• Title/Summary/Keyword: Scattering Analysis

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Low Temperature Magnetization and Spin Wave Excitations in Amorphous Fe67 Co18B14Si1

  • Yoo, Yong-Goo;Yu, Seong-Cho;Hans A. Graf
    • Journal of Magnetics
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    • v.2 no.3
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    • pp.72-75
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    • 1997
  • The temperature dependent saturation magnetization curve of amorphous Fe67 Co18B14Si1, alloy was measured using a SQUID magnetometer and vibrating sample magnetometer from 5 K up to 800 K. Inelastic neutron neutron scattering measurements also have been used to study the long wavelength spin dynamics of this high Tc amorphous ferromagnetic alloy. The magnon dispersion curve exhibit the conventional quadratic relationship E = D (T) q2 + $\Delta$, typical of an iso=obtained from a low temperature magnetization curve, which was consistent with the value obtained from the analysis oif inelastic neutron scattering data after consideration of its temperature dependence.

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Scattering by Arbitrary Shaped Grating Covered with Dielectric Slab (유전체로 덮힌 임의 형태 격자구조의 산란)

  • Jo, Ung-Hui;Jo, Yeong-Gi
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.37 no.12
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    • pp.9-14
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    • 2000
  • A numerical method for scattering of electromagnetic waves from a arbitrary shaped grating covered with dielectric slab is considered for TE polarization case from the viewpoints of both reflection grating problem and leaky wave antenna problem. The analysis is based on a periodic Green's function and the method of moments. Numerical results involving some combinations of geometric parameters are presented in terms of relative scattered powers of spectral modes and complex propagation constants.

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SERS Analysis of CMC on Gold-Assembled Micelle

  • Jang, Nak-Han
    • Bulletin of the Korean Chemical Society
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    • v.25 no.9
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    • pp.1392-1396
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    • 2004
  • The micellization of dodecylpyridinum chloride (DPC) assembled on aqueous gold nanoparticles has been studied as a function of concentration using Surface-Enhanced Raman Scattering (SERS). At the low concentration, the strong SERS band of the benzene ring moiety was observed at 1025 $cm^{-1}$, and assigned to “trigonal ring breathing”. According to high concentration of DPC, a new strong band was also appeared at 1012 $cm^{-1}$, which was assigned to “totally symmetry ring breathing”. The difference of two spectra seems to ascribe to the geometry of polar head group, i.e., pyridinium cation. These geometry exist flat-down at low concentration, whereas standing-up or tilted geometry at high concentration. The critical micelle concentration (CMC) was first obtained from the ratio of intensities of the two bands related to the benzene ring moiety by vibrational spectroscopy, and was about 28 mM. After the CMC, the benzene ring moiety in the micelle state was more restricted than in monomer state because there is no more change of intensities at 1012 $cm^{-1}$. In addition, the size of gold-assembled micelle was estimated using light scattering and it was about 328.3 nm.

Recent developments in the GENESIS code based on the Legendre polynomial expansion of angular flux method

  • Yamamoto, Akio;Giho, Akinori;Endo, Tomohiro
    • Nuclear Engineering and Technology
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    • v.49 no.6
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    • pp.1143-1156
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    • 2017
  • This paper describes recent development activities of the GENESIS code, which is a transport code for heterogeneous three-dimensional geometry, focusing on applications to reactor core analysis. For the treatment of anisotropic scattering, the concept of the simplified Pn method is introduced in order to reduce storage of flux moments. The accuracy of the present method is verified through a benchmark problem. Next, the iteration stability of the GENESIS code for the highly voided condition, which would appear in a severe accident (e.g., design extension) conditions, is discussed. The efficiencies of the coarse mesh finite difference and generalized coarse mesh rebalance acceleration methods are verified with various stabilization techniques. Use of the effective diffusion coefficient and the artificial grid diffusion coefficients are found to be effective to stabilize the acceleration calculation in highly voided conditions.

Physical issues for the next generation of nano devices (차세대 나노소자에서의 물리적 논점)

  • Cho, Mann-Ho
    • Vacuum Magazine
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    • v.1 no.3
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    • pp.21-27
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    • 2014
  • Advanced process and integration for future semiconductor devices is approaching the physical limit. The new materials with low dimensional structure have recently attracted great attention due to its expandability for the future electronic devices. In order to apply the materials to future semiconductor devices, the control of carrier scattering is critical issue. That is, the carrier scattering with physical quantity in low dimensional structure significantly modulates the device characteristics. We introduce the role of defect in several future semiconductor materials and devices. The analysis of defect in the structure becomes the most important techniques. In particular, surface defect in nano structures totally controls the device characteristics. The changes imply that the metrology field is leading the future industry for semiconductor.

Analysis of false alarm possibility using simulation of back-scattering signals from water masses (수괴 산란신호 모의를 통한 오탐 가능성 분석)

  • Ha, Yonghoon
    • The Journal of the Acoustical Society of Korea
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    • v.40 no.2
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    • pp.99-108
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    • 2021
  • In this paper numerical wave propagation experiments have been performed to visually confirm whether the signals scattered by water masses can be a false alarm in active sonar. The numerical environments consist of exaggerated water masses as targets in free space. Using a pseudospectral time-domain model for irregular boundary, the back-scattered signals have been calculated and compared with analytic solutions. Also, the sound propagation was simulated. Consequently, it was verified that water masses themselves could not be detected as a false target.

A Fundamental Study about Vibration Analysis of Plasma Rock Fragmentation Method (플라즈마 파암공법의 진동분석에 관한 기초적인 연구)

  • 윤지선;김상훈
    • Proceedings of the Korean Geotechical Society Conference
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    • 2001.03a
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    • pp.129-136
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    • 2001
  • Blasting method is used most engineering works for rock excavation. Blasting method is done much to upgrade of operation efficiency, contraction of construction period than other method. But blasting method happens damage by blasting vibration, nose and scattering. Therefore this study examined about effect, characteristic and application of Plasma method. To confirm effect measured vibration, noise and frequency, and analyzed data compare with general blasting.

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