• 한국가스학회:학술대회논문집
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• 2003.10a
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• pp.95-101
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• 2003

• 한국가스학회:학술대회논문집
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• 2007.04a
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• pp.24-26
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• 2007

• Proceedings of the Korean Ceranic Society Conference
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• 2003.04a
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• pp.101.2-101
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• 2003

• Applied Chemistry for Engineering
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• v.9 no.1
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• pp.94-100
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• 1998

Methane, the major constituent of natural gas, had been converted to higher hydrocarbons by a microwave plasma. The yield of C2+ product could be increased from 29.2% to 42.2% with increasing plasma power(40~120 watt) and decreasing flow rate(40~5 mL/min) of methane. With catalyst, the selectivities of ethylene and increased while yield of C2+ remaining constant. Among various catalysts, Fe catalyst showed the highest ethylene selectivity of 30%. A natural gas could produce more C2+ than a pure methane. This is due to high reactivity of ethane and propane in the natural gas.

• Korean Chemical Engineering Research
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• v.46 no.4
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• pp.692-696
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• 2008

There is not much method of using C4 Raffinate III, despite having high olefin contents. The majority of the C4 Raffinate III have been converted into n-butane through hydrogenation, and sold as LPG. The C4 Raffinate III is rich 2-butenes with very low isobutene and isobutene contents. The 2-butenes are converted into 1-butene in the vicinity of thermodynamic equilibrium yield through positional isomerization with n-almumina catalyst calcinated at $400{\sim}600^{\circ}C$. The overall process is composed of isomerization-reactor, de-1-buteneizer to prepare the reactants and to enrich reactive products, and 1-butene column to product a high purity 1-butene. The production of 1-butene increases by 40~60 wt% with the selective positional isomerization from the existing separation method.

• Journal of Food Hygiene and Safety
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• v.4 no.3
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• pp.171-176
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• 1989

A rapid, simple method of ELISA was applied for the determination of aflatoxin BI in cereals from Y oungnam districts. Antibodies obtained cross reacted with aflatoxin B2 and to a less extent with other aflatoxin BI analogs. Response range for a typical standard curve was between I and 100 ppb. Fewer interference by spiked methanol-PBSdimethylformamide extracts ofrice was evidenced. Contents of aflatoxin BI from rice (65) and barley (116) were determined by competitive direct enzyme- linked immunosorbent assay as follows. Three out of 65 rices samples were positive. Rice samples of R-IS, R-30, and R-59 represent the aflatoxin B1 levels of $7.5\;\mu\textrm{g}.kg,\;6.0\;\mu\textrm{g}/kg,\;3.5\;\mu\textrm{g}/kg,\;3.3\;\mu\textrm{g}/kg$, respectively, and showed 4.6% aflatoxin BI contamination in rice samples. Meanwhile, four out of 116 barley samples were positive. VB-37 showed the highest aflatoxin Bllevels of $9.6\;\mu\textrm{g}/kg$ and VB-35, VB-15 and VB-54 represent $7.5\;\mu\textrm{g}.kg,\;6.0\;\mu\textrm{g}/kg\;and\;3.6\;\mu\textrm{g}/kg$, respectively, and showed 3.4% aflatoxin B1 contamination in barley samples.

• Korean Chemical Engineering Research
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• v.57 no.6
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• pp.812-825
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• 2019

Two dolomite samples mined from the different mines were calcined using a batch-type microwave kiln ($950/60min^{\circ}C$) to produce $CaO{\cdot}MgO$. The hydration of the $CaO{\cdot}MgO$ samples shows different reactivity. MgO was separated by reacting with a strong acid cation exchange resin using the reactivity of the hydration properties of light dolomite ($CaO{\cdot}MgO$). Calcium ($Ca-(R-SO_3)_2$) was separated from the prepared $CaO{\cdot}MgO$ by the cation exchange resin ($CaO{\cdot}MgO:R-SO_3H=1:12mass%$). High purity MgO (higher than 94 mass %) with unburned $CaCO_3$ (1~2 mass %) was obtained by the separation process. The separated MgO was heated at $950^{\circ}C$ for 60 minutes to afford high purity MgO with MgO content higher than 96%. And High-grade $CaCO_3$ was prepared from the reaction with calcium adsorbed resin ($Ca-(R-SO_3)_2$) and NaOH, $CO_2$ gas.

• Science of Emotion and Sensibility
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• v.22 no.1
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• pp.55-64
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• 2019

Stress is accompanied by changes in the responses of the autonomic nervous system, and the heart rate variability (HRV) index is a quantitative marker that reflects autonomic responses induced by stressors. In this study, we observed changes in the autonomic responses induced by combinations of 30% oxygen administration and color light for stress relaxation. In all, 42 participants produced stress symptoms over the preceding two weeks, as rated on the stress response scale. After stress assessment, they were exposed to three therapeutic conditions, and electrocardiogram (ECG) signals were recorded before, during, and after therapy. The three therapy conditions consisted of only 30% oxygen administration with white light, a combination of 30% oxygen and orange light, and a combination of 30% oxygen and blue light. The HRV indices extracted from ECG signals were heart rate (HR), the standard deviation of the RR interval (SDNN), the mean square root of consecutive RR interval difference values (RMSSD), the low frequency component of HRV (LF), the high frequency component (HF), and the LF/HF ratio. These indicators were used to compare mean values before and after therapy. The results showed that HR and the LF/HF ratio were significantly lower after therapy than before it. In particular, the condition with 30% oxygen and blue light yielded significantly greater RMSSD and HF increases, as well as decreases in LF/HF ratio than in other two conditions. Our results suggest that therapy with 30% oxygen and blue light is the most effective for the relaxation of stress, which implies autonomic balance by parasympathetic activation.

• Journal of Life Science
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• v.14 no.3
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• pp.501-508
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• 2004

A bacterial strain CJ-3 which produced chitinase was isolated from Korean traditional soy sauce. Using 16S rDNA analysis, the strain CJ-3 was identified as Bacillus atrophaeus. The approximate molecular weight of the putative chitinase enzyme was 31.0 kDa and the enzyme activity was remarkably induced by addition of colloidal chitin (0.5, 1.0, 2.0%). The antioxidant activity was increased 53% by the browning reaction products of B. atrophneus CJ-3. Escherichia. coli lipopolysaccharides (LPS)-induced production of nitric oxide(NO) was reduced up to 45% by the browning reaction product in RAW264.7 macrophage. Inhibition of cell viability in the presence of LPS was recovered to normal level by the browning reaction product. These results suggest that browning reaction of B. atrophaeus CJ-3 plays an important role for activation of immune system. B. atrophaeus CJ-3 exhibited optimum temperature and pH of 37$^{\circ}C$ and pH 7.0∼8.0, respectively. The major intracelluar free amino acid was determined to be glutamate.

• KSBB Journal
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• v.23 no.5
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• pp.369-374
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• 2008

The effects of reaction temperature and the addition of various detergents on the enantioselective hyrolysis activity of the recombinant Escherichia coli containing the epoxide hydrolase (EH) gene of Rhodotorula glutinis were investigated for the production of enantiopure styrene oxide. The recombinant E. coli harboring the EH gene from R. glutinis exhibited the enantiopreference toward (R)-styrene oxide with the maximum hydrolytic activity of $165.04{\mu}mol/min/mg$ of dry cell weight (dcw). The addition of 0.5% (w/v) Tween 20 at $10^{\circ}C$ increased the initial hydrolysis rate and enantioselectivity by 1.45-fold and 2.0-fold, respectively. Enantiopure (S)-styrene oxide was prepared with 99% ee enantiopurity and 46.0% yield (theoretical yield=50%) from 20 mM racemic styrene oxide.