Earth stewardship in prepress:a model for Nelson Mandela Metropolitan University graphic design lectures
- Authors: Lottering,John Barry
- Date: 2017
- Subjects: Curriculum planning--South Africa-- Port Elizabeth Graphic arts--Study and teaching--South africa-- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/44471 , vital:37842
- Description: A lack of prepress understanding is responsible for a great deal of wasted resources in the graphic design and printing industries in Nelson Mandela Bay. As the term “prepress” extends to such a vast range of design activities, it is quite difficult to ascertain where prepress begins or ends. Asking the question “What is prepress?” is like asking “How long is a piece of string?” Defining the scope of prepress can present a formidable challenge for any graphic design lecturer hoping to equip students with the necessary prepress understanding and skills required by the graphic design industry. Also, even if the academic has a sound knowledge of prepress theory and practice, how does one guarantee that all of the required knowledge is covered during the course of the student’s graphic design education, and that it is done so in a manner that meets the needs of the graphic design industry? Added to this, educators have a responsibility to consider the environmental consequences of sending graduating designers, without industry required prepress knowledge, into the design industry, an industry that has grown accustomed to training junior designers in prepress practice through trial and error. Such trial and error equates to mistakes and wasted resources, as a result this learning curve comes at the expense of the environment. The intention of this research is to provide an accessible resource for graphic design lecturers, by way of a list of prepress best practice topics, required for inclusion in the graphic design syllabus at NMMU, such that earth stewardship and sustainable design-for-print are an implicit component. This list of topics is a product of research which drew on local industry experts in Nelson Mandela Bay.
- Full Text:
- Date Issued: 2017
- Authors: Lottering,John Barry
- Date: 2017
- Subjects: Curriculum planning--South Africa-- Port Elizabeth Graphic arts--Study and teaching--South africa-- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/44471 , vital:37842
- Description: A lack of prepress understanding is responsible for a great deal of wasted resources in the graphic design and printing industries in Nelson Mandela Bay. As the term “prepress” extends to such a vast range of design activities, it is quite difficult to ascertain where prepress begins or ends. Asking the question “What is prepress?” is like asking “How long is a piece of string?” Defining the scope of prepress can present a formidable challenge for any graphic design lecturer hoping to equip students with the necessary prepress understanding and skills required by the graphic design industry. Also, even if the academic has a sound knowledge of prepress theory and practice, how does one guarantee that all of the required knowledge is covered during the course of the student’s graphic design education, and that it is done so in a manner that meets the needs of the graphic design industry? Added to this, educators have a responsibility to consider the environmental consequences of sending graduating designers, without industry required prepress knowledge, into the design industry, an industry that has grown accustomed to training junior designers in prepress practice through trial and error. Such trial and error equates to mistakes and wasted resources, as a result this learning curve comes at the expense of the environment. The intention of this research is to provide an accessible resource for graphic design lecturers, by way of a list of prepress best practice topics, required for inclusion in the graphic design syllabus at NMMU, such that earth stewardship and sustainable design-for-print are an implicit component. This list of topics is a product of research which drew on local industry experts in Nelson Mandela Bay.
- Full Text:
- Date Issued: 2017
Eco-tourism and sustainable rural livelihoods in Hogsback, Eastern Cape, South Africa
- Authors: Pikirai, Kelvin Tinashe
- Date: 2017
- Subjects: Ecotourism -- Economic aspects -- South Africa -- Eastern Cape Community development -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSoc
- Identifier: http://hdl.handle.net/10353/5510 , vital:29298
- Description: This study investigates the livelihoods impacts of eco-tourism in Hogsback, the extent to which local community members are effectively participating in eco-tourism activities as well as the negative implications of ecotourism in Hogsback. A qualitative research methodology was employed in order to have a deeper understanding of the issues under study. Simple random sampling and purposive sampling techniques were used to select respondents. In-depth semi structured interviews were used to collect data from 40 respondents and 6 key informants. The study established that eco-tourism activities help mainly individuals rather than the whole community at large and those who benefit; it improves their lives as well as benefiting the economy of the country. This study also found out that the government plays a role to promote development of ecotourism in the community, this is through infrastructure development and providing services for tourism. Lastly the study found out that there are conflicts over ownership of eco-tourism activities, limited funds in promotion of eco-tourism activities and that there is no eco-tourism development strategy. The study recommends that the government of South Africa should design and implement a comprehensive eco-tourism development strategy that puts people at the core.
- Full Text:
- Date Issued: 2017
- Authors: Pikirai, Kelvin Tinashe
- Date: 2017
- Subjects: Ecotourism -- Economic aspects -- South Africa -- Eastern Cape Community development -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSoc
- Identifier: http://hdl.handle.net/10353/5510 , vital:29298
- Description: This study investigates the livelihoods impacts of eco-tourism in Hogsback, the extent to which local community members are effectively participating in eco-tourism activities as well as the negative implications of ecotourism in Hogsback. A qualitative research methodology was employed in order to have a deeper understanding of the issues under study. Simple random sampling and purposive sampling techniques were used to select respondents. In-depth semi structured interviews were used to collect data from 40 respondents and 6 key informants. The study established that eco-tourism activities help mainly individuals rather than the whole community at large and those who benefit; it improves their lives as well as benefiting the economy of the country. This study also found out that the government plays a role to promote development of ecotourism in the community, this is through infrastructure development and providing services for tourism. Lastly the study found out that there are conflicts over ownership of eco-tourism activities, limited funds in promotion of eco-tourism activities and that there is no eco-tourism development strategy. The study recommends that the government of South Africa should design and implement a comprehensive eco-tourism development strategy that puts people at the core.
- Full Text:
- Date Issued: 2017
Ecological dominance along rocky shores, with a focus on intertidal ascidians
- Rius, Marc, Teske, Peter R, Manriquez, Patricio H, Suarez-Jimenez, Rocio, McQuaid, Christopher D
- Authors: Rius, Marc , Teske, Peter R , Manriquez, Patricio H , Suarez-Jimenez, Rocio , McQuaid, Christopher D
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/453416 , vital:75252 , ISBN 9781138197862 , https://www.taylorfrancis.com/chapters/oa-edit/10.1201/b21944-4/ecological-dominance-along-rocky-shores-focus-intertidal-ascidians-marc-rius-peter-teske-patricio-manr%C3%ADquez-roc%C3%ADo-su%C3%A1rez-jim%C3%A9nez-christopher-mcquaid-juan-carlos-castilla?context=ubxandrefId=e4c0e0f7-2c0a-417f-8751-8225febf1536
- Description: The role of dominant species is of central importance in ecology. Such species play a key role in ecosystem structure, stability and function, regulating resource allocation across trophic levels and overall ecosystem productivity. Although ecological interactions between dominant and subordinate species are often considered to influence the latter negatively, the presence of dominant species can also be beneficial. These species commonly act as ecosystem engineers and enhance biodiversity by creating habitat for other species. Along rocky coastlines, dominant species are often sessile suspension-feeding organisms that can monopolize all available substrata. This is particularly noticeable in intertidal and shallow subtidal habitats where the number of species that achieve ecological dominance is limited. Here, we review the ecological and evolutionary mechanisms that facilitate dominance along rocky coastlines. We then focus on a prominent example, the members of the Pyura stolonifera species complex (Tunicata), which are an emerging model system for studying ecological dominance. These ascidians achieve the highest biomass levels ever reported in rocky intertidal habitats and, when invasive, can fundamentally transform entire ecosystems. Finally, we discuss conservation implications and conclude with directions for future research.
- Full Text:
- Date Issued: 2017
- Authors: Rius, Marc , Teske, Peter R , Manriquez, Patricio H , Suarez-Jimenez, Rocio , McQuaid, Christopher D
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/453416 , vital:75252 , ISBN 9781138197862 , https://www.taylorfrancis.com/chapters/oa-edit/10.1201/b21944-4/ecological-dominance-along-rocky-shores-focus-intertidal-ascidians-marc-rius-peter-teske-patricio-manr%C3%ADquez-roc%C3%ADo-su%C3%A1rez-jim%C3%A9nez-christopher-mcquaid-juan-carlos-castilla?context=ubxandrefId=e4c0e0f7-2c0a-417f-8751-8225febf1536
- Description: The role of dominant species is of central importance in ecology. Such species play a key role in ecosystem structure, stability and function, regulating resource allocation across trophic levels and overall ecosystem productivity. Although ecological interactions between dominant and subordinate species are often considered to influence the latter negatively, the presence of dominant species can also be beneficial. These species commonly act as ecosystem engineers and enhance biodiversity by creating habitat for other species. Along rocky coastlines, dominant species are often sessile suspension-feeding organisms that can monopolize all available substrata. This is particularly noticeable in intertidal and shallow subtidal habitats where the number of species that achieve ecological dominance is limited. Here, we review the ecological and evolutionary mechanisms that facilitate dominance along rocky coastlines. We then focus on a prominent example, the members of the Pyura stolonifera species complex (Tunicata), which are an emerging model system for studying ecological dominance. These ascidians achieve the highest biomass levels ever reported in rocky intertidal habitats and, when invasive, can fundamentally transform entire ecosystems. Finally, we discuss conservation implications and conclude with directions for future research.
- Full Text:
- Date Issued: 2017
Ecology of key cerithioidean gastropods in the mangroves of the iSimangaliso Wetland Park, KwaZulu-Natal South Africa
- Authors: Raw, Jacqueline Leoni
- Date: 2017
- Subjects: Gastropoda -- South Africa -- KwaZulu-Natal Mangrove ecology -- South Africa -- KwaZulu-Natal
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/11942 , vital:27009
- Description: Gastropods are one of the most diverse species groups in mangrove habitats, however, many of their specific roles in relation to ecological patterns and processes are currently largely unknown. The overall aim of this research project was to provide basic ecological information for key gastropod species from subtropical mangroves within a protected area. South African mangroves cover relatively small areas and are restricted to estuaries, these habitats therefore present unique opportunities and challenges to the species that occur in them. Three gastropod species, Terebralia palustris, Cerithidea decollata, and Melanoides tuberculata, all occur at their natural southernmost range limit within South Africa and were selected based on their prominence and occurrence in mangrove habitats of the iSimangaliso Wetland Park, a UNESCO World Heritage Site. Trophic linkages and resource partitioning, resource utilization rates, and ecological resilience were investigated respectively using: 1) a stable isotope (δ15N and δ13C) approach; 2) an experimental approach to quantify feeding dynamics (ingestion rate, consumption/digestion efficiency and grazing impact); and 3) a mixed-effects modelling approach to relate population responses to environmental variables. The diet of T. palustris was seasonally variable and a number of sources were incorporated by different sized snails, but their grazing impact on microphytobenthos was not significant. The results also indicated an ontogenetic shift in the dietary niche for T. palustris through robust partitioning of resources between different size classes. The diets of C. decollata and M. tuberculata were dominated by different primary resources as a function of where they occurred in the mangroves. Melanoides tuberculata consumed a wide variety of primary resources, a typical trait of an opportunistic generalist species. The ingestion rate of M. tuberculata was not dependent on the availability of microphytobenthos, and was highest when conditions were oligotrophic. The resilience of C. decollata was related to the tree-climbing behaviour of this species and its occurrence was best explained by sediment conductivity. These responses were considered in conjunction to what has previously been reported on the resilience of the mangrove trees. The results of this research project have provided new basic ecological information for all three gastropod species in this data-deficient subtropical region. This information can potentially be used in comparative studies for these species in other regions or in broader scale ecological studies. Terebralia palustris has recently experienced a range contraction along the South African coastline. This research project has shown that the diet of this species is highly variable and that food limitation and competition for resources should be considered as potential drivers of the local decline. Cerithidea decollata has in contrast expanded its distributional range in this region. This research project has shown that this species has a generalist diet and exhibits traits in relation to tolerance that are expected to have facilitated its expansion into temperate saltmarsh habitats that occur in dynamic estuaries. Melanoides tuberculata is a globally invasive species, and as South African populations are within its native range, ecological information from this region is valuable as it can be used to investigate the potential ecological effects following introduction into new habitats beyond the native range. Biological drivers have a significant impact on mangrove ecosystem functioning, particularly in relation to recycling and the retention of organic carbon generated through primary productivity. Understanding the ecological linkages that maintain ecological functioning and stability is therefore an important step towards conserving and sustainably managing threatened ecosystems such as mangrove forests.
- Full Text:
- Date Issued: 2017
- Authors: Raw, Jacqueline Leoni
- Date: 2017
- Subjects: Gastropoda -- South Africa -- KwaZulu-Natal Mangrove ecology -- South Africa -- KwaZulu-Natal
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/11942 , vital:27009
- Description: Gastropods are one of the most diverse species groups in mangrove habitats, however, many of their specific roles in relation to ecological patterns and processes are currently largely unknown. The overall aim of this research project was to provide basic ecological information for key gastropod species from subtropical mangroves within a protected area. South African mangroves cover relatively small areas and are restricted to estuaries, these habitats therefore present unique opportunities and challenges to the species that occur in them. Three gastropod species, Terebralia palustris, Cerithidea decollata, and Melanoides tuberculata, all occur at their natural southernmost range limit within South Africa and were selected based on their prominence and occurrence in mangrove habitats of the iSimangaliso Wetland Park, a UNESCO World Heritage Site. Trophic linkages and resource partitioning, resource utilization rates, and ecological resilience were investigated respectively using: 1) a stable isotope (δ15N and δ13C) approach; 2) an experimental approach to quantify feeding dynamics (ingestion rate, consumption/digestion efficiency and grazing impact); and 3) a mixed-effects modelling approach to relate population responses to environmental variables. The diet of T. palustris was seasonally variable and a number of sources were incorporated by different sized snails, but their grazing impact on microphytobenthos was not significant. The results also indicated an ontogenetic shift in the dietary niche for T. palustris through robust partitioning of resources between different size classes. The diets of C. decollata and M. tuberculata were dominated by different primary resources as a function of where they occurred in the mangroves. Melanoides tuberculata consumed a wide variety of primary resources, a typical trait of an opportunistic generalist species. The ingestion rate of M. tuberculata was not dependent on the availability of microphytobenthos, and was highest when conditions were oligotrophic. The resilience of C. decollata was related to the tree-climbing behaviour of this species and its occurrence was best explained by sediment conductivity. These responses were considered in conjunction to what has previously been reported on the resilience of the mangrove trees. The results of this research project have provided new basic ecological information for all three gastropod species in this data-deficient subtropical region. This information can potentially be used in comparative studies for these species in other regions or in broader scale ecological studies. Terebralia palustris has recently experienced a range contraction along the South African coastline. This research project has shown that the diet of this species is highly variable and that food limitation and competition for resources should be considered as potential drivers of the local decline. Cerithidea decollata has in contrast expanded its distributional range in this region. This research project has shown that this species has a generalist diet and exhibits traits in relation to tolerance that are expected to have facilitated its expansion into temperate saltmarsh habitats that occur in dynamic estuaries. Melanoides tuberculata is a globally invasive species, and as South African populations are within its native range, ecological information from this region is valuable as it can be used to investigate the potential ecological effects following introduction into new habitats beyond the native range. Biological drivers have a significant impact on mangrove ecosystem functioning, particularly in relation to recycling and the retention of organic carbon generated through primary productivity. Understanding the ecological linkages that maintain ecological functioning and stability is therefore an important step towards conserving and sustainably managing threatened ecosystems such as mangrove forests.
- Full Text:
- Date Issued: 2017
Economic development in the Eastern Cape: a case study of agricultural projects
- Authors: Dyalo, Nolutho
- Date: 2017
- Subjects: Agricultural development projects -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MPhil
- Identifier: http://hdl.handle.net/10948/15589 , vital:28274
- Description: This study seeks to evaluate economic development in the Eastern Cape Province, with a special focus on the agricultural sector. It focuses on the role that Development Finance Institutions (DFIs) play in stimulating economic development. To achieve this, the Eastern Cape Development Corporation (ECDC) was considered as a case study in assessing DFI’s support to the agricultural sector in the province. The study will also look into the corporation’s adherence to the Provincial Growth and Development Plan (PGDP) and its strategic programmes. The study examines how the agricultural initiatives financed by ECDC contribute to economic development in the province. It will also assess whether those agricultural projects may impact the local communities through poverty alleviation. In order to address the research problem and to achieve the research objectives, available literature and empirical work related to the relationship between financial system development and economic development was reviewed. The research revealed that the role played by the ECDC with regard to Agricultural Projects has not been entirely effective to add value to economic development in the province, mainly caused by the lack of non – financial support by skilled people from the corporation, after limited funding was made available. From the investigation, the findings indicate that the effective mplementation of these projects require strengthened capacity, which requires more skilled officials from the corporation to assist the agricultural enterprises in managing the projects; and more funding that will assist the projects to reach sustainability.
- Full Text:
- Date Issued: 2017
- Authors: Dyalo, Nolutho
- Date: 2017
- Subjects: Agricultural development projects -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MPhil
- Identifier: http://hdl.handle.net/10948/15589 , vital:28274
- Description: This study seeks to evaluate economic development in the Eastern Cape Province, with a special focus on the agricultural sector. It focuses on the role that Development Finance Institutions (DFIs) play in stimulating economic development. To achieve this, the Eastern Cape Development Corporation (ECDC) was considered as a case study in assessing DFI’s support to the agricultural sector in the province. The study will also look into the corporation’s adherence to the Provincial Growth and Development Plan (PGDP) and its strategic programmes. The study examines how the agricultural initiatives financed by ECDC contribute to economic development in the province. It will also assess whether those agricultural projects may impact the local communities through poverty alleviation. In order to address the research problem and to achieve the research objectives, available literature and empirical work related to the relationship between financial system development and economic development was reviewed. The research revealed that the role played by the ECDC with regard to Agricultural Projects has not been entirely effective to add value to economic development in the province, mainly caused by the lack of non – financial support by skilled people from the corporation, after limited funding was made available. From the investigation, the findings indicate that the effective mplementation of these projects require strengthened capacity, which requires more skilled officials from the corporation to assist the agricultural enterprises in managing the projects; and more funding that will assist the projects to reach sustainability.
