Classification and clustering based methods for outlier detection of solar resource data
- Authors: Abrahams, Waldo
- Date: 2022-04
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/55423 , vital:51996
- Description: Almost 90% of the primary global energy demand is serviced from the burning of fossil fuels (Abas, Kalair & Khan, 2015). Owing to the detrimental environmental impact of this, a global energy transition to the use of renewable energy, including solar energy, is needed (Gielen et al., 2019). An important aspect that inhibits the growth of solar energy is accurate solar resource data. Such data is needed because knowledge of the future reliability and quality of energy production is required to analyse a system’s performance and determine financial implications (Sengupta et al., 2017). Existing methods used to detect outliers in solar resource data do not efficiently identify outliers and an accurate and robust approach is required (Eastwood, 2019). Using simulated and real-world data, this study investigates the use of several classification methods, along with a two-stage clustering-classification approach to accurately identify outliers in solar resource data. The Treebag method proves to be an adequate outlier detection method for solar resource data. , Thesis (MSc) -- Faculty of Science, School of Computer Science, Mathematics, Physics and Statistics, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Abrahams, Waldo
- Date: 2022-04
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/55423 , vital:51996
- Description: Almost 90% of the primary global energy demand is serviced from the burning of fossil fuels (Abas, Kalair & Khan, 2015). Owing to the detrimental environmental impact of this, a global energy transition to the use of renewable energy, including solar energy, is needed (Gielen et al., 2019). An important aspect that inhibits the growth of solar energy is accurate solar resource data. Such data is needed because knowledge of the future reliability and quality of energy production is required to analyse a system’s performance and determine financial implications (Sengupta et al., 2017). Existing methods used to detect outliers in solar resource data do not efficiently identify outliers and an accurate and robust approach is required (Eastwood, 2019). Using simulated and real-world data, this study investigates the use of several classification methods, along with a two-stage clustering-classification approach to accurately identify outliers in solar resource data. The Treebag method proves to be an adequate outlier detection method for solar resource data. , Thesis (MSc) -- Faculty of Science, School of Computer Science, Mathematics, Physics and Statistics, 2022
- Full Text:
- Date Issued: 2022-04
The use of a rapid incineration field test for determining soil organic carbon in the Southern Cape Region
- Authors: Ackhurst, Albert Arthur
- Date: 2014-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/53336 , vital:45135
- Description: Knowledge of soil organic carbon levels is important both for agricultural effectiveness and soil carbon sequestration accounting, especially against the backdrop of increased climate change impacts and pressure on food production landscapes. However, current methods for soil carbon determination are expensive, energy intensive, time consuming and potentially hazardous leading to a call for alternative methods, which should be cheap, fast, simple, accurate, safe and usable where resources and soil analysis laboratories are limited. To this end the student invented a novel rapid incineration field test (RIFT) for determining soil organic carbon and tested its validity in this study. This method incorporates principles found in dry combustion as well as loss-on-ignition and quantifying organic carbon through gravimetric analysis. In order to illustrate effectiveness and accuracy it was necessary to correlate RIFT with a reference method, in this instance dry combustion with a Leco device as well as another commonly used indirect method namely the Walkley-Black wet chemical oxidation method. Samples from eleven soil forms were collected from the Southern Cape region and they were subjected to the three testing methods. It was found that RIFT is indeed as effective and in 72% of the soil forms even more effective than Walkley-Black. Furthermore, it was ascertained whether the accuracy of RIFT can be improved by correcting for clay content. The correlation of RIFT with clay % was not very significant and clay % as a variable was therefore not used in this study to obtain further refinement of RIFT predictions. Another finding was also that RIFT illustrated less variability than both the Leco and Walkley-Black methods. Lastly it was ascertained that the RIFT device and methodology is indeed cost effective, energy efficient, fast and safe in terms of the need to use potentially hazardous chemicals. , Thesis (MA) -- Faculty of Science, School of Natural Resource Management, 2021
- Full Text:
- Date Issued: 2014-12
- Authors: Ackhurst, Albert Arthur
- Date: 2014-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/53336 , vital:45135
- Description: Knowledge of soil organic carbon levels is important both for agricultural effectiveness and soil carbon sequestration accounting, especially against the backdrop of increased climate change impacts and pressure on food production landscapes. However, current methods for soil carbon determination are expensive, energy intensive, time consuming and potentially hazardous leading to a call for alternative methods, which should be cheap, fast, simple, accurate, safe and usable where resources and soil analysis laboratories are limited. To this end the student invented a novel rapid incineration field test (RIFT) for determining soil organic carbon and tested its validity in this study. This method incorporates principles found in dry combustion as well as loss-on-ignition and quantifying organic carbon through gravimetric analysis. In order to illustrate effectiveness and accuracy it was necessary to correlate RIFT with a reference method, in this instance dry combustion with a Leco device as well as another commonly used indirect method namely the Walkley-Black wet chemical oxidation method. Samples from eleven soil forms were collected from the Southern Cape region and they were subjected to the three testing methods. It was found that RIFT is indeed as effective and in 72% of the soil forms even more effective than Walkley-Black. Furthermore, it was ascertained whether the accuracy of RIFT can be improved by correcting for clay content. The correlation of RIFT with clay % was not very significant and clay % as a variable was therefore not used in this study to obtain further refinement of RIFT predictions. Another finding was also that RIFT illustrated less variability than both the Leco and Walkley-Black methods. Lastly it was ascertained that the RIFT device and methodology is indeed cost effective, energy efficient, fast and safe in terms of the need to use potentially hazardous chemicals. , Thesis (MA) -- Faculty of Science, School of Natural Resource Management, 2021
- Full Text:
- Date Issued: 2014-12
Possible futures for the African built environment towards 2050
- Authors: Adendorff, Gillian Lorraine
- Date: 2014-04
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's/Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/53325 , vital:45136
- Description: Purpose –The purpose of this thesis is to develop four scenarios for Africa’s built environment over the nextfortyyears: The ”Angel” or “Good Governance”Scenario,in which positive elements become a realisation for Africa’s built environment and are conjointly favourable; The “Dwarf” or “Uneven African Development”Scenario, in which key driving forces unfold inan uneven pattern, or have a differentiated impact on Africa’s built environment; The “Elf” or Bad Governance Scenario,in which less good governance prevails, but where a fortunate built environment and securemanagement allowsAfrica to become competitive and benefit from satisfactory economic growth;and The “Hobgoblin” or “Business and Governance as usual” Scenario,in which negative regional drivers of change corrode positive policies and initiatives in a manner which compounds the pre-existing threats of Africa’s built environment development.Design/Methodology/Approach –The goal of this thesis is not only to affirm what is already known and knowable regardingwhat is happening right now at the intersections of Africa and its built environment development, but also to explore the many ways in which environmental scanning and built environment development could co-involve,both push and inhibit each other,in the future. Thereafter, this thesis beginsto examine what possible paths may be implicatedfor Africa’s poor and vulnerable built environment. Scenario planning is a methodology designed to help researchers, organisations and even nations alike through this creative process. This thesis begins to identifydriversof change, and then combines these driversin different ways to create a set of scenarios regardinghow the future built environment of Africa could evolve.Practical implications –This thesis provides a useful insight regardingdrivers for change for Africa’s built environment,and how to anticipate these changes in the mostcurrentScenario planning.Originality/Value –This thesis addressesthe future of Africa’s built environment from a decision maker’s point of view over the next 40 years. , Thesis (PhD) -- Faculty of Engineering, the Built Environment and Technology, School of the Built Environment and Civil Engineering, 2021
- Full Text:
- Date Issued: 2014-04
- Authors: Adendorff, Gillian Lorraine
- Date: 2014-04
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's/Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/53325 , vital:45136
- Description: Purpose –The purpose of this thesis is to develop four scenarios for Africa’s built environment over the nextfortyyears: The ”Angel” or “Good Governance”Scenario,in which positive elements become a realisation for Africa’s built environment and are conjointly favourable; The “Dwarf” or “Uneven African Development”Scenario, in which key driving forces unfold inan uneven pattern, or have a differentiated impact on Africa’s built environment; The “Elf” or Bad Governance Scenario,in which less good governance prevails, but where a fortunate built environment and securemanagement allowsAfrica to become competitive and benefit from satisfactory economic growth;and The “Hobgoblin” or “Business and Governance as usual” Scenario,in which negative regional drivers of change corrode positive policies and initiatives in a manner which compounds the pre-existing threats of Africa’s built environment development.Design/Methodology/Approach –The goal of this thesis is not only to affirm what is already known and knowable regardingwhat is happening right now at the intersections of Africa and its built environment development, but also to explore the many ways in which environmental scanning and built environment development could co-involve,both push and inhibit each other,in the future. Thereafter, this thesis beginsto examine what possible paths may be implicatedfor Africa’s poor and vulnerable built environment. Scenario planning is a methodology designed to help researchers, organisations and even nations alike through this creative process. This thesis begins to identifydriversof change, and then combines these driversin different ways to create a set of scenarios regardinghow the future built environment of Africa could evolve.Practical implications –This thesis provides a useful insight regardingdrivers for change for Africa’s built environment,and how to anticipate these changes in the mostcurrentScenario planning.Originality/Value –This thesis addressesthe future of Africa’s built environment from a decision maker’s point of view over the next 40 years. , Thesis (PhD) -- Faculty of Engineering, the Built Environment and Technology, School of the Built Environment and Civil Engineering, 2021
- Full Text:
- Date Issued: 2014-04
Contour plan of Grahamstown
- Authors: AWM , Hodge, WA
- Date: 1934
- Subjects: Grahamstown (South Africa) -- Maps Maps , South Africa
- Language: English
- Type: cartographic , map
- Identifier: http://hdl.handle.net/10962/68301 , vital:29236 , Cory Library for Humanities Research, Rhodes University Library, Grahamstown, South Africa MP407 , MP407
- Description: Contour plan of Grahamstown, 1934. Drawn by A.W.M. ; signed by W.A. Hodge, City Engineer. "War time regulations: this plan must not be removed from college premises under any circumstances" signed by E H Wied.
