LAB REPORT

When a lightning storm struck the parched Diablo mountain range in August 2020, igniting fires that turned the skies an apocalyptic shade of orange, the Governor’s Office activated current Oakland Fire Department Assistant Chief Christopher Foley to face the fire’s multiple fronts. “Most of the state was burning,” said Foley.

Often fueled by dry lightning, multi-ignition wildfires continue to represent a severe threat and a significant challenge to firefighting efforts and firefighter safety. But a new model from the Lawrence Livermore National Laboratory and UC Irvine could be a crucial new tool — offering a new understanding of multi-ignition fires and the weather systems they create.

“We see a clear trend for those more extreme fires over western U.S. over the recent one to two decades. But why?” said Qi Tang, LLNL scientist and author of the study. “One possible reason is that those multi-ignition fires occur when there’s dry lightning. When there’s a system driving many lightnings, they can start fires in close-by areas.”

Lawrence Livermore National Laboratory’s free public lecture series returns February 7–28 at Las Positas College in Livermore, Calif., with four Saturday sessions for middle- and high-school students. This year’s theme is “Computing the Future.”

The series opens Feb. 7 with “Cosmic Treasure Hunt: Finding Stardust in Meteorites.” That session will dig into how ancient grains preserved in meteorites reveal information about the stars that formed our solar system. Future sessions turn to computing-intensive research.

The lecture slated for Feb. 14 on AI and supercomputing in biology will be presented by Dan Faissol, who leads LLNL’s work on the GUIDE (Generative Unconstrained Intelligent Drug Engineering) platform. The Feb. 28 quantum computing session will be presented by LLNL scientists Sean O’Kelley and Kristi Beck. The Feb. 21 session covers how graphics processing units, originally developed for video games, are at the heart of the AI wave. GPUs now run atmospheric simulations up to 100 times faster.

In a recent study published in Nano Letters, researchers from Lawrence Livermore National Laboratory (LLNL) and the University of Maryland reported their results, demonstrating the synthetic “molecular gate” mechanism that emulates the behavior of barrel-shaped proteins known as porins, creating pores in cell membranes to allow specific molecules to pass through.

When water and ions traverse channels that are merely a nanometer in width, they exhibit peculiar behaviors. Within these confined spaces, water molecules align in a single file. This alignment compels ions to release some of the water molecules that typically surround them, leading to the distinctive physics of ion transport.

Biological channels are particularly skilled at this phenomenon, frequently orchestrating the opening and closing of channels to facilitate intricate functions such as signaling within the nervous system.

The researchers used a chemical method to fabricate exceptionally short, fluorescent nanotubes featuring specific lid-like structures at their ends.

A project at Lawrence Livermore National Laboratory (LLNL) and Sandia National Laboratories has identified a new way to optimize the quality of 3D-printed thermoplastics.

Described in Science, the technique varies the intensity of the light used in an additive fabrication operation to influence the crystallinity of the printed material.

The approach has been named crystallinity regulation in additive fabrication of thermoplastics (CRAFT), and could have implications for advanced manufacturing, soft robotics and information storage, among other applications.

“A classic example of crystallinity is the difference between high-density polyethylene like a milk jug, and low-density polyethylene like plastic bags,” said Johanna Schwartz from LLNL. “The bulk property difference in these two forms of polyethylene stems largely from differences in crystallinity.”

However, contemporary manufacturing strategies, from injection molding to traditional 3D printing, result in monolithic objects unable to spatially encode crystallinity, noted the project in its paper.

When materials are compressed, their atoms are forced into unusual arrangements that do not normally exist under everyday conditions. These configurations are often fleeting: when the pressure is released, the atoms typically relax back to a stable low-pressure state. Only a few very specific materials, like diamond, retain their high-pressure structure after returning to room temperature and atmospheric pressure.

But locking those atomic arrangements in place under ambient conditions could create new classes of useful materials with a wide range of potential applications. One particularly compelling example is energetic materials, which are useful for propellants and explosives.

In a study published in Communications Chemistry, researchers at Lawrence Livermore National Laboratory (LLNL) identified a first-of-its-kind carbon dioxide-equivalent polymer that can be recovered from high-pressure conditions.

“A polymeric form of carbon dioxide stores far more energy than ordinary carbon dioxide because its atoms are locked into a dense, covalently bonded network,” said LLNL scientist and author Stanimir Bonev.