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699 Uppsatser om Variable air volume - Sida 4 av 47
Tillämpning av kNN-Sverige i Södra Skogs verksamhet : behovsinventering, databearbetning och förberedelse för praktisk implementering
The digital map product kNN-Sweden contains nationwide data of the country?s forest land. The estimated forest variables are mean age, mean tree height, volume per tree species and total volume. Today Södra Skog?s assessments of timber potentials are mainly based on experience rate and subjective assumptions.
Komfortkylsystems installationskostnader och energiförbrukning i kontor
På uppdrag av Creanova AB har detta examensarbete genomförts under hösten 2010. Målet med examensarbetet var att analysera hur installations- och energikostnaderna för komfortkylsystem i standardkontor varierar med olika dimensionerande förutsättningar. Förutsättningarna som har undersökts är framförallt dimensionerande inomhustemperatur, men även solskydd i form av lameller och persienner samt LED-belysning har undersökts. Alla varierade parametrar har simulerats i fyra olika väderstreck både med CAV(Constant Air Volume)-system med konventionell tilluftsbaffel och VAV(Variable air volume)-system med LindInvents aktiva tilluftsdon TTD-160.Beräkningarna för kontoren har simulerats i klimatsimuleringsprogrammet IDA ICE 4.0. Därefter projekterades två olika systemlösningar för kontoret, en med CAV-lösning samt en med VAV-lösning.
En jämförelse av sitkagranens (Picea sitchensis) och den vanliga granens (P. abies) produktion :
Sitka spruce (Picea sitchensis) is a tree species that have its natural distribution along the
West Coast of North America, from Alaska in the north to northern California in the south.
Sitka spruce is a typical coastal tree species that can reach heights up to 85 meters and occurs
in single pure as well as in mixed stands.
The main purposes of this study were to describe the Sitka spruce growing characteristics and
the volume production in comparison to spruce (Picea abies). The possibility to predict future
volume production by using prognosis tools designed to be used on spruce were also studied.
The material that has been used in this study are permanent sitka trials established by the
Faculty of Forestry fixed Sitka trials and also material gathered in this study.
A literature study was also carried out in order to determine the Sitka spruce growing
characteristics.
Sitka spruce has a high adaptation and a high volume production on a broad scale of soil
types. The tree species is a pioneer species that has a fast early growth and in combination
with sharp needles it is less susceptible to animal browsing than spruce. The factor that is the
single most limiting factor for where the Sitka spruce can be planted is frost. This factor can
be limited by using plant material with a well-suited provenance.
According to the literature, the Sitka spruce has an average total volume production that is
between 20-40% higher than spruce.
Höggallring i praktiskt skogsbruk : beskrivning av en gallringsmodell för granskog som tillämpas på Trolleholms Gods
When Norway spruce is planted with large initial spacing and grows on highly productive sites in southern Sweden, a high proportion of the stems gets broad annual rings. The thinning programme carried out at the estate of Trolleholm aims to extract stems with too broad ring width. The 3-4 first thinnings are carried out as thinning from above, where only the thickest trees are removed. The internal distance may not fall below 5-7 meters depending on the number of thinning (short distance in young stands).
The aim of this study was to examine the thinning model that is carried out at the estate of Trolleholm. A volume table is calculated to describe the model, and data is collected on temporary plots.
Skillnader i mulmvolymer mellan fem trädslag i Östergötlands eklandskap
Old hollow trees of oak contain a large amount of wood mould. Unfortunately, these trees have in the last century been greatly reduced in numbers. It has resulted in that species that depend on these habitats, saproxylic species, have become at risk to decrease in numbers or die out regionally. Previous studies have shown that the volume of wood mould is an important factor for occurrence and population size of saproxylic organisms. The aim of the present study was to examine how the volume of wood mould varies among ash (Fraxinus excelsior), lime (Tilia sp.), maple (Acer platanoides), aspen (Populus tremula) and oak (Quercus robur).
Identifiering av konfliktbestånd med hjälp av laserskanning
The interest in harvesting wood fuel in conflict stands has grown in recent years as a consequence of the increased demand for biofuel. Conflict stands are young forests that have not been cleaned and have a large number of stems ha-1with a great height and diameter distribution. This means that traditional field measurements in conflict stands are difficult and very time consuming. Therefore, the forestry sector is in need of new, more efficient inventory methods. In this study, the Lidar data from Lantmäteriet?s (the Swedish mapping, cadastral and land registration authorities) new national height model was used in combination with plots from the Swedish national forest inventory from 2009 to create functions for; height, volume, diameter and number of stems.
Upptryck : En jämförelse mellan RIDAS och internationella riktlinjer
Old hollow trees of oak contain a large amount of wood mould. Unfortunately, these trees have in the last century been greatly reduced in numbers. It has resulted in that species that depend on these habitats, saproxylic species, have become at risk to decrease in numbers or die out regionally. Previous studies have shown that the volume of wood mould is an important factor for occurrence and population size of saproxylic organisms. The aim of the present study was to examine how the volume of wood mould varies among ash (Fraxinus excelsior), lime (Tilia sp.), maple (Acer platanoides), aspen (Populus tremula) and oak (Quercus robur).
Känslighets- och osäkerhetsanalys av parametrar och indata i dagvatten- och recipientmodellen StormTac
Three methods of sensitivity and unceartainty analysis have been applied to the operative stormwater- and recipient model StormTac. The study area is the watershed of lake Flaten in the municipality Salem. StormTac?s submodels for stormwater, pollutant transport and the recipient are cosidired. In the sensitivity assessment, the model parametres and inputs were varied one at a time by a constant percentage according to the ?one at a time? (OAAT) method and the response of the outputs were calculated.
Social musiksmak?: Social påverkan på musiksmak via anonyma räkneverk
The purpose with this paper is to examine whether other peoples opinions of a song and an artist influences an individuals own opinions of the song and artist. Through a quantitative study we seek to study whether such an influence exists and if it does, how strong that influence is. The study began with a pretest to examine whether differences existed when we manipulated our independent variable, how many times the song has been played at Myspace.com. Subsequently we performed a quantitative study by handing out surveys to students at Stockholm School of Economics on two different occasions. Our results show no significant differences in attitude or intentions when the amount of times the song has been played at Myspace.com is manipulated.
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.
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.
Utveckling av 22 : -en motkolvs HCCI motor
Environment friendly transports are one of the main topics in the industry and society today.Shell organizes an annual university competition called Shell Eco Marathon. The goal is to buildthe car that consumes the least fuel during a race. KTH participated for the first time in 2006.The engine for this competition, DoubleTwo, has been developed within the school. Theprinciple is a two stroke counter piston HCCI engine with variable compression ratio. HCCIstands for homogenous charge compression ignition.