• Title/Summary/Keyword: growth characterization

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Influence of Silicon and Seed Particles on the Reconstruction Characteristics and Exaggerated Grain Growth of MgO Protective Layer by Over-Frequency Accelerated Discharge in ACPDPs

  • Kwon, Sang-Koo;Kim, Jeong-Ho;Moon, Seung-Kyu;Choi, Jong-Kwon;Park, Kyu-Ho;Han, Sung-Su
    • 한국정보디스플레이학회:학술대회논문집
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    • 2008.10a
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    • pp.957-960
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    • 2008
  • The influences of silicon and MgO seed particle on the reconstruction characteristics of MgO protective layer were investigated to clarify the mechanism of reconstruction and exaggerated grain growth (EGG) in AC-PDP. The reconstruction and EGG are closely correlated with the driving force for nucleation and growth, interface energy and initial size distribution of MgO protective layer in plasma space during discharge in AC-PDP.

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Direct Growth of Graphene on Boron Nitride/Copper by Chemical Vapor Deposition

  • Jin, Xiaozhan;Park, J.;Kim, W.;Hwang, Chanyong
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.02a
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    • pp.590-590
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    • 2013
  • Direct growth of graphene using CVD method has been done on CVD grown boron nitride substrate. From the SEM image, we have shown that the size of grain of graphene could be clearly controlled by varying the amount of injected hydrocarbon. To convince the existence of graphene on boron nitride, XPS and Raman has been checked. Both B1s and N1s peaks in XPS spectra and the Raman peak around 1,370 $cm^{-1}$ demonstrated that boron nitride did remain after high temperature treatment during the graphene growth process. And along the graphene grain boundary, the Raman fingerprint of graphene was neatly appeared.

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Reconstruction Characteristics of MgO (111) Textured Protective Layer by Over-Frequency Accelerated Discharge in AC Plasma Display Pannel

  • Kwon, Sang-Koo;Kim, Jeong-Ho;Moon, Seung-Kyu;Kim, Hyun-Ha;Park, Kyu-Ho;Kim, Sung-Tae
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08a
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    • pp.224-227
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    • 2007
  • The reconstruction characteristics of MgO (111) textured protective layer by over-frequency accelerated discharge in AC-PDP were investigated and correlated to the variations of electronic structures. The reconstruction process and exaggerated grain growth (EGG) were explained by defect-assisted 2-D nucleation and growth mechanism combined with charged cluster model.

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Crystal Growth and Characterization of Compound Semiconductor Materials (화합물 반도체 재료의 결정성장과 특성평가)

  • 민석기
    • Korean Journal of Crystallography
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    • v.1 no.2
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    • pp.115-125
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    • 1990
  • We have investigated bulk and hetero-epitaxial growth of GaAs single crystal. Various growth techniques such as HB, HZM, and VGF for high quality bulk GaAs were successfully developed by appling the specially designed DM(direct monitoring) furnace. Al GaAs/GaAs superlattice structure and In(x)Ga(1-x) As/GaAs epilayers were also grown by MOCVD and VPE, respectively. The characterization of GaAs single crystals and epilayers was made by X-ray diffraction, Hall effect, PL, chemical etching and angle lapping technique.

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Morphological Characterization and Culture Conditions of A White Mutant of Ganoderma Iucidum (영지버섯 백색 변이주의 형태적 특성 및 최적 배양조건)

  • 조수묵;서건식;유승헌;유익동;신관철
    • Microbiology and Biotechnology Letters
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    • v.21 no.6
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    • pp.520-526
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    • 1993
  • A morphologically different form of Ganoderma lucidum was isolated from a cultivator's farm, and its optimum growth conditions were determined. A major difference in their morphology was color of fruit bodies. Fruit bodies of the mutant were white wherase those of normal Ganoderma lucidum were red. Spores of the mutant were global and mycelia were thin. Mycelial growth of this white mutant was favorable on potato sucrose agar medium, and optimum pH of the medium was 5.5.

