• 제목/요약/키워드: polarization phenomena

검색결과 70건 처리시간 0.031초

Deriving Physical Quantity for Measurement of Atmospheric Polarization and Its Correlation with Air Pollutants (대기 편광 측정을 위한 물리량 도출 및 대기 오염 물질과의 상관관계)

  • Park, Hyogun;Yoon, Hyeongsu;Kim, Eunji;Kang, Dongil
    • Journal of the Korean earth science society
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    • 제34권3호
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    • pp.249-256
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    • 2013
  • For the purpose of recording polarization of the earth's atmosphere, the entire sky was photographed using the all-sky camera when the Sun was just above the horizon. The ratio and width of polarization were defined using the photograph, and a method to measure them was developed. Time-series photography of the polarization ratio and its width enabled us to qualitatively analyze the polarization phenomena which changes depending on the weather conditions. Findings indicated that polarization was co-related with air pollutants in a meaningful way. The polarization phenomena of the Earth's atmosphere are influenced by air pollutants. The more air pollutants exist in the air, the lower polarization ratio and the bigger polarization width it has. It is suggested that air pollutants disperses more photons, which makes it possible to observe the polarization phenomena in the vast area of the sky.

Depth-resolved Stokes parameters of light backscattered from turbid media with polarization-sensitive optical coherence tomography system and successive phase-shifting algorithm (위상천이원리 와 PS-OCT시스템을 적용한 역산란광의 매질 깊이별 스톡스변수 추출)

  • Oh, Jung-Taek;Kim, Seung-Woo
    • Proceedings of the Optical Society of Korea Conference
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    • 한국광학회 2003년도 제14회 정기총회 및 03년 동계학술발표회
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    • pp.286-287
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    • 2003
  • Polarization-sensitive optical coherence tomography (PS-OCT) was developed to image highly scattering tissues with accounting for polarization effects in the sample. These polarization-sensitive images can provide additional information on the structure of the tissue because of a polarization state of the light is changed at its interaction with biological tissues. The scattering and birefringence are two phenomena, which change the polarization state of light passing through medium. (omitted)

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Concentration Polarization Phenomena in Ion-Exchange Membranes (이온교환막에서의 농도분극 현상)

  • 최재환;문승현
    • Membrane Journal
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    • 제12권3호
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    • pp.143-150
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    • 2002
  • Electrodialysis(ED) is a reliable and effective process for the separation and concentration of ionic compounds. However, commercial uses of ED are often hindered by the cost of the stack that mainly resulted from the ion-exchange membrane cost. In order to minimize the membrane cost, it is desired to operate ED at the highest practicable current density. In an actual ED system the high current operation is limited by the concentration polarization phenomenon. This article illustrates the transport phenomena of ions through ion exchange membranes using current-voltage relations as a characterizing method. Also recent studies on electroconvection and water-spitting phenomena caused by concentration polarization were reviewed.

Diffraction Anomalies on the Periodic Strip Grating over a Grounded Dielectric Layer in Case of Oblique Incidence and Arbitrary Polarization (임의의 편파로서 비스듬한 각도로 입사하는 전자파의 경우에 대한 접지된 유전체층 위에 놓여있는 주기적인 스트립격자 구조에서의 특이한 회절현상)

  • 조웅희;고지환;조영기
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • 제9권2호
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    • pp.238-252
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    • 1998
  • Diffraction anomalies in the periodic strip grating over a grounded dielectric layer are investigated for the plane wave incidence case of both arbitrary(oblique) incidence angle and arbitrary polarization by use of the spectral domain method combined with the sampling theorem. Some numerical results for the Bragg and Off-Bragg blazing phenomena for the cases of arbitrary incidence angle and polarization as well as TE and TM polarization are presented along with discussions on those phenomena.

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Probing and Control of Surface Polarization Phenomena in Molecular Films for Organic Electronics

  • Iwamoto, Mitsumasa
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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    • pp.3-4
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    • 2007
  • Orientational ordering of polar molecules and excess charges at the interface are main origins of surface polarization. For organic electronics, probing and control of these two surface polarization phenomena are key issues. In this presentation, I report a novel electrical measurement that can directly probe orientational dipolar motion in surface monolayers by Maxwell-displacement-current, and also report a novel optical technique that allows carrier motions in organic materials by measuring the optical second harmonic signals activated by the electric field. Then I discuss how the control of dipolar motions and carrier motions are linked to organic electronics applications such as organic field effect transistors.

