Results 21 to 30 of about 40,603 (292)
Evaluating the applicability of a screen diffraction approximation to local volcano infrasound
Volcanica, 2021 Atmospheric acoustic waves from volcanoes at infrasonic frequencies (0.01–20 Hz) can be used to estimate source parameters for hazard modeling, but signals are often distorted by wavefield interactions with topography, even at local recording distances (
Sean Maher +4 more
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Numerical study of acoustic focusing using a bianisotropic acoustic lens [PDF]
The Journal of the Acoustical Society of America, 2020 Materials with sub-wavelength asymmetry and long-range order have recently been shown to demonstrate acoustical properties analogous to electromagnetic bianisotropy. One characteristic of bianisotropic acoustic media is the existence of direction-dependent acoustic impedance. Therefore, the magnitude and phase of the acoustic fields transmitted through
A J, Lawrence +3 more
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On the Design of Soret Zone Plates Based on Binary Sequences Using Directional Transducers
Sensors, 2021 In this work, we analyze the effect of the distribution of transparent Fresnel regions over the focusing profile of Soret Zone Plates (SZP) based on binary sequences. It is shown that this effect becomes very significant in those fields where directional
Pilar Candelas +2 more
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Acoustic wavefront manipulation via transmission-type labyrinth structure
Frontiers in Physics, 2022 In this work, a transmission-type labyrinth structure (LS) is proposed to construct subwavelength acoustic functional metasurfaces, through which various desirable acoustic wavefront manipulation can be achieved in a broadband from 2,700 Hz to 3,900 Hz ...
Rui Wang, Fengbao Yang
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Computational method for acoustic wave focusing [PDF]
International Journal of Computing Science and Mathematics, 2007 13 pages, 4 ...
Alexander G. Ramm, Semion Gutman
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Acoustical hooks: A new subwavelength self-bending beam
Results in Physics, 2020 In this work, we report the first experimental observation of a new type of near-field curved acoustic beam confirmed by simulations. This new curved acoustical beam is generated by asymmetric distribution of the vortices in a polymer Janus particle ...
Constanza Rubio +4 more
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The Potential of Focusing Acoustic Retroreflectors for Architectural Surface Treatment
Applied Sciences, 2023 How much sound can a building surface reflect to a source, the location of which is not exactly known? This paper considers this question particularly for a planar surface acting as an array of retroreflectors, or of focusing retroreflectors.
Densil Cabrera +3 more
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Focusing Ultrasound with an Acoustic Metamaterial Network [PDF]
Physical Review Letters, 2009 We present the first experimental demonstration of focusing ultrasound waves through a flat acoustic metamaterial lens composed of a planar network of subwavelength Helmholtz resonators. We observed a tight focus of half-wavelength in width at 60.5 kHz by imaging a point source.
Shu, Zhang, Leilei, Yin, Nicholas, Fang
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Design of Acoustic Bifocal Lenses Using a Fourier-Based Algorithm
Sensors, 2021 In this work, we develop a new design method based on fast Fourier transform (FFT) for implementing zone plates (ZPs) with bifocal focusing profiles. We show that the FFT of the governing binary sequence provides a discrete sequence of the same length ...
José Miguel Fuster +2 more
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Helmholtz-Structured Two-Dimensional Super-Diffraction Meta-Lens
Frontiers in Physics, 2022 Focusing beyond the acoustic diffraction limit has always been expected, especially in acoustic imaging and ultrasonic therapy. Manipulating the acoustic waves beyond the diffraction limit offers an alternative application potential in high-resolution ...
He-He Li +8 more
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