Crystals are wonders of nature and science with important applications in electronics and optics. Scientists from Argonne have new insights into how gallium nitride crystals grow. Gallium nitride crystals are in wide use in light-emitting diodes (LEDs) and may form transistors for high-power switching electronics to make electric grids more energy efficient and smarter.
A metasurface hologram is an ultra-thin surface that is capable of arbitrarily shaping and projecting laser beams to extremely wide angles. However, due to the high coherence of laser light and inevitable defects in the metasurface, holographic images produced by meta-holograms suffer from deleterious artifacts that are extremely difficult to remove. A US-China team developed an efficient method to suppress holographic defects by fine-tuning the spatial coherence of laser illumination with a novel laser.
Tiny charged electrons and protons which can damage satellites and alter the ozone have revealed some of their mysteries to University of Otago scientists.
Large High Altitude Air Shower Observatory (LHAASO) located at Sichuan, China, detected dozen Ultra-high Energy gamma-ray sources, opening a new window into the γ-ray sky.
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LED lightbulbs offer considerable advantages over other types of lighting. Being more efficient, they require much less electricity to operate. They do not give off unwanted heat the way old-school incandescent bulbs do, and the best of them long outlast even fluorescent lightbulbs.
But LEDs are not problem-free. Questions linger over suspected links between health concerns such as fatigue, mood disorders, and insomnia from overexposure to the blue-tinted light produced by today s standard LED bulbs. Plus, higher prices can prompt lightbulb shoppers to weigh other options.
A University of Houston research team led by Jakoah Brgoch, associate professor of chemistry in the College of Natural Sciences and Mathematics and principal investigator in the Texas Center for Superconductivity, is developing an LED bulb that emits most of its energy from the safer violet segment of the visible light spectrum. Instead of just masking the blue light, they are developing a unique class