Abstract: Methods and apparatus for controlling the movement of materials having different physical properties when one of the materials is a fluid. The invention does not rely on flocculation, sedimentation, centrifugation, the buoyancy of the materials, or any other gravity dependent characteristic, in order to achieve its desired results. The methods of the present invention provide that a first acoustic wave is propagated through a vessel containing the materials. A second acoustic wave, at a frequency different than the first acoustic wave, is also propagated through the vessel so that the two acoustic waves are superimposed upon each other. The superimposition of the two waves creates a beat frequency wave. The beat frequency wave comprises pressure gradients dividing regions of maximum and minimum pressure. The pressure gradients and the regions of maximum and minimum pressure move through space and time at a group velocity.

Abstract: A biosensor includes an elastic substrate, a sensor tip, and a piezoelectric actuator. The sensor tip is mounted on one end of the substrate. The piezoelectric actuator is provided on the other end of the substrate.

Abstract: A holder for a beaker insertable in a container of an ultrasonic cleaning device for cleaning medical or dental tools, dentures, or the like, in a cleaning solution contained in the beaker. The holder includes a ring-shaped member, which receives the beaker and a supporting U-shaped wire which supports the bottom wall of the beaker and is removably-connectable to the ring-shaped member.

Abstract: An ultrasonic cleaning apparatus for household use is small and compact, easy to use, and inexpensive to buy and to operate. It includes a base, an electric circuit supported upon the base, a circumferential housing extending upward from the base, a liquid tank within the upper portion of the housing, and an electro-mechanical transducer secured to the bottom side of the liquid tank and coupled to the eletric circuit to be driven thereby. The periphery of the liquid tank is supported from the housing in secure liquid-sealing relationship so as to protect the electric circuit from any liquid spillage. A removable cover fits over the top of the housing and covers the liquid tank and contents.A separate feature of the invention is a removable jewelry basket which may be positioned within the liquid tank for holding jewelry that is being cleaned, but can then be rested above the tank while the liquid drains out and the jewelry dries.

Abstract: A wedge-shaped vibration-transmitting plate is located between the bottom wall of a cleaning tank and an ultrasonic transducer which is operable to produce vibratory energy in a liquid bath in the tank. The wedge-shaped plate diversifies the phase of initially in-phase energy waves produced by the transducer and causes waves of different phase to propagate upwardly through the liquid. As a result of the phase diversification, the concentration of high and low power levels at various depths in the bath is reduced so that cleaning action over the span of the vertical dimension is more uniform. In addition, the overall action of wave reflection at the upper surface of the bath fluctuates through a smaller range when the depth of the bath changes. This enables the transducer to be energized with a more stable input power.

Abstract: An ultrasonic cleaning device comprises an ultrasonic pump having a hollow cover forming a spouting port in a narrow portion thereof, an ultrasonic vibrator in a wide portion thereof and a liquid supply port in a side portion thereof. An oscillator is connected to the ultrasonic vibrator. One part of the ultrasonic wave from the vibrator is passed through the spouting portion straight and the other part of the ultrasonic wave is reflected on the inside of the cover and is passed through the spouting port. An object or objects are opposed to the spouting port of the cover.

Abstract: Sieving apparatus has a piezo-electric transducer (1) directly bonded to a grating (100), the supply to the transducer (1) being controlled by sensing resonance of the grating (100) and any deviation therefrom and controlling the supply to maintain resonance.

Abstract: A preform wire for fiber reinforced metal composite consisting of a metal/silicon carbide fiber composite material is light in weight and excellent in strength and elasticity, and can be easily obtained by impregnating a silicon carbide fiber bundle with a molten metal which is kept vibrated by means of an ultrasonic wave vibration apparatus having a hole for cooling water or a cooling-water jacket located at the node of the half-wavelength of the ultrasonic wave created by the vibration apparatus.

Abstract: The invention relates to an apparatus of the vibrocompactor type for compacting carbonaceous blocks, and which comprises a vibrating table on which a carbonaceous paste is to be disposed, a heavy mass located below the table, and damper means located between the table and the mass for suspending the table above the mass. According to the invention, the damper means comprises inflatable pneumatic cushions. These cushions may be connected in parallel permanently to a source of fluid under a controllable pressure, or alternatively may be connected in parallel during the inflation of the cushions, and then isolated individually or in groups from the source of fluid. The apparatus may also include a means for measuring the pressure in each cushion or in a group of cushions, and a means for signalling the drop in pressure in each cushion or group.

