• Title/Summary/Keyword: Chemical structure

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A Study on the Chemical Properties of AZO with Crystal Structure and IGZO of Amorphous Structure Due to the Annealing Temperature (결정질AZO 박막과 비정질IGZO 박막의 결정구조와 결합에너지와의 상관성)

  • So, Young Ho;Song, Jung Ho;Seo, Dong Myung;Oh, Teresa
    • Industry Promotion Research
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    • v.1 no.1
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    • pp.1-6
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    • 2016
  • To research the correlation between the amorphous and crystal structure of oxide semiconductors, AZO and IGZO films were deposited and annealed with various temperatures in a vacuum state. AZO increased the degree of crystal structure with increasing the annealing temperature, but IGZO became an amorphous structure after the annealing process at high temperature. The series of AZO films with various annealing temperatures showed the chemical shift from the analyzer of PL and O 1s spectra, but the results of IGZO films by PL and O 1s spectra were not observed the chemical shift. The binding energy of oxygen vacancy of AZO with a crystal structure was 531.5 eV, and that of IGZO with an amorphous structure was 530 eV as a lower binding energy.

Crystal structure of the epitaxial $BaTiO_{3}$ thin film on the MgO (100) substrate prepared by the coating-pyrolysis process

  • Kim, S.;Kwon, O.Y.;Choi, S.W.;Manabe, T.;Yamaguchi, I.;Kumagai, T.;Mizuta, S.
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.10 no.6
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    • pp.378-380
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    • 2000
  • The epitaxial $BaTiO_{3}$ thin film was prepared on the MgO substrate by the coating-pyrolysis process using a mixed solution of Ba-naphthenate and Ti-naphthenate. The crystal structure of the epitaxial $BaTiO_{3}$ thin film was characterized by XRD ${\theta}/2{\theta}$ scan and asymmetric {303} rocking curve scan. The epitaxial $BaTiO_{3}$ thin film had the cubic phase with the lattice parameter of a = c = 0.4018 nm.

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Preparation of Porous Nanostructures Controlled by Electrospray

  • Nguyen, Dung The;Nah, In Wook;Kim, Kyo-Seon
    • Korean Chemical Engineering Research
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    • v.53 no.5
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    • pp.627-631
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    • 2015
  • Various solid structures were prepared by electrospray technique. In this process, liquid flows out from a capillary nozzle under a high electrical potential and is subjected to an electric field, which causes elongation of the meniscus to form a jet. In our study, by controlling the amount of polyvinyl pyrrolydone in precursor solution, the jet either disrupted into droplets for the formation of spherical particles or was stretched in the electric field for the formation of fibers. During the electrospray process, the ethanol solvent was evaporated and induced the solidification of precursors, forming solid particles. The evaporation of ethanol solvent also enhanced the mass transport of solutes from the inner core to the solid shell, which facilitated fabrication of porous and hollow structure. The network structures were also prepared by heating the collector.

NMR Studies of Metal-binding Luteinizing Hormone Releasing Hormone

  • Won, Ho-Shik
    • Bulletin of the Korean Chemical Society
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    • v.32 no.11
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    • pp.4021-4026
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    • 2011
  • Functions of the luteinizing hormone releasing hormone (LHRH) and its induced release by divalent metal ions have received great attention because this neurotransmitter subsequently regulates the secretion of luteinizing hormone (LH). Metal-LHRH complexes were synthesized by addition of various Cu(II),Ni(II),Zn(II) ions into LHRH in order to understand how the induced release of LHRH is possible. The degree of complexation was monitored by $^1H$, $^{13}C$-NMR chemical shifts, and final products were identified by Mass spectrometry. Solutionstate structure determination of Zn(II)-LHRH out of metal-complexes was accomplished by using NMR and NMR-based distance geometry (DG). Interproton distance information from nuclear Overhauser effect spectroscopy was utilized for structure determination. Structure obtained in this study has a cyclic conformation exhibiting a specific ${\alpha}$-helical turn with residue numbers His[2]-Leu[7] out of 10 amino acids. Comparison of chemical shifts and EPR studies of Ni(II),Cu(II)-LHRH complexes exhibit that these metal complexes have 4-coordination geometry.

