1
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Park JK, Yang SM, Logan NC, Hu Q, Zhu C, Zarnstorff MC, Nazikian R, Paz-Soldan C, Jeon YM, Ko WH. Quasisymmetric Optimization of Nonaxisymmetry in Tokamaks. Phys Rev Lett 2021; 126:125001. [PMID: 33834790 DOI: 10.1103/physrevlett.126.125001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 12/02/2020] [Accepted: 01/25/2021] [Indexed: 06/12/2023]
Abstract
Predictive 3D optimization reveals a novel approach to modify a nonaxisymmetric magnetic perturbation to be entirely harmless for tokamaks, by essentially restoring quasisymmetry in perturbed particle orbits as much as possible. Such a quasisymmetric magnetic perturbation (QSMP) has been designed and successfully tested in the KSTAR and DIII-D tokamaks, demonstrating no performance degradation despite the large overall amplitudes of nonaxisymmetric fields and strong response otherwise expected in the tested plasmas. The results indicate that a quasisymmetric optimization is a robust path of error field correction across the resonant and nonresonant field spectrum in a tokamak, leveraging the prevailing concept of quasisymmetry for general 3D plasma confinement systems such as stellarators. The optimization becomes, in fact, a simple eigenvalue problem to the so-called torque response matrices if a perturbed equilibrium is calculated consistent with nonaxisymmetric neoclassical transport.
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Affiliation(s)
- J-K Park
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543, USA
| | - S M Yang
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543, USA
| | - N C Logan
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543, USA
| | - Q Hu
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543, USA
| | - C Zhu
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543, USA
| | - M C Zarnstorff
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543, USA
| | - R Nazikian
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543, USA
| | - C Paz-Soldan
- General Atomics, San Diego, California 92121, USA
| | - Y M Jeon
- National Fusion Research Institute, Daejeon 305-333, Republic of Korea
| | - W H Ko
- National Fusion Research Institute, Daejeon 305-333, Republic of Korea
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2
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Xiao WW, Evans TE, Tynan GR, Yoon SW, Jeon YM, Ko WH, Nam YU, Oh YK. Propagation Dynamics Associated with Resonant Magnetic Perturbation Fields in High-Confinement Mode Plasmas inside the KSTAR Tokamak. Phys Rev Lett 2017; 119:205001. [PMID: 29219375 DOI: 10.1103/physrevlett.119.205001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Indexed: 06/07/2023]
Abstract
The propagation dynamics of resonant magnetic perturbation fields in KSTAR H-mode plasmas with injection of small edge perturbations produced by a supersonic molecular beam injection is reported for the first time. The results show that the perturbation field first excites a plasma response on the q=3 magnetic surface and then propagates inward to the q=2 surface with a radially averaged propagation velocity of resonant magnetic perturbations field equal to 32.5 m/ s. As a result, the perturbation field brakes the toroidal rotation on the q=3 surface first causing a momentum transport perturbation that propagates both inward and outward. A higher density fluctuation level is observed. The propagation velocity of the resonant magnetic perturbations field is larger than the radial propagation velocity of the perturbation in the toroidal rotation.
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Affiliation(s)
- W W Xiao
- Institute for Fusion Theory and Simulation, Zhejiang University, Hangzhou 310027, China
| | - T E Evans
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608, USA
| | - G R Tynan
- Center for Energy Research, University of California San Diego, La Jolla, California 92093, USA
| | - S W Yoon
- National Fusion Research Institute, Gwahango, 113, Daejeon, 305-333, Korea
| | - Y M Jeon
- National Fusion Research Institute, Gwahango, 113, Daejeon, 305-333, Korea
| | - W H Ko
- National Fusion Research Institute, Gwahango, 113, Daejeon, 305-333, Korea
| | - Y U Nam
- National Fusion Research Institute, Gwahango, 113, Daejeon, 305-333, Korea
| | - Y K Oh
- National Fusion Research Institute, Gwahango, 113, Daejeon, 305-333, Korea
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3
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Yoon SW, England AC, Kim WC, Yonekawa H, Bak JG, Park BH, Kim J, You KI, Jeon YM, Hahn SH, Oh YK, Chung J, Lee KD, Lee HJ, Leuer JA, Eidietis NW. Effect of Magnetic Materials on the In-Vessel Magnetic Configuration in KSTAR. Fusion Science and Technology 2017. [DOI: 10.13182/fst13-706] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- S. W. Yoon
- National Fusion Research Institute, 113 Gwahangno, Yusung-Gu, Daejeon, 305-333, Korea
| | - A. C. England
- National Fusion Research Institute, 113 Gwahangno, Yusung-Gu, Daejeon, 305-333, Korea
| | - W. C. Kim
- National Fusion Research Institute, 113 Gwahangno, Yusung-Gu, Daejeon, 305-333, Korea
| | - H. Yonekawa
- National Fusion Research Institute, 113 Gwahangno, Yusung-Gu, Daejeon, 305-333, Korea
| | - J. G. Bak
- National Fusion Research Institute, 113 Gwahangno, Yusung-Gu, Daejeon, 305-333, Korea
| | - B. H. Park
- National Fusion Research Institute, 113 Gwahangno, Yusung-Gu, Daejeon, 305-333, Korea
| | - J. Kim
- National Fusion Research Institute, 113 Gwahangno, Yusung-Gu, Daejeon, 305-333, Korea
| | - K. I. You
- National Fusion Research Institute, 113 Gwahangno, Yusung-Gu, Daejeon, 305-333, Korea
| | - Y. M. Jeon
- National Fusion Research Institute, 113 Gwahangno, Yusung-Gu, Daejeon, 305-333, Korea
| | - S. H. Hahn
- National Fusion Research Institute, 113 Gwahangno, Yusung-Gu, Daejeon, 305-333, Korea
| | - Y. K. Oh
- National Fusion Research Institute, 113 Gwahangno, Yusung-Gu, Daejeon, 305-333, Korea
| | - J. Chung
- National Fusion Research Institute, 113 Gwahangno, Yusung-Gu, Daejeon, 305-333, Korea
| | - K. D. Lee
- National Fusion Research Institute, 113 Gwahangno, Yusung-Gu, Daejeon, 305-333, Korea
| | - H. J. Lee
- National Fusion Research Institute, 113 Gwahangno, Yusung-Gu, Daejeon, 305-333, Korea
| | - J. A. Leuer
- General Atomics, 3550 General Atomics Court, San Diego, California 92121
| | - N. W. Eidietis
- General Atomics, 3550 General Atomics Court, San Diego, California 92121
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4
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Ko WH, Lee HH, Jeon YM, Ida K, Lee JH, Yoon SW, Lee KD, Bae YS, Oh YK, Kwak JG. Rotation characteristics during the resonant magnetic perturbation induced edge localized mode suppression on the KSTAR. Rev Sci Instrum 2014; 85:11E413. [PMID: 25430320 DOI: 10.1063/1.4890402] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Measuring rotation profiles with a reliable spatial resolution is one of the critical diagnostics in understanding the plasma behavior especially for the edge transport. In the KSTAR experiments, it has been consistently observed from the charge exchange spectroscopy measurements that the magnetic perturbations not only suppresses edge localized modes (ELMs) but also reduces toroidal rotations. In this paper, toroidal velocities of the carbon impurity and their profile evolutions during ELMy and ELM-suppressed phases are presented. The rotation profiles are shown to collapse immediately after an ELM burst and continue to build up until the next burst that accompanies another collapse. Toroidal rotations following the resonant magnetic perturbations applications are observed to be reduced along with the ELMs suppressed.
