Ultrasonic Bibliography Page 3 - Selected Articles.
CALL FOR CONTRIBUTIONS: I am writing a book on "High-Intensity Ultrasonic Technology and Applications", on the practical application of power (high intensity) ultrasonics, the use of ultrasonic energy to change materials. Contributions are welcome (see below).
THE CAVITATION BUBBLE
[image from University of Washington, Applied Physics Laboratory (Lawrence Crum, Ph.D.)
- bubble diameter approximately 1mm]
ULTRASONICS
Threshold of Cavitation
.
The word "threshold" is used in several ways in regard to
cavitation; we refer here to the most critical of these, that which affects the
initiation, the onset, of cavitation. As noted
earlier, "Cavitation requires some discontinuity in the liquid, such as gas
bubbles or dust motes, about which the bubble forms. A theoretically
pure liquid would require impractically high power levels to initiate cavitation."
This "initiator" could also be a sharp edge or projection on the radiating
surface or even on an adjacent surface. Normally, this is only of
theoretical interest to one processing liquids with ultrasonics; however, with
the wider availablity of probes and tanks with variable output power, especially
those that are infinitely adjustable from no, or virtually no, amplitude, this now
becomes a matter of practical importance. On such machines, it is
necessary to observe (visually or by the sizzling sound) the point at which full
bubbling occurs; one must bring the amplitude up above that point, the
threshold of cavitation, in order to
process or clean. Once beyond that point, the amplitude can be
reduced somewhat without dropping out of cavitation.
The initiation of cavitation requires a situation where adjacent molecules of
liquid are less tightly bonded bcause of the presence of a discontinuity (bubble,
speck, point, or edge). The threshold of cavitation is highly variable,
being affected by the degree to which the liquid may have been previously
degassed, by the temperature, pressure, and viscosity of the liquid, the types
of discontinuities extant, and other parameters. It is not the provenance
of this short work to discuss the physics of the phenomenon, only to being it to
your attention.
The ability of a transducer and generator (power supply) to operate at such
low energy levels is a function of their design and the manufacturer of the
equipment should be consulted before running the equipment at low output
power levels unless such use is specifically allowed by the instructions given.
Dissolution
Dissolution (of samples, NOT of personalities!), as of tablets
for quality control in pharmaceutical work, includes or overlaps many other ultrasonic
operations. Among these are disruption, homogenization, emulsification, and
dispersion. Dissolution can be used to enhance examination of samples in
many other quality control areas, notably to dissolve coupons of polymers in solvents.
The great advantage to using ultrasonics is that the dissolution progresses far faster
than by other means, such as by stirring, shaking or otherwise agitating, by heating,
or by washing. In coupon dissolution of plastic films, the author observed
results ten or more times faster than previously tried methods, even as much as
obtaining times in minutes that had taken the same number in hours.
There are three most common methods to dissolve tablets, coupons, or other samples.
In all cases, care must be taken to avoid igniting or inhaling solvents.
Ultrasonic Cleaners - The simplest and often cheapest method is to use a
laboratory ultrasonic cleaner (bath). The sample could be placed directly in the
tank but then the entire contebts of the tank must be removed and replaced for each
sample; instead, each sample can be placed in a beaker or a well of a multi-well tray
and then floated or held in the bath such that energy passes through the bottom of
the beaker or well into the sample. The drawback is that intensity is generally
fairly low and repeatability is poor.
Ultrasonic Cup Horn - A more intense variation of the bath system is to use a
Cup Horn, a bath driven by the convertor of a
probe-type processor. Intensity is fairly high and repeatability good but
requires careful attention to physical placemnet of sample vessel.
Ultrasonic Processor - The most intense method, in which an active probe tip
is inserted into the sample vessel. Intensity is extremely high and repeatabilioty
excellent but the tip must be cleaned between samples (it can clean itself).
Among the many parameter variables to be considered are the vessel
(thickness, configuration, material, and quality), liquid condition (surfactant
coupler, temperature, depth, degassing, impurities, etc.); sample conditions
(configuration and condition in vessel, particle size, density, solubility, etc.),
cleaner bath (output frequency, amplitude, regulation, power capability,
temperature variations, line voltage and frequency fluctuations, etc.); and so
on and on.
{to be expanded upon}
Foaming and Aerosoling (moved to
page 4a on 10 Oct 04)
Ultrasonic Propulsion (Propulsive Force) - Moving Material.
