• Polymer(Korea)
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• v.27 no.5
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• pp.413-420
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• 2003

Fluorescence microscope technique was employed for the characterization of phase separation behavior of a 4-chloro-7-nitrobenzofurazan labeled polystyrene (PS) / polybutadiene (PB) blend in dioctyl phthalate under steady shear. It was confirmed that the fluorescence microscope images reflect the real phase morphology by comparing with the images of phase contrast microscope. Comparing the fluorescence intensities from the phase separated domain (PS rich) and continuous phase (PB rich), the composition difference between these two phases were deduced. The observed shear dependence of compositional change is then used to confirm that the phase diagram is indeed shifted under the steady shear.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.532-535
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• 2000

Optical microscope, SEM and fluorescent microscope were used for qualitative and morphological studies of the attachment bacteria on PE substratum under anaerobic condition. The observation of optical microscopic has demonstrated that the initial attachment of bacteria began in crevices of surface. In SEM photographs, shape and structure of biofilm could be observed, but bacteria species and methanogens was not identified. A large number of methanogenic bacteria were showed on the surface of PE substratum by fluorescence under 480nm of radiation. It was estimated that methanogenic bacteria was related to initial attachment of bacteria under anaerobic condition.

• Korean Journal of Microbiology
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• v.37 no.1
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• pp.61-65
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• 2001

Epifluorescence microscopy was used to observe epiphytic bacteria directly on plant leaf surfaces as well as indirectly in the leaf liberating solution by staining with fluorochromes of 4',6-diamidino-2-phenylindole (DAPI) and acridine orange(AO). Epiphytic bacteria could not be well observed on the leaf surface by staining with AO due to an intrusive orange or red background fluorescence. However, DAPI gave us clear epifluorescent images of the bacteria on the leaf. On the contrary, epiphytic bacteria in the liberating leaf solution were well observed on filters stained by both types of fluorochrome, although DAPI showed better fluorescent images than AO and not necessarily required a washing step of the filters stained. The optimum conditions of the DAPI stains were 5 $\mu$g/ml for 5 min both for leaves and for filters of the liberating solution. It was confirmed that a critical step in the epifluorescence microscopy of leaf surfaces was to minimize release of water from the leaf. For this, the stained leaf samples were put on a filter paper, kept in a dry oven at $70^{\circ}C$ for 2 min instead of air-drying, and then immediately observed by epifluorescence microscopy. The established technique was applied to enumerate epiphytic bacteria on oak tree leaf surfaces.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.229.2-229.2
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• 2015

전자현미경은 전자빔을 이용하여 나노 수준의 분해능으로 초미세 구조물을 관찰할 수 있는 측정 장치이다. 이러한 전자를 소스로 사용하는 현미경에서 전자총의 특성을 파악하는 것은 전자현미경의 광학계를 설계하거나 그 성능을 평가할 때 매우 중요하다. 본 연구에서 제작한 전자총 평가 시스템은 전자총의 특성인 각전류밀도와 가상 전자원 크기를 측정할 수 있다. 이러한 특성을 정확하게 도출하기 위해서는 우선 가상 전자원의 위치를 알아야 한다. 전자총 평가 시스템은 전자총에서 방출된 전자빔을 형광 스크린에 조사하여 전자빔을 가시광선으로 변환하고, 형광 스크린 반대편에서 광학 현미경 렌즈가 장착된 카메라를 이용하여 빛으로 변환된 전자빔을 촬영하여 영상으로 획득 할 수 있다. 본 발표는 이렇게 획득한 영상에서 MathWorks(R)사의 MATLAB(R) 소프트웨어를 이용하여 물리적인 거리를 도출하기 위하여 사용하는 영상처리기법을 소개한다. 사용한 영상처리는 픽셀을 기반으로 계산하였으며, 취득 영상의 잡음을 제거하는 방법, 형광 스크린에서 획득한 전자빔에서 전자빔의 중심점 찾는 방법 및 이동한 전자빔의 거리를 계산하는 방법 등이 있다.

• Electrical & Electronic Materials
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• v.9 no.6
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• pp.616-625
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• 1996

본 고에서는 최첨단 주사형 마이크로프로브현미경의 최근동향에 대해 기술하고자 한다. SNOAM의 관찰분야에의 응용이라는 관점에서 광학소자, 반도체재료, 유기박막등의 미소영역에의 광학특성의 관찰이외에 생물분야에서는 형광표식한 시료의 형상상과 형광상의 대비에서 세포나 생체고분자의 기능 해명에도 이용 가능하다고 생각된다. 또한 광가공기술에의 응용이나 기억소자 기술에의 응용도 고려되어져 금후의 응용분야에의 발전이 기대된다. 다가오는 21세기 정보화사회에서는 분자.원자를 제어하는 기술이 중심기술이 될 것으로 확신되고 있다. 그러나 현재 우리주변 기술로서 분자. 원자를 단위로 하는 평가, 분석 기술은 거의 찾을 수 없다. 따라서 주사형 마이크로 프로브 현미경은 Nano-technology로서 장래 정보화사회에 중요한 평가.분석기술의 하나로서 정착될것으로 생각된다.

• Korean Chemical Engineering Research
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• v.51 no.2
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• pp.214-220
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• 2013

Hydrophobic coating on a silicate-based yellow phosphor ($Sr_2SiO_4:Eu^{2+}$) was carried out by using hexamethyldisiloxane (HMDSO) precursor in an atmospheric pressure dielectric barrier discharge plasma reactor, eventually to improve the long-term stability and reliability of the phosphor. The phosphor powder samples were characterized by a scanning electron microscope (SEM), a transmission electron microscope (TEM), a fluorescence spectrophotometer and a contact angle analyzer. After the coating was prepared, the contact angle of the phosphor powder increased to $133.0^{\circ}$ for water and to $140.5^{\circ}$ for glycerol, indicating that a hydrophobic layer was formed on its surface. The phosphor coated with HMDSO exhibited photoluminescence enhancement up to 7.8%. The SEM and TEM images of the phosphor powder revealed that the plasma coating led to a morphological change from grain-like structure to smooth surface with 31~46 nm thick hydrophobic layer. The light emitting diode (3528 1 chip LED) fabricated with the coated phosphor showed a substantial enhancement in the reliability under a special test condition at $85^{\circ}C$ and 85% relative humidity for 1,000 h (85/85 testing). The plasma-mediated method proposed in this work may be applicable to the formation of 3-dimensional coating layer on irregular-shaped phosphor powder, thereby improving the reliability.

• Clean Technology
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• v.19 no.3
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• pp.327-332
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• 2013

Space- and time-resolved in-situ optical and fluorescence microspectroscopy techniques have been applied to investigate the coke formation during aromatization of C5 paraffin and olefin over H-ZSM-5 crystal. In-situ UV/vis absorption measurement offers space- and time-resolved information for the coke formation. Different coking trends have been observed with respect to the location of a crystal as well as the reactant types. From in-situ confocal fluorescence microspectroscopy study, it is revealed that the concentration of certain species photo-excited at 488 nm becomes high at the central region, whereas the compounds emitting fluorescence by 561 nm laser move towards the boundary region of the crystal. The different fluorescence patterns obtained varying excitation lasers suggest the existence of distinct fluorescence emitting species having different degree of coke growth.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.424-424
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• 2013

Ce3+, Sm3+, Eu3+, Tb3+ 등 희토류를 도핑한 여러 종류의 형광체는 백색 LED (white light-emitting diode), 전계방출표시소자(field emission display), 플라즈마디스플레이패널(plasma display panel), 약물 운송(drug delivery) 등 다양한 분야에서 응용되고 있다. 최근에는 졸-겔 방법(sol-gel method)을 이용하여Y2SiO5, Y3-XGdxAl5O12, SrAl2O4 등 여러 종류의 호스트 물질을 합성하여 형광체의 특성을 분석하는 연구가 활발히 진행되고 있다. 이러한 졸-겔 방법은 비교적 낮은 온도에서 간단한 공정으로 좋은 균질성과 높은 생산성을 갖도록 형광체를 제작할 수 있는 장점을 가지고 있다. 이에 본 연구에서는 졸-겔 방법을 이용하여 BaGd2TiO13구조를 제작하였고, 이러한 구조적, 광학적 특성을 분석하기 위하여 열분석기(thermal analyzer), 전계방출형주사전자현미경(field emission scanning electron microscopy), 투과전자현미경(field emission transmission electron microscopy)을 이용하였다. 이러한 졸-겔 방법을 이용하여 제작한 BaGd2TiO13 구조의 형광체 적용 연구를 통한 디스플레이 및 백색 LED 응용에 유용할 것으로 기대된다.

• Journal of Korean Society of Forest Science
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• v.80 no.2
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• pp.232-236
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• 1991

The efficacy of berberine sulphate, a fluorochrome having binding properties with both DNA and RNA, was investigated for the detection of mycoplasma-like organisms(MLOs) in jujube(Zizyphus jujuba), paulownia(Paulownia tomentosa), mulberry(Morus alba) trees and periwinkle (Catharanthus roseus) plant. When examined under fluorescence microscope, berberine sulphate-stained sections of diseased samples showed distinct MLO-specific fluorescent particles in the phloem area, while such fluorescence was absent in the healthy ones. This staining technique was proved to be a very accurate method for the diagnosis of MLO infections in woody and herbaceous plants. Furthermore, the cheap and easy procedure could be used to test a great number of samples on MLO infections with reliability and rapidity.

• Journal of Life Science
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• v.12 no.3
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• pp.250-255
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• 2002

Fluorescent species-specific DNA probe (AT1) of toxic dinoflagellate Arexandrium tamarense was tested on several other species, on comparison of binding activity at different preservatives for fixation of the cells, at different culture age and estimation of cell density by light microscope or epifluorescent microscope using whole cell hybridization. Th AT1 probe specifically bound to Alexandrium tamarense, whereas it did not bind to other phytoplankton, in particular Alexandrium catenella, morphologically similar to Alexandrium tamarense, could not react to AT1 probe. When cells were fixed with all three preservatives, labeling cells of Alexandrium tamarense emitted strong fluorescent signal intensity. In addition, regardless culture days, binding activity with AT1 probe was strong. The tell densities estimated by epifluorescent microscope were than those estimated by light microscope. The enumeration and identifying of Arexandriurn tamarense using DNA probe method will be contributed to a new biotoxin monitoring and prediction system in field.