In this work, a flush ultrasonic probe has been developed for the measurement of the velocity and the angle of attack (AOA) of an aircraft. The probe is made of one emitting transducer located at the center of a rotating stage and several receiving transducers located downstream, all transducers radiating in a normal direction perpendicular to the airflow. The determination of speed and AOA are deduced from the time of flight measurement of an ultrasonic wave between the emitter and the receivers propagating in the boundary layer. Particular attention was paid to the instrumentation as well as to the signal processing to enhance the ultrasound transmission and reception and to increase the signal-to-noise ratio. Results are reported for airflow velocities up to 127 m/s (460 km/h) both as a function of the emitter-receiver distance and as a function of the wind incidence angle. These experimental results are compared to simulations that estimate the time of flight between a source and a receiver. It is shown that ultrasonic waves propagate in the boundary layer and that the simulation code can predict the time of flight as a function of the distance and the angle.
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http://dx.doi.org/10.1016/j.ultras.2023.106969 | DOI Listing |
ACS EST Air
January 2025
Department of Chemistry, University of Colorado Boulder, Boulder, Colorado 80309, United States.
Wildfires at the wildland-urban interface (WUI) have been increasing in frequency over recent decades due to increased human development and shifting climatic patterns. The work presented here focuses on the impacts of a WUI fire on indoor air using field measurements of volatile organic compounds (VOCs) by Proton-Transfer-Reaction Time-of-Flight Mass Spectrometry (PTR-TOF-MS). We found a slow decrease in VOC mixing ratios over the course of roughly 5 weeks starting 10 days after the fire, and those levels decreased to ∼20% of the initial indoor value on average.
View Article and Find Full Text PDFSci Rep
January 2025
Grupo de Ecología de Poblaciones de Insectos, Instituto de Investigaciones Forestales y Agropecuarias Bariloche (IFAB) (CONICET - INTA), Modesta Victoria N°4450, San Carlos de Bariloche, Río Negro, 8400, Argentina.
During the mating season, reproductive individuals of numerous insect species gather in rendezvous areas, which increases mating opportunities. Male hymenopterans often have to move considerable distances during a particular season, searching or waiting for receptive females. Such behavior is likely driven by a complex combination of individual and species-specific traits, environmental influence, and landscape cues.
View Article and Find Full Text PDFNature
January 2025
Key Laboratory of Coastal Environment and Resources of Zhejiang Province, School of Engineering, Westlake University, Hangzhou, China.
The amount of methane released to the atmosphere from the Nord Stream subsea pipeline leaks remains uncertain, as reflected in a wide range of estimates. A lack of information regarding the temporal variation in atmospheric emissions has made it challenging to reconcile pipeline volumetric (bottom-up) estimates with measurement-based (top-down) estimates. Here we simulate pipeline rupture emission rates and integrate these with methane dissolution and sea-surface outgassing estimates to model the evolution of atmospheric emissions from the leaks.
View Article and Find Full Text PDFFEMS Microbiol Lett
January 2025
Department of Microbiology, Sapporo Medical University School of Medicine, Sapporo, Hokkaido 060-8556, Japan.
Latilactobacillus curvatus, found in various fermented foods, is a promising probiotic with unique health benefits. Lipoteichoic acid (LTA) is a characteristic amphiphilic surface polymer of gram-positive bacteria and exhibits immunomodulatory activities. Despite the structural diversity of LTA among different bacterial species and strains, no information is available on the chemical structure of LTA in L.
View Article and Find Full Text PDFNeuroinformatics
January 2025
Department of Clinical Medicine, UiT the Arctic University of Norway, Tromsø, Norway.
Intracranial atherosclerotic stenosis (ICAS) and intracranial aneurysms are prevalent conditions in the cerebrovascular system. ICAS causes a narrowing of the arterial lumen, thereby restricting blood flow, while aneurysms involve the ballooning of blood vessels. Both conditions can lead to severe outcomes, such as stroke or vessel rupture, which can be fatal.
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