We proposed an approach to construct a 2D Fresnel lenses by acoustic network. This lens iscomposed of an array of Helmholtz resonators. The resonance at individual resonators results ineffective focusing even the plate has subwavelength thickness. The FEM simulation resultspresented the ultrasonic wave propagation through the lenses together with the resultingdiffraction pat...

The evolution of the cavitation noise (CN) spectra in field a focusing emitter with an increase intensity ultrasound (US) was studied. Spectra without subharmonics f 0 /2 were recorded for first time, where is frequency generating cavitation,. Such spectrum observed partially degassed water at high duty cycle ultrasonic pulses. threshold appearance sonoluminescence (SL) coincides CR spectrum. I...

We demonstrate the possibility of selectively imaging the features of a barely visible impact damage in a laminated composite plate by using an air-coupled time reversal mirror. The mirror consists of a number of piezoelectric transducers affixed to wedges of power law profiles, which act as unconventional matching layers. The transducers are enclosed in a hollow reverberant cavity with an open...

ompetent performance of an ultrasound examination of any type is reliant on an understanding of the basic physical principles that govern the production of ultrasound waves and their interaction with biological tissues of differing densities and consistencies. It is also necessary to understand the basic concepts of how the ultrasound systems work and the concepts underlying their manipulation ...

Abstract The implementation of automated testing systems based on six degrees freedom (DOF) robotic manipulators is the actual trend in ultrasonic equipment development. Such are able to provide fast evaluation with respect surface object. In this work, post-processing algorithm Synthetic Aperture Focusing Technique (SAFT) suggested. allows presenting results form high-resolution imagery intern...

In order to improve the traditional methods of procyanidins extracting, ultrasonic-assisted filtration was used in the process of extracting proan-thocyanidin which was from membrane concentration of grape seed. Through the mechanism analysis of ultrasonic-assisted ultrafiltration, ultrasonic is able to alleviate the phenomenon of concentration polari-zation, so the efficiency of extracting pro...

In ultrasonic array imaging, 3D ultrasonic wavefields are normally recorded by an ultrasonic piezo array transducer. Its performance is limited by the configuration and size of the array transducer. In this paper, a method based on digital holographic interferometry is proposed to record the 3D ultrasonic wavefields instead of the array transducer, and the measurement system consisting of a pul...

Ultrasonic motors have been expected as a leader of new actuators since 1980th when they were invented. Author has been conducted research on analysis of characteristics of ultrasonic motors, development of novel ultrasonic motors including multi-degree-of-freedom (DOF) ultrasonic motors, and application of ultrasonic motors for robotic field. In this paper, several results are described.