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You searched for subject:(pore fluid conductivity). Showing records 1 – 3 of 3 total matches.

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1. Shen, Yuanjie. Long-term response of soils subjected to repetitive geoenvironmental loads.

Degree: PhD, Civil and Environmental Engineering, 2018, Georgia Tech

Repetitive loading cycles originate from a variety of natural and industrial processes, affect soil properties and the long-term performance of geotechnical systems. This thesis provides unprecedented experimental data and physical analyses of repetitive environmental loading cycles on geomaterials. Research tools adopted in this study include long-term experiments in multi-physics cells, microfluidics, seismic and NMR monitoring, and analytical solutions. The void ratio evolves towards the terminal void ratio as the number of wet-dry cycles increases. Shear wave velocity data indicate that the soil fabric becomes less sensitive to stress changes after repetitive wet-dry cycles. Changes in the soil-water characteristic curve demonstrate that fine-grained soil fabric evolves towards a new stable fabric as the number of wet-dry cycles increases. Precipitation within dual-porosity microfluidic chips provides new insight into salt crystallization phenomena in geomaterials, such as fractured rocks. Deformable PDMS captures the effect of the crystallization force. Pore network topology and surface wetting characteristics govern crystal growth patterns. Pore fluid chemistry cycles in fine-grained soils alter particle level electrical forces and particle-particle associations. The soil fabric evolves with cycles of pore fluid chemistry and leads to chemical-mechanical coupled response. Atmospheric pressure cycles accelerate water transport in unsaturated soils and promote moisture homogenization. The amount of water loss due to pressure cycles is inversely proportional to the number of cycles, and efficiency is frequency dependent. This study highlights the behavior of sands and fines subjected to repetitive geoenvironmental loads under various boundary conditions. The physics-inspired and data-driven approaches applied in this research can be used to enhance the existing design guidelines of geo-structures for long-term performance, serviceability, and safety. Advisors/Committee Members: Santamarina, Carlos J. (advisor), Burns, Susan E. (advisor), Frost, David J. (committee member), Dai, Sheng (committee member), Goldsztein, Guillermo (committee member).

Subjects/Keywords: Climate change; Repetitive loading; Wet-dry cycles; Atmospheric pressure; Pore fluid chemistry; Unsaturated soil; Salt precipitation; Electrical conductivity; Shear wave velocity; Microfluidic chip; Bender elements; Nuclear magnetic resonance spectroscopy

pore fluid exchanges and wet-dry induced precipitation alter the hydraulic conductivity, void… …salt precipitates. 57 Figure 4.1 Device. Schematic diagram of the pore fluid circulation… …characteristics govern crystal growth patterns. Pore fluid chemistry cycles in fine-grained soils alter… …cycles of pore fluid chemistry and leads to chemical-mechanical coupled response. Atmospheric… …x29;, chemical cyclic changes in pore fluid (Musso et al. 2003), thermal cycles… 

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APA (6th Edition):

Shen, Y. (2018). Long-term response of soils subjected to repetitive geoenvironmental loads. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/60793

Chicago Manual of Style (16th Edition):

Shen, Yuanjie. “Long-term response of soils subjected to repetitive geoenvironmental loads.” 2018. Doctoral Dissertation, Georgia Tech. Accessed February 27, 2021. http://hdl.handle.net/1853/60793.

MLA Handbook (7th Edition):

Shen, Yuanjie. “Long-term response of soils subjected to repetitive geoenvironmental loads.” 2018. Web. 27 Feb 2021.

Vancouver:

Shen Y. Long-term response of soils subjected to repetitive geoenvironmental loads. [Internet] [Doctoral dissertation]. Georgia Tech; 2018. [cited 2021 Feb 27]. Available from: http://hdl.handle.net/1853/60793.

Council of Science Editors:

Shen Y. Long-term response of soils subjected to repetitive geoenvironmental loads. [Doctoral Dissertation]. Georgia Tech; 2018. Available from: http://hdl.handle.net/1853/60793

2. Ghanbarian-Alavijeh, Behzad. Modeling Physical and Hydraulic Properties of Disordered Porous Media: Applications from Percolation Theory and Fractal Geometry.

