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Categories: Chemistry: Thermodynamics, Physics: Acoustics and Ultrasound

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The world is filled with a myriad of sounds and vibrations -- the gentle tones of a piano drifting down the hall, the relaxing purr of a cat laying on your chest, the annoying hum of the office lights. Imagine being able to selectively tune out noises of a certain frequency. Researchers have now synthesized polymer networks with two distinct architectures and crosslink points capable of dynamically exchanging polymer strands to understand how the network connectivity and bond exchange mechanisms govern the overall damping behavior of the network. The incorporation of dynamic bonds into the polymer network demonstrates excellent damping of sound and vibrations at well-defined frequencies.

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If you have a deep-seated, nagging worry over dropping your phone in molten lava, you're in luck. Materials scientists have developed a method for rapidly discovering a new class of materials with heat and electronic tolerances so rugged that they that could enable devices to function at several thousands of degrees Fahrenheit.

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A research team has fabricated a gallium nitride (GaN) transistor using diamond, which of all natural materials has the highest thermal conductivity on earth, as a substrate, and they succeeded in increasing heat dissipation by more than two times compared with conventional transistors. The transistor is expected to be useful not only in the fields of 5G communication base stations, weather radar, and satellite communications, but also in microwave heating and plasma processing.

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Researchers have identified a welding technique that can be used to join composite metal foam (CMF) components together without impairing the properties that make CMF desirable. CMFs hold promise for a wide array of applications because the pockets of air they contain make them light, strong and effective at insulating against high temperatures.

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In a new study, researchers present an adaptive tile, which when deployed in arrays on roofs, can lower heating bills in winter and cooling bills in summer, without the need for electronics.

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Scientists have solved a decades-long puzzle and unveiled a near unbreakable substance that could rival diamond, as the hardest material on earth, a study says. Researchers found that when carbon and nitrogen precursors were subjected to extreme heat and pressure, the resulting materials -- known as carbon nitrides -- were tougher than cubic boron nitride, the second hardest material after diamond.

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A fabrication process can produce self-heating microfluidic devices in one step using a multimaterial 3D printer. These devices, which can be made rapidly and cheaply in large numbers, could help clinicians in remote parts of the world detect diseases without expensive lab equipment.

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Researchers investigated the thermal energy changes across nanopores that allow the selective flow of ions. Switching off the flow of ions in one direction led to a cooling effect. The findings have applications in nanofluidic devices and provide insight into the factors governing ion channels in cells. The nanopore material could be tailored to tune the cooling and arrays could be produced to scale up the effect.

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On the highway of heat transfer, thermal energy is moved by way of quantum particles called phonons. But at the nanoscale of today's most cutting-edge semiconductors, those phonons don't remove enough heat. That's why researchers are focused on opening a new nanoscale lane on the heat transfer highway by using hybrid quasiparticles called 'polaritons.'

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Engineers have developed a bio-compatible ink that solidifies into different 3D shapes and structures by absorbing ultrasound waves. Because the material responds to sound waves rather than light, the ink can be used in deep tissues for biomedical purposes ranging from bone healing to heart valve repair.

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The topic of water and the way it can move producing water droplets that leap -- propelled by surface tension -- and frost that jumps -- by way of electrostatics -- is a central focus of a group of scientists. Having incorporated the two phases of liquid and solid in the first two volumes of their research, their third volume investigates a third phase, with boiling water.

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The sound a disc makes while soaring through the air is full of information about how fast the disc is flying and how quickly it spins. This inspired Kyle S. Dalton of Penn State University to combine disc golf and acoustics into an interactive acoustic signal processing lesson. He set three microphones in a line and connected them to equipment that converts each microphone's signal to a data point. Then he threw a disc with a small whistle mounted on top and recorded the flying disc's acoustical signal. The resulting dataset can be used to learn basic processing tools and practice data visualization.

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An inspection design method and procedure by which mobile robots can inspect large pipe structures has been demonstrated with the successful inspection of multiple defects on a three-meter long steel pipe using guided acoustic wave sensors.

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Salt batteries can store summer heat to be used in winter, but which salt works best for the purpose?

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Donor doping into a mother material with disordered intrinsic oxygen vacancies, instead of the widely used strategy of acceptor doping into a material without oxygen vacancies, can greatly enhance the conductivity and stability of perovskite-type proton conductors at intermediate and low temperatures of 250--400 °C.

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An engineering research team is pioneering a new method, based on percussion, to detect pipeline elbow erosion to prevent economic losses, environmental pollution and other safety issues.  

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A novel measurement technique has been developed to visualize the fluid flow and distribution within two droplets levitated and coalesced in space using fluorescence-emitting particles. This technique enabled the estimation of fluid motion within each droplet, thereby revealing the internal flow caused by surface vibration when the droplet merging promotes fluid mixing.

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As power generation from sources like solar and wind increases, along with the introduction of devices such as heat pumps and batteries, a new optimization tool will help the UK plan for a greener electricity network.   The researchers developed an algorithm to model how these smaller networks distributed electricity -- factoring in how local grids could become unbalanced by adding too many heat pumps in a single area or generating more electricity than the grid could accept.  

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A team of researchers looked back at a model that predicted nuclear power would expand dramatically in order to assess the efficacy of energy policies implemented today.

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A new technique offers a safe, reliable, and high-throughput way to dynamically characterize microscale metamaterials. The method could speed up the development of acoustic lenses, impact-resistant films, and other futuristic materials.