Abstract: An ultrasonic transducer is disclosed that operates efficiently and at low impedance at high frequencies at or near a third harmonic frequency of its piezoelectric crystal. The ultrasonic transducer includes a resonator composed of ceramic material and positioned between a head mass and the piezoelectric crystal.

Abstract: This invention relates to an ultrasonic generator apparatus for generating and transmitting enhanced ultrasonic wave energy of a predetermined frequency to a liquid confined in a container which contains a resonance enhancing disc. Such electroacoustic transducer apparatus or generators are utilized in ultrasonic cleaning equipment. The apparatus are mounted to the side or the underside of the liquid container or mounted in a sealed enclosure which is immersed in a liquid in a container made of metal, plastic or glass. Generators are used in single or plurality of to energize the liquid with sonic energy which in turn transformed into cavitations. In the present invention, the insertion of a resonance enhancing disc between the base of the generator and the piezo electric material provides an increase in intensity of the resonant frequency signals, diminishing periodical shift in frequency and stabilizing piezo electric material temperature.

Abstract: The present invention relates to an aqueous composition and process useful for cleaning and drying ferrous surfaces. According to the invention, a water-immiscible hydrocarbon or non-halogenated organic solvent cleaning step is followed by an aqueous displacement solution (ADS) which contains a surfactant component and a pH modifier component in sufficient amounts to substantially displace the hydrophobic organic solvent residue from the surface of the substrate and prevent its redeposition. The ferrous metal surfaces are then rinsed with hot deionized ultrasonically agitated water which comprises one or more water soluble basic components. This aqueous composition is capable of protecting ferrous metal surfaces form flash rusting after aqueous cleaning or solvent treatments of the surfaces, and particularly during the deionized water rinsing and drying steps.