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Categories: Chemistry: General, Geoscience: Landslides

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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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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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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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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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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.

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Used lithium-ion batteries from cell phones, laptops and a growing number of electric vehicles are piling up, but options for recycling them remain limited mostly to burning or chemically dissolving shredded batteries. Researchers have improved on approaches that dissolve the battery in a liquid solution in order to reduce the amount of hazardous chemicals used in the process. This simple, efficient and environmentally-friendly solution overcomes the main obstacles presented by previous approaches.

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New technology often calls for new materials -- and with supercomputers and simulations, researchers don't have to wade through inefficient guesswork to invent them from scratch.

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Researchers could find no simple solution to limiting non-CO2 emissions from aircraft.

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Carbon capture is essential to reduce the impact of human carbon dioxide emissions on our climate. Researchers have developed a method to confirm whether carbon in concrete originates from the raw materials, or from carbon in the air which has been trapped when it reacts with the concrete to form the mineral calcium carbonate. By measuring the ratio of certain carbon isotopes in concrete that had been exposed to the air and concrete that hadn't, the team could successfully verify that direct air carbon capture had occurred.  This method could be useful for the industrial sector and countries looking to offset their carbon emissions.

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Research shows that variations in pyrite sulfur isotopes may not represent the global processes that have made them such popular targets of analysis and interpretation. A new microanalysis approach helps to separate out signals that reveal the relative influence of microbes and that of local climate.

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Researchers have devised a way to produce chemicals used in medicine and agriculture for a fraction of the usual cost. Using oxygen as a reagent and copper as a catalyst to break organic molecules' carbon-carbon bonds and convert them into amines, which are widely used in pharmaceuticals. Traditional metal catalysis uses expensive metals such as platinum, silver, gold and palladium, but the researchers used oxygen and copper -- an abundant base metal.

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Researchers create transistors combining silicon with biological silk, using common microprocessor manufacturing methods. The silk protein can be easily modified with other chemical and biological molecules to change its properties, leading to circuits that respond to biology and the environment.

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Researchers have developed a new method for the accurate determination of the water content of water-soluble compounds. This plays a significant role in various areas, including determining drug dosages.