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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
281

Developing a building sustainability assessment model for the South African built environment : searching for new appoaches to improve the effectiveness of building assessment

Kaatz, Ewelina 26 April 2019 (has links)
The fundamental premise of research presented in this thesis is the search for conceptual approaches and practical measures to enhance the practice of building assessment in fostering sustainable construction. Hence, this thesis advances the theory for the practice of building assessment that incorporates the principles of sustainable development. The research findings are communicated via a functional specification for a building sustainability assessment model, suitable to the South African context. The research focuses primarily on process-related aspects of building assessment. Important insights for the development of the model's specification are gained from the review of the practice and experience of Environmental Assessment (EA) in addressing sustainability at a project level. Lessons are also drawn from the Process Protocol (PP), which provides a means of describing the building project process in a way that is transparent and accessible to building stakeholders. The most relevant insights sourced from these two fields of expertise are grouped into three key themes. These include integration (i.e. integration of sustainability principles, stakeholder values and perspectives), transparency and accessibility (i.e. open participation and communication competence) and collaborative learning (i.e. active involvement and transfer of knowledge). It is proposed that these themes form key outcomes of building assessment and be viewed as crucial functionalities of the model. The model is presented as a generic method that can be customised to suit the context of its application. The potential use scenarios of the model, identified in this thesis, include the formulation of a building project proposal, a building project sustainability appraisal and a building performance audit. The use of process maps produced through this research facilitates the identification of interfaces between the model and the building process in terms of decision-points and associated information needs in each use scenario. The model's user personas are also discussed (i.e. building stakeholders) with regard to the potential benefits and challenges of their participation in the building assessment process. The theory for building assessment advanced in this thesis was validated during a workshop with South African academics and built environment practitioners, held at the University of Cape Town. The thesis concludes that building assessment methods can do more than assess the sustainability of a building. More importantly, they provide a means of introducing the principles of sustainable development into the processes that produce the built end-product. This suggests a need to move beyond the terminology of building assessment and instead talk of enhancement models that would facilitate a shift in the practice of building assessment from measuring to one of proactive improvement.
282

Determining the impacts of selected energy policies on Gauteng's residential energy consumption and the associated emissions using LEAP as a tool for analysis : implications for sustainable livelihoods for the poor

Senatla, Mamahloko January 2011 (has links)
Includes abstract. / Includes bibliographical references (leaves 119-126). / Energy is a key factor in economic growth and also central to meeting basic socio-economic goals. The use and production of energy in South Africa is associated with greenhouse gas (GHGs) emissions and pollution problems. Gauteng‘s residential sector is faced with a slowing rate of electrification due to high in-migration rates and high pollution levels in households that use coal to meet their energy needs. This study analyses whether the energy policies in Gauteng can help to steer Gauteng‘s residential sector toward sustainable use of energy by reducing the energy demand and associated GHG and pollutants emissions. Long range Energy Alternative Planning system (LEAP) was used as a tool for analysis.
283

The potential of renewable energy for rural groundwater supply in the Elundini Municipality

Kernick, Gordon January 2014 (has links)
Includes bibliographical references. / The Elundini municipality, situated in the interior Eastern Cape of South Africa, as with many other municipalities with a large portion of rural inhabitants, is beset with the challenge of needing to provide clean drinking water to these far lying people in an efficient and cost effective manner. Due to the large distances between villages as well as from any town or major infrastructure, supplying water via traditional pipe networks is not feasible. Historically, groundwater has been the water source of choice and abstracted via the use of diesel powered borehole pumps. These pumps are however noisy, require constant maintenance and are associated with high running costs associated with the ever increasing price of fuel. Not only is the fuel expensive in itself, but it is also required to be transported long distance to the boreholes on a regular basis. This study then investigated how solar and wind powered borehole pumps compared with diesel powered options. This was done by assessing the natural resource potential of the region (wind and solar power) as well as the groundwater abstraction potential of a sample of villages. Notional solar, wind and diesel powered systems were then designed for each of the villages with each of their unique water supply requirements and then compared against one another with a life cycle cost analysis for each system being performed. The study found that, not unlike other similar studies in other regions of the world, that over their lifetime, wind and solar powered borehole pumps were cheaper than their diesel counterparts. This was especially true for solar powered options as the solar resource for the region is superior to that of wind. Although traditionally shunned due to high capital costs, solar powered pumps have been commercialized in recent years and are now only marginally more expensive than diesel options. Wind pump capital costs are still prohibitively high, although running and maintenance costs are low. For the Elundini municipality however, and its relatively poor wind resources, this would not be a recommended technology.
284

