Browsing by Author "Costa, Joana"
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- Community Empowerment Assessment in a School of the North of Portugal - a qualitative studyPublication . Melo, Pedro; Costa, Joana; Moreira, Patrícia; Pinto, Carlos; Moura, Sandra; Freitas, Cláudia Telles de; Vieira, Margarida
- Comparative physico-chemical characterization of organic flours from wheat, rye and speltPublication . Sousa, Sérgio; Castro, Pedro; Costa, Joana; Bastos, Francisca Casanova; Dias, Ema; Gomes, AnaAim: There is an increasing consumer demand for healthier food products, such as cereal flours, free from pesticides and other contaminants. The production of organic cereals is therefore a solution that can be commercially explored. Moreover, consumers also highly appreciate and value the local production of cereals and flours. Hence, the aim of the current work was to characterize organic flours obtained from three distinct cereals, namely wheat, rye and spelt. The cereals were selected on the basis that they are able to be grown in Portugal as it presents favourable climatic conditions. Methods: Physico-chemical characteristics of each organic cereal flour, crucial for adequate processing, were analysed through distinct methodologies/technologies, such as falling number (enzyme activity), mastersizer (size distribution) and scanning electron microscopy (SEM; morphology), among several others. Results: Results showed that, among the three flours, wheat presented the highest falling number (350), which translates the enzymatic activity of α-amylase (being negatively correlated). Hence, the dough prepared with wheat flour will be harder than those obtained with the flours from the other cereals. Concerning size distribution of the flours’ granules, results showed bimodal distribution regarding wheat and rye flours, while spelt flour resembled a normal distribution. A maximum (peak) was observed for all flours between 20-30 μm, and a second peak was registered at 60 and 135 μm for wheat and rye, respectively. Those results, obtained utilizing a mastersizer, were further corroborated via SEM analysis. X-ray diffraction analysis provided information concerning cristalographic structure, which allowed to determine that the flour with lower cristalinity was rye. Since this characteristic decreases susceptibility to enzymes, it is inferred that rye flour will be the easiest to digest. Differencial scanning calorimetry (DSC) showed similar starch gelatinization temperature between the three flours, although in spelt flour the process was initialized at lower temperature. Fourier- transform infrared spectroscopy (FTIR) analysis revealed similar spectra, disclosing, as expected, the presence of starch and gluten. Conclusion: Knowledge on the physico-chemical properties of each particular organic cereal flour is crucial and must be considered when looking to select one to develop a specific food product.
- Cyberbullying, desempenho académico e comportamentos autodestrutivos no ensino superior portuguêsPublication . Costa, Joana; Pinto, Joana Carneiro; Francisco, RitaO cyberbullying é um tipo de agressão propositada e repetida que, recorrendo ao uso de meios tecnológicos, gera um desequilíbrio de poder. A literatura existente com amostras portuguesas foca-se maioritariamente no ensino básico e secundário, desvalorizando a sua existência e impacto nos estudantes universitários. Assim, pretende-se entender de que forma o cyberbullying se relaciona com o desempenho académico, a satisfação com a vida académica e os comportamentos autodestrutivos neste contexto. Participaram, nesta investigação, 255 estudantes, 207 (81,2%) do sexo feminino e 48 (18,8%) do sexo masculino. A média de idades é 21,03 (DP = 2,271). Não se verifica uma relação entre o cyberbullying e o desempenho académico, ao invés daquele e dos comportamentos auto-destrutivos que são desempenhados mais pelas vítimas. Verifica-se ainda que uma maior satisfação a nível interpessoal está associada a uma maior satisfação a nível da adaptação ao curso, a um menor nível de vitimização, a uma menor incidência de comportamentos auto-destrutivos e a uma menor auto-estima. Muitos dos estudantes não têm consciência do papel que desempenham no fenómeno, salientando-se a necessidade de implementar acções de sensibilização, prevenção e promoção de estratégias de coping e combate neste contexto.
