1,369 research outputs found

    Quantum radiation from superluminal refractive index perturbations

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    We analyze in detail photon production induced by a superluminal refractive index perturbation in realistic experimental operating conditions. The interaction between the refractive index perturbation and the quantum vacuum fluctuations of the electromagnetic field leads to the production of photon pairs.Comment: 4 page

    Radiation-induced edge effects in deep submicron CMOS transistors

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    The study of the TID response of transistors and isolation test structures in a 130 nm commercial CMOS technology has demonstrated its increased radiation tolerance with respect to older technology nodes. While the thin gate oxide of the transistors is extremely tolerant to dose, charge trapping at the edge of the transistor still leads to leakage currents and, for the narrow channel transistors, to significant threshold voltage shift-an effect that we call Radiation Induced Narrow Channel Effect (RINCE)

    Spacetime geometries and light trapping in travelling refractive index perturbations

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    In the framework of transformation optics, we show that the propagation of a locally superluminal refractive index perturbation (RIP) in a Kerr medium can be described, in the eikonal approximation, by means of a stationary metric, which we prove to be of Gordon type. Under suitable hypotheses on the RIP, we obtain a stationary but not static metric, which is characterized by an ergosphere and by a peculiar behaviour of the geodesics, which are studied numerically, also accounting for material dispersion. Finally, the equation to be satisfied by an event horizon is also displayed and briefly discussed.Comment: 14 pages, 7 figure

    Food Neophobia or Distrust of Novelties? Exploring consumers' attitudes toward GMOs, insects and cultured meat

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    The food industry is constantly challenged to find new ideas to satisfy the increasingly specific consumer demand. However, innovative food products do not always become part of consumption habits or create a market. One of the major sources of resistance to novelty lies in the attitude of the consumer, who in many cases may be suspicious or hostile as a result of specific ideologies, overly attached to tradition, or affected by neophobia. This paper analyzes the construct of food neophobia (the "unwillingness to try new foods") in its phenomenology and its actual power to explain hostility to innovation in the agri-food sector. The limits of the concept, which is not always sufficient to shed light on the many reasons that could underlie the rejection of certain foods, will also be discussed. In addition, we review the recent literature on Europeans' attitude toward novel foods and innovation including Genetically modified organisms (GMOs), cultivated meat and insects as food. This literature reveals a number of paradoxes in consumers' behavior, and in the many complex conditions underpinning the success of innovation in food production. These conditions can only be understood by reconstructing the meanings consumers assign to food, and are often embedded in larger social and political frameworks

    Extreme Events in Resonant Radiation from Three-dimensional Light Bullets

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    We report measurements that show extreme events in the statistics of resonant radiation emitted from spatiotemporal light bullets. We trace the origin of these extreme events back to instabilities leading to steep gradients in the temporal profile of the intense light bullet that occur during the initial collapse dynamics. Numerical simulations reproduce the extreme valued statistics of the resonant radiation which are found to be intrinsically linked to the simultaneous occurrence of both temporal and spatial self-focusing dynamics. Small fluctuations in both the input energy and in the spatial phase curvature explain the observed extreme behaviour.Comment: 5 pages, 5 figures, submitte

    On the nature of spatiotemporal light bullets in bulk Kerr media

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    We present a detailed experimental investigation, which uncovers the nature of light bullets generated from self-focusing in a bulk dielectric medium with Kerr nonlinearity in the anomalous group velocity dispersion regime. By high dynamic range measurements of three-dimensional intensity profiles, we demonstrate that the light bullets consist of a sharply localized high-intensity core, which carries the self-compressed pulse and contains approximately 25% of the total energy, and a ring-shaped spatiotemporal periphery. Sub-diffractive propagation along with dispersive broadening of the light bullets in free space after they exit the nonlinear medium indicate a strong space-time coupling within the bullet. This finding is confirmed by measurements of spatiotemporal energy density flux that exhibits the same features as stationary, polychromatic Bessel beam, thus highlighting the physical nature of the light bullets

    Analogue Gravity and ultrashort laser pulse filamentation

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    Ultrashort laser pulse filaments in dispersive nonlinear Kerr media induce a moving refractive index perturbation which modifies the space-time geometry as seen by co-propagating light rays. We study the analogue geometry induced by the filament and show that one of the most evident features of filamentation, namely conical emission, may be precisely reconstructed from the geodesics. We highlight the existence of favorable conditions for the study of analogue black hole kinematics and Hawking type radiation.Comment: 4 pages, revised versio

    Tackling Prejudice and Discrimination Towards Families with Same-Sex Parents: An Exploratory Study in Italy

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    Though studies have shown that the sexual orientation of parents does not influence their parenting skills or the well-being of their children, prejudice against same-sex families is still very widespread. Research has not sufficiently explored the ways in which parents tackle this prejudice. Using qualitative methodologies, in particular textual analyses, this study has analysed the discourse used by same-sex families to handle the prejudices that they face. The results highlighted that conflicts, which may even be ideological in nature, are sometimes created between traditional families and “atypical” families. These often result in estrangement and isolation from their own family and the communities to which they belong, in turn damaging the growth of the children involved. Furthermore, means for moving beyond conflict, sharing experiences and effectively tackling prejudices are also discussed
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