Mathematical and physical modelling of bubble growth due to ultrasound

Meidani, A.R. Naji; Hasan, Mainul

doi:10.1016/j.apm.2003.10.001

Cited by 42 publications

(14 citation statements)

References 10 publications

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“…This process favors bubble growth for two main reasons: (i) the “area” effect, and (ii) the “shell” effect. [71] The “area” effect simply occurs because the surface area of a bubble in the expanded state is much greater than in the collapsed state. Therefore, there is much greater area for diffusion into the bubble to occur in the expanded state than for diffusion out of the bubble to occur in the collapsed state.…”

Section: Introductionmentioning

confidence: 99%

Ultrasound-mediated transdermal drug delivery: Mechanisms, scope, and emerging trends

Polat

Hart

Langer

et al. 2011

Journal of Controlled Release

351

290

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The use of ultrasound for the delivery of drugs to, or through, the skin is commonly known as sonophoresis or phonophoresis. The use of therapeutic and high frequencies of ultrasound (≥ 0.7 MHz) for sonophoresis (HFS) dates back to as early as the 1950s, while low-frequency sonophoresis (LFS, 20 – 100 kHz) has only been investigated significantly during the past two decades. Although HFS and LFS are similar because they both utilize ultrasound to increase the skin penetration of permeants, the mechanisms associated with each physical enhancer are different. Specifically, the location of cavitation and the extent to which each process can increase skin permeability are quite dissimilar. Although the applications of both technologies are different, they each have strengths that could allow them to improve current methods of local, regional, and systemic drug delivery. In this review, we will discuss the mechanisms associated with both HFS and LFS, specifically concentrating on the key mechanistic differences between these two skin treatment methods. Background on the relevant physics associated with ultrasound transmitted through aqueous media will also be discussed, along with implications of these phenomena on sonophoresis. Finally, a thorough review of the literature is included, dating back to the first published reports of sonophoresis, including a discussion of emerging trends in the field.

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Section: Introductionmentioning

confidence: 99%

Ultrasound-mediated transdermal drug delivery: Mechanisms, scope, and emerging trends

Polat

Hart

Langer

et al. 2011

Journal of Controlled Release

351

290

View full text Add to dashboard Cite

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“…When an external force is applied, e.g. via ultrasound, and cavitation conditions are met above the threshold acoustic pressure amplitude, a bubble of a given size will form and grow, while smaller bubbles will tend to dissolve by diffusing gas back into the melt [6,7,35] that might be happened for some bubbles (not attached to the crucible surface) above the field of view in this experiment.…”

Section: Time-resolved Radiographsmentioning

confidence: 99%

“…[38]. It is known that bubbles smaller than the resonance size tend to dissolve into the melt [35], increasing the local hydrogen concentration in the melt and providing additional stimulus (via gas gradient) for the growth of larger cavitation bubbles. Fig.…”

Section: (C) and (D)mentioning

confidence: 99%

Synchrotron quantification of ultrasound cavitation and bubble dynamics in Al–10Cu melts

Tzanakis

Srirangam

et al. 2016

Ultrasonics Sonochemistry

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Knowledge of the kinetics of gas bubble formation and evolution under cavitation conditions in molten alloys is important for the control casting defects such as porosity and dissolved hydrogen. Using in situ synchrotron X-ray radiography, we studied the dynamic behaviour of ultrasonic cavitation gas bubbles in a molten Al-10 wt% Cu alloy. The size distribution, average radius and growth rate of cavitation gas bubbles were quantified under an acoustic intensity of 800 W/cm 2 and a maximum acoustic pressure of 4.5 MPa (45 atm).Bubbles exhibited a log-normal size distribution with an average radius of 15.3 ± 0.5 µm.Under applied sonication conditions the growth rate of bubble radius, R(t), followed a power law with a form of R(t)=αt β , and α=0.0021 & β=0.89. The observed tendencies were discussed in relation to bubble growth mechanisms of Al alloy melts.

