• The Transactions of the Korean Institute of Power Electronics
• /
• v.6 no.5
• /
• pp.377-385
• /
• 2001

The mixed gas of Hydrogen and Oxygen is gained from water electrolysis reaction. It has constant volume ratio 2 : 1 Hydrogen and Oxygen, and it is used as a source of thermal energy by combustion reaction. This gas has better characteristics in the field of economy, efficiency of energy, and environmental intimacy than acetylene gas and LPG used for gas welding machine. So several studies of this gas are actively in progress nowadays. The object of this study is the optimization of power condition in the side of electricity for the Hydrogen-Oxygen gas generator, Firstly chemical analysis of electrolysis is conducted, and the relation of electrical energy and chemical energy is quantitatively investigated through Faraday's laws of electrolysis. After that, pulse power supply is designed for basic experiment which could be applied to the analysis of Hydrogen-Oxygen gas generator. In the basis of above steps, comparison and analysis of Hydrogen-Oxygen gas generator was conducted as variable frequency using pulse Power supply.

• Nuclear Engineering and Technology
• /
• v.53 no.7
• /
• pp.2221-2228
• /
• 2021

One-dimensional oxygen transport relation is indispensable to study the oxygen distribution in the LBE-cooled system with an oxygen control device. In this paper, a numerical research is carried out to study the oxygen transport characteristics in a gas-phase oxygen control device, including the static case and dynamic case. The model of static oxygen control is based on the two-phase VOF model and the results agree well with the theoretical expectation. The model of dynamic oxygen control is simplified and the gas-liquid interface is treated as a free surface boundary with a constant oxygen concentration. The influences of the inlet and interface oxygen concentration, mass flow rate, temperature, and the inlet pipe location on the mass transfer characteristics are discussed. Based on the results, an oxygen mass transport relation considering the temperature dependence and velocity dependence separately is obtained. The relation can be used in a one-dimensional system analysis code to predict the oxygen provided by the oxygen control device, which is an important part of the integral oxygen mass transfer models.

• Proceedings of the KSME Conference
• /
• 2001.06d
• /
• pp.115-120
• /
• 2001

The present study examined the possibility of $NO_{x}$ reduction in the high temperature industrial furnaces. duct burner of gas turbine cogeneration and two-stage gas turbine combustor. The experimental study was carried out for the diffusion flame of second stage combustor with the variations of oxygen concentration and supplying rate of hot exhaust gas from first stage combustor. It also examined the flammability range and $NO_{x}$ formation of the second stage combustor in which the fuel is supplying into the mixture of oxygen hot exhaust gas from first stage combustor. The results show that the enrichment of oxygen and increase of exhaust gas lead to increase the $NO_{x}$ up to 50 ppm with 23% $O_{2}$ condition.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2001.07a
• /
• pp.355-357
• /
• 2001

ZnO thin films were deposited on (001) sapphire substrate at various ambient gas pressure by pulsed laser deposition(PLD). Oxygen was used as ambient gas, and oxygen gas pressure was varied from 1.0${\times}$10$\^$-6/ Torr to 500 mTorr during the film deposition. As oxygen gas pressure increase in the region below critical pressure photoluminescence(PL) intensity in UV and green region increase. As oxygen gas pressure increase in the region above critical pressure photoluminescence(PL) intensity in UV and green region decrease. Each of critical ambient gas Pressures was 350 mTorr for UV emission and 200 mTorr for green emission.

• Bulletin of the Korean Chemical Society
• /
• v.23 no.3
• /
• pp.369-373
• /
• 2002

The liquid phase oxidation of p-xylene has been carried out with oxygen-enriched gas, and the manganese component was precipitated probably via over-oxidation to $Mn^{4+}$. The precipitation increased with rising oxygen concentration in the reaction gas and occurred mainly in the later part of the oxidation. The activity of the reaction decreased, and the blackening of the product and side reactions to carbon dioxide increased with the degree of precipitation. Precipitation can be decreased with the addition of metal ions, such as cerium, chromium and iron.

