7,334 research outputs found

    Non-monotonic entanglement of physical EM field states in non-inertial frames

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    We develop a general technique to analyse the quantum effects of acceleration on realistic spatially-localised electromagnetic field states entangled in the polarization degree of freedom. We show that for this setting, quantum entanglement may build up as the acceleration increases, providing a clear signature of the quantum effects of relativistic acceleration.Comment: 5 pages, 3 figure

    A 300 GHz "Always-in-Focus" Focusing System for Target Detection

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    A focusing system for a 300 GHz radar with 5 m target distance and 10 mm diameter spot size resolution is proposed. The focusing system is based on a Gaussian telescope scheme and its main parameters have been de¬signed using Gaussian beam quasi-optical propagation theory with an in-house developed MATLAB® based analysis tool. Then, this approach has been applied to a real focusing system based on two elliptical mirrors in order to reduce the distortion and cross-polar level and a plane mirror to provide scanning capabilities. The over¬all system has been simulated with a full-wave electromag¬netic simulator and its behavior is presented. With this approach, the focusing system always works "in-focus" since the only mirror that is rotated when scanning is the output plane mirror, so the beam is almost not distorted. The design process, although based in the well-known Gaussian beam quasi-optical propagation theory, provides a fast and accurate method and minimizes the overall size of the mirrors. As a consequence, the size of the focusing system is also reduced

    The interaction between jets and clouds in the 3CR galaxies

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    From the HST/WFPC2 3CR Snapshot Survey, data taken with the filter F555W, F702W and narrow-ramp, a set of galaxies with noticeable extended structure were selected (e.g. 3C 79, 3C 135, 3C 234, etc). All of these objects show large regions of [OIII] λ 5007˚A emission (narrow ramp filter) and the broad-band filters data show similar structures indicating the presence of strong emission in several lines over these regions. The morphology observed seems to be related (e.g. same position angle, direct overlapping or similar shape) with the radio-jet. For some candidates with these properties GMOS/Gemini spectroscopy was taken. These data (both HST direct imaging and Gemini spectroscopy) can be tested with diagnostic diagrams and total UV photons budget to understand the source of energy that is ionizing the gas. This source of ionization was commonly believed to be the UV photons emitted by the powerful active galactic nuclei (AGN), but several of these objects show clearly that shocks produced by the radio jet are the main cause of the observed gas line emission. We show in this work, the results obtained over some of these radio-galaxies: 3C 135, 3C 180, 3C 234 and 3C 284.Fil: Hägele, G. F.. Universidad Autónoma de Madrid; EspañaFil: Feinstein Baigorri, Carlos. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; ArgentinaFil: Macchetto, D. F.. Space Telescope Science Institute; Estados UnidosFil: Montero, F.. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; Argentin

    Preferences, classification and intuitionistic fuzzy sets.

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    Abstract In this paper we analyze some models being used for fuzzy preference representation and fuzzy classification, putting them in relation to intuitionistic fuzzy sets. In particular, preference modeling is viewed as a classification problem, which is deeply related to intuitionistic fuzzy sets. In particular, the interest of a more sophisticated model based upon intuitionistic fuzzy sets, viewed as a general classification problem, is suggested. In this way some limitation of intuitionistic fuzzy sets might be overcome

    Thirty Femtograms Detection of Iron in Mammalian Cells

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    Inorganic nanomaterials and particles with enhanced optical, mechanical or magnetic attributes are currently being developed for a wide range of applications. Safety issues have been formulated however concerning their potential cyto- and genotoxicity. For in vivo and in vitro experimentations, recent developments have heightened the need of simple and facile methods to measure the amount of nanoparticles taken up by cells or tissues. In this work, we present a rapid and highly sensitive method for quantifying the uptake of iron oxide nanoparticles in mammalian cells. Our approach exploits the digestion of incubated cells with concentrated hydrochloric acid reactant and a colorimetric based UV-Visible absorption technique. The technique allows the detection of iron in cells over 4 decades in masses, from 0.03 to 300 picograms per cell. Applied on particles of different surface chemistry and sizes, the protocol demonstrates that the coating is the key parameter in the nanoparticle/cell interactions. The data are corroborated by scanning and transmission electron microscopy and stress the importance of resiliently adsorbed nanoparticles at the plasma membrane.Comment: 18 pages, 6 figure

    Supervised Quantum Learning without Measurements

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    We propose a quantum machine learning algorithm for efficiently solving a class of problems encoded in quantum controlled unitary operations. The central physical mechanism of the protocol is the iteration of a quantum time-delayed equation that introduces feedback in the dynamics and eliminates the necessity of intermediate measurements. The performance of the quantum algorithm is analyzed by comparing the results obtained in numerical simulations with the outcome of classical machine learning methods for the same problem. The use of time-delayed equations enhances the toolbox of the field of quantum machine learning, which may enable unprecedented applications in quantum technologies
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