스피넬형 양극활물질 LiMn₂O₄의 합성방법에 따른 전기화학적 특성 비교

이기수,방현주,선양국,Lee, Ki-Soo,Bang, Hyun-Joo,Sun, Yang-Kook 한국전기화학회 2007 한국전기화학회지 Vol.10 No.1

In order to investigate the effects of particle size and specific surface area(BET area) of spinel powder, $LiMn_2O_4$ were synthesized using metal oxide precursor by co-precipitation method(CoP) and solid state reaction (SSR) .X-ray diffraction(XRD) patterns revealed that the both prepared powder has a well developed spinel structure with Fd3m space group. The $LiMn_2O_4$ prepared by co-precipitation showed spherical morphology with narrow size distribution. However, the $LiMn_2O_4$ prepared by solid state reaction showed relatively smaller particles with irregular shape. The measured BET areas of the powers are $0.8m^2g^{-1}$ (CoP) and $3.6m^2g^{-1}$(SSR). The electrochemical performance of the Prepared $LiMn_2O_4$ powders was evaluated using coin type cells(CR2032) at elevated temperature ($55^{\circ}C$). The $LiMn_2O_4$ prepared by co-precipitation showed the better cycling performance(82.3%capacity retention at $50^{th}$ cycle) than that of the $LiMn_2O_4$(68.3%) prepared by solid state reaction at elevated temperature. 리튬이온전지의 스피넬형 양극활물질 $LiMn_2O_4$의 입자 크기 및 비표면적의 전기화학 특성상의 영향을 고찰하기 위하여 스피넬 물질을 공침법과 고상법에 의해 합성되었다. X-선 회절분석을 통하여 합성된 두 물질 모두 Fd3m space group을 갖는 스피넬 구조가 형성된 것을 확인하였다. 공침법을 사용하여 얻은 물질은 상대적으로 높은 충진 밀도와 균일한 입도 분포를 갖는 구형의 분말이었다. 그러나 고상법을 사용하여 얻은 활물질은 비교적 입자 크기가 작고 넓은 입도분포를 나타내었다. 측정된 두 물질의 비표면적(BET)은 각각 $0.8m^2g^{-1}$(공침법)과 $3.6m^2g^{-1}$(고상법)로 큰 차이를 보였다. 두 물질의 전기화학적 특성을 평가하기 위하여 코인타입(CR2032)전지를 제작하여 고온($55^{\circ}C$)에서 충 방전테스트를 하였다. 공침법으로 합성된 물질의 고온에서 방전용량 유지율은 50사이클 이후 고상법으로 합성된 물질의 68.3% 보다 14% 향상된 82.3%로 향상된 방전용량 유지율을 보였다.

백터기반의 개인캐릭터 생성 및 게임미디어 시스템 설계 및 구현

이기수,이동열,Lee, Ki-Soo,Lee, Dong-Lyeor 한국콘텐츠학회 2005 한국콘텐츠학회지 Vol.3 No.2

실리카 담지 메탈로센 촉매를 이용한 폴리스티렌의 분자량 분포조절

이기수,최경우,임진형,오창건,임선기 ( Ki Soo Lee,Kyung Woo Choi,Jin Heong Yim,Son Ki Ihm ) 한국화학공학회 1996 화학공학의이론과응용 Vol.2 No.2

외국의 허위자백 연구동향과 형사정책적 함의

이기수(Lee, Ki Soo) 한국형사법무정책연구원 2014 형사정책연구 Vol.99 No.-

하악 전돌증에 관한 방사선 두부계측학적 연구

이기수(Ki-Soo Lee) 대한치과교정학회 1979 대한치과교정학회지 Vol.9 No.1

This investigation was designed to compare the craniofacial and dental morphology of class III malocclusion with that of normal occlusin in children, and to determine the incidence of various class III craniofacial skeletal patterns. The material selected for this study consister in standard pateral cephalograms of eighty two Korean children, forty one boys and forty one girls, aged 10 through 12 years, having class III maloccluaion, and forty two Korean children, twenty boys and twenty two girls, with normal occlusion in the same age. Using the tracings of the standard lateral cephalograms, various angular and linear measurements were recorded, tabulated and statistically analyzed, and then normal range of those of normal occlusion. The followion characteristics of the craniofacial and dental morphology of class III malocclusion were observed. 1. The cranial base length of class III malocclusion was smaller than that of normal occlusion, and the small saddle angle was a characteristic figure of class III malocclucion. 2. Maxillary length of class III malocclusion was smaller than that of normal occlusion, and point A was retropositioned relative to cranial base but not PNS in class III malocclusion. Maxillary base inclination was not significantly different between the two, but occlusal plane to palatal plane was small in class III malocciusion. 3. The mandibular body length shown no difference between the two, but the mandibular body positioned anteriorly relative to cranial base in class III malocclusion. Ramus height, gonial angle, and mandibular effecctive length were large in class III malocclusion. Mandibular plane angle and joint angle had no difference between the two, and occlusal plane to mandibular plane angle was large in class III malocclusion. 4. Maxillary incisor inclination was not significantly different between class III malocclusion and normal occlusion, but mandibular incisors positioned and inclined lingually and consrquently interincisal angle was latge in class III malocclusion. 5. Class III malocclusion was dividid into six categories of craniofacial skeletal pattern. The most common class III pattern was found to be one in which the normal range of prognathism while the mandible was within this range was approximately one fifth of the class III sample.

上顎 側切齒가 遺失된 症例의 臨床的 考察과 治験一例

李起受(Ki-Soo Lee),張英一(Yong Il Chang) 대한치과의사협회 1980 대한치과의사협회지 Vol.18 No.8

頭蓋顔面骨의 成長變化에 關한 硏究

이기수(Ki-Soo Lee) 대한치과교정학회 1978 대한치과교정학회지 Vol.8 No.1

The growth changes in craniofacial depth and height from seven to eleven years of age have been studied in thirty two Korean children, consisted of seventeen boys and fifteen girls. The data was obtained from lateral cephalometric radiographs analyzed by the Coben’s coordinate system, and the main conclusions might be summarized as follows. 1. Among the craniofacial depth increments the lower facial depth dimension increased the most, mid-facial depth dimension increased less, and cranial depth dimension increased the least. 2. In spite of the increasing depth dimensions, the mid-facial depth proportion had a tendency to remain stable. 3. The degree of overbite increased markedly from seven to eleven years of age. 4. Increment in the total anterior facial height dimension was larger than that in the total posterior facial height, and the upper anterior facial height increased more than the lower anterior facial height. 5. The lower facial depth proportion increased markedly, and the convexity of the face was reduced significantly. 6. The posterior facial height tended to show small proportional changes. 7. The growth increments in criofacial complex were larger in the facial height than in the facial depth.

상악중절치에 만곡치근을 가진 환자의 교정치료에 대한 치험예

이기수(Ki Soo Lee),박영국(Young Guk Park) 대한치과의사협회 1988 대한치과의사협회지 Vol.26 No.12

鑛山 地域 學生의 身長및 體重에 關한 調査研究

李起受(Ki Soo Lee) 대한치과교정학회 1972 대한치과교정학회지 Vol.3 No.1

경찰관 법정증언의 실태와 개선방안

이기수 ( Ki Soo Lee ) 단국대학교 법학연구소 2012 법학논총 Vol.36 No.1

Police officers`` testimony in court is expected to increase drastically due to enforcement of trial-oriented court proceeding, expanded implementation of court proceedings with laymen`s participation, introduction of investigators`` testimony system, etc. Under such circumstances, status of court testimony by police officers could be identified through a questionnaire survey conducted with police officers in the national police agency, where several problems were exposed as well. First, police officers did not have sufficient experience in the court testimony, and task burdens by police were expected to increase with an increase in the court testimony. Also lack of systematic instruction on the court testimony was also revealed as a problem, while no unified measures were shown to be available on recollection of memories related to the incident for a testimony, As improvement measures to resolve these problems, First, specialized instructions in relation to the court testimony were suggested to be implemented. It was emphasized that broad and systematic instructions should be directed to basic matters such as preparation for the court testimony, anticipated questions, required testimonial techniques, methods of memory recollection, legal knowledge such as perjury, etc. For instruction method, it was pointed out not be limited to one-time training but needs to be on a constant and regular basis taking into account such things as personnel transfer, recruitment of new officers, changes in regulations, etc. Secondly, needs for systematically managing police officers`` court testimony were discussed, with a statement that designation of a devoted department, provision of legal services through operation of specialized counselors, etc. were needed. Thirdly, it was suggested that police officers`` task loads were to be reduced through prior task discussions with the court and the prosecutors`` office having direct relations with police officers`` court testimony and that matters required for smooth testimony should be adjusted.