'Hayi, they don’t know Xhosa’: Comparative isiXhosa teaching challenges in the Eastern Cape and Gauteng
- Kaschula, Russell H, Kretzer, Michael M
- Authors: Kaschula, Russell H , Kretzer, Michael M
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/${Handle} , vital:42499 , https://doi.org/10.1080/02572117.2019.1672318
- Description: Language-in-education policy in South Africa is underpinned by the Constitution. The gap that this research addresses is the inconsistency of policy implementation and the actual teaching of isiXhosa in primary schools. It analyses the official and overt language policy and the (covert) language practices at schools. Semi-structured interviews were conducted with language teachers and principals. Data were also gathered from classroom observations and document analysis in the Eastern Cape and Gauteng. On the one hand, there are standard language policy documents that exist. These advocate for English as a language of learning and teaching and isiXhosa as a subject. On the other hand, the daily reality in classrooms partly reflects this policy implementation.
- Full Text:
- Date Issued: 2019
- Authors: Kaschula, Russell H , Kretzer, Michael M
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/${Handle} , vital:42499 , https://doi.org/10.1080/02572117.2019.1672318
- Description: Language-in-education policy in South Africa is underpinned by the Constitution. The gap that this research addresses is the inconsistency of policy implementation and the actual teaching of isiXhosa in primary schools. It analyses the official and overt language policy and the (covert) language practices at schools. Semi-structured interviews were conducted with language teachers and principals. Data were also gathered from classroom observations and document analysis in the Eastern Cape and Gauteng. On the one hand, there are standard language policy documents that exist. These advocate for English as a language of learning and teaching and isiXhosa as a subject. On the other hand, the daily reality in classrooms partly reflects this policy implementation.
- Full Text:
- Date Issued: 2019
(Unused) potentials of educators’ covert language policies at public schools in Limpopo, South Africa:
- Kretzer, Michael M, Kaschula, Russell H
- Authors: Kretzer, Michael M , Kaschula, Russell H
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/174679 , vital:42500 , DOI: 10.1039/D0PP00075B
- Description: Language policy is an influencing factor of the educational outcome for pupils in Africa. Colonial languages have been largely used and African Languages are neglected. Despite this, the South African Constitution (1996) declares eleven official languages. However, curricular developments favour Afrikaans and English. To analyse the implementation of the official language policy, we focus on Limpopo Province. Over 1000 questionnaires were answered by teachers. This approach aimed to analyse the language practices and language attitudes of teachers. Schools in Limpopo showed significant differences between the official language policy and the daily language practices. Some teachers implement the official language policy; others use one or more African languages in their oral communications during the lessons in the form of Code Switching.
- Full Text:
- Date Issued: 2020
- Authors: Kretzer, Michael M , Kaschula, Russell H
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/174679 , vital:42500 , DOI: 10.1039/D0PP00075B
- Description: Language policy is an influencing factor of the educational outcome for pupils in Africa. Colonial languages have been largely used and African Languages are neglected. Despite this, the South African Constitution (1996) declares eleven official languages. However, curricular developments favour Afrikaans and English. To analyse the implementation of the official language policy, we focus on Limpopo Province. Over 1000 questionnaires were answered by teachers. This approach aimed to analyse the language practices and language attitudes of teachers. Schools in Limpopo showed significant differences between the official language policy and the daily language practices. Some teachers implement the official language policy; others use one or more African languages in their oral communications during the lessons in the form of Code Switching.
- Full Text:
- Date Issued: 2020
A capillary zone electrophoresis (CZE) method for the determination of cyclizine hydrochloride in tablets and suppositories
- Mohammadi, I, Kanfer, Isadore, Walker, Roderick B
- Authors: Mohammadi, I , Kanfer, Isadore , Walker, Roderick B
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6406 , http://hdl.handle.net/10962/d1006479
- Description: Current compendial methods of assay for the analysis of cyclizine tablets involve the use of UV spectrophotometry. Since this is a non-selective technique its application to more complex dosage forms, such as suppositories, is unlikely to be appropriate. There is therefore a need for the development of a highly specific quantitative analytical method, such as high performance liquid chromatography (HPLC) or capillary electrophoresis (CE). The latter technique was chosen in view of some specific advantages over HPLC, such as the use of relatively non-toxic aqueous buffers, as opposed to organic solvents, which obviates the use of expensive HPLC grade solvents making CE more cost effective. Cyclizine was analyzed in 50 mM phosphate buffer (pH 2.3) and run at an applied voltage 25 kV. Detection sensitivity was enhanced by using a wavelength of 200 nm and samples were loaded hydrodynamically onto an uncoated fused-silica capillary (60 cm×50 mm i.d.). Chlorcyclizine was used as the internal standard and resolution of both compounds was achieved in less than 7 min. Stress testing was undertaken in order to investigate the appearance of breakdown products. The method has the requisite accuracy, selectivity, sensitivity and precision to assay cyclizine in tablets and suppositories. Degradation products resulting from the stress studies did not interfere with the detection of cyclizine and the assay is thus stability-indicating.
- Full Text:
- Date Issued: 2004
- Authors: Mohammadi, I , Kanfer, Isadore , Walker, Roderick B
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6406 , http://hdl.handle.net/10962/d1006479
- Description: Current compendial methods of assay for the analysis of cyclizine tablets involve the use of UV spectrophotometry. Since this is a non-selective technique its application to more complex dosage forms, such as suppositories, is unlikely to be appropriate. There is therefore a need for the development of a highly specific quantitative analytical method, such as high performance liquid chromatography (HPLC) or capillary electrophoresis (CE). The latter technique was chosen in view of some specific advantages over HPLC, such as the use of relatively non-toxic aqueous buffers, as opposed to organic solvents, which obviates the use of expensive HPLC grade solvents making CE more cost effective. Cyclizine was analyzed in 50 mM phosphate buffer (pH 2.3) and run at an applied voltage 25 kV. Detection sensitivity was enhanced by using a wavelength of 200 nm and samples were loaded hydrodynamically onto an uncoated fused-silica capillary (60 cm×50 mm i.d.). Chlorcyclizine was used as the internal standard and resolution of both compounds was achieved in less than 7 min. Stress testing was undertaken in order to investigate the appearance of breakdown products. The method has the requisite accuracy, selectivity, sensitivity and precision to assay cyclizine in tablets and suppositories. Degradation products resulting from the stress studies did not interfere with the detection of cyclizine and the assay is thus stability-indicating.
