Publications by authors named "Casamitjana X"

A comprehensive hydrogeological report was conducted to determine the origin, occurrence and processes affecting nitrogen in a Mediterranean coastal aquifer-lagoon system. Water levels, hydrochemical and isotopic data was gathered during a 4-year period in the La Pletera salt marsh area (NE Spain). They were collected from the alluvial aquifer, two natural lagoons and four other permanent lagoons excavated during a restoration process (in 2002 and 2016), two watercourses (the Ter River and the Ter Vell artificial channel), 21 wells (considering six of them for groundwater sampling) and the Mediterranean Sea.

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Coastal lagoons can act as sinks and sources of a wide range of substances, including nutrients, and pollutants. In these ecosystems, primary production is limited more by nitrogen than by phosphorus. For this reason, they are significantly vulnerable to nitrate pollution.

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This dataset is related to the research article entitled "Effects of morphology and sediment permeability on coastal lagoons' hydrological patterns" (W. Meredith, X. Casamitjana, X.

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The systematic creation of gaps within canopies results in fragmentation and the architecture of fragmented canopies differs substantially from non-fragmented canopies. Canopy fragmentation leads to spatial heterogeneity in hydrodynamics and therefore heterogeneity in the sheltering of canopy communities. Identifying the level of instability due to canopy fragmentation is important for canopies in coastal areas impacted by human activities and indeed, climate change.

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A great challenge in water reuse is the reduction of suspended particle concentration in wastewater. In particular the reduction of the presence of small particles in suspension which cause a cloudy appearance in the water and, which also make disinfection difficult. The present study evaluates the filtering capacity of a population of Cladodera (Daphnia magna) in secondary effluents from a wastewater plant.

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The dynamics of the particle boundary layer in the Boadella reservoir was studied using an in situ laser optical particle-sizing instrument. This layer was found at the bottom of the reservoir from summer until the end of the year, when the reservoir was fully mixed. Most of the particles in this layer are remnants of the summer algae bloom and are trapped in the boundary layer due to the thermal stratification.

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Measurements of the suspended particle concentration in a lake demonstrate the presence of a turbid hydrothermal plume. The plume, generated from a warm source develops upward carrying a suspension of particles from the bottom. It is found that the vertical structure of the plume depends on the stratification of the water column, which in turn depends on the seasonal meteorological conditions.

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A particle size analyzer together with a video camera has been used to investigate the structure of the aggregates during the process of aggregation and breakup of particles in a shear flow induced by means of a Couette-flow system. Three different values for the shear rate have been used (25, 32, and 50 s-1). The initial volume fraction of the particles was phi0 = 5.

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An experimental study was carried out to investigate aggregation and breakup of particles in a Couette flow system with the inner cylinder rotating at constant speed. Experiments were conducted with monodisperse and polydisperse suspensions at different particle volume concentrations. Depending on both the shear stress and the particle concentration, three different regimes were found.

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