Phys.org May 29, 2024 Thermal conductivity and elastic modulus are usually positively correlated in soft materials. A team of researchers in the US (North Carolina State University, Texas A&M University) have shown anomalous correlations of thermal conductivity and elastic modulus in 2D hybrid organic–inorganic perovskites (HOIP) by engineering the molecular interactions between organic cations. By replacing conventional alkyl–alkyl and aryl–aryl type organic interactions with mixed alkyl–aryl interactions, they observed an enhancement in elastic modulus with a reduction in thermal conductivity. The anomalous dependence provided a route to engineer thermal conductivity and elastic modulus independently and a guideline to search for […]
Researchers create new type of composite material for shielding against neutron and gamma radiation
Phys.org May 24, 2024 Researchers in China created a new type of composite material for shielding against neutron and gamma radiation using micron plate Sm2O3 (samarium oxide) to reinforce boron-containing polyethylene with different specific surface areas and particle size distributions. The fillers were added to boron-containing polyethylene to create composites. The composites showed improved thermal stability, increased the melting temperature, mechanical strength, and radiation shielding properties compared to materials without the fillers. Tests revealed that the composite material could block 98.7% of neutron radiation from a 252Cf source and 72.1% of gamma radiation from a 137Cs source when the material […]
Researchers create the world’s strongest ionizing terahertz radiation
Phys.org May 28, 2024 Terahertz (THz) waves can ionize atoms and molecules when a sufficiently large number of THz photons are concentrated in time and space. An international team of researchers (South Korea, USA – University of Maryland) demonstrated the generation of ionizing, multicycle, 15-THz waves emitted from large-area lithium niobate crystals via phase-matched optical rectification of 150-terawatt laser pulses. A complete characterization of the generated THz waves in energy, pulse duration, and focal spot size showed that the field strength could reach up to 260 megavolts per centimeter. The intense THz pulses were irradiated onto various solid targets to […]
Solar storm detected in deep sea observatories
Phys.org May 16, 2024 The powerful solar storm driving the aurora borealis over global skies last weekend was also triggering the movement of compasses deep in the ocean, as revealed by Ocean Networks Canada (ONC), a University of Victoria initiative. The most significant magnetic shift moved the direction of the compass within a range of +30 to -30 degrees and was recorded at a depth of 25 meters at the Folger Passage subsea site, which is part of the ONC NEPTUNE cabled observatory off the coast of Vancouver Island. ONC’s subsea observatories on the west and east coasts of Canada […]
Strings that can vibrate forever (kind of)
Science Daily May 22, 2024 High-aspect-ratio mechanical resonators are pivotal in precision sensing. However, fabrication challenges and high computational costs have limited the length-to-thickness ratio of these devices. An international team of researchers (The Netherlands, USA – Brown University) developed nanomechanical resonators that extend centimeters in length yet retain nanometer thickness. They expanded the design to include more computationally intensive centimeter-scale design optimization. Their approach ensured high-yield realization, experimentally confirming room-temperature quality factors close to theoretical predictions. According to the researchers synergy between nanofabrication, design optimization guided by machine learning, and precision engineering opens a solid-state path to room-temperature quality […]
Technologies for the future of aerospace
Fraunhofer News May 29, 2024 At the 2024 ILA Berlin aerospace expo, to be held from June 5 to 9 the Fraunhofer-Gesellschaft will be showcasing nearly 50 exhibits from various disciplines and fields of research. They are scheduled to present urban aviation systems, satellite technology for quantum encryption, and a drone used to detect forest fires, among other solutions. They will demonstrate how cutting-edge research combines practical solutions with cost-effectiveness and climate action. Fraunhofer researchers are also active in the field of defense and security, where they will be presenting technologies for detection and defense against hypersonic weapons… read more.
Top 10 Science and Technology Inventions for the Week of May 24, 2024
01. Physicists demonstrate first metro-area quantum computer network in Boston 02. Accelerated discovery research unveils 21 novel materials for advanced organic solid-state laser technology 03. Metalens expands Its reach from light to sound 04. Next-generation sustainable electronics are doped with air 05. Researchers make a surprising discovery: Magnetism in a common material for microelectronics 06. Researchers wrestle with accuracy of AI technology used to create new drug candidates 07. Tiny displacements, giant changes in optical properties 08. Researchers develop world’s smallest quantum light detector on a silicon chip 09. Scientists create an ‘optical conveyor belt’ for quasiparticles 10. Scientists create […]
Accelerated discovery research unveils 21 novel materials for advanced organic solid-state laser technology
Phys.org May 16, 2024 To overcome the synthesis bottleneck in molecular discovery, an international team of researchers (Canada, USA – University of Illinois at Urbana-Champaign, industry, UK, Japan, Poland) developed a generalizable two-step one-pot protocol for assembling pentameric organic solid-state laser (OSL) gain materials from modular precursors, spanning over 150,000 target materials. The preparation of building blocks was distributed over the available experimental resources at four geographic locations. They found a total of 21 small-molecule emitters with improved emission gain cross sections compared with state-of-the-art OSL gain materials. The resulting data was fed into the central, machine learning–based experiment planning […]
Metalens expands Its reach from light to sound
Science Daily May 14, 2024 An important hurdle for using metalenses for manipulating waves is due to the severe hampering of the angular response originating from coma and field curvature aberrations, which result in a loss of focusing ability. Researchers in South Korea developed a blueprint by introducing the notion of a wide field-of-hearing (FOH) metalens, designed particularly for capturing and focusing sound with decreased aberrations. Employing an aberration-free planar-thin metalens that leverages perfect acoustic symmetry conversion, they experimentally realized a robust wide FOH capability of approximately 140 deg. in angular range. The metalens featured a relatively short focal length, […]
Next-generation sustainable electronics are doped with air
Science Daily May 15, 2024 Chemical doping is an important approach to manipulating charge-carrier concentration and transport in organic semiconductors (OSCs) and it ultimately enhances device performance. However, conventional doping strategies often rely on the use of highly reactive dopants which are consumed during the doping process. Achieving efficient doping with weak and/or widely accessible dopants under mild conditions remains a considerable challenge. An international team of researchers (Sweden, Italy, South Korea, UK, Italy, USA – Georgia Institute of Technology) showed that a previously undescribed concept for the photocatalytic doping of OSCs that used air as a weak oxidant (p-dopant) […]