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4906 Uppsatser om High-frequency - Sida 19 av 328
Valsningsteknik för extremt höghållfasta tunna stål
New high strength steels require improved cold rolling techniques. The aim of this degree project was to develop a new and money saving cold rolling technique to manufacture steel strip for saw blades. The work is based on earlier rolling experiments made with a high carbon steel grade at LuCoil Steel AB. The work also focused on the mill requirements to cold roll high strength steels. The results show that LuCoil?s existing cold rolling mill was actually designed for rolling low carbon steel.
Framtagning av förbättringsförslag för SNCR-system
The gas turbines in the Swedish secondary reserve are reaching the end of their technical lifetime, hence alternative solutions need to be considered. One of the solutions thought to have the greatest potential is the use of so called consumptionreduction. By entering contracts with large consumers, agreements are made to reduce consumption in the event of major disturbances in the power system and thus being used as a secondary reserve. This thesis investigates the feasibility of consumption reduction as part of the secondary reserve. This has been achieved by developing a requirement specification for the disturbance reserve and by studying the technical and economic potential for consumption reduction among a range of consumers.The technical potential for consumption reduction that fulfils the requirements for participating in the secondary reserve are on average 750 MW in SE 3 and 98 MW in SE 4.
Spelutveckling och lansering av applikation till Android
For several years Uppsala University together with several companies has been involved in a WISENET project aimed at improving railway transport security. By placing a sensor system near the wheels of each wagon, the temperature of the bearings can be measured and transmitted to a collector placed centrally on the wagon. This in turn transmits the collected data to RFID receivers placed intermittently along the railway.As the signals are transmitted wirelessly, problems may occur as the antennas get dirty or coated with ice and snow. To determine the effects of these coatings, several tests were performed examining the reflection coefficient S11, the impedance Z11 and the efficiency eta of an antenna, and how they varied when various coatings were placed over the antenna. Examined coatings were ice, snow and water to determine the effects of weather, and various metal-based coatings: powdered iron both pure and partially oxidized, and iron ore granules.
Optimering av sotningsfrekvens i biobränsleeldad CFB-panna : panna 5, Mälarenergi AB, Västerås
During the past 30 years the fuels for energy production in heating and power plants
have changed. Fossil fuels have decreased in usage whereas bio fuels in Sweden
have increased with 60% since the 1970's. Different fuels affects combustion and the
release of various substances and particles into the flue gas. This is caused by the
diverse components and chemical structures of fossil fuels and bio fuels. When the
flue gas leave the combustion chamber and enters the path to the chimney particles
in the gas are being transported out of the combustion chamber.
Självkänsla och motivation : En studie kring gymnasieelevers självkänsla och motivation inom ämnet matematik
The objective of this study was to bring further knowledge to the subject as to what influences students motivation and self-esteem. The study had focus on role that the teachers play in these aspects. The study was done by using both a qualitative and quantitative approach. The qualitative method was interviews based on six interviews with two teachers and four students from two different classes. The quantitative method was a questionnaire study that was done in both classes.
Elanslutning av fartyg i hamn : en studie om förutsättningar och konsekvenser för Köpings och Västerås hamn
The purpose of this thesis is to investigate the possibilities for shore side electricity in the ports of Västerås and Köping. A technical solution to connect the vessels to the local grid is suggested and the investigation is also aiming at an understanding of how the environment is affected by the use of shore side electricity. Furthermore, the costs of shore side electricity are considered.The maximum power demand of a vessel visiting the ports today is relatively small, but the ships visiting the ports in the future might have a larger power demand. The suggested dimension for the system is 5 MW and the result shows that the shore side electricity requires the power distribution to the ports to be expanded. The most useful solution in the ports is to connect the ships with 12 kV from a connection box in a pit at the quay.The investigation of the costs shows that it is cheaper for the ships to use electricity compared to the marine fuel.
Värdegrunden i skolan : En kritisk studie av innehållet och arbetet med skolans värdegrund i en senmodern kontext
The purpose of this study is to investigate the content and work processes regarding the values written in the curriculum for Swedish high schools and compare it with theories regarding the individualized society and political moralism. After the clarification of the content in the values of Swedish high schools and the work processes that are supposed to give students fundamental understanding about them, I analyze and compere it to the theories that are presented in the study. The main questions of the study are the following: What kinds of values are found in the curriculum for Swedish high schools? In general, how do Swedish high schools work with the written values when focus have gone from education and learning to instrumental knowledge, results, abilities and flexibility?The result showed that the content and work processes regarding the values in Swedish high schools are purely instrumental and moralistic. Due to the fact, that the individualized society and the neoliberal ideology do not require reflection and real understanding regarding the values.
Förskollärares syn på Kvalitet i Förskolan
My purpose with this work is to find out how it relates with pre-schoolteatchers view about a quality in comparasion to control document, Lpfö-98, and with factors pre-schoolteatchers consider effects quality in pre-school describe pre-schoolteatchers view on that high quality is in pre- school.The investigation has been done by quality interviews with five pre- schoolteatchers working in pre- school. The results show that they do not make a difference between what are high quality and the factors that affect the possibility of creating high quality. Most important is qualified and engaged educationalist in the pre- school who who shows a good attitude towards the children, and where development and learning is central. The most decisive to a pre- schools quality are the personell who work there. A conditon to achieve high quality in pre- school is a head who knows the pre- school activity and its curriculum, and who takes active part in the activity, invites to discussions and offers pertinent competence development.According to the leading document Lpfö-98 you will achieve high quality by offering children rear and care.
Krubbitning hos häst på olika strömaterial :
By limiting our horse?s freedom of movement, we restrict their opportunity to forage, which is one of their most important needs. If their need of forage is not fulfilled it can lead to frustration, which might manifest itself in abnormal behaviour, like the oral stereotypies for example crib-biting. It is a held belief that the horse swallows air while crib-biting, which they don?t, and that swallowed air causes colic, and the belief that other horses can copy the behaviour, leads to the use of many methods to prevent the behaviour.
Experimentell konstruktion av pickupsystem anpassat för trummor med hjälp av MATLAB
For several years Uppsala University together with several companies has been involved in a WISENET project aimed at improving railway transport security. By placing a sensor system near the wheels of each wagon, the temperature of the bearings can be measured and transmitted to a collector placed centrally on the wagon. This in turn transmits the collected data to RFID receivers placed intermittently along the railway.As the signals are transmitted wirelessly, problems may occur as the antennas get dirty or coated with ice and snow. To determine the effects of these coatings, several tests were performed examining the reflection coefficient S11, the impedance Z11 and the efficiency eta of an antenna, and how they varied when various coatings were placed over the antenna. Examined coatings were ice, snow and water to determine the effects of weather, and various metal-based coatings: powdered iron both pure and partially oxidized, and iron ore granules.
Omkonstruktion av testrigg för småskalig ångsmotor
The actual project presents the development of a testing rig for a steam engine. A short overviewabout the development of steam engines is presented, until arriving to the development of thepresent engine, which will require to be tested in different ways.The testing rig studied on this project (based on a Lanchester engine) will be used to testdifferent materials and layouts for the group Piston-Cylinder.The engine is a high performance steam power engine, which is going to have a highpower/dimensions ratio, what will lead to require high performance components and materials.An introduction to the testing rig is presented, and the entire design project is done in order toreplace the disappeared documentation of the current testing rig, built on the 1970?s. Also somemodifications done in the original testing rig are presented, as well as some detected problemsand their possible solutions..
Downside Risk - En studie av riskkompensation på den svenska aktiemarknaden
This paper investigates the compensation for risk in the context of the Swedish stock market with a special focus on downside risk. Using daily market data collected from the A-list of the Stockholm Stock Exchange between the years 1983 and 2005 the purpose is to answer the question whether Swedish investors are compensated for holding stocks with high downside risk, measured as downside beta. Using panel data analysis it is shown, in accordance with most previous evidence in international research, firstly that stocks with high beta values on average experience higher returns than stocks with low beta values, and secondly that stocks with high downside beta values experience higher returns than stocks with high beta values in general. On the other hand, cross-sectional regression methodology using a bivariate regression approach shows that downside beta does not explain excess returns very well. Instead, regression analysis suggest that high upside beta does a much better job in explaining excess return over this time period compared to downside beta.
Enklare korglutning
This project was led on behalf of Bombardier Transportation in Västerås, Sweden, incollaboration with KTH Stockholm and EPFL Lausanne. This project is connected to thedevelopment of a new and simplified tilt system for rail vehicles.Growing competition from other means of transportation has forced railway companiesthroughout the world to search for increased performances.Travelling time is the mostobvious performance indicator that may be improved by introducing high-speed trains.They require very large curve radii and long transitions curves not to impairridecomfort, another performance indicator. Building new tracks adapted to high speedtrains is very costly and can only be justified where the passenger base is large.Trains with the capability to tilt the carbodies inwards the curve is a more cost efficientalternative. The tilt inwards reduces thelateral force felt by the passengers allowing thetrain to pass curves at enhanced speed with maintained ride comfort but increases thefrequency ofmotion sickness.The benefits of tilting trains are improved speed capability in curves and enhancedpassengers comfort, but at higher buying and maintenance cost. As the conventionaltrains increase their speed in curves, the performance advantage of tilting trains isreduced while their prize is still kept significantly higher and constant.
Biblioteket i lärarutbildningen : intervjuer med 13 blivande samhällskunskapslärare
A qualitative study of high school student teachers' ideas about libraries and school libraries.Interviews have been conducted with future teachers about the library's role in their education,their views on library functions in high school and whether they as teachers will use theschool library. The results show that the students have had some instruction concerninghow to use the library as students, but very little as regards their future teaching. The professorsof teacher education focus on the fact that the library should be used in high schoolteaching, not how to use it. Despite this, the student teachers look very positively upon libraries.Libraries play an important part in their education and they are all sure that they asteachers will use the school library, which includes interacting with the librarian. To them, themost important school library function is to allow pupils to seek information..
Social media & marknadsföring
The gas turbines in the Swedish secondary reserve are reaching the end of their technical lifetime, hence alternative solutions need to be considered. One of the solutions thought to have the greatest potential is the use of so called consumptionreduction. By entering contracts with large consumers, agreements are made to reduce consumption in the event of major disturbances in the power system and thus being used as a secondary reserve. This thesis investigates the feasibility of consumption reduction as part of the secondary reserve. This has been achieved by developing a requirement specification for the disturbance reserve and by studying the technical and economic potential for consumption reduction among a range of consumers.The technical potential for consumption reduction that fulfils the requirements for participating in the secondary reserve are on average 750 MW in SE 3 and 98 MW in SE 4.