Thousands of Imad Naffa's digital devotees are mourning the Sept. 6 loss of the industry social-networking pioneer whose Twitter posts seemed omnipresent. Naffa, a civil engineer, building-code software developer and entrepreneur, had a fatal heart attack in Fresno, Calif., at age 49, according to a post by Loretta Naffa, his wife and the office manager of his firm, Naffa International.Dubbed the “Twitter King” by BusinessNewsDaily.com, an online publication for startups, Naffa claimed more than 56,000 followers. He was second among construction tweeters, says Wefollow.com, a website that ranks registered Twitter users based on the number of followers and “influence.” Matt
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.