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Superior Cluneal Nerve Entrapment as Uncommon Cause of Buttock Pain
Jeeyoung Jun,Jinyoung Oh,Dahee Park 대한통증연구학회 2021 International Journal of Pain Vol.12 No.1
The superior cluneal nerve is a pure sensory cutaneous nerve and dominates sensation in the low back and buttock area. Entrapment of superior cluneal nerve around the iliac crest, superior cluneal neuropathy, is one of the etiology of low back pain or buttock pain, but diagnosis and treatment are still challenging. Here, we report a case that the buttock pain from cluneal nerve entrapment was diagnosed and treated by percutaneous interventions. Our patient, in this case, complained of chronic buttock pain that lasted for 6 months, and there was no response to the epidural block, medial branch block, and sacroiliac joint block, but the pain was relieved through the superior cluneal nerve block, and it was diagnosed as superior cluneal nerve entrapment neuropathy. The pain could be treated through nerve block and pulsed radiofrequency therapy. Buttock pain can be induced in many diseases, and accurate diagnosis cannot be made only by imaging studies and physical examination. Two or more diseases can simultaneously cause similar symptoms. Although superior cluneal nerve entrapment causes severe buttock pain, among several causes, it is difficult to diagnose superior cluneal nerve entrapment as the cause first. It is suggested that superior cluneal entrapment neuropathy could be considered as one of the causes in patients with buttock pain.
Jun, Areum,Shin, Jeeyoung,Kim, Guntae The Royal Society of Chemistry 2013 Physical chemistry chemical physics Vol.15 No.45
<P>Cobalt-containing cathodes often encounter problems such as high thermal expansion coefficients (TEC) and poor stability, making them unsuitable for practical use as cathode materials for intermediate-temperature solid oxide fuel cells (IT-SOFCs). This study focuses on the effects of Cu doping in the Co site of SmBa<SUB>0.5</SUB>Sr<SUB>0.5</SUB>Co<SUB>2</SUB>O<SUB>5+<I>δ</I></SUB> in terms of structural characteristics, electrical properties, electrochemical performance, redox properties, and performance stability as an IT-SOFC cathode material. The TEC value of a SmBa<SUB>0.5</SUB>Sr<SUB>0.5</SUB>Co<SUB>1.5</SUB>Cu<SUB>0.5</SUB>O<SUB>5+<I>δ</I></SUB> (SBSCCu50) sample is 12.8 × 10<SUP>−6</SUP> K<SUP>−1</SUP>, which is lower than that (13.7 × 10<SUP>−6</SUP> K<SUP>−1</SUP>) of a SmBa<SUB>0.5</SUB>Sr<SUB>0.5</SUB>Co<SUB>2</SUB>O<SUB>5+<I>δ</I></SUB> (SBSCO) sample at 700 °C. SBSCCu50 showed higher redox stability at lower <I>p</I>(O<SUB>2</SUB>) and a more stable cell power output while retaining desirable electrochemical performance, as compared with SBSCO. SBSCCu50 displayed reduced TEC values and enhanced redox and performance stability, as well as satisfactory electrical properties and electrochemical performance under typical fuel cell operating conditions. The results indicate that SBSCCu50 is a promising material as a cathode for IT-SOFCs.</P> <P>Graphic Abstract</P><P>Cu substitution in the Co site of SmBa<SUB>0.5</SUB>Sr<SUB>0.5</SUB>Co<SUB>2</SUB>O<SUB>5+<I>δ</I></SUB> provides a more stable cell power output, as compared with SmBa<SUB>0.5</SUB>Sr<SUB>0.5</SUB>Co<SUB>2</SUB>O<SUB>5+<I>δ</I></SUB>. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c3cp53883d'> </P>
Hybrid-solid oxide electrolysis cell: A new strategy for efficient hydrogen production
Kim, Junyoung,Jun, Areum,Gwon, Ohhun,Yoo, Seonyoung,Liu, Meilin,Shin, Jeeyoung,Lim, Tak-Hyoung,Kim, Guntae unknown 2018 Nano energy Vol.44 No.-
