Browsing by Issue Date, starting with "2019-09-16"
Now showing 1 - 7 of 7
Results Per Page
Sort Options
- Utilização de jatos confluentes verticais de impacto em sistemas AVACPublication . Pastola, Juvenaldo Edi Chicra; Conceição, E. Z. E.O presente projeto de investigação numérica e experimental foi desenvolvido no sentido de avaliar a utilização de jatos confluentes verticais de impacto nos sistemas AVAC (Aquecimento, Ventilação e Ar condicionado). A parte da investigação numérica foi feita através de modelos numéricos de simulação e a parte investigação experimental foi feita através de ensaios experimentais numa câmara experimental sem ocupação equipada com um sistema de jatos confluentes verticais de impacto. Na investigação experimental foram feitos ensaios de medição de velocidades do ar a jusante da saída do jato e ao nível do chão. A velocidade do ar obtida experimentalmente a jusante da saída do jato foi usada como dado de entrada na simulação numérica e os resultados experimentais de velocidade do ar obtidas ao nível do chão do foram usados para comparar com o modelo numérico usado nas simulações. Foram também feitos ensaios de visualização do comportamento do escoamento na câmara através da técnica de injeção de fumo e visualização com recurso a emissão laser. Na investigação numérica foram usados modelos numéricos de simulação que permitem calcular as variáveis de conforto térmico, qualidade de ar interior, consumo de energia e índice de distribuição de ar. A investigação numéria foi feita numa câmara virtual com características geométricas idênticas da câmara experimental, ocupada com quatro manequins, uma mesa e quatro cadeiras. As temperaturas do ar interiores e exterior usadas na simulação foram de 20 ºC e 10 ºC para inverno e 25 ºC e 30 ºC para verão, respetivamente. A velocidade do ar na saída do jato foi de 8,41 m/s. Os resultados mostraram que o conforto térmico é melhor no inverno do que no verão e a qualidade de ar interior é melhor no verão do que no inverno, mas para ambas situações inverno e verão são valores aceitáveis. O consumo energia é melhor no verão do que no inverno. O índice de distribuição de ar é melhor na situação de inverno do que na situação de verão. Os resultados experimentais e numéricos de velocidade do ar usados para comparar os modelos numéricos mostraram uma boa concordância. De modo geral os resultados de simulação numérica mostraram a viabilidade de utilização do sistema de jatos confluentes verticais de impacto nos sistemas AVAC.
- Biodegradation of fluoxetine and 17á-ethinylestradiol by bacteria isolated from a wastewater treatment plant processPublication . Shylova, Anastasiia; Costa, Maria Clara; Palma, Tania Cristina da LuzThe increasing development of drugs such as antidepressants and hormones led to serious environmental and health problems, becoming mandatory to study different ways to remove a selective serotonin re-uptake inhibitor like fluoxetine (FLX) and estrogens like 17α- ethinylestradiol (EE2) during the wastewater treatment process. The study was carried out by using activated sludge samples from the Faro Northwest wastewater treatment plant (WWTP) to isolate bacteria under aerobic conditions in order to test their resistance in the presence of FLX and EE2 and investigate the biodegradability of chosen pharmaceuticals. In the present study, the identification of bacterial isolates was performed by sequencing the 16S rRNA gene of the obtained resistant bacteria. The obtained isolates which showed the ability to grow in the presence of 20 and 50 mg/L FLX were Pseudomonas putida, Enterobacter ludwigii, Pseudomonas nitritireducens, Alcaligenes faecalis, Pseudomonas aeruginosa, Pseudomonas nitroreducens and in the presence of 15 mg/L EE2 were Acinetobacter bouvetii, Acinetobacter kookii, Pantoea agglomerans Shinella zoogloeoides. These isolates were identified as FLX and EE2 degraders for the first time. FLX and EE2 biodegradation assays was performed in liquid medium. The results showed that for 20 mg/L FLX the bacterial isolate Pseudomonas nitroreducens displayed the highest removal efficiency of 55 ± 1% and for 15 mg/L EE2 Pantoea agglomerans removed 64 ± 4% of the drug. This research shows the importance of the involved bacteria for the effectiveness of the removal of these drugs in a wastewater treatment plant. A complete removal of pharmaceutical compounds from wastewater will stimulate water reuse, directing attention worldwide increasing requirements for clean and safe fresh water.
