Assessment of water quality based on diatom indices in a small temperate river system, Kowie River, South Africa
- Dalu, Tatenda, Bere, Taurai, Froneman, P William
- Authors: Dalu, Tatenda , Bere, Taurai , Froneman, P William
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123896 , vital:35514 , http://dx.doi.org/10.4314/wsa.v42i2.02
- Description: This study aimed to assess the impact of land use patterns on water quality and benthic diatom community structure and to test the applicability of diatom indices developed in other regions of the world to a small temperate southern African river system. Sampling was conducted at eight study sites along the length of the river on four separate occasions. Multivariate data analyses were performed on the diatom community dataset to specify the main gradients of floristic variation and to detect and visualize similarities in diatom samples in relation to land-use patterns within the catchment. One hundred and twelve (112) diatom species belonging to 36 genera were recorded during the study. Canonical correspondence analysis (CCA) demonstrated that variations in the benthic diatom community structure were best explained by ammonium, nitrate, conductivity, pH, temperature, resistivity and water flow. OMNIDIA was used for calculation of selected diatom water quality indices. A number of the indices, e.g., the trophic diatom index (TDI), eutrophication/pollution index and biological index of water quality (BIWQ), either under- or over-estimated the water quality of the system. With few exceptions, there were no significant correlations (p> 0.05) between the diatom indices’ values and the nutrient variables. The absence of any significant correlations between the diatom indices’ values and selected physico-chemical variables suggests that indices developed in other regions of the world may not be suitable for temperate southern African rivers.
- Full Text:
- Date Issued: 2016
- Authors: Dalu, Tatenda , Bere, Taurai , Froneman, P William
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123896 , vital:35514 , http://dx.doi.org/10.4314/wsa.v42i2.02
- Description: This study aimed to assess the impact of land use patterns on water quality and benthic diatom community structure and to test the applicability of diatom indices developed in other regions of the world to a small temperate southern African river system. Sampling was conducted at eight study sites along the length of the river on four separate occasions. Multivariate data analyses were performed on the diatom community dataset to specify the main gradients of floristic variation and to detect and visualize similarities in diatom samples in relation to land-use patterns within the catchment. One hundred and twelve (112) diatom species belonging to 36 genera were recorded during the study. Canonical correspondence analysis (CCA) demonstrated that variations in the benthic diatom community structure were best explained by ammonium, nitrate, conductivity, pH, temperature, resistivity and water flow. OMNIDIA was used for calculation of selected diatom water quality indices. A number of the indices, e.g., the trophic diatom index (TDI), eutrophication/pollution index and biological index of water quality (BIWQ), either under- or over-estimated the water quality of the system. With few exceptions, there were no significant correlations (p> 0.05) between the diatom indices’ values and the nutrient variables. The absence of any significant correlations between the diatom indices’ values and selected physico-chemical variables suggests that indices developed in other regions of the world may not be suitable for temperate southern African rivers.
