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...

The interaction between an initially laminar boundary layer developed spatially on a flat plate under the influence of vortex shedding induced from a rotating circular cylinder has been simulated numerically. The rotational speed of the cylinder is varied to generate the vortex shedding of different intensities. Also the flat plate is kept at different positions from the cylinder. Due to asymme...

PURPOSE To determine the refractive cylinder effect of rotating a toric intraocular lens (IOL) and identify the sources of refractive astigmatic surprise after toric IOL implantation. SETTING Private practice, Melbourne, Australia. DESIGN Experimental study. METHODS Vergence formulas using a standard reduced eye model were used to bring all lens powers to the corneal plane. Double-angle v...

The flow of dilute suspensions in a rotating filter separator consisting of a rigid, porous, polyethylene cylindrical filter rotating within an outer cylindrical shell was studied using laser-based velocity measurement techniques. The centrifugal instability of the Taylor–Couette flow results in toroidal vortices stacked in the annulus. The velocity field of the particles is very similar to tha...

In this paper Optimal Homotopy Asymptotic Method (OHAM) has been used to the flow past a rotating disk. This method is applied to the problem obtained from flow past a rotating disk shows its efficiency and effectiveness. This method control the convergence of approximate solution in a convenient way, when it is compared with other methods of solution found in the literature as Homotopy Perturb...

In this paper we study data replication in a mirrored disk system. Free disk space is exploited by keeping replicas of specific cylinders at appropriate disk locations. Assuming an organ-pipe arrangement we calculate the expected seek distance by varying the probability cylinder access under different distributions. Also, analytic formulae are derived for the expected seek distance under replic...