Natural gas is used both as a general energy source and as a fuel in many industrial processes. Its role, though, has been hampered by the fact that users must boost temperatures to high levels — 1,400 degrees C. and up — to get a stable flame. Selected chemical catalysts could potentially permit the fuel to burn well at lower temperature levels. In a kind of Catch-22, though, most such catalysts start to lose their effectiveness when temperatures rise. And, the natural gas itself tends to produce high pollution. Jackie Ying, associate professor of chemical engineering, is on track to the solution of this problem. She’s created a variant of standard catalysts that lets users ignite methane — natural gas’s main ingredient — at temperatures as low as 400 degrees C. yet still is relatively stable at 1,100 degrees. The key is an approach her group developed that lets them form catalysts whose “building blocks” are measured in billionths of a meter. Among other things, this structure gives such chemicals much more active surface area than conventional catalysts, thus making them function at lower temperatures. The catalysts’ unique qualities, says Ying — who was named one of the Technology Review’s “top 100 innovators” last fall — mean they have “potential practical applications in the ultralean catalytic combustion of methane.” They may also be valuable in a range of other processes that call for catalysts.
Spotting Cancer’s Signs
Subtle changes in someone’s tissues can often foreshadow the emergence of cancer. Unfortunately, such changes are tough to observe for most tumor types. An MIT group, though, has now expanded the list of cancers for which early warning signs may be obtainable. The group’s system, developed in MIT’s Spectroscopy Laboratory, relies on shining ordinary white light on tissue, then doing sophisticated computer tests of the rays reflected to look for precancerous changes. The system’s probe is a special endoscope that can be worked into confined passageways in the body. In patient trials, doctors at Brigham and Women’s Hospital in Boston successfully used it to pinpoint worrisome changes in the colon and esophagus. Rajan Gurjar, a postdoctoral fellow working with MIT physicist Michael Feld, reported on the system at a scientific meeting earlier this spring.
An MIT grad student has designed a rocket engine that’s about the size of a quarter and made out of the same material as electronic micro-chips. The silicon devices have been test-fired using oxygen and methane, and “the results were very promising,” says developer Adam London. Far more efficient than their large-engine counterparts, the devices could be used in bunches for the launching of, say, very small satellites. One hundred such rockets would generate 200 to 300 pounds of thrust, or potentially enough to launch a soda can-sized payload into orbit. London’s project is part of a major MIT-based effort to develop micro-propulsion systems. Alan Epstein, professor of aeronautics and astronautics, heads the effort.
Brucellosis is a bacterial infection that’s rarely fatal but can last for months. The disease, whose human form is marked by fever and severe weakness and pain, is epidemic in some developing countries. Now, though, there may be hope for preventing it. The possibility, surprisingly, emerged from MIT-based studies of plant infections. Biologist Graham Walker’s group discovered that a gene dubbed bacA is critical to the success of a plant bacterium that infects alfalfa, in so doing providing the plant with needed nutrients. His associate, Kristin LeVier, used the finding to launch a hunt for a similar gene in bacteria that infect humans and animals. She found one in the class of microbes called brucellae, which cause brucellosis. Walker, who has worked with a Louisiana State group on the research, says further plant research could shed light on the “poorly understood mechanisms that enable brucellae to establish infections” in both humans and cows. Meanwhile, lab studies suggest that blocking the gene’s activities can slow or even halt the disease process —- a discovery that may ultimately yield a vaccine for the human form of the disease.