• Journal of Physiology & Pathology in Korean Medicine
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• v.17 no.6
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• pp.1524-1527
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• 2003

In this study, we demonstrated the antioxidant effect of the Caesalpinia sappan L. extract through the scavenging effect against 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical and the protective effect on protein damage and PC12 cells against cupric ion/hydrogen peroxide. Its IC/sub 50/ value of the scavenging effect against DPPH radical was 7.7 ㎍. Protection of its extract against oxidative bovine serum albumin (BSA)damage induced by hydrogen peroxide was more effective than that of vitamin C. The protective effect on PC12 cells by hydrogen peroxide was shown to be more potent in is extract than in vitamin C. DNA fragmentation analysis also supports this result.

• Transactions of the Korean hydrogen and new energy society
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• v.31 no.1
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• pp.41-48
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• 2020

The present study discussed the thermodynamic analysis of the hydrogen liquefaction process to build a hydrogen liquefaction pilot plant with a small capacity (0.5 ton/day). A 2-stage Brayton cycle utilizing LNG/LN2 cold energy was suggested to be built in Korea for the hydrogen liquefaction pilot plant with a small capacity. Thermodynamic analysis on the effect of various variables on the efficiency of hydrogen liquefaction process was performed. As a result, the CASE in which the ortho-para conversion catalyst was infiltrated inside the heat exchanger showed the best process efficiency. Finally, thermodynamic analysis was performed on the effect of turbo expander compression ratio on the hydrogen liquefaction process and it was confirmed that an optimal turbo expander compression ratio exists.

• Journal of the Korean institute of surface engineering
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• v.45 no.5
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• pp.212-217
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• 2012

High strength steel sheets used for automobile outer-panels have been intensively studied for developing a lightweight automobile under a strong pressure of the requirements for enhancing the mileage and energy saving in production of automobile parts. It is known that high strength steels are susceptible to hydrogen embrittlement, The susceptibility to hydrogen embrittlement increases with increasing its strength. However, the effect of hydrogen on the fracture behavior of high strength steels, though investigated extensively, has not been fully understood. In this paper, hydrogen was charged with 590DP steels by electrochemical method and its content was measured by hydrogen determinator with the different charging conditions. It was shown that the SP energy and maximum load decreased with increasing charging time. The results of SEM-fractography investigation for the hydrogen contained samples showed that a small portion of dimples on cleavage-fractured surface were observed and the size of the dimples were decreased with increasing hydrogen charging time.

• Journal of Environmental Health Sciences
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• v.31 no.2 s.83
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• pp.115-119
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• 2005

This study was performed to investigate inhibitory effect on growth of Staphylococcus aureus and Bacillus cereus in lactic acid, hydrogen peroxide and combination of lactic acid and hydrogen peroxide. The minimun inhibitory concentration (MIC) of lactic acid in Staphylococcus aureus were 2500 ppm at pH 7.0, 1250 ppm at pH 5.5, 6.0 and 6.5, while in Bacillus cereus 625 ppm at pH 5.5 and 6.0, 1250 ppm at pH 6.5 and 7.0, respectively. MICs of hydrogen peroxide in Staphylococcus aureus were 50 ppm at pH 6.0, 75 ppm at pH 6.5 and 7.0, while in Bacillus cereus was 75 ppm at pH 5.0, 5.5 and 6.0, respectively. MICs of combined treatment of lactic acid and hydrogen peroxide in Staphylococcus aureus were 1250 ppm of lactic acid with 25 ppm of hydrogen peroxide and 625 ppm of lactic acid with 50 ppm of hydrogen peroxide. When Bacillus cereus were with 1250 ppm of lactic acid with 50 ppm of hydrogen per-oxide and 625 ppm of lactic acid with 75 ppm of hydrogen peroxide at 6.5. The correlations between MICs of lactic acid and hydrogen peroxide in S. aureus and B. cereus obtained through the coefficient of determination ($R^2$). $R^2$ value were 0.9934 and 0.9986, respectively. The inhibitory effect of lactic acid and hydrogen peroxide in S. aureus and B. cereus could be confirmed from the result of this experiment.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.160-160
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• 2011

In this work, magnesium (Mg) nanoparticles were plated onto the surfaces of multi-walled carbon nanotubes (MWNTs) in order to investigate the effects of their presence on the high pressure hydrogen storage behaviors of the resultant Mg/MWNTs. The structure of Mg/MWNTs was characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The pore structure and total pore volumes of Mg/MWNTs were analyzed by $N_2$/77 K adsorption isotherms. The hydrogen storage behaviors of the Mg/MWNTs were investigated by BEL-HP at 298K and 100 bar. From the results, it was found that Mg particles were homogeneously distributed on the MWNT surfaces. The hydrogen storage capacity increased in proportion to the Mg content. It can be concluded that Mg paricles play an important role in hydrogen storage characteristics due to the hydrogen spillover effect.

