This study numerically investigates the influence of initial water content and rain intensities on the preferential migration of two fluorescent tracers, Acid Yellow 7 (AY7) and Sulforhodamine B (SB), through variably-saturated fractured clayey till. The simulations are based on the numerical model HydroGeoSphere, which solves 3D variably-saturated flow and solute transport in discretely-fractured porous media. Using detailed knowledge of the matrix, fracture, and biopore properties, the numerical model is calibrated and validated against experimental high-resolution tracer images/data collected under dry and wet soil conditions and for three different rain events. The model could reproduce reasonably well the observed preferential migration of AY7 and SB through the fractured till, although it did not capture the exact depth of migration and the negligible impact of the dead-end biopores in a near-saturated matrix. A sensitivity analysis suggests fast flow mechanisms and dynamic surface coating in the biopores, and the presence of a plough pan in the till.
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http://dx.doi.org/10.1016/j.jconhyd.2008.09.001 | DOI Listing |
Environ Technol
December 2024
Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes) - UMR 6226, Rennes, France.
A natural water sampled after a sand filtration step and spiked with four organic micropollutants (metolachlor ESA, metolachlor NOA, desethylatrazine and metaldehyde) was treated by a loose nanofiltration membrane. The Steric, Electric, and Dielectric model (SEDE model) was then used to predict the separation performance of the membrane towards the various ions and micropollutants in the water matrix in order to study the transport mechanism of ions and micropollutants through the membrane. The SEDE model was found to satisfactorily predict the rejection sequences of inorganic anions and cations, as well as neutral (desethylatrazine and metaldehyde) and charged (metolachlor ESA and metolachlor NOA) micropollutants.
View Article and Find Full Text PDFAdv Mater
December 2024
Key Laboratory of Material Chemistry for Energy Conversion and Storage, Ministry of Education, Hubei Key Laboratory of Material Chemistry and Service Failure and Hubei Engineering Research Center for Biomaterials and Medical Protective Materials, Huazhong University of Science and Technology, Wuhan, 430074, P. R. China.
The development of zero-power moisture-harvesting technology in an unsaturated atmosphere is of great significance for coping with global freshwater scarcity. Here, inspired by Pachydactylus rangei's (Namib sand gecko) ability to evade thermal radiation and harvest moisture, a power-free cooling moisture harvester (PFCMH) is fabricated using the continuous, industrialized micro-extrusion compression molding. A Luneburg lens is introduced in the PFCMH for the first time, endowing it with a high reflectivity of ≈92.
View Article and Find Full Text PDFAdv Mater
December 2024
Hefei National Research Center for Physical Sciences at the Microscale, Department of Materials Science and Engineering, CAS Key Laboratory of Materials for Energy Conversion, University of Science and Technology of China, Hefei, Anhui, 230026, P. R. China.
The critical challenges in developing ultralow-temperature proton-based energy storage systems are enhancing the diffusion kinetics of charge carriers and inhibiting water-triggered interfacial side reactions between electrolytes and electrodes. Here an acid-salt hybrid electrolyte with a stable anion-cation-HO solvation structure that realizes unconventional proton transport at ultralow temperature is shown, which is crucial for electrodes and devices to achieve high rate-capacity and stable interface compatibility with electrodes. Through multiscale simulations and experimental investigations in the electrolyte employing ZnCl introduced into 0.
View Article and Find Full Text PDFHum Brain Mapp
January 2025
Department of Neuroscience and Biomedical Engineering, School of Science, Aalto University, Espoo, Finland.
State-of-the-art navigated transcranial magnetic stimulation (nTMS) systems can display the TMS coil position relative to the structural magnetic resonance image (MRI) of the subject's brain and calculate the induced electric field. However, the local effect of TMS propagates via the white-matter network to different areas of the brain, and currently there is no commercial or research neuronavigation system that can highlight in real time the brain's structural connections during TMS. This lack of real-time visualization may overlook critical inter-individual differences in brain connectivity and does not provide the opportunity to target brain networks.
View Article and Find Full Text PDFEnviron Res
December 2024
School of Chemistry and Chemical Engineering, Chongqing University of Technology, Chongqing 400054, China. Electronic address:
Microbial loss significantly affects wastewater treatment efficiency. This study simulated the inoculation area of a self-developed biological doubling reactor (BDR) to evaluate the retention efficiency of seven different fillers for aerobic denitrifying bacteria. Over 90 days of continuous operation, the porous filler R3 demonstrated excellent performance, with OD values consistently exceeding 1.
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