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677 Uppsatser om Bark fissure depth - Sida 2 av 46

P?m?rkning vid virkesberedning - Bastning. Ett hantverksf?rs?k

This essay aims to investigate a rare method of marking up timber before hewing it. The method for marking up timber is by eyesight, where visual judgment and the use of a broad axe are the tools employed. The broad axe is driven through the bark and exposes the inner bark in a straight line. The method is described by a craftsperson dating back to the 1930s. There is a lack of information regarding the method.

Habitatpreferenser hos tjockskalig målarmussla (Unio crassus) med avseende på vattendjup och beskuggning.

The thick-shelled river mussel (Unio crassus) is a red listed species classified as Endangered (EN) and is also considered within the Habitats Directive. The distribution in Sweden is fragmented and it is mostly occurring in the south eastern parts. We investigated the presence of Unio crassus in a section of the stream Storån, Östergötland County, from Falerum to the inflow into Lake Åkervristen. The environmental parameters investigated were water depth, bottom substrate, shading, water velocity and the slope over the water surface. In this thesis I have focused mainly on water depth and shading, comparing sites with and without mussels.

Allt är möjligt hus i Gustavsberg

In a sequence described in the next paragraphs, I remove the poorly insulated roof of Gustavsberg Porcelain Factory and make new use of its  foundation. The monolith cement slab, once supporting heavy industrial machinery, is now the site of lakes and other movements:The top floor area is split, and a new built volume, one story higher, overtakes the southern half resting on the factory?s basement, digging into it at its western and eastern ends. Striking horizontally, the fissure exposes a long central axis, taking advantage of the factory?s horizontality to articulate vastness .

Kol-14 datering : En litteraturstudie över hur kol-14 isotopen används för datering, samt utveckling och tillämpning av djup-åldersmodeller inom naturgeografin.

This literature study concerned the use and function of the radioactive isotope carbon-14, as a dating method of organic material, within the scientific field of physical geography. In this report it is presented the need of atmospheric calibration curves and the development of these as a necessity to translate carbon-14 years to calibrated calendar years. A number of common age-depth models that is used to give an approximation of an accumulation sequence and its related dates over the actual time period in different natural archives is presented and discussed. Different problems that commonly occur when age-depth models are utilized as for instance reservoir effects, contaminations or other age deviations are addressed and analyzed. The software CLAM in presented and discussed and was also used to produce age-depth models.

Biomass losses during short-term storage of bark and recovered wood

Storage of biomass is associated with problems like heat development, biomasslosses, and reduction of the fuel quality. Certain processes such as biological- andchemical degradation are responsible for these storage problems. This master?sthesis was carried out at Vattenfall Research and Development AB and is alignedtowards quantifying the biomass losses from short-term storage (1-2 months) ofbark and recovered wood. The biomass was stored in outdoor piles during differentseasons, campaign 1 (summer) and campaign 2 (autumn).

Vilken är den teoretiskt optimala toppdiametern på bokmassaved vid motormanuell avverkning?

The bioenergy market has been introduced relatively late in a perspective of the Swedish forestry. Nowadays branches and tops are used more frequently as bioenergy after harvesting. Therefore, it has developed a competitive situation between pulpwood and bioenergy. This situation has even established some questions. Two examples of these are: ? At what top diameter should the final piece of pulpwood be crosscut to get the best economically result? ? Should the top diameter, at the final piece of pulpwood, be crosscut at a thicker or smaller diameter than what is done today? The purpose of this report is to answer these two questions when the harvesting is made motor manually in beech stands.

Effekt av sönderdelningsgrad och planteringsdjup på uppkomsten från rhizom av Tussilago farfara :

Tussilago farfara, coltsfoot, is a troublesome perennial weed with deep lying rhizome, which can vegetatively generate new plants. The mechanical control of coltsfoot that is used today, "starvation", which consists of several cultivations of the soil, which fragmentises the rhizome. This results in production of new shoots, which leads to depletion of nutrient resources; as long the new plant is not allowed to establish. However, very little research has been done to investigate how the starving technique affects the regenerative ability of coltsfoot. The purpose of this experiment with coltsfoot was to investigate how fragmentation and burial depths affect the time of emergence, number of emerged shoots per rhizome fragment, number of shoots per node, and if the germination ability within nodes changes during the experiment.

Utredning av barkhanteringen vid Billerud Karlsborg AB

Uppgiften bestod av att göra en undersökning av barkhanteringen vid Billerud Karlsborg AB med avseende på ekonomi och barkens torrhalt. Undersökningen omfattar allt från stock till förbränning och eventuell försäljning av barken. Tidigare så förbrukades all bark i barkpannan, där ånga produceras för torkning av pappret och elproduktion i ångturbinen. I dag har stora delar av pappersbruket byggts om och effektiviseras, vilket medfört att bruket producerar mer ånga än vad som behövs och vad turbinen klarar av att förbruka. Den bark som inte förbrukas av Billerud försöker man sälja och barken som blir över lagras i en stor barkstack.

