티타늄지지체에 β - PbO2 의 전착 및 성능에 관한 Cyclic Voltammograms

김재관,이충영,남종우 ( Jae Kwan Kim,Chung Young Lee,Chong Woo Nam ) 한국화학공학회 1993 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.31 No.6

As a basic study on the electrodeposition of PbO₂ with high oxygen overvoltage and less comsumption on a titanium substrate, the optimal electrodeposition conditions and electrode characteristics were investigated by cyclic voltammograms. It was observed that the electrodeposition condition was optimal at 1.0 M Pb(NO₃)₂, pH 2.2-3.0, 60℃, and anode potential, 1.50-1.65 V vs. SCE. The PbO₂ electrodeposition reaction was the diffusion controlled reaction that the fast the electrodeposition rate, the larger the grains size and the higher the oxygen overvoltage. Among various acids and organic additives used in this experiment, PbO₂ with a high oxygen overvoltage was electrodeposited when sodium lauryl sulfate was added in HClO₄ supporting electrolyte. Electrode performance and durability for the electrolytic preparation of sodium perchlorate from sodium chlorate with using lead dioxide electrodes electrodeposited on a titanium madras at above optimal electrodeposition conditions have been investigated. It was ascertained that the PbO₂ electrode electrodeposited by adding sodium lauryl sulfate in HClO₄ supporting electrolyte have the highest current efficiency and durability.

높은 산소과전압과 내구성의 이산화납전극 제조에 관한 연구

김재관,최병선,남종우 ( Jae Kwan Kim,Byun Sun Choi,Chong Woo Nam ) 한국공업화학회 1996 공업화학 Vol.7 No.6

α-pbO₂/IrO₂-TiO₂/Ti지지체상에 sodium lauryl sulfate 및 TiO₂ 분말을 첨가한 질산납 전해액에서 전착한 β-PbO₂층의 특성 및 성능을 XRD, SEM, cyclic voltammograms, 매크로전해를 이용하여 검토하였다. XRD분석결과 sodium lauryl sulfate 및 TiO₂분말의 존재하에 α-pbO₂/IrO₂-TiO₂/Ti지지체 위에 전착한 β-PbO₂층은 순수한 β-PbO₂층과 마찬가지로 정방정계구조를 나타냈다. SEM결과 sodium lauryl sulfate는 전착충의 결정입자크기를 작게 하는 경향을 보여준다. sodium lauryl sulfate 및 TiO₂분말의 존재하에 전착한 β-PbO₂전극은 KOH 및 HClO₄지지전해질에서 양극산화에 대한 산소과전압과 내구성을 크게 향상시켰다. 티타늄마드래스에 전착시킨 β-PbO₂전극을 이용하여 과염소산용액으로부터 오존발생에 대한 전극성능과 내구성을 검토하였다. HClO₄지지전해질에 sodium lauryl sulfate와 TiO₂분말을 첨가하여 α-pbO₂/IrO₂-TiO₂/Ti마드래스상에 전착한β-PbO₂전극이 가장 높은 전류효율과 내구성을 가짐을 확인하였다. The characteristic and performance of β-PbO₂ layer electrodeposited on α-PbO₂/IrO₂-TiO₂/Ti substrate by adding sodium lauryl sulfate and TiO₂powder in lead nitrate solution were investigated by using XRD, SEM, cyclic voltammograms, and macro-elctrolysis. Results of XRD analysis ascertain that β-PbO₂ layers electrodeposited in the presence of sodium lauryl sulfate and TiO₂powder on α-PbO₂/IrO₂-TiO₂/Ti substrate have the same tetragonal structure as pure β-PbO₂ layers. The SEM results show that sodium lauryl sulfate tend to diminish crystal size of the deposited layer. The β-PbO₂ electrode electrodeposited in the presence of sodium lauryl sulfate and TiO₂powder gives significantly improved oxygen overvoltage and durability for anodic oxidation in KOH and HClO₄supporting electrolyte. Electrode performance and durability for the evolution of ozone in perchloric acid solution have been investigated by using β-PbO₂ electrodes electrodeposited on Titanium madras^ . It was ascertained that the PbO₂ electrode electrodeposited on α-PbO₂/IrO₂-TiO₂/Ti madras^ by adding sodium lauryl sulfate and TiO₂ powder in HClO₄ supporting electrolyte had the highest current efficiency and durability.

추계학적 선진원 모델과 층상반무한체에서의 탄성파 전파 해석법에 의한 지진 지반운동 합성

김재관,권기준,KIM, Jae Kwan,KWON, Ki Jun 한국강구조학회 1996 韓國鋼構造學會 論文集 Vol.8 No.3

A Stochastic line source model is developed to simulate the seismic wave field generated during the rupture propagation process along a fault plane of which length is much larger than its width. The fault plane is assumed to consist of randomly distributed slip zones and barriers and each slip zone is modeled as a point source. By combining the newly developed source model with wave propagation analysis method in a layered 3-D visco-elastic half space, synthetic seismograms are obtained. The calculated accelerograms due to vertical dip slip and strike slip line sources are presented.

전착 이산화납전극의 제조 및 특성에 관한 연구

김재관,이충영,남종우 ( Jae Kwan Kim,Chung Young Lee,Chong Woo Nam ) 한국공업화학회 1993 공업화학 Vol.4 No.2

티타늄마드래스 소지에 PbO_2를 전착하는 과정에서 전해액에 여러 가지 산과 유기물질의 첨가는 PbO_2전착층의 물성에 큰 영향을 준다. XRD결과 β-PbO_2가 산성 전해액에서 전착되는 것을 확인하였다. 본 실험에서 사용된 첨가제 중 전해액에 sodium louryl sulfate를 첨가할때 산소과전압이 가장 높은 PbO_2가 전착되었으며 polyethylene glycol을 첨가할때는 염소과전압이 가장 낮은 PbO_2가 전착되었다. PbO_2의 산소과전압과 염소과전압은 PbO_2를 전착하는 동안 행하는 교반에 크게 의존한다. SEM결과 전착하는 동안 교만하지 않고 전착한 PbO_2결정이 교반하여 전착한 PbO_2보다 더욱 크다는 것을 관찰하였다. 또한 산성전해액에서 PbO_2를 전착할 경우, PbO_2결정 크기가 클수록 산소과전압은 커지며 PbO_2결정 크기가 작을수록 염소과전압은 낮아졌다. HClO_4의 존재하에서 PbO_2를 전착할 경우 560g/1 Pb(NO_3)_2, 65∼70℃, pH>1에서 최적의 전착전류효율을 나타내었다. Addition of various acids or organic compounds to the electrolyte solution during the electrodeposition of PbO_2 on titanium madras substrate strongly affected performance of the deposited PbO_2 layer. Results of X-ray diffractometry ascertained that β-PbO_2 was deposited in acidic electrolyte. Among additives used in this experiment, PbO_2 with a high oxygen overvoltage was electrodeposited when sodium lauryl sulfate was added, and PbO_2 with a lower chlorine overvoltage was electrodeposited when polyethylene glycol was added to the electrolyte solution. The oxygen and chlorine overvoltage of PbO_2 was strongly dependent on the stirring provided during the electrodeposition experiment. It was observed by the SEM results that the PbO_2 grains deposited when stirring was not provided during the electrodeposition have larger than PbO_2 grains deposited by stirring. In the PbO_2 deposition under acidic electrolyte, the oxygen overvoltage increased with larger PbO_2 grains and the chlorine overvoltage decreased with smaller PbO_2 grains. The optimal current efficiency of PbO_2 in the presence of perchloric acid was observed at Pb(NO_3)_2, 560g/1, 65∼70℃, and pH>1.

