The Experts below are selected from a list of 192 Experts worldwide ranked by ideXlab platform
Jannis Samios - One of the best experts on this subject based on the ideXlab platform.
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density dependence of the structural properties and translational diffusion of Carbonyl Sulphide diluted in monoatomic solvents a molecular dynamics investigation
Journal of Molecular Liquids, 1996Co-Authors: Dimitris Dellis, Jannis SamiosAbstract:Abstract We report a study of the intermolecular structure and translational diffusion of Carbonyl Sulphide (OCS) dissolved in Ne and Kr, using Molecular Dynamics (MD) simulation. The mixtures have been investigated at different thermodynamic points corresponding to the pressures between 5 and 300 bar and at temperature of 293 K. The computations were carried out with effective site-site Lennard-Jones (LJ) potential model. We found that the proposed model predicts a non-linear T-shaped dimer structure of Ne-OCS and Kr-OCS in accordance with experiment. The study of the local structure of the solute-solvents was based upon the calculated relevant pair distribution functions. The self-diffusion coefficients of both components in the mixtures were calculated and compared. The results show a non-linear dependence in the density range under study. In the case of Kr as solvent and at the whole density range under study, the diffusion coefficient of Kr appears to be larger than that of OCS. This unusual result on the solute-solvent diffusivities ( m OCS m Kr , D OCS D Kr ) has been further discussed in terms of the microscopic dynamics of the species.
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Density dependence of the structural properties and translational diffusion of Carbonyl Sulphide diluted in monoatomic solvents. A molecular dynamics investigation
Journal of Molecular Liquids, 1996Co-Authors: Dimitris Dellis, Jannis SamiosAbstract:Abstract We report a study of the intermolecular structure and translational diffusion of Carbonyl Sulphide (OCS) dissolved in Ne and Kr, using Molecular Dynamics (MD) simulation. The mixtures have been investigated at different thermodynamic points corresponding to the pressures between 5 and 300 bar and at temperature of 293 K. The computations were carried out with effective site-site Lennard-Jones (LJ) potential model. We found that the proposed model predicts a non-linear T-shaped dimer structure of Ne-OCS and Kr-OCS in accordance with experiment. The study of the local structure of the solute-solvents was based upon the calculated relevant pair distribution functions. The self-diffusion coefficients of both components in the mixtures were calculated and compared. The results show a non-linear dependence in the density range under study. In the case of Kr as solvent and at the whole density range under study, the diffusion coefficient of Kr appears to be larger than that of OCS. This unusual result on the solute-solvent diffusivities (mOCS
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molecular dynamics investigations of the electrostatic interactions in liquid Carbonyl Sulphide
Molecular Physics, 1992Co-Authors: Hubert Stassen, Th Dorfmuller, Jannis SamiosAbstract:Molecular dynamics simulation was used to obtain information concerning the electrostatic contributions of dipole, quadrupole and octupole moments to the pair potential of liquid Carbonyl Sulphide. The influence of electrostatics is determined by the equilibrium properties of the liquid. These indicate that taking into account dipole and quadrupole moments, results are obtained in accordance with the Lennard-Jones model. Potential models including the octupole moment are shown to give a less adequate description of the liquid Carbonyl Sulphide.
Anna Troiani - One of the best experts on this subject based on the ideXlab platform.
