There is a great need to reduce nutrient leaching from arable land into lakes and oceans. By using several different types of models it has previously been possible to describe nutrient losses in a catchment area with a minimum unit of sub-catchment level. At present, it is instead desirable to model a smaller catchment with an opportunity to re-connect the results to the corresponding fields in the catchment. Such models already exist but they are not fully able to properly describe Swedish conditions and land characteristics in our region.With the approach of creating such a model, SLU has developed a project with this work as its first stage. The model is expected to be created under the working name SWE-model which stands for Soil Water Environment and is in this first stage supposed to apply the SOIL model in catchment scale. During the procedure to describe the first step in the process of developing such a model adapted to Swedish conditions and which works in the catchment scale with an area of about 10-30 km2, focus has been set on calculating the transport of water flow from different hydrological response units. Regardless of the processes occurring in the soil after the water has been added, it is assumed that all the water which flows from each simulated unit is drained.In the first step the hydrologic response units were identified based on land use and soil type in the study area. With the help of a script with functions that retrieve and transform data, certain units were chosen for Simulation. The script was also created in this project. Finally, the model results were aggregated and summarized for each unique unit, for each sub-catchment, and also for the whole catchment.From the results it is possible to see similarities in the flow dynamics between modeled and measured data. The efficiency coefficient has been calculated to correspond to the mean of the measured values for the whole Simulation period. With an automated calibration process the model should be able to perform better. The volume error gives an indication of overestimation from the model..

The borehole heat exchangers of today suffer from poor thermal and hydrodynamic performance. The purpose of this thesis is to improve the performance of ground source heat pump systems and thermal energy storages by increasing the energy efficiency of the borehole heat exchangers. For this reason, the annular coaxial borehole heat exchanger (CBHE) has been analyzed. This type of heat exchanger is interesting in terms of both thermal and hydrodynamic performance. A model has been set up in the program Comsol Multiphysics in order to investigate the heat transfer characteristics along the borehole.

Severe floods caused by heavy autumn rains in year 2000 raised the question whether measures to reduce the damage from high water levels, in the area surrounding lake Glafsfjorden and along the river Byälven down to lake Vänern, are possible. One option is to reduce flow resistance along the river and thereby lower the maximum water level a given inflow would cause. Good knowledge of hydraulic and hydrological conditions is necessary in order to estimate the effect of such flow-reducing measures. In order to quantify such effect a 1-dimensional hydraulic flow model has been set up for the river Byälven using the software package MIKE 11. The model is more detailed, especially concerning topography and bathymetry, than earlier models used for studies of the river.

In this work, a method was developed and evaluated for calculating the life of welds under the influence of fatigue loads from a vibration environment. Typically, a shaker table is used for testing a component against vibration loads. The shaker table creates a vibration environment that is defined in the frequency domain by a power spectrum.Similarly, a virtual vibration table can be used to calculate the same type of load environment, which can then be used to calculate the expected lifetime. The benefit of this method is that it can be used in design, as well as in Simulation of tests before physical verification tests are carried out.Today there are methods for calculating fatigue life of non-welded base material, but since many components contain welded joints, there is a need to apply this method to those types as well. To achieve this, the thesis combines two different areas, which together provide a method for fatigue assessment of welds using a virtual shaker table.The methodology is carried out by modeling the component, and its welded joints, in a finite element program.

In this report I will describe how an art-directed fluid effect for motion picture can be achieved. This effect will be an explosion with a visual style that is congruent with Pixar's movie Up. To begin with I will analyze the visual components that are used in Up and control the fluid Simulation to get the desired visual style. I will briefly explain the background of my thesis, why it is interesting to create designed effects and why it is hard to design fluid effects. In the method I will explain my work process and some of the challenges that arises.

This report covers the conceptual design of a new one person hybrid vehicle that is to be fast and convenient to drive on the roads. The vehicle is most of all supposed to be used as a commute vehicle but can also be used at other occasions as well.During the work with this project the group has focused on three larger areas, the outer design (body), wheel chassis and an ergonomically designed interior. The group was not able to just create these parts in 3D to get a trustworthy vehicle, hence number of other components and details were also created to get a better entirety.The outer design starts with idea generation and sketches and ends with a 3D model which is rendered to show how the final product is going to look. The design of the body has been going on during the entire work process due to new ideas and improvements that seemed interesting and had to be changed.The wheel chassis also started with idea generation, research and sketches. It ended up with a simulated 3D model which later on was mounted on the vehicle body to show how the vehicle is going to perform during usage.

