Balloon fleet senses earthquakes from stratosphere

Phys.org  July 28, 2022 Note: This article has been accepted for publication and undergone full peer review but has not been through the copyediting… The ground movements induced by seismic waves create acoustic waves propagating upward in the atmosphere, providing a practical solution to perform remote sensing of planetary interiors. However, a terrestrial demonstration of a seismic network based on balloon-carried pressure sensors has not been provided. Researchers in France reported the detection of a large, distant earthquake in a network of balloon-bound pressure sensors in the stratosphere. They demonstrated that quakes properties and planet internal structure can be probed […]

Cloud study demystifies impact of aerosols

Science Daily  August 1, 2022 Aerosol–cloud interactions have a potentially large impact on climate. The impacts derived from climate models are poorly constrained by observations because retrieving robust large-scale signals of aerosol–cloud interactions is frequently hampered by the considerable noise associated with meteorological co-variability. An international team of researchers (UK, Switzerland, Germany, USA – NASA) disentangled significant signals from the noise of meteorological co-variability using a satellite-based machine-learning approach. Their analysis showed that aerosols from the 2014 Holuhraun effusive eruption in Iceland increased cloud cover by approximately 10%, and this appears to be the leading cause of climate forcing, rather […]

A molecule of light and matter

Science Daily  August 1, 2022 An international team of researchers (Austria, Germany) has observed a mechanical deformation of a cloud of ultracold 87Rb atoms due to the collective interplay of the atoms and a homogenous light field. This collective light scattering resulted in a self-confining potential with interesting features: It exhibited nonlocal properties, attractive for both red- and blue-detuned light fields and induced a remarkably strong force that depends on the gradient of the atomic density. In the article they discuss their experimental observations framework of a theoretical model based on a local-field approach for the light scattered by the […]

Nanoparticles increase light scattering, boost solar cell performance

Phys.org  August 3, 2022 An international team of researchers (USA – Pennsylvania State University, Australia, Italy) has demonstrated that adding any nanomaterial to solar material boosts its efficiency because of the enhanced light scattering as confirmed by theoretical calculations. Adding the nanoparticles boosted the efficiency of perovskite solar cells by 1% in the study. Redistribution of the optical field and consequently a homogenization of the optical field can lead to a reduced photocarrier loss and provide a noticeable photocurrent enhancement (ca. 7%), which explains the general photocurrent improvement in solar cells with nanomaterials…read more. TECHNICAL ARTICLE

Neural networks and ‘ghost’ electrons accurately reconstruct behavior of quantum systems

Phys.org  August 3, 2022 Predicting the properties of a molecule or material requires calculating the collective behavior of its electrons because the electrons can become “quantum mechanically” entangled with one another. The entangled web of connections becomes tricky for even the most powerful computers to unravel directly for any system with more than a handful of particles. An international team of researchers (USA – Res. org., Switzerland) created a way to simulate entanglement by adding to their computations extra “ghost” electrons that interact with the system’s actual electrons. The behavior of the added electrons is controlled by neural network. The […]

New optical switch could lead to ultrafast all-optical signal processing

Phys.org  August 1, 2022 The weak native nonlinearity of most nanophotonic platforms has imposed barriers for the use of optical nonlinear functions for applications in integrated photonics, including all-optical information processing, photonic neural networks, and on-chip ultrafast light sources, by necessitating large driving energies, high-Q cavities, or integration with other materials with stronger nonlinearity. A team of researchers in the US (Caltech, Cornell University) has effectively utilized the strong and instantaneous quadratic nonlinearity of lithium niobate nanowaveguides for the realization of cavity-free all-optical switching. By simultaneous engineering of the dispersion and quasi-phase matching, they designed and demonstrated a nonlinear splitter […]

A paper battery with water switch

Nanowerk  July 29, 2022 Researchers in Switzerland have developed a disposable paper battery aiming to reduce the environmental impact of single-use electronics for applications such as point of care diagnosis, smart packaging, and environmental sensing. The battery uses Zinc as a biodegradable metal anode, graphite as a nontoxic cathode material and paper as a biodegradable substrate. To facilitate additive manufacturing, they developed electrodes and current collector inks that can be stencil printed on paper to create water-activated batteries of arbitrary shape and size. The battery remains inactive until water is provided and absorbed by the paper substrate, taking advantage of […]

Researchers 3D print high-performance nanostructured alloy that’s both ultrastrong and ductile

Science Daily  August 3, 2022 The additive manufacture of metal alloys by laser powder bed fusion (L-PBF) involves large temperature gradients and rapid cooling which enables microstructural refinement at the nanoscale to achieve high strength. However, high-strength nanostructured alloys produced by laser additive manufacturing often have limited ductility. A team of researchers in the US (UMass Amherst, Georgia Institute of Technology, Texas A&M, Oak Ridge National Laboratory, Rice University, Lawrence Livermore National Laboratory, UCLA) used L-PBF to print dual-phase nanolamellar high-entropy alloys (HEAs) of AlCoCrFeNi that exhibit a combination of a high yield strength of about 1.3 gigapascals and a large […]

Researchers create biosensor by turning spider silk into optical fiber

Phys.org  August 2, 2022 Researchers in Taiwan harvested dragline spider silk from the giant wood spider Nephila pilipes, which is native to Taiwan. They enveloped the silk, which is just 10 microns in diameter, with a biocompatible photocurable resin and cured it to form a smooth protective surface creating an optical fiber structure that was 100 microns in diameter, with the spider silk acting as the core and the resin as the cladding. They added a biocompatible nano-layer of gold to enhance the fiber’s sensing abilities. This process formed a thread-like structure with two ends. To use the fiber to […]

Researchers measure the binding state of light and matter for the first time

Phys.org  August 1, 2022 Light-matter interaction is well understood on the single-atom level and routinely used to manipulate atomic gases. However, in denser ensembles, collective effects emerge that are caused by light-induced dipole-dipole interactions and multiple photon scattering. An international team of researchers (Austria, Germany) found a mechanical deformation of a cloud of ultracold 87Rb atoms due to the collective interplay of the atoms and a homogenous light field. The collective light scattering results in a self-confining potential which exhibits nonlocal properties, attractive for both red- and blue-detuned light fields and induces a remarkably strong force that depends on the […]