The Experts below are selected from a list of 90 Experts worldwide ranked by ideXlab platform
Guy Cernogora - One of the best experts on this subject based on the ideXlab platform.
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formation of amino acids and nucleotide bases in a Titan Atmosphere simulation experiment
Astrobiology, 2012Co-Authors: S M Horst, Nathalie Carrasco, Guy Cernogora, Arnaud Buch, R V Yelle, O Dutuit, E Quirico, Ella Sciammaobrien, Mark A Smith, Arpad SomogyiAbstract:Abstract The discovery of large (>100 u) molecules in Titan's upper Atmosphere has heightened astrobiological interest in this unique satellite. In particular, complex organic aerosols produced in Atmospheres containing C, N, O, and H, like that of Titan, could be a source of prebiotic molecules. In this work, aerosols produced in a Titan Atmosphere simulation experiment with enhanced CO (N2/CH4/CO gas mixtures of 96.2%/2.0%/1.8% and 93.2%/5.0%/1.8%) were found to contain 18 molecules with molecular formulae that correspond to biological amino acids and nucleotide bases. Very high-resolution mass spectrometry of isotopically labeled samples confirmed that C4H5N3O, C4H4N2O2, C5H6N2O2, C5H5N5, and C6H9N3O2 are produced by chemistry in the simulation chamber. Gas chromatography–mass spectrometry (GC-MS) analyses of the non-isotopic samples confirmed the presence of cytosine (C4H5N3O), uracil (C5H4N2O2), thymine (C5H6N2O2), guanine (C5H5N5O), glycine (C2H5NO2), and alanine (C3H7NO2). Adenine (C5H5N5) was dete...
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Nitrile gas chemistry in Titan Atmosphere
Icarus, 2011Co-Authors: Thomas Gautier, Nathalie Carrasco, Ella Sciamma-o'brien, Cyril Szopa, Arnaud Buch, Guy CernogoraAbstract:This work presents the first study of the gaseous products resulting from the partial dissociation of methane and nitrogen in the PAMPRE experimental setup simulating Titan's atmospheric chemistry. Using cryogenic trapping, the gaseous products generated from the chemical reactions occurring in the reactor have been trapped. Analyses of these products by gas chromatography coupled with mass spectrometry have allowed the detection and identification of more than 30 reaction products. Most of them are identified as nitrile species, accompanied by aliphatic hydrocarbons and a few aromatics compounds. The observed species are in agreement with the data from the recent Cassini-Huygens mission as well as from other laboratory setups capable of dissociating nitrogen and methane. This work emphasizes the probable importance of nitrogen-bearing compounds in the chemistry taking place in Titan's Atmosphere. Furthermore, a quantification of mono-nitriles with saturated alkyl chains has been performed relatively to hydrogen cyanide and shows a power-law dependence in their concentration. This dependence is consistent with the Cassini-INMS data and Titan's photochemical models. An empirical relationship has been extracted from our experimental data: [CxH2x-1N] = 100x-5 where X is the number of carbon atoms in the nitrile molecule. This relationship can be directly used in order to foretell the concentration of heavier nitriles induced by chemistry in Titan's Atmosphere.
Thomas Gautier - One of the best experts on this subject based on the ideXlab platform.
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Titan s Atmosphere simulation experiment using continuum uv vuv synchrotron radiation
Journal of Geophysical Research, 2013Co-Authors: Nathalie Carrasco, Thomas Gautier, Arnaud Buch, Zhe Peng, Pascal Pernot, Alexandre Giuliani, Ahmed Mahjoub, Jeanjacques Correia, Y BenilanAbstract:[1] A new reactor, named APSIS for Atmospheric Photochemistry Simulated by Synchrotron, is designed for simulating the reactivity occurring in planetary upper Atmospheres. In this reactor, a gas mixture roughly reproducing Titan's main Atmosphere composition (N2/CH4 = 90/10) is irradiated by a continuous spectrum in the 60−350 nm range, provided by the DISCO beamline at the SOLEIL synchrotron radiation facility. This spectral range enables the dissociation and ionization of N2 and CH4, as observed in plasma reactors and Titan's ionosphere. The neutral products are detected in situ by quadrupole mass spectrometry and collected with a cryogenic trap for ex situ analysis by gas chromatography-mass spectrometry. The detected reaction products include C2, C3, C4, and probably C5 organic compounds, with important amounts of nitrogen-bearing species: HCN, CH3CN, and C2N2. Neutral mass spectra obtained with APSIS are compared with Ion and Neutral Mass Spectrometer experiments of the Cassini space probe in the upper Titan Atmosphere and with other results of current Titan Atmosphere chemistry laboratory simulations.
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Nitrile gas chemistry in Titan Atmosphere
Icarus, 2011Co-Authors: Thomas Gautier, Nathalie Carrasco, Ella Sciamma-o'brien, Cyril Szopa, Arnaud Buch, Guy CernogoraAbstract:This work presents the first study of the gaseous products resulting from the partial dissociation of methane and nitrogen in the PAMPRE experimental setup simulating Titan's atmospheric chemistry. Using cryogenic trapping, the gaseous products generated from the chemical reactions occurring in the reactor have been trapped. Analyses of these products by gas chromatography coupled with mass spectrometry have allowed the detection and identification of more than 30 reaction products. Most of them are identified as nitrile species, accompanied by aliphatic hydrocarbons and a few aromatics compounds. The observed species are in agreement with the data from the recent Cassini-Huygens mission as well as from other laboratory setups capable of dissociating nitrogen and methane. This work emphasizes the probable importance of nitrogen-bearing compounds in the chemistry taking place in Titan's Atmosphere. Furthermore, a quantification of mono-nitriles with saturated alkyl chains has been performed relatively to hydrogen cyanide and shows a power-law dependence in their concentration. This dependence is consistent with the Cassini-INMS data and Titan's photochemical models. An empirical relationship has been extracted from our experimental data: [CxH2x-1N] = 100x-5 where X is the number of carbon atoms in the nitrile molecule. This relationship can be directly used in order to foretell the concentration of heavier nitriles induced by chemistry in Titan's Atmosphere.
Nathalie Carrasco - One of the best experts on this subject based on the ideXlab platform.
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Titan s Atmosphere simulation experiment using continuum uv vuv synchrotron radiation
Journal of Geophysical Research, 2013Co-Authors: Nathalie Carrasco, Thomas Gautier, Arnaud Buch, Zhe Peng, Pascal Pernot, Alexandre Giuliani, Ahmed Mahjoub, Jeanjacques Correia, Y BenilanAbstract:[1] A new reactor, named APSIS for Atmospheric Photochemistry Simulated by Synchrotron, is designed for simulating the reactivity occurring in planetary upper Atmospheres. In this reactor, a gas mixture roughly reproducing Titan's main Atmosphere composition (N2/CH4 = 90/10) is irradiated by a continuous spectrum in the 60−350 nm range, provided by the DISCO beamline at the SOLEIL synchrotron radiation facility. This spectral range enables the dissociation and ionization of N2 and CH4, as observed in plasma reactors and Titan's ionosphere. The neutral products are detected in situ by quadrupole mass spectrometry and collected with a cryogenic trap for ex situ analysis by gas chromatography-mass spectrometry. The detected reaction products include C2, C3, C4, and probably C5 organic compounds, with important amounts of nitrogen-bearing species: HCN, CH3CN, and C2N2. Neutral mass spectra obtained with APSIS are compared with Ion and Neutral Mass Spectrometer experiments of the Cassini space probe in the upper Titan Atmosphere and with other results of current Titan Atmosphere chemistry laboratory simulations.
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formation of amino acids and nucleotide bases in a Titan Atmosphere simulation experiment
Astrobiology, 2012Co-Authors: S M Horst, Nathalie Carrasco, Guy Cernogora, Arnaud Buch, R V Yelle, O Dutuit, E Quirico, Ella Sciammaobrien, Mark A Smith, Arpad SomogyiAbstract:Abstract The discovery of large (>100 u) molecules in Titan's upper Atmosphere has heightened astrobiological interest in this unique satellite. In particular, complex organic aerosols produced in Atmospheres containing C, N, O, and H, like that of Titan, could be a source of prebiotic molecules. In this work, aerosols produced in a Titan Atmosphere simulation experiment with enhanced CO (N2/CH4/CO gas mixtures of 96.2%/2.0%/1.8% and 93.2%/5.0%/1.8%) were found to contain 18 molecules with molecular formulae that correspond to biological amino acids and nucleotide bases. Very high-resolution mass spectrometry of isotopically labeled samples confirmed that C4H5N3O, C4H4N2O2, C5H6N2O2, C5H5N5, and C6H9N3O2 are produced by chemistry in the simulation chamber. Gas chromatography–mass spectrometry (GC-MS) analyses of the non-isotopic samples confirmed the presence of cytosine (C4H5N3O), uracil (C5H4N2O2), thymine (C5H6N2O2), guanine (C5H5N5O), glycine (C2H5NO2), and alanine (C3H7NO2). Adenine (C5H5N5) was dete...
