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Underwater acoustics

Fig. 6.20 (a) Piezoceramic parts for a range of applications including accelerometers, underwater acoustics, pressure and liquid level sensors, medical diagnostics and therapeutics and NDT the ultrasound focusing bowls are for medical imaging and for producing high-intensity focused ultrasound. [Pg.381]

Acoustic measurements can also be used as a structural probe, since the acoustic properties, especially sound absorption, are related to many structural factors, such as transition temperatures, morphology, cross-link density, etc. Finally, they can be used as a source of engineering data, especially in the building and construction field for the absorption of unwanted sound, the construction of acoustically transparent windows, underwater acoustics, etc. [Pg.505]

Underwater acoustics is routinely used in laboratory-scale test facilities for flaw detection, transducer calibration, material property evaluations, and acoustic visualization. In a typical underwater acoustic study, an object of interest is submerged in a water filled tank and acoustically illuminated (insonified). The acoustic signals scattered by the object are then measured and analyzed. If the tank used is not sufficiently large, these measured acoustic signals will include spurious echo components due to extraneous wall reflections. Since the effect of these contaminating echoes usually cannot be removed from the resulting data set by post analysis, they must be prevented from occurring at their source. One cost... [Pg.208]

Many problems in ultrasonic visualization, nondestructive evaluation, materials design, geophysics, medical physics and underwater acoustics involve wave propagation in inhomogeneous media containing bubbles and particulate matter. A knowledge of the effect of voids or inclusions on the attenuation and velocity of sound waves is necessary in order to properly model the often complex, multilayered systems. [Pg.229]

Bobber, R. J., Underwater Acoustic Measurements Peninsula Publishing Los Altos, 1988, p. 306. [Pg.259]

Eynck, J. J. Characterisitics of Wave Guides Used To Evaluate Materials Intended for Underwater Acoustic Applications, Rubber Laboratory, San Franciso Bay Naval Shipyard Report 165-50,1967. [Pg.259]

Bobber, R.J., in "Underwater Acoustics and Signal Processing" Bjorno, L., Ed. Mathematical and Physical Sciences, NATO Advanced Study Institutes Series, 66, Series C., D Reidel Publ. Co.j Dordrecht, Holland, 1981 p 243. [Pg.408]

Polymers for Underwater Acoustic Use," Org. Coatings and Appl. Polym. Sci. Proc. 661 (1982). [Pg.57]

In the future, underwater acoustic system research should be designed to identify the mechanisms of bond degradation and to develop accelerated life testing methods and long-term predictive capability. [Pg.684]

Figure 23 Springer-Verlag, Berlin, FRG, from Lauterbom, W. in Cavitation and Inhomogeneities in Underwater Acoustics (Lauterbom, W., Ed.), Springer-Verlag, Berlin, 1980, pp. 84-89. Figure 23 Springer-Verlag, Berlin, FRG, from Lauterbom, W. in Cavitation and Inhomogeneities in Underwater Acoustics (Lauterbom, W., Ed.), Springer-Verlag, Berlin, 1980, pp. 84-89.
Underwater acoustics commenced with theories developed by the nineteenth-century mathematician Simeon-Denis Poisson, but further development had to await the invention of underwater transducers in the next century. [Pg.3]

Underwater Sound. Applications for underwater acoustics include devices for underwater communication by acoustic means, remote control devices, underwater navigation and positioning systems, acoustic thermometers to measure ocean temperature, and echo sounders to locate schools of fish or other biota. Low-frequency devices can be used to explore the seabed for seismic research. [Pg.7]

Anechoic (echo-reducing) coatings to reduce tank-wall reflections are needed in many underwater acoustic test facihties. One effective design utiHzes butyl... [Pg.73]

In underwater acoustics, the metric system has not been universally applied, and a number of nonmetric units are stOlused distances of nautical rmles (1852 m), yards (0.9144 m), and kiloyards speeds of knots (nautical miles per hour) depths of fathoms (6 feet or 1.8288 m) and bearing in degrees (0.01745 rad). In the past two decades, however, there has been a conscious effort to become totally metric, that is, to use meter-kilogram second (MKS) or Standard International units. [Pg.1878]

FIGURE 17.38 Active and passive underwater acoustical signal processing. [Pg.1879]

FIGURE 17.44 The flextensional transducer. (Source Burdic, W.S. 1984. Underwater Acoustic System Analysis, p. 93. Prentice-Hall, Englewood Cliffs, NJ.)... [Pg.1886]

An advantage of data fusion is that the receivers can be located at different ranges (e.g., on two different ships), in different mediums (shallow or deep water, or even at the surface), and at different bearings from the object, thus giving comprehensive information about the object or the underwater acoustic channel... [Pg.1893]

Since World War 11, in addition to military apphcations, there has been an expansion in commercial and industrial underwater acoustic apphcations. Table 17.8 lists the mihtary and nonmilitary functions of... [Pg.1893]

FIGURE 17.50 Sonar frequency allocation. (Source Adapted from Neitzel.E.B. 1973. Civil uses of underwater acoustics. Lectures on Marine Acoustics (AD 156-052).)... [Pg.1894]

Burdic, W.S. 1984. Underwater Acoustic System Analysis. Prentice-HaU, Englewood Cliffs, NJ. [Pg.1895]

Chan, Y.T., ed. 1989. Digital Signal Processing for Sonar Underwater Acoustic Signal Processing, NATO ASI series, series E Apphed Sciences, vol. 161. Kluwer Academic, Norwell, MA. [Pg.1895]

Spindel, R.C. 1985. Signal processing in ocean tomography. In Adaptive Methods in Underwater Acoustics, ed. H.G. Urban, pp. 687-710. D. Reidel. [Pg.1895]

Digital Signal Processing for Sonar, (Knight, Pridham, and Kay, 1981) and Sonar System Technology (Winder, 1975) are informative and detailed tutorials on underwater sound systems. Also the March 1972 issue of The Journal of Acoustical Society of America, Vol. 51, No. 3 (Part 2), has historical and review papers on underwater acoustics related topics. [Pg.1896]

Dubus, B. Low Frequency Magnetostrictive Projectors for Oceanography and Sonar. Proc. 3rd Europ. Conf. on Underwater Acoustics (1996), pp. 1019-1024... [Pg.284]

ASFA Aquatic Sciences and Fisheries Abstracts http //www.csa.com/ (accessed June 16, 2010). ASFA provides coverage of the field since 1971. It covers publications on such topics as dynamical oceanography, underwater acoustics, marine meteorology, marine technology, offshore structures, and underwater vehicles. It is updated monthly by Cambridge... [Pg.143]

Ocean Engineering An International Journal of Research and Development (0029-8018). Published since 1968, this journal covers such areas as design and building of structures, submarine soil mechanics, coastal engineering, fabrication of materials, hydrodynamic properties of shells, ocean energy, propnlsion systems, and underwater acoustics. [Pg.145]

Deng, Y., Beaujean, P.-P.J., An, E., Carlson, E. Task allocation and path planning for collaborative autonomous underwater vehicles operating through an underwater acoustic network. Journal of Robotics 2013, 1-15 (2013)... [Pg.84]


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See also in sourсe #XX -- [ Pg.31 , Pg.32 ]




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