Verification of Core/Shell Structure of Poly(glycidyl methacrylate-co-divinyl benzene) Microspheres

  • Jin, Jeong-Min;Choi, Jin-Young;Lee, Kang-Seok;Choe, Soon-Ja
    • Macromolecular Research
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    • v.17 no.5
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    • pp.339-345
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    • 2009
  • The core/shell type structure of the highly crosslinked poly(glycidylmetharylate-co-divinylbenzene) microspheres prepared in the precipitation polymerization in acetonitrile was thoroughly verified by means of swelling, $^1H$ NMR, XPS, TEM and TGA measurements. In the XPS measurement, the higher the GMA content, the higher the oxygen content was observed, implying that the higher content of GMA is observed in the particle surface. The further verification of the core/shell structure of the poly(GMA-co-DVB) particles was carried out using $^1H$ NMR and TEM techniques, resulting in the poly(GMA-co-DVB) particles with the GMA rich-phase and DVB rich-phase. In overall, the poly(GMA-co-DVB) microspheres consist of a highly crosslinked DVB rich-phase in the core and slightly or non-crosslinked GMA rich-phase in the shell part due to the different reaction ratios between two monomers and self-crosslinking density of DVB.

A study on computer-aided synthesis of process control system structure (전산기를 이용한 공정 제어구조 합성에 관한 연구)

  • Lo, Kyun;Yoon, En-Sup
    • 제어로봇시스템학회:학술대회논문집
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    • 1987.10b
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    • pp.670-673
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    • 1987
  • The structure of chemical process has become increasingly complex, due to better management of energy and raw materials. As a consequence, the design of control systems for complete plants now constitutes the focal point of engineering interest, rather than controller designs for single processing units. Instead of traditional methods based on complex mathematical model, chemical processes are represented by structural array and cause-and-effect graph to apply non-numerical problem-solving techniques. A systematic logical procedure to synthesize alternatives of control system structure and some heuristic rules to select a feasible solution from the vast number of alternatives that are possible are considered in this study.

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Synthesis and Structural Analysis of the Diaquabis(ethylenediamine)nickel(II) Bis(p-toluenesulfonate) Monohydrate (Diaquabis(ethylenediamine)nickel(II) Bis(p-toluenesulfonate) Monohydrate 층상 화합물의 합성과 구조 분석)

  • Kim, Chong-Hyeak;Lee, Sueg-Geun
    • Analytical Science and Technology
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    • v.15 no.3
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    • pp.317-320
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    • 2002
  • The layer structure of the title compound, $[Ni(en)_2(H_2O)_2](CH_3C_6H_4SO_3)_2(H_2O)$ (en = ethylenediamine), consists of discrete cations, anions, and solvate water molecules linked by a hydrogen bonding network. The central Ni atom of the cation layer has a slightly distorted octahedral coordination geometry with the ethylenediamine ligands functioning as a N,N'-bidentate and the water ligands bonding through oxygen in a trans arrangement. The p-toluenesulfonate of the anion layer has an alternate sulfonate group directed toward opposite side of the cation layer. This layer structure is stabilized by a hydrogen bond involving the O atoms of the sulfonate, the water ligand, solvate water molecule, and the N atoms of the ethylenediamine.

Bi-layer Gravure Printed Organic Light Emitting Layers with MEH-PPV and Rubrene

  • Kim, A-Ran;Lee, Hye-Mi;Cho, Sung-Min;Chae, Hee-Yeop
    • 한국정보디스플레이학회:학술대회논문집
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    • 2009.10a
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    • pp.1508-1510
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    • 2009
  • In this work, we have compared OLED devices made of blended MEH-PPV/Ruburene mixture and MEH-PPV/Rubrene bi-layer structure devices. The emission layers were made with two different ways - one with gravure printed single layer of blended mixture of MEH-PPV and rubrene, the other with gravure printed bilayers of MEH-PPV and rubrene. Both brightness and efficiency with gravure printed bi-layer devices were higher than blended devices. In this work, we demonstrated that organic bi-layers can be formed with gravure printing technology and higher efficiency can be achieved with bi-layer structure than with blended single layer structure.

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Magnetic Properties of Activated Quartz Nanocomposite

  • N.N., Mofa;T.A., Ketegenov;Z.A., Mansurov;Soh, Hyun-Jun;Soh, Dea-Wha
    • Journal of the Speleological Society of Korea
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    • no.78
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    • pp.9-15
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    • 2007
  • The materials showing high structure dispersion with functional properties were developed on the quartz base and those were obtained by mechano-chemical reaction technology. Depending on the processing conditions and subsequent applications the materials produced by mechano-chemical reaction show concurrently magnetic, dielectric and electrical properties. The obtained magnetic-electrical powders classified by aggregate complex of their features as segnetomagnetics, containing a dielectric material as a carrying nucleus, particularly the quartz on that surface one or more layers of different compounds were synthesized having thickness up to 1050nm showing magnetic, electrical properties and others. The similarity of the structure of surface layers of quartz particles subjected to mechano-chemical processing and nano-structure cluspol (clusters in a polymer matrics) material was alsoconfirmed by the fact that the characteristics of ferromagnetic quartz of insulating nano-composite powder were changed with time, after its preparing process was completed.