33 research outputs found
Metodologias de cálculo das necessidades de aquecimento na ISO 13790
Tese de mestrado integrado em Engenharia da Energia e do Ambiente, apresentada à Universidade de Lisboa, através da Faculdade de Ciências, 2014Este trabalho consiste na análise das necessidades nominais de energia útil durante a estação de aquecimento, recorrendo aos métodos descritos na Norma EN ISO 13790:2008 e, adaptados à legislação e exigências climáticas portuguesas.
As metodologias estudadas consistem: 1) método de cálculo quase-estacionário, de base sazonal (método sazonal), descrito na referida norma e, adotado, no Decreto-Lei n.º 118/2013 e 2) no modelo 5R1C, de base horária, descrito na mesma norma e denominado na atual legislação por cálculo dinâmico simplificado. Recorreu-se ao software Matlab, de modo a calcular simultaneamente as necessidades nominais de energia nas respetivas bases temporais. Foram também considerados dois edifícios com utilização residencial, com tipologia unifamiliar e multifamiliar, respetivamente.
Foram testadas metodologias alternativas e alterações pontuais aos métodos propostos, entre elas, o cálculo das necessidades de energia com recurso ao método quase-estacionário numa base mensal (método mensal), e consideração dos ganhos térmicos através da envolvente opaca durante a estação de aquecimento, para uma comparação mais correta entre os resultados das metodologias analisadas.
Este estudo demonstrou que o método sazonal traduz uma aproximação razoável ao método horário, apesar das múltiplas aproximações que este considera. Verificou-se que os resultados do método sazonal são superiores aos do método horário, o que se quantifica numa sobre-estimativa que pode atingir 40%. Aferiu-se que as diferenças entre os métodos sazonal e horário se deveram à forma como são fisicamente definidos os elementos que constituem a envolvente do espaço aquecido. No segundo caso, os elementos com elevada inércia térmica, quando fracamente isolados, possuem uma temperatura significativamente inferior à temperatura de referência imposta (18ºC) para a temperatura do ar. O cálculo das necessidades de energia com recurso à temperatura operativa reduz significativamente as divergências encontradas.The aim of this thesis consists in the analysis of the energy needs for heating, during the heating season, using the methods presented in Norm ISO 13790:2008 and properly adapted to the Portuguese legislation and its climatic requirements. The studied methodologies consist: 1) quasi-steady state method, with a seasonal basis (seasonal method), described in the referred norm and, adopted, to the Portuguese Decree-Law n.º 118/2013 and 2) model 5R1C, hourly time step, described in the same norm and named in the current Portuguese legislation by simplified dynamic calculation. The Matlab software was used in order to calculate simultaneously the energy needs for heating in the respective time steps. It was also considered two buildings with residential use, specifically with single-family and multifamily typologies.
Alternative methodologies and specific changes to the proposed methods were studied, among them the calculation of the heating energy needs using the quasi-steady state method on a monthly basis (monthly method) and the consideration of the heat gains through the opaque envelope, in order to have a more accurate comparison between the results of the analyzed methodologies.
The results demonstrated that the seasonal method translates a reasonable approximation to the hourly method, despite its the multiple approaches considered. It was observed that the results from the seasonal method are superior to the ones from the hourly method, which quantifies an over-estimation which can reach 40%. It was also possible to understand the differences between the seasonal and hourly methods are due to the way elements which constitute the envelope are physically defined. In the second case, the elements with high thermal inertia, when poorly insulated, have a significantly lower temperature than the imposed reference temperature (18 ºC). The calculation of the energy needs using the operative temperature reduces significantly the discrepancies found
Papel das Associações de Estudantes na dinâmica do desporto universitário
Sabendo que a transição para o ensino superior e a frequência universitária representam
um período desafiante, a forma como o estudante se adapta influencia as suas
experiências e aprendizagens. Ainda que os benefícios associados à prática desportiva
por pessoas de todas as idades sejam hoje perfeitamente evidentes, estudos indicam que
os estudantes universitários são insuficientemente ativos e por isso é fundamental
aprofundar o conhecimento sobre este grupo populacional. As Associações de
Estudantes (AE) são a estrutura organizacional que representa os estudantes em cada
estabelecimento de ensino e têm um papel ativo no acolhimento, integração e interação
dos estudantes com o meio académico.
Os objetivos deste estudo são perceber de que forma as AE’s das faculdades da
Universidade de Lisboa gerem o desporto universitário identificando as semelhanças e
diferenças entre elas, verificar se existe preferência por uma dada modalidade por parte
da AE e a razão para isso acontecer.
