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2171 Uppsatser om Springback and density of the compressed wood. In addition - Sida 12 av 145
Passivhus av helväggselement i träull
Environmental destruction is a growing problem in our world. Almost every day there are new reports concerning that we have to do something about the greenhouse gasses. Simultaneously is the human constantly more eager to have a life with higher standards and therefore uses more energy. The environment is a question that is highly up-to-date and more people try to find solutions on how to save our planet. One way to decrease the energy demand is to build passive houses, where the houses don?t have any active heating.
Epixylic, forest-interior bryophytes in young stands : importance of local environmental variables, propagule sources, and distance to bordering woodland key habitats
The reduction of coarse, dead wood is considered to be the biggest threat to flora and faunain boreal forests. Extensive harvest of logging residues would increase this reduction evenmore. However, the role of dead wood created at final felling for boreal, epixylic species isstill largely unclear. It is therefore of interest to examine whether epixylic species inhabit thedead wood in young, boreal stands, especially species considered to be confined to forests inlate successional stages.The aim of this study was to investigate whether forest-interior species in fact can inhabitearly-successional forests arisen after logging. The study was conducted in young standsbordering dead wood rich woodland key habitats.
Traditionell skidtillverkning: ett kunskapskomplement till dokument?ren Skidmakaren i Gielas
Archaeological findings show that ski manufacturing goes back thousands of years in the Nordic region. There is a wealth of literature and film that deals with the subject, but it can be difficult to get an overall picture of how a specific type of traditional ski has been made. The starting point is the documentary "Skidmakaren i Gielas", where the viewer can follow Alfred Israelsson as he makes a pair of skis out of birch wood. However, the documentary lacks important information about how the skis are actually manufactured. Length, width and certain working steps are disclosed.
Skogsentreprenad idag och i framtiden : en kvalitativ studie av skogsmaskinentreprenörersverksamhet och framtidsvisioner
The Department of Forest Products and Management, Swedish University of Agricultural Sciences has received means from Vinnova for a preliminary study of the organisation of logging work of today and how a better logging organisation should be brought about. This thesis reports results from qualitative interviews with nine forest machine contractors regarding the situation of their companies. The interviews have been analysed with respect to the genesis of the companies, which tasks they perform or that they could consider perform-ing, business relationships of the companies, relationships between the different partners of the companies, and the state of competition experienced by the contractors. The companies have developed either from the contractor previously being machine operator employee or from that the contractor in making has owned a machine and needed work. Their primary business is mechanised logging.
Kartläggning av Sveriges landstings användning av telemedicin
Sweden's aging population makes the need for a viable health care urgent and telemedicine can be a solution to enable older people to receive or give themselves care in their homes. Furthermore, implementation of telemedicine has the potential to realise profits in society by increasing the accessibility of health care and minimizing travel costs. Sweden?s low population density and geographical configuration makes the advantages of telemedicine even more appealing. To illustrate the differences between the county councils? use of telemedicine and thus increasing the possibility for coordinated care between them, the authors have on behalf of the Innovation Centre at the Karolinska University hospital mapped the amount of telemedicine technologies that are available in the Swedish county councils? today. To collect information an electronic survey and video or telephone interviews were used.
Val av stommaterial : Vilket är det mest fördelaktiga stommaterialet vid uppförande av en hallbyggnad?
When constructing an industrial- or hall building, the most common framework materials thatis used are wood, steel or concrete. Due to an assignment from Byggnadstekniska Byrån ABhas a document been created that makes it possible to investigate how the final costs is af-fected by gapes in between elements and which used foundation. And this with steel as thematerial. The purpose with this essay is to investigate which is the most well fitted materialwhen constructing an industrial- or hall building wood, steel or concrete. Information aboutthe different materials has been collected by litterateurs and by different internet pages.
Skötselns och ståndortens betydelse för kärnvedsbildningen i tall
Heartwood has always been a desirable part of the tree, due to it?s superior decay qualities com-pared to the sapwood. How the formation of heartwood works has been known for a long time, but which factors that initiates and stimulates the production are poorly understood. This case study presents the results of a study in which silvicultural treatments and site properties had a key position as factors to the formation of heartwood. According to the hypothesis the amount of sapwood is directly controlled by the size of the crown.
Analys och förbättring av en mätenhet för laddning av elfordon
Reducing the CO2-pollution, resulting from the combustion of fossil coal for energyproduction, is important to affect environmental changes. One way to achieve a reductionis to use the oxy-fuel technology. The technology uses O2 and re-circulated flue gasduring the combustion which results in a flue gas mainly consisting of CO2. The flue gascould then be compressed and stored without environmental effects. A problem thatfollows from the compression is the risk of acidification in sensitive parts of the process.Acidification can occur because of reactions following from the contact of condensedwater and sulphur- and nitrogen-oxides which are also present in the flue gas.This report compiles and evaluates the basis of a scientific unit with the purpose ofexploring the possibilities of extracting impurities of SOx and NOx from the flue gases.The dimensions of the unit are based on basic conditions, defined for an existing oxy-fuelprocess at Chalmers, and on the results of computer modelling.
Föroreningar orsakade av stenar inblandade i barrmassaved
Holmen Skog AB is an important supplier of conifer pulpwood to the Iggesund Paperboard mill. After logging and transport to the landing by a forwarder, the wood is loaded on trucks for further transport, often by using separate loaders. During this handling process considerable amounts of stone material is sometimes mixed into the pulpwood and this causes problems for the industry. The aim of this study is to identify which part of the chain from forest to pulpmill, that contributes the most to this contamination. Sizes and total volumes of the contaminating stones were also investigated.
Jordbrukets påverkan på Östersjön : en jämförelse av indikatorer för att beskriva näringsbelastningen
The Baltic Sea, due to its special conditions, is a unique and vulnerable marine environment. There are many pressures that have an impact on the sea and one of the major problems is the extensive flow of nutrients from land. The most visible effect of the supply of nutrients is the annual algal blooms.
One of the main sources of nitrogen and phosphorus supply is agriculture. Nutrient losses
from arable land have been increasing as agricultural production has intensified. At the end of the twentieth century an increased awareness of these problems led to the formation of organizations such as HELCOM and Baltic 21.
Hallsta Pappersbruks virkesförsörjning
Competition of spruce fiber raw materials has increased dramatically in the last few years, leading to the fact that transportation costs in the current situation represents a much larger share of the total raw material cost. The Holmen-owned pulp industry Hallsta Paper Mill's location on the coast also constitutes a problem, because of the lack of raw material, which is much larger there, than for a pulp mill located in the hinterland. For a coastal industry it?s therefore natural to import much of the raw material by boat or to buy it from the timber terminals, in order to maintain good profitability. The purpose of this study was to analyze how the size of Hallsta Paper Mill timber supply area, without competition, with competition and with terminal use, affects the company ?s transport costs.
Design av försöksanläggning för trycksatt rökgasrening vid oxy-fuelförbränning
Reducing the CO2-pollution, resulting from the combustion of fossil coal for energyproduction, is important to affect environmental changes. One way to achieve a reductionis to use the oxy-fuel technology. The technology uses O2 and re-circulated flue gasduring the combustion which results in a flue gas mainly consisting of CO2. The flue gascould then be compressed and stored without environmental effects. A problem thatfollows from the compression is the risk of acidification in sensitive parts of the process.Acidification can occur because of reactions following from the contact of condensedwater and sulphur- and nitrogen-oxides which are also present in the flue gas.This report compiles and evaluates the basis of a scientific unit with the purpose ofexploring the possibilities of extracting impurities of SOx and NOx from the flue gases.The dimensions of the unit are based on basic conditions, defined for an existing oxy-fuelprocess at Chalmers, and on the results of computer modelling.
Större svartbagge Upis ceramboides i norra Hälsingland : förekomst, substratkrav och effekter av skogsbrukets naturvårdsåtgärder
Many wood living insects are considered threatened by modern forestry due to the reduction in amount of dead wood. During the last decade various methods have been used to enhance the quantity of dead wood in managed forests. However little is known how and if these methods are aiding saproxylic insects. The threatened tenebrionid beetle, Upis ceramboides, is already extinct in southern Sweden. It develops in white rotted dead birch (Betula spp) and requires sun-exposed sites.
Uppvärmning av mjölkgård med ved, flis eller havre :
The background for my thesis is the fact that with rising electricity and oil prices it becomes interesting to calculate on alternative heating systems. I have chosen to calculate upon my parents? farm, which today heats the dwelling house with wood. This is very time-consuming work, time which could be spent on other work.
The main objective for this study is to compare three different heating systems to decide how they differ considering effort and cost.
The result from the calculations was that grain-heating system demanded the least amount of work, but the total cost was a little higher compared to chips heating. Chips heating required half as much work as today?s wood heating and had a little lower total costs compared with the corn heating.
Which system to choose largely depends on how the own work is valued.
Vätedriven förbränningsmotor : Klarläggande av framtida hållbarhet
Today when new and harder demands on CO2 emissions are developed, vehicle manufacturers must work to develop new engine solutions to new kinds of fuels to replace fossil fuels. A fuel that could be applied is hydrogen. When hydrogen is combusted only water vapor occurs. Hydrogen is known to be explosive and flammable. These properties are both good and bad for combustion.