Abstract: A method for controlling command message flow in a network including a server and a client. A command window, comprising a maximum number of command messages that may be outstanding at the server, is included in messages sent from the server to the client. The value of the command window at the server is modified in accordance with available server resources for receiving command messages. When there are insufficient resources at the server to process one of the command messages delivered to the server, then a pause message is sent to the client indicating which said command message cannot be received; indicia is stored that indicates the command message initially discarded; and subsequent said command messages delivered to the server are discarded until an initially discarded said command message is again delivered to the server.

Abstract: Heavy minerals such as gold, silver, platinum, etc., along with gemstones such as diamonds, rubys, sapphires, etc., occuring in nature in the free state or having been mechanically released by crushing, screening and/or sorting into a free state, can be separated from the common material, into which they are mixed, by applying water to the mixture of materials and allow their different specific gravities to separate them into the bottom of a grooved trough. In the novel mineral concentrator described, to minimize the loss of water, a recirculating pump re-uses the same water from a reservoir repeatedly. The free minerals and gemstones settle out of the main water flow and are trapped into grooves and other pockets and crevices. Some of the pump's water flow is allowed into a feed hopper to wash down the hopper's walls, and in conjunction with shaped apertures in the hopper bottom, automatically regulate the flow of material entering the main trough or sluice.