They were in the middle of a tight concentration of towers that obscured sight in every direction.

Finally, the central binaries are either disrupted or ejected, resulting in a tighter concentration at the core.

Previously, these globular clusters had been classified as being in old age because they had very tight concentrations of stars in their centers, another test of age used by astronomers.

But her hands pressed against the thing's skull, and her expression was one of tight concentration.

And why does he have his eyes closed in such tight concentration?

Round the central console four figures hunched in tight concentration trying to blot from their minds the terrifying shuddering of the ship and the fearful roar that echoed through it.

Mr. Guerrero represented the 14 families that formed the nation's oligarchy and other large landowners who thwarted efforts in the mid-1970's to break up the country's tight concentration of property owners.

The tight concentration of troops also offered an excellent target for the Texian artillery.

These three clusters are easily seen as tight concentrations of bright, massive stars in the NICMOS image.

Too much faith was placed in small ideas, like the four-note lullabylike pattern for the soloist (Christopher Finckel, playing with tight concentration) that reappeared so often in "Circadian Rhythms."