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435 Uppsatser om Thermal fatigue - Sida 6 av 29
Comparative analysis of Thermal Barrier Coatings produced using Suspension and Solution Precursor Feedstock
The research work performed in this thesis has been carried out at the Production Tech-nology Centre where the Thermal Spray research group of University West has its work-shop and labs.This research work has been performed in collaboration with the International Advanced Research Centre for Powder Metallurgy and New Materials (ARCI), Hyderabad, India.First of all, I would like to express my sincere thanks and gratitude to my supervisors Dr. Nicolaie Markocsan and Dr. Nicholas Curry for their guidance, great support and valuable suggestions without which this work could not have been possible. I would also like to thanks Prof. Per Nylén for keeping faith in me and providing me an opportunity to work at PTC, which is a great place to perform research.
Beräkning av värmeenergiförluster i flerbostadshus genom analys av den totala fjärrvärmeenergianvändningen :
This thesis has been carried out on behalf of IV Produkt AB and intends to set an average ratio of thermal energy losses in apartment buildings that were built during the 1960-1990. This shall be derived by analyzing the total district energy consumption that has been divided into three parts: heat energy losses (the actual heating requirements), the heating of domestic hot water and heating energy consumption for the controlled ventilation.Three different residential areas that were built during the years 1962-1966 and one that was built in 1993 has been analyzed. All residential areas are located in Växjö urban and contains between four and six apartment buildings.The analyzed objects have a mechanical exhaust ventilation systems and district heating as the heating method. No own laboratory work or experiments have been done in this thesis, the calculations have been done on the basis of parameters from VEAB, interviews with property managers, and literature studies. By calculations, we have got a result that is reported in Chapter 6.
Lagring av kyla med horisontella markvärmeväxlare för kylning av koncepthus i Mellanöstern
Norconsult AB has developed a solarhousing concept, a house designed for the warm climate in the Middle East andwith large quantities of solar panels installed. The cooling system for the house was designed in an earlier report, the purpose of this thesis is to investigate the possibility of short and long term storage of thermal energy via an underground energy storage volume.Two different designs of the storage and three different filling materials have been integrated into a model to simulate different cases. The first design consisted of pipes installed in the ground, without insulation. The second design consisted of an insulated concrete box installed to prevent thermal energy from the surrounding soil to flow towards the lower temperature regions within the storage. The three different filling materials were dry saudi sand, water saturated saudi sand and the filling material used by the client for energy storage in Sweden.The results from the simulations show that neither of the designs, regardless of the filling material, managed to extract enough thermal energy from the house to the ground to uphold the demands of indoor climate.
Undersökning av förskolan Temmelburken certifierad enligt Miljöbyggnad : Termiskt klimat, energianvändning och höjning av certifieringsnivån
WSP building physics in Stockholm has certified the preschool Temmelburken in Bromma with the system of certification Miljöbyggnad. The rating of the building became BRONZE. In this thesis the preschool has been investigated with respect to the three areas: thermal climate, use of energy and improving of the level of certification. The thermal climate at the preschool has been investigated by a questionnaire survey and by measurements in order to do comparisons between the results from the two investigations as well as with the results of the simulations that WSP has done at the certification of the preschool. The differences between the results from the simulations and the questionnaire survey for winter as well as from the measurement performed with a comfort meter the 19th of March are concidered to be reasonably small since they give rise to the same rating according to Miljöbyggnad. Operational data for the use of energy for the preschool have been obtained in order to do comparisons with simulations performed by WSP and Svenska Besiktningar AB. The comparison shows that the simulated values for the specific use of energy are lower than what the real specific use of energy would be for the preschool, since just the operational data for the heat energy is higher than the simulated values. At the investigation of the possibility of improving the level of certification it was found that the rating of the preschool can be raised from BRONZE to SILVER by improving the ratings of the ?thermal climate summer? and the ?daylight?.
Optimering av OTEC-system
Ocean Thermal Energy Conversion, OTEC, is a sustainable energy conversion technology that is not yet commercialized. OTEC is a technology that utilizes the temperature difference in oceans between the warm surface water and the cold water at 1 000 m depth to run a Rankine Cycle. This technology can produce electricity and provide synergies like fresh water, air conditioning and aquaculture. A simulation program for three alternative OTEC systems has been created in order to decide which OTEC system is most profitable; closed, open or hybrid system. In this simulation a production cost analysis is performed in order to investigate and decide which one of the three systems that has the lowest production cost. The production cost analysis also analyzes if the profitability is affected by the size of the facility. After these analyzes, the most profitable of the three different OTEC-systems is expanded by an installation of solar collectors in order to see if the thermal efficiency is improved. The result shows that the most profitable system varies with the size of the facility.
Betydelsen av vila och återhämtning för personer med medelsvår KOL som upplever fatigue
Kroniskt Obstruktiv Lungsjukdom (KOL) är en komplex sjukdom med flera symtom som tillsammans påverkar livskvaliteten. Fatigue är ett vanligt men ofta outtalat symtom som påverkar individen i olika livssammanhang, känsloliv och på djupare existentiell nivå. Trots detta är det ovanligt att trötthet och behovet att vila tas upp som ett problem både av personen själv, närstående eller av sjukvården. Vila är ett av människans grundläggande behov och har betydelse för välbefinnandet. Syftet med studien är att beskriva betydelsen av vila och återhämtning i det dagliga livet hos personer med medelsvår KOL som upplever fatigue.
