• 제목/요약/키워드: core particle

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The fabrication of TFTs for LCD using the 3mask process

  • Yoo, Soon-Sung;Cho, Heung-Lyul;Kwon, Oh-Nam;Nam, Seung-Hee;Chang, Yoon-Gyoung;Kim, Ki-Yong;Cha, Soo-Yeoul;Ahn, Byung-Chul;Chung, In-Jae
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.II
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    • pp.948-951
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    • 2005
  • New technology that reduces photolithography process steps from 4 to 3 in fabrication of TFT LCD is introduced. The core technology for 3mask-TFTs is the lift-off process [1], by which the PAS and PXL layer are formed simultaneously. To evaluate the stability of this lift-off process, outgases from photo resist on a substrate during ITO deposition and the quality of ITO film were analyzed and the conventional photo resist stripper machine which operates lift-off process was examined to see its ability to reduce particle problems of the machine. Through the development of total process and design for TFTs using this 3mask technology, panels in TN and IPS modes which exhibit same performances of a display using a conventional process were achieved. In addition, this process was already verified in the mass production line and now some products are being produced by the 3mask technology.

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아크방전으로 제조된 나노입자를 이용한 리튬이온전지 음극재료의 연구 (The Research on the Nanoparticles Prepared by Arc-Discharge Method as Anode Materials for Lithium Ion Batteries)

  • 김형조;;김형진;박원조
    • 동력기계공학회지
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    • 제17권1호
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    • pp.104-109
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    • 2013
  • Tin and Tinoxide nanoparticles were prepared by arc-discharge nanopowder process. The negative electrode were fabricated using Tin and Tinoxide nanopower. The microstructure and electrochemistry properties were investigated and compared between Tin and Tinoxide. The oxidation film has microstructure of core/shell type and the shell which was attached around Tin nanoparticle consisted of amorphous $SnO_2$. The shape of Tinoxide nanoparticles was formed with irregular shape in comparison with Tin particle. Initial discharge capcity of Tinoxide electrode possesed about 1000mAh/g, which is about 320mAh/g higher than Tin electrode. Irreversible capacity of Tin electrode is much higher than Tinoxide. The cycle performance of Tinoxide electrode was indicated that is batter than Tin. The Tin negative electrode lost most of capacity after 4 cycle but Tinoxide electrode still retained the capacity. The Tinoxide does show some promise as Li-ion battery anode due to their large reversible capacity at low potentials.

An Experimental Study on the Transient Interaction Between High Temperature Thermite Melt and Concrete

  • Nho, Ki-Man;Kim, Jong-Hwan;Kim, Sang-Baik;Shin, Ki-Yeol;Mo Chung
    • Nuclear Engineering and Technology
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    • 제29권4호
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    • pp.336-347
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    • 1997
  • During postulated severe accidents in Light water Reactors, molten corium which was ejected from the reactor vessel bottom, may erode the concrete basemat of the containment and there by threaten the containment integrity. This study experimentally examines the molten core-concrete interaction (MCC) using 20kg of thermite melt (Fe + $Al_2$O$_3$) and the concrete, used in Yonggwang Nuclear Power Plant Units 3 and 4 (YGN 3 & 4) in Korea. The measured data are the downward heat fluxes, concrete erosion rate, gases and particle generation rates during MCCI. Transient results ore compared with those of TURCIT experiment conducted by SNL in USA. The peak downward heat flux to the concrete was measured to be about 2.1㎿/$m^2$. The initial concrete erosion rate was 175cm per hour, decreasing to 30cm per hour. It was shown from the post-test that the erosion was progressed downward up to 18mm in the concrete slug.

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Improving the Neutronic Characteristics of a Boiling Water Reactor by Using Uranium Zirconium Hydride Fuel Instead of Uranium Dioxide Fuel

