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Thierry Lasuye - One of the best experts on this subject based on the ideXlab platform.
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turbulent liquid liquid dispersion in smv static mixer at high dispersed Phase Concentration
Chemical Engineering Science, 2011Co-Authors: Emeline Lobry, Nathalie Le Sauze, Catherine Xuereb, Félicie Theron, Christophe Gourdon, Thierry LasuyeAbstract:The aim of this paper is to investigate the influence of physico-chemical parameters on liquid–liquid dispersion at high dispersed Phase Concentration in Sulzer SMV™ mixer. Four different oil-in-water systems involving two different surfactants are used in order to evaluate the effect of interfacial tension, densities and viscosities ratio on mean droplets size diameters. Moreover the influence of the dispersed Phase Concentration on the pressure drop as well as on the droplet size distribution is investigated. Two different droplets size distribution analysis techniques are used in order to compare the resulting Sauter mean diameters. The comparison between residence time in the mixer and surfactants adsorption kinetics leads to take into account the evolution of the interfacial tension between both Phases at short times. Finally experimental results are correlated as a function of dimensionless Reynolds and Weber numbers.
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Turbulent liquidâliquid dispersion in SMV static mixer at high dispersed Phase Concentration
Chemical Engineering Science, 2011Co-Authors: Emeline Lobry, Nathalie Le Sauze, Catherine Xuereb, Félicie Theron, Christophe Gourdon, Thierry LasuyeAbstract:The aim of this paper is to investigate the influence of physico-chemical parameters on liquidâliquid dispersion at high dispersed Phase Concentration in Sulzer SMV⢠mixer. Four different oil-in-water systems involving two different surfactants are used in order to evaluate the effect of interfacial tension, densities and viscosities ratio on mean droplets size diameters. Moreover the influence of the dispersed Phase Concentration on the pressure drop as well as on the droplet size distribution is investigated. Two different droplets size distribution analysis techniques are used in order to compare the resulting Sauter mean diameters. The comparison between residence time in the mixer and surfactants adsorption kinetics leads to take into account the evolution of the interfacial tension between both Phases at short times. Finally experimental results are correlated as a function of dimensionless Reynolds and Weber numbers.
Valérie Desauziers - One of the best experts on this subject based on the ideXlab platform.
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New sampling device for on-site measurement of SVOC gas-Phase Concentration at the emitting material surface
Analytical and Bioanalytical Chemistry, 2017Co-Authors: Mylène Ghislain, Joana Beigbeder, Hervé Plaisance, Valérie DesauziersAbstract:The gas-Phase Concentration at the material surface ( y _ 0 ) is pointed out in the literature as a key parameter to describe semivolatile organic compound (SVOC) emissions from materials. This is an important input data in predictive models of SVOC behavior indoors and risk exposure assessment. However, most of the existing measurement methods consist of determining emission rates and not y _ 0 and none allow on-site sampling. Hence, a new passive sampler was developed. It consists of a glass cell that is simply placed on the material surface until reaching equilibrium between material and air; y _ 0 is then determined by solid-Phase microextraction (SPME) sampling and GC-MS analysis. The limits of detection are at the μg/m^3 level and relative standard deviations (RSD) below 10%. A variation of 11% between two sets of experiments involving different cell volumes confirmed the y _ 0 measurement. In addition, due to the ability of SVOCs to be sorbed on surfaces, the cell wall/air partition was assessed by determining the inner cell surface Concentration of SVOCs, which is the Concentration of SVOCs adsorbed on the glass, and the cell surface/air partition coefficient ( K _ glass ). The recovery yields of the SVOCs sorbed on the cell walls are strongly compound-dependent and comprise between 2 and 93%. The K _ glass coefficients are found to be lower than the stainless steel/air partition coefficient ( K _ ss ), showing that glass is suitable for the SVOC sampling. This innovative tool opens up promising perspectives in terms of identification of SVOC sources and quantification of their emissions indoors, and would significantly contribute to human exposure assessment. Graphical Abstract Passive sampling for the determination of SVOCs Concentration at the material/air interface
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New sampling device for on-site measurement of SVOC gas-Phase Concentration at the emitting material surface
