WASHINGTON ?EUR??,,????'??? Bio-based products from soybeans, palm and sunflowers have gained momentum as the United States tries to cut fuel emissions and trim dependence on oil suppliers as Iraq. A team of scientists from the U.S. Department of Agriculture is looking at altering the chemical structure of vegetable oil. Alterations could make molecules more resistant to temperature changes and would not harm topsoil or water supplies. Caterpillar and Deere & Company and Alcoa plan to test the new fluid.