Thermal entanglement witness for materials with variable local spin lengths

We show that the thermal entanglement in a spin system using only magnetic susceptibility measurements is restricted to the insulator materials. We develop a generalization of the thermal entanglement witness that allows us to get information about the system entanglement with variable local spin lengths that can be used experimentally in conductor or insulator materials. As an application, we study thermal entanglement for the half-filled Hubbard model for linear, square and cubic clusters. We note that it is the itinerancy of electrons that favors the entanglement. Our results suggest a weak dependence between entanglement and external spin freedom degrees.Comment: 4 pages, 3 figure

Analytical Multi-kinks in smooth potentials

In this work we present an approach which can be systematically used to construct nonlinear systems possessing analytical multi-kink profile configurations. In contrast with previous approaches to the problem, we are able to do it by using field potentials which are considerably smoother than the ones of Doubly Quadratic family of potentials. This is done without losing the capacity of writing exact analytical solutions. The resulting field configurations can be applied to the study of problems from condensed matter to brane world scenarios

Crystallization, data collection and data processing of maltose-binding protein (MalE) from the phytopathogen Xanthomonas axonopodis pv. citri

Maltose-binding protein is the periplasmic component of the ABC transporter responsible for the uptake of maltose/maltodextrins. The Xanthomonas axonopodis pv. citri maltose-binding protein MalE has been crystallized at 293 Kusing the hanging-drop vapour-diffusion method. The crystal belonged to the primitive hexagonal space group P6_122, with unit-cell parameters a = 123.59, b = 123.59, c = 304.20 Å, and contained two molecules in the asymetric unit. It diffracted to 2.24 Å resolution

Efeito do ácido indolbutírico no enraizamento adventício em estacas de cupuaçuzeiro

A estaquia é um dos processos mais importantes de propagação vegetativa, sendo que sua aplicação na multiplicação vegetativa de fruteiras tropicais, tal como o cupuaçuzeiro (Theobroma grandiflorum), constitui uma ferramenta importante na redução de custos da produção de mudas e possibilitar a rápida multiplicação de material elite. Neste sentido, considerando a escassez de informações e a necessidade do desenvolvimento desta técnica para a produção de mudas clonais de T. grandiflorum, o presente trabalho teve como objetivo avaliar o efeito do ácido indolbutírico no enraizamento adventício de estacas de cupuaçuzeiro

Dark Sector from Interacting Canonical and Non-Canonical Scalar Fields

In this work it is investigated general models with interactions between two canonical scalar fields and between one non-canonical (tachyon-type) and one canonical scalar field. The potentials and couplings to the gravity are selected through the Noether symmetry approach. These general models are employed to describe interactions between dark energy and dark matter, with the fields being constrained by the astronomical data. The cosmological solutions of some cases are compared with the observed evolution of the late Universe.Comment: 20 pages, 13 figures, correction of misprints in eqs. (4), (5), (43), (44