Addressing the idiosyncrasies of contemporary notation in recorder compositions, with specific references to unconventional symbols in Music for a bird by Hans-Martin Linde and Sieben Stucke fur altblokflote by Markus Zahnhausen
- Authors: Bartle, Lynne
- Date: 2009
- Subjects: Musical notation , Musical notation -- Study and teaching , Musical notation -- History , Music -- 20th century
- Language: English
- Type: Thesis , Masters , MMus
- Identifier: vital:8516 , http://hdl.handle.net/10948/920 , http://hdl.handle.net/10948/d1012065 , Musical notation , Musical notation -- Study and teaching , Musical notation -- History , Music -- 20th century
- Description: This treatise provides recorder performers and teachers with a guide to understanding the unconventional notation symbols encountered in Music for a Bird by Hans-Martin Linde and Sieben Stücke Für Altblockflöte by Markus Zahnhausen. Given the context of the overall history of notation, it argues that the idiosyncrasies of the unconventional notation symbols encountered in the recorder repertoire of contemporary composers such as Linde and Zahnhausen are by no means an anomaly. Throughout history, notated scores have functioned merely as incomplete guides to the reconstruction and the realization of musical works. Along with the decoding of these instructions, a host of acculturated meanings have always been taken for granted on the part of the writers of such guidelines. In the light of the modernist crisis and the resultant exacerbation of the gulf between composers and their audience, however, it would seem that the need for such acculturated intervention is greater then ever before. This treatise serves to bridge the gulf between the works of Linde and Zahnhausen on the one hand, and the average performer and teacher of the recorder on the other, by offering an analysis both of the meaning of the unconventional symbols these works contain as well as of the method according to which they should be executed on the recorder.
- Full Text:
- Date Issued: 2009
- Authors: Bartle, Lynne
- Date: 2009
- Subjects: Musical notation , Musical notation -- Study and teaching , Musical notation -- History , Music -- 20th century
- Language: English
- Type: Thesis , Masters , MMus
- Identifier: vital:8516 , http://hdl.handle.net/10948/920 , http://hdl.handle.net/10948/d1012065 , Musical notation , Musical notation -- Study and teaching , Musical notation -- History , Music -- 20th century
- Description: This treatise provides recorder performers and teachers with a guide to understanding the unconventional notation symbols encountered in Music for a Bird by Hans-Martin Linde and Sieben Stücke Für Altblockflöte by Markus Zahnhausen. Given the context of the overall history of notation, it argues that the idiosyncrasies of the unconventional notation symbols encountered in the recorder repertoire of contemporary composers such as Linde and Zahnhausen are by no means an anomaly. Throughout history, notated scores have functioned merely as incomplete guides to the reconstruction and the realization of musical works. Along with the decoding of these instructions, a host of acculturated meanings have always been taken for granted on the part of the writers of such guidelines. In the light of the modernist crisis and the resultant exacerbation of the gulf between composers and their audience, however, it would seem that the need for such acculturated intervention is greater then ever before. This treatise serves to bridge the gulf between the works of Linde and Zahnhausen on the one hand, and the average performer and teacher of the recorder on the other, by offering an analysis both of the meaning of the unconventional symbols these works contain as well as of the method according to which they should be executed on the recorder.
- Full Text:
- Date Issued: 2009
Towards enhancing indigenous language acquisition skills through MMORPGs
- Kaschula, Russell H, Mostert, André
- Authors: Kaschula, Russell H , Mostert, André
- Date: 2010
- Subjects: Indigenous peoples -- Languages -- Study and teaching -- South Africa , Language and languags -- Computer-assisted instruction , Language and languags -- Study and teaching -- Technological innovation , Language acquisition , Computer games
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/59343 , vital:27559 , http://alternation.ukzn.ac.za/Files/docs/17.1/08%20Kas%20FIN.pdf
- Description: The growing interest and access to massively multiplayer online role-playing games (MMORPG) has opened up significant new scope for educational methodologies, from standard language teaching options through to formalising the skills that a ‘player’ develops through their quests and other activities. This scope is extensive and has created numerous opportunities for innovation both within education and the world of work. This is evidenced by the increasing presence of educational establishments in the virtual world, with Second Life being the most popular for conventional educational purposes. In Second Life and many other realms participants are earning some income and in some cases enjoying a reasonable living from online activities, while developing their skills base. These MMORPGs may open opportunities for promoting language acquisition provided this is located within a suitably attractive realm; ‘players’ would then engage in activities that would contribute to their abilities to use the indigenous languages in everyday life. This article explores how such a system could be developed and the likely contribution it could make to promote a multilingual environment at school and post school levels. Further, it will identify the implications for the future of teaching and learning through the harnessing of MMORPGs.
- Full Text:
- Date Issued: 2010
- Authors: Kaschula, Russell H , Mostert, André
- Date: 2010
- Subjects: Indigenous peoples -- Languages -- Study and teaching -- South Africa , Language and languags -- Computer-assisted instruction , Language and languags -- Study and teaching -- Technological innovation , Language acquisition , Computer games
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/59343 , vital:27559 , http://alternation.ukzn.ac.za/Files/docs/17.1/08%20Kas%20FIN.pdf
- Description: The growing interest and access to massively multiplayer online role-playing games (MMORPG) has opened up significant new scope for educational methodologies, from standard language teaching options through to formalising the skills that a ‘player’ develops through their quests and other activities. This scope is extensive and has created numerous opportunities for innovation both within education and the world of work. This is evidenced by the increasing presence of educational establishments in the virtual world, with Second Life being the most popular for conventional educational purposes. In Second Life and many other realms participants are earning some income and in some cases enjoying a reasonable living from online activities, while developing their skills base. These MMORPGs may open opportunities for promoting language acquisition provided this is located within a suitably attractive realm; ‘players’ would then engage in activities that would contribute to their abilities to use the indigenous languages in everyday life. This article explores how such a system could be developed and the likely contribution it could make to promote a multilingual environment at school and post school levels. Further, it will identify the implications for the future of teaching and learning through the harnessing of MMORPGs.
- Full Text:
- Date Issued: 2010
Self-esteem and traumatic stress severity in individuals from individualists and collectivists’ perspectives
- Authors: Singh, Romisha
- Date: 2018
- Subjects: Post-traumatic stress disorder , Self-esteem Self-esteem -- Cross-cultural studies
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/23186 , vital:30451
- Description: It is evident that traumatic stress influences cultures differently but how this happens is still unclear. It may be assumed that the differences in PTSD severity between independent and interdependent cultures may exist due to the differential influence of individual self-esteem. Although some international research is prevalent, none address the issue of self-esteem and the cultural element of independent vs interdependent specifically and to the knowledge of the researcher no similar South African research exists. To investigate whether independent or interdependent classification mediates the influence of individual self-esteem on traumatic stress severity, a quantitative correlational design is used. Based on a sample size of N=197, an independent sample t-test – with unequal group sizes - suggested that individuals from independent and interdependent cultures reportedly expressed post-traumatic symptomology similarly. Results from the ANCOVA have indicated that individual self-esteem does not influence traumatic stress severity and that independently classified White English speaking participants between the ages of 21-30 are more likely to experience higher levels of traumatic stress severity as opposed to interdependently classified Coloured Afrikaans speaking participants between the ages of 21-30. Finally, chi-square analysis indicated that ethnicity cannot be deemed as a variable that can predict culture classification. However, the varying home language preferences in cultures suggest a possibility of varying ethnic identities within each of the ethnic groups.
- Full Text:
- Date Issued: 2018
- Authors: Singh, Romisha
- Date: 2018
- Subjects: Post-traumatic stress disorder , Self-esteem Self-esteem -- Cross-cultural studies
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/23186 , vital:30451
- Description: It is evident that traumatic stress influences cultures differently but how this happens is still unclear. It may be assumed that the differences in PTSD severity between independent and interdependent cultures may exist due to the differential influence of individual self-esteem. Although some international research is prevalent, none address the issue of self-esteem and the cultural element of independent vs interdependent specifically and to the knowledge of the researcher no similar South African research exists. To investigate whether independent or interdependent classification mediates the influence of individual self-esteem on traumatic stress severity, a quantitative correlational design is used. Based on a sample size of N=197, an independent sample t-test – with unequal group sizes - suggested that individuals from independent and interdependent cultures reportedly expressed post-traumatic symptomology similarly. Results from the ANCOVA have indicated that individual self-esteem does not influence traumatic stress severity and that independently classified White English speaking participants between the ages of 21-30 are more likely to experience higher levels of traumatic stress severity as opposed to interdependently classified Coloured Afrikaans speaking participants between the ages of 21-30. Finally, chi-square analysis indicated that ethnicity cannot be deemed as a variable that can predict culture classification. However, the varying home language preferences in cultures suggest a possibility of varying ethnic identities within each of the ethnic groups.
