Abstract: A variable intensity LED illumination system is configured to provide a change in luminance versus input voltage that corresponds to a desired transfer function, such as the dimming characteristics of an incandescent lamp, which more closely resembles the response of the human eye. The system also advantageously provides overvoltage protection, increased brightness, energy efficiency, and significantly better longevity and ruggedness, compared to incandescent lamps.

Abstract: A method of identifying a human gesture using a machine includes providing a time sequence of data related to the human gesture; transforming the time sequence of data into waveforms; extracting features from the waveforms; and identifying the human gesture based on the extracted features.

Abstract: A method for improving the bit error rate in digital transmissions of sonobuoy sensor data from a sonobuoy to a receiver platform includes computing a send checksum on a frame of sonobuoy sensor data, copying the frame of data and checksum into a plurality of subframes, delaying one of the plurality of subframes for a predetermined period, multiplexing the delayed subframe with the plurality of subframes into a transmit frame; and transmitting the transmit frame. The invention is particularly suited to improving the reception of legacy sonobuoy receivers in littoral waters where radio frequency interference and signal propagation is a severe problem.

Abstract: An onboard system for a rotary wing aircraft detects a limit cycle oscillation in the tail mast and provides a timely indication of the limit cycle oscillation to an aircrew before serious damage to the airframe is likely to occur.

Abstract: The invention relates to an oleaginous mildew and corrosion-inhibiting composition, and the use of said composition to protect metal from corrosion and mildew. The composition comprises, in parts by weight, from about 20 to 60 parts of an oleaginous material such as a lubricating oil, 10 to 40 parts of organic solvent, 20 to 60 parts of corrosion-inhibitor consisting of a sulfonic acid-carboxylic acid metal complex or a mixture of said metal complex with a small but effective amount of an oil soluble alkyl phosphate, from 0.1 to 2.0 parts of an oil soluble antioxidant, from 0.0 to 5.0 parts of a water-displacing compound, an effective amount of a mildew-inhibiting compound, and from 0.0 to 1.0 part of a heterocyclic metal deactivator.

Abstract: This invention comprises an acidic aqueous solution for treating metal substrates to improve the adhesion bonding and corrosion protection of the metal surface which comprises effective amounts of water soluble trivalent chromium compounds, fluorozirconates, effective amounts of at least one corrosion inhibitors such as benzotriazole, fluorometallic compounds, zinc compounds, thickeners, surfactants, and at least about 0.001 mole per liter of the acidic solution of a polyhydroxy and/or carboxylic compound as a stabilizing agent for the aqueous solution.

Abstract: An acoustic stringed instrument includes a multi-tiered neck-body joint that removably secures the neck to the body, provides a superior structural and acoustical coupling and enables an expanded treble cutaway that provides improved access to higher regions of the neck and elimination of the neck heel and other external structures in the vicinity of the neck joint.

Abstract: A spectrometric or photo-detector device accessory for illumination of a sample and highly efficient collection of light therefrom includes an ellipsoidal mirror having focal points f1 and f2; a first optical fiber leg having a terminus positioned at or near f1 and containing fibers for conveying light to f1 and collecting light emitted from a sample positioned at f1, a second optical fiber having a terminus positioned at or near f2, for collecting light reflected by the mirror and focussed at f2 and a rigid stand for holding the mirror and fiber optic cables in fixed alignment.

Abstract: A method of fabricating a colossal magneto-resistive detector using a thin film transfer method includes the use of a rock salt structure material as a substrate. In a second embodiment, the method includes the use of a perovskite oxide material as the substrate, and the rock salt structure material as a buffer layer, template layer, and release layer. Advantages associated with the method include not only the ability to produce a detector of the requisite film quality, but one which satisfies the temperature coefficient of resistance and fabrication temperature constraints. In addition, when employed as either the substrate or the buffer layer, template layer, and release layer, after bonding the rock salt structure material can be easily removed using water, and the excess rock salt structure material/water solution can then be removed with known techniques.

Abstract: A SiC gate turn-off (GTO) thyristor that exhibits improved greatly performance includes a p-type anode region, a n-type gated base region positioned beneath the anode region, a n-type drift region positioned beneath the gated base region and doped to a lower concentration of donors than that of the gated base region, a p-type buffer region positioned beneath the n-type drift region and doped with acceptors to a concentration whose magnitude lies between the doping concentration of the anode region and the drift region, and an n-type substrate positioned beneath the buffer region. In another aspect of the invention of this application, a silicon or silicon carbide gate-turn-off thyristor includes a GTO thyristor structure with a thick buffer layer having a high, free-carrier recombination rate.

Abstract: A method of fabricating an uncooled ferroelectric/pyroelectric infrared detector having a semi-transparent electrode material includes using a lattice matched substrate material and a crystallographically oriented bottom electrode material as a template for the growth of a crystallographically oriented ferroelectric/pyroelectric film. In a second preferred embodiment, the method includes fabricating a detector assembly, inverting the assembly, and attaching the inverted assembly to a circuit. This embodiment avoids temperature processing constraints associated with the circuit, and thus facilitates the use of higher growth temperatures. Advantages associated with the embodiments of the present invention include the ability to fabricate a crystallographically oriented bottom electrode material as a template for the growth of a crystallographically oriented ferroelectric/pyroelectric film. Furthermore, once the fabrication is complete, the substrate upon which the electrode is deposited can be easily removed.

