In geotechnical structures, the permeability-dependent stability analysis is generally evaluated under vertical trajectories, because most permeameters are configured so that the water passes through the porous medium in this way. However, it is clear from the physical point of view that water can flow along different paths, including preferential ways that can include horizontal trajectories, parallel to the deposit of the stratum. The foregoing implies that both the vertical and horizontal component of the hydraulicconductivity or permeability coefficient must be estimated for a given stratum. The current research aims to explore possibilities for measuring the coefficient of permeability in horizontal trajectories, on granular soils, under a constant condition of relative density. For this purpose, a special chamber attached to a constant head permeameter was designed and constructed, which allows to measure the permeability in conditions of horizontal flow parallel to the soil layers. The proposed camera also admits the estimation of the permeability coefficient by combining stratifications of different granular soils, where the trajectories are not perfectly horizontal, but have diagonal paths. The results are compared with data obtained by conventional vertical flow permeameters, in order to check the difference in the measurements considering both situations in the samples. As a conclusion, it is important to report that there is evidently a difference in the permeability coefficients measured under different trajectories
On the type and the most suitable mathematical representation of the examined parameters scaling laws it was already discussed in previous studies [33,35]. Specifically, Fallico et al. (2016)  proposed a not homogeneous power law model, to investigate the possible dependence upon more than a scale. These authors clarified also that a simple (homogeneous) power law model can be adopted for large values of the scale parameter, while for small values of this the inhomogeneous power law model should be used, in agreement with the concept of representative elementary volume . Therefore, the purpose of this study consists in verifying whether the results obtained using scaling laws valid only for individual ranges of interest are more or less reliable than those obtained by the use of a single multiple scaling law, valid for the whole aquifer. For this purpose, the porous confined aquifer of Montalto Uffugo (Italy) test field was considered and several sets of hydraulicconductivity (k) and effective porosity (n e ) values, obtained by several different laboratory and field measurement methods, were used. Based on that, the experimental scaling laws of k = k (s) and n e = n e (s) were determined, where s is the scale, relating primarily to the field and the total or multiple experimental scales and comparisons between this last and the first were performed.
Hydrogeological, statistical and graphical approaches have shown that Al Ramtha wastewater treatment plant (RWWTP) is the major source of groundwater contamina- tion in the Al Ramtha area, northern Jordan. High levels of nitrate were found in those wells located in close proximity of the treatment plant with more than 50% of the studied samples having concentration above the maximum per- missible limit of WHO drinking water quality standards (50 mg/L). Depth to groundwater, hydraulicconductivity, distance from the plant, and lineaments density dictate the aquifer’s vulnerability to contamination. Hydrochemical analysis has revealed that groundwater in the study area has a fresh-brackish, and hard to very hard composition. Groundwater chemistry has evolved from Ca-HCO 3 fresh
We took two complementary approaches to compare physiological responses for temperate species which suffer distinct seasonal extremes during summer and winter. First, we conducted a detailed meta-analysis of several key plant functional variables - stomatal conductance (g s ), percent loss of hydraulicconductivity (PLC) and/or photoinhibition, indicated by low photochemical efficiency of photosystem II (F v /F m ) - in summer versus winter for three functional types of woody species (winter deciduous angiosperms, evergreen angiosperms and conifers) from sites with and without summer droughts across the temperate zone. Second, because the meta-analysis approach can be misleading due to pooling data for average patterns across species growing under disparate conditions and measured with varying techniques, we tested whether the findings of the global meta-analysis were supported in a case study of Mediterranean species in a drought-prone site in continental central Spain. Both sets of data allowed additional testing of the hypothesis that stomatal dynamics reflects the status of the hydraulic system (Sperry, 2000). Several empirical and theoretical studies have shown that stomatal closure tends to reflect loss of hydraulic function (Sperry, 2000; Meinzer et al., 2008; Johnson et al., 2011), both diurnally during the growing season and seasonally during ongoing water stress, though this has not been investigated to our knowledge across diverse species and communities.
Flow in heterogeneous media is qualitative and quantitatively different from flow in homoge- neous media [Indelman and Rubin, 1996; Noetinger, B.Estebenet and Quintard, 2001; Keller, 2001]. The systematic investigation of the impact of spatial heterogeneity on the effective behavior of flow can be addressed by two interrelated strategies, which can be called coefficients ap- proach and dynamic approach. The coefficient approach quantifies flow in terms of effective coefficients such as effective hydraulic coefficients to insert in the classical flow equation. Ef- fective hydraulicconductivity is commonly requested by numerical models, widely used in groundwater management, as single effective parameter to consider in the flow equation and model flow in any d dimensional heterogeneous media. The dynamics approach deals with the up-scaling of the local scale equation in heterogeneous media. Stochastic average provides a systematic way to quantify the impact of heterogeneity on flow through heterogeneous me- dia and the derived effective equation is linked to a statistical description of heterogeneity. In this chapter we use stochastic methods to determine effective flow coefficient and to ob- tain an effective upscaled equation for flow in heterogeneous media characterized by spatially varying hydraulicconductivity. Within a stochastic approach, a spatially varying hydraulicconductivity in a heterogeneous medium is assumed to be one realization chosen from an ensemble of conductivity fields. Here we model variable hydraulicconductivity as random function and the mean behaviour for the hydraulic head, also modeled as a random function, is obtained considering ensemble average. Starting from a local problem we derive effective equation that is non local both in time and in space. Non locality implies that a description of flow in heterogeneous media in terms of effective coefficient could be not enough to catch
Fishways are structures that aim to achieve the free movement of fish through transversal obstacles in rivers. Despite the wide research about their performance, their hydraulic study and characterization has been so far limited to uniform hydraulic conditions which are usually difficult to reach in natural scenarios, either because inaccurate building or simply because the studied situations during the design of the prototypes are never encountered. This study aims to model pool-type fishways with submerged notches and orifices under different regimes, and uniform and non-uniform performances. For this purpose, the classical formulation used in their design has been modified by studying a real-scale fishway under 29 different boundary conditions. The proposed new formulation together with a logical bottom- up iterative calculation is able to predict the observed water level distributions. This study demonstrates that orifices and notches can be considered independently when estimating the water level distribution and discharge through the fishway, and the need to modify the classical formulation. The modelling under non-uniform water level profiles will allow to enhance and adapt fishways to achieve a greater fish passage during longer time periods. Keywords: Pool-weir fishways; Water levels; Flow discharges; Hydraulic design; Non-uniform performance
Similarly to the first case, for the double-actuator model, reference signals for the direc- tional valves of the hydraulic circuits are produced with a joystick. Figure 14 shows the resultant actuator lengths obtained with a monolithic simulation of 1 ms step-size. Although the system still seems fairly simple, the addition of the second hydraulic circuit as a new subsystem introduces an indirect coupling between the cylinders via the mechanical sys- tem, which from the co-simulation point of view, is significantly more challenging than the single-actuator case. The problem is solved again with the Jacobi-scheme co-simulation with different coupling strategies, as described before. To limit the number of considered variables, the same settings are used for both hydraulic subsystems.
