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  • richardmitnick 9:05 am on September 4, 2021 Permalink | Reply
    Tags: "Building a better chemical factory—out of microbes", , , , Bioprocess engineering, , Chemical engineering, , , , Glucaric acid, Metabolic engineering, Metabolite valve, , MIT Technology Review (US), ,   

    From MIT Technology Review (US) : “Building a better chemical factory—out of microbes” 

    From MIT Technology Review (US)

    August 24, 2021
    Leigh Buchanan

    Credit: Sasha Israel.

    Professor Kristala Jones Prather ’94 has made it practical to turn microbes into efficient producers of desired chemicals. She’s also working to reduce our dependence on petroleum.

    Metabolic engineers have a problem: cells are selfish. The scientists want to use microbes to produce chemical compounds for industrial applications. The microbes prefer to concentrate on their own growth.

    Kristala L. Jones Prather ’94 has devised a tool that satisfies both conflicting objectives. Her metabolite valve acts like a train switch: it senses when a cell culture has reproduced enough to sustain itself and then redirects metabolic flux—the movement of molecules in a pathway—down the track that synthesizes the desired compound. The results: greater yield of the product and sufficient cell growth to keep the culture healthy and productive.

    William E. Bentley, a professor of bioengineering at The University of Maryland (US), has been following Prather’s work for more than two decades. He calls the valves “a new principle in engineering” that he anticipates will be highly valued in the research community. Their ability to eliminate bottlenecks can prove so essential to those attempting to synthesize a particular molecule in useful quantities that “in many cases it might decide whether it is a successful endeavor or not,” says Bentley.

    Prather, The Massachusetts Institute of Technology (US)’s Arthur D. Little Professor of Chemical Engineering, labors in the intersecting fields of synthetic biology and metabolic engineering: a place where science, rather than art, imitates life. The valves play a major role in her larger goal of programming microbes—chiefly E. coli—to produce chemicals that can be used in a wide range of fields, including energy and medicine. She does that by observing what nature can do. Then she hypothesizes what it should be able to do with an assist from strategically inserted DNA.

    “We are increasing the synthetic capacity of biological systems,” says Prather, who made MIT Technology Review’s TR35 list in 2007. “We need to push beyond what biology can naturally do and start getting it to make compounds that it doesn’t normally make.”

    Prather describes her work as creating a new kind of chemical factory inside microbial cells—one that makes ultra-pure compounds efficiently at scale. Coaxing microbes into producing desired compounds is safer and more environmentally friendly than relying on traditional chemical synthesis, which typically involves high temperatures, high pressures, and complicated instrumentation—and, often, toxic by-products. She didn’t originate the idea of turning microbes into chemical factories, but her lab is known for developing tools and fine-tuning processes that make it efficient and practical.

    That’s the approach she has taken with glucaric acid, which has multiple commercial applications, some of them green. Water treatment plants, for example, have long relied on phosphates to prevent corrosion in pipes and to bind with metals like lead and copper so they don’t leach into the water supply. But phosphates also feed algae blooms in lakes and oceans. Glucaric acid does the same work as phosphates without feeding those toxic blooms.

    Producing glucaric acid the usual way—through chemical oxidation of glucose—is expensive, often yields product that isn’t very pure, and creates a lot of hazardous waste. Prather’s microbial factories produce it with high levels of purity and without the toxic by-products, at a reasonable cost. She cofounded the startup Kalion in 2011 to put her microbial-factory approach into practice. (Prather is Kalion’s chief science officer. Her husband, Darcy Prather ’91, is its president.)

    The company, which is lining up large-scale production in Slovakia, has several prospective customers. Although the largest of these are in oil services, “it also turns out, in the wonderful, wacky way chemistry works, that the same compound is used in pharmaceutical manufacturing,” Prather says. It’s required, for example, in production of the ADHD drug Adderall. And it can be used to make textiles stronger, which could lead to more effective recycling of cotton and other natural materials.

    Kalion’s first target is phosphates, because of their immediate commercial applications. But in her wider research, Prather has also drawn a great big bull’s-eye on petroleum. Eager to produce greener alternatives to gasoline and plastics, she and her research group at MIT are using bacteria to synthesize molecules that would normally be derived from petroleum. “Big picture, if we are successful,” Prather says, “what we are doing is moving things one by one off the shelf to say, ‘That no longer is made from petroleum. That now is made from biomass.’”

    From East Texas to MIT

    Born in Cincinnati, Prather grew up in Longview, Texas, against a backdrop of oilfield pumps and derricks. Her father died before she turned two. Her mother worked at Wylie College, a small, historically Black school—and earned a bachelor’s degree there herself in 2004, Prather is quick to add.

    Her high school’s first valedictorian of color, Prather had only vague ideas about academic and professional opportunities outside her state. With college brochures flooding the family’s mailbox in her junior year, she sought advice from a history teacher. “Math was my favorite subject in high school, and I was enjoying chemistry,” says Prather. The teacher told her that math plus chemistry equaled chemical engineering, and that if she wanted to be an engineer she should go to The Massachusetts Institute of Technology (US). “What’s MIT?” asked Prather.

    Others in the community were no better informed. What was then the DeVry Institute of Technology, a for-profit school with a less-than-stellar academic reputation and campuses around the country, was advertising heavily on television. When she told people she was going to MIT, they assumed it was a DeVry branch in Massachusetts. “They were disappointed, because they thought I was going to do great things,” says Prather. “But here I was going to this trade school to be a plumber’s assistant.”

    In June 1990 Prather arrived on campus to participate in Interphase, a program offered through MIT’s Office of Minority Education. Designed to ease the transition for incoming students, Interphase “was a game-changer,” says Prather. The program introduced her to an enduring group of friends and familiarized her with the campus. Most important, it instilled confidence. Coming from a school without AP classes, Prather had worried about starting off behind the curve. When she found she knew the material in her Interphase math class, it came as a relief. “When I was bored, I thought, ‘I belong here,’” she says.

    As an undergraduate Prather was exposed to bioprocess engineering, which uses living cells to induce desired chemical or physical changes in a material. At that time scientists treated the cells from which the process starts as something fixed. Prather became intrigued by the idea that you could engineer not only the process but also the biology of the cell itself. “The way you could copy and cut and paste DNA appealed to the part of me that liked math,” she says.

    After graduating in 1994, Prather got her PhD at The University of California-Berkeley (US), where her advisor was Jay Keasling, a professor of chemical and biomolecular engineering who was at the forefront of the new field of synthetic biology. At Berkeley, Prather sought ways to move DNA in and out of cells to optimize the creation of desirable proteins.

    The practice at that time was to bulk up cells with lots of DNA, which would in turn produce lots of protein, which would generate lots of the desired chemical compound. But there was a problem, which Prather—who lives near a scenic state park—explains with a local analogy. “I can go for a light hike in the Blue Hills Reservation,” she says, “but not if you put a 50-pound pack on my back.” Similarly, an overloaded cell “can sometimes respond by saying, ‘I am too tired.’” Prather’s doctoral thesis explored systems that efficiently produce a lot of a desired chemical using less DNA.

    In her fourth year at Berkeley, Prather received a fellowship from DuPont and traveled to Delaware for her first full-length presentation. Following standard conference practice, she laid out for her audience the three motivations underlying her research. Afterward, one of the company’s scientists politely explained to her why all three were misguided. “He said, ‘What you are doing is interesting and important, but you are motivated by what you think is important in industry,’” says Prather. “‘And we just don’t care about any of that stuff.’”

    Humbled, Prather decided a sojourn in the corporate world would reduce the risk that her academic career would be consigned to real-world irrelevance. She spent the next four years at Merck, in a group developing processes to make things like therapeutic proteins and vaccines. There she learned about the kinds of projects and problems that matter most to practitioners like her DuPont critic.

    Merck employed hordes of chemists to produce large quantities of chemical compounds for use in new drugs. When part of that process seemed better suited to biology than to chemistry, they would hand it off to the department Prather worked in, which used enzymes to perform the next step. “They were typically not very complicated reactions,” says Prather. “A single step converting A to B.”

    Prather was intrigued by the possibility of performing not just individual steps but the entire chemical synthesis within cells, using chains of reactions called metabolic pathways. That work inspired what would become some of her most acclaimed research at MIT, where she joined the faculty in 2004.

    Finding the production switch

    It wasn’t long after returning to MIT that this young woman from the Texas oil patch took aim at fossil fuels and their by-­products. Many of her lab’s projects focus on replacing petroleum as a feedstock. In one—a collaboration with MIT colleagues Brad Olsen ’03, a chemical engineer, and Desiree Plata, PhD ’09, a civil and environmental engineer—Prather is using biomass to create renewable polymers that could lead to a greener kind of plastic. Her lab is figuring out how to induce microbes to convert sugar from plants into monomers that can then be chemically converted into polymers to create plastic. At the end of the plastic’s usable life, it biodegrades and turns back into nutrients. Those nutrients “will give you more plants from which you can extract more sugar that you can turn into new chemicals to go into new plastics,” says Prather. “It’s the circle of life there.”

    These days she is drawing the most attention for her research in optimizing metabolic pathways—research that she and other scientists can then use to maximize the yield of a desired product.

    The challenge is that cells prioritize the use of nutrients, such as glucose, to grow rather than to manufacture these desirable compounds. More growth for the cell means less product for the scientist. “So you run into a competition problem,” says Prather.

    Take glucaric acid, the chemical produced by Prather’s company—and one that Keasling says is extremely important to industry. (“These molecules are not trivial to produce, particularly at the levels that are needed industrially,” he says.) Prather and her lab had been adding three genes—drawn from mice, yeast, and a bacterium—to E. coli, enabling the bacteria to transform a type of simple sugar into glucaric acid. But the bacteria also needed that sugar for a metabolic pathway that breaks down glucose to feed its own growth and reproduction.

    Prather’s team wanted to shut down the pathway nourishing growth and divert the sugar into a pathway producing glucaric acid—but only after the bacterial culture had grown enough to sustain itself as a productive chemical factory. To do so they used quorum sensing, a kind of communication through which bacteria share information about changes in the number of cells in their colony, which allows them to coordinate colony-wide functions such as gene regulation. The team engineered each cell to produce a protein that then creates a molecule called AHL. When quorum sensing detects a certain amount of AHL—the amount produced in the time it takes for the culture to reach a sustainable size—it activates a switch that turns off production of an enzyme that is part of the glucose breakdown process. The glucose shifts to the chemical-synthesis pathway, greatly increasing the amount of glucaric acid produced.

    Prather’s switches, called metabolite valves, are now used in processes that harness microbes to produce a wide range of desired chemicals. The valves open or close in response to changes in the density of particular molecules in a pathway. These switches can be fine-tuned to optimize production without compromising the health of the bacteria, dramatically increasing output. The researchers’ flagship paper, which was published in Nature Biology in 2017, has been cited almost 200 times. The goal at this point is to step up the scale.

