Search for dissertations about: "waves"

Showing result 1 - 5 of 719 swedish dissertations containing the word waves.

  1. 1. On steady waves in two-layer fluids and ferrofluids

    University dissertation from Lund University, Faculty of Science, Centre for Mathematical Sciences

    Author : Dag Nilsson; Lund University.; Lunds universitet.; [2018]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Internal waves; ferrofluids; partial differential equation; nonlinear waves; travelling waves; solitary waves; dynamical systems; Hamiltonian systems; non-local equations;

    Abstract : 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. READ MORE

  2. 2. Ultrasonic Arrays for Sensing and Beamforming of Lamb Waves

    University dissertation from Uppsala : Acta Universitatis Upsaliensis

    Author : Marcus Engholm; Uppsala universitet.; [2010]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; imaging; array processing; guided waves; Lamb waves; dispersive waves; multi-modal waves; spatial filtering; mode suppression; resonant ultrasound; transducer design; direction of arrival estimation; adaptive beamforming; TECHNOLOGY Information technology Signal processing; TEKNIKVETENSKAP Informationsteknik Signalbehandling; TECHNOLOGY Electrical engineering; electronics and photonics Electronic measurement and instrumentation; TEKNIKVETENSKAP Elektroteknik; elektronik och fotonik Elektronisk mät- och apparatteknik;

    Abstract : Non-destructive testing (NDT) techniques are critical to ensure integrity and safety of engineered structures. Structural health monitoring (SHM) is considered as the next step in the field enabling continuous monitoring of structures. READ MORE

  3. 3. Waves in space plasmas Lower hybrid cavities and simple-pole distribution functions

    University dissertation from Uppsala : Acta Universitatis Upsaliensis

    Author : Anders Tjulin; Uppsala universitet.; [2003]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Space and plasma physics; space physics; plasma; waves; dispersion relations; lower hybrid cavities; Cluster; magnetosphere; Rymd- och plasmafysik; NATURAL SCIENCES Physics Geocosmophysics and plasma physics Space physics; NATURVETENSKAP Fysik Geokosmofysik och plasmafysik Rymdfysik;

    Abstract : Waves are a fundamental feature in many parts of physics, since they transport energy without transporting matter. This is the case also in space physics. Waves are responsible for energy transport both between different parts of space and between different particles in the space plasma. READ MORE

  4. 4. Interaction between Electromagnetic Waves and Localized Plasma Oscillations

    University dissertation from Uppsala : Acta Universitatis Upsaliensis

    Author : Jan-Ove Hall; Uppsala universitet.; [2004]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Space and plasma physics; space physics; plasma physics; radio waves; ionospheric modification; density depleations; field-aligned irregularities; lower hybrid solitary structures; lower hybrid cavities; Z mode waves; magnetosonic waves; scattering; mode conversion; Rymd- och plasmafysik; NATURAL SCIENCES Physics Geocosmophysics and plasma physics Space physics; NATURVETENSKAP Fysik Geokosmofysik och plasmafysik Rymdfysik;

    Abstract : This thesis treats interaction between electromagnetic waves and localized plasma oscillations. Two specific physical systems are considered, namely artificially excited magnetic field-aligned irregularities (striations) and naturally excited lower hybrid solitary structures (LHSS). READ MORE

  5. 5. Transient Electromagnetic Waves in Nonlinear Media

    University dissertation from Department of Electroscience, Lund University

    Author : Daniel Sjöberg; Lund University.; Lunds universitet.; [2001]
    Keywords : 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;

    Abstract : 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. READ MORE