scholarly journals Heat as a tracer for understanding transport processes in fractured media: Theory and field assessment from multiscale thermal push-pull tracer tests

2016 ◽  
Vol 52 (7) ◽  
pp. 5442-5457 ◽  
Author(s):  
Maria V. Klepikova ◽  
Tanguy Le Borgne ◽  
Olivier Bour ◽  
Marco Dentz ◽  
Rebecca Hochreutener ◽  
...  
Keyword(s):  
Tracer Tests ◽  
Transport Processes ◽  
Fractured Media ◽  
Media Theory ◽  
Field Assessment ◽  
Heat As A Tracer

Anisotropy of Seismic Attenuation in Fractured Media: Theory and Ultrasonic Experiment

2008 ◽  
Vol 79 (1) ◽  
pp. 1-14 ◽  
Author(s):  
T. I. Chichinina ◽  
I. R. Obolentseva ◽  
G. Ronquillo-Jarillo
Keyword(s):  
Seismic Attenuation ◽  
Fractured Media ◽  
Media Theory

scholarly journals Elucidation of Flow and Transport Processes in a Variably Saturated System of Interlayered Sediment and Fractured Rock Using Tracer Tests

2007 ◽  
Vol 6 (4) ◽  
pp. 855-867 ◽  
Author(s):  
Catherine L. Duke ◽  
Robert C. Roback ◽  
Paul W. Reimus ◽  
Robert S. Bowman ◽  
Travis L. McLing ◽  
...  
Keyword(s):  
Fractured Rock ◽  
Tracer Tests ◽  
Transport Processes ◽  
Flow And Transport

Determination of rock transport parameters using short-term radionuclides and nanoparticles

2020 ◽  
Author(s):  
Milan Zuna ◽  
David Dobrev ◽  
Václava Havlová ◽  
Pavel Kůs ◽  
Daniela Doubravová ◽  
...  
Keyword(s):  
3D Visualization ◽  
Tracer Tests ◽  
Transport Processes ◽  
Detection Methods ◽  
Transport Parameters ◽  
Detection Techniques ◽  
Rock Samples ◽  
Radionuclide Distribution ◽  
On Line ◽  
Computational Analyses

<p>The aim of the project is to develop and test the short-lived radionuclides in order to describe the contaminant transport processes radionuclides, tracer metals and nanoparticles in the environment. Furthermore, the aim is also to develop on-line detection methods to quantify the processes that influence their movement towards the biosphere. Use of short lived radionuclide in tracer tests brings an advantage of excellent detection and avoids contamination of rock samples/environment during experiments.</p><p>The research is focused predominantly on radio-tracers in various forms (solute/nanoparticles) and on development of advanced detection techniques for their monitoring and display. The following pre-selected radionuclides were considered for potential  irradiation (<sup>24</sup>Na, <sup>42</sup>K, <sup>64</sup>Cu, <sup>72</sup>Ga, <sup>76</sup>As, <sup>82</sup>Br, <sup>99</sup>Mo, <sup>140</sup>La, <sup>142</sup>Pr, <sup>198</sup>Au, <sup>166</sup>Ho, <sup>188</sup>Re, <sup>153</sup>Sm). After thorough evaluation, holmium and rhenium compounds were selected for irradiation in the LVR- 15 reactor (CVŘ Řež), namely holmium oxide (Ho<sub>2</sub>O<sub>3</sub>) and ammonium perphenate (NH<sub>4</sub>ReO<sub>4</sub>). Those compounds were selected based on the computational analyses. Solutions of 50, 200, 300 MBq (<sup>188</sup>Re) and 300 MBq (<sup>166</sup>Ho) were finally prepared for detection tests. Paralelly, a method for the preparation of chromium oxide nanoparticles was introduced and tested.</p><p>A miniaturized spectral camera MiniPIX TPX3 has been developed for radionuclide detection. It is similar to the MiniPIX with a Timepix3 chip, a new generation of chips developed by the collaboration Medipix3. The camera has a resolution of 256 x 256 pixels with a pixel size of 55 x 55 µm (2 mm CdTe sensor).</p><p>The developed measurement system enables on-line monitoring and 3D visualization of the radioactivity distribution in the studied rock samples with respect to radionuclide distribution within the rock. Various measurement configurations were tested with respect to source activity, detector/collimator distance, and rock thickness to find optimal measurement parameters.</p><ul><li>The work described herein was funded by the project of the Ministry of Industry and Trade in the TRIO program (FV30430)</li> </ul>

scholarly journals Solute transport in fractured media – analysis of non-reversibility in tracer tests

