Sofia Moreno - Academia.edu (original) (raw)

Papers by Sofia Moreno

Conference of the International Speech Communication Association, 1999

Ramón García Gómez (1), Ricardo López Barquilla (1), José Ignacio Puertas Tera (1), José Parera B... more Ramón García Gómez (1), Ricardo López Barquilla (1), José Ignacio Puertas Tera (1), José Parera Bermudez (1), Marie-Christine Haton (2), Jean-Paul Haton (2), Pierre Alinat (4), Sofia Moreno (3), Wolfgang Hess (5), Ma Araceli Sanchez Raya (6), Eduardo Alberto Martínez ...

Introduction: dust mites are an important source of allergens. Barranquilla has the highest preva... more Introduction: dust mites are an important source of allergens. Barranquilla has the highest prevalence of allergic asthma and rhinitis in the Colombian Caribbean, but little is known about these variables in Santa Marta. This is the reason why research was conducted into the prevalence and density of the acari Blomia tropicalis, Dermatophagoides pteronyssinus and Dermatophagoides farinae in Barranquilla and Santa Marta, two cities in Colombia. Objective: gather updated information about house mites associated with allergic respiratory diseases such as asthma and rhinoconjunctivitis in Barranquilla and Santa Marta, where their prevalence is high. Methods: dust samples were collected between May and September 2011. The mites were isolated and identified under the microscope. Total density was expressed as mites per dust gram. Fifty samples were examined in the city of Barranquilla and 52 in Santa Marta. Results: in Barranquilla, the most prevalent species was Blomia tropicalis (92 %),...

Journal of Physics: Condensed Matter, 2021

A scanning multi-crystal x-ray emission spectrometer to perform photon-in/photon-out spectroscopy... more A scanning multi-crystal x-ray emission spectrometer to perform photon-in/photon-out spectroscopy at the I20-Scanning beamline at Diamond Light Source is described. The instrument, equipped with three analyzer crystals, is based on a 1 m Rowland circle spectrometer operating in the vertical plane. The energy resolution of the spectrometer is of the order of 1 eV, having sufficient resolving power to overcome the core-hole lifetime broadening of most of the transition metals K-edges. Examples showing the capability of the beamline for performing high energy resolution fluorescence detection x-ray absorption spectroscopy (HERFD-XAS), non-resonant x-ray emission spectroscopy (XES) and resonant x-ray emission spectroscopy are presented. The comparison of the Zn and Mn K-edge HERFD–XANES of ZnO and MnO with ab initio calculations shows that the technique provides enhanced validation of the models by making subtle spectral features more visible.

CICIMAR Oceánides, 2017

RESUMEN. El estudio de la estructura de comunidades de aves está relacionado con su relevante pap... more RESUMEN. El estudio de la estructura de comunidades de aves está relacionado con su relevante papel en el ecosistema, y cobra mayor importancia cuando se hallan expuestas al daño colateral por actividades antropogénicas. Esta investigación tuvo por objetivo determinar la variación de la estructura en la comunidad de aves en el manglar de El Conchalito, BCS, mediante la aplicación de índices ecológicos como diversidad (H´), dominancia (D) e índice de valor biológico (IVB), durante abril-julio de 2016 en la temporada de transición primavera - verano. Para describir el marco ambiental, se realizaron mediciones de temperatura, nivel de ruido y clorofila a. Igualmente, se utilizaron datos climatológicos. Se registraron 15 especies de aves acuáticas, marinas y/o costeras (5 órdenes, 7 familias y 9 géneros) y 3 especies de aves terrestres (2 órdenes, 2 familias, 3 géneros). Las máximas abundancias de aves se registraron durante los primeros muestreos. La diversidad osciló entre H´= 1.1 y ...

Journal of Synchrotron Radiation, 2018

This issue of the Journal of Synchrotron Radiation is a special issue including papers from the Q... more This issue of the Journal of Synchrotron Radiation is a special issue including papers from the Q2XAFS2017 workshop. Here, a brief introduction is given.

AIP Conference Proceedings, 2016

Dentro del Ecuador existen comunidades indigenas muy poco conocidas, tanto a nivel nacional como ... more Dentro del Ecuador existen comunidades indigenas muy poco conocidas, tanto a nivel nacional como internacional, uno de estos casos es el de la Comunidad Secoya, la misma que debido a falta de vias de comunicacion se ha encontrado aislada, el presente trabajo busca darle un lugar dentro del pais, para este fin se ha realizado un diagnostico global de todos los componentes de la superestructura turistica, que dieron como resultado las falencias y las fortalezas de la comunidad, de aqui se obtuvieron varios microproyectos turisticos de desarrollo comunitario sostenible que serviran para el mejoramiento de la calidad de vida de sus habitantes. La Comunidad Secoya se encuentra ubicada en la provincia de Sucumbios, en el canton Shushufindi, en la parroquia San Roque, en la cuenca del rio Aguarico, politicamente se encuentra dividida en tres centros, Eno, San Pablo y Siecoya Remolino.