    Like many of the mechanisms Prather uses in her research, such switches already exist in biology. Cells whose resources are threatened by neighboring foreign cells will switch from growth mode to producing antibiotics to kill off their competitors, for example. “Cells that make things like antibiotics have a natural way of first making more of themselves, then putting their resources into making product,” she says. “We developed a synthetic way of mimicking nature.”

    Prather’s Berkeley advisor, Keasling, has been using a derivative of the switch inspired by her research. “The tool for channeling metabolic flux—the flow of material through a metabolic pathway—is super-important work that I think will be widely used in the future by metabolic engineers,” he says. “When Kristala publishes something, you know it is going to work.”

    Mentoring young scientists

    Prather receives at least as much recognition for teaching and mentoring as for her research. “She cares deeply about education and is invested in her students in a way that really stands out,” says Keasling. Students describe her optimism and supportiveness, saying that she motivates without commanding. “She created an environment where I was free to make my own mistakes and learn and grow,” says Kevin V. Solomon, SM ’08, PhD ’12, who studied with Prather between 2007 and 2012 and is now an assistant professor of chemical and biomedical engineering at The University of Delaware (US). In some other labs, he notes, “you have hard deadlines, and you perform or you freak out.”

    It was at Merck that Prather realized how much she loves working with young scientists—and it was also where she assembled the management arsenal she uses to run her lab. So, for example, she makes sure to get to know each student’s preferences about communication style, because “treating everyone fairly is not the same as treating everyone the same,” she says. One-on-one meetings commence with a few minutes of chat about general topics, so Prather can suss out students’ states of mind and make sure they are okay. She sets clear standards, intent on avoiding the uncertainty about expectations that is common in academic labs. And when students do raise concerns, “it is important to document and confirm that they have been heard,” she says.

    The most effective leaders model the behaviors they want to see in others. Prather, who received MIT’s Martin Luther King Leadership Award in 2017, expects commitment and high performance from her grad students and postdocs, but not at the cost of their physical or mental health. She discourages working on weekends—to the extent that is possible in biology—and insists that lab members take vacations. And from the beginning she has demonstrated that it is possible to simultaneously do first-class science and have a personal life.

    Prather’s two daughters were both campus kids. She was 31, with a two-month-old baby, when she joined the faculty, and she would nurse her daughter in her office before leaving her at the Institute’s new infant-care facility. Later, she set up a small table and chairs near her desk as a play area. The children have accompanied her on work trips—Prather and her husband took turns watching them when they were small—and frequently attend their mother’s evening and weekend events. Prather recalls turning up for a presentation in 32-123 with both children in tow and setting them up with snacks in the front row. “My daughter promptly dropped the marinara sauce to go with her mozzarella sticks on the floor,” she says. “I was on my hands and knees wiping up red sauce 15 minutes before giving a talk.”

    Prather does set boundaries. She turns down almost every invitation for Friday nights, which is family time. Trips are limited to two a month, and she won’t travel on any family member’s birthday or on her anniversary. But she also welcomes students into her home, where she hosts barbecues and Thanksgiving dinners for anyone without a place to go. “I bring them into my home and into my life,” she says.

    When Solomon was Prather’s student, she even hosted his parents. That hospitality continued after he graduated, when he and his mother ran into his former professor at a conference in Germany. “She graciously kept my mom occupied because she knew I was networking to further my career,” says Solomon.

    It was an act in keeping with Prather’s priorities. Beyond the innovations, beyond the discoveries, her overarching objective is to create independently successful scientists. “The most important thing we do as scientists is to train students and postdocs,” she says. “If your students are well trained and ready to advance knowledge—even if the thing we are working on goes nowhere—to me that is a win.”

    On being Black at MIT-Bearing witness to racism

    As a student at MIT, Kristala Jones Prather ’94 was never the target of racist behavior. But she says other Black students weren’t so lucky. Even though no one challenged her directly, “there was a general atmosphere on campus that questioned the validity of my existence,” she says. Articles in The Tech claimed that affirmative action was diluting the quality of the student pool.

    During her junior year, a group standing on the roof of a frat hurled racial slurs at Black students walking back to their dorm. In response, Prather and another student collaborated with Clarence G. Williams, HM ’09, special assistant to the president, to produce a documentary called It’s Intuitively Obvious about the experience of Black students at MIT.

    “I was involved in a lot of activism to create a climate where students didn’t have to be subjected to the notion that MIT was doing charity,” says Prather. Rather, “it was providing an opportunity for students who had demonstrated their capacity to represent the institution proudly.”

    Prather’s decision to return to MIT as a faculty member was difficult, in part because her Black former classmates, many of whom had experienced overt racism, were discouraging their own children from attending. She worried, too, that she wouldn’t be able to avoid personal attacks this time around. “I didn’t want all the positive feelings I had about MIT to be ruined,” she says.

    Those fears turned out to be unfounded. Prather says she has received tremendous support from her department head and colleagues, as well as abundant leadership opportunities. But she recognizes that not all her peers can say the same. She is guardedly optimistic about the Institute’s current diversity initiative. “We are making progress,” she says. “I am waiting to see if there’s a real commitment to creating an environment where students of color can feel like the Institute is a home for them.”

    See the full article here .


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    The mission of MIT Technology Review (US) is to equip its audiences with the intelligence to understand a world shaped by technology.

  • richardmitnick 4:52 pm on August 24, 2021 Permalink | Reply
    Tags: "A ‘hat trick’ of honors for UD’s Jayaraman", , Arthi Jayaraman, , Chemical engineering, , , ,   

    From University of Delaware (US) : “A ‘hat trick’ of honors for UD’s Jayaraman” 

    U Delaware bloc

    From University of Delaware (US)

    August 23, 2021
    Beth Miller

    Three societies recognize her contributions to physics, chemistry, chemical engineering.

    Photo by Evan Krape
    In the past year, Arthi Jayaraman, Centennial Term Professor for Excellence in Research and Education in the College of Engineering, has been named a fellow of the American Physical Society (US), won an Impact Award from the American Institute of Chemical Engineers (US) and was appointed deputy editor of a journal published by the American Chemical Society (US).

    With a passion for polymer research and teaching, Arthi Jayaraman of the University of Delaware often finds herself wearing a lot of hats — figuratively, at least.

    “My research has me putting on different hats,” said Jayaraman, Centennial Term Professor for Excellence in Research and Education in the College of Engineering. “Sometimes I have to put on the physicist hat, sometimes the chemist hat, and always the engineering hat.”

    In the past year, professional societies in all three disciplines have recognized her work and its value to their field.

    The American Physical Society, which includes many of the world’s most prominent physicists, in March named Jayaraman as a fellow, an honor bestowed on those who have made exceptional contributions to physics. Such fellowships are awarded to fewer than 0.5% of APS’ more than 55,000 members in any given year.

    The American Chemical Society selected Jayaraman to serve as deputy editor of its new, fully open-access journal ACS Polymer Au (Gold).

    The American Institute of Chemical Engineers this summer announced that Jayaraman would receive the 2021 Impact Award, administered by its Computational Molecular Science and Engineering Forum (COMSEF), at the AIChE annual meeting in November.

    Jayaraman leads a computational materials research lab as a professor of chemical and biomolecular engineering and materials science at UD.

    She also loves to teach, loves to be in front of a crowd of eager learners and is devoted to sharing science with the broadest possible audience, making quality science communication a priority.

    “I’m passionate about science, education and training our next best scientists,” she said. “I also believe that the science we create should be shared. I share that in my classroom and with my research community through our papers. I also strongly support that dissemination with a broader community around the world. This motivated me to take on this new editorial role in the new open-access journal ACS Polymer Au.”

    What drives her in all these roles is her love for polymers, substances made up of long chains of uniform molecules. They are everywhere and make amazing building blocks, whether they are produced naturally (silk, hair, DNA for example) or synthetically (plastics, for example).

    “They can be in tires, in rocket ships, on a plane and they can be designed to carry a drug into the human body,” she said. “We’re all made of biopolymers, chain molecules that have a unique chemistry programmed in.”

    Working at different scales requires the kind of expertise her team has.

    “Polymers have non-trivial structures at different scales — Angstrom scale, nanoscale and micron scale,” she said. “To study these materials computationally, one has to select or develop the right model that captures that structure at the scale of interest. One model doesn’t fit all, and that adaptability is something my group works on.”

    Her computational expertise pulls many aspects of scientific inquiry together, but she especially cherishes her collaborations with two kinds of researchers, she said — those who synthesize polymers and those who characterize the materials in a wet lab.

    One close-to-home example is Jayaraman’s collaboration with UD’s Kristi Kiick, Blue and Gold Distinguished Professor of Materials Science and Engineering. She worked with Kiick to characterize protein-like polymers, predict their stability and thermodynamic behavior in specific conditions and ensure they will behave the way Kiick and her team want them to behave in their biomedical research.

    That points the way to new materials and better materials.

    Computational skills are essential to advances in research and Jayaraman’s excellence in that work is reflected in the honors received from these three independent scientific societies.

    Recognizing Jayaraman’s research accomplishments, APS cited her “insightful development and use of molecular modeling, simulation and theoretical studies of structure and thermodynamics in polymer nanocomposites, conjugated polymer blends, nucleic acids and thermoresponsive peptide-polymer conjugates.”

    The Impact Award from AIChE COMSEF recognizes outstanding research in computational molecular science and engineering, including methods and applications.

    The editing position with ACS Polymers Au reflects her leadership in polymers research and her communication skill. She and Associate Editor Prof. Harm-Anton Klok of the EPFL (Swiss Federal Institute of Technology in Lausanne) [École polytechnique fédérale de Lausanne](CH) in Lausanne, Switzerland, just released the first issue of the journal.

    “Arthi is the complete package,” said Jan Genzer, S. Frank and Doris Culberson Distinguished Professor of Chemical and Biomolecular Engineering at The North Carolina State University (US), who nominated her for the APS fellowship and was a co-adviser for Jayaraman when she was a doctoral student at N.C. State. “She mentors her students and collaborates with a large group of people. Many of her collaborators are experimentalists and that’s very atypical for people who do simulation and modeling. She is highly sought after by my colleagues who do experiments.”

    The daughter of an engineer and an educator, Jayaraman said she loved computer programming when she was growing up in Madras, India, and that lifelong skill along with her interest in chemical sciences has served her well.

    “My parents were always supportive and were a driving force for me and my sister, who is an accomplished researcher in biophysics,” Jayaraman said. “I was fortunate to have that push and encouragement from my parents. We came from a lower-middle class family. My parents prioritized our education over luxury and that paid off.”

