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  • richardmitnick 12:19 pm on September 29, 2020 Permalink | Reply
    Tags: "Astrophysicist probes cosmic 'dark matter detector'", , , , , Magnetar PSR J1745-2900, phys.org, ,   

    From University of Colorado Boulder via phys.org: “Astrophysicist probes cosmic ‘dark matter detector'” 

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    From University of Colorado Boulder

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    From phys.org

    September 29, 2020
    Daniel Strain, University of Colorado at Boulder

    1
    The middle of the Milky Way Galaxy showing the location of the supermassive black hole at its center, called Sagittarius A*, and the nearby magnetar PSR J1745-2900. Credits: NASA/CXC/FIT/E

    A University of Colorado Boulder astrophysicist is searching the light coming from a distant, and extremely powerful celestial object, for what may be the most elusive substance in the universe: Dark Matter.

    In two recent studies, Jeremy Darling, a professor in the Department of Astrophysical and Planetary Sciences, has taken a deep look at PSR J1745-2900. This body is a magnetar, or a type of collapsed star that generates an incredibly strong magnetic field.

    “It’s the best natural dark matter detector we know about,” said Darling, also of the Center for Astrophysics and Space Astronomy (CASA) at CU Boulder.

    He explained that dark matter is a sort of cosmic glue—an as-of-yet unidentified particle that makes up roughly 27% of the mass of the universe and helps to bind together galaxies like our own Milky Way. To date, scientists have mostly led the hunt for this invisible matter using laboratory equipment.

    Darling has taken a different approach in his latest research: Drawing on telescope data, he’s peering at PSR J1745-2900 to see if he can detect the faint signals of one candidate for dark matter—a particle called the axion—transforming into light. So far, the scientist’s search has come up empty. But his results could help physicists working in labs around the world to narrow down their own hunts for the axion.

    The new studies are also a reminder that researchers can still look to the skies to solve some of the toughest questions in science, Darling said. He published his first round of results this month in the Astrophysical Journal Letters and Physical Review Letters.

    “In astrophysics, we find all of these interesting problems like dark matter and dark energy, then we step back and let physicists solve them,” he said. “It’s a shame.”

    Natural experiment

    Darling wants to change that—in this case, with a little help from PSR J1745-2900.

    This magnetar orbits the supermassive black hole at the center of the Milky Way Galaxy from a distance of less than a light-year away. And it’s a force of nature: PSR J1745-2900 generates a magnetic field that is roughly a billion times more powerful than the most powerful magnet on Earth.

    “Magnetars have all of the magnetic field that a star has, but it’s been crunched down into an area about 20 kilometers across,” Darling said.

    And it’s where Darling has gone fishing for dark matter.

    He explained that scientists have yet to locate a single axion, a theoretical particle first proposed in the 1970s. Physicists, however, predict that these ephemeral bits of matter may have been created in monumental numbers during the early life of the universe—and in large enough quantities to explain the cosmos’ extra mass from dark matter. According to theory, axions are billions or even trillions of times lighter than electrons and would interact only rarely with their surroundings.

    That makes them almost impossible to observe, with one big exception: If an axion passes through a strong magnetic field, it can transform into light that researchers could, theoretically, detect.

    Scientists, including a team at JILA on the CU Boulder campus, have used lab-generated magnetic fields to try to capture that transition in action. Darling and other scientists had a different idea: Why not try the same search but on a much bigger scale?

    “Magnetars are the most magnetic objects we know of in the universe,” he said. “There’s no way we could get close to that strength in the lab.”

    Narrowing in

    To make use of that natural magnetic field, Darling drew on observations of PSR J1745-2900 taken by the Karl G. Jansky Very Large Array, an observatory in New Mexico.

    NRAO Karl G Jansky Very Large Array, located in central New Mexico on the Plains of San Agustin, between the towns of Magdalena and Datil, ~50 miles (80 km) west of Socorro. The VLA comprises twenty-eight 25-meter radio telescopes.

    If the magnetar was, indeed, transforming axions into light, that metamorphosis might show up in the radiation emerging from the collapsed star.

    The effort is a bit like looking for a single needle in a really, really big haystack. Darling said that while theorists have put limits on how heavy axions might be, these particles could still have a wide range of possible masses. Each of those masses, in turn, would produce light with a specific wavelength, almost like a fingerprint left behind by dark matter.

    Darling hasn’t yet spotted any of those distinct wavelengths in the light coming from the magnetar. But he has been able to use the observations to probe the possible existence of axions across the widest range of masses yet—not bad for his first attempt. He added that such surveys can complement the work happening in Earth-based experiments.

    Konrad Lehnert agreed. He’s part of an experiment led by Yale University—called, not surprisingly, HAYSTAC—that is seeking out axions using magnetic fields created in labs across the country.

    Lehnert explained that astrophysical studies like Darling’s could act as a sort of scout in the hunt for axions—identifying interesting signals in the light of magnetars, which laboratory researchers could then dig into with much greater precision.

    “These well-controlled experiments would be able to sort out which of the astrophysical signals might have a dark matter origin,” said Lehnert, a fellow at JILA, a joint research institute between CU Boulder and the National Institute of Standards and Technology (NIST).

    Darling plans to continue his own search, which means looking even closer at the magnetar at the center of our galaxy: “We need to fill in those gaps and go even deeper.”

    Dark Matter Background
    Fritz Zwicky discovered Dark Matter in the 1930s when observing the movement of the Coma Cluster., Vera Rubin a Woman in STEM denied the Nobel, did most of the work on Dark Matter.

    Fritz Zwicky from http:// palomarskies.blogspot.com.

    Coma cluster via NASA/ESA Hubble.

    In modern times, it was astronomer Fritz Zwicky, in the 1930s, who made the first observations of what we now call dark matter. His 1933 observations of the Coma Cluster of galaxies seemed to indicated it has a mass 500 times more than that previously calculated by Edwin Hubble. Furthermore, this extra mass seemed to be completely invisible. Although Zwicky’s observations were initially met with much skepticism, they were later confirmed by other groups of astronomers.

