전기화학적 방법을 이용한 저온형 연료전지용 고분산 Pt 촉매의 제조

윤봉국,최재식,김현수,임태훈,홍성안,이호인 한국공업화학회 2003 응용화학 Vol.7 No.2

Pt was deposited on carbon support by chronoamperometry. The catalytic activity for methanol oxidation was checked by CV (cyclic voltammetry) method. The amount of Pt loading was calculated by integration of I-t curve obtaining the total current used for the Pt deposition. The ECA (electrochemical active surface area) for loaded Pt was calculated from the hydrogen adsorption/desorption peaks in 0.5 M H₂SO₄solution. Pt was deposited on clean carbon electrode surface with various concentration of Pt solution (0.1 mM) was used. As the concentration of Pt increased, the specific catalystic activity of Pt decreased suggesting that, in the electrochemical reaction of Pt ion with electrode surface, Pt particles were smaller and more dispersed in low concentration of Pt solution. With this condition (0.1 mM Pt), Pt was electrodeposited on a commercial carbon support, Vulcan XC-72. Electrochemically loaded Pt catalyst had the higher ECA, and showed higher specific catalytic activity for mathanol oxidation than a commercial Pt/C catalyst.

강원도 사북-고한 지역의 석탄광 폐석에 대한 물리적, 역학적 특성 연구

임한욱,정윤영,목진호,김종훈,김재동,신동오 강원대학교 석재복합신소재제품연구센터 1996 석재연 논문집 Vol.1 No.-

석탄광 폐석의 건설용 골재로서 활용 가능성을 검토하기 위하여 폐석의 주요 구성암석인 사암, 사질혈암, 혈암, 탄질혈암을 대상으로 기초물성실험, 역학적 실험 및 골재원 특성 실험을 실시하였다. 시험결과치의 평균값을 기준으로 할 때 사암, 사질혈암, 혈암은 골재로서 활용이 가능하나, 실험치의 분산도가 심하여 활용가능 폐석과 불가능한 폐석이 혼재되 있음을 확인하였다. 반면에 탄질혈암은 골재원 특성이 가능하나 강도등 물성에서는 사용이 곤란한 것으로 판단되었다. 따라서 앞으로 폐석중 활용가능한 사암, 사질혈암 및 혈암을 효율적으로 분급하는 방안과 금번에 실시하지 못한 골재의 알카리 반응시험 등이 추가로 보완되었으면 한다. An experimental program was undertaken to test rock wastes from coal mines, for use as a new source of aggregate. Physical and mechanical properties, required for aggregate materials, of major constituents of rock wastes including sandstones, sandy shales, shales, and coal shales, were measured in the laboratory. Test results showed that the sandstones, sandy shales and shales tested in this study might possibly be used for construction aggregates, the highly scattered test data indicated considerable proportion of unusable rocks. In case of coal shales, the aggregate characteristics were generally adoptable but some physical properties such as rock strength were lower than required. In conclusion, it is suggested that an effective procedure for sorting the rock wastes, and additional tests such as alkali-aggregate reaction should be supplemented.

생체시료中 Morphine 및 Codeine의 분석

임미애,이종숙,김재균,박세연,성은연,구기서 內務部 國立科學搜査硏究所 1996 國立 科學 搜査 硏究所 年報 Vol.28 No.-

안면부 종창을 동반한 Henoch-Scho¨nlein 자반증 1례

이재휘,서무규,임문환,박성기,김태우,이창연 동국대학교 경주대학 1991 東國論集 Vol.10 No.-

We experienced a case of Henoch-Scho‥nlein purpura with are manifestation of facial swelling in a 7-year-old boy.

스캔 설계 법칙 검사에 관한 연구

이재훈,김형국,조경연,임동욱,민형복 成均館大學校 科學技術硏究所 1997 論文集 Vol.48 No.2

Since testing of digital circuit is becoming increasingly important, many methodologies have been introduced to enhance design for testability (DFT). DFT was taken into account in the automated test procedure and improved reliability of the design. Both tasks are well suited for scan rule checker. This paper presents a scan rule checker for gate level digital circuits. The scan rule checker deals with basic rule check, basic scan rule check, muxed scan rule check, clocked scan rule check and lssd. Scan design informations were represented in the configuration file and libraries were modeled for the scan rule checker. It is an efficient way for the design for testability methodology.