(moved to
page 4a on 10 Oct 04)
Ultrasonic Fountains - Atomization,
Nebulization, Humidification,
Misting, Particle Creation and Sizing
(moved to
page 4a on 10 Oct 04)
Ultrasonics and Nuclear Fusion
Back in 1989, Dr. Stanley Pons of the University of Utah and Professor
Martin Fleischman of Southampton University in the UK claimed they
found evidence of cold fusion at room temperature in a test tube; the
general derison in the scientific community was loud and overwhelming
(and probably unwarranted), but I felt they were on to something and
that the incredible pressures and temperatures in the collapsing
cavitation bubble might well induce fusion - not "cold", but still
fusion, and offered to work with them to prove concept. Nothing
came of that, but, more recently, Drs. Rusi Taleyarkhan, a senior
scientist in Oak Ridge National Laboratory's Engineering Science and
Technology Division, and Richard T. Lahey Jr., the Edward Hood
Professor of Engineering at Rensselaer Polytechnic Institute, et al,
issued a press release (dated 04 Mar 2002) indicating that they may
have done just that.
It will be interesting to follow the progress of this investigation.
However, at the 37th Annual Technical Symposium of the Ultrasonic
Industry Association, on 07 Apr 2008, no less than Ken Suslick, who
certainly knows his cavitation bubble, said he'd found no evidence of
any fusion products. Hmmm.
The primary references are (from Science's Website, "The report by R. P. Taleyarkhan et al. of observations of tritium decay and neutron emissions associated with the collapse of tiny bubbles in deuterated acetone and the possibility that those observations may have arisen from fusion reactions within the imploding bubbles"; the research article by Taleyarkhan et al., and three associated commentaries, a perspective by F. D. Becchetti describing the research and its significance; a news article by Charles Seife on some of the controversy stoked by the paper, and an editorial by Science's Editor in Chief, Donald Kennedy, on why Science decided that 'publication is the best option'.":
-
R. P. Taleyarkhan et al., Evidence for Nuclear Emissions During Acoustic Cavitation, Science 295, 1868 (2002) (in Research Articles)
F. Becchetti, Evidence for Nuclear Reactions in Imploding Bubbles, Science 295, 1850 (2002) (in Perspectives)
C. Seife, "Bubble Fusion" Paper Generates a Tempest in a Beaker, Science 295, 1808 (2002) (in News of the Week)
D. Kennedy, To Publish or Not to Publish, Science 295, 1793 (2002) (in Editorials)
The term "Bubble Fusion" seems to have caught on; it does help distance this process from "cold fusion". How much of this hooraw is justified and how much is a bitter legacy from 1989 is an interesting question, but, clearly, the scientific community was (or feels it was) burned and is exercising extreme caution. Unfortunately, any progress toward cold fusion is clouded in a morass of psychic and metaphysical nonsense and it is earnestly hoped that the newer work does not become so tainted.
I should be pleased to assist in this matter but probably do not have the credentials to be taken seriously (the fallout of not having taken advanced degrees).
Well, at long last comes partial vindication of Pons and Fleishman,
and of my faith in the possibility; at the American Chemical Society's
237th National Meeting, a paper the topic was presented during a
four-day symposium, "New Energy Technology," March 22-25, in
conjunction with the 20th anniversary of the first description of cold
fusion, co-authored by analytical chemist Pamela Mosier-Boss, Ph.D.,
of the U.S. Navy's Space and Naval Warfare Systems Center (SPAWAR) in
San Diego, Calif. The paper reported "compelling new scientific
evidence for the existence of low-energy nuclear reactions (LENR)",
the process once called "cold fusion"; response was instantaneous and
not all positive - here we go again! Stay tuned.
(22 Apr 09)
Boosters
(Booster Horns)
Boosters (booster horns) are additional stages of mechanical amplification inserted
between the front driver of a convertor (see Equipment
and Terminology on main page) and the output horn:
(17 Oct 2003 image by and © 2003 S. Berliner, III - all rights reserved)
The standard horn serves as such for a standard MICROTIP, as does the Upper
Section for the Stepped MICROTIP.
