4 resultados para Formaldehyde-assisted isolation of regulatory elements
em Universidade do Minho
Resumo:
In Portugal, maize is the cereal that involves more agriculture explorations. Aspergillus spp., among other species, are usually associated with this cereal, during drying and storage, making this commodity susceptible to mycotoxins (such as aflatoxins, ochratoxins, and cyclopiazonic acid). The aim of this study was to evaluate the mycotoxigenic potential of isolated Aspergillus strains from these maize samples and correlate it with the sampling place, the weather conditions, and local practices during drying and storage. The samples were collected between November 2008 and April 2009 in maize association of producers facilities in Coimbra, Santarém and Portalegre. The isolated strains were divided in three distinct groups, Aspergillus section Flavi, Aspergillus section Nigri and others Aspergillus. The preliminary results show that there are differences between the incidence of these groups in the three sampling places, especially in Coimbra, probably due to a lower mean temperatures and higher humidity levels. These data will be presented and discussed.
Resumo:
The assessment of existing timber structures is often limited to information obtained from non or semi destructive testing, as mechanical testing is in many cases not possible due to its destructive nature. Therefore, the available data provides only an indirect measurement of the reference mechanical properties of timber elements, often obtained through empirical based correlations. Moreover, the data must result from the combination of different tests, as to provide a reliable source of information for a structural analysis. Even if general guidelines are available for each typology of testing, there is still a need for a global methodology allowing to combine information from different sources and infer upon that information in a decision process. In this scope, the present work presents the implementation of a probabilistic based framework for safety assessment of existing timber elements. This methodology combines information gathered in different scales and follows a probabilistic framework allowing for the structural assessment of existing timber elements with possibility of inference and updating of its mechanical properties, through Bayesian methods. The probabilistic based framework is based in four main steps: (i) scale of information; (ii) measurement data; (iii) probability assignment; and (iv) structural analysis. In this work, the proposed methodology is implemented in a case study. Data was obtained through a multi-scale experimental campaign made to old chestnut timber beams accounting correlations of non and semi-destructive tests with mechanical properties. Finally, different inference scenarios are discussed aiming at the characterization of the safety level of the elements.
Resumo:
Nowadays, there is an increasing interest in using fiber reinforced polymers (FRP) for strengthening masonry elements. It has been observed that these materials, when used for externally bonded reinforcement (EBR), improve the performance of masonry components. However, issues such as durability and long-term performance of strengthened elements are still open. The bond between composite material and masonry substrate is a critical mechanism in EBR strengthening techniques, and therefore its durability and long-term performance should be deeply investigated and characterized. In the present study, the influence of water immersion on the bond performance is investigated by performing single-lap shear bond tests on two sets of GFRP-strengthened specimens immersed in water for six months. Different surface preparation techniques are used for each set of specimens to study their effect on the bond degradation. The specimens are prepared following the wet lay-up procedure. The observations and the obtained results are presented and discussed.
Resumo:
The Supplementary Material for this article can be found online at: http://journal.frontiersin.org/article/10.3389/fmicb. 2016.00275