- Full Text:
- Date Issued: 2018
Agreement and coordination in XiTsonga, SeSotho and IsiXhosa: an optimality theoretic perspective
- Authors: Mitchley, Hazel
- Date: 2016
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/3423 , vital:20491
- Description: This thesis provides a unified Optimality Theoretic analysis of subject-verb agreement with coordinated preverbal subjects in three Southern Bantu languages: Xitsonga (S53), Sesotho (S33), and isiXhosa (S41). This analysis is then used to formulate a typology of agreement resolution strategies and the contexts which trigger them. Although some accounts in the Bantu literature suggest that agreement with coordinate structures is avoided by speakers (e.g. Schadeberg 1992, Voeltz 1971) especially when conjuncts are from different noun classes, I show that there is ample evidence to the contrary, and that the subject marker used is dependent on several factors, including (i) the [-HUMAN] specification on the conjuncts, (ii) whether the conjuncts are singular or plural, (iii) whether or not the conjuncts both carry the same noun class feature, and (iv) the order of the conjuncts. This thesis shows that there are various agreement resolution strategies which can beused: 1) agreement with the [+HUMAN] feature on the conjuncts, 2) agreement with the[-HUMAN] feature on the conjuncts, 3) agreement with the noun class feature on both conjuncts, 4) agreement with the noun class feature on the conjunct closest to the verb, and 5) agreement with the noun class feature on the conjunct furthest from the verb. Not all of these strategies are used by all languages, nor are these strategies interchangeable in the languages which do use them – instead, multiple factors conspire to trigger the use of a specific agreement strategy within a specific agreement featural context. I show that these effects can be captured using Optimality Theory (Prince and Smolensky 2004). The analysis makes use of seven constraints: RES#, MAX[+H], MAX[-H], DEP[-H], MAXNC, DEPNC, and AGREECLOSEST. The hierarchical ranking of these constraints not only accounts for the confinement of particular strategies to specific agreement featural contexts within a language, but also accounts for the cross-linguistic differences in the use of these strategies. I end off by examining the typological implications which follow from the OT analysis provided in this thesis.
- Full Text:
- Date Issued: 2016
- Authors: Mitchley, Hazel
- Date: 2016
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/3423 , vital:20491
- Description: This thesis provides a unified Optimality Theoretic analysis of subject-verb agreement with coordinated preverbal subjects in three Southern Bantu languages: Xitsonga (S53), Sesotho (S33), and isiXhosa (S41). This analysis is then used to formulate a typology of agreement resolution strategies and the contexts which trigger them. Although some accounts in the Bantu literature suggest that agreement with coordinate structures is avoided by speakers (e.g. Schadeberg 1992, Voeltz 1971) especially when conjuncts are from different noun classes, I show that there is ample evidence to the contrary, and that the subject marker used is dependent on several factors, including (i) the [-HUMAN] specification on the conjuncts, (ii) whether the conjuncts are singular or plural, (iii) whether or not the conjuncts both carry the same noun class feature, and (iv) the order of the conjuncts. This thesis shows that there are various agreement resolution strategies which can beused: 1) agreement with the [+HUMAN] feature on the conjuncts, 2) agreement with the[-HUMAN] feature on the conjuncts, 3) agreement with the noun class feature on both conjuncts, 4) agreement with the noun class feature on the conjunct closest to the verb, and 5) agreement with the noun class feature on the conjunct furthest from the verb. Not all of these strategies are used by all languages, nor are these strategies interchangeable in the languages which do use them – instead, multiple factors conspire to trigger the use of a specific agreement strategy within a specific agreement featural context. I show that these effects can be captured using Optimality Theory (Prince and Smolensky 2004). The analysis makes use of seven constraints: RES#, MAX[+H], MAX[-H], DEP[-H], MAXNC, DEPNC, and AGREECLOSEST. The hierarchical ranking of these constraints not only accounts for the confinement of particular strategies to specific agreement featural contexts within a language, but also accounts for the cross-linguistic differences in the use of these strategies. I end off by examining the typological implications which follow from the OT analysis provided in this thesis.
- Full Text:
- Date Issued: 2016
Introducing a learning management system in a large first year class: impact on lecturers and students
- Snowball, Jeanette D, Mostert, Markus
- Authors: Snowball, Jeanette D , Mostert, Markus
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68631 , vital:29297 , https://hdl.handle.net/10520/EJC37639
- Description: Publisher version , The challenges of teaching large classes are well documented in the literature on teaching in higher education. Information and communication technologies (ICTs) have the potential to address some of these challenges, but, used inappropriately, technology can perpetuate entrenched practices and simply support performance models of teaching that encourage transmission approaches to learning. This article reports on the impact of implementing a learning management system (LMS) in a first year introductory macroeconomics course with 600 students in a blended learning context. Experiences of the course coordinator, lecturers and an educational technologist are discussed and data was also collected on student perceptions via a course evaluation questionnaire. Results show that the LMS was successful in a number of areas, particularly in improving the lecturers' accessibility to students and in encouraging interaction and participations in online discussion forums.
- Full Text: false
- Date Issued: 2010
- Authors: Snowball, Jeanette D , Mostert, Markus
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68631 , vital:29297 , https://hdl.handle.net/10520/EJC37639
- Description: Publisher version , The challenges of teaching large classes are well documented in the literature on teaching in higher education. Information and communication technologies (ICTs) have the potential to address some of these challenges, but, used inappropriately, technology can perpetuate entrenched practices and simply support performance models of teaching that encourage transmission approaches to learning. This article reports on the impact of implementing a learning management system (LMS) in a first year introductory macroeconomics course with 600 students in a blended learning context. Experiences of the course coordinator, lecturers and an educational technologist are discussed and data was also collected on student perceptions via a course evaluation questionnaire. Results show that the LMS was successful in a number of areas, particularly in improving the lecturers' accessibility to students and in encouraging interaction and participations in online discussion forums.
- Full Text: false
- Date Issued: 2010
Representations of the ‘other’: a comparison between Roman descriptions of Britons, Gauls and Germans pre-AD 300 and Sir Harry Smith’s portrayal of the Xhosa 1830s – 1850s
- Authors: Van Wezel, Amy Hester
- Date: 2016
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/4223 , vital:20634
- Description: Stereotypical representations of an ‘ethnically’ or ‘racially’ different ‘other’ in ancient texts would seem to reappear throughout history. By comparing Roman views of Britons, Gauls and Germans, with Sir Harry Smith’s views of the Xhosa, this study seeks to explore the extent to which these stereotypical images were employed and for what reasons. Through close textual analyses, the descriptions of these peoples are examined and compared, taking into consideration the different authors’ context and agendas. By highlighting Caesar’s views of the abilities of the ‘other’ and Tacitus’ judgements of the moral character of the ‘other’, compared with Smith’s view of the same, the study aims to draw out the role of the author’s ‘self’ in complex and contradictory representations of the ‘other’, while arguing that various overwhelmingly negative images served to justify imperial conquest and rule. The extent to which the ‘other’ was perceived as remote and different from themselves, epitomised in the dichotomy between the ‘barbarism’ and ‘civilisation’, is examined, comparing a variety of Roman authors with Smith. The similar idea of ‘civilising missions’ are discussed, while acknowledging the differences between the policies of the Roman and British Empires toward the ‘other’. The connections between how the ‘other’ was portrayed in relation to ‘Empire’ and the ways in which they were treated is also explored stressing even further the different approaches taken by Roman and British authorities to include these peoples within their Empires. While certain stereotypes are shown to have persisted from Roman times, reappearing in the writing of Sir Harry Smith, summed up in the archetypal ‘barbarian’, I argue that the use of these images was varied, inconsistent and reflected more the motives and personalities of the writers themselves, whofor the most part ascribed to imperial ideologies.
- Full Text:
- Date Issued: 2016
- Authors: Van Wezel, Amy Hester
- Date: 2016
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/4223 , vital:20634
- Description: Stereotypical representations of an ‘ethnically’ or ‘racially’ different ‘other’ in ancient texts would seem to reappear throughout history. By comparing Roman views of Britons, Gauls and Germans, with Sir Harry Smith’s views of the Xhosa, this study seeks to explore the extent to which these stereotypical images were employed and for what reasons. Through close textual analyses, the descriptions of these peoples are examined and compared, taking into consideration the different authors’ context and agendas. By highlighting Caesar’s views of the abilities of the ‘other’ and Tacitus’ judgements of the moral character of the ‘other’, compared with Smith’s view of the same, the study aims to draw out the role of the author’s ‘self’ in complex and contradictory representations of the ‘other’, while arguing that various overwhelmingly negative images served to justify imperial conquest and rule. The extent to which the ‘other’ was perceived as remote and different from themselves, epitomised in the dichotomy between the ‘barbarism’ and ‘civilisation’, is examined, comparing a variety of Roman authors with Smith. The similar idea of ‘civilising missions’ are discussed, while acknowledging the differences between the policies of the Roman and British Empires toward the ‘other’. The connections between how the ‘other’ was portrayed in relation to ‘Empire’ and the ways in which they were treated is also explored stressing even further the different approaches taken by Roman and British authorities to include these peoples within their Empires. While certain stereotypes are shown to have persisted from Roman times, reappearing in the writing of Sir Harry Smith, summed up in the archetypal ‘barbarian’, I argue that the use of these images was varied, inconsistent and reflected more the motives and personalities of the writers themselves, whofor the most part ascribed to imperial ideologies.
- Full Text:
- Date Issued: 2016
Population dynamics, fire, and reproductive ecology of Oldenburgia grandis (Asteraceae), an unusual fynbos tree endemic to the Eastern Cape
- Authors: Mostert, Emma Charlotte
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/365268 , vital:65722
- Description: Thesis embargoed. Possible release date set for early 2024. , Thesis (MSc) -- Faculty of Science, Botany, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Mostert, Emma Charlotte
- Date: 2022-10-14
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/365268 , vital:65722
- Description: Thesis embargoed. Possible release date set for early 2024. , Thesis (MSc) -- Faculty of Science, Botany, 2022
- Full Text:
- Date Issued: 2022-10-14
From Technauriture to Cultauriture: Developing a Coherent Digitisation Paradigm for Enhancing Cultural Impact
- Mostert, Andre, Lisney, Bob, Maroko, Geoffrey M, Kaschula, Russell H
- Authors: Mostert, Andre , Lisney, Bob , Maroko, Geoffrey M , Kaschula, Russell H
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124528 , vital:35625 , http://www.ijscl.net/article_26650.html
- Description: Developing suitable frameworks and paradigms (theoretical and practical) is a challenge for all disciplines in the face of rapid technological changes. Technological advances are fundamentally changing discourse in many well-established areas of research; from advances in understanding the brain, questioning the informed wisdom of sectors of the brain, through to impacts of social networks on sociology, to digitisation of culture. Technology’s potential is a double-edged sword which calls for coherent and reflective practices, to avoid the many pitfalls which abound. Kaschula recognised this as far back as 2004 in terms of orality, oral societies, and developed Technauriture as a framing solution. Drawing from this experience, the authors aim to expand the concept to offer a framing paradigm for culture in the form of Cultauriture. In this article the concept of Cultauriture is introduced and expanded to create a base for further research and dialogue with and between cultural practitioners, artists and policy makers.
