Abstract: This application relates to the production, storage, and controlled release of hydrogen for use in the hydrogen economy. More specifically, it relates to a novel electrolysis system design that utilizes electrolysis of ionized vapors and gasses to produce and store hydrogen in a hydrogen host material and the capability to reverse the electrolysis potential to provide safe, controlled hydrogen release.

Abstract: The present invention provides an acoustic particle alarm comprising a particle sensor for indicating the concentration of particles exceeding a specified size and specified concentration, for particles entrained in a fluid flow impinging on a front face of the sensor, and a nozzle for directing the fluid flow such that the particles impact the sensor in a direction substantially normal to the front face of the sensor. Each particle impacting the front face of the sensor causes a response in an output of the sensor with amplitude that is monotonic in the momentum of the impinging particle.

Abstract: The present invention provides an acoustic particle alarm comprising a particle sensor for indicating the concentration of particles exceeding a specified size and specified concentration, for particles entrained in a fluid flow impinging on a front face of the sensor, and a nozzle for directing the fluid flow such that the particles impact the sensor in a direction substantially normal to the front face of the sensor. Each particle impacting the front face of the sensor causes a response in an output of the sensor with amplitude that is monotonic in the momentum of the impinging particle.

Abstract: A sonar system that includes a new comb-like waveform constructed by modulating the tines of a comb spectrum according to a set of Hermite functions defining a Hermite Function Space (HFS), and a processing method that reduces the sidelobes of the ambiguity function associated with the normally-processed HFS comb waveform. Noise-limited performance remains high, because the waveform is designed to be power-efficient; range ambiguity is superior to the highly-rated sinusoidal frequency-modulation (SFM) waveform; and reverberation-limited performance is equal to or better than that offered by any other waveform designed for this purpose. The full Doppler sensitivity normally associated with pulsed CW can be realized by the application to HFS signals of the constrained, regularized deconvolution method of this invention.

Abstract: A transducer assembly comprising: a diaphragm; at least one transducer elnt bonded by its head to the diaphragm; a pressure-resistant means, for supporting the transducer assembly; an acoustic isolator mounted about the transducer element and located between the diaphragm and the pressure-resistant means; the material of the acoustic isolator being elastically linear and equal in thickness to one-quarter wavelength of the corresponding operating frequency of the transducer element.

Abstract: An apparatus and method of improving the resolution of a linear FM signal s(t)=a(t)cos .phi.(t) where .phi.(t)=2.pi.(s.sub.o t+.alpha.t.sup.2) is provided by a modified computation of the Wigner-Ville Distribution. An analytical signal ##EQU1## is translated or calculated from the received linear FM signal r(t) so that a Wigner-Ville Kernel sequence ##EQU2## is formulated. An analysis of the frequency of the kernel sequence follows in accordance with a high resolution estimation technique that may include a kind of a least squares approximation fit or an eigenvector spectral estimator such as MUSIC OR ESPRIT to provide an improved time/frequency representation having a resolution of about an order of magnitude better as compared to a conventional discrete Fourier transform frequency analyze of the kernel sequence.

Abstract: Improved dynamic range resolution or accuracy analog to digital conversion ses linear prediction. An open loop or feed-forward architecture passes an analog signal to a coarse or orthodox analog-to-digital converter that provides digital signals representing a most significant part of the output signal and offers them as inputs to a digital linear predictor whose digital output signal is reconverted to analog form and fed to an analog adder. An analog delay device may be used to receive the next analog sample and, after the proper delay (if needed), feed it to the adder where the difference between the analog predicted value and the analog signal is determined and passed to a subsequent coarse or orthodox analog to digital converter. A closed loop or feedback configuration receives the analog input signal data as well as a feedback predicted value in analog form and passes the difference to a coarse or orthodox analog to digital converter.

Abstract: A method and the resulting article for providing a nearly zero temperature coefficient pressure transducer preferably comprising a cylindrical capacitor whose capacitance is a function of both externally applied pressure and, undesirably, of temperature. The variation of capacitance with temperature may be greatly minimized by selectively choosing a transducer material characterized by particular parameter constants such that the temperature coefficient of Young's modulus (.alpha..sub.E) is equal in magnitude but opposite in sign to the temperature coefficient of linear expansion (.alpha..sub.l). Moreover, the thermal variation of capacitance can be further minimized by selectively choosing a transducer material whose temperature coefficient of linear expansion and of Young's modulus are nearly zero. Fabricating a capacitance pressure transducer from materials characterized by .alpha..sub.E and .alpha..sub.

