Sökning: "harmonic spectrum"

Visar resultat 21 - 25 av 53 avhandlingar innehållade orden harmonic spectrum.

  1. 21. Diagnostics of stator insulatin by dielectric response and variable frequency partial discharge measurements : a study of varied low frequencies in stator insulation, with particular attention to end-winding stress-grading

    Författare :Nathaniel Taylor; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electrical engineering; Elektroteknik;

    Sammanfattning : Stator insulation is a critical to the reliability of electrical generators and motors. It is common industrial practice to use electrical measurement of partial discharges (PD) and some form of current-voltage measurement as part of the condition assessment of stator insulation at maintenance times. LÄS MER

  3. 22. Neutron emission spectroscopy of fusion plasmas with a NE213 liquid scintillator at JET

    Författare :Federico Binda; Göran Ericsson; Chernikova Dina; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NE213; neutron spectroscopy; liquid scintillator; nuclear; fusion; plasma;

    Sammanfattning : Neutron diagnostics will play a fundamental role in future fusion plasma machines,where the harsh environment will make the use of many other type of diagnos-tics practically impossible. Complex techniques to measure the neutron spectrumemitted from tokamk plasmas have been developed over the years, producing stateof the art neutron spectrometers. LÄS MER

  4. 23. Nonlinear Interaction Between Ultrasonic Waves and Cracks and Interfaces

    Författare :Milan Poznic; Leif Kari; Bruce Drinkwater; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; ultrasonic waves; crack; modulation; rough interface; partially closed; surface-breaking; fluid-filled; Acoustics; Akustik;

    Sammanfattning : The subject of this thesis is the development of new ultrasound inspection techniques for detection of cracks that are smaller than the wavelength of the inspecting wave and the characterization of cracks in fluid-filled pipes as either surface-breaking or subsurface. The spectrum of the scattered field of a partially closed crack comprises harmonic components not expected to be found in the case of linear scatterers such as pores or inclusions. LÄS MER

  5. 24. Spectra and Dynamics of Excitations in Long-Range Correlated Structures

    Författare :Lars Kroon; Rolf Riklund; Magnus Johansson; Jeroen Lamb; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; quasicrystals; deterministic aperiodic superlattices; Markov chains; electronic structure and diffusion; elastic vibrations; Fraunhofer diffraction; discrete solitons; phase transitions; Condensed matter physics; Kondenserade materiens fysik;

    Sammanfattning : Vad karaktäriserar en kristall? Svaret på denna till synes enkla fråga blir kanske att det är en anordning av atomer uppradade i periodiska mönster. Så ordnade strukturer kan studeras genom att det uppträder så kallade Braggtoppar i röntgendiffraktionsmönstret. LÄS MER

  7. 25. Delocalization in nonperiodic systems

    Författare :Lars Kroon; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : The localization properties of non-interacting linear excitations in one-dimensional aperiodically ordered structures are investigated from a theoretical point of view. The models used have various relevance for real systems, like quasicrystals, photonic crystals, and deterministic aperiodic superlattices. LÄS MER