    Thirty years later, astronomer Vera Rubin provided a huge piece of evidence for the existence of dark matter. She discovered that the centers of galaxies rotate at the same speed as their extremities, whereas, of course, they should rotate faster. Think of a vinyl LP on a record deck: its center rotates faster than its edge. That’s what logic dictates we should see in galaxies too. But we do not. The only way to explain this is if the whole galaxy is only the center of some much larger structure, as if it is only the label on the LP so to speak, causing the galaxy to have a consistent rotation speed from center to edge.

    Vera Rubin, following Zwicky, postulated that the missing structure in galaxies is dark matter. Her ideas were met with much resistance from the astronomical community, but her observations have been confirmed and are seen today as pivotal proof of the existence of dark matter.

    Astronomer Vera Rubin at the Lowell Observatory in 1965, worked on Dark Matter (The Carnegie Institution for Science).


    Vera Rubin measuring spectra, worked on Dark Matter (Emilio Segre Visual Archives AIP SPL).


    Vera Rubin, with Department of Terrestrial Magnetism (DTM) image tube spectrograph attached to the Kitt Peak 84-inch telescope, 1970. https://home.dtm.ciw.edu.

    The Vera C. Rubin Observatory currently under construction on the El Peñón peak at Cerro Pachón Chile, a 2,682-meter-high mountain in Coquimbo Region, in northern Chile, alongside the existing Gemini South and Southern Astrophysical Research Telescopes.

    LSST Data Journey, Illustration by Sandbox Studio, Chicago with Ana Kova.

    See the full article here.

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    U Colorado Campus

    As the flagship university of the state of Colorado CU-Boulder is a dynamic community of scholars and learners situated on one of the most spectacular college campuses in the country. As one of 34 U.S. public institutions belonging to the prestigious Association of American Universities (AAU) – and the only member in the Rocky Mountain region – we have a proud tradition of academic excellence, with five Nobel laureates and more than 50 members of prestigious academic academies.

    CU-Boulder has blossomed in size and quality since we opened our doors in 1877 – attracting superb faculty, staff, and students and building strong programs in the sciences, engineering, business, law, arts, humanities, education, music, and many other disciplines.

    Today, with our sights set on becoming the standard for the great comprehensive public research universities of the new century, we strive to serve the people of Colorado and to engage with the world through excellence in our teaching, research, creative work, and service.

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

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

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    From University of Michigan

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    From phys.org

    September 29, 2020

    1
    Credit: CC0 Public Domain

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

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

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

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

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

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

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

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

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

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

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

    See the full article here .


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    U MIchigan Campus

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

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

     
  • richardmitnick 11:05 am on September 28, 2020 Permalink | Reply
    Tags: "The testimony of trees: How volcanic eruptions shaped 2000 years of world history", , , phys.org, ,   

    From University of Cambridge via phys.org- “The testimony of trees: How volcanic eruptions shaped 2000 years of world history” 

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    From University of Cambridge

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    phys.org

    September 28, 2020
    Sarah Collins, University of Cambridge

    1
    Driftwood in Siberia. Credit: University of Cambridge.

    Researchers have shown that over the past two thousand years, volcanoes have played a larger role in natural temperature variability than previously thought, and their climatic effects may have contributed to past societal and economic change.

    The researchers, led by the University of Cambridge, used samples from more than 9000 living and dead trees to obtain a precise yearly record of summer temperatures in North America and Eurasia, dating back to the year 1 CE. This revealed colder and warmer periods that they then compared with records for very large volcanic eruptions as well as major historical events.

    Crucial to the accuracy of the dataset was the use of the same number of data points across the entire 2000 years. Previous reconstructions of climate over this extended period have been biased by over-representation of trees from more recent times.

    The results, reported in the journal Dendrochronologia, show that the effect of volcanoes on global temperature changes is even greater than had been recognised, although the researchers stress that their work in no way diminishes the significance of human-caused climate change.

    Instead, the researchers say, the study contributes to our understanding of the natural causes and societal consequences of summer temperature changes over the past two thousand years.

    “There is so much we can determine about past climate conditions from the information in tree rings, but we have far more information from newer trees than we do for trees which lived a thousand years or more ago,” said Professor Ulf Büntgen from Cambridge’s Department of Geography, the study’s lead author. “Removing some of the data from the more recent past levels the playing field for the whole 2000-year period we’re looking at, so in the end, we gain a more accurate understanding of natural versus anthropogenic climate change.”

    Comparing the data from tree rings against evidence from ice cores, the researchers were able to identify the effect of past volcanic eruptions on summer temperatures.

    Large volcanic eruptions can lower global average temperatures by fractions of a degree Celsius, with strongest effects in parts of North America and Eurasia. The main factor is the amount of sulphur emitted during the eruption that reaches the stratosphere, where it forms minute particles that block some sunlight from reaching the surface. This can result in shorter growing seasons and cooler temperatures, that lead in turn to reduced harvests. Conversely, in periods when fewer large eruptions occurred, the Earth is able to absorb more heat from the Sun and temperatures rise.

    “Some climate models assume that the effect of volcanoes is punctuated and short,” said Büntgen. “However, if you look at the cumulative effect over a whole century, this effect can be much longer. In part, we can explain warm conditions during the 3rd, 10th and 11th centuries through a comparative lack of eruptions.”

    Reconstructed summer temperatures in the 280s, 990s and 1020s, when volcanic forcing was low, were comparable to modern conditions until 2010.

    Compared with existing large-scale temperature reconstructions of the past 1200-2000 years, the study reveals a greater pre-industrial summer temperature variability, including strong evidence for the Late Antique Little Ice Age (LALIA) in the 6th and 7th centuries.

    Then, working with historians, the scientists found that relatively constant warmth during Roman and medieval periods, when large volcanic eruptions were less frequent, often coincided with societal prosperity and political stability in Europe and China. However, the periods characterised by more prolific volcanism often coincided with times of conflict and economic decline.

