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      in Energy

      Working to make nuclear energy more competitive

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      Assil Halimi has loved science since he was a child, but it was a singular experience at a college internship that stoked his interest in nuclear engineering. As part of work on a conceptual design for an aircraft electric propulsion system, Halimi had to read a chart that compared the energy density of various fuel sources. He was floored to see that the value for uranium was orders of magnitude higher than the rest. “Just a fuel pellet the size of my fingertip can generate as much energy as a ton of coal or 150 gallons of oil,” Halimi points out.

      Having grown up in Algeria, in an economy dominated by oil and gas, Halimi was always aware of energy’s role in fueling growth. But here was a source that showed enormous potential. “The more I read about nuclear, the more I saw its direct relationship with climate change and how nuclear energy can potentially replace the carbonized economy,” Halimi says. “The problem we’re dealing with right now is that the source of energy is not clean. Nuclear [presented itself] as an answer, or at least as a promise that you can dig into,” he says. “I was also seeing the electrification of systems and the economy evolving.”

      A tectonic shift was brewing, and Halimi wanted in.

      Then an electrical engineering major at the Institut National des Sciences Appliquées de Lyon (INSA Lyon), Halimi added nuclear engineering as a second major. Today, the second-year doctoral student at MIT’s Department of Nuclear Science and Engineering (NSE) has expanded on his early curiosity in the field and researches methods of improving the design of small modular reactors. Under Professor Koroush Shirvan’s advisement, Halimi also studies high burnup fuel so we can extract more energy from the same amount of material.

      A foot in two worlds

      The son of a computer engineer father and a mother who works as a judge, Halimi was born in Algiers and grew up in Cherchell, a small town near the capital. His interest in science grew sharper in middle school; Halimi remembers being a member of the astronomy club. As a middle and high schooler, Halimi traveled to areas with low light pollution to observe the night skies.

      As a teenager, Halimi set his goals high, enrolling in high school in both Algeria and France. Taking classes in Arabic and French, he found a fair amount of overlap between the two curricula. The divergence in the nonscientific classes gave Halimi a better understanding of the cultural perspectives. After studying the French curriculum remotely, Halimi graduated with two diplomas. He remembers having to take two baccalaureate exams, which didn’t bother him much, but he did have to miss viewing parts of the 2014 World Cup soccer tournament.

      A multidisciplinary approach to engineering

      After high school, Halimi moved to France to study engineering at INSA Lyon. He elected for a major in electrical engineering and, ever the pragmatist, also signed up for a bachelor’s degree in math and economics. “You can build a lot of amazing things, but you have to take costs into account to make sure you’re proposing something feasible that can make it in the real world,” Halimi says, explaining his motivation to study economics.

      Wrapping up his bachelor’s in math and economics in two short years, Halimi decided to pursue a double curriculum in electrical and nuclear engineering during his final year of engineering studies. Since his school in Lyon did not offer the double curriculum, Halimi had to move to Paris to study at The French Alternative Energies and Atomic Energy Commission (CEA), part of the University of Paris-Saclay. The summer before he started, he traveled to Japan and toured the Fukushima nuclear power plant.

      Halimi first conducted research at MIT NSE as part of an internship in nuclear engineering when he was still a student in France. He remembers wanting to explore work on reactor design, when an advisor at CEA recommended interning with Shirvan.

      Pragmatism in nuclear energy adoption

      Halimi’s work at MIT NSE focuses on high burnup fuel assessment and small modular reactor (SMR) design.

      Existing nuclear plants have faced stiff competition during the last decade. Improving the fuel efficiency (high burnup) is a potential way of improving the economic competitiveness of the existing reactor fleet. One challenge is that materials degrade when you keep them longer in the reactor. Halimi evaluates fuel performance and safety features of more efficient fuel operation using advanced computer simulation tools. At the 2022 TopFuel Light Water Reactor Fuel Performance Conference, Halimi presented a paper describing strategies to achieve higher burnups. He is now working on journal paper about this work.

      Halimi’s research on SMR design is motivated by the industry’s move to smaller plants that take less time to construct. The challenge, he says, is that if you simply make the reactors smaller, you lose the advantages of economies of scale and might end up with a more expensive economic proposal. Halimi’s goal is to analyze how smaller reactors can compensate for economies of scale by improving their technical design. Other advantages stacked in favor of smaller reactors is that they can be constructed faster and in series.

      Halimi analyzes the fuel performance, core design, thermal hydraulics, and safety of these small reactors. “One efficient way that I particularly assess to improve their economics is high power density operation,” he says. In late 2021 Halimi published a paper on the relationship between cost and reactor power density in Nuclear Engineering and Design Journal. The research has been featured in other conference papers.

      When he’s not working, Halimi makes time to play soccer and hopes to get back into astronomy. “I sold all my gear when I moved from Europe so I need to buy new ones at some point,” he says.

      Halimi is convinced that nuclear power will be a serious contender in the energy landscape. “You have to propose something that will make everyone happy,” Halimi laughs when he describes work in nuclear science and engineering.

