불활성 기체 혼합물의 물성에 관한 열역학적 실험식

김재덕,여미순,이윤우,노경호 한국화재소방학회 2003 한국화재소방학회논문지 Vol.17 No.2

대체 소화제로 사용되는 불활성 기체 중 Ar, N₂, CO₂에 대한 혼합물에서의 물성(포화압력, 밀도, 점도)에 관한 실험식을 구하였다. Mixing rule에 의해 계산한 값을 이용하여 다항식 등의 회귀분석에 의해서 실험식을 얻었다. 포화압력은 온도에 대하여 1차 실험식으로 표시하였다. 압축인자와 포화압력을 이용하여 온도에 대한 밀도에 관한 실험식을 제시하였다. 점도는 온도에 대한 지수함수로 표시하였다. Ar, N₂, CO₂ 혼합물의 조성이 40/50/10(mol. %)에서 열역학적 실험식을 구하였다. For the inert gases of Ar, N² and CO², the empirical equations of the gas mixture were correlated in terms of saturated pressure, density and viscosity. They were obtained by regression analysis based on the mixing rule. The empirical equation of saturated pressure was assumed as the first order function of temperature. The empirical form of density was expressed as compressibility factor and saturated pressure while the empirical equation of viscosity was formulated as a power function of temperature. This empirical equations of the physical properties were obtained in the composition of Ar, N² and CO², 40/50/10 (mol. %).

불활성 기체에 대한 열역학적 실험식

김재덕,여미순,이윤우,노경호 한국화재소방학회 2003 한국화재소방학회논문지 Vol.17 No.1

Halon 대체 소화제로 쓰이는 불활성 기체 중 Ar, N₂, CO₂의 단일 성분일 때의 물성(포화압력, 밀도, 점도)에 관한 실험식을 구하였다. 문헌에서 얻은 실험값을 이용하여 다항식 등의 회귀분석에 의해서 실험식을 얻었다. 포화압력은 온도에 대하여 각각 2차와 3차의 실험식으로 표시하였다. 밀도는 Ar, N₂는 온도에 대한 1차 함수로 표시하였고, CO₂는 온도에 대하여 각각 2차와 3차의 실험식으로 표시하였다. 점도는 온도에 대한 지수함수로 표시하였다. 이들 실험식을 이용하여 단일 성분일 때의 상태를 알 수 있다. Inert gases, Ar, N₂, CO₂, as a Halon alternative, the empirical equations were correlated in terms of saturated pressure, density and viscosity. They were obtained by regression analysis from the experimental data in the literature. The empirical equations of saturated pressure were expressed as the second and third order function of temperature. The empirical equation for Ar and N₂ of density were expressed as the first order function of temperature. And CO₂ was expressed as the second and third order function of temperature. The empirical equation of viscosity was formulated as a power function with temperature. This empirical equations would allow us to predict pure component state.

대체 소화제의 열역학적 물성 비교

김재덕,여미순,이광진,이윤우,장윤호,노경호 한국화재소방학회 2004 한국화재소방학회논문지 Vol.18 No.1

몬트리올 의정서에 의해서 규제받는 CFCs와 Halon의 대체 물질인 HFC-23, HFC-125, HFC-227ea, HFC-236fa와 불활성 화합물 Ar, N₂, CO₂의 열역학적 물성인 포화압력, 밀도, 엔탈피, 점도를 비교하였다. 본 연구에서는 소화제의 물성을 문헌값을 온도의 함수로서 표시하였다. HFC화합물의 열역학적 물성은 Halon-1301과 비슷하게 나타내었다. 불활성 화합물은 주로 혼합물로 이용되지만, 불활성 화합물의 물성은 Halon-13O1에 비하며 바람직하지 않았다. For CFCs and Halons regulated by Montreal Protocol and their alternatives of HFC-23, HFC-125, HFC-227ea, HFC-236fa and the mixtures of inert gases of Ar, N₂ and CO₂, the thermodynamic properties of saturated pressure, density, enthalpy and viscosity were compared. In this study, the data from literature were expressed as a function of temperature. Thermodynamic properties of HFC compounds were similar to those of Halon-1301. Inert gas was mainly used as a mixture, but the physical properties of the inert gas does not have the favorable advantages over those of Halon-1301.

Optimal Mobile - Phase Composition for the Resolution of Deoxyribonucleosides in RP - HPLC

Row, Kyung Ho,Choi, Dai Ki,So, Myoung Seup,Park, Young Kwang 한국공업화학회 1998 Journal of Industrial and Engineering Chemistry Vol.4 No.1

Five deoxyribonucleosides (dCyd, dUrd, dGuo, dThd, and dAdo) were separated by RP-HPLC under isocratic conditions. The volume percent of organic modifier was changed from 3.0 to 10.0 for methanol and acetonitrile, respectively. Potassium phosphate, sodium borate and TADP were used as buffer chemicals. The experimental results showed that for the separation of deoxyribonucleosides methanol was superior to acetonitrile as the organic modifier and the optimum condition of mobile phase was 5.0 vol. % of acetonitrile with 20 mM . sodium borate.

