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Effect of parallel resonance on the electron energy distribution function in a 60 MHz capacitively coupled plasma

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Plasma Science and Technology 2023年第4期25卷 69-78页

作者： You HE Yeong-Min lim Jun-Ho LEE Ju-Ho KIM Moo-young LEE Chin-Wook CHUNG Department of Electrical Engineering Hanyang University17 Haengdang-dongSeongdong-guSeoul 133-791Republic of Korea Department of Nanoscale Semiconductor Engineering Hanyang University17 Haengdang-dongSeongdong-guSeoul 133-791Republic of Korea

In general,as the radio frequency(RF)power increases in a capacitively coupled plasma(CCP),the power transfer efficiency decreases because the resistance of the CCP *** this work,a parallel resonance circuit is applied to improve the power transfer efficiency at high RF power,and the effect of the parallel resonance on the electron energy distribution function(EEDF)is investigated in a 60 MHz *** CCP consists of a power feed line,the electrodes,and *** reactance of the CCP is positive at 60 MHz and acts like an inductive load.A vacuum variable capacitor(VVC)is connected in parallel with the inductive load,and then the parallel resonance between the VVC and the inductive load can be *** the capacitance of the VVC approaches the parallel resonance condition,the equivalent resistance of the parallel circuit is considerably larger than that without the VVC,and the current flowing through the matching network is greatly ***,the power transfer efficiency of the discharge is improved from 76%,70%,and 68%to 81%,77%,and 76%at RF powers of 100 W,150 W,and 200 W,*** parallel resonance conditions,the electron heating in bulk plasma is enhanced,which cannot be achieved without the VVC even at the higher RF *** enhancement of electron heating results in the evolution of the shape of the EEDF from a biMaxwellian distribution to a distribution with the smaller temperature difference between high-energy electrons and low-energy *** to the parallel resonance effect,the electron density increases by approximately 4%,18%,and 21%at RF powers of 100 W,150 W,and 200 W,respectively.

关键词： capacitively coupled plasma parallel resonance electron energy distribution function

Effect of various red phosphorescent dopants in single emissive white phosphorescent organic light-emitting devices

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Chinese Optics Letters 2017年第5期15卷 53-57页

作者： Jong Hyun lim Jin Wook Kim Geum Jae Yoon Ayse Turak Woo young Kim Department of Green Energy & Semiconductor Engineering Hoseo University Asan 31499 Korea R&D Center A-PRO Co. Ltd. Gunpo 15830 Korea Department of Electrical and Electronic Engineering The University of Hong Kong Hong Kong 070 China Department of Engineering Physcis McMaster University Hamilton Ontario L8S 4L7 Canada

In order to realize single emissive white phosphorescent organic light-emitting devices （PHOLEDs） with three color phosphorescent dopants （red, green, and blue）, the energy transfer between the host material and the three dopants, as well as the among the three dopants themselves, should be considered and optimized. To explore the effect of red phosphorescent dopant on the color rendering index （CRI）, the authors investigate the wavelength position of the maximum emission peak from three phosphorescent dopants. The CRI and luminous efficiency of white PHOLED in which Ir（pq）2（acac） acts as the red phosphorescent dopant are found to be greater than those of devices prepared using Ir（piq）3 and Ir（btp）2（acac） as the emission spectrum has a relatively high intensity near the human perception of blue, red, and green wavelengths. Furthermore, we demonstrate that the performance of the three dopants is related to the absorption characteristics of the red phosphorescent dopant. With a maximum emission peak at 600 nm, Ir（pq）2（acac） has a higher intensity in the concave section between 550 and 600 nm seen for red and blue dopants. In addition, the long metal-to-ligand charge transfer （MLCT） absorption tail of Ir（pq）2（acac） overlaps with the emission spectra of the green dopant, enhancing emission. Such energy transfer mechanisms are confirmed to optimize white emission in the single emissive white PHOLEDs.

关键词： Charge transfer Current density Doping (additives) Emission spectroscopy Energy transfer Light emission

Distribution of dinoflagellate cysts in Yellow Sea sediments

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Acta Oceanologica Sinica 2013年第9期32卷 91-98页

作者： SHIN Hyeon Ho lim Dhongil PARK Soung-Yun HEO Seung KIM So-young Library of Marine Samples Korea Institute of Ocean Science and Technology West Sea Fisheries Research Institute National Fisheries Research&Development Institute Division of Polar Climate Research Korea Polar Research Institute

To investigate the distribution, abundance, and species composition of dinoflagellate cysts in the Yellow Sea, surface sediment samples were collected at 37 sites, including the Korean dump site. Twenty-one di- noflagellate cyst taxa were identified, with the assemblages dominated mainly by Spiniferites bulloideus, Operculodinium centrocarpum, and cyst of Alexandrium catenella/tarnarense type. A high frequency of O. centrocarpum in the Yellow Sea was observed for the first time, and it is likely that this can be attributed to the dynamics of the Yellow Sea Cold Water Mass and the Changjiang （Yangtze） River runoff. Total cyst concentrations ranged from 23 to 48 442 cysts/g dry weight, and high cyst concentrations were recorded adjacent to the dumping site. This result suggests that anthropogenic activities such as ocean dumping s- timulate the growth of dinoflagellates in the Yellow Sea, which in turn leads to high levels of dinoflagellate cyst production.

关键词： Yellow Sea dumping site dinoflagellate cyst Alexandrium catenella/tamarense type Operculo- dinium centrocarpum

Sorption enhanced catalytic CF4 hydrolysis with a three-stage catalyst-adsorbent reactor

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Frontiers of Chemical Science and Engineering 2017年第4期11卷 537-544页

作者： Jae-Yun Han Chang-Hyun Kim Boreum Lee Sung-Chan Nam Ho-young Jung Hankwon lim Kwan-young Lee Shin-Kun Ryi . Advanced Materials and Devices Laboratory Korea Institute of Energy Research (KIER) Daejeon 34129 Korea.. Department of Advanced Materials and Chemical Engineering Catholic University of Daegu Gyeongbuk 38430 Korea.. Department of Environment and Energy Engineering Chonnam National University Gwangju 61186 Korea.. Department of Chemical and Biological Engineering Korea University Seoul 136-701 Korea

In this study, we developed a three-stage catalyst-adsorbent reactor for the catalytic hydrolysis of CF4. Each stage is composed of a catalyst bed followed by an adsorbent bed using Ca（OH）2 to remove HF. The three stages are connected in series to enhance the hydrolysis of CF4 and eliminate a scrubber to dissolve HF in water at the same time. With a 10 wt-% Ce/AlaO3 catalyst prepared by the incipient wetness method using boehmite and a granular calcium hydroxide as an adsorbent, the CF4 conversion in our proposed reactor was 7%-23% higher than that in a conventional single-bed catalytic reactor in the temperature range of 923-1023 K. In addition, experimental and numerical simulation （Aspen HYSYS） results showed a reasonable trend of increased CF4 conversion with the adsorbent added and these results can be used as a useful design guideline for our newly proposed multistage reactor system.

关键词： PFCs catalytic hydrolysis calcium hydro-xide sorption enhanced process simulation

Factors associated with use of gastric cancer screening services in Korea

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World Journal of Gastroenterology 2009年第29期15卷 3653-3659页

作者： young Min Kwon Hyung Taek lim Kiheon Lee Be Long Cho Min Sun Park Ki young Son Sang Min Park Department of Family Medicine Seoul National University Hospital Seoul National University College of Medicine 28 Yunkeon-dong Jongro-gu Seoul 110-744 South Korea Department of Medicine Yonsei University College of Medicine 134 Shinchon-dong Seodaemun-gu Seoul 120-752 South Korea Department of Family Medicine Seoul National University Bundang Hospital and Department of the History of Medicine and Medical Humanities Seoul National University College of Medicine 166 Gumi-ro Bundang-gu Seongnam-si Gyeonggi-do 463-707 South Korea