Investigation of the use of biogas in a gas hob - and the feasibility of upgrading it on a household scale

Trautmann, Christina January 2012 (has links)
Incldes abstract. / Includes bibliographical references. / The production and use of biogas on a household scale is becoming more common. The biogas is mainly used for lighting and cooking. Since some households may already be using sophisticated gas appliances prior to investing in an anaerobic digester and might not wish to downgrade to relatively simple and robust biogas appliances, a need to investigate the compatibility of biogas with a standard household appliance was identified. A gas hob was chosen.
285

Global review of CSP technologies

Sikhosana, Qedile January 2011 (has links)
Includes abstract. / This global review of concentrating solar power (CSP) technologies is based mainly on an assessment of available international literature, up to 31 October 2011. It includes a review of major CSP projects currently operating or under development at this time; the respective CSP technologies employed; and an assessment of the present and future economics of CSP relative to other conventional and renewable energy electricity-generating technologies. Global outlook scenarios for CSP are discussed, as well as specific conditions and proposals for CSP developments in South Africa. The economic analysis has been limited by several challenges. Since the CSP industry is new, there are few well-documented projects on which to base the analysis. Most of the projects referenced here are from the USA and Spain. As the CSP market rapidly expands, competition in the industry tends to restrict the disclosure of detailed financial/economic information for projects under development. In general, it has been difficult to compare the publicly available economic data, on a reliable basis, since the financial costing parameters used may vary from case to case. In addition, most of the economic forecasts, which have been reviewed, are based on forward modeling rather than practical proven costs. There are uncertainties and quite wide variations in such predictions. This dissertation concludes, however, that there is great optimism for the growing employment of CSP technology in the near future and that CSP electricity-generating costs, in areas with high solar energy resources, are expected to become competitive with levelised electricity generating costs from other conventional and renewable energy technologies. The cost reduction potentials for CSP lie mainly in expected technical research and development advances, and production economies of scale, achieved by high volume deployment, supported by mid-term investment incentives from governments and other agencies. Another cost reduction potential, especially in the South African context, lies in the localization of skills and local fabrication of some plant structures and components.
286

Reliability investigation of the South African power generation system with the inclusion of wind energy

Maseela, Tiisetso January 2014 (has links)
Includes bibliographical references. / Renewable energy sources such as wind energy for electric power supply are receiving serious consideration around the world due to global environmental concerns associated with conventional generation and depleted conventional energy resources to meet increasing electricity demand. This is more than evident in South Africa, where the recently launched Renewable Energy Independent Procurement Program (REIPPPP) has a proposed capacity of 3725MW, allocating 1850MW to wind energy. This dissertation investigates the effects that geographical dispersion and penetration level have on the wind capacity credit and the reliability of the South African power generation system, by estimating the capacity credit. Some of the estimates are tested using a simplified dispatch model, which is also used to estimate other indicators such as the expected energy not served and CO2 emissions of the system for different wind configurations. The sensitivity of the capacity credit definition is further investigated through two definitions. Several scenarios are used to investigate the capacity credit of wind generation, based on the updated IRP base case scenario.
287

Water resources management in Zambia: a case of cumulative impacts associated with copper mining in the Upper Kafue Catchment, Copperbelt Province, Zambia