- Evaluation of antioxidant, antimicrobial and prebiotic activities of a xylooligosaccharide-rich grape pomace extractPublication . Costa, Joana; Vilas-Boas, Ana; Pastrana, Lorenzo; Cabral, Lourdes; Pintado, Manuela
- High carbon load in food processing industrial wastewater is a driver for metabolic competition in aerobic granular sludgePublication . Paulo, Ana M. S.; Amorim, Catarina L.; Costa, Joana; Mesquita, Daniela P.; Ferreira, Eugénio C.; Castro, Paula M. L.Aerobic granular sludge (AGS) processes are among the most robust wastewater treatments. One of their greatest advantages is related to the granules multi-layered structure, which creates a protective barrier against organic shock loads and variable wastewater composition, particularly attractive for the treatment of industrial wastewater. However, when treating a wastewater with variable and complex composition, the difficulty in identifying factors that most affect a specific biological process increases. In this study, the effect of organic loading rate (OLR), namely carbon content, on nitrification in an AGS process treating fish canning wastewater was investigated. Besides process performance, also biomass structural changes, and microbial community composition were analysed. Reactor operation lasted for 107 days and was divided in three phases during which different OLR and C/N ratios were applied. A higher OLR was applied during the first two phases (ca. 1.1 and 1.5 kg COD m−3 day−1, respectively) compared to the third phase (between 0.12 and 0.78 kg COD m−3 day−1) and the C/N ratios also varied (ca. 4.4, 7.8, and 2.9, respectively). Throughout the operation, COD concentration in the outlet was lower than 100 mg O2 L−1. Nitrification was inhibited during the second phase and recovered afterwards. Principal component analysis (PCA) of quantitative image analysis (QIA) and performance data allowed to distinguish process changes over the three operational phases. During the first two phases, the decrease in the biomass robustness occurred, but recovered during the last phase, indicating that the high content of organic matter had possibly an effect on the aerobic granules structural characteristics. The composition of the AGS microbiome did not change substantially after the end of the higher OLR periods. The main microbial diversity shifts were mostly associated to adaptation to higher or lower carbon availability. Bacteria and inferred enzymes associated to nitrogen and phosphorous removal were identified. Chryseobacterium, a bacterium with high metabolic versatility, was able to adapt to the organic shock load, becoming dominant over operation. Despite the variable composition of the fish canning wastewater, carbon was identified as the main driver for nitrification inhibition, while promoting changes in the physical characteristics and on the microbial community of granules.
- Impact of industrial wastewater on aerobic granules morphology and nitrification process in bioreactorsPublication . Paulo, Ana M. S.; Costa, Joana; Amorim, Catarina L.; Mesquita, Daniela P.; Ferreira, Eugénio C.; Castro, Paula M.L.
- Impact of industrial wastewater on aerobic granules morphology and nitrification process in bioreactorsPublication . Paulo, Ana M. S.; Costa, Joana; Amorim, C. L.; Mesquita, Daniela P.; Ferreira, Eugénio C.; Castro, Paula M. L.Aerobic Granular Sludge (AGS) is an innovative wastewater treatment process used for carbon and nutrients removal from wastewater. Aerobic granules present a compact structure resistant to variable wastewater composition. Process disturbances might affect bacteria, especially those present in the granules outer layers, such as nitrifiers. In this study, fish canning wastewater with variable composition was treated for 107 days using an AGS sequential batch reactor. The operation was divided in 3 phases, according to different periods of organic loading rate (OLR): Phase I: 0.74 to 1.32 kg m-3 day-1; Phase II: 1.33 to 1.70 kg m-3 day-1; Phase III: 0.12 to 0.78 kg m-3 day-1. Carbon removal and nitrification performance were evaluated. Morphological and structural changes within granules were followed by quantitative image analysis (QIA). Principal component analysis (PCA) was performed using QIA data alone and relating QIA with reactor performance. Along the operation, carbon removal was stable, reaching less than 100 mg O2 L-1 at the outlet. Nitrification was inhibited during Phase II but recovered in Phase III. According to QIA data, biomass samples from Phase III clustered together, indicating higher granule stability. PCA analysis also revealed that a higher OLR might have led to a transitory loss of robustness during Phase II, recovered during Phase III. This study shows that OLR, nitrification process and biomass morphological and structural changes are possibly correlated during the treatment of industrial wastewater by AGS process.
