Caracterización de nitratos alcalinos y alcalinoterreos por espectroscopia vibracional Characterization of alkali-metal and alkaline-earth nitrates by vibrational spectroscopy

[EN] Infrared spectra of sodium and potassium alkaline-metal nitrates and magnesium and calcium alkali-earth nitrates in solid phase had been recorded in order to assign the fundamental bands. The influence of the dispersal médium (alkaline halide), employed in the solid sample preparation have been discussed. The quantitative measurements of the band in ten sities at 1.387 cm~^ (present in the I.R. spectra of the four nitrates in KBr médium) allowed us to determine the Lambert-Beer law slopes for each compound. These valúes are differents (bearing in mind experimental random errors), so we have could to affirm the nonexistence of solid solution between the nitrate and the alkaline halide médium. The L-B law obtained by us can be used for the Identification differentiation and quantitative analysis of these nitrates in solid phase, even if they are present in a very low concentration.[ES] Se ha realizado la asignación de los espectros infrarrojo (IR) de los nitratos alcalinos, sódico y potásico, y de los alcalinoterreos, magnésico y calcico, en estado sólido. Se ha visto la influencia del medio dispersante (haluro alcalino), utilizado en la preparación de la muestra sólida. El estudio cuantitativo de la absorbancia de la banda a 1.387 cm~^ (presente en los espectros IR de los cuatro nitratos en medio KBr) permite determinar las pendientes de la Ley de Lambert-Beer Se comprueba que dichas pendientes son diferentes lo que conduce a poder afirmar que no se produce disolución sólida entre el KBr y el nitrato alcalino o alcalinotérreo. La determinación de la ley de Lambert-Beer permite la identificación y el análisis cualitativo y cuantitativo por espectroscopia IR de estos nitratos cuando están presentes en bajas concentraciones en muestras sólidas.Peer reviewe

Caracterización de nitratos alcalinos y alcalinotérreos por espectroscopía vibracional

Infrared spectra of sodium and potassium alkaline-metal nitrates and magnesium and calcium alkali-earth nitrates in solid phase had been recorded in order to assign the fundamental bands. The influence of the dispersal médium (alkaline halide), employed in the solid sample preparation have been discussed. The quantitative measurements of the band in ten sities at 1387 cm-1 (present in the I.R. spectra of the four nitrates in KBr médium) allowed us to determine the Lambert-Beer law slopes for each compound. These values are differents (bearing in mind experimental random errors), so we have could to affirm the nonexistence of solid solution between the nitrate and the alkaline halide médium. The L-B law obtained by us can be used for the Identification differentiation and quantitative analysis of these nitrates in solid phase, even if they are present in a very low concentration.Se ha realizado la asignación de los espectros infrarrojo (IR) de los nitratos alcalinos, sódico y potásico, y de los alcalinotérreos, magnésico y cálcico, en estado sólido. Se ha visto la influencia del medio dispersante (haluro alcalino), utilizado en la preparación de la muestra sólida. El estudio cuantitativo de la absorbencia de la banda a 1.387 cm-1 (presente en los espectros IR de los cuatro nitratos en medio KBr) permite determinar las pendientes de la Ley de Lambert-Beer Se comprueba que dichas pendientes son diferentes lo que conduce a poder afirmar que no se produce disolución sólida entre el KBr y el nitrato alcalino o alcalinotérreo. La determinación de la ley de Lambert-Beer permite la identificación y el análisis cualitativo y cuantitativo por espectroscopia IR de estos nitratos cuando están presentes en bajas concentraciones en muestras sólidas

Estudio de una comunidad tabaquera de Villa González, Santiago

Versión prelimina

Estudio de una comunidad tabaquera de Villa González, Santiago

Versión prelimina

Conductivity and long term stability of polypyrrole poly(styrene-co- methacrylic acid) core-shell particles at different polypyrrole loadings

Conductive core–shell particles were obtained by chemical polymerization of pyrrole over monodisperse poly(styrene-co-methacrylic acid) particles. The surface composition has been studied by elemental analysis, Fourier Transform Infrared Spectroscopy (FTIR), X-ray Photoelectron Spectroscopy (XPS), scanning electron microscopy and transmission electron microscopy techniques. XPS, elemental analysis and FTIR results allowed determining doping level and conjugation length of the polypyrrole (PPy) chain deposited on the latex surface. It is shown that the chain conjugation length, and not the doping level, is the principal factor that influences the conductivity. Samples with low PPy loading have short conjugation length and so low conductivity independently of their doping level. The experimental conductivity decay with time has been analysed following the electron hopping model, from this model the characteristic time (τ) of the conductivity degradation process has been determined.The financial support by the Ministerio de Educación y Ciencia (Spain), MAT 2007-65711-C04-02 is also gratefully appreciated.Peer Reviewe

Getting prepared for the LHC Run2: the PIC Tier-1 case

The Large Hadron Collider (LHC) experiments will collect unprecedented data volumes in the next Physics run, with high pile-up collisions resulting in events that require a complex processing. Hence, the collaborations have been required to update their Computing Models to optimize the use of the available resources and control the growth of resources, in the midst of widespread funding restrictions, without penalizing any of the Physics objectives. The changes in computing for Run2 represent significant efforts for the collaborations, as well as significant repercussions on how the WLCG sites are built and operated.This paper focuses on these changes, and how they have been implemented and integrated in the Spanish WLCG Tier-1 centre at Port d'Informació Cientifica (PIC), which serves the ATLAS, CMS and LHCb experiments. The approach to adapt a multi-VO site to the new requirements, while maintaining top reliability levels for all the experiments, is as well presented. Additionally, a description of work done to reduce the operational and maintenance costs of the Spanish Tier-1 centre, in agreement with the expectations from WLCG, is provided

The LHC Tier1 at PIC: experience from first LHC run

This paper summarizes the operational experience of the Tier1 computer center at Port d’InformacióCientífica (PIC) supporting the commissioning and first run (Run1) of the Large Hadron Collider (LHC). Theevolution of the experiment computing models resulting from the higher amounts of data expected after therestart of the LHC are also described