• Bulletin of the Korean Chemical Society
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• 제32권6호
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• pp.2027-2031
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• 2011

Molecular dynamics simulation is used to study the binary collisions of nanometer-sized droplets of argon in the presence of a surrounding gas. By systematically varying the droplet size, the impact parameter and the velocity of collision, the outcome of such collisions were examined and they can be classified into coalescence, separation and shattering. If one of the colliding droplets is half or less than the other in diameter, a shattering is not possible to occur. The threshold of impact parameter for a given separation was studied by adjusting the Weber number. Overall nanoscale droplets were more likely to coalesce than the macroscopic sized ones due to their high surface-to-volume ratio.

• 한국기계가공학회지
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• 제11권5호
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• pp.109-114
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• 2012

The combustion characteristics using forced pulsating flow were experimentally investigated with confined premixed flames stabilized by a reward-facing step. The intermittent combustion has many merits, for instance, such as high load combustion, high heat transfer, low emission gas, compared with those of continuous combustion. For these purposes, data processing of binary image was conducted to reveal the differences between intermittent and continuous combustion. As the results, it was possible to calculate the reaction zone using OH-emission band and, therefore, showed that forced pulsating flow was useful in combustion technology.

• International Journal of Air-Conditioning and Refrigeration
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• 제11권2호
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• pp.61-66
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• 2003

In order to prevent roll-over and a rapid boil-off of LNG in tanks, the phase equilibria of carbon dioxide in liquefied natural gas components as binary mixtures at cryogenic temperatures have been experimentally measured using Fourier transform infrared spectroscopy in conjunction with a specially designed variable pressure/temperature cryostat cell (pathlength 2 mm; pressures up to 30 bar). Solid carbon dioxide has been found to be comparatively soluble in liquid nitrogen (3.25$\times$${10}^{-6}$ mole fraction), liquid methane (1.04$\times$${10}^{-4}$ mole fraction), liquid ethane (3.1$\times$${10}^{-2}$ mole fraction) and liquid propane (6.11$\times$${10}^{-2}$ mole fraction) at their normal boiling temperatures. The solubilities of carbon dioxide in various cryogens, which increased with increasing temperature, are much lower than those obtained by others using gas chromatography. The differences are attributed to infrared spectroscopy selectively measuring dissolved solute in situ whereas gas chromatography measures microscopic particulate solid in addition to dissolved solute.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.II
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• pp.1218-1220
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• 2005

We have developed laser absorption spectroscopy system for the measurement of excited Xe atoms in micro-discharged AC-PDP plasma. In this study, we have measured the absorption signals for the $1S_5$ xenon metastable state in the PDP cell with the various gas mixtures of Ne-Xe(1%), Ne-Xe(4%) and Ne-Xe(10%) under fixed gas pressure of 350 Torr and the eletrode gap distance of 50um. It is found that the maximum excited xenon densities are $1.2^{\ast}10^{12}\;cm^{-3}$, $1.8^{\ast}10^{12}\;cm^{-3}$ and $2.7^{\ast}10^{12}cm^{-3}$ for gas mixtures of Ne-Xe(1%), Ne-Xe(4%) and Ne-Xe(10%) respectively, in this experiment.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.1334-1335
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• 2008

Although many studies have been carried out about binary gas mixtures with $SF_6$, few studies were presented about breakdown characteristics of $SF_6/CF_4$ mixtures. At present study the breakdown characteristics of $SF_6/CF_4$ mixtures in uniform and nonuniform field was performed. The experiments were carried out under AC voltages. The sphere-sphere electrode whose gap distance was 1 mm was used and the point-plane electrode whose gap distance was 3 mm was used in a test chamber. $SF_6/CF_4$ mixture contained 20% $SF_6$ and 80% $CF_4$ and the experimental gas pressure ranged from 0.1 to 0.5 MPa. The results show that addition of $SF_6/CF_4$ mixtures increase AC breakdown voltages. In uniform field the breakdown voltages of gas were linearly increased according to the pressure. However in nonuniform field the breakdown voltages of gas were increased nonlinearly.

