The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform

Alexander Toikka - One of the best experts on this subject based on the ideXlab platform.

  • Chemical Equilibrium for the reactive system propionic acid + ethanol + ethyl propionate + water at 303.15 and 313.15 K
    Fluid Phase Equilibria, 2017
    Co-Authors: Maria Toikka, Alexandra Golikova, Artemiy Samarov, Maya Trofimova, Anna Sadaeva, Nataliya Shcherbakova, Alexander Toikka
    Abstract:

    Chemical Equilibrium for the quaternary system propionic acid+ethanol+ethyl propionate +water was experimentally studied at 303.15 and 313.15 K and atmospheric pressure. The Chemically Equilibrium compositions were determined by gas chromatography and nuclear magnetic resonance analytical methods. It is shown that Chemical Equilibrium is reached both in homogeneous and heterogeneous area of composition of reactive mixture. The liquid - liquid Equilibrium data for the surface of Chemical Equilibrium were obtained. The thermodynamic constants of Chemical Equilibrium at 303.15 and 313.15 K were determined.

  • Chemical Equilibrium for the reactive system propionic acid ethanol ethyl propionate water at 303 15 and 313 15 k
    Fluid Phase Equilibria, 2017
    Co-Authors: Maria Toikka, Alexandra Golikova, Artemiy Samarov, Maya Trofimova, Anna Sadaeva, Nataliya Shcherbakova, Alexander Toikka
    Abstract:

    Abstract Chemical Equilibrium for the quaternary system propionic acid + ethanol + ethyl propionate + water was experimentally studied at 303.15 and 313.15 K and atmospheric pressure. The Chemically Equilibrium compositions were determined by gas chromatography and nuclear magnetic resonance analytical methods. It is shown that Chemical Equilibrium is reached both in homogeneous and heterogeneous area of composition of reactive mixture. The liquid – liquid Equilibrium data for the surface of Chemical Equilibrium were obtained. The thermodynamic constants of Chemical Equilibrium at 303.15 and 313.15 K were determined.

  • Chemical Equilibrium for the reacting system acetic acid ethanol ethyl acetate water at 303 15 k 313 15 k and 323 15 k
    Journal of Solution Chemistry, 2017
    Co-Authors: Alexandra Golikova, Artemiy Samarov, Maya Trofimova, Sevastyan O. Rabdano, Maria Toikka, Oleg Pervukhin, Alexander Toikka
    Abstract:

    The Chemical Equilibrium (CE) for the quaternary reacting system ethanol–acetic acid–ethyl acetate–water was studied at 303.15, 313.15 and 323.15 K and atmospheric pressure. The CE compositions were determined by gas chromatography and nuclear magnetic resonance analytical methods. The thermodynamic constants of CE at 303.15, 313.15 and 323.15 K were calculated based on the obtained experimental data with the use of the NRTL model.

Gregory J. Herczeg - One of the best experts on this subject based on the ideXlab platform.

  • The Effects of UV Continuum and Lyman alpha Radiation on the Chemical Equilibrium of T Tauri Disks
    The Astrophysical Journal, 2003
    Co-Authors: Edwin A Bergin, Nuria Calvet, Paola D'alessio, Gregory J. Herczeg
    Abstract:

    We show in this Letter that the spectral details of the FUV radiation fields have a large impact on the chemistry of protoplanetary disks surrounding T Tauri stars. We show that the strength of a realistic stellar FUV field is significantly lower than typically assumed in Chemical calculations and that the radiation field is dominated by strong line emission, most notably Lyman alpha radiation. The effects of the strong Lyman alpha emission on the Chemical Equilibrium in protoplanetary disks has previously been unrecognized. We discuss the impact of this radiation on molecular observations in the context of a radiative transfer model that includes both direct attenuation and scattering. In particular, Lyman alpha radiation will directly dissociate water vapor and may contribute to the observed enhancements of CN/HCN in disks.

