이득기의 한방이제

이득기,Lee, Deuk-Gi 대한한약협회 2003 大韓漢藥 Vol.7 No.-

이산화탄소에 의한 CaO 탄산화 반응에서 기-고 반응 속도 모델

이득기,백일현 한국화학공학회 2003 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.41 No.6

무촉매 기-고 반응의 하나인 이산화탄소에 의한 CaO 탄산화 반응에 있어서 반응 모델식을 다음과 같이 제시하였다. X=kbt/(b+t), 여기서, X=CaO의 탄산화 전환율, k=반응속도 상수(time^(-1), b=CaO의 최종 전환율의 절반에 해당하는 전환율까지 탄산화가 진행되는 데 요구되는 시간 상수(time)이다. CaO의 탄산화 속도는 다음과 같이 유도되었다. dX/dt=k[b/(b+t)]². CaO 탄산화 반응에 있어서 탄산화 전환율에 따라 나타나는 반응 초기의 표면반응 속도제한 영역과 후기의 확산 속도제한 영역에서의 상수값 k 및 b를 각각 온도의 함수로 결정하였다. CaO의 최종 탄산화 전환율은 온도에 따라 달라지며, 제시된 모델에서는 두 상수 k와 b를 곱한 값에 해당하였다. 이와 같은 모델식을 사용하여 CaO 탄산화 거동을 잘 나타낼 수 있었다. For the kinetics of the carbonation reaction of calcium oxide by carbon dioxide, a model equation has been proposed as follows: X=kbt/(b+t), where, X=the mass fractional conversion of CaO, k=a kinetic rate constant (time^(-1)), b=a constant (time) corresponding to the time necessary for half the ultimate conversion of CaO, and t=tirne. The rate of carbonation reaction is expressed as dX/dt=k[b/(b+t)]². The constants k and b in the two regimes of CaO-conversion, surface chemical reaction control, and diffusion control. have been obtained as functions of temperature, respectively. Values of the ultimate conversion of CaO are dependent on temperature, and, in this model. given by the product of two constants. k and h. The CaO carbonation behavior has been well represented by this kinetic equation proposed.

바람직한 중등학교장의 수월성지도성 행동연구

이득기 한국교육행정학회 1994 敎育行政學硏究 Vol.12 No.3

Reaction pathway of the catalytic oxidation of aqueous ammonia to molecular nitrogen

이득기 한국화학공학회 2007 화학공학의이론과응용 Vol.10 No.1

Aqueous phase catalytic wet air oxidation of ammonia was studied over Ru/TiO2 catalyst in a batch reactor by changing the solution pH, concentration of catalyst in the solution, temperature, and reaction time. The oxidation reaction of ammonia over Ru/TiO2 catalyst was found to take place exclusively for the aqueous NH3 with a preferred mode in strong alkaline pH region. An oxidation reaction pathway was proposed as following: Oxidation of ammonia was initiated by the reaction of aqueous ammonia with catalytically activated oxygen. After undergoing further successive oxidation reactions with activated oxygen, ammonia was finally oxidized to a molecule of nitrous acid. Nitrous acid dissociates into a nitrite ion and a proton. The solution pH was decreased with the protons from the dissociation of HNO2 so that the solution concentration of NH4 + was increased. Molecular nitrogen as a final product was produced from the homogeneous aqueous phase reaction between ammonium ion and nitrous ion. Further reaction of nitrous ion with the activated oxygen led to the formation of nitrate ion as another final product.

