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  • richardmitnick 7:01 pm on March 4, 2020 Permalink | Reply
    Tags: "A small step for atoms a giant leap for microelectronics", , Gordon Moore's prediction is getting "long in the tooth"., In 1975 Intel’s Gordon Moore predicted that the number of transistors in an integrated circuit would double every two years., , Rice University, Step by step scientists are figuring out new ways to extend Moore’s Law. The latest reveals a path toward integrated circuits with two-dimensional transistors., The ability to stack 2D layers each with millions of transistors may overcome such limitations if they can be isolated from one other., The main discovery in this work is that a monocrystal across a wafer can be achieved and then they can move it.   

    From Rice University: “A small step for atoms, a giant leap for microelectronics” 

    Rice U bloc

    From Rice University

    March 4, 2020
    Jeff Falk
    713-348-6775
    jfalk@rice.edu

    Mike Williams
    713-348-6728
    mikewilliams@rice.edu

    1
    Atoms of boron and nitride align on a copper substrate to create a large-scale, ordered crystal of hexagonal boron nitride. The wafer-sized material could become a key insulator in future two-dimensional electronics. Illustration by Tse-An Chen/TSMC

    Step by step, scientists are figuring out new ways to extend Moore’s Law. The latest reveals a path toward integrated circuits with two-dimensional transistors.

    A Rice University scientist and his collaborators in Taiwan and China reported in Nature today that they have successfully grown atom-thick sheets of hexagonal boron nitride (hBN) as two-inch diameter crystals across a wafer.

    Surprisingly, they achieved the long-sought goal of making perfectly ordered crystals of hBN, a wide band gap semiconductor, by taking advantage of disorder among the meandering steps on a copper substrate. The random steps keep the hBN in line.

    Set into chips as a dielectric between layers of nanoscale transistors, wafer-scale hBN would excel in damping electron scattering and trapping that limit the efficiency of an integrated circuit. But until now, nobody has been able to make perfectly ordered hBN crystals that are large enough — in this case, on a wafer — to be useful.

    Brown School of Engineering materials theorist Boris Yakobson is co-lead scientist on the study with Lain-Jong (Lance) Li of the Taiwan Semiconductor Manufacturing Co. (TSMC) and his team. Yakobson and Chih-Piao Chuu of TSMC performed theoretical analysis and first principles calculations to unravel the mechanisms of what their co-authors saw in experiments.

    As a proof of concept for manufacturing, experimentalists at TSMC and Taiwan’s National Chiao Tung University grew a two-inch, 2D hBN film, transferred it to silicon and then placed a layer of field-effect transistors patterned onto 2D molybdenum disulfide atop the hBN.

    “The main discovery in this work is that a monocrystal across a wafer can be achieved, and then they can move it,” Yakobson said. “Then they can make devices.”

    “There is no existing method that can produce hBN monolayer dielectrics with extremely high reproducibility on a wafer, which is necessary for the electronics industry,” Li added. “This paper reveals the scientific reasons why we can achieve this.”

    Yakobson hopes the technique may also apply broadly to other 2D materials, with some trial and error. “I think the underlying physics is pretty general,” he said. “Boron nitride is a big-deal material for dielectrics, but many desirable 2D materials, like the 50 or so transition metal dichalcogenides, have the same issues with growth and transfer, and may benefit from what we discovered.”

    In 1975, Intel’s Gordon Moore predicted that the number of transistors in an integrated circuit would double every two years. But as integrated circuit architectures get smaller, with circuit lines down to a few nanometers, the pace of progress has been hard to maintain.

    The ability to stack 2D layers, each with millions of transistors, may overcome such limitations if they can be isolated from one other. Insulating hBN is a prime candidate for that purpose because of its wide band gap.

    Despite having “hexagonal” in its name, monolayers of hBN as seen from above appear as a superposition of two distinct triangular lattices of boron and nitrogen atoms. For the material to perform up to spec, hBN crystals must be perfect; that is, the triangles have to be connected and all point in the same direction. Non-perfect crystals have grain boundaries that degrade the material’s electronic properties.

    For hBN to become perfect, its atoms have to precisely align with those on the substrate below. The researchers found that copper in a (111) arrangement — the number refers to how the crystal surface is oriented — does the job, but only after the copper is annealed at high temperature on a sapphire substrate and in the presence of hydrogen.

    Annealing eliminates grain boundaries in the copper, leaving a single crystal. Such a perfect surface would, however, be “way too smooth” to enforce the hBN orientation, Yakobson said.

    Yakobson reported on research last year to grow pristine borophene on silver (111), and also a theoretical prediction that copper can align hBN by virtue of the complementary steps on its surface. The copper surface was vicinal — that is, slightly miscut to expose atomic steps between the expansive terraces. That paper caught the attention of industrial researchers in Taiwan, who approached the professor after a talk there last year.

    “They said, ‘We read your paper,’” Yakobson recalled. “‘We see something strange in our experiments. Can we talk?’ That’s how it started.”

    Informed by his earlier experience, Yakobson suggested that thermal fluctuations allow copper (111) to retain step-like terraces across its surface, even when its own grain boundaries are eliminated. The atoms in these meandering “steps” present just the right interfacial energies to bind and constrain hBN, which then grows in one direction while it attaches to the copper plane via the very weak van der Waals force.

    2
    Researchers in Taiwan, China and at Rice made wafer-sized, two-dimensional sheets of hexagonal boron nitride, as reported in Nature. The material may be removed from its copper substrate and used as a dielectric for two-dimensional electronics.

    “Every surface has steps, but in the prior work, the steps were on a hard-engineered vicinal surface, which means they all go down, or all up,” he said. “But on copper (111), the steps are up and down, by just an atom or two randomly, offered by the fundamental thermodynamics.”

    Because of the copper’s orientation, the horizontal atomic planes are offset by a fraction to the lattice underneath. “The surface step-edges look the same, but they’re not exact mirror-twins,” Yakobson explained. “There’s a larger overlap with the layer below on one side than on the opposite.”

    That makes the binding energies on each side of the copper plateau different by a minute 0.23 electron volts (per every quarter-nanometer of contact), which is enough to force docking hBN nuclei to grow in the same direction, he said.

    The experimental team found the optimal copper thickness was 500 nanometers, enough to prevent its evaporation during hBN growth via chemical vapor deposition of ammonia borane on a copper (111)/sapphire substrate.

    Tse-An Chen of TSMC is co-lead author of the paper. Co-authors are Chien-Chih Tseng, Chao-Kai Wen, Wei-Chen Chueh and Wen-Hao Chang of Chiao Tung; H.-S. Philip Wong and Tsu-Ang Chao of TSMC; Shuangyuan Pan and Yanfeng Zhang of Peking University, China; Qiang Fu of the Chinese Academy of Sciences, Dalian, China; and Rongtan Li of the Chinese Academy of Sciences and the University of Chinese Academy of Sciences, Beijing.

    Yakobson is the Karl F. Hasselmann Professor of Materials Science and NanoEngineering and a professor of chemistry at Rice. Chang is a professor at Chiao Tung and director of the university’s Center for Emergent Functional Matter Science. Li is Director, Corporate Research, Taiwan Semiconductor Manufacturing Co.

    The research was supported by TSMC, the Ministry of Science and Technology of Taiwan, the Ministry of Education of Taiwan, the National Natural Science Foundation of China, the Chinese Academy of Sciences and the U.S. Department of Energy.

    See the full article here .


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


    Stem Education Coalition

    Rice U campus

    In his 1912 inaugural address, Rice University president Edgar Odell Lovett set forth an ambitious vision for a great research university in Houston, Texas; one dedicated to excellence across the range of human endeavor. With this bold beginning in mind, and with Rice’s centennial approaching, it is time to ask again what we aspire to in a dynamic and shrinking world in which education and the production of knowledge will play an even greater role. What shall our vision be for Rice as we prepare for its second century, and how ought we to advance over the next decade?

    This was the fundamental question posed in the Call to Conversation, a document released to the Rice community in summer 2005. The Call to Conversation asked us to reexamine many aspects of our enterprise, from our fundamental mission and aspirations to the manner in which we define and achieve excellence. It identified the pressures of a constantly changing and increasingly competitive landscape; it asked us to assess honestly Rice’s comparative strengths and weaknesses; and it called on us to define strategic priorities for the future, an effort that will be a focus of the next phase of this process.