Abstract: A vibration generator (50) with a magnetically attractable mass (98) is loosely disposed within a substantially cylindrical cavity of a housing (54). An array of electromagnets (60-90) is circumferentially spaced around the housing cavity. The electromagnets (60-90) are sequentially energized in a predetermined sequence to magnetically attract the loosely disposed mass (98) toward an energized electromagnet, thereby causing the magnetically attractable mass (98) to orbit around the array of electromagnets, imparting centrifugal force to the housing (54) which in turn generates vibration energy.

Abstract: Disclosed is a fluid flow sonic energy reactor particularly adapted for blood hemolysis. An ultrasonic generator is provided with a tapered resonator, the small diameter end of which forms one planar surface of the reactor cavity. The reactor includes an anvil, one end of which has a central surface region that is closely spaced from the small diameter end of the tapered resonator. An O-ring is in contact with the periphery of the small diameter end of the resonator as well as the adjacent surface of the anvil to form therebetween a sealed chamber. First and second bores extend through the anvil to the central surface region thereof to introduce fluid into the chamber and remove fluid therefrom.

Abstract: A metallic glass ribbon of the formulaFe.sub.w B.sub.x Si.sub.y C.sub.zwherein0.78.ltoreq.w.ltoreq.0.83,0.13.ltoreq.x.ltoreq.0.17,0.03.ltoreq.y.ltoreq.0.07,0.005.ltoreq.z.ltoreq.0.03,andw+x+y+z=1,is annealed to remove mechanical strains and exposed to a magnetic field in the plane of the ribbon and transverse to the long axis of the ribbon. The resulting metalic glass ribbons have very large magnetic coupling coefficients (k.sub.33 >0.9). The treated ribbons are useful in magnetostrictive transducers and in passive listening devices such as hydrophones or pressure sensors.

Abstract: Methods and apparatus for controlling the movement of materials having different physical properties when one of the materials is a fluid. The invention does not rely on flocculation, sedimentation, centrifugation, the buoyancy of the materials, or any other gravity dependent characteristic, in order to achieve its desired results. The methods of the present invention provide that a first acoustic wave is progpagated through a vessel containing the materials. A second acoustic wave, at a frequency different than the first acoustic wave, is also propagated through the vessel so that the two acoustic waves are superimposed upon each other. The superimposition of the two waves creates a beat frequency wave. The beat frequency wave comprises pressure gradients dividing regions of maximum and minimum pressure. The pressure gradients and the regions of maximum and minimum pressure move through space and time at a group velocity.

Abstract: A polymerization process and reactor utilizes a high power shock producing device for introducing high energy pulses shock waves to a body of constituent monomer molecules for breaking and making bonds. The high energy pulsed shock waves are generated and introduced into a body of the constituent monomerics to break the molecular bonds and create new bonding by a hollow piezoelectric shock tube mounted in an autoclave. A stirrer is operated simultaneously to stir away the new bonding sites and make them available for linkage to another monomer contained in the reactor vessel.

Abstract: An ultrasonic washing machine for tableware is provided with an ultrasonic generator and an air bubble supplying device in a tub. Air bubbles are sent out from holes of an air bubble supplying device to reflect ultrasound when ascending in water in the tub. Other air bubbles dissolve in the water, but arise on the tableware again by the cavitation effect of the ultrasound, which makes dirt or alien matters release from the tableware. The air in the water consumed by the cavitation of the ultrasound is fed into the water from outside from time to time. Therefore, cleaning of the tableware by air bubbles is carried out constantly and no detergent is needed in washing the tableware.

Abstract: An ultrasonic washing machine as an air bubble supplying device and an ultrasonic generator. The ultrasonic generator works with textile products such as fabrics, yarns, ropes, etc. placed in a tub filled with water. Air bubbles produced by the cavitation effect of the ultrasound cling to the surface of the textile products and help remove stains, alien matter, etc. adhering to them. Part of the air, fed from the outside by an air bubble supplying device, constantly dissolves in the water, whereby the air consumed by the cavitation is supplemented; the rest of the air, not dissolved in the water, diffuses the ultrasound when ascending in the water as bubbles, which serves to greatly improve the washing effect.

Abstract: A humidifier for humidifying air comprises a storing member for storing water, an atomizing device for atomizing the water supplied from the water storing member, a blower for blowing air into the atomizing device, a blowoff member for dispersing atomized water particles into air, a connecting member for connecting the blowoff member with the atomizing device, and an inhibiting member for inhibiting capillary action of the water in the connection member.

Abstract: A contact lens cleaning and disinfecting apparatus with a cavity (14) in which a contact lens is to be cleaned by an aqueous non-chemosterilant liquid such as a saline solution. An ultra-sonic transducer (20) applies vibrations to the cavity (14). The oscillator driving the transducer includes a transformer feedback circuit using one or more cores of high magnetic permeability and low core loss to give a stable resonant frequency. A timer (34) may be driven from this resonant frequency. In one embodiment the cavity (14) and the sealing cap (16) may be removable together with the transducer (20) from the rest of the housing of the apparatus so that lenses can be transported conveniently after cleaning and before use. According to another embodiment the waste heat from power transistors (Q2, Q3) can be used to heat the cleaning liquid in the cavity.

Abstract: An ultrasonic device comprises at least one transducer and a probe having a first active part adapted to be immersed in a medium, an adapter part for matching the impedance of the probe to the medium and an end surface on the adapter part adapted to emit ultrasonic waves longitudinally into the medium. The first active part lies between the end surface on the adapter part, at which is located a peak of the longitudinal ultrasonic waves, and a limiting part at which is located a node of the longitudinal ultrasonic waves. It comprises a second active part adapted to emit ultrasonic waves radially into the medium and at which is located one or more peaks of the radial ultrasonic waves.

Abstract: A housing supports a tray for slidable movement of the tray within the housing. The tray and the housing may be paramagnetic. The tray is shaped to define at least one cup for receiving a contact lens and cleaning fluid. The tray may be supported on a resiliently compressible pad which is in turn supported on a ledge forming a part of the housing. A slug is supported by, or embedded in, the tray to provide for a movement of the slug with the tray. The slug may be magnetizable and may be displaced from an armature and a coil enveloping the armature. When the coil is energized, it magnetizes the armature. The energizing of the armature causes the slug to be attracted to the armature in a direction to compress the pad. When the coil is de-energized, the compressed pad expands to move the tray away from the armature. In this way, the tray is vibrated in directions to displace the contact lens from the wall of the cup and to agitate the cleaning fluid so that all of the surfaces of the contact lens are cleaned.

Abstract: An improved apparatus for coupling ultrasonic energy from piezoelectric transducers to a liquid medium for use in cleaning or etching processes. The apparatus includes a vibration coupling plate which may be partially immersed in the liquid medium, while the upper, nonimmersed end of the plate is configured to support a pair of piezoelectric transducers disposed at 45 degree angles with respect to the lengthwise axis of the plate. The beams of ultrasonic mechanical wave energy are therefore reflected back and forth from the side edges of the plate and dispersed over a wider angle in the liquid.

Abstract: A sample holder to influence the texture and size of particles of a sample and/or to induce crystallization process in cooled liquids or gases. The vibrational energy of an ultrasonic radiator is transferred to the sample. In this manner, identification of samples by powder diffractometry are easier, quantitative determinations are more precise, and diffractometry of samples with a melting point below room temperature are possible.

Abstract: Apparatus and method is illustrated for servicing a loom reed at the loom with the warp yarns remaining in the reed. The apparatus includes a cleaning tank for ultrasonically cleaning the loom for reed as well as a tank for ultrasonically rinsing the loom reed. An elongated receptical for air cleaning and drying the loom reed is also illustrated.

Abstract: A solution cavitation creating device is located within a chamber having a liquid solution therein to create cavitation and a sound reflecting and suppression structure is located within the chamber to quiet the cavitation in the chamber and reflect the wave form into the liquid solution.

Abstract: Contact lens cleansing apparatus comprises at least one cavity for containing a contact lens together with cleansing a liquid. An ultrasonic transducer applies ultrasonic frequency mechanical vibrations to the liquid and lens contained in the cavity. Oscillating means for driving ultrasonic transducer at a substantially stable resonant frequency includes a dual ferrite core transformer feedback circuit which minimizes energy consumption. There is also a timer whose operation is controlled from the oscillating means. Simultaneous cleaning and sterilizing of a contact lens is achieved.

