A touch of Africa : liberal bildung through an encounter with African immigrants in Andrew Brown's Refuge
- Authors: Fasselt, Rebecca
- Date: 2015-06-22
- Subjects: Liberalism in literature , Emigration and immigration - South Africa , Brown, Andrew. Refuge
- Type: Article
- Identifier: uj:5547 , ISSN 1812-5441 , http://hdl.handle.net/10210/14131
- Description: his article engages with the emergence of a “reconstructed liberalism” (Blair 2012) in South African fiction published after 2000 through a reading of Andrew Brown’s 2009 novel, Refuge. The novel, I argue, forms part of a body of fiction that views post-apartheid immigration from elsewhere on the African continent to South Africa through a predominantly liberal perspective. Reading Brown’s novel through the framework of the liberal Bildungsroman , I show that it is, however, largely the white characters who undergo a positive development through the encounter with Nigerian immigrants and refugees, while no such solution is offered for the migrant characters. Evoking “liberalism’s fetishization of victimhood” (Attwell 1993: 80), the novel partly constitutes African migrants as self-validating others. Yet, I also draw attention to the textual strategies employed that undercut any interpretation based on an uncritical adoption of a liberal stance in its engagement with migration...
- Full Text:
- Authors: Fasselt, Rebecca
- Date: 2015-06-22
- Subjects: Liberalism in literature , Emigration and immigration - South Africa , Brown, Andrew. Refuge
- Type: Article
- Identifier: uj:5547 , ISSN 1812-5441 , http://hdl.handle.net/10210/14131
- Description: his article engages with the emergence of a “reconstructed liberalism” (Blair 2012) in South African fiction published after 2000 through a reading of Andrew Brown’s 2009 novel, Refuge. The novel, I argue, forms part of a body of fiction that views post-apartheid immigration from elsewhere on the African continent to South Africa through a predominantly liberal perspective. Reading Brown’s novel through the framework of the liberal Bildungsroman , I show that it is, however, largely the white characters who undergo a positive development through the encounter with Nigerian immigrants and refugees, while no such solution is offered for the migrant characters. Evoking “liberalism’s fetishization of victimhood” (Attwell 1993: 80), the novel partly constitutes African migrants as self-validating others. Yet, I also draw attention to the textual strategies employed that undercut any interpretation based on an uncritical adoption of a liberal stance in its engagement with migration...
- Full Text:
An interactive, multivariate projection model for the alignment of teacher demand and supply for schools in the Gauteng Province of South Africa : a disaggregated approach.
- Marchant, Gavin, Lautenbach, Geoffrey
- Authors: Marchant, Gavin , Lautenbach, Geoffrey
- Date: 2011
- Subjects: Teacher supply , Teacher demand , Multivariate projection model
- Type: Article
- Identifier: uj:5760 , ISSN 1947-9417 , http://hdl.handle.net/10210/7766
- Description: This paper reports on the conceptualisation of a multivariate interactive computerised teacher demand and supply decision support model of projection for the Further Education and Training band (FET) of public schools for the Gauteng Province of South Africa. This model was conceptualised with the view to enabling policy makers to make projections that estimate aggregate or disaggregate teacher supply and demand. A reductionist methodological approach was used in this inquiry with the intention of reducing the ideas surrounding teacher supply and demand into a discrete set of variables reflected in a multivariate model. It also reflects a deterministic philosophy of cause and effect, as variables are manipulated within the model. Knowledge is developed in this inquiry through the development of multiple numeric measures of the objective reality of teacher supply and demand. The main contribution of this inquiry is the computerised disaggregated teacher supply and demand projection model. This model not only contributes to the knowledge base of educational planning and forecasting, but provides a clearer picture of the complex variables involved in teacher supply and demand as well.
- Full Text:
- Authors: Marchant, Gavin , Lautenbach, Geoffrey
- Date: 2011
- Subjects: Teacher supply , Teacher demand , Multivariate projection model
- Type: Article
- Identifier: uj:5760 , ISSN 1947-9417 , http://hdl.handle.net/10210/7766
- Description: This paper reports on the conceptualisation of a multivariate interactive computerised teacher demand and supply decision support model of projection for the Further Education and Training band (FET) of public schools for the Gauteng Province of South Africa. This model was conceptualised with the view to enabling policy makers to make projections that estimate aggregate or disaggregate teacher supply and demand. A reductionist methodological approach was used in this inquiry with the intention of reducing the ideas surrounding teacher supply and demand into a discrete set of variables reflected in a multivariate model. It also reflects a deterministic philosophy of cause and effect, as variables are manipulated within the model. Knowledge is developed in this inquiry through the development of multiple numeric measures of the objective reality of teacher supply and demand. The main contribution of this inquiry is the computerised disaggregated teacher supply and demand projection model. This model not only contributes to the knowledge base of educational planning and forecasting, but provides a clearer picture of the complex variables involved in teacher supply and demand as well.
