Umeå Energi are working towards a goal, that in the year of 2018, they will be completely climate neutral. As a part of this, one target is to reduce their grid losses by 4 % of the 2012 level, which corresponds to an overall reduction of the grid losses of just over 1.7 GWh. In many residential areas, the distribution grid is designed and rated for electric heating as the heating in the houses. As many of the houses later has been converted to other types of heating, their electricity use has decreased and the total power output from many of the secondary substations has decreased significantly. Because of this, many of these stations today are well oversized, which in turn means that the energy losses in these stations are unnecessarily high.In this degree project, 25 secondary substations have been studied, all located in residential areas in and around central Umeå.

In the last few years people have become more and more aware of how humanity is affecting the climate. In the direction of reducing the greenhouse gases is to design engines with higher tensile properties and reduced weight, in order to achieve lower fuel consumption and cleaner fuel incineration in today's truck engines.In order to achieve these requirements it?s necessary to increase the combustion pressure in the engine. This requires higher tensile properties and high thermal conductivity of the engine material. The department of Component Technology at the University of Jönköping in collaboration with Volvo Powertrain AB, Scania CV AB and DAROS Piston Rings AB has been commissioned to develop this material and to find knowledge of material properties used in truck engines and piston rings used for marine applications.The purpose with this work is to analyze the tensile properties of a series of cast iron, cast under different metallurgical conditions.Four different series of cast irons have been analyzed from four points of view, carbon concentration, nodularity, amount inoculation and cooling rate.After the tensile test all specimen data was analyzed in a mathematic calculation program called Matlab 2006a.

Food insecurity is a great problem worldwide and Ethiopia is one of the sub-saharan countries that are suffering from poverty and food insecurity and a large part of the population are living in a state of undernourishment. To reduce these problems, a successful horticulture production can be an important factor. Compared to other crops, fruit production in Ethiopia has not been a large part of the agricultural sector. However, the demand on the domestic market is increasing as well as the production for avocado and mango. To increase food security it is important to focus on ways to decrease post-harvest losses of food products and not only have the productivity of agriculture in focus.

This report is the product of the course AF101X, a bachelors degree in Samhällsbyggnad atKTH. The task of the course is to design a small house at a given location and also implement adeepening study. The house in this report is located in Kiruna in the north of Sweden, where theclimate is much colder than in the rest of the country.The deepening study of this report is to evaluates how realistic passive housing north of thePolar Circle is based on those facts. The house will to some extent be designed to fit the passivehousing standard.

The aim of this report was to do a case study at a geothermal heating system which has been in operation for about 5 years, and study if its performance has changed during this period of time. A literature study about the processes involved was also done in purpose of background knowledge.The tenant-owner?s association Duvan at Petterslundsgatan in Uppsala installed year 1999-2000 a geothermal heating system. The purpose of this installation was that they hoped it would lead to a smaller usage of district heating which would lead to a reduction of the heating expenses for their buildings. The geothermal heating system consists of 19 energy wells and 4 geothermal heat pumps, and it is one of the first systems of that size in the region of Uppsala.

The main goal with this thesis report was to come up with ideas of how to make the use of energy more effective and thus save money for the company.First a survey was made to find out where and how the energy consumers were divided within the company. The results were then used in calculations to find out how much money that could be saved and how long it would take to get back the investments.There is a big potential in saving money by recovering heat from the UV-lamps with a heat exchanger. It would also even out the pressure in the factory which is a source to heat loss and a cause for discomfort amongst the employees. It?s possible to save 105 000 kr in a year and the money needed for the investments is 600 000 kr.By using the recovery air more effectively the company could save up to 250 000 kr a year in lowered heat purchases, but this would require the use of automatic dampers.If you reschedule the running times for the wood chipper and invest in some kind of load management, for example Sydkraft?s ?Energidirigent? you can save at least 42 000 kr.

The purpose of this master thesis is to investigate different types of measures for making buildings more energy efficient and to estimate their profitability. The calculations were performed with the building simulation program VIP+ and the evaluation of the profitability with the life cycle cost method. Furthermore, it was examined how losses in the distribution of secondary systems of district heating can be avoided. Options to replace district heating with a local district heating system based on bio-energy have been investigated. The possibilities of achieving more efficient thermal energy consumption and production for the chosen estate were also examined.The object of the study has been a residential estate with 133 detached houses in Uppsala, built in 1974.

Research in solar energy is taking big steps in both solar heating and solar electricity. It´s not only the technologies alone, but also the combination of both solar electricity and solar heating which is what is called a solar hybrid. The idea of a solar hybrid is that a solar cells efficiency decrease with increased temperature and can with help from a solar collector be cooled and the heat can be utilized. This thesis report compares heat production and electricity production with respect of, in first hand, a solar hybrids geometry in the cooler. The theory chapter describes solar heating and how different solar cell technologies work and their environmental impact at the production and how compatible these technologies are for the solar hybrid.

At Forsmarks Kraftgrupp AB (FKA) forces on pipe systems due to transient flow are frequently calculated as a step to verify their structural integrity. In nuclear industries these forces are often calculated with a one dimensional thermal-hydraulic analysis-code called RELAP5. When calculations regarding more complex geometries are needed, the three dimensional code Fluent is often used. This code is highly time consuming and requires large computational power.This projects aim is to compare calculations of pressure, flow and forces carried out by RELAP5 and Fluent for an arbitrary pipe section during transient flow conditions. This has been accomplished by constructing a simple geometry for which a transient flow is simulated in both programs.

Skärgårdsstiftelsen, which is responsible for several of the archipelago islands in Stockholm, has chosen to explore the possibilities for more sustainable heating systems in buildings on the islands in collaboration with KTH. A reduction of energy use and improving the efficiency of existing heating systems are included as part of the environmental work. This report studies the island of Grinda, which is located outside the area of Vaxholm in Stockholm. The study area consists of a guesthouse consisting of a restaurant as well as conference facilities and four neighboring cottages used for overnighting. The cottages now run solely on direct electricity, both for heating and hot water.

Phosphorus is essential to all plants and is taken up from the soil as the ion H2PO4 - (and to some extent HPO42-). Plant availability depends on, among other factors, the soil pH. In order to provide for plant available phosphorus, it is applied as mineral fertilizers and farmyard manure. However, that causes phosphorus leaching from arable land to surrounding surface waters and lakes and contributes to the eutrofication. There are three types of soils in Sweden that are at higher risk of contributing to phosphorus leakage.

Students? performance in school is dependent on the indoor climate. This report studies four schools regarding air quality and thermal environment. A survey was made at the schools as well as measurements of carbon dioxide, dampness, thermal climate and, as an indicator for the furniture?s capability to collect dust, shelf factor and fleece factor.

Background to problem: Pensions play a big role in people's lives when life expectancy continues to increase. Companies can choose different ways of reporting their pension plans, and within the defined benefit pension plan poses the actuarial gains and losses that can be reported based on three different methods. Only one method will exist from 2013, how will the companies that use the other two handle the new situation?Purpose: Investigate why different companies have chosen to report its actuarial gains and losses along the corridor approach, directly against income or directly in equity. How will the companies that use the corridor method manage the situation when it will only be allowed to report in other comprehensive income as of 2013 and how will this affect them.Methodology: Data was collected through qualitative questionnaires sent to companies listed on Nasdaq OMX Nordic Stockholm, Large Cap and Mid Cap, and a qualitative interview.

This report is the written documentation of a project work carried out at the Division of Engineering Materials at Luleå University of Technology in cooperation with Seco Tools AB. The project deals with the analysis of residual stresses in Ti-Al-N thin film grown on WC/Co cutting inserts. The composition of Al varied from 0% up to 75%. Increasing the Al content in the Ti(1-x)Alx N compound improves the compressive residual stresses even after annealing of the material. The experiments have been performed in a high temperature x-ray diffractometer (HTXRD) where the interplanar atomic spacing was determined in-situ and subsequent converted into stresses.

This master thesis is an in-depth study of an existing heating system at a household cooperative in Uppsala that has been converted from district heating to a bedrock heat pump system. The study focuses on an economical system optimisation of the building?s complete heating system. The aim was to determine how well a heat pump system in large buildings actually work, find out possible ways to optimize the existing system and point out important system parameters for new heat pump installations in larger buildings.The project points out a possible energy cost reduction of 45 % without investment and further cost reductions with equipment investments. A reduction by 30 % is possible by improvements in the regulation system and 15 % is possible by maintaining the brine system.