      The work ahead is daunting — “Nuclear power is safe, sustainable, and reliable; now we need to be on time and on budget [to achieve] climate goals” he says — but Halimi is ready. By addressing both the competitiveness of the existing reactors through high burnup fuels and designing the next generation of nuclear plants, he is adopting a dual-pronged approach to make nuclear energy an economical and viable alternative to carbon-based fuels. More

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      in Environment

      Nanotube sensors are capable of detecting and distinguishing gibberellin plant hormones

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      Researchers from the Disruptive and Sustainable Technologies for Agricultural Precision (DiSTAP) interdisciplinary research group of the Singapore-MIT Alliance for Research and Technology (SMART), MIT’s research enterprise in Singapore, and their collaborators from Temasek Life Sciences Laboratory have developed the first-ever nanosensor that can detect and distinguish gibberellins (GAs), a class of hormones in plants that are important for growth. The novel nanosensors are nondestructive, unlike conventional collection methods, and have been successfully tested in living plants. Applied in the field for early-stage plant stress monitoring, the sensors could prove transformative for agriculture and plant biotechnology, giving farmers interested in high-tech precision agriculture and crop management a valuable tool to optimize yield.

      The researchers designed near-infrared fluorescent carbon nanotube sensors that are capable of detecting and distinguishing two plant hormones, GA3 and GA4. Belonging to a class of plant hormones known as gibberellins, GA3 and GA4 are diterpenoid phytohormones produced by plants that play an important role in modulating diverse processes involved in plant growth and development. GAs are thought to have played a role in the driving forces behind the “green revolution” of the 1960s, which was in turn credited with averting famine and saving the lives of many worldwide. The continued study of gibberellins could lead to further breakthroughs in agricultural science and have implications for food security.

      Climate change, global warming, and rising sea levels cause farming soil to get contaminated by saltwater, raising soil salinity. In turn, high soil salinity is known to negatively regulate GA biosynthesis and promote GA metabolism, resulting in the reduction of GA content in plants. The new nanosensors developed by the SMART researchers allow for the study of GA dynamics in living plants under salinity stress at a very early stage, potentially enabling farmers to make early interventions when eventually applied in the field. This forms the basis of early-stage stress detection.

      Currently, methods to detect GA3 and GA4 typically require mass spectroscopy-based analysis, a time-consuming and destructive process. In contrast, the new sensors developed by the researchers are highly selective for the respective GAs and offer real-time, in vivo monitoring of changes in GA levels across a broad range of plant species.

      Described in a paper titled “Near-Infrared Fluorescent Carbon Nanotube Sensors for the Plant Hormone Family Gibberellins” published in the journal Nano Letters, the research represents a breakthrough for early-stage plant stress detection and holds tremendous potential to advance plant biotechnology and agriculture. This paper builds on previous research by the team at SMART DiSTAP on single-walled carbon nanotube-based nanosensors using the corona phase molecular recognition (CoPhMoRe) platform.

      Based on the CoPhMoRe concept introduced by the lab of MIT Professor Professor Michael Strano, the novel sensors are able to detect GA kinetics in the roots of a variety of model and non-model plant species, including Arabidopsis, lettuce, and basil, as well as GA accumulation during lateral root emergence, highlighting the importance of GA in root system architecture. This was made possible by the researchers’ related development of a new coupled Raman/near infrared fluorimeter that enables self-referencing of nanosensor near infrared fluorescence with its Raman G-band, a new hardware innovation that removes the need for a separate reference nanosensor and greatly simplifies the instrumentation requirements by using a single optical channel to measure hormone concentration.

      Using the reversible GA nanosensors, the researchers detected increased endogenous GA levels in mutant plants producing greater amounts of GA20ox1, a key enzyme in GA biosynthesis, as well as decreased GA levels in plants under salinity stress. When exposed to salinity stress, researchers also found that lettuce growth was severely stunted — an indication that only became apparent after 10 days. In contrast, the GA nanosensors reported decreased GA levels after just six hours, demonstrating their efficacy as a much earlier indicator of salinity stress.

      “Our CoPhMoRe technique allows us to create nanoparticles that act like natural antibodies in that they can recognize and lock onto specific molecules. But they tend to be far more stable than alternatives. We have used this method to successfully create nanosensors for plant signals such as hydrogen peroxide and heavy-metal pollutants like arsenic in plants and soil,” says Strano, the Carbon P. Dubbs Professor of Chemical Engineering at MIT who is co-corresponding author and DiSTAP co-lead principal investigator. “The method works to create sensors for organic molecules like synthetic auxin — an important plant hormone — as we have shown. This latest breakthrough now extends this success to a plant hormone family called gibberellins — an exceedingly difficult one to recognize.”

      Strano adds: “The resulting technology offers a rapid, real-time, and in vivo method to monitor changes in GA levels in virtually any plant, and can replace current sensing methods which are laborious, destructive, species-specific, and much less efficient.”

      Mervin Chun-Yi Ang, associate scientific director at DiSTAP and co-first author of the paper, says, “More than simply a breakthrough in plant stress detection, we have also demonstrated a hardware innovation in the form of a new coupled Raman/NIR fluorimeter that enabled self-referencing of SWNT sensor fluorescence with its Raman G-band, representing a major advance in the translation of our nanosensing tool sets to the field. In the near future, our sensors can be combined with low-cost electronics, portable optodes, or microneedle interfaces for industrial use, transforming how the industry screens for and mitigates plant stress in food crops and potentially improving growth and yield.”

