• KSBB Journal
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• v.11 no.5
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• pp.511-517
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• 1996

An amphiphilic phase enzyme reaction was used to synthesize alkyl glucosides from glucose and alkyl alcohol with immobilized ${\beta}$-glucosidase using four glycol ether cosolvents(monoglyme, diglyme, 2-methoxyethanol, and 1,4-dioxane). Monoglyme was shown to be the best cosolvent for the amphiphilic phase medium composed of water/cosolvent/alkyl alcohol admixture. To obtain high yield of alkyl glucoside by amphiphilic phase enzyme reaction, hydrophilicity-hydrophobicity of amphiphilic media and enzyme microenvironment was optimized from the viewpoints of substrate solubility, enzyme activity, water activity, and dynamic equilibrium between glucose alcoholysis and glucoside hydrolysis. Under optimum reaction conditions, the highest concentrations of hexyl, octyl, decyl, and dodecyl glucosides were 18.2, 9.68, 7.27, and 6.03g/L, respectively.

• Journal of the Korean Institute of Gas
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• v.26 no.2
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• pp.14-20
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• 2022

In this study, the catalytic reaction characteristics for producing hydrogen using methanol steam reforming were investigated. Nickel and copper are frequently used in steam reforming reaction and methanol synthesis, were used as main active metals. As a support, hydrotalcite has a high specific surface area, excellent porosity and thermal stability, and has weak Lewis acid sites and basic properties. Hydrotalcite was used to identify catalysts of methanol steam reforming with catalytic activity and their properties. In this research, high reactivity was shown in the catalyst of copper metal with high reducibility. And increasing of active metal loading showed the higher the methanol conversion and hydrogen selectivity.

• Microbiology and Biotechnology Letters
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• v.26 no.1
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• pp.1-6
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• 1998

The characteristics of $CO_2$ fixation by Chlorella HA-1 cultured in bubble columns were studied to achieve high photosynthetic rates per basal area. The influence of experimental conditions such as the diameter of a bubble column and gas flow rate, on photosynthesis of Chlorella HA-1 was investigated. The maximum productivity and the overall $CO_2$ fixation rate obtained in a 0.15 L bubble column was 1.09 g dry biomassa-day and 1048 g CO$_2/\m^2$-day, respectively. Light limitation has been observed in the bubble columns having a diameter larger than 3.5 cm.. As the reactor volume increased, the decrease of the $CO_2$ fixation rate was remarkable. High gas flow rate was helpful to mitigate the light limitation problem.

• KSBB Journal
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• v.9 no.3
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• pp.239-245
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• 1994

The effects of reaction temperature and the level of hydration(water activity) were studied for gas phase reactions of alcohol oxidase and alcohol dehydrogenase immobilized on DEAE-cellulose and controlled pore glass(CPG). Optimum reaction temperature zone of gas phase reaction was similar to that of aqueous phase reaction. The activity of alcohol oxidase increased dramatically and the stability decreased when the water activity was increased from 0.3 to 0.8. The apparent activation energies of the gas phase reaction decreased approaching the values obtained in the aqueous phase reaction as the water activity increased. In the both cases of alcohol oxidase and alcohol dehydrogenase, the rate constants of the gas phase reaction were lower than those of aqueous phase reaction by two orders of magnitude and these results could be correlated to the vapor-liquid equilibrium data of the substrate, ethanol.

• Tuberculosis and Respiratory Diseases
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• v.45 no.2
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• pp.341-350
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• 1998

Background: Airway hyperreponsiveness is a cardinal feature of asthma. It consists of both an increased sensitivity of the airways, as indicated by a smaller concentration of a constrictor agonist needed to initiate the brochoconstrictor response and an increased reactivity, increments in response induced subsequent doses of constrictor, as manifested by slopes of the dose-response curve. The purpose of this study is to observe the relationship between bronchial sensitivity and reactivity in asthmatic subjects. Method: Inhalation dose-response curves using methacholine were plotted in 56 asthmatic subjects. They were divided into three groups(mild, moderate and severe) according to clinical severity of bronchial asthma. PC20 were determined from the dose-response curve as the provocative concentration of the agonist causing a 20% fall in FEVl. PC40 were presumed or determined from the dose response curve, using the PC20 and the one more dose after PC20. Reactivity was calculated from the dose-response curve regression line, connecting PC20 with PC40. Results: PC20 were 1.83mg/ml in mild group, 0.96mg/ml in moderate, and 0.34mg/ml in severe. PC40 were 7.l7mg/ml in mild group, 2.34mg/ml in moderate, and 0.75mg/ml in severe. Reactivity were $24.7{\pm}17.06$ in mild group, $46.1{\pm}22.l0$ in moderate, and $59.0{\pm}5.82$ in severe. There was significant negative correlation between PC20 and reactivity (r= -0.70, P<0.01). Conclusion: Accordingly, there was significant negative correlation between bronchial sensitivity and brochial reactivity in asthmatic subjects. However, in some cases, there were wide variations in terms of the reactivity among the subjects who have similar sensitivity. So both should be assessed when the bronchial response tor bronchoconstrictor agonists is measured.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2001.11a
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• pp.59-63
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• 2001

인간의 각성은 감성의 한 차원을 차지하여 인간의 작업수행의 효율성에 미치는 영향을 끼치고 있다. 각성의 정확한 측정 및 분석은 인간의 작업에 생산성 극대화를 제시할 수 있다. 그러나 각성은 자극유형에 따라 모드(mode)가 다르게 나타난다. 본 연구는 이러한 각성의 유형에 따른 생리신호의 반응을 측정하여 각성별 정량화 방법을 제시하고자 한다. 20명의 대학생이 각기 다른 각성 자극인 신체적 각성 및 인지적 각성이 유발되었고, 그에 따른 생리신호 반응을 측정, 분석하였다. 결과적으로 각성의 유형은 중추신경계 및 자율신경계 별로 각각 다른 반응을 보였다.

• Journal of the Microelectronics and Packaging Society
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• v.1 no.1
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• pp.33-40
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• 1994

금속박막 증착 전 Ar 이온을 이용한 폴리이미드 표면의 RF 스퍼터링 처리가 Cr/폴 리이미드 계면의 접착력과 반응성에 미치는 영향에 대하여 90。 peel test, TEM, FTIR 및 XPS를 사용하여 연구하였다. Cr/폴리이미드 계면의 접착력은 촐리이미드 표면은 RF 스퍼 터링 처리에 의해 1g/mm에서 100g/mm로 현저히 증가하였다. 표면 비저항 측정과 FTIR 및 XPS 분석결과 RF 스퍼터링 처리에 의한 Cr/폴리이미드 계면의 접착력 증가는 RF 스퍼 터링에 의한 폴리이미드 표면의 chemical modification 에 의해 증착되는 Cr과 계면 반응성 이 향상되는데 기인하는 것임을 밝혔다.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2012.11a
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• pp.107-107
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• 2012

연료전지 분리판용 모재로서 사용되고 있는 스테인레스 스틸에 대해서는 많은 연구가 진행되어 왔으나, 알루미늄은 거의 연구가 진행되지 않고 있다. 따라서 이번 연구는 DC 반응성 마그네트론 스퍼터링법으로 알루미늄 기판 위에 TiN, TiCN 박막을 반응성 가스 유량별로 증착하여, 기계적 특성 및 내부식성 특성을 비교 검토하였다.

• Journal of the Korean Chemical Society
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• v.65 no.1
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• pp.62-66
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• 2021

• Korean journal of applied entomology
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• v.60 no.4
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• pp.363-367
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• 2021

This study was conducted to investigate the EAG (electroantennogram) response of Spodoptera frugiperda male to sex pheromone compounds and whether or not S. frugiperda male adults would undergo double mating. The EAG response of S. frugiperda male adult to Z9-14:Ac increased in a dose-dependent as the dose increased. Among the 7 sex pheromone components investigated, male EAG recording was the highest to Z9-14:Ac. The EAG response of S. frugiperda male adult to the mixed sex pheromone component was greater than that to the single component. Male adults of S. frugiperda were capable of double mating under laboratory condition, and the secondary mating rate increased to 72.2% compared to the 58.3% of primary mating rate. The EAG response of mated S. frugiperda male adult was not different from that of unmated S. frugiperda male. In the net house test with sex pheromone lure, mated male adults were not captured during the test period. Also, strangely, unmated male adults were not captured even in a trap equipped with virgin female adults, although the antennae of mated male adult were responded to the sex pheromone component in the laboratory. Probably, it is thought that the mated male adults may not have been caught in the trap be due to flight ability which has been decreased after mating. The field attractiveness of S. frugiperda male adults to sex pheromones remains to be further elucidated.