Mwamba, Bright 14 September 2021 (has links)
Water resources management is high on the agenda both locally and globally because of its important role in social, economic and environmental development. For example, as part of the 2030 Agenda for Sustainable Development, all United Nations Member States adopted 17 Sustainable Development Goals (SDGs) in 2015 that covered thematic issues including water, energy, climate, oceans, urbanization, transport, science and technology. Sustainable Development Goal (SDG) no.6, which targets universal access to safe and affordable drinking water for all by 2030, is of particular interest in this study. The mining industry contributes to socio-economic development; however, it has also contributed to declining water quality in rivers and lakes in many regions globally. In this study, the status and governance of water resources within the Copperbelt province of Zambia over the period 2000 to 2020 was examined. The study investigated population and economic growth within the region and its correlation with changes in water quality and quantity. The research also focused on understanding the ways copper mining is affecting local water resources. The study also investigated challenges faced by regulators and institutions in the water sector, and considered how these challenges could be addressed. Secondary data was obtained from government institutions within Zambia such as National Water Supply and Sanitation Council (NWASCO), Water Resources Management Authority (WARMA) and Zambia Environmental Management Agency (ZEMA), which are the key institutions in the water sector and the environment. Semi-structured interviews were also conducted with the three key institutions in the water and pollution control sectors. The results showed that the total population in the Copperbelt province has increased by 20% since 2000 to a total of 1 972 317 in 2010. The population is projected to be 2 669 635 in 2020, representing about 27% increase from 2010. The rural population is projected to be 423 511 in 2020, representing about 11% increase from 2010 while the urban population will be 2 246 124 in 2020 representing about 29% increase from 2010. The majority of this growth has occurred in urban areas, which grew by about 30% from 2000 to a total of 1 595 456 in 2010. Rural population has increased by 8% since 2000 to a total of 376 861. The results also showed increased economic activities driven mainly by copper mining. Water abstraction has generally declined since 2000 mainly due to decrease in mining activities. In 2000, about 1 million m3 /day was abstracted in the Copperbelt province and about 600 000 m3 per day in 2005. The reduction in 2005 could be attributed to reduction in mining activities and institutional changes in the water sector. Water production and consumption from commercial utilities has generally been in decline from 2000 to 2017. This is also the case with water consumption per capita and water production per capita. For example, water consumption per capita per day in 2001 was 203 liters and reduced to 113 liters in 2017, representing a 44% reduction in consumption. The results showed that water consumption from 2004 to 2008 averaged 100 million m3 while the production averaged 160 million m3 per year. NWASCO attributed the general downward trend in water production and consumption in the province to maintenance and rehabilitation of water infrastructure, and investment in new infrastructure, thereby reducing the unaccounted-for water. The other reason could be that new housing developments prefer to use groundwater sources rather than utility water (supplied by water companies). The reduction could also be attributed to the cost of water and that consumers needed to adjust from the background where utility services such as water supply and sanitation were the sole responsibilities of the mines (ZCCM), prior to privatization. In terms of water supply and sanitation coverage, there has been an increased coverage since 2000. In 2001, the population that had access to water supply and sanitation was 81% and 46%, respectively. Therefore, roughly 50% of the population had no access to sanitation. However, in 2017 the population with access to water supply and sanitation was 91% and 75%, respectively. This represented only 25% of the population in serviced areas that had no access to sanitation. Between 2007 and 2008, the sanitation coverage had seen a reduction compared to the year 2006. This was due to institutional changes on the Copperbelt province, and the 2008 economic recession – the mine townships that were previously serviced by an asset holding after privatization of the mines were taken over by other utility companies. Consequently, the service delivery in the province initially dropped, but then started increasing again in 2009.
288

Bamboo construction as a sustainable building technology from a structural and materials engineering perspective