비교교육의 연구방법 탐구와 적용연구:국제비교

이득기 한국비교교육학회 1997 比較敎育硏究 Vol.7 No.1

뉴 잉글랜드 교육사상에 미친 존 로크의 영향

이득기 한국교육과정학회 1987 교육과정연구 Vol.6 No.-

천연가스의 수증기-이산화탄소 복합개질용 촉매 충진 반응기의 코킹 회피 운전을 위한 모사

이득기,이상수,서동주,윤왕래 한국수소및신에너지학회 2015 한국수소 및 신에너지학회논문집 Vol.26 No.5

A tubular packed bed reactor for the steam-CO2 combined reforming of natural gas to produce the synthesis gas of a target H2/CO ratio 2.0 was simulated. The effects of the reactor dimension, the feed gas composition, and the gas feeding temperature upon the possibility of coke formation across the catalyst bed were investigated. For this purpose, 2-dimensional heterogeneous reactor model was used to determine the local gas concentrations and temperatures over the catalyst bed. The thermodynamic potential distribution of coke formation was determined by comparing the extent of reaction with the equilibrium constant given by the reaction, CH4+2CO ⇔3C+2H2O. The simulation showed that catalysts packed in the central region nearer the entrance of the reactor were more prone to coking because of the regional characteristics of lower temperature, lower concentration of H2O, and higher concentration of CO. With the higher feeding temperature, the feed gas composition of the increased H2O and correspondingly decreased CO2, or the decrease in the reactor diameter, the volume fraction of the catalyst bed subsequent to coking could be diminished. Throughout the simulation, reactor dimension and reaction condition for coking-free operation were suggested.

박사과정에 진학하며

이득기 대한전기학회 1998 전기의 세계 Vol.47 No.1

ZVS-FB PWM DC/DC 변환기의 동특성 해석 및 제어기 설계

이득기,윤길문,차영길,김흥근 전력전자학회 1998 전력전자학회 논문지 Vol.3 No.3

본 논문에서는 대용량에 적합한 영전압 스위칭 전브리지 PWM 직류/직류 변한기의 동특성 해석과 제어 루프의 설계에 대해 논하였다. 전압을 제어하기 위한 위상전이제어의 효과와 영전압 스위칭을 위한 변압기의 누설인덕턴스, FET의 적합 커패시턴스의 이용효과를 고려한 소신호 모델을 유도하였다. 이 소신호 모델은 PWM 벅 변환기의 등가모델에 시비율 변조에 대한 두 개의 종속 전원을 추가함으로써 모델링할 수 있다. 소신호 해석 결과를 근거로 하여 2-극점, 1-영점 보상회로를 사용한 전압제어기를 설계하였다. 설계된 제어기의 타당성을 검증하기 위해서 개루프 시스템과 폐루프 시스템의 소신호 해석결과를 비교하였으며, 2kW급 부하실험으로 설계한 전압제어기의 동특성이 우수함을 실험적으로 입증하였다. This paper presents the dynamic analysis and control loop design of a zero voltage switching full bridge (ZVS-FB) PWM DC/DC converter. The small-signal model is derived incorporating the effects of phase shift control and the utilization of transformer leakage inductance and power FET junction capacitance to achieve zero voltage resonant switching. These effects are modeled by introducing additional feedforward and feedback terms for duty cycle modulation. Based on the results of the small-signal analysis, the control loop is designed using a simple two-pole one-zero compensation circuit. To show the validity of the design procedures, the small signal analysis of the closed loop system is carried out and the potential of the zero voltage switching and the superiority of the dynamic characteristics are verified through the experiment with a 2 kW prototype converter.

Suspension culture of Vero cells for the production of adenovirus type 5

이득기,박지혜,서동원 대한백신학회 2020 Clinical and Experimental Vaccine Research Vol.9 No.1

Purpose: Most cell culture processes for viral vaccine production are mainly based on adherent cell culture systems using serum, which are associated with expensive and labor-intensive processes to produce large amounts of viral vaccine strains. In this study, we investigated whether Vero cells could be grown in serum-free and shaking suspension conditions. Furthermore, we assessed the ability of the Vero cell suspension culture system to produce adenovirus type 5 (Ad5), compared to that of the adhesive Vero cell culture system. Materials and Methods: We tested the feasibility of commercial serum-free media for Vero cell culture. For the adaptation of Vero cells in suspension culture, adhesive Vero cells were added in the early phase of shaking suspension culture, and 50 days after shaking suspension culture, suspension-adapted Vero cells were subcultured continuously. To assess the virus production ability of Vero cells in suspension, the cells were infected with Ad5-green fluorescent protein and evaluated based on their fluorescence intensity. Results: The Vero cells grown in OptiPRO serum-free medium showed no changes in morphology and growth rate, but MRC-5 and FRhk-4 cells showed morphological changes and decreased growth rate, respectively. The Vero cells were well adapted to the suspension culture system. The Vero cells in suspension showed a better Ad5 production ability than the adherent Vero cells. Conclusion: Vero cells can be grown in OptiPRO serum-free medium. Further, our suspension culture-adapted Vero cells may be suitable to produce viral vaccine strains due to their high ability to produce viruses such as Ad5.