Article
Astronomy & Astrophysics
Arpan Das, Tuhin Malik, Alekha C. Nayak
Summary: This study investigates the effects of density dependent dark matter on the mass, radius, and tidal deformability of neutron stars. By adopting a two fluid formalism, it is found that the interaction between dark matter and nuclear matter occurs solely through gravitational interaction. The unknown parameters in the equation of state for dark matter are determined using Bayesian parameter optimization technique.
Article
Materials Science, Multidisciplinary
Masanori Kohno
Summary: The type of clay mineral affects the swelling characteristics and permeability of clays, which are closely related to specific surface area. Hydraulic conductivity can be estimated based on specific surface area and void ratio of compacted clays.
MATERIALS TRANSACTIONS
(2021)
Article
Engineering, Civil
Pei-Ning Li, Ye-Shuang Xu, Xu-Wei Wang
Summary: This study proposes a new modified K-C equation considering the derivation principle of the original K-C equation. By applying Poiseuille's law in porous media, the concept of 2D porosity (epsilon) and a correction coefficient for permeation (f) are presented. The parameters in the new modified K-C equation include specific surface area (S-0), tortuosity (1/cos theta), and ne. The prediction formulas for S-0 and 1/cos theta are deduced and verified by comparing them with established formulas and experimental data. The new modified K-C equation is adequate for predicting hydraulic conductivity for clay and sand by comparing it with experimental values and other established modified K-C equations.
JOURNAL OF HYDROLOGY
(2023)
Article
Engineering, Civil
Jidong Teng, Antai Dong, Han Yan, Chenxi Tong, Sheng Zhang
Summary: In this study, a new hydraulic conductivity model for frozen coarse-grained soils is proposed based on the pattern of ice formation from the pore wall. The model shows better prediction results compared to existing models, particularly for sand. It can serve as a useful tool for simulating water-heat transfer process in cold regions.
JOURNAL OF HYDROLOGY
(2023)
Article
Engineering, Civil
Jidong Teng, Han Yan, Sihao Liang, Sheng Zhang, Daichao Sheng
Summary: The study developed a new hydraulic conductivity model for frozen soils based on the Kozeny-Carman equation, which can be used to explain the migration of water and heat in frozen soils compared to unfrozen soils. Parametric analysis revealed that unfrozen water saturation and shape coefficient ratio are important parameters affecting hydraulic conductivity. The proposed model can also be simplified to a power function for easy use.
JOURNAL OF HYDROLOGY
(2021)
Article
Engineering, Civil
Yu Zhong, Annan Zhou, Jiapei Du, Jidong Teng, Shui-long Shen
Summary: This study modifies the classical KC equation to consider the influence of clay surface characteristics and nanoscale pores on the saturated hydraulic conductivity in clayey soils. Through molecular dynamics modeling, a specific function is proposed to quantify the adsorbed proportion, and the modified equation is validated with experimental data, showing high accuracy.
JOURNAL OF HYDROLOGY
(2023)
Article
Astronomy & Astrophysics
Francesco Di Clemente, Alessandro Drago, Giuseppe Pagliara
Summary: A kilonova signal is expected after a black hole-neutron star merger, and the strength of the signal depends on the equation of state of neutron star matter. The recent analysis suggests a stiff equation of state, resulting in a strong kilonova signal. However, in a two-families scenario, the kilonova signal is weak.
ASTROPHYSICAL JOURNAL
(2022)
Article
Physics, Nuclear
A. Rahmansyah, A. Sulaksono
Summary: Studying the impact of anisotropic pressure models on neutron star properties and comparing the results with recent multimessenger constraints revealed compatibility in certain EOS conditions, yet the observed massive compact object is unlikely to be an anisotropic neutron star.