    Jayaraman earned her bachelor of engineering degree in chemical engineering from the Birla Institute of Technology and Science [बिरला इंस्टिट्यूट ऑफ़ टेक्नोलॉजी एंड साइंस] (IN) in Pilani, India, and her doctorate in chemical and biomolecular engineering at N.C. State. She did postdoctoral research at the The University of Illinois Urbana-Champaign (US). Before joining UD in 2014, she was an assistant professor and Patten faculty fellow at The University of Colorado-Boulder (US).

    Her other awards include the Department of Energy (US) Early Career Research Award and young investigator awards from the American Institute of Chemical Engineers (AIChE) and the American Chemical Society (ACS).

    See the full article here .


    Please help promote STEM in your local schools.

    Stem Education Coalition
    U Delaware campus

    The University of Delaware (US) is a public land-grant research university located in Newark, Delaware. University of Delaware (US) is the largest university in Delaware. It offers three associate’s programs, 148 bachelor’s programs, 121 master’s programs (with 13 joint degrees), and 55 doctoral programs across its eight colleges. The main campus is in Newark, with satellite campuses in Dover, the Wilmington area, Lewes, and Georgetown. It is considered a large institution with approximately 18,200 undergraduate and 4,200 graduate students. It is a privately governed university which receives public funding for being a land-grant, sea-grant, and space-grant state-supported research institution.

    University of Delaware (US) is classified among “R1: Doctoral Universities – Very high research activity”. According to The National Science Foundation (US), UD spent $186 million on research and development in 2018, ranking it 119th in the nation. It is recognized with the Community Engagement Classification by the Carnegie Foundation for the Advancement of Teaching.

    University of Delaware (US) is one of only four schools in North America with a major in art conservation. In 1923, it was the first American university to offer a study-abroad program.

    University of Delaware (US) traces its origins to a “Free School,” founded in New London, Pennsylvania in 1743. The school moved to Newark, Delaware by 1765, becoming the Newark Academy. The academy trustees secured a charter for Newark College in 1833 and the academy became part of the college, which changed its name to Delaware College in 1843. While it is not considered one of the colonial colleges because it was not a chartered institution of higher education during the colonial era, its original class of ten students included George Read, Thomas McKean, and James Smith, all three of whom went on to sign the Declaration of Independence. Read also later signed the United States Constitution.

    Science, Technology and Advanced Research (STAR) Campus

    On October 23, 2009, the University of Delaware (US) signed an agreement with Chrysler to purchase a shuttered vehicle assembly plant adjacent to the university for $24.25 million as part of Chrysler’s bankruptcy restructuring plan. The university has developed the 272-acre (1.10 km2) site into the Science, Technology and Advanced Research (STAR) Campus. The site is the new home of University of Delaware (US)’s College of Health Sciences, which includes teaching and research laboratories and several public health clinics. The STAR Campus also includes research facilities for University of Delaware (US)’s vehicle-to-grid technology, as well as Delaware Technology Park, SevOne, CareNow, Independent Prosthetics and Orthotics, and the East Coast headquarters of Bloom Energy. In 2020 [needs an update], University of Delaware (US) expects to open the Ammon Pinozzotto Biopharmaceutical Innovation Center, which will become the new home of the UD-led National Institute for Innovation in Manufacturing Biopharmaceuticals. Also, Chemours recently opened its global research and development facility, known as the Discovery Hub, on the STAR Campus in 2020. The new Newark Regional Transportation Center on the STAR Campus will serve passengers of Amtrak and regional rail.


    The university is organized into nine colleges:

    Alfred Lerner College of Business and Economics
    College of Agriculture and Natural Resources
    College of Arts and Sciences
    College of Earth, Ocean and Environment
    College of Education and Human Development
    College of Engineering
    College of Health Sciences
    Graduate College
    Honors College

    There are also five schools:

    Joseph R. Biden, Jr. School of Public Policy and Administration (part of the College of Arts & Sciences)
    School of Education (part of the College of Education & Human Development)
    School of Marine Science and Policy (part of the College of Earth, Ocean and Environment)
    School of Nursing (part of the College of Health Sciences)
    School of Music (part of the College of Arts & Sciences)

  • richardmitnick 11:38 am on August 7, 2021 Permalink | Reply
    Tags: "New technology will allow important metals to be made more efficiently", , Chemical engineering, Many metals and their compounds must be made into thin films before they can be used in technological products., ,   

    From University of Minnesota Twin Cities (US) : “New technology will allow important metals to be made more efficiently” 


    From University of Minnesota Twin Cities (US)

    August 6, 2021

    By adding combinations of carbon, hydrogen, and oxygen atoms to stubborn, hard-to-evaporate metals like tungsten and platinum, University of Minnesota Twin Cities researchers were able to transform the elements into thin films in a cheaper and safer way. Credit: Bharat Jalan/MBE Lab, University of Minnesota.

    University of Minnesota Twin Cities College of Science and Engineering researchers have invented a cheaper, safer, and simpler technology that will allow a “stubborn” group of metals and metal oxides to be made into thin films used in many electronics, computer components, and other applications.

    The research is published in the PNAS, a peer-reviewed, multidisciplinary, high-impact scientific journal.

    The researchers worked with the University of Minnesota’s Technology Commercialization Office to patent the technology and have already garnered interest from industry.

    Many metals and their compounds must be made into thin films before they can be used in technological products like electronics, displays, fuel cells, or catalytic applications. “Stubborn” metals, however—which include elements like platinum, iridium, ruthenium, and tungsten, among others—are very difficult to convert into thin films because they require extremely high temperatures (usually more than 2,000 degrees Celsius) to evaporate.

    Typically, scientists synthesize these metal films using techniques like sputtering and electron beam evaporation. The latter consists of melting and evaporating metals at high temperatures and allowing a film to form on top of wafers. But, this conventional method is very expensive, uses a lot of energy, and may also be unsafe due to the high voltage used.

    Now, University of Minnesota researchers have developed a way to evaporate these metals at significantly lower temperatures, fewer than 200 degrees Celsius instead of several thousands. By designing and adding organic ligands—combinations of carbon, hydrogen, and oxygen atoms—to the metals, the researchers were able to substantially increase the materials’ vapor pressures, making them easier to evaporate at lower temperatures. Not only is their new technique simpler, but it also makes higher quality materials that are easily scalable.

    “The ability to make new materials with ease and control is essential to transition into a new era of energy economy,” said Bharat Jalan, the senior author of the study, an expert in material synthesis, and an associate professor and Shell Chair in the University of Minnesota Department of Chemical Engineering and Materials Science (CEMS). “There is already a historical link between the innovation in synthesis science and the development of new technology. Millions of dollars go into making materials for various applications. Now, we’ve come up with a simpler and cheaper technology that enables better materials with atomic precision.”

    These metals are used to make myriad products, from semiconductors for computer applications to display technology. Platinum, for example, also makes a great catalyst for energy conversion and storage and is being looked at for use in spintronic devices.

    “Bringing down the cost and complexity of metal deposition while also allowing for deposition of more complex materials like oxides will play a large role in both industrial and research efforts,” said William Nunn, a University of Minnesota chemical engineering and materials science graduate student, the paper’s first author, and a recipient of the department’s Robert V. Mattern Fellowship. “Now that depositing these metals like platinum will become easier, we hope to see renewed interest in the more complex materials which contain these stubborn metals.”

    In addition to Jalan and Nunn, the research team included University of Minnesota Department of Chemical Engineering and Materials Science grad students Anusha Kamath Manjeshwar, Jin Yue, Tristan K. Truttmann, and postdoctoral researcher Anil Rajapitamahuni.

    The research was funded primarily by the Department of Energy (US), with additional support from the Air Force Office of Scientific Research (US) and the National Science Foundation (US).

    See the full article here .


    Please help promote STEM in your local schools.

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    The University of Minnesota Twin Cities (US) is a public research university in Minneapolis and Saint Paul, MN. The Twin Cities campus comprises locations in Minneapolis and St. Paul approximately 3 miles (4.8 km) apart, and the St. Paul location is in neighboring Falcon Heights. The Twin Cities campus is the oldest and largest in the University of Minnesota system and has the sixth-largest main campus student body in the United States, with 51,327 students in 2019-20. It is the flagship institution of the University of Minnesota System, and is organized into 19 colleges, schools, and other major academic units.

    The University was included in a list of Public Ivy universities in 2001. Legislation passed in 1851 to develop the university, and the first college classes were held in 1867. The university is categorized as a Doctoral University – Highest Research Activity (R1) in the Carnegie Classification of Institutions of Higher Education. Minnesota is a member of the Association of American Universities (US) and is ranked 14th in research activity, with $881 million in research and development expenditures in the fiscal year ending June 30, 2015.

    University of Minnesota faculty, alumni, and researchers have won 26 Nobel Prizes and three Pulitzer Prizes. Notable University of Minnesota alumni include two vice presidents of the United States, Hubert Humphrey and Walter Mondale.

  • richardmitnick 9:04 am on July 23, 2021 Permalink | Reply
    Tags: "Team wins competitive DOE award to advance isotope production critical for U.S. science medicine and industry", , , Chemical engineering, , Clemson University (US), DOE's Savannah River National Laboratory (US), Electrochemical engineering, Isotope production and processing techniques, Project: "Electrochemical hydrogen isotope fractionation—fundamental insights leading to process scale up", Separation technologies,   

    From Vanderbilt University (US) : “Team wins competitive DOE award to advance isotope production critical for U.S. science medicine and industry” 

    Vanderbilt U Bloc

    From Vanderbilt University (US)

    Brenda Ellis
    615 343-6314

    Piran Kidambi.

    A Department of Energy (US) $4 million initiative to advance research in isotope production includes a Vanderbilt engineering professor’s work on separation technologies and to scale up processes. The funding is part of a key federal program that produces critical isotopes otherwise unavailable or in short supply for U.S. science, medicine and industry.

    Piran Kidambi, assistant professor of chemical and biomolecular engineering, is part of a team led by DOE’s Savannah River National Laboratory (US) and Clemson University (US) that has received a two-year, $800,000 grant—“Electrochemical hydrogen isotope fractionation—fundamental insights leading to process scale up”—as part of the DOE’s funding for 10 awards across five isotope research efforts. The awards were selected on a competitive basis by peer review.

    Isotopes, or variations of the same elements with the same number of protons but different numbers of neutrons, have unique properties that can make them useful in medical diagnostic and treatment applications. They also are important for applications in quantum information science, nuclear power, national security and more.

    “Given the very minor differences in mass, or physical properties, as well as very similar chemical properties between isotopes, separation of one isotope from the other is inherently challenging,” said Kidambi. “Traditionally, this has been accomplished in energy intensive processes with potential for adverse environmental impact.” Kidambi’s proposed project aims to use fundamental understanding of a separation processes using novel membranes to enable process design and scale up for isotope separation. The team includes the lead organization Savannah River National Laboratory and Clemson University.

