35 research outputs found
A model for the degradation of polyimides due to oxidation
Polyimides, due to their superior mechanical behavior at high temperatures,
are used in a variety of applications that include aerospace, automobile and
electronic packaging industries, as matrices for composites, as adhesives etc.
In this paper, we extend our previous model in [S. Karra, K. R. Rajagopal,
Modeling the non-linear viscoelastic response of high temperature polyimides,
Mechanics of Materials, In press, doi:10.1016/j.mechmat.2010.09.006], to
include oxidative degradation of these high temperature polyimides. Appropriate
forms for the Helmholtz potential and the rate of dissipation are chosen to
describe the degradation. The results for a specific boundary value problem,
using our model compares well with the experimental creep data for PMR-15 resin
that is aged in air.Comment: 13 pages, 2 figures, submitted to Mechanics of Time-dependent
Material
Bond graph modelling of chemoelectrical energy transduction
Energy-based bond graph modelling of biomolecular systems is extended to include chemoelectrical transduction thus enabling integrated thermodynamically-compliant modelling of chemoelectrical systems in general and excitable membranes in particular. Our general approach is illustrated by recreating a well-known model of an excitable membrane. This model is used to investigate the energy consumed during a membrane action potential thus contributing to the current debate on the trade-off between the speed of an action potential event and energy consumption. The influx of Na+ is often taken as a proxy for energy consumption; in contrast, this paper presents an energy based model of action potentials. As the energy based approach avoids the assumptions underlying the proxy approach it can be directly used to compute energy consumption in both healthy and diseased neurons. These results are illustrated by comparing the energy consumption of healthy and degenerative retinal ganglion cells using both simulated and in vitro data
Studying the co-evolution of production and test code in open source and industrial developer test processes through repository mining
Space Charge at Nanoscale: Probing Injection and Dynamic Phenomena Under Dark/Light Configurations by Using KPFM and C-AFM
International audienc