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227 Uppsatser om Thermal cracks - Sida 9 av 16
Utveckling av hygienfunktioner i diskmaskiner : Desinfektion med ånga
This report is the result of a thesis work in Integrated Product Development, regarding hygienic features in dishwashers and especially disinfection by the use of steam.The thesis is performed at Electrolux Primary Development Dishcare in Stockholm and in collaboration with the Department of Machine Design at the Royal Institute of Technology.The targets of the thesis are to prove the advantages of a technology suitable to implement as a hygienic feature inside a dishwasher and to realize a functional prototype of a differentiated hygienic feature that does not exist on the market today.The process followed to perform the thesis is the process defined for Electrolux Primary Development.The technology chosen for development is disinfection by heating the water on the surface of the dishware, by the use of steam.A number of tests on how steam behaves when injected into the dishwasher tub have been performed, providing the results that have been taken in consideration when designing the prototype.The prototype consists of a pipe system provided with nozzles to eject the steam into the upper parts of the dishwasher. Tests of the final prototype show that thermal disinfection of water in a dedicated area of the tub can be reached within 9 minutes. The operation requires 0,17 liters of water and consumes 0.2kWh..
Hållbar design för en bättre värld - med hemlösa i fokus
The aim of this project is to examine the needs and problems that exists amongst homeless people and to develop a solution that will help them in their everyday life. Since the homeless are a relatively large vulnerable group i Sweden, their everyday lives could be made easier in many ways.A clear definition of the target group is put together to create a good starting point. What state and help orginazations do to help the homelss and the society?s view of the homeless is also relevant and has been documented. Four personal stories have been put together to desicribe cases of clear problems existing in everyday life.Several interesting problems has been defined from the research and acceptance in the communtiy, desire to be seen and heard and a lack of confidence were the main needs.
Granskning av svensk standard för dimensionering av stålfiberbetongkonstruktioner : Jämförelse av plattor enligt SS 812310 och SS-EN 1992
En svensk standard, SS 812310 ? Dimensionering av fiberbetongkonstruktioner, har nyligen tagits fram som skall säkerhetsställa kvalitén och underlätta dimensioneringen av stålfiberbetongkonstruktioner. Tidigare har det inte funnits en dimensioneringsstandard som täcker in området stålfiberbetong. Det har varit upp till enskilda konstruktörer att dimensionera utifrån metoder angivna ur ?Svenska Betongföreningens rapport nr 13?.
Transientanalys för Forsmark block 2 och 3 : Studie av hur val av driftpunkt och pumpreglering påverkar torrkokningsgränsvärdet
The dry out criterion (MCPR) has been calculated for the most limiting H2-events for Forsmarks unit 2 and 3, at operating points that are normally not analyzed before each cycle. The operating points that normally are regarded as the ones with the lowest margin to dry out are the ones where the thermal power is the highest at agiven recirculation flow. This report shows that this is not the case for Forsmark 3. MCPR-values at partial power operating points are higher for the limiting case inside rather than on the boundary of the region of operation. It is therefore recommended that the method for determining the dry out criterion for Forsmark 3 is revised to account for this effect.
Värmeisoleringsberäkningar av flerbostadshus : byggda 1996-2005
År 1987 trädde en ny byggnadslag i kraft, Plan- och bygglagen(PBL). I och med den nya lagen minskade kommunens och byggnadsnämndens kontroll av projekteringshandlingar och besiktningar ute på arbetsplatsen. Efter lagändringen beror den slutgiltiga kvaliteten på en byggnad i större utsträckning på byggherrens och entreprenörernas egenkontroll. P.g.a. olika intressekonflikter inom kommunen, och att det kan förekomma starka kopplingar mellan byggherre och entreprenör, är det inte alltid självklart att kommunens tillsyn vid nybyggnation gällande till exempel egenskapskrav på energihushållning och värmeisolering utförs tillfredsställande.Med ovanstående i åtanke undersökte vi fyra flerbostadshus, två i Värnamo kommun samt två i Kristianstad.
Studie av värmeflöden i befintligt bostadsbestånd : Utvärdering av energieffektiva besparingsåtgärder
The purpose of this master thesis is to investigate different types of measures for making buildings more energy efficient and to estimate their profitability. The calculations were performed with the building simulation program VIP+ and the evaluation of the profitability with the life cycle cost method. Furthermore, it was examined how losses in the distribution of secondary systems of district heating can be avoided. Options to replace district heating with a local district heating system based on bio-energy have been investigated. The possibilities of achieving more efficient thermal energy consumption and production for the chosen estate were also examined.The object of the study has been a residential estate with 133 detached houses in Uppsala, built in 1974.
Kalvhyddans utformning : påverkan på kalvens hälsa och komfort
This paper aims to, through a literature review, examine how to best design and adapt calf huts to meet the calf's physiological requirements and reduce the infection pressure for enteric and respiratory diseases. It illuminates how the calf relates to different temperatures and climate, which temperature control mechanisms it uses and its ability to perform these regulations, as well as providing a summary of the past decades´ research on the calf huts housing system. These two theory chapters, along with a concluding discussion, provide a better understanding of how to, especially in temperate climates, design the most suitable calf hut, which cater to the calf's both thermal comfort and physical health. The literature suggests that the calf's own temperature control works well to counteract the temperature outside the desired range, and that one of the most important factors rather is ventilation of a calf hut, which reduces moisture and pathogens. The conclusion of this paper is mainly that there is not an obvious way to place and construct a calf hutch and that most design principles contribute to both positive and negative effects simultaneously.
Krafter på rörsystem vid transient flöde : En jämförelse mellan RELAP5 och Fluent
At Forsmarks Kraftgrupp AB (FKA) forces on pipe systems due to transient flow are frequently calculated as a step to verify their structural integrity. In nuclear industries these forces are often calculated with a one dimensional thermal-hydraulic analysis-code called RELAP5. When calculations regarding more complex geometries are needed, the three dimensional code Fluent is often used. This code is highly time consuming and requires large computational power.This projects aim is to compare calculations of pressure, flow and forces carried out by RELAP5 and Fluent for an arbitrary pipe section during transient flow conditions. This has been accomplished by constructing a simple geometry for which a transient flow is simulated in both programs.
Effektiv lagerstyrning genom tillförlitlig prognostisering : Effective inventory control through reliable forecasting
This study was done regarding whether sealing or ventilation is the best solution to prevent moisture on cold attics. The authors of this report addressed the problem with moisture in attics when they started their cooperation with Peab.The methods included interviews with people, database research, and calculations of a project in Akersberga north of Stockholm. The conclusion is based on interviews and other information as they are analyzed in relation to the house of reference. The focus of this report is on problems with moisture in the attics known as cold attics.The background of the problem with moisture is that today?s slabs are usually insulated to save energy and that the attics nearly gives the climate as the outdoor climate.
Energikartläggning av biogasanläggningen, Kungsängens gård
The purpose of this thesis was to make an energy survey and quantify energy flows of individual unit operations associated with the biogas production in Uppsala Vatten och Avfall AB:s biogas plant, located at Kungsängens gård. Moreover, large consumers of energy would be identified and analyzed. The objective of this energy survey was to obtain a detailed understanding of the energy use in the biogas production.The energy survey was divided into two parts: electricity and heat. Each part was treated separately and with somewhat different approach. To estimate the electricity usage during the projcet the rated power of each selected unit operation was noted and multplied with thenmeasured time of usage.
Energikartläggning vid biogasanläggningen, Kungsängens gård
The purpose of this thesis was to make an energy survey and quantify energy flows of
individual unit operations associated with the biogas production in Uppsala Vatten och Avfall
AB:s biogas plant, located at Kungsängens gård. Moreover, large consumers of energy would
be identified and analyzed. The objective of this energy survey was to obtain a detailed
understanding of the energy use in the biogas production.
The energy survey was divided into two parts: electricity and heat. Each part was treated
separately and with somewhat different approach. To estimate the electricity usage during the
projcet the rated power of each selected unit operation was noted and multplied with the
measured time of usage.
Konstruktion av formkropp pa JAS 39 E/F Gripen
The aim of this work is to develop new conceptual designs for the fairings that are situated between the fin and the rear fuselage on the new version of the JAS 39 Gripen aircraft, called the Gripen E/F. The designs presented should show a profit in the form of lower weight. To achieve weight loss, the possibilities of using other construction materials other than those which are available at Saab today were studied. Therefore, a material survey was carried out in which the market for modern construction materials was studied to get an idea of today?s level of technology.
Tätning eller ventilering mot fukt på kalla vindsutrymmen
This study was done regarding whether sealing or ventilation is the best solution to prevent moisture on cold attics. The authors of this report addressed the problem with moisture in attics when they started their cooperation with Peab.The methods included interviews with people, database research, and calculations of a project in Akersberga north of Stockholm. The conclusion is based on interviews and other information as they are analyzed in relation to the house of reference. The focus of this report is on problems with moisture in the attics known as cold attics.The background of the problem with moisture is that today?s slabs are usually insulated to save energy and that the attics nearly gives the climate as the outdoor climate.
Konceptstudie av Waste Heat Recovery System på Tunga Fordon
In today?s fast growing and closely connected society, a reliable and energy efficient transportation system is more than ever desirable. Nowadays the significant part of the transportation sector?s energy demand is supplied by fossil fuels.Improving energy efficiency in combustion engines will result in reduction of fuel consumption and CO2 emissions. A modern internal combustion engine has an efficiency of 30-45 %, where the most energy loss occurs as result of heat losses in the exhaust and cooling systems.
Quantitative thermal perception thresholds, comparison between methods
Skin temperature is detected through signals in unmyelinated C-fibers and thin myelinated A?-fibers in the peripheral and central nervous system. Disorders in thin nerve fibres are important and not rare but difficult to diagnose by the most common neurophysiological methods. In this pilot study different methods for quantitative sensory testing, QST, were compared to give some ideas about which method could be the most efficient to use in order to point out injuries of the sensory system in clinical practice. The comparison was made between Békésy (separate warmand cold thresholds) and Marstock test (combined warm and cold thresholds).