    The award recipients include six universities and three DOE national laboratories.

    University of Missouri (US)

    DOE’s Brookhaven National Laboratory (US)

    University of Washington (US)

    Columbia University (US)

    University of Wisconsin‐Madison (US)

    DOE’s Savannah River National Laboratory (US)

    Clemson University (US)

    Vanderbilt University (US)

    DOE’s Oak Ridge National Laboratory (US)

    Most of the awards go to collaborative teams where universities and national laboratories work together.

    Topics funded by the DOE include efforts to increase the availability of new cancer diagnostic and therapeutic agents to the medical community and broad improvements to isotope production and processing techniques with the goal of enhancing isotope availability and purity.

    “Isotopes play an absolutely vital role in countless areas of science, medicine, industry, and even national and homeland security today,” said Jehanne Gillo, director of the DOE Isotope Program, in the DOE’s announcement. “These R&D activities will continue our efforts to ensure the availability of isotopes critical to Americans’ health, prosperity, and security that would be otherwise impossible to obtain.”

    See the full article here .


    Please help promote STEM in your local schools.

    Stem Education Coalition

    Commodore Cornelius Vanderbilt was in his 79th year when he decided to make the gift that founded Vanderbilt University (US) in the spring of 1873.
    The $1 million that he gave to endow and build the university was the commodore’s only major philanthropy. Methodist Bishop Holland N. McTyeire of Nashville, husband of Amelia Townsend who was a cousin of the commodore’s young second wife Frank Crawford, went to New York for medical treatment early in 1873 and spent time recovering in the Vanderbilt mansion. He won the commodore’s admiration and support for the project of building a university in the South that would “contribute to strengthening the ties which should exist between all sections of our common country.”

    McTyeire chose the site for the campus, supervised the construction of buildings and personally planted many of the trees that today make Vanderbilt a national arboretum. At the outset, the university consisted of one Main Building (now Kirkland Hall), an astronomical observatory and houses for professors. Landon C. Garland was Vanderbilt’s first chancellor, serving from 1875 to 1893. He advised McTyeire in selecting the faculty, arranged the curriculum and set the policies of the university.

    For the first 40 years of its existence, Vanderbilt was under the auspices of the Methodist Episcopal Church, South. The Vanderbilt Board of Trust severed its ties with the church in June 1914 as a result of a dispute with the bishops over who would appoint university trustees.

    From the outset, Vanderbilt met two definitions of a university: It offered work in the liberal arts and sciences beyond the baccalaureate degree and it embraced several professional schools in addition to its college. James H. Kirkland, the longest serving chancellor in university history (1893-1937), followed Chancellor Garland. He guided Vanderbilt to rebuild after a fire in 1905 that consumed the main building, which was renamed in Kirkland’s honor, and all its contents. He also navigated the university through the separation from the Methodist Church. Notable advances in graduate studies were made under the third chancellor, Oliver Cromwell Carmichael (1937-46). He also created the Joint University Library, brought about by a coalition of Vanderbilt, Peabody College and Scarritt College.

    Remarkable continuity has characterized the government of Vanderbilt. The original charter, issued in 1872, was amended in 1873 to make the legal name of the corporation “The Vanderbilt University.” The charter has not been altered since.

    The university is self-governing under a Board of Trust that, since the beginning, has elected its own members and officers. The university’s general government is vested in the Board of Trust. The immediate government of the university is committed to the chancellor, who is elected by the Board of Trust.

    The original Vanderbilt campus consisted of 75 acres. By 1960, the campus had spread to about 260 acres of land. When George Peabody College for Teachers merged with Vanderbilt in 1979, about 53 acres were added.

    Vanderbilt’s student enrollment tended to double itself each 25 years during the first century of the university’s history: 307 in the fall of 1875; 754 in 1900; 1,377 in 1925; 3,529 in 1950; 7,034 in 1975. In the fall of 1999 the enrollment was 10,127.

    In the planning of Vanderbilt, the assumption seemed to be that it would be an all-male institution. Yet the board never enacted rules prohibiting women. At least one woman attended Vanderbilt classes every year from 1875 on. Most came to classes by courtesy of professors or as special or irregular (non-degree) students. From 1892 to 1901 women at Vanderbilt gained full legal equality except in one respect — access to dorms. In 1894 the faculty and board allowed women to compete for academic prizes. By 1897, four or five women entered with each freshman class. By 1913 the student body contained 78 women, or just more than 20 percent of the academic enrollment.

    National recognition of the university’s status came in 1949 with election of Vanderbilt to membership in the select Association of American Universities (US). In the 1950s Vanderbilt began to outgrow its provincial roots and to measure its achievements by national standards under the leadership of Chancellor Harvie Branscomb. By its 90th anniversary in 1963, Vanderbilt for the first time ranked in the top 20 private universities in the United States.

    Vanderbilt continued to excel in research, and the number of university buildings more than doubled under the leadership of Chancellors Alexander Heard (1963-1982) and Joe B. Wyatt (1982-2000), only the fifth and sixth chancellors in Vanderbilt’s long and distinguished history. Heard added three schools (Blair, the Owen Graduate School of Management and Peabody College) to the seven already existing and constructed three dozen buildings. During Wyatt’s tenure, Vanderbilt acquired or built one-third of the campus buildings and made great strides in diversity, volunteerism and technology.

    The university grew and changed significantly under its seventh chancellor, Gordon Gee, who served from 2000 to 2007. Vanderbilt led the country in the rate of growth for academic research funding, which increased to more than $450 million and became one of the most selective undergraduate institutions in the country.

    On March 1, 2008, Nicholas S. Zeppos was named Vanderbilt’s eighth chancellor after serving as interim chancellor beginning Aug. 1, 2007. Prior to that, he spent 2002-2008 as Vanderbilt’s provost, overseeing undergraduate, graduate and professional education programs as well as development, alumni relations and research efforts in liberal arts and sciences, engineering, music, education, business, law and divinity. He first came to Vanderbilt in 1987 as an assistant professor in the law school. In his first five years, Zeppos led the university through the most challenging economic times since the Great Depression, while continuing to attract the best students and faculty from across the country and around the world. Vanderbilt got through the economic crisis notably less scathed than many of its peers and began and remained committed to its much-praised enhanced financial aid policy for all undergraduates during the same timespan. The Martha Rivers Ingram Commons for first-year students opened in 2008 and College Halls, the next phase in the residential education system at Vanderbilt, is on track to open in the fall of 2014. During Zeppos’ first five years, Vanderbilt has drawn robust support from federal funding agencies, and the Medical Center entered into agreements with regional hospitals and health care systems in middle and east Tennessee that will bring Vanderbilt care to patients across the state.

    Today, Vanderbilt University is a private research university of about 6,500 undergraduates and 5,300 graduate and professional students. The university comprises 10 schools, a public policy center and The Freedom Forum First Amendment Center. Vanderbilt offers undergraduate programs in the liberal arts and sciences, engineering, music, education and human development as well as a full range of graduate and professional degrees. The university is consistently ranked as one of the nation’s top 20 universities by publications such as U.S. News & World Report, with several programs and disciplines ranking in the top 10.

    Cutting-edge research and liberal arts, combined with strong ties to a distinguished medical center, creates an invigorating atmosphere where students tailor their education to meet their goals and researchers collaborate to solve complex questions affecting our health, culture and society.

    Vanderbilt, an independent, privately supported university, and the separate, non-profit Vanderbilt University Medical Center share a respected name and enjoy close collaboration through education and research. Together, the number of people employed by these two organizations exceeds that of the largest private employer in the Middle Tennessee region.

  • richardmitnick 11:21 am on July 5, 2021 Permalink | Reply
    Tags: "Machine learning cracks the oxidation states of crystal structures", , As of 2016 we know of 118 elements all of which can be found categorized in the famous periodic table., Chemical engineering, ,   

    From Swiss Federal Institute of Technology in Lausanne [EPFL-École Polytechnique Fédérale de Lausanne] (CH): “Machine learning cracks the oxidation states of crystal structures” 

    From Swiss Federal Institute of Technology in Lausanne [EPFL-École Polytechnique Fédérale de Lausanne] (CH)

    Nik Papageorgiou

    Chemical engineers at EPFL have developed a machine-learning model that can predict a compound’s oxidation state, a property that is so essential that many chemists argue it must be included in the periodic table.


    Chemical elements make up pretty much everything in the physical world. As of 2016 we know of 118 elements all of which can be found categorized in the famous periodic table that hangs in every chemistry lab and classroom.

    Each element in the periodic table appears as a one-, two-letter abbreviation (e.g. O for oxygen, Al for aluminum) along with its atomic number, which shows how many protons there are in the element’s nucleus. The number of protons is enormously important, as it also determines how many electrons orbit the nucleus, which essentially makes the element what it is and gives it its chemical properties. In short, the atomic number is an element’s ID card.

    The periodic table should include oxidation states.

    Publishing in Nature Chemistry, chemical engineers at EPFL’s School of Basic Sciences investigate another number that must be reported for each element in the periodic table: the element’s oxidation state, also known as oxidation number. Simply put, the oxidation state describes how many electrons an atom must gain or lose in order to form a chemical bond with another atom.

    “In chemistry, the oxidation state is always reported in the chemical name of a compound,” says Professor Berend Smit who led the research. “Oxidation states play such an important role in the fundamentals of chemistry that some have argued that they should be represented as the third dimension of the periodic table.” A good example is chromium: in oxidation state III it is essential to the human body; in oxidation state IV, it is extremely toxic.

    Complex materials complicate things

    But although figuring out the oxidation state of a single element is pretty straightforward, when it comes to compounds made up of multiple elements, things become complicated. “For complex materials, it is in practice impossible to predict the oxidation state from first principles,” says Smit. “In fact, most quantum programs require the oxidation state of the metal as input.”

    The current state-of-the-art in predicting oxidation states is still based on a something called “bond valence theory” developed in the early 20th century, which estimates the oxidation state of a compound based on the distances between the atoms of its constituent elements. But this doesn’t always work, especially in materials with crystal structures. “It is well known that it is not only the distance that matters but also the geometry of a metal complex,” says Smit. “But attempts to take this into account have not been very successful.”

    A machine-learning solution

    Until now, that is. In the study, the researchers were able to train a machine-learning algorithm to categorize a famous group of materials, the metal-organic frameworks, by oxidation state.

    The team used the Cambridge structural database, a repository of crystal structures in which the oxidation state in given in the name of the materials. “The database is very messy, with many errors and a mixture of experiments, expert guesses, and different variations of the bond valence theory are used to assign oxidation states,” says Smit. “We assume that chemistry is self-correcting,” he adds. “So while there are many errors on individual accounts, the community as a whole will get it right.”

