Pollutant emissions from aircraft operations contribute to the degradation of air quality in and around airports. Meeting the ICAO's environmental certification standards regarding both gaseous and particulate aircraft engine emissions is one of the main challenges for air-transportation development over the coming years. To increase the accuracy of airport air pollution monitoring and prediction, advanced decision-making tools need to be developed. In this context, the present study aimed at demonstrating the modeling capabilities of an innovative methodology that accounts for the microscale evolution of aircraft emissions, both spatially and temporally. For this purpose, 3D high-resolution CFD simulations were carried out in the CAEPport configuration (medium-size mock airport) as defined by the Committee on Aviation Environmental Protection (CAEP/8) for local air-quality assessment. The modeled domain extends up to 8 km around the airport. A spatial resolution down to 1 m was used around buildings to refine the prediction of pollutant-emission concentrations. The model accounts for ambient meteorological conditions along with the background chemical composition. NO emissions from main engines and auxiliary power units (APUs) were individually tracked along LTO trajectories with a time resolution down to 1 s. The impact of atmospheric stability was investigated in three cases, i.e., stable, neutral, and unstable. The results show NO dominating in apron areas due to the low power setting of main engines along APU contribution during extended parking. Conversely, a domination of NO emissions was observed at the runway threshold due to the high power setting of the main engines. Stable atmospheric conditions promoted higher NO and NO concentrations as compared to both neutral and unstable cases. The use of APUs contributed to higher concentrations of both NO and NO emissions and especially of NO in terminal areas.
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http://dx.doi.org/10.1007/s11270-022-05889-y | DOI Listing |
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Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Korea.
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View Article and Find Full Text PDFExp Brain Res
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Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, Canada.
Tachistoscopic studies have established a right field advantage for the perception of visually presented words, which has been interpreted as reflecting a left hemispheric specialization. However, it is not clear whether this is driven by the linguistic task of word processing, or also occurs when processing properties such as the style and regularity of text. We had 23 subjects perform a tachistoscopic study while they viewed five-letter words in either computer font or handwriting.
View Article and Find Full Text PDFAnal Methods
November 2017
Agricultural and Biological Engineering Department, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, USA.
Nitric oxide (NO) is an important signaling molecule that is involved in stress response, homeostasis, host defense, and cell development. In most cells, NO levels are in the femtomolar to micromolar range, with extracellular concentrations being much lower. Thus, real time measurement of spatiotemporal NO dynamics near the surface of living cells/tissues is a major challenge.
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View Article and Find Full Text PDFEnviron Geochem Health
January 2025
College of Resources and Environmental Engineering, Guizhou University, Guiyang, 550025, China.
The superposition of heavy metals (HMs) from multiple anthropogenic sources in geochemical anomaly areas makes it difficult to discriminate prime sources in atmospheric HMs. This study utilized a combination of microscopic features, positive matrix factorisation, and Pb isotope fingerprints to trace the main sources of HMs bound to total suspended particulates (TSP) at a pollution site (Msoshui: MS) and control site (Lushan: LS) in northwestern Guizhou. The results reveal that the concentrations of Cd, Pb, Cr, As, Cu, Ni, and Zn in the TSP of LS are 3.
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