OBJECTIVES Leaflet injury has been documented to occur during the deployment of valved stents (VSs). The pathological aspects, however, of this injury are difficult to quantify. Conversely, the hydraulic conductance of a (pericardial) membrane may be easily determined. The impact of crimping and deployment of VS on this parameter was therefore investigated. METHODS Bovine pericardial square (...

Experimentally determined values of unsaturated soil hydraulic conductivity are presented for an Alfisol of the county of Piracicaba, S.P., Brazil. Simultaneous measurements of soil water content and pressure head are made along a 125 m transect within an irrigated field during the internal drainage process. Calculations of the soil hydraulic conductivity were made using the instantaneous profi...

Three measurements of head at unique locations form a three-point estimator of the local magnitude and orientation of the hydraulic gradient. The relative head measurement error (RHME) is defined here as the measurement error normalized by the head drop across the three-point estimator. Monte Carlo simulation results show that estimators with base to height ratios between 0.5 and 5.0 and that a...

The Afghanistan population living far from rivers relies upon groundwater delivered from karezes (sub-horizontal tunnels). Karezes exploit unconfined groundwater in alluvial fans recharged largely by snowmelt from the Hindu Kush, the central mountain range of the country. Since the multi-year drought that began in 1998, many karezes have stopped flowing. This study characterizes the hydraulics ...

thermo-elasto-plastic analyses of thick-walled spherical tanks made of functionally graded materials are investigated analytically. these tanks are subjected to positive or negative temperature gradient and internal pressure loadings separately or simultaneously. the power law modeling has been used for through-the-thickness variation of mechanical properties. von mises yield criterion and elas...

The goal of a hydraulic capture model for remediation purposes is to design a well field so that the direction of groundwater flow is altered, thereby halting or reversing the migration of a contaminant plume. Management strategies typically require a well design that will contain or shrink a plume at minimum cost. Objective functions and constraints can be nonlinear, non-convex, non-differenti...