Search for dissertations about: "Effective wave number"
Showing result 1 - 5 of 31 swedish dissertations containing the words Effective wave number.
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1. Thin Layers in Elastic Wave Propagation -Effective Modelling and Diffraction
Abstract : In the present thesis, the interest is focussed on the problem of effective modelling of thin interface layers for applications in elastic wave scattering. The layers are considered to be thin compared with wavelengths involved and it is shown that when all effects to lowest order in the layer thickness are included, we get boundary conditions (BCs) which have a number of nice features, including the one of implying that no scattering occurs when the layer has material parameters identical to the ones in the matrix medium. READ MORE
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2. Scattering of elastic waves by an anisotropic sphere
Abstract : Scattering of a plane wave by a single spherical obstacle is the archetype of many scattering problems in physics and geophysics. Spherical objects can provide a good approximation for many real objects, and the analytic formulation for a single sphere can be used to investigate wave propagation in more complicated structures like particle composites or grainy materials, which may have application in non-destructive testing, material characterization, medical ultrasound, etc. READ MORE
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3. Scattering of elastic waves by an anisotropic sphere with application to polycrystalline materials
Abstract : Scattering of a plane wave by a single spherical obstacle is the archetype of many scattering problems in various branches of physics. Spherical objects can provide a good approximation for many real objects, and the analytic formulation for a single sphere can be used to investigate wave propagation in more complex structures like particulate composites or grainy materials, which may have applications in non-destructive testing, material characterization, medical ultrasound, etc. READ MORE
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4. On millimeter and submillimeter wave focal plane arrays implemented with MEMS waveguide switches
Abstract : This thesis presents research towards enabling micromachined millimeter and submillimeter wave focal plane arrays (FPAs). The FPAs operate under the following principle: a switch network consisting of microelectromechanical (MEMS) switches, integrated with micromachined waveguides, is used to feed an array of antenna elements, located in the focal plane of a high-gain quasi-optical system. READ MORE
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5. Liquid Crystals in Guided Wave Optics
Abstract : 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. READ MORE