On Ultrasonics Page 4:

    Foaming and Aerosoling - moved 28 May 02 from Page 1A.

    Ultrasonic Propulsion (Propulsive Force) - Moving Material.

    Ultrasonic Fountains - Atomization, Nebulization, Humidification,
        Misting, Particle Creation and Sizing.

    Ultrasonics and Nuclear Fusion.

On Ultrasonics Page 5:

    Ultrasonic Whistles (Nozzles, Atomizers, Nebulizers).

On the Ultrasonic Cleaning page:

    ULTRASONIC CLEANING {in process}.

        Immersible Transducers.

        What's New?.

On this ULTRASONICS GLOSSARY page:

    ULTRASONICS GLOSSARY {in process}, (now with alphabetical index).

ULTRASONICS BIBLIOGRAPHY
        Ultrasonic Bibliography Page 1 - Reference Books on Acoustics, Vibration, and Sound.
        Ultrasonic Bibliography Page 2 - Sonochemistry.
        Ultrasonic Bibliography Page 3 - Selected Articles.

CALL FOR CONTRIBUTIONS:  I am writing a book on "High-Intensity Ultrasonic Technology and Applications" (intended for Marcel Dekker's "Mechanical Engineering Series", edited by Profs. Lynn L. Faulkner and S. Bradford Menkes).  This book will focus on the practical application of power (high intensity) ultrasonics, the use of ultrasonic energy to change materials.  Contributions are welcome.

THE CAVITATION BUBBLE

[image from University of Washington, Applied Physics Laboratory (Lawrence Crum, Ph.D.)
- bubble diameter approximately 1mm]

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You may wish to visit the main Ultrasonics page, the succeeding page and the next succeeding page, with more on ultrasonics, as well as the Ultrasonics Cleaning page {also in process}.

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ULTRASONIC GLOSSARY

[Terms and definitions may overlap and even be redundant;
such is the nature of terminology in this complex little field.]

Alphabetical Index to Ultrasonics Glossary

(A) (B) (C) (D) (E) (F) (G) (H) (I) (J) (K) (L) (M)
(N) (O) (P) (Q) (R) (S) (T) (U) (V) (W) (X) (Y) (Z)

[A]

Acoustic  -  having to do with the energy of sound waves.

Acoustics  -  the science and application of acoustic energy.

Active Tank  -  an ultrasonic tank which has been activated to produce cavitation (cf. Still Tank, terms coined by Berliner).

Amplification  -  the increase (which can be negative) of mechanical amplitude from one end of an acoustic element to another.

Amplifying Element  -  a part of a stack or convertor which boosts (or decreases) the amplitude of vibration of the output end.

[B]

Back  -  syn. Rear, q.v.

Bath  -  syn. Tank, q.v., or the contents of the liquid tank or container.

Blanketing  -  that limiting phenomenon in the cavitation field in which the density of the bubble cloud is such that no further cavitation takes place when additional energy is introduced (analgous to the phenomenon at the temperature of thermal boiling, above which no further change of state occurs (term coined by Berliner  -  see text).

Blanketing Threshold  -  that intensity of cavitation at which the blanketing phenomenon occurs; for practical purposes, the blanketing threshold may be considered a relative term based on the efficiency of conversion from increased radiated energy to increased cavitation (term coined by Berliner  -  see text).

Bubble  -  a spherical volume of gas or vapor in a liquid but also commonly used to refer to a spherical void in a liquid.

Bubble Cloud  -  a cloud of cavitation bubbles which hovers in front of an activated radiating surface.

[C]

Cavitation  -  the sequential formation and collapse of vapor bubbles and voids in a liquid subjected to acoustic energy at high frequency and intensity (analgous to thermal boiling but without the associated rise in temperature of the mass of liquid, although localized temperatures on the molecular level can be extremely high).

Cavitation Field  -  that volume, within a processing container or flow system, in which active cavitation is generated by the radiating surface.

Crystal  -  the piezoelectric element(s) in a stack which expands and contracts in an alternating (charged) electrical field, thus inducing vibration.nbsp; In low-powered ultrasonic cleaning tanks, crystals are sometimes bonded directly to the diaphragm (tank bottom or side wall).

Convertor (also Converter)  -  the combination of transducer elements, front driver, and (where so fitted) rear driver in a stack, together with a housing and electrical connections or cabling, which together with a horn forms a probe.

Cup Horn  -  a form of ultrasonic bath in which energy is imparted by an inverted horn sealed into the bottom of a water jacket or cup (see text).

[D]

Diaphragm  -  the side wall or bottom of an ultrasonic cleaning tank or the active surface of an immersible transducer or other radiating acoustic device that transmits ultrasonic energy from the stack or transducer into a liquid bath (analagous to the diaphragm in an early telephone), in effect thus forming the radiating surface  -  use of term in this fashion coined by Berliner  -  see text).

[E]

Electrode  -  in piezoelectric and similar systems, the means, usually thin metal plates, by which electrical energy is introduced to the faces of the transducer crystals.

