Edited by Henry Wallace, Director of Research

REMOVAL OF CARBON DIOXIDE FROM SOLUTION

Sometimes it is desired to remove a dissolved gas from a liquid solution. This is called "degassing", and is a natural consequence of high intensity ultrasound in the solution. Cavitation has been called "cold boiling" because, as the dissolved gases are being released by ultrasound, they can be seen to rise to the surface of the solution, much as if the solution had been brought to its boiling point.

Recently some experiments were conducted on the removal of carbon dioxide from solution, using one of our Sonochemist systems. This was an unusual situation for us, in that we were not directly involved in the experiment, but were asked to comment on the results obtained, with no "contract" and no remuneration. Thus we feel no security obligation, and are free to speak openly about the comments we made.

Apparently, during the first one minute of ultrasonic treatment, about 50% of the carbon dioxide was removed. The experiment continued to run for several more minutes, with no additional release of gas. When I was asked to comment on this, I turned to our trusty database, and found an article: H Harada, "Sonochemical reduction of carbon dioxide", ULTRASONICS SONOCHEMISTRY, vol. 5, Issue 2, 1998, p. 73-77. Dr. Harada is at Iwaki Meisei University, Faculty of Physical Science & Engineering, Department of Chemistry, Hino, Tokyo 1918506, Japan.

Apparently Dr. Harada had a similar result to the one I was asked to comment on, although it took his equipment one hour to do what our Sonochemist did in one minute. He wrote, "During one hour of sonication, the amount of CO2 decreased to about half …". His equipment was likely a 20 kHz unit, and this probably explains the higher rate using the 660 kHz Sonochemist.

My explanation of why both reactions appeared to stop after an initial 50% removal is as follows: [ Please, any Chemist who either agrees or disagrees, contact me at henry@ultrasonic-energy.com ] It is my understanding that when carbon dioxide is added to water, most of it becomes hydrated molecules of CO2 but some of it is present as a weak, unstable acid, carbonic acid, H2CO3. I suspect that these two species exist in equilibrium with one another. I suspect the initial 50% removal is due to removal of the more "gas-like" hydrated molecules of CO2. This would suggest that these two species each represent about 50% of the carbon dioxide in water at any time, once equilibrium is established.

To remove another 50% of the remaining carbon dioxide ( for a total removal of 75% ) would require that this equilibrium between the two species be reestablished. How this might be best accomplished, I do not know. I suspect that storage of the intermediate solution for some as yet undetermined time would do it, although this might not be the most efficient approach.

To any of you who would like to commercially apply this ultrasonic method of carbon dioxide removal, I have done some quick calculations. I have found that the first 50% can be removed from about 100 liters of solution with application of about one kilowatt-hour (kWh) of electrical input power from the electrical Mains. If my supposition that another 50% can be removed after a storage time is correct, then 75% of the carbon dioxide can be removed from about 50 liters of solution per kWh of electrical power. These calculations consider that our Pilotstation system is used.

This ultrasonic process should be fairly maintenance free. Other gas-removal technologies (vacuum, for instance ) might have higher maintenance costs. But vacuum pumps, if used for carbon dioxide removal will also remove a lot of water from the solution . This water will tend to accumulate in the vacuum pump. If "oil pumps", such as are used in refrigeration are employed, the oil will have to be changed regularly, as the oil will become cloudy with water.

"MICRO SYNTHESIS" and "REMOTE MIXING"

Out of stupidity, we have, for years, ignored an important ultrasonic application in micro synthesis. And lately, have received several requests for information on remote mixing. These two subjects are somewhat related, in that both applications usually involve very small amounts of solution, in the range of a few milliliters or even microliters. First, some background:

An important emerging variable in sonochemistry is watts/cc. Authors have begun to understand that the ultrasonic power, in watts, applied to the treatment volume, in cubic centimeters, or watts/cc, effects reaction rates in a linear manner. That is, given two experiments in which all else is equal ( ultrasonic frequency, temperature, chemistry involved, etc. ) the sonochemical reaction rates will be twice as fast in the experiment in which the watts/cc is twice as great. For instance, our Pilotstation "sets the curve" for watts/cc in large volumes, at about 4,000 watts per 6,000 cc, for a watts/cc of about 2/3. [One Pilotstation vessel, still as yet on our drawing board, will raise this to ¾ watts/cc.] However, at these large energy-densities, heating of the solution becomes a major issue, and this is why "chillers" and "heat-exchangers" are recommended for use with the Pilotstation line. One watt for one second contains 0.239 calories, and will heat one cc of water 0.239 degrees C per second. Our standard Pilotstation ( 4,000 watts / 6,000 cc ) will raise the water temperature 0.239 times 2/3 degrees per second ( 0.159 deg/sec ) or 9.56 degrees per minute, without chillers and heat exchangers.

Micro Volumes

Now consider that we have a small reactor vessel, containing 0.250 cc of solution ( 250 microliters ), and that this vessel has a "footprint" or base area of one square centimeter. We can easily deliver ten watts/square centimeter of ultrasound into this vessel. Thus, the watts/cc rises to 40 ! Of course, the ultrasonic heat delivered also rises dramatically, to 9.56 degrees per second, without chilling. [ Because this small vessel has a comparatively large surface/volume ratio, chilling might be accomplished simply by chilling the sound-conducting fluid, degassed water, surrounding the vessel.]

Because this watts/cc is so large, treatment times and temperature shifts will likely be reduced. In the Hua-Hoffmann article below ( see "Visit to Caltech" ) watts/cc at 513 kHz was about 0.065. With the small vessel mentioned above, with a watts/cc of 40, we would expect sonochemical rates more than six hundred times the rates in that article. Thus the treatment times, during which the temperature rises, would be expected to be considerably reduced. This is why we have become interested in micro synthesis. This is why we will entertain any opportunity to provide equipment to the field of ultrasonically-stimulated micro synthesis. This SHOULD become a major growth-direction for sonochemistry.

Remote Mixing

Closely related to the above is the field of "remote mixing". Often our customers ask whether they need to mix the chemicals in their reactor vessels, and we usually tell them that this is not important. Because the transducer acts like a "pump", the chemicals in our standard reactor vessels naturally undergo extreme mixing. In the Yadda-Yadda-Yadda section of this Site you will see pictures of the various "plumes" which high-intensity ultrasonic transducers "throw". Imagine what happens when this plume is contained in a small reactor vessel, and you will understand why no more mixing is required.

Because many materials are fairly "transparent" to water-borne ultrasound, this "pumping" action of high-intensity ultrasound can often be "exported" into a separate container or reactor vessel. Most plastics are fairly transparent to water-borne ultrasound, although some are more acoustically "lossy" than others and will absorb some of the sound as heat. It is possible that the heat absorbed by the separate container can damage the container, and this must be tested.

But generally, remote mixing by ultrasound presents some unique benefits. Often, for instance, the very small reactor vessels of volume only a few cc cannot accommodate more conventional mixing methods: there just is not room. In such cases, and where the ultrasound used for mixing does not produce unwanted side-effects such as unwanted sonochemistry or excessive temperature increases, it can be a real help. Testing is required to determine whether these unwanted effects prove detrimental to any particular process.  

FEATURED ARTICLE:

Visit to Caltech

Development of our UES4000C Pilotstation recently took us to the W. M. Keck Laboratories at CALTECH in Pasadena, California. Here we met Doctors Michael Hoffmann, A. J. Colussi, Hugo Destaillats, and graduate student Tim Lesko. Dr. Destaillats "benchmarked" our Pilotstation. He found that it accomplished 60% reduction in 13 liters of Methyl Orange dye solution in under 25 minutes! These are the kind of applications the UES4000C was designed for : large quantities of commercially important solutions.

