We present three-dimensional particle-in-cell (3D-PIC) simulations of laser wake field acceleration (LWFA) of electrons in the bubble regime, using the code ILLUMINATION. The study is motivated by the new Light Wave Synthesizer (LWS), currently under construction at Max-Planck-Institut für Quantenoptik (MPQ), which is expected to produce short (sub-10 fs), high power (multi-terawatt) laser puls...

Since the mean characteristic of nucleate boiling is bubble formation and collapse near the heating surface, in this study attempts have been made to investigate heat transfer effects due to the bubbles ebullition and collapse cycle. All possible heat transfer mechanisms are studied qualitatively and quantitatively. For quantitative calculation of the heat transfer portion by each of the introd...

When a bubble collapses mildly the interior pressure field is spatially uniform; this is an assumption often made to close the Rayleigh–Plesset equation of bubble dynamics. The present work is a study of the self-consistency of this assumption, particularly in the case of violent collapses. To begin, an approximation is developed for a spatially non-uniform pressure field, which in a violent co...

A nonbarotropic continuum bubbly mixture model is used to study the one-dimensional cavitatingjow through a converging-diverging nozzle. The nonlinear dynamics of the cavitation bubbles are modeled by the Rayleigh-Plesset equation. Analytical results show that the bubble/bubble interaction through the hydrodynamics of the surrounding liquid has important effects on this conjined JEow jield. One...

We introduce a simple generalization of rational bubble models which removes the fundamental problem discovered by [20] that the distribution of returns is a power law with exponent less than 1, in contradiction with empirical data. The idea is that the price fluctuations associated with bubbles must on average grow with the mean market return r. When r is larger than the discount rate rδ , the...

The dynamics of magnetic bubble solitons in a two-dimensional isotropic antiferromagnetic spin lattice is studied, in the case where the exchange integral J(x, y) is position dependent. In the near continuum regime, this system is described by the relativistic O(3) sigma model on a spacetime with a spatially inhomogeneous metric, determined by J . The geodesic approximation is used to describe ...

We investigate baryogenesis at a first order electroweak phase transition in the presence of a CP violating condensate on the bubble walls, in the regime in which the bubble walls are ‘thick’, in the sense that fermions interact with the plasma many times as the bubble wall passes. Such a condensate is present in multi-Higgs extensions of the standard model and may be formed via an instability ...

The distribution of bubble lengths in double-stranded DNA is presented for segments of varying guanine-cytosine (GC) content, obtained with Monte Carlo simulations using the Peyrard-Bishop-Dauxois model at 310 K. An analytical description of the obtained distribution in the whole regime investigated, i.e., up to bubble widths of the order of tens of nanometers, is available. We find that the de...

We consider vapor bubbles in microchannels in which the vapor is produced by a heater element and condenses in cooler parts of the interface. The free boundary problem is formulated for a long steady-state bubble in a rectangular channel with a heated bottom. Lubrication-type equations are derived for the shape of the liquid-vapor interface in a cross-sectional plane and in the regime for which...

In process industries, the measurement of void fraction is considerably important for sustainable operations. The erroneous calculation of void fraction is inevitably be the cause of many industrial accidents such as loss of coolant accidents in reactor operations, sweet corrosions in sub-sea oil and gas pipelines and an in-efficient process control of chemical plants. Keeping in view the impor...