• Title/Summary/Keyword: Resonance Parameters

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Evaluation of Neutron Cross Sections of Dy Isotopes in the Resonance Region

  • Oh, Soo-Youl;Gil, Choong-Sup;Jonghwa Chang
    • Nuclear Engineering and Technology
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    • v.33 no.1
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    • pp.46-61
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    • 2001
  • The neutron cross sections of $^{160}$ Dy, $^{161}$ Dy, $^{162}$ Dy, $^{l63}$Dy, and $^{164}$ Dy have been evaluated in the resonance region of which upper energy is set to several tens of keV. The cross sections are formulated with resonance parameters in the energy region under consideration. In the resolved resonance region, the positive-energy resonance parameters were adopted from the BNL compilation published in 1984 with slight, if any, modifications. A bound level resonance for each isotope except $^{162}$ Dy was invoked to reproduce the reference 2200 m/s cross sections and the bound coherent scattering length. Subsequently, the statistical behavior of the resolved resonance parameters was analyzed, and thus obtained s-wave average parameters were adopted in the unresolved resonance region. In addition, recent measurements of the capture cross sections in the unresolved region were taken into account in adjusting the average resonance parameters for high orbital angular momentum resonances. The present evaluation resulted in large improvements in the cross sections over the ENDF/B-Vl release 6.6.

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Design of multi-layered surface plasmon resonance sensors using optical admittance method and evolution algorithm (광학 어드미턴스 기법과 진화 알고리즘 기법을 이용한 다층 표면 플라즈몬 공명 센서의 설계)

  • Jung, Jae-Hoon;Lee, Seung-Ki
    • Journal of Sensor Science and Technology
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    • v.14 no.6
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    • pp.402-408
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    • 2005
  • This paper describes the optimal design of a multi-layered surface plasmon resonance sensors to meet various specifications and improve some physical parameters. Dip 3 dB bandwidth and depth were chosen as design parameters and the objective function was the norm of the difference between design parameters and target values. The design variables are thicknesses of each layer and to obtain the design parameters, the optical admittance method was employed. The (1+1) evolution strategy was employed as an optimization tool. By applying the proposed optimization procedure to a 3-layered sensor, the optimized design variables considerably improved the 3 dB bandwidth by 4.8 nm and the dip depth by 1.1 dB.

Study on Performances of the Lever Type Anti-resonance Vibration Isolator (레버형 반공진 진동 절연기의 진동 특성 연구)

  • Yun, Jong-Hwan;Kim, Gi-Woo;Lee, Hyeongill
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.26 no.2
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    • pp.187-194
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    • 2016
  • Parametric study on the lever type dynamic anti-resonance vibration isolator (DAVI) is executed to introduce the system in the path of vibration transmission for the vibratory response attenuation. The effects of inertia and location of the lever on the system performances are investigated using FEA. The effects of other parameters such as ratio of lever lengths, ratio of masses and the location of pivot are studied with analytical approach. According to the results, all the parameters except lever location affect the system response in their own ways. Consequently, the optimal lever type DAVI for translational or rotational system can be efficiently designed by selecting system parameters using the procedure introduced in this study.

An Application of Surface Plasmon Resonance to Evaluation of Quality Parameters of Soybean Oil during Frying

  • Gil, Bo-Gim;Chang, Young-Ki;Cho, Yong-Jin
    • Food Science and Biotechnology
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    • v.15 no.3
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    • pp.404-408
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    • 2006
  • Feasibility of surface plasmon resonance (SPR) method to evaluate soybean frying oil quality was evaluated. Free fatty acid value, p-anisidine value, conjugated dienoic acid content, conjugated trienoic acid content, peroxide value, iodine value, total polar compound (TPC), ratio of unsaturated fatty acid to saturated fatty acid, refractive index, dielectric constant, smoking point, and L, a, and b of Hunter color system were selected as parameters related to conventional evaluation of soybean frying oil quality. SPR scale mapped with conventional quality parameters well described free fatty acid value, conjugated dienoic acid content, dielectric constant, TPC, and b of Hunter color system, as shown by correlation and linear regression analyses.

An Investigation of Control Parameters of Active Filters Based on Voltage Detection

  • SATO Yukihiko;KAWASE Takeshi;MACHIDA Hiraku
    • Proceedings of the KIPE Conference
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    • 2001.10a
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    • pp.475-479
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    • 2001
  • Compensation characteristics or active filters based on voltage detection are investigated. These active filters act equivalently as a passive circuit so that they may not cause practical problems such as stimulation of resonance in the distribution lines. Thus, these active filters can be used as the general-purpose active filters. On the other hand, these active filters may have a possibility of the anti-resonance associated with the line inductance of the distribution lines. In this paper, the relationship between the anti-resonance and the control parameters of the proposed active filters is clarified. Some methods to avoid the problems due to the anti-resonance are investigated. Experimental results are included to confirm the validity of the investigation presented in this paper.