    “We basically made a machine-learning model that has captured the collective knowledge of the chemistry community,” says Kevin Jablonka, a PhD student in Smit’s group at EPFL. “Our machine learning is nothing more than the television game “Who Wants To Be A Millionaire?” If a chemist does not know the oxidation state, one of the lifelines is to ask the audience of chemistry what they think the oxidation state should be. By uploading a crystal structure and our machine-learned model is the audience of chemists that will tell them what the most likely oxidation state is.”

    See the full article here .


    Please help promote STEM in your local schools.

    Stem Education Coalition

    EPFL bloc

    EPFL campus

    The Swiss Federal Institute of Technology in Lausanne [EPFL-École polytechnique fédérale de Lausanne] (CH) is a research institute and university in Lausanne, Switzerland, that specializes in natural sciences and engineering. It is one of the two Swiss Federal Institutes of Technology, and it has three main missions: education, research and technology transfer.

    The QS World University Rankings ranks EPFL(CH) 14th in the world across all fields in their 2020/2021 ranking, whereas Times Higher Education World University Rankings ranks EPFL(CH) as the world’s 19th best school for Engineering and Technology in 2020.

    EPFL(CH) is located in the French-speaking part of Switzerland; the sister institution in the German-speaking part of Switzerland is the Swiss Federal Institute of Technology ETH Zürich [Eidgenössische Technische Hochschule Zürich)](CH). Associated with several specialized research institutes, the two universities form the Domain of the Swiss Federal Institutes of Technology (ETH Domain) [ETH-Bereich; Domaine des Écoles polytechniques fédérales](CH), which is directly dependent on the Federal Department of Economic Affairs, Education and Research. In connection with research and teaching activities, EPFL(CH) operates a nuclear reactor CROCUS; a Tokamak Fusion reactor; a Blue Gene/Q Supercomputer; and P3 bio-hazard facilities.

    The roots of modern-day EPFL(CH) can be traced back to the foundation of a private school under the name École spéciale de Lausanne in 1853 at the initiative of Lois Rivier, a graduate of the École Centrale Paris (FR) and John Gay the then professor and rector of the Académie de Lausanne. At its inception it had only 11 students and the offices was located at Rue du Valentin in Lausanne. In 1869, it became the technical department of the public Académie de Lausanne. When the Académie was reorganised and acquired the status of a university in 1890, the technical faculty changed its name to École d’ingénieurs de l’Université de Lausanne. In 1946, it was renamed the École polytechnique de l’Université de Lausanne (EPUL). In 1969, the EPUL was separated from the rest of the University of Lausanne and became a federal institute under its current name. EPFL(CH), like ETH Zürich(CH), is thus directly controlled by the Swiss federal government. In contrast, all other universities in Switzerland are controlled by their respective cantonal governments. Following the nomination of Patrick Aebischer as president in 2000, EPFL(CH) has started to develop into the field of life sciences. It absorbed the Swiss Institute for Experimental Cancer Research (ISREC) in 2008.

    In 1946, there were 360 students. In 1969, EPFL(CH) had 1,400 students and 55 professors. In the past two decades the university has grown rapidly and as of 2012 roughly 14,000 people study or work on campus, about 9,300 of these being Bachelor, Master or PhD students. The environment at modern day EPFL(CH) is highly international with the school attracting students and researchers from all over the world. More than 125 countries are represented on the campus and the university has two official languages, French and English.


    EPFL is organised into eight schools, themselves formed of institutes that group research units (laboratories or chairs) around common themes:

    School of Basic Sciences (SB, Jan S. Hesthaven)

    Institute of Mathematics (MATH, Victor Panaretos)
    Institute of Chemical Sciences and Engineering (ISIC, Emsley Lyndon)
    Institute of Physics (IPHYS, Harald Brune)
    European Centre of Atomic and Molecular Computations (CECAM, Ignacio Pagonabarraga Mora)
    Bernoulli Center (CIB, Nicolas Monod)
    Biomedical Imaging Research Center (CIBM, Rolf Gruetter)
    Interdisciplinary Center for Electron Microscopy (CIME, Cécile Hébert)
    Max Planck-EPFL Centre for Molecular Nanosciences and Technology (CMNT, Thomas Rizzo)
    Swiss Plasma Center (SPC, Ambrogio Fasoli)
    Laboratory of Astrophysics (LASTRO, Jean-Paul Kneib)

    School of Engineering (STI, Ali Sayed)

    Institute of Electrical Engineering (IEL, Giovanni De Micheli)
    Institute of Mechanical Engineering (IGM, Thomas Gmür)
    Institute of Materials (IMX, Michaud Véronique)
    Institute of Microengineering (IMT, Olivier Martin)
    Institute of Bioengineering (IBI, Matthias Lütolf)

    School of Architecture, Civil and Environmental Engineering (ENAC, Claudia R. Binder)

    Institute of Architecture (IA, Luca Ortelli)
    Civil Engineering Institute (IIC, Eugen Brühwiler)
    Institute of Urban and Regional Sciences (INTER, Philippe Thalmann)
    Environmental Engineering Institute (IIE, David Andrew Barry)

    School of Computer and Communication Sciences (IC, James Larus)

    Algorithms & Theoretical Computer Science
    Artificial Intelligence & Machine Learning
    Computational Biology
    Computer Architecture & Integrated Systems
    Data Management & Information Retrieval
    Graphics & Vision
    Human-Computer Interaction
    Information & Communication Theory
    Programming Languages & Formal Methods
    Security & Cryptography
    Signal & Image Processing

    School of Life Sciences (SV, Gisou van der Goot)

    Bachelor-Master Teaching Section in Life Sciences and Technologies (SSV)
    Brain Mind Institute (BMI, Carmen Sandi)
    Institute of Bioengineering (IBI, Melody Swartz)
    Swiss Institute for Experimental Cancer Research (ISREC, Douglas Hanahan)
    Global Health Institute (GHI, Bruno Lemaitre)
    Ten Technology Platforms & Core Facilities (PTECH)
    Center for Phenogenomics (CPG)
    NCCR Synaptic Bases of Mental Diseases (NCCR-SYNAPSY)

    College of Management of Technology (CDM)

    Swiss Finance Institute at EPFL (CDM-SFI, Damir Filipovic)
    Section of Management of Technology and Entrepreneurship (CDM-PMTE, Daniel Kuhn)
    Institute of Technology and Public Policy (CDM-ITPP, Matthias Finger)
    Institute of Management of Technology and Entrepreneurship (CDM-MTEI, Ralf Seifert)
    Section of Financial Engineering (CDM-IF, Julien Hugonnier)

    College of Humanities (CDH, Thomas David)

    Human and social sciences teaching program (CDH-SHS, Thomas David)

    EPFL Middle East (EME, Dr. Franco Vigliotti)[62]

    Section of Energy Management and Sustainability (MES, Prof. Maher Kayal)

    In addition to the eight schools there are seven closely related institutions

    Swiss Cancer Centre
    Center for Biomedical Imaging (CIBM)
    Centre for Advanced Modelling Science (CADMOS)
    École cantonale d’art de Lausanne (ECAL)
    Campus Biotech
    Wyss Center for Bio- and Neuro-engineering
    Swiss National Supercomputing Centre

  • richardmitnick 5:09 pm on February 5, 2021 Permalink | Reply
    Tags: "Breakthrough in Quantum Photonics Promises a New Era in Optical Circuits", A quantum optical circuit uses light sources that generate individual light particles or photons on-demand one-at-a-time acting as information carrying bits., , Chemical engineering, , For the first time researchers can create scalable quantum photonic chips using well-established semiconductor processing techniques., In recently published work researchers at USC have shown that single photons can indeed be emitted in a uniform way from quantum dots arranged in a precise pattern., , , , , The method of aligning quantum dots was first developed at USC by the lead PI Professor Anupam Madhukar and his team nearly thirty years ago., The optical circuit requires these single photon sources to be arranged on a semiconductor chip in a regular pattern., These light sources are nano-sized semiconductor “quantum dots”., This work also sets a new world-record of ordered and scalable quantum dots in terms of the simultaneous purity of single-photon emission greater than 99.5%., , Until now there has been a significant barrier to the development of such circuits.,   

    From USC Viterbi School of Engineering at University of Southern California: “Breakthrough in Quantum Photonics Promises a New Era in Optical Circuits” 

    From USC Viterbi School of Engineering


    USC bloc

    University of Southern California

    February 3, 2021
    Greta Harrison

    A world-first method to enable quantum optical circuits that use photons—light particles—heralds a new future for secure communication and quantum computing.

    Photon Waves. Credit: Wikimedia Commons.

    The modern world is powered by electrical circuitry on a “chip”—the semiconductor chip underpinning computers, cell phones, the internet, and other applications. In the year 2025, humans are expected to be creating 175 zettabytes (175trillion gigabytes) of new data. How can we ensure the security of sensitive data at such a high volume? And how can we address grand-challenge-like problems, from privacy and security to climate change, leveraging this data, especially given the limited capability of current computers?

    A promising alternative is emerging quantum communication and computation technologies . For this to happen, however, it will require the widespread development of powerful new quantum optical circuits­; circuits that are capable of securely processing the massive amounts of information we generate every day. Researchers in USC’s Mork Family Department of Chemical Engineering and Materials Science have made a breakthrough to help enable this technology.

    While a traditional electrical circuit is a pathway along which electrons from an electric charge flow, a quantum optical circuit uses light sources that generate individual light particles, or photons, on-demand, one-at-a-time, acting as information carrying bits (quantum bits or qubits). These light sources are nano-sized semiconductor “quantum dots”–tiny manufactured collections of tens of thousands to a million atoms packed within a volume of linear size less than a thousandth of the thickness of typical human hair buried in a matrix of another suitable semiconductor.

    They have so far been proven to be the most versatile on-demand single photon generators. The optical circuit requires these single photon sources to be arranged on a semiconductor chip in a regular pattern. Photons with nearly identical wavelength from the sources must then be released in a guided direction. This allows them to be manipulated to form interactions with other photons and particles to transmit and process information.

    Until now, there has been a significant barrier to the development of such circuits. For example, in current manufacturing techniques quantum dots have different sizes and shapes and assemble on the chip in random locations. The fact that the dots have different sizes and shapes mean that the photons they release do not have uniform wavelengths. This and the lack of positional order make them unsuitable for use in the development of optical circuits.

    In recently published work, researchers at USC have shown that single photons can indeed be emitted in a uniform way from quantum dots arranged in a precise pattern. It should be noted that the method of aligning quantum dots was first developed at USC by the lead PI, Professor Anupam Madhukar, and his team nearly thirty years ago, well before the current explosive research activity in quantum information and interest in on-chip single-photon sources. In this latest work, the USC team has used such methods to create single-quantum dots, with their remarkable single-photon emission characteristics. It is expected that the ability to precisely align uniformly-emitting quantum dots will enable the production of optical circuits, potentially leading to novel advancements in quantum computing and communications technologies.

