[en] Molecular dynamics (MD) simulations on lanthanide(III) and alkaline-earth(II) complexes with poly-amino-carboxylates (ethylene-diamino-tetra-acetate EDTA^4-, ethylene-diamino-tri-acetate-acetic acid EDTA(H)^3-, tetra-aza-cyclo-dodecane-tetra-acetate DOTA^4-, methylene-imidine-acetate MIDA^2-) are reported. First, a consistent set of Lennard-Jones parameters for La³⁺, Eu³⁺ and Lu³⁺ cations has been derived from free energy calculations in aqueous solution. Observed differences in hydration free energies, coordination distances and hydration numbers are reproduced. Then, the solution structures of 1:1 complexes of alkaline-earth and/or lanthanide cations with EDTA^4-, EDTA(H)^3-, DOTA^4- and 1:2 complexes of lanthanide cations with MIDA^2- were studied by MD in water. In addition, free energy calculations were performed to study, for each ligand, the relative thermodynamic stabilities of complexes with Ca²⁺ vs Sr²⁺ and vs Ba²⁺ on the one hand, and with La³⁺ vs Eu³⁺ and vs Lu³⁺ on the other hand. Model does not take into account explicitly polarization and charge transfer. However, the results qualitatively agree with experimental complexation data (structure and selectivities). (author)

[en] Design by analysis has been particularly pointed out by the european pressure equipment directive. Advanced mechanical analysis like finite element method are used instead of classical design by formulas or graphs. Structural behaviour can be understood by the designer. Design by analysis of metallic pressure equipments is widely used. Material behaviour or limits analysis is based on sophisticated approach (elasto-plastic analysis,..). Design by analysis of composite pressure equipments is not systematically used for industrial products. The difficulty comes from the number of information to handle. The laws of mechanics are the same for composite materials than for steel. The authors want to show that in design by analysis, the composite material approach is only more complete than the metallic approach. Mechanics is more general but not more complicated. A multi-material approach is a natural evolution of design by analysis of composite equipments. The presentation is illustrated by several industrial cases - composite vessel: analogy with metallic calculations; - composite pipes and fittings; - welding and bounding of thermoplastic equipments. (authors)

[en] The para-super Virasoro and fractional super Virasoro algebras are two known generalizations of the ordinary centerless super Virasoro algebra. We present here a generalized algebraic structure which allows the unification of these two generalizations within the framework of a fractional superspace. New kinds of algebras are also described. (Author) 15 refs

[en] This paper presents a fractional superspace formulation of the centerless parasuper-Virasoro and fractional super-Virasoro algebras. These are two different generalizations of the ordinary super-Virasoro algebra generated by the infinitesimal diffeomorphisms of the superline. The authors work on the fractional superline parametrized by t and θ, with t a real coordinate and θ a paragrassmann variable of order M and canonical dimension 1/F. We further describe a more general structure labeled by M and F with M ≥ F. The case F = 2 corresponds to the parasuper-Virasoro algebra of order M, while the case F = M leads to the fractional super-Virasoro algebra of order F. The ordinary super-Virasoro algebra is recovered at F = M = 2. The connection with q-oscillator algebras is discussed

[en] Thin films of pure or mixed II-VI compounds can be obtained from the elements by reactive cathode sputtering. It is also possible to dope them directly during the synthesis by introducing the doping elements in the plasma, without further thermal treatment, and so to obtain luminescent thin films. This technique was used for preparing copper and chlorine activated zinc sulfide thin films. They exhibit non-usual luminescent spectra. Emission spectra show that various types of luminescent centers are simultaneously present, especially the well known green center, but also a yellow-orange center which is easily obtained by reactive cathodic sputtering. Varying the quantity of doping elements added to the plasma allows the change continuously the relative density of these centers and consequently the spectral repartition of the luminescence from green to orange

[en] An introduction to parasupersymmetric quantum mechanics and parasuperalgebras is given. The work of Rubakov and Spiridonov is described. The second order parasuperconformal algebra which generalizes the OSp (2,1) superalgebra is introduced. An explicit realization is given in terms of the symmetry generators of a quantum mechanical example. The relevant unitary representations are constructed, allowing and algebraic determination of the energy spectrum and wave functions. (author)

[en] It is shown how symmetries of Dirac equations can be used to obtain constants of motion for nonrelativistic supersymmetric quantum Hamiltonians. In particular, conserved supercharges are found for a spin-1/2 particle in the field of a dyon which yield under anticommutation the generalized Runge-Lenz symmetry of the system. (orig.)

[en] This paper reports on supersymmetric field theories that have the distinctive feature of being invariant under transformations that mix bosonic and fermionic variables. Reduction to 0 + 1 dimensions yields mechanical models with an analogous invariance. In this case, the Grassmannian variables are interpreted as describing (classically) the spin degrees of freedom of the particles involved. After canonical quantization, the corresponding quantities obey the standard anticommutation relations of fermionic creation and annihilation operators. It is known that paraquantitization offers alternative to the usual quantization scheme. In this framework, one can expect that it is possible to construct parasupersymmetric theories, that is, theories which are invariant under transformations between bosonic and parafermionic variables. As a matter of fact, Rubakov and Spiridonov has recently shown how the parasupersymmetric generalization of supersymmetric Quantum Mechanics proceeds. In this case, the fermionic creation and annihilation operators obey paracommutation relations. The applications of supersymmetric Quantum Mechanics are many. One might hope that its parasupersymmetric generalization will be as useful. The elaboration of parasupersymmeric Quantum Mechanics moreover has led to new mathematical constructs; indeed, the symmetry generators realize algebras involving products of degree higher than 2

No abstract available

[en] This document provides the procedures for determining the performance of stand-alone PV systems. The procedures in this document provide a common approach for evaluating whether a given PV system is suitable to perform the function for which it was designed and manufactured to accomplish, and whether it will provide adequate power to run the load. These procedures cover small stand-alone PV systems. They cover complete outdoor system testing. Test results are valid only for the system that is tested