According to recent simulations, the coalescence of two spinning black holes (BHs) could lead to a BH remnant with recoil speeds of up to thousands of km s(-1). Here we examine the circumstances resulting from a gas-rich galaxy merger under which the ejected BH would carry an accretion disk and be observable. As the initial BH binary emits gravitational radiation and its orbit tightens, a hole ...

The inner parts of an accretion disk around a spinning black hole are forced to align with the spin of the hole by the Bardeen-Petterson effect. Assuming that any jet produced by such a system is aligned with the angular momentum of either the hole or the inner disk, this can, in principle provide a mechanism for producing steady jets in AGN whose direction is independent of the angular momentu...

Mobile computers typically spin down their hard disk after a fixed period of inactivity. If this threshold is too long, the disk wastes energy; if it is too short, the delay due to spinning the disk up again frushates the user. Usage patterns change over time, so a single fixed threshold may not be appropriate at all times. Also, different users may have varying priorities with respect to tradi...

The main challenge in the design of hard-disk drives is to increase the density of data storage. Traditional disk-drive designs involve a read/write head positioned on a slider bearing that flies over a smooth spinning magnetic disk. The demand for larger data storage has made it necessary to reduce the minimum gap height for various design features of the air-bearing surface to be in the range...

We evolve high-mass disks of mass $15$-$50M_\odot$ orbiting a $50M_\odot$ spinning black hole in the framework numerical relativity. Such systems could be an outcome during collapse rapidly-rotating very-massive stars. The massive are dynamically unstable to so-called one-armed spiral-shape deformation with maximum fractional density-perturbation $\delta \rho/\rho \gtrsim 0.1$, and hence, high-...

Centrifugal microfluidic systems utilize a conventional spindle motor to automate parallel biochemical assays on a single microfluidic disk. The integration of complex, sequential microfluidic procedures on these platforms relies on robust valving techniques that allow for the precise control and manipulation of fluid flow. The ability of valves to consistently return to their former conditions...