Video Capture (IMAGE) NASA/Johnson Space Center Caption This video frame capture shows a pulse flow in the microgravity airplane. The frames should be read from the top down, and show the pulse front (seen as the leading edge of a 'lighter' region in the image) advancing from left to right. Pulse flows are desired in packed bed reactors because they enhance inter-phase contact -- thus making the process more efficient. Credit NASA Video Capture Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.