Phys.org November 29, 2020 The Hayabusa2 spacecraft left the asteroid Ryugu, about 180 million miles from Earth, a year ago and is expected to reach Earth and drop a the pan-shaped capsule with a diameter of 15 inches containing the precious samples in southern Australia onto a remote, sparsely populated area on Dec. 6. It will drop the capsule containing the samples from 136,700 miles away in space, a big challenge requiring precision control. The capsule, protected by a heat shield, will turn into a fireball during re-entry in the atmosphere at 125 miles above ground. At about 6 miles […]
Mapping quantum structures with light to unlock their capabilities
Nanowerk December 4, 2020 All-optical band-structure reconstruction could directly connect electronic structure with the coveted quantum phenomena if strong light waves transported localized electrons within preselected bands. An international team of researchers (USA – University of Michigan, Germany) has shown that harmonic sideband (HSB) generation in monolayer tungsten diselenide creates distinct electronic interference combs in momentum space. Locating these momentum combs in spectroscopy enables super-resolution tomography of key band-structure details in situ. They experimentally tuned the optical-driver frequency by a full octave and showed that the predicted super-resolution manifests in a critical intensity and frequency dependence of HSBs. The concept […]
Molecules convert visible light into ultraviolet light with record efficiency
EurekAlert December 4, 2020 To directly convert visible light with wavelengths longer than 400 nm into higher-energy ultraviolet light researchers in Japan focused on triplet-triplet annihilation where triplets are formed on molecules following absorption of visible light. These “donor” molecules then give their triplets to “acceptor” molecules that can combine two triplets to create a single, higher-energy state that is released as ultraviolet light. They developed an acceptor molecule TIPS-naphthalene that has a high triplet-triplet-annihilation efficiency and a low enough triplet energy to easily accept triplets from a molecule called Ir(C6)2(acac). The combination of TIPS-naphthalene and Ir(C6)2(acac) successfully achieved the […]
New cyberattack can trick scientists into making toxins or viruses — Ben-Gurion University researchers
EurekAlert November 30, 2020 According to the researchers in Israel a malware could easily replace a short sub-string of the DNA on a bioengineer’s computer so that they unintentionally create a toxin producing sequence. To regulate both intentional and unintentional generation of dangerous substances, most synthetic gene providers screen DNA orders which is currently the most effective line of defense against such attacks. Unfortunately, the screening guidelines have not been adapted to reflect recent developments in synthetic biology and cyberwarfare. Screening protocols can be circumvented using a generic obfuscation procedure which makes it difficult for the screening software to detect […]
Oddly satisfying metamaterials store energy in their skin
Science Daily December 2, 2020 Metamaterials’ properties are controlled through structural design at the mesoscale, thus broadening the design space beyond the limits of traditional materials. An international team of researchers (USA – Purdue University, Switzerland) experimented with a family of mechanical metamaterials consisting of soft sheets and patterned array of reconfigurable bistable domes. The domes can be reversibly inverted at the local scale to generate programmable multistable shapes and tunable mechanical responses at the global scale. By 3D printing a robotic gripper with energy‐storing skin and a structure that can memorize and compute spatially‐distributed mechanical signals, they have shown […]
Once in a lifetime floods to become regular occurrences by end of century
Science Daily December 2, 2020 Based on the anticipated greenhouse gas concentration by the end of the 21st century a team of researchers in the US (Stevens Institute of Technology, Princeton University) conducted high resolution simulations for different scenarios to find the probability of different flood levels being reached, assuming emissions remain at a high level. They studied how sea level rise and hurricane climatology change would impact the area in the future due to storm surge and wave hazards. They found that the historical 100-year flood level would become a nine-year flood level by mid-century (2030-2050) and a one-year […]
Physicists Observe Trippy ‘Vortex Rings’ in a Magnetic Material For The First Time
Science Alert December 1, 2020 Magnetic ring vortices were predicted over 20 years ago in 1998. An international team of researchers (UK, Switzerland, Ukraine, Russia) have found vortex rings inside a tiny pillar made of the magnetic material gadolinium-cobalt intermetallic compound GdCo2. They developed an X-ray nanotomography technique to image the three-dimensional magnetization structure inside a GdCo2 bulk magnet. The vortices were paired with their topological counterparts, antivortices. They also found closed magnetic loops present in vortex-antivortex pairs. After computationally analysing these structures in the context of magnetic vorticity they figured out these were doughnut-shaped ring vortices, intersected by magnetization […]
Quantum nanodiamonds may help detect disease earlier
Science Daily November 25, 2020 Researchers in the UK investigated fluorescent nanodiamonds as an ultrasensitive label for in vitro diagnostics, using a microwave field to modulate emission intensity and frequency-domain analysis to separate the signal from background autofluorescence, which typically limits sensitivity. Focusing on the widely used, low-cost lateral flow format as an exemplar, they achieved a detection limit of 8.2 × 10−19 molar for a biotin–avidin model, 105 times more sensitive than that obtained using gold nanoparticles. Single-copy detection of HIV-1 RNA can be achieved with the addition of a 10-minute isothermal amplification step. This ultrasensitive quantum diagnostics platform […]
Researchers fabricate co-doped aluminosilicate fiber with high laser stability for multi-kW level laser
Phys.org November 27, 2020 Fiber fabrication technology have led to an exponential increase in the output power of CW fiber lasers. However, with further scaling the output power, photodarkening (PD) is the critical limit factor for long-term laser reliability under multi kW level output power. Researchers in China demonstrated stable performance in fiber fabricated the Yb/Ce codoped aluminosilicate laser. The molar ratio of Ce/Yb was designed and optimized to be 0.58 for low background loss, effective photodarkening suppression, and no additional thermal load. The background loss of was 4.7 dB/km and its photodarkening loss at equilibrium was as low as 3.9 […]
Self-repairing gelatin-based film could be a smart move for electronics
Phys.org December 2, 2020 Self-repairing films have been developed, but most only work a single time, and some are made with potentially harmful agents that curtail their use in biomedical applications. Researchers in Taiwan mixed gelatin and glucose to create a flexible film that they sandwiched between conductive material to simulate an electronic device. After bending the simulated electronic device, the team saw breaks in the gelatin-glucose film disappear within three hours at room temperature and within 10 minutes when warmed to 140 F. Gelatin without glucose did not self-repair under the same conditions. The glucose-based gelatin also transferred an […]