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...

The propagation of low intensity ultrasound in a curing resin, acting as a high frequency oscillatory excitation, has been recently proposed as an ultrasonic dynamic mechanical analysis (UDMA) for cure monitoring. The technique measures sound velocity and attenuation, which are very sensitive to changes in the viscoelastic characteristics of the curing resin, since the velocity is related to th...

An experimental study was carried out to investigate the effect of local ultrasonic forcing on a turbulent boundary layer. The ultrasonic forcing system was constructed by adhering six ultrasonic transducers to a flat plate over which water was flowed. In this system, the ultrasonic waves projected into the water by the transducers caused cavitation, giving rise to an enormous number of tiny ai...

Ultrasonic gas flowmeters typically use narrowband piezoelectric transducer arrangements for interrogating the flow of gas in a pipe. In this work, the suitability of broadband electrostatic transducers operating at frequencies of up to 1 MHz for ultrasonic measurement of gas flow has been investigated. The transit time method of ultrasonic gas flow measurement was adopted and experiments were ...

Ultrasonic colour Doppler is an imaging technique that combines anatomical information derived using ultrasonic pulse-echo techniques with velocity information derived using ultrasonic Doppler techniques to generate colour-coded maps of tissue velocity superimposed on grey-scale images of tissue anatomy. The most common use of the technique is to image the movement of blood through the heart, a...

In this paper, we propose a new method for automatically tracking the motion of local region in left ventricular myocardium by means of ultrasonic pulsed Doppler signal. This method consists of a velocity detection procedure based on correlation weighted mean instantaneous velocity and a motion tracking procedure employing a myocardial elastic model. Most of ultrasonic pulsed Doppler signals ob...

Experimental techniques employed in the present work for the measurement of density, ultrasonic velocity, viscosity and working principle of ultrasonic interferometer have been discussed in this paper. In addition to that, the present paper also includes a brief discussion on experimental setup, different parts, procedure of ultrasonic interferometer, and various thermodynamic parameters which ...

Methods of measuring ultrasonic wave velocity in an elastic sample require data on the thickness of the sample and/or the distances between the transducers and the sample. The uncertainty of the ultrasonic wave velocity measurements generally depends on that of the data available. Conversely, to determine the thickness of a material, it is necessary to have a priori information about the wave v...

A study is presented of a miniature ultrasonic surgical drill designed for bone biopsy, based on an ultrasonic/sonic drill which converts high frequency to low frequency vibrations through a freely vibrating mass between an ultrasonic transducer-horn and a drill bit. For conventional surgical drilling using a rotary drill or an ultrasonic drill, considerable power is required to penetrate into ...

This work considers the characterization of linear PVC acoustic properties using a linear ultrasonic measurement technique and the non-collinear ultrasonic wave mixing technique for measurement of the physical ageing state in PVC. The immersion pulse-echo measurements were used to evaluate phase velocity dispersion and attenuation of longitudinal waves in PVC test specimens. The suggested nonco...