The Experts below are selected from a list of 237 Experts worldwide ranked by ideXlab platform

Tomoko Mizuguchi - One of the best experts on this subject based on the ideXlab platform.

  • Cavitation in thin films of amorphous polymers from the static melt induced by thermal treatment
    Polymer Journal, 2019
    Co-Authors: Masato Hashimoto, Susumu Fujiwara, Nozomi Katayama, Junki Ootani, Tomoko Mizuguchi
    Abstract:

    We discover a new cavitation phenomenon in amorphous polymers sandwiched between two thick slide glasses from the static melt induced by thermal treatment. By quenching atactic polystyrene samples from the static melt under the glass transition temperature ( T _g) and annealing them above T _g, cavities are created to relax the negative Pressure. Cavity growth undergoes an Ostwald ripening-like process in cases of large molecular weight while it undergoes a viscous fingering process in cases of small molecular weight. We discover a new cavitation phenomenon in amorphous polymers sandwiched between two thick slide glasses from the static melt induced by thermal treatment. By quenching atactic polystyrene (aPS) samples from the static melt under the glass transition temperature ( T _g) and annealing them above T _g for thick slide glasses, cavities are created to relax the negative Pressure. Cavity growth undergoes an Ostwald ripening-like process in cases of large molecular weight, while it undergoes a viscous fingering process in cases of small molecular weight. The induction time for Cavity formation is found to decrease with the increase of the annealing temperature and with the decrease of molecular weight. In contrast, no cavities are observed in an aPS sample between two thin cover glasses because the negative Pressure can be relaxed by bending the whole thin cover glasses.

  • Cavitation in thin films of amorphous polymers from the static melt induced by thermal treatment
    Polymer Journal, 2019
    Co-Authors: Masato Hashimoto, Susumu Fujiwara, Nozomi Katayama, Junki Ootani, Tomoko Mizuguchi
    Abstract:

    We discover a new cavitation phenomenon in amorphous polymers sandwiched between two thick slide glasses from the static melt induced by thermal treatment. By quenching atactic polystyrene (aPS) samples from the static melt under the glass transition temperature (Tg) and annealing them above Tg for thick slide glasses, cavities are created to relax the negative Pressure. Cavity growth undergoes an Ostwald ripening-like process in cases of large molecular weight, while it undergoes a viscous fingering process in cases of small molecular weight. The induction time for Cavity formation is found to decrease with the increase of the annealing temperature and with the decrease of molecular weight. In contrast, no cavities are observed in an aPS sample between two thin cover glasses because the negative Pressure can be relaxed by bending the whole thin cover glasses.

H Tran - One of the best experts on this subject based on the ideXlab platform.

  • high Pressure Cavity ring down spectroscopy application to the absorption continuum of co2 near 1 7µm
    Journal of Quantitative Spectroscopy & Radiative Transfer, 2015
    Co-Authors: S Kassi, A Campargue, D Mondelain, H Tran
    Abstract:

    Abstract A Cavity Ring Down Spectrometer has been developed for high sensitivity absorption spectroscopy in the near infrared at Pressure up to 10 bar. In order to strictly avoid perturbations of the optical alignment by Pressure forces, the pre-aligned CRDS Cavity is inserted inside the high Pressure cell. The stability of the spectra baseline has been validated by filling the CRDS cell with Ar and N2 up to 10 bar. We present here the first application of this CW-CRDS spectrometer to the study of the high Pressure spectrum of CO2 at room temperature. The spectra were recorded between 5850 and 5960 cm−1 for a series of Pressure values up to 6400 Torr. The studied spectral interval corresponds to the high energy range of the 1.75 µm transparency window of CO2 of particular interest for Venus. The CO2 absorption coefficient at a given Pressure value was obtained as the increase of the CRDS loss rate from its value at zero Pressure taking into account the small contribution due to Rayleigh scattering. The CO2 absorption spectrum includes the contribution of the self broadened local rovibrational lines together with a broad and weak continuum. The CO2 continuum was obtained as the difference of the CO2 absorption coefficient and of a local lines simulation using the CO2 HITRAN line list and a truncated Voigt profile. A quadratic Pressure dependence of the absorption continuum was observed, with an average binary absorption coefficient increasing smoothly from 3.7 to 11.5×10−9 cm−1 amagat−2 between 5850 and 5960 cm−1. The derived continuum shows a spectral feature located in the region of a band of 16O12C18O (present in natural abundance) which dominates the spectrum in the region. This spectral feature was found to arise from collisional interferences between local lines and quantitatively accounted for using a theoretical approach based on the impact and Energy Corrected Sudden (ECS) approximations. The impact of the chosen far wings CO2 line shape model on the retrieved continuum absorption is discussed.

