We present VLBA observations of the H2O masers towards IRAS 20126+4104, a high-mass young stellar object which is believed to be associated with a rotating disk and a bipolar outflow/jet system collimated along the disk axis. A model fit to the positions and velocities of the maser spots demonstrates that these could arise on a conical surface at the interface between the jet and the surroundin...

Friction drilling Process is a rotating conical tool to penetrate the work piece and create a bushing in a single step without generating chips. This work investigates the finite element modeling (FEM) of large plastic strain and high-temperature work-material deformation in friction drilling. The workmaterial deformation is very large, and both the tool and work piece temperatures are high in ...

We find that the recently introduced model of self-trapping supported by a spatially growing strength of a repulsive nonlinearity gives rise to robust vortex-soliton tori, i.e., three-dimensional vortex solitons, with topological charges S≥1. The family with S=1 is completely stable, while the one with S=2 has alternating regions of stability and instability. The families are nearly exactly rep...

We present VLBI observations of 6.7 and 12.2 GHz methanol masers in the star forming region NGC7538. Our results show the existence of two groups of masers. The first group exhibits a linear velocity gradient and forms a line in our VLBI map which is consistent with a rotating disc of masers seen edge-on around a massive star. The second group of masers are blueshifted with respect to the first...

The aim of this paper is to study the cyclone-like flow inside a hydrodynamic mixer experimentally, with a special emphasis on the differences in the flow field in the case of Newtonian and non-Newtonian fluids. The mixer consists a cylindrical body with conical bottom, in which two, tangentially entering fluid jets drive the rotating motion of the fluid body. The two fluids are (1) water and (...

Friction stir lap welding (FSLW) experiment has been conducted on 3mm thick AZ80 extruded sheet and 2.3mm thick AZ31B rolled sheet. The influence of the shape of the taper thread mixing head on microstructure has been discussed. Pores forming, hooked defects, interface migration, tissue distribution have been analyzed. The organization of both sides of nugget zone (NZ) is arranged diagonally ab...

The static and stationary C-metric are revisited in a generic framework and their interpretations studied in some detail. Specially those with two event horizons, one for the black hole and another for the acceleration. We found that: i) The spacetime of an accelerated static black hole is plagued by either conical singularities or lack of smoothness and compactness of the black hole horizon; i...

Abstract We construct analytical and regular solutions in four-dimensional General Relativity which represent multi-black hole systems immersed external gravitational field configurations. The background is composed by an infinite multipolar expansion, allows to regularise the conical singularities of array collinear static black holes. A stationary rotating generalisation achieved adding indep...

First, I present two new classes of magnetic rotating solutions in four-dimensional Einstein-Maxwell-dilaton gravity with Liouville-type potential. The first class of solutions yields a 4-dimensional spacetime with a longitudinal magnetic field generated by a static or spinning magnetic string. I find that these solutions have no curvature singularity and no horizons, but have a conic geometry....