Fundamentals and Applications of Ultrasonic Waves

Abstract

These reviews of books and other forms of information express the opinions of the individual reviewers and are not necessarily endorsed by the Editorial Board of this Journal.The book Seismic Ray Theory by V. Cerveny is concerned with the theory of high-frequency body wave propagation in an inhomogeneous, anisotropic elastic solid. The book is the most complete description of this topic that is currently available. The author is exceptionally well qualified to write such a book as he has made many fundamental contributions to the material covered.The book is comprised of six chapters. The first provides a brief overview of the book. In Chap. 2 the elastodyanmic equations of motion in an inhomogeneous, anisotropic 3-d elastic medium are introduced. Elementary plane wave solutions and Green's function solutions are discussed, and the equations governing high-frequency asymptotic wave motion are systematically developed. Anisotropy, first introduced here, remains a central theme throughout the book. Chapter 3 is concerned with the solution to the coupled ray and travel time equations in 3-d environments. Chapter 4 develops dynamic ray tracing wherein the evolution of ray variational quantities following ray trajectories is described. The propagator matrix is introduced. Chapter 5 is concerned with the calculation of ray amplitudes. Included are discussion of Gaussian beam summation methods and the Maslov-Chapman integral. Chapter 6 is concerned with the time domain-the construction of the transient response, a synthetic seismogram, to transient forcing.All of the material presented is developed from basic concepts, so the reader need not have any a priori knowledge of ray methods or waves in elastic solids. A moderately strong mathematical background ͑familiarity with complex variables, integral transforms, and vector and tensor calculus͒ and some knowledge of basic continuum mechanics is assumed, however. While some mathematical skill is required, Cerveny does a good job of keeping the focus on the physics, not allowing the mathematics to become a distraction. The focus of the book is clearly and consistently on the theory of ray methods in seismic wave propagation. The theory behind some numerical methods is discussed, but numerical methods are themselves not a focus. Practical issues relating to seismic data interpretation are not considered. The choice of material covered is fairly traditional with an emphasis on results that are needed to solve seismic body wave problems. Some less traditional topics such as ray chaos, the catastrophe classification of caustics, and the use of space-time rays to model surface ͑Rayleigh and Love͒ wave propagation problems are discussed, but only very briefly.Two clear strengths of the book are its treatment of elastic media, including anisotropy and dissipative effects, and its treatment of the time domain, i.e., the construction of synthetic seismograms. The strong focus on transient wavefields is not surprising, as in seismic applications fixed frequency wavefields are of inte...

Detection of Internal Defects in Potato Based on Ultrasound Attenuation

“…This method is based on the idea that ultrasonic parameters are sensitive to the tissue changes of the medium through which they are transmitted (Cheeke 2002). Accordingly, 4 pairs of ultrasonic ceramic transducers, receivers and transmitters, were used to generate ultrasonic pulses on one side of potato tubers to be received on the other.…”

“…To avoid this, a nondestructive ultrasonic method has been tested on several crops mainly to determine ripeness and to determine defects and quality status (Cheeke 2002;Dolatowski et al 2007;Mizrach 2008;Cao et al 2010). In one study, ultrasonic waves were used for nondestructive detection of hollow heart in potatoes.…”

The Nature of Exhibits About Acoustics in Science and Technology Centres

“…Therefore, aspects such as the mapping of the structure of the marine sediments (Lynch 2000), fish and plankton density distribution and type, measures of ships speed, or high-accuracy in navigation are omitted (Spindel 1997). The coverage of ultrasonic engineering does not represent current applications which include the use of ultrasonic frequencies: to inspect flaw materials (Wade 2000), to activate enzymes in biotechnology industry (Cheeke 2000), as a contrast agent in medical diagnosis, or as an agent in drug delivery (Fowlkes 1997). Few if any narratives were explicitly mentioned in the text accompanying the exhibits.…”

Ultrasound tomography

“…It is important to understand these interactions as they are what make an ultrasound system capable of delivering information on a sample or process. For further information on acoustic and ultrasound theory in fluid systems the reader should refer to Povey (1997), Dukhin and Goetz (2002), Challis, Povey, Mather, and Holmes (2005) and Cheeke (2002).…”