Abstract: The present disclosure describes an apparatus and a method for inspecting the degradation of a gas nozzle. The nozzle is of the type that can produce a whistle when a gas is blown through the nozzle. The method comprises the steps of detecting an acoustic signal emitted by the nozzle when the gas is blown through the nozzle, the gas having a pressure selected to produce an acoustic resonance at a certain frequency; generating an electrical signal responsive to the detected acoustic signal; band pass filtering the electrical signal at the frequency; and detecting the amplitude of the electrical signal at the frequency. The method also comprises the steps of comparing the amplitude of the electrical signal with a reference amplitude corresponding to a reference nozzle; and displaying a signal indicative of the degradation of the nozzle according to the signal resulting from the comparing step.

Abstract: An electret comprising an inherently charged material is provided. The material comprises phyllosilicate minerals and has external neutralizing ions removed therefrom or external ions added thereto. The electret is manufactured by either removing external ions from or adding external ions to a surface thereof. In a preferred embodiment, the electret is fabricated by placing the material between a pair of electrodes and immersing the material and electrodes in high-voltage insulating medium. A dc potential is then applied across the electrodes to create an electric field across the material. The duration of application of the dc potential is sufficient to provide a large surface charge on the material. The material is then separated from the electrodes while it is still immersed in the insulating medium. The separated material is then removed from the medium to obtain a substantially permanently charged electret.

Abstract: A composite photocatalyst for refractory waste treatment comprising particles of a wide band gap semiconductor material selected from the group consisting of titanium oxide, cadmium sulfide and cadmium selenide, the particles being coated with a polymer film capable of absorbing a refractory waste substrate to be treated and comprising a pyridine-containing polymer and a divalent metal porphyrin or phthalocyanine-based dye. The dye is molecularly dispersed throughout the film and chemically bonded to the pyridine-containing polymer. Upon mixing of the photocatalyst with the refractory waste substrate and irradiation with light having a wavelength of about 300 to about 400 nm, the photocalyst of the invention generates in the polymer film thereof reactive species which are sufficiently oxidizing to degrade the refractory waste substrate absorbed in the polymer film.

Abstract: Optoelectronic switching matrix which switches multiplexed input signals to narrowband output lines. Each crosspoint of the matrix is comprised of a heterodyning photosensor, which optically receives the multiplexed input signal and electrically receives a selectable local oscillator signal. The difference frequency can thus be selected to be within the passband of a low pass filter whereby narrowband output signals can be received from the input signals without requiring the use of a demultiplexer.

Abstract: A method of, and apparatus for, encoding and decoding a sequence of data bytes to permit correction of bit errors occurring in one byte of the sequence, or two bytes providing that the two incorrect bytes can be identified (for example if the bytes show parity failure). Each data byte of the sequence comprises data bits and one parity check bit. To encode the sequence of data bytes two "Code C" code bytes are determined from the data bytes, according to predetermined relationships, the data bytes and code bytes together forming an encoded data block. Also, there is provided a method of, and apparatus for, encoding and decoding a bundle of data blocks to permit correction of a number of bit errors occurring in bytes of the bundle. (Conceptually, the bundle of data blocks comprises a stack of data blocks, one positioned under another to form a two dimensional array of bytes.) Data block bundle encoding consists of separately encoding rows (i.e. horizontal encoding) and columns or pairs of columns (i.e.

Abstract: A breakwater comprised of an array of aligned perforated-wall caissons having a slab bottom standing on a pervious rubble base and anchored by its own weight incorporates exceptionally heavy ballasting to ensure stability under attack by large waves, i.e. to that the ratio of maximum horizontal thrust force to downward vertical force is below about 0.46.The immersed wall height is much reduced so that the slab bottom lies below mean sea level about 1.3 to 1.7 times the height of the greatest wave predicted, lessening costs of construction and siting. Efficient energy dissipation function is preserved by placement of augmenting mass below the height of the wave trough and by providing flow passages for jets directed by front wall ducts, avoiding increase of reflection coefficient.

