Attempts have been made for the first time to produce a friction material with thermal sensitive modulus by the inclusion of combined plastic/rubber properties of thermoplastic elastomers (TPE) as viscoelastic polymeric materials into the formulation for the purpose of increasing the damping behavior. In order to evaluate the viscoelastic parameters such as loss factor (tan δ) and elastic m...

Hunting is a flutter associated with the synchronous speed that gives rise to the gyro drifting errors and may cause objectionable time-displacement errors in video head wheel drives and other precision scanning systems. In this paper, dynamic characteristics of permanent Magnet hysteresis motors are presented and hunting is explained. New damping techniques have been developed using optimi...

Transversal vibrations of an axially moving string under boundary damping are investigated. Mathematically, it represents a homogenous linear partial differential equation subject to nonhomogeneous boundary conditions. The string is moving with a relatively (low) constant speed, which is considered to be positive.  The string is kept fixed at the first end, while the other end is tied with the ...

In the JLC/NLC X-band linear collider, it is essential to reduce the long-range dipole wakefields in the accelerator structure to prevent beam break up (BBU) and emittance degradation. The two methods of reducing the long-range wakefields are detuning and damping. Detuning reduces the wakefields rapidly as the dipole modes de-cohere but, with a finite number of modes, the wakefield will grow ag...

Measured damping rates of stable Toroidal Alfvén Eigenmodes (TAEs) have been compared with damping rates calculated with the NOVA-K code for a number of experimental conditions on Alcator C-Mod in an attempt to validate the NOVA-K damping model. Very low amplitude ( / B B θ θ ~ 10 -7 at the wall) stable TAEs are excited in Ohmic plasmas with a pair of active MHD antennas inside C-Mod. By sweepi...

This course was taught in the summer of 2010 in the Centre International des Rencontres Mathématiques as part of a program on mathematical plasma physics related to the ITER project; it constitutes an introduction to the Landau damping phenomenon in the linearized and perturbative nonlinear regimes, following the recent work [78] by Mouhot & Villani.

We analyze the effect of damping (absorption) on critical self-focusing. We identify a threshold value δth for the damping parameter δ such that when δ > δth damping arrests blowup. When δ < δth, the solution blows up at the same asymptotic rate as the undamped nonlinear Schrödinger equation.

In this paper, optimal design of hybrid low damping base isolation and magnetorheological (MR) damper has been studied. Optimal hybrid base isolation system has been designed to minimize the maximum base drift of low damping base isolation system where for solving the optimization problem, genetic algorithm (GA) has been used. In design procedure the maximum acceleration of the structure has ...

The Gilbert damping constant present in the phenomenological Landau-Lifshitz-Gilbert equation describing the dynamics of magnetization is calculated for ferromagnetic metallic films as well as Co/nonmagnet (NM) bilayers. The calculations are done within a realistic nine-orbital tight-binding model including spin-orbit coupling. The convergence of the damping constant expressed as a sum over the...

The basic formulae for the damping of the energy and betatron oscillations are derived. The results are applied to a number of examples of different lattice designs in which radiation damping effects are important. Methods of modifying and measuring the damping rates are also discussed.