• Bulletin of the Korean Chemical Society
• /
• 제25권4호
• /
• pp.549-552
• /
• 2004

A sensitive, selective and rapid method has been developed for the determination of mercury based on the rapid reaction of mercury(II) with p-sulfobenzylidenethiorhodanine (SBDTR) and the solid phase extraction of the colored chelate with $C_{18}$ disks. In the presence of pH 3.5 sodium acetate-acetic acid buffer solution and Emulsifier-OP medium, SBDTR reacts with mercury(II) to form a red chelate of a molar ratio 1 : 2 (mercury to SBDTR). This chelate was prconcentrated by solid phase extraction with $C_{18}$ disks. An enrichment factor of 50 was achieved. The molar absorptivity of the chelate is $1.28{\times}10^5 L{\cdot}mol^{-1}{\cdot}cm^{-1}$ at 545 nm in measured solution. Beer's law is obeyed in the range of 0.01-3 ${\mu}$g/mL. The relative standard deviation for eleven replicates sample of 0.01 ${\mu}$g/mL is 1.65%. This method was applied to the determination of mercury in tobacco and tobacco additive with good results.

• Composites Research
• /
• 제13권6호
• /
• pp.63-72
• /
• 2000

본 논문에서는 평직복합재료의 섬유다발의 배열 및 적층수가 등가물성치에 미치는 영향을 연구하였다. 임의로 적층된 2~32장의 평직복합재료 구조물의 단위구조를 모델링 하였고, 단위구조의 외부 경계 면에는 반복 경계조건을 가하였다. 등가물성치는 일축 인장시험 및 전단시험을 수치적으로 모사하여 계산하였고, 섬유다발 위상차의 무작위적 특성은 표본해석을 통해 고려하였다. 계산 된 등가물성치의 통계처리 결과, 두께가 얇은 평직복합재료의 $E_{xx}$와 $V_{xy}$는 위상차의 영향을 크게 받았고, 넓은 빈도분포를 보였다. 그러나 적층수가 증가함에 따라 분포의 폭은 감소하였고 평균값은 일정한 값으로 수렴하였다. 반면에, 섬유다발의 면내 방향으로의 이동 및 적층수의 변화는 $G_{xy}$에 거의 영향을 미치지 않는 것으로 나타났다.

• 대기
• /
• 제18권2호
• /
• pp.147-158
• /
• 2008

Domestic IOP (intensive observing period) has mostly been represented by the KEOP (Korea Enhanced Observing Period), which started the 5-yr second phase in 2006 after the first phase (2001-2005). During the first phase, the KEOP had focused on special observations (e.g., frontal systems, typhoons, etc.) around the Haenam supersite, while extended observations have been attempted from the second phase, e.g., mountain and downstream meteorology in 2006 and heavy rainfall in the mid-central region and marine meteorology in 2007. So far the KEOP has collected some useful data for severe weather systems in Korea, which are very important in understanding the development mechanisms of disastrous weather systems moving into or developing in Korea. In the future, intensive observations should be made for all characteristic weather systems in Korea including the easterly in the central-eastern coastal areas, the orographically-developed systems around mountains, the heavy snowfall in the western coastal areas, the upstream/downstream effect around major mountain ranges, and the heavy rainfall in the mid-central region. Enhancing observations over the seas around the Korean Peninsula is utmost important to improve forecast accuracy on the weather systems moving into Korea through the seas. Observations of sand dust storm in the domestic and the source regions are also essential. Such various IOPs should serve as important components of international field campaign such as THORPEX (THe Observing system Research and Predictability EXperiment) through active international collaborations.

