Search for dissertations about: "coherent structure"

Showing result 1 - 5 of 131 swedish dissertations containing the words coherent structure.

  1. 1. Magnetism and Structure in Metallic Multilayers

    University dissertation from Uppsala : Acta Universitatis Upsaliensis

    Author : Erik Holmström; Uppsala universitet.; [2003]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Physics; Magnetism; Interfaces; Structure; KKR-ASA; CPA; Quantum Well; Fysik; NATURAL SCIENCES Physics; NATURVETENSKAP Fysik;

    Abstract : The interplay between magnetism and structure has been studied in magnetic multilayers by electronic structure calculations based on density functional theory and analyzed in terms of models. The main ideas behind the Korringa-Kohn-Rostocker Green’s function method are described and the implementation of the coherent potential approximation is outlined. READ MORE

  2. 2. Analysis of Turbulent Flows-From Chaos to Structure

    University dissertation from Uppsala : Acta Universitatis Upsaliensis

    Author : Farideh Ghasempour; [2012]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Large Eddy Simulation; Vortex dynamics; Turbulence; Flow visualization; Vortex statistics; Coherent structure;

    Abstract : The development of models for several phenomena occurring in turbulent single and multi-phase flows requires improved description and quantification of turbulent structures. Phenomena such as, for example, mixing, coalescence and break-up, are often fast and nonlinear. READ MORE

  3. 3. Propagation of some coherent and partially coherent laser beams

    University dissertation from Stockholm : KTH

    Author : Yangjian Cai; KTH.; [2006]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; : dark hollow beam; elliptical Gaussian beam; flat-topped beam; twisted anisotropic Gaussian Schell-model; partial coherent; propagation; paraxial optical system; TECHNOLOGY Electrical engineering; electronics and photonics; TEKNIKVETENSKAP Elektroteknik; elektronik och fotonik;

    Abstract : In this thesis, we investigate the propagation of some coherent and partially coherent laser beams, including a dark hollow beam (DHB), an elliptical Gaussian beam (EGB), a flat-topped beam and a twisted anisotropic Gaussian Schell-model (TAGSM) beam, through a paraxial optical system or a turbulent atmosphere. Several theoretical models are proposed to describe a DHB of circular or non-circular symmetry. READ MORE

  4. 4. Coherent Optical Transmission Systems Performance and Coding Aspects

    University dissertation from Stockholm : KTH Royal Institute of Technology

    Author : Miu Yoong Leong; KTH.; [2015]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Abstract : Since the invention of fiber-optic systems in the 1970s, user demand has driven innovation forward, and each new generation of products has achieved higher data rates than its predecessor. Today, the most promising approach for further increasing data rates is coherent transmission with multi-level modulation and digital signal processing (DSP). READ MORE

  5. 5. Sunspot structure and dynamics

    University dissertation from Stockholm : Department of Astronomy, Stockholm University

    Author : Luc Rouppe van der Voort; Stockholms universitet.; Stockholms universitet.; [2003]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURAL SCIENCES Physics Astronomy and astrophysics Astronomy; NATURVETENSKAP Fysik Astronomi och astrofysik Astronomi; Astronomy; astronomi;

    Abstract : Fundamental physical processes occur on small spatial scales in the solar atmosphere and high-spatial-resolution observations are necessary to test theoretical models. This thesis presents high-spatial-resolution observations of sunspots obtained with the Swedish solar telescopes on La Palma: the Swedish Vacuum Solar Telescope (SVST) and its successor the Swedish 1-m Solar Telescope (SST). READ MORE