Abstract: High frequency ultrasonic energy is applied to a liquid medium to produce low micron size cavitation in the liquid for enhancing the cleaning or etching action of exposed surfaces within the liquid. An ultrasonic transducer is bonded to a vibration coupler which is formed of a material that is inpervious to the liquid medium and functions to efficiently transmit the ultrasonic vibrations to the liquid medium. The coupler is partially immersed in the liquid while maintaining the transducer elevated above the liquid.

Abstract: An apparatus is disclosed for emulsifying and atomizing fluid fuels with secondary fluids, in particular water, which has improved characteristics over commercially available apparata especially as regards the maximum mixable proportion of secondary fluid without undergoing efficiency deterioration, stability, and homogenization level. The apparatus comprises a first mechanical cavitation chamber wherein the fluid fuel and water are mixed and pretreated, a combined action cavitation chamber of a mechanical and electromagmetic type, and a final cavitation chamber, wherein homogenization of the fluid is completed. The combined actions within the intermediate chamber are achieved by generating within the chamber a centered corridor resulting from the effects of high pressure and vacua, and of an appropriate magnetic field. The invention also provides a method of treating fuel fluids by means of the apparatus illustrated.

Abstract: The invention concerns the promotion of stirring of molten material (e.g. steel) within a receptacle such as a mould, vessel, or shell of a partially solidified metal strand emerging from a mould. Polyphase alternating currents are passed through electrically conductive elements located on, or forming part of, or lying adjacent to the receptable surface by joining both current connections of one or more transducers to the conductive elements to cause electrical currents to flow along paths in the elements to induce magnetic fields within the molten material and to promote stirring of the material.

Abstract: A process of preparing ceramic powders for sintering comprises the steps of dispersing ceramic powders and sintering aids in a low-boiling dispersing liquid to form a suspension, ultrasonically vibrating the suspension to defloculate agglomerates which may have formed, and continuing the ultrasonic vibration until the dispersing liquid is evaporated.

Abstract: Process and means to enhance fluid coverage of surfaces in industrial applications. Generation of a directed force field is employed to provide removal of surface air, improve surface wetting of a fluid, and consolidation and densification of fibrous structures.Apparatus of the invention is described which provides vibratory forces of appreciable magnitude and super-audio frequency and applied to solid, fluid and gaseous combinations, to displace surface gas and promote fluid contact with the solid surface. Apparatus of the invention facilitates the generation and application of the vibratory energy to composite structures of synthetic or natural fibers with a fluid resinous material.

Abstract: Apparatus and processes are disclosed for treating materials by exposure thereof to sonic or ultrasonic oscillations produced by oscillating plates which form part of a processing chamber and which are each activated by a plurality of transducers adjacent thereto. The transducers are excited by an electronic circuit capable of driving each transducer at selectable frequencies, phase relationships and amplitudes. The invention also comprises processes for the treatment of materials by exposure thereof to oscillating plates excited at predetermined combinations of frequencies, phases and amplitudes.

Abstract: A method of producing and radiating ultrasonic energy in fluids, in particular for irradiating cleaning baths, having an ultrasonic generator and a converter or transducer associated therewith, is improved with respect of its mode to operation and efficiency by a resonator being immersed in the fluid and the fluid being irradiated by radial components which are produced in the expansion nodes of longitudinal waves of the resonator. A corresponding apparatus with an ultrasonic generator, in accordance with the invention, has a resonator (1) which is connected to a sound transducer (9) towards the fluid or the bath (7) and which is tuned in its longitudinal axis (M) to an integral multiple of the acoustic operating half-wave length.lambda./2, to produce transverse compressions at the expansion nodes thereof. The resonator (1) is preferably in the form of a hollow profile of round cross-section and may possibly also contain further resonators.

Abstract: An ultrasonic cleaning system utilizes a manufacturing technique wherein one or more piezoelectric elements are fused, secured by a gold sputtering technique, or attached by electrochemical deposition to an associated metal surface, whether it be a metal cleaning tank or an electrode, by a gas-tight joint or connection, eliminating the necessity of utilizing conventional techniques that require bonding of the element or elements to the associated metal surfaces by epoxy compounds or the like. The novel technique is practiced, in some forms of the invention, by molding the piezoelectric elements integrally with ceramic materials utilized for the liquid cleaning tank itself, and thereafter polarizing the area or areas that are to be made piezoelectric. In other forms, a metal cleaning tank may be used, but in every instance the fusing of the piezoelectric mixture to the tank walls and/or electrodes is accomplished during the firing of the ceramic material of which the piezoelectric element is formed.

