Phys.org March 2, 2022 An international team of researcher (the Netherlands, Japan) designed, constructed, and analyzed a tunable device combining nano-particle arrays that support collective surface lattice resonances (SLRs) with liquid crystals. By leveraging the tunability of liquid crystals and the effect of the refractive index of the environment on SLRs, the optical response of the array can be controlled electrically by switching between states in the liquid crystal. The resulting rapid and reversible spectral tuning gives users a large degree of control over SLR wavelength. Because of narrow collective resonances the changes in refractive index that can be induced […]
Bacterial and Viral Bioinformatics Resource Center Website Now Available
Global Biodefense February 26, 2022 The Bacterial and Viral Bioinformatics Resource Center (BV-BRC), an initiative funded by the National Institute of Allergy and Infectious Diseases (NIAID), has launched a beta version of its website: BV-BRC Beta combining the data, technology, and extensive user communities from two long-running centers: PATRIC, the bacterial system , and IRD/ViPR, the viral systems. It is an information system designed to support the biomedical research community’s work on bacterial and viral infectious diseases via integration of vital pathogen information with rich data and analysis tools. The two resources host data on protein structure and function, clinical […]
DARPA Screening for ‘Risk’ in Researchers’ Foreign Affiliations
AIP Science Policy News February 15, 2022 The Defense Advanced Research Projects Agency is implementing a “Countering Foreign Influence Program” FAQ that involves assessing risks posed by researchers’ affiliations with foreign institutions, even for unclassified projects in fundamental research. It has implemented a review process for fundamental research projects that assesses risks posed by funding applicants’ affiliations with organizations in countries of concern. While other science agencies have likewise expanded their use of disclosure policies to identify problematic conflicts of interest and time commitment, DARPA’s policy goes further by tying the review process to specific categories of foreign entities of […]
First observation of the quantum boomerang effect
Nanowerk February 28, 2022 The boomerang effect is a disorder-induced behavior which inhibits transport of electrons turning what would otherwise be a conducting material into an insulator. An international team of researchers (USA – UC Santa Barbara, Brazil, France) reported experimental observation and characterization of this surprising quantum-mechanical phenomenon. They exposed a gas of ultracold lithium atoms to a phase-shifted pair of optical lattices to realize a “quantum kicked rotor,” a momentum-space realization of Anderson-localized matter. They observed the characteristic departure from and return to the origin that is the key signature of the boomerang effect. Detailed characterization revealed the […]
Freshwater from thin air
Science Daily February 28, 2022 Hygroscopic materials have attracted widespread attention because of their water harvesting performance. However, the introduction of many inorganic salts often leads to aggregation and leakage issues in practical use. Researchers at UT Austin have developed polyzwitterionic hydrogels as an effective Atmospheric Water Harvesting (AWH) material platform. Via anti-polyelectrolyte effects, the hygroscopic salt coordinated with polymer chains could capture moisture and enhance the swelling property, leading to a strong moisture sorption capacity. The hydrogel showed (0.62 g g−1, 120 minutes for equilibrium at 30 % relative humidity) and produced 5.87 L kg−1 freshwater per day. According to the researchers […]
Here’s what China is planning to do in space for the next five years
Phys.org February 25, 2022 China National Space Agency (CNSA) released its 10-year plan on January 28. Some main focal points include improving the sustainability of their rocket launches, improving global position system, partnering with Russia on lunar exploration, maintaining and expanding the Tiangong space station, researching the underlying technology for a Mars sample return mission, and building a global partnership to build a research station on the moon. Launching above the atmosphere is key to any global positioning system, which they plan to improve dramatically in the next five years. With some help from Russia, CNSA hopes to complete another […]
How to make a ‘computer’ out of liquid crystals
Science Daily March 2, 2022 Researchers at the University of Chicago have introduced the concept of using topological defects in active matter to perform logic operations. When an extensile active stress in a nematic liquid crystal is turned on, +1/2 defects can self-propel, in analogy to electron transport under a voltage gradient. By relying on hydrodynamic simulations of active nematics, they demonstrated that patterns of activity, when combined with surfaces imparting certain orientations, can be used to control the formation and transport of +1/2 defects. They also showed that asymmetric high- and low-activity patterns can be used to create effective […]
Lightweight nanofiber mats could battle bullets, deflect space debris
Nanowerk February 28, 2022 The weak nature of van der Waals interactions limits the CNT mats from achieving greater performance. Researchers at the University of Wisconsin have developed an efficient approach to augment the inter-fiber interactions by introducing aramid nanofiber (ANF) links between CNTs, which forms stronger and reconfigurable interfacial hydrogen bonds and π–π stacking interactions, leading to synergistic performance improvement with failure retardation. In experiments under supersonic impacts, strengthened interactions in CNT mats enhanced their specific energy absorption up to 3.6 MJ/kg which outperformed bulk Kevlar-fiber-based protective materials. By modifying the interfacial interactions in the mats by adding Kevlar […]
Live wire: New research on nanoelectronics
Phys.org February 25, 2022 Researchers at Arizona State University have shown that a protein poised between a pair of electrodes could act as an efficient conductor of electrons. Proteins may have better conductance properties than similar nanowires composed of DNA. The expanded alphabet of 20 amino acids used to construct them offers an enhanced toolkit for nano architects when compared with just four nucleotides making up DNA. The researchers used protein segments in four nanometer increments, ranging from 4-20 nanometers in length. When the protein nanowires exceeded six nanometers in length, their conductance outperformed molecular nanowires. The data showed that […]
Metasurface-based antenna turns ambient radio waves into electric power
Phys.org February 28, 2022 Researchers at the South Florida University have demonstrated a high-efficiency RF energy harvesting device based on a metamaterial perfect absorber (MPA). With the embedded Schottky diodes, the MPA-based rectenna converts captured RF waves to DC power. The Fabry-Perot (FP) cavity resonance of the MPA greatly improved the amount of energy captured. The FP resonance exhibited a high Q-factor and significantly increased the voltage across the Schottky diodes, which improved the rectification efficiency, particularly at low intensity. This led to a factor of 16 improvement of RF-DC conversion efficiency at ambient intensity level. According to the researchers […]