- Full Text:
- Date Issued: 2017
- Authors: Mostert, Andre , Lisney, Bob , Maroko, Geoffrey M , Kaschula, Russell H
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124528 , vital:35625 , http://www.ijscl.net/article_26650.html
- Description: Developing suitable frameworks and paradigms (theoretical and practical) is a challenge for all disciplines in the face of rapid technological changes. Technological advances are fundamentally changing discourse in many well-established areas of research; from advances in understanding the brain, questioning the informed wisdom of sectors of the brain, through to impacts of social networks on sociology, to digitisation of culture. Technology’s potential is a double-edged sword which calls for coherent and reflective practices, to avoid the many pitfalls which abound. Kaschula recognised this as far back as 2004 in terms of orality, oral societies, and developed Technauriture as a framing solution. Drawing from this experience, the authors aim to expand the concept to offer a framing paradigm for culture in the form of Cultauriture. In this article the concept of Cultauriture is introduced and expanded to create a base for further research and dialogue with and between cultural practitioners, artists and policy makers.
- Full Text:
- Date Issued: 2017
Where angels fear to tread: online peer-assessment in a large first-year class
- Mostert, Markus, Snowball, Jeanette D
- Authors: Mostert, Markus , Snowball, Jeanette D
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68845 , vital:29330 , https://doi.org/10.1080/02602938.2012.683770
- Description: Publisher version , In the context of widening participation, large classes and increased diversity, assessment of student learning is becoming increasingly problematic in that providing formative feedback aimed at developing student writing proves to be particularly laborious. Although the potential value of peer assessment has been well documented in the literature, the associated administrative burden, also in relation to managing anonymity and intellectual ownership, makes this option less attractive, particularly in large classes. A potential solution involves the use of information and communication technologies to automate the logistics associated with peer assessment in a time-efficient way. However, uptake of such systems in the higher education community is limited, and research in this area is only beginning. This case study reports on the use of the Moodle Workshop module for formative peer assessment of students’ individual work in a first-year introductory macro-economics class of over 800 students. Data were collected through an end-of-course evaluation survey of students. The study found that using the feature-rich Workshop module not only addressed many of the practical challenges associated with paper-based peer assessments, but also provided a range of additional options for enhancing validity and reliability of peer assessments that would not be possible with paper-based systems.
- Full Text: false
- Date Issued: 2013
- Authors: Mostert, Markus , Snowball, Jeanette D
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68845 , vital:29330 , https://doi.org/10.1080/02602938.2012.683770
- Description: Publisher version , In the context of widening participation, large classes and increased diversity, assessment of student learning is becoming increasingly problematic in that providing formative feedback aimed at developing student writing proves to be particularly laborious. Although the potential value of peer assessment has been well documented in the literature, the associated administrative burden, also in relation to managing anonymity and intellectual ownership, makes this option less attractive, particularly in large classes. A potential solution involves the use of information and communication technologies to automate the logistics associated with peer assessment in a time-efficient way. However, uptake of such systems in the higher education community is limited, and research in this area is only beginning. This case study reports on the use of the Moodle Workshop module for formative peer assessment of students’ individual work in a first-year introductory macro-economics class of over 800 students. Data were collected through an end-of-course evaluation survey of students. The study found that using the feature-rich Workshop module not only addressed many of the practical challenges associated with paper-based peer assessments, but also provided a range of additional options for enhancing validity and reliability of peer assessments that would not be possible with paper-based systems.
- Full Text: false
- Date Issued: 2013
Where angels fear to tread: online peer-assessment in a large first-year class
- Mostert, Markus, Snowball, Jeanette D
- Authors: Mostert, Markus , Snowball, Jeanette D
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/69289 , vital:29480 , https://doi.org/10.1080/02602938.2012.683770
- Description: In the context of widening participation, large classes and increased diversity, assessment of student learning is becoming increasingly problematic in that providing formative feedback aimed at developing student writing proves to be particularly laborious. Although the potential value of peer assessment has been well documented in the literature, the associated administrative burden, also in relation to managing anonymity and intellectual ownership, makes this option less attractive, particularly in large classes. A potential solution involves the use of information and communication technologies to automate the logistics associated with peer assessment in a time-efficient way. However, uptake of such systems in the higher education community is limited, and research in this area is only beginning. This case study reports on the use of the Moodle Workshop module for formative peer assessment of students’ individual work in a first-year introductory macro-economics class of over 800 students. Data were collected through an end-of-course evaluation survey of students. The study found that using the feature-rich Workshop module not only addressed many of the practical challenges associated with paper-based peer assessments, but also provided a range of additional options for enhancing validity and reliability of peer assessments that would not be possible with paper-based systems.
- Full Text: false
- Date Issued: 2012
- Authors: Mostert, Markus , Snowball, Jeanette D
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/69289 , vital:29480 , https://doi.org/10.1080/02602938.2012.683770
- Description: In the context of widening participation, large classes and increased diversity, assessment of student learning is becoming increasingly problematic in that providing formative feedback aimed at developing student writing proves to be particularly laborious. Although the potential value of peer assessment has been well documented in the literature, the associated administrative burden, also in relation to managing anonymity and intellectual ownership, makes this option less attractive, particularly in large classes. A potential solution involves the use of information and communication technologies to automate the logistics associated with peer assessment in a time-efficient way. However, uptake of such systems in the higher education community is limited, and research in this area is only beginning. This case study reports on the use of the Moodle Workshop module for formative peer assessment of students’ individual work in a first-year introductory macro-economics class of over 800 students. Data were collected through an end-of-course evaluation survey of students. The study found that using the feature-rich Workshop module not only addressed many of the practical challenges associated with paper-based peer assessments, but also provided a range of additional options for enhancing validity and reliability of peer assessments that would not be possible with paper-based systems.
- Full Text: false
- Date Issued: 2012
Petrographic and geochemical characterisation of the hangingwall and the footwall rocks (the Dipeta and R.A.T. stratigraphic units) to the Kinsevere and Nambulwa copper ore deposits of the Lufilian Arc, southern Democratic Republic of Congo
- Authors: Nkulu, Robert Kankomba
- Date: 2020
- Subjects: Petrogenesis -- Congo (Democratic Republic) , Analytical geochemistry -- Congo (Democratic Republic) , Copper ores -- Congo (Democratic Republic) , Ore deposits -- Congo (Democratic Republic) , Katangan Sequence , Geological mapping -- Congo (Democratic Republic) , Central African Copperbelt (Congo and Zambia) , Lufilian Arc , Neoproterozoic Katangan R.A.T. (Roches Argilo Talqueuse) Subgroup , Dipeta Subgroup
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/142772 , vital:38115
- Description: The Kinsevere and Nambulwa copper deposits in the Democratic Republic of Congo (D.R.C.) are set in the eastern side of the Neoproterozoic Katanga Supergroup, forming the Lufilian Arc, resulting from a cratonic collision between the Congo and the Kalahari Cratons (ca.620-570_Ma). The Katanga Supergroup was deposited in an extensional rift setting with a sedimentary thickness succession ranging between 7 to 10 km, sub-divided into: − the Roan, the Nguba and the Kundelungu Groups. The stratigraphic column of the Roan Group consists of the R.A.T. (Roche Argilo Talqueuse), the Mines, the Dipeta and the Mwashya Subgroups. Three major deformation phases have been described characterised by complex multiphase tectonics related to a curved superposition of folded, thrust and sheared blocks. The rocks of the R.A.T., Mines and Dipeta Subgroups are recognised as blocks that occur within a stratiform to discordant and diapiritic megabreccia. The blocks were rafted upward with salt tectonics, resulting in the juxtaposition with the hangingwall and the footwall terranes. Therefore, in that context it has been found that the Dipeta may appear overlying the R.A.T. Subgroup through the unconformity decollement surface of heterogeneous breccia. The petrographic observations made of the R.A.T. and Dipeta samples indicates in both units the presence of detrital quartz and feldspar that have been altered and replaced by sericite and muscovite minerals. Gypsum is intimately associated with magnesite, showing an evaporitic environment domain, while magnesite is common as alteration phase both in the R.A.T. and Dipeta Subgroups. Pyrophyllite has been observed in the Dipeta, resulting from reaction of silica with the Kaolinite at low temperature. Accessory detrital minerals include zircon, as well as xenotime intergrown with altered Fe-Ti-oxide hematite, forming complex textures with disseminated Ti-oxides both in R.A.T. and Dipeta units. Major and trace element geochemistry indicates that the Dipeta is more dolomitic and magnesite while the R.A.T. is clay-rich. The Ti2O value of Dipeta and R.A.T samples is relatively low, ranging between 0.36 and 0.69 wt.% respectively, which suggest highly evolved felsic material in the protolith. This is consistent with interpretation based on the Al2O3/TiO2 ratio, which ranges between 18 and 23 for the R.A.T. and Dipeta respectively, indicating an intermediate to felsic granitoids as the protolith of R.A.T. and Dipeta siltstones. The Ti/Zr ratio of R.A.T. and Dipeta samples of less than 10, while, the higher La/Sc ratio of between 2.6 and 5.5 (for the R.A.T. and Dipeta respectively) indicate that both the R.A.T. and Dipeta are active continental and passive margin tectonic setting. Based on the geochemical variation with depth across the R.A.T. and Dipeta and their contact zone, a geochemical fingerprinting suggests that the ratio TiO2/Al2O3 appears to be useful and could be considered as a stratigraphic geochemical maker able to discriminate the R.A.T. and the Dipeta Subgroups during the geological mapping.
