• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.7
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• pp.717-728
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• 2009

In the field of rocket propulsion system hydrogen peroxide has been used as mono-propellant and as the oxidizer of bi-propellants. At the beginning, hydrogen peroxide was used as mono-propellant for thrusters, but later it had been replaced by hydrazine, which has better specific impulse and storability. On the other hand, to drive turbo-pumps, hydrogen peroxide is still being utilized. As the oxidizer of bi-propellants it was used until 1970's and from 1990's hydrogen peroxide once again got back to developer's interest, because one of the recent development purposes of rocket propulsion system is low-cost and ecologically-clean. Until now the storability of hydrogen peroxide has been remarkably improved. The combination of Kerosene/$H_2O_2$ also shows similar accelerating performance to Kerosene/$LO_x$ combination because of higher propellant density and higher O/F ratio, even though the propulsion performance is not as good as the combination of Kerosene/$LO_x$. Moreover, its combustion products are much cleaner than Kerosene/$LO_x$ combination.

• Journal of Aquaculture
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• v.11 no.2
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• pp.223-230
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• 1998

This study was carried out for the purpose of developing environmental friendly and effective chemical treatment method for the disease control in the land-based flounder culture which is industrially popular in the coastal area in Korean. The chemicals such as flounder, Paralichthys olivaceus and their effects on the fish based on the 24hr-$LC_{50}$, $LT_{50}$, 24-hour survival rate at each experimental concentration, recovery rate of the survived individual from chemical treatment, and the histological change of the gill after chemical treatment were investigated and analyzed. The 24hr-$LC_{50}$ was 321.65 ppm for formalin, 419.62 ppm for chlorine dioxide, and 395.97 ppm for hydrogen peroxide, respectively. The $LT_{50}$ was 15-hour for formalin, 17-hour for chlorine dioxide and 24-hour for hydrogen peroxide, respectively. Fishes exposed to the experimental concentration of three chemicals were quickly susceptible in the order of formalin, chlorine dioxide and hydrogen peroxide with a trend of shorter half lethal time at higher concentration. Initial survival rate of the flounder soon after chemical treatment was the highest in the hydrogen peroxide treatment compared with the other two chemicals. The histological damage by the hydrogen peroxide treatment was negligible compared with the other two chemicals. Accordingly, hydrogen peroxide treatment showed the lowest toxicity compared with the other two chemicals to the experimental fishes.

• Journal of Bio-Environment Control
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• v.18 no.3
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• pp.297-301
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• 2009

Hydrogen peroxide, which is used in various crops as an oxidizer to improve high temperature adaptation, was evaluated on the effects on productivity and disease incidence in paprika (Capsicum annuum L.) by periodic leaf spray at summer. Hydrogen peroxide treatment not only increased the leaf thickness and SPAD (chlorophyll content) but also the fruit set numbers per plant by 2. Hydrogen peroxide content increase in leaf resulted in increase of catalase and peroxidase activities, and the powdery mildew disease (Leveillula taurica) was also suppressed by the treatment. Transpiration was improved by the reduced leaf stomata resistance in the hydrogen peroxide treatment. Therefore, hydrogen peroxide leaf spray is recommended for improvement of summer productivity in paprika.

• Journal of the Korean Electrochemical Society
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• v.23 no.3
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• pp.73-80
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• 2020

Fenton oxidation method using hydrogen peroxide is an eco-friendly oxidation method used in water treatment and soil restoration. When removing pollutants by this method, it is quite important to properly regulate the concentration of hydrogen peroxide according to the concentration of the contaminants. In this study, electrochemical biosensors using HRP (horseradish peroxidase) enzymes were manufactured and studies were conducted on the activity of enzymes and the detection characteristics of hydrogen peroxide. HRP were electro deposited with chitosan and AuNP on the working electrode surface of the SPCE (Screen Printed Carbon Electrode). Then, the fixation of enzymes was confirmed using the cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The activity of HRP enzymes was also identified from chronoamperometry (CA) and UV spectroscopy. After immersing the biosensor in PBS solution the current generated from electrodes by titrating hydrogen peroxide was measured from CA analysis. The generated current increased linearly for the concentration of hydrogen peroxide, and a calibration curve was derived that could predict the concentration of hydrogen peroxide from the current.

