65 research outputs found
Empreendedorismo Social: Uma análise via associativismo juvenil
É atribuído ao empreendedorismo e aos empreendedores um conjunto de características cujo desenvolvimento tem sido considerado prioritário pelas autoridades públicas dos mais diferentes países. Não obstante o empreendedorismo na sua forma mais comum, i.e. ‘comercial’, estar relativamente bem estudado na literatura, o empreendedorismo social está ainda numa fase emergente, o que justifica a escassa evidência empírica existente sobre este fenómeno. Este artigo pretende contribuir para acrescentar evidência sobre esta realidade, avaliando, através de um inquérito alargado aos dirigentes da maioria das associações juvenis portuguesas, em que medida as associações dão um contributo efectivo para a criação e fomento de competências relacionadas com o empreendedorismo. Face aos dados recolhidos e aos resultados daí retirados, conclui-se que as associações juvenis desempenham um papel determinante no fomento das competências empreendedoras dos seus dirigentes. Demonstrámos, com base num modelo multivariável, que os dirigentes consideram que a sua participação no associativismo foi determinante na formação do seu perfil empreendedor. Em concreto, as atitudes empreendedoras estão positiva e significativamente associadas à percepção pelos dirigentes asociativos relativamente ao contributo das Associações no que concerne à promoção dos respectivos conhecimentos de gestão de organizações, do sistema legal e do funcionamento dos mercados. Os dirigentes ‘empreendedores’ reconhecem ainda que as Associações aumentaram a respectiva rede de contactos em termos de negócios/mercado, capacitando-os de um conjunto de conhecimentos mais vasto e de aplicabilidade prática do que qualquer disciplina que tenham frequentado no ensino formal. Em termos de implicações de política educativa, as conclusões reforçam a necessidade de existir uma maior integração entre uma abordagem formal e não formal de criação de competências teóricas e práticas no ensino do empreendedorismo aos mais diferentes níveis. Assim, o reconhecimento formal da experiência de gestão associativa como meio de enriquecimento curricular constituiria um avanço importante no espírito da futura implementação e adopção do Quadro Europeu das Qualificações.empreendedorismo social; associativismo juvenil; Portugal
The use of electronic nose as alternative non-destructive technique to discriminate flavored and unflavored olive oils
Cv. Arbequina extra virgin olive oils (EVOO) were flavored with cinnamon, garlic, and rosemary and characterized. Although flavoring significantly affected the physicochemical quality parameters, all oils fulfilled the legal thresholds for EVOO classification. Flavoring increased (20 to 40%) the total phenolic contents, whereas oxidative stability was dependent on the flavoring agent (a slight increase for rosemary and a decrease for cinnamon and garlic). Flavoring also had a significant impact on the sensory profiles. Unflavored oils, cinnamon, and garlic flavored oils had a fruity-ripe sensation while rosemary flavored oils were fruity-green oils. Fruit-related sensations, perceived in unflavored oils, disappeared with flavoring. Flavoring decreased the sweetness, enhanced the bitterness, and did not influence the pungency of the oils. According to the EU regulations, flavored oils cannot be commercialized as EVOO. Thus, to guarantee the legal labelling requirement and to meet the expectations of the market-specific consumers for differentiated olive oils, a lab-made electronic nose was applied. The device successfully discriminated unflavored from flavored oils and identified the type of flavoring agent (90 ± 10% of correct classifications for the repeated K-fold cross-validation method). Thus, the electronic nose could be used as a practical non-destructive preliminary classification tool for recognizing olive oils’ flavoring practice.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal)
for financial support by national funds FCT/MCTES to CIMO (UIDB/00690/2020) and to CEB
(UIDB/04469/2020) units and to the Associate Laboratory SusTEC (LA/P/0007/2020), as well
as to BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional
Development Fund under the scope of Norte 2020—Programa Operacional Regional do Norte. Nuno
Rodrigues thanks to National funding by FCT—Foundation for Science and Technology, P.I., through
the institutional scientific employment program-contractinfo:eu-repo/semantics/publishedVersio
Electronic nose coupled with linear and nonlinear supervised learning methods for rapid discriminating quality grades of superior java cocoa beans
