We have scheduled a shut down of cleanroom operations for 48 hours to complete a 6 month preventive maintenance procedure. We plan to shutdown cleanroom operations on Tuesday (1-May-07) at 7:00 AM and plan to be completed by Wednesday (2-May-07) at 5:00 PM. Maintenance is required for our cleanroom makeup air handlers, chemical exhaust, and ultra pure water systems. Please note that the ultra pure water will be shut down for the entire building. We will also complete cleanroom troubleshooting to improve temperature repeatability during this time. Since the chemical exhaust system will be shut down please remove chemicals from all hoods in the cleanroom prior to the shutdown. If not lab staff will dispose of them for you. Thank you for your understanding and patience during this necessary procedure. If you have any questions or concerns please contact me. Regards, Mark Voorhis Building Manager Purdue University Birck Nanotechnology Center Ph: 765-494-3036