Abstract: A central node in a network computes for, and sends to, each node a forwarding table which consists of the set of neighbors to which the node should forward a message intended for a particular destination. The message includes a version number in the packet field header indicating which forwarding table version the node should use to forward the packet. The node does not begin marking and forwarding packets according to the new version number immediately. The node may wait a period of time after receiving the new table or may wait until receiving notification from the fabric manager to begin using the new version number. When a node receives a message from an end node, it inserts either the most recently received version number in one embodiment or uses the version dictated by the fabric manager in another embodiment.

Abstract: Magnetic force from a momentarily excited coil (34) results in oscillatory flexure of a flexible diaphragm (30) loaded on one side by a liquid (10) whose level is to be measured. A permanent magnet (42) mounted on the diaphragm (30) so moves with diaphragm flexure as to vary the magnetic saturation of a saturable circuit in which the coil (34) generates flux. By determining the coil's inductance under quiescent-diaphragm conditions, a computer (56) can infer the ambient pressure that bears upon the liquid (10). By compensating for the static pressure thus inferred, it can then determine liquid level by observing diaphragm oscillations reflected in coil electromotive force generated by the magnet (42) as the diaphram (30) undergoes oscillatory flexure in response to the coil's momentary excitation.

Abstract: A database-management system (10) generates bounded-disorder indexes on its database keys. In such an index, the leaf nodes (51, 62) are large and are divided into a number of buckets (52, 54, 56, 58), only one of which ordinarily is accessed in any given single-record database operation. The key values in a leaf node are distributed among the leaf node's buckets in accordance with a hashing function. The lockable ranges locked for scanning functions are defined in accordance with key-valued locking, in which each lockable range is bounded by successive key values that exist in the database. But the multiple-bucket accesses that would otherwise be required, because of the hash-function distribution of key values among a node's several buckets, are avoided because the lockable ranges are defined by the sequence of key values in the bucket rather than in the node.

Abstract: A bubble rake for removing the remaining steam from liquid water that is returning to heat-exchange surfaces after an initial separation from steam. The bubble rake is a channel-forming member having a cross section generally in the shape of an upside-down U. The bubble rake is disposed in a fluid-flow path so that the channel opens down and in the direction of the path. A stall zone formed by a rake traps steam in the channel, and the channel is positioned longitudinally at an angle with the horizontal so that the trapped steam migrates to its high end, where an opening allows the trapped steam to join the steam previously separated from the water.

Abstract: Particulates removed from the flue gases produced in a fluidized-bed furnace are separated into high-and low-density portions. The low-density portion is predominantly char, and it is returned to the furnace or burned in a separate carbon burnup cell. The high-density portion, which is predominantly limestone products and ash, is discarded or reprocessed.According to another version, the material drained from the bed is separated, the resulting high-and low-density portions being treated in a manner similar to that in which the flue-gas particulates are treated.

Abstract: A method and apparatus for strip cladding into a corner while magnetically agitating the weld deposit. The clad strip is angled away from the corner in the plane of the electrode strip, and means are provided for using the corner-forming obstruction as a pole piece for the electromagnet. The welding head can thereby be positioned to clad into the corner without interference from an obstructing pole piece or from the welding head itself.

Abstract: A method and apparatus for transmission of ultrasound to and reception of ultrasound from a fluid from outside its container. An ultrasonic transducer generates sound waves longitudinally in a transmission bar that has a reflecting surface at such an angle with the ultrasonic path that the longitudinal waves are internally reflected as shear waves in the direction of an interface between the transmission bar and the fluid. The impinging of the shear-mode waves on the interface results in an efficient transmission of energy into the fluid and an efficient reception of echo signals from the fluid. Since longitudinal waves are coupled from the transducer to the metal, a rigid bond between transducer and metal is unnecessary. The coupling may be achieved by means of a liquid-filled interface that does not subject the delicate transducer to damage from stresses produced by differential thermal expansions.

Abstract: In order to determine the percentage of suspended solids in a slurry, a hollow tube is extended into a slurry tank in which the solids are kept in suspension by a mixer. The tube allows the liquid within it to be isolated from the action of the mixer, so the solids settle out of the tube. A pressure difference between points at the same elevation inside and outside of the tube is measured, and this gives a percent-solids indication in which error due to dissolved solids is negligible.

Abstract: An improved method and apparatus for operating magnetic stepping-type mechanisms. The current flowing in the coils of magnetic stepping-type mechanisms of the kind, for instance, that are used in control-element drive mechanisms is sensed and used to monitor operation of the mechanism. Current waveforms that characterize the motion of the mechanism are used to trigger changes in drive voltage and to verify that the drive mechanism is operating properly. In addition, incipient failures are detected through the observation of differences between the observed waveform and waveforms that characterize proper operation.

