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School of Engineering's Young Investigators
breaking new ground
March 8, 1999
n January 1995, the activity in Hartford and Storrs was intense. UConn officials were at the state capitol, trying to persuade legislators that UConn 2000 would transform the physical presence of the state's flagship University. In Storrs, search committees were working to replace retirees with new faculty who would be called on to help transform UConn's academic reputation.
The University hit paydirt - in Hartford and in Storrs. UConn 2000 made history, and four assistant professors selected to teach in the School of Engineering are well on their way to doing the same.
Within a year of their arrival at UConn, the four - Fred Ogden, Nitin Padture, Ranga Pitchumani and Lang Tong - won prestigious Young Investigator Program awards, three of them from the Office of Naval Research. Like UConn 2000, this success was unprecedented: only 34 Navy awards are presented annually, and UConn professors landed three of them, while Ogden, an assistant professor of civil and environmental engineering, captured a fourth Young Investigator Program award, this one from the Army Research Office.
The granting agencies, and UConn, chose well. Though Tong has left UConn for Cornell University, Ogden, Padture and Pitchumani have combined to bring more than $2.5 million in grants to Storrs. Between them, they have helped several dozen graduate students advance their careers, as well as a number of undergraduates they have brought to their laboratories. And as they approach the end of their three-year Young Investigator Program funding, they have contributed significantly to their fields of study.
"The solid achievements and promise of these young faculty members bode well for the research success and momentum of the School of Engineering as we strive to build a program of unmatched excellence," says Amir Faghri, dean of the School of Engineering.
While all three professors have been working on projects important to the defense industry, their research has tremendous value to a variety of industries and the environment. Ogden's research also has the potential to save lives.
Ogden's initial research project, building on work he had begun while earning a doctorate at Colorado State University, focused on finding a way to predict rainfall amounts more accurately and to forecast how and where, after a storm, the run-off would collect. U.S. Army officials, who control nearly 50 million acres of land across the country, half of it devoted to around-the-cloc k training exercises, knew they were slowly destroying the land and they turned to Ogden for advice.
Ogden's research, conducted in collaboration with researchers at the University of Iowa, is two-fold, using radar to measure the amount of rainfall likely to occur during any given downpour and the areas potentially affected and, secondly, to study what happens to the water once on land, including runoff and the collection of moisture in the soil. Through Ogden's land-surface modeling, Army engineers will know when they should - or should not - schedule training exercises with heavy equipment, and what areas they must avoid to keep from destroying it.
Ogden also was called in to Fort Collins, Colo., after a rainfall of "Biblical proportions" destroyed portions of the city. Between 6 and 11 p.m. on July 28, 1997, the rainfall measured eight inches, Ogden says. Civil preparedness officials and police scrambled to move residents out of low-lying areas, but they didn't have the proper tools to know what was occurring throughout the city.
During the downpour, a wall of water on the city's eastern side burst over railroad tracks, smashing into a mobile home park. Five people died. National Science Foundation-funded simulations after the flood, using Ogden's hydrologic model, made it clear that his computer simulations would have been of great assistance to emergency managers. In the future, Ogden's research may help prevent loss of life.
Now Ogden is receiving funding through the Army Corps of Engineers, and is helping initiate a project to develop a model that, in five to 10 years, may allow the Army Corps to model runoff in the entire Mississippi Basin. During future floods, the simulations should prove to be a valuable resource in determining when and where to move people in potentially affected areas.
Ogden also has had discussions with Panamanian officials, and may be asked to help them prepare for an onslaught of development proposals for the canal zone, once Panama takes ownership of the tract from the United States later this year.
Ranga Pitchumani, too, is involved in numerous projects, and he also is pleased with his progress as a Navy Young Investigator.
"We've made some significant advances," says Pitchumani, an associate professor of mechanical engineering, who last year added the School of Engineering's Outstanding Junior Faculty award to his honors.
Pitchumani, who came to Storrs from the University of Delaware because UConn offered more opportunities for him to teach, has developed ways to make a variety of composites that are stronger, can be produced with a more consistent quality, and are more cost-effective than their predecessors - a boon for defense and commercial applications alike.
