We present a novel waveguide geometry for enhancing and confining light in a nanometer-wide low-index material. Light enhancement and confinement is caused by large discontinuity of the electric field at high-index-contrast interfaces. We show that by use of such a structure the field can be confined in a 50-nm-wide low-index region with a normalized intensity of 20 microm(-2). This intensity i...

The study of the mechanical interaction among the host, interface, and a device embedded within a laminated composite is important. Embedding micro-sensors in composite laminates produces material discontinuity around the inclusions. This in turn produces stress concentrations at or near the inclusions. Both 2D plane strain and 3D FEM models are developed to analyze the stress/strain state surr...

The band structure of 2D photonic crystals and their eigenmodes can be efficiently computed with the finite element method (FEM). For second order elliptic boundary value problems with piecewise analytic coefficients it is known that the solution converges extremly fast, i.e. exponentially, when using p-FEM for smooth and hp-FEM for polygonal interfaces and boundaries. In this article we discre...

Based on low-temperature experimental data in solid dielectric crystals, we derive a model of heat conduction for rigid materials using the theory of thermodynamic internal state variables. The model is intended to admit wavelike propagation of heat below—and diffusive conduction above—a particular temperature value A rapid decay of the speed of thermal waves occurs just below this temperature,...

Based on low temperature experimental data in solid dielectric crystals, we derive a model of heat conduction for rigid materials using the theory of thermodynamic internal state variables. The model is intended to admit wavelike propagation of heat below and diffusive conduction above a particular temperature value θλ. A rapid decay of the speed of thermal waves occurs just below this temperat...

The effect of the discontinuity of the rail ends and the presence of lower modulus insulation material at the gap to the variations of stresses in the insulated rail joint (IRJ) is presented. A three-dimensional wheel – rail contact model in the finite element framework is used for the analysis. It is shown that the maximum stress occurs in the subsurface of the railhead when the wheel contact ...

a considerable amount of energy is released in the form of shock wave from explosive charge detonation. shock wave energy is responsible for the creation of crushing and fracture zone around the blast hole. the rest of the shock wave energy is transferred to rock mass as ground vibration. ground vibration is conveyed to the adjacent structures by body and surface waves. geological structures li...