The Long Beach Board of Harbor Commissioners gave preliminary approval to fund a long-term test of a “sock on a stack” air quality improvement system for ships. The technology has shown promising results in previous demonstrations. Developed by Rancho Dominguez-based Advanced Cleanup Technologies Inc., the system uses a crane to place a large bonnet-like device over a ship’s smokestack. The exhaust from the ship’s diesel engines is then captured and scrubbed of harmful air pollutants before being released back into the atmosphere. In tests conducted in summer 2008 at the Port, the Advanced Maritime Emissions Control System, or AMECS, captured about 95 percent of nitrous oxide, sulfur oxide and particulate matter – the major pollutants in a ship’s emissions.