Abstract: An electrochemical cell for measuring concentrations of metal ions comprises a sampling enclosure including a working electrode, a reference electrode, and a counter electrode. Ports are provided in the sampling enclosure for the introduction and removal of a liquid sample, an auxiliary reagent, and a standard solution. A stirring mechanism maintains a uniform composition of the liquid sample during operation of the cell. The electrochemical cell is operated by introducing the liquid sample into the sampling enclosure, applying a plating voltage between the working electrode and the counter electrode, and measuring the voltage response of the working electrode when the applied voltage is removed. The concentration of metal ions is then calculated from the voltage response. A standard solution is added to the liquid sample, after which the measurement is repeated to calculate the concentration of metal ions relative to the standard solution.

Abstract: A process for developing conductive interconnect regions between integrated circuit semiconductor devices formed on an insulating substrate utilizes the semiconductor material itself for formation of device interconnect regions.A patterned layer of semiconductor material is formed directly on the surface of an insulating substrate. The patterned layer includes regions where semiconductor devices are to be formed and regions which are to be used to interconnect terminals of predetermined ones of the semiconductor devices. After forming the semiconductor devices in selected regions of the semiconductor material, the regions of the semiconductor material patterned for becoming interconnects are converted to a metallic compound of the semiconductor material.

Abstract: The adaptive parameter kernel processor of the present invention uses an adaptive locally optimum detection (ALOD) signal processing algorithm to suppress interfering signals in a communications signal. The adaptive parameter kernel processor generates a signal magnitude value for each signal sample, partitions the signal magnitude values into sets, and concurrently executes multiple copies of the ALOD signal processing algorithm. Each copy of the signal processing algorithm applies a probability density function to the sets of signal magnitude values, generating a gain factor for each set. The probability density function includes a parameter that has a different value in each copy of the signal processing algorithm. Each copy of the signal processing algorithm generates an average gain factor associated with the corresponding parameter value.

Abstract: A pre-processor and adaptive beamformer processes an echo received by an array of receiving elements from a distant target from a transmitted signal having an arbitrary waveform capable of being represented as a complex modulation of a carrier frequency. Time blocks are formed from each element output represented by a series of time windows extending from an initial time appropriate to the arrival time of the echo to a final time appropriate to the time block. A correlation is performed of each time block with a replica of the transmitted signal. The correlation products are aligned with respect to time difference to within one sample period. The beamformer further aligns the correlation products with respect to time difference to substantially the same phase for each steering direction. Covariance estimates are formed using techniques of spatial averaging to generate adaptive weights optimized to suppress interfering signals without requiring the use of time averaging.

Abstract: A method and apparatus for producing stimulated emission from a laser gain element containing an organic dye are described in which optical pumping is produced by visible laser diodes. Low threshold pump power and high optical conversion efficiency are achieved by producing a laser resonator mode waist at or near the laser gain element and spatially superimposing a pump mode waist at or near the laser resonator mode waist. Using low power visible AlGaInP laser diodes and the dyes rhodamine 700, oxazine 750, DOTCI or oxazine 1 in the laser gain element, incident pump threshold powers as low as 5.4 mW, optical conversion efficiencies of 49% and tunable emission between 700 nm and 800 nm were achieved. This laser was scaled to higher cw output power by using a DCM-based pump dye laser. In a preferred embodiment the laser resonator has two reflective elements in a nearly hemispherical configuration. Angular multiplexing of laser diodes to scale to higher laser diode pump power is described.

Abstract: A direction finding apparatus and method for an RF signal are described which provide a variable time delay in fiber optic cables. A tunable transmitter launches optical emissions of several wavelengths into a plurality of fiber optic cables. Since the waveguide material of each cable exhibits anomalous dispersion of the optical emissions, large changes in group refractive index are provided as a function of the different wavelengths of the optical emissions. As a consequence, only small changes in the different wavelengths of the optical emissions produce large changes in the time delay of the different wavelengths of the optical emissions within a fixed length of the optical fiber cables. This apparatus and method produce sensitive angle of arrival determinations for RF signals.

Abstract: A tunable laser produces laser emission at at least two wavelengths simuleously. The tunable laser includes at least two gain elements, where each gain element generates a different wavelength. Means for optically exciting each laser gain element is appropriately disposed for either end pumping or side pumping to produce a laser emission within a preselected range of wavelengths. A wavelength dispersing element such as a prism is disposed in the laser resonator cavity for dispersing the wavelengths operating simultaneously within the laser resonator cavity and to create separate regions for each laser gain element. Laser gain elements may be tunable laser gain elements or discrete emitting laser gain elements. Arbitrarily large wavelength separations between the wavelengths operating simultaneously may be achieved in this manner producing stable cw or pulsed output, Q-switched or line narrowed depending on the means disposed within the laser resonator cavity.

