776 research outputs found

    Mikheyev-Smirnov-Wolfenstein Effect for Linear Electron Density

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    When the electron density is a linear function of distance, it is known that the MSW equations for two neutrino species can be solved in terms of known functions. It is shown here that more generally, for any number of neutrino species, these MSW equations can be solved exactly in terms of single integrals. While these integrals cannot be expressed in terms of known functions, some of their simple properties are obtained. Application to the solar neutrino problem is briefly discussed.Comment: 14 page

    Dalle partiture ai samples

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    The digital revolution is breaking with a millennial musical culture based on reading and writing notes. So far, art music has been composed in the medium of musical scores, and today, not only in popular music but also in art music, samples are becoming the new medium of composition. This is the theory that I would like to defend in the following with a double strategy. On the one hand, I will introduce five pieces of New Music, which were created between 2014 and 2018 and were composed with instrumental samples. On the other hand, I will develop a historical-philosophical argument that explains why such sample compositions actually have a prominent musical-historical significance.La rivoluzione digitale sta cambiando una cultura musicale millenaria basata sul leggere e scrivere note. Finora, la musica colta (quella cio√® considerata di alto valore estetico) veniva composta utilizzando le partiture come mezzo, laddove oggi, non solo nella popular music ma anche nella stessa musica colta, i samples (campioni) stanno diventando il nuovo mezzo compositivo. Questa √® la teoria che vorrei sostenere qui, per mezzo di una duplice strategia: da un lato, presenter√≤ cinque brani di musica contemporanea, composti tra il 2014 e il 2018 per mezzo di samples strumentali; dall‚Äôaltro, vorrei sviluppare una trattazione storico-filosofica che spieghi perch√© tali composizioni giochino di fatto un ruolo di notevole importanza nella storia della musica

    A new variant of symmetry breaking for quark mass matrices

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    We propose a definite pattern for the breaking of a discrete flavor symmetry of the quark mass matrices which is caused by the masses of the first two generations of quarks. We discuss the consequences of this proposal for the KM matrix

    Factor copula models for item response data

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    Factor or conditional independence models based on copulas are proposed for multivariate discrete data such as item responses. The factor copula models have interpretations of latent maxima/minima (in comparison with latent means) and can lead to more probability in the joint upper or lower tail compared with factor models based on the discretized multivariate normal distribution (or multidimensional normal ogive model). Details on maximum likelihood estimation of parameters for the factor copula model are given, as well as analysis of the behavior of the log-likelihood. Our general methodology is illustrated with several item response data sets, and it is shown that there is a substantial improvement on existing models both conceptually and in fit to data

    A cost-effective colourimetric assay for quantifying hydrogen peroxide in honey

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    Honey is a natural product with many beneficial properties including antimicrobial action. Production of hydrogen peroxide (H2O2) in diluted honey is central to this action. Here, we describe an optimized method for measuring levels of H2O2 in honey. This method is based on established methods, with the level of dilution, the time between dilution and reading the assay, and aeration of the samples during the assay identified as critical points for ensuring reliability and reproducibility. The method is cost-effective and easy to perform using common laboratory equipment. Using this method, we quantified the hydrogen peroxide content of five different, unprocessed polyfloral honeys collected in NC, USA. Our results show that H2O2 production by these honeys varies greatly, with some samples producing negligible levels of H2O2. We assessed the effect of colour on the assay by measuring the recovery of spiked H2O2 from light and dark honey and from serially diluted dark corn syrup, and found the amount of H2O2 that could be detected was lower in dark corn syrup and darker honey samples

    GJETC report 2020 : German-Japanese cooperation in energy research ; supporting the closure of implementation gaps ; key results and policy recommendations

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    The German-Japanese Energy Transition Council (GJETC) was established in 2016 by experts from research institutions, energy policy think tanks, and practitioners in Germany and Japan. The objectives and main activities of the Council and the supporting secretariats are to identify and analyze current and future issues regarding policy frameworks, markets, infrastructure, and technological developments in the energy transition, and to hold Council meetings to exchange ideas and propose better policies and strategies. In its second project phase (2018-2020), the GJETC had six members from academia on the Japanese side, and eight members on the German side, with one Co-Chair from each country. From October 2018 to March 2020, the GJETC worked on and debated six topics: 1) Digitalization and the energy transition. 2) Hydrogen society. 3) Review of German and Japanese long-term energy scenarios and their evaluation mechanism. 4) Buildings, energy efficiency, heating/cooling. 5) Integration costs of renewable energies. 6) Transport and sector coupling. The outputs and the recommendations of the second phase of the GJETC are summarized in this report

    The periphrastic perfect in Ancient Greek: a diachronic mental space analysis

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    In the present article, I apply Fauconniers mental spaces theory to the diachronic analysis of the Ancient Greek periphrastic perfect. I argue that the periphrastic construction started out as a resultative perfect, with FOCUS and EVENT located in the same mental space. I show that, contrary to what is sometimes believed, the construction was not limited to a purely stative meaning, but underwent the cross-linguistically attested semantic shift from resultative to anterior, whereby an additional non-FOCUS EVENT-space was constructed. In fourth-century Classical Greek, we witness the further extension of the periphrastic construction with regard to semantics, morphology and discourse context. I close the article with some remarks on the possible aoristicisation of the periphrastic perfect

    First narrow-band search for continuous gravitational waves from known pulsars in advanced detector data

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    Spinning neutron stars asymmetric with respect to their rotation axis are potential sources of continuous gravitational waves for ground-based interferometric detectors. In the case of known pulsars a fully coherent search, based on matched filtering, which uses the position and rotational parameters obtained from electromagnetic observations, can be carried out. Matched filtering maximizes the signalto- noise (SNR) ratio, but a large sensitivity loss is expected in case of even a very small mismatch between the assumed and the true signal parameters. For this reason, narrow-band analysis methods have been developed, allowing a fully coherent search for gravitational waves from known pulsars over a fraction of a hertz and several spin-down values. In this paper we describe a narrow-band search of 11 pulsars using data from Advanced LIGO’s first observing run. Although we have found several initial outliers, further studies show no significant evidence for the presence of a gravitational wave signal. Finally, we have placed upper limits on the signal strain amplitude lower than the spin-down limit for 5 of the 11 targets over the bands searched; in the case of J1813-1749 the spin-down limit has been beaten for the first time. For an additional 3 targets, the median upper limit across the search bands is below the spin-down limit. This is the most sensitive narrow-band search for continuous gravitational waves carried out so far
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