Charged rotating black holes of Einstein-Maxwell-Chern-Simons theory in odd dimensions, D ≥ 5, may possess a negative horizon mass, while their total mass is positive. This surprising feature is related to the existence of counterrotating solutions, where the horizon angular velocity Ω and the angular momentum J possess opposite signs. Black holes may further possess vanishing horizon angular v...

When a symmetric top is set spinning with angular velocity ω c about its own axis, it traces out a circle about a vertical direction with angular velocity ω z , as shown in Fig. 1. In most textbooks [1, 2, 3] the precessional angular velocity ω z is calculated under the assumption that it is much smaller than the spin angular velocity ω c . This makes for a simplification of the calculation by ...

The paper deals with the problem of angular vibration measurements in time history of rotation angle, angular velocity or angular acceleration. The source of information about angular vibrations is an encoder producing an impulse signal. It is supposed that the impulse frequency is changed proportionally to the rotational frequency. A time record of an impulse signal is transformed to an analyt...

The authors ran 3 experiments to investigate how catchers deal with the horizontal component of the ball's trajectory in an interception task during locomotion. The experiments were built upon the finding that velocity adaptations are based upon changes in the horizontal angular position or velocity of the ball with respect to the observer (M. Lenoir, M. Janssens, E. Musch, E. Thiery, J. Uytten...

The attitude tracking control problem of uncertain rigid spacecraft without angular velocity measurements is addressed in this paper. The adaptive control law, which incorporates a velocity-generating filter from attitude measurements, is shown to ensure the asymptotic convergence of the attitude and angular velocity tracking errors despite unknown spacecraft inertia. Simulation results are pre...

The flow in an elastico-viscous fluid between two co-axial infinite rotating porous discs is considered for high cross flow Reynolds number. The discs are rotating with different angular velocity and the injection rate of the fluid at one disc is different from the suction rate of other disc. The effect of suction parameters on the velocity components have been investigated numerically and solv...