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      in Environment

      3 Questions: Boosting concrete’s ability to serve as a natural “carbon sink”

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      Damian Stefaniuk is a postdoc at the MIT Concrete Sustainability Hub (CSHub). He works with MIT professors Franz-Josef Ulm and Admir Masic of the MIT Department of Civil and Environmental Engineering (CEE) to investigate multifunctional concrete. Here, he provides an overview of carbonation in cement-based products, a brief explanation of why understanding carbonation in the life cycle of cement products is key for assessing their environmental impact, and an update on current research to bolster the process.

      Q: What is carbonation and why is it important for thinking about concrete from a life-cycle perspective?

      A: Carbonation is the reaction between carbon dioxide (CO2) and certain compounds in cement-based products, occurring during their use phase and end of life. It forms calcium carbonate (CaCO3) and has important implications for neutralizing the GHG [greenhouse gas] emissions and achieving carbon neutrality in the life cycle of concrete.

      Firstly, carbonation causes cement-based products to act as natural carbon sinks, sequestering CO2 from the air and storing it permanently. This helps mitigate the carbon emissions associated with the production of cement, reducing their overall carbon footprint.

      Secondly, carbonation affects concrete properties. Early-stage carbonation may increase the compressive strength of cement-based products, enhancing their durability and structural performance. However, late-stage carbonation can impact corrosion resistance in steel-reinforced concrete due to reduced alkalinity.

      Considering carbonation in the life cycle of cement-based products is crucial for accurately assessing their environmental impact. Understanding and leveraging carbonation can help industry reduce carbon emissions and maximize carbon sequestration potential. Paying close attention to it in the design process aids in creating durable and corrosion-resistant structures, contributing to longevity and overall sustainability.

      Q: What are some ongoing global efforts to force carbonation?

      A: Some ongoing efforts to force carbonation in concrete involve artificially increasing the amount of CO2 gas present during the early-stage hydration of concrete. This process, known as forced carbonation, aims to accelerate the carbonation reaction and its associated benefits.

      Forced carbonation is typically applied to precast concrete elements that are produced in artificially CO2-rich environments. By exposing fresh concrete to higher concentrations of CO2 during curing, the carbonation process can be expedited, resulting in potential improvements in strength, reduced water absorption, improved resistance to chloride permeability, and improved performance during freeze-thaw. At the same time, it can be difficult to quantify how much CO2 is absorbed and released because of the process.

      These efforts to induce early-stage carbonation through forced carbonation represent the industry’s focus on optimizing concrete performance and environmental impacts. By exploring methods to enhance the carbonation process, researchers and practitioners seek to more efficiently harness its benefits, such as increasing strength and sequestering CO2.

      It is important to note that forced carbonation requires careful implementation and monitoring to ensure desired outcomes. The specific procedures and conditions vary based on the application and intended goals, highlighting the need for expertise and controlled environments.

      Overall, ongoing efforts in forced carbonation contribute to the continuous development of concrete technology, aiming to improve its properties and reduce its carbon footprint throughout the life cycle of the material.

      Q: What is chemically-induced pre-cure carbonation, and what implications does it have?

      A: Chemically-induced pre-cure carbonation (CIPCC) is a method developed by the MIT CSHub to mineralize and permanently store CO2 in cement. Unlike traditional forced carbonation methods, CIPCC introduces CO2 into the concrete mix as a solid powder, specifically sodium bicarbonate. This approach addresses some of the limitations of current carbon capture and utilization technologies.

      The implications of CIPCC are significant. Firstly, it offers convenience for cast-in-place applications, making it easier to incorporate CO2 use in concrete projects. Unlike some other approaches, CIPCC allows for precise control over the quantity of CO2 sequestered in the concrete. This ensures accurate carbonation and facilitates better management of the storage process. CIPCC also builds on previous research regarding amorphous hydration phases, providing an additional mechanism for CO2 sequestration in cement-based products. These phases carbonate through CIPCC, contributing to the overall carbon sequestration capacity of the material.

      Furthermore, early-stage pre-cure carbonation shows promise as a pathway for concrete to permanently sequester a controlled and precise quantity of CO2. Our recent paper in PNAS Nexus suggests that it could theoretically offset at least 40 percent of the calcination emissions associated with cement production, when anticipating advances in the lower-emissions production of sodium bicarbonate. We also found that up to 15 percent of cement (by weight) could be substituted with sodium bicarbonate without compromising the mechanical performance of a given mix. Further research is needed to evaluate long-term effects of this process to explore the potential life-cycle savings and impacts of carbonation.

      CIPCC offers not only environmental benefits by reducing carbon emissions, but also practical advantages. The early-stage strength increase observed in real-world applications could expedite construction timelines by allowing concrete to reach its full strength faster.

      Overall, CIPCC demonstrates the potential for more efficient and controlled CO2 sequestration in concrete. It represents an important development in concrete sustainability, emphasizing the need for further research and considering the material’s life-cycle impacts.

      This research was carried out by MIT CSHub, which is sponsored by the Concrete Advancement Foundation and the Portland Cement Association. More

    • 138 Shares129 Views

      in Energy

      3 Questions: What’s it like winning the MIT $100K Entrepreneurship Competition?

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      Solar power plays a major role in nearly every roadmap for global decarbonization. But solar panels are large, heavy, and expensive, which limits their deployment. But what if solar panels looked more like a yoga mat?

      Such a technology could be transported in a roll, carried to the top of a building, and rolled out across the roof in a matter of minutes, slashing installation costs and dramatically expanding the places where rooftop solar makes sense.

