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2. Reactivity of OH and CH3OH between 22 and 64 K: Modelling the gas phase production of CH3O in Barnard 1b

Author

Antinolo, M., Agundez, M., Jimenez, E., Ballesteros, B., Canosa, A., Dib, G. El, Albaladejo, J., and Cernicharo, J.

Subjects
Astrophysics - Astrophysics of Galaxies
Abstract

In the last years, ultra-low temperature chemical kinetic experiments have demonstrated that some gas-phase reactions are much faster than previously thought. One example is the reaction between OH and CH3OH, which has been recently found to be accelerated at low temperatures yielding CH3O as main product. This finding opened the question of whether the CH3O observed in the dense core Barnard 1b could be formed by the gas-phase reaction of CH3OH and OH. Several chemical models including this reaction and grain-surface processes have been developed to explain the observed abundance of CH$_3$O with little success. Here we report for the first time rate coefficients for the gas-phase reaction of OH and CH3OH down to a temperature of 22 K, very close to those in cold interstellar clouds. Two independent experimental set-ups based on the supersonic gas expansion technique coupled to the pulsed laser photolysis-laser induced fluorescence technique were used to determine rate coefficients in the temperature range 22-64 K. The temperature dependence obtained in this work can be expressed as k(22-64 K) = (3.6+/-0.1)e-12 (T/ 300)^(-1.0+/-0.2) cm3 molecule-1 s-1. Implementing this expression in a chemical model of a cold dense cloud results in CH3O/CH3OH abundance ratios similar or slightly lower than the value of 3e-3 observed in Barnard 1b. This finding confirms that the gas-phase reaction between OH and CH3OH is an important contributor to the formation of interstellar CH3O. The role of grain-surface processes in the formation of CH3O, although it cannot be fully neglected, remains controversial., Comment: Accepted for publication in The Astrophysical Journal

Published
2016
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9. The impact of water vapor on the OH reactivity toward CH3CHO at ultra-low temperatures (21.7–135.0 K): Experiments and theory.

Author

Neeman, E. M., González, D., Blázquez, S., Ballesteros, B., Canosa, A., Antiñolo, M., Vereecken, L., Albaladejo, J., and Jiménez, E.

Subjects
WATER vapor, ACETALDEHYDE, TEMPERATURE, ORGANIC compounds
Abstract

The role of water vapor (H2O) and its hydrogen-bonded complexes in the gas-phase reactivity of organic compounds with hydroxyl (OH) radicals has been the subject of many recent studies. Contradictory effects have been reported at temperatures between 200 and 400 K. For the OH + acetaldehyde reaction, a slight catalytic effect of H2O was previously reported at temperatures between 60 and 118 K. In this work, we used Laval nozzle expansions to reinvestigate the impact of H2O on the OH-reactivity with acetaldehyde between 21.7 and 135.0 K. The results of this comprehensive study demonstrate that water, instead, slows down the reaction by factors of ∼3 (21.7 K) and ∼2 (36.2–89.5 K), and almost no effect of added H2O was observed at 135.0 K. [ABSTRACT FROM AUTHOR]

Published
2021
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12. 20193. OREJA AZUL: UN SIGNO DE TOXICIDAD POR CLOZAPINA

Author

González Antón, D., Vela Desojo, L., Ruiz López, C., Barcenilla López, M., Contreras Peña, J., de la Cruz Fernández, N., Arribas Ballesteros, B., Colligris Micheralaki, P., de la Torre Pérez, A., Méndez Valdés, A., Pinedo Moraleja, F., and López Blanco, R.

Published
2024
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20. Performance of cubic-(La,Sr)TiO3+δ as SOFC anodes

Author

Marrero-López, D., Irvine, J. T. S., Ballesteros, B., Ruiz-Morales, J. C., and Canales-Vázquez, J.

Subjects
Solid Oxide Fuel Cell, anodes, titanates, composites, current collector, Pilas de Combustible de Óxido Sólido, ánodos, titanatos, colector de corriente, Clay industries. Ceramics. Glass, TP785-869
Abstract

The performance and potential application of the cubic members of the La4Srn-4TinO3n+2 series of compounds, i.e. n≥12, prepared by solid state reaction are discussed. Although these phases can be indexed as cubic perovskites by X-ray diffraction (XRD), there exists some oxygen beyond the ABO3 stoichiometry accommodated in linear defects reminiscent to the oxygen rich layers in La2Ti2O7. In the present work, we report preliminary fuel cell tests of the n=12,14 and 16 of the La4Srn-4TinO3n+2 series, which reveal moderate responses under hydrogen, but also some promising results implying activation favouring methane oxidation.En este trabajo se presentan las prestaciones y el potencial uso de las fases cúbicas de la serie homóloga con fórmula La4Srn-4TinO3n+2 (n≥12) preparadas por reacción en el estado sólido. A pesar de que estas fases pueden describirse como perovskitas cúbicas mediante difracción de rayos-X (DRX), existe una cantidad de oxígeno superestequiométrico respecto a la composición ideal de la perovskita ABO3 localizado en defectos lineales análogos a las capas ricas en oxígeno en La2Ti2O7. En el presente trabajo, se muestran ensayos en pilas de combustible realizados en las composiciones n=12,14 and 16 de la serie La4Srn-4TinO3n+2 , donde se muestran respuestas moderadas en hidrógeno, así como una cierta activación que favorece la oxidación del metano.

