Lab Report

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The Lab Report is a weekly compendium of media reports on science and technology achievements at Lawrence Livermore National Laboratory. Though the Laboratory reviews items for overall accuracy, the reporting organizations are responsible for the content in the links below.

Oct. 25, 2019

bennu

Bennu is a massive asteroid that has a remote chance of crossing paths with Earth more than a century from now.

 

Asteroid’s looks could kill

Like a scene out of the blockbuster movie "Armageddon," Lawrence Livermore National Lab researchers have been developing a plan to deflect a killer asteroid if one should ever be on a collision course with Earth.

In the movie, Bruce Willis leads a team of astronauts and oil drillers on a mission to deflect a massive asteroid as it approaches Earth by burying a nuclear bomb deep within its surface and detonating it to alter its course.

In real life, the researchers — a team made up of scientists from Lawrence Livermore, NASA’s Goddard Space Flight Center, Los Alamos National Laboratory and the National Nuclear Security Administration — say that would not work.

“The whole purpose of studies like this is to help us shorten the response timeline if we were to see something coming at us,” said physicist Megan Bruck Syal, who is the LLNL planetary defense team lead. “We don’t want to have to scramble to figure out whether to use an impactor or a nuclear device on a particular asteroid. These studies help us define those thresholds.”

chu

Livermore Graduate Scholar and chemist Fanny Chu is part of a team that found that any single hair from anywhere on the human body can be used to identify a person. Photo by Julie Russell/LLNL

From a single hair

Any single hair from anywhere on the human body can be used to identify a person.

This conclusion is one of the key findings from a nearly yearlong study by a team of researchers from Lawrence Livermore National Laboratory’s Forensic Science Center (FSC) and Michigan State University.

The team’s study could provide an important new avenue of evidence for law enforcement authorities in sexual assault cases.

In 2016, FSC scientists developed the first-ever biological identification method that exploits the information encoded in the proteins of human hair from people’s heads. This forensic science breakthrough provides a second science-based, statistically validated way to identify people and link individuals to evidence in addition to DNA profiling.

The team discovered that the protein content of pubic hair is significantly higher than head and arm hair and noted this means more protein markers can be found, making the individual profiles more discriminating.

volcano

LLNL researchers are using plasma physics to predict the characteristics of hazardous ash plumes like those spewed from Eyjafjallajokull volcano in Iceland. Photo courtesy of Oddur Sigurðsson/ Iceland Meteorological Office

Volcanoes rise from the ashes

A research team at Lawrence Livermore National Laboratory (LLNL) used plasma physics to investigate how the addition of volcanic ash affects the characteristics of the volcanic standing shock wave and came up with a new discovery.

"Our simulations show that volcanic ash modifies the height, width and lifetime of the standing shock wave," said Jens von der Linden, LLNL physicist and lead researcher on the project.

Volcanoes are ruptures in the crust of a planet and are prevalent throughout the solar system. On Earth, volcanoes are generally found along the boundaries of colliding or diverging tectonic plates or on holes in our planet's crust called hotspots.

During a volcanic eruption, there is an outflow of high-pressure gas through a nozzle or vent. This causes what scientists describe as a standing shock wave to form in the near-vent region. A shock wave is a disturbance that moves faster than the speed of sound, like a sonic boom, and causes a buildup of density as it propagates. A standing shock wave is one that remains stationary, so the buildup of density remains in place. Although these standing shock waves have been previously explored in the context of rocket plumes and fuel injection, there are relatively few studies involving the outflow of a gas containing fine particulates, especially volcanic ash.

gold

LLNL researchers have found that nanoporous gold can be a good fuel cell catalyst.

 

Poring through gold catalysts

Lawrence Livermore’s Juergen Biener is a member of the Integrated Mesoscale Architectures for Sustainable Catalysis (IMASC) Energy Frontier Research Centre and focuses on studying hierarchical nanoporus structures.

He says that nanoporous alloys can be very stable, but under some circumstances gases and liquids can only travel slowly through them, diminishing their benefits. Researchers therefore want to mimic ‘hierarchical’ nanoporous structures. 

Biener compares the widest pores to freeways but notes that current production methods would create a nonsensical road system. “Either you are not allowed to put any freeways in the system, or they’re just randomly placed without planning. That’s the structure you get with traditional synthetic approaches to porous materials. In nature, the lung, your kidneys, liver, they all depend on very effective mass transport. Typically, that involves hierarchical pore systems.”

Biener and his LLNL colleagues have 3D printed such structures using gold and silver-based inks. Their starting structure was similar to a woodpile, with solid sections stacked with micrometer-scale ‘freeway’ channels between them. The scientists then etched away, or dealloyed, the silver with nitric acid to create nanoscale pores, and used the resulting catalyst to oxidize methanol. “Pre-Columbian cultures used something similar to make metal objects to appear made out of pure gold, whereas they were made out of a copper–gold alloy,” Biener explained. “It’s commonly used to create nanoporosity, but the resulting structure has poor mass transport properties.”

In LLNL’s digitally designed catalyst, the remaining 2 atom percentage of silver enables the oxidation reaction, making this material a hierarchically structured catalyst.

moon

New research finds evidence of an ancient impact 4.3 billion years ago on the moon, churning rock up to the lunar surface. Image courtesy of NASA

agu

Many moons ago

An Apollo 16 lunar rock sample shows evidence of intense meteorite bombardment on the moon 4.3 billion years ago, according to new research. The results provide new insights for the moon’s early history, showing lunar impacts were common throughout the moon’s formation than previously thought.

When the moon first formed, its surface was covered in a sea of molten rock called the lunar magma ocean. This magma ocean eventually cooled and formed the rocks that make up the lunar crust and mantle.

Lawrence Livermore scientists analyzed a moon rock from the Apollo 16 mission and found the rock cooled quicker than expected. The results suggest that 4.3 billion years ago a previously unidentified impact event forced the rock from the depths of the slowly cooling lunar crust to the surface.

“Something hit the moon while the rocks were still at high temperatures, excavated the rock from depths in the lunar crust, and then it cooled quickly after that,” said Naomi Marks, an LLNL geochemist.

Many planetary scientists had previously accepted the idea that the moon had a relatively peaceful existence following its creation until the Late Heavy Bombardment, a period when the moon was intensely pelted by meteorites and asteroids 4.0 billion to 3.8 billion years ago. But scientists have been questioning the accuracy of this theory. The new results add to growing evidence that the theory may be incorrect by identifying a major impact outside of the theory’s timeframe.