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858 Uppsatser om Coefficient of heat transmission - Sida 17 av 58

Konstruktion av värmespridare med grafit för flygelektronik

This master thesis was carried out for Saab Avitronics, a business unit of Saab ABactive in electronic systems for military aircrafts. Reliability and weight are of crucialimportance in this environment. To improve reliability and lower the weight graphitemay be used for electronics cooling. Graphite is an anisotropic material and hasthereof high thermal conductivity in two directions (in-plane) and a relatively lowconductivity in the third direction (through thickness).The purpose of this thesis was to investigate if graphite is an adequate thermalconductor to use in PCB carriers. The carriers support and cool the PCB by divertingthe heat dissipation from the PCB components to the edge.

Ljudisolering - Teknisk felsökning och kvalitetssäkring av lätta bygg-system

By using industrialized building, pre-installed modules can be delivered to the construction site where they are easily mounted. This method has many advantages compared to on-site manufacturing, for example, the precision during the production process should be much higher than building each wall and floor on site. Furthermore, the quick erection procedure when using prefabricated elements and the possibility to use weather protection has the advantage of not being dependent on weather conditions, and many other factors.Masonite Beams AB is a Swedish company (a member of the Norwegian company, Byggma ASA) with a relatively new technology using light weight beams as bearing elements in the walls and a certain stiff board lamella slap which is mounted on the top of the floor structure creating an integrated stiff beam / board floor structure. The elements are flat which make it much easier to transport the elements from the factory to the building site where the building parts are easily mounted with special mounting stud.One of the main drawbacks of lightweight structure is the sound transmission. The main topic is low frequency annoyance, however the complex structural elements and their mutual sensitive connections other acoustical problems might appear.

Tylö : Sauna Lighting

Tylö AB is the leading manufactor of sauna cabins in Europe, but there is a lackof a sauna lightning produced by Tylö. The project of developing a new saunalightning series was assigned two students at the developmentengineeringprogram at Halmstad University. The main problem with lightning in the saunais the heat and security aspect. The selection fell on LED technology as thelightning source, thanks to its small measures and low heat emission.The work of constructing of a lightning armature which the capability of coolingdown the LED lightning was carried out during autumn ?06 and spring ?07.

Tylö: Sauna Lighting

Tylö AB is the leading manufactor of sauna cabins in Europe, but there is a lack of a sauna lightning produced by Tylö. The project of developing a new sauna lightning series was assigned two students at the developmentengineering program at Halmstad University. The main problem with lightning in the sauna is the heat and security aspect. The selection fell on LED technology as the lightning source, thanks to its small measures and low heat emission. The work of constructing of a lightning armature which the capability of cooling down the LED lightning was carried out during autumn ?06 and spring ?07.

Energiberäkningar för passivhus

AbstractClimate and environmental issues are of paramount importance. Researchers agreethat we must all contribute to a reduction of gases that contribute to climatechange. Energy consumption must decrease within all sectors and the promotionof renewable sources of energy must be introduced.Each sector should aspire to decrease its energy consumption. Energyconsumption is strongly linked to waste gases that contribute to climate change.Passive houses are a part of the construction industry's methods to attain energyconservation.Passive houses are derived from low energy houses and super insulated houses. Apassive house is intended to obtain heat from the inhabitants and through theiractivities.

Fra?n passivhus till NNE-hus : va?gen till ha?llbar utveckling

sustainable development by reducing the energy use by EU:s directive of energy efficiency and the UN Convention. The second purpose is to present the technical solutions regarding ventilation and heating system that is being used in passive houses. This was done using 8 passive houses, 4 germany and 4 swedish passive houses. Even the international and Swedish system requirements for passive houses have been addressed in this project. The goal was also to explain how and why the mechanical system in passive houses has developed to the technology used today.

Uppvämningssystem med biobränsle : en fallstudie på Malmviks gård

The use of bio fuel is increasing every year. Nowadays you will find different alternatives to oil and electricity heating system. In this essay I have examined what the economic conditions are to invest in a bio fuel furnace. I have chosen to assume from a specific farm and do a case study on this farm. Malmvik farm is located just outside of Stockholm.

Economizer i bostadsvärmepumpar

I takt med stigande energipriser finner fler och fler det lönsamt att installera värmepump för att reducera sitt energibehov. Värmepumpar har dock svårigheter att tillgodose värmebehovet när utomhustemperaturen sjunker under -10°C. Detta problem kan minskas med så kallade economizerkopplingar, denna rapport jämför de båda economizersystemen flash tank cycle (FTC) och internal heat exchanger cycle (IHXC). Eftersom det har visat sig att vinsterna med economizerkopplingar är som störst då temperaturlyftet är stort är det mest intressant att jämföra dem i luft/vatten värmepumpar. Detta på grund av att övriga applikationer som berg-, jord- eller luft/luft-värmepumpar inte utsätts för samma stora temperaturvariation då utetemperaturen faller.

Inverkan av foders växtöstrogener på fysiologiska processer hos produktions- och sällskapsdjur

Phytoestrogens are secondary metabolites produced by plants. Among the plants that make phytoestrogens are soya, red clover and some types of grass. The name phytoestrogen is a collective term for compounds such as genistein, daidzein, biochanin A and formononetin. These compounds are similar to oestradiol-17? in their chemical structure.

Alternativa byggsystem för att minska transmissionsförlusterna på miljonprogrammets byggnader

The purpose with this project is to explore and verify three renovating systems for Miljonprogrammet (common expression forbuildings constructed during the years 1965-1975 when over a million houses where built in Sweden) to take measure to thelargely transmission losses of these buildings. Many of the buildings from this period have similar constructions and thereforethe same techniques can be used to renovate several of them. This project only considers the climate scale, although thereare many more factors to concern for to efficient the buildings of Miljonprogrammet.This thesis presents examples of renovations carried out using two of the three renovation systems.The essay presents a reference house of choice on which we apply the three systems and calculate the new U-values,consumption of energy and the investment costs. The new U-values the building is given is matched to the values ofrecommendation for passive houses. Our reference house is a two story apartment building, located in the village ofLammhult, with brick facades at the ends and plaster at the long sides.

Småskalig säsongslagring av solenergi för uppvärmning av bostäder : Simulering av lagerutformning och konsekvensen av adderade uppvärmningsbehov motsvarande en pool och ett atrium

The sun is a huge energy source with great potential of providing energy to the heating of homes and other buildings in an environmentally sustainable manner. In order to provide buildings with energy from the sun it is necessary to transfer the energy supply over time to when the demand arises. By storing the heat in a seasonal storage, solar energy from the summer can be used in the winter when the demand for heating is greatest.Today's existing plants are mainly in Europe and particularly in Germany. These facilities are designed to supply heat demands greater than 400 MWh and covers about 40-50 % of this need which consists of energy for space heating and domestic hot water. How much of the heat demand that is covered, the solar fraction, is partly due to losses from the storage which in turn is connected to the surface area of the storage.

Fjärrstyrd undervattensfarkost

Two elementary schools are now being built in Gråbo (in the municipality of Lerum),Röselidsskolan and Ljungviksskolan, which are both designed with solar thermalcollectors for the schools domestic water heating. During the summer while thelargest amount of solar heat can be generated, the activity hence the domestic wateruse in the schools are heavily reduced. Both schools are connected to the local districtheating system which makes it possible to use the solar collectors to deliver heat tothe district heating.The purpose of this thesis is to evaluate the two systems mentioned above and todetermine which system is more suitable to apply on a school. The building whichconditions were used for this evaluation is Röselidsskolan.A solar heating plant of each system type was dimensioned from the expected andknown conditions of the building. The purpose with the dimensioning was to makethe solar plants replace the ordinary energy source as much as possible.

Optimering av B-stolpe

Two elementary schools are now being built in Gråbo (in the municipality of Lerum),Röselidsskolan and Ljungviksskolan, which are both designed with solar thermalcollectors for the schools domestic water heating. During the summer while thelargest amount of solar heat can be generated, the activity hence the domestic wateruse in the schools are heavily reduced. Both schools are connected to the local districtheating system which makes it possible to use the solar collectors to deliver heat tothe district heating.The purpose of this thesis is to evaluate the two systems mentioned above and todetermine which system is more suitable to apply on a school. The building whichconditions were used for this evaluation is Röselidsskolan.A solar heating plant of each system type was dimensioned from the expected andknown conditions of the building. The purpose with the dimensioning was to makethe solar plants replace the ordinary energy source as much as possible.

Kan detektorer förebygga tågurspårning?

Two elementary schools are now being built in Gråbo (in the municipality of Lerum),Röselidsskolan and Ljungviksskolan, which are both designed with solar thermalcollectors for the schools domestic water heating. During the summer while thelargest amount of solar heat can be generated, the activity hence the domestic wateruse in the schools are heavily reduced. Both schools are connected to the local districtheating system which makes it possible to use the solar collectors to deliver heat tothe district heating.The purpose of this thesis is to evaluate the two systems mentioned above and todetermine which system is more suitable to apply on a school. The building whichconditions were used for this evaluation is Röselidsskolan.A solar heating plant of each system type was dimensioned from the expected andknown conditions of the building. The purpose with the dimensioning was to makethe solar plants replace the ordinary energy source as much as possible.

Analys av bostadsrättspriset i Stockholms innerstad : En multipel linjär regression

In this study a multiple linear regression was carried out in the interest of analysing a number of variables effect on the final prices of apartments in Stockholm?s inner districts. The result may be employed to predict and observe percentage changes on the final price of apartments in Stockholm in the future. Five models were constructed after which they were analysed and compared. The construction of these models were supported by data from the real estate agency Erik Olsson.

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