The composition of occupied and unoccupied electronic states in the vicinity of Fermi energies is vital for all materials and relates to their physical, chemical and mechanical properties. This work demonstrates how the combination of resonant and non-resonant X-ray emission spectroscopies supplemented with theoretical modelling allows for quantitative analysis of electronic states in 5d transition metal and metal-oxide materials. Application of X-rays provides element selectivity that, in combination with the penetrating properties of hard X-rays, allows determination of the composition of electronic states under working conditions, i.e. non-vacuum environment. Tungsten metal and tungsten oxide are evaluated to show the capability to simultaneously assess composition of around-band-gap electronic states as well as the character and magnitude of the crystal field splitting.

Strain tensor measurements are important for understanding elastic and plastic deformation, but full bulk strain tensor measurement techniques are still lacking, in particular for dynamic loading. Here, such a methodology is reported, combining imaging-based strain field mapping and simultaneous X-ray diffraction for four typical loading modes: one-dimensional strain/stress compression/tension. Strain field mapping resolves two in-plane principal strains, and X-ray diffraction analysis yields volumetric strain, and thus the out-of-plane principal strain. This methodology is validated against direct molecular dynamics simulations on nanocrystalline tantalum. This methodology can be implemented with simultaneous X-ray diffraction and digital image correlation in synchrotron radiation or free-electron laser experiments.

The unique diagnostic possibilities of X-ray diffraction, small X-ray scattering and phase-contrast imaging techniques applied with high-intensity coherent X-ray synchrotron and X-ray free-electron laser radiation can only be fully realized if a sufficient dynamic range and/or spatial resolution of the detector is available. In this work, it is demonstrated that the use of lithium fluoride (LiF) as a photoluminescence (PL) imaging detector allows measuring of an X-ray diffraction image with a dynamic range of ∼107 within the sub-micrometre spatial resolution. At the PETRA III facility, the diffraction pattern created behind a circular aperture with a diameter of 5 µm irradiated by a beam with a photon energy of 500 eV was recorded on a LiF crystal. In the diffraction pattern, the accumulated dose was varied from 1.7 × 105 J cm−3 in the central maximum to 2 × 10−2 J cm−3 in the 16th maximum of diffraction fringes. The period of the last fringe was measured with 0.8 µm width. The PL response of the LiF crystal being used as a detector on the irradiation dose of 500 eV photons was evaluated. For the particular model of laser-scanning confocal microscope Carl Zeiss LSM700, used for the readout of the PL signal, the calibration dependencies on the intensity of photopumping (excitation) radiation (λ = 488 nm) and the gain have been obtained.

A gas- and vapour-pressure control system synchronized with the continuous data acquisition of millisecond high-resolution powder diffraction measurements was developed to study structural change processes in gas storage and reaction materials such as metal organic framework compounds, zeolite and layered double hydroxide. The apparatus, which can be set up on beamline BL02B2 at SPring-8, mainly comprises a pressure control system of gases and vapour, a gas cell for a capillary sample, and six one-dimensional solid-state (MYTHEN) detectors. The pressure control system can be remotely controlled via developed software connected to a diffraction measurement system and can be operated in the closed gas and vapour line system. By using the temperature-control system on the sample, high-resolution powder diffraction data can be obtained under gas and vapour pressures ranging from 1 Pa to 130 kPa in temperatures ranging from 30 to 1473 K. This system enables one to perform automatic and high-throughput in situ X-ray powder diffraction experiments even at extremely low pressures. Furthermore, this developed system is useful for studying crystal structures during the adsorption/desorption processes, as acquired by millisecond and continuous powder diffraction measurements. The acquisition of diffraction data can be synchronized with the control of the pressure with a high frame rate of up to 100 Hz. In situ and time-resolved powder diffraction measurements are demonstrated for nanoporous Cu coordination polymer in various gas and vapour atmospheres.

Double-sided Fresnel zone plates are diffractive lenses used for high-resolution hard X-ray microscopy. The double-sided structures have significantly higher aspect ratios compared with single-sided components and hence enable more efficient imaging. The zone plates discussed in this paper are fabricated on each side of a thin support membrane, and the alignment of the zone plates with respect to each other is critical. Here, a simple and reliable way of quantifying misalignments by recording efficiency maps and measuring the absolute diffraction efficiency of the zone plates as a function of tilting angle in two directions is presented. The measurements are performed in a setup based on a tungsten-anode microfocus X-ray tube, providing an X-ray energy of 8.4 keV through differential measurements with a Cu and an Ni filter. This study investigates the sources of the misalignments and concludes that they can be avoided by decreasing the structure heights on both sides of the membrane and by pre-programming size differences between the front- and back-side zone plates.