- Full Text:
Bifurcation and hysteresis of flow pattern transition in a shallow molten silicon pool with Cz configuration
- Peng, Lan, Li, You-Rong, Liu, Ying-Jie, Imaishi, Nobuyuki, Jen, Tien-Chien, Chen, Qing-hua
- Authors: Peng, Lan , Li, You-Rong , Liu, Ying-Jie , Imaishi, Nobuyuki , Jen, Tien-Chien , Chen, Qing-hua
- Date: 2007
- Subjects: Bifurcation , Hysteresis , Flow pattern transition
- Type: Article
- Identifier: uj:5272 , ISSN 1040-7782 , http://hdl.handle.net/10210/14941
- Description: Please refer to full text to view abstract
- Full Text:
- Authors: Peng, Lan , Li, You-Rong , Liu, Ying-Jie , Imaishi, Nobuyuki , Jen, Tien-Chien , Chen, Qing-hua
- Date: 2007
- Subjects: Bifurcation , Hysteresis , Flow pattern transition
- Type: Article
- Identifier: uj:5272 , ISSN 1040-7782 , http://hdl.handle.net/10210/14941
- Description: Please refer to full text to view abstract
- Full Text:
Chaotic particle swarm optimization with neural network structure and its application
- Sun. A., Hopfield neural network.
- Authors: Sun. A. , Hopfield neural network.
- Date: 2011
- Subjects: Particle swarm optimization. , Bifurcation. , Convergence.
- Language: English
- Type: Article.
- Identifier: http://hdl.handle.net/10210/17007 , uj:15833 , ISSN: 0305-215X , Citation: Sun, Y. 2011. Chaotic particle swarm optimization with neural network structure and its application. Engineering Optimization, 43(1): 19-37
- Description: Abstract: A new particle swarm optimization (PSO) algorithm having a chaotic Hopfield Neural Network (HNN) structure is proposed. Particles exhibit chaotic behaviour before converging to a stable fixed point which is determined by the best points found by the individual particles and the swarm. During the evolutionary process, the chaotic search expands the search space of individual particles. Using a chaotic system to determine particle weights helps the PSO to escape from the local extreme and find the global optimum. The algorithm is applied to some benchmark problems and a pressure vessel problem with nonlinear constraints. The results show that the proposed algorithm consistently outperforms rival algorithms by enhancing search efficiency and improving search quality
- Full Text:
- Authors: Sun. A. , Hopfield neural network.
- Date: 2011
- Subjects: Particle swarm optimization. , Bifurcation. , Convergence.
- Language: English
- Type: Article.
- Identifier: http://hdl.handle.net/10210/17007 , uj:15833 , ISSN: 0305-215X , Citation: Sun, Y. 2011. Chaotic particle swarm optimization with neural network structure and its application. Engineering Optimization, 43(1): 19-37
- Description: Abstract: A new particle swarm optimization (PSO) algorithm having a chaotic Hopfield Neural Network (HNN) structure is proposed. Particles exhibit chaotic behaviour before converging to a stable fixed point which is determined by the best points found by the individual particles and the swarm. During the evolutionary process, the chaotic search expands the search space of individual particles. Using a chaotic system to determine particle weights helps the PSO to escape from the local extreme and find the global optimum. The algorithm is applied to some benchmark problems and a pressure vessel problem with nonlinear constraints. The results show that the proposed algorithm consistently outperforms rival algorithms by enhancing search efficiency and improving search quality
- Full Text:
Characterization of rice hull ash and its performance in turbidity removal from water
- Adams, F. V., Ikotun, B. D., Patrick, D. O., Mulaba-Bafubiandi, A. F.
- Authors: Adams, F. V. , Ikotun, B. D. , Patrick, D. O. , Mulaba-Bafubiandi, A. F.
- Date: 2014
- Subjects: Rice hull ash , Turbidity removal
- Type: Article
- Identifier: uj:4790 , http://hdl.handle.net/10210/12041
- Description: This study characterizes the locally obtained samples of rice hull ash and investigates its performance on turbidity removal from water. Four samples of this material were studied, namely, unwashed parboiled rice hull ash (UPRHA), washed parboiled rice hull ash (WPRHA), unwashed unparboiled rice hull ash (UUPRHA), and washed unparboiled rice hull ash (WUPRHA). Scanning electron microscopy (SEM), x-ray diffractometer (XRD), and Fourier infrared spectroscopy (FTIR) were carried out to characterize these samples. A filtration process was carried out to investigate the effectiveness of the rice hull ash medium in removing water turbidity. The XRD results showed the silica, which is present in the ashes, to be cristobalite, quartz, and tridymite. The silica contents of the UUPRHA and WUPRHA were observed to be 77.10% and 98.24%, respectively, while those of UPRHA and WPRHA were 79.07% and 94.97%, respectively. The SEM images showed agglomeration of ash particles after the ashes were washed. The washed RHA samples showed improved pH, a good percentage of turbidity removal (<5 NTU) from water sample. Washing RHA with distilled water increased the efficiency of RHA in turbidity removal from water and regulated water pH to an acceptable range.