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Ionization of Carbonyl Sulphide/disulphur monoxide mixtures in atmospheric gases: A theoretical study of the formation of S3O+ ions
Journal of Molecular Structure: THEOCHEM, 2020Co-Authors: Marzio Rosi, Giulia De Petris, Anna TroianiAbstract:A theoretical study performed at B3LYP and CCSD(T) level of theory of the reaction of formation Of S3O+ in ionized Carbonyl Sulphide/disulpbur monoxide mixtures is reported here. The interaction of Carbonyl Sulphide with disulphur monoxide cation leads to three different [CS3O2](+) isomers, essentially formed by a S3O+ cation solvated by a CO molecule. The S3O+ cation is present in the three structures cis, trans and ring, showed also by the isolated S3O+ species. The complex with the ring S3O+ unit is the most stable, but a direct ath to its formation starting from OCS and S2O+ has not been found in the potential energy surface Of [CS3O2]+. This species can be obtained from the isomerization of the complexes containing the cis or trans S3O+ unit, overcoming relatively low barrier heights. (C) 2007 Elsevier B.V. All rights reserved
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ionization of Carbonyl Sulphide disulphur monoxide mixtures in atmospheric gases a theoretical study of the formation of s3o ions
Journal of Molecular Structure-theochem, 2007Co-Authors: Marzio Rosi, Giulia De Petris, Anna TroianiAbstract:Abstract A theoretical study performed at B3LYP and CCSD(T) level of theory of the reaction of formation of S3O+ in ionized Carbonyl Sulphide/disulphur monoxide mixtures is reported here. The interaction of Carbonyl Sulphide with disulphur monoxide cation leads to three different [CS3O2]+ isomers, essentially formed by a S3O+ cation solvated by a CO molecule. The S3O+ cation is present in the three structures cis, trans and ring, showed also by the isolated S3O+ species. The complex with the ring S3O+ unit is the most stable, but a direct path to its formation starting from OCS and S2O+ has not been found in the potential energy surface of [CS3O2]+. This species can be obtained from the isomerization of the complexes containing the cis or trans S3O+ unit, overcoming relatively low barrier heights.
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Ionization of Carbonyl Sulphide/disulphur monoxide mixtures in atmospheric gases: A theoretical study of the formation of S3O+ ions
Journal of Molecular Structure-theochem, 2007Co-Authors: Marzio Rosi, Giulia De Petris, Anna TroianiAbstract:Abstract A theoretical study performed at B3LYP and CCSD(T) level of theory of the reaction of formation of S3O+ in ionized Carbonyl Sulphide/disulphur monoxide mixtures is reported here. The interaction of Carbonyl Sulphide with disulphur monoxide cation leads to three different [CS3O2]+ isomers, essentially formed by a S3O+ cation solvated by a CO molecule. The S3O+ cation is present in the three structures cis, trans and ring, showed also by the isolated S3O+ species. The complex with the ring S3O+ unit is the most stable, but a direct path to its formation starting from OCS and S2O+ has not been found in the potential energy surface of [CS3O2]+. This species can be obtained from the isomerization of the complexes containing the cis or trans S3O+ unit, overcoming relatively low barrier heights.
S A Montzka - One of the best experts on this subject based on the ideXlab platform.
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assessment of iasi capability for retrieving Carbonyl Sulphide ocs
Journal of Quantitative Spectroscopy & Radiative Transfer, 2017Co-Authors: C Camypeyret, Giuliano Liuzzi, Guido Masiello, Carmine Serio, Sara Venafra, S A MontzkaAbstract:Abstract The capability of IASI (Infrared Atmospheric Sounder Interferometer) for retrieving OCS has been assessed with a series of retrieval experiments, which have been carried out with a physical forward/inverse scheme, which can exploit the full IASI information content. We use random projections to reduce the dimensionality of the data space and to have a unified treatment of instrument and forward model errors. The OCS column amount is retrieved both by using a scaling parameterization of the profile and a non-parametric approach, in which we first derive the OCS profile and then its global amount is estimated by a proper integration over the profile. IASI OCS retrievals are compared to in situ flask observations at the Mauna Loa validation station, Hawaii, USA and observations from HIAPER Pole-to-Pole flights. We have found that the best way to retrieve OCS is through the non-parametric approach, which shows that the OCS cycle amplitude, phase and mean abundance can be retrieved with high accuracy for night and day time soundings. In fact, IASI captures the OCS seasonal cycle, with an overall difference with in situ observations, which is of the order of ≈ 1 pptv, provided we use HITRAN2012 OCS line compilation. HITRAN2008, which has been used in previous studies, is indeed affected by spectroscopic errors as far as OCS is concerned, which results in heavily biased OCS retrievals. Although the present paper is mostly intended to assess IASI retrievals over ocean, a demonstrative application to above land surface is considered as well. Preliminary results suggest that IASI can recover the OCS cycle in ecosystems governed by leaf and/or soil sources/sinks.
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ecosystem photosynthesis inferred from measurements of Carbonyl Sulphide flux
Nature Geoscience, 2013Co-Authors: David Asaf, Eyal Rotenberg, Fyodor Tatarinov, Uri Dicken, S A Montzka, Dan YakirAbstract:Carbonyl Sulphide is taken up by plants, and could potentially serve as a powerful proxy for photosynthetic carbon dioxide uptake. Field measurements in Israel suggest that Carbonyl Sulphide fluxes provide an independent constraint on indirect estimates of ecosystem photosynthesis.
