Search results for "solu"
showing 10 items of 7577 documents
Global dynamical behaviors in a physical shallow water system
2016
International audience; The theory of bifurcations of dynamical systems is used to investigate the behavior of travelling wave solutions in an entire family of shallow water wave equations. This family is obtained by a perturbative asymptotic expansion for unidirectional shallow water waves. According to the parameters of the system, this family can lead to different sets of known equations such as Camassa-Holm, Korteweg-de Vries, Degasperis and Procesi and several other dispersive equations of the third order. Looking for possible travelling wave solutions, we show that different phase orbits in some regions of parametric planes are similar to those obtained with the model of the pressure …
Spectral approach to D-bar problems
2017
We present the first numerical approach to D-bar problems having spectral convergence for real analytic, rapidly decreasing potentials. The proposed method starts from a formulation of the problem in terms of an integral equation that is numerically solved with Fourier techniques. The singular integrand is regularized analytically. The resulting integral equation is approximated via a discrete system that is solved with Krylov methods. As an example, the D-bar problem for the Davey-Stewartson II equations is considered. The result is used to test direct numerical solutions of the PDE.© 2017 Wiley Periodicals, Inc.
Constrained differential inclusions with nonlocal initial conditions
2017
International audience; We show existence for the perturbed sweeping process with nonlocal initial conditions under very general hypotheses. Periodic, anti-periodic, mean value and multipoints conditions are included in this study. We give abstract results for differential inclusions with nonlocal initial conditions through bounding functions and tangential conditions. Some applications to differential complementarity systems and to vector hysteresis are given.
Modélisation, Analyse et Traitement de l'Information
2016
Mes activités de recherche s’articulent, d’une part, autour de l’instrumentation et du génie biomédical,et, d’autre part, autour du traitement et de la transmission non linéaire de l’information. Elles sebasent sur la modélisation des signaux à partir de modèles non linéaires (principalement modèles deréaction-diffusion. . . ) continus (EDP) et discrets (numériques). Dans cette partie, d’un point de vuefondamental, des phénomènes dynamiques complexes ou chaotiques sont caractérisés à travers l’analyse,la classification, la reconnaissance des motifs dans des signaux physiologiques ou issus des circuitsélectroniques. Un autre axe sur lequel je travaille concerne l’analyse et le traitement des…
On the high resolution spectroscopy and intramolecular potential function of SO2
2009
Abstract Two weak stretching bands, ν 1 + 3 ν 3 and 3 ν 1 + ν 3 , of the sulfur dioxide molecule have been recorded at high resolution and analyzed for the first time with using a Fourier transform Bruker IFS-120 HR interferometer. About 1000 transitions with J max . = 51, K a max . = 16 , and 900 transitions with J max . = 53, K a max . = 16 have been assigned to the bands ν 1 + 3 ν 3 and 3 ν 1 + ν 3 , respectively. Analysis of the recorded spectra was made using the model of isolated vibrational states. Parameters obtained from the fit reproduce the initial experimental ro-vibrational energies with the rms deviation of 0.0006 and 0.0012 cm −1 for the bands, 3 ν 1 + ν 3 and ν 1 …
High resolution study of the six lowest doubly excited vibrational states of PH2D
2005
Abstract The five lowest doubly excited deformational vibrational bands ν 4 + ν 6 , 2 ν 6 , ν 3 + ν 4 , ν 3 + ν 6 , and 2 ν 3 of PH 2 D have been recorded for the first time using a Bruker 120 HR interferometer with a resolution 0.0033 cm −1 and analysed. Some transitions belonging to a very weak band 2 ν 4 have been also assigned. From the fit 24 and 86, respectively, diagonal and resonance interaction parameters were obtained which reproduce 1089 upper energy levels obtained from more than 4600 assigned transitions with the rms deviation of 0.00059 cm −1 .
Analysis of highly excited 'hot' bands in the SO2 molecule: ν2 + 3ν3 - ν2 and 2ν1 + ν2 + ν3 - ν2
2010
International audience; We set up a variational procedure of assignments of transitions and we applied it to the analysis very weak 'hot' bands, v(2) + 3v(3) - v(2) and 2v(1) + v(2) + v(3) - v(2), of the SO2 molecule. As the first step of the study, the 'cold' bands, 3v(3) and 2v(1) + v(3), are re-analysed and transitions belonging to those bands are assigned up to the values of quantum numbers J(max.) = 60, K-a(max.) = 19, and J(max.) = 69, K-a(max.) = 20 for the bands 3v(3) and 2v(1) + v(3), respectively. After 'cleaning' the experimental spectrum from transitions belonging to the 3v(3) and 2v(1) + v(3) bands, a variational procedure was used that allowed us to assign 230 and 115 transiti…
Portlandite solubility and Ca 2+ activity in presence of gluconate and hexitols
2021
The current paper investigates the impact of gluconate, D-sorbitol, D-mannitol and D-galactitol on calcium speciation at high pH values by i) solubility measurements of portlandite (Ca(OH)2) and ii) potentiometric titration measurements of calcium salt solutions. Thermodynamic modeling was used to fit the chemical activities of Ca2+ and OH- ions and thus to determine the strength and kind of the different Ca-organic-hydroxide complexes. The strength of complex formation with Ca decreases in the order gluconate >> sorbitol > mannitol > galactitol, which follows the same order as sorption on portlandite. Heteropolynuclear gluconate complexes with calcium and hydroxide dominate the…
High-resolution far-infrared synchrotron FTIR spectroscopy and analysis of the ν 7 , ν 19 and ν 20 bands of trioxane
2022
Rovibrational bands spectra of three ν20, ν7 and ν19 bands of 1, 3, 5 – trioxane (H2CO)3 were recorded in the 50–650 cm−1 range using a long path absorption cell coupled to a high resolution Fourier transform spectrometer and synchrotron radiation at the AILES beamline of the SOLEIL synchrotron. More than 16 000 lines were assigned with a dRMS better than 0.17 × 10−3 cm−1. Two different formalisms (tensorial and Watson) were used to derive accurate rotational and quartic parameters for the three bands and for the first time, a precise determination of Coriolis parameter and q+ l−doubling constant for both ν20 and ν19 perpendicular bands was obtained. Last, each set of spectroscopic paramete…
Use of fractal geometry to dissolution study of a sweetener excipient
2002
International audience