Analytical and bioanalytical chemistry, 2017Co-Authors: Mylène Ghislain, Joana Beigbeder, Hervé Plaisance, Valérie DesauziersAbstract:The gas-Phase Concentration at the material surface (y 0 ) is pointed out in the literature as a key parameter to describe semivolatile organic compound (SVOC) emissions from materials. This is an important input data in predictive models of SVOC behavior indoors and risk exposure assessment. However, most of the existing measurement methods consist of determining emission rates and not y 0 and none allow on-site sampling. Hence, a new passive sampler was developed. It consists of a glass cell that is simply placed on the material surface until reaching equilibrium between material and air; y 0 is then determined by solid-Phase microextraction (SPME) sampling and GC-MS analysis. The limits of detection are at the μg/m3 level and relative standard deviations (RSD) below 10%. A variation of 11% between two sets of experiments involving different cell volumes confirmed the y 0 measurement. In addition, due to the ability of SVOCs to be sorbed on surfaces, the cell wall/air partition was assessed by determining the inner cell surface Concentration of SVOCs, which is the Concentration of SVOCs adsorbed on the glass, and the cell surface/air partition coefficient (K glass ). The recovery yields of the SVOCs sorbed on the cell walls are strongly compound-dependent and comprise between 2 and 93%. The K glass coefficients are found to be lower than the stainless steel/air partition coefficient (K ss ), showing that glass is suitable for the SVOC sampling. This innovative tool opens up promising perspectives in terms of identification of SVOC sources and quantification of their emissions indoors, and would significantly contribute to human exposure assessment.
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formaldehyde emission behavior of building materials on site measurements and modeling approach to predict indoor air pollution
Journal of Hazardous Materials, 2014Co-Authors: Delphine Bourdin, Valérie Desauziers, Pierre Mocho, Hervé PlaisanceAbstract:The purpose of this paper was to investigate formaldehyde emission behavior of building materials from on-site measurements of air Phase Concentration at material surface used as input data of a box model to estimate the indoor air pollution of a newly built classroom. The relevance of this approach was explored using CFD modeling. In this box model, the contribution of building materials to indoor air pollution was estimated with two parameters: the convective mass transfer coefficient in the material/air boundary layer and the on-site measurements of gas Phase Concentration at material surfaces. An experimental method based on an emission test chamber was developed to quantify this convective mass transfer coefficient. The on-site measurement of gas Phase Concentration at material surface was measured by coupling a home-made sampler to SPME. First results had shown an accurate estimation of indoor formaldehyde Concentration in this classroom by using a simple box model.
Emeline Lobry - One of the best experts on this subject based on the ideXlab platform.
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turbulent liquid liquid dispersion in smv static mixer at high dispersed Phase Concentration
Chemical Engineering Science, 2011Co-Authors: Emeline Lobry, Nathalie Le Sauze, Catherine Xuereb, Félicie Theron, Christophe Gourdon, Thierry LasuyeAbstract:The aim of this paper is to investigate the influence of physico-chemical parameters on liquid–liquid dispersion at high dispersed Phase Concentration in Sulzer SMV™ mixer. Four different oil-in-water systems involving two different surfactants are used in order to evaluate the effect of interfacial tension, densities and viscosities ratio on mean droplets size diameters. Moreover the influence of the dispersed Phase Concentration on the pressure drop as well as on the droplet size distribution is investigated. Two different droplets size distribution analysis techniques are used in order to compare the resulting Sauter mean diameters. The comparison between residence time in the mixer and surfactants adsorption kinetics leads to take into account the evolution of the interfacial tension between both Phases at short times. Finally experimental results are correlated as a function of dimensionless Reynolds and Weber numbers.
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Turbulent liquidâliquid dispersion in SMV static mixer at high dispersed Phase Concentration
Chemical Engineering Science, 2011Co-Authors: Emeline Lobry, Nathalie Le Sauze, Catherine Xuereb, Félicie Theron, Christophe Gourdon, Thierry LasuyeAbstract:The aim of this paper is to investigate the influence of physico-chemical parameters on liquidâliquid dispersion at high dispersed Phase Concentration in Sulzer SMV⢠mixer. Four different oil-in-water systems involving two different surfactants are used in order to evaluate the effect of interfacial tension, densities and viscosities ratio on mean droplets size diameters. Moreover the influence of the dispersed Phase Concentration on the pressure drop as well as on the droplet size distribution is investigated. Two different droplets size distribution analysis techniques are used in order to compare the resulting Sauter mean diameters. The comparison between residence time in the mixer and surfactants adsorption kinetics leads to take into account the evolution of the interfacial tension between both Phases at short times. Finally experimental results are correlated as a function of dimensionless Reynolds and Weber numbers.