- Full Text: false
- Authors: Adams, F. V. , Ikotun, B. D. , Patrick, D. O. , Mulaba-Bafubiandi, A. F.
- Date: 2014
- Subjects: Rice hull ash , Turbidity removal
- Type: Article
- Identifier: uj:4790 , http://hdl.handle.net/10210/12041
- Description: This study characterizes the locally obtained samples of rice hull ash and investigates its performance on turbidity removal from water. Four samples of this material were studied, namely, unwashed parboiled rice hull ash (UPRHA), washed parboiled rice hull ash (WPRHA), unwashed unparboiled rice hull ash (UUPRHA), and washed unparboiled rice hull ash (WUPRHA). Scanning electron microscopy (SEM), x-ray diffractometer (XRD), and Fourier infrared spectroscopy (FTIR) were carried out to characterize these samples. A filtration process was carried out to investigate the effectiveness of the rice hull ash medium in removing water turbidity. The XRD results showed the silica, which is present in the ashes, to be cristobalite, quartz, and tridymite. The silica contents of the UUPRHA and WUPRHA were observed to be 77.10% and 98.24%, respectively, while those of UPRHA and WPRHA were 79.07% and 94.97%, respectively. The SEM images showed agglomeration of ash particles after the ashes were washed. The washed RHA samples showed improved pH, a good percentage of turbidity removal (<5 NTU) from water sample. Washing RHA with distilled water increased the efficiency of RHA in turbidity removal from water and regulated water pH to an acceptable range.
- Full Text: false
Close-up Sophiatown : transnational perspectives on past, present and future of an iconic suburb
- Authors: Fink, Katharina
- Date: 2015-02-10
- Subjects: Sophiatown (South Africa) - History
- Type: Article
- Identifier: uj:5586 , ISSN 14692872 , http://hdl.handle.net/10210/14255
- Description: In this article I suggest a different view on Sophiatown’s existence, both in terms of it standing as mythical icon and as a suburb. Instead of continuing the look ‘from afar’ (Hannerz 1994), which positions Sophiatown within the category of desirable ‘global icons’, I turn my gaze deeper into Sophiatown, both as a suburb and an icon. I use the lens of transnationalism to zoom into three scenes in Sophiatown in order to examine what has been ignored and overlooked in previous nar-ratives. Where the global icon stays and focuses on the surface, the transnational perspective focuses on the everyday lives within the icon. Through a series of vignettes, looking at women in Sophiatown’s history, at coffee making with a Greek immigrant, and tales of home with Senegalese businessmen, through a consideration of Bloke Modisane’s post-Sophiatown career, I examine how the time established by focusing on these transnational lives is a time of presence which spans mul-tiple locations. I conclude the article with a final point about the ‘unrepresentability’ of a diverse history in the current ways of narrating history in Sophiatown; and the necessity of extending spaces of representation for other, alternative perspectives.
- Full Text:
- Authors: Fink, Katharina
- Date: 2015-02-10
- Subjects: Sophiatown (South Africa) - History
- Type: Article
- Identifier: uj:5586 , ISSN 14692872 , http://hdl.handle.net/10210/14255
- Description: In this article I suggest a different view on Sophiatown’s existence, both in terms of it standing as mythical icon and as a suburb. Instead of continuing the look ‘from afar’ (Hannerz 1994), which positions Sophiatown within the category of desirable ‘global icons’, I turn my gaze deeper into Sophiatown, both as a suburb and an icon. I use the lens of transnationalism to zoom into three scenes in Sophiatown in order to examine what has been ignored and overlooked in previous nar-ratives. Where the global icon stays and focuses on the surface, the transnational perspective focuses on the everyday lives within the icon. Through a series of vignettes, looking at women in Sophiatown’s history, at coffee making with a Greek immigrant, and tales of home with Senegalese businessmen, through a consideration of Bloke Modisane’s post-Sophiatown career, I examine how the time established by focusing on these transnational lives is a time of presence which spans mul-tiple locations. I conclude the article with a final point about the ‘unrepresentability’ of a diverse history in the current ways of narrating history in Sophiatown; and the necessity of extending spaces of representation for other, alternative perspectives.
- Full Text:
Controlled by Communists? : reassessing the years of ANC exile
- Authors: Landau, Paul, S.
- Date: 2015-07-06
- Subjects: Communism , African National Congress , South Africa - Politics and government
- Type: Article
- Identifier: uj:5567 , ISSN 1726-1686 , http://hdl.handle.net/10210/14186
- Description: Please refer to full text to view abstract
- Full Text:
- Authors: Landau, Paul, S.
