The last hundred years humans have drastically changed the amount of available nitrogen in nature. Today human activities release twice as much available nitrogen as all natural processes are doing together. We also have degraded nature´s possibilities to take care of nitrogen through the draining of wetlands and straightening of rivers. In order to regain the potential of nitrogen retention in the water systems there now requires a reshape of the landscape we live in. A planned expansion of the mining activities in Garpenberg, Dalarna, would double the content of nitrogen in the waters below the mine.

Uppsatsen syftar till att analysera politiska aktörers agerande för att framställa sin hållning inför folkomröstningen om kärnraften 1980 som trovärdig och rationell. Studien undersöker historiska källor i form av informationstätt opinionsmaterial samt statliga utredningar och propositioner med anknytning till folkomröstningen. Undersökningen är baserad på den teoribildning inom teknik- och vetenskapssociologi som kallas science and technology studies ? STS. Det analytiska verktyg som källmaterialet analyseras utifrån är begreppet energisäkerhet.

For several years Uppsala University together with several companies has been involved in a WISENET project aimed at improving railway transport security. By placing a sensor system near the wheels of each wagon, the temperature of the bearings can be measured and transmitted to a collector placed centrally on the wagon. This in turn transmits the collected data to RFID receivers placed intermittently along the railway.As the signals are transmitted wirelessly, problems may occur as the antennas get dirty or coated with ice and snow. To determine the effects of these coatings, several tests were performed examining the reflection coefficient S11, the impedance Z11 and the efficiency eta of an antenna, and how they varied when various coatings were placed over the antenna. Examined coatings were ice, snow and water to determine the effects of weather, and various metal-based coatings: powdered iron both pure and partially oxidized, and iron ore granules.

Due to global climate change and the rising levels of greenhouse gases (GHG) in the atmosphere, the interest for seeking solutions for mitigation has increased. While much attention has been directed towards technical solutions such as carbon capture and storage (CCS), biogenic carbon sinks has also garnered significant attention. Previous studies have shown that coastal ecosystems such as seagrass meadows and mangroves have a much greater capacity for storing carbon (C) compared to terrestrial ecosystems. That raises the question if other coastal ecosystems, such as coastal wetland forests, that previously haven?t been considered as blue carbon habitats also contribute to coastal carbon sink capacity.

The purpose of this thesis work was to develop an automatic fault detection system for surveillance of bearing temperature in hydropower turbines. The parameters used except the bearing temperature were cooling water temperature and cooling water flow. A simple static model based on data sampled every minute was developed to estimate the bearing temperature. Then a detector for detection of change in bearing temperature based on the CUSUM-algorithm was designed. Since the amount of data was very small the developed model was too uncertain to be used in a working system.The designed fault detection system showed to work well for the available data.

One of ABB Power Systems´s business areas is HVDC (High Voltage Direct Current) technology. HVDC is used for transmissions for both short and long distances. One of Power Systems?s products is called HVDC Light. HVDC Light is a relatively new technology for power transmission, but have before only been used for motor drives applications.

Structural rationalizations and regionalization of the agricultural sector in Sweden has lead to unevenness in thedistribution of plant nutrients. Nutrients are lost from crop producing farms as harvest products are sold, whilefarms with animal production often have manure in excess of their needs. In addition to this the retention ofwater and nutrients in naturally occurring wetlands has decreased due to a reduction of wetlands in number andsize in the agricultural landscape. This increases nutrient levels in agricultural run-off and causes eutrophicationas well as nutrient losses from arable soils. One potential solution to both problems would be to store nutrientrichsurface water from agricultural areas and use it for irrigation of agricultural crops.

Agricultural drainage ditches are links between fields, lakes and oceans, having the potential to transport e.g. sediment and nutrients. When in a good condition, drainage ditches can act as sinks for e.g. phosphorus and sediments and prevent eutrophication downstream. The aim of this study was to determine the condition of one agricultural drainage ditch and to come up with suggestions for appropriate measures. The aim was also to determine which of the ditch?s properties that were possible to evaluate visually, which processes they represented as well as which properties required complementary physical analysis. This in order to contribute to the work of developing a method for determining the status/condition of agricultural drainage ditches.

