Microrganismos simbiontes são essenciais para a exploração de dietas de baixo valor nutricional, o desenvolvimento, crescimento e a reprodução de seus hospedeiros. Insetos que se alimentam de dieta rica em materiais celulósicos, como é o caso de cupins, apresentam protozoários e/ou bactérias associadas ao trato digestivo que auxiliam na quebra do polímero de celulose e na fixação de nitrogênio. A celulose e a hemicelulose são polímeros estruturais formados por unidades de glicose, sendo a hidrólise desses polímeros de grande interesse industrial para a produção de etanol. O modo mais eficiente de hidrolisar a celulose é pelo uso de enzimas, as celulases. Os cupins apresentam grande eficiência na digestão de celulose e hemicelulose, sendo que a compreensão do processo de digestão de celulose por esses insetos pode facilitar o desenvolvimento de tecnologia mais eficiente para a quebra desse polímero. Assim, este trabalho buscou i) isolar, identificar e caracterizar microrganismos associados ao trato digestivo dos cupins Armitermes euamignathus (Isoptera: Termitidae) e Coptotermes gestroi (Isoptera: Rhinotermitidae); ii) verificar o potencial da microbiota na degradação dos principais componentes da lignocelulose (celulose, xilana e pectina); iii) caracterizar o potencial hidrolítico e determinar as condições ótimas de hidrólise (pH e temperatura das diferentes enzimas produzidas). A análise da microbiota cultivável levou à identificação de 14 filotipos para A. euamignathus e de 11 para C. gestroi, distribuídos nos quatro principais filos, Proteobacteria, Firmicutes, Bacteroidetes e Actinobacteria. A caracterização da microbiota não-cultivável levou à identificação de 17 filotipos em operários e três em soldados de A. euamignathus, enquanto que em C. gestroi foi possível identificar seis filotipos em operários e oito em soldados. O filo Firmicutes foi o mais abundante em A. euamignathus, enquanto Proteobacteria predominou em C. gestroi. O isolamento de bactérias em meio seletivo para degradação de celulose, xilana ou pectina levou à seleção de oito filotipos para A. euamignathus e cinco para C. gestroi. Extratos brutos obtidos do cultivo dessas bactérias apresentaram atividade de hidrólise de pectina e xilana, mas não celulose. Ensaios para otimização das reações de degradação indicaram a presença de enzimas que atuam em diferentes faixas de pH ótimo. Assim, a microbiota associada aos cupins estudados foi bastante diversa, apresentando ainda diferenças entre as diferentes castas desses insetos. Essa microbiota também atua em parte do processo de degradação da celulose, demonstrando o potencial que bactérias associadas ao intestino de cupins podem apresentar para a identificação de enzimas digestivas que possam ser utilizadas no processamento da celulose. / Symbionts are essential for insect hosts as they enhance the nutritional value of their host diets and support host development, growth and reproduction. Insects that feed on diets rich in cellulose, such as termites, exhibit protozoa and/or bacteria within their digestive tract that aid in breaking the cellulose and in nitrogen fixation. Cellulose and hemicellulose are polymers formed by units of glucose, and the hydrolysis of these polymers is of great industrial interest for the production of ethanol. Cellulases are the most efficient enzymes to break cellulose. Termites have a huge capacity to digest cellulose and hemicellulose; thefore, understanding the process by which they digest cellulose may allow the development of more suitable technologies devoted to the industrial utilization of cellulose. This work aimed to i) isolate, identify and characterize microorganisms associated with the digestive tract of Armitermes euamignathus (Isoptera: Termitidae) and Coptotermes gestroi (Isoptera: Rhinotermitidae), ii) investigate the potential of symbionts in the degradation of the main components of lignocellulose (cellulose, xylan and pectin); iii) characterize the hydrolytic potential and determine the optimum hydrolysis conditions (pH and temperature) for the different enzymes produced. The analysis of culturable microorganisms led to the identification of 14 phylotypes for A. euamignathus and 11 for C. gestroi, which were distributed in four Phyla, Proteobacteria, Firmicutes, Bacteroidetes and Actinobacteria. The characterization of the non-culturable microbiota led to the identification of 17 phylotypes in workers and three in soldiers of A. euamignathus, while six phylotypes were identified in workers and eight in soldiers of C. gestroi. Firmicutes was the most abundant in A. euamignathus, while Proteobacteria predominated in C. gestroi. The isolation of bacteria in selective medium to degrade cellulose, xylan or pectin led to the selection of eight phylotypes from A. euamignathus and five from C. gestroi. Crude extracts obtained from the cultivation of these bacteria showed hydrolytic activity towards to xylan and pectin, but not cellulose. Assays for optimization of enzymatic reaction indicated the presence of enzymes that act at different pH ranges great. As a conclusion, symbiont diversity was quite different between the termites species and in between the castes of these species. But the microbiota isolated also acts in the degradation of cellulose, demonstrating the potential for the gut-associated bacteria of termites may present for the identification of digestive enzymes which can be used in the processing of cellulose.

Distributed generation is becoming increasingly prevalent on power grids around the world. Conventional designs and grid operations are not always sufficient for handling the implementation of distributed generation units; the new generation may result in undesirable operating conditions, or system failure. This paper investigates the primary issues involved with the implementation of distributed generation and maintaining the integrity of the power grid. The issues addressed include power flow, system protections, voltage regulation, intermittency, harmonics, and islanding. A case study is also presented to illustrate how these issues can be addressed when designing distributed generation installation on an existent distribution system. The case study design is performed on the campus distribution system of California Polytechnic State University, San Luis Obispo, with the design goal of implementing renewable energy sources to make the campus a net zero energy consumer.

Copper Indium Gallium DiSelenide absorber layers are fabricated using a two step manufacturing-friendly process. The first step involves the sequential deposition of Copper and Gallium and codeposition of Indium and Selenium, not necessarily in that order, at 275o C. This is followed by the second stage, where the substrate is annealed in the presence of Selenium and a thin layer of Copper is deposited to neutralize the excess Indium and Gallium on the surface to form the Copper Indium Gallium diSelenide absorber layer. Elimination of the need for high degree of control and elimination of toxic gases like hydrogen selenide aid in the easy scalability of this process to industry. The performance of CuInGaSe2/CdS/ZnO solar cells thus fabricated was characterized using techniques such as I-V, C-V, Spectral Response and EDS/SEM. Cells with open circuit voltages of 450-475 mV, short circuit current densities of 30-40 mA/cm², fill factors of 60-68% and efficiencies of 8-12% were routinely fabricated. Gallium in small amounts seems to improve the open circuit voltages by 50-100 mV without significantly affecting the short circuit currents and the band gap in Type I precursors. Gallium also improves the adhesion of the CIS layer to the molybdenum back contact. Efforts are also being aimed at improving the short circuit current densities in our high bandgap devices. It is believed that improperly bonded Ga is hurting the electronic properties of the CIGS films. A part of this work involves the reduction of the detrimental effect of Ga on the Jsc's by modifying the base process, so as to improve the homogeneity of the film. The modifications include lowering the Ga level as well as fine-tuning the annealing step. Ar annealing of the samples has also been incorporated. The short circuit current densities have been improved significantly by the above mentioned modifications. At present, the best Jsc's are in the 33-35 mA/cm² range. The Voc's have also been improved by splitting the Ga into two layers and replacing the top Cu layer by a Ga layer. Light soaking studies of the absorber have also been carried out. The baseline Type I process has also been adapted to a new load-locked in-line evaporator system. Device performance dependence on Ga and In thickness as well as the top selenization temperature has been determined in this research. The effect of moisture on the quality of the films has been studied. Bandgap variations due to the presence/absence of Se during the Cu deposition has been investigated. The impact of substrate cleaning/Moly deposition conditions on the device performance has been explored. Insitu Ar annealing studies of CIGS absorbers have been carried out. Alternate buffer layers have been pursued. Devices with Voc's as high as 480 mV, Jsc's as high as 40.7 mA/cm² and fill factors of 66% have been fabricated.