    “Interpreting history is always challenging,” said Dr. Clive Oppenheimer, the lead volcanologist of the study. “So many factors come into play—politics, economics, culture. But a big eruption that leads to widespread declines in grain production can hurt millions of people. Hunger can lead to famine, disease, conflict and migration. We see much evidence of this in the historical record.

    “We knew that large eruptions could have these effects, especially when societies were already stressed, but I was surprised to see the opposite effect so clearly in our data—that centuries with rather few eruptions had warmer summers than the long-term average.”

    The new temperature reconstructions provide deeper insights into historical periods in which climactic changes, and their associated environmental responses, have had an outsized impact on human history. This has clear implications for our present and future. As climate change accelerates, extreme events, such as floods, drought, storms and wildfires, will become more frequent.

    “Humans have no effect on whether or not a volcano erupts, but the warming trend we are seeing right now is certainly related to human activity,” said Büntgen. “While nothing about the future is certain, we would do well to learn how climate change has affected human civilisation in the past.”

    See the full article here .

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    U Cambridge Campus

    The University of Cambridge (abbreviated as Cantab in post-nominal letters) is a collegiate public research university in Cambridge, England. Founded in 1209, Cambridge is the second-oldest university in the English-speaking world and the world’s fourth-oldest surviving university. It grew out of an association of scholars who left the University of Oxford after a dispute with townsfolk. The two ancient universities share many common features and are often jointly referred to as “Oxbridge”.

    Cambridge is formed from a variety of institutions which include 31 constituent colleges and over 100 academic departments organised into six schools. The university occupies buildings throughout the town, many of which are of historical importance. The colleges are self-governing institutions founded as integral parts of the university. In the year ended 31 July 2014, the university had a total income of £1.51 billion, of which £371 million was from research grants and contracts. The central university and colleges have a combined endowment of around £4.9 billion, the largest of any university outside the United States. Cambridge is a member of many associations and forms part of the “golden triangle” of leading English universities and Cambridge University Health Partners, an academic health science centre. The university is closely linked with the development of the high-tech business cluster known as “Silicon Fen”.

     
  • richardmitnick 10:12 am on September 28, 2020 Permalink | Reply
    Tags: "MAXI J1348−630 is a black hole X-ray binary observations suggest", , , , , , phys.org   

    From phys.org: “MAXI J1348−630 is a black hole X-ray binary, observations suggest” 


    From phys.org

    September 28, 2020
    Tomasz Nowakowski

    1
    Upper panel: Light curves of MAXI J1348−630 in the NICER 0.5–12 keV (filled circles) and MAXI 2–20 keV (black open circles) energy bands. Lower panel: Evolution of the NICER hardness (6–12 keV/2–3.5 keV) and MAXI hardness (4–10 keV/2–4 keV) during the outburst. Credit: Zhang et al., 2020.

    Using the Neutron Star Interior Composition Explorer (NICER), an international team of astronomers has investigated a recently discovered X-ray transient designated MAXI J1348−630. Results of the new observations suggest that the source is a black hole X-ray binary.

    NASA NICER on the ISS.


    NASA/NICER on the ISS.

    The study is detailed in a paper published September 16 in MNRAS.

    X-ray binaries (XRBs) consist of a normal star or a white dwarf transferring mass onto a compact neutron star or a black hole. Many black hole XRBs show transient events that are characterized by outbursts in the X-ray band.

    During these outbursts, astronomers observe mainly the hard and soft spectral states. In the hard state, the spectrum is dominated by a power law-shaped continuum, while in the soft state, the spectrum is dominated by a disc-blackbody emission. However, some black hole XRBs also exhibit an intermediate state in which the hard power-law continuum and a disc thermal emission component make approximately the same contribution to the total spectrum.

    MAXI J1348−630 is an X-ray transient discovered on January 26, 2019 with the Gas Slit Camera (GSC) of the Monitor of All-sky X-ray Image (MAXI) aboard the International Space Station (ISS). Follow-up observations of this source suggest that it is a black hole candidate in a binary system.

    Recently, a group of astronomers led by Liang Zhang of the University of Southampton, U.K., has published a new study supporting the black hole scenario. The research is based on the results from NICER monitoring of MAXI J1348−630 between January 26 and October 8, 2019.

    “We studied the outburst evolution and timing properties of the recently discovered X-ray transient MAXI J1348−630 as observed with NICER. We produced the fundamental diagrams commonly used to trace the spectral evolution, and power density spectra to study the fast X-ray variability,” the researchers explained.

    In general, the researchers found that the spectral evolution of MAXI J1348−630 during its main outburst is similar to what was previously reported for other black hole transients. The source went from the hard state, through the hard-intermediate state and soft-intermediate state, into the soft state in the outburst rise. Afterward, it went back to the hard state in the outburst decay. They noted that the transition from hard to soft state was very fast.

    Furthermore, they detected two re-flares of MAXI J1348−630. These occurred at the end of the main outburst and had peak fluxes one and two orders of magnitude fainter than the main bursting event, respectively. The results show that the source remained in the hard state during the re-flares, never making a transition to the soft state. The astronomers noted that such behavior resembles the so-called “failed outbursts”—those generally less luminous at their peak, not showing any evidence of state transitions, and which are observed in many black hole transients.

    The study also found quasi-periodic oscillations (QPOs) in MAXI J1348−630. They detected different types of low-frequency QPOs at different phases of the main outburst.

    According to the authors of the paper, all the results from NICER monitoring strongly support the hypothesis that MAXI J1348−630 contains a black hole.

    See the full article here .

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    About Science X in 100 words
    Science X™ is a leading web-based science, research and technology news service which covers a full range of topics. These include physics, earth science, medicine, nanotechnology, electronics, space, biology, chemistry, computer sciences, engineering, mathematics and other sciences and technologies. Launched in 2004 (Physorg.com), Science X’s readership has grown steadily to include 5 million scientists, researchers, and engineers every month. Science X publishes approximately 200 quality articles every day, offering some of the most comprehensive coverage of sci-tech developments world-wide. Science X community members enjoy access to many personalized features such as social networking, a personal home page set-up, article comments and ranking, the ability to save favorite articles, a daily newsletter, and other options.
    Mission 12 reasons for reading daily news on Science X Organization Key editors and writersinclude 1.75 million scientists, researchers, and engineers every month. Phys.org publishes approximately 100 quality articles every day, offering some of the most comprehensive coverage of sci-tech developments world-wide. Quancast 2009 includes Phys.org in its list of the Global Top 2,000 Websites. Phys.org community members enjoy access to many personalized features such as social networking, a personal home page set-up, RSS/XML feeds, article comments and ranking, the ability to save favorite articles, a daily newsletter, and other options.

     
  • richardmitnick 7:59 pm on September 25, 2020 Permalink | Reply
    Tags: "Researchers work to create a roadmap on quantum materials", "The 2020 Quantum Materials Roadmap", Catalan Institute for Nanoscience and Nanotechnology ES, Cold Atom Physics, , phys.org,   

    From Catalan Institute for Nanoscience and Nanotechnology ES via phys.org: “Researchers work to create a roadmap on quantum materials” 

    From From Catalan Institute for Nanoscience and Nanotechnology ES

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    phys.org

    1
    Typical skyrmion spin textures where the spin texture is indicated by the arrows. Credit: ICN2.

    The term ‘quantum materials’ was introduced to highlight the exotic properties of unconventional superconductors, heavy-fermion systems (materials with unusual electronic and magnetic properties) and multifunctional oxides. More recently, the definition has broadened to cover all the materials that allow scientists and engineers to explore emergent quantum phenomena and their potential applications.

    This broadening of the concept puts together diverse fields of science and engineering, from condensed-matter and cold-atom physics to materials science and quantum computing. Prof. Feliciano Giustino (The University of Texas at Austin) and ICREA Prof. Stephan Roche (Catalan Institute of Nanoscience and Nanotechnology) proposed themselves to capture a snapshot of the latest developments in this vast and fast-moving research area. With this aim, “The 2020 Quantum Materials Roadmap” review has been published in Journal of Physics: Materials.

    Twenty-nine international leading experts (six of them from BIST centers: Stephan Roche, Adriana I. Figueroa, Regina Galceran, Sergio O. Valenzuela and Marius V. Costache from ICN2, and Pol Forn-Díaz from IFAE) have participated in this roadmap sharing their vision and expertise in different areas: complex oxides, quantum spin-liquids, cuprate superconductors, topological insulators, superconductor and semiconductor qubits, 2-D hyperbolic materials, spin torque materials and magnetic skyrmions are just some of the fancy named objects under study by the experts, which shows to what extent the term quantum materials has indeed broadened. The roadmap also includes work on machine learning, a tool that is becoming increasingly important to catalog, search and design new quantum materials.

    Understanding well all these materials is not only of fundamental interest, but it might also lead to some technological advances, such as the very expected quantum computers, even in a more robust version (the so-called non-abelian topological quantum computers).

    The authors expect that, by offering a big picture of the emerging horizons in quantum materials research and by pointing out the directions where further work and analysis is needed, this roadmap will foster new researches and interdisciplinary collaborations to address these and other as yet unexplored issues.

    See the full article here.

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  • richardmitnick 4:22 pm on September 23, 2020 Permalink | Reply
    Tags: "Study investigates the nature of X-ray binary IGR J18214-1318", , , , , phys.org   

    From phys.org: “Study investigates the nature of X-ray binary IGR J18214-1318” 


    From phys.org

    September 22, 2020
    Tomasz Nowakowski

    1
    Swift’s XRT and BAT broadband spectrum of IGR J18214-1318. Top panel: data and best-fit model tbabs*pcfabs*(nthComp). Bottom panel: residuals in units of standard deviations. Credit: Cusumano et al., 2020.

    Using various space observatories, Italian astronomers have investigated an X-ray binary source known as IGR J18214-1318. Results of the study, detailed in a paper published by MNRAS provide important information about the properties of this system, shedding more light into its nature.

    X-ray binaries consist of a normal star or a white dwarf transferring mass onto a compact neutron star or a black hole. Based on the mass of the companion star, astronomers divide them into low-mass X-ray binaries (LMXBs) and high-mass X-ray binaries (HMXBs).

    IGR J18214-1318 is an HMXB detected with the INTErnational Gamma-Ray Astrophysics Laboratory (INTEGRAL) satellite in 2006.

    ESA/Integral.

    The object is associated to USNO-B1.0 0766-0475700—most likely a star of spectral type O9I.

    In order to get more insights into the nature of IGR J18214-1318, a team of astronomers led by Giancarlo Cusumano of the Institute of Space Astrophysics and Cosmic Physics in Palermo, Italy, has analyzed a dataset covering 13 years of observations of this source with NASA’s Swift spacecraft.

    NASA Neil Gehrels Swift Observatory.

    The study was complemented by data from ESA’s XMM-Newton and NASA’s Nuclear Spectroscopic Telescope Array (NuSTAR) spacecraft.

    ESA/XMM Newton X-ray telescope.

    NASA/DTU/ASI NuSTAR X-ray telescope.

    “In this work we present a temporal and spectral analysis of IGR J18214-1318, a source discovered by INTEGRAL on the galactic plane. (…) We exploited archival data based on Swift, XMM-Newton, and NuSTAR data available on IGR J18214-1318 for an updated study of the spectral and timing properties of this source,” the astronomers wrote in the paper.

    The results indicate that IGR J18214-1318 has an orbital period of approximately 5.42 days. It was calculated that the mass of the system’s neutron star is around 1.4 solar masses, while the companion star, with a radius of about 22 solar radii, turned out to be some 30 times more massive than our sun.

    Based on the results, the researchers estimated that the two components of IGR J18214-1318 are separated by about 41 solar radii, which is a relatively close distance, taking into account the size of the companion star. The astronomers concluded that such tight orbital separation and spectral type of the companion (O9) suggest that IGR J18214-1318 is a wind-accreting source with eccentricity lower than 0.17.

