• Nuclear Engineering and Technology
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• 제49권5호
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• pp.1006-1009
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• 2017

We discuss the problems of scattering in this framework, and show that the applied method is very useful in the investigation of the effect of the resonance in the observed scattering cross sections. In this study, not only the scattering cross sections but also the decomposition of the scattering cross sections was computed for the ${\alpha}-{\alpha}$ system. To obtain the decomposition of scattering cross sections into resonance and residual continuum terms, the complex scaled orthogonality condition model and the extended completeness relation are used. Applying the present method to the ${\alpha}-{\alpha}$ and ${\alpha}-n$ systems, we obtained good reproduction of the observed phase shifts and cross sections. The decomposition into resonance and continuum terms makes clear that resonance contributions are dominant but continuum terms and their interference are not negligible. To understand the behavior of observed phase shifts and the shape of the cross sections, both resonance and continuum terms are calculated.

• 한국소음진동공학회논문집
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• 제20권1호
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• pp.22-28
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• 2010

Approximate analysis for a building installed with a friction damper is performed to get insight of its dynamic behavior. Energy balance equation is used to have a closed analytical form solution of dynamic magnification factor(DMF). It is found out that DMF is dependent on friction force ratio and resonance frequency. Approximation of DMF and equivalent damping ratio of a friction damper is proposed with such assumption that the building with a friction damper shows harmonic steady-state response and narrow banded response behavior near resonance frequency. Linear transfer function from input external force to output building displacement is suggested from the simplified DMF equation. Root mean square of a building displacement is derived under earthquake-like random excitation. Finally, design procedure of a friction damper is proposed by finding friction force corresponding to target control ratio. Numerical analysis is carried out to verify the proposed design procedure.

• Current Optics and Photonics
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• 제4권2호
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• pp.134-140
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• 2020

A significant enhancement of the magneto-optical Faraday rotation and extraordinary optical transmission (EOT) in the cascaded double-fishnet (CDF) structure with periodic rectangular apertures is theoretically predicted by using the extended finite difference time domain (FDTD) method. The results demonstrate that the transmittance spectrum of the CDF structure has two EOT resonant peaks in a broad spectrum spanning visible to near-infrared wavebands, one of them coinciding with the enhanced Faraday rotation and large figure of merit (FOM) at the same wavelength. It is most important that the resonant position and intensity of the transmittance, Faraday rotation and FOM can be simply tailored by adjusting the incident wavelength, the thickness of the magnetic layer, and the offset between two metallic rectangular apertures, etc. Furthermore, the intrinsic physical mechanism of the resonance characteristics of the transmittance and Faraday rotation is thoroughly studied by investigating the electromagnetic field distributions at the location of resonance. It is shown that the transmittance resonance is mainly determined by different hybrid modes of surface plasmons (SPs) and plasmonic electromagnetically induced transparency (EIT) behavior, and the enhancement of Faraday rotation is mostly governed by the plasmonic electromagnetically induced absorption (EIA) behavior and the conversion of the transverse magnetic (TM) mode and transverse electric (TE) mode in the magnetic dielectric layer.

• 한국자기공명학회논문지
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• 제12권1호
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• pp.26-32
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• 2008

We report on the ferromagnetic characteristics of $Zn_{1-x}Mn_xO$ films (x = 0.3) prepared by sol-gel method on the silicon and (0001) ${\alpha}-Al_2O_3$ substrates at the annealing temperature of 700$^{\circ}C$. Magnetic measurements show that Curie temperature ($T_C$) and the coercive field ($H_C$) for the film on the silicon are about 32 K and about 275 Oe, while those for that on the sapphire are about 32 K and 425 Oe, respectively. Energy dispersive spectroscopy and transmission electron microscopy measurements suggest that ferromagnetic precipitates originated by manganese oxide compound formed at the interfaces of the both substrates may be responsible for the observed ferromagnetic behavior of the films. Electron paramagnetic resonance study of the powders up to the concentration of x=0.15 supports the result.