      That was the vision laid out by the MIT spinout Active Surfaces as part of the winning pitch at this year’s MIT $100K Entrepreneurship Competition, which took place May 15. The company is leveraging materials science and manufacturing innovations from labs across MIT to make ultra-thin, lightweight, and durable solar a reality.

      The $100K is one of MIT’s most visible entrepreneurship competitions, and past winners say the prize money is only part of the benefit that winning brings to a burgeoning new company. MIT News sat down with Active Surface founders Shiv Bhakta, a graduate student in MIT’s Leaders for Global Operations dual-degree program within the MIT Sloan School of Management and Department of Civil and Environmental Engineering, and Richard Swartwout SM ’18 PhD ’21, an electrical engineering and computer science graduate and former Research Laboratory of Electronics postdoc and MIT.nano innovation fellow, to learn what the last couple of months have been like since they won.

      Q: What is Active Surfaces’ solution, and what is its potential?

      Bhakta: We’re commercializing an ultrathin film, flexible solar technology. Solar is one of the most broadly distributed resources in the world, but access is limited today. It’s heavy — it weighs 50 to 60 pounds a panel — it requires large teams to move around, and the form factor can only be deployed in specific environments.

      Our approach is to develop a solar technology for the built environment. In a nutshell, we can create flexible solar panels that are as thin as paper, just as efficient as traditional panels, and at unprecedented cost floors, all while being applied to any surface. Same area, same power. That’s our motto.

      When I came to MIT, my north star was to dive deeper in my climate journey and help make the world a better, greener place. Now, as we build Active Surfaces, I’m excited to see that dream taking shape. The prospect of transforming any surface into an energy source, thereby expanding solar accessibility globally, holds the promise of significantly reducing CO2 emissions at a gigaton scale. That’s what gets me out of bed in the morning.

      Swartwout: Solar and a lot of other renewables tend to be pretty land-inefficient. Solar 1.0 is using low hanging fruit: cheap land next to easy interconnects and new buildings designed to handle the weight of current panels. But as we ramp up solar, those things will run out. We need to utilize spaces and assets better. That’s what I think solar 2.0 will be: urban PV deployments, solar that’s closer to demand, and integrated into the built environment. These next-generation use cases aren’t just a racking system in the middle of nowhere.

      We’re going after commercial roofs, which would cover most [building] energy demand. Something like 80-90 percent of building electricity demands in the space can be met by rooftop solar.

      The goal is to do the manufacturing in-house. We use roll-to-roll manufacturing, so we can buy tons of equipment off the shelf, but most roll-to-roll manufacturing is made for things like labeling and tape, and not a semiconductor, so our plan is to be the core of semiconductor roll-to-roll manufacturing. There’s never been roll-to-roll semiconductor manufacturing before.

      Q: What have the last few months been like since you won the $100K competition?

      Bhakta: After winning the $100K, we’ve gotten a lot of inbound contact from MIT alumni. I think that’s my favorite part about the MIT community — people stay connected. They’ve been congratulating us, asking to chat, looking to partner, deploy, and invest.

      We’ve also gotten contacted by previous $100K competition winners and other startups that have spun out of MIT that are a year or two or three ahead of us in terms of development. There are a lot of startup scaling challenges that other startup founders are best equipped to answer, and it’s been huge to get guidance from them.

      We’ve also gotten into top accelerators like Cleantech Open, Venture For Climatetech, and ACCEL at Greentown Labs. We also onboarded two rockstar MIT Sloan interns for the summer. Now we’re getting to the product-development phase, building relationships with potential pilot partners, and scaling up the area of our technology.      

      Swartwout: Winning the $100K competition was a great point of validation for the company, because the judges themselves are well known in the venture capital community as well as people who have been in the startup ecosystem for a long time, so that has really propelled us forward. Ideally, we’ll be getting more MIT alumni to join us to fulfill this mission.

      Q: What are your plans for the next year or so?

      Swartwout: We’re planning on leveraging open-access facilities like those at MIT.nano and the University of Massachusetts Amherst. We’re pretty focused now on scaling size. Out of the lab, [the technology] is a 4-inch by 4-inch solar module, and the goal is to get up to something that’s relevant for the industry to offset electricity for building owners and generate electricity for the grid at a reasonable cost.

      Bhakta: In the next year, through those open-access facilities, the goal is to go from 100-millimeter width to 300-millimeter width and a very long length using a roll-to-roll manufacturing process. That means getting through the engineering challenges of scaling technology and fine tuning the performance.

      When we’re ready to deliver a pilotable product, it’s my job to have customers lined up ready to demonstrate this works on their buildings, sign longer term contracts to get early revenue, and have the support we need to demonstrate this at scale. That’s the goal. More

    • 113 Shares99 Views

      in Environment

      Helping the transportation sector adapt to a changing world

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      After graduating from college, Nick Caros took a job as an engineer with a construction company, helping to manage the building of a new highway bridge right near where he grew up outside of Vancouver, British Columbia.  

      “I had a lot of friends that would use that new bridge to get to work,” Caros recalls. “They’d say, ‘You saved me like 20 minutes!’ That’s when I first realized that transportation could be a huge benefit to people’s lives.”

      Now a PhD candidate in the Urban Mobility Lab and the lead researcher for the MIT Transit Research Consortium, Caros works with seven transit agencies across the country to understand how workers’ transportation needs have changed as companies have adopted remote work policies.

      “Another cool thing about working on transportation is that everybody, even if they don’t engage with it on an academic level, has an opinion or wants to talk about it,” says Caros. “As soon as I mention I’ve worked with the T, they have something they want to talk about.”

