Sökning: "nonlinear waves"

Visar resultat 1 - 5 av 127 avhandlingar innehållade orden nonlinear waves.

1. 1. Transient Electromagnetic Waves in Nonlinear Media

   Författare :Daniel Sjöberg; Institutionen för elektro- och informationsteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Signal processing; nonlinear materials; Electromagnetic waves; instantaneous response; waveguides; shock waves; entropy condition; Elektronik och elektroteknik; Electronics and Electrical technology; Signalbehandling; Electromagnetism; optics; acoustics; Elektromagnetism; optik; akustik;

   Sammanfattning : This thesis is concerned with the propagation of transient electromagnetic waves in nonlinear media. It consists of a General Introduction and five scientific papers. The General Introduction gives a broad overview of nonlinear electromagnetic phenomena. LÄS MER

3. 2. On steady waves in two-layer fluids and ferrofluids

   Författare :Dag Nilsson; Partiella differentialekvationer; []
   Nyckelord :Internal waves; ferrofluids; partial differential equation; nonlinear waves; travelling waves; solitary waves; dynamical systems; Hamiltonian systems; non-local equations;

   Sammanfattning : This thesis concerns travelling waves in a two-layer fluid and on a ferrofluid jet. We prove existence of several types of such waves by reformulating the corresponding governing equation as an infinite dimensional dynamical system, where an unbounded spatial coordinate is used as time. LÄS MER

4. 3. Nonlinear interaction and propagation of gravitational and electromagnetic waves in plasmas

   Författare :Martin Servin; Gert Brodin; Lennart Stenflo; Demetrios Papadopoulos; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Theoretical physics; general relativity; plasma; gravitational waves; electromagnetic waves; nonlinear; wave interaction; wave propagation; Teoretisk fysik; Physics; Fysik; teoretisk fysik; Theoretical Physics;

   Sammanfattning : Gravitational waves and electromagnetic waves are important as carriers of energy and information. This thesis is devoted to the study of the propagation and interaction of these waves in plasmas, with emphasis on nonlinear effects and applications within astrophysics. LÄS MER

5. 4. Steady waves in local and nonlocal models for water waves

   Författare :Tien Truong; Matematik (naturvetenskapliga fakulteten); []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; The steady Euler equations; the Whitham equation; solitary waves; highest waves; periodic waves; transverse dynamics; The steady Euler equations; the Whitham equation; solitary waves; highest waves; periodic waves; transverse dynamics;

   Sammanfattning : We study the steady Euler equations for inviscid, incompressible, and irrotational water waves of constant density. The thesis consists of three papers. The first paper approaches the Euler equations through a famous nonlocal model equation for gravity waves, namely the Whitham equation. LÄS MER

7. 5. 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