분사법에 의한 탄산칼슘 제조

신보철,한상오,김주호,송지훈,송근호,이광래 강원대학교 석재복합신소재제품연구센터 2001 석재연 논문집 Vol.6 No.-

본 연구는 탄산가스화법에 의한 탄산칼슘 입자 제조 공정에 있어서, 탄산가스로 채워진 반응기에 수산화칼슘 슬러리를 분사하는 방법으로 탄산칼슘 입자를 제조하였다. 수산화 칼슘의 농도(0.25~1.0wt%), 분사압력(0.5kgf /㎠~1.5kgf /㎠) 및 반응기 온도(20℃, 28℃)의 변화에 따른 생성된 탄산칼슘을 관찰하였다. 수산화 칼슘의 농도가 비교적 높으면(0.75wt%, 1.0wt%), 생성물의 pH와 전도도는 높게 나타났다. 분사압력에 의한 탄산칼슘 제조의 변화는 분사압력이 높아질수록(1.5kgf /㎠), pH와 전도도는 높게 측정되었다. 그러나, 수산화 칼슘의 농도와 분사압력의 변화가 탄산칼슘의 입자크기, 형태, 결정구조에 영향을 미치지는 않았다. 반응기의 온도가 28℃에서 생성된 탄산칼슘은 1.0㎛이하의 칼사이트 상 입자가 제조되었으며, 20℃에서 생성된 탄산칼슘은 0.5㎛이하의 칼사이트 상 입자가 제조되었다. 반응기의 온도가 낮아질수록 탄산칼슘 입자의 크기가 작아짐을 알 수 있었다. For the preparation of calcium carbonate particles from aqueous Ca(OH)2 slurry, carbonation reaction of aqueous Ca(OH)2 slurry was carried out by spouting the aqueous slurry of Ca(OH)2 into reactor filled with CO2 gas. The concentration of Ca(OH)2 varies from 0.25wt% to 1.0wt%, nozzle pressure from 0.5kgf /㎠ to 1.5kgf /㎠, and reactor temperature were set at 20℃ and 28℃. With relatively high concentration of 0.75wt% and 1.0wt% of Ca(OH)2, pH and conductivity of product-stream were observed high value. High pH and conductivity were observed at high nozzle pressure of 1.5kgf /㎠. The concentration of Ca(OH)2 and nozzle pressure, however, did not change the particle size and shape of calcium carbonate synthesized by carbonation reaction. The reaction temperature affected particle size. At reactor temperatures of 28℃ and 20℃, the particle sizes were about 1.0㎛ and 0.5㎛, respectively. Crystal structure of calcium calcium carbonate was of calcite. When reactor temperature was lower, the size of calcium carbonate particle was smaller.

회분식 반응기에서의 공정변수 변화에 의한 침강성 탄산칼슘 제조

신보철,한상오,김주호,송지훈,송근호,이광래 江原大學校 産業技術硏究所 2001 産業技術硏究 Vol.21 No.B

For the preparation of calcium carbonate particles from aqueous Ca(OH)2 slurry, carbonation reaction of aqueous Ca(OH)2 slurry was carried out by batch method the CO2 into reactor filled with aqueous slurry of Ca(OH)2. The concentration of Ca(OH)2 varies from 1.00 to 7.00wt%, reactor temperature at 20 and 40℃, and reactor pressure from atmospheric pressure to 6.0kgf/cm2. Crystal structure of calcium carbonate was of calcite, the particle size were about 0.05 ∼2.0㎛, and the particle shape was cubic and spindle. When reactor temperature was higher, particle size of calcium carbonate was bigger and particle share was varied, but reaction rate was increased. When reactor pressure was higher, particle size of calcium carbonate was smaller, particle shape was cubic, and reaction ramie was increased.

마이크로 프로세서에 의한 가변속 유도전동기의 새로운 PWM 제어법

吳性寶,金一煥 제주대학교 1988 논문집 Vol.27 No.-

A new speed control apporach for ac motor drives which uses programmed PWM Switching pat-tern over the complete range of output speed is presented. The proposed scheme provides smooth operation during the required Switching pattern changing transitions and qurantess high quality output voltage and current in the ac motor load, therefore, most suitable for high performance, high efficiency applications. A detailed description of the scheme along with the realization aspect is described. Experimental investigation on a variable drive system illustrate the predicted advantages of the proposed scheme.

