1,123 research outputs found
David A. Norris
No full textPublicity photograph taken of David Norris at Greenfield Lake in Wilmington, NC.
David Archie Norris (1944- ) is a lecturer, historian, genealogist, author and artist in Wilmington. He has published a book and many magazine articles on the Civil War, particularly concerning events in North Carolina. He is a past president of the Cape Fear Civil War Round Table, and currently has his art displayed at the WHQR radio station
Effective wave numbers for thermo-viscoelastic media containing random configurations of spherical scatterers
No full textThe dispersion relation is derived for the coherent waves in fluid or elastic media supporting viscous and thermal effects and containing randomly distributed spherical scatterers. The formula obtained is the generalization of Lloyd and Berry’s [Proc. Phys. Soc. London 91, 678–688 (1967)], the latter being limited to fluid host media, and it is the three-dimensional counterpart of that derived by Conoir and Norris [Wave Motion 47, 183–197 (2010)] for cylindrical scatterers in an elastic host medium.Peer reviewe
Helen Norris Papers, MSS.4084
No full textAbstract: Typescript copies of several plays, poems, and novelsScope and Content Note: The collection contains typescript copies of several unpublished novels as well as plays, essays, and poems written by Helen Norris.Biographical/Historical Note: Helen Norris, daughter of Elmer Wharton and Louise Brown Norris, was born in Miami, Florida, on June 22, 1916. She moved with her family to Montgomery, Alabama, at an early age. She attended the University of Alabama and earned her bachelor's and master's degrees in 1938 and 1940 respectively. Her thesis was a draft of what became her first novel, Something More Than Earth, which was published in 1940. Shortly after graduating, she married and moved to Birmingham, Alabama, and later Sylacauga, Alabama. The couple had three sons: Tom, Stuart, and Wilson. The marriage ended in divorce in 1965, and in 1966, after a year working toward a PhD at Duke University, she returned to Montgomery, where she taught English at Huntingdon College. After her retirement in 1979, she devoted her time once again to her writing.Norris published five novels and five collections of short stories. Two of her short stories have been made into television films, the first by HBO in 1988 and the other by PBS in 1999. She won several literary awards including the Andrew Lytle Prize for Best Short Story (twice) and had stories included in the O. Henry Awards Prize Stories in 1984, 1985, 1987, and 1991. She was awarded the Harper Lee Award for Alabama's Distinguished Writer in 2000, the Alabama Library Association's Alabama Author Award in 2002, and was designated the sixth Poet Laureate of Alabama from 1999-2003.In 2003, Norris moved to Black Mountain, North Carolina. She died on November 18, 2013
Judge Norris S. Barratt papers
No full textThe Papers of Judge Norris S. Barratt, a Philadelphia lawyer and author of Barratt's Chapel and Methodism, consist of fourteen letters he received from James H. Preston sent during Preston's first term as mayor of Baltimore, Maryland, (1911-1915) and three of Barratt's letters sent to Preston. The letters are both political and personal in nature. Also included are an invitation to a Symbolic Silver Service for James Cardinal Gibbons, Archbishop of Baltimore, at Baltimore's City Hall and two pamphlets on Baltimore and Mayor Preston
Effective shear speed in two-dimensional phononic crystals
No full textThe quasistatic limit of the antiplane shear-wave speed ('effective speed') c in 2D periodic lattices is studied. Two new closed-form estimates of c are derived by employing two different analytical approaches. The first proceeds from a standard background of the plane wave expansion (PWE). The second is a new approach, which resides in x-space and centers on the monodromy matrix (MM) introduced in the 2D case as the multiplicative integral, taken in one coordinate, of a matrix with components being the operators with respect to the other coordinate. On the numerical side, an efficient PWE-based scheme for computing c is proposed and implemented. The analytical and numerical findings are applied to several examples of 2D square lattices with two and three high contrast components, for which the new PWE and MM estimates are compared with the numerical data and with some known approximations. It is demonstrated that the PWE estimate is most efficient in the case of densely packed stiff inclusions, especially when they form a symmetric lattice, while in general it is the MM estimate that provides the best overall fitting accuracy.Peer reviewe
Elastodynamics of radially inhomogeneous spherically anisotropic elastic materials in the Stroh formalism
