Exchange-bias-like effect in Pr0.75Tb0.25Al2 and Pr0.7Tb0.3Al2 samples

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)The magnetic behavior of pseudobinary Pr0.7Tb0.3Al2 and Pr0.75Tb0.25Al2 compounds was studied, and a predominant ferrimagnetic ordering was observed. Noteworthy characteristics such as negative magnetization, compensation points and exchange-bias-like (EB-like) effect were found. This EB-like effect was observed at temperatures below the compensation points. The effect is somewhat different from the one already studied in similar systems combining light and heavy rare earths. The results indicate that the EB-like effect characteristics are related to the conduction electron magnetic polarization and an induced unidirectional anisotropy present in these compounds. (c) 2013 Elsevier B.V. All rights reserved.339610Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Mercury levels and neurotoxic potential of house dust extracts

The quality of the indoor environment is affected by a set of factors that include, among others, the presence of environmental contaminants. These contaminants are potentially toxic and can negatively affect the health of the inhabitants. Therefore, their study is fundamental, especially considering that in Western societies about 90% of the time is spent inside what has been called the “built environment”. The evaluation of the indoor environment contamination has been increasingly performed using dust. This matrix acts as a reservoir and repository of chemicals that are simultaneously protected from the degradation processes occurring naturally in the external environment. Available studies are mainly based on chemical analyzes that do not allow to evaluate the toxicity in an integrated way, making the implementation of toxicological tests an imperative. In this work, we evaluated the levels of mercury, a well-known neurotoxicant, in house dust extracts collected under the framework of the 6x60x6 case study. The cytotoxic potential of these dust extracts were also analyzed in the dopaminergic neural cell line N27. The obtained results disclose a moderate neurotoxic potential of the different dust extracts analyzed and a statistically significant correlation between cell viability and mercury concentrations (p<0.05, r=0.900)

Investigation on the magnetocaloric effect in (Gd,Pr)Al-2 solid solutions

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)A theoretical and experimental investigation on the magnetocaloric properties of the rare earth pseudobinary compounds Gd1-nPrnAl2 is presented. The calculated isothermal entropy and adiabatic temperature changes under magnetic field variations from 0 to 2 T and from 0 to 5 T are in good agreement with the experimental data. For the Pr-concentrations n = 0.25, 0.5 and 0.75 the experimental data present an inverse magnetocaloric effect which was theoretically predicted and associated with the competition between the opposite magnetizations of the Gd and Pr sublattices. The two-sublattice Hamiltonian used in the calculations takes into account the crystal field, exchange and Zeeman interactions. (C) 2010 Elsevier B.V. All rights reserved.3236794798Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq