AbstractThe dependency of fossil fuels in the transport sector causes large emissions of carbondioxide. This problem can we reduce by using vehicle gas from digested solid manure and leftover of pasture. I have studied the potential for this in the county of Västernorrland. Thepurpose is to investigate how much vehicle gas that can be extracted.One central, large scale digestion and upgrade plant should be placed in Härnösand. Theamount of pasture and manure that is economical and practical available is enough to produce2,7-3,5 millions Nm3 vehicle gas.

The purpose with this work is to investigate the cost to produce piglet in a case study company. The starting point is going to be the agriwise (www.agriwise.org) calculation which I am going to change and adapt to the case study company. To day the pig market is bad but we have probably reached the bottom. The market has started to rise. It is no business to produce piglets today.

Due to increasing regulations regarding new diesel vehicles particulate matteremissions the new Scania truck, Scania Euro 6, has been equipped with a particulatefilter. This component effectively stores the particles in the exhaust gas but must becleaned in order to prevent itself from clogging. The filter is cleaned through aprocess named regeneration which is a thermodynamic process in which thetemperature of the filter is raised through fuel supplied to the exhaust gas.The purpose of this thesis is to contribute to the development of improved controlstrategies of the temperature during the regeneration process through thedevelopment of model-based controllers. These controllers are designed in order tohave good performance in stationary as well as automatic regeneration.In order to develop these model-based controllers a model of the system isconstructed. The model is described as a linear thermodynamic grey-box model withflow varying parameters, showing good results in validation.The model provides a simulation environment during the controller design, which isfocused around the development of linear regulators with the exhaust gas mass flowas a scheduling variable whose size determines controllers? mode of operation.

The use of fossil fuels such as coal and gas are a contributor to the global warming. The climate change is a worldwide problem with far reaching consequences that is believed to be very expensive. The United Nations has been introducing a framework convention on climate change. One component of the convention is the Kyoto protocol. The protocol is obligating the developed countries to decrease their emissions of greenhouse gases by 5.2 percent during the time period 2008-2012.

AbstractIn urban societies people spend more and more time indoors, which put great demands on the indoor environment. If the ventilation is to manage the removal of unwanted substances in the indoor air, a good mixing of the air is required. The question arises that, whether the buoyancy forces will counteract a good mixing of the indoor air or not?This report aims to clear up the difficulties whether you need to consider the buoyancy forces or not, when adjusting a ventilation unit. For studying the indoor mixing of the air a two dimensional model is constructed in COMSOL Multiphysics.

The power system modelled in this thesis work has been developed for simulationwhen e.g. the production in some part of the power system is changed. The powersystem has been modelled according to the swing mass of the system, the frequencydependency of the load and the turbine governor. The model determines the systemfrequency, the period of regulation and the power exchange between the differentsubsystems in the Nordic synchronized system.In this model the system frequency is assumed to be the same in all different parts ofthe power system and the voltage conditions in the power system are neglected. Forthat reason power swings does not occur between different subsystems in the powersystem, which usually occur as a result of the swinging connection between thetransmissions line.

Several technical solutions are ready to step forward as the new generation of propellant, and this report aims to explore the possibility of commercializing fuel cell cars. The report is based on current research and data from today's technology and engineering solutions that are estimated to be commercially realized before 2020.A mapping of today?s different fuel cell options has shown that the most suitable fuel cell option is the Proton Exchange Membrane Fuel Cell, which uses hydrogen as fuel. The report is focusing on a techno-economic well-to-wheel analysis of hydrogen and the energy balance and costs in a system perspective. The basis for this analysis consists of two centralized methods of production, steam methane reforming (SMR), and alkaline water electrolysis.

