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Adsorption properties of polycarboxylate ether-based superplasticizer on cement particles and their resultant dispersion

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Frontiers of Structural and Civil Engineering 2022年第4期16卷 506-514页

作者： Jinyoung YOON Byoung Il CHOI jae Hong kim Department of Structural Engineering Research Korea Institute of Civil Engineering and Building Technology(KICT)Goyang 10223Republic of Korea System Safety Research Department Korea Shipbuilding and Offshore EngineeringSeongnam 13591Republic of Korea Department of Civil and Environmental Engineering Korea Advanced Institute of Science and TechnologyDaejeon 34141Republic of Korea

The cement dispersion performance of a polycarboxylate(PCE)-based superplasticizer is highly related to their adsorption behaviors as a function of *** study evaluated effects of PCEs on rheological properties of cementitious ***,characteristics of PCEs were characterized via permeation chromatography(GPC)and Fourier-transform infrared spectrometry(FT-IR).The adsorption behavior of single and blended PCEs on cementitious composites was identified using total organic carbon analyzer(TOC).Based on the measurement of PCE adsorption,the changes of rheological properties of cementitious materials as well as the number of dispersed cement particles were characterized using a rheometer and laser spectroscopy,*** experimental results support the systematic mechanism of PCE adsorption,cement dispersion,and the decrease in viscosity of cementitious materials.

关键词： adsorption polycarboxylate superplasticizer rheology dispersion

Superelastic metastable Ti-Mo-Sn alloys with high elastic admissible strain for potential bio-implant applications

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Journal of Materials Science & Technology 2023年第32期163卷 45-58页

作者： Shuanglei Li jae H.kim Seung Won Kang jae Ho kim Tae-Hyun Nam Jong-Taek Yeom Titanium Alloys Department Metal Materials DivisionKorea Institute of Materials Science(KIMS)Changwon 51508Republic of Korea Department of Materials Engineering and Convergence Technology&Research Institute for Green Energy Convergence Technology(RIGET) Gyeongsang National University900 GazwadongJinjuGyeongnam 52828Republic of Korea

The demand for titanium alloys simultaneously having high elastic admissible strain and large recovery strain for bio-implant applications is ***-free Ti-based shape memory alloys are promising candidates for obtaining the required multifunctional *** this study,a wide content range of(0-15)wt%of low-cost,toxicity-free,and high-biocompatible Sn element was added to the Ti-8Mo(wt%)alloy to study its effect on the superelastic recovery and mechanical properties of biomedical Ti-Mo-Sn *** tailoring Sn content,desired multifunctional properties of high elastic admissible strain and room temperature superelasticity were achieved in the studied Ti-Mo-Sn *** was found that the increase in Sn content stabilized theβphase and a singleβphase was obtained at room temperature in Ti-8Mo-(13,15)Sn *** addition of Sn modified the lattice parameters of theα″martensite andβphase and affected the lattice deformation stain ofβ→α″.The lattice deformation strain along the[011]βdirection was found to be decreased by-0.26%/wt%*** room temperature superelasticity with a recovery strain of 3.1%and an elastic admissible strain of 1%was obtained in the Ti-8Mo-13Sn *** Sn content increased to 15 wt%,a high elastic admissible strain of 1.56%and a recovery strain of 2.0%were *** Ti-Mo-Sn alloys with excellent multifunctional properties are promising candidates for bio-implant applications.

关键词： Ti-Mo-Sn alloy Shape memory alloy Elastic admissible strain Elastic modulus Superelasticity

Origin of superior low-cycle fatigue resistance of an interstitial metastable high-entropy alloy

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Journal of Materials Science & Technology 2022年第20期115卷 115-128页

作者： Seyed Amir Arsalan Shams jae Wung Bae jae Nam kim Hyoung Seop kim Taekyung Lee Chong Soo Lee Graduate Institute of Ferrous Technology Pohang University of Science and TechnologyPohang 37673Republic of Korea Department of Materials Science and Engineering Pohang University of Science and TechnologyPohang 37673Republic of Korea School of Mechanical Engineering Pusan National UniversityBusan 46241Republic of Korea

