A change towards using more biofuels than fossil fuels is taking place in Sweden, and in many other parts of the world. This makes the use of fuel pellets increasingly popular, causing a greater demand for sawmill sawdust products. There is a trend towards the use of multiple types of shredders, instead of a single type in each sawmill. The purpose of the study was to characterize the different flows of saw particles that can be found at Sävar såg when cutting thick or thin wood with different cutting techniques. The saw particles size, shape, moisture content and heat value were analysed by the cutting stations: first cutting fast and slow, second cutting fast and slow, grading fast and slow and planning.

This report compares two different types of insulation with regards to fire and moisture. The materials were tested for the company Fiskarhedenvillan AB, for a wall and a roof construction that the company currently uses in the establishment of Sweden's first certified passive house for international standards.Their current material, Rockwool, is compared to a relatively new material on the Swedish market called SEALECTION Agribalance sold by the company ISO Green AB. The material is a type of polyurethane insulation. This insulation material would result in a more efficient execution of the construction as it provides waterproofing and is applied more easily than Rockwool. From a fire standpoint, literature studies and discussions with fire experts led to results.

För att ha en chans att ändra trenden med ökande utsläpp av växthusgaser är internationella samarbeten nödvändiga. Därför har EU genom miljökvalitetsmålet Begränsad Miljöpåverkan satt krav på högsta tillåtna utsläpp av växthusgaser. Att sänka energianvändningen för upp- värmning är ett steg i att även sänka utsläpp av koldioxid, som är en av växthusgaserna. Sänkning av energianvändning kan göras på flera sätt, bl.a. genom att öka tjockleken på isoleringen eller återvinna värmen i frånluften. Men dessa åtgärder ska inte helt okritiskt göras.

Syfte: Att mäta kontrastkänsligheten på en multifokal kontaktlins, med tre olika additioner för att se om kontrastkänsligheten ändras med olika additioner.Metod: 19 personer deltog i studien. En Biofinity multifokal CD (center distance) kontaktlins valdes till studien. Testet gjordes med tre olika additioner, en låg addition på +1,00 D, en mellanaddition på +1,50 D och en hög addition på +2,00 D och även med en kontaktlins utan addition som också var Biofinity. Mätning av hög- och lågkontrastvisus 10 % gjordes med samtliga kontaktlinser.Resultat: Medelvärdet för högkontrastvisus var -0,15 logMAR för linsen utan addition, och något högre dvs. sämre visus med addition.

During the late 1800s fire suppression became increasingly effective in northern Sweden which led to decreased areas of fire-disturbed woodland and successive changes in the structure of forests. In the long run this can pose a serious threat to fire-dependent and fire-favored species. Today some fire-prone forest reserves are burned as a nature conservation act. Often partial cuttings are made before burning, with somewhat different motives. The purpose of the study in Långsidberget nature reserve was to give a general picture of forest history and its affect on today?s forest condition, and to show how partial cuttings affect burning conditions and results. Långsidberget is located close to areas that were colonized during the Middle Ages.

Abstract The purpose of this degree project is to examine what impact working with physical objects has on children?s learning process concerning addition. We want to explore what addition strategies can be exercised using the game ?Twice as much?. We have observed children in school year 1.

Decomposition of organic matter is a critical process in the ecosystem, which involves many essential biotic and physical parts. Decomposition is therefore an important process both above and below ground. The rate of decomposition is dependent of many environmental factors for example: pH, moisture and supply of oxygen. The decomposition can therefore be affected by large scaled environmental influences, such as acidification and climatic changes. The root litter in the forest is in different ways affected by acidification, liming and manuering.

Syfte: Syftet med denna studie var att se om presbyopin, det vill säga minskningen av ackommodationsamplitud, utvecklas likadant i båda ögonen. Syftet var även att se om en ojämn addition i vissa fall gav bättre subjektiv respons än en binokulär jämn addition.Metod: Studien innefattade 33 deltagare där samtliga var mellan 43-57 år. Med hjälp av en RAF-stav mättes den monokulära ackommodationsamplituden för höger och vänster öga med push-up/push-down metoden. Utöver detta gjordes en binokulär och en monokulär additionsbestämning. Skilde sig resultaten åt från dessa additionsbestämningar fick deltagaren bestämma vilken styrka som subjektivt gav bäst upplevda synskärpa.Resultat: Resultaten visade att 11 deltagare hade en skillnad >0,25 D i ackommodationsamplitud mellan ögonen.

