Biogas mainly consists of methane and carbon dioxide, where methane is theenergy-rich gas, and is naturally created when organic matter breaks down in absenceof oxygen, also known as anaerobic digestion. A biogas plant re-creates the anaerobicconditions inside a digester where the organic substrate is fed into and digests toproduce biogas. The gas is then used to produce energy by combustion and can beseen as a completely renewable fuel.Today, energy from biogas is used primarily by major stakeholders such asmunicipalities and thus the plants become very large with high investment- andconstruction costs. There are currently few small plants in Sweden, even though thepotential for agriculture and medium-sized to smaller farms to become self-sufficientin terms of electricity and heat is great. Farms have a natural stock of digestibleorganic material in form of manure or crops for example, which are constantlyavailable.

Reducing the CO2-pollution, resulting from the combustion of fossil coal for energyproduction, is important to affect environmental changes. One way to achieve a reductionis to use the oxy-fuel technology. The technology uses O2 and re-circulated flue gasduring the combustion which results in a flue gas mainly consisting of CO2. The flue gascould then be compressed and stored without environmental effects. A problem thatfollows from the compression is the risk of acidification in sensitive parts of the process.Acidification can occur because of reactions following from the contact of condensedwater and sulphur- and nitrogen-oxides which are also present in the flue gas.This report compiles and evaluates the basis of a scientific unit with the purpose ofexploring the possibilities of extracting impurities of SOx and NOx from the flue gases.The dimensions of the unit are based on basic conditions, defined for an existing oxy-fuelprocess at Chalmers, and on the results of computer modelling.

Title: Mountain birds ? a comparative study from valley to mountaintop in a northern and southern Swedish fjeld  Author: Kristian Zackrisson Abstract Main aim in this study was to increase the knowledge about birds in the Swedish mountain area. Three questions were asked: 1) Which bird species can be found during the breeding season along a low mountain slope from a forested valley to a mountaintop with bare mountain environment? 2) Do the number of species and individuals differ in different elevation zones? 3) Is the composition of bird species along a low mountain slope the same in the Kebnekaise mountains inLaplandand the Grövelsjön mountains in Dalarna? Bird census in two study sites located in the Kebnekaise mountains and the Grövelsjön mountains and subsequent analysis of the results from the bird census was the main parts in this study. Totally 20 bird species were found along a low mountain slope in the Kebnekaise mountains.

This study was conducted at the City Abattoir in Kampala, Uganda to evaluate the cleaning process, with focus on bacterial pathogens, in a pilot scale integrated bioprocess. This consisted of four steps: anaerobic sequencing batch reactors; aerobic/anoxic sequencing batch reactors; a high performance temperature controlled methanogenesis digester and a constructed wetland. The objective was to determine if this type of cleaning process could be used to clean wastewater from abattoirs in a satisfactory way. The indicator organisms for faecal contamination, Escherichia coli and Enterococcus spp. were used to investigate in what numbers bacteria could be found in the untreated wastewater and how much that was reduced in the different steps of the cleaning process. The water was analysed for Salmonella to see if human pathogens could be found and could survive the different steps of the treatment process.

The aim of this study is to have a deeper understanding about the motivations and the obstacles of an immigrant?s language learning. I have studied the problem with focus on integration and language learning. The study is principally based on deep interviews with Turkish immigrants. I have studied the question by means of a socio-cultural perspective of learning; Mead?s conceptions I, Me and the generalised other; Scheff?s conception, the social bonds and Freire?s conception, dialog and Asplund?s conception social responsiveness.

3D-modelling in AutoCAD This thesis is done in cooperation with LB-Hus in Bromölla, and have aimed to establish a digital AutoCAD model of one of the company?s house types and to find out what opportunities there are to do visualisations in the form of images directly from the programme. Modeling has been carried out so that the very construction of the house is included. Interiors and installations, with the exception of the ventilation system, have been left out in the model. The model has been created with solid models after a comparative study made between solid models and surface models to find out which option in this case was the easiest to handle and took up the least space.

Corn is an important food and feed crop in the world, in Sweden it?s up till now grown on limited acreages mainly for silage. But I think it can get more important if you can grow it also for grain, because it?s a good animal feed for example, for life stock-, pigsand poultry. On of corns advantage is that it can produce the same amount of dry matter as for example wheat, barley and rise but with 25% less water. I will examine if it possible to grow corn for grain production in the south of Sweden.