An electronic nose (E-nose), comprising eight metal oxide semiconductor (MOS) gas sensors and a moisture-temperature sensor, was used for classifying three quality grades of superior java cocoa beans, namely fine cocoa dark bean 60%, and bulk cocoa bean that is a harder task compared to the discrimination of high versus low-quality cocoa beans. The E-nose signals were pre-processed using the maximum value method. The capability for discriminating the quality grade of the cocoa beans was checked by applying multivariate statistical tools, namely, linear discriminant analysis (LDA), support vector machine (SVM) and artificial neural networks (ANN). For this, the experimental dataset was split into two subsets, one for training (i.e., establishing the classification models) and the other for external-validation purposes. Furthermore, hyperparameter optimization and K-fold cross-validation variant were implemented during the model training procedure to select the best classification models and to avoid over-fitting issues. The best predictive classification performance was obtained with the E-nose-MLP-ANN procedure, which allowed 99% of correct classifications (overall accuracy) for the training dataset and 95% of correct classifications (overall accuracy) for the external-validation dataset. The satisfactory results clearly demonstrated that the E-nose could be applied as a quality control tool in the cocoa industry, requiring minimum and simple sample preparation. © Intelligent Network and Systems Society.The authors thank the Directorate of Research and Community Service, Ministry of Research,
Technology and Higher Education, the Republic of Indonesia for providing research grants of PTUPT
2019 (Contract No. 2688/UN1.DITLIT/DITLIT/LT/2019). The authors also like to acknowledge the financial support given by Associate Laboratory LSRE-LCM-UID/EQU/50020/2019, strategic
funding UID/BIO/04469/2019-CEB, BioTecNorte operation (NORTE-01-0145-FEDER-000004) and
strategic project PEst-OE/AGR/UI0690/2014 – CIMO, all funded by national funds through
FCT/MCTES (PIDDAC).info:eu-repo/semantics/publishedVersio
The electronic nose coupled with chemometric tools for discriminating the quality of black tea samples in situ
An electronic nose (E-nose), comprising eight metal oxide semiconductor (MOS) gas sensors, was used in situ for real-time classification of black tea according to its quality level. Principal component analysis (PCA) coupled with signal preprocessing techniques (i.e., time set value preprocessing, F1; area under curve preprocessing, F2; and maximum value preprocessing, F3), allowed grouping the samples from seven brands according to the quality level. The E-nose performance was further checked using multivariate supervised statistical methods, namely, the linear and quadratic discriminant analysis, support vector machine together with linear or radial kernels (SVM-linear and SVM-radial, respectively). For this purpose, the experimental dataset was split into two subsets, one used for model training and internal validation using a repeated K-fold cross-validation procedure (containing the samples collected during the first three days of tea production); and the other, for external validation purpose (i.e., test dataset, containing the samples collected during the 4th and 5th production days). The results pointed out that the E-nose-SVM-linear model together with the F3 signal preprocessing method was the most accurate, allowing 100% of correct predictive classifications (external-validation data subset) of the samples according to their quality levels. So, the E-nose-chemometric approach could be foreseen has a practical and feasible classification tool for assessing the black tea quality level, even when applied in-situ, at the harsh industrial environment, requiring a minimum and simple sample preparation. The proposed approach is a cost-effective and fast, green procedure that could be implemented in the near future by the tea industry.Ministry of Research, Technology and Higher Education of the Republic of Indonesia through a research scheme of PTUPT 2019 (Contract No. 2688/UN1.DITLIT/DIT-LIT/LT/2019). This work was also financially supported by strategic project UID/EQU/50020/2019—Associate Laboratory LSRE-LCM, strategic project PEst-OE/AGR/UI0690/2014–CIMO, strategic funding UID/BIO/04469/2019-CEB and BioTecNorte operation (NORTE-01-0145-FEDER-000004), all funded by European Regional Development Fund (ERDF) through COMPETE2020—Programa Operacional Competitividade e Internacionalização (POCI)—and by national funds through FCT—Fundação para a Ciência e a Tecnologia I.P.info:eu-repo/semantics/publishedVersio
As masterclasses internacionais em física de partículas em Portugal
Todos os anos, desde 2005, institutos de investigação e universidades de todo o mundo convidam estudantes do ensino secundário a experimentar a linha da frente da investigação fundamental. São as Masterclasses Internacionais em Física de Partículas, um programa do International Particle Physics Outreach Group (IPPOG) que oferece aos estudantes a oportunidade de serem cientistas por um dia, analisando dados reais recolhidos no acelerador LHC (Large Hadron Collider) do CERN, o Centro Europeu de Física de Partículas.
