• Proceedings of the Korean Biophysical Society Conference
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• 2002.06b
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• pp.9-11
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• 2002

Plasma membrane Na$^{＋}$-K$^{＋}$ ATPase (pump) is an essential component to maintain asymmetrical ion distribution across cell membrane. The Na$^{＋}$-K$^{＋}$ ATPase was discovered by Jens C. Skou in 1957 and since then physiological and biochemical properties of the enzyme have been extensively studied. Jens C. Skou was awarded the 1997 Nobel Prize in chemistry for his discovery of the Na $^{＋}$ - $K^{＋}$ ATPase.(omitted)

• Bulletin of the Korean Chemical Society
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• v.7 no.6
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• pp.416-421
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• 1986

The solvent coordination effect on the excited state processes of Mg(II)- and Zn(II)-phthalocyanines has been described. The triplet state of these compounds decays with mixed first and second order kinetics or mainly second order kinetics depending on the solvents used. The first order component of the rate constants decrease along with the series, dimethylsulfoxide (5-coordinated), 1-chloronaphthalene (4-coordinated) and piperidine (6-coordinated), while the second order rate constant is dependent on the diffusion rate constant of the solvents. The excited state quenching by methylviologen or p-benzoquinone is discussed. And ion recombination rate constant is given.

• Journal of Environmental Health Sciences
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• v.20 no.4
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• pp.1-9
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• 1994

In order to investigate the regional level of air pollutants at Kangwha island situated on the western coast in Korea, the suspended particulate matter samples were collected by using the low volume air sampler on ten interval from March 1992 to February 1993 and the mass concentration of suspended particulate matter (SPM) and the chemical composition of water-soluble major ionic components in SPM samples were measured. During the sampling period, the average concentration of SPM under diameter 10 $\mu$m was found to be 48 $\mu$g/m$^3$ (+ 12). The seasonal concentration of SPM was showed in order of spring>fall>winter>summer. It was considered that higher concentration on spring than other season was affected by the long-range transport of Yellow sand particulate from China continent and lower concentration on summer by the washout and rainout effect of large rainfall. The content of water-soluble component in SPM samples was founded to be about 31% (14.69 $\mu$g/m$^3$) and 65% was unknown or unanalyzed. The content of cationic component showed in order of NH$_4^+$ (44.6%)>Na$^+$ (21.2%)>K$^+$ (14.7%)>Ca$^{2+}$ (13.6%)>Mg$^{2+}$ (5.9 %) and the content of anionic component SO$_4^{2-}$ (62.5%)>NO$_3^-$ (22.3%)>Cl$^-$ (15.2%), respectively. This fact indicates that ammonium and sulfate ion of water-soluble component in SPM sample were dominant in this region. From the chemical composition of water-soluble component, the most of Na$^+$, Mg$^{2+}$ and Cl$^-$ were originated from seawater source but K$^+$, Ca$^{2+}$ and SO$_4^{2-}$ were originated from other non-marine source. The contribution of seasalt to the composition of precipitation was 23%.

• Applied Microscopy
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• v.45 no.4
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• pp.242-248
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• 2015

In this paper, three carbon sources, i.e., solid graphite, gaseous CH4 and liquid ethanol, and one solid silicon source were employed to synthesize SiC/C nanocomposite powders by arc-discharge plasma. The processing conditions such as the component ratios of raw materials, atmospheric gases, etc. were adjusted for controllable synthesis of the nanopowders. It is indicated that both of solid graphite and silicon can be co-evaporated and reacted to form nanophases of cubic ${\beta}$-SiC with ~50 nm in mean size and a little free graphite; the carbon atoms decomposed from gaseous $CH_4$ favor to combine with the evaporated silicon atoms to form the dominant SiC nanophase; liquid carbon source of ethanol can also be used to harvest the main ${\beta}$-SiC and minor 6H-SiC phases in the assembly of nanoparticles. The as-prepared SiC/C nanocomposite powders were further purified by a heat-treatment in air and their photocatalytic performances were then greatly improved.