Abstract: In the developing of light sensitive plates, the plates are passed through a tank of developing liquid which is subject to ultrasonic waves to assist the developing action. The tank is preferably protected from the atmosphere to hinder degradation of the developing liquid.

Abstract: The present invention relates to a tank for the treatment of offset plates by ultrasounds. An elongated rectilinear passageway is limited by a lower wall constituted by a vat with a peripheral flange and by an upper wall constituted by an inverted vat with a peripheral flange, a seal incorporating an elastic lip being tightened between inlet and outlet openings, a bath reservoir being formed in one of the vats to contain an ultra-sound generator, so that the plates to be treated, propelled by pairs of rollers, pass through the developer bath whose volume is minimum, in a straight line.

Abstract: Ultrasonic transducer apparatus for cleaning applications and method for cleaning wafers of semiconductor material in which the method includes positioning the wafer proximate to but closely spaced away from a cleansing face of the ultrasonic transducer, supplying space between the cleansing face and the wafer with a cleansing fluid through an orifice in the cleansing surface and ultrasonically vibrating the cleansing face transversely to the wafer by applying an electrical signal to piezoelectric material symmetrically disposed about the orifice in the cleansing face via which the cleansing fluid is supplied, with the ultrasonic transducer including piezoelectric material symmetrically disposed with respect to the orifice in the cleansing face through which the cleansing fluid is supplied.

Abstract: This apparatus is used in industrial treatment processes for fluids constituted of several chemical components which must be perfectly homogenized before taking part in processes, when it is necessary to achieve saturation conditions closest to the stoichiometric conditions. This apparatus is suitable to generate ultrasonic waves of manifold frequencies depending on the viscosity of treated fluid and with its flux velocity inside a duct. The apparatus consists in an ultrasonic waves generator which sends treatment-waves in a duct, to homogenize the arriving fluid by means of a newly conceived transducer which, in the meantime, sends also a beam of controlling waves to detect the achieved homogeneity of treated fluid. Controlling waves are analyzed by binary circuits which accept or reject signals, maintaining or changing the balance between received signals and generated signals until the right frequency of waves is sent to treatment transducer to insure the proper homogenization of the fluid.

Abstract: The present invention provides an ultrasonic processing device which comprises one or more sets each including a wide horn which resonantly vibrates in a 1/2 wave length in a longitudinal direction and in a 1/2.times.n wave length in a widthwise direction thereof, and an ultrasonic vibrator which is joined either to an intermediate point of the wide horn at which amplitude of vibrations is maximum in the distribution thereof along the widthwise direction or to a point at a widthwise end of the wide horn at which amplitude of vibrations is maximum in the distribution thereof along the widthwise direction. Thus, at an end of the wide horn, maximum and minimum values may alternately appear by every 1/4 wave length distance over the entire width thereof and hence vibrations of the wide horn can be considered generally uniform over the entire width thereof.

Abstract: A system for providing homogenized fluids of fuel and water utilizes a chamber (70) in which the fuel and water is loaded in predetermined quantities. The chamber contains heater (75) which is electrically activated to convert the liquid fuel and water to their vapor states. The chamber also contains a transducer (74) which vibrates the liquified composition of the fuel and water vapors at high frequency rates so as to additionally homogenize it prior to being transferred to storage vessel (96). A vaporizer (99') may be connected to the storage vessel so as to be fed by the homogenized liquid when this system is used in conjunction with an internal combustion engine. The system may provide mechanism (77, 79) for evacuating chamber (70) prior to loading the fuel and water into such chamber.

Abstract: An acoustic resonator apparatus for efficiently transmitting acoustic energy from a plurality of acoustic transducers to a fluid passing through a cylindrical shell. A plurality of pairs of acoustic transducers are mounted on the cylindrical shell, each transducer of a pair being 180.degree. away from the other transducer of the pair, and each pair being associated with another transducer pair which is disposed 90.degree. away from such pair. Each of the transducer pairs is excited with energy of the same frequency and magnitude, but transducer pairs which are disposed 90.degree. from each other are excited with energy which is out of phase by 180.degree..

