3D flexible Si based-composite (Si@Si₃N₄)/CNF electrode with enhanced cyclability and high rate capability for lithium-ion batteries

Kim, Si-Jin,Kim, Min-Cheol,Han, Sang-Beom,Lee, Gyu-Ho,Choe, Hui-Seon,Kwak, Da-Hee,Choi, Sun-Yong,Son, Byung-Goo,Shin, Myoung-Sun,Park, Kyung-Won Elsevier 2016 Nano energy Vol.27 No.-

<P><B>Abstract</B></P> <P>Despite extremely high capacity of Si-based anodes in lithium-ion batteries (LIB), Si-based materials have shown a structural collapse caused by a volumetric expansion/contraction during the cycling process. The conventional electrode structure, which consists of active materials, a current collector, a conducting agent, and a binder, actually showed a low loading of active material due to the other heavy components. In this study, we prepared a 3D flexible Si-composite electrode consisting of core (Si)-shell (Si<SUB>3</SUB>N<SUB>4</SUB>) NPs (Si@Si<SUB>3</SUB>N<SUB>4</SUB>) and carbon nanofibers (denoted as Si-composite/CNF). The Si-composite/CNF was directly utilized as an anode in the absence of the other components was electrochemically evaluated using a coin-type cell. The Si-composite/CNF showed a high capacity of 665mAhg<SUP>−1</SUP> at a fairly high current density of 10Ag<SUP>−1</SUP> and an extremely low capacity loss for 2000 cycles.</P> <P><B>Highlights</B></P> <P> <UL> <LI> We prepared Si-composite/CNF exhibits a 3D flexible Si-composite electrode. </LI> <LI> The electrode consists of core (Si)-shell (Si<SUB>3</SUB>N<SUB>4</SUB>) NPs (Si@Si<SUB>3</SUB>N<SUB>4</SUB>) and carbon nanofibers. </LI> <LI> The Si-composite/CNF was directly utilized as an anode. </LI> <LI> Si-composite /CNF exhibited high specific capacity and improved high rate cycling performance. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

폐암과 동반되어 나타난 기관기관지병증 골연골형성증 1예

이영진,전현수,박시형,김모세,김현주,이승헌,이영민,이현욱,이현경 仁濟大學校 白病院 2010 仁濟醫學 Vol.31 No.-

Tracheobronchopathia osteochondroplastica (TPO) is a rare benign disease of unknown etiology characterized by multiple cartilaginous or bony submucosal nodules, which project into the tracheobronchial lumen. Although some disorders were reported combined with TPO, these seemed to be considered casual. We report a case of TPO that combined with adenocarcinoma of lung. She was 50-year-old non smoking woman presented with chronic cough with right chest pain. Lung mass on right lower lobe was found on chest x-ray, so lung cancer was suspected. Multiple scattered whitish small elevations from trachea to bronchial trees were found on bronchoscopic exam. We mistook these lesions for metastases from lung cancer and biopsies of these lesions were done. Transbronchial biopsy for right lower lobe mass lesion was also done. But biopsies from trachea and bronchus revealed TPO rather than lung cancer. Transbronchial lung biopsy of right lower lobe mass was diagnosed adenocarcinoma of lung. So TPO combined with adenocarcinoma of lung was diagnosed.

