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Breakthrough scalable synthesis of anti-coking Cs-Ni/CeO_(x)-Al_(2)O_(3) nanocatalysts for optimal dry reforming performance

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Nano Research 2025年第2期18卷 913-929页

作者： Kyung Hee Oh Shin Wook Kang Jin Gyu Lee Jung-Il Yang Byung-Hyun Kim Chang Seop Hong Ji Chan Park Clean Fuel Research Laboratory Korea Institute of Energy ResearchDaejeon 34129Republic of Korea Department of Chemistry Korea UniversitySeoul 02841Republic of Korea Department of Chemical and Molecular Engineering Hanyang University ERICAAnsan 15588Republic of Korea Energy Engineering University of Science and TechnologyDaejeon 34113Republic of Korea

The dry reforming(DR)reaction is an eco-friendly process for producing synthesis gas(CO,H_(2))from greenhouse gases(CH_(4),CO_(2)).Despite advancements in various nickel(Ni)supported catalysts for this reaction,achieving high catalyst stability against carbon deposition and improving conversion rates remain significant *** this paper,we introduce a novel approach for synthesizing uniform Ni nanocatalysts with cesium(Cs)and cerium oxide(CeO_(x)).This synthesis is achieved using an automated device based on a co-melt infiltration *** method addresses the limitations of conventional catalyst synthesis,such as complex procedures,low reproducibility,and difficulties in scaling *** resulting catalysts contain uniformly small Ni particles,approximately 5 nm in size,with Cs and CeO_(x) evenly distributed throughout the alumina(Al_(2)O_(3))*** developed Ni/CeO_(x)-Al_(2)O_(3) and Cs Ni/CeOx-Al_(2)O_(3) nanocatalysts demonstrate improved conversion performance and stability under various DR *** improvement is attributed to the synergistic effect of Cs and CeO_(x),which creates a pathway to inhibit and remove carbon ***,these nanocatalysts exhibited superior resistance to carbon deposition compared to conventional Ni/Al_(2)O_(3) and commercial Ni catalysts under identical reaction conditions.

关键词： co-melt infitration nanocatalyst promoter dry reforming reaction coke resistance

Development of Air Vehicle with Active Flapping and Twisting of Wing

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Journal of Bionic Engineering 2011年第1期8卷 1-9页

作者： Sangyol Yoon Lac-Hyong Kang Sungho Jo Department of Computer science Korea Advanced Institute of Science and Technology Daejeon 305-701 Korea Department of Aerospace Engineering Korea Advanced Institute of Science and Technology Daejeon 305-701 Korea

This paper addresses mechanisms for active flapping and twisting of robotic wings and assesses flying effectiveness as a function of twist angle. Unlike the flapping motion of bird wings, insects generally make a twisting motion at the root of their wings while flapping, which makes it possible for them to hover in midair. This work includes the development of a Voice Coil Motor （VCM） because a flapping-wing air vehicle should be assembled with a compact actuator to decrease size and weight. A linkage mechanism is proposed to transform the linear motion of the VCM into the flapping and twisting motions of wings. The assembled flapping-wing air vehicle, whose weight is 2.86 g, produces an average positive vertical force proportional to the twist angle. The force saturates because the twist angle is mechanically limited. This work demonstrates the possibility of developing a flapping-wing air vehicle that can hover in midair using a mechanism that actively twists the roots of wings during flapping.

关键词： biomimetic flapping-wing air vehicle flapping twisting voice coil motor linkage mechanism

Current Status of the KSTAR Engineering

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Plasma science and Technology 2004年第1期6卷 2159-2165页

作者： J.S.Bak K.Kim C.H.Choi Y.K.Oh B.C.Kim N.I.Her H.L.Yang G.S.Lee the KSTAR Team korea Basic science institute 52 Yeoeun-Dong Yusung-Ku Daejeon 305-333 KoreaKorea Basic Science Institute 52 Yeoeun-Dong Yusung-Ku Daejeon 305-333 KoreaKorea Basic Science Institute 52 Yeoeun-Dong Yusung-Ku Daejeon 305-333 KoreaKorea Basic Science Institute 52 Yeoeun-Dong Yusung-Ku Daejeon 305-333 KoreaKorea Basic Science Institute 52 Yeoeun-Dong Yusung-Ku Daejeon 305-333 KoreaKorea Basic Science Institute 52 Yeoeun-Dong Yusung-Ku Daejeon 305-333 KoreaKorea Basic Science Institute 52 Yeoeun-Dong Yusung-Ku Daejeon 305-333 KoreaKorea Basic Science Institute 52 Yeoeun-Dong Yusung-Ku Daejeon 305-333 KoreaKorea Basic Science Institute 52 Yeoeun-Dong Yusung-Ku Daejeon 305-333 Korea

As there is substantial progress in the KSTAR tokamak engineering, all themajor structures and sub-systems are under fabrication and in procurement phase. The vacuum vessel,port, cryostat cylinder, lid, and bellows are being rigorously fabricated in the factory. The lowerpart of the KSTAR such as cryostat base and gravity support has been almost finished in itsfabrication. There are also great progresses and significant results in manufacturing of thesuperconducting magnet, including four Toroidal Field (TF) coils, lower and upper PF7 coils whichare the largest Poloidal Field (PF) coils. The TFOO coil, which has been made for test and back-upof the TF magnet system, was successfully tested in the cool-down and current charging. As thefabrications and procurements of major structures have been actively proceeded, assembly works werealso launched from Aug. 2003. More detailed description on these status, results, and plans will bedescribed in this paper.

关键词： KSTAR tokamak vacuum vessel magnet cryostat tokamak assembly

Electrophoretic Deposition of Oxide Nanoparticles for Electron Emission Enhancement

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Journal of Materials science & Technology 2010年第11期26卷 1032-1036页

作者： Jong Rok Ahn Gil Seon Kang Hwack Joo Lee Chang Joon Park korea Research institute of standards and science

Four oxide nanoparticles,such as yttrium oxide,lanthanum oxide,cerium oxide and zirconium oxide were coated on rhenium filaments by an electrophoretic deposition *** oxide coatings were examined by scanning electron microscopy,and electron emission characteristics of the oxide-coated rhenium were studied to find alternative oxide materials for replacing the hazardous thorium *** four oxides tested in this work,yttrium oxide and lanthanum oxide coated rhenium showed enhanced electron emission compared with an uncoated ***,lanthanum oxide coating evaporated too quickly in a vacuum chamber,and hence yttrium oxide was found to be the only alternative material for use in a routine mass *** optimum coating thickness of the yttrium oxide and lanthanum oxide was around 20 μm.

关键词： Electrophoretic deposition Oxide nanoparticles Scanning electron microscopy (SEM) Electron emission

Electrical resistivity evolution in electrodeposited Ru and Ru-Co nanowires

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Journal of Materials science & Technology 2022年第10期105卷 17-25页

作者： Jun Hwan Moon Seunghyun Kim Taesoon Kim Yoo Sang Jeon Yanghee Kim Jae-Pyoung Ahn Young Keun Kim Department of Materials science and Engineering Korea UniversitySeoul 02841Republic of Korea institute of Engineering Reserch Korea UniversitySeoul 02481Republic of Korea Advanced Analysis Center Korea Institute of Science and TechnologySeoul 02792Republic of Korea Research Resources Division Korea Institute of Science and TechnologySeoul 02792Republic of Korea

Nanoscale ruthenium(Ru)-based materials are promising replacements for existing multilayered Cu interconnects in integrated ***,it is not easy to apply the results of previously reported studies directly to the electrochemical damascene process because the previous studies have mainly focused on thin flms by dry ***,we report the electrical resistivity and microstructure of electrodeposited Ru *** estimate that the resistivity value of a 10 nm diameter Ru nanowire to be71.6μΩcm after analyzing the resistivity values of individual nanowires with various ***,we investigate the electrical properties of Ru_(x)Co_(1-x)nanowires where x is 0.04–0.99 at.%as possible replacements of the current Ta N barrier *** the entire composition range,the resistivity values of alloys are much lower than that of the conventional Ta ***,Ru and Ru-alloy nanowires surrounded by dielectric silica are thermally stable after 450°C heat ***,the nanoscale Ru and Ru-Co alloys possessing low resistivity values can be candidates for the interconnect and barrier materials,respectively.

关键词： Ruthenium(Ru) Ruthenium-cobalt(Ru-Co) Nanowire Electrical resistivity Microstructure Electrodeposition

High-throughput computational-experimental screening protocol for the discovery of bimetallic catalysts

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npj Computational Materials 2021年第1期7卷 1232-1241页

作者： Byung Chul Yeo Hyunji Nam Hyobin Nam Min-Cheol Kim Hong Woo Lee Sung-Chul Kim Sung Ok Won Donghun Kim Kwan-Young Lee Seung Yong Lee Sang Soo Han Computational science Research Center Korea Institute of Science and TechnologySeoulRepublic of Korea Department of Energy Resources Engineering Pukyong National UniversityBusanRepublic of Korea Materials Architecturing Research Center Korea Institute of Science and TechnologySeoulRepublic of Korea Department of Chemical and Biological Engineering Korea UniversitySeoulRepublic of Korea Department of Nanomaterials science and Engineering Korea University of Science and TechnologyDaejeonRepublic of Korea Advanced Analysis Center Korea Institute of Science and TechnologySeoulRepublic of Korea

To accelerate the discovery of materials through computations and experiments,a well-established protocol closely bridging these methods is *** introduce a high-throughput screening protocol for the discovery of bimetallic catalysts that replace palladium(Pd),where the similarities in the electronic density of states patterns were employed as a screening *** first-principles calculations,we screened 4350 bimetallic alloy structures and proposed eight candidates expected to have catalytic performance comparable to that of *** experiments demonstrate that four bimetallic catalysts indeed exhibit catalytic properties comparable to those of ***,we discover a bimetallic(Ni-Pt)catalyst that has not yet been reported for H_(2)O_(2) direct *** particular,Ni_(61)Pt_(39) outperforms the prototypical Pd catalyst for the chemical reaction and exhibits a 9.5-fold enhancement in cost-normalized *** protocol provides an opportunity for the catalyst discovery for the replacement or reduction in the use of the platinum-group metals.

关键词： synthesis catalyst bimetallic

Specific oceanographic characteristics and phytoplankton responses influencing the primary production around the Ulleung Basin area in spring

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Acta Oceanologica Sinica 2020年第2期39卷 107-122页

作者： Minji Lee Jin Ho Kim Yun-Bae Kim Chan Hong Park Kyoungsoon Shin Seung Ho Baek South Sea Research institute Korea Institute of Ocean Science and TechnologyGeoje 53201Korea Ulleungdo/Dokdo Ocean science Station Korea Institute of Ocean Science and TechnologyUlleungdo 40205Korea Dokdo Research Center East Sea Research InstituteKorea Institute of Ocean Science and TechnologyUljin 36315Korea

The East Sea(Sea of Japan)is a marginal,semi-closed sea in the northwestern *** Ulleung Basin area,which is located near the subpolar front of the East Sea,is known to have high primary production and good fisheries in spring *** episodic wind-driven events during the spring of 2017,horizontal and vertical profiles of physical chemical biological factors were investigated at 29 stations located in the Ulleung Basin *** addition,growth responses of phytoplankton communities to nutrient additions were evaluated by bioassay experiments to understand the fluctuation of phytoplankton *** of strong northwestern wind,phytoplankton biomass was scattered and upwelling phenomenon might be suppressed in this *** phytoplankton abundances in the coastal stations were significantly higher than offshore and island *** contrast,the nutrient and chlorophyll a(Chl a)concentrations and the phytoplankton biomass were quite low in all *** was dominated group(>75.1%for coastal,40.0%for offshore and 43.6%for island stations).In the algal bioassays,the phytoplankton production was stimulated by N *** in vivo Chl a values in the+N and+NP treatments were significantly higher than the values in the control and the+P *** on the field survey,the higher nutrients in coastal waters affected the growth of diatom assemblages,however,little prosperity of phytoplankton was observed in the offshore waters despite the injection of sufficient nutrients in bioassay *** growth of phytoplankton depended on the initial cell *** of results indicated that a dominant northwestern wind led to a limited nutrients condition at euphotic layers,and the low level of biomass supply from the coasts resulted in low primary *** supplying nutrients and introducing phytoplankton through the currents are critical to maintain the high productivity in the Ulleung Basin area of the East Sea.