Fazem parte da amostra treze AE’s das faculdades da Universidade de Lisboa. O
instrumento utilizado para recolha dos dados foi uma entrevista semi-estruturada,
realizada de forma direta e registada através de notas e de audio. O local foi na AE da
respetiva faculdade.
Os resultados obtidos sugerem que os pontos comuns entre as AE’s se resumem à forma
como organizam e desenvolvem as atividades relacionadas com o desporto. Verificou-se
também que há diferenças na importância que é dada a cada modalidade, sendo que há
modalidades que têm melhores condições por já terem obtido melhores resultados.
Melhores condições podem ainda ser desenvolvidas por todas as entidades envolvidas
no desporto universitário.Knowing that the transition to higher education and university attendance is a challenging
period, how the student adapts influences his experiences and learning. Although the
benefits associated with sports practiced by people of all ages are now perfectly evident,
studies indicate that university students are insufficiently active and therefore it is
essential to deepen the knowledge about this population group. Student Associations (SA)
are the organizational structure that represents the students in each educational institution
and play an active role in the welcoming, integration and interaction of students with the
academic environment.
The objectives of this study are understanding how the SA's of the faculties of the
University of Lisbon manage the university sports and identifying the similarities and
differences between them, verifying if there is a preference for a given sport by the SA and
the reason for that to happen.
Thirteen SA's of the faculties of the University of Lisbon are part of the sample. The
instrument used for data collection was a semi-structured interview, performed directly
and recorded through notes and audio. The place was the SA of the respective college.
The results obtained suggest that the common points between the SA’s boil down to the
way they organize and develop sports related activities.
It was also verified that there are differences in the importance given to each sport, as
there are modalities that have better conditions because they have already obtained
better results.
Better conditions can still be developed by all the entities involved in university sports
Chronic stress disrupts neural coherence between cortico-limbic structures
The authors would like to thank Rui Gomes for the help in the application of electrophysio- logical techniques and Luís Martins and Miguel Carneiro for the histological preparations.Chronic stress impairs cognitive function, namely on tasks that rely on the integrity of cortico-limbic networks. To unravel the functional impact of progressive stress in cortico-limbic networks we measured neural activity and spectral coherences between the ventral hippocampus (vHIP) and the medial prefrontal cortex (mPFC) in rats subjected to short term stress (STS) and chronic unpredictable stress (CUS). CUS exposure consistently disrupted the spectral coherence between both areas for a wide range of frequencies, whereas STS exposure failed to trigger such effect. The chronic stress-induced coherence decrease correlated inversely with the vHIP power spectrum, but not with the mPFC power spectrum, which supports the view that hippocampal dysfunction is the primary event after stress exposure. Importantly, we additionally show that the variations in vHIP-to-mPFC coherence and power spectrum in the vHIP correlated with stress-induced behavioral deficits in a spatial reference memory task. Altogether, these findings result in an innovative readout to measure, and follow, the functional events that underlie the stress-induced reference memory impairments.The authors work was supported by FEDER funds through Operational program for competivity factors—COMPETE and by national funds through FCT—Foundation for Science and Technology (FCT) fellowships (João Filipe Oliveira by SFRH/BPD/66151/2009; Luís Ricardo Jacinto by SFRH/BD/40459/2007), a Marie Curie Fellowship (João Filipe Oliveira by PIEF-GA-2010-273936) and Grants from BIAL Foundation (138/2008 to João José Cerqueira and 61/2010 to João Filipe Oliveira and Vanessa Morais Sardinha) and FCT (João Filipe Oliveira, Ana Lima, and Ana Filipa Oliveira by PTDC/SAU- NSC/118194/2010; Nuno Sérgio Dias, Luís Ricardo Jacinto, João José Cerqueira, and Nuno Sousa by FCT/PTDC/SAU- ENB/118383/2010; Nuno Sérgio Dias, Daniela Silva Ferreira, Joana Santos Reis, João José Cerqueira, and Nuno Sousa by FCOMP-01-0124-FEDER-022674)
Age effects on EEG correlates of the Wisconsin card sorting test
