Abstract: An album construction for holding and displaying printed folded cards comprising (a) a rectangular support having a center portion and two outer portions, said center portion being longitudinally shorter than the two outer portions and thereby forming two bounded slots at each end of the center portion; (b) an elastic cord having both ends attached to said rectangular support and being of sufficient length to encircle or wrap the center portion of the rectangular support at least twice and thereby produce a series of at least two taut elastic strands located immediately adjacent to each other whereby the fold of the printed cards may be held between one of the taut elastic cord materials and the rectangular support; and (c) an album cover having a central spine and two outer covers, said rectangular support affixed to the spine.

Abstract: A spacecraft attitude and altitude control system utilizes sets of three pulsed plasma thrusters connected to a single controller. The single controller controls the operation of each thruster in the set. The control of a set of three thrusters in the set makes it possible to provide a component of thrust along any one of three desired axes. This configuration reduces the total weight of a spacecraft since only one controller and its associated electronics is required for each set of thrusters rather than a controller for each thruster. The thrusters are positioned about the spacecraft such that the effect of the thrusters is balanced.

Abstract: There is provided heat exchange tube formed from a ductile metal strip which is formed into a generally circular configuration with the opposing longitudinal edges of the strip welded together. Both surfaces of the strip are enhanced. One surface of the tube is enhanced with protrusions in the shape of truncated cones. The ratio of the pitch between longitudinally aligned protrusions and transversely aligned protrusions maximizes the formation and maintenance of vortexes in a flowing fluid along the tube surface.