Tagged: Chemistry Toggle Comment Threads | Keyboard Shortcuts

  • richardmitnick 10:06 am on January 10, 2020 Permalink | Reply
    Tags: , Chemistry, Julia Ortony, , , Self-assembling nanostructures,   

    From MIT News: Women in STEM- “Julia Ortony: Concocting nanomaterials for energy and environmental applications” 

    MIT News

    From MIT News

    January 9, 2020
    Leda Zimmerman | MIT Energy Initiative

    1
    Julia Ortony is the Finmeccanica Career Development Assistant Professor of Engineering in the Department of Materials Science and Engineering. Photo: Lillie Paquette/School of Engineering

    2
    Assistant Professor Julia Ortony (right) and graduate student William Lindemann discuss his experiments on self-assembling nanofibers. Work at the Ortony lab focuses on molecular design and synthesis to create new soft nanomaterials for tackling problems related to energy and the environment. Photo: Lillie Paquette/School of Engineering

    The MIT assistant professor is entranced by the beauty she finds pursuing chemistry.

    A molecular engineer, Julia Ortony performs a contemporary version of alchemy.

    “I take powder made up of disorganized, tiny molecules, and after mixing it up with water, the material in the solution zips itself up into threads 5 nanometers thick — about 100 times smaller than the wavelength of visible light,” says Ortony, the Finmeccanica Career Development Assistant Professor of Engineering in the Department of Materials Science and Engineering (DMSE). “Every time we make one of these nanofibers, I am amazed to see it.”

    But for Ortony, the fascination doesn’t simply concern the way these novel structures self-assemble, a product of the interaction between a powder’s molecular geometry and water. She is plumbing the potential of these nanomaterials for use in renewable energy and environmental remediation technologies, including promising new approaches to water purification and the photocatalytic production of fuel.

    Tuning molecular properties

    Ortony’s current research agenda emerged from a decade of work into the behavior of a class of carbon-based molecular materials that can range from liquid to solid.

    During doctoral work at the University of California at Santa Barbara, she used magnetic resonance (MR) spectroscopy to make spatially precise measurements of atomic movement within molecules, and of the interactions between molecules. At Northwestern University, where she was a postdoc, Ortony focused this tool on self-assembling nanomaterials that were biologically based, in research aimed at potential biomedical applications such as cell scaffolding and regenerative medicine.

    “With MR spectroscopy, I investigated how atoms move and jiggle within an assembled nanostructure,” she says. Her research revealed that the surface of the nanofiber acted like a viscous liquid, but as one probed further inward, it behaved like a solid. Through molecular design, it became possible to tune the speed at which molecules that make up a nanofiber move.

    A door had opened for Ortony. “We can now use state-of-matter as a knob to tune nanofiber properties,” she says. “For the first time, we can design self-assembling nanostructures, using slow or fast internal molecular dynamics to determine their key behaviors.”

    Slowing down the dance

    When she arrived at MIT in 2015, Ortony was determined to tame and train molecules for nonbiological applications of self-assembling “soft” materials.

    “Self-assembling molecules tend to be very dynamic, where they dance around each other, jiggling all the time and coming and going from their assembly,” she explains. “But we noticed that when molecules stick strongly to each other, their dynamics get slow, and their behavior is quite tunable.” The challenge, though, was to synthesize nanostructures in nonbiological molecules that could achieve these strong interactions.

    “My hypothesis coming to MIT was that if we could tune the dynamics of small molecules in water and really slow them down, we should be able to make self-assembled nanofibers that behave like a solid and are viable outside of water,” says Ortony.

    Her efforts to understand and control such materials are now starting to pay off.

    “We’ve developed unique, molecular nanostructures that self-assemble, are stable in both water and air, and — since they’re so tiny — have extremely high surface areas,” she says. Since the nanostructure surface is where chemical interactions with other substances take place, Ortony has leapt to exploit this feature of her creations — focusing in particular on their potential in environmental and energy applications.

    Clean water and fuel from sunlight

    One key venture, supported by Ortony’s Professor Amar G. Bose Fellowship, involves water purification. The problem of toxin-laden drinking water affects tens of millions of people in underdeveloped nations. Ortony’s research group is developing nanofibers that can grab deadly metals such as arsenic out of such water. The chemical groups she attaches to nanofibers are strong, stable in air, and in recent tests “remove all arsenic down to low, nearly undetectable levels,” says Ortony.

    She believes an inexpensive textile made from nanofibers would be a welcome alternative to the large, expensive filtration systems currently deployed in places like Bangladesh, where arsenic-tainted water poses dire threats to large populations.

    “Moving forward, we would like to chelate arsenic, lead, or any environmental contaminant from water using a solid textile fabric made from these fibers,” she says.

    In another research thrust, Ortony says, “My dream is to make chemical fuels from solar energy.” Her lab is designing nanostructures with molecules that act as antennas for sunlight. These structures, exposed to and energized by light, interact with a catalyst in water to reduce carbon dioxide to different gases that could be captured for use as fuel.

    In recent studies, the Ortony lab found that it is possible to design these catalytic nanostructure systems to be stable in water under ultraviolet irradiation for long periods of time. “We tuned our nanomaterial so that it did not break down, which is essential for a photocatalytic system,” says Ortony.

    Students dive in

    While Ortony’s technologies are still in the earliest stages, her approach to problems of energy and the environment are already drawing student enthusiasts.

    Dae-Yoon Kim, a postdoc in the Ortony lab, won the 2018 Glenn H. Brown Prize from the International Liquid Crystal Society for his work on synthesized photo-responsive materials and started a tenure track position at the Korea Institute of Science and Technology this fall. Ortony also mentors Ty Christoff-Tempesta, a DMSE doctoral candidate, who was recently awarded a Martin Fellowship for Sustainability. Christoff-Tempesta hopes to design nanoscale fibers that assemble and disassemble in water to create environmentally sustainable materials. And Cynthia Lo ’18 won a best-senior-thesis award for work with Ortony on nanostructures that interact with light and self-assemble in water, work that will soon be published. She is “my superstar MIT Energy Initiative UROP [undergraduate researcher],” says Ortony.

    Ortony hopes to share her sense of wonder about materials science not just with students in her group, but also with those in her classes. “When I was an undergraduate, I was blown away at the sheer ability to make a molecule and confirm its structure,” she says. With her new lab-based course for grad students — 3.65 (Soft Matter Characterization) — Ortony says she can teach about “all the interests that drive my research.”

    While she is passionate about using her discoveries to solve critical problems, she remains entranced by the beauty she finds pursuing chemistry. Fascinated by science starting in childhood, Ortony says she sought out every available class in chemistry, “learning everything from beginning to end, and discovering that I loved organic and physical chemistry, and molecules in general.”

    Today, she says, she finds joy working with her “creative, resourceful, and motivated” students. She celebrates with them “when experiments confirm hypotheses, and it’s a breakthrough and it’s thrilling,” and reassures them “when they come with a problem, and I can let them know it will be thrilling soon.”

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings
    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.

    MIT Campus

     
  • richardmitnick 9:59 am on January 3, 2020 Permalink | Reply
    Tags: "A close look at thin ice", , Chemistry, , Two-dimensional ice,   

    From Penn Today: “A close look at thin ice” 


    From Penn Today

    January 1, 2020
    Katherine Unger Baillie

    On frigid days, water vapor in the air can transform directly into solid ice, depositing a thin layer on surfaces such as a windowpane or car windshield. Though commonplace, this process is one that has kept physicists and chemists busy figuring out the details for decades.

    1
    An international team of scientists, including atmospheric chemists from Penn, describe the first-ever visualization of the atomic structure of two-dimensional ice as it formed. (Image: Courtesy of Joseph Francisco)

    In a new Nature paper, an international team of scientists describe the first-ever visualization of the atomic structure of two-dimensional ice as it formed. Insights from the findings, which were driven by computer simulations that inspired experimental work, may one day inform the design of materials that make ice removal a simpler and less costly process.

    “One of the things that I find very exciting is that this challenges the traditional view of how ice grows,” says Joseph S. Francisco, an atmospheric chemist at the University of Pennsylvania and an author on the paper.

