875 research outputs found

    Reply to Agger and Kowalski

    Get PDF

    Depositional Environments and Sequence Stratigraphy of a Breathitt Group Exposure, U.S. 25E, Flat Lick, Kentucky

    Get PDF
    The Pennsylvanian fluvial deltaic Breathitt Group is exposed along U.S. 25E near Flat Lick, Ky. This exposure is ideal for field trips because of the quality of the exposure, its accessibility, the range of facies present, and its potential for demonstrating principles of outcrop-based sequence-stratigraphic interpretation. Eight facies are present and represent deposition in fluvial, delta-plain, and delta-front environments. Several facies contain an abundance of trace fossils, and a wide range of sedimentary structures are also present. Flooding surfaces are well developed in the delta front and delta plain and are characterized by abrupt contacts with distal, deeper-water deltaic environments overlying proximal, shallower-water deltaic environments. Major flooding surfaces display evidence of condensation, including firmgrounds and enrichment of authigenic minerals such as siderite. At this exposure, most parasequence sets display progradational stacking and are interpreted as highstand systems tracts. Two sequence boundaries are present that may represent two different scales of sequences. The upper sequence boundary is more obvious and is characterized by a prominent erosional surface and is overlain by multistory fluvial channels. The lower and more subtle sequence boundary is interpreted as an interfluve surface marked by a bleached paleosol

    Universal Impedance Fluctuations in Wave Chaotic Systems

    Full text link
    We experimentally investigate theoretical predictions of universal impedance fluctuations in wave chaotic systems using a microwave analog of a quantum chaotic infinite square well potential. Our approach emphasizes the use of the radiation impedance to remove the non-universal effects of the particular coupling from the outside world to the scatterer. Specific predictions that we test include the probability distribution functions (PDFs) of the real (related to the local density of states in disordered metals) and imaginary parts of the normalized cavity impedance, the equality of the variances of these PDFs, and the dependence of the universal PDFs on a single control parameter characterizing the level of loss. We find excellent agreement between the statistical data and theoretical predictions.Comment: 5 pages, 3 figures, submitted to Phys. Rev. Let

    Robust Informatics Infrastructure Required For ICME: Combining Virtual and Experimental Data

    Get PDF
    With the increased emphasis on reducing the cost and time to market of new materials, the need for robust automated materials information management system(s) enabling sophisticated data mining tools is increasing, as evidenced by the emphasis on Integrated Computational Materials Engineering (ICME) and the recent establishment of the Materials Genome Initiative (MGI). This need is also fueled by the demands for higher efficiency in material testing; consistency, quality and traceability of data; product design; engineering analysis; as well as control of access to proprietary or sensitive information. Further, the use of increasingly sophisticated nonlinear, anisotropic and or multi-scale models requires both the processing of large volumes of test data and complex materials data necessary to establish processing-microstructure-property-performance relationships. Fortunately, material information management systems have kept pace with the growing user demands and evolved to enable: (i) the capture of both point wise data and full spectra of raw data curves, (ii) data management functions such as access, version, and quality controls;(iii) a wide range of data import, export and analysis capabilities; (iv) data pedigree traceability mechanisms; (v) data searching, reporting and viewing tools; and (vi) access to the information via a wide range of interfaces. This paper discusses key principles for the development of a robust materials information management system to enable the connections at various length scales to be made between experimental data and corresponding multiscale modeling toolsets to enable ICME. In particular, NASA Glenn's efforts towards establishing such a database for capturing constitutive modeling behavior for both monolithic and composites material

    Universal Statistics of the Scattering Coefficient of Chaotic Microwave Cavities

    Full text link
    We consider the statistics of the scattering coefficient S of a chaotic microwave cavity coupled to a single port. We remove the non-universal effects of the coupling from the experimental S data using the radiation impedance obtained directly from the experiments. We thus obtain the normalized, complex scattering coefficient whose Probability Density Function (PDF) is predicted to be universal in that it depends only on the loss (quality factor) of the cavity. We compare experimental PDFs of the normalized scattering coefficients with those obtained from Random Matrix Theory (RMT), and find excellent agreement. The results apply to scattering measurements on any wave chaotic system.Comment: 10 pages, 8 Figures, Fig.7 in Color, Submitted to Phys. Rev.

    Interleukin (IL)–12 and IL-23 Are Key Cytokines for Immunity against Salmonella in Humans

    Get PDF
    Patients with inherited deficiency of the interleukin (IL)–12/IL-23–interferon (IFN)–g axis show increased susceptibility to invasive disease caused by the intramacrophage pathogens salmonellae and mycobacteria. We analyzed data on 154 patients with such deficiency. Significantly more patients with IL-12/IL-23–component deficiency had a history of salmonella disease than did those with IFN-g–component deficiency. Salmonella disease was typically severe, extraintestinal, and caused by nontyphoidal serovars. These findings strongly suggest that IL-12/IL-23 is a key cytokine for immunity against salmonella in humans and that IL-12/IL-23 mediates this protective effect partly through IFN-g–independent pathways. Investigation of the IL-12/IL-23–IFN-g axis should be considered in patients with invasive salmonella disease

    Chronic Invasive Aspergillosis caused by Aspergillus viridinutans

    Get PDF
    Aspergillus viridinutans, a mold phenotypically resembling A. fumigatus, was identified by gene sequence analyses from 2 patients. Disease was distinct from typical aspergillosis, being chronic and spreading in a contiguous manner across anatomical planes. We emphasize the recognition of fumigati-mimetic molds as agents of chronic or refractory aspergillosis

    Stratigraphic Column of the Kope and Fairview Formations, Kentucky 445, Brent, Kentucky

    Get PDF
    The Upper Ordovician Kope Formation is exposed over a broad area of southwestern Ohio, southeastern Indiana, and northern Kentucky (Weir and others, 1984). Roadcuts along Ky. 445 near Brent (Figs. 2-3) and adjacent roadcuts along Interstate 275 expose a nearly complete section of the Kope Formation as well as the overlying Fairview Formation
    • …
    corecore