• 농업과학연구
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• 제43권5호
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• pp.715-722
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• 2016

Rapid determination of food quality is important in food distribution. In this study, the chemical properties of oats were analyzed using visible-near infrared (VIS-NIR) spectroscopy. The objective of this study was to develop and validate a predictive model of oat quality by VIS-NIR spectroscopy. A total of 200 oat samples were collected from domestic and import markets. Reflectance spectra, moisture, protein, fat, Fe, and K of oat samples were measured. Reflectance spectra were measured in the wavelength range of 400 - 2,500 nm at 2 nm intervals. The reflectance spectrum of an oat sample was measured after sample cell and reflectance plate spectrum measurement. Preprocessing methods such as normalization and $1^{st}$ and $2^{nd}$ derivations were used to minimize the spectroscopic noise. The partial-least-square (PLS) models were developed to predict chemical properties of oats using a commercial software package, Unscrambler. The PLS models showed the possibility to predict moisture, protein, and fat content of oat samples. The coefficient of determination ($R^2$) of moisture, protein, and fat was greater than 0.89. However, it was hard to predict Fe and K concentrations due to their low concentrations in the oat samples. The coefficient of determinations of Fe and K were 0.57 and 0.77, respectively. In future studies, the stability and practicability of these models should be improved by using a high accuracy spectrophotometer and by performing calibrations with a wider range of oat chemicals.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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• pp.418-418
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• 2012

We fabricated a new type of hybrid film using molecular layer deposition (MLD). The MLD is a gas phase process analogous to atomic layer deposition (ALD) and also relies on a saturated surface reaction sequentially which results in the formation of a monolayer in each sequence. In the MLD process, polydiacetylene (PDA) layers were grown by repeated sequential surface reactions of titanium tetrachloride and 2,4-hexadiyne-1,6-diol with ultraviolet (UV) polymerization under a substrate temperature of $100^{\circ}C$. Ellipsometry analysis showed a self-limiting surface reaction process and linear growth of the hybrid films. Polymerization of the hybrid films was confirmed by infrared (IR) spectroscopy and UV-Vis spectroscopy. Composition of the films was confirmed by IR spectroscopy and X-ray photoelectron (XP) spectroscopy. The titanium oxide cross-linked polydiacetylene (TiOPDA) hybrid films exhibited good thermal and mechanical stabilities.

• 방사선산업학회지
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• 제10권1호
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• pp.1-5
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• 2016

In this study, the effect of high-energy proton irradiation on the optical properties of polyacrylonitrile (PAN) films was investigated. PAN thin films spin-coated on a substrate were irradiated 150 keV proton ions at various fluences. The changes in the chemical structure and optical properties were investigated by FT-IR and UV-vis spectroscopy. The results of the FT-IR analysis revealed that the cyclization reaction took place by proton irradiation and the degree of cyclization increased with an increasing fluence. Based on the UV-vis analysis, the optical band gap of PAN decreased from 2.84 to 2.52 eV with an increasing fluence due to the formation of carbon clusters by proton irradiation. In addition, the number of carbon atoms per carbon cluster and the number of carbon atoms per conjugation length were found to be increased with an increasing fluence.

• 공업화학
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• 제27권6호
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• pp.669-671
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• 2016

본 연구에서는 수열합성법을 이용하여 수산화인회석을 합성하였다. 또한 이온 교환 반응을 통하여 수산화인회석 표면에 은을 도입하였다. 합성된 샘플의 결정성과 형태를 X-선 회절 분석과 투과전자현미경을 통하여 분석하였으며, 산란 반사 UV-vis 스펙트럼을 통하여 합성한 샘플의 광학적 특성을 조사하였다. 은이 도핑된 수산화인회석의 경우 은이 수산화인회석 표면에 나노입자 형태로 존재한다는 것을 X-선 회절 분석과 투과전자현미경 실험으로 확인하였다. 특히 수산화인회석과 비교하여 은 나노 입자가 도입된 수산화인회석의 경우에는 UV-Vis 영역에서 높은 흡광도를 나타내었다.

• Bulletin of the Korean Chemical Society
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• 제35권2호
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• pp.392-396
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• 2014

New organic-inorganic composite of 2,4-dihydroxybenzophenone (BP-1) encapsulation into dodecylbenzenesulfonate (DBS) modified layered double hydroxide (LDH) was successfully prepared. The surface, structural, thermal and absorption properties of the BP-1/DBS-LDH nanohybrid was characterized by BET analysis, scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TG) and diffuse reflectance UV-Vis absorbance spectra (DRUV-vis). The interlayer configuration of composite and the adsorption mechanism of BP-1 on MgAl-DBS-LDH were discussed. It was suspected that DBS anions located in the form of monolayer arrangement with a $75^{\circ}$ anti parallel angle between dodecylbenzenesulfonate chain axis. The diffuse reflectance UV-Vis absorbance results revealed that the UV absorbing wavelength of BP-1/DBS-LDH evidently extends to about 400 nm, which shows that the BP-1/DBS-LDH has the potential application as a UV absorber.

