SONAR APPLICATION

Hard PZT ceramics are characterized by low piezoelectric coefficients, a smaller relative permittivity, minor dielectric losses, lower insulating resistance, high mechanical quality factor and high coercive field strength. Corresponding applications fields are ultrasonic generators with the highest required output powers such as ultrasonic cleaners or transducers for sonar applications. 

The hard PZT piezoelectrics are the most common in sonar applications. 

Medical Ultrasound Many of us have first seen our unborn children or grandchildren thanks to medical ultrasound technology. This application is somewhat related to sonar in that both use pulse echo methods to send and receive signals. However, in this short-range application, transducer arraj can be designed to form images. 

Barium titanate has many important commercial apphcations. It has both ferroelectric and piezoelectric properties. Also, it has a very high dielectric constant (about 1,000 times that of water). The compound has five crystalline modifications, each of which is stable over a particular temperature range. Ceramic bodies of barium titanate find wide applications in dielectric amplifiers, magnetic amplifiers, and capacitors. These storage devices are used in digital calculators, radio and television sets, ultrasonic apparatus, crystal microphone and telephone, sonar equipment, and many other electronic devices. 

PIEZOELECTRICITY. Electric energy created by application of pressure to ceramics of plastics. Devices utilizing this phenomenon are gas flame igniters, ultrasonic welding tools, and sonar navigation aids. 

Thellmann reports jin Ref 16 on the non-energetic ordn applications of Ti fabricated into components by PM. These include a Ti sonar reflection plate, 20mm shell casings, fastening bolts of Ti and a Ti-6A1-4V lens housing for the Maverick missile... 

The major advantage of syntactic foams is the high strength-to-weight ratios. This advantage has ied to applications in deep-submergence vehicles for hydrospace use (7), aerospace applications such as interior floor panels of aircraft (8), nose cones, fins, and bodies of rockets, sonar windows (some acoustic properties of the foam are similar to those of sea water, radomes, etc. (11). 

Military applications 15-50W Central power source, sonar, radio set, noctoviser, radar, power supply for weapon systems Secondary batteries Time of operation, volume + weight, self discharge... 

Gysling, D. and Loose, D. (January 2004). Clamp-on sonar based entrained air measurement for pulp and paper applications. 90th Annual of Pulp and Paper Technical Association of Canada. Montreal, Quebec Canada, vol. B, 109-111. 

A large number of apphcations have been proposed for piezoelectric polymers. The types of applications can be grouped into live major categories sonar hydrophones, ultrasonic transducers, audio-frequency transducers, pyroelectric sensors, and electromechanical devices. The principal polymers of interest in these applications are PVDF and copolymers of vinylidene fluoride and trifluoroethylene. 

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