• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.222.1-222.1
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• 2012

JEM-EUSO (Extreme Universe Space Observatory on-board the Japanese Experiment Module)는 국제우주정거장(International Space Station)의 일본 실험 모듈인 'KIBO'에 우주 망원경을 설치하여, 100 EeV이상의 초고에너지 우주선 관측을 수행함으로써, 초고에너지의 스펙트럼, 구성성분과 기원을 연구하는 국제공동연구 프로젝트이다. 구경 2.5 m로 60도의 광시야각을 가지는 대형 굴절 망원경을 통해서, 지구 대기에 우주선 shower로부터 발생한 형광 신호를 관측하려고 한다. 이 프로젝트는 2016~2017년에 발사되어, 5년 이상의 임무 수행을 목표로 하고 있으며, 그 전단계로 Prototype 시스템을 가지고 지상실험인 EUSO-TA와 고도 40 km에서 수행할 EUSO-Balloon실험을 준비하고 있다. 먼저, 망원경의 prototype을 2012년 12월쯤 미국 유타에 있는 Telescope Array(TA) 실험에 설치하여 우주선 또는 임의로 인가한 광원에 의해서 생성된 shower를 TA의 Fluorescence Detector와 함께 측정하여, 시스템 calibration과 더불어 지상에 검출된 우주선을 연구할 계획이다. 그 이듬해인 2013년 여름에는 Balloon에 망원경의 Engineering model을 실어서, 대기고도 40 km아래에서 우주선에 의해 생성되는 shower를 개발한 트리거 시스템을 통해서 검출하고, 대기권에 존재하는 UV background 광원들을 측정하여 우주선을 연구할 예정이다. 한국 그룹은 JEM-EUSO을 위해서 개발한 디지털 신호처리 및 트리거 장치의 제작 중에 있으며, 위의 실험들을 위해 망원경과 함께 조립하여 테스트를 수행할 계획이다.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.271.1-271.1
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• 2013

Titania is usually used in sun-screens, tooth paste, and other daily used objects as a pigment. However, scientists have focused on titania as photocatalyst due to its excellent activities. By fabricating vanadium doped TiO2 and CuOx co-catalyzed TiO2 nano-size filter, the degradation level of the volatile organic compound (VOC) concentration was tested using 365nm UV LED as light source in a closed chamber. Main purpose for this test is to evaluate the activities of various catalysts for degrading the VOCs which are detrimental to human body and toluene and p-xylene were chosen in the VOC removal test. Target gas materials were injected into the test chamber with dry air as carrier gas which was flowed into the gas washer bottle filled with liquid form of VOC substance. When the VOC gas flows into the chamber, it is circulated by 200 mm fan in order to contact with the set-up filter on the aluminum holder. Target gas concentration in the chamber was monitored using VOC detector (miniRae3000, Raesystems) which was also placed inside the chamber. With the measured concentration, the VOC degradation efficiency and the degradation rate were evaluated and used to compare the catalytic activities.

• Journal of Food Hygiene and Safety
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• v.3 no.4
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• pp.203-209
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• 1988

This study was performed to develop the simple and rapid determination method of preservatives in Yogurt and Soybean.sauce. 1. The analytical method by HPLC system was as follow: The sample was diluted, centrifuged, filtered, if necessary, and analyzed by HPLC system with UV detector. 2. The analytical method by GLC system was as follow: The sample was extracted directly with ether, added cone. sulfuric acid to destroy emulsion and analyzed by the GLC system with FID. 3. The recovery rates of preservatives by the above methods were higher than 99.0 %. 4. Total running time for the above methods was less than 50 minutes. Especially, the running time for dilution method by HPLC system was one-third of that for GLC method.

• Proceedings of the KAIS Fall Conference
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• 2003.06a
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• pp.307-310
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• 2003

In order to analyze the concentration of cetylpyridinium chloride(CPC), a widely used cationic surfactant, we developed a simple and compact spectrometer, which consisted of a diode laser and a photodiode detector. Preliminary results are described here on the performances of the system in terms if the stability of output intensity, sensitivity, and reproducibility. Data on the comparisons of the system with the conventional UV-VIS spectrometer are also given. With the instrument, the concentration of CPC between 3${\times}$10$\^$-5/M and 1.1${\times}$ 10$\^$-4/M are calibrated as a correlation coefficient of 0.9635. The results shown here indicate a potential for developing a portable spectrometer useful for analyzing concentrations of CPC.

• Transactions of the Society of Information Storage Systems
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• v.2 no.1
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• pp.79-84
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• 2006

The next generation of optical storage systems requires higher numerical aperture(NA) objective lenses and shorter wavelength laser in order to improve the unit areal density. A blu-ray technology satisfies a miniaturization and a high capacity which are the requirements of the portable device. In this paper, we analyze the optical performance of hybrid micro lens and do active alignment. The hybrid micro lens is manufactured by using a wafer based fabrication technology. Optical components of hybrid micro lens are evaluated. The measurement of the optical power, the spot size and the wavefront error are performed to evaluate the hybrid micro lens with NA 0.85. Using the measured data, we estimate if the performance of hybrid micro lens corresponds to the designed performance. After the performance of hybrid micro lens is evaluated. the integrated optical pickup and the hybrid micro lens are assembled by active alignment using UV curing and the optical performance of SFFOP is satisfied with BD specifications.

