• 천문학회지
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• 제37권2호
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• pp.61-77
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• 2004

We have searched for HI 21 cm line emission from shocked atomic gas associated with southern supernova remnants (SNRs) using data from the Southern Galactic Plane Survey. Among the 97 sources studied, we have detected 10 SNRs with high-velocity HI emission confined to the SNR. The large velocity and the spatial confinement suggest that the emission is likely from the gas accelerated by the SN blast wave. We also detected 22 SNRs which show HI emission significantly brighter than the surrounding regions over a wide ($>10 km\;s^{-1}$) velocity interval. The association with these SNRs is less certain. We present the parameters and maps of the excess emission in these SNRs. We discuss in some detail the ten individual SNRs with associated high-velocity HI emission.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2014년도 제49회 KOSCO SYMPOSIUM 초록집
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• pp.237-238
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• 2014

A correlation between an air inflow velocity and $NO_x$ emission is investigated numerically. The area of a swirl premixed burner is controlled geometrically to increase or decrease an air inflow velocity. When an air velocity increases, mixedness at the burner exit is improved and NO emission at the liner exit is reduced. Although the area of an air slit is the same, NO emission shows discrepancy due to difference of air slit shapes.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2006년도 제32회 KOSCO SYMPOSIUM 논문집
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• pp.63-68
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• 2006

Effects of oxidizer inlet velocity on NO emission characteristics of 0.2MW oxy-fuel combustor have been experimentally investigated. The NO formation process in the oxy-fuel combustion is extremely sensitive even for the small fraction of nitrogen in oxidizer. By increasing the oxidizer velocity, flame length is reduced due to the enhanced turbulent mixing. The increased oxidizer velocity also results in the decreased flame temperature through the elevated entrainment rate of the recirculated product and the corresponding NO emission is drastically decreased. Experimental results clearly indicate that the entrained product gases play a crucial role to decrease the temperature at the flame zone and the post flame zone where the thermal NO is mainly formed.

• 천문학회보
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• 제37권1호
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• pp.33.2-33.2
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• 2012

Low-ionization nuclear emission-line region (LINER) galaxies constitute a major fraction of low-luminosity AGN population in the local Universe. In contrast to Seyfert galaxies, it is theoretically expected that LINERs would not have an outflow due to their low Eddington ratio. Using Keck/LRIS spectroscopy on a nearby LINER galaxy SDSS J091628.05+420818.7, we find a significant radial velocity offset for [OIII]${\lambda}$5007 emission line as - 50 km $s^{-1}$ blueshifted compared to systemic velocity of the galaxy, while other emission lines exhibit no or little offset. The observed [OIII] velocity offset possibly indicates an outflow of gas in the LINER galaxy, and it is probable that we only detected the [OIII] velocity offset because [OIII] ionization region is closer to the accretion disk, hence, more affected by an outflow. We further investigate the [OIII] velocity offset of -4000 SDSS AGN-host galaxies to compare the strength of AGN outflow. We find that a number of both LINER and Seyfert galaxies show [OIII] velocity offset, but the fraction of LINER galaxies with velocity offset is smaller than that of Seyfert galaxies. The preliminary results imply the presence of gas outflow in LINER galaxies, although outflow strength is probably weaker compared to Seyfert galaxies.

• 천문학회보
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• 제39권1호
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• pp.43.2-43.2
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• 2014

We investigate the ionized gas kinematics at the center of 6 nearby Seyfert galaxies, using the integral field spectroscopy data from the Calar Alto Legacy Integral Field spectroscopy Area survey Data Release 1. To understand the kinematic nature of the ionized gas in the narrow-line regions (NLRs), we measured the flux, velocity, and velocity dispersion of the [OIII] $5007{\AA}$ and Ha $6563{\AA}$ emission lines, after subtracting a best-fit stellar population model representing the stellar features. At the same time, we measured stellar velocity as a reference for the systemic velocity, and stellar velocity dispersion. We spatially resolved the velocity structure of the ionized gas using each emission line and compared it to that of stars. In this poster we present the flux, velocity, and velocity dispersion maps of the ionized gas and stars, and discuss the nature of the ionized gas outflows in the central kiloparsec scale.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 추계학술대회논문집B
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• pp.102-105
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• 2001

Numerical simulations of coal combustion were carried out to identify what kind of burner design parameters are affecting the NOx emission. Where used burner design parameters are primary air velocity, secondary air velocity, $2^{nd}/3^{rd}$ air ratio, tertiary air velocity, and tertiary air injection location. Taguchi method was used to find the effective burner design parameters related to NOx formation. The results of numerical simulations showed that secondary air velocity and $2^{nd}/3^{rd}$ air ratio was the key parameters reducing the NOx emission. The total number of simulation cases was reduced by Taguchi method.

