Os mitos de origem no Salazarismo - o passado como se fora presente

(Excerto) As formas simbólicas existem na cultura, umas vezes de um modo discreto, outras vezes de um modo secreto, e ainda, noutros casos, de um modo ostensivo. A minha proposta é a de tomar as formas simbólicas em que consistem o messianismo e o sebastianismo na cultura portuguesa como mitos de origem no salazarismo e de os encarar como uma presença ostensiva na cultura durante o Estado Novo. Por messianismo e sebastianismo quero dizer essa "arte" peculiar de ser português, ou então esse "enigma", um "imaginário profundo", que compreende, nas palavras do antropólogo Gilbert Durand, quatro grandes grupos míticos: "a nostalgia do impossível", "o fundador vindo de fora", "o salvador oculto" e "a transmutação dos atos".

Properties and thermal behavior of natural deep eutectic solvents

Natural deep eutectic solvents (NADES) have shown to be promising sustainable media for a wide range of applications. Nonetheless, very limited data is available on the properties of these solvents. A more comprehensive body of data on NADES is required for a deeper understanding of these solvents at molecular level, which will undoubtedly foster the development of new applications. NADES based on choline chloride, organic acids, amino acids and sugars were prepared, and their density, thermal behavior, conductivity and polarity were assessed, for different NADES compositions. The NADES studied can be stable up to 170 Â°C, depending on their composition. The thermal characterization revealed that all the NADES are glass formers and some, after water removal, exhibit crystallinity. The morphological characterization of the crystallizable materials was performed using polarized optical microscopy which also provided evidence of homogeneity/phase separation. The conductivity of the NADES was also assessed from 0 to 40 Â°C. The more polar, organic acid-based NADES presented the highest conductivities. The conductivity dependence on temperature was well described by the Vogelâ Fulcherâ Tammann equation for some of the NADES studied.

Prefácio: Declinar a vibração da vida

[Excerto] A pedra de toque desta obra de Albertino Gonçalves é a vertigem, uma repentina névoa do olhar que o leva a perder nitidez, associada a um ligeiro desequilíbrio que complica os movimentos, baralhando os gestos e as acções humanas. O sociólogo cujo olhar, por natureza epistemologicamente calculado e vigiado, se deixe tentar pela vertigem deste desequilíbrio humaniza todavia o conhecimento, aproximando-o da condição humana e das figuras que a exprimem, não apenas a ambivalência e o desassossego, mas também o enigma e o labirinto. A vertigem é um desequilíbrio presente nas circunstâncias, no aleatório e nas emoções. É um desequilíbrio presente na intensidade precária das relações, nas variações dos sentimentos amorosos, no estremecimento dos corpos diante da sua disformidade ou declínio, e também da sua exuberância, enfim, nas incoerências ideológicas e nas mobilidades existenciais e profissionais. Como figura de conhecimento social, a vertigem alude à falta de garantias no caminho que nos leva ao outro, e também às escolhas e aos riscos das nossas ligações, hoje bem mais marcadas pela ambivalência do que pelas ideias de projecto, plano de carreira, grandes objectivos e planificação da vida a longo prazo.

Fundamental studies on natural deep eutectic solvents: physico-chemical, thermal and rheological properties

When combined at particular molar fractions, sugars, aminoacids or organic acids a present a high melting point depression, becoming liquids at room temperature. These are called Natural Deep Eutectic Solvents – NADES and are envisaged to play a major role on the chemical engineering processes of the future. Nonetheless, there is a significant lack of knowledge of its fundamental and basic properties, which is hindering their industrial applications. For this reason it is important to extend the knowledge on these systems, boosting their application development [1]. In this work, we have developed and characterized NADES based on choline chloride, organic acids, amino acids and sugars. Their density, thermal behavior, conductivity and polarity were assessed for different compositions. The conductivity was measured from 0 to 40 °C and the temperature effect was well described by the Vogel-Fulcher-Tammann equation. The morphological characterization of the crystallizable materials was done by polarized optical microscopy that provided also evidence of homogeneity/phase separation. Additionally, the rheological and thermodynamic properties of the NADES and the effect of water content were also studied. The results show these systems have Newtonian behavior and present significant viscosity decrease with temperature and water content, due to increase on the molecular mobility. The anhydrous systems present viscosities that range from higher than 1000Pa.s at 20°C to less than 1Pa.s at 70°C. DSC characterization confirms that for water content as high as 1:1:1 molar ratio, the mixture retains its single phase behavior. The results obtained demonstrate that the NADES properties can be finely tunned by careful selection of its constituents. NADES present the necessary properties for use as extraction solvents. They can be prepared from inexpensive raw materials and tailored for the selective extraction of target molecules. The data produced in this work is hereafter importance for the selection of the most promising candidates avoiding a time consuming and expensive trial and error phase providing also data for the development of models able to predict their properties and the mechanisms that allow the formation of the deep eutectic mixtures.