AIM: To identify the factors associated with participation in gastric cancer screening programs. METHODS: Using data from the Korea National Health and Nutrition Examination Survey 2005 (KNHANES Ⅲ), a nationwide health-related surveyin Korea, a cross-sectional study was performed to investigate the multiple factors associated with gastric cancer screening attendance among persons aged at least 40 years. The study population included 4593 individuals who completed a gastric cancer screening questionnaire and had no previous cancer history. Four groups ofindividual-level or environmental level covariates were considered as potential associated ***: Using KNHANES Ⅲdata, an estimated31.71% of Korean individuals aged at least 40 years adhered to gastric cancer screening recommendations. Subjects who graduated from elementary school[adjusted odds ratio (aOR), 1.66; 95% CI: 1.21-2.26], middle/high school (aOR, 1.38; 95% CI: 1.01-1.89), and university or higher (aOR, 1.64; 95% CI: 1.13-2.37) were more likely to undergo gastric cancer screening than those who received no formal education at all. The population with the highest income tertile had more attendance at gastric screening compared to those with the lowest income tertile (aOR, 1.36; 95% CI: 1.06-1.73). Gastric screening was also negatively associated with excessive alcohol consumption (aOR, 0.71; 95% CI: 0.53-0.96). A positive attitude to preventive medical evaluation was significantly associated with better participation in gastric cancer screening programs (aOR, 5.26; 95% CI: 4.35-6.35). CONCLUSION: Targeted interventions for vulnerable populations and public campaigns about preventive medical evaluation are needed to increase gastric cancer screening participation and reduce gastric cancer mortality.

关键词：服务筛查胃癌韩国

Bioreactor design and validation for manufacturing strategies in tissue engineering

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Bio-Design and Manufacturing 2022年第1期5卷 43-63页

作者： Diana lim Eric S.Renteria Drake S.Sime young Min Ju Ji Hyun Kim Tracy Criswell Thomas D.Shupe Anthony Atala Frank C.Marini Metin N.Gurcan Shay Soker Joshua Hunsberger James J.Yoo Wake Forest Institute for Regenerative Medicine Wake Forest School of MedicineWinston-SalemNC 27157USA Center for Biomedical Informatics Wake Forest School of MedicineWinston-SalemNC 27157USA RegenMed Development Organization(ReMDO) Winston SalemNC 27106USA

The fields of regenerative medicine and tissue engineering offer new therapeutic options to restore,maintain or improve tissue function following disease or *** maximize the biological function of a tissue-engineered clinical product,specific conditions must be maintained within a bioreactor to allow the maturation of the product in preparation for ***,the bioreactor should be designed to mimic the mechanical,electrochemical and biochemical environment that the product will be exposed to in ***-time monitoring of the functional capacity of tissue-engineered products during manufacturing is a critical component of the quality management *** present review provides a brief overview of bioreactor engineering *** addition,strategies for bioreactor automation,in-line product monitoring and quality assurance are discussed.

关键词： Bioreactor Monitoring sensors and automation Manufacturing Tissue engineering Regenerative medicine

Code generation and recognition using a modified ejection system in die-casting process

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China Foundry 2020年第5期17卷 364-371页

作者： Jaekyung Song Jeongsu Lee young Chul Lee Byoung Jun Lee Chaeho lim Industrial Materials and Smart Manufacturing Engineering Korea University of Science and TechnologyDaejeon CityRepublic of Korea Digital Manufacturing Process Group Korea Institute of Industrial TechnologyGyeonggi-doRepublic of Korea

A code-generation and recognition technology that uses a modified ejection system in the diecasting process is *** achieve the highest level of quality management,the first requirement in the manufacturing process is to establish a product management system according to the specific product ***,a method to individually identify each product,such as a barcode or QR code,is required during the production *** manufactured in the die-casting process always have ejector pin(EP)***,an ejection system was modified to generate a unique code using EP *** ejection system has two features:an EP with a modified head to show the direction of rotation,and a function to dependently rotate EPs(five or six EPs)with a constant *** EPs are numbered according to the rotation ***,the EP marks can be viewed as a five-or six-digit code.A program was also developed to individually identify the products by automatically detecting and reading the EPs using deep learning-based object detection and classification technology.

