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    Cave deposits show surprising shift in permafrost over the last 400,000 years

    Nearly one quarter of the land in the Northern Hemisphere, amounting to some 9 million square miles, is layered with permafrost — soil, sediment, and rocks that are frozen solid for years at a time. Vast stretches of permafrost can be found in Alaska, Siberia, and the Canadian Arctic, where persistently freezing temperatures have kept carbon, in the form of decayed bits of plants and animals, locked in the ground.

    Scientists estimate that more than 1,400 gigatons of carbon is trapped in the Earth’s permafrost. As global temperatures climb, and permafrost thaws, this frozen reservoir could potentially escape into the atmosphere as carbon dioxide and methane, significantly amplifying climate change. However, little is known about permafrost’s stability, today or in the past.

    Now geologists at MIT, Boston College, and elsewhere have reconstructed permafrost’s history over the last 1.5 million years. The researchers analyzed cave deposits in locations across western Canada and found evidence that, between 1.5 million and 400,000 years ago, permafrost was prone to thawing, even in high Arctic latitudes. Since then, however, permafrost thaw has been limited to sub-Arctic regions.

    The results, published today in Science Advances, suggest that the planet’s permafrost shifted to a more stable state in the last 400,000 years, and has been less susceptible to thawing since then. In this more stable state, permafrost likely has retained much of the carbon that it has built up during this time, having little opportunity to gradually release it.

    “The stability of the last 400,000 years may actually work against us, in that it has allowed carbon to steadily accumulate in permafrost over this time. Melting now might lead to substantially greater releases of carbon to the atmosphere than in the past,” says study co-author David McGee, associate professor in MIT’s Department of Earth, Atmospheric, and Planetary Sciences.

    McGee’s co-authors are Ben Hardt and Irit Tal at MIT; Nicole Biller-Celander, Jeremy Shakun, and Corinne Wong at Boston College; Alberto Reyes at the University of Alberta; Bernard Lauriol at the University of Ottawa; and Derek Ford at McMaster University.

    Stacked warming

    Periods of past warming are considered interglacial periods, or times between global ice ages. These geologically brief windows can warm permafrost enough to thaw. Signs of ancient permafrost thaw can be seen in stalagmites and other mineral deposits left behind as water moves through the ground and into caves. These caves, particularly at high Arctic latitudes, are often remote and difficult to access, and as a result, there has been little known about the history of permafrost, and its past stability in warming climates.

    However, in 2013, researchers at Oxford University were able to sample cave deposits from a few locations across Siberia; their analysis suggested that permafrost thaw was widespread throughout Siberia prior to 400,000 years ago. Since then, the results showed a much-reduced range of permafrost thaw.

    Shakun and Biller-Celander wondered whether the trend toward a more stable permafrost was a global one, and looked to carry out similar studies in Canada to reconstruct the permafrost history there. They linked up with pioneering cave scientists Lauriol and Ford, who provided samples of cave deposits that they collected over the years from three distinct permafrost regions: the southern Canadian Rockies, Nahanni National Park in the Northwest Territories, and the northern Yukon.

    In total, the team obtained 74 samples of speleothems, or sections of stalagmites, stalactites, and flowstones, from at least five caves in each region, representing various cave depths, geometries, and glacial histories. Each sampled cave was located on exposed slopes that were likely the first parts of the permafrost landscape to thaw with warming.

    The samples were flown to MIT, where McGee and his lab used precise geochronology techniques to determine the ages of each sample’s layers, each layer reflecting a period of permafrost thaw.

    “Each speleothem was deposited over time like stacked traffic cones,” says McGee. “We started with the outermost, youngest layers to date the most recent time that the permafrost thawed.”

    Arctic shift

    McGee and his colleagues used techniques of uranium/thorium geochronology to date the layers of each speleothem. The dating technique relies on the natural decay process of uranium to its daughter isotope, thorium 230, and the fact that uranium is soluble in water, whereas thorium is not.

    “In the rocks above the cave, as waters percolate through, they accumulate uranium and leave thorium behind,” McGee explains. “Once that water gets to the stalagmite surface and precipitates at time zero, you have uranium, and no thorium. Then gradually, uranium decays and produces thorium.”

    The team drilled out small amounts from each sample and dissolved them through various chemical steps to isolate uranium and thorium. Then they ran the two elements through a mass spectrometer to measure their amounts, the ratio of which they used to calculate a given layer’s age.

    From their analysis, the researchers observed that samples collected from the Yukon and the farthest northern sites bore samples no younger than 400,000 years old, suggesting permafrost thaw has not occurred in those sites since then.

    “There may have been some shallow thaw, but in terms of the entire rock above the cave being thawed, that hasn’t occurred for the last 400,000 years, and was much more common prior to that,” McGee says.

    The results suggest that the Earth’s permafrost was much less stable prior to 400,000 years ago and was more prone to thawing, even during interglacial periods when levels of temperature and atmospheric carbon dioxide were on par with modern levels, as other work has shown.

    “To see this evidence of a much less stable Arctic prior to 400,000 years ago, suggests even under similar conditions, the Arctic can be a very different place,” McGee says. “It raises questions for me about what caused the Arctic to shift into this more stable condition, and what can cause it to shift out of it.”

    This research was supported, in part, by the National Science Foundation, the National Sciences and Engineering Research Council of Canada, and the Polar Continental Shelf Program. More

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    Top collegiate inventors awarded 2021 Lemelson-MIT Student Prize

    Following a year that demonstrated the importance and practical applications of scientific advancement and invention, the Lemelson-MIT Program announced seven winners of its annual 2021 Lemelson-MIT Student Prize on April 26, World Intellectual Property Day. The program awarded a total of $90,000 to four graduate students and three undergraduate teams from across the country. The majority of winners have filed for patents, while others have been awarded full or provisional patents. Their inventions range from an innovative approach to plastic pollution in Uganda to self-driving wheelchair technology.

    “We are thrilled with and inspired by the quality of inventions this year,” says Michael J. Cima, faculty director of the Lemelson-MIT Program and associate dean of innovation at the MIT School of Engineering. “This group of students has performed tremendous work amidst difficult circumstances, often working remotely, knowing their research is too important to slow down. Science and technology have been at the forefront of conversation over the past year, and this diverse group of students is well-positioned to lead us toward great advances for years to come,” Cima says.

    Supported by The Lemelson Foundation and administered by the School of Engineering, the Lemelson-MIT Student Prize recognizes and provides catalyst funding to young inventors who have dedicated themselves to providing scalable solutions to real-world problems around the globe. This year’s winners have invented solutions that address pregnancy-related complications, market losses in the agricultural industry, obstacles impeding smooth patient recoveries, and other pressing problems in society. Recipients were selected from a diverse and highly competitive pool of hundreds of applicants from colleges and universities across the United States. 

    “Congratulations to this year’s winners for their remarkable achievements and dedication to solving some of the biggest challenges facing society today,” says Carol Dahl, executive director of the Lemelson Foundation. “It’s particularly exciting to see this year’s cohort of graduate winners is all women, given the fact that a large gender disparity exists in patenting. More inventors are needed from communities historically underrepresented in invention, including women, if we are going to effectively solve the challenges of today and tomorrow.”

    2021 Lemelson-MIT Student Prize winners were selected based on the overall inventiveness of their work, the invention’s potential for scalable commercialization or adoption, and youth mentorship experience. They are:

    The “Cure it!” Lemelson-MIT Student Prize: Rewarding technology-based inventions that involve health care.

    •    Nicole Black of Harvard University, $15,000 Graduate Winner The eardrum often becomes damaged through traumatic head injuries, blast injuries, chronic ear infections, and other incidents, affecting millions of people worldwide every year. Current eardrum graft materials are tissues taken from other parts of the body. These current grafts intend to repair damage, yet do not integrate well with the eardrum and surrounding tissue, resulting in poor healing and hearing outcomes that often require further surgery. Using novel biodegradable materials and 3D printing techniques, Black invented a tunable, biomimetic eardrum graft called PhonoGraft. Because PhonoGraft is able to retain the circular and radial structure of the eardrum, its sound-induced motion is similar to that of original eardrum tissue. Additionally, PhonoGraft acts as a kind of scaffolding that bridges the hole and becomes part of the native tissue, allowing the eardrum to essentially heal itself and restore hearing more effectively.

    •    Mira Moufarrej of Stanford University, $15,000 Graduate WinnerPregnancy-related complications like preeclampsia and preterm delivery pose significant risks to both fetal and maternal health and are often difficult to detect in time for effective medical intervention. Moufarrej developed three novel liquid biopsy tests that monitor prenatal health and identify high-risk pregnancies by more accurately predicting due date, risk of preeclampsia, and likelihood of preterm delivery, making assessments possible well in advance of the mother becoming symptomatic. Following preclinical validation, these affordable, simple, and reliable maternal blood tests may change the standard of care for preeclampsia and preterm delivery — risks that no other test can currently predict early enough to allow for meaningful clinical intervention.

    •    Innerva: Bruce Enzmann, Michael Lan, and Anson Zhou of Johns Hopkins University, $10,000 Undergraduate Team WinnerTargeted muscle reinnervation (TMR), a procedure to connect severed nerves to smaller motor nerves, is an increasingly popular method for treating peripheral nerve injuries, as it partially guides nerve regeneration and makes it possible for amputees to more effectively operate prosthetic devices. About 30 percent of TMR patients, however, experience pain due to nerve tumors, or neuromas, that result from the inherent differences in size between the newly connected nerves. Innerva’s invention is a nerve conduit that creates an interface between the different sized nerves connected during TMR, modulating nerve regeneration and preventing the formation of neuromas.

    The “Eat it!” Lemelson-MIT Student Prize: Rewarding technology-based inventions that involve food/water and agriculture.

    •    Hilary Johnson of MIT, $15,000 Graduate WinnerCentrifugal pumps are integral drivers in many fluid systems, such as clean water distribution, wastewater treatment, crop irrigation, oil and gas production, and pumped hydro energy storage. Requiring significant energy to operate, collectively these pumps consume 6 percent of annual U.S. electricity. Hilary’s invention is a variable volute pump, a new category of centrifugal pumps that mechanically adapts the hydraulic chamber to adjust to fluctuating system demand. Variable volute pumps show the potential to significantly improve efficiency and operating range across applications by adjusting the spiral fluid passages to match the flow rate.

    •    Grain Weevil: Benjamin Johnson and Zane Zents of the University of Nebraska at Omaha, $10,000 Undergraduate Team WinnerLarge grain bins are used to store surplus grain supplies and allow farmers to hold their yield for higher prices. Managing grain condition and extraction require farmers to physically enter the grain bin, which is difficult and dangerous, often trapping and even killing farmers. A lack of proper management and extraction systems cause a 30 percent loss in cereal grain value worldwide. The Grain Weevil is a grain extraction and bin management robot that scurries across the top of the grain within a bin, smoothing out clumps so that the grain can be properly aerated and easily extracted from the bin. This device helps farmers safely and efficiently manage the extraction of grain from the bin, as well as maintain grain quality while in storage.

    The “Move it!” Lemelson-MIT Student Prize: Rewarding technology-based inventions that involve transportation and mobility.

