Abstract: A content navigation/discovery system is provided. A computer is linked to a library of information objects, and includes a content navigation/discovery utility that includes both a global content discovery utility that is made available to a plurality of users to navigate/discover a plurality of information objects using one or more content filters presented in a content navigation/discovery interface, and a private or semi-private content discovery utility that is made available to one or more selected users for a selected group of users. The global content discovery utility and the private or semi-private content discovery tool are integrated so as to support user workflows that allow one or more users to selectively interact with content through the global content discovery utility and/or the primate or semi-private content discovery utility, and configured to promote emergent and collaborative learning. Related computer implemented methods are also provided.

Abstract: A battery heating system comprises a number of storage batteries and an alternator driven by a variable speed prime mover connected to supply AC heating current to the batteries. The system is arranged so that the AC current is substantially constant over the working speed range of the prime mover.

Abstract: A battery heating circuit comprising a transformer having a primary winding for connection to an a.c. supply and a secondary winding, and at least two pairs of batteries. The two batteries of each pair are connected in series and the series combinations of the pairs of batteries are connected in parallel between d.c. terminals. The secondary winding is connected between the common terminals of each pair of batteries.