Institution
Naval Surface Warfare Center
Facility•Washington D.C., District of Columbia, United States•
About: Naval Surface Warfare Center is a facility organization based out in Washington D.C., District of Columbia, United States. It is known for research contribution in the topics: Sonar & Radar. The organization has 2855 authors who have published 3697 publications receiving 83518 citations. The organization is also known as: NSWC.
Papers published on a yearly basis
Papers
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TL;DR: In this article, a constitutive equation based on the generalized concept of thermally activated flow units is developed to describe the stress-strain behavior of polymers as a function of temperature, strain-rate, and superposed hydrostatic pressure under conditions in which creep and long-term relaxation effects are negligible.
Abstract: A constitutive equation based on the generalized concept of thermally activated flow units is developed to describe the stress–strain behavior of polymers as a function of temperature, strain-rate, and superposed hydrostatic pressure under conditions in which creep and long-term relaxation effects are negligible. The equation is shown to describe the principal features of the dynamic stress–strain behavior of polytetrafluoroethylene and, also, the yield stress of polymethylmethacrylate as a function of temperature and strain rate. A key feature of the model, not utilized in previous constitutive equation descriptions, is an inverse shear stress dependence of the shear activation volume. In contrast to metal deformation behavior, an enhanced strain hardening with increasing strain at higher strain rates and pressures is accounted for by an additional rate for immobilization of flow units. The influence of hydrostatic pressure enters through a pressure activation volume and also through the flow unit immobilization term. The thermal activation model is combined with a temperature dependent Maxwell–Weichert linear viscoelastic model that describes the initial small strain part of the stress strain curve.
23 citations
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TL;DR: In this paper, a radial configuration of baselines is used to determine the best values of the vertical components ({eta, ǫ) at the central station for a given geodetic level.
Abstract: The capabilities of the Global Positioning System (GPS) for accurately determining geodetic quantities are well established. Nevertheless, no comparison between deflections of the vertical as determined through GPS with leveling and values conventionally computer by astrogeodetic methods has yet been published. This investigation demonstrates that the accurate deflections of the vertical components ({eta}, {xi}) can be obtained independently of classical astronomic observations by combining geodetic leveling with satellite GOS positioning. The approach uses a radial configuration of baselines to determine the best (in a least square sense) values of ({eta}, {xi}) at the central station.
23 citations
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TL;DR: In this article, an analysis of hourly 30-second acoustic samples obtained from a seafloor hydrophone included manual identification of physical, biological, and human-made acoustic sources and measuring received sound pressure levels.
23 citations
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TL;DR: In this article, a planar pulse of roughly 2μsec duration explosively initiated by a flying plate was observed to saturate above 300 kbar while that for Inconel continued to increase steadily.
Abstract: Sheet samples of pure nickel and Inconel 600 alloy (76% Ni, 16% Cr, 7% Fe) containing a fine precipitate were simultaneously shock loaded in sandwich assemblies at pressures of 50, 100, 150, 200, and 370 kbar by a planar pulse of roughly 2‐μsec duration explosively initiated by a flying plate. The residual microhardness of the nickel was observed to saturate above 300 kbar while that for Inconel continued to increase steadily. Examination of the nickel substructures by transmission electron microscopy revealed a steadily decreasing cell size with increasing shock pressure; with almost no evidence of deformation twins at 370 kbar. The Inconel substructure was characterized by planar dislocation arrays which included an increasing concentration of dipoles and elongated loops to 200 kbar; while at 370 kbar deformation twins having an average thickness of 150 A and occupying 19% of the volume were observed. The coherent precipitates in the Inconel matrix were observed to become incoherent at pressures above 50 kbar, with the concomitant production of dislocation tangles and loops at the particle‐matrix interface. The precipitates were observed to enhance shock hardening by acting as sources for dislocation dipoles and elongated loops.
23 citations
Authors
Showing all 2860 results
Name | H-index | Papers | Citations |
---|---|---|---|
James A. Yorke | 101 | 445 | 44101 |
Edward Ott | 101 | 669 | 44649 |
Sokrates T. Pantelides | 94 | 806 | 37427 |
J. M. D. Coey | 81 | 748 | 36364 |
Celso Grebogi | 76 | 488 | 22450 |
David N. Seidman | 74 | 595 | 23715 |
Mingzhou Ding | 69 | 256 | 17098 |
C. L. Cocke | 51 | 312 | 8185 |
Hairong Qi | 50 | 327 | 9909 |
Kevin J. Hemker | 49 | 231 | 10236 |
William L. Ditto | 43 | 193 | 7991 |
Carey E. Priebe | 43 | 404 | 8499 |
Clifford George | 41 | 235 | 5110 |
Judith L. Flippen-Anderson | 40 | 205 | 6110 |
Mortimer J. Kamlet | 39 | 108 | 12071 |