Biogas is a renewable energy produced through anaerobic digestion, which means that organic matter is degraded by microorganisms under anaerobic conditions. The produced biogas can then be used for cogeneration, electricity, heat or upgraded to vehicle gas. Eskilstuna Energy & Environment AB has four digesters at Ekeby water sewage treatment plant, Eskilstuna. One of the biogas reactor (RK4) is equipped with a jet-mixing system while the remaining digester uses top-mixing. The mixing system is an important parameter to achieve optimum operating conditions for the process regarding gas production and degree of digestion.

The Anybus CompactCom modules are today using the Anybus NP30 processor. These modules are used for communication between industrial machines and larger network protocols. The communication loads on these systems are increasing every day and the limiting factor for the system is the processor.HMS, the company that develops the Anybus CompactCom, has shown interest for a benchmark test between the old processor and a new processor, ARM Cortex-M3. This project includes that benchmark. To be able to get results that reflect reality a test environment was created to simulate Anybus CompactCom conditions.

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.

The DuPont formula is one of the most well known and basic tools used for financial statement analysis and is highly useful for understanding firms strategies and operating environment. Previous studies on American listed companies have also shown that analysis of the changes in the DuPont components is useful in forecasting contexts. In this thesis we test whether disaggregating the change in return on net operating assets provides incremental information about future performance for Swedish listed and not listed companies. We find that the change in asset turnover is a leading indicator of increased profitability for both listed and private companies, regardless of size. We also find evidence that the usefulness of the disaggregation for understanding future performance is greater in capital intense industries and lesser in service industries..

This report evaluates whether an interpreted high-level garbage collected language has enough information about its memory behaviour to make better cache decisions than modern general CPU hardware.With a generational garbage collector, depending on promotion algorithm and generation size, around 90% of all objects never leave the first generation. This report is based on the hypothesis that, because of the low promotion rate, accesses to higher generations are sufficiently rare not to benefit from caching.To test this hypothesis, we built an Operating system with a Scheme interpreter in kernel mode, where the interpreter controls the cache. Generic x86 PC hardware was used, since it allows fine-grained control of cache decisions.Measurements of execution time in this interpreter show that disabling the cache for generations higher than the first does not give any performance gain, but rather a performance loss of up to 50%.We conclude that this interpreter design is not an improvement, but cannot conclude that the hypothesis is false in general. We suggest building a better CPU simulator to gather more data from which to make better caching decisions, moving internal interpreter data structures into the garbage collected heap and modifying the hardware to allow control in the currently rigid dimension of where data is cached---for example separate control of instruction and data caches and separate data caches for different areas of memory..

This Master Thesis has been conducted as an assignment of the Swedish Defence MaterialAdministration and the Swedish Armed Forces and aims to examine the Target Location Error(TLE) of a Forward Observer System. The targeting accuracy of the system is vital if the systemis to be used as a sensor for precision munitions. The analyzed system, EOI (FOI 2000), wasdelivered to the Swedish Armed Forces in 2007. The targeting sequence starts with deciding theposition of the system with a GPS-receiver, continues with methods where the north direction issettled and ends by measuring the distance, direction and elevation to the target. When allparameters have been measured the system calculates the position of the target.

This degree project has been carried out in cooperation with Gedevelop in Helsingborg.Gedevelop has developed a camera that can calculate the weight of a liquid glass mass.Because of the density and viscosity changes in the glass, the weight information issometimes incorrect given. Glass industry is today addressing the problem by an operatorperforming a manual weighing of a few bottles which, in turn, calibrates the camera system.The project aimed to develop an automated system to control the weighing of glass bottles forglass industries. This system must be so flexible that it can be easily mounted on plants withdifferent production equipment around the world.The project includes design and construction of equipment that meets the requirementsformulated together with Gedevelop. Work has been done both in Halmstad and Helsingborgand has included both calculations and review of the theory to understand the forces thatinfluence the design of different construction parts. A prototype was produced that meets theoperating requirements for the design and can be used in testing features.

The thesis is about exploring possibilities for developing a standardised system solution for micro businesses, this since most of the micro business lack proper system solutions, a contributing factor of this is price and also incompatibility between the solution and the business itself. The system solutions we will refer to are solutions which task is to cover the most important needs that a micro business might have on their system. The main goal with this research is to see if this is possible, and if so, how the developers should think to take it further. We chose to do this by identifying the most significant of needs a micro business has when it comes to this type of system solution.In this thesis we will present three needs which were evaluated and brought forth through the analyses of various interviews and observations we had done during the study. The interviews took place at respective company with their employees and consisted both closed and open questions with our main focus on the open questions because we wanted to obtain as much information from the respondents as possible from several viewpoints.

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.

The running of gas turbines with low emissions causes high pressure pulsations to arise in the combustion chamber. These pulsations are high amplitude sound vibrations. At some frequencies these are harmful to the gas turbine. Hence these pulsations are monitored to avoid operating conditions where pulsations are specifically harmful. It is necessary to expose the system of known pulsations to verify the functionality of the monitoring process.

SUMMARYPrevious research has shown that there is a connection between the doorways and postoperative wound infections. Despite recommendations from Socialstyrelsen and the individual hospitals' PM there is still high traffic in the operating theatres. In a hybrid theatre environment combined X-ray techniques of surgery, resulting in it being further two categories inside the operating theatre. This may generate an increase in traffic flow. The study is a prospective, non-participant observation study conducted in the spring of 2013 at a university hospital in western Sweden.

The purpose of this master thesis was to study the water system for mechanically cleaned water at Skärblacka mill, in order to find and evaluate possibilities of using energy more efficiently. The thesis also includes an evaluation of the software tool ?Pumpanalys?Skärblacka mill produces pulp and paper. The large amount of water required is cleaned mechanically through filters and called mechanically cleaned water (MR0). The MR0 water is pumped out to the factory by four crude water pumps.

In today?s society climate change has grown to one of the largest global issues. To reduce emissions of greenhouse gases, large changes of the energy system are required. An increasingly popular solution is investments in local production of renewable energy resources like wind, solar or geothermal power. The following report examines the possibility for implementing a solar power plant on the new hospital Nya Karolinska Solna. Two different technologies for extraction of solar energy has been studied, solar thermal collectors  to meet the need of heating and solar cells to satisfy the need for electricity linked to operating the hospital building.

In order to produce grain in an economically rational manner numerous decisions have to be made. One of these decisions is what tillage system to use. The cost of the tillage system is a large part of the total cost in grain production. Different tillage systems result in different distribution of fixed costs, operating costs and timeliness costs. The price of the produced grain and cost of inputs also affect the best way to produce grain.

Buildings worldwide account for 40 % of the total energy use. Climate change is of increasing importance, but few are willing to reduce their standard of living or get a higher cost for the change. Energy efficiency of existing buildings gives the greatest benefit economically and environmentally. The real estate company Klövern AB manages 46 properties in Karlstad. Heating is the major cost of the total operating costs of real estate. Rising energy prices increase the need for Klövern AB to improve energy efficiency and to investigate alternative sources of heat.