Toggle light / dark theme

Li and colleagues used a technique called distributed acoustic sensing (DAS), which, while new to the world of seismology, is already used to monitor pipelines and power cables for defects. The method involves sending laser light pulses over optical fibers and measuring the intensity of the signals reflected back from imperfections in the fiber. Slight stretching or contracting of the fiber (say, from an) can change the reflected signals.

Based on the pulse’s time of return, you can pinpoint when and where along the cable the disturbance occurred. Because light gets reflected from thousands of imperfection points along fibers, a kilometers-long stretch of cable can act as thousands of seismometers. This means significantly more seismic data, leading to higher resolution, which allows pinpointing the location of smaller seismic activity.

The Caltech researchers have converted preexisting optical cables into a DAS array. Telecom companies usually lay down more fiber than they need, and the research team taps into some of this “dark” unused fiber. With permission from the California Broadband Cooperative, the team set up a DAS transceiver at one end of a length of fiber-optic cable along the border between California and Nevada.

BANGKOK (AP) — China’s energy and auto giant BYD has announced an ultra fast EV charging system that it says is nearly as quick as a fill up at the pumps.

BYD, China’s largest EV maker, said Monday that its flash-chargers can provide a full charge for its latest EVs within five to eight minutes, similar to the amount of time needed to fill a fuel tank. It plans to build more than 4,000 of the new charging stations across China.

Charging times and limited ranges have been a major factor constraining the switch from gas and diesel vehicles to EVs, though Chinese drivers have embraced that change, with sales of battery powered and hybrid vehicles jumping 40% last year.

Korean researchers have succeeded in developing a key technology for all-solid-state secondary batteries, known as next-generation lithium-ion batteries due to their high safety. The work was published online as a cover study in Small at the end of last year.

Electronics and Telecommunications Research Institute (ETRI) developed a separation membrane based on a material that easily becomes fibrillized when subjected to mechanical shearing (force applied) through a mixing process with solid electrolyte powder without using a solvent. This solid electrolyte membrane is simple and fast to manufacture and is extremely thin and robust.

In general, in research on all-solid-state secondary batteries, the thickness is set to several hundred micrometers (µm) to 1 millimeter (mm) to increase the durability of the membrane when using a hard solid electrolyte in the manufacturing process. However, this has the disadvantage of being too thick compared to conventional polymer separation membranes, resulting in a very large loss of energy density.

Interconnected materials containing networks are ubiquitous in the world around us— rubber, car tires, human and engineered tissues, woven sheets and chain mail armor. Engineers often want these networks to be as strong as possible and to resist mechanical fracture and failure.

The key property that determines the strength of a network is its intrinsic fracture energy, the lowest energy required to propagate a crack through a unit area of the surface, with the bulk of the network falling apart. As examples, the intrinsic fracture energy of polymer networks is about 10 to 100 joules per square meter, 50–500 J/m2 for elastomers used in car tires, while spider silk has an intrinsic fracture energy of 150–200 J/m2.

Until now, there has been no way to calculate the intrinsic fracture energy (IFE) for a networked material, given the mechanical behavior and connectivity of its constituents.

Coal ash in the U.S. holds substantial rare earth elements, potentially reducing dependence on imports, with ongoing research and pilot projects working to make extraction economically viable.

Coal ash, the powdery residue left after burning coal for fuel, has accumulated across the United States for decades. New research from the University of Texas at Austin reveals that this vast supply contains enough rare earth elements to significantly strengthen the nation’s reserves without the need for additional mining.

“This really exemplifies the ‘trash to treasure’ mantra,” said co-lead author Bridget Scanlon, a research professor at UT’s Bureau of Economic Geology at the Jackson School of Geosciences. “We’re basically trying to close the cycle and use waste and recover resources in the waste, while at the same time reducing environmental impacts.”

Scientists in Japan have demonstrated a new method to create hydrogen fuel without emitting greenhouse gases. But key steps to improve its efficiency remain for it to be commercially viable.