- Magnetic nanoparticles for biosensing and immunoprecipitationPublication . Beltran, Christian Hazael Perez; Costa, Ana M. Rosa da; Santander, José María PalaciosOur world is rapidly changing and its future is on our hands. Great effort is being done against overexploitation of natural resources, uncontrolled hunting and pollution. A great concerning fact is due to pollution which is causing a continuous greenhouse effect and new cancer cases every single day. Nowadays, it is possible to improve the detection of lethal elements in the environment, to fight against cancer in a smarter manner, with less pain and with more efficiency but, more important, to use the same low-cost, fast and environmentally friendly tool for these purposes and more. This reality is thanks to previous works and findings regarding the Magnetic Nanoparticles (MNPs), which are employable in a wide variety of applications such as magnetic recording media, resonance imaging, heavy metals ions removal and biomedicine (specifically in the hyperthermic treatment of malignant cells, site-specific drug delivery and separation of proteins and cell population). MNPs have special properties such as superparamagnetic, high field irreversibility, high saturation field, extra anisotropy contributions or shifted loops after field cooling, biocompatibility, long durability, low toxicity and cost. In this context, this project intends 1) to develop through a novel synthesis method, a biosensor capable to detect mercury in water by irreversible inhibition of the enzyme Horseradish Peroxidase attached onto the surface of different coated MNPs being able to approximate its detections to those limits stablished by the Environmental Protecting Agency of the United States of America; and 2) to use these high valuable nanoparticles as an immunoprecipitation vehicle through the attachment of a polyclonal antibody onto the surface of functionalized MNPs, selective against a suppressor protein. MNPs of about 10 nm were obtained within one minute via co-precipitation method enhanced by high power ultrasound. Experimental design has been used in order to optimize the preparation process from hours to just one minute. The composition, structure, size and morphology analyses of these MNPs have been carried out through X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetric analysis and scanning electron microscopy showing the correct achievement of the MNPs. Moreover, different coating agents have been tested in order to functionalize MNPs surface with the aim of attaching later biomolecules, such as enzymes and antibodies.
- Searching for innovative antitumoral drugs in marine microalgaePublication . Kamberovic, Farah; Barreira, Luísa; Viegas, CarlaCancer is one of the leading causes of death globally. Current available chemotherapeutics are aggressive and not specific to cancer cells, causing damage and death of healthy cells as well. As a consequence, the number of side-effects in patients arise. Another important therapeutic issue is the development of resistance and/or development of secondary malignancies. In some types of cancer, such as hepatocellular carcinoma (HCC) and acute monocytic leukaemia (AML), chemotherapy is associated with high mortality rate. This points out to the need to search and identify new sources of anti-cancer drugs with high selectivity and toxicity only for malignant cells, while conserving healthy cells. Marine microalgae are a rich source of different bioactive metabolites (e.g. poly-unsaturated fatty acids, carotenoids, polysaccharides, phenols, sterols, vitamins) with anti-inflammatory, anti-bacterial, anti-diabetic and anti-hypertensive properties, among others. During the past few years, marine microalgae have been featured in cancer research. In this research, we studied the cytotoxic effect of six selected microalgae species against adherent (HepG2) and suspended (THP-1) human cancer cell lines. The ethanolic extract of Phaeodactylum tricornutum was the most bioactive with an IC50 of 19.4±2.2 μg/mL for HepG2 cells. In addition, this extract was highly selective for HepG2 cells (SI=4.40) in comparison with a non-tumoural derived cell line (S17). The active extract was further subjected to bio-guided fractionation process to obtain four fractions: hexane, dichloromethane, ethyl-acetate and water with ethanol. Among these fractions, the dichloromethane fraction displayed high cytotoxicity towards both HepG2 and THP-1 cell lines with IC50 of 27.5±1.6 and 22.3±1.8 μg/mL, and selectivity of SI>4.54 and SI>5.60, respectively. In order to tentatively identify compounds responsible for the observable cytotoxic effect, the dichloromethane fraction was analysed by gas chromatography – mass spectrometry (GC/MS). Thirteen molecules with potential anti-cancer properties were identified, belonging to six different classes of metabolites: saturated fatty acids (SFA), polyunsaturated fatty acids (PUFAs), sterols, vitamins (dl-α-Tocopherol), phenols and terpenoid alcohols. The most abundant compounds detected were hexadecanoic acid, 9-hexadecenoic acid and 5,8,11,14,17-Eicosapentaenoic acid (EPA).
