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Deposition of Nano-Scaled Coatings Using Inductively Coupled Plasma

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Journal of Rare Earths 2004年第Z2期22卷 153-156页

作者： D H jung B park J J Lee School of Materials Science and Engineering College of EngineeringSeoul National UniversitySeoul 151-744Korea School of Materials Science and EngineeringCollege of EngineeringSeoul National UniversitySeoul 151-744Korea School of Materials Science and EngineeringCollege of EngineeringSeoul National UniversitySeoul 151-744Korea

Nano-scaled Ti-B-N coatings could be produced by inductively coupled plasma (ICP) assisted magnetron spurtering. The properties and microstructure of the coating can be changed drastically by applying ICP to conventional magnetron sputtering. In this work, an internal type rf ICP process is used. The core of this technology is the efficient production and control of self-depositing ions and reactive gas ions by an induced electric field. Ti-B-N coatings were prepared by using a TiB2 target and a gas mixture of N2 and Ar at 200 ℃ and a pressure of 60 mTorr. In addition to ICP, the effect of the substrate bias voltage on the structure and properties of the coating was investigated. By applying ICP and a bias voltage to the substrate the hardness of the Ti-B-N coating is increased by more than 75 GPa, as a result of enhanced ionization in the plasma. The Ti-B-N coating, which has the highest hardness, shows the best surface uniformity and a very dense structure with a grain size of 3 nm. This sample also shows a high crystallinity compared to the coating prepared using other deposition parameters.

关键词： nano-scaled coatings industively conpled plasma

Porous FeS nanofibers with numerous nanovoids obtained by Kirkendall diffusion effect for use as anode materials for sodium-ion batteries

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Nano Research 2017年第3期10卷 897-907页

作者： jung Sang Cho Jin-Sung park Yun Chan Kang Department of Materials Science and Engineering Korea University Anam-Dong Seongbuk-Gu Seou1136-713 Republic of Korea Department of Engineering Chemistry Chungbuk National University Chungbuk 361-763 Republic of Korea

Porous FeS nanofibers with numerous nanovoids for use as anode materials for sodium-ion batteries were prepared by electrospinning and subsequent sulfidation. The post-treatment of the as-spun Fe（acac）3-polyacrylonitrile composite nanofibers in an air atmosphere yielded hollow Fe2O3 nanofibers due to Ostwald ripening. The ultrafine Fe2O3 nanocrystals formed at the center of the fiber diffused toward the outside of the fiber via Ostwald ripening. On sulfidation, the Fe2O3 hollow nanofibers were transformed into porous FeS nanofibers, which contained numerous nanovoids. The formation of porosity in the FeS nanofibers was driven by nanoscale Kirkendall diffusion. The porous FeS nanofibers were very structurally stable and had superior sodium-ion storage properties compared with the hollow Fe2O3 nanofibers. The discharge capacities of the porous FeS nanofibers for the Ist and 150th cycles at a current density of 500 mA.g-1 were 561 and 592 mA.h-g-1, respectively. The FeS nanofibers had final discharge capacities of 456, 437, 413, 394, 380, and 353 mA-h.g-1 at current densities of 0.2, 0.5, 1.0, 2.0, 3.0, and 5.0 A.g-1, respectively.

关键词： iron sulfide sodium-ion batteries Kirkendall effect nanofibers electrospinning

Strategy for Creating AR Applications in Static and Dynamic Environments Using SLAM-and Marker Detector-Based Tracking

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Computer Modeling in Engineering & Sciences 2022年第4期131卷 529-549页

作者： Chanho park Hyunwoo Cho Sangheon park Sung-Uk jung Suwon Lee Electronics and Telecommunications Research Institute Daejeon34129Korea Graduate School of Engineering The University of TokyoTokyo113-0033Japan School of Computer Science and The Research Institute of Natural Science Gyeongsang National UniversityJinju-si52828Korea

Recently,simultaneous localization and mapping(SLAM)has received considerable attention in augmented reality(AR)libraries and *** the assumption of scene rigidity is common in most visual SLAMs,this assumption limits the possibilities of AR applications in various real-world *** this paper,we propose a new tracking system that integrates SLAMwith amarker detection module for real-time AR applications in static and dynamic *** the proposed system assumes that the marker is movable,SLAM performs tracking andmappingof the static scene except for themarker,andthemarker detector estimates the 3-dimensional pose of the marker attached to the dynamic *** can place SLAM maps,cameras,and dynamic objects(markers)on the same coordinate system,and we can also accurately augment AR resources in real-time on both the static scene and dynamic objects ***,having a static map of the scene in advance has the advantage of being able to performtracking of static and dynamic environments with mapping *** this paper,we evaluate whether the proposed tracking systemis suitable for AR applications and describe a strategy for creating AR applications in static and dynamic environments with a demonstration.

关键词： Augmented reality SLAM marker tracking coordinate system

Fabrication and characterization of Ag flake hybrid circuits with IPL-sintering

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Journal of Materials Science & Technology 2020年第18期52卷 13-18页

作者： Choong-Jae Lee Kwang-Ho jung Kyung Deuk min Bum-Geun park Seung-Boo jung School of Advanced Materials Science Engineering Sungkyunkwan University2066 Seobu-roJangan-guSuwon-si16419Republic of Korea Visual Display Business Samsung Electronics Co.Ltd.129Samsung-roYeongtong-guSuwon-si16677Republic of Korea

The study of photonic sintering has gained interest based on the advantages of fast processing at room ***,printed electronics made from photonic sintering with an intensive pulsed light(IPL)energy source exhibit more mechanical instability than those made from conventional thermal sintering *** solve the mechanical instability problems,we fabricated Ag flake hybrid pastes with a variety of concentrations of Ag flake(0,25,50,75,and 100 wt.%).All of the screen-printed hybrid Ag circuits were fabricated on polyimide substrates and were sintered at 3.5 *** porosity was analyzed using the Brunauer-Emmett-Teller *** IPC(Packaging Electronic Circuits)sliding test was performed to analyze the flexibility of the screen-printed Ag flake hybrid *** adhesion strength of the hybrid circuits was evaluated with a roll-type 90°peel *** hybrid Ag printed circuit showed improvements in both the flexibility and adhesion strength with the addition of Ag flake.

关键词： Low-temperature sintering Flexibility Flaky powders Adhesion strength Intensive pulsed light

Anticancer effects of oligomeric proanthocyanidins on human colorectal cancer cell line, SNU-C4

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World Journal of Gastroenterology 2005年第30期11卷 4674-4678页

作者： Youn-jung Kim Hae-Jeong park Seo-Hyun Yoon mi-Ja Kim Kang-Hyun Leem Joo-Ho Chung Hye-Kyung Kim Department of Dental Hygiene Department of Pharmacology Department of Obesity Management College of Oriental Medicine Department of Food and Biotechnology

AIM: Oligomeric proanthocyanidins (OPC), natural polyphenolic compounds found in plants, are known to have antioxidant and anti-cancer effects. We investigated whether the anti-cancer effects of the OPC are induced by apoptosis on human colorectal cancer cell line, ***: Colorectal cancer cell line, SNU-C4 was cultured in RPmi 1640 medium supplemented with 10% fetal bovine serum. The cytotoxic effect of OPC was assessed by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenylt-etrazolium bromide (MTT) assay. To find out the apoptotic cell death, 4, 6-diamidino-2-phenylindole (DAPI) staining,terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) assay, reverse transcriptionpolymerase chain reaction (RT-PCR), and caspase-3 enzyme assay were ***: In this study, cytotoxic effect of OPC on SNUC4 cells appeared in a dose-dependent manner. OPC treatment (100 μg/mL) revealed typical morphological apoptotic features. Additionally OPC treatment (100 μg/mL)increased level of BAX and CASPASE-3, and decreased level of BCL-2 mRNA expression. Caspase-3 enzyme activity was also significantly increased by treatment of OPC (100 μg/mL) compared with ***: These data indicate that OPC caused cell death by apoptosis through caspase pathways on human colorectal cancer cell line, SNU-C4.

关键词： Oligomeric pranthocyanidins Apoptosis Anticancer effects Colorectal cancer

Free radical scavenger effect of rebamipide in sperm processing and cryopreservation

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Asian Journal of Andrology 2003年第3期5卷 195-201页

作者： Nam Cheol park Hyun Jun park Kyeong mi Lee Dong Gil Shin Department of Urology College of Medicine Pusan National University Busan 602 739 KoreaDepartment of Urology College of Medicine Pusan National University Busan 602 739 KoreaDepartment of Urology College of Medicine Pusan National University Busan 602 739 KoreaDepartment of Urology College of Medicine Pusan National University Busan 602 739 Korea

Aim: To study the effect of rebamipide added to semen samples and cryoprotectant on reactive oxygen species (ROS) production. Methods: Semen samples from 30 fertile and healthy volunteers were collected by masturbation after 2 days - 3 days of abstinence. After liquefaction, the specimens were diluted with sperm wash media to a uniform density of 20×106/mL. Rebamipide was added to semen samples and cryoprotectant to a final concentration of 10 μmol/L, 30 μmol/L, 100 μmol/L or 300 μmol/L. Specimens were incubated at 37 ℃ in a 0.5 % CO2 incubator for 1 h or cryopreserved at -196 ℃ LN2 for 3 days. The sperm motility and viability and the levels of ROS and lipid peroxidation of sperm membrance were assessed before and after incubation and cryopreservation by means of computer assisted semen analyzer, eosin-nigrosin stain, chemiluminescence and thiobarbituric acid assay, respectively. Results: The sperm motility was significantly increased after incubation with 100 μmol/L and 300 μmol/L rebamipide (Pmipide than that with other concentrations. The sperm viability showed no significant difference before and after incubation (P>0.05). The levels of ROS and lipid peroxidation in semen were significantly decreased in proportion to the concentrations of rebamipide both after incubation and cryopreservation (Pmipide is an effective free radical scavenger in semen in vitro.

关键词： male infertility reactive oxygen species rebamipide

Environmental friendly synthesis of hierarchical mesoporous platinum nanoparticles templated by fucoidan biopolymer for enhanced hydrogen evolution reaction

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Journal of Materials Science & Technology 2020年第11期42卷 185-190页

作者： Seung Man Lim Kyunglee Kang Hongje Jang jung Tae park Department of Chemical Engineering Konkuk University120 Neungdong-roGwangjin-guSeoul 05029Republic of Korea Department of Chemistry Kwangwoon University20 Cwangwoon-roNowon-guSeoul 01897Republic of Korea

Researching novel hydrogen evolution reaction(HER)catalysts with enhanced electrocatalytic activity,excellent stability,and cost-efficiency is of great significance for the large-scale hydrogen production from industrial electrolysis *** report the preparation of hierarchical mesoporous-Pt nanoparticles(HM-Pt NPs)with coral-like rough surface morphologies using environmental friendly and biocompatible fucoidan(Fu)biopolymer as a surface engineering compound and its application to electrocatalysts for *** designed HM-Pt NPs yields better mass activity of electrocatalysts compared to a commercial Pt/***-Pt NPs showed an overpotential of 33 mV at 10 mA cm-2 for the HER in 0.5 MH2SO4,which was highly comparable to that of the commercial Pt/C catalysts(29 mV).However,the amount of HM-Pt NPs loaded in glassy carbon electrode(0.033 mg mL-1)was approximately 20 times lower than that of the commercial Pt/C(0.64 mg *** HM-Pt NPs also maintained high catalytic stability with a consistent HER current density after 1000 continuous *** excellent HER performance is attributed to the improved electrochemical surface area,highly porous structure,and good surface wettability of the HM-Pt NPs,which results in enhanced electrocatalytic activity,decreased resistance at the electrode/electrolyte interface,and facile penetration of the electrolytes inside the electrode.

关键词： Mesoporous Fucoidan Biopolymer Low Pt content Hydrogen evolution reaction

Ultra-low concentration of total organic carbon in ultrapure water using ion-exchange resin embedding silanized magnetic nanoparticles

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Journal of Environmental Sciences 2020年第6期32卷 11-17页

作者： jung Joon Lee Jihyeon park Bo-Hyun Kim Sunjong Lee Department of Advanced Materials Science and Engineering Sungkyunkwan UniversitySuwon 16419South Korea Korea Institute of Industrial Technology 89 Yangdaegiro-gilIpjang-myeonCheonan-si 31056South Korea

Regeneration of pure water is an important issue not only for the healthy life but also for the fine control of precise processes in various *** important issue in ultrahigh purified water is to reduce the amount of total organic carbon(TOC).Herein,we introduce a new approach to reduce the TOC using the surface silanized nanoparticles,in which the magnetic nanoparticles(mNPs)are silanized and then complexed with ion exchange resin(IER)*** Fe3O4 mNPs are surface modified by using high concentrated vinyltrimethoxysilane(VTMS)and then adhered on the surface of IER *** surface modified mNPs have a thick-shell of polysiloxane layer varying from 5 to 22 nm depending on the amount of VTMS used,which leads the significant increase of specific surface *** IER beads embedding VTMS-silanized mNPs achieves about 7μg/L of the TOC level in ultrapure water system,which is two orders less than 228μg/L of the feeding water and one order less than 96μg/L from the system using pristine IER *** result is mainly attributed to the polysiloxane layer forming broccoli-like surface structure and some part by the vinyl group of VTMS exposed to the amines in the water.

关键词： Total organic carbon Ultrapure water Magnetic nanoparticle Ion-exchange resin Hybrid structure

Impregnation approach for poly(vinylidene fluoride)/tin oxide nanotube composites with high tribological performance

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Journal of Materials Science & Technology 2020年第2期37卷 19-25页

作者： min Su park Jin Kyu Kim Tong-Seok Han jung Tae park Jong Hak Kim Department of Chemical and Biomolecular Engineering Yonsei University50 Yonsei-roSeodaemun-guSeoul03722Korea Department of Civil and Environmental Engineering Yonsei University50 Yonsei-roSeodaemun-guSeoul03722Korea Department of Chemical Engineering Konkuk University120 Neungdong-roGwangjin-guSeoul05029Korea

We report a composite material with the high tribological performance,which consists of onedimensional SnO2 nanotubes(ST)and a high molecular weight poly(vinylidene fluoride)(PVDF)matrix in terms of *** of PVDF in N,N-dimethylformamide(DMF)resulted in a facile penetration of PVDF into the inner hollow voids of ST,leading to the close *** between PVDF and ST results in a beneficial effect on the chain arrangement of PVDF,providing anα-phase with better tribological *** ST incorporation,the friction coefficient decreased by 85.0%to 0.408,and the specific wear rate decreased by 69.1%to 0.412,demonstrating the pivotal role of ST as a self-lubricating material due to a large interactive area and PVDF chain rearrangement.

关键词： SnO2 nanotube Composite Friction coefficient Wear rate