WPI Research is the research magazine of Worcester Polytechnic Institute. It contains news and features about graduate research in the arts and sciences, business, and engineering, along with notes about new grants, books, and faculty achievements.
Issue link: http://wpiresearch.epubxp.com/i/90696
RESEARCH NOTEBOOK Groundbreaking Tests Explore Post-earthquake Fires In many large earthquakes, much of the damage to buildings and infrastructure is the result of fires that break out in the aftermath of the seismic event as building systems designed to suppress fires and prevent their spread fail. In the spring of 2012, a team of researchers from WPI's Fire Protection Engineering Department, led by associate professor Brian Meacham, took part in an unprecedented, $5 million study of the effects of earthquakes and post-quake fires on high-value buildings like hospitals and data centers. Supported by a coalition of government agencies and industry partners, the study was cen- tered on a five-story building (at right) constructed atop the nation's largest outdoor shake table, located at the Englekirk Structural Engineering Center at the University of California, San Diego. Among the systems installed in the building were passive fire protection components, including doors, ceiling systems, partition walls, and firestop materials, and active fire suppression systems, including a heat-activated fire door and sprinklers. After each in a series of simulated earthquakes, some registering as high as 7.9 on the Richter scale, Meacham and his team inspected those systems. They also ignited pans of heptane and used temperature and smoke movement sensors to assess how damage from the simulated earthquakes might affect the ability of the active and passive systems to contain fires and prevent the spread of smoke. While most systems performed well for small and moderate earth- quake motions, some experienced failures under larger motions, including the exterior balloon framing system, which separated from interior walls and floor slabs, creating the potential for smoke to spread to floors above. "It will take some time before we assess all the data, but trying to better understand this failure mode and implications for fire spread is important," Meacham says. The test results will likely point to needed "changes to codes, standards, and design guidelines, and to fire safety management plans, evacuation plans, response and recovery plans, and busi- ness continuity plans for hospitals and emergency responders," he says. "By understanding better what could happen, hospitals and emergency responders can be better prepared to address what- ever conditions they face should a post-earthquake fire occur." New Insight into Monarch Butterfly Navigation To successfully navigate 2,500 miles from the northern United States to central Mexico each fall, the monarch butterfly uses a time- compensated sun compass. Critical components of this compass mechanism include light-sensitive circadian clocks located in the insect's antennae, which enable it to maintain a constant flight di- rection despite the changing position of the sun throughout the day. A study published this year in the prestigious journal Nature Com- munications shed new light on how the butterfly's brain uses the information from those clocks and what happens when the clocks malfunction. The study, conducted in the lab of Steven Reppert, [2] MD, professor of neurobiology at the University of Massachusetts Medical School, was co-authored by Robert Gegear, assistant professor of biology and biotechnology at WPI. In a series of experiments, the team learned that timing information from the two antennae is integrated within the butterfly's brain, but that the clocks in each antenna work independently. In fact, only one antenna is needed for successful navigation. However, if both antennae are present, but send conflicting circadian information to the brain, the brain tries to knit the divergent data together and ends up pointing the butterfly in the wrong direction.