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Visar resultat 1 - 5 av 141 avhandlingar som matchar ovanstående sökkriterier.

1. 1. Dislocations in silicon

   Författare :Niklas Lehto; Luleå tekniska universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Fysik; Fysik;

   Sammanfattning : The topic of this thesis is theoretical studies of the electrical and structural properties in the elemental semiconductor silicon. Because of the numerous and powerful applications of semiconductors, e.g., rectifiers, transistors, solar cells and lasers, they have been the focus of huge amounts of research. LÄS MER

3. 2. Dislocation et référence aux entités en français L2 : Développement, interaction, variation

   Författare :Hugues Engel; Inge Bartning; Henriëtte Hendriks; Stockholms universitet; []
   Nyckelord :HUMANIORA; HUMANITIES; Dislocations; second language acquisition; spoken French L1 and L2; oral speech; development; acquisitional stages; use; input; information structure; task-induced variation; interaction; French language; Franska språket; French; franska;

   Sammanfattning : This thesis investigates the use and development of dislocations in oral productions by Swedish users of French as a second language (L2). Dislocations are highly frequent in French oral speech and play an essential role in building utterances. LÄS MER

4. 3. Numerical Modeling of Plasticity in FCC Crystalline Materials Using Discrete Dislocation Dynamics

   Författare :Arash Hosseinzadeh Delandar; Pavel Korzhavyi; Rolf Sandström; Mikko Alava; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Dislocations; crystal plasticity; discrete dislocation dynamics; Cu single crystal; high strain rate deformation; strain rate sensitivity; plastic anisotropy; slip band formation; Teknisk materialvetenskap; Materials Science and Engineering;

   Sammanfattning : Plasticity in crystalline solids is controlled by the microscopic line defects known as “dislocations”. Decisive role of dislocations in crystal plasticity in addition to fundamentals of plastic deformation are presented in the current thesis work. LÄS MER

5. 4. Modelling and simulation of short fatigue cracks

   Författare :Christina Bjerkén; Materialteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; materialteknik; Materiallära; Material technology; Interface cracks; Dislocations; Short cracks; Local plasticity;

   Sammanfattning : The growth of short fatigue cracks deviates from the behaviour of long fatigue cracks even if subjected to the same nominal driving force. The influence from the microstructure is pronounced, while crack closure effects may not be that important as for longer cracks. LÄS MER

7. 5. Microstructural Decay in High-Strength Bearing Steels under Rolling Contact Fatigue

   Författare :Tania Loaiza; Peter Hedström; Mårten Olsson; Steve Ooi; Prasath Babu; Harry Bhadeshia; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Microstructural decay; microscopy; rolling contact fatigue; Hybrid 60 steel; Bearing steel; 52100; dislocations; ferrite microbands; Mikrostrukturell nedbrytning; mikroskopi; rullande kontaktfatigue; Hybrid 60-stål; dislokationer; Materials Science and Engineering; Teknisk materialvetenskap;

   Sammanfattning : The work presented in this thesis aims to enhance our understanding of material decay in high-strength steels used for bearing applications. The primary objective is to investigate the microstructural changes in two high-strength steels: 52100 steels, a popular bearing steel, and Hybrid 60, a relatively new bearing steel designed for long fatigue life and use at elevated temperatures. LÄS MER