Sökning: "Perforates"

Hittade 3 avhandlingar innehållade ordet Perforates.

  1. 1. Modelling and Characterization of Perforates in Lined Ducts and Mufflers

    Författare :Tamer Elnady; KTH; []
    Nyckelord :Perforates; Liners; Acoustic impedance; Hot stream liners; Hard splices; Mufflers; Lined ducts; Collocation; Flow duct.;

    Sammanfattning : Increased national and international travel over the lastdecades has caused an increase in the global number ofpassengers using different means of transportation. Greateffort is being directed to improving the noisy environment inthe residential community. LÄS MER

  3. 2. Varför får jag icke följa med dit fram? : Medborgarskapet och den offentliga debatten om dövstumma och blinda 1860–1914

    Författare :Staffan Bengtsson; Staffan Förhammar; Marie C. Nelsson; Svenbjörn Kilander; Linköpings universitet; []
    Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; Citizenship; disability; social policy; social categorisation; social recognition; gender; Disability research; Handikappsforskning;

    Sammanfattning : Different kinds of cultural studies can be used in order to learn more about disability, social policies, attitudes and citizenship. The purpose of this study is to outline some aspects of disability and Swedish society during the 19th century. The ambition is to analyse the issue of the integration of the deaf-mutes and the blind. 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