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Journal of Thermal Analysis and Calorimetry
Authors: Edjane F. B. Silva, Marcílio P. Ribeiro, Ana C. F. Coriolano, Ana C. R. Melo, Anne G. D. Santos, Valter J. Fernandes Jr., and Antonio S. Araujo

Abstract

Thermogravimetry was applied in order to investigate the catalytic degradation of heavy oil (15.4oAPI) over silica-based MCM-41 mesoporous molecular sieve. This material was synthesised by the hydrothermal method, using cetyltrimethylammonium bromide as organic template. The physicochemical characterization by nitrogen adsorption, X-ray diffraction, and thermogravimetry, showed that the obtained material presents well-defined structure, with a uniform hexagonal arrangement. The thermal and catalytic degradation of heavy oil was performed by thermogravimetric measurements, in the temperature range from 30 to 900 °C, at heating rates of 5, 10, and 20 °C min−1. By using the model-free kinetics, proposed by Vyazovkin, it was determined that the activation energy to degrade the heavy oil was ca. 128 kJ mol−1, and for degradation of oil in presence of MCM-41, this value decreased to 69 kJ mol−1, indicating the performance of the mesoporores catalyst for the degradation process.

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Journal of Thermal Analysis and Calorimetry
Authors: M. F. Silva, E. A. G. Pineda, A. A. W. Hechenleitner, D. M. Fernandes, M. K. Lima, and P. R. S. Bittencourt

Abstract

The acetone-soluble lignin fraction (ASLF) of sugar cane bagasse, from a sugar and alcohol factory residue, was obtained after extraction with formic acid and used to prepare blends with poly(vinyl acetate) (PVAc) by casting. PVAc and ASLF/PVAc blends were irradiated with ultraviolet light (Hg lamp). Blend formation and the irradiation effects were examined through thermal analysis (TG and DSC), scanning electron microscopy, and atomic force microscopy. The DSC results show PVAc glass transition temperature (T g) shifts because of both, irradiation and ASLF incorporation. Non-irradiated pure PVAc presented a smooth surface, while after UV irradiation, light surface spots are observed. ASLF/PVAc 10/90 and 5/95 blends did not exhibit differences before and after UV irradiation, suggesting that lignin protects PVAc from photochemical degradation.

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Acta Veterinaria Hungarica
Authors: Laís L. Fernandes, Sheila C. Rahal, Alexandre T. Fabro, Sabrina S. Batah, Alicia G. Hippólito, Jacqueline M. Bisca, Inajara N. Hirot, and Carlos R. Teixeira

The aim of this study was the preparation and histological evaluation of Leukocyte- and Thrombocyte-Rich Fibrin (L-TRF) membranes obtained from the blood of four bird species. Forty adult healthy birds were divided into four groups of equal size: G1 – macaws, G2 – domestic chickens, G3 – parrots, G4 – toco toucans. A total of 0.5 mL of blood was collected from each bird, put into a glass tube without anticoagulant and centrifuged at 3000 rpm for 10 min. L-TRF membranes produced after compression of the clot were processed for histological analysis. The ratio of thrombocytes/area was not significantly different among Groups G2, G3 and G4, but a significant difference was found between Groups G1 and G2 with the highest thrombocyte concentration/area in G1. The groups did not differ statistically in the number of leukocytes/area. The fibrin-to-cells ratio did not vary statistically among Groups G1, G2 and G3, but this ratio was significantly higher in Group G4 than in the other groups. The thrombocyte-to-leukocyte ratio was the highest in Group G1, but it did not differ among Groups G2, G3 and G4. In conclusion, the centrifugation protocol allowed the production of L-TRF membranes in the four bird species studied. Histologically, cell ratios were analogous in domestic chickens and parrots, and macaws had the highest ratio of thrombocytes.

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Summary  

Sediment cores from Catingueiro, Barrinha and Rio das Pedras marginal lagoons of the Moji-Guaçu River basin were analyzed for rare earth elements (REEs), Fe, Ta and Th by instrumental neutron activation analysis (k 0-INAA). Data indicated similarities between Catingueiro and Barrinha lagoons, while a distinct scenario was seen for Rio das Pedras likely due to changes of sedimentation rate in 1950's. By using Fe, Sc, Ta and Th as conservative elements, double normalization technique was performed in order to assess the distribution pattern of Ce, Eu, La, Sm and Tb for each core. In all cases, it was evident a depletion of lighter REE elements in the Rio das Pedras lagoon.

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Journal of Thermal Analysis and Calorimetry
Authors: Rosiane M. C. Farias, Marta M. Conceição, Roberlúcia A. Candeia, Marta C. D. Silva, Valter J. Fernandes Jr., and Antonio G. Souza

Abstract

The diversity of raw materials and technological routes employed in the biodiesel production has resulted in products with different chemical properties. This non-uniformity in the biodiesel composition may influence to the fuel quality. The aim of this study was to evaluate biodiesel blends of passion fruit and castor oil in different proportions and their thermal stability. Biodiesel blends of passion fruit and castor oil presented parameters in the standards of the Petroleum, Natural Gas and Biofuels National Agency. The TG curves indicated that castor oil biodiesel was more stable. Passion fruit biodiesel has a high content of oleic and linoleic acids, which are more susceptible to oxidation. Biodiesel blend of passion fruit and castor oil 1:1 increased the thermal stability in relation to passion fruit biodiesel. Biodiesel blend of passion fruit and castor oil 1:2 presented higher thermal stability, because castor oil has a high content of ricinoleic acid.

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Journal of Thermal Analysis and Calorimetry
Authors: S. C. Souza, M. A. F. Souza, S. J. G. Lima, M. R. Cassia-Santos, V. J. Fernandes Jr., L. E. B. Soledade, E. Longo, A. G. Souza, and I. M. G. Santos
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Acta Alimentaria
Authors: A. Vásquez García, S.H. Gomes de Sá, G. de Sousa Silva, J.E. Mejia Ballesteros, E. Barbieri, R.L. Moro de Sousa, A.M. Fernandes, and M. Mitsui Kushida

The objective of this study was to evaluate the microbiological quality of oysters and mussels grown in Cananéia, Brazil, by analysing mesophiles, psychrothophic bacteria, moulds and yeasts, Staphylococcus aureus, and Salmonella spp., and to compare the efficiency of Compact Dry EC method and the conventional method for counting of total coliforms and Escherichia coli. The microbial analysis showed that the mean values of mesophilic counts were 3.14±0.81 log CFU g−1 for oysters and 3.92±0.90 for mussels; the mean values of psychrophilic counts were 2.78±0.75 log CFU g−1 for oysters and 3.22±0.75 log CFU g−1 for mussels; the mean values of mould and yeast counts were 3.70±0.58 log CFU g−1 for oysters and 3.33±0.81 log CFU g−1 for mussels. Salmonella spp. did not present positive results, and the maximal count of Staphylococcus aureus was 1.7 log CFU g−1, therefore, within the limits established in the legislation. The correlation coefficients between the Compact Dry EC method and conventional method were >0.87 for total coliform and E. coli counts for both types of shellfish. The data in this study show that the Compact Dry EC method is an acceptable alternative to conventional methods for enumeration of total coliforms and E. coli in shellfish.

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