Stephen's garden, Port Elizabeth
- Authors: Skead, C J (Cuthbert John)
- Date: 1996-01-09
- Subjects: Gardens -- South Africa -- Eastern Cape , Plants -- South Africa -- Eastern Cape
- Type: still image
- Identifier: vital:13109 , http://hdl.handle.net/10962/d1016745
- Description: Stephen's garden.
- Full Text: false
- Date Issued: 1996-01-09
- Authors: Skead, C J (Cuthbert John)
- Date: 1996-01-09
- Subjects: Gardens -- South Africa -- Eastern Cape , Plants -- South Africa -- Eastern Cape
- Type: still image
- Identifier: vital:13109 , http://hdl.handle.net/10962/d1016745
- Description: Stephen's garden.
- Full Text: false
- Date Issued: 1996-01-09
Stephen's garden, Port Elizabeth
- Authors: Skead, C J (Cuthbert John)
- Date: 1996-01-13
- Subjects: Gardens -- South Africa -- Eastern Cape , Plants -- South Africa -- Eastern Cape
- Type: still image
- Identifier: vital:13110 , http://hdl.handle.net/10962/d1016746
- Description: Stephen's garden.
- Full Text: false
- Date Issued: 1996-01-13
- Authors: Skead, C J (Cuthbert John)
- Date: 1996-01-13
- Subjects: Gardens -- South Africa -- Eastern Cape , Plants -- South Africa -- Eastern Cape
- Type: still image
- Identifier: vital:13110 , http://hdl.handle.net/10962/d1016746
- Description: Stephen's garden.
- Full Text: false
- Date Issued: 1996-01-13
Improved l-cysteine electrocatalysis through a sequential drop dry technique using multi-walled carbon nanotubes and cobalt tetraaminophthalocyanine conjugates
- Nyoni, Stephen, Mugadza, Tawanda, Nyokong, Tebello
- Authors: Nyoni, Stephen , Mugadza, Tawanda , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7308 , http://hdl.handle.net/10962/d1020385
- Description: Voltammetry, chronoamperometry, scanning electrochemical microscopy and electrochemical impedance spectroscopy methods are used for characterization of a glassy carbon electrode modified with multi-walled carbon nanotubes (MWCNTs)–cobalt tetraaminophthalocyanine (CoTAPc) mixture or sequential drop dry modification technique whereby the MWCNTs are first placed on to the electrode followed by CoTAPc. The sequential drop dry CoTAPc–MWCNTs modified surface gave better catalytic responses with a catalytic rate constant of 2.2 × 105 M−1 s−1, apparent electron transfer rate constant of 0.073 cm s−1, and a limit of detection of 2.8 × 10−7 M. Scanning electrochemical microscopy (SECM) surface characterization (topography and reactivity) further gave proof the better catalytic perfomance of the sequential drop dry CoTAPc–MWCNTs modified surface. , Original publication is available at http://dx.doi.org/10.1016/j.electacta.2013.10.023
- Full Text: false
- Authors: Nyoni, Stephen , Mugadza, Tawanda , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7308 , http://hdl.handle.net/10962/d1020385
- Description: Voltammetry, chronoamperometry, scanning electrochemical microscopy and electrochemical impedance spectroscopy methods are used for characterization of a glassy carbon electrode modified with multi-walled carbon nanotubes (MWCNTs)–cobalt tetraaminophthalocyanine (CoTAPc) mixture or sequential drop dry modification technique whereby the MWCNTs are first placed on to the electrode followed by CoTAPc. The sequential drop dry CoTAPc–MWCNTs modified surface gave better catalytic responses with a catalytic rate constant of 2.2 × 105 M−1 s−1, apparent electron transfer rate constant of 0.073 cm s−1, and a limit of detection of 2.8 × 10−7 M. Scanning electrochemical microscopy (SECM) surface characterization (topography and reactivity) further gave proof the better catalytic perfomance of the sequential drop dry CoTAPc–MWCNTs modified surface. , Original publication is available at http://dx.doi.org/10.1016/j.electacta.2013.10.023
- Full Text: false
Stephen and Charles in Spungfield Thooi river, Natal
- Subjects: Zululand -- History -- Photographs Zulu (African people) -- Social life and customs Natal (South Africa) -- History -- Photographs Kwamagwaza (South Africa) -- History -- Photographs Etalaneni (South Africa) -- History -- Photographs Nottingham Mission (South Africa) -- History -- Photographs Mooirivier (South Africa) -- History -- Photographs Ladysmith (South Africa) -- History -- Photographs
- Type: Image
- Identifier: http://hdl.handle.net/10962/32289 , vital:24029 , PIC/A 4326 , This image is held at the Cory Library for Humanities Research at Rhodes University. For further information contact cory@ru.ac.za. The digitisation of this image was made possible through a generous grant received from the Andrew W. Mellon Foundation 2014-2017.
