Palaeosurfaces mapping and associated supergene copper deposits identification as mineral exploration tool Itapeva and Ribeirão Branco region – Ribeira Valley, state of São Paulo, Brazil

Alguns exemplos de formação de minério supérgeno e sua interação com a morfogênese (paleosuperfícies) e resistência mineralógica são discutidas aqui. Registros geomorfológicos e mineralógicos na caracterização paleosuperfícies associam o intemperismo de minerais primários e sua relação com as concentrações de cobre e minério de ferro no sudeste do estado de São Paulo, Brasil. Distinguiram-se duas paleosuperfícies geradas por várias fases de intemperismo e controladas pela estrutura geológica. A primeira, mais antiga, é a paleosuperfície superior (900 - 1000 m de altitude), situado em Ribeirão Branco (Alto do Brancal), foram desenvolvidas em rochas silico-calcários. É formada por lateritas de ferro enriquecido por produtos secundários de cobre. O segundo nível de paleosuperfície é mais novo está localizado na região de Itapeva (Santa Blandina e Bairro do Sambra). Esta paleosuperfície é formada por percolação de cobre através da rocha alterada (saprolito). Outras características podem ser observadas como produtos neoformados em lateritas. Eles são classificados em dois tipos: a argila como produtos silico-cuprífero (com quantidades significativas de ferro) e de cobre minerais (crisocola, fixas nas vertentes). Essas feições reconheceram a presença de minérios de cobre e seu controle morfogénetico ajudando na exploração e prospecção de minérios supérgenos.

Multivariate curve resolution analysis applied to time-resolved synchrotron X-ray Absorption Spectroscopy monitoring of the activation of copper alumina catalyst

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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)

Aging of plasma-activated copper and gold surfaces and its hydrophilic recovery after water immersion

A significant increase of surface hydrophilicity of copper and gold surfaces was obtained after atmospheric pressure plasma treatment using the surface dielectric barrier discharge with specific electrode geometry, the so-called diffuse coplanar surface barrier discharge. Surface wettability was estimated using the sessile drop method with further calculation of the surface free energy. After the plasma treatments, it was observed that the treated surfaces exhibited hydrophobic recovery (or aging effect). The aging effect was studied in different storage environments, such as air, low and high vacuum. The role of plasma and the reasons of the following aging effect are discussed with respect to the observed hydrophilic recovery after immersing the aged surfaces into deionized water. The changes in the surface morphology, composition and bond structure are presented and discussed as well. (C) 2013 Elsevier B. V. All rights reserved.

The rolling ball problem on the plane revisited

By a sequence of rollings without slipping or twisting along segments of a straight line of the plane, a spherical ball of unit radius has to be transferred from an initial state to an arbitrary final state taking into account the orientation of the ball. We provide a new proof that with at most 3 moves, we can go from a given initial state to an arbitrary final state. The first proof of this result is due to Hammersley ( 1983). His proof is more algebraic than ours which is more geometric. We also showed that generically no one of the three moves, in any elimination of the spin discrepancy, may have length equal to an integral multiple of 2 pi.

Copper oxychloride fungicide and its effect on growth and oxidative stress of potato plants

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Kinetic role of a histidine residue in the T1 copper site of the laccase from Rigidoporus lignosus

Laccases (benzendiol:oxygen oxidoreductases; EC 1.10.3.2) catalyze the oxidation of a broad range of substrates, such as polyphenols, dyes and pollutants, and thus these enzymes are widely applied in industrial, biotechnological and environmental fields. In order to improve their biotechnological applications, a deep knowledge of structural factors involved in controlling their activity, in various experimental conditions and on different substrates, is required. In the present study, a laccase from the mushroom Rigidoporus lignosus was kinetically characterized. In particular, the stability, the effects of pH, ionic strength and fluoride ion concentration on the kinetic parameters were investigated, using three di-hydroxy-benzene isomers (1,2-dihydroxy-benzene, 1,3-dihydroxy-benzene and 1,4-dihydroxy-benzene) as substrates. The catalytic constant values of the laccase showed a bell-shaped pH profile, with the same optimum pH and pK(a) values for all tested substrates. This behavior appears to be due to the presence of an ionizable residue in the enzyme active site. To identify this residue, the enzyme was derivatized with diethylpyrocarbonate to modify accessible histidine residues, which, according to structural data, are present in the active site of this enzyme. The kinetic behavior of the derivatized laccase was compared with that of the native enzyme and the derivatized residues were identified by mass spectrometry. Mass spectrometry and kinetic results suggest the main role of His-457 in the control of the catalytic activity of laccase from R. lignosus. (C) 2013 Elsevier B.V. All rights reserved.

Copper(II) and Nickel (II) Complexation Capacity of Dissolved Organic Matter from Rivers of Agricultural and Urban Areas in the State of Sao Paulo

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

Redox dysregulation and bioaccumulation of copper in tilapia Oreocromis niloticus

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

A novel hybrid composite formed by reaction of 4,5-diphenyl-2-imidazolethiol with hexacyanoferrate (iii) and subsequent reaction with copper (ii): preparation, characterization and a voltammetric application for determination of l-glutatione

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

Simultaneous Determination of Iron and Copper in Ethanol Fuel Using Nafion/Carbon Nanotubes Electrode

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

Hydroxyquinoline derived vanadium(IV and V) and copper(II) complexes as potential anti-tuberculosis and anti-tumor agents

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

Exploring copper nanostructures as highly uniform and reproducible substrates for plasmon-enhanced fluorescence

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

EVALUATION OF EUCALYPTUS KRAFT PULP LIGNIN THROUGH THE NITROBENZENE OXIDATION, COPPER OXIDE REDUCTION AND ACIDOLYSIS TECHNIQUES

This study aimed to evaluate the sensitiveness of the information obtained for the residual lignin from Eucalyptus grandis kraft pulps analyzed through the nitrobenzene oxidation, copper oxide (CuO) reduction and acidolysis techniques. The chips were cooked, resulting pulps of kappa number 14,5 and 16,9, respectively. Both lignins' pulps were evaluated through three methods (nitrobenzene oxidation, copper oxide oxidation and acidolysis). Then, they were subjected to an oxygen delignification stage. The 16,9 kappa number pulp resulted in higher levels of non-condensed lignin structures by the acidolysis method, higher syringyl/vanillin ratios (S/V) by the nitrobenzene and copper oxide methods and better performance in the oxygen delignification stage. The different methods allowed to differ the residual lignin pulps with kappa number 14,5 and 16,9, and the nitrobenzene oxidation method showed the highest sensitiveness in this study results.

Rolling Stone Brasil: aspectos de interatividade

The purpose of the present dissertation is to show the interactivity connections featured in a cultural journalism magazine's website through direct observation of its presented structure. The website chosen as object of study is Rolling Stone Brasil, April 2010 being the point of reference for analysis. Methodological support for such study has been culled from theoretical works on the principles that are necessary for the development of sampling in the observed structure. For this, are employed of concepts and strategies predicated by authors in the field of communications with emphasis on digital means is aplicated. The research indicates that the tools adopted in the website's structure comprise a potential of interactivity between the parties involved in the communication chain, and that the content therein produced may be considered as direct content of a web journalism structure