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4952 Uppsatser om High temperature electronics - Sida 32 av 331

OTEC för Tarawa

Ocean Thermal Energy Conversion, OTEC, a technology using the temperature difference between cold deep seawater and warm surface water, can extract the work in the form of electricity. OTEC gives also synergies of drinkable fresh water. The temperature difference has an impact on the efficiency of the technology, which means that the feasibility of OTEC is geographically limited. The project intends to explore the possibility of replacing the atoll Tarawa?s present electricity generation with an OTEC plant and to explore synergies. In the present situation all of Tarawa?s electricity is generated by fossil fuels.

Ungdomars samtal om sexualitet : En narrativ studie om ungdomars samtal med gymnasiekuratorn

Adolescents are coming to high school counselors to talk about sexuality for various reasons and the purpose of this study is to gain an enhanced understanding of how adolescents in high school talk regarding sexuality and LGBTQ. The empirical material is assembled on eight narrative interviews with high school counselors. The school counselors have through their experiences in meeting adolescents, submitted stories about the adolescents´ conversations regarding sexuality to us. The empirical data were analyzed by a standard critical perspective and with the help of heteronormativity it made norms about what is normal and abnormal visible and problematized. The result demonstrates that adolescents are influenced by norms of society, the media, family and friends.

Drainfill

Ocean Thermal Energy Conversion, OTEC, a technology using the temperature difference between cold deep seawater and warm surface water, can extract the work in the form of electricity. OTEC gives also synergies of drinkable fresh water. The temperature difference has an impact on the efficiency of the technology, which means that the feasibility of OTEC is geographically limited. The project intends to explore the possibility of replacing the atoll Tarawa?s present electricity generation with an OTEC plant and to explore synergies. In the present situation all of Tarawa?s electricity is generated by fossil fuels.

Avel för hållbarhet och livslängd hos köttdjur

The purpose of this literature study was to investigate the possibilities to improve longevity and stayability of beef cattle with breeding. The breeding goal for beef breeds is to produce animals with high capacity for growth and good feed efficiency. Longevity and sustainability are two important features to include in the breeding goal. If longevity is increased each cow can produce more calves and the number of female calves used for recruitment can be reduced and only the best heifers need to be selected for breeding. The benefits of longer life is that it lowers the costs of recruitment animals, it increases the number of young animals that become available for slaughter, and it increases the proportion of high producing animals in the herds.


Anaerob psykrofil behandling av hushållsavloppsvatten i UASB : Utvärdering av kapaciteten hos en två-stegs UASB-reaktor för behandling av hushållsavloppsvatten

Hammarby Sjöstad is a new district in southern Stockholm. A main objective with the Sjöstad project was to halve the environmental impact compared to other construction work. The environmental goals involve a halved water consumption rate, a local treatment of storm water and trials aiming to extract nutrients from the waste water. Sjöstadsverket is an experimental treatment plant used for testing new treatment processes for domestic waste water from Hammarby Sjöstad. The results are to be compared with the conventional process used at Henrikdals treatment plant today.

Kognitiv auktoritet och Wikipedia ? En analys av gymnasieelevers källkritiska granskning av Wikipedia

The main purpose of this master?s thesis is to examine how high school students evaluate the quality of the information available on the online encyclopedia Wikipedia. By doing quantitative research based on questionnaires we expected to find that the means for judging that students use in this situation are most frequently based on a text?s intrinsic qualities in the point of view of its content. It was also our presupposition that 18 and 19 year old high school graduates have received some education in information research and authoritative sources on the Internet.

Småskalig säsongslagring av solenergi för uppvärmning av bostäder : Simulering av lagerutformning och konsekvensen av adderade uppvärmningsbehov motsvarande en pool och ett atrium

The sun is a huge energy source with great potential of providing energy to the heating of homes and other buildings in an environmentally sustainable manner. In order to provide buildings with energy from the sun it is necessary to transfer the energy supply over time to when the demand arises. By storing the heat in a seasonal storage, solar energy from the summer can be used in the winter when the demand for heating is greatest.Today's existing plants are mainly in Europe and particularly in Germany. These facilities are designed to supply heat demands greater than 400 MWh and covers about 40-50 % of this need which consists of energy for space heating and domestic hot water. How much of the heat demand that is covered, the solar fraction, is partly due to losses from the storage which in turn is connected to the surface area of the storage.

Sexualvanor och preventivmedelsanvändning hos svenska gymnasieelever

The aim of this study was to examine sexual behavior, contraceptive use, self-rated health, lifestyle factors and the prevalence of HPV vaccination among last year high school students. The study was a quantitative cross-sectional study which was a substudy of the longitudinal study " Pornography, Youth and Health". Results showed that the majority of students had had sexual intercourse (75 %, n=524) and both performed (67 %, n=479) and received oralsex (70 %, n=498). Forty percent (n=282) of the students had had one night stand, a quarter (n=159) anal sex and 29 (n=202) percent sex with a friend. The contraceptive use increased from the first to the last intercourse while the use of condoms decreased.

