Award Data

Power electronic converters are essential in every MDA vehicle, with use in critical systems ranging from electric power management applications, to power distribution, to on-board servo motor/actuator drivers. Advancing state-of-the-art power electronics technologies through the use of SiC semiconductors will produce significant savings across the board in almost all areas of MDA power management ...

THE SODIUM HEAT ENGINE (SHE) IS AN EFFICIENT DEVICE FOR THE DIRECT CONVERSION OF THERMAL ENERGY TO ELECTRICAL ENERGY. THE DEVICE HAS HIGH SPECIFIC POWER BOTH ON A VOLUME AND WEIGHT BASIS, HIGH CONVERSION EFFICIENCY WHICH IS INDEPENDENT OF SIZE, AND NO MOVING PARTS WHICH IMPLIES POTENTIALLY HIGH RELIABILITY. THESE ATTRIBUTES MAKE THE SHE AN ATTRACTIVE DEVICE FOR SDI APPLICATIONS. ALTHOUGH THE PRINC ...

PRESHOCKED PRECONDITIONING OF TUFF MAY OCCUR IN TWO MANNERS AT THE NEVADA TEST SITE. FIRST, THE MATERIAL IS "PRESHOCKED" IN A LINEOF-SIGHT TYPE UNDERGROUND NUCLEAR TEST BY THE FIRST WAVE PASSAGE. THE SECOND MANNER MAY OCCUR AS A RESULT OF AREAL SPACE LIMITATIONS WHEN A SECOND EVENT IS SITED WITHIN A REGION OF PRESHOCKED MATERIAL. UNDER CERTAIN LOAD-UNLOADED CONDITIONS THE MATERIAL STRENGTH MAY BE ...

SHEAR DISPLACEMENT ALONG ROCK MASS DISCONTINUITIES (JOINTS) UNDER SATURATED, UNDRAINED CONDITIONS IS ONE OF THE CRITICAL FAILURE MODES FOR A DYNAMICALLY LOADED DEEP BASE STRUCTURE. THE FAILURE MODE HAS NOT BEEN EXPERIMENTALLY SIMULATED FOR DEEP BASE CONDITIONS. THE COMBINED APPLICATION OF NORMAL AND SHEAR STRESSES AT DYNAMIC RATES, WITHOUT PORE PRESSURE DRAINAGE, IS LIKELY TO PRODUCE HIGH PORE PRE ...