This paper describes the design and analysis of a well test for determining hydraulic properties of a low permeability, low porosity formation that potentially contains a small amount of free methane. Estimation of gas-related parameters in such formations is difficult using standard pumping tests because (i) pressures and flow rates may fluctuate as a consequence of gas exsolution during the t...

abstract to estimate spatial variability of soil hydraulic functions, scaling methods were developed and have been widely used. among these functions, physically based methods have been found more desirable because of possibility of estimating soil hydraulic functions from soil physical properties. in this paper, a new and physically based method has been described for scaling soil hydraulic co...

This paper examines the effect of friction model on the simulation accuracy of a hydraulic cylinder by using three friction models: a steady-state friction model, the LuGre model, and the new modified LuGre model. Hydraulic cylinder’s behaviors were measured under sinusoidal input to the servo valve. Simulations were conducted under the same conditions as the experiments. The comparisons of sim...