• Journal of Korean Society for Atmospheric Environment
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• v.4 no.1
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• pp.71-75
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• 1988

대기오염이 인체에 미치는 영향을 연구하기 위하여 오염의 농도가 지극히 심할 것으로 예측되는 고속도로 서울톨게이트에 근무하는 근로자 37명과 사무직 15명을 대상으로 혈액 및 요중 납함량과 요중 코프로포르피린을 정량하고 임파구 중 자매염색분체 교환빈도를 계산하여 인적특성에 따라 비교 검토하였다. 한편 대기오염의 정도를 파악하고자 1986년 4월부터 약 3개월에 걸쳐 아황산가스, 이산화질소, 일산화탄소, 부유분진, 납, 벤조파이렌 등 인체에 유해한 오염물질들을 톨게이트 근무자가 근무하는 위치의 공기 중에서 정량하였다. 이들 성적을 비교 검토한 바 다음과 같은 결론을 얻었다. 1. 톨게이트 내의 공기 중 이산화질소, 일산화탄소, 부유분진, 벤조파이렌, 납량 등이 서울시내 일반 대기보다 월등히 높았다. 2. 톨게이트 근로자의 혈중 납량, 요중 납 및 포프로포르린량, 그리고 임파구 내의 자매염색분체 교환빈도의 평균치가 사무직근로자보다 유의하고 높았다.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2012.05a
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• pp.347-348
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• 2012

수소가 포함 되지 않은 저밀도 구조의 카본 박막을 마그네트론 스퍼터링으로 합성하였다. 본 실험을 통하여 플라즈마 변수에 따른 저밀도 구조의 카본 박막의 미세 구조와 물리적 특성과의 상관관계를 FESEM, AFM, 4-point probe의 분석 기구를 통하여 분석 하였고, 비정질 저밀도 구조의 탄소 박막에 Pt을 ion sputtering을 통하여 도핑 한 결과 1000에서 $0.0013{\Omega}cm$ 까지 전기 비저항을 낮추는 결과를 얻었다.

• Proceedings of the Materials Research Society of Korea Conference
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• 2012.05a
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• pp.94.1-94.1
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• 2012

폴리페닐카보실란은 페닐그룹을 포함하고 있는 카보실란계 고분자로서 열분해 후 과량의 탄소를 함유할 수 있는 세라믹 전구체이다. 카보실란계열의 고분자는 산화특성이 있어 SiOC 코팅 용도에도 사용되고 있는데, 폴리페닐카보실란은 free 탄소를 함유하는 SiOC:C 필름을 형성할 수 있다. SiOC 코팅 전구체로는 일반적으로 실리카졸, 실라잔 계열의 고분자, 실록산 계열의 고분자가 사용되고 있으나, 폴리페닐카보실란의 경우 상기 전구체에 비하여 보관 안정성 및 뛰어난 부착특성을 나타낸다. 기존 연구에서는 폴리페닐카보실란으로부터 형성된 SiOC:C 필름의 저유전막, 산화방지막, 분진방지막 등의 응용성에 대하여 고찰한 바 있다. 폴리페닐카보실란은 열처리 온도 영역에 따라 응용 분야가 달라질 수 있는데, 이에 본 연구에서는 각 열처리 온도 영역에 따라 형성되는 SiOC:C 필름의 구조적 변화를 고찰하였다. 필름 형성은 20 % 폴리카보실란 용액을 스핀코팅하고 대기상에서 경화를 실시하였으며, 질소 분위기에서 400 ~ 1200 도 범위에서 열처리하였다. 이렇게 얻어진 300 nm 두께의 필름은 XPS 표면분석과 FT-IR, Solid-NMR을 이용하여 C-Si-O 네트워크 형성의 거동을 확인하였으며, 800 도 이상에서 나타나는 특징적인 free 탄소는 Raman을 이용하여 확인하였다.

• Journal of the Korean Electrochemical Society
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• v.10 no.4
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• pp.279-282
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• 2007

When reformer for fuel cell is used, CO in hydrogen gas leads to a seriously decreased membrane electrode assembly (MEA) performance by catalyst poisoning. The effect of CO on performance of modified MEA by sputtering method is studied in this paper. The experimental results show that sputtered Pt and Ru thin film improve a single cell performance of MEA and sputtered metal thin film has a CO tolerance. The air injection process on anode show improved CO tolerance test result. Moreover, Pt, Ru and PtRu thin film by sputtering had influence on the CO tolerance with air injection process.

• Korean Chemical Engineering Research
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• v.45 no.3
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• pp.277-285
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• 2007

The adsorption characteristics of multi-component solvent vapors including poorly-adsorbable chemicals such as toluene-xylene-MEK and toluene-MEK-IPA on the activated carbonaceous adsorbents were investigated in a stainless steel fixed bed of 10.2 cm ID and 50 cm in height in order to identify those carbons for eliminating and recovering solvent vapors from industrial emission sources. The used activated carbonaceous adsorbents were pelletized commercial activated carbons and activated carbon fiber. Breakthrough curves and adsorption capacity at atmospheric pressures were obtained. It has been found that non-polar and larger molecules have been adsorbed better than polar and smaller molecules. In special, alcohols and ketones were poorly adsorbed caused by competitive adsorbability in multi-component mixture system. However, it could be overcome by profitable employment of organization of cooperative system which was composed of different porosity activated carbonaceous adsorbents appropriately.

