stable homogeneous dispersions of carbon nanotubes (cnts) were prepared using ethanol as dispersing agent. then, using sol-gel method, dispersion in the hydroxyapatite matrix and its effects on the microstructure were investigated. the phase composition, chemical structure and morphological and size analyses were performed using xrd, ft-ir, sem, tem/saed/edx and raman spectroscopy. the influenc...

in this study, the spatial distribution of overwintered adults of sunn pest, eurygaster integriceps puton, was investigated by using dispersion parameters and indices, mathematical distribution, and regression techniques in rainfed wheat fields by sample size of 1 m2 in 2009 and 2010. the dispersion parameters including: mean-variance test and clumping parameter () showed that the overwintered ...

A dispersion-shifted fiber (DSF) is designed to have its zero dispersion wavelength in 1.55μm wavelength range. Since the dispersion of DSF is close to zero in the C-band, conditions for dense wavelength division multiplexing (DWDM) transmission using DSF are limited due to four wave mixing (FWM). In the L-band, however, the DSF has some dispersion values, so that the DWDM transmission using DS...

In this paper we present designs of fibers having non-zero positive, non-zero negative and near-zero ultra-flattened dispersion with small dispersion slope and ultra-large effective area over a wide spectral range. The designs consist of a concentric multilayer segmented core followed by a trench assisted cladding and a thin secondary core. The central segmented core helps in maintaining desire...

Chromatic dispersion profile of dual-concentric-core photonic crystal fibers is optimized for broadband dispersion compensation of single mode fibers (SMFs) by using genetic algorithm incorporated with full-vector finite-element method. From the numerical results presented here, it is found that by increasing the distance between central core and outer ring core, larger negative dispersion coef...

Return-to-zero differential phase shift keying (RZ-DPSK) is a promising modulation format for the long-haul large capacity optical fibre transmission system, and it demonstrated a superior performance compared to the conventional intensity-modulation direct-detection (IM-DD) system experimentally (Cai et al., 2006; Inoue et al., 2004; Rasmussen et al., 2004). For the IM-DD based long-haul syste...

We explain the dispersion anomaly, the tendency of stocks with high analyst forecast dispersion to produce lower future returns, by testing the implied assumption that analysts’ bias is distributed equally when portfolios are sorted by dispersion (Johnson, 2004). We find that analysts’ bias is not symmetrically distributed across dispersion groups. High dispersion firms contain forecasts that a...

We analyze the dispersive properties of inhomogeneous nanostructures (INSs) composed of alternating layers of different materials. Analysis of the interaction between the propagating pulse and the INS provides modified dispersion characteristics. An approximate theoretical model predicting the dispersion properties of the INS is developed and compared with more accurate numeric computation resu...

We study propagation of dispersion-managed solitons in optical fibers which are modeled by the nonlinear Schrödinger equation with a periodic dispersion coefficient. When the dispersion variations are weak compared to the average dispersion, we develop perturbation series expansions and construct asymptotic solutions at the first and second orders of approximation. Due to a parametric resonance...