01. Exploiting non-line-of-sight paths for terahertz signals in wireless communications 02. Flexible, easy-to-scale nanoribbons move graphene toward use in tech applications 03. A material keyboard made of graphene 04. UVA engineering computer scientists discover new vulnerability affecting computers globally 05. Researchers confront major hurdle in quantum computing 06. Researchers produce laser pulses with record-breaking intensity 07. Superconductivity, high critical temperature found in 2D semimetal tungsten nitride 08. Thin, large-area device converts infrared light into images 09. An uncrackable combination of invisible ink and artificial intelligence 10. ‘Bat-sense’ tech generates images from sound And others… Climate change: Amazon may be turning […]
‘Bat-sense’ tech generates images from sound
Phys.org April 30, 2021 Full 3D information based on echo-location requires some form of scanning of the scene to provide the spatial location of the echo origin-points. Without this spatial information, imaging objects in 3D is a challenging task as the inverse retrieval problem is strongly ill-posed. Researchers in the UK showed that the temporal information encoded in the return echoes that are reflected multiple times within a scene is sufficient to faithfully render an image in 3D. Numerical modelling and an information theoretic perspective proved the concept and provided insight into the role of the multipath information. They experimentally […]
Climate change: Amazon may be turning from friend to foe
Phys.org April 30, 2021 Spatial–temporal dynamics of aboveground biomass (AGB) and forest area affect the carbon cycle, climate, and biodiversity in the Brazilian Amazon. An international team of researchers (USA – University of Oklahoma, Caltech, Lawrence Berkeley National Laboratory, France, Denmark, China, UK) investigated interannual changes in AGB and forest area by analysing satellite-based annual AGB and forest area datasets. They found that the gross forest area loss was larger in 2019 than in 2015, possibly due to recent loosening of forest protection policies. However, the net AGB loss was three times smaller in 2019 than in 2015. During 2010–2019, […]
DARPA Selects Teams to Defend Against Chemical, Biological Threats from Inside and Out
DARPA News April 19, 2021 DARPA’s Personalized Protective Biosystem (PPB) aims to address PPE limitations, including threat-specific vulnerabilities, thermal/logistical burdens, and potential exposure risk. The five-year program is divided into two technical areas (TAs). TA1 technologies aim to prevent external contact between the threat and the body, providing 100% survival against more than 10 CB agents with smart, lightweight materials. TA2 technologies will neutralize threats at vulnerable internal tissue barriers (i.e., skin, airway, ocular) using a configurable countermeasure. DARPA recently awarded contracts to develop lightweight materials and adaptable, tissue-protective countermeasures to provide on-demand, broad spectrum, and rapid long-term protection. Performers […]
Exploiting non-line-of-sight paths for terahertz signals in wireless communications
EurekAlert April 27, 2021 A team of researchers in the US (Rice University, Brown University) investigated the idea of harnessing these specular NLOS (Non-Line-Of-Sight) paths for communication in directional networks at frequencies above 100 GHz. They explored several illustrative transmitter architectures, such as conventional substrate-lens dipole antenna and a leaky-wave antenna, to learn how these high-gain directional antennas offer both new challenges and new opportunities for exploiting NLOS paths. The results demonstrated the sensitivity to antenna alignment, power spectrum variations, and the disparity in supported bandwidth of various line-of-sight (LOS) and reflected path configurations. They showed that NLOS paths can, […]
Flexible, easy-to-scale nanoribbons move graphene toward use in tech applications
Science Daily May 3, 2021 Silicon-based fiber optics are currently the best structures for high-speed, long distance transmissions, but graphene could improve performance even more. Researchers at the University of Wisconsin created a scalable fabrication technique to make the smallest graphene ribbon structures. They found that to improve graphene’s performance is to cut it into microscopic, nanometer-scale ribbon structures, which act as tiny antennas that interact with light. The smaller the antenna, the higher energies of light it interacts with. As the ribbon width decreases, so does the resonant wavelength of light. Lower wavelengths mean higher energies, and their devices interacted […]
Intranasal influenza vaccine enhances immune response and offers broad protection
Science Daily May 3, 2021 Soluble protein vaccines are poorly immunogenic if administered by an intranasal route. A team of researchers in the US (Georgia State University, Emory University) developed an intranasal influenza vaccine using recombinant hemagglutinin (HA), a protein found on the surface of influenza viruses, as the antigen component of the vaccine. HA is integral to the ability of influenza virus to cause infection. They also created a two-dimensional nanomaterial (polyethyleneimine-functionalized graphene oxide nanoparticles) and found that it displayed potent immunoenhancing effects on influenza vaccines delivered intranasally. The study, conducted in mice and cell culture, found the nanoparticles significantly […]
A material keyboard made of graphene
Phys.org May 5, 2021 An international team of researchers (Switzerland, Japan) put two layers graphene flakes on top of each other and made a magic angle of exactly 1.06 degrees. The atomic crystal lattices of the graphene flakes created a moiré pattern. They attached several additional electrodes on top of the magic angle graphene flakes to apply an electric voltage to the material. By applying different voltages to the individual electrodes, they turned the magic angle graphene into an insulator in one spot, but a few hundred nanometres to one side it becomes a superconductor. For possible uses in quantum […]
A new method to trigger rain where water is scarce
Phys.org May 6, 2021 Artificial charge release is an unexplored potential geoengineering technique for modifying fogs, clouds, and rainfall. To evaluate the effectiveness of the method an international team of researchers (UK, Finland) developed a small charge-delivering remotely piloted aircraft. It carried controllable bipolar charge emitters (nominal emission current ±5 μA) beneath each wing, with optical cloud and meteorological sensors integrated into the airframe. Meteorological and droplet measurements were demonstrated to 2 km altitude by comparison with a radiosonde, including within cloud, and successful charge emission aloft verified by using programmed flight paths above an upward-facing surface electric field mill. […]
Researchers confront major hurdle in quantum computing
Phys.org May 5, 2021 To realize the full potential of quantum computing high-fidelity information transfer mechanisms are required for quantum error correction and efficient algorithms – and that presents a major experimental challenge. A team of researchers in the US (University of Rochester, Virginia Tech, Purdue University) demonstrated adiabatic quantum state transfer (AQT) which is not affected by pulse errors and noise. They exploited entanglement even when the particles are separated by a large distance to transfer one electron’s quantum spin state across a chain of four electrons in semiconductor quantum dots. AQT is robust against pulse errors and noise. […]