• 설비공학논문집
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• 제7권4호
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• pp.556-565
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• 1995

The physical model of interest is based upon the concentric cylinder, where the outside cylinder is filled with optically thick and high temperature phase change material(PCM). The fluid is flowing through the inside cylinder to transfer the appropriate energy. The fluid is flowing through the inside cylinder to transfer the appropriate energy. The governing equations for the phase change material including internal thermal radiation and for the turbulent transfer fluid have been employed and numerically solved. The optically thick phase change justifies the P-l spherical harmonics approximation, which is believed to be appropriate choice particularly for the much coupled problem like in this study. The solid/liquid interface, temperature distribution within the PCM and the heat flux from the PCM to the transfer fluid have been obtained and compared with those of laminar transfer fluid. The numerical results show that the turbulent transfer fluid accelerates the solid/liquid interface and results in the increase of heat transfer rate from the PCM. The internal thermal radiation within the PCM, however, does not always playa role to increase the heat transfer rate throughout the inside cylinder. It is believed that the combined heat flux has been picked up more in the inflowing area than in the pure conductive phase change material.

• 농업생명과학연구
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• 제46권6호
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• pp.165-171
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• 2012

As a preceding study for investigating the influence of sound wave stimulus on Arabidopsis thaliana metabolomics, the polar secondary metabolomes of the plant were determined using high performance liquid chromatography coupled with tandem mass spectrometry. A total of 10 polar secondary metabolomes were characterized and quantified. Among them, 4 metabolomes, p-coumaroylagmatine isomer (7 and 8), p-coumaroylagmatine isomer (9 and 10) were identified in the plant for the first time. The validation was conducted in terms of linearity, recovery, precision, limit of detection (LOD) and limit of quantification (LOQ). The validated method was applied to the simultaneous quantification of the 10 polar secondary metabolomes.

• Macromolecular Research
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• 제12권6호
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• pp.564-572
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• 2004

Modem applications could benefit from multifunctional materials having anisotropic optical, electrical, thermal, or mechanical properties, especially when coupled with locally controlled distribution of the directional response. Such materials are difficult to engineer by conventional methods, but the electric field-aided technology presented herein is able to locally tailor electroactive composites. Applying an electric field to a polymer in its liquid state allows the orientation of chain- or fiber-like inclusions or phases from what was originally an isotropic material. Such composites can be formed from liquid solutions, melts, or mixtures of pre-polymers and cross-linking agents. Upon curing, a 'created composite' results; it consists of these 'pseudofibers' embedded in a matrix. One can also create oriented composites from embedded spheres, flakes, or fiber-like shapes in a liquid plastic. Orientation of the externally applied electric field defines the orientation of the field-aided self-assembled composites. The strength and duration of exposure of the electric field control the degree of anisotropy created. Results of electromechanical testing of these modified materials, which are relevant to sensing and actuation applications, are presented. The materials' micro/nanostructures were analyzed using microscopy and X-ray diffraction techniques.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2004년도 춘계 학술대회논문집
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• pp.190-195
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• 2004

The pressure drop in a Venturi Scrubber is predicted using the Eulerian-Lagrangian Method, which is one of the numerical methods to solve the dispersed two-phase flow. KIVA-3V Code is modified to solve the coupled gas-liquid two-phase flow field. The liquid is assumed to be injected through the nozzles with the Rosin-Rammler drop size distribution. The computational results shows good agreement with the experimental data.

• Journal of Applied Biological Chemistry
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• 제56권3호
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• pp.137-139
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• 2013

강황(Curcuma longa)으로부터 bisdemethoxycurcumin (BDMC), demethoxycurcumin (DMC) 및 curcumin의 생물 활성을 offline-ABTS 측정법과 on-line screening high-performance liquid chromatography (HPLC)-ABTS 측정법을 적용한 빠른 스크리닝을 통해 정량 및 성분 분리를 하였다. 이때, off-line-ABTS와 on-line screening HPLC-ABTS 비교는 미미한 오차를 보여주었다.

• Journal of Applied Biological Chemistry
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• 제57권1호
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• pp.89-93
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• 2014

We aim to develop a simple method for simultaneous and quantitative determination of benzoic acid, caffeic acid and chlorogenic acid in seeds of Eriobotrya japonica. In addition, antibacterial effect of these three phenolic acids was examined. A basic method is performed on the high performance liquid chromatography system coupled to an UV-detector (230 nm) and reverse phase C-18 column ($4.6{\times}150mm$, $5{\mu}m$). Each phenolic acid was confirmed via liquid chromatography-mass spectrometry (MS)/MS system under the multiple-reaction monitoring with negative-ion electrospray ionization (ESI(-)) mode. It is demonstrated that the method was could be applied to samples for an analytical study of the phenolic acids. On the other hand, three phenolic acids in seeds of E. japonica exhibited antibacterial effect against several pathogenic bacteria. Of these, benzoic acid was found to have stronger antibacterial effect.

• 한국막학회:학술대회논문집
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• 한국막학회 1996년도 추계 총회 및 학술발표회
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• pp.12-17
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• 1996

The structure formation by liquid-liquid(L-L) phase separation coupled with crystallization in isotactic polypropylene(i-PP). solutioos was investigated by a temperature jump experiment. A series of dialkyl phthalates with a different number of carbon atoms in the alkyl chain was used to control the interaction between polymer and solvent. Various thermal quench conditions were applied to the i-PP solutions to control systematically L-L phase separation and crystallization. A slow crystallizatina elongates the liquid droplets in the radial direction of a spherulite. A rapid crystallization under the deep quench locks-in the growth of L-L phase separation. These results indicate that the extent of L-L phase separation which exists below melting point can be successfully controlled through the proper selection of solvent and thermal conditions.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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• pp.1121-1124
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• 2003

For high quality displays, analog responding liquid crystals with spontaneous polarization ($P_{s}$) need to be coupled with active matrix driving schemes. We have characterized the half-V-shaped switching ferroelectric liquid crystal mode (half-V FLC mode) in terms of dielectiric and voltage holding properties. Research on these switching properties provided us with the technology for switching half-V FLC mode FLCs by using amorphous silicon TFTs.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2003년도 The Fifth Asian Computational Fluid Dynamics Conference
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• pp.160-161
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• 2003

Thermocapillary convection is a surface tension driven flow due to a temperature gradient along an interface. It occurs during a crystal-growth process and therefore understanding the convection is important to material processing in microgravity. Although modelling of the float-zone crystal-growth process has been of interest for a few decades, most studies of liquid bridges assumed non-deformable flat surfaces. In reality, the surface profile, g(t,z), is unknown and should be obtained as a solution to the coupled transport equations along with the surface force balance. Here we report on a numerical study of axisymmetric thermocapillary convection in liquid bridges with deformable surfaces. The interface is determined as part of the complete solution. The influence of the capillary number (Ca), Reynolds number (Re), Prandtl number (Pr) and aspect ratio(Ar) on the dynamics is explored.

• 항공우주시스템공학회지
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• 제9권4호
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• pp.67-72
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• 2015

The analysis has been performed on the blockage effect at the propellant flow passage in a liquid rocket engine. This simulates an example of emergency situation where flow passage is partially blocked. The analysis method has been validated by predicting the pump head and flow rate within 1% precision against the measured data of turbopump-gas generator coupled test. When the oxidizer passage is reduced it is predicted that the mixture ratio decreases, the oxidizer pump head increases and the gas generator pressure increases. When the fuel passage is reduced it is predicted that the mixture ratio increases, fuel flow rate decreases and the fuel pump head increases.