Sökning: "Christian Öberg"

Visar resultat 1 - 5 av 6 avhandlingar innehållade orden Christian Öberg.

1. 1. Creep Behavior of High Temperature Cast Materials for Exhaust Applications

   Författare :Christian Öberg; Stefan Jonsson; Baohua Zhu; John Hald; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Creep; creep behaviour; creep damage; ductile cast iron; high-alloyed austenitic cast steel; thermal cycling; tensile testing; stress relaxation; oxidation; precipitation.; Teknisk materialvetenskap; Materials Science and Engineering;

   Sammanfattning : This thesis focuses on creep of four cast materials intended for exhaust manifolds in heavy-duty truck engines. Two of the materials are ferritic ductile cast irons, SiMo51 and SiMo1000, one is an austenitic ductile cast iron, D5S, and another one is an austenitic cast steel, HK30. LÄS MER

3. 2. Thermal Cycling, Creep- and Tensile Testing of Cast Exhaust Materials at Elevated Temperatures

   Författare :Christian Öberg; Stefan Jonsson; Henrik Östling; KTH; []
   Nyckelord :creep; constant-load; thermal cycling; tensile test; cast materials; cast iron; exhaust materials.; Teknisk materialvetenskap; Materials Science and Engineering;

   Sammanfattning : An exhaust manifold of a truck engine is subjected to tough conditions. As the truck is started, operated and shut down, it becomes subjected to thermal cycling up to around 800°C. At such high temperatures, corrosion, fatigue and creep are active degradation mechanisms. LÄS MER

4. 3. Platforms in Liquid Modernity : Essays about the Sharing Economy, Digital Platforms, and Institutions

   Författare :Andrea Geissinger; Christina Öberg; Christofer Laurell; Christian Sandström; Robin Teigland; Örebro universitet; []
   Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; sharing economy; digital platforms; institutional theory; institutional logics; social ordering; Social Media Analytics; community; liquid modernity; interregnum; in-betweenness;

   Sammanfattning : The year 2020 feels like the beginning of a crescendo of change. As environmental and social challenges reach an all-time high, the organization of our societies is coming under scrutiny. We, as a society, turn to technology to reinvent the organization of social life after disruptive episodes. LÄS MER

5. 4. Pelvic Girdle Pain and Lumbar Pain in relation to pregnancy

   Författare :Annelie Gutke; Birgitta Öberg; Hans Christian Östgaard; Karin Harms-Ringdahl; Linköpings universitet; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Pelvic girdle pain; lumbar pain; pregnancy; health; functioning; postpartum depressive symptoms; low back pain; muscle function; gait; pregnancy-related; low back pain; course; predictors; recovery; persistent; muscle endurance; Physiotherapy; Sjukgymnastik fysioterapi;

   Sammanfattning : The prevalence of low back pain (LBP) is higher in pregnant women compared to women of the same age in a general population. Pregnancy-related LBP persists 6 years after pregnancy in 16% of women. Consequently, pregnancy represents a specific risk for LBP and persistent LBP. LÄS MER

7. 5. Essays on the interaction between regulation and technology : Understanding agency and context through multiple levels of inquiry

   Författare :Rasmus Nykvist; Christina Öberg; Mirko Ernkvist; Christian Sandström; Lars Engwall; Örebro universitet; []
   Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; Institutional Entrepreneurship; Technological Transformation; Regulation; Historical Methods; Stockholm Stock Exchange;

   Sammanfattning : A key challenge for implementing pioneering regulatory and technological change includes overcoming regulatory constraints and resistance from vested interest groups in favor of the status quo. This is a compilation dissertation comprising five papers and one covering paper that aims to describe and explain the interaction between agency and context under conditions of combined technological and regulatory change through multiple levels of inquiry. LÄS MER