the value of teaching relationships and safe sex (aspects associated with comprehensive sexuality education). In their study, Helleve et al. (2009) report that Grades 8 and 9 LO teachers felt confident in teaching HIV and sexuality. This special issue of Perspectives in Education builds on this research by drawing together several papers that examine how LO or Life Skills sexuality programmes challenge and/or reproduce normative constructions of gender and gendered power relations. All the papers use qualitative research to locate these programmes within the complex contexts of their enactment, drawing attention to the multiple possibilities and limitations of such programmes. In the next section, we summarise the key problematics addressed in each of the papers. What curiosities drove the studies conducted by these researchers interested in gender dynamics in schools and LO or Life Skills sexuality education? Why are these curiosities important? We then highlight the key findings that emerged from these curiosities and the nuanced data collected. Finally, and most importantly in terms of the aims of this special issue, we address the ways in which a critical gender lens that facilitates gender transformation and gender justice could possibly be incorporated into LO or Life Skills sexuality programmes.
- Full Text:
- Date Issued: 2015
- Authors: Shefer, Tamara , Macleod, Catriona I
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:6310 , http://hdl.handle.net/10962/d1018868
- Description: [From introduction] Research on sexual practices among young South Africans has proliferated in light of the national imperatives to challenge the spread of HIV/AIDS, gender-based violence and unwanted early pregnancies. It has been widely acknowledged that, in order to respond to these social problems, we need to understand the enmeshment of gender, class, age and other forms of social inequality, and how these are played out in ‘normal’ heterosexual relationships. Life Orientation (LO) sexuality education programmes have been viewed as key locations for incorporating education to challenge negative assumptions in respect of HIV/AIDS, gender-based violence and unwanted pregnancy and to promote safer, equitable and non-violent sexual practices. There is a paucity of work that interrogates the LO sexuality education programme in terms of gender norms, gender justice and gender transformation. In the handful of studies conducted on school-based sexuality education in South Africa, researchers have foregrounded a number of challenges, including the dominance of a guiding metaphor of danger and disease in the sexuality education component of LO manuals (Macleod, 2009); educators using a transmission mode of teaching to the exclusion of participation and experiential modes of learning (Rooth, 2005); educators understanding sexuality education as chiefly addressing the provision of information concerning, and prevention of, HIV/AIDS (Francis, 2011); teachers’ preference for abstinence-only education taught by means of a series of moral injunctions (Francis, 2011); and the avoidance of discussions of sexual diversity, and the endorsement of compulsory heterosexuality when same-sex relationships are mentioned (Francis, 2012). Recent research has also highlighted the variation in how teachers approach sexuality education. Francis and DePalma (2014) indicate that, while teachers may promote abstinence as the only appropriate choice for young people, they also recognise the value of teaching relationships and safe sex (aspects associated with comprehensive sexuality education). In their study, Helleve et al. (2009) report that Grades 8 and 9 LO teachers felt confident in teaching HIV and sexuality. This special issue of Perspectives in Education builds on this research by drawing together several papers that examine how LO or Life Skills sexuality programmes challenge and/or reproduce normative constructions of gender and gendered power relations. All the papers use qualitative research to locate these programmes within the complex contexts of their enactment, drawing attention to the multiple possibilities and limitations of such programmes. In the next section, we summarise the key problematics addressed in each of the papers. What curiosities drove the studies conducted by these researchers interested in gender dynamics in schools and LO or Life Skills sexuality education? Why are these curiosities important? We then highlight the key findings that emerged from these curiosities and the nuanced data collected. Finally, and most importantly in terms of the aims of this special issue, we address the ways in which a critical gender lens that facilitates gender transformation and gender justice could possibly be incorporated into LO or Life Skills sexuality programmes.