브러쉬리스 직류전동기의 코깅 토오크 비교해석

오성보 濟州大學校 工科大學 産業技術硏究所 1990 産業技術硏究報告 Vol.1 No.-

This thesis describes a study on cogging torque comparative analysis of brushless DC motor, which is one of torque ripple. These features have made brushless DC motors as one of the best choices which replace conventional brush-type DC motors in servo and robotics application. A cogging torque among the torque ripple in brushless DC motors is mainly due to the fluctuations of the field distribution which depends on the motor structure. The purpose of this thesis is to develop mathematical analysis and the experimental method of torque capable of accurately predicting the cogging torque. In this thesis. two methods which enable us to predict the amount of cogging torque are presented. One is the mathematical analysis using the analytic solution of flux density. The second is the experimental method which measures cogging torque in order to compare the mathematical analysis. When the two methods are compared with each other, a good agreement is obtained. Therefore, using the above methods, we can predict the cogging torque without manufacturing the motor, and we can use the above method to design the various type brushless DC motors.

브러쉬없는 직류전동기의 디지탈 속도제어

오성보 濟州大學校工科大學産業技術硏究所 1995 尖端技術硏究所論文集 Vol.6 No.-

Digital speed control of brushless DC motor is one of the attractive and interesting research subjects in the field of industrial robot. A direct-drive(D-D) system is being developed to control the forces and the high speed and the constant speed. The PI control without any additional control process has very poor response and inaccuracy of speed. It is one of the important problems to reduce the speed fluctuation caused by the arm weight. In order to improve those problems, we proposed a repetitive control for the constant speed by learning process. It provides us the good response of system and the improvement of speed accuracy.

난소 기형종에 동반된 직장후방 기형종

오보영,이령아,구혜수,문혜성 이화여자대학교 의과학연구소 2012 EMJ (Ewha medical journal) Vol.35 No.2

소득작물 전후작지 적응 극단기성 벼 ‘중모 1032’

손영보,이종희,조준현,이지윤,오성환,송유천,박동수,박노봉,김상열,여운상,남민희,권영업 忠北大學校 農業科學硏究所 2015 農業科學硏究 Vol.31 No.2

점토광물을 이용한 산소환원의 전기화학적 촉매성에 관한 연구

오성훈,황진연,심윤보,이효민,윤지해 한국광물학회 2005 광물과 암석 (J.Miner.Soc.Korea) Vol.18 No.1

몇 가지 점토광물과 메틸바이올로젠 또는 메틸렌블루를 함유시킨 점토수식전극을 이용하여 산소환원에 대한 전기화학적 촉매성을 검토하였다. 점토광물로는 Na-몬모릴로나이트, Ca-몬모릴로나이트, 카오리나이트를 사용하였다. 점토수식전극은 유리탄소전극 표면에 점토 현탁액을 입히고 메틸바이올로젠을 흡착시킨 것을 사용하였으며, 전기화학적 산소환원의 정도는 순환 전압전류(cyclic voltammetry)으로 측정하였다. 실험결과, 다른 점토시료에 비하여 Na-몬모릴로나이트가 메틸바이올로젠의 흡착효과가 가장 크게 나타났고, 메틸바이올로젠을 흡착시킨 점토수식전극이 산소환원에 대한 촉매성이 월등히 우수하였다. 즉 촉매산소환원 피크가 242.6 ㎷ 만큼 +방향으로 이동하였다. 메틸바이올로젠을 흡착시킨 점토수식전극이 메틸렌블루를 흡착시킨 점토수식전극보다 산소환원에 대한 촉매성이 더 높게 나타났다. Ca-몬모릴로나이트의 경우는 변화가 없었으나 Na-몬모릴로나이트의 구조는 메틸바이올로젠의 흡착으로 변화되었다. 메틸바이올로젠- Na-몬모릴로나이트 점토수식전극을 현탁액의 점토 농도가 약 0.87 g/10 mL이고, 메틸바이올로젠의 수용액의 농도가 대략 2.5 mM일 때 산소환원 촉매 효과가 가장 탁월하였다. 지지전해질의 pH에 따른 점토수식 전극의 산소 환원 촉매성은 중성의 pH 범위(6.3과 8.3)에서보다 산성인 pH 3.7과 알칼리성인 pH12.7에서 월등히 크게 나타났다. The electrocatalytic reduction of O₂ was investigated with methyl viologen and methylene blue incorporated clay-modified electrodes. Clay suspensions were prepared with Namontmorillonite, Ca-montmorillonite, and kaolinite. The methyl viologen-clay modified electrodes were made by coating clay suspensions adsorbing methyl viologen on a glassy carbon electrode. Cyclic voltammetry were performed in aqueous media to investigate the electrocatalytic property of the modified electrode in reducing O₂. A Na-montmorillonite modified electrode showed the greatest adsorption capacity for methyl viologen. The modified electrode made of Na-montmorillonite suspension of 0.87 g/l0 mL and a 2.5 mM of methyl viologen solution showed the most effective electrocatalytic property, where the catalytic reduction potential was shifted by 242.6 ㎷ toward the positive potential. The electrocatalytic ability was more significant in acidic (pH=3.7) and alkaline (pH=12.7) media than the neutral pH range (6.3~8.3). The methyl viologen-Na-montmorillonite modified electrode had the good reproducibility and maintain the electrocatalytic property over 20 times reuse.

