Ground water in karst terrains is highly vulnerable to contamination due to the rapid transport of contaminants through the highly conductive conduit system. For contamination risk assessment purposes, information about hydraulic and geometric characteristics of the conduits and their hydraulic interaction with the fissured porous rock is an important prerequisite. The relationship between aquifer characteristics and short-term responses to recharge events of both spring discharge and physicochemical parameters of the discharged water was examined using a process-based flow and transport model. In the respective software, a pipe-network model, representing fast conduit flow, is coupled to MODFLOW, which simulates flow in the fissured porous rock. This hybrid flow model was extended to include modules simulating heat and reactive solute transport in conduits. The application of this modeling tool demonstrates that variations of physicochemical parameters, such as solute concentration and water temperature, depend to a large extent on the intensity and duration of recharge events and provide information about the structure and geometry of the conduit system as well as about the interaction between conduits and fissured porous rock. Moreover, the responses of solute concentration and temperature of spring discharge appear to reflect different processes, thus complementing each other in the aquifer characterization.
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http://dx.doi.org/10.1111/j.1745-6584.2006.00175.x | DOI Listing |
Nanoscale
December 2024
University of Chinese Academy of Sciences, Beijing 100049, China.
Polymers (Basel)
February 2024
Department of Geology, College of Resources and Civil Engineering, Northeastern University, Shenyang 110819, China.
In this study, organic polymer polyurethane grouting materials were prepared using isocyanate and polyether polyol as the main agents and various additives, the slurry coagulation process was investigated, and the mechanical properties of the polymer samples were tested to explore the influence of the density and soaking time of the polymer on the strength of the samples. The microstructure of the polymer was observed via electron microscopy, and relying on image analysis software, the structural parameters of the polymer cell were analyzed and calculated; the model equation between density and yield strength was established based on the strength model of porous materials developed by Gibson and Ashby. The results show that the initial viscosity and gel time of the polyurethane slurry decrease with the increase of the initial temperature, and the viscosity changes abruptly when the slurry reaches the gel point.
View Article and Find Full Text PDFCrit Rev Microbiol
September 2024
Department of Biotechnology, University of Science and Technology, Foy's Lake, Chittagong, Bangladesh.
Anaerobic fungi are known to migrate and establish a 3D network of biofilms (microbiomes) and live invisible in the rumen and terrestrial subsurface, deep-sea - marine, and anoxic environment. They deserve our attention to understand anoxic fungal ecology and functions and develop new products and solutions. Such fungi activate unique genes to produce various polysaccharidases deemed essential for degrading plants' lignocellulosic materials.
View Article and Find Full Text PDFBMC Musculoskelet Disord
June 2023
Department of Orthopaedic Surgery, Affiliated Hospital of Guilin Medical University, Guangxi Province, GuiLin, China.
Background: The aging of the population is a social problem faced by many countries in the world. With the increase in the elderly population, the number of patients with Kummell's disease is also gradually increasing. No study has demonstrated that Kummell's disease has a clear correlation with the foramen of a vertebrobasilar vein.
View Article and Find Full Text PDFPharm Res
February 2023
Postgraduate Program in Pharmacy (PGFAR), Federal University of Santa Catarina, Trindade, Florianopolis, SC, 88040-900, Brazil.
Vulvovaginal candidiasis (VVC) is an opportunistic and endogenous infection caused by a fungus of the Candida genus, which can cause pruritus, dysuria, vulvar edema, fissures and maceration of the vulva. The treatment of vaginal candidiasis is carried out mainly by antifungal agents of azole and polyene classes; however, fungal resistance cases have been often observed. For this reason, new therapeutic agents such as essential oils, probiotics and antimicrobial peptides are being investigated, which can be combined with conventional drugs.
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