• Title/Summary/Keyword: Dipole

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Cooperative Spontaneous Emission from Nanocrystals to a Surface Plasmon Polariton in a Metallic Nanowire

  • Lee, Joong-Hag;Hong, Suc-Kyoung;Nam, Seog-Woo;Kim, Seog-Seong
    • Journal of the Optical Society of Korea
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    • v.15 no.4
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    • pp.407-414
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    • 2011
  • We analyze the cooperative spontaneous emission of optically excited nanocrystals into surface plasmon polaritons propagating on the surface of a cylindrical metallic nanowire. The spontaneous emission probability of the nanocrystals is obtained by perturbative expansions with and without dipole-dipole interaction among nanocrystals in order to see the cooperative effects. The spontaneous emission probability depends on the radial and axial distributions, as well as on the dipolar orientation of nanocrystals. It is shown that the spontaneous emission probability is strongly influenced by dipole-dipole interaction, axial distribution, and dipolar orientation of nanocrystals for closely spaced nanocrystals.

An analysis of Center-Fed Planar Dipole Antenna by method of moments (모멘트 방법에 의한 중앙급전식 평판 다이폴 안테나의 해석)

  • Yang, Sang-Yong;Lee, Tack-Kyung;Ra, Jung-Woong;Lee, Soo-Young
    • Proceedings of the KIEE Conference
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    • 1989.07a
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    • pp.647-650
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    • 1989
  • The driving-point impedance of the center-fed planar dipole antenna is obtained using the method of moments (MOM). For the thin dipole antenna, our numerical result is compared with that of the inverse method by D. R. Rhodes as well as the known solutions of equivalent wire antenna. For the frequencies of L-band and S-band, the driving-point impedances of the thick planar dipole antennas are measured by experiment and compared with the numerical results.

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Scattering from a Periodic Array of Duble-Dipole Elements over a Grounded Dielectric Slab

  • Ko, Jin-Whan
    • ETRI Journal
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    • v.20 no.1
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    • pp.46-54
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    • 1998
  • An analysis method of electromagnetic scattering from periodic patch array of double-dipole elements on a grounded dielectric substrate in case of oblique incident and arbitrary polarization is considered. The basis functions are chosen to be entire consinusoidal functions are chosen to be entire consinusoidal functions covering the rectangular shaped domain in which the original dipoles are inscribed, unlike the conventional method in which basis functions are defined only for the conducting element region. To confirm the validity of the proposed analysis method, we calculate the normalized scattered power for two propagating modes and compare the results with those obtained by the previous numerical method for the double dipole elements of rectangular type and parallelogram type which have the property of frequency scanned reflection and polarizer. Good correspondence has been observed between them. Some numerical results such as variation of power and axial ratio of first-order diffracted wave by a periodic array of double-dipole elements are compared with previous results.

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Calculation of the Dipole Moments for Simple Molecules by the Expansion Method for Spherical Harmonics (Spherical Harmonics의 전개방법에 의한 간단한 분자의 쌍극자모멘트의 계산)

  • Ahn Sang Woon;Park, Byeong Bin
    • Journal of the Korean Chemical Society
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    • v.22 no.6
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    • pp.357-364
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    • 1978
  • The dipole moments for $NH_3$, HF, CO, HCHO, HCN, PO, $PO^-\;and\;H_2O$ molecules are calculated, using the method for evaluation of the dipole moment matrix elements by the expansion method for spherical harmonics. The calculated dipole moments in this work are closer to the experimental values than those of the other work.

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Two-Dimensional Inversion for Dipole-Dipole Resistivity Data (쌍극자 비저항 데이타에 대한 2차원 역해석)

  • Kim, Hee Joon;Kim, Younghwa
    • Economic and Environmental Geology
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    • v.21 no.1
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    • pp.107-113
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    • 1988
  • We present a precedure for interpreting dipole-dipole apparent resistivity data. The procedure is constructed by combining a forward two-dimensional finite element modeling and an inverse technique with Householder's transformation. In the interpretation, subsurface structure is divided into some blocks with constant resistivities. Our inversion technique is tested on synthetic and field data. We found that geologic constraint is required for successful interpretation.

