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.

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.

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.

정책갈등의 요인과 관리방안

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

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.

주방환기 시스템의 공기 급기구의 위치에 따른 성능평가

임경빈,송시영,이찬호 한밭대학교 생산기반기술연구소 2003 생산기반기술연구소 논문집 Vol.3 No.1

The purpose of this study is to investigate the performance evaluation of indoor diffusion rate of surplus heat generated from gas range and concentration distribution of combustion gas by position change of air- diffuser and range-hood with separating plate. A numerical analysis is performed with four cases of this ventilation system for kitchen. The results showed that thermal and flow distribution can be more effective, when air supply diffuser is located at middle position. Also, Comparisons of Indoor Air Quality(IAQ) are made between using separating plate and not using, IAQ was improved in case of using separating plate and also, kitchen exhaust hood concentration distribution was improved about 30%

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.

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.

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.