The Experts below are selected from a list of 1335 Experts worldwide ranked by ideXlab platform
Boda Liu - One of the best experts on this subject based on the ideXlab platform.
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stretching chemical heterogeneities by melt migration in an upwelling mantle an analysis based on time dependent batch and Fractional melting models
Earth and Planetary Science Letters, 2018Co-Authors: Yan Liang, Boda LiuAbstract:Abstract The source region of basalt in the upper mantle is heterogeneous and may consist of depleted background mantle and blobs of enriched mantle. The size, shape, and distribution of the enriched blobs in the upper mantle are unknown but may play an important role in controlling variations in isotope ratios and trace element abundances in basalts and residual peridotites. During decompression melting, the mass flux of interstitial melt increases while the mass flux of residual solid decreases upward from the solidus, resulting in an acceleration of the effective transport velocity for an incompatible trace element in the residue. Consequently, a blob of chemical heterogeneity is stretched during its transit through the melting column. Here we quantify the melt migration induced size change by allowing trace element abundances and isotope ratios in the mantle source to vary as a function of time and space. We use simple analytical solutions for the time-dependent batch melting and Fractional melting models to illustrate how a trace element or an isotope ratio varies spatially and temporally in an upwelling and chemically heterogeneous melting column. We show that an enriched blob as marked by isotope or incompatible trace element anomaly is variably stretched along the direction of melt flow during its transit through the melting column. The amount of stretching depends on the extent of melting, style of melt extraction (batch vs. Fractional), Porosity of the melting column, and partition coefficient, and can be quantified by a dimensionless parameter called the stretching factor. For radiogenic isotopes U, Th, Pb, Sr, Nd, and Hf, a factor of 2 ∼ 8 stretching is expected for the residue and a factor of at least 30 is found for the channel melt. For near Fractional melting beneath mid-ocean ridge, an enriched Nd isotope signal takes approximately 10 times more time to transit through the low-Porosity matrix than through the high-Porosity channel. Hence chemical heterogeneities observed in residual peridotites and extracted melts are decoupled both spatially and temporally, which has important implications for the interpretation of isotope and trace element characteristics of the basalts and residual peridotites.
Yan Liang - One of the best experts on this subject based on the ideXlab platform.
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stretching chemical heterogeneities by melt migration in an upwelling mantle an analysis based on time dependent batch and Fractional melting models
Earth and Planetary Science Letters, 2018Co-Authors: Yan Liang, Boda LiuAbstract:Abstract The source region of basalt in the upper mantle is heterogeneous and may consist of depleted background mantle and blobs of enriched mantle. The size, shape, and distribution of the enriched blobs in the upper mantle are unknown but may play an important role in controlling variations in isotope ratios and trace element abundances in basalts and residual peridotites. During decompression melting, the mass flux of interstitial melt increases while the mass flux of residual solid decreases upward from the solidus, resulting in an acceleration of the effective transport velocity for an incompatible trace element in the residue. Consequently, a blob of chemical heterogeneity is stretched during its transit through the melting column. Here we quantify the melt migration induced size change by allowing trace element abundances and isotope ratios in the mantle source to vary as a function of time and space. We use simple analytical solutions for the time-dependent batch melting and Fractional melting models to illustrate how a trace element or an isotope ratio varies spatially and temporally in an upwelling and chemically heterogeneous melting column. We show that an enriched blob as marked by isotope or incompatible trace element anomaly is variably stretched along the direction of melt flow during its transit through the melting column. The amount of stretching depends on the extent of melting, style of melt extraction (batch vs. Fractional), Porosity of the melting column, and partition coefficient, and can be quantified by a dimensionless parameter called the stretching factor. For radiogenic isotopes U, Th, Pb, Sr, Nd, and Hf, a factor of 2 ∼ 8 stretching is expected for the residue and a factor of at least 30 is found for the channel melt. For near Fractional melting beneath mid-ocean ridge, an enriched Nd isotope signal takes approximately 10 times more time to transit through the low-Porosity matrix than through the high-Porosity channel. Hence chemical heterogeneities observed in residual peridotites and extracted melts are decoupled both spatially and temporally, which has important implications for the interpretation of isotope and trace element characteristics of the basalts and residual peridotites.
Vadila Giovana Guerra - One of the best experts on this subject based on the ideXlab platform.