Hervé Plaisance - One of the best experts on this subject based on the ideXlab platform.
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New sampling device for on-site measurement of SVOC gas-Phase Concentration at the emitting material surface
Analytical and Bioanalytical Chemistry, 2017Co-Authors: Mylène Ghislain, Joana Beigbeder, Hervé Plaisance, Valérie DesauziersAbstract:The gas-Phase Concentration at the material surface ( y _ 0 ) is pointed out in the literature as a key parameter to describe semivolatile organic compound (SVOC) emissions from materials. This is an important input data in predictive models of SVOC behavior indoors and risk exposure assessment. However, most of the existing measurement methods consist of determining emission rates and not y _ 0 and none allow on-site sampling. Hence, a new passive sampler was developed. It consists of a glass cell that is simply placed on the material surface until reaching equilibrium between material and air; y _ 0 is then determined by solid-Phase microextraction (SPME) sampling and GC-MS analysis. The limits of detection are at the μg/m^3 level and relative standard deviations (RSD) below 10%. A variation of 11% between two sets of experiments involving different cell volumes confirmed the y _ 0 measurement. In addition, due to the ability of SVOCs to be sorbed on surfaces, the cell wall/air partition was assessed by determining the inner cell surface Concentration of SVOCs, which is the Concentration of SVOCs adsorbed on the glass, and the cell surface/air partition coefficient ( K _ glass ). The recovery yields of the SVOCs sorbed on the cell walls are strongly compound-dependent and comprise between 2 and 93%. The K _ glass coefficients are found to be lower than the stainless steel/air partition coefficient ( K _ ss ), showing that glass is suitable for the SVOC sampling. This innovative tool opens up promising perspectives in terms of identification of SVOC sources and quantification of their emissions indoors, and would significantly contribute to human exposure assessment. Graphical Abstract Passive sampling for the determination of SVOCs Concentration at the material/air interface
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New sampling device for on-site measurement of SVOC gas-Phase Concentration at the emitting material surface
Analytical and bioanalytical chemistry, 2017Co-Authors: Mylène Ghislain, Joana Beigbeder, Hervé Plaisance, Valérie DesauziersAbstract:The gas-Phase Concentration at the material surface (y 0 ) is pointed out in the literature as a key parameter to describe semivolatile organic compound (SVOC) emissions from materials. This is an important input data in predictive models of SVOC behavior indoors and risk exposure assessment. However, most of the existing measurement methods consist of determining emission rates and not y 0 and none allow on-site sampling. Hence, a new passive sampler was developed. It consists of a glass cell that is simply placed on the material surface until reaching equilibrium between material and air; y 0 is then determined by solid-Phase microextraction (SPME) sampling and GC-MS analysis. The limits of detection are at the μg/m3 level and relative standard deviations (RSD) below 10%. A variation of 11% between two sets of experiments involving different cell volumes confirmed the y 0 measurement. In addition, due to the ability of SVOCs to be sorbed on surfaces, the cell wall/air partition was assessed by determining the inner cell surface Concentration of SVOCs, which is the Concentration of SVOCs adsorbed on the glass, and the cell surface/air partition coefficient (K glass ). The recovery yields of the SVOCs sorbed on the cell walls are strongly compound-dependent and comprise between 2 and 93%. The K glass coefficients are found to be lower than the stainless steel/air partition coefficient (K ss ), showing that glass is suitable for the SVOC sampling. This innovative tool opens up promising perspectives in terms of identification of SVOC sources and quantification of their emissions indoors, and would significantly contribute to human exposure assessment.