• 한국산학기술학회논문지
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• 제11권1호
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• pp.29-36
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• 2010

합성과 천연 에메랄드의 열처리에 따른 분광특성 변화를 가시광선과 적외선 분광분석으로 관찰하였다. X-선 형광분석 결과 flux 합성 에메랄드에서는 Mo과 Co이 검출 되었고, hydrothermal 합성 에메랄드에서는 Cl 성분이 나타났다. 자외선-가시광선 분광분석 결과는 콜롬비아산 에메랄드 시료에서 열처리 후에 전체적인 흡수 세기가 증가 한 것을 확인 하였다. 적외선 분광 분석 결과, hydrothermal 합성 에메랄드에서 Cl 성분에 관련된 피크가 $3000-2600cm^{-1}$에서 나타났고, 천연 에메랄드에서는 $CO_2$에 기인하는 $2358cm^{-1}$피크가 열처리후에 감소된 것을 확인하였다. 이는 열처리 후에 기체 성분이 변화된 것과 일치 하였다.

• 한국산학기술학회논문지
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• 제15권1호
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• pp.39-46
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• 2014

미얀마 Kayah산 녹색 투어말린의 특성을 X-선 형광분석, 자외선-가시광선 그리고 중적외선 분광분석을 통하여 타산지의 녹색 투어말린과 비교하였다. 화학성분 분류에 의해 미얀마 투어말린이 속한 그룹을 조사 하였다. 미얀마 투어말린은 V 원소를 많이 함유하고 있었고 X 사이트에 Ca 원소를 반 이상 함유한 Calcic 그룹에 속했고 우바이트 (Uvite)로 명명되었다. 자외선-가시광선 분석결과 $V^{3+}$ 이온에 의한 415와 611 nm에 강한 흡수밴드가 나타나 녹색 투어말린의 원인이 되었다. $Fe^{2+}$ 이나 $Cu^{2+}$ 이온에 의해 녹색이 나타나는 타산지의 녹색 투어말린과 차이가 있었다. 중적외선 분석에서는 수산기와 금속들 간의 진동에 의한 흡수가 일어났는데 1100 $cm^{-1}$ 근처에서 스트레칭 모드, 3500 $cm^{-1}$ 주변에서 벤딩 모드 그리고 4600과 4200 $cm^{-1}$ 사이에서 스트레칭과 벤딩 모드의 혼합 밴드가 나타났다.

• Journal of Microbiology and Biotechnology
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• 제24권4호
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• pp.453-464
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• 2014

The current research was focused on the extracellular biosynthesis of bactericidal silver nanoparticles (AgNPs) using cell-free supernatant of a local isolate previously identified as a novel Streptomyces aegyptia NEAE 102. The biosynthesis of silver nanoparticles by Streptomyces aegyptia NEAE 102 was quite fast and required far less time than previously published strains. The produced particles showed a single surface plasmon resonance peak at 400 nm by UV-Vis spectroscopy, which confirmed the presence of AgNPs. Response surface methodology was chosen to evaluate the effects of four process variables ($AgNO_3$ concentration, incubation period, pH levels, and inoculum size) on the biosynthesis of silver nanoparticles by Streptomyces aegyptia NEAE 102. Statistical analysis of the results showed that the linear and quadratic effects of incubation period, initial pH, and inoculum size had a significant effect (p < 0.05) on the biosynthesis of silver nanoparticles by Streptomyces aegyptia NEAE 102. The maximum silver nanoparticles biosynthesis (2.5 OD, at 400 nm ) was achieved in runs number 5 and 14 under the conditions of 1 mM $AgNO_3$ (1-1.5% (v/v)), incubation period (72-96 h), initial pH (9-10), and inoculum size (2-4% (v/v)). An overall 4-fold increase in AgNPs biosynthesis was obtained as compared with that of unoptimized conditions. The biosynthesized silver nanoparticles were characterized using UV-VIS spectrophotometer and Fourier transform infrared spectroscopy analysis, in addition to antimicrobial properties. The biosynthesized AgNPs significantly inhibited the growth of medically important pathogenic gram-positive (Staphylococcus aureus) and gram-negative bacteria (Pseudomonas aeruginosa) and yeast (Candida albicans).

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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• pp.1057-1059
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• 2003

New polyfluorene derivatives, poly[9,9-bis(4' n-octyloxyphenyl)] fluorene (PAPF-8) and poly[9,9-bis(4'-(2",7"-dimethylocyloxy)phenyl)] fluorene (PAPF-10) were synthesized from the monomers, 2,7-dibromo-9,9-bis[4' (2"-ethylhexyloxy)benzene] fluorene and 2,7-dibromo-9,9-bis[4' (2", 7"-dimethyloctyloxybenzene)] fluorene through the Ni(0) mediated polymerization. The copolymers were characterized using FT-IR spectroscopy, UV-vis spectroscopy, TGA, photoluminescence (PL) & electroluminescence (EL) spectroscopy, elementa analysis, and molecular weight studies. The synthesized POPF-8 and POPF-10 showed a pure blue emission without any spectral change upon thermal annealing and EL device operation.

• 한국응용과학기술학회지
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• 제14권2호
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• pp.81-85
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• 1997

Tris(8-hydroxyquinoline)-aluminum complex($AlQ_3$) having greenish luminescent characteristics was synthesized and it was confirmed with UV-Vis absorption spectroscopy, elemental analysis, and FT-IR spectroscopy that $AlQ_3$ was successfully synthesized. Thin films of $AlQ_3$ having multilayer structure were prepared by spin coating method and vacuum evaporation technique. Photopluminescent characteristics of these films were investigated by Luminescence spectroscopy and Current-Voltage(I-V) characteristics of these films were also investigated.