- Towards a better understanding of yacht cruisers profile for the purpose of a destination developmentPublication . Ilchuk, Kateryna; Marques, João Filipe; Pereira, Elsa Cristina SacramentoThe sea and its use are cross-cutting themes to the political, economic, social and environmental spheres. The uses of marine resources, in particular, the development of nautical tourism, are strategically imperative to Portugal. But this development will only be successful if based on scientific knowledge about the phenomenon. This project is thus presented as the first European research in the deepening of knowledge about yacht cruisers who use the Portuguese coasts. A special emphasis is given to the yachters entering and staying for some time at the marinas and boatyards of the Algarve. From the methodological point of view, this research is based on the primary source of the semi-structured interviews and used qualitative content analysis with the support of the NVivo 9. Yacht cruising, as a distinct niche market, is subjected mainly to senior travellers and their long-term holiday experience. Unlike other tourists, they require a minimum of specialized infrastructure and no accommodation at all. Their main needs are secure place for stops between trips, boat repair and maintenance, food and water supply. The policy makers interested in attracting yacht cruisers tourist category should provide separate facilities from other marine traffic, and by doing so, embrace a small-scale and sustainable form of tourism development which can bring some economic and social advantages to host communities.
- Marine microalgae as sources of bioactive compounds with anti-inflammatory actionPublication . Ismael, Kovan Mohammed; Barreira, Luísa; Viegas, Carla Alexandra São Bento; Simes, DinaInflammation is a defensive mechanism stimulated when the body is attacked by pathogens or irritants, or when cells are damaged. Sometimes, these defensive mechanisms can go wrong, emerging to different inflammatory diseases, such as acute inflammation and chronic inflammation. Despite the existence of several anti-inflammatory drugs on the market, new drugs with fewer side effects and higher efficacy are required for the treatment of inflammatory diseases. Attention has been given to natural bioactive compounds derived from marine organisms, since these are well known to be a source of potential bioactive compounds with different therapeutic applications in several diseases including inflammatory diseases. The aim of this research project was therefore to find compounds that can serve as new anti-inflammatory drugs or drug leads in microalgae. For that purpose, water, ethanol and ethyl acetate extracts of different microalgae species (Porphyridium sp., Nannochloropsis sp., Tetraselmis sp. CTP4, Isochrysis sp., Phaeodactylum tricornutum, Skeletonema costatum, Spirulina sp., Haematococcus pluvialis and Tetraselmis chuii) were characterized for its antioxidant activity as a pre-screening effort to select the most bioactive species/extracts. The most antioxidant extracts (ethanol extracts of Nannochloropsis sp., Tetraselmis sp. CTP4, and Tetraselmis chuii and water extracts of Nannochloropsis sp. and Porphyridium sp.) were afterwards screened for their anti-inflammatory activity measuring the inhibition of TNF-α production by LPS-stimulated human macrophage-differentiated THP-1 cells (Mac-THP-1). The best results were obtained with the ethanol extract of Tetraselmis sp. CTP4 (87% inhibition of TNF-α at 50 μg/mL in respect to the LPS control). This extract was therefore fractionated using liquid-liquid extraction (LLE), and the fractions were re-checked for their anti-inflammatory activity, using the previous method in a bioassay-guided fractionation effort. The most active fraction (the hexane fraction) was later analyzed by GC-MS to tentatively identify some of the compounds present in the fraction that could be responsible for its anti-inflammatory properties. Most of the compounds identified were fatty acids, some of which had already been reported to have anti-inflammatory properties. Further studies are needed to identify the exact compound or compounds responsible for the anti-inflammatory effect in the active fraction. Nonetheless, these results indicate that microalgae can be a source of compounds with the ability to minimize and reduce inflammation.
- Photovoltaic solar system for a smart bus shelter at Faro AirportPublication . Sousa, Nelson; Pires Rosa, Manuela; Baioa, Luís; Costa, CláudioIn this work, a photovoltaic system solution is studied for power-supply in an accessible and smart bus stop. In addition to lighting, the bus stop is equipped with a digital kiosk and a computer system to offer information to passengers and provide aid to people with reduced mobility. Several approaches in the integration of photovoltaic energy have been explored, demonstrating that the best solution is not a stand-alone system, but a smaller photovoltaic installation with the backing of the public power grid for periods of low photovoltaic production. The conclusions presented are based on economic analysis and environmental performance, particularly on avoided CO2 emissions, in order to ensure the sustainability of the recommended solution.