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A high-sensitivity hot-wire anemometer is proposed for use with a cobalt-doped fiber (CDF) based long-period grating (LPG) heated optically by a 1480 nm laser. The CDF-LPG absorbs laser power and generates heat inherently, thereby eliminating the need for both metal coating and mode coupling devices that are usually required in optical fiber grating anemometers. The dip wavelength of the CDF-LPG shifts with airflow velocity due to the cooling effect of the airflow. Airflow velocity is therefore measured by detecting the wavelength shift of the CDF-LPG. The measurement sensitivity is significantly enhanced by the high-temperature sensitivity of the LPG. In the experiment, high sensitivity up to -8.70 nm/(m/s) is achieved at an airflow velocity of 0.1 m/s, which is several times higher than that of fiber Bragg grating (FBG) based anemometers. The measurement range is 0-8.0 m/s. The response and recovery time are 0.4 and 0.3 seconds, respectively. The scheme of inscribing LPG on the CDF not only simplifies the production of hot-wire anemometers but also greatly improves the measurement sensitivity, making it a promising solution for high-precision airflow velocity measurement in practical applications.
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http://dx.doi.org/10.1364/OE.541684 | DOI Listing |
Mar Pollut Bull
September 2025
Tianjin Research Institute for Water Transport Engineering, Ministry of Transport, Tianjin, China.
Pneumatic booms offer distinct advantages over traditional structural barriers: not affecting the local vessel navigation and hydrological environment, enhanced mobility and maneuverability, etc. However, their oil interception performance remains insufficiently understood especially for the area-source ones. This study employs a well-validated numerical model based on the coupled VOF and DPM framework, to systematically investigate the plume evolution and oil containment efficiency of near-surface area-source bubble curtains under various aquatic scenarios.
View Article and Find Full Text PDFComput Methods Programs Biomed
November 2025
Mechanical, Manufacturing and Mechatronic Engineering, School of Engineering, RMIT University, Bundoora, Victoria 3083, Australia.
Background And Objective: During exhalation, complex geometry in the larynx generates the pharyngeal jet, where higher velocity air is directed to the rear of the airway, influencing airflow downstream in the nasal passage. This study investigates the impact of boundary condition settings on the accuracy of airflow simulations in truncated airway geometries during exhalation, focusing on the nasopharynx and nasal passage. In addition to traditional inlet profiles, we tested a new method of remapping a profile from a complete airway to a truncated airway.
View Article and Find Full Text PDFBiomimetics (Basel)
August 2025
Changchun Satellite Observation Station, National Astronomical Observatories, Chinese Academy of Sciences, Changchun 130117, China.
A miniaturised bionic electronic nose system was developed to solve the problems of expensive equipment and long response time for soil pesticide residue detection. The structure of the bionic electronic nasal cavity is designed based on the spatial structure and olfactory principle of the sturgeon nasal cavity. Through experimental study, the structure of the nasal cavity of the sturgeon was extracted and analyzed.
View Article and Find Full Text PDFPLoS One
August 2025
School of Mechanical and Mechatronic Engineering, University of Technology Sydney (UTS), Ultimo, New South Wales, Australia.
Background And Objective: Atmospheric aerosols from different industrial and natural sources enter the airways during inhalation. The smaller respirable aerosols enter the alveolar sacs and, depending on the residence time and toxicity, create severe respiratory health hazards. The physiological movement of the alveolar sacs is an important feature of breathing dynamics.
View Article and Find Full Text PDFRev Sci Instrum
August 2025
High Magnetic Field Laboratory, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China.
This study focuses on designing a high-precision laboratory for the Shenzhen superconducting soft x-ray free electron laser, addressing the stringent control requirements for temperature, humidity, and airflow that exceed conventional design methods. Using computational fluid dynamics simulation, we optimize airflow and temperature distribution to meet standards of 23 ± 0.1 °C, 37.
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