• 제목/요약/키워드: TGM

검색결과 37건 처리시간 0.024초

서울시 대기 중 총 가스상 수은의 농도 및 특성 분석 (Atmospheric Total Gaseous Mercury (TGM) Concentration and Characteristics in Seoul, Korea)

  • 이용미;허종배;이승묵
    • 한국환경보건학회지
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    • 제34권1호
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    • pp.42-48
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    • 2008
  • The objectives of this study were to measure ambient TGM concentrations in Seoul Korea, to determine the temporal variation of TGM, and to analyze the relationships among TGM, meteorological data and PM2.5 measured at the same time. Ambient TGM and PM2.5 concentrations were measured at the roof of the Graduate School of Public Health building in Seoul, Korea for the period of January to October 2004. Average TGM concentration was $3.43{\pm}1.17ng/m^3$. The average TGM was at a low concentration similar to those of background sites in other countries. The temporal variations and meteorological phenomena of TGM were not statistically significant. There was a positive link between TGM and PM2.5. It didn't indicate that reduction of $Hg^{2+}$ to Hg0 had occurred in liquid water contained in smog as in a previous study, but it shows that PM2.5 and TGM could be emitted from the same sources such as power plants and combustion engines. Also, the strong correlation between TGM and $SO_2$ concentrations indicated that the source of TGM was from fossil fuel combustions including coal combustion. Specifically, $SO_2\;and\;SO_4{^2-}$ concentrations correlated to TGM concentrations could be linked to TGM emitted from local and regional sources as well.

Hybrid receptor model을 이용한 대기 중 총 가스상 수은의 오염원 위치 추정 연구 (Identifications of Source Locations for Atmospheric Total Gaseous Mercury Using Hybrid Receptor Models)

  • 이용미;이승묵;허종배;홍지형;이석조;유철
    • 한국환경과학회지
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    • 제19권8호
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    • pp.971-981
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    • 2010
  • The objectives of this study were to measure ambient total gaseous mercury (TGM) concentrations in Seoul, to analyze the characteristics of TGM concentration, and to identify of possible source areas for TGM using back-trajectory based hybrid receptor models like PSCF (Potential Source Contribution Function) and RTWC (Residence Time Weighted Concentration). Ambient TGM concentrations were measured at the roof of Graduate School of Public Health building in Seoul for a period of January to October 2004. Average TGM concentration was $3.43{\pm}1.17\;ng/m^3$. TGM had no notable pattern according to season and meteorological phenomena such as rainfall, Asian dust, relative humidity and so on. Hybrid receptor models incorporating backward trajectories including potential source contribution function (PSCF) and residence time weighted concentration (RTWC) were performed to identify source areas of TGM. Before hybrid receptor models were applied for TGM, we analysed sensitivities of starting height for HYSPLIT model and critical value for PSCF. According to result of sensitivity analysis, trajectories were calculated an arrival height of 1000 m was used at the receptor location and PSCF was applied using average concentration as criterion value for TGM. Using PSCF and RTWC, central and eastern Chinese industrial areas and the west coast of Korea were determined as important source areas. Statistical analysis between TGM and GEIA grided emission bolsters the evidence that these models could be effective tools to identify possible source area and source contribution.

Regulation of Inflammatory Response in Periodontal Ligament Cells by Transglutaminase 2

