Yes / Solar energy, amongst all renewable energies, has attracted inexhaustible attention all over the world as a supplier of sustainable energy. The energy requirement of major seawater desalination processes such as multistage flash (MSF), multi-effect distillation (MED) and reverse osmosis (RO) are fulfilled by burning fossil fuels, which impact the environment significantly due to the emission of greenhouse gases. The integration of solar energy systems into seawater desalination processes is an attractive and alternative solution to fossil fuels. This study aims to (i) assess the progress of solar energy systems including concentrated solar power (CSP) and photovoltaic (PV) to power both thermal and membrane seawater desalination processes including MSF, MED, and RO and (ii) evaluate the economic considerations and associated challenges with recommendations for further improvements. Thus, several studies on a different combination of seawater desalination processes of solar energy systems are reviewed and analysed concerning specific energy consumption and freshwater production cost. It is observed that although solar energy systems have the potential of reducing carbon footprint significantly, the cost of water production still favours the use of fossil fuels. Further research and development on solar energy systems are required to make their use in desalination economically viable. Alternatively, the carbon tax on the use of fossil fuels may persuade desalination industries to adopt renewable energy such as solar.

Energy efficiency in the building sector is crucial for many countries in succeeding with the completion of goals regarding energy efficiency. This study has investigated if there are any possible and reasonable solutions for Attefallshus in Sweden to meet the demands of the National Board of Housing regarding energy performance in houses. By building a model and calculating the annual energy usage for a specific Attefallshus, through simulations with the software IDA ICE and general input, an energy audit has been obtained. By comparing the specific energy usage for the studied case with the requirement the conclusion that it is possible for this small building to achieve a low enough energy usage to meet the demand. Solar cells are the key to accomplish the target of a low specific energy usage and by combining this with an effective system for heating it possible to get under the limit. The usage of domestic hot water is a very large part of the building specific energy usage and alone almost reaches the set bounds which is why it is of great importance to carefully design systems and to regain heat with effective ventilation. A large part of the energy usage in Attefallshus is related to the user why awareness and careful usage of energy is a significant factor in reaching a low specific energy usage.

The purpose of this research was to observe the removal efficiency for copper (Cu), nickel (Ni), and zinc (Zn) using Electrocoagulation (EC) technique in a continuous flow reactor with a synthetic bilge water emulsion; and additionally, to discuss the operation cost of the treatment. The optimal configuration for EC treatment used combined electrodes, aluminum and carbon steel; flow rate of 1 L/min; effluent recycling and 7.5 amps; this optimal configuration achieved 99% of zinc removal efficiency, 70% of both, copper and nickel removal efficiency, and low operation costs. The current intensity did not have significance incidence on the removal efficiency. The analysis of cost per gram of removed contaminant indicated that nickel had an average cost of $1.95 per gram removed, zinc and copper had $0.60 and $0.88 per gram removed, respectively. To develop additional experiments with the EC reactor are required in order to optimize metal removal efficiency.

[pt] As atividades de perfuração e completação de poços de petróleo são as que mais demandam tempo e dinheiro entre os mais variados processos que compõem os sistemas de exploração e produção de óleo e gás. Por isso, qualquer avanço nessa área poderia representar valores bastante expressivos em uma indústria de bilhões e com investimentos cada vez maiores. Partindo desse princípio, há uma linha de pesquisa, iniciada em 1997 pelo Gas Technology Institute, que estuda a aplicação de lasers de alta potência nos processos de construção de poços. Desde então, vários experimentos que destacaram as potenciais vantagens do laser em relação aos sistemas convencionais foram realizados. Tomando como base essa premissa, o objetivo desta dissertação é aprofundar os estudos acerca da interação entre laser e rocha. Existe um interesse especial deste trabalho relacionado ao pré-sal brasileiro, por isso a maioria dos experimentos foi feita com a utilização de rochas carbonáticas. Assim, foram realizadas análises de eficiência por meio dos conceitos de energia específica. Além disso, abordou-se a perfuração também de forma dinâmica, baseado em estudos de energia específica de corte. Essa consideração foi feita com o intuito de se alcançar maiores diâmetros comparados às pequenas dimensões geradas pelo feixe do laser em processos estáticos. A ideia é fornecer maiores informações resultantes desses processos e contribuir para que seja estudada a viabilidade no desenvolvimento de futuras ferramentas a laser. / [en] Within the petroleum exploration and production process, well drilling and completion are the activities that require a greater investment of both time and money. Because of this, any evolution in this area could represent significant values within this billion dollar industry which has continuously growing investments. Thus, the Gas Technology Institute started a line of research in 1997, which studies the high power laser application in the well construction process. Since this study, many experiments have been realized, which have highlighted the laser potential advantages compared to the conventional systems. Accordingly, the intention of this work is to further these studies of the interaction between laser and rock. There is a special interest in Brazilian pre-salt and because of this, most experiments were conducted using carbonate rocks. Therefore, efficiency analysis was made based on the specific energy concept. In addition to this, drilling was also approached as a dynamic process using the specific kerfing energy study. This consideration was made with the objective of achieving higher diameters compared to the small dimensions that are created by the laser beam in static process. These experiments have been conducted with the intention of generating and contributing even more information, thus, we can better study the development feasibility of future laser tools.

