This study investigates the role of yeast in green crop and its impact on the aerobic stability of silage. Fresh crop was collected from 15 farms in southern and middle parts of Sweden during the summer 2014; samples from the primary harvest was collected from eight farms and samples from the first regrowth harvest was collected from seven farms. The grass was ensiled in 1.7 l glass silos. After three months of ensiling, silos were opened and silages were stored aerobically for 10 days. Samples from both harvests were ensiled in completely airtight silos, but samples from the second harvest were also ensiled in slightly ventilated silos. Chemical analyses and yeast counts were performed for fresh crop and silage.

This master's theses was carried out on assignment from Stockholm Vatten AB as a part of a project developing new waste water treatment techniques. The goal of the theisis has been to evaluate an anaerobic membrane bioreactor for treatment of waste water from Hammarby Sjöstad. The bioreactor has not been heated and the main interest has been to study the gas production, power consumption and the reduction of organic matter and nutrients.The system has been completed with a reverse osmosis unit and a total of four batch runs have been made with good results. The use of reverse osmosis allows nutrient in the waste water to be reintroduced into circulation as the reverse osmosis concentrate can be used as crop nutrient.The membrane unit is of VSEP ("Vibratory Shear Enhanced Processing") type and an extensive membrane test has been conducted. This so called L-test helped determine the most suitable type of membrane for the system to allow a higher ±ux and thus lower power consumption.

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.

With background in the rapidly growing need to find solutions for sustainable energy production and the increasing interest for wind power, this report was written. With take-off point from the wind power plant Big Glenn, which has been built in the harbour of Gothenburg, a model of the adjacent power grid has been created in Simulink/SimPowerSystems. Parameters for the power grid and its components has been provided by Göteborg Energi Nät, that has also been the supplier of measurement data of produced power, the power need from loads in the vicinity, voltage levels, current values and also the variation of power factor at the wind power plant.The SimPowerSystems model has been used to perform simulations of power flow in the grid. These simulated values have then been compared to the measured values to verify the functionality of the model. Further, the model has been used to perform simulations of a grid fault, which causes a voltage drop.

This thesis is an evaluation of a new design concept for statorfeets in Gallejaur hydro power plant. Founder of the work is Vattenfall AB Vattenkraft. During the 70- and 80´s nuclear power began to be phased in to the Swedish grid, which meant that hydropower became an important source of rules. The generators began running in so called intermittent operations instead of basic operations, which meant 300-600 start/stop per year instead of one-ten numbers start/stop per year. In order to deal with the thermal forces that arise at every start and stop suppliers began to mount so called sliding joints, which is to take advantage of these forces and maintain the stator shape.

AbstractConsider a ?uid being heated from below. The heating leads to an upward convectiveforce that is counteracted by the viscous forces of the ?uid. If the convectiveforce is large enough in comparison to the viscous forces the ?uid will be put in anunstable state.

Today?s wind power plants are only compensated for their reactive power consumption at no-load. As the wind power plants grow bigger the amount of reactive power they need also increases. This is no longer a problem that can be ignored, especially as the net owners are beginning to charge the reactive power they transport.In this thesis a couple of different methods of compensation and their prices will be discussed and evaluated. Problems, such as self-excitation, that can occur if one fully compensates the wind power plant will also be brought to surface.

Today?s wind power plants are only compensated for their reactive power consumption at no-load. As the wind power plants grow bigger the amount of reactive power they need also increases. This is no longer a problem that can be ignored, especially as the net owners are beginning to charge the reactive power they transport.In this thesis a couple of different methods of compensation and their prices will be discussed and evaluated. Problems, such as self-excitation, that can occur if one fully compensates the wind power plant will also be brought to surface.

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.

Hydropower is the largest renewable energy source available in today's society. Operation and production is handled by high-tech electronics. This thesis is done on behalf of Statkraft Sweden AB who wants to explore the possibility of replacing the hydraulic cylinder with an electric actuator, generally as well as a case of a small power station on the river Nissan. Whether it is the chaplain or francis turbine vanes are actuated by hydraulic cylinders. Because of Gustavsberg hydropower is inconstant operation, this report is based on power calculations, which are read and computed according to the available hydraulic diagram.

This is a report written for an examination project C-level, on the subject of energy. The examination project is a product of the FVB Sweden AB (district heating bureau). It started with a meeting with Stefan Jonsson FVB Sweden AB, were he explained the content of the project, and from this a presentation of the problem was made. The problem that needed to be solved was how they could control the valves in the system to provide heating to everyone in the system. The valves are often oversized so the pump in the heating plant would have to be enormous to be able to provide enough flow to be sufficient, if everyone in the system had there valves fully opened. I came up with two solutions to the problem, one was a wireless network that could keep track of the valves and the other solution was an extra sensor that was placed on the radiator.

The aim of this research is to find out what environmental impact a wave power park has on the Swedish west coast by creating a consultation paper (?Samrådsunderlag?) for the Lysekilproject at Uppsala University. To highlight the complexity of the problem a system analytic approach was used and illustrated by a Causal Loop Diagram.The overall assessment of the Lysekilprojects wave power park at the Swedish west coast is that it will have a low impact on the environment. This is due to the relative small size of the wave power park and some technical solutions made with the environmental aspect in mind. Artificial reefs and a sanctuary for marine species are effects created by the wave power park and in the longer term the impact will give access to an untapped source of renewable energy, wave energy.

AbstractConsider a ?uid being heated from below. The heating leads to an upward convectiveforce that is counteracted by the viscous forces of the ?uid. If the convectiveforce is large enough in comparison to the viscous forces the ?uid will be put in anunstable state.

The debate on the future of Nuclear power in Sweden has increased with the discussion on global warming. The uncertainty of fossil fuel- and carbonprices the latest years has aroused considerable interest in Nuclear from power companies, industry and politicians. Nuclear power plants have negligible CO2 emissions and are not directly affected by increased price of emission rights and fossil fuels. The future power production needs to reduce its emissions of greenhouse gases to become sustainable. The purpose of this study is to examine the value for power producers to have the option to invest in Nuclear power and how a Nuclear power venture would affect future electricity prices. The study uses two methods, a traditional cash flow model and real option analysis, to estimate the value of Nuclear power.

This thesis treats the normative power of the European Union and its affect on Macedonia. The main purpose has been to look closer with the use of the application of Ian Manners theory of normative power on the Macedonian case. The focus will be to answer the following questions: Does the European Union act as a normative power in relation to Macedonia, if so, how are these values diffused? Has there been any effect of the spreading of these values? Based on six interviews and the available material of European Union strategies for the Macedonian membership I have attempted to understand to what extent the European Union?s normative power has had an influence in Macedonia. The result of my analysis is confirmation of the European Union as a normative power in Macedonia and the understanding of the methods of application..