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696 Uppsatser om Wood density - Sida 2 av 47

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.

Qualities and supply of suitable dead wood for Ceruchus chrysomelinus and its dispersal pattern in a translocated population

The wood-living beetle Ceruchus chrysomelinus is a rare species connected to natural forests. In Sweden, it is red-listed as endangered (EN) and an action plan for its preservation has been done by the Swedish Environmental Protection Agency. In this work I have therefore investigated how a translocation of the species succeeded after 17 years. I aimed to study the species dispersal biology, its substrate preferences and the supply of suitable wood on this site. The study was performed during 2012 in Pansaruddens nature reserve close to Uppsala in Sweden, which is a spruce dominated forest.

Hör träbränslena hemma i växthusen? :

With the elevated oil prices of today it is necessary to look for other heating alternatives. If the oil price continues to develop in the same way it has done the last years it will soon be impossible for many producing garden companies to survive. The purpose of this diploma work is to compare three different fuel options in order to find the most economic one considering the conditions of Katrinebergs Handelsträdgård AB. In relation to oil it is profitable to change to any of the three alternatives: wood chips, wood pellets and grain. The most profitable option is to change to wood chips. This alternative has a payoff time less than three years and after that the annual saving compared to the oil is relatively high. The annual cost is 65 % of the cost of the oil alternative.

Död ved i vatten - funktionella strukturer och dess påverkan på öring (Salmo trutta, L.)

The background to this work was to see if there was a connection between large woody debris (LWD) and the presence of brown trout in our Swedish forest streams. Previous researches by Degerman et al. (2004) have shown that there is a strong correlation between the amount of dead wood and the presence of brown trout. The goal was then to find a way to restore, maintain and increase the trout habitats by constructing and adding manmade wooden structures that would mimic natural deadwood and its features in flowing water. The inspiration was partially taken from a water restoration program in the Klamath River of northern California, USA.

Produktivitet och lönsamhet vid skörd av skogsbränsle i klen björkgallring :

The aim of the study was to compare productivity in first thinning of birch stands, when either energy- or pulpwood was harvested. The systems total profitability was also compared by including forwarding and chipping costs. A Gremo 950 HPVR harvester was used and the same driver was used under the entire study. During the pulpwood harvest a Logmax 4000b harvester head was used and a feller buncher head made by Silvatec was used during the energy wood harvest. Six study unit pairs were located in a birch dominated stand outside Ängelholm in Skåne.

Uppfattningar om tryckved bland träbearbetande företag i Sverige :

The primary purpose of this study has been to investigate the Swedish timber industry?s perception of compression wood. A secondary aim has been to describe particular areas within the production process where compression wood is likely to cause problems. This study has mainly been carried out as a questionnaire. In order to connect the findings to current research, additional information has also been collected by means of a literature review. The questionnaire has been intended for sawmills and wood-manufacturing companies from various production classes and owner categories, as well as from different parts of the country.

Export of wood pellets from British Columbia : a study about the production environment and international competitiveness of wood pellets from British Columbia

The global wood pellet market has seen a rapid growth after the adoption of the Kyoto protocol and the renewable energy incentives created within the European Union. The global consumption of wood pellets reached 13,5 million tonnes in 2010 and several experts estimate the consumption to be between 35-50 million tonnes by 2020. These forescasts raise the questions which regions that can supply this vast amount of wood pellets and what the conditions are for producing it. This study evaluates the conditions for wood pellet production and export from British Columbia, on Canada?s west coast, focusing on existing industry structure, raw material supply and the distribution chain.

Röjningsförbandets betydelse för avverkningsekonomin i södra Sverige :

The aim of this work is to demonstrate how the net present value (NPV) at the time of the first thinning depends on the spacing after pre-commercial thinning, and show how net value from first thinning in same stand is influenced. This study is performed with models based on non-distant dependent growth models for single trees. Two different growth models have been used, one for cleaning (pre-commercial thinning) and one for thinning. The first one yields stem density distributed over diameter classes. In the second one, (the thinning model), it is possible to choose when thinning should be done, the thinning method, thinning grade and numbers of thinning.

Död ved i gallrad skog och nyckelbiotoper : en jämförelse av habitatkvaliteter för vedlevande lavar och mossor

A high amount of dead wood is one of the most important prerequisites for high biodiversity on forest land in Sweden. Dead wood is most abundant in young forests, thinned forests, woodland key habitats and protected forest land. In old-growth forests most of the dead wood consists of logs and snags, whilst in managed forests a huge proportion of dead wood is made up of logging residues like stumps and FWD, fine woody debris (< 10 cm diameter). All these different types of dead wood may serve as substrates for epixylic bryophytes and lichens. However, few studies have been conducted on the relative importance of these different fractions of dead wood for the occurrence of bryophytes and lichens, especially when considering dead wood on thinned forest land.

Automatisk tändning till modern vedpanna

If you have access to wood, a wood burning boiler is a cheap way to heat your home, but it is certainly not the most convenient option. Wood requires many operations and management, which takes time. One way to reduce this workload is to have a modern boiler with automatic ignition. Enertech/CTC has a desire to create an accessory with automatic ignition to a modern wood burning boiler. Today there is no boiler on the market that can ignite firewood automatically without the introduction of paper and sticks.

Efterfrågan av grova sågade dimensioner och hyvlade produkter bland Wallnäs AB:s kunder : en marknadsundersökning

The purpose of this thesis is to study whether there is a demand for sawn wood products of large dimensions and planed goods among Wallnäs AB:s customers. The thesis consist of two main parts, one survey among Wallnäs present customers and another one which purpose is to increase Wallnäs customer base. Finally there is a chapter that describes what properties the raw material has to have in order to produce the demanded products. The survey to the present customers was conducted through a questioner. A sample of those who stated an interest for either sawn wood products of large dimensions or planed goods, were later contacted for a telephone interview. To reach out to new customers, relevant companies has been identified through the Swedish Trade Councils data base and through the member list of the Timber Trade Federation.

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