- Description: Album relating to the Zulu people of Zululand in the Natal Province during the years 1930-31 and 1934, taken at various places, including Chads College, Ladysmith; Springfield, Mooirivier; the Leytown Pohams House ("Hemrock"), Nottingham Road; Umlazi Mission; Etalaneni; Kwamagwaza; on the way to Biyela : mainly photographs, some original, some photocopies, with descriptive text in some cases / photographer unknown. 50 Hhotographs in one album : b+w (some sepia), 22 cm x 10 cm or less.
- Full Text: false
- Subjects: Zululand -- History -- Photographs Zulu (African people) -- Social life and customs Natal (South Africa) -- History -- Photographs Kwamagwaza (South Africa) -- History -- Photographs Etalaneni (South Africa) -- History -- Photographs Nottingham Mission (South Africa) -- History -- Photographs Mooirivier (South Africa) -- History -- Photographs Ladysmith (South Africa) -- History -- Photographs
- Type: Image
- Identifier: http://hdl.handle.net/10962/32289 , vital:24029 , PIC/A 4326 , This image is held at the Cory Library for Humanities Research at Rhodes University. For further information contact cory@ru.ac.za. The digitisation of this image was made possible through a generous grant received from the Andrew W. Mellon Foundation 2014-2017.
- Description: Album relating to the Zulu people of Zululand in the Natal Province during the years 1930-31 and 1934, taken at various places, including Chads College, Ladysmith; Springfield, Mooirivier; the Leytown Pohams House ("Hemrock"), Nottingham Road; Umlazi Mission; Etalaneni; Kwamagwaza; on the way to Biyela : mainly photographs, some original, some photocopies, with descriptive text in some cases / photographer unknown. 50 Hhotographs in one album : b+w (some sepia), 22 cm x 10 cm or less.
- Full Text: false
An analysis of the contribution of four painters to the development of contemporary Zambian painting from 1950-1997
- Authors: Setti, Godfrey
- Date: 2001
- Subjects: Painting -- Zambia , Art, Zambian -- 20th Century , Painting -- 20th century -- Zambia
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2422 , http://hdl.handle.net/10962/d1002218 , Painting -- Zambia , Art, Zambian -- 20th Century , Painting -- 20th century -- Zambia
- Description: This study presents an analysis of the contribution of four painters to the development of contemporary Zambian painting, from 1950 to 1997. This is preceded by a brief history of Zambian painting, including Bushmen rock painting and early Bantu art, which is followed by an account of the way western influence, introduced by the white man, started changing the style of painting in the country as it began to affect indigenous artists. In the work of artists who began painting from about 1900 to 1950, both western and traditional stylistic influences can be seen. While the painters whose work is analysed in this thesis had some knowledge of Zambian art before 1950, they were mainly influenced by western ideas of painting. From a list of more than ten painters ofthis period from 1950 to 1997, I selected: Gabriel Ellison, Cynthia Zukas, Hemy Tayali and Stephen Kappata because I know them personally and therefore had access to them and their work, which facilitated my analysis of their work and its contribution to Zambian painting. This analysis takes the form of four chapters, one for each artist, in which relevant biographical and educational background is outlined, followed by an analysis of examples of\vork. Finally, ways in which each painter, through exposure to the Zambian public and artistic community, contributed to further development in Zambian painting, are emphasised.