- Full Text:
- Date Issued: 2015
Maximum firepower: Vale van der Merwe, an emergent ceramic artist at Starways Arts, Hogsback, Eastern Cape, South Africa
- Authors: Steele, John
- Date: 2015
- Language: English
- Type: text , Article
- Identifier: http://hdl.handle.net/11260/979 , vital:30078
- Description: Vale van der Merwe has been working as a ceramic artist for the past five years, and in that time has developed a remarkably diverse repertoire of both thrown and handbuilt works. These include rapidly thrown utilityware as well as carefully conceived sculptural works that engage with ideas rather than primarily with function. She also makes full use of opportunities offered by high-temperature woodburn firings, and despite works collapsing while being made, breaking while being carried to the kiln and slumping during firing, she has used such occasions as opportunities for learning rather than despondency. Van der Merwe is also an actively hands-on ceramic artist who engages with all levels of tasks associated with studio ceramics in a village setting, so has found herself, for example, both creating a new chimney for the kiln, and simultaneously leading discussion around concepts for new collaborative exhibitions. There is a seriousness of intent combined with infectious confidence evident in both her daily presence and ceramics, and it is hoped that she will develop her repertoire and thinkings even further in forthcoming years.
- Full Text:
- Date Issued: 2015
- Authors: Steele, John
- Date: 2015
- Language: English
- Type: text , Article
- Identifier: http://hdl.handle.net/11260/979 , vital:30078
- Description: Vale van der Merwe has been working as a ceramic artist for the past five years, and in that time has developed a remarkably diverse repertoire of both thrown and handbuilt works. These include rapidly thrown utilityware as well as carefully conceived sculptural works that engage with ideas rather than primarily with function. She also makes full use of opportunities offered by high-temperature woodburn firings, and despite works collapsing while being made, breaking while being carried to the kiln and slumping during firing, she has used such occasions as opportunities for learning rather than despondency. Van der Merwe is also an actively hands-on ceramic artist who engages with all levels of tasks associated with studio ceramics in a village setting, so has found herself, for example, both creating a new chimney for the kiln, and simultaneously leading discussion around concepts for new collaborative exhibitions. There is a seriousness of intent combined with infectious confidence evident in both her daily presence and ceramics, and it is hoped that she will develop her repertoire and thinkings even further in forthcoming years.
- Full Text:
- Date Issued: 2015
Mercaptopyridine-substituted indium, zinc, and metal-free phthalocyanines: nonlinear optical studies in solution and on polymer matrices
- Bankole, Owolabi M, Nyokong, Tebello
- Authors: Bankole, Owolabi M , Nyokong, Tebello
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:7278 , http://hdl.handle.net/10962/d1020313
- Description: In this article, the nonlinear optical characterizations and optical limiting properties of metal-free (2), zinc (3), and indium (4) tetra 4-(2-mercaptopyridine) phthalocyanines are discussed. Nonlinear optical properties of the samples were evaluated using Z-scan at 532 nm and 10 ns pulse in CHCl3, and doped on poly(bisphenol A carbonate) (PBC) thin films. Thin films for 2, 3, and 4 are represented as 2-PBC, 3-PBC, and 4-PBC, respectively. We observed two-photon absorption (2PA) and strong reverse saturable absorption as the dominant mechanisms at nanosecond laser excitation in solution and thin films. By virtue of the magnitude of absorption coefficients and other nonlinear optical parameters estimated in this work, sample 4 was found to exhibit strongest nonlinear optical properties followed by 3, while 2 is the weakest nonlinear absorber of the studied samples. Large third-order susceptibility (1.46 × 10−9 esu and 7.74 × 10−10 esu) and hyperpolarizability (2.13 × 10−28 and 8.37 × 10−29 esu) were estimated for 4-PBC and 3-PBC, respectively. Our studies show that these molecules are suitable candidates for practical passive optical limiters. , Original publication is available at http://dx.doi.org/10.1080/00958972.2015.1077237
- Full Text: false
- Date Issued: 2015
- Authors: Bankole, Owolabi M , Nyokong, Tebello
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:7278 , http://hdl.handle.net/10962/d1020313