This paper presents a study of the computer game ?Minesweeper?. The aim of the game is to search through a rectangular area of mined squares without hitting any mines. By using a strategy based on making every operation as safe as possible, series of the game have been simulated. The size of the playground is four times four squares.

Det finns en rad satt att beskriva gallringsformen. Ofta används begreppet gallringskvot i dessa sammanhang utan att närmare ange vilken metod eller definition som använts for att beräkna den. Detta kan lätt leda till att missuppfattningar uppstår. Denna studie belyser olika definitioners känslighet for bland annat beståndsstruktur, gallringsform och stickvägsavstånd. Studien innehåller dessutom en jämforelse mellan olika metoder att mäta och uppskatta gallringskvoten i ett bestånd.

AbstractThis work was assigned by a technological company that manufactures gas detectors in which the sensor signal is processed using digital filters. These filters have been developed by a consultancy firm which converted previously used analog filters to digital filters. The purpose of this work has been to analyse inadequate, and sometimes erroneous, documentation from the project in order to provide the company with know-how and tools for further improvement of their products. The work has been done using the Simulation software COMSOL which was bought solely for the project. Analysis showed serious flaws as well as pure errors in the consultant?s documentation.

Many traffic incidents are due to the driver?s lack of attention, resulting in dangerous lane departures, either sliding off theroad or into the oppose lane. These kinds of incidents often have serious outcomes, which has led to much effort being concentrated on preventing or lessening the damages when the incident is already a fact, for example by installing safety belts and air bags. These measures may be considered to be acts of so-called passive safety. Active safety on the other hand, means that the safety systems intervene before the incidents have occurred.

Essingeleden in Stockholm is the most heavily congested road segment in Scandinavia and it is ofgreat importance for as well traffic within the city as for transit traffic. The capacity of Essingeledenand Norra Länken is not enough to accommodate all traffic. At times it is not moving at all, whichresults in long queues and an augmented risk of accidents. Consequently measures for increasing thecapacity on E4/E20, which will reduce congestion and the risk of accidents, are implemented byTrafikverket. In fall 2012 one lane of three at Pampas will be closed and so will the exit fromEssingeleden to Norra Stationsgatan, called Parkeringsbron.

When protection zones for wells are delineated, it is important to acquire good knowledge about possible travel time from different points in the catchment area to the well. Often, simple analytical methods are used for estimating travel times and the assumption is made that the hydraulic conductivity is relatively homogenous within the aquifer. Nevertheless, many aquifers are strongly heterogeneous which may lead to differences between estimates and actual travel times. As a part of the process to develop improved methods for delineating protection zones for groundwater supply wells, a tracer experiment was performed in a glaciofluvial esker formation in Järlåsa. On the basis of the experiment, a numerical flow model was created for the test site.The purpose of this master?s thesis was to apply the flow model to an aquifer where the hydraulic conductivity shows great variability and should be described by a stochastic distribution.

Abstract The accident in 1986 at the nuclear power station in Chernobyl, Ukraine, dispersed radioactive cesium over large areas of Europe. The half life of 137Cs is 30 years and this radionuclide also behaves like potassium, which means that it can easily be taken up by the vegetation or be adsorbed in to the structure of clays, principally illitic clays. When radiocesium decays ionizing radiation is emitted, which is harmful to humans that are exposed, either directly or indirectly through food intake. It is there-fore important to know what happens to the cesium that is dispersed into the environ-ment. In this project a Simulation model was constructed to simulate the adsorption and transport of radiocesium in the soil and plant uptake.

The stability of railway embankment is essential for safe transport. In order to ensure safe transport, water should be allowed to freely drain. Furthermore, as the engine driver has to be able to see signs, and people working on the embankment are supposed to easily see flaws on the rails to ensure safety for the passing trains, plants should not be allowed to grow on the embankment. In Sweden there are 12 000 kilometers of railway tracks and 25?30 % of them are treated for weed control every year.

Volvo Construction Equipment AB Components Division i Eskilstuna är mitt inne i ett omorganisationsarbete där fabriken byggs om från funktionsverkstad till flödesorienterade grupper detta för att effektivt möta den växande orderingången. När gruppernas värdeflöden tydligtgjorts återstår ett intensivt arbete med att optimera ledtider, lagernivåer och produkter i arbete med mera. Ett kraftfullt verktyg för att stötta detta arbete är diskret händelsestyrd (DE) simulering. Det har genomförts flertalet DE simuleringar tidigare på företaget, då främst av konsulter. I den nya fabriken finns en önskan om att utföra detta arbete själv.