석탄회 중 미연탄소의 분리에 관한 연구

김재관,조희찬,최병선 ( Jae Kwan Kim,Hee Chan Cho,Byung Sun Choi ) 한국공업화학회 1997 응용화학 Vol.1 No.1

KEPRI is conducting a project for the separation of unburned carbon from fly ash with an objective of constructing a 30t/h commercial plant. To develop a separation scheme, fly ashes were collected from various power plants and analyzed for their physical characteristics. It was found that coarse fly particles were carbon rich and removal of these particles from bulk fly ash could reduce the LOI content to less than 3% at a yield over 70%. For this purpose, a sepecial type of cyclone with guide vanes was built to separate the coarse fly ash particles. Test results showed that a sample of fly ash with 6.0% LOI could be processed into a product containing 3.0% LOI. Generally though, the results were not as good as expected due to the inefficent size saparation and more importantly due to the break-up of the coarse carbon rich particles. Therefore, an additional measure is being taken to enhance the separation by incorporating the electrostatic forces.

BetaConcpet 프로그램: 2 차원 평면의 Voronoi diagram, 쌍대구조 그리고 콤플렉스

김재관(Jae-Kwan Kim),이목원(Mokwon Lee),차제현(Jehyun Cha),송찬영(Youngsong Song),조영송(Youngsong Cho),유중현(Joonghyun Ryu),김덕수(Deok-Soo Kim) (사)한국CDE학회 2014 한국 CAD/CAM 학회 학술발표회 논문집 Vol.2014 No.8

Voronoi diagrams are powerful for solving spatial problems among particles with different sizes.Voronoi diagram of atoms has proven its power for solving various fields of different disciplines, particularly molecular biology/material science problems, in an unified framework. Beta-complex is a generalization of alpha-complex and they share similarities and dissimilarities. This paper presents the BetaConcept program which facilitates easy understanding of the powerful capability of the Voronoi diagram, its dual structure, and the beta-complex in the plane. BetaConcept is a Windows program with a graphic user interface written in the standard C++ language and is freely available at the Voronoi Diagram Research Center (http://voronoi.hanyang.ac.kr).

현대화 과정의 중국특색적 민주주의에 대한 비판적 검토

김재관(Kim, Jae-Kwan) 전남대학교 5.18연구소 2012 민주주의와 인권 Vol.12 No.3

자동차 시뮬레이터를 위한 사이버 물리 라이더 센서 모델

김재관(Jae-Kwan Kim),김시호(Shiho Kim) 대한전자공학회 2015 대한전자공학회 학술대회 Vol.2015 No.6

민코 아역청탄의 순산소 연소특성

김재관(Jae-Kwan Kim),이현동(Hyun-Dong Lee),장석원(Seok-Won Jang),김성철(Sung-Chul Kim) 한국연소학회 2009 한국연소학회지 Vol.14 No.2

New way to effectively capture CO₂ in coal fired power plant is the combustion of coal using oxy-fuel technology. Combustion characteristics of Minco sub-bituminous coal at oxy-fuel conditions using TGA and drop tube furnace (DTF) were included activation energy about the char burnout, volatile yield and combustion efficiency of raw coal, the porosity of pyrolyzed char and fusion temperature of by-product ash. TGA result shows that the effect of CO₂ on combustion kinetics reduces activation energy by approximately 7 kJ/㏖ at air oxygen level(21% O₂) and decreases the burning time by approximately 16%. The results from DTF indicated similar combustion efficiency under O₂/CO₂ and O₂/N₂ atmospheres for equivalent O₂ concentration whereas high combustion efficiency under O₂/N₂ than O₂/CO₂ was obtained for high temperature of more than 1,100℃. Overall coal burning rate under O₂/CO₂ is decreased due to the lower rate of oxygen diffusion into coal surface through the CO₂ rich boundary layer. By-product ash produced under O₂/CO₂ and O₂/N₂ was similar IDT in irrelevant to O₂ concentration and atmospheres gas during the coal combustion.

RC 다주교각의 철근상세에 따른 내진성능 평가

김재관(KIM, Jae Kwan),김익현(KIM, Ick Hyun),김정한(KIM, Jung Han),조대현(CHO, Dae Yeon) 한국콘크리트학회 2002 한국콘크리트학회 학술대회 논문집 Vol.2002 No.5