• Journal of Energy Engineering
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• v.17 no.4
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• pp.189-197
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• 2008

In this study, a system to measure continuously the fuel concentration in a steady flow rig on the basis of Rayleigh scattering is presented. The system can be employed to measure both the temporal and the spatial distribution. Also, it is possible to calibrate the system for the measurement of accurate absolute concentration. Firstly, the system was tested at a calibration chamber for the determination of scattering cross section from propane, butane, acetylene, Freon-12 and Genetron 143a. After this, the system was adapted to a steady flow rig to measure the temporal and spatial fuel concentration. The rig is composed of cylinder head, intake manifold, injector, and transparent cylinder which can simulate internal combustion engine. To cope with the interference of Mie scattering, which is main obstacle of the measuring concentration with Rayleigh scattering, a hardware filter was installed for reducing the number density of particles. Furthermore a software filter was developed, which is based on the rise time and the time constant of the photomultiplier-amplifier system. In addition, background noisy was reduced by adjusting the optical array and applying the pin hall and beam trap. The results show that LRS can provide useful information about concentration field and the software filter is very effective method to remove Mie interference.

• Journal of the korean academy of Pediatric Dentistry
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• v.46 no.2
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• pp.135-138
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• 2019

The aim of this study was to investigate the susceptibility of Mutans streptococci in both planktonic and biofilm states to erythrosine. S. mutans was cultured in brain-heart infusion (BHI) broth. Erythrosine was diluted in BHI broth and prepared at a concentration range of $0.02-10000{\mu}g/L$. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were measured using the microdilution method. After forming biofilms on 96-well plates, the minimum biofilm inhibitory concentration (MBIC) and minimum biofilm eradication concentration (MBEC) were measured. S. mutans was susceptible to erythrosine in both planktonic and biofilm states. MIC and MBC values were both $19.5{\mu}g/L$ for the planktonic state, while MBIC and MBEC values were $313{\mu}g/L$ and $2500{\mu}g/L$, respectively, for the biofilm state. Erythrosine ($19.5{\mu}g/L$) exhibited a bactericidal effect on S. mutans (killing 99.9%) in the planktonic state. For biofilms, erythrosine inhibited biofilm growth and eradicated 99.9% of biofilm bacteria at higher concentrations than MIC and MBC. These MBIC and MBEC concentrations are much lower than known noxious doses, and the MIC, MBC, and MBIC values were even lower than clinical concentrations.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 1999.10a
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• pp.317-318
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• 1999

바다의 오염은 하수에 의한 오염물질의 유입에 의해서 뿐만 아니라 대기를 통한 대기오염물질의 유입에 의해서도 이루어지게 되므로(홍기훈 등, 1997), 황해의 오염을 이해하기 위해서는 황해 대기 중 오염물질의 농도 특성과 그 이동 경로 등을 파악하여야 한다. 본 연구에서는 황해 대기 중 기체상 대기오염물질의 농도 특성과 그 배출원을 살펴보기 위해 인천에서 남서쪽으로 약 49 km 떨어져 있는 덕적도 측정소에서 1999년 4월 8일부터 9월 15일까지 오존(O$_3$)과 아황산가스(SO$_2$)를 측정하였다.(중략)

• KSBB Journal
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• v.16 no.6
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• pp.609-613
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• 2001

New protein-based biosensors using fluorescence for the detection heavy metal ions were developed. The detection range of heavy metal ions was between 10$\^$-3/ mM - 1 mM using casein and albumin as a transducer of biosensor, respectively. Casein showed better results for detecting heavy metal ions than albumin. Simple assay method was developed for the selective analysis of the two heavy metal ions by the fluorescence at wavelength of excitation and emission. This method was successfully applied to determining the concentrations Of Co$\^$2+/ and Fe$\^$3+/.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 1999.12a
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• pp.39-43
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• 1999

유역의 수질오염 평가는 GIS의 이용으로 더욱 발달되었는데 이 방법에서는 일반적으로 이용 할 수 있는 자료 즉, 소유역 구분도 및 하천망도, DEM, 강우자료, 유량측정지점 및 측정자료, 오염부하량 원단위자료, 수질측정자료, 토지이용자료, 점오염원(축산농가, 인구, 산업체)자료 등을 사용하여 유역에 대한 연간 평균 오염부하량과 오염농도를 계산할 수 있다. 본 연구에서는 장성과 광주 일부분을 유역으로 하는 황룡강 유역에 대해 GIS를 이용하여 수질오염을 평가하였다. 점오염원의 오염부하량은 수계 내에서 발생하는 점오염원의 위치를 기준으로 원단위를 적용하여 오염부하량을 구하였다 비점오염원 농도는 연평균 오염부하량을 총연간 누적유량으로 나눔으로써 계산하였다. 유역의 연평균 오염부하량에 대한 공간분포 그리드를 만들기 위해 각각의 그리드 셀에 대해 오염농도와 유출량을 곱한 값을 하류방향으로 누적하여 계산하였다. 이와 같은 방법을 사용하여 대상 유역에 대한 비점오염원 수질 농도의 예측치를 계산하였며, 이 예측치와 실측치를 비교 분석함으로서 개발된 모형을 검증하였다. 대상유역의 자료를 사용하여 황룡강 유역에 대한 개략적인 수질오염을 평가한 결과 BOD 유달율은 약 20%정도로 나타났다.

• Microbiology and Biotechnology Letters
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• v.16 no.5
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• pp.374-378
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• 1988

Treatability and maximum no inhibitory effect concentration of benzene were measured in the synthetic wastewater medium by the activated sludge in the continuous activated sludge reactor. The maximum no inhibitory effect concentration was 1, 600mg per liter. Benzene concentration over 500mg per liter inhibited the growth of microorganims by the measurment of E/BOD, and the treatability of benzene at the maximum no inhibitory effect concentration was over 95%.

• Proceedings of the KIEE Conference
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• 2007.04b
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• pp.125-127
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• 2007

본 논문에서는 세 가지 종류의 가스센서를 사용하여 수소가스에 대한 정량화 및 선택도를 향상시키기 위한 연구를 수행하였다. 여러 가지 수소가스 농도에 대한 각 가스센서들의 출력을 측정하였고 높은 출력과 분해능특성을 보이는 농도범위를 분석한 결과 세 가지 종류의 센서의 사용은 10,000ppm까지의 광대역의 수소 가스농도를 신뢰성 있게 측정할 수 있는 가능성을 보여주었다. 또한 어떠한 농도의 메탄(CH4) 및 일산화탄소에 대한 출력과 수소에 대한 출력을 비교한 결과 세 가지 센서의 출력을 조합하면 수소가스의 선택성을 향상시킬 수 있는 것으로 나타났다.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.451-451
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• 2018

박층류 자연정화공법은 수로의 폭을 넓히고 수심을 낮추어 박층류를 조성하고, 이를 이용하여 하천을 정화하는 공법이다. 박층류가 조성되면 낮은 수심에서 상대적으로 느린 유속 조건이 형성되며 이 때 박층부에 침전된 오염물질은 자갈층 표면에 형성된 생물막에 의해 산화 분해되어 제거된다. 박층류에 의한 오염물질 제거는 생물막의 형성, 생물 산화를 위한 용존산소량 등이 중요한 인자로 작용하며, 박층부를 조성하기 위해서는 수심 10 cm, 유속 30~50 cm/s 의 조건이 적절하다. 본 연구에서는 박층류에 의한 자연정화 성능을 평가하기 위하여 용인시 오산천 일부 구간 고수부지에 사석자갈을 이용한 박층류 자연정화공법이 적용된 차집수로를 설치하고, 오산천으로 유입되는 농수로의 물을 공급하여 오염물질의 농도 변화를 측정하였다. 측정된 항목은 T-N, T-P, COD, DO 등이며, 측정 결과 박층류 자연정화 수로를 유출부에서의 오염물질의 농도가 유입부에서보다 저감되는 것을 확인 할 수 있었다.

• Journal of the Korean Society of Marine Environment & Safety
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• v.21 no.4
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• pp.327-338
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• 2015

Because of impact on the underwater light field, CDOM can influence the accuracy of global satellite-based measurement of ocean chlorophyll and primary productivity. So we investigated the distribution and seasonal variation of CDOM in the East Sea during summer 2009 and 2011. Among them we report two distinctively different summer cases between 2009 and 2011 year, in which showed the different main sources for CDOM. Regulating factors and sources of CDOM in the East Sea were examined. Comparison between in situ and satellite derived Chl a and CDOM were made to find an influence of CDOM on measurement of satellite derived Chl a. Similar pattern and matching of MODIS Chl a with in situ Chl a 2009 was comparable, but significant discrepancy between MODIS Chl a and in situ Chl a was found, when CDOM was high in summer of 2011. GOCI data showed better matching with in situ data for both Chl a and CDOM, compared to MODIS data in summer of 2011. The presence of high CDOM at the surface layer supplied by vertical mixing seems to affect on the overestimation of Chl a by satellite data.

• The Korean Journal of Food And Nutrition
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• v.27 no.5
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• pp.751-759
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• 2014

In this study, we examined the hepatocyte toxicity and protective effects of an extract of Hericium erinacium cultivated with Artemisia capillaris (HEAC), and also examined the hepatocyte protective and antioxidative effects of a mixture of the HEAC and black garlic. At a concentrations of more than 0.05 mg/mL, the HEAC extract significantly reduced cell viability. The extract of HEAC treated with the same ratio of water and ethanol at $80^{\circ}C$ showed the highest hepatocyte protective effect. No significant difference in the hepatocyte protective effect was observed between the mixtures of HEAC with and without black garlic. In addition, higher antioxidative activity was shown with the addition of less black garlic. As a result of the sensory evaluation, a significant difference of sweetness was observed with varying liquid fructose concentration, but there were no significant differences in bitterness, flavor, thickness and overall acceptability according to the liquid fructose concentration.