- Full Text:
- Date Issued: 2004
A Case Study of an Institutional Audit: A Social Realist Account
- Quinn, Lynn, Boughey, Chrissie M
- Authors: Quinn, Lynn , Boughey, Chrissie M
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/483215 , vital:78733 , https://doi.org/10.1080/13538320903343172
- Description: Since 1994, the South African higher education system, fragmented and divided along racial lines during the years of apartheid, has been subject to a wide range of initiatives directed at bringing about the ‘transformation’ necessary for a more equitable dispensation and, ultimately, a new social order. One of the ‘levers’ being used in transformation processes is quality assurance. The paper uses a case study of an institutional audit at one historically white, élite South African university to provide a social realist account of an audit process and to analyse the likelihood of the audit contributing to institutional transformation. A conclusion is that the South African audit methodology per se is unlikely to bring about the change necessary because of its tendency to focus on the mechanistic implementation of recommendations.
- Full Text:
- Date Issued: 2009
- Authors: Quinn, Lynn , Boughey, Chrissie M
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/483215 , vital:78733 , https://doi.org/10.1080/13538320903343172
- Description: Since 1994, the South African higher education system, fragmented and divided along racial lines during the years of apartheid, has been subject to a wide range of initiatives directed at bringing about the ‘transformation’ necessary for a more equitable dispensation and, ultimately, a new social order. One of the ‘levers’ being used in transformation processes is quality assurance. The paper uses a case study of an institutional audit at one historically white, élite South African university to provide a social realist account of an audit process and to analyse the likelihood of the audit contributing to institutional transformation. A conclusion is that the South African audit methodology per se is unlikely to bring about the change necessary because of its tendency to focus on the mechanistic implementation of recommendations.
- Full Text:
- Date Issued: 2009
A computer network attack taxonomy and ontology
- Van Heerden, Renier P, Irwin, Barry V W, Burke, Ivan D, Leenen, Louise
- Authors: Van Heerden, Renier P , Irwin, Barry V W , Burke, Ivan D , Leenen, Louise
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430064 , vital:72663 , DOI: 10.4018/ijcwt.2012070102
- Description: Computer network attacks differ in the motivation of the entity behind the attack, the execution and the end result. The diversity of attacks has the consequence that no standard classification ex-ists. The benefit of automated classification of attacks, means that an attack could be mitigated accordingly. The authors extend a previous, initial taxonomy of computer network attacks which forms the basis of a proposed network attack ontology in this pa-per. The objective of this ontology is to automate the classifica-tion of a network attack during its early stages. Most published taxonomies present an attack from either the attacker's or defend-er's point of view. The authors' taxonomy presents both these points of view. The framework for an ontology was developed using a core class, the "Attack Scenario", which can be used to characterize and classify computer network attacks.
- Full Text:
- Date Issued: 2012
- Authors: Van Heerden, Renier P , Irwin, Barry V W , Burke, Ivan D , Leenen, Louise
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430064 , vital:72663 , DOI: 10.4018/ijcwt.2012070102
- Description: Computer network attacks differ in the motivation of the entity behind the attack, the execution and the end result. The diversity of attacks has the consequence that no standard classification ex-ists. The benefit of automated classification of attacks, means that an attack could be mitigated accordingly. The authors extend a previous, initial taxonomy of computer network attacks which forms the basis of a proposed network attack ontology in this pa-per. The objective of this ontology is to automate the classifica-tion of a network attack during its early stages. Most published taxonomies present an attack from either the attacker's or defend-er's point of view. The authors' taxonomy presents both these points of view. The framework for an ontology was developed using a core class, the "Attack Scenario", which can be used to characterize and classify computer network attacks.
- Full Text:
- Date Issued: 2012
A Critical exploration of YouTube texts by and about people with disabilities in South Africa
- Authors: Dalvit, Lorenzo
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/468129 , vital:77021 , https://rosa.uniroma1.it/rosa03/mediascapes/article/view/18303
- Description: The work of intellectuals such as Marx and Gramsci has been exten-sively employed in the study of social inequalities across contexts and in relation to different dimensions. As one of the most unequal societies in the world, South Africa provides a number of past and recent exam-ples of discrimination, oppression and violence on the basis of race, gender, socio-economic and migrant status, political affiliation etc. De-spite their continued marginalisation during and after apartheid and de-spite accounting for a substantial portion (7.5%) of the population, peo-ple with disabilities appear relatively neglected in scholarly and media debates. The booming Internet and mobile penetration, which promised to give a voice to the voiceless, increasingly seems to reproduce and at times exacerbate such marginalisation. By drawing on Gramsci’s no-tions of hegemony and public intellectuals, in this paper, I explore dis-cursive constructions by and about South Africans with disabilities on YouTube. Videos and comments are purposively selected from three active channels based on their relevance and are quantitatively as well as qualitatively analysed. The first objective of the study is to under-stand disability in relation to other dimensions of diversity, eg race or gender.
- Full Text:
- Date Issued: 2023
- Authors: Dalvit, Lorenzo
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/468129 , vital:77021 , https://rosa.uniroma1.it/rosa03/mediascapes/article/view/18303
- Description: The work of intellectuals such as Marx and Gramsci has been exten-sively employed in the study of social inequalities across contexts and in relation to different dimensions. As one of the most unequal societies in the world, South Africa provides a number of past and recent exam-ples of discrimination, oppression and violence on the basis of race, gender, socio-economic and migrant status, political affiliation etc. De-spite their continued marginalisation during and after apartheid and de-spite accounting for a substantial portion (7.5%) of the population, peo-ple with disabilities appear relatively neglected in scholarly and media debates. The booming Internet and mobile penetration, which promised to give a voice to the voiceless, increasingly seems to reproduce and at times exacerbate such marginalisation. By drawing on Gramsci’s no-tions of hegemony and public intellectuals, in this paper, I explore dis-cursive constructions by and about South Africans with disabilities on YouTube. Videos and comments are purposively selected from three active channels based on their relevance and are quantitatively as well as qualitatively analysed. The first objective of the study is to under-stand disability in relation to other dimensions of diversity, eg race or gender.
- Full Text:
- Date Issued: 2023
A feminist perspective on autonomism and commoning, with reference to Zimbabwe
- Alexander, Tarryn, Helliker, Kirk D
- Authors: Alexander, Tarryn , Helliker, Kirk D
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/71374 , vital:29838 , https://doi.org/10.1080/02589001.2016.1235353
- Description: This article engages with the autonomist Marxism of John Holloway from a feminist standpoint. The positions developed by this feminist critique are used to shed new light on the land occupations in contemporary Zimbabwe. Though sympathetic to his work, we argue that Holloway does not sufficiently address gender identity with specific reference to social reproduction and women. The notions of the commons and the process of commoning are consistent with Holloway’s autonomist framework and its complementarities to Silvia Federici’s Marxist feminist lens on the commons is highlighted. Against a tendency within autonomist and commoning theories, we argue for a pronounced identitarian politics as grounded in localised struggles undertaken by women as women. We privilege the significance of women asserting and revaluing their identities as part of a possible project of transformation. For us, struggling against and beyond what exists is invariably rooted in struggles within what exists (including identities).
- Full Text: false
- Date Issued: 2016
- Authors: Alexander, Tarryn , Helliker, Kirk D
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/71374 , vital:29838 , https://doi.org/10.1080/02589001.2016.1235353
- Description: This article engages with the autonomist Marxism of John Holloway from a feminist standpoint. The positions developed by this feminist critique are used to shed new light on the land occupations in contemporary Zimbabwe. Though sympathetic to his work, we argue that Holloway does not sufficiently address gender identity with specific reference to social reproduction and women. The notions of the commons and the process of commoning are consistent with Holloway’s autonomist framework and its complementarities to Silvia Federici’s Marxist feminist lens on the commons is highlighted. Against a tendency within autonomist and commoning theories, we argue for a pronounced identitarian politics as grounded in localised struggles undertaken by women as women. We privilege the significance of women asserting and revaluing their identities as part of a possible project of transformation. For us, struggling against and beyond what exists is invariably rooted in struggles within what exists (including identities).
- Full Text: false
- Date Issued: 2016
A late Cretaceous (Maastrichtian) galaxiid fish from South Africa
- Anderson, M Eric, J.L.B. Smith Institute of Ichthyology
- Authors: Anderson, M Eric , J.L.B. Smith Institute of Ichthyology
- Date: 1998-05
- Subjects: Fishes -- Indian Ocean , Flatfishes -- Indian Ocean
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/71000 , vital:29769 , Margaret Smith Library (South African Institute for Aquatic Biodiversity (SAIAB)) Periodicals Margaret Smith Library (South African Institute for Aquatic Biodiversity (SAIAB))
- Description: Online version of original print edition of the Special Publication of the J.L.B. Smith Institute of Ichthyology; No. 60 , A new teleost fish, Stompooria rogersmithi, is described from deposits of a Late Cretaceous crater lake in the Karoo, South Africa. The fossils represent the earliest known species of the recently redefined family Galaxiidae. Distinguishing features include the apposition of the dorsal and anal fins, 41- 42 vertebrae, all neural arches anterior to the dorsal fin origin fused to the centra, presence of epineurals, the opercle reduced above the level of the hyomandibular articulation, the posttemporal and supracleithrum without a connection to the seismosensory head canals, 18 principal caudal fin rays, two epurals, five hypurals, no dorsal outgrowth on the uroneural, the neural spines of the second and third preural centra similar in size, and absence of a stegural, a third uroneural, a mesocoracoid, a supramaxilla, and teeth on the maxilla and palatine bones.
- Full Text:
- Date Issued: 1998-05
- Authors: Anderson, M Eric , J.L.B. Smith Institute of Ichthyology
- Date: 1998-05
- Subjects: Fishes -- Indian Ocean , Flatfishes -- Indian Ocean
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/71000 , vital:29769 , Margaret Smith Library (South African Institute for Aquatic Biodiversity (SAIAB)) Periodicals Margaret Smith Library (South African Institute for Aquatic Biodiversity (SAIAB))
- Description: Online version of original print edition of the Special Publication of the J.L.B. Smith Institute of Ichthyology; No. 60 , A new teleost fish, Stompooria rogersmithi, is described from deposits of a Late Cretaceous crater lake in the Karoo, South Africa. The fossils represent the earliest known species of the recently redefined family Galaxiidae. Distinguishing features include the apposition of the dorsal and anal fins, 41- 42 vertebrae, all neural arches anterior to the dorsal fin origin fused to the centra, presence of epineurals, the opercle reduced above the level of the hyomandibular articulation, the posttemporal and supracleithrum without a connection to the seismosensory head canals, 18 principal caudal fin rays, two epurals, five hypurals, no dorsal outgrowth on the uroneural, the neural spines of the second and third preural centra similar in size, and absence of a stegural, a third uroneural, a mesocoracoid, a supramaxilla, and teeth on the maxilla and palatine bones.
