• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집D
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• pp.945-949
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• 2001

This study is an experimental study on the characteristics of emission by changing catalytic converter position for cold-start. The measurements are done a changing of the distance between exhaust manifold and catalytic converter. It measured temperature of exhaust manifold, before and after catalytic converter at each position of experimental condition. and measured the characteristics of emission which is HC, CO, $CO_{2}$ and lambda at each position of experimental condition. The results show a few advantage about reduction of HC and CO as catalytic converter's temperature is raised quickly as closed exhaust manifold. but $CO_{2}$ has not the same trend of HC and CO. From measurement value of lambda, reduction effects of $NO_{x}$ are known a few advantage as increase of the distance between exhaust manifold and catalytic converter.

• 한국자동차공학회논문집
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• 제14권6호
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• pp.137-142
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• 2006

This research represents the catalytic converter for application in the motorcycle. Present research model type is monolithic catalytic converter and this type have been widely used for satisfaction on and the regulations of pollutant emissions in automobiles. The flow characteristics in a single monolith automotive catalytic converter were investigated by using a computational simulation method without chemical reaction. So we limit the discussion to the effect of flow uniformity in the catalytic converter. Simulation result shows that the flow uniformity of megaphone type catalytic converter is higher than that of a base type. Therefore, the megaphone type is more suitable to motorcycle.

• 한국자동차공학회논문집
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• 제15권5호
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• pp.63-71
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• 2007

The conversion efficiency, durability and pressure drop of the automotive exhaust catalysts are dependent on the flow distribution within the substrate. Conventional porous medium approaches assuming monolith resistance based on the one-dimensional laminar flow for simulating the flow through the automotive exhaust catalysts over-predict the flow uniformity in the monolith. In this study, additional pressure loss is also considered by accounting for entrance effects due to the oblique flow incident on the front face of monolith as a consequence of flow separation and recirculation within the diffuser. The incorporation of an additional pressure loss improves the predictions for the maximum flow velocity within the substrate. An numerical study has also been conducted for the three-dimensional unsteady incompressible non-reacting flow inside various dual-monolith catalytic converters for the rapid acceleration/deceleration driving.

• 한국자동차공학회논문집
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• 제6권4호
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• pp.108-120
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• 1998

A theoretical study of three-dimensional unsteady compressible non-reacting flow inside double flow of monolith catalytic converter system attached to 6-cylinder engine was performed for the achievement of performance improvement, reduction of light-off time, and longer service life by improving the flow distribution of pulsating exhaust gases. The differences between unsteady and steady-state flow were evaluated through the numerical computations. To obtains the boundary conditions to a numerical analysis, one dimensional non-steady gas dynamic calculation was also performed by using the method of characteristics in intake and exhaust system. Studies indicate that unsteady representation is necessary because pulsation of gas velocity may affect gas flow uniformity within the monolith. The simulation results also show that the level of flow maldistribution in the monolith heavily depends on curvature and angles of separation streamline of mixing pipe that homogenizes the exhaust gas from individual cylinders. It is also found that on dual flow converter systems, there is severe interactions of each pulsating exhaust gas flow and the length of mixing pipe and junction geometry influence greatly on the degree of flow distribution.

• 대한기계학회논문집B
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• 제23권7호
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• pp.841-855
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• 1999

In the present work, the effect of a flow maldistribution on the thermal and conversion response of 8 monolith catalytic converter is Investigated. To achieve this goal, a combined chemical reaction and multi-dimensional fluid dynamic mathematical model has been developed. The present results show that flow uniformity within the monolith brick has 8 great impact on light-off performance of the catalytic converter. In the case of lower flow uniformity, large portions of the monolith remain cold due to locally concentrated high velocities and CO, HC are unconverted during warm-up period, which loads to retardation of light-off. It has been also found that the heat-up pattern of the monolith ill similar to the flow distribution profile, In the early stage of the reaction. It may be concluded that flow maldistribution can cause a significant retardation of the light-off and hence can eventually worsen tho conversion efficiency of automotive catalytic converter.