- Description: In this article, the nonlinear optical characterizations and optical limiting properties of metal-free (2), zinc (3), and indium (4) tetra 4-(2-mercaptopyridine) phthalocyanines are discussed. Nonlinear optical properties of the samples were evaluated using Z-scan at 532 nm and 10 ns pulse in CHCl3, and doped on poly(bisphenol A carbonate) (PBC) thin films. Thin films for 2, 3, and 4 are represented as 2-PBC, 3-PBC, and 4-PBC, respectively. We observed two-photon absorption (2PA) and strong reverse saturable absorption as the dominant mechanisms at nanosecond laser excitation in solution and thin films. By virtue of the magnitude of absorption coefficients and other nonlinear optical parameters estimated in this work, sample 4 was found to exhibit strongest nonlinear optical properties followed by 3, while 2 is the weakest nonlinear absorber of the studied samples. Large third-order susceptibility (1.46 × 10−9 esu and 7.74 × 10−10 esu) and hyperpolarizability (2.13 × 10−28 and 8.37 × 10−29 esu) were estimated for 4-PBC and 3-PBC, respectively. Our studies show that these molecules are suitable candidates for practical passive optical limiters. , Original publication is available at http://dx.doi.org/10.1080/00958972.2015.1077237
- Full Text: false
- Date Issued: 2015
Nonlinear optical properties of natural laccaic acid dye studied using Z-scan technique
- Zongo, S, Sanusi, Kayode, Britton, Jonathan, Mthunzi, P, Nyokong, Tebello, Maaza, M, Sahraoui, B
- Authors: Zongo, S , Sanusi, Kayode , Britton, Jonathan , Mthunzi, P , Nyokong, Tebello , Maaza, M , Sahraoui, B
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:7261 , http://hdl.handle.net/10962/d1020270
- Description: We have investigated the nonlinear optical properties, including the optical limiting behaviour for five different concentrations of laccaic acid dye in solution and a thin film obtained through doping in poly (methyl methacrylate) (PMMA) polymer. The experiments were performed by using single beam Z-scan technique at 532 nm with 10 ns, 10 Hz Nd:YAG laser pulses excitation. From the open-aperture Z-scan data, we derived that the laccaic dye samples exhibit strong two photon absorption (2PA). The nonlinear refractive index was determined through the closed aperture Z-scan data. The estimated absorption coefficient β2, nonlinear refractive index n2 and second order hyperpolarizability γ were found to be of the order of 10−10 m/W, 10−9 esu and 10−32 esu, respectively. The Z-scan study reveals that the natural laccaic acid dye emerges as a promising material for third order nonlinear optical devices application. , Original publication is available at http://dx.doi.org/10.1016/j.optmat.2015.04.031
- Full Text: false
- Date Issued: 2015
- Authors: Zongo, S , Sanusi, Kayode , Britton, Jonathan , Mthunzi, P , Nyokong, Tebello , Maaza, M , Sahraoui, B
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:7261 , http://hdl.handle.net/10962/d1020270
- Description: We have investigated the nonlinear optical properties, including the optical limiting behaviour for five different concentrations of laccaic acid dye in solution and a thin film obtained through doping in poly (methyl methacrylate) (PMMA) polymer. The experiments were performed by using single beam Z-scan technique at 532 nm with 10 ns, 10 Hz Nd:YAG laser pulses excitation. From the open-aperture Z-scan data, we derived that the laccaic dye samples exhibit strong two photon absorption (2PA). The nonlinear refractive index was determined through the closed aperture Z-scan data. The estimated absorption coefficient β2, nonlinear refractive index n2 and second order hyperpolarizability γ were found to be of the order of 10−10 m/W, 10−9 esu and 10−32 esu, respectively. The Z-scan study reveals that the natural laccaic acid dye emerges as a promising material for third order nonlinear optical devices application. , Original publication is available at http://dx.doi.org/10.1016/j.optmat.2015.04.031
- Full Text: false
- Date Issued: 2015
Nonlinear optical response of tetra and mono substituted zinc phthalocyanine complexes
- Fashina, Adedayo, Nyokong, Tebello
- Authors: Fashina, Adedayo , Nyokong, Tebello
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:7281 , http://hdl.handle.net/10962/d1020318 , Original publication is available at http://dx.doi.org/10.1016/j.jlumin.2015.06.003
- Description: The nonlinear absorption properties of 6 mono-substituted and 3 symmetric zinc phthalocyanine complexes have been studied in dimethylsulfoxide (DMSO) using 10 ns pulses at 532 nm. The non linear absorption of the complexes has been studied using the Z-scan technique. The study showed that both the singlet and triplet excited states contribute to the non linear absorption behavior. The nonlinear third-order susceptibility and second-order hyperpolarizability values of the complexes are reported. It was observed that two of the symmetric phthalocyanine complexes (5-α substituted with aminophenoxy and 9-β substituted with carboxyphenoxy) showed better and promising optical nonlinearity when compared to the other complexes studied.
