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1483 Uppsatser om Water vapour transmission - Sida 4 av 99

Utveckling av kyl- och smörjsystem för ekobilen Agilis HCCI motor

Every year, KTH participates in the Shell Eco Marathon, a competition whose goal is to design a vehicle that can go as far as possible using only the equivalent energy of one liter of petrol fuel. This year, one of KTH?s contributions to this race is the Agilis prototype; a car powered by a uniquely configured HCCI-engine developed at the university. The engine is dependent of several subsystems in order to work properly, among other, systems for cooling and lubrication.Combustion engines are in need of a cooling system that reduces the heat developed during the combustion. In general, two main types of cooling systems are employed; either air cooling, where the outside of the cylinder is exposed to a flow of the surrounding air, ore water cooling, where water flows in tubes around the engine, and the heat are transferred by the water to the surrounding air through a heat exchanger.The purpose of the lubrication system is to prevent the friction that builds up in the interference between moving parts in the engine.

Modelering av Wideband : Code Division Multiple Access

Today wireless transmission of data is becoming more and more popular and the need for faster transmission rates is increasing. Since the bandwidth is limited it is important to try to use it to the fullest. CDMA is a technology that allows multiple accesses on the same frequency and time thus making it very bandwidth efficient. The CDMA technology was first introduced in the second generation?s cellular systems but has since then been improved and is reused in today?s 3G systems as Wideband CDMA.

Effect of vortex-processed water on tomato (Solanum lycopersicum) plants

This pilot study examined whether treatment with Vortex Process Technology (VPT) of the irrigation water used on tomato (Solanum lycopersicum) plants had any effect on plant growth. In a block experiment, with two blocks comprising 12 vases containing 1 L water and two tomato plantlets, treatment in which, nutrient solution was based on Vortex-treated water was compared with an control using untreated water. All vases were kept in a static aerated culture system in a daylight chamber for four weeks. The results showed that the effect of the two blocks exceeded the effect of vortex treatment in terms of leaf area and weight of fresh and dry matter. Plant height, stem width and internodal length were significantly different in tomato plants grown in Vortex-processed water compared with the untreated control.

Analys av off-design prestanda för ett absorptionskylsystem

This master thesis project at KTH is performed in the Mechanical and Aerospace Engineeringdepartment at University of Florida (UF). The thesis is a small part of a gas turbine researchproject where a vapour absorption refrigeration system (VARS) and a high pressure regenerativeturbine engine (HPRTE) are integrated together. The main objective is to build a computermodel of the VARS. The computer model is supposed to be used to analyse the off-designperformance of the VARS and should also be easy to integrate as a subroutine in a more complexsystem model. To model the VARS some knowledge of the absorbent/refrigerant mixture had tobe well known, in this case a mixture of ammonia and water.

Vattenanläggningar som gestaltningselement i offentliga miljöer :

Water constructions - as a design element in public spaces is the title of this Master thesis, with a focus on waters function and meaning in the urban environment. By way of introduction, mans relationship to places is described and the factors that contribute to the reality that we prefer some places more than others. A good place to stay is open but well defined, gives protection, offers a good view and is varying in topography and vegetation, together with contents of single landscape elements like visible water. This study then continues to discuss mans relationship to water and its means for our wellbeing. Despite the fact that people have a different relations to water due to personality, background and age, it?s an element that raises positive feelings, interest and aesthetic pleasure for most people.

Hot och risker med dricksvattenförsörjning : Förutsättningari tid och rum för bevarande av Sundsvalls och Timrås dricksvattenförsörjning

This study describes what impact activity within Wifstas, Matfors,Grönstas and Nolbys water protection areas have on the quality of the drinkingwater. It considers the use of the area, environmentally dangerous activitiesin the past and present, the geology?s part, what harm hydroelectric power damsmay cause if they break and how climate change might affect the area in thefuture. It also takes into consideration activities outside the waterprotection areas which might have a suspected impact on the water quality. Theresults of the study are that pollution from infrastructure such as roads, orwastewater from treatment plants may cause occasional contamination of thedrinking water, foremost due to flooding.

International transmission of stock market movements - a Scandinavian focus -

Previous research has found an increased transmission of stock movements in Europe, partly caused by the establishment of institutions as the EU and the EMU. The purpose of this paper is to find the possible impact from the EU and the EMU concerning the evolution of international transmission of stock market movements, on four Scandinavian markets, Denmark, Finland, Norway and Sweden. The research is based on primary data, existing theories and earlier studies regarding international transmission of stock market movements. The examined method is a VAR (Vector autoregressive model) including a 10x1 vector of variables. Furthermore the tests considered are correlation, granger-causality, variance decomposition and impulse response.

Modellstudie av föroreningsretention i Bäckaslövs våtmark : Tillämpning av modellverktygen MIKE SHE WET och MIKE 21

During the nineties, ecological handling of urban storm water became very popular in Sweden. Together with Chalmers University of Technology and two Swedish communities, DHI Water and Environment has been doing research of storm water ponds and constructed wetlands. This thesis work is a part of that research project. The work has been applied at the Bäckaslöv storm water treatment plant in Växjö, Sweden. The plant consists of one storm water pond and a downstream constructed wetland.

INOMHUSMILJÖ I SMÅHUSMED FTX-VENTILATION : EN LITTERATURSTUDIE MED ENKÄTUNDERSÖKNINGAR OCHMÄTNINGAR

This master thesis was initiated with the aim to answer at what level of installed capacity of wind power in the northern parts of Sweden it would be beneficial to improve the transmission capacity from the northern Sweden. During the process of this work the aim has changed to try and create a model that can be used to analyze how well the hydro power installed in the northern Sweden can even out the quick changes in wind power production.To create a good model of all hydro power in northern Sweden is a very large job, unfortunately too large for a master thesis. This report therefore ends with an extensive analysis of the simplifications that have been made and their effects as well as a list of the future work that has to be done.The model that has been created have shown to be effective and produce good results. The conclusions that can be made is that the northern Swedish hydro power have very good possibilities to balance the wind power production. Only a few cases where water have been spilled even though there has been some free capacity has been discovered.

Vilken preferens har tjockskalig målarmussla (Unio crassus) för bottensubstrat och vattenhastighet i Storån, Östergötland?

The thick shelled river mussel (Unio crassus) has a fragmented distribution in southern Sweden. It is a threatened and protected species. In both the Swedish red list and the IUCN Red List of Threatened Species Unio crassus is classified as Endangered (EN). Causes for this classification are for instance differentiated bottom substrate and deterioration in water quality. In this study, habitat preferences of Unio crassus were investigated to assist in future restoration work.

Hållbar vattenförsörjning i områden med vattenbrist : Sustainable water supply solutions for areas affected by water shortage

In some coastal areas in Sweden water shortage sometimes appears because the withdrawal of groundwater is greater than the groundwater recharge. It creates a situation where the available groundwater is insufficient to support residents and businesses with drinking water. The high withdrawal of groundwater also creates a risk for saltwater intrusion to drinking water wells. The problem most commonly occurs during the summer when the groundwater recharge is low, but the population is high, due to tourism and summer residents.The purpose of this study was to investigate how local water supply in areas affected by water shortage can be solved as sustainable as possible. The work was divided into three parts where the first part comprised of a literature review on water systems in which four different options were investigated: artificial groundwater recharge, rainwater harvesting, desalination and water reuse.

EU:s medborgarinitiativ : En framkomlig väg för att minska det demokratisk underskottet?

The European Union is struggling to maintain democracy and tries to increase the participation among the citizens in Europe. The European Citizens? Initiative, ECI, is a platform established by the European Commission to allow citizens to propose new legislation. ?Water and sanitation are a human right! Water is a public good, not a commodity!? is the first ECI that has met the requirements.

Små vatten- och avloppssystem : Möjligheter till inskränkning av verksamhtesområden

This study is focused on small scale water and wastewater handling in Sweden. The study is divided into two major parts; the first describes common methods for water- and wastewater handling and the second part is a case study on three small and expensive systems in Gällivare municipality, in the north of Sweden. In the case study, abilitys for the local government to hand over unwanted systems to the water users is investigated and found to be a plausible solution to cut costs for two out of the three studied systems. In the third case, water and wastewater systems is not recommended to be handed over but other ways of cutting costs are suggested..

Brunnsviken : Utvärdering av åtgärder för förbättrad vattenkvalitet

Periods of hypoxia are a recurring issue in Brunnsviken. Main factors that trigger hypoxia in Brunnsviken are eutrophication  due to anthropogenic emission of nutrients, stratification in the water column due to salinity and temperature differences  that prevents mixing and a sill inlet that prevents water exchange. As an attempt to improve the oxygen levels, bottom water is pumped from Brunnsviken causing aerated surface water to flow back into the basin.  The objective of this Master?s thesis was to study the change in dissolved oxygen levels due to pumping.

Inventering av processvattenbalans : fastställande av fjärrvärmedistributionens läckage inom Vattenfall Värme Uppsala AB

Heat is distributed to the district heating customers through pipes with water as a heat carrier. The district heating system is complex. To decide what is leakages from the district heating net versus what is the water consumption of the plant, is difficult. Therefore, the purpose of this master thesis is to establish a model where the district heating net?s leakages but also the water consumption of the plant can be followed daily. The project is performed at Vattenfall´s district heating power plant in Uppsala. Information is gathered through discussions, drawings of the plant and guided tours of the plant.

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