关键词： code recognition die-casting ejection system object detection product management smart manufacturing

Nanocomposite quasi-solid-state electrolyte for high-safety lithium batteries

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Nano Research 2017年第9期10卷 3092-3102页

作者： Hyunji Choi Hyun Woo Kim Jae-Kwang Kim young Jun lim youngsik Kim Jou-Hyeon Ahn School of Energy & Chemical Engineering Ulsan National Institute of Science and Technology (UNIST) Ulsan 689-798 Republic of Korea Department of Solar & Energy Engineering Cheongju University Cheongju Chungbuk 28503 Republic of Korea School of Energy & Chemical Engineering and Research Institute for Green Energy Convergence Technology Gyeongsang National University 900 Gajwa-dong Jinju 660-70 I Republic of Korea

Rechargeable lithium batteries are attractive power sources for electronic devices and are being aggressively developed for vehicular use. Nevertheless, problems with their safety and reliability must be solved for the large-scale use of lithium batteries in transportation and grid-storage applications. In this study, a unique hybrid solid-state electrolyte composed of an ionic liquid electrolyte (LiTFSI/Pyr14TFSI) and BaTiO3 nanosize ceramic particles was prepared without a polymer. The electrolyte exhibited high thermal stability, a wide electrochemical window, good ionic conductivity of 1.3 × 10−3 S·cm−1 at 30 °C, and a remarkably high lithium-ion transference number of 0.35. The solid-state LiFePO4 cell exhibited the best electrochemical properties among the reported solid-state batteries, along with a reasonable rate capability. Li/LiCoO2 cells prepared using this nanocomposite solid electrolyte exhibited high performance at both room temperature and a high temperature, confirming their potential as lithium batteries with enhanced safety and a wide range of operating temperatures.

关键词： nanocomposition solidified ionic liquid shell charge space safety lithium battery

Effects of Mg Enhancement and Heat Treatment on Microstructures and Tensile Properties of Al2Ca-Added ADC12 Die Casting Alloys

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Journal of Materials Science & Technology 2016年第10期32卷 1043-1048页

作者： Gil-Yong Yeom Hyun Kyu lim Shae K.Kim Soong-Keun Hyun young-Ok Yoon Korea Institute of Industrial Technology lncheon 406-840 South Korea Department of Materials Science and Engineering Inha University lncheon 402-751 South Korea

The effects of Mg enhancement and heat treatment on the microstructures and tensile properties of Al_2Ca-added ADC12 die casting alloys were investigated. 0.3% and 0.5% Mg in the form of a master alloy including a trace amount of Al_2Ca were added to conventional ADC12（383 and AlSi10Cu2Fe） alloy with an initial Mg-content of 0.3% to increase the Mg content to 0.6% and 0.8%, respectively. To avoid heat treatmentinduced surface blisters, shortened solution treatment for 15 min at 490 ℃ and artificial aging for 6 h at 150 ℃ was undertaken. The results show that a 10% improvement in the shape factor of eutectic Si particles was achieved for Al_2Ca-added ADC12 with 0.8% Mg compared to the conventional ADC12 in the as-aged condition. Al_2Ca-added ADC12 with 0.8% Mg exhibited a yield strength of 289 MPa, a tensile strength of 407 MPa, and an elongation of 4.22%.

关键词： Al2Ca ADC12 alloy Heat treatment Die casting Inclusion