    “Such a tight orbital separation is common among wind-fed neutron stars accreting from an O type companion star,” the authors of the paper noted.

    Furthermore, results from Swift show that the 1–10 keV X-ray spectrum of IGR J18214-1318 is variable. This is because of the changing of local conditions on the neutral absorption and of the accretion rate. When it comes to the hard X-ray spectrum (above 15 keV), it appears to be generally dominated by the exponential tail of the Comptonized component, and depends only on the electrons temperature and the instantaneous mass accretion rate.

    See the full article here .

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    Science X™ is a leading web-based science, research and technology news service which covers a full range of topics. These include physics, earth science, medicine, nanotechnology, electronics, space, biology, chemistry, computer sciences, engineering, mathematics and other sciences and technologies. Launched in 2004 (Physorg.com), Science X’s readership has grown steadily to include 5 million scientists, researchers, and engineers every month. Science X publishes approximately 200 quality articles every day, offering some of the most comprehensive coverage of sci-tech developments world-wide. Science X community members enjoy access to many personalized features such as social networking, a personal home page set-up, article comments and ranking, the ability to save favorite articles, a daily newsletter, and other options.
    Mission 12 reasons for reading daily news on Science X Organization Key editors and writersinclude 1.75 million scientists, researchers, and engineers every month. Phys.org publishes approximately 100 quality articles every day, offering some of the most comprehensive coverage of sci-tech developments world-wide. Quancast 2009 includes Phys.org in its list of the Global Top 2,000 Websites. Phys.org community members enjoy access to many personalized features such as social networking, a personal home page set-up, RSS/XML feeds, article comments and ranking, the ability to save favorite articles, a daily newsletter, and other options.

     
  • richardmitnick 9:08 am on September 22, 2020 Permalink | Reply
    Tags: "New technology is a 'science multiplier' for astronomy", , , , , Federal funding of new technology is crucial for astronomy according to results of a study released Sept. 21 in the Journal of Astronomical Telescopes Instruments and Systems., , Many of the key advances in astronomy over the past three decades benefited directly or indirectly from this early seed funding., , phys.org   

    From Indiana University via phys.org: “New technology is a ‘science multiplier’ for astronomy” 

    Indiana U bloc

    From Indiana University

    via


    phys.org

    September 21, 2020

    1
    The first image of a black hole by the the Event Horizon Telescope in 2019 was enabled in part b support for the NSF’s Advanced Technologies and Instrumentation program. Credit: NASA.

    Federal funding of new technology is crucial for astronomy, according to results of a study released Sept. 21 in the Journal of Astronomical Telescopes, Instruments and Systems.

    The study tracked the long-term impact of early seed funding obtained from the National Science Foundation.

    Many of the key advances in astronomy over the past three decades benefited directly or indirectly from this early seed funding.

    Over the past 30 years, the NSF Advanced Technologies and Instrumentation program has supported astronomers to develop new ways to study the universe. Such devices may include cameras or other instruments as well as innovations in telescope design. The study traced the origins of some workhorse technologies in use today back to their humble origins years or even decades ago in early grants from NSF. The study also explored the impact of technologies that are just now advancing the state-of-the-art.

    The impact of technology and instrumentation research unfolds over the long term. “New technology is a science multiplier” said study author Peter Kurczynski, who served as a Program Director at the National Science Foundation and is now the Chief Scientist of Cosmic Origins at NASA Goddard Space Flight Center. “It enables new ways of observing the universe that were never before possible.” As a result, astronomers are able to make better observations, and gain deeper insights, into the mysteries of the cosmos.

    The study also looked at the impact of grant supported research in the peer-reviewed literature. Papers resulting from technology and instrumentation grants are cited with the same frequency as those resulting from pure science grants, according to the study. Instrumentation scientists “write papers to the same degree, and with the same impact as their peers who do not build instruments,” said Staša Milojevi, associate professor of informatics and the director of the Center for Complex Network and Systems Research in the Luddy School of Informatics, Computing and Engineering at Indiana University, who is a coauthor of the study.

    Also noteworthy is that NSF grant supported research was cited more frequently overall than the general astronomy literature. NSF is considered to have set the gold standard in merit review process for selecting promising research for funding.

    An anonymous reviewer described the article as a “go-to record for anyone needing to know the basic history of many breakthroughs in astronomical technology.” Better observations have always improved our understanding of the universe. From the birth of modern astronomy in the middle ages to the present day, astronomers have relied upon new technologies to reveal the subtle details of the night sky with increasing sophistication.

    This study comes at a critical time of reflection on the nation’s commitment to Science, Technology, Engineering and Math. U.S. preeminence in STEM is increasingly challenged by China and Europe. This study reveals that investments in technology have a tremendous impact for science. Astronomers today are still reaping the benefits of research that was begun decades ago. The future of astronomy depends upon technologies being developed today.

    See the full article here .

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    Indiana U Campus

    Indiana University students get it all—the storybook experience of what college should be like, and the endless opportunities that come with it. Top-ranked academics. Awe-inspiring faculty. Dynamic campus life. International culture. Phenomenal music and arts events. The excitement of IU Hoosier sports. And a jaw-droppingly beautiful campus.

     
  • richardmitnick 12:41 pm on September 21, 2020 Permalink | Reply
    Tags: "Why there is no speed limit in the superfluid universe", Exotic particles stick to all surfaces in superfluids., Lancaster University UK, phys.org, The discovery may guide applications in quantum technology even quantum computing where multiple research groups already aim to make use of these unusual particles.   

    From Lancaster University UK via phys.org: “Why there is no speed limit in the superfluid universe” 

    From Lancaster University UK

    via


    phys.org

    September 21, 2020

    1
    Researchers found the reason for the absence of the speed limit: exotic particles that stick to all surfaces in the superfluid. Credit: Lancaster University UK.

