• Journal of Korean Society of Environmental Engineers
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• v.29 no.5
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• pp.540-547
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• 2007

Humic substances(HS) from Han River water was physic-chemically isolated by fractionational methods to investigate the seasonal distribution and to characterize the properties compared with intrinsic humic materials. Various HS samples were analyzed by element, Fourier transform infrared(FT-IR), proton nuclear magnetic resonance$(^1H-NMR)$ and fluorescence analyzers. The portion of HS from Han River water(HRHS) was 47.0% on the average, however it appeared that rainfall event brought about higher fraction of HS in Han River water by the periodic investigation. Aromaticity and humification degree of the HRHS were relatively lower than those of intrinsic humic materials originated from decomposing vegetation. FT-IR, $^1H-NMR$ and fluorescence spectroscopy showed the distinct differences between HRHS and intrinsic humic materials. Commercial humic materials could not represent structural and functional characteristics of local HS. The fluorescence spectroscopy, a relatively simple measurement, was found most useful tool to estimate humification degree for humic materials from particular sources.

• Korean Journal of Materials Research
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• v.8 no.7
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• pp.601-606
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• 1998

The $SrTi0_3$:Al, Pr red phosphors were prepared by solid state reaction method. Phosphor preparation parameters such as sintering temperature and time were optimized for the photoluminescence(PU intensity and the cathodoluminescence(CL) intensity. Powder samples showed the characteristic X-ray diffraction patterns of the perovskite structure and the average particle size of 3~5/$\mu\textrm{m}$ for particle size distribution(PSD) analysis. Also, scanning electron microscopy for the powder samples showed that the particles are reasonably crystallized with spherical shape. Especially, higher low voltage CL properties of $SrTi0_3$:Al, Pr phosphors than commercial $Y_2O_3$:Eu phosphors are expected to be applied for a low voltage field emission display(FED).

• Journal of the Korean Society of Radiology
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• v.9 no.1
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• pp.39-45
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• 2015

$La_2W_3O_{12}:Eu^{3+}$ phosphors were prepared by solid state reaction method. The crystal structure was characterized by XRD pattern and ICSD card (78180). Luminescence properties of $La_2W_3O_{12}:Eu^{3+}$ are investigated by optical and laser-excitation spectroscopy in which emission and excitation spectra and time-resolved spectra are measured. The 1 mol % $Eu^{3+}$-doped $La_2W_3O_{12}$ phosphor exhibits broad excitation band peaking at 286 nm due to the ligand-to-metal charge transfer transition. The excitation lines due to the $^7F_0{\rightarrow}{^5D_4},{^5D_4},{^5L_6},{^5G_4},{^5D_3},{^5D_2}$ transitions of $Eu^{3+}$ are observed in the wavelength region 350-500 nm. The strong line emission is observed at 618 nm corresponding to the due to the $^5D_0{\rightarrow}^7F_2$ transition. The lifetime of 618 nm emission decreases with increasing temperature as 7 K ($114{\mu}s$), 100 K ($94{\mu}s$), 200 K ($10{\mu}s$) and 300 K ($0.5{\mu}s$).

• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.4
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• pp.611-619
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• 2005

The aim of this study was to apply the quantitative light-induced fluorescence(QLF) and use of fluorescein-enhanced QLF method for quantitative assessment of early enamel demineralization in vitro, comparing effectiveness of light sources : argon laser, halogen lamp, light emitting diode (LED) and plasma arc lamp. Sixty extracted teeth were used, prepared by gentle pumicing and coating in an acid-resistant nail-varnish, except for an exposure to a demineralizing solution. Teeth were removed at regular intervals (24, 48 and 72hrs), air-dried and QLF image were taken. Mineral loss, as measured by difference of optical density, was recorded. For dyeenhanced QLF a 0.075% sodium fluorescein dye was applied after QLF examination and mineral loss was recorded. The following result were obtained : 1. Comparing with mean difference of optical density, plasma arc lamp was higher than other light sources in all group (p<0.05). 2. Comparing each group with mean difference of optical density, there was significant different using plasma are lamp and halogen lamp. 3. For use of dye-enhanced QLF, comparing with mean difference of optical density, plasma arc lamp were higher than other light sources in all group(p<0.05). 4. With this model dye-enhanced QLF compared with QLF in optical density, dye-enhanced QLF was higher than QLF in optical density. From the results presented in this paper, it was concluded that plasma light source was more effective compared with other light source for the detection and the quantification of early enamel caries.