- Full Text:
- Date Issued: 2020
- Authors: Nkulu, Robert Kankomba
- Date: 2020
- Subjects: Petrogenesis -- Congo (Democratic Republic) , Analytical geochemistry -- Congo (Democratic Republic) , Copper ores -- Congo (Democratic Republic) , Ore deposits -- Congo (Democratic Republic) , Katangan Sequence , Geological mapping -- Congo (Democratic Republic) , Central African Copperbelt (Congo and Zambia) , Lufilian Arc , Neoproterozoic Katangan R.A.T. (Roches Argilo Talqueuse) Subgroup , Dipeta Subgroup
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/142772 , vital:38115
- Description: The Kinsevere and Nambulwa copper deposits in the Democratic Republic of Congo (D.R.C.) are set in the eastern side of the Neoproterozoic Katanga Supergroup, forming the Lufilian Arc, resulting from a cratonic collision between the Congo and the Kalahari Cratons (ca.620-570_Ma). The Katanga Supergroup was deposited in an extensional rift setting with a sedimentary thickness succession ranging between 7 to 10 km, sub-divided into: − the Roan, the Nguba and the Kundelungu Groups. The stratigraphic column of the Roan Group consists of the R.A.T. (Roche Argilo Talqueuse), the Mines, the Dipeta and the Mwashya Subgroups. Three major deformation phases have been described characterised by complex multiphase tectonics related to a curved superposition of folded, thrust and sheared blocks. The rocks of the R.A.T., Mines and Dipeta Subgroups are recognised as blocks that occur within a stratiform to discordant and diapiritic megabreccia. The blocks were rafted upward with salt tectonics, resulting in the juxtaposition with the hangingwall and the footwall terranes. Therefore, in that context it has been found that the Dipeta may appear overlying the R.A.T. Subgroup through the unconformity decollement surface of heterogeneous breccia. The petrographic observations made of the R.A.T. and Dipeta samples indicates in both units the presence of detrital quartz and feldspar that have been altered and replaced by sericite and muscovite minerals. Gypsum is intimately associated with magnesite, showing an evaporitic environment domain, while magnesite is common as alteration phase both in the R.A.T. and Dipeta Subgroups. Pyrophyllite has been observed in the Dipeta, resulting from reaction of silica with the Kaolinite at low temperature. Accessory detrital minerals include zircon, as well as xenotime intergrown with altered Fe-Ti-oxide hematite, forming complex textures with disseminated Ti-oxides both in R.A.T. and Dipeta units. Major and trace element geochemistry indicates that the Dipeta is more dolomitic and magnesite while the R.A.T. is clay-rich. The Ti2O value of Dipeta and R.A.T samples is relatively low, ranging between 0.36 and 0.69 wt.% respectively, which suggest highly evolved felsic material in the protolith. This is consistent with interpretation based on the Al2O3/TiO2 ratio, which ranges between 18 and 23 for the R.A.T. and Dipeta respectively, indicating an intermediate to felsic granitoids as the protolith of R.A.T. and Dipeta siltstones. The Ti/Zr ratio of R.A.T. and Dipeta samples of less than 10, while, the higher La/Sc ratio of between 2.6 and 5.5 (for the R.A.T. and Dipeta respectively) indicate that both the R.A.T. and Dipeta are active continental and passive margin tectonic setting. Based on the geochemical variation with depth across the R.A.T. and Dipeta and their contact zone, a geochemical fingerprinting suggests that the ratio TiO2/Al2O3 appears to be useful and could be considered as a stratigraphic geochemical maker able to discriminate the R.A.T. and the Dipeta Subgroups during the geological mapping.
- Full Text:
- Date Issued: 2020
Predicting reintroduction outcomes: assessing the feasibility of reintroducing African wild dog to a small protected area
- Authors: Vogel, John Thomas
- Date: 2018
- Subjects: African wild dog , Wild dogs -- South Africa Wild dogs -- Conservation -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/36464 , vital:33947
- Description: Large mammalian carnivores have experienced significant contractions in population sizes and geographical ranges. The conservation of large carnivores is crucially important, particularly due to their vulnerability to extinction and their functional significance and ability to structure ecosystems. Due to an expanding human footprint, large carnivores are increasingly subject to modified and spatially constrained habitats. A growing debate exists as to how to conserve and coexist with large carnivores in an anthropogenically induced environment. Reintroduction, as a conservation tool to restore locally extirpated large carnivores to portions of their former ranges is increasingly being applied. However, in South Africa, habitat to support large carnivores remain small and non-contiguous. Food is a fundamental ecological requirement to sustain reintroduced large carnivores. Therefore, an understanding of large predator foraging patterns can be informative in the context of how the predator species influences and utilises a novel ecosystem. We investigated the foraging behaviour of reintroduced African wild dog (Lycaon pictus) at five small protected areas in KwaZulu-Natal, South Africa. Wild dog utilised 16 prey species, albeit they primarily used nyala (Tragelaphus angasii) and impala (Aepyceros melampus) which collectively form 75 % of their diet. Only nyala was significantly preferred, suggesting that this prey species is used in greater proportion to their abundance. As wild dogs are social cooperative hunters, we tested whether wild dog pack size was correlated to prey mass selection. There was no evidence to suggest that larger packs use larger prey. However, the mean wild dog pack size in our sample sites, was relatively smaller than those encountered elsewhere. Furthermore, wild dog have been shown to modify their hunting behaviour in the presence of wildlife-proof fencing, by using fences to aid in the capture of larger prey species than would innately occur. We compared the prey mass of wild dog kills in relation to proximity of these hard boundaries. Despite the affinity towards kills occurring within 200 m of fences, the upward bias caused by fences on prey mass selection was inconsistent across sample sites. The relatively small size of wild dogs makes them particularly vulnerable to competition. As the energetic output of wild dog is high, interspecific competition can increase foraging costs. The reintroduction of large carnivores to small artificially induced systems may be a contentious issue as resources available to support large carnivores are expected to be relatively more finite. We compared both the potential inter- and intraspecific dietary niche dimensions of an intact large carnivore guild in context of a wild dog reintroduction. We determined cheetah (Acinonyx jubatus), leopard (Panthera pardus), and lion (Panthera leo) prey composition, diet breadth, overlap, prey preference and predicted the density of an intact large carnivore guild in a novel landscape. Further, we compared the foraging behaviour of these large carnivores to that of wild dog. Our findings suggest that large African carnivores in small protected areas are subject to a considerable dietary niche overlap. Wild dog and cheetah, particularly reproductive females with dependent offspring, displayed the greatest potential for dietary overlap and subsequent competition. Leopard and lion at the population species level exhibited greater degrees of foraging plasticity. Lion displayed a contrasting prey species preference to sympatric predators as they selected for prey items frequently avoided by cheetah, leopard and wild dog. The proposed wild dog reintroduction site is expected to sustain seven wild dog based on the availability of preferred prey biomass. However, the reintroduction of wild dog to the small protected area is expected to have negative lateral trophic influences on other species of conservation concern. This should be of vital importance to management of the protected area. As the influence of competition in food-web and population dynamics, particularly in resource poor environments may be profound, our research highlights the need to assess the influence of competitive forces in structuring and restoring large predators to portions of their historical range.
- Full Text:
- Date Issued: 2018
- Authors: Vogel, John Thomas
- Date: 2018
- Subjects: African wild dog , Wild dogs -- South Africa Wild dogs -- Conservation -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/36464 , vital:33947
- Description: Large mammalian carnivores have experienced significant contractions in population sizes and geographical ranges. The conservation of large carnivores is crucially important, particularly due to their vulnerability to extinction and their functional significance and ability to structure ecosystems. Due to an expanding human footprint, large carnivores are increasingly subject to modified and spatially constrained habitats. A growing debate exists as to how to conserve and coexist with large carnivores in an anthropogenically induced environment. Reintroduction, as a conservation tool to restore locally extirpated large carnivores to portions of their former ranges is increasingly being applied. However, in South Africa, habitat to support large carnivores remain small and non-contiguous. Food is a fundamental ecological requirement to sustain reintroduced large carnivores. Therefore, an understanding of large predator foraging patterns can be informative in the context of how the predator species influences and utilises a novel ecosystem. We investigated the foraging behaviour of reintroduced African wild dog (Lycaon pictus) at five small protected areas in KwaZulu-Natal, South Africa. Wild dog utilised 16 prey species, albeit they primarily used nyala (Tragelaphus angasii) and impala (Aepyceros melampus) which collectively form 75 % of their diet. Only nyala was significantly preferred, suggesting that this prey species is used in greater proportion to their abundance. As wild dogs are social cooperative hunters, we tested whether wild dog pack size was correlated to prey mass selection. There was no evidence to suggest that larger packs use larger prey. However, the mean wild dog pack size in our sample sites, was relatively smaller than those encountered elsewhere. Furthermore, wild dog have been shown to modify their hunting behaviour in the presence of wildlife-proof fencing, by using fences to aid in the capture of larger prey species than would innately occur. We compared the prey mass of wild dog kills in relation to proximity of these hard boundaries. Despite the affinity towards kills occurring within 200 m of fences, the upward bias caused by fences on prey mass selection was inconsistent across sample sites. The relatively small size of wild dogs makes them particularly vulnerable to competition. As the energetic output of wild dog is high, interspecific competition can increase foraging costs. The reintroduction of large carnivores to small artificially induced systems may be a contentious issue as resources available to support large carnivores are expected to be relatively more finite. We compared both the potential inter- and intraspecific dietary niche dimensions of an intact large carnivore guild in context of a wild dog reintroduction. We determined cheetah (Acinonyx jubatus), leopard (Panthera pardus), and lion (Panthera leo) prey composition, diet breadth, overlap, prey preference and predicted the density of an intact large carnivore guild in a novel landscape. Further, we compared the foraging behaviour of these large carnivores to that of wild dog. Our findings suggest that large African carnivores in small protected areas are subject to a considerable dietary niche overlap. Wild dog and cheetah, particularly reproductive females with dependent offspring, displayed the greatest potential for dietary overlap and subsequent competition. Leopard and lion at the population species level exhibited greater degrees of foraging plasticity. Lion displayed a contrasting prey species preference to sympatric predators as they selected for prey items frequently avoided by cheetah, leopard and wild dog. The proposed wild dog reintroduction site is expected to sustain seven wild dog based on the availability of preferred prey biomass. However, the reintroduction of wild dog to the small protected area is expected to have negative lateral trophic influences on other species of conservation concern. This should be of vital importance to management of the protected area. As the influence of competition in food-web and population dynamics, particularly in resource poor environments may be profound, our research highlights the need to assess the influence of competitive forces in structuring and restoring large predators to portions of their historical range.
