Abstract: The present invention relates to a separator for use in alkaline secondary zinc cells and for use in electrochemical systems where permeation of hydroxyl ions is desired and where permeation of zincate ions is to be inhibited, comprising an inert support to which there is applied a layer comprising a polymeric binder and a carbonate or hydroxycarbonate of nickel, cerium, lanthanum, magnesium or calcium, or a mixture of any of these or which comprises a self-supporting structure of such polymeric binder or matrix-forming material and such carbonate or hydroxycarbonate. There may be incorporated in such separator electrocatalysts and fillers or surface extenders. The invention also relates to the process of production of such membranes.

Abstract: Light coupling means interposed between the photosensitive surfaces of an array of photodetectors and a scintillation crystal has a recess associated with at least one of the photodetectors, the recess being located in the light coupling means within the volumetric projection of the photosensitive surface of said at least one of the photodetectors. The recess is filled with material having an index of refraction different from the index of refraction of the light coupling means such that the index, throughout the recess, is uniform. The provision of the material with a different index in the recess serves to alter the direction of light from a light event in the crystal as the light passes through the light coupling means thereby modifying the relative amount of light received by each of the photodetectors of the array, and thereby improving spatial linearity, uniformity and resolution.

Abstract: The invention relates to a secondary cell having zinc electrodes in which there is provided an auxiliary electrode having a surface of electrocatalyst having a low overvoltage for hydrogen evolution, which is resistant to deposition of zinc thereon, means for connecting said auxiliary electrode to the negative electrodes during charging, the arrangement being such that the auxiliary electrode takes up the excessive current at the negative electrodes over that of the positive ones, thus eliminating or substantially reducing shape-change phenomena of the negative electrodes.

Abstract: Radiation imaging apparatus includes a scintillation crystal responsive to radiation stimuli for producing light events, and a plurality of photodetectors arranged in a predetermined array relative to the crystal, each of the photodetectors having a light-sensitive surface facing the crystal and being responsive to a light event for producing an output signal. Coupling means associated with each photodetector applies its output signal to coordinate computing circuitry which computes the coordinates of a light event from signals applied thereto.In one embodiment of the invention, at least one of the coupling means includes a threshold linear gate for applying the output of the photodetector with which the coupling means is associated, to the coordinate computation circuitry only if the input to this particular photodetector exceeds a predetermined threshold.

Abstract: Coordinates of a light event, computed by signal processing equipment from output signals developed by an array of photodetectors of radiation imaging apparatus in response to the interaction of a radiation stimulus with a scintillation crystal, are validated only if a representation of the total energy of the light event lies within an energy window functionally related to the coordinates of the light event. In this manner, only desirable radiation stimuli interacting with the crystal are detected, and undesirable, indirect or scattered radiation stimuli interacting with the crystal are discriminated against.

Abstract: A scintillation camera has a planar scintillating crystal that produces light events whose spatial distribution corresponds to the spatial distribution of the radiation stimuli causing such events, and a plurality of photomultipliers having photocathodes for receiving light from the crystal through a planar face thereof. Computing circuitry coupled to the photomultipliers computes the projection of a light event in the crystal on a reference axis by forming an analytical function of the outputs of the photomultipliers according to the spatial location of the light event in the crystal.