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In a new study appearing this week in The Journal of Chemical Physics, researchers demonstrate a new method to calculate excitation energies. They used a new approach based on density functional methods, which use an atom-by-atom approach to calculate electronic interactions. By analyzing a benchmark set of small molecules and oligomers, their functional produced more accurate estimates of excitation energy compared to other commonly used density functionals, while requiring less computing power.

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Mobile phones and other wireless devices have become central features of life around the globe. It is crucial to the design and deployment of these devices that they have accurate and traceable measurements for electric fields and radiated power. Until recently, however, it was not possible to build self-calibrating probes that could generate independent and absolute measurements of these electric field values. To address this problem, researchers have developed a new method to measure electric fields and a new probe to carry out such measurements. They share their work this week in the Journal of Applied Physics.

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Waves deep within the ocean play an important role in establishing ocean circulation, arising when tidal currents oscillate over an uneven ocean bottom. The internal waves generated by this process stir and mix the ocean, bringing cold, deep water to the surface to be warmed by the sun. This week in the Physics of Fluids, investigators how to tell which way internal waves will go. The proposed theory unifies several previously understood explanations of wave propagation.

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Capillary discharge plasma jets are created by a large current that passes through a low-density gas in what is called a capillary chamber. The gas ionizes and turns into plasma, a mixture of electrons and positively charged ions. When plasma expands in the capillary chamber due to arc energy heating, plasma ejects from the capillary nozzle forming the plasma jet. This week in Review of Scientific Instruments, a new study examines how the dimensions of the capillary producing the plasma affect the jet’s length.

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An international team of scientists recently discovered the role that hot electrons may play in the waves and fluctuations detected by satellites. The research team reports its findings this week in Physics of Plasmas. Their results are based on data collected by the Van Allen Probes, twin robotic spacecraft launched by NASA in 2012 to help scientists better understand these belt regions.

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If you can’t move electrons around to study how factors like symmetry impact the larger-scale magnetic effects, what can you do instead? It turns out that assemblies of metallic nanoparticles, which can be carefully arranged at multiple length scales, behave like bulk magnets and display intriguing, shape-dependent behavior. The effects, reported this week in the Journal of Applied Physics, could help improve high-density information storage and spintronics technologies.

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Chemical reactions necessarily involve molecules coming together, and the way they interact can depend on how they are aligned relative to each other. By knowing and controlling the alignment of molecules, a great deal can be learned about how chemical reactions occur. This week in The Journal of Chemical Physics, scientists from Denmark and Austria report a new technique for aligning molecules using lasers and very cold droplets of helium.

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The classic method for studying how electrons interact with matter is by analyzing their scattering through thin layers of a known substance. This happens by directing a stream of electrons at the layer and analyzing the subsequent deviations in the electrons’ trajectories. But researchers in Switzerland have devised a way to examine the movement of low-energy electrons that can adversely impact electronic systems and biological tissue. They discuss this in this week’s The Journal of Chemical Physics.

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To get maximum propulsion, should a boat’s team of rowers set their strokes to the same rhythm? Or should the rowers stagger the dropping and pulling of the oars through the water? This month’s Physics Today features a special article by fluid mechanic researchers at the Paris École Polytechnique, who provide data and fundamental physics approaches for coaches, sportspersons and scientists to keep in mind the next time they observe or get into a crew boat.

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Researchers have developed a capacitor with a metal-insulator-semiconductor diode structure that is tunable by illumination. The capacitor, which features embedded metal nanoparticles, is similar to a metal-insulator-metal diode, except the capacitance of the new device depends on illumination and exhibits a strong frequency dispersion, allowing for a high degree of tunability. This capacitor may enhance wireless capability for information processing, sensing and telecommunications. The researchers report their findings in this week’s Journal of Applied Physics.

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Researchers have developed a detailed computational model of the soybean plasma membrane that provides new structural insight at the molecular level, which may have applications for studying membrane proteins and may be useful for engineering plants to produce biochemicals, biofuels, drugs and other compounds, and in understanding how plants sense and respond to stressful conditions. The group report their findings this week in The Journal of Chemical Physics.

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Despite the importance of predicting solubility, it is not an easy matter. One approach, using “brute force” simulations, requires long computing times. Other techniques, while faster, fail to predict accurate solubility values. This week in The Journal of Chemical Physics, researchers report a new type of software that enables convenient solubility estimations of essentially any molecular substance over wide temperature and pressure ranges.

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The American Institute of Physics (AIP) and AIP Publishing are pleased to announce the launch of a new online magazine, Bioengineering Today. Bioengineering Today offers news and information about the intersection of biology, chemistry and physics with medicine. The articles cover everything from biomedical discoveries, research, new devices, new imaging technologies, engineering and applications of physics to bioengineering as well as disease detection, prevention and treatment.

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A research group in Singapore has used computer simulations to further probe the behaviors of skyrmions, gaining insight that can help scientists and engineers better study the quasi-particles in experiments. The new results, published this week in AIP Advances, could also lead to skyrmion-based devices such as microwave nano-oscillators, used in a range of applications including wireless communication, imaging systems, radar and GPS.

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Neutrons are inherently unstable and don’t last long outside an atomic nucleus, and because they decay on a time scale similar to the period for Big Bang Nucleosynthesis, accurate simulations of the BBN era require thorough knowledge of the neutron lifetime, but this value is still not precisely known. This week in Review of Scientific Instruments, scientists at Los Alamos National Lab report an exciting new method to measure it.

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A team of researchers has now developed a magnetoelectric random access memory (MELRAM) cell that has the potential to increase power efficiency, and thereby decrease heat waste, by orders of magnitude for read operations at room temperature. The research could aid production of devices such as instant-on laptops, close-to-zero-consumption flash drives, and data storage centers that require much less air conditioning. The research team reported their findings this week in Applied Physics Letters.

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Materials exposed to neutron radiation tend to experience significant damage. At the nanoscale, these incident neutrons collide with a material’s atoms, which then collide with each other. The resulting disordered atomic network resembles those seen in some glassy materials, which has led many in the field to use them in nuclear research. But the similarities between the materials may not be as useful as previously thought, according to this week’s The Journal of Chemical Physics.

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The most established plasma propulsion concepts are gridded-ion thrusters that accelerate and emit a larger number of positively charged particles than those that are negatively charged. To enable the spacecraft to remain charge-neutral, a “neutralizer” is used to inject electrons to exactly balance the positive ion charge in the exhaust beam. However, the neutralizer requires additional power from the spacecraft and increases the size and weight of the propulsion system. Researchers are investigating how the radio-frequency self-bias effect can be used to remove the neutralizer altogether, and they report their work in this week’s Physics of Plasmas.

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A new simulation based on the von-Kármán-Sodium (VKS) dynamo experiment takes a closer look at how the liquid vortex created by the device generates a magnetic field. Researchers investigated the effects of fluid resistivity and turbulence on the collimation of the magnetic field, where the vortex becomes a focused stream. They report their findings this week in the journal Physics of Fluids.

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It may be surprising to learn that much remains unknown about radiation’s effects on materials. To find answers, Massachusetts Institute of Technology researchers are developing techniques to explore the microstructural evolution and degradation of materials exposed to radiation. They report a dynamic option, this week in Applied Physics Letters, to continuously monitor the properties of materials being exposed to radiation during the exposure. This provides real-time information about a material’s microstructural evolution.

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New research into osmosis-driven behavior now provides a more granular theoretical understanding of the deterministic mechanisms, appearing as a pair of publications this week in The Journal of Chemical Physics. The first paper deconstructs the molecular mechanics of osmosis with high concentrations, and generalizes the findings to predict behavior for arbitrary concentrations. The second piece of the study then simulates via molecular modeling two key forms of osmotic flow in a broadly utilizable way.

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Most transistors are silicon-based and silicon technology has driven the computer revolution. In some applications, however, silicon has significant limitations. Silicon devices are prone to faltering and failing in difficult environments. Addressing these challenges, Jiangwei Liu, from Japan’s National Institute for Materials Sciences, and his colleagues describe new work developing diamond-based transistors this week in the journal Applied Physics Letters, from AIP Publishing.

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A research team in China have developed a new CESL method that introduces tensile stress into both the channel and the drift region, improving overall performance by offering low drift resistance, high cut-off frequency and desirable breakdown characteristics. Their work is described in an article appearing this week in the journal AIP Advances, from AIP Publishing.

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Triboelectric nanogenerators (TENGs) are small devices that convert movement into electricity, and might just be what bring us into an era of energy-harvesting clothes and implants. But could TENGs, even theoretically, give us wearable electronics powered solely by the wearer’s day-to-day body motion? The short answer is yes. New research published this week in APL Materials demonstrates the ability of mechanical energy produced by typical body motions to power a watch or smartphone.