    Physicists from Lancaster University have established why objects moving through superfluid helium-3 lack a speed limit in a continuation of earlier Lancaster research.

    Helium-3 is a rare isotope of helium, in which one neutron is missing. It becomes superfluid at extremely low temperatures, enabling unusual properties such as a lack of friction for moving objects.

    It was thought that the speed of objects moving through superfluid helium-3 was fundamentally limited to the critical Landau velocity, and that exceeding this speed limit would destroy the superfluid. Prior experiments in Lancaster have found that it is not a strict rule and objects can move at much greater speeds without destroying the fragile superfluid state.

    Now scientists from Lancaster University have found the reason for the absence of the speed limit: exotic particles that stick to all surfaces in the superfluid.

    The discovery may guide applications in quantum technology, even quantum computing, where multiple research groups already aim to make use of these unusual particles.

    To shake the bound particles into sight, the researchers cooled superfluid helium-3 to within one ten thousandth of a degree from absolute zero (0.0001K or -273.15°C). They then moved a wire through the superfluid at a high speed, and measured how much force was needed to move the wire. Apart from an extremely small force related to moving the bound particles around when the wire starts to move, the measured force was zero.

    Lead author Dr. Samuli Autti said: “Superfluid helium-3 feels like vacuum to a rod moving through it, although it is a relatively dense liquid. There is no resistance, none at all. I find this very intriguing.”

    Ph.D. student Ash Jennings added: “By making the rod change its direction of motion we were able to conclude that the rod will be hidden from the superfluid by the bound particles covering it, even when its speed is very high.””The bound particles initially need to move around to achieve this, and that exerts a tiny force on the rod, but once this is done, the force just completely disappears”, said Dr. Dmitry Zmeev, who supervised the project.

    The Lancaster researchers included Samuli Autti, Sean Ahlstrom, Richard Haley, Ash Jennings, George Pickett, Malcolm Poole, Roch Schanen, Viktor Tsepelin, Jakub Vonka, Tom Wilcox, Andrew Woods and Dmitry Zmeev. The results are published in Nature Communications.

    See the full article here.

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  • richardmitnick 11:18 am on September 21, 2020 Permalink | Reply
    Tags: "Almost a dozen new variable stars detected in the open cluster NGC 1912 and its surroundings", , , , , , phys.org   

    From Chinese Academy of Sciences via phys.org: “Almost a dozen new variable stars detected in the open cluster NGC 1912 and its surroundings” 

    From Chinese Academy of Sciences

    via


    phys.org

    September 21, 2020
    Tomasz Nowakowski

    1
    Light curves of the newly detected variable star, designated V23, in R, V and B bands. Credit: Li et al., 2020.

    Chinese astronomers have conducted a study of variable stars in the galactic open cluster NGC 1912 and its surrounding field, detecting 11 new variables in this cluster, including binary systems. The study was detailed in a research paper published September 11 on the arXiv pre-print repository, Investigating Variable Stars in the Open Cluster NGC 1912 and Its Surrounding Field.

    Star clusters offer excellent opportunities to study stellar evolution, as they are collections of stars with similar properties, for instance age, distance and initial composition. In particular, astronomers often search for variable stars in young clusters, which could be crucial in advancing the understanding of pre-main-sequence (PMS) stars, and therefore the initial phases of stellar evolution.

    Estimated to be about 300 million years old, NGC 1912 (also known as Messier 38) is an open cluster located some 3,200 light years away, in the anti-center direction of our Milky Way galaxy. So far, over 800 member stars of this cluster have been identified, which includes at least 20 variables of different types such as Delta Scuti, Gamma Doradus, and also eclipsing binaries (EBs).

    Now, a team of astronomers led by Chunyan Li of the Chinese Academy of Sciences (CAS) reports the discovery of 11 new variable stars in NGC 1912 based on observations performed with the Nanshan 1-m telescope (NOWT) of the Xinjiang Astronomical Observatory.

    2
    Nanshan 1-m telescope (NOWT). Xinjiang Astronomical Observatory

    To confirm the membership of the newly found objects, they used the Unsupervised Photometric Membership Assignment in Stellar Clusters (UPMASK) method and data from ESA’s Gaia satellite.

    “We investigated and characterized the variable stars in the open cluster NGC 1912 and its surrounding field by photometric observations,” the astronomers wrote in the paper.

    Out of the 11 newly detected variables, six are Gamma Doradus stars, one is a Delta Scuti star, three are detached binaries and one was classified as a contact binary. Additionally, the study also detected 13 previously known variable stars in NGC 1912.

    The newfound variables have mean instrumental magnitudes in the V band ranging from 15.0 to 18.62 mag, and amplitudes of folded light curves in V band between 0.01 and 1.5. The periods of these stars were measured to be within the range of 0.11 to 2.56 days.

    One of the newfound variables, a Gamma Doradus star designated V4, was confirmed to be the member of NGC 1912. The cluster membership probability of two other Gamma Doradus stars, V3 and V5, was estimated to be 50 and 80 percent. The membership of the remaining eight variables is still highly uncertain.

    The astronomers added that further studies are needed to uncover more insights into the properties of the newly detected variables and to finally confirm their cluster membership. In particular, more data from NASA’s Transiting Exoplanet Survey Satellite (TESS) could help us better understand the nature of variable stars in NGC 1912.

    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 Chinese Academy of Sciences is the linchpin of China’s drive to explore and harness high technology and the natural sciences for the benefit of China and the world. Comprising a comprehensive research and development network, a merit-based learned society and a system of higher education, CAS brings together scientists and engineers from China and around the world to address both theoretical and applied problems using world-class scientific and management approaches.

    Since its founding, CAS has fulfilled multiple roles — as a national team and a locomotive driving national technological innovation, a pioneer in supporting nationwide S&T development, a think tank delivering S&T advice and a community for training young S&T talent.