- Date: 2015-07-06
- Subjects: Communism , African National Congress , South Africa - Politics and government
- Type: Article
- Identifier: uj:5567 , ISSN 1726-1686 , http://hdl.handle.net/10210/14186
- Description: Please refer to full text to view abstract
- Full Text:
Destructive creation : capital accumulation and the structural violence of tourism
- Büscher, Bram, Fletcher, Robert
- Authors: Büscher, Bram , Fletcher, Robert
- Date: 2016
- Subjects: Tourism , Capital , Value
- Language: English
- Type: Articles
- Identifier: http://hdl.handle.net/10210/241853 , uj:24932 , Citation: Bram Büscher & Robert Fletcher (2017) Destructive creation: capital accumulation and the structural violence of tourism, Journal of Sustainable Tourism, 25:5, 651-667, DOI: 10.1080/09669582.2016.1159214 , ISSN: 0966-9582
- Description: Abstract: Tourism is not merely a capitalist practice but a central practice through which capitalism sustains itself. Precisely how tourism “products” become capital and the types of violence this process entails, however, has not yet been systematically theorized or investigated. Building on Noel Castree’s six principles of commodification, we explore how tourism becomes capital, understood as “value in motion”, and how this process not only provokes various forms of material violence but can become a form of (structural) violence in its own right. Based on research in tourism settings in Southern Africa and Latin America and general trends in international tourism, we argue that three integrated forms of structural violence to both humans and non-human natures are especially prominent, namely the systematic production of inequalities, waste and “spaces of exception”. As a global industry crucially dependent on integrated material and discursive forms of value creation, we also show that these forms of structural violence are often rendered invisible through branding. We conclude that tourism uniquely combines these three forms of structural violence to enable a move from Schumpeter’s famous creative destruction to “destructive creation” as a key form of violence under capitalism.
- Full Text:
- Authors: Büscher, Bram , Fletcher, Robert
- Date: 2016
- Subjects: Tourism , Capital , Value
- Language: English
- Type: Articles
- Identifier: http://hdl.handle.net/10210/241853 , uj:24932 , Citation: Bram Büscher & Robert Fletcher (2017) Destructive creation: capital accumulation and the structural violence of tourism, Journal of Sustainable Tourism, 25:5, 651-667, DOI: 10.1080/09669582.2016.1159214 , ISSN: 0966-9582
- Description: Abstract: Tourism is not merely a capitalist practice but a central practice through which capitalism sustains itself. Precisely how tourism “products” become capital and the types of violence this process entails, however, has not yet been systematically theorized or investigated. Building on Noel Castree’s six principles of commodification, we explore how tourism becomes capital, understood as “value in motion”, and how this process not only provokes various forms of material violence but can become a form of (structural) violence in its own right. Based on research in tourism settings in Southern Africa and Latin America and general trends in international tourism, we argue that three integrated forms of structural violence to both humans and non-human natures are especially prominent, namely the systematic production of inequalities, waste and “spaces of exception”. As a global industry crucially dependent on integrated material and discursive forms of value creation, we also show that these forms of structural violence are often rendered invisible through branding. We conclude that tourism uniquely combines these three forms of structural violence to enable a move from Schumpeter’s famous creative destruction to “destructive creation” as a key form of violence under capitalism.
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Effective borehole thermal resistance of a single u-tube ground heat exchanger
- Liao, Quan, Zhou, Chao, Cui, Wenzhi, Jen, Tien-Chien
- Authors: Liao, Quan , Zhou, Chao , Cui, Wenzhi , Jen, Tien-Chien
- Date: 2012
- Subjects: Ground-source heat pumps
- Type: Article
- Identifier: uj:5271 , ISSN 1040-7782 , http://hdl.handle.net/10210/14940
- Description: A ground-source heat pump (GSHP) uses the earth as a heat source or heat sink to extract or reject the thermal energy. Since the annual temperature fluctuation of soil under the ground is relatively small, the GSHP system has been recognized as one of the most energy-efficient systems for space heating and cooling in residential and commercial buildings. In a GSHP system, one of the most important components is the ground-coupled heat exchanger, through which thermal energy is exchanged between heat carrier fluid (i.e., water or water-antifreeze fluid) and soil. Since the ground heat exchanger is responsible for a major portion of the initial cost of the GSHP system, and the efficiency of this system depends on the performance of a ground heat exchanger, careful design of the ground heat exchanger is crucial for successful application of the GSHP system [1].
- Full Text:
- Authors: Liao, Quan , Zhou, Chao , Cui, Wenzhi , Jen, Tien-Chien
- Date: 2012
- Subjects: Ground-source heat pumps
- Type: Article
- Identifier: uj:5271 , ISSN 1040-7782 , http://hdl.handle.net/10210/14940
- Description: A ground-source heat pump (GSHP) uses the earth as a heat source or heat sink to extract or reject the thermal energy. Since the annual temperature fluctuation of soil under the ground is relatively small, the GSHP system has been recognized as one of the most energy-efficient systems for space heating and cooling in residential and commercial buildings. In a GSHP system, one of the most important components is the ground-coupled heat exchanger, through which thermal energy is exchanged between heat carrier fluid (i.e., water or water-antifreeze fluid) and soil. Since the ground heat exchanger is responsible for a major portion of the initial cost of the GSHP system, and the efficiency of this system depends on the performance of a ground heat exchanger, careful design of the ground heat exchanger is crucial for successful application of the GSHP system [1].
