Made available in DSpace on 2014-06-11T19:29:05Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-02-17Bitstream added on 2014-06-13T20:18:51Z : No. of bitstreams: 1 ballottin_dpm_me_araiq.pdf: 2551243 bytes, checksum: 6bc5b0d91a3b15a3677e5d02307c45c8 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A alta demanda de energia no mundo atual, bem como o grande número de problemas ambientais existentes, resultam em uma crescente necessidade por novas fontes de energia, estimulando assim o interesse por fontes alternativas para os combustíveis de origem fóssil. Surge então o Biodiesel, combustível biodegradável derivado de fontes renováveis. No entanto, este biocombustível apresenta certos contaminantes que podem causar sérios danos ao motor e ao ambiente dependente de seus teores. Dentre estes, estão os acilgliceróis, remanescentes da matéria prima para a produção do biodiesel. Por exemplo, a alta concentração destes compostos aumenta a viscosidade do biocombustível, provocando depósitos nos cilindros e nas válvulas diminuindo assim a vida útil do motor. Assim, foi avaliado neste trabalho o comportamento voltamétrico do mono, di e trilinoleato de glicerina através da técnica de Redissolução Adsortiva com Voltametria AC. As curvas analíticas para o mono e trilinoleato de glicerina apresentaram linearidade de 4,0 x 10-8 a 1,6 x 10-6 mol L-1, com limites de detecção da ordem de 10-8 mol L-1. A curva analítica do dilinoleato de glicerina mostrou-se linear de 4,0 x 10-9 a 4,0 x 10-7 mol L-1, com limite de detecção da ordem de 10-9 mol L-1. Os limites de quantificação foram da ordem de 10-8 mol L-1 para o mono e o dilinoleato de glicerina e 10-7 mol L-1 para o trilinoleato de glicerina. Porém, estes não puderam ser determinados simultaneamente e, por isso, utilizou-se um método cromatográfico com detecção eletroquímica para a separação e posterior detecção destes compostos. Os acilgliceróis foram separados em coluna de fase reversa (C-18) operando em modo isocrático com fase móvel tampão fosfato pH 3,0/MeOH 60:40 (v/v) com adição de ácido ascórbico / Currently, the high energy demand in today's world, as well as the environmental problems result in an increased need for developing renewable energy sources, thereby stimulating interest in alternative sources to fossil fuels. Then, Biodiesel comes as a biodegradable fuel derived from renewable sources. However, this biofuel has certain contaminants that can cause serious damage to the engine and the environment if they are present in inadequate amounts. Among these contaminants are the glycerides, remnants of the raw material for biodiesel production. For example, the high concentration of these compounds increases the viscosity of the biofuel causing deposits in the cylinders and valves reducing the engine lifetime. Thus, it was evaluated in this study the voltammetric behavior of glyceryl mono, di and trilinoleate by Adsorptive Stripping technique with AC voltammetry. The analytical curves for mono and tri showed linearity from 4.0 x 10-8 to 1.6 x 10-6 mol L-1, with detection limits of about 10-8 mol L-1. The analytical curve of glyceryl dilinoleate was linear from 4.0 x 10-9 to 4.0 x 10-7 mol L-1, with a detection limit of about 10-9 mol L-1. The quantification limits were in the order of 10-8 mol L-1 for mono and dilinoleate and 10-7 mol L-1 for trilinoleate. However, these could not be determined simultaneously and therefore it was developed a chromatographic method with electrochemical detection for separation and detection of these compounds. The glycerides were separated on a reversed phase column (C-18) operating in isocratic mode with mobile phase pH 3.0 phosphate buffer / MeOH 60:40 (v/v) with addition of ascorbic acid

