Abstract: The present invention relates to a process for making glass by the sol-gel process. A mixture of silicon alkoxide, at least two other metal alkoxides, and alcohol in a solution sufficiently acidic to hydrolyze partially the silicon alkoxide is formed. Water is then added under agitation to convert the metal alkoxides to a network of corresponding metal oxides suitable for gelation. The mixture containing the network of metal oxides is then molded for a sufficient time to form a gel. Substantially only oxides of one of the at least two other metals is then removed from the gel, which is then fixed in a liquid capable of arresting such additional removal. The fixed gel is then dried and sintered to form a glass. The step of removing the at least one other metal oxide from the gel can be followed with a step of withdrawing partially oxides of one of the remaining at least two other metals in order to form a transparent gradient-index glass after sintering.

Abstract: An apparatus for controlling operation of a railcar discharge gate assembly including a frame defining a discharge opening with a gate slidably arranged on the frame for movement along a predetermined path of travel between open and closed positions. The apparatus of the present invention includes an operating shaft rotatably supported on the frame for selectively moving the gate between open and closed positions in response to rotation of the shaft. A lock assembly is carried on the frame and is operably coupled to the operating shaft. The lock assembly includes a displacable stop member which, when the gate is closed, extends into the path of travel of the gate to prevent movement of the gate relative to the frame, and which moves in timed relation relative to movement of the gate such that upon rotation of the operating shaft to move the gate to an open position the stop member is automatically removed from the path of travel of the gate prior to movement of the gate toward an open position.