Design and implementation of a 5GHz radio front-end module

The overall goal of this diploma work is to produce a design of a 5 GHz radio frontend using Agilent Advanced Design System (ADS) and then build a working prototype. Using this prototype to determine if RF circuits at 5 GHz can be successfully produced using distributed components on a laminate substrate. The design process for the radio front-end consists of two stages. In the first stage the distributed components are designed and simulated, and in the second stage all components are merged into a PCB. This PCB is then manufactured and assembled.

Hur står sig Modigliani och Millers teori om kapitalstruktur under hög- kontra lågkonjunkturer? : en studie av 30 börsnoterade bolag på den svenska marknaden

Problem formulation: This paper will examine how the capital structure of firms affects their market valuation by applying the Modigliani-Miller theory on Swedish listed companies in a boom and a recession. The study will examine whether it is possible to draw any conclusions as to whether companies with high debt to equity ratios are valued lower in a recession, in comparison to companies with low debt to equity ratios.Purpose: To empirically test the Modigliani-Miller theory of capital structure in a boom and a recession in order to see if the companies? market value is affected differently depending on whether they have a high or a low debt to equity ratios.Methodology: The essay has a deductive and a quantitative methodological approach. Data analysis was done through a correlation analysis, a regression analysis and a hypothesis testing.Theory: The Modigliani-Miller theory of capital structure with taxes states that companies with a high debt to equity ratios has a higher value. One of the risks with a high level of debt could be that during a financial downturn companies have more difficulty realizing capital and are thus more likely to go bankrupt.Conclusions: The study shows results that are contrary to the Modigliani-Miller's theory; all the correlation analyses between debt to equity ratios and market value are negative.

Geografisk prioritering av CTI-utrustad virkestransportkapacitet

Previous studies of central tire inflation (CTI) in truck transport of roundwood have shown potential benefits to include more even wood flow and reduced road damage. The greatest benefits are found to be during periods of low bearing capacity such as spring thaw. No previous studies have examined geographical variations in the potential benefit of CTI-equipped trucks. The aim of the study was to develop and use a simple method for geographically prioritizing the use of CTI-equipped trucks within a forest company´s sector of activity.The host company for the study was Holmen Skog. The area studied consisted of Holmen Skog?s entire sector of activity extending from the province of Västerbotten to the province of Småland.

Analys och förbättring av en mätenhet för laddning av elfordon

Reducing the CO2-pollution, resulting from the combustion of fossil coal for energyproduction, is important to affect environmental changes. One way to achieve a reductionis to use the oxy-fuel technology. The technology uses O2 and re-circulated flue gasduring the combustion which results in a flue gas mainly consisting of CO2. The flue gascould then be compressed and stored without environmental effects. A problem thatfollows from the compression is the risk of acidification in sensitive parts of the process.Acidification can occur because of reactions following from the contact of condensedwater and sulphur- and nitrogen-oxides which are also present in the flue gas.This report compiles and evaluates the basis of a scientific unit with the purpose ofexploring the possibilities of extracting impurities of SOx and NOx from the flue gases.The dimensions of the unit are based on basic conditions, defined for an existing oxy-fuelprocess at Chalmers, and on the results of computer modelling.

Modellering av ett OFDM system för IEEE 802.11a med hjälp av Xilinx blockset

Kraven på dagens trådlösa förbindelser kommer hela tiden att öka och med detta följer även högre krav på nya produkter som kan tillgodose de ökade kraven. För att göra processen från idé till produkt snabbare krävs enkla verktyg för att snabbt kunna gå från den formulerade standarden till en hårdvaruprototyp. Detta arbete har använt sig av ett av dessa verktyg som idag finns tillgängliga, Xilinx System Generator for DSP 1.1, för att ta fram sändare och mottagare för en del av den trådlösa standarden IEEE 802.11a. Arbetet ger en beskrivning av hur sändare och mottagare är uppbyggda samt även synpunkter på System Generator och beskrivningar av problem som uppstod under arbetet.

Faktorer som påverkar lönsamheten vid köp av skogsfastigheter i Norrbotten

During the past 20 years, the price of forest estates in Sweden has raised more than the price of timber. The purpose of this study is to investigate if it, despite this development, is possible to buy a forest estate based on economic grounds. Different forest parameters will also be studied to analyse their effect on the profitability. The study is done in cooperation with the company LRF Konsult. Purchase price of 34 forest estates near the coast of Norrbotten, Sweden, has been compared to yield valuation. For the valuation, guidelines from the Swedish author Lantmäteriet was used.

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