H. Tost - One of the best experts on this subject based on the ideXlab platform.
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The role of Carbonyl Sulphide as a source of stratospheric sulphate aerosol and its impact on climate
Atmospheric Chemistry and Physics Discussions, 2011Co-Authors: C. Brühl, J. Lelieveld, P. J. Crutzen, H. TostAbstract:Abstract. Globally, Carbonyl Sulphide (COS) is the most abundant sulphur gas in the atmosphere. Our chemistry-climate model of the lower and middle atmosphere with aerosol module realistically simulates the background stratospheric sulphur cycle, as observed by satellites in volcanically quiescent periods. The model results indicate that upward transport of COS from the troposphere largely controls the sulphur budget and the aerosol loading of the background stratosphere. This differs from most previous studies which indicated that short-lived sulphur gases are also important. The model realistically simulates the modulation of the particulate and gaseous sulphur abundance in the stratosphere by the quasi-biennial oscillation (QBO). In the lowermost stratosphere organic carbon aerosol contributes significantly to extinction. Further, we compute that the radiative forcing efficiency by 1 kg of COS is 724 times that of 1 kg CO2, which translates into an overall radiative forcing by anthropogenic COS of 0.003 W m−2. The global warming potentials of COS over time horizons of 20 and 100 yr are GWP(20 yr) = 97 and GWP(100 yr) = 27, respectively (by mass). Furthermore, stratospheric aerosol particles produced by the photolysis of COS contribute to a negative radiative forcing, which amounts to −0.007 W m−2 at the top of the atmosphere for the anthropogenic fraction, more than two times the warming forcing of COS. Considering that the lifetime of COS is twice that of stratospheric aerosols the warming and cooling tendencies approximately cancel. If the forcing of the troposphere near the tropopause is considered, the cooling dominates.
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the role of Carbonyl Sulphide as a source of stratospheric sulphate aerosol and its impact on climate
Atmospheric Chemistry and Physics, 2011Co-Authors: C. Brühl, J. Lelieveld, P. J. Crutzen, H. TostAbstract:Abstract. Globally, Carbonyl Sulphide (COS) is the most abundant sulphur gas in the atmosphere. Our chemistry-climate model (CCM) of the lower and middle atmosphere with aerosol module realistically simulates the background stratospheric sulphur cycle, as observed by satellites in volcanically quiescent periods. The model results indicate that upward transport of COS from the troposphere largely controls the sulphur budget and the aerosol loading of the background stratosphere. This differs from most previous studies which indicated that short-lived sulphur gases are also important. The model realistically simulates the modulation of the particulate and gaseous sulphur abundance in the stratosphere by the quasi-biennial oscillation (QBO). In the lowermost stratosphere organic carbon aerosol contributes significantly to extinction. Further, using a chemical radiative convective model and recent spectra, we compute that the direct radiative forcing efficiency by 1 kg of COS is 724 times that of 1 kg CO 2 . Considering an anthropogenic fraction of 30% (derived from ice core data), this translates into an overall direct radiative forcing by COS of 0.003 W m −2 . The direct global warming potentials of COS over time horizons of 20 and 100 yr are GWP(20 yr) = 97 and GWP(100 yr) = 27, respectively (by mass). Furthermore, stratospheric aerosol particles produced by the photolysis of COS (chemical feedback) contribute to a negative direct solar radiative forcing, which in the CCM amounts to −0.007 W m −2 at the top of the atmosphere for the anthropogenic fraction, more than two times the direct warming forcing of COS. Considering that the lifetime of COS is twice that of stratospheric aerosols the warming and cooling tendencies approximately cancel.
S Jackson - One of the best experts on this subject based on the ideXlab platform.
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Carbonyl Sulphide adsorption on supported rhodium
Journal of Catalysis, 1990Co-Authors: S JacksonAbstract:Abstract The adsorption and thermal desorption of Carbonyl Sulphide on rhodium/silica have been studied. Three distinct forms of adsorbed Carbonyl Sulphide have been detected, at 293 K, using isotopically labeled carbon monoxide as a probe molecule. Thermal desorption resulted in dissociation of all adsorbed Carbonyl Sulphide and the subsequent desorption of carbon monoxide; no Carbonyl Sulphide was desorbed.