Sökning: "Spectral stability"

Visar resultat 11 - 15 av 87 avhandlingar innehållade orden Spectral stability.

1. 11. Spectral Control of Functional Fiber Sources

   Författare :Robert Lindberg; Valdas Pasiskevicius; Stefano Taccheo; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Optics and Photonics; Optik och fotonik;

   Sammanfattning : This thesis is based on five projects aimed at spectral control of fiber-based laser architectures. Two of these concern electrically wavelength-tunable laser sources, namely a fiber amplifier system for CO2-monitoring and a novel tunable laser design for flexible pulsed operation. LÄS MER

3. 12. Studies on instability and optimal forcing of incompressible flows

   Författare :Mattias Brynjell-Rahkola; Dan S. Henningson; Ardeshir Hanifi; Philipp Schlatter; François Gallaire; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; hydrodynamic stability; optimal forcing; resolvent operator; Laplace preconditioner; spectral element method; eigenvalue problems; inverse power method; direct numerical simulations; Falkner–Skan–Cooke boundary layer; localized roughness; crossflow vortices; Blasius boundary layer; localized suction; helical vortices; lid-driven cavity; cylinder flow; Teknisk mekanik; Engineering Mechanics;

   Sammanfattning : This thesis considers the hydrodynamic instability and optimal forcing of a number of incompressible flow cases. In the first part, the instabilities of three problems that are of great interest in energy and aerospace applications are studied, namely a Blasius boundary layer subject to localized wall-suction, a Falkner–Skan–Cooke boundary layer with a localized surface roughness, and a pair of helical vortices. LÄS MER

4. 13. Nucleic Acids as Drug Targets - Influence of Platinum Complexes on Duplex Stability and Binding Kinetics

   Författare :Christopher Polonyi; Biokemi och Strukturbiologi; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Anticancer drugs; platinum complexes; cisplatin; oxaliplatin; nucleic acid; RNA; DNA; duplex melting; thermodynamic stability; kinetics; non-coding RNA; miRNA; siRNA; wobble base pair; loop; BRCA1; mimic; luciferase assay;

   Sammanfattning : Gaining a detailed understanding of how human cells are affected by metal-based drugs is crucial, since these drugs have shown great potential in cancer treatment. Cisplatin is used to treat many different types of cancer, e.g. testicular, ovarian, melanoma, bladder, non-small cell lung cancer, small cell lung cancer, myelomas and lymphomas. LÄS MER

5. 14. A sub-5 fs 100 TW optical parametric synthesizer

   Författare :Peter Fischer; Laszlo Veisz; Ove Axner; Cord L. Arnold; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Optical parametric amplification OPA ; optical parametric synthesizer OPS optimization; energy stability; carrier envelop phase stability; temporal intensity contrast; saturation; fewcycle; tera watt; fysik; Physics;

   Sammanfattning : State-of-the-art ultrashort light sources in the visible and near-infrared spectral regions provide direct access to the femtosecond realm, thereby enabling understanding and control of electronic processes within matter. On the other hand, ultra-intense light pulses lead to the emergence of relativistic electron motion and many related phenomena, such as electron & ion acceleration and high-order harmonic generation in plasmas. LÄS MER

7. 15. Stability and Exponential Convergence for the Boltzmann Equation

   Författare :Bernt Wennberg; Göteborgs universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : This thesis is devoted to the long-time behaviour of the nonlinear Boltzmann equation for a class of molecular interactions, including inverse power laws for hard potentials. It has been known for some time now, that under natural conditions on the initial data, the space homogeneous Boltzmann equation possesses a unique, global solution, and that this solution tends strongly to the equilibrium distribution as time tends to infinity. LÄS MER