  • Galahom, Ahmed Abdelghafar
    • Nuclear Engineering and Technology
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    • 제48권3호
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    • pp.751-757
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    • 2016
  • The present work discusses two different models of boiling water reactor (BWR) bundle to compare the neutronic characteristics of uranium dioxide ($UO_2$) and uranium zirconium hydride ($UZrH_{1.6}$) fuel. Each bundle consists of four assemblies. The BWR assembly fueled with $UO_2$ contains $8{\times}8$ fuel rods while that fueled with $UZrH_{1.6}$ contains $9{\times}9$ fuel rods. The Monte Carlo N-Particle Transport code, based on the Mont Carlo method, is used to design three dimensional models for BWR fuel bundles at typical operating temperatures and pressure conditions. These models are used to determine the multiplication factor, pin-by-pin power distribution, axial power distribution, thermal neutron flux distribution, and axial thermal neutron flux. The moderator and coolant (water) are permitted to boil within the BWR core forming steam bubbles, so it is important to calculate the reactivity effect of voiding at different values. It is found that the hydride fuel bundle design can be simplified by eliminating water rods and replacing the control blade with control rods. $UZrH_{1.6}$ fuel improves the performance of the BWR in different ways such as increasing the energy extracted per fuel assembly, reducing the uranium ore, and reducing the plutonium accumulated in the BWR through burnup.

Estradiol Valerate Exerts Neuroprotective Effects in Ischemic Rat Brain when Administered after Middle Cerebral Artery Occlusion

  • Yoo, Seong-Jin;Yu, Jeong-Min;Youm, Mi-Young;Kim, Do-Rim;Kim, Jee-Yun;Kang, Sung-Goo
    • 한국수정란이식학회:학술대회논문집
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    • 한국수정란이식학회 2002년도 국제심포지엄
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    • pp.111-111
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    • 2002
  • Stroke occurs when local thrombosis, embolic particle or the rupture of blood vessele interrupts the blood floe to the brain. $\beta$-estradiol 17-valerate has been reported to exert neuroprotective effects when administered before an ischemic insult. Recently, the pathophysiology of cerebral ischemia has been studied extensively in rat with various methods. In the present study, we investigates whether $\beta$-estrodiol 17-valerate can protect against brain injury. RNA sample were extracted from the hippocampus of female rat, reverse-transcription in the presence of [$\alpha$32p] dATP. Differential gene express-ion profiles were revealed (Bone morphogenetic protein type 1A receptor, Protein disulphide isomerase, Leukemia inhibitor factor receptor, cytochrome bc- 1 complex-x core P, thiol-specific antioxidant protein). RT-PCR was used to validate the relative expression pattern obtained by the cDNA array. The precise relationship between the early expression of recovery genes and stroke is a matter of luther investigation. This Study was supported by the Korea Science and Engineering Foundation(KOSEF) through the Biohealth Products Research Center(BPRC), Inje University, Korea.

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Overview of Wood Plastic Composites: Focusing on Use of Bio-based Plastics and Co-extrusion Technique

  • Kim, Birm-June
    • Journal of the Korean Wood Science and Technology
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    • 제42권5호
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    • pp.499-509
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    • 2014
  • Wood filler is a porous and anisotropic material having different size, shape, and aspect ratio. The use of wood fillers such as wood particle, wood flour, and wood pulp in wood plastic composites (WPCs) are growing rapidly because these wood fillers give improved strength and stiffness to WPCs. However, the wood fillers have originally poor compatibility with plastic matrix affecting the mechanical properties of WPCs. Therefore, to improve compatibility between wood and plastic, numbers of physical and chemical treatments were investigated. While the various treatments led to improved performances in WPC industries using petroleum-based plastics, full biodegradation is still issues due to increased environmental concerns. Hence, bio-based plastics such as polylactide and polyhydroxybutyrate having biodegradable characteristics are being applied to WPCs, but relatively expensive prices of existing bio-based plastics prevent further uses. As conventional processing methods, extrusion, injection, and compression moldings have been used in WPC industries, but to apply WPCs to engineered or structural places, new processing methods should be developed. As one system, co-extrusion technique was introduced to WPCs and the co-extruded WPCs having core-shell structures make the extended applications of WPCs possible.

