First steps in the development of a water temperature model framework for refining the ecological Reserve in South African rivers
- Rivers-Moore, N A, Hughes, Denis A, Mantel, Sukhmani K, Hill, Trevor R
- Authors: Rivers-Moore, N A , Hughes, Denis A , Mantel, Sukhmani K , Hill, Trevor R
- Date: 2008-10-05
- Language: English
- Type: text , Article
- Identifier: vital:7092 , http://hdl.handle.net/10962/d1012425
- Description: Ecological Reserve determination for rivers in South Africa presently does not include a water temperature component, in spite of its importance in determining species distribution patterns. To achieve this requires an understanding of how lotic thermographs from South African rivers differ from northern hemisphere rivers, to avoid mismanaging rivers based on incorrect regional assumptions. Hourly water temperatures from 20 sites in four river systems, representing a range of latitudes, altitudes and stream orders, were assessed using a range of metrics. These data were analysed using principal component analyses and multiple linear regressions to understand what variables a water temperature model for use in ecoregions within South Africa should include. While temperature data are generally lacking in low- and higher-order South African rivers, data suggest that South African rivers are warmer than northern hemisphere rivers. Water temperatures could be grouped into cool, warm and intermediate types. Based on temperature time series analyses, this paper argues that a suitable water-temperature model for use in ecological Reserve determinations should be dynamic, include flow and air temperature variables, and be adaptive through a heat exchange coefficient term. The inclusion of water temperature in the determination and management of river ecological Reserves would allow for more holistic application of the National Water Act's ecological management provisions. Water temperature guidelines added to the ecological Reserve could be integrated into heuristic aquatic monitoring programmes within priority areas identified in regional conservation plans.
- Full Text:
- Date Issued: 2008-10-05
- Authors: Rivers-Moore, N A , Hughes, Denis A , Mantel, Sukhmani K , Hill, Trevor R
- Date: 2008-10-05
- Language: English
- Type: text , Article
- Identifier: vital:7092 , http://hdl.handle.net/10962/d1012425
- Description: Ecological Reserve determination for rivers in South Africa presently does not include a water temperature component, in spite of its importance in determining species distribution patterns. To achieve this requires an understanding of how lotic thermographs from South African rivers differ from northern hemisphere rivers, to avoid mismanaging rivers based on incorrect regional assumptions. Hourly water temperatures from 20 sites in four river systems, representing a range of latitudes, altitudes and stream orders, were assessed using a range of metrics. These data were analysed using principal component analyses and multiple linear regressions to understand what variables a water temperature model for use in ecoregions within South Africa should include. While temperature data are generally lacking in low- and higher-order South African rivers, data suggest that South African rivers are warmer than northern hemisphere rivers. Water temperatures could be grouped into cool, warm and intermediate types. Based on temperature time series analyses, this paper argues that a suitable water-temperature model for use in ecological Reserve determinations should be dynamic, include flow and air temperature variables, and be adaptive through a heat exchange coefficient term. The inclusion of water temperature in the determination and management of river ecological Reserves would allow for more holistic application of the National Water Act's ecological management provisions. Water temperature guidelines added to the ecological Reserve could be integrated into heuristic aquatic monitoring programmes within priority areas identified in regional conservation plans.
- Full Text:
- Date Issued: 2008-10-05
An investigation into electronic-source plagiarism in a first-year essay assignment
- Authors: Ellery, Karen
- Date: 2008
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/70114 , vital:29621 , https://doi.org/10.1080/02602930701772788
- Description: Since the emergence of the electronic era, plagiarism has become an increasingly prevalent problem at tertiary institutions. This study investigated the role electronic sources of information played in influencing plagiarism in an essay assignment in a first-year geography module at the University of KwaZulu-Natal in South Africa. Despite explicit instruction in tutorials on academic writing, referencing and plagiarism, a quarter of students still plagiarised in their essay, with the majority having done so off the Internet. A survey questionnaire and interviews revealed that not only did the school writing experience prepare students poorly for academic writing discourses, but also highlighted that student ignorance with regard to acknowledgement of electronic sources, a pervasive perception of difference between electronic and print sources, as well as the availability of the copy-and-paste facility which reinforces the product view of writing, all contributed towards electronic-source plagiarism. Active instructional engagement with electronic-source material, and open dialogue on ownership of knowledge as well as on moral and ethical issues with students, are recommended as strategies to overcome such plagiarism.
