The U.S. retail payments system in transition : Federal Reserve initiatives

This article explores the changing landscape of U.S. retail payments: trends, the Fed's role, and the future of payments.Payment systems ; Federal Reserve System

Comparative study of patients knowledge on osteoarthritis treatment options to ACR guidelines

Portuguese population is growing older, according to national data in 2011 the aging index was 129. The number of elderly population is higher than the younger; average life expectancy is 79,2 years (1). Because knee Osteoarthritis increases with age, and according to WHO 80% of these subjects will have some degree of impairment and 25% will not be able to do their daily living activities (2), OA has a big impact on the sustainability of both health and social care as populations grow older. Our goal was to compare current guidelines of managing knee OA, to the degree of information each patient has about their treatment options.info:eu-repo/semantics/publishedVersio

Infinite impulse response modal filtering in visible adaptive optics

Diffraction limited resolution adaptive optics (AO) correction in visible wavelengths requires a high performance control. In this paper we investigate infinite impulse response filters that optimize the wavefront correction: we tested these algorithms through full numerical simulations of a single-conjugate AO system comprising an adaptive secondary mirror with 1127 actuators and a pyramid wavefront sensor (WFS). The actual practicability of the algorithms depends on both robustness and knowledge of the real system: errors in the system model may even worsen the performance. In particular we checked the robustness of the algorithms in different conditions, proving that the proposed method can reject both disturbance and calibration errors

Three-dimensional Dirac oscillator in a thermal bath

The thermal properties of the three-dimensional Dirac oscillator are considered. The canonical partition function is determined, and the high-temperature limit is assessed. The degeneracy of energy levels and their physical implications on the main thermodynamic functions are analyzed, revealing that these functions assume values greater than the one-dimensional case. So that at high temperatures, the limit value of the specific heat is three times bigger.Comment: 9 pages, 4 figures. Text improved, references added. Revised to match accepted version in Europhysics Letters

Electronic transport through bilayer graphene flakes

We investigate the electronic transport properties of a bilayer graphene flake contacted by two monolayer nanoribbons. Such a finite-size bilayer flake can be built by overlapping two semiinfinite ribbons or by depositing a monolayer flake onto an infinite nanoribbon. These two structures have a complementary behavior, that we study and analyze by means of a tight-binding method and a continuum Dirac model. We have found that for certain energy ranges and geometries, the conductance of these systems oscillates markedly between zero and the maximum value of the conductance, allowing for the design of electromechanical switches. Our understanding of the electronic transmission through bilayer flakes may provide a way to measure the interlayer hopping in bilayer graphene.Comment: 11 pages, 8 figure