This article describes a high-efficiency experimental configuration for a self-referenced lattice comparator with a `brush beam' of synchrotron radiation from a bending magnet and two linear position-sensitive photon-counting-type X-ray detectors. The efficiency is more than ten times greater compared with the `pencil-beam' configuration and a pair of zero-dimensional detectors. A solution for correcting the systematic deviation of d-spacing measurements caused by the horizontal non-uniformity of the brush beam is provided. Also, the use of photon-counting-type one-dimensional detectors not only improves the spatial resolution of the measurements remarkably but can also adjust the sample's attitude angles easily.

Errors in the article by Opara, Martiel, Arnold, Braun, Stahlberg, Makita, David & Padeste [J. Appl. Cryst. (2017), 50, 909–918] are corrected.

The residual strain distribution has been measured as a function of depth in both top coat and bond coat in as-received and heat-treated air plasma sprayed thermal barrier coating samples. High-energy synchrotron X-ray beams were used in transmission to produce full Debye–Scherrer rings whose non-circular aspect ratio gave the in-plane and out-of-plane strains far more efficiently than the sin2ψ method. The residual strain in the bond coat is found to be tensile and the strain in the β phase of the as-received sample was measured. The residual strains observed in the top coat were generally compressive (increasing towards the interface), with two kinds of nonlinear trend. These was a `jump' feature near the interface, and in some cases there was another `jump' feature near the surface. It is shown how these trend differences can be correlated to cracks in the coating.

A historical tool for crystallographic analysis is provided by the Hilton net, which can be used for manually surveying the crystal lattice as it is manifested by the Kikuchi bands in a gnomonic projection. For a quantitative analysis using the Hilton net, the projection centre as the relative position of the signal source with respect to the detector plane needs to be known. Interplanar angles are accessible with a precision and accuracy which is estimated to be ≤0.3°. Angles between any directions, e.g. zone axes, are directly readable. Finally, for the rare case of an unknown projection-centre position, its determination is demonstrated by adapting an old approach developed for photogrammetric applications. It requires the indexing of four zone axes [uvw]i in a backscattered Kikuchi diffraction pattern of a known phase collected under comparable geometric conditions.

In order to improve the instrumental accessibility of neutron diffraction techniques, many emerging compact neutron sources and in-house neutron diffractometers are being developed, even though the precision level of neutron diffraction experiments performed on such instruments was thought to be incomparable with that of large-scale neutron facilities. As a challenging project, the RIKEN accelerator-driven compact neutron source (RANS) was employed here to establish the technical environment for texture measurements, and the recalculated pole figures and orientation distribution functions of an interstitial-free steel sheet obtained from RANS were compared with the results from another two neutron diffractometers well established for texture measurement. These quantitative comparisons revealed that the precise neutron diffraction texture measurement at RANS has been realized successfully, and the fine region division of the neutron detector panel is invaluable for improving the stereographic resolution of texture measurements. Moreover, through selectively using the parts of the obtained neutron diffraction patterns that exhibit good statistics, the Rietveld texture analysis improves the reliability of the texture measurement to a certain extent. These technical research results may accelerate the development of other easily accessible techniques for evaluation of engineering materials using compact neutron sources, and also help to improve the data-collection efficiency for various time-resolved scattering experiments at large-scale neutron facilities.

An energy resolution of <10 µeV for the measurement of phonon energy change is achieved with the inelastic neutron spin echo technique on a conventional neutron triple-axis spectrometer.

The sin2ψ and cosα methods are compared via diffracting-grain identification from electron backscatter diffraction maps. Artificial textures created by the X-ray diffraction measurements are plotted and X-ray elastic constants of the diffracting-grain sets are computed.

This paper reports on the two-scale fractal structure of chromatin organization in the nucleus of the HeLa cell.

A new approach to variable-temperature measurements is presented, where the sample temperature changes continuously as a function of position.

