Abstract: A sensor comprises an optical sensor fiber which has a microbend module engaged thereto. When the module is subjected to external influences such as pressure, displacement or the like, it places microbends in the sensor fiber which changes a light transmission characteristic of the fiber. Light passing through the sensor fiber is detected, and changes in the light are measured to find the influence on the modulator. A scintillating or florescent source fiber connected to one end of the sensor fiber is exposed to radiant energy. This produces light which is channeled to the sensor fiber as the light source for the sensor fiber.

Abstract: A non-intrusive vibration measurement system and method using commercial ultrasonic instruments together with digital signal filtering and analysis techniques is adapted to quantitatively detect vibrations as small as 0.04-inch peak-to-peak. The system and its methodology is used for in-service vibration monitoring of internal components of check valves, pumps, nuclear reactors, steam generators and heat exchangers, especially when the vibration frequency is too low for quantitative analysis by accelerometers and when the strain induced is too low for strain gauge analysis, and when the vibrating component is in an "encased" environment.

Abstract: A fiber optic loop temperature sensor employs a fiber optic loop (90) having a predetermined fixed radius where a light source (96) supplies light to the signal optical fiber (92) with the loop and a second reference optical fiber (100) receives light from the light source (96) for providing a reference light intensity. The light intensities from both optical fibers are measured and the temperature is determined from differences therein. Advantageously, the fiber optic loop temperature sensor is employed in a temperature compensated, self-referenced fiber optic microbend pressure transducer to compensate for thermal offset of the microbend sensor output. In the preferred embodiment, time division multiplexing provides at least two bi-cell photodetectors (82) with output and source signals for generating a log ratio output for determining the sensed parameter independent of cable and connector offsets and light source fluctuations in addition to compensation for thermal offset.

Abstract: An apparatus and method for the measurement of low levels of carbon dioxide in a sample employing membrane separation and ion-exchange technology. The difference in acid strength of carbonic acid and other acids is exploited by treating the sample with a weak base in a membrane separator (10). In this manner, the carbonic acid is distinguished from the stronger acids.

Abstract: A method and apparatus for distinguishing between hydrogen damage in the wall of a boiler tube, and surface damage on the inside surface of the tube, comprises a pair of transducers which are spaced on the outer surface of the tube and which apply a refracted shear ultrasonic wave through a chord of the tube with a beam angle that is calculated from the outside radius and wall thickness of the tube. The transducers are first applied to an undamaged tube and an instrument connected to the transducers is adjusted to 80% of full screen height. The same transducers are then, applied to a suspected boiler tube. Any attenuation of the initially high amplitude below 12 dB indicates hydrogen damage as opposed to inner surface damage which has been found to produce a far lower attenuation.

Abstract: A method of increasing intergranular stress corrosion cracking resistance of Alloy 718 in water reactor environments is described where the alloy is heat treated at a high solution annealing temperature to dissolve grain boundary precipitates formed during thermomechanical processing. A water quenching step is advantageously employed following the high solution annealing. The alloy is then aged at two separate temperatures and finally air cooled to room temperature.

Abstract: An improved method for making a composite tube (10) to a carbon steel tube (16) joint or a composite tube (10) to a carbon steel header (50) joint is achieved by specially preparing the composite tube (10) by removing the cladding (12) from one end (24) to a predetermined length to provide base carbon steel material (14). The end (24) of the composite tube has cladding (12) tapered at a predetermined angle. This end (24) is then expanded. The composite tube (10) is then welded to the carbon steel tube (16) with fewer weld passes while also eliminating the stainless steel weld pass.

Abstract: A sliding backpurge device for supplying shielding gas to an arc welding process comprises a concave primary gas chamber surrounded by inner and outer seals which define a pressurized secondary gas chamber therebetween. Pressurized secondary gas is supplied to the secondary gas chamber and primary gas is supplied to the primary chamber. Any leaks which do form, minimize impact on the shield gas within the primary chamber despite sliding engagement of the inner and outer seals over the surface to be welded since secondary gas rather than atmospheric gas leaks into the primary chamber.

Abstract: A method and apparatus for measuring the internal temperature of a work piece comprises an excitation laser for generating laser pulses which are directed through a water cooled probe, and in an optical fiber, to a first surface of the work piece. The laser is of sufficient intensity to ablate the surface of the work piece, producing a displacement and a resulting ultrasonic pulse which propagates within the thickness of the work piece to an opposite surface. The ultrasonic pulse is reflected from the opposite surface and returns to the first surface to create a second displacement. A second continuous laser also shines its light through an optical fiber in the probe into the first surface and is used in conjunction with signal processing equipment to measure the time between the first and second displacements.

Abstract: An apparatus and method for providing a real-time video display and a temperature map display of an object, in particular a flame, comprises a single CCD video camera and optical equipment which focuses separate light bundles onto a photosensitive surface of the camera. A separate band pass filter is used in each light bundle to filter selected different wavelengths of light. The video signal from the camera is used in a video digitizer to obtain data which can be used to calculate a temperature map based on the different wavelengths of light of the two bundles. The video signal is also used to produce a real-time video display of the object.

