• Journal of Mechanical Science and Technology
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• 제14권12호
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• pp.1365-1375
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• 2000

Two phase flows have been numerically calculated to analyze plume characteristics and liquid circulation in gas injection through a porous plug. The Eulerian approach has been for formulation of both the continuous and dispersed phases. The turbulence in the liquid phase has been modeled using the standard $textsc{k}$-$\varepsilon$ turbulence model. The interphase friction coefficient has been calculated using correlations available in the literature. The turbulent dispersion of the phase has been modeled by the "dispersion Prand시 number". The predicted mean flows is compared well with the experimental data. The plume region area and the axial velocities are increased with the gas flow rate and with the decrease in the inlet area. The turbulent intensity also shows the same trend. Also, the space-averaged turbulent kinetic energy for various gas flow rates and inlet areas has been obtained. The results are of interest in the design and operation of a wide variety of materials and chemical processing operations.

• 설비공학논문집
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• 제11권6호
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• pp.824-834
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• 1999

Characteristics of two-phase flow and heat transfer were numerically investigated in a submerged gas injection system when temperature of the injected gas was different from that of the liquid. The Eulerian approach was used for both the continuous and dispersed phases. The turbulence in the liquid phase was modeled using the standard $k-\varepsilon$$\varepsilon$ turbulence model. The interphase friction and heat transfer coefficient were calculated from the correlations available in the literature. The turbulent dispersion of the phases was modeled by a "dispersion Prandtl number". In the case with heat transfer where the temperature of the injected gas is higher than the mean liquid temperature, the axial and the radial velocities are lower in comparison with the case of homogeneous temperatures. The results in the present research are of interest in the design and operation of a wide variety of material and chemical processes.

• 상하수도학회지
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• 제12권4호
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• pp.33-42
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• 1998

The optimum design and preliminary cost estimations of air stripping towers ASTs with granular activated carbon adsorption (GAC) systems as the off-gas treatment were done and compared to liquid-phase GAC system. The optimum design and preliminary cost estimations were done for either single or multicomponent systems. A computer program was developed for this study. 15 single compounds and their multicomponent systems were studies. Even with off-gas treatment, AST was generally a less expensive process for treatment of volatile organics than liquid-phase GAC system. Treatment costs of small systems were sensitive to system capacity. Accumulative effect of treatment costs was found in multicomponent systems. The cost of a multicomponent system was highly dependent on the least strippable component in ASTs even with gas-phase GAC or the least adsorbable component in liquid-phase GAC system.

• 대한전자공학회논문지
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• 제23권6호
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• pp.820-832
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• 1986

In contrast to conventional liquid phase epitaxy of GaAs, surface kinetics limited growth is predominant in selective liquid phase epitaxy. For the stripe openings in the high-index crystal-lographic directions, the well-known facet formations and the decompositions into the low index planes or smooth circular surfaces are observed depending on the growth kinetics. For the low index direction stripe, surface kinetics limited growth is evident. By a numerical calcualtion we show that these phenomena are due to the enhanced masstransport by two dimensional diffusion and growth rate anisotropy which is found to be very stdrong with cusped minima for some singular planes in the solution growth as well as in vapor phase epitaxy. Morphological stability is briefly treated in terms of diffusion and its implications on device application are stated. Tese phenomena may be common to III-V compound semiconductors as well as GaAs.

• 한국자기공명학회논문지
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• 제15권1호
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• pp.14-24
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• 2011

We have performed Liquid Chromatography-Solid Phase Extraction-NMR (LC-SPE-NMR) analysis for liquid crystalline mixture and elucidated the structures of selected components by NMR spectra. Combining the results of one-dimensional 1H experiments as well as homonuclear and heteronuclear two-dimensional experiments, we could analyze the molecular structure of the liquid crystal singles whose structure had not been interpretable by mass spectrometry alone.

• 대한기계학회논문집B
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• 제25권11호
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• pp.1552-1560
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• 2001

This paper presents the experimental results of a study undertaken to develop an electrostatic spray system for a combustion application. The characteristics of the liquid atomization and the droplet dispersion in the electrostatic spray of twin fluids were investigated by the optical measurement techniques. The processes associated with the break-up of charged jets were also observed using the laser sheet visualization. The diameter and velocity of droplets were simultaneously measured using the phase Doppler measurement technique. The electrostatic atomization of the liquid fuel depended primarily on the charging voltage and the flow rate, but the dispersion of droplets depended significantly on the aerodynamic flow. Aerodynamic influences on the liquid atomization decreased with an increase of the charging voltage. Consequently, the liquid atomization and the droplet dispersion could be independently controlled using the electrostatic and aerodynamic mechanisms.

• 한국축산식품학회지
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• 제25권3호
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• pp.340-343
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• 2005

SLM을 이용한 short peptide의 분리를 목적으로 donor phase의 pH 및 acceptor phase의 염농도, membrane의 carrier 농도 차에 따른 peptide의 이동속도를 확인한 결과는 다음과 같다. 즉, pH 7.0 이하에서는 acceptor phase의 NaCl 농도나 carrier 농도에 상관없이 Gly-Tyr의 이동속도는 거의 영향을 끼치지 않았고, pH 7.0 이상에서는 이동속도가 급격히 증가함을 알 수 있었다. 그리고 Aliquat가 $8\%$ 함유된 D-SLM과 $20\%$ 함유된 H-SLM의 경우 Gly-Tyr의 이동속도는 H-SLM이 D-SLM보다 pH 9.0, 0.25 M NaCl 용액에서는 약 3배, pH 8.0, 1.0 M NaCl용액에서는 10배 정도 빠르게 이동하였다. 또한 H-SLM에서 acceptor phase의 NaCl 농도가 1.0 M 인 경우 0.25 M에 비해 10배 정도 이동속도가 빠른 것으로 나타났다. 따라서, short peptide인 Gly-Tyr의 SLM을 이용한 추출에서 donor phase의 pH 7.0 이상, carrier 농도가 높은 H-SLM 사용, acceptor phase의 염 농도가 높을수록 이동속도가 빠른 것으로 나타났다.

• Bulletin of the Korean Chemical Society
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• 제32권spc8호
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• pp.3149-3151
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• 2011

• Bulletin of the Korean Chemical Society
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• 제33권8호
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• pp.2806-2808
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• 2012

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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• pp.611-614
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• 2003

We have investigated electric field effect on the formation of phase separated composite organic film structure which is utilized by anisotropic phase separation from LC and prepolymer mixtures. Application of bias field resulted in a significant change in liquid crystal alignment between glass substrate and polymer layer. The liquid crystal molecules segregated into the inter-electrodes and formed twisted structure which is the result of imprinting of LC alignment by the bias field on polymer layers during polymerization process.