Measurement uncertainty is a key hindrance to the quanti_cation of water ~uxes at all scales of investigation[ Predictions of soil!water ~ux rely on accurate or representative measurements of hydraulic gradients and _eld! state hydraulic conductivity[ We quanti_ed the potential magnitude of errors associated with the parameters and variables used directly and indirectly within the DarcyÐBucking...

Hydraulic fracturing technology is usually used to stimulate tight gas reservoirs for increasing gas production. The stimulated volume depends in part on the pre-existing natural fractures in a reservoir. The mechanisms influencing the interaction between hydraulic fractures and natural fractures have to be well understood in order to achieve a successful application of hydraulic fracturing. In...

The main goal of the study is to analyze all relevant properties of the electro hydraulic systems and based on that to make a proper choice of the control strategy that may be used for the control of the servomechanism system. A combination of electronic and hydraulic systems is widely used since it combines the advantages of both. Hydraulic systems are widely spread because of their properties...

The paper aims to develop a novel pitch control system for a large wind turbine driven by a variable-speed pump-controlled hydraulic servo system. To perform practical pitch control experiments, a full-scale test rig of the hydraulic pitch control system for a 2 MW wind turbine’s blade, including a novel pitch control mechanism, a variable-speed pump-controlled hydraulic servo system, a disturb...

A theoretical method is proposed to estimate post-fracturing fracture size and transmissivity, and as a test of the methodology, data collected from two wells were used for verification. This method can be employed before hydrofracturing in order to obtain estimates of the potential hydraulic benefits of hydraulic fracturing. Five different pumping test analysis methods were used to evaluate th...

Stochastic modeling of soil water fluxes in the absence of measured hydraulic parameters requires a knowledge of the expected istribution of the hydraulic parameters in different soil types. Predictive relationships describing the hydraulic parameter distributions must be developed based on the common descriptors of the physical properties of soils (e.g., texture, structure, particle size distr...

39 S oil hydraulic parameters are essential input to most hydrologic and climatic models (Mohanty et al., 2002; Mohanty and Zhu, 2007). Th ey are used to defi ne the hydraulic characteristics of the soil vital in modeling soil moisture and fl ux in the unsaturated zone near the land–atmosphere boundary. At the scale of model applications, it is very important to defi ne the appropriate paramete...