Disclosed are embodiments of a system for optimizing query processing in a federated information system. Also disclosed is a method of preparing the NO-releasing compounds. The knuckle includes a cylindrical opening and the pin is constructed with a central ball part and oppositely extending shanks. A motor assembly with step-down and step-up gear assemblies that provide the rotational energy to the spool assembly and the reciprocating movement to a traveling pin with a line guiding roller at its distal end.