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Experimentally Measured Rotational Reorientation Time of Coumarin 6 Laser Dye in Ethanol and Acetonitrile Solvents

  • Renuka, C.G.;Raikar, U.S.
    • Journal of Photoscience
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    • v.12 no.3
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    • pp.119-122
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    • 2005
  • The photophysical properties of coumarin 6 laser dye have been studied in two solvents; ethanol and acetonitrile using steady-state fluorescence depolarization technique. The experimentally measured reorientation time of coumarin 6 is more or less the same in given solvents at particular temperature. It is found that coumarin 6 rotates slower in acetonitrile than in ethanol especially at higher values of viscosity over temperature. We also measure the ground and excited state dipole moments of coumarin 6 by solvent perturbation method. The results found that excited state dipole moment is greater than ground state dipole moment, which indicates that excited state is more polar than the ground state.

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Calculation of the Dipole Moments for Trigonal Bipyramidal Complexes (Trigonal Bipyramid 구조를 갖는 착물의 쌍극자모멘트의 계산)

  • Sangwoon Ahn;Ja Hong Kim;Kee Hag Lee;Gap Choul Shin
    • Journal of the Korean Chemical Society
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    • v.26 no.1
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    • pp.18-23
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    • 1982
  • A new method for calculation of the the dipole moments for trigonal bipyramidal complexes has been developed in this work. Illustrative calculations are performed on a few trigonal bipyramidal complexes with the approximate molecular orbital and the valence bond method. The calculated values of the dipole moments by the approximate molecular orbital method are very close to the experimental values. The calculated dipole moments may be used to predict the geometric structure of trigonal bipyramidal complexes.

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A Study on Electrical Resistivity Geophysical Surveys of the Noen Landfill Site (전기비저항 탐사를 이용한 노은매립장 침출수 분포에 관한 연구)

  • Kim, Jun-Kyoung;Hong, Sang-Pyo;Kim, Kwang-Yul;Cho, Yong-Jin
    • Journal of Environmental Impact Assessment
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    • v.13 no.5
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    • pp.223-230
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    • 2004
  • The electrical resistivity prospecting method with dipole-dipole array were applied in order to survey 3-D structure characteristics of the Noen landfill site. For the electrical resistivity prospecting, 3 line of measurements were established parallel to the main boundary of the Noen landfill site and additional 2 lines were also established perpendicular to the existing 3 lines for the effective investigation of the landfill site. The results showed that the uppermost layer of the landfill site is believed to be stabilized generally based on the characteristics of electrical resistivity distribution. Lowest layer was partially polluted by the leachate.

Surface Reconstruction on Hydrogen Covered W(011) (수소가 흡착된 W(011) 표면의 재구성)

  • 김희봉;최원국;홍사용;황정남;정광호
    • Journal of the Korean Vacuum Society
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    • v.1 no.1
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    • pp.83-87
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    • 1992
  • Rencently, angle-resolved ultraviolet photoemission measurements of the Fermi surface contours for Mo(011) and W(011) are reported. The electron contour of W(011) is expanded upon hydrogen adsorption, which implies that the surface states consisting of electron pockets are shifted to higher binding energy. This phenomena can be explained by the band flattening. We explained here the reconstruction of W(011) surface induced by adsorption of hydrogen in terms of band flattening of surface states with a combination of S. E. Trullinger long range dipole-dipole interaction force and Kohn anomaly.

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An Interpretation of Hydrogeologic Structure Using Geophysical Data from Chungwon Area, Chungcheongbuk-Do (물리탐사자료를 이용한 수리지질구조 해석 -충청북도 청원지역)

  • 송성호;정형재;권병두
    • Economic and Environmental Geology
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    • v.33 no.4
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    • pp.283-293
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    • 2000
  • A set of geophysical survey results over an area in Bookil-myun, Chungwon-Gun, Chungcheongbuk-Do is presented; resistivity logging, d.c. sounding, dipole-dipole resistivity, and controlled-source magnetotelluric (CSMT) surveys. These surveys were chosen in this research for the estimation of the basement depth and the delineation of the hydrogeologic structure over the survey area. The results provide an optimal input to a hydrogeologic modeling analysis using the strategies built in GIS software. A total of 14 lines of dipole-dipole resistivity surveys, 25 stations of d.c. sounding and 6 stations of CSMT sounding were performed. In addition 10 boreholes were chosen for resistivity logging to correlate the logs to the surface data. A quantitative information on the hydrogeologic structure over the area is provided by synthesizing the results from various geophysical data and attribute layers are constructed by utilizing a GIS software Arc/ Info. The constructed layers match well to the hydrogeologic structures, which were outlined from the drilling data. The methodology tested and adopted in this study would be useful for providing a more reliable input to the hydrogeologic model setup.

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