Sobre classificação de ações Anosov de R^k em (k+2)-variedades fechadas

Abstract

In this work is presented some important results about Anosov actions of R k in (k + 2)−closed manifolds. We obtained two classification theorems (Theorems A and B) which give us, essentially, that the system is a T k−1-extension of an Anosov flow. In order to show that, we used the theory of foliations of codimension one, techniques developed by Fenley, such as study of the lift of the action in the universal cover and the construction of invariant lozenges, what is more, we used some results by Maquera and Barbot, who began the studies of Anosov Actions generalizing some classic results on the way to classificate them.

Membrane Properties of Archæal Macrocyclic Diether Phospholipids

“…The improvement of the barrier properties of the macrocyclic compound A is of course linked to the presence of the bond at the termini of the chains, which prevents them from engaging in independent motions and ensures a more closepacked assembly in the liquid crystalline state. These results are in a good agreement with those obtained in our monolayer study of lipid A, [22] with those of Menger et al [14] or those of Ladika et al [16] for nonbranched macrocyclic phosphatidylcholines, and with those obtained by us for the nonbranched macrocyclic phosphates. [19] The comparable level of water permeability observed for lipid D and for DMPC is somewhat surprising, because it was shown that the introduction of a methyl branching into alkyl chains lowers T m and DH by reducing the total number of van der Waals interactions.…”

“…We showed previously in a monolayer study that the film area of the macrocyclic lipid A was significantly smaller than that of the acyclic lipid B. [22] This implies that lipid A aggregates into a more closely packed structure, which accounts for the water permeability of membranes composed of the lipid A to be lower than that of membranes composed of acyclic lipids.…”

“…[30] In our case the liposomes of archñal lipids (macrocyclic lipid A, diphytanylphosphatidylcholine B, diphytylphosphatidylcholine C and digeranylgeranylphosphatidylcholine D) also did not show any phase transition between À 40 and 60 8C. [22] These lipids are in a liquid-crystalline state over Abstract in French: Les proprieÂteÂs biophysiques de quatre phospholipides archeÂobacteÂriens de syntheÁse (un lipide A posseÂdant une seule chaîne macrocyclique polypreÂnyle et trois lipides, B, C, D, posseÂdant deux chaînes avec zeÂro, une ou quatre double-liaisons sur une des deux chaînes) ont eÂte eÂtudieÂes par calorimeÂtrie diffeÂrentielle, microscopies eÂlectronique et optique, flux bloqueÂ/diffusion de la lumieÁre et spectroscopie de RMN du deuteÂrium aÁ leÂtat solide. Ces lipides donnent une varieÂte des structures auto-organiseÂes dans leau, notament des veÂsicules et des tubules, transformeÂes lune en lautre par simple convection thermique.…”

“…We have recently synthesized a phosphatidylcholine A bearing the natural archñal C 36 macrocyclic glycerol skeleton, [20,21] and we reported the thermal analysis and monolayer studies of this synthetic lipid in a short communication. [22] The results showed that the macrocyclic lipid A aggregates into more tightly packed structures than its acyclic congener B. We present here the physicochemical properties of bilayer systems of the macrocyclic phospholipid A, and their comparison with those of its noncyclized analogues B, C and D, bearing different numbers of double bonds.…”

Investigating radiation damage in nuclear energy materials using JANNuS multiple ion beams

“…In the last decade, many materials of interest for the nuclear industry have been investigated at the JANNuS platform. A non-exhaustive list includes: nuclear fuel and surrogates such as uranium dioxide [30][31][32][33]; neutron absorber like B4C [34,35]; structural alloys for present, advanced and future fission and fusion systems as well as model metals such as iron, Fe-Cr alloys and ferritic-martensitic steels [36][37][38][39], ODS steels [40][41][42][43][44][45], austenitic steels [46][47][48][49][50][51], tungsten and copper [52][53][54], aluminum alloys [55], zirconium [56][57][58]; Enhanced Accident Tolerant Fuel [59,60]; advanced structural ceramics for innovative nuclear systems such as carbides and nitrides [61][62][63][64][65]; glasses and oxides for waste management [66][67][68][69]; advanced coatings for Liquid Metal fast Reactors [70]; polymers for cable sheath or glove box components [71]. Selected studies are presented in the following that exemplify the prime role of in s...…”