These compounds make teeth less sensitive and increase resistance to dental caries by filling in microscopic holes and repairing early cavities. When applied in a carbonate solution, the compounds form rapidly and then crystallize to apatite, the mineral in teeth. Automakers need new chemical measurement technologies and standards to design cars and trucks that will meet increasingly stringent federal Clean Air requirements and California emission standards. NIST is collaborating with the American Industry Government Emissions Research organization to help U.S. auto manufactuers develop and test low-emission vehicles. The effort will include development of new exhaust emissions analysis technologies and standards based on microsensor arrays, infrared light, and microwaves.
Optical tape is an emerging media for high-density storage of computer data.
NIST researchers are participating in the Optical Tape Study Group established by the Association for Information and Image Management International to help industry develop measurements, evaluation techniques, and specifications for long-term computer data storage with optical tape. The study group explores such issues as data integrity, metrology concerns, media and drive specifications, and possible future standards. Several key organizations from industry and government participate in the study group. NIST scientists have developed a practical wide-band acoustic emission sensor for detecting cracks in steel bridges, pressure vessels, and composite parts, such as those used in automobiles and aircraft. The new sensor features a significant increase in sensitivity that rivals the level found in narrow-band resonant sensors.