A partir da publicação, em 1994, de um relatório que afirmava que a presença de óleos aromáticos pesados, com altos teores de compostos policíclicos, em formulações de borrachas estaria relacionada ao desenvolvimento de doenças como o câncer, associado ao fato da crescente conscientização ambiental na fabricação de produtos elastoméricos, foi iniciado um estudo sobre a substituição do óleo aromático de origem do petróleo por óleos vegetais de menor risco. Nessa Dissertação de Mestrado foi proposta a substituição do óleo aromático derivado do petróleo por óleos vegetais como o de tungue, palma e linhaça, em composições de borracha natural (NR) contendo diferentes teores do copolímero de butadieno-estireno (0, 10 e 50 phr) e diferentes tipos de carga (negro de fumo N330 e negro de fumo N375). As composições obtidas foram avaliadas quanto a propriedades reométricas, mecânicas e fractográficas. Foi observado que não houve variação significativa na viscosidade Mooney, na resistência à tração, no alongamento na ruptura e na dureza Shore das composições de NR SBR1502 quando o óleo aromático foi substituído pelos óleos vegetais, quando diferentes negros de fumo foram utilizados como carga reforçante e quando foram utilizados teores crescentes de SBR1502. Por outro lado, a resistência ao rasgamento das composições de NR SBR1502 apresentaram melhores resultados quando o negro de fumo N375 foi utilizado. A adição de teores crescentes de SR 1502 levou à diminuição dos valores de rasgo. A natureza do óleo utilizado influenciou esse resultado e melhores valores foram obtidos com o óleo de tungue. Os resultados obtidos foram corroborados pela morfologia do material, avaliadas por microscopia eletrônica de varredura

Na busca por condições otimizadas de operação/projeto de unidades de refino de petróleo, o conhecimento detalhado das propriedades físico-químicas das correntes de petróleo se faz necessário. No entanto, devido à sua imensa complexidade de composição, a caracterização analítica completa dessas correntes, apesar de tecnicamente possível, se configura em uma tarefa demorada e economicamente inviável. Nesse trabalho, utilizou-se modelos matemáticos da literatura para estimar as propriedades ponto de anilina (AP) e densidade 60ºF/60ºFde frações de querosene de aviação (QAV) e nafta. As análises laboratoriais dessas frações foram disponibilizadas do banco de dados BDEMQ/Petrobrás. Utilizando-se os parâmetros originais de 7 modelos para AP, nenhum deles foi capaz de reproduzir os dados experimentais do banco de QAV com compatibilidade de predição suficiente em relação ao método experimental ASTM D611. Para a densidade de QAV, foram utilizados 8 modelos de predição, e também nenhum deles foi capaz de reproduzir os dados experimentais com a reprodutibilidade do método experimental ASTM D4052. Para a fração de nafta, estimou-se os valores de densidade utilizando os mesmos 8 modelos de predição, e 7 modelos foram capazes de reproduzir os dados experimentais com compatibilidade de predição suficiente em relação ao método ASTM D4052 para frações de menor densidade. O desempenho estatístico dos modelos com seus parâmetros originais foi avaliado utilizando-se indicadores de desvio quadrático médio e de desvio médio (não-paramétricos), além de indicador complementar de modelo Distribuição F de Fisher (paramétrico). Os parâmetros de todos os modelos foram re-estimados a partir dos dados de propriedades básicas do banco BDEMQ/Petrobrás, e o desempenho estatístico dos modelos otimizados também foi avaliado. Para AP, mesmo com melhorias de predição para todos os modelos, nenhum modelo re-estimado foi capaz de reproduzir os dados do banco de QAV com compatibilidade de predição suficiente em relação ao método experimental. Da mesma forma, para densidade de QAV, a previsão dos modelos otimizados também não alcançou a reprodutibilidade prevista pelo método experimental. Para densidade de nafta, por sua vez, todos os modelos foram capazes de reproduzir com compatibilidade de predição suficiente os dados do banco. Finalmente, utilizando-se o método de reamostragem bootstrap não-paramétrico para avaliar o erro embutido no procedimento de re-estimação dos parâmetros, verificou-se tanto a sensibilidade dos parâmetros às variações das suas propriedades básicas, quanto à sensibilidade das funções objetivo às incertezas desses parâmetros. Para os modelos de AP re-estimados, todas as correlações matemáticas avaliadas apresentaram variações bastante estáveis nos desvios padrões dos seus parâmetros com o aumento do número de reamostragens. Com relação à sensibilidade de sua da função objetivo, somente 2 modelos mostraram alta sensibilidade às variações dos seus parâmetros. Para os modelos re-estimados de densidade, o método bootstrap permitiu verificar que apenas um mesmo modelo para os 2 conjuntos de dados não apresentou boa correlação com suas propriedades básicas. Quanto à sensibilidade de suas funções objetivo, somente um modelo apresentou elevada sensibilidade, tanto para QAV quanto para nafta. Todo o processamento dos dados do banco BDEMQ/Petrobrás foi realizado através de rotinas computacionais programadas e pacotes computacionais disponíveis na Linguagem R