- Full Text: false
- Date Issued: 1934
- Authors: AWM , Hodge, WA
- Date: 1934
- Subjects: Grahamstown (South Africa) -- Maps Maps , South Africa
- Language: English
- Type: cartographic , map
- Identifier: http://hdl.handle.net/10962/68301 , vital:29236 , Cory Library for Humanities Research, Rhodes University Library, Grahamstown, South Africa MP407 , MP407
- Description: Contour plan of Grahamstown, 1934. Drawn by A.W.M. ; signed by W.A. Hodge, City Engineer. "War time regulations: this plan must not be removed from college premises under any circumstances" signed by E H Wied.
- Full Text: false
- Date Issued: 1934
Plan of the subdivisions of Featherstone's Kloof originally called Kowiefontein showing the portion it is proposed to sell
- Authors: AWM , Hodge, WA
- Date: 1934
- Subjects: Land subdivision - South Africa -- Eastern Cape -- Maps Maps , Featherstone Kloof (Eastern Cape, South Africa) -- Maps Maps , South Africa
- Language: English
- Type: cartographic , map
- Identifier: http://hdl.handle.net/10962/54849 , vital:26621 , Cory Library for Humanities Research, Rhodes University Library, Grahamstown, South Africa MP1462 , MP1462
- Description: Drawn by A.W.M. ; signed by W.A. Hodge, City Engineer.
- Full Text: false
- Date Issued: 1934
- Authors: AWM , Hodge, WA
- Date: 1934
- Subjects: Land subdivision - South Africa -- Eastern Cape -- Maps Maps , Featherstone Kloof (Eastern Cape, South Africa) -- Maps Maps , South Africa
- Language: English
- Type: cartographic , map
- Identifier: http://hdl.handle.net/10962/54849 , vital:26621 , Cory Library for Humanities Research, Rhodes University Library, Grahamstown, South Africa MP1462 , MP1462
- Description: Drawn by A.W.M. ; signed by W.A. Hodge, City Engineer.
- Full Text: false
- Date Issued: 1934
Self-concept as a measure of success in the military environment
- Authors: Besener, Paul Robert
- Date: 1987
- Subjects: Self-perception , Control , Recruits , Soldiers , Military , National service , South Africa , Pupils , Learners , Guidance , School curriculum
- Language: English
- Type: text , Thesis , Masters , MEd
- Identifier: vital:1363 , http://hdl.handle.net/10962/d1001429
- Description: This piece of research is an attempt to evaluate the relationship between military 'success' and the psychological preparedness of recruits in terms of their self-concepts and locus of control orientations. The new recruit is forced to adapt to the military environment which will, in turn, attempt to change him into an effective soldier. It was noticed by the researcher, who was involved in military training at the time, that a number of recruits, even some with seemingly limited potential, coped well, while others who seemed to have the ability failed to cope adequately. Recruits completed questionnaires which provided the researcher with biographical data and background information. In addition, the Bledsoe Self-Concept Scale and the Nowicki and Strickland Locus of Control Scale were used in order to determine their self-concepts and locus of control orientations respectively, prior to the beginning of national service. Detailed unstructured interviews were also conducted with a sample of military personnel, to provide another basis for gathering data and for clarifying some of the issues involved. Briefly, the chief conclusion of this researcher is that a significant majority of 'successful' recruits in the military environment have a positive self-concept and an internal locus of control. On the basis of the above finding, it is suggested that there is a need to guide pupils about certain aspects of military life before they begin their National Service. There would seem to be a need for this guidance to be incorporated into the school curriculum, together with such practical aspects as cadets, shooting, etc. There is a shortage of this kind of research on the military situation in South Africa, and it is suggested that numerous issues in this field need to be researched for the benefit of future conscripts and the military alike.
- Full Text:
- Date Issued: 1987
- Authors: Besener, Paul Robert
- Date: 1987
- Subjects: Self-perception , Control , Recruits , Soldiers , Military , National service , South Africa , Pupils , Learners , Guidance , School curriculum
- Language: English
- Type: text , Thesis , Masters , MEd
- Identifier: vital:1363 , http://hdl.handle.net/10962/d1001429
- Description: This piece of research is an attempt to evaluate the relationship between military 'success' and the psychological preparedness of recruits in terms of their self-concepts and locus of control orientations. The new recruit is forced to adapt to the military environment which will, in turn, attempt to change him into an effective soldier. It was noticed by the researcher, who was involved in military training at the time, that a number of recruits, even some with seemingly limited potential, coped well, while others who seemed to have the ability failed to cope adequately. Recruits completed questionnaires which provided the researcher with biographical data and background information. In addition, the Bledsoe Self-Concept Scale and the Nowicki and Strickland Locus of Control Scale were used in order to determine their self-concepts and locus of control orientations respectively, prior to the beginning of national service. Detailed unstructured interviews were also conducted with a sample of military personnel, to provide another basis for gathering data and for clarifying some of the issues involved. Briefly, the chief conclusion of this researcher is that a significant majority of 'successful' recruits in the military environment have a positive self-concept and an internal locus of control. On the basis of the above finding, it is suggested that there is a need to guide pupils about certain aspects of military life before they begin their National Service. There would seem to be a need for this guidance to be incorporated into the school curriculum, together with such practical aspects as cadets, shooting, etc. There is a shortage of this kind of research on the military situation in South Africa, and it is suggested that numerous issues in this field need to be researched for the benefit of future conscripts and the military alike.