사회공포증 환자의 성격요인과 방어기제에 대한 연구

이시형,백상빈,노경선,오강섭,신영철 大韓神經精神醫學會 1999 신경정신의학 Vol.38 No.6

연구목적: 사회공포 환자의 성격요인과 방어기제의 특징을 알아보고, 비가해형 및 가해형에 따라 유의미한 차이가 있는지 알아보고자 본 연구를 시행하였다. 방 법: 강북삼성병원 외래치료 환자중 DSM-Ⅳ에 근거하여 사회공포로 진단된 환자 28명을 대상으로 성격요인검사(Sixteen Personality Factor Questionnaire 한국판) 및 이화방어기제검사를 시행하였고 통계처리는 각 검사에 대한 빈도분석과 비가해형과 가해형에 대한 Independent-Sample t-test를 시행하였다. 결 과: 사회공포 환자에서 성격요인(평균점수) 중 shyness/boldness 요인이 정상보다 낮은 소견을 보였으며 방어기제에서는 유우머 항목이 정상보다 낮은 소견을 보였다. 성격요인과 방어기제 모두에서 비가해형과 가해형간에 유의미한 차이는 보이지 않았다. 결 론: 성격요인의 결과상 사회공포 환자들은 감정 표현을 억제하며 비사교적이다. 또한 자기주장을 못하여 타인에게 순종적, 동조적이며 정서적 불안정감이 심하다. 이러한 성격요인들은 모두 자율신경계의 약화, 불안의 증가, 공포증의 유발가능성의 증가등으로 사회공포와 관련되어 있다. 또한 방어기제의 결과상 사회공포 환자들은 유우머가 부족하고 지나치게 긴장, 경직되어 있어 사회공포 증세를 유발하기 쉬운 것으로 판단되었다. 사회공포의 두 유형인 비가해형과 가해형간에는 성격요인, 방어기제 모두에서 유의미한 차이가 없는 것으로 나타났다. Objectives: The purpose of this study was to evaluate the characteristics of personality factor and defense mechanism and to compare the difference between non-offensive and offensive types of social phobia patients. Methods: Study subjects consisted of 28 social phobia patients diagnosed with the criteria of DSM-Ⅳ. Data were collected through Sixteen Personality Factor Questionnaire and Ehwa Diagnostic Test of Defense Mechanism. We employed was the independent sample t-test for the analysis. Result: Among the personality factor, the shyness/boldness factor scored lower than normal in social phobia patients. Humor defense scored lower than normal among defense mechanisms. There was no significant correlation between non-offensive and offensive types of social phobia in personality factors and defense mechanisms. Conclusions: Social phobia patients were shier and less frequently use humor defense than the ordinary people. There was no significant correlation between non-offensive and offensive types of social phobia patients in personality factors and defense mechanisms.

저농도 노말헥산의 만성폭로가 말초신경계에 미치는 영향

이수진,송재철,장은철,이경영,심상효,박시복,박영재,김현주 大韓産業醫學會 1999 대한직업환경의학회지 Vol.11 No.3

Objectives: The effect of chronic exposure to low levels of n-hexane on peripheral nervous system and the relationship between duration of employment and impairment of peripheral nervous system was studied. Methods : In 21 workers at two shoe-maker factories and 21 unexposed controls, measurement of exposure of solvents, symptom Questionnaire, physical examination and electrophysiological study were conducted. Results : Mean ages of study subjects in the exposed and the unexposed were 39.9 and 40.1 years old. Mean durations of employment were 15.1 and 10.0 years, respectively. Mean concentrations of urinary 2.5-HD were 2.23 mg/g creatinine, 0.23 mg/g creatinine, respectively. Mean concentration of solvents in air were 21.1 ppm of n-hexane, 72.2 ppm of toluene and 0.5 ppm of MEK. There were no differences in the prevalence of subjective symptoms and abnormal neurological signs between the exposed and the unexposed. But vibration extinction time(VAT) of the exposed (8.8 second) was shorter than that of the unexposed (11.9 second) (p<0.05). Mean values of electrophysiological studies(EPS) of the two groups were within normal limit. However, mean conduction velocity of median motor nerve and median F wave(MMNCV and MFCV), mean amplitude of median sensory action potential(MSAP) were decreased in the exposed (p<0.05). Moreover, the rate of abnormal finding more than one in sensory nerves was increased in the exposed than those in the unexposed(p<0.05). Correlation coefficients between duration of employment and mean conduction velocity of median sensory nerve (MSNCV) and between duration of employment and MFCV were -0.57, -0.43, respectively (p<0.05). Conclusions : These results showed that chronic (mean 15 years) low level(mean 23 ppm) exposure to n-hexane cause subclinical impairment of peripheral nervous system. These results also suggest that the longer duration of employment, the shorter values of EPS and VAT.

정책갈등의 요인과 관리방안

이시경 啓明大學校 社會科學硏究所 2003 한국사회과학연구 Vol.22 No.1

渭川工團 葛藤에 대한 利害關係集團의 認識과 對應行態

이시경 동국대학교 지역정책연구소 2000 地域發展硏究 Vol.6 No.1

This study tries to find the mutual perception of conflict behavior in the designation of Wi-Chon National Industrial Complex. In the study of Wi-chon policy conflict case, it is not yet investigated to the behavior and mutual perception of policy interest groups among regions. We used questionnaire and cross analysis to find the mutual behavior of policy interest groups. According to this study, there are much difference in mutual perception among policy interest groups, and also citizens has no credit with Wi-chon national policy. Therefore, it is necessary to practice the negotiation among policy interest groups about critical points.

