3,553 research outputs found

    Massive neutrinos and dark energy

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    We consider the impact of the Heidelberg-Moscow claim for a detection of neutrino mass on the determination of the dark energy equation of state. By combining the Heidelberg-Moscow result with the WMAP 3-years data and other cosmological datasets we constrain the equation of state to -1.67< w <-1.05 at 95% c.l., While future data are certainly needed for a confirmation of the controversial Heildelberg-Moscow claim, our result shows that future laboratory searches for neutrino masses may play a crucial role in the determination of the dark energy properties.Comment: 3 pages, 1 figure, Talk given by Paolo Serra at the Neutrino Oscillation Workshop NOW2006, Otranto, Italy, September 9-16 200

    How children talk about events:Implications for eliciting and analyzing eyewitness reports

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    Legal and social service professionals often question whether various features of young witnesses’ responses during interviews are characteristic of children’s event reports or whether these features are concerning findings that reflect degraded memory, outside influence, or other phenomena. To assist helping professionals and researchers who collect data through interviews, we aggregated findings from child eyewitness studies and revisited transcript sets to construct fifteen principles that capture how children talk about events. These principles address children’s earliest event narratives, how children report information as interviews unfold and typical features of their narratives, threats to the accuracy of answers, the influence of interviewers’ language on children’s styles of reporting, how testimonies compare across multiple interviews and multiple witnesses to the same event, and the structure of accurate and inaccurate reports. A summary table highlights the implications of these principles for interviewers and the decision-makers who analyze children’s reports

    Mass-varying neutrino in light of cosmic microwave background and weak lensing

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    We aim to constrain mass-varying neutrino models using large scale structure observations and produce forecast for the Euclid survey. We investigate two models with different scalar field potential and both positive and negative coupling parameters \beta. These parameters correspond to growing or decreasing neutrino mass, respectively. We explore couplings up to |\beta|<5. In the case of the exponential potential, we find an upper limit on Ωνh2\Omega_\nu h^2<0.004 at 2-σ\sigma level. In the case of the inverse power law potential the null coupling can be excluded with more than 2-\sigma significance; the limits on the coupling are \beta>3 for the growing neutrino mass and \beta<-1.5 for the decreasing mass case. This is a clear sign for a preference of higher couplings. When including a prior on the present neutrino mass the upper limit on the coupling becomes |\beta|<3 at 2-σ\sigma level for the exponential potential. Finally, we present a Fisher forecast using the tomographic weak lensing from an Euclid-like experiment and we also consider the combination with the cosmic microwave background (CMB) temperature and polarisation spectra from a Planck-like mission. If considered alone, lensing data is more efficient in constraining Ων\Omega_\nu with respect to CMB data alone. There is, however, a strong degeneracy in the \beta-Ωνh2\Omega_\nu h^2 plane. When the two data sets are combined, the latter degeneracy remains, but the errors are reduced by a factor ~2 for both parameters.Comment: 5 pages, 6 figures. Now published in A&A 500, 657-665 (2009

    High speed solid rotor permanent magnet machines: concept and design

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    This paper proposes a novel solid rotor topology for an Interior Permanent Magnet (IPM) machine, adopted in this case for an aircraft starter-generator design. The key challenge in the design is to satisfy two operating conditions which are: a high torque at start and a high speed at cruise. Conventional IPM topologies which are highly capable of extended field weakening are found to be limited at high speed due to structural constraints associated with the rotor material. To adopt the IPM concept for high speed operation, it is proposed to adopt a rotor constructed from semi-magnetic stainless steel, which has a higher yield strength than laminated silicon steel. To maintain minimal stress levels and also minimize the resultant eddy current losses due to the lack of laminations, different approaches are considered and studied. Finally, to achieve a better tradeoff between the structural and electromagnetic constraints, a novel slitted approach is implemented on the rotor. The proposed rotor topology is verified using electromagnetic, static structural and dynamic structural Finite Element (FE) analyses. An experiment is performed to confirm the feasibility of the proposed rotor. It is shown that the proposed solid rotor concept for an IPM fulfils the design requirements whilst satisfying the structural, thermal and magnetic limitations

    Evaluación de la estructura del pavimento flexible en el CP Rinconada Km 13 hasta La Laguna Km 17, Santa - Áncash, 2021. Propuesta de mejora.

