E-mails circulate through a network of servers hosted by infrastructure firms all across the world.

FORBES: How Spam Was Solved

In 2003, Stanford University spin-out company Cooligy showed off its Active Micro-Channel Cooling (AMC) technology which allowed fluids to circulate through hundreds of tiny channels on the upper surface of a chip.

BBC: IBM aims to cool chips with water

The latest speculation to circulate through the European market is that German state bank WestLB, which is already facing difficulties in the wake of a trading scandal, is also in serious trouble because of its exposure to America's subprime mortgage market.

FORBES: Magazine Article

Since 2007, the foreclosure crisis, which has claimed nearly four million homes, has played out very differently across the U.S. After the robo-signing scandal of late 2010, lenders, flush with defaulted mortgage notes, delayed their processing of foreclosures, most notably in judicial states, where filings circulate through a court system.

FORBES: The Foreclosure Crisis Isn't Over Just Yet

In normal times, the ECB had interacted overwhelmingly with large banks, who would allow the liquidity to circulate freely through the system.

WSJ: ECB Chief Says Bank Helped Avert Disaster

The tsunami destroyed the diesel generators that provide power to drive the pumps that circulate the water coolant through the reactor that removes decay heat.

FORBES: Explainer: What Caused The Incident At Fukushima-Daiichi

CDFIs also credit their success with an ethos of collaboration and a constantly evolving set of best practices that circulate among member institutions through platforms like the Opportunity Finance Network.

FORBES: Lending For The Greater Good

If hydrates remain a problem, the smaller size will be easier for BP to circulate antifreeze-like methanol through the system, keeping the hydrates from forming.

FORBES: With 'Life On Line,' BP Plans Top Hat, Junk Shot To Stop Oil Leak

Japanese broadcaster NHK said Tepco was now studying a plan to circulate water from the basement through a decontamination filter and back into the reactor.

BBC: Japan nuclear: Tepco halts Fukushima cooling plan