Optical Random Riemann Waves in Integrable Turbulence

We examine integrable turbulence (IT) in the framework of the defocusing cubic one-dimensional nonlinear Schr\"{o}dinger equation. This is done theoretically and experimentally, by realizing an optical fiber experiment in which the defocusing Kerr nonlinearity strongly dominates linear dispersive effects. Using a dispersive-hydrodynamic approach, we show that the development of IT can be divided into two distinct stages, the initial, pre-breaking stage being described by a system of interacting random Riemann waves. We explain the low-tailed statistics of the wave intensity in IT and show that the Riemann invariants of the asymptotic nonlinear geometric optics system represent the observable quantities that provide new insight into statistical features of the initial stage of the IT development by exhibiting stationary probability density functions

Quantifying sudden changes in dynamical systems using symbolic networks

We characterise the evolution of a dynamical system by combining two well-known complex systems' tools, namely, symbolic ordinal analysis and networks. From the ordinal representation of a time-series we construct a network in which every node weights represents the probability of an ordinal patterns (OPs) to appear in the symbolic sequence and each edges weight represents the probability of transitions between two consecutive OPs. Several network-based diagnostics are then proposed to characterize the dynamics of different systems: logistic, tent and circle maps. We show that these diagnostics are able to capture changes produced in the dynamics as a control parameter is varied. We also apply our new measures to empirical data from semiconductor lasers and show that they are able to anticipate the polarization switchings, thus providing early warning signals of abrupt transitions.Comment: 18 pages, 9 figures, to appear in New Journal of Physic

Optical random Riemann waves in integrable turbulence

We examine integrable turbulence (IT) in the framework of the defocusing cubic one-dimensional nonlinear Schrodinger equation. This is done theoretically and experimentally, by realizing an optical fiber experiment in which the defocusing Kerr nonlinearity strongly dominates linear dispersive effects. Using a dispersive-hydrodynamic approach, we show that the development of IT can be divided into two distinct stages, the initial, pre-breaking stage being described by a system of interacting random Riemann waves. We explain the low-tailed statistics of the wave intensity in IT and show that the Riemann invariants of the asymptotic nonlinear geometric optics system represent the observable quantities that provide new insight into statistical features of the initial stage of the IT development by exhibiting stationary probability density functions

ETUDE NUMERIQUE DE LA CAPACITE PORTANTE D’UNE FONDATION DIRECTE FILANTE REPOSANT SUR UN BI-COUCHE SABLE-ARGILE

Le problème d’évaluation de la capacité portante des fondations est largement étudié en tenant compte des différents paramètres géométriques et mécaniques. Les calculs sont basés sur la méthode d'équilibre limite, la méthode des lignes de glissement et la méthode d'analyse limite. Ces méthodes analytiques de calcul indiquent de très larges écarts entre les valeurs des facteurs de portance surtout pour les grandes valeurs de l'angle de frottement et l'angle d'interface. Cet article vise, d’une part, l’estimation numérique de la capacité portante qu pour une fondation directe filante sur un bi-couche sable - argile sous une charge verticale centrée, en utilisant le code PLAXIS2D et, d’autre part, la comparaison de ces résultats numériques avec les résultats des méthodes analytiques et d’en dégager les paramètres dont elle dépend dans le cas d’un bi-couche sable-argile. Les simulations numériques ont montré une grande influence du choix de la vitesse de déplacement sur les valeurs de qu, les valeurs faibles de qu peuvent être obtenues pour une vitesse très faible. L’on a constaté aussi l'effet du nombre d’éléments et du raffinage du maillage sous la fondation sur les résultats, un bon raffinage du maillage dans les zones de forte variation des contraintes sous la fondation donne des bons résultats. La nature de l’interface entre le sol et la fondation influe considérablement sur le calcul du facteur qu, les valeurs de qu calculées pour une fondation rugueuse augmentent avec l’accroissement de l’angle φ. Et que sur un bi-couche sable sur argile, la capacité portante dépend de 5 paramètre

CARACTÉRISATION DE LA SCORIE DES TERRILS DE LA GECAMINES: UTILISATION COMME GRANULAT DANS LES ENROBES ROUTIERS (Approches analytique et expérimentale)

Plusieurs types de résidus et de sous-produits industriels peuvent être utilisés comme granulats, l'usage des scories dans la construction des chaussées requiert une connaissance approfondie de ses caractéristiques. L’article donne les résultats d’une étude géotechnique de la scorie issue de la fusion réductrice des minerais cupro-cobaltifères, étude réalisée au laboratoire Géotechnique de l’EGMF LOT 9 à Kigoma Lubumbashi au Congo R.D. et au Laboratoire du Génie Civil de l’UCL en Belgique Ces résultats ont permis d’une part de catégoriser la scorie étudiée comme granulat sur base des normes P18-304, NBN EN 13043 (granulats pour mélanges hydrocarbonés), NBN EN 13242, de la classifier sur base de la norme XP P18 540 et conformément à la Directive Produits de Construction (DPC, Directive Européenne n° 89/68/CEE modifiée par la Directive 93/68/CEE) ; et d’autre part de justifier son utilisation dans les enrobés routiers

Formation of phase soliton complexes in an optically injected semiconductor laser

We show experimental and numerical results about attractive interactions between phase solitons in a strongly multimode semiconductor laser with injected signal. The formation of soliton bound states, or phase solitons with multiple chiral charge, is demonstrated and analyzed in terms of the (spatio-temporally resolved) phase dynamics of the system. Propagation velocity of phase solitons in the longitudinal cavity is studied, and a correlation is established with phase soliton size and total charge

Phytochemical investigation of the leaves of Leptoderris fasciculata

Leptoderris fasciculata (Benth.) Dunn is a woody liana that grows in the tropical zone of West Africa, where it is exploited in traditional medicine for a number of uses. In the south-eastern Ivory Coast, it is applied to stop bleeding in women after childbirth or in cases of menorrhagia. The phytochemistry of this plant has received little previous attention. We report the isolation of 40,5,6,7-tetramethoxyisoflavone and dihydrochalcone, new as natural products, together with 10 known compounds from the leaves of L. fasciculata collected in the Ivory Coast. (C) 2013 Phytochemical Society of Europe. Published by Elsevier B. V. All rights reserved

Partial trisomy 4q associated with young-onset dopa-responsive parkinsonism.

peer reviewedOBJECTIVE: To describe a patient who developed a young-onset, dopa-responsive parkinsonism linked to a de novo heterozygous interstitial duplication 4q. DESIGN: Case report. SETTING: Movement Disorder Outpatient Clinic at the University Hospital Centre, Liege, Belgium. Patient A 31-year-old woman. MAIN OUTCOME MEASURES: Clinical, neuroimaging, and genetic data. RESULTS: The duplicated region contains 150 known genes, including the alpha-synuclein (SNCA) gene locus. Motor and 6-[(18)F]fluoro-L-dopa positron emission tomography features are similar to those previously reported in heterozygote SNCA duplication carriers. Altered expression of other genes contained in the duplicated region may contribute to clinical features that are uncommon in the phenotypic spectrum of SNCA multiplications such as delayed developmental psychomotor milestones during infancy and musculoskeletal abnormalities. CONCLUSION: This case report provides new insights on the genetic basis of parkinsonism