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Prominent cycling reversibility and kinetics enabled by CaTiO3 protective layer on Zn metal for aqueous Zn-ion batteries

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Journal of Energy Chemistry 2025年第1期100卷 245-258页

作者： Gaeun lee Yong Nam Ahn Seongjoon So Chanwoo Park Jong-Seong Bae taehyun Park Il tae Kim Jaehyun Hur School of Chemical Biological and Battery Engineering Gachon University Seongnam Busan Center Korea Basic Science Institute

Aqueous Zn-ion batteries （AZIBs） have received considerable attention owing to their various advantages such as safety,low cost,simple battery assembly conditions,and high ionic ***,they still suffer from serious problems,including uncontrollable dendrite growth,corrosion,hydrogen evolution reaction （HER） from water decomposition,electrode passivation,and unexpected *** creation of a uniform artificial nanocrystal layer on the Zn anode surface is a promising strategy for resolving these ***,we propose the use of a perovskite CaTiO3（CTO） protective layer on Zn（CTO@Zn） as a promising approach for improving the performance of *** CTO artificial layer provides an efficient pathway for Zn ion diffusion towards the Zn metal because of the high dielectric constant （εr=180） and ferroelectric characteristics that enable the alignment of dipole moments and redistribute the Zn2+ions in the CTO *** avoiding the direct contact of the Zn anode with the electrolyte solution,the uneven dendrite growth,corrosion,parasitic side reactions,and HER are mitigated,while CTO retains its mechanical and chemical robustness during ***,CTO@Zn demonstrates an improved lifespan in a symmetric cell configuration compared with bare ***@Zn shows steady overpotential （～68 m V） for 1500 h at 1 mA cm-2/0.5 mA h cm-2,excelling bare ***,when paired with the V2O5-C cathode,the CTO@Zn//V2O5-C full battery delivers 148.4 mA h g-1（based on the mass of the cathode） after 300 *** study provides new insights into Zn metal anodes and the development of high-performance AZIBs.

关键词： Artificial layer Dielectric constant Zn metal anode Zinc aqueous battery

Development of analysis model for geometric error in turning processes

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Journal of Central South University 2011年第3期18卷 711-717页

作者： lee Mun-jae lee choon-man Department of Mechanical Design and Manufacturing Engineering Changwon National University

A finite element model was established for analyzing the geometric errors in turning operations and a two-step analyzing process was proposed. In the first analyzing step, the cutting force and the cutting heat for the cutting conditions were obtained using the AdvantEdge. Also, the deformation of a workpiece was estimated in the second step using the ANSYS. The deformation was analyzed for a 150 mm-long workpiece at three different measuring points, such as 10, 70 and 130 mm from a reference point, and the amounts of the deformation were compared through experiments. /n the results of the comparison and analysis, the values obtained from these comparison and analysis represent similar tendencies. Also, it is verified that their geometric errors increase with the increase in temperature. In addition, regarding the factors that affect the deformation of a workpiecc, it can be seen that the geometric error in the lathe is about 15%, the error caused by the cutting force is about 10%, and the deformation caused by the heat is about 75%.

关键词： geometric error machining accuracy finite element analysis turning cutting force, cutting temperature

Development of a one-axis manipulator for laser-assisted machining

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Journal of Central South University 2013年第2期20卷 378-384页

作者： KIM Dong-hyeon lee choon-man Department of Mechanical Design & Manufacturing Engineering Changwon National University

Laser-assisted machining has been considered as a new alternative machining method of difficult-to-cut materials. A laser module with one-axis manipulator is developed to focus on preheating laser beam effectively. First of all, the thermal characteristic analysis was performed to verify the importance of laser module location. Laser module should be moved within 1 mm. Analysis conditions of three positions in driving range of the one-axis manipulator are selected. And a C coupling is used as a connection device for spindle and laser module. An initial model has one C coupling, and the number of C coupling has been increased from 1 to 2 in an improved model. And the analysis is carried out again for the one-axis manipulator. The results of the static analysis, the maximum displacement and the maximum stress are decreased by 22% and 11%, respectively, for the improved model when the laser module is located at farthest away from the spindle unit. As a result of the modal analysis, the first natural frequency mode is increased by 13%, 18% and 12% at these positions of the improved model, respectively. The harmonic analysis of the improved model was performed by analyzing the results of the modal analysis. The maximum deformation was 0.33 mm in driving unit at 222 Hz. And the maximum compliance of the ISO axis direction was 0.23 mm/N. Finally, the one-axis manipulator has been fabricated successfully using the analysis result.

