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Categories: Engineering: Graphene, Geoscience: Geomagnetic Storms

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While auroras occur at high latitude, the associated phenomena Steve and the picket fence occur farther south and at lower altitude. Their emissions also differ from aurora. A physics graduate student has proposed a physical mechanism behind these emissions, and a rocket launch to test the theory. She argues that an electric field in the upper atmosphere parallel to Earth's magnetic field could explain the green picket fence spectrum and perhaps Steve and the enhanced aurora.

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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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Graphene, that is extremely thin carbon, is considered a true miracle material. An international research team has now added another facet to its diverse properties with new experiments: Experts fired short terahertz pulses at micrometer-sized discs of graphene, which briefly turned these minuscule objects into surprisingly strong magnets. This discovery may prove useful for developing future magnetic switches and storage devices.

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An international multidisciplinary team consisting of solar physicists, geophysicists, and historians from nine countries analysed observations of an extreme solar-terrestrial storm reported in historical records from February 1872. Their findings confirm that a moderate sunspot group triggered one of the largest magnetic storms ever recorded, almost covering the entire night sky with colourful aurorae in both hemispheres. If such an extreme storm occurred today, it would severely disrupt modern technological infrastructure. Their study emphasizes the importance of looking at historical records in light of modern scientific knowledge.

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Researchers have discovered a new relationship between the Sun's magnetic field and its sunspot cycle, that can help predict when the peak in solar activity will occur. Their work indicates that the maximum intensity of solar cycle 25, the ongoing sunspot cycle, is imminent and likely to occur within a year.

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A research team has now directly measured the so-called Kondo effect, which governs the behavior of magnetic atoms surrounded by a sea of electrons: New observations with a scanning tunneling microscope reveal the effect in one-dimensional wires floating on graphene. 

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Sodium- and potassium-ion batteries are promising next-generation alternatives to the ubiquitous lithium-ion batteries (LIBs). However, their energy density still lags behind that of LIBs. To tackle this issue, researchers explored an innovative strategy to turn hard carbon into an excellent negative electrode material. Using inorganic zinc-based compounds as a template during synthesis, they prepared nanostructured hard carbon, which exhibits excellent performance in both alternative batteries.       

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Researchers have unveiled a remarkable new material with potential to impact the world of material science: amorphous silicon carbide (a-SiC). Beyond its exceptional strength, this material demonstrates mechanical properties crucial for vibration isolation on a microchip. Amorphous silicon carbide is therefore particularly suitable for making ultra-sensitive microchip sensors.

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Large geomagnetic storms disrupt radio signals and GPS. Now, researchers have identified the previous underestimated role of the ionosphere, a region of Earth's upper atmosphere that contains a high concentration of ions and free electrons, in determining how such storms develop. Understanding the interactions that cause large geomagnetic storms is important because they can disrupt radio signals and GPS. Their findings may help predict storms with the greatest potential consequences.

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It's viable to produce low-cost, lightweight solar panels that can generate energy in space, according to new research.

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Graphene is often referred to as a wonder material for its advantageous qualities. But its application in quantum computers, while promising, is stymied by the challenge of getting accurate measurements of quantum bit states with existing techniques. Now, researchers have developed design guidelines that enable radio-frequency reflectometry to achieve high-speed electrical readouts of graphene nanodevices. 

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When stacked in five layers in a rhombohedral pattern, graphene takes on a rare 'multiferroic' state, exhibiting both unconventional magnetism and an exotic electronic behavior known as ferro-valleytricity.

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Transition metal dichalcogenide (TMD) semiconductors are special materials that have long fascinated researchers with their unique properties. For one, they are flat, one-atom-thick two-dimensional (2D) materials similar to that of graphene. They are compounds that contain different combinations of the transition metal group (e.g., molybdenum, tungsten) and chalcogen elements (e.g., sulfur, selenium, tellurium).

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An international team of scientists have discovered a huge spike in radiocarbon levels 14,300 years ago by analyzing ancient tree-rings found in the French Alps. The radiocarbon spike was caused by a massive solar storm, the biggest ever identified.  A similar solar storm today would be catastrophic for modern technological society – potentially wiping out telecommunications and satellite systems, causing massive electricity grid blackouts, and costing us billions. The academics are warning of the importance of understanding such storms to protect our global communications and energy infrastructure for the future.

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Researchers have developed a 'quantum ruler' to measure and explore the strange properties of multilayered sheets of graphene, a form of carbon. The work may also lead to a new, miniaturized standard for electrical resistance that could calibrate electronic devices directly on the factory floor, eliminating the need to send them to an off-site standards laboratory.   

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A probable early driver of Alzheimer's disease is the accumulation of molecules called amyloid peptides. These cause cell death, and are commonly found in the brains of Alzheimer’s patients. Researchers have now shown that yeast cells that accumulate these misfolded amyloid peptides can recover after being treated with graphene oxide nanoflakes.

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The friction on a graphene surface can be dynamically tuned using external electric fields, according to researchers.

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A research team has successfully developed a new method that can prevent the crossover of large fuel molecules and suppress the degradation of electrodes in advanced fuel cell technology using methanol or formic acid. The successful sieving of the fuel molecules is achieved via selective proton transfers due to steric hindrance on holey graphene sheets that have chemical functionalization and act as proton-exchange membranes.

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Researchers created nanoribbons made of phosphorus and tiny amounts of arsenic, which they found were able to conduct electricity at temperatures above -140 degrees Celsius, while retaining the highly useful properties of the phosphorus-only ribbons.