• Title/Summary/Keyword: Dipole moment

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$\pi$-A properties of phospholipid monolayers by Maxwell-displacement-current-measuring technique (변위전류법에 의한 지질 단분자막의 $\pi$-A특성)

  • 이경섭;전동규;권영수;국상훈
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1995.05a
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    • pp.120-123
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    • 1995
  • Maxwell-Displacement-Currnt-Measuring Technique(MDCM) is a simple system for displacement current measuring which consist with two electrodes to the electrometer, With this method, the displacement current flow only when the electric flux density change by the displacement of molecules or charge particles of membrance on the water surface. Thus, It is Possible to detect dynamic behavior of molecules of membrane without any electrical contact with molecule membrane. In this paper, We measure surface pressure, displacement current and dipole moment of phospholipid monolayers on the wafer surface with applied pressure by MDCM and We measured DTA(differential thermal analysis).

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The Effect of Binder Burnout Time and Heating Rate on the Electrical Properties of Multilayer Ceramic Capacitors (소결과정에 있어서 Bindex Burnout 온도 및 소결온도까지의 가열속도가 MLC의 전기적 특성에 미치는 영향)

  • 김호기;오창섭;김용혁
    • Journal of the Korean Ceramic Society
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    • v.24 no.3
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    • pp.207-214
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    • 1987
  • This paper is to determine the effect of binder burnout time and heating rate on the electrical propertries of type II multilayer ceramic capacitors(MLC). The quality of multilayer ceramic capacitor depends suitable on the binder burnout time, which is determined for at least 24 hours in the PVB-binder system. It is suggested that theelectrical properties of multilayer ceramic capacitor is due to the control of heating rate, with the dipole moment density from grain size distributiion. Comparing the fast firing with slow, we observed a small but consistent improvement in the electrical properties.

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A Study on the Molecular Orientation and the Surface Mophology of polyimide precursor ultrathin film (폴리이미드 전구체 초박막의 분자배향과 표면상태에 관한 연구)

  • Jeong, Soon-Wook
    • Journal of the Korean Applied Science and Technology
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    • v.22 no.3
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    • pp.228-233
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    • 2005
  • Langmuir-Blodgett(LB) technique can speak the best candidate of the future molecular electronic devices. But, precursor as molecular ultrathin film devices require the bulk property that are influenced by the molecular orientation. So, this device is one of current interest in molecular electronic device development of new materials. In this study, quantitative evaluation of molecular orientation in LB films of polyamic acid alkylamine salt was performed analysis experiment comparing the absorption or transmission intensity of the FT-IR spectrometer and reflection or absorption spectra with UV-visible absorption spectra. It could find that the polar angle(${\theta}$) of the dipole moment appears in about $68^{\circ}$ and the tilting angle of the alkyl chain is about $11.5^{\circ}$.

A Study on the Molecular Orientation of Po1yamic Acid Alkylamine Salt Langmuir-Blodgett Films (Polyamic Acid 알킬아민 염 랭뮤어-블로젯막의 분자 배향에 관한 연구)

  • 정순욱;임현성
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2000.11a
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    • pp.53.1-56
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    • 2000
  • Langmuir-Blodgett(LB) technique is the best candidate for the future molecular electronic devices. But, these molecular thin film devices require the bulk properties that are influenced by the molecular orientations. So, this is of current interest in molecular electronic device fabrications of new materials. In this study, quantitative evaluation of molecular orientation in LB films of PAAS was performed by comparing the absorption intensities of the FT-IR transmission and reflection-absorption spectra and the polarized UV/visible absorption spectra. It was found that the polar angle($\theta$) of the dipole moment is about 68$^{\circ}$and the tilting angle of the alkyl chain is about $11.5^{\circ}$ .

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Studies on The Influence of The Polarity of The Spreading Solvent on The Properties of The Polymer Monolayers on The Water Surface (분산용매의 극성 변화가 수면 위 고분자 단층막의 성질에 미치는 영향에 관한 연구)

  • Suh, Hye-Ran;Kim, Eu-Gene
    • Journal of the Korean Applied Science and Technology
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    • v.17 no.1
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    • pp.23-28
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    • 2000
  • The influence of the polarity of the spreading solvent on the properties of the monolayer of poly(styrene-co-acrylonitrile)'s with various acrylonitrile contents was studied. The surface pressure - area isotherm and the apparent dipole moment - area isotherm were obtained and analyzed when the mixtures of methylene chloride and N-N-dimethylformamide used as spreading solvent. The isotherms were strongly influenced by the polarity of the solvent.