- Full Text:
- Date Issued: 1987
An investigation into the effects of nano-carbons on the negative electrode morphology of lead acid batteries under high rate partial state of capacity cycling
- Authors: Bolo, Lukanyo
- Date: 2021-04
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/53324 , vital:45132
- Description: New technological developments in the field of Hybrid Electric Vehicles (HEV’s), vehicle stop-start applications and electrical power utility devices have brought about new demands on the use of energy storage devices such as the Pb-acid battery. These applications require a new understanding and research into the material chemistry of the battery where it has to functionin a Partial State of Capacity Cycling (PSoCC) or High Rate Partial State of Capacity Cycling (HRPSoCC)duty. The Pb-acid battery is well known for its use in the automotive industry where it had worked for decades as a typical Starter, Lighting and Ignition (SLI) power source. However, the conventional Pb-acid battery is not suitable for the new types of vehicle demands and applications. When the Pb-lead acid battery is subjected to PSoCC conditions, very quickly excessive amount of non-conducting PbSO4crystals are formed on the negative plates of the battery that then drastically reduce its useful life in application. Over the years, researchers have shown that the small addition of certain carbon types to the negative plate active material (NAM) during battery manufacturing can reduce the sulfation effect thereby increasing its use the modern vehicle applications. This study investigated industrial manufactured cells that contained up to 0.5 % by weight two types of carbons in the NAM. These were compared to standard built cells in terms of their standard achievable capacities at various rates, their Cold Cranking Ability (CCA), their Dynamic Charge Acceptance (DCA) and a simplified PSoCC test. The carbons were classified as an activated carbon and a carbon nano-fiber and were included as a dry weight additive during the standard paste manufacturing process of the negative plate. Cells were built with a 9-plate configuration using standard expanded grid positive plates with a nominal rated capacity of 36 Ah. The cells were formed and subjected to a number of electrochemical tests, of which selected negative plates were then studied using Scanning Electron Microscopy (SEM) and Electrochemical in-situ Atomic Force Microscopy (EC-AFM). The microscopic study was then used to try and relate the observed material characteristics of the NAM with the carbons to the electrochemical results observed when testing a built cell. , Thesis (MA) --Faculty of Science, School of Biomolecular and Chemical Sciences, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Bolo, Lukanyo
- Date: 2021-04
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/53324 , vital:45132
- Description: New technological developments in the field of Hybrid Electric Vehicles (HEV’s), vehicle stop-start applications and electrical power utility devices have brought about new demands on the use of energy storage devices such as the Pb-acid battery. These applications require a new understanding and research into the material chemistry of the battery where it has to functionin a Partial State of Capacity Cycling (PSoCC) or High Rate Partial State of Capacity Cycling (HRPSoCC)duty. The Pb-acid battery is well known for its use in the automotive industry where it had worked for decades as a typical Starter, Lighting and Ignition (SLI) power source. However, the conventional Pb-acid battery is not suitable for the new types of vehicle demands and applications. When the Pb-lead acid battery is subjected to PSoCC conditions, very quickly excessive amount of non-conducting PbSO4crystals are formed on the negative plates of the battery that then drastically reduce its useful life in application. Over the years, researchers have shown that the small addition of certain carbon types to the negative plate active material (NAM) during battery manufacturing can reduce the sulfation effect thereby increasing its use the modern vehicle applications. This study investigated industrial manufactured cells that contained up to 0.5 % by weight two types of carbons in the NAM. These were compared to standard built cells in terms of their standard achievable capacities at various rates, their Cold Cranking Ability (CCA), their Dynamic Charge Acceptance (DCA) and a simplified PSoCC test. The carbons were classified as an activated carbon and a carbon nano-fiber and were included as a dry weight additive during the standard paste manufacturing process of the negative plate. Cells were built with a 9-plate configuration using standard expanded grid positive plates with a nominal rated capacity of 36 Ah. The cells were formed and subjected to a number of electrochemical tests, of which selected negative plates were then studied using Scanning Electron Microscopy (SEM) and Electrochemical in-situ Atomic Force Microscopy (EC-AFM). The microscopic study was then used to try and relate the observed material characteristics of the NAM with the carbons to the electrochemical results observed when testing a built cell. , Thesis (MA) --Faculty of Science, School of Biomolecular and Chemical Sciences, 2021
- Full Text:
- Date Issued: 2021-04
Be alright
- Botha, Karika (Recorded by), Sesotho women choir (Performer), Composer not specified
- Authors: Botha, Karika (Recorded by) , Sesotho women choir (Performer) , Composer not specified
- Subjects: Shongoane village , Lephalale , Transvaal (Limpopo) , South Africa , Religious music , Church music , Choral
- Language: English
- Type: Music , Sound
- Identifier: vital:15635 , JKC17a-06 , http://hdl.handle.net/10962/d1008824 , Tape number: JKC17 , Original tape number: 17 , Track number: 06
- Description: Unaccompanied church song , Refer to last page of Jaco Kruger recording card book II
- Full Text: false
- Authors: Botha, Karika (Recorded by) , Sesotho women choir (Performer) , Composer not specified
- Subjects: Shongoane village , Lephalale , Transvaal (Limpopo) , South Africa , Religious music , Church music , Choral
- Language: English
- Type: Music , Sound
- Identifier: vital:15635 , JKC17a-06 , http://hdl.handle.net/10962/d1008824 , Tape number: JKC17 , Original tape number: 17 , Track number: 06
- Description: Unaccompanied church song , Refer to last page of Jaco Kruger recording card book II
- Full Text: false
I'll be missing you
- Botha, Karika (Recorded by), Sesotho children (Performer), Composer unknown
- Authors: Botha, Karika (Recorded by) , Sesotho children (Performer) , Composer unknown
- Subjects: Shongoane village , Lephalale , Transvaal (Limpopo) , South Africa , Pop song with a religious character
- Language: English
- Type: Music , Sound
- Identifier: vital:16067 , JKC17b-23 , http://hdl.handle.net/10962/d1009256 , Tape number: JKC17 , Original tape number: 17 , Track number: 23
- Description: Unaccompanied pop song sung by children , Refer to last page of Jaco Kruger recording card book II
- Full Text: false
- Authors: Botha, Karika (Recorded by) , Sesotho children (Performer) , Composer unknown
- Subjects: Shongoane village , Lephalale , Transvaal (Limpopo) , South Africa , Pop song with a religious character
- Language: English
- Type: Music , Sound
- Identifier: vital:16067 , JKC17b-23 , http://hdl.handle.net/10962/d1009256 , Tape number: JKC17 , Original tape number: 17 , Track number: 23
- Description: Unaccompanied pop song sung by children , Refer to last page of Jaco Kruger recording card book II
- Full Text: false
Sweet Jesus
- Botha, Karika (Recorded by), Sesotho women choir (Performer), Composer not specified
- Authors: Botha, Karika (Recorded by) , Sesotho women choir (Performer) , Composer not specified
- Subjects: Shongoane village , Lephalale , Transvaal (Limpopo) , South Africa , Religious music , Church music , Choral
- Language: English
- Type: Music , Sound
- Identifier: vital:15784 , JKC17a-16 , http://hdl.handle.net/10962/d1008973 , Tape number: JKC17 , Track number: 16 , Original tape number: 17
- Description: Unaccompanied religious choral Sesotho song , Refer to last page of Jaco Kruger recording card book II
- Full Text: false
- Authors: Botha, Karika (Recorded by) , Sesotho women choir (Performer) , Composer not specified
- Subjects: Shongoane village , Lephalale , Transvaal (Limpopo) , South Africa , Religious music , Church music , Choral
- Language: English
- Type: Music , Sound
- Identifier: vital:15784 , JKC17a-16 , http://hdl.handle.net/10962/d1008973 , Tape number: JKC17 , Track number: 16 , Original tape number: 17
- Description: Unaccompanied religious choral Sesotho song , Refer to last page of Jaco Kruger recording card book II
- Full Text: false
In the bible
- Botha, Karika (Recorded by), Sesotho children (Performer), Composer not specified
- Authors: Botha, Karika (Recorded by) , Sesotho children (Performer) , Composer not specified
- Subjects: Shongoane village , Lephalale , Transvaal (Limpopo) , South Africa , Religious music , Church song , Choral
- Language: English
- Type: Music , Sound
- Identifier: vital:16078 , JKC17b-15 , http://hdl.handle.net/10962/d1009267 , Tape number: JKC17 , Original tape number: 17 , Track number: 15
- Description: Unaccompanied religious choral Sesotho song , Refer to last page of Jaco Kruger recording card book II
- Full Text: false
- Authors: Botha, Karika (Recorded by) , Sesotho children (Performer) , Composer not specified
- Subjects: Shongoane village , Lephalale , Transvaal (Limpopo) , South Africa , Religious music , Church song , Choral
- Language: English
- Type: Music , Sound
- Identifier: vital:16078 , JKC17b-15 , http://hdl.handle.net/10962/d1009267 , Tape number: JKC17 , Original tape number: 17 , Track number: 15
- Description: Unaccompanied religious choral Sesotho song , Refer to last page of Jaco Kruger recording card book II
- Full Text: false
The petrogenesis of the volcanic rocks of the Witwatersrand triad in the Klerksdorp area, Transvaal
- Authors: Bowen, Michael Peter
- Date: 1985
- Subjects: Volcanic rocks , Witwatersrand triad , Klerksdorp , Transvaal , Northwest Province , South Africa , Chemical analysis , Magma , Geology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4909 , http://hdl.handle.net/10962/d1001569
