Abstract: A drilling system can comprise a drill string having a longitudinal axis and comprising at least one drill rod and a wireless sub coupled to the at least one drill rod. The wireless sub can comprise processing circuitry that is configured to detect mechanical impulses of the drill string. The processing circuitry can be configured to wirelessly transmit signals indicative of the mechanical impulses to a remote computing device.

Abstract: Access to groups of related items which are accessible by multiple processes in a computer system is controlled, in response to determining that an individually accessed data item is part of a group, by marking the whole group as locked and returning an unlocking key to the process accessing the original data item. Further access to any items of the group by a process is prevented except on provision of the key. The invention is particularly applicable to messages in a message queuing system which are logically grouped and yet may be individually destructively retrieved.

Abstract: A data processing apparatus runs a messaging and queuing software package whereby messages received at the data processing apparatus are stored in a message queue. The apparatus has: a processor; a high storage capacity storage device; and a low storage capacity storage device (e.g., a high-speed cache); the high storage capacity storage device stores full-length expiration data for each message in the message queue; and the low storage capacity storage device stores an abbreviated version of the full-length expiration data for each message in the message queue, the abbreviated version used to quickly and efficiently determine whether a queued message is expired.

Abstract: A conveyor assembly (11) for attachment to a conveyor belt boot end (10) for use in a mine. The conveyor assembly (11) includes two conveyor modules (12) and (13) which are towed by the boot end (10). The two conveyor modules (12) and (13) enable assembly of a conveyor structure (16) to support the conveyor belt (17). The conveyor structure (16) is constructed during movement of the boot end (10).

Abstract: Disclosed is a conveyor belt/cutting head advancement mechanism (10). Mechanism (10) comprises a conveyor belt support structure (11) connected at one end to a conveyor belt gathering structure (12). The conveyor belt support structure (11) is typically interconnected at its forward end to a self advancing conveyor return end (not shown). Material removed from a mine face by the cutting implement is delivered to a conveyor belt supported by the support structure (11). Structure (11) comprises a plurality of structural elements (18) pivotally interconnected in a scissor-like configuration. The mid points of elements (18) are pivotally interconnected at a point coinciding with the mounting location of a conveyor belt return roller (16). At the upper pivotally interconnected extremities of elements (18), the conveyor belt advancing rollers are supported. Mounted at a location nearby the lower ends of elements (18) are ground engaging wheels (17).