- Life values and creativity in future psychologists and managers: what differences?Publication . Almeida, Leonor; Nogueira, Sara Ibérico; Nogueira, Alexandra; Costa, JoanaWith this study, we intend to describe comparatively the life values and the creative potential of 89 college students, 38 (42.7%) of Psychology and 51 (57.3%) of Management. The mean age is 20.16 years (SD = 3.133). The instruments used included the Life Values Inventory (Almeida, 2006) and the Test for Creative Thinking- Drawing Production (Ibérico Nogueira & Almeida, 2010), adapted for the Portuguese population. Considering the values variable, there are statistically significant differences in the values Achievement, Creativity, Economic Prosperity, Health and Responsibility in favor of future managers and Concern for Others in favor of future psychologists. Regarding the creativity levels there were not found statistically significant differences between the students of psychology and management. In fact, the average value of creativity is 18.62, well below the mean of the German population (31), the cultural context in which the TCT-DP was developed. No correlations were found between life values and creativity, except for Concern for Others, which negatively (and weakly) correlates with creativity (r = .23, p = .03). Considering the low levels of creative performance, it is important to alert to the need to promote, among students, the creative way of thinking, the generation of new ideas and the intention of assuming and risking a less conventional thinking style.
- Long-term stability of a non-adapted aerobic granular sludge process treating fish canning wastewater associated to EPS producers in the core microbiomePublication . Paulo, Ana M. S.; Amorim, Catarina L.; Costa, Joana; Mesquita, Daniela P.; Ferreira, Eugénio C.; Castro, Paula M. L.The tolerance of aerobic granular sludge (AGS) to variable wastewater composition is perceived as one of its greatest advantages compared to other aerobic processes. However, research studies select optimal operational conditions for evaluating AGS performance, such as the use of pre-adapted biomass and the control of wastewater composition. In this study, non-adapted granular sludge was used to treat fish canning wastewater presenting highly variable organic, nutrient and salt levels over a period of ca. 8 months. Despite salt levels up to 14 g NaCl L−1, the organic loading rate (OLR) was found to be the main factor driving AGS performance. Throughout the first months of operation, the OLR was generally lower than 1.2 kg COD m−3 day−1, resulting in stable nitrification and low COD and phosphorous levels at the outlet. An increase in OLR up to 2.3 kg COD m−3 day−1 disturbed nitrification and COD and phosphate removal, but a decrease to average values between 1 and 1.6 kg COD m−3 day−1 led to resuming of those processes. Most of the bacteria present in the AGS core microbiome were associated to extracellular polymeric substances (EPS) production, such as Thauera and Paracoccus, which increased during the higher OLR period. Ammonium-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB) species were detected in AGS biomass; while AOB were identified throughout the operation, NOB were no further identified after the period of increased OLR. Different polyphosphate-accumulating organisms (PAOs) were detected along the process: Candidatus Accumulibacter, Tetrasphaera and Gemmatimonas. A non-adapted granular sludge was able to treat the fish canning wastewater and to tolerate salinity fluctuations up to 14 g L−1. Overall, a high microbial diversity associated to EPS producers allowed to preserve bacterial groups responsible for nutrients removal, contributing to the adaptation and long-term stability of the AGS system.
- Optimization of hemicellulose extraction from sugarcane straw by autohydrolysisPublication . Pedrosa, Sílvia Santos; Neto, Tânia; Costa, Joana; Pintado, Manuela; Madureira, Ana Raquel