  • Lee, Sun Young;Jang, Cheol Hun;Ryu, Je-Hwang
    • International Journal of Oral Biology
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    • 제42권4호
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    • pp.191-196
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    • 2017
  • Transglutaminase2 (TGM2) is a multi-functional calcium dependent enzyme that affects angiogenesis, apoptosis, differentiation, attachment, and changes in the extracellular matrix. However, its function in periodontal tissue has not yet been studied. The aim of this study was to investigate the association of the TGM2 expression and the modulation of inflammatory mediators in inflamed periodontal ligament (PDL) cells induced by pro-inflammatory cytokines such as Interleukin-$1{\beta}$ and the Tumor necrosis $factor-{\alpha}$. The expression of TGM2 was increased in the inflamed periodontal tissue and PDL cells. Over-expressed TGM2 in the PDL cells increased expression of MMP1, MMP3, IL-6, CXCL8, and PTGS2. Conversely, inhibition of TGM2 activity using LDN27219, a TGM2 inhibitor, resulted in decreased expression of MMP1, MMP3, IL-6, and CXCL8. The mRNA expression was confirmed by RT-PCR and quantified by qRT-PCR. Protein levels were also confirmed by immunofluoroscence staining. These results suggest that TGM2 plays an important role in the regulation of inflammatory mediators which exacerbate tissue damage in inflamed periodontal tissue.

춘천시 대기 중 가스상 수은 종 농도 특성에 관한 연구 (Characteristics of Atmospheric Speciated Gaseous Mercury in Chuncheon, Korea)

  • 간순영;이승묵;한영지
    • 대한환경공학회지
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    • 제31권5호
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    • pp.382-391
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    • 2009
  • 본 연구에서 2006년 3월부터 2008년 11월까지 측정한 총 가스상 수은(TGM)과 가스상 산화수은(RGM)의 농도는 각각 2.10 ${\pm}$ 1.50 ng/$m^3$, 3.00 ${\pm}$ 3.14 pg/$m^3$으로 나타났다. RGM 농도는 밤보다 낮 시간에 월등히 높은 농도를 보였으며 이는 낮에 고농도로 존재하는 오존 등 산화제에 의한 광화학 반응으로 인하여 가스상 산화수은이 생성되는 것으로 설명할 수 있다. 한편 안개 발생 횟수가 많은 춘천에서는 가스상 산화수은 농도와 오존농도가 특히 안개일에 유의미한 상관관계를 보였다. 이는 액적 상태일 때, 금속수은($Hg^0$)의 산화반응에서 오존이 중요한 역할을 한다는 것을 의미한다. 또한 총 가스상 수은은 대표적인 장거리 이동 오염물질인 CO 및 $PM_{10}$과는 상관관계를 보이는 반면, 국지 오염물질인 $NO_2$와는 상관관계가 없는 것으로 나타났다. 수은의 주요 발생원이 산업시설에서의 화석연료의 연소라는 것을 고려할 때, 산업시설이 부재한 춘천에서는 총 가스상 수은의 농도가 지역 오염원에 의해서는 크게 영향을 받지 않는다는 것으로 판단된다. 그리고 총 가스상 수은의 고농도와 저농도를 대표하는 시료의 역궤적을 계산한 결과, 춘천의 총 가스상 수은 농도에 영향을 주는 지역은 선양, 베이징을 포함한 중국의 산업지역이라는 것을 확인할 수 있었다.

Influence of Electrolyte Composition on Electrochemical Performance of Li-S Cells

  • Kim, Tae Jeong;Jeong, Bo Ock;Koh, Jeong Yoon;Kim, Seok;Jung, Yongju
    • Bulletin of the Korean Chemical Society
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    • 제35권5호
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    • pp.1299-1304
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    • 2014
  • The electrochemical performance of Li-S cells was investigated in various ternary electrolyte solutions composed of 1,2-dimethoxyethane (DME), tetra(ethylene glycol) dimethyl ether (TGM), and 1,3-dioxolane (DOX). The discharge capacity values and cycle data obtained at each composition were statistically treated with the Minitab program to obtain mixture contour plots, from which the optimal composition of the ternary solvent systems was predicted. The discharge capacities and capacity retention were quite dependent on the electrolyte composition. It was estimated from the contour plots of the capacity at 1.0 C that the discharge capacity sharply increased with a decrease in the TGM content. High capacities greater than 900 mAh/g at 1.0 C were expected for the electrolyte composition with a volume ratio of DME/TGM/DOX = 1/0/1. In contrast, it was predicted from the mixture contour plot of the capacity retention that the cycle performance would significantly increase with an increase in the DME content.