<p>This thesis investigates social impacts of charcoal use in households in the Tanzanian town Babati. In Tanzania a majority of the population use charcoal and firewood as their main energy source. A part from the environmental problems connected to charcoal use; there are also considerable social impacts on women’s daily lives. Cooking and collection of wood fuel are time-consuming and restricts the possibilities for women to work and study. The thesis includes an investigation on how the Tanzanian government tackles problems connected to charcoal use, social as well as environmental. The result shows that the Tanzanian government is working with charcoal related problems to some extent but as previous studies shows there are still more that can be done. The main efforts made concentrate on information campaigns and promotion of more energy efficient equipments. One important problem is however that wood fuel is the cheapest available energy source and hence the incentives to start using other, more sustainable, energy sources are very small. The thesis also investigates possibilities for Babati households to substitute charcoal use with renewable energy sources available in the town. The result shows that the possibilities to use renewable energy currently are very limited and mainly affordable to richer households.</p>

Microgrid is a relatively new concept which has gained significant attention recently due to the increasing penetration of distributed energy sources. It brings many benefits to the traditional distribution system. Couples of microgrid testbeds in the forms of either hardware facilities or software simulation systems have been developed to study microgrid issues in many institutes throughout the world. In the work presented in this thesis, a microgrid system model in PSCAD/EMTDC was developed. The proposed microgrid system includes fundamental power system component models, two renewable energy source models (wind and solar) and one energy storage source model. Different case studies were conducted. The results from the simulation case studies showed that the proposed microgrid system in PSCAD had satisfactory performance under different scenarios with renewable energy sources. The proposed microgrid system model can be used for further research on microgrid issues.

This thesis investigates social impacts of charcoal use in households in the Tanzanian town Babati. In Tanzania a majority of the population use charcoal and firewood as their main energy source. A part from the environmental problems connected to charcoal use; there are also considerable social impacts on women’s daily lives. Cooking and collection of wood fuel are time-consuming and restricts the possibilities for women to work and study. The thesis includes an investigation on how the Tanzanian government tackles problems connected to charcoal use, social as well as environmental. The result shows that the Tanzanian government is working with charcoal related problems to some extent but as previous studies shows there are still more that can be done. The main efforts made concentrate on information campaigns and promotion of more energy efficient equipments. One important problem is however that wood fuel is the cheapest available energy source and hence the incentives to start using other, more sustainable, energy sources are very small. The thesis also investigates possibilities for Babati households to substitute charcoal use with renewable energy sources available in the town. The result shows that the possibilities to use renewable energy currently are very limited and mainly affordable to richer households.

This thesis research aims to develop an improved, efficient, low-capacity heat engine, running on an Organic Rankine Cycle (ORC) to generate power. The ORC is driven by low or moderate temperature heat sources, such as; renewable energy in the form of a hot gas derived from biomass/biogas/biofuel combustion streams, waste heat recovery, process heat recovery, etc. The ORC is more suitable and flexible than a conventional steam Rankine cycle, especially when it is applied to low power range. In this research, an extended surface heat exchanger is used to boil the pressurised working fluid, R134a, using a hot air as heat source. The expander used is a scroll type, coupled to a generator, which is able to produce maximum 1.6 kW output. Experimental data of the heat engine are measured under different operating conditions and utilized in the analysis and comparisons. Power generation under various conditions is investigated in order to determine the optimum performance parameters for the heat engine. The isentropic efficiency of the expander is found to be over 40% and reaches 80% for the improved expansion conditions. For the boiler, it is determined that the overall heat transfer coefficient multiplied with the heat transfer area is around 150 W/K. The energy efficiency of the experimental ORC is around 3% for hot air as the low temperature heat source at about 105oC where exergy efficiency reaches 22%, respectively. / UOIT