While at CALTECH we were given a copy of a paper published in 1997 by Dr. Inez Hua of their group: I. Hua and M. Hoffmann, Optimization of Ultrasonic Irradiation as an Advanced Oxidation Technology, Environmental Science & Technology, Vol. 31, No. 8, 1997. This paper shows the beneficial effects of the higher ( submegahertz ) ultrasonic frequencies for sonochemistry and remediation chemistry. It also reveals the enhancements which result from the use of the noble gases ( helium, argon, and krypton ) as sparge gases in sonochemical solutions. These monatomic gases were shown to increase in effectiveness with increasing atomic weight. The solubility of these gases in water was also shown to increase with increasing atomic weight.

The following speculations on these results were not included in this paper.

We speculate that the increasing sparge-gas effectiveness with increasing solubility might be almost entirely due to the availability of these gases to the cavitating bubbles. Figure 1 shows the average separation between the molecules of these gases in a pure water matrix. Figure 2 shows the size of the cavitating bubble along with the size of a sphere of water which must be emptied in order to fill the cavitating bubble with the various noble gases. In these Figures we have included the noble gas xenon, the best sparge gas of those shown, but one which is quite expensive and is seldom used.

Figure 1 attempts to show graphically how these various sparge gases would appear microscopically, if perfectly ordered in a perfect water matrix. Note that a single atom of sparge is shown to occupy a small cube of water with sides N water molecules in length. The water molecules are separated by a distance of 3.1 Angstroms ( ten to the minus ten meters ), so that a helium atom, for instance, would occupy a small cube of water with 116 water molecules on each edge. Each edge, for helium, would be about 360 Angstroms in length, and the volume of the small cube of water would be about 46.7 nano-nano cubic centimeters ( 46.7 times ten to the minus 18 cc ).

Figure 2 attempts to show the relative sizes of the cavitation bubble, as compared with the sphere of water which must be emptied of sparge in order to fill the cavitation bubble. Thus, in order to fill the cavitation bubble ( shown In red ) all the helium in the light blue sphere of water would have to be "scavenged" and placed within the cavitation bubble. Likewise, in order to fill the cavitation bubble with xenon, all the gas within the dark blue sphere of water would have to be placed within the red sphere.

Figure 2 is but a "snapshot" of the cavitation bubble, taken at a time in the acoustic cycle when the bubble size is at it's "mean diameter". The red sphere is known to expand to several times this size, before being driven to even smaller size by the action of the acoustic excitation. It is thus comprehensible that the bubble wall of the red sphere could "sweep" out to include the nearby sparge spheres ( xenon, krypton, or argon ). But it is less comprehensible that it's bubble wall could ever sweep out far enough to include the helium sphere.

It is interesting that sparge gas effectiveness increases exactly with decreasing radius of the spheres shown in Figure 1. The most effective noble sparge gas, xenon ( shown in the blue sphere ), is also the most available to the cavitating bubble, shown as the red sphere. This is because the xenon requires the smallest "swept radius" of the gases shown. Krypton exhibits the next smallest radius, is next most effective as a sparge, and so on.

The mechanism by which the cavitating bubble avails itself of the sparge gases is not very well understood. Apparently it has to do with the nonlinear process of rectified diffusion. The bubble-wall of the cavitating bubble has been shown to travel at supersonic speeds, as it sweeps out from it's "mean diameter" during the negative half of the acoustic excitation cycle. The atoms of noble sparge gas are probably not very well "locked" or "frozen" into the water matrix, because they are monatomic and exhibit little polar attraction to the water molecules. The noble sparge atoms are also very dense, compared to the water molecules. Could it be that these dense, loosely held noble atoms are simply "left behind" by the bubble-wall as it sweeps out at supersonic speeds? This would tend to fill the cavitating bubble with the sparge atoms, if true.

If this is true, it might be found that soluble salts of dense metals, added to a solution, might also behave as effective "liquid sparge agents".

