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Influence of the wastewater composition on denitrification and biological P-removal in the S-DN-P process: (c) Dissolved and undissolved substrates

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Journal of Environmental Sciences 2009年第8期21卷 1074-1079页

作者： hee-jeong Choi Chul-Ho Choi Seung-Mok Lee Diwakar Tiwari Department of Environmental Engineering Kwandong University Department of Chemistry School of Physical Sciences Mizoram University

The denitdfication and P-removal in the sorption-denitrification-P-removal （S-DN-P） process were carded out under various wastewater compositions. It is noted that P-removal largely depends on the wastewater composition as well to the quantity of the substrates present in wastewater fraction. Three different wastewater fractions are obtained as： raw wastewater, dissolved wastewater （obtained with filtration using 0.45 μm filter）, and undissolved wastewater （i.e., infiltrate obtained by above filtration）. The ratio of P-release/CODtotal-consumption clearly inferred that undissolved wastewater possess very low value i.e., 0.0008 followed by raw wastewater 0.008 and dissolved wastewater 0.03. When this ratio was nearby 0.01, enhanced P-removal was observed. Moreover, the ratio of P-uptake to NO3^--N decomposition for raw wastewater was two times for dissolved wastewater. Interestingly, it was observed that the P-removal and denitrification depend not only on the dissolved substrates but also the undissolved substrates present in the wastewater. The result of the P-removal obtained with this S-DN-P process did not show a big difference of 36%, 34% and 30%, respectively, for raw, dissolved and undissolved wastewater.

关键词： denitrification polyhydroxybutyrate sequencing batch biofilm reactor sorption denitrification P-removals

2D spinel ZnCo_(2)O_(4) microsheet-coated functional separator for promoted redox kinetics and inhibited polysulfide dissolution

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Journal of Energy Chemistry 2021年第4期30卷 468-475页

作者： jeong seok Yeon Tae Ho Park Young Hun Ko Periyasamy Sivakumar Jun Su Kim Youngkywon Kim Ho seok Park School of Chemical Engineering Sungkyunkwan UniversitySuwon 16419Gyeonggi-doRepublic of Korea Advanced Batteries Research Center Korea Electronics Technology InstituteSeongnam 13509Gyeonggi-doRepublic of Korea Department of Health Sciences and Technology Samsung Advanced Institute for Health Sciences and Technology(SAIHST)Sungkyunkwan UniversitySuwon 16419Gyeonggi-doRepublic of Korea Department of Chemistry Dongguk University-Seoul CampusJung-gu 04620 SeoulRepublic of Korea

Lithium-sulfur(Li-S)batteries are receiving increasing attention as one of the potential next-generation batteries,owing to their high energy densities and low ***,practical Li-S batteries with high energy densities are extremely hindered by the sulfur loss,low Coulombic efficiency,and short cycling life originating from the polysulfide(LiPS)*** this study,two-dimensional(2D)ZnCo_(2)O_(4) microsheets fabricated by a facile hydrothermal process are employed to modify the separator,for improving the electrochemical performances of Li-S *** resulting 2D Zn Co_(2)O_(4)-coated separator features a coating thickness of approximately 10 lm,high ionic conductivity of 1.8 m S/cm,and low mass loading of 0.2 mg/cm^(2).This 2D ZnCo_(2)O_(4)-coated separator effectively inhibits Li PS shuttle by a strong chemical interaction with Li PS as well as promotes the redox kinetics by Zn CO2O4-coated layers,as determined by X-ray photoelectron spectroscopy analysis,self-discharge,time-dependent permeation test,Li symmetric cell test,and Li2S nucleation ***,the Li-S batteries based on the 2D Zn Co_(2)O_(4)-coated separator exhibit a high initial discharge capacity of 1292.2 m Ah/g at 0.1 ***,they exhibit excellent long cycle stability at 1 and 2 C with capacity retention of 84%and 86%even after800 cycles,corresponding to a capacity fading rate of 0.020%and 0.016%per cycle,***,these Li-S cells with a high sulfur loading at 5.3 mg/cm^(2) and low electrolyte concentration of 9 l L/mg deliver a high discharge capacity of 4.99 m Ah/cm^(2) after 200 cycles at 0.1 C.

