Results 221 to 230 of about 35,365 (254)

Focusing of acoustic energy at the conical point in zinc

Physical Review Letters, 1993
This paper reports observations of the intense focusing of acoustic energy that occurs along the symmetry axis in a zinc single crystal. The focusing is associated with a conical point in the wave surface and thereby the phenomenon of external conical refraction.
, Kim, , Sachse, , Every
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Multiple field acoustic focuser

The Journal of the Acoustical Society of America, 1984
The invention provides a highly focussed ultrasonic wave throughout a large depth of field without any mechanical motion. One embodiment of the invention providing two focussed fields includes a front to back arrangement of a converging lens, a transducer without any backing material to dissipate ultrasound, a converging lens, and a transducer.
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Time Reversal Acoustic Focusing With A Catheter Balloon

Ultrasound in Medicine & Biology, 2010
The ability to deliver configurable myocardial lesions was noted as a critical factor to the success of atrial fibrillation (AF) treatment. This article considers the implementation of time reversal acoustics (TRA) principles for ultrasound focusing using an AF cardiac catheter developed for pulmonary vein isolation. Experiments conducted with a single
Yegor D, Sinelnikov, Alexander M, Sutin, Andrey Y, Vedernikov, Armen P, Sarvazyan   +3 more
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Acoustic Focusing with Spherical Structures

The Journal of the Acoustical Society of America, 1963
A variety of structures in the form of spheres can provide sharp focusing and directivity gains comparable to those from a circular piston with the same diameter. With an isotropic refractive sphere, spherical aberration does not impair focusing except for angular resolutions of the order of a few degrees and less.
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Alternate focusing fluids for passive acoustic targets

The Journal of the Acoustical Society of America, 1990
Fluid-filled, focusing spheres are often used as passive acoustic targets because of their relatively high target strength and aspect-independent characteristics. A fluid mixture consisting of equal parts by weight of trichlorotrifluoroethane and carbon tetrachloride provides a near-optimum index of refraction.
H, Boehme, J E, Stockton
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Photoacoustic cell using elliptical acoustic focusing

Applied Optics, 1982
A photoacoustic cell has been developed in the form of an elliptical cylinder in which essentially all the acoustic energy generated by a laser beam passing down one axis is focused onto a cylindrical acoustic transducer located along the other axis.
J M, Heritier, J E, Fouquet, A E, Siegman   +2 more
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Nonlinear acoustic propagation and focusing

Radiophysics and Quantum Electronics, 1993
Two model equations of nonlinear acoustics are considered. The implications of a point transformation between forms of the generalised Burgers equation (GBE) is discussed. New exact and asymptotic solutions are obtained. The dissipative Zabolotskaya-Khokhlov (DZK) equation describing acoustic wave propagation with allowance for transverse amplitude ...
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Meteorological Focusing of Acoustic Energy

Sound: Its Uses and Control, 1963
Meteorological focusing of acoustic energy by calculating acoustic ray paths, to be used as a method of noise ...
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Self-focused acoustic ejectors for viscous liquids

Review of Scientific Instruments, 2010
Self-focused acoustic ejectors using the Fresnel zone plate (FZP) have been developed for ejecting viscous liquids, without nozzle, in the drop-on-demand mode. The FZP is composed of a lead zirconate titanate piezoelectric plate patterned with a series of annular electrodes, with the unelectroded region of the plate removed.
Hon, SF, Kwok, KW, Li, HL, Ng, HY
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Bidirectional asymmetric acoustic focusing with two flat acoustic metasurfaces

Chinese Physics B, 2018
We design an asymmetric transmission system (ATS) with two flat acoustic metasurfaces (AMs) to yield bidirectional asymmetric acoustic focusing (BAAF). The acoustic waves could be focused on both sides of the ATS with different focal lengths and intensities. To achieve high intensity energy concentration, the accelerating acoustic beams are selected to
Di-Chao Chen, Xing-Feng Zhu, Qi Wei, Da-Jian Wu   +3 more
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