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Seasonal dynamics of airborne biomolecules influence the size distribution of Arctic aerosols

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Environmental Science and Ecotechnology 2024年第6期22卷 245-255页

作者： Eunho Jang ki-tae park Young Jun Yoon Kyoung-Soon Jang Min Sung kim kitae kim Hyun Young Chung Mauro Mazzola David Cappelletti Bang Yong Lee Korea Polar Research Institute(KOPRI) Incheon21990Republic of Korea University of Science and Technology(UST) Daejeon34113Republic of Korea Department of Environmental Sciences and Biotechnology Hallym UniversityChuncheonGangwon-do24252Republic of Korea Korea Basic Science Institute(KBSI) Cheongju28119Republic of Korea National Research Council of Italy Institute of Polar Sciences(CNR-ISP)Via Gobetti 101Bologna40129Italy Department of Chemistry Biology and BiotechnologyUniversity of PerugiaVia Elce di Sotto 8Perugia06123Italy

Organic matter is crucial in aerosol-climate interactions,yet the physicochemical properties and origins of organic aerosols remain poorly *** we show the seasonal characteristics of submicron organic aerosols in Arctic Svalbard during spring and summer,emphasizing their connection to transport patterns and particle size ***-derived organic matter(MOM)and terrestrial-derived organic matter(TOM)accounted for over 90%of the total organic mass in Arctic aerosols during these seasons,comprising carbohydrate/protein-like and lignin/tannin-like compounds,*** spring,aerosols showed high TOM and low MOM intensities due to biomass-burning influx in the central *** contrast,summer exhibited elevated MOM intensity,attributed to the shift in predominant atmospheric transport from the central Arctic to the biologically active Greenland *** and TOM were associated with Aitken mode particles(100 nm diameter),*** association is linked to the molecular size of biomolecules,impacting the number concentrations of corresponding aerosol *** findings highlight the importance of considering seasonal atmospheric transport patterns and organic source-dependent particle size distributions in assessing aerosol properties in the changing Arctic.

关键词： Organic aerosol FT-ICR MS Particle size distribution Atmospheric transport pattern Biomolecule

Experimental Study on the Mechanical Properties of FRP Bars by Hybridizing with Steel Wires

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Engineering（科研） 2014年第7期6卷 365-373页

作者： Ji-Hyun Hwang Dong-Woo Seo ki-tae park Young-Jun You Structural Engineering Research Division Korea Institute of Construction Technology Goyang Korea

Many studies on fiber reinforced polymer composite bars, as a substitute for reinforcing bars, have been conducted to solve corrosion of steel in reinforced concrete structures since 1960s’. However, FRP Bars have a lower elastic modulus than steel rebar as a structural component of concrete structures. Material properties with brittleness fracture and low elastic modulus can be improved by combining cheaper steel than carbon or aramid fibers. In this study, prototypes of FRP Bars with inserted steel wires (i.e., “FRP Hybrid Bars”) were developed and their tensile performance was compared depending on the proportion and diameter of steel. The FRP Hybrid Bars were made by dividing them into D13 and D16 according to the diameter and proportion of inserted wires: GFRPs were combined with wires having different diameters of 0.5 mm, 1.0 mm, and 2.0 mm in the proportion of 10%, 30%, 50%, and 70%, respectively. As a result of tensile tests, the elastic modulus of FRP Hybrid Bars were improved as 20% - 190% in comparison with the fully GFRP Bars.

关键词： Fiber-Reinforced Polymer (FRP) FRP Hybrid Bar Tensile Test Steel Wire

Enhancement in Elastic Modulus of GFRP Bars by Material Hybridization

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Engineering（科研） 2013年第11期5卷 865-869页

作者： Dong-Woo Seo ki-tae park Young-Jun You Hyeong-Yeol kim Structural Engineering Research Division Korea Institute of Construction Technology Goyang Republic of Korea

Fiber reinforced polymer (FRP) reinforcing bars for concrete structure has been extensively investigated for last two decades and a number of FRP bars are commercially available. However, one of shortcomings of the existing FRP bars is its low elastic modulus, if glass fibers are used (i.e., GFRP). The main objective of this study using the concept of material hybridization is to develop a viable hybrid FRP bar for concrete structures, especially for marine and port con- crete structures. The purposes of hybridization are to increase the elastic modulus of GFRP bar with acceptable tensile strength. Two types of hybrid GFRP bar were considered in the development: GFRP crust with steel core and GFRP bar with steel wires dispersed over the cross-section. Using E-glass fibers and unsaturated polyester resins, the hybrid GFRP bar samples of 13 mm in diameter were pultruded and tested for tensile properties. The effect of hybridization on tensile properties of GFRP bars was evaluated by comparing the results of tensile test with those of non-hybrid GFRP bars. The results of this study indicated that the elastic modulus of the hybrid GFRP bar was increased by up to 270 percent by the material hybridization. The results of the test and the future recommendations are summarized in this paper. To ensure long-term durability of the hybrid GFRP bars in waterfront structure applications, the individual and combined effects of environmental conditions on hybrid GFRP rebar itself as well as on the interface between rebar and concrete should be accessed.

