• 분석과학
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• 제20권2호
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• pp.170-175
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• 2007

올리브유중 벤조피렌을 분석하기 위하여 고속액체크로마토그래피/형광검출기를 이용하였다. 시료의 지방성분을 헥산으로 제거한 후 N,N-DMF 수용액을 다시 헥산으로 추출하여 후로리실 SPE 카트리지로 정제한 후 기기분석하였다. 이동상으로는 아세토니트릴과 물의 혼합용액(8:2)을 사용하였으며 형광검출기의 여기파장은 294 nm이었고 형광파장은 404 nm이었다. 평균 회수율은 95%이었으며, 정량한계는 $0.9{\mu}g/kg$이었다. 대상 식품인 올리브유 중 벤조피렌의 검출수준은 불검출~$1.9\mu}g/kg$이었으나, 식품공전의 기준인 올리브유중 벤조피렌의 최대수준 $2.0{\mu}g/kg$이하이었다.

• Journal of Radiation Protection and Research
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• 제33권1호
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• pp.35-40
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• 2008

석유화학 공정의 증류탑은 공정유체를 분리, 정제하는 중요한 장치 중의 하나로 가동효율은 설비의 생산성에 큰 영향을 미친다. 본 연구는 밀봉 감마선원을 이용하여 투과 감마선의 세기를 높이별로 측정함으로써 내부 밀도의 변화를 분석하여 공정의 가동 중 내부 상황에 대한 정보를 얻고자 하였다. 이를 위하여 한국원자력연구원에서 개발된 자동 증류탑 검사장치를 이용하여 증류탑 상부 양쪽에 밀봉 감마선원과 방사선검출기를 매달아 수직으로 내리면서 실험을 수행하였으며, 이때 감마선원으로는 Co-60 150 mCi과 방사선검출기로 BGO detector를 각각 사용하였다. 진단결과 설비 내부의 tray에는 구조적 결함이 관찰되지 않았으나, 유체분포를 고려할 때 상부는 기포층(vapor)의 밀도분포가 지배적인 반면에, 하단부에는 기포에 비해 유체가 상대적으로 많이 분포하는 것으로 계측되었다. 본 실험으로부터 밀봉 감마선원을 이용한 가동 중에 있는 대형 증류탑의 tray에 대한 구조적 건전성 및 내부 유체분포에 대한 정보를 성공적으로 제시하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 C
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• pp.1848-1850
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• 2004

변압기에 사용되는 절연유의 열화정도를 변압기의 운전정지 없이 실시간으로 측정할 수 있는 전기용량을 이용한 센서를 개발하였다. 개발된 전기용량형 센서는 3-전극형의 구조와 변압기에 센서의 외부상자가 접지 될 때 2중의 정전차폐가 되도록 하여 외부로부터의 잡음에 영향을 받지 않도록 하였다. 또한 변압기에서 절연유의 온도변화에 따른 유전율 변화를 보상하기위하여 기준용 센서와 측정용 센서를 한개의 변압기에 장착함으로 온도보상이 되도록 하였다. 제작된 센서는 변압기에서 절연유의 사용기간에 따른 유전율의 변화를 정확히 측정하였으며, 절연유의 체적저항의 변화도 감지 할 수가 있다. 따라서 센서에서 출력되는 신호를 phase sensitive detector를 사용하여 유전율의 변화로 혹은 체적저항의 변화로도 나타내 보일 수가 있다.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2002년도 proceedings of the second asia international conference on tribology
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• pp.465-466
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• 2002

In any mechanical system consisting of gears, shafts and/or bearings, the majority of metallic particles deposited into and carried by the lubrication system originate from the deterioration of oil-wetted working surfaces, even in proper lubrication system, due to failure mechanism (s) such as wear, fatigue and fretting corrosion. Determination of the point at which transition from normal to abnormal or to actual damage occurs has become a focus of attention in research activities for years, because it has been recognized that reliable, economic operation can be achieved through appropriate preventative measures. Known collectively from 'all size wear debris analysis' as early failure detection, the methods of testing for damage differ considerably, range from a micron or a submicron size debris analysis to Magnetic Chip Detector (MCD) ferrous debris analysis. This paper will be focused on the utilization of the low-cost analysis techniques for evaluation of industrial machinery condition.