      The new sensors could yet have a variety of industrial applications and use cases. Daisuke Urano, a Temasek Life Sciences Laboratory principal investigator, National University of Singapore (NUS) adjunct assistant professor, and co-corresponding author of the paper, explains, “GAs are known to regulate a wide range of plant development processes, from shoot, root, and flower development, to seed germination and plant stress responses. With the commercialization of GAs, these plant hormones are also sold to growers and farmers as plant growth regulators to promote plant growth and seed germination. Our novel GA nanosensors could be applied in the field for early-stage plant stress monitoring, and also be used by growers and farmers to track the uptake or metabolism of GA in their crops.”

      The design and development of the nanosensors, creation and validation of the coupled Raman/near infrared fluorimeter and related image/data processing algorithms, as well as statistical analysis of readouts from plant sensors for this study were performed by SMART and MIT. The Temasek Life Sciences Laboratory was responsible for the design, execution, and analysis of plant-related studies, including validation of nanosensors in living plants.

      This research was carried out by SMART and supported by the National Research Foundation of Singapore under its Campus for Research Excellence And Technological Enterprise (CREATE) program. The DiSTAP program, led by Strano and Singapore co-lead principal investigator Professor Chua Nam Hai, addresses deep problems in food production in Singapore and the world by developing a suite of impactful and novel analytical, genetic, and biomaterial technologies. The goal is to fundamentally change how plant biosynthetic pathways are discovered, monitored, engineered, and ultimately translated to meet the global demand for food and nutrients. Scientists from MIT, Temasek Life Sciences Laboratory, Nanyang Technological University (NTU) and NUS are collaboratively developing new tools for the continuous measurement of important plant metabolites and hormones for novel discovery, deeper understanding and control of plant biosynthetic pathways in ways not yet possible, especially in the context of green leafy vegetables; leveraging these new techniques to engineer plants with highly desirable properties for global food security, including high yield density production, and drought and pathogen resistance, and applying these technologies to improve urban farming.

      SMART was established by MIT and the National Research Foundation of Singapore in 2007. SMART serves as an intellectual and innovation hub for research interactions between MIT and Singapore, undertaking cutting-edge research projects in areas of interest to both Singapore and MIT. SMART currently comprises an Innovation Center and five interdisciplinary research groups: Antimicrobial Resistance, Critical Analytics for Manufacturing Personalized-Medicine, DiSTAP, Future Urban Mobility, and Low Energy Electronic Systems. More

    • 163 Shares109 Views

      in Energy

      3 Questions: Antje Danielson on energy education and its role in climate action

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      The MIT Energy Initiative (MITEI) leads energy education at MIT, developing and implementing a robust educational toolkit for MIT graduate and undergraduate students, online learners around the world, and high school students who want to contribute to the energy transition. As MITEI’s director of education, Antje Danielson manages a team devoted to training the next generation of energy innovators, entrepreneurs, and policymakers. Here, she discusses new initiatives in MITEI’s education program and how they are preparing students to take an active role in climate action.

      Q: What role are MITEI’s education efforts playing in climate action initiatives at MIT, and what more could we be doing?

      A: This is a big question. The carbon emissions from energy are such an important factor in climate mitigation; therefore, what we do in energy education is practically synonymous with climate education. This is well illustrated in a 2018 Nature Energy paper by Fuso Nerini, which outlines that affordable, clean energy is related to many of the United Nations Sustainable Development Goals (SDGs) — not just SDG 7, which specifically calls for “affordable, reliable, sustainable, and modern energy for all” by 2030. There are 17 SDGs containing 169 targets, of which 113 (65 percent) require actions to be taken concerning energy systems.

      Now, can we equate education with action? The answer is yes, but only if it is done correctly. From the behavioral change literature, we know that knowledge alone is not enough to change behavior. So, one important part of our education program is practice and experience through research, internships, stakeholder engagement, and other avenues. At a minimum, education must give the learner the knowledge, skills, and courage to be ready to jump into action, but ideally, practice is a part of the offering. We also want our learners to go out into the world and share what they know and do. If done right, education is an energy transition accelerator.

      At MITEI, our learners are not just MIT students. We are creating online offerings based on residential MIT courses to train global professionals, policymakers, and students in research methods and tools to support and accelerate the energy transition. These are free and open to learners worldwide. We have five courses available now, with more to come.

      Our latest program is a collaboration with MIT’s Center for Energy and Environmental Policy Research (CEEPR): Climate Action through Education, or CATE. This is a teach-the-teacher program for high school curriculum and is a part of the MIT Climate Action Plan. The aim is to develop interdisciplinary, solutions-focused climate change curricula for U.S. high school teachers with components in history/social science, English/language arts, math, science, and computer science.

