21 research outputs found

    Modelação computacional do comportamento térmico de uma estufa

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    A necessidade de produção de todo o tipo de plantações em elevadas quantidades e ao longo de todo o ano faz do setor da agricultura um dos principais consumidores energéticos. A otimização deste consumo é essencial para garantir a sustentabilidade do mesmo. A implementação de estufas é uma estratégia que permite garantir as necessidades de produção, assim como possui grande potencial para otimização do processo. Nesta dissertação foram estudadas estas estruturas com recurso à simulação computacional. O primeiro passo foi a construção do modelo computacional, seguido da sua validação através da comparação com dados experimentais já existentes, e por fim uma série de estudos de caso foram realizados para avaliar os efeitos de diferentes parâmetros construtivos e operativos no comportamento térmico da estufa. Os resultados obtidos mostraram que a utilização de envidraçados de várias camadas e a variação da taxa de renovação do ar interior produziram os resultados com maior impacto. Estas técnicas permitem reduzir significativamente o consumo energético destas estruturas, promovendo a sua sustentabilidade.The need for the production of all kinds of crops in high quantities and during the entire year makes the agricultural sector one of the main energy consumers. The optimization of this consumption is essential to guarantee the sustainability of it. The implementation of greenhouses is a strategy that allows assuring the production needs, as well as possess large optimization potential of the process. In this dissertation the structures were studied by the means of computational simulation. The first step was the building of the computational model, followed by its validation through comparison with already-existing experimental data, and lastly a series of case studies were developed as to evaluate the effects of different constructive and operative parameters on the greenhouse's thermal behavior. The results obtained showed that the utilization of multi-layered glazing and variation of inside air exchange rates produced the results with the biggest impact. These techniques allow significant reduction of the energy consumption of these structures, promoting its sustainability

    Integração de plataformas de apoio à aprendizagem com os sistemas de informação académicos da Universidade de Lisboa

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    Tese de mestrado, Engenharia Informática (Arquitectura, Sistemas e Redes de Computadores, Universidade de Lisboa, Faculdade de Ciências, 2014A utilização de diferentes plataformas para a gestão de informação e publicação de conteúdos nas Escolas da Universidade de Lisboa tem vindo a levantar problemas de coerência dos dados e duplicação de informação e esforço. Este trabalho aborda os desafios colocados pela integração da informação entre duas plataformas com objetivos e modelos de desenvolvimento distintos, uma de gestão académica SiGES e a outra de apoio à aprendizagem Moodle. A comunicação entre as plataformas foi assegurada pela tecnologia de serviços web, beneficiando desta forma da existência de mecanismos básicos de suporte a esta tecnologia utilizada em ambas. Além de diagnosticar novos problemas e resolver alguns dos já identificados, este trabalho define um modelo que facilitará a concretização de novas funcionalidades e automatismos para outras necessidades que se venham a colocar no futuro.With the use of different platforms for information management and publishing content in Schools of University of Lisbon there have been raised some issues of data consistency and duplication of information and effort. This paper addresses the challenges posed by the integration of information between two platforms with different objectives and models of development including the academic management platform SiGES and the learning management platform Moodle. The communication between the two platforms was provided by web services technology, thus benefiting from the existence of basic mechanisms supporting this technology on both platforms. In addition to identify and resolve some of the problems already identified, this work defines a model that will facilitate the implementation of new features and automatic procedures for other needs that may be challenged in the future