Another interesting thing about Figure 2: it is independent of frequency. Only the "scale" of Figure 2 changes with acoustic excitation frequency. This "scale" is governed by the R term of equation (8) in the above-referenced paper, and decreases linearly with increasing acoustic frequency . This fact speaks to the average velocity which the sparge molecules would have to exhibit, in order to move from their static positions in their respective water spheres and into the cavitation bubble. In fact, these average velocities are not a function of frequency, but depend only on the particular sparge gas. This is because decreasing frequency expands the scale of Figure 2, meaning that the average sparge molecule would have to travel a greater distance to arrive in the cavitation bubble. But, offsetting this trend, is the fact that the lower frequency allows greater time to accomplish this increased distance, if the transit is to happen in one-half of an acoustic cycle.

The average velocities required for the sparge gases to rearrange themselves into the cavitation bubble, during one-half of an acoustic cycle, are:

Xenon	5.78	meters/sec
Krypton	8.79	meters/sec
Argon	12.0	meters/sec
Helium	54.9	meters/sec

These are considered to be very low, easily obtainable velocities. The following table compares the above drift velocities to the acoustic wave velocities in the various gases (wave velocity from tabular data at zero degrees C, one atmosphere )

Sparge	Velocity drift	Wave velocity	Percent
	meters/sec	meters/sec
Helium	54.9	965	5.69
Argon	12.0	319	3.76
Krypton	8.79	228*	3.86
Xenon	5.78	176*	3.28

* Estimate, based on atomic weight and tabular data for argon.
 
 

Nearly Complete Sonolysis

Sonolysis is the reduction of molecular size by ultrasound. Often, it is only necessary to reduce molecular size by a small amount, to accomplish the intended effect. An example would be when radioactive metals have become attached to polymers. In such cases, it is sometimes sufficient to "snip" off the radioactive material, then to dispose of the radioactive wastes separately from the rest of the material.

But it is interesting to see an article reporting an experiment in which, by ultrasound alone, sonolysis was allowed to go almost to completion. Such experiments were reported by K. Vinodgopal, J. Peller, O. Makogon, and P. V. Kamat, in "Ultrasonic mineralization of a reactive textile azo dye, Remazol black B", published in WATER RESEARCH, Vol. 32, Issue 12, P.3646-3650, PERGAMON-ELSEVIER SCIENCE LTD, Oxford.

The authors used equipment from Ultrasonic Energy Systems. According to the Abstract,

"The degradation of a reactive black dye in oxygen saturated aqueous solution has been investigated using a high frequency ultrasonic generator. The (OH)-O-. radical initiated oxidative degradation of the dye results in 65% mineralization as measured by the decrease in the total organic content. Ion chromatography indicates that the only remaining components are oxalate, sulfate and nitrate ions."

Not only is unaided ultrasound capable of reducing complex molecules to more benign compounds, but it is also capable of low-temperature "cracking" of highly complex molecules. Examples are when extremely valuable drugs are discovered imbedded in naturally occurring molecules, such as those from the world's rain forests.

Lejbkowicz,F., and Salzberg,S. ,"Distinct sensitivity of normal and malignant cells to ultrasound in vitro", ENVIRONMENTAL HEALTH PERSPECTIVES, vol. 105 Supplement 6, December 1997, Published by US DEPARTMENT OF HEALTH AND HUMAN SERVICES PUBLIC HEALTH SERVICE, RESEARCH TRIANGLE PARK, p. 1575-1578

Is High Intensity Ultrasound a MAGIC BULLET against Cancer?

