Photo courtesy of Poet Poet Design and Construction crews construct a new weigh station at Poet's Liberty Project in Iowa. As the U.S. Depts. of Energy and Agriculture pony up grants and loans to help fund new research and refineries to turn woody waste into cellulosic ethanol, private-sector companies are building the first commercial-scale cellulosic refineries in the nation and promoting their chemical processes for easy conversion from waste to sugar to fuel.With more than a half-dozen cellulosic plants in development in the U.S., federal officials and private companies hope to prove wrong a recent report from the National Research
Arch dams, classically curved monoliths situated in narrow valleys, are not as common as other types of dams, such as embankment dams and gravity dams. ENR takes a look at some of the biggest arch dams in the world, both completed and under construction.