• Title/Summary/Keyword: $BaTiO_{3}$

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The Structural and Electrical Properties of the BST Thin Film Prepared by Sol-Gel method. (Sol-Gel법으로 제조한 BST 박막의 구조 및 전기적 특성)

  • Kim, Kyoung-Duk;Chung, Jang-Ho;Bae, Seon-Gi;Lee, Young-Hie
    • Proceedings of the KIEE Conference
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    • 1997.11a
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    • pp.291-293
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    • 1997
  • In this study, Sol-Gel derived $(Ba_{0.7}Sr_{0.3})TiO_3$ thin films were fabricated and investigated. The stock solution was synthesized and spin-coated on Pt/Ti/$SiO_2$/Si substrate at 4000(rpm] and then, annealed at $650{\sim}750[^{\circ}C]$. Crystallization condition, microstructural properties and interfacial structure were observed by XRD, AFM, SEM and TEM. It was found that the BST thin films were completely crystallized at 750[$^{\circ}C$] and showed nano-sized grains. The dielectric constant and loss of the BST thin films were 220, 0.01 at 1[kHz] respectively. Increasing the temperature, the dielectric constant and loss characteristics were not varied widely. At the applied voltage of 1.5[V], the leakage current density was under the $10^{-9}[A/cm^2]$.

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Alteration of Physical Properties of Nanoparticle Embedded liquid Crystal Causing the Enhancement of the Performance of LCDs

  • Kobayashi, Shunsuke;Kineri, Tohru;Takatoh, Kohki;Akimoto, Mitsuhiro;Hoshi, Hajime;Nishida, Naoto;Toshima, Naoki;Sano, Satoru
    • 한국정보디스플레이학회:학술대회논문집
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    • 2008.10a
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    • pp.1473-1476
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    • 2008
  • Doping the nanoparticles of Pd, p-$BaTiO_3$, $SiO_2$ and MgO into LCs alters their physical properties such as $K_{ii}$, $\Delta\varepsilon$, ${\Delta}n$, $\gamma_1$ and $T_{NI}$. Except for $K_{33}$, all these parameters decreases and thus bring the reduction of operating voltage and/or response times.

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Characterization and Potent Application of Pleurotus floridanus Trypsin Inhibitor (PfTI)

  • Pannippara, Manzur Ali;Kesav, Sapna;Raghavan, Rekha Mol Kollakal Naduvil;Mathew, Abraham;Bhat, Sarita Ganapathy;Kozhiyil, Elyas Kothanan
    • Natural Product Sciences
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    • v.26 no.3
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    • pp.207-213
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    • 2020
  • Characterization and in vitro inhibition studies of protease inhibitor from the mushroom Pleurotus floridanus (PfTI) towards the pest Papilio demoleus is studied. The addition of 1 mM Mn2+, Na2+, Ba2+ and Ni 2+ enhanced the PfTI activity. The ICP-atomic emission spectrum showed the presence of Ca2+, Mg2+ and Zn2+ in the PfTI. Surfactants SDS and CTAB at a concentration of 1% reduced the PfTI activity whereas, the nonionic detergents Triton X and Tween 80 increased the activity. The inhibitory activity gradually decreased with increase in concentration of DMSO and H2O2. The activity was increased by dithiothreitol up to a concentration of 80 μM and inactivated at 140 μM. The activity of PMSF modified PfTI was drastically reduced to 0.234 U/mL at 4 mM concentration and similar results were obtained for modification of cysteine by N-Ethylmaleimide at slightly higher concentrations. The complex of trypsin and PfTI showed complete loss in fluorescence intensity at 343 nm compared with control. In vitro inhibition studies of PfTI with midgut proteases isolated from citrus pest P. demoleus with protease activity of 1.236 U was decreased to 0.613 U by 50 μL (0.1 mg/mL) of the inhibitor. Inhibitor was stable up to 0.04 M concentration of HCl.

Geochemical Dispersion and Enrichment of Fluvial Sediments Depending on the Particla Size Distribution (입도분포에 따른 하상퇴적물의 지구화학적 분산 및 부화)

