In a recent important paper, Papaloizou & Pringle (1984) have investigated the dynamical stability of a thick, differentially rotating disc of uniform entropy and uniform specific angular momentum. They find a strong global non-axisymmetric instability which grows on a dynamical time-scale. Here we show that a similar instability exists even in thin discs of arbitrary specific angular momentum....

The aerodynamic performance of hovering insects is largely explained by the presence of a stably attached leading edge vortex (LEV) on top of their wings. Although LEVs have been visualized on real, physically modeled, and simulated insects, the physical mechanisms responsible for their stability are poorly understood. To gain fundamental insight into LEV stability on flapping fly wings we expr...

In this paper we consider the postural stability problem for nonlinearly actuated quasi-static biped robots, both with respect to the joint angular positions and also with reference to the gripping effect between the foot/feet against the ground during robot locomotion. Zero moment point based mathematical models are developed to establish a relationship between the robot state variables and th...

fused deposition modeling (fdm) is a filament based rapid prototyping system provides us to manufacture real parts with multiple production-grade materials, such as abs-m30, pc, ppsf and pc-abs blend. fused deposition modeling technology, essentially perform using layer manufacturing process. more complex 3d physical models can be efficiently fabricated without geometric limitation by this tech...

Description Simulation of the transient stability problem, which is the assessment of the short term (several to 30 seconds) angular and voltage stability of the power system following a disturbance, is of vital importance. For some portions of the North American power grids, such as the Western Electric Coordinating Council (WECC), transient stability has always been an important consideration...

In this paper, we propose a miniaturized 2.5-dimensional (2.5D) frequency selective surface (FSS) structure with high angular stability. A novel closed-loop FSS is formed by combining the Jerusalem cross (JC) conventional rectangular closed loop using vias. This approach further enhances coupling performance of and thus achieves design. The unit cell size proposed 0.019λ0 × at resonant frequenc...

In this letter, a Jaumann-like rasorber is examined, which offers wideband absorption, angular stability, and polarization insensitivity. The structure defined by three layers with two resistive placed on top of lossless layer. Also, all use capacitors to ensure compactness for the metasurface rasorber. These features provide broad stability up 55 <inline-formula xmlns:mml="http://www.w3.org/19...