Sodium alginate (SA), a linear polysaccharide which is present in different forms, is commonly used for tissue engineering. One of the main challenges of using SA in tissue engineering consists of the fabrication of nanoparticles/nanofibres for cell culture scaffolds. Because SA has been developed for medical purposes, it is necessary to measure, among others, the electrochemical properties because they provide information of biological activity related to metabolic behaviour. This work focuses on the measurement, interpretation, and characterization of electrochemical properties by means of electrochemical impedance spectroscopy of SA electrospun fibres mixed with poly(vinyl alcohol) (PVA) at different PVA/SA concentration ratios (3.5, 4, and 5 wt.%). To stabilize the PVA/SA systems, a calcium chloride solution was used for the cross‐linking process. The electrochemical impedance spectroscopy results show that PVA/SA nanofibres immersed in calcium chloride react instantly and the dielectric properties of the PVA/SA system change until the cross‐linking process is stabilized in time. The overall cross‐linking time depends on the PVA/SA ratio which means, the more SA concentration mixed in PVA solution, the shorter the cross‐linking time needed for a stabilization plateau. The 5 wt.%, PVA/SA gives not only the highest impedance values after cross‐linking treatment, but also the more constant and reproducible electrochemical features in time, in conjunction with a more homogeneous, compact and low porous nanofibre.

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Very commonly, a mechanical workpiece manufactured industrially includes more than one machining operation. Even more, it is a common activity of programmers, who make a decision in this regard every time a milling and drilling operation is performed. This research is focused on better understanding the power behavior for face milling and drilling manufacturing operations, and the methodology followed was the design of experiments (DOEs) with the cutting parameters set in combination with toolpath evaluation available in commercial software, having as main goal to get a predictive power equation validated in two ways, linear or nonlinear, and understanding the energy consumption and the quality surface in face milling and final diameter in drilling. The results show that it is possible to find difference in a power demand of 1.52 kW to 3.9 kW in the same workpiece, depending on the operations (face milling or drilling), cutting parameters, and toolpath chosen. Additionally, the equations modelled showed acceptable values to predict the power, with p values higher than 0.05 which is the significance level for the nonlinear and linear equations with an R square predictive of 98.36. Some conclusions established that optimization of the cutting parameters combined with toolpath strategies can represent an energy consumption optimization higher than 0.21% and the importance to try to find an energy consumption balance when a workpiece has different milling operations.

This work focuses on the development of a novel hydrophobic process for anodized aluminum AA2024‐T3 which consists of a combination of corrosion inhibitors: sodium metavanadate with a γ‐irradiated fluoropolymer. The anodizing films, formed in sulfuric acid media, were sealed by using different aqueous solutions such as boiling water, potassium dichromate, and cerium nitrate. The corrosion resistance results obtained by electrochemical impedance spectroscopy (EIS) showed that samples sealed with Ce(NO3)3 had a higher average value of total impedance of 1011 Ω cm2 obtained at low frequencies in 0.1 M NaCl solution. Water contact angle measurements revealed best results at 128.8°. X‐ray photoelectron microscopy in conjunction with scanning electron microscopy indicated the formation of a layer of fluoro compound above the anodized aluminum. X‐ray diffraction, infrared spectroscopy, and differential scanning calorimetry demonstrated thermal modifications of the γ‐irradiated fluoropolymer.