  • 이현구
    • Economic and Environmental Geology
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    • v.32 no.3
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    • pp.247-260
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    • 1999
  • Geochermical characteristics of the fluvial sediments deprnding on particle size distribution size were investigated in the respect of majir, minor and rare eath element chemisitry. Ratios of $Al_{2}O_{3}/Na_{2}O$ and $K_{2}O/Na_{2}O$ of the sediments show the homogeneous valus, and partly positive correlation with $SiO_{2}/Al_{2}O_{3}$, respecively. Characteristics of minor element ratios (V/Ni, Cr/V, Ni/Co and Zr/Hf)are within the lower and narrow range. Thesesuggested that sediment sources may be acidic to intermediate granitic rock, and may be explained by simple weathering and sedimentation. With increasing SiO2 contents, concentrations of $Al_{2}O_{3}$, $Fe_{2}O_{3}$, CaO and MgO decreased, but those of $K_{2}O$ and $Na_{2}O$ increased, Concentrations of Ba, Be, Cs, Cu, Li, Ni, Sr, V and Zr show comparatively normal negative and some positive trends. Compared with the mean composition of granite, concentrations of $Al_{2}O_{3}$, $Fe_{2}O_{3}$, MnO, CaO and MgO in the sediments of the study area were highly enriced. Among some minor and rare earth elements, concentrations of As, Cd, Cu, and V were enriched, but those of Be, Ce, Rb, Sc, Sr and Zn were depleted when compared with average composition of granite. By decreasing of particle size fractions, SiO2, Rb and Sr conterts decreased, but concentrations of $Al_{2}O_{3}$, $Fe_{2}O_{3}$, CaO, MgO, $TiO_{2}$, MgO, $P_{2}O_{5}$, Be, Cu, Hf, Pb, V and Zr increased. From the correlations between particle size fractions and element concenreations, some elements of $Fe_{2}O_{3}$, CaO, MgO, $P_{2}O_{5}$, Cu, Ni, Zn and Zr showed typical trends in the secondary contramination sediments. These trends are typically shown under 100 mesh fractions. It indicates that the fraction of minus 100 mesh is the optimum size fraction for geochemical and environmental survey.

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Electrical and Optical Property of Powder Electroluminescent device at Dielectric variety (절연체 종류에 따른 후막 전계 발광소자의 광학 및 전기적 특성)

  • Oh, Joo-Youl;Lee, Jong-Chan;Park, Dae-Hee
    • Proceedings of the KIEE Conference
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    • 1999.07d
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    • pp.1800-1802
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    • 1999
  • Electroluminescence is occurred when phosphor is located in electric field. In this paper, we made powder electroluminescent device (PELD) with structured ITO film/phosphor/Insulator/silver paste. The transparent electrode was ITO film and green(2704-01) and orange(2702-02) and blue-green(2703-01) were used as phosphor. The insulator was $BaTiO_3$ and $Y_2O_3$, back electrode was silver paste. To investigate electrical and optical properties of PELDs, EL spectrum, Brightness, Transferred charge density using Sawyer-Towers circuit was measured.

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Light modulation properties of the penferroelectric BLN-PZT ceramics (준강유전 BLZ-PZT 세라믹의 광변조특성)

  • 류기원;정장호;박인길;이영희
    • Electrical & Electronic Materials
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    • v.6 no.5
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    • pp.454-460
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    • 1993
  • 본 연구에서는 준강유전 특성을 갖는 xBa(L $a_{1}$2/N $b_{1}$2/) $O_{3}$- (1-x)Pb(Z $r_{y}$ $Ti_{1-y}$) $O_{3}$ (x=8.5, 9.0[mol.%], y=65, 70[mol.%]) 세라믹을 2단 소성법으로 제작한 후, 조성 및 인가전계에 따른 전기광학 특성 및 광변조 특성을 측정하였다. 인가전계가 증가함에 따라 8.5/65/35 시편을 제외한 전조성에서 유효복굴절이 2차 함수적으로 변화하는 2차 전기광학 특성을 나타내었으며 2차 전기광학계수, 반파장전압 및 ON-OFF ratio는 9.0/65/35 시편에서 각각 6.17x$10^{-16}$[ $m^{2}$/ $v^{2}$], 136[V], 252의 가장 우수한 값을 나타내었다. 9.0/70/30, 9.0/65/35 및 8.5/70/30 시편에 대해 광변조 특성을 측정한 결과, 입사광의 세기를 인가전압에 의해 변조시킬 수 있음을 관찰하였다.다.

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Transferred charge density and Optical Property on Powder Electroluminescent device (후막 EL 소자의 광학 및 이동전하밀도 특성)

  • 오주열;이종찬;박대희
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1999.05a
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    • pp.286-290
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    • 1999
  • Electroluminescence is occurred when phosphor is located in electric field. In this paper, we made powder electroluminescent device (PELD) with structured ITO film/Phosphor/Insulator/Silver paste. The transparent electrode was ITO film and green(2704-01), orange(2702-02) and blue-green(2703-01) were used as phosphor. The insulator was BaTiO$_3$ and $Y_2$O$_3$, back electrode was silver paste. To investigate electrical and optical properties of PELDs, EL spectrum, Brightness, Transferred charge density using Sawyer-Tower\`s circuit was measured.

