• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2001년도 유체기계 연구개발 발표회 논문집
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• pp.419-424
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• 2001

TCV(Temperature control valve by pressure compensation) controls temperature constantly, when it is sending steam or high temperature water to heating device of heat exchanger. For designing TCV, the ratio of piston and hole diameters is one of the important design parameters. Numerical analysis is carried out to elucidate the flow characteristics in the TCV with different port areas of cold and hot waters, using the k-$\epsilon$ turbulence model and Cartesian cut-cell method. Numerical results show that the exit flow rate is mainly affected by pressure distribution in the piston.

• 한국정밀공학회지
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• 제22권5호
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• pp.138-143
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• 2005

Recently, automobile manufacturers regarding stability, economic environmental-friendly problems by the development of automobile, environmental problem as designing the exhaust system. Increasingly strict environmental regulations to lower fuel consumption and reduce emission. Also to reduce the noise and the vibration of the automobile. According to develop variable type muffler, dual muffler and active intelligence exhaust system unit. Improvement in engine performance and fuel consumption rate demand information of pressure fraction and heat characteristics. To be able to determine these factor for we experiment on each case of exhaust system unit. In this study, how back pressure is distributed in flow-through in exhaust system and how to design exhaust system flexibleness, efficiency and combustion charateristics influenced by back pressure. This study furnish basic data for engineers, technicians.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1995년도 춘계학술대회논문집
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• pp.131-144
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• 1995

This paper presetns modifications of a hydraulic shovel to robotize, and we derive a dynamic model of the hydraulic shovel arms,and hydraulic analysis are discussed . Then , our purpose is making to imitate a target railroad line of the grinder position by the PID control. Moreover, to determine the gains of the PId controller, we referenced the Ziegler and Nichols' method. In this paper, we demonstrated that the PID control is available for system. These results indicated the possibility of practical use fo the deburring robot with the hydraulic shovel.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1992년도 하계학술대회 논문집 B
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• pp.809-812
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• 1992

Charateristics of the ECR etch were Investigated about $MoSi_2$ layer which is widely used for the capping layer and barrier layer in VLSI metallization. The etch rate was evaluated according to gas ratio of $SF_6/BCl_3$, $N_2$ flow rate, RF power and chamber pressure. The chamber pressure, the most important factor, represented the maximum etch rate at about the pressure of 10 mTorr.

• 설비공학논문집
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• 제12권2호
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• pp.150-160
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• 2000

Turbulent natural convective flow and heat transfer in a square enclosure with horizontal partition are investigated numerically. The enclosure is composed of a lower hot and a upper cold horizontal walls and adiabatic vertical walls. Partitions carried with the upward, downward, and both control plates are attached perpendicularly to the one of the vertical insulated walls, respectively. The low Reynolds number $k-\varepsilon$ model is adopted to calculate the turbulent thermal convection. The governing equations are solved by using the finite element method with Galerkin method. The computations have been carried out by varying the length of partition, the position of control plates, and the Rayleigh number based on the temperature difference between two horizontal walls and the enclosure height for water(Pr=4.95). When the control plates are attached at the edge of partition, the stability of oscillating flow grows wrose with the increase of Rayleigh number and the partition length. The heat transfer rate has been reducer than that of no control plate due to the restraint of control plates with the increase of Rayleigh number.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 추계학술발표대회 및 bio-venture fair
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• pp.630-631
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• 2000

지방산과 당의 transesterification에 의하여 제조되는 당에스테르를 분리정제하는 방법으로 크로마토그라피방법을 조사하였다. 당에스테르제조에 사용되고 있는 각종 지방산(oleic, stearic, palmitic acid)과 당에스테르의 크로마토그라피 용출특성을 이동상의 유속과 온도, 그리고 주입량을 변화시켜 관찰하였다. 본 실험에서 사용한 column은 Silica 계통의$C_{18}$ column($3.9{\times}300mm$) 이었으며 본 실험에서 조사한 지방산과 당에스테르의 혼합물은 모두 높은 해상도로 분리되는 것을 관찰하였다.

