─ Although many numerical methods have been developed to calculate photonic bandgap structure properties, but always improvement in numerical methods is necessary to have more efficient, accurate and flexible techniques. In the present work, novel periodic meshless shape functions including so-called direct and radial shape functions are presented. The meshless approaches, based on these period...

Two multicomponent crystalline phases of (S)-ibuprofen and l-proline with 1:1 stoichiometry are reported, specifically a nonsolvate phase (Ibu-Pro) quarter-hydrate (Ibu-Pro-QH). Ibu-Pro was prepared only by solid-state mechanochemical synthesis, while Ibu-Pro-QH obtained both solution-state crystallization mechanochemistry. The crystal structures were determined directly from powder X-ray diffr...

in this research a new approach is proposed for elasto-plastic analysis of structures with truss elements. this method covers both perfectly plastic and hardening properties. the proposed technique uses substituting virtual loads instead of modifying the stiffness matrix. to solve this kind of problems, complementary programming is utilized. numerical examples demonstrate that elastoplastic ana...

A band diagram is the fundamental for investigation of the electromagnetic properties of periodic structures such as photonic crystals in optics or electromagnetic band gap structures in antenna engineering. In this paper, the two famous computational methods, finite difference frequency domain (FDFD) and finite difference time domain (FDTD) methods are applied for band diagram calculation of 2...

We fabricated sub-wavelength periodic structures by thermal nano-imprinting using our original functionally modified inorganic–organic hybrid materials. The fabricated structures exhibited excellent uniformity and surface smoothness over a large imprinted area. In addition, optical transmittance is more than 90% within visible wavelength regions after heat treatment for 2 h at 300 C. These nano...

Abstract. The introduced notion of locally periodic two-scale convergence allows one to average a wider range of microstructures, compared to the periodic one. The compactness theorem for locally periodic two-scale convergence and the characterization of the limit for a sequence bounded in H1(Ω) are proven. The underlying analysis comprises the approximation of functions, with the periodicity w...

We consider the problems of existence and structure of gaps (pseudogaps) in the spectra associated with Maxwell equations and equations that governs the propagation of acoustic waves in periodic two component media. The dielectric constant " is assumed to be real and positive, and the value of " = "b on the background is supposed to be essentially larger than the value of " = "a on the embedded...

We study the effect of coherency saturation in spatially or temporally periodical structures with randomization, applicable to a very broad class of systems. We derive a simple analytical formula in the case of uncorrelated deviations of periods with Gaussian probability distribution. Using Monte Carlo simulations, we also demonstrate that many other distributions show statistical properties th...