Abstract: An improved high-water-level trip control for a steam turbine is disclosed. Instead of causing a trip of the turbine (or reactor) based merely on the water level in the steam generator, the present invention generates a trip command that is based on a function of more than one parameter. Such a function more accurately indicates the quantity of water droplets in the steam leaving the steam generator than a function of a single parameter does. In particular, it is disclosed to trip the turbine when the water level exceeds a variable reference that increases as steam velocity decreases; this takes into account the effect of steam velocity on the entrainment of water droplets by the steam.

Abstract: Improved circuitry for regulating the average power supplied by an AC source to a load includes switching circuitry that the power applies to the load for integral numbers of full cycles of the AC source. Control of the circuit for switching the power on and off is accomplished by sensing and storing the peak current drawn by the load during the most recent application of power, reducing the stored quantity linearly with time, and causing another application of power wnen the stored quantity has dropped below a predetermined threshold.

Abstract: A holddown column for preventing upstream motion of nuclear-reactor fuel assemblies during operation of the reactor is disclosed. The holddown column is a composite of three concentric individual columns. Lips on the intermediate column engage the other two columns so that the intermediate column expands under load as the other two columns contract. This results in a greater deflection of the column under load than would result if the column were only a single column, but the thermal expansion experienced by the composite column is not different from the thermal expansion experienced by a simple column of the same material and length.

Abstract: An apparatus for preventing "floating" of nuclear-reactor fuel assemblies due to hydraulic forces is disclosed. The apparatus uses a holddown column made of the same material as the core barrel. The column is positioned in a center guide-tube location in the fuel assembly in such a manner as to enable it either to slide within the center guide tube or, if the center guide tube is replaced by the column, to slide through openings in the spacer grids. The lower end of the holddown column engages the lower end fitting of the fuel assembly, and the upper end of the column engages a flow plate to which holddown force is applied. As a consequence of this arrangement, holddown force is transmitted from the flow plate through the holddown column to the lower end fitting. Movement of the fuel assembly is thereby prevented without a compression load being applied to the fuel-assembly structure.

Abstract: A method is disclosed for making a ring for sealing the opening between a reactor vessel and the wall of the cavity in which it sits. The method permits forming the sealing ring in segments at an off-site location, thereby eliminating the transportation problems encountered with an integral sealing ring. According to the method, seals and coatings can be applied to the individual segments before the segments are shipped, and the seals and coatings are completed when the sealing ring has been assembled at the site. This allows a segmented ring to be provided without high on-site fabrication costs.

Abstract: A device for discriminating between the presence of flame in a selected position and the presence of flame in nearby locations within a combustion area is disclosed. A means for detecting electromagnetic radiation having wavelengths known to be characteristic of the base of the flame but not of the rest of the flame is aimed at the position at which the base of the flame to be monitored will occur if the flame is present. The intensity of the radiation having the given wavelengths is compared with the intensity of radiation having nearby wavelengths, and the relative magnitudes of the two intensities are used as an indication of whether flame is present or absent at the selected position.

Abstract: An apparatus for compensating for line voltage variations in a pulsed welding arc supply. A circuit for drawing a current that is proportional to that part of the supply voltage in excess of a predetermined reference is drawn from the capacitor charging circuit in a UJT triggering device. Thus, the more the line voltage exceeds the desired level, the greater is the compensating current withdrawn from the capacitor charging circuit. As a result, the average welding current remains at the desired level despite supply-voltage variations.

Abstract: An apparatus is disclosed for realizing analog signal filters with very long time constants. In order to avoid the losses inherent in conventional energy-storage devices such as capacitors and inductors, an analog signal is converted into digital form for storage, thereby eliminating losses, and the digital quantity is continuously converted back to analog form for use in the analog circuit.

Abstract: An output stage and feedback circuit for a buffer amplifier are disclosed. The output stage protects an operational-amplifier circuit preceding it from overvoltages appearing at the load. The circuit includes a pair of complementary transistors in a push-pull arrangement that sources and sinks current to and from the load. Both the transistors are in common-emitter configurations, and each one has a corresponding diode connected between its collector and the load in an orientation opposite that of the collector-base junction. The diodes prevent the reverse current that would otherwise flow in response to an output overvoltage of the polarity that forward biases the collector-base junction of the transistor, and the over-voltage is thereby prevented from being seen at the operational-amplifier output terminal. Overvoltages of the other polarity are not seen because they reverse bias the base-collector junction.

Abstract: The present invention is a security monitoring system which effectively monitors a large number of areas in a cost effective manner using already existing communications infrastructure. More specifically, the method and apparatus of the present invention warns at least one security post of an undesired condition at a monitored area by sending a fax of an image of the monitored area via a phone line and/or by sending an E-mail of a color image via a global telecommunications network such as the Internet. Generally, the present invention includes a camera for creating a first image of the monitored area at a first time point and for creating a second image of the monitored area at a second time point. In addition, a data storage device stores the first image and the second image, and an image processor, coupled to the data storage device, compares the first image with the second image.