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.

Jan. 27, 2017

asteroid
Artist's impression of a near-Earth asteroid passing by Earth. Credit: ESA

Deflecting asteroids looks bright

When you need to save Earth from an incoming asteroid, try shooting at its bright spots. A new analysis of fragments of the Chelyabinsk meteor, which exploded over Russia in 2013, suggests that firing something at an asteroid's lighter areas may be the best way to deflect it.

The team looked at the three rocks making up the Chelyabinsk object: a pale and relatively pristine material with a grainy texture, a darker substance with opaque veins and another dark material filled with droplet-shaped bits of metal. The team made tiny indentations in each with a diamond-tipped probe to measure hardness and stiffness.

Those properties influence the choice of target and how much the asteroid's path could be shifted. "There are pieces that fly off a little bit like the droplets of fluid if you throw a rock into a pond," says Paul Miller of Lawrence Livermore National Laboratory. "[Aiming at] that material actually gives you bonus push, bonus momentum."

As a target, the pale material won out: It was softer, so it can "splash up," as Miller describes, more easily. That same rock is common in near-Earth asteroids and can be detected from afar using spectral analysis.

climate_change
Even though temperatures vary from year to year, the trend is upward in the long term. Credit: kwest/Shutterstock.com

Climate change trending

Scientists say the run of record-breaking temperatures doesn't mean that every year will be hotter than the last. From year to year, temperatures may cycle from hotter to cooler and back again. However, without serious cuts in greenhouse-gas emissions, the world will get much warmer over the long term.

Several lines of evidence bolster the case that human-generated greenhouse gases are to blame for the long-term upward trend in temperatures, said Benjamin Santer, a climatologist at the Lawrence Livermore National Laboratory.

Santer said with data from satellites and modern weather balloons, he and colleagues recently observed the signature of greenhouse gas warming that meteorologist Syukuro Manabe predicted back in the '60s.

moonshot
ATOM teammates (from left) Stacie Calad-Thomson, Jim Brase, Jason Paragas and John Baldoni stand among new supercomputing assets at Lawrence Livermore National Laboratory, which will be used in drug research. Photo by Julie Russell/LLNL

New launch for cancer moonshot

GlaxoSmithKline (GSK) is turning its attention to drug discovery, where it is hoping that a promising approach of applying supercomputing to huge data sets will allow it to move from target identification to a molecule ready for the clinic in just one year.

GSK has partnered with Department of Energy labs headed by Lawrence Livermore National Laboratory and the National Cancer Institute (NCI) to move in that direction.

The partnership, called Accelerating Therapies for Opportunities in Medicine (ATOM), will begin by putting DOE's supercomputing powerhouse to work on data from GSK and NCI, taking advantage of the drug company's expertise in chemistry and biology as a framework in pioneering applications of deep learning for drug research.

ATOM is a part of the Cancer Moonshot initiative developed by former Vice President Joe Biden to accelerate cancer research including making more therapies available to more patients, while also improving the ability to prevent cancer and detect it at an early stage.

foam
Microstructures of two different foam materials. At left, a traditional open-cell stochastic foam, and a right, a 3D-printed foam with the face-centered tetragonal lattice structure.

Not your average foam

Lawrence Livermore material scientists have found that 3D-printed foam works better than standard cellular materials in terms of durability and long-term mechanical performance.

Foams, also known as cellular solids, are an important class of materials with applications ranging from thermal insulation and shock-absorbing support cushions to lightweight structural and flotation components. Such material is an essential component in many industries, including automotive, aerospace, electronics, marine, biomedical, packaging and defense.

Traditionally, foams are created by processes that lead to a highly non-uniform structure with significant dispersion in size, shape, thickness, connectedness and topology of its constituent cells. As an improved alternative, scientists at the additive manufacturing lab at Lawrence Livermore recently demonstrated the feasibility of 3D printing of uniform foam structures through a process called direct-ink-write.

hyrdogen
This is a schematic illustration of a photoelectrochemical cell for water splitting. The absorption of photons on the photoanode (left) generates electron and hole carriers. The electrons will flow through the circuit to the photocathode and evolve hydrogen (right), while the holes will evolve oxygen (left). Figure courtesy of Peter Allen/the Institute for Molecular Engineering, University of Chicago

Going carbon free

A Lawrence Livermore scientist and collaborators are fine tuning the mechanisms to generate hydrogen from water and sunlight.

Hydrogen production offers a promising approach for producing scalable and sustainable carbon-free energy. The key to a successful solar-to-fuel technology is the design of efficient, long-lasting and low-cost photoelectrochemical cells (PECs), which are responsible for absorbing sunlight and driving water-splitting reactions.

LLNL's Lawrence Fellow Anh Pham and colleagues reviewed the use of first-principles methods to understand the interfaces between photo absorbers, electrolytes and catalysts in PECs. The team shows that with growing complexity of PEC architectures, understanding the properties of the interfaces between its components is key to predict novel, better-performing materials and eventually to optimize the device performance.