‘… a huge monster that should be feared and not done’: lessons learned in sexuality education classes in South Africa
- Shefer, Tamara, Kruger, Lou-Marie, Macleod, Catriona I, Baxen, Jean, Vincent, Louise
- Authors: Shefer, Tamara , Kruger, Lou-Marie , Macleod, Catriona I , Baxen, Jean , Vincent, Louise
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:6314 , http://hdl.handle.net/10962/d1020933 , http://www.mrc.ac.za/crime/aspj/2015/AhugeMonster.pdf
- Description: Research has foregrounded the way in which heterosexual practices for many young people are not infrequently bound up with violence and unequal transactional power relations. The Life Orientation sexuality education curriculum in South African schools has been viewed as a potentially valuable space to work with young people on issues of reproductive health, gender and sexual norms and relations. Yet, research has illustrated that such work may not only be failing to impact on more equitable sexual practices between young men and women, but may also serve to reproduce the very discourses and practices that the work aims to challenge. Cultures of violence in youth sexuality are closely connected to prevailing gender norms and practices which, for example, render women as passive victims who are incapable of exercising sexual agency and men as inherently sexually predatory. This paper analyses the talk of Grade 10 learners in nine diverse schools in two South African provinces, the Eastern Cape and the Western Cape, to highlight what ‘lessons’ these young people seem to be learning about sexuality in Life Orientation classes. We find that these lessons foreground cautionary, negative and punitive messages, which reinforce, rather than challenge, normative gender roles. ‘Scare’ messages of danger, damage and disease give rise to presumptions of gendered responsibility for risk and the requirement of female restraint in the face of the assertion of masculine desire and predation. We conclude that the role which sexuality education could play in enabling young women in particular to more successfully negotiate their sexual relationships to serve their own needs, reproductive health and safety, is undermined by regulatory messages directed at controlling young people, and young women in particular – and that instead, young people’s sexual agency has to be acknowledged in any processes of change aimed at gender equality, anti-violence, health and well-being.
- Full Text:
- Date Issued: 2015
- Authors: Shefer, Tamara , Kruger, Lou-Marie , Macleod, Catriona I , Baxen, Jean , Vincent, Louise
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:6314 , http://hdl.handle.net/10962/d1020933 , http://www.mrc.ac.za/crime/aspj/2015/AhugeMonster.pdf
- Description: Research has foregrounded the way in which heterosexual practices for many young people are not infrequently bound up with violence and unequal transactional power relations. The Life Orientation sexuality education curriculum in South African schools has been viewed as a potentially valuable space to work with young people on issues of reproductive health, gender and sexual norms and relations. Yet, research has illustrated that such work may not only be failing to impact on more equitable sexual practices between young men and women, but may also serve to reproduce the very discourses and practices that the work aims to challenge. Cultures of violence in youth sexuality are closely connected to prevailing gender norms and practices which, for example, render women as passive victims who are incapable of exercising sexual agency and men as inherently sexually predatory. This paper analyses the talk of Grade 10 learners in nine diverse schools in two South African provinces, the Eastern Cape and the Western Cape, to highlight what ‘lessons’ these young people seem to be learning about sexuality in Life Orientation classes. We find that these lessons foreground cautionary, negative and punitive messages, which reinforce, rather than challenge, normative gender roles. ‘Scare’ messages of danger, damage and disease give rise to presumptions of gendered responsibility for risk and the requirement of female restraint in the face of the assertion of masculine desire and predation. We conclude that the role which sexuality education could play in enabling young women in particular to more successfully negotiate their sexual relationships to serve their own needs, reproductive health and safety, is undermined by regulatory messages directed at controlling young people, and young women in particular – and that instead, young people’s sexual agency has to be acknowledged in any processes of change aimed at gender equality, anti-violence, health and well-being.
- Full Text:
- Date Issued: 2015
“Bold Distinguished You”: a critical discourse analysis of the representation of masculinity in Destiny Man, 2012 - 2013
- Authors: Hutcheson, Lauren
- Date: 2015
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/56032 , vital:26767
- Description: Radical social and economic changes have transformed the employment opportunities available to black men in South Africa, and consumer magazines like Destiny Man have been quick to respond. Historical shifts in the configuration of an ideal black masculinity have been proposed over time in magazine representations of black men. Critiques of the representations of black men in consumer magazines pre- and post- independence interrogate the politics of the ways in which black masculinity has been, and is, configured around classed identities. In this study, I present the findings of a critical discourse analysis (CDA) on the construction and representation of masculinity within a contemporary South African’s men’s lifestyle magazine, Destiny Man. This study presents an analysis of the subject positions that this magazine constructs for its male readers. Destiny Man proposes particular kinds of discursive subjects in its sets of representations, both in word and image. The images and copy validate a neo-liberal elite masculinity achieved through self-surveillance and a variety of technologies of self, with the ultimate focus on material success. I argue that these representations have implications for the development of masculinities in a context marked by extreme inequality.
- Full Text:
- Date Issued: 2015
- Authors: Hutcheson, Lauren
- Date: 2015
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/56032 , vital:26767
- Description: Radical social and economic changes have transformed the employment opportunities available to black men in South Africa, and consumer magazines like Destiny Man have been quick to respond. Historical shifts in the configuration of an ideal black masculinity have been proposed over time in magazine representations of black men. Critiques of the representations of black men in consumer magazines pre- and post- independence interrogate the politics of the ways in which black masculinity has been, and is, configured around classed identities. In this study, I present the findings of a critical discourse analysis (CDA) on the construction and representation of masculinity within a contemporary South African’s men’s lifestyle magazine, Destiny Man. This study presents an analysis of the subject positions that this magazine constructs for its male readers. Destiny Man proposes particular kinds of discursive subjects in its sets of representations, both in word and image. The images and copy validate a neo-liberal elite masculinity achieved through self-surveillance and a variety of technologies of self, with the ultimate focus on material success. I argue that these representations have implications for the development of masculinities in a context marked by extreme inequality.
- Full Text:
- Date Issued: 2015
“Ha! Relationships? I only shout at them!”: Strategic management of discordant rapport in an African small business context
- Lauriks, Sanne, Siebörger, Ian, De Vos, Mark A
- Authors: Lauriks, Sanne , Siebörger, Ian , De Vos, Mark A
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/385338 , vital:68009 , xlink:href="https://doi.org/10.1515/pr-2015-0002"
- Description: This study demonstrates how and why interactants at a tyre fitment centre in Grahamstown, South Africa, manage discordant interpersonal relationships in strategic ways. Individuals in a post-apartheid small business respond to their social and economic context and exercise agency to their advantage in doing so. This study draws on linguistic ethnography (Rampton 2007) and the Rapport Management Framework (RMF, Spencer-Oatey 2000b, 2011), itself a development of politeness theory (Brown and Levinson 1987). An initial RMF analysis ran into difficulties around interactions that at first glance appeared to be oriented toward Rapport Challenge and Neglect. Upon closer examination, it appeared that discordant rapport was being actively maintained in this business. This led us to address underdeveloped areas of RMF that were not responsive enough to describe naturally occurring small business interactions, and propose an Enhanced Rapport Management Framework to overcome its inadequacies. We conclude that people may deliberately maintain discordant relationships when it is in their best interests to do so. Thus, contrary to a common-sense belief that harmonious social relations are an intrinsic good, we found that promoting discordant social relations can be understood as a rational response to individuals’ social and economic contexts, particularly in conditions such as those in many postcolonial African societies.
- Full Text:
- Date Issued: 2015
- Authors: Lauriks, Sanne , Siebörger, Ian , De Vos, Mark A
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/385338 , vital:68009 , xlink:href="https://doi.org/10.1515/pr-2015-0002"
- Description: This study demonstrates how and why interactants at a tyre fitment centre in Grahamstown, South Africa, manage discordant interpersonal relationships in strategic ways. Individuals in a post-apartheid small business respond to their social and economic context and exercise agency to their advantage in doing so. This study draws on linguistic ethnography (Rampton 2007) and the Rapport Management Framework (RMF, Spencer-Oatey 2000b, 2011), itself a development of politeness theory (Brown and Levinson 1987). An initial RMF analysis ran into difficulties around interactions that at first glance appeared to be oriented toward Rapport Challenge and Neglect. Upon closer examination, it appeared that discordant rapport was being actively maintained in this business. This led us to address underdeveloped areas of RMF that were not responsive enough to describe naturally occurring small business interactions, and propose an Enhanced Rapport Management Framework to overcome its inadequacies. We conclude that people may deliberately maintain discordant relationships when it is in their best interests to do so. Thus, contrary to a common-sense belief that harmonious social relations are an intrinsic good, we found that promoting discordant social relations can be understood as a rational response to individuals’ social and economic contexts, particularly in conditions such as those in many postcolonial African societies.
- Full Text:
- Date Issued: 2015
“Mother of the Nation”: representations of womanhood in South African media
- Authors: Hunt, Sally
- Date: 2015
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/139229 , vital:37717 , ISBN 9789027206565 , https://benjamins.com/catalog/dapsac.65
- Description: The discourses of the post-apartheid South Africa embody symbols of change and promises of new lessons in history. This is the first volume that brings together analyses of a variety of discourses produced in South Africa through which we follow the evolution of transitional processes in the country’s political institutions and in the opinions of its populace. The book offers to the reader a visit to the Parliament, a peek into the internet forums, analyses of the country's official papers and speeches, and the media accounts. Through all these discourses we see the burning questions – "Who Are We Now?" and "Who Do We Want To Be?" – being repetitively examined and identities cross-formed while the country deals with new, post-apartheid challenges, as well as successes.
- Full Text:
- Date Issued: 2015
- Authors: Hunt, Sally
- Date: 2015
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/139229 , vital:37717 , ISBN 9789027206565 , https://benjamins.com/catalog/dapsac.65
- Description: The discourses of the post-apartheid South Africa embody symbols of change and promises of new lessons in history. This is the first volume that brings together analyses of a variety of discourses produced in South Africa through which we follow the evolution of transitional processes in the country’s political institutions and in the opinions of its populace. The book offers to the reader a visit to the Parliament, a peek into the internet forums, analyses of the country's official papers and speeches, and the media accounts. Through all these discourses we see the burning questions – "Who Are We Now?" and "Who Do We Want To Be?" – being repetitively examined and identities cross-formed while the country deals with new, post-apartheid challenges, as well as successes.
- Full Text:
- Date Issued: 2015
“Peer pressure” and “Peer normalization” : discursive resources that justify gendered youth sexualities
- Macleod, Catriona I, Jearey-Graham, Nicola
- Authors: Macleod, Catriona I , Jearey-Graham, Nicola
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:6312 , http://hdl.handle.net/10962/d1019877 , https://link.springer.com/article/10.1007/s13178-015-0207-8
- Description: “Peer pressure” is associated in the scientific literature with a range of risky sexual behaviors and with undermining public sexual health messages. Interventions are instituted encouraging young people to resist peer pressure or to model positive peer norms. Taking a discursive psychology perspective, we show how young people themselves use the discourses of “peer pressure to have sex” and “peer normalization of sex” to explain and justify youth sexual activity. Using data from focus group discussions about youth sexualities with students at a South African further education and training college, we show how participants outlined a need for young people to be socially recognizable through engaging in, and talking about, sex and how they implicated peer norms in governing individual sexual behavior. Both discourses pointed to a gendering of peer-endorsed sexual norms: masculine virility, the avoidance of shameful virgin or gay positions, and multiple sexual partners were emphasized for men, while the necessity of keeping a boyfriend and avoiding a “slut” position were foregrounded for women. These discourses potentially undermine the aims of public sexual health programs targeting youth. Nuanced engagement with peer group narratives, especially how sexual activity is explained and justified in a gendered fashion, is indicated. , Full text access on Publisher website: https://link.springer.com/article/10.1007/s13178-015-0207-8
- Full Text: false
- Date Issued: 2015
- Authors: Macleod, Catriona I , Jearey-Graham, Nicola
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:6312 , http://hdl.handle.net/10962/d1019877 , https://link.springer.com/article/10.1007/s13178-015-0207-8
- Description: “Peer pressure” is associated in the scientific literature with a range of risky sexual behaviors and with undermining public sexual health messages. Interventions are instituted encouraging young people to resist peer pressure or to model positive peer norms. Taking a discursive psychology perspective, we show how young people themselves use the discourses of “peer pressure to have sex” and “peer normalization of sex” to explain and justify youth sexual activity. Using data from focus group discussions about youth sexualities with students at a South African further education and training college, we show how participants outlined a need for young people to be socially recognizable through engaging in, and talking about, sex and how they implicated peer norms in governing individual sexual behavior. Both discourses pointed to a gendering of peer-endorsed sexual norms: masculine virility, the avoidance of shameful virgin or gay positions, and multiple sexual partners were emphasized for men, while the necessity of keeping a boyfriend and avoiding a “slut” position were foregrounded for women. These discourses potentially undermine the aims of public sexual health programs targeting youth. Nuanced engagement with peer group narratives, especially how sexual activity is explained and justified in a gendered fashion, is indicated. , Full text access on Publisher website: https://link.springer.com/article/10.1007/s13178-015-0207-8
- Full Text: false
- Date Issued: 2015
A high-level architecture for efficient packet trace analysis on gpu co-processors
- Nottingham, Alastair, Irwin, Barry V W
- Authors: Nottingham, Alastair , Irwin, Barry V W
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429572 , vital:72623 , 10.1109/ISSA.2013.6641052
- Description: This paper proposes a high-level architecture to support efficient, massively parallel packet classification, filtering and analysis using commodity Graphics Processing Unit (GPU) hardware. The proposed architecture aims to provide a flexible and efficient parallel packet processing and analysis framework, supporting complex programmable filtering, data mining operations, statistical analysis functions and traffic visualisation, with minimal CPU overhead. In particular, this framework aims to provide a robust set of high-speed analysis functionality, in order to dramatically reduce the time required to process and analyse extremely large network traces. This architecture derives from initial research, which has shown GPU co-processors to be effective in accelerating packet classification to up to tera-bit speeds with minimal CPU overhead, far exceeding the bandwidth capacity between standard long term storage and the GPU device. This paper provides a high-level overview of the proposed architecture and its primary components, motivated by the results of prior research in the field.
