Análises de solos e sedimentos de corrente, nas áreas das usinas de fundição de chumbo do Calabouço (CIEM-CPRM) e de beneficiamento de minério aurífero do Morro do Ouro (Parque Municipal Morro do Ouro), no município de Apiaí - SP

Located in Apiaí, Vale do Ribeira, southern region of São Paulo state, the Usina do Calabouço areas (CIEM / CPRM) and Morro do Ouro (Parque Municipal do Morro do Ouro), were targeted for stud ies due to its old buildings, respectively a foundry in lead ore, called Experimental de Chumbo e Prata (Usina Calabouço), and a gold mine with processing plant of the gold-bearing ore produced there. Nowadays, the areas are used for public visitation, and in both places the rests of the buildings remains. Particularly in the CIEM/CPRM, due to the materials witch was produced before, it can suggest the existence of anomalous amounts of the involved metals (CIEM / CPRM) and possible contaminations by chemical products used in the improvement of the auriferous ore (P. M. Morro do Ouro). These potential contamination were confirmed with geochemical survey of soils and current sediments accomplished in both areas, for the elements arsenic, cadmium, lead, copper, mercury, silver and zinc, which were used as parameters guiding values for soil and groundwater the state of São Paulo (CETESB), and watershed values stipulated by CPRM (poor, background and anomalous), in it rising geochemistry during Folha Apiaí's execution (SG-22-X-B-V).

Mapeamento geológico e petrologia dos complexos máfico-ultramáficos de Mangabal Sul e Mangabal Norte, região de Sanclerlândia, Goiás

The Mangabal Sul and Mangabal Norte mafic-ultramafic complexes are interpreted as intrusive stratiform bodies in the Goiás Magmatic Arc during the Brazilian cycle, being economically important for harboring significant amounts of nickel and copper sulfides. The main lithotypes of the complexes are gabbronorites, olivine gabbronorites, pyroxenites and peridotites, with variated degrees of deformation, recrystallization and metamorphism superimposed, with metamorphic peak of amphibolite to granulite facies evidenced mainly by the occurrence of coronitic olivine in metamafic rocks and the occurrence of syn-kinematic retrometamorphism associated with the development of the main foliation Sn. The Sn foliation planes show NE-SW preferential direction, consistent with the foliation direction of VIII the enclosing gneisses and schists, also concordant with the general elongation of mafic and ultramafic bodies displayed on map. The sulfide phase presents textures that indicate remobilization, associated with the occurrence of significant amounts of rutile within the ore which reinforces this idea. Along with the sulfides, the occurrence of expressive quantities of titanium oxides such as ilmenite and rutile, make the area more economically attractive. It can be suggested that the Mangabal Norte and Mangabal Sul complexes are contemporary, have the same genetic affinity and suffered the same deformational and metamorphic processes, evidenced by their structural and petrological similarities

A simple method based on ICP-MS for estimation of background levels of arsenic, cadmium, copper, manganese, nickel, lead, and selenium in blood of the Brazillian population

Throughout the world, biomonitoring has become the standard for assessing exposure of individuals to toxic elements as well as for responding to serious environmental public health problems. However, extensive biomonitoring surveys require rapid and simple analytical methods. Thus, a simple and high-throughput method is proposed for the determination of arsenic (As), cadmium (Cd), copper (Cu), manganese (Mn), nickel (Ni), lead (Pb), and selenium (Se) in blood samples by using inductively coupled plasma–mass spectrometry (ICPMS). Prior to analysis, 200 ml of blood samples was mixed with 500 ml of 10% v/v tetramethylammonium hydroxide (TMAH) solution, incubated for 10 min, and subsequently diluted to 10 ml with a solution containing 0.05% w/v ethylenediamine tetraacetic acid (EDTA) + 0.005% v/v Triton X-100. After that, samples were directly analyzed by ICP-MS (ELAN DRC II). Rhodium was selected as an internal standard with matrix-matching calibration. Method detection limits were 0.08, 0.04, 0.5, 0.09, 0.12, 0.04, and 0.1 mg//L for As, Cd, Cu, Mn, Ni, Pb, and Se, respectively. Validation data are provided based on the analysis of blood samples from the trace elements inter-\comparison program operated by the Institut National de Santé Publique du Quebec, Canada. Additional validation was provided by the analysis of human blood samples by the proposed method and by using electrothermal atomic absorption spectrometry (ETAAS). The method was subsequently applied for the estimation of background metal blood values in the Brazilian population. In general, the mean concentrations of As, Cd, Cu, Mn, Ni, Pb, and Se in blood were 1.1, 0.4, 890, 9.6, 2.1, 65.4, and 89.3 mg/L, respectively, and are in agreement with other global populations. Influences of age, gender, smoking habits, alcohol consumption, and geographical variation on the values were also considered. Smoking habits influenced the levels of Cd in blood. The levels of Cu, Mn, and Pb were significantly correlated with gender, whereas Cu and Pb were significantly correlated with age. There were also interesting differences in Mn and Se levels in the population living in the north of Brazil compared to the south.

Voltammetric behaviour of a modified electrode with azide copper octa(3-aminopropyl)octasilsesquioxane composite in the oxidation of ascorbic acid

A novel nanostructured composite, azide copper octa (3-aminopropyl)octasilsesquioxane (ASCA) was incorporated into a graphite paste electrode and the electrochemical studies were conducted with cyclic voltammetry. The cyclic voltammogram of the modified graphite paste electrode with ASCA (GPE-ASCA), showed one redox couple with formal potential (E  ) = 0.30 V and an irreversible process at 1.1 V (vs Ag/AgCl; NaCl 1.0 mol L-1 ; v = 20 mV s-1 ). The redox couple with (E  ) = 0.30V presents an electrocatalytic response for determination of ascorbic acid. The modified electrode gives a linear range from 1.010-4 – 1.010-3 mol L-1 (r = 0.998) for the determination of ascorbic acid with detection limit of 6.910-5 mol L-1 and standard deviation of 2.3% for n = 3 . The amperometric sensitivity was 122.1 mA/mol L-1 for ascorbic acid. The application this electrode was tested and ascorbic acid in three commercial pharmaceutical product (Cebion, Cewin and Redoxon) have been determined.