- Description: Several hundred chemical analyses of early Proterozoic lavas of the Witwatersrand triad (incorporating the Dominion Group, Witwatersrand Supergroup and Ventersdorp Supergroup) in the Klerksdorp area, have revealed the presence of various distinct magma types. These essentially correspond to formally defined lithostratigraphic units, but several inconsistencies have necessitated the use of informal nomenclature. The lavas have been regionally metamorphosed to low-grade, greenschist facies assemblages. Original igneous textures are preserved, despite a metamorphic overprint. Metamorphism has resulted in a certain degree of random chemical remobilization. Ba, Sr, Rb, K₂0, Na₂0 and CaO have been highly mobile, and their usefulness in petrogenetic modelling is extremely limited. In contrast, Zr, Nb, Y, LREE's, Cr, Ni, Ti0₂ P₂0₅ and Al₂0₃ have remained immobile. Ti/Zr and Ti/P ratios together constitute efficient discriminating variables for characterizing the different magma types. Lava compositions range from primitive Mg-rich tholeiites to rhyolites, the bulk being tholeiitic andesites. Al₂0₃ contents do not exceed 15%, a feature which reflects the tholeiitic, as opposed to calcalkaline, character of these lavas. Two magma-types are present within the Dominion Group, which is a typical example of bimodal volcanism. The Dominion basic lavas are overlain by the Dominion acid porphyries, with a limited amount of interfingering. The basic lava suite is highly fractionated, with compositions ranging from Mg-, Cr- and Ni-rich tholeiites (close to primary mantle melts) to evolved tholeiitic andesites. The most primitive liquids evolved by 45% fractional crystallization of hornblende, followed by a further 70% crystallization of an orthopyroxene-plagioclase assemblage containing up to 3% sulphides. The Dominion porphyries are rhyolitic, display very limited compositional variation, and probably represent a crustal melt related to the same magmatic event which produced the basic lavas. The only lavas from the Witwatersrand Supergroup present in the Klerksdorp area are those of the Crown Formation (Jeppestown amygdaloid). These are tholeiitic dacites which display extremely limited compositional variation, and are unrelated to any of the other magmas of the Witwatersrand triad. The Ventersdorp Supergroup comprises 4 magma-types: The Kliprivierberg Group lavas at the base are subdivisible into 3 sub-types on the basis of Zr contents. (Zr>11Oppm) are the most evolved. They are tholeiitic andesites which display fairly limited compositional variation. It is likely that more evolved compositions are present in other areas where the porphyritic lavas which characterize this unit are better developed. The overlying Orkney lavas are characterized by 110ppm>Zr>90ppm. They are tholeiitic andesites of similar composition to the Alberton lavas, but have lower incompatible element levels, higher siderophile element levels, and are of extremely uniform composition. The uppermost Loraine/Edenville lavas range from magnesian tholeiites to tholeiitic andesites. They are distinguished by Zr< 90ppm, and contain the most primitive magmas af the Witwatersrand triad, with up to 17,5% MgO, 2600ppm Cr, 600ppm Ni and M-values up to 77. The most primitive liquids evolved by 38% fractional crystallization of orthopyroxene ∓ chromite, followed by 35% fractional crystallization of an extract containing clinopyroxene and plagioclase. The absence of olivine precipitation is a result of the inherently high Si0₂ content of the magma. The Loraine/Edenville, Orkney and Alberton lavas do not lie on a common liquid line of descent, but are probably consanguinous. The Platberg Group overlies the Kliprivierberg Group, and has a coarse-clastic sedimentary unit, the Kameeldoorns Formation, at the base. Three petrographically distinct porphyritic lava sequences overlie the Kameeldoorns Formation, namely the informal "Goedgenoeg formation", the Makwassie quartz-feldspar porphyries and the Rietgat Formation. Despite petrographic differences, the Goedgenoeg and Rietgat lavas are chemically indistinguishable and thus form a single magma-type. The Makwassie porphyries are dacitic in composition with a high proportion of feldspar and quartz phenocrysts. Rational variation trends are attributed to a nett loss of Si0₂ during secondary alteration. The porphyries are probably of crustal origin. The Goedgenoeg/Rietgat lavas display unusual chemistry and a broad, irrational compositional spectrum. They contain very high incompatible element levels, high nonnative quartz, as well as high MgO, M-values, Cr and Ni relative to the other tholeiitic andesites of the Witwatersrand triad. It is tentatively suggested that they are hybrid magmas containing both crust and mantle components, the former possibly represented by the Makwassie porphyries. Field evidence suggests that Platberg volcanism commenced directly after Klipriviersberg volcanism ceased, and was accompanied by a period of enhanced tectonic activity. The Platberg lavas thus probably reflect a crustal melting cycle associated with the Klipriviersberg magmatic event. The Allanridge lavas are the youngest rocks of the Witwatersrand triad. They are separated from the Platberg Group by a unit of flat-lying sediments, the Bothaville Formation, which was deposited after an extended period of peneplanation. The Allanridge lavas form a separate magma-type. They are tholeiitic andesites of similar composition to the Alberton lavas, but have higher incompatible element levels and are not consanguinous. The compositional similarities amongst the basic magma-types of the Witwatersrand triad suggests that all were generated in an hydrous mantle. Interelement ratio differences between the various magma-types nevertheless support the concept that the mantle was chemically heterogeneous during the early Proterozoic.
- Full Text:
- Date Issued: 1985
- Authors: Bowen, Michael Peter
- Date: 1985
- Subjects: Volcanic rocks , Witwatersrand triad , Klerksdorp , Transvaal , Northwest Province , South Africa , Chemical analysis , Magma , Geology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4909 , http://hdl.handle.net/10962/d1001569
- Description: Several hundred chemical analyses of early Proterozoic lavas of the Witwatersrand triad (incorporating the Dominion Group, Witwatersrand Supergroup and Ventersdorp Supergroup) in the Klerksdorp area, have revealed the presence of various distinct magma types. These essentially correspond to formally defined lithostratigraphic units, but several inconsistencies have necessitated the use of informal nomenclature. The lavas have been regionally metamorphosed to low-grade, greenschist facies assemblages. Original igneous textures are preserved, despite a metamorphic overprint. Metamorphism has resulted in a certain degree of random chemical remobilization. Ba, Sr, Rb, K₂0, Na₂0 and CaO have been highly mobile, and their usefulness in petrogenetic modelling is extremely limited. In contrast, Zr, Nb, Y, LREE's, Cr, Ni, Ti0₂ P₂0₅ and Al₂0₃ have remained immobile. Ti/Zr and Ti/P ratios together constitute efficient discriminating variables for characterizing the different magma types. Lava compositions range from primitive Mg-rich tholeiites to rhyolites, the bulk being tholeiitic andesites. Al₂0₃ contents do not exceed 15%, a feature which reflects the tholeiitic, as opposed to calcalkaline, character of these lavas. Two magma-types are present within the Dominion Group, which is a typical example of bimodal volcanism. The Dominion basic lavas are overlain by the Dominion acid porphyries, with a limited amount of interfingering. The basic lava suite is highly fractionated, with compositions ranging from Mg-, Cr- and Ni-rich tholeiites (close to primary mantle melts) to evolved tholeiitic andesites. The most primitive liquids evolved by 45% fractional crystallization of hornblende, followed by a further 70% crystallization of an orthopyroxene-plagioclase assemblage containing up to 3% sulphides. The Dominion porphyries are rhyolitic, display very limited compositional variation, and probably represent a crustal melt related to the same magmatic event which produced the basic lavas. The only lavas from the Witwatersrand Supergroup present in the Klerksdorp area are those of the Crown Formation (Jeppestown amygdaloid). These are tholeiitic dacites which display extremely limited compositional variation, and are unrelated to any of the other magmas of the Witwatersrand triad. The Ventersdorp Supergroup comprises 4 magma-types: The Kliprivierberg Group lavas at the base are subdivisible into 3 sub-types on the basis of Zr contents. (Zr>11Oppm) are the most evolved. They are tholeiitic andesites which display fairly limited compositional variation. It is likely that more evolved compositions are present in other areas where the porphyritic lavas which characterize this unit are better developed. The overlying Orkney lavas are characterized by 110ppm>Zr>90ppm. They are tholeiitic andesites of similar composition to the Alberton lavas, but have lower incompatible element levels, higher siderophile element levels, and are of extremely uniform composition. The uppermost Loraine/Edenville lavas range from magnesian tholeiites to tholeiitic andesites. They are distinguished by Zr< 90ppm, and contain the most primitive magmas af the Witwatersrand triad, with up to 17,5% MgO, 2600ppm Cr, 600ppm Ni and M-values up to 77. The most primitive liquids evolved by 38% fractional crystallization of orthopyroxene ∓ chromite, followed by 35% fractional crystallization of an extract containing clinopyroxene and plagioclase. The absence of olivine precipitation is a result of the inherently high Si0₂ content of the magma. The Loraine/Edenville, Orkney and Alberton lavas do not lie on a common liquid line of descent, but are probably consanguinous. The Platberg Group overlies the Kliprivierberg Group, and has a coarse-clastic sedimentary unit, the Kameeldoorns Formation, at the base. Three petrographically distinct porphyritic lava sequences overlie the Kameeldoorns Formation, namely the informal "Goedgenoeg formation", the Makwassie quartz-feldspar porphyries and the Rietgat Formation. Despite petrographic differences, the Goedgenoeg and Rietgat lavas are chemically indistinguishable and thus form a single magma-type. The Makwassie porphyries are dacitic in composition with a high proportion of feldspar and quartz phenocrysts. Rational variation trends are attributed to a nett loss of Si0₂ during secondary alteration. The porphyries are probably of crustal origin. The Goedgenoeg/Rietgat lavas display unusual chemistry and a broad, irrational compositional spectrum. They contain very high incompatible element levels, high nonnative quartz, as well as high MgO, M-values, Cr and Ni relative to the other tholeiitic andesites of the Witwatersrand triad. It is tentatively suggested that they are hybrid magmas containing both crust and mantle components, the former possibly represented by the Makwassie porphyries. Field evidence suggests that Platberg volcanism commenced directly after Klipriviersberg volcanism ceased, and was accompanied by a period of enhanced tectonic activity. The Platberg lavas thus probably reflect a crustal melting cycle associated with the Klipriviersberg magmatic event. The Allanridge lavas are the youngest rocks of the Witwatersrand triad. They are separated from the Platberg Group by a unit of flat-lying sediments, the Bothaville Formation, which was deposited after an extended period of peneplanation. The Allanridge lavas form a separate magma-type. They are tholeiitic andesites of similar composition to the Alberton lavas, but have higher incompatible element levels and are not consanguinous. The compositional similarities amongst the basic magma-types of the Witwatersrand triad suggests that all were generated in an hydrous mantle. Interelement ratio differences between the various magma-types nevertheless support the concept that the mantle was chemically heterogeneous during the early Proterozoic.
