Sökning: "wave splitting"

Visar resultat 6 - 10 av 43 avhandlingar innehållade orden wave splitting.

  1. 6. Directional Decomposition in Anisotropic Heterogeneous Media for Acoustic and Electromagnetic Fields

    Författare :B. Lars G. Jonsson; KTH; []
    Nyckelord :directional wave-field decomposition; wave splitting; spectral reduction; aourstic anisotropy; electromagnetic anisotropy; generalized eigenvalue problem;

    Sammanfattning : Directional wave-field decomposition for heterogeneousanisotropic media with in-stantaneous response is establishedfor both the acoustic and the electromagnetic equations.We derive a sufficient condition for ellipticity of thesystem's matrix in the Laplace domain and show that theconstruction of the splitting matrix via a Dunford-Taylorintegral over the resolvent of the non-compact, non-normalsystem's matrix is well de ned. LÄS MER

  3. 7. Transient waves in nonstationary media : with applications to lightning and nonlinear media

    Författare :Ingegerd Åberg; Institutionen för elektro- och informationsteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; lightning; Klein-Gordon; nonlinear; characteristics; wave splitting; imbedding; sources; propagators; Green functions; direct and inverse scattering; Nonstationary; transient; high-frequency switching; Kerr.; Technological sciences; Teknik;

    Sammanfattning : Propagation of transient waves in nonstationary, inhomogeneous, dispersive, stratified media is considered. Waves originating from sources exterior to the scatterer as well as from internal sources are treated. Algorithms are developed and illustrated by computations of wave phenomena in stationary, nonstationary and weakly nonlinear media. LÄS MER

  4. 8. Water splitting by heterogeneous catalysis

    Författare :Henrik Svengren; Mats Johnsson; Tomas Edvinsson; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Faradaic efficiency; electrocatalysis; electrolysis; water oxidation; hydrogen reduction; H2; O2; mass spectrometry; Inorganic Chemistry; oorganisk kemi;

    Sammanfattning : A sustainable solution for meeting the energy demands at our planet is by utilizing wind-, solar-, wave-, thermal-, biomass- and hydroelectric power. These renewable and CO2 emission-free energy sources are highly variable in terms of spatial and temporal availability over the Earth, introducing the need for an appropriate method of storing and carrying energy. LÄS MER

  5. 9. A Fast Method for Solving the Helmholtz Equation Based on Wave Splitting

    Författare :Jelena Popovic; Olof Runborg; Elisabeth Larsson; KTH; []
    Nyckelord :Helmholtz equation; high fequency waves;

    Sammanfattning : In this thesis, we propose and analyze a fast method for computing the solution of the Helmholtz equation in a bounded domain with a variable wave speed function. The method is based on wave splitting. The Helmholtz equation is first split into one--way wave equations which are then solved iteratively for a given tolerance. LÄS MER

  7. 10. Liquid Crystals in Guided Wave Optics

    Författare :Giusy Scalia; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; antiferroelectric liquid crystals; fully-leaky guided mode; ortho-conics; waveguide; liquid crystals; anisotropy;

    Sammanfattning : Liquid crystals are unique optical materials due to their large effective electrooptic and opto-optic coefficients. Currently, liquid crystals are primarily used in flat-panel dis-plays, but there is also an increasing number of nondisplay applications requiring new types of devices employing materials with unique optical properties. LÄS MER