Abstract: A plasma arc welding process for welding metal of increased thickness with one pass includes operating the plasma arc welding apparatus at a selected plasma gas flow rate, travel speed and arc current, to form a weld having a penetration ratio to weld height to weld width, and maintaining the penetration ratio at less than 0.74. Parameters for the plasma gas flow rate, travel speed and arc current are adjusted to a steady state condition during a start up period and maintained during the steady state condition to complete a weld. During a terminal stopping period, the travel speed is stopped and instantaneously replaced by filler wire which adds material to fill the keyhole that had been formed by the welding process. Parameters are subsequently adjusted during the stopping period to terminate the weld in a sound manner.

Abstract: A fiber optic apparatus and method for monitoring color balance of a product that can consist of a complex two dimensional color pattern. This system employs at least one illuminating optical fiber (18) and at least two pick-up optical fibers (16). Filters (36) associated with each of the pick-up fibers (16) separate the reflected light into different color components. Photodetectors (38) convert the light intensity from each fiber (16) into analog electrical signals which are routed to a microprocessor based signal processing module (10) for conversion to digital output and subsequent analysis for monitoring color balance. If there is a change in color balance, a visual and/or acoustic alarm (62) is automatically activated.

Abstract: A method of constructing a nozzle having cooling channels comprises a shell and a liner which are formed into a body of revolution having an axis of revolution. Helical welds are formed to hold the liner and shell to each other with a channel position being defined between each pair of helical welds. Pressurized fluid which may be a gas or a liquid, is introduced between the weld pairs to outwardly bulge the material of at least one of the liner and shell to define the channels.

Abstract: A method and appartus for measuring lignin concentration in an undiluted sample of wood pulp or black liquor comprises a light emitting arrangement for emitting an excitation light through optical fiber bundles into a probe which has a sensing end facing the sample. The excitation light causes the lignin concentration to produce fluorescent emission light which is then conveyed through the probe to analyzing equipment which measures the intensity of the emission light. Measures are taken to maximize the emission light intensity which is due to lignin concentration and distinguish it from background and interfering light. The fluorescent light intensity is found to drop off in a predictable manner with increased lignin concentration.

Abstract: A method and apparatus for measuring lignin concentration in a sample of wood pulp or black liquor comprises a light emitting arrangement for emitting an excitation light through optical fiber bundles into a probe which has an undiluted sensing end facing the sample. The excitation light causes the lignin concentration to produce fluorescent emission light which is then conveyed through the probe to analyzing equipment which measures the intensity of the emission light. Measures aThis invention was made with Government support under Contract Number DOE: DE-FC05-90CE40905 awarded by the Department of Energy (DOE). The Government has certain rights in this invention.

Abstract: A method of removing sulphur oxides from flue gases comprises atomizing a wet alkali slurry into a slurry spray. A pneumatically conveyed dry reactive recycled flyash is supplied in an annular pattern around the slurry spray to efficiently utilize the flyash without experiencing difficulties which were experienced in the prior art with regard to a wet mixture of the flyash.

Abstract: A buckstay system for a membraned-tube wall having a first wall section which meets a second wall section at an angle to form a corner, utilizes the natural load carrying ability of membraned tube wall construction to simplify or eliminate structural components previously utilized at such locations. Some embodiments use the membraned-tube wall corner configuration alone, or in combination with corner reinforcing plates and/or stiffening members to distribute combustion gas pressure loads to adjacent membrane-wall panels. Other aspects provide reinforcement only to accommodate transient overpressure conditions.

Abstract: A bi-metallic extrusion billet perform is produced in a single casting. An inner core made of a desired material is placed in the center of a crucible or mold as a prepared bar. Molten cladding material is cast into an annular area between the outside surface of the inner core and an inner surface of the crucible or mold. Bottom pouring is enabled through the center of the inner core, which has been appropriately provided with a hole of a size that is consistent with the extrusion press and the required extruded hollow size involved in later manufacturing steps. The entire operation, including the melting of the cladding material, is advantageously performed under a vacuum to eliminate the risk of trapping air at an interface between the inner core and the cladding material cost therearound.

Abstract: An improved method for aluminizing a ferritic material by forming an aqueous aluminum slurry composition, applying the aqueous aluminum slurry composition to the ferritic material to form a coating, adding a halide activator to the coated ferritic material and heating the coated ferritic material to a temperature of about 1275.degree. F. to about 1300.degree. F. for approximately 24 hours. The use of the lower temperature thermal cycle minimizes the change in the mechanical properties of a steel substrate.

Abstract: A fiber optic fluid opacity sensor includes a light source (12) transmitting light to dividing means (14) for providing a sample light signal (18) and a reference light signal (20) to dual photodetectors (26, 28). Sample and reference optical pathways (19, 21) are defined by optical fibers (18, 20) spaced apart from and axially aligned with the photodetectors (26, 28) at a predetermined distance. Signal processing means (30) takes the log ratio output of the signals from the photodetectors (26, 28) for cancelling the effect of light source drift since the same source (12) is common to both for measuring the light transmission and determining opacity therefrom. A sample probe (40) contains the photodetectors (26, 28) and the sample and reference optical pathways (19, 21). The light source (12) and the signal processing means (30) are situated outside of the probe (40) and by virtue thereof outside of the sample process line (48).