Recent analytical and computational advances in the theory of large-scale dynamos are reviewed. The importance of the magnetic helicity constraint is apparent even without invoking mean-field theory. The tau approximation yields expressions that show how the magnetic helicity gets incorporated into mean-field theory. The test-field method allows an accurate numerical determination of turbulent ...

In this research, using the Modified Compression Field Theory (MCFT), a new model is proposed to predict the behavior of reinforced concrete coupling beams. The model is able to consider the effects of shear and axial forces and bending moment, simultaneously. The proposed model includes a nonlinear shear spring, an axial spring and some nonlinear springs for considering bending deformations. I...

The complete 3D nonlinear dynamic problem of extensible, flexible risers conveying fluid is considered. For describing the dynamics of the system, the Newtonian derivation procedure is followed. The velocity field inside the pipe formulated using hydrostatic and Bernoulli equations. The hydrodynamic effects of external fluids are taken into consideration through the nonlinear drag forces in var...

We develop a theory of nonlinear response to an electric field of a two-dimensional electron gas 2DEG placed in a classically strong magnetic field. The latter leads to a nonlinear current-voltage characteristic at a relatively weak electric field. The origin of the nonlinearity is twofold: the formation of a nonequilibrium electron distribution function and the geometrical resonance in the int...

The derivative expansion of the Wilsonian renormalization group generates additional terms in the effective β-functions not present in the perturbative approach. Applied to the nonlinear σ model, to lowest order the vanishing of the β-function for the tachyon field generates an equation analogous to that found in open string field theory. Although the nonlinear term depends on the cut-off funct...

The derivative expansion of the Wilsonian renormalization group generates additional terms in the effective β-functions not present in the perturbative approach. Applied to the nonlinear σ model, to lowest order the vanishing of the β-function for the tachyon field generates an equation analogous to that found in open string field theory. Although the nonlinear term depends on the cut-off funct...

Abstract Particlelike solutions in SU(3) gauge Yang–Mills theory with color magnetic and electric fields sourced by a nonlinear spinor field are obtained. The asymptotic behavior of these is studied. It shown that the exhibits Coulomb behavior, one components behaves asymptotically as dipole. This allows to determine corresponding charge moment. profiles moment have global minima, which may be ...

in the present study an alternative model allows the extension of the debye-hückel theory (dht) considering time dependence explicitly. from the electro-quasistatic approach (eqs) done in earlier studies time dependent potentials are suitable to describe several phenomena especially conducting media as well as the behaviour of charged particles in arbitrary solutions acting as electrolytes.this...