The gaming market has become the fastest growing market for leisure and is one of the most popular forms of homeentertainment. This has generated a media debate about how people are affected by gaming and concernes how we are affected by the violence that may occur in games. Games proponents argues that gaming is the future of teaching and computer games are becoming a sustainable and popular instruction strategy. Some studies have long used computer games for educational purposes. By interviewing high school students in focus groups as qualitative research, I studied their attitudes towards computer games as a learning tool.

Uppsats för avläggande av filosofie kandidatexamen i Kulturvård, Trädgårdens hantverk och design 21 hp.

This thesis is the result of the investigation and solution of a mechanicalproblem regarding flywheel malfunctions. A flywheel is, in short, a devicethat relies on a rotating object?s moment of inertia to store energy overshort time spans. This project is part of the development of a fourthflywheel prototype at the division for electricity at Uppsala university,which uses magnetic levitation to keep a hollow cylinder rotating at veryhigh speeds inside a vacuum chamber. Should the magnets fail however, orsome other error occur that leads to an uncontrolled state of rotation, thecylinder needs to be stabilized mechanically by a device usually referredto as ?back-up bearing?.

Good comfort for the driver of a construction machine is crucial. Gearshift comfort is an important part of the total comfort. Volvo Construction Equipment Components has a simulation environment of the powertrain, SimPow, which is implemented in Matlab/Simulink. SimPow is mostly used for simulation of control strategies and performance. In order to be able to study gearshifting comfort, Volvo has an interest in developing new models for SimPow.

This study was made to compare and distinguish any differences in olfactory recognition and host plant adaptation between two strains of cotton leaf worm, Spodoptera littoralis. The populations used were established in Egypt and Benin, Africa. The documentation consisted of information about (1) each of the strains development through the larval stage up to pupation on diets of cotton, clover and cowpea. (2) Their oviposition preferences as adults between cotton, clover, cowpea, maize and cabbage. (3) Electroantennographic recordings to quantify any possible responses to plant volatiles. Throughout the diet experiments the larvae from the Benin strain showed significantly a better development between artificial, clover, cowpea and cotton respectively, while the Egypt strain had significance between artificial, cotton and cowpea/clover as diet. Also noted was how the strains substantial development of weight differentiated if fed the cotton diet, followed by the cowpea diet showing that the Benin strain would develop a higher body mass on a cotton diet as well as on a cowpea diet. This trend was however switched once the pupal stage was reached, where the Egyptian strain contained a significantly greater body mass than the Benin strain on the artificial and the Benin strain a greater on cowpea, which suggests that in the end, the Benin strain develops significantly better on cowpea while the Egypt strain develops better on an artificial diet. During the oviposition experiment that both stains showed a clear difference in hierarchy of host plants considered suitable for oviposition, where the Egyptian strain is significantly more attracted to clover than the Benin strain. Also showed with electroantennographic recordings and significant values was the higher sensitivity the Egypt strain had towards (E)2-hexenal, (E/Z)-b-ocimene, (Z)-3-hexenyl acetate, Nonanal, (-)-linalool and ?-myrcene when compared to the responses from the Benin strain..

The euthropthication of the Baltic Sea is a threat that is beginning to be taken seriously by the governments concerned. In Sweden, regulations concerning the allowed nitrogen (N) concentration in the effluent water from wastewater treatment plants are being tightened up. The Rimbo wastewater treatment plant has been imposed to reduce the annual mean concentration of total N in the effluent water to levels below 15 mg l-1. A more and more common way to reduce the nitrogen level in wastewater is to let the water pass through a wetland. This study investigates the possibility to build this kind of wetland at the outlet of the Rimbo wastewater treatment plant.A prestudy of the topography, soil characteristics and groundwater flow indicates that the land area in question is well suited for the construction of a wetland.

This project aims at investigating if the use of UML as a support to small-scale development ofan embedded system is relevant. The investigation is conducted by using UML during the initialphase of the development ofTelfafill, a filling machine by the company ?Telfafill AB?. The aimof the development of Telfafill is to separate the user interface from the control unit. In additionto this main objective, Telfafill AB would like possible changes to, and additions of,functionality of the filling machine to be investigated.Within the boundaries of this project, the development of Telfafill reached a full requirementspecification of the proposed system, and contact was made with potential external developers.No prototype construction had been started when the project ended.