Energy price are on the way up to a high level that will not diminish in the future make us to focus more on the sustainable development for a better solution of residential houses. Passive house or low energy housing are one of the solution to make residential more environment friendly, in same time it´s a financial security using less energy, and saving money. The last 10 years in Germany and all around Europe the concept of passive house been developed, and people aim to know more about these concept that leading the market more attractive for passive houses. A passive house is a well designed building highly insulated and air tight with mechanical ventilated system for the whole building envelope that minimizes the use of energy for heating [1].The housing company Mimer has chosen to invest in low energy consumption in every new housing project.  These future plan projects are decided to use less than 75 kwh per square meter annually in purchased energy [2].This thesis is about new constructed passive houses, and focuses on the evaluations of the temperature, and moisture condition for attic, external walls and joist.

Chapter 1 defines the aim of the project and gives a general orientation about ground heat extractors. In chapter 2 physical processes that could be expected to be involved in the heat transport around a ground heat exchanger are discussed. It is shown from a literature study what amount of moisture transport due to thermal gradients there could be expected in a ground heat exchanger. The conclusion is drawn that the moisture gradient (Sr) is of same magnitude as the driving temperature gradient (°C). At the expected amount of increased moisture around the pipes the moisture transport could be considered to have a little effect on the brine temperature.

Wood pellets are an upgraded product of residuals from several wood processing industries, for example saw mills and pulp industries. The pellets are produced by pressing the milled and dried sawdust to cylindrical units with a higher density than the initial raw material. Pellets have great benefits compared to the raw material: high energy per volume, good transport and storage properties and homogeneity. Several parameters collaborate in the whole process, which makes it complex. Wood is a heterogeneous material, chemically and structurally dependent on wood parts, habitat and storage procedures.

When the Eolshällproject was completed for the first time, a great deal of moisturedamage was discovered. Therefore the structure completion was removed andreinstalled. The project was originally planned to cost a total of 126 million SEK, but thefinal costs landed on 271 million SEK. What caused this failure? Were the designs poor,was the technology used too advanced, or was the project not managed properly?Based on the Eolshällproject, theses will be presented about what may have caused themoisture damage.

Aspen (Populus tremula L.) and goat willow (Salix caprea L.) are two important tree species in the aspect of nature conservation. Due to the elimination of forest fires, a former negative attitude towards deciduous trees in forestry and a strong herbivore pressure, these tree species have been negatively affected during the last fifty years. The aim of this study was to investigate whether the occurrence of aspen and goat willow could be related to either human impact or to site properties, such as ground moisture and vegetation type. A side study included an inventory of a number of cyanobacterial tree lichens on aspen and goat willow in order to try to relate the occurrence of these lichens species to stand history and stand properties. The study was performed in Hamra State Forest in northern Dalarna. Nature reserves were compared with stands in managed areas.

Hårdgörning av trä syftar till att göra materialet hårdare. Detta går att åstadkomma genom komprimering, det komprimerade materialet tenderar dock att återgå mot sin ursprungsform då materialet utsätts för fukt om ingen låsning sker. Låsningen kan ske mekaniskt i en treskiktskonstruktion som motverkar träets fuktrörelser. Dessa skivor har dock visat sig vara instabila och tidigare försök har uppvisat deformationer i form av kupning. Denna undersökning syftar till att utreda förutsättningarna för att använda komprimerad asp samt att ta fram underlag för framtagning av en kommersiell produkt.Praktiska tester har genomförts för att studera hårdhet, återfjädring och densitet hos det komprimerade virket.

This report is the result of a degree project in building engineering, at an advanced level. The project evaluated a building from a technical and historical point of view, and focused on its energy consumption, particularly the energy used for heating. The building in question was a small apartment building in Strömsholm, Sweden. It was made in 1902, from vertical logs, a not so common form of the traditional log house. The goal of the project was to evaluate if the energy consumption could be reduced in accordance with building preservation regulations, that is without damaging any of the building?s cultural or historical values.The building was surveyed with the help of archive and literature studies, interviews and inspections.