- Full Text:
- Date Issued: 1998-05
A molecular analysis of the Afrotropical Baetidae
- Gattolliat, J L, Monaghan, M T, Sartori, Michel, Elouard, J M, Barber-James, Helen M, Derleth, P, Glaizot, Olivier, de Moor, Ferdy C, Vogler, Alfred P
- Authors: Gattolliat, J L , Monaghan, M T , Sartori, Michel , Elouard, J M , Barber-James, Helen M , Derleth, P , Glaizot, Olivier , de Moor, Ferdy C , Vogler, Alfred P
- Date: 2008
- Language: English
- Type: Text
- Identifier: vital:528 , http://hdl.handle.net/10962/d1008393
- Description: Recent work on the Afrotropical Baetidae has resulted in a number of important taxonomic changes: several polyphyletic genera have been split and more than 30 new Afrotropical genera have been established. In order to test their phylogenetic relevance and to clarify the suprageneric relationships, we reconstructed the first comprehensive molecular phylogeny of the Afrotropical Baetidae. We sequenced a total of ca. 2300 bp from nuclear (18S) and mitochondrial (12S and 16S) gene regions from 65 species belonging to 26 genera. We used three different approaches of phylogeny reconstruction: direct optimization, maximum parsimony and maximum likelihood. The molecular reconstruction indicates the Afrotropical Baetidae require a global revision at a generic as well as suprageneric level. Only four of the 12 genera were monophyletic when represented by more than one species in the analysis. Historically, two conflicting concepts of the suprageneric classification of Afrotropical Baetidae were proposed. One was based on the gathering of sister genera into complexes and the other on the division of the family into a restricted number of subfamilies. According to our reconstruction, neither is completely satisfactory: the major complexes of genera present in Africa are either paraphyletic or polyphyletic and the division of the Afrotropical Baetidae into two subfamilies is probably too simplified.
- Full Text:
- Date Issued: 2008
- Authors: Gattolliat, J L , Monaghan, M T , Sartori, Michel , Elouard, J M , Barber-James, Helen M , Derleth, P , Glaizot, Olivier , de Moor, Ferdy C , Vogler, Alfred P
- Date: 2008
- Language: English
- Type: Text
- Identifier: vital:528 , http://hdl.handle.net/10962/d1008393
- Description: Recent work on the Afrotropical Baetidae has resulted in a number of important taxonomic changes: several polyphyletic genera have been split and more than 30 new Afrotropical genera have been established. In order to test their phylogenetic relevance and to clarify the suprageneric relationships, we reconstructed the first comprehensive molecular phylogeny of the Afrotropical Baetidae. We sequenced a total of ca. 2300 bp from nuclear (18S) and mitochondrial (12S and 16S) gene regions from 65 species belonging to 26 genera. We used three different approaches of phylogeny reconstruction: direct optimization, maximum parsimony and maximum likelihood. The molecular reconstruction indicates the Afrotropical Baetidae require a global revision at a generic as well as suprageneric level. Only four of the 12 genera were monophyletic when represented by more than one species in the analysis. Historically, two conflicting concepts of the suprageneric classification of Afrotropical Baetidae were proposed. One was based on the gathering of sister genera into complexes and the other on the division of the family into a restricted number of subfamilies. According to our reconstruction, neither is completely satisfactory: the major complexes of genera present in Africa are either paraphyletic or polyphyletic and the division of the Afrotropical Baetidae into two subfamilies is probably too simplified.
- Full Text:
- Date Issued: 2008
A passive auxiliary circuit with interphase transformer applied in 12-pulse converters to provide clean power utility interface
- Shih, Der-Chun, Young, Chung-Ming, Whiteley, Chris G
- Authors: Shih, Der-Chun , Young, Chung-Ming , Whiteley, Chris G
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67095 , vital:29031 , https://doi.org/10.1080/02533839.2016.1230029
- Description: publisher version , This paper proposes a passive auxiliary circuit which can be added to an interphase transformer (PAC + IPT) configuration to reduce the total harmonic distortion (THD) existing in 12-pulse diode rectifier converter systems at AC mains. The proposed PAC + IPT compensation method is a simple structure, with low power consumption and requires no extra DC power supply. We present the theoretical analysis of the proposed topology that lessens the total harmonic distortion (THD) and evaluate the dynamic simulation results on a 12-pulse converter system and a 3-kW laboratory prototype. Both the simulation and the experimental results show that the proposed PAC + IPT compensation method can improve the power quality and provide a clean power utility interface of AC line input currents for a conventional 12-pulse diode rectifier converter.
- Full Text: false
- Date Issued: 2016
- Authors: Shih, Der-Chun , Young, Chung-Ming , Whiteley, Chris G
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67095 , vital:29031 , https://doi.org/10.1080/02533839.2016.1230029
- Description: publisher version , This paper proposes a passive auxiliary circuit which can be added to an interphase transformer (PAC + IPT) configuration to reduce the total harmonic distortion (THD) existing in 12-pulse diode rectifier converter systems at AC mains. The proposed PAC + IPT compensation method is a simple structure, with low power consumption and requires no extra DC power supply. We present the theoretical analysis of the proposed topology that lessens the total harmonic distortion (THD) and evaluate the dynamic simulation results on a 12-pulse converter system and a 3-kW laboratory prototype. Both the simulation and the experimental results show that the proposed PAC + IPT compensation method can improve the power quality and provide a clean power utility interface of AC line input currents for a conventional 12-pulse diode rectifier converter.
- Full Text: false
- Date Issued: 2016
A proposed methodology for contextualised evaluation in higher education
- Nygaard, Claus, Belluigi, Dina Z
- Authors: Nygaard, Claus , Belluigi, Dina Z
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/482809 , vital:78691 , https://doi.org/10.1080/02602931003650037
- Description: This paper aims to inspire stakeholders working with quality of higher education (such as members of study boards, study programme directors, curriculum developers and teachers) to critically consider their evaluation methods in relation to a focus on student learning. We argue that many of the existing methods of evaluation in higher education are underpinned by a conception of learning that is de‐contextualised. As a consequence, many data collection methods do not address aspects that affect students’ learning. This is problematic because the core aim of higher education is to facilitate student learning. We propose a contextualised evaluation methodology, guided by 10 key questions, which can help evaluators address concepts and questions of student learning in their evaluations.
- Full Text:
- Date Issued: 2010
- Authors: Nygaard, Claus , Belluigi, Dina Z
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/482809 , vital:78691 , https://doi.org/10.1080/02602931003650037
- Description: This paper aims to inspire stakeholders working with quality of higher education (such as members of study boards, study programme directors, curriculum developers and teachers) to critically consider their evaluation methods in relation to a focus on student learning. We argue that many of the existing methods of evaluation in higher education are underpinned by a conception of learning that is de‐contextualised. As a consequence, many data collection methods do not address aspects that affect students’ learning. This is problematic because the core aim of higher education is to facilitate student learning. We propose a contextualised evaluation methodology, guided by 10 key questions, which can help evaluators address concepts and questions of student learning in their evaluations.