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Affiliation(s)
- Won-Ha Ko
- National Fusion Research Institute, Daejeon, South Korea
| | - H H Lee
- National Fusion Research Institute, Daejeon, South Korea
| | - Y M Jeon
- National Fusion Research Institute, Daejeon, South Korea
| | - K Ida
- National Institute for Fusion Science, Nagoya, Japan
| | - J H Lee
- National Fusion Research Institute, Daejeon, South Korea
| | - S W Yoon
- National Fusion Research Institute, Daejeon, South Korea
| | - K D Lee
- National Fusion Research Institute, Daejeon, South Korea
| | - Y S Bae
- National Fusion Research Institute, Daejeon, South Korea
| | - Y K Oh
- National Fusion Research Institute, Daejeon, South Korea
| | - J G Kwak
- National Fusion Research Institute, Daejeon, South Korea
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5
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Lee JH, Oh S, Lee WR, Ko WH, Kim KP, Lee KD, Jeon YM, Yoon SW, Cho KW, Narihara K, Yamada I, Yasuhara R, Hatae T, Yatsuka E, Ono T, Hong JH. Edge profile measurements using Thomson scattering on the KSTAR tokamak. Rev Sci Instrum 2014; 85:11D407. [PMID: 25430170 DOI: 10.1063/1.4890258] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
In the KSTAR Tokamak, a "Tangential Thomson Scattering" (TTS) diagnostic system has been designed and installed to measure electron density and temperature profiles. In the edge system, TTS has 12 optical fiber bundles to measure the edge profiles with 10-15 mm spatial resolution. These 12 optical fibers and their spatial resolution are not enough to measure the pedestal width with a high accuracy but allow observations of L-H transition or H-L transitions at the edge. For these measurements, the prototype ITER edge Thomson Nd:YAG laser system manufactured by JAEA in Japan is installed. In this paper, the KSTAR TTS system is briefly described and some TTS edge profiles are presented and compared against the KSTAR Charge Exchange Spectroscopy and other diagnostics. The future upgrade plan of the system is also discussed in this paper.
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Affiliation(s)
- J H Lee
- National Fusion Research Institute, Daejeon, South Korea
| | - S Oh
- National Fusion Research Institute, Daejeon, South Korea
| | - W R Lee
- National Fusion Research Institute, Daejeon, South Korea
| | - W H Ko
- National Fusion Research Institute, Daejeon, South Korea
| | - K P Kim
- National Fusion Research Institute, Daejeon, South Korea
| | - K D Lee
- National Fusion Research Institute, Daejeon, South Korea
| | - Y M Jeon
- National Fusion Research Institute, Daejeon, South Korea
| | - S W Yoon
- National Fusion Research Institute, Daejeon, South Korea
| | - K W Cho
- National Fusion Research Institute, Daejeon, South Korea
| | - K Narihara
- National Institute for Fusion Science, Nagoya, Japan
| | - I Yamada
- National Institute for Fusion Science, Nagoya, Japan
| | - R Yasuhara
- National Institute for Fusion Science, Nagoya, Japan
| | - T Hatae
- Japan Atomic Energy Agency, Naka, Japan
| | - E Yatsuka
- Japan Atomic Energy Agency, Naka, Japan
| | - T Ono
- Japan Atomic Energy Agency, Naka, Japan
| | - J H Hong
- Department of Physics, KAIST, South Korea
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6
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Park JK, Jeon YM, Menard JE, Ko WH, Lee SG, Bae YS, Joung M, You KI, Lee KD, Logan N, Kim K, Ko JS, Yoon SW, Hahn SH, Kim JH, Kim WC, Oh YK, Kwak JG. Rotational resonance of nonaxisymmetric magnetic braking in the KSTAR tokamak. Phys Rev Lett 2013; 111:095002. [PMID: 24033042 DOI: 10.1103/physrevlett.111.095002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2013] [Indexed: 06/02/2023]
Abstract
One of the important rotational resonances in nonaxisymmetric neoclassical transport has been experimentally validated in the KSTAR tokamak by applying highly nonresonant n=1 magnetic perturbations to rapidly rotating plasmas. These so-called bounce-harmonic resonances are expected to occur in the presence of magnetic braking perturbations when the toroidal rotation is fast enough to resonate with periodic parallel motions of trapped particles. The predicted and observed resonant peak along with the toroidal rotation implies that the toroidal rotation in tokamaks can be controlled naturally in favorable conditions to stability, using nonaxisymmetric magnetic perturbations.