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Polarization Holographic Grating Formation and Diffraction Efficiency Measurement in Amorphous Chalcogenide Thin Films (비정질 칼코게나이드 박막에서의 편광 홀로그라피 격자 형성 및 회절효율 측정)

  • 전진영;여철호;이현용;정홍배
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 한국전기전자재료학회 1998년도 추계학술대회 논문집
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    • pp.89-92
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    • 1998
  • Amorphous chalcogenide thin films, especially a-(Se, S) based films, exhibit a number of photoinduced phenomena not observed in other types of amorphous thin films. The polarization holographic grating has been formed in amorphous As-Ge-Se-S thin films using two linearly polarized He-Ne laser light. In addition, dffraction efficiency has been measured by the same laser of a relative lower intensity at the same time.

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The Measurement on Diffraction Efficiency in Polarization Holography using Amorphous Chalcogenide Thin Films (칼코게나이드 박막을 이용한 편광 홀로그래픽의 회절효율 측정)

  • 장선주;여철호;이현용;정홍배
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 한국전기전자재료학회 1999년도 춘계학술대회 논문집
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    • pp.87-90
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    • 1999
  • The dependence of diffraction efficiency as a funct~on of film thickness and incident angle has been investigated in amorphous chalcogenide thin films, which act as a polarization holographic materials. Especially a-(Se, S) based films exhibit a number of photoinduced phenomena not observed in other types of amorphous thin films. Holographic gratings in amorphous As-Ge-Se-S thin films have been formed using the mutual perpendicular polarized(linearly) He-Ne laser light. We could obtain the optimum condition to get high diffraction efficiency.

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Electromagnetic Scattering Resonances on a Periodic Strip Grating on a Grounded Dielectric Slab: Bragg Blazing Phenomena of TM Polarization Case (접지된 유전체 슬랩 위에 위치한 주기적인 스트립 격자구조에서의 전자기적 산란공진;TM편파 경우의 Bragg Blazing 현상)

  • 조웅희;홍재표;김종규;조영기
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • 제11권8호
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    • pp.1363-1375
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    • 2000
  • The electromagnetic scattering characteristics by a periodic strip grating on a grounded dielectric slab for TM polarization case are examined from the viewpoints of both the reflection grating and the leaky wave antenna problems. Numerical results far two kinds of Bragg blazing (resonance type and non-resonance type) phenomena are given and some discussions on the properties(complex propagation constants, scattering characteristics, and distributions of strip current density) are presented. The comparison of the Bragg blazing phenomena between TM and TE polarization cases are also given in detail.

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Extended Maxwell-Wagner Polarization Model with Onsager Theory for the Electrorheological Phenomena (전기유변현상 해석을 위하여 Onsager 이론으로 확장한 Maxwell-Wagner 분극 모델)

  • Kim, Young Dae
    • Korean Chemical Engineering Research
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    • 제56권5호
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    • pp.767-772
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    • 2018
  • Among various mechanisms for ER phenomena, the electrostatic polarization and conduction models were known as the most promising theoretical models. However, many inherited defects have limited their uses for the development of effective ER fluids. To resolve these problems, extended Maxwell-Wagner polarization model with Onsager theory was developed. It was observed that the extended model resolved the problems, suggesting that the extended model can be used for the development of effect ER fluids.

Electromagnetic Scattering Resonances on a Periodic Strip Grating on a Grounded Dielectric Slab: Bragg Blazing Phenomena of TE Polarization Case (접지된 유전체 슬랩 위에 위치한 주기적인 스트립 격자 구조에서의 전자기적 산란공진: TE 편파 경우의 Bragg Blazing 현상)

  • 조웅희;홍재표;조영기
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • 제10권4호
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    • pp.594-606
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    • 1999
  • The electromagnetic scattering characteristics by a periodic strip grating on a grounded dielectric slab for TE polarization case is examined from the viewpoints of both the reflection grating and the leaky wave antenna problems. Numerical results for two kinds of Bragg blazing (resonance type and non-resonance type) phenomena are given and some discussions on the properties such as complex propagation constants, scattering characteristics, and distributions of strip current density are presented.

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