Results 41 to 50 of about 123,753 (301)

Smart Face Masks as Wearable Respiratory Sensors: A Review of Sensor Technologies, Materials, and Future Directions

open access: yesAdvanced Healthcare Materials, EarlyView.
This review highlights recent advances in smart face masks that actively monitor breathing. By integrating humidity, gas, temperature, pressure, strain, and triboelectric sensors, these masks track key respiratory parameters in real time. The article summarizes sensor mechanisms, compares performance across studies, and discusses challenges and future ...
Negin Faramarzi   +7 more
wiley   +1 more source

First results of optical meteor and meteor trail irregularity from simultaneous Sanya radar and video observations

open access: yesEarth and Planetary Physics, 2018
Meteoroids entering the Earth's atmosphere can create meteor trail irregularity seriously disturbing the background ionosphere. Although numerous observations of meteor trail irregularities were performed with VHF/UHF coherent scatter radars in the past,
GuoZhu Li   +6 more
doaj   +1 more source

Metamaterial Antennas Enhance MRI of the Eye and Occipital Brain

open access: yesAdvanced Materials, EarlyView.
A radiofrequency antenna platform comprising planar and bend configurations is developed, incorporating structurally integrated epsilon‐negative metamaterial unit cells to enhance MRI. These antennas enable high‐resolution in vivo human MRI of the eye, orbit, and occipital brain. Comprehensive validation, including simulations, phantom experiments, SAR,
Nandita Saha   +14 more
wiley   +1 more source

Nanosecond Miniature Transmitters for Pulsed Optical Radars [PDF]

open access: yes, 2017
The-state-of-the-art in long-distance near-infrared optical radars is utilization the laser-diode-based miniature pulsed transmitters producing optical pulses of 3–10 ns in duration and peak power typically below 40 W. The bandwidth of the receiving channel nowadays exceeds 300 MHz, and thus the duration of the optical pulses exceeding 3 ns is a ...
Filimonov, A. V. (Alexey V.)   +5 more
openaire   +2 more sources

Servomechanism for Doppler shift compensation in optical correlator for synthetic aperture radar [PDF]

open access: yes, 1980
A method and apparatus for correcting Doppler shifts in synthetic aperture radar data is described. An optical correlator for synthetic aperture radar data has a means for directing a laser beam at a signal film having radar return pulse intensity ...
Bicknell, T. J., Constaninides, N. J.
core   +1 more source

Multifunctional Bio‐Based Packaging for Perishable Foods: Structural Design, Scalable Fabrication, and Versatile Applications

open access: yesAdvanced Materials, EarlyView.
An overview of design principles and scalable fabrication strategies for multifunctional bio‐based packaging. Radiative cooling films, modified‐atmosphere films/membranes, active antimicrobial/antioxidant platforms, intelligent optical/electrochemical labels, and superhydrophobic surfaces are co‐engineered from material chemistry to mesoscale structure
Lei Zhang   +6 more
wiley   +1 more source

All-optical bandwidth-tailorable radar

open access: yes, 2015
17 pages, 5 ...
Zou, Weiwen   +5 more
openaire   +2 more sources

New‐Era Polymer Thermoelectrics: Material Innovations, Doping Frontiers, Decoupling Strategies, and Unconventional Applications

open access: yesAdvanced Materials, EarlyView.
The field of polymer thermoelectrics is entering a new era, featuring breakthroughs in addressing the conventional performance disparity between p‐type and n‐type polymers, pioneering doping frontiers, and sophisticated decoupling strategies. This review explores innovations in molecular design and superior stabilities, bridging the gap from ...
Suhao Wang
wiley   +1 more source

Estimating Proportion of Vegetation Cover at the Vicinity of Archaeological Sites Using Sentinel-1 and -2 Data, Supplemented by Crowdsourced OpenStreetMap Geodata

open access: yesApplied Sciences, 2020
Monitoring vegetation cover is an essential parameter for assessing various natural and anthropogenic hazards that occur at the vicinity of archaeological sites and landscapes.
Athos Agapiou
doaj   +1 more source

Frequency-phase modulated thermal wave radar : stepping beyond state-of-the-art infrared thermography [PDF]

open access: yes, 2019
Thermal wave radar is a state-of-the-art non-destructive testing method inspired by radio wave radar systems. The underlying principle of the technique is the application of a modulated excitation waveform by which the total energy of the response signal
Hedayatrasa, Saeid   +4 more
core  

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