Page 18

apr16

research briefs Credit: Scott Schrage; University of Nebraska-Lincoln Communications Chris Tuan stands on the test slab of conductive concrete at the University of Nebraska-Lincoln. Connecting the conductive concrete to a low power source gives it the heat to melt away snow and ice. “There are two steel rods running lengthwise along the pavement,” Tuan says in an email. “Various power sources, ac or dc, may be applied. We have used three-phase, 208-V ac with success. You turn the power on a few hours before the storm, and turn it off when not needed.” The team is currently testing a 200-ft2 slab of its conductive concrete at the university’s campus for the Federal Aviation Administration, which may incorporate the material into future airport tarmacs. The testing runs through March 2016, according to a University of Nebraska press release. “To my surprise, they don’t want to use it for the runways,” Tuan says in the release. “What they need is the tarmac around the gated areas cleared, because they have so many carts to unload—luggage Research News service, food service, trash service, fuel service—that all need to get into those areas.” Clearing the way for service carts to access planes, especially during inclement weather, could greatly reduce travel delays in cold climates. And there’s rather good reason to think the concrete test will be a success. Tuan and his team previously completed a five-year trial of conductive concrete on the Roca Spur Bridge just south of Lincoln, in Roca, Neb. The heated bridge deck, installed in 2002, contains 52 conductive concrete slabs that have proved how effective the material solution could be in targeted places, such as on bridges. “Bridges always freeze up first, because they’re exposed to the elements on top and bottom,” Tuan says in the release. “It’s not cost-effective to build entire roadways using conductive concrete, but you can use it at certain locations where you always get ice or have potholes.” A Roca Spur Bridge project report from the Nebraska Department of Roads estimates an energy cost of just $250 to heat the bridge during a typical Nebraska winter storm—several times less than the cost of a truckload of de-icing chemicals. In addition to its clear benefits for travel and cost, heated concrete could benefit the environment and city workers, too. According to the release, “Potholes often originate from the liberal use of salt or de-icing chemicals that can corrode concrete and contaminate groundwater over time, Tuan said, making the conductive concrete an appealing alternative with lower operating and maintenance costs.” Many teams have attempted versions of conductive concrete in the past, but those attempts have failed in implementation because of high operating costs. According to a National Geographic article, the new concrete developed by Tuan and his team “uses byproducts from the coal and steel industries to reduce costs 60% compared to earlier trials.” n Faster, cheaper technique for creating cubic boron nitride promises a next-gen power grid In December 2015, scientists at North Carolina State University, including ACerS member Jay Narayan, discovered a new phase of solid carbon that is harder than diamonds and can be formed at room temperature and at ambient atmospheric pressure. Called Q-carbon, this new phase is distinct from known phases of graphite and diamond. Now Narayan and his colleagues are making news again. In addition to discovering a new phase of boron nitride called Q-BN, the scientists also have developed a new technique for creating cubic boron nitride (c-BN) at ambient temperature and pressure, a technique that could lead to advancements across many applications, including power grid technologies, according to a recent NC State news release. “This is a sequel to our Q-carbon discovery and converting Q-carbon into Ceramic firefighting foam strengthens with temperature Scientists at ITMO University (St. Petersburg, Russia), in collaboration with research company SOPOT, have developed a novel type of firefighting foam based on inorganic silica nanoparticles. The new foam beats existing analogues in fire-extinguishing capacity, thermal and mechanical stability, and biocompatibility. After the fire is extinguished, the substance actively absorbs water, softens, and falls apart into bioinert silica particles. Largescale experiments of the hardening foam showed that it can create a flame-retardant belt to stop the spread of forest fire. For more information, visit newswise.com. Low-cost yet high-precision glass nanoengraving Scientists from Moscow Institute of Physics and Technology, Institute of Chemical Physics, Moscow State University, and Institute of Problems of Chemical Physics have developed a mechanism of laser deposition of patterns on glass with a resolution of 0.001 the width of a human hair. Small glass spheres, playing the role of the lens, helped focus the laser. This mechanism allows inexpensive and relatively easy fabrication of complex patterns on a glass surface, thereby obtaining a spatial resolution of less than 100 nm. For more information, visit mipt.ru/en/news. n 16 www.ceramics.org | American Ceramic Society Bulletin, Vol. 95, No. 3


apr16
To see the actual publication please follow the link above