The equatorial asymmetry of a magnetic field

Solution of the inverse problem for Parker’s one-dimensional mean-field dynamo model in a thin spherical layer is considered. The method allows the spatial distribution of energy sources, the α- and Ω-effects, to be found provided specified constraints occur on the solution. The highest ratio of the magnetic energies for the Northern and Southern hemispheres is discussed as such a constraint. The method is a modification of the Monte-Carlo technique; it is convenient for parallel computations and based on minimization of the cost function that characterizes the deviation of the model solution properties from the desired ones. The calculations show that the ratio of the energies in the hemispheres may exceed an order of magnitude for both poloidal and toroidal components of the magnetic energy. The ratio depends on the distance of the effective zone of the generation of the magnetic field from the equator and the number of harmonics in the spectrum. The greater this distance is and the higher the number of harmonics is, the stronger the magnetic field asymmetry can be.     

Formation and Growth of Nuclei of the Stable Crystalline Phase in a Supercooled Yukawa Liquid

Journal of Experimental and Theoretical Physics - We consider the nonequilibrium formation and growth of the stable crystalline phase in a supercooled Yukawa liquid. It is found that for the...     

Formation and dynamics of easy orientation axis in magnetic field on PVCN-F surface

We describe the experiments on a magnetically-induced drift of the easy axis on a soft surface of photoaligning material fluoro-polyvinyl-cinnamate. We found unexpected partial relaxation of the drift of the easy axis after switching the magnetic field off. This relaxation cannot be explained in a framework of the existing models and requires additional assumptions about the drift process. We propose a model that explains the experimental data suggesting elastic-like behaviour of the polymer fragments during the drift of the easy axis.     

Full Fermi–Pasta–Ulam Recurrence Interaction with Fluctuations of the Medium

It is shown in a numerical study that the simultaneous influence of discrete and continuous random processes on the full Fermi–Pasta–Ulam (FPU) recurrence dynamics in two parametrically coupled identical chains of vibrators with open ends and under different initial conditions leads to stabilization of the FPU spectrum. A greater influence on chains of gaussian noise as compared to discrete noise is revealed. An increase in the amplitudes of both noises by one order of magnitude results in considerable parameter changes in their FPU spectrum. The full FPU recurrence interaction in coupled chains with discrete and continuous random noise of the medium manifests itself in extremely low-frequency periodic processes in stochastic dynamics of the medium (with frequency two orders of magnitude lower than the lowest frequency in the initial conditions of the chains).     

On the Distribution of an Impurity and Control of its Content in the Atmosphere

On the basis of a theoretical model of propagation of a gas impurity polluting the atmosphere, formulas are obtained that relate the power of the impurity source with the impurity content when measured by a gas-correlation IR radiometer. The model takes into account transfer of the gas impurity by wind, its diffusion, and vertical motion. Requirements on the sensitivity of instrumentation are analyzed. Estimates of the possibility of remote monitoring of the atmosphere are also made.     

Electrical transport and magnetic ordering in R 2Ti3Ge4 (R=Dy, Ho and Er) compounds

New R ₂Ti₃Ge₄ (R=Dy, Ho and Er) intermetallic compounds have been synthesized and characterized by X-ray diffraction and low temperature ac magnetic susceptibility, electrical resistivity and thermoelectric power measurements were carried out. The compounds crystallize in the parent, Sm₅Ge₄-type orthorhombic structure (space group Pnma) and lanthanide contraction is observed as one moves along the rare-earth series. The changeover from paramagnetic to antiferromagnetic phase happens at low temperatures and the ordering temperature scales with the de Gennes factor. The electrical resistivity is metallic with a negative curvature above 100 K. Thermopower displays a weak maximum at temperatures less than 50 K signifying the possible phonon and magnon drag effects.