Forest enterprises have always searched for ways to improve efficiency. For the past few years there has been an emphasis on stock-keeping levels. Increased demand for fresh round timber and the need to decrease the amount of tied-up capital has made the forest industry reduce its inventory levels. This has brought on a higher demand on the timber supply from the forest management districts concerning both delivery in time and assortment output. As a result, the flow of timber has fluctuated a lot with serious consequence for the timber supply during 1994.

SCA has today almost 300 000 hectares of their forest land planted with lodgepole pine(Pinus contorta var. latifolia). Due to initial extensive planting in the 1970ies the area oflodgepole pine forests in the thinning age has grown rapidly from the end of the 1990ies.During the years 1996-2005 first commercial thinning of lodgepole pine at SCA took place.The goal of the hereby presented study was to investigate the growth and stability in thosefirstly-thinned lodgepole pine stands a few years after thinning. Furthermore, the objectivewas to investigate the relationship between stand stability and different stand parameters.Additionally, lodgepole pine stem quality was estimated.The study is mainly based on the data collected during an inventory project carried out atSCA in 2008. Altogether 91 lodgepole pine stands in northern Sweden were measured afterthe first thinning.

The costs of logging and of transportation with truck are dominating the total cost of wood delivered at industry. To support the profitability for the members' forestry the processing and handling with the timber has to be as efficient as possible. Increased length of pulpwood in thinning is one conduct that can result in higher productivity and/or lower costs. The study is scaled as a system analysis with the aim to exemplify the differences between working with 3- and 4-meter as standard length of pulpwood, related to biological aspects, timber receipts, cost of logging and cost of transportation with truck. Important aspects are if the change is technically and biologically feasible and economically profitable.

Powder Metal (PM) gears are machine element components which operate under the same principle as conventional gears, but, due to their intrinsic material characteristic need to be designed slightly different, and its manufacturing process offers advantages previously unobtainable by conventional steel gear manufacturing methods. The use of PM in similar applications, such as synchronous hubs, makes them a suitable candidate for production in such material. The current master thesis work focuses on gear design using PM by utilizing finite element method (FEM) to reduce weight and inertia taking into account root bending strength and tooth deflection.First a topological optimization is used to determine feasible candidates for different web designs which have as objective to reduce volume, similar topologies were shown during different loading conditions; and hence, this topology was chosen as a suitable candidate. A shape optimization of the topological candidate was performed having as state variables root bending strength, independent for compressive and tensile side of the tooth loading; and tooth deflection, which in concept can be correlated to static transmission error (TE).Another aspect in this thesis analysed is the possibility to incorporate non-trochoid root geometry, a trochoid root is always present when machining with a hob, into the gear root and hence reduce the stress concentration here. Due to the use of PM, a non-symmetric optimized root can be achieved and hence be optimizing compression and tension.Results showed significantly lower inertia, for example certain results showed 40% reduced when compared to solid gear, with adverse effects as increase in tooth deformation and increase in maximum principal stress.

It is essential to reuse- and recycles residues to decrease the amount of deposit materials and reach sustainable energy use. Two ways to work towards this is to recycle wood ashes to the forest as nutrient compensation and extract biogas from combustion of biomass.The aim with this study was to decide whether wood ashes that been used for biogas upgrading with accelerated carbonation also can be used as a nutrient compensation in the woods according to recommendations from the Swedish Forest Agency (Skogsstyrelsen).The ashes that were used in this study came from Johan Andersson who works at JTI in Uppsala, who also treated the ashes with biogas. The ashes have, in both untreated and treated condition, been analyzed in this study according to contents of elements, leaching properties, hardening properties and contents of crystalline phases, to evaluate what impact carbonation with biogas has on the ashes.The accelerated carbonation led to hardening of the ash, and decreased amount of CaO- and increased amount of CaCO3. The CO2-uptake also entails a dilution of the elements, and the content of nutrients and trace elements decreases. However the results show an indication of an uptake of S from the biogas to the ash, since the dilution had a smaller impact on S than the rest of the elements.

The increasing oil prices during the last years have made it profitable to use cereal grains as a fuel. When compared with wood, cereals contain higher amounts of Cl, S and ash. The Cl and S content makes the gases from cereal combustion more corrosive than gases from wood combustion. The goal of this master thesis was to find out the variation of Cl, S and ash content for oat grain grown under different conditions. Oats was chosen because in Sweden it's considered as the cereal with the best fuel qualities.