Kroniskt trötthetssyndrom : en diskursanalys av artiklar 1989-2006
The purpose with this work is to describe the language that is built around the chronic fatigue syndrome (CFS) in Sweden. Our questions are: What does the professional field look like; who writes, about what and for which kind of readers? How do they describe the expressions and the upcoming of CFS? For which reasons can CFS be considered as a medical diagnosis/illness? How can CFS be understood from a social perspective? Our theoretical starting point is a social constructive theory and also Karin Johannisson's theory about medicalization and Foucault?s theory about power. We have from a literature-exposition of Swedish articles from 1989 to 2006, done a social constructive discourse analysis with help from Laclau & Mouffe's discourse theory, and Fairclough's model of social practices. In our textual analysis we found three dominating discourses: A medical discourse, a social/cultural discourse and a general/popular discourse.
Hållfasthetsegenskaper i gjutjärn : tensile properties of cast iron
In the last few years people have become more and more aware of how humanity is affecting the climate. In the direction of reducing the greenhouse gases is to design engines with higher tensile properties and reduced weight, in order to achieve lower fuel consumption and cleaner fuel incineration in today's truck engines.In order to achieve these requirements it?s necessary to increase the combustion pressure in the engine. This requires higher tensile properties and high thermal conductivity of the engine material. The department of Component Technology at the University of Jönköping in collaboration with Volvo Powertrain AB, Scania CV AB and DAROS Piston Rings AB has been commissioned to develop this material and to find knowledge of material properties used in truck engines and piston rings used for marine applications.The purpose with this work is to analyze the tensile properties of a series of cast iron, cast under different metallurgical conditions.Four different series of cast irons have been analyzed from four points of view, carbon concentration, nodularity, amount inoculation and cooling rate.After the tensile test all specimen data was analyzed in a mathematic calculation program called Matlab 2006a.
Utredning av frekvensregleringens påverkan på mekanisk utrustning i en kaplanturbin
As a consequence of increasing wind power installations in the Nordic grid the last years, the need for regulating power has become larger. In the Nordic grid, regulating power is mainly provided by hydro power. One part of the regulating power is called frequency control, which ensures that the grid frequency is stable and close to 50 Hz.However, setting the turbine into frequency controlled operation may cause stress and wear of the components in the mechanical control system. Frequency controlling implies large and frequent servo forces and longer travelling distance of the sliding bearings in the Kaplan turbine.Based on one selected Kaplan turbine, Selsfors G1, measurements and MATLAB calculations have been performed in order to determine forces and movements of the linkage system. With these forces and movements as input, stresses and fatigue have been determined as well as sliding distances, bearing pressures and wear of bearings during a typical lifetime of 40 years.The results indicate that no severe wear exists on the bearings during 40 years of service.
Solenergi på Nya Karolinska Solna
In today?s society climate change has grown to one of the largest global issues. To reduce emissions of greenhouse gases, large changes of the energy system are required. An increasingly popular solution is investments in local production of renewable energy resources like wind, solar or geothermal power. The following report examines the possibility for implementing a solar power plant on the new hospital Nya Karolinska Solna. Two different technologies for extraction of solar energy has been studied, solar thermal collectors to meet the need of heating and solar cells to satisfy the need for electricity linked to operating the hospital building.
?Som en urvriden disktrasa?- Patienters upplevelser av cancerrelaterad fatigue
Fatigue är det vanligaste symtomet vid cancer och innebär onormal trötthet och utmattning. Symtomet påverkar människan både fysiskt, psykiskt och leder till minskad livskvalitet. I samband med cancer benämns symtomet som cancerrelaterad fatigue, CRF. Bristfällig medicinsk behandling mot CRF ställer större krav på sjuksköterskan att genom god omvårdnad lindra symtomet. God omvårdnad är bland annat att lindra lidande, vilket är en av sjuksköterskans primära arbetsuppgifter.
Trädgården som rehabilitering vid utmattningssyndrom
The aim of the study was to explore the methods used in horticultural therapy gardens in rehabilitating people suffering from fatigue syndrome. Nine horticultural therapy gardens were contacted of wich three chose to participate. Using case study as method e-mail interviews was carried out with the participants about their establishment and what kind of theories they based their methods upon. The material collected from the interviews was complemented with additional data from the establishments web pages and information pamphlets. Collected data was processed trough content analysis and then formed as background for the development of a program theory for horticultural therapy.
Inventering av värmelager för kraftvärmesystem
When a combined heat and power plant produces heat and power it often faces a deficit of heat load during the summer or other periods of time. This heat is often unnecessarily cooled away or the power production has to be reduced or shut off. If it is possible to store heat from periods with low heat demand to periods with high heat demand one can get many benefits. Among these benefits are: increased power production, decreased operation with partial load, uniformly distributed load.To be able to store heat in situations like this long-term thermal heat storages are needed. In this thesis five different types of stores are presented: rock cavern storage, tank storage, pit water storage, borehole storage and aquifer storage.
Inomhusklimat i skolor- En jämförelse mellan upplevt och uppmätt inomhusklimat
Students? performance in school is dependent on the indoor climate. This report studies four schools regarding air quality and thermal environment. A survey was made at the schools as well as measurements of carbon dioxide, dampness, thermal climate and, as an indicator for the furniture?s capability to collect dust, shelf factor and fleece factor.
Restspänningar i arc-förångade (Ti(1-x)Al(x))N ytskikt
This report is the written documentation of a project work carried out at the Division of Engineering Materials at Luleå University of Technology in cooperation with Seco Tools AB. The project deals with the analysis of residual stresses in Ti-Al-N thin film grown on WC/Co cutting inserts. The composition of Al varied from 0% up to 75%. Increasing the Al content in the Ti(1-x)Alx N compound improves the compressive residual stresses even after annealing of the material. The experiments have been performed in a high temperature x-ray diffractometer (HTXRD) where the interplanar atomic spacing was determined in-situ and subsequent converted into stresses.