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M. Vauclin - One of the best experts on this subject based on the ideXlab platform.

  • isotopic composition of bare soil Evaporated Water vapor part i rubic iv experimental setup and results
    Journal of Hydrology, 2009
    Co-Authors: I. Braud, P. Biron, T. Bariac, L. Canale, Patricia Richard, Jeanpaul Gaudet, M. Vauclin
    Abstract:

    Stable Water isotopes such as oxygen 18, are natural tracers of Water movement within the soilvegetationatmosphere continuum. They provide useful information for a better understanding of evaporation and Water vapor transport within soils. This paper presents a novel controlled experimental set up. It is dedicated to detailed measurements of the evaporation fluxes from bare soil columns, as well as to the corresponding isotopic composition of the Water vapor, under non steady state conditions. The experiment allowed an accurate determination of these quantities. The formulae encountered in the literature were used to estimate the isotopic composition of the Evaporated Water vapor. None of them was able to correctly reproduce the measured isotopic composition of Water. The data were then used to estimate the value of the isotopic composition of the soil liquid Water, which should be used to get the right results for the isotopic composition of the Evaporated Water vapor. Results suggest that, when liquid transfer is dominant within the soil, the isotopic composition of evaporation was controlled by the isotopic composition of the liquid Water within very thin soil surface layers. When there is a peak in the isotopic profile, i.e. when Water vapor is dominant close to the surface, the isotopic composition of the Evaporated Water seems to be governed by the isotopic composition of the soil liquid Water at the peak. The data were also used to estimate the kinetic fractionation factor. The results suggest that the latter is not constant in time. The values seem to depend on the shape of the isotopic profile. In both cases, the uncertainty on the results is very large. The estimation of the kinetic fractionation factor is studied more in details using the modeling results presented in Part II of a companion paper where the data set is modeled using the SiSPAT_Isotope model.

  • Isotopic composition of bare soil Evaporated Water vapor. Part I: RUBIC IV experimental set up and results
    Journal of Hydrology, 2009
    Co-Authors: I. Braud, P. Biron, T. Bariac, Patrick Richard, L. Canale, J.p. Gaudet, M. Vauclin
    Abstract:

    Stable Water isotopes such as oxygen 18, are natural tracers of Water movement within the soilvegetationatmosphere continuum. They provide useful information for a better understanding of evaporation and Water vapor transport within soils. This paper presents a novel controlled experimental set up. It is dedicated to detailed measurements of the evaporation fluxes from bare soil columns, as well as to the corresponding isotopic composition of the Water vapor, under non steady state conditions. The experiment allowed an accurate determination of these quantities. The formulae encountered in the literature were used to estimate the isotopic composition of the Evaporated Water vapor. None of them was able to correctly reproduce the measured isotopic composition of Water. The data were then used to estimate the value of the isotopic composition of the soil liquid Water, which should be used to get the right results for the isotopic composition of the Evaporated Water vapor. Results suggest that, when liquid transfer is dominant within the soil, the isotopic composition of evaporation was controlled by the isotopic composition of the liquid Water within very thin soil surface layers. When there is a peak in the isotopic profile, i.e. when Water vapor is dominant close to the surface, the isotopic composition of the Evaporated Water seems to be governed by the isotopic composition of the soil liquid Water at the peak. The data were also used to estimate the kinetic fractionation factor. The results suggest that the latter is not constant in time. The values seem to depend on the shape of the isotopic profile. In both cases, the uncertainty on the results is very large. The estimation of the kinetic fractionation factor is studied more in details using the modeling results presented in Part II of a companion paper where the data set is modeled using the SiSPAT_Isotope model.

