Aging mechanisms of two polymeric insulation materials that are used widely in nuclear power plant low-voltage cables; cross-linked polyethylene (XLPE) and ethylene propylene rubber/ethylene propylene diene terpolymer (EPR/EPDM), are reviewed. A summary of various nondestructive methods suitable for evaluation of cable insulation is given. A capacitive sensor capable of making local nondestruct...

This paper studies the effects of frequency, pre-strain and electrode types on the dielectric property of a commercially available and most widely used acrylic elastomer, VHB 4910. The acrylic VHB film is pre-stretched in biaxial directions with the help of an in-house developed biaxial stretching device. The stretched film has been sandwiched between two card board frames to prepare samples of...

Thermo-elastic damping is a significant dissipation mechanism in high quality factor microstructures. In this paper, thermo-elastic damping of the in-plane vibration of fully clamped rectangular micro-plates has been studied. The governing equation of the micro-plate motion and heat conduction equation were derived. Then, The Galerkin method has been used to solve the coupled heat-displacement ...

Early detection of avalanche breakdown in an embedded planar capacitor dielectric is addressed in this paper. These failures were observed during accelerated temperature and voltage aging of embedded planar capacitors. At the time of avalanche breakdown there was a sharp drop in the value of insulation resistance. There was no trend in the values of insulation resistance before failure, making ...

Classical molecular dynamics is applied to study the energy dissipation (the Q factor) of the cantilever-type beam oscillators of single wall and double-walled carbon nanotubes (CNTs). The study finds that the Q factor of the CNT beam oscillator varies with the temperature T following the 1/T(0.36) dependence. For single wall CNT, the Q factor drops from 2 x 10(5) at 0.05 K to 1.5 x 10(3) at 29...

This paper analyzes energy dissipation mechanisms in vacuum-operated in-phase and anti-phase actuated micromachined z-axis vibratory gyroscopes. The type of actuation is experimentally identified as the key factor to energy dissipation. For in-phase devices, dissipation through the die substrate is the dominant energy loss mechanism. This damping mechanism depends strongly on the die attachment...

We present an embedding technique for metallic systems that makes it possible to model energy dissipation into substrate phonons during surface chemical reactions from first principles. The separation of chemical and elastic contributions to the interaction potential provides a quantitative description of both electronic and phononic band structure. Application to the dissociation of O2 at Pd(1...

We perform classical molecular dynamics simulations to examine the intrinsic energy dissipation in single-layer MoS2 nanoresonators, where the point of emphasis is to compare their dissipation characteristics with those of single-layer graphene. Our key finding is that MoS2 nanoresonators exhibit significantly lower energy dissipation, and thus higher quality (Q)-factors by at least a factor of...

The relation between the shape of the force driving a turbulent flow and the upper bound on the dimensionless dissipation factor β is presented. We are interested in non-trivial (more than two wave numbers) forcing functions in a three dimensional domain periodic in all directions. A comparative analysis between results given by the optimization problem and the results of Direct Numerical Simul...

We report a conventionally batch micromachined silicon tuning fork MEMS resonator, with ultra-low energy dissipation. The dissipation time constant of 25 minutes was experimentally achieved by using a test device with natural frequency of 570 Hz and Quality factor of 2.7 million. This low level of energy dissipation was accomplished through identification and minimization of the dominating diss...