    “Knowing the structure is very important,” adds coauthor Chongqin Zhu, a postdoctoral fellow in Francisco’s group who led much of the computational work for the study. “Low-dimensional water is ubiquitous in nature and plays a critical role in an incredibly broad spectrum of sciences, including materials science, chemistry, biology, and atmospheric science.

    “It also has practical significance. For example, removing ice is critical when it comes to things like wind turbines, which cannot function when they are covered in ice. If we understand the interaction between water and surfaces, then we might be able to develop new materials to make this ice removal easier.”

    In recent years, Francisco’s lab has devoted considerable attention to studying the behavior of water, and specifically ice, at the interface of solid surfaces. What they’ve learned about ice’s growth mechanisms and structures in this context helps them understand how ice behaves in more complex scenarios, like when interacting with other chemicals and water vapor in the atmosphere.

    “We’re interested in the chemistry of ice at the transition with the gas phase, as that’s relevant to the reactions that are happening in our atmosphere,” Francisco explains.

    To understand basic principles of ice growth, researchers have entered this area of study by investigating two-dimensional structures: layers of ice that are only several water molecules thick.

    In previous studies of two-dimensional ice [PNAS], using computational methods and simulations, Francisco, Zhu, and colleagues showed that ice grows differently depending on whether a surface repels or attracts water, and the structure of that surface.

    In the current work, they sought real-world verification of their simulations, reaching out to a team at Peking University to see if they could obtain images of two-dimensional ice.

    The Peking team employed super-powerful atomic force microscopy, which uses a mechanical probe to “feel” the material being studied, translating the feedback into nanoscale-resolution images. Atomic force microscopy is capable of capturing structural information with a minimum of disruption to the material itself, allowing the scientists to identify even unstable intermediate structures that arise during the process of ice formation.

    Virtually all naturally occurring ice on Earth is known as hexagonal ice for its six-sided structure. This is why snowflakes all have six-fold symmetry. One plane of hexagonal ice has a similar structure to that of two-dimensional ice and can terminate in two types of edges—“zigzag” or “armchair.” Usually this plane of natural ice terminates with a zigzag edge.

    However, when ice is grown in two dimensions, researchers find that the pattern of growth is different. The current work, for the first time, shows that the armchair edges can be stabilized and that their growth follows a novel reaction pathway.

    “This is a totally different mechanism from what was known,” Zhu says.

    Although the zigzag growth patterns were previously believed to only have six-membered rings of water molecules, both Zhu’s calculations and the atomic force microscopy revealed an intermediate stage where five-membered rings were present.

    This result, the researchers say, may help explain the experimental observations reported in their 2017 PNAS paper, which found that ice could grow in two different ways on a surface, depending on the properties of that surface.

    In addition to lending insight into future design of materials conducive to ice removal, the techniques used in the work are also applicable to probe the growth of a large family of two-dimensional materials beyond two-dimensional ices, thus opening a new avenue of visualizing the structure and dynamics of low-dimensional matter.

    For chemist Jeffrey Saven, a professor in Penn Arts & Sciences who was not directly involved in the current work, the collaboration between the theorists in Francisco’s group and their colleagues in China called to mind a parable he learned from a mentor during his training.

    “An experimentalist is talking with theorists about data collected in the lab. The mediocre theorist says, ‘I can’t really explain your data.’ The good theorist says, ‘I have a theory that fits your data.’ The great theorist says, ‘That’s interesting, but here is the experiment you should be doing and why.’”

    To build on this successful partnership, Zhu, Francisco, and their colleagues are embarking on theoretical and experimental work to begin to fill in the gaps related to how two-dimensional ice builds into three dimensions.

    “The two-dimensional work is fundamental to laying the background,” says Francisco. “And having the calculations verified by experiments is so good, because that allows us to go back to the calculations and take the next bold step toward three dimensions.”

    “Looking for features of three-dimensional ice will be the next step,” Zhu says, “and should be very important in looking for applications of this work.”

    Joseph S. Francisco is President’s Distinguished Professor in the Department of Earth and Environmental Science, with a secondary appointment in the Department of Chemistry in the University of Pennsylvania School of Arts and Sciences.

    Chongqin Zhu is a postdoctoral fellow in the Department of Earth and Environmental Science in the University of Pennsylvania’s School of Arts and Sciences.

    Francisco and Zhu’s coauthors on the study were Peking University’s Runze Ma, Duanyun Cao, Ye Tian, Jinbo Peng, Jing Guo, Ji Chen, Xin-Zheng Li, Li-Mei Xu, En-Ge Wang, and Ying Jiang; and the University of Nebraska-Lincoln’s Xiao Cheng Zeng.

    The study was supported by the National Key R&D Program (grants 2016YFA0300901, 2017YFA0205003, and 2015CB856801), National Natural Science Foundation of China (grants 11888101, 11634001, 21725302, and 11525520), Strategic Priority Research Program of the Chinese Academy of Science (Grant XDB28000000), Beijing Municipal Science & Technology Commission, and U.S. National Science Foundation (Grant 1665324).

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    U Penn campus

    Academic life at Penn is unparalleled, w
    ith 100 countries and every U.S. state represented in one of the Ivy League’s most diverse student bodies. Consistently ranked among the top 10 universities in the country, Penn enrolls 10,000 undergraduate students and welcomes an additional 10,000 students to our world-renowned graduate and professional schools.

    Penn’s award-winning educators and scholars encourage students to pursue inquiry and discovery, follow their passions, and address the world’s most challenging problems through an interdisciplinary approach.

     
  • richardmitnick 8:32 am on January 3, 2020 Permalink | Reply
    Tags: "Life could have emerged from lakes with high phosphorus", , , Chemistry, ,   

    From University of Washington: “Life could have emerged from lakes with high phosphorus” 

    U Washington

    From University of Washington

    December 30, 2019
    Hannah Hickey

    1
    Eastern California’s Mono Lake has no outflow, allowing salts to build up over time. The high salts in this carbonate-rich lake can grow into pillars. Matthew Dillon/Flickr

    Life as we know it requires phosphorus. It’s one of the six main chemical elements of life, it forms the backbone of DNA and RNA molecules, acts as the main currency for energy in all cells and anchors the lipids that separate cells from their surrounding environment.

    But how did a lifeless environment on the early Earth supply this key ingredient?

    “For 50 years, what’s called ‘the phosphate problem,’ has plagued studies on the origin of life,” said first author Jonathan Toner, a University of Washington research assistant professor of Earth and space sciences.

    The problem is that chemical reactions that make the building blocks of living things need a lot of phosphorus, but phosphorus is scarce. A new UW study, published Dec. 30 in the Proceedings of the National Academy of Sciences, finds an answer to this problem in certain types of lakes.

    The study focuses on carbonate-rich lakes, which form in dry environments within depressions that funnel water draining from the surrounding landscape. Because of high evaporation rates, the lake waters concentrate into salty and alkaline, or high-pH, solutions. Such lakes, also known as alkaline or soda lakes, are found on all seven continents.

    The researchers first looked at phosphorus measurements in existing carbonate-rich lakes, including Mono Lake in California, Lake Magadi in Kenya and Lonar Lake in India.

    While the exact concentration depends on where the samples were taken and during what season, the researchers found that carbonate-rich lakes have up to 50,000 times phosphorus levels found in seawater, rivers and other types of lakes. Such high concentrations point to the existence of some common, natural mechanism that accumulates phosphorus in these lakes.

    Today these carbonate-rich lakes are biologically rich and support life ranging from microbes to Lake Magadi’s famous flocks of flamingoes. These living things affect the lake chemistry. So researchers did lab experiments with bottles of carbonate-rich water at different chemical compositions to understand how the lakes accumulate phosphorus, and how high phosphorus concentrations could get in a lifeless environment.

    The reason these waters have high phosphorus is their carbonate content. In most lakes, calcium, which is much more abundant on Earth, binds to phosphorus to make solid calcium phosphate minerals, which life can’t access. But in carbonate-rich waters, the carbonate outcompetes phosphate to bind with calcium, leaving some of the phosphate unattached. Lab tests that combined ingredients at different concentrations show that calcium binds to carbonate and leaves the phosphate freely available in the water.

    “It’s a straightforward idea, which is its appeal,” Toner said. “It solves the phosphate problem in an elegant and plausible way.”