- Full Text: false
- Date Issued: 2015
- Authors: Fashina, Adedayo , Nyokong, Tebello
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:7281 , http://hdl.handle.net/10962/d1020318 , Original publication is available at http://dx.doi.org/10.1016/j.jlumin.2015.06.003
- Description: The nonlinear absorption properties of 6 mono-substituted and 3 symmetric zinc phthalocyanine complexes have been studied in dimethylsulfoxide (DMSO) using 10 ns pulses at 532 nm. The non linear absorption of the complexes has been studied using the Z-scan technique. The study showed that both the singlet and triplet excited states contribute to the non linear absorption behavior. The nonlinear third-order susceptibility and second-order hyperpolarizability values of the complexes are reported. It was observed that two of the symmetric phthalocyanine complexes (5-α substituted with aminophenoxy and 9-β substituted with carboxyphenoxy) showed better and promising optical nonlinearity when compared to the other complexes studied.
- Full Text: false
- Date Issued: 2015
Optical limiting and singlet oxygen generation properties of phosphorus triazatetrabenzcorroles
- Mkhize, Colin, Britton, Jonathan, Mack, John, Nyokong, Tebello
- Authors: Mkhize, Colin , Britton, Jonathan , Mack, John , Nyokong, Tebello
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:7257 , http://hdl.handle.net/10962/d1020266
- Description: Novel phosphorus triazatetrabenzcorrole (TBC) tetrasubstituted at the α- and β-positions of the peripheral fused benzene rings with t-butylphenoxy substituents have been prepared and characterized. The effect of the substituents on the electronic structures and optical properties is investigated with TD-DFT calculations and MCD spectroscopy. The optical limiting properties have been investigated to examine whether the lower symmetry that results from the direct pyrrole–pyrrole bond and hence the permanent dipole moment that is introduced result in higher safety thresholds, relative to the values that have been reported for phthalocyanines. The suitability of the compounds for singlet oxygen applications has also been examined. , Original publication is available at http://dx.doi.org/10.1142/S1088424614501065
- Full Text: false
- Date Issued: 2015
- Authors: Mkhize, Colin , Britton, Jonathan , Mack, John , Nyokong, Tebello
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:7257 , http://hdl.handle.net/10962/d1020266
- Description: Novel phosphorus triazatetrabenzcorrole (TBC) tetrasubstituted at the α- and β-positions of the peripheral fused benzene rings with t-butylphenoxy substituents have been prepared and characterized. The effect of the substituents on the electronic structures and optical properties is investigated with TD-DFT calculations and MCD spectroscopy. The optical limiting properties have been investigated to examine whether the lower symmetry that results from the direct pyrrole–pyrrole bond and hence the permanent dipole moment that is introduced result in higher safety thresholds, relative to the values that have been reported for phthalocyanines. The suitability of the compounds for singlet oxygen applications has also been examined. , Original publication is available at http://dx.doi.org/10.1142/S1088424614501065
- Full Text: false
- Date Issued: 2015
Optical properties of water-soluble l-cysteine-capped alloyed CdSeS quantum dot passivated with ZnSeTe and ZnSeTe/ZnS shells
- Adegoke, Oluwasesan, Nyokong, Tebello, Forbes, Patricia B C
- Authors: Adegoke, Oluwasesan , Nyokong, Tebello , Forbes, Patricia B C
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:7260 , http://hdl.handle.net/10962/d1020269
- Description: Alloyed quantum dots (QDs) passivated with shell materials have valuable optical characteristics suitable for a wide array of applications. In this work, alloyed ternary CdSeS QDs passivated with ZnSeTe and ZnSeTe/ZnS shells have been synthesized via a hot-injection method and a ligand exchange reaction employing l-cysteine as a thiol ligand has been used to obtain these water-soluble nanocrystals for the first time. The photoluminescence (PL) quantum yield (QY) of alloyed l-cysteine-capped CdSeS was 71.2% but decreased significantly to 5.2% upon passivation with a ZnSeTe shell. The red shift in PL emission of the CdSeS/ZnSeTe QDs was attributed to be strain-induced whilst a lattice-induced process likely created defect states in the core/shell interface hence contributing to the decline in the PL QY. Nonetheless, the fluorescence stability of CdSeS/ZnSeTe QDs in aqueous solution was unperturbed. Further passivation with a ZnS shell (CdSeS/ZnSeTe/ZnS) improved the PL QY to a value of 58.7% and thus indicates that the defect state in the QDs core/shell/shell structure was reduced. PL lifetime exciton measurements indicated that the rates of decay of the QDs influenced their photophysical properties. , Original publication is available at http://dx.doi.org/10.1016/j.optmat.2015.05.024
