Abstract: A method of separating non-magnetic particles of different densities by using a ferrofluid to produce levitation wherein compensation is made for the magnetic attraction or interaction of the particles by removing particles too small for the desired sharpness of separation or by maintaining the ratio of the interaction force to the separation force outside of theoretical limits.

Abstract: A metal layer is clad to a metal substrate by laying spaced rods or wires of a cladding metal on the substrate surface and scanning the cladding metal with a continuously operating laser beam, part of which impinges directly on the cladding metal to melt it and part of which impinges on the adjacent surface area of the substrate to improve flow of molten metal thereon. The cladding metal may be fed to the substrate surface in synchronism with laser beam scanning. The process produces a clad layer of the cladding metal on the substrate characterized by a fine and homogeneous structure within the clad on layer and further characterized by uniform and high hardness compared to prior art cladding methods. The surface of the clad may be smoothed by locally oscillating the laser beam during the course of cladding and/or by multiple passes.

Abstract: A method of separating small diameter non-magnetic particles of different densities by using a low magnetic saturation ferrofluid and a high magnetic gradient to produce levitation by overcoming the magnetic attraction of the particles.Application of a constant gradient field of a level below the magnetic saturation level of the ferrofluid forms the ferrofluid into a density gradient column. Each non-magnetic particle levitates to the level inside the ferrofluid having the same apparent density as the particle.The ferrofluid contains magnetic particles with a mean effective core diameter less than about 50 angstroms and a stabilizing agent layer on the particle exceeding about 50 angstroms. Perfluorinated carriers and surfactants are preferred for their relatively high intrinsic density.

Abstract: Herein disclosed is a pulse width decoder comprising an oscillator activated to generate clock pulses of relatively short duration as long as an input signal pulse is applied, a shift register adapted to channelize a multiplicity of pulse widths, means including a divider counter for utilizing locally generated pulses to shift the register, and means including feedback circuitry from the shift register to the divider counter to change the divisor in the counter so that the range of window tolerance provided by the channelizing is effectively increased, in steps, with ascending groups of pulse widths. Additionally, delay means is incorporated to provide for a minimum limit of acceptable input signal pulse width.

Abstract: A laser mirror resistant to thermal distortions produced by radiative heating and/or heating by other processes associated with high power CW lasers. A plurality of rods connect a flexible face portion to a stiff base portion to define an "elastic" arrangement which permits free lateral expansion but resists if not prevents distortion in the form of bending of the face portion. The face portion may be formed1. from a block of heat conductive material which has been deeply slotted from its rear end to define an effectively thin face portion attached to a middle portion of high heat capacity, or2. from a thin plate of heat conductive material cooled from the rear face by either forced convection to, or by nucleate boiling of, a flowing heat transfer media in the middle portion.

Abstract: A two-stage diffuser is disclosed which is intended to be used with a high pressure ratio centrifugal compressor. The first stage comprises a vaneless diffuser passage having rotating sidewalls that freely turn on bearings mounted coaxially with the compressor rotor. The second stage comprises a stationary vaned-type diffuser. In combination, the two stages provide a compact diffuser having improved efficiency. Gas flow leaving the compressor from the periphery of the impeller at supersonic speed contacts the moving sidewalls of the rotary diffuser stage. By having these walls travel at nearly half the speed of the impeller, relative difference in speed between the gas and the walls is subsonic, hence, no shock wave occurs. Expansion of the gas in the first rotary diffuser stage makes it possible to deliver subsonic gas to the vaned second stage.

Abstract: An MHD generator includes external electrical connectors between adjacent discrete electrodes in one wall of the generator duct, which has opposed electrodes which may lie in a plane at an angle to the direction of gas flow. The electrical connection includes a circuit which adjusts the voltage between the connected adjacent electrodes to insure that the Hall voltage differential between the discrete electrodes which are adjacent to each other in the same wall of the duct does not exceed the damaging breakdown voltage. Indicator means when coupled to the circuits in accordance with the invention comprise diagnostic means which provide a graphic representation of voltage distribution along the length of the generator duct.

Abstract: An MHD generator includes external electrical connectors between pairs of the discrete electrodes in opposite walls of the generator duct, which may lie in a plane at an angle to the direction of gas flow. The electrical connection includes a passive or an active circuit which controls current flow between the connected electrodes to insure that uniform current flow along the length of the duct and that excessive current flow through such discrete electrodes in opposite walls of the duct do not exceed a damaging limit which may otherwise occur. Indicator means when coupled to the circuits in accordance with the invention comprise diagnostic means which provide a graphic representation of current distribution along the length of the generator duct.