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Comparison of laser iridotomy using short duration532-nm Nd: YAG laser (PASCAL) vs conventional laser in dark irides

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International Journal of Ophthalmology(English edition) 2015年第2期8卷 288-291页

作者： Hye Jin chung hae.young Park Su-young Kim HanGil Eye Hospital Department of Ophthalmology and Visual Science College of Medicine the Catholic University of Korea

AIM: To evaluate the outcome of laser iridotomy using532-nm Nd: YAG laser(PASCAL) with short pulse duration and Nd: YAG laser compared to conventional combined laser ***: Retrospective, nonrandomized, comparative case series. Forty-five eyes of 34 patients underwent laser iridotomy. Twenty-two eyes underwent iridotomy using short duration PASCAL and Nd: YAG laser, and 23 eyes underwent iridotomy using conventional combined laser method. The average settings of PASCAL were60 μm and 700-900 m W with a short duration of 0.01 s to reduce the total applied energy. The conventional laser was 50 μm and 700-900 m W for 0.1s. After photocoagulation with these laser, the Nd: YAG laser was added in each group. Endothelial cell counts of preiridotomy and 2mo after iridotomy were measured and ***: All eyes completed iridotomy *** total energy used in the PASCAL group was 1.85 ±1.17 J. Compared to conventional laser 13.25 ±1.67 J, the energy used was very small due to the short exposure time of PASCAL. Endothelial cell counts were reduced by0.88% in the PASCAL group and 6.72% in the conventional laser group(P =0.044). The change in corneal endothelial cell counts before and after iridotomy was significant in conventional combined laser iridotomy group(P =0.004).CONCLUSION: Combined PASCAL and Nd:YAG laseriridotomy is an effective and safe technique in the dark brown irides of Asians. Furthermore, the short duration of exposure in PASCAL offers the advantages of reducing the total energy used and minimizing the corneal damage.

关键词： endothelium laser iridotomy 532-nm Nd: YAG laser

Effect of Deformation Temperature on Microstructure and Mechanical Properties of AZ31 Mg Alloy Processed by Differential-Speed Rolling

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Journal of Materials Science & Technology 2015年第5期31卷 498-503页

作者： Mosab Kaseem Bong Kwon chung hae Woong Yang Kotiba Hamad young Gun Ko School of Materials Science and Engineering Yeungnam University

A differential-speed rolling(DSR) was applied to AZ31 magnesium alloy sample at different rolling temperatures of 473,523,573,and 623 K with 1-pass and 2-pass *** microstructural evolution and mechanical properties of the deformed samples were *** rolling temperature was found to be an important parameter affecting the microstructural *** DSR at 473 K,the microstructure was more homogeneous than that obtained after deformation by equal-speed rolling(ESR).The fully recrystallized microstructures were generated after DSR at 573 and 623 *** to mechanical properties,the yield strength(YS) and ultimate tensile strength(UTS) decreased monotonously with increasing rolling *** contrast,the elongation of the DSR-deformed samples was improved as the rolling temperature *** strain hardening exponent(n) calculated by Hollomon equation increased with increasing the rolling temperature,which would explain an increase in the uniform elongation.

关键词： Differential-speed rolling Magnesium alloy Mechani

Influence of the electrolyte conductivity on the critical current density and the breakdown voltage

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Chinese Journal of Chemical Engineering 2023年第7期59卷 169-175页

作者： hae-Kyun Park Dong-Hyuk Park Bum-Jin chung Department of Nuclear Engineering Kyung Hee University 1732 Deogyeong-daeroGiheung-guYongin-siGyeonggi-do 17104Korea

The work investigates influence of the electrolyte conductivity on the onset of partial contact glow discharge electrolysis(CGDE)in a water *** current density(CCD)and breakdown voltage were measured together with in situ observation of hydrogen bubble behavior,whose influence has not been focused *** a fixed current during normal electrolysis,hydrogen coalescence adjacent to cathode surface was invigorated at a lower *** analyses elucidated the hydrogen coalescence characteristics by quantifying size and population of detached hydrogen *** CCD increased about 104% within given range of conductivity(11.50-127.48 mS·cm^(-1))due to impaired bubble coalescence,which delays hydrogen film formation on the ***,decreasing trend of breakdown voltage was measured with increased conductivity showing maximum drop of 74%.It is concluded that onset of partial CGDE is directly affected by hydrodynamic bubble behaviors,whereas the electrolyte conductivity affects the bubble formation characteristics adjacent to cathode electrode.

关键词： Water electrolysis Critical current density Breakdown voltage Electrolyte conductivity Hydrogen bubble behavior

Distributional Methods for a Class of Functional Equations and Their Stabilities

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Acta Mathematica Sinica,English Series 2007年第11期23卷 2017-2026页

作者： Jae young chung Department of Mathematics Kunsan National UniversityKunsan 573-701South Korea

We consider a class of n-dimensional Pompeiu equations and that of Pexider equations and their Hyers Ulam stability problems in the spaces of Schwartz distributions. First, reducing the given distribution version of functional equations to differential equations we find their solutions. Secondly, using approximate identities we prove the Hyers Ulam stability of the equations.