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    La presente investigación titulada “Evaluación de la estructura del pavimento flexible en el CP Rinconada Km 13 hasta La Laguna Km 17, Santa - Áncash, 2021. Propuesta de mejora.”, tiene como finalidad saber la condición del pavimento en relación a su estado superficial y su estado estructural. De este modo, se plantío el siguiente objetivo general que es evaluar la estructura del pavimento flexible en el CP Rinconada Km 13 hasta La Laguna Km 17, Santa - Áncash, 2021. Es así, que esta investigación es tipo aplicada con enfoque cuantitativo porque aplica conceptos que ya están establecidos, así mismo, es diseño no experimental de corte transversal - descriptiva, porque los datos son obtenidos y medidos in situ tal como se encuentran sin manipularlos ni alterarlos. La técnica empleada fue la observación, para identificar las fallas; y así también, la misma se empleó para el estudio de tráfico. Asimismo, se determinó la evaluación superficial por el método PCI y VIZIR mediante las fichas técnicas indicadas en manuales y normas. De forma similar, se determinó la evaluación estructural mediante los ensayos realizados en laboratorio. En general, esta investigación da como resultado que mediante la metodología PCI, la condición del pavimento calculado es 46 siendo clasificado de estado Regular, asimismo, se indica que mediante la metodología VIZIR la condición del pavimento calculado es 3 siendo clasificado en estado Regular o Marginal. Sobre la evaluación de la estructura del pavimento, se puede indicar que la carpeta asfáltica, la capa base y sub base, no llegan a cumplir con lo establecido en la normas y manuales del MTC. En lo propuesto en esta investigación, se elaboró el diseño de un pavimento flexible mediante la guía AASHTO-93, lo cual consta con una carpeta de 2 pulg., una capa base de 12 pulg y una capa sub base de 12 pulg. Teniendo un paquete estructural de 26 pulg

    The Grizzly, December 10, 2015

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    Museum Studies Minor Coming in Spring 2016 • Students Demand Diversity • BEAR Pitch Competition Crowns Winners • International Perspective: Differences in Cultural Cleaning Routines • Flapjacks for Finals • Artists\u27 Tribute to Chadwick • Bringing Safety to the Students • Opinions: Protests Prompt Hate on Yik Yak; Why Syrian Refugees Don\u27t Pose a Threat • Outrunning the Competition • Men\u27s Basketball Set to Take on Division I Pennhttps://digitalcommons.ursinus.edu/grizzlynews/1679/thumbnail.jp

    The Galaxy Structure-Redshift Relationship

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    There exists a gradual, but persistent, evolutionary effect in the galaxy population such that galaxy structure and morphology change with redshift. This galaxy structure-redshift relationship is such that an increasingly large fraction of all bright and massive galaxies at redshifts 2 < z < 3 are morphologically peculiar at wavelengths from rest-frame ultraviolet to rest-frame optical. There are however examples of morphologically selected spirals and ellipticals at all redshifts up to z ~ 3. At lower redshift, the bright galaxy population smoothly transforms into normal ellipticals and spirals. The rate of this transformation strongly depends on redshift, with the swiftest evolution occurring between 1 < z < 2. This review characterizes the galaxy structure-redshift relationship, discusses its various physical causes, and how these are revealing the mechanisms responsible for galaxy formation.Comment: 20 pages, 8 figures. Invited Review to appear in "Penetrating Bars Through Masks of Cosmic Dust: The Hubble Tuning Fork Strikes A New Note", ed. D. Block et a

    Joint 3D modelling of the polarized Galactic synchrotron and thermal dust foreground diffuse emission

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    We present for the first time a coherent model of the polarized Galactic synchrotron and thermal dust emissions which are the main diffuse foreground for the measurement of the polarized power spectra of the CMB fluctuations with the Planck satellite mission. We produce 3D models of the Galactic magnetic field including regular and turbulent components, and of the distribution of matter in the Galaxy, relativistic electrons and dust grains. By integrating along the line of sight we construct maps of the polarized Galactic synchrotron and thermal dust emission for each of these models and compare them to currently available data. We consider the 408 MHz all-sky continuum survey, the 23 GHz band of the Wilkinson Microwave Anisotropy Probe and the 353 GHz Archeops data.}{The best-fit parameters obtained are consistent with previous estimates in the literature based only on synchrotron emission and pulsar rotation measurements. They allows us to reproduce the large scale structures observed on the data. Poorly understood local Galactic structures and turbulence make difficult an accurate reconstruction of the observations in the Galactic plane. Finally, using the best-fit model we are able to estimate the expected polarized foreground contamination at the Planck frequency bands. For the CMB bands, 70, 100, 143 and 217 GHz, at high Galactic latitudes although the CMB signal dominates in general, a significant foreground contribution is expected at large angular scales. In particular, this contribution will dominate the CMB signal for the B modes expected from realistic models of a background of primordial gravitational waves
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