• Journal of Electrical Engineering and Technology
• /
• v.12 no.2
• /
• pp.852-857
• /
• 2017

In this paper, measurements of ion mobility were performed in oxygen at gas pressures of 44.52 - 101.19 kPa using the drift tube method. Over this pressure range, mobility values were within the limits of 1.796 to $3.821cm^2{\cdot}V^{-1}{\cdot}s^{-1}$ were determined and ion mobility shown to decrease non-linearly with increasing gas pressure towards a certain level of saturation. Ion mobility measured in air was lower than that measured in oxygen at the same gas pressure. Finally, a parameter correction method for calibrating the relationship between the ion mobility and gas pressure in oxygen was proposed.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2003.07a
• /
• pp.690-693
• /
• 2003

An Si substrate (100) was oxidized at $400^{\circ}C$ in inductively coupled oxygen plasma. Interstitial oxygen was found in the Si substrate at the initial stage of oxidation by IR measurements. An x-ray rocking curve of Si substrates showed a lower peak intensity due to lattice distortion by the interstitial oxygen. The refractive index of thin oxides, below which interstitial oxygen existed in the Si substrate, was smaller than the refractive index of thick oxides, below which no interstitial oxygen existed. The interstitial oxygen was found by plasma oxidation using $O_{2}$ gas and $N_{2}O$ gas. The inductively coupled plasma oxidation using $N_{2}O$ gas was performed by atomic oxygen, not by molecular oxygen, indicating that atomic oxygen in plasma is responsible for the incorporation of interstitial oxygen.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2010.08a
• /
• pp.88-88
• /
• 2010

We synthesized molybdenum thin films deposited by RF magnetron sputtering and physicochemical analysis was performed. The physical and chemical properties of these films were examined with X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The obtained film at the oxygen ratio of 0% showed crystallinity of cubic Mo(110) phase. After the oxygen ratio increased more than 5% in the sputter gas, the molybdenum films were formed as an amorphous phase. The thickness of the Mo thin film was drastically decreased from 1000 nm to ca 70 nm after introduction of oxygen in the sputter gas confirmed by spectroscopic ellipsometer (SE) and scanning electron spectroscopy (SEM). The calculated band gap of the film deduced from SE data increased from 3.17 to 3.63 eV by addition of oxygen in the sputter gas. The roughness of the Mo film was examined with atomic force microscopy (AFM) and it was dramatically decreased by introducing of oxygen during sputtering. XPS results revealed that the ratio of metallic Mo species in the film decreased by the contents of Mo(VI) species increased at the ratio of oxygen increased in the sputter gas and fully oxidized at low content of oxygen in the sputter gas.

• Journal of Photoscience
• /
• v.9 no.2
• /
• pp.409-411
• /
• 2002

In order to prevent side reactions due to free radical formation occurring in the reactions of singlet oxygen generated in solution phse, it was required that singlet oxygen is generated in gas phase from an apparatus of a solid-gas system. We have accomplished to construct an apparatus generating singlet oxygen in solid-gas system, which is composed of a flexible optical fibre tube connected by a dye-sensitizer probe containing rose bengal dye on polymer or inorganic material. Through the optical fibre tube visible light from a laser and an oxygen stream are passed into the sensitizer probe where singlet oxygen is generated. The determination of singlet oxygen was carried out by two methods. One involves the detection of the luminescence of singlet oxygen at 1268 mn and the other involves the chemiluminescence reaction of a dihydroisobenzofuran with singlet oxygen emitting luminescence at 456 nm.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.14 no.12
• /
• pp.1008-1015
• /
• 2001

Thin films of vanadium oxide(VO$\_$x/) have been deposited by r.f. magnetron sputtering from V$_2$O$\_$5/ target in gas mixture of argon and oxygen. The oxygen/(oxygen+argon) partial pressure ratio is changed from 0% to 8%. Crystal structure, chemical composition, bonding, optical and electrical properties of films sputter-deposited under different oxygen gas pressures are characterized through XPS, AES, RBS, FTIR, optical absorption and electrical conductivity measurements. V$_2$O$\_$5/ and lower oxides co-exist in sputter-deposited films and as the oxygen partial pressure is increased the films become more stoichiometric V$_2$O$\_$5/. The increase of O/V ratio with increasing oxygen gas pressure is attributed to the partial filling of oxygen vacancies through diffusion. It is observed that the oxygen atoms located on the V-O plane of V$_2$O$\_$5/ layer participate more readily in the oxidation process. With increasing oxygen gas pressure indirect and direct optical band gaps are increased, but thermal activation energies are decreased.