- Full Text:
- Date Issued: 2018
Synthesis and characterisation of lanthanide complexes with nitrogen- and oxygen-donor ligands
- Authors: Madanhire, Tatenda
- Date: 2016
- Subjects: Rare earth metals
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/13127 , vital:27154
- Description: The reactions of Ln(NO3)3∙6H2O (Ln = Pr, Nd or Er) with the potentially tridentate O,N,O chelating ligand 2,6-pyridinedimethanol (H2pydm) were investigated, and complexes with the formula, [Ln(H2pydm)2(NO3)2](NO3) (Ln = Pr or Nd) and [Er(H2pydm)3](NO3)3 were isolated. The ten-coordinate Pr(III) and Nd(III) compounds crystallise in the triclinic space group P-1 while the nine-coordinate Er(III) complex crystallises in the monoclinic system (P21/n). The reaction of PrCl3∙6H2O with H2pydm yielded the compound, [Pr(H2pydm)3](Cl)3, that crystallises in the monoclinic system, space group P21/c with α = 90, β = 98.680(1) and γ = 90°. The nine-coordinate Pr(III) ion is bound to three H2pydm ligands, with bond distances Pr-O 2.455(2)-2.478(2) Å and Pr-N 2.6355(19)-2.64(2) Å. X-ray crystal structures of all the H2pydm complexes reveal that the ligand coordinates tridentately, via the pyridyl nitrogen atom and the two hydroxyl oxygen atoms. The electronic absorption spectra of complexes show 4f-4f transitions. Rare-earth complexes, [Ln(H2L1)2(NO3)3] [Ln = Gd, Ho or Nd], were also prepared from a Schiff base. The X-ray single-crystal diffraction studies and SHAPE analyses of the Gd(III) and Ho(III) complexes shows that the complexes are ten-coordinate and exhibit distorted tetradecahedron geometries. With proton migration occurring from the phenol group to the imine function, complexation of the lanthanides to the ligand gives the ligand a zwitterionic phenoxo-iminium form. A phenolate oxygen-bridged dinuclear complex, [Ce2(H2L1)(ovan)3(NO3)3], has been obtained by reacting Ce(NO3)3∙6H2O with an o-vanillin derived Schiff base ligand, 2-((E)-(1-hydroxy-2-methylpropan-2-ylimino)methyl)-6-methoxyphenol (H2L1). Hydrolysis of the Schiff base occurred to yield o-vanillin, which bridged two cerium atoms with the Ce∙∙∙Ce distance equal to 3.823 Å. The Ce(III) ions are both tencoordinate, but have different coordination environments, showing tetradecahedron and staggered dodecahedron geometries, respectively. The reaction of salicylaldehyde-N(4)-diethylthiosemicarbazone (H2L2) in the presence of hydrated Ln(III) nitrates led to the isolation of two novel compounds: (E)-2[(ortho-hydroxy)benzylidene]-2-(thiomethyl)-thionohydrazide (1) and bis[2,3-diaza4-(2-hydroxyphenyl)-1-thiomethyl-buta-1,3-diene]disulfide. The latter is a dimer of the former. For this asymmetric Schiff base, 1 and the symmetric disulfide, classical hydrogen bonds of the O–H∙∙∙N as well as N–H∙∙∙S (for 1) type are apparent next to C–H∙∙∙O contacts. 4-(4-Bromophenyl)-1-(propan-2-ylidene)thiosemicarbazide was also prepared upon reacting 4-(4-bromophenyl)-3-thiosemicarbazide with acetone in the presence of ethanol and La(NO3)3∙6H2O. The C=S bond length was found to be 1.6686(16) Å which is in good agreement with other thioketones whose metrical parameters have been deposited with the Cambridge Structural Database. Classical hydrogen bonds of the N–H∙∙∙N and the N–H∙∙∙Br type are observed next to C–H∙∙∙S contacts. All synthesised compounds were characterised by microanalyses, single-crystal X-ray diffraction (except for [Nd(H2L1)2(NO3)3]), 1H NMR and IR spectroscopy.
- Full Text:
- Date Issued: 2016
- Authors: Madanhire, Tatenda
- Date: 2016
- Subjects: Rare earth metals
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/13127 , vital:27154
- Description: The reactions of Ln(NO3)3∙6H2O (Ln = Pr, Nd or Er) with the potentially tridentate O,N,O chelating ligand 2,6-pyridinedimethanol (H2pydm) were investigated, and complexes with the formula, [Ln(H2pydm)2(NO3)2](NO3) (Ln = Pr or Nd) and [Er(H2pydm)3](NO3)3 were isolated. The ten-coordinate Pr(III) and Nd(III) compounds crystallise in the triclinic space group P-1 while the nine-coordinate Er(III) complex crystallises in the monoclinic system (P21/n). The reaction of PrCl3∙6H2O with H2pydm yielded the compound, [Pr(H2pydm)3](Cl)3, that crystallises in the monoclinic system, space group P21/c with α = 90, β = 98.680(1) and γ = 90°. The nine-coordinate Pr(III) ion is bound to three H2pydm ligands, with bond distances Pr-O 2.455(2)-2.478(2) Å and Pr-N 2.6355(19)-2.64(2) Å. X-ray crystal structures of all the H2pydm complexes reveal that the ligand coordinates tridentately, via the pyridyl nitrogen atom and the two hydroxyl oxygen atoms. The electronic absorption spectra of complexes show 4f-4f transitions. Rare-earth complexes, [Ln(H2L1)2(NO3)3] [Ln = Gd, Ho or Nd], were also prepared from a Schiff base. The X-ray single-crystal diffraction studies and SHAPE analyses of the Gd(III) and Ho(III) complexes shows that the complexes are ten-coordinate and exhibit distorted tetradecahedron geometries. With proton migration occurring from the phenol group to the imine function, complexation of the lanthanides to the ligand gives the ligand a zwitterionic phenoxo-iminium form. A phenolate oxygen-bridged dinuclear complex, [Ce2(H2L1)(ovan)3(NO3)3], has been obtained by reacting Ce(NO3)3∙6H2O with an o-vanillin derived Schiff base ligand, 2-((E)-(1-hydroxy-2-methylpropan-2-ylimino)methyl)-6-methoxyphenol (H2L1). Hydrolysis of the Schiff base occurred to yield o-vanillin, which bridged two cerium atoms with the Ce∙∙∙Ce distance equal to 3.823 Å. The Ce(III) ions are both tencoordinate, but have different coordination environments, showing tetradecahedron and staggered dodecahedron geometries, respectively. The reaction of salicylaldehyde-N(4)-diethylthiosemicarbazone (H2L2) in the presence of hydrated Ln(III) nitrates led to the isolation of two novel compounds: (E)-2[(ortho-hydroxy)benzylidene]-2-(thiomethyl)-thionohydrazide (1) and bis[2,3-diaza4-(2-hydroxyphenyl)-1-thiomethyl-buta-1,3-diene]disulfide. The latter is a dimer of the former. For this asymmetric Schiff base, 1 and the symmetric disulfide, classical hydrogen bonds of the O–H∙∙∙N as well as N–H∙∙∙S (for 1) type are apparent next to C–H∙∙∙O contacts. 4-(4-Bromophenyl)-1-(propan-2-ylidene)thiosemicarbazide was also prepared upon reacting 4-(4-bromophenyl)-3-thiosemicarbazide with acetone in the presence of ethanol and La(NO3)3∙6H2O. The C=S bond length was found to be 1.6686(16) Å which is in good agreement with other thioketones whose metrical parameters have been deposited with the Cambridge Structural Database. Classical hydrogen bonds of the N–H∙∙∙N and the N–H∙∙∙Br type are observed next to C–H∙∙∙S contacts. All synthesised compounds were characterised by microanalyses, single-crystal X-ray diffraction (except for [Nd(H2L1)2(NO3)3]), 1H NMR and IR spectroscopy.
- Full Text:
- Date Issued: 2016
Rhodes University Research Report 2013
- Rhodes University, Roberts, Jaine, Mantolo, Thumeka, Jacob, Patricia, Macgregor, Jill, Dore, Sally
- Authors: Rhodes University , Roberts, Jaine , Mantolo, Thumeka , Jacob, Patricia , Macgregor, Jill , Dore, Sally
- Date: 2013
- Language: English
- Type: Text
- Identifier: http://hdl.handle.net/10962/59330 , vital:27549
- Description: From Foreword by Dr Saleem Badat: Rhodes University has positioned itself as a research university that, alongside excellence in undergraduate teaching, also takes scholarship seriously. This has strongly shaped the intellectual identity of the university and, today, research income and expenditure are significant components of the university’s finances. Rhodes University values the scholar-teacher model of combining research with teaching and learning, and other scholarly activities. This has a strong influence on the quality of intellectual endeavour at the University, and is critical in advancing the University’s pursuit of a strong postgraduate trajectory. This is an opportunity to briefly reflect on research at Rhodes over the eight years of my Vice-Chancellorship. It is gratifying to see that scholarship and publishing has continued to blossom at Rhodes, and has also occurred over a wider academic base, and that there has also been increased enrolments of postgraduates, as part of overall University strategy. Postgraduate enrolments increased from 24% (1 397) in 2006 to 30% (2 302) in 2013, with considerable increases in the numbers of Masters and Doctoral students. Between 2006 and 2013, Honours and Postgraduate Diploma graduations increased from 453 to 719, Masters graduations increased by 73% (from 171 to 296) and Doctoral graduations by 70% (from 46 to 78). Concomitantly, there was an increase in the numbers of black and women PhD graduates. The number of Postdoctoral Fellows at Rhodes rose from 19 in 2007 to 68 in 2013, an increase of 258%. , A publication of the Rhodes University Research Office, compiled and edited by Jaine Roberts, Thumeka Mantolo, Patricia Jacob and Jill Macgregor. Design and Layout: Sally Dore
- Full Text:
- Date Issued: 2013
- Authors: Rhodes University , Roberts, Jaine , Mantolo, Thumeka , Jacob, Patricia , Macgregor, Jill , Dore, Sally
- Date: 2013
- Language: English
- Type: Text
- Identifier: http://hdl.handle.net/10962/59330 , vital:27549
- Description: From Foreword by Dr Saleem Badat: Rhodes University has positioned itself as a research university that, alongside excellence in undergraduate teaching, also takes scholarship seriously. This has strongly shaped the intellectual identity of the university and, today, research income and expenditure are significant components of the university’s finances. Rhodes University values the scholar-teacher model of combining research with teaching and learning, and other scholarly activities. This has a strong influence on the quality of intellectual endeavour at the University, and is critical in advancing the University’s pursuit of a strong postgraduate trajectory. This is an opportunity to briefly reflect on research at Rhodes over the eight years of my Vice-Chancellorship. It is gratifying to see that scholarship and publishing has continued to blossom at Rhodes, and has also occurred over a wider academic base, and that there has also been increased enrolments of postgraduates, as part of overall University strategy. Postgraduate enrolments increased from 24% (1 397) in 2006 to 30% (2 302) in 2013, with considerable increases in the numbers of Masters and Doctoral students. Between 2006 and 2013, Honours and Postgraduate Diploma graduations increased from 453 to 719, Masters graduations increased by 73% (from 171 to 296) and Doctoral graduations by 70% (from 46 to 78). Concomitantly, there was an increase in the numbers of black and women PhD graduates. The number of Postdoctoral Fellows at Rhodes rose from 19 in 2007 to 68 in 2013, an increase of 258%. , A publication of the Rhodes University Research Office, compiled and edited by Jaine Roberts, Thumeka Mantolo, Patricia Jacob and Jill Macgregor. Design and Layout: Sally Dore
- Full Text:
- Date Issued: 2013
A study of a class of invariant optimal control problems on the Euclidean group SE(2)
- Authors: Adams, Ross Montague
- Date: 2011
- Subjects: Matrix groups Lie groups Extremal problems (Mathematics) Maximum principles (Mathematics) Hamilton-Jacobi equations Lyapunov stability
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5420 , http://hdl.handle.net/10962/d1006060
- Description: The aim of this thesis is to study a class of left-invariant optimal control problems on the matrix Lie group SE(2). We classify, under detached feedback equivalence, all controllable (left-invariant) control affine systems on SE(2). This result produces six types of control affine systems on SE(2). Hence, we study six associated left-invariant optimal control problems on SE(2). A left-invariant optimal control problem consists of minimizing a cost functional over the trajectory-control pairs of a left-invariant control system subject to appropriate boundary conditions. Each control problem is lifted from SE(2) to T*SE(2) ≅ SE(2) x se (2)*and then reduced to a problem on se (2)*. The maximum principle is used to obtain the optimal control and Hamiltonian corresponding to the normal extremals. Then we derive the (reduced) extremal equations on se (2)*. These equations are explicitly integrated by trigonometric and Jacobi elliptic functions. Finally, we fully classify, under Lyapunov stability, the equilibrium states of the normal extremal equations for each of the six types under consideration.
- Full Text:
- Date Issued: 2011
- Authors: Adams, Ross Montague
- Date: 2011
- Subjects: Matrix groups Lie groups Extremal problems (Mathematics) Maximum principles (Mathematics) Hamilton-Jacobi equations Lyapunov stability
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5420 , http://hdl.handle.net/10962/d1006060
- Description: The aim of this thesis is to study a class of left-invariant optimal control problems on the matrix Lie group SE(2). We classify, under detached feedback equivalence, all controllable (left-invariant) control affine systems on SE(2). This result produces six types of control affine systems on SE(2). Hence, we study six associated left-invariant optimal control problems on SE(2). A left-invariant optimal control problem consists of minimizing a cost functional over the trajectory-control pairs of a left-invariant control system subject to appropriate boundary conditions. Each control problem is lifted from SE(2) to T*SE(2) ≅ SE(2) x se (2)*and then reduced to a problem on se (2)*. The maximum principle is used to obtain the optimal control and Hamiltonian corresponding to the normal extremals. Then we derive the (reduced) extremal equations on se (2)*. These equations are explicitly integrated by trigonometric and Jacobi elliptic functions. Finally, we fully classify, under Lyapunov stability, the equilibrium states of the normal extremal equations for each of the six types under consideration.
- Full Text:
- Date Issued: 2011
An investigation of parameter relationships in a high-speed digital multimedia environment
- Authors: Chigwamba, Nyasha
- Date: 2014
- Subjects: Multimedia communications , Digital communications , Local area networks (Computer networks) , Computer network architectures , Computer network protocols , Computer sound processing , Sound -- Recording and reproducing -- Digital techniques
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4725 , http://hdl.handle.net/10962/d1021153
- Description: With the rapid adoption of multimedia network technologies, a number of companies and standards bodies are introducing technologies that enhance user experience in networked multimedia environments. These technologies focus on device discovery, connection management, control, and monitoring. This study focused on control and monitoring. Multimedia networks make it possible for devices that are part of the same network to reside in different physical locations. These devices contain parameters that are used to control particular features, such as speaker volume, bass, amplifier gain, and video resolution. It is often necessary for changes in one parameter to affect other parameters, such as a synchronised change between volume and bass parameters, or collective control of multiple parameters. Thus, relationships are required between the parameters. In addition, some devices contain parameters, such as voltage, temperature, and audio level, that require constant monitoring to enable corrective action when thresholds are exceeded. Therefore, a mechanism for monitoring networked devices is required. This thesis proposes relationships that are essential for the proper functioning of a multimedia network and that should, therefore, be incorporated in standard form into a protocol, such that all devices can depend on them. Implementation mechanisms for these relationships were created. Parameter grouping and monitoring capabilities within mixing console implementations and existing control protocols were reviewed. A number of requirements for parameter grouping and monitoring were derived from this review. These requirements include a formal classification of relationship types, the ability to create relationships between parameters with different underlying value units, the ability to create relationships between parameters residing on different devices on a network, and the use of an event-driven mechanism for parameter monitoring. These requirements were the criteria used to govern the implementation mechanisms that were created as part of this study. Parameter grouping and monitoring mechanisms were implemented for the XFN protocol. The mechanisms implemented fulfil the requirements derived from the review of capabilities of mixing consoles and existing control protocols. The formal classification of relationship types was implemented within XFN parameters using lists that keep track of the relationships between each XFN parameter and other XFN parameters that reside on the same device or on other devices on the network. A common value unit, known as the global unit, was defined for use as the value format within value update messages between XFN parameters that have relationships. Mapping tables were used to translate the global unit values to application-specific (universal) units, such as decibels (dB). A mechanism for bulk parameter retrieval within the XFN protocol was augmented to produce an event-driven mechanism for parameter monitoring. These implementation mechanisms were applied to an XFN-protocol-compliant graphical control application to demonstrate their usage within an end user context. At the time of this study, the XFN protocol was undergoing standardisation within the Audio Engineering Society. The AES-64 standard has now been approved. Most of the implementation mechanisms resulting from this study have been incorporated into this standard.
- Full Text:
- Date Issued: 2014
- Authors: Chigwamba, Nyasha
- Date: 2014
- Subjects: Multimedia communications , Digital communications , Local area networks (Computer networks) , Computer network architectures , Computer network protocols , Computer sound processing , Sound -- Recording and reproducing -- Digital techniques
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4725 , http://hdl.handle.net/10962/d1021153
- Description: With the rapid adoption of multimedia network technologies, a number of companies and standards bodies are introducing technologies that enhance user experience in networked multimedia environments. These technologies focus on device discovery, connection management, control, and monitoring. This study focused on control and monitoring. Multimedia networks make it possible for devices that are part of the same network to reside in different physical locations. These devices contain parameters that are used to control particular features, such as speaker volume, bass, amplifier gain, and video resolution. It is often necessary for changes in one parameter to affect other parameters, such as a synchronised change between volume and bass parameters, or collective control of multiple parameters. Thus, relationships are required between the parameters. In addition, some devices contain parameters, such as voltage, temperature, and audio level, that require constant monitoring to enable corrective action when thresholds are exceeded. Therefore, a mechanism for monitoring networked devices is required. This thesis proposes relationships that are essential for the proper functioning of a multimedia network and that should, therefore, be incorporated in standard form into a protocol, such that all devices can depend on them. Implementation mechanisms for these relationships were created. Parameter grouping and monitoring capabilities within mixing console implementations and existing control protocols were reviewed. A number of requirements for parameter grouping and monitoring were derived from this review. These requirements include a formal classification of relationship types, the ability to create relationships between parameters with different underlying value units, the ability to create relationships between parameters residing on different devices on a network, and the use of an event-driven mechanism for parameter monitoring. These requirements were the criteria used to govern the implementation mechanisms that were created as part of this study. Parameter grouping and monitoring mechanisms were implemented for the XFN protocol. The mechanisms implemented fulfil the requirements derived from the review of capabilities of mixing consoles and existing control protocols. The formal classification of relationship types was implemented within XFN parameters using lists that keep track of the relationships between each XFN parameter and other XFN parameters that reside on the same device or on other devices on the network. A common value unit, known as the global unit, was defined for use as the value format within value update messages between XFN parameters that have relationships. Mapping tables were used to translate the global unit values to application-specific (universal) units, such as decibels (dB). A mechanism for bulk parameter retrieval within the XFN protocol was augmented to produce an event-driven mechanism for parameter monitoring. These implementation mechanisms were applied to an XFN-protocol-compliant graphical control application to demonstrate their usage within an end user context. At the time of this study, the XFN protocol was undergoing standardisation within the Audio Engineering Society. The AES-64 standard has now been approved. Most of the implementation mechanisms resulting from this study have been incorporated into this standard.
- Full Text:
- Date Issued: 2014
An assessment of the performance appraisal system utilised for junior and middle level management within the South African National Defence Force
- Authors: Terblanche, Graham Martin
- Date: 2004
- Subjects: Middle managers -- Rating of -- South Africa , South Africa. National Defence Force Officials and employees Rating of
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:10884 , http://hdl.handle.net/10948/148 , Middle managers -- Rating of -- South Africa , South Africa. National Defence Force Officials and employees Rating of
- Description: The research problem of this study was to assess the extent to which the appraisal system for junior and middle level managers in the South African National Defence Force (SANDF) met the requirements and guidelines for performance appraisal as stipulated in the literature. To achieve this objective, the following procedure was followed: · A survey of existing literature, related to performance appraisal, was conducted. The literature study focused on the requirements for an effective performance appraisal system, appraisal methods and appraisal errors. Attention was also focused on who should take responsibility for performance appraisal and the importance of regularly evaluating the performance appraisal system to meet the demands of a changing environment. The second part of the literature study dealt with the guidelines for establishing an effective appraisal system as well as performance management processes and cycles that are critical for the effectiveness of an appraisal system. The theoretical study formed the basis for the development of a survey questionnaire to establish the extent to which junior and middle level managers in the SANDF agreed with the theoretical guidelines. The survey was administered to a randomly selected group of junior and middle level managers who were representative of the South African Army, Airforce and Medical Services. The empirical results indicated that there was concurrence with many of the guidelines in the literature, but that there were areas that could be improved. It became evident that many respondents felt that the current system was not entirely fair and was not adapted to meet the needs of the integrated SANDF. Specifically, results indicated that the system should be re-evaluated to eliminate bias and to enhance the development of clear standards, both on a quantitative and qualitative level. It became clear that training and communication were important to the successful development and utilisation of a performance appraisal system. An effective performance appraisal system that is integrated with the overall performance management system of an organisation will enhance productivity, satisfaction and the attainment of goals.
- Full Text:
- Date Issued: 2004
- Authors: Terblanche, Graham Martin
- Date: 2004
- Subjects: Middle managers -- Rating of -- South Africa , South Africa. National Defence Force Officials and employees Rating of
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:10884 , http://hdl.handle.net/10948/148 , Middle managers -- Rating of -- South Africa , South Africa. National Defence Force Officials and employees Rating of
- Description: The research problem of this study was to assess the extent to which the appraisal system for junior and middle level managers in the South African National Defence Force (SANDF) met the requirements and guidelines for performance appraisal as stipulated in the literature. To achieve this objective, the following procedure was followed: · A survey of existing literature, related to performance appraisal, was conducted. The literature study focused on the requirements for an effective performance appraisal system, appraisal methods and appraisal errors. Attention was also focused on who should take responsibility for performance appraisal and the importance of regularly evaluating the performance appraisal system to meet the demands of a changing environment. The second part of the literature study dealt with the guidelines for establishing an effective appraisal system as well as performance management processes and cycles that are critical for the effectiveness of an appraisal system. The theoretical study formed the basis for the development of a survey questionnaire to establish the extent to which junior and middle level managers in the SANDF agreed with the theoretical guidelines. The survey was administered to a randomly selected group of junior and middle level managers who were representative of the South African Army, Airforce and Medical Services. The empirical results indicated that there was concurrence with many of the guidelines in the literature, but that there were areas that could be improved. It became evident that many respondents felt that the current system was not entirely fair and was not adapted to meet the needs of the integrated SANDF. Specifically, results indicated that the system should be re-evaluated to eliminate bias and to enhance the development of clear standards, both on a quantitative and qualitative level. It became clear that training and communication were important to the successful development and utilisation of a performance appraisal system. An effective performance appraisal system that is integrated with the overall performance management system of an organisation will enhance productivity, satisfaction and the attainment of goals.
- Full Text:
- Date Issued: 2004
Fungal remediation of winery and distillery wastewaters using Trametes pubescens MB 89 and the enhanced production of a high-value enzyme therein
- Authors: Strong, Peter James
- Date: 2008
- Subjects: Fungal remediation Distilleries -- Waste disposal Wine and wine making -- Waste disposal Bioremediation Laccase Enzymes -- Biotechnology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3932 , http://hdl.handle.net/10962/d1003991
- Description: In this study white-rot fungi were investigated for their efficiency at distillery wastewater remediation and the production of laccase as a valuable by-product. Distillery wastewaters are high in organic load and low in pH. The presence of phenolic compounds can lead to extremely colour-rich wastewaters and can be toxic to microorganisms. The presence of the inorganic ions may also affect biological treatment. White-rot fungi are unique among eukaryotic or prokaryotic microbes in possessing powerful oxidative enzyme systems that can degrade lignin to carbon dioxide. These ligninolytic enzymes, such as lignin peroxidase, manganese peroxidase and laccase, are capable of degrading a vast range of toxic, recalcitrant environmental pollutants and this makes the white-rot fungi strong candidates for the bioremediation of polluted soils and waters. The laccase enzyme alone has shown remediation potential in wastewaters such as beer production effluent, olive mill wastewater, alcohol distillery wastes, dye-containing wastewaters from the textile industry as well as wastewaters from the paper and pulp industry. It has been shown to be capable of remediating soils and waters polluted with chlorinated phenolic compounds, polyaromatic hydrocarbons, nitrosubstituted compounds and fungicides, herbicides and insecticides.
- Full Text:
- Date Issued: 2008
- Authors: Strong, Peter James
- Date: 2008
- Subjects: Fungal remediation Distilleries -- Waste disposal Wine and wine making -- Waste disposal Bioremediation Laccase Enzymes -- Biotechnology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3932 , http://hdl.handle.net/10962/d1003991
- Description: In this study white-rot fungi were investigated for their efficiency at distillery wastewater remediation and the production of laccase as a valuable by-product. Distillery wastewaters are high in organic load and low in pH. The presence of phenolic compounds can lead to extremely colour-rich wastewaters and can be toxic to microorganisms. The presence of the inorganic ions may also affect biological treatment. White-rot fungi are unique among eukaryotic or prokaryotic microbes in possessing powerful oxidative enzyme systems that can degrade lignin to carbon dioxide. These ligninolytic enzymes, such as lignin peroxidase, manganese peroxidase and laccase, are capable of degrading a vast range of toxic, recalcitrant environmental pollutants and this makes the white-rot fungi strong candidates for the bioremediation of polluted soils and waters. The laccase enzyme alone has shown remediation potential in wastewaters such as beer production effluent, olive mill wastewater, alcohol distillery wastes, dye-containing wastewaters from the textile industry as well as wastewaters from the paper and pulp industry. It has been shown to be capable of remediating soils and waters polluted with chlorinated phenolic compounds, polyaromatic hydrocarbons, nitrosubstituted compounds and fungicides, herbicides and insecticides.
