2,436 research outputs found

    Coherent Baryogenesis and Nonthermal Leptogenesis: A comparison

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    We present a new mechanism for baryogenesis: at preheating after inflation fermions acquire a varying mass by their coupling to a time dependent field. Their CP-violating mass matrix can generate a charge asymmetry to be transformed into a lepton asymmetry through decay into standard model particles and heavy Majorana neutrinos. In a concrete model of hybrid inflation we compare ``coherent baryogenesis'' with nonthermal leptogenesis by perturbative decay of the inflation condensates.Comment: 6 pages, 2 figures, contribution to the Proceedings of Strong and Electroweak Matter 2004 (SEWM2004), Helsinki, Finland, June 16-19, 200

    Distinguishing Carrot's Characteristics by Near Infrared (NIR) Reflectance and Multivariate Data Analysis

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    Rosana G. Moreira, Editor-in-Chief; Texas A&M UniversityThis is a paper from International Commission of Agricultural Engineering (CIGR, Commission Internationale du Genie Rural) E-Journal Volume 6 (2004): N. Abu-Khalaf, B. Bennedsen and G. Bjorn. Distinguishing Carrot's Characteristics by Near Infrared (NIR) Reflectance and Multivariate Data Analysis. (March 2004

    Star-Formation in the Ultraluminous Infrared Galaxy F00183-7111

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    We report the detection of molecular CO(1-0) gas in F00183-7111, one of the most extreme Ultra-Luminous Infrared Galaxies known, with the Australia Telescope Compact Array. We measure a redshift of 0.3292 for F00183-7111 from the CO(1-0) line and estimate the mass of the molecular gas in 00183 to be 1 ×\times 1010^{10} M⊙_{\odot}. We find that F00183-7111 is predominately powered by the AGN and only ∌\sim14 per cent of the total luminosity is contributed by star-formation (SFR ∌\sim220 M⊙_{\odot} yr−1^{-1}). We also present an optical image of F00183-7111, which shows an extension to the East. We searched for star-formation in this extension using radio continuum observations but do not detect any. This suggests that the star-formation is likely to be predominately nuclear. These observations provide additional support for a model in which the radio emission from ULIRGs is powered by an intense burst of star-formation and by a radio-loud AGN embedded in its nucleus, both triggered by a merger of gas-rich galaxies.Comment: 5 pages, 2 figures, Accepted for publication in MNRAS Letters Accepted 2014 January 19. Received 2013 December 30; in original form 2013 November 2

    A theoretical exploration of the relationship between outsourcing and business/ict alignment

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    In this paper we examine the likely impact of two different outsourcing scenarios on business/ICT alignment. We argue that there is a need to put ICT outsourcing in a broader business context and that it has an important impact on how organisations align business and ICT. Based on previous literature we combine several conceptual models on both outsourcing and B/ICT alignment and identify the possible problem areas in each of these scenarios. The goal of this “theoretical exercise”, which is mainly based on argument, is to end the paper with a theoretical proposition which needs to be tested and backed by empirical data. Therefore, this paper should be regarded as the first step in a research process

    A Computational Study of the Distribution of Particles in a Lab-Scale CFB Boiler

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    When two-fluid modeling is used to predict riser flows there have been difficulties in predicting the solids hold up in risers represented by the correct pressure drop profile. A way of encountering this inherent problem in current Eulerian-Eulerian CFD modeling is to approximate the actual particle size distribution by using more particle phases instead of the current practice of using one mean diameter. For the lab-scale CFB investigated, CFD simulations show that a mal-distribution occurs in the CFB; the larger particles are retained in the riser, whereas the intermediate and small particles are distributed both in the return leg and the riser. Simulations using an altered particle size distribution, i.e. a larger amount of large particles, show significant improvements in the pressure profile in the bottom part of the riser

    High-current performance evaluation of DCCTs

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    The evaluation of high performance DCCT's to the ppm level has never been an easy task. With the LHC demanding currents up to 13 kA, a whole series of problems has arisen in the accurate measurement of these devices. In order to tackle these problems, new facilities have been designed for laboratory measurements under full power operating conditions. These include a high performance low voltage 20 kA power converter, quasi-coaxial bus-bar structures, Kusters Bridge range extenders and a novel bipolar 0 - 10 A current calibrator with resolution and linearity better than ± 0.5 ppm. This paper will present an overview of the complete facility and give more detail on the new current calibrator. Initial results will be presented, along with application areas which advance the state of the art in this field of measurements
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