• Proceedings of the KIPE Conference
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• 2002.11a
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• pp.89-93
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• 2002

Hydrogen - Oxygen gas has obtained from water electrolysis reaction. It is mixed gas havingconstant volume ratio 2:1 Hydrogen and Oxygen, and it is used as a source of thermal energy by combustion reaction. This gas has betterristics in the field of economy, efficiency of energy, and environmental intimacy than used both of acetylene gas and LPG for gas welding machin. So nowdays many studies of Water-Electrolyzed gas are progressed, and commercially used as a source of thermal energy for gas welding In the industry. For Water-Electrolyzed Source, it was used diode rectifier or SCR rectifier for get DC source. This method which is not looking to improve a source for impossible current control or voltage and limited control intervals. In this paper, it was relized and designed in source of pulse type for complementing existing-DC source type, also by experiment it was acquired producting characteristics of Hydrogen -Oxygen Gas through feature of source

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.33 no.1
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• pp.37-44
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• 2023

Transition metal (Me = Cu, Fe, Ni) doped (Pr, Ba)Co₂O_5+𝛿 (PBCO) material were investigated in terms of electronic structure change and electrochemical properties. It was confirmed that (Pr, Ba)(Co, Cu)O_5+𝛿 (PBCCu) and (Pr, Ba)(Co, Fe)O_5+𝛿 (PBCFe) showed cubic and orthorhombic structures, respectively, but (Pr, Ba)(Co, Ni)O_5+𝛿 (PBCNi) showed secondary phases. PBCCu has an average particle diameter of 1093 nm, and PBCO and PBCFe have an average particle diameter of 495.1 nm and 728 nm, respectively. The average oxidation values of B site ions in PBCMe were calculated to be 3.26 (PBCO), 2.48 (PBCCu), 3.32 (PBCFe), and valence band maximum (VBM) was -0.42 eV (PBCO), -0.58 eV (PBCCu), -0.11 eV (PBCFe). It is expected that PBCCu easily interacts with adsorbed oxygen due to the lowest oxidation value and the highest VBM. The polarization resistance was 0.91 Ω cm² (PBCO), 0.77 Ω cm² (PBCCu), 1.06 Ω cm² (PBCFe) at 600℃, showing the lowest polarization resistance of PBCCu.

• Electrical & Electronic Materials
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• v.9 no.9
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• pp.918-924
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• 1996

A downstream oxygen plasma is generated by capacitively coupled RF power and applied to photoresist stripping. Stripping rate (ashing rate) is measured in terms of RF power, chamber pressure, oxygen flow rate and temperature. Ashing reaction is thermally activated and depends on oxygen radical density. The ashing process is optimized to have the high ashing rate, good uniformity and minimal plasma damage using a statistical method.

• Journal of the Korean Chemical Society
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• v.13 no.4
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• pp.249-261
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• 1969

Studies of photochemical reactions of the pure oxygen atmosphere are made using reaction rate constants and atmospheric data available in the latest literature. The daytime and nighttime variations in atomic oxygen and ozone are computed, based on three different conditions: 1) photochemical equilibrium, 2) direct integrations of the rate equations with modifications and approximation to the equations, and 3) by numerical integrations. The departure from the photochemical equilibrium concentrations during day and nighttime are discussed by comparing the results obtaind from the three conditions.

• Bulletin of the Korean Chemical Society
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• v.16 no.1
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• pp.21-26
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• 1995

Electrochemical reduction of oxygen has been carried out at glassy carbon electrode and carbon ultramicroelectrode, the surface of which is modified with a new Co(Ⅱ)-Schiff base complex, Co(Ⅱ)-3,4-bis(salicylidene diimine)toluene in 1 M KOH solution. The results obtained from cyclic voltammetric and chronoamperometric experiments are consistent with the formation of the reasonably stable superoxide ions as a primary electron transfer reaction product. The exchange rate constant obtained for oxygen reduction is about 0.02 cm/s.

