Modeling – Predicting water quality
A new modeling capability developed at Oak Ridge National Laboratory incorporates important biogeochemical processes happening in river corridors for a clearer understanding of how water quality will be impacted by climate change, land use and population growth.
Researchers used high-performance computing and the award-winning Amanzi-ATS software to include biogeochemical reactions in microbially-active zones near streams in models that track the movement of dissolved chemicals in river networks. These reactions have a major influence on the cycling of carbon, nutrients and contaminants at basin scales. The new multiscale model better tracks water quality indicators such as nitrogen and mercury levels.
“To build a next-generation modeling capability to address water quality issues, we needed a new multiscale framework that allows us to incorporate fundamental understanding of key processes and how those fine-scale processes manifest at much larger scales,” ORNL’s Scott Painter said.
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Caption: An ORNL research team has incorporated important effects from microbially active hot spots near streams into models that track the movement of nutrients and contaminants in river networks. The integrated model better tracks water quality indicators and facilitates new science. Credit: Andy Sproles/ORNL, U.S. Dept. of Energy
Neutrons – 'Stretchier' alloys
Researchers at Oak Ridge National Laboratory have developed a method of adding nano structures to high-entropy metal alloys, or HEAs, that enhance both strength and ductility, which is the ability to deform or stretch under tensile stress without failing.
The results, published in Science, open a promising pathway for tailoring HEA properties using small gradient structures to produce improved high-performance metals for a wide range of applications.
Conventional metallic materials, including HEAs (metals composed of five or more elements) become less ductile or more brittle as their strength increases.
The scientists used neutron diffraction methods at ORNL’s Spallation Neutron Source to confirm tiny defect features, called stacking faults, form easily in an HEA compared to conventional fine-grained alloys.
“The stacking faults enhanced the test alloy’s plasticity while also contributing to increased strength and hardening,” said ORNL’s Ke An. “Industries that could greatly benefit include automotive, power distribution and aerospace.”
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Caption: ORNL researchers used neutrons at the lab’s Spallation Neutron Source to analyze modified high-entropy metal alloys with enhanced strength and ductility, or the ability to stretch, under high-stress without failing. Credit: Rui Feng/ORNL, U.S. Dept. of Energy
Grid – RAPID reinforcement
Oak Ridge National Laboratory, University of Tennessee, Knoxville, and University of Central Florida researchers released a new high-performance computing code designed to more efficiently examine power systems and identify electrical grid disruptions, such as power outages.
The Resilient Adaptive Parallel sImulator for griD, or RAPID, relies on a novel parallel in time, or “parareal,” algorithm that divides calculations into smaller time intervals, then completes them simulataneously on different processors to streamline traditionally time-consuming simulations.
RAPID also uses adaptive model reduction, which reduces computational demand by focusing only on areas near a disruption. The code is compatible with various architectures and could eventually help predict grid dynamics and assess algorithms for the integrated transmission and distribution network as fast as or faster than real time.
“The goal is to run these simulations as fast as possible and provide information to grid operators about how to address problems,” said ORNL’s Srdjan Simunovic. — Elizabeth Rosenthal
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Caption: An open-source code developed by an ORNL-led team could provide new insights into the everyday operation of the nation’s power grid. Credit: Pixabay
Data – Mountainous water towers
New data hosted through the Atmospheric Radiation Measurement Data Center at Oak Ridge National Laboratory will help improve models that predict climate change effects on the water supply in the Colorado River Basin.
Mountains are natural water towers that collect the snowpack that becomes drinking water for millions of people. ARM’s goal is to collect data needed to advance understanding of complex land-water-atmosphere interactions in these regions and improve model predictions of future climate and water availability.
More than four dozen instruments measure atmospheric factors affecting the water cycle and climate near Crested Butte, Colorado, as part of ARM’s SAIL project. These data will be integrated with other measurements taken at and below the surface to provide a clearer picture of key processes.
“The ARM data services team is making terabytes of data accessible to facilitate the multi-institutional effort investigating the hydrologic processes that influence climate and the availability of critical water resources,” said ORNL’s Giri Prakash.
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Caption: Instruments gather atmospheric data at the Colorado site as part of the Atmospheric Radiation Measurement User Facility’s SAIL campaign. SAIL integrates expertise and capabilities from Department of Energy national laboratories, the U.S. Geological Survey, the National Oceanic and Atmospheric Administration and the Rocky Mountain Biological Laboratory. Credit: DOE ARM user facility
Manufacturing – Strong, stable alloys
Oak Ridge National Laboratory researchers have additively manufactured a lightweight aluminum alloy and demonstrated its ability to resist creep or deformation at 300 degrees Celsius.
Materials that can perform under high pressure, high temperature environments are needed for automotive, aerospace, defense and space applications. The alloy, which combines aluminum with cerium and other metals, was printed using a laser powder bed system that deposits one thin layer of material at a time for precise results. Researchers printed pistons made of the alloy for deployment inside of a full-scale engine.
“Using powder-bed 3D printing allowed the alloy to rapidly solidify into fine, stable strengthening particles in the microstructure, resulting in the remarkable high-temp creep resistance we measured,” ORNL’s Ryan Dehoff said. “We expected notable improvements, but were surprised by how strong and stable these alloys proved to be.”
The pistons will undergo additional testing inside of a four-cylinder, turbocharged engine.
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ORNL researchers used a laser power bed manufacturing technique to 3D print a lightweight aluminum and cerium-based alloy that can withstand temperatures up to 300 degrees Celsius, proving high strength and durability for automotive, aerospace and defense applications. Credit: ORNL, U.S. Dept. of Energy
Method of Research
Subject of Research
Gradient-cell–structured high-entropy alloy with exceptional strength and ductility
Article Publication Date