The Experts below are selected from a list of 189 Experts worldwide ranked by ideXlab platform
Chang Ha Lee - One of the best experts on this subject based on the ideXlab platform.
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Air separation by a small-scale two-bed medical O2 pressure swing adsorption
Industrial & Engineering Chemistry Research, 2001Co-Authors: Jeong-geun Jee, Jong-seok Lee, Chang Ha LeeAbstract:A small-scale two-bed six-step pressure swing adsorption (PSA) process using zeolite 13X was performed to provide oxygen-enriched air in the medical system. The binary mixture N2/O2 (79/21 vol %) was used for PSA experiments. Cyclic behaviors of the PSA process were investigated from unsteady- to steady-state Conditions. Also, effects of various operating parameters on the PSA performance such as the P/F ratio, adsorption pressure, feed flow rate, and adsorption step time were investigated experimentally under the Nonisothermal Condition. The effect of the P/F ratio was noticeably changed according to the adsorption pressure and feed flow rate Conditions. The higher the adsorption pressure, the slower the increasing rate of purity and the higher the decreasing rate of recovery. However, as the adsorption pressure became higher, the effect of the P/F ratio on the O2 purity became smaller. Furthermore, the effect of adsorption pressure on the O2 purity and recovery was diminished gradually to the increase o...
Qiang Zheng - One of the best experts on this subject based on the ideXlab platform.
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A query on crystallization temperature‐dependent cooling function under Nonisothermal Condition
Journal of Polymer Science Part B: Polymer Physics, 2006Co-Authors: Yonggang Shangguan, Yihu Song, Qiang ZhengAbstract:The cooling function (κ) in Ozawa model was investigated through theoretic analysis and experimental method. Different from the fact accepted by researchers over past decades that κ(T) depends only on the crystallization temperature (T) and consequently the parameters for Nonisothermal crystallization kinetics could be obtained by plotting ln[− ln(1 − X(T))] versus ln λ at a given T, we found that κ at a given T was also dependent on onset temperature (T0) of crystallization process. Because T0 varies with cooling rate (λ) in Nonisothermal crystallization, we conclude that κ is a binary function of T and λ, which was validated by our kinetic data from differential scanning calorimetry measurement in a wide λ range from 1 to 80 °C/min. It is suggested that the conventional method for calculating kinetic parameters based on Ozawa model, by plotting ln[− ln(1 − X(T))] versus ln λ, might not be exact for Nonisothermal crystallization. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44:795–800, 2006
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a query on crystallization temperature dependent cooling function under Nonisothermal Condition
Journal of Polymer Science Part B, 2006Co-Authors: Yonggang Shangguan, Yihu Song, Qiang ZhengAbstract:The cooling function (κ) in Ozawa model was investigated through theoretic analysis and experimental method. Different from the fact accepted by researchers over past decades that κ(T) depends only on the crystallization temperature (T) and consequently the parameters for Nonisothermal crystallization kinetics could be obtained by plotting ln[− ln(1 − X(T))] versus ln λ at a given T, we found that κ at a given T was also dependent on onset temperature (T0) of crystallization process. Because T0 varies with cooling rate (λ) in Nonisothermal crystallization, we conclude that κ is a binary function of T and λ, which was validated by our kinetic data from differential scanning calorimetry measurement in a wide λ range from 1 to 80 °C/min. It is suggested that the conventional method for calculating kinetic parameters based on Ozawa model, by plotting ln[− ln(1 − X(T))] versus ln λ, might not be exact for Nonisothermal crystallization. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44:795–800, 2006
Jeong-geun Jee - One of the best experts on this subject based on the ideXlab platform.
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Air separation by a small-scale two-bed medical O2 pressure swing adsorption
Industrial & Engineering Chemistry Research, 2001Co-Authors: Jeong-geun Jee, Jong-seok Lee, Chang Ha LeeAbstract:A small-scale two-bed six-step pressure swing adsorption (PSA) process using zeolite 13X was performed to provide oxygen-enriched air in the medical system. The binary mixture N2/O2 (79/21 vol %) was used for PSA experiments. Cyclic behaviors of the PSA process were investigated from unsteady- to steady-state Conditions. Also, effects of various operating parameters on the PSA performance such as the P/F ratio, adsorption pressure, feed flow rate, and adsorption step time were investigated experimentally under the Nonisothermal Condition. The effect of the P/F ratio was noticeably changed according to the adsorption pressure and feed flow rate Conditions. The higher the adsorption pressure, the slower the increasing rate of purity and the higher the decreasing rate of recovery. However, as the adsorption pressure became higher, the effect of the P/F ratio on the O2 purity became smaller. Furthermore, the effect of adsorption pressure on the O2 purity and recovery was diminished gradually to the increase o...
Yonggang Shangguan - One of the best experts on this subject based on the ideXlab platform.