In this thesis an energy analysis of ethanol production at the ethanol plant of Lantmännen Agroetanol in Norrköping has been performed. The ethanol plant has been studied in combination with Händelöverket, the combined heat and power plant which provides the ethanol process with steam. The purpose of this study was to determine the energy consumption for the whole production chain from grain to ethanol. The analysis has included the energy consumption for cultivation of grain, production of chemicals, the production chain for wood chips, the steam production and the ethanol plant. The grain and wood chips are both considered raw materials there for the energy content in these are not included as energy input in the system.

In this thesis an energy analysis of ethanol production at the ethanol plant of Lantmännen Agroetanol in Norrköping has been performed. The ethanol plant has been studied in combination with Händelöverket, the combined heat and power plant which provides the ethanol process with steam. The purpose of this study was to determine the energy consumption for the whole production chain from grain to ethanol. The analysis has included the energy consumption for cultivation of grain, production of chemicals, the production chain for wood chips, the steam production and the ethanol plant. The grain and wood chips are both considered raw materials there for the energy content in these are not included as energy input in the system.

This study intends to discuss what might motivate Swedish upper secondary students to read literature in English. The study was performed through interviews with both teachers and students, as well as questionnaire studies with both students and teachers. The students give different interpretations of what the definition of motivation is, ranging from definitions of extrinsic motivation to signs of their definitions leaning toward intrinsic motivation. The conclusion is that although the English language itself is not a barrier for students? reading motivation, the majority of them are not motivated to read.

The corn plant came to Europe with Christopher Columbus in the 14th century and have ever since bin cropped here, but corn haven?t bin very common in Scandinavia until recently. The mainly use for this crop silage but even corn for grain is cropped in Europe. Corn for grain is a common part of feed in beef and chicken farming. In Sweden corn for grain is pretty rare but almost 1000 hectares are used for this crop, Lantmännen Sverige is the biggest buyer of corn at the moment.

To build high-rise buildings made of timber has for long been limited by national laws, due to the lack of knowledge in engineering solutions. Frame structures made of wood has for a long time been associated with major fire hazards and consequently lower safety and this connection is still being made today. The increased environmental awareness in recent years has contributed to the exploitation of indigenous building materials, including wood from our own Swedish forests and has become increasingly common. Increased knowledge about how structures behave in fire and how they can be protected in order to achieve safe timber structures has resulted in a growing interest in these structures in the construction industry. Research in the area is constantly updated and new laws allow any number of storeys in wooden buildings in Sweden as long as the performance requirements are fulfilled.The main part of this work has involved calculations of the fire resistance and load bearing capacity of floor and wall constructions.

The main goal with this thesis report was to come up with ideas of how to make the use of energy more effective and thus save money for the company.First a survey was made to find out where and how the energy consumers were divided within the company. The results were then used in calculations to find out how much money that could be saved and how long it would take to get back the investments.There is a big potential in saving money by recovering heat from the UV-lamps with a heat exchanger. It would also even out the pressure in the factory which is a source to heat loss and a cause for discomfort amongst the employees. It?s possible to save 105 000 kr in a year and the money needed for the investments is 600 000 kr.By using the recovery air more effectively the company could save up to 250 000 kr a year in lowered heat purchases, but this would require the use of automatic dampers.If you reschedule the running times for the wood chipper and invest in some kind of load management, for example Sydkraft?s ?Energidirigent? you can save at least 42 000 kr.

The aim of this master thesis was to create a dynamic model for the processes in a solid fuel boiler of the moving grate type. Another aim with the model was to keep it as simple as possible but still able to catch the dynamics of the processes in the bedplate of the boiler. The creation of the model had its origin from drying and combustion equations used in earlier modeling work of boilers. The represented model has been used to simulate different kinds of disturbances in a boiler and different ways to control the boiler. These tests show that controlling a number of parameters in the bed of the boiler is an effective way to keep the grate stable during disturbances.

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.

The efficiency of the harvesters work is more often reviewed, than the work of the forwarders. In a local Stora Enso office the differences between the harvesters reported volume of timber, and the actual volume delivered to the industry had been noticed. Therefore, the decision was made to do a review on the forwarders work. The review was conducted together with a worker from Vmf Qbera, who is working daily with wood measurement, in order to get a valid evaluation of the logs. Eight sites were included in the survey, and on each site 50 logs were marked. Approximately one third of the marked logs were pulpwood, and the remaining logs marked were timber.