Instrumentation for sub-millisecond time-resolved small-angle neutron scattering measurements at NIST is described and applied to the reorientation dynamics of elongated hematite nanoparticles.

The diffraction response of a single crystal to electric field measured by X-ray diffraction by angles close to π. Such schemes allow one to determine with high (~ 10–5–10–6) accuracy the relative changes in the lattice constant.

A new census of tropical sulfur butterflies (Aphrissa statira) migrating across the Panama Canal has revealed the central role that weather plays in determining why populations of these lemon-yellow insects vary from year to year.

The post A dry spring in Panama means more sulfur butterflies, study reveals appeared first on Smithsonian Insider.

For the first time, astronomers have found a supernova explosion with properties similar to a gamma-ray burst, but without seeing any gamma rays from it.

The post Astronomers Find Rare Supernova by New Means appeared first on Smithsonian Insider.

Birds do it. Bees do it. And in a laboratory in northern California, scientists using bumblebees recently figured out the best way to measure it--vertical lift!

The post Laboratory tests reveal precise way to measure vertical lift in bumblebees and other small insects and birds appeared first on Smithsonian Insider.

The crustaceans are much more effective when they fight together than when they fight alone, a process McKeon calls the Multiple Defender Effect. “It is a clear example of synergy, and one that underscores the importance of biodiversity in the ocean.”

The post Preventing home invasions means fighting side-by-side for coral-dwelling crabs and shrimp appeared first on Smithsonian Insider.

Scientists have discovered an incredible story of fungal fidelity among certain species of ants.

The post Fungal fidelity: some ants have been eating the same meal for 5 million years! appeared first on Smithsonian Insider.

Warming temperatures may mean more generations of monarch butterflies in North America during summer months, say scientists who recently finished experiments with monarch caterpillars and […]

The post Warming temperatures may mean more monarch generations in some areas of North America appeared first on Smithsonian Insider.

Now here is something to ruminate on. About 85 percent of the methane produced by a cow comes out of its mouth as burps. The […]

The post Monitoring methane? Now there is a better way to measure appeared first on Smithsonian Insider.

In many ways stars are like living beings. They’re born; they live; they die. And they even have a heartbeat. Using a novel technique, astronomers […]

The post DISCOVERY MEASURES “HEARTBEATS” OF A DISTANT GALAXY’S STARS appeared first on Smithsonian Insider.

Poaching wasn’t the largest conservation concern for Asian elephants, an endangered species, until satellite tracking stunned researchers. Scientists at the Smithsonian Conservation Biology Institute (SCBI) […]

The post Poachers are killing endangered Asian elephants for their skin and meat, not their tusks appeared first on Smithsonian Insider.

Smithsonian scientists have joined NASA and other organizations this summer to do something incredible: launch a spacecraft, the Parker Solar Probe, into space and have […]

The post A solar probe is on its way to touch the sun. The Smithsonian built the tool that will measure the sun without melting appeared first on Smithsonian Insider.

The last time Earth experienced both ice sheets and carbon dioxide levels within the range predicted for this century was a period of major sea […]

The post What the Ancient CO2 Record May Mean for Future Climate Change appeared first on Smithsonian Insider.

What is the average blood pressure of a geriatric sloth bear? Asia Trail keeper Stacey Tabellario is hoping to learn exactly that, as she trains […]

The post Measuring Sloth Bear Blood Pressure appeared first on Smithsonian Insider.

The North Pole isn’t the only place on Earth affected by slight increases in temperature. Until recently, scientific thinking used to posit that tropical forests, […]

The post Rising temperatures mean more blooms for tropical rainforests appeared first on Smithsonian Insider.

Living trees can rot from the inside out, leaving only a hollowed trunk. Wood rot in living trees can cause overestimates of global carbon pools, […]

The post Measuring trees with the speed of sound appeared first on Smithsonian Insider.

While the Federal Motor Carrier Safety Administration’s (FMCSA) Safety Measurement System (SMS) used to identify commercial motor vehicle carriers at high risk for future crashes is conceptually sound, several features of its implementation need improvement, says a new congressionally mandated report from the National Academies of Sciences, Engineering, and Medicine.

The emergence of inexpensive small unmanned aircraft systems (sUASs) that operate without a human pilot, commonly known as drones, has led to adversarial groups threatening deployed U.S. forces, especially infantry units.

