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699 Uppsatser om Variable air volume - Sida 13 av 47
Sällskapet örtagårdens vänners trädgård i Vadstena : aktuellt växtinnehåll i historisk belysning och med sikt framåt.
Dead wood is important for many species. The amount of coarse dead wood (diameter >10 cm) is much lower in managed forest than in unmanaged forests. Stumps constitute the largest proportion of the volume of coarse dead wood in managed forests. Since stump harvest for biofuel may increase, the amount of dead wood will decrease even more, which may threaten biodiversity. The first aim of this study was to compare the amounts of fine woody debris (FWD, .
Att återställa en naturlig ordning : skogshistoria och restaureringsbränning i Långsidbergets naturreservat
During the late 1800s fire suppression became increasingly effective in northern Sweden which led to decreased areas of fire-disturbed woodland and successive changes in the structure of forests. In the long run this can pose a serious threat to fire-dependent and fire-favored species. Today some fire-prone forest reserves are burned as a nature conservation act. Often partial cuttings are made before burning, with somewhat different motives. The purpose of the study in Långsidberget nature reserve was to give a general picture of forest history and its affect on today?s forest condition, and to show how partial cuttings affect burning conditions and results.
Långsidberget is located close to areas that were colonized during the Middle Ages.
Förröjning i förstagalling - vad kostar det och följer utförarna instruktionerna?
This report is a B.Sc. Forestry thesis work at the school for Forest Management, SLU.
The work was an assignment from the forest owners? association Mellanskog.
The aim of the work where to investigate the economical result of removing undergrowth trees before first thinning, and a follow-up of the contractors and their compliance with Mellanskog standards.
This thesis work was divided in three parts: The first was to find a relation between the net volume from the first thinning and the cost of cleaning undergrowth trees. Secondly there was a follow-up in the field, to investigate whether the contractors have done the undergrowth cleaning according to Mellanskog?s directives.
Epixylic lichens and bryophytes in young managed forests : substrate preferences and amounts of dead wood
Dead wood is important for many species. The amount of coarse dead wood (diameter >10 cm) is much lower in managed forest than in unmanaged forests. Stumps constitute the largest proportion of the volume of coarse dead wood in managed forests. Since stump harvest for biofuel may increase, the amount of dead wood will decrease even more, which may threaten biodiversity. The first aim of this study was to compare the amounts of fine woody debris (FWD, .
Småskalig säsongslagring av solenergi för uppvärmning av bostäder : Simulering av lagerutformning och konsekvensen av adderade uppvärmningsbehov motsvarande en pool och ett atrium
The sun is a huge energy source with great potential of providing energy to the heating of homes and other buildings in an environmentally sustainable manner. In order to provide buildings with energy from the sun it is necessary to transfer the energy supply over time to when the demand arises. By storing the heat in a seasonal storage, solar energy from the summer can be used in the winter when the demand for heating is greatest.Today's existing plants are mainly in Europe and particularly in Germany. These facilities are designed to supply heat demands greater than 400 MWh and covers about 40-50 % of this need which consists of energy for space heating and domestic hot water. How much of the heat demand that is covered, the solar fraction, is partly due to losses from the storage which in turn is connected to the surface area of the storage.
Realisering av returer vid rundvirkestransport med lastbil : hinder, möjligheter, vinster och vinstdelning
Holmen Skog, region Norrköping, is located in an area with good potential for backhauling because a large number of geographically scattered mills. However, despite these factors there are many difficulties preventing the realization of this potential. The purposes of this study were twofold. First, from a hauling contractor perspective, to calculate backhauling profits and suggest a profit sharing scheme. Second, to identify and quantify obstacles and possibilities for realization of backhauls.The study required the use of three different types of methods.
Kundrelationer - mellan Setragroup AB och bygghandeln :
This study is made in cooperation with Setragroup AB. Setra is Sweden?s biggest sawmilling company with a turnover of almost 6 billion SEK. 45% of the produced volume goes to the Swedish market where the customers are the DIY-sector and industrial customers. Setra as well as the other Swedish sawmilling companies operate in a very competitive environment.
Translationsnoggrannhet i läsningen mellan tRNA och mRNA : En analys av variationen i den maximala diskrimineringen d i initialselektion
The purpose of this thesis is to analyze the variation in the maximal discrimination of the interaction between cognate and a non-cognate codon and anti-codon (also called the d-value). The variation was analyzed with a multiple regression model with the d-value as the dependent variable and with the codon position and the different mRNA and tRNA bases as independent variables. The result of the analysis not only confirmed earlier studies that the maximal accuracy was highest in the second codon position and lowest in the third codon position but we also found significant relationships and interaction effects..
Hopfällbar hjullösning
In many products a compromise between ground clearance and the required space to store the product has to be made. This problem attracted the attention of the authors of this thesis.The objective of this project is to develop a functioning solution to a foldable wheel. The solution should be applicable to several types of product groups. A limitation for this work has been made so that the work only covers solutions for lighter vehicles.The purpose is to drive this project forward, so that a solution can be found. Furthermore the purpose of the report is to clarify how the authors proceeded to design and construct the wheel according to a fixed specification.
Contortatallens roll för virkesförsörjningen på Holmen Skog, Region Iggesund : konsekvensanalys av fyra hushållningsstrategier för contortatall
Large areas of Lodgepole pine (Pinus contorta var. latifolia) were planted in the 1970s - and '80s. The purpose of the fast-growing species was to increase growth and with short rotation periods allow a rapidly increased harvest level. Today a large proportion of the young forests owned by Holmen Skog, Iggesund are covered by Lodgepole pine and an active forest management is required to spread the harvested volume over time which is desirable by a market perspective. The purpose of this essay is to investigate the possibility of spreading the harvested volume of Lodgepole pine over time.
Från gles skog och brokiga ungskogar till homogen produktionsskog : en skogshistorisk studie av Hällforsmarken under 1900-talet
The forest in the northern part of Sweden has changed dramatically during the last centuries. The forest has gone through a large-scale transformation, from it being only used locally for domestic purposes to becoming very important raw material for Sweden in the industrial age. The strategy by foresters during the second half of the 20th century has been to create pure production forests for commercial forestry. This has mainly succeeded and we have today homogenous production forests that give a high profit to the owners. The aim of the study is to compare the state of the forest in the former state forest Hällforsmarken in the years 1925 and 2000 and to interpret the changes which has taken place.
Bootstrap som hjälpmedel att öka noggrannheten och bedöma precisionen vid probitregression, med tillämpning på hörselmätningar
In many biomedical contexts, e. g. when evaluating hearing disorders, the data obtained can be described as pairs (x1, y1), ?, (xn, yn) where x is a quantitative variable and y a 0/1 variable whose probability of taking the value 1 is a monotonic function of x. One way of analysing such data is to perform probit regression; thereby two parameters, b0 (= the constant) and b1 (= the slope) are estimated; the interest centres around m = -b0/b1, i.
Sambandet mellan kontroll i arbetet, psykologisk flexibilitet och välmående
The work organization variable control and the individual characteristic psychological flexibility are two concepts that affect employees? well-being at work.This cross-sectional study examined the extent to which these variables correlated with burnout, mental health and job satisfaction among homecare workers in Sweden (N=68). As hypothesized, results showed that both control and psychological flexibility were associated with burnout and job satisfaction. Findings also showed that psychological flexibility was associated with mental health. Moreover, the results indicated that there is an interaction effect between control and psychological flexibility in relation to these variables.
Att rekonstruera förhistoriska odlingsförutsättningar : första steget i en metodutveckling.
The aim of this work is to take the first step into a development process, with the intention to find a way of making prehistoric soil fertility a variable in archaeological landscape analysis. A pilot study is performed on the Mälar basin area, where four topographical and geological factors are reclassified and then combined, resulting in a map which expresses a relative indication of agriculture potential. The map is then compared to the distribution of Migration Period graves and gold finds. This, however, does not mean that the technique is tied to a certain prehistoric period. Because the work is intrinsically experimental, the technique as a whole is finally discussed and evaluated, and suggestions of improvements and further studies are made..
Commercial thinning and its potential for contribution to the timber supply in British Columbia?s Interior forests : a look at Finnish and Swedish forest practices and their applicability in British Columbia?s Interior forests
Thinning is the partial removal of trees in a forest stand prior to final harvest. The term can be divided in pre-commercial thinning where little if any volume is removed from the stand and commercial thinning where removals are intended to provide a positive economic result. From a silvicultural point of view, the goal of thinning is to enhance future crop tree quality by removing low-quality stems and providing sufficient space for the accelerated development of retained ones (Huuskonen & Hynynen, 2006).
The goals of this study was to see if commercial thinning could positively affect the short and medium term timber supply (MTTS) in the Interior regions of British Columbia (BC), and whether or not Scandinavian forestry practices could be adopted in the BC context. The mountain pine beetle (Dendroctonus ponderosae Hopkins) has created significant forest planning problems in BC. The annual allowable cut (AAC) was raised to capture beetle-killed timber while still merchantable.