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1177 Uppsatser om Forest fuel - Sida 15 av 79

Alla vill beta men ingen vill bränna : skogshistoria inom Särna-Idre besparingsskog i nordvästra Dalarna

In this work I have tried to reconstruct the forest history within Särna-Idre forest common in northern Dalarna from the 19th century until present time. The Särna-Idre region has been an extensively used landscape for a long time. Pollen which indicates grazing has been found in samples orginating from the 10th century. Early travellers from the 18th and 19th centuries seem to have been passing trough a "used" landscape. Burned forests on naked ground are described as common. Also large areas are mentioned as undisturbed with lots of large trees, snags and dead wood.

Felbegreppets tillämpning på skogsplantor

Uppsatsen behandlar felbegreppets tillämpning på skogsplantor. Lagstiftningen inom området skog och skogsplantor är relativt omfattande men skogsplantor är biologiska produkter varför lagstiftning inte helt kan förhindra att skador eller sjukdomar ändå uppstår. Det är helt enkelt inte möjligt att framställa skogplantor utan att en viss andel av dem är behäftade med fel. Då det är en mängd sammanverkande faktorer som kan bidra till skador eller plantors död kan det vara svårt att fastställa om orsaken till skadan/plantdöden var att hänföra till plantorna eller faktorer i uppväxtmiljön. Svårigheter att fastställa orsaken kommer därför bidra till svårigheter för skogsägarna i samband med reklamation.

Data och metodik för utbytesberäkning - en studie på Medelpads Skogsförvaltning

To manage the industry?s need of wood assortments in a optimal and cost effective way the forest companies need to have knowledge of the actual standing volume and the yield of the planned clear cuts. The mean volume of the trunk is also important since it is important for the contractors prices. Today the total volume are estimated either with Näslund (1940) or Brandels (1990) functions of volumes, and the yield is estimated with Rune Ollas (1980) function for trunks and stands. The purpose of this study has been to answer the following questions: How good is the yield forecast with data collected with currently used methods? How well can the yield forecasts became with data collected according to the instructions? How well can the yield forecast be with data collected according to the instruction and calculated with the program Aptan for theoretical bucking? The study has been initiated and financed by SCA Skog AB.The material consisted of a number of randomly selected objects ready for clear cut.

Gödslingsstrategins inverkan på Holmen Skog, Umeå distrikt

This thesis analyzes the effects of different fertilization strategies on forest management at Holmen Skog in Umeå district. Harvesting volumes, net present values and fertilization intensity are presented for each fertilization scenario. The planning reserve (percentage area older than minimum final felling age) was also analyzed in this study.The thesis covers the analysis of five different fertilization scenarios, varying in fertilization intensity, from no fertilization at all, to fertilization at every harvesting operation (thinning or final felling). A sub-study was also carried out so the reader in detail can see how the different fertilization scenarios affect individual forest stands of different nature. The analysis has been done with the planning tool PlanWise, which is an application of the Heureka analysis and planning system.

Integration av simuleringsmodeller för bränslesystemet i JAS 39 Gripen

In this final thesis two simulation models have been integrated. The simulation models are models of JAS 39 Gripen?s fuel system, software and hardware. The time consuming and costly work to develop software has made the department of fuel system to build two models in Xmath/Systembuild. The software model also simplifies the comprehension of how the software in the control computer of the fuel system works.

Påverkan av skogsbrand på litiska arkeologiska fynd ? experimentell simulering av brand

This is a paper about the effects from smoldering fire on lithic objects from an archaeological view. The introduction gives the background to this paper, a short orientation to forest wildfires and why the work is limited to: flint, quartz, quartzite and slate. Material and methods describes the stone materials and the setup that was used in the temperature logged tests with three replications for each type of material. The fuel in the burnings was peat on a bottom of sand. Flint showed a more drastic effect from heat compared with the other materials. Slate seems to have greater tendencies to change to darker colour and luster at lower temperatures than the other materials.

Exercise pens as an environmental enrichment for laboratory rabbits

This thesis analyzes the effects of different fertilization strategies on forest management at Holmen Skog in Umeå district. Harvesting volumes, net present values and fertilization intensity are presented for each fertilization scenario. The planning reserve (percentage area older than minimum final felling age) was also analyzed in this study.The thesis covers the analysis of five different fertilization scenarios, varying in fertilization intensity, from no fertilization at all, to fertilization at every harvesting operation (thinning or final felling). A sub-study was also carried out so the reader in detail can see how the different fertilization scenarios affect individual forest stands of different nature. The analysis has been done with the planning tool PlanWise, which is an application of the Heureka analysis and planning system.

Köp av skogsfastighet : en fallstudie

The price of Swedish forest properties has gone up by 77 percent during the past five years. Amongst private forest managers the high price level signals optimism and confidence for the future. Many forest owners manage large capital in the forest and a planned economy is to a larger extent demanded to achieve a positive economic result. Forest is long-term and to maximize a single year without planning for the years to come results in less optimization of the parameters available to achieve a favourable economic result. This case study investigates the investment of two forest properties situated in Götaland. The management of the forest has been planned for both properties during a period of ten years.

Vätedriven förbränningsmotor : Klarläggande av framtida hållbarhet

Today when new and harder demands on CO2 emissions are developed, vehicle manufacturers must work to develop new engine solutions to new kinds of fuels to replace fossil fuels. A fuel that could be applied is hydrogen. When hydrogen is combusted only water vapor occurs. Hydrogen is known to be explosive and flammable. These properties are both good and bad for combustion.

Transporter på väg - En studie över Sveriges lastbilscentralers metoder för att möta ökande drivmedelspriser

Background and problem: In the last few years the threat against the environment and especially the emissions of carbon dioxide has become increasingly debated. The government have set up a goal to lower the emissions of carbon dioxide with 40 percent until 2020 compared to the level in 1990. The emissions in the transportation sector have, in contrast to the total emissions, increased since 1990 and will continue to increase unless powerful control measures are implemented. The lorry centres have to use strategies to answer to these external threats which lead us to the two questions of this thesis: - What methods do the lorry centres use actively and which do they consider as the most important methods for fuel saving? - Are there any differences which methods small, medium and large centres considers as important? Purpose: The main purpose of this thesis is to examine which methods lorry centres use actively and which they consider as important for fuel saving.

Analys av linjetaxering i samband med gallringsinventering med avseende på kvalitet, tillförlitlighet och framtida utformning

Modern forest owners are very familiar with forest management and forest economics. Therefore they have high demands for quality in forest operations. Guarantee of quality in the shape of self-checking activities is an important tool to guarantee a well managed forestry operation. To meet the forest owners? demands on guarantee of quality and the entrepreneurs wish of an easy method for self-checking, the forest owners association, Södra skogsägarna, has developed a new method for thinning inventory. The purpose of this study is to evaluate the method that is used for self-checking and to find ways to develop and improve of the method. The data has been collected by inventory in a number of stands with circle-area survey and with strip survey, which is method that is used for self-checking. The results show that the strip survey does not diverge more than ±10 % in measuring values of basal area, number of stems, roads share, thinning quotient, outtake of basal area and total volume compared to circle-area survey.

Skogsvård hos privata skogsägare : vilka åtgärder utförs och av vem?

Many participants in the Swedish timber market procure raw material from private forest owners. They often also offer forest services to ensure reforestation after final felling. Selling silviculture services can be a part of creating a long term relationship with the landowner for future timber purchases. The Swedish Forest Agency monitors forest rejuvenation results in the entire country. In the latest survey (2006 - 2008) the proportion of approved regeneration area was 78%.

Reducering av en komplex produktstruktur : - En studie av bränsletanksinstallationen på Scanias lastbilschassier

The product structure of the fuel tank installation is one of the most complex product areas at Scania. Caused by the number of parameters, which affect the fuel tank installation, a product structure is created which is very difficult to handle. Knowledge exist that the structure in a nearby future will be considerable more complex. The purpose of the study has been to understand in why this complexity exist and find ways to break the trend of a growing product structure. The goal was to achieve a more standardized fuel tank installation.A theoretical study was performed in order to bring knowledge in relevant areas both in general theory but also in documentation at Scania.

Prestation i traktplanering

This study was an assignment for the company Holmen which is located in the region of Örnsköldsvik, Sweden. The study was focusing on the responsibilities of a forestry planner during the planning season. The study was investigating about how much time the planner spent in the office, in the car and out in the forest. Any other issues that would cause delays were also identified. To be more effective and to increase the number of objects to a district bank, a better preparation in the planning stage (for thinning?s or clear cuts) is needed as well as faster transition on to the next area.

Slopade importtullar på etanol : En analys av framtida ekonomiska effekter

För att skydda den europeiska produktionen av bränsleetanol har EU satt upp höga tullar på importerad etanol. Vi har analyserat hur marknaderna för socker och etanol fungerar i Brasilien och EU, därefter försökt förutse vilka samhällsekonomiska effekter ett borttagande av importtullen i EU kan ha. Vi finner att etanolpriset i EU sjunker, därmed ökar efterfrågan. Bensinkonsumtionen ökar på kort sikt i både EU och Brasilien, då ett lägre etanolpris medför ett lägre pris på bensin via den inblandningskvot av etanol som finns i vanlig bensin. På längre sikt kan så kallade ?flex fuel?-bilar bli allt vanligare och bensinkonsumtionen kan avta.

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