      We are rapidly expanding our programming. In the online space, for our global learners, we are bundling courses for professional development certificates; for our undergraduates, we are redesigning the energy studies minor to reflect what we have learned over the past 12 years; and for our graduate students, we are adding a new program that allows them to garner industry experience related to the energy transition. Meanwhile, CATE is creating a support network for the teachers who adopt the curriculum. We are also working on creating an energy and climate alliance with other universities around the world.

      On the Institute level, I am a member of the Climate Education Working Group, a subgroup of the Climate Nucleus, where we discuss and will soon recommend further climate action the Institute can take. Stay tuned for that.

      Q: You mentioned that you are leading an effort to create a consortium of energy and climate education programs at universities around the world. How does this effort fit into MITEI’s educational mission?

      A: Yes, we are currently calling it the “Energy and Climate Education Alliance.” The background to this is that the problem we are facing — transitioning the entire global energy system from high carbon emissions to low, no, and negative carbon emissions — is global, huge, and urgent. Following the proverbial “many hands make light work,” we believe that the success of this very complex task is accomplished quicker with more participants. There is, of course, more to this as well. The complexity of the problem is such that (1) MIT doesn’t have all the expertise needed to accomplish the educational needs of the climate and energy crisis, (2) there is a definite local and regional component to capacity building, and (3) collaborations with universities around the world will make our mission-driven work more efficient. Finally, these collaborations will be advantageous for our students as they will be able to learn from real-world case studies that are not U.S.-based and maybe even visit other universities abroad, do internships, and engage in collaborative research projects. Also, students from those universities will be able to come here and experience MIT’s unique intellectual environment.

      Right now, we are very much in the beginning stages of creating the alliance. We have signed a collaboration agreement with the Technical University of Berlin, Germany, and are engaged in talks with other European and Southeast Asian universities. Some of the collaborations we are envisioning relate to course development, student exchange, collaborative research, and course promotion. We are very excited about this collaboration. It fits well into MIT’s ambition to take climate action outside of the university, while still staying within our educational mission.

      Q: It is clear to me from this conversation that MITEI’s education program is undertaking a number of initiatives to prepare MIT students and interested learners outside of the Institute to take an active role in climate action. But, the reality is that despite our rapidly changing climate and the immediate need to decarbonize our global economy, climate denialism and a lack of climate and energy understanding persist in the greater global population. What do you think must be done, and what can MITEI do, to increase climate and energy literacy broadly?

      A: I think the basic problem is not necessarily a lack of understanding but an abundance of competing issues that people are dealing with every day. Poverty, personal health, unemployment, inflation, pandemics, housing, wars — all are very immediate problems people have. And climate change is perceived to be in the future.

      The United States is a very bottom-up country, where corporations offer what people buy, and politicians advocate for what voters want and what money buys. Of course, this is overly simplified, but as long as we don’t come up with mechanisms to achieve a monumental shift in consumer and voter behavior, we are up against these immediate pressures. However, we are seeing some movement in this area due to rising gas and heating oil prices and the many natural disasters we are encountering now. People are starting to understand that climate change will hit their pocketbook, whether or not we have a carbon tax. The recent Florida hurricane damage, wildfires in the west, extreme summer temperatures, frequent droughts, increasing numbers of poisonous and disease-carrying insects — they all illustrate the relationship between climate change, health, and financial damage. Fewer and fewer people will be able to deny the existence of climate change because they will either be directly affected or know someone who is.

      The question is one of speed and scale. The more we can help to make the connections even more visible and understood, the faster we get to the general acceptance that this is real. Research projects like CEEPR’s Roosevelt Project, which develops action plans to help communities deal with industrial upheaval in the context of the energy transition, are contributing to this effect, as are studies related to climate change and national security. This is a fast-moving world, and our research findings need to be translated as we speak. A real problem in education is that we have the tendency to teach the tried and true. Our education programs have to become much nimbler, which means curricula have to be updated frequently, and that is expensive. And of course, the speed and magnitude of our efforts are dependent on the funding we can attract, and fundraising for education is more difficult than fundraising for research.

      However, let me pivot: You alluded to the fact that this is a global problem. The immediate pressures of poverty and hunger are a matter of survival in many parts of the world, and when it comes to surviving another day, who cares if climate change will render your fields unproductive in 20 years? Or if the weather turns your homeland into a lake, will you think about lobbying your government to reduce carbon emissions, or will you ask for help to rebuild your existence? On the flip side, politicians and government authorities in those areas have to deal with extremely complex situations, balancing local needs with global demands. We should learn from them. What we need is to listen. What do these areas of the world need most, and how can climate action be included in the calculations? The Global Commission to End Energy Poverty, a collaboration between MITEI and the Rockefeller Foundation to bring electricity to the billion people across the globe who currently live without it, is a good example of what we are already doing. Both our online education program and the Energy and Climate Education Alliance aim to go in this direction.