    •    Adventus Robotics: Maya Burhanpurkar and Seung Hwan An of Harvard University, $10,000 Undergraduate Team WinnerPower wheelchairs present formidable barriers to mobility for users unable to operate a joystick, and manual wheelchairs operated by porters within hospitals can increase the potential for disease transmission between patients and staff. To solve these issues, the Adventus team developed a hardware and software kit that can be retrofitted to power wheelchairs already on the market to convert them into Level 5 (fully autonomous) self-driving wheelchairs. Adventus’ system transcends existing assistive technologies by using artificial intelligence and fail-safe sensors for edge detection and collision prevention. In light of Covid-19, the team’s technology has the potential to be used in a variety of other applications like autonomous floor cleaning and disinfecting.

    The “Use it!” Lemelson-MIT Student Prize: Rewarding technology-based inventions that involve consumer devices and products.

    •    Paige Balcom of the University of California at Berkeley, $15,000 Graduate WinnerTakataka Plastics is a technology and systems-level solution for plastic waste in Uganda that locally recycles plastic waste and creates jobs for vulnerable youth. Paige developed small-scale, locally built, low-cost machines to transform plastic waste into saleable products such as wall tiles for buildings, personal protective equipment, and consumer goods. This technology is especially innovative for PET waste because PET plastic (water and soda bottles) currently cannot be recycled anywhere in Uganda, and exporting the waste is difficult and inaccessible to most local recyclers.

    Collegiate inventors interested in applying for the 2022 Lemelson-MIT Student Prize can find more information via the Lemelson-MIT Program. The 2022 Student Prize application will open in late spring 2021. More

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    To advance climate action, MIT seeks partnerships beyond industry

    MIT is uniquely positioned to lead the way on the technological advances and policy options needed to address climate change. At the second MIT Climate Engagement Forum of the semester, students, faculty, alumni, and staff described the many ways they are engaging an array of organizations to bring real solutions to the climate crisis. Several participants in the discussion offered suggestions from their own personal and professional experiences on how the Institute can make tackling the climate crisis part of its core mission. “The problems are too big and too interconnected for any institution, even this one, to solve alone,” said Maria Zuber, MIT’s vice president for research, in opening remarks.

    As MIT prepares to release its second Plan for Action on Climate Change this spring, the Office of the Vice President for Research is taking stock of the Institute’s climate progress to date. The forum, hosted by the Environmental Solutions Initiative (ESI), brought together a diverse group: seniors Kiara Wahnshafft and Megan Guenther, graduate students Pervez Agwan and Caroline White-Nockleby, alumni Lucy Milde and Gail Greenwald, MIT Corporation member Diana Chapman-Walsh, Senior Associate Dean Kate Trimble, and faculty members Megan Black, Desiree Plata, Timothy Gutowski, and John E. Fernandez.

    Supporting students to ensure an “all of MIT” approach

    MIT is known for providing students with hands-on training through experiential learning opportunities and internships. Industry leaders are increasingly recognizing the value of having technically skilled employees who can also navigate the messiness of real-world problem-solving, said John Fernández, director of ESI.

    “There are a growing number of companies who see that one of the obstacles to a sustainable future for them is they don’t have the workforce to get there,” Fernández said. “I think this is an extraordinary opportunity for us.”

    Similarly, Kate Trimble, director of the Office of Experiential Learning, told forum attendees that sustainability should be the “crown jewel” of an MIT education. “I imagine a world where sustainability really permeates everything that we do, and sustainability is something that students have to go out of their way to avoid, as opposed to specially seeking it out,” Trimble said. To do that, MIT needs to provide more opportunities for students to develop “change-making skills,” she said, and reflect on what they’re learning out in the field during internships.

    Timothy Gutowski, an MIT professor of engineering, described the hands-on class he co-teaches called “Solving for carbon neutrality at MIT.” Diving deep into MIT’s own emissions has given him a new perspective on the obstacles to carbon neutrality, both on campus and in the wider world. “Quite frankly, they often turn out to be people — human behavior, how we get along, how we cooperate, how we solve problems.”

    Pervez Agwan, an MBA candidate and president of the MIT Energy Club, said that he has found a community of like-minded students working on energy problems. But the Institute should do a better job of instilling in all students that MIT stands for sustainability and climate action. “It’s not because they don’t have an interest,” he said. “They just don’t know what’s happening, and it’s not part of our culture.”

    Engaging outside of MIT

    One of the pillars of MIT’s 2015 Plan for Action on Climate Change is to better educate government and industry leaders on climate change. Senior Kiara Wahnschafft remarked that she worked on Massachusetts’ recent climate bill as part of an internship she did with the Environmental Solution Initiative’s Rapid Response Group. The Institute should scale up those partnerships so that policymakers know to turn to MIT for scientifically-sound climate research. “In my ideal world, MIT is the climate policymaking hub,” she said.

    A key component of that will be continually evaluating what successful engagement with partners looks like, said Gail Greenwald ‘75, a board member of Launchpad Venture Group. Similar to how MIT tracks its emissions reductions project, the Institute needs to ensure its partnerships advance decarbonization off-campus. “We don’t have time to rest on our laurels or to be participating in greenwashing,” she said.

    At the same time, meeting attendees stressed that MIT should not shy away from working with companies that have less-than-sterling reputations on climate change. “It doesn’t have to be an ‘all or nothing’ approach,” said Wahnschafft. “We can have a great relationship with a company and do research or some other kind of partnership, and still say we disagree with their current tax bill in Washington.”

