SciTech Daily December 29, 2021 By combining atomistic models with kinetic Monte Carlo simulations, researchers at Rice University have shown that a pristine carbon nanotube under ambient working conditions is essentially indefatigable accumulating no structural memory of prior load; over time, it probabilistically breaks, abruptly. However, by using coarse-grained modeling they demonstrated that any practical assemblies of nanotubes, e.g., bundles and fibers, display a clear gradual strength degradation in cyclic tensile loading due to recurrence and ratchet-up of slip at the tube-tube interfaces, not occurring under static load even of equal amplitude. They hope to give researchers and industry a […]
New data-decoding approach could lead to faster, smaller digital tech
Phys.org December 28, 2021 An international team of researchers (USA – University of Nebraska, University of Wisconsin, China) has shown that spin-independent conductance in compensated antiferromagnets and normal metals can be efficiently exploited in spintronics, provided their magnetic space group symmetry supports a non-spin-degenerate Fermi surface. Due to their momentum-dependent spin polarization, such antiferromagnets can be used as active elements in antiferromagnetic tunnel junctions (AFMTJs) and produce a giant tunneling magnetoresistance (TMR) effect. Using RuO2 as a representative compensated antiferromagnet exhibiting spin-independent conductance they designed a RuO2/TiO2/RuO2 (001) AFMTJ, where a globally spin-neutral charge current was controlled by the two […]
No more annual flu shot? New target for universal influenza vaccine
Science Daily December 22, 2021 An international team of researchers (USA – University of Chicago, The Scripps Research Institute, La Jolla, CA, Icahn School of Medicine at Mount Sinai, New York, Fred Hutchinson Cancer Research Center, Seattle, WA, University of Washington, University of Maryland, Austria) has found a distinct class of broadly neutralizing antibodies (bnAbs) targeting a discrete membrane-proximal anchor epitope of the hemagglutinin (HA) stalk domain. The antibodies are broadly neutralizing across H1 viruses and can cross-react with pandemic-threat H2 and H5 viruses. Anchor epitope-targeting B cells are common in the human memory B cell (MBC) repertoire and were […]
Scientists find ways to help perovskite solar cell ‘self-healing’
Nanowerk December 28, 2021 Organic-inorganic hybrid perovskite solar cells, considered as a competitive alternative to conventional silicon solar cells, are prone to degrade when exposed to air. An international team of researchers (China, Greece, Australia) introduced PVP to the methylammonium lead iodide perovskite precursor. It can control crystal growth and endow the devices with self-healing ability in a moisture environment. When it was introduced in perovskite solar cells, it acted as a protective armor with an automatic blood backflow effect against water vapor. In addition, PVP can improve crystal growth with fewer defects and larger grains…read more. TECHNICAL ARTICLE
Scientists invent lead-free composite shielding material for neutrons and gamma-rays
Phys.org December 23, 2021 Through a series of intricate and comprehensive experiments researchers in China tested and certified the composite, modified-gadolinium oxide/boron carbide/high density polyethylene (Gd2O3/B4C/HDPE) as safe and effective to shield neutron and gamma rays. Fast neutrons collide with gadolinium (Gd) inelastically and collide elastically with hydrogen until they become thermal neutrons, finally, absorbed by high Z element Gd and boron. The experimental results show that the neutron shielding rate of the composite can reach 98% under the condition of 15 cm thickness in CF-252 environment. In cS-137 and CO-60 environments, the gamma shielding rates of the composite are […]
Speeding up directed evolution of molecules in the lab
MIT News December 30, 2021 Evolution is commonly used to engineer proteins and RNA, but experimental constraints have limited the ability to reproducibly and reliably explore factors such as population diversity, the timing of environmental changes and chance on outcomes. Researchers at MIT have developed a robotic platform termed phage- and robotics-assisted near-continuous evolution (PRANCE) to comprehensively explore biomolecular evolution by performing phage-assisted continuous evolution in high-throughput. PRANCE implements an automated feedback control system that adjusts the stringency of selection in response to real-time measurements of each molecular activity. In evolving three distinct types of biomolecule, they found that evolution […]
Top 10 Science and Technology Inventions for the Week of December 24, 2021
01. Magnetic ‘hedgehogs’ could store big data in a small space 02. Moments of silence point the way towards better superconductors 03. New materials for quantum technologies 04. Novel biosensors set to revolutionize brain-controlled robotics 05. Light-controlled spontaneous growth of nanostructures 06. Quantum marbles in a bowl of light 07. Redrawing the lines: Growing inexpensive, high-quality iron-based superconductors 08. Researchers develop new measurements for designing cooler electronics 09. Scientists successfully manipulate a single skyrmion at room temperature 10. Study shows that zwitterions can raise the dielectric constant of soft materials And others… MIT engineers produce the world’s longest flexible fiber […]
Light-controlled spontaneous growth of nanostructures
Phys.org December 17, 2021 Researchers in the Netherlands have demonstrated that by illuminating a solution of barium carbonate and silicon with UV light they can control when and which structures arise at the micrometer scale. As soon as barium carbonate crystals form in the solution, the silicon joins in and precipitates together with the crystals, thus giving rise to the unusual shapes. A tiny bit of CO2 gas in the solution starts this process. If one could ensure that CO2 arises at the exact location and time desired, this would result in an on-off switch for the chemical reaction. Using […]
Magnetic ‘hedgehogs’ could store big data in a small space
Nanowerk December 17, 2021 An international team of researchers (USA- Ohio State University, Mexico) used a magnetic microscope to visualize the patterns formed in thin films of manganese germanide. The magnetism in this material follows helices, like the structure of DNA which leads to numerous patterns. The images revealed that in certain parts of the sample, the magnetism at the surface was twisted into a pattern resembling the spikes of a hedgehog, about 50 nanometers in size. The hedgehog patterns could be shifted on the surface with electric currents or inverted with magnetic fields. This foreshadows the reading and writing […]
MIT engineers produce the world’s longest flexible fiber battery
MIT News December 20, 2021 Fibers as fundamental building blocks of fabrics and 3D-printed objects provide unique opportunities for developing pervasive multidimensional power systems. An international team of researchers (USA – MIT, US Army, South Korea) has developed a Li-ion battery fiber, fabricated using a thermal drawing method which occurs with simultaneous flows of multiple complex electroactive gels, particles, and polymers within protective flexible cladding. This top-down approach allows to produce fully functional and arbitrarily long lithium-ion fiber batteries. The continuous 140 m fiber battery demonstrated a discharge capacity of ∼123 mAh and discharge energy of ∼217 mWh. The scalability […]