• Korean Journal of Soil Science and Fertilizer
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• v.34 no.4
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• pp.237-244
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• 2001

Investigation on the surface charge properties of some Korean arable soils was performed by ion adsorption technique with two kinds of indifferent ion ($Na^+$ and $K^+$) at the range of pH 3 to 9 in bulk solution. The contribution of soil components(organic matter, oxides and clay mineral) on the surface charge density was determined at two soil depth with different solid particle composition When the pH of solution increased, the negative charge of soil surface was increased among the all soils, but positive charge were not appeared above pH 6. apparently. The magnitude of surface charge density measured by NaCl adsorption method showed ra nges of $0.01{\sim}2.84cmol_c{\cdot}kg^{-1}$ and $7.41{\sim}12.20cmol_c{\cdot}kg^{-1}$ at pH 3 and pH 9, respectively. Ion adsorption method using KCl as index ion overestimated than the method using NaCl as index ion. The content of organic matter is the strongest factor on the value of dCEC/dpH.

• Applied Chemistry for Engineering
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• v.5 no.6
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• pp.949-956
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• 1994

The objective of this study is to experimentally investigate the ion exchange characteristics of five types of Zeolite(Zeolite-A, 13X, Y, Mordenite, Chabazite) for effective removal of Cs, Sr and Co ions in water solution at low concentration(0.01 N and 0.005 N). Total ion exchange capacity and equilibrium isotherm are measured, and free-energy change(${\Delta}G^0$) and enthalpy change(${\Delta}H^0$) in ion exchange reaction are calculated from experimental results. In addition the ion exchange equilibrium in the three-component system for three types of zeolite showing better efficiency is measured and plotted in triangle coordinates. It is shown from experimental results that the magnitude of free-energy change increases with the increasing ion selectivity, and the difference of free energy change between ions correlates closely with that of ion selectivity. The results also shows that Chabazite is effective for the adsorption of Cs ion, and Zeolite-A and Zeolite-13X for that of Sr and Co ions.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.11
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• pp.1111-1115
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• 2008

The characterization of PM$_{2.5}$ and PM$_{10}$ concentration is considered by analysis of ionic and heavy metal component to measured suspended particle at atmosphere in Hoseo university of Asan area. The variation of concentration is studied at the periods of asian dust occured. In asian dust, the PM$_{2.5}$ ratio is decreased from 79.7% to 40.1%, whereas the size-classified mean concentration of suspended particle is increased largely. It is found that the PM$_{2.5}$ ratio is decreased relatively because the coarse particle is increased largely according to the analysis of the mass concentration to divide the fine and coarse particle on 2.1 $\mu$m basis. It is observed that the Ca$^{2+}$ion is about 40 magnifications and Na$^+$, SO$_4{^{2-}}$ ion is increased in sequence in coarse particle, whereas the variation of ionic concentration is slightly increased in the fine particle. Furthermore, Mn, Fe, Zn, and Al are increased in sequence as the result of heavy metal component analysis, and Al is shown the most increased as mass concentration.

• Journal of Physiology & Pathology in Korean Medicine
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• v.29 no.4
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• pp.305-312
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• 2015

