• Journal of Microbiology
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• 제34권2호
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• pp.137-143
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• 1996

We isolated a promoter inducible by paraquat, a superoxide-generating agent, from Escherichia coli using a promoter-probing plasmid pRS415. From sequence analysis we found out the promoter is for fpr ENCODING nadph : ferredoxin oxidoreductase. We constructed on operon fusion of lacZ gene with fpr promoter to monitor the expression of the gene in the single-copy state. LacZ expression generators, menadione and plumbagin, also induced the expression of .betha.-galactosidase in the fusion strain. On the other hand, no significant induction was observed by treatment with hydrogen peroxide, ethanol, and heat shock. Induction of .betha.-galactosidase was significantly reduced by introducing a .DELTA. sox 8 :: cat of soxS3 :: Tn10 mutation into the fusion strain, indicating that fpr gene is a member of the soxRS regulon. The transcriptional start site was determined by primer extension analysis. Possible roles of fpr induction in superoxide stress were discussed.

• 설비공학논문집
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• 제7권4호
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• pp.600-610
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• 1995

When combustion gas is cooled down below the dew point of sulfuric acid vapor in the heat recovery systems, condensation occurs. Since the condensed sulfuric acid solution causes low-temperature corrosion in materials, it is important to measure the SOx dew point by electric measurement. In this study, two kinds of probes having electric gaps of 1mm or 2mm were used. and experiments were carried out by the parameters of sulfuric acid vapor and water vapor concentration. The changes of electric current caused by sulfuric acid condensed on the surface of probe according to the cooling rate and the probe head surface temperature were sudied. The opimum cooling rate was decreased with the increasing of water vaper concentration regardless of sulfuric acid concentration. The sensitivity of electric current is improved for the narrower gap(1mm) of ring electrodes, but it rarely affects the SOx dew point measuring of different probes according to the change of cooling rate.

• 한국대기환경학회지
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• 제14권5호
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• pp.455-464
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• 1998

Removal teals of Soxmox were performed using low density ceramic filters doped with various catalysts. Disc type (50 mmO.Dx10 mmt) low density ceramic filters were doped with three different catalysts such as Cu to remove SOx and NOx, and Mn and Co to remove NOx. The air permeabilities and specific surface areas were 40~50cc/min.cm2.cmH2O and 4.1~8.88 m2/g, respectively. Also, the peak pore sizes of catalyst support were 3~5nm. Tests were focused to search optimum operating temperatures for different catalysts. It was found that as the CuO content increases, SOx removal efficiency was increased. NOx removal efficiencies for Mn, Cu and Co, were 85% at 30$0^{\circ}C$, 90% at 40$0^{\circ}C$ and 90% at 45$0^{\circ}C$, respectively.

• Animal Bioscience
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• 제36권12호
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• pp.1905-1917
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• 2023

Objective: Nanog homeobox (NANOG) is a core transcription factor that contributes to pluripotency along with octamer binding transcription factor-4 (OCT4) and sex determining region-Y box-2 (SOX2). It is an epiblast lineage marker in mammalian pre-implantation embryos and exhibits a species-specific expression pattern. Therefore, it is important to understand the lineage of NANOG, the trophectoderm, and the primitive endoderm in the pig embryo. Methods: A loss- and gain-of-function analysis was done to determine the role of NANOG in lineage specification in parthenogenetic porcine blastocysts. We analyzed the relationship between NANOG and pluripotent core transcription factors and other lineage makers. Results: In NANOG-null late blastocysts, OCT4-, SOX2-, and SOX17-positive cells were decreased, whereas GATA binding protein 6 (GATA6)-positive cells were increased. Quantitative real-time polymerase chain reaction revealed that the expression of SOX2 was decreased in NANOG-null blastocysts, whereas that of primitive endoderm makers, except SOX17, was increased. In NANOG-overexpressing blastocysts, caudal type homeobox 2 (CDX2-), SOX17-, and GATA6-positive cells were decreased. The results indicated that the expression of primitive endoderm markers and trophectoderm-related genes was decreased. Conclusion: Taken together, the results demonstrate that NANOG is involved in the epiblast and primitive endoderm differentiation and is essential for maintaining pluripotency within the epiblast.

• 대한환경공학회지
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• 제22권2호
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• pp.211-216
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• 2000

본 연구는 오염가스 제거시 발생되는 부산물인 에어로졸 입자가 방전전극에 부착되어 생기는 방전불안으로 제거율이 급격히 저하되는 문제점을 개선하고 제거장치의 운전비용을 감소시키기 위한 연구이다. 이를 위해 오염가스 제거에 필요한 라디칼과 이온을 발생시키기 위한 전기방전영역과 연소가스가 흐르는 관로를 분리시킨 플라즈마 반응기를 사용하여 방전불안에 의한 제거효율 저하와 방전선 산회 문제를 개선하여 장시간 운전 가능성을 확인하였고, 또한 운전비용을 감소시키기 위해서는 코로나 방전에 의한 비열플라즈마를 이용하여 연소가스를 산화 변화시키고, 첨가제로 수산화나트륨 수용액 증기와 소량의 암모니아를 사용하였다. 그 결과 암모니아 분자 몰비를 1.5로 하고, 유량이 $2.5{\ell}/min$인 질소가스로 농도가 20%인 수산화나트륨 수용액을 버블링하여 주입하였을 때 질소산화물, 황산화물 제거율이 각각 95, 100%인 우수한 제거특성을 얻었다.

• 해양환경안전학회지
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• 제2권S1호
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• pp.77-85
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• 1996

As conservation of global environment has becoming a major outstanding issue of the world, the International Maritime Organization(IMO) has been legislation a convention for prevention of air pollution from ships. By the new convention, use of air pollutants such SOx, NOx, Freon and Halin Gas shall be restricted. In this regards, analysing these requirements of the convention is required as the cinvention will also be applied in restriction of descharging exhaust gases from ships by estsblishing a requirement of Sox and NOx discharged. The purpose of this study is as follows; 1) Introdcuing of the backgrounds of legislating the convention for prevention of air pollution from ships and major contents of the convention and a countermeasuures in the convention by Korea 2) Reviewing by analyzing the influence in domestic industries concernd by restriction of SOx, NOx in exhaust gases and sulpher content of fuel oil 3) Preparing a countermeasure in the convention properly.

• Journal of Advanced Marine Engineering and Technology
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• 제20권2호
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• pp.69-69
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• 1996

As conservation of global environment has becoming a major outstanding issue of the world, the International Maritime Organization(IMO) has been legislation a convention for prevention of air pollution from ships. By the new convention, use of air pollutants such as SOx, NOx, Freon and Halon Gas shall be restricted. In this regards, analysing these requirements of the convention is required as the convention will also be applied on restriction of discharging exhaust gases from ships by establishing a requirement of SOx and NOx discharged. The purposed of this study is as follows ; 1) Introducing of the backgrounds of legislating the convention for prevention of air pollution from ships and major contents of the convention and a countermeasures on the convention by Korea. 2) Reviewing by analyzing the influence on domestic industies concerned by restriction of SOx, NOx in exhaust gases and sulphur content of fuel oil. 3) Preparing a countermeasure on the convention properly.

• 구강회복응용과학지
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• 제40권1호
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• pp.13-23
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• 2024

목적: 인간간엽줄기세포를 연골세포로 분화유도하는 성장인자 규명 및 주사침 크기 차이에 따른 세포증식 증진 비교이다. 연구 재료 및 방법: 인간간엽줄기세포를 연골세포유도배지에서 14, 21, 28일 배양하여 BMP-2, BMP-4, BMP-6, BMP-7, BMP-13, FGF-2, FGF-18, IGF-1, TGF-β1. TGF-β2, TGF-β3를 투여한 군들과 대조군에서 SOX-5, SOX-6, SOX-9 및 FOXO1A의 발현량을 분석하였다. 18, 21, 26 게이지(G) 주사침을 사용하여 배양접시에 인간간엽줄기세포를 접종하고 24, 48, 72시간 후 각각 세포증식을 측정하였다. 결과: 기존에 알려진 FGF, IGF-1, TGFβ1와 함께, BMP-2, BMP-4, BMP-6, BMP-7 등 BMP family 성장인자들에 의하여 연골세포분화 전사인자 유전자들인 SOX-5, SOX-6, SOX-9, FOXO1A의 유전자발현이 증가하였다. 48시간에서는 가장 작은 주사침인 26G군이 대조군 및 18G군에 비하여 유의한 세포증식 증진을 보였으며, 72시간에서도 가장 작은 주사침인 26G군이 대조군에 비하여 유의한 세포증식 증진을 보였다. 결론: 인간간엽줄기세포의 연골세포분화 유도능을 가진 성장인자들을 고찰할 수 있었고 주사침 크기에 따른 세포증식 변화를 규명할 수 있었다.

• 에너지공학
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• 제13권2호
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• pp.133-143
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• 2004

Simultaneous removal technology of particulate/NOx/SOx/HCl using CuO/3Al$_2$O$_3$ㆍ2SiO$_2$catalyst impregnated ceramic candle filters is an advanced air pollution process and provides significantly to reduce hazardous gases emitted from coal-fired power plant. This process uses a high-temperature catalytic filter for integrating SOx and HCl reduction through injection an alkali sorbent (such as hydrated lime or sodium bicarbonate), NOx removal through ammonia injection and selective catalytic reduction (SCR), and particulate collection on the catalytic filter surface. The advantages of the process include : compact integration of the emission control technologies into a single component; easy handling of dry sorbent and by-product; and improved SCR catalytic life due to lowered SOx, HCl and particulate levels. CuO/3Al$_2$O$_3$ㆍ2SiO$_2$ catalyst impregnated ceramic candle filters showed a possibility of simultaneous treatment from results which have ascertained high removal efficiency at various combined gases conditions, and in pilot plant test for 3 months, NO conversion was showed 90% over.

• 한국응용과학기술학회지
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• 제34권2호
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• pp.289-295
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• 2017

현 국제해사기구(IMO)에서의 선박엔진에서 발생되는 NOx와 SOx 등의 연소 가스 배출에 대한 규제 강화에 따라, 발트 해 연안을 지나는 모든 선박들은 배출되는 연소가스 저감장치를 장착해야 된다. 국내에서도 IMO의 규제에 따른 NOx와 SOx를 저감장치를 개발하고 있으며, 그중에 대표적인 장치인 Scrubber는 세정액으로 암모니아수와 요소수를 사용하게 되고 사용된 폐 세정액에는 NOx와 SOx와 반응한 질산암모늄과 황산암모늄이 포함되어 있다. 본 연구에서는 폐 세정액이 포함하고 있는 유용한 부산물을 유기용매를 사용하는 염석법을 적용하여 회수하였다. 질산암모늄과 황산암모늄의 회수방법과 질안석회를 추출 후 회수된 부산물의 정성분석을 위하여, FT-IR 분석을 통하여 물질의 정성적 특성과 화학적 조성을 평가해 보았다. 한편 응집제를 투입하여 질안석회를 침전시켜 비료상의 물질로 회수하였다. $FeSO_4$ 응집제와 $CaCl_2$를 응집보조제로 사용하고 입자의 크기를 키우기 위해 $CaCO_3$를 사용하였다.