Article
Environmental Sciences
Yudi Yan, Seyyed Ali Akbar Nakhli, Jing Jin, Godfrey Mills, Clinton S. Willson, David R. Legates, Kalehiwot Nega Manahiloh, Paul T. Imhoff
Summary: This study investigates the impact of biochar on the K value of media, proposes models for predicting K values, and discovers the influence of biochar particle shape on pore structure and K values.
JOURNAL OF ENVIRONMENTAL MANAGEMENT
(2021)
Article
Astronomy & Astrophysics
Valeria Carvalho, Marcio Ferreira, Tuhin Malik, Constanca Providencia
Summary: This study utilizes Bayesian neural networks to directly decipher the internal composition of neutron stars based on their macroscopic properties. By analyzing simulated observations, the proton fraction and sound speed within the neutron star interiors can be inferred. The results demonstrate that Bayesian neural networks successfully recover the composition with reasonable levels of uncertainty.
Article
Environmental Sciences
Haike Wang, Hui Qian, Yanyan Gao
Summary: The study established a macropore structure model of loess using X-ray CT technology, revealing anisotropic pore variation. By modifying equations, the anisotropy of hydraulic conductivity was investigated, and the results were verified through permeability tests.
ENVIRONMENTAL EARTH SCIENCES
(2021)
Article
Engineering, Geological
Kunlin Ruan, Xian-Lei Fu
Summary: The Kozeny-Carman (KC) equation is a well-known relation between hydraulic conductivity and pore properties in porous material. This study proposes a modified KC equation based on a new dual-pore system to improve the prediction of saturated hydraulic conductivities of bentonites. The modification replaces critical parameters in the conventional KC equation with macroporosity and tortuosity of macropore, and calculates them based on the basal spacing of compacted bentonite. Compared with conventional KC equation and prediction method based on diffuse double layer (DDL) theory, the modified KC equation shows better fitting to the experimental data of bentonites' saturated hydraulic conductivity to a certain extent.
JOURNAL OF ROCK MECHANICS AND GEOTECHNICAL ENGINEERING
(2022)
Article
Chemistry, Physical
Tian Chen, Mao Du, Qiangling Yao
Summary: This study proposes a novel theoretical method for the evolution of the pore system in compacted bentonite based on its stacked microstructure. The Kozeny-Carman equation is revised to evaluate the hydraulic conductivity, taking into account the microstructure effects. A new constitutive relationship is developed to describe the unsaturated hydraulic conductivity. The results show good agreement between the predictions and experimental observations.
Article
Energy & Fuels
Hirokazu Ishitobi, Honoka Doki, Soshi Shiraishi, Hidehiko Tsukada, Yoshikiyo Hatakeyama, Takato Nakao, Nobuyoshi Nakagawa
Summary: This study analyzes the pressure drop issue in redox flow batteries and proposes an analytical model applicable to different materials. The results show that the interconnected pore structure of seamless carbon materials has a significant impact on battery performance, and there is a trade-off relationship between liquid permeability and current density.
JOURNAL OF ENERGY STORAGE
(2023)
Article
Physics, Nuclear
R. Somasundaram, I. Tews, J. Margueron
Summary: Neutron stars provide an opportunity to study the transition of matter at extreme densities, including the possibility of a phase transition to quark matter. This study investigates the density dependence of the speed of sound in neutron stars and examines whether nontrivial structures can be inferred from astrophysical observations. The findings suggest that a phase transition to quark matter is not required in the density range explored in the core of neutron stars based on current astrophysical information.
Article
Energy & Fuels
Abouzar Mirzaei-Paiaman, Mohsen Faramarzi-Palangar, Sofiane Djezzar, Shahin Kord
Summary: This paper introduces a new wettability index and tests other indices, finding that all indices predict the oil-wet character of tested rocks. There are correlations between different indices and variations in wettability indices with reservoir depth.
JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING
(2022)
Article
Energy & Fuels
Daniyar Bopbekov, Peyman Pourafshary, Randy Hazlett
Summary: Liquid loading is a common problem in gas wells, and knowing the onset time of liquid loading is crucial for cost reduction and production loss minimization. Accurate prediction of liquid loading requires knowledge of the critical gas velocity, and droplet models are commonly used for this purpose. However, the accuracy of droplet models varies across different conditions.