DIAGNOSTIC ultrasound is what doctors use to "look inside" people, and uses levels of sound which are closely controlled so as not to cause damage. THERAPEUTIC ultrasound, on the other hand, is higher intensity sound which is actually intended to change the cells inside one's body. The author of the above paper considers Therapeutic Ultrasound to affect cancer cells in a specific way, while leaving normal cells alone. According to his Abstract,

" The effect of ultrasonic irradiation on the viability of human normal (foreskin fibroblast and amniotic fluid epithelial) and tumor (breast carcinoma, melanoma, and lung carcinoma) cell lines was studied. Cells were subjected to ultrasonic irradiation with a frequency of 20 kHz and an intensity of 0.33 W/cm(2) for variable periods of time. Several parameters were tested to determine the effects of ultrasonic irradiation on cell viability and cellular function. Normal cells were relatively resistant to ultrasonic irradiation, whereas malignant cells were much more sensitive. Maximum damage occurred 4 min after exposure of the malignant cells to irradiation. Cellular DNA and protein synthesis were significantly affected as a function of time of irradiation and cloning efficiency of malignant cells exposed to irradiation was greatly reduced. To generalize the consistency of the ultrasonic effect, studies on additional normal and malignant human cells of distinct origin are under way to test their sensitivity to ultrasonic irradiation. Thus, the applicability of ultrasonic irradiation as an antitumor agent may be important in the development of a new methodology in the treatment of cancer."

Therapeutic ultrasound uses highly focused, intense ultrasound to actually destroy tissue. Because this technique requires no surgery, and the "lesions" produced by the ultrasound can be tightly controlled and buried in unaffected tissue, it is being widely researched in Europe and in Japan( 2, 5, 7, 9, 10,11, 12,16 ). The entirely acceptable concern of many physicians is that surrounding tissue, which may be ablated but not rendered harmless, might spread from the zone of destruction and carry the malaise with it (3, 14).

With a few exceptions ( 3, 6, 13, 14, 17, 18, 19 ), and probably for good reason, therapeutic ultrasound does not appear to be widely supported by the American medical establishment. For instance, the Journal of Ultrasound in Medicine, published by the American Institute of Ultrasound in Medicine of Laurel, Maryland, refuses to publish articles on therapeutic ultrasound. For publication, American authors must submit to one of the several European journals, which are more than happy to publish said articles. These European journals accept the premise that therapeutic ultrasound might indeed spread the malaise, and often publish articles on experimental ultrasonic therapies, and whether viable ( and thus dangerous ) tissue appeared to be spread by the therapy.

Ultrasonic attack on cancer can proceed along two distinct paths. First, the "direct approach" is to rely on the direct destruction of cancer cells by ultrasound (3). The second approach is to utilize ultrasound to release drugs but only in the vicinity of the tumor and thus prevent systemic exposure to these strong chemicals ( 2, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 16, 17, 18, 19 ).

Regardless of which of the above approaches is taken will likely depend on the location, size, and type of cancer encountered. But the point is, The Future Platform for Cancer Diagnosis and Treatment will likely be ultrasonic in nature. A good deal of the "basic" work has been done. It is now time to fund ultrasonics, in both its Diagnostic role and in its Therapeutic role, with an eye to combining the two roles into single, inexpensive, small units for wide distribution.

References

1) HC Wallace, R Gupta, "Sonochemical reactions at 640 kHz using an efficient reactor. Oxidation of potassium iodide", ULTRASONICS SONOCHEMISTRY, vol. 4, no. 4, Oct. 1997, ELSEVIER SCIENCE BV, AMSTERDAM, p.289-293.

2) WG Pitt, "Ultrasonic activated drug delivery from pluronic P-105 micelles", CANCER LETTERS, v.118, no.1,Sept.16, 1997, ELSEVIER SCIENCE IRELAND LTD, CLARE, p.13-19.

3) Lejbkowicz,F., "Distinct sensitivity of normal and malignant cells to ultrasound in vitro", ENVIRONMENTAL HEALTH PERSPECTIVES , Dec.1997, US DEPARTMENT OF HEALTH AND HUMAN SERVICES PUBLIC HEALTH SERVICE - RES TRIANGLE PK, p.1575-1578.

