Solar flare accelerates nearly all electrons in a large coronal volume.

Solar flares, driven by prompt release of free magnetic energy in the solar corona, are known to accelerate a substantial portion (ten per cent or more) of available electrons to high energies. Hard X-rays, produced by high-energy electrons accelerated in the flare, require a high ambient density for their detection. This restricts the observed volume to denser regions that do not necessarily sample the entire volume of accelerated electrons.

Decay of the coronal magnetic field can release sufficient energy to power a solar flare.

Solar flares are powered by a rapid release of energy in the solar corona, thought to be produced by the decay of the coronal magnetic field strength. Direct quantitative measurements of the evolving magnetic field strength are required to test this. We report microwave observations of a solar flare, showing spatial and temporal changes in the coronal magnetic field.

DeltaE effect for polycrystalline ferromagnetic rods.

We performed experimental and computational studies of the acoustic transfer power coefficient for carbon steel cylindric bars placed in axial magnetic field. By experiment, the transmission coefficients of velocity were measured for ferromagnetic bars during the first magnetization curve below saturation. Using the magnetic and magnetostriction material measurements we obtained the profile of the magnetostriction along the distance for a ferromagnetic cylindrical rod placed in a magnetic field parallel with its axis.

Collapse of transient nucleation fluxes in a cold Ising ferromagnet.

We report the time-dependent nucleation fluxes and associated nucleation rates in a metastable Ising ferromagnet on square lattice with Metropolis (Glauber-type) dynamics. It is discovered that, with lowering of the temperature, fluxes collapse into several representative transient curves corresponding to magic cluster sizes. Those can be associated with physical droplets, i.

On the critical cluster in the two-dimensional Ising model: computer-assisted exact results.

For a nearest-neighbor Ising model on a square lattice all cluster configurations with 17 or fewer spins are identified. In neglect of cluster-cluster interactions, critical sizes and barriers to nucleation are obtained as functions of temperature and magnetic field for two alternative definitions of a "critical cluster."

Nucleation preexponential in dynamic Ising models at moderately strong fields.

A dynamic Ising model on a two-dimensional square lattice with nearest neighbor interactions is considered in the metastable region at low temperatures. A large number of low-energy cluster configurations is identified, and for those configurations a system of kinetic equations is written. Solution is obtained using symbolic computational approaches.

Modulation of the nucleation rate preexponential in a low-temperature Ising system.

A metastable lattice gas with nearest-neighbor interactions and continuous-time dynamics is studied using a generalized Becker-Döring approach in the multidimensional space of cluster configurations. The preexponential of the metastable-state lifetime (inverse of nucleation rate) is found to exhibit distinct peaks at integer values of the inverse supersaturation. Peaks are unobservable (infinitely narrow) in the strict limit T-->0, but become detectable and eventually dominate at higher temperatures.