Abstract: A centrifuge method and apparatus particularly useful for desulfurizing slurry coal, and for removing mineral impurities therefrom, so that such coal may be more economically transported in pipeline systems. A slurry of finely-divided coal and impurities is forced upwardly at a predetermined velocity into the chamber of a rotating centrifuge rotor having frusto-conical upper and lower inner surfaces disposed with their apexes meeting along an intermediate apex line. Rotational movement is imparted to the upwardly-directed stream, and coal particles (i.e., particles of lower specific gravity) follow a trajectory leading them into contact with the upper frusto-conical surface, whereas impurities (particles of greater specific gravity) follow a trajectory leading to the lower frusto-conical surface.

Abstract: A vascular prosthesis and its method of fabrication. The prosthesis takes the form of a flexible and conformable support tube having a luminal surface formed of a smooth, homogenous, and substantially non-thrombogenic hydrogel having relatively small pores or microvoids suitable for tissue ingrowth but resistant to thrombus formation, and having an outer surface formed of essentially the same hydrogel having a heterogenous microstructure which includes relatively large pores or macrovoids especially suitable for cellular ingrowth from perigraft sources and attachment sites. In one embodiment, the tubular substrate is foraminous and the inner and outer hydrogel layers merge through the interstices of the substrate to provide a unified ground substance characterized by strata having selectively different pore characteristics for promoting effective endothelialization and for reducing possibilities of thrombotic occlusion.

Abstract: The method for separating particles having mixed density and/or size, comprises dispersing the particles in a fluid stream, passing the fluid stream into a housing which causes the fluid stream to be diverted from its original direction, and capturing certain of the particles within the housing which deflect the least amount in response to the directional diversion of the fluid stream. Apparatus for accomplishing this method include a channel in which the air flow undergoes a change in direction of 90.degree., one boundary being a right angle bend and the other being formed from a circular curve or rectangular hyperbola. Another device for accomplishing the method includes an inlet channel which enlarges in diameter and which includes capturing means placed along the longitudinal axis of the inlet channel, whereby the fluid must divert radially outwardly around the capturing means as it passes from the inlet channel through the enlarged portion thereof.