• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2001.09a
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• pp.194-199
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• 2001

Lap splice in plastic hinge region is inevitable because of due to constructional joint between footing and column. R/C Circular columns with lap-splice in plastic hinge region are widely used in Korean highway bridges. In addition, these columns which constructed before the seismic design code have a number of structural deficiencies. It is, however, believed that there are not many experimental research works for nonlinear behavior of these columns subjected to earthquake motions. The object of this research is to evaluate the seismic performance of existing circular reinforced concrete bridge piers by the Quasi-static test. Existing reinforced concrete bridge piers were moderate seismically designed in accordance with the conventional provisions of Korea Highway Design Specification. This study has been performed to verify the effect of lap spliced longitudinal steel, confinement steel type and confinement steel ratio far the seismic behavior of reinforced concrete bridge piers. Quasi-static test has been done to investigate the physical seismic performance of RC bridge piers, such as displacement ductility, energy absorption, strength degradation etc.

• Publications of The Korean Astronomical Society
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• v.20 no.1 s.24
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• pp.7-10
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• 2005

We have calculated 2448 interstellar cloud models to investigate the formation and destruction of high rotational level $H_2$ according to the combinations of five physical conditions: the input UV intensity, the $H_2$ column density, cloud temperature, total density, and the $H_2$ formation rate efficiency. The models include the populations of all the accessible states of $H_2$ with the rotational quantum number J < 16 as a function of depth through the model clouds, and assume that the abundance of $H_2$ is in a steady state governed primarily by the rate of formation on the grain surfaces and the rates of destruction by spontaneous fluorescent dissociation following absorption in the Lyman and Werner band systems. The high rotational levels J = 4 and J = 5 are both populated by direct formation into these levels of newly created molecules, and by pumping from J = 0 and J = 1, respectively The model results show that the high rotational level ratio N(4)/N(0) is proportional to the incident UV intensity, and is inversely proportional to the $H_2$ molecular fraction, as predicted in theory.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.4
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• pp.568-574
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• 2000

Phytofluene was subjected to ozonolysis in ice-cold dichloromethane. The ozonolysis products were fractionated with a silica column and the carbonyl fraction was analyzed by ODS-HPLC with a photodiode array detector. Phytofluene was solubilized in 5% tween 40, and then oxidized by incubating under dim yellow light at 37$^{\circ}C$, 24 hr with continuous shaking. Carbonyl compound and acidic compound were produced. In comparison with autoxidation and ozonolysis, each compound showed the same retention time and UV-vis spectra were identical to the reference cleavage products prepared by ozeonolysis of phytofluene. Absorption spectrum of acidic compound was similar to that of standard 4,5-didehydrogeranyl geranyl acid which is known to possess biological activity. Thus, eccentric cleavage of phytofluene was confirmed to occur in vitro under oxidation condition.

• Journal of the Korean Society of Visualization
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• v.9 no.3
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• pp.59-64
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• 2011

In this study the change of free surface vortex is expressed through the time volume fraction using multiphase unsteady condition in sump, because in previous studies of the pump sump did not represent the behavior of the free surface vortex exactly due to the reason it was calculated using single phase and steady condition. The reliability of the computational analysis is verified through comparing experimental results with that of present numerical analysis. Homogeneous free surface model is used to apply interactions of air and water. The results show that the free surface vortex can be identified on the isotropic surface at air volume fraction 1%~5%. The vortices make an air column from the free surface to the sump intake and are created and destroyed repeatedly. The behavior of free surface vortex at numerical analysis is quite similar to experimental test. The result of vortex motion according to time, works on a cycle.

• Applied Biological Chemistry
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• v.16 no.2
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• pp.53-59
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• 1973

The anthocyanins in Santa rosa plum (widely growing var. in Korea) were extracted with 0.5% methanolic HCl and purified with Amberlite IRC-50 cation exchange resin. The individual pigments were separated by paper chromatography. The two pigments were identified as cyanidin-3-monoglucoside and cyanidin-3-xyloglucoside based on the following evidence: Rf values in various solvents, partical acid hydrolysis, stepwise hydrolysis, sugar moiety, alkaline degradation, and absorption spectra in the visible region. Cyanicin-3-monoglucoside was the abundant pigment of the plum.

• Bulletin of the Korean Space Science Society
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• 1995.10a
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• pp.30-30
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• 1995

We present the results of analysis on the X-ray observations of the binary X-ray pulsar Her X-I. made with ASCA/SIS on August 13-14. 1993. An eclipse transition from ingress to egress was fully covered by the observations. The main findings are as follows; (1) a model of power-law plus black-body is required to interpret the entire eclipse spectrum. and the black-body component appears at < 0.7 keV. (2) the power-law continuum which has photon index ${\alpha}\;=\;{0.84^{\;+0.14}}_{\;-0.19}$ is very similar to that of detected by Ginga/LAC (${\alpha}\;=\;0.80\;{\pm}\;0.04$), (3) the calculated eclipse flux of $2^{-10}\;keV.{\;}~{\;}1.8{\pm}10^{-11}{\;}ergs{\;}cm^{-2}s^{-1}$, is consistent with the Ginga observation carried out in the high intensity state ~2.0{\pm}10^{-11}{\;}ergs{\;}cm^{-2}s^{-1}$, (4) there is no significant absorption feature. and an upper limit of the aborption column $NH{\;}\leq{\;}3{\pm}10^{20}\;cm^{-2}$ is determined at the 90% confidence limit. Based on these results, we suggest that extended matter surrounding the binary system should be existed persistently with stable conditions, and scattering of the source continuum by the matter is responsible for the eclipse emission.ission.

