Abstract: A device for treating human blood prior to its return to a living human body. The blood filter employs a bed of fibers between about 1 and 100 microns in diameter, the outer surface of which is formed of impermeable carbon. Suitable fibrous substrates may be coated with vapor-deposited pyrolytic carbon, and the fibers may be supported between upper and lower screens which are likewise coated.

Abstract: A method and apparatus are described for measuring anisotropy in the reflectivity within a region of a surface. The apparatus basically comprises a polarizing microscope which employs a rotating half-wave plate which rotates the polarization direction of the light incident upon the surface being examined and which also rotates the polarization direction of the light reflected from the surface being examined. The intensity of the reflected light passing through a polarizing filter is detected and related to the anisotropy.

Abstract: A dental prothesis for permanent or prolonged implantation in a jawbone of a living body comprising a carbon root having specified properties including a modulus of elasticity of about 4.times.10.sup.6 psi, and an adherent, porous polymeric coating having specified properties and which is adapted to interface with bone.

Abstract: A pyrolytic carbon-coated article having improved wear resistance as a result of providing a thin wear-resistant layer just below the outer surface. The layer contains an alloy of pyrolytic carbon and a metal or metalloid carbide and is made by changing the composition in a deposition region without halting deposition so as to create transition regions adjacent the layer which include gradually lesser amounts of the alloying carbide.

Abstract: Apparatus is described for producing microspherical particles. Also described is a method for operating said apparatus. A droplet generator dispenses uniform spherical droplets into a gelling column which is sealed at both ends to prevent entry of air thereinto. A gelling liquid and a gelling gas are provided in the column, and a further gas, which is of a density lower than that of the gelling gas, is introduced to the region above the gelling gas. At the interface between the gelling gas and the further gas, the gases are withdrawn from the gelling column.

Abstract: A biocompatible prosthetic device comprising a metal alloy substrate, an intermediate layer of a high-temperature polymer which is strongly bonded thereto, and an exterior coating of dense vapor-deposited carbon. The carbon layer is thromboresistant and strongly adheres to the intermediate layer which in turn strongly adheres to the metal alloy. The polymer may be the reaction product of pyromelletic dianhydride and a diaminodiphenyl ether, and the carbon may be deposited under high vacuum conditions from a suitably heated carbon source, e.g., by ion-plating or vacuum vapor deposition.

Abstract: A method of making refractory carbide particles, which method comprises heating a granule containing refractory metal and carbon to a sufficient temperature to form a molten droplet of refractory carbide, carbon being included in said droplet in excess of the stoichiometric amount which combines with the refractory metal in the highest usual valence thereof, and cooling said molten droplet below the eutectic temperature within 60 seconds or less to cause a thin continuous layer of highly crystalline carbon to precipitate out on the outer surface thereof.

Abstract: Apparatus is described for welding a tube to a tube sheet in which the angular relationship of a weld torch supported in a rotor may be adjusted with respect to the rotor axis by changing or rotating a bushing in which the weld torch is supported in the rotor. The distance of the weld electrode from the axis of rotation of the rotor may also be separately adjusted.

Abstract: A noise generator system is described in which the amplitude of a noise source is stabilized by a feedback loop to an automatic gain control circuit, and wherein the output of the system is time controlled by means of a differential pair amplifier.