      Caros is drawn to projects with social impact beyond saving his friends a few minutes during their commutes. He sees public transportation as a crucial component in combating climate change and is passionate about identifying and lowering the psychological barriers that prevent people around the world from taking advantage of their local transit systems.

      “The more I’ve learned about public transportation, the more I’ve come to realize it will play an essential part in decarbonizing urban transportation,” says Caros. “I want to continue working on these kinds of issues, like how we can make transportation more sustainable or promoting public transportation in places where it doesn’t exist or can be improved.”

      Caros says he doesn’t have a “transportation origin story,” like some of his peers who grew up in urban centers with robust public transit systems. As a child growing up in the Vancouver suburbs, he always enjoyed the outdoors, which were as close as his backyard. He chose to study engineering as an undergraduate at the University of British Columbia, fascinated by the hydroelectric dams that supply Vancouver with most of its power. But after two projects with the construction company, the second of which took him to Maryland to work on a fossil fuel project, he decided he needed a change.

      Not quite sure what he wanted to do next, Caros sought out the shortest master’s program he could find that interested him. That ended up being an 18-month master’s program in transportation planning and engineering at New York University. Initially intending to pursue the course-based program, Caros was soon offered the chance to be a research assistant in NYU’s Behavioral Urban Informatics, Logistics, and Transport Laboratory with Professor Joseph Chow. There, he worked to model an experimental transportation system of modular self-driving cars that could link and unlink with each other while in motion.

      “It was this really futuristic stuff,” says Caros. “It turned out to be a really cool project to work on because it’s kind of rare to have a blank-slate problem to try and solve. A lot of transportation engineering problems have largely been solved. We know how to make efficient and sustainable transportation systems; it’s just finding the political support and encouraging behavioral change that remains a challenge.”

      At NYU, Caros fell in love with research and the field of transportation. Later, he was drawn to MIT by its interdisciplinary PhD program that spans both urban studies and planning and civil engineering and the opportunity to work with Professor Jinhua Zhao.

      His research focuses on identifying “third places,” locations where some people go if their job gives them the flexibility to work remotely. Previously, transportation needs revolved around office spaces, typically located in city centers. With more people working from home, the first assumption is that transportation needs would decrease. But that’s not what Caros has found.

      “One major finding from our research is that people have changed where they’re going when they go to work,” says Caros. “A lot of people are working from home, but some are also working in other places, like coffee shops or co-working spaces. And these third places are not evenly distributed in Boston.”

      Identifying the concentration of these third places and what locations would benefit from them is the core of Caros’ dissertation. He’s building an algorithm that identifies ideal locations to build more shared workplaces based on both economic and social factors. Caros seeks to answer how you can minimize travel time across the board while leaving room for the spontaneous social interactions that drive a city’s productivity. His research is sponsored by seven of the largest transit agencies in the United States, who are members of the MIT Transit Research Consortium. Rather than a single agency sponsoring a single specific project, funding is pooled to tackle projects that address general topics that can apply to multiple cities.

      These kinds of problems require a multidisciplinary approach that appeals to Caros. Even when diving into the technical details of a solution, he always keeps the bigger picture in mind. He is certain that changing people’s views of public transportation will be crucial in the fight against climate change.

      “A lot of it is not necessarily engineering, but understanding what the motivations of people are,” says Caros. “Transportation is a leading sector for carbon emissions in the U.S., and so figuring out what makes people tick and how you can get them to ride public transit more, for example, would help to reduce the overall carbon cost.”

      Following the completion of his degree, Caros will join the Organization for Economic Cooperation and Development. He already spent six months at its Paris headquarters as an intern during a leave from MIT, something his lab encourages all of its students to do. Last fall, he worked on drafting policy guidelines for new mobility services such as vehicle-share scooters, and addressing transportation equity issues in Ghana. Plus, living in Paris gave him the opportunity to practice his French. Growing up in Canada, he attended a French immersion school, and his internship offered his first opportunity to use the language outside of an academic context.

      Looking forward, Caros hopes to keep tackling projects that promote sustainable public transportation. There is an urgency in getting ahead of the curve, especially in cities experiencing rapid growth.

      “You kind of get locked in,” says Caros. “It becomes much harder to build sustainable transportation systems after the fact. But it’s really just a geometry problem. Trains and buses are a way more efficient way to move people using the same amount of space as private cars.” More

    • 125 Shares189 Views

      in Energy

      Understanding boiling to help the nuclear industry and space missions

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      To launch extended missions in space, the National Aeronautics and Space Administration (NASA) is borrowing a page from the nuclear engineering industry: It is trying to understand how boiling works.

      Planning for long-term missions has NASA researching ways of packing the least amount of cryogenic fuel possible for efficient liftoff. One potential solution is to refuel the rocket in space using fuel depots placed in low Earth orbits. This way, the spacecraft can carry the lightest fuel load — enough to reach the low Earth orbit to refuel as necessary and complete the mission. But refueling in space requires a thorough knowledge of cryogenic fuels.

      “We [need to understand] how boiling of cryogens behaves in microgravity conditions [encountered in space],” says Florian Chavagnat, a sixth-year doctoral candidate in the Department of Nuclear Science and Engineering (NSE). After all, understanding how cryogens boil in space is critical to NASA’s fuel management strategy. The vast majority of studies on boiling evaluate fluids that boil at high temperatures, which doesn’t necessarily apply to cryogens. Under the advisement of Matteo Bucci and Emilio Baglietto, Chavagnat is working on NASA-sponsored research about cryogens and the way the lack of buoyancy in space affects boiling.

      A childhood spent tinkering

      A deep understanding of engineering and physical phenomena is exactly what Chavagnat developed growing up in Boussy-Saint-Antoine, a suburb of Paris, with parents who worked for SNCF, the national state-owned rail company. Chavagnat remembers discussing the working of trains and motors with his engineer dad and building a variety of balsa-wood models. One of his memorable projects was a sailboat propelled by a motor from an electric toothbrush.

      By the time he was a teenager, Chavagnat received a metal lathe as a gift. His tinkering became an obsession; a compressed air engine was a favorite project. Soon his parents’ small shed, meant for gardening, became a factory, Chavagnat recalls, laughing.

      A lifelong love of math and physics propelled a path to the National Institute of Applied Science in Rouen, Normandy, where Chavagnat studied energetics and propulsion as part of a five-year engineering program. In his final year, Chavagnat studied atomic engineering from INSTN Paris-Saclay, part of the esteemed French Alternative Energies and Atomic Energy Commission (CEA).

      The final year of studies at CEA required a six-month-long internship, which traditionally sets the course for a job. Chavagnat decided to take a chance and apply for an internship at MIT NSE instead, knowing his future course might be uncertain. “I didn’t take a lot of risk in my life, but this one was a big risk,” Chavagnat says. The gamble paid off: Chavagnat won the internship with Charles Forsberg, which paved the way for his admission as a doctoral student. “I selected MIT because it has always been my dream school,” Chavagnat says. He also enjoyed the idea of challenging himself to improve his English-speaking skills.

      A love of physics and heat transfer

      Chavagnat loves physics — “if I can study any problem in physics, I’d be happy” he says — which led him to working on heat transfer, more specifically on boiling heat transfer. His early doctoral research focused on transient boiling in nuclear reactors, part of which has been published in the International Journal of Heat and Mass Transfer.

      Chavagnat’s research targets a specific kind of nuclear reactor called a material test reactor (MTR). Nuclear scientists use MTRs to understand how materials used in plant operations might behave under long-term use. Densely packed nuclear fuel, running at high power, simulates long-term effects using a very intense neutron flux.

      To prevent failure, operators limit reactor temperature by flowing very cold water at high velocity. When reactor heat power increases uncontrollably, the piped water begins to boil. Boiling works to prevent meltdown by altering neutron moderation and extracting heat from the fuel. “[Unfortunately], that only works until you reach a certain heat flux at the fuel cladding, after which the efficiency completely drops,” Chavagnat says. Once the critical heat flux is reached, water vapor starts to blanket and insulate the fuel elements, leading to rapidly rising cladding temperatures and potential burnout.

      The key is to figure out the behavior of maximum boiling heat flux under routine MTR conditions — cold water, high flow velocity, and narrow spacing between the fuel elements.

      Study of cryogenic boiling

      Boiling continues to occupy center stage as Chavagnat pursues the question for NASA. Cryogens boil at very low temperatures, so the question of how to prevent fuel loss from routine space-based operations is an important one to answer.

      Chavagnat is studying how boiling would behave under reduced or absent buoyancy, which are the conditions cryogenic rocket fuel will encounter in space.

      To reproduce space-like conditions on Earth, buoyancy can be modified without going to space. Chavagnat is manipulating the inclination of the boiling surface — placing it upside down is an example — such that buoyancy does not do what it usually does: help bubbles break away from the surface. He is also performing boiling experiments in parabolic flights to simulate microgravity, similar to what is experienced aboard the International Space Station.

      Chavagnat designed and built equipment which can perform both methods with minimum changes. “We observed nitrogen boiling on our surface by imaging it using two high-speed video cameras,” he says. The experiment was approved to go on board the parabolic flights operated by Zero-G, a company that operates weightless flights. The team successfully completed four parabolic flights in 2022.

      “Flying an experiment aboard an aircraft and operating it in microgravity is an incredible experience, but is challenging,” Chavagnat says, “Knowing the details the experiment is a must, but other skills are quite useful — in particular, working as a team, being able to manage high stress levels, and being able to work while being motion-sick.” Another challenge is that the majority of issues cannot be fixed once aboard, as aircraft pilots perform the parabola (each lasting 17 seconds) almost back-to-back.

      Throughout his research at MIT, Chavagnat has been captivated by how complex a simple phenomenon like boiling can truly be. “In your childhood, you have a certain idea of how boiling looks, relatively slow bubbles that you can see with the naked eye,” he says, “but you don’t realize the complexity until you see it with your own eyes.”

      In his infrequent spare time, Chavagnat plays soccer with the NSE’s team, the Atom Smashers. The group meets only five times a semester so it’s a low-key commitment, says Chavagnat who spends most of his time at the lab. “I am doing mostly experiments at MIT; it turns out the skills I learned in my shed when I was 15 are actually quite useful here,” he laughs. More

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      in Environment

      Four researchers with MIT ties earn 2023 Schmidt Science Fellowships

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      Four researchers with ties to MIT have been named Schmidt Science Fellows this year. Lillian Chin ’17, SM ’19; Neil Dalvie PD ’22, PhD ’22; Suong Nguyen, and Yirui Zhang SM ’19, PhD ’23 are among the 32 exceptional early-career scientists worldwide chosen to receive the prestigious fellowships.

      “History provides powerful examples of what happens when scientists are given the freedom to ask big questions which can achieve real breakthroughs across disciplines,” says Wendy Schmidt, co-founder of Schmidt Futures and president of the Schmidt Family Foundation. “Schmidt Science Fellows are tackling climate destruction, discovering new drugs against disease, developing novel materials, using machine learning to understand the drivers of human health, and much more. This new cohort will add to this legacy in applying scientific discovery to improve human health and opportunity, and preserve and restore essential planetary systems.”

