4,045 research outputs found

    Surface Plasmon Excitation of Second Harmonic light: Emission and Absorption

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    We aim to clarify the role that absorption plays in nonlinear optical processes in a variety of metallic nanostructures and show how it relates to emission and conversion efficiency. We define a figure of merit that establishes the structure's ability to either favor or impede second harmonic generation. Our findings suggest that, despite the best efforts embarked upon to enhance local fields and light coupling via plasmon excitation, nearly always the absorbed harmonic energy far surpasses the harmonic energy emitted in the far field. Qualitative and quantitative understanding of absorption processes is crucial in the evaluation of practical designs of plasmonic nanostructures for the purpose of frequency mixing

    Consumo di suolo e sviluppo locale sostenibile

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    The research examines the issue of waste of land in metropolitan area of Palermo and offers a description of the current situation through a systematic data. Target is knowledge of waste of land, to develop indicators of the phenomenon and to develop appropriate reflection on the effects of environmental and landscape change, suggest urban policies for sustainable local development

    On homogeneous CR manifolds and their CR algebras

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    In this paper we show some results on homogeneous CR manifolds, proved by introducing their associated CR algebras. In particular, we give different notions of nondegeneracy (generalizing the usual notion for the Levi form) which correspond to geometrical properties for the corresponding manifolds. We also give distinguished equivariant CR fibrations for homogeneous CR manifolds. In the second part of the paper we apply these results to minimal orbits for the action of a real form of a semisimple Lie group \^G on a flag manifold \^G/Q.Comment: 14 pages. AMS-LaTeX v2: minor revisio

    Local anaesthesia efficacy as postoperative analgesia for open shoulder instability surgery. a prospective randomised controlled study

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    Background and objectives: The aim of present study was to evaluate for the first time, the clinical effect of local anaesthetic infiltration as postoperative analgesia in open shoulder surgery for anterior-inferior instability. The comparison of the local infiltration and interscalenic brachial plexus block to a control group test the local anaesthetic efficacy in this surgery. Methods: 78 patients scheduled for open shoulder surgery were enrolled and randomly assigned to one of three groups: local infiltration anaesthesia (LIA), interscalenic brachial plexus block (IBPB) and control (C). All patients received standardized general anaesthesia and all injections were performed with the same dose and volume of anaesthetic. The number boluses delivered by a PCA pump applied at the end of surgery and the visual analogue score (VAS) at 0, 2, 4, 6, 12, 18 and 24 hours after intervention were recorded. A patient satisfaction score was also assessed. Results: Mean bolus consumption of the rescue analgesic, compared to C, was significantly less both in the LIA and IBPB groups (P<0.05). The IBPB group showed VAS scores that were significantly better than C group at all time points (P<0.05). The VAS scores for LIA group were clinically comparable to IBPB, and only at the 2 and 6 hours, postoperative time points there were no significant differences found in respect to the C group. IBPB and LIA showed comparable patient satisfaction scores. Conclusion: The local anaesthetic infiltration as postoperative analgesia appears to be a clinically valid alternative, statistically comparable to IBPB, with no clinical meaningful adverse effects

    Human-technology integration with industrial conversational agents: A conceptual architecture and a taxonomy for manufacturing

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    Conversational agents are systems with great potential to enhance human-computer interaction in industrial settings. Although the number of applications of conversational agents in many fields is growing, there is no shared view of the elements to design and implement for chatbots in the industrial field. The paper presents the combination of many research contributions into an integrated conceptual architecture, for developing industrial conversational agents using Nickerson's methodology. The conceptual architecture consists of five core modules; every module consists of specific elements and approaches. Furthermore, the paper defines a taxonomy from the study of empirical applications of manufacturing conversational agents. Indeed, some applications of chatbots in manufacturing are available but those have never been collected in single research. The paper fills this gap by analyzing the empirical cases and presenting a qualitative analysis, with verification of the proposed taxonomy. The contribution of the article is mainly to illustrate the elements needed for the development of a conversational agent in manufacturing: researchers and practitioners can use the proposed conceptual architecture and taxonomy to more easily investigate, define, and develop all the elements for chatbot implementation

    Ge-Doped microstructured multicorefiber for customizable supercontinuum generation

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    Supercontinuum generation in a multicore fiber in which several uncoupled cores were doped with dissimilar concentrations of germanium was studied experimentally. Germanium doping provided control over the separation between the zero-dispersion wavelength and the 1064-nm wavelength of a Q-switched Nd:YAG pump laser. Supercontinua generated independently in each core of the same piece of fiber displayed clear and repeatable differences due to the influence of germanium doping on refractive index and four-wave mixing. The spectral evolution of the subnanosecond pump pulses injected into the different cores was accurately reproduced by numerical simulations
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