Paeonol is a major component found in the Paeoniaceae family such as Paeonia suffruticosa Andrews. Paeonia suffruticosa Andrews has traditionally been used to enhance blood flow and relieve joint pain in east Asian countries including China, Korea and Japan. Current research has shown that paeonol blocked the voltage-gated sodium channel and L-type calcium channel. However, there is a lack of research to reveal the relation between cardiac function and blockade of ion channels by paeonol. Therefore, the aim of this study is to investigate whether paeonol has anti-arrhythmic effects via modulating cardiac ion channels. It is collected that the effects of paeonol on multiple ion channels such as the fast sodium channel and L-type calcium channel from published papers. To incorporate the information on multi-channel block, we computed the effects using the mathematical cardiac model of the guinea-pig and rat ventricular cells (Noble 1998 and 1991 model) and induced early after-depolarizations (EADs) to generate an arrhythmia in the whole heart. Paeonol slightly shortened the action potential duration in the normal cardiac ventricular action potential by the inhibition of sodium channel and L-type calcium channel. Paeonol presented the protective effect from EADs by the inactivation of sodium channel but not L-type calcium channel. Paeonol did not show any changes when it treated on normal ventricular cells through the inhibition of sodium channel, but the protective effect of paeonol through sodium channel on EADs was dose-dependent. These findings suggest that paeonol and its original plant may possess anti-arrhythmic activity, which implies their cardioprotective effects.

• Korean Journal of Food Science and Technology
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• v.49 no.6
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• pp.591-598
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• 2017

This study aimed to evaluate the measurement uncertainty for the quantitative determination of chlorite and chlorate in ready-to-eat fresh-cut vegetables using ion chromatography with a hydroxide-selective column. One gram of the homogenized sample in deionized water was sonicated and centrifuged at 8,500 rpm. The supernatant was purified by passing it through a Sep-Pak tC18 cartridge, followed by chromatographic determination using a Dionex IonPac AS27 column. The linearity of the calibration curves, recovery, repeatability, and reproducibility of the method were satisfactory. The method detection limit was estimated to be approximately 0.5 mg/kg. Each uncertainty component was evaluated separately, and the combined and expanded uncertainty values were calculated at the 95% confidence level. The measured concentrations for 3 mg/kg of chlorite and chlorate standard materials were $3.18{\pm}0.32$ and $3.10{\pm}0.42mg/kg$, respectively. These results confirmed the reliability of the developed method for measuring the two chlorine-based oxyanions in fresh-cut vegetables.

• Textile Coloration and Finishing
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• v.18 no.1
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• pp.10-19
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• 2006

Despite several recent attempts to measure the concentration of individual catechins by HPLC, it has not been so easy to separate catechins accurately. The aim of the present work is to provide a proper condition for separating each component of catechins by HPLC analysis, and also to evaluate the experimental variables including color differences, and metal ion contents after dyeing and mordanting. Four kinds of Catechins, (-)-epicatechin(EC), (-)-epicatechin gallate(ECG), (-)-epigallocatechin(EgC), (-)-epigallocatechin gllate(EgCG) were isolated from the residues after dyeing. Catechins in Korean green tea leaves are richer when e tea leaves are younger. Higher concentration of catechins owes it to e way it is processed. The contents of catechins adsorbed in silk fabrics after dyeing were in order of EGCG>ECG>EGC>EC. We have found $68\%$ uptake of EGCG, and 116.8mg of EGCG in the silk fabrics after it was dyed with $1\%$ Korean green tea extracts. The absorbance intensity and K/S values of dyed silk fabrics were increased with dyeing temperature and time. Only the surface color of the silk fabric dyed with green tea extracts was yellowish red, but it changed from yellowish red to red with an increase in the mordant concentration. Post-mordanted silk fabrics with ferrous sulfate changed from yellowish red to red and purple color shade. In a practical evaluation, there is no significant change in color after twenty times of the continuous dry cleaning process. However, post-mordanted fabrics with ferrous sulfate faded the brightness of color after dry cleaning. Dyeing silk fabrics with a Korean tea extract reduced the metal ion contents in the silk fabrics when compared to the untreated silk fabrics. Metal contents in silk fabrics dyed and post-mordanted with $1\%$ each metal solution were 0.194 ppm for Aluminum, 1.601ppm for Copper, and 0.334 ppm for Iron. After the post-mordanting process, the heavy metal ion absorption increased, which was mainly attributed to the catechins and polyphenols in dyed silk fabrics.