Interaction of Energetic Heavy Ions with Polymers

The effects of electronic excitations due to irradiation of electrons or energetic heavy ion (\u3e1 MeV/amu) irradiations on Linear polymers of general formula -(CR1R2-CR3R4)n- are reviewed and compared with previous results obtained with γ and electron irradiation. The polymer modification are discussed accounting for the nature and the position of the R1, R2, R3 and R4 substituents on the main chain. It is suggested that Linear polymers evolve according to the R can nature (R=R1, R2, R3, R4). This paper includes the physical and chemical processes of electronic excitation and the mechanisms which Lead to modification of the macromolecules. An attempt is made to relate the macromolecular structure of polymers and their structural modifications under irradiation

Glow Discharge Effects on Polytetrafluoroethylene Polymers Investigated by Secondary Electron Microscopy and X-Ray Photoelectron Spectroscopy

A glow discharge treatment of Polytetrafluoroethylene avoids charging effects and permits observation of the sample in Scanning Electron Spectroscopy; x-ray Photoelectron Spectroscopy has been used to study changes in the surface chemical composition and electronic structure of the polymer produced by this treatment

Influence of organic matter, nutrients, and cyclodextrin on microbial and chemical herbicide and degradate dissipation in subsurface sediment slurries

Pesticides leaching from soil to surface and groundwater are a global threat for drinking water safety, as no cleaning methods occur for groundwater environment. We examined whether peat, compost-peat-sand (CPS) mixture, NH4NO3, NH4NO3 with sodium citrate (Na-citrate), and the surfactant methyl-beta-cyclodextrin additions enhance atrazine, simazine, hexazinone, dichlobenil, and the degradate 2,6-dichlorobenzamide (BAM) dissipations in sediment slurries under aerobic and anaerobic conditions, with sterilized controls. The vadose zone sediment cores were drilled from a depth of 11.3-14.6m in an herbicide-contaminated groundwater area. The peat and CPS enhanced chemical atrazine and simazine dissipation, and the peat enhanced chemical hexazinone dissipation, all oxygen-independently. Dichlobenil dissipated under all conditions, while BAM dissipation was fairly slow and half-lives could not be calculated. The chemical dissipation rates could be associated with the chemical structures and properties of the herbicides, and additive compositions, not with pH. Microbial atrazine degradation was only observed in the Pseudomonas sp. ADP amended slurries, although the sediment slurries were known to contain atrazine-degrading microorganisms. The bioavailability of atrazine in the water phase seemed to be limited, which could be due to complex formation with organic and inorganic colloids. Atrazine degradation by indigenous microbes could not be stimulated by the surfactant methyl-beta-cyclodextrin, or by the additives NH4NO3 and NH4NO3 with Na-citrate, although the nitrogen additives increased microbial growth. (C) 2017 Elsevier B.V. All rights reserved.Peer reviewe

The Central Complex as a Potential Substrate for Vector Based Navigation

International audienceInsects use path integration (PI) to maintain a home vector, but can also store and recall vector-memories that take them from home to a food location, and even allow them to take novel shortcuts between food locations. The neural circuit of the Central Complex (a brain area that receives compass and optic flow information) forms a plausible substrate for these behaviors. A recent model, grounded in neurophysiological and neuroanatomical data, can account for PI during outbound exploratory routes and the control of steering to return home. Here, we show that minor, hypothetical but neurally plausible, extensions of this model can additionally explain how insects could store and recall PI vectors to follow food-ward paths, take shortcuts, search at the feeder and re-calibrate their vector-memories with experience. In addition, a simple assumption about how one of multiple vector-memories might be chosen at any point in time can produce the development and maintenance of efficient routes between multiple locations, as observed in bees. The central complex circuitry is therefore well-suited to allow for a rich vector-based navigational repertoire

New sulfonated pyrrole and pyrrole 3-carboxylic acid copolymers membranes via track-etched templates

New copolymers of polypyrrole and poly(3-carboxylic acid pyrrole) have been synthesized via diaphragmatic method using track-etched polycarbonate matrix. The carboxylic acid presence permits to introduce new functionalities such as sulfonate groups. The resulted copolymer membranes with tubules microstructure has been characterized by Scanning Electron Microscopy, X-ray Photoelectron Spectroscopy, Time-of-flight Secondary Ion mass Spectrometry and FTIR. By SEM it was observed that ion-track trajectories present characteristic of crossing. FTIR, XPS and ToF-SIMS proved the attachment of the Taurin molecule to the membrane. The thermal stability study shows that the polypyrrole copolymer membranes have an exceptional stability; decomposition was not observed up to 900°C

Ein verirrter moderner Amadis? Abenteuer und Galanterie in Schnabels 'Cavalier' - in romanischer Sicht

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Den Menschenfreund willst du verraten ?' La cantate de la passion de C. Ph. E. Bach et l'oratorio poétique de l'Aufklärung

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La traduction française de 'Woldemar', "roman philosophique et sentimental' - une médiation avortée?

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Métamorphoses de l'oratorio du XVIIe au XXIe siècle

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Olier (J. H. d') et Delmas (Bruno), La planification des infrastructures nationales de documentation, de bibliothèques et d' archives, (collection «Documentation, Bibliothèques et Archives : Études et Recherches », n° 4), 1974

Le Moël Michel. Olier (J. H. d') et Delmas (Bruno), La planification des infrastructures nationales de documentation, de bibliothèques et d' archives, (collection «Documentation, Bibliothèques et Archives : Études et Recherches », n° 4), 1974. In: La Gazette des archives, n°86, 1974. pp. 212-213