Em 2015, participaram nas Masterclasses estudantes de 42 países, recebidos em 210 universidades e laboratórios. A participação de países de todo o mundo reflete a internacionalização das colaborações em Física de Partículas. Os estudantes vivenciam este aspeto na videoconferência com que terminam o seu dia de pesquisa,
apresentando os resultados aos participantes de outros países, com a moderação de cientistas no CERN.
Portugal participa desde a primeira edição, com a colaboração do LIP - Laboratório de Instrumentação e Física Experimental de Partículas, promotor nacional da atividade, e o apoio da Agência Ciência Viva. Em 2014, cerca de dois mil estudantes e centena e meia de professores participaram nas Masterclasses organizadas em 13 instituições do ensino superior um pouco por todo o País: de Faro a Braga e de Bragança a Ponta Delgada, passando por Beja, Évora, Lisboa,
Covilhã, Coimbra, Aveiro, Porto e Vila Real. Foi ainda prestado apoio à realização das Masterclasses na Universidade de São Tomé e Príncipe.
A dimensão e o sucesso das Masterclasses em Portugal não são a regra na generalidade dos países europeus, tendo-se notado um crescimento acentuado desde o inicio da realização de Escola de Física no CERN para professores em língua portuguesa. Nos últimos anos, verifica-se que cerca de 20% dos participantes nas Masterclasses são portugueses.
Além da aquisição de conhecimentos ou da perceçâo do fascínio da investigação fundamental, aspetos como a cooperação internacional na ciência, a comunicação entre cientistas de diferentes línguas e culturas, ou a estreita relação de interdependência entre ciência fundamental e tecnologia, que o CERN tão bem representa, são aprendizagens a valorizar. Neste contexto, importa hoje sobretudo refletir sobre as formas de maximizar o ganho para todos os participantes
Bio-based solar energy harvesting for onsite mobile optical temperature sensing in Smart Cities
The Internet of Things (IoT) fosters the development of smart city systems for sustainable living and increases comfort for people. One of the current challenges for sustainable buildings is the optimization of energy management. Temperature monitoring in buildings is of prime importance, as heating account for a great part of the total energy consumption. Here, a solar optical temperature sensor is presented with a thermal sensitivity of up to 1.23% °C-1 based on sustainable aqueous solutions of enhanced green fluorescent protein and C-phycocyanin from biological feedstocks. These photonic sensors are presented under the configuration of luminescent solar concentrators widely proposed as a solution to integrate energy-generating devices in buildings, as windows or façades. The developed mobile sensor is inserted in IoT context through the development of a self-powered system able to measure, record, and send data to a user-friendly website.publishe
Factors affecting the transfer of learning to the workplace
Training aims to respond to the needs of development of individuals and organizations (Grohmann & Kauffeld, 2013). Based on Holton model, we carried out a study seeking to identify and understand the factors involved in the process of learning transfer to the workplace from two different training actions on the design and skills. The study took place at a Portuguese organization and involved 98 participants. Former students were interviewed with the purpose to explore the factors that facilitated or hindered the learning transfer, and the Inventory of the Portuguese version of the Learning Transfer System (Holton, Bates, Seyler & Carvalho, 1997; Velada & Caetano, 2009) was applied. The results suggest that the Holton model (2005) shows that the trainees have identified important issues for learning transfer and that there are differences in relation to the transfer factor pursuant to the type of training.info:eu-repo/semantics/publishedVersio
Assessment of table olives' organoleptic defect intensities based on the potentiometric fingerprint recorded by an electronic tongue
