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(Referência obtida automaticamente do Web of Science, por meio da informação sobre o financiamento pela FAPESP e o número do processo correspondente, incluída na publicação pelos autores.)

Producing acoustic `Frozen Waves': Simulated experiments with diffraction/attenuation resistant beams in lossy media

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Autor(es):
Prego-Borges, Jose L. [1] ; Zamboni-Rached, Michel [1] ; Recami, Erasmo [2, 1, 3] ; Costa, Eduardo Tavares [1]
Número total de Autores: 4
Afiliação do(s) autor(es):
[1] Univ Estadual Campinas, Fac Elect & Comp Engn, Campinas, SP - Brazil
[2] Ist Nazl Fis Nucl, Sez Milano, I-20133 Milan - Italy
[3] Bergamo State Univ, Fac Engn, Bergamo - Italy
Número total de Afiliações: 3
Tipo de documento: Artigo Científico
Fonte: ULTRASONICS; v. 54, n. 6, p. 1620-1630, AUG 2014.
Citações Web of Science: 4
Resumo

The so-called Localized Waves (LW), and the ``Frozen Waves{''} (FW), have raised significant attention in the areas of Optics and Ultrasound, because of their surprising energy localization properties. The LWs resist the effects of diffraction for large distances, and possess an interesting self-reconstruction -self-healing- property (after obstacles with size smaller than the antenna's); while the FWs, a sub-class of LWs, offer the possibility of arbitrarily modeling the longitudinal field intensity pattern inside a prefixed interval, for instance 0 <= z <= L, of the wave propagation axis. More specifically, the FWs are localized fields ``at rest{''}, that is, with a static envelope (within which only the carrier wave propagates), and can be endowed moreover with a high transverse localization. In this paper we investigate, by simulated experiments, various cases of generation of ultrasonic FW fields, with the frequency of f(0) = 1 MHz in a water-like medium, taking account of the effects of attenuation. We present results of FWs for distances up to L = 80 mm, in attenuating media with absorption coefficient a in the range 70 <= alpha <= 170 dB/m. Such simulated FW fields are constructed by using a procedure developed by us, via appropriate finite superpositions of monochromatic ultrasonic Bessel beams. We pay due attention to the selection of the FW parameters, constrained by the rather tight restrictions imposed by experimental Acoustics, as well as to some practical implications of the transducer design. The energy localization properties of the Frozen Waves can find application even in many medical apparatus, such as bistouries or acoustic tweezers, as well as for treatment of diseased tissues (in particular, for the destruction of tumor cells, without affecting the surrounding tissues; also for kidney stone shuttering, etc.). (C) 2014 Elsevier B.V. All rights reserved. (AU)

Processo FAPESP: 13/12025-8 - Soluções não difrativas das equações de onda: contribuições a teoria, geração experimental, e aplicações
Beneficiário:Michel Zamboni Rached
Linha de fomento: Auxílio à Pesquisa - Pesquisador Visitante - Internacional
Processo FAPESP: 11/51200-4 - Ondas Não Difrativas: teoria, geração experimental e aplicações
Beneficiário:Michel Zamboni Rached
Linha de fomento: Auxílio à Pesquisa - Regular