3,373 research outputs found

    Agro-food industry residues for biodiesel production: BIOFFA project

    Get PDF
    The aim of the project BIOFFA is to develop processes for the production of biofuels from residual raw-materials with high free fatty acid (FFA). In technological terms, two distinct approaches, leading to different final products, are being assessed: production of fatty acid methyl esters (FAME) – biodiesel, and hydrogenated oil – H-oil. Different residues available in Portugal, including poultry fat, cattle fat, olive pomace oil and used frying oils, were collected and characterised, and the objectives of the project will be considered to be met if it will be possible to produce mixtures of both biofuels (biodiesel + H-oil) similar to the nowadays commercially available formulas (biodiesel + petro-diesel) with the superior advantages of valorising residues and producing the overall mixture from biological materials

    Synthesis of 5H-pyrido[4,3-b]indole by a modification of Pomeranz-Fritsch isoquinoline synthesis.

    Get PDF
    5H-Pyrido[4,3-b]indole was obtained from 3-formylindole in 16% overall yield by Jackson and Shannon modification of the Pomeranz-Fristch isoquinoline synthesis. The final cyclisation occurred but the removal of the tosyl group and oxidation of the dihydrocompound was not efficient. Changes in the concentration of the acid catalyst gave 29% as the best yield for the last step. An NMR study of the cyclisation is described.Fundação para a Ciência e Tecnologia (FCT) and FEDE

    Ensino de Física no segundo segmento do ensino fundamental

    Get PDF
    Esta monografia tem como objetivo inserir o estudo da física no segundo segmento do Ensino Fundamental, trabalhando essencialmente a parte conceituai que aparece no cotidiano do aluno. Será feita uma análise do processo ensino – aprendizagem e da maneira que o professor lida com as mais diferentes realidades dos alunos. Este trabalho sugere que os mais diversos recursos didáticos e interdisciplinares (experimentos, simuladores) sejam usados para despertar o interesse dos estudantes

    Studies on the reaction of morita-baylis-hillman with indole and carbazole derivatives

    Get PDF
    Fundação para a Ciência e a Tecnologia (FCT)and FEDE

    New benzilidenimine and amido derivatives: evaluation of antioxidant activity

    Get PDF
    The use of compounds with antioxidant activity is expected to be useful for the treatment of diseases were active oxygen species and free radicals play an important role [1,2]. Phenolic antioxidants react with free radicals by a process that usually involves the transfer of a hydrogen atom, resulting in a stable phenolic radical [1,2]. Aromatic amines and imines also contain active hydrogen atoms (NH) and by analogy it is expected that these atoms can be transferred to free radicals behaving the aromatic amines and imines as antioxidants.Numerous methods can be applied to evaluate the potential use of a new compound as an antioxidant and both chemical and electrochemical methods have been developed with this purpose [3,4]. The use of electrochemical methods, in particular voltammetric techniques, provides information regarding its reducing power. In this work benzilidenoimine and amido derivatives, presented in figure 1 and 2 respectively, were synthesized and their potential use as antioxidants was evaluated by cyclic voltammetry. The structure–activity relationships of the synthesised compounds were investigated in order to understand how the different functionalities affect their antioxidant activity.info:eu-repo/semantics/publishedVersio

    Lung segmentation in CT scans of patients with lower respiratory tract infection: influence of respiratory physiotherapy

    Get PDF
    The goal of the study was to assess the effects of a respiratory physiotherapy intervention in the tracheobronchial tree (TBT) volume and lung function in patients with lower respiratory tract infection (LRTI). In this framework, a method for TBT segmentation in Computer Tomography (CT) images of patients with LRTI was implemented, allowing to obtain volumetric data and study their correlation with the lung function (spirometry) parameterspublishe

    Microalgae-bacterial granular sludge systems - on the road for more sustainable processes in the aquaculture sector

