Sökning: "resonant absorbers"

Visar resultat 1 - 5 av 6 avhandlingar innehållade orden resonant absorbers.

  1. 1. Absorption Characteristics of Periodically Perforated Suspended Ceilings

    Författare :Dag Holmberg; Teknisk akustik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Building construction; Byggnadsteknik; measurement device.; flow resistance; suspended ceilings; periodically perforated facing; resonant absorbers; Room acoustics; building acoustics;

    Sammanfattning : The sound absorption characteristics of resonant absorbers, implemented as perforated suspended inner ceilings attached with thin porous layers, are investigated. Several existing theories model the principal absorption mechanisms, but the interaction with the outer sound field influences the absorption in ways that can be modelled with new approaches. LÄS MER

  3. 2. Optimization of resonant all-dielectric nanoparticles for optical manipulation and light management

    Författare :Nils Odebo Länk; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; FDTD; Nanophotonics; Metasurfaces; Optical Forces; All-dielectric; Perfect Absorption; Silicon;

    Sammanfattning : The resonant interaction between light and matter lies at the heart of nanophotonics research. In particular, nanoparticles that possess optical resonances in the visible spectral range have been avidly studied and employed for various technical and biological applications in the last two decades. LÄS MER

  4. 3. Innovative noise control in ducts

    Författare :Maaz Farooqui; Mats Åbom; Hans Bodén; Tamer Elnady; Jeong-Guon Ih; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Locally resonant materials; slow sound; acoustic impedance; metallic foam; low frequency noise; mufflers; lined ducts; grazing flow; flow duct; impedance eduction.; Vehicle and Maritime Engineering; Farkostteknik;

    Sammanfattning : The objective of this doctoral thesis is to study three different innovative noise control techniques in ducts namely: acoustic metamaterials, porous absorbers and microperforates. There has been a lot of research done on all these three topics in the context of duct acoustics. LÄS MER

  5. 4. Electromagnetic Waves in Media with Ferromagnetic Losses

    Författare :Jörgen Ramprecht; Martin Norgren; Constantin Simovski; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electrophysics; Elektrofysik;

    Sammanfattning : The operation of a wide variety of applications in today's modern society are heavily dependent on the magnetic properties of ferromagnetic materials and their interaction with electromagnetic fields. The understanding of these interactions and the associated loss mechanisms is therefore crucial for the improvement and future development of such applications. LÄS MER

  7. 5. 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