Article
Engineering, Geological
Md Farhad Hasan, Hossam Abuel-Naga, E-C Leong
Summary: An electrical resistivity/conductivity model was proposed for isotropic saturated sand/clay mixture, and validated through laboratory experiments, achieving good agreement between model predictions and experimental measurements.
ENGINEERING GEOLOGY
(2021)
Article
Geosciences, Multidisciplinary
Youzheng Qi, Yuxin Wu
Summary: The conduction mechanism of clayey rocks and soils is influenced by variations in the electrical double layer and the intrinsic clay-and-water conduction pattern, resulting in a non-linear feature. By applying effective medium theory, an easy-to-use non-linear model has been developed that reflects electrochemical theories and explains measurement data well.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Engineering, Civil
Yongwei Fu, Robert Horton, Tusheng Ren, J. L. Heitman
Summary: In this study, a general form of Archie's model was developed to describe the relationship between soil electrical conductivity and volumetric water content. The new model performed well by providing estimates with root mean square errors in the range of 0.008-0.399 dS m(-1) and relative errors ranging from 0.7% to 29.8%, showing its potential for further evaluation on a wide range of soil conditions.
JOURNAL OF HYDROLOGY
(2021)
Article
Geosciences, Multidisciplinary
Wenqing Sun, Jianjun Jiang, Lidong Dai, Haiying Hu, Mengqi Wang, Yuqing Qi, Heping Li
Summary: The study found that the chromite content has a significant impact on the conductivity of the olivine-chromite systems, with the bulk conductivity increasing to a certain extent with increasing volume fraction of chromite. The results indicated that the percolation threshold of interconnectivity of chromite in the olivine-chromite systems is around 16 vol.%.
GEOSCIENCE FRONTIERS
(2021)
Article
Energy & Fuels
Zhiqi Zhong, Reza Rezaee, Matthew Josh, Lionel Esteban, Mohammad Sarmadivaleh
Summary: The study found that clays in shale formations provide additional conduction pathways, but their impact on water saturation is minimal. In contrast to conventional beliefs, it was shown that Archie's cementation exponent m does not monotonically increase with pore water conductivity, indicating that confining pressure and depth are the main causes of the non-Archie phenomenon.
JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING
(2022)
Article
Soil Science
Anders Bjorn Moller, Triven Koganti, Amelie Beucher, Bo Iversen, Mogens Humlekrog Greve
Summary: The study introduces a downscaling method that combines coarse-resolution soil maps with sensor data to improve predictions of soil properties. By utilizing relationships between soil properties and sensor data from other locations, the method can predict soil properties at specific locations more accurately.
Article
Agronomy
D. L. Corwin, E. Scudiero, D. Zaccaria
Summary: Climate change is expected to increase drought frequency and intensity in water-scarce agricultural areas that rely on irrigation. This study conducted a field experiment to develop improved soil sampling guidelines for mapping salinity patterns under drip-irrigation systems. The revised guidelines provide more accurate calibration between soil electrical conductivity and salinity, expanding the application of ECa-directed soil sampling in orchards under drip irrigation.
AGRICULTURAL WATER MANAGEMENT
(2022)
Article
Environmental Sciences
George Kargas, Paraskevi Londra, Kyriaki Sotirakoglou
Summary: The electrical conductivity of soil saturated paste extract (ECe) is commonly used to estimate soil salinity, but this method is time consuming. This study investigates a new model that incorporates soil texture to calculate the conversion factor (CF) between EC1:5 and ECe, resulting in improved prediction of ECe.
Article
Green & Sustainable Science & Technology
Muawia Dafalla
Summary: This study investigated the effects of saline water, specific chemicals, cement, and bentonite on sand-clay liners. It was found that adding bentonite grout improved hydraulic conductivity, while cement had a significant effect on compressibility. These findings can guide the design and assessment of sand-clay liners in semi-arid regions and coastal zones.