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Affiliation(s)
- J-K Park
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543, USA
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7
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Yun GS, Park HK, Lee W, Choi MJ, Choe GH, Park S, Bae YS, Lee KD, Yoon SW, Jeon YM, Domier CW, Luhmann NC, Tobias B, Donné AJH. Appearance and dynamics of helical flux tubes under electron cyclotron resonance heating in the core of KSTAR plasmas. Phys Rev Lett 2012; 109:145003. [PMID: 23083252 DOI: 10.1103/physrevlett.109.145003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2011] [Indexed: 06/01/2023]
Abstract
Dual (or sometimes multiple) flux tubes (DFTs) have been observed in the core of sawtoothing KSTAR tokamak plasmas with electron cyclotron resonance heating. The time evolution of the flux tubes visualized by a 2D electron cyclotron emission imaging diagnostic typically consists of four distinctive phases: (1) growth of one flux tube out of multiple small flux tubes during the initial buildup period following a sawtooth crash, resulting in a single dominant flux tube along the m/n=1/1 helical magnetic field lines, (2) sudden rapid growth of another flux tube via a fast heat transfer from the first one, resulting in approximately identical DFTs, (3) coalescence of the two flux tubes into a single m/n=1/1 flux tube resembling the internal kink mode in the normal sawteeth, which is explained by a model of two current-carrying wires confined on a flux surface, and (4) fast localized crash of the merged flux tube similar to the standard sawtooth crash. The dynamics of the DFTs implies that the internal kink mode is not a unique prerequisite to the sawtooth crash, providing a new insight on the control of the sawtooth.
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Affiliation(s)
- G S Yun
- POSTECH, Pohang 790-784, Korea.
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8
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Yang YB, Jeon YM, Kim JU, Cho J. Diblock and triblock copolymer thin films on a substrate with controlled selectivity. Eur Phys J E Soft Matter 2012; 35:86. [PMID: 22972228 DOI: 10.1140/epje/i2012-12086-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2012] [Revised: 08/01/2012] [Accepted: 08/02/2012] [Indexed: 06/01/2023]
Abstract
Using self-consistent field theory (SCFT), morphology development in symmetric linear ABC triblock copolymer films on neutral and selective substrates has been studied, and it is compared with the triblock copolymer morphologies in bulk. In particular, the effects of the substrate preferable to B (interior) block on nanopattern formation of the copolymer films are of our central interest. Here, we report various nanopatterns with tunable square morphologies. The domain patterns are much more diverse than those parallel to the substrate with substrate selectivity for end-block or those vertical to the substrate without substrate selectivity. Furthermore, in order to figure out an economical and efficient way to fabricate useful passive pattern transfer layers, which have potential applications in microelectronic processes and ultrahigh density storage media, we propose a two-step strategy and scrutinize the conditions for generating square symmetries using cylinder-forming or lamella-forming AB diblock copolymers deposited on substrates created from ABC triblock copolymer films. It is found that a thinner film with weak incompatibility can produce square patterns.
