Austenite decomposition of C-Mn steel containing boron by continuous cooling

The austenite decomposition in C-Mn steel containing boron was studied by continuous cooling from 1100 and 845 degreesC using the Jominy test. The results indicate that the different cooling speeds and the presence of boron refine and change the percentage of ferrite microstructure, martensite, and fine pearlite. (C) 2001 Elsevier B.V. B.V. All rights reserved.

Surface equilibrium angle for anisotropic grain growth in SnO2 systems

Usually, the kinetic models used in the study of sintered ceramic are performed by means of indirect physical tests, such as, results obtained from data of linear shrinkage and mass loss. This fact is justified by the difficulty in the determinations of intrinsic parameters of ceramic materials along every sintering process. In this way, the technique of atomic force microscopy (AFM) was used in order to determine the importance and the evolution of the dihedral angle in the sintering of 0.5 mol% MnO2-doped tin dioxide obtained by the polymeric precursor method.

Black and green pigments based on chromium-cobalt spinels

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

SrBi2(Ta0.5Nb0.5)(2)O-9 : W thin films obtained by chemical solution deposition: Morphological and ferroelectric characteristics

The effect of tungsten (W6+) ion substituting on dielectric and ferroelectric behavior in SrBi2(Ta0.5Nb0.5)(2)O-9 (SBTN) thin films prepared by polymeric precursor method was investigated at room temperature. The addition of W6+ ion in the SBTN lattice was evaluated by X-ray diffraction (XRD), microstructural and dielectrical properties. An increase in the grain size is evident when tungsten is introduced in the SBTN lattice. Substitution of tungsten until 10% on B site leads to introduce space charge polarization into the system, resulting in an appreciable decrease in both dielectric constant and tangent loss. The morphology of the thin films investigated by atomic force microscopy leads to an increase in the grain size after tungsten addition. Fatigue resistance was noted with increase in tungsten addition. (C) 2007 Elsevier B.V. All rights reserved.

SnO2 nanoparticles functionalized in amorphous silica and glass

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Preparation and thermal decomposition of copper(II), zinc(II) and cadmium(II) chelates with 8-hydroxyquinoline

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

Evaluation of the photoelectrocatalytic method for oxidizing chloride and simultaneous removal of microcystin toxins in surface waters

The production of chlorine was investigated in the photoelectrocatalytic oxidation of a chloride-containing solution using a TiO(2) thin-film electrode biased at current density from 5 to 50 mA cm(-2) and illuminated by UV light. Such parameters as chloride concentrations from 0.001 to 0.10 mol L(-1), pH 2-12, and interfering salts were varied in this study in order to determine their effect on this oxidation process. At an optimum condition this photoelectrocatalytic method can produce active chlorine at levels compatible to water disinfections processes using a chloride concentration higher than 0.010 mol L(-1) at a pH of 4 and a current density of 30 mA cm(-2). The method was successfully applied to treat surface water collected from a Brazilian river. After 150 min of photoelectrocatalytic oxidation, we obtained a 90% reduction in total organic carbon removal, a 100% removal of turbidity, a 93% decrease in colour and a chemical oxygen demand (COD) removal of around 96% (N=3). The proposed technology based on photoelectrocatalytic oxidation was also tested in treating 250 mL of a solution containing 0.05 mol L(-1) NaCl and 50 mu g L(-1) of Microcystin aeruginosa. The bacteria is completely removed after 5 min of photoelectrocatalysis following an initial rate constant removal of -0.260 min(-1), suggesting that the present method could be considered as a promising alternative to chlorine-based disinfections. (C) 2008 Elsevier Ltd. All rights reserved.

Preparation and thermal decomposition of solid state cinnamates of alkali earth metals, except beryllium and radium

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

Standartization of broth microdilution method for Mycobacterium tuberculosis

Indirect drug susceptibility tests of Mycobacterium tuberculosis was done to investigate the accuracy and feasibility of a broth microdilution method (BMM) for determining minimal inhibitory concentrations of conventional drugs against M. tuberculosis. Test drugs included isoniazid (H), rifampicin (R), ethambutol (E), streptomycin (S) and pyrazinamide (Z). Fifty isolates of M. tuberculosis from patients who had never received drug therapy, and H37Rv strain for control, were evaluated in the system. When comparing this method with the gold standard proportional method in Lowenstein-Jensen medium, sensitivity of 100% for all drugs and specifities of 91, 100, 96, 98 and 85% were observed respectively for H, R, E, S and Z. The BMM was read faster (14-20 days) than the proportional method (20-28 days). The microdilution method evaluated allows the testing of multiple drugs in multiple concentrations. It is easy to perform and does not require special equipment or expensive supplies. In contrast to radiometric method it does not use radioactive material.

Development and validation of a HPLC method for standardization of herbal and commercial extracts of Myrcia uniflora

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Spatial evaluation of larvae of Culicidae (Diptera) from different breeding sites: application of a geospatial method and implications for vector control

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Thermal decomposition of solid state compounds of lanthanide and yttrium benzoates in CO2 atmosphere

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

The Effect of the Aminic Substituent on the Thermal Decomposition of Cyclic Dithiocarbamates

Estudos termogravimétricos e calorimétricos diferenciais para ditiocarbamatos de NH4+, Na+, Zn2+, Cd2+ e Pb2+, derivados de aminas cíclicas contendo nitrogênio como heteroátomos, foram realizados em atmosferas de ar e nitrogênio, para avaliar a influência da tensão angular dos anéis na decomposição térmica destes compostos, em relação à formação de tiocianatos metálicos como via de decomposição. Os intemediários formados foram caracterizados por difração de raios-X, tendo sido encontrados oxissulfatos de Zn2+, Cd2+ e Pb2+, sob atmosfera de ar, o que sugere a decomposição térmica nestas condições como via sintética para estes compostos. Os produtos de decomposição final obtidos foram sulfetos metálicos sob nitrogênio e óxidos dos metais de transição e sulfato de sódio sob ar. Entalpias de fusão são também descritas, com base nos resultados de DSC.

Thermal decomposition of some chemotherapic substances

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

Síntese e caracterização do sistema ZrO2-SiO2 com adição de cobalto para uso como pigmentos cerâmicos

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