Sökning: "electromagnetic anisotropy"

Visar resultat 1 - 5 av 19 avhandlingar innehållade orden electromagnetic anisotropy.

  1. 1. 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. 2. Characterization of Hydrogeological Media Using Electromagnetic Geophysics

    Författare :Niklas Linde; Laust B. Pedersen; Max A. Meju; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Geophysics; Hydrogeophysics; radio magnetotellurics; ground penetrating radar; electrical resistance tomography; inversion; regularization; geostatistics; electrical anisotropy; fractured rock; Geofysik; Geophysics; Geofysik;

    Sammanfattning : Radio magnetotellurics (RMT), crosshole ground penetrating radar (GPR), and crosshole electrical resistance tomography (ERT) were applied in a range of hydrogeological applications where geophysical data could improve hydrogeological characterization. A profile of RMT data collected over highly resistive granite was used to map subhorizontal fracture zones below 300m depth, as well as a steeply dipping fracture zone, which was also observed on a coinciding seismic reflection profile. LÄS MER

  4. 3. Electromagnetic Modelling for the Estimation of Wood Parameters

    Författare :Therese Sjödén; Sven Nordebo; Börje Nilsson; Andreas Fhager; Växjö universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Cramér Rao bound; electromagnetic modelling; estimation; grain angle; microwave; wood properties.; Cramér Rao-gräns; elektromagnetisk modellering; estimering; fibervinkel; mikrovågor; träegenskaper.; Engineering physics; Teknisk fysik; Physics; Fysik;

    Sammanfattning : Spiral grain in trees causes trouble to the wood industry, since boards sawn from trees with large grain angle have severe problems with form stability. Measurements of the grain angle under bark enable the optimisation of the refining process. LÄS MER

  5. 4. Molecular electronic,  vibrational and rotational motion in optical and x-ray fields

    Författare :Sergey Gavrilyuk; Faris Gelmukhanov; Stephane Carniato; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; x-ray; nonlinear optics; photobleaching; recoil; anisotropy; Auger; Chemical physics; Kemisk fysik;

    Sammanfattning : The subject of this theoretical  study is the role ofelectronic structure as well as of rotational and vibrational motionson interactions between molecules and electromagnetic radiation,ranging from optical to x-ray. The thesis concerns both linear and nonlinear regimes of the light-matter interaction. LÄS MER

  7. 5. A Broad View on the Interpretation of Electromagnetic Data (VLF, RMT, MT, CSTMT)

    Författare :Behrooz Oskooi; Laust Börsting Pedersen; Thorkild Mack Rasmussen; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Geophysics; Airborne; azimuthal anisotropy; CSTMT; distortion; EM; geothermal; Hengill; mineralization; MT; peaker; resolution; RMT; tipper; tensor VLF; VLF; Geofysik; Geophysics; Geofysik;

    Sammanfattning : The resolution power of single Very Low Frequency (VLF) data and multi-frequency Radiomagnetotelluric (RMT) data in delineating conductive structures typical for the sedimentary cover and crystalline basement in Scandinavia is studied with a view to future developments of the technique to increasing the frequency range into the LW radio band. Airborne and ground VLF data are interpreted and correlated with RMT measurements made on the ground to better understand the resolution power of VLF data. LÄS MER