In the second type (Fig. 5), liquid slugs are separated by discrete gas bubbles generated at the T-junction of microfluidic channels.
For the camera images, pulse trains at 5 kHz were applied to use subsequent pulses to illuminate the preceding event, specifically by scattering and reflection at the gas bubbles generated in water.
We found that having the interval (between pulses) at 9.97 s was necessary to allow enough time for gas bubbles generated at the electrodes to dissipate through PDMS.
Cavitation (volume oscillations and collapse of gas bubbles), as generated by a co-administration of shockwaves (SW) and microbubbles (SWB), induces cytotoxicity in vitro.
With increasing gas volume flow rates larger bubbles are generated by bubble coalescence, which further leads to transition to slug, churn-turbulent, and annular flow.
Additionally, video images were acquired from the focal site where gas bubbles are generated in water.
Here, tensile stress can reduce the vaporization energy [ 7, 36] and gas bubble generation is supported by rectified diffusion in oscillating transient bubbles [ 7, 37].
Usually this influence is attributed to the gas momentum force, generated by gas flowing into the bubble during its formaiton.
H2Te3 gas generated by the addition of 3 ml of 0.5 M H2SO4 to Al2Te3, was bubbled through the solution for ∼5 min. The solution turned orange in color due to the formation of the CdTe precursors.
Although the authors of these early papers supposed that the bubbles were produced by thermal expansion of the liquid to gas, we now know that the droplets in EchoGen are fairly stable at 37°, and most, if not all, of the bubbles were generated by the excitation by the applied ultrasonic imaging pulses.
