MIT News: Civil & Environmental Engineering

October 29, 2018

  • In Amman, Jordan, last week, a class of students — half of them refugees — began a one-year course of study in computer science and entrepreneurship, designed by MIT. The program will earn them a certificate that, along with internships with local companies throughout the program, could help them advance to better-paying positions in the region.

    The new program, launched during a Solve competition at MIT, is called the Refugee Action (ReACT) Certificate Program. Run by Executive Director Robert Fadel, who previously worked for the One Laptop Per Child project (also an MIT spinoff), the program begins with an intensive two-week session of in-person lectures in innovation, design, and entrepreneurship, led by MIT faculty members and students.

    The 18 members of the initial class will then spend the remainder of the program taking a series of online classes through MITx and working about 20 hours per week as interns with companies in the region. The project, Fadel says, will “bring an MIT-caliber education to refugees and other displaced populations, where they live.”

    Fadel points out that according to figures from the UN High Commissioner for Refugees, only about 1 percent of refugees have access to higher education, compared to a global average of 34 percent, meaning that “hundreds of thousands of university-qualified students are unable to realize their potential.” The new program is a step toward expanding that access.

    The initial program was made available to any qualified registered refugees, asylees, or other forcibly displaced people, Fadel says, as well as to qualified citizens of Jordan. The organizers made extra efforts to promote the program to women, and because access to records can be difficult for displaced people, applying to the program does not require transcripts or standardized test scores.

    The program includes five online courses — two in computer science, and one each in data science, innovation, and leadership. The courses will be taught by a combination of MIT faculty and students, both live and on the edX platform.

    The concept was initially created under the leadership of Admir Masic, the Esther and Harold E. Edgerton Career Development Professor in the Department of Civil and Environmental Engineering, who as a child was a refugee from Bosnia and Herzegovina whose family fled to a refugee camp in Croatia. He then lived in Germany and Italy, where he earned his college degrees. “I know firsthand that a good education is the ticket to a better life,” he says.

    This initial program drew about 500 applicants, from 20 nations, including some as far from Jordan as Brazil and Japan. To make up for the lack of formal transcripts, the applicants were given special tests in math and English in order to qualify. They also submitted videos in which they described what they would do with a $100,000 investment if it were offered. The selected students came from four areas: Jordan, Syria, Lebanon, and the Occupied Territories. The initial class is composed of 50 percent women, as the organizers had hoped.

    The inclusion of internships for all the students, Fadel says, “is critical in providing practical training. It means they can demonstrate what they’re learning in their classes in the workplace right away.”

    And that combination, he says, provides “value for the students, but also value for the companies. It’s a way of identifying and refining talent for them.” As for the students, “this will be a real resume booster.”

    After this initial year, Fadel says, the hope is that the program will expand, in both the number of students accepted and the locations where it is offered. Already, he says, “we’ve gotten tremendous support from the MIT community.”

    At the kickoff two-week session in Amman, students are working both individually and in teams, with activities including using a maker lab, working with coding architecture, and participating in design and innovation workshops, soft-skills seminars, and industry panels. They are also familiarizing themselves with the edX platform they will be using, and getting to know the instructors.

    As the year goes on, many of the students will be able to stay in touch and share experiences through local centers where they can work and study together. Others who are not in close proximity will be able to connect through a dedicated Facebook page, Fadel says.

    “What we’re really doing is offering the students an opportunity to sharpen their skills in computer and data science, but also in innovation and how to be entrepreneurial,” Fadel says.

  • The proliferation of smartphones, vehicle-sharing apps, and traffic sensors has amounted to a wealth of data that can be used to provide insight for increasing the efficiency and sustainability of transportation networks.

    Such data is particularly valuable to graduate students like Tianli Zhou, a PhD candidate in the Interdepartmental Program in Transportation in the Department of Civil and Environmental Engineering, who uses the information to design vehicle-sharing services.

    “Car sharing became more popular in the last decade, so a lot of data has accumulated over the years,” Zhou says. “So the main questions are how do you help the practitioners of car-sharing services, and also the city planners, to design a better car-sharing system?"