     
  • richardmitnick 12:13 pm on February 24, 2020 Permalink | Reply
    Tags: "Rice scientists simplify access to drug building block", , , , Rice University   

    From Rice University: “Rice scientists simplify access to drug building block” 

    Rice U bloc

    From Rice University

    February 24, 2020
    Mike Williams

    László Kürti and team develop one-step process to make crucial precursor.

    In one pot, at room temperature, chemists at Rice University are able to make valuable pharmaceutical precursors they say could change the industry.

    The Rice group of chemist László Kürti introduced an inexpensive organic synthesis technique that catalyzes the transfer of nitrogen atoms to olefins, unsaturated organic compounds also known as alkenes.

    Exposed nitrogen atoms are critical to drug discovery. The Rice process combines nitrogen and hydrogen atoms in triangular aziridine products that are readily available to react with other agents.

    1
    A Rice University method to produce aziridines, building blocks in drug design, makes the process far less expensive and more environmentally friendly than current methods that use metal catalysts. Courtesy of the Kürti Research Group.

    Most important, Kürti said, is that his lab’s organocatalytic aziridination process transfers nitrogen to olefins that haven’t already been modified, or functionalized.

    “These unactivated olefins are commodity chemicals, but very difficult to functionalize,” he said. “We are able to do that now with this chemistry under operationally simple and mild conditions.”

    Turning them into nitrogen-containing small molecules makes them far more useful, he said. “You can then convert them to more complex molecules,” he said. “These N-H aziridines are essential building blocks.”

    The lab detailed its new aziridination technique in Nature Catalysis.

    Kürti and his crew have been stepping toward this point for years, first eliminating expensive catalysts from the process of transferring nitrogen to arylmetals, and later taking enol ethers and transferring nitrogen to them to make amino ketones, a feedstock for the chemical industry.

    “The direct amination of enol ethers was a nice breakthrough because we didn’t need any catalyst,” he said. “The solvent was promoting the actual nitrogen-transfer process. Then we asked if we could replace the currently used precious metal catalysts with a small organic molecule at just a fraction of the cost to make aziridines.”

    The new study provides a definitive yes. “This has been a dream of ours for a long time,” Kürti said.

    Kürti and postdoctoral associate and co-author Zhe Zhou estimated the commercially available organic small molecule catalyst needed for the process is about 4,000 times less expensive than the rhodium-based catalysts in common use. They also make the process more sustainable.

    “Everybody thinks catalysis is the answer for our problems, and in many cases it’s true,” Kürti said. “In a difficult reaction, a small amount of catalyst will accelerate the process and save time and money.

    “But many people forget the cost of the catalyst, and whether it’s sustainable,” he said. “Unfortunately, it’s become pretty clear that we’re using high-value catalysts that contain precious metals. The world supply is limited, and the prices of these metals are at best erratic.”

    The Rice process comes with one disadvantage, however. “It’s slower than the rhodium-catalyzed process,” Kürti said. “What we disclose here takes about six hours at room temperature, where the rhodium-catalyzed process, depending on the substrate, ranges between 10 minutes and a half hour.

    “You definitely give up a little bit there,” he said. “But six hours is tolerable if you’re making big batches. That’s what I hope people will recognize in the long run.”

    Kürti hopes to refine the process to control how the nitrogen attaches to the olefin and then, in turn, control the essential chirality, or handedness, of the product. The chirality of a drug is critical to how well it works, if at all.

    Until then, the current process could be of great interest to industry, he said.

    “Easier access to previously difficult-to-obtain precursors can actually influence the compound structures that chemists will make in the in the lab,” Kürti said. “Simple procedures that are straightforward to use tend to dominate in pharmaceutical drug development.”

    Former Rice postdoctoral researcher Qing-Qing Cheng, now a postdoctoral researcher at the Scripps Research Institute, is lead author of the paper. Co-authors include associate professor Xinhao Zhang and graduate student Heming Jiang of the Peking University Shenzhen Graduate School and Shenzhen Bay Laboratory; Rice lecturer Juha Siitonen; and Daniel Ess, an associate professor of chemistry and biochemistry at Brigham Young University. Kürti is an associate professor of chemistry at Rice.

    The National Institutes of Health, the National Science Foundation, the Robert A. Welch Foundation, Shenzhen STIC and the Shenzhen San-Ming Project supported the research.

    See the full article here .


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


    Stem Education Coalition

    Rice U campus

    In his 1912 inaugural address, Rice University president Edgar Odell Lovett set forth an ambitious vision for a great research university in Houston, Texas; one dedicated to excellence across the range of human endeavor. With this bold beginning in mind, and with Rice’s centennial approaching, it is time to ask again what we aspire to in a dynamic and shrinking world in which education and the production of knowledge will play an even greater role. What shall our vision be for Rice as we prepare for its second century, and how ought we to advance over the next decade?

    This was the fundamental question posed in the Call to Conversation, a document released to the Rice community in summer 2005. The Call to Conversation asked us to reexamine many aspects of our enterprise, from our fundamental mission and aspirations to the manner in which we define and achieve excellence. It identified the pressures of a constantly changing and increasingly competitive landscape; it asked us to assess honestly Rice’s comparative strengths and weaknesses; and it called on us to define strategic priorities for the future, an effort that will be a focus of the next phase of this process.

     
  • richardmitnick 10:57 am on February 1, 2020 Permalink | Reply
    Tags: , , Geologist Melodie French, , , Rice University,   

    From Rice University: Women in STEM-“Fed grant backs Rice earthquake research” Geologist Melodie French 

    Rice U bloc

    From Rice University

    January 31, 2020

    Jeff Falk
    713-348-6775
    jfalk@rice.edu

    Mike Williams
    713-348-6728
    mikewilliams@rice.edu

    Geologist Melodie French wins National Science Foundation CAREER Award.

    1
    Rice University geologist Melodie French has earned a National Science Foundation CAREER Award to support her investigation of the tectonic roots of earthquakes and tsunamis. Photo by Jeff Fitlow.

    The tectonic plates of the world were mapped in 1996, USGS.

    Rice University geologist Melodie French is crushing it in her quest to understand the physics responsible for earthquakes.

    The assistant professor of Earth, environmental and planetary science has earned a prestigious CAREER Award, a five-year National Science Foundation (NSF) grant for $600,000 to support her investigation of the tectonic roots of earthquakes and tsunamis.

    CAREER awards support the research and educational development of young scholars likely to become leaders in their fields. The grants, among the most competitive awarded by the NSF, go to fewer than 400 scholars each year across all disciplines.

    For French, the award gives her Rice lab the opportunity to study rocks exhumed from subduction zones at plate boundaries that are often the source of megathrust earthquakes and tsunamis. Her lab squeezes rock samples to characterize the strength of the rocks deep underground where the plates meet.

    “Fundamentally, we hope to learn how the material properties of the rocks themselves control where earthquakes happen, how big one might become, what causes an earthquake to sometimes arrest after only a small amount of slip or what allows some to grow quite large,” French said.

    “A lot of geophysics involves putting out instruments to see signals that propagate to the Earth’s surface,” she said. “But we try to understand the properties of the rocks that allow these different phenomena to happen.”

    That generally involves putting rocks under extreme stress. “We squish rocks at different temperatures and pressures and at different rates while measuring force and strain in as many dimensions as we can,” French said. “That gives us a full picture of how the rocks deform under different conditions.”

    The lab conducts experiments on both exposed surface rocks that were once deep within subduction zones and rock acquired by drilling for core samples.

    2
    Rice University geologist Melodie French and graduate student Ben Belzer work with a rock sample. French has been granted a National Science Foundation CAREER Award to study the tectonic roots of earthquakes and tsunamis. Photo by Jeff Fitlow.

    I’m working with (Rice Professor) Juli Morgan on a subduction zone off of New Zealand where they drilled through part of the fault zone and brought rock up from about 500 meters deep,” French said. “But many big earthquakes happen much deeper than we could ever drill. So we need to go into the field to find ancient subduction rocks that have somehow managed to come to the surface.”

    French is not sure if it will ever be possible to accurately predict earthquakes. “But one thing we can do is create better hazard maps to help us understand what regions should be prepared for quakes,” she said.

    French is a native of Maine who earned her bachelor’s degree at Oberlin College, a master’s at the University of Wisconsin-Madison and a Ph.D. at Texas A&M University.

    The award, co-funded by the NSF’s Geophysics, Tectonics and Marine Geology and Geophysics programs, will also provide inquiry-based educational opportunities in scientific instrument design and use to K-12 students as well as undergraduate and graduate-level students.

