Using two-dimensional hydrodynamical simulations, we followed the evolution of a dynamically-collapsing, rotating disk permeated by vertical magnetic eld. As a model of a disk, the similarity solution for isothermal, rotating, and magnetized disks are adopted. The disk deforms into a bar during its contraction. In the early stage, the deformation of the disk grows in proportion to (t 0 t) 0:6 ,...

We present a pseudo-Newtonian potential for accretion disk modeling around rotating black holes. This potential can describe the general relativistic effects in accretion disk properly. As the inclusion of rotation in a proper way is very important at the inner edge of the disk we derived our potential starting from the Kerr metric. This potential can reproduce all the essential properties of g...

This work is devoted to the experimental study of the transition to turbulence of a flow confined in a narrow gap between a rotating and a stationary disk. The experimental device, presented in Figure 1, consists of a water-filled cylindrical casing in which the rotating disk is immersed. The top lid of the container plays the role of the stationary disk. The radius of the stainless steel disk ...

Aims. To detect line effects using spectropolarimetry in order to find evidence of rotating disks and their respective symmetry axes in T Tauri stars. Methods. We used the IAGPOL imaging polarimeter along with the Eucalyptus-IFU to obtain spectropolarimetric measurements of the T Tauri stars RY Tau (two epochs) and PX Vul (one epoch). Evidence of line effects showing a loop on the Q−U diagram f...

We present kinematic measurements of the thick and thin disks in two edge-on galaxies. We have derived stellar rotation curves at and above the galaxies’ midplanes using Ca ii triplet features measured with the GMOS spectrograph on Gemini North. In one galaxy, FGC 1415, the kinematics above the plane show clear rotation that lags that of the midplane by ∼20-50%, similar to the behavior seen in ...

Following stepping in-place on the surface of a rotating circular treadmill, a subject attempting to step in-place or walk in a straight line across the floor without vision will rotate relative to space. This adaptation, termed podokinetic after-rotation (PKAR), transfers to backward walking following forward walking on the rotating disk. We asked whether adaptation obtained during stepping in...

in order to simulate the rotating disk contactor all hydrodynamic parameters, dispersed phase hold-up, characteristic velocity, mean drop size, drop size distribution, axial mixing and mass transfer have been taken into account. mechanisms of mass transfer (stagnant, circulating, oscillating drops) were used in this study. column height found from effect of mean drop size and drop size distribu...

The latest studies of massive star evolution indicate that an initially rapidly rotating star with sufficiently low metallicity can produce a rapidly rotating, massive stellar core that could be a progenitor of long-soft gamma-ray bursts (LGRBs). Motivated by these studies, we follow the collapse of a rapidly rotating massive stellar core to a ’collapsar’ black hole (BH) surrounded by a massive...

The discrete kinetic model is used to study the propagation of sound waves in system of hard-disk-like rotating stars (or vortex gases). The anomalous (negative) attenuation or amplification which is possibly due to the binary collision of a dilute-enough rotating disk (or vortex-gas) system (each with opposite-sign rotating direction or angular momenta but the total (net) angular momenta or vo...