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tracertechniques, etc ; aquifers; dyes; hydrodynamics; karsts; models; solutes; streams; water management; Vietnam; Show all 10 Subjects
Abstract:
... Colloidal particles are an important vector for the transport of contaminants in karst aquifers, characterized by a high degree of hydrologic variability. Understanding this heterogeneity and hydrogeological functioning is of particular importance for water management strategies. Until now, transport parameters for particles were mostly determined by injection of solutes or surrogates for natural ...
tracertechniques, etc ; aquifers; dioxane; oxidants; oxidation; porous media; sand; slugs; water pollution; Show all 9 Subjects
Abstract:
... The research presented herein investigates a peroxone activated persulfate (PAP) oxidant, commercialized under the trade name OxyZone®, and its effects on 1,4-Dioxane (dioxane) contaminated water under column scale conditions in the presence of porous material. There is a limited understanding of the underlying processes that govern PAP oxidation, including the oxidation rates in the presence of a ...
tracertechniques, etc ; diffusivity; electric power; permeability; porosity; renewable energy sources; sustainable development; Australia; Show all 8 Subjects
Abstract:
... Understanding of hydraulic heterogeneity of the reservoir is the basis for Enhanced geothermal systems (EGS) optimization. This, however, is challenging, as there are limited well tests available for reservoir characterization. To overcome this challenge, this study developed a methodology for determining hydraulic parameters by integrating the induced micro-seismic data collected during the hydra ...
tracertechniques, etc ; aquaculture; estuaries; freshwater; geomorphology; hydrodynamics; marine science; models; oxygen; seasonal variation; summer; water quality; winter; Portugal; Spain; Show all 15 Subjects
Abstract:
... Inshore aquaculture sustainability is extremely dependent on the efficiency of the water renewal at the culture sites, ensuring the supply of oxygen and nutrients to fish and/or bivalves. In this context, this study intends to investigate the effect of water quality on aquaculture development, assessing the water renewal rates in two contrasting coastal systems, Ria de Aveiro and Rias Baixas, unde ...
tracertechniques, etc ; aquifers; groundwater; groundwater flow; isotropy; Show all 5 Subjects
Abstract:
... Methods for interpreting tracer tests often rely on equations assuming a natural regional flow which is straight and uniform. The main purpose of this project was to develop more realistic equations for the advective part of contaminant transport, by including the flow lines distortion occurring in the vicinity of the injection well. The complex potential of the flow during a tracer test was calcu ...
tracertechniques, etc ; chemical communication; image analysis; longitude; nanocrystals; Show all 5 Subjects
Abstract:
... As a promising ¹⁹F MRI tracer, the relatively slow lattice-spin relaxation of CaF₂ nanocrystals leads to an unacceptable scanning time in MR imaging, hampering their application. We herein controlled the size and lattice distortion of CaF₂ nanocrystals and showed that the shortened interplanar spacing pronouncedly sped up the longitude relaxation. ...
tracertechniques, etc ; Lewis bases; acids; positron-emission tomography; Show all 4 Subjects
Abstract:
... ¹⁸F-Labeled organofluorophosphates are important radiosynthons that have only been previously accessible via¹⁸/¹⁹F-isotope-exchange with limited molar activities. Herein, a novel ¹⁸F-fluorination methodology has been developed to prepare ¹⁸F-labeled phosphorofluoridates and phosphonofluoridic acids via the [¹⁸F]F⁻ nucleophilic substitution of imidazole-activated precursors. The efficient one-step ...
tracertechniques, etc ; laminar flow; polymers; porous media; process design; Show all 5 Subjects
Abstract:
... Micromixers were fabricated from emulsion-templated macroporous polymers, known as polymerizing high internal-phase emulsions (polyHIPEs). Micromixers are mixing elements containing submillimeter channels, in which mixing occurs by molecular diffusion in the laminar flow regime. PolyHIPEs possess an interconnected pore structure with connected channels, which are ideal to mix liquids. We investiga ...
tracertechniques, etc ; aquifers; geometry; hydrodynamics; karsts; rivers; spatial variation; Show all 7 Subjects
Abstract:
... Tracer tests are widely used for characterizing hydrodynamics, from stream-scale to basin-wide scale. In karstic environments, the positioning of field fluorometers (or sampling) is mostly determined by the on-site configuration and setup difficulties. Most users are probably aware of the importance of this positioning for the relevance of data, and single-point tests are considered reliable. Howe ...
tracertechniques, etc ; equations; fluorescein; groundwater; models; sediment-water interface; solutes; stream channels; Show all 8 Subjects
Abstract:
... We propose a dye tracer method to characterize fluid and solute fluxes across the sediment‐water interface. Zones of groundwater discharge within the streambed are first identified, and small volume slugs of 0.5 to 1 mL fluorescein dye are released at known subsurface depths. Fluorescein dye allows for visual identification of interface breakthrough locations and times, and dye concentrations at t ...