A Study on Stimulus reaction and Physical Properties of PBDG (PBDG의 자격반응과 물성에 관한 연구)

  • Chang, Hun;Lee, Kyung-Sup
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.07a
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    • pp.1047-1049
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    • 2001
  • The displacemant current measuring system used for detecting the dynamic behavior of monolayers at the air-water interface is described. It basically consists of a film balance, a pair of electrodes connected to each other through a sensitive ammeter. Here, one electrode is suspended in air and the other electrode is placed in the water. With Maxwell-displacement-current-measuring method, the phase transitions of Poly-${\gamma}$ -benzyl D-glutamate(PBDG) on a water surface were detected. Measured surface pressure, displacement current and dipole moment of monolayers of PBDG on the water surface. We measured analyzed displacement current that occur when differed temperature. Could know that displacement current is proportional in increase of temperature and great as experiment result.

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Theoretical Study of the Nonlinear Optical Properties of Aromatic Heterocyclic Polymers (아로메틱 헤테로고리 폴리머의 비선형 광학적 성질에 대한 이론적 연구)

  • 박춘배;송성익;송민종;김현주;최우성
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1993.11a
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    • pp.90-92
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    • 1993
  • PM3 semiempirical calculations ions have performed on the three aromatic heterocyclic polymers. The dipole moment (${\mu}$7), static 1st-orders(${\alpha}$), 2nd-order (${\beta}$), and 3rd-order polarizabilities(${\gamma}$) were investigated to study the nonlinear optical properties of the polythiophene, polyfuran, and polypyrrole systems. As a function of n, ${\alpha}$ and ${\gamma}$ increases much more rapidly for the polythiophene systems than for the polyfuran and Polypyrrole systems due to the pi-electron delocalization.

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Performance Analysis of Magnetic Torquer for Spacecraft Control

  • Lee, Seon-Ho;Seo, Hyun-Ho;Rhee, Seung-Wu
    • 제어로봇시스템학회:학술대회논문집
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    • 2005.06a
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    • pp.1313-1317
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    • 2005
  • This paper presents the overall design, manufacture, and test result of the high capacity (more than 150 Am^2) magnetic torquer for the use of satellite control. To provide an electrical current to the magnetic torquer, the driving electronics is also constructed. The integration and test of the magnetic torquer and its driving electronics are performed via the magnetic field measurement according to the distance and the magnetic torque measurement with torque-meter. To compare the performance obtained from the test results we also perform computer simulation with three-dimensional model.

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A study on the radiation pattern analysis of the monopole antenna mounted on a portable phone (휴대전화기에 장착된 모노폴안테나의 방사패턴 해석에 관한 연구)

  • 정옥현;문영찬;윤상원;장익수
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.33A no.12
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    • pp.16-24
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    • 1996
  • In this paper, the radiation pattern of the monopole antenna mounted on the portable phone is analyzed. The analyzed model consists of a rectangular conductor box and a monopole antenna. Even though the radiation pattern of the monopole has been well known, the monopole antenna mounted on the portable phone has not been fully studied. Because of the conductor box, portable phone acts as an unbalanced dipole antenna whoe radiation patterns deviate fro those of th econventional isolated monopole antenna. Therefore, the analysis of the radiation patterns of unbalanced dopole antenna is necessary. Using the moment method, its radiation patterns are analyzed and the numerical results are verified through the measurements. In addition, the radiation patterns depending on various length of the conductor box and the monopole antenna are also presented and the dimension of the portable phone which gives excellent radiation characteristics are derived from the analyzed results.

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Sensing Properties of Porous Silicon Layer for Organic Vapors (다공질 실리콘의 유기가스 검지 특성)

  • 김성진;이상훈;최복길
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.15 no.11
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    • pp.963-968
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    • 2002
  • In this work, porous silicon (PS) layer is investigated as a sensing material to detect organic vapors such as ethanol (called alcohol), methanol, and acetone in low concentrations. To do this, PS sensors were fabricated. They have a membrane structure and comb-type electrodes were used to detect the change of electrical resistance effectively. PS layer on Si substrates was formed by anodization in HF solution of 25%. From fabricated sensors, current-voltage (Ⅰ-Ⅴ) curves were measured for gases evaporated from 0.1 to 0.5% organic solution concentrations at 36$\^{C}$. As the result, all curves showed rectifying behavior due to a diode structure between Si and the PS layer. The conductance of most sensors increased largely at high voltage of 5V, but the built-in potential on the measured Ⅰ-Ⅴ curve was lowered inversely by the adsorption effect of the organic vapors with high dipole moment.