The economic and environmental benefits secured through the increased integration of photovoltaic (PV) technology into the built environment are undeniable and provide the principal motivation for this research. Present delays in the technology transfer of building integrated photovoltaics (BIPV) can be attributed to the following; material cost, performance guarantee, increased installation complexity and unfamiliar technology. It is well understood that the temperature of a PV material receiving solar irradiation, will increase with solar intensity, while reducing in electrical efficiency. It therefore makes economic sense to minimise the increase in PV material temperature and maximise electrical energy yield. Through the addition of a convecting fluid, flowing over the surface of heated PV material, heat transfer will be induced. With the added benefit of warm air capture from an integrated photovoltaic/thermal (PVT) collector, the economic benefits are increased. But, to ensure maximum utilisation of both thermal and electrical energy production, a significantly more complex control system has to be employed than that for a PV system on its own. Modelling the energy flows within a multifunctional PVT building facade presents a problem of considerable complexity. Previous work in this area has centred on performing finite element analysis of the system in order to find solutions to complex algorithms. It requires considerable computational power to perform these calculations and often the results produced are much more detailed than required. Within this thesis, a fully operational PVT facade model is presented, giving the potential for improved multifunctional facade design. This new model has been developed into a software program for use within the TRNSYS environment. By using the TRNSYS software, a detailed building model has been created and integrated with the new PVT facade model. Simulations were then undertaken to evaluate the energy transfers between internal and external environments and the electrical and thermal energy capturing capabilities of the facade. Simulated results have been evaluated against experimental data taken from a fully operational PVT facade. The results conclude that the presented model simulates the energy flows around, through and within the facade (radiative, conductive, convective and electrical) very well. Performance enhancing development work is due to take place on the operational facade analysed in this work, very soon. This new facade model will be used as a tool to evaluate the proposed changes to the building prior to this development work being undertaken.

Organic Rankine cycles (ORC) have unique properties that are well suited to power generation from low grade heat sources. It is envisaged that a domestic scale ORC Heat Engine can be developed that will be able to run off heat stored in a solar charged rock thermal battery. The use of a thermal battery as the heat source for the ORC system will provide the user with electricity during the day and for a number of hours into the night. The concept presented consists of four key components: rock thermal battery, 1 kW scroll expander, condenser and working fluid pump.

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As global energy consumption levels soar, people seek alternative production from the sun, wind, and water. Of these sustainable technologies, wind arguably proves most efficient in producing large quantities of usable energy. Historically, people harnessed the wind and controlled solar gain through architecture. While the urban application of renewable energy begins to appear in cities, it remains largely as production occurring on the periphery where the most space is available. Citing these fields of production necessitates expanding energy and infrastructure to produce energy where it is needed. What if energy production occurred at the site of consumption? What if production and consumption co-existed equally? What if wind harnessing technologies began to influence architecture? This thesis will study the feasibility and architectural potential for incorporating these renewable technologies into existing urban settings to reduce transmission loss. These buildings will not just be a traditional power plant, but will also teach users about consumption levels, turning the space into a dual-usage program. It is my intention to investigate how buildings can both produce energy and contribute to the public life of cities. / 0 / SPK / specialcollections@tulane.edu

This thesis addresses three economic and social impediments to the successful deployment of community-based micro hydro grids using a case study from the Republic of Kenya. Kenya is one of the countries in Sub-Sahara Africa currently faced with low rural electricity access rates, but with abundant micro hydro resources spread across vast rural locations. Although majority of financial resources are channeled to grid extension in developing countries like Kenya, many rural households still live 'under the grid' because they cannot afford connection fees and/or cost of grid electricity. Such phenomenon has led to innovative solutions such as the concept of Community-Based Renewable Energy Schemes (CRES), facilitating joint exploitation of a local renewable energy (RE) resources. The government of Kenya in partnership with non-state actors set up demonstration points for Community-Based Micro Hydro Schemes (CBMHS) in two locations, and other communities have adopted this model by setting up their own electrification schemes in Kenya. However, the success of such schemes continues to be very limited in Kenya and other developing countries with majority of them disintegrating after few years of operation. This phenomenon is widely documented in literature, and a variety of barriers to success of such schemes continue to be interrogated in both published and unpublished academic literature. There are issues relevant to both establishment and continued operation of such electrification that have not received much scholarly research, but continue to largely limit delivery of sustainable and quality service, as well as hindering scaling up of these potentially useful rural electrification alternatives. These include: a) mismatch between the provided services by such group electrification schemes and the expectations of their consumers b) lack of supportive capacity for joint effort mobilization and capacity for self-governance within such schemes c) unsubstantiated claims of the capability of small scale renewable energy electrification impact on households that make them not to be considered as equally important energy solutions. This thesis makes a threefold contribution to the literature of rural electrification by firstly analyzing preference for properties of decentralized electricity delivery service in a field dominated by utility provided grid solutions. Secondly, the literature on governance of man-made common pool resources (CPR) is extended by providing evidence for the requirements for successful management of a small-scale electricity commons line a CBMHS. Lastly, the study produces reliable evidence regarding immediate or short-term changes to households anticipated from small scale electrification projects. Overall, the study presents lessons on implementing and sustaining rural communities' investments in decentralized RE electrification while demonstrating why such schemes should now form essential part of rural electrification delivery models. The three research issues are addressed independently in three chapters that follow the introductory chapter of this thesis.

