Quantitative evaluation of water distribution from two and three-dimensional neutron images during the ponded infiltration

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68407700%3A21110%2F16%3A00300981" target="_blank" >RIV/68407700:21110/16:00300981 - isvavai.cz</a>

Výsledek na webu

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DOI - Digital Object Identifier

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Jazyk výsledku

angličtina

Název v původním jazyce

Quantitative evaluation of water distribution from two and three-dimensional neutron images during the ponded infiltration

Popis výsledku v původním jazyce

Modern imaging techniques such as neutron imaging (NI) provide spatial and temporal information about the water and air distribution within the porous media. This information during hydrological processes is important for evaluating current and developing new water transport models. NI is characterized by relatively short acquisition times (seconds) and high resolution of images (micrometers). The acquisition time increases with the better resolution and vice versa. Depending on a research focus (static or dynamic processes) the choice of parameters is of a high importance. At the same time, the appropriate data processing has to be applied to obtain results free of bias and artifacts. Ponded infiltration experiments were conducted on two soil samples packed into the quartz glass columns of inner diameter of 29 and 34 mm, respectively. First sample was prepared by packing of fine and coarse fractions of sand and the second sample was packed using coarse sand and disks of fine porous ceramic. Ponded infiltration experiments conducted on both samples were monitored by neutron radiography to produce two dimensional (2D radiograms) projection of images during the transient phase of infiltration. During the steady state flow stage of experiments neutron tomography was utilized to obtain three-dimensional (3D tomograms) information on gradual water redistribution. The acquired radiographic images were normalized for background noise and spatial inhomogeneity of the detector, fluctuations of the neutron flux in time and for spatial inhomogeneity of the neutron beam. The radiograms of dry sample were subtracted from all subsequent radiograms to determine water thickness in the 2D projection images. The results from the correction is 2D water thickness maps of the sample. Tomography images were reconstructed from corrected water thickness maps to obtain the 3D spatial distribution of water content within the sample which can be compared with results of mathematical models.

Název v anglickém jazyce

Quantitative evaluation of water distribution from two and three-dimensional neutron images during the ponded infiltration

Popis výsledku anglicky

Modern imaging techniques such as neutron imaging (NI) provide spatial and temporal information about the water and air distribution within the porous media. This information during hydrological processes is important for evaluating current and developing new water transport models. NI is characterized by relatively short acquisition times (seconds) and high resolution of images (micrometers). The acquisition time increases with the better resolution and vice versa. Depending on a research focus (static or dynamic processes) the choice of parameters is of a high importance. At the same time, the appropriate data processing has to be applied to obtain results free of bias and artifacts. Ponded infiltration experiments were conducted on two soil samples packed into the quartz glass columns of inner diameter of 29 and 34 mm, respectively. First sample was prepared by packing of fine and coarse fractions of sand and the second sample was packed using coarse sand and disks of fine porous ceramic. Ponded infiltration experiments conducted on both samples were monitored by neutron radiography to produce two dimensional (2D radiograms) projection of images during the transient phase of infiltration. During the steady state flow stage of experiments neutron tomography was utilized to obtain three-dimensional (3D tomograms) information on gradual water redistribution. The acquired radiographic images were normalized for background noise and spatial inhomogeneity of the detector, fluctuations of the neutron flux in time and for spatial inhomogeneity of the neutron beam. The radiograms of dry sample were subtracted from all subsequent radiograms to determine water thickness in the 2D projection images. The results from the correction is 2D water thickness maps of the sample. Tomography images were reconstructed from corrected water thickness maps to obtain the 3D spatial distribution of water content within the sample which can be compared with results of mathematical models.

Druh

O - Ostatní výsledky

CEP obor

DF - Pedologie

OECD FORD obor

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Projekt

<a href="/cs/project/GA14-03691S" target="_blank" >GA14-03691S: Izotermické a neizotermické proudění vody a transport látek v pórovitém prostředí v blízkosti nasycení</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2016

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů