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Pré-tratamentos e digestão anaeróbia da palha de cana-de-açúcar / Pre-treatment and anaerobic digestion of straw sugarcaneRossi, Eduardo de 19 February 2015 (has links)
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Previous issue date: 2015-02-19 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Considering the growing demand for fuels, particularly liquids, and the possibility of producing renewable fuels using materials previously discarded or underutilized, there is need to develop processes to the use of a material usually discarded and wide availability, especially in Brazil, its straw the sugarcane, which has already ban burning in some Brazilian states, and this maximizes its importance, given the need for allocation. Therefore, this work studied the modification chemical degradation generated by two forms of pre-treatment of straw sugarcane, using citric acid in an autoclave, and urea solution with sodium hydroxide at low temperature. The efficiency of modification of each treatment was followed by Fourier transform infrared spectroscopy and in the UV-visible region. The results showed that there are significant changes in the material studied, with degradation of lignin and hemicellulose and cellulose exposure to hydrolysis later. Spectroscopic techniques were effective in monitoring the changes caused by treatments. Already in the second stage, we attempted to biologically digest this material comparing fresh straw, straw pretreated with acid Citric, pretreated straw with urea and NaOH, and straw with both pre-treatments. Straw is delimited amounts of 0; 2.5; 5; 7.5 to 10% w / w. In all reactors was used 20% v / v inoculum. The inoculum consisted of 30% w / w poultry-to-bed and 70% of ARS. The experiment was conducted with greenhouses kept in mesophilic condition. It can be identified that to apply the pre-treatments proposed in the straw cane sugar, has a significant gain in production biogás.gSVR-1, and the proportions order to produce more biogas indicated when apply pre-treatments are 5 and 7.5% of straw in ARS. While the best results from digestion of straw cane sugar were obtained by pre-treating with acid Citric. / Considerando a demanda crescente por combustíveis, principalmente os líquidos e a possibilidade de se produzir combustíveis renováveis utilizando-se materiais anteriormente descartados ou subutilizados, há necessidade de se desenvolver processos visando a utilização de um material geralmente descartado e com vasta disponibilidade, principalmente no Brasil, a palha da cana-de-açúcar, que já possui proibição de queima em alguns estados brasileiros e isto maximiza sua importância, perante a necessidade de destinação. Para isso, este trabalho buscou estudar a modificação do material por degradação química gerada por duas formas de pré-tratamento da palha de cana-de-açúcar, utilizando-se ácido cítrico em autoclave e solução de ureia com hidróxido de sódio em baixa temperatura. A eficiência de modificação de cada tratamento foi acompanhada por espectrofotometria na região do infravermelho e na região do UV-visível. Digerir biologicamente este material comparando-se palha in natura, palha pré-tratada com ácido cítrico, palha pré-tratada com Ureia e NaOH e palha com ambos pré-tratamentos. Delimitou-se quantidades de palha de 0; 2,5; 5; 7,5 e 10% m/m. Em todos os reatores utilizou-se 20% v/v de inóculo, composto por 30% v/v de cama-de-aviário e 70% de ARS. O experimento foi desenvolvido utilizando-se de estufas mantidas em condição mesófila. Os resultados mostraram que há modificação significativa no material estudado, com degradação da lignina e exposição da hemicelulose e celulose à posterior hidrólise. As técnicas espectroscópicas foram eficientes no acompanhamento das modificações causadas pelos tratamentos. Já em uma segunda etapa. Pode-se identificar que, ao se aplicarem os pré-tratamentos propostos na palha de cana-de-açúcar, há um ganho significativo na produção de biogás em L.gSVR-1, sendo que, as proporções visando produção de metano mais indicadas quando se aplicam os pré-tratamentos são as de 2,5 e 5% de palha em ARS, enquanto os melhores resultados de digestão anaeróbia da palha de cana-de-açúcar foram obtidos ao pré-tratá-la utilizando-se ácido cítrico em autoclave.
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Desenvolvimento de Membranas de Quitosana para Aplicação em Células a combustível / Development of Chitosan membranes for use in fuel cellsLupatini, Karine Natani 22 March 2016 (has links)
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Previous issue date: 2016-03-22 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The biopolymer Chitosan has become object of several studies in recent years as proton conductive polymer membrane of hydrogen into PEM fuel cells. The main reasons are related to the possibility to undergo chemical and physical changes due to amine groups present, and its low cost. The schoolwork testing Chitosan membranes as proton conductivity, generally employ arrays of other polymers together, forming composites with properties better suited for this purpose. Very few schoolwork bother to study the effect of the properties of chitosan on the obtaining of these membranes, and Chitosan membranes are usually employed. The aim of this project was to develop membranes of Chitosan from shrimp shell of fresh water produced in Western Paraná, to be used as electrolyte fuel cells and comparing the results with those presented by the use of commercial Chitosan sample. This schoolwork investigated the influence of degree of deacetylation (GD), molar mass and reticulation of the different samples of chitosan on the performance of the membranes obtained front proton conductivity, water absorption, ion exchange capacity, mechanical strength, XRD and TGA. Chitosan QB, produced in the laboratory, presented desired characteristics of 76% GD and molar mass of 64 kDA. These properties have improved the performance of Chitosan membranes, as well as the crosslinking. The FTIR analysis proved that the crosslinking did not alter the functional groups of Chitosan, while the DRX found that the character of the MQBs became more amorphous than the MQAs and, in general, by the dTG says that the membranes have thermal stability up to 600-700° C, suitable to be applied in CaC. MQB04 and MQB05 membranes resulted in higher conductivity of 1.9 and 1.6 x 10-2 respectively and, in this case, the crosslinking provided better mechanical resistance of up to 45 N to the MQB04 membrane. The protonic conductivity obtained for MQB04 and MQB05 was significant, but still low compared to Nafion®. However, the versatility of Chitosan and the possibility of exploration and chemical modifications of its structure, still making it attractive for the research and development of Proton conducting polymeric membranes with superior performance to found in this schoolwork / O biopolímero quitosana tem se tornado objeto de vários estudos nos últimos anos como membrana polimérica condutora de prótons de hidrogênio em células a combustível do tipo PEM. As principais razões estão relacionadas à possibilidade de sofrer modificações físicas e químicas devido aos grupos amina presentes, e a seu baixo custo. Os trabalhos que testam membranas de quitosana como condutoras de prótons, geralmente empregam matrizes de outros polímeros em conjunto, formando compósitos com propriedades mais adequadas para esta finalidade. Pouquíssimos trabalhos se preocupam em estudar o efeito das propriedades da quitosana sobre a obtenção destas membranas, sendo que normalmente membranas de quitosana comercial são empregadas. O objetivo do presente trabalho foi desenvolver membranas de quitosana extraída de carapaças de camarão de água doce produzidos na região oeste do Paraná, para serem empregadas como eletrólito em células a combustível, comparando os resultados obtidos com aqueles apresentados pelo uso de amostra de quitosana comercial. Este trabalho investigou a influência do grau de desacetilação (GD), massa molar e reticulação das distintas amostras de quitosana, sobre o desempenho das membranas obtidas frente à condutividade protônica, absorção de água, capacidade de troca iônica, resistência mecânica, DRX e TGA. A quitosana QB, produzida no laboratório, apresentou características desejadas de GD de 76% e massa molar de 64 kDA. As propriedades de QB melhoraram o desempenho das membranas de quitosana, assim como a reticulação. A análise de FTIR comprovou que a reticulação não alterou os grupos funcionais da quitosana, enquanto que a DRX constatou que o caráter das MQBs tornou-se mais amorfo que às MQAs. As membranas MQB04 e MQB05 resultaram em condutividades superiores de 1,9 e 1,6x10-2 respectivamente e, neste caso, a reticulação proporcionou melhor resistência mecânica de até 45 N para a membrana MQB04. A condutividade protônica obtida para MQB04 e MQB05 foi expressiva, porém, ainda baixa se comparada ao Nafion®. Entretanto, a versatilidade da quitosana e a possibilidade de exploração e de modificações químicas da sua estrutura, continua tornando-a atrativa para a pesquisa e desenvolvimento de membranas poliméricas condutoras de prótons com desempenho ainda superior aos encontrados neste trabalho