- Full Text:
- Date Issued: 1985
Sketch map of the portion of the territory of East Griqualand : traversed while settling locations by the vacant Land Commissioners
- Brownlee, C, Strachan, Donald, Watermeyer, C P, Watermeyer, F S, Cape of Good Hope (Colony). Surveyor General, Surveyor General's Department, Saul Solomon & Co.
- Authors: Brownlee, C , Strachan, Donald , Watermeyer, C P , Watermeyer, F S , Cape of Good Hope (Colony). Surveyor General , Surveyor General's Department , Saul Solomon & Co.
- Date: 1883
- Subjects: East Griqualand (South Africa) -- Administrative and political divisions -- Maps Maps , South Africa
- Language: English
- Type: map , cartographic
- Identifier: http://hdl.handle.net/10962/62099 , vital:28127 , Cory Library for Humanities Research, Rhodes University Library, Grahamstown, South Africa
- Description: Sketch map of the portion of the territory of East Griqualand : traversed while settling locations by the vacant Land Commissioners. The Hon. C. Brownlee, CMG Donald Strachan and CP Watermeyer in June-September 1883.
- Full Text: false
- Date Issued: 1883
- Authors: Brownlee, C , Strachan, Donald , Watermeyer, C P , Watermeyer, F S , Cape of Good Hope (Colony). Surveyor General , Surveyor General's Department , Saul Solomon & Co.
- Date: 1883
- Subjects: East Griqualand (South Africa) -- Administrative and political divisions -- Maps Maps , South Africa
- Language: English
- Type: map , cartographic
- Identifier: http://hdl.handle.net/10962/62099 , vital:28127 , Cory Library for Humanities Research, Rhodes University Library, Grahamstown, South Africa
- Description: Sketch map of the portion of the territory of East Griqualand : traversed while settling locations by the vacant Land Commissioners. The Hon. C. Brownlee, CMG Donald Strachan and CP Watermeyer in June-September 1883.
- Full Text: false
- Date Issued: 1883
A study of the airflow on the windward slope of a transverse dune in the Alexandria coastal dunefield
- Authors: Burkinshaw, Jennifer Ruth
- Date: 2021-04
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/52734 , vital:43883
- Description: Our understanding of the evolution of dune morphology has been hampered by a lack of empirical observations of airflow behaviour over dune forms. Sand dunes intrude into the atmospheric boundary layer and convergence of streamlines results in an acceleration of airflow up the windward slopes of dunes. This study examines the airflow structure and corresponding bedform development on the windward slope of a 7 m high transverse dune on the edge of the Alexandria coastal dunefield, Algoa Bay, South Africa. The Alexandria dunefield is subjected to a trimodal wind regime, consisting of the dominant south-westerly which blows all year round, summer easterlies and winter northwesterlies. The morphology of the study dune, Dune13, is controlled by the easterlies and north-westerlies, and reverses seasonally with respect to these two winds. Seven section lines 30 m apart and normal to the dune crest were surveyed regularly over the period of a year to monitor the reversal process. Three detailed topographic surveys were also done during this period. Airflow behaviour was monitored during the year. Wind speed profiles on the windward slope of the dune were measured using 4 to 5 vertical arrays of anemometers positioned from the base of the dune to the crest on a 1 selected section line. Usually 4 to 5 anemometers were deployed in each vertical array, from a height of 6 to 10 cm above the surface, up to a height of 150 cm above the surface. Initially 8 microanemometers were available; ultimately 28 anemometers were run simultaneously. An independent weather station at an elevation of 6 m recorded the unaccelerated flow. Local gradient measurements and erosion and deposition rates were recorded along selected section lines. Strong summer easterly winds (14 m/sec at 1.4 m above the dune crest) were measured on a dune slope in the process of being transformed from a slipface to a stoss slope. The following winter, light north-westerly winds (typically B m/sec at 1.6 m above the dune crest) were measured on the new windward slope already reversed by the prevailing winter wind. Airflow data confirm the compression of airflow against the windward slope resulting in a non-logarithmic wind speed profile. Compression results in an increased shear velocity within 30 cm of the dune surface, and the dune slope is eroded. Higher up in the wind speed profile, shear velocity decreases to 0.1 m/sec. It is not known at what height the wind speed profile recovers from the intrusion of the dune into the boundary layer. High values of shear velocity (1.6 m/sec) above the rounded crestal area of the dune record the recovery of the wind speed profile from flow divergence, which is a response to the rapid reduction of dune gradient and is accompanied by deposition of sand in this region. 2 The erosion pin data act as a simple and sensitive test for changes in gradient, reflecting the dune's response to changes in the airflow regime. The shape of the dune plays a major role in determining the extent of the compression and the distribution of shear velocity up the slope. Increased shear velocity is experienced on that part of the slope which is nonaerodynamic with respect to the prevailing wind. Under unidirectional conditions, feedback between flow and form results ultimately in a slope with a curvature such that shear velocity increases systematically upslope. The survey data and erosion pin data record the reversal process as the dune achieves a new steady state during each wind season. The existence of a non-logarithmic wind speed profile makes it difficult to know what relevant measure of shear velocity is to be used in sand transport equations. Future work should include wind speed measurements within 10 cm of the surface. An ideal study modelling aeolian bedform development would utilise wind tunnel measurements, combined with field measurements such as obtained in this study, for comparison with numerical modelling. The study needs to be extended to 3-dimensional airflow measurements. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Burkinshaw, Jennifer Ruth
- Date: 2021-04
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/52734 , vital:43883
- Description: Our understanding of the evolution of dune morphology has been hampered by a lack of empirical observations of airflow behaviour over dune forms. Sand dunes intrude into the atmospheric boundary layer and convergence of streamlines results in an acceleration of airflow up the windward slopes of dunes. This study examines the airflow structure and corresponding bedform development on the windward slope of a 7 m high transverse dune on the edge of the Alexandria coastal dunefield, Algoa Bay, South Africa. The Alexandria dunefield is subjected to a trimodal wind regime, consisting of the dominant south-westerly which blows all year round, summer easterlies and winter northwesterlies. The morphology of the study dune, Dune13, is controlled by the easterlies and north-westerlies, and reverses seasonally with respect to these two winds. Seven section lines 30 m apart and normal to the dune crest were surveyed regularly over the period of a year to monitor the reversal process. Three detailed topographic surveys were also done during this period. Airflow behaviour was monitored during the year. Wind speed profiles on the windward slope of the dune were measured using 4 to 5 vertical arrays of anemometers positioned from the base of the dune to the crest on a 1 selected section line. Usually 4 to 5 anemometers were