Body and brain undergo several changes with aging. One of the domains in which these changes are more remarkable relates with cognitive performance. In the present work, electroencephalogram (EEG) markers (power spectral density and spectral coherence) of age-related cognitive decline were sought whilst the subjects performed the Wisconsin Card Sorting Test (WCST). Considering the expected age-related cognitive deficits, WCST was applied to young, mid-age and elderly participants, and the theta and alpha frequency bands were analyzed. From the results herein presented, higher theta and alpha power were found to be associated with a good performance in the WCST of younger subjects. Additionally, higher theta and alpha coherence were also associated with good performance and were shown to decline with age and a decrease in alpha peak frequency seems to be associated with aging. Additionally, inter-hemispheric long-range coherences and parietal theta power were identified as age-independent EEG correlates of cognitive performance. In summary, these data reveals age-dependent as well as age-independent EEG correlates of cognitive performance that contribute to the understanding of brain aging and related cognitive deficits.The work was partially funded by the European Commission (FP7): “SwitchBox” (Contract HEALTH‐F2‐2010‐259772) and co‐financed by the Portuguese North Regional Operational Program (ON.2 – O Novo Norte) under the National Strategic Reference Framework (QREN), through the European Regional Development Fund (FEDER). This work was also co‐sponsored by FCT – Foundation for Science and Technology and Compete Program with the project reference FCOMP‐01‐0124‐FEDER‐021145 (PTDC/SAU‐ENB/118383/2010) and Agência De Inovação “DoIT ‐ Desenvolvimento e Operacionalização da Investigação de Translação” (project no. 13853, PPS4‐MyHealth), funded by Fundo Europeu de Desenvolvimento Regional (FEDER) through the Programa Operacional Factores de Competitividade (POFC)
Developing an Agent-Based Model for Haplodrassus rufipes (Araneae: Gnaphosidae), a Generalist Predator Species of Olive Tree Pests: Conceptual Model Outline
Olive growing has been facing major sustainability challenges due to intensification,
resulting in an increased use of pesticides and fertilizers and, consequently, in the depletion of
natural resources and loss of biodiversity and landscape values. This has created an urgent need to
develop models for managing complex agroecosystems that integrate factors affecting food quality,
sustainability and biodiversity, providing a supporting technique to understand the consequences
of agricultural management for ecosystem services. We are developing an advanced agent-based
simulation (ABS) applied to olive groves to model the effects of farming practices on the abundance
of olive pest predators. ABS is a modeling technique where agents represent animals (predator
arthropods, in our case) acting in their environment. Our model is based on an ABS system developed
by Aarhus University, the ALMaSS, which comprises highly detailed farm management and spatial
structures to construct dynamic landscapes where agents operate. In this work, we present the
conceptual model for one of the selected species, Haplodrassus rufipes (Araneae: Gnaphosidae.info:eu-repo/semantics/publishedVersio
Pollicipes International Conference
Pollicipes International Conference
www.pollicipes.uevora.p
Evaluating SARS-CoV-2 Seroconversion Following Relieve of Confinement Measures
Funding: This work was supported by FCT grants (PTDC/MECREU/29520/2017 to HS and CHRC UIDB/4923/2020, UIPD/4923/2020). JG, MJJ, and DAS are supported by FCT through /BD/128343/2017, PTDC/EGE-OGE/32573/2017, and PD/BD/137409/2018, respectively. The anti-SARSCoV-2 ELISA assay was developed within the context of Serology4COVID consortium, in which IBET (Instituto de Biologia Experimental e Tecnológica) produced and purified the Spike protein. This initiative was supported by Calouste Gulbenkian Foundation’s Emergency Fund for COVID-19, Sociedade Francisco Manuel dos Santos and Oeiras Municipality.Seroprevalence studies are crucial both for estimating the prevalence of SARS-CoV-2 exposure and to provide a measure for the efficiency of the confinement measures. Portuguese universities were closed on March 16th 2020, when Portugal only registered 62 SARS-CoV-2 infection cases per million. We have validated a SARS-CoV-2 ELISA assay to a stabilized full-length spike protein using 216 pre-pandemic and 19 molecularly diagnosed SARS-CoV-2 positive individual's samples. At NOVA University of Lisbon, presential work was partially resumed on May 25th with staggered schedules. From June 15th to 30th, 3–4 weeks after the easing of confinement measures, we screened 1,636 collaborators of NOVA university of Lisbon for the presence of SARS-CoV-2 spike specific IgA and IgG antibodies. We found that spike-specific IgG in 50 of 1,636 participants (3.0%), none of which had anti-spike IgA antibodies. As participants self-reported as asymptomatic or paucisymptomatic, our study also provides a measurement of the prevalence of asymptomatic/paucisymptomatic SARS-CoV-2 infections. Our study suggests that essential workers have a 2-fold increase in viral exposure, when compared to non-essential workers that observed confinement. Additional serological surveys in different population subgroups will paint a broader picture of the effect of the confinement measures in the broader community.publishersversionpublishe
