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Unexpected Li displacement and suppressed phase transition enabling highly stabilized oxygen redox in P3-type Na layered oxide cathode

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Journal of Energy Chemistry 2023年第10期85卷 144-153,I0006页

作者： Myungeun Choi Hobin Ahn Hyunyoung Park Yongseok Lee Jinho Ahn Bonyoung Ku Junseong Kim Wonseok Ko jungmin kang jung-Keun Yoo Duho Kim Jongsoon Kim Department of Energy Science Sungkyunkwan UniversitySuwon 16419Republic of Korea SKKU Institute of Energy Science and Technology(SIEST) Sungkyunkwan UniversitySuwon 16419Republic of Korea Carbon Composites Department Korea Institute of Materials Science(KIMS)Changwon 51508Republic of Korea Department of Mechanical Engineering(Integrated Engineering Program) Kyung Hee University1732Deogyeong-daeroGiheung-guYongin-siGyeonggi-do 17104Republic of Korea Department of KHU-KIST Convergence Science and Technology Kyung Hee University23Kyunghee-daero Dongdaemun-guSeoul 02447Republic of Korea

Oxygen redox is considered a new paradigm for increasing the practical capacity and energy density of the layered oxide cathodes for Na-ion batteries. However, severe local structural changes and phase transitions during anionic redox reactions lead to poor electrochemical performance with sluggish ***, we propose a synergy of Li-Cu cations in harnessing the full potential of oxygen redox, through Li displacement and suppressed phase transition in P3-type layered oxide cathode. P3-type Na_(0.7)[Li_(0.1)Cu_(0.2)Mn_(0.7)]O_(2) cathode delivers a large specific capacity of ~212 mA h g^(-1)at 15 mA g^(-1). The discharge capacity is maintained up to ~90% of the initial capacity after 100 cycles, with stable occurrence of the oxygen redox in the high-voltage region. Through advanced experimental analyses and first-principles calculations, it is confirmed that a stepwise redox reaction based on Cu and O ions occurs for the charge-compensation mechanism upon charging. Based on a concrete understanding of the reaction mechanism, the Li displacement by the synergy of Li-Cu cations plays a crucial role in suppressing the structural change of the P3-type layered material under the oxygen redox reaction, and it is expected to be an effective strategy for stabilizing the oxygen redox in the layered oxides of Na-ion batteries.

关键词： Layered oxide cathode Oxygen redox reaction Structural stability Li displacement No phase transition

Sarcopenia is associated with Framingham risk score in the Korean population： Korean National Health and Nutrition Examination Survey （KNHANES） 2010-2011

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Journal of Geriatric Cardiology 2015年第4期12卷 366-372页

作者： Chae-Hwa Byeon Kee-Young kang Se-hun kang Eun-Jin Bae Department of Family Medicine DaeDong Hospital Myeongnyun-dong Dongnae-gu Busan South Korea

BACKGROUND:Sarcopenia is a risk factor for metabolic disorders and cardiovascular disease, but the association between sarcopenia and cardiovascular risk factors according to age and obesity status in the general population remains unknown. We thus investigated these associations in the Korean population.;METHODS:We included 8,958 and 8,518 subjects from the fifth Korean National Health and Nutrition Examination Survey (KNHANES) (from 2010 and 2011, respectively). The study was restricted to participants ≥ 20 years old who had completed the health examination survey, including whole body dual-energy X-ray absorptiometry scans. After exclusion, 7,366 subjects (3,188 men, 4,178 women) were included in our final analysis. Age was categorized according to three age groups (20-39, 40-59, and ≥ 60 years), and subjects were categorized according to their sarcopenic and obesity status. Cardiovascular risk was assessed with Framingham risk score (FRS).;RESULTS:The sarcopenic obese group had a higher FRS than the non-sarcopenic obese group, which had a higher FRS than the non-sarcopenic non-obese group. Age-wise, the 20-39 year-old group showed a non-significant association between sarcopenia and FRS. In the 40-59 year-old group, regardless of obesity status, sarcopenic subjects had a higher FRS than non-sarcopenic subjects. In the ≥ 60 year-old group, sarcopenic subjects had a higher FRS than non-sarcopenic subjects for the non-obese group.;CONCLUSIONS:Sarcopenia was associated with cardiovascular disease and may be an early predictor of its susceptibility in both elderly and middle-aged subjects. Thus, management of sarcopenia is necessary to prevent cardiovascular disease.

