This masters thesis deals with smoke spread via ventilation systems. One aim of the thesis is to investigate and explain the differences in efforts to prevent smoke spread via ventilation systems in different countries. A second aim of this thesis is to investigate how frequently occurring smoke spread via ventilation systems in Swedish buildings are. A third aim is to investigate how uncertainties in input variables to smoke spread Calculations will affect the result of calculation. To be able to do this the most important input variables are identified and analysed.

The basis of the study lies with a newly patented gearbox by cardiologist and inventor Stig Lundbäck. Stig founded CorPower Ocean AB to further develop the gearbox to be used in a wave energy device. The purpose of this project is to develop a concept of a lifting system with CorPower Oceans gearbox that is more energy efficient than a hydraulic lifting system. The goal is to use technology from CorPower Oceans gearbox inversely to perform heavy lifting as an alternative to hydraulics. The project is limited to applying the gearbox and gear rack on a forklift with a lifting capacity of ten tons.The main tool in this project will be the product development process Systems Engineering where only the most relevant parts will be used to develop a concept.

This study evaluates the retention of nitrogen and phosphorus in four newly constructed wetlands in the municipality of Falkenberg, Sweden. The four wetlands have been selected because they have been specifically constructed with the aim to reduce nitrogen and phosphorus in farming areas. The process of selecting the specific wetlands has been done in collaboration with the county administration in Halland. Through field studies in collaboration with the landowners where the wetlands are sited, the areas that provide the wetlands with water were determined. The size of these drainage areas were determined in a GIS computer program. The type of land use within the drainage areas was also determined.

The remotely operated underwater vehicles that the client develops have needs of different kinds of data channels. In order to minimize the need of physical cable between the control unit and a ROV, a multiplex protocol has been developed. The protocol has been designed with the aim of using the bandwidth of the transferring link as efficient as possible.The different kinds of data channels used during this thesis project is; RS232, RS485 and CAN. ROM and FIFO-memories have been used to be able to effectively manage the different data channels. All the reading and sending of these channels have been implemented in FPGA-technology, the coding is made generic so that it will be easier to add more channels to the system in the future.The multiplex protocol is a modified version of the method STDM and it is a proprietary protocol.

A substation must be properly protected against lightning and other external effects to the equipment in the station or staff, for that we use relay protection. They should also protect against internal errors which may occur as ground faults. There are different types of protection relays, but most common are overcurrent-, distance-, residual current- and differential protection.The purpose of this thesis was to deepen our knowledge of relay protection and to use the theoretical knowledge we got from the university studies in the work process. In the process we discovered which parameters were the most essential and calculated these for all relay protections on the substation. We also carry out a comparison between two brands of relay protection, ABB and Alstom.During our work we will test and simulate the over-current relays in a program called NEPLAN, the program will also calculate the fault currents.

Purpose: The study examines the risk a rising from the acquisition of shares, and its relation to the expected return. We would like to see how a high-risk portfolio is related to a low-risk portfolio. Although studying the portfolios annual performance.Theory: The theories that have been used in the study are, Capital asset pricing model, CAPM and portfolio theory.Method: The study is based on a quantitative method, the time interval is from 2008 to 2010.The annual reports, historical stock prices for companies and the index are used to perform Calculations based on the essay theories.Conclusion: The beta value has positive liner correlation with the expected return. When there are bad times in the world, the companies are negatively affected regardless of industry. The Portfolios developed in the same direction during the time period..

Sewer trenches usually contain material with a higher hydraulic conductivity then the adjacent soil. Thus they can serve as paths of preferential flow in a polluted area. Wastewater from factories can also leak from wastewater pipes and pollute the soil in the sewer trenches.The purpose of this project was to investigate pollutions in sewer trenches and in sewer pipes in the industrial area of Köpmanholmen, 20 km south of Örnsköldsvik in the north of Sweden. To make an estimation concerning the potential of transport of pollutions in sewer trenches, hydrological Calculations were performed.Leakage to any greater extent did not seem to be a problem in the area. This is the case both for the concrete and the wooden pipes that have served as factory wastewater pipes.

Man?s impact on the environment is something that increasingly becomes topical in today?s society. Because of this, several companies have started to take interest in the effects they?re responsible for, not least considering their image. Emissions of carbon dioxide generated from goods traffic are accountable for a large part of the total emissions of greenhouse gases in the world.