    Lucy Milde ’20 called on MIT to weave ethical considerations into its work around climate mitigation and adaptation. “I think the MIT education is kind of lacking in the area of making sure that we’re empowering marginalized communities,” and ensuring that graduates carry those considerations forward into their careers, she said.

    To do that, the Institute should incorporate community engagement and climate justice into its next plan, stressed Caroline White-Nockleby, a graduate student in MIT’s Doctoral Program in History, Anthropology, and Science, Technology, and Society. MIT is “well-positioned” to facilitate energy transition conversations between residents, employers, and local and state officials, she added.

    White-Nockleby noted that places facing climate impacts are often dealing with other economic or environmental challenges. For example, in a western Pennsylvania county where she and other Environmental Solutions Initiative interns researched the economic impacts of coal’s decline, residents are primarily concerned about job losses and tax cuts. “There’s a lot of ways to engage communities around climate change by engaging in the values that matter to those communities,” White-Nockleby said.

    Facing uncertainty head-on

    The forum closed with a panel on how to deal with uncertainty — the topic of a new effort called the “Council on the Uncertain Human Future” at MIT and other universities. Diana Chapman Walsh, a member of the council’s leadership team, said that anxiety and dread can hinder meaningful conversations around climate change. “So our intention for the council was and is to hold a space for a very different conversation than usual,” she explained, “where participants look deeply and personally into the reality of situation as best we can understand it” with others ready to commit to an “honest reckoning” with the climate emergency.

    Desiree Plata, an associate professor of in MIT’s Department of Civil and Environmental Engineering, said her initial skepticism about joining the council went away when she saw other participants become more optimistic over the course of weekly meetings. “People need mechanisms for healing in this time, especially, and that healing can impart motivation,” she said.

    Megan Black, an associate professor of history at MIT, pointed to the massive infrastructure building and conservation work done in the United States in response to the Great Depression as an inspiration for how to deal with present-day uncertainties. “In moments of crisis, people have come together even though it was highly uncertain how it would turn out, and tried to forge a meaningful response,” she said.

    Senior Megan Guenther, echoing that, said that although, “there is a lot of uncertainty regarding what is going on with the climate, there are a ton of opportunities available — really, endless opportunities — for how we can address this issue.”

    In closing remarks, Associate Provost for International Activities Richard Lester highlighted the “whole-of-MIT” approach as integral to its expanding commitment to the climate challenge. “This institution, more than most, has the capacity and therefore the responsibility to contribute” to addressing the climate emergency, he said. “And it seems to me that the question that we should always be asking ourselves is, how can we make our institution stronger and better able to contribute, where we can have the greatest impact?” More

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    Navigating beneath the Arctic ice

    There is a lot of activity beneath the vast, lonely expanses of ice and snow in the Arctic. Climate change has dramatically altered the layer of ice that covers much of the Arctic Ocean. Areas of water that used to be covered by a solid ice pack are now covered by thin layers only 3 feet deep. Beneath the ice, a warm layer of water, part of the Beaufort Lens, has changed the makeup of the aquatic environment.    

    For scientists to understand the role this changing environment in the Arctic Ocean plays in global climate change, there is a need for mapping the ocean below the ice cover.

    A team of MIT engineers and naval officers led by Henrik Schmidt, professor of mechanical and ocean engineering, is trying to understand environmental changes, their impact on acoustic transmission beneath the surface, and how these changes affect navigation and communication for vehicles traveling below the ice.

    “Basically, what we want to understand is how does this new Arctic environment brought about by global climate change affect the use of underwater sound for communication, navigation, and sensing?” explains Schmidt.

    To answer this question, Schmidt traveled to the Arctic with members of the Laboratory for Autonomous Marine Sensing Systems (LAMSS) including Daniel Goodwin and Bradli Howard, graduate students in the MIT-Woods Hole Oceanographic Institution Joint Program in oceanographic engineering.

    With funding from the Office of Naval Research, the team participated in ICEX — or Ice Exercise — 2020, a three-week program hosted by the U.S. Navy, where military personnel, scientists, and engineers work side-by-side executing a variety of research projects and missions.

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    Understanding the Arctic | MIT MechE

    A strategic waterway

    The rapidly changing environment in the Arctic has wide-ranging impacts. In addition to giving researchers more information about the impact of global warming and the effects it has on marine mammals, the thinning ice could potentially open up new shipping lanes and trade routes in areas that were previously untraversable.

    Perhaps most crucially for the U.S. Navy, understanding the altered environment also has geopolitical importance.

    “If the Arctic environment is changing and we don’t understand it, that could have implications in terms of national security,” says Goodwin.

    Several years ago, Schmidt and his colleague Arthur Baggeroer, professor of mechanical and ocean engineering, were among the first to recognize that the warmer waters, part of the Beaufort Lens, coupled with the changing ice composition, impacted how sound traveled in the water.

    To successfully navigate throughout the Arctic, the U.S. Navy and other entities in the region need to understand how these changes in sound propagation affect a vehicle’s ability to communicate and navigate through the water.

    Using an unpiloted, autonomous underwater vehicle (AUV) built by General Dynamics-Mission Systems (GD-MS), and a system of sensors rigged on buoys developed by the Woods Hole Oceanographic Institution, Schmidt and his team, joined by Dan McDonald and Josiah DeLange of GD-MS, set out to demonstrate a new integrated acoustic communication and navigation concept.

    The framework, which was also supported and developed by LAMSS members Supun Randeni, EeShan Bhatt, Rui Chen, and Oscar Viquez, as well as LAMSS alumnus Toby Schneider of GobySoft LLC, would allow vehicles to travel through the water with GPS-level accuracy while employing oceanographic sensors for data collection.