    3
    Geologist Melodie French sets up an experiment in her Rice University lab. She has won a National Science Foundation CAREER Award, a prestigious grant given to young scholars likely to become leaders in their fields. (Credit: Jeff Fitlow/Rice University)

    See the full article here .


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


    Stem Education Coalition

    Rice U campus

    In his 1912 inaugural address, Rice University president Edgar Odell Lovett set forth an ambitious vision for a great research university in Houston, Texas; one dedicated to excellence across the range of human endeavor. With this bold beginning in mind, and with Rice’s centennial approaching, it is time to ask again what we aspire to in a dynamic and shrinking world in which education and the production of knowledge will play an even greater role. What shall our vision be for Rice as we prepare for its second century, and how ought we to advance over the next decade?

    This was the fundamental question posed in the Call to Conversation, a document released to the Rice community in summer 2005. The Call to Conversation asked us to reexamine many aspects of our enterprise, from our fundamental mission and aspirations to the manner in which we define and achieve excellence. It identified the pressures of a constantly changing and increasingly competitive landscape; it asked us to assess honestly Rice’s comparative strengths and weaknesses; and it called on us to define strategic priorities for the future, an effort that will be a focus of the next phase of this process.

     
  • richardmitnick 7:42 pm on January 16, 2020 Permalink | Reply
    Tags: "Study finds billions of quantum entangled electrons in ‘strange metal", , , , , Quantum entanglement is the basis for storage and processing of quantum information., Rice University, Terahertz spectroscopy, With strange metals there is an unusual connection between electrical resistance and temperature.   

    From Rice University: “Study finds billions of quantum entangled electrons in ‘strange metal” 

    Rice U bloc

    From Rice University

    January 16, 2020
    Jade Boyd

    Physicists provide direct evidence of entanglement’s role in quantum criticality.

    In a new study, U.S. and Austrian physicists have observed quantum entanglement among “billions of billions” of flowing electrons in a quantum critical material.

    1
    Junichiro Kono (left) and Qimiao Si in Kono’s Rice University laboratory in December 2019. (Photo by Jeff Fitlow/Rice University)

    The research, which appears this week in Science, examined the electronic and magnetic behavior of a “strange metal” compound of ytterbium, rhodium and silicon as it both neared and passed through a critical transition at the boundary between two well-studied quantum phases.

    The study at Rice University and Vienna University of Technology (TU Wien) provides the strongest direct evidence to date of entanglement’s role in bringing about quantum criticality, said study co-author Qimiao Si of Rice.

    “When we think about quantum entanglement, we think about small things,” Si said. “We don’t associate it with macroscopic objects. But at a quantum critical point, things are so collective that we have this chance to see the effects of entanglement, even in a metallic film that contains billions of billions of quantum mechanical objects.”

    Si, a theoretical physicist and director of the Rice Center for Quantum Materials (RCQM), has spent more than two decades studying what happens when materials like strange metals and high-temperature superconductors change quantum phases. Better understanding such materials could open the door to new technologies in computing, communications and more.

    The international team overcame several challenges to get the result. TU Wien researchers developed a highly complex materials synthesis technique to produce ultrapure films containing one part ytterbium for every two parts rhodium and silicon (YbRh2Si2). At absolute zero temperature, the material undergoes a transition from one quantum phase that forms a magnetic order to another that does not.

    2
    Physicist Silke Bühler-Paschen of the Vienna University of Technology (Photo by Luisa Puiu/TU Wien)

    At Rice, study co-lead author Xinwei Li, then a graduate student in the lab of co-author and RCQM member Junichiro Kono, performed terahertz spectroscopy experiments on the films at temperatures as low as 1.4 Kelvin. The terahertz measurements revealed the optical conductivity of the YbRh2Si2 films as they were cooled to a quantum critical point that marked the transition from one quantum phase to another.

    “With strange metals, there is an unusual connection between electrical resistance and temperature,” said corresponding author Silke Bühler-Paschen of TU Wien’s Institute for Solid State Physics. “In contrast to simple metals such as copper or gold, this does not seem to be due to the thermal movement of the atoms, but to quantum fluctuations at the absolute zero temperature.”

    To measure optical conductivity, Li shined coherent electromagnetic radiation in the terahertz frequency range on top of the films and analyzed the amount of terahertz rays that passed through as a function of frequency and temperature. The experiments revealed “frequency over temperature scaling,” a telltale sign of quantum criticality, the authors said.

    Kono, an engineer and physicist in Rice’s Brown School of Engineering, said the measurements were painstaking for Li, who’s now a postdoctoral researcher at the California Institute of Technology. For example, only a fraction of the terahertz radiation shined onto the sample passed through to the detector, and the important measurement was how much that fraction rose or fell at different temperatures.

    3
    Former Rice University graduate student Xinwei Li in 2016 with the terahertz spectrometer he later used to measure entanglement in the conduction electrons flowing through a “strange metal” compound of ytterbium, rhodium and silicon. (Photo by Jeff Fitlow/Rice University)

    “Less than 0.1% of the total terahertz radiation was transmitted, and the signal, which was the variation of conductivity as a function of frequency, was a further few percent of that,” Kono said. “It took many hours to take reliable data at each temperature to average over many, many measurements, and it was necessary to take data at many, many temperatures to prove the existence of scaling.

    “Xinwei was very, very patient and persistent,” Kono said. “In addition, he carefully processed the huge amounts of data he collected to unfold the scaling law, which was really fascinating to me.”

    Making the films was even more challenging. To grow them thin enough to pass terahertz rays, the TU Wien team developed a unique molecular beam epitaxy system and an elaborate growth procedure. Ytterbium, rhodium and silicon were simultaneously evaporated from separate sources in the exact 1-2-2 ratio. Because of the high energy needed to evaporate rhodium and silicon, the system required a custom-made ultrahigh vacuum chamber with two electron-beam evaporators.

    “Our wild card was finding the perfect substrate: germanium,” said TU Wien graduate student Lukas Prochaska, a study co-lead author. The germanium was transparent to terahertz, and had “certain atomic distances (that were) practically identical to those between the ytterbium atoms in YbRh2Si2, which explains the excellent quality of the films,” he said.

    Si recalled discussing the experiment with Bühler-Paschen more than 15 years ago when they were exploring the means to test a new class of quantum critical point. The hallmark of the quantum critical point that they were advancing with co-workers is that the quantum entanglement between spins and charges is critical.

    4
    Former Rice University graduate student Xinwei Li (left) and Professor Junichiro Kono in 2016 with the terahertz spectrometer Li used to measure quantum entanglement in YbRh2Si2. (Photo by Jeff Fitlow/Rice University)

    “At a magnetic quantum critical point, conventional wisdom dictates that only the spin sector will be critical,” he said. “But if the charge and spin sectors are quantum-entangled, the charge sector will end up being critical as well.”

    At the time, the technology was not available to test the hypothesis, but by 2016, the situation had changed. TU Wien could grow the films, Rice had recently installed a powerful microscope that could scan them for defects, and Kono had the terahertz spectrometer to measure optical conductivity. During Bühler-Paschen’s sabbatical visit to Rice that year, she, Si, Kono and Rice microscopy expert Emilie Ringe received support to pursue the project via an Interdisciplinary Excellence Award from Rice’s newly established Creative Ventures program.

    “Conceptually, it was really a dream experiment,” Si said. “Probe the charge sector at the magnetic quantum critical point to see whether it’s critical, whether it has dynamical scaling. If you don’t see anything that’s collective, that’s scaling, the critical point has to belong to some textbook type of description. But, if you see something singular, which in fact we did, then it is very direct and new evidence for the quantum entanglement nature of quantum criticality.”

    Si said all the efforts that went into the study were well worth it, because the findings have far-reaching implications.

    “Quantum entanglement is the basis for storage and processing of quantum information,” Si said. “At the same time, quantum criticality is believed to drive high-temperature superconductivity. So our findings suggest that the same underlying physics — quantum criticality — can lead to a platform for both quantum information and high-temperature superconductivity. When one contemplates that possibility, one cannot help but marvel at the wonder of nature.”

    Si is the Harry C. and Olga K. Wiess Professor in Rice’s Department of Physics and Astronomy. Kono is a professor in Rice’s departments of Electrical and Computer Engineering, Physics and Astronomy, and Materials Science and NanoEngineering and the director of Rice’s Applied Physics Graduate Program. Ringe is now at the University of Cambridge.

