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4800 Uppsatser om High temperature - Sida 26 av 320
Småskalig vattenkraft vid Olofsfors bruksmuseum : Med faunapassage
In Sweden there are 1894 small-scale hydropower plants in operation, which together generate 4.3 TWh of electricity per year according to Swedish hydropower compound (SVKF, 2011). This corresponds to the annual consumption of about 860,000 Swedish households (based on an annual consumption of 5000 kWh). In the mid-1950s there were around 4000 small-scale hydropower plants in operation in Sweden before cheap fossil fuels and uranium competed with them, in the current situation only 1,894 of these are in use. If slumbering small hydropower plants once again would be taken into use and some new ones are built, we would be able to extract about 7 TWh of renewable electricity from these annually in Sweden, representing about 1.4 million households.The thesis intends to calculate and construct a hydroelectric power plant at the existing dam in Olofsfors and give suggestions on how the power station should run during the time that fish migration is greatest in Leduån.The turbine and generator to the station in Leduån at Olofsfors is designed by the height of the fall and the water flow through the dam. The turbine selected for the station is a CK-1000RM turbine with a 4-pole 250 kW generator from Cargo & power turbine Sweden AB, which is expected to deliver 1.2 GWh per year.
Faktorer som påverkar sockerförlusten vid lagring av sockerbetor : inverkan av lagringstemperatur, lagringstid och vattentillgång
This thesis is a part of the project "Sustainable harvesting and storage of sugar beets, more sugar to practice". The work has included a large part of practical experimental work with weight measurement, graduation and storage planning. The aim of the project is to be able to see whether the cultivars react differently in different storage conditions. The project has included storage under controlled conditions to give as accurate results as possible. To be able to mimic the farmers own preconditions the samples was harvested with a conventional Holmer.This project has two parts, one concerning the nature, time and temperature on storage where a number of different cultivars where investigated during three different recording times, two different temperatures and controlled in a controlled environment.
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.
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.
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.