  • Isotopic composition of bare soil Evaporated Water vapor. Part II: Modeling of RUBIC IV experimental results.
    Journal of Hydrology, 2009
    Co-Authors: P. Biron, M. Vauclin
    Abstract:

    Stable Water isotopes such as oxygen 18, are natural tracers of Water movement within the soil-vegetation-atmosphere continuum. They provide useful information for a better understanding of evaporation and Water vapor transport within soils. This paper presents a novel controlled experimental setup. It is dedicated to detailed measurements of the evaporation fluxes from bare soil columns, as well as to the corresponding isotopic composition of the Water vapor, under non-steady state conditions. The experiment allowed an accurate determination of these quantities. The formulae encountered in the literature were used to estimate the isotopic composition of the Evaporated Water vapor. None of them was able to correctly reproduce the measured isotopic composition of Water. The data were then used to estimate the value of the isotopic composition of the soil liquid Water. which should be used to get the right results for the isotopic composition of the Evaporated Water vapor. Results suggest that, when liquid transfer is dominant within the soil, the isotopic composition of evaporation was controlled by the isotopic composition of the liquid Water within very thin soil surface layers. When there is a peak in the isotopic profile, i.e. when Water vapor is dominant close to the surface, the isotopic composition of the Evaporated Water seems to be governed by the isotopic composition of the soil liquid Water at the peak. The data were also used to estimate the kinetic fractionation factor. The results suggest that the latter is not constant in time. The values seem to depend on the shape of the isotopic profile. In both cases, the uncertainty on the results is very large. The estimation of the kinetic fractionation factor is Studied more in details using the modeling results presented in Part II of a companion paper where the data set is modeled using the SiSPAT_Isotope model.

  • Isotopic composition of bare soil Evaporated Water vapor. Part II: Modeling of RUBIC IV experimental results
    Journal of Hydrology, 2009
    Co-Authors: I. Braud, P. Biron, T. Bariac, M. Vauclin
    Abstract:

    Stable Water isotopes such as oxygen 18, are tracers of Water movement within the soil vegetation atmosphere system. They provide useful information for a better understanding of evaporation and Water vapor transport within soils. In part I of this paper, we presented a novel control experimental set up under non steady conditions, dedicated to the measurement of the evaporation flux and corresponding isotopic composition from six bare soil columns. Data analysis raised several questions about the soil depth controlling the isotopic composition of the Evaporated Water vapor, suggesting different behavior before and after the appearance of back diffusion. Experimental data also suggested a time variable value of the kinetic fractionation factor. The present paper presents the modeling of the experimental results using the coupled heat, Water and stable isotope transfer model SiSPAT_Isotope. Model results were used for investigating the above questions more in details. For this purpose, model parameters were calibrated for each soil column in order to reproduce the data. Then model results were inverted to estimate the kinetic fractionation factor. The results show that the hypothesis that the kinetic fractionation factor varies in time is plausible but the uncertainty is too large to derive firm conclusions. The largest uncertainty is found when the soil relative humidity is lower than one but Water vapor is still negligible. When back diffusion has occurred, model results are the most robust and confirm that the isotopic composition of the Evaporated Water vapor is controlled by the soil isotopic composition of the liquid Water at the peak. In this case, the retrieved kinetic fractionation factor is close to 18.9°/°°, corresponding to laminar flow.

P. Biron - One of the best experts on this subject based on the ideXlab platform.

  • isotopic composition of bare soil Evaporated Water vapor part i rubic iv experimental setup and results
    Journal of Hydrology, 2009
    Co-Authors: I. Braud, P. Biron, T. Bariac, L. Canale, Patricia Richard, Jeanpaul Gaudet, M. Vauclin
    Abstract:

    Stable Water isotopes such as oxygen 18, are natural tracers of Water movement within the soilvegetationatmosphere continuum. They provide useful information for a better understanding of evaporation and Water vapor transport within soils. This paper presents a novel controlled experimental set up. It is dedicated to detailed measurements of the evaporation fluxes from bare soil columns, as well as to the corresponding isotopic composition of the Water vapor, under non steady state conditions. The experiment allowed an accurate determination of these quantities. The formulae encountered in the literature were used to estimate the isotopic composition of the Evaporated Water vapor. None of them was able to correctly reproduce the measured isotopic composition of Water. The data were then used to estimate the value of the isotopic composition of the soil liquid Water, which should be used to get the right results for the isotopic composition of the Evaporated Water vapor. Results suggest that, when liquid transfer is dominant within the soil, the isotopic composition of evaporation was controlled by the isotopic composition of the liquid Water within very thin soil surface layers. When there is a peak in the isotopic profile, i.e. when Water vapor is dominant close to the surface, the isotopic composition of the Evaporated Water seems to be governed by the isotopic composition of the soil liquid Water at the peak. The data were also used to estimate the kinetic fractionation factor. The results suggest that the latter is not constant in time. The values seem to depend on the shape of the isotopic profile. In both cases, the uncertainty on the results is very large. The estimation of the kinetic fractionation factor is studied more in details using the modeling results presented in Part II of a companion paper where the data set is modeled using the SiSPAT_Isotope model.

  • Isotopic composition of bare soil Evaporated Water vapor. Part I: RUBIC IV experimental set up and results
    Journal of Hydrology, 2009
    Co-Authors: I. Braud, P. Biron, T. Bariac, Patrick Richard, L. Canale, J.p. Gaudet, M. Vauclin
    Abstract:

    Stable Water isotopes such as oxygen 18, are natural tracers of Water movement within the soilvegetationatmosphere continuum. They provide useful information for a better understanding of evaporation and Water vapor transport within soils. This paper presents a novel controlled experimental set up. It is dedicated to detailed measurements of the evaporation fluxes from bare soil columns, as well as to the corresponding isotopic composition of the Water vapor, under non steady state conditions. The experiment allowed an accurate determination of these quantities. The formulae encountered in the literature were used to estimate the isotopic composition of the Evaporated Water vapor. None of them was able to correctly reproduce the measured isotopic composition of Water. The data were then used to estimate the value of the isotopic composition of the soil liquid Water, which should be used to get the right results for the isotopic composition of the Evaporated Water vapor. Results suggest that, when liquid transfer is dominant within the soil, the isotopic composition of evaporation was controlled by the isotopic composition of the liquid Water within very thin soil surface layers. When there is a peak in the isotopic profile, i.e. when Water vapor is dominant close to the surface, the isotopic composition of the Evaporated Water seems to be governed by the isotopic composition of the soil liquid Water at the peak. The data were also used to estimate the kinetic fractionation factor. The results suggest that the latter is not constant in time. The values seem to depend on the shape of the isotopic profile. In both cases, the uncertainty on the results is very large. The estimation of the kinetic fractionation factor is studied more in details using the modeling results presented in Part II of a companion paper where the data set is modeled using the SiSPAT_Isotope model.

  • Isotopic composition of bare soil Evaporated Water vapor. Part II: Modeling of RUBIC IV experimental results.
    Journal of Hydrology, 2009
    Co-Authors: P. Biron, M. Vauclin
    Abstract:

    Stable Water isotopes such as oxygen 18, are natural tracers of Water movement within the soil-vegetation-atmosphere continuum. They provide useful information for a better understanding of evaporation and Water vapor transport within soils. This paper presents a novel controlled experimental setup. It is dedicated to detailed measurements of the evaporation fluxes from bare soil columns, as well as to the corresponding isotopic composition of the Water vapor, under non-steady state conditions. The experiment allowed an accurate determination of these quantities. The formulae encountered in the literature were used to estimate the isotopic composition of the Evaporated Water vapor. None of them was able to correctly reproduce the measured isotopic composition of Water. The data were then used to estimate the value of the isotopic composition of the soil liquid Water. which should be used to get the right results for the isotopic composition of the Evaporated Water vapor. Results suggest that, when liquid transfer is dominant within the soil, the isotopic composition of evaporation was controlled by the isotopic composition of the liquid Water within very thin soil surface layers. When there is a peak in the isotopic profile, i.e. when Water vapor is dominant close to the surface, the isotopic composition of the Evaporated Water seems to be governed by the isotopic composition of the soil liquid Water at the peak. The data were also used to estimate the kinetic fractionation factor. The results suggest that the latter is not constant in time. The values seem to depend on the shape of the isotopic profile. In both cases, the uncertainty on the results is very large. The estimation of the kinetic fractionation factor is Studied more in details using the modeling results presented in Part II of a companion paper where the data set is modeled using the SiSPAT_Isotope model.

  • Isotopic composition of bare soil Evaporated Water vapor. Part II: Modeling of RUBIC IV experimental results
    Journal of Hydrology, 2009
    Co-Authors: I. Braud, P. Biron, T. Bariac, M. Vauclin
    Abstract:

    Stable Water isotopes such as oxygen 18, are tracers of Water movement within the soil vegetation atmosphere system. They provide useful information for a better understanding of evaporation and Water vapor transport within soils. In part I of this paper, we presented a novel control experimental set up under non steady conditions, dedicated to the measurement of the evaporation flux and corresponding isotopic composition from six bare soil columns. Data analysis raised several questions about the soil depth controlling the isotopic composition of the Evaporated Water vapor, suggesting different behavior before and after the appearance of back diffusion. Experimental data also suggested a time variable value of the kinetic fractionation factor. The present paper presents the modeling of the experimental results using the coupled heat, Water and stable isotope transfer model SiSPAT_Isotope. Model results were used for investigating the above questions more in details. For this purpose, model parameters were calibrated for each soil column in order to reproduce the data. Then model results were inverted to estimate the kinetic fractionation factor. The results show that the hypothesis that the kinetic fractionation factor varies in time is plausible but the uncertainty is too large to derive firm conclusions. The largest uncertainty is found when the soil relative humidity is lower than one but Water vapor is still negligible. When back diffusion has occurred, model results are the most robust and confirm that the isotopic composition of the Evaporated Water vapor is controlled by the soil isotopic composition of the liquid Water at the peak. In this case, the retrieved kinetic fractionation factor is close to 18.9°/°°, corresponding to laminar flow.

I. Braud - One of the best experts on this subject based on the ideXlab platform.

  • isotopic composition of bare soil Evaporated Water vapor part i rubic iv experimental setup and results
    Journal of Hydrology, 2009
    Co-Authors: I. Braud, P. Biron, T. Bariac, L. Canale, Patricia Richard, Jeanpaul Gaudet, M. Vauclin
    Abstract:

    Stable Water isotopes such as oxygen 18, are natural tracers of Water movement within the soilvegetationatmosphere continuum. They provide useful information for a better understanding of evaporation and Water vapor transport within soils. This paper presents a novel controlled experimental set up. It is dedicated to detailed measurements of the evaporation fluxes from bare soil columns, as well as to the corresponding isotopic composition of the Water vapor, under non steady state conditions. The experiment allowed an accurate determination of these quantities. The formulae encountered in the literature were used to estimate the isotopic composition of the Evaporated Water vapor. None of them was able to correctly reproduce the measured isotopic composition of Water. The data were then used to estimate the value of the isotopic composition of the soil liquid Water, which should be used to get the right results for the isotopic composition of the Evaporated Water vapor. Results suggest that, when liquid transfer is dominant within the soil, the isotopic composition of evaporation was controlled by the isotopic composition of the liquid Water within very thin soil surface layers. When there is a peak in the isotopic profile, i.e. when Water vapor is dominant close to the surface, the isotopic composition of the Evaporated Water seems to be governed by the isotopic composition of the soil liquid Water at the peak. The data were also used to estimate the kinetic fractionation factor. The results suggest that the latter is not constant in time. The values seem to depend on the shape of the isotopic profile. In both cases, the uncertainty on the results is very large. The estimation of the kinetic fractionation factor is studied more in details using the modeling results presented in Part II of a companion paper where the data set is modeled using the SiSPAT_Isotope model.

