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4952 Uppsatser om High temperature electronics - Sida 21 av 331
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..
Design av PID-regulator baserad på kommersiell processormodul
The idea to develop a platform for a PID-controller came from the need to control the temperature in an espresso machine in a more exact way than a thermostat could perform. In discussions with Syntronic AB the idea developed into PID-control for industrial use. Syntronic AB suggested that the platform should be based on a commercially available processor module to shorten the development time. The suggestion included the use of the microcomputer Raspberry Pi, which supports USB, HDMI, memory card and Ethernet.The work began with establishing a schedule for the 10 weeks of the projects duration, and after that a system specification listing all functions, implementation and limitations was made. When the foundation of the system specification was done, a preliminary system design took shape.Because of the Raspberry Pi´s lack of Analog-to-Digital converter, a circuit board containing Wheatstone bridges, differential amplifiers and a two channel Analog-to-Digital converter was fabricated.
Torkning av vallfrö :
In Sweden, grass is the single largest crop grown. Nearly 1 000 000 Ha grows on the
fields, this is primarily used as feed for livestock. To get a good seed, you need to
handle the crop carefully from planting to delivery. The part that I have been
interested in, is how to dry the harvested seed with out destroying the growth in the
small seed. This is very easily done if you aren?t careful during the drying period.
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.
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..
Majsensilage i Sverige
Maize for silage has been used as fodder in different parts of the world for a long time and has recently become more common also in Sweden. Our cold climate has been a problem as maize is very sensitive to low temperatures and frost. With new varieties and better techniques for cultivation it is now possible to grow maize in the southern and middle parts of Sweden. As for the north of Sweden the length of the cultivation season is a limiting factor as there are too few days with temperatures of over +10 ºC. Maize is well suited for silage making but oxygen-free conditions are required.
En undersökning av tre olika behandlingsmedels effekt på vegetabiliskt garvat läder för bokband
Title in original language: En undersökning av tre olika behandlingsmedels effekt påvegetabiliskt garvat läder för bokbandLanguage of text: SwedishNumber of pages: 32.
Demographic Surveillance System Implementation - Low-level structures of the PDA - PC/PDA communication
Demographic Surveillance System Implementation- Low-level structures of the PDA- PC/PDA communicationThis thesis report describes the continuing work to develop a tool for demographic research at CIDS (Centro de Investigación en Demografía y Salud Universidad Nacional Autónoma de Nicaragua), UNAN, Leon/Nicaragua.The report is divided into four parts:? Revision of the existing database as a result of newly found requierments? Implementation of the low-level design on the PDA? Communication between the PC and the PDA? A mid-storage database on the client-PC.
Gravar i stenskepp : Osteologisk analys av brända och obrända ben från skeppssättningar på Gotland
In this study bone material from six stone ship settings and a total of seven deposits of bones from two sites on the island of Gotland have been analyzed. Four ship settings from the burial site at Gålrum in Alskog parish and two from Tängelgårda in Lärbro parish. The ships contained both cremated remains and inhumations. Human remains were identified in five of the analyzed ship settings and a minimum of six individuals was identified in total. Animals were found in three of the ship settings, where one of them contained only the burned remains of a dog. Two of the ships contained inhumations, one in Gålrum and one in Tängelgårda.
Ett extra år i grundskolan
The basic idea behind an extra year in school was to offer students who have not read nine years in Swedish primary school an opportunity to prepare themselves to pass a high school. This first group that went an extra year in school consisted of eleven students who completed their studies and went on to high school. During the time the group expanded, the school received students from various schools in the same municipality. During the follow-up of these groups could be noted that there were many students who registered, but only few students completed their studies and went on to high school. The purpose of this study was to explore why leadership in the classroom is important for students.
Digital divide eller digital opportunity i Anacostia High School, Washington D.C. : en studie baserad på sistaårselever i High School
Purpose/Aim: The goal of this thesis is to examine access and knowledge computers and the Internet among the senior-year students of Anacostia High School. Do the students of this facility have the same opportunity as the residents from better socioeconomical backgrounds or are they being excluded from the technology? Material/Method: To approach the thesis goal I have used a quantitative method. More specifically, a questionnaire was handed out to the senior year students at Anacostia High School. Main results: The study has shown that most of the students of Anacostia had in some way access to computers and Internet.
Ultraljud som diagnostiskt hjälpmedel vid subklinisk mastit hos ko :
This study was performed to investigate the possibility to use ultrasonography as a diagnostic tool for sub-clinical mastitis in dairy cows. Five cows with high cell counts, and four cows with low cell counts were selected as cases and controls, respectively, and their udders examined with ultrasound during a 5 week period. The image of the udders of cows with high cell counts exhibited small, hyper-echoic, rounded foci, approximately 1 cm in diameter, near the milk cisterns and the base of the teats. These changes were not found consistently in all cows with high cell count, however. Ultrasonography may be a valuable complementary tool in the diagnosis of sub-clinical mastitis in dairy cow, but more cases need to be monitored before its full value can be ascertained..
BIM vid installationsprojektering
Planet rendering plays an important role in universe visualization and geographic visualization. The recent tools and methods allow better data acquisition, usually with very high resolution. However in computer graphics, there is always the limitation on the resolution of geometry and texture due to numerical imprecision. Not many applications can handle high resolution data effectively.This thesis introduces, Implicit Surface Scene, a level of detail scene management inspired by dynamic coordinate system and SCALEGRAPH? which change over time depending on the current camera position relative to the planet surface.
Modellbaserad temperaturregleringav partikelfiltrets regenereringsprocess
Due to increasing regulations regarding new diesel vehicles particulate matteremissions the new Scania truck, Scania Euro 6, has been equipped with a particulatefilter. This component effectively stores the particles in the exhaust gas but must becleaned in order to prevent itself from clogging. The filter is cleaned through aprocess named regeneration which is a thermodynamic process in which thetemperature of the filter is raised through fuel supplied to the exhaust gas.The purpose of this thesis is to contribute to the development of improved controlstrategies of the temperature during the regeneration process through thedevelopment of model-based controllers. These controllers are designed in order tohave good performance in stationary as well as automatic regeneration.In order to develop these model-based controllers a model of the system isconstructed. The model is described as a linear thermodynamic grey-box model withflow varying parameters, showing good results in validation.The model provides a simulation environment during the controller design, which isfocused around the development of linear regulators with the exhaust gas mass flowas a scheduling variable whose size determines controllers? mode of operation.
Tidsupplösning vid miljövärdering av fjärrvärme : Kontorsbyggnad med solvärmeproduktion - en fallstudie
The demand for environmental assessments on buildings and energy consumption is increasing as well as the energy performance requirements for buildings. At the same time it is increasingly common with self-producers of heat and electricity generation.The main purpose with this master thesis is to investigate how time resolution affects the environmental assessment of energy consumption in office buildings connected to district heating (DH). Environmental assessments were done with both attributional LCA and consequential LCA with system expansion.Fortum´s DH system in Stockholm was analyzed and district heating production was simulated in a Matlab-model. Greenhouse gas (GHG) emissions for the production were calculated. The heat demand of the office Gångaren 16 in Stockholm was simulated in IDA ICE.