Moreover, since the resulting interference pattern also depends on the waves' frequency, the same array can concentrate SAWs in different ways at different frequencies, working the liquid sample in different ways.

ECONOMIST: Acoustic microfluidics

Popular at first as a working-class liquid lunch, the style took on the name of its barrel-schlepping fans: porter.

WSJ: Porters Get Fresh | Half Full

It works for solid waste collection, and it is working in a limited capacity with liquid waste collection.

NPR: Space Toilet Awaits Repair Mission

Their working model is a shoebox-sized package of electronics and liquid-filled tubes, with a silicon chip at its core.

ECONOMIST: Nanopores may lead the way to a new generation of sequencing

They are working with the Farmwatch scheme in the Test Valley to introduce a liquid substance which can be added to fuel to "chemically tag" it.

BBC: Heating oil 'tagged' to tackle rural theft in Hampshire

It first started working with Virent to produce hydrogen, but later shelved that effort to develop liquid fuels.

FORBES: Shell Biofuel Baby Grows Up A Little

The liquid-oxygen cylinder at the foot of the neatly made bed was filled and working properly.

NEWYORKER: Letting Go