  • Isotopic composition of bare soil Evaporated Water vapor. Part I: RUBIC IV experimental set up and results
    Journal of Hydrology, 2009
    Co-Authors: I. Braud, P. Biron, T. Bariac, Patrick Richard, L. Canale, J.p. Gaudet, M. Vauclin
    Abstract:

    Stable Water isotopes such as oxygen 18, are natural tracers of Water movement within the soilvegetationatmosphere continuum. They provide useful information for a better understanding of evaporation and Water vapor transport within soils. This paper presents a novel controlled experimental set up. It is dedicated to detailed measurements of the evaporation fluxes from bare soil columns, as well as to the corresponding isotopic composition of the Water vapor, under non steady state conditions. The experiment allowed an accurate determination of these quantities. The formulae encountered in the literature were used to estimate the isotopic composition of the Evaporated Water vapor. None of them was able to correctly reproduce the measured isotopic composition of Water. The data were then used to estimate the value of the isotopic composition of the soil liquid Water, which should be used to get the right results for the isotopic composition of the Evaporated Water vapor. Results suggest that, when liquid transfer is dominant within the soil, the isotopic composition of evaporation was controlled by the isotopic composition of the liquid Water within very thin soil surface layers. When there is a peak in the isotopic profile, i.e. when Water vapor is dominant close to the surface, the isotopic composition of the Evaporated Water seems to be governed by the isotopic composition of the soil liquid Water at the peak. The data were also used to estimate the kinetic fractionation factor. The results suggest that the latter is not constant in time. The values seem to depend on the shape of the isotopic profile. In both cases, the uncertainty on the results is very large. The estimation of the kinetic fractionation factor is studied more in details using the modeling results presented in Part II of a companion paper where the data set is modeled using the SiSPAT_Isotope model.

  • Isotopic composition of bare soil Evaporated Water vapor. Part II: Modeling of RUBIC IV experimental results
    Journal of Hydrology, 2009
    Co-Authors: I. Braud, P. Biron, T. Bariac, M. Vauclin
    Abstract:

    Stable Water isotopes such as oxygen 18, are tracers of Water movement within the soil vegetation atmosphere system. They provide useful information for a better understanding of evaporation and Water vapor transport within soils. In part I of this paper, we presented a novel control experimental set up under non steady conditions, dedicated to the measurement of the evaporation flux and corresponding isotopic composition from six bare soil columns. Data analysis raised several questions about the soil depth controlling the isotopic composition of the Evaporated Water vapor, suggesting different behavior before and after the appearance of back diffusion. Experimental data also suggested a time variable value of the kinetic fractionation factor. The present paper presents the modeling of the experimental results using the coupled heat, Water and stable isotope transfer model SiSPAT_Isotope. Model results were used for investigating the above questions more in details. For this purpose, model parameters were calibrated for each soil column in order to reproduce the data. Then model results were inverted to estimate the kinetic fractionation factor. The results show that the hypothesis that the kinetic fractionation factor varies in time is plausible but the uncertainty is too large to derive firm conclusions. The largest uncertainty is found when the soil relative humidity is lower than one but Water vapor is still negligible. When back diffusion has occurred, model results are the most robust and confirm that the isotopic composition of the Evaporated Water vapor is controlled by the soil isotopic composition of the liquid Water at the peak. In this case, the retrieved kinetic fractionation factor is close to 18.9°/°°, corresponding to laminar flow.

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

  • Mass and thermal balance during composting of a poultry manure—Wood shavings mixture at different aeration rates
    Process Biochemistry, 2007
    Co-Authors: Heekwon Ahn, Tom L. Richard, H.l. Choi
    Abstract:

    Abstract Composting is an exothermic process often controlled on the basis of temperature feedback, but for which the energetics of the overall system are generally not well known. In this study, the thermal balance of a poultry manure and wood shavings mixture was estimated during composting at different aeration rates. The study was conducted using 900-l vertical cylindrical reactors at high-flow (0.39–0.52 L/min kg VS) and low-flow (0.07–0.2 L/min kg VS) aeration rates. The actual amount of Evaporated Water from the high-flow reactor was 37–60% more than from the low-flow reactor in trials 1 and 2. The energy generated from degrading 1 g of VS of the poultry manure and wood shavings mixture was 16.83–19.7 kJ/g VS. The high-flow reactors showed more VS reduction, generating 22–29% more energy than low-flow reactors. The heat loss via forced convection was 52–54% of the total energy produced in the high-flow reactors, but just 17–21% in the low-flow reactors, where natural convection appeared to also play a significant role. The conductive heat loss from the low-flow reactors was greater than from the high-flow reactors, ranging from 44 to 53% in trials 1 and 2. The radiant energy loss was higher in the low-flow reactors, but in all cases was only 5% or less of the total energy loss. Because the reactor scale and configuration will affect these thermal losses, analysis of process energetics should be a fundamental part of system design.

  • mass and thermal balance during composting of a poultry manure wood shavings mixture at different aeration rates
    Process Biochemistry, 2007
    Co-Authors: Heekwon Ahn, Tom L. Richard, H.l. Choi
    Abstract:

    Abstract Composting is an exothermic process often controlled on the basis of temperature feedback, but for which the energetics of the overall system are generally not well known. In this study, the thermal balance of a poultry manure and wood shavings mixture was estimated during composting at different aeration rates. The study was conducted using 900-l vertical cylindrical reactors at high-flow (0.39–0.52 L/min kg VS) and low-flow (0.07–0.2 L/min kg VS) aeration rates. The actual amount of Evaporated Water from the high-flow reactor was 37–60% more than from the low-flow reactor in trials 1 and 2. The energy generated from degrading 1 g of VS of the poultry manure and wood shavings mixture was 16.83–19.7 kJ/g VS. The high-flow reactors showed more VS reduction, generating 22–29% more energy than low-flow reactors. The heat loss via forced convection was 52–54% of the total energy produced in the high-flow reactors, but just 17–21% in the low-flow reactors, where natural convection appeared to also play a significant role. The conductive heat loss from the low-flow reactors was greater than from the high-flow reactors, ranging from 44 to 53% in trials 1 and 2. The radiant energy loss was higher in the low-flow reactors, but in all cases was only 5% or less of the total energy loss. Because the reactor scale and configuration will affect these thermal losses, analysis of process energetics should be a fundamental part of system design.

Emil Chibowski - One of the best experts on this subject based on the ideXlab platform.

  • effects of static magnetic field on Water at kinetic condition
    Chemical Engineering and Processing, 2011
    Co-Authors: Aleksandra Szcześ, Emil Chibowski, Lucyna Holysz, P Rafalski
    Abstract:

    Water was exposed for different times to weak static magnetic field (MF) generated from a stack of magnets (B = 15 mT) or from a single permanent magnet (B = 0.27 T) at flow conditions. The Water conductivity and the amount of Evaporated Water were measured as a function of time following the application of MF. It was found that the MF decreases the Water conductivity, which is inversely proportional to the flow rate, and increases the amount of Evaporated Water, even after the Water's distillation. The effects are due to the hydrogen bond network strengthening and the perturbation of gas/liquid interface from the air nanobubbles in the Water.

  • effects of a static magnetic field on Water and electrolyte solutions
    Journal of Colloid and Interface Science, 2007
    Co-Authors: Lucyna Holysz, Aleksandra Szczes, Emil Chibowski
    Abstract:

    Water and electrolyte solutions were exposed for 5 min to a weak static magnetic field (B = 15 mT). Their conductivity and the amount of Evaporated Water were then measured as a function of time. Simultaneously, these quantities were determined for magnetically untreated samples, as reference systems. It was found that a magnetic field influences these two parameters and their changes depend on the thermodynamic functions of hydration of these ions. A roughly linear change in conductivity versus 'scaled' functions was obtained. On this basis it was concluded that the magnetic field causes changes in the hydration shells of the ions.