- Full Text:
En-visioning the dance : the audience as mirror
- Authors: Botha, Catherine F.
- Date: 2015-07-21
- Subjects: Mirror metaphor , Art audience , Dance , Dewey, John. Arts as experience
- Type: Article
- Identifier: uj:5549 , ISSN 2163-7660 , ISSN 1013-7548 , http://hdl.handle.net/10210/14134
- Description: The current article is focused upon an exploration of the question of the nature of the art audience, with a specific emphasis on dance considered as a performing art. Five possible kinds of perceiver involved in the reception of dance as an art are discussed in order to demonstrate that the much criticized metaphor of the mirror can indeed function as a fruitful means to develop an understanding of how dance as an art is perceived, specifically if a more nuanced understanding of the mirror metaphor is applied. In its attempt to rehabilitate this metaphor, the paper draws upon and develops selected aspects of the philosophy of art proposed by John Dewey in his often overlooked Art as Experience (1934).
- Full Text:
- Authors: Botha, Catherine F.
- Date: 2015-07-21
- Subjects: Mirror metaphor , Art audience , Dance , Dewey, John. Arts as experience
- Type: Article
- Identifier: uj:5549 , ISSN 2163-7660 , ISSN 1013-7548 , http://hdl.handle.net/10210/14134
- Description: The current article is focused upon an exploration of the question of the nature of the art audience, with a specific emphasis on dance considered as a performing art. Five possible kinds of perceiver involved in the reception of dance as an art are discussed in order to demonstrate that the much criticized metaphor of the mirror can indeed function as a fruitful means to develop an understanding of how dance as an art is perceived, specifically if a more nuanced understanding of the mirror metaphor is applied. In its attempt to rehabilitate this metaphor, the paper draws upon and develops selected aspects of the philosophy of art proposed by John Dewey in his often overlooked Art as Experience (1934).
- Full Text:
Family biography, fertility and memory-making in an AIDS-affected South African site
- Authors: Naidoo, Kammila
- Date: 2014-11-21
- Subjects: Family biography , Life history , AIDS (Disease)
- Type: Article
- Identifier: uj:5605 , ISSN 1081602x , http://hdl.handle.net/10210/14336
- Description: Please refer to full text to view abstract
- Full Text: false
- Authors: Naidoo, Kammila
- Date: 2014-11-21
- Subjects: Family biography , Life history , AIDS (Disease)
- Type: Article
- Identifier: uj:5605 , ISSN 1081602x , http://hdl.handle.net/10210/14336
- Description: Please refer to full text to view abstract
- Full Text: false
Five funerals, no weddings, a couple of birthdays : Terry Ranger, his contemporaries, and the end of Zimbabwean nationalism – 24 October 2013–3 January 2015
- Authors: Moore, David
- Date: 2015-04-15
- Subjects: Nationalism - Zimbabwe , Zimbabwe - Politics and government , Ranger, T.O.
- Type: Article
- Identifier: uj:5600 , ISSN 17401720 , http://hdl.handle.net/10210/14330
- Description: Please refer to full text to view abstract
- Full Text:
- Authors: Moore, David
- Date: 2015-04-15
- Subjects: Nationalism - Zimbabwe , Zimbabwe - Politics and government , Ranger, T.O.
- Type: Article
- Identifier: uj:5600 , ISSN 17401720 , http://hdl.handle.net/10210/14330
- Description: Please refer to full text to view abstract
- Full Text:
Low temperature synthesis of multiwalled carbon nanotubes and incorporation into an organic solar cell
- Mugadza, Kudzai, Nyamori, Vincent O., Mola, Genene T., Simoyi, Reuben H., Ndungu, Patrick G.
- Authors: Mugadza, Kudzai , Nyamori, Vincent O. , Mola, Genene T. , Simoyi, Reuben H. , Ndungu, Patrick G.
