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Estimating the subsolar magnetopause position from soft X-ray images using a low-pass image filter

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Earth and Planetary Physics 2024年第1期8卷 173-183页

作者： Hyangpyo Kim Hyunju K.Connor Jaewoong jung Brian M.Walsh David Sibeck Kip D.Kuntz Frederick S.Porter Catriana K.Paw U Rousseau A.Nutter Ramiz Qudsi Rumi Nakamura Michael Collier Space Research Institute Austrian Academy of Sciences8042 GrazAustria Geophysical Institute University of Alaska FairbanksFairbanksAlaska 99775USA National Aeronautics and Space Administration(NASA)Goddard Space Flight Center GreenbeltMaryland 20771USA Astronomy Department University of Maryland College ParkCollege ParkMaryland 20742USA Center for Space Physics Boston UniversityBostonMassachusetts 02215USA Department of Physics and Astronomy Johns Hopkins UniversityBaltimoreMaryland 21218USA Howard University WashingtonDC 20059USA

The Lunar Environment heliospheric X-ray Imager(LEXI)and Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)missions will image the Earth’s dayside magneto pause and cusps in soft X-rays after their respective launches in the near future,to specify glo bal magnetic reconnection modes for varying solar wind *** suppo rt the success of these scientific missions,it is critical to develop techniques that extract the magnetopause locations from the observed soft X-ray *** this research,we introduce a new geometric equation that calculates the subsolar magnetopause position(RS)from a satellite position,the look direction of the instrument,and the angle at which the X-ray emission is *** assumptions are used in this method:(1)The look direction where soft X-ray emissions are maximized lies tangent to the magnetopause,and(2)the magnetopause surface near the subsolar point is almost spherical and thus RSis nea rly equal to the radius of the magneto pause *** create synthetic soft X-ray images by using the Open Geospace General Circulation Model(OpenGGCM)global magnetohydrodynamic model,the galactic background,the instrument point spread function,and Poisson *** then apply the fast Fourier transform and Gaussian low-pass filte rs to the synthetic images to re move noise and obtain accurate look angles for the soft X-ray pea *** the filte red images,we calculate RS and its accuracy for different LEXI locations,look directions,and solar wind densities by using the OpenGGCM subsolar magnetopause location as ground *** method estimates RS with an accuracy of10 *** accuracy improves for greater solar wind densities and during southward interplanetary magnetic *** method ca ptures the magnetopause motion during southwa rd interplaneta ry magnetic field ***,the technique will enable quantitative analysis of the magnetopause motion and help reveal the daysi

关键词： soft X-ray magnetopause reconnection low-pass filter LEXI SMILE

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

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

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

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

Controlled drug delivery systems： the next 30 years

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Frontiers of Chemical Science and Engineering 2014年第3期8卷 276-279页

作者： Yeonhee yun Byung Kook LEE Kinam park Departments of Biomedical Engineering and Pharmaceutics Purdue University West Lafayette IN 47907 USA

The drag delivery scientists need to reexamine the advances made during the past 60 years, analyze our current abilities, and design the future technologies that will propel us to achieve the next level of drug delivery technologies. History shows that the first generation （1G） of drag delivery research during 1950-1980 was quite productive, while the second generation （2G） technologies developed during 1980 2010 were not as prolific. The ultimate goal of drug delivery research is to develop clinically useful formulations to treat various diseases. Effective drug delivery systems can be developed by overcoming formulation barriers and/or biological barriers. The engineering approach has a limit in solving the problem, if biological difficulties are not clearly identified and understood. The third generation （3G） drug delivery systems will have to focus on understanding the biological barriers so that they can be overcome by engineering manipulation of the drug delivery systems. Advances in the next 30 years will be most accelerated by starting open dialogues without any preconceived ideas on drug delivery technologies. The new generation of drug delivery scientists needs to be aware of the successes and limitations of the existing technologies to design the new technologies for meaningful advances in the future.

关键词： drug delivery history formulation barriers,nanotechnology clinical product

Combination of Korean Red Ginseng Extract and Hydrogen-Rich Water Improves Spermatogenesis and Sperm Motility in Male Mice

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Chinese Journal of Integrative Medicine 2020年第5期26卷 361-369页

作者： Ja Yoon Ku Min jung park Hyun Jun park Nam Cheol park Bo Sun Joo Department of Urology Pusan National University HospitalPusan National University School of MedicineBusan(49241)Republic of Korea Biomedical Research Institute Pusan National University HospitalBusan(49241)Republic of Korea The Korea Institute for Public Sperm Bank Busan(49241)Republic of Korea

Objective: To investigate the effect of hydrogen-rich Korean Red Ginseng(KRG) water(HRGW) mixture on the spermatogenesis and sperm motility of mice of different ages. Methods: Eighty young(3 month-old) and aged(12 month-old) male mice were randomly assigned to 4 groups(n=10 per group) including control group, hydrogen-rich water(HRW) group(10 m L/kg daily), KRG group(50 mg/kg daily) and HRGW group(10 m L/kg HRW and 50 mg/kg KRG daily) by an oral zoned needle for 4 weeks. Sperm count and motility were measured using sperm suspension released from cauda epididymis. Serum follicle stimulating hormone(FSH), luteinizing hormone(LH), testosterone, and reactive oxygen species(ROS) in serum have also been estimated. Tubular changes were examined through histological hematoxylin and eosin staining. Expression of antioxidation(PPx3, PPx4, GSTm5 and GPx4), spermatogenesis(inhibin-α, neptin-2 and CREM), antiaging(SIRT1 and SIRT2), and angiogenesis [visfatin and vascular endothelial growth factor(VEGF)] related genes were examined through realtime polymerase chain reaction. Results: HRW and KRG treatment stimulated spermatogenesis followed by increasing sperm production and sperm motility(P<0.05). These effects were strengthened synergistically by a HRGW mixture(P<0.05 or P<0.01). HRGW greatly increased the expressions of antioxidation, antiaging, spermatogenesis related genes and VEGF especially in aged mice(P<0.05). Serum testosterone and FSH levels also increased, while serum ROS level decreased(all P<0.05). Conclusion: HRGW increases sperm production and motility by enhancing antioxidation and stimulating spermatogenesis and sex hormone production, particularly in aged mice.

关键词： aging ginseng infertlit mineral waters sperm mtility