• Journal of the Korean Chemical Society
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• v.25 no.5
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• pp.331-333
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• 1981

• LP가스
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• v.21 no.6
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• pp.10-15
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• 2009

21세기의 이슈 중 가장 주목받고 있는 것은 '녹색성장'입니다. 정부 역시 '저탄소 녹생성장'을 향후 60년 비전으로 제시하여 에너지 위기와 경제위기를 동시에 타개해 나가겠다고 선포하였습니다. 이에 따라 환경부에서는 저탄소 녹색성장의 효율적 추진을 위해 지자체 기후변화대응 강화, 탄소포인트제 실시, 폐기물 에너지 자원화, 저탄소형 소비 생산 문화 확산, 온실가스감축 실천프로그램, 저탄소 자동차 보급 확대 등 10대 중점과제를 선정하여 단계별로 추진 중입니다. 지금부터는 고유가 시대에 저렴한 연료비로 관심을 바도 있는 LPG차량(완성차, 엔진개조차량 포함)의 연비 특성에 대해 살펴보겠습니다.

• Journal of Yeungnam Medical Science
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• v.8 no.2
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• pp.84-94
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• 1991

The purpose of this study was to evaluate the influence of high does carbon tetrachloride($CCl_4$) on the hepatotoxic effect of dimethylnitrosamine(DMN) which induces acute hemorrhagic necrosis in liver. Rats were injected intraperitoneally DMN dissolved in physiologic saline by a dose of 40mg/kg. For changes related to $CCl_4$ pretreatment, rats were injected intraperitoneally $CCl_4$ dissolved in olive oil by a dose of 0.4mg/kg, and then injected DMN. The livers were extracted from the rats 3, 6, 12, 24, 48, 72, and 120 hours after $CCl_4$ and/or DMN injection. Liver tissues were examined with light and electron microscopes. The results were summarized as follows ; Light microscopic findings : Severe centrilobular hemorrhagic necrosis developed from 12 hours after injection of DMN and continued to 120 hours. On injection of DMN after $CCl_4$ pretreatment, Massive necrosis occurred early. But active regenerative changes were produced in 24 hours. In 120 hours, the liver recovered in almost normal appearance. The degree of necrosis in pretreated group was similar to that in DMN injection only, and the time of recovery was faster in preteated group. Electron microscopic findings ; The early change was mainly disorganization of RER in DMN injection, and clumping and vesicular dilatation of ER in injection of $CCl_4$. In pretreatment group the early change was similar in appearance with $CCl_4$ group, but severer in degree. According to the results, it was revealed that acute toxic effect of DMN was recovered more rapidly in pretreatment group. Thus it was suggested that $CCl_4$ had protective effect in DMN hepatotoxicity.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.5
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• pp.713-719
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• 1995

These studies were carried out to investigate the effects of Puerariae radix catechins(PRC) administration on the biochemical parameters of liver function in liver of carbon tetrachloride(CCl4)-treated rats. Thirty six healthy Sprague-Dawley rats weighing about 120g were used for this experiment and divided intot he following 3 groups : normal control group(NCON), $CCl_4$ control group(CCON), PRC treated group(PRC). Fifty percent $CCl_4$ in oil was administered(I.P.) by 2ml per kg body weight two times a week for 3 weeks. PRC treated groups were administered orally at the leaves of 1% per day in distilled water for 8 weeks. Lipid hydroperoxides were analyzed by using chemiluminescence-high performance liquid chromatography(CL-HPLC) method as a phosphatidylcholine hydroperoxide value(PCOOH) in liver tissues. $CCl_4$ treatment significantly(p<0.05) resulted in an increase in GPT & GOT activities and liver hydroperoxide values comparing with those of the untreated control, while administration of PRC to the $CCl_4-treated$ rats significantly(p<0.001) decreased GPT & GOT activities and liver hydroperoxide value. Their ultrastructual changes of hepatocellular organelles were shown to clarify the morphologic nature of protective effects of PRC on hepatocytic injuries. $CCl_4$ treatment observed to change the ultrastructual nature of outer membrane of hepatocytes. However, the hepatic changes on PRC treatment to $CCl_4$ group was not found. PRC administration may inhibit the formatiion of liver lipid hydroperoxides in vivo and were very effective in recovering the liver function in $CCl_4-treated$ rats.

• Composites Research
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• v.34 no.6
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• pp.406-411
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• 2021

PEM (proton exchange membrane) fuel cells generate only water as a by-product, and thus are in the spotlight as an eco-friendly energy source. Among the various components composing the stack of the fuel cell, research on the bipolar plate that determines the efficiency of the fuel cell is being actively conducted. The composite bipolar plate has high strength, rigidity and corrosion resistance, but has the disadvantage of having a relatively low electrical conductivity. In this study, to overcome these shortcomings, a gas diffusion layer (GDL)-composite bipolar plate assembly was developed and its performance was experimentally verified. The graphite foil coating method developed in the previous study was applied to reduce the contact resistance between the bipolar plate and the GDL. In addition, in order to improve electron path in the stack and minimize the contact resistance between the GDL and the bipolar plate, a GDL-bipolar plate assembly was fabricated using a thin metal foil. As a result of the experiment, it was confirmed that the developed GDL-bipolar plate assembly had 98% lower electrical resistance compared to the conventional composite bipolar plate.