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
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- 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
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- 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
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- Date Issued: 2014-04
Giving effect to the rights of remand detainees
- Authors: Africa, Nicole Kristy
- Date: 2021-04
- Subjects: Gqeberha (South Africa) , Eastern Cape (South Africa) , Prisoners--Civil rights
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/51205 , vital:43216
- Description: Remand detainees make up a considerable amount of the total prison population in South Africa’s correctional system. Inmates are considered a vulnerable group in our society and the majority have suffered unfavourable life circumstances. Correctional centres are not open establishments and the public is not always aware of the human rights violations that occur in these establishments. The crime rate in South Africa is high and effective means must be taken to ensure the safety of its citizens. Time spent on remand is not viewed as punishment, however it is often met with appalling conditions including severe overcrowding, violence, gangsterism, drug usage, illness, the spread of disease and inadequate infrastructure and resources. This is the reality despite South Africa having one of the most progressive Bill of Rights in the world which guarantees human rights and in addition having a comprehensive Correctional Services legislative framework. Remand detainees are entitled to all rights and protections save for those legally restricted for the purpose of their detention. The court process to determine guilt or innocence is riddled with delays and clogged court rolls which sees matters taking a long time to finalise with time spent on remand regarded as dead time with no opportunities for productive activity. The Canadian position regarding remand detainees was investigated and many similarities were detected with the conditions experienced on remand detention in South Africa. It was found that these challenges are a global issue. This study investigates methods for improvement to the South African remand detainee landscape and highlights reforms that can be undertaken to make South Africa a leader in this arena. , Thesis (LLM) -- Faculty of Law, Criminal and Procedural Law, 2021
- Full Text: false
- Date Issued: 2021-04
Estimating Bayesian tolerance intervals for a two - factor factorial model
- Authors: Besele, Kagiso Francis
- Date: 2021-04
- Subjects: Gqenerha (South Africa) , Eastern Cape (South Africa) , Mathematical statistics
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/52302 , vital:43587
- Description: Quality improvement efforts have become the cornerstone of all manufacturing processes. Quality can be defined in terms of variability reduction, and since variability is a statistical concept, statistical techniques such as statistical quality control present techniques for assessing process variation. Methods such as experimental design provide a way to ascertain factor relationships and give a basis for computing variability that arises from each process variable, ultimately providing a way of calculating total process variability. This in turn results in variance components and eventually variance component estimation. As with any statistical model, estimates may be classified in any one of two ways, point estimates or interval estimates. Interval estimates that provide information about an entire population, and not only information on a few observations from a sample or knowledge about only a population parameter, are known as tolerance intervals. Wolfinger (1998) provided a Bayesian simulationbased approach for ascertaining three types of tolerance intervals using a balanced one-way random effects model. In this study, the method initially proposed by Wolfinger (1998), is extended in order to estimate tolerance intervals for the balanced two-way crossed classification random effects model with interaction. The suggested and derived techniques will be applied to the thermal impedance data initially collected by Houf and Berman (1988), and the method presented by Wolfinger (1998) will be expanded to also include the estimation of tolerance intervals for averages of observations from new or unknown measurements. This Bayesian approach provides a thorough but yet simplistic paradigm to using tolerance intervals in manufacturing settings. , Thesis (MSc) -- Faculty of Science, Statistics, 2021
- Full Text: false
- Date Issued: 2021-04
The concurrent jurisdiction of the high court and labour court
- Authors: Beyleveld, Dominique
- Date: 2021-04
- Subjects: Gqeberha (South Africa) , Eastern Cape (South Africa) , Labor laws and legislation--South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/51191 , vital:43218
- Description: The words “concurrent jurisdiction” essentially means that there is more than one court which has the power to hear a matter and therefore, a party may choose which forum to approach.1 The High Court (hereinafter referred to as “HC”) may exercise jurisdiction, together with the Labour Court (hereinafter referred to as “LC”), in enforcing purely contractual and other common law claims as well as for breach of fundamental rights to which the Labour Relations Act (LRA)2 (or other labour statutes) do not give effect to.3 However, this is not without limitations. The HC and the LC have concurrent jurisdiction over claims relating to the lawfulness of dismissal or other conduct by the parties, whereas all claims based on fairness falls within the exclusive jurisdiction of the LC.4 The practical implication of the approach taken by the Constitutional Court (hereinafter referred to as “CC”)5 is that jurisdiction may, to a certain extent,6 be based on the pleadings, and a litigant may in fact have simultaneous claims arising from the same circumstances.7 However, where the basis of the action and the relief sought is clearly identifiable as being part of the machinery of the Labour Relations Act (hereinafter referred to as the “LRA”) or other labour legislation, then the HC will not have jurisdiction and it is up to the LC to remedy the wrong and give effect to the primary objects of the LRA , Thesis (LLM) -- Faculty of Law, Mercantile Law, 2021
- Full Text: false
- Date Issued: 2021-04
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
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- Date Issued: 2021-04
Linking agrochemical pollution with the aquatic ecological integrity of the Twee River Catchment, Western Cape
- Authors: Brink, Zanné
- Date: 2021-04
- Subjects: Gqeberha (South Africa) , Eastern Cape (South Africa) , Ecological integrity
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/52326 , vital:43588
- Description: This study was initiated in the Twee River system due to the threat posed by agrochemicals on the occurrence of the endemic and endangered fish species found within the catchment. Poor knowledge and understanding of the environmental effects of fertilizers, pesticides and other agrochemicals among small and large commercial farmers within the study area, in combination with their intensive use may have resulted in chemical contamination above environmentally safe concentrations. Numerous studies have highlighted the fact that more research needs to be conducted to identify the key threats to the continued existence of specifically the Critically Endangered Sedercypris erubescens. The overall aim of this study was to determine the spatial and temporal patterns in aquatic ecosystem diversity in the Twee River catchment as indicated by macroinvertebrate and native fish distribution and abundance. It was further investigated if there was a link between agrochemical pollution and the aquatic ecological integrity of the Twee River catchment. Selected sampling sites were identified and sampled to determine the presence and concentration of pesticides entering the water of the Twee River system during run-off and event-based spraying. Furthermore, the effect of these pesticides on the distribution and abundance of the aquatic biota were determined using SASS5 for the macroinvertebrate populations and visually sampling the distribution of the native and non-native fish in the Twee River catchment. This study supports suggestions made by previous studies, that sub-lethal to lethal concentrations of insecticides could be a threat to the long-term survival of benthic macroinvertebrates and potentially the more sensitive endemic fish species within the Twee River system. More focussed research is needed to address impacts of pesticides within this catchment. Agricultural and conservation efforts should be aimed at developing of a shared vision amongst stakeholders, to allow for the longterm conservation of the endemic fish of the Twee River. , Thesis (MSc) -- Faculty of Science, School of Natural Resource Management, 2021
- Full Text: false
- Date Issued: 2021-04
Large mammalian fauna of the Palaeo-Agulhas Plain: predicting habitat use and range distribution
- Authors: Brooke, Christopher F
- Date: 2021-04
- Subjects: Gqeberha (South Africa) , Eastern Cape (South Africa) , Herbivores
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/52332 , vital:43590
- Description: Understanding the variations in structure and abundance of animals and what leads to their distribution within the landscape has captured the attention of ecologists for centuries. Importantly, knowledge of current behaviour of large mammals can be used to inform historic population dynamics and is essential to understanding how early humans used large mammals as a foraging resource. Central to this thesis and improving our understanding of large herbivores is the Palaeo-Agulhas Plain (PAP) where large mammalian herbivores formed a key food resource for early humans. The PAP, now submerged off the southern Cape of South Africa, formed a novel ecosystem during lower sea levels. Characterised by large expanses of nutrient rich grasslands and large grazing herbivores, the PAP stands in stark contrast to the nutrient poor fynbos ecosystems that is in the southern Cape today. In this thesis I