TECNOLOGIE FOTOVOLTAICHE PER LO SVILUPPO SOSTENIBILE. Analisi del ciclo di vita, convenienza energetica, diffusione delle utilizzazioni, futuri scenari

Viene descritto il ciclo di vita di un’installazione fotovoltaica tipo con moduli a celle in silicio cristallino a contatti stampati. La trattazione è condotta tenendo conto della metodologia LCA (alla quale sono dedicati due paragrafi di approfondimento) ed è divisa in due parti: la prima è dedicata ai processi prettamente industriali, divisi in dieci fasi consecutive, dall’estrazione delle materie prime al riciclaggio, ed è corredata di opportuni bilanci; la seconda riguarda tematiche connesse. Vengono descritte le più importanti tecnologie FV sviluppate, ad ognuna delle quali è dedicato un paragrafo. Segue uno sguardo alle diffusione e agli impieghi del fotovoltaico, con un accenno alla sua potenzialità e possibili sviluppi. Per completezza sono inclusi una breve storia delle tecnologie FV e la descrizione dell’effetto fotovoltaico

The foreclosure of the drive queer theories, gender, sex, and the politics of recognition

Siguiendo a Leo Bersani y a Lee Edelman, se podría sostener que, insistiendo en la búsqueda de reconocimiento social por parte de las minorías sexuales, la teoría de la performatividad de género de Judith Butler corre el riesgo de desexualizar la sexualidad. Por otro lado, las así llamadas teorías queer antisociales, en particular las de Edelman, podrían ser consideradas como responsables de despolitizar la política queer, privando a su sujeto de la capacidad de actuar políticamente. El propósito de este artículo es mediar entre estas dos posiciones de la teoría queer sobre el plano de una teoría del sujeto, utilizando la interpretación que Teresa de Lauertis provee acerca del concepto de pulsión.Following Leo Bersani and Lee Edelman, one might say that, by insisting on sexual minorities’ quest for social recognition, Judith Butler’s theory of gender performativity runs the risk of desexualizing sexuality. On the other hand, so-called antisocial queer theory, and Edelman in particular, could be held responsible for depoliticizing queer politics, by depriving its subject of political agency. Aim of this article is to mediate between these two positions in queer theory on the level of a theory of the subject, by means of Teresa de Lauretis’ understanding of the concept of the drive

Short-Time Elasticity of Polymer Melts: Tobolsky Conjecture and Heterogeneous Local Stiffness

An extended Molecular-Dynamics study of the short-time "glassy" elasticity exhibited by a polymer melt of linear fully-flexible chains above the glass transition is presented. The focus is on the infinite-frequency shear modulus $G_\infty$ manifested in the picosecond time scale and the relaxed plateau $G_p$ reached at later times and terminated by the structural relaxation. The local stiffness of the interactions with the first neighbours of each monomer exhibits marked distribution with average value given by $G_\infty$. In particular, the neighbourhood of the end monomers of each chain are softer than the inner monomers, so that $G_\infty$ increases with the chain length. $G_p$ is not affected by the chain length and is largely set by the non-bonding interactions, thus confirming for polymer melts the conjecture formulated by Tobolsky for glassy polymers.Comment: 18 pages, 6 figure

Cage rattling does not correlate with the local geometry in molecular liquids

Molecular-dynamics simulations of a liquid of short linear molecules have been performed to investigate the correlation between the particle dynamics in the cage of the neighbors and the local geometry. The latter is characterized in terms of the size and the asphericity of the Voronoi polyhedra. The correlation is found to be poor. In particular, in spite of the different Voronoi volume around the end and the inner monomers of a molecule, all the monomers exhibit coinciding displacement distribution when they are caged (as well as at longer times during the structural relaxation). It is concluded that the fast dynamics during the cage trapping is a non-local collective process involving monomers beyond the nearest neighbours.Comment: 15 pages, 6 figure

Some statistics on permutations avoiding generalized patterns

In the last decade a huge amount of articles has been published studying pattern avoidance on permutations. From the point of view of enumeration, typically one tries to count permutations avoiding certain patterns according to their lengths. Here we tackle the problem of refining this enumeration by considering the statistics "first/last entry". We give complete results for every generalized patterns of type $(1,2)$ or $(2,1)$ as well as for some cases of permutations avoiding a pair of generalized patterns of the above types.Comment: 5 figure

The M\"obius function of the consecutive pattern poset

An occurrence of a consecutive permutation pattern $p$ in a permutation $\pi$ is a segment of consecutive letters of $\pi$ whose values appear in the same order of size as the letters in $p$. The set of all permutations forms a poset with respect to such pattern containment. We compute the M\"obius function of intervals in this poset, providing what may be called a complete solution to the problem. For most intervals our results give an immediate answer to the question. In the remaining cases, we give a polynomial time algorithm to compute the M\"obius function. In particular, we show that the M\"obius function only takes the values -1, 0 and 1.Comment: 10 pages, 2 figure

Relationship Lending, Distance and Efficiency in a Heterogeneous Banking System

During the last decades banks have progressively moved towards centralized and hierarchical organizational structures. Therefore, the investigation of the determinants of bank efficiency and relationships with the functional distance between the bank head-quarter and operational units have become increasingly important. This paper extends the literature on bank efficiency examining the impact of different bank business models on the efficiency of the Italian banks, distinguished by size and type over the period 2006-2009. Using a stochastic frontier approach, the intertemporal relationships between bank efficiency and some key variables, as distance and income diversification (used as proxies of different organizational banking models) are investigated. Results suggest that organizational structure significantly affects cost efficiency, being different between bank groups.relationship lending; bank groups; credit risk; stochastic frontiers; panel data