The municipality of Uppsala together with eight constructors are currently planning a sustainable residential area in Östra Sala backe. The aim of this report is to identify the main factors that are important when calculating the specific energy use in an apartment building. Two previous similar projects, Västra Hamnen in the city of Malmö and Hammarby Sjöstad in the city of Stockholm, are studied and simulations in VIP-energy are performed. Sensitivity analyses concerning the indoor temperature, the efficiency of FTX-systems and the U-values of windows are also executed. The simulations are based on information from the constructors of Östra Sala backe, standard values and mean values from Västra Hamnen and Hammarby Sjöstad. The results show that differences between the estimated and measured values in specific energy use can reach about 50 %, or 25.2 kWh per m2 ATEMP and year, and that the efficiency of the FTX-system is the most important parameter.

This study was undertaken to develop an analytical model that is capable of predicting the torque requirements of a rotavator fitted with commercially available L-shaped blades. An analytical approach based on the limit equilibrium analysis was used to develop the proposed model. The proposed model was verified by comparing the model and measured torque requirements at predetermined rotavator blade angular positions from the horizontal for a down-cut rotavator. The study findings indicated that there was an optimum set tillage depth for each rotavator configuration and operational conditions at which the resultant horizontal thrust generated was greatest. This unique depth was influenced by the bite length. The validation of the proposed model showed that the predicted and measured torque requirements, at different angular blade positions from the horizontal, correlated reasonably well for all the set tillage depths. As the depth of tillage increased, however, the curve for the measured torque requirements exhibited a cyclic behaviour after the peak torque requirements value had been recorded. The cyclic behaviour was probably due to the re-tilling and the instability of the tool-frame carrier, which increased with the set tillage depth. The knowledge contributed by this research will afford the designers of active tillage tools a better understanding of the operations of the rotavator, particularly in deep tillage. The modelling approach, and instrumentation technique used in this research, can be extended to analyze the performance of rotavators fitted with other types of commercial blades. / Thesis (PhD)--University of Pretoria, 2010. / Civil Engineering / unrestricted

[pt] Neste estudo é apresentada a análise da interação da luz laser de alta potência com rochas nos processos de perfuração por fragmentação térmica. O objetivo principal do trabalho é estabelecer, através de um estudo experimental, a possibilidade de utilizar a tecnologia a laser na perfuração de rochas duras, tais como o granito, quartzo, entre outros. Sua motivação encontra-se na aplicação de novas tecnologias para desenvolver ferramentas que melhorem a eficiência no processo de perfuração de poços (maior taxa de penetração), e conseguir retirar a maior quantidade de material fragilizado pela irradiação do laser. Para isto, foi necessário fazer uma montagem opto–mecânica envolvendo um sistema de limpeza que ajudasse a remover o material fragilizado pela ação do laser, usando-se gás de nitrogênio a alta pressão. Foram analisados diferentes intervalos de tempo de exposição da radiação do laser nas rochas, para avaliar a taxa de volume retirado, e a quantidade de energia específica requerida para perfurar diferentes materiais, em função da potência e do tempo de irradiação do laser. Seguindo a revisão bibliográfica na seleção do material, foram escolhidos três tipos de materiais (granito branco, granito cinza e travertino) conhecidos comercialmente no Brasil e que têm similitude (na composição química) com as rochas encontradas nas formações do Pré-sal. A partir desta seleção, foi indispensável conhecer a composição química dos materiais através de fluorescência, raios X, e Microscopia de Varredura (MEV). Além disso, estudou-se o comportamento termomecânico das rochas carbonáticas através de análises térmicas (Termogravimetria e Análise Térmico Diferencial), para identificar e compreender os fenômenos envolvidos no processo de perfuração. Os resultados obtidos são analisados para parametrizar as variáveis em consideração, melhorando as condições do processo de perfuração por fragmentação térmica, dependendo do material estudado. / [en] This study presents the analysis of the interaction of high power laser light with rocks in thermal fragmentation drilling processes. The main objective of the work is to establish, through an experimental study, the possibility of using laser technology in the drilling of hard rocks, such as granite, quartz and others. The motivation is the application of new technologies to develop tools that improve the efficiency in the well drilling process (higher penetration rate), and to be able to remove the largest amount of material weakened by laser irradiation. For this, it was necessary to make an opto-mechanical assembly involving a cleaning system that would help to remove the material weakened by the action of the laser, using nitrogen gas at high pressure. Different exposure time intervals of laser radiation in the rocks were analyzed to evaluate the volume rate removed and the amount of specific energy required to drill different materials, depending on the power and irradiation time of the laser. Following the literature review in selecting the material, three types of materials (white granite, gray granite and travertine) known commercially in Brazil and that are similar (in chemical composition) to the rocks found in the pre-salt formations were chosen. From this selection, it was essential to know the chemical composition of the materials through fluorescence, X-rays, and Scanning Microscopy (SEM). In addition, the thermomechanical behavior of the carbonate rocks wasstudied through thermal analysis (Thermogravimetry and Differential Thermal Analysis) to identify and understand the phenomena involved in the drilling process. The results obtained are analyzed to parameterize the variables under consideration, improving the conditions of the drilling process by thermal fragmentation, depending on the material studied.

