Abstract: A solid electrolytic type hygrometer is described, which operates with high reliability while providing rapid and sensitive response. A gold foil electrode (16) is wrapped about a hollow glass cylinder (18), a sheet (12) of hygroscopic-electrolytic material is wrapped about the foil, and a wire (14) is wound around the outside of the electrolytic sheet. Moisture passing between wire turns can be absorbed by the electrolytic material (12), and then dissociated by current passed by the electrodes (14, 16) through the electrolytic material. The cylinder has a slit (20) extending along its length, to allow resilient expansion to press the sheet of electrolytic material firmly against the electrodes. The wire turns lie against one another to cause rapid dissociation of moisture throughout the electrolytic material. Additional guard wires (42,44, FIG. 2) lie at opposite ends of the electrolytic sheet, and currents pass through them to avoid moisture buildup at the ends of the main wire coil.

Abstract: A remote television viewing system employing an eye tracker is disclosed, wherein a small region of the image appears in high resolution, and the remainder of the image appears in low resolution. The eye tracker monitors the position of the viewer's line of sight. The eye tracker position data is transmitted to the remote television camera and control. Both the remote camera and television display are adapted to have selectable high-resolution and low-resolution raster scan modes. The position data from the eye tracker is used to determine the point at which the high-resolution scan is to commence. The video data defining the observed image is encoded in a novel format, wherein in each data field, the data representing the position of the high-resolution region of predetermined size appears first, followed by the high-resolution zone video data and then the low-resolution region data.

Abstract: A stable density-stratification solar pond 10 for use in the collection and storage of solar thermal energy including a container 12 having a first section 14 characterized by an internal wall of a substantially cylindrical configuration and a second section 16 having an internal wall of a substantially truncated conical configuration surmounting the first section in coaxial alignment therewith, the second section of said container being characterized by a base of a diameter substantially equal to the diameter of the first section and a truncated apex defining a solar energy acceptance opening 20. A body 26 of immiscible liquids is disposed within the container and comprises a lower portion 28 substantially filling the first section of the container and an upper portion 30 substantially filling the second section of the container, said lower portion being an aqueous based liquid of a darker color than the upper portion and of a greater density.

Abstract: An arrangement for damping the resonance in a laser diode includes an additional layer (25) which together with the conventional laser diode form a structure (35) of a bipolar transistor. Therein, the additional layer serves as the collector, the cladding layer (12) next to it as the base, and the active region (11) and the other cladding layer (13) as the emitter. A capacitor (30) is connected across the base and the collector. It is chosen so that at any frequency above a certain selected frequency (f.sub.c) which is far below the resonance frequency (f.sub.res) the capacitor impedance is very low, effectively shorting the base to the collector.

Abstract: Crystals (51) of high morphological quality are grown by dissolution of a substance (28) to be grown into the crystal (51) in a suitable solvent (30) under high pressure, and by subsequent slow, time-controlled reduction of the pressure of the resulting solution (36). During the reduction of the pressure interchange of heat between the solution (36) and the environment is minimized by performing the pressure reduction either under isothermal or adiabatic conditions.

Abstract: High sulfur content carbonaceous material, such as coal is desulfurized by continuous fluidized suspension (20) in a reactor (18) with chlorine gas, inert dechlorinating gas and hydrogen gas. A source of chlorine gas (30), a source (32) of inert gas and a source (34) of hydrogen gas are connected to the bottom inlet (24) through a manifold (28) and a heater (26). A flow controller (42) operates servos (36, 38, 40) in a manner to continuously and sequentially suspend coal in the three gases. The sulfur content is reduced at least 50% by the treatment.

Abstract: Disclosed is a method and apparatus for a magnetic refrigeration system. A continuously reciprocating displacer houses at least a pair of paramagnetic substances each of which is alternately driven into and out of a magnetic field. Two separate bidirectional pumping systems flow helium gas through the displacer and through both paramagnetic substances to create heat exchange conditions at two separate temperature extremes.

Abstract: A system for remote absorption spectroscopy of trace species using a diode laser (14) tunable over a useful spectral region of 50 to 200 cm.sup.-1 by control of diode laser temperature over range from 15.degree. K. to 100.degree. K., and tunable over a smaller region of typically 0.1 to 10 cm.sup.-1 by control of the diode laser current over a range from 0 to 2 amps. Diode laser temperature and current set points are transmitted to the instrument in digital form and stored in memory (32) for retrieval under control of a microprocessor (28) during measurements. The laser diode current is determined by a digital-to-analog converter (62) through a field-effect transistor (Q.sub.1) for a high degree of ambient temperature stability, while the laser diode temperature is determined by set points entered into a digital-to-analog converter (64) under control of the microprocessor.

