Sök:

Sökresultat:

2216 Uppsatser om Vacuum technology - Sida 1 av 148

En jämförelse mellan vakuumisolering och traditionell isolering

The purpose of this thesis is to investigate if vacuum insulation panels are a competitive alternative to traditional insulation.Vacuum insulation has been used as insulation in buildings in Germany and Switzerland for a few years. In Sweden the high-performance insulation material is mainly used in refrigerators, freezers and vacuum thermoses. The development is proceeding well and vacuum insulation is becoming more common in the construction industry. Since it is a relatively unexplored material on the market there are many flaws and problems with the material.The questions we have chosen to answer in this report include an increased knowledge of vacuum insulation, various problems that may arise when handling/installation and the pros and cons of vacuum insulation compared to standard traditional insulation.The methods we have chosen to use in this report is a literature study, interviews with various suppliers and manufactures and calculations to show the differences between traditional and vacuum insulation. Vacuum insulation is 5-10 times better insulation than standard traditional mineral wool insulation, mainly at the beginning of its lifetime.Vacuum insulation panels (VIP) have a service life of approximately 50 years, whereas traditional insulation has a service life of approximately 100 years.

Dammsugare att motivera till dammsugning

How can a vacuum cleaner motivate you to use it? From a sustainability perspective,the author asked the question of how such a solution would looklike? These where issues that the project tackled and devised solutions for. Theproject wanted to explore the physical modeling and a large part of the finalresult consisted of a full scale model. The project found that the problem ofvacuuming largely consisted of the problem of storage the product. The projectfound that the motivation for the job, therefore, could be resolved by a betterdesigned vacuum cleaner with a built-in hose, folding handles, which couldbe stored integrated within the vacuum cleaner.

Vakuumbrytare i småskaliga vattenkraftstationer

This master thesis has been performed at Vattenfall Power Consultant in Gothenburg and Trollhättan for Vattenfall Vattenkraft. In this report vacuum circuit breaker in small-scale hydropower stations with the rated power 4 MVA and below has been studied. Models of the stations are modeled and analyzed in PSCAD/EMTDC to study the high voltage transients that are created after current chopping with vacuum circuit breaker. Vacuum circuit breaker may chop the current before it reaches zero value, which means that high voltage transients can be created. The equipment of the stations can be destroyed by high voltage transients.The purpose of this thesis is to examine the use of vacuum circuit breaker in small-scale hydropower stations and the risk for high voltage transients from current chopping.According to the results there is a risk of high voltage transients after current chopping with small synchronous generators in stations with the operating voltages 0.4 kV and 3.6 kV.

Laserinkopplingselement För XFEL Laser Heater : Från Idé Till Färdig Produkt I Designstadie

Uppsala University is involved in a large international collaborationto build the Laser heater system for the European Xray Free-electronlaser in Hamburg, Germany. In this thesis I describe a laser incouplingdevice into the vacuum chamber of this laser heater all the way fromthe specifications to a completed design.The laser heater is a very important part of the XFEL and thepart described here is a part of the vacuum system needed to couplean external laser into the electron vacuum system and align it withthe electron bunches in order to heat them. The task was started by studying the literature about the basic theory andthe design of vacuum systems. After this study and collection of ideaswith colleagues I started to prepare different concepts to solve thetask. The ideas can be put into two categories, in one case the couplingmirror is located inside the vacuum chamber and in the second caseoutside.

Immobilisering av extremitetsfrakturer inom ambulanssjukvård : Ett pilotprojekt med SAM-splint

Within the ambulance care in Uppsala County a vacuum splint is used to immobilize fractures on extremities. The research available on which method of immobilizing to prefer during pre-hospital treatment is limited. The purpose of this pilot study was to examine the perceptions of the ambulance personal in Uppsala County on the issue of usability of SAM-splint and vacuum splint when immobilizing extremities. The project was also aimed at researching if SAM-splint could be seen as an alternative or a complement to vacuum splint, and to get an apprehension on any evident differences in patients? perceived pain when treated with the two different approaches. A descriptive comparative study was carried out. All patients, regardless of age and sex, with the need of immobilizing supposed fractures, were included.  Patients with suspected femur fracture, collum fracture, or where pre-hospital care was not possible or in question, was excluded.

Utsidan räknas : ?En materialstudie

Judged by appearance. This is the conclusion of research made on shopper behavior that revealed that consumers tend to go by their instinct when evaluating vacuum cleaners in a purchasing situation. Many buy the first vacuum cleaner they interact with and few buy pre-planned brands. Almost none even turn the machine on before taking a purchase decision.Electrolux Floor Care Europe has their factory for vacuum cleaners in Hungary. Increased competition from China makes it harder to "only" produce vacuum cleaners with good performance.

Flickors kroppsuppfattning och måltidsmönster : Förändring under pubertet och moderns betydelse

Within the ambulance care in Uppsala County a vacuum splint is used to immobilize fractures on extremities. The research available on which method of immobilizing to prefer during pre-hospital treatment is limited. The purpose of this pilot study was to examine the perceptions of the ambulance personal in Uppsala County on the issue of usability of SAM-splint and vacuum splint when immobilizing extremities. The project was also aimed at researching if SAM-splint could be seen as an alternative or a complement to vacuum splint, and to get an apprehension on any evident differences in patients? perceived pain when treated with the two different approaches. A descriptive comparative study was carried out. All patients, regardless of age and sex, with the need of immobilizing supposed fractures, were included.  Patients with suspected femur fracture, collum fracture, or where pre-hospital care was not possible or in question, was excluded.

Vakuumisolering ? Ekonomiskt försvarbart för småhus?

The number of people in the world and the urbanization increases. This leads to a bigger need of space for the built environment, space that soon doesn?t exist. A large portion of humanity?s energy disposal is used for heating of buildings.

Definition av stötdämpares fyllnadsgrad

Shock absorber units play a key role in establishing the driving dynamics and performance of automobiles. Öhlins Racing has manufactured high-tech automotive shock absorbers for over 30 years. Öhlins Racing?s advanced technology has contributed to over 200 world championships in automobile racing. Öhlin?s manufacturing process has long utilized automated fluid filling equipment during the final shock absorber unit assembly stage. The filling process consists of vacuum pumping the shock absorber unit and subsequent transfer of fluid. Vacuum pumping is necessary to remove residual air from the shock absorber unit prior to initiating the liquid filling stage. The presence of undesirable gases drastically compromises the performance of a shock absorber. The filling degree, defined as the final ratio of air to oil, is determined by the specific filling protocol as well as the specific equipment utilized.The current investigation aims to develop a viable technique to accurately determine residual air content in shock absorber units. If the filling degree can be appropriately quantified for a specific manufacturing process, then the air/oil ratio may be quantitatively related to shock absorber performance. The utilized measurement method must be completely integrated into the manufacturing process to guarantee shock absorber performance specifications according to the manufacturer?s standards. By utilizing the measurement method developed in this work, the manufacturing process, manufacturing equipment and product specifications can all be tailored to provide improved filling conditions.The developed measurement method provides accurate quantification of the filling degree under a wide range of processing conditions. The method establishes the relative quantity of air in the shock absorber unit by performing in-situ compressibility tests. The fill ratio can be controlled and varied by manipulating the vacuum pressure exerted during the filling process. Performance tests, however, indicate no correlation between filling degree and unit performance..

Analys av arbetsmiljö vid kokarpåsvetsning samt förslag till förbättringar.

Denna rapport är ett inledande steg mot att förbättra arbetsmiljön för svetsare vid påsvetsning med Uddcomb Metoden i massakokare. Syftet med rapporten är att analysera problemet med värme och dålig luft samt förklara hur och varför problemet uppstår. I arbetet ingår även att ta fram olika lösningar för att slutligen hitta ett komplett system för ventilation och kylning. Den föreslagna lösningen består av ett integrerat kylsystem och ett koncept med mindre fläktar, kallade torpeder, som monteras på arbetsplanen vilka driver ut varm och smutsig luft snabbare ur kokaren. Den föreslagna lösningen utreds även ur ett ekonomiskt perspektiv.

Utveckling av ett dammsugarmunstycke för energieffektiv dammupptagning

Development of a vacuum cleaner nozzle for energy efficient dust pick-up.

Utveckling av omrörningsenhet

The use of technology in today's society is frequent and often necessary, but how, when and where are we supposed to learn how to use it? And if it is such a big and important part of our society, then why don?t teachers get more training in how to use the technology? The purpose of this paper is to examine whether teachers attitudes to technology affects their use of technology in their teaching. In school technology can be a complementary to other material, if teachers have the necessary skills to use technology in a pedagogical way. I have chosen to do a qualitative study in form of interviews and observations at a school outside of Stockholm. The results show that both school and teachers must want to work with technology if anyone will be getting something out of it.

Läraren Vs. Tekniken : en undersökning om lärares förhållningssätt till tekniken i undervisningen

The use of technology in today's society is frequent and often necessary, but how, when and where are we supposed to learn how to use it? And if it is such a big and important part of our society, then why don?t teachers get more training in how to use the technology? The purpose of this paper is to examine whether teachers attitudes to technology affects their use of technology in their teaching. In school technology can be a complementary to other material, if teachers have the necessary skills to use technology in a pedagogical way. I have chosen to do a qualitative study in form of interviews and observations at a school outside of Stockholm. The results show that both school and teachers must want to work with technology if anyone will be getting something out of it.

Teknik i bilderböcker

AbstractThe purpose of this study is to see how technology is presented in different fictional picture books that are available in preschool. Six fictional picture books that have connection to technology in picture and text have been analysed. In order to show how technology can be made visible in fictional picture books, the relation between picture and text has been analysed through a technology perspective. Furthermore, the pictures and the texts have been analysed separately in order to show what they show respectively in terms of technology. The fictional picture book has a potential to be a basis for making technology visible in preschool, which is a step in a new direction.

Listeria monocytogenes i vakuumförpackad lax :

Listeriosis, which is caused by Listeria monocytogenes, is a rare food borne disease that primarily affects people whose immune system is weakened. These may be elderly people, pregnant women, new-born infants and individuals on immunosuppressive medication. The most common symptoms are meningitis, septikemia and abortion. The mortality is high, on average 20-30 %. In recent years the number of cases in Sweden has increased.

1 Nästa sida ->