scholarly journals Volume pulsation and scattering of bubbles under the second Bjerknes force

2016 ◽  
Vol 65 (1) ◽  
pp. 014301
Author(s):  
Ma Yan ◽  
Lin Shu-Yu ◽  
Xian Xiao-Jun
Keyword(s):  
Bjerknes Force ◽  
Volume Pulsation

Simultaneously achieving self-toughening and self-reinforcing of polyethylene on an industrial scale using volume-pulsation injection molding

Polymer ◽  
2021 ◽  
Vol 213 ◽  
pp. 123324
Author(s):  
Sen Qin ◽  
Wen-hua Xu ◽  
Hao-wei Jiang ◽  
Huan-huan Zhang ◽  
Yue He ◽  
...  
Keyword(s):  
Injection Molding ◽  
Industrial Scale ◽  
Volume Pulsation

Effects of the second harmonic on the secondary Bjerknes force

1999 ◽  
Vol 59 (3) ◽  
pp. 3016-3021 ◽  
Author(s):  
Alexander A. Doinikov
Keyword(s):  
Second Harmonic ◽  
Bjerknes Force

Predicting Bubble Migration due to Bjerknes Force in a Complex 3D Geometry: Numerical and Experimental Results

2012 ◽  
Author(s):  
Francisco I. Valentin ◽  
Silvina Cancelos
Keyword(s):  
Acoustic Field ◽  
High Speed ◽  
Acoustic Pressure ◽  
Pressure Field ◽  
Piezoelectric Materials ◽  
Bubble Diameter ◽  
Absolute Pressure ◽  
Flowing Fluid ◽  
3D Geometry ◽  
Bjerknes Force

While the Bjerknes force is not the only force experienced by a bubble subjected to an acoustic field; studies of bubble translation in non-flowing fluid have identified Bjerknes force as being the most influential. Therefore, Bjerknes force can be used to trap bubbles in predefined locations of maximum and minimum absolute pressure. Specifically challenging is to determine these locations in complex geometries because direct measurement of the acoustic pressure for the whole system is generally not possible. The objective of this research is to numerically predict Bjerknes force effect on bubble migration and accumulation in a complex 3D geometry that includes piezoelectric materials, elastic materials and a fluid media. A numerical solution of the acoustic pressure field was obtained for this geometry, valid in the range of small pressure oscillations. Additionally, using the linearized Rayleigh-Plesset equation, which gives the volumetric oscillations of a bubble subjected to an acoustic field, the Bjerknes force was numerically computed. By knowing the Bjerknes force, a bubble migration pattern upon entering the system was predicted. A CMOS high speed camera was used to experimentally monitor bubble multimode excitation and bubble response to a stationary pressure field validating our numerical results. Results are presented for experiments conducted for a 1mm bubble diameter with acoustic fields ranging from 7 to 10 kHz which correspond to values of the structure and/or the bubble’s resonant frequency.

scholarly journals Modulation of the secondary Bjerknes force in multi-bubble systems

2020 ◽  
Vol 61 ◽  
pp. 104814 ◽  
Author(s):  
Haiyan Chen ◽  
Ziliang Chen ◽  
Yi Li
Keyword(s):  
Bjerknes Force

Right atrium mediates a vasomotor reflex

1981 ◽  
Vol 241 (3) ◽  
pp. R163-R166
Author(s):  
R. F. Munzner ◽  
D. G. Ward ◽  
D. S. Gann
Keyword(s):  
Right Atrium ◽  
Carotid Arteries ◽  
Right Atrial ◽  
Vagus Nerves ◽  
Vascular Responses ◽  
The Right ◽  
Vasomotor Reflex ◽  
Atrial Receptors ◽  
Volume Pulsation

To examine the role of right atrial receptors in mediating reflex vascular responses we measured, in cats anesthetized with chloralose/urethan, changes in mean arterial pressure (MAP) in response to volume pulsation of the right atrium (+/- 1 ml, 1 Hz). Changes in MAP were measured 1) with pressure in the carotid arteries normal and vagus nerves intact: right atrial pulsation led to a very small and transient fall in MAP; 2) with pressure in the carotid arteries at 75 mmHg and the vagus nerves intact: right atrial pulsation led to a larger and sustained fall in MAP; 3) with pressure in the carotid arteries at 75 mmHg and the vagus nerves cooled or sectioned bilaterally: right atrial pulsation of the right atrium led only to a very small and transient fall in MAP. These data suggest strongly that signals from right atrial receptors traveling in the vagus nerves mediate a reflex change in MAP that is normally masked by signals from carotid receptors.

scholarly journals 3D steerable, acoustically powered microswimmers for single-particle manipulation

2019 ◽  
Vol 5 (10) ◽  
pp. eaax3084 ◽  
Author(s):  
Liqiang Ren ◽  
Nitesh Nama ◽  
Jeffrey M. McNeill ◽  
Fernando Soto ◽  
Zhifei Yan ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
Chemical Engineering ◽  
Acoustic Pressure ◽  
Ultrasonic Transducer ◽  
Acoustic Streaming ◽  
Three Dimensional ◽  
Three Dimensions ◽  
Propulsive Force ◽  
Particle Manipulation ◽  
Bjerknes Force

The ability to precisely maneuver micro/nano objects in fluids in a contactless, biocompatible manner can enable innovative technologies and may have far-reaching impact in fields such as biology, chemical engineering, and nanotechnology. Here, we report a design for acoustically powered bubble-based microswimmers that are capable of autonomous motion in three dimensions and selectively transporting individual synthetic colloids and mammalian cells in a crowded group without labeling, surface modification, or effect on nearby objects. In contrast to previously reported microswimmers, their motion does not require operation at acoustic pressure nodes, enabling propulsion at low power and far from an ultrasonic transducer. In a megahertz acoustic field, the microswimmers are subject to two predominant forces: the secondary Bjerknes force and a locally generated acoustic streaming propulsive force. The combination of these two forces enables the microswimmers to independently swim on three dimensional boundaries or in free space under magnetical steering.

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