- Full Text:
- Date Issued: 2001
- Authors: Setti, Godfrey
- Date: 2001
- Subjects: Painting -- Zambia , Art, Zambian -- 20th Century , Painting -- 20th century -- Zambia
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2422 , http://hdl.handle.net/10962/d1002218 , Painting -- Zambia , Art, Zambian -- 20th Century , Painting -- 20th century -- Zambia
- Description: This study presents an analysis of the contribution of four painters to the development of contemporary Zambian painting, from 1950 to 1997. This is preceded by a brief history of Zambian painting, including Bushmen rock painting and early Bantu art, which is followed by an account of the way western influence, introduced by the white man, started changing the style of painting in the country as it began to affect indigenous artists. In the work of artists who began painting from about 1900 to 1950, both western and traditional stylistic influences can be seen. While the painters whose work is analysed in this thesis had some knowledge of Zambian art before 1950, they were mainly influenced by western ideas of painting. From a list of more than ten painters ofthis period from 1950 to 1997, I selected: Gabriel Ellison, Cynthia Zukas, Hemy Tayali and Stephen Kappata because I know them personally and therefore had access to them and their work, which facilitated my analysis of their work and its contribution to Zambian painting. This analysis takes the form of four chapters, one for each artist, in which relevant biographical and educational background is outlined, followed by an analysis of examples of\vork. Finally, ways in which each painter, through exposure to the Zambian public and artistic community, contributed to further development in Zambian painting, are emphasised.
- Full Text:
- Date Issued: 2001
Palace Courtyards in Iléṣà: a melting point of traditional Yorùbá architecture
- Fọlárànmí, Stephen, Adémúlẹyá, Babásẹhìndè
- Authors: Fọlárànmí, Stephen , Adémúlẹyá, Babásẹhìndè
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/145873 , vital:38474 , https://news.clas.ufl.edu/palace-courtyards-in-ile%E1%B9%A3a-a-melting-point-of-traditional-yoruba-architecture/
- Description: The Yorùbá courtyard is an important architectural space in traditional Yorùbá architecture that has not received adequate scholarly attention. This paper examines the courtyards in the palace of certain chiefs and Ọwá Obòkun in Iléṣà, in southwest Nigeria. Fieldwork identified about ten courtyards in the palace of the Ọwá, four in the Rísàwè palace, and two in the palaces of the Léjọkà and Ọdọlé of Iléṣà. It uses these courtyards as models for courtyards in Yorùbá architecture. The study revealed that most of the courtyards in the Ọwá’s palace are generally not used for one specific function, though some are used mainly for religious purposes. The courtyards in the palaces of the chiefs are more functional, and better maintained than those of the Ọwá’s palace. The paper concludes that—considering their ancient and social function—the courtyards form a melting point within Yorùbá architecture. It suggests that efforts be made to ensure that the existing courtyards in these palaces are designated as landmark architecture and properly cared for to serve as tourist attractions.
