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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

hot Data Identification with Multiple Bloom Filters： Block-Level Decision vs I/O Request-Level Decision

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Journal of Computer science & Technology 2018年第1期33卷 79-97页

作者： Dongchul park Weiping he h. C. Du Division of Computer and Electronic systems Engineering Hankuk University of Foreign Studies Gyeonggi-do 17035 Korea Intel Corporation Hillsboro OR 97124 U.S.A. Dell storage Eden Prairie MN 55344 U.S.A. Department of Computer science and Engineering University of Minnesota-Twin Cities Minneapolis MN 55455 U.S.A.

hot data identification is crucial for many applications though few investigations have examined the subject. All existing studies focus almost exclusively on frequency. however, effectively identifying hot data requires equally considering recency and frequency. Moreover, previous studies make hot data decisions at the data block level. such a fine-grained decision fits particularly well for flash-based storage because its random access achieves performance comparable with its sequential access. however, hard disk drives （hDDs） have a significant performance disparity between sequential and random access. Therefore, unlike flash-based storage, exploiting asymmetric hDD access performance requires making a coarse-grained decision. This paper proposes a novel hot data identification scheme adopting multiple bloom filters to efficiently characterize recency as well as frequency. Consequently, it not only consumes 50% less memory and up to 58% less computational overhead, but also lowers false identification rates up to 65% compared with a state-of-the-art scheme. Moreover, we apply the scheme to a next generation hDD technology, i.e., shingled Magnetic Recording （sMR）, to verify its effectiveness. For this, we design a new hot data identification based sMR drive with a coarse-grained decision. The experiments demonstrate the importance and benefits of accurate hot data identification, thereby improving the proposed sMR drive performance by up to 42%.

关键词： hot data bloom filter shingled magnetic recording (sMR)

Effects of Weaving Laser on Weld Microstructure and Crack for Al 6k21-T4 Alloy

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Journal of Materials science & Technology 2011年第1期27卷 93-96页

作者： B.h.Kim N.h.Kang W.T.Oh C.h.Kim J.h.Kim Y.s.Kim Y.h.park Department of Materials science and Engineering Pusan National UniversitySan30Jangjeon-dongGeumjeong-guBusan 609-735Korea Department of Materials and Components Engineering Dong-Eui UniversityBusan 614-714Korea Advanced Joining Technology Team KITECH7-47Songdo-dongYeonsu-guIncheon 406-840Korea Division for Dongnam Area Technology service KITECHJisa-dongGanseo-guBusan 618-230Korea

For Al 6k21-T4 overlap weld joint,the shear-tensile strength by using the weaving laser was improved as compared to the case of linear *** the specimen of low strength,the porosity was distributed continuously along the intersection between the plates and fusion ***,for the optimized welding condition,large oval-shaped porosities were located only in the advancing track of the concave ***,the continuity of cracks and porosities played a key role to determine the ***,the weaving width was also the important parameter to control the ***,the concave part had more significant hot and cold cracking in the weld and heat-affected zone（hAZ）,respectively,than the convex part.

关键词： Weaving laser Weld microstructure Void Al alloy

对腔内fly-through CT结肠成像中的粪便标记进行彩色编码容积再现后对阅片效果的影响

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国际医学放射学杂志 2008年第A6期31卷 493-493页

作者： s.h.park s.s.Lee J.K.Kim M.J.Kim h.J.Kim s.Y.Kim 张中伟 Department of Radiology and Research Institute of Ra-diology University of Ulsan College of Medicine Asan Medical Center 388-1Poongnap-DongSongpa-GuSeoul138-040Korea.