Ross, Sheila 15 September 2021 (has links)
The objective of this dissertation is to determine whether bamboo culms or stems are suitable for use as a construction material for permanent structures, from an engineering as well as a sustainability perspective. A secondary objective is to establish whether this would be a suitable building technology for South Africa. The research is desk-top in nature and involves reviewing articles in online journals and publications and collating the information into a coherent form. Eleven species of bamboo commonly used in construction worldwide are selected for investigation of their material and engineering properties. Based on the variations found in the various species of bamboo, approaches to engineering modelling and design of bamboo structures are detailed and discussed. Furthermore, four case studies are presented that illustrate the various areas where bamboo construction is currently used. Finally, research is done regarding the level of the South African bamboo industry, including whether a bamboo species currently exists in South Africa that would be suitable for construction purposes. The preliminary literature review indicated that there is a lack of scientific or structural information regarding bamboo as a building material from an engineering or materials perspective, both globally as well as in South Africa. Although a substantial amount of information was subsequently found on the various aspects of bamboo as a structural material, the information varies widely between sources, which is ascribed to variations in test methods as well as to the location of the species being tested. The design codes and standards from various countries for bamboo design and construction are briefly reviewed. For countries where there is currently no bamboo design code or standard, such as South Africa, it is recommended that the International Standard, ISO 22156, be used as a design basis, using specific material properties relevant to the local species. Many publications state that bamboo is a sustainable building material, comparing favourably with other building materials. However, quantitative proof was found to be either lacking or unclear. Different methods were used in the publications to evaluate bamboo from an environmental perspective, making it difficult to compare and evaluate the different reports and results. However, despite the different methods, it appears that bamboo can be regarded as an environmentally favourable material, provided that local species are used in construction. The four case studies presented demonstrate that bamboo culms are suitable for use in large structures, such as bridges or trusses, as well as for smaller structures such as buildings or houses. They also illustrate the issues that can occur if the design intent is not understood or correctly carried out during construction. South Africa has one bamboo species considered suitable for construction, namely Bambusa balcooa, which is grown in various parts of the country. The properties of the South African plants have not been established as yet. However, theoretical engineering and material properties as determined elsewhere in the world indicate that this is a viable construction material. Further areas of research are the establishment of the material and engineering properties of the local South African bamboo species Bambusa balcooa, as well as further research into the behaviour of bamboo in fire conditions.
289

The impacts and conflicts associated with defunct gold tailings storage facilities in South Africa: A case study of Davidsonville, Central Rand

Nwaila, Phumzile Cynthia 15 September 2021 (has links)
Gold mining generates large quantities of tailings waste. These tailings can have a significant negative impact on the surrounding environment, with concomitant effects on local ecosystems, as well as on human health and quality of livelihoods. The latter is a concern in the Witwatersrand goldfields of South Africa, where communities are located in close proximity to gold mining operations and/or both current and defunct tailings dumps. This research project was, therefore, aimed at developing a better understanding of the facts, perceptions, concerns, and expectations associated with Witwatersrand gold mine tailings storage facilities, and how these are related. In order to fulfil this aim, a desktop study was conducted which involved a detailed review of published academic literature, company reports, newspaper articles, gold mining magazines, and specialist reports with specific emphasis placed on the Central Rand goldfields of the Witwatersrand Basin. Semi-structured interviews were also conducted with representatives from the community, civil society organisations and independent experts, using the defunct Princess gold tailings dump in Davidsonville Suburb (West of Johannesburg) as a case study. The literature review of the study has shown that there is environmental pollution (air, water and soil) due to gold tailings dumps in current and historic gold mining areas. These findings were found to be largely consistent with perceptions and concerns of the community members, civil society organisations and subject matter experts. The long-term impacts of this pollution are not only environmental but cause a huge social burden on health and quality of livelihoods. Not only is dust considered a nuisance, particularly in the windy season, but the dust has been proven to contain crystalline silica and radionuclides. The long-term exposure to this dust can lead to skin problems and respiratory illnesses. There is higher exposure of ambient particulate matter (PM10) in areas around tailings even at distances up to 2 km downwind from the tailings dumps. Acid mine drainage, on the other hand, increases metal load in watercourses and soils, ultimately affecting the ecosystems as the metals are toxic to plants. Metal contamination has adverse impacts on animal and human health. In addition to literature survey, results from the semi-structured interviews revealed that there are conflicts between the communities, government and mining companies, with communities associating their health problems with gold mine tailings. This has led to court cases and gained media attention. The complex relationships between mine waste, the environment, and community health and livelihoods are still not well understood, making it difficult to justify and motivate the implementation of meaningful interventions to mitigate risks associated with gold tailings dumps. To date, little attempt appears to have been made to support community concerns and perceptions with factual evidence and information. Overall, this study has demonstrated the existence of longstanding issues associated with defunct gold tailings dumps and the communication gab that existing between various stakeholders, i.e. community, government and mining houses. These emphases the importance of having adequate remedial actions to prevent further pollution, the need to engage all relevant stakeholders when dealing with gold tailings and implementation of regulatory frameworks associated with gold tailings reclamation and rehabilitation.
290

