• Journal of the Korean institute of surface engineering
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• v.37 no.3
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• pp.146-151
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• 2004

Indium tin oxide (ITO) is widely used to make a transparent conducting film for various display devices and opto-electric devices. In this study, ITO films on glass substrate were fabricated by inductively coupled plasma (ICP) assisted dc magnetron sputtering. A two-turn rf coil was inserted in the process chamber between the substrate and magnetron for the generation of ICP. The substrates were not heated intentionally. Subsequent post-annealing treatment for as-deposited ITO films was not performed. Low-temperature deposition technique is required for ITO films to be used with heat sensitive plastic substrates, such as the polycarbonate and acrylic substrates used in LCD devices. The surface roughness of the ITO films is also an important feature in the application of OLEDs along with the use of a low temperature deposition technique. In order to obtain optimum ITO thin film properties at low temperature, the depositions were carried out at different condition in changing of Ar and $O_2$ gas mixtures, ICP power. The electrical, optical and structural properties of the deposited films were characterized by four-point probe, UV/VIS spectrophotometer, atomic force microscopy(AFM) and x-ray diffraction (XRD). The electrical resistivity of the films was -l0$^{-4}$ $\Omega$cm and the optical transmittance in the visible range was ＞85%. The surface roughness ( $R_{rms}$) was -20$\AA$.>.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.04a
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• pp.7-7
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• 2018

Morinda 속 식물은 꼭두서니과(Rubiaceae)에 속하는 다년생 상록관목으로서 전세계 80여종이 분포하고 있다. 그중 노니는 2000년 전부터 동남아시아 지역에서 식품, 향신료, 음료, 자양강장제 등 다양한 분야에 사용되고 있으며 뿌리, 줄기, 잎, 열매의 식물체 전체 부위가 이용되고 있다. 특히 열매는 주스 등 다양한 제품으로 만들어지고 있다. 본 연구는 조직배양된 노니 부정근을 재료로 하여 항알러지의 효능평가를 수행하고 지표물질로 rubiadin을 선정하였으며 이물질에 대한 정제방법 및 구조분석을 통해 정성, 정량적 분석방법을 확립하였다. 항알러지 효능에 대한 측정 결과 노니 부정근 조추출물 $100{\mu}g{\cdot}mL^{-1}$에서 약 85%의 높은 발현 억제 효과를 보였고 이를 분획 추출한 후 분획물별로 histamine 및 $TNF-{\alpha}$ 발현 억제효과를 측정한 결과 헥산 및 메틸렌클로라이드층 분획물에서 효과가 우수하였다. 노니 부정근 조추출물이 함유한 유효성분들 중 항알러지 효과를 나타내는 지표물질을 선정하기 위하여 용매분획을 실시한 후 preparative LC로 분취하여 항알러지 효과가 높은 분획물을 얻었다. HPLC로 분취한 화합물을 GC/MS/MS, LC/MS-IT-TOF, UV/VIS spectrophotometer를 이용하여 최종적으로 rubiadin을 확인하고 이 화합물을 지표물질로 선정하였다. 이러한 결과는 노니 부정근의 고부가가치 기능성 소재로 이용되는데 도움이 될 것으로 기대한다.

• The Korean Journal of Ceramics
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• v.1 no.4
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• pp.191-196
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• 1995

Using sol-gel processing method, thin films of lathanum modified lead titanate(PLT) on Corning 7059 glass were prepared. A differential thermal analysis (DTA/TG) curve of gel powder and infrared spectra (FT-IR) of the films were measured to estimate residual organices in them. The heat-treated films were characterized by X-ray diffraction(XRD). Microstructures of the films were observed by a scanning electron microscope (SEM). Optical properties of the films were determined by a UV-VIS spectrophotometer. The waveguiding properties and optical attenuation were measured with the end coupling method and the cut back method. Effects of the drying conditions on the transmittance and the propagation loss of the films were investigated. Experimemtal results showed that the content of residual organics in the film decreased as the drying temperature of the film increased. As the La content of the film increased, the grain size decreased and the transmittance increased. The transmittances of the films increased with the increasing of the drying temperature. The propagation losses in the film decreased as the drying temperature increased.

• Journal of the Korea Institute of Military Science and Technology
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• v.13 no.1
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• pp.120-125
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• 2010

For application of transparent bulletproof materials, the SLS(soda-lime-silicate) glass was heated by 2-step crystallization. The DTA curve for SLS glass revealed the nucleation and crystal growth temperature at about $575^{\circ}C$ and $675^{\circ}C$, respectively. The crystallized glass was heated at various conditions(temperature, time). As a result, the maximum nucleation and crystal growth rates were $3.8\times10^5/mm^3{\cdot}hr$ at $575^{\circ}C$ and 20.58nm/min at $680^{\circ}C$, respectively. The bending strength, fracture toughness and vickers hardness were 451.7MPa, $0.9388MPa{\cdot}m^{1/2}$, and $693.9H_v$ which were 201%, 31%, and 22% higher than parent glass, respectively. Surface image and transmittance of crystallized SLS glass were analyzed by optical microscopy and UV/VIS/NIR spectrophotometer. Transmittance of crystallized SLS glass at visible-range(200~800nm) was not changed.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.229-230
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• 2008

본 논문에서는 비정질-결정질간 가역적 상변화 기록 매질로 이용되고 있는 $(Ag_{5.5}In_{6.5}Sb_{59}Te_{29})$ 합금 박막의 Ag 조성 증가에 따른 원자구조와 상변화 특성간의 상관관계를 연구하였다. 실험에 사용된 AgInSbTe 조성은 5N의 금속 파우더를 용융-냉각법으로 벌크를 제작하였고 열증착 방법으로 Si (100) 및 유리(corning glass, 7059) 기판위에 200 nm 두께로 박막을 증착하였다. 비정질 박막의 결정화속도를 평가하기 위해서 658 nm의 LD가 장착된 나노-펄스 스캐너를 이용하여 power; 1~17mW, pulse duration; 10~460 ns의 범위에서 각 조성의 상변화에 따른 반사도 차이를 측정, 비교 분석하였다. 또한 각각의 박막을 $100^{\circ}C$ 에서 $300^{\circ}C$까지 $50^{\circ}C$ 간격으로 $N_2$ 분위기에서 1시간동안 열처리 한 후 XRD와 UV-Vis-NIR spectrophotometer를 사용하여 각 상의 구조분석 및 광학적 특성을 분석하였으며, 4-point probe로 면저항을 측정하였다.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.29 no.12
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• pp.841-846
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• 2016

ZnO nanorods were grown on $SiO_2$ coated Si wafers and glass by the hydrothermal method. The structural and optical properties variation of ZnO nanorods as a function of growing time was studied. ~10 nm-thick ZnO thin films deposited on substrates by rf magnetron sputtering were employed as seed layers. Zinc nitrate hexahydrate (0.05 M) and hexamethylenetetramine (0.05 M) mixed in DI water were used as a reaction solution. ZnO nanorods were respectively grown for 30 min, 1 h, 2 h, 3 h, and 4 h by maintaining the reactor at $90^{\circ}C$. Crystallinity of ZnO nanorods was analyzed by X-ray diffraction, and the morphology of nanorods was observed by a field emission scanning electron microscope. Transmittance and absorbance were measured by a UV-Vis spectrophotometer, and energy band gap and urbach energy were obtained from the data. Photoluminescence measurements were carried out using Nd-Yag laser (266 nm).

