Abstract: An apparatus for measuring optical density of highly absorptive materials in which a beam splitter divides light from a laser source into a reference beam, which is directed to a reference detector, and a sample beam, which is reflected off a diffusing plate, through a light limiting aperture, and to a sample. The emanations from the sample are directed to a sample detector. An instrumentation amplifier compares the intensities of the two detectors. The aperture and reference detector are positioned so that the measured intensities are equal, and the optical density of the sample is calculated.

Abstract: A method of determining the carrier concentration depth profile in n-type wide bandgap semiconductor wafers is disclosed. The method includes placing a semiconductor wafer within a photoelectrochemical capacitance-voltage measurement system, in contact with a Schottky electrolyte solution. A high energy ultraviolet light is directed through the electrolyte solution to impinge upon the surface of the semiconductor wafer. The ultraviolet light has an energy greater than the energy bandgap of the semiconductor material and thus facilitates reliable etching thereof. The etch is allowed to continue until a desired depth in the sample is obtained. Upon cessation of the etch, the carrier concentration is determined. The steps of determining the carrier concentration and etching are repeated until the desired carrier concentration depth profile has been obtained.

Abstract: The purpose of the nonlinear spectrophotometer is to provide a simple instrument that can be used on a routine basis to accurately measure the two-photon absorption (TPA) coefficient and cross-section on a wide variety of materials. The instrument is capable of measuring: (1) both organic and inorganic materials, (2) solutions and thin film materials forms, and (3) materials which are fluorescent and nonfluorescent.

Abstract: A high transmission comb-like optical filter structure in wave guiding media is described, an example of which includes multiply periodic modulation of length L=UL.sub.R where U represents an integer number of identical periods of length L.sub.R and L.sub.R is the length of a series of periodically modulated elements of length s.sub.v =M.sub.v d.sub.v, v=1 to V, where M.sub.v is an integer number of cycles of length d.sub.v. Individual filter elements of length s.sub.v of a filter of the invention compared to the reflectors bounding a conventional or series coupled Fabry-Perot cavity exhibit moderate to low reflectivity. Modulation of individual filter elements may be step-wise constant, sinusoidal, or other forms of refractive index modulation.

Abstract: An apparatus and method for calibrating the pressure readings obtained by catheter tip pressure transducers. The apparatus includes a Plexiglas vessel covered by a closure containing eight catheter ports through which the transducers are introduced into the vessel. The vessel is filled with saline solution that has been warmed to body temperature. The transducer ends of the catheters are inserted through airtight hemostatic control valves into the vessel through the catheter ports. Plexiglas guide tubes are used to guide the transducers into the saline solution at predetermined distances below the surface of the saline solution. The distances are used to calculate the hydrostatic pressures exerted upon the transducers by the saline solution. Known pressures are applied to the transducers through an airtight pressure port in the closure. Calculated hydrostatic pressures are added to the known pressures to provide calibration pressures for comparison with monitored pressure readings.

Abstract: A dual explosive charge is described that simultaneously enhances blast and fragmentation characteristics of the charge, including an inner driven charge of a non-ideal explosive surrounded by an outer charge sleeve of a more nearly ideal explosive, detonation of the outer charge resulting in an extremely high temperature, high pressure environment that accelerates reaction kinetics in the inner charge, resulting in enhanced blast and fragmentation performance of the explosive charge.

Abstract: The purpose of the nonlinear spectrophotometer is to provide a simple instrument that can be used on a routine basis to accurately measure the two-photon absorption (TPA) coefficient and cross-section on a wide variety of materials. The instrument is capable of measuring: (1) both organic and inorganic materials, (2) solutions and thin film materials forms, and (3) materials which are fluorescent and nonfluorescent.

Abstract: A fluid filled variable power optical lens is described that includes a substantially tubular shaped housing having in one embodiment an optically transparent elastic membrane disposed over one end thereof and a transparent plate over the second end thereof and defining a chamber for containing an optically transparent fluid and in another embodiment an optically transparent elastic membrane disposed over each end thereof and defining a chamber containing the fluid, and pump assembly for inserting or withdrawing fluid from the chamber whereby each membrane is correspondingly selectively bulged outwardly or inwardly in the shape of a convex or concave lens.

Abstract: A process for treatment and disposal of wastewater having dissolved perchlorate salts is described and includes the steps of adding to the wastewater in a hydrogen gaslift recycle reactor a mixed bacterial culture containing the specific bacterium HAP1 for reducing the perchlorate ion to chloride in the wastewater; maintaining proper nutrient and environmental conditions for HAP1 to optimally reduce perchlorate in the wastewater; and discharging effluent wastewater from the gaslift reactor to an aerobic reactor and maintaining proper nutrient and environmental conditions for the optimal conversion of soluble organics to carbon dioxide and sludge.