The aim of this study was to evaluate the influence of thermal stress on the marginal integrity of restorative materials with different adhesive and thermal properties. Three hundred and sixty Class V cavities were prepared in buccal and lingual surfaces of 180 bovine incisors. Cervical and incisal walls were located in dentin and enamel, respectively. Specimens were restored with resin composite (RC); glass ionomer (GI) or amalgam (AM), and randomly assigned to 18 groups (n=20) according to the material, number of cycles (500 or 1,000 cycles) and dwell time (30 s or 60 s). Dry and wet specimens served as controls Specimens were immersed in 1% basic fuchsine solution (24 h), sectioned, and microleakage was evaluated under x40 magnification. Data were analyzed by Kruskal-Wallis and Mann-Whitney tests: Thermal cycling regimens increased leakage in all AM restorations (p

Micro injection moulding is a key process in the field of micro manufacturing especially in the production of medical devices. Micro injection molding technology involves the injection of the whole material with the result of a high degree of efficiency due to the material saving process. In comparison with conventional large injection moulding, the volume of material is very much reduced and as a consequence the flow and temperature profiles are considerable different to macro injection moulding. This work focuses on the impact on the structure, morphology and properties of parts prepared using micro injection moulding of these changes flow and temperature profiles. We have used small-angle X-ray Scattering techniques to evaluate the semicrystalline morphology and we have discovered that the nature of the process has led to changes in the morphology. We have supplemented the small angle scattering technique with wide-angle x-ray scattering as well differential scanning calorimetry.

Objectives: The new incremental step test (IST) is a field test that was developed for people with chronic obstructive pulmonary disease (COPD), based on the characteristics of the incremental shuttle walk test (ISWT); however, its measurement properties still need to be determined. We aimed, first, to assess the construct validity (through the comparison with the ISWT), within-day reliability and measurement error of the IST in people with COPD; and, second, to identify whether the participants have a learning effect in the IST. Design: Cross-sectional study, conducted according to COnsensus-based Standards for the selection of health status Measurement INstruments guidelines. Setting: A family health unit in Portugal, April 2022 to June 2023. Participants and analysis 63 participants (67.5±10.5 years) attended two sessions to perform two IST and two ISWT, separately. Spearman’s correlations were used to compare the best performances between the IST and the ISWT. Intraclass correlation coefficient (ICC2,1) was used for reliability, and the SE of measurement (SEM), minimal detectable change at 95% CI (MDC95) and Bland and Altman 95% limits of agreement (LoA) were used for measurement error. The learning effect was explored with the Wilcoxon signed-rank test. Results: The IST was significant and strongly correlated with the ISWT (0.72<ρ<0.74, p<0.001), presented an ICC2,1 of 0.95 (95% CI 0.92 to 0.97), SEM=11.7 (18.9%), MDC95=32.4 (52.2%) and the LoA were −33.61 to 31.48 for the number of steps. No difference was observed between the number of steps of the two attempts of the IST (p>0.05). Conclusions: The IST can be suggested as a valid and reliable test to assess exercise capacity in people with COPD, with no learning effect when two IST are performed on the same day. The measurement error of the IST is considered indeterminate.

The process of manufacturing with polymers usually involves shaping in the melt followed by a transition to the solid to preserve that shape and provide the required mechanical properties. The development of an understanding of those transitions is critical to the optimisation of materials and manufacturing technology. For synthetic polymers there are three key length scales in any phase transition such as crystallisation: the first involves the thin (~10nm) lamellar crystals, the second is the crystal planes in the unit cell (~1nm) and the third the regular local chain conformation (~0.1nm). We are using the extended Q range available with NIMROD at the ISIS Facility in the UK to obtain neutron scattering data which follows the transformation pathways of these three length scales simultaneously. We are using computational modelling procedures to analyse these data to develop a firm understanding of the multiscale processes involved in crystallisation. This paper describes the methodology and some of the experimental challenges using data drawn from this study. This work is part of the FCT funded programme UC4EP.

