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Toe caps are one of the most important components in safety footwear, but have a significant contribution to the weight of the shoe. Efforts have been made to replace steel toe caps by polymeric ones, since they are lighter, insulated and insensitive to magnetic fields. Nevertheless, polymeric solutions require larger volumes, which has a negative impact on the shoe’s aesthetics. Therefore, safety footwear manufacturers are pursuing the development of an easy, low-cost and reliable solution to optimize this component. In this work, a solid mechanics toolbox built in the open-source computational library, OpenFOAM®, was used to simulate two laboratory standard tests (15 kN compression and 200 J impact tests). To model the polymeric material behavior, a neo-Hookean hyper-elasto-plastic material law with J2 plastic criteria was employed. A commercially available plastic toe cap was characterized, and the collected data was used for assessment purposes. Close agreements, between experimental and simulated values, were achieved for both tests, with an approximate error of 5.4% and 6.8% for the displacement value in compression and impact test simulations, respectively. The results clearly demonstrate that the employed open-source finite volume computational models offer reliable results and can support the design of toe caps for the R&D footwear industry., This work was funded by FEDER funds through the COMPETE 2020 Programme and National Funds through FCT-Portuguese Foundation for Science and Technology under the projects UIDB/05256/2020; UIDP/05256/2020 and FAMEST-Footwear, Advanced Materials, Equipment’s and Software Technologies (POCI-01-0247-FEDER-024529).

Dissertação de Mestrado Integrado em Medicina Veterinária A análise do líquido cefalorraquidiano (LCR) é um meio complementar de diagnóstico importante na abordagem a doenças que afetem o sistema nervoso central (SNC). As alterações encontradas no LCR, muitas vezes, auxiliam na exclusão de diagnósticos diferenciais, embora raramente sejam indicativas de um diagnóstico definitivo. A citometria de fluxo (CF) é um método analítico que permite a avaliação qualitativa e quantitativa de múltiplos parâmetros celulares, sendo cada vez mais utilizada em medicina veterinária, especialmente nos campos da imunologia e hematologia. Esta dissertação teve como objetivo estudar a distribuição das populações de leucócitos através da análise de amostras de LCR, e de sangue periférico, por CF, no sentido de avaliar alterações no LCR no decorrer de doenças do SNC. Serão apresentados três casos clínicos, nos quais foram obtidas as percentagens das principais populações de leucócitos (neutrófilos, monócitos/macrófagos e linfócitos) e das subpopulações de linfócitos, nomeadamente, linfócitos B, T auxiliares e T citotóxicos. Em cada caso, ocorreu uma inversão da subpopulação de linfócitos T predominante, entre o sangue periférico e o LCR, que poderá estar associada a doença. Nas amostras de sangue periférico, a percentagem de linfócitos T CD4+ excedeu a de linfócitos T CD8+, sendo esta, por sua vez, a predominante no LCR. Os resultados sugerem que a análise de LCR por CF pode fornecer informação complementar relevante ao diagnóstico de doenças do SNC, dando espaço a novas aplicações para a CF em medicina veterinária. ABSTRACT - CLINICAL IMPORTANCE OF CEREBROSPINAL FLUID ANALYSIS IN DOGS – SEVERAL ANALYTICAL METHODS IN VETERINARY MEDICINE - Cerebrospinal fluid (CSF) analysis is an important complementary diagnostic procedure available for the diagnosis of central nervous system (CNS) diseases. Despite of rarely providing a definitive diagnosis, CSF changes can often help to narrow down the list of differential diagnoses. Flow cytometry is an analytical method that allows qualitative and quantitative assessment of multiple parameters of individual cells. This technology has become routinely used in veterinary medicine, particularly in immunology and hematology. This dissertation aimed to study the distribution of leukocytes through the analysis of CSF and peripheral blood samples by flow cytometry assessing its importance in the diagnosis of CNS diseases. Three clinical cases will be presented, in which the percentage of the main populations of leukocytes (neutrophils, monocytes/macrophages and lymphocytes) and lymphocytes subtypes, namely B, T helper and T cytotoxic lymphocytes were obtained. In each case, there was an inversion of the predominant T lymphocyte subtype between peripheral blood and CSF, which may be associated with disease. In the peripheral blood samples, the percentage of CD4+ T lymphocytes exceeded the CD8+ T lymphocytes, which was the predominant subtype in CSF. The results suggest that the CSF analysis by flow cytometry can provide additional relevant information to the diagnosis of CNS diseases, giving space for new applications for flow cytometry in veterinary medicine. N/A

