The Experts below are selected from a list of 312 Experts worldwide ranked by ideXlab platform
Jaewon Jang - One of the best experts on this subject based on the ideXlab platform.
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Relative water and Gas Permeability for Gas production from hydrate‐bearing sediments
Geochemistry Geophysics Geosystems, 2014Co-Authors: Nariman Mahabadi, Jaewon JangAbstract:Relative water and Gas Permeability equations are important for estimating Gas and water production from hydrate-bearing sediments. However, experimental or numerical study to determine fitting parameters of those equations is not available in the literature. In this study, a pore-network model is developed to simulate Gas expansion and calculate relative water and Gas Permeability. Based on the simulation results, fitting parameters for modified Stone equation are suggested for a distributed hydrate system where initial hydrate saturations range from Sh = 0.1 to 0.6. The suggested fitting parameter for relative water Permeability is nw ≈ 2.4 regardless of initial hydrate saturation while the suggested fitting parameter for relative Gas Permeability is increased from ng = 1.8 for Sh = 0.1 to ng = 3.5 for Sh = 0.6. Results are relevant to other systems that experience Gas exsolution such as pockmark formation due to sea level change, CO2 Gas formation during geological CO2 sequestration, and Gas bubble accumulation near the downstream of dams.
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relative water and Gas Permeability for Gas production from hydrate bearing sediments
Geochemistry Geophysics Geosystems, 2014Co-Authors: Nariman Mahabadi, Jaewon JangAbstract:Relative water and Gas Permeability equations are important for estimating Gas and water production from hydrate-bearing sediments. However, experimental or numerical study to determine fitting parameters of those equations is not available in the literature. In this study, a pore-network model is developed to simulate Gas expansion and calculate relative water and Gas Permeability. Based on the simulation results, fitting parameters for modified Stone equation are suggested for a distributed hydrate system where initial hydrate saturations range from Sh = 0.1 to 0.6. The suggested fitting parameter for relative water Permeability is nw ≈ 2.4 regardless of initial hydrate saturation while the suggested fitting parameter for relative Gas Permeability is increased from ng = 1.8 for Sh = 0.1 to ng = 3.5 for Sh = 0.6. Results are relevant to other systems that experience Gas exsolution such as pockmark formation due to sea level change, CO2 Gas formation during geological CO2 sequestration, and Gas bubble accumulation near the downstream of dams.
Nariman Mahabadi - One of the best experts on this subject based on the ideXlab platform.
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Relative water and Gas Permeability for Gas production from hydrate‐bearing sediments
Geochemistry Geophysics Geosystems, 2014Co-Authors: Nariman Mahabadi, Jaewon JangAbstract:Relative water and Gas Permeability equations are important for estimating Gas and water production from hydrate-bearing sediments. However, experimental or numerical study to determine fitting parameters of those equations is not available in the literature. In this study, a pore-network model is developed to simulate Gas expansion and calculate relative water and Gas Permeability. Based on the simulation results, fitting parameters for modified Stone equation are suggested for a distributed hydrate system where initial hydrate saturations range from Sh = 0.1 to 0.6. The suggested fitting parameter for relative water Permeability is nw ≈ 2.4 regardless of initial hydrate saturation while the suggested fitting parameter for relative Gas Permeability is increased from ng = 1.8 for Sh = 0.1 to ng = 3.5 for Sh = 0.6. Results are relevant to other systems that experience Gas exsolution such as pockmark formation due to sea level change, CO2 Gas formation during geological CO2 sequestration, and Gas bubble accumulation near the downstream of dams.
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relative water and Gas Permeability for Gas production from hydrate bearing sediments
Geochemistry Geophysics Geosystems, 2014Co-Authors: Nariman Mahabadi, Jaewon JangAbstract:Relative water and Gas Permeability equations are important for estimating Gas and water production from hydrate-bearing sediments. However, experimental or numerical study to determine fitting parameters of those equations is not available in the literature. In this study, a pore-network model is developed to simulate Gas expansion and calculate relative water and Gas Permeability. Based on the simulation results, fitting parameters for modified Stone equation are suggested for a distributed hydrate system where initial hydrate saturations range from Sh = 0.1 to 0.6. The suggested fitting parameter for relative water Permeability is nw ≈ 2.4 regardless of initial hydrate saturation while the suggested fitting parameter for relative Gas Permeability is increased from ng = 1.8 for Sh = 0.1 to ng = 3.5 for Sh = 0.6. Results are relevant to other systems that experience Gas exsolution such as pockmark formation due to sea level change, CO2 Gas formation during geological CO2 sequestration, and Gas bubble accumulation near the downstream of dams.
Frederic Skoczylas - One of the best experts on this subject based on the ideXlab platform.
