Atmospheric turbulence conditions leading to focused and folded sonic boom wavefronts

Atmospheric turbulence conditions leading to focused and folded sonic boom wave fronts.

The propagation and subsequent distortion of sonic booms with rippled wave fronts are investigated theoretically using a nonlinear time-domain finite-difference scheme. This work seeks to validate the rippled wave front approach as a method for explaining the significant effects of turbulence on sonic booms [A. S. Pierce and D. J. Maglieri, J. Acoust. Soc. Am. 51, 702-721 (1971)]. A very simple...

Quadratic phase of tightly focused wavefronts

In an aplanatic optical system, where the entrance pupil is not located at the front focal plane, a corresponding quadratic phase is expected at the back focal plane. However, tightly focused optical fields evaluated by methods based on the traditional Richards-Wolf approach, lacks this quadratic phase. In the current work we calculate the focused field, for both high and medium numerical apert...

Indoor Sonic Boom Reproduction Using ANC

ABSTRACT The European programs for development of supersonic air-flights involve new studies on the human perception of sonic boom. Because this noise includes high-level components at very low-frequency, the usual psycho-acoustic tests with headphones are not relevant; instead, the original sound-field can be reproduced with many loudspeakers in a small room, but the loudspeakers must be contr...

Pathway Leading to Correctly Folded β-Tubulin

*Department of Biochemistry noff et al., 1989; Ostermann et al., 1989; Martin et al., New York University Medical Center 1991; Gething and Sambrook, 1992; Gao et al., 1992; New York, NY 10016 Horwich et al., 1993; Lewis et al., 1996). †Flanders Interuniversity Institute for Biotechnology It has not provedpossible to obtain exchange-compeUniversity of Ghent tent tubulin following denaturation of...

Automatic Differentiation for Optimum Design, Applied to Sonic Boom Reduction