- Number 387 |
- April 29, 2013
-
New materials to capture methane
Scientists at DOE's Lawrence Livermore National Laboratory and UC Berkeley have discovered new materials to capture methane, the second highest concentration greenhouse gas emitted into the atmosphere.
Methane is a substantial driver of global climate change, contributing 30 percent of current net climate warming. Concern over methane is mounting, due to leaks associated with rapidly expanding unconventional oil and gas extraction, and the potential for large-scale release of methane from the Arctic as ice cover continues to melt and decayed material releases methane to the atmosphere. At the same time, methane is a growing source of energy, and aggressive methane mitigation is key to avoiding dangerous levels of global warming. -
The nanostructure of edible fats
Researchers at DOE's Brookhaven are using the National Synchrotron Light Source (NSLS) to categorize the many facets of fat crystals. They’ve learned that the distribution and directionality of these crystal nanostructures affects the flavor and texture of foods.
From butter in croissants to cocoa solids in chocolate, edible fats pack a flavor punch that delights like no other macronutrient we consume. Fats are the most energy dense macronutrients, providing more than twice as many kilocalories per gram as proteins or carbohydrates, which may be the reason we’ve developed a taste for them. Fats are an efficient method of fueling a surviving species, but what gives them their oh-so-delicious disposition?
As explained in a review paper by NSLS user Alejandro Marangoni, published in Soft Matter, fats are made up of fractal-like crystalline structures, which give rise to properties such as flavor, texture, meltability, and mouthfeel. For example, six different forms of crystal structure have been identified for cocoa butter. But only one form will turn out chocolate that tastes and feels good to eat. -
Small and viscous: New method measures nanoparticle viscosity
For the first time, scientists measured the chemical diffusivity and viscosity of atmospheric organic particles, thanks to a new approach from scientists at DOE's Pacific Northwest National Laboratory, University of Washington, and Imre Consulting. The team doped atmospherically important organic nanoparticles, known as secondary organic aerosol (SOA), with tracer molecules and measured their diffusion rate as they slowly worked their way out of the particles. Knowing the diffusion rate, the scientists calculated the particle's viscosity.
"Over the past two years, we have shown that long-standing assumptions about the most fundamental properties of SOA particles – phase and volatility – are wrong. Here, for the first time, we quantify chemical diffusivity in SOA particles and show that SOA viscosity is larger – a million times higher – than assumed," said lead author Dr. Alla Zelenyuk, physical chemist at the national laboratory. -
Afterlife for electric vehicle batteries
Once they've finished powering electric vehicles for hundreds of thousands of miles, it may not be the end of the road for automotive batteries, which researchers believe can provide continued benefits for consumers, automakers and the environment.
Five used Chevrolet Volt batteries are at the heart of the Department of Energy Oak Ridge National Laboratory's effort to determine the feasibility of a community energy storage system that would put electricity onto the grid. Over the next year, researchers from ORNL, General Motors and the ABB Group will conduct studies and compile data using a first-of-its-kind test platform officially commissioned today.