브러쉬리스 直流電動機의 코깅 토오크 比較解析

吳性寶 濟州大學校工科大學附屬産業技術硏究所 1990 尖端技術硏究所論文集 Vol.1 No.-

본 연구에서는 영구자석 브러쉬리스 직류전동기의 코깅 토오크를 해석하기 위하여 수학적 해석과 실험에 의한 방법을 사용하였는데 일반적으로 실험적 해석 방법은 적용범위가 국한되어 아주 미세한 코깅 토오크를 정확하게 측정하는 것이 어렵다. 그 이유는 코깅 토오크를 측정하고자 하는 전동기의 정격속도의 약 1퍼센트 정도의 극저속으로 돌려져 측정하고자 하는 전동기가 외부 구동전동기에 정확하게 일직선 상에 놓여 있는 상태에서 디지탈 측정기로 측정하여야 한다. 그러나 이때 아주 미세한 마찰이 존재하면 코깅 토오크를 정확하게 측정하는 것이 어렵기 때문에 실제 전동기를 설계하는 과정에서는 적용하기가 어려우므로 전동기 설계시 이 방법에 의한 설계를 한다는 것이 불합리함을 알 수 있었다. 따라서 본 연구에서는 수학적해석에 의한 방법을 제시하여 실험에 의한 방법과 정량적으로 잘 일치함을 알 수 있기 때문에 이방법을 이용하여 여러가지 형태의 새로운 영구자석 브러쉬리스 직류전동기 설계에 있어 코깅 토오크의 정밀해석에 유효할 것으로 사료된다. This thesis describes a study on cogging torque comparative analysis of brushless DC motor, which is one of torque ripple. These features have made brushless DC motors as one of the best choices which replace conventional brush-type DC motors in servo and robotics application. A cogging torque among the torque ripple in brushless DC motors is mainly due to the fluctuations of the field distribution which depends on the motor structure. The purpose of this thesis is to develop mathematical analysis and the experimental method of torque capable of accurately predicting the cogging torque. In this thesis, two methods which enable us to predict the amount of cogging torque are presented. One is the mathematical analysis using the analytic solution of flux density. The second is the experimental method which measures cogging torque in order to compare the mathematical analysis. When the two methods are compared with each other, a good agreement is obtained. Therefore, using the above methods, we can predict the cogging torque without manufacturing the motor, and we can use the above method to design the various type brushless DC motors.

반파정류브러쉬없는 동기전동기의 디지탈 위치제어

오성보 濟州大學校 工科大學 産業技術硏究所 1994 産業技術硏究報告 Vol.5 No.-

Digital position control of brushless synchronous motor is one of the attractive and interesting research subjects in the field of industrial robot. A direct - drive (D-D) system is being developed to control the forces and position of high speed and high accuracy. The PI control without any additional control process has very poor response and inac-curacy of position. In order to improve those problem, We proposed a repetitive control with the position memory type, learning process. It provides us the good response of system and the improval of position accuracy.