The world?s growing need for energy together with a desire to ward off the worst consequences of global climate change has resulted in a never seen desire to invest resources in renewable energy sources. Biogas production through anaerobic digestion is one of those growing energy sources. In Sweden there are over two hundred plants that uses this biological process to break down organic substances while producing carbon dioxide and the energy-rich gas methane.This master?s thesis has focused on development of the mixture of different organic substances that is treated at a specific plant, namely Mosserud biogas plant.

A clean and affordable energy source for cooking is deficient in developing countries. People rely on fuels that contribute to environmental, social and health problems.Biogas is an alternative energy source and an increased investment in small-scale biogas production can in several developing countries be found. Several projects have started to use the technology in developing countries because of the benefits with biogas. Some cases in the establishment of biogas plants have succeeded and some have not. The study is a literature review supplemented by two field studies.

In the coming years, organic food waste will be collected in the region of Gästrikland, Sweden. The collection is planned to cover the entire region by the end of year 2007. To start with, smaller amounts are being collected and transported to a central composting plant in Sala. However, a central composting plant in the region of Gästrikland is projected.The objective of this thesis is to evaluate a number of possible methods for composting of organic food wastes regarding their environmental impacts and localization.There are four scenarios for future composting of organic waste that have been evaluated. There are two that consist of membrane composting, either in Sala or in the region of Gästrikland.

A clean and affordable energy source for cooking is deficient in developing countries. People rely on fuels that contribute to environmental, social and health problems.Biogas is an alternative energy source and an increased investment in small-scale biogas production can in several developing countries be found. Several projects have started to use the technology in developing countries because of the benefits with biogas. Some cases in the establishment of biogas plants have succeeded and some have not. The study is a literature review supplemented by two field studies.

We have investigated the visual representation of men and women in Aftonbladet?s weight site. We have made a calculation of how many of the women and the men who were portrayed smiling/ not smiling, active/passive, looking into the camera/looking away from the camera and from which camera angle the picture is taken. We also kept statistic on the gender representation of the authors of the articles.Our investigation shows that Aftonbladet?s weight site has a distinct overrepresentation of women on their pictures, but also in terms of the authors of the articles.

A clean and affordable energy source for cooking is deficient in developing countries. People rely on fuels that contribute to environmental, social and health problems.Biogas is an alternative energy source and an increased investment in small-scale biogas production can in several developing countries be found. Several projects have started to use the technology in developing countries because of the benefits with biogas. Some cases in the establishment of biogas plants have succeeded and some have not. The study is a literature review supplemented by two field studies.

The fallout from the Chernobyl nuclear accident resulted in large deposits of caesium, iodineand strontium as well as noble gases in various parts of Sweden. 137Cs has a radioactive halflifeof about 30 years and is therefore one of few radio-fission products remaining inmeasurable quantities in the Swedish soil. Radiocaesium behaves similarly to potassium insoil-plant systems and is easily absorbed by plants. It is important to understand how 137Csbehaves in different ecosystems in order to minimize the risk toward humans.The aim of this study was to determine how potassium fertilization influences radiocaesiumcontent in different forest plants and fungi. Potassium fertilizer was spread once in 1992 withapproximately 200 kg KCl per ha.

Former studies have shown that a considerable part of industries? energy usage can stem from idle times in the production. This thesis, carried out at Siemens Industry sector, evaluates the potential for using the control system to automatically put machines into energy saving mode during idle times. The main part of the thesis consists of a case study performed on machine tools at a Scania production site in Södertälje. Through load measurements the potential for energy savings was determined.The results show that there is a great potential for energy savings during idle times at the site.

Some people do not have the opportunity to visit a physical exhibition because of limited time or long travelling distances, it is here the need for a web-based exhibition arises.This dissertation describes the development of an interactive web-site representing a part of a physical exhibition of over 200 interviews on different peoples immigration to inner Scandinavia. The interviews contain text, audio clip, pictures and video clip.The website contains modern programming technologies such as HTML5, ASP.NET MVC3, SQL, JavaScript and jQuery.A cover of the technologies used and how the project has been designed and implemented is explained in the dissertation. In the end of the dissertation we discuss about how the result of the project follows the goals we set up in the start phase. The result of this project is an interactive and easy to use web-site showing a part of the physical exhibition online. An easy administration to insert new information and edit existing without any major computer knowledge..

During pulp and papermaking process a huge amount of water is used. The wastewater contains a large amount of pollutants and has to be treated before it reaches the recipient. In March 2004 a new bleaching plant was started up at SCA Graphic Sundsvall AB, Ortviken?s paper mill using peroxide. The production of bleached thermo mechanical pulp and thus the load to the wastewater plant increased.

This master thesis reviews advances in detection and diagnosis of static friction (stiction) in control valves. Control valves suffering from stiction results in oscillating control loops which in turn decreases both the process stability and reliability. Perstorp AB sees a necessity to automatically detect stiction in valves before the effects of the malfunctioning valves have become too severe. This thesis presents an introduction to maintenance, control loops and how stiction in valves can affect performance of control loops.A selection of methods presented in the literature are introduced and examined using normal operating data from the site in Perstorp. Common for all selected methods is their intuitive ideas and that they are based on normal operating data and minimum amount of process knowledge.

A clean and affordable energy source for cooking is deficient in developing countries. People rely on fuels that contribute to environmental, social and health problems.Biogas is an alternative energy source and an increased investment in small-scale biogas production can in several developing countries be found. Several projects have started to use the technology in developing countries because of the benefits with biogas. Some cases in the establishment of biogas plants have succeeded and some have not. The study is a literature review supplemented by two field studies.

Idre Fjäll currently has not full control of how visitors experience their site or if it has good usability. I have helped the company to do a usability test on their website to see how and where any improvements can be made on the page before the winter season 2010. I have also done a survey to investigate how users perceive Idre Fjälls website. Ten people of various ages participated in the survey. All test subjects was recorded with both audio and screen activity during the tests.

Biogas is a renewable fuel that can be extracted from anaerobic digestion of many differentsubstrates, for example biological household waste. An alternative handling of the waste is tomix it with other wastes and incinerate it in a combined heat and power (CHP) plant. Thisstudy uses life cycle assessment to investigate which type of waste handling that is betterfrom an environmental point of view, anaerobic digestion with biogas production orincineration. The results are based on a case study of a biogas production plant owned by thecompany Ragn-Sells in Vänersborg. The alternative is incineration at a CHP plant inGothenburg.

The construction industry has not undergone the same logistical development as the manufacturing industry; this, in combination with increased material price, leads to the fact that the construction industry must be improved. This master thesis is a part of the research cooperation Brains & Bricks goal of reducing production costs for the construction sector by 25 percent. Brains & Bricks is a cooperation between Linköping University, Peab and Katrineholms municipality. The master thesis aims to identify improvements in the flow of material, the Supply chain operation reference, SCOR, model has been used and the work has been carried out on one of Peab?s construction sites. At present the business is characterized by bad communication both between the construction site and the office as well as between the construction site and suppliers.