关键词： FRP Glass Fibers Tensile Test Elastic Modulus Pultrusion Material Hybridization Marine Structures

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

Aging Analysis Framework of Windows-Based Systems through Differential-Analysis of System Snapshots

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Computers, Materials & Continua 2022年第12期73卷 5091-5102页

作者： Eun-tae Jang Sung Hoon Baek ki-Woong park SysCore Lab Sejong UniversitySeoul05006Korea Department of Computer System Engineering Jungwon UniversityChungcheongbuk-do28024Korea

When aWindows-based system is used for an exceedingly long time,its performance degrades,and the error occurrence rate tends to *** is generally called system *** investigate the reasons for system aging,various studies have been conducted within the range of the operating system kernel to the user ***,finding an accurate reason for system performance degradation remains challenging research *** this study,system monitoring was conducted by dividing a system into‘before software installation,’‘after software installation,’and‘after software removal.’We confirmed that when a software installed in a system is removed,various system elements,such as storage and memory,are not restored to the level prior to the software ***,we established a hypothesis regarding the performance degradation of a computer system owing to repeated software installation/removal operations,investigated the correlation between system aging and repeated software installation/removal operations,and proposed a system aging analysis framework for analyzing the reason behind system *** the proposed system aging analysis framework,we aim to forcibly age a Windows-based system by repeating the software installation/removal operation by utilizing the system forced aging *** framework identifies the elements affecting system performance through a differential data analysis of the system time-series data extracted by the system performance extraction and system component snapshot ***,the aging analysis framework presented in this study is expected to be effectively utilized as an index for studying system aging.

关键词： System aging virtual machine system analysis

Effects of humic acid on phytodegradation of petroleum hydrocarbons in soil simultaneously contaminated with heavy metals

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Journal of Environmental Sciences 2011年第12期23卷 2034-2041页

作者： Soyoung park ki Seob kim Jeong-tae kim Daeseok Kang kijune Sung Department of Ocean Engineering Pukyong National University Busan 608-737 Korea Department of Ecological Engineering Pukyong National University Busan 608-737 Korea

The use of humic acid （HA） to enhance the efficiency of phytodegradation of petroleum hydrocarbons in soil contaminated with diesel fuel was evaluated in this study. A sample of soil was artificially contaminated with commercially available diesel fuel to an initial total petroleum hydrocarbons （TPH） concentration of 2300 mg/kg and four heavy metals with concentrations of 400 mg/kg for Pb, 200 mg/kg for Cu, 12 mg/kg for Cd, and 160 mg/kg for Ni. Three plant species, Brassica campestris, Festuca arundinacea, and Helianthus annuus, were selected for the phytodegradation experiment. Percentage degradation of TPH in the soil in a control pot supplemented with HA increased to 45% from 30% without HA. The addition of HA resulted in an increases in the removal of TPH from the soil in pots planted with B. campestris, F. arundinacea, and H. annuus, enhancing percentage degradation to 86%, 64%, and 85% from 45%, 54%, and 66%, respectively. The effect of HA was also observed in the degradation of n-alkanes within 30 days. The rates of removal of n-alkanes in soil planted with B. campestris and H. annuus were high for n-alkanes in the range of C11–C28. A dynamic increase in dehydrogenase activity was observed during the last 15 days of a 30-day experimental period in all the pots amended with HA. The enhanced biodegradation performance for TPHs observed might be due to an increase in microbial activities and bioavailable TPH in soils caused by combined effects of plants and HA. The results suggested that HA could act as an enhancing agent for phytodegradation of petroleum hydrocarbons in soil contaminated with diesel fuel and heavy metals.

关键词： phytodegradation TPHs humic acid n-alkanes DHA combined effects

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New para-magnetic(CoFeNi)(50)(CrMo)(50-x)(CB)x(x=20,25,30)non-equiatomic high entropy metallic glasses with wide supercooled liquid region and excellent mechanical properties

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Journal of Materials Science & Technology 2020年第8期36卷 135-143页

作者： Jeong tae kim Sung Hwan Hong Jin Man park Jürgen Eckert ki Buem kim Erich Schmid Institute of Materials Science Austrian Academy of Sciences(ÖAW)Jahnstrae 128700LeobenAustria Hybrid Materials Center(HMC) Department of Nanotechnology and Advanced Materials EngineeringSejong University209Neungdong-roGwangjin-guSeoul143-747Republic of Korea Global Technology Center(GTC) Samsung Electronics Co.Ltd129 Samsung-roYeongtong-guSuwonsiGyeonggi-do443-742Republic of Korea Department of Materials Science Chair of Materials PhysicsMontanuniversität LeobenJahnstraße 128700LeobenAustria

