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.

Pentafluorosulfanyl (SF5) Containing Energetic Salts

Abstract: New quaternary salts of pentafluorosulfanyl-substituted (SF5) N-methylimidazole (1), 4-amino-1,2,4-triazole (3) or pyridine (5) were prepared and characterized. Most of the salts exhibit good thermal stabilities and low melting points placing them in the ionic liquid class. Their densities range between 1.4 and 1.8 g/cm3. The standard enthalpies of formation for the new salts were calculated by the use of computationally feasible DFT(B3LYP) and MP2 methods in conjunction with an empirical approach based on densities of salts. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)

Security Analytics: Essential Data Analytics Knowledge for Cybersecurity Professionals and Students

Abstract: At the 2015 Workshop on Security and Privacy Analytics, there was a well-attended and vigorous debate on educating and training professionals and students in security analytics. This article extends this debate by laying out essential security analytics concepts for professionals and students, sharing educational experiences, and identifying gaps in the field.

Causal analytical wavelet transform

Abstract: The causal analytical wavelet transform employs exponentially decaying nonsinusoidal wideband transient bases of compact support. The basis set h ab ( t ) = h [( t - b )/ a ]√ a is called daughter wavelets, which are constructed from a causal analytical mother wavelet h ( t ) by means of the dilation parameter a and the translation parameter b . We show that a causal (i.e., zero valued before signal arrives) and analytical mother wavelet still guarantees completeness. This permits the selection of mother wavelets that better match causal analytical input signals. An optical architecture is described for real-time implementation.

The mean velocity profile of a smooth-flat-plate turbulent boundary layer at high Reynolds number

Abstract: Smooth flat-plate turbulent boundary layers (TBLs) have been studied for nearly a century. However, there is a relative dearth of measurements at Reynolds numbers typical of full-scale marine and aerospace transportation systems (Reθ = Ueθ/ν > 105, where Ue = free-stream speed, θ = TBL momentum thickness and ν = kinematic viscosity). This paper presents new experimental results for the TBL that forms on a smooth flat plate at nominal Reθ values of 0.5 × 105, 1.0 × 105 and 1.5 × 105. Nominal boundary layer thicknesses (δ) were 80–90mm, and Karman numbers (δ+) were 17000, 32000 and 47000, respectively. The experiments were conducted in the William B. Morgan Large Cavitation Channel on a polished (k+ 2δ. To within experimental uncertainty, the measured mean velocity profiles can be fit using traditional zero-pressure-gradient (ZPG) TBL asymptotics with some modifications for the mild favourable pressure gradient. The fitted profile pairs satisfy the von-Karman momentum integral equation to within 1%. However, the profiles reported here show distinct differences from equivalent ZPG profiles. The near-wall indicator function has more prominent extrema, the log-law constants differ slightly, and the profiles' wake component is less pronounced.