This study aims to investigate the use of an industrial residue rich in silica and aluminum, generated during the production of fluid catalytic cracking (FCC) catalysts, as a precursor in the synthesis of geopolymers. The research seeks to mitigate environmental impacts associated with both the inadequate dispôs al of industrial residues and the high energy consumption and CO₂ emissions related to Portland cement production. The methodology involves the physicochemical characterization of the residue using advanced analytical techniques, the definition of synthesis parameters for geopolymer production, the evaluation of paste rheology, and the determination of mechanical properties of the specimens. Preliminary results indicate that the residue has significant potential as a geopolymer precursor, mainly due to its high silica and aluminum content. Furthermore, processing tests demonstrated compatibility with the requirements, ensuring proper deposition and satisfactory early mechanical strength. Therefore, this study proposes an innovative route for industrial waste valorization while providing a sustainable alternative to conventional construction materials, aligned with circular economic principles and global decarbonization goals

To evaluate how infection by Angiostrongylus cantonensis and Echinostoma paraensei affects the biomineralization of the shells of the mollusks Bulimulus tenuissimus and Biomphalaria glabrata. Techniques such as XRD, FTIR, Raman spectroscopy, and computational analysis were used to identify structural and crystallographic alterations in the material. The results show that parasitism alters the composition, crystallite size, and microstrains, influencing the characteristics of the material.

Additive manufacturing, especially 3D printing by Fused Deposition Modeling (FDM), has emerged as a promising technology for the production of functional components due to its versatility, low cost, and ability to fabricate complex geometries. However, commercial polymer filaments present limitations regarding electrical conductivity, restricting their use in electrochemical applications. In this context, this work aims to develop and characterize conductive filaments based on PLA, castor oil, and graphite, synthesized through chemical and physical routes, targeting their application as 3D-printed electrodes for dopamine detection. For this purpose, the composites were prepared by solvent-based and thermo-shear mixing methods, subsequently extruded into 1.75 mm filaments, and processed in a 3D printer. The materials obtained were characterized using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), thermal analyses (TGA and DSC), dynamic mechanical analysis (DMA), and electrochemical tests by cyclic voltammetry. Preliminary results indicated that the filaments showed good dimensional uniformity, mechanical flexibility attributed to castor oil, and stable printing without fractures, in addition to adequate graphite dispersion in the polymeric matrix. As future steps, the evaluation of electrical properties and electrochemical performance of the electrodes will be deepened, especially in dopamine detection at different concentrations, aiming to demonstrate the feasibility of the proposed formulation for sustainable and low-cost sensor applications.

The growing generation of Construction and Demolition Waste (CDW), estimated at 44 million tons in Brazil in 2023, represents a significant environmental challenge but also an opportunity for sustainability. Aligned with the UN Sustainable Development Goals (SDGs), especially SDG 11 (sustainable cities and communities), this dissertation investigates the technical and environmental feasibility of producing cement-based boards with the incorporation of CDW. The research aims to contribute to reducing the sector's environmental impact, preserving natural resources, and promoting the circular economy. Although the civil construction sector is a global economic driver, contributing significantly to the Gross Domestic Product (GDP) and job creation, it is also one of the largest generators of urban solid waste. In Brazil, despite the considerable installed capacity for CDW recycling, the effective production of recycled aggregates is consistently lower, indicating the need for optimization in the management and processing of these materials.The use of recycled aggregates in cementitious materials, while promising, presents challenges. The performance of recycled concrete aggregate (RCA) is often inferior to that of natural aggregate, which can result in lower mechanical strength, higher water absorption, and greater drying shrinkage in mortars and concretes.Given this scenario, this research proposes the fabrication of cement-based boards incorporating different contents of CDW. The methodology includes the characterization of the waste (chemical, physical, and micrographic analyses, such as X-ray Fluorescence, X-ray Diffraction, particle size analysis, specific gravity, void ratio, and moisture content), Portland cement type CPII, and natural sand. Mortar mixtures will be developed with 0%, 25%, and 75% substitution of conventional fine aggregate (sand) with CDW, adjusting the water/cement ratio to ensure workability.The produced cement-based boards will be subjected to fresh state tests, such as consistency index, and hardened state tests, such as compressive strength and permeability by capillarity. The expectation is to develop mortars using CDW in the composition to produce cement-based boards with characteristics similar or superior to commercial products.The project has a technological focus by developing an innovative and more sustainable product, providing data for its industrial production; an environmental focus, by reducing the amount of debris in landfills and decreasing the demand for virgin raw materials; and an economic focus, by potentially lowering production costs and fostering innovation in the construction industry. This study is expected to contribute significantly to the advancement of civil construction towards sustainability.