Sökresultat:
474 Uppsatser om Hubs in wood - Sida 12 av 32
Dimensionering av industrilager för biobränsle :
The aim of this study was to develop a simple model for calculating stock costs for bio fuel at Billerud Karlsborg and subsequently recommending a suitable stock level of bio fuel. The stock components considered in the model are GROT (branches and tops), bark, dry wood chips, raw wood chips from barking and sawdust. The calculations are based on a probability distribution of historical deviations between ordered and delivered volumes. The model presents two different ways to manage the supply in case of irregular deliveries. The first way is to stock enough volume to cover the deviations and the second way is to compensate with a quick purchase from the spot market (at extra high purchase prices).
Analys av framtida potential för virkesköp från privata skogsägare i Västerbottens län : beslutsunderlag för virkesköpsstrategier
This study was conducted on behalf of SCA forest AB, Västerbottens forest administration. Timber procurement from non-industrial private forest owners has become an increasingly important part of SCA:s wood supply. The objectives of this study was to report the current forest conditions in the private forests in the county of Västerbotten, analyse the potential for procurement of wood from private forest owners, and provide a basis for decisions on future strategies for timber procurement from private owners.Material and data have been collected from different sources, mainly from Swedish National Forest Inventory and SKA-VB08. This material was the basis for the analysis and calculations performed with the Heureka application PlanWise. This study area was divided into six different analytical areas (Coastal south, Coastal middle, Lycksele, Inland south, Inland north, Skellefteå), where each area of analysis is represented by a number of municipalities.In this study, two scenarios were specified; one describing the current forest management with current harvesting levels and the effects of these assumptions, the second to illuminate what potential there is for future timber harvesting.
Marknadsundersökning om markägarens val av skogspartner
The driving forces from the forest owners point-of-view was studied on a market where several buyers attend to procure round-wood. It was concluded that forest owners prefer personal contacts to other means of communication, but that it is essential that the initial contact is a personal letter on paper. Furthermore, although price is always important, long standing relations is asked for. The buying companies need skillful experienced buyers that can provide more than just quick closures of deals..
Insect communities inhabiting Inonotus radiatus growing on Alnus glutinosa trees at northern and southern shores of boreal lakes
This is a study of the insect community associated to the wood-decaying fungus Inonotus radiatus found on Alnus glutinosa trees growing in riparian forests at the northern and southern shores of boreal lakes in the province Uppland. Little is known about this particular bracket fungus and its inhabitants. Insects were reared out at the laboratory from samples of fruiting bodies of the fungus taken at five lakes. During the fieldwork in 2009, data about several environmental variables was also taken. After the rearing period, these variables and their effects over the insects were analyzed.
Exportmöjligheter till tyska prefabhusindustrin : Wood Westerbotten, en case-studie
Projekt Wood Westerbotten är ett samverkansprojekt initierat av Exportrådet. Syftet är att öka försäljningen av ämnen och komponenter för trävaruproducerande företag i norra Sverige. Tyngdpunkten har dock hittills varit Västerbotten där projektet startade. Produktområdena är bygg, trappor, fönster, dörrar, kök och möbler.
Stommen i projektet är att hitta kunder på en exportmarknad, framförallt England, Tyskland och Benelux-länderna.
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.
Jämförelse mellan en träbro och en betongbro : En LCA-analys med fokus på koldioxidutsläpp samt en LCC-analys
This report is a thesis for collegeengineering program in structuralengineering at Uppsala University andwas commissioned by the Swedishcontractor Svevia. The study aims toprovide an overview of the mostbeneficial bridge material from bothenvironmental and economic point ofview.The life-cycle analysis covers onlycarbon dioxide emissions, since it isthe most spoken of in today?s climateagenda. Furthermore, this study aims tohighlight which parts, of the systemboundary, that contributes to greatercarbon emissions for the wood- and theconcrete bridge.The life-cycle cost analysis wascalculated with a lifespan of 40 yearsand covers the basic cost of investment,operating and maintenance, anddecommissioning costs.The analyzed constructions in this studyare existing projects that are almostcompleted. Both bridges were designed tohandle loads up to 60 tons.
Pellets - en framtidsmarknad?
With higher prices for oil and increased focus on fossil fuels impact on the environment the heating sector are searching for alternative fuels. Pellets are a quite new product whose production has risen exponential in recent years. Today there are small-, medium-and large-scale users, where the large-scale consumers are the heating sector. The heating sector is mainly using oil to cover the increased demand during cold periods.
The purpose of this study is to analyze the potential of pellets if it would replace thermal power plants oil and coal. The study will also analyze the economic impact a conversion would mean for a heating plant and if the pellet is a reasonable substitute.
2008 statistics from the Swedish district heating association were analyzed and a calculation was performed to determine how many tons of pellets is needed to replace coal and oil.
Geografisk prioritering av CTI-utrustad virkestransportkapacitet
Previous studies of central tire inflation (CTI) in truck transport of roundwood have shown potential benefits to include more even wood flow and reduced road damage. The greatest benefits are found to be during periods of low bearing capacity such as spring thaw. No previous studies have examined geographical variations in the potential benefit of CTI-equipped trucks. The aim of the study was to develop and use a simple method for geographically prioritizing the use of CTI-equipped trucks within a forest company´s sector of activity.The host company for the study was Holmen Skog. The area studied consisted of Holmen Skog?s entire sector of activity extending from the province of Västerbotten to the province of Småland.
Det goda hemmet och det ideala barnet : Svenska fosterhem för finska barn i Sverige genom Hjälpkommittén för Finlands barn i Uppsala län 1941-1949
Syftet med denna uppsats är att analysera mansbilden av karaktären Edward i filmen Edward Scissorhands (Tim Burton, 1990). Genom attstudera hans personlighet och egenskaper ur olika perspektiv, som kan uppfattas som både manligt och kvinnligt, har jag försökt att ta reda på vem denna utstickande karaktär är.Med hjälp av genusteorier och jämförelser av tidigare filmatiseringar som Ed Wood (Tim Burton, 1994), Sleepy Hollow (Tim Burton, 1999) och The cabinet of Dr. Caligari (Robert Weine, 1920) har jag även kunnat fördjupa mig i mansbilden av Edward. Jag har dessutom fokuserat kring Tim Burtons säregna filmskapande, men också kring stjärnskapet hos Johnny Depp, skådespelaren som Burton ofta samarbetar med.Edward Scissorhands har visat sig vara en man med både manliga och kvinnliga attribut, vilket gör honom till en icke stereotypisk man som saknar hjältemod och en muskulös kropp. Trots det så tyder inget på att han är mindre man bara för att han har mer eller mindre egenskaper som generellt uppfattas som manliga.
Miljöhänsyn vid offentlig upphandling :
One of the biggest challenges in the human history is to prevent environmental pollution. Everybody has an indirect or direct influence on the environment through his or her consumption. The stakeholders are not just interested in price and quality, they are also interested in the circumstances of production and how this affects the environment. By taking environmental concern in public procurement it is possible to speed up the environmental adjustment of services and products. Environmental awareness has become more and more self evident in the environmental work.
Stabilisering av insektsangripna möbler : en jämförande studie av konsolidanter
Denna rapport är en jämförande studie av utvalda konsolidanter som används till att stabilisera nedbrutet insektsangripet trä. Av de trägnagande skadeinsekter vi har i Sverige är det främst den strimmiga trägnagaren som är intressant i möbelsammanhang. I rapporten beskrivs den strimmiga trägnagaren, en liten skadeinsekt som kan åstadkomma stor skada om den får verka ostörd. Insekten finns utspridd i hela Europa och är ett stort problem då den angriper alla typer av träslag. Nedbrutet insektsangripet trä förlorar sin styrka och kan behöva konsolideras genom att injicera konsolidanter in i träet.
En studie av sedimenttransport, död ved och kantzoner längs två vattendrag i Kilsbergen - från skog till slätt :
Headwater streams are affected by anthropogenic impacts at multiple scales.
One aspect of human impact is sediment transport associated to the
abundance of stream structures as large woody debris and the composition
of the riparian zone from forest to agricultural landscapes.
Riparian buffer zones and stream structures like dead wood are considered
as generally important structures for protection against an increasing
amount of sediment particles in the water. Hence, in this study these
structures were quantified in thirty different stream segments on land and in
the water.
To measure the transport of sediment Whitlock-Vibert boxes were used in
three different types of landscapes; forest, transition and fields. The boxes
were left in the stream segments for three months, the taken up and dried
and weighed. The results showed that the transition-land in Frösvidalsån
had the highest sediment transport. The second highest transport of
sediment was in Blackstaån at the fields.
AHA in northern Sweden ? a case study : conservation values of deciduous trees based on saproxylic insects
AHA is a Swedish abbreviation of "reveal threatened park and avenue trees" and is a method to assess the conservation value of individual trees, mainly in the park environments but also in natural stands. This method has previously only been practiced in southern Sweden (Sörensson 2008). To see if this method could provide satisfactory results in northern Sweden, I have studied it in areas around the Umeå River. This was done by studying the relationship between trees with different classifications of conservation value (as classed by the AHA method) and their content of species (species richness and abundance). Insects were collected using trunk window traps in a period of 13 weeks during the summer of 2014.
Färsk ved till Hallstaviks pappersbruk :
Hallstaviks papermill is an industry plant within Holmen Paper. Hallstavik is a mechanical
mill and produce newspaper and journal paper. During year 2000, Hallstavik used
approximate 1.200 m3f spruce, either as logs or chips from sawmills. Due to that the
production is running continuously the mill also needs raw material at the same rate. At some periods the supply of raw material cannot keep up pace.