关键词： Ulleung Basin Ulleungdo and Dokdo spring phytoplankton blooms episodic windstorm algal bioassays primary production

Angularity in Higgs boson decays via H→gg at NNLL' accuracy

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Chinese Physics C 2025年第02期 64-84页

作者：朱佳伟宋昱锦高俊 Daekyoung Kang Tanmay Maji Key Laboratory of Nuclear Physics and Ion-beam Application (MOE) and institute of Modern Physics Fudan University School of Physics and Astronomy Shanghai Key Laboratory for Particle Physics and Cosmologyand Key Laboratory for Particle Astrophysics and Cosmology (MOE)Shanghai Jiao Tong University Department of Physics Korea University Department of Physics National Institute of Technology

We present improved predictions of a class of event-shape distributions called angularity for a contribution from an effective operator H→gg in Higgs hadronic decay that suffers from large perturbative uncertainties. In the framework of the soft-collinear effective theory, logarithmic terms of the distribution are resummed at NNLL' accuracy, for which a two-loop constant of gluon-jet function for angularity is independently determined using a fit to the fixed-order distribution at the NLO corresponding to O（αs2） relative to the Born rate. Our determination has reasonable agreement with the value in a recently released thesis. In the fit, we use an asymptotic form with a fractional power conjectured from recoil corrections at one-loop order, and it improves the accuracy of determining positive values of the angularity parameter a. The resummed distribution is matched to the NLO fixed-order results to make our predictions valid at all angularity values. We also discuss the first and subtracted moments of angularity as a function of a that enable the extraction of information on leading and subleading nonperturbative corrections associated with gluons.

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Understanding secondary phase inclusion and composition variations in the microstructure design of n-type Bi_(2)Te_(3) alloys via selective dissolution of KCl

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Journal of Advanced Ceramics 2023年第12期12卷 2360-2370页

作者： Gwang Min Park Seunghyeok Lee Jun-Yun Kang Seung-Hyub Baek Heesuk Kim Jin-Sang Kim Seong Keun Kim KU-KIST Graduate School of Converging science and Technology Korea UniversitySeoul 02841Republic of Korea Electronic Materials Research Center Korea Institute of Science and TechnologySeoul 02792Republic of Korea Department of Materials science and Chemical Engineering Hanyang UniversityAnsan 15588Republic of Korea Ferrous Alloy Department Korea Institute of Materials ScienceChangwon 51508Republic of Korea Soft Hybrid Materials Research Center Korea Institute of Science and TechnologySeoul 02792Republic of Korea institute of Advanced Composite Materials Korea Institute of Science and TechnologyWanju 55324Republic of Korea

This study investigated the effects of KCl treatment on microstructure and thermoelectric properties of n-type Bi_(2)Te_(2.7)Se_(0.3)(BTS)thermoelectric *** innovative KCl treatment was originally intended to introduce nanopores through selective dissolution of KCl from a mixture of thermoelectric materials and ***,it unexpectedly induced substantial variations in material composition and microstructure during the subsequent spark plasma sintering(SPS)*** groups adsorbed on the powder surface during the dissolution resulted in the emergence of a Bi_(2)TeO_(5) secondary phase within the BTS matrix after the SPS process at 450℃.The concentration of Bi_(2)TeO_(5) increased with an increase in the KCl ***,a remarkable grain growth occurred at low KCl concentrations,likely due to the liquid-phase formation in a Te-rich composition during ***,excessive Bi_(2)TeO_(5) at higher KCl concentrations hindered grain *** variations in the microstructure had complex effects on electrical properties:The TeBi antisite defects increased the electron concentration,and Bi_(2)TeO_(5) reduced electron ***,the lattice thermal conductivity decreased due to the presence of Bi_(2)TeO_(5),from 0.8 W·m^(−1)·K^(−1) at 298 K for the pristine BTS to 0.6 W·m^(−1)·K^(−1) at 298 K for BTS treated with 1 wt%*** insights allowed precise adjustments of the electrical and thermal conductivities,leading to an enhancement in the maximum value of figure-of-merit(ZT)from 0.76 to 0.96 through the selective dissolution of KCl *** believe that our observations potentially enable advances in thermoelectric materials by engineering microstructures.

关键词： thermoelectric materials Bi_(2)Te_(3) Bi_(2)TeO_(5) grain growth n-type KCl