Microplastic occurrence and distribution in the Gulf of Guayaquil, Ecuador.

Microplastics (MPs) were assessed in water and sediment samples along the Salado Estuary, an estuarine system composed of a complex river drainage network in Guayas, Ecuador. MPs were quantified and categorized according to shape, size, and composition. Pellet morphology (237,490 MP/L) and transparent color MPs (252,990 MP/L) were the most common in water, while fragments (27,330 MP/m) and silver color MPs (25,310 MP/kg) were the most common in solid samples (river sediments, mangrove mud, and sand).

Wave propagation in sandwich panels with a poroelastic core.

Wave propagation in sandwich panels with a poroelastic core, which is modeled by Biot's theory, is investigated using the waveguide finite element method. A waveguide poroelastic element is developed based on a displacement-pressure weak form. The dispersion curves of the sandwich panel are first identified as propagating or evanescent waves by varying the damping in the panel, and wave characteristics are analyzed by examining their motions.