Showing 20 articles starting at article 621
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Categories: Energy: Alternative Fuels, Offbeat: Space
Published Exciton fission: One photon in, two electrons out
(via sciencedaily.com) Original source Photovoltaics, the conversion of light to electricity, is a key technology for sustainable energy. Since the days of Max Planck and Albert Einstein, we know that light as well as electricity are quantized, meaning they come in tiny packets called photons and electrons. In a solar cell, the energy of a single photon is transferred to a single electron of the material, but no more than one. Only a few molecular materials like pentacene are an exception, where one photon is converted to two electrons instead. This excitation doubling, which is called exciton fission, could be extremely useful for high-efficiency photovoltaics, specifically to upgrade the dominant technology based on silicon. Researchers have now deciphered the first step of this process by recording an ultrafast movie of the photon-to-electricity conversion process, resolving a decades-old debate about the mechanism of the process.
Published Researchers develop an additive to efficiently improve the efficiency and stability of perovskite solar cells
(via sciencedaily.com) Original source Perovskite solar cells (PVSCs) are a promising alternative to traditional silicon-based solar cells because of their high power-conversion efficiency and low cost. However, one of the major challenges in their development has been achieving long-term stability. Recently, a research team made a breakthrough by developing an innovative multifunctional and non-volatile additive which can improve the efficiency and stability of perovskite solar cells by modulating perovskite film growth. This simple and effective strategy has great potential for facilitating the commercialization of PVSCs.
Published Neutron star's X-rays reveal 'photon metamorphosis'
(via sciencedaily.com) Original source A 'beautiful effect' predicted by quantum electrodynamics (QED) can explain the puzzling first observations of polarized X-rays emitted by a magnetar -- a neutron star featuring a powerful magnetic field, according to an astrophysicist.
Published Astronomers spot a star swallowing a planet
(via sciencedaily.com) Original source Scientists have observed a star swallowing a planet for the first time. Earth will meet a similar fate in 5 billion years.
Published Astronomers find distant gas clouds with leftovers of the first stars
(via sciencedaily.com) Original source Using ESO's Very Large Telescope (VLT), researchers have found for the first time the fingerprints left by the explosion of the first stars in the Universe. They detected three distant gas clouds whose chemical composition matches what we expect from the first stellar explosions. These findings bring us one step closer to understanding the nature of the first stars that formed after the Big Bang.
Published What would the Earth look like to an alien civilization located light years away?
(via sciencedaily.com) Original source What would the Earth look like to an alien civilization located light years away? A team of researchers has used crowd-sourced data to simulate radio leakage from mobile towers and predict what an alien civilization might detect from various nearby stars, including Barnard's star, six light years away from Earth.
Published A stormy, active sun may have kickstarted life on Earth
(via sciencedaily.com) Original source The first building blocks of life on Earth may have formed thanks to eruptions from our Sun, a new study finds. A series of chemical experiments show how solar particles, colliding with gases in Earth's early atmosphere, can form amino acids and carboxylic acids, the basic building blocks of proteins and organic life.
Published Webb finds water vapor, but from a rocky planet or its star?
(via sciencedaily.com) Original source Astronomers used NASA's James Webb Space Telescope to study a rocky exoplanet known as GJ 486 b. It is too close to its star to be within the habitable zone, with a surface temperature of about 800 degrees Fahrenheit (430 degrees Celsius). And yet, their observations show hints of water vapor.
Published Astronomers detect 'nearby' black hole devouring a star
(via sciencedaily.com) Original source Astronomers have discovered a new 'tidal disruption event,' in which the center of a galaxy lights up as its supermassive black hole rips apart a passing star. The outburst is the closest tidal disruption event observed to date, and one of the first to be identified at infrared wavelengths.