    The work, published in APL Photonics, was led by Jiefei Zhang, currently a research assistant professor in the Mork Family Department of Chemical Engineering and Materials Science, with corresponding author Anupam Madhukar, Kenneth T. Norris Professor in Engineering and Professor of Chemical Engineering, Electrical Engineering, Materials Science, and Physics.

    “The breakthrough paves the way to the next steps required to move from lab demonstration of single photon physics to chip-scale fabrication of quantum photonic circuits,” Zhang said. “This has potential applications in quantum (secure) communication, imaging, sensing and quantum simulations and computation.”

    Madhukar said that it is essential that quantum dots be ordered in a precise way so that photons released from any two or more dots can be manipulated to connect with each other on the chip. This will form the basis of building unit for quantum optical circuits.

    “If the source where the photons come from is randomly located, this can’t be made to happen.” Madhukar said.

    “The current technology that is allowing us to communicate online, for instance using a technological platform such as Zoom, is based on the silicon integrated electronic chip. If the transistors on that chip are not placed in exact designed locations, there would be no integrated electrical circuit,” Madhukar said. “It is the same requirement for photon sources such as quantum dots to create quantum optical circuits.”

    The research is supported by the Air Force Office of Scientific Research (AFOSR) and the U.S. Army Research Office (ARO).

    “This advance is an important example of how solving fundamental materials science challenges, like how to create quantum dots with precise position and composition, can have big downstream implications for technologies like quantum computing,” said Evan Runnerstrom, program manager, Army Research Office, an element of the U.S. Army Combat Capabilities Development Command’s Army Research Laboratory. “This shows how ARO’s targeted investments in basic research support the Army’s enduring modernization efforts in areas like networking.”

    To create the precise layout of quantum dots [Stress-Engineered Quantum Dots: Nature’s Way] for the circuits, the team used a method called SESRE (substrate-encoded size-reducing epitaxy) developed in the Madhukar group in the early 1990s. In the current work, the team fabricated regular arrays of nanometer-sized mesas (Fig. 1(a)) with a defined edge orientation, shape (sidewalls) and depth on a flat semiconductor substrate, composed of gallium arsenide (GaAs). Quantum dots are then created on top of the mesas by adding appropriate atoms using the following technique.

    Figure. (a) Scanning electron microscope (SEM) image of starting nanometer-sized mesa array created on a flat semiconductor substrate; (b) Schematic of mesa profile evolution during material deposition with the black arrows indicating atom migration direction leading first to GaAs size-reduction (the SESRE approach) and then switching to the deposition of quantum dot material InAs (red) on the size-reduced mesa top and back to GaAs to bury the red InAs; A SEM image of the mesa bearing the single quantum dot is shown below; (c) Indicates the realized quantum dot array buried under a planarized GaAs surface shown symbolically as a translucent overlayer to enable visualization (GaAs is opaque).

    First, incoming gallium (Ga) atoms gather on the top of the nanoscale mesas (black arrows in Fig 1.(b)) attracted by surface energy forces, where they deposit GaAs (black outline on mesa top, Fig. 1(b)). Then, the incoming flux is switched to indium (In) atoms, to in turn deposit indium arsenide (InAs) (red region in Fig. 1(b)), followed back by Ga atoms to form GaAs and hence create the desired individual quantum dots (upper image in Fig. 1(b)) that end up releasing single photons. To be useful for creating optical circuits, the space between the pyramid-shaped nano-mesas needs to be filled by material that flattens the surface. The final chip is shown schematically in Fig. 1(c), where opaque GaAs is depicted as a translucent overlayer under which the quantum dots are located.

    “This work also sets a new world-record of ordered and scalable quantum dots in terms of the simultaneous purity of single-photon emission greater than 99.5%, and in terms of the uniformity of the wavelength of the emitted photons, which can be as narrow as 1.8nm, which is a factor of 20 to 40 better than typical quantum dots,” Zhang said.

    Zhang said that with this uniformity, it becomes feasible to apply established methods such as local heating or electric fields to fine-tune the photon wavelengths of the quantum dots to exactly match each other, which is necessary for creating the required interconnections between different quantum dots for circuits.

    This means that for the first time researchers can create scalable quantum photonic chips using well-established semiconductor processing techniques. In addition, the team’s efforts are now focused on establishing how identical the emitted photons are from the same and/or from different quantum dots. The degree of indistinguishability is central to quantum effects of interference and entanglement, that underpin quantum information processing –communication, sensing, imaging, or computing.

    Zhang concluded: “We now have an approach and a material platform to provide scalable and ordered sources generating potentially indistinguishable single-photons for quantum information applications. The approach is general and can be used for other suitable material combinations to create quantum dots emitting over a wide range of wavelengths preferred for different applications, for example fiber-based optical communication or the mid-infrared regime, suited for environmental monitoring and medical diagnostics,” Zhang said.

    Gernot S. Pomrenke, AFOSR Program Officer, Optoelectronics and Photonics said that reliable arrays of on-demand single photon sources on-chip were a major step forward.

    “This impressive growth and material science work stretches over three decades of dedicated effort before research activities in quantum information were in the mainstream,” Pomrenke said. “Initial AFOSR funding and resources from other DoD agencies have been critical in realizing the challenging work and vision by Madhukar, his students, and collaborators. There is a great likelihood that the work will revolutionize the capabilities of data centers, medical diagnostics, defense and related technologies.”

    The paper’s co-authors include Qi Huang and Lucas Jordao from USC’s Mork Family Department of Chemical Engineering and Materials Science, Swarnabha Chattaraj from the Ming Hsieh Department of Electrical and Computer Engineering and Siyuan Lu from the IBM Thomas J. Watson Research Center.

    See the full article here .


    Please help promote STEM in your local schools.

    Stem Education Coalition

    The USC Viterbi School of Engineering (formerly the USC School of Engineering) is located at the University of Southern California in the United States. It was renamed following a $52 million donation by Andrew Viterbi, co-founder of Qualcomm Inc. The USC Viterbi School of Engineering celebrated its 100th birthday in conjunction with the university’s 125th birthday.

    With over $135 million in external funding support, the school is among the nation’s highest in volume of research activity.

    Research centers have played a major role in development of multiple technologies, including early development of the Internet when USC researcher Jonathan Postel was an editor of communications-protocol for the fledgling internet, also known as ARPANET.

    Major research centers

    Alfred Mann Institute – business incubator for medical device development in preparation for commercialization

    Center for Biomimetic Microelectronic Systems – National Science Foundation Engineering Research Center

    Center for Risk and Economic Analysis of Terrorism Events (CREATE) – interdisciplinary national research center funded by the U.S. Department of Homeland Security

    Center for Systems and Software Engineering (CSSE) – research the relationship between systems, software, and users.

    Collaborative High Altitude Flow Facility (CHAFF) – Space and Vacuum Science research group, a funded Air Force Research Laboratory

    Information Sciences Institute (housed at a separate facilities in Marina del Rey, California and Arlington, Virginia) – played a major role in the development of the Internet, and continues to be a major research center in computer science

    Institute for Creative Technologies – conducts research in virtual reality and immersive digital environment

    Integrated Media Systems Center – National Science Foundation’s Exclusive Engineering Research Center for multimedia and Internet research

    Pacific Earthquake Engineering Research Center (PEER) Partner Institution – Current Research

    USC campus

    The University of Southern California is one of the world’s leading private research universities. An anchor institution in Los Angeles, a global center for arts, technology and international business, USC’s diverse curricular offerings provide extensive opportunities for interdisciplinary study, and collaboration with leading researchers in highly advanced learning environments. With a strong tradition of integrating liberal and professional education, USC fosters a vibrant culture of public service and encourages students to cross academic as well as geographic boundaries in their pursuit of knowledge.

  • richardmitnick 9:33 am on January 25, 2021 Permalink | Reply
    Tags: "Researchers use lasers and molecular tethers to create perfectly patterned platforms for tissue engineering", A biologically compatible 3D scaffold in which cells can grow, , , Biomaterials, Chemical engineering, Decorate the biologically compatible 3D scaffold with biochemical messages in the correct configuration to trigger the formation of the desired organ or tissue., , Laboratory-grown organs and tissues, , Light-based methods to modify synthetic scaffolds with protein signals, mCherry proteins, , , Protein-based biochemical messages that affect cell behavior, The signals that the team added to the hydrogels are proteins., The tethered proteins were fully functional delivering desired signals to cells., Two types of biological polymers: collagen and fibrin,   

    From University of Washington: “Researchers use lasers and molecular tethers to create perfectly patterned platforms for tissue engineering” 

    From University of Washington

    January 18, 2021
    James Urton

    Top view of a collagen hydrogel that researchers decorated with immobilized mCherry proteins, which glow red under fluorescent light. The team shined UV light on the hydrogel through a mask cut out in the shape of a former University of Washington logo. Black regions were masked from the light, and so the mCherry protein did not adhere to those portions of the hydrogel. Scale bar is 50 micrometers.Batalov et al., PNAS, 2021.

    Top view of two collagen hydrogels that researchers decorated with immobilized mCherry proteins, which glow red under fluorescent light. The team scanned near-infrared lasers in the shapes of a monster (left) and the Space Needle (right) to create these patterns. Black regions were not scanned with the laser, and so the mCherry protein did not adhere to those portions of the hydrogel. Scale bar is 50 micrometers.Batalov et al., PNAS, 2021.

    The team used near-infrared lasers to create this intricate pattern in the shape of a human heart of immobilized mCherry proteins, which glow red under fluorescent light, within a collagen hydrogel. On the left is a composite image of 3D slices from the gel. On the right are cross-sectional views of the mCherry patterns. Scale bar is 50 micrometers.Batalov et al., PNAS, 2021.

    This is a top view of a cylindrical fibrin hydrogel. By design, the right side of the hydrogel contains immobilized Delta-1 proteins, which activate Notch signaling pathways within cells. The left side does not contain immobilized Delta-1 (see insert). The team introduced human bone cancer cells, which were engineered to glow when their Notch signaling pathways are activated, into the hydrogel. The right side of the hydrogel glows brightly, indicating that cells in that region have activated their Notch signaling pathways. Cells on the left side of the hydrogel have not. Scale bar is 1 millimeter.Batalov et al., PNAS, 2021.

    Imagine going to a surgeon to have a diseased or injured organ switched out for a fully functional, laboratory-grown replacement. This remains science fiction and not reality because researchers today struggle to organize cells into the complex 3D arrangements that our bodies can master on their own.

    There are two major hurdles to overcome on the road to laboratory-grown organs and tissues. The first is to use a biologically compatible 3D scaffold in which cells can grow. The second is to decorate that scaffold with biochemical messages in the correct configuration to trigger the formation of the desired organ or tissue.

