• 분석과학
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• 제14권6호
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• pp.522-529
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• 2001

알데히드 기를 가지는 당류가 알칼리 용액 하에서 발생되는 일산화탄소를 알칼리의 농도, 반응 온도 및 시간에 따라 분석하였다. 락토스를 포함하고 있는 우유에서 $25^{\circ}C$와 $40^{\circ}C$의 조건으로 1.0 M NaOH와 0.01 M NaOH 용액 하에서 생성되는 일산화탄소를 정량 분석하였다. 또한 0.1 M lactose와 0.1 M xylose 각각 20 mL와 1.0 M NaOH용액 2 mL를 $50^{\circ}C$에서 48시간 동안 반응시키면서 발생되는 일산화탄소를 신선한 혈액에 bubbling 시킨 다음 그 혈액에서 일산화탄소-헤모글로빈의 농도를 측정한 결과 일산화탄소-헤모글로빈의 농도가 31%였으며, 일산화탄소-헤모글로빈 특유의 UV spectrum을 얻을 수 있었다. 같은 방법으로 우유 30 mL에 20 mL의 1.0 M NaOH를 가하여 $50^{\circ}C$에서 48시간 72시간동안 반응시키면서 발생되는 일산화탄소를 신선한 혈액에 bubbling 시킨 다음 혈중 일산화탄소-헤모글로빈의 농도를 측정한 결과 일산화탄소-헤모글로빈의 농도는 각각 32%와 42%를 나타내었다.

• 한국전기전자재료학회논문지
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• 제29권9호
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• pp.539-545
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• 2016

Alumina added with Mn3O4 up to 7.5 cat% of Mn was prepared by conventional ceramic processing, and the sintering behavior and the optical properties of which were studied as functions of Mn content. Densification and grain growth of alumina were enhanced by Mn addition up to 0.75 cat% but was leveled off at higher concentrations. XRD revealed that $Al_2MnO_4$(galaxite) was formed as a second phase in the specimens with more than 0.75 cat% of Mn. Thus it is believed that either the solid solution effect of Mn or the Zener effect of $Al_2MnO_4$ becomes predominant in the sintering of Mn-added $Al_2O_3$ according to the additive concentration. UV-VIS reflectivity(SCI) spectra of Mn-added $Al_2O_3$ consisted of smooth bottoms in 300~550 nm wavelength range and plateaus at wavelengths longer than 650 nm. The reflectivity spectrum continuously moved downward, and the specimen color became darker and thicker with increasing Mn content. The CIELAB color change with respect to standard white was also dependent on the amount of Mn added: ${\Delta}L^*$(D65) negatively increased and ${\Delta}E_{ab}^*$(D65) positively increased with increasing Mn content, probably due to Mn substitution to Al and/or the mixing effect of black $Al_2MnO_4$ as a second phase.

• 한국전기전자재료학회논문지
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• 제27권12호
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• pp.820-824
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• 2014

TiNOx multi-layer thin films on aluminum substrates were prepared by DC reactive magnetron sputtering method. 4 multi-layers of $TiO_2$/TiNOx(LMVF)/TiNOx(HMVF)/Ti/substrate have been prepared with ratio of Ar and ($N_2+O_2$) gas mixture. $TiO_2$ of top layer is anti-reflection layer on double TiNOx(LMVF)/TiNOx(HMVF) layers and Ti metal of infrared reflection layer. In this study, the crystallinity and surface properties of TiNOx thin films were estimated by X-ray diffraction(XRD) and field emission scanning electron microscopy(FE-SEM), respectively. The grain size of TiNOx thin films shows to increase with increasing sputtering power. The composition of thin films has been investigated using electron probe microanalysis(EPMA). The optical properties with wavelength spectrum were recorded by UV-Vis-NIR spectrophotometry at a range of 200~1,500 nm. The TiNOx multi-layer films show the excellent optical performance beyond 9% of reflectance in those ranges wavelength.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2009년도 제38회 동계학술대회 초록집
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• pp.149-149
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• 2010

The double-layer antireflection (DLAR) coatings have significant advantages over single-layer antireflection (SLAR) coatings. This is because they will be able to cover a broad range of the solar spectrum which would enhance the overall performance of solar cells. Moreover films deposited at high frequency are expected to show excellent and UV-stable passivation in the refractive index that we adopted. In this work, we present a novel DLAR coating using SiNx:H thin films with refractive indices 1.9 and 2.3 as the top and bottom layers. This approach is cost effective when compared to earlier DLAR coatings with two different materials. SiNx:H films were deposited by Plasma enhanced chemical vapor deposition (PECVD) technique using $SiH_4$, $NH_3$ and $N_2$ gases with flow rates 20~80sccm, 200sccm and 85 sccm respectively. The RF power, plasma frequency and substrate temperature for the deposition were 300W, 13.56 MHz and $450^{\circ}C$, respectively. The optimum thickness and refractive indices values for DLAR coatings were estimated theoretically using Macleod simulation software as 82.24 nm for 1.9 and 68.58 nm for 2.3 respectively. Solar cells were fabricated with SLAR and DLAR coatings of SiNx:H films and compared the cell efficacy. SiNx:H> films deposited at a substrate temperature of $450^{\circ}C$ and that at 300 W power showed best effective minority carrier lifetime around $50.8\;{\mu}s$. Average reflectance values of SLAR coatings with refractive indices 1.9, 2.05 and 2.3 were 10.1%, 9.66% and 9.33% respectively. In contrast, optimized DLAR coating showed a reflectance value as low as 8.98% in the wavelength range 300nm - 1100nm.

• 미생물학회지
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• 제33권4호
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• pp.252-256
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• 1997

담자균류 백색부후균의 일종인 흰구름버섯(Coriolus hirsutus)을 실험균주로 하여 수종의 난분해성 방향족염료의 분해능을 측정하였다. 사용된 4종류의 염료 중, triphenyl methane 염료인 bromophenol blue가 탈색율 95% 이상으로 가장 잘 탈색되었으며, Congo red와 Poly R-478은 이보다는 낮은 57%, 55%가 탈색되었다. 그러나, heterocyclic 염료인 methylene blue는 본 균주에 의해 거의 탈색되지 않았으며, UV-visible spectrum상에서의 심색성 이동만 관찰되었다. 세포외 laccase와 peroxidase의 활성은 각 염료의 탈색율과 비례하여 나타났으며, 최대 활성 또한 최대 탈색시기에 관찰되었다. 효소의 활성 염색시 모든 염료의 탈색배지에서 공통적인 laccase와 peroxidase의 활성 띠가 관찰되었다. 이러한 결과로 볼 때, 세포외 laccase와 peroxidase가 난분해성 염료의 탈색에 중요한 역할을 할 것으로 판단된다.

• 한국재료학회지
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• 제16권12호
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• pp.754-760
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• 2006

Mercaptoundecanoic acid (MUA) has been used to enhance the dispersity of Au nanoparticles in organic solvent and the affinity between the Au nanoparticles surface and titanium dioxide shell in the synthesis of $Au/TiO_2$ core-shell composite nanoparticles. The dispersity of the MUA-coated Au nanoparticles in ethanol aqueous solution with different concentration of $H_2O$ was investigated by UV-Vis. absorption spectrum and the coating amount of MUA was varied from 0.02 mM to 1.0 mM. The MUA-coated Au nanoparticles were highly dispersed in pure $H_2O$ in the wide range of the coating amount of MUA. On the contrary, the MUAcoated Au nanoparticles showed an enhanced stability in the ethanol/$H_2O$=8/2 mixed solution only when the coating amount of MUA was 0.05 mM, and in the ethanol/$H_2O$=7/3 mixed solution when the coating amount of MUA was in the range from 0.02 mM to 0.17 mM. From this systematic study, it can be inferred that the stability and the dispersibility of Au nanoparticles in organic solvents are highly sensitive towards the amount of MUA coating.

• 한국식품과학회지
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• 제32권5호
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• pp.985-990
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• 2000

${\zeta}-Carotene$를 dichloromethane에 용해하고 dry ice 상에서 ozonolysis을 행하였다. Ozonolysis에 의해 생성된 화합물은 silica gel chromatography를 행하여 분획하고, photodiode array detector를 이용하여 ODS-HPLC로 분석하였다. Toluene에 ${\zeta}-carotene$을 용해하고 $37^{\circ}C$, 72시간 자동산화시킨 결과, 다수의 carbonyl 및 acidic화합물이 생성되었다. ${\zeta}-Carotene$의 자동산화로부터 생성된 carbonyl 화합물의 대부분은 ozonolysis에 의하여 얻어진 산화개열산물이 나타내는 HPLC상의 거동과 분광학적 특성이 서로 잘 일치하였다. 또한 ${\zeta}-carotene$의 자동산화에 의해 생성된 중앙개열 acidic 화합물은 생물활성을 나타내는 4,5-didehydrogeranyl geranyl acid 표준품과 동일한 분광학적 특성을 나타냈다. 이러한 결과는 in vitro상의 산화적 조건하에서 ${\zeta}-carotene$ 자동산화에 의해 eccentric cleavage가 생성됨을 알 수 있었다.

• 한국염색가공학회지
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• 제11권3호
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• pp.15-22
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• 1999

This study investigated the mordanting effect of natural mordants such as camellia ash, bean chaff ash and pyrolignite of iron(Iron(II) Acetate) on silk fabrics dyed with green tea extracts. Experimental variables include the conditions of extraction and dyeing, and types of natural mordants. Inorganic ion contents In natural mordants were analysed by Induced Coupled Plasma Atomic Emission Spectrometer. In the ash Al, Fe, Si and Mn were in % unit, Cr and Ni were detected in ppm unit, and in the aqueous extracts of the ash all the metal ions were in ppm unit. On the other hand, fairly high content of Al(2.13% ) in camellia ash extract and Fe(7.91% ) in the aqueous extracts of pyrolignite iron were detected. The absorbance intensity of green tea extracts in UV-Visible spectrum increased with the temperature and time of extraction. The maximum absorption wavelength of the extracts appeared at 272.5nm and 210.5nm. The US values of silk fabrics dyed with green tea extracts were increased with temperature and time of dyeing. Surface color of silk fabric dyed with green tea extracts was 9.1YR, but it was changed from 7.9YR to 7.5YR by camellia ash extract and 7.4YR to 6.4YR by bean chaff ash extract with increase in mordant concentration. Pre-mordanted and post-mordanted fabrics with pyrolignite of iron were changed from 1.4YR to 1.1R and 7.2P to 4.2P, respectively.

• 한국표면공학회지
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• 제25권5호
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• pp.271-281
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• 1992

Amorphous hydrogenated silicon carbide(a-Si1-xCx : H) films have been prepared by the rf sputtering using a silicon target in a gas mixture of Argon and methane with varying methane gas flow rate(fCH) in the range of 1.5 to 3.5 sccm at constant Argon flow rate of 30sccm and rf power in the range of 3 to 6 W/$\textrm{cm}^2$. The effects of methane flow rate and rf power on the structure and optical properties of a-Si1-xCx : H films have been analysed by measuring both the IR absorption spectrum and the UV transmittance for the films. With increasing the methane flow rate, the optical band gap(Eg) of a-Si1-xCx : H films increases gradually from 1.6eV to the maximum value of 2.42eV at rf power of 4 W/$\textrm{cm}^2$, which is due to an increases in C/Si ratio in the films by an significant increase in the number of C-Hn bonds. As the rf power increases, the number of Si-C and Si-Hn bonds increases rapidly with simultaneous reduction in the number of C-Hn bonds, which is associated with an increase in both degree of methane decomposition and sputtering of silicon. The effects of rf power on the Eg of films are considerably influenced by the methane flow rate. At low methane flow rate, the Eg of films decreased from 2.3eV to 1.8eV with the rf power. On the other hand, at high methane flow rate, that of films increased slowly to 2.4eV.

• 한국표면공학회지
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• 제48권5호
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• pp.211-217
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• 2015

To fabricate white LED having a high color rendering index value, red color phosphor mixed with the green color phosphor together in the blue chip, namely the blue chips with RG phosphors packaging is most favorable for high power white LEDs. In our previous papers, we reported on successful syntheses of $Sr_{2-}$ $Si_5N_8:Eu^{2+}$ and $CaAlSiN_3$ phosphors for red phosphor. In this work, for high power green phosphor, greenemitting ternary nitride $Ba_3Si_6O_{12}N_2:Eu^{2+}$ phosphor was synthesized in a high frequency induction furnace under $N_2$ gas atmosphere at temperatures up to $1400^{\circ}C$ using $EuF_3$ as a raw material for $Eu^{2+}$ dopant. The effects of molar ratio of component and experimental conditions on luminescence property of prepared phosphors have been investigated. The structure and luminescence properties of prepared $Ba_3Si_6O_{12}N_2:Eu^{2+}$ phosphors were investigated by XRD and photoluminescence spectroscopy. The excitation spectra of $Ba_3Si_6O_{12}N_2:Eu^{2+}$ phosphors indicated broad excitation wavelength range of 250 - 500 nm, namely from UV to blue region with distinct enhanced emission spectrum peaking at ${\approx}530nm$.