Now showing items 1-3 of 3
Active control of aircraft engine inlet noise using compact sound sources and distributed error sensors
(United States Patent and Trademark Office, 1994-10-11)
An active noise control system using a compact sound source is effective to reduce aircraft engine duct noise. The fan noise from a turbofan engine is controlled using an adaptive filtered-x LMS algorithm. Single multi ...
Fine powders of ketone-containing aromatic polymers and process of manufacture
(United States Patent and Trademark Office, 1994-10-18)
Fine particles of semi-crystalline ketone-containing aromatic polymers (PEEK, PEKK, etc.) are produced by controlling the rate and conditions of hydrolysis of an amorphous polyarylketimine intermediate. The choice of acid ...
Fused biconical taper fiber optic coupler station and fabrication techniques
(United States Patent and Trademark Office, 1994-08-16)
The fibers are bound together about 1 cm apart. An oxy-propane torch is used to heat the fibers so that they fuse together. At the same time, the two relatively movable translational stages to which the fibers are clamped ...