CDRsp - Artigos em revistas internacionais
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Browsing CDRsp - Artigos em revistas internacionais by Field of Science and Technology (FOS) "Ciências Naturais::Ciências Químicas"
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- Modeling and simulation of photofabrication processes using unsaturated polyester resinsPublication . Matias, João Manuel; Bartolo, Paulo; Pontes, António VilelaSeveral kinetic models have been proposed to simulate thermosetting cure reactions. The most complex models, based on a mechanistic approach of cure reactions, are developed based on the concepts of free radical polymerization and the mechanism of reactions with diffusion. However, mechanistic models are usually quite impractical for engineering purposes because of the difficulty in obtaining the model parameters. An alternative to these mechanistic models are the phenomenological models, formulated in terms of the degree of cure and much easier to apply. Phenomenological models have been largely used to study thermal-initiated cure reactions, although only few works used them to model the kinetics of ultraviolet-initiated cure reaction. This work proposes a photo-thermal-kinetic model to study the behavior of unsaturated polyester resins during ultraviolet-initiated cure reactions. The model considers samples with different amounts of initiator concentration and cure reactions performed under different ultraviolet light intensities. The model has been numerically solved using the finite element technique.
- Rheological behavior of alginate solutions for biomanufacturingPublication . Rezende, Rodrigo Alvarenga; Bartolo, Paulo; Mendes, Ausenda; Filho, Rubens MacielThe rheological behavior of alginate solutions were investigated for the optimal design of a biomanufacturing system to produce alginate structures for tissue engineering. Its rheological properties were determined by a rheometer through rotational and oscillatory I tests. Experimental results were used to model the alginate solutions characteristics. The findings suggest that alginate solutions undergo shear-thinning effects with increasing shear rates. It is also possible to observe that its loss modulus is higher than the storage modulus ones being both modulus dependent upon the frequency, which is a typical characteristic of dilute solutions.