• Polymer(Korea)
• /
• v.32 no.1
• /
• pp.56-62
• /
• 2008

Three types of network polyesters have been newly synthesized by a two-step condensation reaction by the various combination of several diols and diacids. When these polymer films were thermally treated at $240^{\circ}C$, they exhibited absorptions in a visible range despite the forbidden transition of carbonyl group. When excited at wavelengths above 330 nm, the polymers showed fluorescences in a wide visible range from blue to near yellow. These fluorescence phenomena are due to the formation of certain conjugated structures by the Knoevenagel type self-condensation under the high-temperature thermal treatment. These polymers showed significant difference in the thermal properties as a function of the degrees of chemical crosslinking. They also underwent photodegradation. Highly resolved, fluorescent image patterns were successfully obtained by the photodegradation of malonate group under a strong UV-light irradiation.

• Journal of Acupuncture Research
• /
• v.18 no.6
• /
• pp.161-170
• /
• 2001

목적 : 본 연구는 최근 임상에서 많이 사용하는 봉독약침액의 nitric oxide (NO)에 대한 소거효과를 분석하기 위하여 실행되었다. 방법 : 양성대조군으로 비타민과 실험군으로 국산 봉독과 미국산 봉독에 NO를 분비하는 S-nitroso-N-acetylpenicillamine (SNAP)을 투여한 후 NO의 농도를 540 nm 파장의 자외선 흡수량을 측정하여 평가하였다. 결과 : 국산 봉독은 $100{\mu}g/m{\ell}$에서 SNAP 처리 1.5, 3, 6 및 12시간에 대조군 (100%)과 비교하여 각각 $86.7{\pm}1.5,\;103.8{\pm}1.9,\;88.3{\pm}2.9$ 및 85.6{\pm}3.2%$의 잔류 NO 농도를 보였고, 1.5, 6 및 12시간에서 유의한 NO 소거 효과를 나타냈다. 미국산 봉독에서는 각각 $74.0{\pm}2.2,\;66.5{\pm}10.9,\;86.1{\pm}2.8$ 및 $59.1{\pm}3.8%$로 모든 시간에서 유의한 결과를 보였다. 결론 : 이상의 봉독의 NO 소거효과는 봉독 약침액이 임상에서 동통, 종창, 등에 치료에 사용하는 작용기전의 하나로 사료된다.

• Journal of the Korean Chemical Society
• /
• v.29 no.6
• /
• pp.575-581
• /
• 1985

Ultraviolet spectrophotometric investigations have been carried out on the systems of benzene, naphthalene and phenanthrene with iodine in carbon tetrachloride. The results reveal the formation of the one to one molecular complexes. The equilibrium constants were obtained in consideration of that absorption maxima due to the formation of the charge transfer complexes shift to blue with increasing temperature. Thermodynamic parameters for the formation of the charge transfer complexes were calculated from these values. These results indicate that the stabilities of the complexes formed between polynuclear aromatics and iodine increase with the number of aromatic rings. This may be a measure of the relative basicities of polynuclear aromatics toward iodine, which is explained in terms of the resonance of the interaction between aromatics and iodine. The results in this study were, additionally, compared with those of the polymethylbenzene series to be discussed the reason for them.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.14 no.2
• /
• pp.109-127
• /
• 2011

Atmospheric aerosols, small particles in the atmosphere, are one of the important parameters in climate change and human health. Additionally, accurate estimates of aerosol species are increasingly important in environmental impact assessment studies. Recent advances in global satellite remote sensing provide powerful tool for air quality monitoring. This study explores the potential usage of satellite derived data such as atmospheric aerosols for air quality monitoring as well as climate change study. The objectives of this study is to understand the general features of the global distribution of type dependent aerosols. A detailed spatio-temporal variability of the each different satellite dataset shows the variation of the global zonal average and specific geographical regions where the strong emission sources are located. Especially, significantly large aerosol amounts are observed in Asia and Africa because of the desert dust storm, anthropogenic and biomass burning emissions.

• Journal of the Korean Chemical Society
• /
• v.32 no.4
• /
• pp.377-384
• /
• 1988

Carotenoprotein from Salmo Salar eggs was purified and characterized by CM-cellulose, 50% $(NH_4)_2SO_4$, DEAE-cellulose and sephadex G-75 column. The chromoprotein had a spectrum with ${\lambda}_{max}$ 409, 540 and 580nm in p-buffer (pH 7.0) at initial step. Molecular weights by sephadex G-200 gel filtration were 50, 200 and 26,000 daltons. SDS-PAGE analysis showed a structure with four identical subunits (12,500 daltons). Its sample retained a small amount of carbohydrates and lipids. Amino acids were analyzed, and mannose, galactose and glucosamine also were identified. Carotenoid extacted with acetone was found to be astaxanthin ester by partition test, epoxy test, iodine test, allylic test, reduction, acetylation, uv/vis, ir and nmr datas. Stearate (47.9%) and palmitate (21.4%) were predominant fatty acids in the astaxanthin ester.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.7 no.6
• /
• pp.1302-1307
• /
• 2006

This study describes the preparation of high-performance photocatalyst and its environmental applications. We prepared visible-light response nano-particle photocatalyst exhibiting the similar photocatalytic activity with $TiO_2$, dispersed $TiO_2$ on $SiO_2$ with an active rutile type titanium oxide prepared at low temperature. The binder and stable photocatalytic $TiO_2$ sol for photocatalytic system were also prepared. Such products were evaluated by UV/Vis spectrometer, X-ray diffraction analysis, SEM, measurement of photocatalytic activities and surface area, mechanical properties of $TiO_2$-coated surfaces. The results obtained can be applied in efficient photocatalytic systems using POF and metal plate for the purification of air.

• Polymer(Korea)
• /
• v.33 no.1
• /
• pp.33-38
• /
• 2009

Monodisperse polystyrene and its copolymer beads containing amine function were prepared for the electroless silver plating using reduction of silver alkylcarbamate complex in organic solvent. Soap-free emulsion polymerization was adopted for the polymerization of styrene, divinylbenzene (DVB), and 2-(N,N-dimethylamino) ethyl methacrylate (DAEMA) in the presence of poly (vinyl alcohol) in a water/methanol solvent. The resulting poly (styrene/DVB/DAEMA), containing 30/0$\sim$1.5/0$\sim$3 wt% in monomer composition, were found to be a sphere-type particle with diameter of 1 ${\mu}m$. Silver Ag-coated polystyrene beads were prepared by in sito reduction of a silver 2-ethylhexylcarbamate (Ag-EHCB) complex solution with hydrazine without pretreatment of polystyrene beads. Robust Ag/polystyrene beads were analyzed by SEM, UV -visible spectrometer and XRD.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2013.08a
• /
• pp.184.2-184.2
• /
• 2013

대기압 플라즈마와 생체용액과의 상호작용은 Bio-medical 분야에서 주목 받고 있다. 대기압 플라즈마는 전자온도가 고온 플라즈마 보다 상대적으로 낮기 때문에 생체에 적용하기가 적합하다. 따라서 플라즈마가 세포에 미치는 영향을 관측하기 위해서 대기압 플라즈마를 이용하여 생체용액과의 반응을 살펴보고자 한다. Ar gas를 이용하여 플라즈마를 발생시켜 생체용액 표면을 처리하고 OES (Optical Emission Spectroscopy)을 이용해 방출 선을 조사했다. Ar 기체를 이용한 대기압 플라즈마를 사용하여 다른종류의 용액내의 OH Radical Density를 측정하였다. 용액으로는 DI (deionized) water 와 PBS (1x phosphate buffered saline)를 사용하였다. Ar gas를 200 sccm ($cm^3/min$) 으로 흐르게 하였을 때, DI water의 OH Radical Density 는 $4.33{\times}10^{16}cm^{-3}$ 으로 측정되었으며, 자외선 흡수분광법으로 측정한 완충용액인 PBS의 OH Radical Density 측정값은 $1.87{\times}10^{16}cm^{-3}$ 이다. 이런 특성을 기반으로, PBS 용액내의 H460 (Lung Cancer Cell) 와 L132 (Lung Normal Cell)을 깊이와 시간에 따라 대기압 플라즈마로 처리하여 cell의 변화를 보았다. 실험 각각의 조건은 깊이를 2 mm, 4 mm, 6 mm이며 시간은 10 sec, 30 sec, 60 sec 로 설정하였다. 표면으로부터의 깊이가 2 mm, 4 mm, 6 mm 일때 의 OH Radical Density는 각각 $1.87{\times}10^{16}cm^{-3}$, $0.5{\times}10^{16}cm^{-3}$, 0으로써 용액이 깊어질수록 OH Radical Density가 감소함을 볼 수 있다. OH radical density가 높은 2 mm 에서, 처리한 시간이 길어질수록 Cell 은 영향을 많이 받음을 관찰 할 수 있었다. H460 이 L132 보다 플라즈마에 영향을 많이 받음을 확인하였다. 특성변화를 알아보기 위하여 raman spectroscopy, flow cytometry, electron spin resonance로 측정한다.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2013.08a
• /
• pp.210.1-210.1
• /
• 2013

ZnO는 태양전지의 투명전극 및 윈도우 물질로 그 동안 광범위하게 사용되어 왔다. 하지만 태양광의 효율 증가를 위하여서는 가시광 영역뿐만 아니라 자외선 및 적외선 영역을 이용할 필요가 있다. 또한 금속 산화물 반도체 나노 입자는 크기를 조절하여 흡수하는 태양광의 파장 영역을 조절할 수 있고 이를 이용하여 이종구조를 사지는 고효율의 태양전지를 구현할 수 있다. 본 연구에서는 3.4 eV의 에너지 밴드갭을 가지는 ZnO박막내에 밴드갭을 조절 할 수 있는 금속 산화물 나노입자를 삽입하여 광학적, 전기적 특성을 연구하였다. ZnO 박막을 증착하기 전 유리 및 사파이어 기판에 스퍼터를 사용하여 Pt금속전극을 형성한 이후, ZnO 박막을 $1{\times}10^{-10}$ Torr의 기본 진공도를 유지하는 초고진공 스퍼터를 사용하여 100 nm 두께로 증착 하였다. 금속 산화물 나노 입자를 제작 하기 위하여, ZnO 박막에 열증착 장비(thermal evaporator)를 사용하여 In 나노 입자를 10 nm 이하의 크기로 제작 하였다. 그 상부에 초고진공 스퍼터 와 열증착 장비를 사용하여 ZnO 박막 및 In 나노 입자를 순차적으로 증착하여 수백 nm 두께의 ZnO 박막을 제작한다. ZnO 박막 내부에 형성된 In 양자점은 ZnO 증착공정 중에 산화되어 $In_2O_3$ 의 산화물 나노 입자로 형성되며, 내부의 구조는 투과전자 현미경을 사용하여 확인 하였다. 제작된 금속 산화물 나노입자가 포함된 ZnO 박막의 광학적 특성을 photoluminescence, UV-Vis spectroscopy, ellipsometry를 통하여 확인 하였으며, solar simulator와 전류-전압 특정 장비를 사용하여 전기적 특성을 분석 하였다.

• Ecology and Resilient Infrastructure
• /
• v.6 no.2
• /
• pp.128-135
• /
• 2019

This study evaluates the effect of dissolved effluent organic matter (SE-dEfOM) from sewage wastewater treatment plants on the adsorption and estrogenic activity of bisphenol A (BPA). Specific ultraviolet absorbance and fluorescence index analyses indicated that SE-dEfOM was mainly microbially derived non-humic substances differed from Suwannee River natural organic matter (SR-NOM) as reference. Both Langmuir and Freundlich models successfully explained the adsorption of BPA onto both SE-dEfOM and SR-NOM. Additionally, the SE-dEfOM showed higher binding capacities and affinities for BPA than those of SR-NOM, resulting in better reduction of the estrogenic activity of BPA. These findings suggest that the binding and toxicity of BPA are largely dependent on the source of organic matters.