흰쥐에서 급성 Adriamycin 유발 심근증과 세포 자멸과의 관계: 15 MHz 고주파 탐촉자를 이용한 연구

최윤석,박철수,조은주,정해억,전희경,강진형,이정화,윤호중,채장성,김재형,최규보,홍순조 한국심초음파학회 2002 Journal of Cardiovascular Imaging (J Cardiovasc Im Vol.10 No.2

Unveiling the behavior of molybdenum disulfide with lithium through comparison of bulk and nano-sized MoS₂

최윤석,이규성,김지만 한국공업화학회 2018 한국공업화학회 연구논문 초록집 Vol.2018 No.0

MoS₂ has superior electrochemical properties suit for lithium ion battery, such as high theoretical capacity (670 mAh/g), low volume expansion during cycle (~103%) and the week vdw forces between layers, which offers facile route for Li⁺. The lithium storage mechanism of MoS₂ is widely known as an irreversible intercalation reaction in the first cycle and reversible conversion reactions (MoS₂ + 4Li⁺ + 4e^- ↔ Mo + 2Li₂S). However, some recent studies contradict above mentioned pathway and suggest different reversible reaction path (Li₂S ↔ 2Li⁺ +S^2-), similar to the Li-S battery reaction. In order to clarify the reaction process, we synthesized ordered mesoporous MoS₂ as a model structure to ascertain the complete reaction by obtaining the maximum reversible capacity from this material. We also utilized synchrotron radiation based characterization techniques to directly observe local and bulk structural changes in well-synthesized mesoporous MoS₂ during the electrochemical cycling.

이중보온 온수배관의 부식피로균열 특성에 관한 연구

최윤석,김정구,정민경,이훈 대한금속재료학회 2004 대한금속·재료학회지 Vol.42 No.2

The corrosion fatigue properties of thermally insulated pipeline were investigated in synthetic groundwater by electrochemical test, corrosion fatigue test and SEM analysis. Since the potential difference between the weldment and the base metal was small, the pipeline steel was not susceptible to galvanic corrosion. No fatigue limit was apparent for corrosion fatigue testing with remarkable reduction of fatigue lifetime. The effects of insulation and stress on the corrosion fatigue resistance of pipeline steel were studied through linear polarization resistance (LPR) and electrochemical impedance spectroscopy (EIS) during corrosion fatigue testing. The result of LPR measurement indicated that the corrosion rate was determined not by the water content of PUR foam but by the magnitude of applied stress. The better corrosion fatigue property of the insulated steel was attributable to the formation of a protective rust layer under the insulation, which reduced the acceleration of corrosion process and the propagation of fatigue crack. This was confirmed by the results of EIS measurements and SEM observation.

Application of electrochemical deposition to high-temperature fuel cell electrodes

최윤석,정우철 한국공업화학회 2016 한국공업화학회 연구논문 초록집 Vol.2016 No.1

The state-of-the-art anodes for solid oxide fuel cells (SOFCs), composed of Ni and YSZ (yttria-stabilized zirconia), suffer significantly from Ni-catalyzed carbon deposition and the ensuing degradation of the anode performance. Here, we address these issues through the application of a simple, scalable, cost-effective ceramic coating method known as cathodic electrochemical deposition (CELD). We show that just 1 minute of CELD treatment creates an oxide coating that significantly enhances activity for hydrogen (or methane) electrooxidation relative to the uncoated substrate. We further show that the CELD coated anode has exceptional resistance to carbon deposition, suggesting it as a feasible solution for the direct use of hydrocarbon fuels in SOFCs.