      The struggle and challenge to solve climate change can be pretty depressing, and there are many days when I feel despondent about the speed and progress we are making in saving the future of humanity. But, the prospect of contributing to such a large mission, even if the education team can only nudge us a tiny bit away from the business-as-usual scenario, is exciting. In particular, working on an issue like this at MIT is amazing. So much is happening here, and there don’t seem to be intellectual limits; in fact, thinking big is encouraged. It is very refreshing when one has encountered the old “you can’t do this” too often in the past. I want our students to take this attitude with them and go out there and think big. More

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      in Environment

      Creating the steps to make organizational sustainability work

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      Sustainability is a hot topic. Companies throw around their carbon or recycling initiatives, and competing executives feel the need to follow suit. But aside from the external pressure, there are also bottom-line benefits. Becoming more efficient can save money. Creating a new product might make money; customers care about a company’s practices and will spend their money based on that.

      The work is in getting there, because becoming sustainable can seem simple: Establish a goal for five years down the road, and everything will fall into place — but it’s easy for things to get upended. “There is so much confusion and noise in this space,” says Jason Jay, senior lecturer and director of the Sustainability Initiative at MIT’s Sloan School of Management.

      His work is to help companies break through the confusion and figure out what they want to actually do, not merely what sounds good. It means doing research and listening to science. Mostly, it requires discipline, and because something new — be it a product, process or technology — is being asked for, it also takes ambition. “It’s a tricky dance,” he says, but one that can result in “doing well and doing good at the same time.”

      Play video

      It’s about taking steps

      Three steps, to be exact. The first, which is the crux, Jay says, is for a company to focus on a small set of issues that it can take the lead on. It sounds obvious, but it’s often missed. The problem is that companies will do either one of two things. They’ll take an outside-in approach in which they end up listening to too many stakeholders, “get pulled in a million different directions,” and try to solve all of society’s problems, which means solving none of them, he says.

      Or they’ll go inside-out and have one executive in charge of sustainability who will do some internal research and come up with an initiative. It might be a good idea, but it doesn’t take into account how it will affect the facilities, supply chains, and the people who work with them. And without that consideration, “It’s going to be very difficult to get the necessary traction inside the company,” Jay says.

      What’s needed is a combination of the two — outside perspectives coupled with insider knowledge — in order to find an initiative that resonates for that company. It starts with looking at what the company already does. That might show where it’s making a negative impact and, in turn, where it could make a positive one. It also involves the C-suite executives asking themselves, “What do we want this company to stand for?” and then, “What do I want my legacy to be?”

      Still, it can be hard to envision what change can look like or what actions might have an impact. Jay says this is where a simulation tool like En-ROADS, developed by MIT Sloan and Climate Interactive, can help explore scenarios.

      But it’s ultimately about making a commitment and allowing an iterative process to play out. A company then discovers its true focus might be something less flashy. Nike early on, for example, found that a huge source of greenhouse gas emissions was sulfur hexafluoride gas in the Nike Air bladder. When they re-engineered it, they ended up with inert nitrogen and a stronger material that was aesthetically cool and lightweight for the athlete. That didn’t come in one brainstorming meeting. It meant doing research and looking at what the science says is possible. It’s not quick, but it also shouldn’t be, if the goal is to take real, measurable action.

      “Cheap talk leads to cheap things,” Jay says. 

      Play video

      The next two

      Deciding what matters is key, but nothing materializes without establishing concrete goals. This is where a company “shows the world you’re serious.” But it’s a place where companies slip up. They either set weak goals, ones they know they can easily reach, so there’s no challenge, no accomplishment, “no stretch,” Jay says. Or they set goals that are too ambitious and/or aren’t backed by science. It could be, “We’re going to be net zero by 2050,” but how exactly is never answered.

      Jay says it’s about finding the sweet spot of having a reasonable amount of goals — like two to four — and then have those goals feel like a reach, yet possible. When that balance is right, it becomes a self-fulfilling prophecy. People stay motivated because they experience progress. But if it’s off, it won’t happen.

      “You need that optimal creative tension,” he says.

      And then there’s the third step. Companies need to find partners to make their sustainability programs succeed. It’s the one part that’s most overlooked because executives continually believe that they can do it alone. But they can’t, because big initiatives require help and expertise outside of a company’s realm.

      Maersk, the global shipping company, has a goal of replacing fossil fuel with green fuels for ocean freight, Jay says. It discovered that green ammonia could make that happen, and it was Yara, a fertilizer company, which best understood ammonia production. But it could also be a startup that’s working on a promising technology. Sometimes, as with moving to electric cars, what’s needed are political partners to enact policy and offer tax breaks and incentives. And it might be that the answer is collaborating with activists who have been pushing a company to change its ways.

      “There are strange bedfellows all around,” Jay says.

      Know how to tap the brake

      All the steps circle back to the essential point that becoming sustainable takes a committed investment of time, money, and patience. Starting small helps, especially in a corporate culture that tends to move slowly. Jay says there’s nothing wrong with going from zero projects to one, even if it’s a small one in a specific department. It allows people to become accustomed to the idea of change. It also lets the company establish a framework, analyze results, and build momentum, making it easier to ramp up.

      The patience part can be hard since there’s a rightful sense of urgency involved. Companies want to show that they’re doing something, and want to affect climate change sooner rather than later. But Jay likens it to building a skyscraper. The desire is to get it up fast, but if the foundation is shaky, everything will crumble.