4) Kluiwstra,J.U., " Therapeutic ultrasound phased arrays: Practical consideration and design strategies", 1996 IEEE ULTRASONICS SYMPOSIUM, PROCEEDINGS, VOLS 1 AND 2 1051-0117, p.1277-1280.

5) JM Correas, "Ultrasound contrast agents - Examples of blood pool agents", ACTA RADIO-LOGICA, v. 38,Suppl 2, 1997, MUNKSGAARD INT PUBL LTD, COPENHAGEN,p 101-112.

6) CB Grissom," Sonolysis promotes indirect Co-C pond cleavage of alkylcob(III)alamin bioconjugates", BIOCONJUGATE CHEMISTRY, AMERICAN CHEMICAL SOCIETY, WASHINGTON, v.8, no.4, Jul-Aug 1977, p.498-502.

7) J Kost, "Mass transport enhancement by ultrasound in non-degradable polymeric controlled release systems", JOURNAL OF CONTROLLED RELEASE , v. 54, no.1, June, 1998, ELSEVIER SCIENCE BV, AMSTERDAM , p.1-7.

8) MR Prausnitz, "Non-invasive assessment and control of ultrasound-mediated membrane permeabilization", PHARMACEUTICAL RESEARCH, v. 15 no. 6, PLENUM PUBLISHING CORP, NEW YORK, June 1998, p.918-924.

9) JR Wu, "Defects generated in human stratum corneum specimens by ultrasound", ULTRASOUND IN MEDICINE AND BIOLOGY, v.24, no.5, June 1998, PERGAMON-ELSEVIER SCIENCE LTD, OXFORD, p.705-710.

10) L Machet," In vitro phonophoresis of mannitol, oestradiol and hydrocortisone across human and hairless mouse skin", INTERNATIONAL JOURNAL OF PHARMACEUTICS, v.165, no.2, May 14,1998, ELSEVIER SCIENCE BV, AMSTERDAM, p.169-174.

11) PJA Frinking," Effect of ultrasound on the release of micro-encapsulated drugs", ULTRASONICS, v.36,no.1-5, Feb. 1998, ELSEVIER SCIENCE BV, AMSTERDAM, p.709-712.

12) M Hippius, "In vitro investigations of drug release and penetration - enhancing effect of ultrasound on transmembrane transport of flufenamic acid", INTERNATIONAL JOURNAL OF CLINICAL PHARMACOLOGY AND THERAPEUTICS, v.36 no.2 ,Feb. 1998, DUSTRI-VERLAG DR KARL FEISTLE, MUNCHEN-DEISENHOFEN, p. 107-111.

13) RJ Siegel, "Noninvasive in vivo clot dissolution without a thrombolytic drug recanalization of thrombosed iliofemoral arteries by transcutaneous ultrasound combined with intravenous infusion of microbubbles", CIRCULATION, v. 97, no. 2, Jan. 20, 1998, AMERICAN HEART ASSOCIATION, DALLAS.

14) S Kaul, "Direct in vivo visualization of intravascular destruction of microbubbles by ultrasound and its local effects on tissue", CIRCULATION, v.98,no.4, July 28, 1998, WILLIAMS & WILKINS, BALTIMORE, p.290-293.

15) MW Miller, "Obstetric ultrasonography: A biophysical consideration of patient safety - The "rules" have changed", AMERICAN JOURNAL OF OBSTETRICS AND GYNECOLOGY, v. 179,no. 1, July 1998, MOSBY-YEAR BOOK INC, ST LOUIS, p.241-254.

16) WI Gruszecki, "Effect of amphotericin B on dipalmitoylphosphatidylcholine membranes: calorimetry, ultrasound absorption and monolayer technique studies", BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES, v. 1373, no.1, Aug.8,1998, ELSEVIER SCIENCE BV, AMSTERDAM, p.220-226.

17) Tachibana,K. "Intramural drug delivery by ultrasound energy", CIRCULATION, v 96, no.8 Suppl, Nov.21,1997, AMERICAN HEART ASSOCIATION, DALLAS, p 1533-1539.