    Additional co-authors include Maxwell Andrews, Maximilian Bonta, Werner Schrenk, Andreas Limbeck and Gottfried Strasser, all of the TU Wien; Hermann Detz, formerly of TU Wien and currently at Brno University; Elisabeth Bianco, formerly of Rice and currently at Cornell University; Sadegh Yazdi, formerly of Rice and currently at the University of Colorado Boulder; and co-lead author Donald MacFarland, formerly of TU Wien and currently at the University at Buffalo.

    The research was supported by the European Research Council, the Army Research Office, the Austrian Science Fund, the European Union’s Horizon 2020 program, the National Science Foundation, the Robert A. Welch Foundation, Los Alamos National Laboratory and Rice University.

    RCQM leverages global partnerships and the strengths of more than 20 Rice research groups to address questions related to quantum materials. RCQM is supported by Rice’s offices of the provost and the vice provost for research, the Wiess School of Natural Sciences, the Brown School of Engineering, the Smalley-Curl Institute and the departments of Physics and Astronomy, Electrical and Computer Engineering, and Materials Science and NanoEngineering.

    See the full article here .


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


    Stem Education Coalition

    Rice U campus

    In his 1912 inaugural address, Rice University president Edgar Odell Lovett set forth an ambitious vision for a great research university in Houston, Texas; one dedicated to excellence across the range of human endeavor. With this bold beginning in mind, and with Rice’s centennial approaching, it is time to ask again what we aspire to in a dynamic and shrinking world in which education and the production of knowledge will play an even greater role. What shall our vision be for Rice as we prepare for its second century, and how ought we to advance over the next decade?

    This was the fundamental question posed in the Call to Conversation, a document released to the Rice community in summer 2005. The Call to Conversation asked us to reexamine many aspects of our enterprise, from our fundamental mission and aspirations to the manner in which we define and achieve excellence. It identified the pressures of a constantly changing and increasingly competitive landscape; it asked us to assess honestly Rice’s comparative strengths and weaknesses; and it called on us to define strategic priorities for the future, an effort that will be a focus of the next phase of this process.

     
  • richardmitnick 4:05 pm on December 9, 2019 Permalink | Reply
    Tags: "Rice and Amazon report breakthrough in ‘distributed deep learning", , Rice University   

    From Rice University: “Rice, Amazon report breakthrough in ‘distributed deep learning” 

    Rice U bloc

    From Rice University

    December 9, 2019
    Jade Boyd

    Online shoppers typically string together a few words to search for the product they want, but in a world with millions of products and shoppers, the task of matching those unspecific words to the right product is one of the biggest challenges in information retrieval.

    Using a divide-and-conquer approach that leverages the power of compressed sensing, computer scientists from Rice University and Amazon have shown they can slash the amount of time and computational resources it takes to train computers for product search and similar “extreme classification problems” like speech translation and answering general questions.

    The research will be presented this week at the 2019 Conference on Neural Information Processing Systems (NeurIPS 2019) in Vancouver. The results include tests performed in 2018 when lead researcher Anshumali Shrivastava and lead author Tharun Medini, both of Rice, were visiting Amazon Search in Palo Alto, California.

    1
    Anshumali Shrivastava, assistant professor of computer science at Rice University. (Photo by Jeff Fitlow/Rice University)

    In tests on an Amazon search dataset that included some 70 million queries and more than 49 million products, Shrivastava, Medini and colleagues showed their approach of using “merged-average classifiers via hashing,” (MACH) required a fraction of the training resources of some state-of-the-art commercial systems.

    “Our training times are about 7-10 times faster, and our memory footprints are 2-4 times smaller than the best baseline performances of previously reported large-scale, distributed deep-learning systems,” said Shrivastava, an assistant professor of computer science at Rice.

    Medini, a Ph.D. student at Rice, said product search is challenging, in part, because of the sheer number of products. “There are about 1 million English words, for example, but there are easily more than 100 million products online.”

    There are also millions of people shopping for those products, each in their own way. Some type a question. Others use keywords. And many aren’t sure what they’re looking for when they start. But because millions of online searches are performed every day, tech companies like Amazon, Google and Microsoft have a lot of data on successful and unsuccessful searches. And using this data for a type of machine learning called deep learning is one of the most effective ways to give better results to users.

    2
    Beidi Chen and Tharun Medini, graduate students in computer science at Rice University. (Photo by Jeff Fitlow/Rice University)

    Deep learning systems, or neural network models, are vast collections of mathematical equations that take a set of numbers called input vectors, and transform them into a different set of numbers called output vectors. The networks are composed of matrices with several parameters, and state-of-the-art distributed deep learning systems contain billions of parameters that are divided into multiple layers. During training, data is fed to the first layer, vectors are transformed, and the outputs are fed to the next layer and so on.

    “Extreme classification problems” are ones with many possible outcomes, and thus, many parameters. Deep learning models for extreme classification are so large that they typically must be trained on what is effectively a supercomputer, a linked set of graphics processing units (GPU) where parameters are distributed and run in parallel, often for several days.

    “A neural network that takes search input and predicts from 100 million outputs, or products, will typically end up with about 2,000 parameters per product,” Medini said. “So you multiply those, and the final layer of the neural network is now 200 billion parameters. And I have not done anything sophisticated. I’m talking about a very, very dead simple neural network model.”

    “It would take about 500 gigabytes of memory to store those 200 billion parameters,” Medini said. “But if you look at current training algorithms, there’s a famous one called Adam that takes two more parameters for every parameter in the model, because it needs statistics from those parameters to monitor the training process. So, now we are at 200 billion times three, and I will need 1.5 terabytes of working memory just to store the model. I haven’t even gotten to the training data. The best GPUs out there have only 32 gigabytes of memory, so training such a model is prohibitive due to massive inter-GPU communication.”

    MACH takes a very different approach. Shrivastava describes it with a thought experiment randomly dividing the 100 million products into three classes, which take the form of buckets. “I’m mixing, let’s say, iPhones with chargers and T-shirts all in the same bucket,” he said. “It’s a drastic reduction from 100 million to three.”

    In the thought experiment, the 100 million products are randomly sorted into three buckets in two different worlds, which means that products can wind up in different buckets in each world. A classifier is trained to assign searches to the buckets rather than the products inside them, meaning the classifier only needs to map a search to one of three classes of product.

    “Now I feed a search to the classifier in world one, and it says bucket three, and I feed it to the classifier in world two, and it says bucket one,” he said. “What is this person thinking about? The most probable class is something that is common between these two buckets. If you look at the possible intersection of the buckets there are three in world one times three in world two, or nine possibilities,” he said. “So I have reduced my search space to one over nine, and I have only paid the cost of creating six classes.”

    Adding a third world, and three more buckets, increases the number of possible intersections by a factor of three. “There are now 27 possibilities for what this person is thinking,” he said. “So I have reduced my search space by one over 27, but I’ve only paid the cost for nine classes. I am paying a cost linearly, and I am getting an exponential improvement.”

    In their experiments with Amazon’s training database, Shrivastava, Medini and colleagues randomly divided the 49 million products into 10,000 classes, or buckets, and repeated the process 32 times. That reduced the number of parameters in the model from around 100 billion to 6.4 billion. And training the model took less time and less memory than some of the best reported training times on models with comparable parameters, including Google’s Sparsely-Gated Mixture-of-Experts (MoE) model, Medini said.

    He said MACH’s most significant feature is that it requires no communication between parallel processors. In the thought experiment, that is what’s represented by the separate, independent worlds.

    “They don’t even have to talk to each other,” Medini said. “In principle, you could train each of the 32 on one GPU, which is something you could never do with a nonindependent approach.”

    Shrivastava said, “In general, training has required communication across parameters, which means that all the processors that are running in parallel have to share information. Looking forward, communication is a huge issue in distributed deep learning. Google has expressed aspirations of training a 1 trillion parameter network, for example. MACH, currently, cannot be applied to use cases with small number of classes, but for extreme classification, it achieves the holy grail of zero communication.”

    Study co-authors include Vijai Mohan of Amazon Search and former Rice students Qixuan Huang and Yiqiu Wang.

    The research was supported by the National Science Foundation, the Air Force Office of Scientific Research, Amazon Research and the Office of Naval Research.

    See the full article here .


