scholarly journals 3D motion of flexible ferromagnetic filaments under a rotating magnetic field

Soft Matter ◽  
2020 ◽  
Vol 16 (18) ◽  
pp. 4477-4483 ◽  
Author(s):  
Abdelqader Zaben ◽  
Guntars Kitenbergs ◽  
Andrejs Cēbers
Keyword(s):  
Magnetic Field ◽  
Numerical Study ◽  
Rotating Magnetic Field ◽  
3D Motion ◽  
Rotating Field

Experimental and numerical study of flexible ferromagnetic filaments reveal different regimes, when subjected to a 2D rotating field. The filaments were found to have a 3D motion at higher frequencies.

A numerical study of flows driven by a rotating magnetic field in a square container

PAMM ◽  
2008 ◽  
Vol 8 (1) ◽  
pp. 10953-10954 ◽  
Author(s):  
K. Fraňa ◽  
J. Stiller ◽  
K. Horáková
Keyword(s):  
Magnetic Field ◽  
Numerical Study ◽  
Rotating Magnetic Field

An experimental investigation of current production by means of rotating magnetic fields

1981 ◽  
Vol 26 (3) ◽  
pp. 465-480 ◽  
Author(s):  
W. N. Hugrass ◽  
I. R. Jones ◽  
M. G. R. Phillips
Keyword(s):  
Magnetic Field ◽  
Experimental Investigation ◽  
Threshold Value ◽  
Rotating Magnetic Field ◽  
Electron Current ◽  
Rotating Magnetic Fields ◽  
Theta Pinch ◽  
Current Production ◽  
Made In ◽  
Rotating Field

An investigation of current production by means of a rotating magnetic field is made in an experiment in which the technique is used to generate a theta-pinch- like distribution of field and plasma. Detailed measurements are made of both the generated unidirectional azimuthal electron current and the penetration of the rotating field into the plasma. The experimental results support the theoretical prediction that a threshold value of the amplitude of the applied rotating field exists for setting the electrons into rotation.

FLEXIBLE FERROMAGNETIC FILAMENTS AS ARTIFICIAL CILIA

2011 ◽  
Vol 25 (07) ◽  
pp. 935-941 ◽  
Author(s):  
A. CĒBERS ◽  
R. LIVANOVIČS
Keyword(s):  
Magnetic Field ◽  
Numerical Algorithm ◽  
Rotating Magnetic Field ◽  
Artificial Cilia ◽  
Fixed End ◽  
Rotating Field

The model of an artificial cilia as a flexible ferromagnetic filament in a rotating magnetic field is proposed. Numerical algorithm for the simulation of its behavior is developed and the characteristic shapes of the filament with one fixed end under the action of a rotating field are found. It is concluded that ferromagnetic filaments may be used as mixers in microfluidics.

Cylindrical plasma equilibria maintained by means of a rotating magnetic field

1982 ◽  
Vol 28 (2) ◽  
pp. 369-378 ◽  
Author(s):  
W. N. Hugrass
Keyword(s):  
Magnetic Field ◽  
Axial Magnetic Field ◽  
Fluid Model ◽  
Radial Electric Field ◽  
Azimuthal Velocity ◽  
Transverse Magnetic ◽  
Rotating Magnetic Field ◽  
Two Fluid Model ◽  
Image Position ◽  
Rotating Field

The equilibrium of a plasma cylinder confined by means of a steady axial magnetic field, Bα, and a transverse magnetic field, Bω, which rotates about the axis of the cylinder is analysed using a two-fluid model. It is shown that the electron fluid is tied to the rotating field provided that The rotating field does not impart a steady azimuthal motion to the ions provided that However, the ion fluid acquires a steady azimuthal velocity due to electron-ion collisions. A self-consistent radial electric field is produced; this field plays an important role in establishing the steady ion flow.