关键词： finite element analysis (FEA) laser-assisted machining manipulator

Development of two-axis control index table driven by direct drive motors

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Journal of Central South University 2011年第6期18卷 1962-1968页

作者： KIM Jae-hyun lee choon-man School of Mechatronics Changwon National University

The stability and reliability of a tilting index table should be considered at the design stage. A design method for the lightweight and improvement of the stability of the structure in a tilting index table was proposed using a commercial analysis program, ANSYS Workbench 12, by analyzing the static-thermal characteristics of the developed high-accuracy tilting index table at its design stage. The results of the performed structural analysis show that the maximum stress is generated at the stock tail part. An optimum design for the stock tail part was carried out to reduce the maximum stress and deformation. Also, the design variables were determined by considering the support of the stock tail part for the C-axis body. In the comparison of the results before and after the optimization, the maximum deformation and stress are improved by 2.8% and 8%, respectively.

关键词： tilting index table structural analysis modal analysis thermal analysis optimum design

Cloning,expression in Escherichia coli,and enzymatic properties of laccase from Aeromonas hydrophila WL-11

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Journal of Environmental Sciences 2010年第4期22卷 635-640页

作者： Jing Wu Kyoung-Sook Kim Jai-Heon lee Young-choon lee Department of Biotechnology Dong-A University Busan 604-714 South Korea. Brain Korea 21 Center for Silver-Bio Industrialization Dong-A University Busan 604-714 South Korea

A strain WL-11 with high laccase activity was isolated from activated sludge collected from the effluent treatment plant of a textile and dyeing industry. It was identified as Aeromonas hydrophila by physiological test and 16S rDNA sequence analysis. A gene encoding of laccase from a newly isolated Aeromonas hydrophila WL-11 was cloned and characterized. Nucleotide sequence analysis showed an open reading frame of 1605 bp encoding a polypeptide comprised of 534 amino acids. The primary structure of the enzyme predicted the structural features characteristic of other laccases, including the conserved regions of four histidine-rich copper-binding sites. The predicted amino acid sequence showed a high homology （more than 60%） with bacterial laccases in the genome and protein databases and the highest degree of similarity （61% identity） was observed with the multicopper oxidase of KlebsieUa sp. 601. When expressed in Escherichia coli, the recombinant enzyme was overproduced in the cytoplasm as soluble and active form. The purified enzyme had an optimum pH of 2.6 and 8.0 for ABTS （2,2＇-azino-bis（3-ethylbenzthiazolinesulfonic acid） and DMP （2,6-dimethoxyphenol）, respectively. The kinetic study on ABTS revealed a higher affinity of this enzyme to this substrate than DMP.

关键词： cloning expression enzymatic properties laccase Aeromonas hydrophila

Multi-stage optimum design of magazine type automatic tool changer arm

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Journal of Central South University 2012年第1期19卷 174-178页

作者： KIM Jae-Hyun lee choon-Man School of Mechatronics Changwon National UniversityChangwon 641-773Korea

To enhance machining efficiency,tool change time has to be ***,for an automatic tool changer attached to a machining center,the tool change time is to be *** the automatic tool changer is a main part of the machining center as a driving *** static attributes of the automatic tool changer using the commercial code,ANSYS Workbench V12,were tried to *** the optimum design of automatic tool changer arm was proposed by performing the multi-stage optimum *** shape optimization of the automatic tool changer was proposed and the result was verified to obtain acceptable *** is possible to obtain an optimized model in which the maximum deformation,maximum stress,and mass are reduced by 10.46%,12.89% and 9.26%,respectively,compared with those of the initial ***,the results between conventional method by the design of experiments and proposed method by the multi-stage optimum design method were compared.

