Exact Solution for the Electromagnetic Field Excited by a Pulsed Filamentary Electric Current in a Nonlinear Nondispersive Medium

In this essay we introduce a new Hamiltonian which represents the interaction between a three-level atom and a single electromagnetic field including arbitrary forms of nonlinearities of both the field and the intensity-dependent coupling. We derive an exact solution for the density operator of the system by means of which we study the field purity for the entangled state of the system. Also, the influences of the nonlinearities on the field purity and mean photon number are examined. Under the condition of an initial coherent field, the field purity shows the collapse-revival phenomenon. It is found that features of these phenomenon are sensitive to the changes of different kinds of the nonlinearities.

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Effects of Electromagnetic Filling Parameters on Density of Al-Si Alloy in Low Pressure Casting

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.403-408.3291 ◽

2011 ◽

Vol 403-408 ◽

pp. 3291-3294

Author(s):

Shao Long Wu ◽

Yu Xing Wang

Keyword(s):

Electromagnetic Field ◽

Electric Current ◽

Low Pressure ◽

Influential Factors ◽

Pressure Casting ◽

Cyclic Time ◽

Low Pressure Casting

Effects of electromagnetic filling parameters on Density of Al-Si alloy in low pressure casting were investigated. The key influential factors on Density of Al-Si Alloy were determined by orthogonal testing. The results show that the influential orders of electric current, magnetic inductivity and cyclic time on the density of the ZL114 alloy are as follows: electric current, then magnetic inductivity, and then cyclic time. Electric current and electromagnetic field can effectively improve the density of the ZL114 alloy in low pressure casting.

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The motion of a charged black hole in an electromagnetic field

Proceedings of the Royal Society of London Series A - Mathematical and Physical Sciences ◽

10.1098/rspa.1980.0089 ◽

1980 ◽

Vol 371 (1746) ◽

pp. 429-438 ◽

Cited By ~ 17

Keyword(s):

Exact Solution ◽

Black Hole ◽

Electromagnetic Field ◽

Approximate Solution ◽

Electric Field ◽

Hamiltonian Formalism ◽

Charged Black Hole ◽

Uniform Electric Field ◽

Inertial Observer ◽

Gravitational Perturbations

The motion of a charged black hole in a weak, asymptotically uniform electric field is analysed by using the Hamiltonian formalism for coupled electromagnetic and gravitational perturbations of the Reissner-Nordstrom space-time. The hole is shown to accelerate with respect to a distant inertial observer according to Newton’s law. The relation of the approximate solution obtained to the exact solution of Ernst, representing the charged C-metric without nodal singularity, is then clarified.

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The Vectorial Nature of Electric Current: Modification of Maxwell?s Equation of the Electromagnetic Field

IEEE Potentials ◽

10.1109/mpot.2012.2228341 ◽

2013 ◽

Vol 32 (2) ◽

pp. 24-26

Author(s):

Pramode Ranjan Bhattacharjee

Keyword(s):

Electromagnetic Field ◽

Electric Current

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Fluid motions induced by an electric current discharge

Proceedings of the Royal Society of London Series A - Mathematical and Physical Sciences ◽

10.1098/rspa.1972.0101 ◽

1972 ◽

Vol 329 (1576) ◽

pp. 71-81 ◽

Cited By ~ 13

Keyword(s):

Electromagnetic Field ◽

Flow Field ◽

Electric Current ◽

Kinematic Viscosity ◽

Conducting Fluid ◽

Total Current ◽

Fluid Density ◽

Current Discharge ◽

Monotonically Increasing Function ◽

Increasing Function

In this paper we consider the flow field induced by an electric current discharge emerging from a small hole (mathematically a point) of a plane wall, bounding an incompressible viscous conducting fluid. The current is directed radially from the discharge. In earlier work, where the effect of the velocity on the electromagnetic field was neglected, it was shown that the velocity field contains singularities, and therefore the solution breaks down, when K = 2 J 2 0 / πρv 2 > K crit ≈ 300.1. Here J 0 is the total current of the discharge, ρ the fluid density and v the coefficient of kinematic viscosity. It is found that for a finitely conducting fluid when account is taken of the effect of the velocity on the electromagnetic field, K crit is a monotonically increasing function of α = 4 πvσ where σ is the electrical conductivity of the fluid. The interaction of this flow field with that due to a jet or sink of momentum, emerging from the same hole as the electric current discharge, is also considered in some detail.

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