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formaldehyde emission behavior of building materials on site measurements and modeling approach to predict indoor air pollution
Journal of Hazardous Materials, 2014Co-Authors: Delphine Bourdin, Valérie Desauziers, Pierre Mocho, Hervé PlaisanceAbstract:The purpose of this paper was to investigate formaldehyde emission behavior of building materials from on-site measurements of air Phase Concentration at material surface used as input data of a box model to estimate the indoor air pollution of a newly built classroom. The relevance of this approach was explored using CFD modeling. In this box model, the contribution of building materials to indoor air pollution was estimated with two parameters: the convective mass transfer coefficient in the material/air boundary layer and the on-site measurements of gas Phase Concentration at material surfaces. An experimental method based on an emission test chamber was developed to quantify this convective mass transfer coefficient. The on-site measurement of gas Phase Concentration at material surface was measured by coupling a home-made sampler to SPME. First results had shown an accurate estimation of indoor formaldehyde Concentration in this classroom by using a simple box model.
Peter Slegel - One of the best experts on this subject based on the ideXlab platform.
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new chromatographic hydrophobicity index ϕ0 based on the slope and the intercept of the log k versus organic Phase Concentration plot
Journal of Chromatography A, 1993Co-Authors: Klara Valko, Peter SlegelAbstract:Abstract A new chromatographic hydrophobicity index (ϕ 0 ) is suggested as a measure of the lipophilic character of compounds in reversed-Phase high-performance liquid chromatography (RP-HPLC). The parameter ϕ 0 is defined as the organic Phase Concentration (methanol or acetonitrile) in the mobile Phase which is required for log k ′ = 0 (retention time is double the dead time), that is, the molar fraction of the compound is identical in the mobile and the stationary Phases. The ϕ 0 values therefore range from 0 to 100%, and the higher the value the more hydrophobic is the compound. It is shown that the value of ϕ 0 is characteristic for a compound and depends only on the type of organic modifier, pH and temperature. It is independent of the RP column type and length, flow-rate and the mobile Phase compositions where the actual retention measurements are carried out. The other advantages of ϕ 0 are that it can be precisely measured, as it has a concrete physical meaning, namely the organic Phase Concentration of the mobile Phase at which the retention time is exactly double the dead time (not like log k ′ values extrapolated to water as mobile Phase), and it is independent of the linear or quadratic function of the log k ′ versus ϕ 0 relationships. The ϕ 0 values not only reflect the hydrophobic character of compounds but also provide a valuable means for method development in RP-HPLC as they reveal a mobile Phase composition with known retention time values. The ϕ 0 values for over 500 compounds were calculated and are presented on the basis of their published retention data. The ϕ 0 values obtained with methanol and acetonitrile showed an excellent correlation with each other. Significant correlations were found between the ϕ 0 values and the logarithm of 1-octanol—water partition coefficients (log P ).
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New chromatographic hydrophobicity index (ϕ0) based on the slope and the intercept of the log k′ versus organic Phase Concentration plot
Journal of Chromatography A, 1993Co-Authors: Klara Valko, Peter SlegelAbstract:Abstract A new chromatographic hydrophobicity index (ϕ 0 ) is suggested as a measure of the lipophilic character of compounds in reversed-Phase high-performance liquid chromatography (RP-HPLC). The parameter ϕ 0 is defined as the organic Phase Concentration (methanol or acetonitrile) in the mobile Phase which is required for log k ′ = 0 (retention time is double the dead time), that is, the molar fraction of the compound is identical in the mobile and the stationary Phases. The ϕ 0 values therefore range from 0 to 100%, and the higher the value the more hydrophobic is the compound. It is shown that the value of ϕ 0 is characteristic for a compound and depends only on the type of organic modifier, pH and temperature. It is independent of the RP column type and length, flow-rate and the mobile Phase compositions where the actual retention measurements are carried out. The other advantages of ϕ 0 are that it can be precisely measured, as it has a concrete physical meaning, namely the organic Phase Concentration of the mobile Phase at which the retention time is exactly double the dead time (not like log k ′ values extrapolated to water as mobile Phase), and it is independent of the linear or quadratic function of the log k ′ versus ϕ 0 relationships. The ϕ 0 values not only reflect the hydrophobic character of compounds but also provide a valuable means for method development in RP-HPLC as they reveal a mobile Phase composition with known retention time values. The ϕ 0 values for over 500 compounds were calculated and are presented on the basis of their published retention data. The ϕ 0 values obtained with methanol and acetonitrile showed an excellent correlation with each other. Significant correlations were found between the ϕ 0 values and the logarithm of 1-octanol—water partition coefficients (log P ).