AIP Conference Proceedings, 2007

The techniques of energy dispersive EXAFS (EDE), diffuse reflectance Fourier transform infrared s... more The techniques of energy dispersive EXAFS (EDE), diffuse reflectance Fourier transform infrared spectroscopy (DRIFTS) and mass spectrometry (MS) have been combined to study the structure and function of an oxide supported metal catalyst, namely 5 wt% Rh/Al 2 O 3. Using a FreLoN camera as the EDE detector and a rapid-scanning IR spectrometer, experiments could be performed with a repetition rate of 50 ms. The results show that the nature of the rhodium centers is a function of the partial pressures of the reacting gases (CO and NO) and also temperature. This combination of gases oxidizes metallic rhodium particles to Rh(CO) 2 at room temperature. The proportion of the rhodium adopting this site increases as the temperature is raised (up to 450 K). Above that temperature the dicarbonyl decomposes and the metal reclusters. Once this condition is met, catalysis ensues. Gas switching techniques show that at 573 K with NO in excess, the clusters can be oxidized rapidly to afford a linear nitrosyl complex; re-exposure to CO also promotes reclustering and the CO adopts terminal (atop) and bridging (2-fold) sites.

Coordination Chemistry Reviews, 2014

Techniques developed at large scale facilities such as X-ray synchrotrons and pulsed or reactor b... more Techniques developed at large scale facilities such as X-ray synchrotrons and pulsed or reactor based neutron sources have, over the past few decades, played a significant role in unravelling many of the mysteries that underpin the chemical, physical and biochemical properties of ions in solutions. In this presentation we will illustrate how the combination of X-ray diffraction, neutron diffraction and X-ray absorption spectroscopy can be applied to the investigation of the structure of ion hydration shells. Examples of hydration of diand tri-valent ions will be shown. In particular we will present an investigation of the hydration structure of copper (II) ions using this multi-technique approach, and discuss the findings in the context of biological and chemical systems.

International Journal of Molecular Sciences, 2001

Alumina supported CuCl 2 , the basic catalyst for ethylene oxychlorination, has been investigated... more Alumina supported CuCl 2 , the basic catalyst for ethylene oxychlorination, has been investigated by UV-Vis spectroscopy, EPR, EXAFS and XANES in a wide range (0.25-9.0 wt%) of Cu concentration. We have evidenced that, at low Cu content, the formation of a surface aluminate species takes place. The formation of this surface copper aluminate stops at 0.95 wt% Cu / 100 m 2 ; at higher Cu concentrations excess copper chloride precipitates directly from solution during the drying step forming an highly dispersed CuCl 2. H 2 O, phase, overlapping progressively the surface aluminate. Depletion tests and IR spectroscopy of adsorbed NO have demonstrated that the latter is the only active phase. A complete catalytic cycle has then been performed on CuCl 2 /Al 2 O 3 catalyst. EPR, XANES and EXAFS, have been used to demonstrate that the ethylene oxychlorination reaction: C 2 H 4 + 2HCl + ½ O 2 → C 2 H 4 Cl 2 + H 2 O follows a three steps mechanism: (i) reduction of CuCl 2 to CuCl (2CuCl 2 + C 2 H 4 → C 2 H 4 Cl 2 + 2CuCl), (ii) oxidation of CuCl to give an oxychloride (2CuCl + ½ O 2 → Cu 2 OCl 2) and (iii) closure of the catalytic circle by rechlorination with HCl, restoring the original CuCl 2 (Cu 2 OCl 2 + 2HCl → 2CuCl 2 + H 2 O). Finally, we have shown that time resolved, in situ, spectroscopy is a very promising technique to investigate the interplay between catalyst activity and oxidation state of copper.

The Journal of Physical Chemistry B, 2009

H/D isotopic substitution neutron scattering has been used to investigate the short and intermedi... more H/D isotopic substitution neutron scattering has been used to investigate the short and intermediate range solution structure in a 1 m aqueous solution of chromium nitrate. To improve the reliability of the local structural information on the cation environment, information has been incorporated from available extended X-ray absorption fine structure (EXAFS) spectroscopy data into the applied analytical framework. The markedly different structural sensitivities of the experimental probes allow the construction of a detailed three-dimensional atomistic model using the empirical potential structure refinement (EPSR) technique. The method facilitates the construction of a model that is consistent with regards to both the structural details of the immediate Cr 3+ aqua-ion environment and the bulk hydrogen-bonded network of solvent water molecules. The results confirm the suitability of the [Cr(H 2 O) 6 ] 3+ hydrated ion concept to describe the first hydration shell of this cation and clarify how this pseudomolecular unit is structurally incorporated in the longer range aqueous environment.