    Get PDF
    With population growth and stagnation of capture fisheries, the aquaculture sector has been challenged to achieve remarkable production targets to meet the ever-increasing fish demand. However, land-based aquaculture industries need to capture high water volumes from nearby water bodies to ensure an adequate production and, consequently, high wastewater volumes, containing organic carbon, nutrients, and often contaminants of emerging concern, are produced. If not properly handled, aquaculture effluents pose a threat to receiving aquatic ecosystems. The rapid expansion of these industries, facing the increased demand for food worldwide, is only possible if more sustainable practices are adopted. To face the current water shortages and protect water resources, the development of environmentally friendly treatment systems that allow water recirculation is of utmost importance. This work aimed to develop a microalgae-bacteria granular sludge system able to efficiently treat marine aquaculture effluents so they can meet the requirements for recirculation. A photo-sequencing batch reactor was inoculated with a phototrophic microbial consortium obtained from water streams in a marine aquaculture facility and was fed with wastewater mimicking marine aquaculture streams. The aggregation of the microbial biomass occurred rapidly and, on day-21, ca. 49% of the total reactor biomass was in the form of granules. The system exhibited high and stable organic carbon removal (>80%), even when florfenicol, an antibiotic widely used in aquaculture, was present in the wastewater. Concerning the nitrogen content, a high-chemical quality effluent was obtained, complying with ammonium, nitrite, and nitrate concentrations for water recirculation within a marine aquaculture farm, even in periods where florfenicol was present in the wastewater. In addition, the dissolved oxygen levels in the treated effluents where within the ideal range for fish growth thus reducing the need for oxygenation and, consequently, the farms operational costs. Additionally, the coexistence of microalgae and bacteria within the granules allowed to treat wastewater at low air flow rates potentially reducing the energy needed for system’s aeration. Microalgae-bacterial granular sludge systems can contribute for the aquaculture sector sustainability as they enable to reduce energy and water usage whilst ensuring environmental protection.info:eu-repo/semantics/publishedVersio

    Volatile composition and sensory properties of mead

    Get PDF
    Mead is a traditional beverage that results from the alcoholic fermentation of diluted honey performed by yeasts. Although the process of mead production has been optimized in recent years, studies focused on its sensory properties are still scarce. Therefore, the aim of this work was to analyse the sensory ttributes of mead produced with free or immobilized cells of the Saccharomyces cerevisiae strains QA23 and ICV D47, and to establish potential correlations with its olatile composition. In the volatile composition of mead, the effect of yeast condition was more important than the strain. In respect to sensory analysis, the most pleasant aroma descriptors were correlated with mead obtained with free yeast cells, independently of the strain. Both sensory analysis and volatile composition indicates that the most pleasant mead was produced by free yeast cells. Although this study has provided a significant contribution, further research on the sensory quality of mead is still needed.Portuguese Foundation for Science and Technology (FCT) through a PhD grant (SFRH/BD/45820/2008). This research was partially supported through the PTDC project (PTDC/AGR-ALI/68284/2006) awarded by the FCT. This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER-006684) and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by European Regional Development Fund under the scope of Norte2020 – Programa Operacional Regional do Norteinfo:eu-repo/semantics/publishedVersio

    Slow pyrolysis of cork granules under nitrogen atmosphere: by-products characterization and their potential valorization

    Get PDF
    ABSTRACT: Cork granules (Quercus suber L.) were slowly pyrolyzed at temperatures between 400-700 degrees C and under N-2 flow. While preserving its structure, some cells of the cork biochar became interconnected, allowing such carbon residue to be used as templates for manufacturing ceria redox materials. The pyrolytic char morphology was similar to that of the natural precursor. The produced cork biochar belonged to Class 1 (C > 60%) and possessed a high heating value of 32 MJ kg(-1). Other pyrolysis-derived compounds were identified and quantified through GC-FID and GC-MS analyses. The yield of gases released during cork pyrolysis was strongly dependent on the temperature used due to the thermal decomposition reactions involved in the degradation of cork. In particular, rising pyrolysis temperature from 500 to 700 T resulted in reducing the total hydrocarbon gases from 74 to 24 vol%. On the other hand, the yield of H-2 increased from 0 to 58% by increasing the pyrolysis temperature from 400 to 700 T. Due to the presence of suberin in cork, the composition and yield of bio-oil could be regulated by the pyrolysis temperature. Cork bio-oil was found to consist of long-chain hydrocarbons (from C11 to C24). The bio-oil resulting from the slow pyrolysis of cork residues is suitable as an appropriate feedstock for producing aliphatic-rich pyrolytic biofuels or as a source of olefms. Overall, the findings of this study suggest that Quercus suber L. could be a promising feedstock for biochar and biofuel production through the pyrolytic route and could contribute to the environmental and economic sustainability of the cork production industry.info:eu-repo/semantics/publishedVersio
    • …
    corecore