금속-도재 수복물에서 비귀금속 합금의 재사용에 따른 결합강도에 관한 연구

임시덕,이은경,장기환 한국위생과학회 2001 한국위생과학회지 Vol.7 No.2

치과용 비귀금속 합금 중 Verabond와 RecilliumⅢ,Ⅴ를 사용하여, 새 금속만 사용한 group(Ver-1, Rex3-1, Rex5-1)과 재사용한 group(Ver-2, Rex3-2, Rex5-2)의 경도측정을 한 결과 새금속만을 사용한 group에서는 Ver-1이 경도측정치가 가장 높았으며, 재사용한 group에서는 Rex5-2가 가장 높은 경도 측정치를 나타내었고 Rex3에서는 Rex3-1과 Rex3-2간의 경도 차이는 없었다. Verabond와 RexolloumⅢ,Ⅴ를 사용한 것과, 새 금속만을 사용하여 Vita Omega Porcelain을 올려서 소성하고, 금속과 도재간의 결합강도를 측정 한 것과, 한번 주조된 비귀금속 합금에 50%의 새로운 합금을 사용하여 Vita Omega Porcelain을 올려서 소성하고, 금속과 도재간의 결합강도를 측정한 결과 재 사용한 금속 중 Rex5-1이 금속과 도재간의 결합강도가 가장 좋은 것으로 나타났고, 주조된 합금에 새 금속 50%를 섞은 group에서는 Rex5-2가 결함강도가 가장 낮은 것으로 나타났다. 그러나 Ver-1과 Ver-2는 금속과 도재간의 결합강도는 큰 차이점이 없는 것으로 보인다. The hardness of non-precious dental alloy was measured using Verabond and Rexillium Ⅲ,Ⅴ, The dental alloy was group into a new alloy group (Ver-1, Rex5-1) and used alloy (Ver-2, Rex5-2). As a result, Ver-1 showed the highest hardness value in a new alloy group. and Rex5-2 showed the highest hardness value in a used alloy group. However, Rex3-1 and Rex3-2 did not show any difference in hardness. The bonding strength between alloys used Verabond and Rexillium Ⅲ,Ⅴ was tested; The bonding strength between porcelain and a new alloy, which was firing after build up weth Vita Omega porcelain; was tested; Also, the bonding strength between porcelain and metal, which was casted and firing after build up with vita Omega pocelain was tested. I this case, the casted alloy was mixed with a new alloy by hay in weight. As a result, Rex5-1 yielded the highest strength among the used alloy group. Rex5-2 was the lowest in bonding strength among the alloy mixed with casted alloy and a new alloy by hay in weight. On the other hand, Ver-1 and Ver-2 did not show apparent difference in bounding strength.

初等學校 校庭內 生態園 造成技法 : With a Special Reference to Hu-am Elementary School in Yong-san gu, Seoul 서울 龍山區 厚岩 初等學校 事例를 중심으로