      Schmidt Futures is a philanthropic initiative that brings talented people together in networks to prove out their ideas and solve hard problems in science and society. Schmidt Science Fellows receive a stipend of $100,000 a year for up to two years of postdoctoral research in a discipline different from their PhD at a world-leading lab anywhere across the globe.

      Lillian Chin ’17, SM ’19 is currently pursuing her PhD in the Department of Electrical Engineering and Computer Science. Her research focuses on creating new materials for robots. By designing the geometry of a material, Chin creates new “meta-materials” that have different properties from the original. Using this technique, she has created robot balls that dramatically expand in volume and soft grippers that can work in dangerous environments. All of these robots are built out of a single material, letting the researchers 3D print them with extra internal features like channels. These channels help to measure the deformation of metamaterials, enabling Chin and her collaborators to create robots that are strong, can move, and sense their own shape, like muscles do.

      “I feel very honored to have been chosen for this fellowship,” says Chin. “I feel like I proposed a very risky pivot, since my background is only in engineering, with very limited exposure to neuroscience. I’m very excited to be given the opportunity to learn best practices for interacting with patients and be able to translate my knowledge from robotics to biology.”

      With the Schmidt Fellowship, Chin plans to pursue new frontiers for custom materials with internal sensors, which can measure force and deformation and can be placed anywhere within the material. “I want to use these materials to make tools for clinicians and neuroscientists to better understand how humans touch and grasp objects around them,” says Chin. “I’m especially interested in seeing how my materials could help in diagnosis motor-related diseases or improve rehab outcomes by providing the patient with feedback. This will help me create robots that have a better sense of touch and learn how to move objects around like humans do.”

      Neil Dalvie PD ’22, PhD ’22 is a graduate of the Department of Chemical Engineering, where he worked with Professor J. Christopher Love on manufacturing of therapeutic proteins. Dalvie developed molecular biology techniques for manufacturing high-quality proteins in yeast, which enables rapid testing of new products and low-cost manufacturing and large scales. During the pandemic, he led a team that applied these learnings to develop a Covid-19 vaccine that was deployed in multiple low-income countries. After graduating, Dalvie wanted to apply the precision biological engineering that is routinely deployed in medicinal manufacturing to other large-scale bioprocesses.

      “It’s rare for scientists to cross large technical gaps after so many years of specific training to get a PhD — you get comfy being an expert in your field,” says Dalvie. “I was definitely intimidated by the giant leap from vaccine manufacturing to the natural rock cycle. The fellowship has allowed me to dive into the new field by removing immediate pressure to publish or find my next job. I am excited for what commonalities we will find between biomanufacturing and biogeochemistry.”

      As a Schmidt Science Fellow, Dalvie will work with Professor Pamela Silver at Harvard Medical School on engineering microorganisms for enhanced rock weathering and carbon sequestration to combat climate change. They are applying modern molecular biology to enhance natural biogeochemical processes at gigaton scales.

      Suong (Su) Nguyen, a postdoctoral researcher in Professor Jeremiah Johnson’s lab in the Department of Chemistry, earned her PhD from Princeton University, where she developed light-driven, catalytic methodologies for organic synthesis, biomass valorization, plastic waste recycling, and functionalization of quantum sensing materials.

      As a Schmidt Science fellow, Nguyen will pivot from organic chemistry to nanomaterials. Biological systems are able to synthesize macromolecules with precise structure essential for their biological function. Scientists have long dreamed of achieving similar control over synthetic materials, but existing methods are inefficient and limited in scope. Nguyen hopes to develop new strategies to achieve such high level of control over the structure and properties of nanomaterials and explore their potential for use in therapeutic applications.

      “I feel extremely honored and grateful to receive the Schmidt Science Fellowship,” says Nguyen. “The fellowship will provide me with a unique opportunity to engage with scientists from a very wide range of research backgrounds. I believe this will significantly shape the research objectives for my future career.”

      Yirui Zhang SM ’19, PhD ’22 is a graduate of the Department of Mechanical Engineering. Zhang’s research focuses on electrochemical energy storage and conversion, including lithium-ion batteries and electrocatalysis. She has developed in situ spectroscopy and electrochemical methods to probe the electrode-electrolyte interface, understand the interfacial molecular structures, and unravel the fundamental thermodynamics and kinetics of (electro)chemical reactions in energy storage. Further, she has leveraged the physical chemistry of liquids and tuned the molecular structures at the interface to improve the stability and kinetics of electrochemical reactions. 

      “I am honored and thrilled to have been named a Schmidt Science Fellow,” says Zhang. “The fellowship will not only provide me with the unique opportunity to broaden my scientific perspectives and pursue pivoting research, but also create a lifelong network for us to collaborate across diverse fields and become scientific and societal thought leaders. I look forward to pushing the boundaries of my research and advancing technologies to tackle global challenges in energy storage and health care with interdisciplinary efforts!”

      As a Schmidt Science Fellow, Zhang will work across disciplines and pivot to biosensing. She plans to combine spectroscopy, electrokinetics, and machine learning to develop a fast and cost-effective technique for monitoring and understanding infectious disease. The innovations will benefit next-generation point-of-care medical devices and wastewater-based epidemiology to provide timely diagnosis and help protect humans against deadly infections and antimicrobial resistance. More

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      in Environment

      Exploring the bow shock and beyond

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      For most people, the night sky conjures a sense of stillness, an occasional shooting star the only visible movement. A conversation with Rishabh Datta, however, unveils the supersonic drama crashing above planet Earth. The PhD candidate has focused his recent study on the plasma speeding through space, flung from sources like the sun’s corona and headed toward Earth, halted abruptly by colliding with the planet’s magnetosphere. The resulting shock wave is similar to the “bow shock” that forms around the nose cone of a supersonic jet, which manifests as the familiar sonic boom.

