Abstract: A process for the selective recovery of precious metals from a medium loaded with precious metals and base metals. The selective recovery of precious metals is achieved by exposing the medium to an aqueous solution containing a complex of formula MX2—, wherein M is a metal of group IB or IIB of the Periodic Table of Elements, and X is a monovalent radical. A second invention relates to the removal of copper from the medium whereby elution of copper is achieved by exposing the medium to an aqueous solution capable of oxidising Cu(I) to Cu(II) whilst not eluting precious metals from the medium.

Abstract: A method to test the erase condition of memory cells in a memory array device is achieved. The method is further extended to methods to detect and correct under erase and over erase conditions. The erase condition of a section of the memory array device is altered to form an erased section and non-erased sections. The control gates of the memory cells in the non-erased sections are forced to a normal off-state voltage sufficient to turn off erased cells. The control gates of the memory cells in non-selected subsections of the erased section are forced to a guaranteed off-state voltage that will turn off erased cells including those that are over erased. The control gates of the memory cells in a selected subsection of the erased section are forced to a check voltage. Thereafter, the bitline current of the selected subsection of the erased section is measured to determine erase condition of the selected subsection of the erase section.

Abstract: A device for storing electromagnetic energy in toroidal superconducting windings of circular right cross-section, wherein the device is constituted by a plurality of flat cylindrical coils having a plane of symmetry perpendicular to their own axes and including the axis of the torus, and which are separated by wedge-shaped spacers. The invention is applicable to distribution networks or to electrical machines.