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Novel Synthesis and Nanocharacterization of Graphene and Related 2D Nanomaterials Formed by Surface Segregation

  • Fujita, Daisuke
    • Proceedings of the Korean Vacuum Society Conference
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    • 2015.08a
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    • pp.60-60
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    • 2015
  • Nanosheets of graphene and related 2D materials have attracted much attention due to excellent physical, chemical and mechanical properties. Single-layer graphene (SLG) was first synthesized by Blakely et al in 1974 [1]. Following his achievements, we initiated the growth and characterization of graphene and h-BN on metal substrates using surface segregation and precipitation in 1980s [2,3]. There are three important steps for nanosheet growth; surface segregation of dopants, surface reaction for monolayer phase, and subsequent 3-D growth (surface precipitation). Surface phase transition was clearly demonstrated on C-doped Ni(111) by in situ XPS at elevated temperatures [4]. The growth mode was clarified by inelastic background analysis [5]. The surface segregation approach has been applied to C-doped Pt(111) and Pd(111), and controllable growth of SLG has been demonstrated successfully [6]. Recently we proposed a promising method for producing SLG fully covering an entire substrate using Ni films deposited on graphite substrates [7]. A universal method for layer counting has been proposed [8]. In this paper, we will focus on the effect of competitive surface-site occupation between carbon and other surface-active impurities on the graphene growth. It is known that S is a typical impurity of metals and the most surface-active element. The surface sites shall be occupied by S through surface segregation. In the case of Ni(110), it is confirmed by AES and STM that the available surface sites is nearly occupied by S with a centered $2{\times}2$ arrangement. When Ni(110) is doped with C, surface segregation of C may be interfered by surface active elements like S. In this case, nanoscopic characterization has discovered a preferred directional growth of SLG, exhibiting a square-like shape (Fig. 1). Also the detailed characterization methodologies for graphene and h-BN nanosheets, including AFM, STM, KPFM, AES, HIM and XPS shall be discussed.

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Preparation and characterization of ZnWO4 nanocrystallines and single crystals

  • Lim, Chang-Sung
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.20 no.5
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    • pp.197-201
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    • 2010
  • $ZnWO_4$ nanocrystallines were prepared from polymeric complex method using microwave irradiation. The average nanocrystalline sizes were 18~25 nm showing an ordinary tendency to increase with the temperatures from 400 to $600^{\circ}C$. Bulk type single crystals of $ZnWO_4$ were grown successfully in the [100], [010] and [001] directions using the Czochralski method. The effect of the growth parameters, such as the rotation speed, pulling rate and diameter of the grown crystals, were examined. The hardness, thermal expansion coefficients and dielectric constants of the crystals were evaluated.

Bioassays of Plant Hormones and Plant Growth Regulating Substances II. Abscisic Acid and Brassinolide (식물홀몬 및 생장조절물질의 생물검정기술 II. Abscisic Acid 및 Brassinolide)

  • 최충돈
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.34 no.s01
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    • pp.16-25
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    • 1989
  • A bioassay is a test system using a living organism (in whole or in part) to determine the presence or relative potency of chemical substances. The development and uses of bioassay are intimately linked to the discovery and characterization of the major classes of plant hormones. An application of this relationship is helpful for understanding the concept of plant hormones as well as the use of bioassay. And plant bioassay have been development and employed not only for the discovery and characterization of the biological activity of plant growth regulators but also have served several important secondary roles. The ideal bioassay should possess the characteristic of high specificity. great sensitivity. short response time, low cost and ease of obtaining plant material. acceptable ease of manipulation, and minimal space and equipment requirements.

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Role of Metal Catalyst and Substrate Site for the Growth of Carbon Nanomaterials

  • Manocha, L.M.;Valand, Jignesh;Manocha, S.
    • Carbon letters
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    • v.6 no.2
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    • pp.79-85
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    • 2005
  • The work reported in this paper relates to preparation and characterization of carbon nanomaterials by CVD method on different substrates by decomposition of certain hydrocarbons at 550-$800^{\circ}C$ using a horizontal quartz tube reactor. Monometallic and bimetallic catalyst system of iron and nickel were used for the preparation of different carbon nanomaterials. The influence of various parameters such as substrate/catalyst preparation parameters, the nature of substrate, catalyst concentration, reaction time and temperature on the growth, yield and alignment of carbon nanotubes has been studied. The characterization of carbon nanomaterials has been carried out using SEM, TEM and TGA. The carbon nanomaterials developed were vertically aligned on a large area of flat quartz substrate.

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