- Full Text:
- Date Issued: 2018
- Authors: Fọlárànmí, Stephen , Adémúlẹyá, Babásẹhìndè
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/145873 , vital:38474 , https://news.clas.ufl.edu/palace-courtyards-in-ile%E1%B9%A3a-a-melting-point-of-traditional-yoruba-architecture/
- Description: The Yorùbá courtyard is an important architectural space in traditional Yorùbá architecture that has not received adequate scholarly attention. This paper examines the courtyards in the palace of certain chiefs and Ọwá Obòkun in Iléṣà, in southwest Nigeria. Fieldwork identified about ten courtyards in the palace of the Ọwá, four in the Rísàwè palace, and two in the palaces of the Léjọkà and Ọdọlé of Iléṣà. It uses these courtyards as models for courtyards in Yorùbá architecture. The study revealed that most of the courtyards in the Ọwá’s palace are generally not used for one specific function, though some are used mainly for religious purposes. The courtyards in the palaces of the chiefs are more functional, and better maintained than those of the Ọwá’s palace. The paper concludes that—considering their ancient and social function—the courtyards form a melting point within Yorùbá architecture. It suggests that efforts be made to ensure that the existing courtyards in these palaces are designated as landmark architecture and properly cared for to serve as tourist attractions.
- Full Text:
- Date Issued: 2018
Wellcome to ISER 2011 Summer School
- Authors: Badat, Saleem
- Date: 2011-09-12
- Language: English
- Type: Text
- Identifier: vital:7800 , http://hdl.handle.net/10962/d1015993
- Full Text:
- Date Issued: 2011-09-12
- Authors: Badat, Saleem
- Date: 2011-09-12
- Language: English
- Type: Text
- Identifier: vital:7800 , http://hdl.handle.net/10962/d1015993
- Full Text:
- Date Issued: 2011-09-12
Philip and Mary Jourdan with Jocelyn, Stephen and Jane
- Subjects: Class reunions -- South Africa -- Grahamstown -- Photographs Grahamstown Teachers' Training College (South Africa) -- Photographs
- Type: Image
- Identifier: http://hdl.handle.net/10962/34193 , vital:24221 , This image is held at the Cory Library for Humanities Research at Rhodes University. For further information contact cory@ru.ac.za. The digitisation of this image was made possible through a generous grant received from the Andrew W. Mellon Foundation 2014-2017. , PIC/A 2897_156
- Description: Photograph of Philip and Mary Jourdan (née Travers-Jackson) with their children, Jocelyn, Stephen and Jane , Leila Kerr (Linington) (Donor)
- Full Text: false
- Subjects: Class reunions -- South Africa -- Grahamstown -- Photographs Grahamstown Teachers' Training College (South Africa) -- Photographs
- Type: Image
- Identifier: http://hdl.handle.net/10962/34193 , vital:24221 , This image is held at the Cory Library for Humanities Research at Rhodes University. For further information contact cory@ru.ac.za. The digitisation of this image was made possible through a generous grant received from the Andrew W. Mellon Foundation 2014-2017. , PIC/A 2897_156
- Description: Photograph of Philip and Mary Jourdan (née Travers-Jackson) with their children, Jocelyn, Stephen and Jane , Leila Kerr (Linington) (Donor)
- Full Text: false
Whitey Mkosana Kuruman playing his alto sax at St Stephen's hall in Port Elizabeth..
- Authors: Kuruman Mkosana Whitey
- Date: 19??
- Subjects: UNCATALOGUED
- Type: Image
- Identifier: http://hdl.handle.net/10962/222660 , vital:48899 , DTC-030
- Description: One of the origional Soul Jazzmen and ex-King Cole baseman, Whitey Mkosana Kuruman playing his alto sax at St Stephen's hall in Port Elizabeth. , Use of this resource is governed by the terms and conditions of the Creative Commons "Attribution-NonCommercial-ShareAlike" License (http://creativecommons.org/licenses/by-nc-sa/2.0/) (NEVER CAHNGE THIS FIELD)
- Full Text: false
- Date Issued: 19??
- Authors: Kuruman Mkosana Whitey
- Date: 19??
- Subjects: UNCATALOGUED
- Type: Image
- Identifier: http://hdl.handle.net/10962/222660 , vital:48899 , DTC-030
- Description: One of the origional Soul Jazzmen and ex-King Cole baseman, Whitey Mkosana Kuruman playing his alto sax at St Stephen's hall in Port Elizabeth. , Use of this resource is governed by the terms and conditions of the Creative Commons "Attribution-NonCommercial-ShareAlike" License (http://creativecommons.org/licenses/by-nc-sa/2.0/) (NEVER CAHNGE THIS FIELD)
- Full Text: false
- Date Issued: 19??