关键词： Pompeiu equations Pexider equations distributions Hyers Ulam stability

Stability of a Generalized Quadratic Functional Equation in Schwartz Distributions

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Acta Mathematica Sinica,English Series 2009年第9期25卷 1459-1468页

作者： Jae-young chung Department of Mathematics Kunsan National University Kunsan 573-701 Republic of Korea

We consider the Hyers-Ulam stability problem of the generalized quadratic functional equationuoA＋voB-2woP1 - 2ko P2 =0, which is a distributional version of the classical generalized quadratic functional equation f（... 详细信息

关键词： Hyers-Ulam stability generalized quadratic functional equation distribution heat kernel

Dynamic observation of dendrite growth on lithium metal anode during battery charging/discharging cycles

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npj Computational Materials 2022年第1期8卷 960-972页

作者： hae Gon Lee Se young Kim Joon Sang Lee Next Generation Battery Research Center Korea Electrotechnology Research Institute(KERI)12Jeongiui-gilSeongsan-guChangwon-siGyeongsangnam-do51543Republic of Korea Department of Mechanical Engineering Yonsei University50 Yonsei-roSeodaemun-guSeoul03722Republic of Korea

Lithium metal is considered one of the most promising anode materials for application in next-generation ***,despite decades of research,practical application of lithium metal batteries has not yet been achieved because the fundamental interfacial mechanism of lithium dendrite growth is not yet fully *** this study,a series of reactive molecular dynamics (MD) simulations was performed to investigate the electrochemical dynamic reactions at the electrode/electrolyte *** allows quantitative characterization of morphological phenomena and real-time interfacial visualization of the dynamic growth of dead lithium and dendrites during repeated *** computational protocol was utilized to investigate the dendrite mitigation mechanism when an electrolyte additive (hydrogen fluoride) is dissolved in an organic ethylene carbonate (EC) electrolyte *** was confirmed that beneficial decomposition reactions between electrolyte components form a protective film on the anode surface,suppressing large interphase volume changes and unnecessary degradation reactions.

关键词： battery lithium electrolyte

Acoustic Nonlinearity of a Laser-Generated Surface Wave in a Plastically Deformed Aluminum Alloy

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Chinese Physics Letters 2012年第12期29卷 39-43页

作者： KIM chung-Seok JHANG Kyung-young Metallurgy and Materials Engineering Chosun UniversitySeosuk-dongGwangju501-759South Korea Mechanical Engineering Hanyang UniversityHangdang-dongSeongdong-guSeoul133-791South Korea

The acoustic nonlinearity of surface waves is studied to evaluate plastic deformation in aluminum alloys.A narrow-band surface wave is successfully generated by a pulsed Nd-YAG laser system consisting of a beam expander and a slit *** degrees of tensile deformation are induced by interrupting the tensile tests so as to obtain aluminum specimens with different degrees of plastic *** normalized acoustic nonlinearity increases as a function of tensile *** experimental results show that the acoustic nonlinearity of a laser-generated surface wave has a good correlation with the level of tensile deformation and has a potential to evaluate microdamage induced by dislocation microplasticity.

关键词： deformation nonlinearity Deform

Fatigue-Induced Micro-damage Characterization of Austenitic Stainless Steel 316 Using Innovative Nonlinear Acoustics

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Chinese Physics Letters 2012年第6期29卷 82-85页

作者： chung-Seok KIM Kyung-young JHANG Automotive Engineering Hanyang UniversityHangdang-dongSeongdong-guSeoul133-791South Korea Mechanical Engineering Hanyang UniversityHangdang-dongSeongdong-guSeoul133-791South Korea

We present innovative nonlinear acoustics for characterizing fatigue-induced micro-damage of austenitic stainless steel 316 subjected to high-cycle *** fatigue-driven deformations are accumulated at several positions near the middle of hourglass-shaped specimens.A bell-shaped curve of acoustic nonlinearity as a function of position is observed,and the variation in acoustic nonlinearity is attributed to the evolution of a lattice defect (dislocation) and stress-induced martensite based on transmission electron microscopy (TEM) *** oblique incidence technique using a longitudinal waveform is a potentially viable method for characterizing the high-cycle fatigue deformation of austenitic stainless steel 316 alloys.

关键词： fatigue steel martensite

Effect of nanoclay on properties of porous PVdF membranes

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Transactions of Nonferrous Metals Society of China 2011年第A1期21卷 141-147页

作者： hae.young HWANG Deuk-Ju KIM Hyung-Jun KIM young-Taik HONG Sang-Yong NAM School of Materials Science and Engineering Engineering Research Institute i-Cube Center Gyeongsang National University Fuel Cell Research Center Korea Institute of Science and Technology Seoul 136-791 Korea Energy Material Research Center Korea Research Institute of Chemical Technology Daejeon 305-600 Korea

The main requirements for battery separators are high porosity which can serve pathways of lithium ion and space for gel electrolytes to impregnate in a membrane and mechanical strength to allow easy handling for battery assembly. Generally, it appears the trade-off relationship between the porosity and mechanical strength of the membrane. PVdF composite membranes containing nano-size clays were used to improve the mechanical strength of the membrane without affecting the membrane porosity. The composite membranes were prepared by phase inversion method controlling the membrane preparation conditions such as retention time. The resultant membranes show increased mechanical properties with similar membrane porosity around 80 % compared to the pristine PVdF membrane. Incorporation of nonoclay can be considered as an effective method to improve the mechanica! strength in porous membrane supports, especially in a separator.

关键词： Li-ion battery separator poly(vinylidene fluoride) nanocomposite