    In a major step toward transforming this hope into reality, researchers at the University of Washington have developed a technique to modify naturally occurring biological polymers with protein-based biochemical messages that affect cell behavior. Their approach, published the week of Jan. 18 in the PNAS, uses a near-infrared laser to trigger chemical adhesion of protein messages to a scaffold made from biological polymers such as collagen, a connective tissue found throughout our bodies.

    Mammalian cells responded as expected to the adhered protein signals within the 3D scaffold, according to senior author Cole DeForest, a UW associate professor of chemical engineering and of bioengineering. The proteins on these biological scaffolds triggered changes to messaging pathways within the cells that affect cell growth, signaling and other behaviors.

    These methods could form the basis of biologically based scaffolds that might one day make functional laboratory-grown tissues a reality, said DeForest, who is also a faculty member with the UW Molecular Engineering and Sciences Institute and the UW Institute for Stem Cell and Regenerative Medicine.

    “This approach provides us with the opportunities we’ve been waiting for to exert greater control over cell function and fate in naturally derived biomaterials — not just in three-dimensional space but also over time,” said DeForest. “Moreover, it makes use of exceptionally precise photochemistries that can be controlled in 4D while uniquely preserving protein function and bioactivity.”

    DeForest’s colleagues on this project are lead author Ivan Batalov, a former UW postdoctoral researcher in chemical engineering and bioengineering, and co-author Kelly Stevens, a UW assistant professor of bioengineering and of laboratory medicine and pathology.

    Their method is a first for the field, spatially controlling cell function inside naturally occurring biological materials as opposed to those that are synthetically derived. Several research groups, including DeForest’s, have developed light-based methods to modify synthetic scaffolds with protein signals. But natural biological polymers can be a more attractive scaffold for tissue engineering because they innately possess biochemical characteristics that cells rely on for structure, communication and other purposes.

    “A natural biomaterial like collagen inherently includes many of the same signaling cues as those found in native tissue,” said DeForest. “In many cases, these types of materials keep cells ‘happier’ by providing them with similar signals to those they would encounter in the body.”

    They worked with two types of biological polymers: collagen and fibrin, a protein involved in blood clotting. They assembled each into fluid-filled scaffolds known as hydrogels.

    The signals that the team added to the hydrogels are proteins, one of the main messengers for cells. Proteins come in many forms, all with their own unique chemical properties. As a result, the researchers designed their system to employ a universal mechanism to attach proteins to a hydrogel — the binding between two chemical groups, an alkoxyamine and an aldehyde. Prior to hydrogel assembly, they decorated the collagen or fibrin precursors with alkoxyamine groups, all physically blocked with a “cage” to prevent the alkoxyamines from reacting prematurely. The cage can be removed with ultraviolet light or a near-infrared laser.

    Using methods previously developed in DeForest’s laboratory, the researchers also installed aldehyde groups to one end of the proteins they wanted to attach to the hydrogels. They then combined the aldehyde-bearing proteins with the alkoxyamine-coated hydrogels, and used a brief pulse of light to remove the cage covering the alkoxyamine. The exposed alkoxyamine readily reacted with the aldehyde group on the proteins, tethering them within the hydrogel. The team used masks with patterns cut into them, as well as changes to the laser scan geometries, to create intricate patterns of protein arrangements in the hydrogel — including an old UW logo, Seattle’s Space Needle, a monster and the 3D layout of the human heart.

    The tethered proteins were fully functional, delivering desired signals to cells. Rat liver cells — when loaded onto collagen hydrogels bearing a protein called EGF, which promotes cell growth — showed signs of DNA replication and cell division. In a separate experiment, the researchers decorated a fibrin hydrogel with patterns of a protein called Delta-1, which activates a specific pathway in cells called Notch signaling. When they introduced human bone cancer cells into the hydrogel, cells in the Delta-1-patterned regions activated Notch signaling, while cells in areas without Delta-1 did not.

    These experiments with multiple biological scaffolds and protein signals indicate that their approach could work for almost any type of protein signal and biomaterial system, DeForest said.

    “Now we can start to create hydrogel scaffolds with many different signals, utilizing our understanding of cell signaling in response to specific protein combinations to modulate critical biological function in time and space,” he added.

    With more-complex signals loaded on to hydrogels, scientists could then try to control stem cell differentiation, a key step in turning science fiction into science fact.

    The research was funded by the National Science Foundation, the National Institutes of Health and Gree Real Estate.

    See the full article here .


    Please help promote STEM in your local schools.

    Stem Education Coalition

    The University of Washington is one of the world’s preeminent public universities. Our impact on individuals, on our region, and on the world is profound — whether we are launching young people into a boundless future or confronting the grand challenges of our time through undaunted research and scholarship. Ranked number 10 in the world in Shanghai Jiao Tong University rankings and educating more than 54,000 students annually, our students and faculty work together to turn ideas into impact and in the process transform lives and our world. For more about our impact on the world, every day.
    So what defines us —the students, faculty and community members at the University of Washington? Above all, it’s our belief in possibility and our unshakable optimism. It’s a connection to others, both near and far. It’s a hunger that pushes us to tackle challenges and pursue progress. It’s the conviction that together we can create a world of good. Join us on the journey.

  • richardmitnick 12:47 pm on January 16, 2021 Permalink | Reply
    Tags: "Conductive nature in crystal structures revealed at magnification of 10 million times", Chemical engineering, , , MBE-molecular beam epitaxy, Metallic lines in a perovskite crystal, ,   

    From University of Minnesota Twin Cities: “Conductive nature in crystal structures revealed at magnification of 10 million times” 


    From University of Minnesota Twin Cities

    January 15, 2021

    Media Contacts
    Main Line
    University Public Relations
    (612) 624-5551

    Rhonda Zurn
    College of Science and Engineering, Twin Cities

    Using advanced analytical scanning transmission electron microscopy (STEM) at a magnification of 10 million times, University of Minnesota researchers were able to isolate and image the structure and composition of the metallic line defect in a perovskite crystal BaSnO3. This image shows the atomic arrangement of both the BaSnO3 crystal (on the left) and the metallic line defect.

    In groundbreaking materials research, a team led by University of Minnesota Professor K. Andre Mkhoyan has made a discovery that blends the best of two sought-after qualities for touchscreens and smart windows—transparency and conductivity.

    The researchers are the first to observe metallic lines in a perovskite crystal. Perovskites abound in the Earth’s center, and barium stannate (BaSnO3) is one such crystal. However, it has not been studied extensively for metallic properties because of the prevalence of more conductive materials on the planet like metals or semiconductors. The finding was made using advanced transmission electron microscopy (TEM), a technique that can form images with magnifications of up to 10 million.

    The research is published in Science Advances, a peer-reviewed scientific journal published by the American Association for the Advancement of Science (AAAS).

    “The conductive nature and preferential direction of these metallic line defects mean we can make a material that is transparent like glass and at the same time very nicely directionally conductive like a metal,” said Mkhoyan, a TEM expert and the Ray D. and Mary T. Johnson/Mayon Plastics Chair in the Department of Chemical Engineering and Materials Science at the University of Minnesota’s College of Science and Engineering. “This gives us the best of two worlds. We can make windows or new types of touch screens transparent and at the same time conductive. This is very exciting.”

    Defects, or imperfections, are common in crystals—and line defects (the most common among them is the dislocation) are a row of atoms that deviate from the normal order. Because dislocations have the same composition of elements as the host crystal, the changes in electronic band structure at the dislocation core, due to symmetry-reduction and strain, are often only slightly different than that of the host. The researchers needed to look outside the dislocations to find the metallic line defect, where defect composition and resulting atomic structure are vastly different.

    “We easily spotted these line defects in the high-resolution scanning transmission electron microscopy images of these BaSnO3 thin films because of their unique atomic configuration and we only saw them in the plan view,” said Hwanhui Yun, a graduate student in the Department of Chemical Engineering and Materials Science and a lead author of the study.

    For this study, BaSnO3 films were grown by molecular beam epitaxy (MBE)—a technique to fabricate high-quality crystals—in a lab at the University of Minnesota Twin Cities. Metallic line defects observed in these BaSnO3 films propagate along film growth direction, which means researchers can potentially control how or where line defects appear—and potentially engineer them as needed in touchscreens, smart windows, and other future technologies that demand a combination of transparency and conductivity.

    “We had to be creative to grow high-quality BaSnO3 thin films using MBE. It was exciting when these new line defects came into light in the microscope,” said Bharat Jalan, associate professor and Shell Chair in the Department of Chemical Engineering and Materials Science, who heads up the lab that grows a variety of perovskite oxide films by MBE.

    Perovskite crystals (ABX3) contain three elements in the unit cell. This gives it freedom for structural alterations such as composition and crystal symmetry, and the ability to host a variety of defects. Because of different coordination and bonding angles of the atoms in the line defect core, new electronic states are introduced and the electronic band structure is modified locally in such a dramatic way that it turns the line defect into metal.

    “It was fascinating how theory and experiment agreed with each other here,” said Turan Birol, assistant professor in the Department of Chemical Engineering and Materials Science and an expert in density functional theory (DFT). “We could verify the experimental observations of the atomic structure and electronic properties of this line defect with first principles DFT calculations.”

    Members of the research team include University of Minnesota Ph.D. students and postdoctoral fellows Hwanhui Yun, Mehmet Topsakal (now associate scientist at Brookhaven National Laboratory), and Abhinav Prakash (postdoc researcher Argonne National Laboratory); and University of Minnesota faculty members K. Andre Mkhoyan, Bharat Jalan, Turan Birol, and Jong Seok Jeong.

    This research was supported in part by SMART, one of seven centers of nCORE, a Semiconductor Research Corporation program, sponsored by National Institute of Standards and Technology, and by the National Science Foundation (NSF) through the University of Minnesota Materials Research Science and Engineering Center (MRSEC). The team also worked with the University of Minnesota Characterization Facility. The MBE growth work was supported partially by the NSF and the Air Force Office of Scientific Research.

    See the full article here .


    Please help promote STEM in your local schools.

    Stem Education Coalition


    The University of Minnesota, Twin Cities (often referred to as the U of M, UMN, Minnesota, or simply the U) is a public research university in Minneapolis and Saint Paul, MN. The Twin Cities campus comprises locations in Minneapolis and St. Paul approximately 3 miles (4.8 km) apart, and the St. Paul location is in neighboring Falcon Heights. The Twin Cities campus is the oldest and largest in the University of Minnesota system and has the sixth-largest main campus student body in the United States, with 51,327 students in 2019-20. It is the flagship institution of the University of Minnesota System, and is organized into 19 colleges, schools, and other major academic units.

