June 26, 2020
Green sands along beaches in the Caribbean could capture billions of tons of carbon dioxide, a move that could help counteract climate change, but a lot of uncertainties remain.
Mineral weathering is one of the main mechanisms the planet uses to recycle carbon dioxide across geological time scales. The carbon dioxide captured in rainwater, in the form of carbonic acid, dissolves basic rocks and minerals — particularly those rich in silicate, calcium and magnesium, like olivine. This produces bicarbonate, calcium ions and other compounds that trickle their way into the oceans, where marine organisms digest them and convert them into the stable, solid calcium carbonate that makes up their shells and skeletons.
The idea of leveraging weathering to combat climate change isn’t new. A handful of projects are now under way. One project uses the ground-down approach, which involves highly reactive minerals produced as a by-product of nickel, diamond and platinum mining. One idea is to simply lay them across a field, add water, and effectively till the slurry. They expect the so-called mine tailings to rapidly draw down and mineralize carbon dioxide from the air, forming a solid block that can be buried. Their models show it could eliminate the carbon footprint of certain mines, or even make the operations carbon negative.
“This is one of the great untapped opportunities in carbon dioxide removal,” says Roger Aines, head of the Carbon Initiative at Lawrence Livermore National Lab. He notes that a cubic kilometer of ultramafic rock, which contain high levels of magnesium, can absorb a billion tons of carbon dioxide.
“We mine rock on that scale all the time,” he says. “There’s nothing else that has that kind of scalability in all the solutions we have.”
A better understanding of the material processes inside the icy giants like Uranus and Neptune can help us understand the most common type of exoplanet.
Experiments reveal that “icy” is much more complicated for ice giants than previously thought. “We found this unusual superionic state for water that exists only at high pressures and temperatures that are similar to what we expect inside Neptune and Uranus,” said Marius Millot, a physicist at Lawrence Livermore National Laboratory. “Superionic ice is a new state of matter.”
Millot led the team of researchers who discovered this previously unknown state of matter. They used first a diamond anvil cell and then Rochester University’s Omega Laser Facility to force the water to crystallize into this new state.
“For water, [superionic ice] is a state where the oxygen atoms that form the H2O molecule that we’re familiar with continue to form a solid lattice, like in ice that we know,” Millot said. “But unlike the ice we know and that is in our ice cubes, in superionic ice the hydrogen is actually free to move around within this lattice of oxygen. Basically, the hydrogen atoms are moving around almost like a fluid within the solid crystal made of the oxygen. It’s a very unusual solid-liquid state.”
At the pressure of an ice giant’s mantle (roughly 200 million atmospheres), superionic ice melts at temperatures near 4,700°C, much hotter than its environment. The team confirmed the ice’s novel crystal structure in later research. “It could be that this superionic ice actually doesn’t melt even inside Neptune and Uranus,” Millot said, and so the planets could be quite solid.
Lawrence Livermore National Laboratory (LLNL) has broken ground on its Exascale Computing Facility Modernization project. It will substantially upgrade the mechanical and electrical capabilities of the Livermore Computing Center. The upgrades will enable the facility to provide exascale-class service (supercomputers capable of at least one quintillion calculations per second) to LLNL, Los Alamos and Sandia.
Commissioned in 2004, LLNL’s computing center has housed some of the world’s largest, fastest and most advanced classified systems, but supporting next-generation high performance machines will require National Nuclear Security Administration facilities to exceed their current capacities for power and cooling. An official groundbreaking ceremony was canceled due to the COVID-19 pandemic, but construction crews have been working to expand the facility’s system capacity.
The upgrades will allow LLNL to optimally run future supercomputers capable of regularly performing the high-fidelity 3D modeling and simulation necessary to meet the increasingly challenging certification requirements of NNSA’s Stockpile Stewardship Program and its mission to enhance the capability of the nation’s nuclear deterrent.
Metastasis accounts for approximately 90 percent of mortality in breast cancer patients. During the last few decades, there has been significant progress in understanding genetic, molecular and signaling mechanisms underpinning cancer cell migration.
Biologists from Lawrence Livermore National Laboratory (LLNL) found another mechanism that affects the maintenance and expansion of malignant cells: electric signals in the tumor microenvironment.
All cells can generate bioelectric signals through their plasma membrane, and therefore naturally exist in our bodies. Cancer growth interferes with local ionic, membrane and epithelium environments, resulting in small electrical changes in the tumor microenvironment.
Electrical fields (EFs) have significant effects on cancer cell migration, but their role as a regulator of cancer progression and metastasis is poorly understood.
Despite the implementation of advanced detection technologies, the prevalence of metastatic breast cancer at initial diagnosis has remained stagnant in the United States since 1975.
The LLNL-University of California, Davis collaborative team used unique probe systems to characterize the electrical properties of cancer cells and how they migrate under an EF. Earlier studies showed that bioelectric characteristics of cancer tissue differs from normal tissue and may change during cancer development.
When stars explode as supernovae, they produce shock waves in the plasma surrounding them. They are so powerful that they can act as particle accelerators that blast streams of particles, called cosmic rays, out into the universe at nearly the speed of light. Yet how they do that has remained something of a mystery.
Now in experiments at the National Ignition Facility (NIF), Lawrence Livermore scientists and collaborators have devised a new way to study the inner workings of astrophysical shock waves by creating a scaled-down version of the shock in the lab. They found that astrophysical shocks develop turbulence at very small scales — scales that can’t be seen by astronomical observations — that helps accelerate electrons at the shock wave before being boosted up to their final velocities.
“It is totally awesome to have determined that electromagnetic fields are generated simply from fast-moving, supersonic, low-density interpenetrating plasma flows,” said LLNL physicist Hye-Sook Park. “It is even more exciting to see the unquestionable shock formation and particle accelerations created in our experiments after working on the subject over a decade.”
Park has been leading the project on both NIF and at the University of Rochester’s Laboratory for Laser Energetics Omega Laser Facility.