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333 Uppsatser om Yield - Sida 18 av 23

Spillningsinventering för bestämning av älgbetesbelastning på ungskog

In the 1980?s the moose population in Sweden grew explosively due to big changes in the silviculture with clear cuttings instead of single-tree selection. Clear cuttings brought big areas of young forest and therefore a lot of fodder in one place. Since this change, the discussion about how to manage the moose population has grown into a very big problem. Forest owners think that the population needs to be strongly reduced because of all the damage that is done to the young forest when the moose seeks its food, and the economic losses because of that.

Fire impact in the wood quality and a fertilization experiment in Eucalyptus plantations in Guangxi, southern China

Chinas government has a multifunctional program for a more sustainable forestry since 2000. This six key forest programs goal is to develop a more sustainable forest sector but also take environment consideration. The state forest administration in China has decided to create 5.8 million hectare of fast growing and high Yield forest. Eucalyptus has showed to have good properties for pulp and timber production and therefore Eucalyptus plantations are under development in costal areas in southern China. By adding extra nutrients, growth can be enhanced in Eucalyptus plantations.

Simuleringsprogram som verktyg vid projektering av solvärme

The government regulations for energy use in buildings will be tightened in the future. At the same time the interest in environmental classifications and certifications of buildings is increasing. This has meant a new situation for solar energy. The designs of solar heating systems are often based on experience and/or rules of thumb, rather than calculations and simulations. This thesis examines whether simulation tools, in this case Polysun, are useful in this work.

Varför emitterar inte fler svenska företag högavkastande obligationer?

Marknaden för så kallade ?High Yield Bonds? ? högavkastande obligationer ? har under det senaste årtiondet genomgått en remarkabel utveckling, särskilt i Europa. Ett ökat antal ?non-investment grade?-företag söker strategiskt att emittera dessa obligationer för att finansiera sina verksamheter, vare sig detrör sig om upprätthållandet av betalningsströmmar till leverantörer, anställda eller andra intressenter; kapitalanskaffning; företagsförvärv; refinansiering av lån; eller andra företagsrelaterade aktiviteter. Trots denna utveckling är marknaden för högavkastande obligationer i Sverige jämförelsevis liten.

Odour-mediated behaviour in codling moth, Cydia pomonella : do fermentation odours affect the attraction and oviposition behaviour in codling moth?

The codling moth, Cydia pomonella is a common pest in apple orchards and can be found worldwide. Feeding by codling moth larvae can cause a substantial decrease in apple Yield. Control methods comprise for example the use of pesticides, viruses and pheromones. As a sustainable control method, pheromones have been successfully applied to disrupt moth mating behaviour. Other behaviours like foraging, search for mating sites or host finding could be potential targets for additional odour-mediated behavioural manipulation but need further investigations of the underlying odour stimuli and behavioural plasticity. Many insects are attracted to the smell of fermenting fruit and associated microorganisms.

Tillväxtreaktion hos skärmträd i högskärm av gran i Medelpad :

Different methods for shelterwood cutting have been used in differ-ent parts of Europe since the middle ages. The use of shelter wood cutting in Norway spruce (Picea abies (L.) Karst.) forests in Sweden met a revival in the early 1990s as an alternative for the dominating clear-cutting system when silvicultural costs increased dramatically for the latter. Shelterwood cutting systems involve some possible problems but also a lot of positive effects. Among the problems are increased risk of wind throw and damage of the remaining shelter trees caused by the cutting operation. Positive effects are for example a valuable growth in the remaining trees and increased biological di-versity. This study is based on a total of 79 trees from 4 different treatments in a spruce shelterwood, cut in 1994, in the middle of Sweden (62,4º N).

Nord Pools systempris - en studie av prispåverkande faktorer

The intention of this thesis is, from a basic statistical viewpoint, to capture the relationship between the price of electricity and a sample of factors influencing the price. The thesis also aims at investigating whether knowledge about the relationship is useful when investing on Nord Pool. Tested factors are temperature, import, price of emission rights as well as a number of hydrological factors. The investigated period stretches from year 2000 until week 32 year 2007. The relevance of each factor was also evaluated yearly as well as for shorter periods in order to get a more comprehensive view of the relationship.

Tillväxt och potentiell sågtimmerkvalitet i gallringsmogna jämförelseplanteringar med Pinus contorta och P. sylvestris :

The Swedish Cellulosa Companiy, SCA, has today 280 000 ha planted with lodgepole pine (Pinus contorta var. latifolia) (?C?) which is equivalent to 14 % of its total forest area. Exotic lodgepole pine has in previous experimental stands shown a superior growth than the native Scots pine (Pinus sylvestris L.) (?S?).But also the comparison could be questioned because stand histories were was unknown and also differences in age between C and S existed.

Framtagning av beräkningshjälpmedel för tvärkraftbelastade förband med förbindare av metall.

The governing set of regulations for structural engineering in Sweden used to be Boverket, BKR. However in the beginning of the 21st century a changeover to new regulations, the Eurocodes, started.The transition was completed in year 2011 when the Eurocodes became the mandatory design work policy for all countries within the European Union. The Eurocodes were implemented to simplify and remove potential barriers to trade that may exist when countries have different design rules.  Since the changeover it has been important for all construction companies to update their knowledge base and their design software.When comparing the two calculation processes they seem similar, but there are a couple of differences worth noting.  With the new regulations, engineers will find that the process when designing joints in timber structures has changed.  What used to be a fairly easy and straight forward calculation procedure has now become tedious and time consuming.The objective of this degree project is to present a product, a dimensioning tool that will help structural engineers when computing lateral load carrying joints in timber structures.The degree project is made up of two parts where the first part is the written report describing the background and theory behind load carrying computations. The second part of the project is the actual dimensioning tool which includes several worksheets in Microsoft Excel. The program treats single and double shear connections of the following:Nail jointsScrew jointsSteel plates (thick and thin types) The user can edit the following parameters:Type of plate/ number of shearsStrength class of timber membersMember and plate sizeType of fastenerDiameter of fastenerLength of fastenerYield moment of fastenerkmod and partial factors for design load carrying capacityThe dimensioning tool was created and developed in collaboration with structural engineers at the company Byggteknik AB.

Provning av ythärdade material tänkta för
transmissionsdetaljer

This technical report describes the master thesis in material engineering called ?Testing of surfaced hardened materials conceivable for gears and shafts?. The work extents 20 academic points. Land systems Hägglunds manufactures and sells different kinds of combat vehicles and terrain vehicles. Since the demands for bigger and stronger vehicles increases all the time, so are the demands on shafts, gears and other transmission details.

Lönsamheten i vindkraft : en studie om den förväntade lönsamheten i landsbaserad vindkraft

This thesis analyzes the expected profitability in land based wind power plants. The expected profitability is calculated on the basis of a wind power project in Vartofta, Falköping. The information required to calculate the expected outcome is then concentrated to this project, which is in this thesis called project Näs. In project Näs they plan to build three wind power plants, with each an effect of 2 MWh. These wind power plants are very capital intensive investments with a long and uncertain payback time.

Beslutsunderlag för energianpassade gallringar i Västerbotten

The demand for renewable energy is increasing in Sweden. This consequently increases the pressure for and willingness to pay for forest fuels. One method to extract forest fuel from suitable commercial thinnings is the "long top method? (LT-method). With this method saw logs and non-delimbed tops are recovered, i.e.

Importance of epigenetics in animal breeding : genomic imprinting

ABSTRACTThe aim of this study was to give an overview of the evidence for genomic imprinting in livestock and other mammals as well as outline the potential use of gene imprinting in livestock breeding. Epigenetics is the mitotical and meiotical partial hereditary variation in genomic activity without any alterations of the DNA sequence. An example of epigenetic regulation is genomic imprinting where one allele?s expression differs depending on which parent it was inherited from. These parent-of-origin effects are currently overlooked in livestock production.

Åkerböna i samodling med vårvete som helgrödesensilage till mjölkkor :

The aim of this undergraduate thesis was to formulate advices regarding the use of field beans, cultivated together with spring wheat, as whole-crop silage in feeding to dairy cows. In the thesis, optimal harvest time of the field bean/spring wheat crop, as well as the feeding value and the fermentation quality, was studied. On the research station at Röbäcksdalen in Umeå field bean/spring wheat (70 % respective 30 % of normal seed rate for the pure crop) and pea/oat (70/30) was grown in field experiments both 2002 and 2003. The following year, 2004, the pea/oat crop was excluded and instead field bean and spring wheat was cultivated in three different mixed ratios (field bean/spring wheat; 100:0, 70:30, 30:70). Every year the crops were harvested at four different development stages and the green forages were used in ensiling experiments.

Undersökning av svetsegenskaper för svetsning med rörtråd kontra homogen tråd

Welding is a common method for joining of metal or plastic construction parts. This report describes several different weld methods in general terms. The report focuses on the GMAW method, specifically MAG welding.A case study has also been performed for the company Wenmec. The task received from the company was to compare the mechanical properties of joints welded with the tube electrode called Nittetsu SM-3A and joints welded with the homogenous electrode called ESAB Aristorod 12.63. Both types of weld joint were welded with the MAG method with an Argon based shielding gas with 18% CO2.

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