This thesis dwells on program creating in program environment Excel, in accordance with submission from submitter. Program is going to be able solve all required values. This thesis has four parts. First part is oriented on problems of urban mass transportation a methods of specific energy consumption. Second part contains program flowchart and program description. Third part contains theoretical solution of specific energy consumption and theoretical comparison of computing methods. Last part contains numerical substitution in an equations and calculating of their values.

Dans l’optique de la conception et du développement d’un siège aéronautique et afin derespecter la règlementation sécuritaire en vigueur, la structure du siège développé doitpermettre une dissipation rapide de l’énergie perçue en cas de crash aérien (Fig. 1), ceci dansle but de protéger les passagers. La majorité des systèmes intégrés à la structure des sièges etpermettant cette absorption d’énergie (Fig. 2) est constituée de composants métalliques qui sedéforment plastiquement pour dissiper l’énergie due au crash. Actuellement, l’industrie et larecherche se tournent vers les matériaux composites pour substituer de tels systèmes.Cependant le comportement de ces matériaux lors de sollicitations mécaniques sévères estfortement différent des matériaux métalliques, notamment dû au fait que les mécanismesd’endommagement sont très distincts.Le but de cette étude portant sur des structures tubulaires composites est d’évaluer leurcapacité à dissiper l’énergie. A cette fin, différentes stratifications ont été testées encompression (Fig. 3 et 4) dans le but de déterminer leur comportement, comparer leurspropriétés et calculer leurs valeurs de SEA (absorption d'énergie spécifique, en kJ.kg-1)servant à évaluer leur aptitude à dissiper l’énergie engendrée en cas de crash. Ces dernièressont issues des courbes effort-déplacement obtenues lors des essais d’écrasement (Fig. 5). Lesdifférents essais de compression ont été instrumentés et suivis au moyen de caméras rapides etdes images post-essais ont été réalisées par tomographie pour comprendre les mécanismesd’endommagement mis en jeu (Fig. 4 et 6). Ces essais ont été réalisés à vitesse de chargementquasi-statique puis dynamique et selon diverses conditions limites. Les différents résultats decomportement en compression sont également utilisés dans le but de construire et enrichir unmodèle de calcul par éléments finis (Fig. 7 et 8) permettant de simuler la réponse de structurescomposites de différentes natures soumises au crash en intégrant la géométrie et lacomposition de la structure (Fig. 8).L’objectif de ce travail de recherche est ainsi d’évaluer l’énergie pouvant être dissipée par desstructures tubulaires composites, de comparer les absorptions induites par des structurescomposites de compositions différentes, et/ou bi-matériaux, et enfin de fournir un modèleéléments finis représentant le comportement de structures composites en compression jusqu’àl’endommagement et la ruine de la structure.Il a ainsi été établi qu’en chargement statique, un stratifié unidirectionnel orienté à 0° etstabilisé par des plis de tissus répond fortement aux attentes en terme de dissipation d’énergie,mais pas en sollicitation dynamique. Dans ce cas, une stratification à 90° semble plusadéquate. D’autre part, un confinement forcé vers l’intérieur est avantageux dans la plupartdes cas, réduisant le pic d’effort initial sans diminuer drastiquement la valeur de SEA. / With the perspective of the design and development of an aircraft seat and in order to respectthe safety regulations in effect, the structure of the developed seat must allow for a swiftdissipation of the energy received in the event of an aircraft crash (Fig. 1) so as to protect thepassengers. The majority of systems integrated into the seats structure and allowing energydissipation (Fig. 2) consists of metal components that sustain plastic deformation to dissipatethe energy induced by the crash. Currently, industry and research sectors are turning theirfocus towards composite materials to substitute such systems. However, the behavior of thesematerials during severe mechanical stress is strongly different from metallic materials, inparticular due to the fact that damage mechanisms are very distinct.The purpose of this study on composite tubular structures is to evaluate their ability todissipate the energy. To this end, different laminate structures were tested in compression(Fig. 3 and 4) in order to identify their behavior, compare their properties and calculate theirSEA value (Specific Energy Absorption, in kJ.kg-1) used to evaluate their capacity to dissipatethe energy generated during a crash. Those are resulting from the load-displacement curvesobtained during the crushing tests (Fig. 5). The various compression tests were instrumentedand monitored by means of rapid imaging cameras and post-crushing tomographic imaginghas been realized in order to understand the damage mechanisms involved (Fig. 4 and 6).Testing has been carried out under quasi-static and dynamic loading and using severalboundary conditions. The different results of compression and crushing behavior are also usedin order to build and improve a finite element calculation model (Fig. 7 and 8) allowing tosimulate the response of composite structures of different natures subjected to crash byintegrating the geometry and the composition of the structure (Fig. 8).The objective of this research work is thus to evaluate the energy that can be dissipated bycomposite tubular structures, to compare the absorption values induced by compositestructures of different compositions, and/or bi-materials, and, finally, to provide a finiteelement model representing the behavior of composite structure submitted to compressionuntil damage and fracture of the structure.It has consequently been established that in static loading, a unidirectional laminate orientedat 0° and stabilized by woven plies strongly meets the expectations in terms of energydissipation, but that is not the case in dynamic loading. In this case, a 90° stratification seemsmore adequate. Incidentally, an inner constrained containment is more effective in most cases,reducing the initial peak load without drastically reducing the SEA value.