- Full Text:
- Date Issued: 2008
- Authors: Ellery, Karen
- Date: 2008
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/70114 , vital:29621 , https://doi.org/10.1080/02602930701772788
- Description: Since the emergence of the electronic era, plagiarism has become an increasingly prevalent problem at tertiary institutions. This study investigated the role electronic sources of information played in influencing plagiarism in an essay assignment in a first-year geography module at the University of KwaZulu-Natal in South Africa. Despite explicit instruction in tutorials on academic writing, referencing and plagiarism, a quarter of students still plagiarised in their essay, with the majority having done so off the Internet. A survey questionnaire and interviews revealed that not only did the school writing experience prepare students poorly for academic writing discourses, but also highlighted that student ignorance with regard to acknowledgement of electronic sources, a pervasive perception of difference between electronic and print sources, as well as the availability of the copy-and-paste facility which reinforces the product view of writing, all contributed towards electronic-source plagiarism. Active instructional engagement with electronic-source material, and open dialogue on ownership of knowledge as well as on moral and ethical issues with students, are recommended as strategies to overcome such plagiarism.
- Full Text:
- Date Issued: 2008
Applications of thermal spray technology for surface protection
- Authors: Gorlach, I A
- Subjects: Metal spraying , Surfaces (Technology)
- Language: English
- Type: text , Lectures
- Identifier: http://hdl.handle.net/10948/21866 , vital:29795
- Description: With the rapid development of modern industry, the quality of surfaces of structures, products and components is important in terms of many aspects such as efficiency, reliability, appearance, maintenance costs and economy. A local failure on the surface usually causes the entire component to be rejected or it may lead to a failure of a machine or structure. It is estimated that in developed countries, the loss caused by corrosion is up to 2-4% of gross national product [1]. Thus, many countries have made great efforts to improve the surface performance of parts in order to enhance the reliability of mechanical equipment and prolong their service life.
- Full Text: false
- Authors: Gorlach, I A
- Subjects: Metal spraying , Surfaces (Technology)
- Language: English
- Type: text , Lectures
- Identifier: http://hdl.handle.net/10948/21866 , vital:29795
- Description: With the rapid development of modern industry, the quality of surfaces of structures, products and components is important in terms of many aspects such as efficiency, reliability, appearance, maintenance costs and economy. A local failure on the surface usually causes the entire component to be rejected or it may lead to a failure of a machine or structure. It is estimated that in developed countries, the loss caused by corrosion is up to 2-4% of gross national product [1]. Thus, many countries have made great efforts to improve the surface performance of parts in order to enhance the reliability of mechanical equipment and prolong their service life.
- Full Text: false
Employee performance, leadership style and emotional intelligence: an exploratory study in a South African parastatal
- Baxter, Jeremy, Hayward, Brett A, Amos, Trevor L
- Authors: Baxter, Jeremy , Hayward, Brett A , Amos, Trevor L
- Date: 2008
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/142793 , vital:38117 , DOI: https://doi.org/10.4102/ac.v8i1.57
- Description: The purpose of this research is to explore the relationship between employee performance, leadership style and emotional intelligence in the context of a South African parastatal.
- Full Text:
- Date Issued: 2008
- Authors: Baxter, Jeremy , Hayward, Brett A , Amos, Trevor L
- Date: 2008
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/142793 , vital:38117 , DOI: https://doi.org/10.4102/ac.v8i1.57
- Description: The purpose of this research is to explore the relationship between employee performance, leadership style and emotional intelligence in the context of a South African parastatal.
- Full Text:
- Date Issued: 2008
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