• 한국균학회지
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• 제26권4호통권87호
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• pp.502-510
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• 1998

장수버섯 자실체로부터 분리된 강력한 항보체 활성 다당체인 FF-AP1을 정제하고 이것의 화학적 특성을 구명하기 위해 본 실험을 수행한 결과는 다음과 같다. ConA-Sepharose 4B affinity chromatography에 의해 FF-AP1은 $FF-AP1{\alpha}$와 $FF-AP1{\beta}$로 더 분리되었으며 이 중 항보체 활성의 주 유효 다당체인 $FF-AP1{\beta}$는 $10\;{\mu}g/ml$ 농도에서도 약 70%의 항보체 활성도를 나타내었다. $FF-AP1{\beta}$는 약 9.6%의 단백질을 함유한 산성다당체이며 glutamic acid와 aspartic acid의 함량이 상대적으로 다른 아미노산들에 비해 높았다. 이것의 분자량은 gel filtration법에 의해 15,000인 것으로 추정되었고 적외선 분광 분석에서 $890cm^{-1}$ 부근의 소peak를 탐지함으로써 ${\beta}$ glucosidic 결합의 존재를 확인하였다. Gas chromatography에 의한 구성당 조성 분석 결과, 주 구성당이 glucose, mannose, 및 galactose인 galacto-manno-glucan이었고, 소량의 rhamnose, xylose, fucose와 uronic acid도 탐지되었다.

• 한국재료학회지
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• 제26권1호
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• pp.47-53
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• 2016

Silicon nitride ($SiN_x:H$) films made by plasma enhanced chemical vapor deposition (PECVD) are generally used as antireflection layers and passivation layers on solar cells. In this study, we investigated the properties of silicon nitride ($SiN_x:H$) films made by PECVD. The passivation properties of $SiN_x:H$ are focused on by making the antireflection properties identical. To make equivalent optical properties of silicon nitride films, the refractive index and thickness of the films are fixed at 2.0 and 90 nm, respectively. This limit makes it easier to evaluate silicon nitride film as a passivation layer in realistic application situations. Next, the effects of the mixture ratio of the process gases with silane ($SiH_4$) and ammonia ($NH_3$) on the passivation qualities of silicon nitride film are evaluated. The absorption coefficient of each film was evaluated by spectrometric ellipsometry, the minority carrier lifetimes were evaluated by quasi-steady-state photo-conductance (QSSPC) measurement. The optical properties were obtained using a UV-visible spectrophotometer. The interface properties were determined by capacitance-voltage (C-V) measurement and the film components were identified by Fourier transform infrared spectroscopy (FT-IR) and Rutherford backscattering spectroscopy detection (RBS) - elastic recoil detection (ERD). In hydrogen passivation, gas ratios of 1:1 and 1:3 show the best surface passivation property among the samples.

• KSBB Journal
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• 제24권5호
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• pp.458-462
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• 2009

황산 수용액에 재생 피브로인을 녹이고 가열하여 황산을 반응물과 동시에 촉매로 사용하여 황산-피브로인을 제조 하였다. 황산의 농도 및 반응온도를 달리하여 얻어진 시료로부터 적외선 흡광 스펙트럼, UV 흡광 스펙트럼, NMR 및 GPC를 사용하여 반응조건에 따른 황산기의 도입 정도 및 피브로인 분자의 분해 정도를 분석하였다. 황산-피브로인의 수율은 5%의 황산을 사용하여 $60^{\circ}C$에서 반응시킬 때 가장 높았으며 적외선 흡광 스펙트럼의 $1109\;cm^{-1}$의 피크가 나타내는 도입된 황산기의 량은 황산의 농도가 증가하면 같이 증가하였다. 단백질에 도입된 황산기는 피브로인 분자를 주로 구성하고 있는 세린 및 타이로신의 hydroxyl 그룹과 반응하여 O-sulfate ester를 형성할 것으로 예상되는데, 이는 274 nm에서의 UV 흡광도의 감소 및 $3300\;cm^{-1}$의 적외선 흡광 스펙트럼의 감소가 관찰되는 결과와 일치하였다. GPC 분석을 통하여 황산-피브로인이 가수 분해되어 원래 피브로인의 분자량 보다 분자량이 작으며 동시에 가수분해된 저분자 황산 피브로인 펩타이드와 덜 가수분해된 비교적 분자량이 큰 펩타이드로 구성되어 있음이 확인되고 있다.