I detta examensarbete studeras kommande energikrav för byggnader i Sverige och i synnerhet kraven på specifik energianvändning. Detta mot bakgrund av EU-kommissionens och EU-parlamentets direktiv, EPBD2, om nära nollenergibyggnader 2020. Därefter bearbetas ett förslag på en ny ytterväggskonstruktion som med lägre U-värde än den befintliga ytterväggen ska sänka Fiskarhedenvillans olika hustypers specifika energianvändning. Syftet med sänkningen är att möjliggöra för Fiskarhedenvillan att uppfylla de kommande energikraven. Det är många parametrar som måste uppfyllas och det nya ytterväggsförslaget analyseras förutom ur energisynpunkt även med hänsyn till statik, fukt och kostnad. Beräkningar för statik och specifik energianvändning har gjorts för ett referenshus. Resultatet av att byta ut den befintliga ytterväggskonstruktionen mot det framarbetade förslaget med ca 33 % lägre U-värde gav endast en sänkning med ca 6 % av den specifika energianvändningen. För att sänka referenshusets specifika energianvändning ytterligare bör även resterande delar av klimatskalet förbättras samt ett annat uppvärmningssätt väljas. Avslutningsvis diskuteras resultatet och vi lämnar rekommendationer för fortsatta studier. / This thesis studies future energy requirements for buildings in Sweden and in particular the requirements for specific energy use. This is in light of the European Commission and European Parliament Directive, EPBD2, on nearly-zero energy buildings 2020. A proposal for a new exterior wall construction in Fiskarhedenvillan houses with lower U-value than the existing exterior wall is analyzed. The purpose of the new wall is to reduce the specific energy use to enable Fiskarhedenvillan to meet the future energy requirements. There are many parameters that must be considered. The proposed new exterior wall construction is analyzed not only from the energy point of view but also with regard to statics, moisture and cost. Calculations for the statics and the specific energy use have been made for a reference building. The changed design of the exterior wall resulted in a reduction of the U-value with 33 % but only 6 % of the specific energy use. A further reduction of the specific energy use for the reference house requires improved design of the remaining building envelope and a new heating method. Furthermore the results are discussed and recommendations for further studies are given,