Assessing the energy implications of exploiting stormwater, through artificial aquifer recharge, as an alternative water source in the Cape Flats, South Africa

Gobin, Aumashvini January 2018 (has links)
South Africa has been facing challenges in both its energy and water sectors over the past few years. They are heavily dependent on each other and a better understanding of the linkages between the two sectors is crucial for sustainable development and planning in both sectors. While the water-energy nexus has been widely explored in developed countries, there is a limited amount of literature found on the significance of the nexus in South Africa. With the current critical drought in the region, alternative water sources are being considered by the City of Cape Town including seawater desalination, water re-use and abstraction of groundwater, to increase potable water supplies. The Cape Flats Aquifer represents a significant water resource for Cape Town and its yield can be further augmented by using artificial recharge with stormwater. Due to the location and water quality of the resource, several possible approaches have been identified for its exploitation. This study investigates quantitatively the energy implications of the three selected approaches in order to exploit the Cape Flats Aquifer as an alternative water source for Cape Town and further provides the potential carbon emissions from their respective energy usages. The three approaches consist of a Centralised Approach to treat the abstracted water for potable uses at two existing Water Treatment Plants (Blackheath and Faure); a Decentralised Approach to supply neighbouring suburbs with minimally treated water for non-potable uses through four proposed treatment plants and a Desalination Approach to treat brackish groundwater to potable quality at a proposed desalination plant. The energy implications of the approaches were evaluated using both direct energy usage during the abstraction, conveyance and treatment stages and the embodied energy of the consumables used during the treatment processes. These were then used to compare the shares of direct electricity intensities and embodied energy intensities of the alternatives at each stage to determine their viability. The individual stages' and overall energy intensities were quantified in form of the total energy required to produce a kl of treated water. The minimum energy required to abstract and convey the water was estimated using basic hydraulic principles. The energy usage at treatment plant levels was computed using the installed electrical capacities at the two existing water treatments for the Centralised Approach while the Decentralised Approach's demand was estimated by determining the treatment processes required to produce non-potable water, which is fit for usage. Energy requirements at the desalination plant were estimated using the salinity levels of the brackish groundwater and target salinity concentration of the treated water. The energy intensities of the approaches were then used as a basis to calculate the current and future electricity costs and their associated carbon footprints using the CSIR (2016) least cost scenario and the IRP (2016) base case future electricity mixes, as the higher and lower threshold for electricity generation costs and carbon emissions. The study found that the electricity intensities of all three alternatives depended significantly on the spatial layout of their respective systems, that is, the topography, distance and extent of their transmission networks. However, the embodied energy intensity of the Centralised alternative was found to be comparable to its electricity intensity, since more chemicals were to purify the water to potable levels. The Decentralised Approach's extensive pumped transmission networks contributed the most to its electricity intensity during the treatment process. The Desalination option was found to be the most energy intensive alternative, with energy intensities ranging from 7.41 to 9.62 MJ/kl, of all three options (1.16 to 1.57 MJ/kl for the Centralised Approach and 3.57 to 7.31 MJ/kl for the Decentralised Approach) and had the highest costs and emissions intensities, mostly caused by the country's coal intensive electricity mix. The Centralised option was found to be the least energy and carbon intensive of the three options and the most viable approach investigated. Desalination, nonetheless, can still considered as an alternative, given the issue of water scarcity, to increase water supplies. Despite its high energy demands, its carbon footprint could potentially decrease with a larger uptake of renewable energy technologies as sources of electricity. The importance of holistic planning across sectors was brought out quantitatively by using current and future water and energy mixes, providing valuable insights on the water-energy nexus, in this study.

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