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The reuse of waste in civil construction brings environmental and economic benefits. However, for these to be used in concrete, it is necessary a previous evaluation of their physical and chemical characteristics. Thus, this study aimed to characterize and analyze the waste foundry exhaust sand (WFES) for use in self-compacting concrete (SCC). Foundry exhaust sand originates from the manufacturing process of sand molds and during demolding of metal parts. It is a fine sand rich in silica in the form of quartz collected by baghouse filter. Characterization of WFES was conducted through laser granulometry, scanning electron microscopy (SEM) in the energy dispersive spectroscopy (EDS) mode, X-ray diffraction (XRD), X-ray fluorescence (XRF), Fourier transform infrared spectroscopy (FTIR), thermogravimetry (TG) and derivative thermogravimetry (DTG) techniques. The waste was classified as non-hazardous and non-inert, with physical and chemical properties suitable for use in SCC composition, as fine aggregate or mineral addition. Five mixtures of SCC were developed, in order to determine the waste influence in both fresh and hardened concrete. The properties in the fresh state were reached. There was an increase in compressive strength and sulfate resistance, a decrease in water absorption of self-compacting concrete by incorporating WFES as 30% replacement. [ABSTRACT FROM AUTHOR]

The current metallic biomaterial still presents failures associated with the bulk alloy and the interface of material/human body. In previous studies, titanium alloy with tantalum showed the elastic modulus decrease in comparison with that of commercially pure (cp) titanium. In this study, surface modification on Ti-30Ta alloy was investigated. Titanium and tantalum were melted, homogenized, cold-worked by a rotary swaging process and solubilized. The anodization process was performed in electrolyte contained glycerol + NH4F 0.25% at 30 V using seven different durations—4 h, 5 h, 6 h, 7 h, 8 h, 9 h, and 10 h and annealed at 530 °C for 1 h. The surface topography was characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM) measurements, X-ray diffraction analysis (XRD), and contact angle. From the results, we conclude the time of anodization process influences the shape and morphology of the anodized layer. The 5 h-anodization process produced a smooth and porous surface. The 4-, 6-, 7-, 8-, 9-, and 10-h conditions showed nanotubes morphology. All surfaces are hydrophilic (<90°). Likewise, all the investigated conditions present anatase phase. So, this surface modification presents potential for biomedical application. However, more work needs to be done to better understand the influence of time on the anodization process. [ABSTRACT FROM AUTHOR]