91色情片

A vacuum cleaner that can sift forensically interesting material from soil at
a crime scene has been developed at Michigan State University in East Lansing.
The Trace Evidence Concentrator, built by Jay Siegel and Alvin Smucker, sucks up
material and dumps it into a whirlpool created by water jets inside the device.
Particles such as clothing fibres and hairs drift to the top, where they are
separated out by a series of filters. Heavier material falls and is trapped by a
filter at the bottom. 鈥淭he old-fashioned way鈥攔ummaging through soil or
vacuumed material by hand with a magnifying glass鈥攖akes hours and isn鈥檛
efficient,鈥� says Siegel. 鈥淵ou can sort for days and never see what you
飞补苍迟.鈥