Synthesis of a Structured Material Based on Compact Spheres Coated with Zn or Mg Spinel

In this work, a synthesis method of coating with thin layers of MgAl2O4 or ZnAl2O4 over alpha-Al2O3 spheres were developed.The method consisted in the deposition of a primer of bohemite on the spheres, followed by the impregnation with a solution of Mg or Zn nitrates, and further thermal treatments in order to obtain MAl2O4 (M: Mg or Zn). This method was modified to improve the thickness and purity of the layer material. With this method, layers of uniform and adequate thickness and good adhesion were achieved. Pt catalysts prepared with these materials as supports displayed good catalytic performances in the n-butanedehydrogenation reaction, especially those obtained with purified supports.Fil: Bocanegra, Sonia Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; ArgentinaFil: Ballarini, Adriana Daniela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; ArgentinaFil: Scelza, Osvaldo Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; ArgentinaFil: de Miguel, Sergio Ruben. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; Argentin

MUCIDS: an operative C environment for acquisition and processing of polarized-light scattered from biological specimens

In this work, we describe a software package, MUCIDS, completely developed in our laboratory, for acquisition and processing of differential polarizxition light-scattering data from specimens of biophysical interest. MUCIDS is a C environment that manages the whole activity of an instrument used for measurements of Mueller matrix scattering elements. It allows one to capture, analyse, process and display data from this or from other similar light-scattering experiments. The entire system is suitable for routine measurements in a general biophysical (or microbiological) laboratory because of its easy handling and maintenance. The software was written in C lattice and will run on IBM personal computers and similar. It uses IBM/DAC and GPIB/IBM interface card

Entanglement properties and phase diagram of the two orbital Hubbard model

We study the two-orbital Hubbard model in the limit of vanishing kinetic energy. The phase diagram in the V-J plane, with V and J denoting the interorbital hybridization and exchange coupling respectively, at half filling is obtained. A singlet(dimer)-triplet transition is found for a critical value of the ratio V/J. The entropy of formation, both in the mode and in the particle pictures, presents a jump at the same critical line in conformity with the suggested relation between criticality and entanglement

High rate of extrapair paternity in a human population demonstrates diversity in human reproductive strategies.

Among nonhuman species, social monogamy is rarely accompanied by complete fidelity. Evolutionary theory predicts that the rate of extrapair paternity (EPP) should vary according to socioecological conditions. In humans, however, geneticists contend that EPP is negligible and relatively invariable. This conclusion is based on a limited set of studies, almost all of which describe European-descent groups. Using a novel, double-blind method designed in collaboration with a community of Himba pastoralists, we find that the rate of EPP in this population is 48%, with 70% of couples having at least one EPP child. Both men and women were very accurate at detecting cases of EPP. These data suggest that the range of variation in EPP across human populations is substantially greater than previously thought. We further show that a high rate of EPP can be accompanied by high paternity confidence, which highlights the importance of disaggregating EPP from the notion of "cuckoldry.

A note on the analogy between superfluids and cosmology

A new analogy between superfluid systems and cosmology is here presented, which relies strongly on the following ingredient: the back-reaction of the vacuum to the quanta of sound waves. We show how the presence of thermal phonons, the excitations above the quantum vacuum for $T> 0$, enable us to deduce an hydrodynamical equation formally similar to the one obtained for a perfect fluid in a Universe obeying the Friedmann-Robertson-Walker metric.Comment: Accepted for publication in Modern Physics Letters