Bättre åtkomst till avverkningstrakter med anpassat marktryck från avverkningsmaskinerna

The global climate-change means increasing mean-temperature and higher precipitation in Sweden, which leads to shorter periods of frozen ground in the forest. At the same time the harvesting machines are getting bigger and more powerful. The forest industry aim at an even wood flow, and the ground damage has to be as low as possible. The two biggest causes for ground-damage is the bearing capacity of the forest ground and the ground-pressure of the harvesting machines. The aim of this study was to find out some rules for the machine choice considering ground pressure, when harvesting on ground with low bearing capacity.A field study, using a Valmet 890.3 forwarder, was carried out where different ground pressures and their effect on the ground were tested on two different types of ground.Additionally, an inventory of damaged harvesting grounds was made.

CFD-simulering av kallras från fönster : Konvektorers och nischdjupets inverkan på lufthastigheter i rummet

During cold winter days it is likely that people in buildings with older windows or high glass facades experience thermal discomfort due to cold air down draughts. Earlier work has been aimed at finding analytical methods to predict the speed of the airflow in a room and in practice heating appliances are often placed beneath the windows to reduce the draught along the floor. In a study from 2012 Mohammad Parchami developed a method for estimating the required heating power to counteract the downdraught with such heating appliances. In this study, Computational Fluid Dynamics (CFD) was used to evaluate the usefulness of Parchami?s method and also to examine the potential of adapting the depth of the inward window sill as a means of decreasing the down draught.

Armeringsmatta och bark som markstabiliserande material på betesytor till mjölkkor - en utvärdering

Ett vanligt problem på mjölkgårdar är att trampskador uppkommer på betesytor som är kraftigt belastade av mjölkkor under betessäsongen. Den genomsnittliga besättningsstorleken i Sverige stiger och det leder till att problemet med trampskador ökar. Risken för trampskador tilltar vid stora mängder nederbörd. För att undvika trampskador på marken går det att dränera och ta bort matjorden och lägga dit ett markstabiliserande material. Bark som markstabiliserande material har i tidigare studier visat sig vara bra om barken är ordentligt packad.

Ekoturism i Sverige : Avsaknaden av "eko" i Ekoturism?

The purpose of this work is to examine how ecotourism exists in Sweden. In order to answer this, the essay has been based on a qualitative method, which means that the authors have mainly used depth interviews for information gathering. Some of the empirical work is also done using the qualitative method, by gathering statistics, figures and scientific articles. The essay is divided into various chapters to give the essay a clear structure and for the convenience of the reader. The part that have been of most use and support for authors is the depth interviews with the interviewees.

Productivity of integrated harvesting of pulpwood and energy wood in first commercial thinnings

The aim of this study was to quantify the productivity and the costs of different harvesting systems (teams), containing harvesters equipped with accumulating harvester heads and forwarders, in first commercial thinnings were an integrated harvest of pulpwood and energy wood were performed. In the beginning the plan was to study and measure 20 sites before and after harvest. Due to storms during the summer of 2010, complete data could only be obtained from 8 of these 20 sites. Seven of these sites were privately owned and one was owned by UPM, all of the sites had been pre-commercially thinned. The mean stem density before harvest was 2578 stems per ha and the mean stem volume was 0.074 m3solid over bark.On average 1518 stems/ha was harvested.

Bark och armeringsmatta för att förebygga trampskador på betesytor hårt belastade av mjölkkor : en utvärdering

Ett vanligt problem på mjölkgårdar är att drivningsgator, grindhål, ytor kring vattentråg och andra högt belastade ytor blir söndertrampade under betessäsongen. Detta kan bidra till problem som sänkt djurhälsa, försämrad mjölkkvalité och dåligt fungerande kotrafik. De söndertrampade ytorna är även känsligare för jorderosion och näringsläckage. För att undvika denna typ av problem kan markstabiliserande material anläggas på dessa ytor. Detta examensarbete är en del av projektet Kamp mot tramp, ett projekt finansierat av Stiftelsen Lantbruksforskning.

Elementkoncentrationer i gran utmed en markfuktighetsgradient :

One key factor in silviculture today is sustainability. In order to achieve sustainability it may be important to restore lost nutrients to the forest after clearcutting. In order to calculate the removal, you need to know how much of different elements you will find in different tree compartments. The aim of this study was to investigate if the concentration of elements in different tree compartments of spruce (Picea abies (L.) Karst) were related to the moisture conditions of the site. Five plots at Risfallet (60º 21´ N, 16º 13´ E), was placed along a moisture gradient in a 40- year spruce stand.

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