labyrinth spillway is an appropriate option to pass pmf discharge. the most advantages of this type of spillway are higher discharge capacity, easy aeration as well as low fluctuations of flow surface. it is essential to find the optimum geometry considering the maximum passing discharge under specific hydraulic conditions with minimum construction cost. in this study, fuzzy inference system (f...

This paper studies the motion control of single-rod hydraulic actuators regulated by proportional directional control(PDC) valves with deadband and nonlinear flow gains. The boom motion control of a hydraulic robot arm driven by a singlerod hydraulic actuator is used as a case study. The experimental system dynamics are highly nonlinear. In addition, the system has large extent of modeling unce...

In this paper, configurations of pre-existing fractures in cubic rock blocks were investigated and reconstructed for the modeling of experimental hydraulic fracturing. The fluid-rock coupling process of hydraulic fracturing was simulated based on the displacement discontinuities method. The numerical model was validated against the related laboratory experiments. The stimulated fracture configu...

In the case of straight flow but with hydraulic conductivity varying in a transverse direction, the distribution of hydraulic conductivity has been determined for which the breakthrough curve due to convection only will have the same analytical form as the onedimensional convection/dispersion equation solution at the outlet end of a porous medium. That distribution is found exactly and it is ve...

The Wells G and H Superfund site, located in the Aberjona watershed in Woburn, Massachusetts, has been studied by a number of MIT research groups since 1987. Initial research conducted to characterize the hydraulic properties of the wetland deposits, did not indicate the classical trend linking changes in hydraulic conductivity to changes in total porosity. It was hypothesized, therefore, that ...

Plasma lipoproteins are thought to transport cholesterol, vitamins and carotenoids to the retinal pigment epithelium (RPE) for ultimate use by the photoreceptors. However, to reach the RPE, these lipoprotein particles must cross Bruch's membrane. We examined the reflection coefficient of Bruch's membrane (BrM) to low-density lipoprotein (LDL). Bruch's membrane and choroid were removed from 47 b...

throughout history dams have been important structures in water storage. to avoid overtopping, damage, and or failure of a dam, adequate spillway is needed to release excess water from upstream floods. researchers found that spillways have to be made nonlinear in order to reach an economic structure with high performance. a piano key weir is one of the best solutions. piano key weirs are the mo...

a down-flow hanging sponge (dhs) reactor has been developed for sewage treatment, mainly in developing countries. this novel reactor employs polyurethane sponge material as a support medium, which promises a proliferation of a large amount of biomass, offering excellent pollutant removal capability. three types of sponge medium were evaluated with respect to water distribution and oxygen mass t...

Vegetation resistance influences water flow in floodplains. Characterization of vegetation for hydraulic modeling includes the description of the spatial variability of vegetation type, height and density. In this research, we explored the use of dual polarized Radarsat-2 wide swath mode backscatter coefficients (σ°) and Landsat 5 TM to derive spatial hydraulic roughness. The spatial roughness ...