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How a Single Chemical Bond Balances Cells Between Life and Death

With SLAC's X-ray laser and synchrotron, scientists measured exactly how much energy goes into keeping a crucial chemical bond from triggering a cell's death spiral.

New Efficient, Low-Temperature Catalyst for Converting Water and CO to Hydrogen Gas and CO2

Scientists have developed a new low-temperature catalyst for producing high-purity hydrogen gas while simultaneously using up carbon monoxide (CO). The discovery could improve the performance of fuel cells that run on hydrogen fuel but can be poisoned by CO.

Study Sheds Light on How Bacterial Organelles Assemble

Scientists at Berkeley Lab and Michigan State University are providing the clearest view yet of an intact bacterial microcompartment, revealing at atomic-level resolution the structure and assembly of the organelle's protein shell. This work can help provide important information for research in bioenergy, pathogenesis, and biotechnology.

A Single Electron's Tiny Leap Sets Off 'Molecular Sunscreen' Response

In experiments at the Department of Energy's SLAC National Accelerator Laboratory, scientists were able to see the first step of a process that protects a DNA building block called thymine from sun damage: When it's hit with ultraviolet light, a single electron jumps into a slightly higher orbit around the nucleus of a single oxygen atom.

Researchers Find New Mechanism for Genome Regulation

The same mechanisms that separate mixtures of oil and water may also help the organization of an unusual part of our DNA called heterochromatin, according to a new study by Berkeley Lab researchers. They found that liquid-liquid phase separation helps heterochromatin organize large parts of the genome into specific regions of the nucleus. The work addresses a long-standing question about how DNA functions are organized in space and time, including how genes are silenced or expressed.

The Rise of Giant Viruses

Research reveals that giant viruses acquire genes piecemeal from others, with implications for bioenergy production and environmental cleanup.

Grasses: The Secrets Behind Their Success

Researchers find a grass gene affecting how plants manage water and carbon dioxide that could be useful to growing biofuel crops on marginal land.

SLAC Experiment is First to Decipher Atomic Structure of an Intact Virus with an X-ray Laser

An international team of scientists has for the first time used an X-ray free-electron laser to unravel the structure of an intact virus particle on the atomic level. The method dramatically reduces the amount of virus material required, while also allowing the investigations to be carried out several times faster than before. This opens up entirely new research opportunities.

New Perspectives Into Arctic Cloud Phases

Teamwork provides insight into complicated cloud processes that are important to potential environmental changes in the Arctic.

Illuminating a Better Way to Calculate Excitation Energy

In a new study appearing this week in The Journal of Chemical Physics, researchers demonstrate a new method to calculate excitation energies. They used a new approach based on density functional methods, which use an atom-by-atom approach to calculate electronic interactions. By analyzing a benchmark set of small molecules and oligomers, their functional produced more accurate estimates of excitation energy compared to other commonly used density functionals, while requiring less computing power.


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Chicago Quantum Exchange to Create Technologically Transformative Ecosystem

The University of Chicago is collaborating with the U.S. Department of Energy's Argonne National Laboratory and Fermi National Accelerator Laboratory to launch an intellectual hub for advancing academic, industrial and governmental efforts in the science and engineering of quantum information.

Department of Energy Awards Six Research Contracts Totaling $258 Million to Accelerate U.S. Supercomputing Technology

Today U.S. Secretary of Energy Rick Perry announced that six leading U.S. technology companies will receive funding from the Department of Energy's Exascale Computing Project (ECP) as part of its new PathForward program, accelerating the research necessary to deploy the nation's first exascale supercomputers.

Cynthia Jenks Named Director of Argonne's Chemical Sciences and Engineering Division

Argonne has named Cynthia Jenks the next director of the laboratory's Chemical Sciences and Engineering Division. Jenks currently serves as the assistant director for scientific planning and the director of the Chemical and Biological Sciences Division at Ames Laboratory.

Argonne-Developed Technology for Producing Graphene Wins TechConnect National Innovation Award

A method that significantly cuts the time and cost needed to grow graphene has won a 2017 TechConnect National Innovation Award. This is the second year in a row that a team at Argonne's Center for Nanoscale Materials has received this award.

Honeywell UOP and Argonne Seek Research Collaborations in Catalysis Under Technologist in Residence Program

Researchers at Argonne are collaborating with Honeywell UOP scientists to explore innovative energy and chemicals production.

