• The Bulletin of The Korean Astronomical Society
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• v.43 no.1
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• pp.72.1-72.1
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• 2018

Recently, an analysis of 3-micron spectra of CH4 line emission from our Gemini/GNIRS observations of Jupiter's polar regions yielded an unexpected result: The homopause (~1 microbar pressure level) located directly above the long-lasting 8-micron CH4 north-polar hot spot (Great 8-micron Hot Spot: GHS) is cool compared with the temperatures of nearby auroral regions (Kim et al. 2017). Most of the 8-micron emission of the GHS originates from CH4 at the ~1 mbar level (i.e., deeper in the stratosphere, where cooling time is several years), much longer than at the altitude of the homopause. We propose a mechanism to explain the temperature difference: locally-fixed and transient, but energetic auroral particles, which can penetrate to the 1 mbar level and deposit energy there creating and maintaining the GHS. For Saturn, thus far we have not detected distinctive 8-micron nor 3-micron CH4 hot spots in the polar regions. We will present a possible implication for this difference between Jupiter and Saturn.

• Journal of the Korean Chemical Society
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• v.39 no.10
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• pp.769-775
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• 1995

The reaction between $CH_3$ radicals and $O_2$ was investigated in incident shock waves at temperatures between 1390 and 2250 K and densities from 1.5 to 5.3 mol/$m^{+30/3}$ using azomethane as a source of methyl radicals by following the consumption of CH3 radicals with time resolved UV absorption measurements at 213.9 nm. The rate constant expression $k_2=1.35{\times}10^{12}\;exp( - 5900 K/T)\;cm^3 mol^{-1}s^{-1}$ for the reaction of $CH_3 + O_2{\rightarrow}CH_2O + OH$ was derived.

• YAKHAK HOEJI
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• v.41 no.1
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• pp.126-131
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• 1997

To overcome the problems of the resistance to clavulanic acid, many researchers are developing novel inhibitors that are not sensitive to new mutant ${\beta}$-lactamases. In order to evaluate newly synthesized compound CH2150 (Sodium (3S.5R)-6(Z)-[1-{1-(2-{2-benzoxazoly}thioethyl)-l.2,3-txiazol-4-yl}methylene] penicillanate-1,1-dioxide) as a ${\beta}$-lactamase inhibitor, we examined inhibitory activity of CH2150 against ${\beta}$-lactamases of clinical isolates resistant to ampicillin/sulbactam(12 strains of Escherichia coli and 13 strains of Staphylococcus aureus), and compared with that of sulbactam. Nitrocefin was used as substrate for ${\beta}$-lactamases, and the increase of absorbance was measured spectrophotometerically at 482 nm. ${\beta}$-Lactarnase inhibition of CH2150 against ${\beta}$-lactamases was 73 ~ 96% in E. coli and 76 ~ 79% in S. aureus. Comparatively, that of sulbactam was 96 ~ 100% and 96 ~ 100%, respectively. The inhibitory activity of CH2150 was slightly lower than that of sulbactam. The MIC values of ampicillin combined with CH2150 (2:1) for the clinical isolates were 4~512 ${\mu}$g/ml for E. coli and 1.0 ~ 64 ${\mu}$g/ml for S. aureus, whereas 0.5~16 ${\mu}$g/ml for E. coli and 0.25~8 ${\mu}$g/ml for S. aureus when combined with sulbactam (2:1).

• KSBB Journal
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• v.9 no.4
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• pp.372-377
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• 1994

To improve L-lysine yield, pyrimidine base analogue(6-azauracil)-resistant mutants were isolated from Corynebacterium glutamicum KFCC10672 Among them the best producer, C. glutamicum CH0516, was selected and tested for L-lysine production in a $7\ell$ fermentor. It was found that the product yield obtained with C. glutamicum CH0516 was higher than that of the parent strain by 3%. In order to elucidate the gain in productivity with the 6-azauracil-resistant mutant enzymatic kinetic parameters such as aspartokinase(AKase) and aspartate carbamoyltransferase (ATCase) were measured. The Km values of AKase with C. glutamicum KFCC10672 and CH0516 were 200.0 mM and 166.7 mM and those of ATCase were 0.13 mM and 0.27 mM, respectively. However, the specific enzyme activities of AKase of C. glutamlcum KFCC10672 and CH0516 were $3.89{\times}10^{-1}$ units/mg and $4.78{\times}10^{-1}$ units/mg, and those of ATCarse were 2.20 units/mg and 1.84 units/mg, respectively. It appears that some increase in product yield with C. gluramicum CH0516 is likely due to the increased Akase activity and decreased ATCase activity.

• Applied Chemistry for Engineering
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• v.17 no.6
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• pp.638-643
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• 2006

Pyrolytic reaction study of dichloromethane ($CH_{2}Cl_{2}$) in excess hydrogen was performed to investigate pyrolytic reaction pathways at a pressure of 1 atm with residence times of 0.3~2.0 sec in the temperature range of $525{\sim}900^{\circ}C$. A constant feed molar ratio $CH_{2}Cl_{2}$:$H_{2}$ of 4:96 was maintained through the experiment. Reagent loss and product formation were monitored by using an on-line gas chromatograph, where batch samples were analyzed by GC/MS. Complete destruction(99%) of the parent reagent was observed at temperature near $780^{\circ}C$ with residence time over 1 sec. Major products observed were $CH_{3}Cl$, $CH_{4}$, $C_{2}H_{4}$, $C_{2}H_{6}$, and HCl. Minor products included $CHClCCl_{2}$, CHClCHCl, $CH_{2}CHCl$, and $C_{2}H_{2}$. The pyrolytic reaction pathways to describe the important features of intermediate product distributions and reagent loss, based upon thermodynamic and kinetic principles, were suggested. The results of this work provided a better understanding of pyrolytic decomposition processes which occur during the pyrolysis of $CH_{2}Cl_{2}$ and similar chlorinated methanes.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.09a
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• pp.288-289
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• 2005

• Journal of Food Hygiene and Safety
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• v.16 no.3
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• pp.188-193
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• 2001

To evaluate antimicrobial activities of chongkukjang slime fermented by different strains, growth characteristics were compared using various standard microorganisms with addition of chongkykjang slime. Chonghkjang slime was prepared by fermenting cooked soybean after inoculating with Bacillus circulans K-1, Baciilus spp N-1 and Bacillus subtilis CH-1, respectively. Significant antimicrobial activity was observed by chongkukjang slime on gram positive bacteria (Staphylococcus aureus, Bacillus cereus, Bacillus subtilis, Micrococcus luteus), gram negative bacteria(Escherichia coli O157:H7, Salmonella Typhimurium, Pseudomonas fluorescens), and yeast (Pichia membranaefaciens, Saccharomyces cerevisiae, Candida albicans). In case of B. cereus growth inhibition of 80% was achieved by the addition of chongkukjang slime; on the contrary, to Escherichia coli O157:H7 only 20% inhibition was observed. Slime from Bacillus subtilis CH-1, in particular, inhibition of 40% toward bacteria and yeast, whereas slime from Bacillus circulans K-1, Bacillus spp N-1 showed only 20% inhibition.

• YAKHAK HOEJI
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• v.51 no.6
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• pp.495-499
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• 2007

Seven epoxy- and hydroxyandrostane derivatives ($DH-1{\sim}DH-7$) and nine epoxy- and hydroxycholestane derivatives ($CH-1{\sim}CH-9$) with unsaturation in ring A and ring B were synthesized from DHEA and cholesterol, respectively. The antinociceptive effects of all synthesized compounds were measured by hot plate method. Most of androstane derivatives except $1{\alpha},2{\alpha}$-epoxy-4,6-androstadiene-3,17-dione (DH-3), and CH-6, CH-7 and CH-9 exhibited antinociceptive effect. 1,4-Androstadiene-$3{\beta},17{\beta}$-diol (DH-5, 100 mg/kg, $35.8{\pm}7.39$), $6{\alpha},7{\alpha}$-epoxy-1,4-androstadiene-3,17-dione (DH-4, 100 mg/kg, $32.6{\pm}5.50$) and $5{\alpha},6{\alpha}$-epoxy-17-oxo-androstan-$3{\beta}$-ol (DH-1, 100 mg/kg, $32.5{\pm}2.98$) were more effective than morphine (10 mg/kg, $30.6{\pm}0.5$). The analgesic effects of androstane derivatives on acetic acid writhing in mice were lower than aspirin. The androstane derivatives were less effective than ibuprofen at inhibiting effects on the carrageenin induced paw oedema. 4,6-Cholestadien-$3{\beta}$-ol (CH-5), $1{\alpha},2{\alpha}$-epoxy-4,6-cholestadien-$3{\beta}$-ol (CH-7) and $7{\alpha}$-hydroxy4-cholesten-3-one (CH-9) showed the decrease of serum triglyceride and total cholesterol levels in poloxamer P-407 injected rat.

• Membrane Journal
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• v.24 no.1
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• pp.1-9
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• 2014

In this study, four soluble homo- and co-polyimides using 5-(2,5-dioxotetrahydrofuryl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride (DOCDA) and 4,4'-diaminodiphenyl ether (ODA) monomers were synthesized to develop the gas separation membrane with good $CO_2/CH_4$ separation properties. To prepare the copolyimides, 20 mol% of three dianhydrides - (4,4'-(hexafluoroisoproplidene)diphthalic anhydride (6FDA), 4,4'-biphthalic anhydride (BPDA), 3,3',4,4'-benzophenone tetracarboxylic dianhydride (BTDA) - were added in DOCDA-ODA monomer mixture, respectively. All the synthesized homo- and co-polyimides were characterized by FT-IR. Their thermal properties were analyzed with differential scanning calorimeter (DSC). Dense membranes were prepared from these copolyimides to check their gas permeation properties for $CO_2$ and $CH_4$ gases using a time-lag method. The permeation testing results are as follows; DOCDA/ODA homopolymer showed 1.71 barrer of $CO_2$ permeability and 74.35 of $CO_2/CH_4$ selectivity. The three polyimide copolymers (DOCDA/6FDA-ODA, DOCDA/BPDA-ODA, DOCDA/BTDA-ODA) showed lower $CO_2/CH_4$ selectivities and higher $CO_2$ permeabilities than the homopolymer (DOCDA-ODA). DOCDA/6FDA-ODA showed twice times higher $CO_2$ permeabilities without severe $CO_2/CH_4$ selectivity loss than the DOCDA-ODA.

• Journal of the Korean Society of Costume
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• v.21
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• pp.49-59
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• 1993

Actual conditions of current shroud are as follows. 1. The kinds of shroud in formal funeral cer-emonies were more variable than infor-mal ceremonies. 2. The cloths of the shround were all Myongchu or all Sambe inside and outside or the inside was Sambe and the outside was Myongchu. The color was light color center upon the white color and black Kongtan was used mostly in Myokmok. 3. Terms of the shroud were different in each region. 4. The kinds of recommended men's shroud were Ch ksam, Ch kori, Naeko, Ko, Torumaki, Topo, Topotae, Mal, Myokmok, Aksu, Ch'im, Ch' nkum, Chiyok, Ryomp'o, Soryomkum, Haengch n, Onang, Tae, Taennim, Pokk n, Kwatu, tec. And the kinds of recommended women's shroud were Ch ksam, Ch kori, Soksokkos, Ko, Tansokkos, Naesang, Oesang, Turumaki, Wonsam, Wonsamtae, Mal, Myokmok, Aksu, Ch'im, Ch' nkum, Chiyok, Ryomp'o, Onang, Soryomkum, Kwatu, etc.