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Visar resultat 1 - 5 av 55 avhandlingar som matchar ovanstående sökkriterier.

1. 1. Hydropower generator and power system interaction

   Författare :Johan Bladh; Urban Lundin; Rafael Escarela-Perez; Uppsala universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Amortisseur windings; applied voltage test; automatic voltage regulators; damper windings; damping torque; empirical modelling; equivalent circuits; excitation control; finite element method; hydropower generators; power system restoration; power system stability; synchronous machines; self excitation; shaft torque amplification; short circuit test; single machine infinite bus; slip test; standstill frequency response test; subsynchronous oscillations; synchronising torque; synchronous generators; torsional interaction.; Engineering Science with specialization in Science of Electricity; Teknisk fysik med inriktning mot elektricitetslära;

   Sammanfattning : After decades of routine operation, the hydropower industry faces new challenges. Large-scale integration of other renewable sources of generation in the power system accentuates the role of hydropower as a regulating resource. LÄS MER

3. 2. The effect of anti-slip devices on pedestrian safety : method development and practical test

   Författare :Glenn Berggård; Christer Hydén; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Traffic Engineering; Trafikteknik;

   Sammanfattning : Every winter, more than 100,000 pedestrians in the Nordic countries receive medical treatment as a result of falls on slippery surfaces. In addition, the risk of injury reduces interest in outdoor activities during the wintertime. LÄS MER

4. 3. Tensile fracture of ice : test methods and fracture mechanics analysis

   Författare :Lars Stehn; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Structural Engineering; Konstruktionsteknik;

   Sammanfattning : This thesis is concerned with several aspects of fracture of both brackish (low salinity) sea ice and freshwater ice. The tests and analyses are confined to tensile, or in fracture mechanics language, Mode I, fracture. LÄS MER

5. 4. Wet clutch tribology : friction characteristics in limited slip differentials

   Författare :Rikard Mäki; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Maskinelement; Machine Elements;

   Sammanfattning : In recent years, electronically controlled automotive transmission systems, where wet clutches are used as intelligent differentials, have appeared in the market. These applications impose great demands on the transmission fluids and friction materials used as well as on controllability and vibration preventive (anti-shudder) properties of the clutch systems. LÄS MER

7. 5. Effects of Steel Fibres on Cracking in Reinforced Concrete

   Författare :Anette M Jansson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; uniaxial tension test; Keywords: Self-compacting; characteristic crack width; fibre-reinforced; bond; tension stiffening; Digital Image Correlation; pull-out test;

   Sammanfattning : ABSTRACTAlthough it is well known that fibre reinforcement acts as a crack arresting agent, there is still a need for deeper knowledge of the actual cracking behaviour, especially regarding cracks with widths smaller than 0.3mm. LÄS MER