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Arnesano, Italy

Li J.,Northwest University, China | Raabe G.,RWTH Aachen | Yang G.-M.,Northwest University, China | Duan M.-Y.,Northwest University, China | And 2 more authors.
Journal of Physical Organic Chemistry | Year: 2011

The nitration reaction of 5,10,15,20-tetranaphthylporphyrin (TNP) was investigated in detail and the mono-, di-, and tri-nitro-TNPs were synthesized in high yield using 65% HNO3. The 1H-NMR study shows that the preferred site of nitration of the naphthyl substituted porphyrin is the carbon atom of the meso-substituents para to its bond to the porphyrin ring. The reaction leads to exquisite regioselectivity in favor of the mono, di, and tri-nitro-TNP. Quantum-chemical ab initio calculations at different levels of theory were performed in order to explain the experimentally observed reactivity. Copyright © 2010 John Wiley & Sons, Ltd. Source

Ben Amar M.,University Paris Diderot | Manyuhina O.V.,University Paris Diderot | Napoli G.,UniversitaDel Salento
European Physical Journal Plus | Year: 2011

The symmetry breaking of the actin network from radial to longitudinal symmetry has been identified as the major mechanism for keratocytes (fish cells) motility on solid substrate. For strong friction coefficient, the two-dimensional actin flow which includes the polymerisation at the edge and depolymerisation in the bulk can be modelled as a Darcy flow, the cell shape and dynamics being then modelled by standard complex analysis methods. We use the theory of active gels to describe the orientational order of the filaments which varies from the border to the bulk. We show analytically that the reorganisation of the cortex is enough to explain the motility of the cell and find the velocity as a function of the orientation order parameter in the bulk. © Società Italiana di Fisica / Springer-Verlag 2011. Source

Martina L.,UniversitaDel Salento | Martina L.,National Institute of Nuclear Physics, Italy | Pavlov M.V.,RAS Lebedev Physical Institute
Journal of Physics: Conference Series | Year: 2014

The Skyrme-Faddeev model admits exact analytical non localized solutions, which describe magnetic domain wall solutions when multivalued singularities appear or, differently, always regular periodic nonlinear waves, which may degenerate into linear spin waves or solitonic structures. Here both classes of solutions are derived and discussed and a general discusssion about the existence of integrable subsectors of the model is addressed. Source

Caricato A.P.,University of Salento | Cesaria M.,University of Salento | Leo C.,University of Salento | Mazzeo M.,University of Salento | And 9 more authors.
Journal of Physics D: Applied Physics | Year: 2015

The matrix assisted pulsed laser evaporation (MAPLE) technique is emerging as an alternative route to conventional deposition methods of organic materials (solution-phase and thermal evaporation approaches). However, the high surface roughness of the films deposited by MAPLE makes this technique not compatible with applications in electronics and photonics. In this paper we report the deposition of MAPLE-films of a green light emitting polymer, commercially named ADS125GE, with remarkable low roughness values, down to about 10 nm at the thickness conventionally used in photonic devices (∼40 nm). This issue is discussed as a function of polymer concentration, target-substrate distance and substrate rotation based on AFM topography images, roughness estimation and optical (absorption and luminescent) measurements. In addition we have fabricated an organic light emitting diode with this technique using the best deposition parameters which guarantee the lowest roughness. These results open the way to MAPLE applications in organic photonics and opto-electronics. © 2015 IOP Publishing Ltd. Source

Pisanello F.,Italian Institute of Technology | Paolis R.D.,UniversitaDel Salento | Lorenzo D.,Italian Institute of Technology | Nitti S.,Italian Institute of Technology | And 9 more authors.
Microelectronic Engineering | Year: 2013

Colloidal iron oxide nanoparticles with diameters ranging from 15 + 1 nm up to 29 + 3 nm are used as pure dielectric fillers for nanoparticles-doped nanocomposites. We show that their superparamagnetic behavior allows them to increase the real dielectric constant of polydimethylsiloxane keeping unchangedthe magnetic permittivity. Moreover, all the realized nanocomposites (concentration up to 8 wt.%) show very low dielectric and magnetic losses, suggesting that, at the investigated concentrations, the proposed material can be used as a substrate for electromagnetic circuits in the frequency range between 0.5 GHzand 2.5 GHz. © 2012 Elsevier B.V. All rights reserved. Source

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