Category Technology/Electronics

New Phenomenon of Abrupt Excitation of Fluctuations in high-temperature plasma

Figure 2: This shows the restoring force against the growth of fluctuations. When the amplitude is lower than the threshold value, the amplitude approaches zero and is stable (black). Separating from the center, when the amplitude exceeds the threshold value, the amplitude abruptly grows red. Credit: National Institutes of Natural Sciences

Figure 2: This shows the restoring force against the growth of fluctuations. When the amplitude is lower than the threshold value, the amplitude approaches zero and is stable (black). Separating from the center, when the amplitude exceeds the threshold value, the amplitude abruptly grows red. Credit: National Institutes of Natural Sciences

In the Large Helical Device (LHD) at the National Institute for Fusion Science in Japan, researchers have developed the high-energy heavy ion beam probe, in order to perform potential measurement inside plasma that was generated in the LHD and have clarified the mechanism of this new phenomenon.

Seeking to achieve nuclear fusion, research on plasma of >100,000,000 C is being conducted around the world...

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2-stage Power Management System Boosts Energy-Harvesting Efficiency of Triboelectric Generators

With this triboelectric nanogenerator and two-stage power management and storage system, finger tapping motion generates enough power to operate this scientific calculator. Credit: Credit: Zhong Lin Wang Laboratory

With this triboelectric nanogenerator and two-stage power management and storage system, finger tapping motion generates enough power to operate this scientific calculator. Credit: Credit: Zhong Lin Wang Laboratory

These generators harvest energy from irregular human motion such as walking, running or finger tapping. The system uses a small capacitor to capture alternating current generated by the biomechanical activity. When the first capacitor fills, a power management circuit then feeds the electricity into a battery or larger capacitor. This 2nd storage device supplies DC current at voltages appropriate for powering wearable and mobile devices such as watches, heart monitors, calculators, thermometers – and even wireless remote entry devices for vehicles.

By matching the impedance of t...

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Recycling Light

A nanophotonic incandescent light bulb demonstrates the ability to tailor light radiated by a hot object. Credit: Ognjen Ilic

A nanophotonic incandescent light bulb demonstrates the ability to tailor light radiated by a hot object. Credit: Ognjen Ilic

How photonics can reshape the spectrum of light, and rehabilitate Edison’s light bulb along the way. The incandescent bulb is an example of a high temperature thermal emitter. It is very useful, but only a small fraction of the emitted light (and therefore energy) is used: most of the light is emitted in the infrared and in this context wasted. Now, MIT researchers describes another way to recycle light emitted at unwanted infrared wavelengths while optimizing the emission at useful visible wavelengths.

While as a proof-of-concept the research group built a more energy-efficient incandescent light bulb, the same approach could also be used to improve the performance...

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New Lithium-ion Battery Shuts down at High Temperatures, Restarts when it Cools

Stanford researchers are using spiky nanoparticles of graphene-coated nickel to create a lithium-ion battery that shuts down when it's too hot, then quickly restarts when it cools (1µ =1 micrometer). Credit: Zheng Chen, Stanford University

Stanford researchers are using spiky nanoparticles of graphene-coated nickel to create a lithium-ion battery that shuts down when it’s too hot, then quickly restarts when it cools (1µ =1 micrometer). Credit: Zheng Chen, Stanford University

The new technology could prevent the kind of fires that have prompted recalls and bans on a wide range of battery-powered devices, from recliners and computers to navigation systems and hoverboards. “People have tried different strategies to solve the problem of accidental fires in lithium-ion batteries,” said Prof. Zhenan Bao, chemical engineering, Stanford. It “can be shut down and revived over repeated heating and cooling cycles without compromising performance.”

A typical Li-ion battery consists of 2 electrodes and a liquid or gel electrolyte that c...

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