Degree: PhD, Environmental Sciences PhD, 2014, Wright State University

A fundamental component of the hydrologic cycle is the movement of fluids in the pore space of geological formations and soils. Prediction of the motion of fluids in such porous materials requires first modeling the physical properties of the medium itself, and second, invoking a capable theory to describe fluid transport in tortuous interconnected pathways. In this dissertation, for the former we use fractal geometry since most phenomena in nature are fractal, and for the latter percolation theory is applied because it has successfully described flow and transport in disordered networks and media. We propose models for the soil water retention curve and tortuosity. We also focus on modeling different kinds of transport, such as air permeability, gas and solute diffusion, unsaturated hydraulic conductivity, and dispersion. Applications of critical path based analyses of flow and conduction properties reveals asymmetry between the saturation dependence of the air and water permeabilities as well as distinctions between the electrical and hydraulic conductivities. In particular, the saturation dependence of the hydraulic conductivity is strongly dependent on the pore size distribution, but that of the electrical conductivity is only weakly so, and the air permeability is not dependent. Gas diffusion relates more closely to the air permeability, while solute diffusion is, under a wide range of circumstances, tied directly to the electrical conductivity. Comparisons with experiment confirmed this.Applying critical path analysis and universal scaling from percolation theory to media that could be treated within the pore-solid fractal (PSF) approach, we developed unimodal and bimodal models for unsaturated hydraulic conductivity in porous media. Predictions were developed for unsaturated hydraulic conductivity using the soil water retention curve. To evaluate our unimodal model we used 104 experiments from the UNSODA database and compared with two other models. The results obtained indicated that our non-universal percolation based model predicted unsaturated hydraulic conductivity better than the other two models. In order to evaluate the bimodal models for soil water retention and unsaturated hydraulic conductivity curves, we compared them with 8 measured experiments collected from the UNSODA database. Although the bimodal unsaturated hydraulic conductivity model was fitted well to the experiments, we found discrepancy between measurements and predictions. We found that the predictions were relatively more successful for the first regime at large water contents than the second regime at low water contents.The universal scaling law from percolation theory was confirmed for the saturation dependence of the air permeability. Analyzing two independent databases including 39 experiments showed that the experimental exponent was 2.028 ± 0.028 and 1.814 ± 0.386 for the first and second databases, respectively. We found the extracted exponent in the power law fit is most sensitive to the measured values of the air permeability… Advisors/Committee Members: Hunt, Allen (Advisor), Skinner, Thomas (Advisor).

Subjects/Keywords: Environmental Science; Petroleum Engineering; Soil Sciences; Hydrology; Geology; Geophysics; Fluid Dynamics; Environmental Engineering; Agriculture; Agricultural Engineering; Civil Engineering; Chemical Engineering; Geophysical; Geological; Hydrologic Sciences; Physics; Theoretical Mathematics; Percolation theory, Fractals, Porous media, Dispersion, Unsaturated hydraulic conductivity, Air permeability, Diffusion, Tortuosity, Saturation dependence, Pore-size distribution

Pore size scaling of the hydraulic conductivity with the range of water content given in… …conductivity models ...............................................64 3.3. Electrical conductivity… …120 VI. UNIMODAL AND BIMODAL MODELS OF UNSATURATED HYDRAULIC CONDUCTIVITY… …122 Article VII. Unsaturated Hydraulic Conductivity in Porous Media: Percolation Theory… …124 2.1. Pore-size distribution… 

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Ghanbarian-Alavijeh, B. (2014). Modeling Physical and Hydraulic Properties of Disordered Porous Media: Applications from Percolation Theory and Fractal Geometry. (Doctoral Dissertation). Wright State University. Retrieved from http://rave.ohiolink.edu/etdc/view?acc_num=wright1401380554

Chicago Manual of Style (16th Edition):

Ghanbarian-Alavijeh, Behzad. “Modeling Physical and Hydraulic Properties of Disordered Porous Media: Applications from Percolation Theory and Fractal Geometry.” 2014. Doctoral Dissertation, Wright State University. Accessed February 27, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=wright1401380554.

MLA Handbook (7th Edition):

Ghanbarian-Alavijeh, Behzad. “Modeling Physical and Hydraulic Properties of Disordered Porous Media: Applications from Percolation Theory and Fractal Geometry.” 2014. Web. 27 Feb 2021.

Vancouver:

Ghanbarian-Alavijeh B. Modeling Physical and Hydraulic Properties of Disordered Porous Media: Applications from Percolation Theory and Fractal Geometry. [Internet] [Doctoral dissertation]. Wright State University; 2014. [cited 2021 Feb 27]. Available from: http://rave.ohiolink.edu/etdc/view?acc_num=wright1401380554.

Council of Science Editors:

Ghanbarian-Alavijeh B. Modeling Physical and Hydraulic Properties of Disordered Porous Media: Applications from Percolation Theory and Fractal Geometry. [Doctoral Dissertation]. Wright State University; 2014. Available from: http://rave.ohiolink.edu/etdc/view?acc_num=wright1401380554

3. Taylor, Kendrick C. Application of borehole geophysical methods to shallow groundwater investigations.

Degree: 1987, University of Nevada – Reno

Borehole geophysical methods have been used extensively for petroleum and mineral exploration; but due to differences in environment and survey objective, modifications of both equipment and interpretation are necessary for shallow groundwater applications. These applications require the use of complementary borehole measurements which can be related to the formation properties by comparison to core samples. Different interpretation strategies must be developed for different environments, strategies for use in unsaturated, saturated with clay present, saturated without clay present, and hydraulically anisotropic environments are developed. Parameters that can be determined are porosity, moisture content, hydraulic conductivity, groundwater velocity, cation exchange content, and pore fluid conductivity. All logging instrumentation measures a property over a short interval of the well. It is important when combining logs to insure that all logs used in the comparison are vertical averages of the same portion with respect to both depth and length of the well. It is also possible to reduce the effect of the vertical averaging by the instrumentation through the use of numerical techniques. A field example is used to demonstrate these methods. The techniques presented make it practical to determine a formation hydraulic properties on a scale of a few tens of centimeters. This high resolution distribution of the formation in turn permits the development of a class of contaminate transport models which utilize the high resolution description of the aquifer variability. These models do not require large scale dependent dispersity terms to match field data because the contaminate movement is realistically described by shear flow in the high resolution advective flow field of the model. A one dimensional model is presented as an example of this class of model. Advisors/Committee Members: Wheatcraft, Stephen (advisor).

Subjects/Keywords: borehole geophysical methods; petroleum exploration; mineral exploration; environment; survey objective; modifications of equipment; modifications of interpretation; shallow groundwater applications; complimentary borehole measurements; formation properties; core; clay; samples; interpretation strategies; unsaturated with clay present; saturated with clay present; saturated without clay present; hydraulically anisotropic environments; porosity; moisture content; hydraulic conductivity; groundwater velocity; cation exchange content; pore fluid conductivity; logging instrumentation measures; wells; logs; vertical averages; depth of wells; length of wells; numerical techniques; formation hydraulic properties; high resolution distribution; contaminate transport models; high resolution description; aquifer variability; dependent diversity; contaminate movement; shear flow; high resolution advective flow field; Mackay Science Project; groundwater  – sampling; groundwater flow; hydraulic measurements; hydrogeology

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Taylor, K. C. (1987). Application of borehole geophysical methods to shallow groundwater investigations. (Thesis). University of Nevada – Reno. Retrieved from http://hdl.handle.net/11714/1743

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Taylor, Kendrick C. “Application of borehole geophysical methods to shallow groundwater investigations.” 1987. Thesis, University of Nevada – Reno. Accessed February 27, 2021. http://hdl.handle.net/11714/1743.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Taylor, Kendrick C. “Application of borehole geophysical methods to shallow groundwater investigations.” 1987. Web. 27 Feb 2021.

Vancouver:

Taylor KC. Application of borehole geophysical methods to shallow groundwater investigations. [Internet] [Thesis]. University of Nevada – Reno; 1987. [cited 2021 Feb 27]. Available from: http://hdl.handle.net/11714/1743.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Taylor KC. Application of borehole geophysical methods to shallow groundwater investigations. [Thesis]. University of Nevada – Reno; 1987. Available from: http://hdl.handle.net/11714/1743

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

.