• 한국대기환경학회지
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• 제18권6호
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• pp.475-485
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• 2002

An analytical method was investigated for the meaiiurement of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) concentrations in air samples. Procedures required for column chromatographic clean up. silicagel (stage I) and gel permeation chromatography (stage II), were discussed. Identification and quantification of PCBs and OCPs were performed using a combination of gas chromatography/mass spectrometry/ selected ion monitoring. Recovery tests calculated from six samples are 68∼137% for PCBs and 58∼130% for OCPs except for endrin aldehyde. Instrumental detection limits determined for the PCBs and OCPs varied from 0.05 to 0.18 pg/m3 and from 0.71 to 16.82 pg/㎥, respectively. The method has been applied to the analysis of air samples collected at Ansung city, Kyonggi province, Korea. This method may serve as a screening protocol for the simultaneous determination of PCBs and OCPs in air.

• 한국자동차공학회논문집
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• 제10권5호
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• pp.23-28
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• 2002

As the interest on the air pollution is gradually rising up at home and abroad, automotive industries have been working on the exhaust emission reduction from vehicles through a lot of approaches, which consist of new engine design, innovative aftertreatment systems, and using clean fuels. Methanol, ethanol, LNG, LPG, H2, reformulated gasoline are generally recognized as the clean fuel. Since the low price policy of government on LPG has expanded its vehicle market recently, there is concern of the exhaust emission of LPG vehicle. In this paper, we studied the value of LPG fuel as a clean fuel by comparing the results of the exhaust emission from LPG and Gasoline fueled vehicles, and discussed its limitation of LPG vehicle with mixer type as a fuel supply system. FTIR was used to understand the difference of exhaust emission components of LPG and Gasoline fueled vehicles.

• 청정기술
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• 제15권1호
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• pp.1-8
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• 2009

전 세계적으로 급성장하고 있는 자동차연료로 압축천연가스(CNG)의 사용이 일반화되고 있다. 1996년도에 100만 대이던 CNG자동차가 2006년도에는 5배가 증가하였으며, 지금도 계속 증가하고 있는 추세이다. CNG연료는 가솔린 및 디젤연료에 비하여 효율적이고 완전연소에 가까워 청정연료로서 적합하다. 또한 배출 가스로서 일산화탄소, 탄화수소 및 질소산화물 등이 다른 연료에 비하여 유리하며, 경제적인 면에서도 투자가치가 있다. 본 연구에서는 천연가스자동차의 환경적인 특성화 효율적이고 경제적인 면에서 고찰하고자 한다.

• 대한기계학회논문집
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• 제7권2호
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• pp.233-239
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• 1983

Gasification of rice chaff has traditionally been used to produce a clean fuel suitable for lighting, heating and engine application. Since oil crisis, a series of experimental study has been performed to drive a farm engine by agricultural wastes. We produced a combustible gas from rice chaff with a fixed bed up-draught gasifier system, and applied it to a conventional farm kerosene engine. This experiment was quite successful one. We could drive the farm engine with maximum horse power of 9 PS by rice chaff gas which was fairly competitive to the continuous horse power of 10 PS obtained when kerosene was used. Problems of tar existence in gas have been discussed, but we are confident that these can be solved in near future. Development and application of the gasification process will help our farm economy, not only by conserving petroleum oil but by utilizing agricultural wastes.

• Archives of Pharmacal Research
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• 제15권2호
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• pp.109-114
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• 1992

For the risk assessment of human exposure to volatile halogenated hydrocarbons, a dynamic purge trap/on-column cryofocusing method using capillary gas chromatograph-$^{63}Ni$ electron capture detector and thermal desorption unit was applied to analyze the free forms, metabolites of 1, 1, 2-trichloroethylene and 1, 1, 2, 2-tetrachloroethylene. The urine sample was diluted with distilled water, hydrolyzed and sealed. Then the inert gas was infused to purge out free 1, 1, 2-trichloroethylene, free 1, 1, 2, 2-tetrachloroethylene and urichloroethanol. These compounds were trapped to $Tenax^R$ / GC-gas trap device throughout clean up tube. Being undertectable to gas chromatograph directly, trichloroacetic acid was methyl esterificated and trapped in the manner above mentioned. The optimal incubation time to get best recovery of methyl ester was 4 hours at $60^circ$C. The concentrations of free volatile halogenated hydrocarbons and their metabolites in urine were obtained of free volatile halogenated hydrocarbons and their metabolites in urine were obtained from 5 healthy volunteers. This analytical method is expected to make the biological monitoring more precise and convenient.

• Corrosion Science and Technology
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• 제16권2호
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• pp.49-58
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• 2017

Many research efforts on the effect of nitrogen on the corrosion resistance of stainless steels have been reported, but little research has been conducted on the effect of nitrogen for the weldment of stainless steels by the seal-weld method. Therefore, this work focused on the determining the corrosion resistance of tube/tube sheet mock-up specimen for sea water condensers, and elucidating the effect of shielding nitrogen gas on its resistance. The pitting corrosion of autogenously welded specimen propagated preferentially along the dendritic structure. Regardless of the percent of shielding nitrogen gas, the analyzed nitrogen contents were very much lower than that of the bulk specimen. This can be arisen because the nitrogen in shielding gas may partly dissolve into the weldment, but simultaneously during the welding process, nitrogen in the alloy may escape into the atmosphere. However, the pitting resistance equivalent number (PREN) of the interdendrite area was higher than that of the dendrite arm, regardless of the shielding gas percent; and the PREN of the interdendrite area was higher than that of the base metal; the PREN of the dendrite arm was lower than that of the base metal because of the formation of (Cr, Mo) rich phases by welding.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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• pp.112.1-112.1
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• 2010

To develop domestic IGCC gasification technology, a gasification test bed with a capacity of 20 tons/day has been designed. The main components of the test bed designed are a coal pulverizing and feeding facility, a gasifier, a syngas cooler, a gas treatment unit, oxygen and nitrogen tanks, and flare stack. For wide applications to the development of advanced coal gasification technology, many special functions have been given to it such as syngas recirculation, char recirculation, and multiple stage gasification. The test bed will be used for testing the characteristics of various types of coals, deriving optimum conditions for efficient gasifier operation and trouble shooting for the Korea IGCC demonstration plant. It will also be applied as a useful tool to develop scale-up design technology of IGCC and proceed to commercialization.

• 분석과학
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• 제13권4호
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• pp.484-493
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• 2000

생물시료 중 존재하는 알킬페놀류, 클로로페놀류 및 비스페놀 A의 동시분석을 기체크로마토그래피-질량분석기-선택이온검색법에 의해 수행하였다. 시료 중 페놀류는 유기용매로 추출하고 정제과정은 Florisil과 silica 컬럼을 비교분석하였다. 회수율 실험은 각 생물시료에 1-ppm 정도를 첨가하여 수행하였다. 이들의 회수율은 83-116% 정도로 나타났고, 표준편차는 약 2.4-11.9%로 나타났다. 페놀류의 검출한계를 증진시키기 위하여, trimeaylsilyl(TMS) 유도체 방법을 도입하였다. 유도체화 시키지 않은 페놀과 TMS 유도체화된 페놀류의 기체크로마토그래피 성질을 연구하였다.

• 한국가스학회지
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• 제25권6호
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• pp.35-44
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• 2021

반도체 공정 중 PR (Photo Resist) 공정은 여러 인화성 물질을 혼합하여 사용하는 공정으로, 공정 장비가 Clean Room 내 설치되어 인화성 물질이 누출되는 경우 질식, 화재, 폭발 사고로 이어질 위험성이 크므로, 물질 누출시 발생할 수 있는 사고에 대한 영향을 분석하고, 작업자들의 안전을 보장할 수 있는지 평가하는 것이 필요하다. 본 연구는 FLACS CFD - Fire Module을 이용하여 10개의 누출, 화재 시나리오에 대한 CFD Simulation을 통해 Clean Room 내부 가상으로 설정한 Monitor Point에서의 복사열 및 온도 변화 값을 확인하였다. Clean Room 내부에서 발생한 화재는 층간 구조물에 높은 복사열을 전달하지만, 그 범위가 상당히 제한적이며, 단일 화재 사고로 인해 붕괴될 가능성이 희박하다. 화재 사고로 인해 탈출구로 이어지는 2 곳의 계단이 동시에 높은 복사열에 노출되는 시나리오는 없어, 화재 발생시 작업자가 탈출 가능하였다. 또한 복사열 및 온도 상승의 수준은 아래층으로 이동하면서 급격하게 낮아지는 것을 확인하였으며, API 520의 기준에 따라 작업자가 30초 동안 버틸 수 있는 복사열인 6.31 kW/m²에 노출된 작업자도 화재가 발생한 Clean Room 내부에서 충분히 탈출할 수 있음을 확인하였다.

• 한국소음진동공학회논문집
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• 제16권9호
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• pp.964-970
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• 2006

Micro gas turbine(MGT) has received attention recently as small-scale distributed power sources. With characteristics such as their small size, lightweight, low maintenance cost and minimal vibrations during operation, they are expected to become widespread in a wide range of ' applications, including residential and small-scale industrial use. It is very easier to start-up and stop the MGT system which is the friendly environmental power system has just below the 9ppm NOx emmission and good quality of noise level. The exhaust heat emitted by the MGT is in the form of about $300^{\circ}C$ clean exhaust gas. The exhaust gas is suitable for absorption chiller/heater system. 1 has researched performance characteristics of the 60 kW class MGT-absorption chiller-heater system in the local condition. Variations of heat recovery from exhaust gas has measured according to micro gas turbine output of 15, 30, 45, 60kW. From those results, the performance of the MGT-absorption chiller/heater system has been evaluated.