Enhanced Lithium Storage Performances of Mesoporous MoS₂

최윤석,최우성,김희준,윤원섭,김지만 한국공업화학회 2016 한국공업화학회 연구논문 초록집 Vol.2016 No.1

Conventional LiBs based on intercalation electrode cannot meet the increasing demand for high-power density due to intrinsically low capacities. Meanwhile, the study of 2D-materials has been a growing interest since the first successful fabrication of a single layered graphene. Among 2D-materials, MoS₂ has attracted great attention as an electrode material for its unique properties. Not only its cheapness and non-toxicity but the weak vdW forces between layers enables facile intercalation/ exfoliation of Li⁺ and full conversion provides 4e^- transfer reaction results in high theoretical capacity (670 mAh/g). However, low rate capability and poor cycling are still considered as drawbacks. Herein, mesoporous MoS₂ are synthesized with KIT-6 template and tested with respect to its applicability in LiBs. As expected, the material showed ascending high capacity upon cycle, excellent cycle stability, and good rate capability, suggesting its potential application in high-energy batteries.

Anticorrosive properties of polyaniline/graphene nanohybrids

최윤석,윤현석 한국고분자학회 2019 한국고분자학회 학술대회 연구논문 초록집 Vol.44 No.1

Ordered mesoporous transition metal oxides: energy storage for lithium-sulfur cathode

최윤석,오세민,김지만 한국공업화학회 2016 한국공업화학회 연구논문 초록집 Vol.2016 No.0

Lithium-sulfur batteries are upcoming electrochemical devices due to its advantages such as high specific capacity and energy density. Despite its superiority, practical use of Li-S battery is impeded because of obstacles; insulating character of sulfur and dissolution of polysulfide Intermediates. Majority of studies have focused on porous carbon materials not only to impart sulfur conductivity but also to capture polysulfide by physisorption. In this work, we present new possibility of porous metal oxides (MOx) for Li-S battery cathode as host material. We expect that our cathode can effectively trap polysulfide by chemisorption and retard the dissolution of it. Consequently, it results in better cycling performance. Ordered mesoporous MOx (TiO2, MnO, NiO) were synthesized by a nano-replication method via ordered mesoporous silica (KIT-6). The materials were characterized by X-ray diffraction, N2 adsorption/desorption, scanning electron microscopy.

Elucidation of inherent lithium storage mechanism on MoS₂ via Synchrotron-based X-ray analysis

최윤석,김지만 한국공업화학회 2020 한국공업화학회 연구논문 초록집 Vol.2020 No.-

Numerous studies have been conducted on a MoS₂ material owing to its high capacity and good rate capability as a promising substitute for commercial graphite materials in lithium-ion batteries. However, the mechanism of the reversible lithium ion storage in MoS₂ remain still unclear. Herein, we carried out an in-depth study about the lithium storage behavior of MoS₂. The conversion reaction was verified by monitoring the reversible formation of MoS₂ phase through the X-ray absorption and X-ray photoelectron spectroscopies. Moreover, reversible Li-S like reactions were demonstrated by investigating the sulfur redox reaction through the voltage profile comparison and X-ray photoelectron spectroscopy deconvolution. The results of systematic approach to the reaction mechanism present clear evidence that both the Li-S like reaction and the conversion reaction contribute to the initial obtained capacities.