本研究经伦理审查委员会批准并获得病人知情同意。研究评价腔内三维fly-through CT结肠成像时对粪便标记进行彩色编码技术的价值,并评价其对阅片效果的影响。

关键词：容积再现彩色编码技术知情同意研究评价编码图像诊断敏感度肠道准备泻剂诊断性能比沙

Multiplexed electrospraying of water in cone-jet mode using a UV-embossed pyramidal micronozzle film

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Microsystems & Nanoengineering 2022年第5期8卷 247-256页

作者： Ji-hun Jeong Kwangseok park hyoungsoo Kim Inyong park Jinyoung Choi seung s.Lee Department of Mechanical Engineering Korea Advanced Institute of Science and TechnologyDaejeon 34141Republic of Korea Department of Environmental Machinery Korea Institute of Machinery and MaterialsDaejeon 34103Republic of Korea Department of Mechanical Engineering Dongshin UniversityNaju 58245Republic of Korea

The electrospraying of water in the cone-jet mode is difficult in practical applications owing to its low throughput and the electrical discharge caused by the high surface tension of water.A film with multiple dielectric micronozzles is essential for multiplexed electrospraying of water in cone-jet mode without electrical ***,a pyramidal micronozzle film with five nozzles was fabricated using the UV-embossing *** pyramidal micronozzle film consisted of pyramidal micronozzles,a micropillar array,and an in-plane extractor,which were proposed to minimize wetting and concentrate the electric field to the water meniscus at the tip of the pyramidal *** electrospraying of water using a single pyramidal micronozzle was visualized by a high-speed camera at a flow rate of 0.15–0.50ml/h with voltages of 0.0–2.3 kV,−1.6 kV,and−4.0 kV at the water,guide ring,and collector,*** distinct modes,the dripping,spindle,and cone-jet modes,were observed and distinguished according to the motion of the water meniscus at the nozzle *** steady Taylor cone and jet were observed in a voltage range of 1.3–2.0 kV in water,particularly in cone-jet *** electrospraying of water in cone-jet mode at a flow rate of 1.5ml/h was performed using a pyramidal micronozzle film,demonstrating the potential for a high-throughput electrospraying system.

关键词： process. film pyramidal

基于超声征象建立甲状腺结节恶性度分级的影像报告与数据系统

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国际医学放射学杂志 2011年第6期 586-586页

作者： J.Y.Kwak J.h.Yoon h.J.Moon E.J.son s.h.park 洪桂洵 Department of Radiology Research Institute of Radiological ScienceYonsei University College of Medicine250 SeongsannoSeodaemun-guSeoul 120-752Korea

目的建立一种实用的甲状腺影像报告与数据系统,对甲状腺结节进行分类并对其恶性度进行分级。方法本研究获得了伦理审查委员会批准,回顾性分析影像资料的研究,免除病人的知情同意。2008年5月—12月间对连续的3414例共3674个局灶性甲状腺... 详细信息

目的建立一种实用的甲状腺影像报告与数据系统,对甲状腺结节进行分类并对其恶性度进行分级。方法本研究获得了伦理审查委员会批准,回顾性分析影像资料的研究,免除病人的知情同意。2008年5月—12月间对连续的3414例共3674个局灶性甲状腺结节行超声引导下细针抽吸活检(FNAB),其中病理及随访资料齐全的1638例(女性

关键词：甲状腺恶性度粒子肉内分泌腺结节数据系统超声征象

Evaluation of spermatogenesis and fertility in F1 male rats after in utero and neonatal exposure to extremely low frequency electromagnetic fields

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Asian Journal of Andrology 2005年第2期7卷 189-194,页

作者： M.K.Chung s.J.Lee Y.B.Kim s.C.park D.h.shin s.h.Kim J.C.Kim Reproductive Toxicology Division Korea Institute of ToxicologyKorea Research Institute of Chemical TechnologyDaejeon 305-600Korea College of Veterinary Medicine Chungbuk National UniversityCheongju 361-763Korea College of Veterinary Medicine Kyungpook National UniversityDaegu 702-701Korea College of Veterinary Medicine Chonnam National UniversityGwangju 500-757Korea

Aim:To determine whether in utero and neonatal exposure to a 60 hz extremely low frequency electromagnetic field (EMF) results in spermatotoxicity and reproductive dysfunction in the F1 offspring of ***:Age-matched, pregnant sprague-Dawley rats were exposed continuously (21 h/day) to a 60 hz EMF at field strengths of 0 (sham control),5,83.3 or 500 μT from day 6 of gestation through to day 21 of *** experimentally generated magnetic field was monitored continuously (uninterrupted monitoring over the period of the study) throughout the ***:No exposure-related changes were found in exposed or sham-exposed animals with respect to the anogenital distance,preputial separation,testis weight,testicular histology,sperm count,daily sperm production, sperm motility,sperm morphology and reproductive capacity of F1 ***:Exposure of sprague- Dawley rats to a 60 hz EMF at field strengths of up to 500 μT from day 6 of gestation to day 21 of lactation did not produce any detectable alterations in offspring spermatogenesis and fertility.