      “What we’re trying to do is strengthen that foundation so it can reach the height we need,” he says. More

    • 88 Shares159 Views

      in Environment

      Aviva Intveld named 2023 Gates Cambridge Scholar

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      MIT senior Aviva Intveld has won the prestigious Gates Cambridge Scholarship, which offers students an opportunity to pursue graduate study in the field of their choice at Cambridge University in the U.K. Intveld will join the other 23 U.S. citizens selected for the 2023 class of scholars.

      Intveld, from Los Angeles, is majoring in earth, atmospheric, and planetary sciences, and minoring in materials science and engineering with concentrations in geology, geochemistry, and archaeology. Her research interests span the intersections among those fields to better understand how the natural environments of the past have shaped human movement and decision-making.

      At Cambridge, Intveld will undertake a research MPhil in earth sciences at the Godwin Lab for Paleoclimate Research, where she will investigate the impact of past climate on the ancient Maya in northwest Yucatán via cave sediment records. She hopes to pursue an impact-oriented research career in paleoclimate and paleoenvironment reconstruction and ultimately apply the lessons learned from her research to inform modern climate policy. She is particularly passionate about sustainable mining of energy-critical elements and addressing climate change inequality in her home state of California.

      Intveld’s work at Cambridge will build upon her extensive research experience at MIT. She currently works in the McGee Lab reconstructing the Late Pleistocene-Early Holocene paleoclimate of northeastern Mexico to provide a climatic background to the first peopling of the Americas. Previously, she explored the influence of mountain plate tectonics on biodiversity in the Perron Lab. During a summer research position at the University of Haifa in Israel she analyzed the microfossil assemblage of an offshore sediment core for paleo-coastal reconstruction.

      Last summer, Intveld interned at the National Oceanic and Atmospheric Administration in Homer, Alaska, to identify geologic controls on regional groundwater chemistry. She has also interned with the World Wildlife Fund and with the Natural History Museum of Los Angeles. During her the spring semester of her junior year, Intveld studied abroad through MISTI at Imperial College London’s Royal School of Mines and completed geology field work in Sardinia, Italy.

      Intveld has been a strong presence on MIT’s campus, serving as the undergraduate representative on the EAPS Diversity, Equity, and Inclusion Committee. She leads tours for the MIT List Visual Arts Center, is a member of and associate advisor for the Terrascope Learning Community, and is a participant in the Addir Interfaith Dialogue Fellowship.

      Inveld was advised in her application by Kim Benard, associate dean of the Distinguished Fellowships team in Career Advising and Professional Development, who says, “Aviva’s work is at a fascinating crossroads of archeology, geology, and sustainability. She has already done extraordinary work, and this opportunity will prepare her even more to be influential in the fight for climate mitigation.”

      Established by the Bill and Melinda Gates Foundation in 2000, the Gates Cambridge Scholarship provides full funding for talented students from outside the United Kingdom to pursue postgraduate study in any subject at Cambridge University. Since the program’s inception in 2001, there have been 33 Gates Cambridge Scholars from MIT. More

    • 88 Shares149 Views

      in Energy

      Integrating humans with AI in structural design

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      Modern fabrication tools such as 3D printers can make structural materials in shapes that would have been difficult or impossible using conventional tools. Meanwhile, new generative design systems can take great advantage of this flexibility to create innovative designs for parts of a new building, car, or virtually any other device.

      But such “black box” automated systems often fall short of producing designs that are fully optimized for their purpose, such as providing the greatest strength in proportion to weight or minimizing the amount of material needed to support a given load. Fully manual design, on the other hand, is time-consuming and labor-intensive.

      Now, researchers at MIT have found a way to achieve some of the best of both of these approaches. They used an automated design system but stopped the process periodically to allow human engineers to evaluate the work in progress and make tweaks or adjustments before letting the computer resume its design process. Introducing a few of these iterations produced results that performed better than those designed by the automated system alone, and the process was completed more quickly compared to the fully manual approach.

      The results are reported this week in the journal Structural and Multidisciplinary Optimization, in a paper by MIT doctoral student Dat Ha and assistant professor of civil and environmental engineering Josephine Carstensen.

      The basic approach can be applied to a broad range of scales and applications, Carstensen explains, for the design of everything from biomedical devices to nanoscale materials to structural support members of a skyscraper. Already, automated design systems have found many applications. “If we can make things in a better way, if we can make whatever we want, why not make it better?” she asks.

      “It’s a way to take advantage of how we can make things in much more complex ways than we could in the past,” says Ha, adding that automated design systems have already begun to be widely used over the last decade in automotive and aerospace industries, where reducing weight while maintaining structural strength is a key need.

      “You can take a lot of weight out of components, and in these two industries, everything is driven by weight,” he says. In some cases, such as internal components that aren’t visible, appearance is irrelevant, but for other structures aesthetics may be important as well. The new system makes it possible to optimize designs for visual as well as mechanical properties, and in such decisions the human touch is essential.

      As a demonstration of their process in action, the researchers designed a number of structural load-bearing beams, such as might be used in a building or a bridge. In their iterations, they saw that the design has an area that could fail prematurely, so they selected that feature and required the program to address it. The computer system then revised the design accordingly, removing the highlighted strut and strengthening some other struts to compensate, and leading to an improved final design.

