Search results for "Dispersion"
showing 10 items of 1101 documents
Quantitative optical analysis of filler dispersion degree in MWCNT-epoxy nanocomposite
2012
Recently developed methodology of quantitative analysis based on optical analysis of filler particles' area distributions is applied now to estimate the dispersion efficiency of multiwall carbon nanotubes in nanocomposite prepared by solution intercalation method. Experimental parameters of dispersing (temperature, duration and power level of ultrasonication) were optimized and the most effective experimental procedure was determined. The methodology of determination of dispersion parameter is proved by indirect method of light transmittance experiments. The nanocomposite specimens having lower dispersion parameter represented the highest transmittance over the nanocomposite specimens. 2011…
ETUDE ET RÉALISATION D'UN DETECTEUR (FILTRE) MULTISPECTRAL PAR DISPERSION NON DESTRUCTIVE SPECTRALE A TRAVERS DES FILMES A NONSTRUCTURE
2020
The development of multispectral imaging, holography and lithography techniques exploits the properties of diffracting arrays in a wide variety of photonic components. They are incorporated in laser diodes as distributed Bragg reflectors, in various integrated optical functions for wavelength division multiplexing or optical interconnections, or inscribed within the fibers themselves, leading to a wide variety of sensors for detection of chemical elements, measurement of temperatures, pressures, accelerations of acquisition and or restitution of multispectral images, etc. [Lee et al. 2007] [Pagnoux et al. 2005].Among these devices, the resonant networks arouse a great interest because they …
Highly untangled multiwalled carbon nanotube@polyhedral oligomeric silsesquioxane ionic hybrids: Synthesis, characterization and nonlinear optical pr…
2015
Abstract Highly de-bundled multiwalled carbon nanotube (MWCNT) polymer nanohybrids were obtained via ionic assembling of a novel POSS-polyimidazolium-ionic liquid (POSS = polyhedral oligomeric silsesquioxanes) with oxidized MWCNTs. The synthesis, accomplished by a simple bilayer chloroform/water metathetical reaction process, was promoted by the high surfactant properties of POSS-imidazolium-polyionic liquid, which assisted the effective de-bundling, dispersion and purification of the as prepared POSS@MWCNT polymers in organic media, via a surface coating mechanism. The presence of remarkably intense radial breathing modes (RBMs) in Raman spectra, both in solution and as solid, corroborates…
Controlling electrical percolation in multicomponent carbon nanotube dispersions
2011
Carbon nanotube reinforced polymeric composites can have favourable electrical properties, which make them useful for applications such as flat-panel displays and photovoltaic devices. However, using aqueous dispersions to fabricate composites with specific physical properties requires that the processing of the nanotube dispersion be understood and controlled while in the liquid phase. Here, using a combination of experiment and theory, we study the electrical percolation of carbon nanotubes introduced into a polymer matrix, and show that the percolation threshold can be substantially lowered by adding small quantities of a conductive polymer latex. Mixing colloidal particles of different …
Nitrogen and sulfur co-doped carbon nanodots toward bovine hemoglobin: A fluorescence quenching mechanism investigation
2018
A deep understanding of the molecular interactions of carbon nanodots with biomacromolecules is essential for wider applications of carbon nanodots both in vitro and in vivo. Herein, nitrogen and sulfur co-doped carbon dots (N,S-CDs) with a quantum yield of 16% were synthesized by a 1-step hydrothermal method. The N,S-CDs exhibited a good dispersion, with a graphite-like structure, along with the fluorescence lifetime of approximately 7.50 ns. Findings showed that the fluorescence of the N,S-CDs was effectively quenched by bovine hemoglobin as a result of the static fluorescence quenching. The mentioned quenching mechanism was investigated by the Stern-Volmer equation, temperature-dependent…
Plasmon mass scale in two dimensional classical nonequilibrium gauge theory
2018
We study the plasmon mass scale in weakly coupled strongly interacting nonabelian gauge theory in a two dimensional configuration that mimics the boost invariant initial color fields in a heavy ion collision. We numerically measure the plasmon mass scale using three different methods: a Hard Thermal Loop (HTL) expression involving the quasiparticle spectrum constructed from Coulomb gauge field correlators, an effective dispersion relation and the measurement of oscillations between electric and magnetic energies after introducing a spatially uniform perturbation to the electric field. We find that the hard thermal loop expression and the uniform electric field measurement are in rough agree…
Three dimensional reductions of four-dimensional quasilinear systems
2017
In this paper we show that integrable four dimensional linearly degenerate equations of second order possess infinitely many three dimensional hydrodynamic reductions. Furthermore, they are equipped infinitely many conservation laws and higher commuting flows. We show that the dispersionless limits of nonlocal KdV and nonlocal NLS equations (the so-called Breaking Soliton equations introduced by O.I. Bogoyavlenski) are one and two component reductions (respectively) of one of these four dimensional linearly degenerate equations.
A numerical study of the small dispersion limit of the Korteweg-de Vries equation and asymptotic solutions
2012
Abstract We study numerically the small dispersion limit for the Korteweg–de Vries (KdV) equation u t + 6 u u x + ϵ 2 u x x x = 0 for ϵ ≪ 1 and give a quantitative comparison of the numerical solution with various asymptotic formulae for small ϵ in the whole ( x , t ) -plane. The matching of the asymptotic solutions is studied numerically.
Nonlinear higher-order polariton topological insulator
2020
We address the resonant response and bistability of the exciton-polariton corner states in a higher-order nonlinear topological insulator realized with kagome arrangement of microcavity pillars. Such states are resonantly excited and exist due to the balance between pump and losses, on the one hand, and between nonlinearity and dispersion in inhomogeneous potential landscape, on the other hand, for pump energy around eigen-energies of corresponding linear localized modes. Localization of the nonlinear corner states in a higher-order topological insulator can be efficiently controlled by tuning pump energy. We link the mechanism of corner state formation with symmetry of the truncated kagome…
Scaling guidelines of a soliton-based power limiter for 2R-optical regeneration applications
2010
International audience; In this work, we report scaling rules for the design of an all-fibered soliton-based power limiter for reamplification and reshaping (2R) regeneration process. In particular, we propose general guidelines to fix the optimum fiber length and initial power of the regenerator. We quantitatively point out the optical power limiting effect of the device enabling a significant reduction of the amplitude jitter of a degraded signal. Influence of the initial level of amplitude jitter is discussed and the results are compared with a self-phase modulation-based configuration working in the normal dispersion regime. Realistic numerical simulations in the context of 160 Gbit/s s…