Phys.org August 17, 2024 Seismic energy arriving before the compressional (P) wave passing through the core (PKP), called PKP precursors, have been detected for decades, but the origin of those arrivals is ambiguous. The largest amplitude arrivals are linked to scattering at small-scale lowermost mantle structure, but because these arrivals traverse both source and receiver sides of the mantle, it is unknown which side of the path the energy is scattered from. To address this ambiguity, an international team of researchers (USA – University of Utah, University of Arizona, UK) applied a new seismic array method to analyze PKP waveforms […]
MIT engineers design tiny batteries for powering cell-sized robots
MIT News August 15, 2024 The use of wet chemistry in battery technologies limits their potential to be scaled down beyond millimeters in size. A team of researchers in the US (MIT, University of Pennsylvania, University of Michigan) photolithographically patterned a microscale zinc/platinum/SU-8 system to generate the highest energy density microbattery at the picoliter scale. The device scavenges ambient or solution-dissolved oxygen for a zinc oxidation reaction, achieving an energy density ranging from 760 to 1070 watt-hours per liter at scales below 100 micrometers lateral and 2 micrometers thickness in size. The processes allow 10,000 devices per wafer to be […]
More academic freedom leads to more innovation, reports study
Phys.org August 21, 2024 We know little about how academic freedom relates to indicators of societal progress, such as innovation. An international team of researchers (USA – Indiana University, Luxembourg Italy, Germany) addressed this research gap by empirically assessing the impact of academic freedom on the quantity (patent applications) and quality (patent citations) of innovation output using a comprehensive sample of 157 countries over the 1900–2015 period. They found that improving academic freedom by one standard deviation increases patent applications by 41% and forward citations by 29%. The results were robust across a range of different specifications. Their findings constituted […]
Morphable materials: Researchers coax nanoparticles to reconfigure themselves
Phys.org August 19, 2024 Nanoparticle self-assembly offers a scalable and versatile means to fabricate next-generation materials. The prevalence of metastable and nonequilibrium states during the assembly process makes the final structure and function directly dependent upon formation pathways. A team of researchers in the US (Indiana University, University of Michigan) used liquid-cell transmission electron microscopy to image complete self-assembly processes of gold nanocubes, a model shape-anisotropic nanocolloidal system, into distinct superlattices. Theoretical analysis and molecular dynamics simulations indicated that the electrostatic screening of the medium dictated self-assembly pathways by its effects on the interactions between nanocubes. They leveraged this understanding […]
New software tool aims to reduce reliance on animal testing
Phys.org August 20, 2024 The exponential growth of data is challenging to analyze and extract relevant and useful data. In chemistry there is a demand for tools that can visualize molecular datasets in a convenient graphical way. Researchers in Austria proposed a new, ready-to-use, multi-tool, and open-source framework for visualizing and navigating chemical space. The framework adhered to the low-code/no-code (LCNC) paradigm, provided a KNIME (KoNstanz Information MinEr) node, a web-based tool, and a Python package, making it accessible to a broad cheminformatics community. They demonstrated how this framework could be adapted for the visualization of chemical space and visual […]
Printed electronics material can store 1,000 times more charge than current forms
Phys.org August 19, 2024 Making the Internet of Things a reality will require the type of circuitry and advanced operations that are only possible with electronics that can function in both positive and negative voltage modes. Researchers in Canada developed a new material zwitterion composed of an imidazolium tethered to an anionic sulfonyl(trifluoromethane sulfonyl)imide group as an alternative dielectric material to traditional ionic liquids. The zwitterion not only melted below 100 °C but also proved to be nonhygroscopic. By blending this compound with poly(methyl methacrylate) over a range of concentrations and thicknesses, they made high-capacitance organic dielectric materials. Experiments suggested […]
Researchers observe ‘locked’ electron pairs in a superconductor cuprate
Phys.org August 15, 2024 Copper oxide materials can be made superconducting by doping the parent compound with either electrons or holes. Hole-doped cuprates typically have higher transition temperatures and have been studied more extensively. An international team of researchers (SLAC National Accelerator Laboratory, Yale University, UC Berkeley, Sweden) observed an unusual energy gap in electron-doped cuprate Nd2-xCexCuO4 high above the temperature of the superconducting transition. After considering all the known ordering tendencies in tandem with the phase diagram, they hypothesized that the normal-state gap in the underdoped n-type cuprates originated from Cooper pairing. According to the researchers the high temperature […]
Scientists investigate triggers of explosive volcanic eruptions in lab simulation study
Phys.org August 19, 2024 Transitions in eruptive style during volcanic eruptions strongly depend on how easily gas and magma decouple during ascent. Stronger gas-melt coupling favors highly explosive eruptions, whereas weaker coupling promotes lava fountaining and lava flows. The mechanisms producing these transitions are still poorly understood because of a lack of direct observations of bubble dynamics under natural magmatic conditions. An international team of researchers (UK, Italy, France) combined x-ray radiography with a high-pressure/high-temperature apparatus to observe and quantify in real-time bubble growth and coalescence in basaltic magmas from 100 megapascals to surface. For low-viscosity magmas, bubbles coalesced and […]
Smart fabrics detect and repel pathogens to prevent hospital infections
Nanowerk August 20, 2024 Healthcare textiles serve as key reservoirs for pathogen proliferation. Researchers in Canada developed a new class of Smart Fabrics (SF) with integrated “Repel, Kill, and Detect” functionalities, which they achieved through a blend of hierarchically structured microparticles, modified nanoparticles, and an acidity-responsive sensor. It showed good resilience against aerosol and droplet-based pathogen transmission, showed a reduction exceeding 99.90% compared to uncoated fabrics across various drug-resistant bacteria. Experiments involving bodily fluids from healthy and infected individuals revealed a significant reduction of 99.88% and 99.79% in clinical urine and feces samples compared to uncoated fabrics. According to the […]
Specialized materials could passively control the internal temperature of space habitats
Phys.org August 19, 2024 Researchers in Spain explored the design of a space habitat thermally controlled using phase change materials (PCMs) to maintain a suitable, habitable temperature inside the habitat by isolating it from the external solar radiation. They studied the system numerically considering only diffusive heat transport scenario with practical application to microgravity or reduced gravity environments. The system dynamics were explored for a wide range of governing parameters, including the length of the PCM cell L, the thermo-optical properties at the external boundary of the habitat wall exposed to solar radiation, the eclipse fraction of the solar cycle, […]