  • the effects of uv continuum and lyα radiation on the Chemical Equilibrium of t tauri disks
    The Astrophysical Journal, 2003
    Co-Authors: Edwin A Bergin, Nuria Calvet, Paola Dalessio, Gregory J. Herczeg
    Abstract:

    We show in this Letter that the spectral details of the far-ultraviolet (FUV) radiation fields have a large impact on the chemistry of protoplanetary disks surrounding T Tauri stars. We show that the strength of a realistic stellar FUV field is significantly lower than typically assumed in Chemical calculations and that the radiation field is dominated by strong line emission, most notably Lyα radiation. The effects of the strong Lyα emission on the Chemical Equilibrium in protoplanetary disks have previously been unrecognized. We discuss the impact of this radiation on molecular observations in the context of a radiative transfer model that includes both direct attenuation and scattering. In particular, Lyα radiation will directly dissociate water vapor and may contribute to the observed enhancements of CN/HCN in disks.

Maria Toikka - One of the best experts on this subject based on the ideXlab platform.

  • Chemical Equilibrium for the reactive system propionic acid + ethanol + ethyl propionate + water at 303.15 and 313.15 K
    Fluid Phase Equilibria, 2017
    Co-Authors: Maria Toikka, Alexandra Golikova, Artemiy Samarov, Maya Trofimova, Anna Sadaeva, Nataliya Shcherbakova, Alexander Toikka
    Abstract:

    Chemical Equilibrium for the quaternary system propionic acid+ethanol+ethyl propionate +water was experimentally studied at 303.15 and 313.15 K and atmospheric pressure. The Chemically Equilibrium compositions were determined by gas chromatography and nuclear magnetic resonance analytical methods. It is shown that Chemical Equilibrium is reached both in homogeneous and heterogeneous area of composition of reactive mixture. The liquid - liquid Equilibrium data for the surface of Chemical Equilibrium were obtained. The thermodynamic constants of Chemical Equilibrium at 303.15 and 313.15 K were determined.

  • Chemical Equilibrium for the reactive system propionic acid ethanol ethyl propionate water at 303 15 and 313 15 k
    Fluid Phase Equilibria, 2017
    Co-Authors: Maria Toikka, Alexandra Golikova, Artemiy Samarov, Maya Trofimova, Anna Sadaeva, Nataliya Shcherbakova, Alexander Toikka
    Abstract:

    Abstract Chemical Equilibrium for the quaternary system propionic acid + ethanol + ethyl propionate + water was experimentally studied at 303.15 and 313.15 K and atmospheric pressure. The Chemically Equilibrium compositions were determined by gas chromatography and nuclear magnetic resonance analytical methods. It is shown that Chemical Equilibrium is reached both in homogeneous and heterogeneous area of composition of reactive mixture. The liquid – liquid Equilibrium data for the surface of Chemical Equilibrium were obtained. The thermodynamic constants of Chemical Equilibrium at 303.15 and 313.15 K were determined.

  • Chemical Equilibrium for the reacting system acetic acid ethanol ethyl acetate water at 303 15 k 313 15 k and 323 15 k
    Journal of Solution Chemistry, 2017
    Co-Authors: Alexandra Golikova, Artemiy Samarov, Maya Trofimova, Sevastyan O. Rabdano, Maria Toikka, Oleg Pervukhin, Alexander Toikka
    Abstract:

    The Chemical Equilibrium (CE) for the quaternary reacting system ethanol–acetic acid–ethyl acetate–water was studied at 303.15, 313.15 and 323.15 K and atmospheric pressure. The CE compositions were determined by gas chromatography and nuclear magnetic resonance analytical methods. The thermodynamic constants of CE at 303.15, 313.15 and 323.15 K were calculated based on the obtained experimental data with the use of the NRTL model.

Richard S Freedman - One of the best experts on this subject based on the ideXlab platform.