Abstract: A method for forming a semiconductor structure having a layer of low minority carrier lifetime and a layer of high minority carrier lifetime comprises the steps of forming a silicon dioxide layer on a layer of low minority carrier lifetime silicon of a silicon-on-sapphire handle wafer and another layer of silicon dioxide on a layer of high minority carrier lifetime silicon of a bulk silicon device wafer. The silicon dioxide layers are placed in contact and annealed to form a bonded structure having an annealed layer of silicon dioxide. The layer of bulk silicon is then thinned. The thinned layer of bulk silicon and the annealed silicon dioxide layer are patterned by photolithography to form mesas of high minority carrier lifetime silicon and to expose regions of low minority carrier lifetime silicon on the bonded structure.

Abstract: An apparatus for detection of thermal neutrons includes a volume of gas which includes .sup.3 He. A wavelength shifting optical (WSO) fiber is disposed to receive ultra-violet (UV) photons generated by reactions between neutrons and .sup.3 He. UV photons are absorbed within the WSO fiber to produce longer wavelength fluorescence generated photons that propagate within the WSO fiber. A photodetector is disposed to receive fluorescence generated photons from at least one end of the optical fiber and provide an output signal corresponding to neutron detection.

Abstract: A frequency agile laser illuminates a scene with floods of emissions of different wavelengths. As the wavelengths, or laser color changes, certain objects will stand out with respect to their background so that detection and recognition is enhanced to permit appropriate action. This technique has application in the location of underwater objects.

Abstract: A photoneutron detection apparatus comprises an X-ray generator and a neutron detector adapted for placement in proximity to subsurface soil. The X-ray generator produces timed pulses of X-ray photons having a range of electronically controlled energies which penetrate the subsurface soil to produce photoneutron emissions that are received by the neutron detector. The neutron detector generates a signal representative of the neutron flux. A signal analysis system time correlates the signal with the timed X-ray pulses to determine the presence of selected contaminants.

Abstract: An apparatus for producing a wound cable pack having uniform pitch and inporating a twist per turn in a cable. A drum is constrained to rotational movement around an axis of rotation. A non-rotating spool, sized to fit within the drum and having a central longitudinal axis coaxial with the drum's axis of rotation, is constrained to linear movement along the axis of rotation within the drum. A cable feeding assembly is mounted to the drum for rotation therewith. The cable feeding assembly leads the cable over one end of the spool prior to being fed onto the spool from a feed point. In this way, a twist is induced in the cable as the cable feeding assembly orbits about the spool. An electromechanical system is operatively connected to the drum and the spool to synchronize the rotational movement of the drum with the linear movement of the spool.

Abstract: A circuit for regulating floating gate injection voltage comprises a volt regulator electrically coupled to a floating gate device. The floating gate device includes an electrically conductive floating gate capacitively coupled to a programming terminal by an injection capacitance and to a bias terminal by a bias capacitance. The voltage regulator establishes a substantially constant rate of charge onto the floating gate when a programming voltage is applied to the floating gate device and the voltage regulator.

Abstract: A method for forming a semiconductor structure having a layer of low minority carrier lifetime and a layer of high minority carrier lifetime comprises the steps of forming a silicon dioxide layer on a layer of low minority carrier lifetime silicon of a silicon-on-sapphire handle wafer and another layer of silicon dioxide on a layer of high minority carrier lifetime silicon of a bulk silicon device wafer. The silicon dioxide layers are placed in contact and annealed to form a bonded structure having an annealed layer of silicon dioxide. The layer of bulk silicon is then thinned. The thinned layer of bulk silicon and the annealed silicon dioxide layer are patterned by photolithography to form mesas of high minority carrier lifetime silicon and to expose regions of low minority carrier lifetime silicon on the bonded structure.

Abstract: A pre-processing method and pre-processor decomposed a first problem belong to a class of linear algebra problems comprising an input sparse symmetric matrix into a suite of sub-problems. The pro-processor generates a suite of signals representing the information content of a permutation of the rows and columns of fire sparse symmetric matrix. These signals are used to define a block-bordered block-diagonal form leading to a Schur-complement resolution wherein each sub-problem corresponds to a perfect parallelism in the first problem. The preprocessor allocates the sub-problems to sub-processors in a network of parallel architecture computers. The sub-processors solve the sub-problems concurrently and combine the results in a front-end computer, which outputs a solution to the first problem.

Abstract: A current controlled variable inductor comprises a magnetically saturable E" core having outer limbs each joined to a center limb by connecting limbs. A staggered series of flux bridges and air gaps are formed into alternating sides of the outer limbs. A bias winding on the center limb magnetically couples a direct current into the core to vary the inductance of a signal winding on the outer limbs. A secondary winding magnetically couples an output voltage from the core for application of the inductor as a tunable transformer.

Abstract: An instantaneous bit-error-rate meter provides an instantaneous, real-time eading of bit-error-rate for digital communications data. Bit-error pulses are input into the meter and are first filtered in a buffer stage to provide input impedance matching and desensitization to pulse variations in amplitude, rise-time and pulse-width. The bit-error pulses are transformed into trigger signals for a timing pulse generator. The timing pulse generator generates timing pulses for each transformed bit-error pulse, and is calibrated to generate timing pulses having a preselected pulse width corresponding to the baud rate of the communications data. An integrator generates a voltage from the timing pulses that is representative of the bit-error-rate as a function of the data transmission rate. The integrated voltage is then displayed on a meter to indicate the bit-error-rate.