The variability of the interference pattern of a narrow-band sound signal in a shallow water waveguide in the horizontal plane in the presence of horizontal stratification, in particular due to linear internal waves, is studied. It is shown that lines of constant phase (a phase front) and lines of constant amplitude/envelope (an amplitude front) for each waveguide mode may have different directions in the spatial vicinity of the point of reception. The angle between them depends on the waveguide's parameters, the mode number, and the sound frequency. Theoretical estimates and data processing methodology for obtaining these angles from experimental data recorded by a horizontal line array are proposed. The behavior of the angles, which are obtained for two episodes from the Shallow Water 2006 (SW06) experiment, show agreement with the theory presented.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1121/1.5020274 | DOI Listing |
Sci Rep
January 2025
School of Urban Geology and Engineering, Hebei GEO University, 050031, Shijiazhuang, China.
Both over-exploitation and exploitation reduction of groundwater can alter the conditions of groundwater recharge and discharge, thereby impacting the overall quality of groundwater. This study utilizes hydrogeochemical methods and statistical analysis to explore the spatial and temporal evolution characteristics and influencing factors of groundwater chemistry in the saline-freshwater funnel area of Hengshui City under exploitation reduction. The results showed that: With the exception of the deep freshwater funnel area in the western region, which exhibits a trend of water quality deterioration (Cl accounted for more than 25%), groundwater quality in the other funnel areas demonstrates an improving trend (HCO[Formula: see text] accounted for more than 25%).
View Article and Find Full Text PDFPlants (Basel)
January 2025
Key Laboratory of Mountain Hazards and Earth Surface Processes, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610299, China.
Climate change has led to an increasing frequency of droughts, potentially undermining soil stability. In such a changing environment, the shallow reinforcement effect of plant roots often fails to meet expectations. This study aims to explore whether this is associated with the alteration of plant traits as a response to environmental change.
View Article and Find Full Text PDFSensors (Basel)
January 2025
State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Nanjing Hydraulic Research Institute, Nanjing 210029, China.
Water pipelines in water diversion projects can leak, leading to soil deformation and ground subsidence, necessitating research into soil deformation monitoring technology. This study conducted model tests to monitor soil deformation around leaking buried water pipelines using distributed fiber optic strain sensing (DFOSS) technology based on optical frequency domain reflectometry (OFDR). By arranging strain measurement fibers in a pipe-soil model, we investigated how leak location, leak size, pipe burial depth, and water flow velocity affect soil strain field monitoring results.
View Article and Find Full Text PDFBiology (Basel)
January 2025
Department of Science Education, National Taipei University of Education, 134 Section 2, Heping East Road, Taipei City 106, Taiwan.
The shallow-sea hydrothermal vent at Guishan Islet, located off the coast of Taiwan, serves as a remarkable natural site for studying microbial ecology in extreme environments. In April 2019, we investigated the composition of prokaryotic picoplankton communities, their gene expression profiles, and the dissolved inorganic carbon uptake efficiency. Our results revealed that the chemolithotrophs spp.
View Article and Find Full Text PDFJ Environ Sci (China)
July 2025
Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006, China. Electronic address:
Arsenic-contaminated groundwater is widely used in agriculture. To meet the increasing demand for safe water in agriculture, an efficient and cost-effective method for As removal from groundwater is urgently needed. We hypothesized that Fe (oxyhydr)oxide (FeOOH) minerals precipitated in situ from indigenous Fe in groundwater may immobilize As, providing a solution for safely using As-contaminated groundwater in irrigation.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!