关键词：健康调查风险评估营养调查韩国肌肉人口心血管疾病分相

Study on wear behavior of plasma electrolytic oxidation coatings on aluminum alloy

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Rare Metals 2006年第Z2期25卷 141-145页

作者： kang Suk-Bong LEE jung-Moo Department of Materials Engineering Korean Institute of Machinery & Materials Gyeongnam 641831 Korea

Thick and hard ceramic coatings were fabricated on A356 aluminum alloy by using plasma electrolytic oxidation(PEO) technique. The microstructure and phase composition of the PEO coatings were examined by using SEM and XRD method. It is found that the PEO coatings are mainly composed of crystalline α-Al2O3 and mullite. The dry sliding wear test of PEO coatings were carried out on a ring-on-ring wear machine. Results shows that there is hardly no wear loss of polished PEO coatings while the wear rate of uncoated aluminum alloy is 4.3×10-5 mm3·(N·m)-1 at a speed of 0.52 m·s-1 and a load of 40 N.

关键词： aluminum alloy plasma electrolytic oxidation ceramic coating wear

Numerical Issues in the Implementation of High Order Polynomial Multi-Domain Penalty Spectral Galerkin Methods for Hyperbolic Conservation Laws

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Communications in Computational Physics 2009年第2期5卷 600-619页

作者： Sigal Gottlieb Jae-hun jung Department of Mathematics University of Massachusetts at DartmouthNorth DartmouthMA 02747-2300USA Department of Mathematics SUNY at BuffaloBuffaloNY14260-2900USA

In this paper,we consider high order multi-domain penalty spectral Galerkin methods for the approximation of hyperbolic conservation *** formulation has a penalty parameter which can vary in space and time,allowing for flexibility in the penalty *** flexibility is particularly advantageous for problems with an inhomogeneous *** show that the discontinuous Galerkin method is equivalent to the multi-domain spectral penalty Galerkin method with a particular value of the penalty *** penalty parameter has an effect on both the accuracy and stability of the *** examine the numerical issues which arise in the implementation of high order multi-domain penalty spectral Galerkin *** coefficient truncation method is proposed to prevent the rapid error growth due to round-off errors when high order polynomials are ***,we show that an inconsistent evaluation of the integrals in the penalty method may lead to growth of *** examples for linear and nonlinear problems are presented.

关键词： High order polynomial Galerkin methods penalty boundary conditions discontinuous Galerkin methods hyperbolic conservation laws round-off errors truncation methods

A Review of David Gottlieb’s Work on the Resolution of the Gibbs Phenomenon

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Communications in Computational Physics 2011年第3期9卷 497-519页

作者： Sigal Gottlieb Jae-hun jung Saeja Kim Mathematics Department University of Massachusetts DartmouthNorth DartmouthMA 02747USA Mathematics Department Suny BuffaloBuffaloNew York 14260-2900USA

Given a piecewise smooth function,it is possible to construct a global expansion in some complete orthogonal basis,such as the Fourier ***,the local discontinuities of the function will destroy the convergence of global approximations,even in regions for which the underlying function is *** global expansions are contaminated by the presence of a local discontinuity,and the result is that the partial sums are oscillatory and feature non-uniform *** characteristic behavior is called the Gibbs ***,David Gottlieb and Chi-Wang Shu showed that these slowly and non-uniformly convergent global approximations retain within them high order information which can be recovered with suitable *** this paper we review the history of the Gibbs phenomenon and the story of its resolution.

