The National Institute of Standards and Technology operates a cesium fountain primary frequency standard, NIST-F1, which has been contributing to International Atomic Time (TAI) since 1999. During the intervening 11 years, we have improved NIST-F1 so that the uncertainty is currently 16 0 3 10 , f f     dominated by uncertainty in the blackbody-radiationinduced frequency shift. In order to ...

The caffeine content of 10 energy drinks, 19 carbonated sodas, and 7 other beverages was determined. In addition, the variability of the caffeine content of Coca-Cola fountain soda was evaluated. Caffeine was isolated from the samples by liquid-liquid extraction and analyzed by gas chromatography with nitrogen-phosphorus detection. The caffeine concentration of the caffeinated energy drinks ran...