Abstract. The limit of vanishing ratio of the electron mass to the ion mass in the isentropic transient Euler-Poisson equations with periodic boundary conditions is proved. The equations consist of the conservation laws for the electron density and current density for given ion density, coupled to the Poisson equation for the electrostatic potential. The limit is related to the low-Mach-number ...

The limit of vanishing ratio of the electron mass to the ion mass in the isentropic transient Euler-Poisson equations with periodic boundary conditions is proved. The equations consist of the conservation laws for the electron density and current density for given ion density, coupled to the Poisson equation for the electrostatic potential. The limit is related to the low-Mach-number limit of K...

The near-horizon metric for a black brane in Anti-de Sitter (AdS) space and the metric near the AdS boundary both exhibit hydrodynamic behavior. We demonstrate the equivalence of this pair of hydrodynamic systems for the sound mode of a conformal theory. This is first established for Einstein’s gravity, but we then show how the sound damping constant will be modified, from its Einstein form, fo...

For advanced aerospace propulsion systems, development of ceramic matrix composite integrally-bladed turbine disk technology is attractive for a number of reasons. The high strength-to-weight ratio of ceramic composites helps to reduce engine weight and the onepiece construction of a blisk will result in fewer parts count, which should translate into reduced operational costs. One shortcoming w...

We investigate the impulsively excited acoustic dynamics of nanoscale Au triangles of different sizes and thicknesses on silicon and glass substrates. We employ high-speed asynchronous optical sampling in order to study the damping of the acoustic vibrations with high sensitivity in the time domain. From the observed damping dynamics we deduce the reflection coefficient of acoustic energy from ...

We derive a phenomenological theory of current-induced staggered magnetization dynamics in antiferromagnets. The theory captures the reactive and dissipative current-induced torques and the conventional effects of magnetic fields and damping. A Walker ansatz describes the dc current-induced domain-wall motion when there is no dissipation. If magnetic damping and dissipative torques are included...

Google, the largest search engine worldwide, adopts PageRank technology to determine the rank of website listings. This paper describes how damping factor is a critical factor in changing a website’s ranking in traditional Google PageRank technology. A modified algorithm based on input–output ratio concept is proposed to substitute for the damping factor. Besides there is no need to choose an o...

Air-film damping, which dominates over other losses, plays a significant role in the dynamic response of many micro-fabricated devices with a movable mass suspended by various bearing mechanisms. Modeling the damping characteristics accurately will be greatly helpful to the bearing design, control, and test in various micromotor devices. This paper presents the simulated and experimental squeez...

this paper is concerned with the surface and small scale effects on transverse vibration of a viscoelastic single-layered graphene sheet (slgs) subjected to an in-plane magnetic field. the slgs is surrounded by an elastic medium which is simulated as visco-pasternak foundation. in order to investigate the small scale effects, the nonlocal elasticity theory is employed due to its simplicity and ...