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993 Uppsatser om Forest fuels - Sida 40 av 67
Utvärdering av produktionsrapporterad volym för contorta
The background to this study is that the forest company, Holmen, has found large discrepancies between harvested volume and the measured volume at the industry. Factors like bark features, breakage, double tops, bends and stem damages was noted, and all stems were measured manually. Hypothesis testing with the method "random in pairs" were used to examine whether the harvester measured values significantly differed from the manually measured.
The result of a properly calibrated harvester shows in average underestimation of the volume with Skogforsk Pine as a bark function. This means that the harvester isn´t the reason why the volume measured in the industry is lower, the fault is elsewhere. The study also indicates a need for a unique bark function for logepole pine..
Inverkan av nederbörd, temperatur och frost på årsringens egenskaper hos boreal tall (Pinus sylvestris L.) :
The wide distribution range of our boreal pine (Pinus sylvestris L.) provides a great variation in growing conditions and climate/weather factors that influence the wood development of the trees. A great number of extensive studies have been conducted over the years in order to clarify growth trends of this and other species over more or less wide-ranging areas.
In this thesis effects of weather factors were instead compared between different forest stands from the about same geographical location. The effects of precipitation, temperature and frost on the year ring characteristics of pine were studied in the research forest of Svartberget Vindeln, in northern Sweden. The stands differed in site index and silvicultural treatment; fertile ? high stem density, fertile ? low stem density, poor ? high stem density and poor ? low stem density.
Digitala kommunikationer mellan VIDA och deras leverantörer
The Swedish forest industry has put a lot of resources in the development of digital communications in hopes of improving collaboration with suppliers. The purpose of this study was to investigate whether VIDA would benefit from using digital communication with suppliers.
The survey was conducted as a questionnaire study among the company?s staff and its suppliers. The result indicated needs and interests to use digital communications in both groups. Young suppliers and suppliers on a distance showed the most interest in using digital communication.
In terms of using these digital communications, the staffs and suppliers were most interested in information regarding transaction and forestmanagement plans.
Merkostnader med vinterväghållning för Grot-transporter orsakade av väglagring.
Fuel wood is currently the third largest assortment from the forest in Sweden after pulpwood and lumber. Branches and tops i.e. logging residues are one of the assortments of fuel wood which is a common by-product after harvesting nowadays. The way to utilize, disintegrate and transport the logging residues varies between northern and southern Sweden. Branches and tops are collected throughout the year at appropriate stands, but are consumed mainly wintertime.
Kraft och Deformationsmätningar på Snap Load gummi
The power consumption has grown rapidlyin the last decade. Fossil fuels and theneed for alternative energy sources aregreat. Ocean waves are a renewable andsustainable source of energy that hasbeen relatively untapped. At UppsalaUniversity research and development havebeen done for several years. Severaltypes of wave energy converters (WEC)have been created.
Undersökning av självspridning av contortatallen i norra Sverige
Over the past 40 years 600 000 ha of lodgepole pine (Pinus contorta ssp. latifolia (Engelm.) Critchf.) has been planted in Sweden (280 000 ha on SCA's forest land alone which represents about 15% of the company's total forest land area). In the early 70's SCA situated a number of experimental stands in order to investigate different aspects of the exotic tree, primarily growth rate. To be able to compare the two species plots with scots pine (Pinus sylvestris L.), this species was also planted at the same time and under the same conditions.
A number of questions should always be raised when exotic species are introduced in an ecosystem. Invasiveness, the pathogen situation and purely ethical issues should be discussed.
GIS-modellering av habitat för vitryggig hackspett (Dendrocopos leucotos) som hjälpmedel i naturvårdsplanering på landskapsnivå :
The white-backed woodpecker is a forest bird being critically endangered in Sweden. The species is dependent on older forests rich in deciduous trees and dead wood. The main problem for the survival of this species is present shortage of habitat. Conservation work on this umbrella species is at present focused on finding remaining or emerging habitat networks. Large areas are scrutinized in search for suitable habitats to be protected or managed for the species sake.
Kärnkraftens värde i framtiden : en jämförelse med kraftvärmeteknologi från biobränsle
The debate on the future of Nuclear power in Sweden has increased with the discussion on global warming. The uncertainty of fossil fuel- and carbonprices the latest years has aroused considerable interest in Nuclear from power companies, industry and politicians. Nuclear power plants have negligible CO2 emissions and are not directly affected by increased price of emission rights and fossil fuels. The future power production needs to reduce its emissions of greenhouse gases to become sustainable.
The purpose of this study is to examine the value for power producers to have the option to invest in Nuclear power and how a Nuclear power venture would affect future electricity prices. The study uses two methods, a traditional cash flow model and real option analysis, to estimate the value of Nuclear power.
Skottbetning på granplantor i Kolmården : omfattning och påverkande faktorer
In the Kolmården area, northeast of Norrköping in south-central Sweden, it was discovered that shoots of spruce Picea abies, plants to a seemingly large extent had been browsed by deer. The area inhabits a dense red deer population, alongside with moose and roe deer, and red deer is thus suspected to cause the damage. The main purposes of this study are, however, to estimate the extent of the shoot-damage and to investigate what factors that may affect the browsing of shoots.
For each stand information was recorded about the age of the plants, area for the stand, height over the sea for the stand, site productivity, type of plants and stand-history.
The study was done in three areas: Simonstorp, Stavsjö and Valinge. At Simonstorp and Stavsjö, respectively, 10 stands were chosen for study and on Valinge six stands. In each stand, 10 plots were sampled.
Enkätundersökning hos markägare inom SCA Skog Jämtlands förvaltning
This report is a joint venture with SCA Skog AB in the Jämtland forest management area. The company is a major player in the timber market in northern Sweden, and also a large business globally with offices in over 100 countries. The purpose of the study was to find out how timber suppliers want feedback/follow-up after completion of timber business. To determine this, a questionnaire survey was sent out to 75 landowners who supplied the wood for the company during the past year. The questionnaire consisted of a total of 15 questions with the opportunity to comment on certain issues.
Biogas på Wapnö : Analys av framtida energisystem
Considering that the price and demand for energy gradually has risen over the past decade and a wider discussion about the human impact on the environment has become increasingly more important and given a clearer role in modern society. This has contributed to increased incentives to reduce the use of fossil fuels and increase the use of renewable energy.The agriculture currently accounts for 20 % of Sweden's total greenhouse gas emissions. A way for an agricultural company like Wapnö AB to reduce their emissions could be to utilize existing renewable energy sources within their own premises.The report's aim is to create an energy audit of Wapnö?s existing energy system and how it changes with a future biogas plant in operation. The energy audit is used to illustrate how the company?s climate footprint could change.
Förutsättningarna för ett parallellt generation IV system vid svensk nybyggnation av kärnkraft.
A new build in the Swedish nuclear power system would entail increased re-quirements for the proposed repository, which is adapted after the reactors of today. With a fast reactor, capable of burning nuclear waste, operating in parallel with the light water reactors, the increased requirements on the repository could be reduced.In this thesis, simulations of a light water reactor and a fast reactor have been performed by using the Monte Carlo code Serpent to investigate the changes in the fuel inventory. The light water reactor in the study is a boiling water reactor and the fast reactor of the type sodium-cooled fast reactor and they have been used for three different operation scenarios.By studying the fuel composition and the results from the simulations of the three scenarios conclusions can be drawn. Conclusions regarding the change of the fuel inventory and decay heat in Clab as well as the interim storage facility and in the repository. Depending on the operation alternative the changes dif-fered significantly and especially regarding the mass of burned actinides for different fuels in the fast reactor.The lowest increase of fuel assemblies was meet when using 50 years old fuel with 20MWd/kg U burnout and 2,0 % enrichment for start up of the fast reactor and 30 years old fuel assemblies with 50MWd/kg U burnout and 4,7 % enrichment for the further operation of the reactor.The increase of the number of fuel assemblies was 3174, which is equivalent to 641tons of heavy metal.
Energi - och ekonomipotential för solceller i Hållbara Järva
One of the city of Stockholm?s main objectives is to have a society completely free from fossil fuels. To achieve this, several investments regarding improvements in energy efficiency and renewable energy are currently being planned or implemented. One of these investments is a project called Hallbara Jarva which is located in the suburbs of Stockholm. The purpose of this thesis is to examine the prospects of an investment in photovoltaic cells from an energy-saving and economical point of view. The analysis is limited to three buildings within Hallbara Jarva and is intended for the property owner. Solar energy is a type of renewable energy source and is commonly divided into solar heating and solar power.
Uppgradering av biogas med aska från trädbränslen
The Swedish production of biogas was 1,5 TWh 2011. About half of the production was used as vehicle fuels. The cost for upgrading biogas depends on the size of the biogas plant and its gas production. If the gas flow is low the cost will be high. However, further development of existing upgrading technologies or development of new ones, have good potential to decrease the upgrading cost for small scale biogas plants.
Naturreservat : en bra naturvårdsåtgärd för att bevara enskilda arter och/eller bevara den biologiska mångfalden?
The examination of the adequate nature conservation methods in a natural reserve, to conserve a specific species and / or increase biological diversity is the subject of this study. This work is based on four species, that can be found during the Spring season, liverleaf, wood anemone, brimstone and woodpecker. The incidence and availability is studied and closely observed for these species in twenty forests, i.e. ten forests which are nature reserves and ten forests with the similar characteristics as the nature reserves habitat, but are not nature reserves in Gnesta mucipality, Södermanland. Measurements of the tree crown and the diameter of the tree trunks where noted to study how these factors could affect the outcome of the abundance and incidence of the four species.