• 한국응용과학기술학회지
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• 제23권1호
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• pp.70-76
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• 2006

The influence of fluorophor, scatterer, absorber in turbid materials by light scattering were interpreted for the scattered fluorescence intensity and wavelength, it is studied the molecular property by laser induced fluorescence spectroscopy. It can be found that the effects of optical property are penentrated in scattering media by the optical $parameters({\mu}s$, ${\mu}a$, ${\mu}t$, ${\gamma}$, ${\rho})$. The value of scattering coefficient ${\mu}s$ is large appeared by means of the increasing particles of scattering, it can be found that the slope appears exponentially as a function of distance from laser source to detector. It may also utilize in designing the best model for oil chemistry, laser medicine and application of medical engineering.

• 한국조명전기설비학회지:조명전기설비
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• 제6권4호
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• pp.53-59
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• 1992

This paper describes an instrument for the detection and geometric location of partial discharge (PD) source in transformers. This instrument measures electric current pulses and ultrasonic pulses simultaneously, counts the number of electrical pulses and determines the geometric location of PD in transformers. It was found that there is a relationship between partial discharge magnitude and pulse repetition rate when the applied test voltage and oil temperature were varied. Through the laboratory test using model transformer, it was clarified that this detector could be used for detecting and locating PD in the transformer.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1990년도 하계학술대회 논문집
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• pp.279-282
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• 1990

This paper describes an nstrument for the detection and geometric location of partial discharge(PD) sources in transformers. This instrument measures electric current pulses and ultrasonic pulses simultaneously, counts the number of electrical pulse and determines the geometric location of PD in transformers. It was found that there is a relationship between partial discharge magnitude and pulse repetition rate when the applied test voltage and oil temperature were varied. Through the laboratory test using model transformer, it was clarified that this detector could be used, satisfactory for detecting and locating of PD in the transformer.

• 한국응용과학기술학회지
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• 제12권2호
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• pp.151-156
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• 1995

The influences of fluorophor, scatterer, absorber in turbid material by light scattering were interpreted for the scattered fluorescence intensity and wavelength, it has been studied the molecular properties by laser induced fluorescence spectroscopy. It has been found that the effects of optical properties in scattering media by the optical parameters(${\mu}_{s}$, ${\mu}_{a}$, ${\mu}_{t}$). The value of scattering coefficient ${\mu}_{s}$ is large by means of the increasing particles of scatterer, it has been found that the slope decays exponentially as a function of distance from laser source to detector. It may also aid in designing the best model for oil chemistry, laser medicine and application of medical engineering.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 C
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• pp.2126-2128
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• 2005

In this paper, it was investigated the applicability of TF analysis for the discrimination of air corona in on-site PD measurement. For the purpose, single and multiple discharges combined with oil discharges and air corona were generated and measured by use of artificial models and HFPD pulse detector. Through the TF analysis, data clusters could be classified each other in the TF Map, even in the case of multiple discharges. Therefore, it is known that TF analysis could be applied for the improvement of on-site PD measurement.

• Journal of Applied Biological Chemistry
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• 제51권1호
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• pp.20-27
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• 2008

The contents of lignan, protein, and oil of nine Sesamum indicum cultivars were analyzed. To determine the lignan contents, sesamin 1 and sesamolin 2 were isolated from the ethylacetate extracts of the Suwon cultivar, and the structures were fully characterized by spectral and physical methods. The seeds of nine cultivars were screened for two lignans, which were determined by HPLC using a $C_{18}$ reversed phase column coupled with a photodiode array detector. Suwon cultivar showed the highest concentration (1: $6.24{\pm}0.04$ and 2: $3.58{\pm}0.01\;mg/g$), whereas Soonheuk displayed the lowest (1: $0.91{\pm}0.01$ and 2: $0.73{\pm}0.01\;mg/g$). The average content ratio of sesamin 1 (3.64 mg/g) was significantly higher than that of sesamolin 2 (2.57 mg/g). The protein content ranged from $21.52{\pm}0.35$ to $31.22{\pm}0.25%$, Suwon containing the highest level and Soonheuk had the lowest. Kwangbaek showed the highest oil level ($49.84{\pm}0.40%$), while Soonheuk exhibited the lowest ($42.52{\pm}0.05%$). Sesamin 1 exhibited a stronger radical-scavenging activity in the ABTS ($IC_{50}:\;63.2{\pm}2.4\;{\mu}M$) than its DPPH radical-scavenging activity ($IC_{50}>200\;{\mu}M$). These results lead to the conclusion that lignan content is affected by protein and oil contents. Concentration of the chemical components in the cultivars could be a key factor in the selection process of a high quality species.