Algae as food in Europe: an overview of species diversity and their application
ABSTRACT: Algae have been consumed for millennia in several parts of the world as food, food supplements, and additives, due to their unique organoleptic properties and nutritional and health benefits. Algae are sustainable sources of proteins, minerals, and fiber, with well-balanced essential amino acids, pigments, and fatty acids, among other relevant metabolites for human nutrition. This review covers the historical consumption of algae in Europe, developments in the current European market, challenges when introducing new species to the market, bottlenecks in production technology, consumer acceptance, and legislation. The current algae species that are consumed and commercialized in Europe were investigated, according to their status under the European Union (EU) Novel Food legislation, along with the market perspectives in terms of the current research and development initiatives, while evaluating the interest and potential in the European market. The regular consumption of more than 150 algae species was identified, of which only 20% are approved under the EU Novel Food legislation, which demonstrates that the current legislation is not broad enough and requires an urgent update. Finally, the potential of the European algae market growth was indicated by the analysis of the trends in research, technological advances, and market initiatives to promote algae commercialization and consumption.info:eu-repo/semantics/publishedVersio
Apolipoprotein E and undercaboxylated osteocalcin are associated with bone fragility but not with bone mineral density in osteoarthritis patients
Building a system of computational models to simulate natural pest control
A limitação natural de pragas é um serviço de ecossistema que deve ser promovido nos
sistemas agrícolas, já que pode ser usada como alternativa, ou complementarmente, à aplicação
de pesticidas. Consiste no consumo das pragas pelos seus inimigos naturais e pode ser
promovida através do estabelecimento de componentes paisagísticas que forneçam, a estes
inimigos das pragas, alimento alternativo e refúgio, para além da aplicação de práticas agrícolas
sustentáveis. No entanto, o delineamento de uma estratégia eficaz de limitação natural de
pragas está dependente da caracterização detalhada dos comportamentos dos animais que
fazem parte dessa cadeia trófica, nomeadamente, das pragas e dos seus predadores, o que pode
ser feito através de simulações computacionais. Neste contexto, e no âmbito do projeto
OLIVESIM, estamos a construir um sistema de modelos para simular a biologia e o
comportamento de duas espécies de artrópodes (1) a mosca-da-azeitona, Bactrocera oleae
(Rossi), praga chave da oliveira, e (2) a aranha de solo, Haplodrassus rufipes (Lucas), um dos
potenciais predadores da praga, e as suas interações com a paisagem selecionada para realizar
este estudo, localizada na região de Trás-os-Montes (Mirandela, Portugal) e caracterizada
fundamentalmente por olival tradicional. Para isso, está a ser utilizado o sistema ALMaSS
(Animal, Landscape and Man Simulation System), que recebe inputs diários de variáveis
climáticas e também de ações de gestão agrícola, e que é calibrado com dados sobre abundância
quantitativa e qualitativa de animais. Neste simpósio focamo-nos nestes dois modelos,
mostrando também o estado atual deste trabalho.Natural pest control is an ecosystem service that should be promoted in agricultural
systems, as it can be used as an alternative or complementary to pesticide application. It consists
in increasing the populations of natural pest enemies by establishing landscape components
that provide them with alternative food and refuge, and by applying sustainable agricultural
practices. However, the design of an effective strategy for natural pest control depends on the
detailed characterization of the behaviour of animals that are part of this trophic chain, namely
pests and their predators, which can be done through computational simulations. In this
context, and in the scope of project OLIVESIM, we are building a system of models to simulate
the biology and behaviours of two species (1) the olive fly, Bactrocera oleae (Rossi), key pest of
the olive tree, and (2) a ground spider, Haplodrassus rufipes (Lucas), one of the potential
predators of the pest, and their interactions with the landscape selected to carry out this study,
located in the region of Trás-os-Montes (Mirandela, Portugal) and characterized primarily by
traditional olive groves. For this, the ALMaSS (Animal, Landscape and Man Simulation System)
system is being used, which receives daily inputs of climatic variables and agricultural
management actions, and which is calibrated with data on quantitative and qualitative
abundance of animals. In this symposium, we focus on the models for these two animal species,
showing the current state of this work.info:eu-repo/semantics/publishedVersio