Follow the Fantastic Voyage of the ICARUS Neutrino Detector

The ICARUS neutrino detector, born at Gran Sasso National Lab in Italy and refurbished at CERN, will make its way across the sea to Fermilab this summer. Follow along using an interactive map online.

JSA Awards Graduate Fellowships for Research at Jefferson Lab

Jefferson Sciences Associates announced today the award of eight JSA/Jefferson Lab graduate fellowships. The doctoral students will use the fellowships to support their advanced studies at their universities and conduct research at the Thomas Jefferson National Accelerator Facility (Jefferson Lab) - a U.S. Department of Energy nuclear physics laboratory managed and operated by JSA, a joint venture between SURA and PAE Applied Technologies.

Muon Magnet's Moment Has Arrived

On May 31, the 50-foot-wide superconducting electromagnet at the center of the Muon g-2 experiment saw its first beam of muon particles from Fermilab's accelerators, kicking off a three-year effort to measure just what happens to those particles when placed in a stunningly precise magnetic field. The answer could rewrite scientists' picture of the universe and how it works.

Seven Small Businesses to Collaborate with Argonne to Solve Technical Challenges

Seven small businesses have been selected to collaborate with researchers at Argonne to address technical challenges as part of DOE's Small Business Vouchers Program.

JSA Names Charles Perdrisat and Charles Sinclair as Co-Recipients of its 2017 Outstanding Nuclear Physicist Prize

Jefferson Science Associates, LLC, announced today that Charles Perdrisat and Charles Sinclair are the recipients of the 2017 Outstanding Nuclear Physicist Prize. The 2017 JSA Outstanding Nuclear Physicist Award is jointly awarded to Charles Perdrisat for his pioneering implementation of the polarization transfer technique to determine proton elastic form factors, and to Charles Sinclair for his crucial development of polarized electron beam technology, which made such measurements, and many others, possible.


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Oxygen: The Jekyll and Hyde of Biofuels

Scientists are devising ways to protect plants, biofuels and, ultimately, the atmosphere itself from damage caused by an element that sustains life on earth.

The Rise of Giant Viruses

Research reveals that giant viruses acquire genes piecemeal from others, with implications for bioenergy production and environmental cleanup.

Grasses: The Secrets Behind Their Success

Researchers find a grass gene affecting how plants manage water and carbon dioxide that could be useful to growing biofuel crops on marginal land.

New Perspectives Into Arctic Cloud Phases

Teamwork provides insight into complicated cloud processes that are important to potential environmental changes in the Arctic.

Mountaintop Plants and Soils to Become Out of Sync

Plants and soil microbes may be altered by climate warming at different rates and in different ways, meaning vital nutrient patterns could be misaligned.

If a Tree Falls in the Amazon

For the first time, scientists pinpointed how often storms topple trees, helping to predict how changes in Amazonia affect the world.

Turning Waste into Fuels, Microbial Style

A newly discovered metabolic process linking different bacteria in a community could enhance bioenergy production.

Department of Energy Awards Six Research Contracts Totaling $258 Million to Accelerate U.S. Supercomputing Technology

Today U.S. Secretary of Energy Rick Perry announced that six leading U.S. technology companies will receive funding from the Department of Energy's Exascale Computing Project (ECP) as part of its new PathForward program, accelerating the research necessary to deploy the nation's first exascale supercomputers.

Electrifying Magnetism

Researchers create materials with controllable electrical and magnetic properties, even at room temperature.

One Step Closer to Practical Fast Charging Batteries

Novel electrode materials have designed pathways for electrons and ions during the charge/discharge cycle.


Small Scale, Big Improvements

Article ID: 676308

Released: 2017-06-13 13:05:08

Source Newsroom: University of Delaware

Methods to improve water purification or build better batteries are problems that have challenged scientists for decades. Advances have inched forward, but rising demand moves the finish line further and further away.

At the same time, the chemical reactions that make these improvements possible occur at scales invisible to the naked eye (the atomic scale) where liquids and solid surfaces meet, making the work even more difficult.

Knowing how these chemical interactions occur at the solid-liquid interface is critical in problems of great interest to the Department of Energy (DOE), particularly as it relates to environmental and water quality issues that may be affected by large-scale energy production activities.

Now, a new technique developed by a team including University of Delaware Prof. Neil Sturchio and colleagues at Argonne National Laboratory and the University of Illinois at Chicago has produced real-time observations documenting the chemical reactions that happen between liquids and solids.

