An apparatus is provided to enable a handicapped person to sit without restraints on the torso and arms. For a given transmission slot or other transmission interval, a maximum-rate user is identified from among a set of users requesting data transmissions, and a data transmission of the maximum-rate user is scheduled for the given interval. The plug has a lower coefficient of thermal expansion so that the plug area has less compressive stresses in the repaired area. A plurality of bet requests for wagering on at least one betting product may be received from the at least one user. and led through the exhaust air channel to a gas sensor where a determination is made whether the carrier gas contains amounts of tracer gas.