In this study,high entropy metallic glasses(HEMGs)were developed through a combination of concepts for designing metallic glasses(main element+transition metal+metalloid element)and high-entropy alloys(more than five elements,each element having an atomic concentration between 5 at.%and 35 at.%).The developed metallic glass alloys are composed of Co-Fe-Ni main elements,transition metals(Cr,Mo)and metalloid elements(C,B).Moreover,the present work reports the thermal,mechanical and magnetic properties of(CoFeNi)(50)(CrMo)(50-x)(CB)x alloys with x=20,25,*** developed as-spun HEMGs exhibit typical paramagnetic properties even for a high amount of ferromagnetic elements(Co,Fe,and Ni)and have high elastic modulus(103–160 GPa)and hardness(14–27 GPa),thus possessing mechanical properties similar to well-known Co-based metallic glasses(Co-Cr-Mo-C-B system).In addition,some of the bulk samples prepared with a diameter of 2 mm form bulk metallic glasses with a high compressive strength around 3.5 *** mechanisms determining the stability of the supercooled liquid,as well as the paramagnetic and mechanical properties for the developed non-equiatomic HEMGs,are discussed.

关键词： Metallic glasses Paramagnetism High entropy alloys Phase stability

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Density functional theory study on the role of ternary alloying elements in TiFe-based hydrogen storage alloys

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Journal of Materials Science & Technology 2021年第33期92卷 148-158页

作者： Won-Seok Ko ki Beom park Hyung-ki park School of Materials Science and Engineering University of UlsanUlsan 44610Republic of Korea Functional Materials and Components R&D Group Korea Institute of Industrial TechnologyGangneung 25440Republic of Korea

The role of additional ternary alloying elements on the performance of stationary TiFe-based hydrogen storage alloys was investigated based on first-principles density functional theory *** a basic step for examinations,the site preference of each alloying element in the stoichiometric and nonstoichiometric B2TiFe compounds was clarified considering possible antisite *** on the revealed site preference,the effect of various possible ternary elements on the hydrogen storage was examined by focusing on the formation enthalpies of TiFeH and TiFeH_(2) hydrides,which were closely related to the change in the location of plateaus in the pressure-composition-temperature *** physical properties such as the volume expansion due to hydride formation were also examined to provide additional criteria for selecting optimum alloying conditions in future alloying design *** alloying elements that maximize the grain boundary embrittlement due to the solute segregation were proposed for the enhanced initial activation of TiFe-based hydrogen storage alloys.

关键词： Hydrogen storage alloy Titanium-iron Density functional theory calculation Metallic hydride

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Growth and Magnetic Properties of Sol-Gel Derived Co-Doped ZnO Thin Film

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Journal of Rare Earths 2006年第Z1期24卷 59-63页

作者： Young Sung kim ki Chul kim Won Pil tae Dae Ho Yoon tae Seok park Su Jeong Suh Advanced Material Process of Information Technology Sungkyunkwan University Suwon 440-746 Korea Cambridge-ETRI Joint R&D Centre Electronics and Telecommunications Research Institute Daejeon 305-350 Korea Ulsan Industry Promotion Techno Park Ulsan 683-804 Korea Advanced Material Process of Information Technology Sungkyunkwan University Suwon 440-746 Korea Advanced Material Process of Information Technology Sungkyunkwan University Suwon 440-746 Korea Advanced Material Process of Information Technology Sungkyunkwan University Suwon 440-746 Korea

Zn1-xCoxO films were grown on glass by sol-gel spin coating process. A homogeneous and stable Zn1-xCoxO sol was prepared by dissolving zinc acetate dihydrate, cobalt acetate tetrahydrate and aluminium chloride hexahydrate as solutes in solution of isopropanol and monoethanolamine. The films were postheated and vacuum annealed, and investigated for c-axis preferred orientation and electromagnetic properties. Zn1-xCoxO films with different Co concentrations were oriented well along the c-axis, especially the Zn1-xCoxO film with 10% Co(atom fraction) was highly c-axis oriented. The transmittance spectra show that Zn1-xCoxO films occur d-d transition and sp-d exchange interaction between Co2+ ions. The electrical resistivity of the films at 10% Co had the lowest value because the crystallite size became largest and the crystallinity of the c-axis was improved. X-ray photoelectron spectroscopy and alternating gradient magnetometer analyses indicated that no Co metal cluster was formed, and the ferromagnetism at room temperature appeared. The characteristics of the electrical resistivity and room temperature ferromagnetism of sol-gel derived Zn1-xCoxO films suggest a potential application of dilute magnetic semiconductor devices.

关键词： sol-gel Zn1-xCoxO thin film dilute magnetic semiconductor (DMS)