Abstract: A synthetic aperture radar (10) is employed for .DELTA.k measurement of ocean current from a spacecraft (11) without the need for a narrow beam and long observation times. The SAR signal is compressed (12) to provide image data for different sections of the chirp bandwidth, equivalent to frequencies f.sub.1 (t.sub.a,t), f.sub.2 (t.sub.a,t) . . . f.sub.n (t.sub.a,t), and a common area for the separate image fields is selected (14). The image for the selected area at each frequency is deconvolved (16) to obtain the image signals for the different frequencies (f.sub.1, f.sub.2 . . . f.sub.n) and the same area. A product of pairs of signals is formed (18, 20), Fourier transformed (22) and squared (24). The spectrum thus obtained from different areas for the same pair of frequencies f.sub.jk, f.sub.j+n,k are added (26) to provide an improved signal to noise ratio.

Abstract: A method and apparatus for testing the operation of a complex stabilization circuit in a closed-loop system (12, 38) is comprised of a programmed analog (60-72) or digital (80-86) computing system for implementing the transfer function of a load (12), thereby providing a predictable load. The digital computing system employs a table stored in a microprocessor (84) in which precomputed values of the load transfer function are stored for values of input signal from the stabilization circuit (38) over the range of interest. This technique may be used not only for isolating faults in the stabilization circuit (38), but also for analyzing a fault in a faulty load by so varying parameters of the computing system as to simulate operation of the actual load with the fault.

Abstract: A feed element-to-beam interconnection network is provided for an antenna that transmits and receives a large number of beams, such as 87 contiguous narrow beams that cover the United States. The network, which is connected to a layer of 134 feed elements that transmit and receive microwaves, consists of a pair of circuit boards (160c, 162c in FIG. 7) parallel to the feed element layer. One of the two boards has 87 dividers (e.g. 51td, FIG. 5) that each divide a signal to be transmitted into seven portions, and the other board has 134 combiners (e.g. 38tc) that each collect seven transmit signal portions and deliver the sum to one of the feed elements. A similar arrangement is used to handle received signals, with 134 receive signal dividers (e.g. 38rd) on the one board, and 87 receive signal combiners (e.g. 51rc) on the other board.

Abstract: An apparatus (21) and method is disclosed for keeping interior walls (28) of a reaction vessel (22) free of undesirable deposits of solid materials in gas-to-solid reactions. The apparatus (21) includes a movable cleaning head (36) which is configured to be substantially complementary to the interior contour of the walls (28) of the reaction vessel (22) and which is disposed in close proximity to the walls (28). The head (36) ejects a stream of gas with a relatively high velocity into a narrow space between the head (36) and the walls (28), and in accordance with Bernoulli's principle the head (36) is biased towards the walls (28) by the pressure prevailing in the reaction vessel (22). The gas ejected from the head (36) is of such composition that it does not participate significantly in the chemical reaction conducted in the reaction vessel (22).

Abstract: A coulometer for accurately measuring the state-of-charge of an open-cell battery utilizing an aqueous electrolyte. The coulometer includes a current meter (38) for measuring the battery charge/discharge current and a flow meter (42) for measuring the rate at which the battery produces gas during charge and discharge. Coupled to the flow meter is gas analyzer (54) which measures the oxygen fraction of the battery gas. The outputs of the current meter, flow meter and gas analyzer are coupled to a programmed microcomputer which includes a CPU (68) and program and data memories (74), (76). The microcomputer calculates that fraction of charge and discharge current consumed in the generation of gas so that the actual state-of-charge can be determined. The state-of-charge is then shown on a visual display (80).

Abstract: A microphone which is not subject to corrosion is provided by employing carbon granules to sense sound waves. The granules are packed into a ceramic tube and no diaphragm is used. A pair of electrodes are located in the tube adjacent the carbon granules and are coupled to a sensing circuit. Sound waves cause pressure changes on the carbon granules which results in a change in resistance in the electrical path between the electrodes. This change in resistance is detected by the sensing circuit. The microphone is suitable for use as a leak detection probe in recovery boilers, where it provides reliable operation without corrosion problems associated with conventional microphones.