This thesis is written on behalf of Skanska, Väg- och Anläggning Stockholm Mälardalen, vid Nya Karolinska Sjukhuset i Solna, NKS. The report has resulted in recommendations for the method of soil stabilizations of soil nailing, excavation of slope and fiber reinforced shotcrete, which is the most suitable method from a safety and a cost point at the NKS.The aim of this thesis was to investigate whether fiber reinforced shotcrete increases slope stability, with the focus being on the total stability. The main goal was to investigate which method of soil stabilization is the most suitable for the slopes that are analyzed in this report. Through studying literature, the authors have gained an understanding about the theoretical background for the given problem. Through calculations and analyses of the slopes, safety factors have been acquired.

The purpose of this essay is to investigate if the companies listed on Nasdaq/OMX Stockholm Large Cap use the earnings management phenomenon Big Bath Accounting to a greater extent when a change of management (CEO) is made.Management tends to use earnings management when there is a bonus plan linked to the result of the company. To gain maximum bonus the management will try to manipulate the result in a way that in a long term maximize their utility. Through the earnings management technique Big Bath the management is given the possibility to take one large cost as a one-time expend, even though the cost is supposed to run over several financial years. This, of course, within the legal framework. A big bath may occur when there is an impairment of goodwill, tangible and/or intangible assets or larger provisions for future expense, or both of them at the same time..

A well, situated on Listerlandet in the western part of Blekinge in Sweden, has a very high content of nitrate. Water with a too high content of nitrate is hazardous to human health, in particular to small children. The area surrounding the well is mostly drained agricultural land with some larger farms for chicken and mink. The well takes its water from the bedrock and is deeper than most other wells affected by nitrate. The bedrock in the area is dominated by limestone with a relatively high flow of water.This thesis was performed in order to find the source of the nitrate.

Reverse logistics is getting more and more attention both from companies and the public. It is an area with the possibility for companies to do good in the eyes of the public. This work focus on the return system of a one-way handling material called the loading ledge. The loading ledge is developed by IKEA as a substitute for the EUR-pallet in transports from suppliers with a long distance and even flow and in transports from suppliers with short distance and uneven flow. The loading ledge is made out of 100 % recyclable plastic.The purpose of this work is to find the most efficient set-up for recycling of loading ledges within IKEA on a European level from a transport and handling point of view considering aspects like cost, environment, time and, from an administrative point of view, user-friendliness.Who will the participants of the set-up be, where will they be located, which transports are needed and which income and costs does the set-up generate, are questions that will be answered.

Profit in first commercial thinnings of today is hard to achieve. This is because of prevailing pulpwood prices and because of high costs of logging and transport. To reduce these costs higher productivity is advocated. One way to increase the productivity is the use of multi-tree handling harvester heads. The aim of this study was to calculate logging and transport costs in first thinnings, where multi-tree handling has been used.

The goal of this master thesis project was to develop computer models of some plausiblepretreatment techniques and to assess the potential benefits/costs of using pretreatment andanaerobic digestion for waste management of organic waste from a system perspective. Forthis purpose a computer program called ORWARE has been used. ORWARE (organic wasteresearch) is a program for making life cycle assessments of waste management. As the mainpart of the project work the ORWARE system has been provided with three new models ofpretreatment techniques. The additions consist of: One model of pretreatment with ultrasound,one model of thermal hydrolysis and one model of a screw press.

This study is a thesis project for the program Civilingenjör och Lärare at KTH. The study was conducted in spring 2014 in collaboration with Komplementskolan AB which has developed the educational material Studi.se, the focal point of this study.The overall aim of the study is to increase the knowledge of the participant teachers? conception and use of the educational material Studi.se. The second purpose is to increase knowledge about the forms of use some of these teachers apply or claim to apply when using Studi.se. Theoretical framework used is constructivism and the notions of Piaget: adaptation, assimilation and accommodation.

The aim of this thesis is to investigate how the literary site Vulkan.se affects the conditions for publishing, distribution, incorporation in value systems and feedback in the literary process, as it appears in Lars Furuland?s model of this process. The purpose is also to propose an updated version of the model. This is achieved through a qualitative testing of Furuland?s theory.