Page 1 of 1: radio---acoustic cavitation

lazybonezzz · Credits: 54715 My Scrapbook

wat is it?

kalika · Credits: 12507 My Scrapbook My Reading List 12 Books

If you focus ultrasonic waves into water, tiny bubbles will be produced, forming a fractal structure and radiating sound by themselves. This is a cavitation field being produced by a radially symmetric sound field of approximately 23 kHz.

The dissipation of acoustic energy and acoustic cavitation are two major reasons for bioeffects of ultrasound. When passing through a human body, the energy of an ultrasonic signal is scattered by regions of different acoustic impedance and absorbed locally through viscous shearing and relaxation processes.

The absorption leads to heating of blood and tissue and, together with the scattering, produces radiation pressure and acoustic streaming within blood
Radiation pressure forces in turn push up blood cells against vessel walls and may force the cells to aggregate

Acoustic streaming is known to increase the shear stresses, and therefore the likelihood of cell lysis , though the destruction of cells rarely occurs in the blood free of gas inclusions or cavitation bubbles

The most deleterious nonthermal bioeffects are produced by acoustic cavitation. Pressure waves of high intensity are capable to rupture blood and tissue, giving rise to the formation and oscillation of cavities, i.e. gas or vapor bubbles

It is precisely these cavitation bubbles that are responsible for

hemolysis

hemorrhage

DNA fragmentation

Cavitation inception is a threshold process and significantly depends on the presence of “nuclei” in the liquid. The nuclei are small pockets of gas which are trapped in conical pits of solid impurities or covered with organic or surface-active molecules

The more the quantity of “nuclei” in the liquid, the smaller the wave amplitude needed for cavitation inception. Like any natural liquid, blood has cavitation nucleation agents, and therefore sufficiently high-amplitude ultrasound pulses cavitate it

Encapsulated microbubbles, especially of very small size, can be considered as additional “man-made” cavitation nuclei. The administration of microbubbles in blood should therefore decrease its cavitation thresholds and enhance the risk of biological damage

kalika · Credits: 12507 My Scrapbook My Reading List 12 Books

BUBBLES CAN BE MICROBE KILLER

this principle of ultrasonic acoustic cavitation is utilized in dentistry...

the ultrasonic instruments along with irrigating fluids in root canal produce the CAVITATION of fluids and the kinetic energy of the collapsing bubbles leads to more intense desired effects in the canal systems than the instument alone...

In a liquid exposed to ultrasound, moderately increasing the pressure dramatically boosts microbe destruction,.. using powerful electric discharges in water to produce shock waves

the pressure, bursting bubbles, and light from the discharges combine to slay bacteria in complex ways.

DENTISTS have long known that ultrasound in liquids causes gas bubbles to form and then often collapse violently. When those bubbles implode in cleaning solutions, they break up dirt and destroy some microbes.

lazybonezzz · Credits: 54715 My Scrapbook

GREAT INFO KALIKA THANX A LOT
WATS UR REF?

kalika · Credits: 12507 My Scrapbook My Reading List 12 Books

Ref :FOR FIRST POST VISIT

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second post i ve summarised frm many places.. its called as ENDOSONICS

lazybonezzz · Credits: 54715 My Scrapbook

thanx a lot kalika

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