Analytical solutions for the current driven by a rotating magnetic field in a spherical plasma

1991 ◽  
Vol 46 (2) ◽  
pp. 271-298 ◽  
Author(s):  
Peter A. Watterson
Keyword(s):  
Magnetic Field ◽  
Analytical Solutions ◽  
Rotation Frequency ◽  
Axial Current ◽  
Rotating Magnetic Field ◽  
Ohmic Dissipation ◽  
Field Magnitude ◽  
Synchronous Rotation ◽  
Spherical Plasma ◽  
Rotating Field

The steady currents driven in a spherical plasma by a rotating magnetic field via the Hall effect are studied analytically. The total field is shown to be symmetric across the origin. Integral relationships are obtained between Ohmic dissipation, angular momentum and the oscillating axial current density. The topology of the sum of a Hill's vortex field and a rotating field is documented. Analytical solutions for the driven current are obtained by expansion for the limits corresponding to small rotation frequency, to small number density, to large rotating-field magnitude, to small resistivity, and to small rotating-field magnitude combined with very small resistivity. The latter solution, relevant to the reactor limit, indicates that, with control of the vertical field magnitude, an MHD equilibrium can be generated with total current any fraction of the currentcorresponding to synchronous rotation of the electrons. Oscillating currents sufficient to drive the synchronous current are determined.

scholarly journals Power and Momentum Relations in Rotating Magnetic Field Current Drive

1984 ◽  
Vol 37 (5) ◽  
pp. 509 ◽  
Author(s):  
WN Hugrass
Keyword(s):  
Magnetic Field ◽  
Angular Momentum ◽  
Magnetic Fields ◽  
Phase Velocity ◽  
Current Drive ◽  
Rotating Magnetic Field ◽  
Plasma Current ◽  
Rotating Magnetic Fields ◽  
Frequency Source ◽  
Rotating Field

The use of rotating magnetic fields (RMF) to drive steady currents in plasmas involves a transfer of energy and angular momentum from the radio frequency source feeding the rotating field coils to the plasma. The. power-torque relationships in RMF systems are discussed and the analogy between RMF current drive and the polyphase induction motor is explained. The general relationship between the energy and angular momentum transfer is utilized to calculate the efficiency of the RMF plasma current drive. It is found that relatively high efficiencies can be achieved in RMF current drive because of the low phase velocity and small slip between the rotating field and the electron fluid.

scholarly journals Adiabatic quantum estimation: A numerical study of the Heisenberg XX model with antisymmetric exchange

2020 ◽  
pp. 2040001
Author(s):  
L. Fathi Shadehi ◽  
H. Rangani Jahromi ◽  
M. Ghanaatian
Keyword(s):  
Magnetic Field ◽  
Static Magnetic Field ◽  
Numerical Study ◽  
Quantum Fisher Information ◽  
Spin Coupling ◽  
Azimuthal Direction ◽  
Qubit System ◽  
Polar Orientation ◽  
The One ◽  
Rotating Field

In this paper, we address the adiabatic technique for quantum estimation of the azimuthal orientation of a magnetic field. Exactly solving a model consisting of a two-qubit system, where one of which is driven by a static magnetic field while the other is coupled with the magnetic field rotating adiabatically, we obtain the analytical expression of the quantum Fisher information (QFI). We investigate how the two-qubit system can be used to probe the azimuthal direction of the field and analyze the roles of the intensities of the magnetic fields, Dzyaloshinskii–Moriya (DM) interaction, spin–spin coupling coefficient, and the polar orientation of the rotating field on the precision of the estimation. In particular, it is illustrated that the QFI trapping or saturation may occur if the qubit is subjected to a strong rotating field. Moreover, we discuss how the azimuthal direction of the rotating field can be estimated using only the qubit not affected by that field and investigate the conditions under which this strategy is more efficient than use of the qubit locally interacting with the adiabatically rotating field. Interestingly, in the one-qubit scenario, it was found that when the rotating field is weak, the best estimation is achieved by subjecting the probe to a static magnetic field.

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