Stephen, Jocelyn and Jane Jourdan
- Subjects: Class reunions -- South Africa -- Grahamstown -- Photographs Grahamstown Teachers' Training College (South Africa) -- Photographs
- Type: Image
- Identifier: http://hdl.handle.net/10962/34663 , vital:24268 , This image is held at the Cory Library for Humanities Research at Rhodes University. For further information contact cory@ru.ac.za. The digitisation of this image was made possible through a generous grant received from the Andrew W. Mellon Foundation 2014-2017. , PIC/A 2897_188
- Description: Photograph of Stephen, Jocelyn and Jane Jourdan, the children of Philip and Mary Jourdan (née Travers-Jackson) , Leila Kerr (Linington) (Donor)
- Full Text: false
- Subjects: Class reunions -- South Africa -- Grahamstown -- Photographs Grahamstown Teachers' Training College (South Africa) -- Photographs
- Type: Image
- Identifier: http://hdl.handle.net/10962/34663 , vital:24268 , This image is held at the Cory Library for Humanities Research at Rhodes University. For further information contact cory@ru.ac.za. The digitisation of this image was made possible through a generous grant received from the Andrew W. Mellon Foundation 2014-2017. , PIC/A 2897_188
- Description: Photograph of Stephen, Jocelyn and Jane Jourdan, the children of Philip and Mary Jourdan (née Travers-Jackson) , Leila Kerr (Linington) (Donor)
- Full Text: false
Biochemical characterisation and small molecule modulation of the interaction between two cytosolic Hsp70s from Trypanosoma brucei and potential co-chaperones
- Authors: Bentley, Stephen John
- Date: 2018
- Subjects: Uncatalogued
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/63402 , vital:28407
- Description: Expected release date-April 2019
- Full Text:
- Date Issued: 2018
- Authors: Bentley, Stephen John
- Date: 2018
- Subjects: Uncatalogued
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/63402 , vital:28407
- Description: Expected release date-April 2019
- Full Text:
- Date Issued: 2018
Quality assessment of information systems in SMEs: a study of Eldoret Town in Kenya
- Authors: Ndiege, Joshua Rumo Arongo
- Date: 2010
- Subjects: Small business -- Kenya , Financial institutions -- Kenya , Small business -- Kenya -- Data processing , Information technology -- Kenya -- Evaluation
- Language: English
- Type: Thesis , Masters , MCom (Information Systems)
- Identifier: vital:11132 , http://hdl.handle.net/10353/d1000973 , Small business -- Kenya , Financial institutions -- Kenya , Small business -- Kenya -- Data processing , Information technology -- Kenya -- Evaluation
- Full Text: false
- Date Issued: 2010
- Authors: Ndiege, Joshua Rumo Arongo
- Date: 2010
- Subjects: Small business -- Kenya , Financial institutions -- Kenya , Small business -- Kenya -- Data processing , Information technology -- Kenya -- Evaluation
- Language: English
- Type: Thesis , Masters , MCom (Information Systems)
- Identifier: vital:11132 , http://hdl.handle.net/10353/d1000973 , Small business -- Kenya , Financial institutions -- Kenya , Small business -- Kenya -- Data processing , Information technology -- Kenya -- Evaluation
- Full Text: false
- Date Issued: 2010
Stephen's garden
- Authors: Skead, C J (Cuthbert John)
- Date: 1997-08-11
- Subjects: Gardens -- South Africa -- Eastern Cape , Plants -- South Africa -- Eastern Cape
- Type: still image
- Identifier: vital:12574 , http://hdl.handle.net/10962/d1013981
- Description: Flowers in garden.