关键词： Lithium sulfur batteries Functional separator 2D microsheet Polysulfide Redox kinetics

Effects of cryogenic temperature on tensile and impact properties in a medium-entropy VCoNi alloy

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Journal of Materials Science & Technology 2021年第31期90卷 159-167页

作者： Dae Cheol Yang Yong hee Jo Yuji Ikeda Fritz Kormann seok Su Sohn Department of Materials Science and Engineering Korea University02841 SeoulSouth Korea Metallic Materials Division Korea Institute of Materials Science51508 ChangwonSouth Korea Institute for Materials Science University of StuttgartPfaffenwaldring 5570569 StuttgartGermany Max-Planck-Institut für Eisenforschung Max-Planck-Straβe 140237 DüsseldorfGermany Department of Materials Science and Engineering Delft University of TechnologyMekelweg 22628 CD DelftThe Netherlands

Multi-principal element alloys usually exhibit outstanding strength and toughness at cryogenic temperatures,especially in CrMnFeCoNi and CrCoNi *** remarkable cryogenic properties are attributed to the occurrence of deformation twins,and it is envisaged that a reduced stacking fault energy(SFE)transforms the deformation mechanisms into advantageous properties at cryogenic temperatures.A recently reported high-strength VCoNi alloy is expected to exhibit further notable cryogenic ***,no attempt has been made to investigate the cryogenic properties in detail as well as the underlying deformation ***,the effects of cryogenic temperature on the tensile and impact properties are investigated,and the underlying mechanisms determining those properties are revealed in terms of the temperature dependence of the yield strength and deformation *** the strength and ductility were enhanced at 77 K compared to 298 K,while the Charpy impact toughness gradually decreased with *** planar dislocation glides remained unchanged at 77 K in contrast to the CrMnFeCoNi and CrCoNi alloys resulting in a relatively constant and slightly increasing SFE as the temperature decreased,which is confirmed via ab initio ***,the deformation localization near the grain boundaries at 298 K changed into a homogeneous distribution throughout the whole grains at 77 K,leading to a highly sustained strain hardening *** reduced impact toughness is directly related to the decreased plastic zone size,which is due to the reduced dislocation width and significant temperature dependence of the yield strength.

关键词： Medium-entropy alloy Cryogenic temperature Tensile property Charpy impact property Stacking fault energy

Effect of Al coating conditions on laser weldability of Al coated steel sheet

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中国有色金属学会会刊：英文版 2009年第4期19卷 946-951页

作者： Jung-Han LEE Jong-Do KIM Jin-seok OH Seo-jeong PARK Graduate School Korea Marine University Division of Marine Engineering System Korea Marine University Welding Research Center

Al coated steel sheets with excellent heat resistance,thermal reflection,and corrosion resistance are widely used in various *** laser weldability of the Al coated steel sheet for full penetration welding was *** phenomenon caused by intermixed aluminum and behavior of aluminum in the weld were *** coated steel sheets that have various thickness and coating mass were prepared for laser *** effects of parameters such as welding conditions and Al coating conditions were *** content mixed in the weld after laser welding was evaluated,and then a correlation between the mixed Al and mechanical properties was *** results show that the Al-rich zones which have Fe-Al intermetallic compounds are found in the *** intermetallic compounds cause the decreased strength of the weld.

关键词：铝合金焊接钢板焊接激光焊接 Al涂层金属间化合物涂层钢板涂层质量焊接条件

Let-7 miRNA and CDK4 siRNA co-encapsulated in Herceptin-conjugated liposome for breast cancer stem cells

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Asian Journal of Pharmaceutical Sciences 2020年第4期15卷 472-481页

作者： jeong Hyun Shin Dae Hwan Shin Jin seok Kim College of Pharmacy Sookmyung Women’s UniversitySeoul 04310Republic of Korea College of Pharmacy Chungbuk National UniversityCheongju 28160Republic of Korea