    Phosphate levels could climb even higher, to a million times levels in seawater, when lake waters evaporate during dry seasons, along shorelines, or in pools separated from the main body of the lake.

    “The extremely high phosphate levels in these lakes and ponds would have driven reactions that put phosphorus into the molecular building blocks of RNA, proteins, and fats, all of which were needed to get life going,” said co-author David Catling, a UW professor of Earth & space sciences.

    2
    Colored dots show the level of phosphorus measured in different carbonate-rich lakes around the world. Existing carbonate-rich lakes can contain up to 50,000 times the levels of phosphate found in seawater, with the highest levels measured in British Columbia’s Goodenough and Last Chance lake system (yellow dots).Toner et al/PNAS

    The carbon dioxide-rich air on the early Earth, some four billion years ago, would have been ideal for creating such lakes and allowing them to reach maximum levels of phosphorus. Carbonate-rich lakes tend to form in atmospheres with high carbon dioxide. Plus, carbon dioxide dissolves in water to create acid conditions that efficiently release phosphorus from rocks.

    “The early Earth was a volcanically active place, so you would have had lots of fresh volcanic rock reacting with carbon dioxide and supplying carbonate and phosphorus to lakes,” Toner said. “The early Earth could have hosted many carbonate-rich lakes, which would have had high enough phosphorus concentrations to get life started.”

    Another recent study by the two authors showed that these types of lakes can also provide abundant cyanide to support the formation of amino acids and nucleotides, the building blocks of proteins, DNA and RNA. Before then researchers had struggled to find a natural environment with enough cyanide to support an origin of life. Cyanide is poisonous to humans, but not to primitive microbes, and is critical for the kind of chemistry that readily makes the building blocks of life.

    The research was funded by the Simons Foundation’s Collaboration on the Origins of Life.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    u-washington-campus
    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 8:31 am on January 2, 2020 Permalink | Reply
    Tags: "The long history of David Rittenhouse Lab", , Chemistry, Maths, ,   

    From Penn Today: “Space, time, and laboratories- The long history of David Rittenhouse Lab” 


    From Penn Today

    December 24, 2019

    David Brainard
    Susan Ahlborn

    Penn alums who return to campus often marvel at its transformation. Renovation projects have rejuvenated buildings like Fisher-Bennett Hall, the home of the English department and the Cinema Studies Program and one of the main teaching spaces on campus. The Perelman Center for Political Science and Economics, which opened last year, is a major hub for the social sciences. And the construction of the Carolyn Lynch Laboratory and the Stephen A. Levin Building have advanced the life sciences. Of the 26 buildings that house the people, programs and departments that make up Penn Arts & Sciences, nine are either less than 15 years old or have undergone major renovations in that time.

    1
    The original wing is a red brick structure that is adjacent to Shoemaker Green next to the Palestra. The 1967 addition is in a more modern style, and faces Walnut Street. DRL is home to the Department of Mathematics, the Department of Physics and Astronomy, the Mathematics, Physics and Astronomy Library and the Multi-Media and Educational Technology Services Center. The High Bay Lab was added in 2012. The building is named after David Rittenhouse (1731-1796), who was professor of astronomy at Penn, the first director of the United States Mint, and president of the American Philosophical Society.

    2

    One place that has remained the same in the midst of all this change is the 65-year-old David Rittenhouse Laboratory (DRL). Since 1954, the Math department, along with Physics and Astronomy, has been housed here, at the southeast corner of 33rd and Walnut Streets. Built in two phases, DRL takes up 243,002 square feet and stretches for a city block. It contains the offices and labs of 86 standing faculty, as well as grad students and post-doctoral fellows, and it provides 20 classrooms used by departments across the School.

    While the building itself might resemble a 1950s high school, the departments in it have a history of groundbreaking contributions to their fields. But a building with history is also a building that was not designed for today’s science. DRL is the legacy of an era when government partnered closely with higher education and invested heavily in facilities.

    Today, the National Science Foundation, the Department of Defense, foundations, and industry continue to fund individual research studies, and in some cases major scientific equipment. But government support for buildings themselves is now greatly reduced, and universities must find other ways to provide the modern facilities that can attract talented faculty and the graduate students that are the lifeblood of a good science department, to make possible cutting-edge research, and to facilitate excellence in teaching in the sciences.

    “Penn had really built nothing since the Depression set in,” says history of art’s David Brownlee, coauthor of “Building America’s First University: An Historical and Architectural Guide to the University of Pennsylvania.” “The DRL showed a reinvestment in West Philadelphia and an engagement with the new scientific mandates of the late 20th century. And it’s our first building that really looks like a modern building.”

    __________________________________________________________

    A Building in Two Parts
    1954 building

    James R. Edmonds, Jr., AR’12, Architect

    “Penn had really built nothing since the Depression set in,” says History of Art’s David Brownlee, coauthor of Building America’s First University: An Historical and Architectural Guide to the University of Pennsylvania. “The DRL showed a reinvestment in West Philadelphia and an engagement with the new scientific mandates of the late 20th century. And it’s our first building that really looks like a modern building.”
    1967 addition

    J. Roy Carroll, AR’26, GAR’28, Architect

    “It was in the spirit of what was being called the Philadelphia School. It’s a building for science that looks picturesque, not rational and regular and repetitive,” says Brownlee.

    3
    University Archives

    4
    David Rittenhouse

    65 Years of DRL

    1954
    The new physics and mathematics building opens. It’s named after David Rittenhouse, an inventor, astronomer, professor, and surveyor, second in awesomeness only to his friend Ben Franklin. An addition is completed in 1967.

    1957
    Physics and Astronomy gets funding from the Atomic Energy Commission to construct an accelerator with Princeton.

    USSR launches Sputnik I.

    1960
    In Physics and Astronomy, Eli Burstein helps lead the creation of Penn’s interdisciplinary Laboratory for Research on the Structure of Matter. The center has been continuously funded and is currently led by Arjun Yodh.

    1963
    Math’s Murray Gerstenhaber discovers an algebraic structure that will be named for him.

    1966
    Star Trek premieres.

    1969
    Humans land on the moon.

    5

    1972
    Physics and Astronomy’s John Robert Schrieffer shares the Nobel Prize in Physics for developing the first successful quantum theory of superconductivity.

    1973
    The first public-key cryptosystem is used for secure data transmission.

    1977
    Voyager I and II launch.

    NASA/Voyager 1

    NASA/Voyager 2

    1980
    Richard Feynman proposes quantum computing.

    Richard Feynman © Open University

    1982
    Math’s Eugenio Calabi is inducted into the National Academy of Sciences for accomplishments including the development of the Calabi conjecture, which led to Calabi-Yau manifolds.
    Physics and Astronomy’s Paul Steinhardt and his student Andreas Albrecht formulate the first viable inflationary theory of the universe.

    1985
    Math’s Peter Freyd and his student David Yetter are co-discoverers of the HOMFLY polynomial, a knot invariant in the mathematical field of knot theory.

    1988
    The Math department hosts first major U.S.-U.S.S.R. mathematics conference in modern times.

    Stephen Hawking publishes A Brief History of Time.

    Stephen Hawking

    6

    1993
    Magic: The Gathering, the first trading-card game, debuts and sells out. It’s created by Math’s Richard Garfield, C’85, GR’93, a student of Herbert Wilf.

    1994
    Math’s David Harbater coauthors a proof of Abhyankar’s conjecture, for which he shares the Cole Prize from the American Mathematical Society.

    1995
    Tom Lubensky of Physics and Astronomy coauthors Principles of Condensed Matter Physics, an influential textbook which defines the field of soft condensed matter physics.
    7

    1998
    Math’s Herbert Wilf receives the Steele Prize of the American Mathematical Society for Lifetime Achievement.

    1999
    Math’s Richard Kadison receives the Steele Prize of the American Mathematical Society for Lifetime Achievement.

    2000
    Former Professor of Physics and Astronomy Alan Heeger shares the Nobel Prize in Chemistry for work done at Penn on conductive polymers with Chemistry Professor Alan MacDiarmid and fellow Hideki Shirakawa.

    While filming A Beautiful Mind, Russell Crowe attends a Math Rademacher Lecture in DRL. No one notices.

