Complete positivity and thermodynamics in a driven open quantum system

While it is well known that complete positivity guarantees the fulfilment of the second law of thermodynamics, its possible violations have never been proposed as a check of the complete positivity of a given open quantum dynamics. We hereby consider an open quantum micro-circuit, effectively describable as a two-level open quantum system, whose asymptotic current might be experimentally accessible. This latter could indeed be used to discriminate between its possible non-completely positive Redfield dynamics and a completely positive one obtained by standard weak-coupling limit techniques, at the same time verifying the fate of the second law of thermodynamics in such a context.Comment: 28 pages, 8 figures, LaTe

A FEW FOR-PROFIT BUSINESSES’ BATTLE OVER THE AFFORDABLE CARE ACT’S PREVENTATIVE SERVICES MANDATE

Under the Patient Protection and Affordable Care Act (ACA), employers are required to provide employees with health plans, which must include FDA, approved contraceptives with no cost sharing. While Health and Humans Services (HHS) revised the regulation to allow for a compromise among religious organizations and non-profits run by religious organizations, private for profit businesses must comply with the ACA even if the business asserts to be founded on religious principles. Several for profit business have sued in district court for an injunction against the requirements. However, a circuit split exists among courts granting preliminary injunctions against the ACA pending a granting of appeal. This note will focus on whether the federal government can compel secular, for profit organizations to provide employee health plans that include contraceptives, the morning after pill and sterilization under the Religious Freedom Restoration Act. Unless the statute or regulation changes, the Supreme Court will likely need to grant certiorari to resolve the issue

Evaluation of nacelle drag using Computational Fluid Dynamics

Thrust and drag components must be defined and properly accounted in order to estimate aircraft performance, and this hard task is particularty essential for propulsion system where drag components are functions of engine operating conditions. The present work describes a numerical method used to calculate the drag in different nacelles, long and short ducted. Two- and three-dimensional calculations were performed, solving the Reynolds Averaged Navier-Stokes (RANS) equations with a commercial Computational Fluid Dynamics (CFD) code. It is then possible to obtain four drag components: wave, induced, viscous and spurious drag using a far-field formulation. An expression in terms of entropy variations was shown and drag for different nacelle geometries was estimated