In this study, the deformation behaviors and related microstructural evolutions were investigated in either monotonic or cyclic deformation modes in an interstitial metastable high-entropy alloy. These investigations aimed to reveal the mechanisms underlying the superior low-cycle fatigue(LCF) life of this alloy.A thermomechanical process was applied to induce fine-grained(FG) and coarse-grained(CG) microstructures in Fe–30Mn–10Co–10Cr–0.4C(atomic percentage) alloy. Their superior combination of strength and ductility was attributed to the appearance of deformation-induced ε-martensite and the presence of carbon. The CG alloy showed a greater volume fraction of ε-martensite than the FG alloy in the monotonic deformation mode, and vice versa in the cyclic mode. Such a disparity was interpreted in light of the back-stress effect of the relaxed γ-grain boundaries in the latter mode. Meanwhile, the γ-to-ε phase transformation under cyclic loading at low strain amplitudes(0.4%) barely led to an improved fatigue life as compared with that at higher strain amplitudes(≥ 0.55%). The high reversibility of partial dislocation motions under cyclic loading and delaying the formation of dislocation cells through the martensitic transformation could explain why the alloys investigated in this study exhibited a superior LCF life compared with high-entropy alloys reported in previous studies.

关键词： High-entropy alloy Transformation-induced plasticity Monotonic deformation Cyclic deformation Low-cycle fatigue Stacking faults

Prothrombin kringle-2, a mediator of microglial activation: new insight in Alzheimer’s disease pathogenesis

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Neural Regeneration Research 2022年第12期17卷 2675-2676页

作者： jae Man Lee Sang Ryong kim Department of Biochemistry and Cell Biology Cell and Matrix Research InstituteSchool of MedicineKyungpook National UniversityDaeguKorea Brain Science and Engineering Institute Kyungpook National UniversityDaeguKorea School of Life Sciences BK21 FOUR KNU Creative BioResearch GroupInstitute of Life Science and BiotechnologyKyungpook National UniversityDaeguKorea

Microglial activation in Alzheimer’s disease(AD):In 1907,*** Alzheimer,a Bavarian-born German psychiatrist and neuropathologist,published an article describing the clinical and neuropathological features of an unclassified psychiatric *** disorder was later named AD and is currently the most common brain disorder(Takata et al.,2021).AD involves the accumulation of amyloid-β(Aβ)and hyperphosphorylated tau proteins in the brain,which are associated with senile plaques and neurofibrillary tangles,respectively(Vergara et al.,2019;Takata et al.,2021).AD is characterized by cognitive impairment and memory loss with hippocampal neurodegeneration(kim et al.,2021).

关键词： Alzheimer Aβ tau

Flash‑Induced High‑Throughput Porous Graphene via Synergistic Photo‑Effects for Electromagnetic Interference Shielding

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纳微快报:英文版 2023年第11期15卷 1-18页

作者： Jin Soo Lee Jeong‑Wook kim jae Hee Lee Yong Koo Son Young Bin kim Kyoohee Woo Chanhee Lee Il‑Doo kim jae Young Seok Jong Won Yu Jung Hwan Park Keon jae Lee Department of Materials Science and Engineering Korea Advanced Institute of Science and Technology(KAIST)291 Daehak‑roYuseong‑guDaejeon 34141Republic of Korea School of Electrical Engineering Korea Advanced Institute of Science and Technology(KAIST)291 Daehak‑roYuseong‑guDaejeon 34141Republic of Korea Department of Printed Electronics Nano‑Convergence Manufacturing Systems Research DivisionKorea Institute of Machinery and Materials(KIMM)156 Gajeongbuk‑RoYuseong‑GuDaejeon 34103Republic of Korea Department of Mechanical System Design Engineering Seoul National University of Science and Technology232 Gongneung‑roNowon‑guSeoul 01811Republic of Korea Department of Mechanical Engineering(Department of Aeronautics Mechanical and Electronic Convergence Engineering)Kumoh National Institute of Technology61 Daehak‑roGumiGyeongbuk 39177Republic of Korea

Porous 2D materials with high conductivity and large surface area have been proposed for potential electromagnetic interference(EMI)shielding materials in future mobility and wearable applications to prevent signal noise,transmission inaccuracy,system malfunction,and health ***,we report on the synthesis of lightweight and flexible flash-induced porous graphene(FPG)with excellent EMI shielding *** broad spectrum of pulsed flashlight induces photo-chemical and photo-thermal reactions in polyimide films,forming 5×10 cm^(2)-size porous graphene with a hollow pillar structure in a few *** resulting material demonstrated low density(0.0354 g cm^(−3))and outstanding absolute EMI shielding effectiveness of 1.12×10^(5) dB cm^(2) g^(−1).The FPG was characterized via thorough material analyses,and its mechanical durability and flexibility were confirmed by a bending cycle ***,the FPG was utilized in drone and wearable applications,showing effective EMI shielding performance for internal/external EMI in a drone radar system and reducing the specific absorption rate in the human body.

关键词： Porous graphene Flash lamp Photo-pyrolysis High-throughput Electromagnetic interference shielding

Multi-Stream CNN-Based Personal Recognition Method Using Surface Electromyogram for 5G Security

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Computers, Materials & Continua 2022年第8期72卷 2997-3007页

作者： Jin Su kim Min-Gu kim jae Myung kim Sung Bum Pan IT Research Institute Chosun UniversityGwangju61452Korea Interdisciplinary Program in IT-Bio Convergence System Chosun UniversityGwangju61452Korea

As fifth generation technology standard(5G)technology develops,the possibility of being exposed to the risk of cyber-attacks that exploits vulnerabilities in the 5G environment is *** existing personal recognitionmethod used for granting permission is a password-basedmethod,which causes security ***,personal recognition studies using bio-signals are being conducted as a method to access control to *** bio-signal,surface electromyogram(sEMG)can solve the existing personal recognition problem that was unable to the modification of registered information owing to the characteristic changes in its signal according to the performed ***,as an advantage,sEMG can be conveniently measured from arms and *** paper proposes a personal recognition method using sEMG,based on a multi-stream convolutional neural network(CNN).The proposed method decomposes sEMG signals into intrinsic mode functions(IMF)using empirical mode decomposition(EMD)and transforms each IMF into a *** recognition is performed by analyzing time–frequency features from the spectrogram transformed *** database(DB)adopted in this paper is the Ninapro DB,which is a benchmark EMG *** experimental results indicate that the personal recognition performance of the multi-stream CNN using the IMF spectrogram improved by 1.91%,compared with the singlestream CNN using the spectrogram of raw sEMG.

关键词： Personal recognition electromyogram signal multi-stream network empirical mode decomposition

Collagen fleece(Tachosil®)for treating testis torsion:A case report

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World Journal of Clinical Cases 2023年第18期11卷 4306-4312页

作者： Ki Min kim jae Heon kim Department of Urology Soonchunhayng University Seoul HospitalSeoul 04410South Korea

BACKGROUND Testicular torsion is an emergent disease in urology,and there has been discussion of the treatment of testicular *** decompression has been established as a critical treatment for testicular compartment syndrome(TCS),which occurs after detorsion in a patient who is diagnosed with testis *** now,testicular fasciotomy and incision of tunica albuginea with tunica vaginalis flap(TVF)graft have been suggested for decompression,and some studies about the efficacy of TVF were ***,this method is time consuming and needs meticulous technique,so other methods such as orchio-septopexy are *** objective of this clinical case report was to propose new surgical method using collagen fleece(Tachosil®)instead of tunica vagina *** SUMMARY A 5-year-old boy with scrotal pain visited our hospital 24 h after symptom *** history taking,physical examination,and scrotum ultrasonography,he was diagnosed with testis *** surgery was performed after *** the incision of scrotum and fasciotomy,we covered his tunica albuginea with collagen fleece called Tachosil®instead of covering with *** Short-term follow-up showed normal blood flow in testis without a *** is the first case report of using Tachosil®in testicular torsion surgery,and its advantages were already reported in other surgeries like Peyronie’s *** case suggests this new technique is an appropriate method because of its advantages including its cost-effective and time-saving *** main limitation is the short follow-up,so more studies are needed to provide a high level of evidence about its efficacy and safety.