• 한국미생물·생명공학회지
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• 제41권1호
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• pp.60-69
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• 2013

Purified melanin pigment from Klebsiella sp. GSK was characterized by thermogravimetric, differential thermal, X-ray diffraction and elemental analysis. This melanin pigment is structurally amorphous in nature. It is thermally stable up to $300^{\circ}C$ and emits a strong exothermic peak at $700^{\circ}C$. Its carbon, hydrogen and nitrogen composition is 47.9%, 6.9% and 12.0%, respectively. It was used to scavenge metal ions and free radicals. After immobilizing the pigment and using it to adsorb copper and lead ions, the metal ion adsorption capacity was evaluated by atomic absorption spectroscopy (AAS) and the identity of melanin functional groups involved in the binding of metal ions was determined by Fourier transform infrared (FT-IR) spectroscopy. Batch adsorption studies showed that 169 mg/g of copper and 280 mg/g of lead were adsorbed onto melanin-alginate beads. The metal ion adsorption capacity of the melanin-alginate beads was relatively significant compared to alginate beads. The metal ion desorption capacity of HCl was greater (81.5% and 99% for copper and lead, respectively) than that of EDTA (80% and 71% for copper and lead, respectively). The ability of the melanin pigment to scavenge free radicals was evaluated by inhibition of the oxidation of 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and was shown to be about 74% and 98%, respectively, compared with standard antioxidants.

• 한국진공학회지
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• 제9권4호
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• pp.382-388
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• 2000

ECR-PECVD 방법을 이용하여 ECR power, $CH_4/H2$ 가스 혼합비와 유량, 증착시간, negative DC self bias 전압 등을 변화 시켜가면서 수소가 함유된 비정질 탄소 박막을 제조하고, 증착조건에 따른 박막의 결합구조 변화를 FTIR로 분석하였다. a-C:H 박막에 대한 FTIR 스팩트럼의 흡수 peak들은 2800~3000 $\textrm{cm}^{-1}$ 영역에서 관측되었으며, 대부분 $sp^3$ 결합을 하고있고 일부 $sp^2$ 결합구조가 존재함을 알 수 있었다. $CH_4/H_2$ 가스 혼합비와 유량의 미소 변화는 a-C:H 박막의 탄소와 수소의 결합구조에 큰 영향을 미치지 않았으며, 증착 시간이 증가할수록 탄소와 수소 원자들의 결합구조가 $CH_3$ 구조로부터 $CH_2$ 나 CH 구조로 변하고 있음을 확인하였다. 또한, bias 전압을 증가시킬수록 플라즈마에 의한 이온충돌 현상이 두드러져 탄소와 결합하고 있던 수소원자들이 떨어져 나가는 탈수소화 현상도 확인할 수 있었으며, 증착조건에 따른 a-C:H 박막의 결합구조 분석을 토대로 산업에 응용할 수 있는 높은 경도와 밀착성을 갖는 박막을 ECR-PECVD 방법으로 제조할 수 있음을 확인하였다.

• 한국광물학회지
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• 제9권2호
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• pp.55-63
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• 1996

Epidote occurs as veinlets in the propylitic alteration zone of the Bobae clay deposit, Pusan, Korea. Its cell parameters apparently decrease with the contents of Al, Fe, and Ca. Fourier transform infrared (FTIR) spectra show one hydrosyl environment related to AlM2 at 3357-3358 cm-1. In the mid-infrared region, the peaks at 950 and 1030 cm-1 sharper with increasing Al shifting to higher energy region. The peak at 885 cm-1 shifts slightly to a lower energy region with a decreasing intensity as the Fe content increases. In the far-IR region, epidote exhibits absorption bands at 120 and 140 cm-1, which are related to the Ca-O bonds in A-sites.M ssbauer spectra of epidote show that the isomer shifts of Fe3+ range from 0.36-0.37 at the M3 site and from 0.35-0.44 at M1 site. Fe2+ shows the isomer shift ranging from 1.11 to 1.13. Quadrupole splitting is 2.04 for Fe3+M3, 0.52-0.70 for Fe3+M1, and 2.61-2.70 for Fe2+M3. Calculation shows Fe3+M386-90.7%, Fe3+M12.5-3.6%, and Fe2+M35.8-11.4% of total iron, showing preferential distribution of Fe3+ in the M3 site. The Fe3+M3 content is between 0.486 and 0.513 per formula unit. in the Fe-rich epidote, less Fe3+ and more Fe2+ are accommodated in the M1 and M3 sites. Hence, the overall disorder increases as total Fe content increase. The ordering parameter of the Bobae epidote is 0.93-0.95, suggesting a disequilibrium state below 200$^{\circ}C$. The constant temperature over a long period may be essential for the transition from disordered state to equilibrium state, despite the possible variation in flux and composition of the hydrothermal fluid.

• 한국분말재료학회지
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• 제21권3호
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• pp.179-184
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• 2014

In this study, we prepare polymer solar cells incorporating organic ligand-modified Ag nanoparticles (O-AgNPs) highly dispersed in the P3HT:PCBM layer. Ag nanoparticles decorated with water-dispersible ligands (WAgNPs) were also utilized as a control sample. The existence of the ligands on the Ag surface was confirmed by FT-IR spectra. Metal nanoparticles with different surface chemistries exhibited different dispersion tendencies. O-AgNPs were highly dispersed even at high concentrations, whereas W-AgNPs exhibited significant aggregation in the polymer layer. Both dispersion and blending concentration of the Ag nanoparticles in P3HT:PCBM matrix had critical effects on the device performance as well as light absorption. The significant changes in short-circuit current density ($J_{SC}$) of the solar cells seemed to be related to the change in the polymer morphology according to the concentration of AgNPs introduced. These findings suggested the importance of uniform dispersion of plasmonic metal nanoparticles and their blending concentration conditions in order to boost the solar cell performance.

• 한국재료학회지
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• 제23권7호
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• pp.359-365
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• 2013

We investigated the nanostructural, chemical and optical properties of nc-Si:H films according to deposition conditions. Plasma enhanced chemical vapor deposition(PECVD) techniques were used to produce nc-Si:H thin films. The hydrogen dilution ratio in the precursors, [$SiH_4/H_2$], was fixed at 0.03; the substrate temperature was varied from room temperature to $600^{\circ}C$. By raising the substrates temperature up to $400^{\circ}C$, the nanocrystalite size was increased from ~2 to ~7 nm and the Si crystal volume fraction was varied from ~9 to ~45% to reach their maximum values. In high-resolution transmission electron microscopy(HRTEM) images, Si nanocrystallites were observed and the crystallite size appeared to correspond to the crystal size values obtained by X-ray diffraction(XRD) and Raman Spectroscopy. The intensity of high-resolution electron energy loss spectroscopy(EELS) peaks at ~99.9 eV(Si $L_{2,3}$ edge) was sensitively varied depending on the formation of Si nanocrystallites in the films. With increasing substrate temperatures, from room temperature to $600^{\circ}C$, the optical band gap of the nc-Si:H films was decreased from 2.4 to 1.9 eV, and the relative fraction of Si-H bonds in the films was increased from 19.9 to 32.9%. The variation in the nanostructural as well as chemical features of the films with substrate temperature appears to be well related to the results of the differential scanning calorimeter measurements, in which heat-absorption started at a substrate temperature of $180^{\circ}C$ and the maximum peak was observed at ${\sim}370^{\circ}C$.

• Archives of Pharmacal Research
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• 제18권4호
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• pp.231-236
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• 1995

Effects of sodium salts of various monovalent inorganic anions on transdermal permeation of salicylic acid were investigated. In in-vitro experiment using a Franz-type diffusion cell and excisicylic acid were investigated. In-vitro experiment using a Franze-type diffusion cell and excised mouse skin, the permeation-enhancing activities of the sodium salts of inoraganic anions were rougly proportional to lyotropic Hofmeister serlling abilities of the anions l F/sup -/

• Bulletin of the Korean Chemical Society
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• 제28권4호
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• pp.529-532
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• 2007

Combined temperature programmed reaction (TPR) and infrared (IR) spectroscopic studies for Fischer- Tropsch reaction have been performed over Ru/SiO2 and Ru-Ag/SiO2 supported catalysts. Reaction of linearly absorbed CO with hydrogen starts at 375 K over Ru/SiO2 catalyst and reaches maximum at 420 K accompanied with an intensity decrease of linear CO absorption. The reaction with bridged absorbed CO peaks around 510-535 K. Addition of Ag yields mixed Ru-Ag bimetallic sites while it suppresses the formation of bridged bonded CO. Formation of methane on this modified surface occurs at 390 K and reaches maximum at 444 K. Suppression of hydrogen on the Ag-doped surface also occurs resulting in the formation of unsaturated hydrocarbons and of CHx intermediates not observed with Ru/SiO2 catalyst. Such intermediates are believed to be the building blocks of higher hydrocarbons during the Fischer-Tropsch synthesis. Linearly absorbed CO is found to be more reactive as compared to bridged CO. The Ag-modified surface also produces CO2 and carbon. On this surface, hydrogenation of CO begins at 390 K and reaches maximum at 494 K. The high temperature for hydrogenation of absorbed CO and C over Ru-Ag/SiO2 catalyst as compared to Ru/SiO2 catalyst is due to the formation of Ru-Ag bimetallic surfaces impeding hydrogen adsorption.