• Applied Chemistry for Engineering
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• v.18 no.4
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• pp.361-365
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• 2007

The precipitation reaction of some rare earth chlorides ($Ce/Nd/GdCl_3$) in a LiCl-KCl molten salt has been carried out by reaction with oxygen. Identification of rare earth precipitates by reaction with oxygen and effects of oxygen sparging time (max. 420 min) and molten salt temperature ($450{\sim}750^{\circ}C$) on conversion were investigated. In this study, regardless of the oxygen sparging time and the molten salt temperature, oxychlorides (REOCl) for $NdCl_3$ and $GdCl_3$, and an oxide ($REO_2$) for $CeCl_3$ are formed as a precipitate, which are identical with the estimation results of Gibbs free energy of reaction (${\Delta}G_r$). The conversion of rare-earth chlorides into insoluble precipitates was described by using a conversion ratio. The conversion ratio increased exponentially with the oxygen sparging time and finally showed asymptotic value, over 0.999 at $750^{\circ}C$ of the molten salt temperature and over 300 min of sparging time conditions. The conversion ratios were increased with the molten salt temperature. In case of $CeCl_3$, when the sparging time exceed 60 min, the values of the conversion ratio were nearly constant over 0.999 in all experimental temperature conditions.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.28 no.3
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• pp.281-288
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• 2004

Combustion using oxygen enriched air is an energy saving technology that can increase thermal efficiency by improving the burning rate and by increasing the flame temperature. Flame figures, OH radical intensities, temperature distributions and emissions concentration were examined according to oxygen enriched concentration(OEC) in a turbulent diffusion flat flame. As long as the oxygen enriched concentration was increased, the length and volume of the flat flame was decreased while OH radical intensity was raised and the flame temperature was increased. However, RMS of the fluctuating temperature was decreased, and more homogeneous temperature field was formed. Thermal NO also was increased with increase of oxygen enriched concentration, but CO was decreased due to the increase of chemical reaction rate.

• Biomedical Science Letters
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• v.15 no.2
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• pp.153-160
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• 2009

Photodynamic therapy(PDT) is a treatment utilizing the generation of singlet oxygen and other reactive oxygen species(ROS), which selectively accumulate in target cells. The aim of present work is to investigate the photodynamic therapy mechanism of 9-HpbD-a-mediated PDT in HeLa cell lines. We studied the general reactive oxygen species(G-ROS) activation after 9-HpbD-a PDT using fluorescence stain with $H_2DCF-DA$. G-ROS activation observed after 9-HpbD-a PDT and higher activation condition was 1 hour after PDT at 0.5 ${\mu}g/ml$ 9-HpbD-a concentration. Sodium azide and reduced glutathione(the singlet oxygen quencher) could protect HeLa cells from cell death induced by 9-HpbD-a PDT. But D-mannitol(the hydroxyl radical scavenger) could not protect cell death. Singlet oxygen played a decisive role in 9-HpbD-a PDT induced HeLa cell death. Type II reaction was the main type of ROS formation at 9-HpbD-a PDT.

• Nuclear Engineering and Technology
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• v.31 no.6
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• pp.541-547
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• 1999

Corrosion control, in the end-shield cooling system of Wolsung Nuclear Power Plant, is directly related to the control of dissolved oxygen (DO). The current method, being used to deoxygenate the end-shield cooling water, is a chemical treatment by addition of reducing agent, hydrazine, to react with DO. This method has several limitations including high reaction temperature of hydrazine , unwanted explosive hydrogen gas production, and its intrinsic harmful property. A new approach to remove DO using a membrane-based oxygen removal system (MORS) was tried to overcome limitations of the hydrazine treatment. The DO removal efficiency of the MORS was found to be in the range 87% to 98%: The higher vacuum, the lower water flow rate and the higher water temperature tend to increase the DO removal efficiency.

• BMB Reports
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• v.32 no.1
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• pp.25-27
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• 1999

Otitis media with effusion (OME) is an inflammatory disease of the middle ear cleft. Oxygen free radicals have been implicated in a variety of inflammatory disorders. Oxygen free radicals may also be involved in the pathogenesis of OME. To evaluate the involvement of oxygen free radicals in the pathogenesis of OME, the level of malondialdehyde, which gives an index of lipid peroxidation by oxygen free radicals, was measured by the reaction with thiobarbituric acid. Malondialdehyde level in the middle ear fluid from the OME group was higher than that in the normal control group. Malondialdehyde level in the middle ear fluid from a mucoid subgroup was higher than that in the serous subgroup. Malondialdehyde levels in the middle ear fluid from the serous subgroup was significantly correlated with symptom duration. The Pearson correlation coefficient between malondialdehyde levels in the middle ear fluid from the serous subgroup and symptom duration was 0.842 (P<0.05). These results indicate that lipid peroxidation by oxygen free radicals may be involved in the pathogenesis of human OME.