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...

We develop a numerical algorithm to simulate nuclear magnetic resonance (NMR) measurements in the presence of constant magnetic field gradients. The algorithm is based on Monte Carlo conditional random walks in restricted and unrestricted space. Simulations can be performed of threedimensional (3D) porous media that include both arbitrary bimodal pore distributions and multi-phase fluid saturat...

sures experienced by a pipeline can be either beneficial or detrimental from an operational performance perspective, depending on the amount, the two phase regime of the mixture (whether homogeneous or slug) and the nature and cause of the transient. It is generally held that when free (undissolved) air, or gas, is present in a hydraulic system, it can greatly reduce the surge pressure levels b...

As plant tissues dehydrate, water transport efficiency declines, a process typically attributed to air obstruction (embolism) in the xylem. Trifiló et al. (pages 5029– 5039) dissect leaf hydraulic vulnerability and show that both xylem and living tissues may be important. If confirmed and clarified, an important role for outside-xylem hydraulic decline will change our understanding of how plant...

drain envelopes play significant roles in the performance of drainage systems due to theirreduction in letting sediments into the drainpipes and also because of an increase in thehydraulic conductivity of soil around the drainpipes. throughout the present research, theeffect of a one 1000 hour flow on dual envelopes consisting of geotextile as a means ofimproving the hydraulic gradient and rice...

Nowadays, hydropower plays an essential role in the energy market. Due to their fast response and regulation capacity, hydraulic turbines operate at off-design conditions with a high number of starts and stops. In this situation, dynamic loads and stresses over the structure are high, registering some failures over time, especially in the runner. Therefore, it is important to know the dynamic r...

Quantitative changes in groundwater and crises resulting from uncontrolled water extraction have turned water resources management into one of the supply-demand dilemmas in arid regions. The present study evaluated the quantitative situation of water resources in the Ardestan Plain adjoining the Ardestan desert by using the MODFLOW mathematical model. Simulation of groundwater flow in the stead...

Accurate haemodynamic assessment of mitral stenosis by hydraulic formulas requires measurement of the mean valve gradient and the cardiac output. The calculation is laborious, particularly in the presence of atrial fibrillation when averaged values obtained from multiple beat-to-beat determinations must be used. The relations between valve area, end diastolic gradient, and heart rate in 20 pati...

Hydraulic conductivity of the xylem is computed as the quotient of mass fiow rate and pressure gradient. Measurements on excised plant stems can be difficult to interpret because of timedependent reductions in fiow rate, and because of variable degrees of embolism. Using Acer saccharum Marsh, stems, we found that certain perfusing solutions including dilute fixatives (e.g. 0.05% formaldehyde) a...

Intensified droughts are affecting tropical forests across the globe. However, underlying mechanisms of tree drought response and mortality poorly understood. Hydraulic traits especially hydraulic safety margins (HSMs), that is, extent to which plants buffer themselves from thresholds water stress, provide insights into species-specific vulnerability. We investigated during an intense triggered...