A passive cavitation detector (PCD) identifies cavitation events by sensing acoustic emissions generated by the collapse of bubbles. In this work, a dual passive cavitation detector (dual PCD), consisting of a pair of orthogonal confocal receivers, is described for use in shock wave lithotripsy. Cavitation events are detected by both receivers and can be localized to within 5 mm by the nature o...

Beer tapping is a well known prank where a bottle of beer is impacted from the top by a solid object, usually another bottle, leading to a sudden foam overflow. A description of the shock-driven bubble dynamics leading to foaming is presented based on an experimental and numerical study evoking the following physical picture. First, the solid impact produces a sudden downwards acceleration of t...

Gas-encapsulated droplets have recently been promoted as an effective technique for fluid transport. Shock waves are herein proposed instant release mechanism the encapsulated fluid, which subsequently discharges into surroundings. This process relies on intricate bubble dynamics and droplet response to shock driving, discovered through numerical theoretical investigations. The key factors invo...

Recent observations have revealed a superbubble associated with the young stellar cluster OCl 352 near the W4 H II region: a void in H I emission (Normandeau, Taylor, & Dewdney), and a bright shell in Hα emission (Dennison, Topasna, & Simonetti). We investigate the hypothesis that the bubble is blown by stellar winds from the O-type stars in the association. The Kompaneets approximation is adap...

Phase change through boiling is used in a variety of heat-transfer and chemical reaction applications. The state of the art in nucleate boiling has focused on increasing the density of bubble nucleation using porous structures and microchannels with characteristic sizes of tens of micrometers. Traditionally, it is thought that nanoscale surfaces will not improve boiling heat transfer, since the...

In this paper, a Lagrangian particle method is proposed for the simulation of multiphase flows with surfactant. The model is based on the multi-phase smoothed particle hydrodynamics (SPH) framework of Hu and Adams [1]. Surfaceactive agents (surfactants) are incorporated into our method by a scalar quantity describing the local concentration of molecules in the bulk phase and on the interface. T...

Using molecular dynamics, we study the nucleation and stability of bulk nanobubble clusters. We study the formation, growth, and final size of bulk nanobubbles. We find that, as long as the bubble-bubble interspacing is small enough, bulk nanobubbles are stable against dissolution. Simple diffusion calculations provide an excellent match with the simulation results, giving insight into the reas...

John Woods defined the epistemic bubble as the inescapable state of first-person human rationality. In this paper we will propose, at a seminal level, how the fertility of such approach can be expanded beyond the logical-epistemic dimension: the emotional sphere as well seems to be deeply affected by selfimmunization dynamics so that the cognitive bubble – rather than just epistemic – could def...