Abstract: A design for a fast absorption optical tomography instrument is disclosed. The subject invention is capable of generating 100 projections of 100 elements each in less than 200 ns. It comprises and optical pulse generator, a tomography ring with temporally multiplexed fiber-optic fan-beam sources and fast detectors, and data acquisition electronics. A single short pulse (<10 ns) of radiation tuned to an absorption transition of the chemical species of interest produces a cross sectional image of concentration. Supplying two such pulses to the instrument can yield simultaneous quantitative images of temperature and absolute concentration in fields with temperature inhomogeneities. Additional pulses lead to concentration images of additional species.

Abstract: The present system and method employs Differential Absorption Lidar (DIAL) system and method to measure gas concentration within a plume, for example, ozone density with a rocket exhaust plume when large quantities of chlorine and alumina particles are injected directly into the stratosphere by the current fleet of launch vehicles, the system generate on-resonance and off-resonance pulses prior to plume formation for measuring beyond-plume ambient return and on-resonance and off-resonance pulse during plume formation for measuring beyond-plume returns which are normalized to the ambient returns and then ratioed to indicate the absorption effect within-plume to indicate changes in gas concentrations, being well suited for analysis of environmental affect of the exhaust plumes upon the atmosphere, and particularly, for remote sensing of ozone density within the plume of Titan IV launch vehicles, but can be extended to measure other gas concentration from other types of exhaust plumes.

Abstract: A fiber optic chemical dosimeter system detects the presence of hydrazine fuels and nitrogen tetroxide and nitrogen dioxide gases that are used at rocket launch sites using colorimetric sensors that react selectively with the gases and then absorb laser light communicating through a fiber optic network having a conventional diode laser source transmitting interrogation pulses to a plurality of distributed sensors covering a wide area launch site, the sensor being reactive cladding or distal end types both providing optical reflective returns well suited for reflective near infra-red and visible-red laser interrogation by an optical time domain reflectometry monitor which compares the interrogated laser pulses with sensor returns to determine the extent and location of gas cloud exposures over the distributed wide area.

Abstract: A lidar sensing apparatus having a laser generating alternating pulses at two respective wavelengths, 372 nm and 374 nm, an optical beam transmitter, a receiver telescope for collecting backscattered returns, a band pass optical filter for isolating the returns at 372 nm and 374 nm wavelengths, a photodetector for converting the returns into electronic counts and a data processor for relating the electronic counts into temperature, is used for mesospheric temperature sensing of the iron layer in the 80 to 100 Km altitude regions by collecting fluorescence returns which are related to temperature using a Fe Boltzmann technique. The apparatus also captures backscattered returns from the middle atmosphere between 30 and 80 km for temperature sensing using the Rayleigh technique, providing a complete temperature profile from 30 to 100 km altitudes.

Abstract: A stabilized atomic clock system uses a stabilized 780.2 nm pump laser for exciting rubidium-85 atoms fluorescing to optically pump rubidium-87 atoms both contained in a gas cell enclosed in a resonant microwave cavity for broadcasting a 6834.7 MHz microwave signal matched to Rb87 hyperfine ground states which are insensitive to pump laser wavelength fluctuations of the pump laser providing the fluorescence optical pumping of the Rb87 atoms to create a population imbalance sensed by a stabilized 794.7 nm probe laser transmitting a probe beam through the cell to a probe laser photodetector generating a probe laser signal used to stabilize the microwave signal to the atomic system and used to generate a constant frequency tick rate signal that is consequently insensitive to pump laser frequency drift due to reduced light shift coefficient.

Abstract: Thin films of aluminum nitride are deposited at 350 K on silicon, GaAs, fused quartz, and KBr substrates using gas-phase 193 nm excimer laser photolysis of trimethylamine alane and ammonia precursors without a thermally induced or a spontaneous reaction between them, resulting in AlN thin films that are amorphous, smooth and featureless having a band gap of 5.8 eV, a refractive index of 2.0, a breakdown electric field breakdown of 10.sup.8 V/m, a low-frequency dielectric constant of 6.0-6.9, high-frequency dielectric constant of 3.9-4.0, well suited for many thin film applications.