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“…Cavitation is the formation of vapor cavities in the cell solution. Cavitation may be inertial or stable [11][12][13][14][15]. The former occurs at lower intensity: the bubbles oscillate about some equilibrium size for many acoustic cycles.…”

Section: Introductionmentioning

confidence: 99%

Study of cellular response induced by low intensity ultrasound frequency sweep pattern on myelomonocytic lymphoma U937 cells

et al. 2016

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Purpose This study will analyze the mechanical effects (immediate lysis) and biological effects (cell survival, apoptosis, cell cycle) on U937 cells subjected to different sonication conditions with increasing and decreasing frequencies and burst rate (number of burst of a repeating signal in a specific time unit), in order to determine the best conditions of sonication to produce high mortality, apoptosis and inhibition of hyperproliferation. Method Cells are been stressed by pulse wave ultrasounds with increasing and decreasing frequencies between 400 and 620 kHz, at burst rates of 0.5, 10, 50 Hz and 50 % duty cycle (percentage of one period in which a signal is active), ultrasound intensities (spatial average-temporal peak) 0.045 and 0.09 W/cm 2 . The sonication durations were 90 and 180 s. Results The decreasing mode was found to be better than the increasing mode for 10 and 50 Hz burst rates, while at 0.5 Hz the increasing mode gave better results for the time of 180 s. For 10 Hz burst rate, decreasing frequency, 180 s, 0.09 W/cm 2 , 20 % survival rate was found; after 6-h incubation, cells showed 13 % of early apoptosis and 11 % of late apoptosis. For these conditions of sonication, the hyperproliferation of cells was inhibited. Conclusion Survival rate decreases for increasing intensity and duration with each burst rate. The best performance is decreasing mode in a range between 620 and 400 kHz, duty cycle 50 %, burst rate 10 Hz. In these conditions after 180 s duration, the average survival rate is 20 %, the survived cells manifest apoptosis after 6-h incubation and hyperproliferation is prevented. The results seem to lead toward a non-invasive and effective purging of leukemic cells.Keywords Low intensity ultrasound Á Cell lysis Á Hyperproliferation apoptosis Á Cell cycle Sommario Scopo Questo studio analizzerà gli effetti meccanici (lisi valutata immediatamente dopo la sonicazione) e gli effetti biologici (sopravvivenza delle cellule, apoptosis e lisi cellulare) su cellule U937 soggette a differenti condizioni di sonicazione con frequenze crescenti e decrescenti, a burst rate (numero di impulsi di un segnale che si ripete in una specifica unità di tempo) variabili, al fine di determinare le migliori condizioni di sonicazione per produrre alta mortalità, apoptosi e inibizione dell'iperproliferazione cellulare. Metodi Le cellule sono state sollecitate con ultrasuoni ad onda pulsata con frequenze crescenti e decrescenti fra 400 e 620 kHz a burst rate di 0.5 Hz, 10 Hz, 50 Hz, con un ciclo di lavoro (frazione di tempo in cui il segnale è attivo in proporzione al tempo totale) del 50 %, intensità (picco spaziale medio-temporale) 0.045 W/cm 2 and 0.09 W/cm 2 . I tempi di sonicazione erano di 90 s e 180 s. Risultati La modalità a frequenza decrescente risultava essere migliore di quella crescente per burst rate 10 Hz e 50 Hz, mentre a 0.5 Hz la modalità a frequenza crescente risultava migliore per un tempo di 180 s. Con un burst rate di 10 Hz, a frequenza decrescente fra 620 e 400 kHz, esposizione per ...

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Mathematical and physical modelling of bubble growth due to ultrasound

Cited by 42 publications

References 10 publications

Ultrasound-mediated transdermal drug delivery: Mechanisms, scope, and emerging trends

Ultrasound-mediated transdermal drug delivery: Mechanisms, scope, and emerging trends

Synchrotron quantification of ultrasound cavitation and bubble dynamics in Al–10Cu melts

Study of cellular response induced by low intensity ultrasound frequency sweep pattern on myelomonocytic lymphoma U937 cells

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