Substrate or starting compounds having at least one active hydrogen may be reacted with one or more alkylene oxide in a ketone solvent at reduced temperatures compared with conventional, molten methods to give an adduct product having reduced color. The interface receives a content search request. The contention locking scheme is configured to set a light object lock on an initially unlocked object when a first thread attempts to lock the object, and to maintain a light lock on the object when a nested intra-thread lock is attempted by the first thread.