Abstract: A life safety system with a micro-controller that is programmed to operate both a visual signal and an audible signal. One feature of the system is that a user is permitted to enter a temporal signaling mode for not only the audible signal, but also the visual signal. The program includes an energy saving routine that operates the visual signal in the temporal mode with an energy consumption that is substantially smaller than required for operation in a continuous mode. The temporal pattern has four cycles with one flash pulse per cycle for the first three cycles and no flash pulse for the fourth cycle.

Abstract: The present invention provides a device and method for locking a knife gate valve in a position, such as an open and/or closed position. The locking device has a pair of first posts disposed substantially parallel to the shaft. A swivel lock member is mounted to rotate substantially about the axis of the shaft and to reciprocate together with the shaft and the knife. The swivel lock member is selectively rotatable between an unlocked position at which the swivel lock member does not engage the first engageable portions and a locked position at which the swivel lock member engages both of the first engageable portions to prevent the swivel lock member from movement in at least one of the back and forth directions along the axis of the shaft.

Abstract: A slotted coaxial antenna design that accomplishes simultaneous DTV and NTSC broadcast with minimal tower wind loading, is disclosed. In a preferred embodiment, the antenna design comprises a VHF slotted coaxial antenna that acts as a framework to house multiple UHF slotted coaxial antennas. The one or more UHF slotted coaxial antennas, which each acts as an UHF outer conductor, and one or more VHF couplers, that surrounds the VHF inner conductor, configures an arrangement such that the UHF antennas and VHF couplers share a common aperture; namely, the VHF antenna. This antenna design allows for high band VHF/UHF broadcast of DTV and NTSC signals while being easily adaptable to existing slotted coaxial antennas.

Abstract: A switchable directional coupler in which a three position switch partitions the coupler into three distinct coupling paths among its four ports according to the status of a pair of quadrature phase input signals of amplitudes A and B. In one position with both input signals being active, the output signal has an amplitude of A+B. In a second position with only the input signal of amplitude A being active, the output signal has an amplitude of A. In the third position with only the input signal of amplitude B being active, the output signal has an amplitude of B.

Abstract: A tower support structure for supporting communications equipment or other types of equipment above the ground is provided. The structure includes a foundation, a tower having a number of tower sections is supported by the foundation. The tower includes main bracing systems and sub-bracing systems extending between the tower columns. A cable support structure is anchored to the ground and is also connected to the tower.

Abstract: A bulk material feeder for improving material flow as the material makes the generally ninety degree (90°) transition from the downcomer to the generally horizontal conveyor. The downcomer presents an innermost divergent surface that extends upwardly from the discharge opening of the downcomer. The divergent surface may be defined by an inlet wall that is fit within the outer casing wall of the downcomer, or by the outer casing wall itself. The present invention also concerns the method of retrofitting an existing feeder with a divergent inlet.

Abstract: An axial flow mixer impeller which is high in efficiency in terms of flow is made more effective, when used in a sparging system for dispersion and for mass transfer of a liquid phase or a gaseous phase into a liquid which is being mixed or agitated, by forming a shear field which breaks the phase being dispersed into fine bubbles which are dispersed by the impeller. This is accomplished without a major effect on the high flow efficiency of the axial flow impeller. To this end a structure which forms a Venturi is located on the side or sides of the blade where the phase (bubbles of fluid of different density or viscosity which are to be mixed or dispersed by the impeller) occurs, in the high velocity region near the tip of the blade. This Venturi creates a high shear field which breaks up the bubbles and disperses them as fine bubbles as they leave the impeller. The structure may be provided by a pair of proplets in the vicinity of the tip end of the blade which form a wedge shaped flow path therebetween.

Abstract: A slotted coaxial antenna design that accomplishes four-way branch feeding without the use of feedlines, is disclosed. In a preferred embodiment, the antenna design is based on a number of layered coaxial feeds where each layer feeds the next outer layer. The internally branch fed slotted coaxial antenna design produces substantially no beam sway over at least four television channels, can accommodate pressurizing for increased power handling, and provides desirable antenna output response performance suitable for digital TV transmission and NTSC antenna systems.

Abstract: A multi-layered slotted antenna with reduced susceptance and increased conductance with a minimal effect on antenna radiation in the azimuth. Separate conductors are connected across the individual slots to reduce the slot susceptance with a minimal effect on slot radiation.

Abstract: A biochemical oxidation system and process is disclosed for the removal of insoluble sulfides from metal ores. A liquid mixture of an ore slurry and of a liquid biochemical oxidation medium is flowed through a plurality of covered overflow tanks connected in series. The liquid mixture is continuously aerated in an aeration chamber formed in the tanks with a mixture of a purified oxygen gas and a purified carbon dioxide gas as introduced into the aeration chamber. A substantially sulfide-free liquid mixture is discharged from a last tank into a clarifier in which at least a portion of the biochemical oxidation medium is separated from the liquid mixture for recirculation into the tanks.

