Cooking exhaust hoods designed for home kitchens vary widely in their ability to capture and vent away the air pollutants generated by the gas burners on cook stoves, according to a study by two Lawrence Berkeley National Laboratory (Berkeley Lab) scientists. Of seven representative devices they tested, the capture efficiency varied from less than 15 percent to more than 98 percent.
The study, by Woody Delp and Brett Singer of Berkeley Lab’s Environmental Energy Technologies Division, measured their pollutant capture efficiency, sound level generated by their fans, and airflow. Cooking exhaust hoods vent such pollutants as carbon monoxide, nitrogen oxides, formaldehyde, and fine particulates such as soot generated during cooking. (more…)
Berkeley Lab Researchers Observations of Nanorod Crystal Growth Points Way to Next Generation Energy Devices
In the growth of crystals, do nanoparticles act as “artificial atoms” forming molecular-type building blocks that can assemble into complex structures? This is the contention of a major but controversial theory to explain nanocrystal growth. A study by researchers at the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) may resolve the controversy and point the way to energy devices of the future.
Led by Haimei Zheng, a staff scientist in Berkeley Lab’s Materials Sciences Division, the researchers used a combination of transmission electron microscopy and advanced liquid cell handling techniques to carry out real-time observations of the growth of nanorods from nanoparticles of platinum and iron. Their observations support the theory of nanoparticles acting like artificial atoms during crystal growth. (more…)
Berkeley Lab scientists help paint a more complicated picture of the devastating disease
For the past five years, volunteers from the City of Berkeley and surrounding areas have come to Lawrence Berkeley National Laboratory to participate in an ongoing study that’s changing what scientists know about Alzheimer’s disease.
The volunteers, most over the age of 70, undergo what can best be described as a brain checkup. They’re asked to solve puzzles and memorize lists of words. Magnetic resonance imaging (MRI) scans image the structure of their brains in exquisite detail. Functional MRI scans allow scientists to watch portions of their brains light up as they form memories. And Positron emission tomography (PET) scans measure any accumulation of beta-amyloid, a destructive protein that’s a hallmark of Alzheimer’s. (more…)
New approach is a promising first step toward the development of tiny devices that harvest electrical energy from everyday tasks
Imagine charging your phone as you walk, thanks to a paper-thin generator embedded in the sole of your shoe. This futuristic scenario is now a little closer to reality. Scientists from the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) have developed a way to generate power using harmless viruses that convert mechanical energy into electricity.
The scientists tested their approach by creating a generator that produces enough current to operate a small liquid-crystal display. It works by tapping a finger on a postage stamp-sized electrode coated with specially engineered viruses. The viruses convert the force of the tap into an electric charge. (more…)
Berkeley Lab scientists create nanoparticle probes that may lead to a better understanding of diseases
Imagine tracking a deer through a forest by clipping a radio transmitter to its ear and monitoring the deer’s location remotely. Now imagine that transmitter is the size of a house, and you understand the problem researchers may encounter when they try to use nanoparticles to track proteins in live cells.
Understanding how a protein moves around a cell helps researchers understand the protein’s function and the cellular mechanisms for making and processing proteins. This information also helps researchers study disease, which at a cellular level may mean that a protein is malfunctioning, stops being made, or is sent to the wrong part of the cell. But nanoparticle probes that are too big can disrupt a protein’s normal activities. (more…)
Berkeley Lab-led team explores a way to create biofuels, minus the photosynthesis
Is there a new path to biofuels hiding in a handful of dirt? Lawrence Berkeley National Laboratory (Berkeley Lab) biologist Steve Singer leads a group that wants to find out. They’re exploring whether a common soil bacterium can be engineered to produce liquid transportation fuels much more efficiently than the ways in which advanced biofuels are made today.
The scientists are working with a bacterium called Ralstonia eutropha. It naturally uses hydrogen as an energy source to convert CO2 into various organic compounds. (more…)
Berkeley Lab scientists demonstrate the promise of synchrotron infrared spectroscopy of living cells for medical applications
Knowing how a living cell works means knowing how the chemistry inside the cell changes as the functions of the cell change. Protein phosphorylation, for example, controls everything from cell proliferation to differentiation to metabolism to signaling, and even programmed cell death (apoptosis), in cells from bacteria to humans. It’s a chemical process that has long been intensively studied, not least in hopes of treating or eliminating a wide range of diseases. But until now the close-up view – watching phosphorylation work at the molecular level as individual cells change over time – has been impossible without damaging the cells or interfering with the very processes that are being examined.
“To look into phosphorylation, researchers have labeled specific phosphorylated proteins with antibodies that carry fluorescent dyes,” says Hoi-Ying Holman of the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab). “That gives you a great image, but you have to know exactly what to label before you can even begin.” (more…)
Berkeley Lab Researchers Direct the Self-Assembly of Gold Nanoparticles into Device-Ready Thin films
Scientists with the Lawrence Berkeley National Laboratory (Berkeley Lab) and the University of California (UC) Berkeley have directed the first self-assembly of nanoparticles into device-ready materials. Through a relatively easy and inexpensive technique based on blending nanoparticles with block co-polymer supramolecules, the researchers produced multiple-layers of thin films from highly ordered one-, two- and three-dimensional arrays of gold nanoparticles. Thin films such as these have potential applications for a wide range of fields, including computer memory storage, energy harvesting, energy storage, remote-sensing, catalysis, light management and the emerging new field of plasmonics.
“We’ve demonstrated a simple yet versatile supramolecular approach to control the 3-D spatial organization of nanoparticles with single particle precision over macroscopic distances in thin films,” says polymer scientist Ting Xu, who led this research. “While the thin gold films we made were wafer-sized, the technique can easily produce much larger films, and it can be used on nanoparticles of many other materials besides gold.” (more…)