- Full Text:
- Date Issued: 2013
- Authors: Nottingham, Alastair , Irwin, Barry V W
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429572 , vital:72623 , 10.1109/ISSA.2013.6641052
- Description: This paper proposes a high-level architecture to support efficient, massively parallel packet classification, filtering and analysis using commodity Graphics Processing Unit (GPU) hardware. The proposed architecture aims to provide a flexible and efficient parallel packet processing and analysis framework, supporting complex programmable filtering, data mining operations, statistical analysis functions and traffic visualisation, with minimal CPU overhead. In particular, this framework aims to provide a robust set of high-speed analysis functionality, in order to dramatically reduce the time required to process and analyse extremely large network traces. This architecture derives from initial research, which has shown GPU co-processors to be effective in accelerating packet classification to up to tera-bit speeds with minimal CPU overhead, far exceeding the bandwidth capacity between standard long term storage and the GPU device. This paper provides a high-level overview of the proposed architecture and its primary components, motivated by the results of prior research in the field.
- Full Text:
- Date Issued: 2013
A kernel-driven framework for high performance internet routing simulation
- Herbert, Alan, Irwin, Barry V W
- Authors: Herbert, Alan , Irwin, Barry V W
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429585 , vital:72624 , 10.1109/ISSA.2013.6641048
- Description: The ability to provide the simulation of packets traversing an internet path is an integral part of providing realistic simulations for network training, and cyber defence exercises. This paper builds on previous work, and considers an in-kernel approach to solving the routing simulation problem. The inkernel approach is anticipated to allow the framework to be able to achieve throughput rates of 1GB/s or higher using commodity hardware. Processes that run outside the context of the kernel of most operating system require context switching to access hardware and kernel modules. This leads to considerable delays in the processes, such as network simulators, that frequently access hardware such as hard disk accesses and network packet handling. To mitigate this problem, as experienced with earlier implementations, this research looks towards implementing a kernel module to handle network routing and simulation within a UNIX based system. This would remove delays incurred from context switching and allows for direct access to the hardware components of the host.
- Full Text:
- Date Issued: 2013
- Authors: Herbert, Alan , Irwin, Barry V W
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429585 , vital:72624 , 10.1109/ISSA.2013.6641048
- Description: The ability to provide the simulation of packets traversing an internet path is an integral part of providing realistic simulations for network training, and cyber defence exercises. This paper builds on previous work, and considers an in-kernel approach to solving the routing simulation problem. The inkernel approach is anticipated to allow the framework to be able to achieve throughput rates of 1GB/s or higher using commodity hardware. Processes that run outside the context of the kernel of most operating system require context switching to access hardware and kernel modules. This leads to considerable delays in the processes, such as network simulators, that frequently access hardware such as hard disk accesses and network packet handling. To mitigate this problem, as experienced with earlier implementations, this research looks towards implementing a kernel module to handle network routing and simulation within a UNIX based system. This would remove delays incurred from context switching and allows for direct access to the hardware components of the host.
- Full Text:
- Date Issued: 2013
Deep Routing Simulation
- Irwin, Barry V W, Herbert, Alan
- Authors: Irwin, Barry V W , Herbert, Alan
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430353 , vital:72685 , https://www.academic-bookshop.com/ourshop/prod_2546879-ICIW-2013-8th-International-Conference-on-Information-Warfare-and-Security.html
- Description: This paper discusses a dataset of some 16 million packets targeting port 445/tcp collected by a network telescope utilising a /24 netblock in South African IP address space. An initial overview of the collected data is provided. This is followed by a detailed analysis of the packet characteristics observed, including size and TTL. The peculiarities of the observed target selection and the results of the flaw in the Conficker worm's propagation algorithm are presented. An analysis of the 4 million observed source hosts is reported, grouped by both packet counts and the number of distinct hosts per network address block. Address blocks of size /8, 16 and 24 are used for groupings. The localisation, by geographic region and numerical proximity, of high ranking aggregate netblocks is highlighted. The observed shift in geopolitical origins observed during the evolution of the Conficker worm is also discussed. The paper concludes with some overall analyses, and consideration of the application of network telescopes to the monitoring of such outbreaks in the future.
- Full Text:
- Date Issued: 2013
- Authors: Irwin, Barry V W , Herbert, Alan
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430353 , vital:72685 , https://www.academic-bookshop.com/ourshop/prod_2546879-ICIW-2013-8th-International-Conference-on-Information-Warfare-and-Security.html
- Description: This paper discusses a dataset of some 16 million packets targeting port 445/tcp collected by a network telescope utilising a /24 netblock in South African IP address space. An initial overview of the collected data is provided. This is followed by a detailed analysis of the packet characteristics observed, including size and TTL. The peculiarities of the observed target selection and the results of the flaw in the Conficker worm's propagation algorithm are presented. An analysis of the 4 million observed source hosts is reported, grouped by both packet counts and the number of distinct hosts per network address block. Address blocks of size /8, 16 and 24 are used for groupings. The localisation, by geographic region and numerical proximity, of high ranking aggregate netblocks is highlighted. The observed shift in geopolitical origins observed during the evolution of the Conficker worm is also discussed. The paper concludes with some overall analyses, and consideration of the application of network telescopes to the monitoring of such outbreaks in the future.
- Full Text:
- Date Issued: 2013
Synthesis of phthalocyanine conjugates with gold nanoparticles and liposomes for photodynamic therapy
- Nombona, Nolwazi, Maduray, Kaminee, Antunes, Edith M, Karsten, Aletta, Nyokong, Tebello
- Authors: Nombona, Nolwazi , Maduray, Kaminee , Antunes, Edith M , Karsten, Aletta , Nyokong, Tebello
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/245798 , vital:51406 , xlink:href="https://doi.org/10.1016/j.jphotobiol.2011.11.007"
- Description: The efficiency of [2,9,17,23-tetrakis-(1,6-hexanedithiol)phthalocyaninato]zinc(II) as a photodynamic therapy (PDT) agent was investigated. This compound belongs to the second generation of photosensitizers currently tested for the cellular photo-damage of cancer cells. The production of reactive oxygen species (ROS) and phototoxicity of the photosensitizer were assessed. Healthy fibroblast cells and breast cancer (MCF-7) cells were treated with either free phthalocyanine or phthalocyanine bound to either gold nanoparticles or encapsulated in liposomes. Cell viability studies showed the optimum phototoxic effect on non-malignant cells to be 4.5 J cm−2. The PDT effect of the liposome bound phthalocyanine showed extensive damage of the breast cancer cells. Gold nanoparticles only showed a modest improvement in PDT activity.
- Full Text:
- Date Issued: 2012
- Authors: Nombona, Nolwazi , Maduray, Kaminee , Antunes, Edith M , Karsten, Aletta , Nyokong, Tebello
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/245798 , vital:51406 , xlink:href="https://doi.org/10.1016/j.jphotobiol.2011.11.007"
- Description: The efficiency of [2,9,17,23-tetrakis-(1,6-hexanedithiol)phthalocyaninato]zinc(II) as a photodynamic therapy (PDT) agent was investigated. This compound belongs to the second generation of photosensitizers currently tested for the cellular photo-damage of cancer cells. The production of reactive oxygen species (ROS) and phototoxicity of the photosensitizer were assessed. Healthy fibroblast cells and breast cancer (MCF-7) cells were treated with either free phthalocyanine or phthalocyanine bound to either gold nanoparticles or encapsulated in liposomes. Cell viability studies showed the optimum phototoxic effect on non-malignant cells to be 4.5 J cm−2. The PDT effect of the liposome bound phthalocyanine showed extensive damage of the breast cancer cells. Gold nanoparticles only showed a modest improvement in PDT activity.
- Full Text:
- Date Issued: 2012
Histological validation of gonadal macroscopic staging criteria for Labeo cylindricus (Pisces: Cyprinidae)
- Booth, Anthony J, Weyl, Olaf L F
- Authors: Booth, Anthony J , Weyl, Olaf L F
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124593 , vital:35634 , https://doi.org/10.1080/15627020.2000.11657094
- Description: Histological examination of gametogenesis revealed that the current staging criteria used to assess gonadal recrudescence of the redeye labeo, Labeo cylindricus, were adequate. Gametogenesis was qualitatively similar to that of freshwater teleosts with a clearly defined seasonal reproductive cycle. L. cylindricus undergoes seasonal gross morphological and cytological gonadal changes with previtellogenesis dominating during the winter, vitellogenic development during spring and summer culminating in large-scale spawning at the end of summer. Post-spawning mass atresia of oocytes was evident in autumn. The histological data presented support macroscopical evidence that L. cylindricus is a synchronous iteroparous spawner, reproducing over a short period each year throughout its life-span.
- Full Text:
- Date Issued: 2010
- Authors: Booth, Anthony J , Weyl, Olaf L F
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124593 , vital:35634 , https://doi.org/10.1080/15627020.2000.11657094
- Description: Histological examination of gametogenesis revealed that the current staging criteria used to assess gonadal recrudescence of the redeye labeo, Labeo cylindricus, were adequate. Gametogenesis was qualitatively similar to that of freshwater teleosts with a clearly defined seasonal reproductive cycle. L. cylindricus undergoes seasonal gross morphological and cytological gonadal changes with previtellogenesis dominating during the winter, vitellogenic development during spring and summer culminating in large-scale spawning at the end of summer. Post-spawning mass atresia of oocytes was evident in autumn. The histological data presented support macroscopical evidence that L. cylindricus is a synchronous iteroparous spawner, reproducing over a short period each year throughout its life-span.
- Full Text:
- Date Issued: 2010
Synthesis, photophysical and photochemical properties of octa-substituted antimony phthalocyanines
- Modibane, Desmond Kwena, Nyokong, Tebello
- Authors: Modibane, Desmond Kwena , Nyokong, Tebello
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/264226 , vital:53711 , xlink:href="https://doi.org/10.1016/j.poly.2008.11.052"
- Description: This work reports on the synthesis and photophysicochemical parameters of unsubstituted [SbIIIPc]+I3- and octa-phenoxy ([SbIIIOPPc]+I3-) and -4-t-butylphenoxy ([SbIIIOTBPPc]+I3-) substituted antimony phthalocyanines. Photophysical and photochemical properties were studied for these complexes in dimethylsulfoxide, dimethylformamide and toluene. The excitation spectra of oxidized antimony (Sb(V)Pc) derivates were similar to absorption spectra. Low fluorescence quantum yields, high triplet quantum yields and low triplet lifetimes were observed as the result of heavy atom (antimony ion).