Abstract: Piezoelectric actuators bonded on S-shaped brackets extend between a support and a payload. The brackets can be used for vibration isolation by attenuating resonant vibrations under computer dynamic control relying on predetermined dynamic resonant characteristics and H-Infinity control methods. The brackets can also be used for platform directional pointing under computer control.

Abstract: An all reflective telescope system generally includes two spherical mirrors, one mild aspheric mirror and one aspheric mirror all centered about a common telescope axis and imaging on a focal surface for easy manufacture, very long focal length, wide field of view, high resolution, compact volume and low weight particularly well suited for space observations, and in a detailed form includes a sectional concave hyberboloidal primary mirror, a circular mild convex ellipsoidal secondary mirror, a sectional concave spherical tertiary mirror and a sectional convex spherical quaternary mirror for focusing an extended distant object onto a concave cylindrical focal surface having a linear array of charge coupled detectors for high resolution imagery, the telescope having high performance operation near diffraction limits and operating at detector resolution limits.

Abstract: A fiber optical chemical detection system detects the presence of hydrazine fuels and nitrogen tetroxide and nitrogen dioxide gases that are used at rocket launch sites using reversible colorimetric sensors that selectively form chemically reversible, intermolecular charge transfer-complexes with the gases that then absorb laser light communicating through a fiber optic network having a conventional diode laser source transmitting interrogation pulses to a plurality of distributed sensors covering a wide area launch site, the sensor being reactive cladding or distal end types both providing optical reflective returns well suited for reflective near infra-red and visible-red laser interrogation by an optical time domain reflectometry monitor which compares the interrogated laser pulses with sensor returns to determine the contemporaneous extent and location of gas cloud concentration over the distributed wide area.

Abstract: A fiber optic chemical dosimeter system detects the presence of hydrazine fuels and nitrogen tetroxide and nitrogen dioxide gases that are used at rocket launch sites using colorimetric sensors that react selectively with the gases and then absorb laser light communicating through a fiber optic network having a conventional diode laser source transmitting interrogation pulses to a plurality of distributed sensors covering a wide area launch site, the sensor being reactive cladding or distal end types both providing optical reflective returns well suited for reflective near infra-red and visible-red laser interrogation by an optical time domain reflectometry monitor which compares the interrogated laser pulses with sensor returns to determine the extent and location of gas cloud exposures over the distributed wide area.

Abstract: A hydrogen out venting window is disposed on or in a hermetically sealed electronic package lid, the window including a catalyst which dissociates internally trapped molecular hydrogen at an interior surface of the catalyst into atomic hydrogen and which recombines the atomic hydrogen back into molecular hydrogen at an exterior surface of the catalyst with the atomic hydrogen diffusing from the interior surface to the exterior surface to vent out the molecular hydrogen from the interior of the package to the exterior of the package, the window taking various forms including a catalyst sandwich with the package lid disposed between an interior catalysis plate and an exterior catalysis plate, a plate window with a catalysis covering plate disposed over a hole in the package lid, a plug window having a catalysis plug disposed in a hole in the package lid, or a lid window where the package lid is the catalyst, the catalyst being a suitable transition metal such as palladium or platinum, or alloy, disposed on or i

Abstract: A Concentric MESFET (CMESFET) is a small-signal traveling-wave transistor having a grounded source electrode which concentrically surrounds and shields the gate and drain electrodes from electromagnetic fields generated by other nearby circuit elements. S-parameters for the transistor are computed to obtain gain curves for design configurations. For a gate length of 2 um, maximum gain occurs with a gate width of 3.0 mm. The CMESFET has calculated bandwidth of 17 GHz for a 2 um gate length and a gate width of 300 m. Coupling capacitance between device electrodes and a nearby transmission line are calculated and used to verify improved source electrode shielding isolation of the device from interference and crosstalk originating in surrounding circuits.

Abstract: A gate-all-around (GAA) metal-oxide-semiconductor field-effect transistor (MOSFET) includes a source, channel and drain surrounded by a top gate and a buried bottom gate, the latter of which also has application for other buried structures and is formed on a bottom gate dielectric which was formed on source, channel and drain semiconductor layer. After forming a planar bottom insulator layer on the bottom gate and bottom gate dielectric, the device is flip-bonded to an oxide layer of a bulk silicon wafer, thereby encapsulating the buried bottom gate electrode in insulating oxide. The semiconductor layer forms the source, drain and channel in a mesa structure on which is deposed a top gate dielectric, a top gate, and top gate insulator as well as four conductors for connecting to the source, drain, top gate and bottom gate.

