The magnetic field profiles of NGC 7331, NGC 2841, and NGC 6946 - A theoretical model

1988 ◽  
Vol 331 ◽  
pp. 116 ◽  
Author(s):  
E. Battaner ◽  
E. Florido ◽  
M. L. Sanchez-Saavedra
Keyword(s):  
Magnetic Field ◽  
Theoretical Model ◽  
Ngc 6946 ◽  
The Magnetic Field

The Comparison of Magnetic Leakage of Different Teeth Structures in Magnetic Fluid Seal

2011 ◽  
Vol 197-198 ◽  
pp. 314-317 ◽  
Author(s):  
Fei Fei Xing ◽  
De Cai Li ◽  
Wen Ming Yang ◽  
Xiao Long Yang
Keyword(s):  
Magnetic Field ◽  
Finite Element Method ◽  
Finite Element ◽  
Theoretical Model ◽  
Field Distribution ◽  
Magnetic Fluid ◽  
Magnetic Field Distribution ◽  
Two Sides ◽  
The Magnetic Field ◽  
Sealing Gap

Based on the theoretical model, magnetic field distribution of rectangular teeth, two-sides dilated shape and one-side dilated shape teeth structure with common other conditions were calculated using finite element method when the sealing gap was 0.1mm and 0.12mm. The comparison of their results with the same sealing gap showed that rectangular teeth structure had the highest magnetic leakage. Moreover, the magnetic field distribution of sealing structures with rectangular stages on both the shaft and pole pieces under the same design and sealing gap were also calculated using the same method, whose result was compared with rectangular stages on pole pieces only. The comparison showed that the former did not have higher pressure capability obviously but led to higher magnetic leakage.

scholarly journals A theoretical model of torsional oscillations from a flux transport dynamo model

2010 ◽  
Vol 6 (S273) ◽  
pp. 366-368
Author(s):  
Piyali Chatterjee ◽  
Sagar Chakraborty ◽  
Arnab Rai Choudhuri
Keyword(s):  
Magnetic Field ◽  
Theoretical Model ◽  
Lorentz Force ◽  
High Latitude ◽  
Torsional Oscillation ◽  
Sunspot Cycle ◽  
Dynamo Model ◽  
Flux Transport ◽  
Torsional Oscillations ◽  
The Magnetic Field

AbstractAssuming that the torsional oscillation is driven by the Lorentz force of the magnetic field associated with the sunspot cycle, we use a flux transport dynamo to model it and explain its initiation at a high latitude before the beginning of the sunspot cycle.

A model for the texture development of high-Tc superconductors under an elevated magnetic field

1999 ◽  
Vol 14 (7) ◽  
pp. 2751-2763 ◽  
Author(s):  
P. J. Ferreira ◽  
H. B. Liu ◽  
J. B. Vander Sande
Keyword(s):  
Magnetic Field ◽  
Theoretical Model ◽  
Melt Processing ◽  
High Tc Superconductors ◽  
High Tc ◽  
Grain Alignment ◽  
Grain Rotation ◽  
Stages Of Growth ◽  
Intermediate States ◽  
The Magnetic Field

A theoretical model is proposed to explain the degree of texture achieved in high-Tc superconductors during melt-processing under an elevated magnetic field. The degree of grain alignment is quantified through a factor F which is defined as ranging from 0 (random alignment) to 1 (completely oriented). Intermediate values of F clearly characterize intermediate states of alignment in which there is still some tendency for the grains to align their c axes with the magnetic field. The model suggests that the enhancement in texture is primarily obtained through grain rotation during the early stages of grain growth from the liquid. At the later stages of growth, grains interact with each other, which hinders the phenomena of magnetic-field–induced grain alignment.

On the Equilibrium of a Linear Extrap Pinch

1982 ◽  
Vol 37 (8) ◽  
pp. 769-779 ◽  
Author(s):  
B. Lehnert
Keyword(s):  
Magnetic Field ◽  
Theoretical Model ◽  
Heat Balance ◽  
Plasma Column ◽  
Transverse Magnetic ◽  
Substantial Effect ◽  
Linear Dimensions ◽  
Axial Heat ◽  
The Magnetic Field ◽  
Linear Plasma

The equilibrium is studied of a pinched linear plasma column of “Extrap” type which is confined in a purely transverse magnetic field, partly arising from currents in a set of external conductor rods being introduced for stabilizing purposes. The axial and transverse losses are separated in a simplified theoretical model for which stability is assumed as a working hypothesis and anomalous transport as well as impurity radiation are neglected. Then, the reduction of the axial heat transport by the magnetic field will have a substantial effect on the over-all heat balance, thus leading to high temperatures at large axial lengths of the plasma column. Conditions near ignition should become possible at technically realistic linear dimensions and pinch currents

Ring formation in electromagnetic beams propagating in a magnetoplasma

2009 ◽  
Vol 75 (6) ◽  
pp. 769-785 ◽  
Author(s):  
SHIKHA MISRA ◽  
S. K. MISHRA
Keyword(s):  
Magnetic Field ◽  
Steady State ◽  
Theoretical Model ◽  
Ring Formation ◽  
Paraxial Approximation ◽  
Electromagnetic Beam ◽  
Self Focusing ◽  
Self Consistent ◽  
Electromagnetic Beams ◽  
The Magnetic Field

AbstractThis paper presents an analysis (in the paraxial approximation) of a self-consistent, steady-state, theoretical model, which explains the ring formation in a Gaussian electromagnetic beam propagating in a magnetoplasma, characterized by ponderomotive and collisional nonlinearities. The condition for the formation of a dark and a bright ring has been derived analytically and the focusing/defocusing of the beam has been investigated in the different regimes. Further, the effect of the magnetic field and the nature of the nonlinearity on the ring formation and self focusing of the beam have also been explored.

On the spreading of impacting drops under the influence of a vertical magnetic field

2016 ◽  
Vol 809 ◽  
Author(s):  
Jie Zhang ◽  
Tian-Yang Han ◽  
Juan-Cheng Yang ◽  
Ming-Jiu Ni
Keyword(s):  
Magnetic Field ◽  
Theoretical Model ◽  
Contact Angles ◽  
Vertical Magnetic Field ◽  
Joule Dissipation ◽  
Spreading Factor ◽  
Dissipation Energy ◽  
Capillary Effects ◽  
The Magnetic Field ◽  
Maximum Spreading

A theoretical model is developed to predict the maximum spreading of liquid metal drops when impacting onto dry surfaces under the influence of a vertical magnetic field. This model, which is constructed based on the energy conversion principle, agrees very well with the numerical results, covering a wide range of impact speeds, contact angles and magnetic strengths. When there is no magnetic field, we found that the maximum spreading factor can be predicted well by an interpolating scheme between the viscous and capillary effects, as proposed by Laan et al. (Phys. Rev. Appl., vol. 2 (4), 2014, 044018). However, when gradually increasing the magnetic field strength, the induced Lorentz forces are dominant over the viscous and capillary forces, taking the spreading behaviour into the ‘Joule regime’, where the Joule dissipation is significant. For most situations of practical interest, namely when the strength of the magnetic field is less than 3 T, all three energy conversion routes are important. Therefore, we determine the correct scaling behaviours for the magnetic influence by first equating the loss of kinetic energy to the Joule dissipation in the Joule regime, then by interpolating it with the viscous dissipation and the capillary effects, which allows for a universal rescaling. By plotting the numerical results against the theoretical model, all the results can be rescaled onto a single curve regardless of the materials of the liquid metals or the contact angles of the surfaces, proving that our theoretical model is correct in predicting the maximum spreading factor by constructing a balanced formula between kinetic energy, capillary energy, viscous dissipation energy and Joule dissipation energy.

scholarly journals Polarized Radio Emission from NGC 6946

1990 ◽  
Vol 140 ◽  
pp. 213-214
Author(s):  
R. Beck ◽  
U.R. Buczilowski ◽  
J.I. Harnett
Keyword(s):  
Magnetic Field ◽  
Star Formation ◽  
Radio Emission ◽  
Large Scale ◽  
Star Formation Rate ◽  
Formation Rate ◽  
Uniform Field ◽  
Complicated Structure ◽  
Ngc 6946 ◽  
The Magnetic Field

New VLA radio observations of NGC 6946 reveal a complicated structure of the magnetic field with possibly radial changes in the foreground Faraday rotation, the strength of the uniform field and the particular dynamo mode in operation. The uniform field is strongest in the interarm regions, but shows no deducible large-scale structure in the radius range of the optical spiral arms. The high star formation rate in NGC 6946 apparently increases the turbulence of the interstellar magnetic field.

INFLUENCE OF LONGITUDINAL MAGNETIC FIELD ON THE FLUCTUATION CONDUCTIVITY IN SLIGHTLY Al-DOPED YBa2Cu3-zAlzO7-δ SINGLE CRYSTALS WITH A GIVEN TOPOLOGY OF PLANE DEFECTS

2011 ◽  
Vol 25 (27) ◽  
pp. 2131-2136 ◽  
Author(s):  
R. V. VOVK ◽  
M. A. OBOLENSKII ◽  
A. A. ZAVGORODNIY ◽  
Z. F. NAZYROV ◽  
I. L. GOULATIS ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Electrical Conductivity ◽  
Theoretical Model ◽  
Liquid Phase ◽  
Temperature Dependence ◽  
Single Crystals ◽  
Constant Magnetic Field ◽  
Longitudinal Magnetic Field ◽  
Fluctuation Conductivity ◽  
The Magnetic Field

In this work we study the influence of the constant magnetic field up to 14 kOe to the temperature dependence of the electrical conductivity in the ab-plane of aluminium doped YBa 2 Cu 3 O 7-δ single crystals with an unidirectional twin boundaries system. The temperature dependence of the excess para-conductivity is interpreted within the Aslamazov–Larkin theoretical model of the fluctuation conductivity. It was shown that the lack of fan-shaped expansion of the resistive transitions in the magnetic field in these samples may be due to the lack of the non-pinning vortex liquid phase.

scholarly journals A Theoretical Model for the Convection of Magnetic Flux in and near Sunspots

1974 ◽  
Vol 56 ◽  
pp. 235-237
Author(s):  
F. Meyer ◽  
H. U. Schmidt ◽  
N. O. Weiss ◽  
P. R. Wilson
Keyword(s):  
Magnetic Field ◽  
Theoretical Model ◽  
Magnetic Flux ◽  
Rapid Growth ◽  
Initial Phase ◽  
Convection Zone ◽  
Deep Convection ◽  
Flux Rope ◽  
Physical Processes ◽  
The Magnetic Field

In this paper we investigate the physical processes that lead to the growth and decay of magnetic flux in and near sunspots.An initial phase of rapid growth is characterized by the emergence of magnetic flux from the deep convection zone. As the flux rope rises through the surface the magnetic field is swept to the junctions of the supergranular network where sunspots are formed. These flux concentrations follow the footpoints of the emergent flux rope as they rapidly move apart.

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