An ultrasonic scattering technique for microparticle characterization

An ultrasonic Bragg scattering technique for the quantitative characterization of marbling in beef

Microparticle trapping in an ultrasonic Bessel beam.

This paper describes an acoustic trap consisting of a multi-foci Fresnel lens on 127 μm thick lead zirconate titanate sheet. The multi-foci Fresnel lens was designed to have similar working mechanism to an Axicon lens and generates an acoustic Bessel beam, and has negative axial radiation force capable of trapping one or more microparticle(s). The fabricated acoustic tweezers trapped lipid part...

A Technique for Determining Flaw Characteristics from Ultrasonic Scattering Amplitudes

We report an approximate technique for determining the characteristics of flaws in elastic media from a knowledge of their ultrasonic scattering amplitudes. The technique is rigorously valid in the weak scattering limit. Good results have been obtained for strongly scattering flaws. In particular, we tested the technique for a 2-1 oblate spheroidal void in Ti, and for various strongly scatterin...

An Ultrasonic Technique for Sizing Surface Cracks

Rayleigh surface waves are proposed as a non-destructive method to find the depth of surface cracks. The paper describes how dynamic photoelasticity was used to develop an understanding of the subsurface interactions between R-waves and a narrow slot. A frequency analysis of the transmitted wave confirmed that the slot acts as a low pass filter for the high frequency Fourier components of the i...

Microparticle characterization using digital holography

Digital holography is an effective 3D imaging technique, with the potential to be used for particle size measurements. A digital hologram can provide reconstructions of volume samples focused at different depths, overcoming the focusing problems encountered by other imaging based techniques. Several particle analysis methods discussed in the literature consider spherical particles only. With th...