The purpose of this paper, “Role of Nuclear Energy in Japan Post – Fukushima: Alternatives and their Impact onJapan’s GHG Emission Targets”, is to emphasize that Japan’s expected new energy policy must be in accordancewith its existing environmental targets with regards to GHG emissions. The main research question is how Japan cancontinue to meet its emissions targets in the aftermath of the Fukushima crisis, where public opinion—gaugedthrough newspaper articles—in Japan has now become outright anti-nuclear, and Japan has become compelled toadopt a new nuclear-free energy policy built around renewable energy. However, given the extremely low share ofrenewable energy in Japan’s existing energy mix, an extremely pro-nuclear government, an influential energy lobbyand an overall lack of suitable infrastructure; this goal does appear ambitious. The framework of analysis in thispaper will be of ‘sustainable development’, entailing an analysis of the three pillars of sustainability – environment,economy and social factors. In addition to these factors, security of supply will also be considered as a vital measureto determine the policy’s overall sustainability. The paper will show that while it is indeed possible for Japan tomeet its GHG emissions targets by replacing nuclear energy with renewable energy, Japan’s ability to deployrenewable energy at such a large scale remains inadequate. Through a comparison with the German experience inrenewable energy, any withdrawal from nuclear energy without properly propping up renewable energy will onlyresult in a greater shift towards primary fossil fuels – jeopardizing Japan’s emission targets, security of supply andincurring heavy import costs to its economy. The result of this analysis is to suggest measures such as an expansiveFeed-in tariff system, grid integration and stability and investment in R&amp;D as major components of a focused andlong term energy policy up till 2030, to promote renewable energy. This paper will also posit steps required toimprove the safety and efficiency of its nuclear reactors during the interim period when renewable energy grows inits share of Japan’s energy mix.

The use of ocean wave energy for electricity production has considerable potential, though it has proven to be difficult. A technology utilizing the heaving (up-and-down) motions of the waves was conceived at Uppsala University in the early 2000´s, and is being further developed for commercial use by Seabased Industry AB. The purpose of this master´s degree project was to increase the knowledge of the environmental performance of Seabased´s wave energy conversion concept and identifying possible areas of improvement. This was done by conducting a life cycle assessment (LCA) of a hypothetical prototype wave power plant. All flows of materials, energy, emissions and waste were calculated for all stages of a wave power plant´s life cycle. The potential environmental impact of these flows was then assessed, using the following impact categories: • Emission of greenhouse gases • Emission of ozone depleting gases • Emission of acidifying gases • Emission of gases that contribute to the forming of ground-level ozone • Emission of substances to water contributing to oxygen depletion (eutrophication) • Energy use (renewable and non-renewable) • Water use The methodology used was that prescribed by the ISO standard for Environmental Product Declarations (EPD) and further defined by the International EPD Programme.The potential environmental impact was calculated per kWh of wave power electricity delivered to the grid. The main result of the study is that the potential environmental impact of a wave power plant mainly stems from the manufacturing phase. In particular, the production of steel parts makes a large contribution to the overall results. Future wave power plant designs are expected to be considerably more material efficient, meaning that there are large possibilities to improve the environmental performance of this technology.

Today many buildings and it´s nearby surroundings are designed to achieve some kind of environmental goal.The issue concerning energy consumption is currently at focus and it is relevant that we start increase the share of renewable energy. Solar energy is an infinite resource and should therefore be considered when selecting an energy supplier.   Uppsala University hospital is facing major restructuring when parts of the existing buildings will be refurbished and a large new building will be constructed. White Architects have developed a study concerning the new building and for some of the existing buildings on the hospital campus. Uppsala County requires tough energy measures and wants the new building to be classified as an eco-building in Whites following work. The classifications will involve high energy source requirements.   This work has been conducted to see if solar power can be envisaged as a supplementary energy source for the University hospital and also to investigate the aesthetic impact of solar cells on the new building. In this report, solar cells integrated on the facade and PV modules on the roofs have been studied. Focus has been to evaluate the potential of what each option can produce and what opportunity they have to become an intrinsic part of the architecture   The type of solar cell module, which in this case study has been proven to generate most electricity is stand-alone modules on roofs. These are however, more difficult to reconcile with the architecture. Solar cells on the facades should therefore still be considered as an alternative application.The result shows that the potential energy that can be generated by solar panels on the new building is large but not in relation to hospital´s electricity use. It is for that reason questionable whether solar installation, applied on the new building, can be seen as a good additional source of energy or if it will more become a matter of public relations.