Un dispositivo elettronico ultrasottile, dello spessore di tre micron, può essere applicato a tutti i tipi di superficie, irregolari, curve, delicate e flessibili, come foglie, lenti ottiche o bucce...
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Fundamental acoustic theory is reviewed with respect to wave amplitude: infinitesimal or finite. The evolution of finite-amplitude waves is developed from the equation of state for fluids. Both Fubini and Fay solutions to the wave equation, respectively pre- and post-shock, are illustrated numerically. The physics and mathematics of the parametric acoustic array are described together with Westervelt’s solution, thence parametric sonar, consisting of a parametric transmitter and conventional linear receiver. Several underwater applications are described, with numerical evaluation of the nearfield and other properties for a particular sub-bottom profiling parametric sonar. Its use in measurement of Atlantic herring in the mid-water column is described. Calibration is also illustrated.
Bio
Kenneth Foote is a Senior Scientist at the Woods Hole Oceanographic Institution and an IEEE Fellow. He received the BS degree in electrical engineering from The George Washington University and a PhD in physics from Brown University. He works in the general area of underwater sound scattering, with applications to marine resource quantification, bottom object detection, and sonar performance evaluation, among others. In developing and transitioning acoustic methods and instruments to operations at sea, he has worked from 77°N to 55°S.