Utilizando um método de integração da área de espectros de energia, medidos a partir da combinação de técnicas de espalhamento em alvos espessos e transmissão, obtivemos a curva de perda de energia de partículas sobre absorvedores de Al, em torno do pico de Bragg, com incerteza entre 2% e 3%. Para tanto, foram realizadas duas medidas do espectro de energia de partículas , espalhadas por alvos espessos, sendo a primeira medida sem absorvedor e a segunda com o absorvedor de Al em frente ao detetor. Através da análise de porções das áreas sob os dois espectros, obtivemos uma curva, praticamente contínua, de perda de energia em função da energia das partículas. Implementamos também uma nova metodologia para a obtenção da curva de poder de freamento, diferente da tradicionalmente utilizada no método de transmissão. Inicialmente, parametrizamos uma curva de poder de freamento, obtida na literatura, utilizando uma expressão conveniente, com 6 parâmetros, que fornece o poder de freamento, em função da energia. Posteriormente, foi realizado um ajuste da curva de perda de energia, através da comparação dos valores teóricos e experimentais, e variando-se os parâmetros calculados anteriormente, através do método de mínimos quadrados, até se obter o melhor ajuste para a curva de perda de energia experimental. Deste modo, são obtidos novos parâmetros, que fornecem agora a curva de poder de freamento experimental. Os resultados obtidos foram comparados com outros resultados experimentais e também com algumas das parametrizações semi-empíricas mais comumente utilizadas. / We present in this work experimental energy loss curves for alpha particles in Al foils around the Bragg peak energy. Our method is based on an integration of the energy spectrum, combining elastic scattering in thick targets with transmission method, providing an almost continuous energy loss curve with $2-3\\%$ precision. To achieve this precision we perform two independent measurements of energy spectra. The first one consist of a traditional elastic scattering measurement in thick foil and the second one consists of adding the absorver foil in front of the detector. The energy spectrum from the second measurement shows a shift to lower energies when compared to the one obtained in the first measurement. Through the analysis of the partial areas under the spectra the energy loss curve can be obtained. We also developed a new method to obtain the corresponding experimental stopping power curve, through a global analysis of the energy loss measurements. First, the stopping power of alpha particles in Al, obtained from the literature is parametrized with a convenient six parameters expression. Then we fit the experimental energy loss curve, with the energy loss derived from the stopping power fit using a chi^2 fitting method. From this fitting procedure we obtain a new set of parameters and the experimental stopping power curve is determined. Our results are compared with other experimental data and semi-empirical parametrization found in the literature.

Utilizando um método de integração da área de espectros de energia, medidos a partir da combinação de técnicas de espalhamento em alvos espessos e transmissão, obtivemos a curva de perda de energia de partículas sobre absorvedores de Al, em torno do pico de Bragg, com incerteza entre 2% e 3%. Para tanto, foram realizadas duas medidas do espectro de energia de partículas , espalhadas por alvos espessos, sendo a primeira medida sem absorvedor e a segunda com o absorvedor de Al em frente ao detetor. Através da análise de porções das áreas sob os dois espectros, obtivemos uma curva, praticamente contínua, de perda de energia em função da energia das partículas. Implementamos também uma nova metodologia para a obtenção da curva de poder de freamento, diferente da tradicionalmente utilizada no método de transmissão. Inicialmente, parametrizamos uma curva de poder de freamento, obtida na literatura, utilizando uma expressão conveniente, com 6 parâmetros, que fornece o poder de freamento, em função da energia. Posteriormente, foi realizado um ajuste da curva de perda de energia, através da comparação dos valores teóricos e experimentais, e variando-se os parâmetros calculados anteriormente, através do método de mínimos quadrados, até se obter o melhor ajuste para a curva de perda de energia experimental. Deste modo, são obtidos novos parâmetros, que fornecem agora a curva de poder de freamento experimental. Os resultados obtidos foram comparados com outros resultados experimentais e também com algumas das parametrizações semi-empíricas mais comumente utilizadas. / We present in this work experimental energy loss curves for alpha particles in Al foils around the Bragg peak energy. Our method is based on an integration of the energy spectrum, combining elastic scattering in thick targets with transmission method, providing an almost continuous energy loss curve with $2-3\\%$ precision. To achieve this precision we perform two independent measurements of energy spectra. The first one consist of a traditional elastic scattering measurement in thick foil and the second one consists of adding the absorver foil in front of the detector. The energy spectrum from the second measurement shows a shift to lower energies when compared to the one obtained in the first measurement. Through the analysis of the partial areas under the spectra the energy loss curve can be obtained. We also developed a new method to obtain the corresponding experimental stopping power curve, through a global analysis of the energy loss measurements. First, the stopping power of alpha particles in Al, obtained from the literature is parametrized with a convenient six parameters expression. Then we fit the experimental energy loss curve, with the energy loss derived from the stopping power fit using a chi^2 fitting method. From this fitting procedure we obtain a new set of parameters and the experimental stopping power curve is determined. Our results are compared with other experimental data and semi-empirical parametrization found in the literature.

