Science Daily January 18, 2020 An international team of researchers (Japan, USA – industry) presents a deep-ultraviolet semiconductor laser diode that operates under current injection at room temperature and at a very short wavelength. The laser structure was grown on the (0001) face of a single-crystal aluminum nitride substrate. The measured lasing wavelength was 271.8 nm with a pulsed duration of 50 ns and a repetition frequency of 2 kHz. A polarization-induced doping cladding layer was employed to achieve hole conductivity and injection without intentional impurity doping. Even with this undoped layer they were still able to achieve a low […]
Author Archives: Hema Viswanath
Modified plants to curb climate change
Science Daily January 21, 2020 Plants are capable of taking in nearly 123 gigatonnes through photosynthesis in a year. But humans release another ten gigatonnes of carbon dioxide into this cycle, mainly by burning fossil fuels such as crude oil and natural gas per year. By performing complex calculations an international team of researchers (Abu Dhabi, Germany) found by combining two different methods to modulate the metabolism of the plant cell it can be made to absorb five times more carbon dioxide than in the normal state. They plan to experiment with tobacco plants and thale cress which are both […]
A new stretchable battery can power wearable electronics
EurekAlert January 24, 2020 To develop a soft and stretchable battery an international team of researchers (USA – Stanford University, SLAC National Accelerator Laboratory, China, Singapore) developed a polymer that is solid and stretchable rather than gooey and potentially leaky, and carries an electric charge between the battery’s poles. In lab tests the experimental battery maintained a constant power output even when squeezed, folded and stretched to nearly twice its original length. The thumbnail-sized prototype stores roughly half as much energy, ounce for ounce, as a comparable conventional battery. The team is working to increase the battery’s energy density, build […]
Printing objects that can incorporate living organisms
MIT News January 23, 2020 Significant efforts exist to develop living/non‐living composite materials—known as biohybrids—that can support and control the functionality of biological agents. A team of researchers in the US (MIT, Dana Farber Cancer Institute) has developed a Hybrid Living Material (HLM) fabrication platform which integrates computational design, additive manufacturing, and synthetic biology to achieve replicable fabrication and control of biohybrids. The approach involves modification of multimaterial 3D‐printer descriptions to control the distribution of chemical signals within printed objects, and subsequent addition of hydrogel to object surfaces to immobilize engineered Escherichia coli and facilitate material‐driven chemical signaling. The HLM […]
Record-breaking terahertz laser beam
Phys.org January 20, 2020 An international team of researchers (Greece, Austria, Qatar, Russia, Lithuania) has experimentally demonstrated that two-color filamentation of femtosecond mid-infrared laser pulses at 3.9 μm allows one to generate ultrashort sub-cycle THz pulses with sub-milijoule energy and THz conversion efficiency of 2.36%, resulting in THz field amplitudes above 100 MV cm−1. Numerical simulations predict that the observed THz yield can be significantly upscaled by further optimizing the experimental setup. They showed that the generated THz pulses are powerful enough to induce nonlinear cross-phase modulation in electro-optic crystals. The work paves the way toward free space extreme nonlinear THz optics using […]
Researchers find a way to harness the entire spectrum of sunlight
Phys.org January 21, 2020 Researchers at the Ohio State University have shown that it is possible to collect energy from the entire visible spectrum of sunlight, including low-energy infrared, and transform it quickly and efficiently, into hydrogen. What makes it work is that the system is able to put the molecule into an excited state, where it absorbs the photon and is able to store two electrons to make hydrogen. They figured out a way make a catalyst out of one molecule of the element rhodium which means less energy is lost. The system is nearly 25 times more efficient […]
Suspending Threats in Mid-Air: Army Laser Beam Capable of Detecting Chem-Bio Warfare Agents
Global Biodefense January 14, 2020 An international team of researchers (US – US Army, Australia) used a single laser beam to develop an advanced analytical technique that can detect and characterize any type of airborne particles, naturally occurring (dust, smoke, pollen, ash, etc.) or those harmful and deliberately disseminated such as chemical and biological warfare agents. They used two small parabolic mirrors to shape up a hollow laser beam and create highly efficient trapping forces — instead of using expensive microscope objectives and complex optical setup. The approach provides contactless particle manipulation and allows a rapid and precise physio-chemical characterization. […]
Team develops an electrochemical method for extracting uranium, and potentially other metal ions, from solution
Phys.org January 23, 2020 Carboranes, molecules composed of boron, carbon and hydrogen atoms clustered together in three-dimensional shapes did not work out as rocket engine fuel as expected. According to an international team of researchers (USA – UC Santa Barbara, Israel) carboranes could hold the key to more efficient uranium ion extraction. Key to this technology is the versatility of the cluster molecule which allows for the controlled capture and release of metal ions. They devised a way to reliably and efficiently flip back and forth between open and closed carboranes, using electricity. By applying an electrical potential using an […]
Ultrafast camera takes 1 trillion frames per second of transparent objects and phenomena
Phys.org January 20, 2020 Researchers at Caltech have developed a new imaging system, phase-sensitive compressed ultrafast photography (pCUP), that combines with phase-contrast microscopy, that was designed to allow better imaging of objects that are mostly transparent such as cells. They adapted the standard phase-contrast microscopy so that it provides very fast imaging. The system consists of lossless encoding compressed ultrafast technology (LLE-CUP) which takes a single shot, capturing all the motion that occurs during the time that shot takes to complete. LLE-CUP is capable of capturing motion, such as the movement of light itself. They demonstrated the capabilities of pCUP […]
Will the future’s super batteries be made of seawater?
Science Daily January 23, 2020 For the Na-ion batteries to become an alternative to lithium-ion batteries, better electrode materials must be developed. An international team of researchers (Denmark, USA – MIT) investigated a new electrode material based on iron, manganese and phosphorus. They found that their charge–discharge transformation strains are significantly reduced by stabilization of a NazMnyFe1–yPO4 solid solution over a wide Na compositional range. This effect even leads to a complete continuous solid solution transformation covering the entire charge process, which shows that the effect of Mn substitution is a highly effective route for reducing intercalation strains even during […]