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1000 Uppsatser om Moisture; Solid wood; Vapour barrier - Sida 19 av 67

Effekt av karbonatisering med biogas på aska från trädbränslen

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.

Förekomst & kostnad av kapsprickor i stormaskadad skog

The aim for this study where to investigate the frequency of cutting cracks in saw timber harvested in the storm-damaged forests in regions where the storms Hilde and Ivar hit. The idea for this work came from one of the region?s biggest actors, SCA Skog and Jämtlands district. The purpose where to find out how big proportion of the saw timber that contains cutting cracks, their financial cost in lost wood value and also give advice and suggestions on how to work against the frequency of cutting cracks. For the field-study some guidelines where used to make sure that the samples were taken under the same conditions, they were: ? The field-study must be performed under harvesting of storm-felled forest, which are horizontal/inclined trunks. ? The averaged sized tree will make it possible to harvest saw timber. ? The trunks can?t be root cut. A methodology called in Swedish ?Trissmetoden? was used because it is the most frequent used methodology in earlier performed studies and the only one that can be used I field. Under the field-study data were collected from 570 saw timber logs, 30 logs from each one of the tested harvesters.

Två nya trailerkoncept för transport av rundvirke hos Stora Enso : en analys av prestation och flexibilitet

The need for roundwood transport capacity vary throughout the year. The need during a period is influenced mainly by the volume transported the period, the number of days during which transport can be carried out, seasonal variations in road conditions and the weight of the roundwood, and the origin of the wood (private forest owners/ forest companies). The need for transport capacity generally increase during the winter and in spring, after thawing. Lack of logging trucks combined with a lack of drivers for these trucks make it hard to hire extra help during periods of increased transport capacity needs. It is also very expensive to keep logging trucks for use only during these periods. In this thesis, two new concepts based on the partial transport by truck tractors have been examined, to find out the possibility for increased performance and flexibility.

"Läroboken - min trogne vän" : En studie om hur lärare använder sig av läroboken i matematikundervisning

The textbook is one of the instruments that teachers and students have available in their teaching. For many years has textbook regarded as being too controlling and as a barrier to students development in mathematics. Textbooks primary mission is to promote learning. My study aims to provide an overview of how effective teachers use the textbook in mathematics education as well as the pros and cons they see with their work. The work includes interviews with five active mathematics teachers.

3D-modellering i AutoCAD -att skapa en digital huskonstruktion

3D-modelling in AutoCAD This thesis is done in cooperation with LB-Hus in Bromölla, and have aimed to establish a digital AutoCAD model of one of the company?s house types and to find out what opportunities there are to do visualisations in the form of images directly from the programme. Modeling has been carried out so that the very construction of the house is included. Interiors and installations, with the exception of the ventilation system, have been left out in the model. The model has been created with solid models after a comparative study made between solid models and surface models to find out which option in this case was the easiest to handle and took up the least space.

Utvärdering av ett Bränslecellsdrivet Flygplan.

 With the increases in fuel costs due to the depletion of the world oil reserves and the increase of greenhouse gasses as a consequence to using oil as a fuel many companies are looking to new and innovative ways to power their aircraft. One of these new ways to power an aircraft is using fuel cells powered using hydrogen and oxygen, thus producing nothing but water vapour and small amounts of nitrogen dioxide as well as trace amounts of other emissions. Both Boeing (1) and Politecnico di Torino (2) have shown that it is possible to build an all-electric aircraft powered by fuel cells. Both flights used small, two-seater aircraft and a constant between them was the loss of the co-pilot seat due to weight and lack of space. As this paper will deal with a commercial aircraft a primary concern is the cargo and passenger capacity and whatever impact switching propulsion system has on these.

Från Rysk Roulett till "riktigt söta historier" : Hur genus konstrueras i två läroböcker i engelska på gymnasienivå

 Denna uppsats undersöker två läroböcker avsedda för gymnasiets A-kurs i engelskämnet, Progress Gold A (2003) och Solid Ground (2003), i syfte att se vad de kan kommunicera ur ett genusperspektiv. De frågeställningar som behandlas är följande: Hur konstrueras genus i texterna i dessa båda läroböcker? Då läsaren inkluderas exempelvis i ett "vi" eller "du", förutsätts läsaren då vara antingen man eller kvinna, eller har detta inte någon betydelse? Hur förhåller sig resultaten till läroplanens mål om jämställdhet?Den teori och metod som ligger till grund för analysen har hämtats från det fält som kallas diskursanalys. Såsom den utformats i detta arbete kan metoden närmast beskrivas som en kvalitativ närläsning av materialet. Resultatet visar på att båda läroböckerna till stor del tycks reproducera genuskontraktets grundpelare, dikotomiseringen av manligt och kvinnligt samt hierarkin dem emellan som ger det manliga högre statuts än det kvinnliga.

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.

XRF-analys av förorenad mark : undersökning av felkällor och lämplig provbearbetning

X-ray fluorescence (XRF) detection of heavy metals is a cost- and time-effective method for investigation of polluted areas. Compared to laboratory analysis, XRF analysis is limited by high detection limits and uncertainties in some situations. Preparation of samples is known to affect the results of measurements.The purpose of this thesis is to bring a deeper understanding of how different factors affect the results of XRF-analysis. A large number of measurements have been made with the instruments Niton XLt 700 and Niton Xli 700. Results from measurements of lead, zinc and copper have been analysed.This study has shown that a greater moisture content will give a lower measured concentration for the same sample.

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.

Jordbearbetningsstrategier på hösten inför vårsådd på tyngre lerjordar :

It is important for today?s farmers to minimize the costs for crop establishment, because of decreased prices and support from the EU. Farmers, who plow in autumn on heavy clay soil, often do some kind of tillage in autumn to get better soil structure before spring seeding. This is especially important when growing small seed crop, e.g. sugar beet and oil plants.

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.

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