• Journal of Microbiology and Biotechnology
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• v.18 no.5
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• pp.983-989
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• 2008

Human insulin is a hormone well-known to regulate the blood glucose level. Recombinant preproinsulin, a precursor of authentic insulin, is typically produced in E. coli as an inactive inclusion body, the solubilization of which needs the addition of reducing agents such as $\beta$-mercaptoethanol. To make authentic insulin, recombinant preproinsulin is modified enzymatically by trypsin and carboxypeptidase B. The effects of $\beta$-mercaptoethanol on the formation of human insulin derivatives were investigated in the enzymatic modification by using commercially available human proinsulin as a substrate. Addition of 1 mM $\beta$-mercaptoethanol induced the formation of various insulin derivatives. Among them, the second major one, impurity 3, was found to be identical to the insulin B chain fragment from $Phe_1$ to $Glu_{21}$. Minimization of the formation of insulin derivatives and concomitant improvement of the production yield of human insulin were achieved by the addition of hydrogen peroxide. Hydrogen peroxide bound with $\beta$-mercaptoethanol and thereby reduced the negative effects of $\beta$-mercaptoethanol considerably. Elimination of the impurity 3 and other derivatives by the addition of over 10 mM hydrogen peroxide in the presence of $\beta$-mercaptoethanolled to a 1.3-fold increase in the recovery efficiency of insulin, compared with those for the case without hydrogen peroxide. The positive effects of hydrogen peroxide were also confirmed with recombinant human preproinsulin expressed in recombinant E. coli as an inclusion body.

• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.6
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• pp.1524-1529
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• 2006

The fruits of Cornus officinalis have been used in traditional Oriental medicine for treatment of inner ear diseases, such as tinnitus and hearing loss. In the present study, we showed that the ursolic acid obtained from Corni fructus protected HEI-OC1 auditory cells from hydrogen peroxide cytotoxicity in a dose-dependent fashion. In addition, to investigate the protection mechanism of ursolic acid on hydrogen peroxide cytotoxicity toward HEI-OC1, we measured the effects of ursolic acid on lipid peroxidation and activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPX) in hydrogen peroxide treated cells. Ursolic acid (0.05 - 2 ${\mu}g/ml$) had protective effect against the hydrogen peroxide-induced HEI-OC1 cell damage and reduced lipid peroxidation in a dose-dependent manner. Pre-treatment with ursolic acid significantly attenuated the decrease in activities of CAT and GPX, but SOD activity was not affected by the ursolic acid or hydrogen peroxide. These results indicate that ursolic acid protects hydrogen peroxide-induced HEI-OC1 cell damage through inhibition of lipid peroxidation and induce the antioxidant enzymes CAT and GPX.

• Journal of Physiology & Pathology in Korean Medicine
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• v.25 no.2
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• pp.294-299
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• 2011

The purpose of this study is to investigate effects of Red Ginseng-Ejung-tang (RE) on nitric oxide (NO) and hydrogen peroxide production in RAW 264.7 mouse macrophages induced by lipopolysaccharide (LPS). Cell viability was measured by modified MTT assay. NO production was measured by Griess reagent assay. Hydrogen peroxide production was measured by dihydrorhodamine 123 (DHR) assay. RE did not show cell toxicity against RAW 264.7 for 24 hr incubation at the concentrations of 10, 25, 50, 100, and $200{\mu}g/mL$ in RAW 264.7. RE significantly inhibited NO production for 24 hr incubation at the concentrations of 10, 25, 50, and $100{\mu}g/mL$ in RAW 264.7 (P < 0.05). RE significantly inhibited the LPS-induced production of NO for 24 hr incubation at the concentrations of 10, 25, 50, and $100{\mu}g/mL$ in RAW 264.7 (P < 0.05). RE significantly inhibited the LPS-induced production of hydrogen peroxide for 16, 24, 40, 48, 64, and 72 hr incubation at the concentrations of 50, 100, and $200{\mu}g/mL$ in RAW 264.7 (P < 0.05). These results suggest that RE has anti-inflammatory property related with its inhibition of NO and hydrogen peroxide production in LPS-induced macrophages.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2012.05a
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• pp.100-103
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• 2012

The blending method that is an addition of small quantity of fuel was used to increase the performance of green propellant thruster. 90 wt.% hydrogen peroxide as a green propellant was selected, and ethanol was used as a blended fuel. The o/f ratio was chosen as 50 which has higher theoretical performance than 98 wt.% hydrogen peroxide. The chamber temperature of blended hydrogen peroxide was higher than adiabatic chamber temperature of hydrogen peroxide. Therefore, performance can be improved by ethanol blending. Several catalyst and its support were compared to find appropriate catalyst for decomposition and combustion of ethanol blended hydrogen peroxide. As a experimental results, Pt was suitable, but $MnO_2$ had a chamber instability when it was reused. The ${\alpha}-Al_2O_3$ which is high heat-resistant support showed very unstable performance in both Pt and $MnO_2$ catalyst since it has low decomposition performance.

