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4952 Uppsatser om High temperature electronics - Sida 2 av 331
Övervakningssystem för båtelektronik
Leisure boats of today have a lot of electronics that needs battery power to work. In additionto that electric propulsion systems have gotten more popular lately, which further increasesthe demand for high battery capacity. The batteries used are mostly lead-acid batteries and toget the most out of the batteries it is important to treat them right. To optimize the electricsystem it is important to have knowledge of how the batteries and the electric motor are usedand which factors affect e.g. efficiency and recharging.A new electric drive that can replace old diesel engines is being developed and needs testingand evaluation.
Studie av Karlskogas fjärrvärmenät för att sänka returtemperaturen
A district heating plant has the advantage that it can take advantage of the waste heat from industries and use of cheap fuels to produce heat. But for the long term is competitive requires that energy is also saved in district heating plants. One way to save energy in a district heating system is to increasing cooling to the return temperature. This leads to less power needed to drive the distribution pumps, and that more energy could be extracted from the same amount of fuel by an improved flue gas condensation.In Karlskoga the return temperature into the district heating plant is high. They would therefore reduce the return temperature in order to extract more energy from the flue gases.
Inverkan av stora mängder halm som underlag i grisningsboxen på den nyfödda smågrisens temperaturreglering :
The aim of the present study was to evaluate the effects of large amounts of straw
in the farrowing pen on thermal regulation of the newborn piglet in different
weight classes. 20 sows were given 15 kg of straw in the farrowing pen
2 days prior to until 7 days after parturition. A control group of 18 sows
had no straw in the pen. 6 litters from each treatment were observed.
Measurements of piglet body temperature were made at 0h, 2h, 4h, 8h and 24h
after parturition. At ?8h? the body temperature of the piglets in the Straw group
were significantly higher (P=0,0149) than the piglets in the Control group.
TILLFÄLLIGA EFFEKTTOPPAR I FJÄRRVÄRMEN : Kan man med hjälp av lagrad värme undvika att de uppstår i betonghus?
Climate and environmental issues is now high on the agenda. We live in a generation that must try to solve some major environmental problems. Buildings and habitations account for approximately 40 % of Sweden's total energy today. To reduce this figure, as needed, more research in the field of energy efficiency is required.This thesis concerns the heating of buildings. The load on district heating is heavy during certain times of the day.
Design och konstruktion av laborationsutrustning till en kraftelektronikkurs
The purpose of this degree project was to build laboratory equipment for a new course in power electronics that starts this autumn 2010 at Uppsala University. The equipment is intended for student labs and it covers the most important areas of the course including rectifying, buck-/boost-converters and PWM-modulation. It is built as one sealed unit where all the electronics are built-in but visible and it has a connection board where students safely can connect the different circuits. The project has advanced from theoretical studies of circuit design, choosing of components and simulations to drawing the printed circuit board (PCB), soldering, case building, final testing and troubleshooting - basically most steps from an early idea to a final product. Measurements on the final product gave about the same results as the earlier simulations of the circuits and the result is overall satisfying..
Kroppstemperatur och vattenavdunstning via huden hos extremt underburna barn vid vård i kuvös och med kängurumetoden
Aim: To examine the reaction of extreme preterm infants with regarding to body temperature and transepidermal water loss during skin-to-skin care according to Kangaroo Mother Care (KMC) during the infant?s first week of life. Method: This was a descriptive quantitatively designed study, which was a pilot study within the framework of a larger project. Nine children, with a median gestational age of 24.91 weeks, were examined by measuring body temperature (axilla and skin temperature) as well as transepidermal water loss before, during and after KMC. Results: The study showed that skin temperature tended to rise during KMC, especially for those children who were nursed with KMC for more than 60 minutes.
MOLNU : Att utveckla ett gemensamt gränssnitt
Climate and environmental issues is now high on the agenda. We live in a generation that must try to solve some major environmental problems. Buildings and habitations account for approximately 40 % of Sweden's total energy today. To reduce this figure, as needed, more research in the field of energy efficiency is required.This thesis concerns the heating of buildings. The load on district heating is heavy during certain times of the day.
Utvärdering av befintliga passivhus : En byggnadsfysikalisk bedömning och mätningar om temperatur, och fukt analys på ytterväggarna
Energy price are on the way up to a high level that will not diminish in the future make us to focus more on the sustainable development for a better solution of residential houses. Passive house or low energy housing are one of the solution to make residential more environment friendly, in same time it´s a financial security using less energy, and saving money. The last 10 years in Germany and all around Europe the concept of passive house been developed, and people aim to know more about these concept that leading the market more attractive for passive houses. A passive house is a well designed building highly insulated and air tight with mechanical ventilated system for the whole building envelope that minimizes the use of energy for heating [1].The housing company Mimer has chosen to invest in low energy consumption in every new housing project. These future plan projects are decided to use less than 75 kwh per square meter annually in purchased energy [2].This thesis is about new constructed passive houses, and focuses on the evaluations of the temperature, and moisture condition for attic, external walls and joist.
The importance of shade for dairy cattle in Sweden.
Today, there are no regulations saying that cows must have access to some kind of shelter at pasture during the summer. In more tropical countries, it is well-known that dairy cows might suffer from heat stress when exposed to sun and high temperatures. The well-being of the cows is thereby reduced and the production may also decrease. In Sweden, no research has been done in the area and therefore it is now a clear need of improved knowledge.The purpose of this study was to investigate the importance of shade for dairy cows in Sweden. The behaviour of 30 cows was examined to see any differences between cows with access to shade and cows without access to shade.
Skadliga nollflödespunkter i Fortum Värmes fjärrvärmenät i Stockholm : En analys av dess förekomst och effekter
When several production units provide a district heating network, water is pumped from different directions. When the flows from the plants finally meet in the network, the water can be completely still. These places are called zero flow zones. In district heating networks with several plants, which also have different supply temperatures, large and frequent temperature fluctuations can occur when the zero flow zones move. This may cause wear on the pipes, a phenomenon called low cycle fatigue.For this reason it is important to examine where and when zero flow zones that cause temperature changes occur.
Värmestyrning I Handske
This rapport is result of a project. The purpose of which was to design a circuit that is used in a heat glove. The heat glove is the technical aid which provides heat inside a glove.It is specially suited for old people who have problems with cold hands because of decreased blood circulation.There already was an old circuit in the glove that gives a constant current which develops heat from battery to glove through a circuit. The temperature is between 32 and 34 degrees.The problem with the existing circuit was to regulate the temperature. There is only on/off switch and there is no way to adjust desirable value of the temperature.In order to solve the problem the old circuit was investigated.
Healthier vegetables through temperature stress? : a review of Brassica oleracea
The objective of this report is to present a review of the studies which has been carried out up to days date concerning how temperature affects vegetables physiologically when it comes to their health inducing as well as quality reducing features. The essay therefore starts off with defining what is meant by the terms health promoting and quality reducing features. It then moves on to describe how different subspecies of Brassica oleracea, that is to say vegetables such as broccoli, cauliflower, Brussels sprouts and kale, is affected by temperature. B. oleracea was chosen because the species contains several commercially interesting subspecies and therefore provides a broad field even though only one species is assessed.
Temperature monitoring during transport of test samples
Quality is the main focus in management of all laboratories. Accurate results of the analyses are not only determined by the analytical procedure but also by preanalytical factors. In the total analytical process of clinical specimens, there are many possible preanalytical sources of error. Monetoring of temperature on test samples of the transport boxes is one way to reduce the mistakes in the preanalytical phase.In this study, four laboratories from primary health care were invited to participate. The temperature has been measured on test samples of the transport boxes being delivered to the laboratory.In three cases the temperature remained within the limits, but in the fourth case the temperature varied more than the allowed interval.
Kontinuerlig temperaturmätning i bädden på gratevagnar
Luossavaara-Kiirunavaara Aktiebolag (LKAB) är en gruvdriftskoncern med järnmalmsbrytning som huvudsaklig verksamhet. En av produkterna tas fram genom att raffinera järnmalm till pellets vilket är en efterfrågad produkt vid ståltillverkning. Vid sintring av råkulor till pellets är temperaturen väsentlig för att få så hög oxidation som möjligt av magnetit till hematit och för att få rätt fasthet. För att reglera värmen bör temperaturen mätas bland råkulorna eftersom det är kulornas temperatur som är det viktiga. Projektet går ut på att undersöka möjligheterna att mäta temperatur bland råkulor på gratevagnar som åker genom en pelletsugn med ett permanent mätsystem. Här ställs höga krav på mätsystemet på grund av miljö, portabilitet och drifttid.Miljöanalyser gjordes för att ta reda på vilken påfrestning ett mätsystem bör klara av. Förslag om placering av mätutrustning framtogs genom kartläggning av miljön.
Sänkt returtemperatur : Potentiell besparing i fjärrvärmesystem
Optimizing energy systems is, in Sweden, as in many other countries, of growing interest. District heating systems are no exception. In 2012, 285 out of 290 municipals in Sweden had district heating in use and the majority of these systems have a higher return temperature than that which is possible with an error-free substation of day current technology. To, when possible, lower the return temperature is a way of increasing the effectiveness of the district heating system.This study means to investigate, through simulations and calculations, how big of a reduction in production cost a lower temperature in the city of Ystad?s district heating system would correspond to.