- Full Text: false
- Date Issued: 2015
- Authors: Adegoke, Oluwasesan , Nyokong, Tebello , Forbes, Patricia B C
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:7260 , http://hdl.handle.net/10962/d1020269
- Description: Alloyed quantum dots (QDs) passivated with shell materials have valuable optical characteristics suitable for a wide array of applications. In this work, alloyed ternary CdSeS QDs passivated with ZnSeTe and ZnSeTe/ZnS shells have been synthesized via a hot-injection method and a ligand exchange reaction employing l-cysteine as a thiol ligand has been used to obtain these water-soluble nanocrystals for the first time. The photoluminescence (PL) quantum yield (QY) of alloyed l-cysteine-capped CdSeS was 71.2% but decreased significantly to 5.2% upon passivation with a ZnSeTe shell. The red shift in PL emission of the CdSeS/ZnSeTe QDs was attributed to be strain-induced whilst a lattice-induced process likely created defect states in the core/shell interface hence contributing to the decline in the PL QY. Nonetheless, the fluorescence stability of CdSeS/ZnSeTe QDs in aqueous solution was unperturbed. Further passivation with a ZnS shell (CdSeS/ZnSeTe/ZnS) improved the PL QY to a value of 58.7% and thus indicates that the defect state in the QDs core/shell/shell structure was reduced. PL lifetime exciton measurements indicated that the rates of decay of the QDs influenced their photophysical properties. , Original publication is available at http://dx.doi.org/10.1016/j.optmat.2015.05.024
- Full Text: false
- Date Issued: 2015
Photodynamic antimicrobial chemotherapy activity of (5,10,15,20-tetrakis(4-(4-carboxyphenycarbonoimidoyl)phenyl)porphyrinato) chloro gallium(III)
- Managa, Muthumuni, Amuhaya, Edith, Nyokong, Tebello
- Authors: Managa, Muthumuni , Amuhaya, Edith , Nyokong, Tebello
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:7296 , http://hdl.handle.net/10962/d1020359
- Description: (5,10,15,20-Tetrakis(4-(4-carboxyphenycarbonoimidoyl)phenyl)porphyrinato) chloro gallium(III) (complex 1) was conjugated to platinum nanoparticles (PtNPs) (represented as 1-PtNPs). The resulting conjugate showed 18 nm red shift in the Soret band when compared to 1 alone. Complex 1 and 1-PtNPs showed promising photodynamic antimicrobial chemotherapy (PACT) activity against Staphylococcus aureus, Escherichia coli and Candida albicans in solution where the log reductions obtained were 4.92, 3.76, and 3.95, respectively for 1-PtNPs. The singlet oxygen quantum yields obtained were higher at 0.56 for 1-PtNPs in DMF while that of 1 was 0.52 in the same solvent. This resulted in improved PACT activity for 1-PtNPs compared to 1 alone. , Original publication is available at http://dx.doi.org/10.1016/j.saa.2015.06.088
- Full Text: false
- Date Issued: 2015
- Authors: Managa, Muthumuni , Amuhaya, Edith , Nyokong, Tebello
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:7296 , http://hdl.handle.net/10962/d1020359
- Description: (5,10,15,20-Tetrakis(4-(4-carboxyphenycarbonoimidoyl)phenyl)porphyrinato) chloro gallium(III) (complex 1) was conjugated to platinum nanoparticles (PtNPs) (represented as 1-PtNPs). The resulting conjugate showed 18 nm red shift in the Soret band when compared to 1 alone. Complex 1 and 1-PtNPs showed promising photodynamic antimicrobial chemotherapy (PACT) activity against Staphylococcus aureus, Escherichia coli and Candida albicans in solution where the log reductions obtained were 4.92, 3.76, and 3.95, respectively for 1-PtNPs. The singlet oxygen quantum yields obtained were higher at 0.56 for 1-PtNPs in DMF while that of 1 was 0.52 in the same solvent. This resulted in improved PACT activity for 1-PtNPs compared to 1 alone. , Original publication is available at http://dx.doi.org/10.1016/j.saa.2015.06.088
- Full Text: false
- Date Issued: 2015