Simple, Direct and Simultaneous Stripping Voltammetric Determination of Lead and Copper in Gasoline Using an In Situ Mercury Film Electrode

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Seasonal variability of a conditional stability constant and the characterization of sedimentary humic substances from typical agricultural and urban areas

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Determinação de metais em água produzida de petróleo

In order to enable the reuse of the large surplus volume of petroleum produced water for irrigation of crops inedible, the quality evaluation of this water is very important. This work aimed to evaluate the effectiveness of the diffusive gradient in thin films technique (DGT) for the determination of labile Cu (II), Mn (II) and Zn (II) in petroleum produced water destined to reuse in agriculture. Samples were collected at the exit of the wastewater treatment plant (WWTP) (after separation oil/water and flotation) of a Petrobrás onshore production region. Basically, the laboratory experiments with DGT devices involved the evaluation of the behavior of the main variables of the technique for determination of analytes in the samples (diffusion coefficients, immersion time, fractionation of organic and inorganic species, and performance of diffusion gels with different porosities, among others). Also, experiments were conducted based on the solid phase extraction (SPE) protocol with Chelex- 100 resin using previously established protocols to support the study. During the project the possibility of in situ immersions in water treatment plants was evaluated. The DGT technique presented satisfactory results for determination of Mn in produced water, and can be used for in situ determinations. However, the results obtained for Cu and Zn show the need of additional studies

Electropolymerization using binuclear nickel(II) Schiff base complexes bearing N4O4 donors as supramolecular building blocks

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Preparação e caracterização de membranas de celulose regenerada a partir da celulose extraída de resíduos agroindustriais para aplicação em processos de separação

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Complexation of some trivalent lanthanides, scandium(III) and thorium(IV) by benzylidenepyruvates and cinnamylidenepyruvate in aqueous solution

The protonation constants of benzylidenepyruvate, 2-chloro-, 4-chlorobenzylidinepyruvate and cinnamylidenepyruvate as well as the stability constants of their binary 1:1 complexes with Cu(II), La(III), Pr(III), Sm(III), Lu(III), Sc(III) and Th(IV) have been determined spectrophotometrically in an aqueous medium at 25 °C and ionic strength 0.500 M, held with sodium perchlorate. Coordination centres in the aforementioned ligands are suggested. © 1995.

Structural insights into substrate binding of brown spider venom class II phospholipases D

Phospholipases D (PLDs), the major dermonecrotic factors from brown spider venoms, trigger a range of biological reactions both in vitro and in vivo. Despite their clinical relevance in loxoscelism, structural data is restricted to the apo-form of these enzymes, which has been instrumental in understanding the functional differences between the class I and II spider PLDs. The crystal structures of the native class II PLD from Loxosceles intermedia complexed with myo-inositol 1-phosphate and the inactive mutant H12A complexed with fatty acids indicate the existence of a strong ligand-dependent conformation change of the highly conserved aromatic residues, Tyr 223 and Trp225 indicating their roles in substrate binding. These results provided insights into the structural determinants for substrate recognition and binding by class II PLDs.

The preparation and thermal decomposition of some metal compounds of 4-dimethylaminobenzylidenepyruvate in the solid state

Solid M-DMBP compounds, where M represents Mg(II), Ca(II), Sr(II), Ba(II), Ni(II), Cu(II), Zn(II), Fe(III), La(III), Th(IV), and DMBP is 4-dimethylaminobenzylidenepyruvate, have been prepared. Thermogravimetry-derivative thermogravimetry (TG-DTG), differential scanning calorimetry (DSC) and other methods of analysis have been used to characterize and to study the thermal stability and thermal decomposition of these compounds. © 1995.

Reforma agrária e estrutura fundiária no Brasil: uma análise a partir do I Plano Nacional de Reforma Agrária

Pós-graduação em Economia - FCLAR

Adsorção de metais em solução aquosa pelos processos de batelada e coluna de leito fixo utilizando silsesquioxano funcionalizado com 5-amino-1,3,4-tiadiazol-2-tiol

Pós-graduação em Ciência dos Materiais - FEIS