Abstract: Process and apparatus for enhancing the erosive intensity of a high velocity liquid jet when the jet is impacted against a surface for cutting, cleaning, drilling or otherwise acting on the surface. A preferred method comprises the steps of forming a high velocity liquid jet, oscillating the velocity of the jet at a preferred Strouhal number, and impinging the pulsed jet against a solid surface to be eroded. Typically the liquid jet is pulsed by oscillating the velocity of the jet mechanically or by hydrodynamic and acoustic interactions. The invention may be applied to enhance cavitation erosion in a cavitating liquid jet, or to modulate the velocity of a liquid jet exiting in a gas, causing it to form into discrete slugs, thereby producing an intermittent percussive effect.

Abstract: Process and apparatus for enhancing the erosive intensity of a high velocity liquid jet when the jet is impacted against a surface for cutting, cleaning, drilling or otherwise acting on the surface. A preferred method comprises the steps of forming a high velocity liquid jet, oscillating the velocity of the jet at a preferred Strouhal number, and impinging the pulsed jet against a solid surface to be eroded. Typically the liquid jet is pulsed by oscillating the velocity of the jet mechanically or by hydrodynamic and acoustic interactions. The invention may be applied to enhance cavitation erosion in a cavitating liquid jet, or to modulate the velocity of a liquid jet exiting in a gas, causing it to form into discrete slugs, thereby producing an intermittent percussive effect.

Abstract: An improved rotational buoyant mass for wave energy conversion apparatus is disclosed. The rotational buoyant mass comprises at least one pair of helical volumes mounted for rotation about a common axis. The helical volumes are rotationally displaced with respect to one another about the common axis. The improved rotational buoyant mass may include multiple pairs of helices, the helices of respective pairs being displaced with respect to one another.

Abstract: A drill bit and a method for deep-hole drilling in which the drill bit has mechanical cutting means located on its lower cutting face for cutting a solid surface upon rotation of the bit and a plurality of cavitating liquid jet nozzles spaced around the face of the bit to assist in the drilling action, the nozzles being located so as to discharge a plurality of downwardly directed and concentric liquid jets that cavitate to fracture the surface to be drilled in a series of non-overlapping slots as the bit is rotated.

Abstract: A method for increasing the cross-flow microfiltration fluxes of waste waters containing suspended solids and/or emulsified oil through microporous thermoplastic tubes by including therein a calcium compound selected from Ca(OH).sub.2 or CaSO.sub.4. The calcium compound is present in the waste waters in an amount ranging from above the solubility limit of the compound to about forty (40) percent by weight of the waste waters. The Ca(OH).sub.2 can be added directly to the waste water. The CaSO.sub.4 can be included by reacting H.sub.2 SO.sub.4 and Ca(OH).sub.2 in the waste waters to form CaSO.sub.4 in situ. Alternatively, wet CaSO.sub.4 can be formed by reacting H.sub.2 SO.sub.4 with Ca(OH).sub.2 outside the water and then added to to the waste waters in the required amount.

Abstract: A drill bit and a method for deep-hole drilling in which the drill bit has mechanical cutting means located on its lower cutting face for cutting a solid surface upon rotation of the bit and a plurality of cavitating liquid jet nozzles spaced around the face of the bit to assist in the drilling action, the nozzles being located so as to discharge a plurality of downwardly directed and concentric liquid jets that cavitate to fracture the surface to be drilled in a series of non-overlapping slots as the bit is rotated.

Abstract: Oil-water separation apparatus having a flow-through chamber containing a block of foam filter material regenerable by squeezing, a pair of perforated end plates located on either side of the foam block within the chamber at least one of which responds to applied pressure to squeeze the foam, and a flexible envelope of impervious material surrounding the foam block between the block and the inside walls of the chamber and connected at each end to the plates to avoid channeling and friction between the foam block and the walls of the chamber.