关键词： spermatogenesis electromagnetic fields prenatal exposure postnatal exposure rat

Influence of alloying elements on microstructure and microhardness of Mg-sn-Zn-based alloys

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Transactions of Nonferrous Metals society of China 2010年第12期20卷 2246-2252页

作者： W. L. ChENG s. park W. N. TANG B. s. YOU B. h. KOO school of Nano ＆ Advanced Materials Engineering Changwon National University Changwon 641-773 South Korea Light Metals Research Group Korea Institute of Materials Science （KIMS） Changwon 641-831 South Korea

The phase evolution in （88%-91%）Mg-8%sn-l%Zn-X （X=A1, Mn and/or Ce） system was analyzed via CALPhAD method and simulations were used in precise selection of the chemical composition. The influence of the addition of different alloying elements such as A1, Mn and Ce on the microstructure and microhardness of Mg-8%sn-l%Zn-based alloys was investigated. Combined addition of A1 and Mn shows features distinct from separate addition of A1 or Mn. Additions of l%AI and l%Mn to base alloy result in the formation of massive A1-Mn phase in a-Mg matrix grains. Addition of Ce element can refme the second eutectic precipitates and form intermetallic compounds with sn. Fine rod-like sn-Ce phase presents mainly on the grain boundaries and plays a role in inhibiting grain growth. The effects of alloying elements on Vickers microhardness and indentation size effect of base alloy were examined.

关键词： magnesium alloys alloying elements CALPhAD method hardness indentation size effect

Liquid-liquid extraction and separation of total rare earth(RE) metals from polymetallic manganese nodule leaching solution

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Journal of Rare Earths 2015年第2期33卷 207-213页

作者： P.K.Parhi K.h.park C.W.Nam J.T.park Mineral Resources Research Division Korea Institute of Geoscience & Mineral Resources (KIGAM)Daejeon 305-350 Republic of Korea school of Applied science and Center of Industrial Technology KIIT UniversityBhubaneswar 751024 Odisha India

The study on the solvent extraction for quantitative and selective separation of total rare earth metals from the polymetallic nodule leach liquor was investigated. The typical leach liquor bearing 0. 094 g/L total rare earth, 0. 23 g/L Mn, 0.697 g/L Cu, 0.2 g/L Fe, 0.01 g/L Co and 0.735 g/L Ni was subjected to the removal iron content by precipitation method using Ca（Oh）2 at ph 3.95, prior to solvent extraction of rare earth metals. Three different organo-phosphoric acid reagents（D2EhPA, PC88 A, Cyanex 272） were used to ascertain their performances and selectivity towards the loading of rare earth metals in presence of other base metals. Based on the results of eq. ph effect, the performances of above three extractants followed the order as： D2EhPA〉PC88A〉Cyanex 272. To ensure the absence of extraction of base metals（Cu, Co, Ni）, the eq. ph of the solution was optimized at the level of 2.21, though higher rare earth metal extraction efficiency was observed at higher eq. ph with either of the extractants. The complete process flow diagram for substantial recovery of total rare earth was developed using D2 EhPA. Extraction isotherm plot was constructed at A：O=12：1, 3-stages and phe=2.21, using 0.8 mol/L D2 EhPA and the predicted condition of this study was further confirmed by 6-Cycles Counter Current simulation（CCs） study. The stripping of total rare earth from loaded organic phase（LO） was conducted using hCl solution. Mc-Cabe Thiele diagram study carried out at A：O=1：5 using 4 mol/L hCl showed that three theoretical stages were needed for quantitative stripping of total rare earth. The subsequent stripped solution resulted thus led to contain total rare earth of 5.6 g/L indicating a very high enrichment of total metals by solvent extraction（sX） process.

关键词： total rare earth (RE) metals sX D2EhPA hCl deep sea nodule