  • ammonia as a tracer of Chemical Equilibrium in the t7 5 dwarf gliese 570d
    The Astrophysical Journal, 2006
    Co-Authors: D Saumon, Mark S Marley, Michael C Cushing, S K Leggett, Thomas L Roellig, Katharina Lodders, Richard S Freedman
    Abstract:

    We present the first analysis of an optical to mid-infrared spectrum of the T7.5 dwarf Gliese 570D with model atmospheres, synthetic spectra, and brown dwarf evolution sequences. We obtain precise values for the basic parameters of Gl 570D: Teff = 800-820 K, log g (cm s-2) = 5.09-5.23, and log = -5.525 to -5.551. The Spitzer Infrared Spectrograph (IRS) spectrum shows prominent features of ammonia (NH3) that can only be fitted by reducing the abundance of NH3 by about 1 order of magnitude from the value obtained with Chemical-Equilibrium models. We model departures from Chemical Equilibrium in the atmosphere of Gl 570D by considering the kinetics of nitrogen and carbon chemistry in the presence of vertical mixing. The resulting model spectrum reproduces the data very well.

  • ammonia as a tracer of Chemical Equilibrium in the t7 5 dwarf gliese 570d
    arXiv: Astrophysics, 2006
    Co-Authors: D Saumon, Mark S Marley, Michael C Cushing, S K Leggett, Thomas L Roellig, Katharina Lodders, Richard S Freedman
    Abstract:

    We present the first analysis of an optical to mid-infrared spectrum of the T7.5 dwarf Gliese 570D with model atmospheres, synthetic spectra, and brown dwarf evolution sequences. We obtain precise values for the basic parameters of Gl 570D: Teff=800 - 820K, log g (cm/s^2)=5.09 - 5.23, and log L/Lsun= -5.525 to -5.551. The Spitzer IRS spectrum shows prominent features of ammonia (NH3) that can only be fitted by reducing the abundance of NH3 by about one order of magnitude from the value obtained with Chemical Equilibrium models. We model departures from Chemical Equilibrium in the atmosphere of Gl 570D by considering the kinetics of nitrogen and carbon chemistry in the presence of vertical mixing. The resulting model spectrum reproduces the data very well.

Edwin A Bergin - One of the best experts on this subject based on the ideXlab platform.

  • The Effects of UV Continuum and Lyman alpha Radiation on the Chemical Equilibrium of T Tauri Disks
    The Astrophysical Journal, 2003
    Co-Authors: Edwin A Bergin, Nuria Calvet, Paola D'alessio, Gregory J. Herczeg
    Abstract:

    We show in this Letter that the spectral details of the FUV radiation fields have a large impact on the chemistry of protoplanetary disks surrounding T Tauri stars. We show that the strength of a realistic stellar FUV field is significantly lower than typically assumed in Chemical calculations and that the radiation field is dominated by strong line emission, most notably Lyman alpha radiation. The effects of the strong Lyman alpha emission on the Chemical Equilibrium in protoplanetary disks has previously been unrecognized. We discuss the impact of this radiation on molecular observations in the context of a radiative transfer model that includes both direct attenuation and scattering. In particular, Lyman alpha radiation will directly dissociate water vapor and may contribute to the observed enhancements of CN/HCN in disks.

  • the effects of uv continuum and lyα radiation on the Chemical Equilibrium of t tauri disks
    The Astrophysical Journal, 2003
    Co-Authors: Edwin A Bergin, Nuria Calvet, Paola Dalessio, Gregory J. Herczeg
    Abstract:

    We show in this Letter that the spectral details of the far-ultraviolet (FUV) radiation fields have a large impact on the chemistry of protoplanetary disks surrounding T Tauri stars. We show that the strength of a realistic stellar FUV field is significantly lower than typically assumed in Chemical calculations and that the radiation field is dominated by strong line emission, most notably Lyα radiation. The effects of the strong Lyα emission on the Chemical Equilibrium in protoplanetary disks have previously been unrecognized. We discuss the impact of this radiation on molecular observations in the context of a radiative transfer model that includes both direct attenuation and scattering. In particular, Lyα radiation will directly dissociate water vapor and may contribute to the observed enhancements of CN/HCN in disks.