focus on the Last Glacial Maximum (LGM; ~20 ka) when the PAP was last fully exposed to answer questions relating to the habitat use and range distribution of large herbivores. Importantly, through the Paleoscape Project, modelled climate, soil and vegetation have made these recreations of large mammals possible. Using modelled climate and vegetation this thesis aims to model the large herbivore communities and understand the influence of early humans on the PAP during the LGM for successful integration into the PaleoscapeABM (the PAP agent-based model). To improve our understanding of large mammals on the PAP I identified five large herbivores that became extinct on the PAP since the LGM and modelled their behavioural and physical traits using k-Nearest Neighbour imputation. I predicted the biomass of large herbivores across the PAP using actual biomass of large herbivores from 39 protected areas across South Africa (spanning five functional groups to include the extinct species) across a rainfall gradient and different biomes. The distribution of large herbivores would likely have been driven by similar top-down and bottom-up drivers we see in large herbivore ecology today. Knowing this, I created a predictive model for large mammals by predicting the probability of occurrence of functional groups of large herbivores in relation to environmental drivers and humans. Results showed that all species (except Antidorcas australis) were adapted to the grassy environment of the PAP and these specialisations likely contributed to their extinction along with changing climates and intensified hunting from humans. When predicting herbivore viii biomass, biome was the most important factor influencing the relationship between herbivores and rainfall. In general, large herbivore biomass increased with rainfall across biomes, except for grassland. Finally, I showed the probability of occurrence of large herbivores was influenced by early humans, water availability and a landscape of fear on the PAP. Through this thesis I have successfully provided detailed accounts of the biomass and probability of occurrence of large herbivores on the PAP. Importantly, this information can be seamlessly integrated into the PaleoscapeABM. Finally, I highlight the importance of this knowledge in understanding early humans, the potential shortcomings of this study and resulting areas where research needs to be focused. , Thesis (PhD) -- Faculty of Science, School of Natural Resource Management, 2021
- Full Text: false
- Date Issued: 2021-04
The impact of the minimum wage in South Africa
- Authors: Brown, Kenrick
- Date: 2021-04
- Subjects: Gqeberha (South Africa) , Eastern Cape (South Africa) , Minimum wage--Law and legislation
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/51202 , vital:43224
- Description: On the 20th anniversary of freedom and democracy in South Africa, the government announced its intention to introduce a national minimum wage. The announcement made it clear that the intention was not to introduce a residual wage floor, but to rather completely transform the country’s inordinately unequal wage structure. “Change will not come about without some far-reaching interventions. … As government, we will, during this term, investigate the possibility of a national minimum wage as one of the key mechanisms to reduce income inequality.”1 Minimum wages are geared towards establishing wage floors, which are the bare minimum that employees are allowed to pay employees. The International Labour Organisation (ILO) describes minimum wages as remuneration that covers the basic needs of workers and their families, taking into account relevant economic factors.2 National minimum wages of course set these minimum wage floors at a national, economy-wide level. In South Africa, the stated purpose of a national minimum wage has the multi-purpose function of setting a national wage floor in order to reduce poverty and inequality in order to transform the inherently unequal wage structure radically that still exists in South Africa post-apartheid. Before 1st of January 2019 when the national minimum wage became effective, South Africa had minimum wages, but this was prescribed per sector of the economy. Particularly in unorganised sectors a nationally set minimum wage increased the scope and ease of enforcement for minimum wages in comparison to sectoral wage determinations. In short, it covers all employees in all industries, whereas sectoral determinations did not. Furthermore, a national minimum wage would be far more easily set to take into consideration broader governmental policy considerations in comparison to diverse, multisector wage determinations that only target the employees and economic considerations of their sector. , Thesis (LLM) -- Faculty of Law, Mercantile Law, 2021
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- Date Issued: 2021-04
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
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- Date Issued: 2021-04
An assessment of different methods for measuring mammal diversity in two Southern African arid ecosystems.
