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2171 Uppsatser om Springback and density of the compressed wood. In addition - Sida 6 av 145
Fältmätningar av limträbalkars elasticitetsmoduler : utvärdering av tre mätmetoder
This study investigates three different methods for evaluating MOE,Modulus of Elasticity, in field measurements. The purpose is toinvestigate the possibility to use dynamic measurement methods infield measurements that hitherto (2010) has been performed with staticmethods. The objects of investigation are 20 glulam beams. The firstfield measurement took place in november 2007 and applied a staticmethod based on the standard SS-EN 408. The second measurement,described in this study, took place during summer 2010, and appliedstatic as well as dynamic methods.The MOE of wood is affected by a range different factors.
Movement patterns of Eurasian lynx (Lynx lynx) around their kills in southern Sweden
During the last ten- fifteen years the Eurasian lynx (Lynx lynx) population in southern Sweden has increased considerably. This area has a high density of both people and roads and have a higher roe deer (main prey of lynx) density than the rest of the country. Movement patterns such as how long animals utilize their kills and how far they travel from their kills between revisits is unknown for lynx in southern Sweden. The aim of this study was to examine how different factors affected the time lynx used their kills and the distances they travelled from the kill between revisits. The data was prepared and calculated using ArcGIS and the study is based on 98 ungulate kills and 12 lynx individuals.
Ojämn addition och ackommodationsamplitud hos presbyoper
Syfte: Syftet med denna studie var att se om presbyopin, det vill säga minskningen av ackommodationsamplitud, utvecklas likadant i båda ögonen. Syftet var även att se om en ojämn addition i vissa fall gav bättre subjektiv respons än en binokulär jämn addition.Metod: Studien innefattade 33 deltagare där samtliga var mellan 43-57 år. Med hjälp av en RAF-stav mättes den monokulära ackommodationsamplituden för höger och vänster öga med push-up/push-down metoden. Utöver detta gjordes en binokulär och en monokulär additionsbestämning. Skilde sig resultaten åt från dessa additionsbestämningar fick deltagaren bestämma vilken styrka som subjektivt gav bäst upplevda synskärpa.Resultat: Resultaten visade att 11 deltagare hade en skillnad >0,25 D i ackommodationsamplitud mellan ögonen.
Clear-cut and substrate characteristics important for the occurrence of the beetle Upis ceramboides
Disturbances, such as fire and wind, are important for saproxylic beetles (= beetles depending on decaying wood) to gain substrate in boreal forests. Clear-cutting is an example of a man-made disturbance. Measures such as prescribed burning have been made to resemble natural disturbances. The aim of this study was to see which clear-cut characteristics are important for the occurrence of the saproxylic beetle Upis ceramboides.
This is a species favored by open habitats and is said to respond positively to forest fires. The distribution area in Sweden for this species has decreased during the last two centuries and I wanted to see if there were differences between clear-cuts in Hälsingland, where it is very
rare and decreasing, and Norrbotten where this study was conducted.
Skogsbristen i Smålands bruksskogar : en studie av träkolsförbrukning vid Storebro Bruk 1793-1850
The forest in the county of Småland has been utilised for a long time. One of the most
important forms of utilisation of wood has been charcoaling for the benefit of the iron
industry. Shortage of forest in relation to the iron industry, was discussed already in the 17th century in Sweden. The aim of this study was to analyse the purchase and consumption of charcoal at Storebro Bruk, an ironwork in Småland, during the period 1793-1850, as well as analyse the shortage of forest at the time. To determine the utilisation of the forest in the area, I have used historical sources from Storebro Bruksarkiv.
Tidsåtgång för rundvirkesmottagning på Södra Cell Mörrum
This study was made for the round wood transport company MT Transport AB. Time studies were made in order to analyze time consumption on the mill site for timber trucks delivering round wood at the Södra Cell Mörrum mill. The most interesting was to see how much of the time spent at the factory that was waiting time. In three weeks the study was going on and the drivers were clocking it themselves..
Upptryck : En jämförelse mellan RIDAS och internationella riktlinjer
Old hollow trees of oak contain a large amount of wood mould. Unfortunately, these trees have in the last century been greatly reduced in numbers. It has resulted in that species that depend on these habitats, saproxylic species, have become at risk to decrease in numbers or die out regionally. Previous studies have shown that the volume of wood mould is an important factor for occurrence and population size of saproxylic organisms. The aim of the present study was to examine how the volume of wood mould varies among ash (Fraxinus excelsior), lime (Tilia sp.), maple (Acer platanoides), aspen (Populus tremula) and oak (Quercus robur).
Biomass losses during short-term storage of bark and recovered wood
Storage of biomass is associated with problems like heat development, biomasslosses, and reduction of the fuel quality. Certain processes such as biological- andchemical degradation are responsible for these storage problems. This master?sthesis was carried out at Vattenfall Research and Development AB and is alignedtowards quantifying the biomass losses from short-term storage (1-2 months) ofbark and recovered wood. The biomass was stored in outdoor piles during differentseasons, campaign 1 (summer) and campaign 2 (autumn).
Flottledsåterställning i norra Sverige: : effekter på habitatkvalitet och populationstätheter av juvenil öringar (Salmo trutta L.)
In an effort to evaluate the effects of restorations of float ways on population density of stream dwelling fish in relation to the changes in habitat, I studied the physical habitat restored and channalized sites and their population density of brown trout (Salmo trutta L.) in three streams in the municipality of Sorsele.
The differences between the channalized and the restored sites where most noticeable regarding substrate which where generally coarser in the restored sites. The analyses showed that the proportion of habitat that where suitable to the age class 0+ where significantly lower in the restored sites compared to the channalized sites. Regarding age class ?2+, no statistical differences in habitat quality were found.
Hästars aktivitet och liggtid på madrasserade gummimattor i box
Sleep is essential for all mammals and they all have different sleep patterns. Wild horses normally spend 2-8.5% of a 24-hour period in recumbent position while stabled horses lie down 11-20%. To fulfil the need of rapid eye movement (REM) sleep the horse must lie down with support against the ground for the head. The lying behavior can be affected by external stimuli such as age, food intake, bedding materials and if the horses feel safe or not. This study investigates the lying behavior of horses on different bedding materials; wood shavings and filled rubber mats (HIT SoftBed®).
Uppgradering av biogas med aska från trädbränslen
The Swedish production of biogas was 1,5 TWh 2011. About half of the production was used as vehicle fuels. The cost for upgrading biogas depends on the size of the biogas plant and its gas production. If the gas flow is low the cost will be high. However, further development of existing upgrading technologies or development of new ones, have good potential to decrease the upgrading cost for small scale biogas plants.
Akustisk mätning av U-värde
This pre-study investigates the possibility of U-value measurements through an acoustic method. A hypothesis about an acoustic model built on acoustic theories combined with U-value theories is presented to answer the questions:
? Can U-value theory be combined with acoustic theories?
? Can the coefficient of heat be affirmed trough an acoustic measurement?
The idea for this dissertation begun with a logical idea in mathematical similarity, between the coefficient of heat transmission units and sound intensity units.
The U-value theory is based on assumptions such as initial resistance for inner walls and initial resistance for outer walls. The resistance in the material is interpreted through sound intensity theory.
The argument is built upon mass law theory, which means if the frequency or thickness of the material layer doubles it implies an increase of sound reduction by 6 dB.
Kvinnliga virkesköpare inom Holmen Skog
Holmen Skog has only five out of 70 wood buyers who are women, This report is seen as a step in the process towards gender balance in the company. This is a problem that is equal over the entire forest industry in Sweden. They all think that sexual equal workplaces are very important to remain competitive, see things from different perspectives and development of the company.
The survey was done by sending out questionnaires to all women who work and have worked as a wood buyer at Holmen, and as many men of both categories. These four categories became a total of twenty persons. To map the industry another questionnaire was sent out to the six largest forest companies in Sweden.
The survey found that female wood buyers not finished their work earlier than men did, as they thought before.
Analysis of eucalyptus plantations on the Iberian Peninsula
This thesis analyses the prerequisites, profitability and competitiveness of eucalyptus plantation on the Iberian Peninsula and in Brazil. The thesis has a macro perspective and analyses a typical hectare of eucalyptus in each studied region.
A survey methodology was used as a strategy to cover a broad perspective using expert respondents.
The regions studied on the Iberian Peninsula were the ones found suitable for eucalyptus plantations from an economic point of view. The studied regions were Huelva in the South West of Spain, Galicia in the North West of Spain and Portugal.
Användande av diffusionsspärr vid tilläggsisolering av äldre byggnader med trästomme
In the current situation a big part ofthe settlements that exist in Sweden isin need of renovation and energyefficiency in order to survive.Therefore, also many of the older houseswith a wooden structure are in a need ofenergy efficiency, which can be done ina variety of ways, including addinginsulation.This project deals with whether the useof a diffusion barrier or a vaporbarrier affects a wall structure byadding insulation to an older house witha timber frame. The insulation materialswhich are concidered in thisinvestigation are mineral wool and woodfiber insulation. Efforts are focused onthe effects of moisture on theseinsulation materials.To demonstrate the differences thatarise the moisture measurement programWUFI have been used to simulate avariety of wall designs. These designsare developed in consultation with theconstruction carers who are active inthe industry.Using WUFI graphs illustrating themoisture levels of the wall structureswere obtained and from these conclusionsvould be drawn. The work demonstratesthe differences that arise when using adiffusion barrier or vapor barrier inwall construction.