Abstract: The present disclosure relates to a fracturing propping agent and a preparation method thereof. The fracturing propping agent comprises the following raw materials: dry sludge, quartz sand, coal ash, bauxite and clay.

Abstract: The present disclosure relates to a fracturing propping agent and a preparation method thereof. The fracturing propping agent comprises the following raw materials: dry sludge, quartz sand, coal ash, bauxite and clay.

Abstract: Systems and methods for connecting a plurality (even a large plurality) of recipients or destinations to an originating caller across, for example, a phone network. In preferred embodiments, the phones are connected within a single private branch exchange (PBX), which can be distributed across individual nodes over large distances. The size of the groups included in the destinations can be indefinitely large and can be configured to parse recipients as desired. In preferred embodiments, an originator selects from among various pre-defined groups (or, alternatively, the originator defines new groups) and initiates a one-way or two-way call to recipients. The recipients' control over refusing the announcement are optional, but preferably include non-override options so that emergency announcements may not be ignored or blocked.