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 ...

We report an experimental and theoretical study of two most critical yet still to-be-answered issues in dispensing-based nanoimprint lithography (D-NIL): air bubble formation and absorption, and discuss their impact on NIL yield and throughput. Using real-time observation via video, we found two different mechanisms for air bubble formation (feature pinning and multi-droplet encircling), and st...

We investigate several means of coupling between a sonoluminescing bubble and an applied magnetic field. Recent experiments show a strong quadratic dependence between the forcing pressures required for stable sonolumines-cence and magnetic field amplitude. However, all coupling mechanisms calculated here are at most one percent perturbations. The most likely explanation is a sensitive hydrodyna...

A new type of apparatus for the production of single bubbles of adjustable size is presented. A single bubble is generated by injecting a short burst of gas into a liquid channel flow. The radius of the bubble can be varied continuously from 300 mm up to a 3 mm by adjusting the timing of a valve injecting the gas. The device works also in liquids with variable pressure and can be microcomputer ...

∇·u=0 Here is the temperature, u=(u1; u2) is the velocity, p is the pressure. In Reference [1], Pumir and Siggia observed that the cap of a symmetric rising bubble collapses in a nite time. In contrast, E and Shu [2] reported that the motion of the bubble cap is a very unlikely candidate for nite time singularity formation. In this paper, we prove the global regularity for the viscous Boussines...

Mechanisms and dynamics of bubble coalescence in silicic magmas 1 Jonathan M. Castro (University of Mainz) 2 Alain Burgisser (ISTO-CNRS) 3 Ian Schipper (ISTO-CNRS) 4 Simona Mancini (ISTO-Université d’Orléans) 5 6 Abstract 7 Bubble coalescence is an important process that strongly affects magmatic degassing. 8 Without coalescence, bubbles remain isolated from one another in the melt, severely 9 ...

Hydrodynamic simulations of a collapsing bubble show that pure D, cannot exhibit picosecond sonoluminescence, because of its large sound speed. The addition of D,O vapor lowers the sound speed and produces calculated results consistent with experiments. A pressure spike added to the periodic driving amplitude creates temperatures that may be sufficient to generate a very small number of thermon...

In preterm infants with respiratory distress syndrome (RDS), the application of continuous positive airway pressure (CPAP) is associated with benefits in terms of reduced respiratory failure and reduced mortality. We conducted this prospective study to evaluate the effectiveness of bubble-CPAP as primary mode of respiratory support. Bubble CPAP was found to be safe and effective means of treati...

The primary goal of this study was to evaluate a new device and system, designed to optimize the performance of standard low pressure air diffusers in two types of aerated systems (activated sludge and aerobic sludge digestion) and to decrease overall energy consumption. Aerated treatment systems are very important in the treatment of wastewaters and management of sludges. The activated sludge ...

At low Reynolds numbers, laminar-turbulent transition occurs on the suction side of high-lift low-pressure turbine blades. The prediction of this flow is an important step in low-pressure turbine design. Thus the laminar-turbulent transition must be modeled or resolved. The flow around the high-lift low-pressure turbine blade T106C is predicted using RANS simulations, without and with transitio...