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One of the major challenges in the development of vibration-based structural health monitoring is the influence of environmental and operational parameters (EOPs) on damage-sensitive features (DSFs). With multiple methods already available in the literature, a challenge remains on the development of robust compensation methods when EOPs are partially measurable and noisy. Considering this limitation, this study proposes a novel environmental and operational variability (EOV) mitigation procedure based on the estimation of latent factors from available EOPs and DSFs to extract a comprehensive baseline model of DSFs. The obtained latent factors contain information on measured and un-measured sources of variation that can be used to infer noise-free estimates of the observed DSFs. In turn, the difference between measured and predicted DSFs is used as a robust damage indicator. In this work, the proposed methodology is applied in the form of an encoder-decoder architecture implemented via Principal Component Analysis (PCA) on Power Spectral Density (PSD) spectra extracted from vibration responses of a small-scale wind turbine blade. Two variations of the proposed method are considered, the first one considering only DSFs, and the second adding the ambient temperature as the single EOP. Our analysis demonstrates that the extracted latent factors are in both cases correlated with the temperature, and that the perfect damage detection performance can be achieved upon careful selection of the number of latent factors.

Resumo A obra O livro didático de Ciências no Brasil, organizada por Hilário Fracalanza e Jorge Megid Neto, foi publicada em 2006. Mais de 10 anos após sua publicação, algumas de suas proposições precisam ser reanalisadas, dadas as alterações sofridas pelo Programa Nacional do Livro Didático (PNLD), que geraram impacto nos próprios livros. Este trabalho compara enunciados dos capítulos do livro com guias do livro didático produzidos pelo Ministério da Educação, pesquisas sobre o livro didático de ciências e manuais escolares produzidos durante a vigência do PNLD. Em que pesem as desatualizações da obra de Fracalanza e Megid Neto, muitos de seus apontamentos permanecem válidos, embora necessitem ser relativizados à luz das complexas relações enunciativas em que se situam os manuais escolares atualmente.

En la excavación de la cueva de Ezkuzta (Azpeitia/Guipúzcoa; al nordeste del corredor cantábrico) se hallaron tres varillas aplanadas hechas en asta de cérvido (¿reno?). Dos de ellas están casi completas; se conservan fragmentos de una tercera. Sus fórmulas de decoración se corresponden con algunas de Isturitz y de otros sitios del Pirineo francés: son surcos espiraliformes o curvilíneos en dos de ellas e incisiones agrupadas en haces en la otra. Se consideran fósiles característicos del Magdaleniense medio pirenaico, entre aprox. 14500 y 13300 años BP. _____________________________________________ In the excavation of Ezkuzta’s cave (Azpeitia/Guipúzcoa; in northeastern Cantabrian corridor) three made smoothed rods (french. baguettes demi-rondes) of cervidae’s antler (reindeer?) were found: two completes and fragments of the third one. His formulae of decoration correspond with some of Isturitz and of other sites of the french Pyrenees: they are curvilinear or spiraliform ruts in two of them and fine lines grouped in faeces in other one. These themes are considered to be cultural markers of the Pyrenean middle Magdalenien, between aprox. 14500 and 13300 years BP.

Se presenta la industria lítica del único nivel de ocupación conservado en la cueva de Alkerdi, en el norte de Navarra, datado por C14 en 26470+530+490 años BP. Se aplica un análisis protocolario de la tecnología y la tipología de ese lote y se contextualiza en el complejo gravetiense del Pirineo occidental. Se concluye el carácter esporádico del uso del la cavidad y se argumenta su función preferente de alto de caza.