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Nitrile gas chemistry in Titan Atmosphere
Icarus, 2011Co-Authors: Thomas Gautier, Nathalie Carrasco, Ella Sciamma-o'brien, Cyril Szopa, Arnaud Buch, Guy CernogoraAbstract:This work presents the first study of the gaseous products resulting from the partial dissociation of methane and nitrogen in the PAMPRE experimental setup simulating Titan's atmospheric chemistry. Using cryogenic trapping, the gaseous products generated from the chemical reactions occurring in the reactor have been trapped. Analyses of these products by gas chromatography coupled with mass spectrometry have allowed the detection and identification of more than 30 reaction products. Most of them are identified as nitrile species, accompanied by aliphatic hydrocarbons and a few aromatics compounds. The observed species are in agreement with the data from the recent Cassini-Huygens mission as well as from other laboratory setups capable of dissociating nitrogen and methane. This work emphasizes the probable importance of nitrogen-bearing compounds in the chemistry taking place in Titan's Atmosphere. Furthermore, a quantification of mono-nitriles with saturated alkyl chains has been performed relatively to hydrogen cyanide and shows a power-law dependence in their concentration. This dependence is consistent with the Cassini-INMS data and Titan's photochemical models. An empirical relationship has been extracted from our experimental data: [CxH2x-1N] = 100x-5 where X is the number of carbon atoms in the nitrile molecule. This relationship can be directly used in order to foretell the concentration of heavier nitriles induced by chemistry in Titan's Atmosphere.
Arnaud Buch - One of the best experts on this subject based on the ideXlab platform.
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Titan s Atmosphere simulation experiment using continuum uv vuv synchrotron radiation
Journal of Geophysical Research, 2013Co-Authors: Nathalie Carrasco, Thomas Gautier, Arnaud Buch, Zhe Peng, Pascal Pernot, Alexandre Giuliani, Ahmed Mahjoub, Jeanjacques Correia, Y BenilanAbstract:[1] A new reactor, named APSIS for Atmospheric Photochemistry Simulated by Synchrotron, is designed for simulating the reactivity occurring in planetary upper Atmospheres. In this reactor, a gas mixture roughly reproducing Titan's main Atmosphere composition (N2/CH4 = 90/10) is irradiated by a continuous spectrum in the 60−350 nm range, provided by the DISCO beamline at the SOLEIL synchrotron radiation facility. This spectral range enables the dissociation and ionization of N2 and CH4, as observed in plasma reactors and Titan's ionosphere. The neutral products are detected in situ by quadrupole mass spectrometry and collected with a cryogenic trap for ex situ analysis by gas chromatography-mass spectrometry. The detected reaction products include C2, C3, C4, and probably C5 organic compounds, with important amounts of nitrogen-bearing species: HCN, CH3CN, and C2N2. Neutral mass spectra obtained with APSIS are compared with Ion and Neutral Mass Spectrometer experiments of the Cassini space probe in the upper Titan Atmosphere and with other results of current Titan Atmosphere chemistry laboratory simulations.
