High-Velocity Estimates and Inverse Scattering for Quantum N-Body Systems with Stark Effect

In an N-body quantum system with a constant electric field, by inverse scattering, we uniquely reconstruct pair potentials, belonging to the optimal class of short-range potentials and long-range potentials, from the high-velocity limit of the Dollard scattering operator. We give a reconstruction formula with an error term.Comment: In this published version we have added remarks and we have edited the pape

Improved wear performance of ultra high molecular weight polyethylene coated with hydrogenated diamond like carbon

Hydrogenated diamond like carbon (DLCH) thin films were deposited on medical grade ultra high molecular weight polyethylene (UHMWPE) by radio frequency plasma enhanced chemical vapor deposition. The DLCH coating thicknesses ranged from 250 to 700. nm. The substrates were disks made of UHMWPEs typically used for soft components in artificial joints, namely virgin GUR 1050 and highly crosslinked (gamma irradiated in air to 100. kGy) UHMWPEs. Mechanical and tribological properties under bovine serum lubrication at body temperature were assessed on coated and uncoated polyethylenes by means of nano-hardness and ball-on-disk tests, respectively. Morphological features of the worn surfaces were obtained by confocal microscopy and scanning electron microscopy. This study confirms an increase in surface hardness and good wear resistance for coated materials after 24. h of sliding test compared to uncoated polyethylene. These results point out that to coat UHMWPE with DLCH films could be a potential method to reduce backside wear in total hip and knee arthroplasties.Ministerio de Ciencia y Educación MAT2006-12603- C02-01, CSD2008-0002

A Declarative Framework for Security: Secure Concurrent Constraint Programming

International audienceDue to technological advances such as the Internet and mobile computing, Security has become a serious challenge involving several disciplines of Computer Science. In recent years, there has been a growing interest in the analysis of security protocols and one promising approach is the development of formalisms that model communicating processes, in particular Process Calculi. The results are so far encouraging although most remains to be done. In this paper we report our observations and preliminary work on CCP as a framework for security protocols

Luttinger liquid superlattices

We calculate the correlation functions and the DC conductivity of Luttinger liquid superlattices, modeled by a repeated pattern of interacting and free Luttinger liquids. In a specific realization, where the interacting subsystem is a Hubbard chain, the system exhibits a rich phase diagram with four different phases: two metals and two compressible insulators. In general, we find that the effective low energy description amalgamates features of both types of liquids in proportion to their spatial extent, suggesting the interesting possibility of `engineered' Luttinger liquids.Comment: RevTeX, 5 pages, 3 figure

2D layered transport properties from topological insulator Bi2_2Se3_3 single crystals and micro flakes

Low-field magnetotransport measurements of topological insulators such as Bi$_2$Se$_3$ are important for revealing the nature of topological surface states by quantum corrections to the conductivity, such as weak-antilocalization. Recently, a rich variety of high-field magnetotransport properties in the regime of high electron densities ($\sim10^{19}$ cm$^{-3}$) were reported, which can be related to additional two-dimensional layered conductivity, hampering the identification of the topological surface states. Here, we report that quantum corrections to the electronic conduction are dominated by the surface states for a semiconducting case, which can be analyzed by the Hikami-Larkin-Nagaoka model for two coupled surfaces in the case of strong spin-orbit interaction. However, in the metallic-like case this analysis fails and additional two-dimensional contributions need to be accounted for. Shubnikov-de Haas oscillations and quantized Hall resistance prove as strong indications for the two-dimensional layered metallic behavior. Temperature-dependent magnetotransport properties of high-quality Bi$_2$Se$_3$ single crystalline exfoliated macro and micro flakes are combined with high resolution transmission electron microscopy and energy-dispersive x-ray spectroscopy, confirming the structure and stoichiometry. Angle-resolved photoemission spectroscopy proves a single-Dirac-cone surface state and a well-defined bulk band gap in topological insulating state. Spatially resolved core-level photoelectron microscopy demonstrates the surface stability.Comment: Sci. Rep. (2016

Digestive alfa-amylases from Tecia solanivora larvae (Lepidoptera: Gelechiidae): response to pH, temperature and plant amylase inhibitors.

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Origen, desarrollo, y descripción de los tipos de gallina "criolla" existentes en varios municipio del valle del cauca

Se plantean argumentos que respaldan la hipótesis de la existencia de la gallina doméstica en América del Sur antes de su descubrimiento. Con el establecimiento de colonias se introdujeron tipos europeos para el consumo de parte de la población. Se explica cómo se generó tecnología apropiada, produciéndose excedentes para exportar antes de 1950. Se comenta el fuerte cambio que sufre la gallina cultura en el Siglo XX con las primeras importaciones, creándose así una dependencia tecnológica. Se describen 11 tipos de gallina "criolla" que existen en el valle del Cauca, y se mencionan algunos ajustes fisiológicos y anatómicos que favorecen un mejor comportamiento de la gallina "criolla"; se discuten y proponen elementos para la creación de un banco de germoplasma con estas aves.There are arguments that favorate the hypotesis that the domestic hen lived in South America before its discovery. There was introduction of European types when the colonies settled. Through apropiate technology there was enough product for exports before 1950. Because of the first imports there was a strong change for the poultry production in the XX Century because of that a technological dependence was introduced. There are 11 diferent types of country hens in the Cauca Valley. Some phisiological and anatomical adjustements help a better development of the country hen in Colombia. This study proposes some elements to create a bank of germplasm with country hens