粘弾性液体中の被膜気泡(ND)

【共著論文】粘弾性液体中で超音波駆動される、膜で覆われた気泡の非線形振動を、分岐解析を用いて系統的に調べました。膜の存在によって、気泡が周期振動から複雑な多周期振動へと崩れる音圧の閾値が約80%上昇することがわかりました。膜の弾性と気泡周囲液体の粘弾性とのバランスを表す安定化指標を導入することで、超音波造影剤を含む複数のシェル材料に対し、振動レジームを分類しました。

これは、エジプト・メヌフィア大学、ロシア科学アカデミー・カザン科学センターの応用数学者との共同研究成果であり、Nonlinear Dynamics (top 10%ジャーナル, JCR 2024, JIF percentile: 93% (Mechanics), IF: 6.0) に採択されました。

Abu-Nab, A.K., Kanagawa, T. and Fedorov, Y.V., “Shell–polymer coupling reorganizes nonlinear bifurcation thresholds of ultrasound-driven encapsulated microbubbles in Oldroyd-B fluids,” Nonlinear Dynamics, Vol.~*(2026), in press

A paper has been accepted for publication in Nonlinear Dynamics (a top 10% journal; JCR 2024, JIF percentile: 93% in Mechanics; IF: 6.0).

Abu-Nab, A.K., Kanagawa, T. and Fedorov, Y.V., “Shell–polymer coupling reorganizes nonlinear bifurcation thresholds of ultrasound-driven encapsulated microbubbles in Oldroyd-B fluids,” Nonlinear Dynamics, Vol.~*(2026), in press.

This study systematically investigates the nonlinear oscillations of membrane-coated bubbles driven by ultrasound in viscoelastic liquids using bifurcation analysis. The presence of the membrane was found to raise the acoustic pressure threshold at which periodic oscillations break down into complex multi-periodic ones by approximately 80%. By introducing a stabilization measure that represents the balance between membrane elasticity and the viscoelasticity of the surrounding liquid, oscillation regimes were classified for several shell materials, including representative ultrasound contrast agents. This work was carried out as a collaborative research with applied mathematicians at Menoufia University, Egypt, and the Kazan Scientific Center of the Russian Academy of Sciences.