The Journal of Physical Chemistry B, 2005

The structure of the trimolecular liquid mixture of 2:6:1 cyclohexene, tert-butyl alcohol, and wa... more The structure of the trimolecular liquid mixture of 2:6:1 cyclohexene, tert-butyl alcohol, and water has been investigated using hydrogen/deuterium substitution neutron scattering techniques, and a three-dimensional structural model refined to be consistent with the experimental data has been built using the technique of Empirical Potential Structure Refinement. The model shows a well-mixed solution of the three molecular components where the competing interactions between the nonpolar cyclohexene and polar water molecules are balanced in the solution leading to largely pure-alcohol-like interactions between the tert-butyl alcohol molecules. Cyclohexene molecules favor direct solvation by alcohol methyl groups while water molecules are accommodated, dispersed throughout the solution, via hydrogen bonding interactions with the alcohol molecule hydroxyl groups. Rare occurrences of direct cyclohexene-water interactions are of the classic hydrophobic hydration type and no evidence is found for microscopic heterogeneity in the trimolecular mixture in contrast to the general findings for binary alcohol-water solutions.

Journal of Volcanology and Geothermal Research, 1984

Abstract The cooling of a magmatic intrusion is simulated by a simple model of a non-homogeneous ... more Abstract The cooling of a magmatic intrusion is simulated by a simple model of a non-homogeneous earth, with thermal properties depending on temperature, in which heat transfer is assumed to take place by conduction only. The mathematical problem consists in solving a non-linear partial differential equation with continuity conditions on temperature and heat flux imposed at the contacts between different rocks. This has been done numerically by a finite difference method. The model is then adopted as “reality” against which a number of commonly used approximations are tested. It is found that the effect of latent heat liberation can be reasonably taken into account by attributing an effective initial temperature to the magma (errors within 20°C for t > 10 5 years, when the temperature of the magma is still as high as 600°C); the effective specific heat approximation does not work as well. The dependence of thermal conductivity and specific heat on temperature may be eliminated by maintaining the errors within 30°C for t 5 years. The assumption that magma and country rocks have the same thermal properties allows an estimate of the temperature field in the host rocks with errors of 50°C at most. The assumption that all rocks have the same constant conductivity yields results that are far from “reality” (errors of 100–200°C even at shallow depth).

Journal of Synchrotron Radiation, 2009

The design and performance of the microfocus spectroscopy beamline at the Diamond Light Source ar... more The design and performance of the microfocus spectroscopy beamline at the Diamond Light Source are described. The beamline is based on a 27 mm-period undulator to give an operable energy range between 2 and 20.7 keV, enabling it to cover the K-edges of the elements from P to Mo and the L 3-edges from Sr to Pu. Micro-X-ray fluorescence, micro-EXAFS and micro-X-ray diffraction have all been achieved on the beamline with a spot size of $ 3 mm. The principal optical elements of the beamline consist of a toroid mirror, a liquid-nitrogencooled double-crystal monochromator and a pair of bimorph Kirkpatrick-Baez mirrors. The performance of the optics is compared with theoretical values and a few of the early experimental results are summarized.

International Journal of Remote Sensing, 2013

ABSTRACT Free download in http://www.tandfonline.com/eprint/meHpmgGCG6Jq8NYwaKqF/full The possibi... more ABSTRACT Free download in http://www.tandfonline.com/eprint/meHpmgGCG6Jq8NYwaKqF/full The possibility of obtaining e 0 from three global MODIS algorithms for W retrieval was also tested and compared to our algorithm. The results show that our algorithm gives better results than the International MODIS/Atmospheric InfraRed Sounder Processing Package IMAPP Water Vapour Near-Infrared WVNIR product and the Sobrino algorithm. The MODIS Total Precipitable Water MOD05 product is worse than that obtained with our algorithm in Asturias R 2 = 0.61 vs. R 2 = 0.65, but the two values are similar if the stations in La Coruña R 2 = 0.60 and Santander R 2 = 0.56 are included in the comparison. The dominant advantage of the novel algorithm proposed in this study is that it is simpler and can be produced quickly in real time.

Dalton Transactions, 2005

Time resolved energy dispersive X-ray absorption spectroscopy has been used to follow the structu... more Time resolved energy dispersive X-ray absorption spectroscopy has been used to follow the structural evolution of the inner-sphere electron transfer reaction between [IrCl6]2- and [Co(CN)5]3-, and to characterise the local structure of the iridium metal centre in the bridged activated complex formed during the reaction.