Abstract: A nuclear reactor includes an active portion with fissionable fuel and neutron moderating material surrounded by neutron reflecting material. A control element in the active portion includes a group of movable rods constructed of neutron-absorbing material. Each rod is movable with respect to the other rods to vary the absorption of neutrons and effect control over neutron flux.

Abstract: An apparatus for mounting a jibsail and a mainsail on a sloop, the structure including a step assembly bedded to the hull and supporting conventional roller and ball bearings; a mast spreading the mainsail; a generally horizontal boom located close above deck and rotating freely about the step; a forespar rotatable about its own axis and extending from high up on the mast to said boom, spreading the jibsail; and rigging connecting the jib and mainsail with said boom. The spars, sails, and cord rigging are freely rotatable on the bearings as a unit about the step as the wind deviates in direction.

Abstract: An apparatus for rotatably mounting a sail on racing yachts, sailboats and sailsleds, which includes a step adapted to be mounted on the hull of the craft, a boom, rigging connecting the sail to the boom, adapted to enable setting of the sail-to-boom orientation, and means for connecting the boom to the step so that the boom, sail and rigging are substantially freely rotatable about the step, and so that the orientation of the sail is maintained at a substantially constant angle with respect to the direction of the shifting apparent wind, to enable the sail to respond directly to shifting winds without requiring manual supervision, in order to provide maximum thrust with minimum drag for substantially increased racing yacht speed capabilities. A keel is connected to the bottom of the hull to rotate about a vertical axis through the abaft portion of the keel, in order to minimize racing yacht heeling and hydrodynamic drag.