- Date: 2017
- Subjects: Carbon nanotubes , Low temperature synthesis , Non-equilibrium plasma
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/251802 , uj:26233 , Citation: Mugadza, K. et al. 2017. Low temperature synthesis of multiwalled carbon nanotubes and incorporation into an organic solar cell. Journal of Experimental Nanoscience, 12:1, 363-383, DOI: 10.1080/17458080.2017.1357842 , ISSN: 1745-8080 (Print) , ISSN: 1745-8099 (Online)
- Description: Abstract: Metal nanoparticle (MNP) catalysts used for the synthesis of multiwalled carbon nanotubes (MWCNTs) consisted of single metals (Fe, Ni or Co) and bimetallic mixture (CoFe, NiFe or NiCo). MWCNTs were successfully synthesised at 200 _C in 10 min using liquefied petroleum gas as carbon source with non-equilibrium plasma enhanced chemical vapour deposition (PECVD) method. The nanostructures and the morphology of the MNPs and the MWCNTs film were characterised using relevant microscopic and spectroscopic methods. The synthesised MWCNTs were used as part of the electrode material in organic solar cell (OSC) set-up. Poly (3,4- ethylenedioxythiophene): polystyrene sulfonate (PEDOT: PSS) was used as an electron transporter and poly-3-hexyl thiophene (P3HT) as an electron donor. The performance of OSC devices was tested using standard electrical measurements and solar simulator operating at 100 mW/cm2. The measured power conversion efficiencies was found to be dependent on the metal catalyst used during synthesis. Among all the catalysts employed in this investigation, the best device performance was found from the synthesis of MWCNTs using Fe as a catalyst followed by Co and then Ni, respectively.
- Full Text:
- Authors: Mugadza, Kudzai , Nyamori, Vincent O. , Mola, Genene T. , Simoyi, Reuben H. , Ndungu, Patrick G.
- Date: 2017
- Subjects: Carbon nanotubes , Low temperature synthesis , Non-equilibrium plasma
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/251802 , uj:26233 , Citation: Mugadza, K. et al. 2017. Low temperature synthesis of multiwalled carbon nanotubes and incorporation into an organic solar cell. Journal of Experimental Nanoscience, 12:1, 363-383, DOI: 10.1080/17458080.2017.1357842 , ISSN: 1745-8080 (Print) , ISSN: 1745-8099 (Online)
- Description: Abstract: Metal nanoparticle (MNP) catalysts used for the synthesis of multiwalled carbon nanotubes (MWCNTs) consisted of single metals (Fe, Ni or Co) and bimetallic mixture (CoFe, NiFe or NiCo). MWCNTs were successfully synthesised at 200 _C in 10 min using liquefied petroleum gas as carbon source with non-equilibrium plasma enhanced chemical vapour deposition (PECVD) method. The nanostructures and the morphology of the MNPs and the MWCNTs film were characterised using relevant microscopic and spectroscopic methods. The synthesised MWCNTs were used as part of the electrode material in organic solar cell (OSC) set-up. Poly (3,4- ethylenedioxythiophene): polystyrene sulfonate (PEDOT: PSS) was used as an electron transporter and poly-3-hexyl thiophene (P3HT) as an electron donor. The performance of OSC devices was tested using standard electrical measurements and solar simulator operating at 100 mW/cm2. The measured power conversion efficiencies was found to be dependent on the metal catalyst used during synthesis. Among all the catalysts employed in this investigation, the best device performance was found from the synthesis of MWCNTs using Fe as a catalyst followed by Co and then Ni, respectively.
- Full Text:
May the real Ubuntu please stand up?
- Authors: Mboti, Nyasha
- Date: 2015
- Subjects: Ubuntu (Philosophy)
- Type: Article
- Identifier: uj:5560 , ISSN 23736992 , http://hdl.handle.net/10210/14179
- Description: Please refer to full text to view abstract
- Full Text:
- Authors: Mboti, Nyasha
- Date: 2015
- Subjects: Ubuntu (Philosophy)
- Type: Article
- Identifier: uj:5560 , ISSN 23736992 , http://hdl.handle.net/10210/14179
- Description: Please refer to full text to view abstract
- Full Text:
MIMO Channel Modeling: A Review
- Bhattacharjee, Ratnajit, Babu, B.S.
- Authors: Bhattacharjee, Ratnajit , Babu, B.S.
- Date: 2008
- Subjects: Multi-antenna channels. , Channel modeling , MIMO channels,
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/17997 , uj:15947 , ISSN: 0256-4602 , DOI: 10.4103/0256-4602.45423 , Paul, B.S. & Bhattacharjee, R. 2008. MIMO channel modeling : a review. IETE Technical Review, 25(6) pp. 315–319. DOI: 10.4103/0256-4602.45423.
- Description: Abstract: Channel modeling plays an important role in understanding the behavior and designing of communication systems for different environments. In this paper, we make a brief review of the different channel modeling techniques used to model a multiple-input-multiple-output (MIMO) wireless channel.
- Full Text:
- Authors: Bhattacharjee, Ratnajit , Babu, B.S.
- Date: 2008
- Subjects: Multi-antenna channels. , Channel modeling , MIMO channels,
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/17997 , uj:15947 , ISSN: 0256-4602 , DOI: 10.4103/0256-4602.45423 , Paul, B.S. & Bhattacharjee, R. 2008. MIMO channel modeling : a review. IETE Technical Review, 25(6) pp. 315–319. DOI: 10.4103/0256-4602.45423.
- Description: Abstract: Channel modeling plays an important role in understanding the behavior and designing of communication systems for different environments. In this paper, we make a brief review of the different channel modeling techniques used to model a multiple-input-multiple-output (MIMO) wireless channel.
