Cryogen spray cooling (CSC) is used to protect the epidermis during dermatologic laser surgery. To date, the relative influence of the fundamental spray parameters on surface cooling remains incompletely understood. This study explores the effects of mass flow rate and average droplet velocity on the surface heat flux during CSC. It is shown that the effect of mass flow rate on the surface heat...

The way the arrangement of small conductors of ionic current on biological membranes regulates flux is an open physical question. We study this problem by a model of diffusion through a cluster of channels in an impermeable biological cell membrane. We show that the flux depends on the relative distance between the channels and show that moving two contiguous channels apart may increase the flu...

Two-dimensional numerical simulations are used to examine the vorticity flux and slot entrance effects in zero-net mass-flux devices. The simulations allow us to extract a simple scaling law for the vorticity flux which provides insight into the relative importance of the various operational parameters. In addition to this, a semi-analytical model is proposed in order to determine the pressure ...

We collect and combine all published data on the vertical atmospheric muon flux and the muon charge ratio for muon momenta above 10 GeV. At sea level the world average of the momentum spectra agrees with the flux calculated by E.V. Bugaev et al. within 15 %. The observed shape of the differential flux versus momentum is slightly flatter than predicted in this calculation. The experimental accur...

A possible mechanism of the macroturbulence instability observed in fluxline systems during remagnetization of superconductors is proposed. It is shown that when a region with flux is invaded by antiflux the interface can become unstable if there is a relative tangential flux motion. This condition occurs at the interface owing to the anisotropy of the viscous motion of vortices. The phenomenon...

Physikalisch-Technische Bundesanstalt, Abteilung Optik, Photometrie, Postfach 33 45, 38023 Braunschweig, Germany A trilateral intercomparison of photometric units between NIST (USA), NPL (UK), and PTB (Germany) has been conducted to update the knowledge of the relationship between the photometric units disseminated in the three countries. The luminous intensity unit (cd), the luminous responsiv...

13C has become an important tracer isotope for studies of intermediary metabolism. Information about relative flux through pathways is encoded by the distribution of 13C isotopomers in an intermediate pool such as glutamate. This information is commonly decoded either by mass spectrometry or by measuring relative multiplet areas in a 13C NMR spectrum. We demonstrate here that groups of glutamat...