A New Robust Algorithm to Trace Curves

We are presenting here a new reliable algorithm to trace curves using interval arithmetic. We give several computable criteria which guarantee the convergence of the correction step of the classical predictor-corrector method. Our method avoids, for instance, to jump from a component of the curve to another one; this kind of mistake typically causes inconsistencies in the topology of intersecting surfaces in geometric modelers.     

Russian and European gas interdependence: Could contractual trade channel geopolitics?

In a framework of international political economics, this article analyses the increasing distance between Russia and the European Union (EU) in their interdependent relationship with regard to gas. The representations of economic risks associated with the dominant position of the Russian seller in the European gas market are analysed in terms of industrial economics. Then the relevance of possible responses by the EU is analysed in relation to the reality of alleged risks of gas dependence: the tentative EU–Russia regulatory unification, the creation of a single gas negotiator, and the support to a denser pan-European network, with additional entry points and sources of supply and increased market integration in order to increase the contestability of the markets.     

A functional formalization of on chip communications

This paper presents a formal model and a systematic approach to the validation of communication architectures at a high level of abstraction. This model is described mathematically by a function, named GeNoC. The correctness of GeNoC is expressed as a theorem, which states that messages emitted on the architecture reach their expected destination without any modification of their content. The model identifies the key constituents common to all on chip communication architectures, and their essential properties from which the correctness theorem is deduced. Each constituent is represented by a function that has no explicit definition but is constrained to satisfy the essential properties. Thus, the validation of a particular architecture is reduced to the proof that its concrete definition satisfies the essential properties. In practice, the model has been defined in the logic of the ACL2 theorem proving system. We illustrate our approach on several architectures that constitute concrete instances of the generic GeNoC model. Some of these applications come from industrial designs, such as the AMBA AHB bus or the Octagon network from ST Microelectronics. C. Delgado Kloos     

Phase transitions in wetting films at the surface of Ga–Pb alloys

Surface phase transitions at Ga-rich liquid surfaces have been investigated in Ga–Pb alloys with low lead content. In the region of the liquid–liquid miscibility gap, the Pb-rich liquid phase completely wets the surface of the Ga-rich phase at coexistence. Observations have been made of demixing and solidification of the Pb-rich liquid film. Ga-rich alloys, which are single-phase below the monotectic temperature, can be undercooled below the liquidus, as far as the metastable binodal line where the Pb-rich wetting liquid film forms and solidifies into thin {111} Pb crystals. These films completely redissolve upon reheating to the liquidus temperature. Freezing occurs at surfaces because of complete wetting of the liquid rich in the high melting point component and the hysteretic character of the solidification transformation. Such “surface” experiments allow assessment of the stable and metastable liquidus lines of the Ga–Pb phase diagram in the vicinity of the monotectic temperature.     

Normes d’imagerie et de fréquence subjective pour 1 760 mots monosyllabiques de la langue fran?aise.

This study aimed at providing subjective frequency and imageability norms for a sample of 1,760 monosyllabic French words and thereby, increasing the pool of normative data available for research in cognitive science and language processing. The results indicate that the reliability of the estimates is high, with coefficients ranging between .93 and .99 for the frequency and imageability ratings. External validity was investigated by calculating correlations with ratings drawn from all similar studies and for which the number of shared items was sufficient. These coefficients vary between .73 and .88 for subjective frequency and between .64 and .97 for imageability. The correlation between subjective frequency and imageability in the present study was significant and relatively high (r = .64). The implications of these results for the selection of experimental stimuli for research are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Synthesis, characterization and biocidal properties of epoxy resins containing quaternary ammonium salts

Summary Quaternary ammonium salts (QAS) were covalently-bound to epoxy resins of different DP in two steps: addition of a N,N-dialkylaminoethanethiol followed by the quaternization of the tertiary amine by an alkylbromide (C₈H₁₇Br to C₁₄H₂₉Br). The products were characterized by ¹H NMR spectroscopy. The QAS-containing oligomers were used as polyols to prepare polyurethane (PU) films by reaction with a triisocyanate. The films show a good bactericidal activity against Escherichia coli, which is preserved after 6 months of immersion in water. Received: 30 December 1999/Revised version: 23 March 2000/Accepted: 23 March 2000     

VEGF-R2/Caveolin-1 Pathway of Undifferentiated ARPE-19 Retina Cells: A Potential Target as Anti-VEGF-A Therapy in Wet AMD by Resvega,an Omega-3/Polyphenol Combination

Age-related macular degeneration (AMD) is one of the main causes of deterioration in vision in adults aged 55 and older. In spite of therapies, the progression of the disease is often observed without reverse vision quality. In the present study, we explored whether, in undifferentiated ARPE-19 retinal cells, a disruption of the VEGF receptors (VEGF-R)/caveolin-1 (Cav-1)/protein kinases pathway could be a target for counteracting VEGF secretion. We highlight that Resvega^®, a combination of omega-3 fatty acids with an antioxidant, resveratrol, inhibits VEGF-A secretion in vitro by disrupting the dissociation of the VEGF-R2/Cav-1 complex into rafts and subsequently preventing MAPK activation. Moreover, DNA ChIP analysis reveals that this combination prevents the interaction between AP-1 and vegf-a and vegf-r2 gene promoters. By these pathways, Resvega could present a potential interest as nutritional complementation against AMD.     

From compressibility to structural investigation of sodium dodecyl sulphate — Part 2: A singular behavior under pressure

Investigations were carried out to elucidate the compression behavior of a powdered surfactant, sodium dodecyl sulphate (SDS), based on a comparison with the main component of a detergent formulation, i.e. the chorine provider (DCCNa). The energetic analysis based on the compression cycles highlighted a lower compressibility of SDS compared with DCCNa, especially due to its worse packing ability, larger elasticity and bad cohesion ability. Also, it pointed out that the pycnometric density seemed to be overrun under pressure whereas a residual porosity had been evidenced in the expanded tablets. DSC/DTA analysis, Raman spectroscopy as well as powder X-ray diffraction refuted the hypothesis of a physico-chemical transformation of SDS under pressure. This was in accordance with the morphology of the SDS particles, quite unchanged after compression. The pycnometric density measurements have been improved; firstly, it allowed to properly express the compaction ratio of the ejected SDS tablets, and secondly, it led to conclude to a reversible intrinsic compressibility for pressures higher than 50 MPa, explained by the predominant elastic behavior of SDS.     

Effect of cations on corrosion of zinc and carbon steel covered with chloride deposits under atmospheric conditions

The effect of sodium, calcium, and magnesium chlorides deposited on zinc and carbon steel surfaces was studied under atmospheric conditions. The cations strongly affected the corrosion rate of zinc, whereas they had a significantly lower impact on the corrosion of carbon steel. The corrosivity of cations of chloride salts for zinc increased in order of Mg²⁺ < Ca²⁺ < Na⁺. The higher corrosion resistance of zinc treated with calcium and magnesium chlorides was connected to prevention of formation of hydrozincite during zinc exposure in wet air. It was observed that zinc weight loss and the carbonate to simonkolleite ratio in corrosion products were correlating. The principal protective effect of bivalent cations can be seen in the decrease of pH of the surface electrolyte, which was caused by hydrolysis of such cations and subsequent formation of simonkolleite that blocked the cathodic sites.