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724 Uppsatser om Solid Wood - Sida 13 av 49
Utsikten : Hållbara uppvärmningsalternativ för vandrarhemmet på Finnhamn
Finnhamn is a small group of islands in the Stockholm archipelago. At Stora Jolpan, the biggest island, there is a hostel. The main building was built in 1915 and is called Utsikten. The purpose of this project is to on behalf of the Archipelago Foundation (Skärgårdsstiftelsen) find alternative systems that can replace the existing heating system of Utsikten (an oil-fired boiler and electricity heaters) to a system with renewable energy. The alternative system that this project focuses on is a system of solar collectors combined with a wood chip boiler.
Uttag av energisortiment vid gallring av contorta, ett komplement till konventionell gallring? :
A recommendation for stand treatment of lodgepole pine (Pinus contorta) is, in a scientific point of view, lacking when it comes to harvesting for biomass energy. Within the next decades it is expected that 280 000 hectares of lodgepole pine will have reached thinning age on the domains of Svenska Cellulosa Aktiebolaget (SCA). Due to this the interest has grown rapidly for studying the possibilities of harvesting biofuel assortments already in the first thinning.
In this study the distribution of the biomass within lodgepole pine trees has been studied and taken into account for estimating the proportions of harvested assortments when using different methods of thinning. The methods studied were conventional biofuel-harvesting (with delimbed branches gathered separately from the round wood) and thinning with cutting of round wood and long tops (incl.
Kan biologisk mångfald ökas i ett avsatt skogsområde? : skötselplan för Storskogsberget på Holmen skogs marker, distrikt Umeå
The biodiversity of the Swedish forest has degenerated since the beginning of the 19th century when fire suppression and large scale logging first occurred. Together with a changed land use, these actions today have had a negative influence on many forest dwelling species, due to gradual reduction of natural processes, successions and different structures from the forest ecosystem. The Swedish Forest Act, together with different environment certifications, have today encouraged private persons and forest companies, among them Holmen Skog, to work actively to improve nature conservation. The aim of this study was to, by field inventories of already existing nature values, literature studies, recommendations from scientific reports and ecological gap analysis as a basis, make a management plan, for a non-production area, to conserve or improve the prerequisites for biodiversity. ?Storskogsberget? is located in the coastal area of Västerbotten County, 35 km from the city of Umeå.
Dynamiska egenskaper hos håldäcksbjälklag belastade med gångtrafik
Concrete floors have traditionally had no problems with annoying vibrations. However with the demand for larger spans the floors need to be made more slender with a higher degree of utilization and lower mass. Therefore new floors may have problems with vibration serviceability. This thesis studies the vibration characteristics of hollow core slabs. The analysis was made in the finite element program Ansys. The hollow core slab was subjected to a varying force simulating one person walking across the slab.
SFEH. The clothes. The brand. The style.
SFEHA project about a clothing brand and a new kind of showroom that looses it´s structure during the process.But managed to find the core and produced a personal mirror of prints for a greater cause.Sfeh is the brand with quality and humor in focus and the will to push the boundries. With prints based on free drawing and smart thinking as it´s essential base.The project resulted with a various collection with mostly T-shirts but also textile gloves and bed sheets..
Naturhänsynen i FSC-standarden : vetenskap eller gissningar?
The Swedish FSC standard (Forest Stewardship Council) is a level standard used to certify forestry. All the major Swedish forest companies are using the FSC standard, and approximately 50% of the Swedish forests are FSC certified today. In the essay six items within the chapter on environmental issues and biodiversity are examined: the proportion of protected forest, the proportion of annually burnt clear-cut stands, the number of trees with large diameter, the amount of dead wood, the proportion of deciduous trees within a stand and the proportion of deciduous-dominated stands. The FSC standard states a level for all items, and the purpose of the essay is to analyse whether these levels are supported by research within the field of conservation biology. The validity of the levels of the six items is them discussed to evaluate whether changes are required to the next revision of the FSC standard.
Sortimentsinriktad avverkning
Forest enterprises have always searched for ways to improve efficiency. For the past few
years there has been an emphasis on stock-keeping levels. Increased demand for fresh
round timber and the need to decrease the amount of tied-up capital has made the forest
industry reduce its inventory levels. This has brought on a higher demand on the timber
supply from the forest management districts concerning both delivery in time and
assortment output. As a result, the flow of timber has fluctuated a lot with serious
consequence for the timber supply during 1994.
Förändrad aptering av massaved från 3- till 4-meterslängder vid gallring inom Södra : en systemanalys av effekter från avverkning till levererad virkesråvara
The costs of logging and of transportation with truck are dominating the total cost of wood delivered at industry. To support the profitability for the members' forestry the processing and handling with the timber has to be as efficient as possible. Increased length of pulpwood in thinning is one conduct that can result in higher productivity and/or lower costs. The study is scaled as a system analysis with the aim to exemplify the differences between working with 3- and 4-meter as standard length of pulpwood, related to biological aspects, timber receipts, cost of logging and cost of transportation with truck. Important aspects are if the change is technically and biologically feasible and economically profitable.
Optimering av sintrade kugghjul
Powder Metal (PM) gears are machine element components which operate under the same principle as conventional gears, but, due to their intrinsic material characteristic need to be designed slightly different, and its manufacturing process offers advantages previously unobtainable by conventional steel gear manufacturing methods. The use of PM in similar applications, such as synchronous hubs, makes them a suitable candidate for production in such material. The current master thesis work focuses on gear design using PM by utilizing finite element method (FEM) to reduce weight and inertia taking into account root bending strength and tooth deflection.First a topological optimization is used to determine feasible candidates for different web designs which have as objective to reduce volume, similar topologies were shown during different loading conditions; and hence, this topology was chosen as a suitable candidate. A shape optimization of the topological candidate was performed having as state variables root bending strength, independent for compressive and tensile side of the tooth loading; and tooth deflection, which in concept can be correlated to static transmission error (TE).Another aspect in this thesis analysed is the possibility to incorporate non-trochoid root geometry, a trochoid root is always present when machining with a hob, into the gear root and hence reduce the stress concentration here. Due to the use of PM, a non-symmetric optimized root can be achieved and hence be optimizing compression and tension.Results showed significantly lower inertia, for example certain results showed 40% reduced when compared to solid gear, with adverse effects as increase in tooth deformation and increase in maximum principal stress.
Alternativa finansieringsmöjligheter av företagsfastigheter
It is essential to reuse- and recycles residues to decrease the amount of deposit materials and reach sustainable energy use. Two ways to work towards this is to recycle wood ashes to the forest as nutrient compensation and extract biogas from combustion of biomass.The aim with this study was to decide whether wood ashes that been used for biogas upgrading with accelerated carbonation also can be used as a nutrient compensation in the woods according to recommendations from the Swedish Forest Agency (Skogsstyrelsen).The ashes that were used in this study came from Johan Andersson who works at JTI in Uppsala, who also treated the ashes with biogas. The ashes have, in both untreated and treated condition, been analyzed in this study according to contents of elements, leaching properties, hardening properties and contents of crystalline phases, to evaluate what impact carbonation with biogas has on the ashes.The accelerated carbonation led to hardening of the ash, and decreased amount of CaO- and increased amount of CaCO3. The CO2-uptake also entails a dilution of the elements, and the content of nutrients and trace elements decreases. However the results show an indication of an uptake of S from the biogas to the ash, since the dilution had a smaller impact on S than the rest of the elements.
Variationer av klor, svavel och aska i havrekärna : odlingsfaktorernas inverkan på havrens bränsleegenskaper
The increasing oil prices during the last years have made it profitable to use cereal grains as a fuel. When compared with wood, cereals contain higher amounts of Cl, S and ash. The Cl and S content makes the gases from cereal combustion more corrosive than gases from wood combustion. The goal of this master thesis was to find out the variation of Cl, S and ash content for oat grain grown under different conditions. Oats was chosen because in Sweden it's considered as the cereal with the best fuel qualities.
Energianalys av etanolproduktion : en fallstudie av Lantmännen Agroetanols produktionssystem i Norrköping
In this thesis an energy analysis of ethanol production at the ethanol plant of
Lantmännen Agroetanol in Norrköping has been performed. The ethanol plant has
been studied in combination with Händelöverket, the combined heat and power
plant which provides the ethanol process with steam. The purpose of this study
was to determine the energy consumption for the whole production chain from
grain to ethanol. The analysis has included the energy consumption for cultivation
of grain, production of chemicals, the production chain for wood chips, the steam
production and the ethanol plant. The grain and wood chips are both considered
raw materials there for the energy content in these are not included as energy input
in the system.
Energianalys av etanolproduktion : en fallstudie av Lantmännen Agroetanols produktionssystem i Norrköping
In this thesis an energy analysis of ethanol production at the ethanol plant of
Lantmännen Agroetanol in Norrköping has been performed. The ethanol plant has
been studied in combination with Händelöverket, the combined heat and power
plant which provides the ethanol process with steam. The purpose of this study
was to determine the energy consumption for the whole production chain from
grain to ethanol. The analysis has included the energy consumption for cultivation
of grain, production of chemicals, the production chain for wood chips, the steam
production and the ethanol plant. The grain and wood chips are both considered
raw materials there for the energy content in these are not included as energy input
in the system.
Tillämpning av nya beräkningsmetoder för branddimensionering av träkonstruktioner - analyser och jämförelser
To build high-rise buildings made of timber has for long been limited by national laws, due to the lack of knowledge in engineering solutions. Frame structures made of wood has for a long time been associated with major fire hazards and consequently lower safety and this connection is still being made today. The increased environmental awareness in recent years has contributed to the exploitation of indigenous building materials, including wood from our own Swedish forests and has become increasingly common. Increased knowledge about how structures behave in fire and how they can be protected in order to achieve safe timber structures has resulted in a growing interest in these structures in the construction industry. Research in the area is constantly updated and new laws allow any number of storeys in wooden buildings in Sweden as long as the performance requirements are fulfilled.The main part of this work has involved calculations of the fire resistance and load bearing capacity of floor and wall constructions.
Effektivare energianvändning på Totebo AB
The main goal with this thesis report was to come up with ideas of how to make the use of energy more effective and thus save money for the company.First a survey was made to find out where and how the energy consumers were divided within the company. The results were then used in calculations to find out how much money that could be saved and how long it would take to get back the investments.There is a big potential in saving money by recovering heat from the UV-lamps with a heat exchanger. It would also even out the pressure in the factory which is a source to heat loss and a cause for discomfort amongst the employees. It?s possible to save 105 000 kr in a year and the money needed for the investments is 600 000 kr.By using the recovery air more effectively the company could save up to 250 000 kr a year in lowered heat purchases, but this would require the use of automatic dampers.If you reschedule the running times for the wood chipper and invest in some kind of load management, for example Sydkraft?s ?Energidirigent? you can save at least 42 000 kr.