- Full Text: false
- Date Issued: 1997-08-11
- Authors: Skead, C J (Cuthbert John)
- Date: 1997-08-11
- Subjects: Gardens -- South Africa -- Eastern Cape , Plants -- South Africa -- Eastern Cape
- Type: still image
- Identifier: vital:12574 , http://hdl.handle.net/10962/d1013981
- Description: Flowers in garden.
- Full Text: false
- Date Issued: 1997-08-11
Stephen's garden
- Authors: Skead, C J (Cuthbert John)
- Date: 1997-08-11
- Subjects: Gardens -- South Africa -- Eastern Cape , Plants -- South Africa -- Eastern Cape
- Type: still image
- Identifier: vital:12578 , http://hdl.handle.net/10962/d1013985
- Description: Flowers in garden.
- Full Text: false
- Date Issued: 1997-08-11
- Authors: Skead, C J (Cuthbert John)
- Date: 1997-08-11
- Subjects: Gardens -- South Africa -- Eastern Cape , Plants -- South Africa -- Eastern Cape
- Type: still image
- Identifier: vital:12578 , http://hdl.handle.net/10962/d1013985
- Description: Flowers in garden.
- Full Text: false
- Date Issued: 1997-08-11
Iodine-Doped Cobalt Phthalocyanine Supported on Multiwalled Carbon Nanotubes for Electrocatalysis of Oxygen Reduction Reaction
- Nyoni, Stephen, Mashazi, Philani N, Nyokong, Tebello
- Authors: Nyoni, Stephen , Mashazi, Philani N , Nyokong, Tebello
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189434 , vital:44846 , xlink:href="https://doi.org/10.1002/elan.201400499"
- Description: 4-(4,6-Diaminopyrimidin-2-ylthio) phthalocyaninatocobalt(II) (CoPyPc) was iodine doped, and its electrocatalytic properties explored. Physical characterization techniques such as UV-vis, X-ray photoelectron, electron paramagnetic resonance and infra-red spectroscopy were used. Cyclic voltammetry, electrochemical impedance spectroscopy and rotating disk electrode were used for electrochemical characterization of electrodes modified with the prepared phthalocyanine and its nanocomposites. The electrocatalytic effect of a new iodine-doped cobalt phthalocyanine derivative supported on multiwalled carbon nanotubes was then investigated towards oxygen reduction reaction. The electrocatalytic activity of the iodine-doped cobalt phthalocyanine was found to be superior in terms of current over the undoped phthalocyanine nanocomposite.
- Full Text:
- Date Issued: 2015
- Authors: Nyoni, Stephen , Mashazi, Philani N , Nyokong, Tebello
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189434 , vital:44846 , xlink:href="https://doi.org/10.1002/elan.201400499"
- Description: 4-(4,6-Diaminopyrimidin-2-ylthio) phthalocyaninatocobalt(II) (CoPyPc) was iodine doped, and its electrocatalytic properties explored. Physical characterization techniques such as UV-vis, X-ray photoelectron, electron paramagnetic resonance and infra-red spectroscopy were used. Cyclic voltammetry, electrochemical impedance spectroscopy and rotating disk electrode were used for electrochemical characterization of electrodes modified with the prepared phthalocyanine and its nanocomposites. The electrocatalytic effect of a new iodine-doped cobalt phthalocyanine derivative supported on multiwalled carbon nanotubes was then investigated towards oxygen reduction reaction. The electrocatalytic activity of the iodine-doped cobalt phthalocyanine was found to be superior in terms of current over the undoped phthalocyanine nanocomposite.