Table olives are prone to the appearance of sensory defects that decrease their quality and in some cases result in olives unsuitable for consumption. The evaluation of the type and intensity of the sensory negative attributes of table olives is recommended by the International Olive Council, although not being legally required for commercialization. However, the accomplishment of this task requires the training and implementation of sensory panels according to strict directives, turning out in a time-consuming and expensive procedure that involves a degree of subjectivity. In this work, an electronic tongue is proposed as a taste sensor device for evaluating the intensity of sensory defects of table olives. The potentiometric signal profiles gathered allowed establishing multiple linear regression models, based on the most informative subsets of signals (from 24 to 29 recorded during the analysis of olive aqueous pastes and brine solutions) selected using a simulated annealing meta-heuristic algorithm. The models enabled the prediction of the median intensities (R2 ≥ 0.942 and RMSE ≤ 0.356, for leave-one-out or repeated K-fold cross-validation procedures) of butyric, musty, putrid, winey-vinegary, and zapateria negative sensations being, in general, the predicted intensities within the range of intensities perceived by the sensory panel. Indeed, based on the predicted mean intensities of the sensory defects, the electrochemical-chemometric approach developed could correctly classify 86.4% of the table olive samples according to their trade category based on a sensory panel evaluation and following the International Olive Council regulations (i.e., extra, 1st choice, 2nd choice, and olives that may not be sold as table olives). So, the satisfactory overall predictions achieved demonstrate that the electronic tongue could be a complementary tool for assessing table olive defects, reducing the effort of trained panelists and minimizing the risk of subjective evaluations.This work was financially supported by Project POCI-01-0145-FEDER-006984—Associate Laboratory LSRE-LCM, by Project UID/QUI/00616/2013 —CQ-VR, and UID/AGR/00690/ 2013—CIMO, all funded by Fundo Europeu de Desenvolvimento Regional (FEDER) through COMPETE2020—Programa Operacional Competitividade e Internacionalização (POCI) and by national funds through Fundação para a Ciência e a Tecnologia (FCT), Portugal. Strategic funding of UID/BIO/04469/2013 unit is also acknowledged. Nuno Rodrigues thanks FCT, POPH-QREN, and FSE for the Ph.D. Grant (SFRH/BD/104038/2014).info:eu-repo/semantics/publishedVersio
Excesso de peso e obesidade abdominal em mulheres atendidas em Unidade da Estratégia Saúde da Família
Evaluation of extra-virgin olive oils shelf life using an electronic tongue-chemometric approach
Physicochemical quality parameters, olfactory and gustatoryretronasal positive sensations of extra-virgin olive oils vary during storage leading to a decrease in the overall quality. Olive oil quality decline may prevent the compliance of olive oil quality with labeling and significantly reduce shelf life, resulting in important economic losses and negatively condition the consumer confidence. The feasibility of applying an electronic tongue to assess olive oils usual commercial light storage conditions and storage time was evaluated and compared with the discrimination potential of physicochemical or positive olfactory/gustatory sensorial parameters. Linear discriminant models, based on subsets of 58 electronic tongue sensor signals, selected by the meta-heuristic simulated annealing variable selection algorithm, allowed the correct classification of olive oils according to the light exposition conditions and/or storage time (sensitivities and specificities for leave-one-out cross-validation: 8296 %). The predictive performance of the E-tongue approach was further evaluated using an external independent dataset selected using the KennardStone algorithm and, in general, better classification rates (sensitivities and specificities for external dataset: 67100 %) were obtained compared to those achieved using physicochemical or sensorial data. So, the work carried out is a proof-of-principle that the proposed electrochemical device could be a practical and versatile tool for, in a single and fast electrochemical assay, successfully discriminate olive oils with different storage times and/or exposed to different light conditions.The authors acknowledge the financial support from the strategic funding of UID/BIO/04469/2013 unit, from Project POCI-01-0145-FEDER-006984—Associate Laboratory LSRELCM funded by FEDER funds through COMPETE2020—Programa Operacional Competitividade e Internacionalização (POCI)—and by national funds through FCT—Fundação para a Ciência e a Tecnologia and under the strategic funding of UID/BIO/04469/2013 unit. Nuno Rodrigues thanks FCT, POPH-QREN and FSE for the Ph.D. Grant (SFRH/BD/104038/2014).info:eu-repo/semantics/publishedVersio
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