Nanowerk June 10, 2021 An international team of researchers (Israel, Spain, France, USA – Kansas State University) shone pulses of light along the edge of a 2D material, producing in the material the hybrid sound-light waves. Not only were they able to record these waves, but they also found the pulses could spontaneously speed up and slow down. Surprisingly, the waves even split into two separate pulses, moving at different speeds. They developed a new technique to image the motion of light without disturbing it. According to the researchers having access to the full spatiotemporal dynamics of 2D wave packets […]
Author Archives: Hema Viswanath
Leading scientists warn of global impacts as Antarctic nears tipping points
Phys.org June 16, 2021 According to a panel of leading Antarctic scientists human-driven climate change is pushing the Antarctic towards numerous tipping points that will impact wider earth systems, with profound implications for humanity and biodiversity. They examine how climate change is rapidly pushing five critical, interconnected processes in the Antarctic Southern Ocean towards substantial changes. They warn that disrupting these processes may disproportionately exacerbate global climate change and have widespread impacts on marine and human life worldwide, due to the region’s central role in regulating our earth systems. According to the group we can build resilience in the Antarctic […]
Let there be light! New tech allows people to see in the dark
Nanowerk June 10, 2021 Conventional infrared imaging technologies require the use of materials such as narrow bandgap semiconductors, which are sensitive to thermal noise and often require cryogenic cooling. An international team of researchers (Australia, Italy, UK, Germany, France, Bulgaria) developed and demonstrated a proof-of-concept compact all-optical device to perform infrared imaging in a metasurface composed of GaAs semiconductor nanoantennas using a nonlinear wave-mixing process. Experimentally they showed the upconversion of short-wave infrared wavelengths via the coherent parametric process of sum-frequency generation. In this process, an infrared image of a target is mixed inside the metasurface with a strong pump […]
Lightning impacts edge of space in ways not previously observed
Science Daily June 14, 2021 A team of researchers in the US (New Mexico Tech, University of Central Florida) working with data collected by the Incoherent Scatter Radar (ISR) at the Arecibo Observatory, satellites, and lightning detectors in Puerto Rico, have for the first time examined the simultaneous impacts of thunderstorms and solar flares on the ionospheric D-region. One of the key things they showed in the paper is that lightning- and solar flare-driven signatures are completely different. The first tends to deplete electron density depletions, while the second enhances. They determined that solar flares and lightning from thunderstorms trigger […]
New advanced material shows extraordinary stability over wide temperature range
Phys.org June 14, 2021 Researchers in Australia have demonstrated that the zero thermal expansion material made of scandium, aluminum, tungsten, and oxygen did not change in volume from 4 to 1400 Kelvin (-269 to 1126 °Celsius). They confirmed the structural stability of Sc1.5Al0.5W3O12 with only minute changes to the bonds, position of oxygen atoms and rotations of the atom arrangements which appear to be undertaken cooperatively. The crystallographic data from the diffraction experiments reflects the combination of subtle but observable distortions of the polyhedral units, bond lengths, angles and oxygen atoms that allow the material to absorb temperature changes. It […]
Predicting the evolution of a pandemic
Phys.org June 15, 2021 An international team of researchers (Kuwait, USA – NIST, Saudi Arabia) has developed a susceptible-exposed-infected-recovered model (SEIR) with a vaccination compartment proposed to simulate theCOVID-19 spread in Saudi Arabia. The model considers seven stages of infection: susceptible (S), exposed (E), infectious (I), quarantined (Q), recovered (R), deaths (D), and vaccinated (V). As numerical models can be subject to various sources of uncertainties, they used the ensemble Kalman filter (EnKF) to constrain the model outputs and its parameters with available data. They conducted joint state-parameters estimation experiments assimilating daily data into the proposed model using the EnKF […]
Researchers uncover unique properties of a promising new superconductor
Science Daily June 16, 2021 An international team of researchers (USA – University of Minnesota, Pennsylvania State University, Cornell University, National High Magnetic Field Laboratory, China, Switzerland) found that Niobium diselenide (NbSe2) in 2D form is a more resilient superconductor because it has a two-fold symmetry, which is very different from thicker samples of the same material. Despite the six-fold structure, it only showed two-fold behavior in the experiment. They attributed the newly discovered two-fold rotational symmetry of the superconducting state in NbSe2 to the mixing between two closely competing types of superconductivity, namely the conventional s-wave type — typical of […]
Scientists demonstrate perfect light absorption by single nanoparticle
Nanowerk June 15, 2021 Previously researchers succeeded in demonstrating the phenomenon of perfect absorption in large bodies of matter that were several times the size of a light beam. But the question remained unsolved was – whether the same was possible for miniature objects. An international team of researchers (Russia, Sweden) calculated the properties of a small object that could completely absorb all incidental light. They succeeded in reducing this complex analytical task to a simpler one – a Fredholm integral equation of the second kind. Having solved it, they found the ideal combination of particle and light properties that […]
Scientists make highly maneuverable miniature robots controlled by magnetic fields
EurekAlert June 14, 2021 Researchers in Singapore created miniature robots by embedding magnetic microparticles into biocompatible polymers which are ‘programmed’ to execute their desired functionalities when magnetic fields are applied. They discovered the third and final principal vector of the magnetic fields, which is critical for controlling such machines. The robots have six degrees of freedom, rotate 43 times faster and they can be made with ‘soft’ materials hence replicate important mechanical qualities, ability to grip and precisely pick and place miniature objects. Other features include the remote control, ability to swim through barriers, and assemble structures, precise orientation control, […]
UNESCO report calls for investments in science in the face of growing crises
Phys.org June 11, 2021 Spending on science worldwide increased (+19 percent) between 2014 and 2018, as did the number of scientists (+13.7 percent). This trend has been further boosted by the COVID crisis, according to UNESCO’s new science report, UNESCO Science Report – The Race against Time for Smarter Development. But these figures hide significant disparities: Just two countries, the United States and China, account for nearly two-thirds of this increase (63 percent) while 4 out of 5 countries lag far behind, investing less than 1 percent of their GDP in scientific research. The scientific landscape thus remains largely a […]