2008 ◽  
Vol 15 (5) ◽  
pp. 783-791 ◽  
Author(s):  
N. E. V. Rodrigues ◽  
J. L. M. P. de Lima ◽  
F. F. Cruz
Keyword(s):  
Solute Transport ◽  
Laboratory Experiments ◽  
Tracer Tests ◽  
Media Analysis ◽  
Fractured Media ◽  
Small Scale ◽  
Natural Environments ◽  
Transport Models ◽  
Set Up

Abstract. This paper describes several small-scale (laboratory) experiments designed to simulate solute transport through fractured formations. A block of granite was broken to produce a fracture similar to those found in natural environments. Seven holes were drilled in the block to intersect the fracture. Later these holes functioned as either inlet or outlet points. All the possible combinations of pairs of inlet-outlet points were used to set up the tracer tests that provided the data analysed in this paper. The results indicate that reverse tracer tests do not necessarily provide symmetric results. Under some circumstances, the non-reversibility might be used to detect differences in the morphology of the fracture. The results also indicate that it is possible to estimate reasonably well the volume available for the circulation of the fluid by using transport models that neglect diffusion.

scholarly journals Comparison of Surface Roughness and Transport Processes of Sawed, Split and Natural Sandstone Fractures

Water ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2530 ◽  
Author(s):  
Sascha Frank ◽  
Thomas Heinze ◽  
Stefan Wohnlich
Keyword(s):  
Surface Roughness ◽  
Tracer Tests ◽  
Breakthrough Curves ◽  
Transport Processes ◽  
Natural Fracture ◽  
Transport Parameters ◽  
Fracture Surfaces ◽  
Advection Dispersion ◽  
Hydraulic Aperture ◽  
Surface Morphologies

In single fractures, dispersion is often linked to the roughness of the fracture surfaces and the resulting local aperture distribution. To experimentally investigate the effects of diverse fracture types and surface morphologies in sandstones, three fractures were considered: those generated by sawing and splitting, and a natural sedimentary fracture. The fracture surface morphologies were digitally analyzed and the hydraulic and transport parameters of the fractures were determined from Darcy and the tracer tests using a fit of a continuous time random walk (CTRW) and a classical advection–dispersion equation (ADE). While the sawed specimen with the smoothest surface had the smallest dispersivity, the natural fracture has the largest dispersivity due to strong anisotropy and non-matching fracture surfaces, although its surface roughness is comparable to the split specimen. The parameterization of the CTRW and of the ADE agree well for β > 4 of the truncated power law. For smaller values of β, non-Fickian transport processes are dominant. Channeling effects are observable in the tracer breakthrough curves. The transport behavior in the fractures is controlled by multiple constraints such as several surface roughness parameters and the equivalent hydraulic aperture.

Experiment on Water Infiltration and Solute Migration in Porous and Fractured Media

2014 ◽  
Vol 955-959 ◽  
pp. 1993-1997 ◽  
Author(s):  
Jing Wen Song ◽  
Ming Yu Wang ◽  
Da Wei Tang
Keyword(s):  
Porous Media ◽  
Water Flow ◽  
Solute Concentration ◽  
Transport Processes ◽  
Fractured Media ◽  
Water Infiltration ◽  
Typical Structure ◽  
Fracture Structure ◽  
Flow Features ◽  
And Migration

