Search for dissertations about: "External perturbations"

Showing result 1 - 5 of 41 swedish dissertations containing the words External perturbations.

2. 1. Tearing mode dynamics in the presence of resonant magnetic perturbations

   Author : Richard Fridström; Per Brunsell; Marco Cecconello; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Tearing mode; plasma; fusion; reversed-field pinch; RFP; magnetic; confinement; resonant; perturbation; magnetohydrodynamics; MHD; EXTRAP T2R; Madison Symmetic Torus; Fysik; Physics;

   Abstract : Magnetically confined fusion (MCF) plasmas are typically subject to several unstable modes. The growth of one mode can limit the plasma energy confinement and might cause a termination of the plasma. Externally applied resonant magnetic perturbations (RMPs) are used to control and to mitigate some of the unstable modes. READ MORE

4. 2. Strongly non-linear magnetization dynamics in nano-structures: perturbations, multi-mode generation, and topological droplets

   Author : Ezio Iacocca; Göteborgs universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Spin torque oscillators; Spintronics; Spintronics;

   Abstract : Spin torque oscillators (STOs) are magnetic nano-devices in which strongly non-linear magnetodynamic phenomena can be excited by current. In this thesis, we study some of these phenomena by means of micromagnetic simulations, analytical calculations, and electrical characterization. Three main subjects are discussed: 1. READ MORE

5. 3. Dosimetry Studies of Different Radiotherapy Applications using Monte Carlo Radiation Transport Calculations

   Author : Shirin Abbasinejad Enger; Hans Lundqvist; Anders Ahnesjö; Irena Gudowska; Uppsala universitet; []
   Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; External Beam Radiotherapy; Gadolinium Neutron Capture Therapy; Gadolinium Neutron Capture Brachytherapy; Targeted Radionuclide therapy; Detector Response Modelling; Monte Carlo Simulation.; Radiological physics; Radiofysik;

   Abstract : Developing radiation delivery systems for optimisation of absorbed dose to the target without normal tissue toxicity requires advanced calculations for transport of radiation. In this thesis absorbed dose and fluence in different radiotherapy applications were calculated by using Monte Carlo (MC) simulations. READ MORE

6. 4. Symmetry-protected topological phases: From Floquet theory to machine learning

   Author : Oleksandr Balabanov; Göteborgs universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Topological quantum matter; neural networks; Floquet theory;

   Abstract : It is by now a well known fact that boundary states in conventional time-independent topological insulators are protected against perturbations that preserve relevant symmetries. In the first part of this thesis, accompanying Papers A - C, we study how this robustness extends to time-periodic (Floquet) topological insulators. READ MORE

7. 5. Analysis of Adaptation in Human Postural Control

   Author : Per-Anders Fransson; Lund näs- och halssjukdomar Öron-; []
   Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Physical medicine; kinesitherapy; revalidation; rehabilitation; Rehabilitering medicinsk och social ; Adaptation; Postural control; Proprioception; Vestibular; Posturography; neuropsykologi; Neurologi; neurophysiology; neuropsychology; Neurology; hörsel- och talorganen; audiologi; Otorinolaryngologi; auditive system and speech; audiology; Otorhinolaryngology; Movement pattern; Sensorimotor integration; Muscle fatigue; Age; Cutaneous sensation; neurofysiologi;

   Abstract : The ability to obtain correct balance control information and adjust motor performance appropriately are essential elements in effective postural control. However, functional disorders may affect the reliability of receptor information and ability to carry out corrective motions needed to maintain balance. READ MORE