Collective spontaneous emission of two entangled atoms near an oscillating mirror
We consider the cooperative spontaneous emission of a system of two identical atoms, interacting with the electromagnetic field in the vacuum state and in the presence of an oscillating mirror. We assume that the two atoms, one in the ground state and the other in the excited state, are prepared in a correlated (symmetric or antisymmetric) {\em Bell}-type state. We also suppose that the perfectly reflecting plate oscillates adiabatically, with the field modes satisfying the boundary conditions at the mirror surface at any given instant, so that the time-dependence of the interaction Hamiltonian is entirely enclosed in the instantaneous atoms-wall distance. Using time-dependent perturbation …
A new tool for the assessment of severe anthropogenic eutrophication in small shallow water bodies
Abstract Unlike in deep stratified lakes, the assessment of eutrophication in shallow aquatic systems (i.e., wetlands, marshes, ponds) should be based on the interaction between water and sediment. The availability of P to primary producers is naturally higher in shallow systems, because the sediment plays an active part via adsorption, precipitation and release processes. Thus, many wetlands in protected areas are naturally eutrophic and have a high trophic status due to intrinsic features and thus, display a high concentration of total-P in the water without necessarily implying pollution or poor quality. We have provided a diagnostic tool based on the chemical equilibrium of dissolved re…