A crise política da Província de Goiás e o movimento separatista do Norte no período da independência do Brasil, 1820-1824

Dissertação de mestrado em História

Systematic design analysis and risk management on engineered nanoparticles occupational exposure

The production of nanotechnology-based products is increasing, along with the conscience of the possible harmful effects of some nanomaterials. The “safety-by-design” approaches are getting attention as helpful tools to develop safer products and production processes. The Systematic Design Analysis Approach could help to identify the solutions to control the workplace risks by defining the emission and exposure scenarios and the possible barriers to interrupt them. By applying this approach in a photocatalytic ceramic tiles development project it was possible to identify relevant nanoparticles emission scenarios and related barriers, and defining possible ways to reduce it.

Thermal characterization of polyhydroxyalkanoates and poly(lactic acid) blends obtained by injection molding

In this work we present the thermal characterization of the full scope of polyhydroxyalcanoate and poly(lactic acid) blends obtain by injection molding. Blends of polyhydroxyalcanoate and poly(lactic acid) (PHA/PLA) were prepared in different compositions ranging from 0–100% in steps of 10%. The blends were injection molded and then characterized by differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and wide angle X-ray diffraction (WAXD). The increment of PHA fraction increased the degree of crystallinity of the blend and the miscibility of the base polymers as verified by the Fox model. The WAXD analysis indicates that the presence of PHA hindered the PLA crystallization. The crystallization evolution trough PHA weight fraction (wf) shows a phase inversion around 50-60%. SEM analyses confirmed that the miscibility of PHA/PLA blends increased with the incorporation of PHA and became total for values of PHA higher that 50%.

Literacias na educação de adultos

[Excerpt] Apesar de muitas evidências em contrário (GRAFF, 1979; CARRINGTON; LUKE, 1997), nas sociedades contemporâneas está fortemente enraizada a convicção de que a prosperidade dos países depende de ‘níveis de literacia’ das populações. Com efeito, as “perspetivas económicas da literacia”, adotadas por muitos organismos e não apenas pelo discurso corrente, assumem que um dos indicadores de progresso é a literacia (por exemplo, UNESCO, 2006; DATAANGEL POLICY RESEARCH INCORPORATED, 2009). Na medida em que esta crença tende também a posicionar os indivíduos, sem ou com pouca escolarização, quase “como marginais” e “socialmente excluídos” (HAMILTON; PITT, 2011, p. 350), a sua “falta de literacia” constitui uma preocupação de políticas públicas dos governos, por exemplo da área da OCDE, traduzidas em mecanismos de monitorização, medidas e programas. Também a UNESCO (2006) tem assumido que o desafio que as questões de literacia colocam aos países só pode ser enfrentado se se aumentar a qualidade da educação primária e secundaria e se se intensificarem os programas explicitamente orientados para a literacia de jovens e adultos (UNESCO, 2006, p. 17). (...)

Photolabile protection for amino acids: studies on the release from novel benzoquinolone cages

The synthesis of a novel fused nitrogen heterocycle, benzoquinolone, for evaluation as a photocleavable protecting group is described for the first time, by coupling to model amino acids (alanine, phenylalanine and glutamic acid). Conversion of the phenylalanine ester conjugate to the thionated derivative was accomplished by reaction with Lawesson’s reagent. Photocleavage studies of the carbonyl and thiocarbonyl benzoquinolone conjugates in various solvents and at different wavelengths (300, 350 and 419 nm) showed that the most interesting result was obtained at 419 nm for the thioconjugate, revealing that the presence of the thiocarbonyl group clearly improved the photolysis rates, giving practicable irradiations times for the release of the amino acids (less than 1 minute).

Aminobenzocoumarinylmehtyl esters as photoactive precursors for the release of butyric acid

The evaluation of the photorelease of a carboxylic acid drug, using butyric acid as a representative model, was carried out by using 7-amino-4-chloromethyl-2-oxo-2Hnaphtho[1,2-b] pyran, an aminobenzocoumarin, and its mono- and di-methylated or ethylated derivatives. This study was intended to improve the release of butyric acid from benzocoumarins by the addition of an amino group to the heterocycle by applying the knowledge of second-generation coumarinylmethyl-based photoremovable protecting groups. Photolysis studies were performed on the resultant ester cages by irradiation in a photochemical reactor at 254, 300, 350 and 419 nm, using methanol/HEPES buffer 80:20 solutions as solvent. The data obtained showed that these new fluorescent aminobenzocoumarins are superior to all the previously tested benzocoumarins with the same or different ring fusions. As well as the photolysis, the photophysics of the compounds were characterised by both steady state and time-resolved methods.