진시현,심우경,이광우 韓國植物ㆍ人間ㆍ環境學會 2000 인간식물환경학회지 Vol.3 No.1

이 논문의 연구목적은 초등학교내에 생태원을 조성함으로써 아이들에게 자연과의 접촉기회를 제공하고자 실시한 바, 그 결과는 다음과 같다. 1. 초등학교 교과서에 나타나는 모든 동, 식물의 종류 초등학교의 교과서 분석 경과 274종의 식물종과 227종의 동물종이 나타났으며, 가장 높은 빈도수를 나타낸 곤충은 나비 78회, 잠자리 64회, 개미 51회, 벌 41회, 그리고 매미가 31회의 순으로 나타났다. 이는 교과서별 학년별로 빈도수를 조사한 결과와도 비슷한 양상을 나타낸 것이다. 초등학교 교과서 중 자연과 과목의 교육내용을 살펴본 결과, 1∼2학년 과정에서는 학교내의 뜰과 화단의 4계절 변화를 관찰하고 3∼6학년 과정에서는 생태계 전반에 걸친 세부적인 내용을 공부하도록 교육내용이 설정되었음을 알 수 있었다. 2. 용산구에 있는 15개의 초등학교의 옥외환경 조사 용산구에는 15개 학교가 있고, 그들의 옥외환경의 형태는 교재원과 생산원의 두 가지 종류로 나타났다. 대부분의 학교가 이 두 가지 형태로 나타났으나 남정, 보광, 원효로, 한강 초등학교는 생태원의 시설중 소동물 사육장 시설이 없었고, 교재원의 시설도 빈약하였다. 사례지역인 후암 초등학교는 도시의 중심부에 위치해 있는 다른 초등학교와는 달리 풍부한 생물상을 가지고 있는 남산에 인접하고 있기 때문에 생태원으로서의 기능성이 있는 것으로 보여진다. 3. 사례연구와 생태원 조성계획 생태원의 조성방법으로서 우선, 사례지인 후암 초등학교 부지의 현황조사를 하였고, 두 번째로 4가지 곤충(나비, 잠자리, 벌, 매미)들을 유치하기 위한 식물들을 선별하기 위해 이들이 식이식물로 조사된 식물들 중에서 교과서에 나오고 사례지역에 적합하며 내공해성을 가지며, 자생종이 식물들을 선별한 결과, 나비, 잠자리, 새를 유치하기 위한 식이식물로 각각 44, 17, 16종이 선별되었다. 또한 이 학교의 건물이 도로와 맞닿는 점을 감안하여 건물옥상에 생물서식지를 조성함으로서 남산으로부터의 풍부한 생물종의 유입을 유도하고, 더 나아가 학교 내에 조성되는 생태원으로 자연스럽게 유도하고자 하였다. 따라서 옥상 위의 생물서식공간은 수변공간계획과 식재계획을 통하여 곤충류와 조류뿐만 아니라 다양한 생물종이 서식되도록 하였고, 이를 통해 초등학교 학생들은 자연과의 친밀한 접촉기회를 가지게 될 것이다. The purpose of this study was to offer the opportunity of contact with the nature to urban children by the creation of the biotope in the elementary school ground. The results for this study were as follow: 1. The kinds of animals and plants the elementary school textbooks were 275 species and 227 animals. The frequencies of insect species in the elementary school textbook were the butterfly(75), dragonfly(64), ant(51), bee(41), and cicada(31) in order. These results were analogous to the numbers in each textbook and grade. In the 'Nature' textbook of the elementary school, there were educational contents to observe the ground and garden in 1, 2 grade courses and to study the detail of ecosystem in 3-6 grade course. 2. Inventory of the out-door environments of 15 elementary schools in Young-san Gu, Seoul. The number of total elementary school in Young-san Gu were fifteen, which had two garden types appeared as nature study and experimental farm. Two types of gardens were appeared mostly in all the elementary school but Nam-jung, Bu-kwang, Wonhyo-ro, Sin-swang, and Han-gang elementary school didn't have the experimental farms and also have the poor facilities of the nature study gardens. Huam elementary school had the possibility of the biotope creation because it was connected to Namsan park which posseses the abundant biota in contrast to the others in the center of the city. 3. Case study and biotope planning. To create the biotope, the site analysis was carred out and then plant species for inducing 4 kinds of insect (butterfly, dragonfly, bee, and cicada) were selected under the criteria as pollution-resistant, the school tree and flower, tolerance, and original habitat. Consequently, the numbers of plants for inducing butterflies, dragonflies and birds were 44, 17, 16 species separately. Also, it was planned to the induce abundant biota to building's roof as stepping stone from Namsan. These two biotopes were planned to be a habitat of various biota in addition of the water pond and the planting plan. Through the biotope created by this plan, the students of the elementary school will have more opportunity of contact with the nature.

흰쥐에서 심정지후 Pentoxifylline이 뇌의 허혈-재관류 손상에 미치는 효과

정시경,김영민,오동렬,최경호,박승현,이운정,박규남,유은영,이원재,김세경 大韓應急醫學會 1999 대한응급의학회지 Vol.10 No.2

Background: Two major events occurring in the cerebral hemodynamics after successful resuscitation from cardiac arrest are reactive hyperemia and postischemic hypoperfusion. In this study, we examined the effect of Pentoxifylline(PTX) on the rat brain following cardiac arrest. Methods: Fourteen rats were anesthetized and artificially ventilated. Cardiac arrest was produced by chest compression and clamping of tracheal tube for 3 minutes in ketamine anesthetized rats. Circulation was restored by standard cardiopulmonary resuscitation methods. In 7 rats, PTX 10mg/kg was infused at 10min after cardiac arrest(PTX group). In the other 7 rats, same amount of normal saline was infused(control group). Results: In both groups, hemodynamic variables, neurologic deficit(ND) score and histopathologic findings of hippocampal CA1 neurons were observed. Hemodynamic variables and ND score were not significantly different between two groups. Delayed ischemic neurons of hippocampal CA1 were decreased in PTX group(2.2±2.4%) compared with control group(9.1±1.2%). Conclusions: We conclude that PTX prevented development of delayed ischemic neurons in hippocampal CA1 after cardiac arrest. PTX may be useful in emergency situations following cardiac arrest.

화주 직접운항 선대의 운영 최적화 분석

김시화,이경근 한국경영과학회 1998 韓國經營科學會誌 Vol.23 No.4

The Industrial operation is one of the three basic modes of shipping operation with Liner and Tramp operations. Industrial operators usually control vessels of their own or on a time charter to minimize the cost of shipping their cargoes. Such operations abound in shipping of bulk commodities, such as oil, chemicals and ores. This work is concerned with an operational optimization analysis of the fleet owned by a major oil company. a typical Industrial operator. The operational optimization problem of the fleet of a major oil company is divided into two phase problem. The front end corresponds to the optimization problem of the transportation of crude oil. product mix. and the optimization problem of the fleet to meet the seaborne transportation demand derived from the front end. A case study reflecting the practices of an international major oil company is demonstrated to make clear the underlving ideas.