    “In order to prove that you can use this navigational concept in the Arctic, we have to first ensure we fully understand the environment that we’re operating in,” adds Goodwin.

    Understanding the environment belowAfter arriving at the Arctic Submarine Lab’s ice camp last spring, the research team deployed a number of conductivity-temperature-depth probes to gather data about the aquatic environment in the Arctic.

    “By using temperature and salinity as a function of depth, we calculate the sound speed profile. This helps us understand if the AUV’s location is good for communication or bad,” says Howard, who was responsible for monitoring environmental changes to the water column throughout ICEX.

    Because of the way sound bends in water, through a concept known as Snell’s Law, sine-like pressure waves collect in some parts of the water column and disperse in others. Understanding the propagation trajectories is key to predicting good and bad locations for the AUV to operate.  

    To map the areas of the water with optimal acoustic properties, Howard modified the traditional signal-to-noise-ratio (SNR) by using a metric known as the multi-path penalty (MPP), which penalizes areas where the AUV receives echoes of the messages. As a result, the vehicle prioritizes operations in areas with less reverb.

    These data allowed the team to identify exactly where the vehicle should be positioned in the water column for optimal communications which results in accurate navigation.

    While Howard gathered data on how the characteristics of the water impact acoustics, Goodwin focused on how sound is projected and reflected off the ever-changing ice on the surface.

    To get these data, the AUV was outfitted with a device that measured the motion of the vehicle relative to the ice above. That sound was picked up by several receivers attached to moorings hanging from the ice.

    The data from the vehicle and the receivers were then used by the researchers to compute exactly where the vehicle was at a given time. This location information, together with the data Howard gathered on the acoustic environment in the water, offer a new navigational concept for vehicles traveling in the Arctic Sea.

    Protecting the Arctic

    After a series of setbacks and challenges due to the unforgiving conditions in the Arctic, the team was able to successfully prove their navigational concept worked. Thanks to the team’s efforts, naval operations and future trade vessels may be able to take advantage of the changing conditions in the Arctic to maximize navigational accuracy and improve underwater communications.

    “Our work could improve the ability for the U.S. Navy to safely and effectively operate submarines under the ice for extended periods,” Howard says.

    Howard acknowledges that in addition to the changes in physical climate, the geopolitical climate continues to change. This only strengthens the need for improved navigation in the Arctic.

    “The U.S. Navy’s goal is to preserve peace and protect global trade by ensuring freedom of navigation throughout the world’s oceans,” she adds. “The navigational concept we proved during ICEX will serve to help the Navy in that mission.” More

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    Spencer Compton, Karna Morey, Tara Venkatadri, and Lily Zhang named 2021-22 Goldwater Scholars

    MIT students Spencer Compton, Karna Morey, Tara Venkatadri, and Lily Zhang have been selected to receive a Barry Goldwater Scholarship for the 2021-22 academic year. Over 5,000 college students from across the United States were nominated for the scholarships, from which only 410 recipients were selected based on academic merit. 

    The Goldwater scholarships have been conferred since 1989 by the Barry Goldwater Scholarship and Excellence in Education Foundation. These scholarships have supported undergraduates who go on to become leading scientists, engineers, and mathematicians in their respective fields. All of the 2021-22 Goldwater Scholars intend to obtain a doctorate in their area of research, including the four MIT recipients. 

    Spencer Compton

    A junior majoring in computer science and engineering, Compton is set to graduate next year with both his undergraduate and master’s degrees. For Compton, solving advanced problems is as fun as it is challenging — he’s been involved in algorithm competitions since high school, where, on the U.S. team for the 2018 International Olympiad in Informatics, Compton won gold. “I still participate — there’s a college equivalent, the Intercollegiate Programming Contest or ICPC, and I’m on last year’s MIT team that won first in North America,” reports Compton. “We were supposed to represent MIT in the World Finals in Russia last summer, but it’s been postponed due to Covid.” Compton brings his competitive and enthusiastic mindset to his areas of research, including his collaboration on causal inference with the MIT-IBM Watson AI Lab, and his work on approximation algorithms and scheduling with professor of electrical engineering and computer science Ronitt Rubinfeld and postdoc Slobodan Mitrović​.

    In her recommendation letter, Rubinfeld, a member of the Computer Science and Artificial Intelligence Laboratory, spoke at length about Compton’s aptitude as a student but she also left a glowing review as to Compton’s character. “Spencer is extraordinarily pleasant to work with. He is kind and caring when he interacts with younger students. I once had a high school student follow me for a day on which I happened to have a meeting with Spencer ­­— she was so impressed with him that he became a role model for her,” wrote Rubinfeld. Following the completion of his current degrees at MIT, Compton plans to obtain his PhD in computer science, continue his research in algorithms, and teach at the university level.

    Karna Morey

    Morey is a third-year majoring in physics with a minor in Spanish. He got interested in physics while reading Albert Einstein’s biography in the seventh grade, and performed research for two years in high school on gravitational wave physics of a body falling into a black hole. On campus, he has been involved in physics research in theoretical and observational astrophysics, as well as in condensed matter experiments. He recently authored an accepted paper on measuring the lifetime of high-redshift quasars to better understand the ways that supermassive black holes grow. Currently, he is working in the Gedik group, exploring quantum materials using second harmonic generation. Morey plans on pursuing a PhD in physics and one day conduct research at the university level.

    “It was a great experience working with Karna. He was the first student I worked with and he set the bar very high for any future students,” said Christina Eilers, a Pappalardo Fellow in the MIT Department of Physics; Eilers supervised Morey’s research estimating the timescales of supermassive black holes in the early universe and was extremely impressed by his coding skills and confidence as a researcher. Morey is also heavily involved in diversity, equity, and inclusion efforts in the physics department and in the broader field, where he serves as one of the co-chairs of the cross-constituency Physics Values Committee, which seeks to work with department leadership and stakeholders to improve the climate and culture of the physics department. He hopes to make meaningful contributions not only to further scientific discoveries, but also to making science more inclusive.

