Surface Plasmon States in Inhomogeneous Media at Critical and Subcritical Metal Concentrations

Semicontinuous metal-dielectric films are composed of a wide range of metal clusters of various geometries—sizes as well as structures. This ensures that at any given wavelength of incident radiation, clusters exist in the film that will respond resonantly, akin to resonating nanoantennas, resulting in the broad optical response (absorption) that is a characteristic of semicontinuous films. The physics of the surface plasmon states that are supported by such systems is complex and can involve both localized and propagating plasmons. This chapter describes near-field experimental and numerical studies of the surface plasmon states in semicontinuous films at critical and subcritical metal concentrations and evaluates the local field intensity statistics to discuss the interplay between various eigenmodes

Towards local electromechanical probing of cellular and biomolecular systems in a liquid environment

Electromechanical coupling is ubiquitous in biological systems with examples ranging from simple piezoelectricity in calcified and connective tissues to voltage-gated ion channels, energy storage in mitochondria, and electromechanical activity in cardiac myocytes and outer hair cell stereocilia. Piezoresponse force microscopy (PFM) has originally emerged as a technique to study electromechanical phenomena in ferroelectric materials, and in recent years, has been employed to study a broad range of non-ferroelectric polar materials, including piezoelectric biomaterials. At the same time, the technique has been extended from ambient to liquid imaging on model ferroelectric systems. Here, we present results on local electromechanical probing of several model cellular and biomolecular systems, including insulin and lysozyme amyloid fibrils, breast adenocarcinoma cells, and bacteriorhodopsin in a liquid environment. The specific features of SPM operation in liquid are delineated and bottlenecks on the route towards nanometer-resolution electromechanical imaging of biological systems are identified.Comment: 37 pages (including refs), 8 figure

Piezoelectric response of nanoscale PbTiO3 in composite PbTiO3-CoFe2O4 epitaxial films

Piezoelectric properties of PbTiO3 in 1/3PbTiO(3)-2/3CoFe(2)O(4) transverse epitaxial nanostructures on differently oriented SrTiO3 were analyzed using conventional and switching-spectroscopy piezoelectric force microscopy. The results confirmed that the individual PbTiO3 nanocolumns in the CoFe2O4 matrix exhibit a detectable piezoelectric response regardless of substrate orientation. For the 100\ and 110\ orientations, a bias of +/- 10 V produced ferroelectric domain switching; however, no switching was observed for the 111\ films. Small values of piezoelectric constants d(zz)((100))approximate to 11 pm/V, d(zz)((110))approximate to 5 pm/V, and d(zz)((111))approximate to 3pm/V are attributed to the weak intrinsic response of the nano-PbTiO3 under strong mechanical and depolarizing-field constraints in the composite films. (c) 2008 American Institute of Physics.Author has checked copyright11/12/13 R

Near-Field Intensity Correlations in Semicontinuous Metal Films

This paper presents the first experimental study of near-field intensity correlations in metal-dielectric systems in regimes where localization and delocalization are expected. Significant differences are observed between the spatial intensity correlations functions in metal-dielectric systems and those of purely dielectric random media

Crisi della legge e Litigation Strategy. Corti, diritti e bioetica

Il tema della crisi rappresenta ormai un tòpos della letteratura scientifica giusfilosofica. Negli ultimi decenni tale crisi, intesa soprattutto come crisi del modello legicentrico otto-novecentesco, si è acuita in coincidenza con l'avvento dell'età dei diritti e con il conseguente corroborarsi (almeno nello spazio giuridico europeo) delle corti, tanto domestiche, quanto sovrastatali. In questo scenario, il volume ricostruisce il contributo giudiziario italiano in tema di fine vita (caso Englaro), di procreazione medicalmente assistita (legge 40 del 2004) e di regolamentazione delle unioni civili (legge 'Cirinnà'), individuando tre diverse modalità (supplenza, censura, iniziativa) di definizione della dialettica tra rappresentanza democratica e giustizia, in un percorso che, attraverso la giudizializzazione della politica, evidenzia il peso sempre crescente dei singoli cittadini, dei gruppi di interesse, degli avvocati, delle corti nei processi di produzione delle norme giuridiche, anche nei Paesi di civil law

Near-Field Intensity Correlations in Semicontinuous Metal Films

Spatial intensity correlation functions of semicontinuous metal-dielectric films of varying metal concentration, p, were obtained from near-field microscopy. The data shows a transition from propagation to localization and back to propagation of optical excitations with increase in p

Near-Field Intensity Correlations in Semicontinuous Metal Films

Spatial intensity correlation functions of semicontinuous metal-dielectric films of varying metal concentration, p, were obtained from near-field microscopy. The data shows a transition from propagation to localization and back to propagation of optical excitations with increase in p