• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집 Vol.14 No.1
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• pp.108-111
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• 2001

ZnO thin films on (001) sapphire substrates have been deposited by pulsed laser deposition(PLD) technique for light emitting device applications. We have controlled the emission intensity of UV and visible light, depending on film thickness and various post-annealing time. UV emission became strong as the thickness of ZnO thin films increased. The intensity of visible light was strong as post-annealing temperature increased. The optical properties of the ZnO thin films were characterized by PL(photoluminescence) and the structural properties of the ZnO were characterized by XRD for the application of ZnO light emission device.

• 한국대기환경학회지
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• 제26권6호
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• pp.649-656
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• 2010

Boron-doped $TiO_2$ photocatalysts were synthesized by a modified sol-gel method and their photocatalytic activities were performed and compared with those of pure synthetic and commercial $TiO_2$ catalysts under UV or visible light conditions. Pure $TiO_2$ itself exhibited very negligible photocatalytic performance under visible light conditions in the aspects of toluene decomposition reactions, although significant decomposition potential was observed as expected with UV light conditions. However, boron doping over $TiO_2$ significantly improved photocatalytic activity particularly under visible conditions, where over 95% degradation of toluene was achieved with 1wt% $B-TiO_2$ within 2 hrs. All the decomposition reactions seemed to follow pseudo first-order kinetics. The effects of boron-doping and its characteristics are further discussed through the kinetic studies and comparison of results.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 1995년도 추계학술발표회논문집
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• pp.115-117
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• 1995

This paper describes the O.T aging analysis by non-destructive electrical and UV/visible method. Non-destructive diagnosis method is tan8 test. Also the new method of the aging analysis, UV/visible method was introduced in this paper and compared with the non-destructive electrical method. The UV/visible test could be useful method for the O.T aging electrical diagnosis such as non-destructive electrical method.

• 대한소아치과학회지
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• 제23권2호
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• pp.327-346
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• 1996

The purpose of this study was to evaluate the shear bond strengths, microhardness, compressive strength and contraction gap at the resin-tooth interface of two types of composite resins polymerized with visible light and argon laser sourse. The results from the present study can be summarized as follows ; 1. Resin samples polymerized either by argon laser or visible light did not show significant difference in their physical properties tested(p>.05). 2. The contraction gap at the resin tooth interface was found to be present in all samples but any significant difference between groups could not be established due to their variability. Although the superiority of argon laser over visible light in enhancing the physical properties of resin could not be elucidated in the present study, continous efforts are deemed to be worthwhile to investigate this area using different conditions and materials of experiment.

• 한국세라믹학회지
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• 제48권3호
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• pp.211-216
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• 2011

Nickel oxide-doped ACF and $TiO_2$ composites (NiO/ACF/$TiO_2$) were prepared by a sol-gel method. The composite obtained was characterized by BET surface area measurements, X-ray diffraction, transmission electron microscopy and energy dispersive X-ray analysis. A methylene blue (MB) solution under visible light irradiation was used to determine their photocatalytic activity. Excellent photocatalytic degradation of the MB solution was observed using the $TiO_2$, Ti-ACF and NiO/ACF/$TiO_2$ composite under visible light.

• 한국통신학회논문지
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• 제40권10호
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• pp.2065-2067
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• 2015

본 논문에서는 Rolling Shutter CMOS 센서를 이용한 가시광 통신 시스템의 성능을 분석하였다. 성능분석을 위하여 ISI (Inter-symbol Interference)가 가시광통신에 미치는 영향을 분석하였다. 모의실험을 통하여 분석결과의 타당성을 검증하였다.

• Bulletin of the Korean Chemical Society
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• 제31권4호
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• pp.925-928
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• 2010

Nitrogen-doped $TiO_2$ ($TiO_2$:N) nano-particles with a pure anatase crystalline structure were successfully synthesized through the hydrolysis of $TiCl_4$ in an ammonia aqueous solution. The samples were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), $N_2$-sorption, and UV-vis diffuse reflectance spectra (UV-vis DRS) techniques. The absorption edge of nitrogen-doped $TiO_2$ shifted into the visible wavelength region. The photoelectrochemical (PEC) performances were investigated for the $TiO_2$ mesoporous electrodes doped with different nitrogen concentrations. The $TiO_2$:N electrodes exhibited much higher PEC responses compared to the pure $TiO_2$ electrode because of the significantly enhanced visible-photoresponsibility of the $TiO_2$:N electrodes.

• Bulletin of the Korean Chemical Society
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• 제33권4호
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• pp.1269-1274
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• 2012

A visible light responsive N, Mo co-doped $TiO_2$ were prepared by sol-gel method. X-ray diffraction, TEM, $N_2$ adsorption, UV-vis spectroscopy, photoluminescence, and X-ray photoelectron spectroscopy were used to characterize the prepared $TiO_2$ samples. Doping restrained the phase transformation from anatase to rutile and reduced the particle sizes. The band gap was much narrowed after N, Mo co-doping. The photocatalytic activities were tested in the degradation of an aqueous solution of a reactive dyestuff, methylene blue, under visible light. The photocatalytic activities of doped $TiO_2$ were much higher than that of neat $TiO_2$. The photocatalytic stability of N, Mo co-doped $TiO_2$ was much better than that of N doped $TiO_2$.

• Bulletin of the Korean Chemical Society
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• 제30권11호
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• pp.2613-2616
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• 2009

FeOOH/$TiO_2$, a heterojunction structure between FeOOH and $TiO_2$, was prepared by covering the surface of the $\sim$100-nm-sized FeOOH particles with Degussa P25 by applying maleic acid as an organic linker. Under visible light irradiation (${\lambda}{\geq}$ 420 nm), FeOOH/$TiO_2$ showed a notable photocatalytic activity in removal of gaseous 2-propanol and evolution of $CO_2$. It was found that FeOOH reveals a profound absorption in the spectral range of 400 - 550 nm, and its valence band (VB) level is located relatively lower than that of $TiO_2$. The considerable photocatalytic efficiency of the FeOOH/$TiO_2$ under visible light irradiation was therefore deduced to be caused by the hole transfer between the VB of FeOOH and $TiO_2$.

• 대한화학회지
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• 제18권4호
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• pp.289-296
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• 1974

Bombina Orientalis(무당개구리)의 복피로부터 암적색의 색소를 추출하여 TLC 및 column chromatography 로 10여종의 carotenoid를 분리하여 visible 및 IR-spectrum을 조사하였다. 물리, 화학적 성질, chromatomatographic 성질 visible 및 IR-spectral 특성을 이용하여 주색소는 ${\beta}$-carotene과 4-hydroxy-echinenone임을 확인하였다.