• Herbal Formula Science
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• v.23 no.1
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• pp.111-119
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• 2015

Objectives : The purpose of this study was to investigate the antioxidant activity of water extract of Woogyuyeum (WGY) in Leydig cells. Methods : We investigated the cytoprotective effect of WGY in cultured mouse Leydig cells by MTT assay. Leydig cells treated with WGY were incubated in the presence or absence of 50 μM hydrogen peroxide at 37℃ for 24 h. The protective effects of WGY against hydrogen peroxide-induced oxidative stress, lipid peroxide (LPO), superoxide dismutase (SOD), and catalase activity assays were performed in Leydig cells. Results : As a result, WGY showed no significant cytotoxicity in Leygdig cells. WGY showed cell viability as 103.65% in 5 μg/ml concentrations. The cytotoxicity induced by hydrogen peroxide in Leygdig cells, the antioxidant effects of WGY was increased in 1, 5, 50, 100 ug/ml concentraions. 100 μg/ml concentration of WGY showed maximum antioxidant effects. Treatment of cells with 100 μg/ml WGY significantly reduced the MDA concentration to 0.23 nmoles/mg protein. SOD activity was increased at 1, 100 μg/ml concentration of WGY and catalase activity was significantly increased at 50, 100 μg/ml concentrations of WGY, respectively. Conclusions : In conclusion, WGY has antioxidant activities against hydrogen peroxide-induced oxidative stress in Leydig cells.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.31 no.4
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• pp.49-57
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• 1999

In CLO2 delignification and bleaching process, formation of chlorate corresponds to a loss of 20-36% of the original CKO2 charge. Because chlorate is inactive and harmful to environmental, it will be of benefit to find methods that can reduce the formation of chlorate during chlorine dioxide bleaching. Chlorate is mainly formed by the reaction HCIO +ClO2 $\longrightarrow$H+ + Cl_ +ClO3-2 On the other hand, AOX in chlorine dioxide bleacing is formed also due to the in-situ produced hypochlorous acid. THus both AOX and chlorate could be reduced by addition of hypochlorous acid. Some paper son the reduction of AOX by additives appeared , but systematic data on chlorate reduction as well as pulp and effluent properties are not available. THus this paper of focused on the effects on the reduction of chlorate and chlorine dioxide bleachability. The additives, fulfamic a챵, AMSO, hydrogen peroxide, oxalic acid were found to eliminate chlorine selectively in chlorine and chlorine dioxide mixture.However, when they were added to bleaching process, sulfamic acid and DMSO showed significant reduction of chlorate formation but hydrogen peroxide and oxalic aicd did not, and significant amount ofhydrogen peroxide was found resided in the bleaching effluent , In addition, sulfamic acid and DMSO decreased the bleaching end ph values while hydrogen peroxide and oxalic acid did not, which also indicated that hydrogen peroxide and oxalic acid were ineffective. The difference might be ascribed to the competitives of hypochlorous acid with lignin, chlorite (CKO2) and additives. Sulfamic acid and DMSO showed better pulpbrightness development but less alkaline extraction efficiency than hydrogen peroxide , oxalic acid and control, which means that insitu hypochlorous acid contributes to the formation of new chromophore structures that can be easily eliminated by alkaline extraction. DMSO decreased the delignification ability of chlorine dioxide due to the elimination of hypochlorous acid, but sfulfamic acid did to because the chlroinated sulfamic acid had stable bleachability. In addition, sulfamic acid, and SMSO shwed decreased color and COD of bleaching effluents, hydrogen peroxide decreased effluent color but not COD content, and oxalic acid had no statistically significant effects. No significant decreases of pulp viocosity were found except for hydrogen peroxide. Based on our results , we suggest that the effectiveness of hydrogen peroxide on the reduction of AOX in literature might be explained by other mechanisms not due to the elimination of hypochlorous acid , but to the direct decomposition of AOX by hydrogen peroxide.