Abstract: A peak power tracker apparatus is used for controlling the negative impedance of converter for transferring maximum power from a solar array source to a battery and load typically used in space vehicles, by capacitive differentiation sensing the solar array source voltage for sensing the peak power point at which the source voltage first begins to become unstable and collapses, and then providing a step down control signal which controls a current mode pulse width modulator to control the converter to vary the negative impedance into the solar array then reserving back to a stable point at which the tracker then provide a linear ramp signal to the modulator to control the converter to drive the source voltage again to the peak power point, so as to alternate the feedback loop and source voltage between a stable point and the peak power point so as to transfer maximum power while preventing the source voltage to pass through an unstable point for discontinuous but stable operation at peak power transfer which

Abstract: An improved tangential linear flexure bearing for reciprocating machines is disclosed having improved reliability for long life, the flexure bearing being an integrated device comprising a translating cut diaphragm with circumferential tangent cantilever flexure blades secured between rim and hub spacers, the improvement being within the flexure blades having symmetrical opposing end angles and ends equally displaced from radial lines extending from the center of the diaphragm, and having grain orientation extending along the length of the flexure blades both features providing improved radial stiffness, low axial stiffness, reduced flexure stresses and increased fatigue strength for improve reliability.

Abstract: A hydrogen out venting window is disposed on or in a hermetically sealed electronic package lid, the window including a catalyst which dissociates internally trapped molecular hydrogen at an interior surface of the catalyst into atomic hydrogen and which recombines the atomic hydrogen back into molecular hydrogen at an exterior surface of the catalyst with the atomic hydrogen diffusing from the interior surface to the exterior surface to vent out the molecular hydrogen from the interior of the package to the exterior of the package, the window taking various forms including a catalyst sandwich with the package lid disposed between an interior catalysis plate and an exterior catalysis plate, a plate window with a catalysis covering plate disposed over a hole in the package lid, a plug window having a catalysis plug disposed in a hole in the package lid, or a lid window where the package lid is the catalyst, the catalyst being a suitable transition metal such as pallidium or platinum, or alloy, disposed on or i

Abstract: An untrasonic technique is presented which permits accurate measurement of the Poisson's ratio for a specimen which exists as a thin (<10 mil) layer. This technique measures resonance and should prove especially useful in situations where a bulk specimen is either not readily available or would not properly reflect the properties of the material when configured as a thin layer. A detailed discussion of the theory underlying the technique is included. The technique is then used to determine the values of Poisson's ratio of three thin specimen materials. These values were then contrasted to those of the bulk specimens obtained in a more conventional manner. The technique as presented could be extended for a number of applications, including the cure monitoring of adhesives.

Abstract: A special purpose processor and method of computation for performing an N-length real-number discrete cosine transform (DCT). The algorithm is called the split-radix discrete cosine transform because an Nth order DCT consists of an (N/2)th order DCT and two (N/4)th order inverse DCT (IDCT), where N is an integer power of 2 and larger than 4. In the embodiments of the invention, signal flow-graphs for both the forward and inverse scaled DCT have been implemented based on fused multiply and add operations in pipeline architectures. In the two-dimensional cases, over 20% arithmetic operations are saved compared to other known fast two-dimensional DCT algorithms. In addition, the split-radix DCT method offers flexibility of processing different input sizes under software control.

Abstract: Frequency domain ECG signal processing systems and methods plot spectral maps and compute statistical parameters from surface electrocardiographic signals, which plots and parameters reveal abnormalities of electrical conduction within the hearts of patients at risk of ventricular tachycardia. Fourier analysis of short overlapping time segments of QRS ECG signal are used to create three dimensional spectral maps disclosing changes in the frequency spectral content of the ECG signal over the whole QRS region. Correlations and statistical evaluations of the spectral content between QRS time segment pairs quantify the spectral turbulence of the ECG and distinguish those at risk from ventricular tachyarrhythmias.