The materials Pitchumani works with, called composites, are not new; they are polymers, such as epoxies and plastics, reinforced with fibers. But what has been used to date, primarily in the defense industry, is not cost-effective, is occasionally of questionable quality, and the manufacturing processes used to develop them are often unreliable - wasting time and money as manufacturers fabricate dozens of products before obtaining one that meets the proper specifications.
Now, as federal spending on the nation's defense ratchets down, polymeric composite materials are increasingly finding use in commercial applications. And in commercial applications, Pitchumani says, cost "is very much a factor."
That means no more room for trial and error when creating products. It means strict quality control. And it means absolute reliability - no weak spots in the material. All of these present a challenge for Pitchumani.
The polymer composites and their manufacturing technologies that Pitchumani has advanced through his research could improve and enable numerous commercial applications. The automotive and aerospace industries are very interested in the progress of work on polymer-based composites. These materials are also being used in the repair and rehabilitation of transportation infrastructures such as roadways and bridges. Reinforced polymeric composites are used in prototype U.S. Army tanks and armored vehicles because they are light-weight and absorb ballistic impacts well. A similar product, based on Kevlar fibers, is used in bulletproof vests. Because polymer composites are light-weight, corrosion-resistant, and strong, they are used in submarine hulls and in other marine applications such as sailboats.
Now Pitchumani has developed a software tool that, using principles of human learning, incorporates knowledge of the physical principals that govern the process, and uses it to monitor and steer the flow of liquid polymers injected into a mold consisting of a stack of paper-thin fiber reinforcement mats. The program controls when the liquid can move rapidly through an area, and when it must slow down, to better fill areas (and thereby eliminate weak spots in the product) where unforeseen roadblocks and unpredictable variabilities in the material impede complete coverage.
But what most pleases Pitchumani is his novel method for heating the matrix - which causes the liquid resins to harden. Turning into the teacher, Pitchumani compares the process to cooking a turkey. Until now, fiber-filled polymers have been hardened from the outside in, a slow, costly process that could take up to six hours per piece, because care must be exercised not to burn he outer shell - the skin on the turkey - while cooking, or hardening, the inside.
Pitchumani's answer is to embed the matrix with small carbon mats, which release heat when an electric current is passed through them. Consequently, by firing electrical impulses through the material, the interior of the composite is heated and hardened, even as conventional methods are used to harden the exterior shell. A bonus is that the carbon mats strengthen the already strong composite.
The researcher is working on filing for a patent on his innovation.
Nitin Padture, an associate professor in the Department of Metallurgy and Materials Engineering, also is working to strengthen materials used in numerous applications - ceramics. And he also is familiar with the patenting process - he has three pending.
In the 1967 coming-of-age movie, The Graduate, Dustin Hoffman, playing Benjamin Braddock, was told by his uncle that the future could be summed up in one word. "Plastics."
Fast forward 31 years. The watchword in 1999 is "ceramics" which, according to the American Ceramic Society, is "the miracle material."
Nitin Padture doesn't disagree. Sitting in his nearly paperless, studiously neat office, Padture ticks off the miraculous properties of ceramics: corrosion resistant, oxidation resistant, a thermal insulator, practically heat resistant, lightweight, stiff.
"Remarkable properties," he says. "Their failure, though, is that they're brittle. It's the Holy Grail of researchers - we can make them tough, but it's extremely expensive because of the composites needed to make them resistant to failure."
Padture, however, thinks he's approaching the grail. And he has three patents pending to prove it. But he's not there yet. Not quite.
Padture says one of the challenges of making ceramics more resilient is that it is so hard and costly to add reinforcements to the material. So Padture is working instead with the atomic structure of the composite, introducing the strengthening fibers and grains of materials as the piece is being shaped.
Padture, who worked at the National Institute of Standards and Technology before coming to UConn, says working with ceramics is very attractive because they have so many applications and, consequently, there are many agencies and industries interested in funding related research. Ceramics, he says, can replace many of the functions now served by metals, and can also coat metals to protect them from high temperatures, in situations such as the Space Shuttle.
Those applications, should Padture's research continue to improve the toughness of ceramics, will only increase - as will the reputation of the Institute of Materials Science and the University as the young investigators move forward in their careers.