    With a background in industrial engineering, Zhou didn’t work on transportation systems until he was a junior at Tsinghua University in Beijing. There, Zhou worked closely with Professor Hai Jiang SM ’04, PhD ’06 to create an offline transportation itinerary planning app. Zhou received the Award for Exceptional Performance in Student Research Training Program at Tsinghua University for the app, and the app won second prize in the 2012 AutoNavi China Location Based Service Challenge. Zhou credits this experience with introducing him to the field of transportation.

    “I think transportation is one of the most important topics in future urban contexts,” Zhou says. “Traffic congestion and the resulting air pollution are huge issues in many cities worldwide and I want to do something to mitigate this problem.”

    For his master’s thesis at MIT — completed with Chancellor and Ford Professor of Engineering Cynthia Barnhart and Carolina Osorio, an associate professor of civil and environmental engineering — Zhou studied data from Hubway, the Boston area’s bicycle-sharing system, to see how bike sharing could be used to supplement the public transportation network and attract more individuals to use multiple modes of transportation for their trips or commutes.

    Now, Zhou is working with Osorio and fellow graduate student Evan Fields, a PhD candidate in MIT’s Operations Research Center, to study data from the car-sharing company Zipcar. The project is funded by Ford.

    For the project, Zipcar provided the researchers with “high resolution,” or extremely detailed, reservation data from Boston over a two-year period. Among the data was anonymized information on the location of preferred rental vehicles, reservation times, and the times users picked up and returned the vehicles.

    Using this information, Zhou and Fields infer demand for vehicles and develop algorithms to inform best practices for car-sharing services and to make such services more convenient for users.

    “Some researchers make assumptions about this type of data. We make a lot fewer assumptions and use the high resolution data to inform our work,” Zhou says. “We call this a ‘data-driven method,’ because we can use this data to make direct, evidence-based suggestions.”

    Fields considers this data-driven method a highlight of the research project.

    “This is a really fun project to work on because of the data we have from Zipcar; it’s so rich and complete. We have all of the reservation data from Boston for a two-year period, so we can see everything,” Fields says. “We can ask all types of questions like, ‘Do people like to use Zipcar on the weekends?’ or ‘Do people want long trips?’ We can look in the data and see the answers, and we know the data we get back is the truth. It is so rare to be able to write a query and see what happens for real.”

    By creating and using a smart sampling strategy on the historical car reservation data provided by Zipcar, a simulator proposed by Fields can model the operation of the two-way car-sharing system. Such simulation can effectively replicate the real-life Zipcar fleet utilization rate and is used to infer true demand for the car-sharing service.

    While most simulation methods proposed by previous studies do not scale-up to address car-sharing network design problems for large cities, Zhou proposed a new algorithm, with Fields’ high resolution data-driven simulator embedded, that allows the team to look at the greater Boston area. This algorithm produces suggestions based on the inferred demand, such as where Zipcar should locate its cars for the upcoming month.

    “A large-scale analysis allows us to identify synergies with other mobility services provided throughout the city,” Osorio says. “In particular, we are currently investigating how car-sharing services can complement public transportation services to improve transportation accessibility across the city.”

    The suggestions from the algorithm also have potential to both increase revenue for vehicle-sharing services and to make them more conveniently located for individual use. For example, by placing a certain number of cars in a specific area, with the preferred vehicles, and thus meeting user demand, individuals may be more likely to utilize these services, Zhou says.

    “Helping Zipcar achieve their goals is helpful for everybody, particularly if Zipcar can help fill in gaps in the accessibility of a city, such as places where the T [subway system] doesn’t go,” Fields says. “If we can suggest where to locate the vehicles and simultaneously increase profit, that’s good for Zipcar. It keeps them around and incentivizes operations in Boston, but also provides transportation to the city.”

    Zhou and Fields have submitted their Boston findings and algorithms to an academic journal, and have recently begun to apply the algorithm to similar Zipcar data from Manhattan.

    Both researchers are advised by Osorio, whose research group's projects include traffic optimization, autonomous mobility, and vehicle sharing. Previous work in Osorio’s lab has focused on the sustainability benefits of optimizing traffic light monitoring; a 2015 study found that changing the timing of stoplights in urban areas could reduce greenhouse gas emissions.

    In recent years, the group has developed models and algorithms to enable high-resolution mobility data, such as that of the car sharing project, to be used to optimize the design and the operations of mobility systems at the scale of full cities and metropolitan regions.

    “Vehicle sharing is a way to enhance the sustainability of our transportation system. People don’t have to have their own vehicles, including both bikes and cars. Also, in the current car-sharing industry, there tend to be more compact cars, so it’s better for the environment,” Zhou says. “These aspects of my project makes me feel that I can have an impact on society, and that’s what interested me in this kind of research.”

  • When Mark Twain famously said “If you don’t like the weather in New England, just wait a few minutes,” he probably didn’t anticipate MIT researchers would apply his remark to their microbial research. But a new study does just that.

    A team from MIT, using water samples from the New England coast, found that microbial communities are able to form despite rapidly varying conditions in the coastal environment. Biological communities are typically defined as the set of organisms living and interacting in a certain area, carrying out important ecological functions, such as all the organisms in a forest. In the ocean, however, water is constantly moving, making it more difficult to answer the question of what constitutes a community.

    Using novel analytical techniques, the MIT researchers show that communities of interacting microbes form but are short-lived. They reach their peak abundance after only a few days and are subsequently replaced by another community. Following the forest analogy, imagine returning after a week and finding entirely different species of plants and animals populating the same area.

    This rapid turnover struck the researchers as similar to Twain’s quote: “The good news may be that if you don’t like the microbial community, just wait for a few days,” they quip at the conclusion of their paper, published in Nature Communications

    “We know relatively little about how microbial communities — the assemblage of microbes in the ocean — change over time and space,” says Martin Polz, professor of civil and environmental engineering (CEE) at MIT and corresponding author on the paper. “People have gone out and taken samples in distinct locations, so we are getting to know more about the global diversity, but when you go to a particular location and ask, ‘How is it changing over time?’ we actually know relatively little.” 

    To fill this void, Polz and the research team collected daily ocean water samples from Canoe Cove in Nahant, Massachusetts, over a three-month period.

    Together, the researchers, including graduate student Brian Cleary of the Broad Institute and MIT's computational and systems biology program; former CEE postdoc Antonio Martin-Platero; CEE postdoc Kathryn Kauffman; former CEE postdoc Sarah Preheim; Eric Alm, professor of civil and environmental engineering and biological engineering; Polz; and Dennis McGillicuddy of the Woods Hole Oceanographic Institution analyzed the samples.

    In their analysis the researchers took into account temporal and spatial aspects of water movement, such as from ocean currents. The research was conducted between the summer and fall seasons, and, contrary to what may be expected, the team found that the community formation doesn’t necessarily change as a result of seasonal transitions, but rather follows the every-few-days routine. This is not to say that seasonal changes don’t influence the formation of communities, though.

    “Temperature alone is a huge factor in structuring communities, but it’s not enough to go and sample once per season to have an idea of what’s going on in the season,” says Polz. “The community turnover is much faster than that, and this indicates that the ecological conditions are shifting on equally fast time scales since the organisms respond to physical and chemical changes.”

    That the abundance of specific microbes in the community drops sharply after only a few days signals that they may be competing with other microbes for resources to survive. This suggests that while chemistry and physics govern overall community turnover, within communities biological interactions cause even more rapid fluctuations in species abundances.

    “We think the [rapid community changes] are basically set by the ocean physics. We analyzed chemical and physical data and for some of these events we could identify a characteristic period of upwelling, when nutrient rich deep water is transported to the surface and stimulate a certain set of microbes,” says Polz. “We also looked at satellite data, which measures temperature and chlorophyll, and we saw that features developing in the ocean are corresponding with these communities. The physics really sets the chemical and temperature regimes that trigger the blooms of these communities but physical changes probably also terminate them. Because the water is constantly moving, different water bodies mix, and other local features form.”