- Full Text:
- Date Issued: 2015
Development of Graphene/CdSe Quantum Dots‐Co Phthalocyanine Nanocomposite for Oxygen Reduction Reaction
- Nyoni, Stephen, Nyokong, Tebello
- Authors: Nyoni, Stephen , Nyokong, Tebello
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189944 , vital:44950 , xlink:href="https://doi.org/10.1002/elan.201400372"
- Description: Nanocomposites containing CdSe quantum dots, tetra(4-(4,6-diaminopyrimidin-2-ylthio) phthalocyaninatocobalt(II)) (CoPyPc) and reduced graphene nanosheets (rGNS) were devoloped and used for the modification of a glassy carbon electrode. Characterization of the nanocomposites was done by transmission electron microscopy (TEM) and X-ray diffraction (XRD) analyses. Cyclic voltammetry (CV) was used for electrochemical characterization of the prepared nanocomposite for oxygen reduction reaction. The oxygen reduction activity for rGNS/CdSe-CoPyPc nanocomposite was found to be superior over the individual nanomaterials in this study. The activity of the nanocomposite towards oxygen reduction was also tested for tolerance to methanol crossover effect using chronoamperometry (CA) and electrochemical impedance spectroscopy (EIS) studies.
- Full Text:
- Date Issued: 2014
- Authors: Nyoni, Stephen , Nyokong, Tebello
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189944 , vital:44950 , xlink:href="https://doi.org/10.1002/elan.201400372"
- Description: Nanocomposites containing CdSe quantum dots, tetra(4-(4,6-diaminopyrimidin-2-ylthio) phthalocyaninatocobalt(II)) (CoPyPc) and reduced graphene nanosheets (rGNS) were devoloped and used for the modification of a glassy carbon electrode. Characterization of the nanocomposites was done by transmission electron microscopy (TEM) and X-ray diffraction (XRD) analyses. Cyclic voltammetry (CV) was used for electrochemical characterization of the prepared nanocomposite for oxygen reduction reaction. The oxygen reduction activity for rGNS/CdSe-CoPyPc nanocomposite was found to be superior over the individual nanomaterials in this study. The activity of the nanocomposite towards oxygen reduction was also tested for tolerance to methanol crossover effect using chronoamperometry (CA) and electrochemical impedance spectroscopy (EIS) studies.
- Full Text:
- Date Issued: 2014
Electrocatalytic behahiour of cobalt tetraamino-phthalocyanine in the presence of a composite of reduced graphene nanosheets and of multi-walled carbon nanotubes
- Nyoni, Stephen, Nyokong, Tebello
- Authors: Nyoni, Stephen , Nyokong, Tebello
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189784 , vital:44931 , xlink:href="https://doi.org/10.1016/j.electacta.2014.05.093"
- Description: A composite of multi-walled carbon nanotubes (MWCNT) with reduced graphene nanosheets (rGNS-2) was developed in order to minimize the restacking of the latter. The composite was used to modify a glassy carbon electrode (GCE). GCE was further modified with cobalt tetraamino phthalocyanine (CoTAPc). The modified electrode is represented as rGNS-2-MWCNT-CoTAPc-GCE. X-ray photoelectron spectroscopy, transmission electron microscopy, scanning electrochemical microscopy and Raman spectroscopy were used to explore into surface functionalities, morphology and topography of the nanocomposite. The rGNS-2-MWCNT-CoTAPc-GCE had a low limit of detection of 3.32 × 10−8 M towards the detection of paraguat as a test analyte. A mechanism for paraquat detection using an rGNS-2-MWCNT-CoTAPc-GCE is also proposed in this work.
- Full Text:
- Date Issued: 2014
- Authors: Nyoni, Stephen , Nyokong, Tebello
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189784 , vital:44931 , xlink:href="https://doi.org/10.1016/j.electacta.2014.05.093"
- Description: A composite of multi-walled carbon nanotubes (MWCNT) with reduced graphene nanosheets (rGNS-2) was developed in order to minimize the restacking of the latter. The composite was used to modify a glassy carbon electrode (GCE). GCE was further modified with cobalt tetraamino phthalocyanine (CoTAPc). The modified electrode is represented as rGNS-2-MWCNT-CoTAPc-GCE. X-ray photoelectron spectroscopy, transmission electron microscopy, scanning electrochemical microscopy and Raman spectroscopy were used to explore into surface functionalities, morphology and topography of the nanocomposite. The rGNS-2-MWCNT-CoTAPc-GCE had a low limit of detection of 3.32 × 10−8 M towards the detection of paraguat as a test analyte. A mechanism for paraquat detection using an rGNS-2-MWCNT-CoTAPc-GCE is also proposed in this work.
