Friday, November 4, 2011
These pressure variations cause corresponding changes in permeability of cell membranes and, in the case of fat cells, lead to the release of complex molecules ie they contain fat, which fall into the circulatory system and are mostly processed lymphatic system and the small circle of blood circulation. Another no thermal effect called cavitation. Using Low frequency ultrasound has generated a complex phenomenon that underlies the new systems used in aesthetic medicine and surgery. The first study of cavitation. In some industrial applications of ultrasound Cavitation is an undesirable phenomenon and represents a source of various problems. This effect was observed due to the use of ultrasound in a liquid containing dissolved gas, because the decrease local pressure below the vapor pressure of the fluid itself provokes a change in the phase of gas and formation of numerous microscopic bubbles that contain vapor or gas. Cavitation of liquids can be a constant when the diameter microbubble exposed to cyclical fluctuations in relation to changes in pressure acoustic waves, but despite this, mikropuzyrek not explode, because the internal steam pressure equalizes pressure surrounding fluid. If we are talking about unstable cavitation bubble is not broken just as long as there is in the area of low hydrostatic pressure: as soon as the bubble back into the zone of fluid quiescent state, the vapor pressure becomes insufficient to counteract the pressures of the external fluid, and subsequent ultrasound waves cause a sudden contraction and rapid destruction of the bubble. A powerful release kinetic energy in the form of strong waves causes a change in mechanical pressure and heat transfer phenomena, which can erode any solid material with which touch each other, until the formation of holes.