- Number 403 |
- December 16, 2013
A unique inside look at the electronic structure of a highly touted metal-organic framework (MOF) as it is adsorbing carbon dioxide gas should help in the design of new and improved MOFs for carbon capture and storage. Researchers at DOE’s Lawrence Berkeley National Laboratory (Berkeley Lab) have recorded the first in situ electronic structure observations of the adsorption of carbon dioxide inside Mg-MOF-74, an open metal site MOF that has emerged as one of the most promising strategies for capturing and storing greenhouse gases.
MOFs are molecular systems consisting of a metal oxide center surrounded by organic molecules that form a highly porous three-dimensional crystal framework with a sponge-like capacity for adsorbing greenhouse gases. In a study supported by Berkeley’s Energy Frontier Research Center, the team used Near Edge X-ray Absorption Fine Structure (NEXAFS) at Berkeley Lab’s Advanced Light Source (ALS) to obtain what are believed to be the first ever measurements of chemical and electronic signatures inside of a MOF during gas adsorption.
Unexpected behavior in ferroelectric materials explored by researchers at DOE’s Oak Ridge National Laboratory supports a new approach to information storage and processing.
Ferroelectric materials are known for their ability to spontaneously switch polarization when an electric field is applied. Using a scanning probe microscope, the ORNL-led team took advantage of this property to draw areas of switched polarization called domains on the surface of a ferroelectric material. To the researchers’ surprise, when written in dense arrays, the domains began forming complex and unpredictable patterns on the material’s surface.
“When we reduced the distance between domains, we started to see things that should have been completely impossible,” said ORNL’s Anton Ievlev, the first author on the paper published in Nature Physics. “All of a sudden, when we tried to draw a domain, it wouldn’t form, or it would form in an alternating pattern like a checkerboard. At first glance, it didn’t make any sense. We thought that when a domain forms, it forms. It shouldn’t be dependent on surrounding domains.”
Scientists at DOE’s Pacific Northwest National Laboratory, FEI Company, and DOE’s Argonne National Laboratory obtained a definitive view of a pristine cathode made of lithium, nickel, manganese, and oxygen. Controversy has encircled this cathode, abbreviated LMNO. Some state it’s a solid solution; others, a composite. The team, using a suite of tools, determined the material is actually a composite with tightly integrated phases. Further, they found the surface contains high levels of nickel and low levels of oxygen and electron-rich manganese.
“If we want to improve the cycle life and capacity of the layered cathode, we must have this type of clarity around the atomic structure,” said Dr. Nigel Browning, the Chief Science Officer of PNNL’s Chemical Imaging Initiative and a microscopy expert who worked on the study.
Scientists at ETH Zurich and IBM Research, in collaboration with the Technical University of Munich and DOE's Lawrence Livermore National Laboratory, have set a new record in supercomputing in Fluid Dynamics using 6.4 million threads on LLNL's 96 rack Sequoia IBM BlueGene/Q, one of the fastest supercomputers in the world.
The record for a high performance computing calculation, set on Lawrence Livermore National Laboratory's Sequoia supercomputer, was awarded the Gordon Bell Prize for peak performance at SC13 in Denver, Colo.
Lawrence Livermore computer scientists Adam Bertsch, Blue Gene Systems lead, and Scott Futral, group leader for the HPC development environment, also were members of the winning team. Livermore Computing enabled the achievement of this simulation on Sequoia.
Scientists at DOE's Los Alamos National Laboratory have advanced a Magnetic Resonance Imaging (MRI) technology that may provide a breakthrough for screening liquids at airport security. They’ve added low-power X-ray data to the mix, and as a result have unlocked a new detection technology. Funded in part by the Department of Homeland Security’s Science and Technology Directorate, the new system is named MagRay.
The goal is to quickly and accurately distinguish between liquids that visually appear identical. For example, what appears to be a bottle of white wine could potentially be nitromethane, a liquid that could be used to make an explosive. Both are clear liquids, One would be perfectly safe on a commercial aircraft, the other would be strictly prohibited. How to tell them apart quickly without error at an airport security area is the focus of Michelle Espy, Larry Schultz and their team.