Acoustic Pressure

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Bing Yang - One of the best experts on this subject based on the ideXlab platform.

  • instability of sonoluminescing bubbles under a nonspherical symmetrical Acoustic Pressure perturbation
    Physical Review E, 2005
    Co-Authors: Bing Yang
    Abstract:

    The perturbation of nonspherical symmetrical Acoustic Pressure is added to the equation governing the spherical stability of sonoluminescing bubbles. The numerical calculations of the shape instability of sonoluminescing bubbles with the modified equation are conducted and the results are illustrated accordingly in the ${p}_{a}\text{\penalty1000-\hskip0pt}{R}_{0}$ phase diagrams. The calculated results indicate that the stability region vanishes as the amplitude of the driving Acoustic Pressure ${p}_{a}$ arrives at the upper threshold $(\ensuremath{\sim}1.6\phantom{\rule{0.3em}{0ex}}\mathrm{atm})$ due to the perturbation of a small nonspherical symmetrical Acoustic Pressure (about a few Pa), which is in consistence with the experimental observations.

  • Instability of sonoluminescing bubbles under a nonspherical symmetrical Acoustic-Pressure perturbation.
    Physical review. E Statistical nonlinear and soft matter physics, 2005
    Co-Authors: Bing Yang
    Abstract:

    The perturbation of nonspherical symmetrical Acoustic Pressure is added to the equation governing the spherical stability of sonoluminescing bubbles. The numerical calculations of the shape instability of sonoluminescing bubbles with the modified equation are conducted and the results are illustrated accordingly in the p(a) - R0 phase diagrams. The calculated results indicate that the stability region vanishes as the amplitude of the driving Acoustic Pressure p(a) arrives at the upper threshold ( approximately 1.6 atm) due to the perturbation of a small nonspherical symmetrical Acoustic Pressure (about a few Pa), which is in consistence with the experimental observations.

Morton W. Miller - One of the best experts on this subject based on the ideXlab platform.

  • Hemolysis of 40% hematocrit, Albunex-supplemented human erythrocytes by pulsed ultrasound: frequency, Acoustic Pressure and pulse length dependence.
    Ultrasound in medicine & biology, 1997
    Co-Authors: Andrew A. Brayman, Peggy L. Strickler, Huong Luan, Susan L. Barned, Carol H. Raeman, Christopher Cox, Morton W. Miller
    Abstract:

    Abstract The dependence of hemolysis produced by pulsed ultrasound on ultrasound frequency, Acoustic Pressure and pulse length was explored. Human erythrocytes (40% hematocrit; in Albunex ® -supplemented autologous plasma) were exposed (60 s) to 20 or 200 μs pulses of ultrasound at frequencies of 1.02, 2.24 or 3.46 MHz and at peak negative Pressures [P − ] ranging from 0.0 to ∼3.0 MPa in 0.5 MPa increments. The duty factor was 0.01. At each frequency, hemolysis increased with increasing Acoustic Pressure and depended weakly on pulse duration. At relatively high Acoustic Pressures, hemolysis depended strongly on ultrasound frequency; at lower Pressures, the frequency dependence was weaker. The potential clinical significance of ultrasonic hemolysis is discussed.

  • hemolysis of 40 hematocrit albunex supplemented human erythrocytes by pulsed ultrasound frequency Acoustic Pressure and pulse length dependence
    Ultrasound in Medicine and Biology, 1997
    Co-Authors: Andrew A. Brayman, Peggy L. Strickler, Huong Luan, Susan L. Barned, Carol H. Raeman, Christopher Cox, Morton W. Miller
    Abstract:

    Abstract The dependence of hemolysis produced by pulsed ultrasound on ultrasound frequency, Acoustic Pressure and pulse length was explored. Human erythrocytes (40% hematocrit; in Albunex ® -supplemented autologous plasma) were exposed (60 s) to 20 or 200 μs pulses of ultrasound at frequencies of 1.02, 2.24 or 3.46 MHz and at peak negative Pressures [P − ] ranging from 0.0 to ∼3.0 MPa in 0.5 MPa increments. The duty factor was 0.01. At each frequency, hemolysis increased with increasing Acoustic Pressure and depended weakly on pulse duration. At relatively high Acoustic Pressures, hemolysis depended strongly on ultrasound frequency; at lower Pressures, the frequency dependence was weaker. The potential clinical significance of ultrasonic hemolysis is discussed.

Linda K. Weavers - One of the best experts on this subject based on the ideXlab platform.

  • combining comsol modeling with Acoustic Pressure maps to design sono reactors
    Ultrasonics Sonochemistry, 2016
    Co-Authors: Zongsu Wei, Linda K. Weavers
    Abstract:

    Scaled-up and economically viable sonochemical systems are critical for increased use of ultrasound in environmental and chemical processing applications. In this study, computational simulations and Acoustic Pressure maps were used to design a larger-scale sono-reactor containing a multi-stepped ultrasonic horn. Simulations in COMSOL Multiphysics showed ultrasonic waves emitted from the horn neck and tip, generating multiple regions of high Acoustic Pressure. The volume of these regions surrounding the horn neck were larger compared with those below the horn tip. The simulated Acoustic field was verified by Acoustic Pressure contour maps generated from hydrophone measurements in a plexiglass box filled with water. These Acoustic Pressure contour maps revealed an asymmetric and discrete distribution of Acoustic Pressure due to Acoustic cavitation, wave interaction, and water movement by ultrasonic irradiation. The Acoustic Pressure contour maps were consistent with simulation results in terms of the effective scale of cavitation zones (∼ 10 cm and <5 cm above and below horn tip, respectively). With the mapped Acoustic field and identified cavitation location, a cylindrically-shaped sono-reactor with a conical bottom was designed to evaluate the treatment capacity (∼ 5 L) for the multi-stepped horn using COMSOL simulations. In this study, verification of simulation results with experiments demonstrates that coupling of COMSOL simulations with hydrophone measurements is a simple, effective and reliable scientific method to evaluate reactor designs of ultrasonic systems.

