Semiclassical gravitoelectromagnetic inflation in a Lorentz gauge: Seminal inflaton fluctuations and electromagnetic fields from a 5D vacuum state

Using a semiclassical approach to Gravitoelectromagnetic Inflation (GEMI), we study the origin and evolution of seminal inflaton and electromagnetic fields in the early inflationary universe from a 5D vacuum state. The difference with other previous works is that in this one we use a Lorentz gauge. Our formalism is naturally not conformal invariant on the effective 4D de Sitter metric, which make possible the super adiabatic amplification of magnetic field modes during the early inflationary epoch of the universe on cosmological scales.     

The graal experiment: Beam polarization asymmetries in pseudoscalar meson photoproduction

The GRAAL tagged and polarized γ beam has been operating with a maximum energy of 1100 MeV. For the first time asymmetry results in ν photoproduction were obtained and will be shown. Interesting results have also been obtained for π⁰ and π⁺ photo-production, that largely confirm the already existing ones, but also extend in not yet explored angular and energetic regions, especially for backward scattering and energies greater than 900 MeV.     

Synthesis,characterization and X-ray crystal structure of an allyloxo functionalized nonsymmetric nickel coordination complex based on N2O2 chelating ferrocenyl ligand

The synthesis of the new air and thermally stable orange neutral dinuclear iron–nickel unsymmetrical Schiff base complex, [8-(2-oxo,5-allyloxo-phenyl)-4,7-diaza-3-methyl-1-ferrocenyl-1-one-octa-1,3,7-trienato]nickel(II) (2), was achieved via the Williamson coupling reaction between the 2-oxo,5-hydroxyphenyl precursor 1 and allyl chloride in the presence of base. Complex 2 was isolated in 68% yield and characterized by IR, UV–Vis, ¹H and ¹³C NMR spectroscopy, HRMS and authenticated by a single crystal X-ray diffraction analysis. The organometallic/inorganic hybrid complex 2 consists in a ferrocenyl fragment linked to a classical Werner-type complex made of an unsymmetrical quadridentate N₂O₂ Schiff base ligand with a pendant allyl ether functionality as a potential anchoring group. The Ni(II) center displays a square-planar geometry with the nitrogen and oxygen atoms occupying mutually trans positions. The structure of 2 · H₂O shows that the water crystallization molecule interacts through two distinct intermolecular hydrogen bonds with the two oxygen atoms of the tetradentate N₂O₂ acyclic chelating ligand, forming in the solid state, a distorted six-membered ring.     

Gain of regularity for the KP-I equation

In this paper we study the smoothness properties of solutions to the KP-I equation. We show that the equation's dispersive nature leads to a gain in regularity for the solution. In particular, if the initial data ? possesses certain regularity and sufficient decay as x→∞, then the solution u(t) will be smoother than ? for 0<t?T where T is the existence time of the solution.     

Solution and Asymptotic Behaviour for a Nonlocal Coupled System of Reaction-Diffusion

This paper concerns with the existence, uniqueness and asymptotic behaviour of the solutions for a nonlocal coupled system of reaction-diffusion. We prove the existence and uniqueness of weak solutions by the Faedo-Galerkin method and exponential decay of solutions by the classic energy method. We improve the results obtained by Chipot-Lovato and Menezes for coupled systems. A numerical scheme is presented. Partially supported by CMM, Universidad de Chile, and CI²MA, Universidad de Concepción.     

Skewed VNS enclosing second order algorithm for the degree constrained minimum spanning tree problem

We develop ideas to enhance the performance of the variable neighborhood search (VNS) by guiding the search in the shaking phase, and by employing the Skewed strategy. For this purpose, Second Order algorithms and Skewed functions expressing structural differences are embedded in an efficient VNS proposed in the literature for the degree constrained minimum spanning tree problem. Given an undirected graph with weights associated with its edges, the degree constrained minimum spanning tree problem consists in finding a minimum spanning tree of the given graph, subject to constraints on node degrees. Computational experiments are conducted on the largest and hardest benchmark instances found in the literature to date. We report results showing that the VNS with the proposed strategies improved the best known solutions for all the hardest benchmark instances. Moreover, these new best solutions significantly reduced the gaps with respect to tight lower bounds reported in the literature.     

Latest results from GRAAL collaboration

The GRAAL experimental set-up consists of a polarized and tagged photon beam that covers an energy range from a minimum of 600 MeV up to a maximum of 1500 MeV, of a liquid Hydrogen or Deuterium target and of the 4π Lagrange detector optimized for photon detection. It allows the study of pseudo-scalar and vector meson photoproduCtion on the nucleon in the energy range corresponding to the second and the third resonance regions. In the following, the ∑ beam asymmetries in η and π0 photoproduction on quasi-free nucleon are shown. Also single and double polarization observables in K＋A photoproduction on free proton are shown; they are important to confirm the role of new or poorly known resonances in the 1900 MeV mass region.     

Spectrofluorimetric Determination of Second Critical Micellar Concentration of SDS and SDS/Brij 30 Systems

Potentially useful stead-state fluorimetric technique was used to determine the critical micellar concentrations (CMC(1) and CMC(2)) for two micellar media, one formed by SDS and the other by SDS/Brij 30. A comparative study based on conductimetric and surfacial tension measurements suggests that the CMC(1) estimated by the fluorimetric method is lower than the value estimated by these other techniques. Equivalent values were observed for SDS micelles without Brij 30 neutral co-surfactant. The use of acridine orange as fluorescent probe permitted to determine both CMC(1) and CMC(2). Based on it an explanation on aspects of micelle formation mechanism is presented, particularly based on a spherical and a rod like structures.