Electrostrictive  -  syn. Piezoelectric, q.v.

[F]

Forward  -  arbitrary convention (by Berliner et al.) for direction in a transducer, stack or convertor away from the longitudinal center or crystals toward the radiating surface or tip.

Front  -  syn. Forward, q.v.

Front Driver  -  that set of elements forward of the transducing elements in a stack which (usually) amplifies the vibrational energy and transmits it to the horn or output end.

[G]

Gain Factor  -  the factor by which the gain (amplification) of a final radiating surface measured against the amplitude of the initiating device, such as the output surface of the front driver of a welding or processing stack, is given.

Generator (syn. Power Supply)  -  that device which powers and controls the convertor (transducer) of an electronically-driven ultrasonic device or system.  Mechanical generators also have been made.

[H]

Hertz (Hz)  -  a unit of frequency equivalent to the now-denigrated "cycle-per-second" (cps).  One Hertz (1 Hz) equals 1 cps.

HIFU  -  acronym for High Intensity Focused Ultrasound, a minimally-invasive medical technique used for tumor ablation and destruction.

Horn (syn. Tool)  -  usually an amplifying element, that includes, or is fitted with, a tip in an ultrasonic probe.

[I]

Immersible Transducer  -  a radiating device sealed in a housing (usually stainless steel), the forward or front surface of which is the radiating surface, and which can be submerged under the surface of a liquid bath to energize the liquid to produce cavitation.  An immersible transducer placed in a still tank turns that tank into an ultrasonic cleaner.  The immersible transducer is, in effect, a standard tank everted (turned inside out) with the radiating surface on the outside and the transducers on the inside.

Input  -  in terms of direction in an ultrasonic system, that direction toward the power source and away from the process.

Intensity  -  in terms of acoustic output, the term "High Intensity" is favored herein in lieu of "High Power" because high intensity is required for cavitation.  A 1/16" (1.6mm) diameter tip on a probe does not require much power at all to radiate at high intensity whereas a large sonar array may soak up enormous power while radiating at very low intensity.

[J]

Jet  -  syn. Liquid Jet, q.v.

[K]

Kilohertz (KHz)  -  a unit of frequency equivalent to one thousand "cycles-per-second" (cps).  One Kilohertz (1 KHz) equals 1,000 cps.

[L]

LIFU  -  acronym for Low Intensity Focused Ultrasound, a minimally-invasive medical technique used for tumor ablation and destruction.

Liquid Jet  -  a jet of liquid, moving at extreme velocity against a surface, which results from the assymetrical implosion of a cavitation bubble in close proximity to that surface.

[M]

Magnetostrictive  -  having to do with systems driven by the effect of certain metals, especially nickel, and certain other materials such as ytterbium compounds, which expand and contract in an alternating magnetic field.

Megahertz (MHz)  -  a unit of frequency equivalent to one million "cycles-per-second" (cps).  One Megahertz (1 MHz) equals 1,000,000 cps.

MICROTIP™ -  a trade name (now generic) for needle-shaped horns (or attachments to horns) which enable the radiating face to fit inside narrow test tubes, vials, and other small vessels.   (05 Mar 10)

[N] - {no "N" definitions, yet.}

[O]

Output  -  in terms of direction in an ultrasonic system, that direction away from the power source and toward the process.

Output Surface  -  syn. Radiating Surface, q.v.

[P]

Permeability  -  while not a term of ultrasonics, per se, permeability of membranes (including skin) can be altered by application of ultrasonic energy (see What's New?).

Piezoelectric  -  having to do with systems driven by the effect of certain crystals, such as lead-zirconate-titanate, and other materials, which expand and contract in an alternating (charged) electrical field.

Pocketing  -  a situation where gases trapped in voids under or on the surface of objects prevent cleaning action (term coined by Berliner  -  see text).   (05 Mar 10)

Power  -  see Intensity.

Power Supply  -  syn. Generator, q.v.

Probe  -  in ultrasonics, term commonly used to describe the convertor-horn-tip system which accepts power from a generator and does work [not to be confused with sensing elements used in non-destructive testing and measuring].

Propulsive Force  the force generated in a medium when acoustic energy leaves a radiating face.

[Q] - {no "Q" definitions, yet.}

[R]

Radar (Radio Detecting and Ranging)  -  an electronic means of determining distance (not an acoustic means).

Radiating Face - syn. Radiating Surface, q.v.

Radiating Surface (syn. Radiating Face)  -  that surface in a stack or convertor or on a diaphragm farthest away from the transducer which radiates acoustic energy (often the tank bottom or the horn tip).

Radiation  -  the propagation of energy; for the purposes of this text primarily restricted to the propagation of acoustic energy through a medium [as opposed to electromgnetic radiation (such as light, electricity, radio waves, etc.), which does not require a medium].  Although primarily propagated by the vibration of a solid surface, acoustic radiation can also be generated by other means (see text).   (05 Mar 10)

  NOTE: The term "radiation", when applied to acoustics, in which it refers
    to a purely mechanical phenomenon, has no connotation whatsoever
    to do with nuclear radiation, an electromagnetic phenomenon.