deployed in each vertical array, from a height of 6 to 10 cm above the surface, up to a height of 150 cm above the surface. Initially 8 microanemometers were available; ultimately 28 anemometers were run simultaneously. An independent weather station at an elevation of 6 m recorded the unaccelerated flow. Local gradient measurements and erosion and deposition rates were recorded along selected section lines. Strong summer easterly winds (14 m/sec at 1.4 m above the dune crest) were measured on a dune slope in the process of being transformed from a slipface to a stoss slope. The following winter, light north-westerly winds (typically B m/sec at 1.6 m above the dune crest) were measured on the new windward slope already reversed by the prevailing winter wind. Airflow data confirm the compression of airflow against the windward slope resulting in a non-logarithmic wind speed profile. Compression results in an increased shear velocity within 30 cm of the dune surface, and the dune slope is eroded. Higher up in the wind speed profile, shear velocity decreases to 0.1 m/sec. It is not known at what height the wind speed profile recovers from the intrusion of the dune into the boundary layer. High values of shear velocity (1.6 m/sec) above the rounded crestal area of the dune record the recovery of the wind speed profile from flow divergence, which is a response to the rapid reduction of dune gradient and is accompanied by deposition of sand in this region. 2 The erosion pin data act as a simple and sensitive test for changes in gradient, reflecting the dune's response to changes in the airflow regime. The shape of the dune plays a major role in determining the extent of the compression and the distribution of shear velocity up the slope. Increased shear velocity is experienced on that part of the slope which is nonaerodynamic with respect to the prevailing wind. Under unidirectional conditions, feedback between flow and form results ultimately in a slope with a curvature such that shear velocity increases systematically upslope. The survey data and erosion pin data record the reversal process as the dune achieves a new steady state during each wind season. The existence of a non-logarithmic wind speed profile makes it difficult to know what relevant measure of shear velocity is to be used in sand transport equations. Future work should include wind speed measurements within 10 cm of the surface. An ideal study modelling aeolian bedform development would utilise wind tunnel measurements, combined with field measurements such as obtained in this study, for comparison with numerical modelling. The study needs to be extended to 3-dimensional airflow measurements. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2021
- Full Text:
- Date Issued: 2021-04
Graphicacy and the third dimension: an investigation into the problem of poor performance in relief mapwork in South African secondary schools
- Burton, Michael St. John Whitehead
- Authors: Burton, Michael St. John Whitehead
- Date: 1986
- Subjects: Graphicacy , Maps , Map reading , Visualisation , Geography , Secondary education , South Africa , Pupils , Learners , Teachers
- Language: English
- Type: text , Thesis , Masters , MEd
- Identifier: vital:1358 , http://hdl.handle.net/10962/d1001424
- Description: Three-dimensional graphicacy is the part of map work that appears to be the most problematIcal. Bartz (1970) says that thinking and visualising in three-dimensional space is difficult enough, but trying to derive notions in three-dimensions, when you have only seen them as they are represented in distorted two-dimensional fashion, is even more difficult. Yet pupils of geography are required to learn such three-dimensional concepts from the two-dimensional distorted map presentations. The geography teacher has an important educational role to play in promoting graphicacy and Balchin (1965), who coined the term, felt that it should be an essential underpinning of an integrated education. The problem is that children perform badly, teachers are not successfully imparting three-dimensional graphicacy skills and as Board and Taylor (1977) indicate, for some time now it has been fashionable to dismiss maps as being irrelevant or useless in geographical research. This thesis attempts to analyse this reported malady, the problems are exposed and solutions offered. Investigation of the literature, with the aim of clarifying the problems involved, follows four leads. These are the part played by the map as a mode of communication, the physical processes involved in mapwork revealed by work in the realm of neurophysiology, the process of visualisation in the field of perception and psychology, and finally the stage of conceptual development of the mapworker. The state of affairs in South Africa is disclosed by an analysis of teacher-directed literature, of examination syllabuses, of text-book treatment of three-dimensional mapwork in South Africa and overseas, of past examination questions, and finally of teachers' views. Experimental exercises have been executed in an attempt to link the key findings of published research to the local scene. Conclusions are then drawn, and recommendations made for improving three-dimensional graphicacy in South African secondary schools.
- Full Text:
- Date Issued: 1986
- Authors: Burton, Michael St. John Whitehead
- Date: 1986
- Subjects: Graphicacy , Maps , Map reading , Visualisation , Geography , Secondary education , South Africa , Pupils , Learners , Teachers
- Language: English
- Type: text , Thesis , Masters , MEd
- Identifier: vital:1358 , http://hdl.handle.net/10962/d1001424
- Description: Three-dimensional graphicacy is the part of map work that appears to be the most problematIcal. Bartz (1970) says that thinking and visualising in three-dimensional space is difficult enough, but trying to derive notions in three-dimensions, when you have only seen them as they are represented in distorted two-dimensional fashion, is even more difficult. Yet pupils of geography are required to learn such three-dimensional concepts from the two-dimensional distorted map presentations. The geography teacher has an important educational role to play in promoting graphicacy and Balchin (1965), who coined the term, felt that it should be an essential underpinning of an integrated education. The problem is that children perform badly, teachers are not successfully imparting three-dimensional graphicacy skills and as Board and Taylor (1977) indicate, for some time now it has been fashionable to dismiss maps as being irrelevant or useless in geographical research. This thesis attempts to analyse this reported malady, the problems are exposed and solutions offered. Investigation of the literature, with the aim of clarifying the problems involved, follows four leads. These are the part played by the map as a mode of communication, the physical processes involved in mapwork revealed by work in the realm of neurophysiology, the process of visualisation in the field of perception and psychology, and finally the stage of conceptual development of the mapworker. The state of affairs in South Africa is disclosed by an analysis of teacher-directed literature, of examination syllabuses, of text-book treatment of three-dimensional mapwork in South Africa and overseas, of past examination questions, and finally of teachers' views. Experimental exercises have been executed in an attempt to link the key findings of published research to the local scene. Conclusions are then drawn, and recommendations made for improving three-dimensional graphicacy in South African secondary schools.