Abstract: Red-Green-Blue color-coding of overlaid registered stereo pair imagery from different spectral regions (for example, near-, mid-, and far-infrared) can be used to derive depth perception information. The human preattentive vision process uses coarse spatial structure in the scene to fuse the images for the detection of depth and motion cues. Optimization is accomplished by assigning green to the lowest spatial frequency content image, then red to the next lowest, and finally blue. If the fusion of one of the colored imagery layers produces depth perception information in one portion of the scene whereas the other two colored layers do not, the human mind can retain the information from this color and discard the inputs from the other two colors as noise. The same is true for the other two colors. Human color discrimination and depth perception are combined to greatly enhance preattentive object recognition in the fused stereo pair imagery.

Abstract: A ferroelectric/pyroelectric infrared detector includes a lattice matched substrate material and a colossal magneto-resistive electrode material. In a second embodiment, the ferroelectric/pyroelectric detector includes a colossal magneto-resistive template material to accommodate the use of a non-lattice matched substrate material, and a colossal magneto-resistive electrode material. The embodiments of the present invention provide a semi-transparent electrode material of the requisite lattice constant value, crystal orientation, and chemical compatibility.

Abstract: A terahertz electromagnetic energy detector comprises a (100) oriented multiple quantum well thermally bonded to a first transparent substrate having a direction dependent thermal coefficient of expansion such that this coefficient matches the thermal coefficient of expansion of MQW in one direction but different form the direction-dependent thermal coefficient of expansion of the MQW in a perpendicular direction. The resultant internal thermally induced anisotropic strain leads to a polarization dependence of the optical absorption that is strongest near the lowest heavy-hole and light-hole exciton peaks. A second transparent substrate is placed beneath the first transparent substrate and is oriented so that its thermal coefficients of expansion act in a direction perpendicular to those of the first transparent substrate so that the accumulated phase retardation of the optical wave associated with birefringence of the substrate is effectively cancelled.

Abstract: A single particle photoacoustic absorption spectrometer for directly measuring the absorption spectra for in situ individual aerosol type particles that is comprised of an electrodynamic trap capable of suspending a charged particle in free-space in a non-intrusive manner; a source of modulated monochromatic electromagnetic radiation, e.g., a laser, and an acoustic transducer/resonator for detecting/amplifying sound waves emitted by the irradiated particle. Depending on the characteristics of the particle, a certain fraction of the electromagnetic energy will be absorbed by the particle resulting in its rapid heating and cooling at the modulation frequency. The heat generated within the particle is rapidly transferred to the surrounding air resulting in a sound wave. The intensity of the sound wave is proportional the absorbed energy by the particle.

Abstract: A single particle caloric absorption spectrometer for directly measuring the absorption spectra in situ of individual aerosol type particles comprises a differential arrangement of two identical electrodynamic traps (separated by a series of pneumatic valves) capable of suspending a charged particle in free-space in a non-intrusive manner in one of the traps; a source of monochromatic radiation, e.g., a laser, which is split and directed equally through transmission windows into the traps; and, a high precision capacitance manometer capable of detecting the pressure differential between the traps. After a particle has been trapped in one of the traps and the traps have been sealed from the atmosphere and from each other by the pneumatic vales, the radiation source is turned on and is evenly split/directed into both trap volumes via an appropriate beam splitter and transmission windows. This results in identical illumination of both the target and reference trap regions.

Abstract: The stability of HAN, HAN derivatives or hydroxylamine, and compositions comprising these is considerably enhanced by employing a stabilizing effective amount of a stabilizer selected from (a) a pyridine or pyridone salt, or an acid thereof; (b) a diphosphonate or methylenephosphonate salt, or an acid thereof; or (c) a mixture of two or more stabilizers, wherein at least one is selected from (a) and at least one is selected from (b). Stabilized HAN, HAN derivatives, or hydroxylamine or compositions comprising HAN, an HAN derivative or hydroxylamine, along with a process for providing these stabilized compositions is described. A stabilizer mixture having enhanced, synergistic stabilizing properties is described as well.

Abstract: An ultra-miniature, monolithic, mechanical safety and arming (S&A) device for projected munitions operates in accordance with a double interlock feature. Acceleration of the projected munition moves a delay slider into a final position, causing an arming slider and a safety interlock slider (in a first embodiment) or a command slider (in a second embodiment) to become partially disengaged. In the first embodiment, a command received by the safety interlock slider then moves it out of the way of the arming slider, thereby permitting the arming slider to move into its armed position. In the second embodiment, a command received by the command slider then moves it out of the way of the arming slider, thereby permitting the arming slider, under spring force, to move into its armed position.

Abstract: An electromagnetic launcher includes a single or multi-polar, multi-phase electrical generator powered by an external source; electrical conductors leading from output coils of the generator and from a center point joining the output coils; a plurality of rails connected to the electrical conductors; and an armature having at least two channels; whereby there is at least one position of the armature along the plurality of rails where current flows simultaneously through both of the at least two channels.

Abstract: A frequency-scan traveling wave antenna receives radio frequency (RF) energy at an input port, passes the energy through a quarter wave transformer to a first radiator element in an array of radiator elements, each pair of radiator elements being connected by a respective delay line. Each radiator element includes an input port of known characteristic impedance connected to an impedance matching section which compensates for that element's radiated power. Each radiator element has an output port with a section of transmission line disposed between a main radiator section of said radiator element and said output port, and impedance matched to the output port. In one embodiment, each delay line includes a plurality of delay line sections, with adjacent delay line sections being mutually perpendicular. In a second embodiment, each delay line includes a plurality of delay line sections disposed in meandering form.