      The bow shock phenomenon has been well studied. “It’s probably one of the things that’s keeping life alive,” says Datta, “protecting us from the solar wind.” While he feels the magnetosphere provides “a very interesting space laboratory,” Datta’s main focus is, “Can we create this high-energy plasma that is moving supersonically in a laboratory, and can we study it? And can we learn things that are hard to diagnose in an astrophysical plasma?”

      Datta’s research journey to the bow shock and beyond began when he joined a research program for high school students at the National University Singapore. Tasked with culturing bacteria and measuring the amount of methane they produced in a biogas tank, Datta found his first research experience “quite nasty.”

      “I was working with chicken manure, and every day I would come home smelling completely awful,” he says.

      As an undergraduate at Georgia Tech, Datta’s interests turned toward solar power, compelled by a new technology he felt could generate sustainable energy. By the time he joined MIT’s Department of Mechanical Engineering, though, his interests had morphed into researching the heat and mass transfer from airborne droplets. After a year of study, he felt the need to go in a yet another direction.

      The subject of astrophysical plasmas had recently piqued his interest, and he followed his curiosity to Department of Nuclear Science and Engineering Professor Nuno Loureiro’s introductory plasma class. There he encountered Professor Jack Hare, who was sitting in on the class and looking for students to work with him.

      “And that’s how I ended up doing plasma physics and studying bow shocks,” he says, “a long and circuitous route that started with culturing bacteria.”

      Gathering measurements from MAGPIE

      Datta is interested in what he can learn about plasma from gathering measurements of a laboratory-created bow shock, seeking to verify theoretical models. He uses data already collected from experiments on a pulsed-power generator known as MAGPIE (the Mega-Ampere Generator of Plasma Implosion Experiments), located at Imperial College, London. By observing how long it takes a plasma to reach an obstacle, in this case a probe that measures magnetic fields, Datta was able to determine its velocity.   

      With the velocity established, an interferometry system was able to provide images of the probe and the plasma around it, allowing Datta to characterize the structure of the bow shock.

      “The shape depends on how fast sound waves can travel in a plasma,” says Datta. “And this ‘sound speed’ depends on the temperature.”

      The interdependency of these characteristics means that by imaging a shock it’s possible to determine temperature, sound speed, and other measurements more easily and cheaply than with other methods.

      “And knowing more about your plasma allows you to make predictions about, for example, electrical resistivity, which can be important for understanding other physics that might interest you,” says Datta, “like magnetic reconnection.”

      This phenomenon, which controls the evolution of such violent events as solar flares, coronal mass ejections, magnetic storms that drive auroras, and even disruptions in fusion tokamaks, has become the focus of his recent research. It happens when opposing magnetic fields in a plasma break and then reconnect, generating vast quantities of heat and accelerating the plasma to high velocities.

      Onward to Z

      Datta travels to Sandia National Laboratories in Albuquerque, New Mexico, to work on the largest pulsed power facility in the world, informally known as “the Z machine,” to research how the properties of magnetic reconnection change when a plasma emits strong radiation and cools rapidly.

      In future years, Datta will only have to travel across Albany Street on the MIT campus to work on yet another machine, PUFFIN, currently being built at the Plasma Science and Fusion Center (PSFC). Like MAGPIE and Z, PUFFIN is a pulsed power facility, but with the ability to drive the current 10 times longer than other machines, opening up new opportunities in high-energy-density laboratory astrophysics.

      Hare, who leads the PUFFIN team, is pleased with Datta’s increasing experience.

      “Working with Rishabh is a real pleasure,” he says, “He has quickly learned the ins and outs of experimental plasma physics, often analyzing data from machines he hasn’t even yet had the chance to see! While we build PUFFIN it’s really useful for us to carry out experiments at other pulsed-power facilities worldwide, and Rishabh has already written papers on results from MAGPIE, COBRA at Cornell in Ithaca, New York, and the Z Machine.”

      Pursuing climate action at MIT

      Hand-in-hand with Datta’s quest to understand plasma is his pursuit of sustainability, including carbon-free energy solutions. A member of the Graduate Student Council’s Sustainability Committee since he arrived in 2019, he was heartened when MIT, revising their climate action plan, provided him and other students the chance to be involved in decision-making. He led focus groups to provide graduate student input on the plan, raising issues surrounding campus decarbonization, the need to expand hiring of early-career researchers working on climate and sustainability, and waste reduction and management for MIT laboratories.

      When not focused on bringing astrophysics to the laboratory, Datta sometimes experiments in a lab closer to home — the kitchen — where he often challenges himself to duplicate a recipe he has recently tried at a favorite restaurant. His stated ambition could apply to his sustainability work as well as to his pursuit of understanding plasma.

      “The goal is to try and make it better,” he says. “I try my best to get there.”

      Datta’s work has been funded, in part, by the National Science Foundation, National Nuclear Security Administration, and the Department of Energy. More

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      in Environment

      MIT PhD students honored for their work to solve critical issues in water and food

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      In 2017, the Abdul Latif Jameel Water and Food Systems Lab (J-WAFS) initiated the J-WAFS Fellowship Program for outstanding MIT PhD students working to solve humankind’s water-related challenges. Since then, J-WAFS has awarded 18 fellowships to students who have gone on to create innovations like a pump that can maximize energy efficiency even with changing flow rates, and a low-cost water filter made out of sapwood xylem that has seen real-world use in rural India. Last year, J-WAFS expanded eligibility to students with food-related research. The 2022 fellows included students working on micronutrient deficiency and plastic waste from traditional food packaging materials. 

      Today, J-WAFS has announced the award of the 2023-24 fellowships to Gokul Sampath and Jie Yun. A doctoral student in the Department of Urban Studies and planning, Sampath has been awarded the Rasikbhai L. Meswani Fellowship for Water Solutions, which is supported through a generous gift from Elina and Nikhil Meswani and family. Yun, who is in the Department of Civil and Environmental Engineering, received a J-WAFS Fellowship for Water and Food Solutions, which is funded by the J-WAFS Research Affiliate Program. Currently, Xylem, Inc. and GoAigua are J-WAFS’ Research Affiliate companies. A review committee comprised of MIT faculty and staff selected Sampath and Yun from a competitive field of outstanding graduate students working in water and food who were nominated by their faculty advisors. Sampath and Yun will receive one academic semester of funding, along with opportunities for networking and mentoring to advance their research.

      “Both Yun and Sampath have demonstrated excellence in their research,” says J-WAFS executive director Renee J. Robins. “They also stood out in their communication skills and their passion to work on issues of agricultural sustainability and resilience and access to safe water. We are so pleased to have them join our inspiring group of J-WAFS fellows,” she adds.

      Using behavioral health strategies to address the arsenic crisis in India and Bangladesh

      Gokul Sampath’s research centers on ways to improve access to safe drinking water in developing countries. A PhD candidate in the International Development Group in the Department of Urban Studies and Planning, his current work examines the issue of arsenic in drinking water sources in India and Bangladesh. In Eastern India, millions of shallow tube wells provide rural households a personal water source that is convenient, free, and mostly safe from cholera. Unfortunately, it is now known that one-in-four of these wells is contaminated with naturally occurring arsenic at levels dangerous to human health. As a result, approximately 40 million people across the region are at elevated risk of cancer, stroke, and heart disease from arsenic consumed through drinking water and cooked food. 

      Since the discovery of arsenic in wells in the late 1980s, governments and nongovernmental organizations have sought to address the problem in rural villages by providing safe community water sources. Yet despite access to safe alternatives, many households still consume water from their contaminated home wells. Sampath’s research seeks to understand the constraints and trade-offs that account for why many villagers don’t collect water from arsenic-safe government wells in the village, even when they know their own wells at home could be contaminated.

      Before coming to MIT, Sampath received a master’s degree in Middle East, South Asian, and African studies from Columbia University, as well as a bachelor’s degree in microbiology and history from the University of California at Davis. He has long worked on water management in India, beginning in 2015 as a Fulbright scholar studying households’ water source choices in arsenic-affected areas of the state of West Bengal. He also served as a senior research associate with the Abdul Latif Jameel Poverty Action Lab, where he conducted randomized evaluations of market incentives for groundwater conservation in Gujarat, India. Sampath’s advisor, Bishwapriya Sanyal, the Ford International Professor of Urban Development and Planning at MIT, says Sampath has shown “remarkable hard work and dedication.” In addition to his classes and research, Sampath taught the department’s undergraduate Introduction to International Development course, for which he received standout evaluations from students.

      This summer, Sampath will travel to India to conduct field work in four arsenic-affected villages in West Bengal to understand how social influence shapes villagers’ choices between arsenic-safe and unsafe water sources. Through longitudinal surveys, he hopes to connect data on the social ties between families in villages and the daily water source choices they make. Exclusionary practices in Indian village communities, especially the segregation of water sources on the basis of caste and religion, has long been suspected to be a barrier to equitable drinking water access in Indian villages. Yet despite this, planners seeking to expand safe water access in diverse Indian villages have rarely considered the way social divisions within communities might be working against their efforts. Sampath hopes to test whether the injunctive norms enabled by caste ties constrain villagers’ ability to choose the safest water source among those shared within the village. When he returns to MIT in the fall, he plans to dive into analyzing his survey data and start work on a publication.

      Understanding plant responses to stress to improve crop drought resistance and yield

      Plants, including crops, play a fundamental role in Earth’s ecosystems through their effects on climate, air quality, and water availability. At the same time, plants grown for agriculture put a burden on the environment as they require energy, irrigation, and chemical inputs. Understanding plant/environment interactions is becoming more and more important as intensifying drought is straining agricultural systems. Jie Yun, a PhD student in the Department of Civil and Environmental Engineering, is studying plant response to drought stress in the hopes of improving agricultural sustainability and yield under climate change.  Yun’s research focuses on genotype-by-environment interaction (GxE.) This relates to the observation that plant varieties respond to environmental changes differently. The effects of GxE in crop breeding can be exploited because differing environmental responses among varieties enables breeders to select for plants that demonstrate high stress-tolerant genotypes under particular growing conditions. Yun bases her studies on Brachypodium, a model grass species related to wheat, oat, barley, rye, and perennial forage grasses. By experimenting with this species, findings can be directly applied to cereal and forage crop improvement. For the first part of her thesis, Yun collaborated with Professor Caroline Uhler’s group in the Department of Electrical Engineering and Computer Science and the Institute for Data, Systems, and Society. Uhler’s computational tools helped Yun to evaluate gene regulatory networks and how they relate to plant resilience and environmental adaptation. This work will help identify the types of genes and pathways that drive differences in drought stress response among plant varieties.  David Des Marais, the Cecil and Ida Green Career Development Professor in the Department of Civil and Environmental Engineering, is Yun’s advisor. He notes, “throughout Jie’s time [at MIT] I have been struck by her intellectual curiosity, verging on fearlessness.” When she’s not mentoring undergraduate students in Des Marais’ lab, Yun is working on the second part of her project: how carbon allocation in plants and growth is affected by soil drying. One result of this work will be to understand which populations of plants harbor the necessary genetic diversity to adapt or acclimate to climate change. Another likely impact is identifying targets for the genetic improvement of crop species to increase crop yields with less water supply. Growing up in China, Yun witnessed environmental issues springing from the development of the steel industry, which caused contamination of rivers in her hometown. On one visit to her aunt’s house in rural China, she learned that water pollution was widespread after noticing wastewater was piped outside of the house into nearby farmland without being treated. These experiences led Yun to study water supply and sewage engineering for her undergraduate degree at Shenyang Jianzhu University. She then went on to complete a master’s program in civil and environmental engineering at Carnegie Mellon University. It was there that Yun discovered a passion for plant-environment interactions; during an independent study on perfluorooctanoic sulfonate, she realized the amazing ability of plants to adapt to environmental changes, toxins, and stresses. Her goal is to continue researching plant and environment interactions and to translate the latest scientific findings into applications that can improve food security. More

