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유럽표준분석기법(CEN methodology)을 적용한 원유 유출사고 감식 사례
한세훈(Sehun Han),장정훈(Junghun Jang),이우철(Woochul Lee),이찬근(Changeun Lee) 한국해양환경·에너지학회 2021 한국해양환경·에너지학회 학술대회논문집 Vol.2021 No.5
본 연구에서는 2021년 3월 4일 19:07경 울산 온산사거리 인근 하천에서 발생한 원유이송배관 파공으로 인한 원유 유출사고 관련 시료 감식 사례를 통해 원유(Crude Oil) 특성을 알아보고자 한다. 연구방법은 GC-FID 및 GC-MS를 활용한 유럽표준분석기법(CEN methodology)를 적용하여 원유 유출사고 시료 총 2점과 아라비안라이트(Arabian Light) 원유 샘플을 감식·분석하였다. GC-FID에 의한 포화탄화수소 비교 결과, 연구 대상 시료 모두 포화탄화수소 <sub>8<sub> ~ <sub>36</sub>가 검출되었고, 해상유출유와 비교시료의 포화탄화수소 피크 패턴 및 UCM(Unresolved Complex Mixture)의 형태, 풍화도 그래프(GC-PW-Plot), 판별지수 비교하여 모두 유사기준 이내임을 확인하였다. (그림-1) GC-MS에 의한 Biomarker 및 다환방향족탄화수소류(PAHs) 비교 결과, 물질 별 크로마토그램이 일치하며, 풍화도 그래프(MS-PW-plot), 판별지수(Diagnostic Ratios)도 유사기준 이내임을 확인하였고, C1-phenanthrenes(m/z 192)에서 MA(Methyl Antracene) 미검출 등 원유의 전형적인 특징과 황(Sulfur) 관련 PAHs인 C1-Dibenzothiophenes (m/z 198), C2-Dibenzothiphenes(m/z 212) 등이 높게 검출되어 고유황 원유임을 확인하였다. (그림-2) 최근 발생한 원유 유출사고 관련 시료를 유럽표준분석기법을 통해 감식·분석하여 원유의 특성 파악하고, 기존 보유중인 원유 샘플과도 비교하였다. 이는 앞으로 발생할 수 있는 원유유출사고에 대한 데이터베이스 축적 및 활용을 기대해본다. In this research, We want to find out the characteristics of crude oil through the sample identification related to the oil spill caused by the oil transfer pipe hole occurred in a river near Onsan Intersection in Ulsan on March 4, 2021 at 19:07. The methodology was applied with CEN methodology using GC-FID and GC-MS to identify two samples taken during the oil spill and Arabian Light samples. A comparison results of saturated hydrocarbons by GC-FID, All samples in the study are detected with saturated hydrocarbon <sub>8<sub> ~ <sub>36</sub>, and a comparison of the peak patterns of saturated hydrocarbon, UCM(Unresolved Complex Mixture), GC-PW-plot and Diagnostic Ratios on the Spill oil and comparison samples confirmed that they are all within similar criteria. (picture-1) A comparison results of Biomarker and PAHs by GC-MS, the chromatograms of each compounds are matched in the visual comparison, MS-PW-plot and Diagnostic also confirmed that they are all within similar criteria. Also, We identify typical characteristics of Crude Oil that MA(Methyl Antracene) is not detected in C1-phenanthrenes(m/z 192), and PAHs that related to Sulfur such as C1-Dibenzothiophenes(m/z 198) and C2-Dibenzothiphenes(m/z 212) are detected high. So it is means that they are high sulfur crude oil. (picture-2) We identify the characteristics of crude oil that spilled recently using CEN methodology and compare with existing crude oil. This is expected to accumulate and utilize databases for future spill crude oil.