    In collaboration with Alm and his lab, the researchers also created a new algorithm to analyze the samples and sequence the genes to get a more complete understanding of the patterns and behavior of the microbial communities. Using the algorithm, Cleary explains, the researchers looked for relationships between microbes based on how they are fluctuating throughout the time series.

    “There are microbes fluctuating around in an environment, but we obviously are not directly observing either the cooperative or competitive interactions between pairs [of microbes], and we aren’t directly observing the low-frequency changes that might correspond to a nutrient regime,” says Cleary. “With our algorithm, we can infer the entire community structure from these fluctuations at different frequency levels.”

    The researchers’ findings also provide insight into the conditions that more permanent organisms in the region face as the microbial plankton turnover. A comprehensive understanding of microbial behavior in the ocean can inform human health, fisheries, and aquaculture, specifically through monitoring water quality. 

    “This paper represents a significant advance in our knowledge of the forces that mediate community assembly in fluid environments, and provides a wealth of new information to support new hypothesis-driven research into the specific mechanisms that underpin this complex association,” says Jack Gilbert, faculty director of the Microbiome Center at the University of Chicago, who was not involved in this work. 

    The research was funded in part by the National Science Foundation and the United States Department of Energy.

  • Members of the MIT engineering faculty receive many awards in recognition of their scholarship, service, and overall excellence. Every quarter, the School of Engineering publicly recognizes their achievements by highlighting the honors, prizes, and medals won by faculty working in our academic departments, labs, and centers.

    The following awards were given from October through December, 2017. Submissions for future listings are welcome at any time.

    Mohammad Alizadeh, Department of Electrical Engineering and Computer Science and the Computer Science and Artificial Intelligence Laboratory, won the SIGCOMM Rising Star Award.

    Lallit Anand, Department of Mechanical Engineering, won the William Prager Medal.

    Regina Barzilay, Department of Electrical Engineering and Computer Science and the Computer Science and Artificial Intelligence Laboratory, was awarded a MacArthur Fellowship.

    Martin Z. Bazant, Department of Chemical Engineering, was named a fellow of the Royal Society of Chemistry.

    Moshe Ben-Akiva, Department of Civil and Environmental Engineering, won the 2017 Robert Herman Lifetime Achievement Award in Transportation Science.

    Sangeeta Bhatia of the Institute for Medical Engineering and Science and the Koch Institute for Integrative Cancer Research, won the Science Club for Girls 2017 Catalyst Award.

    Michael Birnbaum, Department of Biological Engineering and the Koch Institute for Integrative Cancer Research, was awarded the 2017 Packard Fellowship for Science and Engineering.

    Paul C. Blainey, Department of Biological Engineering, won the NIH Director's New Innovator Award.

    Fikile Brushett and Heather Kulik, Department of Chemical Engineering, were featured in Industrial & Engineering Chemistry Research’s 2017 Class of Influential Researchers.

    Cullen Buie, Department of Mechanical Engineering, won the NIH Director's Transformative Research Award.

    Arup K. Chakraborty, Institute for Medical Engineering and Science and Chemical Engineering, was elected to the National Academy of Medicine.

    Edward Crawley, Department of Aeronautics and Astronautics, won The People's Republic of China Friendship Award.

    Elazer Edelman, Institute for Medical Engineering and Science, won the Transcatheter Cardiovascular Therapeutics Career Achievement Award.

    Warren Hoburg, Department of Aeronautics and Astronautics, won R&D Magazine Innovator of the Year.

    Dorothy Hosler, Department of Materials Science and Engineering, was elected a fellow to the American Association for the Advancement of Science.

    Jonathan P. How, Department of Aeronautics and Astronautics, became an IEEE Fellow.

    Ian Hunter, Department of Mechanical Engineering, was elected a National Academy of Inventors Fellow.

    Shafi Goldwasser, Department of Electrical Engineering and Computer Science and the Computer Science and Artificial Intelligence Laboratory, was named the Association of Computing Machinery (ACM) Fellow.

    Roger D. Kamm, Department of Mechanical Engineering and Biological Engineering, won The Robert M. Nerem Education and Mentorship Medal.