Holmen Skog has in some places in their operation area access to timber trucks with centre mounted scrapers. They make transportation more flexible and reduce reliance on contractors for road maintenance. The trucks with centre mounted scrapers have a higher tare weight, making them less productive and therefore they receive compensation with a 0.75 % increase on transportation price. The purpose of this study was to investigate what actions a timber truck with centre mounted scraper can perform with acceptable quality in winter, and to examine if it is an economically profitable solution for the truck operator and charterer. The study was done in three stages; interviews, performance analysis of the transportations carried out and an economic analysis with the help of Sven Erik Gilles spreadsheet tool. The study included the districts Delsbo and Hudiksvall.

The purpose of the present study was to examine effects of driver, vehicle, and environment characteristics on Collision Warning System (CWS) design. One hypothesis was made that the capability of collision avoidance would not be same among a driver, vehicle, and environment group with different characteristics. Accident analysis and quantitative analysis was used to examine this hypothesis in terms of ?risk? and ?safety margin? respectively. Rear-end collision had a stronger focus in the present study.

Uppsatsen tar sitt avstamp i ämnet krigsvetenskap och den förändring av försvarsmaktens verksamhet som de kombinerade uppgifterna, insatsförsvar och fredsbevarande insatser har skapat. Den del av krigsvetenskapen som uppsatsen riktas mot är krigföringens grundprinciper och tillämpningen av densamma inom de nya ramar som försvarsmakten agerar inom.Syftet med uppsatsen är att undersöka huruvida en skillnad mellan teori och praktik har uppstått gällande krigföringens grundprinciper. Genom att avgränsa området till taktisk och operativ nivå, de grundprinciper som finns i den svenska marina doktrinen och det svenska ytstridsvapnet, görs en problemformulering och uppsatsens frågeställning definieras till: Vilka skillnader kan utrönas mellan den teoretiska innebörden av krigföringens grundprinciper och den tolkning av dessa som görs inom dagens svenska ytstridsvapen?En kvalitativ metod, där litteraturstudier och intervjuer används som forskningstekniker, fastställs som lämplig metod för uppsatsen. Därefter diskuteras validitet och generaliserbarhet samt källorna ur en kritisk synvinkel.

The harness racing industry has roots hundreds of years back in time and breeders through time have changed the horses to a mix of potential, harmony and speed. Breeding has changed the conditions and created a horse that perform better and better. A risk with high-performance horses is that injuries related to training and racing may occur more often. In training and racing situations, lameness is the most common injury. There are many factors affecting the occurrence of injuries and lameness of the trotter horses, such as how the horse is trained and raced, the surface condition of the racetrack, banking and angle of the curves of the racetrack and how fast injuries are discovered and treated.

This rapport contains an examination of the energy consumption of a kindergarten, which areas that have the largest impact on the energy consumption and what can be done to reduce those areas in ways that are relatively easy and profitable. It is also analyzed if it is possible to reduce the energy consumption from today?s consumption to a consumption that fulfils the demands placed on low energy houses by FEBY.The focus has been on reducing the energy consumption of the areas ventilation, heating system and hot water system, since those seemed to be the easiest ones to affect and since the building is quite recently built.There are different kinds of ventilation systems, at the moment the building have a CAV-system, which means that the ventilation is too high during large parts of the day. There are different ways to manage the ventilation system, for example presence detection, humidity sensors, CO2 sensors, temperature sensors and season adjustment. Many of those are in the end dependent on CO2 sensors to guarantee a good indoor climate, therefore the focus have been placed on this system.

The project was made in cooperation with Coffee Queen AB, Arvika. The task was to develop and design a new cooler for the milk to Jura Impressa X9, an espresso machine. The good assistance with staff at Coffee Queen and engineers in China and at KPA in Karlstad led to a solution to the problem. It was a long road to get there, many different concepts was developed. When the day came to decide which concept to work with, the choice stood between two different technical solutions.

Dead wood is important for many species. The amount of coarse dead wood (diameter >10 cm) is much lower in managed forest than in unmanaged forests. Stumps constitute the largest proportion of the volume of coarse dead wood in managed forests. Since stump harvest for biofuel may increase, the amount of dead wood will decrease even more, which may threaten biodiversity. The first aim of this study was to compare the amounts of fine woody debris (FWD, .

The exhaust arrangement on a Scania V8 consists of one manifold at each bank connected to a twin entry turbine (8-2-2). A study in GT-Power has shown improved performance and reduced cylinder to cylinder variations using two manifolds at each bank in combination with a single entry turbine (8-4-1). This thesis work analyses the difference in performance shown in simulation and verify it by engine test.The initial work was focused on simulation in GT-Power. Investigating how exhaust manifold volume and pulses effects the turbine efficiency and the mean effective pressure during the gas exchange. To verify GT-Power simulations four engine tests with different exhaust arrangement have been made.The results from GT-Power simulation indicate that a larger exhaust volume improve the turbine efficiency.