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4952 Uppsatser om High temperature electronics - Sida 10 av 331

Studie av nötnings- och friktionsegenskaper vid höga temperaturer i Kanthal APMT

During this master thesis, wear and friction properties for the high-temperature alloy Kanthal APMT were studied. The results were also compared to 253MA. The initial tests showed, among other things, that the surface fineness of the muffle tubes matters in real applications like conveyor belts. A 253MA-sample wear-tested against a 253MA-tube showed lowest wear at 900°C while a pre-oxidized APMT-sample wear-tested against a APMT-tube had the lowest mean value of the friction force at 1100°C, compared to all other tests..

Ström- och temperaturkontroll

Storing kinetic energy in a flywheel allows for more efficient driving of electricvehicles. Research in this area is in progress at Uppsala University, where a flywheelwith magnetic bearings encased in a vacuum chamber is being constructed. To makethis possible methods for measuring the current through the electromagnets in thebearings and temperatures in the flywheel need to be developed. This has been thepurpose of this report. The current measurement resulted in a resistive method, andthe implementation of eight measurement circuits in the system.

Förebyggande av hypotermi under narkos på hund och katt: vad görs på svenska djursjukhus idag, och vilka evidens finns för olika behandlingsmetoder?

Hypothermia during anaesthesia is a well-known phenomenon that may cause several side-effects such as greater risk of postoperative wound infection and increased risk of heart complications. The most efficient way to avoid this is to prevent hypothermia from occurring. The aim of this paper was to compile the research on the most efficient way to prevent hypothermia during anaesthesia for cats and dogs, and to compare these results to how Swedish animal hospitals prevent hypothermia today. To investigate this, a survey was sent out to several animal hospitals around Sweden to see what methods they used to prevent hypothermia in their clinics. It is difficult if not impossible to prevent the body temperature from falling slightly when anaesthesia is induced because of the drug interactions in the body that follow from the drugs given. A 1-1,5°C decrease in body temperature is to be expected and is difficult to avoid.

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).

Datorstödd implementering med hjälp av Xilinx System Generator

The development in electronics increases the demand for good design methods and design tools in the field of electrical engeneering. To improve their design methods Ericsson Microwave Systems AB is interested in using computer tools to create a link between the specification and the implementation of a digital system in a FPGA. Xilinx System Generator for DSP is a tool for implementing a model of a digital signalprocessing algorithm in a Xilinx FPGA. To evaluate Xilinx System Generator two testcases has been designed. The testcases are selected to represent the FPGA designs made at Ericsson Microwave Systems.

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.

Avfyrnings-/relälåda

This is a report of our examination project in electronics carried out for Bofors Test Center in Karlskoga. The task was to construct an electronic devise for starting up different kinds of measuring systems in exact time during test sequences. The modules that are used today are old and unreliable. Our goal was to construct a prototype, which later on is supposed to be developed into a useful system..

Konstruktion och utvärdering av diplexer

The report descripbs how a diplexer for a hybrid analog/digital filterbank has been constructed and tested. A diplexer divides the frequency band into two different bands that do not who doesn't overlapp each other. The sampling rate for the two ADC:s is 80 Msps, and therefore it is advantage to have zero at 80 MHz. The reason for this is that a proposed class of hybrid filterbanks with very good quality requires a zero at or close the sampling frequency to work well. The diplexer was made in three versions.

Hur påverkas beteende/känslor och fysiologiska faktorer på människa och häst vid interaktion mellan parterna? :

The aim of these two studies was to investigate the possible physiological, behavioural and emotional changes that appear after human-horse interactions and also to find an explanation to why they occur. One aspect that is discussed is whether the wellbeing of humans can be coupled to interacting with horses and of how the animals respond to the interaction. The first study was performed on 9 horses and their owners, both parts being subjects to registrations during 4 different interaction treatments. The second study was performed on 6 horses with registrations only being performed on the horses during 2 different treatments. Nine horses underwent 3 different treatments all performed by their owners (H = stroking of the horses forehead, B = brushing and M = stimulation of the withers) in addition to a control round (K). Each treatment lasted for 4 minutes but observations were performed until after 45 minutes from start.

Vallfoderproduktion i norrländskt klimat till högpresterande hästar :

High-performance equine athletes have an energy requirement that often reaches twice the maintenance requirement. Horses are grazers and adapted to a grass diet, and diets high in grains and concentrates are associated with digestive upsets and behavioural disorders. It could therefore be of interest if the energy requirement of a high-performing horse could be met by forage. It is important that the forage have a high concentration of energy so that the horse is able to consume the whole amount of energy needed from the forage without exceeding the maximum voluntary intake. The purpose of this literature study was to investigate if the energy demand of a high-performance horse can be covered by forage produced under Northern Swedish climate conditions.

Vad är ?rätt? gjutkvalitet? Hur uppnås det?

Ever since ABB has begun diecasting their rotors instead of permanent mold casting it,variation in the quality of the cast has arisen. Diecasting is performed in three differentmachines, M1, M2, M3 with 400, 660 respectively 800 tons of die locking pressures.The aim of this thesis is to answer the following questions:What is the ?right? cast quality? How is the right quality achieved?For sizes 160-180 solutions will be proposed that consider eccentricity between thelaminate and the short circuit ring as well as elimination of the thin Al film that appearson the outer periphery of the rotors.Through considering the statistic material the most often diverging rotor type has beenidentified and one of the actual rotors has been sent to a laboratory to be analyzed inorder to establish the current defects. The result of the analysis shows that there areplenty of gas- and oxide-porosity.It has been proved that every time the dies temperature decreased below 120°C thecontent of gas porosity increased. It is due to rapid solidification of metal that flowsthrough the ?cold? laminate.It has confirmed that enhanced porosity in squirrel cage causes high impedance in therotors.

Development of Liquid Cooling for PCs

In recent years, existing solutions for cooling personal computer CPUs have been supplemented by a new product category, factory sealed water cooling loops. These systems, consisting of a water block with an integrated pump, a fan and a radiator, perform well compared to the air cooling solutions but are less effective than larger, custom-built water cooling systems.This project aims to explore the most important aspects of a factory sealed system and to identify possible cost-effective enhancements of the performance.The most significant differences between the different groups of water cooling loops are the block design and the pumping power. The performance of both categories is also largely dependent on the fan power, but increasing fan power has a large negative impact on the noise level.Both radiator size and fan model choice appear, in tests, to be relatively unimportant, presuming that the noise level is kept constant. The position and direction of the fan, however, has significant impact on both the temperature and the sound level.Water blocks can be designed in several different ways, both regarding the heatsink design and the flow direction. In simulation, flow with the inlet centered above the heatsink result in considerably lower pressure drop and slightly higher temperatures than flow through the block, for heatsinks with fin arrays.Creating a competitive product in this product segment certainly seems possible, as there are performance-increasing changes to be made that seemingly has little impact on the production cost.

Varmsmidning av aluminiumlegering 6026 T9 : Warm forging of aluminum alloy 6026 T9

In this project forging of aluminum alloy Al 6026 T9 has been performed in the temperature range of 400 °C ? 470 °C. The alloy which was in the shape of a cylindrical billet was formed in a press with the aim of analyzing the effect of different forging temperatures and required press load for optimal die filling. The component?s dimensions were later measured and compared to a reference piece.

Status och hotbild för den oceaniska laven broktagel Bryoria bicolor i sydvästsverige :

Horse-hair lichen Bryoria bicolor is a red-listed lichen species in the category Vulnerable. It is an oceanic lichen and it is often found on boulders and cliffs in a semi-open environment with a high humidity in the agricultural landscape. The species can also be found as an epiphyte on trees, mostly in boreal forests in the provinces of Dalarna, Härjedalen and Jämtland. In the agricultural landscape, there has been indications on that B. bicolor show a decline, and this studie aimed at examining the extent and causes of this decline.

Analys av QoS i mellanvaran Meteor

This thesis is closely related to the Dynamically Self-Configuring Automotive System(DySCAS) project. DySCAS is a middleware for electronics in an automotive system. Thethesis work has been performed in cooperation with ENEA. Parts of the demonstrationplatform Self configurable High Availability and Policy based platform for Embeddedsystem (SHAPE) developed for the DySCAS project by ENEA have been used in theimplementation phase of this master thesis.The goal of this thesis was to evaluate how the Meteor MW, an offspring of the DySCASmiddleware, should handle QoS and to design a Quality of Service Manager (QoSM) for theMeteor MW that fulfilled hard real-time requirements. The thesis also had the objectiveof analysing and identifying the requirements on such a QoSM from a QoS perspective.Specifically the requirements to guarantee real-time support for applications running onthe MW.

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