• Title/Summary/Keyword: Dipole moment

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Analysis of the Transversely fed EMC Microstrip Dipole Array Antenna (급전선과 직교된 전자기결합 마이크로스트립 다이폴 배열안테나의 해석)

  • 손영수;윤현보
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.7 no.2
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    • pp.105-116
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    • 1996
  • The design and analysis of the transversely fed EMC(electromagnetically coupled) microstrip dipole have been accomplished by using the integral equation and MOM(method of moment)in frequency domain in order to find the current distribution of the dipole. In this study, we proposed the possibilities for design and analysis of EMC micro-strip dipole array antenna by means of calculating the current distribution of each dipole directly using the FDTD(finite difference time domain) method. In this case, we applied the formulation which is the finite difference expression of the Maxwell's integral equation. From the current distribution of each dipole, we calculated the far field electric component and showed that the calculation process and running time was reduced with respect to the method which calculates the radiation field with surface electric and magnetic current density.

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A Study on the Physical Properties of Saturated Fatty Acids for External Stimulus (외부자극에 대한 포화지방산의 물성평가)

  • 조완제;구창권;송경호;박태곤;박근호
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1998.11a
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    • pp.179-182
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    • 1998
  • The structural changes of molecules on the water surface were measured by displacement currents and $\pi$-A isotherm. By using a theoretical equations we calculated charges($\Delta$Q) and dipole moment( $m_{z}$) of saturated fatty acids( $C_{12}$, $C_{14}$, $C_{16}$). The dynamic behavior of saturated fatty acid monolayers at the air/water interface was investigated using a displacement current-measuring technique coupled with the so called Langmuir film technique and also the dipole moment of the acids was determined.as determined.d.

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A Study on the Stimulus Reaction of PBLG (PBLG의 자격반응에 관한 연구)

  • Kim, Beyung-Geun;Chang, Hun;Lee, Kyung-Sup
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.07b
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    • pp.719-722
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    • 2002
  • The Displacement current measurement system used in this experiment because detecting the dynamic behavior of monolayers at the air-water interface is possible. 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. PBLG phase transformation measured by Maxwell-displacement-current-measurement method in surface of the water. Measured (surface pressure, displacement current and dipole moment) of monolayers of PBLG on the water surface. We measured displacement current that occur when changed temperature. Could know that displacement current is proportional in increase of temperature and great as experiment result.

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Exchange Bias Coupling Depending on Uniaxial Deposition Field of Antiferromagnetic FeMn Layer

  • Lee, Sang-Suk;Hwang, Do-Guwn
    • Journal of Magnetics
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    • v.15 no.1
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    • pp.17-20
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    • 2010
  • The relationship between ferromagnet anisotropic magnetization and the antiferromagnet atomic spin configuration was investigated for various angles of the uniaxial deposition magnetic field of the FeMn layer in the Corning glass/Ta(5nm)/NiFe(7nm)/FeMn(25nm)/Ta(5nm) multilayer that was prepared by the ion beam sputter deposition. The exchange bias field ($H_{ex}$) obtained from the measurement of the easy-axis MR loop decreased to 40 Oe at the deposition field angle of $45^{\circ}$, and to 0 Oe at the angle of $90^{\circ}$. When the difference between the uniaxial axis between the ferromagnet NiFe and the antiferromagnet FeMn was $90^{\circ}$, the strong antiferromagnetic dipole moment of FeMn caused the weak ferromagnetic dipole moment of NiFe to rotate in the interface.

Nitrogen Adsorption on the Stepped Planes of Tungsten: I.(210) Plane (텅스텐 결정면의 질소 흡착에 관한 연구 : I. (210)면)

  • 최대선;한종훈;백선목;박노길;김기석;김기석;황정남
    • Journal of the Korean Vacuum Society
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    • v.4 no.4
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    • pp.358-366
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    • 1995
  • W(210)면의 질소 흡착에 의한 일함수의 변화, heat of desorption 및 흡착 site에 대하여 조사하였다. 텅스텐(210)면에 질소가 흡착될 때 흡착율에 따라 일함수는 증가하다가 최대 변화량 0.29eV에서 포화되었다. TDS결과로부터 이 면은 진소에 대하여 적어도 3개의 흡착 site가 있음을 알았고 high dose에서 흡착되는 $\beta$1 state까지 포함하면 모두 4개의 흡착 site 가 있으며 이 흡착 site들 중 $\alpha$1 state를 제외하고는 모두 일함수를 증가시키는 site임을 알았다. 질소는 W(210)면의 step((100)면)과 terrace((110)면)의 중 step에 흡착되고 독립된, 즉 무한히 큰 W(100)면의 $\alpha$1, $\alpha$2, 그리고 $\beta$2 state에 대응되는 흡착 site에 흡착된 질소의 dipole moment의 방향은 W(210)면의 step((100)면의 일부)의 $\alpha$1, $\alpha$2, 그리고 $\beta$2 state에 대응되는 흡착 site에 흡착된 질소의 dipole moment의 방향과 반대방향임을 알았다.

