Sökning: "low-frequency oscillations"

Visar resultat 1 - 5 av 18 avhandlingar innehållade orden low-frequency oscillations.

1. 1. Transient Stability in Low Frequency Railways with Mixed Electronic and Rotational Generation

   Författare :John Laury; Thorsten Schütte; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electric Power Engineering; Elkraftteknik;

   Sammanfattning : Transient stability concerns the ability of a power system to maintain synchronism after a large disturbance. Transient stability plays an important role in guaranteeing operational security and reliability and has been extensively studies for large 50 Hz and 60 Hz transmission systems. LÄS MER

3. 2. Stability and transition on wind turbine blades

   Författare :Thales Coelho Leite Fava; Ardeshir Hanifi; Dan Henningson; Stefania Cherubini; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Boundary layer stability; free-stream turbulence; laminar-turbulent transition; low-frequency oscillations; rotation effects; wind turbine blades.; Gränsskiktsstabilitet; friströmsturbulens; laminär-turbulent omslag; lågfrekventa svängningar; rotationseffekter; vindkraftverksblad.; Teknisk mekanik; Engineering Mechanics;

   Sammanfattning : Transition on wind turbine blades is a highly complex phenomenon due to the myriad effects influencing the process. This thesis studies some of them, namely free-stream turbulence (FST), rotation, and three-dimensionality. The investigations employ large eddy simulations (LES) with and without (implicit or wall-resolved LES) a subgrid-scale model. LÄS MER

4. 3. Nonlinear Dust Particle Dynamics and Collective Effects in Complex Plasmas

   Författare :Gianfranco Sorasio; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physics; Complex Dusty Plasmas; Self excited; Nonlinear; Forced Oscillations; Electrostatic Instabilities in current-carrying magnetoplasmas; Cross-field instabilities in magnetized dusty plasmas; Dust Acoustic Waves; Electrostatic Dust Cyclotron Waves; Fysik; Physics; Fysik; fysik; Physics;

   Sammanfattning : Theoretical studies of dusty plasmas have been performed by focusing attention principally on collective phenomena and on grain motion. This thesis consists of a collection of seven published papers that explore both the collective behavior of a complex plasma system as well as the dynamics of grains in plasmas. LÄS MER

5. 4. Untangling Cortico-Striatal Circuitry and its Role in Health and Disease - A computational investigation

   Författare :Jovana Belic; Jeanette Hellgren Kotaleski; Arvind Kumar; Abigail Morrison; Arthur Leblois; KTH; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; cortico-striatal circuits; levodopa-induced dyskinesia; Parkinson’s disease; effective connectivity; cross-frequency coupling; corticostriatal network; network oscillations; GABAergic transmission. basal ganglia; striatum; cortex; fast spiking interneurons; medium spiny neurons; neuronal avalanches;

   Sammanfattning : The basal ganglia (BG) play a critical role in a variety of regular motor and cognitive functions. Many brain diseases, such as Parkinson’s diseases, Huntington’s disease and dyskinesia, are directly related to malfunctions of the BG nuclei. LÄS MER

7. 5. Quantum Coherence in the Single Cooper Pair Box

   Författare :Kevin Bladh; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; coherent oscillations; single Cooper pair box; quantum coherence; radio frequency single electron transistor; cryogenic filters;

   Sammanfattning : This thesis presents measurements of quantum coherence in a single Cooper pair box, where quantum oscillations of charge between a reservoir and a small superconducting island have been observed. The single Cooper pair box (SCB) consists of a small metallic island which is connected to a reservoir via a tunnel junction. LÄS MER