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Microgeração de energia elétrica em uma propriedade rural utilizando biogás como fonte primária de energia elétrica / Microgeneration of electricity on a farm using biogas as a primary source of electricityMarques, Cleber Aimoni 25 January 2012 (has links)
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Previous issue date: 2012-01-25 / The energy is of fundamental importance to society, it is necessary for numerous activities of day-to-day, such as cooking, heating, refrigeration, lighting, among many others. Currently, with increasing population, the increasing use of industrial and agricultural machinery as well as fleet vehicles, there has been an increased demand for energy, especially fossil fuels renewable or not. Due to this growth, social and environmental problems arise because most of the sources used to produce fuel and electricity is produced from fossil fuels (oil, coal, natural gas), and burning these fuels releases various gases that are responsible for air pollution. Many countries have invested in the production of clean and renewable energy. This study aimed to evaluate the production of biogas from pig manure and generate electricity using biogas as a primary energy source. Biogas is produced on a farm located in São Miguel do Iguaçu / PR, which uses two digesters for biogas production, whose conversion into electricity is conducted in a motor-generator of 100 kVA or 76 kW. The biogas production data were collected using a gas meter model Roots Meter Series B3. For monitoring the consumption of biogas (m3 / h), the engine to generate electricity (kWh) used a mass flow transmitter of thermal dispersion model Thermatel TA2. The production of electricity (kWh) on the property was measured with a SMART METER T, which is a meter and recorder portable electrical quantities. For an average number of animals housed 4672 was 553 m3/day of biogas produced, making biogas used to generate 847 kWh / day of electricity. The average specific consumption of biogas in the engine 76 kW generator was 0.68 m3.kWh-1 and with an efficiency of 22.21%. The cost of producing electricity using the biogas was 0.45 R$ / kWh, on the other hand the value of energy paid by the concessionaire is 0.14 R$ / kWh, showing no viability. Moreover it was found that if there is a credit sale carbon and the increased production of biogas energy becomes competitive. / A energia é de fundamental importância para toda a sociedade, pois é necessária para inúmeras atividades do dia-a-dia, como cozinhar, aquecer, refrigerar, iluminar, entre tantas outras. Atualmente, com o aumento populacional, o uso crescente de máquinas industriais e agrícolas e também da frota de veículos automotores, gerou-se um aumento na demanda por energia, especialmente de combustíveis fósseis ou não renováveis. Devido a esse crescimento, surgem alguns problemas socioambientais, pois a maioria das fontes utilizadas para geração de combustíveis e eletricidade é de origem fóssil (petróleo, carvão, gás natural), e a queima desses combustíveis, libera vários gases que são responsáveis pela poluição atmosférica. Muitos países têm investido na produção de energia limpa e renovável. O presente trabalho teve como objetivo avaliar a produção de biogás proveniente dos dejetos suínos e a geração de energia elétrica utilizando o biogás como fonte primária de energia. O biogás é produzido em uma propriedade rural localizada na cidade de São Miguel do Iguaçu/PR, a qual utiliza dois biodigestores para produção de biogás, cuja conversão em eletricidade é realizada num moto-gerador de 100 kVA ou 76 kW. Os dados de produção de biogás foram coletados utilizando um medidor de gás modelo Roots Meter Series B3. Para o monitoramento do consumo de biogás (m3/h), pelo motor para geração de energia elétrica (kWh), utilizou-se um transmissor de fluxo de massa de dispersão térmica, modelo Thermatel TA2. A produção de energia elétrica (kWh) na propriedade foi medida com um SMART METER T, o qual é um medidor e registrador portátil de grandezas elétricas. Para uma quantidade média de 4672 animais alojados foi produzido 553 m3/dia de biogás, sendo esse biogás utilizado na geração de 847 kWh/dia de eletricidade. O consumo específico médio de biogás no motor gerador de 76 kW foi de 0,68 m3.kWh-1 e com uma eficiência de 22,21%. O custo de produção de eletricidade utilizando-se o biogás foi de 0,45 R$/kWh, por outro lado o valor da energia paga pela concessionária é de 0,14 R$/kWh, mostrando que não há viabilidade. Por outro lado verificou-se que se ocorrer a venda de créditos de carbono e a ampliação da produção de biogás a energia torna-se competitiva.