- Full Text:
Numerical analysis in interrupted cutting tool temperatures
- Jen, Tien-Chien, Gutierrez, Gustavo, Eapen, Sunil
- Authors: Jen, Tien-Chien , Gutierrez, Gustavo , Eapen, Sunil
- Date: 2011
- Subjects: Numerical analysis , Cutting tools , Cutting temperatures
- Type: Article
- Identifier: uj:5243 , ISSN 1040-7782 , http://hdl.handle.net/10210/14843
- Description: In any cutting process, plastic deformation involved in chip formation and friction between the tool and the workpiece produces heat by the conversion of mechanical energy. A portion of this heat conducts into the tool and results in high temperatures near the cutting edge. As the temperature increases, the tool becomes softer and wears more rapidly, thus having a negative impact on tool life. In many cutting processes, tool life, or tool wear, is the major limitation to the process viability. Increased temperature also affects the dimensional accuracy of the products and machining efficiency. Because of these considerations, it is crucial to be able to predict accurately the tool temperature. Cutting temperatures have been studied widely for a number of years. Most research, however, has been restricted to steady state temperatures in relatively simple processes, such as orthogonal cutting or cylindrical turning, in which the cutting speed, feed rate, and the depth of cut are constant [1^3, 17, 21, 24]. In most industrial machining processes, however, these parameters vary with time so that a steady state temperature assumption may not be valid.
- Full Text:
- Authors: Jen, Tien-Chien , Gutierrez, Gustavo , Eapen, Sunil
- Date: 2011
- Subjects: Numerical analysis , Cutting tools , Cutting temperatures
- Type: Article
- Identifier: uj:5243 , ISSN 1040-7782 , http://hdl.handle.net/10210/14843
- Description: In any cutting process, plastic deformation involved in chip formation and friction between the tool and the workpiece produces heat by the conversion of mechanical energy. A portion of this heat conducts into the tool and results in high temperatures near the cutting edge. As the temperature increases, the tool becomes softer and wears more rapidly, thus having a negative impact on tool life. In many cutting processes, tool life, or tool wear, is the major limitation to the process viability. Increased temperature also affects the dimensional accuracy of the products and machining efficiency. Because of these considerations, it is crucial to be able to predict accurately the tool temperature. Cutting temperatures have been studied widely for a number of years. Most research, however, has been restricted to steady state temperatures in relatively simple processes, such as orthogonal cutting or cylindrical turning, in which the cutting speed, feed rate, and the depth of cut are constant [1^3, 17, 21, 24]. In most industrial machining processes, however, these parameters vary with time so that a steady state temperature assumption may not be valid.
- Full Text:
Numerical simulation of fluid flow and heat transfer in a curved square duct by using the Lattice Boltzmann method
- Authors: Liao, Quan , Jen, T.-C.
- Date: 2008
- Subjects: Fluid flow , Heat transfer
- Type: Article
- Identifier: uj:5274 , ISSN 1040-7782 , http://hdl.handle.net/10210/14943
- Description: The study of viscous flow in curved ducts is of fundamental interest in fluid mechanics due to the numerous applications such as flows through turbomachinery blade passages, aircraft intakes, diffusers, heat exchangers, and so on [1–6]. The major effect of curved ducts on the fluid flow involves the strong secondary flow due to the longitudinal curvature in the geometry [7–9]. The presence of longitudinal curvature generates centrifugal force (which is perpendicular to the main flow along the axis) and produces so-called secondary flow on the cross sections of ducts.
- Full Text:
- Authors: Liao, Quan , Jen, T.-C.
- Date: 2008
- Subjects: Fluid flow , Heat transfer
- Type: Article
- Identifier: uj:5274 , ISSN 1040-7782 , http://hdl.handle.net/10210/14943
- Description: The study of viscous flow in curved ducts is of fundamental interest in fluid mechanics due to the numerous applications such as flows through turbomachinery blade passages, aircraft intakes, diffusers, heat exchangers, and so on [1–6]. The major effect of curved ducts on the fluid flow involves the strong secondary flow due to the longitudinal curvature in the geometry [7–9]. The presence of longitudinal curvature generates centrifugal force (which is perpendicular to the main flow along the axis) and produces so-called secondary flow on the cross sections of ducts.
- Full Text:
Numerical simulation of solute redistribution during transient liquid phase bonding processing for Al-Cu alloy"
- Jiao, Y., Jen, Tien-Chien, Jiao, Yuning
- Authors: Jiao, Y. , Jen, Tien-Chien , Jiao, Yuning
- Date: 2011
- Subjects: Numerical simulation , Solute redistribution , Transient liquid phase , Aluminum alloys , Copper alloys
- Type: Article
- Identifier: uj:5246 , ISSN 1040-7782 , http://hdl.handle.net/10210/14852
- Description: A one-dimensional mathematical model is developed to predict the solute redistribution during the transient liquid phase (TLP) bonding process for Al-Cu alloy. The macroscopic solute diffusion in the liquid and the solid as well as for the solid transformation to the liquid because of the solute macrosegregation are considered in this study. The effects of holding temperatures and the interlayer thickness on the holding time, remelting layer thickness, and the mush zone thickness of the TLP bonding process are investigated. It is shown numerically that the holding time, the holding temperature, and the interlayer thickness influence the solute distribution strongly, which in turn influence the mush zone thickness significantly.
