• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.258-262
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• 2011

The laminar burning velocity in premixed Oxy-CH4 flames was studied in a lab-scale Bunsen burner. $CH^*$ chemiluminescence method and Schliren photography were used. Experimental results were compared with numerical prediction which was calculated with a CHEMKIN 3.7 package with a PREMIX code. Global equivalence ratio of oxy-CH4 mixture was varied from 0.5 to 2.0 in a laminar flow region. The laminar burning velocity was measured as 3.1 m/s for Schlieren photograph and 2.9 m/s for $CH^*$ chemiluminescence technique (angle method).

• Journal of Korean Society for Atmospheric Environment
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• v.33 no.5
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• pp.473-479
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• 2017

This study was designed to understand characteristics of oxy-combustion of coal, dried sewage sludge and solid refuse fuel (SRF). Thermogravimetric analysis was conducted by burning the fuels with air, 21% oxygen ($O_2$)/79% carbon dioxide ($CO_2$) and 30% $O_2/70%$ $CO_2$. Heating rates were varied as 5, 10, 25, 40 and $100^{\circ}C/min$. Complete coal combustion was found at the heating rates of 5, 10, 25 and $40^{\circ}C/min$, and different combustion behavior was found with the gas composition at the heating rates of 10, 25, 40 and $100^{\circ}C/min$. Coal combustion with 30% $O_2/70%$ $CO_2$ showed the highest while coal combustion with 21% $O_2/79%$ $CO_2$ showed the lowest combustion rate. On the other hand, the combustion of dried sewage sludge and SRF showed similar combustion behavior with respect to the combustion gas composition. This suggests that oxy-combustion of dried sewage sludge and SRF which contain a large amount of volatile matter may show similar combustion behavior to their air combustion.

• Journal of the Korean Society of Combustion
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• v.14 no.2
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• pp.1-9
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• 2009

New way to effectively capture $CO_2$ in coal fired power plant is the combustion of coal using oxy-fuel technology. Combustion characteristics of Minco sub-bituminous coal at oxy-fuel conditions using TGA and drop tube furnace (DTF) were included activation energy about the char burnout, volatile yield and combustion efficiency of raw coal, the porosity of pyrolyzed char and fusion temperature of by-product ash. TGA result shows that the effect of $CO_2$ on combustion kinetics reduces activation energy by approximately 7 kJ/mol at air oxygen level(21% $O_2$) and decreases the burning time by approximately 16%. The results from DTF indicated similar combustion efficiency under $O_2/CO_2$ and $O_2/N_2$ atmospheres for equivalent $O_2$ concentration whereas high combustion efficiency under $O_2/N_2$ than $O_2/CO_2$ was obtained for high temperature of more than $1,100^{\circ}C$. Overall coal burning rate under $O_2/CO_2$ is decreased due to the lower rate of oxygen diffusion into coal surface through the $CO_2$ rich boundary layer. By-product ash produced under $O_2/CO_2$ and $O_2/N_2$ was similar IDT in irrelevant to $O_2$ concentration and atmospheres gas during the coal combustion.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.10
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• pp.907-916
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• 2010

Integration of various bottoming cycles such as the gas turbine (GT) cycle, organic Rankine cycle, and oxy-fuel combustion cycle with an molten carbonate fuel cell (MCFC) power-generation system was analyzed, and the performance of the power-generation system in the three cases were compared. Parametric analysis of the three different integrated systems was carried out under conditions corresponding to the practical use and operation of MCFC, and the optimal design condition for each system was derived. The MCFC/oxy-combustion system exhibited the greatest power upgrade from the MCFC-only system, while the MCFC/GT system showed the greatest efficiency enhancement.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.119-120
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• 2007

반도체 공정에서 사용되는 ILD막질 중 oxy-nitrde(SiON) film은 contact etch stopper, photo공정을 위한 ARL(anti-reflection lay떠 그리고, 후속공정의 plasma damage에 대한 blocking layer로서의 역할을 담당하며 많은 공정에 널리 사용되고 있다. 그러나 막질 자체의 불완전성 (trap site, dangling bond)에 의해 cell current instability(CCI) 특성을 악화 시킬 수 있어 이에 대한 원인규명 및 대책이 요구되었다. 본 연구는 미국 S사(社) super flash memory에서 oxy-nitride 막질 증착 시의 gas flow량에 따른 CCI 특성변화를 연구하고 최적의 공정조건을 제시하고자 한다.

