Effective Hydraulic Conductivity of Three‐Dimensional Heterogeneous Formations of Lognormal Permeability Distribution: The Impact of Connectivity

This study was conducted in the framework of the PILOT CO2-DISSOLVED project, which provides an additional approach for CO2 sequestration, with the aims of capturing, injecting, and locally storing the CO2 after being dissolved in brine. The brine acidity is expected to induce chemical reactions with the mineral phase of the host reservoir. A set of continuous radial CO2 flow experiments was performed on cylindrical carbonate rock samples under geological storage conditions. The objective was to interpret the dissolution network morphology and orientation involved. To explore the three-dimensional architecture of dissolution arrays and their connection integrity within core samples, we used computed tomography. A structural investigation at different scales revealed the impact of the rock heterogeneity on the dissolution pathways. The initial strike of the observed mesoscopic wormholes appears to be parallel to dilatational fractures, with a subsequent change in major trends of dissolution along master shears or, more specifically, a combination of synthetic shears and secondary synthetic shears. Antithetic shears organize themselves as slickolitic surfaces, which may be fluid-flow barriers due to different mineralogy, thus affecting the permeability distribution-wormhole growth geometry induced by CO2-rich solutions.

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Analysis of the Saltwater Wedge in a Coastal Karst Aquifer with a Double Conduit Network, Numerical Simulations and Sensitivity Analysis

Water ◽

10.3390/w11112311 ◽

2019 ◽

Vol 11 (11) ◽

pp. 2311

Author(s):

Alessandra Feo ◽

Andrea Zanini ◽

Emma Petrella ◽

Rebeca Hernàndez-Diaz ◽

Fulvio Celico

Keyword(s):

Hydraulic Conductivity ◽

Numerical Simulations ◽

Karst Aquifer ◽

Three Dimensional ◽

Karstic Aquifer ◽

Fractured Medium ◽

Coastal Karst ◽

Saltwater Wedge ◽

The Impact ◽

Conduit Network

We investigate the long-distance salinity in a dual permeability coastal karst aquifer with a double conduit network using a three-dimensional variable-density groundwater flow and multispecies transport SEAWAT model. Sensitivity analyses were used to evaluate the impact of the parameters and boundary conditions on the modeling saltwater wedge in a karstic aquifer situated in the Cuban land territory, including hydraulic conductivity, vertical anisotropy and salinity concentration; both in the conduits network and the fractured medium. These analyses indicated that hydraulic conductivity of the fractured medium and salt concentration were the ones that have a stronger effect on saltwater intrusion in a karstic aquifer. We also show results of the three-dimensional numerical simulations on groundwater salinity for different scenarios with the variabilities of the important parameters and compare results with electric conductivity profiles measured in a well.

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Investigations of Hydraulic Properties in Crystalline Rock.

MRS Proceedings ◽

10.1557/proc-26-255 ◽

1983 ◽

Vol 26 ◽

Author(s):

Leif Carlssn ◽

Anders Winberg ◽

Björn Rosander

Keyword(s):

Rock Mass ◽

Hydraulic Conductivity ◽

Hydraulic Properties ◽

Water Injection ◽

Three Dimensional ◽

Crystalline Rock ◽

Fracture Frequency ◽

Effective Hydraulic Conductivity ◽

Constant Head ◽

Total Fracture

ABSTRACTHydraulic properties of crystalline rock from four potential repository sites in Sweden were analysed. The hydraulic conductivity of the bedrock was established by means of transient water-injection tests with constant head conducted in 25 m sections. The bedrock at the sites was divided into different hydraulic units. An effective hydraulic conductivity was calculated for the rock mass at each site. This was done on the basis of the frequency distribution of all measured values within this unit. A log-nornal distribution was found to fit the data reasonably well. Regression analysis of hydraulic conductivity as a function of depth indicated similar relationships between the four sites. At a depth of 500 m the effective hydraulic conductivity for three-dimensional flow was about 5.10-11 m/s.The fracture frequency of the sites was established from existing core-logs. At depths of about 500 m the mean fracture frequency of the rock mass at the four sites was 1.8-2.5 fractures per meter. Of this total fracture frequency only a a certain proportion is considered to be hydraulically conductive. This proportion was established from results of hydraulic tests perforned in 2 or 3 m sections. Results obtained indicated a frequency of hydraulically conductive fractures of 0.1-0.3 fractures per meter in the rock mass at depths below 300 m.

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Analyzing the Impact of X-Ray Tomography on the Reliability of Integrated Circuits

ISTFA 2015: Conference Proceedings from the 41st International Symposium for Testing and Failure Analysis ◽

10.31399/asm.cp.istfa2015p0154 ◽

2015 ◽

Author(s):

Halit Dogan ◽

Md Mahbub Alam ◽

Navid Asadizanjani ◽

Sina Shahbazmohamadi ◽

Domenic Forte ◽

...

Keyword(s):

Integrated Circuits ◽

Integrated Circuit ◽

3D Imaging ◽

Three Dimensional ◽

Serial Sectioning ◽

Promising Technique ◽

Flash Memories ◽

X Ray ◽

3D Information ◽

The Impact

Abstract X-ray tomography is a promising technique that can provide micron level, internal structure, and three dimensional (3D) information of an integrated circuit (IC) component without the need for serial sectioning or decapsulation. This is especially useful for counterfeit IC detection as demonstrated by recent work. Although the components remain physically intact during tomography, the effect of radiation on the electrical functionality is not yet fully investigated. In this paper we analyze the impact of X-ray tomography on the reliability of ICs with different fabrication technologies. We perform a 3D imaging using an advanced X-ray machine on Intel flash memories, Macronix flash memories, Xilinx Spartan 3 and Spartan 6 FPGAs. Electrical functionalities are then tested in a systematic procedure after each round of tomography to estimate the impact of X-ray on Flash erase time, read margin, and program operation, and the frequencies of ring oscillators in the FPGAs. A major finding is that erase times for flash memories of older technology are significantly degraded when exposed to tomography, eventually resulting in failure. However, the flash and Xilinx FPGAs of newer technologies seem less sensitive to tomography, as only minor degradations are observed. Further, we did not identify permanent failures for any chips in the time needed to perform tomography for counterfeit detection (approximately 2 hours).

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On Probability Distribution of Hydraulic Conductivity in Variably Saturated Bimodal Heterogeneous Formations

Vadose Zone Journal ◽

10.2136/vzj2008.0114 ◽

2009 ◽

Vol 8 (3) ◽

pp. 611-622 ◽

Cited By ~ 8

Author(s):

David Russo

Keyword(s):

Hydraulic Conductivity ◽

Probability Distribution ◽

Heterogeneous Formations

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Numerical simulation of the impact of an integrated renovation project on the Maowei Sea hydrodynamic environment

Scientific Reports ◽

10.1038/s41598-021-96441-1 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Cui Wang ◽

Ling Cai ◽

Yaojian Wu ◽

Yurong Ouyang

Keyword(s):

Water Exchange ◽

Land Reclamation ◽

Three Dimensional ◽

Exchange Capacity ◽

Reclamation Project ◽

Hydrodynamic Environment ◽

Sea Area ◽

Water Quality Models ◽

The Impact ◽

Main Factor

AbstractIntegrated renovation projects are important for marine ecological environment protection. Three-dimensional hydrodynamics and water quality models are developed for the Maowei Sea to assess the hydrodynamic environment base on the MIKE3 software with high resolution meshes. The results showed that the flow velocity changed minimally after the project, decreasing by approximately 0.12 m/s in the east of the Maowei Sea area and increasing by approximately 0.01 m/s in the northeast of the Shajing Port. The decrease in tidal prism (~ 2.66 × 106 m3) was attributed to land reclamation, and accounted for just 0.86% of the pre-project level. The water exchange half-life increased by approximately 1 day, implying a slightly reduced water exchange capacity. Siltation occurred mainly in the reclamation and dredging areas, amounting to back-silting of approximately 2 cm/year. Reclamation project is the main factor causing the decrease of tidal volume and weakening the hydrodynamics in Maowei Sea. Adaptive management is necessary for such a comprehensive regulation project. According to the result, we suggest that reclamation works should strictly prohibit and dredging schemes should optimize in the subsequent regulation works.

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Mechanical Behavior of Hydroxyapatite-Chitosan Composite: Effect of Processing Parameters

Minerals ◽

10.3390/min11020213 ◽

2021 ◽

Vol 11 (2) ◽

pp. 213

Author(s):

Hamid Ait Said ◽

Hassan Noukrati ◽

Hicham Ben Youcef ◽

Ayoub Bayoussef ◽

Hassane Oudadesse ◽

...

Keyword(s):

Molecular Weight ◽

Compressive Strength ◽

Mechanical Strength ◽

Bone Repair ◽

Mechanical Stability ◽

Three Dimensional ◽

Processing Parameters ◽

Composite Effect ◽

Solid Liquid ◽

The Impact

Three-dimensional hydroxyapatite-chitosan (HA-CS) composites were formulated via solid-liquid technic and freeze-drying. The prepared composites had an apatitic nature, which was demonstrated by X-ray diffraction and Infrared spectroscopy analyses. The impact of the solid/liquid (S/L) ratio and the content and the molecular weight of the polymer on the composite mechanical strength was investigated. An increase in the S/L ratio from 0.5 to 1 resulted in an increase in the compressive strength for HA-CSL (CS low molecular weight: CSL) from 0.08 ± 0.02 to 1.95 ± 0.39 MPa and from 0.3 ± 0.06 to 2.40 ± 0.51 MPa for the HA-CSM (CS medium molecular weight: CSM). Moreover, the increase in the amount (1 to 5 wt%) and the molecular weight of the polymer increased the mechanical strength of the composite. The highest compressive strength value (up to 2.40 ± 0.51 MPa) was obtained for HA-CSM (5 wt% of CS) formulated at an S/L of 1. The dissolution tests of the HA-CS composites confirmed their cohesion and mechanical stability in an aqueous solution. Both polymer and apatite are assumed to work together, giving the synergism needed to make effective cylindrical composites, and could serve as a promising candidate for bone repair in the orthopedic field.

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Impact of inter-reader contouring variability on textural radiomics of colorectal liver metastases

European Radiology Experimental ◽

10.1186/s41747-020-00189-8 ◽

2020 ◽

Vol 4 (1) ◽

Author(s):

Francesco Rizzetto ◽

Francesca Calderoni ◽

Cristina De Mattia ◽

Arianna Defeudis ◽

Valentina Giannini ◽

...

Keyword(s):

Liver Metastases ◽

Hausdorff Distance ◽

Intraclass Correlation ◽

Three Dimensional ◽

Liver Lesion ◽

Dice Coefficient ◽

Rf Values ◽

Enhanced Computed Tomography ◽

Relative Change ◽

The Impact

Abstract Background Radiomics is expected to improve the management of metastatic colorectal cancer (CRC). We aimed at evaluating the impact of liver lesion contouring as a source of variability on radiomic features (RFs). Methods After Ethics Committee approval, 70 liver metastases in 17 CRC patients were segmented on contrast-enhanced computed tomography scans by two residents and checked by experienced radiologists. RFs from grey level co-occurrence and run length matrices were extracted from three-dimensional (3D) regions of interest (ROIs) and the largest two-dimensional (2D) ROIs. Inter-reader variability was evaluated with Dice coefficient and Hausdorff distance, whilst its impact on RFs was assessed using mean relative change (MRC) and intraclass correlation coefficient (ICC). For the main lesion of each patient, one reader also segmented a circular ROI on the same image used for the 2D ROI. Results The best inter-reader contouring agreement was observed for 2D ROIs according to both Dice coefficient (median 0.85, interquartile range 0.78–0.89) and Hausdorff distance (0.21 mm, 0.14–0.31 mm). Comparing RF values, MRC ranged 0–752% for 2D and 0–1567% for 3D. For 24/32 RFs (75%), MRC was lower for 2D than for 3D. An ICC > 0.90 was observed for more RFs for 2D (53%) than for 3D (34%). Only 2/32 RFs (6%) showed a variability between 2D and circular ROIs higher than inter-reader variability. Conclusions A 2D contouring approach may help mitigate overall inter-reader variability, albeit stable RFs can be extracted from both 3D and 2D segmentations of CRC liver metastases.

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