Generally, current clinical imaging methods do not provide highly detailed information about location of axonal injury, severity of injury or expected recovery of patients with traumatic brain injury (TBI). High-Definition Fiber Tractography (HDFT) is a novel imaging modality that allows visualizing and quantifying, directly, the degree of axons damage, predicting functional deficits due to traumatic axonal injury and loss of cortical projections. This imaging modality is based on diffusion technology. Being a novel modality, validation and quality control are essential. Thus this study aims at the development of a brain phantom to mimic the human brain in order to fill some gaps that currently exist in this area. This paper is focused on this novel imaging approach, the role of brain phantoms on its validation and the quality control, as well as, on the materials used in their construction. Furthermore, some important characteristics of fibrous materials for brain phantom are also discussed.

The high potential of polymer nanocomposites has attracted the interest of both industrial and scientific communities. The final properties of these materials depend not only on the characteristics of the matrix and nanofillers, but also on the degree of dispersion of the nanofiller in the polymeric matrix. There are different methods to promote the dispersion of nanofillers in polymeric matrices, but the most promising is based on melt mixing, where the dispersion is achieved through the application shear and elongational stresses on a mixture of the polymer melt and nanofiller, usually performed on complex mixing devices. In order to improve the knowledge of the phenomena involved in the melt mixing process, several research groups are developing on/in‐line adequate monitoring techniques, among these the online rheometry has shown to be a suitable choice. This work presents a new accessory conceived for a previously developed automated on‐line rheometry system, which allows to couple easily the rheometer to any extruder. The developed system was subsequently used to study the effect of some process parameters related to the melt mixing process, which evidences the adequacy of these tools for monitoring purposes.

On‐line rheometers are generally inserted between extruder and die and generate data that is typically utilized for quality control purposes. However, on‐line rheometers have also the potential to detect changes in structure, morphology, or composition of a given material system, thus assisting materials research and processing optimization, if they can be used along the axis of the extruder or compounder. The authors have previously developed on‐line capillary and rotational/oscillatory rheometers that can be inserted and used at specific locations along the extruder. Since these devices are operated manually, their manipulation may be cumbersome and data may lack reliability. This work presents new versions of these rheometers, with improved functionalities and motorizessd operation. Details on the validation of one of them is also given.

The achievement of an even flow distribution is one of the main tasks of the profile die design procedure. For this purpose there are two different alternative strategies, namely those that involve or not modifications of the die land cross section. As shown in previous works [1], those alternative strategies show different sensitivities to variations of the process parameters and material rheology, leading to the production of profiles with different tendency to distort in use. Additionally, it is well‐known that some of the problems faced during the production of a new profile arise in the manufacturing stage of the die flow channel and are related with inaccuracies associated to the machining equipment used. These inaccuracies affect the final flow channel geometry and are unavoidable, but are not taken into account during the design stage. In this work an in‐house 3D numerical modeling code based on the finite volume method is used to study the effect of slight dimensional variations (similar to those arising in the machining stage) on the performance of extrusion dies designed with the above referred strategies.s

This work is focused on the first step of the extrusion blow moulding process as part of a global optimisation process encompassing several steps: optimisation of the part thickness, optimisation of the parison thickness that will guarantee the specified thickness profile and optimisation of the extrusion conditions (namely, the sequence of the die mandrel movements) required to obtain the optimal parison thickness distribution. A high density polyethylene (HDPE) extrusion blow moulded tamper evident container was studied using a finite element based analysis (FEA) in order to determine the optimized thickness distribution required for the blown part, considering its mechanical specifications. Several tests corresponding to the requirements for UN homologation for dangerous substances transportation were performed using a commercial software. Non-linear models were used to better describe the mechanical part behaviour. The results obtained at this stage were used to redesign the blown part. In future work this optimised design will be used as an input for optimising the subsequent stages., One of the authors (R. P. Faria) acknowledges the support of the current work through a personal research grant offered by the Fundacao para a Ciencia e Tecnologia (ref. SFRH/BDE/15582/2006).

This work aims at the development of piezoelectric materials for flexible sensors produced with various geometries, at low cost and high production rates, adequate for the industrial scale. In particular the filament form, appropriate for integration into textiles, is described, but other geometries, such as tape, are also being studied. The filaments are produced by co-extrusion of multiple layers with piezoelectric and electrically conductive polymer composites., Fundação para a Ciência e a Tecnologia (FCT) - PTDC/CTM/108801/2008