Abstract: Process for the thermal treatment of powdered and granulated catalysts, catalyst intermediate products, and inorganic substances, which are usable as constituents of catalysts or as auxiliary agents for the production of catalysts. The known process material is placed on a heated vibrating conveyor and there, in the form of a thin layer, in which the particles of the process material are moved with a larger horizontal and a smaller vertical component, heated and allowed to cool either outside the vibrating conveyor or in a separate vibrating conveyor or in the outlet portion of the first vibrating conveyor.

Abstract: A relative heavy immiscible fluid is used with water or a relatively light treating fluid in a treating tank under ultrasonic vibrating conditions and objects to be treated are immersed in the treating fluid.

Abstract: A method of treating material in a vessel includes the steps of vibrating the vessel to produce oscillatory displacement of the vessel wall; and transmitting such displacement to material in the vessel. The vessel may comprise a tube having a tuned cavity in which material is treated; or the vessel may contain relatively movable solid bodies to which the vibration is transmitted to grind or emulsify material flowing between the bodies; or, the vessel may contain a pumping member to which vibration is transmitted to cause material pumping displacement of that member.

Abstract: Apparatus for homogenizing a liquid, the body of the apparatus having therein an homogenization chamber within which is located a blade caused to vibrate by a jet of liquid to be homogenized impinging thereon. Magnetostrictive or piezoelectric devices are utilized to impart vibrational energy to the liquid in the chamber additional to that imparted thereto by the blade.

Abstract: A sonic agglomeration system wherein high sound intensity and resonance are maintained with a low power input. These functions are attained through the use of a chamber feed-horn design that promotes resonance and maximized the efficiency of sound transfer between a sound producing compression driver and a resonant chamber. A digital controller maintains efficient resonance in the chamber and an efficient agglomeration rate constant by making adjustments in the frequency, sound amplitude and nuclei injection rate of the system.

Abstract: A process and an apparatus wherein the liquid to be homogenized or emulsified with the use of little energy relative to the amount of liquid is fed into an ultrasonic chamber (1) in which it is caused to flow as a thin layer across one or more ultrasonic generator surfaces (6), the liquid flow thus treated being admixed continuously with the remaining portion of the liquid within the chamber, finished homogenized/emulsified liquid being simultaneously carried past an ultrasonic generator surface (6) and discharged from the chamber (1).

Abstract: A liquid agitation apparatus comprises a transparent reaction vessel for containing a reaction solution to be examined, a holder for holding the reaction vessel, and a rotary solenoid for imparting a mechanical vibration to the holder. The mechanical vibration from the rotary solenoid is effective to agitate the reaction solution automatically.

Abstract: A system for providing homogenized mixtures of hydrocarbon fuel and water utilizes a chamber in which the fuel and water is injected in a predetermined ratio. The chamber contains a transducer which is electrically excited and therefore vibrates the mixture at high frequency rates so as to homogenize it prior to the mixture being fed to a fuel injector or carburetor.

Abstract: Apparatus for the surgical removal of tissue is disclosed comprising a handpiece having a resonant vibrator with a magnetostrictive stack and connecting body encompassing a hollow elongated tool which is ultrasonically vibrated at its tip longitudinally to a peak to peak stroke of at least 0.005 inches at about 25,000 cps (25 KHz). A generator powers the vibrator and is automatically controlled at the frequency to maintain the resonant vibration. Aspiration is provided by suction through the hollow tool at its tip, and a manifold enclosing the tool end of the handpiece provides irrigation.

Abstract: A transmission cable for use with an ultrasonic device such as an ultrasonic machining device is provided. The transmission cable of the present invention comprises a plurality of fine metallic wires coupled between the output terminal of an ultrasonic oscillation generating source and the input terminal of a terminal machining tool of the ultrasonic device. The metallic wires are covered with a flexible tubular member which may preferably be filled with a liquid so that the lateral vibrations of the wires are suppressed thereby. This type of cable is particularly advantageous in that the ultrasonic oscillations of the wires forming the cable can be transmitted efficiently to the terminal machining tool and the cable is suitable and convenient for carrying out the ultrasonic machining operations with the machining tool.