5,991 research outputs found

    Application of large eddy interaction model to a mixing layer

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    The large eddy interaction model (LEIM) is a statistical model of turbulence based on the interaction of selected eddies with the mean flow and all of the eddies in a turbulent shear flow. It can be utilized as the starting point for obtaining physical structures in the flow. The possible application of the LEIM to a mixing layer formed between two parallel, incompressible flows with a small temperature difference is developed by invoking a detailed similarity between the spectra of velocity and temperature

    Delaminated areas beneath organic coating: A local electrochemical impedance approach

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    Local electrochemical impedance mapping was used to investigate delamination phenomena at the steel/epoxy-vinyl primer interface. The delamination occurred from an artificial defect(cutter scribing) and from ageing in a salt spray chamber. The samples were taken from the salt spray chamber after 20, 30 and 50 days of exposure. To observe delamination after ageing, the corrosion product layers were removed by a cathodic polarization at −1.5 V/SCE for 4 h. A non-aged reference sample was tested for comparison. Mapping was performed at 5 kHz. Initiation and propagation of the delamination were clearly observed. The delaminated surface areas measured by visual observations after the removal of the coating were lower than those determined by local electrochemical impedance mapping. The delamination mechanisms were discussed with reference to literature data

    Global Solutions for Incompressible Viscoelastic Fluids

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    We prove the existence of both local and global smooth solutions to the Cauchy problem in the whole space and the periodic problem in the n-dimensional torus for the incompressible viscoelastic system of Oldroyd-B type in the case of near equilibrium initial data. The results hold in both two and three dimensional spaces. The results and methods presented in this paper are also valid for a wide range of elastic complex fluids, such as magnetohydrodynamics, liquid crystals and mixture problems.Comment: We prove the existence of global smooth solutions to the Cauchy problem for the incompressible viscoelastic system of Oldroyd-B type in the case of near equilibrium initial dat

    Notes on rabbinic epitaphs: I

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    Jüdische Grabsteinepigraphik: R. Yosef Trani (1568-1639), R. Akiva Eger (d. 1837), R. David Hoffmann (d. 1921

    Corrosion protection of carbon steel by an epoxy resin containing organically modified clay

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    This study focusses on the use of montmorillonite clay (MMT) treated with an organic compound (aminotrimethylphosphonic acid (ATMP)) and dispersed in an epoxy resin to improve corrosion protection of carbon steel. X-ray diffraction was performed to verify that the individual silicate layers were separated and dispersed in the epoxy resin. Corrosion resistance of the coated steel was evaluated by electrochemical impedance spectroscopy (EIS) and local electrochemical impedance spectroscopy (LEIS). Three systems were tested: the epoxy clear-coat, the epoxy resin containing 2 wt.% clay and the epoxy resin containing 2 wt.% clay modified byATMP (ATMP-modified clay). From conventional EIS, it was shown that the incorporation of clay or ATMP-modified clay in the epoxy matrix significantly improved the barrier properties of the coating. The corrosion resistance of the carbon steel coated by the epoxy resin containing ATMP-modified clay was higher than that obtained for the system containing non-treated clay. Local electrochemical measurements performed on scratched samples revealed the inhibitive role of ATMP at the carbon steel/coating interface

    Jesus, Judgment, and the People of God: Learning from Jesus and the Reformed Tradition about the Works Required for Salvation

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    Editor\u27s Note: Dr. Joshua E. Leim presented this paper at the Prodigal Love of God Conference, in celebration of the 400th anniversary of the Canons of Dort, April 2019, sponsored by Dordt University and co-sponsored by the Lilly Fellowship Program, as a regional conference

    Application of large eddy interaction model to channel flow

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    A procedure utilizing an expansion of proper orthogonal functions (or modes) to predict a fully developed flow in channel is derived. To examine numerical and conceptual difficulties, preliminary computations are performed with assigned mean velocity, and turbulence is expressed with only the first mode. The nonlinear interactions of the components of the first mode are treated specifically, with the influence of higher modes neglected; this treatment required adjustment of the skewness and effective Reynolds number to assure energy equilibrium of the first mode. Computational results show that the first mode possesses the structural character similar to that of the entire flow

    Vestibular schwannoma and ipsilateral endolymphatic hydrops: an unusual association

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    Vestibular schwannoma and endolymphatic hydrops are two conditions that may present with similar audio-vestibular symptoms. The association of the two in the same patient represents an unusual nding that may lead clinicians to errors and delays in diagnosis and clinical management of affected subjects. We discuss the case of a patient with an intrameatal vestibular schwannoma reporting symptoms suggestive for ipsilateral endolymphatic hydrops. The patient presented with uctuating hearing loss, tinnitus, and acute rotatory vertigo episodes, and underwent a full audiological evaluation and imaging of the brain with contrast-enhanced Magnetic Resonance Imaging. Clinical audio-vestibular and radiological examination con rmed the presence of coexisting vestibular schwannoma and endolymphatic hydrops. Hydrops was treated pharmacologically; vestibular schwannoma was monitored over time with a wait and scan protocol through conventional MRI. The association of vestibular schwannoma and endolymphatic hydrops is rare, but represents a possible nding in clinical practice. It is therefore recommended investigating the presence of inner ear disorders in patients with vestibular schwannoma and, similarly, to exclude the presence of this condition in patients with symptoms typical of inner ear disorders

    Leim, Paul, Sr. (1835 - 1922)

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    This biographical summary was created by the Works Progress Administration (WPA) between 1936 and 1939

    Emmerich, John (1855 - 1914)

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    This biographical summary was created by the Works Progress Administration (WPA) between 1936 and 1939
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