• 한국수소및신에너지학회논문집
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• 제25권1호
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• pp.47-58
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• 2014

The characteristics of flame shape, laminar burning velocity, emissions and heat flux of stagnation point in premixed impinging jet flame of syngas fuel with 10% hydrogen content were experimentally investigated. Also, the adiabatic temperature and burning velocity are calculated by Chemkin package with USC-II mechanism. The equivalence ratios(0.8~5.0) and dimensionless separation distance(2.0~5.0) with fixed Reynolds number(1800) are main parameters in this work. Different flame shapes and colors were observed for different impingement conditions. The experimental results of burning velocity by flame surface area have a consistent with previous works and numerical simulation of this work. The inner flame length could be predicted with the ratio of mixture velocity and burning velocity from a simple formulation by the laminar burning velocity definition. It has been observed that the heat fluxes at stagnation point are directly affected by the flame shape including the separation distance. The emission results in impinging flame of syngas fuel show that the characteristics of $NO_x$ emission traced well with adiabatic temperature trend and CO emission due to fuel rich condition increased continuously with respect to the equivalence ratio.

• 한국터널지하공간학회 논문집
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• 제2권2호
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• pp.22-31
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• 2000

철도터널에서 오염물질의 거동은 열차의 운행조건 및 터널의 구조 등과 같은 다양한 인자에 의해 영향을 받아 매우 복잡한 양상을 보이게 된다. 본 연구에서는 SES프로그램을 수정하여 해석한 농도계산을 이용하여 철도터널에서 오염물질의 거동특성을 구명하고, 터널의 단면적, 길이 및 열차의 항력계수, 주행속도가 터널의 최대풍속 및 오염농도에 미치는 영향에 대한 분석결과를 제시하였다.

• 한국연소학회지
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• 제10권1호
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• pp.1-6
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• 2005

This paper presents the combustion characteristics of hydrocarbon fuel from a conventional pressure-swirl nozzle of a small-scale burner. The nozzle has orifice diameters of 0.256 mm and liquid flow rates ranging from 50 to 64 mL/min were selected for the experiments. The furnace temperature distribution along the axial distance, the gas emission such as CO, $CO_2$, NOx, $SO_2$, flue gas temperature, and combustion efficiency were studied. The local furnace and flue gas temperatures decreased with an increase in air velocity. At injection pressures of 1.1 and 1.3 MPa the maximum furnace temperatures occurred closer to the burner exit, at an axial distance of 242 mm from the diffuser tip. The CO and $CO_2$concentrations decreased with an increase in air velocity, but they increased with an increase in injection pressure. The effect of air velocity on NOx was not clearly seen at low injection pressures, but at injection pressure of 1.3 MPa it decreased with an increase in air velocity. The effect of air velocity on $SO_2$ concentration level is not well understood. The combustion efficiency decreased with an increase in air velocity but it increased with an increase in injection pressure. It is recommended that injection pressure less than 0.9 MPa with air velocity not above 8.0 m/s would be suitable for this burner.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 2005년도 동계 학술대회 논문집
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• pp.76-82
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• 2005

This paper presents the combustion characteristics of hydrocarbon fuel from a conventional pressureswirl nozzle of a small-scale burner. The nozzle has orifice diameters of 0.256 mm and liquid flow rates raging from 50 to 64 mL/min were selected for the experiments. The furnace temperature distribution along the axial distance, the gas emission such as CO, $CO_2,\;NOx,\;S0_2,$ flue gas temperature, and combustion efficiency were studied. The local furnace and flue gas temperatures decreased with an increase in air velocity. At injection pressures of 1.1 and 1.3 MPa the maximum furnace temperatures occurred closer to the burner exit, at an axial distance of 242 mm from the diffuser tip. The CO and $CO_2$ concentrations decreased with an increase in air velocity, but they increased with an increase in injection pressure. The effect of air velocity on NOx was not clearly seen at low injection pressures, but at injection pressure of 1.3 MPa it decreased with an increase in air velocity. The effect of air velocity $SO_2$ concentration level is not well understood. The combustion efficiency decreased with an increase in air velocity but it increased with an increase in injection pressure. It is recommended that injection pressure less than 0.9 MPa with air velocity not above 8.0 m/s would be suitable for this burner.