Abstract: A gas turbine engine is provided, having a turbomachine and a rotor assembly driven by the turbomachine and operable at a first blade passing frequency (f1) greater than or equal to 2,500 hertz and less than or equal to 5,000 hertz during a high power operating condition; a heat exchanger positioned within an annular duct and extending substantially continuously along the circumferential direction, wherein an effective transmission loss (ETL) for the heat exchanger positioned within the annular duct is between 5 decibels and 1 decibels for a high power operating condition, and wherein the heat exchanger comprises a heat transfer section defining an acoustic length (Li), and wherein an Operational Acoustic Reduction Ratio (OARR) is greater than or equal to 0.75 to achieve the ETL at the high power operating condition, the OARR equal to: sin ? ? ( 2 × ? × f 1 a 1 × L i ) 2 wherein a1 is equal to 13,200 inches per second during the high power operating condition.

Abstract: A method for the extraction of TNT from high explosves comprising the contacting the explosive with a supercritical fluid at a temperature above the meltng point of TNT and recovering the TNT.

Abstract: This invention is a dual shutoff key which is a single tool for shutting off both gas and water utilities. This capability is important in emergencies, such as approaching hurricanes or after an earthquake. The key consists of a main bar having a U-channel at one end for main water valve shutoff, and a skew slot for main gas valve shutoff. Hinged to the main bar is a lever bar which can swing out at right angles to the main bar to provide leverage when turning a normally tight or even corroded water valve. The main bar is long enough to reach down to below-ground water valves, and the lever bar is long enough to provide a torque of 150 foot-pounds. This enables persons with limited manual strength--such as children, the handicapped and the elderly--to shut off water.For gas shutoff the main bar provides sufficient leverage and the lever bar is placed in the folded position adjacent to the main bar. The lever bar is held in place by detents in the folded position.