Oxide surface modification: Synthesis and characterization of zirconia-coated alumina

Four aluminas were used as Supports for impregnation with a zirconium oxide with the aim to achieve a coating, without phase separation, between Support and modifier. The Supports were impregnated with different concentrations Of zirconium aqueous resin, obtained through the polymeric precursor method. After impregnation the samples were calcined and then characterized by XRD, which led to identification of crystalline zirconia in different concentrations from each support used. Using a simple geometric model the maximum amount Of Surface modifier Oxide required for the complete coating of a support with a layer of unit cells was estimated. According to this estimate, only the support should be identified below the limit proposed and crystalline zirconium oxide Should be identified above this limit when a complete coating is reached. The results obtained From XRD agree with the estimated values and to confirm the coating, the samples were also characterized by EDS/STEM, HRTEM, XPS, and XAS. The results showed that the zirconium oxide oil the Surface of alumina Support reached the coating in the limit of 15 Zr nm(-2), without the formation of the ZrO(2) phase. (c) 2009 Elsevier Inc. All rights reserved.

A New Insight on the Preparation of Stabilized Alpha-Nickel Hydroxide Nanoparticles

Nickel hydroxide can provide an outstanding cathode material in alkaline secondary batteries, however the progressive decrease of the charge capacity as a function of the number of oxidation/reduction cycles is a challenging problem to be solved. New improvements on the electrochemical properties of electrode materials can be achieved by exploiting the much better performance of alpha-nickel hydroxide. Such materials were obtained in a stable form by sol-gel method and characterized by thermogravimetric analyses, UV-Vis spectroscopy, X-ray diffractometry, scanning and transmission electron microscopy, cyclic voltammetry and electrochemical quartz crystal microbalance techniques. The results revealed not only the formation of the alpha-Ni(OH)(2) phase, but also a much better electrochemical reversibility and stability as compared with similar materials obtained by electrochemical precipitation method.

Evaluation of anti-inflammatory activity of derivatives from aerial parts of Baccharis uncinella

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

Validação de protocolo de assistência para pessoas com úlcera venosa na atenção primária

People with venous ulcers constitute as an important public health problem, its treatment is onerous and require assistance provided by trained professionals, systematized through protocols, however what lies in the assistance is that the management of this group of people differs from that preconized in the scientific literature, interfering with wound healing and quality of life of affected. In this sense, the construction of a assistance protocol specific to people with venous ulcers (VU) can help professionals of the Family Health Strategy both in patient assessment as and in establishment of quality assistance. Thus, this study aimed to analyse the validity of a multiprofessional assistance protocol for people with venous ulcers in primary care by health professionals using Delphi technique. This is a quantitative study, the methodological type conducted in two steps: first step related to integrative literature review to subsidize the development of the protocol, then these aspects were organized and proposed to the judges of the study through the Delphi technique. The study was initiated after approval by the Research Ethics Committee. The first step was performed between August and September 2012, in the virtual library of health, in the page of the Coordination of Improvement of Higher Education Personnel, of Municipal Health Secretariat and international guidelines of associations and in the subsequent step carried out between September 2012 to January 2013, was performed search by Lattes platform of the National Council of Technological and Scientific Development, in order to identify health professionals in Brazil who act as judges of the instrument and then, via online, the form was submitted to them.The sample for the second step was 51 judges in the first round and 35 for the second round Delphi. The analysis was done by adopting Kappa index ≥ 0.81 and Content Validity Index (CVI)> 0.80. In the first submission for the judges, items that did not reach Kappa and CVI established were: request / realization / test results, demographic data, medical history, risk factors, verification of pain / vital signs / pulse / infection signs / lesion location/ edema and pain treatment. After removal of items which have not obtained Kappa or CVI index established, it was found achieving optimal levels of these index for the categories. In the next step was the ressubmissão of protocol to judges through the Delphi technique in it was found that, of the 15 categories of the protocol, 12 presented higher scores in Delphi 2 phase and the other three categories remained the same Kappa and IVC of the previous phase. As for the average of evaluation requirements of the protocol was found that the scores assigned by the judges were higher in the second phase in nine of the 10 items, remaining the same in only one of the items indicating validity of the instrument before the consensus of the judges. Thus, we accepted the alternative hypothesis in this study, as they were obtained in the second Delphi phase the validity index greater than or equal to the Delphi 1 phase. The formulation of this assistance protocol valid and reproducible will enable a reorganization and redesign of assistance, with standardization of actions and continuity of care for persons with venous ulcers in primary health care

