Introduction Within an ion channel lower speed positive ions are stopped a reversed by the repelling electric field as soon as internal voltage goes positive. A typical potential barrier approaches +40 mV; assuming a 4 nm long channel this amounts to +10 megavolts per meter (MeV/m) which is very high indeed, higher than the field for lightening in the sky. Reversed ions drift back to where they...

We measure near-field radiative cooling of a thermally isolated nanostructure up to a few degrees and show that in principle this process can efficiently cool down localized hotspots by tens of degrees at submicrometer gaps. This process of cooling is achieved without any physical contact, in contrast to heat transfer through conduction, thus enabling novel cooling capabilities. We show that th...

In this work we study the energy exchange between an atomic system and a thermal radiation field, using the Dalibard, Dupont-Roc and Cohen-Tannoudji (DDC) construct, incorporating temperature effects to the eigenstates of the radiation field operator through the electromagnetic propagator of Thermo Field Dynamics in the Coulomb gauge. We also discuss the stability of the atomic system at finite...

The S-N discrete ordinates (DO) method is developed for the first time to solve transient radiative heat transfer in a two-dimensional rectangular enclosure with absorbing, emitting, and anisotropically scattering medium subject to diffuse and/or collimated laser irradiation. The transient DO method is used to solve several example problems and compared with the existing results and the Monte C...

Solutions of the diffusion approximation to the radiative transport equation are derived for a turbid (rectangular) parallelepiped using the method of image sources and applying extrapolated boundary conditions. The derived solutions are compared with Monte Carlo simulations in the steady-state and time domains. It is found that the diffusion theory is in good agreement with Monte Carlo simulat...

We study the Schwinger pair production in confining theories. The production rate in an external electric field E is numerically evaluated by using the holographic description. There exist two kinds of critical values of the electric field: (i) E = Ec , above which there is no potential barrier and particles are freely generated, and (ii) E = Es , below which the confining string tension domina...