This article presents an exact solution for an axisymmetric functionally graded piezoelectric (FGP) rotating disk with constant thickness subjected to an electric field and thermal gradient. All mechanical, thermal and piezoelectric properties except for Poisson’s ratio are taken in the form of power functions in radial direction. After solving the heat transfer equation, first a symmetric dist...

A white sector on a black rotating disk appears spatially compressed. We found that apparent shrinkage: (1) for sectors ranging from 15 to 150 degrees and rotating at 1.25 rps varied in an inverted U-shaped manner from 3 to 16 degrees and back to 11 degrees (corresponding to 20, 16, and 7.5%, respectively); (2) increased with speed of rotation producing maximal compressions of between 7 and 30 ...

Abstract— This note deals with the stabilization problem of a rotating disk with a flexible beam attached to its center. Assuming that a torque control is applied on the disk and a shear force control is exerted at the free end of the beam, we end up with a nondissipative closed loop system. We prove that the system can be nonuniformly exponentially stabilized provided that the angular velocity...

Rings are common in disk galaxies. These rings are either indistinguishable from a pair of tightly wound spirals, or themselves are a part of the spiral structure. Furthermore, their occurrence is seen coincident with a bar in the center. In this paper, we interpret this spiral-ring structure as density waves resonantly excited by a rotating bar potential. The theory gives excellent agreement f...

When some magnetic field lines connect a Kerr black hole with a disk rotating around it, energy and angular momentum are transferred between them. If the black hole rotates faster than the disk, ca&solm0;GMH>0.36 for a thin Keplerian disk, then energy and angular momentum are extracted from the black hole and transferred to the disk (MH is the mass and aMH is the angular momentum of the black h...

We present the first results from fully general relativistic numerical studies of thick-disk accretion onto a rapidly-rotating (Kerr) black hole with a spin axis that is tilted (not aligned) with the angular momentum vector of the disk. We initialize the problem with the solution for an aligned, constant angular momentum, accreting thick disk around a black hole with spin a/M = J/M = +0.9 (prog...

In order to adapt to the requirements of the development for precision agriculture technology, making the rice seed tape planting technology has been widely used. The paper-making improved the design on the rice seed tape twisting machine especially the seed tape winding units. It proposed seed tape winding automatic control system based on STC90C514AD to realize the rotating speed adjustment o...

This paper presents a fundamental numerical analysis of flow and heat transfer in a vertical rotating disk reactor. These reactors are commonly used for growing thin films via chemical vapor deposition. Under certain conditions, rotating disk reactors have been found to exhibit multiple steady states, where desirable and undesirable flow patterns co-exist at the same conditions. The focus of th...

The present study is carried out to investigate the magneto-viscous effects on incompressible ferrofluid flow over a porous rotating disc with suction or injection on the surface of the disc subjected to a magnetic field. The flow under consideration is axi-symmetric steady ferrofluid flow of electrically non-conducting fluid. Karman’s transformation is used to convert the governing boundary la...

We report the formation of a ringlike structure in the flow of particular non-Newtonian liquids coating a rotating vertical disk. Experiments were performed with a known volume of the liquid and at varying rotation rates such that the inertial effects were negligible. The liquid injected on the rotating disk initially coats the surface uniformly, which then redistributes itself such that at ste...