• Clean Technology
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• v.5 no.1
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• pp.20-29
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• 1999

In the treatment of Cu - and CN - contained wastewater by using Fenton oxidation-flocculation-precipitation, the optimal removal efficiencies of the cyanide and copper were investigated according to pH, reaction time, the molar ratio of cyanide and hydrogen peroxide and the mass ratio of ferrous sulfate and hydrogen peroxide for Fenton oxidation, and pH for hydroxide precipitation, respectively. As a result, the $CN^-$ removal efficiency in our experimental wastewater by the Fenton oxidation was 81.2%~99% at its optimal conditions of pH ranging from 3 to 5 and reaction time of 30 minutes. And the optimal dosage of hydrogen peroxide and ferrous sulfate was 214, $428mg/{\ell}$, 107, $161mg/{\ell}$, 214, $214mg/{\ell}$ and 520, $500mg/{\ell}$, respectively when the molar ratio of $Cu^{2+}$:CN is 2:1, 1:1, 1:2, 1:10, and was 900, $1050mg/{\ell}$ when the molar ratio of $Cu^+$: CN is 1:10. When the copper was precipitated by sodium hydroxide after Fenton oxidation, the copper removal efficiency in the wastewater at pH 7 was 98.92%, 98.52%, 92.46%, 90.6% and 95%, respectively.

• Polymer(Korea)
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• v.35 no.5
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• pp.444-450
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• 2011

A high molecular weight natural sodium alginate (HMWSAs) was depolymerized by hydrogen peroxide ($H_2O_2$) with ultrasonic irradiation. The effects of the reaction conditions such as reaction temperature, reaction time, hydrogen peroxide concentration and ultrasonic irradiation time on the molecular weights and the end groups of the depolymerized alginates were investigated. It was revealed that depolymerization occurred through the breakage of 1,4-glycosidic bonds of sodium alginate and the formation of formate groups on the main chain under certain conditions. The changes in molecular weight were monitored by GPC-MALS. The molecular weight of 2 wt% alginate solution decreased from 450 to 15.9 kDa for 0.5 hrs at 50 $^{\circ}C$ under an appropriate ultrasonic irradiation. The PDI(polydispersity index)s of the alginate depolymerized in this study were considerably narrow in comparison with those obtained from the other chemical degradation method. The PDIs were in the range of 1.5~2.5 in any reaction conditions employed in this study.

• Herbal Formula Science
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• v.29 no.1
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• pp.1-8
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• 2021

Objectives : The purpose of this study was to investigate the antioxidant activity of water extract of Ojayeonjonghwan (OYH) in GC-1 germ cell lines. Methods : DPPH radical scavenging activity and cell viability assays in GC-1 germ cell lines were performed. In addition, the protective effects of OYH against hydrogen peroxide-induced oxidative stress in GC-1 germ cell lines were examined by measuring cell viability after H2O2 treatmet. The formation of ROS and the antioxidant enzymes activity such as SOD and catalase were measured in the same condition. Results : OYH scavenged DPPH radical dose-dependent manner and the IC50 was 63.79 ㎍/ml. OYH showed no cytotoxicity at concentration of 1, 10, 100 ㎍/ml. The hydrogen peroxide-induced cytotoxicity of GC-1 germ cell lines was protected to 53.66% by OYH at concentration of 10 ㎍/ml. OYH effectively inhibited ROS production in GC-1 germ cell lines. Mn SOD and catalase protein expression were significantly increased in GC-1 germ cell lines, but Cu/Zn SOD protein expression was not significantly changed. Conclusions : In conclusion, OYH has antioxidant activities against hydrogen peroxide-induced oxidative stress in GC-1 germ cell lines.

• Transactions of the Korean hydrogen and new energy society
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• v.32 no.6
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• pp.514-523
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• 2021

This study investigated the effect of anode fuel composition on the performance of direct borohydride/hydrogen peroxide fuel cells (DBHPFCs). The effect of sodium borohydride (NaBH₄) and sodium hydroxide (NaOH) concentrations on fuel cell performance was determined through fuel cell tests. Fuel cell performance increased with an increase in the NaBH₄ concentration, whereas it decreased with an increase in the NaOH concentration. The anode fuel composition was selected as 10 wt% NaBH₄+10 wt% NaOH+80 wt% H₂O based on the fuel viscosity, electrochemical reaction rate, and decomposition reaction rate. DBHPFCs were also tested to analyze the effect of operating temperature and operation time on fuel cell performance. The present results can be used as a reference basis to determine operating conditions of DBHPFCs.

• The Journal of Korean Obstetrics and Gynecology
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• v.25 no.2
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• pp.12-22
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• 2012

