Tandem mass spectrometric analysis of a mixture of isobars using the survival yield technique.

International audienceCollision induced dissociation tandem mass spectrometry experiments were performed to unequivocally separate compounds from an isobaric mixture of two products. The Survival Yield curve was obtained and is shown to consist in a linear combination of the curves corresponding to the two components separately. For such a mixture, a plateau appears on the diagram in lieu of the continuous decrease expected allowing for the structural study of the two components separately. The width of the plateau critically relates to the fragmentation parameters of the two molecular ions, which need to be sufficiently different structurally for the plateau to be observed. However, at constant fragmentation parameters, we have observed the width significantly increases at large m/z. This makes the separation more and more efficient as isobars have larger m/z and the technique complementary to those applicable at low m/z only. We have observed that the vertical position of the plateau relates linearly to the relative concentration of the two compounds that may be useful for quantification. Repeatability was estimated at 2% on a quadrupole ion trap. An advantage of using survival yield curves only, is that a priori knowledge of the respective fragmentation patterns of the two isobars becomes unnecessary. Consequently, similar performances are obtained if fragments are isobaric, which is also demonstrated in our study. The critical case of reverse peptides, at low m/z and similar fragmentation parameters, is also presented as a limitation of the method

French Roadmap for complex Systems 2008-2009

This second issue of the French Complex Systems Roadmap is the outcome of the Entretiens de Cargese 2008, an interdisciplinary brainstorming session organized over one week in 2008, jointly by RNSC, ISC-PIF and IXXI. It capitalizes on the first roadmap and gathers contributions of more than 70 scientists from major French institutions. The aim of this roadmap is to foster the coordination of the complex systems community on focused topics and questions, as well as to present contributions and challenges in the complex systems sciences and complexity science to the public, political and industrial spheres

Kinetic roughening phase transition in surface growth: Numerical study and mean-field approach

International audienceNumerical simulations are reported on a ballistic deposition model that interpolates between the weak- and strong-coupling limits of the stochastic Burgers equation introduced by M. Kardar, G. Parisi, and Y. C. Zhang [Phys. Rev. Lett. 56, 889 (1986)]. The model, which is built on a d-dimensional cubic lattice, considers a random deposition of two kinds of particles, with concentrations c and 1-c, that stick to the deposit or may slide on it by no more than one lattice spacing. Evidence is given for the existence of a phase transition, when varying c, in d=3 and 4, but not in d=2, in agreement with an analytical prediction due to Halpin-Healy [Phys. Rev. Lett. 62, 442 (1989)]. The transition is investigated by analyzing, as a function of c, the scaling exponents of the surface thickness as well as the compactness of the bulk of the deposit. An analytical mean-field approach is proposed that describes most of the features of the phase transition

Ballistic Deposition of Clusters

International audienceRandom ballistic deposition of clusters is studied by means of a simple model built on a two-dimensional square lattice in which initially the sites are randomly occupied with concentration c to form connected clusters. Then these clusters are allowed to fall along vertical trajectories until they stick to the cluster in contact with the basal horizontal line. The concentration of the deposit, cd, and the scaling behavior of the width of its surface, σ, are studied as a function of c and of the geometrical characteristics. The change of the scaling behavior is analyzed when c approaches the percolation concentration

Restricted step height ballistic deposition with sticky and non-sticky particles

ISBN : 1560720980International audienc

Effets de l'isomérie sur les potentiels d’ionisation : spectres des photoélectrons de dihalogéno-benzènes

Les spectres pliotoélectroniques des 12 dérivés benzéniques disubstitués ci-après ont été enregistrés : bromofluorobenzènes (o, m, p); chlorofluorobenzènes (o, m, p) ; bromotrifluoro-méthylbenzènes (o, m, p) ; chlorotrifluorométhylbenzènes (o, m, p). Les potentiels d’ionisation correspondant aux niveaux π2 et π3 du noyau benzénique, npx et npy des halogènes sont mesurés. Un traitement qualitatif faisant intervenir les déplacements électroniques inductifs et mésomères permet d’interpréter les variations de ces potentiels d’ionisation selon la position et la nature des substituants. En particulier, le comportement différent des substituants F et CF3, est mis en évidence

L'évaluation environnementale des infrastructures routières par la méthode des modules routiers

ISSN 1290-256XUne méthode d'évaluation environnementale de tronçons routiers, modulaire, basé sur l'analyse de cycle de vie (ACV) et développée au Laboratoire central des Ponts et chaussées (LCPC) appelée méthode des modules routiers est présentée dans cet article. Après avoir été élaborée en interurbain pour des matériaux classique, elle a été étendue à des matériaux alternatifs et à l'urbain. Fondée sur les principes de l'ACV, cette méthodes comporte notamment des calculs de flux d'inventaires de cycle de vie (ICV), de coûts externes de la pollution et des calculs d'impacts environnementaux. Les principes et fonctionnalités des outils dédiés aux chaussées sont présentés

A synthetic structural map of Tertiary formations in the Paris Basin

International audienceSedimentary basins are subject to tectonic stresses that propagate from continental plate boundaries. The resulting strain can vary: the lithosphere can buckle and fold, brittle deformation can occur, often reactivating basement faults, and microstructure networks of faults, joints and veins can develop on a local scale. These intraplate deformations, either attributed to the Pyrenean Orogeny or to the Alpine Orogeny, are present in Tertiaryformations of the Paris Basin. Tectonic structures directly affect the stratigraphic architecture and facies of sedimentary deposits. However, when compared with the well-documented architecture of sedimentary deposits and tectonic structures of the Paris Basin, relatively little is known about the relationship between the two. Preliminary results of this PhD revisit the tectonic structures of Tertiary formations using new and existing data.Since 2000, the BRGM reprocessed thousands of kilometers of industrial seismic lines covering the entire Paris Basin. We propose an interpretation of the base of Tertiary formations in the Paris Basin, calibrated by hundreds of wells with velocity surveys. Strategically placed geological cross sections made with well data containing the top depth of different Tertiary stages, combined with information from geological maps (1/50 000 scale edited by the BRGM), reveal the Cenozoic tectonic structure of the Paris Basin.Interpreted seismic lines and geological cross sections make up the initial results of this PhD, illustrated by a synthetic structural map of Tertiary deformations in the Paris Basin. This map shows long wavelength and low amplitude post-Mesozoic undulations along with faults traversing the Tertiary base. The continuation of this PhD will involve fieldwork with structural observations (deformation directions, geometry, density, distribution) and sample collecting as well as laboratory work (magnetic and wave velocity anisotropy and in-situ U-Pb calcite dating) in order to constrainthe temporal and spatial evolution of paleo stresses propagating from tectonic plate limits

A life cycle analysis of automobile tires in France

SIGLEAvailable at INIST (FR), Document Supply Service, under shelf-number : DO 2328 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Chronique de jurisprudence, Procédure civile (mai 2012)

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