- Full Text:
- Date Issued: 2010
A qualitative ecological risk assessment of the invasive Nile tilapia, Oreochromis niloticus in a sub-tropical African river system (Limpopo River, South Africa)
- Zengeya, Tsungai A, Robertson, Mark P, Booth, Anthony J, Chimimba, Christian T
- Authors: Zengeya, Tsungai A , Robertson, Mark P , Booth, Anthony J , Chimimba, Christian T
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123575 , vital:35457 , https://doi.10.1002/aqc.2258
- Description: 1. This study outlines the development of a qualitative risk assessment method and its application as a screening tool for determining the risk of establishment and spread of the invasive Nile tilapia, Oreochromis niloticus (Linnaeus, 1758), within the central sub-catchment of the Limpopo River basin in northern South Africa. 2. The assessment used known physiological tolerance limits of O. niloticus in relation to minimum water temperature, presence or absence of dams, seasonality of river flows, and the presence of indigenous fish species of concern to identify river systems that would be suitable for O. niloticus establishment. 3. River sections along the Limpopo main river channel and the immediate reaches of its associated tributaries east of the Limpopo/Lephalala river confluence along the Botswana–South Africa–Zimbabwe border were identified as being highly vulnerable to O. niloticus invasion. Rivers in the upper Bushveld catchment (Upper Limpopo, Mogalakwena, Lephalala, Mokolo, Matlabas and Crocodile rivers) were categorized as of medium ecological risk, while headwater streams were considered to be of low ecological risk. The decrease in vulnerability between lowveld and highveld river sections was mainly a function of low water temperatures (8–12˚C) associated with increasing altitude. 4. Oreochromis niloticus is already established in the lower catchment of the Limpopo River basin where indigenous congenerics are at an extinction risk through hybridization and competition exclusion. Oreochromis niloticus, therefore, poses an ecologically unacceptable risk to river systems in the upper catchment where it is yet to establish. The current risk assessment model provides a useful preliminary framework for the identification of river systems that are vulnerable to an O. niloticus invasion where conservation measures should be directed and implemented to prevent its introduction and spread within the Limpopo river system.
- Full Text:
- Date Issued: 2013
- Authors: Zengeya, Tsungai A , Robertson, Mark P , Booth, Anthony J , Chimimba, Christian T
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123575 , vital:35457 , https://doi.10.1002/aqc.2258
- Description: 1. This study outlines the development of a qualitative risk assessment method and its application as a screening tool for determining the risk of establishment and spread of the invasive Nile tilapia, Oreochromis niloticus (Linnaeus, 1758), within the central sub-catchment of the Limpopo River basin in northern South Africa. 2. The assessment used known physiological tolerance limits of O. niloticus in relation to minimum water temperature, presence or absence of dams, seasonality of river flows, and the presence of indigenous fish species of concern to identify river systems that would be suitable for O. niloticus establishment. 3. River sections along the Limpopo main river channel and the immediate reaches of its associated tributaries east of the Limpopo/Lephalala river confluence along the Botswana–South Africa–Zimbabwe border were identified as being highly vulnerable to O. niloticus invasion. Rivers in the upper Bushveld catchment (Upper Limpopo, Mogalakwena, Lephalala, Mokolo, Matlabas and Crocodile rivers) were categorized as of medium ecological risk, while headwater streams were considered to be of low ecological risk. The decrease in vulnerability between lowveld and highveld river sections was mainly a function of low water temperatures (8–12˚C) associated with increasing altitude. 4. Oreochromis niloticus is already established in the lower catchment of the Limpopo River basin where indigenous congenerics are at an extinction risk through hybridization and competition exclusion. Oreochromis niloticus, therefore, poses an ecologically unacceptable risk to river systems in the upper catchment where it is yet to establish. The current risk assessment model provides a useful preliminary framework for the identification of river systems that are vulnerable to an O. niloticus invasion where conservation measures should be directed and implemented to prevent its introduction and spread within the Limpopo river system.
- Full Text:
- Date Issued: 2013
A research prospectus for the humanities
- Authors: Wright, Laurence
- Date: 2006
- Language: English
- Type: Book chapter , text
- Identifier: vital:7027 , http://hdl.handle.net/10962/d1007213
- Description: The humanities in South Africa, as elsewhere, face a crisis of credibility.There is pressing need for the humanities to articulate their social and educational purpose more clearly, so that their academic value is recognised beyond the confines of academia.The aim of reshaping human character and society remains the foundational impulse of the humanities. This is achieved through the careful study of specially selected exemplary 'texts': literary works, fine art, social schemes, intellectual movements, historical episodes, and philosophical and religious outlooks.Students are required to respond in person to both 'text' and the discourse of which it is an exemplary instantiation. This is the manner in which they act to influence character and society.
- Full Text:
- Date Issued: 2006
- Authors: Wright, Laurence
- Date: 2006
- Language: English
- Type: Book chapter , text
- Identifier: vital:7027 , http://hdl.handle.net/10962/d1007213
- Description: The humanities in South Africa, as elsewhere, face a crisis of credibility.There is pressing need for the humanities to articulate their social and educational purpose more clearly, so that their academic value is recognised beyond the confines of academia.The aim of reshaping human character and society remains the foundational impulse of the humanities. This is achieved through the careful study of specially selected exemplary 'texts': literary works, fine art, social schemes, intellectual movements, historical episodes, and philosophical and religious outlooks.Students are required to respond in person to both 'text' and the discourse of which it is an exemplary instantiation. This is the manner in which they act to influence character and society.
