2014 We have calculated numerically the current distribution of a two-dimensional Josephson junction network in a magnetic field. At the percolation threshold and in the approximation of linear junctions this distribution is multifractal. We have also considered the lowest order nonlinear corrections to the diamagnetic susceptibility. This correction scales with one of the exponents of the mult...

Turbulent convection in the solar photosphere can act as a small-scale dynamo, maintaining a disordered magnetic field that is locally intense. On the other hand, convection is inhibited in the presence of a strong, externally imposed magnetic field, as for instance, in a sunspot. Large-scale, three-dimensional, numerical experiments on highly nonlinear magnetoconvection in a Boussinesq fluid s...

Aims. Nonlinear behaviour of galactic dynamos is studied, allowing for magnetic helicity removal by the galactic fountain flow. Methods. A suitable advection speed is estimated, and a one-dimensional mean-field dynamo model with dynamic α-effect is explored. Results. It is shown that the galactic fountain flow is efficient in removing magnetic helicity from galactic discs. This alleviates the c...

The evolution and viscous damping of cosmic magnetic fields in the early universe, is analysed. Using the fact that the fluid, electromagnetic, and shear viscous energy-momentum tensors are all conformally invariant, the evolution is transformed from the expanding universe setting into that in flat spacetime. Particular attention is paid to the evolution of nonlinear Alfvén modes. For a small e...

A common method for measuring the electromagnetic properties of superconductors is to measure their complex magnetic ac susceptibility χ as a function of frequency ω and amplitude H0, and of temperature T and applied dc magnetic field H dc a as parameters. The basic theory of the linear χ(ω) and nonlinear χ(H0, ω) is outlined for various geometries, e.g. disks, rings, and strips of thin films o...

We analyze the properties of microstructured materials with negative refraction, the so-called left-handed metamaterials. We consider a two-dimensional periodic structure created by arrays of wires and split-ring resonators embedded into a nonlinear dielectric, and calculate the effective nonlinear electric permittivity and magnetic permeability. We demonstrate that the hysteresis-type dependen...

in order to study the effects of magnetic field, silver nano particles and micronutrient fertilizers on sugar beet, an experiment was conducted at razavi research and technology institute, mashhad, iran. experiment carried out with seven treatments based on randomized complete block design with three replications. treatments included (t1) magnetic field and silver nano particles + kemira fertil...

introduction increase in alpha band is observed when blood perfusion in frontal area of head decreases. the present study evaluated some changes in the alpha band particularly, alpha-1 of frontal and central areas of the head, when several areas were exposed simultaneously to magnetic field. materials and methods five points of head (f3, f4, cz, t3, and t4) of twenty healthy male participants w...

this study is considering a micropolar fluid flow over a porous stretching sheet in the presence of thermal radiation and uniform magnetic field. the effects of local variation in thermal conductivity of micropolar fluid on heat transfer rate from the sheet are investigated; besides, the impacts of radiation, magnetic field and porous sheet on variations of thermal boundary layer thickness are ...

background : electromagnetic fields are associated with production, transmission and use of electricity. in this  tudy we have investigated the effects of short and long time alternative magnetic fields' (amf, 50 hz) exposure on the secretion of hypothalamic-pituitary-gonadal axis in the male rats. methods : forty eight wistar male rats, same range of age and weight were divided into four group...