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Microgeração de energia elétrica com gás de síntese de um gaseificador concorrente utilizando Itaúba mazilaurus / Microgeneration of electricity with syngas from a downtraft gasifier using Itaúba mazilaurusChaves, Luiz Inácio 17 September 2012 (has links)
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Previous issue date: 2012-09-17 / The use of biomass as energy source is one of the most promising, because it contributes to reduce emissions of carbon dioxide in the atmosphere and allow the decentralized energy generation. Gasification is a technology of processing biomass
energy into a gaseous biofuel of low calorific value. The gas can be used in Otto cycle engine for power generation in isolated communities. This study evaluated the capacity of the gasification gas in a fixed bed gasifier downtraft of two stages, the wood consumption, the efficiency of the gasifier and the gas consumption and efficiency in apower-generator Otto cycle. The gasifier use was a TERMOQUIP brand, model CD 40. The evaluated power-generator was a BRANCO brand, direct
injection and power of 13 cv coupled to an electric generator of 5.5 cv. The gasification gas was injected into the engine mixed with the intake air. The generator was subjected to loads ranging from 0.5 kW to 2.5 kW, with the aid of a bank of
electrical resistances. The production of gas from the gasifier and gas consumption by the motor were measured by means of a gasometer. The average gas production resulting from the gasification of wood presented during testing was 14.28 m³ hˉ ¹.
Wood consumption averaged 5.61 kg hˉ ¹. The average yield of gas per unit weight was approximately 2.55 m3kgˉ ¹. The gasification efficiency averaged 57.2%. When fed with synthesis gas, the output voltage of the generator was kept within the
standards established by Companhia Paranaense de Energia (Copel, 2008), varying only between 221 and 223 V. For tests with the power-generator the best condition occurred for the highest load, 2.5 kW, where the gas consumption was about 10.6
m³ hˉ ¹ and specific fuel consumption of 4.8 m³ kWhˉ¹. For this condition, the average specific fuel consumption of equivalent wood was 1.9 kg kWh ˉ ¹ and the overall efficiency of power-generator was about 16.6%. / O uso da biomassa como fonte de energia é uma das formas mais promissoras, pois contribui para a redução das emissões de dióxido de carbono na atmosfera e possibilita a geração descentralizada de energia. A gaseificação é uma tecnologia de
transformação energética da biomassa num biocombustível gasoso de baixo poder calorífico. O gás pode ser utilizado em motor ciclo Otto para geração de energia elétrica em comunidades isoladas. Este trabalho avaliou a capacidade de produção de gás de gaseificação em um gaseificador concorrente de leito fixo de dois estágios, o consumo de madeira, a eficiência do gaseificador, a eficiência e o consumo de gás num motor-gerador ciclo Otto. O gaseificador utilizado foi da marca
TERMOQUIP, modelo CD 40. O motor-gerador avaliado foi da marca BRANCO, com injeção direta e potência de 13 cv acoplado a um gerador elétrico de 5,5 cv. O gás de gaseificação foi injetado no motor misturado com o ar de admissão. O gerador foi
submetido a cargas que variaram entre 0,5 kW e 2,5 kW, com o auxílio de um banco de resistências elétricas. A produção de gás do gaseificador e o consumo de gás pelo motor foram medidos por meio de um gasômetro. A produção de gás média resultante da gaseificação de madeira apresentada durante os testes foi de 14,28 m³ hˉ¹. O consumo de madeira apresentou uma média de 5,61 kg hˉ¹. A média de rendimento de gás por unidade de massa foi de aproximadamente 2,55 m3 kgˉ¹. A eficiência de gaseificação média foi de 57,2 %.Quando alimentado com gás de
síntese, a tensão de saída do gerador se manteve dentro dos padrões estabelecidos pela Companhia Paranaense de Energia (COPEL, 2008), variando somente entre 221 e 223 V. Em relação aos testes com o motor-gerador, a melhor condição ocorreu para a maior carga, 2,5 kW, onde o consumo de gás foi cerca de 10,6 m³ hˉ¹ e o consumo específico de combustível de 4,8 m³ kWhˉ¹. Para essa condição, a média de consumo específico equivalente de madeira foi de 1,9 kg kWhˉ¹e a eficiência global do motor-gerador foi de 16,6 %.