- Full Text:
- Date Issued: 2006
A revision of the Pyura stolonifera species complex (Tunicata, Ascidiacea), with a description of a new species from Australia
- Authors: Teske, Peter R , Ruis, Marc
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/445654 , vital:74411 , https://www.biotaxa.org/Zootaxa/article/view/zootaxa.2754.1.2
- Description: Pyura stolonifera is a large solitary ascidian found in Africa, Australasia and South America. The taxonomic status of different populations of this species is disputed, especially since there is evidence for several distinct morphological and genetic units that point towards the existence of multiple cryptic species. While some researchers still recognize P. stolonifera as a single species, others treat the different populations as distinct species. Here, we present a revision of the P. stolonifera species complex based on the examination of samples from all regions where there are reliable reports of this taxon. We recognize four species that are both morphologically and genetically distinct, one of which is new to science and is formally described here. This species is morphologically distinct from the other three members of the species complex in terms of the colour and texture of the tunic, the arrangement of the gonads within the gut and the shape of the dorsal tubercle, among other characters. We name the new species Pyura dalbyi after Dr. J.E. Dalby Jr., whose research on its ecology and distribution provided the incentive for examining this species more closely.
- Full Text:
- Date Issued: 2011
- Authors: Teske, Peter R , Ruis, Marc
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/445654 , vital:74411 , https://www.biotaxa.org/Zootaxa/article/view/zootaxa.2754.1.2
- Description: Pyura stolonifera is a large solitary ascidian found in Africa, Australasia and South America. The taxonomic status of different populations of this species is disputed, especially since there is evidence for several distinct morphological and genetic units that point towards the existence of multiple cryptic species. While some researchers still recognize P. stolonifera as a single species, others treat the different populations as distinct species. Here, we present a revision of the P. stolonifera species complex based on the examination of samples from all regions where there are reliable reports of this taxon. We recognize four species that are both morphologically and genetically distinct, one of which is new to science and is formally described here. This species is morphologically distinct from the other three members of the species complex in terms of the colour and texture of the tunic, the arrangement of the gonads within the gut and the shape of the dorsal tubercle, among other characters. We name the new species Pyura dalbyi after Dr. J.E. Dalby Jr., whose research on its ecology and distribution provided the incentive for examining this species more closely.
- Full Text:
- Date Issued: 2011
A search for enhanced photodynamic activity against Staphylococcus aureus planktonic cells and biofilms: the evaluation of phthalocyanine–detonation nanodiamond–Ag nanoconjugates
- Openda, Yolande Ikala, Matshitse, Refilwe, Nyokong, Tebello
- Authors: Openda, Yolande Ikala , Matshitse, Refilwe , Nyokong, Tebello
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/163825 , vital:41073 , DOI: 10.1039/D0PP00075B
- Description: The present work reports on the synthesis and characterization of novel zinc (2) and indium (3) 2-amino-4-bromophenoxy substituted phthalocyanines (Pcs) along with the self-assembled nanoconjugates formed via π–π stacking interaction onto detonation nanodiamonds (DNDs) to form 2@DNDs and 3@DNDs. 2@DNDs and 3@DNDs were covalently linked to chitosan–silver mediated nanoparticles (CSAg) to form 2@DNDs-CSAg and 3@DNDs-CSAg nanoconjugates. High singlet oxygen quantum yields in DMSO of 0.69 and 0.72 for Pcs alone and 0.90 and 0.92 for 2@DNDs-CSAg and 3@DNDs-CSAg, respectively, were obtained.
- Full Text:
- Date Issued: 2020
- Authors: Openda, Yolande Ikala , Matshitse, Refilwe , Nyokong, Tebello
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/163825 , vital:41073 , DOI: 10.1039/D0PP00075B
- Description: The present work reports on the synthesis and characterization of novel zinc (2) and indium (3) 2-amino-4-bromophenoxy substituted phthalocyanines (Pcs) along with the self-assembled nanoconjugates formed via π–π stacking interaction onto detonation nanodiamonds (DNDs) to form 2@DNDs and 3@DNDs. 2@DNDs and 3@DNDs were covalently linked to chitosan–silver mediated nanoparticles (CSAg) to form 2@DNDs-CSAg and 3@DNDs-CSAg nanoconjugates. High singlet oxygen quantum yields in DMSO of 0.69 and 0.72 for Pcs alone and 0.90 and 0.92 for 2@DNDs-CSAg and 3@DNDs-CSAg, respectively, were obtained.
- Full Text:
- Date Issued: 2020
A survey of fruit-feeding insects and their parasitoids occurring on wild olives, Olea europaea ssp. cuspidata, in the Eastern Cape of South Africa
- Mkize, Nolwazi, Hoelmer, Kim A, Villet, Martin H
- Authors: Mkize, Nolwazi , Hoelmer, Kim A , Villet, Martin H
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/441694 , vital:73907 , https://doi.org/10.1080/09583150802450154
- Description: Fruits of wild olives, Olea europaea ssp. cuspidata (Wall. ex G. Don) Cif., were collected in the Eastern Cape, South Africa, during 2003–2005 to quantify levels of fruit-infesting pests and their parasitoids. Two species of Tephritidae, Bactrocera oleae (Rossi) and B. biguttula (Bezzi), were the most abundant insects recovered and were reared from most samples. Fruit infestation rates by the Bactrocera spp. were generally below 8% and over half of the infestations were under 1%. When parasitism occurred in samples with flies, levels ranged from 7 to 83%. Several species of opiine braconid wasps, Psyttalia concolor (Szépligeti), Psyttalia lounsburyi (Silvestri), and Utetes africanus (Szépligeti) and one braconine wasp, Bracon celer Szépligeti, were reared from fruits containing B. oleae and/or B. biguttula. Chalcidoid parasitoids and seed wasps included seven species of Eurytomidae (Eurytoma oleae, Eurytoma sp., and Sycophila sp.), Ormyridae (Ormyrus sp.), Torymidae (Megastigmus sp.), and Eupelmidae (Eupelmus afer and E. spermophilus). One species of moth, Palpita unionalis (Hübner) (Crambidae), was recovered in very low numbers and without parasitoids. The survey results indicate that fruit flies might not become economic pests of the nascent commercial olive industry in the Eastern Cape, and the small numbers present may be controlled to a considerable level by natural enemies.
- Full Text:
- Date Issued: 2008
- Authors: Mkize, Nolwazi , Hoelmer, Kim A , Villet, Martin H
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/441694 , vital:73907 , https://doi.org/10.1080/09583150802450154
- Description: Fruits of wild olives, Olea europaea ssp. cuspidata (Wall. ex G. Don) Cif., were collected in the Eastern Cape, South Africa, during 2003–2005 to quantify levels of fruit-infesting pests and their parasitoids. Two species of Tephritidae, Bactrocera oleae (Rossi) and B. biguttula (Bezzi), were the most abundant insects recovered and were reared from most samples. Fruit infestation rates by the Bactrocera spp. were generally below 8% and over half of the infestations were under 1%. When parasitism occurred in samples with flies, levels ranged from 7 to 83%. Several species of opiine braconid wasps, Psyttalia concolor (Szépligeti), Psyttalia lounsburyi (Silvestri), and Utetes africanus (Szépligeti) and one braconine wasp, Bracon celer Szépligeti, were reared from fruits containing B. oleae and/or B. biguttula. Chalcidoid parasitoids and seed wasps included seven species of Eurytomidae (Eurytoma oleae, Eurytoma sp., and Sycophila sp.), Ormyridae (Ormyrus sp.), Torymidae (Megastigmus sp.), and Eupelmidae (Eupelmus afer and E. spermophilus). One species of moth, Palpita unionalis (Hübner) (Crambidae), was recovered in very low numbers and without parasitoids. The survey results indicate that fruit flies might not become economic pests of the nascent commercial olive industry in the Eastern Cape, and the small numbers present may be controlled to a considerable level by natural enemies.
- Full Text:
- Date Issued: 2008
A Theoretical Framework for Professional Development in a South African University
- Authors: Quinn, Lynn
- Date: 2003
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/484164 , vital:78875 , https://doi.org/10.1080/1360144042000277946
- Description: The changing context of higher education both internationally and in South Africa has presented challenges to lecturers that have led in some institutions to the introduction of accredited professional development courses for academics. Such courses for university lecturers are relatively new in South Africa. This paper reports on research in progress on a Post Graduate Certificate in Higher Education and Training course offered at Rhodes University in South Africa. It highlights some important questions that have arisen on the ways in which the theoretical framework of the course has or has not met the needs of diverse groups of lecturers within the specific South African context. A central theme of the course is that of the critically reflective practitioner. Lecturers are encouraged to explore the ontological and epistemological underpinnings of their disciplines and to examine the philosophical assumptions of their espoused theories about teaching and learning as well as their teaching practice. The theoretical framework has been found to be most successful for more experienced academics. However, the author raises some important questions regarding the suitability of this framework in relation to the specific post‐apartheid context in which the course operates, specifically whether the course prepares lecturers to open up both “actual” and “epistemological” access to all the students at the university.
- Full Text:
- Date Issued: 2003
- Authors: Quinn, Lynn
- Date: 2003
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/484164 , vital:78875 , https://doi.org/10.1080/1360144042000277946
- Description: The changing context of higher education both internationally and in South Africa has presented challenges to lecturers that have led in some institutions to the introduction of accredited professional development courses for academics. Such courses for university lecturers are relatively new in South Africa. This paper reports on research in progress on a Post Graduate Certificate in Higher Education and Training course offered at Rhodes University in South Africa. It highlights some important questions that have arisen on the ways in which the theoretical framework of the course has or has not met the needs of diverse groups of lecturers within the specific South African context. A central theme of the course is that of the critically reflective practitioner. Lecturers are encouraged to explore the ontological and epistemological underpinnings of their disciplines and to examine the philosophical assumptions of their espoused theories about teaching and learning as well as their teaching practice. The theoretical framework has been found to be most successful for more experienced academics. However, the author raises some important questions regarding the suitability of this framework in relation to the specific post‐apartheid context in which the course operates, specifically whether the course prepares lecturers to open up both “actual” and “epistemological” access to all the students at the university.
- Full Text:
- Date Issued: 2003
A Trypanosoma cruzi heat shock protein 40 is able to stimulate the adenosine triphosphate hydrolysis activity of heat shock protein 70 and can substitute for a yeast heat shock protein 40
- Edkins, Adrienne L, Ludewig, Michael H, Blatch, Gregory L
- Authors: Edkins, Adrienne L , Ludewig, Michael H , Blatch, Gregory L
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6465 , http://hdl.handle.net/10962/d1005794 , http://dx.doi.org/10.1016/j.biocel.2004.01.016
- Description: The process of assisted protein folding, characteristic of members of the heat shock protein 70 (Hsp70) and heat shock protein 40 (Hsp40) molecular chaperone families, is important for maintaining the structural integrity of cellular protein machinery under normal and stressful conditions. Hsp70 and Hsp40 cooperate to bind non-native protein conformations in a process of adenosine triphosphate (ATP)-regulated assisted protein folding. We have analysed the molecular chaperone activity of the cytoplasmic inducible Hsp70 from Trypanosoma cruzi (TcHsp70) and its interactions with its potential partner Hsp40s (T. cruzi DnaJ protein 1 [Tcj1] and T. cruzi DnaJ protein 2 [Tcj2]). Histidine-tagged TcHsp70 (His-TcHsp70), Tcj1 (Tcj1-His) and Tcj2 (His-Tcj2) were over-produced in Escherichia coli and purified by nickel affinity chromatography. The in vitro basal specific ATP hydrolysis activity (ATPase activity) of His-TcHsp70 was determined as 40 nmol phosphate/min/mg protein, significantly higher than that reported for other Hsp70s. The basal specific ATPase activity was stimulated to a maximal level of 60 nmol phosphate/min/mg protein in the presence of His-Tcj2 and a model substrate, reduced carboxymethylated α-lactalbumin. In vivo complementation assays showed that Tcj2 was able to overcome the temperature sensitivity of the ydj1 mutant Saccharomyces cerevisiae strain JJ160, suggesting that Tcj2 may be functionally equivalent to the yeast Hsp40 homologue (yeast DnaJ protein 1, Ydj1). These data suggest that Tcj2 is involved in cytoprotection in a similar fashion to Ydj1, and that TcHsp70 and Tcj2 may interact in a nucleotide-regulated process of chaperone-assisted protein folding.