The aim of this study was to describe and analyse the perceptions that ten 12-15 yearold pupils with special educational need, who had been assigned a personal computer, have about Information and Communication Technology (ICT) in the learning process. Data was collected by personal interviews and observations. Sociocultural perspective and phenomenographic research approach were used as theoretical and methodological frameworks in analyzing and understanding the result. The major conclusions were that most respondents perceived the computer as beneficial assistive technology for learning, but some felt singled out by having a computer to assist in learning. Students had various opportunities to succeed in using their tool depending on e.g.

Companies that are facing the global market are put in to new challenges in order to streamline its business. One industry that has realized that changes are necessary is the construction industry, it is an industry witch is far behind the development of introducing information technology-tools systems in there business. It has shown there is a relation between high IT usage and high productivity, which is one of the reasons to why companies in the construction industry should purchase a business system especially for procurement. However, companies that have purchased a business system are facing difficulties in having their employees using it for its purpose. People react differently to changes and that?s why variations in quantities exist for usage of information technology-tools.

This paper deals with the opportunities for the technique of condensation, for wood fired household heaters, on the Swedish market. In this project the condenser is preceded by a scrubber and both energy exchange and separation of unburnt particles have been studied. The facility studied is connected to a wood stove at 30 kW. The tests would show that the effect from the stove never reached above 16 kW. This might be a result of the low temperature of the water going into the stove, from the condenser. In addition to this the wood was not of highest quality and the stove could have needed some maintenance before the tests.

Föreliggande rapport är avsedd som ett examensarbete i elektroteknik (20p).Syftet med arbetet är att skapa en applikation för att finna störningar pålågspänningsnätet upp till 95kHz. Bakgrunden till arbetet kommer frånenergibolagen som vill kunna skicka datainformation direkt pålågspänningsnätet, detta vill de kunna göra med hastigheter mellan 2k ? 5kHz. Beroende på med vilken hastighet man vill skicka information kan störningar mellan givna frekvenser hindra datatransmissionen, därför är detviktigt att hitta vid vilka frekvenser störningarna uppstår så att lämpligaåtgärder kan vidtas.Grundläggande delar i applikationen är ett oscilloskop för mätning, dator medGPIB- kort för upptagning av data och LabView programvara för hantering avdata. För frekvensanalys kommer Fast Fourier Transform, FFT, att användas,varvid en grundläggande beskrivning kommer att medfölja..

This report is commissioned by the Water and Sewage Agency in The City of Mariehamn, Åland. The basic aim is to investigate positive or negative effects of a relocation of the sewage pipe from a wastewater treatment plant, Lotsbroverket. The environmental licence of Lotsbroverket is to be revised and The Environmental Appeal Board at Åland?s Government and Administrative Board has made demands that several possible locations in an outer water area should be examined. The present location of the sewage pipe is in Svibyviken, which has been classified as an ?inner water area?.The objective of this work is to study to which extent the nutrient loading from Lotsbroverket influence the environmental conditions in Svibyviken, and to investigate the suitability of different locations of the wastewater pipe from Lotsbroverket.The way a coastal area looks, i.e., its morphometry, determines to a large extent its ecological characteristics.

This thesis work has been carried out at the consultant company Pöyry Sweden AB in Norrköping, whom performs the task for E.ON heating Sweden AB, Händelöverket in Norrköping. The report shows methods to manufacture slurry consisting of fly ash and water. The slurry shall be pumped into several former oil storage rock shelters that E.ON has put into operation for the specific purpose. The ash mixture also develops hydrogen gas in contact with water.The work has aimed to produce different suggestions of methods and equipment that can be used for the objective. Mixing method and security issues were in centre while working with the suggestions.

A renewed application for environmental permit for the Hovgården landfill in Uppsala shall be submitted before December 2004, therefore the municipality of Uppsala needs improved knowledge of the contents, mostly organic compounds in the leachate and they also want to find a method to minimize the emissions of these compounds. The purpose of this study was to find a practical and economical method based on chemical oxidation using oxidants. The oxidants investigated are Fenton's reagent, hydrogen peroxide, Oxypro, potassium permanganate and potassium persulfate. The study was made on untreated leachate and leachate that has been treated in an aerated dam followed by sedimentation dams collected from the Hovgården landfill, and alson on sludge water from sludge storage cells. The effects of the five oxidants have been established by analysing the UV absorbance at the wavelengths 253,7 nm and 260,0 nm at different pH values. The UV absorbance was used to indicate the amount of aromatic hydrocarbons in the water. Also analyses of iron and manganese were done after the experiments with potassium permanganate, hydrogen peroxide and Fenton's reagent.