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697 Uppsatser om Wood density - Sida 6 av 47

Förbättrat råvaruutnyttjande vid kvalitets-sortering av timmer : utvärdering av analysprogrammet Stockholmen för automatiserad timmersortering i dimensions- och kvalitetsklasser hos BARO WOOD AB

The aim of this thesis was to analyse BARO WOOD AB:s timber measuring and quality sorting and to evaluate the analyse program Stockholmen. The purpose was to get a better understanding for the quality sorting made at BARO WOOD AB today, analyse differences in center board quality from logs with a good quality and logs with a bad quality, suggest new sorting criterias developed from analyses made with Stockholmen and to evaluate the program Stockholmen. All analyses are based on data gathered in a test sawing made at BARO WOOD AB in June and July 2002. The test sawing was made on four different diameter classes and every diameter class consisted out of A or M-grade logs, with a better quality, and B-grade logs with a lesser quality. The logs where sorted out with BARO WOOD AB:s existing quality criterias.

Utvärdering av Hultdins prototyp för portabel bro (drivningsbro) :

Stronger demand has been put on forestry to show environmental considerations during harvesting. This is especially for crossings of brooks with sensitive elements and great care should be observed when they are to be crossed during harvesting by logging machines. For that reason Hultdins has constructed a portable bridge that can be used for those occasions. The bridge has been developed in accordance with wishes from SCA forest, since they have a great deal of brooks in their forests and in private forests from where they buy part of their wood supply. The aim for this report is to investigate if this portable bridge can be of interest for the forestry market. The research has been made at SCA skog in Medelpad and Norrskog in Medelpad.

Fåglar i urbana miljöer : kvaliteten på urbana habitat och om beståndstäthet är ett bra mått på habitatkvalitet

The urbanization of the world is increasing. How it affects bird populations have been well studied during the last decade, and comparisons between urban and non-urban habitats have been carried out. A common method for measuring habitat quality is to calculate the population density. This method is easy to use, but have been criticized during the last couple of years. In this study, data of population densities was compared with data on reproduction success.

Skattningar i gallringsskog med hjälp av flygburen laserskanning : beräkningar med massaslutenhet

This master?s thesis is a remote sensing study of an area-based method used to detect forest in need of thinning by use of laser data and field samples. Only pine-dominated forest has been included in the study and height limits were set to match empirical restrictions. The study area was in the municipality of Älvsbyn (Latitude 65° 40´ N, Longitude 21° 00´ E), in northern Sweden.The Swedish authority Lantmäteriet is currently laser scanning most parts of Sweden, providing new opportunities and applications. The primary aim of the national laser scanning is to create a new elevation model, useful in consequence analysis of climate changes.

Miljonprogrammet : mytbildning, arkitektur och förnyelse

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, .

Traditionella och samtida bottenbj?lklag: med fokus p? isoleringsmaterialen

The survey aims to shed light on traditional and contemporary bottom floor frames, their construction and different insulating materials; mineral wool, wood shavings and charcoal. The purpose is to analyze and discuss the similarities and differences as well as the pros and cons with a focus on the construction and the different insulating materials. The work has been limited to comparing two different wooden floor frames. The first one is based on a real floor frame from an older building, this example is presented as the traditional floor frame in this study and are from around 1940. The other floor frame is presented as a contemporary floor frame and is based on wood building type descriptions and literature.

Mätning av träddelar och flis på Dåvamyran, Umeå energi :

The moisture content in 10 deliveries of tree parts and 10 deliveries of wood residues were measured with different methods to analyze the quality of procedure used at Dåvamyran today. At the same time a survey was made on the measure procedures used at heating plants in Sweden The majority of the heating plants in Sweden use weight and moisture content as base for payment but at some plants only volume. The moisture content is usually estimated by drying wood chips in an oven but few plants a visual estimation is used. At few plants moisture content is estimated spectroscopicily. The techniques using near infra read light and other electromagnetic are still at a test stage. The methods of measurement used today are quit unreliable for the individual deliveries and there is a risk for systematic mistakes.

Vedlevande lavar på döda grenar på levande träd i produktionsskog

Saproxylic lichens in managed forests have less substrate available than in unmanaged forests due to the shortage of dead wood. However, a suitable substrate for these lichens could be dead branches on living trees. To this date, there has not been any systematically collected data about theabundance of dead branches on living trees and the lichens growing on these branches in managed forests. The aim of this study was to see where dead branches were located on living trees of Pinus sylvestris and Picea abies, how large the surface area of these branches was and what lichens grewof wood on these branches. The study was made in Finspång, Sweden, where 11 forest stands of P.sylvestris and P.

Lantbruket som energiproducent : tekniska, ekonomiska och miljömässiga förutsättningar för fjärrvärmeproduktion med lokalt skogsbränsle

A third party access to district heating networks has been proposed in Sweden, to increase the competition on the district heating market. Such third party access could create opportunities for the agricultural sector as an energy producer. This study describes the technical, economical and environmental prerequisites for a farmer cluster to build and run a heating plant, fueled with local wood fuel. The heating plant in the described scenario is 8 MW and will supply a village of 1000 houses, and is fueled with wood chips exclusively. Supplying a heating plant with fuel puts high demands on the logistics, since there need to be a continuous flow of fuel. In the scenario, wood residues from felling and thinning is stored in stacks in the forest, and a few times a year chipped and transported to a storage area at the heating plant. In the study, an estimation of the profitability has been made by estimating the cost of the investment, personnel, operating and maintenance costs and costs for the fuel and ash handling.

Konkurrens mellan rådjur och dovhjort

The main purpose of this report is a first step to cover the scarcely investigated subject of interspecific competition between roe deer, Capreolus capreolus, and fallow deer, Dama dama. The report focuses on the distance between individuals of roe and fallow in the study area as well as which factors that is affecting the variation in distance depending on fallow deer group size and changing population density over time and in two areas. For additional information the history of the populations, such as harvest and distribution, is also investigated. The report came to the conclusion that interspecific competition between the species do occur. The elevated distance between individuals of the two species is clearly significant. The most important factor affecting the distance seemed to be the size of the fallow groups.

Trädens utveckling efter att de har lämnats som naturhänsyn : tillväxt, mortalitet och strukturell förändring 6-18 år efter avverkning

Today green tree retention, together with leaving dead wood, is a common practice with the aim to reduce negative impacts on biodiversity and environment due to clear-felling. To better understand whether this conservation practice also makes a long-term difference, it is important to know what happens to these trees after harvest. Few studies have made an assessment of what happens to retention trees over a longer time period. In this study I inventoried retention trees that were left at clear-cuts six, twelve and eighteen years ago. I carried out a re-inventory of 57 retention patches (divided into free-standing tree groups, small swamp forests and edge zones) and free standing dead trees, spread over 25 previous clear-cuts in central Sweden.

Mindre studie av en ny gallringsmetod i stamtät förstagallring av gran i södra Svergie

The main purpose of this study is to investigate how to reduce the high, and every decade raising, pre-clearance cost. The pre-clearance is today carried out with a brush saw and paid per labour hour. All small trees not suitable for pulpwood are removed to simplify the later work of the harvester. The study compares the economic results from thinning of four parcels each treated differently regarding harsh or light pre-clearance and extraction of only pulpwood, or both pulpwood and fuel wood. In this type of spruce stand the study indicates that a lighter pre-clearance, followed up with both pulpwood and a fuel wood extraction, has a much better economy than the traditional method of hard pre-clearance and only pulpwood extraction..

Omfattningen av icke avverkade områdeni samband med slutavverkning :

This final thesis is performed on commission of Torsby forestry administration, Stora Enso Skog. Stora Enso Skog is one of the major forestry companies of Sweden. The main business area is located in and around the region of Bergslagen. During the last decade the practice of forest management has rapidly changed due to a new forest legislation. The new law has resulted in that the production goal is equal to the environmental goal within forestry.

Hur ofta bör småhus sotas? : En samhällsekonomisk analys av ändrade sotningsfrister

Sweden recently changed the national regulation of chimney sweeping. This study has two purposes. The first purpose is to evaluate the effect of this reform to see if the new regulation has led to an effect in terms of increased chimney fires in single-family houses and for the wood-burning and oil-burning stoves, respectively. The second purpose is an updating of a previous study (Mattsson 1994) of analysis of society´s benefits and costs of different alternative sweeping frequencies for wood-burning and oil-burning stoves. This study also has a secondary purpose to examine the extent to which the local sweeping rules vary with climate conditions.  Mattsson, based on his results, proposed that the sweeping requirements for oil-burning stoves should be reduced from twice a year to once every second year and for wood-burning stoves the sweeping should be reduced from four times to once each year.

Blästring av trä : Ett materialbibliotek av blästrade och ytbehandladeträytor

In my thesis I have sand blasted different type of woods - ring-porous and diffuseporous deciduous tree species and conifers - to show different results depending on the species, the direction of the grain and the effects of surface treatment of a blasted surface.The results of my tests were sometimes unexpected, such as that the sand from blasting almost completely disappeared, that all wood surfaces after blasting exhibited a much lighter or paler surface than before and that the diffuse-porous tree species showed differences in hardness between the beginning and end of annual rings.By creating a library of different kinds of wood and sandblasted surface treatment, I have created a reference bank that I will be able to use me in the manufacturing of interiors, furniture and other objects..

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