• 제목/요약/키워드: anisotropy field

검색결과 418건 처리시간 0.031초

유전율 이방성이 양인 액정을 이용한 FFS모드의 절연층 두께에 따른 전기 광학 특성 연구 (Study on Electro-Optic Characteristics Dependent on Passivation Layer Thickness in the FFS mode using a Liquid Crystal with Positive Dielectric Anisotropy)

  • 이지연;박상현;오상민;이승희
    • 한국전기전자재료학회:학술대회논문집
    • /
    • 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
    • /
    • pp.485-486
    • /
    • 2005
  • Fringe-field switching mode which has a horizontal and vertical electric field exhibits high transmittance and wide viewing angle characteristics. In the FFS mode, a passivation layer between common and pixel electrodes exists, which functions as preventing current leakage of fringe-field. In this paper, we have studied LC behavior, transmittance and operating voltage characteristics with applied voltage as a function of the passivation layer thickness and defined optimal value of the layer to be about $0.5{\mu}m$.

  • PDF

전기용량법에 의한 자기이방성 측정장치 (A Measurement System for Magnetic Anisotropy with Capacitance Method)

  • 이용호;이연숙;신용돌;문기원;노태환;김희중;강일구
    • 한국자기학회지
    • /
    • 제1권1호
    • /
    • pp.30-36
    • /
    • 1991
  • 전기용량법에 의한 자기이방성 측정장치를 설계 제작하였다. 균이자기장 속에서 원판 또는 구형의 시료가 자기이방성에 의해 받는 토오크를 평행판 축전기의 미소용량 변화로 변환하여, 그것을 변압기 부리지 로 검출하였다. 3% Si-Fe 단결정의(100)면에 대한 입방 이방성 $K_{1}$$3.3{\times}10^{4}\;J/m^{3}$가 얻어졌으며, 교정에는 Ni선의 형상이방성을 이용하였다. 기타 수종의 시료에 대한 결과도 기존치와 좋은 일치를 보였다.

  • PDF

이방성 매질의 기판과 덮개층을 갖는 마이크로스트립 패치 안테나의 방사패턴 (Radiation Pattern in Rectangular Microstrip Patch Antenna with Anisotropy Substrates and Superstrate)

  • 윤중한;이화춘;곽경섭
    • 전기전자학회논문지
    • /
    • 제7권1호
    • /
    • pp.32-42
    • /
    • 2003
  • 본 논문에서는 이방성 매질의 덮개층과 기판을 갖는 사각 마이크로스트립 패치 안테나의 방사패턴을 full-wave approach와 모멘트 계산법을 이용하여 연구하였다. 이방성 매질내의 구성관계식을 통하여 제안된 구조에서의 파수영역 다이애딕 그린 함수를 유도하였으며 이 결과로부터 전계 적분 방정식을 수식화하였다. 갤러킨 모멘트법을 사용하여 전계 적분 방정식을 이산화 하여 전류밀도의 계수를 구한 후에 구좌표계의 원거리 전계는 고정 위상법(stationary phase method)을 이용하여 얻을 수 있다. 전사모의 실험 결과의 타당성을 검증하기 위해서 기존의 결과와 비교하여 일치된 결과를 얻었으며 이방성 덮개층의 두께 변화 그리고 기판과 덮개층의 이방성 비에 따른 방사패턴이 제시되고 분석되었다.

  • PDF

칼코게나이드 박막에서 전계효과에 의한 편광 홀로그래피 회절효율 특성 (The properties of diffraction efficiency in polarization holography using the chalcogenide thin films by the electric field effects.)

  • 장선주;여철호;박정일;정홍배
    • 한국전기전자재료학회논문지
    • /
    • 제13권9호
    • /
    • pp.791-795
    • /
    • 2000
  • Amorphous chalcogenide glasses have a wide variety of light-induced effects. In this study, we have investigated the diffraction efficiency of chalcogenide. As$_{40}$ Ge$_{10}$ Se$_{15}$ S$_{35}$ thin films by the various applied electric fields. The holographic grating in these thin films has been formed using a linearly polarized He-Ne laser light (633nm). The diffraction efficiency was investigated the two method of applied electric field in the perpendicular and parallel to the direction of inducing beam. We obtained that properties of diffraction efficiency in the two methods of applied electric field. The result is shown that the diffraction efficiency of parallel electric field is 285% increase, η=1.1$\times$10$^{-3}$ and the diffraction efficiency of perpendicular electric field is 80% decrease, η=9.83$\times$10$^{-5}$ . Also, we have investigated the anisotropy property on chalcogenide thin films by the electric field effects.

  • PDF

Proton Temperature Anisotropy vs Parallel Beta in the Solar Wind

  • Yoon, Peter H.
    • 천문학회보
    • /
    • 제36권2호
    • /
    • pp.92.2-92.2
    • /
    • 2011
  • In view of the planned NASA's and ESA's Solar Probe Plus and Solar Orbiter missions, respectively, to probe the inner heliosphere and the Sun's corona, it is timely to investigate outstanding problems associated with the solar wind. Among them is the temperature anisotropy problem. As the solar wind expands into the interplanetary space, the density and magnetic field decreases radially, thus leading to temperature anisotropy ($T_{\parallel}{\gg}T_{\perp}$). However, the measured temperature anisotropy can at times be characterized by $T_{\perp}$ > $T_{\parallel}$, while at other times the measured $T_{\parallel}/T_{\perp}$ is much milder than predicted by adiabatic theory. Physical reasons remain poorly understood. This notwithstanding, it is known from plasma physics that for $T_{\perp}$ > $T_{\parallel}$ electromagnetic ion-cyclotron (EMIC) and mirror instabilities are excited, while for $T_{\parallel}$ > $T_{\perp}$, fire-hose instability is excited. By constructing the threshold conditions for various instabilities, one may construct a closure relation that may be useful for modeling the solar wind. In the present paper we discuss theoretical construction of the anisotropy-beta relation by means of quasi-linear theories of these instabilities. The present work complements previous efforts on the basis of linear theory, hybrid simulations, and empirical fits of observations.

