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Categories: Chemistry: General, Space: Cosmology

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Experts have developed a way of using polyethylene waste (PE) as a feedstock and converted it into valuable chemicals, via light-driven photocatalysis. PE is the most widely used plastic in the world including for daily food packaging, shopping bags and reagent bottles, and the researchers say that while recycling of PE is still in early development, it could be an untapped resource for re-use.

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In hopes of producing concrete structures that can repair their cracks, researchers are putting a new twist on an old trick for improving the durability of concrete. Fiber reinforcement has been around since the first masons were mixing horsehair into their mud. But this research team is taking this method to the next level by turning reinforcing fibers into a living tissue system that rushes concrete-healing bacteria to the site of cracks to repair the damage.

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After more than a decade of developing fluorescent probes, a research team has now released the culmination of their years of work: A comprehensive collection of rhodamine-based dyes, the novel chemistry they developed to synthesize them and insights that provide a roadmap for designing future probes.

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How heavy can an element be? An international team of researchers has found that ancient stars were capable of producing elements with atomic masses greater than 260, heavier than any element on the periodic table found naturally on Earth. The finding deepens our understanding of element formation in stars.

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Scientists chipping away at one of the great challenges of metal-catalyzed C--H functionalization with a new method that uses a cobalt catalyst to differentiate between bonds in fluoroarenes, functionalizing them based on their intrinsic electronic properties. And their method is fast -- comparable in speed to those that rely on iridium.

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Galactic winds enable the exchange of matter between galaxies and their surroundings. In this way, they limit the growth of galaxies, that is, their star formation rate. Although this had already been observed in the local universe, an international research team has just revealed the existence of the phenomenon in galaxies which are more than 7 billion years old and actively forming stars, the category to which most galaxies belong. The team's findings thus show this is a universal process.

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Chemists have now come up with a way to make molecules known as acenes more stable, allowing them to synthesize acenes of varying lengths. Using their new approach, they were able to build molecules that emit red, orange, yellow, green, or blue light, which could make acenes easier to deploy in a variety of applications.

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Through analysis of high-resolution data from a ten-meter telescope in Hawaii, researchers have succeeded in generating new knowledge about three stars at the very heart of the Milky Way. The stars proved to be unusually young with a puzzling chemical composition that surprised the researchers.

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Amid the rubble of large-sale earthquake, war or other disaster -- and as ageing buildings and infrastructure are replaced -- mountains of concrete are often taken to landfill or pounded into rubble for roads. For a more sustainable approach, experts are developing a 'value add' for old broken concrete to 'upcycling' coarse aggregate to produce a strong, durable and workable concrete using a small amount of a secret ingredient -- graphene.

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Satellite and spacecraft operators may finally be able to detect small pieces of debris orbiting Earth using a new approach. Colliding pieces of space debris emit electric signals that could help track small debris littering Earth's orbit, potentially saving satellites and spacecraft.

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Scientists have made a significant stride toward understanding a viable process for direct air capture, or DAC, of carbon dioxide from the atmosphere. This DAC process is in early development with the aim of achieving negative emissions, where the amount of carbon dioxide removed from the envelope of gases surrounding Earth exceeds the amount emitted.

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Astronomers studying images from the James Webb Space Telescope have identified an object as a 'dusty star-forming galaxy' from nearly 1 billion years after the Big Bang. They have also discovered more than a dozen additional candidates, suggesting these galaxies might be three to 10 times as common as expected. If that conclusion is confirmed, it suggests the early universe was much dustier than previously thought.

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Friction is hard to predict and control, especially since surfaces that come in contact are rarely perfectly flat. New experiments demonstrate that the amount of friction between two silicon surfaces, even at large scales, is determined by the forming and rupturing of microscopic chemical bonds between them. This makes it possible to control the amount of friction using surface chemistry techniques.

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The universe is expanding. How fast it does so is described by the so-called Hubble-Lemaitre constant. But there is a dispute about how big this constant actually is: Different measurement methods provide contradictory values. This so-called 'Hubble tension' poses a puzzle for cosmologists. Researchers are now proposing a new solution: Using an alternative theory of gravity, the discrepancy in the measured values can be easily explained -- the Hubble tension disappears.

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A collaborative research team has discovered a new process for making anhydrides that promises improvements in costs and sustainability.

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Civil and environmental engineers have determined the factors that may help identify the schools and daycare centers at greatest risk for elevated levels of lead in drinking water. The most telling characteristic for schools in Massachusetts is building age, with facilities built in the 1960s and 1970s -- nearly a third of the facilities tested -- at the greatest risk for having dangerously high water lead levels. 

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Scientists provide new evidence to motivate rapid fossil fuel phaseout. The science team determined exposure to ambient air pollution and its health impacts using an updated atmospheric composition model, a newly developed relative risk model and recent satellite-based fine particle data. They estimated all-cause and disease-specific mortality and attributed them to emission categories. They show that phasing out fossil fuels is a remarkably effective health-improving and life-saving intervention. About 5 million excess deaths per year globally could potentially be avoided.  

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Found in fishing nets, carpet, clothing, Nylon-6 is a major contributor to plastic pollution, including ocean pollution. Now, chemists have developed a new catalyst that quickly, cleanly and completely breaks down Nylon-6 in a matter of minutes -- without generating harmful byproducts. Even better: The process does not require toxic solvents, expensive materials or extreme conditions, making it practical for everyday applications. In experiments, the new process recovered 99% of the polymer's building blocks, which can then be upcycled into higher-value products.

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World War II concluded decades ago, but live mines lurking on the ocean floor still pose threats, potentially spewing unexpected geysers or releasing contaminants into the water. Experts conduct controlled explosions to clear underwater munitions, but concerns have arisen over the environmental impacts from these blasts. New results show that the contamination produced by detonation depends on the blast type, with weaker explosions leaving behind more potentially toxic residues.

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Researchers have developed an AI model that can predict where a drug molecule can be chemically altered.