The Experts below are selected from a list of 1443 Experts worldwide ranked by ideXlab platform
Friedrich Kohler - One of the best experts on this subject based on the ideXlab platform.
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The temperature dependence of the isothermal Compressibility of Liquids along the orthobaric curve
Journal of Molecular Liquids, 1992Co-Authors: Friedrich KohlerAbstract:Abstract Correlations are presented for the reduced inverse Compressibility along the orthobaric curve. Special emphasis is placed on an one-parameter description, which allows the extrapolation of isothermal Compressibility to other temperatures, and where the one parameter gives an indication of the polarity of the liquid. Furthermore, the sensitivity of the one parameter to the value of the critical density can be used in turn as a check on this value.
Glenn Hefter - One of the best experts on this subject based on the ideXlab platform.
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The Compressibility of Liquids at ambient temperature and pressure
Journal of Molecular Liquids, 1997Co-Authors: Yizhak Marcus, Glenn HefterAbstract:Isothermal compressibilities, κT, at 298.15 K and ambient pressure were obtained from published sources for more than 150 Liquids of various functionality, either directly or via the adiabatic compressibilities, κS. They were related to other properties of these Liquids by means of a stepwise linear regression statistical program. A combination of the molar volume, the intrinsic volume, the isobaric expansibility, and the vapor pressure, with some structural features being taken into account, was able to explain ca. 95% of the variance of the data. This dependence was rationalized in terms of the void, compressible volumes in the Liquids. The predictive expression was applied to a further group of 40 common Liquids, for which no values of κT could be found.
Yizhak Marcus - One of the best experts on this subject based on the ideXlab platform.
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The Compressibility of Liquids at ambient temperature and pressure
Journal of Molecular Liquids, 1997Co-Authors: Yizhak Marcus, Glenn HefterAbstract:Isothermal compressibilities, κT, at 298.15 K and ambient pressure were obtained from published sources for more than 150 Liquids of various functionality, either directly or via the adiabatic compressibilities, κS. They were related to other properties of these Liquids by means of a stepwise linear regression statistical program. A combination of the molar volume, the intrinsic volume, the isobaric expansibility, and the vapor pressure, with some structural features being taken into account, was able to explain ca. 95% of the variance of the data. This dependence was rationalized in terms of the void, compressible volumes in the Liquids. The predictive expression was applied to a further group of 40 common Liquids, for which no values of κT could be found.
Georges Guiochon - One of the best experts on this subject based on the ideXlab platform.
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The use of syringe-type pumps in liquid chromatography in order to achieve a constant flow-rate
Journal of Chromatography A, 2001Co-Authors: Michel Martin, Gilbert Blu, Claude Eon, Georges GuiochonAbstract:Abstract The variation of the flow-rate of mobile phase pumped through a chromatographic column by a screw-driven syringe-type pump is discussed. It is shown that because of the Compressibility of Liquids, a steady-state flow is achieved only after a long period, which depends on the characteristics of the pump, the flow resistance of the column and the nature of the liquid. This period is normally between 15 and 60 min if liquid pumping starts from zero pressure at a constant piston speed. The retention times observed for compounds injected during the transitory period can be up to several times greater than those observed for the same compounds under steady-state conditions. All retention data and efficiencies measured during the transitory period are not reproducible and are meaningless. Quantitative results also are not reproducible. Instructions are given for the better use of this type of pump, which, in spite of some well-known advantages, has been found to be very difficult to use for any measurements.
Michel Martin - One of the best experts on this subject based on the ideXlab platform.
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The use of syringe-type pumps in liquid chromatography in order to achieve a constant flow-rate
Journal of Chromatography A, 2001Co-Authors: Michel Martin, Gilbert Blu, Claude Eon, Georges GuiochonAbstract:Abstract The variation of the flow-rate of mobile phase pumped through a chromatographic column by a screw-driven syringe-type pump is discussed. It is shown that because of the Compressibility of Liquids, a steady-state flow is achieved only after a long period, which depends on the characteristics of the pump, the flow resistance of the column and the nature of the liquid. This period is normally between 15 and 60 min if liquid pumping starts from zero pressure at a constant piston speed. The retention times observed for compounds injected during the transitory period can be up to several times greater than those observed for the same compounds under steady-state conditions. All retention data and efficiencies measured during the transitory period are not reproducible and are meaningless. Quantitative results also are not reproducible. Instructions are given for the better use of this type of pump, which, in spite of some well-known advantages, has been found to be very difficult to use for any measurements.