• Journal of the Society of Naval Architects of Korea
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• v.30 no.4
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• pp.23-30
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• 1993

This rape deals with the experimental and theoretical investigations on the aerodynamic performance of the Wells turbine. The two-dimensional cascade theory is used to estimate the thrust and torque of turbine, and finally to yield an efficiency of turbine. The turbine is assumed to rotate with a constant rotational speed in a sinusoidally varying unsteady flow field. Experimental approach is made in a wave simulator, producing a sinusoidally reciprocating air flow corresponding to the wave motion in an Oscillating Water Column(OWC) chamber. Performance data of turbine measured at various operating conditions are analyzed and compared to numerical results in order to understand the overall features of a Wells turbine.

• Journal of Advanced Marine Engineering and Technology
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• v.26 no.2
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• pp.256-263
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• 2002

The Boil-Off-Gases(BOG) in the LNG production terminal are continuously generated during the unloading, storage and supply processes by the heat penetration. In order to use these gases as useful fuel, the reliquefaction process should be installed to put the reliquefied BOG in the main LNG supply line before the secondary pump in terminal. The current reliquefaction method of BOG in LNG terminal is the direct contact one between LNG and BOG in the absorption column. But the system has severe disadvantage, which is the 10 times of LNG circulation needed for unit mass of BOG reliquefaction. It causes, therefore, high power consumption of LNG circulation pump and excessive city-gas supply, even if short demand of NG is needed in the summer time. In this paper, the new reliquefaction system of BOG by using LNG cold energy with indirect contact in precooler was suggested and analysed. The result showed new indirect contact method of BOG reliquefaction system between LNG cold energy and BOG is much more effective than the current direct contact one because of only about 1.3 times of LNG circulation needed and higher energy saving by pump power reduction.

• Korean Journal of Environmental Agriculture
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• v.23 no.4
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• pp.251-257
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• 2004

Analytical methods were developed to determine cyclosulfamuron residues in soil, water, rice grain and straw using high-performance liquid chromatography (HPLC) with ultraviolet absorption detection. In these methods, cyclosulfamuron was extracted with aqueous $Na_2HPO_4$/acetone and acetone/methanol mixture from soil and rice samples respectively. Liquid-liquid partition coupled with ion-associated technique, Florisil column chromatography, and solid-phase extraction (SPE) were used to separate cyclosulfamuron from interfering co-extractives prior to HPLC analysis. For water sample, the residue was enriched in $C_{18}$-SPE cartridge, cleaned up in situ, and directly subjected to HPLC. Reverse-phase HPLC under ion-suppression was successfully applied to determine cyclo-sulfamuron in sample extracts with the detection at its ${\lambda}_{max}$ (254 nm). Recoveries from fortified samples averaged $87.8{\pm}7.1%$ (n=12), $97.3{\pm}7.2%$ (n=12), $90.8{\pm}6.6%$ (n=6), and $78.5{\pm}6.7%$ (n=6) for soil, water, rice grain and straw, respectively. Detection limits of the methods were 0.004 mg/kg, 0.001 mg/L, 0.01 mg/kg and 0.02 mg/kg for soil, water, rice grain and straw samples, respectively.

• Preventive Nutrition and Food Science
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• v.2 no.2
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• pp.83-88
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• 1997

Anthocyanin pigments of purple sweet potato roots (Ipomoea batatas L.) were extracted with 0.5% TFA (Trifluoroacetic acid) in 95% EtOh, and further isolated an purified by Amberlite XAD-7 and ODS column chromatography, and final preparative HPLC. Among nine anthocyanins isolated, the structure of three major anthocyanins were identified as 3-O-(6-O-trans-caffeyl)-2-O-(6-O-trans-caffeylglucopyranosyl)-$\beta$-D-glucopyranosyl-5-O-($\beta$-D-glucopyranosyl)-peonidin, 3-O-(6-O-trans-caffeyl)-2-O-(6-O-trans-feruloyl-glucopyranosyl)-$\beta$-D-glucopyranosyl-5-O-($\beta$-D-glucopyranosyl)-peonidin, and 3-O-(6-O-trans-caffeyl)-2-O-(6-O-p-hydroxylbenzoylglucopyranosyl)-$\beta$-D-glucopyranosyl)-peonidin, by using UV-visible absorption spectra, $^1$H-NMR and FAB-MS analysis.