• Journal of Physiology & Pathology in Korean Medicine
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• v.23 no.5
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• pp.1049-1054
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• 2009

The effect of Sacchromyces cerevisiae-Fermented Sophorae Radix water extract (SFS) on production of hydrogen peroxide and nitric oxide (NO) from mouse macrophage Raw 264.7 Cells treated with nicotine (1 mM) was investigated through this study. SFS (0, 25, 50, 100, 200, 400 ug/mL) was simultaneously treated with nicotine (1 mM) during culture of 4, 20, 24, 44, 48, 68, and 72 hr. And the intracellular productions of hydrogen peroxide were measured by dihydrorhodamine 123 (DHR) assay. NO production after 24 hr treatement was measured with Griess reagent assay. SFS restored the production of hydrogen peroxide and NO reduced by nicotine (1 mM) in Raw 264.7 Cells. These results suggests that SFS could be supposed to have the immunological activity concerned with macrophage's oxidative burst including hydrogen peroxide and NO.

• Journal of Physiology & Pathology in Korean Medicine
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• v.26 no.4
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• pp.491-496
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• 2012

The purpose of this study is to investigate the modulatory effect of wogonin on hydrogen peroxide production in human blastoma SH-SY5Y cells induced by the synthetic analog of double-stranded RNA [polyinosinic-polycytidylic acid]. Hydrogen peroxide production was measured by dihydrorhodamine 123 (DHR) assay. Wogonin significantly inhibited the polyinosinic-polycytidylic acid (PIC)-induced production of hydrogen peroxide for 0.5, 2, 12, 18, and 24 hr incubation at the concentrations of 10, 25, and 50 ${\mu}M$ in SH-SY5Y (P < 0.05) in dose dependent manner. These results suggest that wogonin has neuroprotective property related with its inhibition of hydrogen peroxide production in PIC-induced neuronal cells.

• Transactions of the Korean hydrogen and new energy society
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• v.21 no.1
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• pp.12-18
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• 2010

Photobiological hydrogen production using Rhodobacter sphaeroides KD131 was studied on the effect of light intensities and nitrogen sources. Media containing malate and glutamate were shown higher hydrogen production rate than that containing succinate and $(NH_4)_2SO_4$ at the $110\;W/m^2$ illumination by halogen lamp at $30^{\circ}C$. Media lacking glutamate as the nitrogen source exhibited higher hydrogen production than that containing glutamate. Initial cell concentration was optimized to 1.0 at the absorbance of 660 nm. Hydrogen production was increased by increasing the light intensity from 0 to $216\;W/m^2$ but the increasing rate declined over $108\;W/m^2$.

• 한국신재생에너지학회:학술대회논문집
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• 2009.11a
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• pp.231-231
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• 2009

In this work, we prepared the Ni-loaded porous SBA-15 (SBA-15) by a depositionprecipitation (D-P) method, in order to enhance the hydrogen storage capacity. The structure and morphology of the Ni/SBA-15 were characterized by X-ray diffraction (XRD) and field emission transmission electron microscopy (FE-TEM). The results showed that, at the Ni loading used at the DP times in the range of 0-120 min, SBA-15 preserved the well-ordered hexagonal porous arrangement. The textural properties of the Ni/SBA-15 were analyzed using N2 adsorption isotherms at 77 K. Specific surface area and mesopore volume of the samples were determined from the Brunauer-Emmett-Teller (BET) equation and Barrett-Joiner-Halenda (BJH) method, respectively. The hydrogen storage capacity of the Ni/SBA-15 was evaluated at 298 K/10 MPa. The hydrogen storage capacity of the Ni/SBA-15 was increased in accordance with Ni content. Consequently, it was found that the presence of Ni on mesoporous SBA-15 created hydrogen-favorable sites which enhanced the hydrogen storage capacity by spillover effect.

• Transactions of the Korean hydrogen and new energy society
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• v.34 no.6
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• pp.698-711
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• 2023

Consequence analysis using an ALOHA program is conducted to calculate the accidental impact ranges in the cases of hydrogen leakage, explosion, and jet fire in a hydrogen fueled combined cycle power plant. To evaluate the effect of weather conditions and topographic features on the damage range, ALOHA is executed for the power plants located in the inland and coastal regions. The damage range of hydrogen leaked in coastal areas is wider than that of inland areas in all risk factors. The obtained results are expected to be used when designing safety system and establishing safety plans.