By Becky Oskin
Solar cells made from perovskites have sparked great excitement in recent years because the crystalline compounds boast low production costs and high energy efficiencies. Now UC Davis scientists have found that some promising compounds — the hybrid lead halide perovskites — are chemically unstable and may be unsuited for solar cells.
“We have proven these materials are highly unlikely to function on your rooftop for years,” said Alexandra Navrotsky, interdisciplinary professor of ceramic, earth, and environmental materials chemistry at UC Davis and director of the Nanomaterials in the Environment, Agriculture, and Technology (NEAT) organized research unit.
Our electronic devices are based on what happens when different materials are layered together: “The interface is the device,” as Nobel laureate Herbert Kroemer famously claimed over 40 years ago. Right now, our microchips and memory devices are based on the movement of electrons across and near interfaces, usually of silicon, but with limitations of conventional electronics become apparent, researchers are looking at new ways to store or process information. These “heterostructures” can also find applications in advanced batteries and fuel cells.
Now physicists at UC Davis have observed what’s going on at some of these interfaces as oxygen ions react with different metals, causing drastic changes in magnetic and electronic properties.
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How many projects can you work on at the same time, before losing efficiency? There are many reasons to get involved in multiple projects – impress your boss, gain personal satisfaction, help out colleagues or just because you’re interested. But at some point, there must be one project too many.
“There is a limit,” said Bogdan Vasilescu, postdoctoral researcher in the DECAL lab at the UC Davis Department of Computer Science. “Multitasking fills time that’s otherwise unused, but there is a limit at four or five projects in a week.”
Within just a few years, we’ve got used to controlling devices by swiping, scrolling or tapping our fingers on a touch screen. But soon you might not even have to touch anything at all to check your email or play a video – just wave your hand in the air, thanks to ultrasonic technology from Chirp Microsystems, a startup company founded in 2013 by researchers from UC Davis and UC Berkeley.
Chirp’s technology is “disruptive” in the ultrasound area, said David Horsley, professor of electrical and computer engineering at UC Davis and co-founder of the company. Chirp’s ultrasound transducers are smaller and operate with much lower power needs than any currently available.
A new virus-killing peptide springs from an unexpected source: another virus, Hepatitis C.
Now biomedical engineers at UC Davis and Nanyang Technological University, Singapore show how the HCV alpha-helical (AH) peptide can make holes in the types of membranes that surround viruses. The work is published Jan. 5 in Biophysical Journal.
HCV-AH is known to be active against a wide range of viruses including West Nile, dengue, measles and HIV.
The HCV-AH peptide appears to target an Achilles’ heel common to many viruses, most likely a property of the lipid coating or envelope, said study author Atul Parikh, professor of biomedical engineering at UC Davis. That means that it’s less likely that viruses can readily evolve to become resistant to the peptide.
By Pat Bailey
As 2015 draws to a close, a team of UC Davis undergraduates can look back with pride and a sigh of relief on one of the most grueling but rewarding experiences of their college career.
Students Gabriel Freund, Muntaha Samad, Andrew Shepherd, Logan Vinson and Joanne Wu, were selected last spring as members of UC Davis’ 2015 iGEM (International Genetically Engineered Machines) team. They were joined by Andrew Michelmore, who is from Davis but attends Santa Clara University.
Gabriel Freund in the lab
By AJ Cheline
A team of researchers from the University of California, Davis and the University of Washington have demonstrated that the conductance of DNA can be modulated by controlling its structure, thus opening up the possibility of DNA’s future use as an electromechanical switch for nanoscale computing. Although DNA is commonly known for its biological role as the molecule of life, it has recently garnered significant interest for use as a nanoscale material for a wide-variety of applications.
By Holly Ober
Thermal ablation with magnetic resonance–guided focused ultrasound surgery (MRgFUS) is a noninvasive technique for treating fibroids and cancer. New research from UC Davis shows that combining the technique with chemotherapy can allow complete destruction of tumors in mice.
MRgFUS combines an ultrasound beam that heats and destroys tissue with a magnetic resonance imaging to guide the beam and monitor the effects of treatment. The effectiveness of the treatment can be limited by the need to spare normal tissue or critical structures on the tumor margins, as well as the need to eliminate micrometastases.
By Kat Kerlin
It requires roughly the same level of greenhouse gas emissions to extract shale oil as it does to extract conventional crude oil, according to a pair of studies by UC Davis and Stanford University released this week by the U.S. Department of Energy’s Argonne National Laboratory.
The research analyzed the Eagle Ford shale play in Texas and the Bakken play in North Dakota. These plays are shale formations with low permeability that must be hydraulically fractured to produce oil and gas.
The Eagle Ford Shale in Texas is one of the largest oil and gas producing regions in the country.
The National Science Foundation will award almost $5 million over five years to UC Davis to include the large earthquake-simulating centrifuge at the Center for Geotechnical Modeling as part of the new Natural Hazards Engineering Research Infrastructure program.
The geotechnical centrifuge at UC Davis is the largest of its kind in the world. It is used for scale model experiments on the effect of earthquakes on soils and buildings.