Abstract: Apparatus for generating signals to interfere with or jam signals detected as unfriendly in a given input frequency band comprises a spectrum analyzer circuit using surface acoustic wave (SAW) chirp filters to provide a transformation of input frequency signals to a series of time displaced signals in a linear frequency-to-time relationship. The analyzer circuit uses the SAW devices to perform multiply-convolve functions that separate the different frequency signals in time and the analyzer is repetitively triggered to perform a spectrum analysis. The time series signals are selectively applied to a frequency synthesizer having a time-to-frequency relationship that matches the analyzer characteristic so as to regenerate signals at the input frequencies. The synthesizer uses two matched chirp filters one activated by a fixed time signal and the other by the time series to generate swept frequencies that are mixed to provide the required frequency outputs.

Abstract: The invention involves a digital synthetic-focus, acoustic imaging system which is operative in real time and includes one or more electro-acoustic transducers arranged to receive broadband pulses from a pulse generator for excitation of acoustic pulses which are directed into the region under observation. Signals reflected from an object or discontinuity in the region are received by the same transducers, and after inverse filtering and nonlinear amplification are converted to digital signals. These digital signals are stored in separate high speed random access memory units for storage, but are subsequently time-equalized through use of a programmed focus memory unit prior to delivery to a digital adder and thence through a digital-to-analog converter for ultimate intensity modulation on a raster scanned display unit which provides the real time image.

Abstract: Thermosetting powder coating compositions comprising cellulose butyrate having a butyryl content of from about 35% to about 55% by weight, a hydroxyl content of from about 0.5% to about 3.0% by weight, and a viscosity of from about 0.05 to about 1.0 second are disclosed. The composition further comprises a crosslinking agent and a catalyst which allows the powder to flow out prior to fusion. Coatings formed by this composition have excellent physical properties and appearance.

Abstract: A thermosetting powder coating composition comprises a low molecular weight cellulose acetate butyrate as the major component, an aminoplast crosslinking agent, a latent acid crosslinking catalyst, and certain poly(alkylene glycols).

Abstract: A powder coating composition particularly useful in coating unprimed substrates which comprises a particulate form of a carboxylated polyolefin. The carboxylated polyolefin is prepared by reacting a polyolefin with an unsaturated dicarboxylic acid component. The carboxylated polyolefin has a saponification number of about 2 to about 12. The carboxylated polyolefin also has either a melt flow of from about 15 to about 175 g./10 minutes at 230.degree.C. or a melt index of 5 to 75 at 190.degree.C. The particulate form has a particle size of less than 20 mesh.