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Mapping run-of-river hydropower resource of large catchmentsWalker, Antony David January 2018 (has links)
There is overwhelming scientific evidence that shows the temperature of the Earth's atmosphere is rising at an unprecedented rate. This is attributed to increased levels of greenhouse gas emissions, a large proportion of which originates from anthropogenic combustion of carbon-based fossil fuels for energy. There is therefore a strong argument for the increased role of less environmentally damaging, low carbon energy sources including renewable energy technologies. Run-of-river hydropower is one such renewable energy option, considered more environmentally benign than traditional hydropower which requires the construction of large dams to create a reservoir. The aim of this study was to develop a model to search for, and map, economically viable run-of-river hydropower resource that can function on any global catchment of any size. Development and testing of the model was conducted on China's 2 million km2 Yangtze River drainage basin, the third longest river in the world and a rich landscape for hydropower. A gridded, distributed hydrological model was developed integrating high-resolution meteorological datasets and a digital elevation model (DEM). Using the model, the surface hydrology of the Yangtze catchment was simulated at a timestep of 6 minutes to obtain the mean daily surface runoff for every day from the beginning of 1979 to the end of 2007. Observed river flow data from sub-catchments of the Yangtze were used to calibrate the model by differential optimisation, an evolutionary computation technique. Validation was carried out on a 1.6 million km2 sub-catchment resulting in a mean objective function of 0.95 (where a perfect fit would be 1.0) across 8 objective functions commonly used in hydrology. Catchment wide mean daily runoff data was used to develop flow duration curves across the catchment river network. Virtual power stations were constructed at each river cell, iteratively testing differing scheme configurations, and costed using the RETScreen methodology. A best performing hydropower network was determined by a conflict algorithm, designed to prioritise high profit schemes and to remove lower performing and conflicting schemes. This resulted in a potential run-of-river installed capacity across the Yangtze catchment of 103GW (at 10% discount rate), generating 394TWh per annum. This model would be a valuable tool in finding optimal locations for future hydropower resource.
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The management of renewable energy technologies implementations within a contracting organisation's processesWilliams, Tristan January 2013 (has links)
The construction industry is facing ever more challenging targets to reduce the environmental impact of new-build and refurbishment projects. The construction industry has failed to adopt renewable energy technologies (RETs) into mainstream construction projects; however, this aspect of the construction challenge needs addressing by large contractors. This thesis has established that there is a need to educate contractor personnel in the application and integration of RETs into construction projects to ensure that the construction industry can preserve its legacy for future generations. In order to improve the construction industry s use of renewable energy in building projects, it was necessary to reassess how the industry viewed energy. Contracting organisations have a diverse workforce, a fact established through a company-based desk study, workshops, interviews and surveys; this guided the direction of the project to satisfy the aims and objectives. The initial research findings enabled development of a strategy to improve RET knowledge within a UK contracting organisation. This research has developed trialled and tested a training programme aimed at educating construction professionals on the application of RETs that are relevant to new-build construction projects, and at improving knowledge sharing within a contracting organisation. Training material has been developed that includes six RET handbooks, a sustainability workshop incorporating RETs, an e-learning suite of online modules designed to suit a range of construction disciplines from designers to site-based staff. In addition, the research improved business practice through supporting knowledge share across all business units in addition to identifying the benefits of post-occupancy evaluation. The research has impacted the sponsoring organisation on several business elements including creation of a new business unit to assess completed projects in order to inform design and construction on future projects leading towards improved knowledge management on RETs. The e-learning component uses a combination of graphical imagery, audio voice-overs, knowledge-checks and assessment gathered from active construction projects to enable employees to engage in knowledge and experience sharing on a project-by-project basis, and organisational learning through case studies and post-occupancy evaluation of completed projects. Feedback received from the pilot study of the training materials has been encouraging and positive. While further research is required to measure the long-term effect of the initiative on the workforce population, a six month review suggested that a refresher course is required bi-annually to ensure the workforce score consistent results in the assessment and to update the training with new project experience to share within the organisation. The wider impact on the industry is to showcase the potential learning benefits of post-occupancy evaluation (POE) to contractors and the industry as a whole. The research has highlighted typical industry practice within a contracting organisations regarding knowledge sharing within the company and has demonstrated the improvement on employee knowledge after introduction of a training initiative utilising POE (typically a consultant tool) during the construction phase to prevent re-inventing the wheel . Through regularly and collectively sharing information and project experience, it is envisaged that the full range of contractor disciplines will have increased interaction to ensure all perspectives are accommodated during the design, construction and facility management phases of a building s life cycle.
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Computer aided design of 3D of renewable energy platform for Togo's smart grid power system infrastructureKomlanvi, Moglo January 2018 (has links)
The global requirement for sustainable energy provision will become increasingly important over the next fifty years as the environmental effects of fossil fuel use become apparent. Therefore, the issues surrounding integration of renewable energy supplies need to be considered carefully. The focus of this work was the development of an innovative computer aided design of a 3 Dimensional renewable energy platform for Togo’s smart grid power system infrastructure. It demonstrates its validation for industrial, commercial and domestic applications. The Wind, Hydro, and PV system forming our 3 Dimensional renewable energy power generation systems introduces a new path for hybrid systems which extends the system capacities to include, a stable and constant clean energy supply, a reduced harmonic distortion, and an improved power system efficiency. Issues requiring consideration in high percentage renewable energy systems therefore includes the reliability of the supply when intermittent sources of electricity are being used, and the subsequent necessity for storage and back-up generation The adoption of Genetic algorithms in this case was much suited in minimizing the THD as the adoption of the CHB-MLI was ideal for connecting renewable energy sources with an AC grid. Cascaded inverters have also been proposed for use as the main traction drive in electric vehicles, where several batteries or ultra-capacitors are well suited to serve as separate DC sources. The simulation done in various non-linear load conditions showed the proportionality of an integral control based compensating cascaded passive filter thereby balancing the system even in non-linear load conditions. The measured total harmonic distortion of the source currents was found to be 2.36% thereby in compliance with IEEE 519-1992 and IEC 61000-3 standards for harmonics This work has succeeded in developing a more complete tool for analysing the feasibility of integrated renewable energy systems. This will allow informed decisions to be made about the technical feasibility of supply mix and control strategies, plant type, sizing and storage sizing, for any given area and range of supply options. The developed 3D renewable energy platform was examined and evaluated using CAD software analysis and a laboratory base mini test. The initial results showed improvements compared to other hybrid systems and their existing control systems. There was a notable improvement in the dynamic load demand and response, stability of the system with a reduced harmonic distortion. The derivatives of this research therefore proposes an innovative solution and a path for Togo and its intention of switching to renewable energy especially for its smart grid power system infrastructure. It demonstrates its validation for industrial, commercial and domestic applications.