Abstract: An axial flow mixing impeller system for efficient mass transfer by control of size of the bubbles of the fluid which is being dispersed, especially gases and liquids with viscosities greater than the liquid into which dispersion occurs, is obtained by creating passageways through the impeller blades for flow between the suction and pressure sides of the blades which disrupts the flow over the suction sides of the blades thereby reducing the tendency for bubbles to grow or coalesce into large bubbles which instead of being dispersed, rise to the surface without effective mass transfer to the liquid which is pumped by the impeller. The blades of the impeller may be slotted inwardly from the tips thereof to provide the passageways or may be formed from segments, gaps between which provide the flow passageways.

Abstract: A system controls the diameter of both a neck region and a full diameter region of a monocrystalline rod being pulled from molten material held in a crucible. The system uses a video camera viewing light reflected from a meniscus around the rod where the rod emerges from a melt surface of the molten material. The video camera has a zoom lens for enlarging an image of the meniscus during growth of the neck of the rod and for reducing an image of the meniscus during growth of a full diameter body of the rod. A computer controlling a pull rate for the neck growth of the rod is rapidly responsive to a count of total camera pixels illuminated by the image of the meniscus during neck growth.

Abstract: A mixing system utilizes up pumping impellers which entrain gas into the liquid both at the surface (the gas liquid interface) and below the surface by induction to draw gas down below the surface where it is dispersed into the circulation produced by the impellers. The impellers are the axial flow type. Tubes disposed on the suction sides of the impeller blades, and providing gas outlets near the tips of the blades, rotate with the impellers. The tubes may extend along the shaft above the surface or into a hollow shaft having a breathing opening above the surface. The rotation of the impeller produces a suction at the tube outlets to draw gas into the liquid while the upward circulation produces surface turbulence for gas entrainment. The entrained gas from the surface and the gas discharged from the tubes is circulated.

Abstract: In order to sparge gas into a liquid or liquid suspension in a tank wherein a principally axial flow pattern downwardly towards the bottom of the tank and then upwardly along the side wall of the tank returning axially downward is established by an axial flow impeller, a disc of a diameter less than the diameter of the impeller is spaced axially therefrom in the direction of the outlet flow towards the bottom of the tank from the impeller so as to turn the axial flow, radially, thereby establishing a pressure gradient which prevents the collection of gas released by a sparge between the disc and the bottom of the tank and flooding of the impeller. The gas is released in the axial flow from the tip region of the impeller thereby facilitating the shearing of the gas into fine bubbles promoting mass transfer of the gaseous phase into the liquid phase in the tank. Since flooding is inhibited, as much as six times the volume of gas (gas rate) can be handled as may be the case without the disc.

Abstract: A digital signal, beam radiation antenna consisting of a cylindrical mast having an inner tubular conductor and an outer tubular conductor, and means for exciting said inner conductor to establish a traveling wave internal to said antenna. Moreover, there are spaced slots in said outer conductor defining an illumination aperture coupled to the inner conductor and for radiating the beam from the antenna. This establishes the illumination along the aperture so as to produce a high beam tilt of the order of 0.6-3.5 degrees from the horizontal for the beam radiation; further, for varying the phase from layer to layer, such that there are substantially no null variations in the elevation pattern of the beam.

Abstract: A mixing system in a tank provides a flotation cell for froth collection of minerals such as metallic ores thereby separating such ores from other materials with which they are mined and enabling a concentrated ore component to be collected. The mixing system maintains particles containing the ores in a circulating liquid suspension in a contact zone where bubbles are discharged. Ore particles are attracted and attached to the bubbles. The bubbles rise and float to the top of the liquid for collection of the concentrated ores. The mixing system includes a radial flow impeller and an axial flow impeller which are attached for rotation on a common shaft, with the axial flow impeller below the radial flow impeller. The radial flow impeller is disposed in a space between a disc, which rotates with the radial flow impeller and another disc which is stationary, and may be a flange of a pipe around the shaft and extending above the surface of the liquid.

Abstract: Mixer apparatus having an impeller on a shaft, which circulates a body of liquid the surface of which can clear the impeller, especially when the liquid is in a tank, and the tank is drained, is protected against excessive by use of a flexural member, which may be in the form of radially opposed pairs of resilient plates, which extend from the shaft and are attached thereto by a collar. As the liquid surface drops below the impeller, the members present surfaces to the liquid in the tank on which forces are opposing the oscillation are developed by interaction of the surfaces with the liquid in the tank. Restoring forces on the shaft due to the flexing of the resilient plates also reduce the shaft oscillation. The stiffness of the plates is selected to optimize the restoring forces for the mixing apparatus which is stabilized.

Abstract: A method of and system for determining the melt-level in a crystal growing system. A rangefinder emits a signal to reflect off the melt. The reflected signal is directed to a retroreflector. The retroreflector redirects the signal along a parallel path back to the melt surface. The redirected signal is reflected off the melt surface back to the rangefinder, where it is analyzed to determine the distance traveled by the signal. From this, changes in melt-level are determined and the melt-level may be appropriately controlled.

Abstract: An integral oil filter-pump system for an electric power device which involves a cabinet having an oil-filled compartment for containing the power device, as well as a circulation pump for circulating oil through the system, including the compartment for containing the power device.