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46374 Uppsatser om The compressed material tends to return to the original shape when it is exposed to moisture fluxations and if no form of fixation occurs. The fixation can be done mechanically in a three-layer panel construction which reduce movements in the timber. These panels have been found to be unstable and previous attempts have shown deformations in form of cupping. This study aims to evaluate the conditions for using compressed aspen wood - Sida 1 av 3092

Hårdgörning av Asp

Hårdgörning av trä syftar till att göra materialet hårdare. Detta går att åstadkomma genom komprimering, det komprimerade materialet tenderar dock att återgå mot sin ursprungsform då materialet utsätts för fukt om ingen låsning sker. Låsningen kan ske mekaniskt i en treskiktskonstruktion som motverkar träets fuktrörelser. Dessa skivor har dock visat sig vara instabila och tidigare försök har uppvisat deformationer i form av kupning. Denna undersökning syftar till att utreda förutsättningarna för att använda komprimerad asp samt att ta fram underlag för framtagning av en kommersiell produkt.Praktiska tester har genomförts för att studera hårdhet, återfjädring och densitet hos det komprimerade virket.

Energianalys av tryckluftsystem : så kan Billerud Skärblacka AB spara energi på tryckluft

Compressed air is a low efficiency media, and is thus very expensive to produce. This thesis work began by mind mapping how to create savings on the compressed air system at Billerud Skärblacka AB. Certain issues have been chosen for further studies.In order to identify the consumption of compressed air at PM 8 and 9, several measurements were made. At PM 8 there were not found any pressure drop, only large pressure variations for short periods of time. The causes of these pressure variations were not established.

"Fixar jag till mig så kommer jag må bra" : En kvalitativ studie om kuratorers uppfattning om kroppsfixering hos unga kvinnor

This study examines counselors understanding of body fixation (alt: body image fixation) as a social problem among young women aged 15-25 years. Earlier research on this subject highlights the standards and ideals placed on the female body where happiness is associated with a slim body figure. Research has shown that young women that compare their own bodies with others are at higher risk at developing an unhealthy relationship with their body, which can lead to eating disorders. The data for this study was collected through semi-structured interviews with nine counselors from youth clinics, schools and primary healthcare. The results were interpreted and analysed in the light of social constructionist perspective as developed by Berger & Luckmann and Loseke's social constructionist definition of social problems.

Förbättring av U-värde i träkonstruktion för fönster med Aerogel

When constructing a building, a number of aspects must be harmonized in order for it to fulfill requirements ? a building must fulfill requirements such a load-bearing, conservation of energy and a good indoor environment by means of, among other things, moisture proofing .Moisture problems in buildings can affect health negatively. As we are increasingly staying in indoors, demands on a good indoor environment are higher.This work starts with examining moisture problems in slab-on-ground solutions, and then links the various scenarios to moisture problems in a concrete slab of a real building. The building with moisture problems is located in Årby by in Borlänge and moisture damage was found in the slab at an apartment adjoining wall.By reviewing literature written within the field of moisture problem, making hand calculations and modeling in the program Comsol Multiphysics, judgments are made to find explanations as to why the rise of moisture occurred in the building in Årby by.Generally, the following guidelines may be used to reduce the risk of moisture problems in slab-on-ground constructions:Drying of construction moisture before laying the floor material.Using draining layer beneath the slab, to prevent capillary suction.Using insulation under the slab, partly for comfort and to establish the temperature difference between the ground and the concrete slab.Avoid direct contact between the wood and concrete, due to degradation and fouling smells that normally occurs.If necessary, use additional vapor barrier.In addition to the above, there are various methods for moisture-proof and moisture-monitoring by design or by the method ByggaF suited for the entire construction process various events..

Fuktproblematik i platta på mark : En analys av uppkomsten till fuktproblem

When constructing a building, a number of aspects must be harmonized in order for it to fulfill requirements ? a building must fulfill requirements such a load-bearing, conservation of energy and a good indoor environment by means of, among other things, moisture proofing .Moisture problems in buildings can affect health negatively. As we are increasingly staying in indoors, demands on a good indoor environment are higher.This work starts with examining moisture problems in slab-on-ground solutions, and then links the various scenarios to moisture problems in a concrete slab of a real building. The building with moisture problems is located in Årby by in Borlänge and moisture damage was found in the slab at an apartment adjoining wall.By reviewing literature written within the field of moisture problem, making hand calculations and modeling in the program Comsol Multiphysics, judgments are made to find explanations as to why the rise of moisture occurred in the building in Årby by.Generally, the following guidelines may be used to reduce the risk of moisture problems in slab-on-ground constructions:Drying of construction moisture before laying the floor material.Using draining layer beneath the slab, to prevent capillary suction.Using insulation under the slab, partly for comfort and to establish the temperature difference between the ground and the concrete slab.Avoid direct contact between the wood and concrete, due to degradation and fouling smells that normally occurs.If necessary, use additional vapor barrier.In addition to the above, there are various methods for moisture-proof and moisture-monitoring by design or by the method ByggaF suited for the entire construction process various events..

Kartläggning av spånprodukter vid Sävar såg

A change towards using more biofuels than fossil fuels is taking place in Sweden, and in many other parts of the world. This makes the use of fuel pellets increasingly popular, causing a greater demand for sawmill sawdust products. There is a trend towards the use of multiple types of shredders, instead of a single type in each sawmill. The purpose of the study was to characterize the different flows of saw particles that can be found at Sävar såg when cutting thick or thin wood with different cutting techniques. The saw particles size, shape, moisture content and heat value were analysed by the cutting stations: first cutting fast and slow, second cutting fast and slow, grading fast and slow and planning.

Effektiviseringsåtgärder i tryckluftsystemet hos Vattenfall Värme Uppsala

In this work an assessment of the compressed air system in the facilities of Vattenfall Heat Uppsala has been conducted. The facilities constitutes, among others, a combined heat and power plant, and two waste incineration plants. The compressed air is supplied primarily by seven rotary screw compressors and yearly electric energy consumption in these has been determined. Furthermore, the usage of compressed air has been mapped in order to find processes with energy savings potential. Several suggestions how to reduce the usage of compressed air have been presented, resulting in decreased need of electric energy and reduced CO2-emissions.The results show that total need of electric energy in the compressors, during a standard production year, amounts to 5.83 GWh.

Nedfästning av oljemåleri på puts.En fallstudie från salongen på Mostorps slott i Halland

This thesis, designed as a case study, is about complications concerning conservation of a decorative oil paint on lime plaster from the drawing-room in Mostorp castle sited in the county of Halland in south-west of Sweden. The building was built 1878-80 with an exterior of granite. The interior walls were made of clay bricks, lime mortar and lime plaster. The oil paint is applied to a layer of putty. The combination of different materials, which are organic and inorganic, affects the movement caused by internal and external stress.

Stöldskydd

To save energy it?s popular to build houses with low energy loss. In these houses the walls are keeping a lower temperature in the external side which leads to a higher relative humidity. In addition more material, such as wood studs, are used which means that there is more moisture to dry. More moisture in combination with higher relative humidity may pose a higher risk of microbial growth.

En marknadsundersökning om regelvirke : kvaliteter och kunduppfattningar

Today there is a widespread opinion that the woodmarket and the forest industry are dominated by a traditional way of thinking and not adapted to the customers of today; a lot of products are produced purely on routine. Also, there is a demand for improving the quality of sawn woodproducts. AB Karl Hedin wants to sort this out by increasingly adapt their products to the demands of the market, i.e. through introducing a short wallstud of standard length, "Hedinregeln". At tirst, the wallstud will be produced in lengths of 2,70 m and of guaranteed quality.

Nitrogen fixation among boreal feather mosses along a clear-cut chronosequence

The Swedish boreal forests are limited by nitrogen (N) availability. While biological N2 fixation by cyanobacteria hosted by pleurocarpous feather mosses are important sources of N input to natural boreal forest ecosystems, little is known about the patterns of N2 fixation in silvicultural systems. This study investigates the biological N2 fixation rates of two boreal feather moss species (Pleurozium schreberi and Hylocomium splendens) along a chronosequence from clear-cut to mature forest, as well as the vegetation characteristics along the chronosequence. Measurements and samples were collected from 32 forest sites that were classified into four age classes (clear-cut, pre-commercially thinned, thinned and mature forest). The sites were located near the city of Arvidsjaur in northern Sweden.

Skogsbrandens påverkan på död ved :

Fire is an important ecological factor, but its consumption of coarse woody debris, CWD, has hardly received any attention. In this study, I investigate the consumption in relation to the time of initial flame exposure and propensity for continued combustion of standing CWD of pine (Pinus sylvestris). Two types of CWD were studied. Firstly, wood that had been dead for one to ten years. Secondly, wood that had been dead for several decades. In the burning experiments, logs of approx.

Konstruktionslösningar och deformationer i tre Östgötska medeltida sockenkyrkor

The purpose with this report is to illuminate the construction solutions and the deformations that could exist in medieval parish stone churches. But also to increase the writers understanding how activity forces effect the construction of the churches. With help from literature and a practical study, containing three churches the writers have collected the material that the conclusions and discussions are built upon in this report. The construction of the churches consists of three parts, the wall, the roof and the vault. The construction solutions are similar in the churches disregard of the roof, where the roof trusses are different.

Undersökning av fasadskivor

The purpose of this report is to present some of the market's façade panels and to do a survey of Masonite façade panels and compare. Therefore I have looked closer on potential competitors and studied their assembly method and properties. I will also propose suggestions on installing Masonite panels and improvements to the current carrying system. The carrying system for façade panels in general. Various key people in various areas of the construction industry have been interviewed. People with a wide knowledge of theory and with real work experience have been my main focuses too implement this survey.

Uppfattningar om tryckved bland träbearbetande företag i Sverige :

The primary purpose of this study has been to investigate the Swedish timber industry?s perception of compression wood. A secondary aim has been to describe particular areas within the production process where compression wood is likely to cause problems. This study has mainly been carried out as a questionnaire. In order to connect the findings to current research, additional information has also been collected by means of a literature review. The questionnaire has been intended for sawmills and wood-manufacturing companies from various production classes and owner categories, as well as from different parts of the country.

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