Sökning: "migration diffusion"
Visar resultat 1 - 5 av 87 avhandlingar innehållade orden migration diffusion.
1. Material migration in tokamaks : Erosion-deposition patterns and transport processes
Sammanfattning : Controlled thermonuclear fusion may become an attractive future electrical power source. The most promising of all fusion machine concepts is called a tokamak. The fuel, a plasma made of deuterium and tritium, must be confined to enable the fusion process. It is also necessary to protect the wall of tokamaks from erosion by the hot plasma. LÄS MER
2. Prediction of Chloride Penetration into Saturated Concrete Multi-Species Approach
Sammanfattning : The cost due to rehabilitation of corroded reinforced concrete structures is a worldwide matter of concern. The mechanisms of reaction-diffusion involved during the transport of chloride ions into saturated concrete, which are initiating the corrosion process, are therefore studied in this thesis. LÄS MER
3. Alternative methods for analysing moisture transport in buildings : Utilisation of tracer gas and natural stable isotopes
Sammanfattning : New methods, based on tracer gas measurements and isotopicanalysis can be used to evaluate the moisture properties ofbuilding materials and provide the means for forensic analysisof the origins and history of excessive water in buildings, theimmediate practical consequences of which will be the abilityto improve the moisture performance of constructions. It is shown, in theory and through measurements how thewater vapour permeability of porous building materials can witha good degree of accuracy be estimated with tracer gasmeasurements that provide an efficient alternative to the cupmethod. LÄS MER
4. Migration from plastic food packaging during microwave heating
Sammanfattning : Microwave heating of food has increased rapidly as a food processing technique. This increases the concern that chemicals could migrate from food packaging to food. The specific effect of microwave heating in contrast to conventional heating on overall and specific migration from common plastic food storage boxes was studied in this work. LÄS MER
5. Ageing behavior of plastics used in automotive fuel systems
Sammanfattning : The increase in service temperature and the use of biobased fuels, such as biodiesel, have raised concerns on the short/long-term performance of plastic components used in automotive fuel systems.In this work the ageing behavior of unreinforced and glass-fibre reinforced polyamide 12 (PA12), exposed to three different fuels (petroleum diesel, biodiesel, and a mixture of these (80/20)) at high temperature, was investigated. LÄS MER