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Affiliation(s)
- Y-B Yang
- School of Mechanical and Advanced Materials Engineering, UNIST, Ulsan, Korea
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9
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Kim H, Suh KS, Jeon YM, Park MS, Choi Y, Mori S, Hong G, Lee HW, Yi NJ, Lee KW. Partial splenic artery embolization for thrombocytopenia and uncontrolled massive ascites after liver transplantation. Transplant Proc 2012; 44:755-6. [PMID: 22483487 DOI: 10.1016/j.transproceed.2012.01.066] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Thrombocytopenia (platelet < 60,000/mm(3)) and uncontrolled massive ascites (ascitic fluid > 1000 mL/d over 10 days) after liver transplantation (OLT), although uncommon, usually represent serious complications. Splenectomy is a useful treatment despite its many side effects. Recently, partial splenic artery embolization (PSAE) is considered to be a nonsurgical, less invasive treatment. In this study, we retrospectively reviewed the results of PSAE after OLT. Between October 2008 and February 2010, 11 patients underwent PSAE after OLT due to thrombocytopenia (n = 6) or refractory ascites (RA; n = 5). Six patients (54.5%) were males and 3 (27.3%) were children. The primary liver disease was virus-related liver cirrhosis (n = 6), biliary atresia (n = 3), fulminant hepatitis (n = 1), or alcoholic liver cirrhosis (n = 1). Seven grafts were from living and four from deceased donors. The major axial size of spleen was 12.1 to 23.4 cm and its average embolized volume, 76.4% (range = 70%-80%). As the result, the platelet count significantly increased after PSAE in all patients maintaining values greater than 100,000/mm(3) in four thrombocytopenic patients (66.7%). Cases of RA showed marked decreases after PSAE (100%). The follow-up was 6 to 28 months. After PSAE, patients experienced abdominal pain (n = 9, 81.8%), fever (n = 2, 18.2%), and abdominal distension (n = 2, 18.2%). However, there was no serious complication after PSAE such as splenic abscess, rupture, pancreatic infarction, sepsis, or death. In conclusion, PSAE was effective and safe and can be the choice for thrombocytopenia or RA related to hypersplenism after OLT.
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Affiliation(s)
- H Kim
- Department of Surgery, Seoul National University College of Medicine, Chongno-gu, Seoul, Korea
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10
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Jeon YM, Park JK, Yoon SW, Ko WH, Lee SG, Lee KD, Yun GS, Nam YU, Kim WC, Kwak JG, Lee KS, Kim HK, Yang HL. Suppression of edge localized modes in high-confinement KSTAR plasmas by nonaxisymmetric magnetic perturbations. Phys Rev Lett 2012; 109:035004. [PMID: 22861864 DOI: 10.1103/physrevlett.109.035004] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2011] [Indexed: 06/01/2023]
Abstract
Edge localized modes (ELMs) in high-confinement mode plasmas were completely suppressed in KSTAR by applying n=1 nonaxisymmetric magnetic perturbations. Initially, the ELMs were intensified with a reduction of frequency, but completely suppressed later. The electron density had an initial 10% decrease followed by a gradual increase as ELMs were suppressed. Interesting phenomena such as a saturated evolution of edge T(e) and broadband changes of magnetic fluctuations were observed, suggesting the change of edge transport by the applied magnetic perturbations.
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Affiliation(s)
- Y M Jeon
- National Fusion Research Institute, Daejeon, Korea.
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11
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Cho GB, Choi SY, Noh JP, Jeon YM, Jung KT, Nam TH. Dependence of milling time on electrochemical properties of nano Si electrodes prepared by ball-milling. J Nanosci Nanotechnol 2011; 11:6262-6265. [PMID: 22121698 DOI: 10.1166/jnn.2011.4332] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Morphology, crystallinity and electrochemical properties of Si powders fabricated by a mechanical milling process with milling time of 6-40 h were investigated by means of FESEM, XRD, Raman, TEM and cell test. Average size of Si powders was reduced to sub-micrometer scale after 10 h-milling and 40 nm-Si powders could be obtained at 48 h-milling. With increasing milling time, Si powders mostly changes from crystalline Si to amorphous one and the content of amorphous Si was increased. TEM result showed that a negligiable amount of crystalline Si remained even after 48 h-milling. Si electrode with 48 h-milled Si powders exhibited the best electrochemical properties in terms of capacity, efficiency and cycle performance: initial capacity of 3025 mAh g(-1), coulrombic efficiency of 79.4% and the capacity retention of 1000 mAh g(-1) (at 130 cycles). The good electrochemical properties of nano- and amorphous-Si are due to the high resistance against volume change and good reversibility of Li ion.