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Energy poverty and access challenges in Sub-Saharan Africa : the role of regional organizations in overcoming the problemNalule, Victoria January 2018 (has links)
Energy access has gained a lot of attention following the adoption of the Sustainable Development Goals (SDG), which under Goal 7 emphasizes the access to affordable, reliable, sustainable and modern energy for all. Energy is central in addressing the major global challenges of the 21st century, including poverty, climate change, famine to mention but a few; and yet a large number of people especially in Sub-Saharan Africa (SSA) still lack access to modern energy, such as electricity, natural gas and liquefied natural gas (LNG) for lighting and cooking respectively. Initiatives have been taken at an international, regional and national level to address the issue of energy access, however, the problem continues to escalate in SSA. SSA countries have common energy challenges which could be tackled with common efforts through regional cooperation. Achieving cooperative outcomes can be difficult among countries on a bilateral basis. In this regard, the employment of a broader multi-country framework which can be utilized through the existing regional organizations and international organizations might be expected to lead to greater cooperation in the energy sector. This possibility is the springboard for the present research. In this thesis, I identify the key regional energy cooperative mechanisms employed by SSA regional organizations and ask whether these are efficient for tackling the challenge of energy access. The primary contribution of this work is to establish and propose a new method which could be employed by SSA regional bodies in both regulatory and infrastructural energy cooperative mechanisms to ensure that regional efforts are enhanced at the national level to tackle energy access and climate change challenges. I also propose a new definition of energy access which could be employed by regional and international organizations. This is much more than a matter of improving stipulative definitions: it is intended to contribute positively to an ongoing debate on the meaning of energy access and what such access entails.
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The flow of money and interests in policymakingCaliskan, Cantay 27 November 2018 (has links)
This dissertation is comprised of three papers that analyze the relationship between political money, elite interests and policies. Individual papers in this work are connected through this overarching theme and the methodology that is used. Each paper employs statistical methods on large-scale datasets with an emphasis on network analysis. The first paper investigates the relationship between the strength of elite connections and the success of renewable energy and emission reduction policies. Based on an original dataset created from social media accounts of the ministers in 34 countries, this analysis uses a stochastic block model and modularity analysis to compare the strength of connections between different types of elites. The quantitative analysis is complemented by in-depth interviews conducted in seven European countries. The second paper explores the relationship between socio-political capital of state-level American politicians and their agenda holding power in legislation. Using a very extensive dataset on campaign contribution records and state-level bill proposals in the United States, this paper employs survival analysis to explore the aforementioned connection. The third paper is a quantitative description of the large datasets on federal- and state-level campaign contribution records and state-level bill proposals. Using visualization, network analysis, and clustering, the last part of the dissertation uncovers some of the connections between big political donors, parties, private sector, and legislation. The last paper in the dissertation also contains a typological identification section for donors and lawmakers. The goal of the dissertation is to expand the literature on elites, to explore what new stories can be told about political money in the United States, and to make use of large-scale datasets for more conclusive arguments in American politics and policy literature.
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Hosting Capacity for Renewable Generations in Distribution GridsJanuary 2018 (has links)
abstract: Nowadays, the widespread introduction of distributed generators (DGs) brings great challenges to the design, planning, and reliable operation of the power system. Therefore, assessing the capability of a distribution network to accommodate renewable power generations is urgent and necessary. In this respect, the concept of hosting capacity (HC) is generally accepted by engineers to evaluate the reliability and sustainability of the system with high penetration of DGs. For HC calculation, existing research provides simulation-based methods which are not able to find global optimal. Others use OPF (optimal power flow) based methods where
too many constraints prevent them from obtaining the solution exactly. They also can not get global optimal solution. Due to this situation, I proposed a new methodology to overcome the shortcomings. First, I start with an optimization problem formulation and provide a flexible objective function to satisfy different requirements. Power flow equations are the basic rule and I transfer them from the commonly used polar coordinate to the rectangular coordinate. Due to the operation criteria, several constraints are
incrementally added. I aim to preserve convexity as much as possible so that I can obtain optimal solution. Second, I provide the geometric view of the convex problem model. The process to find global optimal can be visualized clearly. Then, I implement segmental optimization tool to speed up the computation. A large network is able to be divided into segments and calculated in parallel computing where the results stay the same. Finally, the robustness of my methodology is demonstrated by doing extensive simulations regarding IEEE distribution networks (e.g. 8-bus, 16-bus, 32-bus, 64-bus, 128-bus). Thus, it shows that the proposed method is verified to calculate accurate hosting capacity and ensure to get global optimal solution. / Dissertation/Thesis / Masters Thesis Electrical Engineering 2018
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