James F. Pitts was elected corporate vice president and president of Northrup Grumman Corp.'s Electronic Systems sector, effective Oct. 1. He succeeds Robert P. Iorizzo, who is retiring. Pitts is currently vice president and general manager of the sector's aerospace systems division.    . . .    Stuart Spitzer was named vice president, materials and engineering, at Konarka Technologies Inc., a Lowell, Mass., maker of specialized photovoltaic materials used to collect solar energy.    . . .    Andrew Savadelis was appointed CFO of NanoOpto Corp., a Somerset, N.J.-based maker of modular nano-optic components. Richard E. Hegberg, senior vice president of worldwide sales at ATI Technologies, has joined NanoOpto's board of directors. Savadelis was formerly CFO, senior vice president of finance and a board member at Alfacell Corp. Previously, he held executive positions at Orchid BioSciences Inc., Stratus Photonics Inc., eMagin Corp., Anadigics Inc. and Bristol-Myers Squibb Co. Hegberg was formerly CEO of NetOctave Inc.; he has also held executive sales positions at Agere Systems Inc., Trident Semiconductor and Electronic Designs Inc.