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


    Stem Education Coalition

    Rice U campus

    In his 1912 inaugural address, Rice University president Edgar Odell Lovett set forth an ambitious vision for a great research university in Houston, Texas; one dedicated to excellence across the range of human endeavor. With this bold beginning in mind, and with Rice’s centennial approaching, it is time to ask again what we aspire to in a dynamic and shrinking world in which education and the production of knowledge will play an even greater role. What shall our vision be for Rice as we prepare for its second century, and how ought we to advance over the next decade?

    This was the fundamental question posed in the Call to Conversation, a document released to the Rice community in summer 2005. The Call to Conversation asked us to reexamine many aspects of our enterprise, from our fundamental mission and aspirations to the manner in which we define and achieve excellence. It identified the pressures of a constantly changing and increasingly competitive landscape; it asked us to assess honestly Rice’s comparative strengths and weaknesses; and it called on us to define strategic priorities for the future, an effort that will be a focus of the next phase of this process.

     
  • richardmitnick 12:02 pm on December 7, 2019 Permalink | Reply
    Tags: "Gulf Coast corals face catastrophe", , , Rice University   

    From Rice University: “Gulf Coast corals face catastrophe” 

    Rice U bloc

    From Rice University

    December 5, 2019

    Jeff Falk
    713-348-6775
    jfalk@rice.edu

    Mike Williams
    713-348-6728
    mikewilliams@rice.edu

    Rice University-led study shows only rapid reduction of greenhouse gases will let banks thrive.

    If coral reefs are the canary to the ocean’s coal mine, it’s getting awfully bleak in the Gulf of Mexico.

    1
    Gulf of Mexico coral reefs may only be saved by a dramatic reduction in greenhouse gas emissions, according to Rice-led research. Here, members of co-author Kristine DeLong’s lab drill into coral reefs to extract samples on Dry Tortugas in the Florida Keys. Courtesy of Kristine DeLong, Louisiana State University

    A new study [Frontiers in Marine Science] by Rice University Earth scientists asserts: Without a rapid and dramatic reduction of greenhouse gas emissions, fragile coral reefs in the Gulf of Mexico, like those around the world, face catastrophe.

    That could be bad for us all, said Sylvia Dee, a Rice assistant professor of Earth, environmental and planetary sciences. She and colleagues from Rice, the University of Texas at Austin and Louisiana State University drew their evidence from an extensive analysis of stressors on corals that line the Gulf coast.

    They found the majority of shallow reefs along the coast from Texas to Florida are in poor-to-fair condition, and the predicted rise in surface temperatures and ocean acidity will severely degrade what’s left by the end of the century.

    The sheer speed of those changes will hamper, if not prevent, the recovery of reefs, some of which began to evolve in the gulf 420,000 years ago, Dee said.

    “Part of this paper addresses whether or not reefs are adaptable to the warming temperatures and increasingly acidic oceans,” said Dee, whose climate model projections were compared to years of data collected by the government and environmental scientists. “We looked for clues from periods in the past that might suggest present-day reefs have the ability to cope with heating and adapt or regenerate.

    “But there’s limited evidence to suggest that the adaptation could occur fast enough compared to how quickly we’re warming the oceans,” she said. “Millions of years ago, rates of sea surface temperature change and ocean acidification, such as those we’re experiencing now, would have happened over much longer time scales.”

    The team’s open-access study appears in an edition of Frontiers in Marine Science dedicated to the past, present and future of Gulf of Mexico reefs. The edition was inspired by an October 2018 Rice symposium on the topic organized by Adrienne Correa, an assistant professor of biosciences whose paper on gene expression of endangered coral also appears in the edition.

    Most research on climate change and coral reefs to date has focused on the Great Barrier Reef and the tropical Pacific, she said. “Things are going south at a rapid rate there,” Dee said. “But Gulf of Mexico reefs are also being swiftly degraded, and there hadn’t been a comprehensive paper looking at the gulf alone.”

    The researchers noted that coral reefs support the world’s fisheries, protect coastlines and promote tourism, generating billions of dollars for the global economy each year. According to one study [NOAA], they support more than 70,000 jobs in southeast Florida alone.

    2
    Corals and sponges in the Flower Garden Banks National Marine Sanctuary. According to research led by Rice University, Gulf of Mexico coral reefs may only be saved by a dramatic reduction in greenhouse gas emissions beyond those called for in the Paris Agreement. Courtesy of the National Ocean Service Image Gallery

    In line with recent, dramatic reports by the Intergovernmental Panel on Climate Change and the United Nations, the researchers found that even hitting the emission targets called for by the Paris Agreement, which aim to keep global temperatures from rising more than 1.5 degrees Celsius, may not be sufficient to preserve the reefs.

    Their climate model uses a benchmark known as Representative Concentration Pathways, which describes the future amount of radiative forcing, the balance between energy absorbed by the Earth from sunlight and that radiated back to space. The study assumed a forcing imbalance of +8.5 watts per square meter as the baseline for future warming. However, future greenhouse gas emissions have a direct impact on this number, which the researchers considered conservative, as it takes into account emissions measured over the past few decades.

    “We used, essentially, a worst-case scenario for how humans will behave,” Dee said. “But we explored both medium-range — or medium climate change abatement — and worst-case scenarios. Unfortunately, no matter the scenario, heating rates are high enough that we would expect almost complete coral bleaching throughout the Gulf of Mexico.”

    Coral bleaching refers to the expulsion of symbiotic algae that live inside coral tissues. Corals draw most of their energy from algae and begin to starve when it disappears due to rising temperatures. Sea life depends on the reef for shelter and sustenance and coral banks are a natural physical barrier that help protect coastlines by reducing erosion from wave action and storm surge.

    “The best-case scenario is that we have rapid and widespread reduction of greenhouse gas emissions in the near term, the next 20 years,” she said. “The corals in the Gulf of Mexico are hardy. Some survived Hurricane Mitch, and other gulf reefs have survived catastrophic, short-lived events. The concern is that if the heating gets worse every single year, it’s going to be close to impossible for the corals to bounce back.”

    Co-author Mark Torres, an assistant professor of Earth, environmental and planetary sciences at Rice, noted models showed the secondary effects of ocean acidification may not be as dire as rapid temperature rise, but would still challenge the reefs’ ability to recover.

    3
    Co-author Kristine DeLong and a colleague stand behind a fossilized coral reef boulder dating back to the last interglacial that washed ashore on Little Cayman. Courtesy of Kristine DeLong, Louisiana State University

    “Corals make their skeletons around calcium carbonate,” he said. “If seawater becomes so corrosive that skeletons dissolve in it, there’s no adapting around that.”

    “Think of it like putting a tooth in a Coke can,” Dee added.

    Corals thrive along a narrow range of coastal shelf, so their ability to migrate to more hospitable waters is limited, Torres said. “If they grow deeper, the water is colder, but then they’re further away from the light,” he said. “There are physical limits to how deep they can live.”

    The researchers noted corals could give way to other species, like sponges, over the long term, but can’t predict how that would impact the overall coral reef environment.

    “Corals are the foundation of ecosystem health for most marine species,” Dee said. “If the corals go away, you lose the fish, you lose everything. When we started evaluating climate model simulations for the future, we didn’t know that the conditions in the Gulf of Mexico were going to be so dire.”

    Co-authors of the paper are Rowan Martindale, an assistant professor of geosciences, and graduate student Anna Weiss of the University of Texas at Austin, and Kristine DeLong, an associate professor of geography and anthropology at Louisiana State University.

    The Department of the Interior South Central Climate Adaptation Science Center supported the research.

    See the full article here .


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


    Stem Education Coalition

    Rice U campus

    In his 1912 inaugural address, Rice University president Edgar Odell Lovett set forth an ambitious vision for a great research university in Houston, Texas; one dedicated to excellence across the range of human endeavor. With this bold beginning in mind, and with Rice’s centennial approaching, it is time to ask again what we aspire to in a dynamic and shrinking world in which education and the production of knowledge will play an even greater role. What shall our vision be for Rice as we prepare for its second century, and how ought we to advance over the next decade?

    This was the fundamental question posed in the Call to Conversation, a document released to the Rice community in summer 2005. The Call to Conversation asked us to reexamine many aspects of our enterprise, from our fundamental mission and aspirations to the manner in which we define and achieve excellence. It identified the pressures of a constantly changing and increasingly competitive landscape; it asked us to assess honestly Rice’s comparative strengths and weaknesses; and it called on us to define strategic priorities for the future, an effort that will be a focus of the next phase of this process.