      The process, which they call Human-Informed Topology Optimization, begins by setting out the needed specifications — for example, a beam needs to be this length, supported on two points at its ends, and must support this much of a load. “As we’re seeing the structure evolve on the computer screen in response to initial specification,” Carstensen says, “we interrupt the design and ask the user to judge it. The user can select, say, ‘I’m not a fan of this region, I’d like you to beef up or beef down this feature size requirement.’ And then the algorithm takes into account the user input.”

      While the result is not as ideal as what might be produced by a fully rigorous yet significantly slower design algorithm that considers the underlying physics, she says it can be much better than a result generated by a rapid automated design system alone. “You don’t get something that’s quite as good, but that was not necessarily the goal. What we can show is that instead of using several hours to get something, we can use 10 minutes and get something much better than where we started off.”

      The system can be used to optimize a design based on any desired properties, not just strength and weight. For example, it can be used to minimize fracture or buckling, or to reduce stresses in the material by softening corners.

      Carstensen says, “We’re not looking to replace the seven-hour solution. If you have all the time and all the resources in the world, obviously you can run these and it’s going to give you the best solution.” But for many situations, such as designing replacement parts for equipment in a war zone or a disaster-relief area with limited computational power available, “then this kind of solution that catered directly to your needs would prevail.”

      Similarly, for smaller companies manufacturing equipment in essentially “mom and pop” businesses, such a simplified system might be just the ticket. The new system they developed is not only simple and efficient to run on smaller computers, but it also requires far less training to produce useful results, Carstensen says. A basic two-dimensional version of the software, suitable for designing basic beams and structural parts, is freely available now online, she says, as the team continues to develop a full 3D version.

      “The potential applications of Prof Carstensen’s research and tools are quite extraordinary,” says Christian Málaga-Chuquitaype, a professor of civil and environmental engineering at Imperial College London, who was not associated with this work. “With this work, her group is paving the way toward a truly synergistic human-machine design interaction.”

      “By integrating engineering ‘intuition’ (or engineering ‘judgement’) into a rigorous yet computationally efficient topology optimization process, the human engineer is offered the possibility of guiding the creation of optimal structural configurations in a way that was not available to us before,” he adds. “Her findings have the potential to change the way engineers tackle ‘day-to-day’ design tasks.” More

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      in Environment

      Improving health outcomes by targeting climate and air pollution simultaneously

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      Climate policies are typically designed to reduce greenhouse gas emissions that result from human activities and drive climate change. The largest source of these emissions is the combustion of fossil fuels, which increases atmospheric concentrations of ozone, fine particulate matter (PM2.5) and other air pollutants that pose public health risks. While climate policies may result in lower concentrations of health-damaging air pollutants as a “co-benefit” of reducing greenhouse gas emissions-intensive activities, they are most effective at improving health outcomes when deployed in tandem with geographically targeted air-quality regulations.

      Yet the computer models typically used to assess the likely air quality/health impacts of proposed climate/air-quality policy combinations come with drawbacks for decision-makers. Atmospheric chemistry/climate models can produce high-resolution results, but they are expensive and time-consuming to run. Integrated assessment models can produce results for far less time and money, but produce results at global and regional scales, rendering them insufficiently precise to obtain accurate assessments of air quality/health impacts at the subnational level.

      To overcome these drawbacks, a team of researchers at MIT and the University of California at Davis has developed a climate/air-quality policy assessment tool that is both computationally efficient and location-specific. Described in a new study in the journal ACS Environmental Au, the tool could enable users to obtain rapid estimates of combined policy impacts on air quality/health at more than 1,500 locations around the globe — estimates precise enough to reveal the equity implications of proposed policy combinations within a particular region.

      “The modeling approach described in this study may ultimately allow decision-makers to assess the efficacy of multiple combinations of climate and air-quality policies in reducing the health impacts of air pollution, and to design more effective policies,” says Sebastian Eastham, the study’s lead author and a principal research scientist at the MIT Joint Program on the Science and Policy of Global Change. “It may also be used to determine if a given policy combination would result in equitable health outcomes across a geographical area of interest.”

      To demonstrate the efficiency and accuracy of their policy assessment tool, the researchers showed that outcomes projected by the tool within seconds were consistent with region-specific results from detailed chemistry/climate models that took days or even months to run. While continuing to refine and develop their approaches, they are now working to embed the new tool into integrated assessment models for direct use by policymakers.

      “As decision-makers implement climate policies in the context of other sustainability challenges like air pollution, efficient modeling tools are important for assessment — and new computational techniques allow us to build faster and more accurate tools to provide credible, relevant information to a broader range of users,” says Noelle Selin, a professor at MIT’s Institute for Data, Systems and Society and Department of Earth, Atmospheric and Planetary Sciences, and supervising author of the study. “We are looking forward to further developing such approaches, and to working with stakeholders to ensure that they provide timely, targeted and useful assessments.”

      The study was funded, in part, by the U.S. Environmental Protection Agency and the Biogen Foundation. More

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      in Environment

      Study: Carbon-neutral pavements are possible by 2050, but rapid policy and industry action are needed

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      Almost 2.8 million lane-miles, or about 4.6 million lane-kilometers, of the United States are paved.

