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662 Uppsatser om 3 dimensional wood composite - Sida 4 av 45
Hållbara uppvärmningsalternativ för Grinda Wärdshus : En studie om uppvärmning med pellets och flis
This report is a bachelor's thesis of two students from the Energy and Environment degree at KTH Stockholm. Grinda is an island situated Stockholm archipelago. Skärgårdsstiftelsen is landowners and manages the area. Grinda Wärdshus, a guest house located in the island, currently uses an oil-fired boiler as a heating system. The aim of this thesis is to investigate whether wood chips or pellets is, from a sustainability standpoint, a suitable heating method for the guest house.
Fuktkvotens inverkan på oljeupptag och pigmentinträngning i tall (Pinus sylvestris L.) och gran (Picea abies L. Karst) vid impregnering med Linotechmetoden :
Wood has always been an important material for people, and it is used for many applications. As for example, fuel for cooking and heating houses, construction materials and for constructing means of transport. Since wood also is a material that with time biologically degrades due to activity by micro organisms and wood fungi it is important to find ways to protect and further lengthen the life span of the material when in service. One method is to decrease the amount of water in the material by impregnation with an hydrophobic oil. The Linotech method which uses only pure linseed oil is one such possible method.
The aim of this study was to investigate the possibility to at the same time impregnate and stain/colour wood samples of pine and spruce by using the Linotech method.
En studie av utvecklingen av drivningsnettot i skogsbruket :
This master thesis consists of an investigation of the profitability per hectare in privatly owned forest land. The investigation is based on data collected from Skogsstyrelesen, Riksskogstaxeringen and Skogsforsk. During the last twenty years the prices on pulp wood and saw log have substantial decreased, but during the same time the the volumes from final felling have increased and the cost for felling has decreased, this investigation shows how the netprofit per hectARE after final felling has changed between year 1980-2005 This investigation shows that that the netprofit has stayed on a stable level during the years 1985-2005 even though prices pulp wood and saw log decreased. Much indicates that the demand of swedish pulp wood and saw log will continue to be strong or even stronger wich will give increased prices and an higher netprofit after final felling in the future.
Pelletering av tallspån : grundläggande studier
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.
3D-avatarskaparen
This project report shows the work around a mockup to a three-dimensional avatar-making application. An avatar-making application is a computer-based software program in which it is possible to create your own personal virtual character. The possibility to use three-dimensional avatars can in the future be essential for adding extra personal information or characteristics to social communication over the internet or over mobile phones. The problem of transforming a physical form and reconstruct it to a virtual basis has been an important problem to solve for many companies and software developers in the, for instance, virtual worlds area. Methods and ideas over making this transformation is the key throughout this project.
Stöldskydd
To save energy it?s popular to build houses with low energy loss. In these houses the walls are keeping a lower temperature in the external side which leads to a higher relative humidity. In addition more material, such as wood studs, are used which means that there is more moisture to dry. More moisture in combination with higher relative humidity may pose a higher risk of microbial growth.
Epixylic lichens and bryophytes in young managed forests : substrate preferences and amounts of dead wood
Dead wood is important for many species. The amount of coarse dead wood (diameter >10 cm) is much lower in managed forest than in unmanaged forests. Stumps constitute the largest proportion of the volume of coarse dead wood in managed forests. Since stump harvest for biofuel may increase, the amount of dead wood will decrease even more, which may threaten biodiversity. The first aim of this study was to compare the amounts of fine woody debris (FWD, .
Vad tycker skogsägare om virkesinköpare och inköpsorganisationer? : utveckling av ett skogsbolags tjänster och köpverksamhet till privata skogsägare
The private forest owners play a key role in the supply of round wood to the Swedish forest industry. Today it is a keen competition between forest companies about the wood from private forest owners. In order to get access to the wood from the private forestry you need to be an attractive collaboration partner, who can offer long-term collaboration, service at top-level, and acting for good prices to the forest owners.
This work aims at analysing the situation on the market today. It gives Sveaskog purchase department a good view of the forest owners? opinion in general about the existing purchase activities.
Forestry service level and timber prices are determining factors for a successful relationship between forest company and forest owner.
