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413 Uppsatser om Tree cores - Sida 1 av 28

Provtagning av trädkärnor för att bedöma föroreningsgraden av klorerade lösningsmedel i grundvatten

Chlorinated aliphatic hydrocarbons (CAH´s) were used widely within dry cleaning facilities and for metal degreasing until their toxicity was discovered. PCE is still used as dry cleaning liquid. Today CAH´s are found in soil environment at places where they have been used in the past. The CAH-concentration in trees growing on contaminated land has quite recently received attention as a cheap and effective way of assessing the extent of a CAH-contamination. The method has however, not been put into use in Sweden.The aim of the study has been to investigate whether the CAH-concentration in Tree cores could be used to delineate the spread of CAH in a soil environment under Swedish conditions in different seasons.

Datering av röta i hålekar :

I have chosen in this work to examine which factors are affecting the artificially creation of a tree cavity containing decomposed wood. The purpose of the work is to find out which factors are affecting the most when a tree cavity is created, and to apply these results when you artificially try to create a tree cavity. The need to create tree cavities comes from the situation where many tree cavity living beetles finds themselves today. When existing trees are to pass out there will be no suitable inheritors yet. The work was initially to focus on cavities created from cut branches.

Det enskilda trädet som meningsbärare : erfarenheter av två trädplanteringsprojekt i Helsingborg

Individual trees can act as carriers of meaning. When a person attributes deep meanings to a specific tree, a relationship between the person and the tree is created. To avoid conflicts between users and planners, increased awareness is required of how important individual trees may be to a person. The objective of this study was to elucidate persons? relationships with individual urban trees.

Tillväxtreaktion på kvarlämnade träd i Hagners "Naturkultur" försök :

The primary goal of this study was to investigate how the radial growth of retained trees responds after thinning-from-above. The National Board of Forestry which initiated this study, was interested in whether there were differences in the growth-response between the tree species Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) Karst.). Another question of issue was if there were differences in the growth response between trees of different sizes. It is within the framework of the National Board of Forestry?s, Continuous Forests Project that these urgent questions are to be answered.

Tee Tree Oil - Ett effektivt behandlingspreparat i tandvården?

Tea Tree Oil eller TTO som det förkortas, är en olja som utvinns ur en australiensisk buske vid det latinska namnet Melaleuca alternifolia. Oljan har sedan många år använts som antiinflammatoriskt och bakteriedödande ämne. Denna litteraturstudie gjordes på 13 artiklar som svarade på tre sökningar i databasen PubMed. Artiklarna påvisar att TTO har en viss antibakteriell förmåga och kan fungera som antimykotiskt medel, men fler in vivo studer behövs för att säkerställa TTO:s effekt på olika parodontala åkommor..

Träd som berör : en intervjustudie om specifika träd i människors liv

There is no doubt about the significance of nature on the health of human beings. Not only is the tree an element of nature that is of great value to our survival, it also serves as a valuable object and symbol of human beings? enjoyment and appreciation of the environment. The purpose of this study is to present the relationship that a person may have with a specific tree. Three women and two men are interviewed about their trees and the places where they are located.

Produktionsskillnader vid olika antal sortiment

This study is done together with Sydved AB in the summer of 2012. The purpose of the study is to analyse how different quantity of assortments influence the production for forwarders and harvesters with multiple tree handling aggregate in thinning, by different tree volumes. To make this analyse a time study was performed where three entrepreneurs work has been analysed. Beside the analyse, of different quantity of assortments, has also been analysed how the tree volume and a forest fuel assortment effect the production. The result of this study shows that the quantities of assortments have a significant meaning for the production. The biggest differences are most distinct between one and three assortments in the smaller tree volumes where production goes down if the quantity of assortments increase.

Jätteträd ? inventering, bevaring, skötsel samt rekrytering :

During the summer of 2007 I was employed by Högestad Christinehofs Förvaltning AB. My main task was to make an inventory of giant trees at the estate. Högestad and Christinehof,which with their total possession of 13 000 ha of land is the biggest estate in Scania. A giant tree is a tree with a diameter in breast height more then 1 meter. Trees of these dimensions are registered by Swedish authorities. Landowners with a giant tree on their property can receive a subsidy for cutting trees that are in competition with the giant tree.(Levenskog, 2007) Giant trees are important for biodiversity in the landscape and there are important habitats for different insects, birds, bats, lichens and funguses.

Processchemaläggare för mångkärniga processorer ? Fördelning av minnesbelastning i NUMA-system

For systems with multicore processors contention for shared resources is a problem that occurs when several memory-intensive processes are executed in parallel within the same memory domain. This contention has a direct influence on the performance of the system and is a complex problem that has been recognized for a long time. An attractive and actively studied way to minimize this problem is by using a process scheduler adapted to allocate processor cores in a way such that contention for shared resources is minimized.With the introduction of multicore NUMA-systems (Non-Uniform Memory Access) the situation has become even more complex. In these systems the access time for processor cores to different memory domains vary depending on factors such as distance and load. Thus, the process scheduler also has to consider where the memory of each process is placed to minimize the distance and balance the load on each memory domain.This report presents a user-level process scheduler for a NUMA-system based on the multicore processor Tilera TILEPro64.

När trädens rotsystem får bestämma : En intervjustudie med en grupp yrkesverksamma inom anläggning av hållbara gröna miljöer.

ABSTRACTThis pilot study examines the knowledge about tree root systems amongst five treeplanting professionals. The aim is to find out the professionals? collective knowledge ofthe nature of root systems of various trees used in green areas. Furthermore; to explorehow the professionals adapt landscaped green areas to the tree root properties in asustainable manner. Questions: Which tree species have special root properties toconsider and how do the professionals utilize this knowledge? And: How do theprofessionals in general adjust planting according to the root systems of trees in areas tocreate sustainable green environments?Interviews with the professionals were performed.

Parallell beräkning av omslutande volymer

This paper presents techniques for speeding up commonly used algorithms forbounding volume (BV) computation, such as the AABB, sphere and k-DOP. Byexploiting the possibilities of parallelismin modern processors, the result exceedsthe expected theoretical result. The methods focus on data-level-parallelism(DLP) using Intel?s SSE instructions, for operations on 4 parallel independentsingle precision floating point values, with a theoretical speed-up factor of 4 ondata throughput. Still, a speed-up between 7?9 are shown in the computation ofAABBs and k-DOPs.

The shift in forest and tree limits in Troms County - with a main focus on temperature and herbivores

To better understand how various factors affect the establishment of forest and trees around the tree line-ecotone, this study was conducted in Troms County, Norway. The altitude of different forest and tree limits together with the surrounding vegetation type were collected during August 2011. Comparisons of the collected data were made with previously collected data from the same sites conducted 1914 and 1915. On average the forest limit has expanded with 26 meters in altitude, however, an expansion is not statistically significant for the whole area. The tree limit has significantly expanded in altitude.

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).

Dendroklimatologisk analys av lokalklimat vid Grövelsjön i Dalafjällen

Climate on earth is getting warmer, which effects earth?s energy balance and so forth the ocean and atmospheric circulation.  In many sub-polar regions on the northern hemisphere changes due to warming of the climate can be observed. Some examples that already have been observed are shifts in tree line, towards higher altitudes and latitudes, increased ablation of Swedish glaciers and melting of the permafrost on the Siberian tundra. In Sweden climate change scenarios tell us that it will become warmer and that a higher amount of precipitation in form of rain will be an effect from this. To study climate changes in Sweden, transition zones are useful in order to observe changes in distribution of species and animal populations.

Produktivitetseffekter av flerträdshantering

The main purpose of this study is to investigate the productivity effects of multiple tree handling in thinnings. Other important elements have been to investigate in which extent multi-tree handling is used in stands with different stem volumes and the impact of collecting partially delimbed fuelwood assortments has on harvesting performance. The study is based on data from thinnings in Sydved and contractors' operating activities. Collection and compilation of operating schedules, number of stems and surveyed volumes from several contractors and a large number of executed orders underlying the results. Multiple tree handling is used to a much greater extent at lower average stem volumes. Prediction models for productivity of the multiple-tree handling harvesters in the study differ from the productivity models for single-tree handling. In the model developed in this study productivity is not as dependent of stem volume as reference models.

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