This paper compares two physical mechanisms for the collapse of a bubble near a rigid wall: a traveling shock-induced collapse and a Rayleigh-like collapse due to a uniform rise of the pressure around the bubble. A multi-material compressible flow solver capable of handling material interfaces under high pressures is used to investigate these two scenarios for different levels of the driving pr...

We discuss the space-time structure for the process of decay of a bubble of hypothetic phase – disoriented chiral condensate (DCC). The evolution of initial classical field configuration corresponding to the bubble of DCC is studied both numerically and analytically. The process of decay of this initial configuration depends crucially on selfinteraction of the pionic fields. It is shown that in...

We calculate analytically the bubble nucleation rate in a model of rst order in ation which is able to produce large scale structure. The computation includes the rst-order departure from the thin-wall limit, the explicit derivation of the pre-exponential factor, and the gravitational correction. The resulting bubble spectrum is then compared with constraints from the large scale structure and ...

in this research, the effect of bubble surface area flux, sb, and particle size on flotation rate constant, k, of pyrite (fes2) particles was studied using bubble-particle interactions. the bubble-particle collision, attachment and detachment efficiencies were calculated under different flow regimes. the k increased with increase in the collision efficiency and decrease in the detachment effici...

BACKGROUND Surfactants may reduce the adhesion force holding bubbles to the vessel wall in gas embolism. The authors measured bubble adhesion force using excised microvessels. They assessed endothelial damage by measuring vessel reactivity and with microscopy. METHODS Microbubbles injected into arterioles resided for 5, 10, or 30 min, with intact or damaged endothelium. Perfusion was with rat...

We perform a characterization of a recently reported microbubble injector in conditions relevant to microgravity. Injection of bubbles is based on the generation of a slug flow in a capillary T-junction, whose operation is robust to changes in the gravity level. We address questions regarding the performance under different working regimes. In particular, we focus on the regimes found within a ...

Fluidized beds are widely used in industrial operations due to their ability to give good mixing and a high contact area between the phases. The excellent controlling ability of temperature allows good operating conditions for solid catalyzed gas phase reactions and also the ease of the design. Powders used in industrial ‡uidized beds have a particle size distribution, and the particle size dis...

[1] We have modeled the nucleation and isothermal growth of bubbles in dacite from the 1912 Plinian eruption of Novarupta, Alaska. Bubble growth calculations account for the exsolution of H2O and CO2, beginning with bubble nucleation and ending when bubble sizes reproduced the observed size distribution of vesicles in Novarupta pumice clasts. Assuming classical nucleation theory, bubbles nuclea...

Experiments were conducted in a 0.25 m diameter bubble column to investigate the effect of animal cell culture medium composition on oxygen transfer rate. Air is used as the dispersed phase. The gas superficial velocity is varied between 0.4 and 2 cm/s (aeration rate ranging between 0.05 and 0.25 vvm) and the bubble column is thus operated in the homogenous regime. Aqueous solutions the composi...