- Full Text:
- Date Issued: 2009
- Authors: Modibane, Desmond Kwena , Nyokong, Tebello
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/264226 , vital:53711 , xlink:href="https://doi.org/10.1016/j.poly.2008.11.052"
- Description: This work reports on the synthesis and photophysicochemical parameters of unsubstituted [SbIIIPc]+I3- and octa-phenoxy ([SbIIIOPPc]+I3-) and -4-t-butylphenoxy ([SbIIIOTBPPc]+I3-) substituted antimony phthalocyanines. Photophysical and photochemical properties were studied for these complexes in dimethylsulfoxide, dimethylformamide and toluene. The excitation spectra of oxidized antimony (Sb(V)Pc) derivates were similar to absorption spectra. Low fluorescence quantum yields, high triplet quantum yields and low triplet lifetimes were observed as the result of heavy atom (antimony ion).
- Full Text:
- Date Issued: 2009
(Ferrocenylpyrazolyl)zinc(II) benzoates as catalysts for the ring opening polymerization of ε-caprolactone
- Obuah, Collins, Lochee, Yemanlall, Jordaan, Johan H L, Otto, Daniel P, Nyokong, Tebello, Darkwa, James
- Authors: Obuah, Collins , Lochee, Yemanlall , Jordaan, Johan H L , Otto, Daniel P , Nyokong, Tebello , Darkwa, James
- Language: English
- Type: Article
- Identifier: vital:7264 , http://hdl.handle.net/10962/d1020273
- Description: The reaction of Zn(OAc)2 and C6H5COOH or 3,5-NO2-C6H3COOH with 3-ferrocenylpyrazolyl-methylenepyridine (L1), 3-ferrocenyl-5-methylpyrazolyl-methylenepyridine (L2), 3-ferrocenylpyrazolyl-ethylamine (L3) and 3-ferrocenyl-5-pyrazolyl-ethylamine (L4) afford the corresponding complexes [Zn(C6H5COO)2(L1)] (1), [Zn(C6H5COO)2(L2)] (2), [Zn(3,5-NO2-C6H3COO)2(L1)] (3), [Zn(3,5-NO2-C6H3COO)2(L2)] (4), [Zn(C6H5COO)2(L3)] (5), [Zn(C6H5COO)2(L4)] (6), [Zn(3,5-NO2-C6H3COO)2(L3)] (7) and [Zn(3,5-NO2-C6H3COO)2(L4)] (8). These complexes behave as catalysts for the ring opening polymerization of ɛ-caprolactone to produce polymers with molecular weight that range from 1480 to 7080 g mol−1 and exhibited moderate to broad PDIs. Evidence of these complexes acting as catalysts was obtained from both the polymerization data and kinetic studies. The polymerization data show that variation of the [CL]/[C] from 100 to 800 produced PCL with relatively the same molecular weight indicative of a catalyst behavior. The appearance of induction period in kinetic plots strengthens the fact that these complexes are catalysts rather than initiators. MALDI-TOF MS and 1H NMR data show di-hydroxy end groups, which support the coordination mechanism rather than insertion mechanism. To understand the broad PDIs obtained for some of the polymer, the electronic properties of the zinc complexes were investigated using cyclic voltammetry. The results show that the zinc complexes containing amine based ligands are highly electrophilic therefore making them unstable, hence the broad PDIs observed for zinc complexes containing amine based ligands. Among the eight complexes investigated, complex 7 is the most active catalyst with kp value of 1.18 × 10−7 h−1 mol−1 at 110 °C. , Original publication is available at http://dx.doi.org/10.1016/j.poly.2015.02.007
- Full Text: false
- Authors: Obuah, Collins , Lochee, Yemanlall , Jordaan, Johan H L , Otto, Daniel P , Nyokong, Tebello , Darkwa, James
- Language: English
- Type: Article
- Identifier: vital:7264 , http://hdl.handle.net/10962/d1020273
- Description: The reaction of Zn(OAc)2 and C6H5COOH or 3,5-NO2-C6H3COOH with 3-ferrocenylpyrazolyl-methylenepyridine (L1), 3-ferrocenyl-5-methylpyrazolyl-methylenepyridine (L2), 3-ferrocenylpyrazolyl-ethylamine (L3) and 3-ferrocenyl-5-pyrazolyl-ethylamine (L4) afford the corresponding complexes [Zn(C6H5COO)2(L1)] (1), [Zn(C6H5COO)2(L2)] (2), [Zn(3,5-NO2-C6H3COO)2(L1)] (3), [Zn(3,5-NO2-C6H3COO)2(L2)] (4), [Zn(C6H5COO)2(L3)] (5), [Zn(C6H5COO)2(L4)] (6), [Zn(3,5-NO2-C6H3COO)2(L3)] (7) and [Zn(3,5-NO2-C6H3COO)2(L4)] (8). These complexes behave as catalysts for the ring opening polymerization of ɛ-caprolactone to produce polymers with molecular weight that range from 1480 to 7080 g mol−1 and exhibited moderate to broad PDIs. Evidence of these complexes acting as catalysts was obtained from both the polymerization data and kinetic studies. The polymerization data show that variation of the [CL]/[C] from 100 to 800 produced PCL with relatively the same molecular weight indicative of a catalyst behavior. The appearance of induction period in kinetic plots strengthens the fact that these complexes are catalysts rather than initiators. MALDI-TOF MS and 1H NMR data show di-hydroxy end groups, which support the coordination mechanism rather than insertion mechanism. To understand the broad PDIs obtained for some of the polymer, the electronic properties of the zinc complexes were investigated using cyclic voltammetry. The results show that the zinc complexes containing amine based ligands are highly electrophilic therefore making them unstable, hence the broad PDIs observed for zinc complexes containing amine based ligands. Among the eight complexes investigated, complex 7 is the most active catalyst with kp value of 1.18 × 10−7 h−1 mol−1 at 110 °C. , Original publication is available at http://dx.doi.org/10.1016/j.poly.2015.02.007
- Full Text: false
A comparative photophysicochemical study of phthalocyanines encapsulated in core–shell silica nanoparticles
- Fashina, Adedayo, Amuhaya, Edith, Nyokong, Tebello
- Authors: Fashina, Adedayo , Amuhaya, Edith , Nyokong, Tebello
- Language: English
- Type: text
- Identifier: vital:7271 , http://hdl.handle.net/10962/d1020286 , Original publication is available at http://dx.doi.org/10.1016/j.saa.2014.08.062
- Full Text: false
- Authors: Fashina, Adedayo , Amuhaya, Edith , Nyokong, Tebello
- Language: English
- Type: text
- Identifier: vital:7271 , http://hdl.handle.net/10962/d1020286 , Original publication is available at http://dx.doi.org/10.1016/j.saa.2014.08.062
- Full Text: false
Clinical psychologists' perceived barriers to the provision of psychological services for people with first-episode schizophrenia in urban public health care settings
- Barnwell, Garret Christopher
- Authors: Barnwell, Garret Christopher
- Subjects: Clinical psychologists -- South Africa -- Nelson Mandela Bay Municipality , Schizophrenia -- Treatment -- South Africa -- Nelson Mandela Bay Municipality , Urban health -- South Africa -- Nelson Mandela Bay Municipality , Health facilities -- South Africa -- Nelson Mandela Bay Municipality -- Administration
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:10083 , http://hdl.handle.net/10948/d1020304
- Description: This study explored and described the perception of clinical psychologists regarding thebarriers to the provision of psychological services in urban public health settings for people with first-episode schizophrenia. The qualitative research study utilised an explorative, descriptive interpretive research design. Purposive sampling was utilised to gain access to clinical psychologists, who had at least two years of public health experience working with people recently diagnosed with schizophrenia. Data was gathered from 11 participants from the Nelson Mandela Bay Health District of the Eastern Cape by means of in-depth interviews that were conducted in English by the researcher until data saturation had occurred. A computer-assisted qualitative thematic analysis of the collected data was conducted using NVIVO software. The findings have been categorised according to three broad domains: 1)contextual barriers 2)health care system-related barriers and 3)first-episode schizophrenia syndrome-related barriers. Several specific sub-themes were identified for each of these main domains allowing for recommendations and suggestions to be provided for attending to and overcoming these perceived barriers.