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Nonlinear Oscillation Characteristics in Combination Resonance Region Considering Damping Effects (조합공진 영역에서 감쇠의 영향을 고려한 비선형 진동 응답 특성)

  • Jeong, Tae-Gun
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.20 no.9
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    • pp.849-855
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    • 2010
  • Damping may change the response characteristics of nonlinear oscillations due to the parametric excitation of a thin cantilever beam. When the natural frequencies of the first bending and torsional modes are of the same order of magnitude, we can observe the one-to-one combination resonance in the perturbation analysis depending on the characteristic parameters. The nonlinear behavior about the combination resonance reveals a chaotic motion depending on the natural frequencies and damping ratio. We can analyze the chaotic dynamics by using the eigenvalue analysis of the perturbed components. In this paper, we derived the equations for autonomous system and solved them to obtain the characteristic equation. The stability analysis was carried out by examining the eigenvalues. Numerical integration gave the physical behavior of each mode for given parameters.

Kinetic and Theoretical Consideration of 3,4- and 3,5-Dimethoxybenzoyl Chlorides Solvolyses

  • Park, Kyoung-Ho;Kevill, Dennis N.
    • Bulletin of the Korean Chemical Society
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    • v.34 no.10
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    • pp.2989-2994
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    • 2013
  • The solvolysis rate constants of 3,4- (1) and 3,5-dimethoxybenzoyl (2) chlorides were measured in various pure and binary solvents at $25.0^{\circ}C$, and studied by application of the extended Grunwald-Winstein (G-W) equation, kinetic solvent isotope effect in methanolysis and activation parameters. The solvolysis of 1 was interpreted as the unimolecular pathway due to a predominant resonance effect from para-methoxy substituent like 4-methoxybenzoyl chloride (3), while that of 2 was evaluated as the dual mechanism, with unimolecular or bimolecular reaction pathway according to the character of solvent systems (high electrophilic/nucleophilic) chosen, caused by the inductive effect by two meta-methoxy substituents, no resonance one. In the solvolyses of 1 and 2 with two $-OCH_3$ groups, the resonance effect of para-methoxy substituent is more important to decide the mechanism than the inductive effect with other corresponding evidences.

Decoupling of Background and Resonance Scatterings in Multichannel Quantum Defect Theory and Extraction of Dynamic Parameters from Lu-Fano Plot

  • Lee, Chun-Woo
    • Bulletin of the Korean Chemical Society
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    • v.30 no.4
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    • pp.891-896
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    • 2009
  • Giusti-Suzor and Fano introduced translations of the scales of Lu-Fano plots by phase renormalization in order to decouple the intra- and inter-channel couplings in multichannel quantum defect theory (MQDT). Their theory was further developed by others to deal with systems involving a larger number of channels. In different directions, MQDT was reformulated into forms with a one-to-one correspondence to those in Fano's configuration mixing theory of resonance for photofragmentation processes involving one closed and many open channels. In this study, the theory was further developed to fully reveal the coupling nature, decoupling of the background and resonance scattering in physical scattering matrices as well as to further extract the dynamic parameters undiscovered by Fano and his colleagues. This theory was applied to the photoabsorption spectrum of $H_2$ observed by Herzberg's group.

Analysis of Magnetic Permeability Spectra of Metamaterials Composed of Cut Wire Pairs by Circuit Theory

  • Lim, Jun-Hee;Kim, Sung-Soo
    • Journal of Magnetics
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    • v.21 no.2
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    • pp.187-191
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    • 2016
  • Retrieving the equivalent electromagnetic parameters (permittivity and permeability) plays an important role in the research and application of metamaterials. Frequency dispersion of magnetic permeability has been theoretically predicted in a metamaterial composed of cut wire pairs (CWP) separated by dielectric substrate on the basis of circuit theory. Magnetic resonance resulting from antiparallel currents between the CWP is observed at the frequency of minimum reflection loss (corresponding to absorption peak) and effective resonator size can be determined. Having calculated the circuit parameters (inductance L, capacitance C) and resonance frequency from CWP dimension, the frequency dispersion of permeability of Lorentz like magnetic response can be predicted. The simulated resonance frequency and permeability spectra can be explained well on the basis of the circuit theory of an RLC resonator.