- Full Text:
- Date Issued: 2004
- Authors: Edkins, Adrienne L , Ludewig, Michael H , Blatch, Gregory L
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6465 , http://hdl.handle.net/10962/d1005794 , http://dx.doi.org/10.1016/j.biocel.2004.01.016
- Description: The process of assisted protein folding, characteristic of members of the heat shock protein 70 (Hsp70) and heat shock protein 40 (Hsp40) molecular chaperone families, is important for maintaining the structural integrity of cellular protein machinery under normal and stressful conditions. Hsp70 and Hsp40 cooperate to bind non-native protein conformations in a process of adenosine triphosphate (ATP)-regulated assisted protein folding. We have analysed the molecular chaperone activity of the cytoplasmic inducible Hsp70 from Trypanosoma cruzi (TcHsp70) and its interactions with its potential partner Hsp40s (T. cruzi DnaJ protein 1 [Tcj1] and T. cruzi DnaJ protein 2 [Tcj2]). Histidine-tagged TcHsp70 (His-TcHsp70), Tcj1 (Tcj1-His) and Tcj2 (His-Tcj2) were over-produced in Escherichia coli and purified by nickel affinity chromatography. The in vitro basal specific ATP hydrolysis activity (ATPase activity) of His-TcHsp70 was determined as 40 nmol phosphate/min/mg protein, significantly higher than that reported for other Hsp70s. The basal specific ATPase activity was stimulated to a maximal level of 60 nmol phosphate/min/mg protein in the presence of His-Tcj2 and a model substrate, reduced carboxymethylated α-lactalbumin. In vivo complementation assays showed that Tcj2 was able to overcome the temperature sensitivity of the ydj1 mutant Saccharomyces cerevisiae strain JJ160, suggesting that Tcj2 may be functionally equivalent to the yeast Hsp40 homologue (yeast DnaJ protein 1, Ydj1). These data suggest that Tcj2 is involved in cytoprotection in a similar fashion to Ydj1, and that TcHsp70 and Tcj2 may interact in a nucleotide-regulated process of chaperone-assisted protein folding.
- Full Text:
- Date Issued: 2004
Access to educational resources: illustrative examples from rural schools in the Eastern Cape Province
- Authors: Hendricks, Monica
- Date: 2008
- Language: English
- Type: Book chapter
- Identifier: vital:7020 , http://hdl.handle.net/10962/d1007200
- Description: [Introduction] This chapter looks at the causes and effects of the widely varying degree of access to material resources across schools in the Eastern Cape. Starting with a broad overview of schools and classroom resources across the whole province, I go on to examine the Grahamstown education district. I discuss the inequalities in resource provision between groupings of schools in the district: comparing independent and state schools, and also examining disparities across schools in different localities within the government sector. The role of parents in providing resources for their children’s schooling is also discussed, as are the relationships among the various participants in education, such as non-governmental organisations, officials of the Department of Education, and teachers.
- Full Text:
- Date Issued: 2008
- Authors: Hendricks, Monica
- Date: 2008
- Language: English
- Type: Book chapter
- Identifier: vital:7020 , http://hdl.handle.net/10962/d1007200
- Description: [Introduction] This chapter looks at the causes and effects of the widely varying degree of access to material resources across schools in the Eastern Cape. Starting with a broad overview of schools and classroom resources across the whole province, I go on to examine the Grahamstown education district. I discuss the inequalities in resource provision between groupings of schools in the district: comparing independent and state schools, and also examining disparities across schools in different localities within the government sector. The role of parents in providing resources for their children’s schooling is also discussed, as are the relationships among the various participants in education, such as non-governmental organisations, officials of the Department of Education, and teachers.
- Full Text:
- Date Issued: 2008
Activated carbon from lignocellulosic waste residues: effect of activating agent on porosity characteristics and use as adsorbents for organic species
- Olorundare, O F, Okonkwo, J O, Msagati, T A M, Mamba, Bhekie B, Krause, Rui W M
- Authors: Olorundare, O F , Okonkwo, J O , Msagati, T A M , Mamba, Bhekie B , Krause, Rui W M
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125233 , vital:35748 , https://doi.org/10.1007/s11270-014-1876-2
- Description: This paper reports on the effect of activating agents such as the impregnation ratio of phosphoric acid (1:1–1:5) at constant activation temperature on the performance of porous activated carbon from waste residues (maize tassel). The variation in the impregnation ratio of the produced activated carbon (AC) from 1:1 to 1:5 enabled the preparation of a high surface area (1,263 m2/g) and a large pore volume (1.592 cm3/g) of AC produced from maize tassel (MT) using a convectional chemical activating agent (phosphoric acid). Impregnation ratios (IR) of the precursors were varied between 1:1 and 1:5 in which it was found that the ratio of 1:4 was optimal based on the high surface area, while 1:5 has the optimal pore volume value for the produced activated carbon.
- Full Text:
- Date Issued: 2014
- Authors: Olorundare, O F , Okonkwo, J O , Msagati, T A M , Mamba, Bhekie B , Krause, Rui W M
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125233 , vital:35748 , https://doi.org/10.1007/s11270-014-1876-2
- Description: This paper reports on the effect of activating agents such as the impregnation ratio of phosphoric acid (1:1–1:5) at constant activation temperature on the performance of porous activated carbon from waste residues (maize tassel). The variation in the impregnation ratio of the produced activated carbon (AC) from 1:1 to 1:5 enabled the preparation of a high surface area (1,263 m2/g) and a large pore volume (1.592 cm3/g) of AC produced from maize tassel (MT) using a convectional chemical activating agent (phosphoric acid). Impregnation ratios (IR) of the precursors were varied between 1:1 and 1:5 in which it was found that the ratio of 1:4 was optimal based on the high surface area, while 1:5 has the optimal pore volume value for the produced activated carbon.
- Full Text:
- Date Issued: 2014