    The University was included in a list of Public Ivy universities in 2001. Legislation passed in 1851 to develop the university, and the first college classes were held in 1867. The university is categorized as a Doctoral University – Highest Research Activity (R1) in the Carnegie Classification of Institutions of Higher Education. Minnesota is a member of the Association of American Universities and is ranked 14th in research activity, with $881 million in research and development expenditures in the fiscal year ending June 30, 2015.

    University of Minnesota faculty, alumni, and researchers have won 26 Nobel Prizes and three Pulitzer Prizes. Notable University of Minnesota alumni include two vice presidents of the United States, Hubert Humphrey and Walter Mondale.

  • richardmitnick 2:44 pm on December 1, 2020 Permalink | Reply
    Tags: "Fikile Brushett is looking for new ways to store energy", , , Chemical engineering, ,   

    From MIT: “Fikile Brushett is looking for new ways to store energy” 

    MIT News

    From MIT News

    December 1, 2020
    Anne Trafton

    Fikile Brushett, an MIT associate professor of chemical engineering, leads a group dedicated to developing more efficient ways to store energy, including batteries that could be used to store the energy generated by wind and solar power.
    Credit: Jared Charney.

    Fikile Brushett, an MIT associate professor of chemical engineering, had an unusual source of inspiration for his career in the chemical sciences: the character played by Nicolas Cage in the 1996 movie “The Rock.” In the film, Cage portrays an FBI chemist who hunts down a group of rogue U.S. soldiers who have commandeered chemical weapons and taken over the island of Alcatraz.

    “For a really long time, I really wanted to be a chemist and work for the FBI with chemical warfare agents. That was the goal: to be Nick Cage,” recalls Brushett, who first saw the movie as a high school student living in Silver Spring, Maryland, a suburb of Washington.

    Though he did not end up joining the FBI or working with chemical weapons — which he says is probably for the best — Brushett did pursue his love of chemistry. In his lab at MIT, Brushett leads a group dedicated to developing more efficient and sustainable ways to store energy, including batteries that could be used to store the electricity generated by wind and solar power. He is also exploring new ways to convert carbon dioxide to useful fuels.

    “The backbone of our global energy economy is based upon liquid fossil fuels right now, and energy demand is increasing,” he says. “The challenge we’re facing is that carbon emissions are tied very tightly to this increasing energy demand, and carbon emissions are linked to climate volatility, as well as pollution and health effects. To me, this is an incredibly urgent, important, and inspiring problem to go after.”

    “A body of knowledge”

    Brushett’s parents immigrated to the United States in the early 1980s, before he was born. His mother, an English as a second language teacher, is from South Africa, and his father, an economist, is from the United Kingdom. Brushett grew up mostly in the Washington area, with the exception of four years spent living in Zimbabwe, due to his father’s work at the World Bank.

    Brushett remembers this as an idyllic time, saying, “School ended at 1 p.m., so you almost had the whole afternoon to do sports at school, or you could go home and just play in the garden.”

    His family returned to the Washington area while he was in sixth grade, and in high school, he started to get interested in chemistry, as well as other scientific subjects and math.

    At the University of Pennsylvania, he decided to major in chemical engineering because someone had advised him that if he liked chemistry and math, chemical engineering would be a good fit. While he enjoyed some of his chemical engineering classes, he struggled with others at first.

    “I remember really having a hard time with chemE for a while, and I was fortunate enough to have a really good academic advisor who said, ‘Listen, chemE is hard for some people. Some people get it immediately, for some people it takes a little while for it to sink in,’” he says. Around his junior year, concepts started to fall into place, he recalls. “Rather than looking at courses as self-contained units, the units started coming together and flowing into a body of knowledge. I was able to see the interconnections between courses.”

    While he was originally most interested in molecular biotechnology — the field of engineering proteins and other biological molecules — he ended up working in a reaction engineering lab with his academic advisor, John Vohs. There, he studied how catalytic surfaces influence chemical reactions. At Vohs’ recommendation, he applied to the University of Illinois at Urbana-Champaign for graduate school, where he worked on electrochemistry projects. With his PhD advisor, Paul Kenis, he developed microfluidic fuel cells that could run on a variety of different fuels as portable power sources.

    During his third year of graduate school, he began applying for faculty positions and was offered a job at MIT, which he accepted but deferred for two years so he could do a postdoc at Argonne National Laboratory. There, he worked with scientists and engineers doing a wide range of research on electrochemical energy storage, and became interested in flow batteries, which is now one of the major focus areas of his lab at MIT.

    Modeling new technology

    Unlike the rechargeable lithium-ion batteries that power our cell phones and laptops, flow batteries use large tanks of liquid to store energy. Such batteries have traditionally been prohibitively expensive because they rely on pricey electroactive metal salts. Brushett is working on alternative approaches that use less expensive electroactive materials derived from organic compounds.

    Such batteries could be used to store the power intermittently produced by wind turbines and solar panels, making them a more reliable, efficient, and cost-effective source of energy. His lab also works on new processes for converting carbon dioxide, a waste product and greenhouse gas, into useful fuels.

    In a related area of research, Brushett’s lab performs “techno-economic” modeling of potential new technologies, to help them assess what aspects of the technology need the most improvement to make them economically feasible.

    “With techno-economic modeling, we can devise targets for basic science,” he says. “We’re always looking for the rate-limiting step. What is it that’s preventing us from moving forward? In some cases it could be a catalyst, in other cases it could be a membrane. In other cases it could be the architecture for the device.”

    Once those targets are identified, researchers working in those areas have a better idea of what they need to focus on to make a particular technology work, Brushett says.

    “That’s the thing I’ve been most proud of from our research — hopefully opening up or demystifying the field and allowing a more diverse set of researchers to enter and to add value, which I think is important in terms of growing the science and developing new ideas,” he says.

    See the full article here .

    Please help promote STEM in your local schools.

    Stem Education Coalition

    MIT Seal

    The mission of MIT is to advance knowledge and educate students in science, technology, and other areas of scholarship that will best serve the nation and the world in the twenty-first century. We seek to develop in each member of the MIT community the ability and passion to work wisely, creatively, and effectively for the betterment of humankind.

    USPS “Forever” postage stamps celebrating Innovation at MIT.

    MIT Campus

  • richardmitnick 11:40 am on September 29, 2020 Permalink | Reply
    Tags: "Machine learning homes in on catalyst interactions to accelerate materials development", , , Chemical engineering, , ,   

    From University of Michigan via phys.org: “Machine learning homes in on catalyst interactions to accelerate materials development” 

    U Michigan bloc

    From University of Michigan


    From phys.org

    September 29, 2020

    Credit: CC0 Public Domain

    A machine learning technique rapidly rediscovered rules governing catalysts that took humans years of difficult calculations to reveal—and even explained a deviation. The University of Michigan team that developed the technique believes other researchers will be able to use it to make faster progress in designing materials for a variety of purposes.

    “This opens a new door, not just in understanding catalysis, but also potentially for extracting knowledge about superconductors, enzymes, thermoelectrics, and photovoltaics,” said Bryan Goldsmith, an assistant professor of chemical engineering, who co-led the work with Suljo Linic, a professor of chemical engineering.

    The key to all of these materials is how their electrons behave. Researchers would like to use machine learning techniques to develop recipes for the material properties that they want. For superconductors, the electrons must move without resistance through the material. Enzymes and catalysts need to broker exchanges of electrons, enabling new medicines or cutting chemical waste, for instance. Thermoelectrics and photovoltaics absorb light and generate energetic electrons, thereby generating electricity.

    Machine learning algorithms are typically “black boxes,” meaning that they take in data and spit out a mathematical function that makes predictions based on that data.

    “Many of these models are so complicated that it’s very difficult to extract insights from them,” said Jacques Esterhuizen, a doctoral student in chemical engineering and first author of the paper in the journal Chem. “That’s a problem because we’re not only interested in predicting material properties, we also want to understand how the atomic structure and composition map to the material properties.”

    But a new breed of machine learning algorithm lets researchers see the connections that the algorithm is making, identifying which variables are most important and why. This is critical information for researchers trying to use machine learning to improve material designs, including for catalysts.

    A good catalyst is like a chemical matchmaker. It needs to be able to grab onto the reactants, or the atoms and molecules that we want to react, so that they meet. Yet, it must do so loosely enough that the reactants would rather bind with one another than stick with the catalyst.

    In this particular case, they looked at metal catalysts that have a layer of a different metal just below the surface, known as a subsurface alloy. That subsurface layer changes how the atoms in the top layer are spaced and how available the electrons are for bonding. By tweaking the spacing, and hence the electron availability, chemical engineers can strengthen or weaken the binding between the catalyst and the reactants.

    Esterhuizen started by running quantum mechanical simulations at the National Energy Research Scientific Computing Center. These formed the data set, showing how common subsurface alloy catalysts, including metals such as gold, iridium and platinum, bond with common reactants such as oxygen, hydroxide and chlorine.

    The team used the algorithm to look at eight material properties and conditions that might be important to the binding strength of these reactants. It turned out that three mattered most. The first was whether the atoms on the catalyst surface were pulled apart from one another or compressed together by the different metal beneath. The second was how many electrons were in the electron orbital responsible for bonding, the d-orbital in this case. And the third was the size of that d-electron cloud.

    The resulting predictions for how different alloys bind with different reactants mostly reflected the “d-band” model, which was developed over many years of quantum mechanical calculations and theoretical analysis. However, they also explained a deviation from that model due to strong repulsive interactions, which occurs when electron-rich reactants bind on metals with mostly filled electron orbitals.

    See the full article here .


    Please support STEM education in your local school system

    Stem Education Coalition

    U MIchigan Campus

    The University of Michigan (U-M, UM, UMich, or U of M), frequently referred to simply as Michigan, is a public research university located in Ann Arbor, Michigan, United States. Originally, founded in 1817 in Detroit as the Catholepistemiad, or University of Michigania, 20 years before the Michigan Territory officially became a state, the University of Michigan is the state’s oldest university. The university moved to Ann Arbor in 1837 onto 40 acres (16 ha) of what is now known as Central Campus. Since its establishment in Ann Arbor, the university campus has expanded to include more than 584 major buildings with a combined area of more than 34 million gross square feet (781 acres or 3.16 km²), and has two satellite campuses located in Flint and Dearborn. The University was one of the founding members of the Association of American Universities.

    Considered one of the foremost research universities in the United States,[7] the university has very high research activity and its comprehensive graduate program offers doctoral degrees in the humanities, social sciences, and STEM fields (Science, Technology, Engineering and Mathematics) as well as professional degrees in business, medicine, law, pharmacy, nursing, social work and dentistry. Michigan’s body of living alumni (as of 2012) comprises more than 500,000. Besides academic life, Michigan’s athletic teams compete in Division I of the NCAA and are collectively known as the Wolverines. They are members of the Big Ten Conference.

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