# Sonochemical Cavitation. **URL:** \ **Category:** Factual Questions\ **Created:** [October 10, 2004, 10:14pm UTC](https://boards.straightdope.com/t/sonochemical-cavitation/268522 "2004-10-10T22:14:12Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![Bear\_Nenno](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bear_nenno/32/3358_2.png) [@Bear\_Nenno](https://boards.straightdope.com/u/Bear_Nenno)\ **Post date:** [October 10, 2004, 10:14pm UTC](https://boards.straightdope.com/t/sonochemical-cavitation/268522/1 "2004-10-10T22:14:12Z")
Could someone give me the simple Straight Dope on this. What the heck is it. What effect does it have. What dangers, if any, does it pose in the brains of humans. I was looking up some info and found a short sentence on dolphins capable of causing cavitation with their ecolocation. And that there have been noticed effects in people after have contact with dolphins. That was all it said!! How are you going to leave someone hanging like that. What are the effects??? I have a vested interest in this since I work with dolphins weekly! Are they killing me!? Am I going to be retarded (ok, _more_ retarded) soon?? ---
**Author:** ![astro](https://avatars.discourse-cdn.com/v4/letter/a/9dc877/32.png) [@astro](https://boards.straightdope.com/u/astro)\ **Post date:** [October 10, 2004, 11:40pm UTC](https://boards.straightdope.com/t/sonochemical-cavitation/268522/2 "2004-10-10T23:40:33Z")
It’s basically talking about the effects of powerful utrasound impulses. Ultrasound can cause hazardous effects if powerful enough, mainly through heat generation and possibly cell disruption. Whether a dolphins echo location and ultrasonic communication output is powerful enough to cause these effects is unknown to me. [Here’s a page about it](http://www.fb-chemie.uni-rostock.de/ess/sonochem_intro.htm) > [@](#): > > Fundamentals > What is Sonochemistry ? > > Sonochemistry is the application of ultrasound to chemical reactions and processes. Ultrasound is the part of the sonic spectrum which ranges from about 20 kHz to 10 MHz and can be roughly subdivided in three main regions: low frequency, high power ultrasound (20-100 kHz), high frequency, medium power ultrasound (100 kHz-1 MHz), and high frequency, low power ultrasound (1-10 MHz). The range from 20 kHz to around 1 MHz is used in sonochemistry wheras frequencies far above 1 MHz are used as medical and diagnostic ultrasound. > Acoustic Cavitation > > The origin of sonochemical effects in liquids is the phenomenon of acoustic cavitation. The term cavitation comes from the latin word cavus = cavity. Acoustical energy is mechanical energy i.e. it is not absorbed by molecules. Ultrasound is transmitted through a medium via pressure waves by inducing vibrational motion of the molecules which alternately compress and stretch the molecular structure of the medium due to a time-varying pressure. Therefore, the distance among the molecules vary as the molecules oscillate around their mean position. If the intensity of ultrasound in a liquid is increased, a point is reached at which the intramolecular forces are not able to hold the molecular structure intact. Consequently, it breaks down and a cavity is formed. This cavity is called cavitation bubble as this process is called cavitation and the point where it starts cavitation threshold. A bubble responds to the sound field in the liquid by expanding and contracting, i.e. it is excited by a time-varying pressure.Two forms of cavitation are known: stable and transient. Stable cavitation means that the bubbles oscillate around their equilibrium position over several refraction/compression cycles. While transient cavitation, the bubbles grow over one (sometimes two or three) acoustic cycles to double their initial size and finally collapse violently. > The size, life time and fate of a cavitation bubble depend on the following parameters: frequency, intensity (acoustic pressure), solvent, bubbled gas, external parameter (temperature, pressure). However, it should be noted that there is often no simple relationship > [@](#): > > Ultrasound in Life Sciences and Medicine > > Firstly, applications without any destruction or damage on living tissues : > disturbing of dermal cell membranes used for drug delivery (sonophoresis) > ultrasonic imaging > ultrasound nmr > diagnostic ultrasound > dental scaling and ultrasonic nebulizers in medical therapy > enzyme activation > > Secondly, ultrasound caused damage on living tissues : > cell disrupture (extraction of plant substances, disinfecting, enzyme deactivation) > therapeutic ultrasound, i.e. induction of thermolysis in tissues (cancer treatment) > > Thirdly, sonochemical preparation of biomaterials > air-filled protein microbubbles > nonaqueous liquid-filled protein microcapsules ---
**Author:** ![Bear\_Nenno](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bear_nenno/32/3358_2.png) [@Bear\_Nenno](https://boards.straightdope.com/u/Bear_Nenno)\ **Post date:** [October 11, 2004, 7:38am UTC](https://boards.straightdope.com/t/sonochemical-cavitation/268522/3 "2004-10-11T07:38:10Z")
> [@Linked Article](#): > > The range from **20 kHz to around 1 MHz** is used in sonochemistry wheras frequencies far above 1 MHz are used as medical and diagnostic ultrasound. (bolding mine) EEK! That is well within the capabilities of a dolphin! Holy Crap, they’re killing my molecules! Thank goodness I have so many, right? ---
**Author:** ![Bear\_Nenno](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bear_nenno/32/3358_2.png) [@Bear\_Nenno](https://boards.straightdope.com/u/Bear_Nenno)\ **Post date:** [October 11, 2004, 7:40am UTC](https://boards.straightdope.com/t/sonochemical-cavitation/268522/4 "2004-10-11T07:40:43Z")
> [@Linked Article](#): > > …enhancement of the reactivity of reagents or catalysts > generation of useful reactive species Wait! That sounds like a good thing.