    2002
    In Physics and Astronomy, Raymond Davis shares the Nobel Prize in Physics for detecting cosmic neutrinos.

    2004
    Physics and Astronomy’s Philip Nelson publishes his textbook Biological Physics, now a resource for biophysics curricula worldwide.

    2005
    Ron Donagi of Math coauthors a breakthrough paper on producing a Heterotic Standard Model.

    2008
    The Math department creates the Applied Mathematics and Computational Science Program.

    2009
    Following the arrival of Mark Trodden and Justin Khoury, Physics and Astronomy establishes the Center for Particle Cosmology to address questions about the universe and fundamental theories of matter and energy.

    6

    2010
    Using modern techniques, Math’s Philip Gressman and Robert Strain solve the 140-year-old Boltzmann equation.
    NASA confirms the presence of large quantities of water ice on the north pole of the Moon.

    2011
    Andrea Liu of Physics and Astronomy identifies defects that mediate flow in solids ranging from crystalline to completely disordered, enabling microscopic understanding of how solids deform and ultimately break if pushed too far.

    2012

    Voyager I enters interstellar space.

    Math’s Antonella Grassi develops a program to study elliptic fibrations with Julius Shaneson. Their findings inspire a completely new formulation of F-theory in physics.
    7
    Math’s Antonella Grassi

    2014
    In Math, Florian Pop helps to prove the full Oort Conjecture on cyclic covers, while Ted Chinburg and David Harbater advance knowledge on the non-cyclic group.

    2015
    Math’s Tony Pantev and Ron Donagi are selected to lead the Simons Collaboration for Homological Mirror Symmetry (HMS), a group exploring HMS and its applications.

    2016
    Math’s Charles Epstein receives the Bergman Prize of the American Mathematical Society for fundamental contributions including his research on a relative index on the space of embeddable Cauchy-Riemann structures.

    Physics and Astronomy’s Eugene Beier and Joshua Klein are part of the SNO collaboration that shares in a Breakthrough Prize for their work on neutrino oscillations.
    12

    SNOLAB, Sudbury, Ontario, Canada.

    2018
    Math’s Robert Ghrist begins publishing Calculus BLUE, 25 hours of free animated video lectures for multivariable calculus. He and his team, in partnership with Honeywell Intl., also develop powerful new methods arising from algebraic topology.

    13
    Math’s Robert Ghrist

    Hidden Figures hits theaters.

    Physics and Astronomy’s Mark Devlin and his group begin work on an 8,000-pound large aperture telescope receiver destined for the Simons Observatory in the Atacama Desert.

    LBL The Simons Array in the Atacama in Chile, with the 6 meter Atacama Cosmology Telescope

    2019
    Scientific American covers research led by Physics and Astronomy’s Mirjam Cvetic that finds a “quadrillion” string theory solutions.

    Physics and Astronomy’s Charles Kane and Eugene Mele receive the Breakthrough Prize for their work on topological insulators, which conduct electricity only on their surfaces.

    Six years of observation of distant galaxies for the Dark Energy Survey ends, beginning world-leading cosmological analyses by Bhuvnesh Jain, Masao Sako, Gary Bernstein, and others in Physics and Astronomy.

    Dark Energy Survey


    Dark Energy Camera [DECam], built at FNAL


    NOAO/CTIO Victor M Blanco 4m Telescope which houses the DECam at Cerro Tololo, Chile, housing DECam at an altitude of 7200 feet

    Timeline of the Inflationary Universe WMAP

    The Dark Energy Survey (DES) is an international, collaborative effort to map hundreds of millions of galaxies, detect thousands of supernovae, and find patterns of cosmic structure that will reveal the nature of the mysterious dark energy that is accelerating the expansion of our Universe. DES began searching the Southern skies on August 31, 2013.

    According to Einstein’s theory of General Relativity, gravity should lead to a slowing of the cosmic expansion. Yet, in 1998, two teams of astronomers studying distant supernovae made the remarkable discovery that the expansion of the universe is speeding up. To explain cosmic acceleration, cosmologists are faced with two possibilities: either 70% of the universe exists in an exotic form, now called dark energy, that exhibits a gravitational force opposite to the attractive gravity of ordinary matter, or General Relativity must be replaced by a new theory of gravity on cosmic scales.

    DES is designed to probe the origin of the accelerating universe and help uncover the nature of dark energy by measuring the 14-billion-year history of cosmic expansion with high precision. More than 400 scientists from over 25 institutions in the United States, Spain, the United Kingdom, Brazil, Germany, Switzerland, and Australia are working on the project. The collaboration built and is using an extremely sensitive 570-Megapixel digital camera, DECam, mounted on the Blanco 4-meter telescope at Cerro Tololo Inter-American Observatory, high in the Chilean Andes, to carry out the project.

    Over six years (2013-2019), the DES collaboration used 758 nights of observation to carry out a deep, wide-area survey to record information from 300 million galaxies that are billions of light-years from Earth. The survey imaged 5000 square degrees of the southern sky in five optical filters to obtain detailed information about each galaxy. A fraction of the survey time is used to observe smaller patches of sky roughly once a week to discover and study thousands of supernovae and other astrophysical transients.

    We see a picture of a black hole. Everyone says, “Wow.”

    The first image of a black hole. This is the supermassive black hole at the center of the galaxy Messier 87. Image via JPL/ Event Horizon Telescope Collaboration.

    EHT map

    Katie Bouman-Harvard Smithsonian Astrophysical Observatory. Headed to Caltech.

    Katie Bouman of Harvard Smithsonian Observatory for Astrophysics, headed to Caltech, with EHT hard drives from Messier 87

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    U Penn campus

    Academic life at Penn is unparalleled, with 100 countries and every U.S. state represented in one of the Ivy League’s most diverse student bodies. Consistently ranked among the top 10 universities in the country, Penn enrolls 10,000 undergraduate students and welcomes an additional 10,000 students to our world-renowned graduate and professional schools.

    Penn’s award-winning educators and scholars encourage students to pursue inquiry and discovery, follow their passions, and address the world’s most challenging problems through an interdisciplinary approach.

     
  • richardmitnick 6:42 am on December 23, 2019 Permalink | Reply
    Tags: , Chemistry, , The lowest temperature chemical reactions of any currently available technology.   

    From Harvard Gazette: “Catching lightning in a bottle” 

    Harvard University


    From Harvard Gazette

    December 20, 2019
    Caitlin McDermott-Murphy

    Researchers in an ultracold environment get a first look at exactly what happens during a chemical reaction.

    1
    Assistant Professor Kang-Kuen Ni and Ming-Guang Hu (not pictured), a postdoctoral scholar in the Ni lab, performed the coldest reaction in the known universe. Photos by Kris Snibbe/Harvard Staff Photographer

    Call it a serendipity dividend. A big one.

    Kang-Kuen Ni set out to do something that had never been done before. The Morris Kahn Associate Professor of Chemistry and Chemical Biology and of Physics and a pioneer of ultracold chemistry had built a new apparatus that could achieve the lowest temperature chemical reactions of any currently available technology. Then she and her team successfully forced two ultracold molecules to meet and react, breaking and forming the coldest bonds in the history of molecular couplings.

    While they were doing that, something totally unanticipated and important also happened.

    In such intense cold — 500 nanokelvin, or just a few millionths of a degree above absolute zero — the molecules slowed to such sluggish speeds that Ni and her team saw something no one has ever seen before: the moment when two molecules meet to form two new molecules. In essence, they captured a chemical reaction in its most critical and elusive act.

    “Because [the molecules] are so cold,” Ni said, “now we kind of have a bottleneck effect.”

    Chemical reactions are responsible for literally everything: from making soap, pharmaceuticals, and energy to cooking, digesting, and breathing. Understanding how they work at a fundamental level could help researchers design reactions the world has never seen. Maybe, for example, novel molecular couplings could enable more-efficient energy production, new materials like mold-proof walls, or even better building blocks for quantum computers. The world offers an almost infinite number of potential combinations to test.

    And Ni’s lab appears to have a head start on the enabling technology.

    “Probably in the next couple of years, we are the only lab that can do this,” said Ming-Guang Hu, a postdoctoral scholar in the Ni lab and first author on their paper published this month in Science.

    2
    It took the team five years to construct the apparatus capable of achieving this feat.

    It all began five years ago when Ni set out to build her new apparatus. She wasn’t sure what it would yield, but thought it might tell them something new about atoms, molecules, and chemical reactions. And that wasn’t the only uncertainty:She couldn’t be sure her intricate engineering with what superficially appears to be a chaotic mass of lasers would work.

    In her previous work, Ni used colder and colder temperatures to forge molecules from atoms that would otherwise never react. Cooled to such extremes, atoms and molecules slow to a quantum crawl, their lowest possible energy state. There, Ni can manipulate molecular interactions with utmost precision. But even she could only see the start of her reactions: Two molecules go in, but then what? What happened in the middle and the end was a black hole only theories could try to explain.

    Chemical reactions occur in just a thousandth of a billionth of a second, better known in the scientific world as a picosecond. In the last 20 years, scientists have used ultra-fast lasers like fast-action cameras, snapping rapid images of reactions as they occur. But they can’t capture the whole picture. “Most of the time,” Ni said, “you just see that the reactants disappear and the products appear in a time that you can measure. There was no direct measurement of what actually happened in the middle.” Until now.

    Ni’s ultracold temperatures force reactions to a comparatively numbed speed. When she and her team reacted two potassium rubidium molecules — chosen for their pliability —the ultracold temperatures forced the molecules to linger in the intermediate stage for mere millionths of a second. So-called microseconds may seem short, but that’s millions of times longer than ever achieved, and enough time for Ni and her team to investigate the phase when bonds break and form — in essence, how one molecule turns into another.

    With this intimate vision, Ni said she and her team can test theories that predict what happens in a reaction’s black hole and confirm if they got it right. Then, she can craft new theories, using actual data to more precisely predict what happens during other chemical reactions, even those that take place in the mysterious quantum realm.

    Already, the team is exploring what else they can learn in their ultracold test bed. Next, for example, they could manipulate the reactants, exciting them before they react to see how their heightened energy impacts the outcome. Or they could even influence the reaction as it occurs, nudging one molecule or the other. “With our controllability, this time window is long enough, we can probe,” Hu said. “Now, with this apparatus, we can think about this. Without this technique, without this paper, we cannot even think about this.”

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Harvard University campus
    Harvard University is the oldest institution of higher education in the United States, established in 1636 by vote of the Great and General Court of the Massachusetts Bay Colony. It was named after the College’s first benefactor, the young minister John Harvard of Charlestown, who upon his death in 1638 left his library and half his estate to the institution. A statue of John Harvard stands today in front of University Hall in Harvard Yard, and is perhaps the University’s best known landmark.

    Harvard University has 12 degree-granting Schools in addition to the Radcliffe Institute for Advanced Study. The University has grown from nine students with a single master to an enrollment of more than 20,000 degree candidates including undergraduate, graduate, and professional students. There are more than 360,000 living alumni in the U.S. and over 190 other countries.

     
  • richardmitnick 12:10 pm on December 18, 2019 Permalink | Reply
    Tags: "Oxford researchers move one step further towards understanding how life evolved", , , Chemistry, ,   

    From University of Oxford: “Oxford researchers move one step further towards understanding how life evolved” 

    U Oxford bloc

    From University of Oxford

    16 December 2019
    Ruth Abrahams
    ruth.abrahams@admin.ox.ac.uk
    +44 (0)1865 280730.

    A fundamental problem for biology is explaining how life evolved. How did we get from simple chemical reactions in the prebiotic soup, to animals and plants?

    A key step in explaining life is that about 4 billion years ago, all we had was just the simplest molecules that could replicate themselves. These are called ‘replicators’ – the earliest form of life, so simple that that they are almost chemistry rather than biology. Somehow they joined together to cooperate to form more complex things. This was the basis of the genome that builds us today.

    But why did they join together? Why did they cooperate? Any cooperation could be easily exploited by ‘cheating’ replicators that didn’t cooperate. Did it require special environmental conditions?

    Today, researchers from the Department of Zoology at the University of Oxford show, in Nature Ecology & Evolution, that replicators could have solved this problem themselves. If some replicators were a bit cooperative, and some were a bit ‘sticky’ then this would lead to clumps of cooperating replicators that would evolve to become more and more cooperative, eventually producing simple genomes, and then eventually, all of life that we see around us today.

    Lead researcher, Samuel Levin, at the Department of Zoology, Oxford, said: ‘As humans, we care about how things start. Our results help to solve some of that puzzle and are also relevant for trying to figure out how common we might expect complex life in the universe to be: how easy are these early steps?

    ‘I was surprised by the jump in cooperation you get when you allow coevolution — it was higher than I expected. There seems to be some sort of cyclical feedback.’

    Co-author, Professor Stuart West, at the Department of Zoology, Oxford, said: ‘Our results show us that the same issues that we think about today, with humans (cooperating and cheating) can help explain how life evolved. Life evolved as societies of cooperating replicators / molecules.’

    Authors tested their hypothesis using mathematical models. They wrote equations which distilled down evolution in early life, and then added stickiness and cooperation to see what happened. They showed, mathematically, that more complex life could evolve only when stickiness and cooperation were allowed to coevolve at the same time.

    See the full article here.


    five-ways-keep-your-child-safe-school-shootings
    Please help promote STEM in your local schools.

    Stem Education Coalition

    U Oxford campus

    Oxford is a collegiate university, consisting of the central University and colleges. The central University is composed of academic departments and research centres, administrative departments, libraries and museums. The 38 colleges are self-governing and financially independent institutions, which are related to the central University in a federal system. There are also six permanent private halls, which were founded by different Christian denominations and which still retain their Christian character.

    The different roles of the colleges and the University have evolved over time.

     
  • richardmitnick 8:16 am on December 17, 2019 Permalink | Reply
    Tags: "Researchers reveal how enzyme motions catalyze reactions", , , Chemistry, Enzymes, , ,   

    From SLAC National Accelerator Lab: “Researchers reveal how enzyme motions catalyze reactions” 

    From SLAC National Accelerator Lab

    December 16, 2019
    Ali Sundermier

    What they learned could lead to a better understanding of how antibiotics are broken down in the body, potentially leading to the development of more effective drugs.

    1
    This illustration shows how an enzyme moves and changes as it catalyzes complex reactions and breaks down organic compounds. (10.1073/pnas.1901864116)

    In a time-resolved X-ray experiment, researchers uncovered, at atomic resolution and in real time, the previously unknown way that a microbial enzyme breaks down organic compounds.

    The team, led by Mark Wilson at the University of Nebraska Lincoln (UNL) and Henry van den Bedem at the Department of Energy’s SLAC National Accelerator Laboratory (now at Atomwise Inc.), published their findings last week in the Proceedings of the National Academy of Sciences. What they learned about this enzyme, whose structure is similar to one that is implicated in neurodegenerative diseases such as Parkinson’s, could lead to a better understanding of how antibiotics are broken down by microbes and to the development of more effective drugs.

    Previously, the researchers used SLAC’s Stanford Synchrotron Radiation Lightsource (SSRL) to obtain the structure of the enzyme at very low temperatures using X-ray crystallography.

    SLAC/SSRL

    In this study, Medhanjali Dasgupta, a UNL graduate student who was the study’s first author, used the Linac Coherent Light Source (LCLS), SLAC’s X-ray laser, to watch the enzyme and its substrate within the crystal move and change as it went through a full catalytic cycle at room temperature.

    SLAC/LCLS

    The scientists used special software, designed by van den Bedem, that is highly sensitive to identifying protein movement from X-ray crystallography data to interpret the results, revealing never-before-seen motions that play a key role in catalyzing complex reactions, such as breaking down antibiotics. Next, the researchers hope to use LCLS to obtain room temperature structures of other enzymes to get a better look at how the motions occurring within them help move along reactions.

    SSRL and LCLS are DOE Office of Science user facilities. This work was funded by the DOE Office of Science and the National Institutes of Health, among other sources.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings
    Please help promote STEM in your local schools.

    Stem Education Coalition

    SLAC/LCLS


    SLAC/LCLS II projected view


    SLAC is a multi-program laboratory exploring frontier questions in photon science, astrophysics, particle physics and accelerator research. Located in Menlo Park, California, SLAC is operated by Stanford University for the DOE’s Office of Science.


     
  • richardmitnick 6:24 pm on December 16, 2019 Permalink | Reply
    Tags: "GODDESS detector sees the origins of elements", ATLAS-Argonne Tandem Linear Accelerator System, Chemistry, Insight into astrophysical nuclear reactions that produce the elements heavier than hydrogen., , ORRUBA-Oak Ridge Rutgers University Barrel Array, , Products of nuclear transmutations are spotted with unprecedented detail.,   

    From Oak Ridge National Laboratory and Rutgers University: “GODDESS detector sees the origins of elements” 

    i1

    From Oak Ridge National Laboratory

    with

    Rutgers smaller
    Our Great Seal.

    Rutgers University

    December 17, 2019
    Dawn M Levy
    levyd@ornl.gov
    865.576.6448

    1
    ORNL GODDESS Detector

    2
    GODDESS is shown coupled to GRETINA with experimenters, from left, Heather Garland, Chad Ummel and Gwen Seymour, all of Rutgers University, and Rajesh Ghimire of University of Tennessee–Knoxville and ORNL; and from left (back row), Josh Hooker of UTK and Steven Pain of ORNL. Credit: Andrew Ratkiewicz/Oak Ridge National Laboratory, U.S. Dept. of Energy

    Products of nuclear transmutations are spotted with unprecedented detail.

    Ancient Greeks imagined that everything in the natural world came from their goddess Physis; her name is the source of the word physics. Present-day nuclear physicists at the Department of Energy’s Oak Ridge National Laboratory have created a GODDESS of their own—a detector providing insight into astrophysical nuclear reactions that produce the elements heavier than hydrogen (this lightest of elements was created right after the Big Bang).

    Researchers developed a state-of-the-art charged particle detector at ORNL called the Oak Ridge Rutgers University Barrel Array, or ORRUBA, to study reactions with beams of astrophysically important radioactive nuclei.

    5
    Schematic of how ORRUBA would be coupled to the 100-unit Gammasphere Compton-suppressed Ge detector array. The barrel array would be augmented by up to 4 annular strip detectors to be placed at forward and backward angles in the laboratory. All electronics signals and preamplifier boxes would be downstream of ORRUBA and before the quadrupole magnet of the Fragment Mass Analyzer. Provided by Ratkiewicz and Shand.

    Recently, its silicon detectors were upgraded and tightly packed to prepare it to work in concert with large germanium-based gamma-ray detectors, such as Gammasphere, and the next-generation gamma-ray tracking detector system, GRETINA. The result is GODDESS—Gammasphere/GRETINA ORRUBA: Dual Detectors for Experimental Structure Studies. [Watch a time-lapse video below of one day of work to couple GODDESS with Gammasphere for the first time.]


    GODDESS day 4 video

    With millimeter position resolution, GODDESS records emissions from reactions taking place as energetic beams of radioactive nuclei gain or lose protons and neutrons and emit gamma rays or charged particles, such as protons, deuterons, tritons, helium-3 or alpha particles.

    “The charged particles in the silicon detectors tell us how the nucleus was formed, and the gamma rays tell us how it decayed,” explained Steven Pain of ORNL’s Physics Division. “We merge the two sets of data and use them as if they were one detector for a complete picture of the reaction.”

    Earlier this year, Pain led more than 50 scientists from 12 institutions in GODDESS experiments to understand the cosmic origins of the elements. He is principal investigator of two experiments and co-principal investigator of a third. Data analysis of the complex experiments is expected to take two years.

    “Almost all heavy stable nuclei in the universe are created through unstable nuclei reacting and then coming back to stability,” Pain said.

    A century of nuclear transmutation

    In 1911 Ernest Rutherford was astounded to observe that alpha particles—heavy and positively charged—sometimes bounced backward. He concluded they must have hit something extremely dense and positively charged—possible only if almost all an atom’s mass were concentrated in its center. He had discovered the atomic nucleus. He went on to study the nucleons—protons and neutrons—that make up the nucleus and that are surrounded by shells of orbiting electrons.

    One element can turn into another when nucleons are captured, exchanged or expelled. When this happens in stars, it’s called nucleosynthesis. Rutherford stumbled upon this process in the lab through an anomalous result in a series of particle-scattering experiments. The first artificial nuclear transmutation reacted nitrogen-14 with an alpha particle to create oxygen-17 and a proton. The feat was published in 1919, seeding advances in the newly invented cloud chamber, discoveries about short-lived nuclei (which make up 90% of nuclei), and experiments that continue to this day as a top priority for physics.

    “A century ago, the first nuclear reaction of stable isotopes was inferred by human observers counting flashes of light with a microscope,” noted Pain, who is Rutherford’s “great-great-grandson” in an academic sense: his PhD thesis advisor was Wilton Catford, whose advisor was Kenneth Allen, whose advisor was William Burcham, whose advisor was Rutherford. “Today, advanced detectors like GODDESS allow us to explore, with great sensitivity, reactions of the difficult-to-access unstable radioactive nuclei that drive the astrophysical explosions generating many of the stable elements around us.”

    Understanding thermonuclear runaway

    One experiment Pain led focused on phosphorus-30, which is important for understanding certain thermonuclear runaways. “We’re looking to understand nucleosynthesis in nova explosions—the most common stellar explosions,” he said. A nova occurs in a binary system in which a white dwarf gravitationally pulls hydrogen-rich material from a nearby “companion” star until thermonuclear runaway occurs and the white dwarf’s surface layer explodes. The ashes of these explosions change the chemical composition of the galaxy.

    University of Tennessee graduate student Rajesh Ghimire is analyzing the data from the phosphorus experiment, which transferred a neutron from deuterium in a target onto an intense beam of the short-lived radioactive isotope phosphorus-30. The particle and gamma-ray detectors spotted what emerged, correlating times, places and energies of proton and gamma ray production.

    The phosphorus-30 nucleus strongly affects the ratios of most of the heavier elements produced during a nova explosion. If the phosphorus-30 reactions are understood, the elemental ratios can be used to measure the peak temperature that the nova reached. “That’s an observable that somebody with a telescope could see,” Pain said.

    Illuminating heavy-element creation

    The second experiment Pain led transmuted a much heavier isotope, tellurium-134. “This nucleus is involved in the rapid neutron capture process, or r process, which is the way that half the elements heavier than iron are formed in the universe,” Pain related. It occurs in an environment with many free neutrons—perhaps supernovae or neutron star mergers. “We know it happens, because we see the elements around us, but we still don’t know exactly where and how it occurs.”

    Understanding r-process nucleosynthesis will be a major activity at the Facility for Rare Isotope Beams (FRIB), a DOE Office of Science user facility scheduled to open at Michigan State University (MSU) in 2022. FRIB will enable discoveries about rare isotopes, nuclear astrophysics and fundamental interactions, and applications in medicine, homeland security and industry.

    “The r process is a very, very complicated network of reactions; many, many pieces go into it,” Pain emphasized. “You can’t do one experiment and have the answer.”

    The tellurium-134 experiment starts with radioactive californium made at ORNL and installed at the Argonne Tandem Linear Accelerator System (ATLAS), a DOE Office of Science user facility at Argonne National Laboratory.

    4
    Argonne Tandem Linear Accelerator System (ATLAS)

    The californium fissions spontaneously, with tellurium-134 among the products. A beam of tellurium-134 is accelerated into a deuterium target and absorbs a neutron, spitting out a proton in the process. “Tellurium-134 comes in, but tellurium-135 goes out,” Pain summed up.

    “We detect that proton in the silicon detectors of GODDESS. The tellurium-135 continues down the beam line. The energy and angle of the proton tell us about the tellurium-135 we’ve created—it could be in its ground state or in any one of a number of excited states. The excited states decay by emitting a gamma ray.” The germanium detectors reveal the energy of the gamma rays with unprecedented resolution to show how the nucleus decayed. Then the nucleus enters a gas detector, creating a track of ionized gas from which the removed electrons are collected. Measuring the energy deposited in different regions of the detector allows researchers to definitively identify the nucleus.

