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82 Uppsatser om Humidity - Sida 3 av 6
Trä och fukt ? Mätmetoder för fuktrelaterade dimensionsförändringar hos trä och deras användbarhet, med två fallstudier inom konservering
This thesis deals with different methods for measuring moisture-related dimensional changes ofwood. Typically relative Humidity is measured to determine if the ambient climate around anobject is harmful to it or not. Values between 40 to 65% RH are recommended for hygroscopicmaterials. To know how a wooden object actually reacts to changes in the surroundingenvironment requires methods that involve the object itself. Because of the wood anisotropy,differences in wood structure, finishes and other restraints, it is not always possible to predict themovements.This paper addresses various measurement methods, primarily methods that have been testedin the field of conservation, with examples of their use.
Uppfyller BIM förväntningarna som arbetsmetod för broprojekt?
The purpose of this work is to design and construct a device able to measure the mechanical attrition of oxygen carrier particles. Those particles are used in chemical looping combustion and in the present situation there is a lack of knowledge in how the attrition process work and in which extension. To find already tested solutions trying to answering this problem a literature study wascarried out and the best solution found was the so called Grace-Davison Jet-Cup method. This method is supposed to emulate the attrition caused by a cyclone separator and its advantages are that it is possible to use small test amounts, 5-10 g, and a thirty minutes long test will be enough to acquire useable results. An device was designed based on the Jet-Cup method with some slight modifications.
Status och hotbild för den oceaniska laven broktagel Bryoria bicolor i sydvästsverige :
Horse-hair lichen Bryoria bicolor is a red-listed lichen species in the category Vulnerable. It is an oceanic lichen and it is often found on boulders and cliffs in a semi-open environment with a high Humidity in the agricultural landscape. The species can also be found as an epiphyte on trees, mostly in boreal forests in the provinces of Dalarna, Härjedalen and Jämtland. In the agricultural landscape, there has been indications on that B. bicolor show a decline, and this studie aimed at examining the extent and causes of this decline.
Konstruktion av anordning för att undersöka förslitning av syrebärarpartiklar för kemcyklisk förbränning
The purpose of this work is to design and construct a device able to measure the mechanical attrition of oxygen carrier particles. Those particles are used in chemical looping combustion and in the present situation there is a lack of knowledge in how the attrition process work and in which extension. To find already tested solutions trying to answering this problem a literature study wascarried out and the best solution found was the so called Grace-Davison Jet-Cup method. This method is supposed to emulate the attrition caused by a cyclone separator and its advantages are that it is possible to use small test amounts, 5-10 g, and a thirty minutes long test will be enough to acquire useable results. An device was designed based on the Jet-Cup method with some slight modifications.
Teoretisk och experimentell utvärdering av Lättelement AB:s takinfästning
Lattelement AB in Ornskoldsvik is one of the leading companies in Sweden in composite elements in walls, floors and roofs in particular. The company supplies elements to buildings located with a wide geographical variation, which means that the products are subjected to very different climate with regard to snow, wind and Humidity. This places high demands and requires the elements to withstand large variable loads.The elements are made of lightweight beams with flanges of structural timber and beam webs made of OSB. These are bound together by nogging pieces with the same kind of structure. On top of the beams a nailed and glued plywood is added to absorb compressive forces and on the underside of the element a sheet of steel is added for tensile absorption.These elements are then attached to the building framework in different ways depending on the particular element height, loads and the structual supporting material of the frame work.
Produktivitet vid stubbskörd :
Stump harvest could be found in the late 1970?s and the early 1980?s. And now when the prices on energy are high it has become an interesting topic again. This work has been conducted within Holmen Skog?s stump harvest testing in Norrköping.
Vinterförvaring av Pelargonium x hortorum :
There are many different recommendations on how to keep pelargoniums over winter, but most of the recommendations suggest ?the higher the temperature, the more light and water the pelargonium needs?.
The purpose with this paper is to try to explain the best and the worst results that are achieved with different storage alternatives of zonal pelargoniums. The results are based on an orientating investigation carried out in January-February, and a questionnaire that members of the Swedish Pelargonium Society answered to.
Both the orientating investigation and the questionnaire showed that zonal pelargoniums are best stored light and cold but frost free. They should be irrigated according to their needs which is when the soil is dry, about every second to third week. Zonal pelargoniums are very resistant to drought and can survive without water for at least 44 days, both when kept under light and cold as well as under light and warm.
Bakterietillväxt i strömedel till mjölkkor
The resting area is the most important place in the barn for the dairy cow, sometimes called the heart of the free stall system. Inadequate design of the lying area, and lack of or poor quality of bedding materials may reduce the hygiene of the stall. Poor management regarding the cleanliness of the resting area may lead to poor animal hygiene and increased bacterial growth. This in turn will lead to increased risk for environmental mastitis as well as impairing milk quality through contamination with spores.
In this literature study the most commonly used bedding materials; straw, sawdust, wood shavings, clean sand, recycled sand, peat and recycled manure solids, are compared to one another with regards to their ability to resist bacterial growth. Effects of adding hydrated lime to bedding materials have also been studied.
Most bacteria need Humidity and prefer a quite high water activity to be able to grow.
Hussvamp : Skadeverkan och tänkbar ökning i Kronobergs län
Serpula lacrymans infestation has become an increasingly common problem, and is usually perceived as a tip of an iceberg.During the 21st century there has been a perceived increase of damage caused by serpula lacrymans, at AB Mats Fransson Saneringstjänst ? Anticimex in the county of Kronoberg. A similar increase has also been noted by employees at the offices in Kalmar, Karlstad, Piteå, Stockholm, Malmö, Söderhamn, Halmstad and Visby.The methods used to collect data for the project has been interviews with a number, for the project, relevant key persons, such as analysis engineers at Trygghansa and Anticimex, as well as personnel at the botanical institution at Gothenburg University and the Botaniska Analysgruppen in Gothenburg, further statistics from SMHI and analyses of reported instances of infestations have been used.The majority of the people interviewed believe that the increase is caused by renovations of old houses, higher precipitation during the summer months, as well as a moister climate and warmer winters. The latter can also be gleaned from statistics from SMHI concerning temperature, precipitation, and relative Humidity.Analysed damage reports show that the most common cause for the infestation is ground moisture, even when combined wooden materials.Older houses that where built around 1900 are the ones most frequently infested with serpula lacrymans. The part of the building most frequently infested is the foundation, where cellars and suspended foundation are the most common types to be infested.
Fuktsäkringsarbete i ett byggprojekt : ? En undersökning om hur byggprocessens aktörer arbetar för att uppnå samhällskraven
Lagen säger att man inte får uppföra byggnader så att det riskerar människors hälsa. Trots detta uppförs byggnader så att ohälsa uppstår för de boende. Arbetet behandlar hur man i ett byggprojekt arbetar med fuktsäkring. Syftet är att undersöka hur man i projektet arbetar med att fuktsäkra byggnaderna. Målet är att lyfta fram var i processen det finns risker när det gäller fuktsäkring, och även ge förslag till förbättringar av arbetet med fuktsäkringen.
Integrerad arbetsprocess mellan projektör och konstruktör, För effektiv och kvalitetssäker projektering med Tekla Structures och SAP2000
The purpose of this work is to design and construct a device able to measure the mechanical attrition of oxygen carrier particles. Those particles are used in chemical looping combustion and in the present situation there is a lack of knowledge in how the attrition process work and in which extension. To find already tested solutions trying to answering this problem a literature study wascarried out and the best solution found was the so called Grace-Davison Jet-Cup method. This method is supposed to emulate the attrition caused by a cyclone separator and its advantages are that it is possible to use small test amounts, 5-10 g, and a thirty minutes long test will be enough to acquire useable results. An device was designed based on the Jet-Cup method with some slight modifications.
New Generation Surface treatment for tools : A preliminary study
The surface finishing technique called black oxidation is currently being used on thetool holders made of low alloyed tool steel produced by Sandvik Coromant. Blackoxidation isn?t considered a sufficient technique because it doesn?t make the toolholders look like the quality products that they actually are. The reasoning behind thisis that the tool holders can show signs of corrosion after prolonged storing times orin countries with high Humidity and temperature. The corrosion doesn?t decrease thetool holders performance, but the customers might believe otherwise.
Säsongsvis avverkning : det operativa traktvalets påverkan på den säsongsmässiga uthålligheten i ett bolagsdistrikts traktbank
Due to soft grounds in combination with seasonal variation in soil Humidity, there is a lack of stands that are possible to cut during spring and autumn in some geographical regions. For Holmen Skog this sometimes means that a large proportion of the contracted private forest is cut during the winter when the ground is frozen. One consequence of this is that the proportion of winter stands in the stand bank of own forest increases while spring and autumn stands becomes a scarcity. This in combination with milder winters, especially when there is a long period of reduced bearing capacity in spring or autumn, means that the situation rapidly can become critical.
The overall goal with this study was to generate basic data for decision support in the work to achieve a sustainable distribution between own forest and contracted private forest in the stand bank.
The study took place at Holmen Skog, district of Umeå, during autumn 2007 and was based on interviews and an analysis of harvest planning and delivery data.
The study showed that there is a problem with how the cutting is distributed between own and contracted private forest during the year and that it foremost is the proportion of winter thinning of own forest that has increased in the stand bank.
Djupströbädd -bra för miljö och djur?
Deep litter is a system for animals kept in separate stalls, loafing and bedding in wind shelters. The litter can consist of different bedding, like straw and peat. The system is allowed to build over and to ensure optimal proportions it is necessary to add new straw regularly and to have good conditions. Important conditions are aerobic state, Humidity, amount of organic substance and acceptable temperatures in the litter. The micro organisms are depending on temperature for their living conditions and to get the bottom layer in the litter to start burning.
Marknadsundersökning för en fuktsensor med RFID-teknik
Fukt i byggnader är svårt att upptäcka och är ett vanligt problem i dag.Att i ett tidigt skede kunna se hur fuktigt det är kan bespara dyrakostnader. En ny produkt som företaget Sensible Solutions har tagitfram är en fuktsensor som kan placeras innanför väggar i till exempelbadrum. Fuktsensorn består av två RFID-taggar där en av taggarna äromsluten i ett fuktabsorberande material. När det fuktabsorberandematerialet drar åt sig fukt kommer den taggen bli svårare att läsa av,vilket indikerar att fukt förekommer. Avläsningen av fuktsensorn skergenom en handhållen RFID-läsare.