I wish to offer an alternative theory for the temporary paraplegia referenced in the letter to the editor rather than that of air entrapment. (Dalmau-Carola J. An old complication of a new technique: Pneumorrhachis from caudal epidural pulsed radiofrequency. Pain Physician: November/December 2014; 17:E783-E806). A 70-year-old woman with chronic lower back pain radiating to the left lower extrem...

Air-water flow measurements were conducted in two large-size stepped chute facilities (θ = 3.4 & 16o) to study experimental distortion caused by scale effects and result extrapolation to prototypes. The stepped geometries corresponded to moderate slopes typical of embankment dams and storm waterways. Experimental data included distributions of air concentration, air-water flow velocity, bubble ...

The atomic force microscope was employed to investigate the time effect on normal interactions between a hydrophilic silica particle and an air bubble deposited onto a hydrophobic Teflon surface in pure water and 10 mM methyl isobutyl carbinol solutions. The force versus separation distance curves taken at different times after bubble generation were qualitatively compared. It has been found th...

Bursting of bubbles at an air/liquid interface is a familiar occurrence relevant to foam stability, cell cultures in bioreactors and ocean–atmosphere mass transfer. In the latter case, bubble-bursting leads to the dispersal of sea-water aerosols in the surrounding air. Here we show that bubbles bursting at a compound air/oil/water-with-surfactant interface can disperse submicrometre oil droplet...

We studied experimentally the dependence of light emission and phase space boundaries of air bubbles in water on the level of degassing down to low partial pressures of 15 mmHg. We found that the maximum obtainable light intensity increased monotonically by lowering the concentration of dissolved air in water. We also present a new technique to obtain the acoustic pressure (P(a)) and ambient ra...

Air bubbles in working oil influence stiffness and efficiency of hydraulic systems, thus it is important for technical issues to eliminate the air bubbles actively from the hydraulic oil. Bubble eliminator is a device that removes air bubbles by using a swirling flow. In this paper, we investigate flow behavior in the bubble eliminator by means of laboratory experiments with a transparent bubbl...

A two-dimensional air-fluidized bed of 600 mm width and 1000 mm height was studied to investigate the formation, rise and cracking process of a bubble. The particles were assumed to be regular round particles of diameter 4 mm. The RNG k-ε model was employed for the turbulence, and the time integration scheme is the first order implicit difference with the time-step 0.0001 s. The equations were ...

Very fine sand is prepared in a well-defined and fully decompactified state by letting gas bubble through it. After turning off the gas stream, a steel ball is dropped on the sand. On impact of the ball, sand is blown away in all directions ("splash") and an impact crater forms. When this cavity collapses, a granular jet emerges and is driven straight into the air. A second jet goes downwards i...

As air is injected into a flowing liquid, the resultant bubble characteristics depend on the properties of the injector, near-wall flow, and flowing liquid. Previous research has shown that near-wall bubbles can significantly reduce skin-friction drag. Air was injected into the turbulent boundary layer on a test section wall of a water tunnel containing various concentrations of salt and surfac...

Reliable long-term cell culture in microfluidic system is limited by air bubble formation and accumulation. In this study, we developed a bubble removal system capable of both trapping and discharging air bubbles in a consistent and reliable manner. Combined with PDMS (Polydimethylsiloxane) hydrophilic surface treatment and vacuum filling, a microfluidic perifusion system equipped with the bubb...