Abstract: Complete drive system, called motor-drive unit, for use in remote locations with limited radial space like downhole, narrow tunnels, pipelines and other applications with similar conditions. Given the spatial limitations the unit must have elongated shape. It includes a number of motors connected mechanically in series and a lower number of inverters, driving groups of the motors so that load is equally distributed along axis of the unit. Motors within each group can be electrically connected in series or in parallel. The motor-drive unit is supposed to be fed by DC voltage via a cable with length up to several km; therefore, it includes a buck converter for stabilization of voltage inside the unit and a power-line communication module to be controllable from the surface.

Abstract: Complete drive system, called motor-drive unit, for use in remote locations with limited radial space like downhole, narrow tunnels, pipelines and other applications with similar conditions. Given the spatial limitations the unit must have elongated shape. It includes a number of motors connected mechanically in series and a lower number of inverters, driving groups of the motors so that load is equally distributed along axis of the unit. Motors within each group can be electrically connected in series or in parallel. The motor-drive unit is supposed to be fed by DC voltage via a cable with length up to several km; therefore, it includes a buck converter for stabilization of voltage inside the unit and a power-line communication module to be controllable from the surface.

Abstract: A multiple region convolver includes tapering between successive models of a physical system. The tapering is performed during a transition period.

Abstract: A collection of playing pieces for a vocabulary word game is disclosed. The pieces contain on one face a multi-letter combination of at least two letters plus a designator indicating required location of the letter combination in words. During a playing interval one playing piece is displayed to all players. Each player writes a list of words containing the selected letter combination at the designated location in the words. After a predetermined time limit the players reveal their list to all. The winner of the playing interval is the player with the greatest number of words on their list. The game continues for a chosen number of intervals, the game winner being the player winning the greatest number of individual playing intervals.

Abstract: A multiple region convolver includes tapering between successive models of a physical system. The tapering is performed during a transition period.