• Title/Summary/Keyword: Size Layer

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A Study on the Boundary Layer Thickness at a Liquid-Vapor Interface (기액계면의 경계층 두께에 관한 연구)

  • Choi, Soon-Ho;Song, Chi-Sung;Choi, Hyun-Kyu;Lee, Jung-Hye;Kim, Kyung-Kun
    • Proceedings of the KSME Conference
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    • 2004.11a
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    • pp.1086-1091
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    • 2004
  • The boundary layer is a very important characteristic of a liquid-vapor interface since it governs the heat and mass transfer phenomena across an interface. However, the thickness of a boundary layer is generally micro- or nano-sized, which requires highly accurate measurement devices and, consequently, costs the related experiments very high and time-consuming. Due to these size dependent limitations, the experiments related with a nano-scaled size have suffered from the errors and the reliability of the obtained data. This study is performed to grasp the characteristics of a liquid-vapor interface, by using a molecular dynamics method. The simulation results were compared with other studies if possible. Although other studies reported that there existed a temperature discontinuity over an interface when the system was reduced to micro- or nano-sized, we confirmed that there was no such a temperature discontinuity.

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Relation of Luminance by Insulator and Phosphor Layer with Thin Type (형광층 및 절연층의 두께에 의한 휘도특성)

  • 박수길;조성렬;손원근;박대희;이주성
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1998.11a
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    • pp.85-88
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    • 1998
  • Light-emitting diode(LEDs), diode arrays, and phosphor display panels are finding increased use in a variety of commercial applications. Present and anticipated application of these devices include solid state indicator(e.g., digital clocks, meter readout) and display systems(e.g., instrument panels, TV display), the application being determined by the light -output capability and size availability(cost) of the particular device. In this work, Phosphor based on ZnS:Cu are used. Relation by luminance with the thickness of insulating layer and phosphor layer are discussed. Increased thickness of insulating layer are stable on voltage to 300V. By considering thickness and voltage, optimal structure and thickness are investigated. Also in order to maximize even surface emission, various sieving process are introduced. Very similar phosphor particle size is selected. Luminance by various wave intensity is also investigated. 150cd/m$^2$ luminance are investigated in stable voltage and frequency.

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Characteristics of Poly-Oxide of New Sacrificial Layer for Micromachining (마이크로머시닝을 위한 새로운 희생층인 다결정-산화막의 특성)

  • Hong, Soon-Kwan;Kim, Chul-Ju
    • Journal of Sensor Science and Technology
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    • v.5 no.1
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    • pp.71-77
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    • 1996
  • Considering that polycrystalline silicon, a structural material of the micromachining, is affected by a sacrificial oxide layer, the poly-oxide obtained by the thermal oxidation of polycrystalline silicon is newly proposed and estimated as the sacrificial oxide layer. The grain size of the polycrystalline silicon grown on the poly-oxide is larger than that of poly crystalline silicon grown on the conventional sacrificial oxide layer. As a result of XRD, increase of (111) textures and formation of additional (220) textures are observed on the polycrystaIline silicon deposited on the poly-oxide. Also, the polycrystalline silicon grown on the poly-oxide represents small and uniform stress.

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Improvement of Migration Lifetime by Dual-sized Grain Structure in 1% Si-Al Metal Line (이중 결정립 구조 1%Si-Al 금속선에 의한 Migration 수명의 개선)

  • 김영철;김철주
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.30A no.6
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    • pp.1-7
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    • 1993
  • After the 1%S-Al metal is deposited, a thin oxide is formed thereon. Then, a single charged Argon(Ar$^{+}$) is ion implanted into the oxide layer, thereby causing the metal grain in the upper surface of the metal layer to become amorphous. Consequently, the grain size will be reduced and the rough surface of the metal layer flattened. However, the remainder of the metal layer beneath the upper surface thereof will still exhibit large grain size and low resistance, because the Argon ion is only implanted to characterized by a dual-sized grain structure which served to reduce interlayer stress, thereby decreasing the rate of stress migration, and to lower the resistivity of the metal line, thereby enhancing the electromigration characteristic thereof. Experiments have shown that the metal line exhibits a metal migration rate which is approximately 700% less than the control group and a standard deviation which is approximately 200% less than these group.p.

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Charge retention characteristics of silicon nanocrystals embedded in $SiN_x$ layer for non-volatile memory devices (비휘발성 메모리를 위한 실리콘 나노 결정립을 가지는 실리콘 질화막의 전하 유지 특성)

  • Koo, Hyun-Mo;Huh, Chul;Sung, Gun-Yong;Cho, Won-Ju
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2007.06a
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    • pp.101-101
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    • 2007
  • We fabricated floating gate non-volatile memory devices with Si nanocrystals embedded in $SiN_x$ layer to achieve higher trap density. The average size of Si nanocrystals embedded in $SiN_x$ layer was ranging from 3 nm to 5 nm. The MOS capacitor and MOSFET devices with Si nanocrystals embedded in $SiN_x$ layer were analyzed the charging effects as a function of Si nanocrystals size.