Determination of uronic acids in sugarcane bagasse by anion-exchange chromatography using an electrode modified with copper nanoparticles

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

Direct preparation and characterization of copper pentacyanonitrosylferrate nanoparticles

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

Correlation between structural and catalytic properties of copper supported on porous alumina for the ethanol dehydrogenation reaction

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Effects of humidity on the electrical properties of thermal inkjet-printed films of copper tetrasulfonated phthalocyanine (CuTsPc) onto paper substrates

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

Thermal inkjet printing of copper tetrasulfonated phthalocyanine (CuTsPc) as a semiconducting layer on flexible MIS capacitors

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

Alterations of protein expression in conditions of copper-deprivation for Paracoccidioides lutzii in the presence of extracellular matrix components

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

Study of ceramic block manufacture with the addition of waste from iron ore extraction

This work is intended to study the possibility of adding an amount of waste from iron mining in the ceramic mass. Clay and coal, from Vale do Paraiba, Sao Paulo, Brazil, were used in this research. These raw materials are used in the ceramic block manufacture. Clay and waste were analyzed by X-ray fluorescence and X-ray diffraction, particle size, differential thermal and thermogravimetric analysis. Liquid limit and plasticity index tests were performed in order to determine the amount of waste that which should be used in the ceramic mass. After determining the amount of waste, all samples were uniaxially pressed and sintered at 900 degrees C. Surface roughness measurements, apparent porosity and bulk density technique and three-point flexural tests were also performed to characterize the samples. The results showed that by adding the exact amount of waste, which was determined by the essays, it is possible to manufacture solid bricks.

Preparation and thermal decomposition of solid state cobalt, nickel, copper and zinc chelates of ethylenediaminetetraacetic acid

Solid state chelates of general formula H-2[M(EDTA)] . nH2O, where M is Co, Ni, Cu or Zn, and EDTA is ethylenediaminetetraacetate, were prepared. Thermogravimetry-derivative thermogravimetry (TG-DTG), differential thermal analysis (DTA) and complexometry were used to characterize and to study the thermal stability and thermal decomposition of these compounds.

Effects of copper vapor laser irradiation (λ = 510.6 nm) on the enamel and dentine of human teeth: An ultra-structural morphologic study

Objective: A morphological and ultra-structural study of copper vapor laser (λ = 510.6 nm) effects on enamel and dentine was performed to show the effects of this radiation. Methods: A total of 15 human molars were cut in half; 15 pieces were separated for irradiation on enamel and 15 for dentine. These two groups were further divided into five experimental groups, including a control group, comprised of three half-sections each, irradiated by a CVL laser with a power of 7 W, a repetition rate of 15,000 pulses/sec and exposed at 500, 600, and 800 msec and 1 sec irradiation times with a 5-sec interval between irradiations. Results: In an ultra-structural SEM exam, we observed that on the enamel surfaces irradiated for 1 sec there was morphological alteration that consisted of catering, flaking, and melting on the surfaces. There was no alteration for the other exposure times. On the dentine teeth irradiated for 1 sec, we observed an evident ultra-structural alteration of melted tissue and loss of morphological characteristics. In the dentine group irradiated by 800 msec, we observed ablation and a partial loss of morphological characteristics. In the dentine groups irradiated by 500 and 600 msec, no alteration was observed. Conclusions: The results showed that irradiation with CVL promoted morphologic changes in the enamel as well as in the dentine and demonstrated a need for future studies in order to establish a safe protocol for further use in the odontological practice.

Correlation between i.r. spectra and thermal decomposition of cobalt(II), nickel(II), copper(II) and mercury(II) complexes with piperidinedithiocarbamate and pyrrolidinedithiocarbamate

The thermal decomposition of pyrrolidinedithiocarbamate and piperidinedithiocarbamate complexes of CoII, NiII, CuII and HgII have been studied by thermogravimetry and differential scanning calorimetry. The decomposition intermediates and final products were identified by their X-ray diffraction patterns. The i.r. spectra are discussed in terms of the thermal decomposition pathways.

Electrochemical studies of copper, copper-aluminium and copper-aluminium-silver alloys: Impedance results in 0.5M NaCl

The electrochemical behaviour of Cu, Cu-Al and Cu-Al-Ag alloys in aqueous solutions of NaCl (0.5 M, pH = 3.00) was studied by means of voltammetric methods and electrochemical impedance spectroscopy. The surfaces were examined by SEM and EDX analysis. Cu-Al-Ag alloy shows a potentiodynamic behaviour similar to that of the pure copper electrode while the Cu-Al alloy presents some minor differences. In the active dissolution region the electrodes suffer pitting corrosion and in the other potential regions there are the formation of a passivant film with composition depending on the potential. The impedance responses of the electrodes are discussed. An electrodissolution mechanism is proposed and the effect of the alloying elements upon the impedance response and polarisation curves is explained. The main effects are due to the production of copper and silver chlorides and aluminium oxides/ hydroxides at the corroding interface. The addition of Al or (Al + Ag) increases the corrosion resistance of pure copper. © 1995.