- Authors: Burt, Chloe
- Date: 2021-04
- Subjects: Gqeberha (South Africa) , Eastern Cape (South Africa) , Biodiversity -- South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/52338 , vital:43591
- Description: A current critical environmental problem is the loss of biodiversity. To allow for adaptive management and effective conservation interventions, reliable data needs to be readily available and effectively collected. To gather reliable data, the most appropriate method must be used. The aim of this thesis was to compare the effectiveness and efficiency of different mammal diversity sampling techniques, including discussing specificities and complementarity of each. I also assessed the limitation of methods in terms of the influence of species traits on detectability. I used standard mammal field methods such as block transects, camera traps, track plates, spotlight surveys, mist nets, acoustic surveys, and live traps for a wide range of mammal taxa, and also included the use of local knowledge in the comparison. I assessed the cost-efficiency of each method by determining the cost per species. The efficiency of each method was assessed by observing when the species accumulation curve reached an asymptote. The effectiveness was determined by the species richness and the taxonomic groups the method detected. My results indicated that block transects were the most efficient and effective method to assess species richness. However, a combination of methods allowed for a more comprehensive survey and my results indicate that block transects and live traps were the best combination. It is important to note, not only the effectiveness and efficiency of methods be assessed, but also their limitations. I therefore also assessed the influence of species traits on the detectability of five methods. The species traits that I tested were body size, diet, activity, and if they lived in groups. On both study areas, body size was the main trait that influenced detectability with most field methods. Diet and activity had varying influence on detectability depending on the method. Group living did not significantly influence detectability. Based on my results, I provide guidelines for choosing the most appropriate survey method for targeted studies on mammals in arid ecosystems as well as guidelines for choosing the most appropriate methods for a terrestrial mammal inventory. Survey methods selection and guidelines provided here can allow for effective monitoring and therefore effective and adaptive management and having reliable and repeatable outcomes from surveys. , Thesis (MSc) -- Faculty of Science, School of Natural Resource Management, 2021
- Full Text: false
- Date Issued: 2021-04
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
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- Date Issued: 2022-04
Fragmentation of the Albany Thicket Biome: consequences for the biodiversity and health of thicket vegetation
- Authors: Carvalho, Shandon Luke
- Date: 2021-04
- Subjects: Gqeberha (South Africa) , Eastern Cape (South Africa) , Fragmented landscapes
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/52344 , vital:43599
- Description: The dense impenetrable vegetation of the Albany Thicket Biome is highly resistant to a wide variety of disturbances but, once disturbed, lacks the regenerative qualities that allow it to return to a stable state. Agricultural development is the main cause of degradation in this biome, creating a landscape consisting of patches of thicket vegetation scattered throughout land cleared for crops or transformed through grazing by domestic livestock. The main objective of this study is to determine the health, status and biodiversity of thicket fragments as it relates to elephant impacts. The level of fragmentation and the remaining extent of intact thicket were investigated as its current status is unknown. The findings suggest that the Thicket Biome is highly fragmented as almost 50% of solid thicket has been cleared, transformed or degraded by agricultural or urban development. For Arid Thicket, the level of fragmentation and the remaining extent of intact thicket could not be determined and both could potentially be greater. For the intact thicket of Dune, Mesic and Valley Thicket types, patch sizes ranged between almost 6 and 876 km2 while the weighted mean was between 2 and 251 km2 . Remote sensing methods (NDVI) were used to determine whether the health of thicket could be remotely assessed. The thicket within and beyond the extent of piospheres around watering holes is subjected to different levels of herbivory. These different levels were compared to corresponding NDVI values with the latter accurately measuring the impact of herbivores along a gradient and providing a method to assess the health of thicket vegetation. Ground surveys of the edge effect, along thicket fragments adjacent to open pastures and separated by cut lines, were conducted. Based on these surveys, the extent of the edge effect was established at a distance of 7 m into thicket fragments separated by cut lines but could not be determined for thicket fragments adjacent to open pastures. Ground surveys were also conducted to assess the health of thicket vegetation exposed to different levels of herbivory, including the impact of elephants (Loxodonta africana). Results showed that different elephant densities produced different levels of impact that could be described in terms of changes in species richness, species diversity, plant height and cover, and growth form composition. Lastly, the findings of the health-based assessments were combined with elephant densities to develop a model that could assess the health of thicket vegetation using a range of ecological variables and relate it to an ideal range of elephant densities. This assessment method was tested at the Addo Elephant National Park and results showed that an elephant density of 1 elephant/km2 would maintain the appropriate diversity, structure and composition of thicket. , Thesis (MSc) -- Faculty of Science, Department of Botany, 2021
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- Date Issued: 2021-04
Murraysburg
- 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].
