Transition metal atoms encapsulated in adamantane molecules

We performed a first principles total energy investigation on the structural, electronic, and magnetic properties of 3d-transition metal-encapsulated adamantane molecules (TM@C(10)H(16). with TM = Cr, Mn, Fe, Co, and Ni). We find that the C-C interactions are strong enough to maintain the molecular rigidity upon TM incorporation, although outward relaxations and formation energies are large. We built a microscopic model that explains the electronic structure of those molecules. (C) 2011 Elsevier B.V. All rights reserved.

Trends on 3d transition metal impurities in diamond

We carried out a first principles investigation on the electronic properties and chemical trends of 3d transition metal related impurities in diamond. In terms of formation energy, the interstitial site is considerably more unfavorable than the substitutional or divacancy ones. Going from Ti to Ni, the 3d-related energy levels in the gap become deeper toward the valence band in all three sites. However, in the divacancy one, those levels cross with the divacancy-related ones, such that the electronic property of the center depends on the character of the highest occupied level. (C) 2009 Elsevier B.A. All rights reserved.

Imagem publicitária e semiótica aplicada

Usando como base algumas das idéias defendidas por Juremir Machado da Silva em seu livro O que Pesquisar quer dizer (2010), o presente texto se propõe a reafirmar a velha crença de que as teorias semióticas, independente de suas bases teóricas, servem às pesquisas empíricas à medida que permitem ao pesquisador compreender a estrutura interna das linguagens (questão também abordada em CARDOSO, 2010). E, através dessa idéia, apresentar a atual pesquisa do grupo O signo visual nas mídias, que cuida, nesse momento, da aplicação de diferentes teorias semióticas em um único objeto, uma peça publicitária.