• Analytical Science and Technology
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• v.11 no.6
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• pp.474-477
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• 1998

A simple and rapid method for preparation of standard phosphatidylcholine hydroperoxide (PCOOH) in chemiluminescence-HPLC assay (CL-HPLC) was developed using the rose bengal dependent spectrofluorometric oxidation. The concentration of obtained PCOOH was determined by FOX (ferrous oxidation-xylenol orange) assay and then subjected to a CL-HPLC system.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2005.04a
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• pp.233-239
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• 2005

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.43 no.4 s.310
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• pp.11-20
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• 2006

This paper presents a method for detecting tumors on chicken carcasses by fusion of hyperspectral fluorescence and reflectance images. Classification of normal skin and tumor is performed by the image obtain 어 from optimal band ratio which minimizes the overlapping area of PDFs for normal skin and tumor. This method yields four feature images, each of them represents the ratio of two intensity values from a pixel. Classification is achieved by applying ISODATA to each pixel from the feature images. For the analysis of reflectance image, band selection method is proposed based on the information quantity, many effective features are acquired for the classification by defining the linear transformation selecting the projection axis, accordingly, accurate interpretation of images is possible in the reflectance image and automatic feature selection method is realized. Feature images from reflectance images are also classified by ISODATA and combined with the result from fluorescence images. Experimental result indicates that improved performance in term of reducing false detection rate is observed.

• Journal of Embryo Transfer
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• v.14 no.1
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• pp.3-5
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• 1999

이식 전 수정란의 성판정은 많은 축산인의 소망이었다. 많은 방법이 제기되었지만, 세포유전학적 분석방법은 ET의 상용화에 거의 무의미할 정도로 한계가 많았고, 이후 개발된 응성 특이적 항원이나 X-염색체에서 발현되는 효소의 활동을 통한 성판정 방법은 흥미롭기는 하나 산업적 적용에 제약이 많았다. 80년대 중반 Y-염색체 특이적인 DNA 탐침자의 개발과 PCR을 통한 DNA증폭기술의 개발은 수정란 성판정을 획기적으로 개선시켰다. DNA기술을 통한 수정란의 성판정은 분자생물학을 현장으로 진출시킨 첫 경우이기도 했다. 90년대에 세포유전학적 분석에서 FISH가 소개되었으며, 염색체 특이적 library는 다른 기초적이고 응용세포유전학적 연구에 유용한 도구가 되었다. 최근에는 사람에서는 착상전 수정란의 성판별 및 유전진단을 위해 실시되고 있는 형광직접접합법(fluorescent in situ hybridization, FISH)은 효소적 유전자 증폭(polymerase chain reaction; PCR)에 비해 높은 민감도와 정확성을 보이고 있으나 hybridization 및 washing 과정에 매우 긴 시간이 소요되고, 절차도 까다로워 현장에서의 적용이 용이치 않았다. 그러나 direct labelled probe의 이용, heat programmable instrument의 개발, denaturing chemical의 사용배제 등을 통해 소요시간 및 절차의 대폭적인 간소화를 이루어 현장의 적용 가능성을 한층 높이고 있다. 현재 사람의 세포유전학 및 종양학에서는 FISH의 다양한 기술이 많이 이용하고 있으나 소에서는 탐침자(probe)가 개발되어 있지 않아 그 이용이 미미하다. 본 연구는 FISH를 이용하기 위한 탐침자의 개발을 궁극적인 목표로 삼았으며, 이를 위해 접근이 용이한 방식을 개발하여 기존의 방식과는 다른 소 배아세포의 성을 판별 할 수 있는 접근방법을 소개 하고자한다.

• Analytical Science and Technology
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• v.24 no.1
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• pp.45-50
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• 2011

While the crime scene investigation, evidences are found to search with the naked eyes and to use science equipments. Crime evidences, which are used as judgement, have various things: blood, sperm, saliva, hair, fingerprint, fiber, soil, paint, and so on, especially, fingerprints could take through crime scene investigation, and in there, it could distinguish individually. In this case study, sort of leathers: a wallet, a belt, and a sofa, which are needed special identification even thought people experience easily in usual day, are tried many of the identification tests. As a result, using fluorescent magnetic powder method or fluorescent powder method as identification of many leathers is most efficient.

• Analytical Science and Technology
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• v.9 no.2
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• pp.198-202
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• 1996

A rapid and simple method for the determination of histamine by reverse-phase high performance liquid chromatography with fluorescence detection was established. 9-Fluorenylmethyl chloroformate(FMOC) was used as fluorescent derivative reagent. The optimum conditions for the derivatization such as pH, reaction time and the concentration of FMOC were investigated. Linearity of calibration curve was obtained between $0.1{\mu}g/ml$ and $0.5{\mu}g/ml$(r=0.992) and the limit of detection was $0.01{\mu}g/ml$.