Nanowerk May 25, 2021 Flexible metamaterials often harness zero-energy deformation modes. To date they have a single property, such as a single shape change, or are pluripotent. An international team of researchers (the Netherlands, Switzerland) has introduced a class of oligomodal metamaterials that encode a few distinct properties that can be selectively controlled under uniaxial compression. They demonstrated this concept by introducing a combinatorial design space containing various families of metamaterials. They included monomodal (with a single zero-energy deformation mode); oligomodal (with a constant number of zero-energy deformation modes); and plurimodal (with many zero-energy deformation modes), whose number increases with system […]
Quantum electronics: ‘Bite’ defects in bottom-up graphene nanoribbons
Science Daily May 25, 2021 Researchers in Switzerland have shown the nature of the structural disorder in bottom-up zigzag graphene nanoribbons along with its effect on the magnetism and electronic transport based on scanning probe microscopies and first-principles calculations. They found that edge-missing m-xylene units emerging during the cyclodehydrogenation step of the on-surface synthesis are the most common point defects. These “bite” defects act as spin-1 paramagnetic centers, severely disrupting the conductance spectrum around the band extrema, and give rise to spin-polarized charge transport. They also showed that the electronic conductance across graphene nanoribbons is more sensitive to “bite” defects […]
Quantum sensing: Odd angles make for strong spin-spin coupling
Science Daily May 25, 2021 Exotic quantum vacuum phenomena are predicted in cavity quantum electrodynamics systems with ultra-strong light-matter interactions. However, such predictions have not been realized because antiresonant interactions are typically negligible compared to resonant interactions in light-matter systems. An international team of researchers (USA – Rice University, Japan, Germany, China) reports an unusual, ultra-strongly coupled matter-matter system of magnons that is analytically described by a unique Hamiltonian in which the relative importance of resonant and antiresonant interactions can be easily tuned and the latter can be made vastly dominant. They found a regime where vacuum Bloch-Siegert shifts, the […]
Researchers examine record-shattering 2020 trans-Atlantic dust storm
Phys.org May 26, 2021 For two weeks in June 2020, a massive dust plume from Saharan Africa crept westward across the Atlantic, blanketing the Caribbean and Gulf Coast states in the U.S. Researchers at the University of Kansas used satellite datasets to reconstruct the patterns that transported the dust from Africa to the Americas. According to the researchers the extreme trans-Atlantic dust event is associated with both enhanced dust emissions over western North Africa and atmospheric circulation extremes that favor long-range dust transport. An exceptionally strong African easterly jet and associated wave activities export African dust across the Atlantic toward […]
The ‘Replication Crisis’ Could Be Worse Than We Thought, New Analysis Reveals
Science Alert May 25, 2021 A team of researchers at UC San Diego used publicly available data to show that published papers in top psychology, economics, and general interest journals that fail to replicate are cited more than those that replicate. This difference in citation does not change after the publication of the failure to replicate. Only 12% of post replication citations of nonreplicable findings acknowledge the replication failure. Existing evidence also shows that experts predict well which papers will be replicated. Given this prediction, why are nonreplicable papers accepted for publication in the first place? A possible answer is […]
Slender robotic finger senses buried items
MIT News May 26, 2021 Technologies that sense the subterranean from above provide only a hazy view of submerged objects. Researchers at MIT have designed Digger Finger to meet the challenge of identifying buried objects. The Digger Finger is a slender cylinder with a beveled tip and uses a combination of blue LEDs and colored fluorescent paint. Its tactile sensing membrane is about 2 square centimeters. They ran its vibrating motor at different operating voltages, which changes the amplitude and frequency of the vibrations. They found that rapid vibrations helped “fluidize” the media, clearing jams and allowing for deeper burrowing. […]
Solar storms are back, threatening life as we know it on Earth
Phys.org May 24, 2021 The danger of solar storms is not hypothetical. In 2017, a solar storm caused ham radios to turn to static, in 2015 solar storms knocked out global positioning systems in the U.S. Northeast, a particular concern as self-driving cars become a reality. According to a 2017 paper in the journal of the American Geophysical Union predicted blackouts caused by severe space weather could strike as much as 66% of the U.S. population, with economic losses reaching a potential $41.5 billion a day. To shield vulnerable parts of the planet’s infrastructure from the effects of solar storms […]
Ultrafast, on-chip PCR could speed diagnosis during pandemics
Phys.org May 26, 2021 Researchers in South Korea have developed a plasmofluidic PCR chip comprising glass nanopillar arrays with Au nanoislands and gas-permeable microfluidic channels, which contain reaction microchamber arrays, a precharged vacuum cell, and a vapor barrier. The on-chip configuration allows both spontaneous sample loading and microbubble-free PCR reaction during which the plasmonic nanopillar arrays result in ultrafast photothermal cycling. After rapid sample loading, two-step PCR results for 40 cycles show rapid amplification in 264 s for lambda-DNA, and 306 s for plasmids expressing SARS-CoV-2 envelope protein. In addition, the in situ cyclic real-time quantification of amplicons clearly demonstrates […]
Understanding of invisible but mighty particles in Earth’s radiation belts
Science Daily May 26, 2021 In recent years, however, a growing body of experimental evidence has shown that EMIC waves can cause the scattering loss of electrons down to sub-MeV energies. Using measurements of trapped electron flux from the GPS satellite constellation, an international team of researchers (New Zealand, UK, USA – Los Alamos National Laboratory) investigated the ability of EMIC waves to cause significant depletions of radiation belt electron populations. They presented statistical evidence demonstrating global decreases in sub-MeV trapped electron flux in response to EMIC wave activity. Although they found that electron losses extend down to sub-MeV energies, […]
Top 10 Science and Technology Inventions for the Week of May 21, 2021
01. Harvesting light like nature does 02. Engineers harvest WiFi signals to power small electronics 03. New material could harvest water all day long 04. Nuclear terrorism could be intercepted by neutron-gamma detector that pinpoints source 05. Researchers shed light on the evolution of extremist groups 06. Using micro-sized cut metal wires, team forges path to new uses for terahertz waves 07. Future sparkles for diamond-based quantum technology 08. Rechargeable cement-based batteries 09. How plants leave behind their parents’ genomic baggage 10. Nanofiber filter captures almost 100% of coronavirus aerosols And others… Climate change threatens one-third of global food production COVID-19 testing […]