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The meander-line coil electromagnetic acoustic transducer (EMAT) is widely used in the field of ultrasonic nondestructive testing due to its convenience to generate specific mode of guided waves. Some design methods of the meander-coil EMATs are developed in the frequency-wavenumber domain while others in the time-space domain. In this paper, a unified theoretical framework is developed by proposing an analytical model from the system perspective. Signal transfers between different physical fields in EMAT excitation, wave propagation and EMAT reception are represented as linear time-space-invariant systems. Taking the Rayleigh wave EMAT detection as an example, the analytical model for the transfer functions of these systems is established. The analytical model is experimentally verified by different Rayleigh wave detection techniques: the conventional EMAT, the spatial pulse compression (SPC) EMAT, temporal-spatial pulse compression (TSPC) EMAT and detection cases employing the same receiving EMAT. From the system perspective, the received signal of EMAT is interpreted as the response of the filter system to the input signal. It is found that the meander-coil EMAT can be regarded as the frequency domain expression during the detection. And the frequency domain expression plays different roles in different techniques.
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http://dx.doi.org/10.1016/j.ultras.2024.107493 | DOI Listing |
Environ Sci Pollut Res Int
September 2025
Faculdade de Engenharia da Universidade do Porto, INESC TEC, Porto, Portugal.
Food waste generated throughout the food supply chain raises several environmental, social, and economic issues. Quantitative methods can aid in managing food waste by describing current contexts, predicting future scenarios, and improving related operations. However, a literature review on the use of quantitative methods, specifically the descriptive, predictive, and prescriptive dimensions, to assess and prevent food waste is lacking.
View Article and Find Full Text PDFEnviron Res
September 2025
Thrust of Sustainable Energy and Environment, Function Hub, The Hong Kong University of Science and Technology (Guangzhou), Guangzhou 510000, China. Electronic address:
China's aluminum-products industry, a large-scale consumer of industrial paints, is a potentially significant source of full-volatility organic compounds (F-VOCs). However, the emission characteristics of F-VOCs, including VOCs, intermediate-, semi-, and low-volatility organic compounds (I/S/LVOCs), and their role in ozone formation potentials (OFP), and secondary organic aerosol formation potentials (SOAP) remain unclear. In this study, we collected in-field samples from three industrial paints (solvent-based, water-based and powder paints) at spraying and drying processes, and treatment devices to analyze the emission characteristics of F-VOCs, OFP, SOAP.
View Article and Find Full Text PDFSci Total Environ
September 2025
University Hohenheim, Department of Process Analytics and Cereal Science, Stuttgart, 70599, Germany.
Per- and polyfluoroalkyl substances (PFAS) are persistent organic pollutants with increasing prevalence in agricultural soils, primarily introduced through biosolid application, wastewater irrigation, and atmospheric deposition. This review provides a meta-analysis of terminologies across 145 peer-reviewed studies, identifying inconsistency in the classification of PFAS subgroups-such as "long-chain vs. short-chain," "precursors," and "emerging PFAS"-which hinders regulatory harmonization and model calibration.
View Article and Find Full Text PDFJ Environ Manage
September 2025
University of Maryland Center for Environmental Science, Annapolis, MD, USA.
River water quality degradation is a prevailing problem in coastal China with intensifying human-nature interaction. However, the spatial and temporal dynamics of water quality and their drivers remain poorly understood. In this study, we developed an analytical framework integrating self-organizing mapping (SOM) with partial least squares structural equation models (PLS-SEMs) to analyze the patterns and drivers of river water quality at 49 stations from 2021 to 2023 in Fujian Province, a coastal region in southeastern China.
View Article and Find Full Text PDFFood Chem
September 2025
Group of Chemical Analysis and Chemometrics, Department of Chemistry, Federal University of Paraná, P.O. Box: 19032, Curitiba, PR 81531-980, Brazil. Electronic address:
Yerba mate, a key crop in South America, is prized for its pleasant taste and high organoleptic quality, often linked to lower branch content. To quantify branch content and authenticate high-quality samples (less than 30 % m/m branch content), a Chemometrics-assisted Color Histogram-based Analytical System (CACHAS) was employed. Using Hue-Saturation-Value (HSV) histograms, Partial Least Squares (PLS) demonstrated excellent predictive performance, achieving a root mean square error (RMSEP) of 4.
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