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Techniques of Xhosa music: a study based on the music of the Lumko district
- Authors: Dargie, David John
- Date: 1987
- Subjects: Xhosa (African people) -- Music , Lumko district , Eastern Cape (South Africa) , Xhosa music , Musicology , AbaThembu , Ntsikana , Songs , Musical bows , Overtone singing
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2630 , http://hdl.handle.net/10962/d1001975
- Description: Part 1.Thesis: Chapter 1: The people of the Lumko district (the villages of Ngqoko and Sikhwankqeni) are AbaThembu, mostly of the Gcina clan cluster. Their history has caused them to be linked with (now vanished) San peoples in special ways, which have undoubtedly influenced their music. Chapter 2: The music of these people is centred around their religious and social life. This affects the way they classify their songs; and song classifications (and the way songs are used) affect their performance, in particular, the dance styles associated with the song classes. Chapter 3: A variety of musical instruments is used in the Lumko district, the most important being the musical bows. Once again, the use of these bows gives an insight into the musical influences that have affected the people historically. The ways the bows work are described, as well as ways to play them. Chapter 4: Overtone singing, not previously documented anywhere in traditional African music, is practised in certain ways by these AmaGcina. These, and other vocal techniques, are described. Chapter 5: From the terminology and the methods of conceptualisation about music in the Lumko district, it is possible to gain an insight into a truly Xhosa technical understanding of Xhosa music. Once again a historical insight is gained, because so many of the important terms are KhoiSan words. Chapter 6: A Western technological (i. e. musicological) understanding of the music is also necessary in a study of this nature. This chapter applies musicological concepts to an examination of the relationship between speech and song, of the usages in melody and scale, harmony theory, rhythm, polyphony, song form, instrumental roles and methods of performance. Chapter 7: This is the conclusion of the thesis. It sums up what has been studied: musical techniques, principles, the importance of Ntsikana 's song as a basis for musical comparisons, and the import of the historical aspects of the study - a possible glimpse of the music of the San. PART 2. MUSIC TRANSCRIPTIONS AND DESCRIPTIONS. The transcriptions of 62 songs provide the material for this study. The songs were chosen to represent all the major song classes used in the Lumko district, and to represent all the important music techniques as well. The songs are in fifteen categories. Each song is accompanied by its technical details, and sufficient commentary to make the song transcription intelligible and meaningful. Certain key songs are chosen as type-songs or other special examples, and are used as the bases for discussion on song style characteristics, principles of performance, bow adaptation, and so on. A general Introduction to Part 2 describes and accounts for the method of transcription, and also attempts to make it possible for the score reader not only to analyse, but also to perform the songs. In a further attempt to bring the transcriptions to life, a video recording of certain key songs and techniques, and audio tapes with examples taken from all the songs, accompany this study
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- Date Issued: 1987
Review of the rehabilitation and integration of offenders
- Authors: Darries, Share-Leigh
- Date: 2021-04
- Subjects: Gqeberha (South Africa) , Eastern Cape (South Africa) , Criminals--Rehabilitation--South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/51199 , vital:43219
- Description: “It is said that no one truly knows a nation until one has been inside its jails. A nation should not be judged by how it treats its highest citizens but its lowest ones – and South Africa treated its imprisoned African citizens like animals”.1 The constitutional mandate to ensure the successful rehabilitation and reintegration of offenders into society, upon eventual release falls on the South African Department of Correctional Services (DCS).2 In terms of this mandate, the Department is encumbered with the responsibility to develop programmes which not only addresses criminal conduct but results in the eventual drop of recidivism rates.3 Notwithstanding the Department’s inordinate efforts to discharge its constitutional mandate, recidivism rates continue to be on the rise.4 Built to digress from innate retributive traditions and the concept of punishment, the Department of Correctional Services proffered to alter our realities through the creation of an environment which essentially births different behaviours.5 A task rendered unattainable, as inordinate efforts become frustrated by the realities of prisons and the myth of rehabilitation. Despite having one of the most progressive criminal justice systems in the world, obstinate challenges in South African prisons and an overwhelming prison population make managing and translating its policies into practice all the more difficult.6 With high crime and recidivism rates inundating an already saturated criminal justice 1 Mandela Long Walk to Freedom: The Autobiography of Nelson Mandela (1994) 174-175. 2 Murhula and Singh “A Critical Analysis on Offenders Rehabilitation Approach in South Africa: A Review of the Literature” 2019 12 African Journal of Criminology and Justice Studies 21 21. 