On the Dirac equation with PT-symmetric potentials in the presence of position-dependent mass

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Bound states of the Duffin-Kemmer-Petiau equation with a mixed minimal-nonminimal vector cusp potential

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Comment on Solutions of the Duffin-Kemmer-Petiau equation for a pseudoscalar potential step in (1+1) dimensions

It is shown that the paper Solutions of the Duffin-Kemmer-Petiau equation for a pseudoscalar potential step in (1+1) dimensions by Abdelmalek Boumali has a number of misconceptions

Real spectra for the non-Hermitian Dirac equation in 1+1 dimensions with the most general coupling

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Spin and pseudospin symmetries in the Dirac equation with central Coulomb potentials

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Use of lithium niobate detector for measuring X-ray intensity in mammographic range

A detector system that can measure X-ray intensity in the mammographic range of 22 to 36 kVp (equivalent photon energies ofthe beam between 11 and 15 keV) is presented. It consists of a lithium mobate detector and a high-sensitivity current-to-voltage converter.

Pyroelectric composite film for X-ray intensity detection

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

PZT FOR MEASURING ENERGY FLUENCE RATE of X-RAY USED IN SUPERFICIAL CANCER THERAPY

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

Heaviside generalized functions and shock waves for a Burger kind equation

The purpose of the work is to study the existence and nonexistence of shock wave solutions for the Burger equations. The study is developed in the context of Colombeau's theory of generalized functions (GFs). This study uses the equality in the strict sense and the weak equality of GFs. The shock wave solutions are given in terms of GFs that have the Heaviside function, in x and ( x, t) variables, as macroscopic aspect. This means that solutions are sought in the form of sequences of regularizations to the Heaviside function, in R-n and R-n x R, in the distributional limit sense.

Control aspects in nonlinear Hill's equation

The Hill's equations-even in the linear original version are a describer of phenomenon having chaotic flavor, giving sometimes very unusual situations. The theory of the so called intervals of instability in the equation provides the precise description for most of these phenomena. Considerations on nonlinearities into the Hill's equation is a quite recent task. The linearized version for almost of these systems it reduces to the Hill's classical linear one. In this paper, some indicative facts are pointed out on the possibility of having the linear system stabilizable and/or exactly controllable. As consequence of such an approach we get results having strong classical aspects, like the one talking about location of parameters in intervals of stability. A result for nonlinear proper periodic controls, is considered too. (C) 2010 Elsevier B.V. All rights reserved.

Síntese, sinterização e caracterização de ferrita de níquel

In this work we obtain nickel ferrite by the combustion synthesis method whcih involves synthesising in an oven at temperatures of 750oC, 950oC and 125oC. The precursors oxidizing used were nickel nitrate, ferric as an oxidizing and reducing urea (fuel). After obtaining the mixture, the product was deagglomerated and past through a 270 mesh sieve. To assess the structure, morphology, particle size, magnetic and electrical properties of nanoparticles obtained the samples were sintered and characterized by x-ray distraction (XRD), x-ray fluorescence spectroscopy (FRX); scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), vibrating sample magnetometer (MAV ) and electrical permittivity. The results indicated the majority of phase inverse spinel ferrite and Hematite secondary phase nickel and nickel oxide. Through the intensity of the distraction, the average size of the crystallization peaks were half-height width which was calculated using the Scherrer equation. From observing the peaks of all the reflections, it appears that samples are crystal clear with the formation of nanoparticles. Morphologically, the nanoferritas sintered nickel pellet formation was observed with three systems of particle size below 100mn, which favored the formation of soft pellets. The average size of the grains in their micrometric scale. FRX and EDS showed qualitatively the presence of iron elements nickel and oxygen, where through quantitative data we can observe the presence of the secondary phase. The magnetic properties and the saturation magnetization and the coercive field are in accordance with the nickel, ferrite where the curve of hysteresis has aspects of a soft material. Dielectric constant values are below 10 and low tangent loss

Análise preditiva da densidade mineral óssea em adolescentes brasileiros eutróficos do sexo masculino

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

Comparison of space analysis performed on plaster vs. digital dental casts applying Tanaka and Johnston's equation

OBJETIVO: comparar medidas de tamanhos dentários, suas reprodutibilidades e a aplicação da equação de regressão de Tanaka e Johnston na predição do tamanho dos caninos e pré-molares em modelos de gesso e digital. MÉTODOS: trinta modelos de gesso foram escaneados para obtenção dos modelos digitais. As medidas do comprimento mesiodistal dos dentes foram obtidas com paquímetro digital nos modelos de gesso e nos modelos digitais utilizando o software O3d (Widialabs). A somatória do tamanho dos incisivos inferiores foi utilizada para obter os valores de predição do tamanho dos pré-molares e caninos utilizando equação de regressão, e esses valores foram comparados ao tamanho real dos dentes. Os dados foram analisados estatisticamente, aplicando-se aos resultados o teste de correlação de Pearson, a fórmula de Dahlberg, o teste t pareado e a análise de variância (p < 0,05). RESULTADOS: excelente concordância intraexaminador foi observada nas medidas realizadas em ambos os modelos. O erro aleatório não esteve presente nas medidas obtidas com paquímetro, e o erro sistemático foi mais frequente no modelo digital. A previsão de espaço obtida pela aplicação da equação de regressão foi maior que a somatória dos pré-molares e caninos presentes nos modelos de gesso e nos modelos digitais. CONCLUSÃO: apesar da boa reprodutibilidade das medidas realizadas em ambos os modelos, a maioria das medidas dos modelos digitais foram superiores às do modelos de gesso. O espaço previsto foi superestimado em ambos os modelos e significativamente maior nos modelos digitais.

Analysis of failed commercially pure titanium dental implants: A scanning electron microscopy and energy-dispersive spectrometer X-ray study

Background: the failure of osseointegration in oral rehabilitation has gained importance in current literature and in clinical practice. The integration of titanium dental implants in alveolar bone has been partly ascribed to the biocompatibility of the implant surface oxide layer. The aim of this investigation was to analyze the surface topography and composition of failed titanium dental implants in order to determine possible causes of failure.Methods: Twenty-one commercially pure titanium (cpTi) implants were retrieved from 16 patients (mean age of 50.33 +/- 11.81 years). Fourteen implants were retrieved before loading (early failures), six after loading (late failures), and one because of mandibular canal damage. The failure criterion was lack of osseointegration characterized as dental implant mobility. Two unused implants were used as a control group. All implant surfaces were examined by scanning electron microscopy (SEM) and energy-dispersive spectrometer x-ray (EDS) to element analysis. Evaluations were performed on several locations of the same implant.Results: SEM showed that the surface of all retrieved implants consisted of different degrees of organic residues, appearing mainly as dark stains. The surface topography presented as grooves and ridges along the machined surface similar to control group. Overall, foreign elements such as carbon, oxygen, sodium, calcium, silicon, and aluminum were detected in failed implants. The implants from control group presented no macroscopic contamination and clear signs of titanium.Conclusion: These preliminary results do not suggest any material-related cause for implant failures, although different element composition was assessed between failed implants and control implants.

Perforated ray cells in the wood of roots and branches of cerrado species from Brazil

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