Mechanism of Acoustic Absorption in Tissue
نویسنده
چکیده
A viscous mechanism for the absorption of ultrasonic energy in tissue is considered. It is shown that the viscous forces acting between a suitably chosen distribution of suspended particles or structure lements and a suspending liquid can account for the experimentally observed linear elations between acoustic absorption coefficient and ultrasonic frequency. The frequency band over which linearity obtains i determined bythe limits of the distribution of values for the parameters which describe the structure elements. Below the linear range the relation becomes quadratic, inagreement with experiment, and at "high" frequencies a limiting value is approached asymptotically.
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