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Effect of Annular Slit Geometry on Characteristics of Spiral Jet

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Journal of Thermal Science 2003年第3期12卷 225-230页

作者： Shigeru Matsuo kwon-hee lee Shinsuke Oda Toshiaki Setoguchi Heuy-Dong Kim Department of Mechanical Engineering Saga University 1 Honjo-machi Saga-shi Saga 840-8502Japan School of Mechanical Engineering College of Natural Science Andong National University388 Song-Cheon Dong Andong Kyung-Pook Korea

A spiral flow using an annular slit connected to a conical cylinder does not need special device to generate a tangential velocity component of the flow and differs from swirling flows. Pressurized fluid is supplied to an annular chamber and injected into the convergent nozzle through the annular slit. The annular jet develops into the spiral flow. In the present study, a spiral jet discharged out of nozzle exit was obtained by using a convergent nozzle and an annular slit set in nozzle inlet, and the effect of annular slit geometry on characteristics of the spiral jet was investigated by using a Laser Doppler Velocimeter (LDV) experimentally. Furthermore, velocity distributions of the spiral jet were compared with those of a normal jet.

关键词： spiral jet flow convergent nozzle annular slit LDV

Experimental Investigation on Noise Suppression in Supersonic Jets from Convergent-Divergent Nozzles with Baffles

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Journal of Thermal Science 2003年第3期12卷 260-263,269页

作者： Yoshiaki Miyazato Yong-Hun Kweon Toshiyuki Aoki Mitsuharu Masuda kwon-hee lee Heuy-Dong Kim Toshiaki Setoguchi Kazuyasu Matsuo Graduate School of Engineering Sciences Kyushu University 6-1 Kasuga-kouen Kasuga Fukuoka816-8580 JapanSchool of Mechanical Engineering Andong National University 388 Songchun-dong AndongKyungbuk 760-749 KoreaGraduate School of Engineering Sciences Kyushu University 6-1 Kasuga-kouen Kasuga Fukuoka816-8580 JapanGraduate School of Engineering Sciences Kyushu University 6-1 Kasuga-kouen Kasuga Fukuoka816-8580 JapanDepartment of Mechanical Engineering Saga University 1 Honjo-machi Saga Saga 840-8502 JapanSchool of Mechanical Engineering Andong National University 388 Songchun-dong AndongKyungbuk 760-749 KoreaDepartment of Mechanical Engineering Saga University 1 Honjo-machi Saga Saga 840-8502 JapanFaculty of Environmental Engineering The University of Kitakyushu 1-1 Hibikino Wakamatsu-kuKitakyushu Fukuoka 808-0135 Japan

The acoustic properties of supersonic jet noise from a convergent-divergent nozzle with a baffle have been studied experimentally over the range of nozzle pressure ratios from 2.0 to 8.0. Acoustic measurements were conducted in a carefully designed anechoic room providing a free-field environment. A new approach for screech noise suppression by a cross-wire is proposed. Schlieren photographs were taken to visualize the shock wave patterns in the supersonic jet with and without the cross-wire. The effects of the baffle and the cross-wire on acoustic properties are discussed. It is shown that the baffle has little effect on the screech frequency for the underexpanded supersonic jet without the cross-wire. Also, the cross-wire introduced in supersonic jets is found to lead to a significant reduction in overall sound pressure level.

关键词：超音速流动噪声控制实验研究收敛-扩散喷管流体力学超音速喷射

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加利福尼亚断层活动的分形聚集研究

地质科学译丛 1996年第1期13卷 21-24页

作者： hee-kwon lee 刘子忠 Department of Geology McMaster University Hamilton.Ontario L8S 4MI.Canada

对加利福尼亚几个区域中从几十年到几十万年的古地震记录的时间分布进行研究。这些年龄数据是通过对断层泥电子自旋共振稳定测年、断层带沉积物^(14)C测年和历史地震得到的。在加利福尼亚中部,圣安德烈斯断层带中的历史记录和圣加夫列... 详细信息

对加利福尼亚几个区域中从几十年到几十万年的古地震记录的时间分布进行研究。这些年龄数据是通过对断层泥电子自旋共振稳定测年、断层带沉积物^(14)C测年和历史地震得到的。在加利福尼亚中部,圣安德烈斯断层带中的历史记录和圣加夫列尔断层带的古地震记录都显示出分线为0.43～0.46的自相似性。加利福尼亚南部圣安德烈斯断层带在历史和古地震时间尺度上的分维为0.67,表明断层位移的分布比加利福尼亚中部更均匀。在时间尺度<1a时,分布是随机的。

关键词：断层活动分形聚集加利福尼亚地区地震

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加州断层活动的分形成丛性

世界地震译丛 1998年第1期29卷 56-60页

作者： hee-kwon lee H.P.Schwarcz 黄子齐河北涿州石油物探局地质研究院

我们研究了加州几个地区古地震记录的时间分布,时间的尺度从数十年至数十万年。分析时使用了断层泥的电子自旋共振坪的定龄方法所获的年龄数据,断层带^(14)C定龄的沉积物及历史地震的记录。在加州中部的圣安德烈斯断层中历史记录和圣加... 详细信息

