Sökning: "tension zone"

Visar resultat 1 - 5 av 36 avhandlingar innehållade orden tension zone.

1. 1. Hybrid zone dynamics, assortative mating, and migratory programmes in a willow warbler migratory divide

   Författare :Keith W. Larson; Susanne Åkesson; Staffan Bensch; Martin Schaefer; Biologiska institutionen; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; migratory divide; phenotype; willow warbler; hybrid zone; tension zone; Phylloscopus trochilus; migratype; assortative mating; migration; biology; biologi; evolutionär genetik; evolutionary genetics; migratory divide; phenotype; willow warbler; hybrid zone; tension zone; Phylloscopus trochilus; migratype; assortative mating; migration;

   Sammanfattning : In this thesis I will compare and contrast the two willow warbler subspecies (Phylloscopus trochilus trochilus and P. t. acredula) with differing migratory phenotypes (or "migratype") in the context of their migratory divide and hybrid zone in central Sweden. Their migratory programs differ in the direction and distance traveled during migration. LÄS MER

3. 2. Behaviour of fracture process zones in concrete influenced by simultaneously applied normal and shear displacements

   Författare :Manouchehr Hassanzadeh; Avdelningen för Byggnadsmaterial; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; softening; mixed mode; fictitious crack model; concrete; deformationer; betong; brottmekanik; hållfasthet; brotthållfasthet; spänningar; skjuvspänningar; sprickor; beräkningsmodeller; brottenergi; teori; laboratorieförsök; interlock; crack path; diagonal crack; microcracking; instability; fracture energy; fracture mechanics; shear; tension; process zone;

   Sammanfattning : The thesis deals with the determination of the post peak behaviour of concrete in pure tension, and combined tension (compression) and shear. A test arrangement has been developed in order to determine the post peak behaviour of concrete expressed as stress - displacement curves. LÄS MER

4. 3. Melt convection in welding and crystal growth

   Författare :Minh Do-Quang; Gustav Amberg; Andreas Ludwig; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Engineering physics; thermocapillary convection; gas-tungsten arc welding; floating zone; parallel computing; finite element method; Teknisk fysik; Engineering physics; Teknisk fysik;

   Sammanfattning : A parallel finite element code with adaptive meshing was developed and used to study three dimensional, time-dependent fluid flows caused by thermocapillary convection as well as temperature and dopant distribution in fusion welding and floating zone crystal growth. A comprehensive numerical model of the three dimensional time-dependent fluid flows in a weld pool had been developed. LÄS MER

5. 4. Behaviour of blast-induced damaged zone around underground excavations in hard rock mass

   Författare :David Saiang; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Mining and Rock Engineering; Gruv- och berganläggningsteknik;

   Sammanfattning : The presence of blast-induced damaged zone around an excavation boundary has been an important concern in rock construction. It is generally believed that the presence of this zone can pose problems related to stability and flow and consequently impair the performance and functionality of the excavation. LÄS MER

7. 5. Mechanical behaviour of a roller bearing steel : Strength differential effect, low temperature creep and propagation of short cracks

   Författare :Irene Linares Arregui; Bo Alfredsson; Nils-Gunnar Ohlson; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Sammanfattning : Fatigue cracks in bearings either initiate from the surface or from an inclusion below the rolling contact surface. Then, short cracks start to propagate. Short crack grow at considerably faster rates than long cracks subjected to a nominally equivalent stress intensity factor range. LÄS MER