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Affiliation(s)
- G B Cho
- School of Materials Science and Engineering and ERI, Gyeongsang National University, Gazwadong 900, Jinju, Gyeongnam 660-701, Korea
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12
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Choi MJ, Yun GS, Park HK, Jeon YM, Jeong SH. Relatively scaled ECE temperature profiles of KSTAR plasmas. Rev Sci Instrum 2010; 81:10D934. [PMID: 21033962 DOI: 10.1063/1.3479005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
A scheme to obtain relatively scaled profiles of electron cyclotron emission (ECE) temperature directly from uncalibrated raw radiometer data is proposed and has been tested for the 2009 campaign KSTAR plasmas. The proposed method utilizes a position controlled system to move the plasma adiabatically and compares ECE radiometer channels at the same relative radial positions assuming the profile consistency during the adiabatic change. This scaling method is an alternative solution when an absolute calibration is unreliable or too time consuming. The application to the two dimensional ECE imaging data, wherein calibration is extremely difficult, may also prove to be useful.
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Affiliation(s)
- M J Choi
- Department of Physics, Pohang University of Science and Technology, Pohang, Gyungbuk 790-784, South Korea
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13
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Nam YU, Chung J, Jeon YM. Estimation of plasma position from tangentially viewed images on a toroidally symmetric device. Rev Sci Instrum 2010; 81:093505. [PMID: 20886980 DOI: 10.1063/1.3482056] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Images of plasma from a fast-framing camera are the most intuitive and reliable data to understand the status of tokamak plasmas. Generation, movement, size variation, and disruptions of plasmas can be clearly observed from these images. However, it is not a simple task to obtain the exact positions and sizes of plasmas using these images because measured two-dimensional images inevitably lose the three-dimensional position information of their targets. In this paper, the exact positions and sizes of plasmas have been calculated from tangentially viewed images using the toroidal symmetry of the plasma in the Korea Superconducting Tokamak Advanced Research (KSTAR) device. The positions and sizes of the plasmas have been manually determined with displayed cursors on images and automatically determined using a correlation factor with calculated virtual plasma images as well. These two results correspond well with each other. The estimated positions have also been compared with those obtained from magnetic diagnostics analysis.
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Affiliation(s)
- Y U Nam
- National Fusion Research Institute, Gwahangno 113, Daejeon 305-333, South Korea.
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14
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Kwon JS, Kim ST, Jeon YM, Choi JH. Effect of botulinum toxin type A injection into human masseter muscle on stimulated parotid saliva flow rate. Int J Oral Maxillofac Surg 2009; 38:316-20. [PMID: 19231136 DOI: 10.1016/j.ijom.2009.01.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2007] [Revised: 11/02/2008] [Accepted: 01/16/2009] [Indexed: 11/28/2022]
Abstract
Botulinum toxin type A (BTX-A) injection into the masseter muscles is used to treat masseteric hypertrophy. No serious side effects of BTX-A have been reported, but patients sometimes complain of xerostomia. The aim of this study was to evaluate the effect of injecting BTX-A into the masseter for the treatment of masseteric hypertrophy on the flow of saliva from the parotid gland. 34 volunteers enrolled in this study. A total of 25 units of BTX-A was injected into each side bilaterally at two points at the center of the lower third of the masseter muscle. Saliva was collected from the parotid gland over a period of 10 min to determine the flow rate for 18 weeks after injection. The flow rate was calculated by dividing the amount in milliliters by the collection time in minutes. There were no significant changes in the stimulated parotid saliva flow at 4, 8, 12 or 18 weeks compared with the baseline. Within this limited study, it can be concluded that BTX-A injection into the masseter does not cause any significant decrease in the production of saliva from the parotid gland.
