Incoherent Mollow triplet

A counterpart of the Mollow triplet (luminescence lineshape of a two-level system under coherent excitation) is obtained for the case of incoherent excitation in a cavity. Its analytical expression, in excellent agreement with numerical results, pinpoints analogies and differences between the conventional resonance fluorescence spectrum and its cavity QED analogue under incoherent excitation.Comment: 4 pages, 3 figure

The Effects of Inlet Flow Modification on Cavitating Inducer Performance

This paper explores the effect of inlet flow modification on the cavitating and noncavitating performance of two cavitating inducers, one of simple helical design and the other a model of the low-pressure LOX pump in the Space Shuttle Main Engine. The modifications were generated by sections of honeycomb, both uniform and nonuniform. Significant improvement in the performance over a wide range of flow coefficients resulted from the use of either honeycomb section. Measurements of the axial and swirl velocity profiles of the flows entering the inducers were made in order to try to understand the nature of the inlet flow and the manner in which it is modified by the honeycomb sections

A magnetic reconnection model for explaining the multi-wavelength emission of the microquasars Cyg X-1 and Cyg X-3

Recent studies have indicated that cosmic ray acceleration by a first-order Fermi process in magnetic reconnection current sheets can be efficient enough in the surrounds of compact sources. In this work, we discuss this acceleration mechanism operating in the core region of galactic black hole binaries (or microquasars) and show the conditions under which this can be more efficient than shock acceleration. In addition, we compare the corresponding acceleration rate with the relevant radiative loss rates obtaining the possible energy cut-off of the accelerated particles and also compute the expected spectral energy distribution (SED) for two sources of this class, namely Cygnus X-1 and Cygnus X-3, considering both leptonic and hadronic processes. The derived SEDs are comparable to the observed ones in the low and high energy ranges. Our results suggest that hadronic non-thermal emission due to photo-meson production may produce the very high energy gamma-rays in these microquasars.Comment: 17 pages and 7 figures. Accepted for publication in the Monthly Notices of the Royal Astronomical Society (MNRAS

Experimental and computational study of the effect of temperature on the electro-polymerization process of Thiophene

Temperature effect on the nucleation and growth mechanisms (NGM) of poly(thiophene) (PTh) was investigated through experimental and computational tools. The computational simulation method was based on a kinetic Monte Carlo algorithm. It reproduced key processes such as diffusion, oligomerization, and the precipitation of oligomers onto the electrode surface. Electrochemical synthesis conditions at temperatures between 263 and 303 K were optimized. The deconvolution of the i-t transients reflected two contributions: a progressive nucleation with three-dimensional growth controlled by diffusion and the other by charge transfer, PN3Ddif and PN3Dct, respectively. As temperature decreased, a diminution of the charge associated to each contribution was observed and the nucleation induction time increased. Experimental and computational evidence indicated that temperature does not change the nucleation and growth mechanism (NGM). This effect was ascribed to kinetic factors rather than to film conductivity. This work contrasts simulation and experimental evidence and demonstrates how computational simulations can help to understand the electrochemical process of conducting polymers formation.Fil: Camarada, María Belén. Pontificia Universidad Católica de Chile; Chile. Universidad de Talca; ChileFil: Romero, M.. Pontificia Universidad Católica de Chile; ChileFil: Gimenez, Maria Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; ArgentinaFil: Schmickler, Wolfgang. Universitat Ulm; AlemaniaFil: del Valle, M. A.. Pontificia Universidad Católica de Chile; Chil