- Full Text:
- Date Issued: 2008
Reactivity of Rhenium (iii) and Rhenium (V) with multidentate NN-and no-donor ligands
- Yumata, Nonzaliseko Christine
- Authors: Yumata, Nonzaliseko Christine
- Date: 2010
- Subjects: Rhenium , Ligands
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10373 , http://hdl.handle.net/10948/1085 , Rhenium , Ligands
- Description: The reaction of the potentially tridentate Schiff-base chelate Hhaep [Haep = N’-(1- (2-hydroxyphenyl)ethylidene)benzohydrazide] with [ReCl3(benzil)(PPh3)] and trans-[ReOCl3(PPh3)2] produced the neutral oxorhenium(V) complexes cis- [ReOCl2(mep)] [Hmep = 2-(1-iminoethyl)phenol] and cis-[ReOCI2(meb)(PPh3)] [Hmeb = N’-(propan-2-ylidene)benzohydrazide] in ethanol and acetone respectively. In both reactions the Hhaep molecule cleaves to give different coordinated bidentate NO-donor chelates coordinated to the rhenium(V) centers. The X-ray studies reveal that mep is present as a bidentate, monoanionic Schiffbase coordinating through the neutral imino nitrogen and the deprotonated phenolate oxygen in cis-[ReOCl2(mep)]. The bond distances and angles in cis- [ReOCI2(meb)(PPh3)] confirm that meb coordinates to the metal in the enolate form. The distorted octahedral complex fac-[ReCl3(dpa)(PPh3)] was prepared by the reaction of trans-[ReCl3(MeCN)(PPh3)2] with a twofold molar excess of dpa in acetonitrile under a nitrogen atmosphere. The compound dpa.HCl.2H2O was obtained as a by-product in the reaction of dpa with trans-[ReCI3(MeCN)(PPh3)2] in acetonitrile. The reaction of trans-[ReCl3(MeCN)(PPh3)2] with a twofold molar excess of 6- amino-3-methyl-1-phenyl-4-azahept-2-ene-1-one (Hamp) in acetonitrile led to the isolation of cis-[ReCl2(bat)(PPh3)2]. On complexation to the metal center Hamp decomposed to give the coordinated benzoylacetone (bat). Bat is present as a monoanionic bidentate chelate. The complexes [ReVOCI(had)] and [ReIVCl(had)(PPh3)](ReO4) were prepared from the reaction of trans-[ReCl3(MeCN)(PPh3)2] with N,N-bis((2-hydroxybenzyl)-2- aminoethyl)dimethylamine (H2had) in ethanol under various reaction conditions. The treatment of [ReCl3(benzil)(PPh3)] with 2-[((2- pyridinylmethyl)amino)methyl]phenol (Hham) in a 2:1 molar ratio in acetonitrile led to the isolation of the hydrogen-bonded dimer [ReOCl2(ham)]2. The distorted octahedral complex [ReOCl(hap)] [H2hap = N,N-bis(2- hydroxybenzyl)aminomethylpyridine] was prepared from the reaction of trans- [ReCl3(MeCN)(PPh3)2] with a twofold molar excess of H2hap in acetonitrile. The X-ray crystal structure analysis shows that the chloride is coordinated trans to the tripodal tertiary amino nitrogen, with a phenolate oxygen trans to the oxo oxygen.
- Full Text:
- Date Issued: 2010
- Authors: Yumata, Nonzaliseko Christine
- Date: 2010
- Subjects: Rhenium , Ligands
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10373 , http://hdl.handle.net/10948/1085 , Rhenium , Ligands
- Description: The reaction of the potentially tridentate Schiff-base chelate Hhaep [Haep = N’-(1- (2-hydroxyphenyl)ethylidene)benzohydrazide] with [ReCl3(benzil)(PPh3)] and trans-[ReOCl3(PPh3)2] produced the neutral oxorhenium(V) complexes cis- [ReOCl2(mep)] [Hmep = 2-(1-iminoethyl)phenol] and cis-[ReOCI2(meb)(PPh3)] [Hmeb = N’-(propan-2-ylidene)benzohydrazide] in ethanol and acetone respectively. In both reactions the Hhaep molecule cleaves to give different coordinated bidentate NO-donor chelates coordinated to the rhenium(V) centers. The X-ray studies reveal that mep is present as a bidentate, monoanionic Schiffbase coordinating through the neutral imino nitrogen and the deprotonated phenolate oxygen in cis-[ReOCl2(mep)]. The bond distances and angles in cis- [ReOCI2(meb)(PPh3)] confirm that meb coordinates to the metal in the enolate form. The distorted octahedral complex fac-[ReCl3(dpa)(PPh3)] was prepared by the reaction of trans-[ReCl3(MeCN)(PPh3)2] with a twofold molar excess of dpa in acetonitrile under a nitrogen atmosphere. The compound dpa.HCl.2H2O was obtained as a by-product in the reaction of dpa with trans-[ReCI3(MeCN)(PPh3)2] in acetonitrile. The reaction of trans-[ReCl3(MeCN)(PPh3)2] with a twofold molar excess of 6- amino-3-methyl-1-phenyl-4-azahept-2-ene-1-one (Hamp) in acetonitrile led to the isolation of cis-[ReCl2(bat)(PPh3)2]. On complexation to the metal center Hamp decomposed to give the coordinated benzoylacetone (bat). Bat is present as a monoanionic bidentate chelate. The complexes [ReVOCI(had)] and [ReIVCl(had)(PPh3)](ReO4) were prepared from the reaction of trans-[ReCl3(MeCN)(PPh3)2] with N,N-bis((2-hydroxybenzyl)-2- aminoethyl)dimethylamine (H2had) in ethanol under various reaction conditions. The treatment of [ReCl3(benzil)(PPh3)] with 2-[((2- pyridinylmethyl)amino)methyl]phenol (Hham) in a 2:1 molar ratio in acetonitrile led to the isolation of the hydrogen-bonded dimer [ReOCl2(ham)]2. The distorted octahedral complex [ReOCl(hap)] [H2hap = N,N-bis(2- hydroxybenzyl)aminomethylpyridine] was prepared from the reaction of trans- [ReCl3(MeCN)(PPh3)2] with a twofold molar excess of H2hap in acetonitrile. The X-ray crystal structure analysis shows that the chloride is coordinated trans to the tripodal tertiary amino nitrogen, with a phenolate oxygen trans to the oxo oxygen.
- Full Text:
- Date Issued: 2010
The development of the emerging technologies sustainability assessment (ETSA) and its application in the design of a bioprocess for the treatment of wine distillery effluent
- Authors: Khan, Nuraan
- Date: 2005
- Subjects: Technology assessment , Wine and wine making -- Waste disposal , Distilleries -- Waste disposal
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3953 , http://hdl.handle.net/10962/d1004012 , Technology assessment , Wine and wine making -- Waste disposal , Distilleries -- Waste disposal
- Description: Emerging Technologies Sustainability Assessment (ETSA) is a new technology assessment tool that was developed in order to compare emerging processes or technologies to existing alternatives. It utilizes infoIDlation modules, with the minimum use of resources such as time and money, in order to deteIDline if the process under development is comparatively favourable and should be developed beyond the early conceptual phase. The preliminary ETSA is vital in order to identify the gaps in the existing information and the specific methodologies to be used for data capture and analysis. The use of experimental design tools, such as Design-Expert, can facilitate rapid and efficient collection of necessary data and fits in well with the rationale for the ETSA. Wine distillery effluent (vinasse) is the residue left after alcohol has been distilled from fennented grape juice. It is an acidic, darkly coloured effluent, with a high COD and polyphenol content. The most popular method of disposal of this effluent, land application, is no longer viable due to stricter legislation and pressure on the industry to better manage its wastes. Although the ability of whiterot fungi to degrade a number of pollutants is well-known, fungal treatment of wine distillery effluent is still in the conceptual phase. The perfoIDlance of the fungal remediation system was assessed experimentally in terms of COD removal and laccase production using Design-Expert. Although Pycnoporus sanguine us was found to be most efficient at COD removal (85%) from 30% vinasse, laccase production was low (0.021 U/I). The optimum design for economically viable fungal treatment used Trametespubescens. This fungus was able to remove over 50% of the COD from undiluted vinasse while producing almost 800U/l of the valuable laccase enzyme within three days. Since the effluent from the fungal system did not meet the legal limits for wastewater disposal, a two-stage aerobicanaerobic system is suggested to improve the quality of the effluent prior to disposal. The ETSA was used to assess the fungal technology in relation to the two current methods of vinasse treatment and disposal, namely land application and anaerobic digestion. Based on the ETSA, which considered environmental, social and economic impacts, the fungal system proved to be potentially competitive and further development of the technology is suggested.
- Full Text:
- Date Issued: 2005
- Authors: Khan, Nuraan
- Date: 2005
- Subjects: Technology assessment , Wine and wine making -- Waste disposal , Distilleries -- Waste disposal
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3953 , http://hdl.handle.net/10962/d1004012 , Technology assessment , Wine and wine making -- Waste disposal , Distilleries -- Waste disposal
- Description: Emerging Technologies Sustainability Assessment (ETSA) is a new technology assessment tool that was developed in order to compare emerging processes or technologies to existing alternatives. It utilizes infoIDlation modules, with the minimum use of resources such as time and money, in order to deteIDline if the process under development is comparatively favourable and should be developed beyond the early conceptual phase. The preliminary ETSA is vital in order to identify the gaps in the existing information and the specific methodologies to be used for data capture and analysis. The use of experimental design tools, such as Design-Expert, can facilitate rapid and efficient collection of necessary data and fits in well with the rationale for the ETSA. Wine distillery effluent (vinasse) is the residue left after alcohol has been distilled from fennented grape juice. It is an acidic, darkly coloured effluent, with a high COD and polyphenol content. The most popular method of disposal of this effluent, land application, is no longer viable due to stricter legislation and pressure on the industry to better manage its wastes. Although the ability of whiterot fungi to degrade a number of pollutants is well-known, fungal treatment of wine distillery effluent is still in the conceptual phase. The perfoIDlance of the fungal remediation system was assessed experimentally in terms of COD removal and laccase production using Design-Expert. Although Pycnoporus sanguine us was found to be most efficient at COD removal (85%) from 30% vinasse, laccase production was low (0.021 U/I). The optimum design for economically viable fungal treatment used Trametespubescens. This fungus was able to remove over 50% of the COD from undiluted vinasse while producing almost 800U/l of the valuable laccase enzyme within three days. Since the effluent from the fungal system did not meet the legal limits for wastewater disposal, a two-stage aerobicanaerobic system is suggested to improve the quality of the effluent prior to disposal. The ETSA was used to assess the fungal technology in relation to the two current methods of vinasse treatment and disposal, namely land application and anaerobic digestion. Based on the ETSA, which considered environmental, social and economic impacts, the fungal system proved to be potentially competitive and further development of the technology is suggested.
- Full Text:
- Date Issued: 2005