Geological storage of acid gas has been identified as a promising approach to reduce atmospheric carbon dioxide(CO_(2)),hydrogen sulfide(H_(2)S)and alleviate public concern resulting from the sour gas production.A goo...Geological storage of acid gas has been identified as a promising approach to reduce atmospheric carbon dioxide(CO_(2)),hydrogen sulfide(H_(2)S)and alleviate public concern resulting from the sour gas production.A good understanding of the relative permeability and capillary pressure characteristics is crucial to predict the process of acid gas injection and migration.The prediction of injection and redistribution of acid gas is important to determine storage capacity,formation pressure,plume extent,shape,and leakage potential.Herein,the existing experimental data and theoretical models were reviewed to gain a better understanding of the issue how the H_(2)S content affects gas density,gas viscosity,interfacial tension,wettability,relative permeability and capillary pressure characteristics of acid gas/brine/rock systems.The densities and viscosities of the acid gas with different H_(2)S mole fractions are both temperature-and pressure-dependent,which vary among the gas,liquid and supercritical phases.Water/acid gas interfacial tension decreases strongly with increasing H_(2)S content.For mica and clean quartz,water contact angle increases with increasing H_(2)S mole fraction.In particular,wettability reversal of mica to a H_(2)S-wet behavior occurs in the presence of dense H_(2)S.The capillary pressure increases with decreasing contact angle.At a given saturation,the relative permeability of a fluid is higher when the fluid is nonwetting.The capillary pressure decreases with decreasing interfacial tension at a given saturation.However,the existing datasets do not show a consistent link between capillary number and relative permeability.The capillary pressure decreases with increasing H_(2)S mole fraction.However,there is no consensus on the effect of the H_(2)S content on the relative permeability curves.This may be due to the limited availability of the relative permeability and capillary pressure data for acid gas/brine/rock systems;thus,more experimental measurements are required.展开更多
Background: Young soccer players’injuries are receiving increased interest. The need of adopting injury prevention strategies to reduce financial, social and sport costs is obligated. The main purpose of this study i...Background: Young soccer players’injuries are receiving increased interest. The need of adopting injury prevention strategies to reduce financial, social and sport costs is obligated. The main purpose of this study is to analyse clinical characteristics of young soccer players in order to develop specific and effective injury prevention programs. Methods: This observational, transversal study includes 25 young soccer players from Spanish National League. Strength, motor control, flexibility and range of motion characteristics were analysed before the first preseason training. Results: Statistically significant differences were found for hip internal rotation (p value=0.001), Thomas test (p value =0.012) and ankle dorsiflexion test (p value=0.009) between both sides. Dorsiflexion test showed a positive correlation with the hip internal rotation ROM (p<0.016) and with the triple hop test (p<0.007). The hip internal rotation ROM showed a positive correlation with the Thomas test (p<0.033) and with the single leg squat test (p < 0.008). The drop jump test showed a positive correlation with the single leg squat test (p<0.039). Conclusions: Clinical characteristics shown in this study should be taken into account in order to develop specific injury prevention for this specific population. Moreover, data shown in this study can be used as norm values for young soccer semi-professional players in future researches.展开更多
基金the National Natural Science Foundation of China(Grant Nos.41872210 and 41274111)the Open Research Fund of State Key Laboratory of Geomechanics and Geotechnical Engineering(Grant No.Z018002)。
文摘Geological storage of acid gas has been identified as a promising approach to reduce atmospheric carbon dioxide(CO_(2)),hydrogen sulfide(H_(2)S)and alleviate public concern resulting from the sour gas production.A good understanding of the relative permeability and capillary pressure characteristics is crucial to predict the process of acid gas injection and migration.The prediction of injection and redistribution of acid gas is important to determine storage capacity,formation pressure,plume extent,shape,and leakage potential.Herein,the existing experimental data and theoretical models were reviewed to gain a better understanding of the issue how the H_(2)S content affects gas density,gas viscosity,interfacial tension,wettability,relative permeability and capillary pressure characteristics of acid gas/brine/rock systems.The densities and viscosities of the acid gas with different H_(2)S mole fractions are both temperature-and pressure-dependent,which vary among the gas,liquid and supercritical phases.Water/acid gas interfacial tension decreases strongly with increasing H_(2)S content.For mica and clean quartz,water contact angle increases with increasing H_(2)S mole fraction.In particular,wettability reversal of mica to a H_(2)S-wet behavior occurs in the presence of dense H_(2)S.The capillary pressure increases with decreasing contact angle.At a given saturation,the relative permeability of a fluid is higher when the fluid is nonwetting.The capillary pressure decreases with decreasing interfacial tension at a given saturation.However,the existing datasets do not show a consistent link between capillary number and relative permeability.The capillary pressure decreases with increasing H_(2)S mole fraction.However,there is no consensus on the effect of the H_(2)S content on the relative permeability curves.This may be due to the limited availability of the relative permeability and capillary pressure data for acid gas/brine/rock systems;thus,more experimental measurements are required.
文摘Background: Young soccer players’injuries are receiving increased interest. The need of adopting injury prevention strategies to reduce financial, social and sport costs is obligated. The main purpose of this study is to analyse clinical characteristics of young soccer players in order to develop specific and effective injury prevention programs. Methods: This observational, transversal study includes 25 young soccer players from Spanish National League. Strength, motor control, flexibility and range of motion characteristics were analysed before the first preseason training. Results: Statistically significant differences were found for hip internal rotation (p value=0.001), Thomas test (p value =0.012) and ankle dorsiflexion test (p value=0.009) between both sides. Dorsiflexion test showed a positive correlation with the hip internal rotation ROM (p<0.016) and with the triple hop test (p<0.007). The hip internal rotation ROM showed a positive correlation with the Thomas test (p<0.033) and with the single leg squat test (p < 0.008). The drop jump test showed a positive correlation with the single leg squat test (p<0.039). Conclusions: Clinical characteristics shown in this study should be taken into account in order to develop specific injury prevention for this specific population. Moreover, data shown in this study can be used as norm values for young soccer semi-professional players in future researches.
