RESUMEN
The observed increase of superconducting transition temperature (T(c)) with the number of copper oxide planes continues in the four-[CuO(2)](-2) layer (single TI layer) oxide superconductor, which has been prepared with > 80% purity and was magnetically aligned for crystallographic identification. A master scaling curve is proposed, which ties together the T(c)'s of virtually all known Bi and Tl oxide superconductors, and shows that the Tl(Bi) layers play an essential role in the superconductivity. publication 350 of the Barnett Institute.
RESUMEN
A new system for physically recording serial numbers on individual items is proposed. Each serial number is converted to a unique array of points, and this array is recorded on the item by drilling a set of holes having the arrangement of the array into the item. Laser drilling can be used to produce holes of small diameter for the array. The identifying marks extend into the item and cannot be readily removed as surface stampings. In some cases the serial number can be marked in a critical area, so that its removal would destroy the usefulness of the item. This system is particularly suitable for the marking of firearms.
