In this paper the behavior (break-up and creation) of a magnetic fluid bridge between two coaxial cylinders in a magnetic field of a line
conductor for any values of wetting angles of a magnetic fluid is investigated.
Monte Carlo and series expansion data for the energy, specific heat, magnetisation and susceptibility of the 4-state Potts model in the vicinity of the critical point are analysed. The role of logarithmic corrections is discussed. Estimates of universal ratios A+/A−,Γ+/ΓL,ΓT/ΓL and are given.
The dynamics of ideal ferrofluids with internal rotation and frozen-in magnetization is discussed on the basis of Poisson brackets method. The magnetization relaxation equation is derived from requirement of irreversible thermodynamics that the local rate of entropy production is positive for arbitrary field deficiency.