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Experimental research on water retention and Gas Permeability of compacted bentonite/sand mixtures
Soils and Foundations, 2014Co-Authors: Jiangfeng Liu, Frederic Skoczylas, Jian LiuAbstract:Highly compacted bentonite-based materials are often considered as buffer or sealing materials for deep high-level radioactive waste repositories. In situ, the initial state of bentonite-based materials is only partially saturated, which has a very high suction that will promote water absorption from the host rock. In addition, a gradient of water saturation will be formed between the external part and the central part of the compacted bentonite blocks. In this paper, water retention tests, under both constant-volume and free-swelling conditions, were performed to investigate the suction behavior of a compacted bentonite/sand mixture. In order to investigate the sealing ability of the partially saturated bentonite/sand mixture, Gas Permeability tests were also carried out under the in situ confining stress. It was found that the confining conditions have a limited effect on the water retention capacity of the compacted bentonite/sand mixture at lower levels of relative humidity (RH), while this influence is significant at higher RH levels. The results of Gas Permeability tests show that Gas Permeability is very sensitive to the water content and the confining pressure. When the sample (stable at RH=98%) was subjected to a in situ confining pressure (7–8 MPa), the Gas Permeability was very low (1.83×10–14 m/s) which indicates that Gas tightness can be obtained even though the sample is not fully saturated.
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From relative Gas Permeability to in situ saturation measurements
Construction and Building Materials, 2013Co-Authors: Franck Agostini, Frederic SkoczylasAbstract:Abstract Water saturation is a key factor to assess the safety of concrete storage structures of radioactive waste. Our laboratory has developed a nondestructive method of measuring the in situ water saturation. A pulse sensor, designed to measure effective Gas Permeability, is firstly casted in the concrete structure. The in situ Gas Permeability is then periodically measured by analyzing the Gas flow rate through the pulse sensor. The relationship between relative Gas Permeability and liquid saturation of the same material is simultaneously determined by laboratory tests. A numerical simulation of in situ Gas flow is then performed, based on the above-mentioned relationship. The in situ saturation is finally deduced by comparing with numerical simulation results. This method has been validated by a laboratory study carried out on a mortar and in situ feasibility of this method has been also proven in an industrial context.
Yuan Liu - One of the best experts on this subject based on the ideXlab platform.
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Relationship between pore structure and Gas Permeability in poplar ( Populus deltoides CL.’55/65’) tension wood
Annals of Forest Science, 2020Co-Authors: Yujing Tan, Shan-shan Chang, Yuan Wei, Gonggang Liu, Qianqian Wang, Yuan LiuAbstract:The important anatomical changes in tension wood, e.g., the high fiber ratio and rich mesopores, did not significantly increase the air and nitrogen flow; thus the Gas Permeability in the longitudinal direction of poplar ( Populus deltoides CL.’55/65′) tension wood is actually affected by the cell tissue macroporous porosity. Gas Permeability is one of the most important physical properties of wood and is closely related to its internal microstructure, particularly porosity. Tension wood is widespread in woody plants and displays significant structural differences compared with opposite wood. The study was designed to clarify the relationship between pore structure and Gas Permeability in poplar tension wood. The Gas Permeability was measured using a self-made device. The meso- and macroporosity characteristics were measured by nitrogen adsorption–desorption and mercury intrusion porosimetry. The flow was simulated using ANSYS Fluent software to illustrate the role of pore structure on Permeability. The morphological features of vessels have an effect on wood Permeability. Compared with tension wood, opposite wood, which has higher vessel ratio, larger cell lumen diameter, and more rich pits, shows stronger Gas Permeability. Increasing the airflow path will actually reduce the Gas Permeability. The simulation results are consistent with the experimental results. In hardwoods, the Gas Permeability in the longitudinal direction is mainly dictated by the vessels. The high fiber ratio and rich mesopore in tension wood do not significantly increase Gas flow, suggesting the Permeability of wood was actually determined by the cell tissue with macroporous porosity. Vessel tissue ratio, length and diameter, and intervessel pit size were found responsible for influencing the Permeability in the longitudinal direction.
Jong Hak Kim - One of the best experts on this subject based on the ideXlab platform.
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Thermodynamic model of Gas Permeability in polymer membranes
Journal of Polymer Science Part B: Polymer Physics, 2007Co-Authors: Dokyoung Lee, Yong Woo Kim, Kyung Ju Lee, Byoung Ryul Min, Jong Hak KimAbstract:A new molecular thermodynamic model is developed of the Gas Permeability in polymer membranes on the basis of configurational entropy and Flory-Huggins theory to predict Permeability dependence on the concentration of penetrant. Three kinds of configurational entropy are taken into account by this model; that is, the disorientation entropy of polymer, the mixing entropy, and specific interaction entropy of polymer/Gas. The validity of the mathematical model is examined against experimental Gas Permeability for polymer membranes. Agreement between experimental and predicted Permeability is satisfactory.