To reduce fossil fuel consumption and carbon emission in the building sector, renewable and low carbon energy technologies are integrated in building energy systems to supply all or part of the building energy demand. In this research, an optimal supervisory controller is designed to optimize the operational cost and the CO2 emission of the integrated energy systems. For this purpose, the building energy system is defined and its boundary, components (subsystems), inputs and outputs are identified. Then a mathematical model of the components is obtained. For mathematical modelling of the energy system, a unified modelling method is used. With this method, many different building energy systems can be modelled uniformly. Two approaches are used; multi-period optimization and hybrid model predictive control. In both approaches the optimization problem is deterministic, so that at each time step the energy consumption of the building, and the available renewable energy are perfectly predicted for the prediction horizon. The controller is simulated in three different applications. In the first application the controller is used for a system consisting of a micro-combined heat and power system with an auxiliary boiler and a hot water storage tank. In this application the controller reduces the operational cost and CO2 emission by 7.31 percent and 5.19 percent respectively, with respect to the heat led operation. In the second application the controller is used to control a farm electrification system consisting of PV panels, a diesel generator and a battery bank. In this application the operational cost with respect to the common load following strategy is reduced by 3.8 percent. In the third application the controller is used to control a hybrid off-grid power system consisting of PV panels, a battery bank, an electrolyzer, a hydrogen storage tank and a fuel cell. In this application the controller maximizes the total stored energies in the battery bank and the hydrogen storage tank.

The theme of the diploma thesis is study the influence of structural systems for the energy performance of buildings. The thesis compares designed and measured values of the energy consumption of selected buildings with different bearing structure materials beside the results from numerical modeling of energy consumption.

This dissertation focuses on public diplomacy efforts targeted at persuading other countries to strengthen their domestic and international climate change policies. While previous research on climate diplomacy has addressed the global negotiations extensively, the role of embassies and the interplay between diplomats, their partners and the instruments and storylines they employ, has so far not received the scholarly attention it deserves. This is despite the fact that such behind-the-scenes outreach is one of the most promising tools available to engage other states. The dissertation aims to fill this literature gap by examining climate public diplomacy conducted by embassies and consulates of four EU states: the UK, Germany, Sweden and Denmark. The European Union, and these states in particular, were chosen because they have sought to portray themselves as leaders in tackling climate change while undertaking extensive climate diplomacy. The United States and China were chosen as target states since they have been the main focus of EU climate diplomacy, due to their position as the two largest aggregate contributors to climate change. The dissertation addresses public diplomacy in the field of climate change applied to both the federal/national and subnational levels of governance of these states. The main research question tackled by this dissertation is: What role do embassies and consulates play in climate diplomacy, and how effective is this diplomacy? In answering this, the research focuses on identifying environmental discourses and framings of climate change employed by embassies/consulates for different audiences, and assesses the impact of these frames. A central finding was a strong trade and growth orientation of climate diplomacy. The diplomatic network identified industry, especially fossil-fuel intensive businesses, as allies. Some companies that were embassy partners supported climate denial behind the scenes.