• 한국자동차공학회논문집
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• 제7권7호
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• pp.187-194
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• 1999

In the design of catalytic converter, velocity distribution is more important than pressure drop because monolith pressure drop is about 80% of overall pressure drop. For the catalytic converter with single diffuser, pressure drop is decreased as the angle of diffuser decrease, but when the angle is below 18$^{\circ}$, the effect is almost negligible . For the catalytic converter with double diffuser, variation of the angle of the first diffuser shows the same trend as the pressure drop while the shape of diffuser gives little influence on that The outlet shape gives negligible effect on the pressure drop and velocity . distribution . Results show that recirculation region of commercial model is aoubt 30% of the total area in the front of monolith. For the catalytic converter with Model 11 that was presented in the study, recirculation region was not detected more uniform velocity distribution was obtained, and pressure drop was also decreased.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2015년도 제49회 하계 정기학술대회 초록집
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• pp.121.2-121.2
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• 2015

국내에서 생산되는 화강석 중 하나인 거창석은 대부분 회백색 계열이며 컬러석재의 경우 대부분 고가로 수입되어 판매가 되고 있다. 본 연구에서는 컬러 화강석 제조에 관한 연구를 수행하였다. 거창석 표면에 금속촉매를 도포 후 화강석 내부로 금속입자를 침투시킨 다음 열처리를 통해 거창석의 색을 영구히 변환 시키는 연구를 수행하였다. 금속촉매 침투시에 함수발생기(function generator)를 사용한 경우와 사용하지 않은 경우 시간에 따른 침투 깊이와 침투 현상의 차이를 분석하고 검정, 빨강, 갈색의 색상에 따른 침투깊이 차이 또한 비교하였다.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 2003년도 동계 학술대회 논문집
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• pp.209-214
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• 2003

바이오 센서는 생물학적 인식 반응(Biological recognition reaction)이나 생물 촉매 공정(Bio-catalytic process)을 측정 가능한 전기적 신호로 변환시켜주는 적절한 변환기(Transducer)와 같은 생물학적 인식요소로 이루어진 감지 장치를 의미한다. 1962년 효소를 이용한 Glucose 전극봉의 개발이후 이 분야에 대한 수많은 연구와 기기의 개발이 진행되어왔다. 분석도구로써 바이오 센서는 효소, 항체, 수용체, 세포, 조직 등과 같은 생물학적 인식 요소들에 광범위하게 적용 가능하다는 장점이 있는 반면, 위에 열거한 생물학적 인식 요소들의 불안정성으로 인해 신뢰성이 유지되지 못하는 단점을 동시에 지니고 있다. (중략)

• 대한기계학회논문집B
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• 제31권6호
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• pp.507-513
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• 2007

This study represents the temperature uniformity in catalytic converter. Present research model type is a monolithic catalytic converter. This type was been widely used for complying the regulations of pollutant emissions from automobiles. The mean experimental parameters are engine speed and ceramics monolith in the catalytic converter. The experimental test engine model used was the 124.1cc motorcycle engine. The experimental study using thermal imaging method shows the megaphone type model has larger effective area than the basic model. The rate of effective area in the basic model is about 8.9 % and the megaphone type model are 41.52 %, 34.60 %, 33.43 %, 25.43 %, 17.82 % according to the diffuser angle $4^{\circ}\;to\;8^{\circ}$. In conclusion, the megaphone type monolithic converter has higher efficiency of reducing the pollution with less noise compared to the basic shape. We believe this will be very important as a design guide of the advanced motorcycle.

• 한국자동차공학회논문집
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• 제15권4호
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• pp.108-114
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• 2007

This research represents the catalytic converter for application in the motorcycle. We have to consider about catalytic converter for reducing exhaust gas strength regarding the displacement volume enlargement. The catalytic converter has been widely used to satisfy the regulations of pollutant emissions from automobiles. Recently, all catalytic converter researches are about automobile. Study about motorcycle catalytic converter has not been conducted yet. In this study, flow uniformity and pressure distribution were simulated in the monolithic inlet of catalytic converter for motorcycle. Exhaust pulsation pressure was set as transient condition about. It was found that flow uniformity shown in base model (0.85) was lower than megaphone model (0.98).