• Journal of Environmental Science International
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• v.14 no.4
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• pp.445-449
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• 2005

A simple and sensitive analytical method based on RP-HPLC with UV detector$(225{\cal}nm)$ and mobile phases using $0.1{\%}$ phosphoric acid and acetonitrile was developed for simultaneous determination of quinclorac, bentazone, 2,4-D, bensulfuron-methyl, dymuron, capropamide, pencycuron, ethofenprox. This method was resulted in recovery of $78{\~}96{\%}$ with RSD $3.3{\~}7.5{\%}$, LODs $0.12{\~}0.84$ and LOQs $0.34{\~}1.20{\cal}mg/L$. Calibration curves were linear with r of $0.9995{\~}0.9999$.

• YAKHAK HOEJI
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• v.48 no.5
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• pp.278-284
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• 2004

In order to determine the bioavailability of c1onazepam, an anxiolytic drug, a simple, rapid and sensitive HPLC analysis was developed in healthy Korean volunteers. The analysis system was validated in specificity, accuracy, precision and linearity. The analysis condition we established was 2.58 min and 5 ng/$m\ell$ in retention time and limit of quantitation of c1onazepam, respectively, using reverse-phase C18 column connected to UV detector. Quantitation was performed at 235 nm wave length with p-hydroxybenzoic acid ethyl ester as internal standard. The method involved a simple extraction. In order to study blood level profiles as a function of time, eight volunteers were enrolled and orally took 6 mg clonazepam once. The blood samples were collected from 0 to 120 h after the drug administration. Mean AUC and Cmax value were 1028.17$\pm$568.165 (ng/$m\ell$$.$hr) and 41.25$\pm$10.82 (ng/$m\ell$), respectively. And mean Tmax and T$_{1}$2/ value were 1.08$\pm$0.42 (hr) and 30.78$\pm$3.26 (hr). From the results we determine the pharmacokinetic characteristics of clonazepam in Korean people using a newly developed and useful HPLC method.

• YAKHAK HOEJI
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• v.48 no.5
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• pp.297-302
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• 2004

The purpose of the present study was to evaluate the bioequivalence of two cimetidine tablets, Tagamet (Yuhan Pharm. Co., Ltd.) and Nex (Bi-nex Pharm. Co., Ltd.), according to the guidelines of Korea Food and Drug Administration (KFDA). The cimetidine release from the two cimetidine tablets in vitro was tested using KP Apparatus I method with various dissolution media (pH 1.2, 4.0, 6.8 buffer solutions and water). The dissolution profiles of two cimetidine tablets were very similar at all dissolution media. Twenty four healthy male volunteers were divided into two groups with a randomized $2{\times}2$ cross-over study. After four tablets (800 mg cimetidine) were orally administrated, blood was taken and the concentrations of cimetidine in serum were determined using HPLC with UV detector. The pharmacokinetic parameters such as $AUC_{t}$, $C_{max}$ and $T_{max}$ were determined. The result showed that the differences in $AUC_{t}$, and $C_{max}$ between two cimetidine tablets based on the Tagamet were -6.82% and -12.98%, respectively. There were no sequence effects between two tablets in these parameters. The 90% confidence intervals using logarithmically transformed data were within the acceptance range of log(0.8) to log(1.25) (e.g., log(0.90)log(0.97) and log(0.82)log(0.93) for $AUC_{t}$ and $C_{max}$, respectively), indicating that Thrumetin tablet was bioequivalent to Tagamet tablet.

• Archives of Pharmacal Research
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• v.11 no.2
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• pp.134-138
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• 1988

Urine measurements by MNR were made for 25 persons including cancer and non-cancer patients. The aromatic proton signals of NMR wer observed much more often in cancer patients' urine than non-cancer patients' one. To compare the amount of the phenolic compounds excreted in urine between cancer and non-cancer patient, urine analysis by HPLC with UV detector was performed. Total peak area and major peak areas of cancer patients' urine wer emuch greater than those of non-cancer patients' one. To check the phenolic compound excreted in urine, a new jellied reagent named Gift reagent which was based on Millon's reagent, was developed for urine color reaction. When the reagent was tested, the sensitivity and specificity for urine samples of 69 persons including cancer and non-cancer patients were measured by 85.3% and 91.4%, respectively, indicating that the Gift reagent afford a possibility of cancer diagnosis.

• Natural Product Sciences
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• v.25 no.2
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• pp.111-114
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• 2019

The herbal formula, DF-02, consisting of Ephedra intermedia and Rheum palmatum are used for the treatment of the metabolic diseases such as obesity and liver fibrosis in Korean local clinics. We aimed to develop the simultaneous analytical conditions for four standards, (+)-pseudoephedrine (PSEP) and (-)-ephedrine (EP) for E. intermedia, and aloe-emodin (AE) and chrysophanol (CP) for R. palmatum using HPLC-UV techniques. The validated conditions yielded the high precision (relative standard deviation (RSD) < 3.65%) and the recoveries (94 - 106%) using the calibration curves with high linearity ($R^2$ > 0.9994). As a result, four standards of DF-02 were simultaneously determined under the developed method, which will be utilized for the quality control or evaluation of DF-02 and many herbal preparations containing E. intermedia and R. palmatum.