Naval Surface Warfare Center

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: Radar & Sonar. The organization has 2855 authors who have published 3697 publications receiving 83518 citations. The organization is also known as: NSWC.

A small unmanned aerial system (UAS) for coastal atmospheric research: preliminary results from New Zealand

Abstract: Experiments conducted in the low-altitude coastal atmosphere in New Zealand have demonstrated the potential of a new unmanned aerial system (UAS) for meteorological research. The Kahu unmanned aerial vehicle flies autonomously using GPS and pre-programmed waypoints, collecting observations of air temperature and relative humidity that are relayed to a ground-station near-instantaneously. Experiments conducted in the Hauraki Gulf, Auckland, show that the Kahu's radio transmission system can successfully transmit data across the ocean surface at distances up to 25 km. Accuracy of the meteorological data collected by the UAS was assessed via a direct comparison with weather station sensors and radiosonde soundings at heights of up to 500 m in the Bay of Plenty. Close agreement between the UAS, radiosonde and weather station data suggests that the Kahu UAS has considerable scope as a new field research tool in New Zealand, capable of providing reliable atmospheric data that can complement and even su...

High Pressure Ignition and Combustion of Aluminum Hydride

Abstract: An experimental study was conducted to determine the high pressure ignition characteristics of α-aluminum hydride. Aluminum hydride particles were heated on a platinum filament at heating rates of approximately 1 × 105 K/s in a pressure vessel for pressures ranging up to about 7 MPa, in order to quantify the ignition temperature and to observe the ignition process. Experiments were conducted in air, argon, and nitrogen as the pressurizing environment. This study revealed that the dehydrogenation of aluminum hydride is not a function of pressure under the conditions tested. In addition, ignition temperatures were found to be approximately linearly related to pressure until pressures exceeded about 0.4 MPa, at which point they remained constant through the highest pressures tested. High speed imaging of the ignition process showed a dramatic change in the ignition behavior for pressures above 0.4 MPa, corresponding to what we believe is a threshold for H2/air autoginition or perhaps even an explosion limit....

Corrosion Characterization of Iron-Based High-Performance Amorphous-Metal Thermal-Spray Coatings

Abstract: New corrosion-resistant, iron-based amorphous metals have been identified from published data or developed through combinatorial synthesis, and tested to determine their relative corrosion resistance. Many of these materials can be applied as coatings with advanced thermal spray technology. Two compositions have corrosion resistance superior to wrought nickel-based Alloy C-22 (UNS N06022) in some very aggressive environments, including concentrated calcium-chloride brines at elevated temperature. One of these compositions, SAM1651, is discussed in detail to illustrate the promise of this general class of materials.

Optical-transition radiation measurements for the Los Alamos and boeing free-electron laser experiments

Abstract: Optical-transition radiation (OTR) measurements of the electron-beam emittance have been performed at a location just before the wiggler in the Los Alamos free electron laser (FEL) experiment. Beam profiles and beam divergence patterns from a single macropulse were recorded simultaneously using two intensified charge-injection device (CID) television cameras and an optical beam splitter. Both single-foil OTR and two-foil OTR interference experiments were performed. Preliminary results are compared to a reference variable quadrupole, single-screen technique. New aspects of using OTR properties for pointing the e-beam on the FEL oscillator axis, as well as measuring e-beam emittance are addressed.