Results 211 to 220 of about 35,365 (254)
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Broadband controllable acoustic focusing and asymmetric focusing by acoustic metamaterials
Smart Materials and Structures, 2021Abstract The applications of acoustic focusing and acoustic asymmetric focusing (AAF) are severely constrained by the narrow frequency bandwidth. In this paper, we report broad bandwidth acoustic focusing lens and asymmetric acoustic focusing lens consisting of monolayer and dual-layer metamaterials, respectively.
Guangxin Liao +5 more
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Nonlocal Metasurface for Acoustic Focusing
Physical Review Applied, 2021Under the passive and lossless requirement, acoustic metasurfaces are mostly designed based on the general Snell's law (GSL), under which the power flow-conservation condition is locally satisfied along the whole surface. Recent investigations on metagrating show, however, that such kinds of structures have an intrinsic problem in their efficiency.
Huifang Xie, Zhilin Hou
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Focusing of microwave acoustic beams
Ultrasonics, 1967A description is given of an experimental study, using Bragg scattering, of the properties of cylindrically-focused longitudinal-wave acoustic beams in fused quartz in the frequency range 200–425 Mc/sec. The results are analyzed and shown to be in good agreement with Fresnel diffraction theory indicating, as expected, that elastic waves at ultrasonic ...
M. G. Cohen, E. I. Gordon
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Acoustic particle migration and focusing in a tilted acoustic field
Physics of Fluids, 2021Surface acoustic wave-based particle/bioparticle manipulation has emerged as a promising tool for disease diagnosis. The effects of the titled angle of the acoustic field θ and the microchannel aspect ratios β on the particle migration mode, the force of particle, and the three-dimensional focusing behavior are studied by using simulation and high ...
Sen Xue +4 more
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Focusing PVDF transducers for acoustic microscopy
Research in Nondestructive Evaluation, 1995A focusing transducer based on a 9-µm thick PVDF foil was fabricated and tested for performance. The transducer operates in the frequency range of 20–160 MHz. For operation at 78 MHz in water, a lateral resolution of 27.5 µm and a vertical resolution of 35 µm have been observed.
S. Smolorz, W. Grill
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Sound focusing by a broadband acoustic Luneburg lens
The Journal of the Acoustical Society of America, 2022The high-performance and aberration-free broadband acoustic lens holds promise for extensive applications, yet remains challenged. In this work, a scheme is proposed, and the experimental demonstration of a planar acoustic Luneburg lens capable of focusing broadband sound ranging from 1 to 3 kHz (relative bandwidth approaching to 100%) in an aberration-
Baoguo Yuan +4 more
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A circularly focused and scanned acoustic scanner
IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control, 1999This paper describes a new type of electronically scanned and focused acoustic imaging device called the cylindrical grating acoustic scanner. With this device, a new transducer called the circular-edge-bonded transducer (CEBT) is devised that is bonded on one end of a cylindrical substrate and can generate a surface acoustic wave propagating along the
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Ear-focused acoustic reflector
The Journal of the Acoustical Society of America, 1991An acoustic device for mechanically reflecting sound waves into the ear in an undistorted and directionally selective manner has a pair of movable acoustic reflectors constructed, configured and mounted to preserve accurately phase, frequency and image information in the sound waves of interest to the front of the user, secured to a headband or helmet ...
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Acoustic focusing flow cytometry
The Journal of the Acoustical Society of America, 2012Acoustic cytometry is a new technology that replaces or partly replaces hydrodynamic focusing of cells or particles in flow cytometry with forces derived from acoustic radiation pressure. The ability to focus cells into a tight line without relying on hydrodynamic forces allows many possibilities outside the scope of conventional flow cytometry. Dilute
Gregory Kaduchak +2 more
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Focusing in a quadrupole acoustic channel
Journal of Aerosol Science, 2009Abstract We investigate analytically and numerically focusing of aerosol micron-and-submicron size particles in the incompressible laminar flow in a three-dimensional quadrupole acoustic channel of hyperbolic cross-section. The fluid–particle interaction of micron-size non-diffusive particles is described by a linear drag force. Considering motion of
P. Vainshtein, M. Shapiro
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