Sökning: "dispersion relation"

Visar resultat 1 - 5 av 79 avhandlingar innehållade orden dispersion relation.

  1. 1. Electromagnetic Dispersion Modeling and Analysis for Power Cables

    Författare :Stefan Gustafsson; Sven Nordebo; Alexander Nosich; Linnéuniversitetet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; power cable; electromagnetic model; dispersion relation; asymptotic analysis; sensitivity analysis;

    Sammanfattning : This thesis addresses electromagnetic wave propagation in power cables. It consists of five papers, where the three first papers are based on one and the same model, and the last two papers are based on a similar but slightly different model. LÄS MER

  3. 2. First-principles calculations of long-range intermolecular dispersion forces

    Författare :Auayporn Jiemchooroj; Bo E. Sernelius; Irina Yakimenko; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; van der Waals forces; dispersion forces; intermolecular interactions; dispersion coefficients; polarizability; Physics; Fysik;

    Sammanfattning : This work presents first-principles calculations of long-range intermolecular dispersion energies between two atoms or molecules as expressed in terms of the C6 dipole-dipole dispersion coefficients. In a series of publications, it has been shown by us that the complex linear polarization propagator method provides accurate ab initio and first-principles density functional theory values of the C6 dispersion coefficients in comparison with those reported in the literature. LÄS MER

  4. 3. Electromagnetic dispersion modeling and analysis for HVDC power cables

    Författare :Stefan Gustafsson; Sven Nordebo; Martin Norgren; Linnéuniversitetet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; HVDC power cables; electromagnetic model; TDR measurement; sensitivity analysis; dispersion relation; propagation constant; low-frequency asymptotics;

    Sammanfattning : Derivation of an electromagnetic model, regarding the wave propagation in a very long (10 km or more) High Voltage Direct Current (HVDC) power cable, is the central part of this thesis. With an existing “perfect” electromagnetic model there are potentially a wide range of applications. LÄS MER

  5. 4. Error analysis of summation-by-parts formulations : Dispersion, transmission and accuracy

    Författare :Viktor Linders; Jan Nordström; Marco Kupiainen; Mark Carpenter; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : In this thesis we consider errors arising from finite difference operators on summation-by-parts (SBP) form, used in the discretisation of partial differential equations. The SBP operators are augmented with simultaneous-approximation-terms (SATs) to weakly impose boundary conditions. LÄS MER

  7. 5. A Method for Dispersive Split Hopkinson Pressure Bar Analysis Applied to High Strain Rate Testing of Spruce Wood

    Författare :Svante Widehammar; Karl-Gustav Sundin; Uppsala universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Materials science; split Hopkinson; wave propagation; dispersion; Hamilton s principle; strain rate; calibration; spruce; wood; Materialvetenskap; Materials science; Teknisk materialvetenskap; teknisk fysik med inriktning mot hållfasthetslära; Technical Physics;

    Sammanfattning : En metod för dispersiv analys av försök med delad hopkinsonstång tillämpad på provning av granved vid hög töjningshastighetSyftet var att etablera en metod för att studera sambandet mellan spänning och töjning för granved vid hög töjningshastighet. Detta åstadkoms genom att anpassa och något vidareutveckla tekniken med delad hopkinsonstång ("Split Hopkinson Pressure Bar", SHPB). LÄS MER