     
  • richardmitnick 3:53 pm on December 2, 2019 Permalink | Reply
    Tags: "Mysterious Tectonic Fault Zone Detected Off The Coast of California", , Cables could monitor earthquakes across long stretches of land and sea., Recording underwater earthquakes., Researchers discovered a new fault system underwater., Rice University, ,   

    From UC Berkeley and Rice University via Science Alert: “Mysterious Tectonic Fault Zone Detected Off The Coast of California” 

    From UC Berkeley

    and

    Rice U bloc

    Rice University

    via

    ScienceAlert

    Science Alert

    2 DEC 2019
    ARIA BENDIX

    1
    Monterey Bay. (N.J. Lindsey)

    Nearly 3,000 feet (900 metres) below the surface of Monterey Bay, a network of deep sea cables helps scientists to study marine life.

    Spanning 32 miles (51 kilometres) across the floor of the Pacific Ocean, the cables record sounds like the high-pitched squeal of a dolphin or the deep moans of a humpback whale. They also capture the emission of light from undersea organisms like poisonous algae.

    But a team of researchers from Rice University and the University of California, Berkeley, have discovered another use for the network: recording underwater earthquakes.

    Last year, the researchers conducted a four-day experiment using 12 miles (19 kilometres) of the cable network to study the motion of the seafloor. The results of that experiment appear in a new paper in the journal Science published on November 28.

    2
    Deep sea cables that connect the internet. (TeleGeography)

    The researchers reveal that they detected a 3.5-magnitude earthquake in Gilroy, a city in Northern California, in March 2018. They also discovered a new fault system at the bottom of the ocean. The technology could eventually help them map fault lines in areas where scientists know very little about seismic activity on the ocean floor.

    “It’s kind of like streetlamps shining light on an area of the seafloor,” Nate Lindsey, the paper’s lead author, told Business Insider. “There’s a lot of potential to go and do this in an area where it makes a difference.”

    Researchers discovered a new fault system underwater

    Before the researchers conducted their experiment at sea, they tested their technology on land using underground fibre-optic cables from the US Department of Energy, which funded the project. The cables stretch 13,000 miles (20,000 kilometres) below ground in Sacramento, California, but the researchers only used 14 miles for their experiment.

    To start, they attached a device to the end of the cables that shoots out bursts of light. When the ground moves, it places a strain on the cables that scatters the light and sends it hurtling back toward the device. These light waves can be measured to determine the magnitude of an earthquake.

    After six months of experimenting on land, the researchers moved their technology underwater. They partnered with the Monterey Accelerated Research System (MARS), which operates a network of undersea fibre-optic cables.

    Every year, the cables need to be taken offline for maintenance, giving the researchers a brief window to test their technology.

    For their experiment, the researchers used a portion of the cables that stretches from Moss Landing, a small fishing village off the coast of Monterey Bay, to Soquel Canyon, an offshore marine protected area.

    3
    MARS cable in Monterey Bay with pink portion used for sensing. (Lindsey et al., Science, 2019)

    By installing their device at the end of the undersea cables, the researchers were able to monitor shifts and fractures at the bottom of the ocean. This led to the discovery of a new underwater fault system in the Pacific Ocean in-between two major fault lines, the San Gregorio and the San Andreas, which run parallel to each other.

    Lindsey said the fault system is likely “much, much smaller” and “minor” compared to the San Andreas – which scientists have pinpointed as the likely source of the next major California earthquake.

    But he said his technology could ultimately be used to identify larger fault lines in unexplored areas like offshore Taiwan.

    Cables could monitor earthquakes across long stretches of land and sea.

    Since most of Earth’s surface – around 70 percent – is covered in water, scientists don’t have many ways to measure offshore earthquakes.

    Jonathan Ajo-Franklin, a geophysics professor at Rice University who worked on the experiment, said systems like the one from MARS – which are tethered to the shore by a cable – are so rare that you could count them on one hand. He estimated that just three or four operate at one time on the West Coast.

    “In every case, it’s limited scope in terms of the length of the experiment and it’s high cost,” Lindsey said. The MARS observatory, for instance, cost around US$13.5 million.

    4
    Monterey Accelerated Research System’s underwater observatory. (MBARI, 2009)

    But Lindsey still thinks cable networks are the best way to study underwater seismic activity. Other ocean researchers share his enthusiasm.

    John Collins, a senior researcher at the Woods Hole Oceanographic Institution who didn’t work on the study, called the technique “very promising”. Bruce Howe, a physical oceanographer at the University of Hawaii, also thought the system could provide useful data.

    “It’s based on good physics, so I think it will pan out,” Howe, who also wasn’t involved in the study, told Business Insider.

    On land, traditional earthquake sensors typically measure the speed of the ground motion at a single point. But fibre-optic cables allow researchers to take multiple measurements across a long path.

    “For every metre of cable, you’re measuring a stretch of tens of nanometres or even smaller,” Ajo-Franklin said. That’s about the width of a human hair.

    The MARS system, for instance, can record measurements at 10,000 locations, meaning it has the same capacity as 10,000 individual motion sensors. That gives researchers lots of data points for studying how earthquakes rattle across the ocean.

    When the 3.5-magnitude earthquake struck Gilroy last year, the researchers were able to record the tremors of the ocean waves – a tool that might eventually help with the early detection of tsunamis.

    “The nice thing about recording that earthquake was not necessarily locating it,” Ajo-Franklin said.

    “When you have densely sampled locations, you can do a lot more with the earthquake’s wavefield to allow you to build pictures of what’s on the ground.”

    See the full article here .

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Rice U campus

    In his 1912 inaugural address, Rice University president Edgar Odell Lovett set forth an ambitious vision for a great research university in Houston, Texas; one dedicated to excellence across the range of human endeavor. With this bold beginning in mind, and with Rice’s centennial approaching, it is time to ask again what we aspire to in a dynamic and shrinking world in which education and the production of knowledge will play an even greater role. What shall our vision be for Rice as we prepare for its second century, and how ought we to advance over the next decade?

    This was the fundamental question posed in the Call to Conversation, a document released to the Rice community in summer 2005. The Call to Conversation asked us to reexamine many aspects of our enterprise, from our fundamental mission and aspirations to the manner in which we define and achieve excellence. It identified the pressures of a constantly changing and increasingly competitive landscape; it asked us to assess honestly Rice’s comparative strengths and weaknesses; and it called on us to define strategic priorities for the future, an effort that will be a focus of the next phase of this process.

    Founded in the wake of the gold rush by leaders of the newly established 31st state, the University of California’s flagship campus at Berkeley has become one of the preeminent universities in the world. Its early guiding lights, charged with providing education (both “practical” and “classical”) for the state’s people, gradually established a distinguished faculty (with 22 Nobel laureates to date), a stellar research library, and more than 350 academic programs.

    UC Berkeley Seal

     
  • richardmitnick 11:30 am on September 18, 2019 Permalink | Reply
    Tags: Christopher Tunnell, Large astroparticle data sets contain the faintest signals that anyone has ever attempted to measure., Reimagining data science techniques and helping push data-intensive physical sciences past the tipping point to discovery., Rice University, Supporting these physical science communities through a “domain-enhanced” data science institute., Using machine and deep learning in bioinformatics; computational biology; materials science; and environmental sciences.   

    From Rice University: “Deep dive for dark matter may aid all of data science” 

    Rice U bloc

    From Rice University

    September 18, 2019
    Mike Williams

    National Science Foundation backs Rice-led effort to create science-aware artificial intelligence.

    A Rice University scientist and his colleagues are booting their search for dark matter into a study they hope will enhance all of data science.

    Rice astroparticle physicist Christopher Tunnell and his team have received a $1 million National Science Foundation (NSF) grant to reimagine data science techniques and help push data-intensive physical sciences past the tipping point to discovery.

    1
    Christopher Tunnell (Credit: Jeff Fitlow/Rice University)

    Experiments in the physical sciences are starting to produce thousands of terabytes of data, Tunnell said. “These datasets are fundamentally different from large datasets of everyday photos, text or video,” he said. “Ours relate to experiences of the natural world that only highly specialized instruments and sensors can ‘see.’”

    In tackling this class of problem, the two-year project aims to influence the way data scientists use machine and deep learning in bioinformatics, computational biology, materials science and environmental sciences. Tunnell said the goal is to support these physical science communities through a “domain-enhanced” data science institute.

    “In large astroparticle data sets, we often look for the faintest signals that anyone has ever attempted to measure,” said Tunnell, an assistant professor of physics and astronomy and computer science and lead investigator on the project.