JOURNAL OF NATURAL GAS SCIENCE AND ENGINEERING
(2022)
Article
Chemistry, Multidisciplinary
Mohsen Faramarzi-Palangar, Abouzar Mirzaei-Paiaman, Seyyed Ali Ghoreishi, Behzad Ghanbarian
Summary: Various methods for evaluating reservoir rock wettability have been proposed. This study conducted experiments on a carbonate reservoir to evaluate and compare different quantitative and qualitative wettability indicators. The results showed consistency between relative permeability-based approaches and Amott-Harvey and USBM methods. The study also investigated the relationship between wettability indices and rock quality indicators.
APPLIED SCIENCES-BASEL
(2022)
Article
Chemistry, Multidisciplinary
Aizada Ganiyeva, Leila Karabayanova, Peyman Pourafshary, Muhammad Rehan Hashmet
Summary: Low salinity/engineered water injection is an effective enhanced oil recovery method, but its performance in heavy oil formations is limited. The strong capillary forces in heavy oil reservoirs outweigh the wettability alteration mechanism of low salinity water. Therefore, combining this method with thermal approaches is recommended.
APPLIED SCIENCES-BASEL
(2022)
Article
Energy & Fuels
Adilet Aliyev, Davood Zivar, Peyman Pourafshary
Summary: This study compares the interwell connectivity values estimated by tracer tests and the capacitance-resistance model (CRM) for synthetic and real fields, demonstrating that CRM can simulate waterflooding processes and accurately estimate production. CRM is recommended as a low-cost and quick tool for approximate estimation of interwell connectivity.
Review
Energy & Fuels
Marzhan Karimova, Razieh Kashiri, Peyman Pourafshary, Randy Hazlett
Summary: Fluid flow in naturally fractured reservoirs is complex and heterogeneous, and understanding fracture-matrix interactions is crucial. Fluid movement between fractures and matrix occurs through spontaneous imbibition, which can be affected by wettability. Low-salinity water injection is considered as an effective enhanced oil recovery approach for fractured and non-water-wet carbonate rocks. This review summarizes experimental and numerical studies on the imbibition process and highlights the need for further research on wettability alteration and simulation models for co/countercurrent flows in naturally fractured reservoirs.
Article
Chemistry, Physical
Rizwan Muneer, Peyman Pourafshary, Muhammad Rehan Hashmet
Summary: This study presents a new integrated model that incorporates electrostatic, gravitational, and hydrodynamic forces to accurately predict fines migration. Experimental validation demonstrated the accuracy of the model.
JOURNAL OF MOLECULAR LIQUIDS
(2023)
Article
Chemistry, Multidisciplinary
Rizwan Muneer, Muhammad Rehan Hashmet, Peyman Pourafshary, Mariam Shakeel
Summary: Nanoparticles have significant importance in modern science due to their unique characteristics and diverse applications. A research proposes the use of machine learning techniques to simulate the zeta potential of silica nanofluids and colloidal systems. The developed artificial neural network (ANN) model achieved an accuracy of over 97% in zeta potential predictions and proved to be more accurate and faster than conventional methods. This research provides a highly accurate and rapid prediction method with broad applications across different fields.
Article
Engineering, Multidisciplinary
Ali Lesan, Reza Shams, Peyman Pourafshary, Abbas Bahrodi, Hosna Rastkerdar
Summary: A pressure maintenance strategy is crucial for reservoir management, especially in single-phase oil reservoirs. Water injection is a common method to prevent pressure decline, and analytical and semi-analytical methods are used to analyze reservoir response and pressure alteration. The Static Capacitance-Resistance Model (SCRM) has been applied to estimate water injection in reservoirs with charging aquifers and to investigate water injection performance in the aquifer zone.
