Heterocyclic compounds and methods of making them and using them. A control circuit controls operation of the solid state switches. Microfibrillated films of the invention find use as tape backings, filters for particulate contaminants, such as face masks and water or air filters, fibrous mats, such as those used for removal of oil from water and those used as wipes, and thermal and acoustical insulation. The presentation invention, though, provides an efficient method to identify interested subscribers for each XML document by indexing queries utilizing a graphical structure of nodes. A housing at least partially encompassing the motor and the switch has an apical end at which the motor is located.