- Full Text:
- Date Issued: 1986
Hydraulic vulnerability of Subtropical Thicket to drought : a remote sensing and physiological perspective
- Authors: Buttner, Daniel Harry
- Date: 2022-04
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/55455 , vital:52017
- Description: Water availability is one of largest constraints on plant survival, growth, and species distribution globally. The recent escalation in tree mortality coupled with declining precipitation and amplified temperatures has implicated drought as a major cause behind many large-scale dieback events observed across the world. Raising the question, what makes some species more resistant and persist while others dwindle and vanish from the landscape? The observed variability in species drought susceptibility demonstrates the complexity of physiological responses of plants to changes in water availability. Hydraulic dysfunction in plants has been purported to be the key mechanism behind drought-induced mortality provoking interest in hydraulic traits and critical thresholds of xylem physiological function. The capability of species to maintain hydraulic functionality under drought strongly influences the survival and general productivity towards water deficits. Hence, two core objectives, and subsequently aims, of this thesis are firstly to investigate the effect of drought on Subtropical Thicket vegetation health and productivity, and secondly to examine the underpinning physiological mechanisms and functional thresholds relaying speciesspecific drought vulnerability within this semi-arid biome. In first data chapter, this thesis offers an assessment of vegetation change under drought and its influence on plant physiological function and productivity across a subsection of Subtropical Thicket distribution. Additionally, this chapter provides a regional scale perspective of drought on Subtropical Thicket flora in the Eastern Cape of South Africa. A severe anomalous dieback event, which coincided with extreme, accumulative drought conditions was observed in 2020. Employing a combination of field-based approaches and remote sensing, this chapter aimed to provide a comprehensive report of the extent and severity of crown defoliation and canopy dieback following this event, additionally describing predisposing and compounding factors. Based on Standardized Precipitation Evapotranspiration and Standardized Precipitation Indices this event began in 2015 and coincided with amplified temperatures, exacerbating evaporative demand. Aerial UAV surveys and field-based investigations were undertaken. Remotely sensed (RS) indices provided an avenue for extensive spatiotemporal investigations to uncover the extent of drought-related impact on vegetation productivity and discuss potential underpinning mechanisms behind drought-induced mortality in Subtropical Thicket. Leveraging long-term time series RS data, Normalized Difference Vegetation Index (NDVI) and Enhanced Vegetation Index (EVI), from Moderate Resolution Imaging Spectroradiometer (MODIS) satellites as a proxy vegetation physiological status in combination with SPI and SPEI describing drought condition and groundbased surveying defining canopy vitality condition this study incidentally addressed the aim of endeavoring to link drought-induced mortality and early warning symptoms observed in the field with RS time series data to describe drought impacts across Subtropical Thicket. Furthermore, the findings of this chapter demonstrate the spatial and temporal heterogeneity in drought impacts on Subtropical Thicket. The recent drought of 2015 till 2021 is the longest documented period for the past 50 years in which there has been no accumulated net positive water availability, this apparently perpetual state of water deficiency has enacted a high cost for vegetation productivity and growth for the study area, exhibited well by average NDVI values of less than -0.5 for over 70% of the research site. The findings of this chapter report, to the contrary of anecdotal suggestions in the literature, on the intrinsic tolerance of Subtropical Thicket and that ii drought has a far more significant role on overall vegetation productivity, growth, and mortality in this region. The second data chapter assess whole-plant physiological functionality during a drought event in the Eastern Cape, South Africa. This is the first study in Subtropical Thicket to quantify in situ hydraulic functional integrity under a natural drought event testing the leading hypothesis describing tree mortality – hydraulic dysfunction. This chapter firstly, investigates hydraulic traits (e.g., turgor loss point) and describe key physiological thresholds (e.g., P50) for maintaining function during drought. Secondly, levels of native embolism were determined under drought conditions and combined with measurements of xylem vulnerability to embolism providing an estimation of degree of hydraulic dysfunction experienced by six dominant woody canopy species in Subtropical Thicket – to quantify interspecific drought tolerance and susceptibility. Subtropical Thicket species exhibited remarkable tolerance towards desiccation (TLP from as low as -3MPa) and hydraulic functional resistance to embolism (P50 value as low as -7.89MPa). The observed unexpected drought resilience of subtropical derived lineages highlights the intrinsic evolutionary role aridification had, selecting for greater embolism resistance and community-level conservatism in drought resistance of Subtropical Thicket. The level of native embolism and hydraulic safety margins identified two species (Schotia latifolia and Polyagla myrtifolia) that were the most vulnerable, and a third (Pappea capensis) moderately vulnerable, then the remaining studied species – this could result in community-level adjustments in species composition and structure under future projected climate change scenarios where, increased frequencies of drought events are anticipated. This retrospective assessment of canopy vigor with physiological functional thresholds evokes hydraulic dysfunction as the principal mechanism of observed Subtropical Thicket dieback to drought. This chapter provides crucial in situ data for predictive assertions around drought-induced mortality risk in a phylogenetically diverse and climatically unique biome of southern Africa; and is the first to identify critical hydraulic thresholds for tree species within this region. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Buttner, Daniel Harry
- Date: 2022-04
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/55455 , vital:52017
- Description: Water availability is one of largest constraints on plant survival, growth, and species distribution globally. The recent escalation in tree mortality coupled with declining precipitation and amplified temperatures has implicated drought as a major cause behind many large-scale dieback events observed across the world. Raising the question, what makes some species more resistant and persist while others dwindle and vanish from the landscape? The observed variability in species drought susceptibility demonstrates the complexity of physiological responses of plants to changes in water availability. Hydraulic dysfunction in plants has been purported to be the key mechanism behind drought-induced mortality provoking interest in hydraulic traits and critical thresholds of xylem physiological function. The capability of species to maintain hydraulic functionality under drought strongly influences the survival and general productivity towards water deficits. Hence, two core objectives, and subsequently aims, of this thesis are firstly to investigate the effect of drought on Subtropical Thicket vegetation health and productivity, and secondly to examine the underpinning physiological mechanisms and functional thresholds relaying speciesspecific drought vulnerability within this semi-arid biome. In first data chapter, this thesis offers an assessment of vegetation change under drought and its influence on plant physiological function and productivity across a subsection of Subtropical Thicket distribution. Additionally, this chapter provides a regional scale perspective of drought on Subtropical Thicket flora in the Eastern Cape of South Africa. A severe anomalous dieback event, which coincided with extreme, accumulative drought conditions was observed in 2020. Employing a combination of field-based approaches and remote sensing, this chapter aimed to provide a comprehensive report of the extent and severity of crown defoliation and canopy dieback following this event, additionally describing predisposing and compounding factors. Based on Standardized Precipitation Evapotranspiration and Standardized Precipitation Indices this event began in 2015 and coincided with amplified temperatures, exacerbating evaporative demand. Aerial UAV surveys and field-based investigations were undertaken. Remotely sensed (RS) indices provided an avenue for extensive spatiotemporal investigations to uncover the extent of drought-related impact on vegetation productivity and discuss potential underpinning mechanisms behind drought-induced mortality in Subtropical Thicket. Leveraging long-term time series RS data, Normalized Difference Vegetation Index (NDVI) and Enhanced Vegetation Index (EVI), from Moderate Resolution Imaging Spectroradiometer (MODIS) satellites as a proxy vegetation physiological status in combination with SPI and SPEI describing drought condition and groundbased surveying defining canopy vitality condition this study incidentally addressed the aim of endeavoring to link drought-induced mortality and early warning symptoms observed in the field with RS time series data to describe drought impacts across Subtropical Thicket. Furthermore, the findings of this chapter demonstrate the spatial and temporal heterogeneity in drought impacts on Subtropical Thicket. The recent drought of 2015 till 2021 is the longest documented period for the past 50 years in which there has been no accumulated net positive water availability, this apparently perpetual state of water deficiency has enacted a high cost for vegetation productivity and growth for the study area, exhibited well by average NDVI values of less than -0.5 for over 70% of the research site. The findings of this chapter report, to the contrary of anecdotal suggestions in the literature, on the intrinsic tolerance of Subtropical Thicket and that ii drought has a far more significant role on overall vegetation productivity, growth, and mortality in this region. The second data chapter assess whole-plant physiological functionality during a drought event in the Eastern Cape, South Africa. This is the first study in Subtropical Thicket to quantify in situ hydraulic functional integrity under a natural drought event testing the leading hypothesis describing tree mortality – hydraulic dysfunction. This chapter firstly, investigates hydraulic traits (e.g., turgor loss point) and describe key physiological thresholds (e.g., P50) for maintaining function during drought. Secondly, levels of native embolism were determined under drought conditions and combined with measurements of xylem vulnerability to embolism providing an estimation of degree of hydraulic dysfunction experienced by six dominant woody canopy species in Subtropical Thicket – to quantify interspecific drought tolerance and susceptibility. Subtropical Thicket species exhibited remarkable tolerance towards desiccation (TLP from as low as -3MPa) and hydraulic functional resistance to embolism (P50 value as low as -7.89MPa). The observed unexpected drought resilience of subtropical derived lineages highlights the intrinsic evolutionary role aridification had, selecting for greater embolism resistance and community-level conservatism in drought resistance of Subtropical Thicket. The level of native embolism and hydraulic safety margins identified two species (Schotia latifolia and Polyagla myrtifolia) that were the most vulnerable, and a third (Pappea capensis) moderately vulnerable, then the remaining studied species – this could result in community-level adjustments in species composition and structure under future projected climate change scenarios where, increased frequencies of drought events are anticipated. This retrospective assessment of canopy vigor with physiological functional thresholds evokes hydraulic dysfunction as the principal mechanism of observed Subtropical Thicket dieback to drought. This chapter provides crucial in situ data for predictive assertions around drought-induced mortality risk in a phylogenetically diverse and climatically unique biome of southern Africa; and is the first to identify critical hydraulic thresholds for tree species within this region. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2022
- Full Text:
- Date Issued: 2022-04
Map marking the boundaries of Stellaland and Goshen and showing surrounding areas
- Cape of Good Hope. Ministerial Department of Crown Lands and Public Works
- Authors: Cape of Good Hope. Ministerial Department of Crown Lands and Public Works
- Date: 1883
- Subjects: Griqualand West (South Africa) -- Maps Maps , Goshen (South Africa) -- Maps Maps , Stellaland (South Africa) -- Maps Maps , South Africa
- Language: English
- Type: cartographic , map
- Identifier: http://hdl.handle.net/10962/57431 , vital:26921 , Cory Library for Humanities Research, Rhodes University Library, Grahamstown, South Africa MP416b , MP416b
- Description: Attached to Report of the commissioners appointed to inquire into the question of the northern boundary of Griqualand West : with minutes of evidence, minutes of proceedings, map and plans, Cape of Good Hope Ministerial Department of Crown Lands and Public Works.