    Rutgers graduate student Chad Ummel is focusing on the experiment’s analysis. Said Pain, “We’re trying to understand the role of this tellurium-134 nucleus in the r process in different potential astrophysical sites. The reaction flow in this network of neutron capture reactions affects the abundances of the elements created. We need to understand this network to understand the origin of the heavy elements.”

    Future of the GODDESS

    The researchers will continue developing equipment and techniques for current use of GODDESS at Argonne and MSU and future use at FRIB, which will give unprecedented access to many unstable nuclei currently out of reach. Future experiments will employ two strategies.

    One uses fast beams of nuclei that have been fragmented into other nuclei. Pain likens the diverse nuclear products to a whole zoo hurtling down the beam line in chaos. The fast-moving nuclei pass through a series of magnets that select desired “zebras” and discard unwanted “giraffes,” “gnus” and “hippos.”

    The other approach stops the ions with a material, re-ionizes them, then reaccelerates them before they can radioactively decay. Explained Pain, “It allows you to corral all zebras, calm them down, then orderly bring them out in the direction, rate and speed that you want.”

    Taming the elements that make planets and people possible—that’s indeed the domain of a physics GODDESS.

    DOE’s Office of Science supports Pain’s research. DOE’s National Nuclear Security Administration funded some past detector research.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings
    Please help promote STEM in your local schools.

    Stem Education Coalition

    ORNL is managed by UT-Battelle for the Department of Energy’s Office of Science. DOE’s Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time.

    i2

     
  • richardmitnick 1:42 pm on December 13, 2019 Permalink | Reply
    Tags: "Tiny Quantum Sensors Watch Materials Transform Under Pressure", , “Noise spectroscopy”-measuring the magnetic “noise” emanating from the gadolinium electrons’ motion., Chemistry, Diamond anvil cells, ,   

    From Lawrence Berkeley National Lab: “Tiny Quantum Sensors Watch Materials Transform Under Pressure” 

    Berkeley Logo

    From Lawrence Berkeley National Lab

    December 12, 2019
    Theresa Duque
    tnduque@lbl.gov
    (510) 495-2418

    1
    At left, natural diamonds glow under ultraviolet light owing to their various nitrogen-vacancy (NV) centers. At right, a schematic depicting the diamond anvils in action, with NV centers in the bottom anvil. The NV sensors glow a brilliant shade of red when excited with laser light. By probing the brightness of this fluorescence, the researchers were able to see how the sensors responded to small changes in their environment. (Credits: Norman Yao/Berkeley Lab; Ella Marushchenko)

    Since their invention more than 60 years ago, diamond anvil cells have made it possible for scientists to recreate extreme phenomena – such as the crushing pressures deep inside the Earth’s mantle – or to enable chemical reactions that can only be triggered by intense pressure, all within the confines of a laboratory apparatus that you can safely hold in the palm of your hand.

    To develop new, high-performance materials, scientists need to understand how useful properties, such as magnetism and strength, change under such harsh conditions. But often, measuring these properties with enough sensitivity requires a sensor that can withstand the crushing forces inside a diamond anvil cell.

    Since 2018, scientists at the Center for Novel Pathways to Quantum Coherence in Materials (NPQC), an Energy Frontier Research Center led by the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab), have sought to understand how the properties of electronic and optical materials can be harnessed to develop ultrasensitive sensors capable of measuring electric and magnetic fields.

    Now, a team of scientists led by Berkeley Lab and UC Berkeley, with support from the NPQC, have come up with a clever solution: By turning natural atomic flaws inside the diamond anvils into tiny quantum sensors, the scientists have developed a tool that opens the door to a wide range of experiments inaccessible to conventional sensors. Their findings, which were reported today in the journal Science, have implications for a new generation of smart, designer materials, as well as the synthesis of new chemical compounds, atomically fine-tuned by pressure.

    2
    Co-lead authors Satcher Hsieh (left) and Chong Zu tune the laser of their imaging system. When excited by laser light, NV centers emit photons whose brightness informs researchers about the local environment that they are sensing. (Credit: Marilyn Sargent/Berkeley Lab)

    Turning atomic flaws into sensors

    At the atomic level, diamonds owe their sturdiness to carbon atoms bound together in a tetrahedral crystal structure. But when diamonds form, some carbon atoms can get bumped out of their “lattice site,” a space in the crystal structure that is like their assigned parking spot. When a nitrogen atom impurity trapped in the crystal sits adjacent to an empty site, a special atomic defect forms: a nitrogen-vacancy (NV) center.

    Over the last decade, scientists have used NV centers as tiny sensors to measure the magnetism of a single protein, the electric field from a single electron, and the temperature inside a living cell, explained Norman Yao, faculty scientist in Berkeley Lab’s Materials Sciences Division and assistant professor of physics at UC Berkeley.

    To take advantage of the NV centers’ intrinsic sensing properties, Yao and colleagues engineered a thin layer of them directly inside the diamond anvil in order to take a snapshot of the physics within the high-pressure chamber.

    Imaging stress inside the diamond anvil cell

    After generating a layer of NV center sensors a few hundred atoms in thickness inside one-tenth-carat diamonds, the researchers tested the NV sensors’ ability to measure the diamond anvil cell’s high-pressure chamber.

    The sensors glow a brilliant shade of red when excited with laser light; by probing the brightness of this fluorescence, the researchers were able to see how the sensors responded to small changes in their environment.

    What they found surprised them: The NV sensors suggested that the once-flat surface of the diamond anvil began to curve in the center under pressure.

    Co-author Raymond Jeanloz, professor of earth and planetary science at UC Berkeley, and his team identified the phenomenon as “cupping” – a concentration of the pressure toward the center of the anvil tips.

    4

    “They had known about this effect for decades but were accustomed to seeing it at 20 times the pressure, where you can see the curvature by eye,” Yao said. “Remarkably, our diamond anvil sensor was able to detect this tiny curvature at even the lowest pressures.”

    There were other surprises, too. When a methanol/ethanol mixture they squeezed underwent a glass transition from a liquid to a solid, the diamond surface turned from a smooth bowl to a jagged, textured surface. Mechanical simulations performed by co-author Valery Levitas of Iowa State University and Ames Laboratory confirmed the result.

    “This is a fundamentally new way to measure phase transitions in materials at high pressure, and we hope this can complement conventional methods that utilize powerful X-ray radiation from a synchrotron source,” said lead author Satcher Hsieh, a doctoral researcher in Berkeley Lab’s Materials Sciences Division and in the Yao Group at UC Berkeley.

    Co-lead authors with Hsieh are graduate student researcher Prabudhya Bhattacharyya and postdoctoral researcher Chong Zu of the Yao Group at UC Berkeley.

    Magnetism under pressure

    In another experiment, the researchers used their array of NV sensors to capture a magnetic “snapshot” of iron and gadolinium.

    Iron and gadolinium are magnetic metals. Scientists have long known that compressing iron and gadolinium can alter them from a magnetic phase to a nonmagnetic phase, an outcome of what scientists call a “pressure-induced phase transition.” In the case of iron, the researchers directly imaged this transition by measuring the depletion of the magnetic field generated by a micron-size (or one millionth of a meter) bead of iron inside the high-pressure chamber.

    4
    Co-lead author Satcher Hsieh preparing a sample to be compressed in the diamond anvil cell. (Credit: Marilyn Sargent/Berkeley Lab)

    In the case of gadolinium, the researchers took a different approach. In particular, the electrons inside gadolinium “happily whiz around in random directions,” and this chaotic “mosh pit” of electrons generates a fluctuating magnetic field that the NV sensor can measure, Hsieh said.

    The researchers noted that the NV center sensors can flip into different magnetic quantum states in the presence of magnetic fluctuations, much like how a compass needle spins in different directions when you wave a bar magnet near it.

    So they postulated that by timing how long it took for the NV centers to flip from one magnetic state to another, they could characterize the gadolinium’s magnetic phase by measuring the magnetic “noise” emanating from the gadolinium electrons’ motion.

    They found that when gadolinium is in a non-magnetic phase, its electrons are subdued, and its magnetic field fluctuations hence are weak. Subsequently, the NV sensors stay in a single magnetic quantum state for a long while – nearly a hundred microseconds.

