• Polymer Science and Technology
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• v.18 no.6
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• pp.549-553
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• 2007

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.340-343
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• 2008

This work reports the simple fabrication of the single cell gap transflective liquid crystal display (LCD) using wire grid polarizer. The nano sized wire grid polarizer was patterned on common electrode itself, on the reflective part of FFS (Fringe field switching) mode whereas the common electrode was unpatterned at transmissive part. However, this structure didn't show single gamma curve, so we further improved the device by patterning the common electrode at transmissive part. As a result, V-T curve of proposed structure shows single gamma curve. Such a device structure is free from in-cell retarder, compensation film and reflector and furthermore it is very thin and easy to fabricate.

• Proceedings of the Korean Vacuum Society Conference
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• 2009.08a
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• pp.224-224
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• 2009

• 한국초전도학회:학술대회논문집
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• 2007.07a
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• pp.81-81
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• 2007

• Polymer(Korea)
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• v.38 no.4
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• pp.434-440
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• 2014

We prepared nanoparticles containing insoluble celecoxib by the method of solid dispersions using a spray dryer to improve solubility of celecoxib. We used PVP K30 and Eudragit EPO as water-soluble carriers for the solid dispersion, and poloxamer 407 as a surfactant. Characterization of celecoxib solid dispersion was performed by scanning electron microscope (SEM), differential scanning calorimetry (DSC), X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR). The results of SEM, DSC and XRD demonstrated that celecoxib is amorphous in solid dispersion. The dissolution rate measured in intestinal juice showed that the method of solid dispersion improved celecoxib solubility as compared with a conventional drug (Celebres$^{(R)}$). In conclusion, solid dispersion formulation prepared by a spray dryer would improve the solubility of celecoxib in oral administration.

• Polymer(Korea)
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• v.35 no.5
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• pp.378-384
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• 2011

Silk fibroin is a biocompatible and slowly biodegradable natural polymer. This natural polymer has excellent mechanical properties, non-toxicity, and non-immunogenic properties and has been demonstrated to support tissue regeneration. Also, gelatin is a natural material derived from collagen by hydrolysis and has an almost identical composition as that of collagen. Silk fibroin/gelatin scaffolds have been fabricated by using the freeze-drying method. To establish the scaffold manufacturing condition for silk fibroin and gelatin, we made scaffolds with various compositions of gelatin, glutaldehyde and silk fibroin. The silk fibroin/gelatin scaffolds were characterized using SEM, DSC, and water absorption ability tests. The cellular proliferation was evaluated by WST assay. These results suggested that a scaffold containing 8% of gelatin, 1% of glutaldehyde and 0.3 g of silk fibroin provided suitable characterstics for cell adhesion and proliferation. In conclusion, the silk fibroin/gelatin scaffold may serve as a potential cell delivery vehicle and a structural basis for tissue engineering.

• Polymer(Korea)
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• v.37 no.6
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• pp.702-710
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• 2013

Zaltoprofen loaded polyoxalate (POX) microspheres were prepared by an emulsion solvent-evaporation/extraction method like oil-in-water (O/W) for sustained release of zaltoprofen. The influence of several preparation parameters such as fabrication temperature, stirring speed, intensity of the sonication, initial drug ratio, molecular weight ($M_w$) of POX, concentration of POX and concentration of emulsifier has been investigated on the zaltoprofen release profiles. Physicochemical properties and morphology of zaltoprofen loaded POX microspheres were investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), differential scanning calorimeter (DSC) and Fourier transform infrared (FTIR). Through the analyzed results, it was demonstrated that the characteristics of the microspheres greatly affected by the prepared condition. The releases behavior of zaltoprofen was investigated for 10 days in vitro. It was confirmed that the release behavior of zaltoprofen can be controlled by the manufacturing factor of solvent-evaporation/extraction method.

• Nuclear Engineering and Technology
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• v.41 no.4
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• pp.455-476
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• 2009

The history of nuclear fusion research in Korea is rather short compared to that of advanced countries. However, since the mid-1990s, at which time the construction of KSTAR was about to commence, fusion research in Korea has been actively carried out in a wide range of areas, from basic plasma physics to fusion reactor design. The flourishing of fusion research partly owes to the fact that industrial technologies in Korea including those related to the nuclear field have been fully matured, with their quality being highly ranked in the world. Successive pivotal programs such as KSTAR and ITER have provided diverse opportunities to address new scientific and technological problems in fusion as well as to draw young researchers into related fields. The frame of the Korean nuclear fusion program is now changing from a small laboratory scale to a large national agenda. Coordinated strategies from different views and a holistic approach are necessary in order to achieve optimal efficiency and effectiveness. Upon this background, the present paper reflects upon the road taken to arrive at this point and looks ahead at the coming future in nuclear fusion research activities in Korea.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.159-159
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• 2010

We conducted bum-in test by current stress to evaluate acceleration reliability characteristics about p-resistivity influence of GaN-based light-emitting diodes. The LEDs used in this study are the polarization field-induced LED(PF-LED) having low p-resistivity and the highly resistive LED(HR-LED) having high p-resistivity. The result of high stress experiment shows that current crowding phenomenon is occurred from the center of between p-bonding pad and n-bonding pad to either electrodes. In addition, series resistance and optical power decrease dramatically. These results means that the resistance of between p-bonding pad and p-GaN affect reliability. That's why we need to consider the ohmic contact of p-bonding pad when design the high efficiency and high reliability LEDs.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.160-160
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• 2010

In this work, we investigate ohmic contacts to p-type GaN using a Pt/Cu/Au metallization scheme in order to achieve low resistance and thermally stable ohmic contact on p-GaN. An ohmic contact formed by a metal electrode deposited on a highly doped InGaN/GaN superlattice sturucture on p-GaN layer. The specific contact resistance is $1.56{\times}10^{-6}{\Omega}cm^2$ for the as-deposited sample, $1.35{\times}10^{-4}{\Omega}cm^2$ for the sample annealed at $250^{\circ}C$ and $6.88{\times}10^{-3}{\Omega}cm^2$ for the sample annealed at $300^{\circ}C$.