Computations of the flow past a still sphere at moderate reynolds numbers using an immersed boundary method

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Avrami exponent of crystallization in tellurite glasses

Nucleation process and crystal growth for three samples of the (20-x)Li(2)O-80TeO(2)-xWO(3) glass system were studied using X-ray diffraction and differential scanning calorimetry techniques. X-ray diffraction data confirmed the amorphous characteristic of the as-quenched samples and indicated the growth of crystalline phases formed due to the thermal treatment for annealed samples. These results reveal the presence of three distinct gamma-TeO(2), alpha-TeO(2) and alpha-Li(2)Te(2)O(5) crystalline phases in the TL sample, and two distinct alpha-TeO(2) and gamma-TeO(2) crystalline phases in the TLW5 and TLW10 samples. The activation energy and the Avrami exponent were determined from DSC measurements. The activation energy values X-ray diffraction data of the TLW10 glass sample suggest that gamma-TeO(2) phase occur before the alpha-TeO(2). The results obtained for the Avrami exponent point to that the nucleation process is volumetric and that the crystal growth is two or three-dimensional.

Thermal behavior of Cu-Al alloys near the alpha-Cu-Al solubility limit

The thermal behavior of Cu-Al alloys with 17, 19 and 21 at.%Al was examined by differential thermal analysis (DTA), differential scanning calorimetry (DSC), X-ray diffractometry (XRD), optical microscopy (OM) and scanning electron microscopy (SEM). The presence of the gamma phase (Al4Cu9) was clearly detected for the Cu-19 at.%Al alloy and caused the alpha (2) phase disordering process in two stages. The tendency to increase the alpha (2) dissolution precipitates with the increase in the Al content seems to be reverted for compositions at about 21 at.%Al and the heating/cooling ratio seems to influence the thermal response of this process. The presence of the endothermic peak corresponding to the beta (1)--> beta transformation depends on an incomplete beta decomposition reaction. The variation of the heating rate showed that the beta (1)-->(alpha+gamma (1)) decomposition is the dominant reaction for alloys containing 19 and 21 at.%Al.

Microspheres of alginate-chitosan containing isoniazid

Isoniazid was encapsulated into microspheres of alginate-chitosan by means of a complex coacervation method in an emulsion system. Since the encapsulation of isoniazid tends to be limited by its hydrophilic characteristics, this study proposes its microencapsulation by adsorption. The particles were prepared in three steps: (1) preparation of a W/O emulsion; (2) phase separation; and (3) adsorption of the drug. The isolated particles were placed in a solution of the drug under stirring to allow adsorption. The morphology and particle size were analysed by scanning electron microscopy (SEM). The isoniazid content was determined by extraction in 1 m phosphate buffer pH 7.5 under stirring for 4 h. Finally, the samples were filtered and analysed in an UV/VIS spectrophotometer at 260 nm. In vitro release tests were carried out in 0.05 m phosphate buffer pH 7.5. The results showed that microspheres of alginate-chitosan obtained were of spherical shape. The emulsion used for microparticle formation allows the preparation of particles with a narrow size distribution. The adsorption observed is probably of chemical nature, i.e. there is an ionic interaction between the drug and the surface of the particles.