Masato Hashimoto - One of the best experts on this subject based on the ideXlab platform.

  • Cavitation in thin films of amorphous polymers from the static melt induced by thermal treatment
    Polymer Journal, 2019
    Co-Authors: Masato Hashimoto, Susumu Fujiwara, Nozomi Katayama, Junki Ootani, Tomoko Mizuguchi
    Abstract:

    We discover a new cavitation phenomenon in amorphous polymers sandwiched between two thick slide glasses from the static melt induced by thermal treatment. By quenching atactic polystyrene samples from the static melt under the glass transition temperature ( T _g) and annealing them above T _g, cavities are created to relax the negative Pressure. Cavity growth undergoes an Ostwald ripening-like process in cases of large molecular weight while it undergoes a viscous fingering process in cases of small molecular weight. We discover a new cavitation phenomenon in amorphous polymers sandwiched between two thick slide glasses from the static melt induced by thermal treatment. By quenching atactic polystyrene (aPS) samples from the static melt under the glass transition temperature ( T _g) and annealing them above T _g for thick slide glasses, cavities are created to relax the negative Pressure. Cavity growth undergoes an Ostwald ripening-like process in cases of large molecular weight, while it undergoes a viscous fingering process in cases of small molecular weight. The induction time for Cavity formation is found to decrease with the increase of the annealing temperature and with the decrease of molecular weight. In contrast, no cavities are observed in an aPS sample between two thin cover glasses because the negative Pressure can be relaxed by bending the whole thin cover glasses.

  • Cavitation in thin films of amorphous polymers from the static melt induced by thermal treatment
    Polymer Journal, 2019
    Co-Authors: Masato Hashimoto, Susumu Fujiwara, Nozomi Katayama, Junki Ootani, Tomoko Mizuguchi
    Abstract:

    We discover a new cavitation phenomenon in amorphous polymers sandwiched between two thick slide glasses from the static melt induced by thermal treatment. By quenching atactic polystyrene (aPS) samples from the static melt under the glass transition temperature (Tg) and annealing them above Tg for thick slide glasses, cavities are created to relax the negative Pressure. Cavity growth undergoes an Ostwald ripening-like process in cases of large molecular weight, while it undergoes a viscous fingering process in cases of small molecular weight. The induction time for Cavity formation is found to decrease with the increase of the annealing temperature and with the decrease of molecular weight. In contrast, no cavities are observed in an aPS sample between two thin cover glasses because the negative Pressure can be relaxed by bending the whole thin cover glasses.

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

  • high Pressure Cavity ring down spectroscopy application to the absorption continuum of co2 near 1 7µm
    Journal of Quantitative Spectroscopy & Radiative Transfer, 2015
    Co-Authors: S Kassi, A Campargue, D Mondelain, H Tran
    Abstract:

    Abstract A Cavity Ring Down Spectrometer has been developed for high sensitivity absorption spectroscopy in the near infrared at Pressure up to 10 bar. In order to strictly avoid perturbations of the optical alignment by Pressure forces, the pre-aligned CRDS Cavity is inserted inside the high Pressure cell. The stability of the spectra baseline has been validated by filling the CRDS cell with Ar and N2 up to 10 bar. We present here the first application of this CW-CRDS spectrometer to the study of the high Pressure spectrum of CO2 at room temperature. The spectra were recorded between 5850 and 5960 cm−1 for a series of Pressure values up to 6400 Torr. The studied spectral interval corresponds to the high energy range of the 1.75 µm transparency window of CO2 of particular interest for Venus. The CO2 absorption coefficient at a given Pressure value was obtained as the increase of the CRDS loss rate from its value at zero Pressure taking into account the small contribution due to Rayleigh scattering. The CO2 absorption spectrum includes the contribution of the self broadened local rovibrational lines together with a broad and weak continuum. The CO2 continuum was obtained as the difference of the CO2 absorption coefficient and of a local lines simulation using the CO2 HITRAN line list and a truncated Voigt profile. A quadratic Pressure dependence of the absorption continuum was observed, with an average binary absorption coefficient increasing smoothly from 3.7 to 11.5×10−9 cm−1 amagat−2 between 5850 and 5960 cm−1. The derived continuum shows a spectral feature located in the region of a band of 16O12C18O (present in natural abundance) which dominates the spectrum in the region. This spectral feature was found to arise from collisional interferences between local lines and quantitatively accounted for using a theoretical approach based on the impact and Energy Corrected Sudden (ECS) approximations. The impact of the chosen far wings CO2 line shape model on the retrieved continuum absorption is discussed.

D. E. Tsygorov - One of the best experts on this subject based on the ideXlab platform.

  • Gases high purification from unreadily permeating impurities in one-compressor multistage membrane apparatuses
    Theoretical Foundations of Chemical Engineering, 2009
    Co-Authors: Vladimir M. Vorotyntsev, P. N. Drozdov, Ilya V. Vorotyntsev, D. E. Tsygorov
    Abstract:

    The present work is focused on gases high purification from unreadily permeating impurities by one-compressor multistage membrane apparatus (OMMA). It looks like a simple one way membrane cascade, consisting from several membrane modules with only one compressing point. In this operating regime the Pressure of high Pressure Cavity is decreasing from one to another while the concentration of high penetrating component is increasing. The equation of purification degree calculation was obtained. It shows how the impurity concentration of permeate reduces in comparison with initial concentration of flow (feed flow), incoming to the membrane module or apparatus. The equation for purification degree calculation was obtained. For the case of low impurity concentration there was leaded the comparison of calculated and experimental (from patent) data. The dependence of purification degree on the number of membrane modules composed apparatus which has an extremum was shown.

  • Gases high purification from unreadily permeating impurities in one-compressor multistage membrane apparatuses
    Theoretical Foundations of Chemical Engineering, 2009
    Co-Authors: Vladimir M. Vorotyntsev, P. N. Drozdov, Ilya V. Vorotyntsev, D. E. Tsygorov
    Abstract:

    The present work is focused on gases high purification from unreadily permeating impurities by one-compressor multistage membrane apparatus (OMMA). It looks like a simple one way membrane cascade, consisting from several membrane modules with only one compressing point. In this operating regime the Pressure of high Pressure Cavity is decreasing from one to another while the concentration of high penetrating component is increasing. The equation of purification degree calculation was obtained. It shows how the impurity concentration of permeate reduces in comparison with initial concentration of flow (feed flow), incoming to the membrane module or apparatus. The equation for purification degree calculation was obtained. For the case of low impurity concentration there was leaded the comparison of calculated and experimental (from patent) data. The dependence of purification degree on the number of membrane modules composed apparatus which has an extremum was shown. The description of one-compressor multistage membrane apparatus was determined. The equation of purification degree calculation was obtained. It shows how the impurity concentration of permeate reduces in comparison with initial concentration of flow (feed flow), incoming to the membrane module or apparatus. The equation for purification degree calculation was obtained. For the case of low impurity concentration there was leaded the comparison of calculated and experimental (from patent) data. The dependence of purification degree on the number of membrane modules composed apparatus was shown.