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Wei Sun - One of the best experts on this subject based on the ideXlab platform.
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solid liquid Equilibrium Curve of calcium in 6 mol l ammonium nitrate solution
Cement and Concrete Research, 2013Co-Authors: Keshu Wan, Wei SunAbstract:Abstract Calcium leaching of cement-based materials is of concern for scientific and application significance. Solid–liquid Equilibrium Curve of calcium is crucial for understanding the calcium leaching mechanism and for calcium leaching modeling. Solid–liquid Equilibrium Curve of Portland cement system in 6 mol/L ammonium nitrate solution is experimentally obtained using the dissolving Equilibrium between cement paste powders and simulated pore solutions. The obtained Equilibrium Curve in nitrate solution has a similar three-stage form to that in water, but the concentrations of dissolved calcium increase up to two orders of magnitude, which is the main acceleration mechanism for calcium leaching. Besides the solid–liquid Equilibrium Curve of calcium, the Equilibrium Curves between other solid elements (including sulfur, aluminum, manganese, iron) and dissolved calcium are presented. It is found that sulfur and manganese are also leached in three stages, but aluminum and iron are not leachable.
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experimental and modelling research of the accelerated calcium leaching of cement paste in ammonium nitrate solution
Construction and Building Materials, 2013Co-Authors: Keshu Wan, Wei SunAbstract:Abstract Calcium leaching of cement-based materials is of concern for scientific and application significance. Considering the altered solid–liquid Equilibrium Curve, an accelerated calcium leaching model of pure cement paste in 6 mol/L ammonium nitrate leaching solution was built up in this research. The model was numerically solved using finite difference method, and the influences of w/c ratio and initial cement composition on leaching were addressed. The accelerated model was further verified using elemental distributions and leaching fronts. Besides, through comparing the accelerated model in 6 mol/L ammonium nitrate solution and the un-accelerated model in deionized water, an accelerated factor of about 130 was found, which was slightly influenced by the initial material compositions.
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Solid–liquid Equilibrium Curve of calcium in 6 mol/L ammonium nitrate solution
Cement and Concrete Research, 2013Co-Authors: Keshu Wan, Wei SunAbstract:Abstract Calcium leaching of cement-based materials is of concern for scientific and application significance. Solid–liquid Equilibrium Curve of calcium is crucial for understanding the calcium leaching mechanism and for calcium leaching modeling. Solid–liquid Equilibrium Curve of Portland cement system in 6 mol/L ammonium nitrate solution is experimentally obtained using the dissolving Equilibrium between cement paste powders and simulated pore solutions. The obtained Equilibrium Curve in nitrate solution has a similar three-stage form to that in water, but the concentrations of dissolved calcium increase up to two orders of magnitude, which is the main acceleration mechanism for calcium leaching. Besides the solid–liquid Equilibrium Curve of calcium, the Equilibrium Curves between other solid elements (including sulfur, aluminum, manganese, iron) and dissolved calcium are presented. It is found that sulfur and manganese are also leached in three stages, but aluminum and iron are not leachable.
Kazunari Ohgaki - One of the best experts on this subject based on the ideXlab platform.
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Thermodynamic and Raman spectroscopic studies on H2+tetrahydrofuran+water and H2+ tetra-n-butyl ammonium bromide+water mixtures containing gas hydrates
Chemical Engineering Science, 2006Co-Authors: Shunsuke Hashimoto, Shu Murayama, Takeshi Sugahara, Hiroshi Sato, Kazunari OhgakiAbstract:Phase Equilibrium Curves of H2+H2+ tetrahydrofuran and H2+H2+ tetra-n-butyl ammonium bromide mixed gas hydrates were measured in a pressure range from 0.1 to 13.6 MPa. Each three-phase Equilibrium Curve converges at the maximum temperature point of pure tetrahydrofuran and tetra-n-butyl ammonium bromide hydrates, respectively. The difference of maximum temperatures is about 8 K, that is, the Equilibrium Curve of H2+H2+ tetra-n -butyl ammonium bromide mixed gas hydrate shifts to the high-temperature side from that of H2+H2+ tetrahydrofuran mixed gas hydrate. It is directly confirmed by use of Raman spectroscopy that H2H2 is enclathrated in the hydrate cages by adding a small amount of tetrahydrofuran or tetra-n -butyl ammonium bromide. In both mixed hydrates, H2H2 is enclathrated in only the small cage while tetrahydrofuran or tetra-n-butyl ammonium bromide occupies the large cages of each mixed hydrate.
