Evaluation of three different approximations for the solution of the direct problem on electrical impedance tomography

Neste trabalho foram comparadas 3 diferentes soluções para o problema direto da tomografia de impedância elétrica utilizando o método das diferenças finitas. Nesta técnica são posicionados elétrodos no contorno/fronteira de um volume a ser estudado e, em 2 deles, são injetados padrões de correntes e, nos elétrodos restantes, realizadas medidas do potencial elétrico. A inversão numérica dos dados permite a reconstrução do domínio analisado. Duas novas aproximações são propostas para o problema direto e comparações são realizadas a partir de resultados disponíveis na literatura. Com o estudo aqui realizado, para uma das aproximações propostas foi observada uma melhora significativa da acurácia comparada aos resultados obtidos com a aproximação da literatura.The present study compares three different solutions for the direct problem of Electrical Impedance Tomography using the finite difference method. In this technique, electrodes are positioned on the boundary of a volume to be studied, and in two of them current patterns are injected and measurements of electrical potential are made in the remaining electrodes. The numerical inversion of the data allows reconstruction of the analyzed domain. Two new approximations are proposed for the direct problem and comparisons are performed based on results available in the literature. In the study performed here, in one of the proposed approximations it was observed a significant improvement in accuracy compared to results obtained with the approximations in the literature.Peer Reviewe

NEOTECTÔNICA NA BACIA DO ALTO RIO GRANDE: APLICAÇÕES EM SUA PORÇÃO MANTIQUEIRENSE

O trabalho tem por objetivo levar a efeito investigações acerca do quadro neotectônico vigente na bacia do alto Rio Grande em sua porção contida na Serra da Mantiqueira, sul de Minas Gerais. A discussão se pautou nos resultados obtidos por interpretações cartográficas, trabalhos de campo e mensuração dos seguintes índices geomórficos: Fator Assimetria de Bacias de Drenagem, Fator de Simetria Topográfica Transversal, Relação Declividade X Extensão do Curso, perfil longitudinal principais canais

Laser printing of silver-based micro-wires in ZrO2 substrate for smart implant applications

Smart implants are endowed with functions of sensing, actuating and control to solve problems that may arise during their use. The assembly of these functions along the implant surface is still a challenge. However, with the advent of 3D printing, it is possible to print on implants’ surface, communication channels or micro-antennas or even sensoric/actuating areas. Hence, a positive impact on the long-term performance of the implants (including hip, dental and knee) may be expected with the proposed approach. Despite titanium and Ti6Al4V titanium alloy are the standard choice for implants fabrication, 3Y-TZP (tetragonal 3% mol yttria-stabilized zirconia) has emerged as a ceramic material suitable to overcome titanium alloy problems, due to its numerous advantages. In this sense, this work is concerned with the ability of printing silver-based communication system in zirconia substrates by using laser technology. For this purpose, micro-cavities were created on ZrO2 substrate, where the silver powder was placed and sintered into them. Through the laser approach, silver-based wires with great quality and low resistivity values were achieved. The flexural strength results showed that the mechanical resistance of zirconia disks was affected by laser micro-wire printing, which decreased as the laser passage was performed. Based on the results, it is believed that the proposed approach seems to be effective for the manufacturing of implants with intrinsic capacities, useful for smart implant applications.This work has been supported by FCT (Fundação para a Ciência e Tecnologia - Portugal) in the scope of the projects UID/EEA/04436/ 2019 and NORTE-01-0145-FEDER-000018-HAMaBICo and Add.Additive_Manufacturing to Portuguese Industry_POCI-01-0247- FEDER-024533. Thank the CNPq (205791/2014-0) and CAPES for the financial support

The fraction of cancer attributable to ways of life, infections, occupation, and environmental agents in Brazil in 2020

Many human cancers develop as a result of exposure to risk factors related to the environment and ways of life. The aim of this study was to estimate attributable fractions of 25 types of cancers resulting from exposure to modifiable risk factors in Brazil. The prevalence of exposure to selected risk factors among adults was obtained from population-based surveys conducted from 2000 to 2008. Risk estimates were based on data drawn from metaanalyses or large, high quality studies. Population-attributable fractions (PAF) for a combination of risk factors, as well as the number of preventable deaths and cancer cases, were calculated for 2020. The known preventable risk factors studied will account for 34% of cancer cases among men and 35% among women in 2020, and for 46% and 39% deaths, respectively. The highest attributable fractions were estimated for tobacco smoking, infections, low consumption of fruits and vegetables, excess weight, reproductive factors, and physical inactivity. This is the first study to systematically estimate the fraction of cancer attributable to potentially modifiable risk factors in Brazil. Strategies for primary prevention of tobacco smoking and control of infection and the promotion of a healthy diet and physical activity should be the main priorities in policies for cancer prevention in the country. \ua9 2016 Azevedo e Silva et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited