Sökning: "phase jump method"

Visar resultat 1 - 5 av 16 avhandlingar innehållade orden phase jump method.

1. 1. Two Problems in non-linear PDE’s with Phase Transitions

   Författare :Karl Jonsson; Henrik Shahgholian; Tomas Sjödin; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Conductivity jump; Free boundary problem; Quasilinear elliptic equation; Mathematical techniques; Nonlinear analysis; Free boundary; Free-boundary problems; Quasi-linear elliptic; Quasilinear elliptic equations; Hele-Shaw flow; non-local; implicit function theorem; Heterogeneous Multi Scale; HMM; Finite Element; FEM; FE; Mathematics; Matematik;

   Sammanfattning : This thesis is in the field of non-linear partial differential equations (PDE), focusing on problems which show some type of phase-transition. A single phase Hele-Shaw flow models a Newtoninan fluid which is being injected in the space between two narrowly separated parallel planes. LÄS MER

3. 2. Efficiency Enhancement Techniques for Free-Electron Lasers

   Författare :Alan Mak; Lunds universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; free-electron laser; accelerator physics; efficiency enhancement; undulator tapering; phase jump method; synchrotron radiation; Fysicumarkivet:2017:Mak;

   Sammanfattning : The central question addressed in this thesis is how to make the free-electron laser (FEL) more efficient. In recent years, coherent diffraction imaging provides an important motivation for efficiency enhancement. This is because a more efficient FEL process enables converting a larger fraction of the electron beam's power into optical power. LÄS MER

4. 3. Some Extensions of Fractional Ornstein-Uhlenbeck Model : Arbitrage and Other Applications

   Författare :José Igor Morlanes; Andriy Andreev; Hans Nyquist; Henrik Hult; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; fractional Ornstein-Uhlenbeck process; insider information; simulation embedding method; jump times; least-squares estimator; likelihood process; Ito calculus; Malliavin calculus; stochastic calculus; Statistics; statistik;

   Sammanfattning : This doctoral thesis endeavors to extend probability and statistical models using stochastic differential equations. The described models capture essential features from data that are not explained by classical diffusion models driven by Brownian motion.New results obtained by the author are presented in five articles. LÄS MER

5. 4. Numerical Solution Methods in Stochastic Chemical Kinetics

   Författare :Stefan Engblom; Per Lötstedt; Wilhelm Huisinga; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; stochastic models; chemical master equation; mesoscopic kinetics; Markov property; jump process; moment closure problem; spectral-Galerkin method; high dimensional problem; hybrid methods; time-parallel; homogenization; Beräkningsvetenskap med inriktning mot numerisk analys; Scientific Computing with specialization in Numerical Analysis;

   Sammanfattning : This study is concerned with the numerical solution of certain stochastic models of chemical reactions. Such descriptions have been shown to be useful tools when studying biochemical processes inside living cells where classical deterministic rate equations fail to reproduce actual behavior. LÄS MER

7. 5. Structural Changes in Nonionic Surfactant Systems

   Författare :Sanja Bulut; Fysikalisk kemi; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Vesicles; Nonionic Surfactant; Wormlike Micelles; Lamellar Phase; NMR; MRI; SLS; DLS; cryo-fracture-TEM; centrifugation; cryo-TEM;

   Sammanfattning : In this thesis we have studied structural changes of a nonionic surfactant self-assembly, as governed by changes in temperature and concentration. The techniques used in experimental investigations were dynamic and static light scattering, nuclear magnetic resonance and cryo-transmission electron microscopy (using a novel specimen preparation protocol). LÄS MER