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formation of amino acids and nucleotide bases in a Titan Atmosphere simulation experiment
Astrobiology, 2012Co-Authors: S M Horst, Nathalie Carrasco, Guy Cernogora, Arnaud Buch, R V Yelle, O Dutuit, E Quirico, Ella Sciammaobrien, Mark A Smith, Arpad SomogyiAbstract:Abstract The discovery of large (>100 u) molecules in Titan's upper Atmosphere has heightened astrobiological interest in this unique satellite. In particular, complex organic aerosols produced in Atmospheres containing C, N, O, and H, like that of Titan, could be a source of prebiotic molecules. In this work, aerosols produced in a Titan Atmosphere simulation experiment with enhanced CO (N2/CH4/CO gas mixtures of 96.2%/2.0%/1.8% and 93.2%/5.0%/1.8%) were found to contain 18 molecules with molecular formulae that correspond to biological amino acids and nucleotide bases. Very high-resolution mass spectrometry of isotopically labeled samples confirmed that C4H5N3O, C4H4N2O2, C5H6N2O2, C5H5N5, and C6H9N3O2 are produced by chemistry in the simulation chamber. Gas chromatography–mass spectrometry (GC-MS) analyses of the non-isotopic samples confirmed the presence of cytosine (C4H5N3O), uracil (C5H4N2O2), thymine (C5H6N2O2), guanine (C5H5N5O), glycine (C2H5NO2), and alanine (C3H7NO2). Adenine (C5H5N5) was dete...
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Nitrile gas chemistry in Titan Atmosphere
Icarus, 2011Co-Authors: Thomas Gautier, Nathalie Carrasco, Ella Sciamma-o'brien, Cyril Szopa, Arnaud Buch, Guy CernogoraAbstract:This work presents the first study of the gaseous products resulting from the partial dissociation of methane and nitrogen in the PAMPRE experimental setup simulating Titan's atmospheric chemistry. Using cryogenic trapping, the gaseous products generated from the chemical reactions occurring in the reactor have been trapped. Analyses of these products by gas chromatography coupled with mass spectrometry have allowed the detection and identification of more than 30 reaction products. Most of them are identified as nitrile species, accompanied by aliphatic hydrocarbons and a few aromatics compounds. The observed species are in agreement with the data from the recent Cassini-Huygens mission as well as from other laboratory setups capable of dissociating nitrogen and methane. This work emphasizes the probable importance of nitrogen-bearing compounds in the chemistry taking place in Titan's Atmosphere. Furthermore, a quantification of mono-nitriles with saturated alkyl chains has been performed relatively to hydrogen cyanide and shows a power-law dependence in their concentration. This dependence is consistent with the Cassini-INMS data and Titan's photochemical models. An empirical relationship has been extracted from our experimental data: [CxH2x-1N] = 100x-5 where X is the number of carbon atoms in the nitrile molecule. This relationship can be directly used in order to foretell the concentration of heavier nitriles induced by chemistry in Titan's Atmosphere.
Mary Ann H Smith - One of the best experts on this subject based on the ideXlab platform.
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ft ir measurements of cold c3h8 cross sections at 7 15 μm for Titan Atmosphere
Icarus, 2013Co-Authors: Keeyoon Sung, Geoffrey C Toon, A W Mantz, Mary Ann H SmithAbstract:Abstract We present absorption cross sections of propane (C3H8) at temperatures from 145 K to 297 K in the 690–1550 cm−1 region. Pure and N2-broadened spectra were measured at pressures from 3 Torr to 742 Torr using a Bruker IFS125 FT-IR spectrometer at JPL. The gas absorption cell, developed at Connecticut College, was cooled by a closed-cycle helium refrigerator. The cross sections were measured and compiled for individual spectra recorded at various experimental conditions covering the planetary Atmosphere and Titan. In addition to the cross sections, a propane pseudoline list with a frequency grid of 0.005 cm−1, was fitted to the 34 laboratory spectra. Line intensities and lower state energies were retrieved for each line, assuming a constant width. Validation tests showed that the pseudoline list reproduces discrete absorption features and continuum, the latter contributed by numerous weak and hot band features, in most of the observed spectra within 3%. Based on the pseudoline list, the total intensity in the 690–1550 cm−1 region was determined to be 52.93 (±3%) × 10−19 cm−1/(molecule cm−2) at 296 K; this value is within 3% of the average from four earlier studies. Finally, the merit of the pseudoline approach is addressed for heavy polyatomic molecules in support of spectroscopic observation of Atmospheres of Titan and other planets. The cold cross sections will be submitted to the HITRAN database (hitran.harvard.edu), and the list of C3H8 pseudolines will be available from a MK-IV website of JPL ( http://mark4sun.jpl.nasa.gov/data/spec/Pseudo ).