Abstract: A tilting apparatus for supporting and restraining a non-human primate animal while conducting research. The tilting apparatus is provided with a table for supporting the animal reclining face down thereon. The table is supported by support means for rotation about a first axis between a horizontal position and a head-down position and about a second axis between the head-down position and a head-up position. Locking means are provided for releasably locking the table in a selected horizontal, head-down or head-up positions. Suitable restraining means are provided which are intersecurable between the animal and the table and function to support and restrain the animal. The animal, while remaining restrained to the tilting apparatus, has free range of motion to feed itself from a water and feeding station. The water and feeding station is supported by an accessory pole. A waste collection system is provided which is connected to the table and which functions for collecting animal waste.

Abstract: High surface area Mo.sub.2 N or MoN electrodes for use in high energy density energy storage devices, and processes for fabricating the electrodes, are described wherein a precursor molybdenum solution is applied to a metallic foil substrate which is heated to produce a MoO.sub.3 coating on the substrate, which coating is converted to Mo.sub.2 N and MoN by reaction with ammonia. Mo.sub.2 N and MoN electrodes are also produced in a chemical vapor deposition process in which molybdenum pentachloride carried by an inert gas and ammonia are the reaction gases for producing Mo.sub.2 N and MoN films.

Abstract: A method for fabricating a gradient index optical filter comprising a thin film having a low refractive index contrast and a specific reflectance function structured using the phase of the refractive index profile as a variable to permit closed form, constrained optimization of rugate filters.

Abstract: An instrument and method for optically calibrating and balancing low level luminances of lighted instrument panel displays within the operator station of a vehicle is described which comprises a self-contained, calibrated luminance source and a beamsplitter for combining and juxtaposing an image of the calibrated luminance source with an image of the luminance from a lighted instrument panel display to be calibrated or balanced, whereby the images may be compared in luminance, the lighted instrument panel display being adjustable in intensity using the vehicle instrument panel light trim capability.

Abstract: A method for the quantitative determination of dissolved oxygen in a liquid fuel includes the steps of doping a sample of the fuel with a preselected concentration of a probe material including a luminophor which exhibits luminescence of wavelength which is quenched by oxygen dissolved in the fuel, illuminating the fuel with light from a coherent light source, such as a laser, of a wavelength which induces the luminescence in the luminophor, and thereafter measuring the change with time of the luminescence from the luminophor in the fuel and determing from the change with time of the luminescence the concentration of oxygen in the fuel.

Abstract: A mask insert to provide conformal support for the reflective seal of an oxygen mask comprising a formed rim made of a resiliently deformable material which is held in place beneath the reflective seal by a supporting framework which conforms to the contours of the interior surface of the mask. The formed rim applies constant pressure on the face-engaging surface of the reflective seal, adjusting for variations in the user's facial structure, thereby eliminating leaks.

Abstract: A method is described for producing homogeneous wrought microstructure during equal channel angular extrusion of difficult-to-work high temperature alloys that exhibit a high degree of flow softening at hot-working temperatures, wherein flow non-uniformities are minimized by imparting an increment of initial upset deformation to an alloy immediately preceding shear flow through the deformation zone.

Abstract: A variable area inlet structure for a vehicle utilizing ram air for coolant is described which comprises a variable area inlet device in the ram air inlet in the form of a butterfly valve, damper, shutter, or similar structure, a temperature sensor in thermal contact with a component within the vehicle to be cooled by ram air flow, a controller and actuator, responsive to the temperature sensor and operatively connected to the variable area device, for controlling the inlet area in response to the component temperature.

Abstract: An electrolysis cell for the efficient production of hydrogen and oxygen is described which comprises a substantially closed housing defining therewithin anode and cathode chambers and having first and second inlets and outlets for flowing electrolyte through the anode and cathode chambers; an ion exchange membrane within the housing separating the anode chamber from the cathode chamber; first and second electrically conductive sheet members disposed within the respective anode and cathode chambers adjacent the membrane and substantially coextensive therewith; discrete electrically conducting ultramicroelectrode particles, preferably in the 5 to 10 micron size range, disposed within the anode and cathode chambers and defining the anode and cathode of the cell; and a source of DC electrical current operatively connected to the first and second sheet members.

Abstract: A method for vibration damping cylindrical members is described which comprises applying constrained damping treatment, in the form of narrow strips of damping tape, to the surface of the member in a helical (barberpole) configuration at a selected pitch angle to a generator line of the member, the tape being either continuous (unsegmented) or segmented at selected optimal length.

Abstract: A method for fabricating a fiber reinforced composite bridge module is described which in one preferred embodiment includes the steps of selecting a cross-sectional shape for the bridge module defined by an outer substantially tubular shell having a top side and a bottom side, and a floor deck near the bottom side and at least one keel beam beneath the floor deck and extending lengthwise of the outer shell, the outer shell, floor deck and keel beams defining a plurality of passageways along the length of the module, winding fiber and impregnating material on mandrels in a plurality tubular sections defining the plurality of passageways, joining the plurality of tubular sections in side-by-side relationship in an assembly substantially defining in cross section the cross-sectional shape of the module, winding fiber and impregnating material around the assembly to a preselected thickness for the outer shell; and curing the fiber and impregnating material.