<P><B>Abstract</B></P> <P>Water electrolysis based on a solid oxide electrolysis cell (SOEC) has potential to be cost-effective, environmentally friendly, and highly efficient for hydrogen production. There are two types of SOECs, depending on electrolyte materials: oxygen ion conducting SOECs (oxygen-SOECs) and proton conducting SOECs (proton-SOECs). Here we report our new findings in exploring a SOEC based on a mixed-ion conductor that can transport both oxygen ion and proton at the same time, which is denoted as “Hybrid-SOEC”. When BaZr<SUB>0.1</SUB>Ce<SUB>0.7</SUB>Y<SUB>0.1</SUB>Yb<SUB>0.1</SUB>O<SUB>3-<I>δ</I> </SUB> was used as an electrolyte, the Hybrid SOEC shows the highest efficiency, demonstrating a current density of 3.16Acm<SUP>−2</SUP> at 1.3V and 750°C in 10% humidified hydrogen at hydrogen electrode and 10% humidified air at air electrode. Moreover, the Hybrid SOEC exhibits no observable degradation in performance for more than 60h of continuous operation, implying a robust system for hydrogen production.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The new concept of “Hybrid-SOEC“ based on mixed ionic conducting electrolyte is proposed. </LI> <LI> The Hybrid-SOEC shows excellent performance compared with other water-electrolysis systems. </LI> <LI> Current density of 3.16Acm<SUP>−2</SUP> at 1.3V (@750°C) is achieved based on the Hybrid-SOEC operation. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
Lim, Chaehyun,Jun, Areum,Jo, Hongil,Ok, Kang Min,Shin, Jeeyoung,Ju, Young-Wan,Kim, Guntae The Royal Society of Chemistry 2016 Journal of Materials Chemistry A Vol.4 No.17
<▼1><▼1><P>We investigated the phase transition and its correlated electrical and electro-chemical properties of a novel double perovskite series, PrBa1−xCaxCo2O5+δ.</P></▼1><▼2><P>Layered perovskite oxides with the formula LnBaCo2O5+δ (Ln = Pr, Nd, Sm and Gd) have received attention as promising cathode materials for solid oxide fuel cells (SOFCs) because of their high oxygen diffusion and surface exchange coefficients. Recently, many researchers have reported that substituting barium with strontium or calcium can increase the structural stability, electrical conductivity, and catalytic activity of LnBaCo2O5+δ. In this study, we investigated the effect of Ca doping on the structural, electrical, and electrochemical properties of PrBa1−xCaxCo2O5+δ (<I>x</I> = 0, 0.1, 0.2, 0.3 and 0.4). Increasing the amount of Ca dopant changed the structure of PrBa1−xCaxCo2O5+δ from a layered perovskite to a simple perovskite. At <I>x</I> = 0.3, co-existence of the simple and the layered perovskite structure is observed. Electrical conductivity and electro-chemical performance were improved with increasing amount of Ca in the layered perovskite structure and declined with increasing amount of the simple perovskite phase.</P></▼2></▼1>
Yoo, Seonyoung,Jun, Areum,Ju, Young‐,Wan,Odkhuu, Dorj,Hyodo, Junji,Jeong, Hu Young,Park, Noejung,Shin, Jeeyoung,Ishihara, Tatsumi,Kim, Guntae WILEY‐VCH Verlag 2014 Angewandte Chemie Vol.126 No.48
<P><I><B>Doppelperowskite</B></I> werden von G. Kim und Mitarbeitern in ihrer Zuschrift auf S. 13280 ff. als eine neue Klasse von Kathodenmaterialien für Festoxid‐Brennstoffzellen vorgestellt. Die verbesserte Stabilität von NdBa<SUB>0.75</SUB>Ca<SUB>0.25</SUB>Co<SUB>2</SUB>O<SUB>5+<I>δ</I></SUB> beruht auf der erhöhten Elektronenaffinität der beweglichen Sauerstoffspezies sowie der höheren Redoxstabilität, die durch Ca‐Dotierung an den A‐Positionen von NdBaCo<SUB>2</SUB>O<SUB>5+<I>δ</I></SUB> erreicht wird.</P>
Kim, Seona,Choi, Sihyuk,Jun, Areum,Shin, Jeeyoung,Kim, Guntae The Electrochemical Society 2014 Journal of the Electrochemical Society Vol.161 No.14
<P>Among the Ruddlesden-Popper series, La(n+1)NinO(3n+1) (n = 1, 2, and 3) has attracted tremendous attention as an intermediate temperature solid oxide fuel cell (IT-SOFC) cathode because of its favorable properties for realizing high performance. Inter alia, La4Ni3O10-delta (n = 3) has in particular gained recognition as a promising cathode material owing to its high electrical conductivity and cell performance in IT-SOFC applications. The fabrication of nano-sized La4Ni3O10-delta composites requires a low sintering temperature process because high sintering temperature gives rise to solid state reactions between the constituents, which leads to the formation of an undesired electrical insulator and the formation of a low surface area thin-film on the surface. The infiltration method is therefore chosen to fabricate nano-sized La4Ni3O10-delta composites because it can provide reduced particle size of La4Ni3O10-d by separating the sintering process of the cathode from the high temperature sintering process of the electrolyte. In this work, we investigated the electrochemical properties of La4Ni3O10-delta composites prepared by an infiltration method in terms of application as an IT-SOFC cathode material as well as the effect of strontium doping at La sites. (C) The Author(s) 2014. Published by ECS. All rights reserved.</P>
Highly stable lithium metal battery with an applied three-dimensional mesh structure interlayer
Kim, Hyunjin,Gong, Yong Jun,Yoo, Jeeyoung,Kim, Youn Sang The Royal Society of Chemistry 2018 Journal of materials chemistry. A, Materials for e Vol.6 No.32
<P>Lithium metal is one of the most attractive anode materials, due to its high theoretical specific capacity and lowest electrochemical potential. However, low coulombic efficiency and serious safety hazards have still hindered the wide applications of next-generation batteries including Li-S and Li-air. Previous studies have suggested overcoming the problem by applying various structures of current collectors. These structures homogenize the Li ion flux or provide space for volume expansion. However, there are some limitations to solving problems occurring at the Li metal surface, because the current collector is underneath the structures of Li metal. In this work, we propose a facile and cost-effective strategy for stabilizing the lithium metal-electrolyte interface <I>via</I> a three-dimensional stainless steel mesh (SSM) interlayer. Its high specific surface area lowers the local current density and provides an electronic flow path for dead Li. Also, this structure leads to confinement of Li deposits and alleviates volume expansion. As a result, the Li anode with the SSM interlayer operated at current densities of 1 mA cm<SUP>−2</SUP> (1C rate) and 5 mA cm<SUP>−2</SUP>, and it exhibited a longer cycle-life than planar structures in a symmetrical cell configuration.</P>
Kim, Seona,Kim, Chanseok,Lee, Jun Hee,Shin, Jeeyoung,Lim, Tak-Hyoung,Kim, Guntae Elsevier 2017 ELECTROCHIMICA ACTA Vol.225 No.-
<P><B>Abstract</B></P> <P>There is increasing demand for versatile catalysts for direct hydrocarbon utilization with the coming of hydrocarbon economy. The catalysts are required to possess both high catalytic activities and excellent carbon coking tolerance for the hydrocarbon oxidation process. In this regard, we considered Ni-based alloy catalysts, <I>e.g</I>. Ni-Co, Ni-Cu, and Ni-Fe, which are expected to provide synergistic effects from the high catalytic activities of Ni and the high carbon coking tolerance of transition metals. We conduct a systematic investigation of catalytic effects on the electrochemical properties and the carbon coking tolerance of the candidates. Moreover, the binding strengths of H, O, and C species with each alloy catalyst were examined via density functional theory (DFT) calculations, providing insight into the trend of catalytic activity and carbon coking tolerance. In this study, the single cell for the solid oxide fuel cell with Ni-Fe catalyst shows the best electrochemical performance, 0.81 and 0.30Wcm<SUP>−2</SUP> at 700°C under H<SUB>2</SUB> and C<SUB>3</SUB>H<SUB>8</SUB>, respectively, with excellent tolerance against carbon deposition.</P>