    “Science is incremental,” he said, explaining the domain-enhanced approach. “We have spent decades building up mankind’s most precise physical theories, which provide the foundation for these measurements. When using machine learning in this realm, the machine has to learn through its own ‘Phys 101.’ But the great artificial intelligence advancements of the last decade have been mostly in computer vision and natural language processing with a muted impact in physical sciences.”

    Tunnell’s co-investigators are Waheed Bajwa, an associate professor of electrical and computer engineering at Rutgers University, and Hagit Shatkay, a professor of computer and information sciences at the University of Delaware. The team formed at an Ideas Lab run by the NSF and Knowinnovation that brought together scientists and engineers to facilitate novel data science ideas that did not fit any disciplinary mold.

    The researchers argue that particle physics can serve as a driver for technological advances that are later used by other sciences in the same way that data-handling needs at the European Organization for Nuclear Research (known as CERN) led to the development of the World Wide Web.

    “Our proposal focuses on one scientific application — in this case astroparticle physics — to test out multiple novel methods,” Tunnell said. “We are searching for solutions to a real-world problem rather than problems that fit our solution. That, in my view, is what interdisciplinary science is about.”

    For the dark matter search, they need data science and machine-learning algorithms that improve measurements of particle interactions in their detectors. “This will simultaneously increase the ability to measure faint dark-matter signals while improving the precision of energy measurements,” Tunnell said. “It will help the experiment be sensitive to neutrinoless double-beta decay, a process that sheds light on the nature of neutrino mass and, potentially, why our universe is made of matter.”

    He said they will employ probabilistic graphical models that allow them to encode their knowledge of science, as well as inverse problem formulations that teach machine-learning routines enough that they can learn the rest on their own.

    Tunnell has already gained a foothold in the search for dark matter, even if the matter itself is not at hand. Earlier this year, he and colleagues at the XENON1T experiment announced in Nature they had found the first physical evidence of the material with the longest half-life ever measured.

    XENON1T at Gran Sasso LABORATORI NAZIONALI del GRAN SASSO, located in the Abruzzo region of central Italy

    Gran Sasso LABORATORI NAZIONALI del GRAN SASSO, located in the Abruzzo region of central Italy

    The sophisticated detector under a mountain in Italy discovered that Xenon 124 has a half-life of 18 sextillion years, demonstrating that the experiment and subsequent data science can measure exotic physical signals.

    He noted the grant incorporates funds for educational outreach and training of data scientists in the techniques under development.

    Tunnell’s group was formed as part of Rice’s Data Science Initiative, with additional seed funding for research from two Rice Creative Ventures grants. “This work has already led to one discovery: a strong friendly interdisciplinary team interested in trying something new,” he said.

    See the full article here .


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


    Stem Education Coalition

    Rice U campus

    In his 1912 inaugural address, Rice University president Edgar Odell Lovett set forth an ambitious vision for a great research university in Houston, Texas; one dedicated to excellence across the range of human endeavor. With this bold beginning in mind, and with Rice’s centennial approaching, it is time to ask again what we aspire to in a dynamic and shrinking world in which education and the production of knowledge will play an even greater role. What shall our vision be for Rice as we prepare for its second century, and how ought we to advance over the next decade?

    This was the fundamental question posed in the Call to Conversation, a document released to the Rice community in summer 2005. The Call to Conversation asked us to reexamine many aspects of our enterprise, from our fundamental mission and aspirations to the manner in which we define and achieve excellence. It identified the pressures of a constantly changing and increasingly competitive landscape; it asked us to assess honestly Rice’s comparative strengths and weaknesses; and it called on us to define strategic priorities for the future, an effort that will be a focus of the next phase of this process.

     
  • richardmitnick 11:52 am on September 5, 2019 Permalink | Reply
    Tags: "Rice reactor turns greenhouse gas into pure liquid fuel", A common greenhouse gas could be repurposed in an efficient and environmentally friendly way with an electrolyzer that uses renewable electricity to produce pure liquid fuels., , “X-ray absorption spectroscopyenables us to probe the electronic structure of electrocatalysts in operando — that is during the actual chemical process.", , , Formic acid is an energy carrier. It’s a fuel-cell fuel that can generate electricity and emit carbon dioxide — which you can grab and recycle again., Formic acid produced by traditional carbon dioxide devices needs costly and energy-intensive purification steps Wang said., https://www.nature.com/articles/s41560-019-0451-x, In its latest prototype produces highly purified and high concentrations of formic acid., , Rice University, The catalytic reactor developed by the Rice University lab of chemical and biomolecular engineer Haotian Wang uses carbon dioxide as its feedstock., The direct production of pure formic acid solutions will help to promote commercial carbon dioxide conversion technologies., The first was his development of a robust two-dimensional bismuth catalyst and the second a solid-state electrolyte that eliminates the need for salt as part of the reaction., The method is detailed in Nature Energy, The Rice lab worked with Brookhaven National Laboratory to view the process in progress., Two advances made the new device possible said lead author and Rice postdoctoral researcher Chuan Xia.   

    From Rice University: “Rice reactor turns greenhouse gas into pure liquid fuel” 

    Rice U bloc

    From Rice University

    September 3, 2019
    Mike Williams
    713-348-6728
    mikewilliams@rice.edu

    Lab’s ‘green’ invention reduces carbon dioxide into valuable fuels.

    1
    Rice postdoctoral researcher Chuan Xia, left, and chemical and biomolecular engineer Haotian Wang adjust their electrocatalysis reactor to produce liquid formic acid from carbon dioxide. Photo by Jeff Fitlow

    A common greenhouse gas could be repurposed in an efficient and environmentally friendly way with an electrolyzer that uses renewable electricity to produce pure liquid fuels.

    The catalytic reactor developed by the Rice University lab of chemical and biomolecular engineer Haotian Wang uses carbon dioxide as its feedstock and, in its latest prototype, produces highly purified and high concentrations of formic acid.

    Formic acid produced by traditional carbon dioxide devices needs costly and energy-intensive purification steps, Wang said. The direct production of pure formic acid solutions will help to promote commercial carbon dioxide conversion technologies.

    The method is detailed in Nature Energy.

    Wang, who joined Rice’s Brown School of Engineering in January, and his group pursue technologies that turn greenhouse gases into useful products. In tests, the new electrocatalyst reached an energy conversion efficiency of about 42%. That means nearly half of the electrical energy can be stored in formic acid as liquid fuel.

    “Formic acid is an energy carrier,” Wang said. “It’s a fuel-cell fuel that can generate electricity and emit carbon dioxide — which you can grab and recycle again.

    “It’s also fundamental in the chemical engineering industry as a feedstock for other chemicals, and a storage material for hydrogen that can hold nearly 1,000 times the energy of the same volume of hydrogen gas, which is difficult to compress,” he said. “That’s currently a big challenge for hydrogen fuel-cell cars.”

    2
    This schematic shows the electrolyzer developed at Rice to reduce carbon dioxide, a greenhouse gas, to valuable fuels. At left is a catalyst that selects for carbon dioxide and reduces it to a negatively charged formate, which is pulled through a gas diffusion layer (GDL) and the anion exchange membrane (AEM) into the central electrolyte. At the right, an oxygen evolution reaction (OER) catalyst generates positive protons from water and sends them through the cation exchange membrane (CEM). The ions recombine into formic acid or other products that are carried out of the system by deionized (DI) water and gas. Illustration by Chuan Xia and Demin Liu.

    Two advances made the new device possible, said lead author and Rice postdoctoral researcher Chuan Xia. The first was his development of a robust, two-dimensional bismuth catalyst and the second a solid-state electrolyte that eliminates the need for salt as part of the reaction.

    “Bismuth is a very heavy atom, compared to transition metals like copper, iron or cobalt,” Wang said. “Its mobility is much lower, particularly under reaction conditions. So that stabilizes the catalyst.” He noted the reactor is structured to keep water from contacting the catalyst, which also helps preserve it.

    Xia can make the nanomaterials in bulk. “Currently, people produce catalysts on the milligram or gram scales,” he said. “We developed a way to produce them at the kilogram scale. That will make our process easier to scale up for industry.”

