Common dispersion methods such as ultrasonic sonication, planetary centrifugal mixing and magnetic dispersion have been used extensively to achieve moderate exfoliation of nanoparticles in polymer matrix. In this study, the effect of adding three roll milling to these three dispersion methods for nanoclay dispersion into epoxy matrix was investigated. A combination of each of these mixing metho...

This paper describes a simulation of signal pathway in an ultrasonic A-scan. It includes transient diffraction acoustic field, transducer response, absorption and dispersion in viscoelastic medium with arbitrary distribution function. The approach selected here aims at developing digital computer simulation of the physical process that underlies these effects. The soft tissue is considered as a...

Ultrasound technology was used to analyse the freezing behaviour of orange juice. The ultrasonic properties of orange juice, specifically velocity and attenuation coefficient, were characterised as the temperature was decreased from 20 to −50 ◦C. The results were compared with NMR free induction decay data and correlated with the amount of unfrozen water present in the frozen sample. The veloci...

This brief note reports on a study that applies the reassigned spectrogram (the reassigned energy density spectrum of the short-time Fourier transform [STFT]) to develop the dispersion curves for multimode Lamb waves propagating in an aluminum plate. The proposed procedure first uses the spectrogram to operate on a single, laser-generated and detected waveform to develop the dispersion relation...