9 research outputs found
Reconstruction of climatic change quantitatively with dissolved noble gases in groundwaters
The isotopic evidence of gas source of the cold mineral springs with high pCO2 in Wudalianchi
Geothermal driving force: A new additional non-gravity action driving the migration of geothermal water in the Xinzhou geothermal field of Yangjiang, Guangdong
The "nested multilevel flow system" summarized by Tóth and the gravity driven groundwater flow system theory summarized by Zhang Renquan et al are the important theoretical basis for groundwater migration.Groundwater flow may be affected by gravitational potential, compaction potential and tectonic compression force.However, the anomalous phenomenon that the groundwater recharge area is lower than the groundwater drainage area is found in the convective hydrothermal system.As the temperature rises, the density of geothermal water decreases and the pressure increases, and the actual pressure head of geothermal water increases, which is the physical basis for this abnormal phenomenon.This paper defines the additional pressure head as "geothermal driving force", which is related to the temperature, salinity and viscosity of geothermal water.And we propose a quantitative calculation method.In the case of Xinzhou geothermal field in Yangjiang, Guangdong Province, the starting point of the geothermal driving force is located at the deepest part of the geothermal water cycle of 4.34 km, where the standard head of the geothermal driving force generated by temperature rise is +351.59 m, and the standard head of the geothermal driving force generated by salinity increase is -2.78 m, and the standard head of total geothermal driving force is +348.81 m.The higher the geothermal water temperature is, the greater the geothermal driving force is.The greater the salinity, the smaller the geothermal driving force.The additional supporting effect of geothermal driving force can accelerate the circulation of groundwater in hydrothermal system
Effects of advanced traffic signal status warning systems on vehicle emission reductions at signalized intersections
Signalized intersections have been identified as vehicle emission hotspots, where drivers decelerate, idle, and accelerate their vehicles in response to signal changes. Advanced traffic signal status warning systems (ATSSWSs) can be applied to reduce traffic emissions at intersections by mitigating unnecessary braking and acceleration. In this study, two types of ATSSWSs, variable message sign (VMS) based and vehicle-to-infrastructure (V2I) based, were designed, and their environmental effectiveness was evaluated through driving simulator-based experiments. Three scenarios were designed and tested: (1) baseline without an ATSSWS, (2) with the VMS-based ATSSWS, and (3) with the V2I-based ATSSWS. The Motor Vehicle Emission Simulator model was used to evaluate and compare the environmental effectiveness of these two types of ATSSWSs. The results indicate that the proposed ATSSWSs can reduce traffic emissions at signalized intersections. In particular, the V2I-based ATSSWS can substantially reduce CO2, NOx, CO, and HC emissions. The results will help transportation practitioners with implementing advanced driver information systems and decision making on emission reduction policies. Implications: Signalized intersection has been identified as one of hottest spots for vehicle emissions where signal control causes vehicles to frequently decelerate, idle, and accelerate. Advanced Traffic Signal Status Warning Systems (ATSSWS) can be applied to reduce traffic emission at intersections by decreasing vehicles’ unnecessary brakes and accelerations. The results of this study will assist transportation practitioners in implementing advanced driver information systems and making decisions on emission reduction policies