Amélie Vanlierde; Frédéric Dehareng; Nicolas Gengler; Eric Froidmont; Sinead McParland; Michael Kreuzer; Matthew Bell; Peter Lund; Cécile Martin; Björn Kuhla; Hélène Soyeurt
tracertechniques, etc ; agriculture; data collection; lactation; methane; milk; milk yield; phenotype; prediction; regression analysis; Show all 10 Subjects
Abstract:
... BACKGROUND: A robust proxy for estimating methane (CH₄) emissions of individual dairy cows would be valuable especially for selective breeding. This study aimed to improve the robustness and accuracy of prediction models that estimate daily CH₄ emissions from milk Fourier transform mid‐infrared (FT‐MIR) spectra by (i) increasing the reference dataset and (ii) adjusting for routinely recorded pheno ...
tracertechniques, etc ; diffusion; diffusivity; mass; mass transfer; models; paper; solids; technology; turbulent flow; velocity; Show all 11 Subjects
Abstract:
... Rigorous simulation of mass transfer process in liquid-solid circulating fluidized bed (LSCFB) system is challenging not only due to the fluidization but also due to the existing turbulence. In this paper, the recently developed c2¯−εc approach is introduced to characterize the turbulent mass diffusion in LSCFB riser so that the empirical turbulent mass diffusivity are abandoned. As for describing ...
tracertechniques, etc ; agronomy; dyes; fluorescence; overland flow; quantitative analysis; quinine; soil; surface water; ultraviolet radiation; Show all 10 Subjects
Abstract:
... This study presents a tracer technique based on the fluorescent properties of quinine to help on the visualization of shallow flows and allow a quantitative measurement of overland flow velocities. Laboratory experiments were conducted to compare the traditional dye tracer and thermal tracer techniques with this novel fluorescent (quinine) tracer by injecting a quinine solution and the other trace ...
... Flow velocity is one of the most important hydrodynamic variables for both channelized (rill and gullies) and interrill erosive phenomena. The dye tracer technique to measure surface flow velocity Vₛ is based on the measurement of the travel time of a tracer needed to cover a known distance. The measured Vₛ must be corrected to obtain the mean flow velocity V using a factor αᵥ = V/Vₛ which is gene ...
tracertechniques, etc ; alanine; bioretention areas; chemical analysis; green infrastructure; soil; stormwater; technology; triazoles; urban runoff; water pollution; Show all 11 Subjects
Abstract:
... Bioretention cells can effectively infiltrate stormwater runoff and partly remove conventional water contaminants. A field tracer injection experiment in a conventionally designed bioretention cell was used to investigate the fate of benzotriazole, a model trace organic contaminant, during and between runoff events. Moderate (29%) benzotriazole load reductions were measured during the 6 h long inj ...
... Diffusion through a water saturated silty clay soil column was measured for six perfluoroalkyl acids (PFAAs), including perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS). An aqueous pore diffusion model, which incorporated linear adsorption parameters measured independently in batch tests and a tortuosity factor determined independently using a bromide tracer test, was used to ...
... Twenty-five biogenic and anthropogenic secondary organic aerosol (SOA) markers have been measured over a one-year period in both gaseous and PM₁₀ phases in the Paris region (France). Seasonal and chemical patterns were similar to those previously observed in Europe, but significantly different from the ones observed in America and Asia due to dissimilarities in source precursor emissions. Nitroaro ...
Peter J. Moate; Jennie E. Pryce; Leah C. Marett; Josie B. Garner; Matthew H. Deighton; Brigid E. Ribaux; Murray C. Hannah; William J. Wales; S. Richard O. Williams
tracertechniques, etc ; air temperature; automation; diet; dry matter intake; methane; methane production; rain; relative humidity; spring; sulfur hexafluoride; wind speed; Show all 12 Subjects
Abstract:
... Despite the fact that the sulphur hexafluoride (SF₆) tracer technique was developed over 25 years ago to measure methane production from grazing and non-housed animals, no studies have specifically investigated whether ambient wind speed, temperature, relative humidity and rainfall influence the accuracy of the method. The aim of this research was to investigate how these weather factors influence ...
tracertechniques, etc ; heat transfer; models; solutes; tomography; Germany; Show all 6 Subjects
Abstract:
... Hydraulic properties are well known to be essential in controlling fluid flow, solute migration, and heat transport in fractured subsurface. However, accurate characterization of hydraulic properties including the locations of conductive fracture and their hydraulic conductivities as well as their cross-well connectivity is still challenging. In this work, we modified the inversion framework of tr ...
... Subsurface flow plays an important role in the functioning of wetlands and in the maintenance of their ecosystem services. Specifically, the transport and exchange of dissolved matter between sediments and surface waters is regulated by subsurface flow, which can strongly affect ecological zonation and productivity. Having a quantitative understanding of this subsurface flow is therefore important ...