    R. Scott Kemp, Department of Nuclear Science and Engineering, was named American Physical Society, 2017 Fellow.

    Heather Kulik, Department of Chemical Engineering, won the  American Chemical Society OpenEye Outstanding Junior Faculty Award.

    Harvey Lodish, Department of Biological Engineering, won the American Society for Cell Biology 2017 Women in Cell Biology Sandra K. Masur Senior Leadership Award.

    Tomás Lozano-Pérez, Department of Electrical Engineering and Computer Science and Computer Science and Artificial Intelligence Laboratory, was named an Association for Computing Machinery (ACM) Fellow.

    Karthish Manthiram, Department of Chemical Engineering, was named one of Forbes 30 Under 30 for Science.

    Muriel Médard, Department of Electrical Engineering and Computer Science and Research Laboratory of Electronics, won the IEEE Communications Society Edwin Howard Armstrong Achievement Award.

    Silvio Micali, Department of Electrical Engineering and Computer Science and Computer Science and Artificial Intelligence Laboratory, became an Association for Computing Machinery (ACM) Fellow.

    Stefanie Mueller, Department of Electrical Engineering and Computer Science, received the 2016 Dissertation Prize at the INFORMATIK 2017 conference in Germany.

    Dava Newman, Department of Aeronautics and Astronautics, won the Women In Aerospace Leadership Award.

    Dava Newman, Department of Aeronautics and Astronautics, won the College of Engineering Honor Award, University of Notre Dame.

    Brad Olsen, Department of Chemical Engineering, will receive the American Physical Society’s 2018 Dillon Medal.

    Max Opgenoord, Mark Drela, Karen Willcox, Department of Aeronautics and Astronautics, won Best Paper at the AIAA Theoretical Fluid Mechanics Conference.

    Pedro M. Reis, Department of Civil and Environmental Engineering and Mechanical Engineering, became an APS Fellow.

    Yuriy Román, Department of Chemical Engineering, will receive the 2018 Robert Augustine Award from the Organic Reaction Catalysis Society.

    Julie Shah, Youssef Marzouk, QiQi Wang, Kerri Cahoy, Department of Aeronautics and Astronautics, were named AIAA Associate Fellows.

    Vivienne Sze, Department of Electrical Engineering and Computer Science and Research Laboratory of Electronics, won an Engineering Emmy Award.

    John Tsitsiklis, Department of Electrical Engineering and Computer Science and the Institute for Data, Systems, and Society, won the Saul Gass Expository Writing Award.

    Evelyn Wang, Department of Mechanical Engineering, won the Foreign Policy's Global Thinkers 2017 Award.

    Evelyn Wang, Department of Mechanical Engineering, was awarded a Professor Amar G. Bose Research Grant.

    Nickolai Zeldovich, Department of Electrical Engineering and Computer Science and the Computer Science and Artificial Intelligence Laboratory, won the 2017 ACM SIGOPS Mark Weiser Award.

  • The air we breathe contains particulate matter from a range of natural and human-related sources. Particulate matter is responsible for thousands of premature deaths in the United States each year, but legislation from the U.S. Environmental Protection Agency (EPA) is credited with significantly decreasing this number, as well as the amount of particulate matter in the atmosphere. However, the EPA may not be getting the full credit they deserve: New research from MIT’s Department of Civil and Environmental Engineering (CEE) proposes that the EPA’s legislation may have saved even more lives than initially reported.

    “In the United States, the number of premature deaths associated with exposure to outdoor particulate matter exceeds the number of car accident fatalities every year. This highlights the vital role that the EPA plays in reducing the exposure of people living in the United States to harmful pollutants,” says Colette Heald, associate professor in CEE and the Department of Earth, Atmospheric and Planetary Sciences.

    The EPA’s 1970 Clean Air Act and amendments in 1990 address the health effects of particulate matter, specifically by regulating emissions of air pollutants and promoting research into cleaner alternatives. In 2011 the EPA announced that the legislation was responsible for a considerable decrease in particulate matter in the atmosphere, estimating that over 100,000 lives were saved every year from 2000 to 2010. However, the report did not consider organic aerosol, a major component of atmospheric particulate matter, to be a large contributor to the decline in particulate matter during this period. Organic aerosol is emitted directly from fossil fuel combustion (e.g. vehicles), residential burning, and wildfires but is also chemically produced in the atmosphere from the oxidation of both natural and anthropogenically emitted hydrocarbons.