(x=15−16), were synthesized. Three-dimensional open frameworks resulted from the linkage of similar organo-inorganic layers, in the ac- plane, by central lanthanide ions, which yield trimeric units also found in other metal-HPAA compounds (Figure 1.5). Ln-HPAA networks enclose water-filled 1D channels and undergo remarkable crystalline- to-amorphous-to-crystalline transformations upon dehydration and rehydration cycles (Colodrero et al., 2012c). Both polymorphic forms showed proton conductivity at room temperature, with a gadolinium polymorph being highest proton conductor, while a europium derivative exhibited the best photo-luminescent properties, which are strongly dependent on dehydration-rehydration processes (Colodrero et al., 2012c).
La Empresa “Hydraulic and Environmental Design S.A.S.”, es una empresa de ingeniería fundada el 17 de abril del año 2009 en la Ciudad de Bogotá. Está dedicada a la ejecución de estudios y diseños de ingeniería sanitaria y ambiental para entidades públicas y privadas; desarrolla actualmente proyectos para sectores industriales, manejo de recurso hídrico, urbanismo, vial, edificaciones, Oil & gas y energía. La importancia de la formulación y ejecución de proyectos de inversión pública y privada en Colombia, ha permitido que empresas de este tipo, logren una ubicación con experiencia dentro del mercado. Sin embargo, para que sean competitivas y sigan creciendo, deben poseer un direccionamiento estratégico estructurado y claro, en donde la identidad y estrategias conocidas por toda la organización, permitan llegar a los objetivos deseados.
La producción del campo Coca, declina su producción debido al cambio de la presión de fondo lo que produce un sobre dimensionamiento de la bomba jet como causa principal, presencia de escala por el alto contenido de agua que producen los pozos, taponamiento por corrosión de la tubería de inyección los mismos que son el causal del daño en el estado mecánico de bomba. Por este motivo se dará una recomendación para el cambio de geometría de la bomba jet mediante el programa Oil Well Hydraulic.
repressed, fired at 1250 °C for 6 hours, ground, pressed isostatically at 200 MPa, given a final firing at 1400 °C for 12h in air and then cooled slowly by switching off the furnace. We avoided the use of ball milling systems and media to mix samples since these are prone to the introduction of contaminants; all samples were, instead, hand-mixed and milled using an agate mortar and pestle. Using our normal procedures (10-15 min mixing, with acetone added periodically to form a paste), typical pellet densities after firing sol-gel derived samples were ~82%, Table I. Given the necessity to demonstrate that the results presented here were not, in some way, influenced by ceramic porosity, samples prepared by the solid state route used more extended hand-milling times (~1h) and in this way, pellets with densities as high as 98% were achieved, Table I. The electrical conductivity results, especially field-dependent conductivities, were found to be similar for samples of a given composition for pellets densities in the range ~82 to 98%, indicating that the electrical properties were essentially uninfluenced by ceramic porosity.
El Capítulo 2 presenta el primer paper titulado: On a RUSLE-based methodology to estimate hydraulic erosion rates at country scale in developing countries, que plantea una metodología para estimar la erosión de suelos a escala nacional ante un contexto de escases de información básica como ocurre en los países en desarrollo. Tiene como producto mapas de la tasa de erosión de suelos en el Perú para los años 1990, 2000 y 2010 a una resolución de 5km.
Abstract—Futaleufú hydropower plant has 4 Francis turbines rated 118 MW and it is connected to the power system by 2x330 kV lines. Studies carried out in the past did not predict the instable operation of Futaleufú after a 330 kV line fault, when some Futaleufú turbines are automatically disconnected as a consequence of the faulted line tripping. Load rejection caused by disconnected turbines generate large transients in the remaining turbines due to hydraulic coupling through the common conduits. Then, to improve related models and, therefore, to improve studies results of such a line fault it was necessary to make several tests in Futaleufú power plant. Finally, these models were used to conduct studies to design a new automatism, like the gate partial closing of the remaining turbines, to obtain a dynamically stable operation of Futaleufú after the disconnection by fault of a line of 330 kilovolts.
19. (measuring) the pH / the strong acid solution will have a lower pH; conductivity (measurement) / the strong acid will be a better conductor; the strong acid will react more vigorously with metals/carbonates / the reaction with metals/carbonates;