• Steel and Composite Structures
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• 제49권3호
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• pp.325-335
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• 2023

The missile is affected by both spinning and axial motion during its movement, which will have a very adverse impact on the stability and reliability of the missile. This paper regards missiles as cylindrical shell structures with spinning and axial motion. In this article, the forced vibration of carbon nanotube-reinforced composites (CNTRCs) cylindrical shells with spinning motion and axial motion is investigated, in which the clamped-clamped and simply-simply supported boundary conditions are considered. The displacement field is described by the first-order shear theory, and the vibration equation is deduced by using the Euler-Lagrange equation, after dimensionless processing, the dimensionless equation of motion is obtained. The correctness of this paper is verified by comparing with the results of the existing literature, in which the simply-simply supported ends are taken into account. In the end, the effects of different parameters such as spinning velocity, axial velocity, carbon nanotube volume fraction, length thickness ratio and load position on the resonance behavior of cylindrical shells are given. It can be found that these parameters can significantly change the resonance of axially moving and rotating moving CNTRCs cylindrical shells.

• International Journal of Internet, Broadcasting and Communication
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• 제4권2호
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• pp.22-27
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• 2012

The design characteristics of circular vertical-cavity surface-emitting lasers are studied by using a newly developed equivalent network. Optical parameters, such as the stop-band or the reflectivity of periodic mirrors and the resonance wavelength, are explored for the design of these structures. To evaluate the differential quantum efficiency and the threshold current density, a transverse resonance condition of modal transmission-line theory is also utilized. This approach dramatically reduces the computational time as well as gives an explicit insight to explore the optical characteristics of circular vertical-cavity surface-emitting lasers (VCSELs).

• Journal of Magnetics
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• 제4권3호
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• pp.92-97
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• 1999

A relationship between microstructure and ferromagnetic resonance of Co/Ag multilayers has been studied in as-deposited and annealed multilayers iwth ultrathin (dCo < 1 nm) Co layers. Depending on the nominal thickness of Co Co/Ag multilayers represent a system of fine magnetic particles (dCo < 0.4 nm) or discontionuous layered structure (dCo/0.5 nm). FMR data has been interpreted in the framework of a odel of interacting fine particles exhibiting superparamagnetic behavior. Changes in the FMR spectra upon annealing have been attributed to the growth of the Co particles and to a transition from the fcc to hcp atomic structure of the highly (111) textured Co particles.

• 한국자기공명학회논문지
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• 제21권2호
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• pp.55-62
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• 2017

It is now well established that RNAs exhibit fundamental roles in regulating cellular processes. Many of these RNAs do not exist in a single conformation. Rather, they undergo dynamic transitions among many different conformations to mediate critical interactions with other biomolecules such as proteins, RNAs, DNAs, or small molecules. Here, we briefly review NMR techniques that describe the dynamic behavior of RNA by determining structural, kinetic, and thermodynamic properties.

• 한국철도학회논문집
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• 제8권3호
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• pp.228-234
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• 2005

Investigation on the dynamic behavior of railway bridges has not performed widely to date except high-speed railway bridges. In this study, 3-dimensional model is used for the finite element analysis of plate girder railway bridges. Train loads obtained through statistical approach of the measured true train loads are used. Numerical analysis is carried out about a 18m-span bridge. This result is compared with that of the experimental test of existing plate gilder railway bridge without ballast. The good agreement was obtained through the comparison. Judging from the analysis, resonant speed of diesel locomotive train is about 120km/h. However, the resonance for the other train is not found from the analysis.

• 대한기계학회논문집A
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• 제24권9호
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• pp.2220-2227
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• 2000

In this paper, dynamic photoelastic hybrid method is developed and its validity is certified. The dynamic photoelastic hybrid method can be used on the obtaining of dynamic stress intensity factors and dynamic stress components. The effect of crack length on the dynamic stress intensity factors is less than those on the static stress intensity factors. When structures are under the dynamic mixed mode load, dynamic stress intensity factor of mode I is almost produced. Dynamic loading device manufactured in this research can be used on the research of dynamic behavior when mechanical resonance is produced and when crack is propagated with the constant velocity.