Published
2007

29. Quadrupolar Cyclopenta[hi]aceanthrylene-Based Electron Donor-Acceptor-Donor Conjugates: Charge Transfer versus Charge Separation

Author

Schierl C., Alex W., Mateo L.M., Ballesteros B., Shimizu D., Osuka A., Torres T., Guldi D.M., Bottari G. and Financial support from Spanish MICINN (CTQ2017-85393-P) is acknowledged. IMDEA Nanociencia acknowledges support from the ?Severo Ochoa? Programme for Centres of Excellence in R&D (MINECO, Grant SEV2016-0686). The work at Kyoto was supported by JSPS KAKENHI grant numbers 18H03910 and 18K19074. D.S. acknowledges a JSPS fellowship for young scientists. This work was financially supported by the Deutsche Forschungsgemeinschaft (DFG) by the SFB 953 ?Synthetic Carbon Allotropes?. C.S. gratefully acknowledges the Fonds der Chemischen Industrie (FCI) for funding. C.S. and W.A. thank the Graduate School of Molecular Science for financial support.

Published
2019

33. P183 Colombian real-world experience of vedolizumab use in patients with inflammatory bowel disease—EXVEDOCOL

Author

V Parra Izquierdo, S Cifuentes Amortegui, S Avendaño R., E Ponce de Léon, C Flórez, G Reyes Medina, F E Puentes M, M Ballesteros B., E E Nuñez, M Hernández, J Kock, and J R Márquez

Subjects
medicine.medical_specialty, business.industry, Internal medicine, Gastroenterology, medicine, In patient, General Medicine, business, medicine.disease, Inflammatory bowel disease, Vedolizumab, medicine.drug
Published
2019
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34. P183 Colombian real-world experience of vedolizumab use in patients with inflammatory bowel disease—EXVEDOCOL

Author

Parra Izquierdo, V, primary, Cifuentes Amortegui, S, additional, Avendaño R., S, additional, Ponce de Léon, E, additional, Flórez, C, additional, Reyes Medina, G, additional, Puentes M, F E, additional, Ballesteros B., M, additional, Nuñez, E E, additional, Hernández, M, additional, Kock, J, additional, and Márquez, J R, additional

Published
2019
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41. Comment on “Methanol dimer formation drastically enhances hydrogen abstraction from methanol by OH at low temperature” by W. Siebrand, Z. Smedarchina, E. Martínez-Núñez and A. Fernández-Ramos, Phys. Chem. Chem. Phys., 2016, 18, 22712

Author

Shannon, R. J., primary, Gómez Martín, J. C., additional, Caravan, R. L., additional, Blitz, M. A., additional, Plane, J. M. C., additional, Heard, D. E., additional, Antiñolo, M., additional, Agúndez, M., additional, Jiménez, E., additional, Ballesteros, B., additional, Canosa, A., additional, El Dib, G., additional, Albaladejo, J., additional, and Cernicharo, J., additional

Published
2018
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43. Is the Gas-phase OH+H2CO Reaction a Source of HCO in Interstellar Cold Dark Clouds? A Kinetic, Dynamic, and Modeling Study

Author

Institut national des sciences de l'Univers (France), European Cooperation in Science and Technology, Consejo Superior de Investigaciones Científicas (España), Ministerio de Economía y Competitividad (España), Ministerio de Ciencia e Innovación (España), European Commission, Universidad de Castilla La Mancha, Ocaña, A. J., Jiménez, E., Ballesteros, B., Canosa, André, Antiñolo, M., Albaladejo, J., Agúndez, Marcelino, Cernicharo, José, Zanchet, Alexandre, Mazo-Sevillano, Pablo del, Roncero, Octavio, Aguado, Alfredo, Institut national des sciences de l'Univers (France), European Cooperation in Science and Technology, Consejo Superior de Investigaciones Científicas (España), Ministerio de Economía y Competitividad (España), Ministerio de Ciencia e Innovación (España), European Commission, Universidad de Castilla La Mancha, Ocaña, A. J., Jiménez, E., Ballesteros, B., Canosa, André, Antiñolo, M., Albaladejo, J., Agúndez, Marcelino, Cernicharo, José, Zanchet, Alexandre, Mazo-Sevillano, Pablo del, Roncero, Octavio, and Aguado, Alfredo