    Now, as it responds to a nationwide call to put innovation at the heart of China’s development, CAS has further defined its development strategy by emphasizing greater reliance on democratic management, openness and talent in the promotion of innovative research. With the adoption of its Innovation 2020 programme in 2011, the academy has committed to delivering breakthrough science and technology, higher caliber talent and superior scientific advice. As part of the programme, CAS has also requested that each of its institutes define its “strategic niche” — based on an overall analysis of the scientific progress and trends in their own fields both in China and abroad — in order to deploy resources more efficiently and innovate more collectively.

    As it builds on its proud record, CAS aims for a bright future as one of the world’s top S&T research and development organizations.

     
  • richardmitnick 10:18 am on September 21, 2020 Permalink | Reply
    Tags: "High-sensitivity nanoscale chemical imaging with hard x-ray nano-XANES", , EELS-Electron energy-loss spectroscopy, , phys.org, TEM-Transmission electron microscopy, , XAS-X-ray absorption spectrometry   

    From phys.org and Brookhaven National Laboratory: “High-sensitivity nanoscale chemical imaging with hard x-ray nano-XANES” 


    From phys.org

    and

    Brookhaven National Laboratory

    September 21, 2020
    Thamarasee Jeewandara

    1
    Acquisition of nano-XANES. (A) Schematic of the hard x-ray nanoprobe beamline of NSLS-II [below]. As the sample is raster-scanned by a nanobeam produced from a Fresnel zone plate (FZP), diffraction (not used for samples studied in this work), fluorescence, and transmitted signals can all be collected simultaneously. At energy points along the absorption edge, a series of x-ray fluorescence [nano–x-ray fluorescence (XRF)] maps (B) and phase images from ptychography reconstruction (C) are obtained. (D) Representative fluorescence-yield single-pixel XANES fitted with reference standards. Credit: Science Advances, doi: 10.1126/sciadv.abb3615.

    X-rays with excellent penetration power and high chemical sensitivity are suited to understand heterogeneous materials. In a new report on Science Advances, A. Pattammattel, and a team of scientists at the BNL NSLS-II in New York, U.S., described nanoscale chemical speciation by combining scanning nanoprobe and fluorescence-yield X-ray absorption near-edge structure—known as nano-XANES. The team showed the resolving power of nano-XANES by mapping states of iron of a reference sample composed of stainless steel and hematite nanoparticles using 50-nanometer scanning steps. Using nano-XANES, the team also studied the trace secondary phases of lithium iron phosphate (LFP) particles and noted the individual iron(Fe)-phosphide nanoparticles within the pristine lithium iron phosphate, while partially delithiated particles showed Fe-phosphide nanonetworks. This work on nano-XANES highlight the contradictory reports on iron-phosphide morphology within the existing literature and will bridge the capability gap of spectromicroscopy methods to provide exciting research opportunities.

    Multidisciplinarity of nanotechnology

    Nanotechnology is a rapidly growing field and has expanded to multidisciplinary research fields in the past two decades. The field has also unveiled microscopic characterization tools to understand the chemical and physical properties of materials with a significant role in materials science. Researchers have developed a myriad of techniques to study the spectrum of nanomaterials including transmission electron microscopy (TEM) for imaging at atomic resolution and electron energy-loss spectroscopy (EELS) to detect element-specific chemical states and data. However, EELS is limited by poor penetration depth and plural scattering, while in contrast, X-rays have a wide energy range alongside excellent penetration power and high chemical sensitivity. For example, X-ray absorption spectrometry (XAS) is widely used to investigate the chemical state of the absorbing atom. The quantitative chemical imaging achieved with a hard X-ray nanoprobe and single pixel XANES (X-ray absorption near-edge structure) at the nanoscale is still an unchartered territory. In this work, Pattammattel et al. therefore detailed the fluorescence-yield hard X-ray XANES at the nanoscale, hitherto referred to as nano-XANES.

    2
    Quality of nano-XANES and comparison with micro-XANES. A) Fe K-edge nanoXANES spectra of hematite [Fe(III)] and stainless steel [Fe(0)] particles with different integration areas. B) A comparison of nano-XANES Fe(III) and Fe(0) spectra with micro-XANES and the hematite and stainless steel reference standards (collected at the microprobe beamline) showing identical features. Credit: Science Advances, doi: 10.1126/sciadv.abb3615.

    Nano-XANES acquisition

    The scientists demonstrated the technique by performing a benchmark experiment using a reference sample containing mixed stainless steel and hematite nanoparticles. They then applied the technique to characterize the chemical species (i.e. speciation) of lithium battery particles (containing LixFePO4, abbreviated LFP), with a trace secondary Fe-phosphide/Fe-phosphocarbide phase. The high spatial resolution and detection sensitivity of nano-XANES provided unique insight into materials properties under complex environments. The team conducted the nano-XANES experiment at the Hard X-ray Nanoprobe Beamline at the NSLS-II, at the Brookhaven National Laboratory. Using the simultaneously acquired far-field diffraction patterns, Pattammattel et al. generated phase images with a higher spatial resolution through ptychography reconstruction. They then aligned the elemental maps by using an imaging software and created a three-dimensional (3-D) image stack to produce spatially resolved chemical state information. The reference sample used in the work contained stainless steel nanoparticles, hematite nanoparticles and a mixture of the two with a varying thickness from tens to a few hundred nanometers. The team chose the Fe(0)/Fe(III) reference system due to two reasons, which included the distinguishable spectral features and the accuracy of the fitting method.

    3
    Chemical imaging with nano-XANES. (A) Comparison of summed Fe K-edge nano-XANES spectra of Fe(III) and Fe(0) nanoparticles with the bulk ones. (B) and (C) are Fe-Kα XRF and ptychography phase images of hematite [Fe(III)] and stainless steel [Fe(0)] nanoparticle aggregate. (D) Representative single-pixel spectra and their fittings at different locations of the particle are marked in (E), which shows the chemical state map of Fe. (F) XRF map of chromium (alloyed with Fe), overlaid with Fe(0). It confirms the fidelity of the fitting. Scale bars, 800 nm. Data collection details: 120 × 80 points, 50-nm steps, 40-ms dwell time, 77 energy points, and ~8.2 hours total acquisition time. Credit: Science Advances, doi: 10.1126/sciadv.abb3615.

