Results 281 to 290 of about 1,265,505 (345)
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Three-dimensional acoustic impedance mapping of cultured biological cells.
Ultrasonics, 2019The acoustic microscope is a powerful tool for the observation of biological matters. Non-invasive in-situ observation can be performed without any staining process.
N. Hozumi, S. Yoshida, Kazuto Kobayashi
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Surface acoustic impedance and causality
The Journal of the Acoustical Society of America, 2001Several models that are commonly used to calculate the surface acoustic impedance of porous materials are examined in light of the causality requirement in its nonlocal and its approximate local forms. Strict (nonlocal) causality requires that the imaginary part of the surface acoustic impedance be the Hilbert transform of the real part.
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Active Control of Wall Acoustic Impedance
AIAA Journal, 1999A novel kind of acoustic liner with controllable impedance is proposed. A set of active control systems has been designed for this kind of liner to control the sound absorption coefficient or the impedance of the liner. The control is achieved by adjusting the liner cavity depth and bias flow rate through the perforated plate of the liner.
Hongwu Zhao, Xiaofeng Sun
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Acoustic Impedance Transformation-Reply
Archives of Otolaryngology - Head and Neck Surgery, 1987In Reply .—Dr Kimberley is incorrect when he states that "a mechanical/acoustical system such as the external ear is quite incapable of impedance transformation, at any frequency." One way to model the acoustic function of the external ear is as a small horn whose mouth contacts the low specific impedance air of the external environment (41.5 acoustic ...
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Acoustic impedance matching device
The Journal of the Acoustical Society of America, 1982A impedance matching window for an ultrasound transducer comprises a periodic array of stepped structures. Each stepped structure comprises a plurality of parallel matching strips disposed side-by-side on an active surface of a piezoelectric ceramic.
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Acoustic impedance inducing device
The Journal of the Acoustical Society of America, 1989An acoustical impedance inducing device is created for axial insertion into the longitudinal air column of a wind musical instrument. The device includes a first annular band of first predetermined thickness and a second annular band of approximately twice the thickness of the first band.
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Acoustic Impedance Inversion of VSP data
Proceedings, 2013During the drilling stage, VSP plays an important role in predicting the depth of target strata and the lithologic characteristics of the deep strata ahead of the drill bit. Therefore, using VSP data to predict ahead of the drill bit has become a popular topic.
Jing Wang, Yanpeng Li, Jinling Du
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Acoustic impedance of the maternal abdomen
The Journal of the Acoustical Society of America, 1993Contact sensors to monitor fetal heart, breathing, and movement sounds with increased sensitivity and bandwidth are under development. To understand the inherent acoustical properties of the maternal abdomen and its interaction with these sensors, the driving-point impedance Z(jω) was measured in nine women during their last trimester of pregnancy.
G R, Wodicka +3 more
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