Radiator  -  syn. Radiating Surface, q.v.

Rear (syn. Back)  -  arbitrary convention (by Berliner et al.) for direction in a transducer, stack or convertor from the longitudinal center or crystals and away from the radiating face or tip.

Rear Driver  -  that set of elements (when so fitted) behind the transducing elements in a stack which dynamically counter-balances the front driver.

Resonant Body  -  any physical object which can resonate when struck (ring like a bell).

ROSETT™ Cooling Cell  -  a specially-shaped processing vessel, usually glass, with semi-circular tubulations to facilitate turbulent, recirculating flow (originally developed by Dr. Theodore Rosett).

[S]

Sealed Atmosphere Treatment Chamber  -  a high-pressure processing vessel with inlet and outlet tubes.

Sonar (Sound Navigation and Ranging)  -  an underwater acoustic means of determining distance.

Sonic  -  having to do with the velocity (speed) of sound (specifically as opposed to ultrasonic, q.v.).  Some cleaning devices are labelled as "SONIC" to possibly imply that they operate ultrasonically, whereas in fact they merely vibrate parts without generating cavitation.

Sonicate  -  to process materials with ultrasonics, specifically to change materials chemically and physically.  Not generally used for cleaning or joining (term coined by Berliner).

Sonify  -  syn. Sonicate, q.v.

Sonochemistry  -  driving and accelerating chemical reactions through application of ultrasonic energy.

Sonolysis  -  disruption of biological cells through application of ultrasonic energy.

Sonotrode  -  European term for Ultrasonic Processing Probe.

Stack  -  the most basic combination of transducer and amplifying elements together forming a resonant body to be attached to (or including) a radiating surface or horn.  In some magnetostrictive transducers, the stack is a set of nickel laminations (shims) brazed at the ends and somemes at the midpoint and fastened to the front driver or horn.

Still Tank  -  an ultrasonic tank which has not (yet) been activated to produce cavitation (cf. Active Tank, terms coined by Berliner) or a tank which is not fitted with ultrasonic transducers.

Subsonic  -  having to do with velocities below the speed of sound (specifically as opposed to ultrasonic, q.v.).

Supersonic  -  having to do with velocities above the speed of sound (specifically as opposed to ultrasonic, q.v.).

[T]

Tank  -   syn. Bath, q.v., or any container holding a body of liquid, especially an ultrasonically-activated container or tank.

Tip  -  the radiating surface of a horn or other final element of a stack or convertor which radiates acoustic energy outwards to do work (such as processing or joining).  Tips may be integral with the final output element or may be removable.

Tool  -  syn. Horn, q.v.  Tool is more commonly applied in welding and joining and like operations whereas Horn is more commonly applied in processing.

Transsonic  -  having to do with velocities around the speed of sound (specifically as opposed to ultrasonic, q.v.).

[U]

Ultrasonic  -  having to do with frequencies of sound above normal human hearing, generally accepted to be at 20KHz to 2MHZ and above, but also extended down to the 5KHz to 20KHz range in certain processing applications (cf subsonic, supersonic, or transsonic, which have to do with the speed of sound).

Ultrasonics  -  the application of ultrasonic energy to do work (specifically as opposed to subsonic, supersonic, or transsonic, q.v.).

Ultrasonic Cleaning  -  changing the surface of materials by the application of ultrasonics, thereby removing contaminants; for the purposes of this text, included in Ultrasonics Processing.

Ultrasonic Joining  -  a term of art covering ultrasonic welding, bonding, fusing, soldering, staking, and like applications.

Ultrasonic Liquid Processing  -  subset of Ultrasonic Processing in which work is done in a liquid medium; some processing, such as drying and levitation, can be accomplished in air or other gaseous media.

Ultrasonic Processing  -  changing materials (including the surface of materials) by the application of ultrasonics; term coined (by Berliner) to include various forms of application of ultrasonics such as cell disruption and homogenization and the like, and to differentiate them from joining, and other applications.  However, for the purposes of this text, includes Ultrasonics Cleaning.

Ultrasonic Processor  -  a complete device, normally consisting of a Generator and a Convertor, plus a Horn and accessories, which accepts a form of energy, usually electrical, and transforms it into ultrasonic energy to change materials.

["V", "W", "X", "Y", and "Z"] - {no "V", "W", "X", "Y", or "Z" definitions, yet.}

{Please advise of terms for consideration.}

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For more information, please contact S. Berliner, III.

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You may wish to visit the main Ultrasonics page, et seq., as well as the Ultrasonics Cleaning page {also in process}.

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To contact S. Berliner, III, please click here.

       
To tour the Ultrasonics pages in sequence, the arrows take you from the main Ultrasonics Page (with full index) to Pages A, 1, 1A, 2, 3, 4, 4A, 5, 6, and 7, this Glossary Page, Cleaning Page, and Bibliography Pages 1, 2, and 3 (see Index).

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