Formation of a rotating jet during the filament eruption on 10-11 April 2013

We analyze multi-wavelength and multi-viewpoint observations of a helically twisted plasma jet formed during a confined filament eruption on 10-11 April 2013. Given a rather large scale event with its high spatial and temporal resolution observations, it allows us to clearly understand some new physical details about the formation and triggering mechanism of twisting jet. We identify a pre-existing flux rope associated with a sinistral filament, which was observed several days before the event. The confined eruption of the filament within a null point topology, also known as an Eiffel tower (or inverted-Y) magnetic field configuration results in the formation of a twisted jet after the magnetic reconnection near a null point. The sign of helicity in the jet is found to be the same as that of the sign of helicity in the filament. Untwisting motion of the reconnected magnetic field lines gives rise to the accelerating plasma along the jet axis. The event clearly shows the twist injection from the pre-eruptive magnetic field to the jet.Comment: 14 pages, 12 figures, to appear in MNRA

Simulation of three-dimensional micromagnetic structures in magnetically uniaxial films with in-plane anisotropy. Dynamics and structural reconstructions

Transition processes in nonequilibrium micromagnetic structures that represent regions of various types of asymmetrical vortex domain walls with closely spaced transition structural elements, including vertical Bloch lines (VBLs), singular points, and clusters consisting of VBLs and singular points, have been studied by the method of three-dimensional numerical simulation of the magnetization behavior. The realization of various scenarios of dynamic behavior, including the annihilation of transition elements accompanied by the liberation of energy and the initiation of wave processes, has been shown to be possible. The simulation was performed for the case of magnetically uniaxial ferromagnetic films with an easy axis parallel to their surface with exact allowance for the inhomogeneous exchange, magnetoanisotropic, and magnetostatic interactions. © 2013 Pleiades Publishing, Ltd

Axisymmetric Vibrations of Thin Shells of Revolution Joint at a Small Angle

  &nbsp

Two-dimensional micromagnetic simulation of domain structures in films with combined anisotropy

The transformation of the domain structure of micrometer-thick films with variations in the induced uniaxial anisotropy constant with the easy magnetization axis perpendicular to the film surface has been investigated using numerical micromagnetic simulation in the framework of a two-dimensional model of the magnetization distribution. The case where the tetra-axial crystallographic anisotropy exists in the film with uniaxial magnetic anisotropy has been considered. The transformation of the open domain structure into the structure with a magnetic flux closed inside the sample has been investigated in detail, and new types of 109-degree and 90-degree vortex-like domain walls and periodic domain structures have been obtained. © 2013 Pleiades Publishing, Ltd

Free Vibrations and Buckling of a Thin Cylindrical Shell of Variable Thickness with Curvelinear Edge

Low-frequency vibrations and buckling under an uniform external lateral pressure of a thin cylindrical shell of variable thickness with curvelinear edge are analyzed. The asymptotic and finite element methods are used to get the vibration frequencies and critical loads. The vibration and buckling modes are also presented. The comparison of numerical and asymptotic results is performed

Cutting Edge Geometry Effect on Plastic Deformation of Titanium Alloy

The paper presents experimental studies of ОТ4 titanium alloy machining with cutting edges of various geometry parameters. Experiments were performed at a low speed by the scheme of free cutting. Intensity of plastic shear strain was set for defining of cutting edge geometry effect on machining. Images of chip formed are shown. Estimation of strain magnitude was accomplished with digital image correlation method. Effect of rake angle and cutting edge angle has been studied. Depth of deformed layer and the area of the plastic strain is determine. Results showed that increasing the angle of the cutting edge inclination results in a change the mechanism of chip formation