Science Daily August 11, 2021 Researchers at the Michigan Technological University have developed a comprehensive reactive activity model that shows how singlet oxygen’s reaction mechanisms perform against a diverse group of contaminants and computes their half-life in a natural aquatic environment. The rate of indirect-sunlight-initiated chemical oxidation is unique to the body of water; singlet oxygen plays a partial role in degrading the toxins in harmful algal blooms and in breaking down the excess nitrogen and phosphorus produced by agricultural runoff. It can oxidize chemicals in drinking water or wastewater treatments. With the half-life calculations established by their model, the […]
Author Archives: Hema Viswanath
Metamaterials research challenges fundamental limits in photonics
Phys.org August 10, 2021 Previous research was limited to modifying either absorption or refraction in metamaterials. Researchers at Cornell University have demonstrated that if both properties are modulated in time, it is possible to absorb electromagnetic waves much more efficiently than in a static structure, or in a structure in which either one of these two degrees of freedom is modulated individually. They combined these two aspects together to create a much more effective system. The findings may lead to the development of new metamaterials with wave absorption and scattering properties that far outperform what is currently available. The research […]
Minor volcanic eruptions could ‘cascade’ into global catastrophe
Science Daily August 6, 2021 The typical focus of attention for global-scale catastrophes has been on large-scale eruptions with a volcanic explosivity index (VEI) of 7–8. An international team of researchers (UK, Israel) has identified seven “pinch points” where clusters of relatively small but active volcanoes sit alongside vital infrastructure that, if paralyzed, could have catastrophic global consequences. They include, the volcanic group on the northern tip of Taiwan, the home to one of the largest producers of electronic chips; The Mediterranean, where earthquakes can induce tsunamis that smash submerged cable networks and seal off the Suez Canal; eruptions in […]
New device can diagnose Covid-19 from saliva samples
MIT News August 6, 2021 A team of researchers in the US (Harvard University, MIT, Boston Children’s Hospital, Beth Israel Deconus Hospital, Mass General Hospital) has developed a low-cost, self-contained, POC diagnostic called miSHERLOCK (minimally instrumented SHERLOCK) that is capable of concurrent universal detection of SARS-CoV-2 as well as specific detection of the B.1.1.7, B.1.351, or P.1 variants. The miSHERLOCK platform integrates an optimized one-pot SHERLOCK reaction with an RNA paper-capture method compatible with in situ nucleic acid amplification and Cas detection. miSHERLOCK combines instrument-free, built-in sample preparation from saliva, room temperature stable reagents, battery-powered incubation, and simple visual and […]
New electronic phenomenon discovered
Science Daily August 11, 2021 A team of researchers in the US (University of North Florida, University of Illinois, Arizona State University) has demonstrated a new electronic phenomenon they call “asymmetric ferroelectricity” in atomic layer superlattices constructed using three constituent phases, CaTiO3, SrTiO3 and BaTiO3. The stacking sequence of the atomic layers is found to control the symmetry of the high-temperature dielectric response. When a nanostructured asymmetric strain is programmed into the lattice via the stacking order, the natural symmetry at high temperatures is removed and a polarized sample is obtained in which the polarization increases as the temperature is […]
Non-line-of-sight imaging with picosecond temporal resolution
Phys.org August 12, 2021 Non-line-of-sight (NLOS) imaging enables monitoring around corners and is promising for diverse applications. The resolution of transient NLOS imaging is limited to a centimeter scale, mainly by the temporal resolution of the detectors. Researchers in China have constructed an up-conversion single-photon detector with a high temporal resolution of ∼1.4 ps and a low noise count rate of 5 counts per second (cps). The detector operates at room temperature, near-infrared wavelength. They demonstrated high-resolution and low-noise NLOS imaging. The system can provide a 180 μm axial resolution and a 2 mm lateral resolution, which is more than […]
Protecting earth from space storms
Phys.org August 11, 2021 In 2020 NSF and NASA created the Space Weather with Quantified Uncertainties (SWQU) program. The main change in version 2 was the refinement of the numerical grid in the magnetosphere, several improvements in the algorithms, and a recalibration of the empirical parameters. The Geospace Model provides only about 30 minutes of advanced warning. Researchers at the University of Michigan are working to increase lead time to one to three days. They hope to start from the Sun, using remote observation of the Sun’s surface instead of the current data from a satellite measuring plasma parameters one […]
Quantum materials cloak thermal radiation
Nanowerk August 11, 2021 For most solids, the thermally emitted power increases monotonically with temperature in a one-to-one relationship that enables applications such as infrared imaging and noncontact thermometry. A team of researchers in the US (University of Wisconsin–Madison, Harvard University, Purdue University, Brookhaven National Laboratory) has demonstrated that ultrathin thermal emitters that violate this one-to-one relationship via the use of samarium nickel oxide (SmNiO3), a strongly correlated quantum material that undergoes a fully reversible, temperature-driven solid-state phase transition. Due to the smooth and hysteresis-free nature of this unique insulator-to-metal phase transition enabled them to engineer the temperature dependence of […]
Scientists develop chain mail fabric that can stiffen on demand
Science Daily August 12, 2021 Structured fabrics, such as woven sheets or chain mail armours, design can target desirable characteristics, such as high impact resistance, thermal regulation, or electrical conductivity. However, the properties are usually fixed. An international team of researchers (Singapore, USA – Caltech) has developed new chain fabric that is flexible like cloth but can stiffen on demand. It comprises hollow octahedrons that interlock with each other. Increase in bending resistance arises because the interlocking particles have high tensile resistance. They found that chain mails, consisting of different non-convex granular particles, undergo a jamming phase transition that is […]
Single-step synthesis of solid-state sensors for detecting explosives
Nanowerk August 12, 2021 Most existing techniques to detect nitroaromatic compounds cannot be used in practical situations. Conventional methods available for the formulation of aggregation-induced emission (AIE) polymers are highly complicated, involving multi-step purification processes, proving detrimental in the application of AIE polymer-based probes. Researchers in South Korea have developed a single step protocol that produces tetraphenylethylene-hyperbranched polyglycidol (TPE-HPG) polymer solution that is added to water for formation of bright blue fluorescent TPE-HPG aggregated nanoparticles. Through empirical analysis, the researchers observed that the strong blue fluorescence of these nanoparticles is quenched by almost 95% on addition of 90 µM concentration […]