关键词： Testicular torsion Testicular compartment syndrome Collagen fleece Tachosil® Case report

Upcycling end of lithium cobalt oxide batteries to electrocatalyst for oxygen reduction reaction in direct methanol fuel cell via sustainable approach

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Journal of Energy Chemistry 2023年第7期82卷 148-157,I0004页

作者： Keyru Serbara Bejigo Kousik Bhunia Jungho kim Chaehyeon Lee Seoin Back Sang-jae kim Nanomaterials&System Lab Major of Mechatronics EngineeringFaculty of Applied Energy SystemJeju National UniversityJeju 63243Republic of Korea Nanomaterials&System Lab Major of Mechanical System EngineeringCollege of EngineeringJeju National UniversityJeju 63243Republic of Korea Research Institute of New Energy Industry(RINEI) Jeju National UniversityJeju 63243Republic of Korea Department of Chemical and Biomolecular Engineering Institute of Emergent MaterialsSogang UniversitySeoul 04107Republic of Korea

Recycling spent lithium-ion batteries(SLIBs)has become essential to preserve the environment and reclaim vital resources for sustainable *** typical SLIBs recycling concentrated on separating valuable components had limitations,including high energy consumption and complicated separation *** work suggests a safe hydrometallurgical process to recover usable metallic cobalt from depleted LiCoO_(2)batteries by utilizing citric acid as leachant and hydrogen peroxide as an oxidizing agent,with ethanol as a selective precipitating *** anode graphite was also recovered and converted to graphene oxide(GO).The above components were directly resynthesized to cobaltintegrated nitrogen-doped graphene(Co@NG).The Co@NG showed a decent activity towards oxygen reduction reaction(ORR)with a half-wave potential of 0.880 V ***,almost similar to Pt/C(0.888 V ***)and with an onset potential of 0.92 V *** metal-nitrogen-carbon(Co-N-C)having the highest nitrogen content has decreased the barrier for ORR since the reaction was enhanced for Co@NG-800,as confirmed by density functional theory(DFT)*** Co@NG cathode catalyst coupled with commercial Pt-Ru/C as anode catalyst exhibits excellent performance for direct methanol fuel cell(DMFC)with a peak power density of 34.7 mW cm^(-2)at a discharge current density of120 m A cm^(-2)and decent stability,indicating the promising utilization of spent battery materials in DMFC ***,lithium was recovered from supernatant as lithium carbonate by coprecipitation *** work avoids sophisticated elemental separation by utilizing SLIBs for other renewable energy applications,lowering the environmental concerns associated with recycling.

关键词： Density functional theory(DFT) Direct methanol fuel cell Leaching Nitrogen doping Oxygen reduction reaction Recycling Spent lithium-ion batteries

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欧洲研究区跨区域协同创新治理举措及启示

科技管理研究 2024年第4期44卷 159-166页

作者：刘慧金·范德波特石家庄学院经济管理学院河北石家庄050035 布鲁塞尔自由大学法律与犯罪学学院布鲁塞尔1050

协同创新共同体建设遇到的最大困难是跨区域协同治理问题,可以说治理机制是否有效直接决定跨区域协同创新效果。建设欧洲研究区是欧盟促进其成员国间跨区域协同创新的重要举措,目标是整合成员国创新资源和力量以提升欧盟整体创新竞争力... 详细信息

协同创新共同体建设遇到的最大困难是跨区域协同治理问题,可以说治理机制是否有效直接决定跨区域协同创新效果。建设欧洲研究区是欧盟促进其成员国间跨区域协同创新的重要举措,目标是整合成员国创新资源和力量以提升欧盟整体创新竞争力。欧盟成员国创新能力不平衡,为实现各国有效跨区域协同治理,欧盟搭建了欧盟及其成员国和地区多层治理下的共同治理框架,通过设立欧洲研究区咨询建议机构、注重决策的民主化形成政策咨询建议机制,通过编制《欧洲研究区发展报告》《欧洲研究区发展路线图》和纳入“欧洲学期”构建监督机制,并开发基金工具、项目工具和各种对话机制等治理工具,在成员国间建立创新伙伴关系,推进各国创新资源、项目和政策的协同,提升欧盟治理能力、改善欧盟创新系统失灵问题。欧洲研究区加强创新能力发展不平衡地区间协同创新治理方面的经验对中国跨区域协同创新共同体建设,在加强不同层级主体共同治理、形成有效咨询建议机制、设计多种互补治理工具等方面带来有益启示。

关键词：欧洲研究区创新治理创新系统咨询建议机制监督机制治理工具协同创新创新共同体