Mutagenic and cytotoxic activity of an isocoumarin (Paepalantine) isolated from Paepalanthus vellozioides

A new isocoumarin with antimicrobial activity was isolated from Paepalanthus vellozioides (a native Brazilian plant) and called paepalantine. This study was carried out to assess the mutagenic activity of this new agent in assays with Salmonella typhimurium TA100, TA98, and TA102 and in Chinese hamster ovary (CHO) cell cultures, as well as cytotoxicity to McCoy cells. Paepalantine caused a significant dose-dependent increase in the frequency of revertants in the three strains used in the assay, both with and without S9 mix, in concentrations varying from 2 to 128 mu g/ plate. The mutagenicity was confirmed in assays with CHO cells treated in the G(1), S, and G(2) phases of the cell cycle. There was an increase in the chromosomal aberration frequency, mainly in the G(2) phase. Furthermore, the mitotic index of the treated cultures (40,80, and 160 mu g/ml) was significantly lower, indicating cytotoxicity. The midpoint cytotoxicity values to McCoy cells by the neutral red (NR) and microculture tetrazolium (MTT) techniques resulted in a NR50, and MTT50 of 30 and 38 mu g/ml, respectively. Alterations to the paepalantine structure are suggested to reduce its mutagenic and cytotoxic activity in investigations for its antineoplasic potential (C) 1997 Wiley-Liss, Inc.

Formation and characterization of soy bean oil/surfactant/water microemulsions

Pseudoternary phase diagrams, at 25 degrees C, were constructed for the systems soy bean oil (SBO)/surfactant/water, with single anionic sodium bis(2-ethylhexyl)sulfosuccinate (AOT), nonionic monoolein (MO) and mixtures of these surfactants, showing the isotropic phase of W/O microemulsions (MEs). The area of ME formation in the phase diagrams was shown to be dependent of the relative amount of surfactants, being larger for MO:AOT equals to 2:1. Rheological and dynamic light scattering (DLS) studies indicated that the viscosity of the isotropic ME phase exhibited two different behaviors depending on composition. The viscosity of dry MEs initially decreased with increasing amount of water following a dilution line in the phase diagram, i.e., a constant surfactant:SBO percentage ratio. As the water content increased the relative viscosity attained a minimum and then increased. This minimum could be related to the transition between two ME regions, L-2 and L'(2), having different characteristics. DLS measurements confirm the existence of ordinary W/O ME droplets in the L-2 region and suggest the existence of another structure in the L'(2) region. The size of the MEs droplets in L-2 phase ranges from 3.6 to 16.5 nm, depending on composition of SBO, surfactant and water. Small angle X-ray scattering (SAXS) also indicates the existence of structures with different characteristics, for the SAXS curves exhibit a typical micelle asymmetrical peak at low scattering vector q for MEs in L-2 but a symmetrical correlation peak at higher q vector in L'(2). (c) 2006 Elsevier B.V. All rights reserved.

The valuable role of renucleation rate in ultrananocrystalline diamond growth

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Investigação comparativa das propriedades estruturais do diboreto de magnésio dopado com compostos de carbono

Pós-graduação em Ciência e Tecnologia de Materiais - FC

Estudo da cinética da reação de decomposição da fase martensítica no sistema 'CUALMNAG'

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Caracterização geológica e estrutural da porção centro-norte do greenstone belt de Faina, Faina-GO

The area where the study was conducted is located in the central-western state of Goias. It geologically inserts the northern portion of the Greenstone Belt of Faina which belongs to the Archean terranes that fits in Brasília Fold Belt and Tocantins Structural Province. This region is known for its greenstone lode gold potential and it was heavily exploited by pioneers and prospectors, leaving many records for where they have been through. Preliminary work done by Orinoco Brasil Mineração in their required areas at the region showed that the environment is promising for gold mineralization and that the ore is controlled by structures. Therefore the objectives of this work were the geological and structural mapping in semi detail scale to improve geological, stratigraphic and structural controls present attributing possible ore understanding. With the development of the work there were recognized on the desktop three structural domains separated by a thrust fault. For each domain were discriminated the geological units ranging in gneisses, quartzites formed from coarse sediments arcoseanos, and schists. By mapping structures there were found five deformation phases, Dn-2, Dn-1, the Dn event that generated the main foliation (Sn) in high representation and two post-stages Dn with brittle late manifestations. The detail mapping of the Rattlesnake Gallery showed that the mineralized quartz vein is consistent with axial-plane foliation Sn-2 belonging to the oldest deformation Dn-2 phase and that the high grade is distributed in the hinge region folds of the same phase

A Family of Stationary Solutions to the Euler Equations and Generalized Solutions

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