Sökning: "Resonance frequencies"

Visar resultat 1 - 5 av 123 avhandlingar innehållade orden Resonance frequencies.

  1. 1. Broadband Ferromagnetic Resonance Spectrometer : Instrument and Applications

    Författare :Vasyl Denysenkov; KTH; []
    Nyckelord :ferrites; thin films; ferromagnetic resonance; microwaves; FMR spectrometer; magnetic anisotropy; magnetostatic waves;

    Sammanfattning : This thesis compiles results of research in two mutuallydependent parts: 1) development of ferromagnetic resonance(FMR) spectrometer to study microwave properties offerromagnetic materials, and 2) characterization of new irongarnets: pulsed laser deposited Y3Fe5O12and Bi3Fe5O12films and Ce:Y3Fe5O12single crystal.First part describes a novelBroadbandFMRSpectrometerdesigned to characterize thin ferromagneticfilms. LÄS MER

  3. 2. Rotational Resonance in the Nuclear Magnetic Resonance of solids

    Författare :Torgny Karlsson; S Vega; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physical Chemistry; fysikalisk kemi;

    Sammanfattning : This thesis presents new physical phenomena in the rotational resonance NMR of magic-angle spinning solids. The theory of a new class of nuclear spin echoes is developed. LÄS MER

  4. 3. Resonance Testing of Asphalt Concrete

    Författare :Anders Gudmarsson; Nils Rydén; Björn Birgisson; Mihai Marasteanu; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Resonance frequencies; Modal testing; Frequency response functions; Cyclic loading; Tension-compression tests; Complex modulus; Complex Poisson’s ratio;

    Sammanfattning : This thesis present novel non-destructive laboratory test methods to characterize asphalt concrete. The testing is based on frequency response measurements of specimens where resonance frequencies play a key role to derive material properties such as the complex modulus and complex Poisson’s ratio. LÄS MER

  5. 4. Modal Decomposition of Separated Nozzle Flow

    Författare :Ragnar Larusson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Arnoldi; axisymmetric convergent-divergent nozzle; Mode Decomposision; Flow Separation; Resonance.; Dynamic Mode Decomposision; Computational Fluid Dynamics;

    Sammanfattning : The applicability of two different eigenvalue algorithms coupled with an axisymmetric RANS solver to predict the eigenmodes of separated supersonic flow inside an axisymmetric convergent-divergent nozzle was investigated. These are the Arnoldi and the Dynamic Mode Decomposition (DMD) algorithms, respectively. LÄS MER

  7. 5. Radio Frequency Systems for NMR Imaging: Coil Development and Studies of Non-Thermal Biological Effects

    Författare :Lars Malmgren; Lunds universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; anechoic chamber; TEM transmission cells; FDTD; circularly polarized electromagnetic fields; reduced coupling; noise matching; matching networks; low noise amplifiers; upper thoracic spine; surface coils; Nuclear magnetic resonance; magnetic resonance imaging; non-thermal biological effects; blood-brain barrier; Electronics; Elektronik;

    Sammanfattning : This thesis concerns both design and optimization of NMR imaging systems and studies on non-thermal biological effects of electromagnetic fields. These two research fields are linked together by the fact that humans are subject to static and pulsed magnetic fields as well as to magnetic radio frequency fields (RF) during an NMR imaging investigation. LÄS MER