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Affiliation(s)
- J S Kwon
- TMJ and Orofacial Pain Clinic, Department of Oral Diagnosis & Oral Medicine, College of Dentistry, Yonsei University, Seoul, Korea
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15
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Koo SH, Kwon KC, Shin SY, Jeon YM, Park JW, Kim SH, Noh SM. Genetic alterations of gastric cancer: comparative genomic hybridization and fluorescence In situ hybridization studies. Cancer Genet Cytogenet 2000; 117:97-103. [PMID: 10704677 DOI: 10.1016/s0165-4608(99)00152-1] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Genetic changes leading to the development of gastric cancers are still in dispute. In the following study, we used comparative genomic hybridization (CGH) to screen for DNA copy number changes along all chromosomes in 37 gastric carcinomas, and fluorescence in situ hybridization (FISH) with the C-MYC and TP53 probes in 14 cases for comparison. The aim of this study was to identify those chromosome regions that contain genes important for the development of gastric carcinomas and to identify genetic markers associated with tumor progression. The most often involved gains were 2q, 7pq, 8pq, 13q, 17q, 18q, and 20pq. The most commonly deleted regions were 17p. The pattern of genetic changes was different depending on the existence of nodal metastasis and histologic types. Gains in 8q and losses in 17p were the most common features of the CGH changes. However, only 3 among the available 10 cases (30%) showed an amplification of the C-MYC gene by FISH. Allelic loss of TP53 was found in 2 of 4 cases (50%). This difference might be due to another rearrangement of these 2 genes which cannot be detected by FISH, or other possible genes in that area may be involved in the tumorigenesis and nodal metastasis of gastric carcinomas.
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Affiliation(s)
- S H Koo
- Department of Clinical Pathology, Chungnam National University Hospital, Taejon, South Korea
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16
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Abstract
A decrease of 1-2 degrees C core temperature provides protection against cerebral ischemia. However, shivering usually prevents reduction in core temperature in unanesthetized patients. Therefore, it was tested whether facial and airway heating increases the shivering threshold and enables core cooling in unanesthetized patients. Nine trials were performed on seven healthy male volunteers. Each subject was positioned supine on a circulating-water mattress (8-15 degrees C) with a convective-air coverlet (15-18 degrees C) extending from the neck to the feet. A dynamic study protocol governed by individualized physiological responses was used. Focal facial (and airway) warming was employed to suppress involuntary motor activity (muscle tensing, shivering) and, thereby, enabling noninvasive cooling to lower the core temperature. The following parameters were monitored: 1) heart rate, 2) blood pressure, 3) core temperature (tympanic, axilla, and rectal), 4) cutaneous temperatures, and 5) a subjective shiver index (scale 1-10). In three, electromyograms and infrared thermographs were also obtained. Upon cooling without facial and airway warming, involuntary motor activity increased until it was widespread. This vigorous motor activity prevented any significant lowering of core temperature or caused it to slightly increase. Subsequently, in all subjects, within seconds after the application of facial focal warming, motor activity was suppressed almost completely, and within minutes core temperatures significantly decreased. Preliminary studies described here indicate that focal facial warming applied during active whole body cooling to initiate mild hypothermia might minimize the need to pharmacologically suppress involuntary motor activity. Such a procedure might be useful for initiating as soon as possible (such as during emergency transport), cerebral mild hypothermia in order to maximize protection and thus improve outcome in neurologically injured patients (head trauma, stroke).
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Affiliation(s)
- P A Iaizzo
- Department of Anesthesiology, University of Minnesota, Minneapolis 55455, USA
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17
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Koo SH, Kwon KC, Ihm CH, Jeon YM, Park JW, Sul CK. Detection of genetic alterations in bladder tumors by comparative genomic hybridization and cytogenetic analysis. Cancer Genet Cytogenet 1999; 110:87-93. [PMID: 10214355 DOI: 10.1016/s0165-4608(98)00193-9] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Comparative genomic hybridization (CGH) and conventional cytogenetic karyotyping were used to screen for losses and gains of DNA sequences along all chromosome arms in 16 bladder tumors. Cytogenetic results were highly complex. The most frequently affected chromosomes were 5, 8, 9, 21, and Y as determined by karyotyping. There was close correlation between the CGH data and cytogenetic results in near-diploid tumors with simple karyotypes. However, some unexpected results were observed by CGH in tumors with several composite clones. Common amplification of copy numbers of DNA sequences by CGH were seen at 1q, 3q, 4q, 5p, 6p/q, 7p, 8q, 11q, 12q, 13q, 17q, 18q, and 20p/q (more than 20% of cases). High level amplification was noted at 1p32, 3p21, 3q24, 4q26, 8q21-qter, 11q14-22, 12q15-21, 12q21-24, 13q21-31, 17q22, and 18q22. Deletions were noted at 2q21-qter. 4q13-23, 5q, 8p12-22, 9p/q, and 11p13-15 (more than 20% of cases). Although most amplifications and deletions have been previously described in the literature, our study showed some intriguing and uncommon regions, different from those found in past studies. These were the amplification of 7p, 8q, 11q14-qter 12q24-24, 13q21-31, and 18q22, and deletion on 4q13-23, even though loss of heterozygosity was not detected at this locus. In spite of the very complex pattern of genetic changes in bladder tumors, most of these uncommon aberrations have to be implicated in bladder tumors, and further molecular genetic methods are necessary to establish whether the chromosomal regions contain candidate genes which contributed to the initiation and progression of bladder tumors.