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Elemental Analysis in Astragali Radix by Using ICP-AES and Determination of the Original Agricultural Place of Oriental Medicine by Using a Chemometrics (ICP-AES를 이용한 황기 속에 함유된 원소의 성분 분석과 Chemometrics를 이용한 한약재의 원산지 규명)

  • Kang, Mi Ra;Lee, Ick Hee;Jun, Hyuong;Kim, Yongseong;Lee, Sang Chun
    • Analytical Science and Technology
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    • v.14 no.4
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    • pp.311-316
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    • 2001
  • We have investigated the trace amount in an oriental medicine in oder to determine the geographical origin by using inductively coupled plasma-atomic emission spectrometry(ICP-AES) and chemometric anlysis with principal component analysis(PCA) and pattern recognition. Astragali Radix from several agricultural places in Korea was selected as an example of the oriental medicine and analyzed by ICP-AES. The dried Astragali Radix sample was treated with $HNO_3$ and $H_2O_2$, then digested using microwave oven. Elements such as Mg, Al, K, Ca, Ti, Mn, Fe, Cu, Zn, and Ba with different concentrations were found an used for the identification of the origin of agriculture places. Especially, the concentration of Al, Fe, Zn and Ti were employed to investigate the relationship between. Astragali Radix and the agricultural places by PCA and pattern recognition. We have made a program that is based on chemometrics in analytical spectroscopy. The results of the chemometrics analysis indicated that a distinction among Yechon and Chechon, Chungson, Kurye and Chinese Astragali Radix could be made. We believe that principal component analysis(PCA) and pattern recognition is a valuable tool to identify the origin of Astragali Radix in terms of the agricultural place.

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Preparation and crystallization of non-alkali multicomponent glasses for thick-film insulators (후막회로 절연용 다성분계 무알카리 유리의 제조 및 결정화 특성)

  • 이헌수;손명모;박희찬
    • Electrical & Electronic Materials
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    • v.8 no.1
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    • pp.95-101
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    • 1995
  • Crystallizable glasses with precipitation of celsian, anorthite, wollastonite and gahnite were prepared for the purpose of insulating dielectric layers in devices such as integrated circuit substrates. The starting glasses were prepared by melting the batches for 1 hour at 1450.deg. C and then Quenching to a distilled water. And crystallization behavior of these glasses were studied by DTA, TMA, XRD analysis and by the measurement of dielectric properties. The overall composition of the glass-ceramic consists in weight percent of 30-35% A1$_{2}$O$_{3}$, 13-26% BaO, 5-21% CaO, 10-24% ZnO, 4.5-9.0% TiO$_{2}$ and 4-8% B$_{2}$O$_{3}$. As a result, in barium-rich glasses only celsian phase was developed in the range of 850-900.deg. C. Also, the thermal expansion coefficient, dielectric constant and quality factor of these glass-ceramics were 68*10$^{-7}$ /.deg. C, about 9 and more than 1000, respectively.

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A temperature stable bandpass filter using dieletric-filled stepped impedance resonators (접합된 Stepped impedance resonator를 이용한 온도보상형 유전체 대역통과 필터)

  • Lim, Sang-Kyu;Kim, Jun-Chul;Kim, Duck-Hwan;Ha, Jong-Su;Oh, Chang-Heon;Sim, Hwa-Sup;An, Chul
    • Journal of the Korean Institute of Telematics and Electronics D
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    • v.35D no.2
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    • pp.78-85
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    • 1998
  • The design method of a temperature stable bandpass filter using dielectric coaxial resonators of with two dielectric ceramics with opposite signs of temperature coefficient of dielectric constant (${\tau}_{\epsilon}$) to compensate for each other in this method. $MgTiO_3$(${\tau}_{\epsilon}$=+99 ppm/${\circ}C$) as a positive ${\tau}_{\epsilon}$ material and Ba($Zn_{1/3}Nb_{2/3}$)$O_3$(${\tau}_{\epsilon}$=-77ppm/${\circ}C$) as a negative material were selected. The length of a SIR for the temperature stability was calculated according to the design method and the susceptance slope parameter of the SIR was obtained. A temperature stable bandpass filter using dielectric SIR's was designed, simulated and fabricated. The center frequency of this filter was 915 MHz and the pass bandwidth was 20 MHz. Temperature properties of this bandpass filter by simulations were compared with the measured results of the bandpass filter fabricated.

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