Svenska Kraftnät is (together with the other transmission system operators of the Nordic power system) responsible for keeping balance between the generated and demanded power in the Nordic power system. Spontaneous load variations and system disturbances, however, lead to power imbalance followed by frequency variations. The frequency deviations can be limited to an acceptable level by the spinning reserve, mainly by hydro power control. But there are also other system properties which have a great influence on the frequency and system stability. The frequency and voltage dependence of the loads have a direct influence on the power balance.

This report is a description of a developed educational simulator over rail vehicles and its components. The simulator is a hardware-based prototype over a door system on rail vehi- cles. System specialists and technicians will use the prototype. The Simulator should give the user a technical demonstration on how components work in a door system. The proto- type consists of motor, switch, relay and sensor.

The equine hoof is often manipulated in purpose to achieve a better stride or to reduce the weight on damaged tissue. The living tissue in the hoof can?t store energy as glycogen and is therefore depending on a continuous supply of glucose for its energy production. The purpose of the study was to determine if wedging (i.e. elevating) the heel could influence the hooves glucose and lactate consumption/production. Five standardbred horses were trained to trot on a treadmill without getting physical or mentally tired.

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.

This thesis work is the last part of the Master of Science education inmechanical engineering at KTH, Stockholm.The aim of this project was the development of a Multi-zone modelfor NOxformation in Diesel engines. Because of the stringent emissionlegislations, great effort is made to decrease the fuel consumption and theharmful emissions of internal combustion engines. Computer simulationsplay a decisive role in this context because they substitute the expensiveand time-consuming laboratory tests.The model is based on a multi-zone approach and uses the wellknownExtended Zeldovich Mechanism which gives a relation to calculatethe NO formation rate using the concentration of different gas speciesinvolved in the process.All the most important phenomena involved in the Diesel combustionhave been modelled. A special attention is then paid to the equilibriumconcentration calculation; this is a significant part of the model whichstrongly influences the following steps.A Simulink model has also been developed. This second version isbased on the previous model and it is made especially to allow theconnection with other external softwares, GT-power in this case.

To render outdoor scenes with lots of vegetation in real time is a big challenge. This problem has important applications in the areas of visualization and simulation. Some progress has been made the last years, but a previously unsolved difficulty has been to combine high rendering quality with abundant variation in scenes. I present a method to mathematically generate and render vegetation in real time, with implementation in the scene graph Gizmo3D. The most important quality of the method is its ability to render scenes with many unique specimens with very low aliasing.

Inclusion body disease (IBD) affecting boas and pythons is a serious and common disease. Boas can be clinically healthy carriers, which makes control of the disease difficult. The causative agent has not yet been confidently identified, and therefore there are no serodiagnostic tests available. Today, histopathologic examination of tissue biopsies is the recommended antemortem diagnostic method, but there are several disadvantages. The objective of this study was to compare the sensitivity of two diagnostic methods ? liver biopsies and blood smears, and to evaluate ultrasoundguided needle biopsy of the liver.

This report is a description of a developed educational simulator over rail vehicles and its components. The simulator is a hardware-based prototype over a door system on rail vehi- cles. System specialists and technicians will use the prototype. The Simulator should give the user a technical demonstration on how components work in a door system. The proto- type consists of motor, switch, relay and sensor.

The future of the forest owners? associations are intimately coupled to the development in family forestry. Forecasts have been made that predicts that the number of forest properties for sale on the open market will increase as the interest among the children of the property owners is considered to decrease. The associations are also affected by continuing individualism in the society which may affect attitudes to as well as interest in membership. The objective of this study was to study the attitudes among grown-up children of members in a forest owners association towards overtaking the forest property as well as membership in a forest owners association.

Forskning med hjälp av mikroskopi har med tiden ställt merspecialicerade krav på utrustning som används. Utrustningenhar blivit mer bättre men samtidigt också dyrare. Enhög kostnad innebär att avancerad mikroskopi inte kan användassom ett utbildningsverktyg inom grundutbildning.Dagens studenter tvingas på så sätt förberedas för framtidensforskning genom att använda gårdagens utrustning.I detta arbete visar vi hur virtuell mikroskopi kan användasför utbildning och forskning. Virtuell mikroskopi kananvändas som komplement, eller möjligtvis ersättning, förbefintlig undervisning. Vi har demonstrerat detta genomatt utveckla en pilotapplikation som simulerar de två metodernaFLIP och FRAP.

The chow-chow breed is considered to have a low fertility and this report is an in depth study of the reproductive functions of this breed in Sweden. Only 53 % of the Chow-chow matings results in litters. Previous studies of other breeds in commercial kennels shows mating results around 85-90 %, but this has not been investigated in hobby kennels and most Chow-chows which are bred from in Sweden, are kept as family pets. Contrary to most other breeds, Chow-chows show a seasonal reproductive pattern and most litters are born in the autumn. The influence of the month of mating on pregnancy rate and litter size was found to be not significant, but can be considered a trend. Thirty-nine females with previous known fertility problems where studied. Some of them had reached puberty extremely early, at an age between 4-5 months, and many of the bitches showed great fluctuations in intervals between oestrus cycles. Some of the females showed abnormalities such as very short oestrus intervals of only 2-3 months, probably without ovulating.

Inledning: Många företag genomför idag någon form av prognos som underlag för deras beslut.Det kan handla om prognoser för hur mycket marknaden kommer att efterfråga, hur storakostnader företaget förväntas ha eller hur mycket personal som kommer krävas.Problemformulering: Hur använder företag prognoser i sin verksamhet?Syfte: Syftet med den här uppsatsen är att beskriva och förklara hur prognoser används i företag.Metod: Den här studien har byggt på en kvalitativ forskningsstrategi. Arbetets forskningsansatshar varierat mellan en induktiv metod och en deduktiv metod. Uppsatsens empiriska material harinförskaffats genom semistrukturerade intervjuer på två utvalda företag; Galenica AB och SAABtraining and simulation.Resultat och slutsats: Undersökningen visar att företag använder prognoser som grund för attfatta beslut. Prognoser används främst som grund för budgetarbetet, men företag upprättar ävenprognoser över andra faktorer som påverkar företagets framtid.

SAAB Aerotech division FGR in Arboga builds and develops equipment and components used in both military and civilian applications. To build a test system for a specific project that SAAB is responsible for requires a simple signal generator that can provide a pulse modulated signal. The need to buy a new advanced signal generator for example from Agilent is not as profitable as the instrument is expensive and contains features that SAAB does not require in their applications and test systems. That was the reason why SAAB offers two students a thesis where the goal is to construct a signal generator in accordance with what SAAB requests.This thesis contains several different phases. The first step was a meeting with our supervisor Mats Bergman and by reading the data sheets for components to be used in the project, with these information and specifications that we have received from SAAB we started to construct the signal generator.What we did during the construction work was to simulate and draw a schematic to be able to design the circuit board.

Sand pits are a valuable habitat which can hold many sand living species including several endangered ones. As many sand habitats with exposed sand are declining, sand pits have a potential as a substitute habitat. This study was conducted to see what effect the area of a sand pit has on species number and composition of ground beetles (Coleoptera: Carabidae). Also, the effects of other environmental variables were tested, for example the proportion open sand, vegetation cover, sun exposure and tree cover. The study was conducted in the county of Uppsala in 2008 and included 13 sand pits with areas between 200 and 180,000 m2.

This study concerns the type of vegetation selected by cattle grazing on semi-natural pastures, and whether the selection depends on the nutrient content of the vegetation or on other factors. The study was carried out in three different semi-natural pastures in the Uppsala area during June, July and August in 2006. The three pastures were first surveyed, mapped out and divided into sub-areas with regard to the type of dominating vegetation. The vegetation types identified were: wet, mesic, dry, wooded, pasture with signs of former cultivation (arable). Within each vegetation type three 1x1 m sampling plots were laid out. The grazing behaviour of the cows was recorded in a behaviour study.