Recently,breast cancer stem cells(BCSCs)have rapidly emerged as a novel target for the therapy of breast cancer as they play critical roles in tumor growth,maintenance,metastasis,and ***-7 miRNA is known to be downregulated in a variety of cancers,especially BCSCs,whereas CDK4 being overexpressed in human epidermal growth factor receptor 2(HER-2)overexpressing tumor *** this study,let-7 miRNA and CDK4-specific siRNA were chosen as therapeutic agents and co-encapsulated in Herceptinconjugated cationic liposomes for breast cancer *** size,zeta potential,and encapsulation efficacy of mi/siRNA-loaded PEGylated liposome conjugated with Herceptin(Her-PEG-Lipo-mi/siRNA)were 176 nm,28.1 mV,and 99.7%±0.1%,*** cellular uptake(86%)was observed by fluorescence microscopy when SK-BR-3 cells were treated with Her-PEG-Lipo-mi/***,the increased amount of let-7a mRNA and decreased amount of cellular CDK4 mRNA were observed by qRT-PCR when SK-BR-3 cells were treated with Her-PEG-Lipo-mi/siRNA,which was even more so when SK-BR-3 stem cells were used(197 vs 768 times increase for let-7a,62%vs 68%decrease for CDK4).Growth inhibition(65%)andmigration arrest(0.5%)of the cellswere achieved by the treatment of the cells with Her-PEG-Lipo-mi/siRNA,but not withmi/siRNA complex or other *** conclusion,an efficient liposomal delivery system for the combination of miRNA and siRNA to target the BCSCs was developed and could be used as an efficacious therapeuticmodality for breast cancer.

关键词： Let-7 miRNA CDK4 siRNA Liposomes Breast cancer stem cells

Enhancing ammonia production rates from electrochemical nitrogen reduction by engineering three-phase boundary with phosphorus-activated Cu catalysts

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Journal of Energy Chemistry 2023年第9期84卷 394-401页

作者： Jeehye Kim Cho hee Lee Yong Hyun Moon Min hee Lee Eun Hyup Kim Sun hee Choi Youn jeong Jang Jae Sung Lee School of Energy and Chemical Engineering Ulsan National Institute of Science and Technology(UNIST)Ulsan 44919Republic of Korea Department of Chemical Engineering Hanyang UniversitySeoul 04763Republic of Korea Pohang Accelerator Laboratory(PAL) Pohang University of Science and Technology(POSTECH)Pohang 37673Republic of Korea

Electrochemical N_(2) reduction reaction(eNRR) over Cu-based catalysts suffers from an intrinsically low activity of Cu for activation of stable N_(2) molecules and the limited supply of N_(2) to the catalyst due to its low solubility in aqueous ***,we propose phosphorus-activated Cu electrocatalysts to generate electron-deficient Cu sites on the catalyst surface to promote the adsorption of N_(2) *** eNRR system is further modified using a gas diffusion electrode(GDE) coated with polytetrafluoroethylene(PTFE) to form an effective three-phase boundary of liquid water-gas N_(2)-solid catalyst to facilitate easy access of N_(2) to the catalytic *** a result,the new catalyst in the flow-type cell records a Faradaic efficiency of 13.15% and an NH_(3) production rate of 7.69 μg h^(-1) cm^(-2) at-0.2 V_(RHE),which represent 3.56 and 59.2 times increases from those obtained with a pristine Cu electrode in a typical electrolytic *** work represents a successful demonstration of dual modification strategies;catalyst modification and N_(2) supplying system engineering,and the results would provide a useful platform for further developments of electrocatalysts and reaction systems.

关键词： Electrochemical nitrogen reduction reaction Ammonia production Phosphorous modified copper electrodes Gas diffusion electrodes Three-phase boundary PTFE coating

A feasible route to produce 1.1 GPa ferritic-based low-Mn lightweight steels with ductility of 47%

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Journal of Materials Science & Technology 2022年第22期117卷 225-237页

作者： Kwang Kyu Ko Hyo Ju Bae Eun Hye Park Hyeon-Uk jeong Hyoung seok Park Jae seok jeong Jung Gi Kim Hyokyung Sung Nokeun Park Jae Bok Seol Department of Materials Engineering and Convergence Technology Center for K-metalGyeongsang National University(GNU)Jinju 52828South Korea School of Materials Science and Engineering Yeungnam UniversityGyeongbuk 38541South Korea Materials Research Team R&D Hyundai MobisYongin 16891South Korea Materials Technology Development Team Doosan Heavy Industries&ConstructionChangwon 51711South Korea

High- and medium-Mn (H/M-Mn) base lightweight steels are a class of ultrastrong structural materials with high ductility compared to their low-Mn counterparts with low strength and poor ***, producing these H/M-Mn materials requires the advanced or high-tech manufacturing techniques, which can unavoidably provoke labor and cost concerns. Herein, we have developed a facilestrategy that circumvents the strength–ductility trade-off in low-Mn ferritic lightweight steels, by employing low-temperature tempering-induced partitioning (LTP). This LTP treatment affords a typical Fe-2.8Mn-5.7Al-0.3C (wt.%) steel with a heterogeneous size-distribution of metastable austenite embeddedin a ferrite matrix for partitioning more carbon into smaller austenite grains than into the larger austenite ones. This size-dependent partitioning results in slip plane spacing modification and lattice strain,which act through dislocation engineering. We ascribe the simultaneous improvement in strength andtotal elongation to both the size-dependent dislocation movement in austenite grains and the controlleddeformation-induced martensitic transformation. The low-carbon-partitioned large austenite grains increase the strength and ductility as a consequence of the combined martensitic transformation andhigh dislocation density-induced hardening and by interface strengthening. Additionally, high-carbonpartitioned small austenite grains enhance the strength and ductility by planar dislocation glide (inthe low strain regime) and by cross-slipping and delayed martensitic transformation (in the high strainregime). The concept of size-dependent dislocation engineering may provide different pathways for developing a wide range of heterogeneous-structured low-Mn lightweight steels, suggesting that LTP maybe desirable for broad industrial applications at an economic cost.

关键词： Low-Mn lightweight steel Carbon partitioning Metastable austenite Dislocation movement

^(27)Al MAS-NMR study of inorganic polymer formation at ambient temperature

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Transactions of Nonferrous Metals Society of China 2011年第A1期21卷 182-187页

作者： Sang-Wook AHN hee-Soo LEE Wan-hee YANG Jung-Woo LEE Young-Keun jeong National Core Research Center for Hybrid Materials Solution Pusan National University School of Material Science and Engineering Pusan National University INTChem Co. Ltd.

Inorganic polymers are a novel class of materials formed by the polymerization of silicon, aluminium and oxygen species to form an amorphous three-dimensional framework structure. The basis of this process is the alkaline solutions to induce a certain amount of Si and AI atoms to dissolve from a feedstock such as aluminosilicate. A study of 27A1 MAS-NMR was carried out in an attempt to understand the reaction mechanism of the inorganic polymerization at ambient temperature. Scanning electron microscopy （SEM） and X-ray diflYactometry （XRD） were also employed to establish the composition and microstructure of the inorganic polymerization. Specimens were prepared with different A1/Si mole ratios from the starting materials. The higher the AI content, the more sufficient the AI atoms that can combine with SiO4, and the longer the reaction time, the more the bonded Si--O--A1--O polymer structure, and then the higher the A1 content, the fewer the octahedral A1 with a uniform Si--O--A1--O structure in four directions, because four AI atoms are combined with SiO4, resulting in a uniform Si--O--AI--O structure in four directions. The results show that they have an amorphous microstructure.

关键词： inorganic polymer amorphous tetrahedral

Electrochemical behavior of dental implant system before and after clinical use

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中国有色金属学会会刊：英文版 2009年第4期19卷 846-851页

作者： Chae-Heon CHUNG hee-Jung KIM Yong-Tae jeong Mee-Kyoung SON Yong-Hoon jeong Han-Cheol CHOE Department of Prosthodontics College of DentistryChosun University Department of Dental Materials & Research Center of Nano-Interface Activation for Biomaterials College of DentistryChosun University

Electrochemical behavior of dental implant system before and after clinical use(in vivo and in vitro) was researched by using abutment and titanium *** simulate an oral environment,the samples of clinically used and non-used implant systems as a working electrode were exposed to artificial saliva at(36.5±1) ℃.Electrochemical tests were carried out using a *** electrochemical test,the corrosion morphology of each sample was investigated by FE-SEM and *** corrosion potential and pitting potential of clinically used implant system are lower than those of non-used implant system,and clinically used implant system exhibits a lower range of passivation,indicating a less degree of inherent resistance against chloride *** polarization resistance decreases in the case of clinically used implant system,whereas,Rp for clinically non-used implant system increases compared with clinically used implant system.

关键词：电化学行为种植制度临床应用使用制度临床使用电化学测试夹具系统腐蚀形态