Navegando por Autor "Oliveira, Fernando R."
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Artigo Development of porous alumina membranes for treatment of textile effluent(Taylor & Francis, 2015-02-27) Silva, Késia Karina de Oliveira Souto; Paskocimas, Carlos Alberto; Oliveira, Fernando R.; Nascimento, José Heriberto Oliveira do; Zille, AndreaCeramic porous membranes sintered at two different temperature using polyvinyl alcohol and ethylene glycol as binders, and composed of two types of α-alumina with different parti- cle sizes were investigated for the microfiltration of a textile effluent containing indigo dye, auxiliaries, heavy metals, oils, and solids. The physicochemical properties of the membranes and effluent were evaluated. X-ray diffraction, energy dispersive X-ray fluorescence spectros- copy, differential scanning calorimetry, and thermogravimetric analysis confirm that the thin membrane is composed of high crystalline and pure α-alumina. Scanning electron microscopy observation indicates that the membranes have smooth porous surface making it suitable for microfiltration applications. The membrane sintered at 1,450 ̊C exhibited higher water absorp- tion (WA) and apparent porosity than that sintered at 1,475 ̊C. The apparent specific gravity and flexural strength are in inverse correlation with the WA due to the enhanced densification of the membranes. The filtered effluent was evaluated using a membrane with an average pore size of 0.4 μm and a total porosity of 29.6%. The average values of rejection were 90% for color, 93% for suspended solids, 95% for turbidity, 60% for metals, and 73% for chemical oxygen demand. These results demonstrate that low-cost ceramic alumina membranes are a very promising advanced treatment for textile industrial effluentsArtigo Statistical study of performance properties to impact of Kevlar® woven impregnated with Non-Newtonian Fluid (NNF)(Elsevier, 2020-05) Santos, Thiago Felix dos; Santos, Caroliny Minely da Silva; Aquino, Marcos Silva de; Oliveira, Fernando R.; Medeiros, José Ivan deThis investigative work was carry out through a factorial planning, using Design of Experiment (DoE) in order to evaluate the impact performance properties of Kevlar® woven structure impregnated with Non-Newtonian Fluids (NNF). Pull out and drop tower tests were performed. The pull out test showed that Kevlar® strength values with NNF composition 3 were better (10.55 N) when compared to others (1 and 2). The drop tower test showed that woven samples with highest concentration of NNF nanoparticles (3OR) exhibited the best behavior with respect to the penetration depth for P1 (19.5%) and S1 (48.0%) knife blade geometries. Thus, evidencing best residual energy dissipation when compared to the others. Results also showed that the composition (1, 2 and 3) of NNF as well as the orientation of the woven layers can be used to improve impact performance properties. Therefore, the impact protection performance depends on the friction between the yarns (pull out), the knife blade geometry and mainly the composition of the NNF which, in turn, is directly related to the nanoparticle and agent content of silane coupling present in the composition of the Non- Newtonian Fluid. Finally, this study also demonstrates that the use of statistical analysis promoted the improvement for obtaining and effectiveness of the behavior of lightweight impact protection textile structures