Purpose: The study examines the risk a rising from the acquisition of shares, and its relation to the expected return. We would like to see how a high-risk portfolio is related to a low-risk portfolio. Although studying the portfolios annual performance.Theory: The theories that have been used in the study are, Capital asset pricing model, CAPM and portfolio theory.Method: The study is based on a quantitative method, the time interval is from 2008 to 2010.The annual reports, historical stock prices for companies and the index are used to perform Calculations based on the essay theories.Conclusion: The beta value has positive liner correlation with the expected return. When there are bad times in the world, the companies are negatively affected regardless of industry. The Portfolios developed in the same direction during the time period..

Jämtkraft AB has recently modernized its hydropower station at Hissmofors by replacing four older worn out units with two new units. The generators uses a concept with sliding stator feet to deal with the thermal movements that occur in the stator during operation when the unit is operating intermittently. At other sites, this method revealed shortcomings in the reliability. This has made Jämtkraft AB feel uncertainty about its function and therefore want to investigate it during an early stage. The generators have a built-in monitoring system for the sliding stator feet and by using data from there the function of the sliding stator feet has been investigated. The study focused on how the different stator feet move relative to each other and how the eccentricity and deviation from roundness changed during operation. The results show that there are several indications that the function of the sliding stator feet is not satisfactory.

This thesis calculates and compares the values of improved environmental quality due to future possible investment alternatives in biogas production facilities at Käppalaförbundets Reningsverk (Käppala Sewage Treatment Works) in an attempt to determine which alternative yields the highest such value. Käppala faces three investment alternatives for the usage of biogas. The alternatives are production of vehicle fuel, district heating and thirdly, heat and power production. Estimates of the value of environmental change are calculated for each of the three investment alternatives, and these estimates are then compared. The environmental change in question is the change in discharge levels of carbon dioxide (CO2), nitrogen oxides (NOx), sulphur dioxide (SO2) and particle matter.

My questions at issue for this report has it´s beginning in the growing problems of thenegative effects of burning fossile fuels and the rapidly growing energyprices.1. Is it possible to design a micro scale powerplant?2. Is it economically interesting for a potential customer to by such a product?The aim with this report is therefor, with the help of design work and Calculations, to answerthese questions and to create a platform for building a fully functional micro scale powerplant.The material used in the report is mostly product catalogs from various industries but alsostudy course littrature about steam engines.The result of the report is that it is fully possible to design a fully functional micro scalepower plant.

This study evaluates the retention of nitrogen and phosphorus in four newly constructed wetlands in the municipality of Falkenberg, Sweden. The four wetlands have been selected because they have been specifically constructed with the aim to reduce nitrogen and phosphorus in farming areas. The process of selecting the specific wetlands has been done in collaboration with the county administration in Halland. Through field studies in collaboration with the landowners where the wetlands are sited, the areas that provide the wetlands with water were determined. The size of these drainage areas were determined in a GIS computer program. The type of land use within the drainage areas was also determined.

Nanofiltration is a proper way of preparation of drinking water. The process has a lot in common with reverse osmosis where a semipermeable membrane is used to separate a pure water flow from the remaining water. A pilot plant was used to ensure that nanofiltration is a suitable technology for a specific waterworks station in Glemmingebro, Ystad. The purpose was also to find out if a pH-adjustment is needed for feed water in a possible full scale plant.  In this case nanofiltration is used mainly to remove sulphate and calcium since the raw water contains concentrations of these substances which exceed the limits for potable water. It is important to receive a high recovery (RC), otherwise the deliviery of water won?t be high enough.

The purpose of this report is to compile and examine the cost of renovation of moisture-damaged bathrooms, to derive a target price. The target price can then be used by insurance companies to estimate the ultimate cost of future bathroom renovations.       The method is based on the compilation and comparison of the cost of repairs of previous water damage in bathrooms. The Calculations compiled based on repair estimates for different insurance losses from one of the leading insurance companies in Sweden.       The result shows the average price per square meter of floor area for different sizes of bathrooms. The average price is the basis for the estimate of future renovation costs of bathrooms. The results further show that the bathroom finishes, area and the distance between the entrepreneur and the location of the renovation have great impact on the final repairing cost.