• Journal of the Korean Applied Science and Technology
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• v.29 no.3
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• pp.421-428
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• 2012

We investigated an electrochemical properties for Langmuir-Blodgett (LB) nano-films of polyimide and phospholipid mixture. LB films of polyamic acid and phospholipid monolayer were deposited by the Langmuir-Blodgett method on the indium tin oxide(ITO) glass. The electrochemical properties measured by cyclic voltammetry with three-electrode system(an Ag/AgCl reference electrode, a platinum wire counter electrode and LB film-coated ITO working electrode) in $KClO_4$ solution. The current of reduction and oxidation range was measured from 1650 mV to -1350 mV, continuously. The scan rates were 50, 100, 150, 200 and 250 mV/s, respectively. As a result, monolayer LB films of polyamic acid and phospholipid mixture was appeared on irreversible process caused by the reduction current from the cyclic voltammogram. Diffusion coefficient (D) effect in the polyamic acid and phospholipid mixture was used in the LAPC with LLPC fewer than the diffusion coefficient values.

• The Korean Journal of Pharmacology
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• v.23 no.1
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• pp.9-14
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• 1987

The effects of acebutolol and carbamazepine on ouabain-induced arrhythmias were investigated in rabbits. Ouabain produced ventricular arrhythmias which persisted for 7-8 min at the mean dose of $69{\pm}1.3\;{\mu}g/kg$. Ouabain arrhythmias were converted to normal sinus rhythm by administration of acebutolol or carbamazepine singly but lower dosages increased the recovery time. And then, ouabain arrhythmias were effectively converted to normal sinus rhythm and prevented by combined administration of carbamazepine and acebutolol. Each of the combined doses was ineffective when given singly. From the above results, it may be concluded that carbamazepine and acebutolol inhibited the ouabain-induced arrhythmias depending on the level of dosage and showed synergistic interaction.

• Journal of the Korea Convergence Society
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• v.11 no.7
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• pp.157-162
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• 2020

In recent years, laser induced graphene process have been intensively studied for eco-friendly electronic device such as flexible electronics or thin film based energy storage devices because of its simple and effective process. In order to increase the performance and efficiency of an electronic device using such a graphene patterned structure, it is essential to study an optimized laser patterning condition as small as possible linewidth while maintaining the graphene-specific 2-dimensional characteristics. In this study, we analyzed to find the optimal line pattern by using a Ti:sapphire femtosecond laser based photo-thermal reduction process. we tuned intensity and scanning speed of laser spot for generating effective graphene characteristic and minimum thermal effect. As a result, we demonstrated the reduced graphene pattern of 30㎛ in linewidth by using a focused laser beam of 18㎛ in diameter.

• Journal of Soil and Groundwater Environment
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• v.7 no.3
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• pp.95-102
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• 2002

Manganese oxide/ hydrogen peroxide($MnO_2$/${H_2}{O_2}$) reactions were investigated as an alternative to Fenton-like reaction to reduce chlorinated organic compounds in groundwater This system showed high degradation of CT with low ${H_2}{O_2}$concentration($\leq$294mM) at neutral condition, and CT degradation increased with increasing pH values. The rate of CT degradation was not so much dependent on increase in $MnO_2$concentration since increase in production of oxygen during the reaction obstructed reaction of ${H_2}{O_2}$ on the surface of $MnO_2$. These results show that $MnO_2$catalyzed Ponton-like reaction could be a potential alternative method for treating chlorinated organic compounds in groundwater.

• Applied Chemistry for Engineering
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• v.9 no.4
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• pp.475-480
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• 1998

A study on the electrochemical reduction of uranium (VI) to uranium (IV) was carried out in the mixed phases of an organic phase with uranium (VI) and aqueous phase of nitric acid by use of a highly packed glassy carbon (GC) fiber column electrode system, and a model for in-situ electrolytic stripping of uranium (VI) was suggested. The electrochemical reduction of uranium (VI) occurred faster in organic phase than in aqueous phase of the mixed phases. The uranium stripping yield increased and then became constant with the increase of organic flow rate of the electrolytic system due to the increase of diffusion resistance of uranium ions in the organic phase into the aqueous phase. Aqueous flow rate, on the other hand, didn't affect the total uranium (VI) reduction current in the system. The system combined with electrochemical reduction was confirmed to be much more effective than the simple system without it in stripping uranium.

• Applied Biological Chemistry
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• v.34 no.3
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• pp.235-241
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• 1991

Several spices in the range of $1{\sim}3%\;(w/w)$ were added during Kimchi preparation in order to investigate their effects on the chemical changes and fermentation rate. The results showed that addition of red pepper powder by 2% slightly increased the fermentation rate reaching max. value after 36 hours, while 3% addition gradually increased its rate without max. point. Generally higher reducing sugar and acidity were measured for red pepper added Kimchi. The fermentation rate and its max. point were significantly increased as more garlic added and the max. value of ascorbic acid produced was also increased. Little effects were found for Welsh onion and ginger on Kimchi fermentation.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.5
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• pp.472-479
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• 2006

In this research, speciation of phosphorus in sediment and overlying water dependent upon pH and ORP(Oxidation Reduction Potential) was studied. Three possible conditions were simulated: open system with circulation, closed system with stratification and closed system with sand capping on the sediment. Phosphorus release rate from sediment was increased for both open system and closed system if pH was less than 6.0. Phosphorus concentration for closed system was increased from 0.9 mg/L to 0.51 mg/L, and stabilized at 0.34 mg/L if anaerobic conditions were maintained in the overlying water. When sand capping was implemented, phosphorus concentrations of overlying water were maintained less than those of closed system.

• Journal of the Korean Society of Food Science and Nutrition
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• v.12 no.3
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• pp.236-239
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• 1983

The change in total and reducing sugar in germinating mung bean seeds were examined. The mung bean seeds were treated with ash(ash group), gibberellin(gibb group) and chlorocholine cholide(ccc group) ; one group was untreated and used as a control (none group). As germination proceeds, the content of total sugar decreased while the opposite was the case in reducing sugar. The content of total sugar appears in the order of ash group > ccc group>none group> gibb group. The content of reducing sugar in ash group in the highest followed by none group, gibb group and ccc group.

• Journal of the Korean Electrochemical Society
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• v.10 no.4
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• pp.265-269
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• 2007

The effects of experimental variables for the electrochemical reduction of carbon dioxide by Carbon Monoxide Dehydrogenase (CODH) were investigated. It shows the pH optimum at 6.3 where the feasibility of electro-chemical reduction and the stability of CODH compromise each other. The optimum temperature for the reduction was at $60^{\circ}C$ where the enzyme shows the optimum activity although the solubility of carbon dioxide decreases as increasing temperature.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.897-900
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• 2008

Some substances of cement could make underestimate concentration of hexavalent chromium(Cr(VI)) as they reduce Cr(VI) to Cr(III) in acidic condition during the determination of Cr(VI) content in cement. The reduction of Cr(VI) increased with elapsed time after acidification in this study. The reduction rate varied with various cements. From our result, we can conclude that simultaneous additions of acid and DPC were required for the accurate measurement of Cr(VI) in cement. The high recovery rate of 94.3 to 106.7% with the simultaneous acid-DPC addition method can also support our conclusion.