- Full Text:
- Authors: Jiao, Y. , Jen, Tien-Chien , Jiao, Yuning
- Date: 2011
- Subjects: Numerical simulation , Solute redistribution , Transient liquid phase , Aluminum alloys , Copper alloys
- Type: Article
- Identifier: uj:5246 , ISSN 1040-7782 , http://hdl.handle.net/10210/14852
- Description: A one-dimensional mathematical model is developed to predict the solute redistribution during the transient liquid phase (TLP) bonding process for Al-Cu alloy. The macroscopic solute diffusion in the liquid and the solid as well as for the solid transformation to the liquid because of the solute macrosegregation are considered in this study. The effects of holding temperatures and the interlayer thickness on the holding time, remelting layer thickness, and the mush zone thickness of the TLP bonding process are investigated. It is shown numerically that the holding time, the holding temperature, and the interlayer thickness influence the solute distribution strongly, which in turn influence the mush zone thickness significantly.
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Of Faustian pacts and mega-projects : the politics and economics of the port expansion in the South Basin of Durban, South Africa
- Authors: Desai, Ashwin
- Date: 2015-01-19
- Subjects: Harbors - Political aspects - South Africa - Durban , Harbors - Economic aspects - South Africa - Durban
- Type: Article
- Identifier: uj:5599 , ISSN 10455752 , http://hdl.handle.net/10210/14312
- Description: Please refer to full text to view abstract
- Full Text:
- Authors: Desai, Ashwin
- Date: 2015-01-19
- Subjects: Harbors - Political aspects - South Africa - Durban , Harbors - Economic aspects - South Africa - Durban
- Type: Article
- Identifier: uj:5599 , ISSN 10455752 , http://hdl.handle.net/10210/14312
- Description: Please refer to full text to view abstract
- Full Text:
Operating strategies and capacitor voltace balance strategies for a cascaded "3-5-9" hybrid inverter for grid interface application
- Wanjekeche, Tom, Nicolae, Dan-Valentin, Jimoh, Adisa A.
- Authors: Wanjekeche, Tom , Nicolae, Dan-Valentin , Jimoh, Adisa A.
- Date: 2014
- Subjects: Electric power supply , Power electronics
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/17500 , uj:15891 , Citation: Wanjekeche, T., Nicolae, D.V. & Jimoh, A.A. 2014. Operating strategies and capacitor voltace balance strategies for a cascaded "3-5-9" hybrid inverter for grid interface application. International journal of modelling and simulation, 34(1). DOI:10.2316/Journal.205.2014.1.205-5724-5724 , DOI:10.2316/Journal.205.2014.1.205-5724 , ISSN:0228-6203 (Print) , ISSN:1925-7082 (Online)
- Description: Abstract: The paper presents a novel phase shifted SPWM control scheme for cascading two cells to form a “3-5-9 hybrid inverter with improved harmonic suppression. Modeling of the hybrid inverter from first principle is introduced and a standard control law is derived for further analysis and development of the model. A new balance circuit for DC link voltage control is designed and tested. Combined with individual voltage control, a complete control scheme is developed. Detailed MATLAB simulation and experimental results are obtained for further validation of the adopted topology and the control scheme
- Full Text:
- Authors: Wanjekeche, Tom , Nicolae, Dan-Valentin , Jimoh, Adisa A.
- Date: 2014
- Subjects: Electric power supply , Power electronics
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/17500 , uj:15891 , Citation: Wanjekeche, T., Nicolae, D.V. & Jimoh, A.A. 2014. Operating strategies and capacitor voltace balance strategies for a cascaded "3-5-9" hybrid inverter for grid interface application. International journal of modelling and simulation, 34(1). DOI:10.2316/Journal.205.2014.1.205-5724-5724 , DOI:10.2316/Journal.205.2014.1.205-5724 , ISSN:0228-6203 (Print) , ISSN:1925-7082 (Online)
- Description: Abstract: The paper presents a novel phase shifted SPWM control scheme for cascading two cells to form a “3-5-9 hybrid inverter with improved harmonic suppression. Modeling of the hybrid inverter from first principle is introduced and a standard control law is derived for further analysis and development of the model. A new balance circuit for DC link voltage control is designed and tested. Combined with individual voltage control, a complete control scheme is developed. Detailed MATLAB simulation and experimental results are obtained for further validation of the adopted topology and the control scheme
- Full Text: