Sökning: "utmattning"

Visar resultat 11 - 15 av 51 avhandlingar innehållade ordet utmattning.

  1. 11. Refining the fatigue assessment procedure of existing steel bridges

    Författare :John Leander; Raid Karoumi; Bert Norlin; John D. Sørensen; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Fatigue; Steel bridges; Assessment; Reliability; Monitoring; Utmattning; stålbroar; bärighetsberäkning; tillförlitlighet; mätningar; Söderström; getingmidjan;

    Sammanfattning : This thesis treats the fatigue assessment process of steel bridges. The purpose is to identify areas with potential of enhancement with an overall aim of attaining a longer service life. The aging bridge stock in Sweden and in many other developed countries is an impending economical burden. LÄS MER

  3. 12. Office type, performance and well-being : A study of how personality and work tasks interact with contemporary office environments and ways of working

    Författare :Aram Seddigh; Hugo Westerlund; Erik Berntson; Fredrik Jönsson; Eva Vingård; Stockholms universitet; []
    Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; Office type; open-plan office; flex office; cell office; performance; job satisfaction; distraction; self-rated health; well-being; cognitive stress; exhaustion; individual differences; personality; concentration; stim-ulus screening ability; memory; Kontorstyp; kontorslandskap; flexkontor; cellkontor; produktivitet; arbetstillfredsställelse; distraktion; självskattat hälsa; trivsel; kognitiv stress; utmattning; individuella skillnader; personlighet; koncentration; arbetsminne; Psychology; psykologi;

    Sammanfattning : Today, many organisations are adopting offices that have an open design with or without flexible seating. While advocates of open-plan offices propose that these office types lead to cost savings and aid inter and intra-team communication, opponents argue that these office types are associated with decreased performance and worsened health among employees. LÄS MER

  4. 13. Initiation of rolling contact fatigue from asperities in elastohydrodynamic lubricated contacts

    Författare :Carl-Magnus Everitt; Bo Alfredsson; Stefan Björklund; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Spalling; Pitting; Slip; Elastohydrodynamic; Thermal elastohydrodynamic; Fatigue; Contact mechanics.; Pitting; Glidning; Elastohydrodynamik; Termisk elastohydrodynamik; Utmattning; Kontaktmekanik.; Hållfasthetslära; Solid Mechanics;

    Sammanfattning : Rolling contacts are utilized in many technical applications, both in bearings and in the contact between gear teeth. These components are often highly loaded, which makes them susceptible to suffer from rolling contact fatigue. This work focuses on the rolling contact fatigue mechanism of pitting. LÄS MER

  5. 14. An Epidemiological Study of Exhaustion in the Context of Chronic stress. Concept, Cortisol, Causes and Consequences

    Författare :Sara Lindeberg; Socialmedicin och global hälsa; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; chronic stress; cortisol; depression; exhaustion; gender; HPA activity; psychosocial;

    Sammanfattning : The interest in exhaustion has increased rapidly during the last few decades in many developed countries. In Sweden, prevalence of exhaustion increased by 50 percent on average between 1989 and 2005, and recent data reveals that exhaustion still remains at this higher level. Scientifically, exhaustion is not clearly defined. LÄS MER

  7. 15. Oxidation, Creep and Fatigue Synergies in Cast Materials for Exhaust Manifolds

    Författare :Shengmei Xiang; Joakim Odqvist; Baohua Zhu; Stefan Jonsson; Johan Ahlström; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Fatigue; low-cycle fatigue; fatigue in an inert atmosphere; fatigue in a synthetic diesel exhaust atmosphere; corrosion-fatigue; creep-fatigue; high-temperature corrosion; high-temperature fatigue; synergistic effect; corrosion-fatigue synergy; creep-fatigue synergy; high-temperature alloys; fatigue damage; creep-fatigue damage; corrosion-fatigue damage; ductile cast iron; high-alloyed austenitic cast steel; thermal cycling; precipitation; aging.; Teknisk materialvetenskap; Materials Science and Engineering;

    Sammanfattning : The future development of engines of heavy-duty vehicles towards reduced CO2 emission will increase the exhaust gas temperature and render the exhaust atmosphere more corrosive. The current service material of exhaust gas components - a ferritic ductile cast iron called SiMo51 - will soon meet its upper-temperature limit. LÄS MER