Écart à la réciprocité et identification de fissures en thermoélasticité isotrope transitoireReciprocity gap and identification of cracks in transitory isotropic thermoelasticity

We consider a three-dimensional homogeneous isotropic elastic solid containing a family of planar cracks submitted to a time-dependent thermal loading. The displacement and surface traction fields are measured over the whole external boundary of the solid. We propose in this Note to define and exploit a reciprocity gap, based only on the mechanical quantities available on the boundary, and which enables us to derive explicit formula for the location of the plane where the cracks are lying. Boundary conditions on the cracks can be of any nature provided they ensure that the normal heat flux and surface traction vector are continuous across the crack surfaces. To cite this article: S. Andrieux, H.D. Bui, C. R. Mecanique 334 (2006).     

Quantum work relations and response theory

A universal quantum work relation is proved for isolated time-dependent Hamiltonian systems in a magnetic field as the consequence of microreversibility. This relation involves a functional of an arbitrary observable. The quantum Jarzynski equality is recovered in the case this observable vanishes. The Green-Kubo formula and the Casimir-Onsager reciprocity relations are deduced thereof in the linear response regime.     

Fluctuation theorem and Onsager reciprocity relations

The Onsager and higher-order reciprocity relations are derived from a fluctuation theorem for nonequilibrium reactions ruled by the chemical master equation. The fluctuation theorem is obtained for the generating function of the macroscopic fluxes between chemiostats maintaining the system in a nonequilibrium steady state. The macroscopic affinities associated with the fluxes are identified by graph theory. The Yamamoto-Zwanzig formulas for the reaction constants are also derived from the fluctuation theorem.     

Homogeneous redox catalysis of electrochemical reactions: Part III. Rate determining electron transfer. Kinetic characterization of follow-up chemical reactions

Electrochemical systems involving moderately fast charge transfers and very fast irreversible follow-up chemical reactions usually escape from kinetic and mechanistic characterization through the standard use of electrochemical techniques. It is shown that these difficulties can be overcome using an indirect approach which involves the homogeneous redox catalysis of the considered electrochemical reaction. A procedure for determining the rate constant of such fast follow-up reaction is presented. It is illustrated by the determination of the cleavage rate constant of the chlorobenzene anion radical in DMF which reaches a value on the order of 10⁷ s^?1.     

Analysis of plasma protein adsorption onto PEGylated nanoparticles by complementary methods: 2-DE, CE and Protein Lab-on-chip system

The biodistribution of colloidal carriers after their administration in vivo depends on the adsorption of some plasma proteins and apolipoproteins on their surface. Poly(methoxypolyethyleneglycol cyanoacrylate-co-hexadecylcyanoacrylate) (PEG-PHDCA) nanoparticles have demonstrated their capacity to cross the blood-brain barrier (BBB) by a mechanism of endocytosis. In order to clarify this mechanism at the molecular level, proteins and especially apolipoproteins adsorbed at the surface of PEG-PHDCA nanoparticles were analyzed by complementary methods such as CE and Protein Lab-on-chip in comparison with 2-D PAGE as a method of reference. Thus, the ability of those methodologies to identify and quantify human and rat plasma protein adsorption onto PEG-PHDCA nanoparticles and conventional PHDCA nanoparticles was evaluated. The lower adsorption of proteins onto PEG-PHDCA nanoparticles comparatively to PHDCA nanoparticles was evidenced by 2-D PAGE and Protein Lab-on-chip methods. CE allowed the quantification of adsorbed proteins without the requirement of a desorption procedure but failed, in this context, to analyze complex mixtures of proteins. The Protein Lab-on-chip method appeared to be very useful to follow the kinetic of protein adsorption from serum onto nanoparticles; it was complementary to 2-D PAGE which allowed the identification (with a relative quantification) of the adsorbed proteins. The overall results suggest the implication of the apolipoprotein E in the mechanism of passage of PEG-PHDCA nanoparticles through the BBB.     

Fluctuation theorem and mesoscopic chemical clocks

The fluctuation theorems for dissipation and the currents are applied to the stochastic version of the reversible Brusselator model of nonequilibrium oscillating reactions. It is verified that the symmetry of these theorems holds far from equilibrium in the regimes of noisy oscillations. Moreover, the fluctuation theorem for the currents is also verified for a truncated Brusselator model.     

On the inverse emergent plane crack problem

This paper deals with the detection of emergent plane cracks, by using boundary measurements. An identifiability result (uniqueness of the solution) is first proved. Then, we look at the stability of this solution with respect to the measurement. A weak stability result is proved, as well as a Lipshitz stability result for straight cracks, by using domain-derivative techniques. © 1998 B. G. Teubner Stuttgart—John Wiley & Sons, Ltd.