关键词： Gibbs phenomenon post-processing Galerkin approximation collocation approximation spectral methods exponential accuracy

Enhanced thermoelectric properties of NbCoSn half-Heuslers through in-situ nanocrystallization of amorphous precursors during the consolidation process

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Journal of Materials Science & Technology 2023年第34期165卷 39-48页

作者： Chanwon jung Kyuseon Jang Hail Park Jeongin Jang Hanhwi Jang Byungchul kang Kitae Park Siyuan Zhang Ruben Bueno Villoro SuDong Park Ho Jin Ryu Yeon Sik jung Min-Wook Oh Christina Scheu Seong-Hoon Yi Pyuck-Pa Choi Department of Materials Science and Engineering Korea Advanced Institute of Science and Technology(KAIST)291 Daehak-roYuseong-guDaejeon 34141Republic of Korea Max-Planck-Institut für Eisenforschung GmbH Düsseldorf 40237Germany Electrical Materials Research Division Energy Conversion Research CenterKorea Electrotechnology Research Institute(KERI)Changwon 51543Republic of Korea Department of Materials Science and Metallurgical Engineering Kyungpook National University80 DaehakroDaegu 41566Republic of Korea Department of Nuclear and Quantum Engineering Korea Advanced Institute of Science and Technology(KAIST)291 Daehak-roYuseong-guDaejeon 34141Republic of Korea Department of Materials Science and Engineering Hanbat National University125 Dongseodae-roYuseong-guDaejeon 34158Republic of Korea

Tailoring nanostructures is a general approach used to obtain enhanced thermoelectric properties for halfHeusler compounds because the wide areas of grain and phase boundaries could be scattering centers that lower lattice thermal ***,a common fabrication method based on the sintering of crystalline precursors crushed from as-cast alloy ingots has limitations in obtaining a homogeneous microstructure without microsized impurity phases,owing to residual elemental segregation from *** this study,we used amorphous NbCoSn alloys as a precursor for the sintered specimen to obtain a homogeneous NbCoSn bulk specimen without microsized impurity phases and segregation,which led to the enhanced Seebeck coefficient due to the high purity of the half-Heusler phase after ***,superplasticity originating from amorphous features enabled the powders to be largely deformed during the sintering process,even at a low sintering temperature(953 K).This resulted in less oxidation at both,the grain boundary and the interior,as the O diffusion pathway was blocked during the sintering *** a result,the NbCoSn0.95Sb0.05 specimen using an amorphous precursor exhibited an enhanced zT of 0.7,due to the increase in the power factor and a decrease in lattice thermal conductivity compared to the specimen using a crystalline precursor.

关键词： Half-Heusler compounds Amorphous Superplasticity Segregation Atom probe tomography

Corrugated surface microparticles with chitosan and levofloxacin for improved aerodynamic performance

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Asian Journal of Pharmaceutical Sciences 2023年第3期18卷 146-158页

作者： Chang-Soo Han Ji-Hyun kang Eun hye Park Hyo-jung Lee So-Jeong Jeong Dong-Wook Kim Chun-Woong Park College of Pharmacy Chungbuk National UniversityCheongju 28160Republic of Korea School of Pharmacy Jeonbuk National UniversityJeonju 54896Republic of Korea College of Pharmacy Wonkwang UniversityIksan 54538Republic of Korea

Corrugated surface microparticles comprising levofloxacin(LEV),chitosan and organic acid were prepared using the 3-combo spray drying *** amount and the boiling point of the organic acid affected the degree of *** this study,we tried to improve the aerodynamic performance and increase aerosolization by corrugated surface microparticle for lung drug delivery efficiency as dry powder ***175 L20 prepared with 175 mmol propionic acid solution was corrugated more than HMF175 L20 prepared with 175 mmol formic acid *** ACI and PIV results showed a significant increase in aerodynamic performance of corrugated *** FPF value of HMP175 L20 was 41.3%±3.9%compared with 25.6%±7.7%of HMF175 *** microparticles also showed better aerosolization,decreased x-axial velocity,and variable *** dissolution of drug formulationswas observed in *** administered to the lungs achieved higher LEV concentrations in the lung fluid than high doses administered *** modification in the polymer-based formulation was achieved by controlling the evaporation rate and improving the inhalation efficiency of DPIs.