HAN, Younggoo,SHIM, Woochul,KIM, Sehun The Institute of Electronics, Information and Comm 2009 IEICE TRANSACTIONS ON COMMUNICATIONS - Vol.92 No.4
<P>This study investigates subcarrier and power allocation schemes in an OFDMA downlink system. To consider client demands, a goal programming approach is proposed. The proposed algorithm minimizes the weighted sum of each client's dissatisfaction index. Simulations show that the sum of dissatisfaction indices can be reduced significantly.</P>
( Sehun Kim ),( Donghoon Han ),( Jae Hyuk Choi ),( Eun-joo Park ),( Dong Geum Shin ),( Min-kyung Kang ),( Seonghoon Choi ),( Namho Lee ),( Jung Rae Cho ) 대한내과학회 2021 The Korean Journal of Internal Medicine Vol.36 No.0
Background/Aims: Prolonged dual antiplatelet therapy (DAPT) with aspirin and clopidogrel beyond 1 year has been shown to reduce ischemic events at the expense of increased bleeding. However, limited data are available on the clinical significance of platelet reactivity (PR) at 1 year. Methods: We retrospectively identified 331 patients who underwent percutaneous coronary intervention (PCI) and assessed the on-clopidogrel PR using VerifyNow P2Y12 assay at 1 year in a single center. Two hundred eleven patients were on DAPT for > 1 year. The relationship between high on-treatment platelet reactivity (HPR) at 1 year and clinical outcomes beyond 1 year, as well as the longitudinal change in PR was analyzed. Results: At 1 year, 135 (64%) patients showed HPR and 76 (36%) did not. There was a significant increase in ischemic endpoint events, including cardiovascular death, non-fatal myocardial infarction, and stroke/transient ischemic attack in patients with compared to without HPR at 1 year (hazard ratio [HR], 2.68; 95% confidence interval [CI], 1.06 to 6.77; p = 0.036). However, the incidence of any Bleeding Academic Research Consortium bleeding was significantly lower in the HPR group (HR, 0.11; 95% CI, 0.02 to 0.65; p = 0.015). In the longitudinal analysis, PR significantly decreased from post-load to 1 year after index PCI in the non-HPR group. Conversely, the HPR group showed high PR from baseline through 1 year. Conclusions: HPR at 1 year may be a useful surrogate for predicting ischemic and bleeding events in patients on prolonged DAPT. Patients with and without HPR at 1 year showed different patterns of longitudinal change in PR.
Choi, Sehun,Seo, Han-Seok,Lee, Kwang Rag,Lee, Sunghee,Lee, Jihyun The Korean Society for Applied Biological Chemistr 2018 Applied Biological Chemistry (Appl Biol Chem) Vol.61 No.1
Volatile compounds in raw and cooked black rice (cv. Sintoheugmi) samples with different degrees of milling (step 0, 0%; step 1, 4.2%; and step 2, 10.5%, w/w) were investigated by headspace solid-phase microextraction and gas chromatography-mass spectrometry. A total of 101 volatile compounds were found. Among them, 44 compounds found in raw black rice were absent in cooked black rice and 20 compounds were newly formed in cooked black rice. The 8 identified major odor-active volatile compounds in raw and cooked black rice included 3 phenols (guaiacol, 4-vinylphenol, and 2-methoxy-4-vinylphenol), 2 benzenes (benzaldehyde and p-xylene), 2 furans (2-butylfuran and 2-pentylfuran), and 1 terpene (calamenene). Additionally, fatty acid oxidation products such as hexanal, 2-nonenal, octanal, and 2-pentylfuran were found in raw and cooked black rice samples. The relative concentrations of these volatile compounds were significantly higher in step 0 than in step 2 of raw and cooked black rice (p < 0.05). Partially milled cooked black rice (i.e., step 1) contained ~ 80% guaiacol (a favorable unique black rice flavor) of unpolished rice (step 0), with similar levels of several lipid oxidation indicator volatile products (e.g., 2-nonenal and 2-pentyl furan) of fully milled rice (step 2). Thus, partially milled black rice should be consumed rather than fully milled black rice.