18) RJ Price, "Delivery of colloidal, particles and red blood cells to tissue through microvessel ruptures created by targeted microbubble destruction with ultrasound", CIRCULATION, v. 98, no. 13, Sept. 29, 1998, WILLIAMS & WILKINS, BALTIMORE, p.1264-1267.

19) H Onyuksel, "In vitro targeting of acoustically reflective immunoliposomes to fibrin under various flow conditions", JOURNAL OF DRUG TARGETING, v.5, no. 6, 1998, HARWOOD ACADEMIC PUBLISHING GMBH, READING, p.507-518.

20) P VanBaren, "Image-guided phased array system for ultrasound thermotherapy", 1996 IEEE ULTRASONICS SYMPOSIUM, PROCEEDINGS, VOLS 1 AND 2, BH56C, SN 1051-0117, p.1269-1272.

Welcome  to  our  new  website ! Our shop talk section is to respond to you, our customers, and  to  keep  our  users  posted  on  the  latest  developments  in  sonochemistry  and  other applications of high intensity, near-megahertz ultrasonic energy. 

Changes in the SONOCHEMIST! Our engineers found a way to provide five power settings for the Sonochemist without adding too much weight or heat dissipation.   We   are including this option in all future Sonochemists.   For a while, the price will not change.   If you have a Sonochemist now on order, it will be shipped with this option at no additional charge.

The new Sonochemist has a five-position rotary switch mounted on its top. Using this switch you   can   select   50, 100, 150, 200, or 250 watts ( acoustic ) output.   Just   the   thing for determining  the   "dynamics"   of   a   reaction. These settings are NOT exact, and the actual power depends on the actual 120VAC "mains" voltage at your facility.

Don't forget about our Technical-Literature Database Search Service.

UES  maintains  a  current  list  of  the  abstracts  from  the  scientific literature which relate to high-intensity  ultrasound.  Our  service  consists  of  scanning  this  database  using keywords provided  by  our  customers  or  prospective  customers.  The  hits  from  this scan are either mailed  or  FAXed  to  the  requesting party, depending on the volume of hits. If the list is too very  long  we  will  not  do the search: for instance, the word cavitation will basically hit our entire database. But the word phenol will produce maybe twenty hits. 

To   request   a  search,  email  your  proposed  ( up to three )  keywords.  Please  keep  the keywords as specific as possible: if no hits result, you can expand your search later. You can email us by using this link contact info . 

We reserve the right to prioritize these searches. Old customers get top priority, of course. It never  hurts  to tell us why your search should precede others, or to tell us a little of what you can about your research. 

While on the subject of telling what you can about your research. The general rule is be safe: never  tell us too much. Not that we are "blabby". In fact, we are working at any given time with  several  researchers  who  are  either  developing  an  industrial process, or preparing to publish a scientific  paper.  These researchers don't want their information leaked, and we are very  careful  not  to leak it. But from time to time we find that researcher A could profit from what researcher B is doing. In these cases we ask for permission from both to supply contact information  to  the  other,  without  mentioning  names.  We  have  arranged  several valuable contacts among our customers in this way. 

While visiting our site, please have a look at the UES300C Sonochemist Technical Manual. It  has  some  tips on ultrasonic calibration which some will find helpful. It also talks about the origin  of  the Sonochemist, which was from more powerful machines, and not vice versa as is usually the case. The Technical Manual also cautions against running the transducer hot, a prohibition  which  extends  to  all  of  our  transducers. It talks about how to run the solution under test at elevated temperatures, and  external  gas sparging. For beginners, this is a good place to look to get an idea of how sonochemistry is done. 

Those  of  you  who  are  associated  with  a  website  where  ultrasonics is important, please contact us about cross-linking. Our list of  Offsite Links  will grow with time. 

Welcome, once again, to our site !