Science Daily March 15, 2018 Researchers in China have developed a refractive index sensor based on an S-tapered fiber probe with a silver mirror on its end facet. It can sense concentration, pH and other chemical parameters. They have demonstrated that the device is nine times more sensitive than other tapered fiber refractive index sensors, requires very little sample for analysis and measurements are not affected by temperature changes. The sensor’s small size, about 1mm, means that it could potentially be used inside blood vessels. With additional development, the sensor might be used to detect specific chemicals, DNA molecules or […]
Author Archives: Hema Viswanath
Depth-sensing imaging system can peer through fog (w/video )
MIT News March 20, 2018 Using a single photon avalanche diode camera that time-tags individual detected photons, researchers at MIT have demonstrated a technique that recovers reflectance and depth of a scene obstructed by dense, dynamic, and heterogeneous fog. They developed a probabilistic computational framework to estimate the fog properties from the measurement itself, and distinguished between background photons reflected from the fog and signal photons reflected from the target. In laboratory experiments the system was able to resolve images of objects and gauge their depth at a range of 57 centimeters. The system calculates a different gamma distribution for […]
‘Frequency combs’ ID chemicals within the mid-infrared spectral region
Eurekalert March 15, 2018 Chemical compounds all carry distinctive absorption “fingerprints” within the mid-infrared spectral region of 2 to 12 microns. A team of researchers in the US (NIST Colorado, University of Colorado, NIST Maryland) leveraged robust fabrication and geometrical dispersion engineering of nanophotonic waveguides for multi-band, coherent frequency combs spanning 70 THz in the midinfrared (2.5 µm–6.2 µm). Precise waveguide fabrication provides significant spectral broadening with engineered spectra targeted at specific mid-infrared bands. They have numerous applications — from transferring time standards and improving GPS signals to precision spectroscopy. These sensors can significantly increase the detection sensitivity of tools […]
Graphene flakes for future transistors
Science Daily March 14, 2018 Researchers in Italy have demonstrated that hexagonal graphene nanoflakes with zigzag edges display quantum interference. In “Quantum interference transistors” destructive interference would be the “OFF” status. For the “ON” status, they say it is sufficient to remove the conditions for interference. They also demonstrated that magnetism emerges spontaneously at their edges, without any external intervention. This enables the creation of a spin current. The union between the phenomena of quantum interference and of magnetism would allow to obtain almost complete spin polarization, with a huge potential in the field of spintronics. These properties could be […]
The History Began from AlexNet: A Comprehensive Survey on Deep Learning Approaches
ArXiv March 3, 2018 In this report researchers at the University of Dayton present a brief survey on the development of DL approaches, including Deep Neural Network, Convolutional Neural Network, Recurrent Neural Network including Long Short-Term Memory and Gated Recurrent Units, Auto-Encoder, Deep Belief Network, Generative Adversarial Network, and Deep Reinforcement Learning. DL approaches explored and evaluated in different application domains are also included in this survey. Recently developed frameworks, SDKs, and benchmark datasets that are used for implementing and evaluating deep learning approaches are included… read more. Open Access TECHNICAL ARTICLE
How fungi grow: A movie from inside the cell
Science Daily March 15, 2018 Fungi are used to produce food or medicine and in bioengineering. Using high-performance light microscopy, an international team of researchers (Germany, Greece, Belgium, USA – University of Illinois at Urbana-Champaign, Japan) watched mold fungi as they grew in the cell. Mold fungi are hyphal fungi consisting of filamentous cells, hyphae, which may form large networks, mycelia. The hyphae of about 3 µm in thickness exclusively grow by directed extension of their tips. An important objective of biological fundamental research is to understand this growth on the molecular level, as hyphal growth plays an important role […]
How We Reverse Engineered the Cuban “Sonic Weapon” Attack
Eurekalert March 15, 2018 An international team of researchers (USA – University of Michigan, China) analysed a video sent by AP in which they heard a piercing, metallic sound. The spectral plot of the recording revealed a spectral peak near 7 kilohertz and a dozen other less-intense tones that formed a regular pattern with peaks separated by approximately 180 hertz. Based on their prior research the researchers hypothesized that intermodulation distortion can produce several by-products at other frequencies when multiple tones of different frequencies travel through air. Their math leads them to believe that intermodulation distortion is a likely culprit […]
Inspired by insects: New anti-collision technology could help create safer driverless cars
Eurekalert March 15, 2018 An international team of researchers (UK, Germany, China, Japan, Malaysia, South America) is working on a EU sponsored project called ULTRACEPT (Ultra-layered perception) with brain-inspired information processing for vehicle collision avoidance. It was inspired by the rapid reactions of insects, incorporating near-range collision detection technology, long-range hazard perception, and thermal-based collision detection tools. This will ensure that it works day and night and can quickly adapt to unexpected hazards and different conditions – for example sudden weather changes or driving in and out of tunnels… read more.
Internet of Things needs to use sound in ways computers and phones never have
Physorg March 15, 2018 Humans interpret their information about 40 milliseconds faster than visual cues. Sound alerts are only a small part of the picture. The bigger prize is enabling devices to “hear” – both other devices and other sounds in a house. This could be done relatively easily using similar technology to audio watermarking. Household devices require is a microphone, loudspeaker and relevant software… read more.
Magnon spin currents can be controlled via spin valve structure
Physorg March 15, 2018 In contrast to electrical currents magnon spin currents conduct magnetic momenta. One fundamental building block of magnon spintronics is magnon logic, by which logic operations are processed by the superposition of spin currents. An international team of researchers (Germany, Japan) reports on magnetization orientation-dependent spin current detection signals in collinear magnetic multilayers inspired by the functionality of a conventional spin valve. This yielded a spin valve-like behavior with an amplitude change of 120% in their systems… read more. Open access TECHNICAL ARTICLE