    Troubleshooting nano-XANES acquisition

    The biggest challenge of the technique was maintaining beam stability as the energy varied so that the size and position of the nanobeam did not change, while the illumination of the lens remained constant. The scientists overcame the challenges by aligning the system to predefined energy points, and by creating a look-up table to correct motor positions. The stability of the associated microscope was also critical in the long-term since many acquisitions took up to 10 hours. The team assessed the quality of nano-XANES by comparing the spectrum of each species with a bulk measurement conducted at the X-ray fluorescence microprobe beamline. Pattammattel et al. compared the results with additional techniques for spectromicroscopic imaging to conclude that the fluorescence-yield nano-XANES provided the highest sensitivity.

    Detecting trace secondary phases in lithium iron phosphate particles

    The scientists then used nano-XANES to follow single-particle phase transformations in lithium-ion battery materials. They identified olivine-structured lithium iron phosphate (LiFePO4, LFP) with high chemical contrast and spatial resolution to image chemical changes during battery performance. The LFP is a cathode material commercially used in Li-ion batteries due to its long lifecycle, cost-effectiveness, and low-environmental toxicity. Carbon-coated LFP particles can enhance electronic conductivity but also cause unexpected side reactions including the formation of nanostructured iron-rich compounds (classified in this work as Fe-phosphides).

    4
    Chemical imaging to identify Fe-rich phases in pristine (top) and partially lithiated LFP (bottom). (A and B) XRF map of Fe and P of pristine LFP particle. (C) Chemical state map produced by fitting with Fe(II) and Fe3P reference standards. (D) Phase image from ptychography reconstruction. (E) XANES spectra from selected regions displaying the spectral changes. Scale bars, 1 μm. Data collection details: 100 × 100 points, 60-nm steps, 30-ms dwell time, 53 energy points, and ~5 hours total acquisition time. (F and G) XRF map of Fe and P of the partially lithiated LFP particle. (H) Chemical state map produced by fitting with Fe(II), Fe(III), and Fe3P reference standards. (I) Phase image from ptychography reconstruction. (J to L) Deconvoluted distribution of Fe(II), Fe3P, and Fe(III). (M) XANES spectra from selected regions displaying the spectral changes with deconvoluted phases. Conductive carbon and polymer binder in the electrode are responsible for the background features seen in the phase images. Scale bars, 1.4 μm. Data collection details: 100 × 100 points, 70-nm steps, 30-ms dwell time, 65 energy points, and ~6 hours total acquisition time. Credit: Science Advances, doi: 10.1126/sciadv.abb3615.

    Nano-XANES with high spatial resolution provided a unique X-ray technique to detect chemical species of heterogenous matrices such as carbon-coated LFP (lithium iron phosphate). While spectroscopic differentiation was not possible between Fe-phosphides and carbides due to their similarity in local bonding, the team achieved chemical mapping along with Fe (II) and Fe (III) references. The pristine samples exhibited several 100 to 1000 nm particles of Fe-phosphides surrounding the LFP particle with clear grain boundaries and high resolution in agreement with electron microscopy studies. Since X-rays did not penetrate through the entire thickness of the sample, Pattammattel et al. could not determine if the Fe-phosphide network formed on the surface or inside the particle during this study. The nano-XANES technology provided a unique characterization tool with high penetration depth and detection sensitivity for future investigations.

    Applications of nano-XANES

    The hard X-ray nano-XANES technique can fluorescently bridge the capability gap of existing spectromicroscopy techniques. The team foresee broad applications of the method for nano-speciation of catalytic systems, electrode materials, environmental pollutants and bio-nanosystems. However, they must first overcome a few challenges of the method including self-absorption problems with thick and dense samples, radiation damage by the nanobeam and slow imaging speed. In this way, A. Pattammattel and colleagues expect an optimized tomographic nano-XANES technique to have broad impact on multidisciplinary nanotechnology research and the discovery of unexpected or hidden phases of materials in the future. The improved techniques will greatly enhance the detection capability of nano-XANES to identify trace chemical phases and realize higher chemical specificity as well as detect local bonding structures.

    Previous science paper:
    Nanoscale X-ray imaging
    Nature Photonics

    See the full article here .

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    Brookhaven Campus.


    BNL Center for Functional Nanomaterials.

    BNL NSLS-II.


    BNL NSLS II.


    BNL RHIC Campus.

    BNL/RHIC Star Detector.

    BNL/RHIC Phenix.

    One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. The Laboratory’s almost 3,000 scientists, engineers, and support staff are joined each year by more than 5,000 visiting researchers from around the world. Brookhaven is operated and managed for DOE’s Office of Science by Brookhaven Science Associates, a limited-liability company founded by Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization.

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    Science X™ is a leading web-based science, research and technology news service which covers a full range of topics. These include physics, earth science, medicine, nanotechnology, electronics, space, biology, chemistry, computer sciences, engineering, mathematics and other sciences and technologies. Launched in 2004 (Physorg.com), Science X’s readership has grown steadily to include 5 million scientists, researchers, and engineers every month. Science X publishes approximately 200 quality articles every day, offering some of the most comprehensive coverage of sci-tech developments world-wide. Science X community members enjoy access to many personalized features such as social networking, a personal home page set-up, article comments and ranking, the ability to save favorite articles, a daily newsletter, and other options.
    Mission 12 reasons for reading daily news on Science X Organization Key editors and writersinclude 1.75 million scientists, researchers, and engineers every month. Phys.org publishes approximately 100 quality articles every day, offering some of the most comprehensive coverage of sci-tech developments world-wide. Quancast 2009 includes Phys.org in its list of the Global Top 2,000 Websites. Phys.org community members enjoy access to many personalized features such as social networking, a personal home page set-up, RSS/XML feeds, article comments and ranking, the ability to save favorite articles, a daily newsletter, and other options.

     
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