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Affiliation(s)
- S H Koo
- Department of Clinical Pathology and Urology, Chungnam National University Hospital, Taejon, South Korea
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18
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Kim HH, Lee DE, Shin JN, Lee YS, Jeon YM, Chung CH, Ni J, Kwon BS, Lee ZH. Receptor activator of NF-kappaB recruits multiple TRAF family adaptors and activates c-Jun N-terminal kinase. FEBS Lett 1999; 443:297-302. [PMID: 10025951 DOI: 10.1016/s0014-5793(98)01731-1] [Citation(s) in RCA: 100] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Receptor activator of NF-kappaB (RANK) is a recently cloned member of the tumor necrosis factor receptor (TNFR) superfamily, and its function has been implicated in osteoclast differentiation and dendritic cell survival. Many of the TNFR family receptors recruit various members of the TNF receptor-associated factor (TRAF) family for transduction of their signals to NF-kappaB and c-Jun N-terminal kinase. In this study, the involvement of TRAF family members and the activation of the JNK pathway in signal transduction by RANK were investigated. TRAF1, 2, 3, 5, and 6 were found to bind RANK in vitro. Association of RANK with each of these TRAF proteins was also detected in vivo. Expression of RANK in cultured cells also induced the activation of JNK, which was blocked by a dominant-negative form of JNK. Furthermore, by employing various C-terminal deletion mutants of RANK, the regions responsible for TRAF interaction and JNK activation were identified. TRAF5 was determined to bind to the C-terminal 11 amino acids and the other TRAF members to a region N-terminal to the TRAF5 binding site. The domain responsible for JNK activation was localized to the same region where TRAF1, 2, 3, and 6 bound, which suggests that these TRAF molecules might mediate the RANK-induced JNK activation.
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Affiliation(s)
- H H Kim
- Department of Microbiology and Immunology, Chosun University Dental School, Kwangju, South Korea
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Park JG, Lee JH, Kang MS, Park KJ, Jeon YM, Lee HJ, Kwon HS, Park HS, Yeo KS, Lee KU. Characterization of cell lines established from human hepatocellular carcinoma. Int J Cancer 1995; 62:276-82. [PMID: 7543080 DOI: 10.1002/ijc.2910620308] [Citation(s) in RCA: 113] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
We characterized 8 human hepatocellular-carcinoma cell lines established from the primary tumors of Korean patients. All lines showed substrate adherence and one line from anaplastic tumor also grew as floating aggregates. Most cultured cells maintained many morphological characteristics of the original tumors from which they were derived. Doubling times varied from 34 to 72 hr. All lines showed relatively high viability and were not contaminated with Mycoplasma or bacteria. All lines showed aneuploidy and were proven to be unique by DNA fingerprinting analysis. Hepatitis-B-virus (HBV) DNA was integrated in the genomes of all lines. Two of the cell lines (SNU-354, SNU-368) showed expression of HBV and HBVx (HBx) transcripts. SNU-354 strongly expressed albumin, and SNU-368 expressed transferrin and insulin-like growth factor II. No lines produced alpha-fetoprotein at the RNA and protein level. These cell lines represent useful tools for in vitro studies related to hepatocellular carcinoma.
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Affiliation(s)
- J G Park
- Laboratory of Cell Biology, Korean Cell Line Research Foundation, Seoul
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