Abstract: A process for the smelting reduction of oxide ores, in particular iron ores, employs a mixture of the finely divided ore with equally finely divided reductant, which in the case of iron ores preferably is a coal. The mixture is fed into the interior of a heated tubular reaction vessel and moved positively through a heated reaction zone by a screw conveyor embedded in the charge. The conveyor breaks away any accretions that stick to the wall before they can build to a size that will stall the conveyor. The particles are in the range 75-1400 micrometers with a preferred size of at least 95% less than 600 micrometers, and the preferred ratio of ore to reductant is in the range of ratios 18:82 to 30:70. The reduced iron can be fed directly into a melting furnace for separation of metal and non-metal, it can be powdered and separated magnetically or it can be briquetted.

Abstract: A method for the detection of delaminated areas in coated materials or layered composites, which allows free-air operation and can be used to scan portions of bulky materials on the spot. This method which makes it possible to detect very small delaminated areas in a very short time (less than 1 millisecond), with a very high sensitivity and without creation of excessive thermal stress in the inspected material, basically comprises the steps of: focusing pulsed, thermal radiations onto the structure to be inspected to produce a vertical displacement of its coating by thermal expansion if a delaminated area is present at the coating-to-substrate interface, and detecting and measuring this vertical displacement if any, by interferometry, preferably laser-beam interferometry. An apparatus for carrying out this method is also disclosed.

Abstract: A birefringent single-mode acoustic fiber for propagating linearly polarized shear acoustic waves while preserving linear polarization, comprises an elongated core region of a solid material in which acoustic waves can be propagated in two orthogonal shear mode components, and a cladding region enclosing all surfaces of the core region except end surfaces thereof, the cladding region being also of a solid material in which acoustic waves can be propagated in two orthogonal shear mode components.

Abstract: In a percussive tool in which a very high pressure and preferably cavitating water jet is directed through an opening in the working surface of the tool, the jet is formed by a nozzle positioned in a cavity behind the opening and decoupled from the tool by a bearing layer of water from the jet. A supply pipe extends rearwardly of the nozzle without contacting the tool, and is supported externally of the tool, on a machine which operates the tool, by a support which allows the fluid bearing to center the nozzle within the cavity while restraining movement of the nozzle axially of the tool.

Abstract: An optoelectronic assembly for converting a signal between optical and electrical form, or vice versa, consists of a dielectric substrate and a semiconductor substrate. These substrates are fabricated separately and then brought together with major faces in intimate contact with each other. The dielectric substrate has a pair of metallic electrodes on its surface and a waveguide extending to a coupling region. The semiconductor substrate has an active optoelectronic device, e.g. a photodetector or light emitting device, whose optically active portion is brought into optically coupling relationship with the coupling region of the waveguide. At the same time electrically contacting regions of the optoelectronic device are placed in electrical contact with respective ones of the pair of metallic electrodes on the dielectric substrate.

Abstract: An optoelectronic switching matrix which can be configured to form a variety of signal processing elements, such as a digital switched filter, a digital word generator, a programmable bandpass filter, programmable delay, etc. Optical or electronic delay apparatus is connected between output and input ports of the matrix, and can be switched to provide delays or resonant loops. A versatile signal translation element is thus realized.

Abstract: A detector for charged particles, i.e. secondary electons ir ions emitted from a bombardment area of a specimen in an instrument such as a scanning electron microscope or analytical instrument, consists of a collector, e.g. a scintillation surface highly charged with a voltage of the opposite polarity from that of the particles, for receiving the particles and providing an output proportional to the number thereof. A grid, charged with a voltage of the same sign as the scintillation surface, but to a lower value, is located between the scintillation surface and the bombardment area, and a probe in the form of a wire electrically connected to the grid projects into the vicinity of the bombardment area which is in a confined space between the specimen and the instrument. The result is to set up an electrostatic field around the wire, causing a significant number of the charged particles to orbit the wire and travel to the scintillation surface.