• YAKHAK HOEJI
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• v.39 no.2
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• pp.175-184
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• 1995

The interaction of omeprazole(OMP) with $\gamma$-cyclodextrin($\gamma$-CyD) was investigated by solubility study and the complexation was confirmed by means of UV/VIS spectrophotometer, circular dichroism, differential scanning calorimeter, and $^{1}$H nuclear magnetic resonance spectra. The stability, dissolution rate, and partition coefficient of the complex were measured. The results present that the benzimidazole moiety and a part of pyridine ring containing sulfur atom of OMP might be included into the cavity of $\gamma$-CyD and the formation type of inclusion complex appeared to be B$_{s}$. The stoichiometric ratio of OMP to $\gamma$-CyD in the complex was found to be 1:1 and the stability constant of the complex found to be 97.1 M$^{-1}$. And the dissolution rate of OMP was markedly increased by inclusion complex formation with $\gamma$-CyD, and so it was above 90% in 5 min. from solid complex. Oil to water partition coefficient of OMP-$\gamma$-CyD complex was 60, which is significantly higher than that of OMP itself, 36.4. The degradation rate constant of OMP were greater than OMP-$\gamma$-CyD complex in aqueous solutions of various pHs, and the half lives of OMP and OMP-$\gamma$-CyD at pH 9 were 279.2 and 509.9 days, respectively, showing that the complex was more stable than OMP, therefore it was thought that OMP was stabilized by inclusion formation with $\gamma$-CyD.

• Bulletin of the Korean Chemical Society
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• v.30 no.3
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• pp.679-682
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• 2009

Utilizing a planar five coordinating N3S2 ligand, 2,6-bis(2-methylthiophenyliminomethyl)pyridine, a pseudo 7-coordinated manganese(II) complex with two labile triflate anions in the axial positions was synthesized. The reaction of the manganese(II) complex with an oxidant, iodosylbenzene, produced a metastable high-valent manganese(IV)-oxo species at 0 ${^{\circ}C}$. The high-valent Mn(IV)-oxo intermediate was characterized with a UV-vis spectrophotometer and an electrospray ionization mass spectroscopy. Reactivity studies of the Mn(IV)=O species revealed that the intermediate is capable of oxygenating $PPh_3$ and N-dealkylating N,N-dimethyl-toludine.

• Bulletin of the Korean Chemical Society
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• v.30 no.11
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• pp.2713-2716
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• 2009

$CuInS_{2}$ nanoparticles were synthesized by a simple sonochemical method; First, Cu nanoparticles were prepared from $CuInS_{2}$ in methanol solution by a one pot reaction through the sonochemistry under multibubble sonoluminescence (MBSL) conditions. Second, the resulting Cu nanoparticles were treated with $InCl_3{\cdot}4H_2O$ and $CH_3CSNH_2$ (thioacetamide) at the same MBSL conditions to synthesize $In_2S_3$-coated Cu nanoparticles in methanol solution. Then, they were transformed into $CuInS_{2}$ (CIS) nanoparticles of 20 $\sim$ 40 nm size in diameter by thermal heating at 300 ${^{\circ}C}$ for 2 hr. The prepared CIS nanoparticles, of which band gap is 1.44 eV, were investigated by X-ray diffractometer, UV-Vis spectrophotometer, inductively coupled plasma spectrometer, and high resolution-transmission electron microscope.

• Macromolecular Research
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• v.13 no.4
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• pp.327-333
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• 2005

pH-sensitive hydrogels were studied as a drug carrier for the protection of insulin from the acidic environment of the stomach before releasing it in the small intestine. In this study, hydrogels based on poly(ethylene oxide) (PEO) networks grafted with methacrylic acid (MAA) or acrylic acid (AAc) were prepared via a two-step process. PEO hydrogels were prepared by ${\gamma}-ray $ irradiation (radiation dose: 50 kGy, dose rate: 7.66 kGy/h), grafted by either MAA or AAc monomers onto the PEO hydrogels and finally underwent irradiation (radiation dose: 520 kGy, dose rate: 2.15 kGy/h). These grafted hydrogels showed a pH-sensitive swelling behavior. The grafted hydrogels were used as a carrier for the drug delivery systems for the controlled release of insulin. Drug-loaded hydrogels were placed in simulated gastric fluid (SGF, pH 1.2) for 2 hr and then in simulated intestinal fluid (SIF, pH 6.8). The in vitro drug release behaviors of these hydrogels were examined by quantification analysis with a UV-Vis spectrophotometer.