COMPUTATIONAL ALGORITHM TO PREDICT PEAK PROFILES IN PREPARATIVE HIGH - PERFORMANCE CHROMATOGRAPHY

Row, Kyung Ho,Larin, Alexander V 한국화학공학회 1995 Korean Journal of Chemical Engineering Vol.12 No.5

The computational algorithm and the Prep-LEAR program have been performed on the basis of the LEA model of chromatography. This program intends for calculation of peak profiles in non-linear high-performance chromatography and uses unsimplified adsorption isotherm equations. The computational algorithm and program have been tested by applying these to experimental data of thymine adsorption under conditions of reversed-phase high-performance liquid chromatography. The results of numerical calculations for different sample size introduced agree satisfactorily with experimental data and show the characteristic properties of high-performance chromatography. The usefulness of the Prep-LEAK program was confirmed by predicting peak profiles in preparative adsorption chromatographic processes.

Separation Technology , Thermodynamics : Separation of Phospholipids from Soybean by NP - HPLC with ELSD

(Kyung Ho Row),(Duk Hui Kang),(Sueng Ki Lee) 한국화학공학회 2002 Korean Journal of Chemical Engineering Vol.19 No.5

Linear Correlation Equation for Retention Factor of Nucleic Acid Using QSPR

Kyung Ho Row,Soon Koo Han,Jinzhu Zheng 대한화학회 2005 Bulletin of the Korean Chemical Society Vol.26 No.4

In the reversed-phase chromatography, the retention time of sample was investigated based on the molecular structure of compound. Several descriptors that were related to retention factors were selected, and then the values of descriptors were calculated with several softwares. The effect of retention factor was measured with calculated values, and the results were obtained that each descriptors of molecular structure of compound have different effect on the retention factor. Therefore, the empirical equation for seven types of descriptors considered was obtained, and it has high values of correlation coefficient. Furthermore, the experimental data and calculated values have good agreement.

PREPARATIVE SEPARATION OF PHOSPHOLIPIDS FROM SOYBEAN BY NP-HPLC

Row, Kyung Ho,Lee, Ju Weon 한국화학공학회 1997 Korean Journal of Chemical Engineering Vol.14 No.5

Soybean phospholipids-phosphatidylethanolamine (PE). phosphatidylinositol (PI), and phosphatidylcholine (PC)-were separated by normal-phase high performance liquid chromatography. The system was operated in a gradient mode. The experimental variables were gradient time and mobile phase composition. The experimental results showed that PE, PI and PC were resolved by three step-change gradient modes which employed ternary systems of hexane/1-propanol/water (58/40/2 and 56/40/4 by vol.%) and methanol/1-propanol/water (80/18/2, by vol.%) for the gradient times of 10, 30 and 76 min, respectively.

Simulation of the Combined Continuous and Preparative Separation of Three Close - Boiling Components in a Gas - Liquid Chromatography

Row, Kyung Ho,Choi, Dae Ki,Lee, Youn Yong 한국화학공학회 1991 NICE Vol.9 No.1

The catalytic oxidative coupling of methane to ethylene and ethane with manganese oxide catalysts promoted with alkali metal and alkali metallic-chloride has been studied at atmospheric pressure in a fixed bed flow reactor. The main studies of reaction were carrel out over maganese oxide catalysts promoted with sodium chloride and the structure and surface morphology of these catalysts was characterized by an X-ray diffraction and a scanning electron microscope. The powdered MnO₂ was changed into Mn₂O₃ and MnO₂ containing alkali metallic-chlorides was nut changed to n.?w ternary oxides but changed into Mn₃O₄, and/or Mn₂O₃, at higher calcination temperature(above 780℃). The optimum content of NaCl promoted was 10-20 wt%, an in over 10 wt%, the conversion and the selectivity were kept constant. The main factor on deactivation of catalysts was the loss of the promoter(NaCl). The addition of alkali metal salts to manganese oxide catalyst has enhanced C₂(C₂+C₂H_6) selectivity due to neutralizing acid sites more than the electronic factor. It was confirmed that chlorine in a kali metallic-chloride has enhanced the formation of C₂H₄ resulting in a good C₂-yield(up to 25.7%).

A Chromatographic Theory Based on the Concept of a Layer of Equilibrium Adsorption

Row, Kyung Ho,Larin, Alexander V 한국화학공학회 1995 NICE Vol.13 No.6

The LEA model has been analyzed by comparing to other chromatographic theoretical approaches. In the LEA model a layer of equilibrium adsorption, L serves as an effective kinetic constant. For the layer L. the concentration issuing from this layer is in equililhriur with the average value of adsorption on the whole layer at any moment of time. The value of L, is determined from all factors which broaden the chromatographic zone. Such an approach permits us to combine the features of the mass balance (solute Continuity in a chromatographic column), of the mass transfer phenomenon, and of the trdsorption isttherm into a single first order differential equation. Apart from other layer-by-layer models, the LEA modtl supposes that over the whole column a continuous (real) distribution of adsorption a (1, t) and conccruration c (L, t) is observed. The usefulness of the LEA rrudel in developing a chromatographic theory has horn discussed.