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More than a decade ago, researchers discovered that when they added boron to the carbon structure of diamond, the combination was superconductive. Since then, growing interest has been generated in understanding these superconducting properties. With this interest, a research group in India focused on a Fano resonance in a heavily boron-doped diamond (BDD) that involves the vibrational mode of diamond. The researchers report their findings this week in Applied Physics Letters.

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Researchers are exploring how molecular simulations with the latest optimization strategies can create a more systematic way of discovering new materials that exhibit specific, desired properties. More specifically, they did so by recasting the design goal to the microscopic, asking which interactions between constituent particles can cause them to spontaneously “self-assemble” into a bulk material with a particular property. To find the answer, reported this week in The Journal of Chemical Physics, they decided to zero in on how composite particles spatially organize themselves.

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Whether you are a researcher who inveterately reads journals or someone who occasionally glides through the realms of science writing, your looking through scientific publications might well feel like a bumpy flight. Some articles require subscriptions, while others are “open access.” This month’s Physics Today should help you understand the turbulence. Journalist David Kramer explains the changes and markets of science publishing in “Steady, strong growth is expected for open-access journals.”

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Current drilling and fracturing methods can't extract oil and natural gas very well, recovering an estimated 5 percent of oil and 20 percent of gas from shale. That's partly due to a poor understanding of how fluids flow through these small pores, which measure only nanometers across. But new computer simulations, described this week in the Physics of Fluids, can better probe the underlying physics, potentially leading to more efficient extraction of oil and gas.

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When spacecraft and satellites travel through space they encounter tiny, fast moving particles of space dust and debris. If the particle travels fast enough, its impact appears to create electromagnetic radiation (in the form of radio waves) that can damage or even disable the craft’s electronic systems. A new study published this week in the journal Physics of Plasmas, from AIP Publishing, uses computer simulations to show that the cloud of plasma generated from the particle’s impact is responsible for creating the damaging electromagnetic pulse. They show that as the plasma expands into the surrounding vacuum, the ions and electrons travel at different speeds and separate in a way that creates radio frequency emissions.

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Little is known about which specific areas of the brain contribute to a patient’s epileptic network or the roles these different areas play. As a group of researchers in Germany now reports this week in Chaos, one way to get closer to the complex wiring of the human brain is by merging concepts from a timed-based synchronization theory and space-based network theory to construct functional brain networks.

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In "Minority Report,” the protagonist uses gloves that give him the power of virtual manipulation. The light seems to allow him to control the screen as if it were a touchscreen, but he's touching nothing but air. That technology is still science fiction, but a new study may bring it closer to reality. Researchers report in Applied Physics Letters that they have discovered the photodielectric effect, which could lead to laser-controlled touch displays.

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Researchers at the University of California, Riverside, inspired by efforts to promote green energy, are exploring the factors driving commercial customers in Southern California, both large and small, to purchase and install solar photovoltaic (PV) systems. As the group reports this week in the Journal of Renewable and Sustainable Energy, they built a model for commercial solar PV adoption to quantify the impact of government incentives and solar PV costs.

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Inspired by 3-D printing, researchers explored development of one mechanical property called effective static compressibility. As they now report in Applied Physics Letters, by using a single cartridge it’s possible to print a metamaterial which expands in size under hydrostatic pressure, even though it’s made up of material which behaves normally under hydrostatic pressure -- that is, it shrinks. In principle, there is no limit to the negative value this material’s effective compressibility can take.

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Researchers in South Korea have quantitatively deconstructed what they describe as the “ingenious mobility strategies” of seeds that self-burrow rotationally into soil. Seeds maneuvered to dig into soil using a coiled appendage, known as an awn, that responds to humidity. The team investigated this awn’s burrowing and discovered how the nubile sprouts seem to mimic a drill to bury themselves. Their findings, published in Physics of Fluids, could have dramatic implications for improving agricultural robotics.

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Approximately 10-20 percent of white dwarfs exhibit strong magnetic fields, some of which can reach up to 100,000 tesla. In comparison, on Earth, the strongest magnetic fields that can be generated using nondestructive magnets are about 100 tesla. Therefore, studying the chemistry in such extreme conditions is only possible using theory and until now has not provided much insight to the spectra accompanying white dwarfs. Researchers in Germany describe their work modeling these systems this week in The Journal of Chemical Physics.

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Researchers at Northwestern University have created a new method to extract the static and dynamic structure of complex chemical systems. In this context, “structure” doesn’t just mean the 3-D arrangement of atoms that make up a molecule, but rather time-dependent quantum-mechanical degrees of freedom that dictate the optical, chemical and physical properties of the system. They discuss their work in this week’s The Journal of Chemical Physics.

