• Title/Summary/Keyword: Large crystal

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Development of physically based 3D computer simulation code TRICSI for ion implantation into crystalline silicon

  • Son, Myung-Sik;Lee, Jun-Ha;Hwang, Ho-Jung
    • Journal of Korean Vacuum Science & Technology
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    • v.1 no.1
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    • pp.1-12
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    • 1997
  • A new three-dimensional (3D) Monte Carlo ion implantation simulator, TRICSI, has been developed to investigate 3D mask effects in the typical mask structure for ion implantation into crystalline silicon. We present the mask corner and mask size effects of implanted boron range profiles, and also show the calculated damage distributions by applying the modified Kinchin-Pease equation in the single-crystal silicon target. The simulator calculates accurately and efficiently the implanted-boron range profiles under the relatively large implanted area, using a newly developed search algorithm for the collision partner in the single-crystal silicon. All of the typical implant parameters such as dose, tilt and rotation angles, in addition to energy can be used for the 3D simulation of ion implantation.

Fatigue Crack Growth Behavior of Steel for High Speed Rail Crossing (고속철도 분기기용 강의 피로균열 진전거동)

  • Choi, Seong-Dae;Nam, Jeoung-Hag;Lee, Jong-Hyung
    • Proceedings of the KSME Conference
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    • 2001.06a
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    • pp.205-210
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    • 2001
  • Fatigue crack growth tests were carried out using high manganese cast steel under constant amplitude loading. Average crystal grain sizes of the material are $200{\mu}m$ and $1000{\mu}m$. For this material, ${\Delta}K_{th}$ is about $8MPa{\sqrt{m}}$ which is quiet large as compared to the general structural steels and the crack growth rate is lower than the general structural steels especilly in the low ${\Delta}K$ regsion. The reason of this behavior is crack closure due to fracture surface roughness and fretting oxide. The relationship between da/dN and the ${\Delta}K_{eq}$ was represented by narrow band regardless of the stress ratio.

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Metallurgical Study of Microconstituents in Transient Liquid Phase Bended Joints of Ni Base Superalloy (Ni기 초내열합금의 액상확산접합부 생성상의 금속조직학적 검토)

  • 김대업
    • Journal of Welding and Joining
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    • v.19 no.1
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    • pp.75-81
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    • 2001
  • The metallurgical study of microconstituents in transient liquid phase bonded joints of Ni-base single crystal superalloys, CMSX-2 and CMSX-4 was investigated employing MBF-80 insert metal. TLP bonding of specimens was carried out at 1,373~1,523K for 0~19.6ks in vacuum. Three types of microconstituents ; needle-like constituent, dot-like constituent and abnormal shape constituent were formed in the bonded interlayer during TLP bonding operation. All these microconstituents were identified as boride. Microconstituents contain a large percentage of Cr in the early stage of bonding. As increasing the holding time, the amount of Cr was decreased and the amount of W, Co and Re were increased. From the analysis results of electron diffraction pattern by TEM, composition of elements in microconstituents were into MBlongrightarrowM$_{5}$B$_3$longrightarrowM$_2$B type with the increased in holding time. It can be explained by the fact that the relative amount of boron in microconstituents was decreased when the holding time was increased.d.

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High Speed Displays Based on a Nonchiral Smectic C Liquid Crystal in an Antiparallel Planar Geometry

  • Jeong, Cherl-Hyun;Na, Jun-Hee;Yoon, Tae-Young;Yu, Chang-Jae;Lee, Sin-Doo
    • 한국정보디스플레이학회:학술대회논문집
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    • 2005.07a
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    • pp.571-574
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    • 2005
  • We demonstrated a high speed liquid crystal (LC) display mode based on a nonchiral smectic C LC in an antiparallel planar geometry. In this antiparallel planar nonchiral smectic C (APNSC) LC mode, analog gray scales and wide viewing properties are achieved using a stepwise thermal annealing process (STAP). Because of an initially stable LC alignment in large area through the STAP, the APNSC LC mode exhibits the characteristics of fast response and high contrast ratio. This new APNSC mode is suitable for processing the dynamic image at a video rate in the next-generation LCDs.

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Multiple-Layered Colloidal Assemblies via Dipping Method with an External Electric Field

  • Im, Sang-Hyuk;Park, O-Ok;Kwon, Moo-Hyun
    • Macromolecular Research
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    • v.11 no.2
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    • pp.110-114
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    • 2003
  • When using the dipping method for crystal formation, mono-layered colloidal crystal structures depend upon the lift-up rate of a glass substrate. The mono-layered colloidal crystals showed the highest quality when the glass substrate was raised at a rate of 3 mm/min at 25 $^{\circ}C$ in a 1 wt% polystyrene colloidal suspension (ethanol medium). In addition, in order to obtain multiple-layered colloidal crystals, an external electric Held was introduced. Multiple-layered colloidal crystals were successfully obtained via this method. The colloidal particles were well ordered over large areas and assembled into a homogeneous structure.