    Tara Venkatadri

    A fourth-generation engineer and junior at MIT, Venkatadri is following her passion for space exploration, majoring in aeronautical and astronautical engineering with a minor in Earth, atmospheric, and planetary sciences. During her time at MIT, Venkatadri became interested in aerospace structures, pointing out that the unforgiving space environment places unique spacecraft constraints, especially for crewed missions. “As we go deeper into outer space and send humans to other planets, we need to design new methods and materials to ensure the safety of astronauts when pursuing increasingly ambitious space exploration,” she said.

    Her interest in aerospace structures eventually landed her in the lab of Professor Tal Cohen, the Robert N. Noyce Career Development Professor and assistant professor of civil and environmental engineering and mechanical engineering. Venkatadri is trying to understand how adhesive materials deform under torsion in order to use them safely and efficiently in real-world structures, such as spacecraft. There has been increasing interest in adhesives across many industries because they can bond dissimilar materials together without welding and do not concentrate stress on the materials the way mechanical fastenings like bolts and rivets do. In his letter of recommendation, Olivier de Weck, a professor of aeronautics and astronautics and of engineering systems at MIT, cited Venkatadri’s research rigor, academic scholarship, and significant acts of service to the department, noting “without hesitation that Tara is the most impressive undergraduate student I have seen in our department over the last decade.”

    Lily Zhang

    Zhang is a junior double-majoring in Earth, atmospheric, and planetary sciences as well as physics, with minors in public policy and math. Zhang has a passion for climate science, something she’s known since she first viewed Al Gore’s “An Inconvenient Truth” as a child. That passion was encouraged by her father, a professor of meteorology. “He was really passionate about his research and loved his job, which helped me develop my own appreciation for science and academia,” says Zhang. Though her father passed away in 2019, Zhang says he remains a major inspiration on her life.

    At MIT, Zhang is now in the finishing stages of two of her own research projects, including using satellite observations to fill in the historic Halley ozone record with Professor Susan Solomon, the Lee and Geraldine Martin Professor of Environmental Studies in the Department of Earth, Atmospheric and Planetary Sciences. “Lily never ceases to astonish me with her ability to tackle research questions and come up with clever solutions. The Goldwater scholarship is fitting recognition of her enormous potential,” said Solomon. Zhang is thankful to all of her mentors, both past and present, and says that the opportunity to work alongside them and observe their research approaches first-hand has been a dream. After finishing her undergraduate degree, Zhang aims to obtain her PhD and bring her zest for education and research as a professor in climate science.

    The Barry Goldwater Scholarship and Excellence in Education Program was established by Congress in 1986 to honor Senator Barry Goldwater, a soldier and national leader who served the country for 56 years. Awardees receive scholarships of up to $7,500 a year to cover costs related to tuition, room and board, fees, and books. More

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    Electrifying cement with nanocarbon black

    Since its invention several millennia ago, concrete has become instrumental to the advancement of civilization, finding use in countless construction applications — from bridges to buildings. And yet, despite centuries of innovation, its function has remained primarily structural.

    A multiyear effort by MIT Concrete Sustainability Hub (CSHub) researchers, in collaboration with the French National Center for Scientific Research (CNRS), has aimed to change that. Their collaboration promises to make concrete more sustainable by adding novel functionalities — namely, electron conductivity. Electron conductivity would permit the use of concrete for a variety of new applications, ranging from self-heating to energy storage.

    Their approach relies on the controlled introduction of highly conductive nanocarbon materials into the cement mixture. In a paper in Physical Review Materials, they validate this approach while presenting the parameters that dictate the conductivity of the material. 

    Nancy Soliman, the paper’s lead author and a postdoc at the MIT CSHub, believes that this research has the potential to add an entirely new dimension to what is already a popular construction material.

    “This is a first-order model of the conductive cement,” she explains. “And it will bring [the knowledge] needed to encourage the scale-up of these kinds of [multifunctional] materials.” 

    From the nanoscale to the state-of-the-art

    Over the past several decades, nanocarbon materials have proliferated due to their unique combination of properties, chief among them conductivity. Scientists and engineers have previously proposed the development of materials that can impart conductivity to cement and concrete if incorporated within.

    For this new work, Soliman wanted to ensure the nanocarbon material they selected was affordable enough to be produced at scale. She and her colleagues settled on nanocarbon black — a cheap carbon material with excellent conductivity. They found that their predictions of conductivity were borne out.

    “Concrete is naturally an insulative material,” says Soliman, “But when we add nanocarbon black particles, it moves from being an insulator to a conductive material.”

    By incorporating nanocarbon black at just a 4 percent volume of their mixtures, Soliman and her colleagues found that they could reach the percolation threshold, the point at which their samples could carry a current.

    They noticed that this current also had an interesting upshot: It could generate heat. This is due to what’s known as the Joule effect.

    “Joule heating (or resistive heating) is caused by interactions between the moving electrons and atoms in the conductor, explains Nicolas Chanut, a co-author on the paper and a postdoc at MIT CSHub. “The accelerated electrons in the electric field exchange kinetic energy each time they collide with an atom, inducing vibration of the atoms in the lattice, which manifests as heat and a rise of temperature in the material.”

    In their experiments, they found that even a small voltage — as low as 5 volts — could increase the surface temperatures of their samples (approximately 5 cm3 in size) up to 41 degrees Celsius (around 100 degrees Fahrenheit). While a standard water heater might reach comparable temperatures, it’s important to consider how this material would be implemented when compared to conventional heating strategies.

