Sökning: "thermal ageing"

Visar resultat 11 - 15 av 62 avhandlingar innehållade orden thermal ageing.

  1. 11. The Plastic Flow Behaviour of Aluminium Alloys Exhibiting Dynamic Strain Ageing

    Författare :Magnus Hörnqvist Colliander; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Al-Zn-Mg; Dynamic strain ageing; Strain rate sensitivity; Portevin-Le Chatelier effect; Temperature sensitivity; Thermal activation;

    Sammanfattning : The phenomenon known as dynamic strain ageing, abbreviated DSA, has been known since the beginning of last century. It was first discovered as serrations in the load-elongation curve obtained upon deforming specimens of certain alloys in tension. This phenomenon became known as the Portevin-Le Chatelier (PLC) effect. LÄS MER

  3. 12. Formation, ageing and thermal properties of secondary organic aerosol

    Författare :Eva U. Emanuelsson; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; volatile organic compounds; biogenic; anthropogenic; secondary organic aerosol; troposphere; volatility; ozone;

    Sammanfattning : In order to properly represent and predict the effects of aerosol in climate systems, an accurate description of their formation and properties is needed. This thesis describes work done to increase the knowledge of processes and properties of atmospherically relevant secondary organic aerosol (SOA) from both biogenic and anthropogenic origin. LÄS MER

  4. 13. Assessment of the lifetime of district heating pipes

    Författare :Alberto Vega; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; FTIR; rigid polyurethane foam; artificial ageing; {District heating pipes; natural ageing; degradation mechanisms; mechanical performance;

    Sammanfattning : This thesis is concerned with the degradation and assessment of the lifetime of district heating pipes, where accelerated ageing is used to study the degradation in a short time frame. The project was divided into four interrelated parts. LÄS MER

  5. 14. Partial Discharge Signatures of Defects in Insulation Systems Consisting of Oil and Oil-impregnated Paper

    Författare :Mohamad Ghaffarian Niasar; Hans Edin; Peter Werelius; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; partial discharge; transformer; oil; ageing; temperature; PD classification;

    Sammanfattning : Partial discharge measurement is a common method for monitoring and diagnostics of power transformers, and can detect insulation malfunctions before they lead to failure. Different parameters extracted from the measured PD activity can be correlated to the PD source, and as a result it is possible to identify the PD source by analyzing the PD activity. LÄS MER

  7. 15. Long-term Performance of PVC and CSPE Cables used in Nuclear Power Plants : the Effect of Degradation and Plasticizer migration

    Författare :Maria Ekelund; Ulf Gedde; Thomas Hjertberg; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; PCV; CSPE; cables; ageing; mechanical properties; plasticizer migratio; LIRA; life time prediction; Chemistry; Kemi;

    Sammanfattning : Enormous amounts of low voltage cables installed in a Swedish nuclear power plant are reaching their expected lifetimes. Since the cables are crucial to operational safety, it is of great importance that the actual condition of the installed cables is determined. LÄS MER