关键词： automatic tool changer optimum design structural analysis exchange arm

Effects of automatic variable preload device on performance of spindle

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Journal of Central South University 2012年第1期19卷 150-154页

作者： KIM Dong-Hyeon lee choon-Man Department of Mechanical Design and Manufacturing Engineering Changwon National UniversityChangwon 641-773Korea

To increase the machine accuracy by improving the stiffness of bearings,a preload was applied to bearings.A variable preload technology was necessary to perform machining processes in both low and high speed *** automatic variable preload device was fabricated using an eccentric *** installing the fabricated device on a spindle,the effect of the automatic variable preload device on the performance of the spindle was *** the results of the vibration measurement of the spindle,the vibration is increased by 20%-37% according to measurement points at the maximum rotation speed of 5 000 r/***,in the results of the noise measurement of the spindle,the spindle rotation speed is increased by about 1.9% and 1.5% at the front and side of the spindle,*** on the results of this analysis,an improved method that reduces such effects on the performance of the spindle is proposed.

关键词： machine tool spindle automatic variable preload device vibration noise

Investigating factors driving phytoplankton growth and grazing loss rates in waters around Peninsular Malaysia

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Journal of Oceanology and Limnology 2021年第1期39卷 148-159页

作者： Joon Hai LIM choon Weng lee Chui Wei BONG Laboratory of Microbial Ecology Institute of Biological SciencesUniversity of MalayaKuala Lumpur 50603Malaysia Institute of Ocean and Earth Sciences University of MalayaKuala Lumpur 50603Malaysia Institute for Advanced Studies University of MalayaKuala Lumpur 50603Malaysia

In tropical waters where temperatures are relatively stable,we investigated whether the relationship between phytoplankton growth and grazing loss rate across diff erent habitats around Peninsular Malaysia can be attributed to its eutrophication *** measured phytoplankton growth(μ)and grazing loss(g)rates in waters off Bachok Marine Research Station(BMRS),located northeast of Peninsular ***-a(chl-a)concentration ranged from 2.90 to 15.78μg/L and was dominated by nanoand micro-phytoplankton(>2μm in size).Using the Landry and Hassett dilution method,μat BMRS ranged from 1.02 to 1.58/d whereas g varied from 0.07 to 0.88/*** accounted for 35%of the primary production at BMRS.A systematic review of available data in waters around Peninsular Malaysia,revealed howμfl uctuated over a wide range(0.01–1.80/d)and correlated with chl a distribution(R 2=0.181,P<0.001).However,the relationship was only signifi cant at<9μg/L chl a for mesotrophic waters and<16μg/L chl a for eutrophic *** contrast,g ranged from 0.00 to 1.01/d,and correlated withμat all *** g/μslope ranged from 19%to 84%,and was generally similar for waters around Peninsular ***,all the g/μslopes had a positive y-intercept except for BMRS,and this seemed to suggest the availability of alternative prey supporting grazing at the other stations.

关键词： phytoplankton growth grazing loss grazing pressure Bachok Marine Research Station(BMRS)

Cutting force signal pattern recognition using hybrid neural network in end milling

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中国有色金属学会会刊：英文版 2009年第B9期19卷 209-214页

作者： Song-tae SEONG Ko-tae JO Young-Moon lee Research and Development Department Gyeongbuk Hybrid Technology Institute School of Mechanical Engineering Yeongnam University School of Mechanical Engineering Kyungpo ok National University

Under certain cutting conditions in end milling, the signs of cutting forces change from positive to negative during a revolution of the tool. The change of force direction causes the cutting dynamics to be unstable which results in chatter vibration. Therefore, cutting force signal monitoring and classification are needed to determine the optimal cutting conditions and to improve the efficiency of cut. Artificial neural networks are powerful tools for solving highly complex and nonlinear problems. It can be divided into supervised and unsupervised learning machines based on the availability of a teacher. Hybrid neural network was introduced with both of functions of multilayer perceptron (MLP) trained with the back-propagation algorithm for monitoring and detecting abnormal state, and self organizing feature map (SOFM) for treating huge datum such as image processing and pattern recognition, for predicting and classifying cutting force signal patterns simultaneously. The validity of the results is verified with cutting experiments and simulation tests.

关键词：切削力信号混合神经网络模式识别铣床人工神经网络切削条件信号监测监督学习