173 research outputs found

    SMMR Simulator radiative transfer calibration model. 2: Algorithm development

    Get PDF
    Passive microwave measurements performed from Earth orbit can be used to provide global data on a wide range of geophysical and meteorological phenomena. A Scanning Multichannel Microwave Radiometer (SMMR) is being flown on the Nimbus-G satellite. The SMMR Simulator duplicates the frequency bands utilized in the spacecraft instruments through an amalgamate of radiometer systems. The algorithm developed utilizes data from the fall 1978 NASA CV-990 Nimbus-G underflight test series and subsequent laboratory testing

    SMMR simulator radiative transfer calibration model. 1: Derivation

    Get PDF
    There are no author-identified significant results in this report

    Parallel simulations of reacting two-phase flows - A DoD Grand Challenge progress report

    Full text link
    Parallel simulation of unsteady turbulent combustion is carried out for a range of precursor test problems leading to the development of a new methodology for reacting two-phase flows. Simulations are carried out using large-eddy simulations (LES) which allows full spatio-temporal resolution of all scales larger than the grid resolution with the unresolved small-scales modeled by a localized dynamic one-equation subgrid models. For two-phase applications, Lagrangian tracking of a range of droplets is carried out and is fully coupled to the Eulerian gas phase flow. An extension of this approach to accurately deal with small-scale scalar mixing and chemical reactions has been carried out using an innovative model that is implemented within each LES cell, to account for the effects of small-scale mixing and molecular diffusion on the chemical processes. The first year's effort focused on validating this methodology using both simple and complex test configurations. Highly optimized parallel LES codes are used for these studies. In addition to parallel scaleup data, results discussed in this paper include stagnation point premixed flame, opposed jet diffusion flame, highly swirling premixed flame in a General Electric combustor and two-phase mixing and vaporization in mixing layers. Comparison with experimental data wherever possible, clearly demonstrates the unique capabilities of the new subgrid combustion LES model

    Resolving the neural circuits of anxiety

    Get PDF
    Although anxiety disorders represent a major societal problem demanding new therapeutic targets, these efforts have languished in the absence of a mechanistic understanding of this subjective emotional state. While it is impossible to know with certainty the subjective experience of a rodent, rodent models hold promise in dissecting well-conserved limbic circuits. The application of modern approaches in neuroscience has already begun to unmask the neural circuit intricacies underlying anxiety by allowing direct examination of hypotheses drawn from existing psychological concepts. This information points toward an updated conceptual model for what neural circuit perturbations could give rise to pathological anxiety and thereby provides a roadmap for future therapeutic development.National Institute of Diabetes and Digestive and Kidney Diseases (U.S.) (NIH Director’s New Innovator Award DP2-DK-102256-01)National Institute of Mental Health (U.S.) (NIH) R01-MH102441-01)JPB Foundatio

    Hydrographic data from the OPTOMA Program: OPTOMA11, 5-June-5 August, 1984

    Get PDF
    The six cruises and one aircraft flight comprising OPTOMA11 were undertaken in June, July and August 1984 to sample two subdomains of the California Current. This report presents the hydrographic data, acquired by XBT, AXBT and CTD casts, from the cruises and the flight.Research project "Ocean Prediction Through Observations, Modeling and Analysis" sponsored by the Physical Oceanography Program of the Office of Naval Research under Program Element 61153N.http://archive.org/details/hydrographicdata011wittN000148WR24051NAApproved for public release; distribution is unlimited

    Cornish identities and migration: a multi-scalar approach

    Get PDF
    The definitive version is available at www.blackwell-synergy.com. 24 month embargo by the publisher. Article will be released July 2009.In this article we argue that theories of transnationalism have value in exploring the historical context of migration and that historical contexts help to shape such theoretical conceptualizations. Historians of migration have now begun to engage more directly with the literature of transnationalism, focusing on the networks that linked settler and home communities. Here we add to this by examining a nineteenth-century migrant community from a British region through the lens of transnationalism, applying the concept to the case of the Cornish, whose economic specialization produced culturally distinct Cornish communities on the mining frontiers of North America, Australia and South Africa. In doing so, we bring together the issues of scale and time. We review the multiple levels of the Cornish transnational space of the late nineteenth century, which exhibited aspects of both core transnationalism and translocalism. This waned, but in the later twentieth century, a renewed interest in a transnational Cornish identity re-emerged, articulating with changing identity claims in Cornwall itself. To capture better the experience of the Cornish over these two very different phases of transnationalism we identify another subset of transnationalism - that of transregionalism.Leverhulme Trus

    On LEM/LES methodology for two-phase flows

    Full text link
    A two-phase subgrid combustion model developed earlier has been evaluated for applicability in large-eddy simulations (LES). Direct Numerical Simulations (DNS) of two-phase isotropic turbulence in the presence of passive, momentum-coupled and vaporizing droplets has been extensively studied to form a base-line database. Current DNS results agree with earlier studies and show that the presence of droplets increase the kinetic energy and dissipation at the small scales. LES for these same cases were also carried out to investigate what modifications are needed to incorporate the small-scale turbulence modifications seen in DNS of two-phase flows. LES subgrid modeling for two-phase mixing within the context of the new subgrid combustion model is also addressed

    Randomized trial of thymectomy in myasthenia gravis

    Get PDF
    • …
    corecore