American Physical Society Focus August 2, 2019 It is long assumed that light hitting a metal surface at an angle pushes on the free electrons, moving them forward. A team of researchers in the US (NIST, University of Maryland, Brown University) aimed an infrared laser toward the metal surface at a glancing angle and placed an electrode at the far end of the metal sample to detect any voltage created if the light drove the electrons along the metal, which would create an excess of negative charge at the far end. As they varied the angle, the team measured a […]
Machine learning helps predict if storms will cause power outages
Science Daily August 2, 2019 Researchers in Finland collected data about the amount of power disruptions to their network from companies who have power grids through storm-prone central Finland. They sorted the storms into 4 classes, class 0 did not knock out electricity, class 1 storm cut-off up to 10% of transformers, class 2 up to 50%, and class 3 storm cut power to over 50% of the transformers. By grouping 16 different features of each storm, they were able to train the computer to recognize when storms will be damaging. The algorithm was very good at predicting which storms […]
Physicists make graphene discovery that could help develop superconductors
EurekAlert August 1, 2019 An international team of researchers (USA – Rutgers University, Japan) studied twisted bilayer graphene, created by superimposing two layers of graphene and slightly misaligning them. This creates a “twist angle” that results in a moiré pattern which changes rapidly when the twist angle changes and have a dramatic effect on the electronic properties of the material. This is because the moiré pattern slows down the electrons that conduct electricity in graphene and zip past each other at great speeds. At a twist angle of about 1.1 degrees – the so-called magic angle – the electrons come […]
Project BioShield: Building a Better Medical Countermeasure Pipeline
Global Biodefense August 5, 2019 When Project BioShield was initially signed into law 15 years ago, the nation had few medical countermeasures to rely on in national emergencies. BARDA has since supported 27 projects using Project BioShield authorities and funding, adding 15 products to the Strategic National Stockpile. Working with industry partners, 10 of those products have achieved FDA approval and the others are available under FDA Emergency Use Authorization guidelines. Companies interested in partnering with BARDA on medical countermeasures to combat chemical, biological, radiological, or nuclear (CBRN) threats, pandemic influenza or other emerging infectious diseases, can get insights and […]
Quantum light sources pave the way for optical circuits
Science Daily August 1, 2019 The ability to tailor quantum emitters via site-selective defect engineering is essential for realizing scalable architectures. However, a major difficulty is that defects need to be controllably positioned within the material. An international team of researchers (Germany, USA – SUNY Buffalo, Japan) has overcome this challenge by controllably irradiating monolayer MoS2 using a sub-nm focused helium ion beam to deterministically create defects. Subsequent encapsulation of the ion exposed MoS2 flake with high-quality hBN reveals spectrally narrow emission lines that produce photons in the visible spectral range. The new method allows for a multitude of applications in […]
Scientists develop filter to suppress radio interference
Phys.org August 6, 2019 To reduce the level of interference, devices that carry out the frequency filtering of radio noise are used. Researchers in Russia have designed a miniature stripline resonator on a substrate with a double-sided pattern of strip conductors. The design demonstrates the unique steepness of the slopes of the pass band and the ultra-wide high-frequency stop band, which reaches 100 dB in frequency (attenuation power decay is 10 orders of magnitude) up to a frequency five times the center frequency of the pass band. As several oscillation modes are used in the cavity as working, they managed […]
Technique uses magnets, light to control and reconfigure soft robots
Science Daily August 2, 2019 A team of researchers in the US (North Carolina State University, Elon University) has developed a technique that allows them to remotely control the movement of soft robots, lock them into position for as long as needed and later reconfigure the robots into new shapes. They used soft robots made of a polymer embedded with magnetic iron microparticles. Under normal conditions, the material is relatively stiff and holds its shape. However, when the material is heated using light from an LED the polymer becomes pliable the shape of the robot can be changed by remotely […]
A wearable device so thin and soft you won’t even notice it
Science Daily August 2, 2019 A team of researchers in the US (UT Houston, University of Colorado) has developed a multifunctional soft stretchable HMI device based on sol-gel-on-polymer–processed indium zinc oxide (IZO) semiconductor nanomembrane electronics. Stretchable resistive random-access memory (ReRAM) for data storage components as well as field-effect transistors for interfacing and switching circuits, temperature, strain, and ultraviolet sensors are developed. The devices are constructed in an ultrathin (3 to 4 μm) and narrow meandering serpentine-shaped open-mesh configuration, which renders their mechanical stretchability (stable operation up to 30%). It collects signals from the human muscle, directly guides the robot, and […]
What Is ‘Hot Lightning’? Satellites Reveal Which Strikes Are Most Likely to Start Wildfires
IEEE Spectrum August 2, 2019 The U.S. National Lightning Detection Network keeps a record of virtually all lightning that strikes the ground anywhere in the United States. That network is maintained by Helsinki-based Vaisala. The company researchers plan to combine all the data available to them to pinpoint exactly which flashes pose the greatest threat. Lightning that harbors a continuing current is more likely to start fires and damage homes or equipment. A continuing current is not as powerful as the flash itself. While a flash might have a peak current of 20,000 amps (averaged from the multiple composite strokes that […]
Why did my classifier just mistake a turtle for a rifle?
MIT News July 31, 2019 We know instinctively that people and machines see the world differently, but the paper showed that the difference could be isolated and measured. Researchers at MIT have shown that a computer vision model could be compromised in a so-called black-box attack by simply feeding it progressively altered images until one caused the system to fail. Recently they highlighted multiple cases in which classifiers could be duped into confusing cats and skiers for guacamole and dogs, respectively. They trained a model to identify cats based on “robust” features recognizable to humans, and “non-robust” features that humans […]