ORANGE COUNTY

Irvin J. Ella has been named senior vice president of marketing for McDonnell Douglas Computer Systems Co. of Newport Beach. Ella, formerly senior vice president of research and development at the company’s United Kingdom facility, will move to the U.S. to assume the new marketing position. Ella, a native of Great Britain, will be responsible for the company’s product planning, marketing, business development and external communications, according to Gary Liebl, president and chief executive of the Newport Beach-based company. McDonnell Douglas Computer Systems recently changed its name from Microdata Corp.

Lou Purmont, founder of United States Filter Corp., has joined Ultrasystems Inc. of Irvine as special assistant to the president, Philip Stevens. Purmont will deal with the investment community and be responsible for special projects. In 1953, Purmont founded United States Filter, which grew to be a $1 billion-plus environmental control and engineering company. It was sold to Ashland Oil Corp. in 1981.

The company also named Dianne Seeber Nelson manager of corporate communications. Nelson was formerly manager of financial communications for Lincoln National Corp. of Fort Wayne, Ind., a $12-billion financial services company. Y.T. Du has been promoted to senior vice president and controller. Du joined the company in 1982 as controller and is the chief accounting officer for the company. Ultrasytems is an engineering and construction company involved in a wide range of high technology and alternative energy projects.

Jeffrey L. Nichols has been promoted to vice president, director of marketing at Business Properties Development Co. of Irvine. Nichols will oversee the marketing and leasing of the company’s office project developments.