- Full Text:
- Date Issued: 2016
Comparative photophysicochemical behavior of nanoconjugates of indium tetracarboxyphenoxy phthalocyanines covalently linked to CdTe/ZnSe/ZnO quantum dots
- Oluwole, David O, Nyokong, Tebello
- Authors: Oluwole, David O , Nyokong, Tebello
- Date: 2015
- Language: English
- Type: text , Article
- Identifier: vital:7294 , http://hdl.handle.net/10962/d1020357 , http://dx.doi.org/10.1016/j.jphotochem.2015.07.009
- Description: This work reports on the photophysicochemical behavior of different nanoconjugates of core/shell/shell (GSH-CdTe/ZnSe/ZnO), core/shell (GSH-CdTe/ZnSe) and core (GSH-CdTe) (quantum dots QDs) with indium tetracarboxyphenoxy phthalocyanines ((OH)InTCPPc) in dimethylsulfoxide. The fluorescence quantum yields (Φf) and lifetimes (τf, in brackets) of QDs ranged from 0.20 (13.9 ns) to 0.42 (25.6 ns). The highest Φf value was obtained for GSH-CdTe/ZnSe/ZnO (4.5) while the least was observed in GSH-CdTe/ZnSe/ZnO (7.6), the numbers in brackets refer to the sizes. For (OH)InTCPPc alone a Φf and τf values of 0.02 and 2.43 ns, respectively were obtained. In the nanoconjugates, pivotal decrease in the Φf and τf of the QDs were observed with increase in the triplet and singlet oxygen quantum yields of (OH)InTCPPc. , Original publication is available at http://dx.doi.org/10.1016/j.jphotochem.2015.07.009
- Full Text: false
- Date Issued: 2015
- Authors: Oluwole, David O , Nyokong, Tebello
- Date: 2015
- Language: English
- Type: text , Article
- Identifier: vital:7294 , http://hdl.handle.net/10962/d1020357 , http://dx.doi.org/10.1016/j.jphotochem.2015.07.009
- Description: This work reports on the photophysicochemical behavior of different nanoconjugates of core/shell/shell (GSH-CdTe/ZnSe/ZnO), core/shell (GSH-CdTe/ZnSe) and core (GSH-CdTe) (quantum dots QDs) with indium tetracarboxyphenoxy phthalocyanines ((OH)InTCPPc) in dimethylsulfoxide. The fluorescence quantum yields (Φf) and lifetimes (τf, in brackets) of QDs ranged from 0.20 (13.9 ns) to 0.42 (25.6 ns). The highest Φf value was obtained for GSH-CdTe/ZnSe/ZnO (4.5) while the least was observed in GSH-CdTe/ZnSe/ZnO (7.6), the numbers in brackets refer to the sizes. For (OH)InTCPPc alone a Φf and τf values of 0.02 and 2.43 ns, respectively were obtained. In the nanoconjugates, pivotal decrease in the Φf and τf of the QDs were observed with increase in the triplet and singlet oxygen quantum yields of (OH)InTCPPc. , Original publication is available at http://dx.doi.org/10.1016/j.jphotochem.2015.07.009
- Full Text: false
- Date Issued: 2015
From linguistic determinism to technological determinism
- Kaschula, Russell H, Mostert, Andre M
- Authors: Kaschula, Russell H , Mostert, Andre M
- Date: 2015
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/67062 , vital:29027 , https://doi.org/10.4018/978-1-4666-5888-2.ch447
- Description: publisher version , From Introduction: This article seeks to analyse the link between linguistic determinism, the notion that language determines our thought and the way we perceive our reality, as espoused by the Sapir-Whorf hypothesis, and contemporary technological determinism. Arguably this link takes place within a global context where equal access to technology is not yet guaranteed. Ellul (1964) and Lawson’s (2004) observations create an interesting metaphor in terms of the technological beast staring down human society. The overwhelming response if we accept Lawson’s observation is complacency at best or downright naivety at worst regarding the impact of technology on our thinking. Lawson made his observation in the pre-Facebook era and subsequent literature is now much more focused on all aspects of technology within our contemporary milieu. Technology is now totally ubiquitous in the developed world and becoming more so in developing countries, albeit with a much stronger mobile bias for early technology adopters. That technology is rushing ahead of many individuals and institutions is almost an aphorism with many lagging in its wake. This lag as recognised by Brynjolfson and McAfree (2011) has wide social and economic implications for all members of society, in the case of business those that do not keep up go under. A further pertinent question revolves around how individuals who start from low technological literacy levels or do not keep pace with technological developments are impacted. Dlutu (2013) assesses for example the impact of social network sites on the isiXhosa language and culture in both a rural and urban area of South Africa. Furthermore one may then ask how this technological milieu impacts on the general aspects of the day to day lives and thinking of all members of a society. This gives rise to the concept of technological determinism which in its simplest form states ‘that technology has important effects on our lives’ (Adler, 2008, p. 537). This is far too simplistic when the contemporaneous technological developments are assessed. Adler (2008, p. 537) goes further and recognizes ‘that technology itself is socially determined…and social structures co-evolve in a non-deterministic, emergent process…the effects of any given technology depend mainly on how it is implemented which in turn is socially determined’ (Adler, 2008, p. 537). Engaging this socially determined application of technology can be advanced when the relationship with language and language determinism is considered. Moreover, it is the interplay between technology and language that gives rise to the emerging concept of a language singularity which is brought about by a form of technological determinism. This article seeks to explore the possible effects of rapid technological development on human interaction, language and culture in a ‘globalized’ world which has unequal access to literacy and technology. Furthermore, the article explores the link between language, culture, thought and technology and the type of linguistic and technological determinism that we can anticipate.
- Full Text: false
- Date Issued: 2015
- Authors: Kaschula, Russell H , Mostert, Andre M
- Date: 2015
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/67062 , vital:29027 , https://doi.org/10.4018/978-1-4666-5888-2.ch447
- Description: publisher version , From Introduction: This article seeks to analyse the link between linguistic determinism, the notion that language determines our thought and the way we perceive our reality, as espoused by the Sapir-Whorf hypothesis, and contemporary technological determinism. Arguably this link takes place within a global context where equal access to technology is not yet guaranteed. Ellul (1964) and Lawson’s (2004) observations create an interesting metaphor in terms of the technological beast staring down human society. The overwhelming response if we accept Lawson’s observation is complacency at best or downright naivety at worst regarding the impact of technology on our thinking. Lawson made his observation in the pre-Facebook era and subsequent literature is now much more focused on all aspects of technology within our contemporary milieu. Technology is now totally ubiquitous in the developed world and becoming more so in developing countries, albeit with a much stronger mobile bias for early technology adopters. That technology is rushing ahead of many individuals and institutions is almost an aphorism with many lagging in its wake. This lag as recognised by Brynjolfson and McAfree (2011) has wide social and economic implications for all members of society, in the case of business those that do not keep up go under. A further pertinent question revolves around how individuals who start from low technological literacy levels or do not keep pace with technological developments are impacted. Dlutu (2013) assesses for example the impact of social network sites on the isiXhosa language and culture in both a rural and urban area of South Africa. Furthermore one may then ask how this technological milieu impacts on the general aspects of the day to day lives and thinking of all members of a society. This gives rise to the concept of technological determinism which in its simplest form states ‘that technology has important effects on our lives’ (Adler, 2008, p. 537). This is far too simplistic when the contemporaneous technological developments are assessed. Adler (2008, p. 537) goes further and recognizes ‘that technology itself is socially determined…and social structures co-evolve in a non-deterministic, emergent process…the effects of any given technology depend mainly on how it is implemented which in turn is socially determined’ (Adler, 2008, p. 537). Engaging this socially determined application of technology can be advanced when the relationship with language and language determinism is considered. Moreover, it is the interplay between technology and language that gives rise to the emerging concept of a language singularity which is brought about by a form of technological determinism. This article seeks to explore the possible effects of rapid technological development on human interaction, language and culture in a ‘globalized’ world which has unequal access to literacy and technology. Furthermore, the article explores the link between language, culture, thought and technology and the type of linguistic and technological determinism that we can anticipate.
- Full Text: false
- Date Issued: 2015
Impact of marine inundation after a period of drought on the lakeshore vegetation of Lake St Lucia, South Africa: resilience of estuarine vegetation
- Sieben, E J J, Ellery, William F N, Dullo, B W, Grootjans, A P
- Authors: Sieben, E J J , Ellery, William F N , Dullo, B W , Grootjans, A P
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/144443 , vital:38346 , DOI: 10.2989/16085914.2015.1032208
- Description: The shore of Lake St Lucia in the vicinity of Catalina Bay, in the southern part of the lake, receives freshwater input as surface and groundwater seepage from the adjacent elevated coastal plain. Vegetation, water quality and landform were recorded on the lakeshore and on the dry lakebed near one of these seepage zones. This was done along a gradient perpendicular to the lakeshore and along the lakeshore away from the fluvial source of freshwater input. A number of plant communities were found along a gradient of water salinity from the shoreline (fresh water) towards the centre of the lake, and also away from the fluvial input of water (increasingly saline). Species richness decreased with increasing salinity. The first study was conducted in 2006 after a prolonged drought associated with low lake levels and closure of the mouth, and repeated again in 2010 three years after breaching of the estuarine mouth by a tropical cyclone at sea, which caused inundation of the partly dry lakebed with sea water. The vegetation of the lakeshore after these major disturbances was remarkably similar in the two time periods, suggesting rapid recovery near freshwater seepage zones, following an influx of sea water.
- Full Text:
- Date Issued: 2015
- Authors: Sieben, E J J , Ellery, William F N , Dullo, B W , Grootjans, A P
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/144443 , vital:38346 , DOI: 10.2989/16085914.2015.1032208
- Description: The shore of Lake St Lucia in the vicinity of Catalina Bay, in the southern part of the lake, receives freshwater input as surface and groundwater seepage from the adjacent elevated coastal plain. Vegetation, water quality and landform were recorded on the lakeshore and on the dry lakebed near one of these seepage zones. This was done along a gradient perpendicular to the lakeshore and along the lakeshore away from the fluvial source of freshwater input. A number of plant communities were found along a gradient of water salinity from the shoreline (fresh water) towards the centre of the lake, and also away from the fluvial input of water (increasingly saline). Species richness decreased with increasing salinity. The first study was conducted in 2006 after a prolonged drought associated with low lake levels and closure of the mouth, and repeated again in 2010 three years after breaching of the estuarine mouth by a tropical cyclone at sea, which caused inundation of the partly dry lakebed with sea water. The vegetation of the lakeshore after these major disturbances was remarkably similar in the two time periods, suggesting rapid recovery near freshwater seepage zones, following an influx of sea water.
- Full Text:
- Date Issued: 2015
The development of Palladium(II)-specific amine-functionalized silica-based microparticles : adsorption and column separation studies
- Fayemi, Omolola E, Ogunlaja, Adeniyi S, Antunes, Edith M, Nyokong, Tebello, Tshentu, Zenixole R
- Authors: Fayemi, Omolola E , Ogunlaja, Adeniyi S , Antunes, Edith M , Nyokong, Tebello , Tshentu, Zenixole R
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:7270 , http://hdl.handle.net/10962/d1020285
- Description: The adsorption and separation of platinum(IV) and palladium(II) chlorido species ([PtCl6]2− and [PdCl4]2−) on silica-based microparticles functionalized with ammonium centers based on ethylenediamine (EDA), diethylenetriamine (DETA), triethylenetriamine (TETA) and tris-(2-aminoethyl)amine (TAEA) were investigated. The functionalized sorbent materials were characterized using SEM, XPS, BET, and FTIR. The sorbents were used in the batch and column study for adsorption and selective separation of [PtCl62− and PdCl4]2−. The adsorption model for both [PtCl6]2− and [PdCl4]2− on the different sorbent materials fitted the Freundlich isotherm with R2 values > 0.99. The S-TETA sorbent material was palladium(II) specific. Pd(II) loaded on the silica column was recovered using 3% m/v thiourea solution as the eluting agent. Separation of platinum and palladium was achieved by selective stripping of [PtCl6]2− with 0.5 M of NaClO4 in 1.0 M HCl while Pd(II) was eluted with 0.5 M thiourea in 1.0 M HCl. The separation of palladium (Pd) from a mixture containing platinum (Pt), iridium (Ir), and rhodium (Rh) was successful on silica functionalized with triethylenetriamine (TETA) showing specificity for palladium(II) and a loading capacity of 0.27 mg/g. S-TETA showed potential for use in the recovery of palladium from platinum group metals such as from solutions of worn out automobile emission control catalytic convertors and other secondary sources. , Original publication is available at http://dx.doi.org/10.1080/01496395.2014.978017
- Full Text: false
- Date Issued: 2015
- Authors: Fayemi, Omolola E , Ogunlaja, Adeniyi S , Antunes, Edith M , Nyokong, Tebello , Tshentu, Zenixole R
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:7270 , http://hdl.handle.net/10962/d1020285
- Description: The adsorption and separation of platinum(IV) and palladium(II) chlorido species ([PtCl6]2− and [PdCl4]2−) on silica-based microparticles functionalized with ammonium centers based on ethylenediamine (EDA), diethylenetriamine (DETA), triethylenetriamine (TETA) and tris-(2-aminoethyl)amine (TAEA) were investigated. The functionalized sorbent materials were characterized using SEM, XPS, BET, and FTIR. The sorbents were used in the batch and column study for adsorption and selective separation of [PtCl62− and PdCl4]2−. The adsorption model for both [PtCl6]2− and [PdCl4]2− on the different sorbent materials fitted the Freundlich isotherm with R2 values > 0.99. The S-TETA sorbent material was palladium(II) specific. Pd(II) loaded on the silica column was recovered using 3% m/v thiourea solution as the eluting agent. Separation of platinum and palladium was achieved by selective stripping of [PtCl6]2− with 0.5 M of NaClO4 in 1.0 M HCl while Pd(II) was eluted with 0.5 M thiourea in 1.0 M HCl. The separation of palladium (Pd) from a mixture containing platinum (Pt), iridium (Ir), and rhodium (Rh) was successful on silica functionalized with triethylenetriamine (TETA) showing specificity for palladium(II) and a loading capacity of 0.27 mg/g. S-TETA showed potential for use in the recovery of palladium from platinum group metals such as from solutions of worn out automobile emission control catalytic convertors and other secondary sources. , Original publication is available at http://dx.doi.org/10.1080/01496395.2014.978017
- Full Text: false
- Date Issued: 2015
The Development of Palladium(II)-Specific Amine-Functionalized Silica-Based Microparticles: Adsorption and Column Separation Studies
- Fayemi, Omolola E, Ogunlaja, Adeniyi S, Antunes, Edith M, Nyokong, Tebello, Tshentu, Zenixole R
- Authors: Fayemi, Omolola E , Ogunlaja, Adeniyi S , Antunes, Edith M , Nyokong, Tebello , Tshentu, Zenixole R
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:7269 , http://hdl.handle.net/10962/d1020278
- Description: The adsorption and separation of platinum(IV) and palladium(II) chlorido species ([PtCl6]2− and [PdCl4]2−) on silica-based microparticles functionalized with ammonium centers based on ethylenediamine (EDA), diethylenetriamine (DETA), triethylenetriamine (TETA) and tris-(2-aminoethyl)amine (TAEA) were investigated. The functionalized sorbent materials were characterized using SEM, XPS, BET, and FTIR. The sorbents were used in the batch and column study for adsorption and selective separation of [PtCl62− and PdCl4]2−. The adsorption model for both [PtCl6]2− and [PdCl4]2− on the different sorbent materials fitted the Freundlich isotherm with R2 values > 0.99. The S-TETA sorbent material was palladium(II) specific. Pd(II) loaded on the silica column was recovered using 3% m/v thiourea solution as the eluting agent. Separation of platinum and palladium was achieved by selective stripping of [PtCl6]2− with 0.5 M of NaClO4 in 1.0 M HCl while Pd(II) was eluted with 0.5 M thiourea in 1.0 M HCl. The separation of palladium (Pd) from a mixture containing platinum (Pt), iridium (Ir), and rhodium (Rh) was successful on silica functionalized with triethylenetriamine (TETA) showing specificity for palladium(II) and a loading capacity of 0.27 mg/g. S-TETA showed potential for use in the recovery of palladium from platinum group metals such as from solutions of worn out automobile emission control catalytic convertors and other secondary sources. , Original publication is available at http://dx.doi.org/10.1080/01496395.2014.978017
- Full Text: false
- Date Issued: 2015
- Authors: Fayemi, Omolola E , Ogunlaja, Adeniyi S , Antunes, Edith M , Nyokong, Tebello , Tshentu, Zenixole R
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:7269 , http://hdl.handle.net/10962/d1020278
- Description: The adsorption and separation of platinum(IV) and palladium(II) chlorido species ([PtCl6]2− and [PdCl4]2−) on silica-based microparticles functionalized with ammonium centers based on ethylenediamine (EDA), diethylenetriamine (DETA), triethylenetriamine (TETA) and tris-(2-aminoethyl)amine (TAEA) were investigated. The functionalized sorbent materials were characterized using SEM, XPS, BET, and FTIR. The sorbents were used in the batch and column study for adsorption and selective separation of [PtCl62− and PdCl4]2−. The adsorption model for both [PtCl6]2− and [PdCl4]2− on the different sorbent materials fitted the Freundlich isotherm with R2 values > 0.99. The S-TETA sorbent material was palladium(II) specific. Pd(II) loaded on the silica column was recovered using 3% m/v thiourea solution as the eluting agent. Separation of platinum and palladium was achieved by selective stripping of [PtCl6]2− with 0.5 M of NaClO4 in 1.0 M HCl while Pd(II) was eluted with 0.5 M thiourea in 1.0 M HCl. The separation of palladium (Pd) from a mixture containing platinum (Pt), iridium (Ir), and rhodium (Rh) was successful on silica functionalized with triethylenetriamine (TETA) showing specificity for palladium(II) and a loading capacity of 0.27 mg/g. S-TETA showed potential for use in the recovery of palladium from platinum group metals such as from solutions of worn out automobile emission control catalytic convertors and other secondary sources. , Original publication is available at http://dx.doi.org/10.1080/01496395.2014.978017
- Full Text: false
- Date Issued: 2015
The time of hospitality in Samuel Beckett's Murphy, Michael Ondaatje's The English Patient and Damon Galgut's The Good Doctor:
- Authors: Marais, Mike
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/144106 , vital:38312 , DOI: 10.1080/00138398.2015.1083193
- Description: In this article, I focus on the temporal dimension of the differential process through which community constitutes itself. If community is premised on the sameness that is enabled by that which it excludes, and sees as a threat, then it must seek always to conserve itself and to render the future – which is hazardous in its uncertainty – calculable, predictable and determinable. In its search for stability and permanence, community must dominate time in such a way that it is overcome, that it withdraws from itself. Arguably, though, we would view time less teleologically and programmatically, if we could relate differently to the difference on which community depends. A form of hospitality that is predicated on an acceptance of otherness – not only that of a community's outsiders, but also the ‘common strangeness’ of its insiders – would alter the ways in which being-in-common is conceived, and would also change our experience of belonging.
- Full Text:
- Date Issued: 2015
- Authors: Marais, Mike
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/144106 , vital:38312 , DOI: 10.1080/00138398.2015.1083193
- Description: In this article, I focus on the temporal dimension of the differential process through which community constitutes itself. If community is premised on the sameness that is enabled by that which it excludes, and sees as a threat, then it must seek always to conserve itself and to render the future – which is hazardous in its uncertainty – calculable, predictable and determinable. In its search for stability and permanence, community must dominate time in such a way that it is overcome, that it withdraws from itself. Arguably, though, we would view time less teleologically and programmatically, if we could relate differently to the difference on which community depends. A form of hospitality that is predicated on an acceptance of otherness – not only that of a community's outsiders, but also the ‘common strangeness’ of its insiders – would alter the ways in which being-in-common is conceived, and would also change our experience of belonging.
- Full Text:
- Date Issued: 2015
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