This paper studies the precision motion control of single-rod hydraulic actuators with accurate parameter estimations. An integrated direct/indirect adaptive robust controller (DIARC) is proposed to take into account the inherent nonlinearity, parametric uncertainties and uncertain nonlinearities associated with the hydraulic systems. Compared with existing direct ARC controller designs, the pr...

Reduction of hydraulic conductance to the canopy has been shown to result in stomatal responses to limit transpiration. To test for similar responses to perturbations of the hydraulic network in leaves, we simultaneously measured leaf gas exchange with spatially explicit chlorophyll-a fluorescence and leaf temperature to examine the effects of cutting a primary leaf vein in Helianthus annuus. W...

A semianalytical solution is presented for transient streaming potentials associated with flow to a pumping well in an unconfined aquifer, taking into account the effect of flow in the unsaturated zone above the water table. Flow in the unsaturated zone is modeled with a linearized form of Richards’ equation using an exponential model for soil moisture retention and unsaturated hydraulic conduc...

In this paper, the cell-centered finite volume method (CC-FVM) has been presented to simulate the axisymmetric radial flow toward a pumping well. The model is applied to the unstructured triangular grids which allows to simulate inhomogeneous and complex-shaped domains. Due to the non-orthogonality of the irregular grids, the multipoint flux approximation (MPFA) methods are used to discretize t...