Engineering analyses combined with experimental observations in horizontal tubular photobioreactors and vertical bubble columns are used to demonstrate the potential of pneumatically mixed vertical devices for large-scale outdoor culture of photosynthetic microorganisms. Whereas the horizontal tubular systems have been extensively investigated, their scalability is limited. Horizontal tubular p...

The 1999 eruption of Shishaldin volcano (Alaska, USA) displayed both Strombolian and Subplinian basaltic activity. The Subplinian phase was preceded by a signal of low amplitude and constant frequency (c2 Hz) lasting 13 h. This bhumming signalQ is interpreted as the coalescence of the very shallow part of a foam building up in the conduit, which produces large gas bubbles before bursting. The a...

The dynamics of a water jet on a flat free surface are investigated using a nanosecond pulsed laser for creating an oscillating bubble with different depths beneath the free surface. A thin jet is shown to deform a crater surface resulted from surface depression and cause a circular ring-shaped crater on the connection surface between the crater of surface depression and the thin jet. The colla...

OBJECTIVES This study compared a new transthoracic echocardiographic (TTE) method for detection of right to left bubble passage, transmitral Doppler (TMD), against two-dimensional (2D) TTE contrast study and the gold standard, of transesophageal echocardiography (TEE), and assessed its utility in quantitative assessment of patent foramen ovales (PFO). BACKGROUND Current TTE methods are relati...

In bubble-laden flows with large local or global void fraction the distance between bubbles is small so that these interact with a certain probability. During interaction, the bubble can either bounce or undergo coalescence, depending on the nature of the interaction. Coalescence as well as bubble breakup alter the bubble size distribution and consequently change the dynamics of individual bubb...

In the present study the bubble behavior in the narrow space are experimentally and numerically examined as the gap between two parallel walls and the position of bubble induction were changed. The main results are as follows. (1) The effects of two parallel walls can be classified by the ratio of the gap between the walls to the maximum bubble radius. If the ratio>5.0 the bubble shape is almos...

In this paper, effects of EHD actuators on hydrodynamic behavior and heat transfer of air flow over a circular cylinder were considered. Pressure and temperature distributions around the cylinder were measured in presence of wire-plate EHD actuators. The Reynolds number based on cylinder diameter (d) were 3500, 7000. Experiments were performed for various configurations. Based on obtained resul...

BACKGROUND The mechanics of gas embolism bubble adhesion to the vessel wall is poorly understood. New strategies to treat gas embolism may result from an understanding of adhesion forces, including the molecular determinants of bubble adhesion. The authors conducted experiments to measure the adhesion force of bubbles contacting the vessel wall. METHODS Microbubbles were injected into excised...

1 Modeling bubble-vortex interactions Simulations of bubble entrainment and interactions with two dimensional vorti-cal flows are preformed using a Discrete Element Model (DEM). In this Eulerian-Lagrangian approach, solution to the carrier phase is obtained using direct numerical simulation whereas motion of subgrid bubbles is modeled using Lagrangian tracking. The volumetric displacement of th...