• 한국환경보건학회지
• /
• 제22권1호
• /
• pp.36-44
• /
• 1996

A comparison was made of two detection methods(UV absorbence detection and fluorescence detection with pre-column derivatization, with trifluoroacetic acid) coupled with HPLC for the simultaneous determination of aflatoxin $B_1, B_2, G_1$ and $G_2$. A good separation of the four aflatoxins was achieved on a reversed-phase $C_{18}$ column (30 cm x 3.9 mm) with methanol-acetonitrile-water(20+20+60) for absorbence detection or acetonitrile-water(25+75) for fluorescence detection at the flow rate of 1.0 ml/min. The calibration graphs were linear over the ranges 100 ppb-1 ppm for $B_1/G_1$ and 30~300 ppb for $B_2/G_1$ with absorbence detection, and 1~500 ppb for $B_1/G_1$ and 0.3~150 ppb for $B_2/G_2$ with fluorescence detection. The correlation coefficients were greater than 0.94 and 0.99 for absorbance detection and for fluorescence detection, respectively. The detection limit was 100 ng for $B_1/G_1$ and 30 ng for $B_2/G_2$ with absorbence detection, and 1 ng for $B_1/G_1$ and 0.3 ng for $B_2/G_2$ with fluorescence detection. Recovery rates of aflatoxin $B_1, B_2, G_1$ and $G_2$ added to yeast-extract sucrose broth medium were 66.6%, 59.4%, 67.5% and 59.2%, respectively, for absorbence detection and 82.9%, 71.5%, 80.0% and 69.3%, respectively, for fluorescence detection. The four aflatoxins in culture medium were quantitatively detected by the two methods. The aflatoxins in the rice sample were not detected the absorbence detection method, but were below 10 ppb using the fluorescence detection method. Analysis of aflatoxins by both the absorbence and fluorescence methods coupled with HPLC showed acceptable linearity and good recovery. The absorbence detection was less timeconsuming and safer for treatment. The fluorescence detection was more elective and sensitive though elevated $B_1$ and $G_1$ contents were determined from the TFA-induced conversion of $B_1$ to $B_{2a}$ and $G_1$ to $G_{2a}$.

• 한국독성학회:학술대회논문집
• /
• 한국독성학회 2001년도 International Symposium on Dietary and Medicinal Antimutgens and Anticarcinogens
• /
• pp.95-96
• /
• 2001

The mutagenic and antimutagenic activities of catechin, hamamelitannin and two proanthocyanidin fractions prepared from the bark of Hamamelis virginia L. - a commonly used medicinal herb - were investigated in a human derived hepatoma (Hep G2) cell line using the single cell gel electrophoresis (SCGE, syn. Comet assay) for the detection of DNA-migration. The cells possess different phase I and phase II enzymes involved in the biotransformation of xenobiotics.(omitted)

• Bulletin of the Korean Chemical Society
• /
• 제35권1호
• /
• pp.123-128
• /
• 2014

In this study, we have investigated the flow rate effects of Ag nanoparticle (NP) suspensions on the progress of the cell cycle by using a microfluidic image cytometry (${\mu}FIC$)-based approach. Compared with the conventional "static" exposure conditions, enhancements in G2 phase arrest were observed for the cells under continuously flowing "dynamic" exposure conditions. The "dynamic" exposure conditions, which mimic in vivo systems, induced an enhanced cytotoxicity by accelerating G2 phase arrest and subsequent apoptosis processes. Moreover, we have also shown that the increases in delivered NP dose due to the continuous supply of Ag NPs contributed dominantly to the enhanced cytotoxicity observed under the "dynamic" exposure conditions, while the shear stress caused by these slowly flowing fluids (i.e., flow rates of 6 and $30{\mu}L/h$) had only a minor influence on the observed enhancement in cytotoxicity.

• 방사선산업학회지
• /
• 제4권1호
• /
• pp.91-94
• /
• 2010

A number of epidemiological studies as well as biological experiments, showed that genistein, one of the isoflavone, prevents prostate cancer occurrence. In this study, we showed that genistein inhibited the cell proliferation of human promyeoltic leukemia HL-60 cells and induced G2/M phase arrest. In addition, combination of genistein treatment and ${\gamma}$-irradiation displayed synergistic effect in apoptotic cell death of HL-60 cells. This means that the repair of genistein-induced DNA damage was hindered by ${\gamma}$-radiation and thus cell death was increased. In conclusion, genistein is one of the important chemicals that sensitize radiation-induced cell death.

• 한국초지조사료학회지
• /
• 제39권1호
• /
• pp.1-8
• /
• 2019

본 연구는 사양실험에 의한 회귀식 추정방법에 의해 교잡종(개량종) 번식용 암컷 흑염소의 육성기와 임신기 유지와 성장을 위한 에너지요구량을 구하기 위해 수행되었다. 번식용 암컷 흑염소 50두를 공시하여 사료의 대사에너지 수준을 육성기(5개월령)에는 각각 2.32(G1), 2.49(G2), 2.74(G3), 2.99(G4) 및 3.24(G5) Mcal/kg로 하여 2016년 5월부터 9월까지 진행하였으며, 임신기(9개월령 이후)에는 각각 2.32(P1), 2.43(P2), 2.55(P3), 2.66(P4) 및 2.78(P5) Mcal/kg로 하여 2017년 1월부터 4월까지 수행하였다. 실험사료는 염소용 TMR 사료를 이용하여 조단백질 수준을 14%로 고정시키고 에너지 첨가제(유락)를 이용하여 에너지 수준을 조절하였다. 건물 섭취량은 처리구 간에 육성기, 임신기 모두 유의성이 없었으며, 체중대비 1.5~2.0% 수준으로 조사되었다. 일당증체량은 육성기에는 46~69g, 임신기에는 150~190g으로 사료의 에너지수준이 증가함에 따라 높게 나타났으며, 사료요구율은 육성기 6.5~9.7의 범위로 에너지수준이 높을수록 사료요구율이 개선되는 경향을 나타내었다. 임신기의 경우 3.5~3.8의 범위로 에너지 수준에 따른 영향은 없는 것으로 나타났다. 대사 체중 당 에너지섭취량과 일당증체량 사이의 회귀분석을 통한 유지에너지 요구량 추정 시 육성기에는 $102.5Kcal/BW^{0.75}$이고, 임신기에는 $105.83Kcal/BW^{0.75}$로 나타났다. 급여 사료의 에너지 수준에 따른 번식성적은 에너지 수준이 높아질수록 분만율이 낮게 나타났으나 산자수와 생시체중의 경우 증가하는 경향을 보였다. 본 연구에서 도출된 결과는 향후 흑염소의 사양표준 설정을 위한 기초자료로 이용될 수 있을 것으로 사료되며, 앞으로 대사실험, 비교도축법 등 다양한 추정방법과 비교를 통해 정확도를 높이는 연구가 필요할 것으로 사료된다.

• Journal of Nutrition and Health
• /
• 제30권10호
• /
• pp.1188-1194
• /
• 1997

The aim of this was to investigate whether the regular consumption of kimchi influences the iron status (RBC , Hb, Ht, MCH, MCV, MCHC, transferrin , serum iron, and ferritin) in volunteers. Healthy male adults(n=12) took part in the study subdivided into the control Ⅰ-phase(for 2weeks), kimchi-phase (for 4 weeks), and control Ⅱ-phase(for 2 weeks). In addition to their normal diet, participant consumed 300g of lactic acid fermented Chinese cabbage kimchi daily for four weeks. In the control Ⅰ and control Ⅱ phases, the participants kept up their normal diets without consuming any fermented foods. Dietary intakes were recorded for 3 consecutive days in each phase, with the aid of household measures. Every two weeks. blood specimens were analysed. Significant differences(p<0.05) between the phases were found in MCHC, and transferrin in blood were not significantly changed during kimchi consumption. However, serum iron and ferritin levels were significantly increased(p<0.05) during kimchi consumption, achieving the highest levels in the fourth week of the kimchi components(ascrobic acid, sulfer compound, organic acid, capsaicin, gingerol , allicin). Because of lacticacid fermented kimchi's potential to prevent anemia , the consumption of this food can be recommended.

• TTA 저널
• /
• 통권178호
• /
• pp.8-13
• /
• 2018

최근 조선 및 해운경기가 급격히 위축되면서 해운사는 보다 많은 이익을 창출하기 위하여 첨단 ICT기술을 도입하여 최소 운항비 최대 이익 창출을 꾀하고 있다. IMO는 새로운 화두로서 자율운항선박이 운항 가능하도록 법적 개념 정립을 2020년까지 완료하도록 계획하고 있다. 산업계는 IMO의 NOx규제 Tier III(3.4 g/kWh, n<130), EEDI($CO_2$ 배출규제)의 Phase 1(Phase 0 대비 10%포인트 감소), Phase 2(Phase 1 대비 10%포인트 감소), EEOI 등 친환경선박 문제가 현안으로 대두되고 있는 상태에서 ICT와 결합하여 친환경 에코선박으로써 스마트선박이 문제를 해결하도록 기대하고 있다. 자율운항선박의 도입에 관해 많은 해운 전문가들 사이에 찬반의 의견이 분분하나 첨단 ICT를 도입하여 최소 운항비 최대 이익 창출을 추구하는 친환경 스마트선박의 도입에 대해서는 해운사 선주, 조선소 모두 앞을 다투고 있는 실정이다. 이러한 시점에서 세계 각 국가가 추진하고 있는 스마트자율운항선박의 연구와 기술 및 표준 동향과 우리나라가 추진하고 있는 연구와 산업계의 동향을 알아보고 새로운 전기를 맞이하게 될 글로벌 조선 산업의 미래를 조명해 보고자 한다.