In this paper, an ideal cylindrical metamaterial invisibility cloak with infinite-length which its electric permittivity and magnetic permeability mapped to the Drude dispersion model is simulated. The sinusoidal plane waves with microwave frequencies used as sources. To this end, the dispersive finite-difference time-domain method (FDTD) used with Convolutional Perfectly Matched Layered (CPML)...

Refraction of black and gray solitons at boundaries separating different defocusing Kerr media is analyzed within a Helmholtz framework. A universal nonlinear Snell’s law is derived that describes gray soliton refraction, in addition to capturing the behavior of bright and black Kerr solitons at interfaces. Key regimes, defined by beam and interface characteristics, are identified and predictio...

ABSRACT A comparative study of the surface microstructural changes after fatigue in an ultrafine grained and coarse grained aluminum alloy was performed using orientation imaging microscopy (OIM). The fraction of low angle boundaries with misorientation less than 2.5 ̊ increased for both the coarse and ultrafine grained alloys. A consistent decrease in the fraction of low angle boundaries, with ...

A study has been perfomed on the superconducting critical current density Jc flowing across low angle grain boundaries in epitaxial thin films of YBa2Cu3O7−δ (YBCO). The materials studied were dual grain boundary rings deposited on SrTiO3 and containing 2 , 3, 5 and 7 tilt boundaries. The current density in self-field was determined by magnetometric methods at temperatures from 5 K to Tc. We co...

The recent results of the application of diffraction techniques to study the atomic structure of grain boundaries are reviewed. The outcome of the first determination of a grain boundary structure using diffraction information alone is examined. The influence of a particular metal on the grain boundary structure is examined. The variation of grain boundary structural width with parameters such ...

We present a novel algorithm for tetrahedral image-to-mesh conversion which allows for guaranteed bounds on the smallest dihedral angle and on the distance between the boundaries of the mesh and the boundaries of the tissues. The algorithm produces a small number of mesh elements that comply with these bounds. We also describe and evaluate our implementation of the proposed algorithm that is co...

Using the Molecular Dynamics technique the energy E vs the misorientation 9 has been calculated for the CSL [OOl] twist grain boundaries in Cu. Two potentials have been used; the Morse potential and a spline potential constructed by Englert and Tompa for Cu. In each case the low and high angle grain boundary regions have been clearly distinguished by using the relation E= Eo9(A-he), valid for l...

Contrary to previous simulation results on the existence of amorphous intergranular films at high-angle twist grain boundaries (GBs) in elemental solids such as silicon, recent experimental results imply structural order in some high-angle boundaries. With a novel protocol for simulating twist GBs, which allows the number of atoms at the boundary to vary, we have found new low-energy ordered st...

Measurements of the grain boundary population as a function of misorientation and boundary plane orientation show that the distribution is inversely correlated to the sum of the energies of the surfaces comprising each boundary. The observed correlation suggests that the difference between the energy of a high-angle grain boundary and the two component surfaces is relatively constant as a funct...