• Journal of Institute of Convergence Technology
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• v.4 no.1
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• pp.21-27
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• 2014

White LEDs (light-emitting diodes) are promising new-generation light sources which can replace conventional lamps due to their high reliability, low energy consumption and eco-friendly effects. This paper briefly reviews recent progress of oxy/nitride host phosphor and quantum dot materials with broad excitation band characteristics for phosphor-converted white LEDs. Among oxy/nitride host materials, $M_2Si_5N_8:Eu^{2+}$, $MAlSiN_3:Eu^{2+}$ M-SiON(M=Ca, Sr, Ba), ${\alpha}/{\beta}-SiAlON:Eu^{2+}$ are excellent phosphors for white LED using blue-emitting chip. They have very broad excitation bands in the range of 440-460 nm and exhibit emission from green to red. In this paper, In this review we focus on recent developments in the crystal structure, luminescence and applications of the oxy/nitride phosphors for white LEDs. In addition, the application prospects and current trends of research and development of quantum dot phosphors are also discussed.

• Journal of Hydrogen and New Energy
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• v.30 no.4
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• pp.320-329
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• 2019

This study was performed by the numerical approach to investigate chemical behaviors of homogeneous syngas ($CO/H_2$) with nitric monoxide (NO) in pressurized oxy-fuel conditions. Hydrogen had a dominant effect to the ignition delay time of syngas due to the fast chemistry of its oxidation. Combustion was promoted by NO at the low temperature region. It was by the additional heat release through NO oxidation and production and consumption of major radicals related to the ignition. Two stage ignition behavior was shown in the pressurized condition by the accumulation of $H_2O_2$ produced from $HO_2$ radical. Additional NO oxidation was induced by the pressurized oxy-fuel condition to produce $NO_2$.

• Korean Journal of Materials Research
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• v.33 no.7
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• pp.309-314
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• 2023

This study aimed to address the limitations of traditional plasma nitriding methods by implementing a short-term plasma oxy-nitriding treatment on the surface of AISI 420 martensitic stainless steel. This treatment involved the sequential formation of nitride and oxide layers, to enhance surface hardness and corrosion resistance, respectively. The process resulted in the formation of a 20 ㎛-thick nitride layer and a 3 ㎛-thick oxide layer on the steel surface. Initially, the hardness increased by 2.2 times after nitriding, followed by a subsequent decrease of approximately 31 % after oxidation. While the nitriding process reduced corrosion resistance, the subsequent oxidation process led to the formation of a passive oxide film, effectively resolving this issue. The pitting corrosion of the oxide passive film started at 82.6 mVssc, providing better corrosion resistance characteristics than the nitride layer. Consequently, the trade-off between surface hardness and corrosion resistance in plasma oxy-nitrided AISI 420 martensitic stainless steel is anticipated to be recognized as an innovative and comprehensive surface treatment process for biomedical components.

• Journal of Chest Surgery
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• v.57 no.3
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• pp.319-322
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• 2024

Venovenous extracorporeal membrane oxygenation (VV ECMO) is often used in cases of severe respiratory failure, especially in patients considered for lung transplantation. However, because many lung diseases can ultimately result in right heart failure, the treatment of secondary right heart failure can present a challenge when the patient is already under VV ECMO support. In such cases, an oxygenated-right ventricular assist device (OxyRVAD) can be used. OxyRVAD is designed to maintain anterograde blood flow and prevent right ventricular distension. Moreover, the pulmonary arterial cannula can be inserted percutaneously. We report a case in which percutaneous OxyRVAD was successfully implemented to manage right heart failure in a patient with respiratory failure who was on VV ECMO.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.40 no.9
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• pp.577-587
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• 2016

Although the formation of oxy-fuel MILD combustion is considered one of the promising combustion technologies for high thermal efficiency, low emissions and stability have been reported as difficulties. In this paper, the effect of combustor geometry and operating conditions on the formation of oxy-fuel MILD combustion was analyzed using numerical simulation. The results show that the high temperature region and average temperature decreased due to an increase in oxygen inlet velocity; moreover, a high degree of temperature uniformity was achieved using an optimized combination of fuels and an oxygen injection configuration without external oxygen preheating. In particular, the oxy-fuel MILD combustion flame was found to be very stable with a combustion flame region at equivalence ratio 0.90, fuel velocity 10 m/s, oxygen velocity 200 m/s, and nozzle distance 33.5 mm.