Article
Computer Science, Interdisciplinary Applications
Maryam Samavaki, Yusuf Oluwatoki Yusuf, Arash Zarrin Nia, Santtu Soderholm, Joonas Lahtinen, Fernando Galaz Prieto, Sampsa Pursiainen
Summary: This study presents a dynamic modeling approach for reconstructing the electrical conductivity atlas of the brain and simulating the effects of cerebral arterial circulation. By coupling the pressure-Poisson equation with Fick's law of diffusion, and using boundary conditions based on the Hagen-Poisseuille model, the researchers were able to estimate the blood pressure in cerebral arteries segmented from MRI data.
COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE
(2023)
Article
Agronomy
Daniel O'Brien, Michael Richardson, Douglas Karcher
Summary: Managing root zone moisture is crucial for the health and performance of sand-based golf course putting greens. Time domain reflectometry (TDR) is a widely accepted technology for measuring volumetric water content (VWC), but limited in its ability to measure VWC near the surface. This research aimed to expand the measurement capabilities of a TDR meter and successfully developed prediction models for estimating VWC in the uppermost 1.2 and 2.5 cm of sand-based putting greens.
Article
Geochemistry & Geophysics
Junkun Tan, Jiaqi Guo, Shifan Qiao, Changrui Dong, Ziyong Cai, Gang Wang
Summary: The research shows that under high stress, the shear behaviour between soil and structure can be fitted by a hyperbolic model, with influencing factors including normal stress, interface roughness, and moisture content.
Article
Agronomy
Alfonso Llanderal, Pedro Garcia-Caparros, Juana Isabel Contreras, Maria Teresa Lao, Maria Luz Segura
Summary: The experiment aimed to determine the spatial distribution and mobility of macronutrients in sand-mulched soils under greenhouse conditions. Results showed significant differences in nutrient concentrations based on soil type and depth, highlighting the importance of adjusting nutrient inputs for sustainable fertigation management.
Article
Geochemistry & Geophysics
Weikang Wan, Heying Hou, Tianxiang Li, Binghui Wang, Pengming Jiang, Aizhao Zhou
Summary: This paper investigates the effects of particle size, relative density, current frequency, and saturation on the contact resistance between calcareous sand and electrodes with different electrode spacings. The results show that the contact resistance increases with larger particle size and relative density. It decreases with increasing current frequency, and the decreasing amplitude decreases with increasing saturation. The relationship between contact resistance, current frequency, and saturation is established. The influence of contact resistance should be considered when studying the resistivity of calcareous sand using the two-electrode method, especially for samples with low saturation.
Article
Green & Sustainable Science & Technology
Ahmed M. Al-Mahbashi, Muawia Dafalla, Abdullah Shaker, Mosleh A. Al-Shamrani
Summary: The study reveals that clay sand mixtures undergo complex expansion and shrinkage during wetting and drying processes, impacting hydraulic conductivity. Results show that hydraulic conductivity initially increases and fluctuates before decreasing, with continuous monitoring demonstrating a gradual reduction over time.
Article
Engineering, Geological
Boyoung Yoon, Woojin Lee, Changho Lee, Hyunwook Choo
JOURNAL OF GEOTECHNICAL AND GEOENVIRONMENTAL ENGINEERING
(2020)
Article
Chemistry, Physical
Hyunwook Choo, Youngmin Choi, Woojin Lee, Changho Lee
Article
Engineering, Civil
Hyunwook Choo, Linh Van Ngo, Taeki Kim, Youngsang Kim, Changho Lee
KSCE JOURNAL OF CIVIL ENGINEERING
(2020)
Article
Chemistry, Multidisciplinary
Van-Linh Ngo, Changho Lee, Jae-Min Kim
Summary: The study found that structures located in layered soils experience changes in response to earthquakes, with an increase in roof motion of tall structures even as free-field motion decreases. This is because the presence of a soft layer alters the system's stiffness, affecting the kinematic and inertial interactions.
APPLIED SCIENCES-BASEL
(2021)
Article
Chemistry, Physical
Seongnoh Ahn, Jae-Eun Ryou, Kwangkuk Ahn, Changho Lee, Jun-Dae Lee, Jongwon Jung
Summary: This study compared the cement reinforcement method with the biopolymer reinforcement method using sodium alginate, finding that sodium alginate solution can have a similar reinforcing effect with a smaller amount of additive. However, the reinforcing effect decreases when the viscosity of the sodium alginate solution exceeds a certain value.
