Effect of Alternating Magnetic Field on the Fatigue Behaviour of EN8 Steel and 2014-T6 Aluminium Alloy

The application of an alternating magnetic field (0.54 T) was observed to lead to an improvement in the fatigue endurance and an increase in Vickers microhardness and tensile strength of both EN8 steel and AA2014-T6 alloy. Fractography using scanning electron microscopy showed evidence of more ductile fracture features after treatment in contrast to untreated samples. The results of X-ray diffraction indicated formation of more compressive residual stresses following treatment; while examination by transmission electron microscopy showed evidence of fewer dislocations. In the case of the AA2014-T6 alloy; GP zones were also generated by the alternating magnetic field. However; the temperature increase during the treatment was too low to explain these observations. The results were attributed to the non-thermal effect of the alternating magnetic field treatment that led to depinning and movement of dislocations and secondary precipitation of copper

Genetic diversity among 435 barley accessions based in morpho-agronomical characteristics under irrigation in the Brazilian savannah.

Abstract The success of barley (Hordeum vulgare L.) cultivation and its adaptation to cropping systems relies on the knowledge and utilization of existing variability in germplasm banks. The objective of this work was to analyse diversity among pre-selected barley accessions to organize a working collection and to identify genotypes for a breeding program for irrigated barley in the Brazilian Savannah. The field experiment was conducted under irrigation in Planaltina, DF, Brazil. The plant population consisted of 433 accessions plus BRS 180 and BRS 195 as checks. The accessions were evaluated using fifteen morpho agronomic descriptors, in which 11 quantitative and four discrete. The interpolated control design was used for the statistical analysis. A genetic distance matrix was calculated using Gower?s coefficient. From the matrix, a grouping analysis was conducted, using the optimizing Tocher method and the graphic dispersion distance. The genetic distances varied between 0.025 and 0.572, with a mean of 0.256. The accessions were distributed in 18 groups by the Tocher method, which was directly related to the graphic dispersion. The existing genetic divergence in the collection under study helped the definition of accessions in crossing blocks from breeding programs directed to the savannah environment

Diversidade genética em genótipos de girassol no cerrado do Distrito Federal.

Título em inglês: Genetic diversity in sunflower genotypes in the brazilian savanna at Distrito Federal

Parâmetros genéticos de girassol em três ambientes no cerrado do Distrito Federal.

Título em inglês: Genetic parameters of sunflower in three enviroments in savanna of Distrito Federal

Education and inequality in Finland, Spain and Brazil

Production of INCASI Project H2020-MSCA-RISE-2015 GA 691004Finland, Spain and Brazil are three very internally complex and heterogeneous realities, with contradictions and permanent reforms to their education systems. In a first quantitative approach each country can be placed in a continuum of the education system that goes from most successful in terms of reaching a high level of education all across the population, in conditions of equity and facilitating youths' incorporation into the labour market, to least successful, with Finland and Brazil occupying either end of the spectrum respectively and Spain occupying an intermediate situation. Although there are differences, they share certain tensions in their respective education systems. On the one hand, about the conception of education, ranging from more utilitarian, human capital theories, to the more humanist and civic-minded perspective. On the other hand, the challenge of comprehensiveness between an academic and a vocational path. In addition, there is also the challenge of improving the education level of the population while also improving equality. The tensions differ from country to country, since their education traditions and cooperation and conflict strategies between the education agents, with varying levels of resources and different alliances with political actors vary, as does the social consensus

A agricultura além da produção de alimentos.

O presente documento apresenta os principais resultados do desenvolvimento de uma metodologia para avaliação do nexus A-A-E que demonstra o impacto da agrofloresta, proteção de nascentes e recuperação de áreas de proteção permanente e rotação de pastagens nas seguranças alimentar, hídrica e energética. O caso de estudo foi o município de Rio Claro, no estado do Rio de Janeiro, localizado no entorno do reservatório de Ribeirão das Lages, importante manancial para abastecimento de água e geração de energia para a cidade do Rio de Janeiro

A review of vibration-based structural health monitoring with special emphasis on composite materials

Copyright 2008 Elsevier B.V., All rights reserved.Structural health monitoring and damage detection techniques are tools of great importance in the off-shore, civil, mechanical and aeronautical engineering communities, both for safety reasons and because of the economic benefits that can result. The need to be able to detect damage in complex structures has led to the development of a vast range of techniques, of which many are based upon structural vibration analysis. In the present article, some of the latest advances in Structural Health Monitoring and Damage Detection are reviewed, with an emphasis on composite structures on the grounds that this class of materials currently has a wide range of engineering applications. FOREWORD-It should be noted that this review is not intended to be a general, all-encompassing review covering the whole range of structural health monitoring (SHM); it was planned as the starting point for a study focusing on damage detection, localization and assessment for certain kinds of structure. Thus, the line of thought behind the search and the structure of this review is a result of objectives beyond the scope of the paper itself. Nevertheless, it was considered that, once the above was understood, an updated synopsis such as this could also be useful for other researchers in the same field.Peer reviewe

Improvement of the wear resistance of nickel-aluminium bronze and 2014-T6 aluminium alloy by application of alternating magnetic field treatment

The present work has used an alternating magnetic field treatment at ambient temperature to improve the wear resistance of nickel-aluminium bronze and aluminium alloy 2014-T6. Pin-on-disc wear tests under lubricating conditions using a AISI52100 steel ball bearing as the counter face material have shown reduction in the width and depth of wear scars as well as lower values of the coefficient of friction following the treatment. The improved wear properties have been attributed to increased precipitation of κIV in the case of the nickel-aluminium bronze and of GP zones as well as ’’ for AA2014-T6. Transmission electron microscopy also revealed changes in the dislocation distribution, while X-ray diffraction showed changes in the residual stress for both alloys. The mechanism leading to these changes is discussed by consideration of the soft ferromagnetic properties of the nickel-aluminium bronze and the paramagnetic nature of AA2014