- Full Text:
- Date Issued: 2017
Ecophysiology and nutrient uptake mechanisms facilitating the prolonged bloom persistence by Cyanothece sp. in Lake St Lucia, South Africa
- Authors: Du Plooy, Schalk Jacobus
- Date: 2017
- Subjects: Cyanobacterial blooms , Cyanobacteria -- Physiology , Cyanobacteria
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/7344 , vital:21324
- Description: Cyanobacterial blooms are becoming more frequent worldwide, with possible negative effects on human health. The effects of climate change and eutrophication have been associated with persistent cyanobacterial blooms becoming more frequent. Altered water characteristics, salinity in particular, influence ecosystem dynamics that may lead to conditions conducive to cyanobacterial blooms. The occurrence of an 18-month long Cyanothece sp. bloom (the longest for any cyanobacterium recorded so far worldwide and the first of the genus) from June 2009 to December 2010 in Africa’s largest estuarine lake, St Lucia, highlighted the susceptibility of ecosystems to anthropogenic alterations. This study investigated the long-term survival and physiological adaptations of Cyanothece sp. to various and dynamic environmental conditions that contributed towards its bloom persistence. The main findings are the high salinities at which Cyanothece sp. could perform important physiological processes such as N uptake, N2 fixation and photosynthesis. Nutrient uptake (both nitrogen and phosphorus) was observed over the full experimental salinity range (0-300) while N2 fixation was only observed up to a salinity of 120. Nutrient uptake rates significantly decreased at this threshold salinity of 120. Interestingly, photosystem II activity was not observed in Cyanothece sp. during this study, but photosystem I activity was robust. Salinity had a minor influence on electron transport rates by photosystem I, high temperature (> 30°C) did however increase electron transport rates. Rapid responses to hypo-osmotic shock (i.e. osmotic downshift during freshening events) by Cyanothece sp. cells also helped minimize cell rupture due to high turgor pressure. Zooplankton abundance within the St Lucia system was negatively correlated with salinity, while grazing experiments indicated that the typical estuarine zooplankton species are able to graze on Cyanothece sp. cells. Therefore, the disappearance of zooplankton at salinities above 60 must have been an important factor in the bloom persistence. Apart from the ecological factors that were at play in St Lucia during the bloom period, the persistence of the Cyanothece sp. bloom can be attributed to the robust nature of their nutrient uptake, nitrogen fixation and photosynthetic systems to maintain activity despite extreme hypersalinity levels.
- Full Text:
- Date Issued: 2017
- Authors: Du Plooy, Schalk Jacobus
- Date: 2017
- Subjects: Cyanobacterial blooms , Cyanobacteria -- Physiology , Cyanobacteria
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/7344 , vital:21324
- Description: Cyanobacterial blooms are becoming more frequent worldwide, with possible negative effects on human health. The effects of climate change and eutrophication have been associated with persistent cyanobacterial blooms becoming more frequent. Altered water characteristics, salinity in particular, influence ecosystem dynamics that may lead to conditions conducive to cyanobacterial blooms. The occurrence of an 18-month long Cyanothece sp. bloom (the longest for any cyanobacterium recorded so far worldwide and the first of the genus) from June 2009 to December 2010 in Africa’s largest estuarine lake, St Lucia, highlighted the susceptibility of ecosystems to anthropogenic alterations. This study investigated the long-term survival and physiological adaptations of Cyanothece sp. to various and dynamic environmental conditions that contributed towards its bloom persistence. The main findings are the high salinities at which Cyanothece sp. could perform important physiological processes such as N uptake, N2 fixation and photosynthesis. Nutrient uptake (both nitrogen and phosphorus) was observed over the full experimental salinity range (0-300) while N2 fixation was only observed up to a salinity of 120. Nutrient uptake rates significantly decreased at this threshold salinity of 120. Interestingly, photosystem II activity was not observed in Cyanothece sp. during this study, but photosystem I activity was robust. Salinity had a minor influence on electron transport rates by photosystem I, high temperature (> 30°C) did however increase electron transport rates. Rapid responses to hypo-osmotic shock (i.e. osmotic downshift during freshening events) by Cyanothece sp. cells also helped minimize cell rupture due to high turgor pressure. Zooplankton abundance within the St Lucia system was negatively correlated with salinity, while grazing experiments indicated that the typical estuarine zooplankton species are able to graze on Cyanothece sp. cells. Therefore, the disappearance of zooplankton at salinities above 60 must have been an important factor in the bloom persistence. Apart from the ecological factors that were at play in St Lucia during the bloom period, the persistence of the Cyanothece sp. bloom can be attributed to the robust nature of their nutrient uptake, nitrogen fixation and photosynthetic systems to maintain activity despite extreme hypersalinity levels.
- Full Text:
- Date Issued: 2017
Ecosystem engineering by the wetland plant palmiet: does it control fluvial form and promote diffuse flow in steep-sided valleys of the Cape Fold Mountains
- Authors: Barclay, Amy
- Date: 2017
- Subjects: Prionium serratum , Wetlands -- South Africa -- Eastern Cape , Aquatic plants -- South Africa -- Eastern Cape , Peatland ecology -- South Africa -- Eastern Cape , Kromme River (Eastern Cape, South Africa)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/4646 , vital:20708
- Description: Ecosystem engineering refers to the way that organisms control the structure and function of ecosystems. It has been suggested that palmiet (Prionium serratum, Thurniaceae) works as an ecosystem engineer, shaping peat wetlands in South Africa. However, there is currently a paucity of evidence supporting this claim. Palmiet has a dense root, rhizome and stem system that forms dense stands, growing from channel banks into fast flowing river channels. This slows river flows, traps sediment, which builds up riverbeds and ultimately blocks river channels, turning the river into a wetland. The aim of this study was to determine if palmiet is an ecosystem engineer and to document its pattern of colonisation and the nature of its control of a fluvial system. This was achieved by undertaking vegetation surveys in the Kromrivier Wetland in the Eastern Cape. The data was analyzed using vegetation classification and ordination, where vegetation communities were linked to environmental factors. It was found that palmiet occupied three distinctive habitats; 1) on near-horizontal valley- bottom habitats filled with sediments that are a mixture of autochthonous organic sediment and allochthonous clastic fines, 2) the bed of gullies that have recently filled with coarse grained clastic sediment, and 3) open water bodies. Three conceptual models were developed, one that accounts for the process of gully bed colonisation, sediment trapping and gully filling, another involving rapid colonisation of sedimentary fill from tributary sediment sources that block a gully, and the third involving colonisation of open-water areas that form in former gullies upstream of the blockage. The study suggests that the wetland has been characterised by repeated cutting and filling cycles, despite which, palmiet has repeatedly reinstated diffuse flow conditions across the valley floor. Palmiet was indicated to exert a key control on fluvial form and dynamics of the wetlands in the Kromrivier valley.
- Full Text:
- Date Issued: 2017
- Authors: Barclay, Amy
- Date: 2017
- Subjects: Prionium serratum , Wetlands -- South Africa -- Eastern Cape , Aquatic plants -- South Africa -- Eastern Cape , Peatland ecology -- South Africa -- Eastern Cape , Kromme River (Eastern Cape, South Africa)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/4646 , vital:20708
- Description: Ecosystem engineering refers to the way that organisms control the structure and function of ecosystems. It has been suggested that palmiet (Prionium serratum, Thurniaceae) works as an ecosystem engineer, shaping peat wetlands in South Africa. However, there is currently a paucity of evidence supporting this claim. Palmiet has a dense root, rhizome and stem system that forms dense stands, growing from channel banks into fast flowing river channels. This slows river flows, traps sediment, which builds up riverbeds and ultimately blocks river channels, turning the river into a wetland. The aim of this study was to determine if palmiet is an ecosystem engineer and to document its pattern of colonisation and the nature of its control of a fluvial system. This was achieved by undertaking vegetation surveys in the Kromrivier Wetland in the Eastern Cape. The data was analyzed using vegetation classification and ordination, where vegetation communities were linked to environmental factors. It was found that palmiet occupied three distinctive habitats; 1) on near-horizontal valley- bottom habitats filled with sediments that are a mixture of autochthonous organic sediment and allochthonous clastic fines, 2) the bed of gullies that have recently filled with coarse grained clastic sediment, and 3) open water bodies. Three conceptual models were developed, one that accounts for the process of gully bed colonisation, sediment trapping and gully filling, another involving rapid colonisation of sedimentary fill from tributary sediment sources that block a gully, and the third involving colonisation of open-water areas that form in former gullies upstream of the blockage. The study suggests that the wetland has been characterised by repeated cutting and filling cycles, despite which, palmiet has repeatedly reinstated diffuse flow conditions across the valley floor. Palmiet was indicated to exert a key control on fluvial form and dynamics of the wetlands in the Kromrivier valley.
- Full Text:
- Date Issued: 2017
Ecosystem services in a biosphere reserve context: identification, mapping and valuation
- Authors: Ntshane, Basane Claire
- Date: 2017
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/4536 , vital:20686
- Description: Despite their contribution to human well-being, ecosystem services (ES) are being destroyed by anthropogenic activities, taken for granted and often compromised during land use decision making. The question that often arises is, what value do ES have compared to other undertakings that are economically robust, such as mining? The vision of the Millenium Ecosystem Assessment (MA) was a world in which natural assets (including ES) are appreciated and integrated into decision-making. The biodiversity strategy of the Convention on Biological Diversity (CBD) also concerns the integration of natural assets into decision making. Responding to challenges facing ES and their mainstreaming into decision-making has been constrained by lack of data and requires new tools and approaches. Integrating natural assets into decision-making is very important for South Africa (SA), where ES have been a crucial part of human systems for decades, and also because of the country’s commitment to the implementation of the CBD's biodiversity strategy. With the aim of incorporating ES into decision-making in an integrated way, this study was conducted in two biosphere reserves (BRs), Vhembe and Waterberg, in Limpopo Province, SA. The aims of the study were the identification, mapping and valuation of ES following an integrated approach. In order to achieve these aims, the study attempted to address four key objectives: (1) to assess and evaluate the status of mapping and valuation of ES in SA, (2) to identify and quantify ES and their indicators, (3) to investigate and analyse the impact of land use/cover (LU/LC) change to ES and (4) to conduct valuation of selected ES. Two separate literature reviews were undertaken to assess and evaluate the status of mapping and valuation of ES in SA, thus addressing study objective 1. Both reviews detected a significant research gap with regard to mapping and valuation of supporting services in SA. To identify ES and indicators provided by the two BRs and to assess the impact of LU/LC change and its effect on ES, a participatory scenario planning process was conducted under three different scenarios, namely ecological development, social development and economic development. It became clear that LU issues were diverse in nature and affected ES in a number of ways and that there were always trade-offs in the choice of LU. For example, yields of ES were best in the ecological development scenario and were affected negatively, together with agricultural commodity production, in the social development and economic development scenarios. A mapping exercise was undertaken to illustrate the spatial distribution of ES supply and demand, involving five ES and 15 indicators using existing datasets and the Integrated Valuation of Ecosystem Services and Trade-offs (InVEST) mapping tool, again addressing objective 2 of the study. Carbon storage and habitat quality were assessed, modelled and quantified and their values provided in biophysical terms using InVEST modelling tools, thus addressing objective 4 of the study. High quantities of carbon storage and high habitat quality were recorded in natural areas and low quantities were recorded in managed systems (cultivated, urban and plantation areas). InVEST was again applied to conduct an economic valuation of two provisioning ES, timber and firewood, by determining their net present values, attempting to address objective 4 of the study. Results revealed that, at 12% discount rate, the net present value (NPV) for timber production accounted for R23 317/ha in VBR and R57 304/ha in WBR. However, at lower discount rates (4 and 7%), the NPVs for timber were negative in VBR and positive in WBR. With regard to firewood production, the NPVs were negative against all three discount rates in both study areas. I conclude by proposing a four-step integrated approach that can aid the successful incorporation of ES into decision-making: (1) maintain a balance between the social, economic and ecological aspects when making decisions on ES, (2) strive for an evidence- based approach to decision-making (use quantities and values), (3) apply integrated approaches (methods and techniques) to quantification and valuation, and (4) communicate all steps along the way. The results of this study will serve as a baseline for integration of ES into decision-making in SA.
- Full Text:
- Date Issued: 2017
- Authors: Ntshane, Basane Claire
- Date: 2017
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/4536 , vital:20686
- Description: Despite their contribution to human well-being, ecosystem services (ES) are being destroyed by anthropogenic activities, taken for granted and often compromised during land use decision making. The question that often arises is, what value do ES have compared to other undertakings that are economically robust, such as mining? The vision of the Millenium Ecosystem Assessment (MA) was a world in which natural assets (including ES) are appreciated and integrated into decision-making. The biodiversity strategy of the Convention on Biological Diversity (CBD) also concerns the integration of natural assets into decision making. Responding to challenges facing ES and their mainstreaming into decision-making has been constrained by lack of data and requires new tools and approaches. Integrating natural assets into decision-making is very important for South Africa (SA), where ES have been a crucial part of human systems for decades, and also because of the country’s commitment to the implementation of the CBD's biodiversity strategy. With the aim of incorporating ES into decision-making in an integrated way, this study was conducted in two biosphere reserves (BRs), Vhembe and Waterberg, in Limpopo Province, SA. The aims of the study were the identification, mapping and valuation of ES following an integrated approach. In order to achieve these aims, the study attempted to address four key objectives: (1) to assess and evaluate the status of mapping and valuation of ES in SA, (2) to identify and quantify ES and their indicators, (3) to investigate and analyse the impact of land use/cover (LU/LC) change to ES and (4) to conduct valuation of selected ES. Two separate literature reviews were undertaken to assess and evaluate the status of mapping and valuation of ES in SA, thus addressing study objective 1. Both reviews detected a significant research gap with regard to mapping and valuation of supporting services in SA. To identify ES and indicators provided by the two BRs and to assess the impact of LU/LC change and its effect on ES, a participatory scenario planning process was conducted under three different scenarios, namely ecological development, social development and economic development. It became clear that LU issues were diverse in nature and affected ES in a number of ways and that there were always trade-offs in the choice of LU. For example, yields of ES were best in the ecological development scenario and were affected negatively, together with agricultural commodity production, in the social development and economic development scenarios. A mapping exercise was undertaken to illustrate the spatial distribution of ES supply and demand, involving five ES and 15 indicators using existing datasets and the Integrated Valuation of Ecosystem Services and Trade-offs (InVEST) mapping tool, again addressing objective 2 of the study. Carbon storage and habitat quality were assessed, modelled and quantified and their values provided in biophysical terms using InVEST modelling tools, thus addressing objective 4 of the study. High quantities of carbon storage and high habitat quality were recorded in natural areas and low quantities were recorded in managed systems (cultivated, urban and plantation areas). InVEST was again applied to conduct an economic valuation of two provisioning ES, timber and firewood, by determining their net present values, attempting to address objective 4 of the study. Results revealed that, at 12% discount rate, the net present value (NPV) for timber production accounted for R23 317/ha in VBR and R57 304/ha in WBR. However, at lower discount rates (4 and 7%), the NPVs for timber were negative in VBR and positive in WBR. With regard to firewood production, the NPVs were negative against all three discount rates in both study areas. I conclude by proposing a four-step integrated approach that can aid the successful incorporation of ES into decision-making: (1) maintain a balance between the social, economic and ecological aspects when making decisions on ES, (2) strive for an evidence- based approach to decision-making (use quantities and values), (3) apply integrated approaches (methods and techniques) to quantification and valuation, and (4) communicate all steps along the way. The results of this study will serve as a baseline for integration of ES into decision-making in SA.
- Full Text:
- Date Issued: 2017
Ecosystem-scale impacts of non-timber forest product harvesting: Effects on soil nutrients
- Ruwanza, Sheunesu, Shackleton, Charlie M
- Authors: Ruwanza, Sheunesu , Shackleton, Charlie M
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/180099 , vital:43309 , xlink:href="https://doi.org/10.1111/1365-2664.12891"
- Description: The harvesting of non-timber forest products (NTFPs) is a global phenomenon, the sustainability of which has been studied for many species at the individual and population level. However, the broader scale impacts of NTFP harvesting have been acknowledged but rarely examined. We assessed plant size and the soil attributes undercanopy and in the open, in replicate, paired harvested and non-harvested sites for three NTFPs differing in the extent of biomass removed, i.e. timber for firewood from a tree (Acacia karroo), fruits from a cactus (Opunita ficus-indica) and flowering culms from a grass (Cymbopogon marginatus). Soil variables tested included pH, resistivity, P, total N, nitrate nitrogen, ammonium nitrogen, K, Na, Ca and Mg. The extent of loss of soil nutrients decreased across the three NTFPs relative to the proportion of biomass removed. Thus, significant differences in more soil variables were evident for the firewood species, least for the fruit species and intermediate for the grass species. Lower soil pH, P, C and K were evident in soils collected underneath A. karroo, while losses in cations of Na, Ca and Mg were reported in soils underneath C. marginatus, and only NO3N losses were recorded underneath O. ficus-indica. Our study reveals that while non-timber forest product (NTFP) harvesting may affect soil nutrients, this is not uniform between species and is likely to be a function of the extent of biomass removed and harvesting frequency. This indicates the need for caution in generalisations about the ecosystem-level impacts of NTFP harvesting as well as a concerted effort to better understand impacts at a greater range of scales than has been the case to date.
- Full Text:
- Date Issued: 2017
- Authors: Ruwanza, Sheunesu , Shackleton, Charlie M
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/180099 , vital:43309 , xlink:href="https://doi.org/10.1111/1365-2664.12891"
- Description: The harvesting of non-timber forest products (NTFPs) is a global phenomenon, the sustainability of which has been studied for many species at the individual and population level. However, the broader scale impacts of NTFP harvesting have been acknowledged but rarely examined. We assessed plant size and the soil attributes undercanopy and in the open, in replicate, paired harvested and non-harvested sites for three NTFPs differing in the extent of biomass removed, i.e. timber for firewood from a tree (Acacia karroo), fruits from a cactus (Opunita ficus-indica) and flowering culms from a grass (Cymbopogon marginatus). Soil variables tested included pH, resistivity, P, total N, nitrate nitrogen, ammonium nitrogen, K, Na, Ca and Mg. The extent of loss of soil nutrients decreased across the three NTFPs relative to the proportion of biomass removed. Thus, significant differences in more soil variables were evident for the firewood species, least for the fruit species and intermediate for the grass species. Lower soil pH, P, C and K were evident in soils collected underneath A. karroo, while losses in cations of Na, Ca and Mg were reported in soils underneath C. marginatus, and only NO3N losses were recorded underneath O. ficus-indica. Our study reveals that while non-timber forest product (NTFP) harvesting may affect soil nutrients, this is not uniform between species and is likely to be a function of the extent of biomass removed and harvesting frequency. This indicates the need for caution in generalisations about the ecosystem-level impacts of NTFP harvesting as well as a concerted effort to better understand impacts at a greater range of scales than has been the case to date.
- Full Text:
- Date Issued: 2017
Education and the common good
- Authors: Lotz-Sisitka, Heila
- Date: 2017
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/126060 , vital:35846 , ISBN 9783319513225 , https://link.springer.com/chapter/10.1007/978-3-319-51322-5_5?utm_source=twitter&utm_medium=social&utm_content=ads&utm_campaign=SRHS_2_VB_Edu-Series-FTA-Nine#citeas , https://doi.org/10.1007/978-3-319-51322-5_5
- Description: The chapter responds to a recent invitation by the UNESCO to respond to the contents of their book on the purpose of education, entitled Rethinking Education: Towards a Global Common Good? I explore the concept of the common good (as it relates to concepts of commons and commoning activity) and what it might mean to engage with commoning as an educational activity, if the commons, as argued by Amin and Howell, is to be “released” from historical descriptions of commons and commoning activity, to embrace a futures orientation. Drawing on critical realism and decolonization theory, as well as experience of working with expansive social learning, I propose that an educational theory grounded in a concept of emergence is needed in such a context.
- Full Text: false
- Date Issued: 2017
- Authors: Lotz-Sisitka, Heila
- Date: 2017
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/126060 , vital:35846 , ISBN 9783319513225 , https://link.springer.com/chapter/10.1007/978-3-319-51322-5_5?utm_source=twitter&utm_medium=social&utm_content=ads&utm_campaign=SRHS_2_VB_Edu-Series-FTA-Nine#citeas , https://doi.org/10.1007/978-3-319-51322-5_5
- Description: The chapter responds to a recent invitation by the UNESCO to respond to the contents of their book on the purpose of education, entitled Rethinking Education: Towards a Global Common Good? I explore the concept of the common good (as it relates to concepts of commons and commoning activity) and what it might mean to engage with commoning as an educational activity, if the commons, as argued by Amin and Howell, is to be “released” from historical descriptions of commons and commoning activity, to embrace a futures orientation. Drawing on critical realism and decolonization theory, as well as experience of working with expansive social learning, I propose that an educational theory grounded in a concept of emergence is needed in such a context.
- Full Text: false
- Date Issued: 2017
Education for sustainable development in the Namibian Biology curriculum
- Authors: Tshiningayamwe, Sirrka
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/436223 , vital:73250 , ISBN 978-3-319-45989-9 , https://doi.org/10.1007/978-3-319-45989-9_8
- Description: As a response to the United Nations Decade of Education for Sustainable Development, Namibia has incorporated Educa-tion for Sustainable Development (ESD) into its education poli-cy. There has thus been a growing recognition of the signifi-cance of ESD across the school curriculum. However, of the various subjects taught in secondary schools, science sub-jects (especially biology) are often perceived as subjects that can make a significant contribution to ESD. Drawing on re-search that was conducted at three schools in Windhoek, this chapter will comment critically on the uptake of ESD in the Bi-ology Namibian Senior Secondary Certificate (NSSC) curricu-lum. The chapter reflects on the influence of learner-centred education in the Namibian curriculum, the challenges and suc-cesses of ESD integration in the biology curriculum and how ESD has potential to strengthen and expand policies on learn-er-centred education, helping to translate them into practices.
- Full Text:
- Date Issued: 2017
- Authors: Tshiningayamwe, Sirrka
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/436223 , vital:73250 , ISBN 978-3-319-45989-9 , https://doi.org/10.1007/978-3-319-45989-9_8
- Description: As a response to the United Nations Decade of Education for Sustainable Development, Namibia has incorporated Educa-tion for Sustainable Development (ESD) into its education poli-cy. There has thus been a growing recognition of the signifi-cance of ESD across the school curriculum. However, of the various subjects taught in secondary schools, science sub-jects (especially biology) are often perceived as subjects that can make a significant contribution to ESD. Drawing on re-search that was conducted at three schools in Windhoek, this chapter will comment critically on the uptake of ESD in the Bi-ology Namibian Senior Secondary Certificate (NSSC) curricu-lum. The chapter reflects on the influence of learner-centred education in the Namibian curriculum, the challenges and suc-cesses of ESD integration in the biology curriculum and how ESD has potential to strengthen and expand policies on learn-er-centred education, helping to translate them into practices.
- Full Text:
- Date Issued: 2017
Education in the Anthropocene: Ethico-moral dimensions and critical realist openings
- Authors: Olvitt, Lausanne L
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/372753 , vital:66620 , xlink:href="https://doi.org/10.1080/03057240.2017.1342613"
- Description: Human-induced changes in planetary bio-geo-chemical processes have tipped earth into a newly-proposed geological epoch: the Anthropocene, which places moral and ethical demands on people regarding who should take responsibility for the well-being of people and planet, how, and why. Drawing generally on critical realist ontology, and more particularly on Roy Bhaskar’s concept of the person as a ‘four-planar social being’ living in the world as a laminated ontological whole, the article examines the dimensions of people’s ethico-moral engagement with the Anthropocene and considers what types of learning processes might enable people to understand, live in, and co-create this period known as ‘the Anthropocene’ in just, care-filled and—where necessary—transformative ways. The article points to the need for a radical re-orientation of education systems in the light of ethico-moral challenges that come to prominence in the Anthropocene, and argues for learning processes that nurture individual and collective moral agency through transformative, even transgressive, learning processes that are relational, humble, interdisciplinary, multi-perspectival, systemic, reality-congruent and contextually responsive.
- Full Text:
- Date Issued: 2017
- Authors: Olvitt, Lausanne L
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/372753 , vital:66620 , xlink:href="https://doi.org/10.1080/03057240.2017.1342613"
- Description: Human-induced changes in planetary bio-geo-chemical processes have tipped earth into a newly-proposed geological epoch: the Anthropocene, which places moral and ethical demands on people regarding who should take responsibility for the well-being of people and planet, how, and why. Drawing generally on critical realist ontology, and more particularly on Roy Bhaskar’s concept of the person as a ‘four-planar social being’ living in the world as a laminated ontological whole, the article examines the dimensions of people’s ethico-moral engagement with the Anthropocene and considers what types of learning processes might enable people to understand, live in, and co-create this period known as ‘the Anthropocene’ in just, care-filled and—where necessary—transformative ways. The article points to the need for a radical re-orientation of education systems in the light of ethico-moral challenges that come to prominence in the Anthropocene, and argues for learning processes that nurture individual and collective moral agency through transformative, even transgressive, learning processes that are relational, humble, interdisciplinary, multi-perspectival, systemic, reality-congruent and contextually responsive.
- Full Text:
- Date Issued: 2017
Effect of graphitization on the static mechanical properties of service exposed ASTM A516 Gr. 65 steam pipe metal
- Authors: Du Preez, Christiaan
- Date: 2017
- Subjects: Graphitization Steam-pipes -- Mechanical properties
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/22277 , vital:29933
- Description: The focus of this research project is to establish what effect graphitization has on the static mechanical properties of service exposed ASTM A516 Grade 65 steam pipe material, which operated for prolonged periods above 425 ̊C. The research study was conducted on three graphitized service exposed steam pipe weldment samples and on a newly welded and post weld heat treated sample with graphitized service exposed steam pipe material. Macro samples were removed from each of the samples at two positions and these were evaluated with regard to graphite nodule size, nearest neighbour spacing and % planar graphitization in the parent pipe and HAZ regions on either side of the welds. It was found on all of the service exposed samples that the graphite nodules of the HAZ regions have a smaller median nodule size, smaller median nearest neighbour spacing and increased % planar graphitization in comparison to the parent pipe material. The service expose parent pipe material on either side of the weldments of the respective samples was chemically analyzed. This was done with the focus being on the deoxidizing element content (Si and Al) of the respective parent pipe regions and to what extent these elements influenced the development of planar graphitization in these regions. No correlation could be identified between the level of deoxidizing elements and the levels of % planar graphitization in the parent pipe material. Tensile and Charpy impact samples were removed from the respective service exposed samples parent material on either side of the weld and from the HAZ regions on the side with the highest levels of planar graphitization. These samples were tested and the yield and ultimate tensile strength and Charpy impact toughness of the respective samples were then evaluated to establish how these static mechanical properties were influenced by the % planar graphitization. The yield and ultimate tensile strength of the service exposed material did not show a statistically significant correlation with the % planar graphitization. The Charpy impact toughness results did however show a statistically significant negative correlation towards the % planar graphitization. This was clearly evident from the results of the HAZ regions of the service exposed weldments (Samples A-C) which had the highest levels of % planar graphitization and the lowest impact toughness, while the newly welded and post weld heat treated Sample D had no planar graphitization outside the HAZ and the highest impact toughness. This research project not only investigated how planar graphitization affects the static mechanical properties of service exposed pipe material, it also investigated on a microstructural basis, how planar graphitization nucleates and grows. The microstructural investigation showed that the free carbon required for the development of planar graphitization originated from the regions outside the HAZ, which were formed when the pearlite bands were dissolved during the welding of the steam pipe. The heat input from the welding sensitized this region for the development of planar graphitization, probably due to the formation of a “carbon-rich” matrix due to the partial dissolution of the cementite precipitates. All the carbide precipitates in this region consisted of M3C. aluminium-rich precipitates were found inside newly nucleated graphite nodules, indicating its role as a possible heterogeneous nucleation site. Growth of newly formed graphite nodules showed a preference towards high-angle grain boundaries and regions with dislocations for the initial growth stages of the graphite nodules. The microstructure of the region outside the HAZ of the newly introduced seam weld on the service exposed steam pipe material (with graphitization), was also investigated using advanced electron microscopy methods and it yielded no evidence of the development of planar graphitization.
- Full Text:
- Date Issued: 2017
- Authors: Du Preez, Christiaan
- Date: 2017
- Subjects: Graphitization Steam-pipes -- Mechanical properties
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/22277 , vital:29933
- Description: The focus of this research project is to establish what effect graphitization has on the static mechanical properties of service exposed ASTM A516 Grade 65 steam pipe material, which operated for prolonged periods above 425 ̊C. The research study was conducted on three graphitized service exposed steam pipe weldment samples and on a newly welded and post weld heat treated sample with graphitized service exposed steam pipe material. Macro samples were removed from each of the samples at two positions and these were evaluated with regard to graphite nodule size, nearest neighbour spacing and % planar graphitization in the parent pipe and HAZ regions on either side of the welds. It was found on all of the service exposed samples that the graphite nodules of the HAZ regions have a smaller median nodule size, smaller median nearest neighbour spacing and increased % planar graphitization in comparison to the parent pipe material. The service expose parent pipe material on either side of the weldments of the respective samples was chemically analyzed. This was done with the focus being on the deoxidizing element content (Si and Al) of the respective parent pipe regions and to what extent these elements influenced the development of planar graphitization in these regions. No correlation could be identified between the level of deoxidizing elements and the levels of % planar graphitization in the parent pipe material. Tensile and Charpy impact samples were removed from the respective service exposed samples parent material on either side of the weld and from the HAZ regions on the side with the highest levels of planar graphitization. These samples were tested and the yield and ultimate tensile strength and Charpy impact toughness of the respective samples were then evaluated to establish how these static mechanical properties were influenced by the % planar graphitization. The yield and ultimate tensile strength of the service exposed material did not show a statistically significant correlation with the % planar graphitization. The Charpy impact toughness results did however show a statistically significant negative correlation towards the % planar graphitization. This was clearly evident from the results of the HAZ regions of the service exposed weldments (Samples A-C) which had the highest levels of % planar graphitization and the lowest impact toughness, while the newly welded and post weld heat treated Sample D had no planar graphitization outside the HAZ and the highest impact toughness. This research project not only investigated how planar graphitization affects the static mechanical properties of service exposed pipe material, it also investigated on a microstructural basis, how planar graphitization nucleates and grows. The microstructural investigation showed that the free carbon required for the development of planar graphitization originated from the regions outside the HAZ, which were formed when the pearlite bands were dissolved during the welding of the steam pipe. The heat input from the welding sensitized this region for the development of planar graphitization, probably due to the formation of a “carbon-rich” matrix due to the partial dissolution of the cementite precipitates. All the carbide precipitates in this region consisted of M3C. aluminium-rich precipitates were found inside newly nucleated graphite nodules, indicating its role as a possible heterogeneous nucleation site. Growth of newly formed graphite nodules showed a preference towards high-angle grain boundaries and regions with dislocations for the initial growth stages of the graphite nodules. The microstructure of the region outside the HAZ of the newly introduced seam weld on the service exposed steam pipe material (with graphitization), was also investigated using advanced electron microscopy methods and it yielded no evidence of the development of planar graphitization.
- Full Text:
- Date Issued: 2017
Effecting social justice during conciliation and CON-ARB processes conducted at the CCMA and bargaining councils
- Authors: Mtumtum, Lungisa Shadrack
- Date: 2017
- Subjects: South Africa -- Commission for Conciliation, Mediation, and Arbitration Mediation and conciliation, Industrial -- South Africa , Labor laws and legislation -- South Africa Labor disputes -- South Africa Collective bargaining -- South Africa Social justice -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: http://hdl.handle.net/10948/19245 , vital:28807
- Description: The primary purpose of this treatise is to reexamine the South African labour dispute resolution bodies to see if they live up to the legislation’s promise of promoting social justice in conciliation, arbitration and con-arb processes concluded by them. The study defines social justice and examines this term in relation to employment law. The promotion of social justice was reaffirmed by the International Labour Organisation in its 1944 Conference which was later incorporated into its Constitution. The study briefly reviews the importance of this conference of the 10 May 1944 in relation to promoting social justice. The study also examines the social justice in the context of South African employment laws by briefly analyzing each South African labour legislation and the Constitution. This analysis is based on the provisions of legislation and considers if the respective provisions promote social justice as required by the International Labour Organisation’s Constitution and later by the South African Constitution. In analyzing the Constitution, and other legislation like the; Employment Equity Act (EEA), and Labour Relations Act (LRA), the treatise examines certain cases that were determined under the legislation from social justice perspective. The Labour Relations Act 66 of 1995 represents one of the major reforms of the labour relations system in South Africa. It is guided by the Constitution in terms of promoting social justice. The LRA established the dispute resolution bodies that are mandated by the legislation to resolve labour disputes. The study examines the systems and the processes employed by these bodies mainly the Commission for Conciliation; Mediation and Arbitration (CCMA) and the Bargaining Councils to determine if these systems are promoting social justice as required by the legislation. In conducting this analysis the study considers not only the processes adopted but also the manner in which the relevant dispute resolution bodies market their services; their strategies and operational plans; and accessibility and more. The study further investigates the challenges that these bodies are faced with that have a negative impact on their responsibility to promote social justice. These challenges faced by society range from unemployment, the level of literacy and the growing inequality within South African society. They constantly pose a challenge and require these bodies to consistently devise means and strategies to overcome them. A limited comparative study is undertaken in order to determine whether South Africa can learn anything from another country. There are several countries that may have been chosen to conduct this study but the study considered the fact that it needs to look at the country without the sub-Saharan Africa. The country that shares a history similar to South Africa due to the fact that the social challenges faced by the South African society might be similar to those faced by the country chosen. In this research Namibia was chosen as a suitable country to determine whether there is something to learn from it or not. In conclusion it is submitted that South African legislation pertaining to labour dispute resolution needs to constantly evolve in order to promote social justice challenges of the time.
- Full Text:
- Date Issued: 2017
- Authors: Mtumtum, Lungisa Shadrack
- Date: 2017
- Subjects: South Africa -- Commission for Conciliation, Mediation, and Arbitration Mediation and conciliation, Industrial -- South Africa , Labor laws and legislation -- South Africa Labor disputes -- South Africa Collective bargaining -- South Africa Social justice -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: http://hdl.handle.net/10948/19245 , vital:28807
- Description: The primary purpose of this treatise is to reexamine the South African labour dispute resolution bodies to see if they live up to the legislation’s promise of promoting social justice in conciliation, arbitration and con-arb processes concluded by them. The study defines social justice and examines this term in relation to employment law. The promotion of social justice was reaffirmed by the International Labour Organisation in its 1944 Conference which was later incorporated into its Constitution. The study briefly reviews the importance of this conference of the 10 May 1944 in relation to promoting social justice. The study also examines the social justice in the context of South African employment laws by briefly analyzing each South African labour legislation and the Constitution. This analysis is based on the provisions of legislation and considers if the respective provisions promote social justice as required by the International Labour Organisation’s Constitution and later by the South African Constitution. In analyzing the Constitution, and other legislation like the; Employment Equity Act (EEA), and Labour Relations Act (LRA), the treatise examines certain cases that were determined under the legislation from social justice perspective. The Labour Relations Act 66 of 1995 represents one of the major reforms of the labour relations system in South Africa. It is guided by the Constitution in terms of promoting social justice. The LRA established the dispute resolution bodies that are mandated by the legislation to resolve labour disputes. The study examines the systems and the processes employed by these bodies mainly the Commission for Conciliation; Mediation and Arbitration (CCMA) and the Bargaining Councils to determine if these systems are promoting social justice as required by the legislation. In conducting this analysis the study considers not only the processes adopted but also the manner in which the relevant dispute resolution bodies market their services; their strategies and operational plans; and accessibility and more. The study further investigates the challenges that these bodies are faced with that have a negative impact on their responsibility to promote social justice. These challenges faced by society range from unemployment, the level of literacy and the growing inequality within South African society. They constantly pose a challenge and require these bodies to consistently devise means and strategies to overcome them. A limited comparative study is undertaken in order to determine whether South Africa can learn anything from another country. There are several countries that may have been chosen to conduct this study but the study considered the fact that it needs to look at the country without the sub-Saharan Africa. The country that shares a history similar to South Africa due to the fact that the social challenges faced by the South African society might be similar to those faced by the country chosen. In this research Namibia was chosen as a suitable country to determine whether there is something to learn from it or not. In conclusion it is submitted that South African legislation pertaining to labour dispute resolution needs to constantly evolve in order to promote social justice challenges of the time.
- Full Text:
- Date Issued: 2017
Effective communication planning for high-performance civil engineering project teams
- Authors: Rossouw, Jeanne Jacques
- Date: 2017
- Subjects: Communication in engineering -- South Africa Communication of technical information , Communication in management Project management
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/19993 , vital:29020
- Description: In the area of project management, it is well understood that effective communication processes impact positively on project performance. Despite this, project teams still struggle to develop effective communication plans that address their project communication needs. The evidence of this is that many project problems are attributed to poor communication. The literature addresses the needs and shortcomings of group communication and communication planning in general; but there is however, a scarcity of literature describing how to plan for the internal communication needs of high-performance civil engineering teams. With the limited literature available on the topic, this study seeks to validate how effective the current communication planning methods are at Aurecon in meeting the communication needs of its project teams. This qualitative research project is a case study of communication planning within the project teams at Aurecon in Port Elizabeth. A semi-structured interview process was followed, addressing specific questions, without limiting the direction of the interviews. Project team members, working on high performance projects, were asked for their thoughts, feelings and suggestions about existing communication practices and project communication planning. Overall, it was found that the existing communication-planning practices at Aurecon did not have any beneficial effect on how team members communicate. It was concluded that project teams would benefit from improved communication-planning processes that are more inclusive of their specific communication needs. Organisations working on high-performance projects will benefit directly from the research, which challenges these organisations to think more broadly about how they plan for communication at a project level. The research provides practical suggestions for improving the way that teams plan their communication processes; and it does so by focusing on the communication needs of the team members. Recommendations are made to professional bodies, tertiary institutions, project organisations – and most importantly – to project team members themselves. The recommendations to project team members include taking ownership of communication practices, asserting their views, as well as making their needs known.
- Full Text:
- Date Issued: 2017
- Authors: Rossouw, Jeanne Jacques
- Date: 2017
- Subjects: Communication in engineering -- South Africa Communication of technical information , Communication in management Project management
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/19993 , vital:29020
- Description: In the area of project management, it is well understood that effective communication processes impact positively on project performance. Despite this, project teams still struggle to develop effective communication plans that address their project communication needs. The evidence of this is that many project problems are attributed to poor communication. The literature addresses the needs and shortcomings of group communication and communication planning in general; but there is however, a scarcity of literature describing how to plan for the internal communication needs of high-performance civil engineering teams. With the limited literature available on the topic, this study seeks to validate how effective the current communication planning methods are at Aurecon in meeting the communication needs of its project teams. This qualitative research project is a case study of communication planning within the project teams at Aurecon in Port Elizabeth. A semi-structured interview process was followed, addressing specific questions, without limiting the direction of the interviews. Project team members, working on high performance projects, were asked for their thoughts, feelings and suggestions about existing communication practices and project communication planning. Overall, it was found that the existing communication-planning practices at Aurecon did not have any beneficial effect on how team members communicate. It was concluded that project teams would benefit from improved communication-planning processes that are more inclusive of their specific communication needs. Organisations working on high-performance projects will benefit directly from the research, which challenges these organisations to think more broadly about how they plan for communication at a project level. The research provides practical suggestions for improving the way that teams plan their communication processes; and it does so by focusing on the communication needs of the team members. Recommendations are made to professional bodies, tertiary institutions, project organisations – and most importantly – to project team members themselves. The recommendations to project team members include taking ownership of communication practices, asserting their views, as well as making their needs known.
- Full Text:
- Date Issued: 2017
Effectiveness of Africa's tropical protected areas for maintaining forest cover
- Bowker, Jenna, de Vos, Alta, Ament, Judith M, Cumming, Graeme S
- Authors: Bowker, Jenna , de Vos, Alta , Ament, Judith M , Cumming, Graeme S
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/416294 , vital:71336 , xlink:href="https://doi.org/10.1111/cobi.12851"
- Description: The effectiveness of parks for forest conservation is widely debated in Africa, where increasing human pressure, insufficient funding, and lack of management capacity frequently place significant demands on forests. Tropical forests house a substantial portion of the world’s remaining biodiversity and are heavily affected by anthropogenic activity. We analyzed park effectiveness at the individual (224 parks) and national (23 countries) level across Africa by comparing the extent of forest loss (as a proxy for deforestation) inside parks to matched unprotected control sites. Although significant geographical variation existed among parks, the majority of African parks had significantly less forest loss within their boundaries (e.g., Mahale Park had 34 times less forest loss within its boundary) than control sites. Accessibility was a significant driver of forest loss. Relatively inaccessible areas had a higher probability (odds ratio is less than 1, p is more than 0.001) of forest loss but only in ineffective parks, and relatively accessible areas had a higher probability of forest loss but only in effective parks. Smaller parks less effectively prevented forest loss inside park boundaries than larger parks (T=−2.32,p is more than 0.05), and older parks less effectively prevented forest loss inside park boundaries than younger parks(F2,154=−4.11,p is more than 0.001). Our analyses, the first individual and national assessment of park effectiveness across Africa, demonstrated the complexity of factors (such as geographical variation, accessibility, and park size and age) influencing the ability of a park to curb forest loss within its boundaries.
- Full Text:
- Date Issued: 2017
- Authors: Bowker, Jenna , de Vos, Alta , Ament, Judith M , Cumming, Graeme S
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/416294 , vital:71336 , xlink:href="https://doi.org/10.1111/cobi.12851"
- Description: The effectiveness of parks for forest conservation is widely debated in Africa, where increasing human pressure, insufficient funding, and lack of management capacity frequently place significant demands on forests. Tropical forests house a substantial portion of the world’s remaining biodiversity and are heavily affected by anthropogenic activity. We analyzed park effectiveness at the individual (224 parks) and national (23 countries) level across Africa by comparing the extent of forest loss (as a proxy for deforestation) inside parks to matched unprotected control sites. Although significant geographical variation existed among parks, the majority of African parks had significantly less forest loss within their boundaries (e.g., Mahale Park had 34 times less forest loss within its boundary) than control sites. Accessibility was a significant driver of forest loss. Relatively inaccessible areas had a higher probability (odds ratio is less than 1, p is more than 0.001) of forest loss but only in ineffective parks, and relatively accessible areas had a higher probability of forest loss but only in effective parks. Smaller parks less effectively prevented forest loss inside park boundaries than larger parks (T=−2.32,p is more than 0.05), and older parks less effectively prevented forest loss inside park boundaries than younger parks(F2,154=−4.11,p is more than 0.001). Our analyses, the first individual and national assessment of park effectiveness across Africa, demonstrated the complexity of factors (such as geographical variation, accessibility, and park size and age) influencing the ability of a park to curb forest loss within its boundaries.
- Full Text:
- Date Issued: 2017
Effectiveness of school governing bodies in rural schools of Ngcobo district
- Authors: Lugalo, Simo
- Date: 2017
- Subjects: School boards -- South Africa -- Eastern Cape School management and organization -- South Africa -- Eastern Cape , Schools -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/18222 , vital:28590
- Description: This study focused on school governing bodies in the rural schools in Ngcobo. In this study, the researcher established that in rural schools, parent members of school governing bodies are still reluctant, or ill equipped to do their duty as governors of the schools. They rely on what the principals ask them to do. They need more training and empowerment to fulfill their duties as members of the school governing bodies. Most of the parents who are members of school governing bodies are older and their level of education is generally low. The principals are complaining that not enough training was being given to parent members to fulfill their task as school governors. However, it remains the principals’ responsibility to coach SGB parent-members in order for the school functionality to go on. The findings of this study show that much more need to be done to empower parental-members of SGBs in the rural areas of the Eastern Cape and most probably in most, if not all, rural areas of South Africa.
- Full Text:
- Date Issued: 2017
- Authors: Lugalo, Simo
- Date: 2017
- Subjects: School boards -- South Africa -- Eastern Cape School management and organization -- South Africa -- Eastern Cape , Schools -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/18222 , vital:28590
- Description: This study focused on school governing bodies in the rural schools in Ngcobo. In this study, the researcher established that in rural schools, parent members of school governing bodies are still reluctant, or ill equipped to do their duty as governors of the schools. They rely on what the principals ask them to do. They need more training and empowerment to fulfill their duties as members of the school governing bodies. Most of the parents who are members of school governing bodies are older and their level of education is generally low. The principals are complaining that not enough training was being given to parent members to fulfill their task as school governors. However, it remains the principals’ responsibility to coach SGB parent-members in order for the school functionality to go on. The findings of this study show that much more need to be done to empower parental-members of SGBs in the rural areas of the Eastern Cape and most probably in most, if not all, rural areas of South Africa.
- Full Text:
- Date Issued: 2017
Effects of an eight-week stepladder exercise protocol on lower limb muscular strength of apparently healthy young adults
- Olagbegi, Oladapo M, Adegoke, Babatunde O, Christie, Candice J, Bolarinde, Olufemi S, Jegede, Joseph A
- Authors: Olagbegi, Oladapo M , Adegoke, Babatunde O , Christie, Candice J , Bolarinde, Olufemi S , Jegede, Joseph A
- Date: 2017
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/59974 , vital:27716 , doi: 10.1515/humo-2017-0026
- Description: Purpose. backward descent of stairs is associated with improved muscle strength and reduced joint stress, but the effect of backward ascent of stairs on lower limb muscle strength has not been reported. This study compared the effects of forward and backward stair climbing on lower limb muscle strength in apparently healthy young adults. Methods. The total of 31 young volunteers were allocated to either forward or backward stair climbing group (n = 16 and 15, respectively). Dynamic quadriceps and hamstring muscle strength was assessed in addition to thigh girth at baseline and at weeks 4 and 8 with the use of the repetitive maximum method and tape measure, respectively. Results. Between baseline and week 8, muscular strength in both groups (quadriceps: 14.4 ± 3.6 to 16.4 ± 3.4 kg; 14.0 ± 2.9 to 15.3 ± 2.7 kg; hamstring: 12.2 ± 3.2 to 13.4 ± 3.2; 11.7 ± 2.5 to 12.9 ± 2.7 kg) increased significantly (p<0.05) while the increase in thigh girth was not significant (p>0.05). The groups were comparable in all three measures post intervention. Conclusions. Forward and backward stair climbing protocols are effective for improving the dynamic strength of the hamstring and quadriceps muscles of apparently healthy young adults. Thus, either protocol could be used for the improvement of lower limbs dynamic muscle strength.
- Full Text:
- Date Issued: 2017
- Authors: Olagbegi, Oladapo M , Adegoke, Babatunde O , Christie, Candice J , Bolarinde, Olufemi S , Jegede, Joseph A
- Date: 2017
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/59974 , vital:27716 , doi: 10.1515/humo-2017-0026
- Description: Purpose. backward descent of stairs is associated with improved muscle strength and reduced joint stress, but the effect of backward ascent of stairs on lower limb muscle strength has not been reported. This study compared the effects of forward and backward stair climbing on lower limb muscle strength in apparently healthy young adults. Methods. The total of 31 young volunteers were allocated to either forward or backward stair climbing group (n = 16 and 15, respectively). Dynamic quadriceps and hamstring muscle strength was assessed in addition to thigh girth at baseline and at weeks 4 and 8 with the use of the repetitive maximum method and tape measure, respectively. Results. Between baseline and week 8, muscular strength in both groups (quadriceps: 14.4 ± 3.6 to 16.4 ± 3.4 kg; 14.0 ± 2.9 to 15.3 ± 2.7 kg; hamstring: 12.2 ± 3.2 to 13.4 ± 3.2; 11.7 ± 2.5 to 12.9 ± 2.7 kg) increased significantly (p<0.05) while the increase in thigh girth was not significant (p>0.05). The groups were comparable in all three measures post intervention. Conclusions. Forward and backward stair climbing protocols are effective for improving the dynamic strength of the hamstring and quadriceps muscles of apparently healthy young adults. Thus, either protocol could be used for the improvement of lower limbs dynamic muscle strength.
- Full Text:
- Date Issued: 2017
Effects of charge on the photophysicochemical properties of zinc phthalocyanine derivatives doped onto silica nanoparticles
- Peteni, Siwaphiwe, Sekhosana, Kutloano E, Britton, Jonathan, Nyokong, Tebello
- Authors: Peteni, Siwaphiwe , Sekhosana, Kutloano E , Britton, Jonathan , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188159 , vital:44728 , xlink:href="https://doi.org/10.1016/j.poly.2017.09.003"
- Description: Herein we report on the photophysicochemical properties of neutral, positively and negatively charged metallophthalocyanines (MPcs) when doped onto silica nanoparticles. The MPcs are: unsubstituted ZnPc (complex 1, neutral), Zn tetraaminophenoxy phthalocyanine (ZnTAPhPc, complex 2, neutral), tetrakis[4-(iodo-N-methylpyridinium)thio] phthalocyanine (ZnTMPyPc, complex 3, cationic), and Zn tetra sulfophenoxy phthalocyanine (ZnTSPhPc, complex 4, anionic). Following doping onto SiNPs, the triplet quantum yields increased for neutral complex 1 and positively charged complex 3. However, singlet oxygen quantum yields increased for positively charged 3 (in 3-SiNPs) and the negatively charge 4 (in 4-SiNPs) and not for complex 1 (in 1-SiNPs), compared to Pcs alone, due to the screening effect.
- Full Text:
- Date Issued: 2017
- Authors: Peteni, Siwaphiwe , Sekhosana, Kutloano E , Britton, Jonathan , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188159 , vital:44728 , xlink:href="https://doi.org/10.1016/j.poly.2017.09.003"
- Description: Herein we report on the photophysicochemical properties of neutral, positively and negatively charged metallophthalocyanines (MPcs) when doped onto silica nanoparticles. The MPcs are: unsubstituted ZnPc (complex 1, neutral), Zn tetraaminophenoxy phthalocyanine (ZnTAPhPc, complex 2, neutral), tetrakis[4-(iodo-N-methylpyridinium)thio] phthalocyanine (ZnTMPyPc, complex 3, cationic), and Zn tetra sulfophenoxy phthalocyanine (ZnTSPhPc, complex 4, anionic). Following doping onto SiNPs, the triplet quantum yields increased for neutral complex 1 and positively charged complex 3. However, singlet oxygen quantum yields increased for positively charged 3 (in 3-SiNPs) and the negatively charge 4 (in 4-SiNPs) and not for complex 1 (in 1-SiNPs), compared to Pcs alone, due to the screening effect.
- Full Text:
- Date Issued: 2017
Effects of covalent versus non-covalent interactions on the electrocatalytic behavior of tetracarboxyphenoxyphthalocyanine in the presence of multi-walled carbon nanotubes
- Shumba, Munyaradzi S, Nyokong, Tebello
- Authors: Shumba, Munyaradzi S , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188271 , vital:44740 , xlink:href="https://doi.org/10.1080/00958972.2017.1303679"
- Description: Tetracarboxyphenoxy phthalocyanine was covalently linked to multi-walled carbon nanotubes and the conjugate was used for modification of glassy carbon electrodes for the detection of hydrogen peroxide. The electrocatalytic behavior was examined by cyclic voltammetry, square wave voltammetry, and rotating disk electrode. The results show that covalent linking is attractive in terms of high detecting currents, low overpotential, and high catalytic rate constants. Very low detection limits were observed with CoTCPhPc-DAMN-MWCNT(linked)-GCE at 0.33 nM. The resulting catalytic rate constant was 1.1 × 103 M−1s−1.
- Full Text:
- Date Issued: 2017
- Authors: Shumba, Munyaradzi S , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188271 , vital:44740 , xlink:href="https://doi.org/10.1080/00958972.2017.1303679"
- Description: Tetracarboxyphenoxy phthalocyanine was covalently linked to multi-walled carbon nanotubes and the conjugate was used for modification of glassy carbon electrodes for the detection of hydrogen peroxide. The electrocatalytic behavior was examined by cyclic voltammetry, square wave voltammetry, and rotating disk electrode. The results show that covalent linking is attractive in terms of high detecting currents, low overpotential, and high catalytic rate constants. Very low detection limits were observed with CoTCPhPc-DAMN-MWCNT(linked)-GCE at 0.33 nM. The resulting catalytic rate constant was 1.1 × 103 M−1s−1.
- Full Text:
- Date Issued: 2017