• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07a
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• pp.67-73
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• 2002

The development of high performance HTS wire is a key factor for various electrical applications of coils and cables. The purpose of this paper is to review and consider the main manufacturing technologies of HTS wire and its current status. A lot of efforts have been focused on the optimization of PIT parameters for Bi-2223/Ag wire. According to this, long Bi-2223 wires having Ic of 130 A were recently produced and their mass production has been underway in US. The current status performance of Bi-2223 wire is supposed to be used in power transmission cable because of its lower self-field property. Y-123 second generation conductor is extensively being developed throughout the world and many fabrication processes are competed with each other. 30 m-long Y-123 wire with Ic of 0.8 MA/$\textrm{cm}^2$ was recently fabricated using IBAD and PLD techniques in Japan. This result offers promise of scalable processing of practical multi-layer coated conductor.

• Toxicological Research
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• v.18 no.3
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• pp.227-232
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• 2002

In order to find out the appropriate in vitro method for high correlation with in vivo, we com-pared the sensitivities of phototoxicity (PT) in vitro method between in human keratinocytes, HaCaT cells and in 3T3 fibroblast cells derived from Balb/c mice. Both cells were exposed to six known phototoxic chemicals : promethazine, neutral red, chlortetracycline, amiodarone, bithionol, 8-methoxypsoralen, or non-phototoxic chemical, ALS (ammonium laureth sulfate) and then irradiated with 5 J/$cm^2$ of UVA. Cell viability ($IC_{50}$ ) was measured by neutral red uptake (NRU) assay. The ratio of $IC_{50}$ value of chemicals in the presence and absence of UVA was determined by the cut-off value. The phototoxic potential of test chemicals in NRU assay was determined by measuring the photoirriation factor (PIF) with a cut-off value of 5. In both 3T3 and HaCaT cells, all known phototoxic chemicals were positive (over 5 of PIF value), except that bithionol was found to be non-phototoxic to HaCaT cells, and ALS, non-phototoxic chemical was negative. These results suggest that Balb/c 3T3 cell was more sensitive than HaCaT cell to predict phototoxicity potential.

• Natural Product Sciences
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• v.2 no.1
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• pp.37-42
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• 1996

Several species and varieties of Allium spp. grown in Indonesia were screened for their in vitro antiplatelet aggregation activities. The extracts were also analyzed by GC for their volatile sulfur-containing compounds, and measured for their Volatile Reducing Substances (VRS) contents. Antiplatelet aggregation potencies of Allium spp. were varied among the species and varieties studied. Garlic extracts showed the greatest ability to inhibit platelet aggregation followed by extract of shallot, chive, yellow onion, and green onion. The 'Jawi' and 'local Padang' variety of garlic showed high activities with $IC_{50}$ values of 9.1 and $9.8\;{\mu}g/ml$, respectively. The local Kupang variety of shallot showed the highest antiplatelet activity among the shallot varieties evaluated, with an $IC_{50}$ value of $111\;{\mu}g/ml$. Antiplatelet aggregation activities of Allium extracts showed a positive correlation with the level of volatile compounds.

• International Journal of Automotive Technology
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• v.7 no.3
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• pp.289-294
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• 2006

Better fundamental understanding of the interactions between the in-cylinder flows and combustion process is an important requirement for further improvement in the fuel economy and emissions of internal combustion(IC) engines. Flow near a spark plug at the time of ignition plays an important role for early flame kernel development(EFKD). Velocity data measurements in this study were made with a two-component laser Doppler velocimetry(LDV) near a spark plug in a single cylinder optical spark ignition(SI) engine with a heart-shaped combustion chamber. LDV velocity data were collected on an individual cycle basis under wide-open motored conditions with an engine speed of 1,000rpm. This study examines and compares the flow fields as interpreted through ensemble, cyclic and discrete wavelet transformation(DWT) analysis. The energy distributions in the non-stationary engine flows are also investigated over crank angle phase and frequency through continuous wavelet transformation(CWT) for a position near a spark plug. Wavelet analysis is appropriate for analyzing the flow fields in engines because it gives information about the transient events in a time and frequency plane. The results of CWT analysis are provided and compared with the mean flows of DWT first decomposition level for all cycles at a position. Low frequency high energy found with CWT corresponds well with the peak locations of the mean velocity. The high frequency flows caused by the intake jet gradually decay as the piston approaches the bottom dead center(BDC).

• Journal of Mechanical Science and Technology
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• v.16 no.7
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• pp.902-910
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• 2002

Cast stainless steel may experience embrittlement when it is exposed approximately to 300$\^{C}$ for a long period. In the present investigation, the three classes of the thermally-aged CF8M specimen were prepared using an artificially-accelerated aging method. After the specimens were held for 300, 1800 and 3600hrs. at 430$\^{C}$, respectively, the specimens were quenched in water which is at room temperature. Load versus load line displacement curves and J-R curves were obtained using the unloading compliance method. talc values were obtained using the ASTM E813-87 and ASTM E 813-81 methods. In addition to these methods, talc values were obtained using the SZW (stretch zone width) method described in JSME S 001-1981. The results of the unloading compliance method are J$\_$Q/=543.9kJ/㎡ for virgin materials. The values of J$\_$IC/ for the degraded materials at 300, 1800 and 3600hrs. are obtained 369.25kJ/㎡, 311.02kJ/㎡, 276.7kJ/㎡, respectively. The results obtained by the SZW method are compared with those obtained by the unloading compliance method. Both results are quite similar. Through the elastic-plastic fracture toughness test, it is found that the value of loc is decreased with an increase of the aging time.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.241-244
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• 2003

The world largest 21.3" LTPS LCD has been successfully developed using SLS crystallization technology. Successful integration of gate circuit, transmission gate and level shifter was performed in a large area uniformly. Uniformity and high performance from high quality grains of SLS technology make it possible to come true a uniform large size LTPS TFT-LCD with half number of data driver IC's used in typical a-Si LCD. High aperture ratio of 65% was obtained using an organic inter insulating method, which lead a high brightness of 500cd/cm2.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07a
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• pp.104-106
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• 2003

다층의 산화물 박막으로 이루어진 coated conductor의 제조를 위하여 각층의 증착조건이 최적화되어야 한다. 가공/열처리를 통하여 2축배향성을 가지는 Ni 금속 기판위에 $Y_2O_3$, YSZ, $CeO_2$ 등의 산화물 완충층을 증착한 후 초전도층인 YBCO를 증착하였다. 12도와 8도의 in-plane fwhm (full width at half maximum)과 out-of-plane fwhm을 가지는 Ni 기판을 이용하여 13도와 4.5도의 in-plane 및 out-of-plane fwhm을 가지는 YBCO coated conductor를 제조하였다. 임계온도 (Tc), 임계전류 (Ic), 및 임계전류밀도 (Jc) 는 각각 84K, 3.3A, 및 $310,000\;A/cm^2$ 이었다.

• Journal of the Korean institute of surface engineering
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• v.36 no.1
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• pp.74-78
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• 2003

The corrosion failure of electronic devices has been a major reliability concern lately. This failure is an ongoing concern because of miniaturization of integrated circuits (IC) and the increased use of polymers in electronic packaging. Recently, plasma-polymerized cyclohexane films were considered as a possible candidate for a interlayer dielectric for multilever metallization of ultra large scale integrated (ULSI) semiconductor devices. In this paper the protective ability of above films as a function of deposition temperature and RF power in an 3.5 wt.% NaCl solution were examined by polarization measurement. The film was characterized by FTIR spectroscopy and contact angle measurement. The protective efficiency of the film increased with increasing deposition temperature and RF power, which induced the higher degree of cross-linking and hydrophobicity of the films.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.32 no.2 s.57
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• pp.75-79
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• 2006

In this study. we evaluated anti-aging activity of medical plants that protect the skin cell damage induced by UV irradiation. We have investigated diverse biological activities of Selaginella tamariscina as an anti-aging ingredient of cosmetics. S. tamariscina was found to show scavenging activities of radicals and reactive oxygen species (ROS) with the $IC_{50}$ values of $65.1{\mu}g/mL$ against 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and $40.9 {\mu}g/mL$ against superoxide radicals in the xanthine/xanthine oxidase system, respectively. For testing intracellular ROS scavenging activity, the cultured human dermal fibroblasts were analyzed by increase in dichlorofluorescein (DCF) fluorescence upon exposure to UVB $20 mJ/cm^2$ after treatment of S. tamariscina. UVA-induced MMP-1 protein and mRNA expression in human dermal fibroblasts were reduced in a dose-dependent manner by S. tamariscina. Moreover, S. tamariscina inhibited MMP-2 (gelatinase) activity in UVA-irradiated human dermal fibroblasts assayed by zymography and semi-quantitative RT-PCR. Taken together, these results suggest that S. tamariscina may act as an anti-aging agent by Increasing collagen and preventing the skin cell damage induced by UV irradiation, and imply that S. tamariscina nay be useful as a new ingredient for anti-aging cosmetics.

• Korean Journal of Pharmacognosy
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• v.35 no.4 s.139
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• pp.293-299
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• 2004

The current investigation was carried out to find out the anticancer activity of the methanol extract from Buplerum falcatum against cancered ICR mouse and cancer cell lines such as J774A.1 and L1210 cells. Extract of Buplerum falcatum displayed the considerable augmentation(134%) of the survival of ICR mouse bearing Sarcoma 180 cancer. In addition, the cytotoxic effects of methanol extract of Buplerum falcatum against J774A.1 cells and L1210 cells were found to show $IC_{50}$ values of $57.3\;{\mu}g/ml$ and $54.6\;{\mu}g/ml$, respectively. In contrast to such cytotoxicity against cancer cells, the extract exerted only meagre toxicity against normal lymphocytes. The increased generation of $O_2^-$ and the considerably increased activities of super-oxide dismutase(SOD) and glutathione peroxidase(GPx) of both J774A.1 cells and L1210 cells in the presence of Buplerum falcatum extract implied that the observed cytotoxicities may have resulted from the detrimental effect of reactive oxygen species(ROS) evoked by Buplerum falcatum extract on the cancer cells.