    Conversely, when the gadolinium sample changed to a magnetic phase, the electrons moved around rapidly, causing the nearby NV sensor to swiftly flip to another magnetic quantum state.

    This sudden change provided clear evidence that gadolinium had entered a different magnetic phase, Hsieh said, adding that their technique allowed them to pinpoint magnetic properties across the sample with submicron precision as opposed to averaging over the entire high-pressure chamber as in previous studies.

    The researchers hope that this “noise spectroscopy” technique will provide scientists with a new tool for exploring phases of magnetic matter that can be used as the foundation for smaller, faster, and cheaper ways of storing and processing data through next-generation ultrafast spintronic devices.

    Next steps

    Now that they’ve demonstrated how to engineer NV centers into diamond anvil cells, the researchers plan to use their device to explore the magnetic behavior of superconducting hydrides – materials that conduct electricity without loss near room temperature at high pressure, which could revolutionize how energy is stored and transferred.

    And they would also like to explore science outside of physics. “What’s most exciting to me is that this tool can help so many different scientific communities,” says Hsieh. “It’s sprung up collaborations with groups ranging from high-pressure chemists to Martian paleomagnetists to quantum materials scientists.”

    Researchers from Berkeley Lab; UC Berkeley; Ludwig-Maximilian University of Munich, Germany; Iowa State University; Carnegie Institution of Washington, Washington, D.C.; and Ames Laboratory participated in the work.

    This work was supported by the Center for Novel Pathways to Quantum Coherence in Materials, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science. Additional funding was provided by the Army Research Office and the National Science Foundation.

    Additional Information: The December 13 issue of Science features two complementary studies about NV-based magnetic sensing at high pressures as well as a Perspective article:

    Magnetic Measurements on Micrometer-Sized Samples Under High Pressure Using Designed NV Centers
    Measuring Magnetic Field Texture in Correlated Electron Systems Under Extreme Conditions
    Extreme Diamond-Based Quantum Sensors

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    LBNL campus

    LBNL Molecular Foundry

    Bringing Science Solutions to the World
    In the world of science, Lawrence Berkeley National Laboratory (Berkeley Lab) is synonymous with “excellence.” Thirteen Nobel prizes are associated with Berkeley Lab. Seventy Lab scientists are members of the National Academy of Sciences (NAS), one of the highest honors for a scientist in the United States. Thirteen of our scientists have won the National Medal of Science, our nation’s highest award for lifetime achievement in fields of scientific research. Eighteen of our engineers have been elected to the National Academy of Engineering, and three of our scientists have been elected into the Institute of Medicine. In addition, Berkeley Lab has trained thousands of university science and engineering students who are advancing technological innovations across the nation and around the world.

    Berkeley Lab is a member of the national laboratory system supported by the U.S. Department of Energy through its Office of Science. It is managed by the University of California (UC) and is charged with conducting unclassified research across a wide range of scientific disciplines. Located on a 202-acre site in the hills above the UC Berkeley campus that offers spectacular views of the San Francisco Bay, Berkeley Lab employs approximately 3,232 scientists, engineers and support staff. The Lab’s total costs for FY 2014 were $785 million. A recent study estimates the Laboratory’s overall economic impact through direct, indirect and induced spending on the nine counties that make up the San Francisco Bay Area to be nearly $700 million annually. The Lab was also responsible for creating 5,600 jobs locally and 12,000 nationally. The overall economic impact on the national economy is estimated at $1.6 billion a year. Technologies developed at Berkeley Lab have generated billions of dollars in revenues, and thousands of jobs. Savings as a result of Berkeley Lab developments in lighting and windows, and other energy-efficient technologies, have also been in the billions of dollars.

    Berkeley Lab was founded in 1931 by Ernest Orlando Lawrence, a UC Berkeley physicist who won the 1939 Nobel Prize in physics for his invention of the cyclotron, a circular particle accelerator that opened the door to high-energy physics. It was Lawrence’s belief that scientific research is best done through teams of individuals with different fields of expertise, working together. His teamwork concept is a Berkeley Lab legacy that continues today.

    A U.S. Department of Energy National Laboratory Operated by the University of California.

    University of California Seal

     
  • richardmitnick 1:36 pm on December 10, 2019 Permalink | Reply
    Tags: "Meet the microorganism that likes to eat meteorites", , , , Chemistry, , , For this study the researchers ran tests on material from a meteorite labeled Northwest Africa 1172 (NWA 1172)., , Redox is is a type of chemical reaction in which the oxidation states of atoms are changed and is common in biological processes., The microbe M. sedula,   

    From University of Vienna via EarthSky: “Meet the microorganism that likes to eat meteorites” 

    From University of Vienna

    via

    1

    EarthSky

    December 10, 2019
    Paul Scott Anderson

    At least one type of microbe on Earth not only likes to eat meteorites but actually prefers them as a food source, according to a new international scientific study.

    1
    Meteorite dust fragments colonized and bioprocessed by the microbe M. sedula. Image via Tetyana Milojevic/ Universität Wien.

    You’ve gotta eat to live. That’s a truism not just for humans but for other lifeforms, including microbes. Now an international team of scientists has announced a new study, showing that at least one type of earthly bacteria has a fondness for extraterrestrial food: meteorites, or rocks from space. These microbes even seem to prefer space rocks to their usual earthly fare of earthly rocks.

    The intriguing peer-reviewed results were published in Nature Scientific Reports on December 2, 2019.

    Astrobiologist Tetyana Milojevic of the University of Vienna in Austria led the research, which demonstrated that an ancient single-celled bacteria known as Metallosphaera sedula (M. sedula) can not only process material in meteorites for food, but will even colonize meteorites faster than earthly rocks.

    M. sedula belong to a family of bacteria known as lithotrophs; that is, they derive their energy from inorganic sources. The term “lithotroph” was created from the Greek terms ‘lithos’ (rock) and ‘troph’ (consumer), meaning “eaters of rock.”

    For this study, the researchers ran tests on material from a meteorite labeled Northwest Africa 1172 (NWA 1172). They found that the microbes colonized the material much more quickly than they would terrestrial material.

    3
    Graphic showing the ingestion of inorganic material by the microbe M. sedula in the meteorite NWA 1172. Image via Tetyana Milojevic/ Universität Wien.

    As Milojevic said in a statement:

    “Meteorite-fitness seems to be more beneficial for this ancient microorganism than a diet on terrestrial mineral sources. NWA 1172 is a multimetallic material, which may provide much more trace metals to facilitate metabolic activity and microbial growth. Moreover, the porosity of NWA 1172 might also reflect the superior growth rate of M. sedula.”

    This is certainly interesting, suggesting that M. sedula actually prefers the material coming from space over its local, home-grown, earthly food sources.

    4
    Scanning electron microscope image of meteorite NWA 1172, showing colonization of M. sedula microbes. Image via Tetyana Milojevic/ Universität Wien/ Daily Mail.

    So how did the scientists make these findings?

    “They examined the meteorite-microbial interface at nanometer scale – one billionth of a meter – and traced how the material was consumed, investigating the iron redox behavior. Redox is is a type of chemical reaction in which the oxidation states of atoms are changed, and is common in biological processes. By combining several analytical spectroscopy techniques with transmission electron microscopy, they found a set of biogeochemical fingerprints left upon M. sedula growth on the meteorite. As Milojevic explained:

    Our investigations validate the ability of M. sedula to perform the biotransformation of meteorite minerals, unravel microbial fingerprints left on meteorite material, and provide the next step towards an understanding of meteorite biogeochemistry.”

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    The University of Vienna (German: Universität Wien) is a public university located in Vienna, Austria. It was founded by Duke Rudolph IV in 1365 and is one of the oldest universities in the German-speaking world. With its long and rich history, the University of Vienna has developed into one of the largest universities in Europe, and also one of the most renowned, especially in the Humanities. It is associated with 15 Nobel prize winners and has been the academic home to a large number of scholars of historical as well as of academic importance.

     
c
Compose new post
j
Next post/Next comment
k
Previous post/Previous comment
r
Reply
e
Edit
o
Show/Hide comments
t
Go to top
l
Go to login
h
Show/Hide help
shift + esc
Cancel
%d bloggers like this: