Astronauts sealed in a spacecraft or space station need a continuous supply of oxygen. When they inhale, the oxygen in the air is absorbed by the blood and used by the body. When they exhale, nitrogen, water vapor, and carbon dioxide (CO2) are...

A service module is a spacecraft compartment containing a variety of support systems used for spacecraft operations, but not any habitable area. Service modules are jettisoned when they are no longer needed, for example just before atmospheric re-entry....

How do we improve the quality of care provided to ESRD beneficiaries? Perhaps not a question that we ask directly everyday, but a question that is the foundation of everything we do. One of the answers is through education and a better understanding...

Networking professionals have long recognized that putting a firewall at the LAN-WAN demarc is far from a complete security solution. Many experts have called for stronger internal security in the form of "departmental firewalling," (see BCR, June 2002, p. 12), which in turn...