No full textA method is presented for solving elastodynamic problems in radially inhomogeneous elastic materials with spherical anisotropy, i.e. materials such that cijkl = cijkl(r) in a spherical coordinate system. The time harmonic displacement field u is expanded in a separation of variables form with dependence on described by vector spherical harmonics with r-dependent amplitudes. It is proved that such separation of variables solution is generally possible only if the spherical anisotropy is restricted to transverse isotropy with the principal axis in the radial direction, in which case the amplitudes are determined by a first-order ordinary differential system. Restricted forms of the displacement field, such as u admit this type of separation of variables solutions for certain lower material symmetries. These results extend the Stroh formalism of elastodynamics in rectangular and cylindrical systems to spherical coordinates.Peer reviewedReceived July 29, 2011; accepted September 16, 2011; published online December 23, 2011. Print publication date February 2012. Manuscript dated September 14, 2011
Nonlinear shear wave interaction at a frictional interface: Energy dissipation and generation of harmonics
No full textAnalytical and numerical modelling of the nonlinear interaction of shear wave with a frictional interface is presented. The system studied is composed of two homogeneous and isotropic elastic solids, brought into frictional contact by remote normal compression. A shear wave, either time harmonic or a narrow band pulse, is incident normal to the interface and propagates through the contact. Two friction laws are considered and their influence on interface behavior is investigated : Coulomb's law with a constant friction coefficient and a slip-weakening friction law which involves static and dynamic friction coefficients. The relationship between the nonlinear harmonics and the dissipated energy, and their dependence on the contact dynamics (friction law, sliding and tangential stress) and on the normal contact stress are examined in detail. The analytical and numerical results indicate universal type laws for the amplitude of the higher harmonics and for the dissipated energy, properly non-dimensionalized in terms of the pre-stress, the friction coefficient and the incident amplitude. The results suggest that measurements of higher harmonics can be used to quantify friction and dissipation effects of a sliding interface.Peer reviewe
Integral identities for reflection, transmission and scattering coefficients
No full textSeveral integral identities related to acoustic scattering are presented. In each case the identity involves the integral over frequency of a physical quantity. For instance, the integrated transmission loss, a measure of the transmitted acoustic energy through an inhomogeneous layer, is shown to have a simple expression in terms of spatially averaged physical quantities. Known identities for the extinction cross section and for the acoustic energy loss in a slab with a rigid backing, are shown to be special cases of a general procedure for finding such integral identities.Peer reviewe
On the quasistatic effective elastic moduli for elastic waves in three-dimensional phononic crystals
No full textEffective elastic moduli for 3D solid-solid phononic crystals of arbitrary anisotropy and oblique lattice structure are formulated analytically using the plane-wave expansion (PWE) method and the recently proposed monodromy-matrix (MM) method. The latter approach employs Fourier series in two dimensions with direct numerical integration along the third direction. As a result, the MM method converges much quicker to the exact moduli in comparison with the PWE as the number of Fourier coefficients increases. The MM method yields a more explicit formula than previous results, enabling a closed-form upper bound on the effective Christoffel tensor. The MM approach significantly improves the efficiency and accuracy of evaluating effective wave speeds for high-contrast composites and for configurations of closely spaced inclusions, as demonstrated by three-dimensional examples.Peer reviewe
Got Acedia? Who Cares? A panel discussion of Kathleen Norris\u27 book Acedia & me : a marriage, monks, and a writer\u27s life
No full textoai:digitalcommons.csbsju.edu:collegevilleinstitute_lectures-1000Kathleen Norris, author of Acedia and Me: A Marriage, Monks, and A Writer\u27s Life for a panel discussion on acedia (a state of being unable to care). Norris\u27s presentation on acedia was followed by responses from two monastics: Br. Paul-Vincent Niebauer and S. Josue Behnen. Kathleen is serving as the 2011 Kilian McDonnell Writer-in-Residence at the Collegeville Institute. Sponsored by the Collegeville Institute
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