关键词： Chitosan Organic acid Levofloxacin Corrugated surface Aerodynamic performance

Analyzing the distinguishing factors that affect childhood obesity in South Korea

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Frontiers of Medicine 2018年第6期12卷 707-716页

作者： So jung Yang hun-Sung Kim Kun-Ho Yoon Department of Medical Informatics College of MedicineThe Catholic University of KoreaSeoul 06591Republic of Korea Division of Endocrinology and Metabolism Department of lnternal MedicineSeoul St.Mary's HospitalCollege of MedicineThe Catholic University of KoreaSeoul 06591Republic of Korea

Understanding obesity in children is crucial because it can lead to adulthood obesity and result in fatal chronic diseases. Distinctive factors associated with obesity in adults have been described, but distinctive factors related to children remain unclear. We analyzed the correlation between the percentage of body mass index and lifestyle habits by conducting surveys on physical, nutritional, and psychological factors, and we used annual physical examination data to compare different traits among elementary school students (n = 197) and middle school students (n = 461). Our study revealed that the computing hours in elementary school students with overweight and obesity were significantly correlated with the percentage of body mass index (r = 0.29 on school days and r = 0.35 on days off, all P0.05) in the computing hours of middle school students with overweight and obesity. Childhood obesity can cause depression and reduce children’s quality of life because of their distorted body perception. In conclusion, physical factors directly affecting childhood obesity and psychological and environmental factors surrounding a child should be considered.

关键词： screen time quality of life eating habits childhood obesity percentage of body mass index

Antiphospholipid syndrome with renal and splenic infarction after blunt trauma:A case report

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World Journal of Clinical Cases 2022年第26期10卷 9404-9410页

作者： Na-A Lee Eui-Sung Jeong Hyun-Seok Jang Yun-Chul Park Ji-Hyoun kang jung-Chul Kim Young-Goun Jo Division of Trauma Department of SurgeryChonnam National University Medical School and HospitalGwangju 61469South Korea Division of Rheumatology Department of Internal MedicineChonnam National University Medical School and HospitalGwangju 61469South Korea

BACKGROUND In trauma patients,bleeding is an immediate major *** the same time,there are few cases of acute vascular occlusion after blunt trauma,and it is unclear what assessment and diagnosis should be considered for these ***,we describe a patient diagnosed with antiphospholipid syndrome after a hypercoagulable workup for acute renal and splenic vascular occlusion due to blunt *** SUMMARY A 20-year-old man was admitted to the emergency department with abdominal pain after hitting a tree while riding a sled 10 h *** had no medical *** investigations revealed occlusion of the left renal artery with global infarction of the left kidney and occlusion of branches of the splenic artery with infarction of the central portion of the *** revascularization of the left renal artery occlusion through percutaneous transluminal angioplasty failed due to difficulty in passing the wire through the total *** the presence of acute multivascular occlusions in a young man with low cardiovascular risk,additional laboratory tests were performed to evaluate *** results suggested a high possibility of antiphospholipid *** with a subcutaneous injection of enoxaparin was started and changed to oral warfarin after two *** diagnosis was confirmed,and he continued to visit the rheumatology outpatient clinic while taking *** A hypercoagulable workup can be considered in trauma patients with acute multivascular occlusion,especially in young patients with low cardiovascular risk.

关键词： Wounds and injuries Wounds Nonpenetrating Antiphospholipid syndrome Renal artery obstruction Splenic infarction Case reports