This study explores the effects of germination and cooking as pretreatments, followed by fermentation using different starter cultures on the physicochemical, nutritional, and techno-functional properties of Beluga and Du Puy lentil flours, focusing on reducing antinutritional factors and enhancing nutrient bioavailability. Fermentation was conducted using lactic acid bacteria (Furfurilactobacillus rossiae and Lactobacillus brevis) and a probiotic yeast (Saccharomyces boulardii) as starter cultures, individually and in combination. Results showed significant improvements in protein content, which increased by up to 38.4 g/100 g dry weight (dw) in Beluga lentils, and γ-tocopherol levels, which reached 8.15 mg/100 g dw after fermentation with L. brevis. Also, in Beluga lentils, germination followed by fermentation with F. rossiae and S. boulardii reduced carbohydrates to 57.7 g/100 g dw. Germination alone enhanced sucrose concentrations to 4.09 g/100 g dw and 4.44 g/100 g dw both Beluga and Du Puy lentils, respectively, while fermentation reduced its levels and promoted glucose production, reaching up to 1.02 g/100 g dw. Reduction in antinutritional factors was notable, with decreased phytic acid and condensed tannins concentration. Techno-functional properties such as water and oil holding capacity, and emulsifying capacity also improved significantly across treatments, enhancing the versatility of lentil flours in diverse food applications. These results highlight the potential of tailored processing techniques to enhance the physico-chemical profile of lentils, providing a foundation for their use in developing nutrient-dense, plant-based food products. Such innovations offer sustainable alternatives to traditional food sources, aligning with the growing demand for high-yield, environmentally friendly options.

In most cases the evaluation of properties, using any one of the following three basic methods of evaluation - comparative method, method of income and the cost method - the estimated market value obtained is similar. The changes in rural areas may lead to situations where there are substantial differences in estimates of the market value obtained by the use of different methodologies. This dissertation shows the two methods of assessment commonly referred to as comparative method and the income method, and illustrates its application to a case study - a residential property located in a rural area in the municipality of Alcobaça. With the use of two methods of evaluation, were obtained two estimates of the market value which have a statistically significant difference and confirm that, for the case examined, the differences in evaluation of properties resulting from the use of two methods of evaluation - Comparative method and method of income.------------------------------Na generalidade das situações de avaliação de imóveis, recorrendo a qualquer um dos três métodos básicos de avaliação – método comparativo, método do rendimento e método do custo – a estimativa do valor de mercado obtida é semelhante. As alterações verificadas no mundo rural poderão ter conduzido a situações em que existirão diferenças assinaláveis nas estimativas do valor de mercado obtidas pela utilização de diferentes metodologias. Na presente dissertação apresentam-se as duas metodologias de avaliação usualmente designadas como método comparativo e método do rendimento e exemplifica-se a sua aplicação a um caso prático – um imóvel habitacional situado em espaço rural no concelho de Alcobaça. Da utilização dos dois métodos de avaliação obtiveram-se duas estimativas do valor de mercado as quais apresentam uma diferença com carácter estatisticamente significativo e que confirma, para o caso prático analisado, a existência de diferenças na valorização dos imóveis resultantes da utilização de dois métodos de avaliação distintos – método comparativo e método do rendimento.

Tendon and ligament (T/L) engineering strategies towards clinical practice have been challenged by a paucity of understanding in the identification and still poorly described characterization of cellular niches. Prospecting how resident cell populations behave in vitro, and how cryopreservation may influence T/ L-promoting factors, can provide insights into T/ L-cellular profiles for novel regenerative solutions. Therefore, we studied human T/ L-derived cells isolated from patellar tendons and cruciate ligaments as suitable cellular models to anticipate tendon and ligament niches responses for advanced strategies with predictive tenogenic and ligamentogenic value. Our results show that the crude populations isolated from tendon and ligament tissues hold a stem cell subset and share a similar behavior in terms of tenogenic/ligamentogenic commitment. Both T/ L-derived cells successfully undergo cryopreservation/thawing maintaining the tenogenic/ligamentogenic profiles. The major differences between cryopreserved and fresh populations were observed at the gene expression of MKX, SCX, and TNMD as well as at the protein levels of collagen type I and III, in which cells from tendon origin (hTDCs) evidence increased values in comparison to the ones from ligament (hLDCs, pâ &lt;â 0.05). In addition, low-temperature storage was shown to potentiate an immunomodulatory profile of cells, especially in hTDCs leading to an increase in the gene expression of the anti-inflammatory factors IL-4 and IL-10 (pâ &lt;â 0.05), as well as in the protein secretion of IL-10 (pâ &lt;â 0.01) and IL-4 (pâ &lt;â 0.001). Overall, the outcomes highlight the relevance of the cryopreserved T/ L-derived cells and their promising immunomodulatory cues as in vitro models for investigating cell-mediated mechanisms driving tissue healing and regeneration.

The activities (at pH 7 and 50°C) of purified EGV (Humicola insolens) and CenA (Cellulomonas fimi) were determined on cotton fabrics at high and low levels of mechanical agitation. Similar activity measurements were also made by using the core domains of these cellulases. Activity experiments suggested that the presence of cellulose binding domains (CBDs) is not essential for cellulase performance in the textile processes, where high levels of mechanical agitation are applied. The binding reversibilities of these cellulases and their cores were studied by dilution of the treatment liquor after equilibrium adsorption. EGV showed low percentage of adsorption under both levels of agitation. It was observed that the adsorption/desorption processes of cellulases are enhanced by higher mechanical agitation levels and that the binding of cellulase with CBD of family I (EGV) is more reversible than that of CBD of the cellulase of family II (CenA).