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Potential Profiles and Capacitances of an Ideally Polarizable Electrode/Hard Sphere Electrolyte System

  • Kim, Sang-Youl;Vedam, K.
    • Bulletin of the Korean Chemical Society
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    • v.11 no.6
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    • pp.487-493
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    • 1990
  • A complete potential profile of an electrical double layer is calculated from a distribution function of charged particles based upon a model where the effect of a charged electrode and the finite size of ion are explicitly included. Electrons which are distributed on the electrode surface are assumed not to penetrate the electrode/electrolyte boundary. Formation of the constant density regions and their effects on potential and the electrical double layer capacitances are studied in great detail. The distribution of surface electrons as well as the constant density regions are found to be essential in characterizing the electrical double layer. The introduction of the ion size into the prior electrical double layer model of an ideally polarizable electrode/point charged electrolyte system, shows a great improvement in its characteristics mostly at negative potential region.

Comparison of Some Tissues in Diploid and Triploid Hybrid between Mud Loach, Misgurnus mizolepis and Cyprinid Loach, M. anguillicaudatus (미꾸라지, Misgurnus mizolepis와 미꾸리, M. anguillicaudatus간 잡종 및 잡종 3배체 일부 조직에서의 세포 및 핵 크기)

  • 박인석;김동수
    • Development and Reproduction
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    • v.4 no.1
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    • pp.19-28
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    • 2000
  • Diploid and triploid hybrid between female mud loach Misgurnus mizolepis and male cyprinid loach, M. andguillicaudatus were produced, using artificial propagation. The influence of hybridization and triploidization on characteristics of the some tissues of retina optic tectum and trunk kidney in loach was determined histologically. Diploid hybrid have almost size similarities in nucleus and the cell size of some tissues to both parents. In the triploid hybrid the nucleus and/or the cell size in erythrocyte, horizontal cell in inner nuclear layer of retina ganglion cell in ganglion cell layer of retina, neuronal cell in granular layer of optic tectum, and secondary proximal tubule cell of trunk kidney, are much larger than those of the corresponding cells in the diploid hybrid individuals. However, triploid hybrid showed fewer number of cells in outer nuclear layer in retina and nuclei in secondary proximal tubule of trunk kidney than in diploid hybrid. Results of this study suggest that some characteristics in the triploid hybrid exhibiting larger cell and nucleus size with fewer number of cell than diploid hybrid can be useful criteria for the distinction between diploid hybrid and triploid hybrid, and the ploidy level in loach.

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Blind via Hole manufacturing technology using UV Laser (UV 레이저에 의한 블라인드 비아홀 가공)

  • 장정원;김재구;신보성;장원석;황경현
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2002.10a
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    • pp.160-163
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    • 2002
  • Micro via hole Fabrication is studied by means of minimizing method to circuit size as many electric products developed to portable and minimize. Most of currently micro via hole fabrication using laser is that fabricate insulator layer using CO2 Laser after Cu layer by etching, or fabricate insulator layer using IR after trepanning Cu by UV. In this paper, it was performed that a metal layer and insulator layer were worked upon only one UV laser, and increase to processing speed by experiment.

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Sound Absorption Property of the Leaves of Two Evergreen Broad-Leaved Tree Species, Dendropanax morbiferus and Fatsia japonica

  • JUNG, Su Young;YEOM, Da-Hye;KONG, Ree-Keun;SHIN, Gab Gyun;LEE, Kwang Soo;BYEON, Hee Seop
    • Journal of the Korean Wood Science and Technology
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    • v.48 no.5
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    • pp.631-640
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    • 2020
  • In this study, the effect of specimen size and layer thickness on the sound absorption of the leaves of two evergreen broad-leaved tree species, Dendropanax morbiferus and Fatsia japonica, was investigated. The specimen sizes of 0.5 × 0.5, 1.0 × 1.0, and 2.0 × 2.0 ㎠ and layer thicknesses of 1.00, 1.75, and 2.50 cm were considered. At the layer thickness of 2.5 cm, the leaf of the D. morbiferus showed no significant difference in sound absorption coefficients (SACs) as the sample size varied, however, a significant change in SACs was recorded in that of the F. japonica. At 1.0-cm thickness, the SACs of the F. japonica leaf varied more remarkably with the sample size. The 2.50-cm-thick F. japonica leaf with the specimen size 0.5 × 0.5 ㎠ exhibited the highest sound absorption effect among all samples investigated.

Thermal Properties of Diamond Aligned Electroless Ni Plating Layer/Oxygen Free Cu Substrates (다이아몬드 배열 무전해 니켈 도금층/무산소동 기판의 열전도도 특성)

  • Jeong, Da-Woon;Kim, Song-Yi;Park, Kyoung-Tae;Seo, Seok-Jun;Kim, Taek Soo;Kim, Bum Sung
    • Journal of Powder Materials
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    • v.22 no.2
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    • pp.134-137
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    • 2015
  • The monolayer engineering diamond particles are aligned on the oxygen free Cu plates with electroless Ni plating layer. The mean diamond particle sizes of 15, 23 and $50{\mu}m$ are used as thermal conductivity pathway for fabricating metal/carbon multi-layer composite material systems. Interconnected void structure of irregular shaped diamond particles allow dense electroless Ni plating layer on Cu plate and fixing them with 37-43% Ni thickness of their mean diameter. The thermal conductivity decrease with increasing measurement temperature up to $150^{\circ}C$ in all diamond size conditions. When the diamond particle size is increased from $15{\mu}m$ to $50{\mu}m$ (Max. 304 W/mK at room temperature) tended to increase thermal conductivity, because the volume fraction of diamond is increased inside plating layer.