This work presents the development of a macro X-ray fluorescence (MA-XRF) scanner system for in situ analysis of paintings. The instrument was developed to operate using continuous acquisitions, where the module with the X-ray tube and detector moves at a constant speed, dynamically collecting spectra for each pixel of the artwork. Another possible configuration for the instrument is static acquisitions, where the module with the X-ray tube and detector remains stationary to acquire spectra for each pixel. The work also includes the analytical characterization of the system, which incorporates a 1.00 mm collimator that allows for a resolution of 1.76 mm. Additionally, the study presents the results of the analysis of two Brazilian paintings using this instrument. The elemental maps obtained enabled the characterization of the pigments used in the creation of the artworks and materials used in restoration processes.

This work aims to characterize the elemental concentrations of two banana types gold and silver. In both were analyze in the pulp and peel by X-Ray Fluorescence technique. The results showed that the elements in both types are more concentrated in the peel than in the pulp. In addition, it was also observed that the normalization of the peel and pulp concentrations for the elements K, Fe, Zn, Br, Rb, and Sr is higher in the silver banana compared to the gold banana. The results indicate that banana peels can be used to supplement nutritional deficiencies. The work also demonstrates the potential that X-Ray Fluorescence has in investigation of elemental composition of foods. As the technique has easy instrumentation and data interpretation, it can be implemented as a routine in the investigation of the elemental composition of foods. In addition, the technique has the advantage of carrying out in situ analyzes by portable instruments. These in situ investigations can even be applied to make quality control of bananas at the time of harvest.

O movimento circular uniforme é um fenômeno intrigante ao senso comum de quem o estuda pela primeira vez, em decorrência da resultante de forças mantenedora do movimento estar direcionada perpendicularmente à direção do movimento em cada instante da trajetória. Neste trabalho, com a ajuda das Tecnologias da Informação e Comunicação (TICs), destacamos como esse fato pode ser mitigado à luz da ideia proposta por Isaac Newton de discretizar o movimento circular de uma partícula em um movimento poligonal intermediado por infinitas colisões. Além da visualização das trajetórias, por meio das simulações, para ilustrar a transição entre o movimento poligonal discreto e o circular contínuo, mostramos que o comportamento da velocidade angular da partícula ao longo do polígono traz uma assinatura da referida transição.

In this work, we studied the correlation properties of seismic networks by analyzing the assortativity of worldwide and synthetic earthquake networks. We used data from the World Earthquake Catalog for the period from 2002 to 2016, considering earthquakes with magnitude thresholds 4.5 and 5.0. Shallow earthquakes (a depth of up to 70 km) and deep earthquakes (a depth greater than 70 km) were analyzed separately. Synthetic data were produced from simulations using a modified version of the Olami-Feder-Christensen model, which can reproduce several statistical characteristics of actual earthquakes. The study was carried out for two methodologies of connections between the network elements, where the correlation measures were calculated for all networks. The results for shallow earthquakes and synthetic data indicate: assortative correlation (locations with similar seismic activities tend to have a greater number of connections between them); mainshocks induce other mainshocks in both close and further away regions; the structure found has a type of “attracting dynamics”, where the places with a more intense seismic activity produce large numbers of connections in other locations around them. Deep earthquake networks are neutral and therefore do not have an explicit correlation type. Our findings agree with previous works for specific areas and contribute to better understand correlations between seismological regions.