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486 Uppsatser om Volume fluctuations - Sida 4 av 33

Evighetsträd

FSC (Forest Stewardship Council) is the major form of certification system in Swedish forestry today and its more than 11 million hectares are covering almost half of the total productive forest area in the country. Its regulations prescribe that at least 10 wind firm trees should be left behind after every clear cutting operation. This study have taken place on 30 recently clearcut objects in Bergslagen, Sweden, were an inventory of the standing stock have been made. The research shows that, with 90 % security, the retained trees together contain 9-13 m3sk per hectare. Pine is the dominant tree and it covers more than half the numbers of retained trees and its volume cover 65 % of the retained trees total volume. Spruce is on second place with 30 % of the retained trees, but only 21 % of the standing stock.

Utredning av behovsstyrd ventilation : En jämförelse mellan CAV och VAV

Denna rapport är ett examensarbete på C-nivå som görs i sammarbete med teknikkonsulten Ramböll. Det vanligaste sättet att ventilera en byggnad idag är med så kallad CAV-ventilation (Constant Air Volume). Denna metod bygger på att ett luftflöde bestäms för rummet och upprätthålls med konstant flöde. En annan metod är så kallad VAV (Variable Air Volume) som bygger på att flödet varierar efter behovet. Anledningen till varför man väljer VAV istället för CAV är att med CAV finns det ofta en stor risk att man överventilerar ett rum eller byggnad, just på grund av att flödet är konstant. Problemet med VAV är att det är en högre investeringskostnad än för CAV så metoden lämpar sig bara där energibesparingen är så stor så den täcker mellanskillnaden i pris.

Död ved i ett referensvattendrag

The purpose with this study is to find out how much dead wood we can expect us to find in a Russian reference river and compare with studies from Swedish streams. Dead wood are an important structure for the biodiversity in forest streams, studies have shown that population of trout can increase with up to 300 % when the amount of dead wood are increasing from 0 to 8 ? 16 LWD (Large woody debris)/100 m2. Dead wood are also an important structure for the stream character, formations of dams and pools which are important habitats and reproduction areas for salmon and brown trout. The study where taken place in tributaries to the Russian river Varzuga in the North West part of Russia outside Murmansk. Varzuga has low impact of human activity and is considered to be a reference river to rivers in northern Sweden.

Potentiella arealer för ökad virkesproduktion i norra Sverige genom skogsodling med Pinus contorta var. latifolia, Larix sukaczewii, Abies lasiocarpa, Populus × wettsteinii och Picea mariana

Sweden is a country with few native tree species. According to Govt. 2007/08: 108, exotic tree species may be seen as an opportunity to increase the growth of tree volume in Sweden. Potential areas where explored In this work for cultivation with Pinus contorta var. latifolia Engelm., Larix sukaczewii Dylis, Abies lasiocarpa (Hook.) Nutt., Populus × wettsteinii Hämet-Ahti (tremula x tremuloides) and Picea mariana (Mill.) Britton et.al.

Deadwood in piles or distributed : does it make any difference to saproxylic beetles?

Piles of deadwood are often retained in forests after management to support the biodiversity ofsaproxylic organisms which depend on deadwood to survive. Any knowledge about the crucial role ofpiles as suitable habitat of saproxylic organisms compared to single distributed deadwood objects thatare around the piles would help conservation actors to motivate more forest owners to supportsaproxylic organisms during their management. Therefore to give facts to this the saproxylic fauna ofdifferent pile positions (up and low) was studied and compared to distributed deadwood samplesaround each pile. Our study was focused on saproxylic beetles. Some other parameters such asdiameter, deadwood volume, pile volume and decay stage were assessed to define any effect.

Planteringsförbandets inverkan på bestånd av contortatall (Pinus contorta var. latifolia) med avseende på volymtillväxt och virkesegenskaper

At the beginning of the 1970´s forestry feared an imbalance in the future wood supply. Because of this anticipated "timber slump" forest companies undertook a variety of measures to counter this. One of these measures was the introduction of exotic tree species. The choice finally ended up with lodgepole pines which were considered a fast growing tree species compared to our native tree species. Theambition for the new lodgepole pine stands were to run these with rotation periods of between 40-60 years, thus smoothing out the ?timber slump? that was anticipated.

Att reducera ledtiden i en produktion med hög variation och låg volym - En casestudie på Lab.gruppen

Due to increasing product availability and higher demands on fast deliveries, the competition between companies is growing. To be able to satisfy the customers? requests an efficient logistics system with short throughput time is required. By using tools associated with Lean production companies are able to make great improvements in their manufacturing systems and reduce lead times to satisfy customer demands.There are two classifications associated with manufacturing, high variety and low volume (HVLV) and low volume and high variety (LVHV). The general belief is that the concept of Lean production is difficult to implement in a production environment with high variety and low volume due to the concept being adapted to mass production.