  • Combining COMSOL modeling with Acoustic Pressure maps to design sono-reactors.
    Ultrasonics sonochemistry, 2016
    Co-Authors: Zongsu Wei, Linda K. Weavers
    Abstract:

    Scaled-up and economically viable sonochemical systems are critical for increased use of ultrasound in environmental and chemical processing applications. In this study, computational simulations and Acoustic Pressure maps were used to design a larger-scale sono-reactor containing a multi-stepped ultrasonic horn. Simulations in COMSOL Multiphysics showed ultrasonic waves emitted from the horn neck and tip, generating multiple regions of high Acoustic Pressure. The volume of these regions surrounding the horn neck were larger compared with those below the horn tip. The simulated Acoustic field was verified by Acoustic Pressure contour maps generated from hydrophone measurements in a plexiglass box filled with water. These Acoustic Pressure contour maps revealed an asymmetric and discrete distribution of Acoustic Pressure due to Acoustic cavitation, wave interaction, and water movement by ultrasonic irradiation. The Acoustic Pressure contour maps were consistent with simulation results in terms of the effective scale of cavitation zones (∼ 10 cm and

Andrew A. Brayman - One of the best experts on this subject based on the ideXlab platform.

  • Hemolysis of 40% hematocrit, Albunex-supplemented human erythrocytes by pulsed ultrasound: frequency, Acoustic Pressure and pulse length dependence.
    Ultrasound in medicine & biology, 1997
    Co-Authors: Andrew A. Brayman, Peggy L. Strickler, Huong Luan, Susan L. Barned, Carol H. Raeman, Christopher Cox, Morton W. Miller
    Abstract:

    Abstract The dependence of hemolysis produced by pulsed ultrasound on ultrasound frequency, Acoustic Pressure and pulse length was explored. Human erythrocytes (40% hematocrit; in Albunex ® -supplemented autologous plasma) were exposed (60 s) to 20 or 200 μs pulses of ultrasound at frequencies of 1.02, 2.24 or 3.46 MHz and at peak negative Pressures [P − ] ranging from 0.0 to ∼3.0 MPa in 0.5 MPa increments. The duty factor was 0.01. At each frequency, hemolysis increased with increasing Acoustic Pressure and depended weakly on pulse duration. At relatively high Acoustic Pressures, hemolysis depended strongly on ultrasound frequency; at lower Pressures, the frequency dependence was weaker. The potential clinical significance of ultrasonic hemolysis is discussed.

  • hemolysis of 40 hematocrit albunex supplemented human erythrocytes by pulsed ultrasound frequency Acoustic Pressure and pulse length dependence
    Ultrasound in Medicine and Biology, 1997
    Co-Authors: Andrew A. Brayman, Peggy L. Strickler, Huong Luan, Susan L. Barned, Carol H. Raeman, Christopher Cox, Morton W. Miller
    Abstract:

    Abstract The dependence of hemolysis produced by pulsed ultrasound on ultrasound frequency, Acoustic Pressure and pulse length was explored. Human erythrocytes (40% hematocrit; in Albunex ® -supplemented autologous plasma) were exposed (60 s) to 20 or 200 μs pulses of ultrasound at frequencies of 1.02, 2.24 or 3.46 MHz and at peak negative Pressures [P − ] ranging from 0.0 to ∼3.0 MPa in 0.5 MPa increments. The duty factor was 0.01. At each frequency, hemolysis increased with increasing Acoustic Pressure and depended weakly on pulse duration. At relatively high Acoustic Pressures, hemolysis depended strongly on ultrasound frequency; at lower Pressures, the frequency dependence was weaker. The potential clinical significance of ultrasonic hemolysis is discussed.

Masao Watanabe - One of the best experts on this subject based on the ideXlab platform.

  • Formation of a submillimeter bubble from an orifice using pulsed Acoustic Pressure waves in gas phase
    Physics of Fluids, 2008
    Co-Authors: Minori Shirota, Toshiyuki Sanada, Ayaka Sato, Masao Watanabe
    Abstract:

    The mechanism of a bubble production method using pulsed Acoustic Pressure waves in gas phase is investigated using high-speed photography. The Acoustic characteristics of the present bubble generator are also investigated. We found out the optimal Acoustic waveform for producing only one bubble per one action; the bubble detachment radius is accurately controlled by first applying the positive onset-assistance Acoustic Pressure wave and then the negative detachment-assistance Acoustic Pressure wave with an accurately controlled time lapse. From an orifice with a radius of 0.09mm submerged in water, bubbles with radii in the range of 0.28–0.78mm with an extremely small standard deviation of less than 1μm are obtained. The shrinking and pinch-off motions of a capillary bridge connecting the bubble and orifice at the time of bubble detachment are observed in detail. The balancing force on a growing bubble, which is based on a spherical bubble formation model is also estimated. As a result, we reveal that wh...