Story Tips From the Department of Energy’s Oak Ridge National Laboratory

August 2019

 

To arrange for an interview with a researcher, please contact the Communications staff member identified at the end of each tip. For more information on ORNL and its research and development activities, please refer to one of our media contacts. If you have a general media-related question or comment, you can send it to news@ornl.gov.

 

Computing—“Seeing” in real time

 

Oak Ridge National Laboratory is training next-generation cameras called dynamic vision sensors, or DVS, to interpret live information—a capability that has applications in robotics and could improve autonomous vehicle sensing. Unlike a traditional digital camera that records large amounts of information in frames, a DVS transmits per-pixel changes in light intensity. Individual pixel locations are recorded and time stamped to the microsecond, creating data “events” that are processed by a neuromorphic network—a type of intelligent, energy-efficient computing architecture. “Because the DVS records only changes in what it sees, there is no redundant data,” said ORNL SULI intern Kemal Fidan, who spent his summer learning about dynamic vision sensors under ORNL’s Robert Patton. This capability makes the sensors fast, power efficient and effective in wide ranges of light intensity. Fidan’s project taught a DVS to recognize human gestures such as waving, clapping and two-finger peace signs in real time.Abby Bower [Contact: Sara Shoemaker, (865) 576-9219; shoemakerms@ornl.gov]

 

Video: https://www.youtube.com/watch?v=w9b9dvt-NYs&feature=youtu.be

 

Caption: Dynamic vision sensors at Oak Ridge National Laboratory were trained to detect and recognize 11 different gestures, like waving and clapping, in real time. The resulting image shows movement on the pixel level. Credit: Kemal Fidan/Oak Ridge National Laboratory, U.S. Dept. of Energy

 

Fusion—Tungsten rising

 

Using additive manufacturing, scientists experimenting with tungsten at Oak Ridge National Laboratory hope to unlock new potential of the high-performance heat-transferring material used to protect components from the plasma inside a fusion reactor. Fusion requires hydrogen isotopes to reach millions of degrees. Tungsten, the metal with the highest melting point, holds promise to withstand extreme temperatures at the edge of this reaction, yet it is brittle and difficult to machine. The ORNL team is using an additive manufacturing technique called electron beam melting to build innovative tungsten fusion components with complex, unique geometries that can’t be made through traditional manufacturing. “The electron beam allows us to better control the heat distribution as tungsten is printed layer by layer,” said ORNL’s Betsy Ellis who led the initial experiments. “After more testing, this method may result in a better quality, full-density structure that’s less prone to cracking.” [Contact: Sara Shoemaker, (865) 576-9219; shoemakerms@ornl.gov]

 

Video: https://www.youtube.com/watch?v=IqNVjedrpxw&feature=youtu.be

 

Caption: Using electron beam melting, ORNL researchers are building innovative tungsten fusion components with complex, unique geometries that can’t be made through traditional manufacturing. The electron beam allows for better control of heat distribution as tungsten is 3D printed layer by layer. Credit: Betsy Ellis/Oak Ridge National Laboratory, U.S. Dept. of Energy

 

Climate—Energy demand shuffle

 

A detailed study by Oak Ridge National Laboratory estimated how much more—or less—energy United States residents might consume by 2050 relative to predicted shifts in seasonal weather patterns across the country. ORNL’s Deeksha Rastogi and colleagues used a series of sophisticated climate models run on supercomputing resources at ORNL to estimate changes in household energy demand over a 40-year period. They found that prolonged periods of increased temperatures are expected to drive a rise in electricity needs while shorter, milder cold seasons could reduce natural gas demand. The team’s paper also posits that climate shifts could impact a projected decrease in residential energy demand in some rural areas. “Our results provide a highly comprehensive look at residential energy consumption that we hope will influence future analysis to understand residents’ choices and behavior relative to climate and socioeconomic conditions,” Rastogi said. [Contact: Sara Shoemaker, (865) 576-9219; shoemakerms@ornl.gov]

 

Images: https://www.ornl.gov/sites/default/files/2019-07/Summer_CDD_Change_ORNL.gif

and https://www.ornl.gov/sites/default/files/2019-07/Winter_HDD_Change_ORNL.gif

 

Caption: A detailed study of climate models at Oak Ridge National Laboratory estimated how much more, or less, energy United States residents might consume over the summer and winter months relative to predicted shifts in seasonal weather patterns across the country. The study was projected through the year 2050. Credit: Deeksha Rastogi/Oak Ridge National Laboratory, U.S. Dept. of Energy

 

Supercomputing—Galactic winds demystified

 

Using the Titan supercomputer at Oak Ridge National Laboratory, a team of astrophysicists created a set of galactic wind simulations of the highest resolution ever performed. The simulations will allow researchers to gather and interpret more accurate, detailed data that elucidates how galactic winds affect the formation and evolution of galaxies. Brant Robertson of the University of California, Santa Cruz, and Evan Schneider of Princeton University developed the simulation suite to better understand galactic winds—outflows of gas released by supernova explosions—which could help explain variations in their density and temperature distributions. The improved set of galactic wind simulations will be incorporated into larger cosmological simulations. “We now have a much clearer idea of how the high speed, high temperature gas produced by clusters of supernovae is ejected after mixing with the cooler, denser gas in the disk of the galaxy,” Schneider said. —Elizabeth Rosenthal [Contact: Katie Bethea, (865) 576-8039; betheakl@ornl.gov]

 

Image: https://www.ornl.gov/sites/default/files/2019-07/Robertson%5B2%5D.png

 

Caption: A galactic wind simulation depicts the galactic disk composed of interstellar gas and stars, shown in red, and the outflows, shown in blue, captured using Titan and the Cholla astrophysics code. Credit: Evan Schneider/Princeton University and Brant Robertson/UC Santa Cruz.

 

Video: https://www.youtube.com/watch?v=z5lyxPotGkQ&feature=youtu.be

 

Caption: This video visualizes galactic winds driven by star clusters distributed throughout the galactic disk. Credit: Evan Schneider/Princeton University and Brant Robertson/UC Santa Cruz.

 

Clean water—Sunny desalination

 

A new method developed at Oak Ridge National Laboratory improves the energy efficiency of a desalination process known as solar-thermal evaporation. Scientists fashioned tubular devices using nanoengineered graphite foam coated with carbon nanoparticles and a superhydrophobic material that increased the absorption of light energy directly from the sun. The thermal energy was used to heat seawater, producing freshwater vapor that was fed into a condenser to make potable water. The system removed more than 99.5% of salt in simulated seawater and reached 64% solar-thermal conversion efficiency. “Using this improved solar-absorbing material for interfacial water evaporation represents a more efficient use of solar energy,” said ORNL’s Gyoung Jang. The experiment is detailed in the journal Global Challenges. The method can be scaled up into modular systems to provide clean water at remote locations or to serve communities affected by hurricanes or floods. [Contact: Stephanie Seay, (865) 576-9894; seaysg@ornl.gov]

 

Image: https://www.ornl.gov/sites/default/files/2019-07/hydrophopicDesal04.jpg

 

Caption: A new method developed at Oak Ridge National Laboratory improves the energy efficiency of a desalination process known as solar-thermal evaporation. Credit: Andy Sproles/Oak Ridge National Laboratory, U.S. Dept. of Energy