    The CEE research team, including Heald; Jesse Kroll, an associate professor of CEE and of chemical engineering; David Ridley, a research scientist in CEE; and Kelsey Ridley SM ’15, looked at surface measurements of organic aerosol from across the United States from 1990 to 2012, creating a comprehensive picture of organic aerosol in the United States.

    “Widespread monitoring of air pollutant concentrations across the United States enables us to verify changes in air quality over time in response to regulations. Previous work has focused on the decline in particulate matter associated with efforts to reduce acid rain in the United States. But to date, no one had really explored the long-term trend in organic aerosol,” Heald says. 

    The MIT researchers found a more dramatic decline in organic aerosol across the U.S. than previously reported, which may account for more lives saved than the EPA anticipated. Their work showed that these changes are likely due to anthropogenic, or human, behaviors. The paper is published this week in Proceedings of the National Academy of Sciences.

    “The EPA report showed a very large impact from the decline in particulate matter, but we were surprised to see a very little change in the organic aerosol concentration in their estimates,” explains Ridley. “The observations suggest that the decrease in organic aerosol had been six times larger than estimated between 2000 and 2010 in the EPA report.”

    Using data from the Interagency Monitoring of Protected Visual Environments (IMPROVE) network the researchers found that organic aerosol decreased across the entire country in the winter and summer seasons. This decline in organic aerosol is surprising, especially when considering the increase in wildfires. But the researchers found that despite the wildfires, organic aerosols continue to decline. 

    The researchers also used information from the NASA Modern-Era Retrospective analysis for Research and Applications to analyze the impact of other natural influences on organic aerosol, such as precipitation and temperature, finding that the decline would be occurring despite cloud cover, rain, and temperature changes. 

    The absence of a clear natural cause for the decline in organic aerosol suggests the decline was the result of anthropogenic causes. Further, the decline in organic aerosol was similar to the decrease in other measured atmospheric pollutants, such as nitrogen dioxide and carbon monoxide, which are likewise thought to be due to EPA regulations. Also, similarities in trends across both urban and rural areas suggest that the declines may also be the result of behavioral changes stemming from EPA regulations.

    By leveraging the emissions data of organic aerosol and its precursors, from both natural and anthropogenic sources, the researchers simulated organic aerosol concentrations from 1990 to 2012 in a model. They found that more than half of the decline in organic aerosol is accounted for by changes in human emissions behaviors, including vehicle emissions and residential and commercial fuel burning. 

    “We see that the model captures much of the observed trend of organic aerosol across the U.S., and we can explain a lot of that purely through changes in anthropogenic emissions. The changes in organic aerosol emissions are likely to be indirectly driven by controls by the EPA on different species, like black carbon from fuel burning and nitrogen dioxide from vehicles,” says Ridley. ”This wasn’t really something that the EPA was anticipating, so it’s an added benefit of the Clean Air Act.”

    In considering mortality rates and the impact of organic aerosol over time, the researchers used a previously established method that relates exposure to particulate matter to increased risk of mortality through different diseases such as cardiovascular disease or respiratory disease. The researchers could thus figure out the change in mortality rate based on the change in particulate matter. Since the researchers knew how much organic aerosol is in the particulate matter samples, they were able to determine how much changes in organic aerosol levels decreased mortality.

    “There are costs and benefits to implementing regulations such as those in the Clean Air Act, but it seems that we are reaping even greater benefits from the reduced mortality associated with particulate matter because of the change in organic aerosol,” Ridley says. “There are health benefits to reducing organic aerosol further, especially in urban locations. As we do, natural sources will contribute a larger fraction, so we need to understand how they will vary into the future too.”

    This research was funded, in part, by the National Science Foundation, the National Aeronautics and Space Administration, and the National Oceanic and Atmospheric Administration.