A dissertation submitted to the Faculty of Arts in partial fulfillment of the requirements for the Degree of Masters in Communication Science in the Department of Communication Science at the University Of Zululand, 2017 / Renewable energy is considered to be a viable and cost-effective solution to the problem of providing electricity to rural regions in many developing countries. The infrastructure challenges experienced by South Africa’s energy parastatal Eskom in providing a stable and affordable electricity supply to the country is compounded by criticism of Eskom’s continued use of coal-powered stations. The King Cetshwayo District has a high unemployment rate, with thousands of rural residents living in poverty, without access to water or electricity. The possibility of utilising organic waste to create biogas is an untapped market that would provide many advantages for rural dwellers. From a communications perspective, this study analysed how communications theories could be utilised to stimulate interest in renewable energy. The feasibility of using renewable energy as a source of electricity for households was considered, while the potential for job creation and other economic activities emanating from the production and sale of biogas was also examined. The study examined how the proximity of cattle herds on a substantial proportion of rural land could offer the opportunity to access animal waste, which is a core fuel source for biogas. If communities are amenable to the concept of a cheap and environmentally-friendly energy option, it would mean huge implications for the future of creating a green economy in the region. The research has found that biogas can also be bottled and sold at a fraction of the cost of purchasing conventional grid electricity. This will mean cost-savings for poor households as well as job creation for entrepreneurs who preserve and sell the gas. The study delved into the socio-economic advantages of using green energy in the King Cetshwayo District and the reasons why communication theories and strategies are critical to the further progress of renewable energy projects in the district.

Many settlements in Sub Saharan Africa (SSA) lack access to electricity which is a necessary resource for development. Given the geography and population patterns in the region, extending national grids is economically unviable for many of the un-electrified settlements. Meanwhile the region is endowed with renewable resources which can be exploited in off-grid mode for electricity generation. This thesis examines the importance of off-grid technologies for onward electrification in the SSA region. The exercise inspires an electricity planning problem that can be analytically specified but is computationally intensive and impractical for real sized problems. Heuristic methods must therefore be used. We develop two new heuristic solution methods which draw on standard algorithms i.e. lexicographic algorithm and genetic algorithm to solve the problem. The new solution methods together with two existing heuristic algorithms in the literature are applied to a case study of Ghana. We find that the electrification schemes yielded by all four solution methods/algorithms suggest off-grid technologies, especially solar, are important for onward electrification in SSA. Locations that were assigned off-grid technologies in the algorithms mentioned above are typically rural where livelihoods are based on small scale farming. Currently, adoption of renewable resource technologies is low in these locations. We therefore develop a dynamic stochastic farm household model to examine the extent to which market failures impact self-funded investment in solar panels by farmers in rural SSA. We find that credit restrictions and risk affect solar panel investment to varying degrees. Using simulations of the policy functions, we find that the expected investment cycle for a credit constrained household in a stochastic farm income environment is 30 years if investment in solar panels is irreversible. In a reversible investment scenario, the expected investment cycle is 5 years only. Reversibility is therefore a major determinant of solar panel adoption among poor farmers.

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No description available.