• 한국식품과학회지
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• 제26권3호
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• pp.195-198
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• 1994

Yeast 발효공정에서 발생되는 가스량을 전자적으로 monitoring 할 수 있는 새로운 기포수 계측 쎈서를 설계, 제작하였다. 본 기포쎈서는 기체를 발생하는 발효공정에 적용할 수 있으며 공정의 상태와 환경에 아무런 변화를 주지 않도록 설계하였다. 그 구조는 가스포집부, 기포형성부, 전자식 기포감지부와 컴퓨터 접속장치로 구성하였다. 기포 계측부는 photo-interrupter카 counter IC 등을 사용하였다. 제작된 쎈서와 컴퓨터 시스템은 효모 배양공정에 활용하여 발효진행과정을 자동적으로 monitoring 하는데 성공하였으며 발효공정에서 발생된 기포수의 값으로 작성된 가스발생량 곡선은 효모의 생육곡선의 양상과 매우 유사한 모양을 보였으며 배양액의 기질영양원이 달리한 발효공정을 monitering한 결과 기질이용 특성도 정확하게 표현할 수 있었다.

• 공업화학
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• 제5권4호
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• pp.706-713
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• 1994

$45^{\circ}C$와 $65^{\circ}C$의 등온하에서 MTBE-methanol, MTBE-n-heptane, methanol-n-heptane 각 이성분계에 대한 등온 기액 평형 데이타를 head space gas chromatography(H.S.G.C.)를 이용해서 측정하였다. 이들중에 MTBE-methanol계와 methanol-n-heptane계에서 최소공비점이 발견되었으며, 특히 methanol-n-heptane계에서는 불용영역의 존재로 인한 불균일 최소공비점을 나타내었다. 각각의 실험 데이타들은 과잉 Gibbs 에너지 모델에 합치시켜서 그 상관관계를 알아보았으며, Redlich-Kister의 적분법에 의한 열역학적 일치성 시험도 수행하였다.

• 연구논문집
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• 통권23호
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• pp.57-62
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• 1993

An experimental investigation was carried out to study the characteristics of concentration of a coaxial jet being tone excited and consisting of $CO_2$, and air. The concentration in a binary gas mixture was measured by using the hot-wire anemometer and flow visualization was performed by the schlieren technique. In the case of excited flow, it is found that acoustic energy is partially transferred to RMS concentration to enhance mixing.

• 한국경영과학회지
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• 제17권3호
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• pp.1-12
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• 1992

Parallel Genetic Algorithms (GAs) are developed to solve a single machine n-job scheduling problem which is to minimize the sum of absolute deviations of completion times from a common due date. (0, 1) binary scheme is employed to represent the n-job schedule. Two selection methods, best individual selection and simple selection are examined. The effect of crossover operator, due date adjustment mutation and due date adjustment reordering are discussed. The performance of the parallel genetic algorithm is illustrated with some example problems.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.II
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• pp.1221-1224
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• 2005

The improvement of luminance and luminous efficiency is the one of the most important parts in AC-PDPs. To achieve high luminance and luminous efficiency, high VUV emission efficiency is needed. We measured the emission spectra of the vacuum ultraviolet(VUV) rays in surface discharge AC-PDP with ternary gas mixture of He-Ne-Xe. The influence of He-Ne-Xe gas-mixture ratio on excited $Xe^{\ast}$ resonant atoms and $Xe_2\;^{\ast}$ dimers has been investigated. It is found that luminous efficiency of ternary gas mixture, He-Ne-Xe, is shown to be much higher than that of binary gas mixture of Ne-Xe. For improving discharge luminous efficiency, we have studied VUV emission characteristics of ternary gas mixture, He(50%)-Ne-Xe and He(70%)-Ne-Xe with Xe concentration and filling gas pressure.