    “This technology could be ideal for radiant indoor floor heating,” explains Chanut. “Usually, indoor radiant heating is done by circulating heated water in pipes that run below the floor. But this system can be challenging to construct and maintain. When the cement itself becomes a heating element, however, the heating system becomes simpler to install and more reliable. Additionally, the cement offers more homogenous heat distribution due to the very good dispersion of the nanoparticles in the material.”

    Nanocarbon cement could have various applications outdoors, as well. Chanut and Soliman believe that if implemented in concrete pavements, nanocarbon cement could mitigate durability, sustainability, and safety concerns. Much of those concerns stem from the use of salt for de-icing.

    “In North America, we see lots of snow. To remove this snow from our roads requires the use of de-icing salts, which can damage the concrete, and contaminate groundwater,” notes Soliman. The heavy-duty trucks used to salt roads are also both heavy emitters and expensive to run.

    By enabling radiant heating in pavements, nanocarbon cement could be used to de-ice pavements without road salt, potentially saving millions of dollars in repair and operations costs while remedying safety and environmental concerns. In certain applications where maintaining exceptional pavement conditions is paramount — such as airport runways — this technology could prove particularly advantageous.       

    Tangled wires

    While this state-of-the-art cement offers elegant solutions to an array of problems, achieving multifunctionality posed a variety of technical challenges. For instance, without a way to align the nanoparticles into a functioning circuit — known as the volumetric wiring — within the cement, their conductivity would be impossible to exploit. To ensure an ideal volumetric wiring, researchers investigated a property known as tortuosity.

    “Tortuosity is a concept we introduced by analogy from the field of diffusion,” explains Franz-Josef Ulm, a leader and co-author on the paper, a professor in the MIT Department of Civil and Environmental Engineering, and the faculty advisor at CSHub. “In the past, it has described how ions flow. In this work, we use it to describe the flow of electrons through the volumetric wire.”

    Ulm explains tortuosity with the example of a car traveling between two points in a city. While the distance between those two points as the crow flies might be two miles, the actual distance driven could be greater due to the circuity of the streets.

    The same is true for the electrons traveling through cement. The path they must take within the sample is always longer than the length of the sample itself. The degree to which that path is longer is the tortuosity.

    Achieving the optimal tortuosity means balancing the quantity and dispersion of carbon. If the carbon is too heavily dispersed, the volumetric wiring will become sparse, leading to high tortuosity. Similarly, without enough carbon in the sample, the tortuosity will be too great to form a direct, efficient wiring with high conductivity.

    Even adding large amounts of carbon could prove counterproductive. At a certain point conductivity will cease to improve and, in theory, would only increase costs if implemented at scale. As a result of these intricacies, they sought to optimize their mixes.

    “We found that by fine-tuning the volume of carbon we can reach a tortuosity value of 2,” says Ulm. “This means the path the electrons take is only twice the length of the sample.”

    Quantifying such properties was vital to Ulm and his colleagues. The goal of their recent paper was not just to prove that multifunctional cement was possible, but that it was also viable for mass production.

    “The key point is that in order for an engineer to pick up things, they need a quantitative model,” explains Ulm. “Before you mix materials together, you want to be able to expect certain repeatable properties. That’s exactly what this paper outlines; it separates what is due to boundary conditions — [extraneous] environmental conditions — from really what is due to the fundamental mechanisms within the material.”

    By isolating and quantifying these mechanisms, Soliman, Chanut, and Ulm hope to provide engineers with exactly what they need to implement multifunctional cement on a broader scale. The path they’ve charted is a promising one — and, thanks to their work, shouldn’t prove too tortuous.

    The research was supported through the Concrete Sustainability Hub by the Portland Cement Association and the Ready Mixed Concrete Research and Education Foundation. More

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    From entrepreneur to climate policy advocate

    Kiara Wahnschafft started her first company at age 16. After her classmate passed away from a drunk driving accident, Wahnschafft couldn’t stop thinking about ways technology could have saved a life. With two other students, she built a prototype for a car key that works only after the driver passes a breathalyzer test. Wahnschafft went on to create a company called SafeStart Technologies, ultimately patenting the product and winning several competitions.

    The experience was Wahnschafft’s introduction to a unique way in which she could improve the lives of those around her. “I was always looking for an artistic outlet as a kid,” she says. “When I discovered programming, it was like I finally had this blank canvas on which to freely create potentially meaningful solutions.”

    Wahnschafft arrived at MIT with the desire to continue pursuing product engineering for social entrepreneurship. She experimented with mechanical engineering classes through MIT D-Lab, a program focused on equitable design and development, and soon found herself surrounded by startups working to alleviate poverty and improve living standards around the world. One company, called Sanergy, stood out to her for its innovative approach toward improving sanitation in urban settlements. Through a PKG Center fellowship, she traveled to Nairobi, Kenya, and interned at Sanergy during Independent Activities Period (IAP) in January, 2020.

    On her first day, Wahnschafft went with co-workers to the settlements where the company’s sanitation units were being built. Seeing the systems and meeting those operating them in person, as well as speaking with new co-workers and friends who had grown up in Nairobi, gave her a much deeper understanding of the challenge. While her engineering work focused on improving sanitation conditions, she learned more about the systemic reasons why settlements were expansive in the first place.

    One of these such issues was job instability. Upon returning to MIT, Wahnschafft dove into an economics research opportunity focused on evaluating a program that teaches Kenyan workers skills needed for digital work. The findings revealed that the program helped to improve wages, employment, and life satisfaction. Wahnschafft then shared her findings with the program’s managers, providing them quantitative reasons to expand their work. The experience introduced her to an evidence-based method for tackling societal challenges.

