Phys.org August 18, 2023 An international team of researchers (USA – University of Arkansas, UC Berkeley, Spain) theoretically considered a graphene ripple as a Brownian particle coupled to an energy storage circuit. When circuit and particle are at the same temperature, the second law forbids harvesting energy from the thermal motion of the Brownian particle, even if the circuit contains a rectifying diode. However, when the circuit contains a junction followed by two diodes wired in opposition, the approach to equilibrium may become ultraslow. Detailed balance is temporarily broken as current flows between the two diodes and charges storage capacitors. […]
Collecting clean water from fog
Science Daily August 16, 2023 An international team of researchers (Switzerland, Germany, USA – UC Berkeley) has demonstrated a rationally designed system that can capture fog at high efficiency while simultaneously degrading organic pollutants. Their design consists of a wire mesh coated with anatase titanium dioxide nanoparticles embedded in a polymer matrix. Once activated by sunlight, the photoactive titanium dioxide layer decomposed organic molecules such as diesel, even in the absence of sunlight. The wettability of the mesh surface was engineered to enhance water extraction. In outdoor tests, the device could maintain a good fog harvesting performance as well as […]
DOD Biodefense Posture Review Released
Global Biodefense August 17, 2023 The U.S. Department of Defense today released the Biodefense Posture Review outlining reforms aimed to posture the DOD in the face of future biothreats through 2035. It outlines significant reforms and lays the foundation for a resilient total force that deters the use of bioweapons, rapidly responds to natural outbreaks, and minimizes the global risk of laboratory accidents. It addresses Naturally Occurring Biological Threats, Accidental Biological Threats, Deliberate Biological Threats, Emerging and Disruptive Technologies, and Risks from Bioincidents. Lines of Effort to Drive Biodefense Actions include, Enhance early warning and understanding to counter biothreats Coordinate […]
Machine-learning system based on light could yield more powerful, efficient large language models
MIT News August 22, 2023 Optical neural networks (ONNs) have recently emerged to process deep neural networks (DNN) tasks with high clock rates, parallelism, and low-loss data transmission. However, existing challenges for ONNs are high energy consumption due to their low electro-optic conversion efficiency, low compute density due to large device footprints and channel crosstalk, and long latency due to the lack of inline nonlinearity. An international team of researchers (USA – MIT, UCLA, industry, Germany) experimentally demonstrated a spatial-temporal-multiplexed ONN system that simultaneously overcomes all these challenges. They exploited neuron encoding with volume-manufactured micrometre-scale vertical-cavity surface-emitting laser (VCSEL) arrays […]
Microscopic transformations of electrocatalyst surfaces
Nanowerk August 18, 2023 Potentiodynamic methods that induce structural changes in Cu catalysts for the electrochemical reduction of CO2 (CO2RR) have been identified as a promising strategy for steering the catalyst selectivity towards the generation of multi-carbon products. In the current approaches, active species are created via a sequential Cu oxidation–reduction process. Researchers in Germany have shown that low-coordinated Cu surface species form spontaneously near the onset of CO2 electrocatalytic reduction. This process started by CO-induced Cu nanocluster formation in the initial stages of the reaction, led to irreversible surface restructuring that persisted over a wide potential range. On subsequent […]
Move over lithium-ion: Zinc-air batteries a cheaper and safer alternative
Science Daily August 21, 2023 An international team of researchers (Australia, Saudi Arabia) has developed a nanocomposite based on ternary CoNiFe-layered double hydroxides (LDH) and cobalt coordinated and N-doped porous carbon (Co-N-C) network, obtained by the in-situ growth of LDH over the surface of ZIF-67-derived 3D porous network. Co-N-C network contributes to the oxygen reduction reaction activity, while CoNiFe-LDH imparts to the oxygen evolution reaction activity. The rich active sites and enhanced electronic and mass transport properties stemmed from their unique architecture, culminated into outstanding bi-functional catalytic activity towards oxygen evolution/reduction in alkaline media. In ZABs, it displays a high […]
Nano-thin ‘liquid-like’ coatings may pave the way for a ‘self-cleaning’ world
Nanowerk August 17, 2023 Slippery covalently attached liquid surfaces (SCALS) with low contact angle hysteresis (CAH) and nanoscale thickness display impressive anti-adhesive properties, like lubricant-infused surfaces. Their efficacy is generally attributed to the liquid-like mobility of the constituent tethered chains. However, the precise physico-chemical properties that facilitate this mobility are unknown. An international team of researchers (Australia, Germany) quantified the chain length, grafting density, and microviscosity of a range of polydimethylsiloxane (PDMS) SCALS, elucidating the nanostructure responsible for their properties. They used three methods to produce SCALS, with characterization carried out via single-molecule force measurements, neutron reflectometry, and fluorescence correlation […]
Oil eating microbes reshape droplets to optimize biodegradation
Phys.org August 18, 2023 Certain marine bacteria can degrade small-molecule hydrocarbons, but there is still limited understanding on how this process works in biofilms. An international team of researchers (Japan, France, UK) showed that Alcanivorax borkumensis initially formed a spherical biofilm around a droplet of hexadecane, which grew and buckled. This transition was caused by an initial limited interaction with the oil by only some of the cells, followed by rapid cell growth and division that distorts the shape of the biofilm, leading to an increase in the surface area and acceleration in the rate of consumption. They identified a […]
Research group detects a quantum entanglement wave for the first time using real-space measurements
Science Daily August 23, 2023 Quantum magnets provide a powerful platform to explore complex quantum many-body phenomena. One example is triplon excitations, exotic many-body modes emerging from propagating singlet-triplet transitions. Researchers in Finland engineered a minimal quantum magnet from organic molecules and demonstrated the emergence of dispersive triplon modes in one- and two-dimensional assemblies probed with scanning tunneling microscopy and spectroscopy. According to the researchers their results provide the first demonstration of dispersive triplon excitations from a real-space measurement… read more. TECHNICAL ARTICLE
Researchers design switch-like proteins inspired by transistors
Phys.org August 23, 2023 In nature, proteins that switch between two conformations in response to environmental stimuli structurally transduce biochemical information in a manner analogous to how transistors control information flow in computing devices. Designing proteins with two distinct but fully structured conformations is a challenge for protein design as it requires sculpting an energy landscape with two distinct minima. A team of researchers in the US (University of Washington, Lawrence Berkeley National Laboratory, University of Milwaukee) described the design of “hinge” proteins that populate one designed state in the absence of ligand and a second designed state in the […]