UC Davis graduate student Jeremy Mock inspecting the LUX detector before the chamber was filled with water. Credit: Matt Kapust/Sanford Lab
The Large Underground Xenon (LUX) dark matter experiment, which operates beneath a mile of rock at the Sanford Underground Research Facility in the Black Hills of South Dakota, has completed its silent search for the missing matter of the universe.
The experiment did not find a dark matter particle, but it did eliminate a wide swath of mass ranges where a Weakly Interacting Massive Particle, or WIMP, the leading theoretical candidate for dark matter, might exist, team members said.
UC Davis entomologist Christian Nansen trained some high-tech analysis on coffee beans, showing that brands were not consistent in content. Photo: Kathy Garvey
By Kathy Keatley Garvey
If your particular brand of coffee doesn’t seem to taste the same from week to week or month to month, you may be right. And it’s not you, it’s the coffee beans.
Agricultural entomologist Christian Nansen of the UC Davis Department of Entomology and Nematology and four colleagues analyzed 15 brands of roasted coffee beans, purchased at an area supermarket on two dates about six months apart, and using hyperspectral imaging technology, found “they were all over the board.”
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.
Update May 4: This event is now free of charge for all. RSVPs are requested.
By Becky Oskin
The first lecture in new Winston Ko Frontiers in Mathematical and Physical Sciences Public Lecture series will take place May 9. Veronika Hubeny will discuss modern understanding of black holes, and the remaining mysteries. Her talk, “Illuminating Black Holes,” begins at 5 p.m. on Monday, May 9, in the UC Davis Conference Center.
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.
Contributed by the LUX Collaboration
The Large Underground Xenon (LUX) dark matter experiment, which operates nearly a mile underground at the Sanford Underground Research Facility (SURF) in the Black Hills of South Dakota, has already proven itself to be the most sensitive dark matter detector in the world. Now, a new set of calibration techniques employed by LUX scientists has again dramatically improved its sensitivity.
Researchers with LUX are looking for WIMPs, weakly interacting massive particles, which are among the leading candidates for dark matter.
By Becky Oskin
College students in the STEM fields could see sizable savings thanks to a $600,000 grant awarded to an open source textbook project developed at the University of California, Davis.
The ChemWiki project recently received $600,000 from the National Science Foundation to support further expansion of its open source textbooks into fields including statistics, math, geology, physics, biology and solar energy.
Digital course materials are steadily climbing in use in response to textbook cost concerns, according to an annual survey released in July by the National Association of College Stores. In August, the University of Maryland announced plans to completely eliminate print textbooks this academic year.
The sun, as seen in neutrinos captured by the Super-K experiment in Japan (R. Svoboda and K. Gordan).
Robert Svoboda contributed to Nobel-winning neutrino experiments
By Becky Oskin
Billions of mysterious particles called neutrinos bombard your body every day. But catching even one neutrino is a huge effort. Nearly all neutrinos pass through people — and even our planet Earth — without a trace.
“There are 65 million neutrinos going through your thumbnail every second,” said Robert Svoboda, a UC Davis physics professor who has studied neutrinos for more than 25 years. “Only one will stop in your body during your lifetime.”
An exotic, swirling object with the sci-fi name of a “magnetic skyrmion” could be the future of nanoelectronics and memory storage. Physicists at UC Davis and the National Institute of Standards and Technology (NIST) have now succeeded in making magnetic skyrmions, formerly found at temperatures close to absolute zero, at room temperature.
“This is a potentially new way to store information, and the energy costs are expected to be extremely low,” said Kai Liu, professor of physics at UC Davis and corresponding author of a paper on the work, published in the journal Nature Communications Oct. 8.
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.