- Full Text:
- Date Issued: 2014
Improved l-cysteine electrocatalysis through a sequential drop dry technique using multi-walled carbon nanotubes and cobalt tetraaminophthalocyanine conjugates
- Nyoni, Stephen, Mugadza, Tawanda, Nyokong, Tebello
- Authors: Nyoni, Stephen , Mugadza, Tawanda , Nyokong, Tebello
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/193813 , vital:45398 , xlink:href="https://doi.org/10.1016/j.electacta.2013.10.023"
- Description: Voltammetry, chronoamperometry, scanning electrochemical microscopy and electrochemical impedance spectroscopy methods are used for characterization of a glassy carbon electrode modified with multi-walled carbon nanotubes (MWCNTs)–cobalt tetraaminophthalocyanine (CoTAPc) mixture or sequential drop dry modification technique whereby the MWCNTs are first placed on to the electrode followed by CoTAPc. The sequential drop dry CoTAPc–MWCNTs modified surface gave better catalytic responses with a catalytic rate constant of 2.2 × 105 M−1 s−1, apparent electron transfer rate constant of 0.073 cm s−1, and a limit of detection of 2.8 × 10−7 M. Scanning electrochemical microscopy (SECM) surface characterization (topography and reactivity) further gave proof the better catalytic perfomance of the sequential drop dry CoTAPc–MWCNTs modified surface.
- Full Text:
- Date Issued: 2014
- Authors: Nyoni, Stephen , Mugadza, Tawanda , Nyokong, Tebello
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/193813 , vital:45398 , xlink:href="https://doi.org/10.1016/j.electacta.2013.10.023"
- Description: Voltammetry, chronoamperometry, scanning electrochemical microscopy and electrochemical impedance spectroscopy methods are used for characterization of a glassy carbon electrode modified with multi-walled carbon nanotubes (MWCNTs)–cobalt tetraaminophthalocyanine (CoTAPc) mixture or sequential drop dry modification technique whereby the MWCNTs are first placed on to the electrode followed by CoTAPc. The sequential drop dry CoTAPc–MWCNTs modified surface gave better catalytic responses with a catalytic rate constant of 2.2 × 105 M−1 s−1, apparent electron transfer rate constant of 0.073 cm s−1, and a limit of detection of 2.8 × 10−7 M. Scanning electrochemical microscopy (SECM) surface characterization (topography and reactivity) further gave proof the better catalytic perfomance of the sequential drop dry CoTAPc–MWCNTs modified surface.
- Full Text:
- Date Issued: 2014
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
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189285 , vital:44834 , xlink:href="https://doi.org/10.1016/j.poly.2015.05.038"
- 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.
- Full Text:
- Date Issued: 2015
- Authors: Nyoni, Stephen , Nyokong, Tebello
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189285 , vital:44834 , xlink:href="https://doi.org/10.1016/j.poly.2015.05.038"
- 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.
- Full Text:
- Date Issued: 2015
Systematics of the Afrotropical Chalcididae (Hymenoptera: Chalcidoidea)
- Authors: Faure, Sariana
- Date: 2021-10-29
- Subjects: Uncatalogued
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/192808 , vital:45266
- Description: Thesis (PhD) -- Faculty of Science, Zoology and Entomology, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Faure, Sariana
- Date: 2021-10-29
- Subjects: Uncatalogued
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/192808 , vital:45266
- Description: Thesis (PhD) -- Faculty of Science, Zoology and Entomology, 2021
- Full Text:
- Date Issued: 2021-10-29