Abstract: A wideband passive synthetic-aperture multichannel receiver (20) with an antenna (15) is mounted on a satellite 10 which travels in an orbit above the Earth passing over large bodies of water (12) e.g. the Atlantic Ocean. The antenna is scanned (16) to receive signals over a wide frequency band from each incremental surface area (pixel) of the water (P1, P2, etc.) which are related to the pixel's sea temperature. The received signals are fed to a plurality of channels (C1-C10) which are tuned to separate selected frequencies (f1-f10). Their outputs are fed to a processor (25) with a memory (30) for storage therein. As the antenna points to pixels (footprint FP 1-1, etc.) within a calibration area (A1) around a buoy (B1) of known coordinates, signals are likewise received and stored. From the buoy exactly measured sea temperature is received.

Abstract: Disclosed is an optical system used in a spacecraft to observe a remote surface and provide a spatial and spectral image of this surface. The optical system includes aspheric and spherical mirrors aligned to focus at a first focal plane an image of the surface, and a mirror at this first focal plane which reflects light back on to the spherical mirror. This spherical mirror collimates the light and directs it through a prism which disperses it. The dispersed light is then focused on an array of light responsive elements disposed at a second focal plane. The prism is designed such that it disperses light into components of different wavelengths, with the components of shorter wavelengths being dispersed more than the components of longer wavelengths to present at the second focal plane a distribution pattern in which preselected groupings of the components are dispersed over essentially equal spacing intervals.

Abstract: A local area network is provided for a plurality of autonomous computers (10) which operate at different rates and under different protocols coupled by network bus adapters (12) to a global bus (14). A host computer (HC) divides a message file to be transmitted into blocks, each with a header that includes a data type identifier and a trailer. The associated network bus adapter (NBA) then divides the data into packets, each with a header to which a transport header and trailer is added with frame type code which specifies one of three modes of addressing in the transmission of data, namely a physical address mode for computer to computer transmission using two bytes for source and destination addresses, a logical address mode and a data type mode. In the logical address mode, one of the two addressing bytes contains a logical channel number (LCN) established between the transmitting and one or more receiving computers.

Abstract: A portable laser system for remote detection of methane gas leaks and concentrations is disclosed. The system transmitter includes first and second lasers, tuned respectively to a wavelength coincident with a strong absorption line of methane and a reference wavelength which is weakly absorbed by methane gas. The lasers are aimed at a topographical target along a system axis and the beams successively interrupted by a chopper wheel.The system receiver includes a spherical mirror for collecting the reflected laser radiation and focusing the collected radiation through a narrowband optical filter onto an optial detector. The filter is tuned to the wavelength of the two lasers, and rejects background noise to substantially improve the signal-to-noise ratio of the detector. The output of the optical detector is processed by a lock-in detector synchronized to the chopper, and which measures the difference between the first wavelength signal and the reference wavelength signal.

Abstract: A technique for self-calibration and phasing of a lens-feed array antenna, while normal operation is stopped, utilizes reflected energy of a continuous and coherent wave broadcast by a transmitter (11) through a central feed (10) while a phase controller (21) advances the phase angles of reciprocal phase shifters (14) in radiation electronics (RE1-REN) of the array elements (1-N) at different rates to provide a distinct frequency modulation of electromagnetic wave energy returned by reflection in one mode (switch 19 closed) and leakage in another mode (switch 19 open) from the radiation electronics of each array element. The composite return signal received by a synchronous receiver (12) goes through a Fourier transform processing system (20) and produces a response function for each antenna element.

Abstract: A microprocessor system is provided with added memories (1-M) to expand its address spaces beyond its address word length capacity by using indirect addressing instructions of a type having a detectable operations code and dedicating designated address spaces of memory to each of the added memories, one space to a memory. By decoding each operations code of instructions read from main memory into a decoder (16) to identify indirect addressing instructions of the specified type, and then decoding the address that follows in a decoder (20) to determine which added memory is associated therewith, the associated added memory is selectively enabled through a unit (22) while the main memory is disabled to permit the instruction to be executed on the location to which the effective address of the indirect address instruction points, either before the indirect address is read from main memory or afterwards, depending on how the system is arranged by a switch (S.sub.1).