Published Most massive touching stars ever found will eventually collide as black holes
(via sciencedaily.com) Original source A new study looked at a known binary star (two stars orbiting around a mutual center of gravity), analyzing starlight obtained from a range of ground- and space-based telescopes. The researchers found that the stars, located in a neighboring dwarf galaxy called the Small Magellanic Cloud, are in partial contact and swapping material with each other, with one star currently 'feeding' off the other. They orbit each other every three days and are the most massive touching stars (known as contact binaries) yet observed.
Published Direct image of a black hole expelling a powerful jet
(via sciencedaily.com) Original source Astronomers have observed, in one image, the shadow of the black hole at the center of the galaxy Messier 87 (M87) and the powerful jet expelled from it. Thanks to this new image, astronomers can better understand how black holes can launch such energetic jets.
Published New chemistry can extract virgin-grade materials from wind turbine blades in one process
(via sciencedaily.com) Original source Researchers have developed a chemical process that can disassemble the epoxy composite of wind turbine blades and simultaneously extract intact glass fibers as well as one of the epoxy resin's original building blocks in a high quality. The recovered materials could potentially be used in the production of new blades.
Published Astronomers solve the 60-year mystery of quasars -- the most powerful objects in the Universe
(via sciencedaily.com) Original source Scientists have unlocked one of the biggest mysteries of quasars -- the brightest, most powerful objects in the Universe -- by discovering that they are ignited by galaxies colliding.
Published Medium-sized black holes eat stars like messy toddlers
(via sciencedaily.com) Original source In new 3D computer simulations, astrophysicists modeled black holes of varying masses and then hurled stars (about the size of our sun) past them to see what might happen. If they exist, intermediate-mass black holes likely devour wayward stars like a messy toddler -- taking a few bites and then flinging the remains across the galaxy.
Published Astrophysicists reveal the nature of dark matter through the study of crinkles in spacetime
(via sciencedaily.com) Original source Astrophysicists have provided the most direct evidence yet that Dark Matter does not constitute ultramassive particles as is commonly thought but instead comprises particles so light that they travel through space like waves. Their work resolves an outstanding problem in astrophysics first raised two decades ago: why do models that adopt ultramassive Dark Matter particles fail to correctly predict the observed positions and the brightness of multiple images of the same galaxy created by gravitational lensing?
Published Scientists detect seismic waves traveling through Martian core
(via sciencedaily.com) Original source New NASA InSight research reveals that Mars has a liquid core rich in sulfur and oxygen, leading to new clues about how terrestrial planets form, evolve and potentially sustain life.
Published Pioneering research sheds new light on the origins and composition of planet Mars
(via sciencedaily.com) Original source A new study has uncovered intriguing insights into the liquid core at the centre of Mars, furthering understanding of the planet's formation and evolution.
Published Outstanding performance of organic solar cell using tin oxide
(via sciencedaily.com) Original source Organic solar cells have a photoactive layer that is made from polymers and small molecules. The cells are very thin, can be flexible, and are easy to make. However, the efficiency of these cells is still much below that of conventional silicon-based ones. Applied physicists have now fabricated an organic solar cell with an efficiency of over 17 percent, which is in the top range for this type of material. It has the advantage of using an unusual device structure that is produced using a scalable technique.
Published It's not as difficult as you think to shout upwind
(via sciencedaily.com) Original source Why does it feel so difficult to shout upwind? The sensation is common enough to have found its way into an idiom about not being understood. Researchers wanted a scientific explanation for the phenomenon -- and there wasn't been one. They have now shown that our common sense understanding of this situation is wrong. It isn't harder to shout into the wind; it's just harder to hear yourself.
Published Transforming highways for high-speed travel and energy transport
(via sciencedaily.com) Original source Researchers developed a proof of concept for a superconducting highway that could transport vehicles and electricity, cooling the necessary superconductors with a pipeline of liquid hydrogen. Most magnetic levitation designs feature the superconductor inside the vehicle, which is suspended above a magnetic track. The authors decided to flip that arrangement upside down, putting the superconductor on the ground and giving each vehicle a magnet. The result is a system with multiple uses, placing it within the realm of affordability.