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A query on crystallization temperature‐dependent cooling function under Nonisothermal Condition
Journal of Polymer Science Part B: Polymer Physics, 2006Co-Authors: Yonggang Shangguan, Yihu Song, Qiang ZhengAbstract:The cooling function (κ) in Ozawa model was investigated through theoretic analysis and experimental method. Different from the fact accepted by researchers over past decades that κ(T) depends only on the crystallization temperature (T) and consequently the parameters for Nonisothermal crystallization kinetics could be obtained by plotting ln[− ln(1 − X(T))] versus ln λ at a given T, we found that κ at a given T was also dependent on onset temperature (T0) of crystallization process. Because T0 varies with cooling rate (λ) in Nonisothermal crystallization, we conclude that κ is a binary function of T and λ, which was validated by our kinetic data from differential scanning calorimetry measurement in a wide λ range from 1 to 80 °C/min. It is suggested that the conventional method for calculating kinetic parameters based on Ozawa model, by plotting ln[− ln(1 − X(T))] versus ln λ, might not be exact for Nonisothermal crystallization. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44:795–800, 2006
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a query on crystallization temperature dependent cooling function under Nonisothermal Condition
Journal of Polymer Science Part B, 2006Co-Authors: Yonggang Shangguan, Yihu Song, Qiang ZhengAbstract:The cooling function (κ) in Ozawa model was investigated through theoretic analysis and experimental method. Different from the fact accepted by researchers over past decades that κ(T) depends only on the crystallization temperature (T) and consequently the parameters for Nonisothermal crystallization kinetics could be obtained by plotting ln[− ln(1 − X(T))] versus ln λ at a given T, we found that κ at a given T was also dependent on onset temperature (T0) of crystallization process. Because T0 varies with cooling rate (λ) in Nonisothermal crystallization, we conclude that κ is a binary function of T and λ, which was validated by our kinetic data from differential scanning calorimetry measurement in a wide λ range from 1 to 80 °C/min. It is suggested that the conventional method for calculating kinetic parameters based on Ozawa model, by plotting ln[− ln(1 − X(T))] versus ln λ, might not be exact for Nonisothermal crystallization. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44:795–800, 2006
Masayuki Yamaguchi - One of the best experts on this subject based on the ideXlab platform.
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Modifying the rheological properties of polypropylene under elongational flow by adding polyethylene
Journal of Rheology, 2019Co-Authors: Yoko Fujii, Riho Nishikawa, Panitha Phulkerd, Masayuki YamaguchiAbstract:Adding polyethylene greatly affects the rheological response of isotactic polypropylene (PP) under uniaxial elongational flow. Though strain hardening in the transient elongational viscosity barely appeared in pure PP, we induced strain hardening by adding low-density polyethylene (LDPE) to PP, even though the blends showed a phase-separated structure. During elongational flow, LDPE droplets dispersed in the PP were deformed in the flow direction. Because LDPE shows marked strain hardening in the elongational viscosity, the deformed LDPE droplets behaved as rigid fibers as the strain increased. Consequently, the PP between the fibrous LDPE droplets experienced excess localized deformation, which increased the apparent elongational viscosity. Furthermore, adding the high-density polyethylene (HDPE) increased the drawdown force—defined as the force required for uniaxial stretching of a molten polymer in the Nonisothermal Condition. This behavior comes from the rapid crystallization of HDPE, which causes the deformed HDPE particles to act as rigid fibers in the molten PP and enhances the PP crystallization, which increases the elongational stress.Adding polyethylene greatly affects the rheological response of isotactic polypropylene (PP) under uniaxial elongational flow. Though strain hardening in the transient elongational viscosity barely appeared in pure PP, we induced strain hardening by adding low-density polyethylene (LDPE) to PP, even though the blends showed a phase-separated structure. During elongational flow, LDPE droplets dispersed in the PP were deformed in the flow direction. Because LDPE shows marked strain hardening in the elongational viscosity, the deformed LDPE droplets behaved as rigid fibers as the strain increased. Consequently, the PP between the fibrous LDPE droplets experienced excess localized deformation, which increased the apparent elongational viscosity. Furthermore, adding the high-density polyethylene (HDPE) increased the drawdown force—defined as the force required for uniaxial stretching of a molten polymer in the Nonisothermal Condition. This behavior comes from the rapid crystallization of HDPE, which causes the...
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Rheological response under Nonisothermal stretching for immiscible blends of isotactic polypropylene and acrylate polymer
Journal of Rheology, 2017Co-Authors: Jiraporn Seemork, Takumi Sako, Mohd Amran Ali, Masayuki YamaguchiAbstract:The addition of acrylate polymers with low molecular weight, such as poly(isobutyl methacrylate) (PIBM) and poly(methyl methacrylate) (PMMA), effectively enhances the force required to stretch a molten polypropylene (PP) at the Nonisothermal Condition without the enhancement of shear viscosity in the molten state. The mechanism of this phenomenon is found to be attributed to prompt solidification of PIBM and PMMA droplets, which deform greatly to the flow direction in the die land and near the die exit during the extrusion and stretching processes. After the die exit, the deformed droplets show the glassification prior to the crystallization of PP matrix because of the rapid cooling at stretching. Consequently, they behave like rigid fibers in a molten PP, which provide the excess stress by large shear deformation of the matrix between the dispersed glassy fibers during stretching.