- Full Text: false
- Date Issued: 1883
- Authors: Cape of Good Hope. Ministerial Department of Crown Lands and Public Works
- Date: 1883
- Subjects: Griqualand West (South Africa) -- Maps Maps , Goshen (South Africa) -- Maps Maps , Stellaland (South Africa) -- Maps Maps , South Africa
- Language: English
- Type: cartographic , map
- Identifier: http://hdl.handle.net/10962/57431 , vital:26921 , Cory Library for Humanities Research, Rhodes University Library, Grahamstown, South Africa MP416b , MP416b
- Description: Attached to Report of the commissioners appointed to inquire into the question of the northern boundary of Griqualand West : with minutes of evidence, minutes of proceedings, map and plans, Cape of Good Hope Ministerial Department of Crown Lands and Public Works.
- Full Text: false
- Date Issued: 1883
Murraysburg
- Casgrave, P H du P, Great Britain. War Office. Intelligence Division
- Authors: Casgrave, P H du P , Great Britain. War Office. Intelligence Division
- Date: 1900
- Subjects: Eastern Cape (South Africa) , South Africa , History
- Language: English
- Type: maps , digital maps , Maps , cartographic
- Identifier: http://hdl.handle.net/10962/113280 , vital:33741
- Description: [Imperial map of South Africa] : Murraysburg compiled and lithographed by Mapping Section F.I.D. Cape Town under the superintendance of Capt. P.H. Du P. Casgrain ... from farm surveys and all other available information, [Wood and Ortlepp] [1900].
- Full Text: false
- Authors: Casgrave, P H du P , Great Britain. War Office. Intelligence Division
- Date: 1900
- Subjects: Eastern Cape (South Africa) , South Africa , History
- Language: English
- Type: maps , digital maps , Maps , cartographic
- Identifier: http://hdl.handle.net/10962/113280 , vital:33741
- Description: [Imperial map of South Africa] : Murraysburg compiled and lithographed by Mapping Section F.I.D. Cape Town under the superintendance of Capt. P.H. Du P. Casgrain ... from farm surveys and all other available information, [Wood and Ortlepp] [1900].
- Full Text: false
The role of Technical and Vocational Education and Training (TVET) in economic development in the O.R. Tambo Distric Municipality
- Authors: Dandala, Malibongwe
- Date: 2021-04
- Subjects: Technical education -- Economic aspects -- South Africa -- Eastern Cape , Economic development -- Education -- South Africa -- Eastern Cape , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/52413 , vital:43639
- Description: The study aims to understand the practical effects that technical and vocational education and training (TVET) can have on the economic development of OR Tambo District Municipality. The district is situated in an area endowed with numerous natural resources, including fertile land for agricultural augmentation, dairy farming and beef production. This district municipality has a history as the starting point for the liberation of South Africa, where heroes such as the late OR Tambo, Nelson Rolihlahla Mandela, (the first democratic president of South Africa), Walter Sisulu and numerous others were born. The district is situated in the OR Tambo region of the Eastern Cape Province of South Africa. More than five TVET campuses offering training in a variety of skills, such as Engineering and Design, Mechanical and Electrical Engineering, Public Management, Human Recourses Management, Office Practice, Hospitality and Educare are spread across the OR Tambo District. This district also has a burden of high unemployment among the youth, resulting in a high crime rate. A mixed research method was adopted while conducting this study. The study findings found that TVET colleges have a significant role towards economic development of O.R Tambo. TVET colleges are able to supply suitably qualified employable students who have practical knowledge compared to other students from other academic institutions. The students are skilled and semi-skilled can contribute towards socio-economic activities thus contribute towards economic development in O.R Tambo Municipality. , Thesis (MPA) -- Faculty of Humanities, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Dandala, Malibongwe
- Date: 2021-04
- Subjects: Technical education -- Economic aspects -- South Africa -- Eastern Cape , Economic development -- Education -- South Africa -- Eastern Cape , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/52413 , vital:43639
- Description: The study aims to understand the practical effects that technical and vocational education and training (TVET) can have on the economic development of OR Tambo District Municipality. The district is situated in an area endowed with numerous natural resources, including fertile land for agricultural augmentation, dairy farming and beef production. This district municipality has a history as the starting point for the liberation of South Africa, where heroes such as the late OR Tambo, Nelson Rolihlahla Mandela, (the first democratic president of South Africa), Walter Sisulu and numerous others were born. The district is situated in the OR Tambo region of the Eastern Cape Province of South Africa. More than five TVET campuses offering training in a variety of skills, such as Engineering and Design, Mechanical and Electrical Engineering, Public Management, Human Recourses Management, Office Practice, Hospitality and Educare are spread across the OR Tambo District. This district also has a burden of high unemployment among the youth, resulting in a high crime rate. A mixed research method was adopted while conducting this study. The study findings found that TVET colleges have a significant role towards economic development of O.R Tambo. TVET colleges are able to supply suitably qualified employable students who have practical knowledge compared to other students from other academic institutions. The students are skilled and semi-skilled can contribute towards socio-economic activities thus contribute towards economic development in O.R Tambo Municipality. , Thesis (MPA) -- Faculty of Humanities, 2021
- Full Text:
- Date Issued: 2021-04
The aesthetics of hegemony: a speculative design proposal exploring the convergence of surveillance capitalism and brain-computer interface technologies in the future
- Authors: Davies, James Tibbott
- Date: 2021-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/54417 , vital:46517
- Description: This study examines the power dynamics of surveillance capitalism, and its role in shaping cultural hegemony. The research was expressed using graphic design to illustrate a (potential) future where Brain-Computer Interfaces (BCIs) and surveillance capitalism converge. The critique focused on Google and Facebook’s hegemony in the data-surveillance marketplace and what role this has in shaping global discourse. Both companies are funding the development of BCIs, with the aim of using brain signals as a means of interacting with the digital world, which would give the two biggest advertising companies in the world access to new sources of data. A speculative design framework was utilized to visually question the societal implications of this emerging technology and the funding behind its development. A theoretical investigation of the concepts underpinning critical theory and critical design was conducted to help clarify and critically inform this methodological approach, promoting the use of practice-based design as a critically reflective investigative tool. The resulting artefacts designed using this process were showcased in the form of a website and video that act as a visual embodiment the research, demonstrating the efficacy of this approach and the value of using communication design as a mechanism to question the status quo. , Thesis (MA) -- Faculty of Humanities, School of Visual and Performing Arts, 2021
- Full Text:
- Date Issued: 2021-12
- Authors: Davies, James Tibbott
- Date: 2021-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/54417 , vital:46517
- Description: This study examines the power dynamics of surveillance capitalism, and its role in shaping cultural hegemony. The research was expressed using graphic design to illustrate a (potential) future where Brain-Computer Interfaces (BCIs) and surveillance capitalism converge. The critique focused on Google and Facebook’s hegemony in the data-surveillance marketplace and what role this has in shaping global discourse. Both companies are funding the development of BCIs, with the aim of using brain signals as a means of interacting with the digital world, which would give the two biggest advertising companies in the world access to new sources of data. A speculative design framework was utilized to visually question the societal implications of this emerging technology and the funding behind its development. A theoretical investigation of the concepts underpinning critical theory and critical design was conducted to help clarify and critically inform this methodological approach, promoting the use of practice-based design as a critically reflective investigative tool. The resulting artefacts designed using this process were showcased in the form of a website and video that act as a visual embodiment the research, demonstrating the efficacy of this approach and the value of using communication design as a mechanism to question the status quo. , Thesis (MA) -- Faculty of Humanities, School of Visual and Performing Arts, 2021
- Full Text:
- Date Issued: 2021-12