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      in Environment

      Greening roofs to boost climate resilience

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      When the historic cities of Europe were built hundreds of years ago, there were open green spaces all around them. But today’s city centers can be a 30-minute drive or more to the vast open greenery that earlier Europeans took for granted.

      That’s what the startup Roofscapes is trying to change. The company, founded by three students from MIT’s master of architecture program, is using timber structures to turn the ubiquitous pitched roofs of Paris into accessible green spaces.

      The spaces would provide a way to grow local food, anchor biodiversity, reduce the temperatures of buildings, improve air quality, increase water retention, and give residents a new way to escape the dense urban clusters of modern times.

      “We see this as a way to unlock the possibilities of these buildings,” says Eytan Levi MA ’21, SM ’21, who co-founded the company with Olivier Faber MA ’23 and Tim Cousin MA ’23. “These surfaces weren’t being used otherwise but could actually have a highly positive contribution to the value of the buildings, the environment, and the lives of the people.”

      For the co-founders, Roofscapes is about helping build up climate resilience for the future while improving quality of life in cities now.

      “It was always important to us to work with as little contradictions to our values as possible in terms of environmental and social impact,” Faber says. “For us, Roofscapes is a way to apply some of our academic learnings to the real world in a way that is tactical and impactful, because we’re tapping into this whole issue — pitched roof adaptation — that has been ignored by traditional architecture.”

      Three architects with a vision

      The founders, who grew up in France, met while studying architecture as undergraduates in Switzerland, but after graduating and working at design firms for a few years, they began discussing other ways they could make a difference.

      “We knew we wanted to have an impact on the built environment that was different than what a lot of architectural firms were doing. We were thinking about a startup, but mostly we came to MIT because we knew we’d have a lot of agency to grow our skills and competency in adapting the built environment to the climate and biodiversity crises,” Faber explains.

      Three months after coming to MIT, they applied to the DesignX accelerator to explore ways to make cities greener by using timber structures to build flat, green platforms on the ubiquitous pitched roofs of European cities’ older buildings.

      “In European city centers, two thirds of the roofs are pitched, and there’s no solution to make them accessible and put green surfaces on them,” Cousin says. “Meanwhile, we have all these issues with heat islands and excessive heat in urban centers, among other issues like biodiversity collapse, retention of rain water, lack of green spaces. Green roofs are one of the best ways to address all of these problems.”

      They began making small models of their imagined green roofs and talking with structural engineers around campus. The founders also gained operational knowledge from MIT’s Center for Real Estate, where Levi studied.

      In 2021, they showcased a 170-square-foot model at the Seoul Biennale of Architecture and Urbanism in South Korea. The model showed roofs made from different materials and pitched at different angles, along with versions of Roofscapes’ wooden platforms with gardens and vegetation built on top.

      When Levi graduated, he moved to Paris, where Cousin and Faber are joining him this spring. “We’re starting with Paris because all the roofs there are the same height, and you can really feel the potential when you go up there to help the city adapt,” says Cousin.

      Roofscapes’ big break came last year, when the company won a grant from the City of Paris as part of a program to improve the city’s climate resilience. The grant will go toward Roofscapes’ first project on the roof of a former town hall building in the heart of Paris. The company plans to test the project’s impact on the temperature of the buildings, humidity levels, and the biodiversity it can foster.

      “We were just three architects with a vision, and at MIT it became a company, and now in Paris we’re seeing the reality of deploying this vision,” Cousin says. “This is not something you do with three people. You need everyone in the city on the same side. We’re being advocates, and it’s exciting to be in this position.”

      A grassroots roof movement

      The founders say they hear at least once a week from a building owner or tenant who is excited to become a partner, giving them a list of more than 60 buildings to consider for their systems down the line. Still, they plan to focus on running tests on a few pilot projects in Paris before expanding more quickly using prefabricated structures.

      “It’s great to hear that constant interest,” Levi says. “It’s like we’re on the same team, because they’re potential clients, but they’re also cheering us on in our work. We know from the interest that once we have a streamlined process, we can get a lot of projects at once.”

      Even in just the three years since founding the company, the founders say they’ve seen their work take on a new sense of urgency.

      “We’ve seen a shift in people’s minds since we started three years ago,” Levi says. “Global warming is becoming increasingly graspable, and we’re seeing a greater will from building owners and inhabitants. People are very supportive of the notion that we have a heritage environment, but as the climate changes drastically, our building stock doesn’t work anymore the way it worked in the 19th century. It needs to be adapted, and that’s what we are doing.” More