4,186 research outputs found

    Flavoured leptogenesis: a successful thermal leptogenesis with N_1 mass below 10^8 GeV

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    We prove that taking correctly into account the lepton flavour dependence of the CP asymmetries and washout processes, it is possible to obtain successful thermal leptogenesis from the decays of the second right-handed neutrino. The asymmetries in the muon and tau-flavour channels are then not erased by the inverse decays of the lightest right-handed neutrino, N_1. In this way, we reopen the possibility of ``thermal leptogenesis'' in models with a strong hierarchy in the right-handed Majorana masses that is typically the case in models with up-quark--neutrino Yukawa unification.Comment: 5 pages, no figures. References added, referencing correcte

    Leptogenesis beyond the limit of hierarchical heavy neutrino masses

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    We calculate the baryon asymmetry of the Universe in thermal leptogenesis beyond the usual lightest right-handed (RH) neutrino dominated scenario (N_1DS) and in particular beyond the hierarchical limit (HL), M_1 << M_2 << M_3, for the RH neutrino mass spectrum. After providing some orientation among the large variety of models, we first revisit the central role of the N_1DS, with new insights on the dynamics of the asymmetry generation and then discuss the main routes departing from it, focusing on models beyond the HL. We study in detail two examples of `strong-strong' wash-out scenarios: one with `maximal phase' and the limit of very large M_3, studying the effects arising when delta_2=(M_2-M_1)/M_1 is small. We extend analytical methods already applied to the N_1DS showing, for example, that, in the degenerate limit (DL), the efficiency factors of the RH neutrinos become equal with the single decay parameter replaced by the sum. Both cases disprove the misconception that close RH neutrino masses necessarily lead to a final asymmetry enhancement and to a relaxation of the lower bounds on M_1 and on the initial temperature of the radiation-dominated expansion. We also explain why leptogenesis tends to favor normal hierarchy compared to inverted hierarchy for the left-handed neutrino masses.Comment: 30 pages, 8 figures; corrected typo in Eq. (67); shortened Introduction, Section 3 and Conclusions; one figure removed; added 2 references; to appear in JCA

    Simultaneous estimation of etodolac and thiocolchicoside in bulk and in tablet formulation by UV-spectrophotometry

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    Two simple, rapid and reproducible simultaneous equation and Q-Analysis UV-Spectrophotometric methods have been developed for simultaneous estimation of Etodolac (ETO) and Thiocolchicoside (THC) in combined tablet dosage form. The methods involved solving simultaneous equations and Q-value Analysis based on measurement of absorbance at wavelengths, 223 (λmax of ETO), 259.4 nm (λmax of THC) and 236 nm (Iso-absorptive point). Linearity was found in the concentration range of 1-6 μg/mL and 4 - 24 μg/mL for ETO & THC respectively with coefficient correlation 0.9998 & 0.9992. The amount of drugs estimated by proposed methods are in excellent agreement with label claimed. Further-more, the methods were applied for the determination of ETO and THC in spiked human urine. The degradation behavior of ETO and THC was investigated under acid hydrolysis, alkali hydrolysis, photo and oxidative degradation. The samples subsequently generated were used for degradation studies using the developed method. Thiocolchicoside was found to degrade extensively under alkali hydrolysis and unaffected by other stress conditions while ETO was found to be stable in all stress conditions. The methods were validated according to ICH guidelines. The method, suitable for routine quality control, has been successfully applied to the determination of both drugs in commercial brands of tablets

    Step-by-step implementation of BIM-LCA: A case study analysis associating defined construction phases with their respective environmental impacts

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    Building Information Modelling (BIM) supports construction processes by dealing with the variety and complexity of design in a single virtual model. The model may also be complemented by the static and energy performance of buildings. Facing the growing demand of sustainability strategies in the construction sector, the consideration of environmental information within the planning process influences the decision making of planners and stakeholders. Nevertheless, the life cycle assessment of buildings has been so far excluded in BIM, due to the high variety of accurate information and time required. In this paper, a systematic framework is presented and applied to a case study. BIM-LCA assists actors along the planning and designing phase, from the building conception as a whole, up to the elements\u27 details and materials\u27 definition. BIM and LCA intertwine in an application scheme of seven phases for integral planning and four levels of structural composition of a building. With respect to these, involved actors examine potential solutions through a tool which exploits alternative specifications in order to assess the environmental impacts. The goal of this paper is to demonstrate the application of a BIM-LCA model regarding decision making for reliable values of environmental impact in a given structural level of the building. The main findings of this framework are due to the multitude of actors and information orchestrated, namely to uncertainties which characterize the whole planning process and data handling. Through BIMLCA, actors are assisted by ensuring flexibility of models and consistency of results throughout planning and designing

    The BIM2LCA approach: An industry foundation classes (IFC)-based interface to integrate life cycle assessment in integral planning

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    An increasing degree of digitalization in construction planning offers significant potential for building life cycle assessment (LCA) to reduce access barriers, as well as the assessment effort itself. To realize the widespread application of LCA tools and their potential to effectively minimize life cycle impacts, an open approach is required that allows for flexible application of comprehensive LCA studies and early integration in planning processes. The authors present an approach for LCA integration in all phases of digital planning which aims at a DGNB (Deutsche Gesellschaft für nachhaltiges Bauen) certification based on the open Building Information Modeling (BIM) standard Industry Foundation Classes (IFC). The approach takes into account varying levels of development and resulting data availability during integral planning phases, as well as resulting LCA application contexts. It goes beyond existing strategies and allows one to consider both BIM and LCA software through a workflow based on a single data format. The assessment framework is operationalized through standardized interface development and technical realization following the information delivery manual (IDM) process standardized for IFC interfaces. The Extensible Markup Language (XML) schema, as a specific implementation for certification, provides the target system for LCA data requirements and is generalized to a planning phase specific IDM base table. The technical realization based on respective model view definitions and distributed data suggests a pathway to the standardization of LCA-IFC integration based on an open approach. The overall approach exemplarily applies to the “LERNZENTRUM” at the Karlsruhe Institute of Technology (KIT) campus. We conclude that an open BIM approach for LCA integration in model-based planning is feasible, but requires several adjustments in IFC, LCA, and planning practice. Adding a lifecycle element to the IFC to connect BIM and LCA provides comprehensive feedback for informed decision making based on environmental impact

    Prescriptions for the scaling variable of the nucleon structure function in nuclei

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    We tested several choices of the in-medium value of the Bjorken scaling variable assuming the nucleon structure function in nucleus to be the same as that of free nucleon. The results unambiguously show that it is different.Comment: 11 pages, 3 figures, 1 tabl

    First CNGS events detected by LVD

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    The CERN Neutrino to Gran Sasso (CNGS) project aims to produce a high energy, wide band νμ\nu_{\mu} beam at CERN and send it toward the INFN Gran Sasso National Laboratory (LNGS), 732 km away. Its main goal is the observation of the ντ\nu_{\tau} appearance, through neutrino flavour oscillation. The beam started its operation in August 2006 for about 12 days: a total amount of 7.6 10177.6~10^{17} protons were delivered to the target. The LVD detector, installed in hall A of the LNGS and mainly dedicated to the study of supernova neutrinos, was fully operating during the whole CNGS running time. A total number of 569 events were detected in coincidence with the beam spill time. This is in good agreement with the expected number of events from Montecarlo simulations.Comment: Accepted for publication by the European Physical Journal C ; 7 pages, 11 figure

    On-line recognition of supernova neutrino bursts in the LVD detector

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    In this paper we show the capabilities of the Large Volume Detector (INFN Gran Sasso National Laboratory) to identify a neutrino burst associated to a supernova explosion, in the absence of an "external trigger", e.g., an optical observation. We describe how the detector trigger and event selection have been optimized for this purpose, and we detail the algorithm used for the on-line burst recognition. The on-line sensitivity of the detector is defined and discussed in terms of supernova distance and electron anti-neutrino intensity at the source.Comment: Accepted for pubblication on Astroparticle Physics. 13 pages, 10 figure
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