• 한국물환경학회지
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• 제25권4호
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• pp.568-572
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• 2009

The adsorption characteristics of tartrazine by granular activated carbon were experimentaly investigated in the batch adsorber and the packed column. The adsorptivity of activated carbon for tartrazine was largely improved by pH control, and 98 percent of initial concentration could be removed at pH 3. It was estabilished that the adsorption equilibrium of tartrazine on granular activated carbon was sucessfully fitted by Freundlich isotherm equation in the concentration range from 50 mg/L to 1,000 mg/L. The characteristics of breakthrough curve of activated carbon packed column, which depend on the design variables such as initial concentration, bed height, and flow rate, were studied.

• 대한의용생체공학회:의공학회지
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• 제13권3호
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• pp.225-234
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• 1992

In order to use a low cost polymer valve in our total artificial heart and ventricular assist device, we have developed a slit-type bileaflet polymer valve[BPV 1. The aim of this study is to determine the hydrodynamic effectiveness of the newly-designed BPV and its feasibility for temporary use in the blood pumps. For hydrodynamic comparison, we investigated in-vitro the pressure drop across the valve, the leakage volume, the flow rate and the flow pattern of the BPV, two mechanical valves and a trileaflet polymer valve. We employed the ventriculo-pulmonary bypassing method for in-vivo tests of the BPV's together vilh our electrohydraulic left venIn ricular assist device in mongrel dogs. The BPV showed adquate gydrodynamic performances and in the preliminary animal bests, there was no xvi dence of thrombus formation on the valve leaflets and around the struts. Detailed results obtained from the animal tests will be separately reported. This report involves the design criteria, fabrication and hydrodynamic charateristics of she BPV, and the basic merits and demerits of the valve are dis- cussed from the hydrodynamic point of view.

• 대한환경공학회지
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• 제31권7호
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• pp.499-504
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• 2009

Erythrosine은 식용색소와 염료로 사용되지만 독성 때문에 미국에서는 거의 사용되지 않는 물질이다. 본 연구에서는 입상활성탄에 의한 erythrosine의 흡착특성을 회분식 및 흡착칼럼실험을 통하여 조사하였다. erythrosine에 대한 활성탄의 흡착능은 pH조절에 의해 크게 개선되었으며 pH 11에서 초기농도 1,000 mg/L의 98%를 제거할 수 있었다. 회분식흡착실험을 통해 흡착등온선을 구한 결과 erythrosine의 평형흡착관계는 10~1,000 mg/L의 농도범위에서 Freundlich식이 잘 적용되었다. 고정층 실험을 통하여 얻은 파과곡선으로부터 초기유입농도, 유입속도, 충전층의 높이가 흡착탑 운전에 중요한 설계변수가 될 수 있음을 알았다.

• 대한환경공학회지
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• 제39권5호
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• pp.277-281
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• 2017

최근 강우는 짧은 시간에 많은 비가 오는 특성을 자주 나타낸다. 이런 기상현상 때문에, 초기유출수와 합류식하수관거 월류수의 유입유량과 농도도 변화되고 있다. 이와 같이 유입조건이 변동되는 경우에는, 높은 수면적부하율을 가지는 부상방법이 공공수역의 수질관리에 적합하다. 왜냐하면 부상법은 공공수계의 요구조건을 충족 할 수 있기 때문이다. 현재까지 이러한 부상법의 검증과 진단을 위하여, 공급공기량과 유입SS량의 비율을 반영하여 왔다. 그러나 불행하게도 이러한 방식은 기술진단과 검증을 위한 판단기준으로는 그 한계를 가진다. 왜냐하면 부상속도와 시간요소가 상이한 버블분포에 의해 달라지기 때문이다. 부상속도와 시간은 처리시설의 용량에 영향을 준다. 왜냐하면 시간인자가 시설의 규모를 결정하기 때문이다. 그러므로, 동일한 공급공기량과 유입SS농도간 비율조건에서의 버블분포특성과 부상시간특성을 운영 및 기술진단 및 평가를 위한 판단기준으로 적용하여야만 한다. 따라서 이러한 필요에 따라, 이 논문 내용은 버블분포와 부상시간간 관계의 분석에 대한 실증적 일반화에 관한 연구이다.