Ultrasonic cavitation bubble- and gas bubble-assisted adsorption of paclitaxel from Taxus chinensis onto Sylopute

In order to understand the influencing factors and laws on the ultrasonic cavitation dynamics in chitosan solution, numerical simulation of cavitation bubble motion had been performed based on Rayleigh-Plesset equation and the equation was solved by using 4~5 order Runge–Kutta algorithm. By numerical simulation the effects of frequency and intensity of ultrasonic, ambient pressure, initial bubble radius, concentration and temperature of solution, dual-frequency ultrasonic on the motion of cavitation bubble were discussed. The results show that for improving the effect of cavitation in chitosan solution, ultrasonic cavitation should be under the conditions of lower frequency, lower intensity, lower ambient pressure, smaller initial cavitation bubble, moderate temperature of solution and lower concentration. It is also found that the cavitation intensity due to dual-frequency ultrasonic is stronger than that of single-frequency ultrasonic.

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Simulation on the effects of various factors on the motion of ultrasonic cavitation bubble

Mathematical Modelling and Engineering Problems ◽

10.18280/mmep.040406 ◽

2017 ◽

Vol 4 (4) ◽

pp. 173-178

Author(s):

Wanxin Qu ◽

Yuanhua Xie ◽

Yang Shen ◽

Jin Han ◽

Meiyan You ◽

...

Keyword(s):

Cavitation Bubble ◽

Ultrasonic Cavitation

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The Collapse of a Gas Bubble near a Solid Wall by a Shock Wave and the Induced Impulsive Pressure

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1243/pime_proc_1984_198_092_02 ◽

1984 ◽

Vol 198 (2) ◽

pp. 81-86 ◽

Cited By ~ 3

Author(s):

A Shima ◽

Y. Tomita ◽

K Takahashi

Keyword(s):

Shock Wave ◽

Experimental Study ◽

Cavitation Bubble ◽

Solid Wall ◽

Impact Pressure ◽

Bubble Collapse ◽

Gas Bubble ◽

Bubble Interaction ◽

The Impact ◽

Impulsive Pressure

An experimental study concerning the shock wave—bubble interaction was conducted in order to obtain a unified consideration of the mechanism of the impulsive pressure generation induced by the cavitation bubble collapse. It was found that the relation between the maximum impulsive pressure, pG, max, and the relative distance, lc/Re, is closely similar to the known result obtained from a single spark-generated bubble, and that a gas bubble within the region of lc/Re ≤ 7 behaves as a source capable of generating more intensive impulsive pressure than the impact pressure induced by a shock wave impinging directly on a solid wall without the presence of a gas bubble.

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Bubble Structures Between Two Walls in Ultrasonic Cavitation Erosion

Journal of Tribology ◽

10.1115/1.4005217 ◽

2012 ◽

Vol 134 (2) ◽

Cited By ~ 9

Author(s):

A. Abouel-Kasem ◽

S. M. Ahmed

Keyword(s):

Failure Mode ◽

Cavitation Bubble ◽

Cluster Size ◽

Cavitation Erosion ◽

Separation Distance ◽

Ultrasonic Cavitation ◽

Material Failure ◽

Huge Number ◽

Maximum Cluster ◽

Ultrasonic Cavitation Erosion

The cavitation bubble structures for the stationary specimen method were clarified for various distances, h, between the stationary specimen and the horn-tip surface. The generated cavitation bubbles constituted a huge number of tiny bubbles and bubble clusters of different sizes. The maximum cluster size was 1.4 mm. The observed cavitation patterns systematically changed during tests from the subcavitating state to the supercavitating state with respect to the separation distance, h. For h <4 mm, the bubbles have a definite trajectory, and the pressure patterns manifest a circular shape as a result of streaming induced by ultrasonic cavitation. The feature morphology of the eroded surfaces revealed that the predominant failure mode was fatigue. In the light of the material failure features and the cavitation patterns, it is also deduced that the important mechanism to transfer the cavitation energy to the solid is shock pressures accompanied by collapsing clusters.

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Platelet Aggregation Induced in Vitro by Therapeutic Ultrasound

Thrombosis and Haemostasis ◽

10.1055/s-0038-1651879 ◽

1977 ◽

Vol 38 (03) ◽

pp. 0640-0651 ◽

Cited By ~ 29

Author(s):

B. V Chater ◽

A. R Williams

Keyword(s):

Platelet Aggregation ◽

Direct Action ◽

Adenosine Diphosphate ◽

Ultrasonic Cavitation ◽

Related Phenomenon ◽

Release Reaction ◽

Physical Conditions ◽

Platelet Aggregates ◽

Active Substances

SummaryPlatelets were found to aggregate spontaneously when exposed to ultrasound generated by a commercial therapeutic device. At a given frequency, aggregation was found to be a dose-related phenomenon, increasing intensities of ultrasound inducing more extensive and more rapid aggregation. At any single intensity, the extent aggregation was increased as the frequency of the applied ultrasound was decreased (from 3.0 to 0.75 MHz).Ultrasound-induced platelet aggregation was found to be related to overall platelet sensitivity to adenosine diphosphate. More sensitive platelets were found to aggregate spontaneously at lower intensities of sound, and also the maximum extent of aggregation was found to be greater. Examination of ultrasound-induced platelet aggregates by electron microscopy demonstrated that the platelets had undergone the release reaction.The observation that haemoglobin was released from erythrocytes in whole blood irradiated under identical physical conditions suggests that the platelets are being distrupted by ultrasonic cavitation (violent gas/bubble oscillation).It is postulated that overall platelet aggregation is the result of two distinct effects. Firstly, the direct action of ultrasonic cavitation disrupts a small proportion of the platelet population, resulting in the liberation of active substances. These substances produce aggregation, both directly and indirectly by inducing the physiological release reaction in adjacent undamaged platelets.

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Treatment of ulcer-necrotic manifestations of diabetic foot using ultrasonic cavitation

Endocrine Abstracts ◽

10.1530/endoabs.35.p416 ◽

2014 ◽

Author(s):

Maksym Prystupiuk ◽

Iuliia Onofriichuk ◽

Liudmyla Naumova ◽

Lev Prystupiuk ◽

Marianna Naumova ◽

...

Keyword(s):

Diabetic Foot ◽

Ultrasonic Cavitation

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