An apparatus for disinfecting products is disclosed herein. The apparatus comprises a tank for holding a liquid for receiving microorganisms from the products. The tank comprises a barrier separating the tank to provide two regions of liquid, the two regions of liquid comprising a first region and a second region, wherein the first region is arranged to provide an open channel for the liquid through the tank to enable a product to be carried into, along, and out of a flowpath through the channel; and the second region holds liquid adjacent to at least one ultrasonic transducer for providing ultrasonic energy to the product via the liquid in the second region and through the barrier.

A method for exciting sound-wave producing transducers (7) which have operating frequencies defining a transducer frequency range, in which a generator (9) produces an electrical excitation signal for the transducers (7), these electrical excitation signal being fed to the transducers (7), wherein the generator (9) carries out frequency sweeps in a frequency sweep range between a minimum frequency (f.sub.min) and a maximum frequency (f.sub.max) with an adjustable sweep rate, with a target frequency (f.sub.Ziel) being defined within said frequency sweep range, this method being characterized in that the minimum frequency (f.sub.min), the maximum frequency (f.sub.max) and the target frequency (f.sub.Ziel) are selected in such a way that a first frequency difference (f.sub.1) between the minimum frequency (fmin) and the target frequency (f.sub.Ziel) differs in terms of magnitude from a second frequency difference (f.sub.2) between the maximum frequency (f.sub.max) and the target frequency (f.sub.Ziel) within a number of frequency sweeps, and wherein the minimum frequency (f.sub.min) and/or the maximum frequency (f.sub.max) and/or the target frequency (f.sub.Ziel) is/are modified after at least one frequency sweep in such a way that an arithmetic mean of the first frequency differences (f.sub.1), formed over all frequency sweeps carried out, and an arithmetic mean of the second frequency differences (f.sub.2), formed over all frequency sweeps carried out, are substantially the same in terms of magnitude.

Methods and devices are described for driving ferroelectric perovskite oxide crystals to achieve polarization inversion with reduced coercivity. In some embodiments, the anisotropy in the potential energy surface of a ferroelectric material is employed to drive polarization inversion and switching with a reduced coercive field relative to uniaxial excitation. In some embodiments, polarization inversion with reduced coercivity is produced via the application of an electric field that exhibits a time-dependent orientation, in contrast with conventional uniaxial electrical excitation, thereby causing the central ion (and the crystal structure as a whole) to evolve along a lower-energy path, in which the central ion is driven such that it avoids the potential energy maximum. This may be achieved, for example, by applying at least two non-parallel time-dependent voltages (e.g. bias, potential) such that orientation of the electric field changes with time during the switching cycle.

Methods and apparatus for cleaning brushes quickly, comfortably and efficiently are disclosed. The apparatus contains at least one cleaning chamber comprising a plurality of cleaning elements disposed within the chamber that contacts the brushes during cleaning, the cleaning chamber in contact with a) a drive and a motor that can deliver rapid reciprocating motions to the cleaning elements, b) a solvent flow system, and c) a removable brush holder connected to a motor that turns the brushes slowly over the cleaning elements. Rapid reciprocating motions of the cleaning elements, continuous flow of a solvent over the brushes to be cleaned and a slow rotation of the brush itself over the cleaning elements achieve rapid cleaning of brushes with little damage to the brush itself. A removable brush holder that can accommodate many different kinds of brushes in the same slot extends the functionality and comfort of using the brush cleaner.

A novel mode of ultrasonic oscillation is generated in a Langevin ultrasonic transducer comprising a metal block, a metal block provided with a supporting means protruding in a ring shape on its side surface, and polarized piezoelectric elements fixed between these metal blocks, by connecting the ultrasonic transducer to a base via the supporting means, whereby supporting the ultrasonic transducer on the base in a restrained state, and applying to the piezoelectric elements a voltage having such frequency that the ultrasonic transducer generates an ultrasonic oscillation with back-and-forth motion in a direction perpendicular to plane surfaces of the piezoelectric elements which has no oscillation node within the ultrasonic transducer; this novel ultrasonic oscillation mode is utilized for performing ultrasonic machining methods as well as for ultrasonic transmission method.

An apparatus for processing articles with acoustic energy and a method of constructing a transducer that utilizes a composite of piezoelectric pillars. In one embodiment, the invention is a method of constructing a device for generating acoustic energy comprising: providing a layer of supporting material; positioning a piezoelectric material atop the layer of adhesive material; cutting the piezoelectric material into a plurality of pillars so that spaces exist between adjacent pillars; and filling the spaces with a resilient material to form a composite assembly.

A device for cleaning water wells comprises a downhole tool composed of an electrohydraulic unit (7) with an oscillatory circuit and an ultrasonic unit (4) with an electroacoustic transducer (3) arranged successively in a single housing, sensors of pressure (10) and flow (11), a hydrophone (12), a pump, an ultrasonic generator (13), a pulse generator (14), monitoring equipment (15) for the sensors, a downhole tool control unit (16) equipped with a synchronizer of operation of the electrohydraulic unit (7) and the ultrasonic unit (4), and also with a device for controlling pulse width, beating frequency and spectrum of the signal of the oscillatory circuit of the electrohydraulic unit in order to change the treatment zone. Furthermore, a discharge chamber (8) and a protective cap (9) are arranged in the bottom part of the downhole tool.

An ultrasonic cleaner is provided. The ultrasonic cleaner includes: a first ultrasonic vibrator configured to generate a first ultrasonic wave; a first oscillator configured to drive the first ultrasonic vibrator; a wash tank configured to store a detergent solution; and an attenuation mechanism configured to damp vibration of the wash tank. The wash tank includes a parabolic surface which is a recessed surface facing a vibration surface of the first ultrasonic vibrator, and is configured to reflect the first ultrasonic wave to a focal position where an object to be cleaned is placed. The vibration of the wash tank is generated by the first ultrasonic wave impinging on the wash tank.

Acoustophoretic devices for separating particles from a non-flowing host fluid are disclosed. The devices include a substantially acoustically transparent container and a separation unit, with the container being placed within the separation unit. An ultrasonic transducer in the separation unit creates a planar or multi-dimensional acoustic standing wave within the container, trapping particles disposed within the non-flowing fluid and causing them to coalesce or agglomerate, then separate due to buoyancy or gravity forces.

This present application relates to a system for delivering megasonic energy to a liquid, involving one or more megasonic transducers, each transducer having a single operating frequency within an ultrasound bandwidth and comprising two or more groups of piezoelectric elements arranged in one or more rows, and a megasonic generator means for driving the one or more transducers at frequencies within the bandwidth, the generator means being adapted for changing the voltage applied to each group of piezoelectric elements so as to achieve substantially the same maximum acoustic pressure for each group of piezoelectric elements. The generator means and transducers being constructed and arranged so as to produce ultrasound within the liquid. Such a system may be part of an apparatus for cleaning a surface of an article such as a semiconductor wafer or a medical implant.