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thermodynamic and raman spectroscopic studies on h2 tetrahydrofuran water and h2 tetra n butyl ammonium bromide water mixtures containing gas hydrates
Chemical Engineering Science, 2006Co-Authors: Shunsuke Hashimoto, Shu Murayama, Takeshi Sugahara, Hiroshi Sato, Kazunari OhgakiAbstract:Phase Equilibrium Curves of H2+H2+ tetrahydrofuran and H2+H2+ tetra-n-butyl ammonium bromide mixed gas hydrates were measured in a pressure range from 0.1 to 13.6 MPa. Each three-phase Equilibrium Curve converges at the maximum temperature point of pure tetrahydrofuran and tetra-n-butyl ammonium bromide hydrates, respectively. The difference of maximum temperatures is about 8 K, that is, the Equilibrium Curve of H2+H2+ tetra-n -butyl ammonium bromide mixed gas hydrate shifts to the high-temperature side from that of H2+H2+ tetrahydrofuran mixed gas hydrate. It is directly confirmed by use of Raman spectroscopy that H2H2 is enclathrated in the hydrate cages by adding a small amount of tetrahydrofuran or tetra-n -butyl ammonium bromide. In both mixed hydrates, H2H2 is enclathrated in only the small cage while tetrahydrofuran or tetra-n-butyl ammonium bromide occupies the large cages of each mixed hydrate.
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Stability Boundaries of Tetrahydrofuran + Water System
Journal of Chemical & Engineering Data, 2005Co-Authors: Takashi Makino, And Takeshi Sugahara, Kazunari OhgakiAbstract:Phase equilibria for the tetrahydrofuran + water system below atmospheric pressure were investigated in a temperature range from 272 K to 278 K. The three-phase (structure-II hydrate + aqueous solution + gas) Equilibrium Curve has a maximum temperature at 277.45 ± 0.02 K and a pressure of 4.9 ± 0.1 kPa. At this condition, the Equilibrium tetrahydrofuran composition of aqueous solution is equal to the stoichiometric ratio of tetrahydrofuran hydrate (structure-II). The tetrahydrofuran hydrate does not coexist with the gas phase beyond 277.45 K. The four-phase (structure-II hydrate + aqueous solution + ice Ih + gas) Equilibrium point exists at 272.06 ± 0.02 K and 1.1 ± 0.1 kPa, and the Equilibrium tetrahydrofuran mole fraction of aqueous solution is 0.0106 ± 0.0002.
Keshu Wan - One of the best experts on this subject based on the ideXlab platform.
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solid liquid Equilibrium Curve of calcium in 6 mol l ammonium nitrate solution
Cement and Concrete Research, 2013Co-Authors: Keshu Wan, Wei SunAbstract:Abstract Calcium leaching of cement-based materials is of concern for scientific and application significance. Solid–liquid Equilibrium Curve of calcium is crucial for understanding the calcium leaching mechanism and for calcium leaching modeling. Solid–liquid Equilibrium Curve of Portland cement system in 6 mol/L ammonium nitrate solution is experimentally obtained using the dissolving Equilibrium between cement paste powders and simulated pore solutions. The obtained Equilibrium Curve in nitrate solution has a similar three-stage form to that in water, but the concentrations of dissolved calcium increase up to two orders of magnitude, which is the main acceleration mechanism for calcium leaching. Besides the solid–liquid Equilibrium Curve of calcium, the Equilibrium Curves between other solid elements (including sulfur, aluminum, manganese, iron) and dissolved calcium are presented. It is found that sulfur and manganese are also leached in three stages, but aluminum and iron are not leachable.
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experimental and modelling research of the accelerated calcium leaching of cement paste in ammonium nitrate solution
Construction and Building Materials, 2013Co-Authors: Keshu Wan, Wei SunAbstract:Abstract Calcium leaching of cement-based materials is of concern for scientific and application significance. Considering the altered solid–liquid Equilibrium Curve, an accelerated calcium leaching model of pure cement paste in 6 mol/L ammonium nitrate leaching solution was built up in this research. The model was numerically solved using finite difference method, and the influences of w/c ratio and initial cement composition on leaching were addressed. The accelerated model was further verified using elemental distributions and leaching fronts. Besides, through comparing the accelerated model in 6 mol/L ammonium nitrate solution and the un-accelerated model in deionized water, an accelerated factor of about 130 was found, which was slightly influenced by the initial material compositions.
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Solid–liquid Equilibrium Curve of calcium in 6 mol/L ammonium nitrate solution
Cement and Concrete Research, 2013Co-Authors: Keshu Wan, Wei SunAbstract:Abstract Calcium leaching of cement-based materials is of concern for scientific and application significance. Solid–liquid Equilibrium Curve of calcium is crucial for understanding the calcium leaching mechanism and for calcium leaching modeling. Solid–liquid Equilibrium Curve of Portland cement system in 6 mol/L ammonium nitrate solution is experimentally obtained using the dissolving Equilibrium between cement paste powders and simulated pore solutions. The obtained Equilibrium Curve in nitrate solution has a similar three-stage form to that in water, but the concentrations of dissolved calcium increase up to two orders of magnitude, which is the main acceleration mechanism for calcium leaching. Besides the solid–liquid Equilibrium Curve of calcium, the Equilibrium Curves between other solid elements (including sulfur, aluminum, manganese, iron) and dissolved calcium are presented. It is found that sulfur and manganese are also leached in three stages, but aluminum and iron are not leachable.
Ivo B Rietveld - One of the best experts on this subject based on the ideXlab platform.
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experimental and topological determination of the pressure temperature phase diagram of morniflumate a pharmaceutical ingredient with anti inflammatory properties
The Journal of Chemical Thermodynamics, 2017Co-Authors: Maria Barrio, Ll J Tamarit, R Ceolin, Benoit Robert, Christophe Guechot, Jeanmarie Teulon, Ivo B RietveldAbstract:Abstract The pressure-temperature phase diagram of morniflumate (niflumic acid β-morpholinoethyl ester) has been obtained by high-pressure thermal analysis. In addition, calorimetric melting data (TI→L = (348.1 ± 0.4) K and ΔHI→L = (89 ± 2) J·g−1) and the specific volumes of the solid and the liquid state have been obtained under normal pressure. Comparison of the measured high-pressure melting data with the Equilibrium Curve obtained through the Clapeyron equation indicates that the initial slopes are the same (dP/dT = (2.96 ± 0.06) MPa·K−1) at the melting point under normal pressure. The fact that the Clapeyron equation can be used to construct topological phase diagrams may be of interest for the food and pharmaceutical industries.
Shunsuke Hashimoto - One of the best experts on this subject based on the ideXlab platform.
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thermodynamic and raman spectroscopic studies on h2 tetrahydrofuran water and h2 tetra n butyl ammonium bromide water mixtures containing gas hydrates
Chemical Engineering Science, 2006Co-Authors: Shunsuke Hashimoto, Shu Murayama, Takeshi Sugahara, Hiroshi Sato, Kazunari OhgakiAbstract:Phase Equilibrium Curves of H2+H2+ tetrahydrofuran and H2+H2+ tetra-n-butyl ammonium bromide mixed gas hydrates were measured in a pressure range from 0.1 to 13.6 MPa. Each three-phase Equilibrium Curve converges at the maximum temperature point of pure tetrahydrofuran and tetra-n-butyl ammonium bromide hydrates, respectively. The difference of maximum temperatures is about 8 K, that is, the Equilibrium Curve of H2+H2+ tetra-n -butyl ammonium bromide mixed gas hydrate shifts to the high-temperature side from that of H2+H2+ tetrahydrofuran mixed gas hydrate. It is directly confirmed by use of Raman spectroscopy that H2H2 is enclathrated in the hydrate cages by adding a small amount of tetrahydrofuran or tetra-n -butyl ammonium bromide. In both mixed hydrates, H2H2 is enclathrated in only the small cage while tetrahydrofuran or tetra-n-butyl ammonium bromide occupies the large cages of each mixed hydrate.
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Thermodynamic and Raman spectroscopic studies on H2+tetrahydrofuran+water and H2+ tetra-n-butyl ammonium bromide+water mixtures containing gas hydrates
Chemical Engineering Science, 2006Co-Authors: Shunsuke Hashimoto, Shu Murayama, Takeshi Sugahara, Hiroshi Sato, Kazunari OhgakiAbstract:Phase Equilibrium Curves of H2+H2+ tetrahydrofuran and H2+H2+ tetra-n-butyl ammonium bromide mixed gas hydrates were measured in a pressure range from 0.1 to 13.6 MPa. Each three-phase Equilibrium Curve converges at the maximum temperature point of pure tetrahydrofuran and tetra-n-butyl ammonium bromide hydrates, respectively. The difference of maximum temperatures is about 8 K, that is, the Equilibrium Curve of H2+H2+ tetra-n -butyl ammonium bromide mixed gas hydrate shifts to the high-temperature side from that of H2+H2+ tetrahydrofuran mixed gas hydrate. It is directly confirmed by use of Raman spectroscopy that H2H2 is enclathrated in the hydrate cages by adding a small amount of tetrahydrofuran or tetra-n -butyl ammonium bromide. In both mixed hydrates, H2H2 is enclathrated in only the small cage while tetrahydrofuran or tetra-n-butyl ammonium bromide occupies the large cages of each mixed hydrate.