      Roads and streets form the backbone of our built environment. They take us to work or school, take goods to their destinations, and much more.

      However, a new study by MIT Concrete Sustainability Hub (CSHub) researchers shows that the annual greenhouse gas (GHG) emissions of all construction materials used in the U.S. pavement network are 11.9 to 13.3 megatons. This is equivalent to the emissions of a gasoline-powered passenger vehicle driving about 30 billion miles in a year.

      As roads are built, repaved, and expanded, new approaches and thoughtful material choices are necessary to dampen their carbon footprint. 

      The CSHub researchers found that, by 2050, mixtures for pavements can be made carbon-neutral if industry and governmental actors help to apply a range of solutions — like carbon capture — to reduce, avoid, and neutralize embodied impacts. (A neutralization solution is any compensation mechanism in the value chain of a product that permanently removes the global warming impact of the processes after avoiding and reducing the emissions.) Furthermore, nearly half of pavement-related greenhouse gas (GHG) savings can be achieved in the short term with a negative or nearly net-zero cost.

      The research team, led by Hessam AzariJafari, MIT CSHub’s deputy director, closed gaps in our understanding of the impacts of pavements decisions by developing a dynamic model quantifying the embodied impact of future pavements materials demand for the U.S. road network. 

      The team first split the U.S. road network into 10-mile (about 16 kilometer) segments, forecasting the condition and performance of each. They then developed a pavement management system model to create benchmarks helping to understand the current level of emissions and the efficacy of different decarbonization strategies. 

      This model considered factors such as annual traffic volume and surface conditions, budget constraints, regional variation in pavement treatment choices, and pavement deterioration. The researchers also used a life-cycle assessment to calculate annual state-level emissions from acquiring pavement construction materials, considering future energy supply and materials procurement.

      The team considered three scenarios for the U.S. pavement network: A business-as-usual scenario in which technology remains static, a projected improvement scenario aligned with stated industry and national goals, and an ambitious improvement scenario that intensifies or accelerates projected strategies to achieve carbon neutrality. 

      If no steps are taken to decarbonize pavement mixtures, the team projected that GHG emissions of construction materials used in the U.S. pavement network would increase by 19.5 percent by 2050. Under the projected scenario, there was an estimated 38 percent embodied impact reduction for concrete and 14 percent embodied impact reduction for asphalt by 2050.

      The keys to making the pavement network carbon neutral by 2050 lie in multiple places. Fully renewable energy sources should be used for pavement materials production, transportation, and other processes. The federal government must contribute to the development of these low-carbon energy sources and carbon capture technologies, as it would be nearly impossible to achieve carbon neutrality for pavements without them. 

      Additionally, increasing pavements’ recycled content and improving their design and production efficiency can lower GHG emissions to an extent. Still, neutralization is needed to achieve carbon neutrality.

      Making the right pavement construction and repair choices would also contribute to the carbon neutrality of the network. For instance, concrete pavements can offer GHG savings across the whole life cycle as they are stiffer and stay smoother for longer, meaning they require less maintenance and have a lesser impact on the fuel efficiency of vehicles. 

      Concrete pavements have other use-phase benefits including a cooling effect through an intrinsically high albedo, meaning they reflect more sunlight than regular pavements. Therefore, they can help combat extreme heat and positively affect the earth’s energy balance through positive radiative forcing, making albedo a potential neutralization mechanism.

      At the same time, a mix of fixes, including using concrete and asphalt in different contexts and proportions, could produce significant GHG savings for the pavement network; decision-makers must consider scenarios on a case-by-case basis to identify optimal solutions. 

      In addition, it may appear as though the GHG emissions of materials used in local roads are dwarfed by the emissions of interstate highway materials. However, the study found that the two road types have a similar impact. In fact, all road types contribute heavily to the total GHG emissions of pavement materials in general. Therefore, stakeholders at the federal, state, and local levels must be involved if our roads are to become carbon neutral. 

      The path to pavement network carbon-neutrality is, therefore, somewhat of a winding road. It demands regionally specific policies and widespread investment to help implement decarbonization solutions, just as renewable energy initiatives have been supported. Providing subsidies and covering the costs of premiums, too, are vital to avoid shifts in the market that would derail environmental savings.

      When planning for these shifts, we must recall that pavements have impacts not just in their production, but across their entire life cycle. As pavements are used, maintained, and eventually decommissioned, they have significant impacts on the surrounding environment.

      If we are to meet climate goals such as the Paris Agreement, which demands that we reach carbon-neutrality by 2050 to avoid the worst impacts of climate change, we — as well as industry and governmental stakeholders — must come together to take a hard look at the roads we use every day and work to reduce their life cycle emissions. 

      The study was published in the International Journal of Life Cycle Assessment. In addition to AzariJafari, the authors include Fengdi Guo of the MIT Department of Civil and Environmental Engineering; Jeremy Gregory, executive director of the MIT Climate and Sustainability Consortium; and Randolph Kirchain, director of the MIT CSHub. More