Ultrasonic characterization principles

McClements, D. J., 1997. Ultrasonic characterization of food and drinks Principles, methods and applications. Crit. Rev. Food Sci. 37 1—46. 

Applications The physical principle of measurement is similar to the scanning acoustic microscopy discussed in the Section 14.23, but applications and the method of data processing are essentially different. Sonic methods were used in the following applications to filled materials the effect of particle size and surface treatment on acoustic emission of filled epoxy, longitudinal velocity measurement of tungsten filled epoxy, and in-line ultrasonic measurement of fillers during extrusion. Numerous parameters related to fillers can be characterized by this non-destructive method. 

In this article, we introduce a recently developed ultrasonic spectroscopy method and review its application to polymeric studies. First, the principle of this ultrasonic spectroscopy is explained including the instruments and data analysis methods. Then, actual application of this measuring system is described for the characterization of solid polymers and the observation of phase transition phenomenon in liquid crystals and ferroelectric (VDF/TrFE) copolymer. Finally, the extension of this system to two-dimensional measuring and the application to non-destructive testing of CFRP (carbon fiber reinforced plastics) are discussed. 

Interaction between ultrasound and tissue can be characterized by a number of parameters like speed of propagation, attenuation, absorption coefficients etc. As ultrasound velocity is characteristic for a particular tissue the possibility is opened for ultrasound velocity tomography. The principles hereof and implications for medicine have been described by Greenleaf et al. (1975). In ultrasound velocity tomography transmitters and receivers are positioned around the object under study. Times of flight of ultrasonic pulses from transmitter to receiver are measured accurately. By rotating the transmitters and receivers in a plane around... 

The equilibrium is dynamic in the way that a continual exchange of solute molecules takes place between the micelles and the bulk water. It has been shown previously (1) that the exchange process involving the alcohols propan-l-ol to hexan-l-ol and CTAB micelles is characterized by a single relaxation time in the ultrasonic frequency range 0.7 - 105 MHz. The dynamics of this process was described in terms of the kinetic principles previously... 

The general principle of acoustic measurements for layer characterization is to follow the ultrasonic eedio reflected on the top of a layer and the one reflected on the bottom of the layer. One can write ... 

Monchalin J-P (1993) Progress towards the application of laser ultrasonics in industry. In Thompson DO, Chimenti DE (eds) Review of progress in QNDE 12. Plenum Press, New York, pp 495-506 Monchalin J-P (2007) Laser-ultrasonics principles and industrial applications. Chap 4. In Chen CH (ed) Ultrasonic and advanced methods for nondestructive testing and material characterization. World Scientific, Singapore, pp 79-115 Pilarski A, Rose JL, Balasubramian K (1990) The angular and frequency characteristics of reflectivity from a solid layer embedded between two solids with imperfect boundary conditions. J Acoust Soc Am 87 532-542... 

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