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183 Uppsatser om Moisture rearrangement - Sida 3 av 13
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.
Jämförelse av stenull- och polyuretanisolering : Brand- och fuktegenskaper i passivhuskonstruktion
This report compares two different types of insulation with regards to fire and moisture. The materials were tested for the company Fiskarhedenvillan AB, for a wall and a roof construction that the company currently uses in the establishment of Sweden's first certified passive house for international standards.Their current material, Rockwool, is compared to a relatively new material on the Swedish market called SEALECTION Agribalance sold by the company ISO Green AB. The material is a type of polyurethane insulation. This insulation material would result in a more efficient execution of the construction as it provides waterproofing and is applied more easily than Rockwool. From a fire standpoint, literature studies and discussions with fire experts led to results.
Utvärdering av befintliga passivhus : En byggnadsfysikalisk bedömning och mätningar om temperatur, och fukt analys på ytterväggarna
Energy price are on the way up to a high level that will not diminish in the future make us to focus more on the sustainable development for a better solution of residential houses. Passive house or low energy housing are one of the solution to make residential more environment friendly, in same time it´s a financial security using less energy, and saving money. The last 10 years in Germany and all around Europe the concept of passive house been developed, and people aim to know more about these concept that leading the market more attractive for passive houses. A passive house is a well designed building highly insulated and air tight with mechanical ventilated system for the whole building envelope that minimizes the use of energy for heating [1].The housing company Mimer has chosen to invest in low energy consumption in every new housing project. These future plan projects are decided to use less than 75 kwh per square meter annually in purchased energy [2].This thesis is about new constructed passive houses, and focuses on the evaluations of the temperature, and moisture condition for attic, external walls and joist.
Termisk analys av kompakta jordvärmesystem - Sensitivitetsanalys och korrektions faktorer baserat på fältmätningar i referensanläggningar i Östergötland
Chapter 1 defines the aim of the project and gives a general orientation about ground heat extractors. In chapter 2 physical processes that could be expected to be involved in the heat transport around a ground heat exchanger are discussed. It is shown from a literature study what amount of moisture transport due to thermal gradients there could be expected in a ground heat exchanger. The conclusion is drawn that the moisture gradient (Sr) is of same magnitude as the driving temperature gradient (°C). At the expected amount of increased moisture around the pipes the moisture transport could be considered to have a little effect on the brine temperature.
Pelletering av tallspån : grundläggande studier
Wood pellets are an upgraded product of residuals from several wood processing industries, for example saw mills and pulp industries. The pellets are produced by pressing the milled and dried sawdust to cylindrical units with a higher density than the initial raw material. Pellets have great benefits compared to the raw material: high energy per volume, good transport and storage properties and homogeneity.
Several parameters collaborate in the whole process, which makes it complex. Wood is a heterogeneous material, chemically and structurally dependent on wood parts, habitat and storage procedures.
Fuktskydd och planering i byggprojekt ? Erfarenheter från Eolshäll
When the Eolshällproject was completed for the first time, a great deal of moisturedamage was discovered. Therefore the structure completion was removed andreinstalled. The project was originally planned to cost a total of 126 million SEK, but thefinal costs landed on 271 million SEK. What caused this failure? Were the designs poor,was the technology used too advanced, or was the project not managed properly?Based on the Eolshällproject, theses will be presented about what may have caused themoisture damage.
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.
Energihushållning och varsamhet för äldre byggnader : Chefsbostaden i Strömsholm, ett timmerhus från 1900-talets början
This report is the result of a degree project in building engineering, at an advanced level. The project evaluated a building from a technical and historical point of view, and focused on its energy consumption, particularly the energy used for heating. The building in question was a small apartment building in Strömsholm, Sweden. It was made in 1902, from vertical logs, a not so common form of the traditional log house. The goal of the project was to evaluate if the energy consumption could be reduced in accordance with building preservation regulations, that is without damaging any of the building?s cultural or historical values.The building was surveyed with the help of archive and literature studies, interviews and inspections.
Cassava as an additive in biomass fuel pellet production :
In this study, the effects of using fine milled cassava stems as an additive in biofuel pellet production was compared to the effects of refined starch addition. The bulk biomass fuel raw material, to which the additive was added, was a blend of spruce and pine sawdust. An experimental design in the factors cassava/starch content, moisture content and material temperature was used. Measured responses were pellet bulk density, pellet durability, amount of fines, pelletizer motor current, pellet temperature, die temperature and CV for pelletizer motor current (a measure of process stability). Each response was modeled by multiple linear regression (MLR).
Teknik för egen foderberedning :
There is an uncertainty in the market for grain forcing the meat/milk producers to review alternative feeds to a larger extent, in order to get control over the feed costs. This has led to that the meat/milk producers need to have a good knowledge regarding how the different feeds influences the animals and which technical equipment to use for handling. For those that produce their own feedmix, there is a need to put interest in new crops and their characteristics to be able to get the knowledge of what is required for their own production. It is beneficial to keep an open dialogue with advisors to be updated in new crops and new technology for feeding.
When mixing feed at farm level, the legislation is not very clear since it the target group is large scale mixing plants. We have brought up the most important rules and regulations from the EU parliament Council as well as the ones from the Swedish Board of Agriculture (SJV), regarding feed mixing on farm and factory level.
We have studied beans and pea at two different moisture levels, in order to evaluate how the moisture level affects the distribution of particles when milling with a plaitmill and a hammermill.
Utveckling av en HBV/PULS-model med sammanfogade markfuktighets- och responsrutiner
Soil properties affect the chemical composition of soil water. When studying transport of chemical substances through a basin, it is therefore important to know from which soil layer the main part of the runoff is generated. The aim of this study is to develop an HBV/PULSE model with merged soil moisture and response routines, which generates good approximations of groundwater levels. It should be possible to extend the model to simulate transport of substances and take into account which soil layer the groundwater level is currently in. The hydrological version of HBV/PULSE is used since there is no need to account for pH or alcalinity at this stage.
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).
Upprättande av mall för fuktsäkerhetsbeskrivning : Genom granskning av projekt ur fuktsäkerhetssynpunkt
During the 1990?s a large number of building projects were revealed where lack of moistsafety precautions during the construction process had led to extensive moisture damage. Alsoresent implemented studies have shown that the problems with moisture damages have ratherincreased than decreased during the past few years. Moist is considered to be one of the mainfactors to cause unhealth due to deficiencies in the indoor-environment and does also causeunnecessary expenses and a reduction of the confidence in the construction industry.In this Bachelor of Science thesis three projects have been reviewed to examine how moistsafetyhas been observed during the construction process. Main focus has been to identify thebuilding components that are the most exposed to moist, and to examine how they have beentaken into account during the period of design and construction.
Utvärdering av ett silotorksystem för spannmål utrustat med omrörare :
The aim of this study was to evaluate the stir drying method, for drying of grain during Swedish conditions. The evaluation was done during the harvest year 2004, on four farms with stir driers. The driers were evaluated for their energy consumption, design, stirring effectiveness and how much time the farmer has to spend on every tonne of grain. A comparison was also done with conventional Swedish high temperature driers. Totaly six batches of grain from stir driers were examined, mostly winter wheat, but also barley and wheat.
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.