Shamrock Technologies Inc. recently appointed Joon Choo vice president of marketing worldwide.      Mr. Choo joined Shamrock Technologies in 1983 as a development chemist. He worked in multiple roles leading to his appointments as technical director and Asian sales manager prior to his relocation to Kuala Lumpur in 1996, where he served as executive director for Shamrock Technologies Asia Inc.      Mr. Choo was repatriated to the new Dayton headquarters in 1999 to assume responsibilities a...