Phys.org November 24, 2020 THz absorbers with strong absorption, broad-band absorption bandwidth and tunable characteristics have attracted the attention of many researchers with extensive application prospects in THz wave shielding, THz imaging, and THz sensitive thermal detecting. Researchers in China introduced strongly correlated electron material VO2 as a functional layer and realized the broad-band tunable THz spectrum properties in the device. The conductivity, dielectric constant, as well as optical properties got a dramatic switching during the insulator-metal transition at TC = 340 K, and the transition could be tuned by temperature, electric field, and light. The device had a 74% […]
Researchers model urban airflows to help improve the design of drones, skyscrapers, and natural ventilation systems
Phys.org November 25, 2020 Scientists presented the latest findings on modeling and predicting urban airflow at the 73rd Annual Meeting of the American Physical Society’s Division of Fluid Dynamics in the hope of building better buildings, cities, and transportation. According to the scientists in addition to the challenges of traffic congestion and obstacles, critical technology gaps exist in modeling, detecting, and accommodating the dynamic urban local wind fields as well as in precision navigation through uncertain weather conditions. They attached sensors to robotic aircraft to take more cohesive measurements of building wakes, or the disturbed airflow around buildings. They combined […]
Scientists Detect ‘Superbolts’ 1,000 Times Brighter Than Typical Lightning Strikes
Science Alert November 24, 2020 Researchers at the Los Alamos National Laboratory used Fast On-Orbit Detection of Transient Events (FORTE) satellite observations to identify superbolt-class optical lightning events and evaluate their origins. Superbolts have been defined as lightning pulses whose peak optical power exceeds 1011 W. However, it has been unclear whether superbolts resulted from particular types of high-energy lightning process or whether they were the result of measurement bias. According to their 12-year analysis of FORTE superbolt detections indicates that the lower optical superbolt energy range (~100 GW) is dominated by normal lightning, but brighter cases are predominantly strong […]
Self-diagnostic carbon nanocomposites
Nanowerk November 23, 2020 Studies have shown that carbon nanomaterials can increase required mechanical properties with relatively small addition amounts, all the while allowing the final material to be electrically conductive and piezoresistive in nature but their incorporation into large scale production requires intensive facility upgrades. Researchers in Russia used masterbatches and industrially available, inexpensive manufacturing techniques to examine how the addition of carbon nanoparticles can change the electric conductivity of polymer matrices. Essentially, the use of such materials has the potential to replace sensors in weight critical systems such as aircraft structures, with the material itself being able to […]
Shift in atmospheric rivers could affect Antarctic sea ice, glaciers
Science Daily November 23, 2020 Researchers at UCLA investigated the atmospheric river (AR) frequency trends over the Southern Hemisphere using three reanalyses and two Community Earth System Model (CESM) ensembles. Their results show that AR frequency has been increasing over the Southern Ocean and decreasing over lower latitudes in the past four decades and that ARs have been shifting poleward. While the observed trends are mostly driven by the poleward shift of the westerly jet, the experiments indicate anthropogenic forcing would result in positive AR frequency trends over the Southern Ocean due mostly to moisture changes. They conclude that the […]
Topological mechanical metamaterials go beyond Newton’s third law
Phys.org November 19, 2020 An international team of researchers (Israel, Los Alamos) found a way to mimic non-Newtonian behavior in mechanical systems, and thereby develop a mechanical implementation for some of the more intractable topological quantum systems, which may offer fundamentally new insights into both the mechanical and quantum topological systems. The unit cells in a mechanical lattice are subjected to active feedback forces that are processed through autonomous controllers, pre-programmed to generate the desired local response in real-time. They demonstrated that the required topological phase, characterized by chiral edge modes, can be achieved in an analogous mechanical system only […]
This Weird, Cheap Quantum Device Can Run For a Year With a Single Kick of Energy
Science Alert November 22, 2020 Continuous, battery-free operation of sensor nodes requires ultra-low-power sensing and data-logging techniques. According to the researchers at Washington University by directly coupling a sensor/transducer signal into globally asymptotically stable monotonic dynamical systems based on Fowler-Nordheim quantum tunneling, it is possible to achieve self-powered sensing at an energy budget that is currently unachievable using conventional energy harvesting methods. They have developed a device that uses a differential architecture to compensate for environmental variations and the device can retain sensed information for durations ranging from hours to days. With a theoretical operating energy budget less than 10 […]
Top 10 Science and Technology Inventions for the Week of November 20, 2020
01. Novel magnetic spray transforms objects into millirobots for biomedical applications (with video) 02. Analysis paves way for more sensitive quantum sensors 03. New fiber optic sensors transmit data up to 100 times faster 04. No losses: Scientists stuff graphene with light 05. Quantum algorithm breakthrough 06. Ultra-fast polymer modulators that can take the heat 07. Engineering a Way Out of Climate Change: Genetically Modified Organisms Could be the Key 08. New technology allows more precise view of the smallest nanoparticles 09. Order from chaos 10. The troubling rise of facial recognition technology (podcast; 35 minutes) And others… New technique […]
Scientists Discover Exotic New Mineral Forged in The Furnace of a Russian Volcano
Science Alert November 18, 2020 The ‘Great Tolbachik Fissure Eruption’ of 1975–1976, and a second, lesser follow-up that took place between 2012–2013 opening rocky terrain to 130 unknown minerals which were identified. researchers in Russia have identified the latest one, petrovite, a sulfate mineral that takes shape as blue globular aggregates of tabular crystals, many holding gaseous inclusions. The copper atom in the crystal structure of petrovite has an unusual and rare coordination of seven oxygen atoms. At the chemical level, petrovite represents a new type of crystal structure. Its molecular framework – consisting of oxygen atoms, sodium sulphur and […]
Analysis paves way for more sensitive quantum sensors
Nanowerk November 16, 2020 Researchers at the University of Chicago proposed creating a string of photonic cavities, where photons can be transported to adjacent cavities. Such a string could be used as a quantum sensor. By harnessing non-Hermitian dynamics, where dissipation leads to interesting consequences, they were able to calculate that a string of these cavities would increase the sensitivity of the sensor much more than the number of cavities added. In fact, it would increase the sensitivity exponentially in system size. To prove the theory, they are building a network of superconducting circuits that can move photons between cavities. […]