Studentbostäder i trä med Prefab-teknik

The Results of this thesis was the creation of two designed house variants with a module toall the apartments. In addition till the first module there are three other modules ofapartments that can be put in the houses if it so needs. The house are volume prefabricatedand are placed on site in a way that it create an enclosure of the area which faces against thenature and car parks also lies hidden behind these houses.For the actual structure, a cross beam was created to carry the floor above and it is supportby all four walls. The structure between the first and the second floor has no "syll" butinstead there are two differently alternative to linking the floors in order so that it will notmove. The reason with this solution was that there will not be any subsidence when theforces from above are pressed down ward.

Prognostisering av sortimentsutfall från stående skog med hjälp av befintliga data : anpassat till Sveaskog Norrbottens planeringsprocess

This study in the subject of forest planning is made for Sveaskog and its aim is to develop tools that prognosticate outcome in terms of volumes per sort from not yet cut forest stands. The degree of detail is just to get reliable results for at least one months volumes, for Sveaskogs own forestland in the market region of Norrbotten that is about 100 000 m3fub. The course of action to accomplish this is regression analysis and the data consists of cut tracts on own forestland in Norrbotten during the years 2006, 2007 and 2008. That is a little more than 4 million m3fub. Two tools were made.

Lönsamhetsanalys av tekniker för utökad elproduktion i kraftvärme : Med hänsyn till elprisets variationer

This thesis aims to examine the viability of various techniques for increased electricity generation in CHP plants and the effect of electricity price fluctuations on the profitability.The techniques examined are fuel dryer, pellet production, methane production, combined methane- and pellet production, seasonal heating storages in caverns and pit heat storages and condensing tail. Using Excel and Matlab, the prerequisites for investment costs, revenues and expenses were calculated.What affects the price of electricity is a combination of economic and technological development, energy prices, economic structure, population changes and weather. Different scenarios for the electricity price were therefore examined. In the base case, the electricity price was given by the Nord Pool electricity price statistics of area three in 2011. Thereafter, WiMo was used to design the electricity scenarios for 2030, which was then applied to the data to obtain the viability of various scenarios. The techniques examined were found to give greater profits to the CHP plant by increasing and optimizing the production of electricity.

Jämförelse av två mätmetoder för mindre gasvolym

Two different methods for measuring biogas production were used, gas meter and gasbags. The gas meters were electronic and counted each time a certain gasvolume passed through them. The gasbags collected the gas that hade passed through the gas meter until a manual measuring could be done. The two different methods gave the same result for a volume at three liters but for a volume around 0,2 liters they did not. Accuracy and precision for the gasbags was more exact than for the gas meters even if the method was difficult with a lot of different elements that could affect the result.

Skogstillståndet och dess förändring i naturreservatet Lindbergska ytan i Mariestads kommun :

The aim of the study is to describe the state of the forest and changes in the Lindberg nature reserve. The study area is a nature reserve with an old coniferous forest, which has not been touched since 1950. The pines in the area have a very big diameter and are 150 ? 200 years old. The spruces are up to 150 years old.

Högskolestudenters uppfattning av informationsöverflöd: En studie med fenomenografisk ansats

With the volume and availability of information increasing as fast as technological development in society a phenomenon called information overload has emerged. The purpose of our thesis was to investigate how university students experience this increase in volume and ease in access to information. In our study we concentrated our focus on the student?s use of electronic resources. So as not to prejudice our study group our questions focused on different aspects of searching for information.

Composition of fractions from air-classified wheat flour

The unique ability of wheat to produce leavened bread is mainly due to the gluten proteins present. As consumers are more and more attracted to bread with high fibre content the use of wheat gluten will also increase in order to obtain bread with good volume and appetizing characteristics. Air-classification is a technological method used to separate particles by size and shape by means of air-streams into two fractions, fine and coarse. When used on wheat flour it is known to alter the flour composition in the fractions obtained compared to the original flour. This method is not widely used in the milling industry but could possibly be of interest if protein rich fractions with favorable protein quality can be produced.

Parallell beräkning av omslutande volymer

This paper presents techniques for speeding up commonly used algorithms forbounding volume (BV) computation, such as the AABB, sphere and k-DOP. Byexploiting the possibilities of parallelismin modern processors, the result exceedsthe expected theoretical result. The methods focus on data-level-parallelism(DLP) using Intel?s SSE instructions, for operations on 4 parallel independentsingle precision floating point values, with a theoretical speed-up factor of 4 ondata throughput. Still, a speed-up between 7?9 are shown in the computation ofAABBs and k-DOPs.

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