3 Ibid. 4 Ibid. 5 Department of Correctional Services “White Paper on Corrections in South Africa” (November 2004) (Republic of South Africa, Minister of Correctional Services)” http://wwww.dcs.gov.za/wpcontent/uploads/2016/08/WHITE-PAPER-8.pdf (accessed 2019-05-6) 5; Wainio “Inside the World’s Toughest Prisons season 3 premiere recap: Costa Rica: Prison on a Knife-Edge” https://www.google.co.za/amp/s/showsnob.com/2018/12/24/inside-the-worlds-toughest-prisonsseason-3-premiere/amp (accessed 2019-05-6). 6 McAree “Prisoner Rehabilitation in South Africa: A case study of Phoenix Zululand’s work in Eshowe Correctional Facilities” 2011 School for International Training 7. ix system, and exposure of minor offenders to hardened criminals become all the more common,7 the vision of translating every offender who walks through the prison gate into corrigible and law-abiding citizens8 become a far-kept dream. Instead, South African prisons become nothing but breeding grounds of criminality, 9 and temporary vessels of human right violations, as an inmates try to come to terms with the fact that their eventual release into society is met with ostracization, destabilized community relations and collateral consequences.10 Since offenders are usually detained for long periods on remand, prisons are innately prevented from becoming correctional centers despite this being a stated aim in the White Paper on Corrections.11 Against this backdrop, the researcher proffers to broaden the perpetual desire to construct a transformed and developed system; one which charts a course from innate retributive traditions to one which births rehabilitated offenders into society. Mindful of the obstinate penal system which undeniably perpetuates colonial structures through dichotomization, this treatise offers an altered reality, a system which respects and promotes the values and rights enshrined in the Constitution of the Republic of South Africa.12 , Thesis (LLM) -- Faculty of Law, Criminal and Procedural Law, 2021
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- 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
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- Date Issued: 2021-12
Interaction and transaction: a study of conciliar behaviour in a Black South African township
- Authors: De Jongh, Michael
- Date: 1979
- Subjects: Social interaction , Conciliary behaviour , Black people , Townships , Port Elizabeth , Eastern Cape (South Africa) , Government , Local government
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2086 , http://hdl.handle.net/10962/d1001603
- Full Text:
- Date Issued: 1979
Coordination polymers for denitrogenation of fuel oils
- Authors: Dembaremba, Tendai O
- Date: 2021-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/53630 , vital:45682
- Description: In this thesis, we present adsorptive removal of nitrogen-containing compounds from fuel oil as an alternative to complement conventional hydrotreatment to obtain ultra-low sulfur and nitrogen levels. This is in cognizance of the challenges nitrogen-containing compounds pose to the hydrotreatment process, particularly their inhibition and/or poisoning of the catalysts used in the process, of which basic nitrogen-containing compounds are the major culprits. Selectivity is the biggest challenge for adsorptive removal of nitrogen-containing compounds. We explore reticular synthesis of metal organic frameworks and the use of coordinatively unsaturated metal sites in 1-dimensional coordination polymers to achieve good selectivity for nitrogen-containing compounds. In the first part of the thesis, reticular synthesis of metal organic frameworks to control the size of the cavity, and strategically use the linkers and metal centres was envisaged. In this work we explored variation of the metal centres in the secondary building units (SBUs of the MOFs as the first step to the testing and implementation of the design strategies. Carbazole, representing carbazoles which the major compounds that remain in hydrotreated fuel, was the target compound. Four MOFs of zinc (Zn-CDC-bpe), copper (Cu-CDC-bpe), nickel (Ni-CDC-bpe) and cobalt (Co-CDC-bpe) based on the formation of a dinuclear metal paddlewheel SBUs with the ligand 9H-Carbazole-3,6-dicarboxylic acid (H2CDC) and occupation of the axial positions of the paddlewheel by 1,2-Bis(4-pyridyl)ethane (bpe) to form porous networks were synthesized. A fifth MOF containing only CDC which forms a [Zn4O(O2C-R)5(O2HC-R)] SBU was also synthesized (Zn-CDC). The ligand H2CDC was inspired by the possibility of improving selectivity for carbazole via π–π interactions through the more preferred parallel-offset stacking as well as the possibility for further substitution of the carbazole N-H to add groups that improve selectivity. The sizes of the MOF cavities can then be controlled by choosing different lengths of ligands analogous to 1,2-Bis(4-pyridyl)ethane (bpe), e.g. 4,4’-bipyridine and pyrazine. All the MOFs showed good selectivity of carbazole. The Zn-CDC MOF also had good selectivity for the basic nitrogen-containing compounds tested: quinoline, isoquinoline, quinaldine and 1-naphthylamine. Its uptake of carbazole was also slightly higher. This was attributed to the presence of an unsaturated Zn site in the SBU. Adsorption in all the MOFs was primarily due to physisorption. It was concluded that the role of the metal centre does not play a significant role in the adsorption of carbazole besides providing a template for reticular synthesis. , Thesis (PhD) -- Faculty of Science, School of Biomolecular and Chemical Sciences, 2021
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- Date Issued: 2021-12