All-Organic Nanowire Field-Effect Transistors and Complementary Inverters Fabricated by Direct Printing

  • Park, Gyeong-Seon;Seong, Myeong-Mo
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.02a
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    • pp.632-632
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    • 2013
  • We generated single-crystal organic nanowire arrays using a direct printing method (liquidbridge- mediated nanotransfer molding) that enables the simultaneous synthesis, alignment and patterning of nanowires from molecular ink solutions. Using this method, single-crystal organic nanowires can easily be synthesized by self-assembly and crystallization of organic molecules within the nanoscale channels of molds, and these nanowires can then be directly transferred to specific positions on substrates to generate nanowire arrays by a direct printing process. The position of the nanowires on complex structures is easy to adjust, because the mold is movable on the substrates before the polar liquid layer, which acts as an adhesive lubricant, is dried. Repeated application of the direct printing process can be used to produce organic nanowire-integrated electronics with twoor three-dimensional complex structures on large-area flexible substrates. This efficient manufacturing method is used to fabricate all-organic nanowire field-effect transistors that are integrated into device arrays and inverters on flexible plastic substrates.

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A Study on the Wall Mobility of Magnetic Domain for the Singel Crystal $YFeO_3$ ($YFeO_3$ 박판 단결정의 자벽이동에 관한 연구)

  • 김종오;한관희
    • Journal of the Korean Ceramic Society
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    • v.23 no.4
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    • pp.47-54
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    • 1986
  • Since the wall mobility of bubble magnetic materials havin g the large q (q=Kac/2$\pi$$M_s^2$) like a $YFeO_3$ has been found to be proportional to the wall energy theoretically crystallographical direction dependence of wall energy calculated by the basis on the spin configuration of the bubble wall which lies in the ac plane was compared with the crystallographical direction dependence of wall mobility which was measured by the experiment. The sample was a single crystal of $YFeO_3$ which was cut into plate normal to the C axis and polished t a thickness of about 60${\mu}{\textrm}{m}$ The measurement of the wall mobility was carried out by optical system using the magneto-optic Faraday effect. From the good agreement of the crystallographical direction dependence of wall mobility and will energy it was found that the spin configuration of the bubble wall suggested is fair.

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Visible Wavelength Photonic Insulator for Enhancing LED Light Emission

  • Ryoo, Kwangki;Lee, Jeong Bong
    • Journal of information and communication convergence engineering
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    • v.13 no.1
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    • pp.50-55
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    • 2015
  • We report design and simulation of a two-dimensional (2D) silicon-based nanophotonic crystal as an optical insulator to enhance the light emission efficiency of light-emitting diodes (LEDs). The device was designed in a manner that a triangular array silicon photonic crystal light insulator has a square trench in the middle where LED can be placed. By varying the normalized radius in the range of 0.3-0.5 using plane wave expansion method (PWEM), we found that the normalized radius of 0.45 creates a large band gap for transverse electric (TE) polarization. Subsequently a series of light propagation simulation were carried out using 2D and three-dimensional (3D) finite-difference time-domain (FDTD). The designed silicon-based light insulator device shows optical characteristics of a region in which light propagation was forbidden in the horizontal plane for TE light with most of the visible light spectrum in the wavelength range of 450 nm to 600 nm.

Deposition of GaN by Chloride VPE and its Thermodynamic Analysis

  • Park, Chinho;Deoksun Yoon;Lee, Soonae;Shin, Moo-Whan
    • Proceedings of the Korea Association of Crystal Growth Conference
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    • 1998.09a
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    • pp.47-51
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    • 1998
  • The GaN thick films were deposited on sapphire substrates by the chloride vapor phase epitaxy (CVPE) technique suing the GaCl3-NH3-N2 chemistry. Thermodynamic simulations were carried out to predict the optimum process windows, and the results were compared with the experiments. A large difference in the growth temperature was observed between the calculation an the experiment, and it indicated that the growth of GaN by the CVPE technique is kinetically limited.

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Crystal Structure of Human TRAIL, the First Molecule With Selective Antitumor Activity

  • Cha, Sun-Shin;Shin, Hang-Cheol;Oh, Byung-Ha
    • Proceedings of the Korean Biophysical Society Conference
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    • 1999.06a
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    • pp.34-34
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    • 1999
  • TRAIL (also known as Apo-2L) is a newly identified cytokine belonging to the large tumor necrosis factor (TNF) family. TRAIL is a novel molecule in that it induces apoptosis in a wide variety of tumor cells but not in normal cells. In order to help elucidating its biological roles and designing mutants with improved therapeutic potential, we have determined the crystal structure of human TRAIL.(omitted)

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