66 research outputs found

    Neutrino Interferometry In Curved Spacetime

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    Gravitational lensing introduces the possibility of multiple (macroscopic) paths from an astrophysical neutrino source to a detector. Such a multiplicity of paths can allow for quantum mechanical interference to take place that is qualitatively different to neutrino oscillations in flat space. After an illustrative example clarifying some under-appreciated subtleties of the phase calculation, we derive the form of the quantum mechanical phase for a neutrino mass eigenstate propagating non-radially through a Schwarzschild metric. We subsequently determine the form of the interference pattern seen at a detector. We show that the neutrino signal from a supernova could exhibit the interference effects we discuss were it lensed by an object in a suitable mass range. We finally conclude, however, that -- given current neutrino detector technology -- the probability of such lensing occurring for a (neutrino-detectable) supernova is tiny in the immediate future.Comment: 25 pages, 1 .eps figure. Updated version -- with simplified notation -- accepted for publication in Phys.Rev.D. Extra author adde

    Overview of recent physics results from the National Spherical Torus Experiment (NSTX)

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    Polymorphism: an evaluation of the potential risk to the quality of drug products from the FarmĂĄcia Popular Rede PrĂłpria

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    Polymorphism in solids is a common phenomenon in drugs, which can lead to compromised quality due to changes in their physicochemical properties, particularly solubility, and, therefore, reduce bioavailability. Herein, a bibliographic survey was performed based on key issues and studies related to polymorphism in active pharmaceutical ingredient (APIs) present in medications from the Farmácia Popular Rede Própria. Polymorphism must be controlled to prevent possible ineffective therapy and/or improper dosage. Few mandatory tests for the identification and control of polymorphism in medications are currently available, which can result in serious public health concerns

    PLANT SECONDARY COMPOUNDS–A BASIS FOR NEW AVIAN REPELLENTS

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    Bird repellents that are effective have tended to be toxic, while those that are relatively nontoxic have tended to be ineffective. There is a need for repellents that work well and safely. Interest has focused on the natural chemical defenses used by plants to defend themselves from herbivores. Preferences of bullfinches in orchards for different pear cultivars were correlated with biochemical differences between cultivars. A class of plant secondary compounds has been isolated and shown to be physiologically active against bullfinch and pigeon gut enzymes, and also to deter feeding in the laboratory. The physiological and biochemical mechanisms responsible for their repellency are under investigation
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