- Full Text:
- Authors: Barnwell, Garret Christopher
- Subjects: Clinical psychologists -- South Africa -- Nelson Mandela Bay Municipality , Schizophrenia -- Treatment -- South Africa -- Nelson Mandela Bay Municipality , Urban health -- South Africa -- Nelson Mandela Bay Municipality , Health facilities -- South Africa -- Nelson Mandela Bay Municipality -- Administration
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:10083 , http://hdl.handle.net/10948/d1020304
- Description: This study explored and described the perception of clinical psychologists regarding thebarriers to the provision of psychological services in urban public health settings for people with first-episode schizophrenia. The qualitative research study utilised an explorative, descriptive interpretive research design. Purposive sampling was utilised to gain access to clinical psychologists, who had at least two years of public health experience working with people recently diagnosed with schizophrenia. Data was gathered from 11 participants from the Nelson Mandela Bay Health District of the Eastern Cape by means of in-depth interviews that were conducted in English by the researcher until data saturation had occurred. A computer-assisted qualitative thematic analysis of the collected data was conducted using NVIVO software. The findings have been categorised according to three broad domains: 1)contextual barriers 2)health care system-related barriers and 3)first-episode schizophrenia syndrome-related barriers. Several specific sub-themes were identified for each of these main domains allowing for recommendations and suggestions to be provided for attending to and overcoming these perceived barriers.
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Colonial tales, alter-narratives and the enduring value of anthropology
- Authors: Boswell, Rose
- Subjects: Anthrology , Oral tradition , f-sa
- Language: English
- Type: text , Lectures
- Identifier: http://hdl.handle.net/10948/20989 , vital:29425
- Description: Stories and story-telling are fundamental to human beings. What stories do we choose to tell, hear and relate? From childhood through to adulthood, stories and story-telling provide social content, example, advice, therapy, continuity, connection and entertainment. Story-telling is also a space for hidden resistance, embodiment and the invocation of rank. Accompanied by song and dance, those intangible heritages which must remain dynamic to endure, stories facilitate an aural and oral community that engenders its own understanding of time, place and identity. In anthropology, the study of humanity in all its complexities, there is the collection, collation and retelling of stories for audiences who would otherwise not understand or seek to essentialise those deemed ‗other‘. In this inaugural lecture I focus on the value of stories gathered from anthropological field research in the southwest Indian Ocean Islands. The stories (often constitutive of a multiply-situated self), shed light on the finer details of gendered, ethnic and raced existence in the island communities. They also offer deep insight into the nature and possible ‗evolutions‘ of contemporary societies. Finally, I suggest that alter-narratives, those stories rarely told, provide access not only to multiple worlds, they are part of an aural epistemology which might lead to alternative ways of connecting with others and thereby conceptualising and articulating identity in our contemporary global society.
- Full Text:
- Authors: Boswell, Rose
- Subjects: Anthrology , Oral tradition , f-sa
- Language: English
- Type: text , Lectures
- Identifier: http://hdl.handle.net/10948/20989 , vital:29425
- Description: Stories and story-telling are fundamental to human beings. What stories do we choose to tell, hear and relate? From childhood through to adulthood, stories and story-telling provide social content, example, advice, therapy, continuity, connection and entertainment. Story-telling is also a space for hidden resistance, embodiment and the invocation of rank. Accompanied by song and dance, those intangible heritages which must remain dynamic to endure, stories facilitate an aural and oral community that engenders its own understanding of time, place and identity. In anthropology, the study of humanity in all its complexities, there is the collection, collation and retelling of stories for audiences who would otherwise not understand or seek to essentialise those deemed ‗other‘. In this inaugural lecture I focus on the value of stories gathered from anthropological field research in the southwest Indian Ocean Islands. The stories (often constitutive of a multiply-situated self), shed light on the finer details of gendered, ethnic and raced existence in the island communities. They also offer deep insight into the nature and possible ‗evolutions‘ of contemporary societies. Finally, I suggest that alter-narratives, those stories rarely told, provide access not only to multiple worlds, they are part of an aural epistemology which might lead to alternative ways of connecting with others and thereby conceptualising and articulating identity in our contemporary global society.
- Full Text:
Comparative electrocatalytic studies of nanocomposites of mixed and covalently linked multiwalled carbon nanotubes and 4-(4,6-diaminopyrimidin-2-ylthio) phthalocyaninato cobalt(II)
- Nyoni, Stephen, Nyokong, Tebello
- Authors: Nyoni, Stephen , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7285 , http://hdl.handle.net/10962/d1020332
- Description: Electrocatalytic behavior of 4-(4,6-diaminopyrimidin-2-ylthio) phthalocyaninato cobalt(II) (CoPyPc) when mixed or covalently mixed to multiwalled carbon nanotubes (MWCNTs) is reported. Infra-red spectroscopy was used to confirm amide linkage of the covalently linked nanocomposite. Rotating disk electrode (RDE) and cyclic (CV) voltammetry studies were used for the electrochemical characterization of the prepared phthalocyanine and MWCNT nanocomposite. The electrocatalytic effects of the nanocomposites of the cobalt phthalocyanine derivative were then investigated towards l-cysteine oxidation using both RDE and CV experiments, and the electrocatalytic performance of the covalently linked cobalt phthalocyanine-MWCNT was found to be superior over the mixed nanocomposite. , Original publication is available at http://dx.doi.org/10.1016/j.poly.2015.05.038
- Full Text: false
- Authors: Nyoni, Stephen , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7285 , http://hdl.handle.net/10962/d1020332
- Description: Electrocatalytic behavior of 4-(4,6-diaminopyrimidin-2-ylthio) phthalocyaninato cobalt(II) (CoPyPc) when mixed or covalently mixed to multiwalled carbon nanotubes (MWCNTs) is reported. Infra-red spectroscopy was used to confirm amide linkage of the covalently linked nanocomposite. Rotating disk electrode (RDE) and cyclic (CV) voltammetry studies were used for the electrochemical characterization of the prepared phthalocyanine and MWCNT nanocomposite. The electrocatalytic effects of the nanocomposites of the cobalt phthalocyanine derivative were then investigated towards l-cysteine oxidation using both RDE and CV experiments, and the electrocatalytic performance of the covalently linked cobalt phthalocyanine-MWCNT was found to be superior over the mixed nanocomposite. , Original publication is available at http://dx.doi.org/10.1016/j.poly.2015.05.038
- Full Text: false
Effects of Redox Mediators on the Catalytic Activity of Iron Porphyrins towards Oxygen Reduction in Acidic Media
- He, Qinggang, Wu, Gang, Liu, Ke, Khene, M Samson, Li, Qing, Mugadza, Tawanda, Deunf, Elise, Nyokong, Tebello, Chen, Shaowei W
- Authors: He, Qinggang , Wu, Gang , Liu, Ke , Khene, M Samson , Li, Qing , Mugadza, Tawanda , Deunf, Elise , Nyokong, Tebello , Chen, Shaowei W
- Language: English
- Type: Article
- Identifier: vital:7291 , http://hdl.handle.net/10962/d1020354
- Description: The effects of different redox mediators on the oxygen reduction reaction (ORR) catalyzed by an iron porphyrin complex, iron(III) meso-tetra(N-methyl-4-pyridyl)porphine chloride [FeIIITMPyP], in 0.1 M triflic acid were investigated by cyclic voltammetry (CV) and spectroelectrochemistry in conjunction with density functional theory (DFT) calculations. The formal potentials of the FeIIITMPyP catalyst and the redox mediators, as well as the half-wave potentials for the ORR, were determined by CV in the absence and presence of oxygen in acidic solutions. UV/Vis spectroscopic and spectroelectrochemical studies confirmed that only the 2,2′-azino-bis(3-ethylbenzothiazioline-6-sulfonic acid)diammonium salt (C18H24N6O6S4) showed effective interactions with FeIIITMPyP during the ORR. DFT calculations suggested strong interaction between FeIIITMPyP and the C18H24N6O6S4 redox mediator. The redox mediator caused lengthening of the dioxygen iron bond, which thus suggested easier dioxygen reduction. Consistent results were observed in electrochemical impedance spectroscopic measurements for which the electron-transfer kinetics were also evaluated. , Original publication is available at http://dx.doi.org/10.1002/celc.201402054
- Full Text: false
- Authors: He, Qinggang , Wu, Gang , Liu, Ke , Khene, M Samson , Li, Qing , Mugadza, Tawanda , Deunf, Elise , Nyokong, Tebello , Chen, Shaowei W
- Language: English
- Type: Article
- Identifier: vital:7291 , http://hdl.handle.net/10962/d1020354
- Description: The effects of different redox mediators on the oxygen reduction reaction (ORR) catalyzed by an iron porphyrin complex, iron(III) meso-tetra(N-methyl-4-pyridyl)porphine chloride [FeIIITMPyP], in 0.1 M triflic acid were investigated by cyclic voltammetry (CV) and spectroelectrochemistry in conjunction with density functional theory (DFT) calculations. The formal potentials of the FeIIITMPyP catalyst and the redox mediators, as well as the half-wave potentials for the ORR, were determined by CV in the absence and presence of oxygen in acidic solutions. UV/Vis spectroscopic and spectroelectrochemical studies confirmed that only the 2,2′-azino-bis(3-ethylbenzothiazioline-6-sulfonic acid)diammonium salt (C18H24N6O6S4) showed effective interactions with FeIIITMPyP during the ORR. DFT calculations suggested strong interaction between FeIIITMPyP and the C18H24N6O6S4 redox mediator. The redox mediator caused lengthening of the dioxygen iron bond, which thus suggested easier dioxygen reduction. Consistent results were observed in electrochemical impedance spectroscopic measurements for which the electron-transfer kinetics were also evaluated. , Original publication is available at http://dx.doi.org/10.1002/celc.201402054
- Full Text: false
Effects of ZnO nanohexagons and nanorods on the fluorescence behavior of metallophthalocyanines
- D’Souza, Sarah, Moeno, Sharon, Nyokong, Tebello
- Authors: D’Souza, Sarah , Moeno, Sharon , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7263 , http://hdl.handle.net/10962/d1020272
- Description: This paper looks at the fluorescence behavior of zinc phthalocyanines: 2,(3),9(10),16(17),23(24)-tetrakis-(mercaptoacetic acid phthalocyaninato) zinc(II) (ZnTMAAPc), 2,(3),9(10),16(17),23(24)-tetrakis-(mercaptopropanoic acid phthalocyaninato) zinc(II) (ZnTMPAPc) and (OH)AlPcSmix (the latter contains a mixture of the di-, tri- and tetra-sulfonated derivatives with an average of three sulfonated groups per molecule) in the presence of ZnO nanoparticles. Fluorescence lifetimes of Pc complexes generally decreased in the presence of ZnO nanoparticles, with generally longer lifetimes for ZnO nanohexagons compared to ZnO nanorods. , Original publication is available at http://dx.doi.org/10.1016/j.poly.2014.09.012
- Full Text: false
- Authors: D’Souza, Sarah , Moeno, Sharon , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7263 , http://hdl.handle.net/10962/d1020272
- Description: This paper looks at the fluorescence behavior of zinc phthalocyanines: 2,(3),9(10),16(17),23(24)-tetrakis-(mercaptoacetic acid phthalocyaninato) zinc(II) (ZnTMAAPc), 2,(3),9(10),16(17),23(24)-tetrakis-(mercaptopropanoic acid phthalocyaninato) zinc(II) (ZnTMPAPc) and (OH)AlPcSmix (the latter contains a mixture of the di-, tri- and tetra-sulfonated derivatives with an average of three sulfonated groups per molecule) in the presence of ZnO nanoparticles. Fluorescence lifetimes of Pc complexes generally decreased in the presence of ZnO nanoparticles, with generally longer lifetimes for ZnO nanohexagons compared to ZnO nanorods. , Original publication is available at http://dx.doi.org/10.1016/j.poly.2014.09.012
- Full Text: false
Electrocatalytic activity of bimetallic Au–Pd nanoparticles in the presence of cobalt tetraaminophthalocyanine
- Maringa, Audacity, Mashazi, Philani N, Nyokong, Tebello
- Authors: Maringa, Audacity , Mashazi, Philani N , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7245 , http://hdl.handle.net/10962/d1020250
- Description: Au and Pd nanoparticles were individually or together electrodeposited on top of polymerized cobalt tetraaminophthalocyanine (poly-CoTAPc). When Pd and Au nanoparticles are co-deposited together, the electrode is denoted as Au–Pd (co-deposited)/poly-CoTAPc-GCE. X-ray photoelectron spectroscopy (XPS) was used to show the successful deposition of AuNPs, PdNPs and Au–Pd (co-deposited). The scanning electrochemical microscopy showed that Au–Pd (co-deposited)/poly-CoTAPc-GCE (with current range of 9.5–13.5 μA) was more conducting than Au–Pd (co-deposited)-GCE (with current range of 8–12 μA). Electrochemical impedance spectroscopy (EIS) showed that there was less resistance to charge transfer for Au–Pd (co-deposited)/poly-CoTAPc-GCE compared to the rest of the electrodes. Au–Pd (co-deposited)/poly-CoTAPc-GCE showed the best activity for the electrooxidation of hydrazine in terms of limit of detection (0.5 μM), hence shows promise as an electrocatalyst for electrooxidation of hydrazine. , Original publication is available at http://dx.doi.org/10.1016/j.jcis.2014.10.056
- Full Text: false
- Authors: Maringa, Audacity , Mashazi, Philani N , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7245 , http://hdl.handle.net/10962/d1020250
- Description: Au and Pd nanoparticles were individually or together electrodeposited on top of polymerized cobalt tetraaminophthalocyanine (poly-CoTAPc). When Pd and Au nanoparticles are co-deposited together, the electrode is denoted as Au–Pd (co-deposited)/poly-CoTAPc-GCE. X-ray photoelectron spectroscopy (XPS) was used to show the successful deposition of AuNPs, PdNPs and Au–Pd (co-deposited). The scanning electrochemical microscopy showed that Au–Pd (co-deposited)/poly-CoTAPc-GCE (with current range of 9.5–13.5 μA) was more conducting than Au–Pd (co-deposited)-GCE (with current range of 8–12 μA). Electrochemical impedance spectroscopy (EIS) showed that there was less resistance to charge transfer for Au–Pd (co-deposited)/poly-CoTAPc-GCE compared to the rest of the electrodes. Au–Pd (co-deposited)/poly-CoTAPc-GCE showed the best activity for the electrooxidation of hydrazine in terms of limit of detection (0.5 μM), hence shows promise as an electrocatalyst for electrooxidation of hydrazine. , Original publication is available at http://dx.doi.org/10.1016/j.jcis.2014.10.056
- Full Text: false
Electrode Modification Using Alkynyl Substituted Fe(II) Phthalocyanine via Electrografting and Click Chemistry for Electrocatalysis
- Nxele, Siphesihle R, Mashazi, Philani N, Nyokong, Tebello
- Authors: Nxele, Siphesihle R , Mashazi, Philani N , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7284 , http://hdl.handle.net/10962/d1020329
- Description: In this work, tetrakis(5-hexyn-oxy)Fe(II) phthalocyanine was synthesised in order to perform a click reaction between the terminal alkyne groups and an azide group on a glassy carbon electrode (GCE) surface. An azide group was formed on the electrode surface following electrografting using 4-azidobenzene diazonium tetrafluoroborate by electrochemical reduction. The Cu(I) catalyzed alkyne-azide Huisgen cycloaddition reaction was then employed in order to react the terminal alkyne groups on the phthalocyanine with the azide groups on the GCE surface. The modified electrode was employed to catalyse the oxidation of hydrazine. The electrode showed good electrocatalytic ability towards the detection of hydrazine with a sensitivity of 15.38 µA mM−1 and a limit of detection of 1.09 µM. , Original publication is available at http://dx.doi.org/10.1002/elan.201500212
- Full Text: false
- Authors: Nxele, Siphesihle R , Mashazi, Philani N , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7284 , http://hdl.handle.net/10962/d1020329
- Description: In this work, tetrakis(5-hexyn-oxy)Fe(II) phthalocyanine was synthesised in order to perform a click reaction between the terminal alkyne groups and an azide group on a glassy carbon electrode (GCE) surface. An azide group was formed on the electrode surface following electrografting using 4-azidobenzene diazonium tetrafluoroborate by electrochemical reduction. The Cu(I) catalyzed alkyne-azide Huisgen cycloaddition reaction was then employed in order to react the terminal alkyne groups on the phthalocyanine with the azide groups on the GCE surface. The modified electrode was employed to catalyse the oxidation of hydrazine. The electrode showed good electrocatalytic ability towards the detection of hydrazine with a sensitivity of 15.38 µA mM−1 and a limit of detection of 1.09 µM. , Original publication is available at http://dx.doi.org/10.1002/elan.201500212
- Full Text: false