The current measles outbreaks in the United States and elsewhere are being fueled by misinformation about the safety of vaccines.

A new report from the National Academies of Sciences, Engineering, and Medicine recommends steps U.S. communities can take to better measure their progress in building resilience to disasters, including measuring resilience around multiple dimensions of a community, and incentivizing the measurement of resilience.

A centralized, consistently reported system of indicators of educational equity is needed to bring attention to disparities in the U.S. education system, says a new report by the National Academies of Sciences, Engineering, and Medicine.

As the coronavirus outbreak has spread throughout the United States, social distancing measures have taken many forms — such as business and school closures, cancelled events, and everyone being urged to keep six feet apart.

When it comes to COVID-19 testing, questions remain about which of the tests available are reliable, how much testing is needed, and how to ensure access to testing. The latest COVID-19 Conversations webinar explored the challenges ahead.

Exide begins to remove lead-polluted soil on Monday morning at a house on the 1200 block of La Puerta Street in Boyle Heights.; Credit: Maya Sugarman/KPCC

All five members of the Los Angeles County Board of Supervisors have signed a letter imploring California Gov. Jerry Brown to intervene in the state’s handling of contamination around the Exide Technologies plant in Vernon.

The letter criticizing the state’s “piecemeal approach to an urgent environmental hazard” comes as workers paid for by Exide are removing lead-contaminated topsoil from two homes near the intersection of Olympic and Indiana avenues in L.A. 

Signed Tuesday, the letter asks for “guaranteed state funding to immediately begin testing” at 37 more homes also sampled, but to less specific degrees, during November 2013. In the words of the board, “further testing and remediation of the other 37 homes has not been confirmed and may not begin until at least October 2014 because Exide has not yet agreed to comply with DTSC directives issued last March.”

The supervisors also say the state has “reneged” on its commitments to test for lead inside the homes as well as outside.

The Department of Toxic Substances Control says that the two homes workers are at this week will be cleaned inside and out — even without indoor testing.  The DTSC’s Rizgar Ghazi said Monday that crews will use HEPA filters, vacuums and shampooing equipment on “basically any flat surface” inside the two residences.

Read the L.A. Board of Supervisors’ letter to Gov. Brown here:

http://www.scribd.com/doc/236655733/LA-County-Supervisors-Letter-to-Gov-Brown-8-12-14

This content is from Southern California Public Radio. View the original story at SCPR.org.

A woman passes a closed Social Security Administration office in Los Angeles in 2013. Some 53,000 of the agency's workers are now working from home.; Credit: Frederic J. Brown/AFP via Getty Images

The coronavirus pandemic has forced many people to work from home, and that includes employees of the federal government. The numbers vary by agency, but at the Social Security Administration, some 53,000 workers are doing so.

Social Security field offices are closed. But the shutdown hasn't stopped the agency from processing claims for new benefits and appeals of benefit denials. And according to statistics that the SSA sent its workers, the agency has been doing so at a faster pace than before.

"Telework is proving a great boon to the service Social Security provides to the American people," says Ralph deJuliis, who works at the SSA's office in Tulsa, Okla. "We are getting the checks to people faster and quicker."

DeJuliis is president of the American Federation of Government Employees Council 220, which represents many Social Security workers. And he says he hopes the SSA will continue allowing employees to work from home.

Telework, he says, is "good for the employees, good for the public. We've got the work done. We kept the public out of harm's way because, let's face it, we deal with mostly people who are old or disabled. They are at the highest risk."

According to deJuliis, the SSA has found that its backlog of pending cases has fallen by 11% since March 23, when the agency instituted wide-scale telework, and that calls from recipients are answered more quickly.

Isabel Sawhill, a senior fellow at the Brookings Institution, says it's not surprising that productivity is up.

"Actually, there are studies that have been done, including studies in government agencies — small-scale studies, to be sure — but they have shown that productivity does rise when people get to work from home," she says.

Jeff Neal, a former head of human resources at the Department of Homeland Security, says it's not surprising that people become more productive when they work from home.

"The really good workers might be sitting there at their home desk, wherever that is," he says. "And they're supposed to stop at 5 o'clock, and they look at their watch or their computer and they realize it's 7 o'clock and they've still been working, because they get into things and they start getting stuff done and they just keep on going."