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The study of jet disintegration in particular focuses on fuel breakup and mixing within the combustion chamber of propulsion devices. A team of researchers at the University of Florida applied spectroscopic diagnostics techniques to learn more about the fundamentals of sub- and supercritical jet disintegration, and reports their new findings this week in the journal Physics of Fluids.

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Particle physicist Don Lincoln is the winner of the 2017 Andrew Gemant Award, an annual prize recognizing significant contributions to the cultural, artistic or humanistic dimension of physics, the American Institute of Physics (AIP) announced today.

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Genome mapping complements DNA sequencing, offering insight into huge, intact molecules between 150,000 and 1 million base pairs in length. Obtaining measurements of such large segments is not without its challenges, but new research into the physics of nanochannel mapping published this week in the journal Biomicrofluidics, may help overcome a (literal) knot in the process and advance genome mapping technology.

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Indistinguishable photons are critical for quantum information processing, and a group of researchers in Japan is tapping nitrogen impurity centers found within gallium arsenide to generate them -- making a significant contribution toward realizing a large number of indistinguishable single-photon sources.

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A group of researchers at Zhejiang University recently discovered that a new bubbling mechanism may exist within the realm of physics. They made this surprising finding while studying the bubbling phenomena in submerged gas-liquid jets in microchannels. The phenomenon occurred in an immersion lithography machine they had developed, causing vibrations that were damaging exposure quality. They report their work in this week in the journal Physics of Fluids.

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Physics Today magazine features “From Sound to Meaning” this month, a special article highlighting physics’ role in understanding language

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Computer electronics are shrinking to small enough sizes that the electrical currents underlying their functions can no longer be used for logic computations in the ways of their larger-scale ancestors. A traditional semiconductor-based logic gate called a majority gate, for instance, outputs current to match either the “0” or “1” state that comprise at least two of its three input currents (or equivalently, three voltages). But how do you build a logic gate for devices too small for classical physics?

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The performance of electronic devices is constrained by their inability to evenly dissipate the waste heat they produce. Since the waste heat isn’t uniformly distributed, hotspots are all too prevalent in electronics. While a few options for hotspot cooling exist, they don't work well for mobile hotspots, which move according to ever-changing computing tasks or power-amplification demands. In this week’s Applied Physics Letters, researchers report a “jumping droplet” technique designed specifically to address mobile hotspots.

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Viscous fingering occurs in porous media where fluids of differing viscosity converge in finger-shaped patterns as a result of growing disturbances at the interface. Such instabilities are encountered in a wide variety of fields. Understanding different aspects of this phenomenon, and the variables that can control things like instabilities and velocity distribution dynamics, can potentially offer options to control and utilize these effects more effectively. Researchers report their findings in this week’s Physics of Fluids.

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While memory devices are becoming progressively more flexible, their ease of fabrication and integration in low performance applications have been generally been treated as being of secondary importance. But now, thanks to the work of researchers at Munich University of Applied Sciences and INRS-EMT, this is about to change. In this week’s Applied Physics Letters, they presents a proof of concept, using resistive memory that now paves the way for mass-producing printable electronics.

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Researchers from Canada, the U.K. and Germany have developed a new experimental technique to take 3-D images of molecules in action. This tool can help scientists better understand the quantum mechanics underlying bigger and more complex molecules. They describe their work in this week’s The Journal of Chemical Physics.

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While bigger nanowires can improve light confinement and performance, it increases both energy consumption and device footprint -- both of which are considered “fatal” when it comes to integration. Addressing this problem, researchers came up with an approach that involves combining a sub-wavelength nanowire with a photonic crystal platform, which they report this week in the journal APL Photonics.

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High-intensity focused ultrasound (HIFU) is a breakthrough therapeutic technique used to treat tumors. The principle of this noninvasive, targeted treatment is much like that of focusing sunlight through a lens, using an ultrasonic transducer like a convex lens to concentrate ultrasound into a small focal region. In this week’s Journal of Applied Physics, researchers have now designed a transducer for potential application in HIFU that can generate a steady, standing-wave field with a subwavelength-scale focal region and extremely high ultrasound intensity.

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The American Institute of Physics (AIP) and the Acoustical Society of America (ASA) are both accepting submissions for their respective 2017 science writing awards. The deadline for entries for each award is March 31, 2017.