Boosters are available at various positive and negative gain factors, commonly from
3:1 to 0.5:1. A booster is, in effect, simply another horn inserted ahead of a
regular horn to give the output tip (radiating face) greater amplitude:
(17 Oct 2003 image by and © 2003 S. Berliner, III - all rights reserved)
A positive-gain booster would not normally be used with a high-gain horn because the
amplitude of the latter might well exceed its design limitations, causing the output
horn to over-extend and fatigue and crack at the nodal point. Rather, a
booster would be used with a low-gain or negative-gain horn (such as used in the
Cup Horn) to give higher amplitude on a larger diameter radiating face:
(17 Oct 2003 image by and © 2003 S. Berliner, III - all rights reserved)
One exception might be when the tip of a high-gain horn is working against a very
high static head. However, do NOT use positive-gain booster horns
without first consulting with the manufacturer of the ouput horn!
Quick Links to Major Ultrasonic Probe Manufacturers
For your convenience (and their benefit), I list here three of the top
manufacturers of ultrasonic probes for changing materials (NOT sensing
probes); this list is neither exclusive nor exhaustive but represents
firms with which I have dealt closely and which I can wholeheartedly
recommend:
Qsonica, LLC.@
(13 Nov 09)
http://www.sonicator.com/
53 Church Hill Road
Newtown, Connecticut 06470
Phone: 203-426-0101
FAX: 203-426-7026
e-mail: info@sonicator.com
SONICATOR®/MICROSONTM: http://www.sonicator.com/site/index.aspx
@ - The Misonix SONICATOR line of ultrasonic liquid processors is now
manufactured by Qsonica, LLC.
(13 Nov 09)
Sonics & Materials, Inc.
http://www.sonicsandmaterials.com/
53 Church Hill Road
Newtown, Connecticut 06470
Phone: 203-270-4600, 800-745-1105
FAX: 203-270-4610
e-mail: info@sonicsandmaterials.com
VIBRA-CELL: http://www.sonicsandmaterials.com/home.html
Branson Ultrasonics Corporation
http://www.bransonultrasonics.com/
Precision Processing Division
http://www.bransoncleaning.com/
41 Eagle Road
Danbury, Connecticut 06813-1961
Phone: 203-796-0400
FAX: 203-796-9813
e-mail: info@bransoncleaning.com
SONIFIERTM: http://www.bransoncleaning.com/Sonifier/SonifierProducts.htm
Miniature probe machines (even battery-operated) are available from:
Sonaer Inc.
http://www.sonozap.com/
145 Rome Street
Farmingdale, New York 11735
Phone: 631-756-4780
FAX: 631-756-4775
e-mail: sonaer@fcc.net
SONOZAP Ultrasonic Processors, Atomizer Nozzles, and Nebulizers
http://www.sonozap.com/Ultrasonic_Processors.html
In addition to these processors, similar equipment is used for ULTRASONIC
DRILLING and MILLING and the manufacturer of such
equipment as a standard product line is:
Sonic-Mill
http://www.ceramics.com/sonic/
7500 Bluewater Road, NW
Albuquerque, New Mexico 87121-1962
Phone: 505-839-3535
FAX: 505-839--3525
e-mail: sonics@ceramics.com
[There is no guarantee made whatsoever that these listings are
correct, complete, or current.]
(Tradenames are noted solely for information and remain the
intellectual property of the manufacturer.)
Please note that a far-more detailed explanation of ultrasonic processing, as
well as other technical literature, is available at no charge to consultation
clients. However, as what I believe to be a public service, I shall be
adding more of my monographs on ultrasonics on this site; watch for them in
the index.
You may wish to visit the main ULTRASONICS page, et seq., with more on ultrasonics, as well as the Ultrasonics Cleaning page {in process} and the Ultrasonics Glossary page {also in process}.
Those persons interested in SONOCHEMISTRY might wish to look at the sonochemistry pages of:
Prof. Kenneth S. Suslick of the University of Illinois at Urbana-Champaign, and
Dr. Takahide Kimura at Shiga University in Japan.
THUMBS UP!
THUMBS UP! - Support your local police, fire, and emergency personnel!
S. Berliner, III
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, and 4, Glossary Page, Cleaning Page, and Bibliography Pages 1, 2, 3, and 4 (see Index, above).
© Copyright S. Berliner, III -
1999, 2001, 2002, 2003, 2004, 2005, 2008,
2009
- All rights reserved.
Return to Top of Page
times since the counter was installed.
