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2171 Uppsatser om Springback and density of the compressed wood. In addition - Sida 2 av 145
Effekt på värdeutfallet av sågad vara vid övergång från 30 till 60 cm moduler : - en fallstudie av Moelven
The purpose of this study is to explain how the value of sawn wood changes when sawn wood are cut in 30 respective 60 cm lengths. The raw material into the saw mill will mainly be bucked in 30cm and 60 cm modules. There will also be two alternatives where the timber will be bucked special lengths, 370, 490 and 550 cm but also in 490 and 550 cm.The method used for the study is to simulate both cutting and sawing the woods. For cutting the simulator Timan is used and for sawing the simulator Timberopt is used. When data is generatedfrom the simulators, calculations of some key figures is done and also how much the revenue need to be increased for the sawn wood in order to cover for the increased costs of changing sawn woodfrom 30 cm to 60 cm modulesThe conclusion is that the single biggest reason, impacting the value of the sawn wood is the cutting at the saw mill.When going from 30 to 60 cm modules, the impact will be that the customers to the saw mill must pay more to increase the revenue by at least 10% for the sawn wood in order to justifice the changein production.It is also possible to increase the value of the products further by bucking the timber in three lengths, 370, 490 and 550 cm, in order to get 12 % increase of the share of longer sawn wood (>= 480 cm)..
Skogsbrandens påverkan på död ved :
Fire is an important ecological factor, but its consumption of coarse woody debris, CWD, has hardly received any attention. In this study, I investigate the consumption in relation to the time of initial flame exposure and propensity for continued combustion of standing CWD of pine (Pinus sylvestris).
Two types of CWD were studied. Firstly, wood that had been dead for one to ten years. Secondly, wood that had been dead for several decades. In the burning experiments, logs of approx.
Trä som fasadmaterial ? behandling och beständighet
Since prehistoric time man has used wood to build their environment. The material?s availabilitycombined with its good mechanical properties has often made it the material of choice. Like allmaterials exposed to natures degradative processes the properties of wood decreases over time.Rot, UV radiation and attacks by insects and pests damage wood if not protected. Since we wantwhat we build to consist, optimizing our building materials durability is of great interest.Techniques and methods for increasing the endurance of wood have been developed in severaldifferent places and for a long time.
Epoxidised linseed oil as hydrophobic substance for wood protection : technology of treatment and properties of modified wood
Public concern about the release of toxic compounds from wood-based products drives legislation towards enforcing industries to find and use more sustainable solutions for wood treatment. Plant oils are good alternatives to treat wood, minimizing or even neutralizing the impact on the environment. Wood modification with epoxidised linseed oil (ELO) and acetic acid as catalyst has proven a suitable method to impregnate and protect wood. However, the mixture presents a serious inconvenience because of the quick polymerization of the ingredients that limits its practical application. Therefore, this study was designed to evaluate an alternative method using a two-step process which bypassed the problem above.
Fuktomlagringar i välisolerade ytterväggar : En undersökning för att fastställa en rimlig inbyggnadsfuktkvoti träreglar med fuktsimuleringsprogrammet Wufi 2D
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.
Rökgaskondensering och skrubber till vedeldade villapannor :
This paper deals with the opportunities for the technique of condensation, for wood fired household heaters, on the Swedish market. In this project the condenser is preceded by a scrubber and both energy exchange and separation of unburnt particles have been studied.
The facility studied is connected to a wood stove at 30 kW. The tests would show that the effect from the stove never reached above 16 kW. This might be a result of the low temperature of the water going into the stove, from the condenser. In addition to this the wood was not of highest quality and the stove could have needed some maintenance before the tests.
Visuell handelsortering av furu och gran
This essay concerns the visual trade grading of pine and spruce.In the 1800s developed rules for sorting of wood. The rules used to facilitate the export trade.The terms of the regulatory sorting systems developed in the 1900s. While it still used some of the older terms.The essay deals with how the grading rules affect the use of wood and how the rule work and how the terminology works.Some of the terms used for sorting are O/S, Kvinta, Utskott and A,B,C,D.You sorting by counting the numbers of knots, cracks and other characteristics of each piece of wood.The sawmills have much influence in how the rules developed.Today it is often already determined in the sawmills which uses each piece of wood most have..
Habitat preferences and reproductive success forthe threatened longhorn beetle Plagionotusdetritus
Plagionotus detritus is a threatend longhorn beetle that only exists at one site in Sweden. It is saproxylic and depending on recently dead coarse oak wood for its larval development. Trees at Djurgården, Stockholm that have been colonized by Plagionotus detritus has been studied to find out the habitat preferences of the species and to see what affects the density of beetles in a tree. The bark of some trees and wood from the breeding project at Nordens Ark has also been studied to find out what affects the species reproductive success. The reproductive success was measured in two ways, the larval mortality and the size of the hatching holes.
Betydelsen av skogsbruksplaner som verktyg vid anskaffning av virke
Forest management plans have been sold to private forest owners by wood supplying companies for a long time. These plans are considered to be effi-cient tools to identify measures and wood volumes, and are simply a starting point for discussions between private forest owners and round wood pur-chasers. However, large variations are observed between different purchas-ers, in their usage of the plans.
The purpose of this report is to identify to what extent a forest management plan can promote an increase in the amount of wood which a round wood purchaser can obtain and to find differences in the way of using the plans between different wood purchasers. Furthermore, the purpose is also to ana-lyse if varying owner structures can be underlie variations in the selling of forest management plans.
Qualitative interviews with nine of Stora Enso?s round wood purchasers were performed.
Stubbtransporter och bränslekvalitet hos stubbved :
Stump wood is a hot alternative when the heating plants demands more and more forest fuel. The aim with the study has bean to calculate the costs in four different systems for transportations of stump wood, examine if there are any differences in fuel quality for the stump wood in the different systems, analyse if the fuel quality in stump wood is affected with the time it lays by the road side and how much space the stump wood demands on the road side. To calculate the costs for the different systems a system analysis was carried out, where some of the costs were collected through field studies on Holmen Skog stump experiment and other costs were collected from literature and contacts. Data for the fuel quality study was collected from Eons heat plant in Norrköping. Data for the study of how much space stump wood takes along a roadside was collected from field studies.
Social hållbarhet och förtätning : en kritisk studie i förtätningens sociala paradoxer
Densification is one of the urban visions for sustainable development - a vision that has become a part of the solution to the unsustainable sake dilemma. With the dense city land will be saved, energy consumption reduced and social cohesion improved. The dense city is considered to be ecologically, economically and socially sustainable. Applying an urban design concept has thus proven to be problematic. Density has been found to be a complex concept
which is far more complicated than measuring how much built surface that needs to be covered.
It is also not disputed what different degrees of densification mean and whether densification in itself is sustainable.
Logistik för stråbränsle :
Summary
Today energy prices are rising. As a result biomass fuel is getting more and more
interesting. Wood chips is very popular, but also straw from grain production is on the
table. Lunds Energi AB project a combined power and heating plant in Örtofta out of
Lund. Wood chips is meant to be the main energy source, complemented by straw.
In this thesis the transportation of straw for fuel is studied.
Minskad trädtillväxt under Lilla sitiden? : En dendroklimatologisk jämförelse mellan nutid och 1600-talet invid trädgränsen i norra Skandinavien
During the period called Little Ice Age (1400 ~ 1900) the climate of northern Europe was in an annual year-basis overall colder than it was before and after that period. The numbers of short, cold and rainy summers and long, bitter-cold winters where often repetitive under the approximately 500-years the period lasted. In Scandinavia, the coldest time during this period is estimated to have started around the end of the 16th century and lasted to the beginning of the 18th century. Trees growing at the tree-line are limited by temperature for their annual growth and hence showing differences of growth during changes in the climate, a method called dendroclimatology. The variations of growth can be read in the tree-rings either by analyze the width of the ring or by look into the density of the wood and is used to reconstruct past climates.
Jämförelse av fyra rundbalspressars packningsförmåga som funktion av grödans torrsubstanshalt :
To succeed, and make money at your animal production you need to feed your animals with
high quality fodder. Other condition to succeed is that you keep your production costs at a minimum. To be able to produce baled silage at a low cost it?s very important that the bales have a high density. Density is measured in kg dry matter (DM) per cubic meter.
The purpose with this report was to learn more about making silage in round bales and to how much the bale density varies between different brands of round balers.
Sveaskogs möjligheter att utveckla trädbränsleverksamheten i Västerbotten och södra Norrland :
This final thesis is initiated by the wood fuel department at the Swedish forest company Sveaskog as part of a project which also involves two other final thesises. The overall goal of the project is to investigate Sveaskog´s possibilities to produce and sell different wood fuel assortments in Västerbotten and the southern parts of Norrland. The aim of this thesis is to investigate how much wood fuel Sveaskog can produce in the area during the next five years and what that would cost. Furthermore the thesis will investigate the total possible supply of wood fuel from all other possible producers in the area. Treated assortments are forest residues from final fellings, whole trees from direct wood fuel thinnings, non industrial wood and industrial by-products from sawmills.
The main effort to investigate Sveaskog´s production possibilities has been made to calculate the possible annual amount of forest residues and fuel from wood fuel thinnings that can be produced.