• Korean Chemical Engineering Research
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• v.43 no.4
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• pp.467-473
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• 2005

Liquid phase nitrous oxide ($N_2O$) contains air, carbon monoxide, water, carbon dioxide and NOx as main impurities. It is known to be very dangerous to obtain a very pure $N_2O$ product by using solidification at low temperature. In this study a new method to obtain a high purity of $N_2O$ product based on a continuous distillation process was introduced. For the modeling of the continuous distillation process to obtain a product having a purity over 99.999％ of $N_2O$ stream, Intalox wire gauze packing- No. SCH-80S gauze packing column was used. Peng-Robinson equation of state was used for the modeling of the continuous distillation process and refrigeration system. Computational results performed in this work showed a good agreement with Aspen Plus simulation results.

• Korean Chemical Engineering Research
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• v.52 no.3
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• pp.307-313
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• 2014

In this study, an optimization process design has been performed to separate 99.9 mol% of Isobutyl Acetate from binary azeotropic mixture of Isobutyl Acetate and Isobutyl Alcohol system using a Pressure Swing Distillation (PSD). PSD is used to separate binary azeotropic mixtures using the difference between the relative volatilities and azeotropic compositions by changing the system pressure. Non-Random Two Liquid (NRTL) model for liquid phase and the Peng-Robinson equation for vapor phase are used. An optimization study for the reflux ratio and feed stage locations which minimize the total reboiler heat duties are studied. Since PSD process consists of two columns, i.e. high pressure and low pressure, the effect of column sequence on the optimum conditions is reported.

• Clean Technology
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• v.11 no.3
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• pp.147-152
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• 2005

For estblishing the best technique for the micronization of Ibuprofen using supercritical fluids, the solubility should be known. The solubility of Ibuprofen in supercritical carbon dioxide was measured by observing the cloud point. The cloud point was observed using high pressure equipment equipped a variable volume view cell between temperature of 35, 40 and $45^{\circ}C$. The solubility data was correlated by the Peng-Robinson equation of state Solute physical properties, such as critical temperature (Tc), critical pressure (Pc) and acentric factor (${\omega}$) were estimated by the some group contribution method. As pressure was increased, the solubility increased at constant temperature. The retrograde phenomenon by a solute vapor pressure and a density of solvent was observed at the pressure of around 150bar. It was found that $CO_2$ can be used as a supercritical solvent in micronization of ibuprofen by RESS.

• Korean Chemical Engineering Research
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• v.48 no.6
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• pp.763-767
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• 2010

High-pressure phase behavior for the binary mixture of 1-propanol with supercritical $CO_2$ has been measured by means of a high-pressure phase equilibrium apparatus equipped with a variable-volume view cell. The equilibrium loci of the pressure - composition and pressure - temperature were obtained for the binary mixture of 1-propanol + $CO_2$ system at 305.15 K, 313.15 K, 323.15 K and 333.15 K, and from 2 MPa to 11 MPa. The critical temperature of the mixture increased with the temperature. The pressure-composition line for the binary mixture of $CO_2$-1-propanol system showed a typical type-II phase behavior. The experimental P-x envelopes were correlated by using the Peng-Robinson equation of state in a satisfactory manner to obtain the parameters with $k_{ij}=0.116$ and ${\eta}_{ij}=-0.065$.

• Bulletin of the Korean Mathematical Society
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• v.42 no.3
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• pp.555-561
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• 2005

In this note we give characterizations for certain HNN extensions with central associated subgroups to be residually finite. We then apply our results to HNN extensions of polycyclic-by-finite groups.

• Proceedings of the Korean Magnestics Society Conference
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• 2007.05a
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• pp.309.2-309.2
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• 2007

• Proceedings of the Korean Magnestics Society Conference
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• 2007.05a
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• pp.222.1-222.1
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• 2007

• Proceedings of the Korean Magnestics Society Conference
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• 2007.05a
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• pp.221.1-221.1
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• 2007

• Bulletin of the Korean Chemical Society
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• v.34 no.9
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• pp.2800-2802
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• 2013

• Proceedings of the Zoological Society Korea Conference
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• 1998.10b
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• pp.122.2-122
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• 1998

No Abstract, See Full Text