    Today, Wahnschafft is a junior studying both mechanical engineering and economics. In her career, she aims to help solve what she deems the greatest global challenge of our time: the climate crisis. In learning about and working on the energy transition, Wahnschafft often finds herself leveraging her two disciplines together. For example, she notes, “if we’re proposing the installation of heat pumps, it’s helpful to understand both the technical justification for their energy efficiency and the economic policies required for their widescale adoption.”

    As a researcher in the MIT Environmental Solutions Initiative Rapid Response Group and the MIT Sloan Climate Pathways Project, Wahnschafft has written multiple briefs to inform Massachusetts and federal policymakers, often utilizing MIT climate research to do so. Both now and in the future, her goal is to ensure climate policy is backed by scientific evidence.

    Wahnschafft has also collaborated with the student body and leaders in the administration to improve MIT. As the chief of staff of the Undergraduate Association (UA), the undergraduate student government, she has focused on pulling the student voice into Institute decisions in this unique year, particularly in the area of climate change. She worked with a large group of students, interviewing faculty and other stakeholders in the process, to develop recommendations for climate action at MIT, and is now working with the Institute’s administration to incorporate some of these ideas into MIT’s Plan for Action on Climate Change.

    At a forum about MIT’s Climate Action Plan, Wahnschafft spoke on a panel focused on MIT’s role in the energy transition, and proposed ideas on ways to coordinate the wealth of climate research on campus. After working for a few different MIT climate-focused research centers, she has seen how “MIT has all this amazing research, but it’s often in silos.” After conversations with many faculty and students, she believes that MIT can “exponentially increase its impact” by connecting researchers with each other and with opportunities to influence climate policy.

    Effective communication is also the theme of Wahnschafft’s favorite class, 11.011 (The Art and Science of Negotiation), for which she has served as a teaching assistant. She believes that the course should be an essential part of any MIT student’s curriculum. “I used to think negotiating meant sitting down at the bargaining table to haggle over prices,” she says. “Through the class, you learn that negotiation is so much more: It is practicing empathy and finding common ground. Especially in our polarized country, and especially on issues like climate that are so cross-cutting, we need to open up conversations to reach some mutual understanding.”

    Wahnschafft plans on putting her negotiation skills to the test this summer, when she will be interning in Washington through the MIT Washington Summer Internship Program. She hopes to continue working on climate issues that sit at the intersection of evidence and policy. She feels “It’s going to take time to solve the climate crisis. But my everyday focus will be thinking about if the decisions I’m making are always socially and ethically responsible,” says Wahnschafft.

    “I think that as MIT students, we need to be very thoughtful with where we choose to dedicate our minds. I know so many of my peers will go on to become incredible leaders in all types of important organizations,” she says. “We so often have such incredible opportunities at our fingertips during and after our time at MIT, and that’s amazing. So, we can and should be intentional with which of these we pursue and in the decisions we make as leaders, always considering the implications for our diverse local and global communities.”

    Wahnschafft applies the same principles when looking the the future. “I’ve had the most incredible education and am very often thinking about where I can best apply it to make this world a little better. Applying my education to help combat climate change, one of the greatest global challenges in history, is the way in which I hope to make a difference.” More

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    President Reif urges two-track strategy to achieve global climate goals in 30 years

    Ambitious goals are often called moonshots, but the challenge of addressing climate change will be even more monumental. This “Earthshot,” as MIT President L. Rafael Reif calls it in an op-ed published today in The Boston Globe, is an enormously complex problem with no single right answer, no clear finish line, multiple stakeholders with conflicting priorities, and no central authority empowered to solve it.

    The “super wicked problem” of bringing the global economy to net-zero carbon and adapting to aspects of climate change we can’t prevent will require sustained contributions from every corner of industry, government, academia, philanthropy, and every individual, Reif writes.

    To get there, he argues for pursuing two tracks at once. “On path one, we must go as far as we can, as fast as we can, with the tools we have now. And by tools, I mean not only science and technology, but also policy, infrastructure, behavioral and cultural changes, and more,” he writes.

    “But the fact is,” he adds, “current technology alone will not get us to the 2050 target.”

    Reif thus proposes a path two, involving the creation and deployment of new tools, including science and technology breakthroughs, to approach the many parts of the climate change problem, including aviation, supply chains, agriculture, environmental justice, jobs, and much more.

    To meet this path two challenge, he writes, research universities have a special role: “to spawn ideas that meet the needs of different sectors, and to optimize a system for speeding the mind-to-lab-to-market flow of technological answers, while helping to shape policies and processes to support adoption at scale.”

    For instance, MIT has launched the MIT Climate Grand Challenges, which has led to novel proposals, from capturing carbon dioxide by domesticating fast-growing microbes to developing plasma-assisted technologies as enablers of green aviation.

    Universities can help “tough tech” ideas like these reach the market by creating specialized accelerators. In the MIT ecosystem, The Engine identifies entrepreneurs with bold new-science answers to deep societal problems and connects them with impact investors.

    The Institute is also working to create an innovation marketplace based on collaboration, not competition. For example, the member companies of the new MIT Climate and Sustainability Consortium are working with MIT researchers and with each other to speed the creation, testing, and deployment of practical climate solutions within their production processes, supply chains, and service models.

    “With a super wicked problem, nobody has all the answers. But if individuals and institutions in every part of the economy and society tackle the pieces of the problem within their reach and collaborate with each other, we have a real shot — an Earthshot ­— at preserving a habitable world,” Reif writes. More