Tortoiseshell or Polymer? Spectroscopic Analysis to Redefine a Purported Tortoiseshell Box with Gold Decorations as a Plastic Box with Brass

The study and preservation of museum collections requires complete knowledge and understanding of constituent materials that can be natural, synthetic, or semi-synthetic polymers. In former times, objects were incorporated in museum collections and classified solely by their appearance. New studies, prompted by severe degradation processes or conservation-restoration actions, help shed light on the materiality of objects that can contradict the original information or assumptions. The selected case study presented here is of a box dating from the beginning of the 20th century that belongs to the Portuguese National Ancient Art Museum. Museum curators classified it as a tortoiseshell box decorated with gold applications solely on the basis of visual inspection and the information provided by the donor. This box has visible signs of degradation with white veils, initially assumed to be the result of biological degradation of a proteinaceous matrix. This paper presents the methodological rationale behind this study and proposes a totally non-invasive methodology for the identification of polymeric materials in museum artifacts. The analysis of surface leachates using 1H and 13C nuclear magnetic resonance (NMR) complemented by in situ attenuated total reflection infrared spectroscopy (ATR FT-IR) allowed for full characterization of the object s substratum. The NMR technique unequivocally identified a great number of additives and ATR FT-IR provided information about the polymer structure and while also confirming the presence of additives. The pressure applied during ATR FT-IR spectroscopy did not cause any physical change in the structure of the material at the level of the surface (e.g., color, texture, brightness, etc.). In this study, variable pressure scanning electron microscopy (VP-SEM-EDS) was also used to obtain the elemental composition of the metallic decorations. Additionally, microbiologic and enzymatic assays were performed in order to identify the possible biofilm composition and understand the role of microorganisms in the biodeterioration process. Using these methodologies, the box was correctly identified as being made of cellulose acetate plastic with brass decorations and the white film was identified as being composed mainly of polymer exudates, namely sulphonamides and triphenyl phosphate.

Histórias de vida e formação de professores/as: diálogos entre Brasil e Portugal

A presente tese problematiza a formação de professores/as, buscando sentidos de uma racionalidade instituinte que incorpore a vida dos sujeitos, em toda sua complexidade existencial, como componente fundamental do processo formativo. Num contexto de investigação-formação, tomamos as biografias educativas de seis professoras do Primeiro Ciclo do Ensino Básico, em Portugal, e seis dos primeiros anos do Ensino Fundamental, no Brasil como uma alternativa teórico-metodológica na tematização da vida como espaço/tempo de formação. No desenvolvimento, encontramos vestígios de que o processo formador se torna inteligível numa perspectiva que entretece os diferentes episódios em tessitura, onde as intrigas são articuladas na experiência narrativa. Reafirmamos, também, o sentido da docência como "lugar de memória", a contribuição do registro da história de vida, transformando biografia em herança e a perspectiva dialógica da aprendizagem que se dá quando nos confrontamos com o outro de quem, dialecticamente, nos ligamos e nos distanciamos, mediados por desejos e desafios. ### Abstract - The present thesis discusses the formation of teachers, looking for senses of a founding rationality that incorporates the life of individuals in all its existential complexity as a fundamental component in the formation process. In an investigation-formation context, we took the educational biographies of six teachers from Portuguese Elementary Schools, and six teachers from Brazilian Elementary Schools, as a theoretical-methodological alternative on the theme of life as space/time of formation. In the development, we find indications that the formation process becomes comprehensible under a perspective that interlaces different episodes, where the intrigues are articulated in the experience narrative. We also reassert the teaching sense as being "the memory place", the registry contribution of life history, converting biography into legacy, and the learning dialogical perspective that happens when we confront ourselves with the other, from whom, dialectically speaking, we are close to and far-off, mediated by longings and challenges.