Computing—Assessing veteran suicide risk 

In collaboration with the Department of Veterans Affairs, a team at Oak Ridge National Laboratory has expanded a VA-developed predictive computing model to identify veterans at risk of suicide and sped it up to run 300 times faster, a gain that could profoundly affect the VA’s ability to reach susceptible veterans quickly. The model, called the medication possession ratio algorithm, creates individualized summaries of veterans’ medication patterns. It helps clinicians pinpoint veterans with inconsistent medication usage who may have a higher risk of attempting suicide. With the accelerated model, “we can observe and reach a much larger population that’s potentially at risk—and look at even more risk factors,” ORNL’s Edmon Begoli said. The sped-up version of the model can assess the behavior patterns of nine million veterans in only 15 minutes. “The potential to provide far greater predictive services is there,” he added. [Contact: Rachel Harken, (865) 576-2057; [email protected]


Caption: ORNL’s project for the Department of Veterans Affairs bridges computing prowess and VA health data to speed up suicide risk screenings for United States veterans. Credit: Carlos Jones/Oak Ridge National Laboratory, U.S. Dept. of Energy 

Transportation—Salting the gears 

Researchers at Oak Ridge National Laboratory proved that a certain class of ionic liquids, when mixed with commercially available oils, can make gears run more efficiently with less noise and better durability. ORNL’s team tested three different oil-soluble ionic liquids on steel under various temperatures, loads and speeds. They found that adding a small percentage of a phosphonium-phosphate ionic liquid into a gear oil can effectively reduce friction, wear loss, cracking, surface damage and associated vibration noises. “The current trend in lubrication is chasing better fuel economy by using less viscous lubricants,” ORNL’s Jun Qu said. “This ionic liquid resulted in oils that perform well with less viscosity, generating a thicker, smoother and more uniform film for superior surface protection.” Results were published in ACS Applied Materials & Interfaces. [Contact: Jennifer Burke, (865) 576-3212; [email protected]] 


Caption: ORNL researchers used a low-viscosity base oil mixed with a small amount of phosphonium-phosphate ionic oil to test the lubricant’s performance on steel. They found the ionic oil mix yielded less surface damage compared to lubrication with commercial gear oil. Credit: Jun Qu/Oak Ridge National Laboratory, U.S. Dept. of Energy 

Neutrons—Lighting up liquid crystals 

Researchers used neutron scattering at Oak Ridge National Laboratory’s Spallation Neutron Source to probe the structure of a colorful new material that may pave the way for improved sensors and vivid displays. Most materials, including many biological photonic structures, exhibit structural colors as light moves through long-range periodic arrangements of elements in their microstructure. Yet, this material can produce striking colors using smaller, local arrangements of nanoplates. Thanks to this unique characteristic, researchers used the material to develop fluidic photonic art. “With neutrons, we saw firsthand how these nanoplates interact with light to form such spectacular colors,” said Texas A&M researcher Zhengdong Cheng. “They were the perfect tools for developing an in-depth understanding of this material’s microstructure.” This discovery could be a significant development in the quest for advanced photonic materials. The research was published in Proceedings of the National Academy of Sciences of the United States of America. ––Gage Taylor [Contact: Jeremy Rumsey, (865) 576-2038; [email protected]] 


Caption: An iridescent droplet of the nanoplate-based liquid crystals Zhengdong Cheng explored with his research team at ORNL’s Spallation Neutron Source, a DOE Office of Science User Facility. Credit: Mingfeng Chen/Texas A&M University and Oak Ridge National Laboratory, U.S. Dept. of Energy 

Manufacturing—Layering on the strength 

A team including Oak Ridge National Laboratory and University of Tennessee researchers demonstrated a novel 3D printing approach called Z-pinning that can increase the material’s strength and toughness by more than three and a half times compared to conventional additive manufacturing processes. They demonstrated Z-pinning with polylactic acid, or PLA, and carbon fiber-reinforced PLA in a 3D printer designed for thermoplastic materials. With conventional 3D printing, the layer-by-layer building up of PLA materials can cause weaknesses between layers. Z-pinning allows continuous material to be deposited across multiple layers within the volume of the part. “The conventional layering approach can cause the strength of the material to decrease as much as 75%,” ORNL’s Vlastimil Kunc said. “The PLA sample with Z-pinning demonstrated uniform mechanical properties when measured in any direction. This technique can be used on any existing 3D printer.” The team’s results were published in the journal Additive Manufacturing. [Contact: Jennifer Burke, (865) 576-3212; [email protected]


Caption: The Z-pinning technique is used to insert reinforcing fibers along the Z-direction of continuous fiber-reinforced plastics. ORNL researchers used PLA to print a small wall, demonstrating that Z-pinning produces mechanically uniform properties when measured in any direction. Credit: Tyler Smith/Oak Ridge National Laboratory, U.S. Dept. of Energy  


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ACS Applied Materials & Interfaces, Jul-2019; PNAS, Aug-2019; Additive Manufacturing, Mar-2019