  • PDF

속도 이방성 조사를 위한 다방위 역수직 탄성파 현장 실험 (Field Experiment of a Multi-azimuth Inverse VSP for Investigating Velocity Anisotropy)

  • 이두성;김현규
    • 지구물리와물리탐사
    • /
    • 제2권3호
    • /
    • pp.137-141
    • /
    • 1999
  • 다방위 역수직 탄성파 기록을 사용하여 매질의 속도 이방성을 분석하고자 한 개의 시추공 내의 120개 진원으로부터 발생한 탄성파를 지표상의 5개의 측점에서 동시에 기록하였다. 본 실험에서 방위가 다른 측점에서 기록의 초동을 비교하여 속도 이방성을 산출하고자 하였다. 그러한 목적을 달성하기 위해서는 초동을 피킹하기 전에 수진점 정보정이 필요한데, 수진점의 수가 제한적인 역수직 탄성파인 경우는 신뢰할만한 정보정 값을 얻기가 어렵다. 따라서 본 실험에서는 초동을 측정하는 대신에 각 기록의 무브아웃 속도를 산출하고자 하였다. 본 실험에서 각 방위에서, 측정할만한 속도 차이를 발견했으며, 이 속도 이방성은 본 지역에서 과거에 실시된 이방성 연구 결과와 일치함을 확인하였다.

  • PDF

Effect of Shape Magnetic Anisotropy of Amorphous Fe-B-P Nanoparticles on Permeability

  • Lee, Ji Eun;Tsedenbal, Bulgan;Koo, Bon Heun;Huh, Seok Hwan
    • 한국재료학회지
    • /
    • 제30권11호
    • /
    • pp.589-594
    • /
    • 2020
  • Many electronic applications require magnetic materials with high permeability and frequency properties. We improve the magnetic permeability of soft magnetic powder by controlling the shape magnetic anisotropy of the powders and through the preparation of amorphous nanoparticles. For this purpose, the effect of the shape magnetic anisotropy of amorphous Fe-B-P nanoparticles is observed through a magnetic field and the frequency characteristics and permeability of these amorphous nanoparticles are observed. These characteristics are investigated by analyzing the composition of particles, crystal structure, microstructure, magnetic properties, and permeability of particles. The composition, crystal structure, and microstructure of the particles are analyzed using inductively coupled plasma optical emission spectrometry-, X-ray diffraction, scanning electron microscopy and focused ion beam analysis. The saturation magnetization and permeability are measured using a vibrating sample magnetometer and an LCR meter, respectively. It is confirmed that the shape magnetic anisotropy of the particles influences the permeability. Finally, the permeability and frequency characteristics of the amorphous Fe-B-P nanoparticles are improved.

유전율 이방성이 양인 액정을 이용한 프린지 필드 구동형 모드에서 프리틸트각 변화에 따른 전기-광학 특성 (Pretilt Angle Dependent Electro-Optic Characteristics of the Fringe-Field Switching mode using the Liquid Crystal with Positive Dielectric Anisotropy)

  • 정태봉;임영진;안명환;이승희
    • 한국전기전자재료학회논문지
    • /
    • 제17권3호
    • /
    • pp.311-318
    • /
    • 2004
  • We have studied electro-optic characteristics as a function of pretilt angle ($\theta$$_{p}$) in the fringe-field switching (FFS) mode using the LC with positive dielectric anisotropy. When $\theta$$_{p}$ is increased from 0$^{\circ}$ to 20$^{\circ}$, a maximum transmittance and an operating voltage are obviously decreased. In the viewing angle characteristics, the cell with low pretilt angle has a wide region for the contrast ratio greater than 5 and has a best luminance uniformity. Therefore, in the FFS device, a low pretilt angle is favored for high transmittance and wide viewing angle.gle.

Wave propagation in fibre-reinforced anisotropic thermoelastic medium subjected to gravity field

  • Abd-Alla, A.M.;Abo-Dahab, S.M.;Bayones, F.S.
    • Structural Engineering and Mechanics
    • /
    • 제53권2호
    • /
    • pp.277-296
    • /
    • 2015
  • The objective of this paper is to investigate the surface waves in fibre-reinforced anisotropic thermoelastic medium subjected to gravity field. The theory of generalized surface waves has firstly developed and then it has been employed to investigate particular cases of waves, viz., Stoneley waves, Rayleigh waves and Love waves. The analytical expressions for displacement components, force stress and temperature distribution are obtained in the physical domain by using the harmonic vibrations. The wave velocity equations have been obtained in different cases. The numerical results are given and presented graphically in Green-Lindsay and Lord-Shulman theory of thermoelasticity. Comparison was made with the results obtained in the presence and absence of gravity, anisotropy, relaxation times and parameters for fibrereinforced of the material medium. The results indicate that the effect of gravity, anisotropy, relaxation times and parameters for fibre-reinforced of the material medium are very pronounced.