Abstract

The chemical kinetics of neutral-neutral gas-phase reactions at ultralow temperatures is a fascinating research subject with important implications on the chemistry of complex organic molecules in the interstellar medium (T ∼ 10-100 K). Scarce kinetic information is currently available for these kinds of reactions at T < 200 K. In this work, we use the Cinétique de Réaction en Ecoulement Supersonique Uniforme (CRESU; Reaction Kinetics in a Uniform Supersonic Flow) technique to measure for the first time the rate coefficients (k) of the gas-phase OH+HCO reaction between 22 and 107 K. The k values greatly increase from 2.1 × 10 cm s at 107 K to 1.2 × 10 cm s at 22 K. This is also confirmed by quasi-classical trajectories (QCT) at collision energies down to 0.1 meV performed using a new full dimension and ab initio potential energy surface that generates highly accurate potential and includes long-range dipole-dipole interactions. QCT calculations indicate that at low temperatures HCO is the exclusive product for the OH+HCO reaction. In order to revisit the chemistry of HCO in cold dense clouds, k is reasonably extrapolated from the experimental results at 10 K (2.6 × 10 cm s). The modeled abundances of HCO are in agreement with the observations in cold dark clouds for an evolving time of 10-10 yr. The different sources of production of HCO are presented and the uncertainties in the chemical networks are discussed. The present reaction is shown to account for a few percent of the total HCO production rate. This reaction can be expected to be a competitive process in the chemistry of prestellar cores. Extensions to photodissociation regions and diffuse cloud environments are also addressed.

Published
2017

44. Synthesis and characterization of WS₂ inorganic nanotubes with encapsulated/intercalated CsI

Author

Hong, S, Popovitz-Biro, R, Tobias, G, Ballesteros, B, Davis, B, Green, M, and Tenne, R

Subjects
Chemistry & allied sciences, Materials Sciences, Inorganic chemistry
Abstract

WS₂ nanotubes have been filled and intercalated by molten phase caesium iodide. The presence of caesium iodide inside the WS₂ nanotubes has been determined using high-resolution transmission electron microscopy (HRTEM) coupled with electron energy-loss spectroscopy (EELS) and energy-dispersive X-ray spectroscopy (EDS). Noticeably, a Moiré pattern was observed due to the interference between encapsulated CsI and WS₂ layers. The intercalation of CsI into the host concentric WS₂ lattices resulted in an increase in the interplanar spacing.

Published
2016

48. Identificación De Peligros En El Proceso De Servicios Gas Domiciliario En Dos (2) Empresas De La Ciudad De Santiago De Cali (Valle Del Cauca) 2015

Author

Ballesteros B, Ángela R, Castro M, Maryi L, Mosquera L, Jenny J, Universidad del Quindío-Colombia-Asesor- Nieto S Liliana P, and Universidad del Quindío-Colombia-Asesor-Villegas L Luz E

Subjects
Peligro, Planteamiento del problema
Abstract

La seguridad de los trabajadores es uno de los factores fundamentales más importantes, para el desarrollo de la organización que tienen en cuenta los seres humanos que laboran en ella, por esta razón es necesario identificar los peligros a los que están expuestos los trabajadores. El tema de la seguridad es de gran importancia ya que ayuda a mantener en óptimas condiciones la salud de los trabajadores, además es un fenómeno que se le logra a partir de acciones que no tienen fin y que se pueden mantener por mucho tiempo, debido a que hay muchas razones por la cual una de ellas es la falta de conocimiento de auto cuidado y acciones correctivas para ellos., Introducción 10, 1. Justificación 11, 2. Planteamiento del problema 12, 3. Objetivos 14, 4. Marco de referencia 15, Pregrado, Profesional en Seguridad y Salud en el Trabajo

Published
2015

49. Experimental Studies on the Chemical Reactivity of Small Oxygenates towards OH radicals at the Ultra-Low temperatures in the Dense Molecular Clouds of the Interstellar Medium

Author

Antinolo, Maria, Ballesteros, B., Jimenez, Elena, Canosa, André, El Dib, Gisèle, Albaladejo, J., El Dib, Gisele, Departamento de Química Física, Facultad de Ciencias Quimicas, Institut de Physique de Rennes (IPR), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), and Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], CRESU, Molecular physics, ComputingMilieux_MISCELLANEOUS, [PHYS.PHYS.PHYS-AO-PH] Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph]
Abstract

International audience

Published
2015

50. Atmospheric reactivity of hydroxyketones: photolysis and reaction with OH radicals and Cl atoms

Author

Laversin, H., Sleiman, Chantal, El Dib, Gisèle, Bouzidi, Hichem, Moreno, Alberto, Tomas, Alexandre, Canosa, André, Roth, Estelle, Ballesteros, B., Chakir, A., El Dib, Gisele, Groupe de spectrométrie moléculaire et atmosphérique (GSMA), Université de Reims Champagne-Ardenne (URCA)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique de Rennes (IPR), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique de l'ENS Lyon (Phys-ENS), École normale supérieure - Lyon (ENS Lyon)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon, Departamento de Química Física, Facultad de Ciencias Quimicas, Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], ComputingMilieux_MISCELLANEOUS, [PHYS.PHYS.PHYS-AO-PH] Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph]
Abstract

International audience

Published
2015

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