Inverkan av olika joner och jonconcentrationer på porstorleksfördelningen i trämassa-fibrer
The basic ingredient of paper is the individual wood fibers. The property of the fibers depends on a variety of factors e.g., method of pulp production and processing. The final sheet quality depends in part on how the fibers interface between each other and therefore factors that affect the fiber size are of interest.The flexibility of the fibers depends in part on the pore water i.e., the fiber swelling. The sheet becomes less flexible at low water content which gives a loss in strength. Thus it becomes desirable to increase the water uptake.The experimental investigation described in this report consists of exposing the wood fibers to different ions and ionic strength and then measure the pore size by thermoporosimetry where a DSC (Differential Scanning Calorimeter) is used.
Hur såg Birkas hamn ut och vilka transporter behövdes?
What is located on the bottom in the water outside of Birka? Remains of a water palisade or jetties and other constructions.Birka a Viking Age town that existed between AD 750 and 975 was located on the northwestern part of the small island of Björkö, in the Mälar archipelago of the Baltic Sea in Sweden. The Town was protected onshore by a hill fort and a town rampart. It is a widely spread assumption that Birka had a water palisade as a part of its defense. There are logs and other remnants on the bottom of the lake dating back to the Viking age.
Grupperingar i en nysammansatt klass
The purpose of this paper is to try to get an understanding of the underlying causes and reasons that students starting in seventh grade junior high school seek out a particular group, and the extent to which they do so.The work is based on the questions: How do students perceive the meeting with their prospective bench-companion in a new composite class? What should a teacher consider when it comes to bench placement in a new composite class? Do the students change, and if so to what extent, friends when they start high school? What are the factors that affect/have affected the students' choice of friends? How large a role does the school play for pupils relationships? What thoughts and feelings do the students have regarding new encounters?I have conducted in-depth interviews with six adolescents in grade seven as the basis for the understanding of how students relate to group selection and group affiliation, and I have then compared this material with previous research on the subject. Furthermore I have availed myself of literature in social- and group psychology.The conclusion which has emerged is that the most important component of a group-process is the sense of solidarity and security, and the results show that students largely retain their old relationships rather than adding new, when they start high school. Hence the teacher plays an important role in ensuring that any imbalance in the group is offset and make sure that nobody is excluded, but also to help make room for new groups and be aware of the sensitive and responsive phase of life that the young people are in..
Undersökning av modulationsscheman för existerande bredbandsteknologier
In this thesis some different modulation schemes for xDSL-techniques are compared. The investigated techniques are ADSL, G.lite, ADSL2, HDSL, SHDSL and VDSL. The modulation methods used are DMT, CAP and different versions of PAM. Several broadband techniques also use Trellis Coded Modulation (TCM) to increase the coding gain of the transmission. For each one of the different modulation methods the signal-to-noise ratio is calculated for generating a bit error rate probability of 10-7.
Clear-cut and substrate characteristics important for the occurrence of the beetle Upis ceramboides
Disturbances, such as fire and wind, are important for saproxylic beetles (= beetles depending on decaying wood) to gain substrate in boreal forests. Clear-cutting is an example of a man-made disturbance. Measures such as prescribed burning have been made to resemble natural disturbances. The aim of this study was to see which clear-cut characteristics are important for the occurrence of the saproxylic beetle Upis ceramboides.
This is a species favored by open habitats and is said to respond positively to forest fires. The distribution area in Sweden for this species has decreased during the last two centuries and I wanted to see if there were differences between clear-cuts in Hälsingland, where it is very
rare and decreasing, and Norrbotten where this study was conducted.
Skogsbristen i Smålands bruksskogar : en studie av träkolsförbrukning vid Storebro Bruk 1793-1850
The forest in the county of Småland has been utilised for a long time. One of the most
important forms of utilisation of wood has been charcoaling for the benefit of the iron
industry. Shortage of forest in relation to the iron industry, was discussed already in the 17th century in Sweden. The aim of this study was to analyse the purchase and consumption of charcoal at Storebro Bruk, an ironwork in Småland, during the period 1793-1850, as well as analyse the shortage of forest at the time. To determine the utilisation of the forest in the area, I have used historical sources from Storebro Bruksarkiv.
Tidsåtgång för rundvirkesmottagning på Södra Cell Mörrum
This study was made for the round wood transport company MT Transport AB. Time studies were made in order to analyze time consumption on the mill site for timber trucks delivering round wood at the Södra Cell Mörrum mill. The most interesting was to see how much of the time spent at the factory that was waiting time. In three weeks the study was going on and the drivers were clocking it themselves..