Abstract: In general, the present invention is directed to systems and methods of providing improved ballasted clarification systems for the treatment of water or wastewater. In accordance with some embodiments, a method may include introducing an influent including the water or wastewater and a coagulant; agitating or mixing the influent causing flocs to develop; introducing polymer and ballast wherein the ballast has an aspect ratio of less than 1.15; agitating or mixing the influent causing the ballast to move through the influent and penetrate the flocs; agitation or mixing the flocs to cause larger flocs to form through collision of smaller flocs among the flocs; providing the influent into a clarifying tank having a bottom and a top, wherein the ballast particles in flocs cause the flocs to settle to the bottom of the clarifier; and outputting an effluent from the top of the clarifying tank.

Abstract: An optic for a head mounted display having a first concave surface, a convex surface, and a second concave surface. The first concave surface receives light incident to its surface and transmits the light. The convex surface reflects light. The second concave surface reflects the light transmitted by the first concave surface and transmits the light reflected by the convex surface so that the light reflected by the convex surface travels through the second concave surface and is emitted outwardly.

Abstract: An optic for a head mounted display having a first concave surface, a convex surface, and a second concave surface. The first concave surface receives light incident to its surface and transmits the light. The convex surface reflects light. The second concave surface reflects the light transmitted by the first concave surface and transmits the light reflected by the convex surface so that the light reflected by the convex surface travels through the second concave surface and is emitted outwardly.

Abstract: In general, the present invention is directed to systems and methods of providing improved ballasted clarification systems for the treatment of water or wastewater. In accordance with some embodiments, a method may include introducing an influent including the water or wastewater and a coagulant; agitating or mixing the influent causing flocs to develop; introducing polymer and ballast wherein the ballast has an aspect ratio of less than 1.15; agitating or mixing the influent causing the ballast to move through the influent and penetrate the flocs; agitation or mixing the flocs to cause larger flocs to form through collision of smaller flocs among the flocs; providing the influent into a clarifying tank having a bottom and a top, wherein the ballast particles in flocs cause the flocs to settle to the bottom of the clarifier; and outputting an effluent from the top of the clarifying tank.

Abstract: A method of treating liquid including mixing coagulant with the liquid, introducing mixed coagulant and liquid into a primary reaction zone, containing an agitator, of a reactor which is substantially concentrically positioned with respect to a secondary reaction zone of the reactor, introducing flocculant into the primary reaction zone at a location between the agitator and where the mixed coagulant and liquid are introduced into the primary reaction zone, mixing the mixed coagulant and liquid with the flocculant and causing the resulting mixture to flow into the secondary reaction zone, introducing an encapsulating agent into the secondary reaction zone, recirculating the liquid and encapsulated flocs through the primary and secondary reaction zone, and passing the liquid and encapsulated flocs outwardly of the reactor, and an apparatus for treating liquids including a reactor, a draft tube substantially concentrically positioned within the reactor and being positioned such that the liquids may flow inwardl

Abstract: A method of treating liquid including mixing coagulant with the liquid, introducing mixed coagulant and liquid into a primary reaction zone, containing an agitator, of a reactor which is substantially concentrically positioned with respect to a secondary reaction zone of the reactor, introducing flocculant into the primary reaction zone at a location between the agitator and where the mixed coagulant and liquid are introduced into the primary reaction zone, mixing the mixed coagulant and liquid with the flocculant and causing the resulting mixture to flow into the secondary reaction zone, introducing an encapsulating agent into the secondary reaction zone, recirculating the liquid and encapsulated flocs through the primary and secondary reaction zone, and passing the liquid and encapsulated flocs outwardly of the reactor, and an apparatus for treating liquids including a reactor, a draft tube substantially concentrically positioned within the reactor and being positioned such that the liquids may flow inwardl

Abstract: A mobile friction welding machine is provided for creating friction weld joints in workpieces such as metal sheets, especially lead sheets is described. The machine has a track assembly to guide it across work pieces, including a caterpillar track system on the machine. The friction welding is achieved by rotating a probe and applying a downward load on the probe to urge it into the work process. The probe is preferably a pair of spaced apart probes having a crescent-shaped cross-section.

Abstract: A method of operating on a workpiece comprises offering a probe of material harder than the workpiece material to a continuous surface of the workpiece causing relative cyclic movement between the probe and the workpiece while urging the probe and workpiece together whereby frictional heat is generated as the probe enters the workpiece so as to create a plasticized region in the workpiece material around the probe, stopping the relative cyclic movement, and allowing the plasticized material to solidify around the probe. This technique, which we refer to as "friction plunge welding" provides a very simple method of joining a probe to a workpiece. The method can be used for repairing cracks and the like within a workpiece or for joining members, such as studs or bushes, to a workpiece.