Accessibility Tools
CAMERINI, C. G.; PSUJ, G. ; CHADY, T. ; REBELLO, J. M. A. (2011).
Resumo: An eddy current method was applied to evaluate amount of sigma phase in duplex stainless steel. In the preliminary experiments several transducers configuration were considered. The performance of the transducers were verified utilizing samples having different amount of sigma phase. The configurations presenting the greatest possibility of evaluation of sigma phase were chosen for further experiments. In this paper a dedicated transducer operating in differential mode will be presented. The results will be shown and discussed.
LOPES, R. T. ; Lima, Inaya de ; PEREIRA, G. R. ; PÉREZ, C. A. (2011).
Resumo: Synchrotron X-ray imaging systems with fluorescence techniques was developed for biomedical researches in Brazilian Synchrotron Laboratory. An X-ray fluorescence microtomography system was implemented to analyse human prostate and breast samples and an X-ray microfluorescence system was implemented to study bone sites of human and animal samples with and without bone disorders.
SILVA, E. F.; Siqueira, Leonardo J.A. ; Alves, Wagner A. (2011).
Resumo: Hydrogen bonding between pyridazine (PRD) and formamide (FA) molecules has been investigated both experimentally by Raman spectroscopy on their binary mixtures and theoretically by DFT calculations on various gas-phase PRD:FA clusters. The band at 1160 cm−1 of PRD was used for the first time as a marker for monitoring the degree of complexation. Upon dilution with FA, a new band at 1169 cm−1 is observed and attributed to hydrogen-bonded PRD. The Raman experiments were complemented by DFT calculations and the corresponding structures, vibrational spectra and binding energies were determined. The most stable species were found to be the 1:2 PRD:FA complexes and such stoichiometry is in excellent agreement with the experimental determination. The shift to higher frequency observed to the prominent modes of PRD may be related to a shortening of the NC and CC bonds, upon complexation, which causes a decrease in the electron delocalization in PRD ring.
PEREIRA, G. R.; ROCHA, H. S. ; CALZA, C. ; Anjos, M. J. ; Lima, I. ; PÉREZ, C. A. ; LOPES, R. T. (2011).
Resumo: An X-ray Transmission Microtomography (CT) system combined with an X-ray Fluorescence Microtomography (XRFμCT) system was implemented in the Brazilian Synchrotron Light Laboratory (LNLS), Campinas, Brazil. The main objective of this work is to determine the elemental distribution in biological samples (breast, prostate and lung samples) in order to verify the concentration of some elements correlated with characteristics and pathology of each tissue observed by the transmission CT. The experiments were performed at the X-Ray Fluorescence beamline (D09B-XRF) of the Brazilian Synchrotron Light Laboratory, Campinas, Brazil. A quasi-monochromatic beam produced by a multilayer monochromator was used as an incident beam. The sample was placed on a high precision goniometer and translation stages that allow its rotation as well as translation perpendicular to the beam. The fluorescence photons were collected with an energy dispersive HPGe detector placed at 90° to the incident beam, while transmitted photons were detected with a fast Na(Tl) scintillation counter placed behind the sample on the beam direction. The CT images were reconstructed using a filtered back-projection algorithm and the XRFμCT were reconstructed using a filtered back-projection algorithm with absorption corrections. The 3D images were reconstructed using the 3D-DOCTOR software.