계약해제와 귀책사유 - 독일민법상의 채무불이행에 기한 법정해제권의 역사적 발전과의 비교 -

최윤석 한국민사법학회 2016 民事法學 Vol.74 No.-

Das koreanische Zivilgesetzbuch (KZGB) regelt das Rücktrittsrecht des Gläubigers wegen Verzugs der Leistung in § 544 KZGB („Leistet die eine Partei die ihr obliegende Verbindlichkeit nicht, mahnt die andere Partei diese und setzt eine angemessene Frist zur Leistung, so kann die andere Partei von dem Vertrag zurücktreten, wenn die eine Partei innerhalb dieser Frist nicht leistet. Der Mahnung bedarf es nicht, wenn der Schuldner seinen Willen bereits erklärt hat, nicht zu leisten.“), wegen Fixgeschäftes in § 545 KZGB („Erfolgt eine Leistung nicht zu einer bestimmten Zeit oder innerhalb einer bestimmten Frist nach dem Wesen des Vertrages oder den Willenserklärungen der Parteien und kann der Zweck des Vertrages dadurch nicht erreicht werden, so ist die andere Partei berechtigt, ohne Mahnung gemäß § 544 von dem Vertrag zurückzutreten, wenn die eine Partei zu dieser Zeit oder innerhalb dieser Frist nicht leistet.“) und wegen der vom Schuldner zu vertretenden Unmöglichkeit der Leistung in § 546 KZGB („Wird eine Leistung infolge eines Umstandes, den der Schuldner zu vertreten hat, unmöglich, ist der Schuldner berechtigt, von dem Vertrag zurückzutreten.“). Die koreanische Rechtsprechung erwähnt das Vertretenmüssen des Schuldners nur im Fall der Unmöglichkeit und schweigt in allen übrigen Fällen. Dagegen geht die herrschende Lehre davon aus, dass das Vertretenmüssen des Schuldners nicht nur für den Fall der Unmöglichkeit, sondern auch im Fall des Verzugs sowie des relativen Fixgeschäfts erforderlich sei. Um das Verhältnis zwischen dem Rücktrittsrecht in §§ 544-546 KZGB und dem Vertretenmüssen, das sich im koreanischen Recht auf das Verschulden bezieht, zutreffend zu erfassen, ist die Entstehungsgeschichte des deutschen Rücktrittsrechts, insbesondere vor der Modernisierung des Schuldrechts im Jahr 2002 zu untersuchen, da das KZGB unter starkem Einfluss des deutschen BGB kodifiziert wurde. Diese Untersuchung führt zu dem Ergebnis, dass die Väter des BGB lediglich für die Unterscheidung des Zufalls von dem der vom Schuldner zu vertretenden Unmöglichkeit den Begriff „zu vertreten“ in § 325 BGB a. F. aufgenommen haben. Die Grundlage des Rücktrittsrechts entnahmen sie der vom Vertretenmüssen des Schuldners unabhängigen „actio redhibitoria (Wandlungsklage)“, die im römischen Recht dem Gläubiger im Bereich der Gewährleistung beim Kaufvertrag eingeräumt wurde. Unter Berücksichtigung der Umstände, dass die §§ 544, 545 und 546 KZGB bezüglich des gesetzlichen Rücktrittsrechts mit den §§ 325, 361 und 326 BGB a. F. kaum Unterschiede aufweisen, sind die Ergebnisse der Untersuchung des deutschen Gesetzgebungsverfahrens auf die §§ 544-546 KZGB übertragbar. Dementsprechend ist festzustellen, dass die Wandlungsklage die Grundlage für das Rücktrittsrecht im KZGB bildet. Aus diesen Gründen bedarf es keiner Überarbeitung und Änderung der §§ 544-546 KZGB im Hinblick darauf, ein vom Vertretenmüssen des Schuldners unabhängiges Rücktrittsrecht zu schaffen. Ein solches Rücktrittsrecht besteht bereits nach geltender Rechtslage, was die herrschende Literatur verkennt.

공부하는 학생선수 정책 이행과정에 대한 현실탐구

최윤석,박재우 한국체육학회 2022 한국체육학회지 Vol.61 No.3

This article explores the reality of the studying student athletes policy including policy acceptance, policy awareness and practical difficulties in terms of student athletes as policy beneficiary. The paper draws on evidence from data from a series of semi-structured interviews and documents including media publications, official government documents and research reports. According to our analysis, this article identifies three key features of the policy implementation that have influenced student-athletes, as follows: (i) The perception of the type of application of the minimum academic achievement standards was found to be 'raising positive perception of study' and 'different priorities of policy makers and beneficiaries', and the perception of learning activity support type was confirmed to be 'effective for motivation for study' and 'meaningless learning support’.; (ii) The types of acceptance for the type of application of the minimum academic achievement standards were 'change from player to student' and 'the purpose of policy lost along with coercion', and 'new experiences and opportunities through learning activities' and 'degradation and abuse of policy intent',; (iii) Realistic difficulties which they experienced in the process of implementing the minimum academic achievement standards were 'easy difficulty level of the standard' and 'difficulty in creating a learning atmosphere', and ‘their own privilege' and 'difference between policy and field' were identified.