Making use of concrete materials in cut-off walls, because of their low permeability and standing high Hydraulic Gradient caused by underground drainage, has attracted great amount of attention. Using ordinary concrete with high elasticity modulus, compared to other materials may accompany with problems including brittleness of cutoffs due to dynamic stresses. To solve this problem, adding a ce...

this paper deals with failure prognostic in dynamic systems. The system’s remaining useful life is estimated based on residual signals. This supposes the possibility to build a dynamic model of the system by using the bond graph tool, and the existence of a degradation model in order to predict its future health state. The choice of bond graph is motivated by the fact that it is well suited for...

Research in plant hydraulics has provided important insights into plant responses to drought and species absolute drought tolerance. However, our ability to predict when plants will die from hydraulic failure under extreme drought is limited by a lack of knowledge with regards to the dynamics of plant desiccation following stomatal closure. Thus, we develop a simple hydraulics model based on br...

Fractured-rock aquifers display spatially and temporally variable hydraulic conductivity generally attributed to variable fracture intensity and connectivity. Empirical evidence suggests fracture aperture and hydraulic conductivity are sensitive to in situ stress. This study investigates the sensitivity of fractured-rock hydraulic conductivity, groundwater flow paths, and advectiondominated tra...

In the reliability centered maintenance (RCM) methodology, the reliability estimates of the system are used to provide a cost-effective & satisfactory maintenance schedule. In this paper, a new framework for improvement of the RCM procedure based on the failure mode and effect analysis (FMEA) is developed. In order to achieve the objective, first based on the OREDA handbook classification the c...

The hemodynamic evaluation of the pulmonary circulation normally includes the measurements of mean pulmonary artery pressure and a calculation of pulmonary vascular resistance (PVR). The definition of PVR can be improved by the measurements of pulmonary vascular pressures at several levels of flow to derive a pressure-flow line, and the site of PVR can be identified by the analysis of pulmonary...

Numerical simulation is very useful for understanding the hydraulic fracturing mechanism. In this paper, we simulate the hydraulic fracturing using the distinct element approach, to investigate the effect of some critical parameters on hydraulic fracturing characteristics. The breakdown pressure obtained by the distinct element approach is consistent with the analytical solution. This indicates...

In this paper the control problem of a hydraulic servo-system is addressed. The performance achievable by classical linear controllers, e.g. PD, are usually limited due to highly nonlinear behavior of the hydraulic dynamics. This paper adopts the backstepping design strategy to develop a Lyapunov-based nonlinear controller for a hydraulic servo-system. Load, hydraulic and valve dynamics are inc...

Recently, a benchmarking test study of several hydraulic river models has been undertaken by the authors ^. One of the tests being investigated was the performance of hydraulic river models in using measured and interpolated crosssections for unsteady flows. Details of the interpolation algorithm for obtaining interpolated cross-sections are described in the paper. It is shown that the appropri...

Hydraulic bending roll system has become one of key equipments to control the exit strip shape in strip rolling mills. The hydraulic bending roll system of a hot rolling mill was researched and analyzed, and its mathematics models were founded in whole based on the action principle of some representative hydraulic components. At last, the hydraulic bending roll system was simulated with MATLAB ...