1,721,089 research outputs found
Liquid crystal plasmonics
Full text linkThe interplay between gold nanoparticles (AuNPs) and liquid crystals (LCs) opens compelling solutions that produce a win-win solution for both classes of materials. AuNPs are successfully utilised to induce a controlled phase change of LCs and, simultaneously, LCs make an active control of the AuNPs optical properties. LC plasmonics generates hybrid materials that could revolutionise next-generation optical and photonic applications in this framework
Active plasmonic nanomaterials
No full textPlasmonic nanoparticles (NPs) represent an outstanding class of nanomaterials that have the capability to localize light at the nanoscale by exploiting a phenomenon called “localized plasmon resonance” This book reviews recent efforts devoted to the utilization of NPs in many research fields, such as photonics, optics, and plasmonics. In this framework, a particular interest is devoted to “active plasmonics,” a quite broad concept that indicates those applications in which NPs play an “active” role, such as the realization of gain-assisted means, utilization of NPs embedded in liquid crystalline and flexible materials, and exploitation of renewable solar energy. The book puts together contributions from outstanding international research groups in the field of plasmonic nanomaterials
L’aumento dell’astensione in una elezione di crisi
No full textIl capitolo analizza la partecipazione elettorale alle elezione 2013 incrociando dati amministrativi sullo stato dell'economia italiana con dati di survey sulla percezione individuale della propria condizione economica. Si sofferma inoltre sull'evoluzione della propensione a votare nel periodo precedente alle elezioni analizzando dati panel
Economic Crisis and European Elections: An Alteration of the Electoral Cycle?
No full textIn questo articolo analizziamo la misura in cui le elezioni europee del 2009, svoltesi a seguito della grave crisi dei mercati internazionali, differiscono dalle precedenti. I nostri interrogativi di ricerca riguardano da un lato la presenza di effetti di delegittimazione della UE (attraverso astensionismo, voto di protesta, frammentazione, successo di partiti anti-Europei) e dall’altro lato il risultato dei governi nazionali. Analiticamente, il modello delle elezioni di second’ordine che colloca le elezioni europee all’interno dei cicli elettorali nazionali viene considerato operando una contestualizzazione storica dei risultati delle elezioni europee in otto paesi (Austria, Francia, Germania, Italia, Olanda, Polonia, Regno Unito, Spagna). I dati non mostrano evidenza di un particolare incremento dell’astensionismo elettorale nè del voto di protesta rispetto a quanto verificatosi nelle precedenti elezioni europee. Tuttavia le elezioni del 2009 si collocano nelle tendenze di medio periodo verso instabilità e frammentazione e, probabilmente per effetto della crisi economica, si caratterizzano per le particolari difficoltà anche per i governi in carica, compresi quelli che si stanno avvicinando alla fine del loro ciclo elettorale e che quindi, nelle precedenti elezioni di second’ordine ma senza crisi economica, tendevano a recuperare consensi: una dinamica che, sebbene in modo disomogeneo, appare evidente anche dall’analisi dei trend nelle inchieste di opinione
Computational fluid dynamics simulation of heat transfer from densely packed gold nanoparticles to isotropic media
Full text linkThis work aims to determine and compare heat generation and propagation of densely packed gold nanoparticles (Au NPs) induced by a resonant laser beam (532 nm) according to the Mie theory. The heat flux propagation is transferred into the materials, which here are: silica glass; soda-lime-silica glass; borosilicate glass; polymethyl methacrylate (PMMA); polycarbonate (PC); and polydimetylosiloxane (PDMS). This analysis aims to select the optimum material serving as a base for using photo-thermoablation. On the other hand, research focused only on Newtonian heat transfer in gold, not on non-Fourier ones, like the Cattaneo approach. As a simulation tool, a computational fluid dynamics code with the second-order upwind algorithm is selected. Results reveal a near-Gaussian and Gaussian temperature distribution profile during the heating and cooling processes, respectively. Dependence between the maximum temperature after irradiation and the glass thermal conductivity is observed confirming the Fourier law. Due to the maximum heating area, the borosilicate or soda-lime glass, which serves as a base, shall represent an excellent candidate for future experiments
Recent advances towards point-of-care devices for fungal detection. Emphasizing the role of plasmonic nanomaterials in current and future technologies
Full text linkFungal infections are a significant global health problem, particularly affecting individuals with weakened immune systems. Moreover, as uncontrolled antibiotic and immunosuppressant use increases continuously, fungal infections have seen a dramatic increase, with some strains developing antibiotic resistance. Traditional approaches to identifying fungal strains often rely on morphological characteristics, thus owning limitations, such as struggles in identifying several strains or distinguishing between fungal strains with similar morphologies. This review explores the multifaceted impact of fungi infections on individuals, healthcare providers, and society, highlighting the often-underestimated economic burden and healthcare implications of these infections. In light of the serious constraints of traditional fungal identification methods, this review discusses the potential of plasmonic nanoparticle-based biosensors for fungal infection identification. These biosensors can enable rapid and precise fungal pathogen detection by exploiting several readout approaches, including various spectroscopic techniques, colorimetric and electrochemical assays, as well as lateral-flow immunoassay methods. Moreover, we report the remarkable impact of plasmonic Lab on a Chip technology and microfluidic devices, as they recently emerged as a class of advanced biosensors. Finally, we provide an overview of smartphone-based Point-of-Care devices and the associated technologies developed for detecting and identifying fungal pathogens
Plasmon resonance tunability of gold nanoparticles embedded in a confined cholesteric liquid crystal host
No full textGold nanoparticles have been dissolved in a cholesteric liquid crystal and then infiltrated in a micro-periodic polymeric structure. This has been realized by combining a holographic step and a microfluidic etching process. The spectral behavior of the nano-composite soft-structure has been investigated in the UV-Vis range for two different polarization directions of an impinging probe light and in presence of external perturbations (electric field, temperature variation). Obtained results show a highly tunable plasmonic response of the material. Copyright © 2012 Taylor and Francis Group, LLC
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