    Computational Modeling of the Thermal Behavior of a Greenhouse

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    The need for production of all kinds of crops in high quantities and over the entire year makes the agricultural sector one of the major energy consumers. The optimization of this consumption is essential to guarantee its sustainability. The implementation of greenhouses is a strategy that allows assurance of production needs and possesses large optimization potential for the process. This article studies different greenhouse structures by computational simulation using EnergyPlus and DesignBuilder. First, a comparison was performed between the computational results and the measured values from a greenhouse prototype at different operating conditions. Overall, the comparison shows that the computational tool can provide a reasonable prediction of the greenhouse thermal behavior, depending on the differences between the weather data modeled and observed. An outdoor air temperature difference of 16 ◦C can cause a difference of about 10 ◦C between the air temperature predicted and measured inside the greenhouse. Subsequently, a selected set of case studies was developed in order to quantify their influence on the thermal performance of the greenhouse, namely: the greenhouse configuration and orientation; the variation of indoor air renewal; changes to the characteristics of the roof; the effect of the thermal mass of the walls; and location of the greenhouse. The results show that a correct greenhouse orientation, together with a polyethylene double cover with a 13 mm air layer, a granite wall of 40 cm thickness on the north wall, and variable airflow rate, may lead to a reduction of the greenhouse energy consumption by 57%, if the greenhouse is located in Lisbon, or by 43%, if it is located in Ostersund, during the harshest months of the heating season.info:eu-repo/semantics/publishedVersio

    Degradation and Toxicity of Amoxicillin After Electron Beam Irradiation

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    A recent and growing concern in environmental studies is the presence of antibiotics in wastewater, which contributes to antimicrobial resistance building. Amoxicillin, according to the World Health Organization, is one of the most consumed antibiotics worldwide, for being a first line therapy for common infections. Among several drug degradation methodologies, electron beam irradiation (EBI) is presented as an efficient and green treatment. This work presents data on amoxicillin degradation via EBI. Ecotoxicity essays were performed employing Vibrio fischeri, carbon removal efficiency was evaluated by TOC and degradation rate by LC/MS-MS. Chromatographic results indicate a 97.9% drug concentration reduction after 0.75 kGy; TOC results indicate 10% carbon removal at 3.0 kGy; toxicity assays indicate 80% in removal of toxicity at 0.75 kGy and a decrease in efficiency with higher doses. In conclusion, results indicate the 0.75 kGy as most effective for drug removal employing EBI

    PROT-OVT: Plano Regional de Ordenamento do Territorio do Oeste e Vale do Tejo

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    Os princípios, objectivos e orientações consagrados no Programa Nacional da Política de Ordenamento do Território (PNPOT), aprovado pela Lei n.º 58/2007, de 4 de Setembro, são desenvolvidos nos vários planos regionais de ordenamento do território (PROT) que, por sua vez, constituem um quadro de referência estratégico para os planos directores municipais (PDM). No processo de elaboração e revisão articulada destes três pilares fundamentais do sistema de gestão territorial, em que assenta a política de ordenamento do território e do urbanismo, cabe aos PROT uma posição de charneira fundamental. O significado e as potencialidades dos PROT são ainda significativamente ampliados pela articulação com a revisão dos PDM. Face a uma nova geração de PDM, que se pretendem mais estratégicos, os PROT fornecem um quadro de referência estratégica de longo prazo que permite aos municípios estabelecerem as suas opções de desenvolvimento e definirem regras de gestão territorial compatíveis com o modelo consagrado para a região. Os PROT, além de um pilar da política de desenvolvimento territorial, são documentos fundamentais para a definição dos programas de acção das intervenções co-financiadas pelos Fundos Estruturais e de Coesão da União Europeia. Os PROT são instrumentos de desenvolvimento territorial e de natureza estratégica. Em matéria de conteúdo, estabelecem a estrutura regional do sistema urbano, das redes de infra‑estruturas e dos equipamentos de interesse regional e definem os objectivos e princípios quanto à localização das actividades e os grandes investimentos públicos; as suas normas fixam o quadro estratégico, as orientações de carácter genérico e as directrizes para o ordenamento do território regional. O PROT do Oeste e Vale do Tejo (PROT OVT) visa, neste contexto, a espacialização de estratégias de desenvolvimento territorial nos territórios das NUTS III do Oeste, Médio Tejo e Lezíria do Tejo. Por isso, ocupa, entre o nível nacional e o nível municipal, uma posição chave para a definição das estratégias e das opções de desenvolvimento e de ordenamento regional. O PROT OVT é pois um instrumento privilegiado para promover a reflexão estratégica do desenvolvimento do Oeste e do Vale do Tejo e acolher a tomada de decisão quanto às opções de desenvolvimento territorial [...]info:eu-repo/semantics/publishedVersio

    Computational Modeling of the Thermal Behavior of a Greenhouse

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    The need for production of all kinds of crops in high quantities and over the entire year makes the agricultural sector one of the major energy consumers. The optimization of this consumption is essential to guarantee its sustainability. The implementation of greenhouses is a strategy that allows assurance of production needs and possesses large optimization potential for the process. This article studies different greenhouse structures by computational simulation using EnergyPlus and DesignBuilder. First, a comparison was performed between the computational results and the measured values from a greenhouse prototype at different operating conditions. Overall, the comparison shows that the computational tool can provide a reasonable prediction of the greenhouse thermal behavior, depending on the differences between the weather data modeled and observed. An outdoor air temperature difference of 16 °C can cause a difference of about 10 °C between the air temperature predicted and measured inside the greenhouse. Subsequently, a selected set of case studies was developed in order to quantify their influence on the thermal performance of the greenhouse, namely: the greenhouse configuration and orientation; the variation of indoor air renewal; changes to the characteristics of the roof; the effect of the thermal mass of the walls; and location of the greenhouse. The results show that a correct greenhouse orientation, together with a polyethylene double cover with a 13 mm air layer, a granite wall of 40 cm thickness on the north wall, and variable airflow rate, may lead to a reduction of the greenhouse energy consumption by 57%, if the greenhouse is located in Lisbon, or by 43%, if it is located in Ostersund, during the harshest months of the heating season

    Osteoartrose do joelho secundária a ocronose – Caso clínico

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    ResumoA alcaptonúria é uma doença metabólica rara em que a deficiência da enzima ácido homogentísico‐oxidase provoca uma acumulação de ácido homogentísico. A ocronose consiste na deposição excessiva de ácido homogentísico no tecido conjuntivo e apresenta‐se como uma pigmentação acastanhada ou preta. Com o envelhecimento, a acumulação de pigmentos de ácido homogentísico nas articulações provoca osteoartrose. Não existe um tratamento específico para a doença e a abordagem é sintomática. A artroplastia é a solução para casos graves de osteoartrose causada por essa patologia e apresenta resultados comparáveis aos doentes com osteoartrose primária. Os autores apresentam o caso de um doente de 67 anos submetido a várias artroplastias, em virtude da osteoartrose causada por essa rara patologia. A última intervenção cirúrgica foi uma artroplastia total do joelho direito.AbstractAlkaptonuria is a rare metabolic disease in which a deficiency of the enzyme homogentisate dioxygenase causes an accumulation of homogentisic acid. Ochronosis consists of excessive deposition of homogentisic acid in the connective tissue and presents as a chestnut brown or black pigmentation. With aging, the accumulation of pigments from homogentisic acid in the joints causes osteoarthrosis. There is no specific treatment for the disease and the approach is symptomatic. Arthroplasty is the solution for severe cases of osteoarthrosis caused by this pathological condition and presents results comparable to those from patients with primary osteoarthrosis. Here, the case of a 67‐year‐old patient who underwent several arthroplasty procedures because of osteoarthrosis caused by this rare pathological condition is presented. The last surgical intervention consisted of total right knee arthroplasty

    Knee osteoarthrosis secondary to ochronosis -clinical case,

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    Alkaptonuria is a rare metabolic disease in which a deficiency of the enzyme homogentisate dioxygenase causes an accumulation of homogentisic acid. Ochronosis consists of excessive deposition of homogentisic acid in the connective tissue and presents as a chestnut brown or black pigmentation. With aging, the accumulation of pigments from homogentisic acid in the joints causes osteoarthrosis. There is no specific treatment for the disease and the approach is symptomatic. Arthroplasty is the solution for severe cases of osteoarthrosis caused by this pathological condition and presents results comparable to those from patients with primary osteoarthrosis. Here, the case of a 67-year-old patient who underwent several arthroplasty procedures because of osteoarthrosis caused by this rare pathological condition is presented. The last surgical intervention consisted of total right knee arthroplasty
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