It's unclear how many federal workers across the government are teleworking. According to the most recent statistics, from two years ago, 42% of the some 2.1 million government employees were eligible to telework, although only about half of those were in fact working from home.

The Trump administration had been hostile to teleworking, Neal says, because in its view it sees it as a benefit to federal workers. But Neal says it's also a benefit to taxpayers.

"If people view it as what it really is, which is something that is in the interest of the federal government to have, then they would continue it because it helps them hire. It helps them retain people," he says. "And most importantly, it helps them remain operational during a national emergency. So it's a very good thing."

And Sawhill at Brookings says she expects teleworking will continue to increase both in government and the private sector after the coronavirus crisis ends.

"This experience has showed us that we can get work done at home and that we can meet people's needs, the public's needs, by doing so," she says. "That doesn't mean there aren't lots of downsides. But overall, I think this is a trend that is going to accelerate sharply as a result of this recent experience."

The federal government has not given any guidance as to when it expects all federal workers to return to their offices.

The SSA issued a statement saying it continues to monitor the COVID-19 situation across the nation, promising that when it does reopen offices, it will provide a safe environment for the people it serves and its employees.

This content is from Southern California Public Radio. View the original story at SCPR.org.

Tesoro says it’s been planning for a strike and will continue operating two of the effected refineries, including one in Carson.; Credit: Getty Images

More than 800 workers walked off the job early Sunday at an oil refinery in Carson because of a labor dispute, joining workers at eight other refineries around the country. 

National strikes have been rare in the refining business. The last one happened in 1980, and it took three months to resolve. If this dispute lasts that long, analysts say gas prices could rise.

“It’s very possible we may have seen the last of two dollar gasoline in the near term,” said Carl Larry director of oil and gas at consulting firm Frost & Sullivan. “Without production from these refineries, we’re going to see tighter supply and higher prices."

Making matters worse, many refineries are switching over to summer blend gas, which is cleaner burning, but also more expensive.

Jim Burkhard, Managing Director at IHS Cambridge Energy Research Associates, cautions that it is too soon to know what the effect of the strike will be, and even though the steelworkers have 64 percent of U.S. oil output in their hands, there’s still a lot of other supply.

 “Remember the oil market overall is very well supplied right now,” said Burkhard. "There's plenty of refining capacity around the world, you would just have some modification of trade flows."

The Carson refinery processes 363,000 barrels per day at peak capacity and employs 1,450 workers. Tesoro Corporation, which operates the plant, says it’s been planning for a strike and will continue operations.

"Tesoro is confident that the Company can continue to safely operate the refineries and meet customer commitments until resolution is reached with the [United Steel Workers]," Tesoro said in a written statement.

The USW represents workers at 65 U.S. refineries. It says the facilities where workers have not walked out will continue operating under a rolling 24-hour contract extension. 

“This work stoppage is about onerous overtime; unsafe staffing levels; dangerous conditions the industry continues to ignore; the daily occurrences of fires, emissions, leaks and explosions that threaten local communities without the industry doing much about it; the industry’s refusal to make opportunities for workers in the trade crafts; the flagrant contracting out that impacts health and safety on the job; and the erosion of our workplace, where qualified and experienced union workers are replaced by contractors when they leave or retire,” USW International Vice President Gary Beevers said in a written statement.

This content is from Southern California Public Radio. View the original story at SCPR.org.

A standardised method to help choose the most cost-effective measures to remediate contaminated sites has been developed by Austrian researchers. The method takes into account a wide range of factors, including the principles of sustainability.

Current knowledge on the availability of mineral resources is explored in a recent study, which focuses on phosphorus as a key example. Static measures of availability, such as the consumption-to-production ratio, are useful as early warning signals, the researchers suggest, but more dynamic indicators that consider technological development and population change are needed to better inform policy.

Assessing the potential of new environmental management tools often brings an ???innovation dilemma???: is it better to stick with what is known to work, or to implement new measures that are potentially more effective, but also more uncertain? Researchers have proposed an approach to deal with these dilemmas, and applied it to the case study of an invasive species programme in the US.

Two tagged Cuvier's beaked whales have shown intense and lasting avoidance behaviours in response to military sonar. In the first study of this kind, the whales showed significant responses to sonar at volumes that are currently assumed in the US to have no effect on behaviour.