Choi, Sehun,Seo, Han-Seok,Lee, Kwang Rag,Lee, Sunghee,Lee, Junyoung,Lee, Jihyun Elsevier 2019 Food chemistry Vol.276 No.-
<P><B>Abstract</B></P> <P>Although black rice has gained popularity, the changes in volatiles produced during black rice storage remain unclear. Herein, the volatile composition of unmilled and milled black rice stored at 25 °C or 35 °C for 0–12 months was investigated by headspace solid-phase microextraction with gas chromatography–mass spectrometry. Fifty-four volatiles were identified, 15 of which were not previously identified in black rice, including 4-propylbenzaldehyde, methyl 2-hydroxybenzoate, methyl 2-methylpentanoate, 2,5-dimethylnonane, 5-methyldecane, and 2-methylundecane. In this study, octanal increased at a high rate during early storage compared with hexanal, a traditional oxidation marker; thus, octanal may be an early oxidation marker in black rice. The results suggested that high temperature is not appropriate for storage of unmilled or milled black rice because it promotes lipid oxidation, producing volatile compounds. At 25 °C, black rice stored for short times such as 3 months should be milled, whereas for 6 months, black rice should be stored without milling.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The volatiles of black rice stored at 25 °C or 35 °C for 0–12 months was investigated. </LI> <LI> A total of 54 volatiles were identified in fresh and in stored black rice. </LI> <LI> With few exceptions (e.g., guaiacol) most volatiles increased during storage. </LI> <LI> Significant increases were related to the development of lipid oxidation. </LI> </UL> </P>
Donghoon Han,Sehun Kim,Sang Jun Park,Jae Hyuk Choi 순천향대학교 순천향의학연구소 2018 Journal of Soonchunhyang Medical Science Vol.24 No.2
Morbidity and mortality rates associated with acute myocardial infarction accompanying chronic total occlusion are comparatively high. European guidelines recommend primary intervention for the causative lesion in patient with acute myocardial infarction. Therefore, it is important to identify the culprit lesion. We report two cases of myocardial infarction with concurrent chronic total occlusion in an emergency setting.
Choi, Sehun,Seo, Han-Seok,Lee, Kwang Rag,Lee, Sunghee,Lee, Jihyun The Korean Society for Applied Biological Chemistr 2018 Applied Biological Chemistry (Appl Biol Chem) Vol.61 No.1
Six black rice cultivars (Heukjinju, Sintoheugmi, Heukhyangchal 1, Bosukheukchal, Sinnongheukchal, and Josengheukchal) and varying milling degrees (step 0, 0%; step 1, 4.2%; and step 2, 10.5%, w/w) were used to evaluate the effects of cultivars and milling degrees of black rice (Oryza sativa L.) on the total phenolic contents (TPC), total flavonoid contents (TFC), antioxidant activity (2,2-diphenyl-1-picrylhydrazyl free radical assay), and phenolic composition in free and bound phenolic fractions. Unpolished (step 0) Sintoheugmi showed significantly higher TPC, TFC, antioxidant activity, phenolic acid levels, and anthocyanin levels than other unpolished cultivars (p < 0.05). As milling degree increased, TPC, TFC, antioxidant activity, phenolic acid levels, and anthocyanin levels decreased significantly (p < 0.05). TPC, TFC, and antioxidant activity were significantly higher in free phenolic fractions than bound phenolic fractions of black rice extracts, regardless of cultivars (p < 0.05). The major phenolic acid was ferulic acid, and the major anthocyanin found in free phenolic fractions in black rice samples was cyanidin-3-O-glucoside. The sum of individual phenolic acid levels ($255.2{\pm}0.0{\mu}g/g$) and the sum of anthocyanins levels ($831.4{\pm}0.3{\mu}g/g$) were significantly higher in Sintoheugmi black rice than in the other cultivars for step 0 (unpolished rice) (p < 0.05). For step 1 and step 2, Heukjinju black rice contained significantly higher sum of phenolic acid levels and sum of anthocyanin levels than the other cultivars (p < 0.05). For use as a better functional ingredient, it is, therefore, important to consider different milling degrees together with different black rice cultivars having the highest antioxidant component.