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studies on permeability properties and particle capture efficiencies of porous sic ceramics processed by oxide bonding technique
Journal of Porous Media, 2015Co-Authors: Atanu Dey, Nijhuma Kayal, Omprakash Chakrabarti, Rafael Falchi Caldato, Caio M Andre, M D M Innocentini, Vadila Giovana GuerraAbstract:Porous SiC ceramics bonded with mullite MBS of Fractional Porosity (epsilon) of 0.29-0.56, average pore size (d(pore)) of 5-11 mu m, flexural strength (sigma) of 9-34 MPa, and elastic modulus (E) of 7-28 GPa] and cordierite (CBS with epsilon of 0.33-0.72, d(pore) of 6-50 mu m, sigma of 5-54 MPa, and E of 6-42 GPa) were prepared by heating in air at 1350-1500 degrees C compacts of desired amounts of SiC, Al2O3, and MgO powders and petroleum coke dust as the pore former. Air permeation behavior of well-characterized samples was studied with fluid superficial velocity (v(s)) from 0.08 to 1.0 m s(-1) and at RT to 750 degrees C. The Darcian (k(1)) and non-Darcian (k(2)) permeability coefficients were evaluated by fitting the Forchheimer's equation to experimental pressure drop-superficial velocity data. Porosity dependence of permeability coefficients was explained in terms of structural characteristics. Changes in pressure drop experienced by the porous ceramics at high temperatures were explained by temperature dependence of permeability coefficients and variation of fluid properties. Collection efficiency (E-overall) of filter ceramics operating on removal of solid NaCl nanoaerosol particles (of 7-300 nm size) was determined from particle counts before and after filtration at v(s) = 0.05-0.10 m s(-1). Experimental results showed variation of E-overall from 96.7 to 99.9% for change of epsilon from 0.56 to 0.68. The size-selective Fractional collection efficiency at different Porosity levels was derived using the well-known single-collector efficiency model considering some boundary conditions and the model data were validated with experimental results. The test results were used to examine the applicability of the filter ceramics in nanoparticle aerosol filtration processes.
Guerra Vadila - One of the best experts on this subject based on the ideXlab platform.
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Studies on permeability properties and particle capture efficiencies of porous SiC ceramics processed by oxide bonding technique
ECI Digital Archives, 2014Co-Authors: Dey Atanu, Kayal Nijhuma, Chakrabarti Omprakash, Caldato Rafael, Andre Caio, Innocentini Murilo, Guerra VadilaAbstract:Porous SiC ceramics bonded with mullite (MBS of Fractional Porosity (e) of 0.29-0.56, average pore size (dpore) of 5-11 μm, flexural strength (σ) of 9-34 MPa and elastic modulus (E) of 7-28GPa) and cordierite (CBS with e of 0.33-0.72, dpore of 6-50 μm, σ of 5-54 MPa and E of 6-42 GPa) were prepared by heating in air at 1350-1500°C compacts of desired amounts of SiC, Al2O3 and MgO powders and petroleum coke dust as the pore former. Air permeation behavior of well-characterized samples was studied with fluid superficial velocity (vs) from 0.08 to 1.0 m s-1and at RT to 750°C. The Darcian (k1) and non-Darcian (k2) permeability coefficients were evaluated by fitting the Forchheimer’s equation to experimental pressure drop-superficial velocity data. Porosity dependence of permeability coefficients was explained in terms of structural characteristics. Changes in pressure drop experienced by the porous ceramics at high temperatures were explained by temperature dependence of permeability coefficients and variation of fluid properties. Collection efficiency (η) of filter ceramics operating on removal of solid NaCl nanoaerosol particles (of 7-300 nm size) was determined from particle counts before and after filtration at vs = 0.05-0.10 m s-1. Experimental results showed variation of η from 96.7 to 99.9% for change of e from 0.56 to 0.68. The size-selective Fractional collection efficiency at different Porosity levels was derived using the well-known single-collector efficiency model considering some boundary conditions and the model data were validated with experimental results. The test results were used to examine the applicability of the filter ceramics in nanoparticle filtration processes
Atanu Dey - One of the best experts on this subject based on the ideXlab platform.
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studies on permeability properties and particle capture efficiencies of porous sic ceramics processed by oxide bonding technique
Journal of Porous Media, 2015Co-Authors: Atanu Dey, Nijhuma Kayal, Omprakash Chakrabarti, Rafael Falchi Caldato, Caio M Andre, M D M Innocentini, Vadila Giovana GuerraAbstract:Porous SiC ceramics bonded with mullite MBS of Fractional Porosity (epsilon) of 0.29-0.56, average pore size (d(pore)) of 5-11 mu m, flexural strength (sigma) of 9-34 MPa, and elastic modulus (E) of 7-28 GPa] and cordierite (CBS with epsilon of 0.33-0.72, d(pore) of 6-50 mu m, sigma of 5-54 MPa, and E of 6-42 GPa) were prepared by heating in air at 1350-1500 degrees C compacts of desired amounts of SiC, Al2O3, and MgO powders and petroleum coke dust as the pore former. Air permeation behavior of well-characterized samples was studied with fluid superficial velocity (v(s)) from 0.08 to 1.0 m s(-1) and at RT to 750 degrees C. The Darcian (k(1)) and non-Darcian (k(2)) permeability coefficients were evaluated by fitting the Forchheimer's equation to experimental pressure drop-superficial velocity data. Porosity dependence of permeability coefficients was explained in terms of structural characteristics. Changes in pressure drop experienced by the porous ceramics at high temperatures were explained by temperature dependence of permeability coefficients and variation of fluid properties. Collection efficiency (E-overall) of filter ceramics operating on removal of solid NaCl nanoaerosol particles (of 7-300 nm size) was determined from particle counts before and after filtration at v(s) = 0.05-0.10 m s(-1). Experimental results showed variation of E-overall from 96.7 to 99.9% for change of epsilon from 0.56 to 0.68. The size-selective Fractional collection efficiency at different Porosity levels was derived using the well-known single-collector efficiency model considering some boundary conditions and the model data were validated with experimental results. The test results were used to examine the applicability of the filter ceramics in nanoparticle aerosol filtration processes.
