This study presents the effect of spray‐coated graphene nanoplatelets on the mechanical response of various polymers to cyclic loadings. The substrates material (three polymers) and the coating (various numbers of coating layers) are assessed. The experimental results suggest that the compressive stiffness, compressive modulus, damping, and energy dissipation of the samples coated with graphene nanoplatelets improve with respect to the uncoated samples. The outcomes of this experimental research highlight the feasibility of utilizing films of graphene nanoplatelets to improve the mechanical properties of polymers for vibration isolation, foreseeing application in various environments, for instance, in buildings and infrastructures (bridges, railways) for seismic and acoustic isolation.

Oil palm empty fruit bunch fibers (OPEFBF), in three size ranges (small: 250–450 µm, medium: 450–600 µm, large: 600–800 µm), were investigated as a filter-bed material in biofilters for the removal of organic matter and nutrients. After saturation, these fibers (post) were used in the removal of methylene blue through batch processes. The batch adsorption tests included optimizing the adsorbent dosage (0.5–32.0 g/L) and contact time (2.5–60.0 min). Experimental data were fitted to various kinetic/isotherm models. Instrumental characterization of both raw and post fibers was conducted. Post fibers underwent morphological/compositional changes due to the presence of microorganisms and their byproducts. Efficiencies reached up to 94% for chemical oxygen demand (COD), 88.4% for total nitrogen and 77.2% for total phosphorus. In batch adsorption, methylene blue removal exceeded 90%, underscoring the effectiveness of small raw OPEFBF and large post OPEFBF. Kinetic models indicated that raw OPEFBF better fit the pseudo-first-order model, while post OPEFBF better fit the pseudo-second-order model. Both types of OPEFBF showed a good fit with the Freundlich model (higher R2, lower χ2 and SSE). Particularly, large post OPEFBF stood out as the most efficient adsorbent, achieving a maximum adsorption capacity of 12.02 mg/g for methylene blue. Therefore, raw/post OPEFBF could be an alternative to remove contaminants from wastewater.

El estudio del material granular almacenado en silos se lo ha realizado habitualmente con las formulaciones de la mecánica del medio continuo y los elementos finitos. Sin embargo, existen diversas limitaciones al cuantificar la interacción entre partículas y su comportamiento individual. Por lo tanto, se plantea la utilización del método del elemento discreto (DEM) para evitar las limitaciones intrínsecas de modelos continuos en el análisis del flujo de maíz (materia granular) durante los procesos de descarga en silos. El elemento discreto es una eficaz herramienta mecánico-computacional que permite modelar ensambles granulares al considerar sus propiedades físicas y mecánicas tanto al nivel individual como de conglomerado. En esta investigación, los ensambles diseñados son representaciones numéricas de granos de maíz almacenado en silos. Los resultados de las simulaciones se cuantifican en términos de perfiles de velocidad, cadenas de fuerza, esfuerzos en las paredes del silo, y deformaciones del conglomerado granular. Uno de los principales hallazgos de esta investigación es la importancia del ángulo de reposo del maíz en la descarga de silos ya que los esfuerzos, deformaciones y cadenas de fuerza varían dependiendo de este valor (27°).