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Analysis of Electromagnetically cCoupled Microstrip Transverse Dipole using Finite Difference Time Domain (FDTD) Method (시간영역 유한차분법을 이용한 전자기결합 마이크로스트립 수직다이폴의 해석)

  • 손영수;윤현보
    • The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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    • v.5 no.4
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    • pp.30-39
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    • 1994
  • The resonant frequency, reflection cofficient and input impedance of a microstrip transverse dipole coupled electromagnetically are calculated using Finite Difference Time Domain(FDTD) method, and the evolution of gaussian pulse and spatial distribution of electromagnetic field components in the computation domain is represented graphically. Also, we confirmed the computation results show good agreement with the results of Method of Moment(MOM) and experiment[8] reported in the literature.

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Dipole Moment Derivatives and Infrared Intensities of SiH$_4$ and SiD$_4$

  • Kim, Kwan;Lee, Hwi-Geon
    • Bulletin of the Korean Chemical Society
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    • v.6 no.2
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    • pp.79-86
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    • 1985
  • The complete neglect of differential overlap (CNDO/2) approximate wavefunctions have been applied to select the preferred signs for the dipole moment derivatives of SiH$_{4}$ and SiD$_{4}$ in conjunction with the experimental alternatives. The apparent sign discrepancy from earlier report has been identified. The effective atomic charge for hydrogen was found to be X$_{H}$/e = 0.229, more than two times larger in comparison with the values of typical hydrocarbons like CH$_{4}$. The anomalously large effective hydrogen charge was interpreted based on a quantum mechanical model as well as the value of atom anisotropy relative to effective atomic charge.

The Potential Energy Surfaces and Dipole Moment Functions of $NH_2$ by ab initio Effective Valence Shell Hamiltonian

  • 윤승훈;윤영속;박종근;선호성
    • Bulletin of the Korean Chemical Society
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    • v.19 no.9
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    • pp.985-993
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    • 1998
  • The second order effective valence shell Hamiltonian ($H^v$), which is based on quasidegencrate many-body perturbation theory, is applied to determining the potential energy surfaces and the dipole moment functions of the various valence states of $NH_2$. The $H^v$ calculated values are found to be in good agreement with those of other ab initio calculations or experiments. It signifies the fact that the $H^v$ is a good ab initio method to describe the energies and properties of various valence states with a same chemical accuracy. Furthermore, it is shown that the lowest (second order for energy and the first order for property) order $H^v$ method is very accurate for small molecules like $NH_2$ and the matrix elements of Hv which are computed only once are all we need to accurately describe all the valence states simultaneously.

Conformational Change of Optically Active [Co(acac)$_2$(diamine)]$^+$ Complexes in Some Organic Solvents

  • Kim, Yang;Oh Chang-Eon
    • Bulletin of the Korean Chemical Society
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    • v.8 no.6
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    • pp.441-444
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    • 1987
  • The circular dichroism(CD) spectra of the optically active [$Co(acac)_2(diamine)]^+$ complexes were measured in the several protic and aprotic solvents, where acac = acetylacetonate anion and diamine = ethylenediamine and trimethylenediamine. The degree of the CD variation in protic solvents was enhanced as the dielectric constant decreases except n-butanol and benzylalcohol. And the degree of the CD variation in aprotic solvents was roughly increased as both dipole moment and dielectric constant decrease except aromatic solvents and the solvents having no dipole moment. It was deduced that the CD variations of the complexes have been due to the conformational change of acetylacetonate ligands coordinated to Co(III) ion.

Excited State Proton Transfers and Subsequent Electron Rearrangement of Aqueous 6-Hydroxyquinoline

  • 유현웅;권혁진;장두전
    • Bulletin of the Korean Chemical Society
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    • v.18 no.2
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    • pp.156-161
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    • 1997
  • Aqueous 6-hydroxyquinoline in the first excited singlet state undergoes protonation to the imine group first in 15 ps, then in the time scale of 40 ps deprotonation from the enol group and finally, however, quickly as in 11 ps electron rearrangement to change into a resonance hybrid structure of quinoid-prevailing forms. Despite the fact that the decay time constant is smaller than the formation time constant, fluorescence from excited protropic zwitterion is observed to assign its maximum at 510 nm. The electron rearrangement is basically an intramolecular charge transfer from the deprotonated oxygen atom to the positively charged iminium ring without any notable change in nuclear geometry, producing a zwitterionic quinoid structure with much a smaller electric dipole moment than the zwitterionic protropic species. This photoproduct formed by consecutive excited state proton and electron transfers shows a smaller dipole moment in S1 than in S0 and a hypsochromic shift although its S1 state has (π, π*) character.