Image
from article Saffron
Saffron (Crocus sativus) with its three red-colored stigmas. These distinctive stigmas (“saffron threads”) are dried to obtain the spice. (Photo copyright © Joanna Baron, used with permission)
Search Results
Search Results
Refine this search
Search result paging links
19,855 results
Image
from article Messier Catalog
Image
from article Messier Catalog
Image
from article Red Sea
Division of the Red Sea into regions representing different stages in the formation of an ocean basin. (After F. Martinez and J. R. Cochran, Structure and tectonics of the northern Red Sea: Catching a continental margin between rifting and drifting,…
Image
from article Precipitation (chemistry)
Precipitation of calcium fluoride. (Copyright © McGraw-Hill Education/Stephen Frisch)
Image
from article Active sound control
Results of a computer simulation of the sound field produced by two sources of spherical sound waves in air that have identical source strengths and are separated by a distance of 10 m. The sources are out of phase and radiate sound at a frequency…
Image
from article Active sound control
Feed-forward active noise control system. Elements of the system below the broken line are entirely digital, the filter H operating on the input sequence x to produce the output sequence y. The characteristics of the filter are designed by using the…
Image
from article Active sound control
Active control system for the suppression of propeller-induced aircraft cabin noise. The digital filters H1 and H2 are designed to minimize the sum of the squared error signals e1–e4.
Image
from article Active sound control
Distribution of sound pressure level (in decibels on an arbitrary scale) at head height in a 48-seat propeller aircraft (a) before and (b) after the use of a multichannel active noise control system consisting of 16 loudspeakers and 32 microphones.…
Image
from article Active sound control
Multichannel feed forward active control system for suppressing noise from multiple primary sources.
