• Title/Summary/Keyword: Nano Science

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Trends of Technologies for High Performance Polymer Barriers against Radiation (고성능 방사선 고분자 차단막 기술동향)

  • Lee, Gi-Bbeum;Park, Sung-Eun;Kim, In-Woo;Jeong, Kwang-Un;Lee, Hong-Ki;Nah, Chang-Woon
    • Elastomers and Composites
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    • v.46 no.2
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    • pp.94-101
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    • 2011
  • The conventional radiation barriers may show some disadvantages such as heavy weight and possibility of poisoning human bodies because they are composed of lead plates or resin plates containing large amounts of lead powders. Another disadvantage may be direct penetration of radiation through small pin holes. In this article, technologies of multi-layered polymer barriers against radiation, which has been extensively focused recently, will be introduced. A new concept of radiation protection as well as improving endurance with employing nano-layered inorganic particles is introduced.

Electrical Characteristics of Ge-Nanocrystals-Embeded MOS Structure

  • Choi, Sam-Jong;Park, Byoung-Jun;Kim, Hyun-Suk;Cho, Kyoung-Ah;Kim, Sang-Sig
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2005.11a
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    • pp.3-4
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    • 2005
  • Germanium nanocrystals(NCs) were formed in the silicon dioxide($SiO_2$) on Si layers by Ge implantation and rapid thermal annealing process. The density and mean size of Ge-NCs heated at $800^{\circ}C$ during 10 min were confirmed by High Resolution Transmission Electron Microscopy. Capacitance versus voltage(C-V) measurements of MOS capacitors with single $Al_2O_3$ capping layers were performed in order to study electrical properties. The C-V results exhibit large threshold voltage shift originated by charging effect in Ge-NCs, revealing the possibility that the structure is applicable to Nano Floating Gate Memory(NFGM) devices.

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Synthesis and Reactivity of a Mononuclear Manganese(II) Complex Having Pseudo-Seven Coordination Environment

  • Yoon, Jee-Hee;Seo, Mi-Sook;Kim, Young-Mee;Kim, Sung-Jin;Yoon, Sung-Ho;Jang, Ho G.;Nam, Won-Woo
    • Bulletin of the Korean Chemical Society
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    • v.30 no.3
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    • pp.679-682
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    • 2009
  • Utilizing a planar five coordinating N3S2 ligand, 2,6-bis(2-methylthiophenyliminomethyl)pyridine, a pseudo 7-coordinated manganese(II) complex with two labile triflate anions in the axial positions was synthesized. The reaction of the manganese(II) complex with an oxidant, iodosylbenzene, produced a metastable high-valent manganese(IV)-oxo species at 0 ${^{\circ}C}$. The high-valent Mn(IV)-oxo intermediate was characterized with a UV-vis spectrophotometer and an electrospray ionization mass spectroscopy. Reactivity studies of the Mn(IV)=O species revealed that the intermediate is capable of oxygenating $PPh_3$ and N-dealkylating N,N-dimethyl-toludine.

Hardware implementation of a CMOS image sensor pixel using complemental signal path (상보형 신호경로 방식의 CMOS 이미지 센서 픽셀의 하드웨어 구현)

  • Jung, Jin-Woo;Kwon, Bo-Min;Kim, Ji-Man;Park, Ju-Hong;Park, Yong-Su;Lee, Je-Won;Song, Han-Jung
    • Journal of Sensor Science and Technology
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    • v.18 no.6
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    • pp.475-484
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    • 2009
  • In this paper, an analysis of the complementary CMOS active pixel and readout circuit is carried out. Complementary pixel structure which is different from conventional 3TR APS structure consists of photo diode, reset PMOS, several NMOSs and PMOSs sets for complementary signals. Proposed CMOS image sensors pixel has been fabricated using 0.5 standard CMOS process. Measured results show that the output signal range is from 0.8 V to 3.8 V. This output signal range increased 125 % compared to conventional 3TR pixel in the condition of 5 V power supply.

Preparation and Characterization of the Impregnation to Porous Membranes with PVA/PSSA-MA/THS-PSA for Fuel Cell Applications (연료전지 응용을 위한 다공성막에 가교된 PVA/PSSA-MA/THS-PSA의 함침을 통한 고내구성 이온교환막의 제조 및 특성 연구)

  • Kim, Il-Hyoung;Kim, Sung-Pyo;Lee, Hak-Min;Park, Chan-Jong;Rhim, Ji-Won;Cheong, Seong-Ihl
    • Membrane Journal
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    • v.21 no.3
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    • pp.299-305
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    • 2011
  • This study deals with the preparation of polymeric electrolyte membranes having high durability for the application of fuel cells. The membranes under investigation were prepared the impregnation to porous polyethylene membranes with poly(vinyl alcohol)(PVA), poly(styrene sulfonic acid-co-maleic acid), and (PSSA-MA)3-(trihydroxysilyl)-1-propanesulfonic acid (THS-PSA). To characterize the resulting membranes, the water contents, the contact angles, FT-IR, the proton conductivity and the the modulus were measured. The proton conductivity of 30% content of THS-PSA at $55^{\circ}C$ gave excellent $1.27{\times}10^{-1}S/cm$ and the mechanical strength was improved 7 times higher up to the THS-PSA content 15%, as a result, the durability was elevated extensively.