    3
    Rice postdoctoral researcher Chuan Xia, left, and chemical and biomolecular engineer Haotian Wang. Photo by Jeff Fitlow

    The polymer-based solid electrolyte is coated with sulfonic acid ligands to conduct positive charge or amino functional groups to conduct negative ions. “Usually people reduce carbon dioxide in a traditional liquid electrolyte like salty water,” Wang said. “You want the electricity to be conducted, but pure water electrolyte is too resistant. You need to add salts like sodium chloride or potassium bicarbonate so that ions can move freely in water.

    “But when you generate formic acid that way, it mixes with the salts,” he said. “For a majority of applications you have to remove the salts from the end product, which takes a lot of energy and cost. So we employed solid electrolytes that conduct protons and can be made of insoluble polymers or inorganic compounds, eliminating the need for salts.”

    The rate at which water flows through the product chamber determines the concentration of the solution. Slow throughput with the current setup produces a solution that is nearly 30% formic acid by weight, while faster flows allow the concentration to be customized. The researchers expect to achieve higher concentrations from next-generation reactors that accept gas flow to bring out pure formic acid vapors.

    The Rice lab worked with Brookhaven National Laboratory to view the process in progress. “X-ray absorption spectroscopy, a powerful technique available at the Inner Shell Spectroscopy (ISS) beamline at Brookhaven Lab’s National Synchrotron Light Source II, enables us to probe the electronic structure of electrocatalysts in operando — that is, during the actual chemical process,” said co-author Eli Stavitski, lead beamline scientist at ISS. “In this work, we followed bismuth’s oxidation states at different potentials and were able to identify the catalyst’s active state during carbon dioxide reduction.”


    BNL NSLS II

    With its current reactor, the lab generated formic acid continuously for 100 hours with negligible degradation of the reactor’s components, including the nanoscale catalysts. Wang suggested the reactor could be easily retooled to produce such higher-value products as acetic acid, ethanol or propanol fuels.

    4
    An electrocatalysis reactor built at Rice recycles carbon dioxide to produce pure liquid fuel solutions using electricity. The scientists behind the invention hope it will become an efficient and profitable way to reuse the greenhouse gas and keep it out of the atmosphere. Photo by Jeff Fitlow

    “The big picture is that carbon dioxide reduction is very important for its effect on global warming as well as for green chemical synthesis,” Wang said. “If the electricity comes from renewable sources like the sun or wind, we can create a loop that turns carbon dioxide into something important without emitting more of it.”

    Co-authors are Rice graduate student Peng Zhu; graduate student Qiu Jiang and Husam Alshareef, a professor of material science and engineering, at King Abdullah University of Science and Technology, Saudi Arabia (KAUST); postdoctoral researcher Ying Pan of Harvard University; and staff scientist Wentao Liang of Northeastern University. Wang is the William Marsh Rice Trustee Assistant Professor of Chemical and Biomolecular Engineering. Xia is a J. Evans Attwell-Welch Postdoctoral Fellow at Rice.

    Rice and the U.S. Department of Energy Office of Science User Facilities supported the research.

    5
    Eli Stavitski, lead scientist at the Inner Shell Spectroscopy (ISS) beamline at Brookhaven National Laboratory’s National Synchrotron Light Source II, used the powerful tool to probe bismuth’s oxidation states, part of the process developed at Rice University to recycle carbon dioxide to produce pure liquid fuel solutions using electricity. (Credit: Brookhaven National Laboratory)

    See the full article here .


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


    Stem Education Coalition

    Rice U campus

    In his 1912 inaugural address, Rice University president Edgar Odell Lovett set forth an ambitious vision for a great research university in Houston, Texas; one dedicated to excellence across the range of human endeavor. With this bold beginning in mind, and with Rice’s centennial approaching, it is time to ask again what we aspire to in a dynamic and shrinking world in which education and the production of knowledge will play an even greater role. What shall our vision be for Rice as we prepare for its second century, and how ought we to advance over the next decade?

    This was the fundamental question posed in the Call to Conversation, a document released to the Rice community in summer 2005. The Call to Conversation asked us to reexamine many aspects of our enterprise, from our fundamental mission and aspirations to the manner in which we define and achieve excellence. It identified the pressures of a constantly changing and increasingly competitive landscape; it asked us to assess honestly Rice’s comparative strengths and weaknesses; and it called on us to define strategic priorities for the future, an effort that will be a focus of the next phase of this process.

     
  • richardmitnick 12:53 pm on August 31, 2019 Permalink | Reply
    Tags: "The ‘universal break-up criterion’ of hot flowing lava", , Lava fountains at Kilauea in Hawaii created a spatter cone which was estimated to be 180 feet tall., Low-viscosity lava is the red-hot flowing type one might see at Hawaii’s famed Kilauea volcano., Rice University, Tool lets scientists examine changing behavior of low-viscosity lava.,   

    From Rice University: “The ‘universal break-up criterion’ of hot, flowing lava” 

    Rice U bloc

    From Rice University

    August 30, 2019
    Jade Boyd

    Tool lets scientists examine changing behavior of low-viscosity lava.

    1
    Thomas Jones is a Rice Academy Postdoctoral Fellow in Rice University’s Department of Earth, Environmental and Planetary Sciences. (Photo courtesy of T. Jones)

    Thomas Jones’ “universal break-up criterion” won’t help with meltdowns of the heart, but it will help volcanologists study changing lava conditions in common volcanic eruptions.

    Jones, of Rice University, studies the behavior of low-viscosity lava, the runny kind that’s found at most volcanoes. About two years ago, he began a series of lab experiments and field observations that provided the raw inputs for a new fluid dynamic model of lava break-up. The work is described in a paper in Nature Communications.

    Low-viscosity lava is the red-hot, flowing type one might see at Hawaii’s famed Kilauea volcano, and Jones said it usually behaves in one of two ways.

    3
    Lava fountains at Kilauea in Hawaii created a spatter cone, which was estimated to be 180 feet tall in this June 2018 photo. (Image courtesy of U.S. Geological Survey)

    “It can bubble or spew out, breaking into chunks that spatter about the vent, or it can flow smoothly, forming lava streams that can rapidly move downhill,” he said.

    But that behavior can sometimes change quickly during the course of an eruption, and so can the associated dangers: While spattering eruptions throw hot lava fragments into the air, lava flows can threaten to destroy whole neighborhoods and towns.

    Jones’ model, the first of its kind, allows scientists to calculate when an eruption will transition from a spattering spray to a flowing stream, based upon the liquid properties of the lava itself and the eruption conditions at the vent.

    Jones said additional work is needed to refine the tool, and he looks forward to doing some of it himself.

    “We will validate this by going to an active volcano, taking some high-speed videos and seeing when things break apart and under what conditions,” he said. “We also plan to look at the effect of adding bubbles and crystals, because real magmas aren’t as simple as the idealized liquid in our mathematical model. Real magmas can also have bubbles and crystals in them. I’m sure those will change things. We want to find out how.”

    Jones said pairing the new model with real-time information about a lava’s liquid properties and eruption conditions could allow emergency officials to predict when an eruption will change style and become a hazard to at-risk communities.

    4
    Lava from a fountain on Hawaii’s Kilauea volcano flows over a spillway into an established channel in June 2018. (Image courtesy of U.S. Geological Survey)

    “We want to use this as a forecasting tool for eruption behavior,” he said. “By developing a model of what’s happening in the subsurface we can then watch for indications that it’s about to cross the tipping point and change behavior.”

    The study was co-authored by C.D. Reynolds of the University of Birmingham in the United Kingdom and S.C. Boothroyd of Durham University, also in the UK. The research was supported by the UK’s National Environment Research Council and Rice University.

    See the full article here .


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


    Stem Education Coalition

    Rice U campus

    In his 1912 inaugural address, Rice University president Edgar Odell Lovett set forth an ambitious vision for a great research university in Houston, Texas; one dedicated to excellence across the range of human endeavor. With this bold beginning in mind, and with Rice’s centennial approaching, it is time to ask again what we aspire to in a dynamic and shrinking world in which education and the production of knowledge will play an even greater role. What shall our vision be for Rice as we prepare for its second century, and how ought we to advance over the next decade?

    This was the fundamental question posed in the Call to Conversation, a document released to the Rice community in summer 2005. The Call to Conversation asked us to reexamine many aspects of our enterprise, from our fundamental mission and aspirations to the manner in which we define and achieve excellence. It identified the pressures of a constantly changing and increasingly competitive landscape; it asked us to assess honestly Rice’s comparative strengths and weaknesses; and it called on us to define strategic priorities for the future, an effort that will be a focus of the next phase of this process.

     
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