我们研究了加州几个地区古地震记录的时间分布,时间的尺度从数十年至数十万年。分析时使用了断层泥的电子自旋共振坪的定龄方法所获的年龄数据,断层带^(14)C定龄的沉积物及历史地震的记录。在加州中部的圣安德烈斯断层中历史记录和圣加布里埃尔断层带的古地震记录都具有自相似特性,分维为0.43～0.46。在历史地震和古地震时间尺度上,加州南部的圣安德烈斯断层带的分维是0.67,表明比加州中部更为均匀的断层活动。在小于一年的时间尺度上,很大程度的分布是随机的。

关键词：地震断层活动分形成丛性地震地质

Aligned Ion Conduction Pathway of Polyrotaxane‑Based Electrolyte with Dispersed Hydrophobic Chains for Solid‑State Lithium–Oxygen Batteries

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Nano-Micro Letters 2025年第2期17卷 169-186页

作者： Bitgaram Kim Myeong‑Chang Sung Gwang‑hee lee Byoungjoon Hwang Sojung Seo Ji‑Hun Seo Dong‑Wan Kim Department of Materials Science and Engineering Korea University145 Anam‑RoSeongbuk‑GuSeoul 02841Republic of Korea School of Civil Environmental and Architectural EngineeringKorea University145 Anam‑RoSeongbuk‑GuSeoul 02841Republic of Korea Materials Science and Chemical Engineering Center Institute for Advanced Engineering(IAE)Yongin 17180Republic of Korea

A critical challenge hindering the practical application of lithium–oxygen batteries(LOBs)is the inevitable problems associated with liquid electrolytes,such as evaporation and safety *** study addresses these problems by proposing a modified polyrotaxane(mPR)-based solid polymer electrolyte(SPE)design that simultaneously mitigates solvent-related problems and improves ***-SPE exhibits high ion conductivity(2.8×10^(−3)S cm^(−1)at 25℃)through aligned ion conduction pathways and provides electrode protection ability through hydrophobic chain *** this mPR-SPE into solid-state LOBs resulted in stable potentials over 300 *** situ Raman spectroscopy reveals the presence of an LiO_(2)intermediate alongside Li_(2)O_(2)during oxygen *** situ X-ray diffraction confirm the ability of the SPE to hinder the permeation of oxygen and moisture,as demonstrated by the air permeability *** present study suggests that maintaining a low residual solvent while achieving high ionic conductivity is crucial for restricting the sub-reactions of solid-state LOBs.

关键词： Solid polymer electrolyte Lithium-oxygen batteries Polyrotaxane ion conductivity Hydrophobic chain

Pan-TRK positive uterine sarcoma in immunohistochemistry without neurotrophic tyrosine receptor kinase gene fusions:A case report

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World Journal of Clinical Cases 2025年第2期13卷 39-49页

作者： Seungmee lee Yu-Ra Jeon Changmin Shin Sun-Young kwon Sojin Shin Department of Obstetrics and Gynecology Keimyung University School of MedicineDaegu 42601South Korea Department of Pathology and Institute for Cancer Research Keimyung University School of MedicineDaegu 42601South Korea

BACKGROUND The classification of uterine sarcomas is based on distinctive morphological and immunophenotypic characteristics,increasingly supported by molecular genetic *** on neurotrophic tyrosine receptor kinase(NTRK)gene fusionpositive uterine sarcoma,potentially aggressive and morphologically similar to fibrosarcoma,are limited due to its recent ***-TRK immunohistochemistry(IHC)analysis serves as an effective screening tool with high sensitivity and specificity for NTRK-fusion *** SUMMARY We report a case of a malignant mesenchymal tumor originating from the uterine cervix,which was pan-TRK IHC-positive but lacked NTRK gene fusions,accompanied by a brief literature review.A 55-year-old woman presented to the emergency department with abdominal pain and distension,exhibiting significant ascites and multiple solid pelvic *** examination revealed a tumor encompassing the uterine cervix,extending to the vagina and uterine corpus.A punch biopsy of the cervix indicated NTRK sarcoma with positive immunochemical pan-TRK ***,subsequent next generation sequencing revealed no NTRK gene fusion,leading to a diagnosis of poorly differentiated,advanced-stage *** The clinical significance of NTRK gene fusion lies in potential treatment with TRK inhibitors for positive *** such rare tumors is crucial due to the potential applicability of tropomyosin receptor kinase inhibitor treatment.

关键词： Uterine sarcoma Cervical sarcoma Neurotrophic tyrosine receptor kinase gene fusion Next generation sequencing Case report

Enhancement of magnetic properties of hot pressed/die-upset Dy-free Nd-Fe-B magnets with Cu/Nd coating by wet process

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Rare Metals 2020年第1期39卷 48-54页

作者： Jeehye kwon Dajeong lee Dayoung Yoo Seongkyu Park hee-Ryoung Cha Hae-Woong kwon Junggoo lee Dongyun lee Department of Advanced Circuit Interconnection Pusan National UniversityBusan46241Republic of Korea Department of Nano Fusion Technology Pusan National UniversityBusan46241Republic of Korea Powder and Ceramics Department Korea Institute of Machinery and MaterialsChangwon51508Republic of Korea Department of Materials Science and Engineering Pukyong National UniversityBusan48513Republic of Korea Department of Nanoenergy Engineering Pusan National UniversityBusan46241Republic of Korea

A grain boundary diffusion process(GBDP)was adopted to improve magnetic properties of Dy-free highly coercive Nd-Fe-B permanent magnet by coating thin layers of Nd and Cu in grain *** GBDP of Nd and Cu,Nd and Cu were coated by wet process,e.g.,electrochemical and electroless on Nd-Fe-B magnets,which was fabricated by hot-deformed/die-upset with meltspun *** treatment was performed for 20 min at 600℃followed by several different cooling *** cooling conditions after heat treatment were varied to understand distribution and micros tructural effects of Nd and Cu species in grain *** coercivity increased from 1.565 to 1.637 T in oil cooling rate but remanence decreased,while remanence jumped with little decrease in coercivity in furnace *** tructure analyses suggested that the coercivity was closely related to the cooling rate as well as distribution of *** mechanism of coercivity enhancement due to the cooling rate was discussed based on the results presented here and those in the literature.

关键词： Magnetic materials Electrochemical deposition Diffusion Scanning electron microscopy Coercivity

Characteristics of damaged layer in micro-machining of copper material

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中国有色金属学会会刊：英文版 2009年第B09期19卷 295-300页

作者： Dong-hee kwon Jeong-Suk KIM Myung-Chang KANG Se-Hun kwon Jong-Hwan lee School of Mechanical Engineering Pusan National University National Core Research Center for Hybrid Materials Solution Pusan National University Department of Mechatronics Busan College of Korea Polytechnic Ⅶ

The study on damaged layer is necessary for improving the machinability in micro-machining because the damaged layer affects the micro mold life and micro machine parts. This study examined the ultra-precision micro-machining characteristics, such as cutting speed, feed rate and cutting depth, of a micro-damaged layer produced by an ultra-high speed air turbine spindle. The micro cutting force, surface roughness and plastic deformation layer were investigated according to the machining conditions. The damaged layer was measured using optical microscope on samples prepared through metallographic techniques. The scale of the damaged layer depends on the cutting process parameters, particularly, the feed per tooth and axial depth of the cut. According to the experimental results, the depth of the damaged layer is increased by increasing the feed per tooth and cutting depth, also the damaged layer occurs less in down-milling compared with up-milling during the micro-machining operation.

关键词：机械加工性微观特征损伤层铜材样品制备技术微型机器切削速度切削深度

Fabrication of 3D Printed PCL/PEG Polyblend Scaffold Using Rapid Prototyping System for Bone Tissue Engineering Application

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Journal of Bionic Engineering 2018年第3期15卷 435-442页

作者： Su A Park Sang Jin lee Ji Min Seok Jun hee lee Wan Doo Kim Il Keun kwon Department of Nature-Inspired Nanoconvergence Systems Korea Institute of Machinery and Materials 156 Gajeongbuk-ro Yuseong-gu Daejeon 34103 Republic of Korea Department of Dental Materials School of Dentistry Kyung Hee University 26 Kyungheedae-ro Dongdaemun-gu Seou102447 Republic of Korea

Three-dimensional （3D） printing is a novel process used to manufacture bone tissue engineered scaffolds. This process allows for easy control of the architecture at the micro structure. However, the scaffold properties are typically limited in terms of cellular activity at the scaffold surface due to the printed materials properties. In this study, we developed a polycaprolactone （PCL） blended with polyethylene glycol （PEG） 3D printed scaffold using a rapid prototyping system. The manufactured scaffolds were then washed out to form small pores on the surface in order to improve the scaffolds hydrophilicity. We analyzed the resultant material by using Scanning Electron Microscopy （SEM）, water absorption, water contact angle, in vitro WST-1, and the Bradford assay. Additionally, cells incubated on the fabricated scaffolds were visualized by Confocal Laser Scanning Microscopy （CLSM）. The developed scaffolds exhibited small pores on the strand surface which served to increase hydrophilicity as well as improve cellular proliferation and increase total protein content. Our findings suggest that the presence of small pores on the scaffolds can be used as an effective tool for improving implant cellular interaction. This research indicates that these modified scaffolds can be considered useful for bone tissue engineering applications to improve human health.

关键词： polycaprolactone polyethylene glycol polyblend 3D printing porosity bone tissue engineering