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Abstract  

The standard (p0=0.1 MPa) molar enthalpies of formation, ΔfHm0, for crystalline phthalimides: phthalimide, N-ethylphthalimide and N-propylphthalimide were derived from the standard molar enthalpies of combustion, in oxygen, at the temperature 298.15 K, measured by static bomb-combustion calorimetry, as, respectively, – (318.01.7), – (350.12.7) and – (377.32.2) kJ mol–1. The standard molar enthalpies of sublimation, ΔcrgHm0, at T=298.15 K were derived by the Clausius-Clapeyron equation, from the temperature dependence of the vapour pressures for phthalimide, as (106.91.2) kJ mol–1 and from high temperature Calvet microcalorimetry for phthalimide, N-ethylphthalimide and N-propylphthalimide as, respectively, (106.31.3), (91.01.2) and (98.21.4) kJ mol–1. The derived standard molar enthalpies of formation, in the gaseous state, are analysed in terms of enthalpic increments and interpreted in terms of molecular structure.

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Reaction Kinetics, Mechanisms and Catalysis
Authors: Cleanio L. Lima, Hélvio S. A. de Sousa, Santiago J. S. Vasconcelos, Josué M. Filho, Alcemira C. Oliveira, Francisco F. de Sousa, and Alcineia C. Oliveira

Abstract

Sulfated molecular sieves were synthesized and characterized by XRD, FTIR, chemical analyses, acidity measurements and N2 adsorption–desorption isotherms. Sulfatation led to structural changes in the solid framework by increasing the acidity and accessibility of the acid sites. Br⊘nsted and Lewis acid sites of mild to high strength improved the conversion of alcohols, but the selectivity was modest over sulfated FAU type Y, ZSM-5 and γ-Al2O3 solids at temperatures lower than 200 °C. The characteristics of the sulfated AlSBA-15 molecular sieve in terms of acidity, textural properties and accessibility possibly make this solid useful for catalytic reactions involving bulky organic compounds.

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Acta Alimentaria
Authors: L. Silva, G. Maia, P. Sousa, R. Figueiredo, M. Afonso, M. Gonzaga, C. Gomes, and E. Figueiredo

The purpose of this experiment was to evaluate the effect of heat treatment on the rheological properties of mixed nectars, based on cashew apple, mango, and acerola pulps. Ten different formulations with different mass fractions of cashew apple, mango, and acerola pulps were prepared using a simplex centroid design [with a total of 35% (w/w) pulp] and submitted to heat treatment at 90 °C for 1 min. Samples were collected before and after heat treatment and characterization of their rheological properties was carried out. The rheological behaviour was obtained at 25 °C, with shear rate ranging from 108 to 500 s−1 (upward curve) and from 500 to 108 s−1 (downward curve) for 1 min with 25 readings for each curve. The Ostwald de Waele model showed to be a good fit for all formulations studied, which showed a non-Newtonian behaviour and a pseudoplastic character. Results of apparent viscosity for the non-heated formulations were well fitted by the linear model and the heat treated formulations by the cubic model. The heat treated formulations had higher (P<0.05) values of consistency index and apparent viscosity, as well as lower (P<0.05) values of flow behaviour index compared to non-heated formulations. The rheological characterization of these formulations is a very useful tool during product development and processing control of mixed nectars of fruit juice.

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Abstract

In this work Chitosan (Ch) was chemically modified with ethylenesulfide (Es) under solvent-free conditions to give (ChEs), displaying a high content of thiol groups due to opening of the three member cyclic reagent. ChEs was used in studies of lead and cadmium adsorption from aqueous solution, using the batchwise method and calorimetric studies were accomplished to those interactions, through the calorimetric titration technique. The obtained results show that the modified Ch, ChEs is a material, that besides presenting the advantages of being a biopolymer, it showed a good adsorption capacity of the lead and cadmium cation metallic, that are extremely poisonous and harmful to the environment. The results of the calorimetric titration showed that the related thermodynamic parameters to those adsorptions shown favorable thermodynamic data.

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Abstract  

Biomonitoring of coastal areas using marine organisms is an attractive approach for studying pollution caused by anthropic discharges. Most of the experiments are based on the collection and analysis of native organisms, but this method has the disadvantage of dealing with many natural variations. In this work, the marine bivalve Perna perna, very abundant in the coast of the State of São Paulo, Brazil, was transplanted from a mussel farm and used for biomonitoring of four sites, situated in coastal regions close to domestic and/or industrial discharges. Hg, Cd and Pb were determined in the transplanted organisms by AAS and As, Ca, Co, Cr, Fe, Na, Se and Zn were determined by INAA.