Energy spectrum of particles arriving at the ground and S(800) determination by Monte Carlo simulation for Telescope Array

  • Kim, Ji-Hee;Roh, Soon-Young;Ryu, Dong-Su;Kang, Hye-Sung;Kasahara, Katuaki;Kido, Eiji;Taketa, Akimichi
    • 천문학회보
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    • 제35권2호
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    • pp.58.1-58.1
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    • 2010
  • Telescope Array (TA) experiment in Utah, USA, observes ultrahigh-energy cosmic rays (UHECRs); UHECRs refer cosmic rays with energy above $10^{18}eV$. Using COSMOS and CORSIKA, we have produced a library of over 1000 thinned extensive air shower (EAS) simulations with the primary energies ranging from $10^{18.5}eV$ to $10^{20.25}eV$ and the zenith angle of primary cosmic ray particle from $0^{\circ}$ to $45^{\circ}$. Here, we present the energy spectrum of particles arriving at the ground. We have also calculated the detector response evaluated using GEANT4 simulations. Here, we discuss S(800), i.e. the signal at a distance of 800 m from the shower core, as the primary energy estimator.

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$Co(OH)_2$로부터 수열법에 의한 코발트 분말제조 (Hydrothermal Reduction of $\Co(OH)_2$ to Cobalt Powder Preparation)

  • 김동진;정헌생
    • 한국재료학회지
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    • 제9권7호
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    • pp.675-679
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    • 1999
  • $PdCl_2$를 촉매제로 사용한 수소환원분위기에서 $Co(OH)_2$ 로부터 약 400nm크기인 구형의 코발트분말 제조에 관한 연구를 수행하였다. 본 실험에서 코발트의 환원반응속도는 표면반응 코어모델식에 잘 일치하였으며 이때 활성화 에너지는 $145~195^{\circ}C$에서 약 55.6KJ/mol 이었다. 또한 코발트의 환원속도는 초기 수소분압의 0.63승에 비례하는 가스화학흡착반응식으로 표시할 수 있다.

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레이더 흡수특성이 있는 저적외선 방출 복합섬유의 제조 및 특성 연구 (Preparation and Characterization of Low Infrared Emissivity Bicomponent Fibers with Radar Absorbing Property)

  • Yu Bin;Qi Lu
    • 폴리머
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    • 제30권2호
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    • pp.124-128
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    • 2006
  • Heavy weight of the camouflage materials was always the main problem. To solve it, the low infrared emissivity fibers with the radar absorbing property (LIFR) were prepared. The low infrared emissivity fibers (LIF) were firstly melt-spun by co-extrusion of polypropylene (PP) and PP/various fillers master-batches using general conjugate spinning. The infrared emissivity of LW with AA and ZnO was decreased respectively compared with that of pure polypropylene fibers. The infrared emissivity of LIF with 15 wt% Al and 2 wt% ZnO in the sheath-part can reach 0.58. To improve LIF radar absorbing property, LIFR was prepared by filling the 50 wt% ferrite and bronze in the core-part of LIF. The radar absorbing efficacy of LIFR was good and the infrared emissivity was low. For the characterization, fiber electron intensity instrument and differential scanning calorimetry (DSC) were used for the analysis of mechanical properties, thermal and crystallization behavior of the spun-fibers. Scanning electron microscopy (SEM) was carried out to observe the particle distribution of the bicomponent fibers.

Methotrexate-Incorporated Polymeric Micelles Composed of Methoxy Poly(ethylene glycol)-Grafted Chitosan

  • Jeong, Young-Il;Seo, Dong-Hyuk;Kim, Don-Gon;Choi, Chang-Yong;Jang, Mi-Kyeong;Nah, Jae-Woon;Park, Yoon-Kyung
    • Macromolecular Research
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    • 제17권7호
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    • pp.538-543
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    • 2009
  • In this study, methotrexate (MTX)-encapsulated polymeric micelles using methoxy poly(ethylene glycol) (MPEG)-grafted chitosan (ChitoPEG) copolymer were prepared. The MIX-incorporated polymeric micelles of ChitoPEG copolymer has a particle size of around 50-100 nm. In 1H nuclear magnetic resonance (NMR) study, the specific peaks of MTX disappeared in heavy water ($D_2O$) and only the specific peak of MPEG was observed, while all of the peaks were confirmed in dimethyl sulfoxide (DMSO). These results indicated that MTX was complexed with chitosan and then formed an ion complex inner-core of the polymeric micelle in an aqueous environment. The drug contents of the polymeric micelle were around $4{\sim}12%$ and the loading efficiency of MTX in the polymeric micelles was higher than 60% (w/w) for all of the formulations. The cytotoxicity of MIX and MTX-incorporated polymeric micelle against CT26 tumor cells was not significantly changed.