Abstract: Disclosed herein are organometallic ternary charge transfer complexes of the formula (I)a(RX).multidot.MX.multidot.b(Ar) (I)whereinRX is an inorganic chloride or fluoride which contains at least one oxygen and/or sulfur atom and is capable of forming a complex salt a(R).multidot.MX.sub.(a+m) with the Lewis acid MX.sub.m, such as NOCl or NOF,MX.sub.m is a Lewis acid metal chloride or fluoride, such as BCl.sub.3, BF.sub.3, AlCl.sub.3, GaCl.sub.3, TlCl.sub.3, AsCl.sub.3, AsF.sub.5, SbCl.sub.5, FeCl.sub.3, SnCl.sub.4, TiCl.sub.4, ZrCl.sub.4, NbCl.sub.5, TaCl.sub.5, MoCl.sub.5 and WCl.sub.6,Ar is an aromatic compound, such as napthalene, anthracene, thiophene, furan and benzene which is unsubstituted or substituted with lower alkyl, halogen, diloweralkylamino, oxo or lower alkoxy,m is an integer representing the valency of the metal M,a is an integer selected such that the sum of a and m does not exceed the coordination number of the metal M of the given valency,b is 0.

Abstract: The position of a peak in a digital signal is determined by a circuit consisting of a finite impulse response filter constructed in accordance with either the expression (1+z.sup.-1)(1+z.sup.-2) (1-z.sup.-5) or the simplified expression (1+z.sup.-1) (1-z.sup.-3), where z is the z transform function and the index indicates the number of clock intervals in each delay. The practical realization of the filter for applying these expressions to the input signal involves the use of three (for the first expression) or two (for the second expression) delay circuits in series. The output of the filter is a differentiated signal, the zero crossing point of which represents the desired peak position. This crossing point is detected in an interpolation circuit which linearly interpolates the location of such point to a fraction of a clock interval or pixel.

Abstract: An imaging device employs a known bidimensional, position sensitive light detector of the CCD type. A converging lens system images points on a target surface onto the detector to generate data on the X and Y coordinates of each point. The invention is characterized by a mask located in the aperture plane of the lens system. This mask either has a pair of spaced apart, separate, circular apertures or an annular aperture symmetrical about the optical axis. In the first instance, the result is to form spaced-apart dots on the detector for each point of the target surface, the distance between these dots being a measure of the Z coordinate of the respective point. When using the annular aperture, rings are formed on the detector, the ring diameter representing the Z data. The arrangement provides a compact and robust device for obtaining three dimensional data on a target surface.

Abstract: A signal processor for providing a continuous raised cosine output signal having no jitter or intersymbol-interference and with controllable main and side lobes. An NRZ input signal is converted to a double interval raised cosine pulse signal having an amplitude normalized to 1.0. Another single interval raised cosine pulse signal having a peak amplitude (A-1) is superposed with the former raised cosine pulse to provide the output signal.

Abstract: A converter for converting a series of digital input bits to an analog output employs a direct current comparator having a magnetic core and primary and secondary ratio windings coupled with the core. The primary winding is divided into two sections. A first group of the more significant input bits varies the number of turns of the first primary section which is traversed by a first direct current. A second group of less significant input bits varies the number of turns of the second primary section traversed by a second direct current. A direct current is also passed through the secondary winding, this secondary current being varied proportionally with the number of turns of the first primary section traversed by the first primary current. Modulation-detection windings arranged inside the core (which also acts as a magnetic shield) detect any net ampere-turns unbalance of the primary and secondary currents in the ratio windings.

Abstract: The invention is concerned with a laser heterodyne interferometric method and system for measuring the displacement of a free surface of a material subjected to ultrasound. A laser beam having a predetermined intensity is generated and then divided into first and second beam portions having respective intensities representing minor and major fractions of the predetermined intensity, the first beam portion being angularly displaced relative to the second beam portion and being frequency shifted by a predetermined frequency. The second beam portion is passed through an optical lens off-center thereof to focalize the second beam portion onto the free surface of the material subjected to ultrasound, thereby scattering same. The scattered second beam portion is combined with the first beam portion to obtain an optical fringe signal which is converted into an electrical fringe signal comprising a central peak at the predetermined frequency and a sideband on either side of the central peak.