The European Council agreed in 2008 on a climate and energy package to combat global warming. This package is valid for each EU member country and means that greenhouse gas emissions must fall by at least 20% and the EU's energy use to 20%, consisting of Renewable Energy in 2020. The Swedish Government has set stringent climate and energy with the intention to set an example for the rest of Europe. For example, renewable energy sources account for at least 50% of energy use and our climate emissions to fall by 40% by 2020. A combination of these goals and a steadily rising oil price has led to an increased demand for wood fuel in the form of such branches and tops.

A growing interest for the climate and the environment has led to an increased interest forenvironmentally friendly and renewable energy sources, such as biogas. Planning new biogasplants requires a decision basis including facts about approximate amounts of biogas possibleto produce at the plant. The purpose of this thesis is to develop a model that calculates theapproximate biogas and digestate production from a planned or existing biogas plant.Developing the model required a literature review and studies of calculations concerningbiogas and digestate production performed by WSP Sweden AB. As a complement to themodel development, facts about substrates for biogas production were compiled through aliterature review. In addition the methane potential from selected materials was determined bybatch experiments.

Bakgrund: I och med att Basel II har instiftats i Sverige så måste finansiella institutioner beräkna sin marknadsrisk på sina portföljer. Detta kan göras genom olika VaR metoder. Dessa ger dock olika uppskattningar på marknadsrisken. De finansiella instituten får använda sig av den metod som de anser reflektera marknadsrisken bäst. Det finns dock ingen metod som utsetts till standard.Syfte: Syftet med detta arbete är att jämföra olika VaR-metoders skattning av marknadsrisken utifrån verkligt utfall, för att urskilja vilken metod som är funktionsdugligast.Avgränsningar: Denna undersökning inkluderar fyra olika VaR metoder.

The quality of bread wheat is a large subject to study. The quality rests on two legs. The first one is the inheritance of specific characters, which can be influenced through plant breeding and type of cultivar. The other one is the environmental influences, such as crop rotation, nutrition, harvest and storage. The latter factors are possibly to affect through cultivation practices, while other factors are not possible to influence on for the grower, such as seasonal changes of weather and the soil content.

Göteborg Energi has a surplus of district heating during spring, summer and fall. The heat surplus is due to a constant production of waste heat from oil refineries and heat from waste incineration over the year. It would be desirable to increase the demand for heat and the uptime for the newly built combined heat and power generation plant, Rya Kraftvärmeverk. One alternative could be to integrate Rya Kraftvärmeverk with a pellet production facility. By producing heat, electricity and pellet in a joint process the energy use can be decreased.

Phosphorus is essential to all plants and is taken up from the soil as the ion H2PO4 - (and to some extent HPO42-). Plant availability depends on, among other factors, the soil pH. In order to provide for plant available phosphorus, it is applied as mineral fertilizers and farmyard manure. However, that causes phosphorus leaching from arable land to surrounding surface waters and lakes and contributes to the eutrofication. There are three types of soils in Sweden that are at higher risk of contributing to phosphorus leakage.

Denna uppsats är skriven höstterminen 1997, då ett nytt läromedel började utvärderas i Linköping. Den svenska skolan har sedan en tid haft bristande natur- och teknikundervisning i de lägre årskurserna. Den Kungliga Vetenskapsakademien gav vissa av Linköpings skolor uppdraget att i lärarlag arbeta med ett nytt material, för att kunna se dess fördelar och brister. Materialet heter Science and Technology for Children (STC) och är framtaget av den amerikanska organisationen National Science Resource Center. Sedan utvärderingen av STC har läromedlet bytt namn till NTA (Natur och Teknik för Alla).

Emissions of radionuclides to the atmosphere can lead to wet deposition on plants in the event of rainfall. An increased level of radioactivity in the plants may occur due to interception and retention of the radionuclides. If the content of the plants is above the threshold limit value, entire yields may have to be destroyed. In order to prevent contamination or decrease the content countermeasures can be taken. The impact of the biomass, leaf area index (LAI) and growth stage of the plant on the interception and retention is important to know in order to decide which countermeasures to use. Weather may also be an important factor. In this work the interception and retention of 134Cs and 85Sr by spring wheat, ley and spring oil-seed rape was studied.