The technique provides data that can be used to improve predictions of how nutrients and contaminants will move in natural systems or to gauge the effectiveness of water purification methods where ion exchange is critical to sanitization.

It also may help scientists tease out limiting factors to supercapacitors -- robust energy storage devices that are often used over common batteries to power consumer electronics, hybrid vehicles, even large industrial-scale power.

Energy exchange in chemical reactions

Sturchio, a geochemist, has studied mineral/water interactions for 25 years with funding from DOE. He and his collaborators recently demonstrated a new way of studying the microscopic structure and processes that occur where minerals and water meet, using X-ray beams to trigger the reactions while capturing images of their effects on the mineral surface.

Now using a method called Resonant Anomalous X-Ray Reflectivity (RAXR), the researchers are able to go one step further and distinguish the identity of the element being studied.

"With our previous methods, we could see the atomic-scale electron density profile of the interfacial region -- a nanometer-thick zone including the mineral surface and the adjacent solution -- but couldn't uniquely identify the atomic layers," said Sturchio, professor and chair of the Department of Geological Sciences in UD's College of Earth, Ocean, and Environment.

The technique requires a high-quality crystal so the researchers selected mica, a mineral similar in structure to the abundant clay minerals in soils that produces an atomically flat crystal useful in laboratory investigations of interfacial properties.

The researchers reflected an intense X-ray beam off a mica sample in alternating contact with two different salt solutions containing rubidium and sodium chloride. By changing the angle of the beam, scientists were able to scan the interfacial profile at atomic scale. By changing the energy of the beam at a fixed angle, they could isolate the distribution of rubidium ions in the interfacial region.

"In this case, we can tune in and ask specifically where is the rubidium? How is it attached to the mica crystal and how is it released to the solution?" he said.

According to Sturchio, most chemical reactions in groundwater and in the atmosphere, as well as during industrial processes including water purification and some forms of energy storage, happen at surfaces such as electrodes or particles. As a chemical reaction occurs, ions are kicked off or pulled on and energy is exchanged. Understanding quantitatively how the ions are exchanged at this scale can be used to design chemical processes to improve water purification or understand how contaminants are transported in soil and groundwater.

In this project, the researchers wanted to see what it would take to get the rubidium, an alkali metal, to release from the mica surface once it was attached. They accomplished this by quickly changing the solution flowing over the mica crystal from rubidium chloride to a more concentrated sodium chloride, then timed the reaction to determine how long it took for the rubidium ions to release (desorb) from the mica and for the sodium chloride ions to take their place (adsorb).

Generally, adsorption reactions are thought to occur in milliseconds, but here it took 25 seconds for the rubidium to release from the surface (desorption) and the sodium ions to take its place (adsorption).

The closer the rubidium was to the mineral/water interface, the more fixed its position became (because of electrostatic energy - the kind that makes a balloon stick to a wall after you rub it against a sweater) and the more energy was required to pry it away from the mica. Conversely, the more water molecules between the crystal's surface and the rubidium ion, the more wiggle room the rubidium had in its position and the less energy it took to break away. The experiments helped to quantify the minute amounts of energy transferred during alkali ion exchange at this interface, and the involvement of water molecules in the reaction mechanism.

The reaction was slower than the researchers anticipated, and while further study is required, they agree the results provide evidence for understanding the timeframes necessary for desired reactions to occur.

By contrast, when the solutions were switched back, the rubidium adsorbed onto the mica surface much more rapidly than it desorbed, by shedding its attached water molecules, demonstrating that hydration is important to the reaction.

"To design an industrial process you need to know exactly what's happening at the surface," Sturchio said. "As far as we know, this is the first time anyone has documented such detailed information on how these ion exchange reactions are happening at a mineral surface in contact with water, and in this case, we have good evidence for how long it actually takes."

The study was published Friday, June 9, in the journal Nature Communications. The work, titled "Real-time observations of cation exchange kinetics and dynamics at the muscovite-water interface," was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Chemical Sciences, Geosciences, and Biosciences Division under contracts DE-AC02-06CH11357.

Sang Soo Lee, a clay mineralogist, and Paul Fenter, principal investigator on the project and a physicist and X-ray scattering expert, both with Argonne National Laboratory, designed the study. UD's Sturchio and Kathryn L. Nagy, a geochemist and clay mineral expert at University of Illinois at Chicago, were co-authors on the work.