Abstract: An improved imaging system has applications to synthetic aperture radar, inverse synthetic aperture radar, delay-doppler radar, positron-emission topography sonar, radiometry and other applications having a target image provided by a series of data parameterized by a variable such as .theta.. A receiver structure includes a bandpass matched-filter, square law envelope-detector, specialized processing and convolving to produce the improved images irrespective that the radar signals have practical side lobe structures and other features. Despite the demands of specialized processing the architecture of the algorithm permits real-time implementations.

Abstract: A number of high frequency signal sources such as a number of receiving annas have their information content extracted by an optoelectronic synchronous sampling system. A laser provides pulses of proper frequency and duration and feeds them to a fiberoptic bundle. In one embodiment the fibers are lengthened to be simultaneously actuated. Otherwise, each of the fibers in the bundle has a different length so that light emanating from their distal ends appears as a delayed series of actuating light pulses. Phase shifters, pressure or electric field effects, can effect delay and consequent beamforming. Optoelectronic switches are disposed adjacent the distal ends so that the delayed series of actuating pulses actuates the switches in a synchronous sequence to synchronously sample the high frequency signals received by each of the antennas. Interconnected analog-to-digtal and processing circuitry conditions the synchronously received samples for further use.

Abstract: An apparatus multiplies two sequences of digital numbers a.sub.i and b.su, which may represent signal pulses of various amplitudes. A first plurality of t read-only memories (ROMs), have a common input adapted to receive the sequence of numbers a.sub.i, each ROM coding the numbers a.sub.i into a.sub.j,i =a.sub.j modulo m.sub.i, 0.ltoreq.a.sub.j,i .ltoreq.m.sub.i -1. A first plurality of t means, extend the digital signal with zero values, the number of zeroes being determined by the length N of the sequences being convolved. A first plurality of t D/A converters, convert the digital quantity received from the extender into its corresponding analog value.Similar ROMs, extending means, and D/A converters process the sequence numbers b.sub.i.A plurality of t means convolve two input analog signals, one from each of the first and second D/A converters, the output of each convolving means being an analog signal, approximately equal to the convolution (a.sub.j,i) * (b.sub.j,i) modulo m.sub.i.

Abstract: A transform system provides a real-time implementation of the discrete Foer transform (DFT) of length N, the system being useful in sonar and radar signal processing. The input signal g.sub.n, 0.ltoreq.n.ltoreq.N-1, comprises a discrete signal, generally complex, of N samples.The system comprises an input for receiving the input signal g.sub.n and convolving in a first, input, convolver with a signal represented by the function e.sup.i.pi.n.spsp.2.sup./N , to result in a first modified signal at the output of the first convolver. Means are provided for generating the signal e.sup.-i.pi.n.spsp.2.sup./N. A multiplier receives the first modified signal and the signal e.sup.-i.pi.n.spsp.2.sup./N and multiplies these two signals its output being a second modified signal.A second, output, convolver, whose input is connected to the output of the multiplier, convolves the output signal from the multiplier with a signal represented by the function e.sup.i.pi.n.spsp.2.sup.

Abstract: A sampled speech compression and expansion system, for two-dimensional prssing of speech or other type of audio signal, comprises transmit/encode apparatus and receive/decode apparatus.The transmit/encode apparatus comprises a low-pass filter, adapted to receive an input signal, for passing through low-frequency analog signals. A converter is connected to the low-pass filter for converting the analog signal into a digital signal. A buffer memory, whose input is connected to the converting means, stores the digitized signals.A correlator, having inputs from the A/D converter and the buffer memory, correlates the digital signal received directly from the converter with a delayed signal from the buffer memory. An "interval-select" circuit, whose input is connected to the output of the correlator, uses the autocorrelation value as a basis for comparison with subsequent peaks in the correlation value which are greater than a specified fraction of the autocorrelation value.

Abstract: A charge-coupled device (CCD) analog and digital correlator comprises identical modules, each of which is a simple analog CCD correlator with digital input and output. Circuits are included:(1) for injecting charges proportional to the voltage sequences s(n) and r(n), where s(n) refers to the input signal, and r(n) relates to a reference signal, against which the input signal is correlated;(2) for non-destructively sensing and tapping each sample s(n) and r(n);(3) for forming the summation s(n)+r(n);(4) and finally for squaring s(n), r(n), and [s(n)+r(n)] in simple, floating gate MOSFET amplifiers. The amplifiers operate in their saturation region, and have outputs proportional to s.sup.2 (n), r.sup.2 (n), and [s(n)+r(n)].sup.2, which are then fed into a differential amplifier to produce s(n)r(n).

Abstract: An image-compression system, wherein the image consists of a planar array of data points having various brightness levels, comprises a transmitter and a receiver. The transmitter comprises an analog-digital converter, for converting input analog data into digital data. The cosine transform is taken of the incoming digital data to transform the data representing various brightness levels into the frequency domain. The various frequency data points are differentially pulse code modulated, thereby removing line-to-line redundancy, the output data being in parallel form. Timing circuitry is provided for controlling the timing of the various circuits. Circuitry is provided in a receiver for the modulating or decoding of the output signal of the transmitter.

Abstract: A permutation memory comprises an input control means for decoding, having plurality L of inputs for an L-bit binary number, and a plurality 2.sup.L of outputs. Means are connected to the decoding means, for initiating the read-in of the L-bit number. Means are provided for applying an input signal. A first plurality of 2.sup.L of normally open switching means are connected to the 2.sup.L outputs of the decoding means and to the signal applying means. A plurality of 2.sup.L of means are connected to the switching means, for storing a charge when a specific switching means, connected to a corresponding charge storing means, is in a closed condition. A second plurality 2.sup.L of switching means are connected to the first plurality of switching means and to the charge storing means. An output control means, connected to the second plurality of switching means, reads out the states of the 2.sup.L charge-storing means, as to the amount of charge in each.

Abstract: An automatic frequency-hop controller for a surface acoustic wave (SAW) shesizer is used with a means for generating two chirp signals, one having a delay with respect to the other. It comprises a SAW device, adapted to receive the chirp signals. The SAW device comprises a substrate and a pair of sets of interdigitated electrodes, disposed on the surface of the substrate, one set at each end, the electrodes receiving the electrical chirp signals or corresponding impulse signals. Another set of interdigitated electrodes, which are output electrodes, are also disposed on the surface of the substrate, the electrodes of all sets being parallel. The output set of electrodes are so disposed as to receive the acoustic waves generated by the pair of sets of electrodes, and transduce them back to electrical signals.

Abstract: A frequency synthesizer, for use with a means for generating two sequences of electrical pulses, one sequence having a delay with respect to the other, comprises a surface acoustic wave (SAW) device, adapted to receive one of the sequences of electrical pulses from the generating means. The SAW device comprises a substrate, on the surface of which is disposed a first set of interdigitated electrodes. The electrodes receive the electrical pulses and tranduce them to acoustic waves, which traverse the surface of the substrate. The lengths of the electrodes are configured as a function of m, where m is defined by the relation m = R.sup.n mod P, where P is a prime number, R is a primitive root of P, and 1.ltoreq.n.ltoreq.P-1. A second set of interdigitated electrodes, approximately N-1 in number, is also disposed on the surface of the substrate, the electrodes of the first and second sets being parallel.

Abstract: A carrier-compatible device for computing the discrete Fourier transform of an input signal, using the chirp-Z transform (CZT) algorithm, comprising means for connecting to a real and imaginary part of an input signal g.sub.k. A pulse generator generates a sequence of very short pulses. A surface acoustic wave (SAW) chirp generator, whose input is connected to the output of the pulse generator, generates cosine chirp signals and sine chirp signals. Four input mixers have as their two inputs a real or imaginary part of the signal g.sub.k and a sine or cosine chirp signal from the SAW chirp generator. First and second summers have as their two inputs the outputs from two of the input mixers. A SAW chirp filter, whose two inputs are the outputs of the summers, filters out the higher components from the input signal and passes the lower components. Third and fourth summers are connected to the SAW chirp filter, whose two inputs are components from the SAW chirp filter.

Abstract: An acoustic communication method and system are disclosed for transmitting information through a well-bore drill string by using the acoustic noise inherently generated in the drill string by drilling operations as a "carrier" propagated therealong to be modulated by the information to be transmitted. In the drilling of wells, the action of the drill tool on the bottom of the bore hole creates acoustic noise within the drill string. Other suitable sources of "noise" are often present during "drilling operations", as broadly defined, even while bore drilling, as such, is suspended. This noise usually consists both of wide-band continuous acoustic energy and of narrow spectral lines of acoustic energy and is usually present in a variety of acoustic modes such as longitudinal and torsional acoustic waves. The detailed characteristic of this acoustic noise depends on the type of drill tool used, the drilling speed and the type of formation being drilled.