Biomedical subjects

Silvia Gennari

Publications and source records attributed to Silvia Gennari.

3 recordsLinked to original sources

PubMed2006

Simulation study of wave propagation instabilities for the combustion synthesis of transition metals aluminides.

Interest in the mode of propagation of self-sustaining reactions has been motivated by the influence of the mode on the microstructure and composition of the final product. However, comprehensive studies relating the onset of the various propagation modes to the chemical and phase transformations taking place in the sample are still lacking. In the present work propagation instabilities in self-propagating high-temperature synthesis (SHS) of transition metal aluminides are studied using a computer simulation approach. The results are presented for the SHS of NiAl, CoAl, TiAl, and NbAl(3). Particular emphasis is made with respect to the influence of process variables and system parameters on the onset of propagation instabilities, in relation to the physicochemical processes taking place during the propagation of the combustion front.

Journal Article↗

PubMed2006

Incorporation of trivalent cations in synthetic garnets A3B5O12 (A = Y, Lu-La, B = Al, Fe, Ga).

Static-lattice atomistic calculations have been used to study the solution energy for the incorporation of 13 foreign cations at 3 different lattice positions of 12 synthetic garnets. Trends have been obtained as a function of the ionic radius of the dopant cation, and the predictions about site preference have been compared with both literature and experimental data. The preferred substitution site is mainly determined by the ionic size and has been correctly predicted in all cases. Moreover, the energy difference between the preferred substitution site and the next favored site is relatively small in several cases, and hence the foreign ions can be inserted at two different positions by using the correct stoichiometry. A remarkably different behavior has been encountered for Al garnets, due to the smaller size of the unit cell. In particular, some cations, such as Fe3+ and Ga3+, can be inserted at the dodecahedral position usually occupied by the rare-earth ion. Despite the limitations of the static-lattice approach, the results of the present simulations help in the understanding of the defect chemistry of garnets, which is strongly responsible for the physicochemical properties (such as luminescence and ferrimagnetism) that make garnets interesting for technological applications. Such results lead to the possibility of tuning the optical and luminescence properties of garnets by the formation of different types of solid solutions.

Journal Article↗

PubMed2003

Processing correlates of lexical semantic complexity.

This paper explores how verb meanings that differ in semantic complexity are processed and represented. In particular, we compare eventive verbs, which denote causally structured events, with stative verbs, which denote facts without causal structure. We predicted that the conceptually more complex eventive verbs should take longer to process than stative verbs. Two experiments, a lexical decision task and a self-paced reading study, confirmed this prediction. The findings suggest that (a) semantic complexity is reflected in processing time, (b) processing verb meanings involves activating properties of the event structure beyond participants' roles, and (c) more generally, lexical event structures, which subsume thematic roles, may mediate between syntactic knowledge and semantic interpretation.

Humans↗