Article
Chemistry, Multidisciplinary
Van-Linh Ngo, Changho Lee, Eun-haeng Lee, Jae-Min Kim
Summary: This study utilized a nonlinear kinematic hardening (NKH) model and implemented a semi-automated procedure in MATLAB for fitting backbone curves, resulting in good matches with target curves. The results demonstrate the effectiveness of the procedure and NKH model in simulating the nonlinear properties of ground materials.
APPLIED SCIENCES-BASEL
(2021)
Article
Chemistry, Physical
Hyunwook Choo, Junghee Park, Thu Thi Do, Changho Lee
Summary: This study extends the modified Archie's equation to accurately measure the electrical conductivity of various clayey soils. The research found that surface conduction plays a crucial role in determining the electrical conductivity of clayey soils in low pore water conductivity environments. Additionally, there are strong correlations between the clay index properties and the unmeasurable parameters in the modified Archie's equation. The globally extended equation obtained from model validation can be used for estimating the electrical conductivity of in-situ clayey sediments.
APPLIED CLAY SCIENCE
(2022)
Article
Geosciences, Multidisciplinary
Hyunwook Choo, Changho Lee
Summary: The study reveals that shear wave velocity (V-s) in binary mixed soils is influenced by the packing density, depending on the size ratio of the small to large particles. When the size ratio is either greater than 0.414 or less than 0.155, V-s increases with packing density, while in the range of 0.155 to 0.414 with a finer fraction below a certain threshold, V-s decreases with increasing packing density.
JOURNAL OF APPLIED GEOPHYSICS
(2021)
Article
Construction & Building Technology
Rodney Ewusi-Wilson, Junghee Park, Boyoung Yoon, Changho Lee
Summary: This study employs geostatistical and artificial intelligence methods to estimate ground improvement after dynamic compaction. Results show that random forest spatial interpolation techniques outperform traditional geostatistical methods, and the artificial neural network model is compatible with physical and intuitive processes related to dynamic compaction. This unique approach is useful for geotechnical engineers when designing site improvement projects, particularly dynamic compaction for coarse-grained soils.
ADVANCES IN CIVIL ENGINEERING
(2022)
Article
Engineering, Civil
Emmanuel Ike, Junghee Park, Changho Lee
Summary: This study investigates the effect of pore fluid chemistry on sedimentation trends and liquid and plastic limits of different clayey soils. Different sedimentation trends are observed at different ion concentrations and pH conditions, and three sedimentation parameters are defined to capture the salient features of clay particles. The relationship between these parameters and the new fines classification chart can be useful to predict sedimentation modes of clays with different pore fluid chemistry.
KSCE JOURNAL OF CIVIL ENGINEERING
(2023)
Article
Chemistry, Physical
Boyoung Yoon, Hyunwook Choo, Changho Lee
Summary: Modern construction projects require innovative materials to improve safety, durability, and functionality. This study synthesized polyurethane on glass beads to enhance soil material functionality and evaluated their mechanical properties.
Article
Engineering, Civil
Hyunwook Choo, Woojin Lee, Changho Lee
Summary: This study evaluated the effect of curing time on the relationship between rho(mix) and UCS of sands grouted with microcement, aiming to estimate UCS over time based on rho(mix). Results show that curing time, particle size, and wc influence both rho(mix) and UCS, establishing a direct relationship between the two. However, the complex impact of curing time on the relation between UCS and rho(mix), as well as the nonlinear increase in UCS with time, presents challenges in capturing the interplay between UCS, rho(mix), and curing time.
GEOMECHANICS AND ENGINEERING
(2021)
Article
Chemistry, Analytical
Jong-Sub Lee, Geunwoo Park, Yong-Hoon Byun, Changho Lee
Article
Engineering, Civil
Hyunwook Choo, Youngmin Choi, Young-Uk Kim, Woojin Lee, Changho Lee
GEOMECHANICS AND ENGINEERING
(2020)
Article
Engineering, Civil
Van-Linh Ngo, Jae-Min Kim, Changho Lee
GEOMECHANICS AND ENGINEERING
(2019)
