Numerical study for ballistic switching of magnetization in single domain particle triggered by a ferromagnetic resonance within a relaxation time limit

2006 ◽  
Vol 100 (5) ◽  
pp. 053911 ◽  
Author(s):  
Y. Nozaki ◽  
K. Matsuyama
Keyword(s):  
Relaxation Time ◽  
Ferromagnetic Resonance ◽  
Numerical Study ◽  
Time Limit ◽  
Single Domain ◽  
Single Domain Particle

Analysis of single‐domain particle flow orientation data

1988 ◽  
Vol 64 (10) ◽  
pp. 5843-5845 ◽  
Author(s):  
Thomas E. Karis ◽  
Myung S. Jhon
Keyword(s):  
Single Domain ◽  
Particle Flow ◽  
Orientation Data ◽  
Single Domain Particle

scholarly journals Ferromagnetic Resonance Spectroscopy and Rock Magnetic Characterization of Fossil Coral Skeletons in Ishigaki Islands, Japan

Geosciences ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 400
Author(s):  
Yuho Kumagai ◽  
Norihiro Nakamura ◽  
Tetsuro Sato ◽  
Toshitaka Oka ◽  
Hirokuni Oda
Keyword(s):  
Ferromagnetic Resonance ◽  
Single Domain ◽  
Coral Skeleton ◽  
Resonance Spectroscopy ◽  
Continuous Growth ◽  
Coral Skeletons ◽  
Ishigaki Island ◽  
Biogenic Magnetite ◽  
A Chain ◽  
Fossil Coral

Skeletons of hermatypic corals (e.g., Porites) might have enormous potential as a high-resolution paleomagnetic recorder owing to their rapid and continuous growth over hundreds of years at a rate of up to 2 cm/year, although typical corals show an extremely weak intensity of remanence and low stability. We found that coral tsunami boulders with negligible amounts of calcite on Ishigaki Island show a measurable intensity of remanence; thus, we attempted to characterize the magnetic assemblages in this coral skeleton to determine whether it is of biogenic or detrital magnetite using first-order reversal curve (FORC) measurements, ferromagnetic resonance (FMR) spectroscopy, and petrological observations through field-emission type scanning electron microscope (FE-SEM) with an acid treatment. The FMR derivative spectra of coral skeleton samples represent multiple derivative maxima and extended low-field absorption, indicating the presence of intact biogenic magnetite chains. FORC diagrams represent a “central ridge” signature with a vertical spread. These FMR and FORC features indicate the magnetization of these coral skeletons that are mainly created using intact biogenic magnetites and mixtures of grains from collapsed biogenic magnetites, pseudo-single domain grains, and multi-domain grains such as detrital magnetite. FE-SEM observations confirm the presence of a chain-like structure of iron oxides corresponding to the features of biogenic magnetite. Therefore, the magnetic mineral assemblage in coralline boulders from Ishigaki Island consists of dominant biogenic-origin single-domain magnetite and a trace amount of detrital component, indicating that fossil coral skeletons in Ishigaki Island have potential for utilization in paleomagnetic studies.

Numerical Analysis on the Effects of Mixed Convection of Particles Removal Flow over Heated Cavity Using Multi-Relaxation Time Thermal Lattice Boltzmann Method

2014 ◽  
Vol 695 ◽  
pp. 487-490
Author(s):  
Nor Azwadi Che Sidik ◽  
Aman Ali Khan
Keyword(s):  
Distribution Function ◽  
Relaxation Time ◽  
Aspect Ratio ◽  
Mixed Convection ◽  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Numerical Study ◽  
Grashof Number ◽  
Boltzmann Method ◽  
Thermal Lattice Boltzmann

This paper provides numerical study of the effects of mixed convection on particles removal from a cavity using multi-relaxation time thermal lattice Boltzmann method (LBM) for compute the flow and isotherm characteristics in the bottom heated cavity located on a floor of horizontal channel. A point force scheme was applied for particles-fluid interactionand double-distribution function (DFF) was coupled with MRT thermal LBM to study the effects of various grashof number (Gr) and Aspect Ratio (AR) on the efficiency of particles removal. The results show that change in Grashof number and Aspect ratio causes a dramatic different in the flow pattern and particles removal efficiency.

Instability of a viscous coflowing jet in a radial electric field

2008 ◽  
Vol 596 ◽  
pp. 285-311 ◽  
Author(s):  
FANG LI ◽  
XIE-YUAN YIN ◽  
XIE-ZHEN YIN
Keyword(s):  
Relaxation Time ◽  
Electric Field ◽  
Thin Layer ◽  
Euler Number ◽  
Radial Electric Field ◽  
Dispersion Relations ◽  
Time Limit ◽  
Liquid Viscosity ◽  
Electrical Relaxation ◽  
Thin Layer Approximation

A temporal linear instability analysis of a charged coflowing jet with two immiscible viscous liquids in a radial electric field is carried out for axisymmetric disturbances. According to the magnitude of the liquid viscosity relative to the ambient air viscosity, two generic cases are considered. The analytical dimensionless dispersion relations are derived and solved numerically. Two unstable modes, namely the para-sinuous mode and the para-varicose mode, are identified in the Rayleigh regime. The para-sinuous mode is found to always be dominant in the jet instability. Liquid viscosity clearly stabilizes the growth rates of the unstable modes, but its effect on the cut-off wavenumber is negligible. The radial electric field has a dual effect on the modes, stabilizing them when the electrical Euler number is smaller than a critical value and destabilizing them when it exceeds that value. Moreover, the electrical Euler number and Weber number increase the dominant and cut-off wavenumbers significantly. Based on the Taylor–Melcher leaky dielectric theory, two limit cases, i.e. the small electrical relaxation time limit (SERT) and the large electrical relaxation time limit (LERT), are discussed. For coflowing jets having a highly conducting outer liquid, SERT may serve as a good approximation. In addition, the dispersion relations under the thin layer approximation are derived, and it is concluded that the accuracy of the thin layer approximation is closely related to the values of the dimensionless parameters.

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