Objectives: The aim of this study is to investigate immune enhancing effect of Houttuyniae Herba water extract(HW) on RAW 264.7 cell of mouse macrophages. Methods: Effects of HW on productions of nitric oxide(NO) and hydrogen peroxide($H_2O_2$) in RAW 264.7 mouse macrophages were measured. Effect of HW on production of cytokines such as interleukin(IL)-$1{\beta}$, IL-6, and tumor necrosis factor(TNF)-${\alpha}$ in RAW 264.7 cells was accessed by a multiplex bead array assay based on xMAP technology. All of results were represented P<0.05 compared to the normal. Results: 1. After 24 hr incubation, HW increased significantly NO production in RAW 264.7 cells at the concentrations of 25, 50, 100 and 200 ${\mu}g$/mL. 2. After 24 hr incubation, HW increased significantly hydrogen peroxide production in RAW 264.7 cells at the concentrations of 25, 50, 100 and 200 ${\mu}g$/mL. 3. After 24 hr incubation, HW increased significantly IL-$1{\beta}$ production in RAW 264.7 cells at the concentrations of 100 and 200 ${\mu}g$/mL. 4. After 24 hr incubation, HW increased significantly IL-6 production in RAW 264.7 cells at the concentrations of 100 and 200 ${\mu}g$/mL. 5. After 24 hr incubation, HW increased significantly TNF-${\alpha}$ production in RAW 264.7 cells at the concentrations of 50, 100, and 200 ${\mu}g$/mL. Conclusions: These results suggest that HW has immune enhancing activity related with its increasement of NO, hydrogen peroxide, IL-$1{\beta}$, IL-6, and TNF-${\alpha}$ in macrophages.

• Horticultural Science & Technology
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• v.34 no.3
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• pp.383-395
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• 2016

This study investigated the effect of exogenous hydrogen peroxide ($H_2O_2$) on the antioxidant responses and growth of warm-season turfgrass (Zoysia japonica Steud.) and cool-season turfgrass (Poa pratensis L.) subjected to drought stress. Compared with control plants that were not pretreated with $H_2O_2$, plants pretreated with $H_2O_2$ had significantly greater fresh and dry weights of shoots and roots, and increased water content. $H_2O_2$ pretreatments before drought stress significantly decreased the concentrations of malondialdehyde and $H_2O_2$. DPPH radical scavenging and glutathione activities were significantly increased. The responsive activities of the antioxidant enzymes superoxide dismutase, ascorbate peroxidase, catalase, and peroxidase were also significantly enhanced. Our results suggest that exogenous $H_2O_2$ could improve the growth of warm-season and cool-season turfgrass under drought stress by increasing the activity of their antioxidant enzymes, while decreasing lipid peroxidation.

• The Korea Journal of Herbology
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• v.25 no.1
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• pp.83-91
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• 2010

Objectives : In this study, we compared the anti-oxidant and anti-inflammatory activities of Curcumae longae Radix (CLRa) and Curcumae longae Rhizoma (CLRh). Methods : We performed 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and 2,2-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) cation scavenging assays, and determined total polyphenolic content to examine the anti-oxidant effects of CLRa and CLRh. We also evaluated the anti-oxidant effects of CLRa and CLRh against hydrogen peroxide ($H_2O_2$)-induced toxicity in PC12 cells using thiazolyl blue tetrazolium bromide (MTT) and reactive oxygen species (ROS) assays. Next, to compare the anti-inflammatory effects of CLRa and CLRh against lipopolysaccharide (LPS)-induced inflammation in microglia BV2 cells, we measured nitric oxide (NO) assay and inducible nitrite synthase (iNOS) using Western blotting analysis. Results : CLRa showed higher activity in DPPH and ABTS assays and lower total polyphenolic contents compared with CLRh. In PC12 cells, CLRa and CLRh showed no difference in H2O2-induced cell toxicity and ROS overproduction. In BV2 cells, CLRa showed higher effect than CLRh in NO and iNOS production induced by LPS. Conclusions : These results demonstrate that CLRa has higher radical scavenging activities and anti-inflammatory effect in BV2 cells comparing CLRh. However, CLRa and CLRh have no effect and no difference in $H_2O_2$-induced toxicity.

• Proceedings of the Korean Society of Toxicology Conference
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• 2003.05a
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• pp.91-92
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• 2003

Oxidative stress induced by reactive oxygen intermediates (ROIs) has been implicated in a variety of human diseases including cancer, diabetes, rheumatoid arthritis and neurodegenerative disorders. Hydrogen peroxide ($H_2O$$_2$), a representative ROI which is produced during the cellular redox process, can cause cell death via apoptosis and/or necrosis depending on its concentrations. (omitted)

• Journal of the Korean Ceramic Society
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• v.56 no.3
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• pp.302-307
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• 2019

The intrinsic oxygen-vacancy defects in ZnO have prevented the preparation of p-type ZnO with high carrier concentration. Therefore, in this work, the effect of the concentration of H₂O₂ (used as an oxygen source) on the oxygen-vacancy concentration in ZnO prepared by atomic layer deposition was investigated. The results indicated that the oxygen-vacancy concentration in the ZnO film decreased by the oxygen-rich growth conditions when using H₂O₂ as the oxygen precursor instead of a conventional oxygen source such as H₂O. The suppression of oxygen vacancies decreased the carrier concentration and increased the resistivity. Moreover, the growth orientation changed to the (002) plane, from the combined (100) and (002) planes, with the increase in H₂O₂ concentration. The passivation of oxygen-vacancy defects in ZnO can contribute to the preparation of p-type ZnO.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.04a
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• pp.318-321
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• 2003

This study explored the feasibility of applying Electrokinetic-Fenton process(EK-Fenton process) to remediation of contaminant sorbed on the soil possessed low-permeability. The addition of 0.01 N H$_2$SO$_4$ in the anode reservoir for the $H_2O$$_2$stabilization improved the stabilization of $H_2O$$_2$and the treatment effect of phenanthrene across the entire soil specimen. The use of $H_2O$$_2$and dilute acid as anode purging solution is a promising method treating of HOCs in low-permeability subsurface environments.