RESULTS IN ENGINEERING
(2023)
Article
Energy & Fuels
Laila Maratbekkyzy, Mariam Shakeel, Peyman Pourafshary, Darya Musharova
Summary: Polymer flooding is an effective method for improving oil recovery from reservoirs, especially those with heterogeneous formations and viscous crude oils. This study focuses on controlling polymer adsorption using silica nanoparticles and alkali, and it demonstrates that both silica nanoparticles and alkali can effectively reduce polymer adsorption. The results show that polymer-nanoparticle flooding can achieve a higher recovery factor compared to standalone polymer flooding, with 5% incremental recovery of the remaining oil.
Article
Energy & Fuels
Razieh Kashiri, Arman Garapov, Peyman Pourafshary
Summary: This study investigated the influence of pH on wettability alteration and oil recovery in carbonate-fractured porous media through imbibition at high temperatures. The test results demonstrated that the ultimate recovery factor remained consistent regardless of the pH levels, but the oil recovery rate varied significantly. The analysis indicated that calcite dissolution and the alkali effect were the primary mechanisms at different pH values.
Article
Energy & Fuels
Sabber Khandoozi, Peyman Pourafshary, Saule Aidarova, Altynay Sharipova
Summary: Foam flooding is a popular method for improving oil recovery in reservoirs with varying heterogeneity levels. Surfactant-assisted foam flooding (SF) is commonly used but has limitations in high-pressure, high-temperature, and high-salinity reservoirs. Researchers have proposed nanoparticles-assisted foam flooding (NAF) as a new approach to overcome these limitations. This study investigated the performance of SF and NAF in controlling gas mobility in reservoirs with different levels of heterogeneity. The results showed that both SF and NAF improved recovery factors, with NAF showing greater potential due to decreased gas mobility and saturation in the top layers.
Article
Chemistry, Physical
Nurzhan Askar, Rizwan Muneer, Peyman Pourafshary
Summary: This study investigates the influence of phase distribution and rock wettability on the critical salt concentration (CSC) for fines migration in sandstone oil reservoirs. The results show that a weak water-wet system results in a higher CSC value compared to a strong water-wet system due to fine particles being contained within a thin water film. These findings provide valuable insights for the design of production and enhanced oil recovery strategies in sandstone reservoirs.
JOURNAL OF MOLECULAR LIQUIDS
(2023)
Article
Energy & Fuels
Yaser Ahmadi, Mohsen Mansouri, Peyman Pourafshary
Summary: Developing new ZnO-TiO2/ZSM-5 nanocomposites (ZTZ) and comparing them to standalone ZSM-5 zeolite, this study investigates the improvements in fluid/rock interactions. Various methods including XRD, SEM, EDX, and BET were used to analyze the morphology of the nanocomposites. Results showed that ZTZ exhibited better stability conditions and altered capillary forces more effectively compared to standalone nanoparticles. Oil displacement tests revealed that ZTZ achieved accelerated production and 9% higher recovery compared to ZSM-5 flooding, making it a promising nanocomposite for EOR in sandstone formations.
PETROLEUM SCIENCE AND TECHNOLOGY
(2023)
Article
Chemistry, Physical
Fariza Amankeldi, Miras Issakhov, Peyman Pourafshary, Zhanar Ospanova, Maratbek Gabdullin, Reinhard Miller
Summary: This paper explores the potential of aggregates of surfactant and SiO2 nanoparticles as foam stabilizers for practical applications. It examines the effects of different chain lengths and concentrations of the cationic surfactant C(n)TAB on the performance of C(n)TAB-SiO2 nanofluids to understand their ability to stabilize foam. The results demonstrate improved foam stability in the presence of SiO2 nanoparticles, offering insights into foam stabilization and its potential in various industrial applications such as enhanced oil recovery and foam-based separation processes.
COLLOIDS AND INTERFACES
(2023)