Cyclic 활성슬러지 공정을 이용한 돈사폐수의 영양소 제거특성

조용진,임재명,이호식 江原大學校 附設 環境硏究所 1999 環境硏究 Vol.16 No.-

The cyclic activated sludge process is a modified activated sludge using the sequencing batch reactor(SBR) operation that can achieve the combination of carbon oxidation and nutrient removal. The operational characteristics of cyclic activated sludge process include a time-sequenced operation of anaerobic/aerobic/anoxic condition in a single reactor to achieve a maximum efficiency. The application of cyclic activated sludge process is, however, usually focused on the low strength wastewater including domestic sewage. As a result, limited attention has given to the high strength wastewater, especially for the piggery wastewater. The primary objective of this study is to evaluate an optimum operational cyclic to achieve combination of organic and nutrient removal using the piggery wastewater. The factors affecting inhibitory effects on nitrification during the cyclic operation is further determined. The result of this study, optimum operational cyclic of activated sludge process is 1hr : 2hr A/O(anoxic/oxic) ratio. Also, It was efficient that the SRT is operated more than 10 days and the specific nitrification rates were 0.04~0.24 ㎎N/gMv/hr at 20℃. Nitrification inhibition of piggery wastewater was found to occur at an influent volumetric loading over 0.3 NH₄-N ㎏/㎥/d. After a biological treatment, remaining phosphorus removal experiments were executed in oxidized ferrous column. As a result, the experiment showed the high density of variation in concentration by contact time on air. As for column aeration, completely phosphorus removal time was 25 minutes in contact time on air(20 hr) with aeration and 400 minutes(w/aeration) and 580 minutes(w/o aeration) in contact time on air(0 hr) respectively.

STWS를 이용한 유도전동기의 토오크 전류측정용 관측기 설계에 관한 연구

심재선,임윤희,김민형 三陟大學校 1997 論文集 Vol.30 No.1

This paper propose a method, observer design for torque current measurement of induction motors, by using single term walsh series(STWS). If the torque currents of induction motors need to know for induction motors driving correctly, it is observed by proposed observer directly. Since the observer which is presented in this paper has an algebraic form, it is more attractive than the conservative others.

활성탄상의 heptafluoropropane 합성에서 반응온도의 효과

김재덕,이윤우,임종성,이경환,이윤용 社團法人 韓國火災 ·消防學會 1998 한국화재소방학회논문지 Vol.12 No.1

가스계 혼합소화약제의 불꽃소화농도

김재덕,임종성,이윤우,이윤용 한국화재소방학회 2001 한국화재소방학회논문지 Vol.15 No.1

가스계 혼합소화약제의 소화성능을 검토하기 위하여 Cup-burner test장치를 설치하고 이성분계 및 삼성분계 혼합물의 불꽃소화농도를 측정하였다. 시험대상 이성분계 혼합물은 이산화탄소/HFC-23, 이산화탄소/HCFC-22, 이산화탄소/HFC-227ea, 이산화탄소/HFC-125, 이산화탄소/FIC-13I1, Hexaflluoropropylene/HFC-23이고 삼성분계 혼합물은 이산화탄소/HFC-23/HFC-134a, 이산화탄소/HFC-23/HFC-227ea, 이산화탄소/HFC-23/HFC-125이다. Cup-burner test장치에서 측정된 가스계 혼합물의 소화농도는 단일성분의 소화농도와 혼합물의 구성비로 이루어진 모델에 의해 잘 예측됨을 알 수 있었다. 특히 이 모델은 혼합물의 구성성분이 물리적 소화성능을 지닐 때 잘 적용되며 화학적 소화성능의 영향이 강해질수록 측정값과의 오차가 커진다. Fire extinguishing efficiency of mixed gaseous agents were investigated by the cup-burner test and predicting by the model of flame extinguishing concentration. The binary mixed agents that tested were carbon dioxide/HFC-23, carbon dioxide/HCFC-22, carbon dionide/HFC-227ea, carbon dioxide/HFC-125, carbon dioxide/FIC-13I1, Hexafluoropropylene/HFC-23 and ternary mixed agents were carbon dioxide/HFC-23/HFC-134a, carbon dioxide/HFC-23/HFC-227ea, carbon dioxide/HFC-23/HFC-125. A model which contains the flame extinguishing concentration and composition of pure components predicted the flame extinguishing concentration of mixture well. This model was superior when each component of the mixture exhibit physical fire extinguishing performance.

터널내 자연환기력 변화에 따른 오염물질 거동특성

정태섭,임익현,유재연 全北大學校 附設 都市및環境硏究所 1997 都市 및 環境硏究 Vol.12 No.1

Because of a sudden increase of vehicles, the limit of road capacity occurred. We are, therefore, constructing the road tunnel over l㎞ for the maximization of land use. To supply safe driving conditions in the road tunnel, we are controlling the exhaust emissions with a forced ventilation facility. The purpose of this study is to investigate the ventilation efficiency and the characteristics of tunnel on the change of natural ventilation force. To carry out this study, Sola program is transformed to fit for the road tunnel and it was simulated. The tunnel with ventilation system of transverse type is used as a objective tunnel. The results of this study are as follows; 1. The larger a natual ventilation force, the better a ventilation efficiency. 2. It is required the ventilation system dealing with quickly a change of the tunnel surroundings because of accumulation of 5m/sec. 3. The contaminant distributions in the near of ventilation system are highly stagnant in the left-below parts of tunnel, the below parts of air supply system and the below parts of ventilation system.