The experiments were performed by considering the upper loose porous media and lower fractured media as a typical structure of vadose zones, and by constructing the corresponding physical model to simulate water flow and solute transport processes in order to investigate water flow features and migration mechanism. It has been indicated that in the porous and fractured complex media, if the lower fracture structure remains unchanged, the structure and permeability of the porous media offer considerable impact on infiltration processes. Additionally, if the structure and permeability of the porous media remain unchanged, the overall permeability and flow features of the fracture structure are significantly controlled by fracture configurations. Furthermore, for the fracture structures with different fracture configurations, it is indicated that increasing of the density of the vertical fractures results in much more enhancement of the solute concentration decay rate than that caused by increasing the density of the horizontal ones. This investigation was expected to be of scientific significance and practical value for effective groundwater protection.

scholarly journals Review: Advances in the methodology and application of tracing in karst aquifers

2021 ◽  
Vol 29 (1) ◽  
pp. 67-88
Author(s):  
Ralf Benischke
Keyword(s):  
Fluorescent Dyes ◽  
Anthropogenic Impacts ◽  
Karst Aquifer ◽  
Tracer Tests ◽  
Analytical Techniques ◽  
Transport Processes ◽  
Karst Hydrogeology ◽  
Flow Paths ◽  
Tracer Methods ◽  
Underground Flow

AbstractTracer methods have been widely used in many fields of environmental and natural sciences, and also in human health sciences. In particular, tracers are used in the study of karst hydrogeology, typically focusing on phenomena such as sinkholes, sinking rivers and large karst springs. It is known that tracers have been used since antiquity. The aim of tracer tests has been to investigate underground flow paths, transport processes and water–rock interactions, and to get an insight into the functioning of a karst aquifer. In karst hydrogeology, tracer methods are the most important investigation tools beside conventional hydrological methods. In early times, tracer methods were applied only to investigate underground flow-paths. Later they were also used to elucidate transport processes associated with water flow, and today they are often the basis, together with detailed hydrological information, of groundwater protection investigations and aquifer modelling. Many substances (spores, microspheres, bacteriophages, salt tracers, fluorescent dyes, radioactive substances) have been investigated for their properties and potential usage in environmental investigations, in particular the often unknown and inaccessible underground systems of karst areas. A great number of analytical techniques is available. This includes instrumentation for laboratory applications and direct online, on-site or in-situ field measurements. Modern instruments have a high capability for data acquisition, storage and transmission in short intervals, as a basis for quantitative evaluation and modelling. This enables research on the hydrological and hydrochemical dynamics of aquifers and their response to different natural or anthropogenic impacts.

A discrete modeling framework for reservoirs with complex fractured media: Theory, validation and case studies

2018 ◽  
Vol 170 ◽  
pp. 945-957 ◽  
Author(s):  
Wenchao Fang ◽  
Chuanxi Liu ◽  
Junjian Li ◽  
Hanqiao Jiang ◽  
Jun Pu ◽  
...  
Keyword(s):  
Case Studies ◽  
Fractured Media ◽  
Media Theory ◽  
Modeling Framework ◽  
Discrete Modeling

scholarly journals Transport Processes in Porous Media by Self-Potential Method

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Valeria Giampaolo ◽  
Daniela Calabrese ◽  
Enzo Rizzo
Keyword(s):  
Electrical Potential ◽  
Tracer Tests ◽  
Time Lapse ◽  
Potential Method ◽  
Transport Processes ◽  
Comsol Multiphysics ◽  
Sharp Reduction ◽  
Controlled Diffusion ◽  
Longitudinal Dispersivity ◽  
Self Potential

A controlled diffusion/infiltration column experimental activity was carried out with the aim of monitoring the leakage of a salty water plume by time-lapse self-potential (SP) measurements. In particular, three tracer tests with different NaCl concentrations (6.00, 1.00, and 0.25 g L−1) were performed and all the measured SP signals showed a sharp reduction corresponding to the arrival of saline front with negative electrical potential values (−78.99±3.24 mV, −54.52±2.28 mV, and −24.12±1.21 mV) which decrease with increasing volume of tracer introduced into the column. Then, measured self-potential values were converted into salt concentration ones by the Planck-Henderson equation and sand diffusion(D)and longitudinal dispersivity (αL) values were estimated by modelling the transport equations in the COMSOL Multiphysics environment. Finally, the results show that measured and estimated NaCl concentrations are well correlated.

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