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Abstract  

The increased pollution in the aquatic ecosystem has led to the investigation of toxic elements in sea water by using marine organisms to assess marine pollution from human activities. Among these organisms, the mollusks bivalves have been used as biomonitors since they can accumulate trace elements and other substances, without the occurrence of their death. In this study, Perna perna mussels were transplanted from a mussel farm (reference region) to four sites located in coastal regions of São Paulo State, Brazil, close to anthropic discharge areas. Vanadium was determined in mussel tissues by instrumental neutron activation analysis (INAA). Quality control of V analysis was checked by analyzing biological reference materials and the results obtained were precise and in good agreement with the certified values. Comparisons between the V concentrations obtained in transplanted mussels indicated that those from São Sebastião region, close to an oil terminal presented the highest concentration of this element, during spring.

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Journal of Radioanalytical and Nuclear Chemistry
Authors: M. Catharino, M. Vasconcellos, A. Kirschbaum, M. Gasparro, C. Minei, E. de Sousa, D. Seo, and E. Moreira

Abstract  

The marine environment is constantly affected by anthropic actions, with causes consequent degradation of the waters and marine biota by various discharges of xenobiotics. In the present study, the focus was the study of a region of the marine coast of the State of São Paulo (city of Santos), which is one of the most industrialized parts of Brazil and suffers also from a strong impact of domestic effluents. The mussel Perna perna, very abundant in the coast of the State of São Paulo, Brazil, was selected as the biomonitoring organism for the determination of inorganic elements and a passive biomonitoring was performed. The organisms were collected at two sites in São Paulo State coast: Cocanha beach in Caraguatatuba (mussel farm) and Santos Bay (Itaipu and Palmas). Seasonally, the Perna perna were collected between September/08 and July/09 in each study sites. After removal and sample preparation, the elements As, Co, Cr, Fe, Se and Zn were determined by instrumental neutron activation analysis (INAA) and Cd, Pb and Hg were determined by atomic absorption spectroscopy (AAS) in this organism.

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Community Ecology
Authors: D. M. S. Abessa, B. R. F. Rachid, L. P. Zaroni, M. R. Gasparro, Y. A. Pinto, M. C. Bícego, M. A. Hortellan, J. E. S. Sarkis, P. Muniz, L. B. Moreira, and E. C. P. M. Sousa

Abstract

The Santos Estuarine System (SES) is a complex of bays, islands, estuarine channels, and rivers located on the Southeast coast of Brazil, in which multiple contaminant sources are situated in close proximity to mangroves and other protected areas. In this study, the composition and structure of the macrobenthic communities of SES were described and ninety-nine species were identified, with the predominance of polychaetes and bivalve mollusks. The benthic assemblages also showed strong signs of stress, as indicated by the low abundance, richness and diversity, and the dominance of opportunistic species. Integrated analysis including sediment characteristics related to natural and anthropogenic factors (e.g., sediment chemistry, and toxicity) indicated that benthic fauna from the inner portions of the SES and vicinities of the SSOS diffusers as Santos Bay were affected. Some locations at the mouths of Santos and Sao Vicente estuaries exhibited moderate disturbance. In other sites from the mouth of São Vicente and Bertioga channels, and Santos Bay, the benthic fauna were considered not degraded. Our results suggest that a combination of both environmental factors and contaminants were responsible for the benthic community structure.

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Acta Alimentaria
Authors: L.B.S. Sabino, M.L.C. Gonzaga, D.J. Soares, A.C.S. Lima, J.S.S. Lima, M.M.B. Almeida, P.H.M. Sousa, and R.W. Figueiredo

This study is aimed at performing the determination of bioactive compounds, antioxidant activity, and the identification of the minerals in the flours produced with the tropical fruit peels of mango, papaya, melon, and pineapple. The results showed that the papaya peel flour has the highest amount of ascorbic acid and lycopene when compared with the other studied flours. The mango peel flour has a high content of total extractable polyphenols and a high antioxidant activity. Regarding the mineral content, the by-product of melon stood out with 523.24±26.12 mg/100 g of potassium, 104.15±3.52 mg/100 g of calcium and 6.62±0.30 mg/100 g of iron. The flours prepared with mango, papaya, melon, and pineapple peels are potential sources of bioactive compounds and minerals, also presenting good antioxidant activity, being, therefore, recommended to be used in food products to improve the nutritional quality of the product.

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