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286 Uppsatser om Thermal radiation - Sida 5 av 20
Utveckling av metod för retrospektiv bestämning av absorberad dos i korall medelst elektronspinnresonans
This diploma work was performed at the department for radiation physics at the Health University in Linköping. Its aim was to develop a method to retrospectively quantify the absorbed dose in coral. Coral is a material which suites well as a retrospective dosimeter because when exposed to radioactivity its induced free radicals are stable in time. The number of radicals is proportional to the accumulated dose so the dose can be calculated by quantifying the radicals. Therefore, coral can tell us something about the past environment and also be used in dating purposes.A young, modern coral from the Red Sea was studied and also a fossil one which I was given from the Natural History Museum in Stockholm.
Kompressionsdokumentation och kompressionens inverkan på patientstråldos vid ländryggsröntgen
Enligt arbetsmiljölagen ska arbete planläggas och anordnas rätt, så att det kan utföras i en säker och sund miljö. Trots det inträffar arbetsplatsolyckor i Sverige av olika anledningar. Ett uppdrag har tilldelats författaren för att öka förståelsen för hur anställda på Peab Anläggning AB i Region Mellansverige anser att företaget kan nå sitt mål att halvera antalet arbetsplatsolyckor till år 2017. Sex semistrukturerade intervjuer genomfördes med anställda på företaget. Intervjuerna transkriberades och analyserades genom en manifest innehållsanalys.
Renovering av miljonprogrammet till Umeå kommuns nybyggnadskrav för energianvändning
A lot of houses built during the Million Homes Programme are in need of major renovation. Today?s technology and materials are better than in the 60?s and 70?s. Both Swedish government and the European Union have set climate goals regarding energy consumption by 2020 and 2050. Achieving these goals would require better standards in buildings than the Building regulations demands, such as Umeå municipality?s construction requirements for new buildings.The report aims to investigate if a renovation of apartment buildings from the Million Homes Programme can reach Umeå municipality?s construction requirements.
Utvärdering av laddningskoncept för lastbilsbatterier
When drivers overnight in the truck lots of electric energy is consumed by heaters, fans, lights and other extra equipment. If the engine is not running, this energy is taken from the lead/acid batteries of the truck which then needs to be recharged during operating hours. The fact that the charge acceptance of the lead/acid batteries is dependent on the temperature makes it hard to fully recharge the batteries at lower temperatures. A negative charge balance can lead to starting problems within a few days use in cold climate.In this thesis work, the effects of different battery charging concept are evaluated on the most common Scania battery (175Ah). A battery model is implemented in Matlab and some simulations of charging are made.
Statusbedömning och förbättringsförslag för startkedjemaskineri, startkedja och linspel för stränggjutningsmaskin
The main goal with the master thesis has been to do a status evaluation of the chain machinery with its start chain and wire to secure the production on a short basis due to that a reconstruction is not planned at this time. An evaluation of the condition of the start chain and the rollers in the chain depository has been done. An offer has been requested for a new start chain and the evaluation of the start chains may be a basis for the decision taking. The production has been able to go on, although it has arisen some problems which have been difficult to find the causes for. There is no gathered ?picture? of the machinery status and a mapping of each machinery has been compiled of comprehensive logs.
Högtempererat borrhålslager för fjärrvärme
The district heating load is seasonally dependent, with a low load during periods of high ambient temperature. Thermal energy storage (TES) has the potential to shift heating loads from winter to summer, thus reducing cost and environmental impact of District Heat production. In this study, a concept of high temperature borehole thermal energy storage (HT-BTES) together with a pellet heating plant for temperature boost, is presented and evaluated by its technical limitations, its ability to supply heat, its function within the district heating system, as well as its environmental impact and economic viability in Gothenburg, Sweden, a city with access to high quantities of waste heat.The concept has proven potentially environmentally friendly and potentially profitable if its design is balanced to achieve a good enough supply temperature from the HT-BTES. The size of the heat storage, the distance between boreholes and low borehole thermal resistance are key parameters to achieve high temperature. Profitability increases if a location with lower temperature demand, as well as risk of future shortage of supply, can be met.
Vidareutveckling av provplattform för mätning av kosmisk strålnings inverkan på DRAM
Sammanfattning: SAAB Communication i Linköping sysslar med konsultverksamhet mot ett flertal nationella och internationella företag inom både den civila och militära sektorn. Fokus ligger på flyget med uppdrag inom telesystem, radiosystem, signaturanpassning, EMC, atmosfärisk påverkan mm. I det sistnämnda ingår även kosmisk strålnings inverkan på elektronik. Den fortsatta miniatyriseringen av elektronik, speciellt minneselektronik leder till ökad känslighet mot den kosmiska partikelstrålningen som ständigt regnar ner på jorden, därför är det extra noga att minnen testas innan de sätts i bruk vid flygburna system. Syftet med detta examensarbete är att konstruera en provplattform som registrerar fel som uppkommer i ett DDR2 SDRAM minne vid påverkan av den ovannämnda strålningen.
Vidareutveckling av provplattform för mätning av kosmisk strålnings inverkan på DRAM
Sammanfattning:
SAAB Communication i Linköping sysslar med konsultverksamhet mot ett flertal
nationella och internationella företag inom både den civila och militära
sektorn. Fokus ligger på flyget med uppdrag inom telesystem, radiosystem,
signaturanpassning, EMC, atmosfärisk påverkan mm. I det sistnämnda ingår även
kosmisk strålnings inverkan på elektronik. Den fortsatta miniatyriseringen av
elektronik, speciellt minneselektronik leder till ökad känslighet mot den
kosmiska partikelstrålningen som ständigt regnar ner på jorden, därför är det
extra noga att minnen testas innan de sätts i bruk vid flygburna system.
Syftet med detta examensarbete är att konstruera en provplattform som
registrerar fel som uppkommer i ett DDR2 SDRAM minne vid påverkan av den
ovannämnda strålningen. Detta examensarbete är en vidareutveckling av en
provplattform baserad på en FPGA ? lösning.
En jämförande studie mellan datortomografi och konventionell röntgen av sinus
Röntgenläkarna väljer ofta att byta undersökningsteknik för att fastställa misstänkt patologi som inte går att diagnostisera med en metod. Vid röntgenundersökningar av sinus (bihålor) så kan läkaren välja mellan konventionell röntgen eller en datortomografiundersökning. Skälet är att diagnoser som tumör, benpåverkan eller ansiktstrauma inte avbildas lika bra med den konventionella metoden. Syftet med den här studien är att jämföra datotomografi och konventionell röntgen vid sinusundersökningar, vilka för och nackdelar som de olika metoderna har, hur bildinformationen och diagnostiken skiljer sig, vilka risker som finns med joniserad strålning samt vilka biologiska effekter strålningen har på människan. Intervju har gjorts med odontologi läkare som berättat om för och nackdelar med de olika metoderna, och litteratur och artiklar har gett kunskap för att komma fram till resultatet.
Radon i flerbostadshus : Kartläggning av fastighetsförvaltarnas egenkontroll avseende radon
Radon is a hazardous substance that cannot be perceived by our senses. It has long been known that exposure to high radon levels for a long period of time will ultimately cause lung cancer. The Swedish Radiation Safety Authority estimates that 500 people die annually due to this. Although most of them are smokers, even non-smokers suffer from lung cancer caused by radon. The statutory value for radon in homes today is 200 Bq/m³.
Uppvärmd konstgräsplan : Beräkning av utnyttjningstid för en uppvärmd konstgräplan med alternativa rörplaceringar
For Skattkärr IF a turf field with warming has been projected to increase field?s utilization hours and to have a longer period for athletes to perform their activities outdoors. The technique chosen to heat the plan is a type of a geothermal heating system without a heat pump. The brine, which is water with 30% ethanol, collects heat from the borehole and discharges it to a coil in the field. There is at position 11 boreholes but it is planned to increase the number to 31, which is the design for the facility.
Bakteriereduktion i diskmaskiner : Studie av olika metoder för att reducera bakterier
Bacteria are a problem that occurs naturally in dishwashers when the dish stands there dirty for an extended period of time. To get rid of the unpleasant smell that the bacteria is causing, the most common solution is to run a regular washingcycle which can cause problems for the environmentally-conscious consumers since this causes unnecessary energy waste and emissions of chemicals in the washwater. To solve the problem in a more environmentally-friendly way by directly attacking the bacteria with an appropriate bacterialreductionmethod can therefore be an attractive feature in a dishwasher. There are many different ways to treat surfaces that have been exposed to the bacteria. Some high-profile methods are UV-radiation, microwaves and oxidant (ozone) that all three have had success in reducing bacteria in different contexts.
Jämförelse av verklig och modellerad elproduktion från en solcellsanläggning : En utvärdering av två simuleringsverktyg.
This thesis has been carried out in New Zealand in collaboration with the University of Waikato. In association with Dr. Mike Duke the purpose of this work is to investigate whether two different software for modeling of photovoltaic systems are useful in the teaching of solar energy.The next ten years grid-connected photovoltaic systems are assumed to increase and therefore also a rising demand for people with engineering knowledge are to be predicted. For engineer students with a focus on solar energy a more practical teaching with design software´s can be a good method to make the students comprehend more when it comes to large scale photovoltaic systems and be more prepared for working life.The software´s used is called Transient System Simulation (TRNSYS) and Photovoltaic Systems (PVSYST) which are both well used throughout the world. To assess the reliability of the software´s, a reference solar power plant at 16.1 kWp installed capacity are used, which consists of photovoltaic modules from four different manufacturers.
Simulering av kabelbränder i sekundära säkerhetssystem med CFD-koden SMAFS
This report contains CFD-simulations of cable tray fires in nuclear power plant applications with the CFD-code SMAFS. Furthermore the report evaluates the use of CFD-codes within this kind of problems. The assessment of this report is that there is a tendency towards the good use of CFD-codes but before using it solely more research has to be done on the subject..
Solenergi En del i ett långsiktigt, hållbart byggande
The sun is essential to life on earth and no matter where you are, there is a constant need ofenergy. Nearly 800 000 years ago man learned for the first time to use fire in a controlled way.Since then, fire has given us the opportunity to inhabit places despite a cold climate. In Swedenthe resident sector accounts for a major part of the total consumption of energy. In a time whenenvironmental issues and greenhouse effects are increasing, we also see a future of rising energyprices. With this perspective, we have in this bachelor thesis in the Building Environment at theRoyal Institute of Technology, KTH, in Stockholm decided to focus on the renewable energysource, solar energy.The energy from solar radiation is a free resource and does not have any negative effects uponthe environment.