DARPA April 22, 2022 DARPA’s new Ouija program aims to use sensors on low-orbiting satellites to provide new insights into HF radio wave propagation in the ionosphere. Ouija will augment ground-based measurements with in-situ measurements from space, in very low- Earth orbit (VLEO), to develop and validate accurate, near real-time HF propagation predictions. The VLEO altitude regime is of particular interest due to its information-rich environment where ionospheric electron density is at a maximum. The program includes two technical areas. The first technical area announced in a solicitation, seeks to develop, qualify, launch, and operate multiple small satellites carrying scientific […]
Insights narrow the gap between large-scale atmospheric models and microscale features of atmospheric winds
Phys.org April 26, 2022 Modeling anomalies referred to as grey zone, arise when the model resolution approximates the length scale of turbulence features while modeling the atmosphere. An international team of researchers (USA – Notre Dame, Saudi Arabia) leveraged a new set of one-way nested, full-physics multiscale numerical experiments to quantify the magnitude of the errors introduced at gray zone resolutions in a real-case application. The new set of experiments conducted in Saudi Arabia spanned a wide range of scales and strategies to suppress resolved convection at gray zone resolutions. Detailed analyses of their experiments showed that (i) grid-dependent convective […]
A new guide to extremely powerful light pulses
Phys.org April 26, 2022 An international team of researchers (Germany, Norway) has developed a very compact and highly robust method to compress 1.24 ps pulses to 39 fs by means of only a single spectral broadening stage which neither requires vacuum parts nor custom-made optics. The approach is based on the hybridization of the multiplate continuum and the multipass cell spectral broadening techniques whose combination led to significantly higher spectral broadening factors in bulk material. They used a burst-mode Yb:YAG laser emitting pulses with 80 MW peak power that are enhanced to more than 1 GW after post compression. With only 0.19% rms pulse-to-pulse energy […]
New hardware integrates mechanical devices into quantum tech
Phys.org April 22, 2022 Proposals to combine microwave-frequency mechanical resonators with superconducting devices suggest the possibility of powerful quantum acoustic processors. At present the acoustic platforms lack processors capable of controlling the quantum states of several mechanical oscillators with a single qubit and the rapid quantum non-demolition measurements of mechanical states needed for error correction. Researchers at Stanford University used a superconducting qubit to control and read out the quantum state of a pair of nanomechanical resonators. Their device is capable of fast qubit–mechanics swap operations, which they used to deterministically manipulate the mechanical states. By placing the qubit into […]
A novel insulating state emerges in a 2D material
Nanowerk April 23, 2022 Within the Transition-metal dichalcogenides (TMD) family, iridium ditelluride (IrTe2) is ideally suited for the systematic study of competing factors that can affect a material’s electronic properties. An international team of researchers (USA – Lawrence Berkely National Laboratory, SLAC National Accelerator Laboratory, UC Berkeley, Sandford University, South Korea, Egypt) synthesized bilayer and monolayer IrTe2 samples and characterized their atomic and electronic structures. The analysis of the material showed that monolayer IrTe2 develops a large band gap that’s an order of magnitude larger than is typical for TMD systems, transforming the material into an insulator through the removal […]
Research team follows nearly 8,000 paths towards better cell factories
Phys.org April 26, 2022 The inhibitory compounds found in hydrolysates in biomass substantially influence the performance of a cell factory and the economic feasibility of lignocellulosic biofuels and chemicals. Researchers in Sweden analyzed data on Saccharomyces cerevisiae mutants engineered for altered tolerance towards the most common inhibitors found in lignocellulosic hydrolysates: acetic acid, formic acid, furans, and phenolic compounds. The mutants included in the analysis had been shown to display increased or decreased tolerance to individual inhibitors or combinations of inhibitors found in lignocellulosic hydrolysates. Genetic engineering aimed at improving inhibitor or hydrolysate tolerance altered the specific growth rate or […]
Researchers create exotic magnetic structures with laser light
Phys.org April 25, 2022 To interface skyrmionics with electronic devices requires efficient and reliable ways of creating and destroying such excitations. An international team of researchers (Germany, USA – Flatiron Institute, Sweden) unravel the microscopic mechanism behind ultrafast skyrmion generation by femtosecond laser pulses in transition metal thin films. They employed a theoretical approach based on a two-band electronic model and showed that by exciting the itinerant electronic subsystem with a femtosecond laser ultrafast skyrmion nucleation can occur on a 100 fs timescale. By combining numerical simulations with an analytical treatment, they identified the coupling between electronic currents and the […]
Researchers develop a paper-thin loudspeaker
MIT News April 26, 2022 Ultra-thin, lightweight, high-performance, low-cost, and energy-efficient loudspeakers that can be deployed over a wide area have become increasingly attractive to both traditional audio systems and emerging applications such as active noise control and immersive entertainment. Researchers at MIT have proposed a thin-film loudspeaker based on an active piezoelectric layer embossed with an array of microscale domes. Actuation of the freestanding domes contributes to excellent sound generation by the loudspeaker regardless of the rigid surface on which it is bonded. The acoustic performance is further tunable by designing the dome dimensions. The proposed loudspeaker also exhibits […]
Scientists turn a hydrogen molecule into a quantum sensor
Science Daily April 22, 2022 Researchers at UC Irvine positioned two bound atoms of hydrogen in between the silver tip of the scanning tunneling microscope (STM) and a sample composed of a flat copper surface arrayed with small islands of copper nitride. With pulses of the laser lasting trillionths of a second, they were able to excite the hydrogen molecule and detect changes in its quantum states at cryogenic temperatures and in the ultrahigh vacuum environment of the instrument, rendering atomic-scale, time-lapsed images of the sample. The STM was equipped to detect minute electrical current flowing in this space and […]
Towards sustainable, self-powered energy devices with coconuts
Nanowerk April 25, 2022 An international team of researchers (North Korea, Australia, India) has demonstrated both energy harvesting and storage devices such as piezoelectric nanogenerator (PNG) and piezo supercapacitor (PSC) by enforcing coconut husk (CH) as a filler into the polymer separator. The CH powder was immobilized into the polyvinyl difluoride (PVDF) matrix to improve its piezoelectric performance. The poled PNG with a 7 wt% of CH powder/ PVDF composition delivered an output of 14 V, 50 nA current, and a power density of 0.35 μW/cm2 at 100 MΩ. The output is enough to charge commercial capacitors and power electronic […]