Otimização e análise mecânica de pastas geopoliméricas para uso em poços sujeitos à injeção cíclica de vapor

Oil wells subjected to cyclic steam injection present important challenges for the development of well cementing systems, mainly due to tensile stresses caused by thermal gradients during its useful life. Cement sheath failures in wells using conventional high compressive strength systems lead to the use of cement systems that are more flexible and/or ductile, with emphasis on Portland cement systems with latex addition. Recent research efforts have presented geopolymeric systems as alternatives. These cementing systems are based on alkaline activation of amorphous aluminosilicates such as metakaolin or fly ash and display advantageous properties such as high compressive strength, fast setting and thermal stability. Basic geopolymeric formulations can be found in the literature, which meet basic oil industry specifications such as rheology, compressive strength and thickening time. In this work, new geopolymeric formulations were developed, based on metakaolin, potassium silicate, potassium hydroxide, silica fume and mineral fiber, using the state of the art in chemical composition, mixture modeling and additivation to optimize the most relevant properties for oil well cementing. Starting from molar ratios considered ideal in the literature (SiO2/Al2O3 = 3.8 e K2O/Al2O3 = 1.0), a study of dry mixtures was performed,based on the compressive packing model, resulting in an optimal volume of 6% for the added solid material. This material (silica fume and mineral fiber) works both as an additional silica source (in the case of silica fume) and as mechanical reinforcement, especially in the case of mineral fiber, which incremented the tensile strength. The first triaxial mechanical study of this class of materials was performed. For comparison, a mechanical study of conventional latex-based cementing systems was also carried out. Regardless of differences in the failure mode (brittle for geopolymers, ductile for latex-based systems), the superior uniaxial compressive strength (37 MPa for the geopolymeric slurry P5 versus 18 MPa for the conventional slurry P2), similar triaxial behavior (friction angle 21° for P5 and P2) and lower stifness (in the elastic region 5.1 GPa for P5 versus 6.8 GPa for P2) of the geopolymeric systems allowed them to withstand a similar amount of mechanical energy (155 kJ/m3 for P5 versus 208 kJ/m3 for P2), noting that geopolymers work in the elastic regime, without the microcracking present in the case of latex-based systems. Therefore, the geopolymers studied on this work must be designed for application in the elastic region to avoid brittle failure. Finally, the tensile strength of geopolymers is originally poor (1.3 MPa for the geopolymeric slurry P3) due to its brittle structure. However, after additivation with mineral fiber, the tensile strength became equivalent to that of latex-based systems (2.3 MPa for P5 and 2.1 MPa for P2). The technical viability of conventional and proposed formulations was evaluated for the whole well life, including stresses due to cyclic steam injection. This analysis was performed using finite element-based simulation software. It was verified that conventional slurries are viable up to 204ºF (400ºC) and geopolymeric slurries are viable above 500ºF (260ºC)

Memórias de São Miguel de Machede (I)

Na década de sessenta, em São Miguel de Machede, funcionavam quatro escolas primárias. Nos últimos anos do século XX, apenas restava uma escola em funcionamento, No ano em que este livro é publicado, entraram apenas duas crianças para o primeiro ano de escolaridades. Simultaneamente a esta triste demografia escolar, verifica-se igual fenómeno na população, em geral. Na realidade, esta pequena vila e freguesia do concelho de Évora, é cada vez mais, um espaço do passado e, cada vez menos, de futuro. Daí que a memória seja um aspeto cada vez mais presente no quotidiano de todos os micaelenses. A memória dos momentos que se viveram e das pessoas que se conheceram. Recordar o passado poderá não ser, simplesmente, uma questão de saudade ou de nostalgia. A memória de uma comunidade, como são Miguel de Machede, poderá assumir-se como alicerce da construção de uma identidade e de um futuro. Recordar, para os adultos, ou conhecer, no caso dos jovens, momentos significativos e simbólicos da história da comunidade a que se pertencem, poderá construir uma estratégia adequada para a partilha de conhecimento e para o reforço da comunidade entre as diferentes gerações.

Articulação saúde-escola: a intervenção em contexto comunitário

As perturbações psiquiátricas e os problemas de saúde mental infantojuvenil têm vindo a merecer especial atenção por parte da comunidade científica, não só pelo facto de se estimar que 10 a 20% das crianças apresentem um ou mais problemas de saúde mental, não só por estes valores terem tendência a aumentar, mas também pelo impacto humano e financeiro que acarretam para a sociedade. Em Portugal, o Plano Nacional da Saúde Mental 2007-2016 é categórico ao afirmar a necessidade de promover a saúde mental infantojuvenil junto da população e ao salientar a importância do envolvimento e articulação com outras estruturas comunitárias ligadas à saúde, educação e direito de menores. Este trabalho vai de encontro a estas linhas de orientação, na medida em que procura identificar, desenvolver e implementar diversos aspetos inerentes à vertente comunitária da saúde mental infantojuvenil. Numa primeira fase é realizado um levantamento das reais necessidades da população infantojuvenil do concelho de Odemira e é definida uma rede de articulação entre os serviços de saúde, escolas e outras entidades locais com competência nesta área. De forma a melhorar a prestação dos cuidados e a garantir respostas adequadas às necessidades identificadas, também se procurou o individual desenvolvimento de competências especializadas na área da saúde mental infantojuvenil. Por último, atendendo à importância da implementação atempada de medidas preventivas de determinados fenómenos psicopatológicos, procurou-se treinar e desenvolver a capacidade de sensibilização e reforço de competências de uma bolsa populacional específica: a comunidade escolar. De um modo geral, os resultados obtidos demonstram aplicabilidade na prática clínica dos cuidados, contribuindo para a melhoria dos mesmos. Algumas das estratégias utilizadas constituem-se como ponto de partida para projetos futuros, podendo ser replicadas e adequadas a outros contextos de intervenção; ABSTRACT: LINK HEALTH-SCHOOL: the intervention in the community context Psychiatric disorders and problems of youth mental health have been given special attention by the scientific community, not only because it is estimated that 10-20% of children present one or more mental health problems, not only because these values have tendency to increase, but also the human and financial impact to society. In Portugal, the Mental Health National Plan 2007-2016 is emphatic in affirming the need to promote the mental youth health within the population and to emphasize the importance of the involvement and coordination with other community entities related to health, education and minors rights. This paper follows these guidelines, it tries to identify, develop and implement various aspects related to the Community part of youth health. In the first phase is carried out a survey of the real needs of youth population of the Odemira County and defined a network between health services, schools and other local organizations with expertise in this area. In order to improve the delivery of health care and ensure appropriate responses to the identified needs, also sought the individual development of expertise in the area of youth mental health. Finally, given the value of timely implementation of preventive measures of certain psychopathological phenomena, it sought to train and develop the awareness and skills improvement of a specific population: the school community. In general, the results prove the applicability of the procedures in clinical practice, contributing to a practice improvement. Some of the strategies used are the Foundation for future projects, they can be replicated and adapted to other contexts of intervention.

Avaliação de concretos reforçados por confinamento com manta de fibra de vidro estrutural e pré-impreganada

Due to the occurrence of diseases in the use of structural reinforcements in composites, with presentation of concrete blanket detachment, has been identified the need to evaluate the performance of concrete reinforced with glass fiber. This study aims to evaluate these concretes by means of testing methodologies, using concrete with low resistance with structural reinforcement for confinement by preimpregnated glass fiber and traditional fiberglass blanket. The first stage of work was the development of methodologies for analysis, opting for four types, such as the acoustic survey, strength to compressive, the pull-off and ultrasound. Next, tests were carried out using the four selected methodologies in 30 of proof-of-specimens by 5x10 cm, 15 were reinforced with the traditional fiberglass blanket with 5specimens exposed to test a marine environment of marine coastline of Natal-RN and 15 were reinforced with a pre-impregnated glass fiber blanket, as well as 5specimens exposed to a test environment of the marine coastline of Natal-RN. After conducting the acoustic survey, it has been verified a lack of delaminating and air bubbles in the samples, confirming the absence of gross shortcomings in the implementation of the ribs both the traditional fiberglass blanket and in the preimpregnated fiber glass blanket. After carrying out methods of pull-off and compressive strengthening test it was observed that the reinforced proof-bodies with pre-impregnated glass blanket showed maximum stresses higher than the traditional fiberglass blanket; consequently a greater grip with the formation of a smaller area of . fracture, unlike traditional glass mat, which showed lower maximum stresses, with a greater area of fracture. It was also found that the traditional fiberglass blanket presented detachment of blanket-concrete interface, unlike the pre-impregnated fiberglass blanket, which showed a better grip on the blanket-concrete interface. In the trial of ultrasound there was no presence of cracks in the blanket-concrete interface, yielding to both blankets good compactness of the concrete. At the end of this work, they were developed and proposed two methods of testing for evaluation of reinforced concrete structures with composites, for standardization, the acoustic survey and pull-off

A relevância geoestratégica da Turquia para a segurança energética da União Europeia : o caso do gás natural

Nos próximos anos a União Europeia terá crescentes necessidades de importação de gás natural, existindo uma preocupação com os riscos inerentes à dependência face ao gás russo, especialmente nos países do centro e leste europeu. Esses riscos foram evidenciados pelas crises e conflitos que opuseram a Rússia à Ucrânia e à Geórgia e mostraram à União Europeia a necessidade de encontrar alternativas que diminuíssem a sua vulnerabilidade. As alternativas possíveis passam por incrementar a produção de shale gas, aumentar a importação do Gás Natural Liquefeito e diversificar os fornecedores. A União Europeia tem apostado num corredor meridional de gás, cujo objetivo é obter fornecimento do Médio Oriente, do Cáucaso do Sul e da Ásia Central. Esta opção europeia faz ressurgir a importância geoestratégica da Turquia. No artigo propomo-nos discutir a estratégia europeia para diminuir a sua vulnerabilidade energética no abastecimento de gás natural e as vantagens que poderão resultar do reforço da relação com a Turquia nesta área.

Cooperação Internacional

A Força de Gendarmerie Europeia ergueu-se na esfera dos países da União Europeia com forças de polícia de estatuto militar, tipo gendarmerie, com o propósito de proporcionar uma ferramenta de cooperação internacional que permitira aumentar a capacidade de gestão de crises e contribuir para o desenvolvimento da identidade europeia de segurança e defesa, bem como para o reforço da Política Comum de Segurança e Defesa. Depois de dez anos passados após a plena capacidade operacional, interessa avaliar se a Organização constitui verdadeiramente um instrumento eficaz, eficiente e proveitoso para os seus Estados-Membros e para as principais organizações internacionais, bem como ponderar o seu impacto na ação externa da União Europeia. Com este objetivo, desenvolveu-se uma investigação qualitativa recorrendo ao raciocínio hipotético-dedutivo. Esquadrinharam-se questões de natureza descritiva e interpretativa, conferindo uma importância especial aos contributos facilitados pelos entrevistados, dotados de destacada relevância profissional na esfera da cooperação policial internacional. Constata-se no estudo que a Força de Gendarmerie Europeia constitui um instrumento útil para a cooperação internacional, oferecendo capacidades operacionais bem-sucedidas assentes no treino permanente, na interoperabilidade com os atores participantes e na capacidade de resposta rápida a situações de crise. Abstract: The European Gendarmerie Force stood up in the background of European Union countries with military status police forces, gendarmerie type, in order to provide a tool for international cooperation increasing crisis management capacities and contributing to the development of the European security and defence identity, in addition to strengthening the Common European Security and Defence Policy. Ten years after achieving full operational capability, it is intended to assess if the Organization actually performs an effective, efficient and profitable instrument for its Member States and the main international organizations, as well as considering its impact on external action of the European Union. With that aim, a qualitative research was developed using the hypothetical-deductive reasoning. Descriptive and interpretative issues were scoured, giving special importance to contributions provided by respondents with outstanding professional background in international police cooperation sphere. The study reveals that the European Gendarmerie Force is a useful tool for international cooperation, providing successful operational capabilities settled in permanent training, interoperability with the participating actors and in a rapid response capability to crisis situations.

Avaliação dos valores séricos de troponina cardíaca I (cTnI) e capacidade antioxidante total (TAC) em felídeos com doença renal crónica e seu valor de prognóstico : estudo preliminar

Dissertação de Mestrado Integrado em Medicina Veterinária

Política europeia de vizinhança : onde se joga o futuro da Europa

A Política Europeia de Vizinhança constitui uma importante plataforma de relacionamento externo e de afirmação da UE. A natureza multifacetada desta política de relacionamento externo sob a forma de acordos bilaterais com parceiros da periferia europeia de natureza política, económica, de circulação, de apoio nas reformas das administrações locais até formas mais ou menos aprofundadas de associação política, determinam a tipologia dos acordos firmados com parceiros externos e são afetados pela continuidade ou descontinuidade geográfica, pela especificidade sociocultural, pelas clivagens religiosas e pela diversidade identitária, pela presença de vários atores regionais com aspirações regionais e pela coexistência de várias iniciativas e programas regionais europeus. O artigo reflete sobre o impacto e eficácia do princípio de “Mais por Mais” decorrente da revisão e reforço da Política de Vizinhança em 2010 com base na condicionalidade da disseminação da democracia e o aprofundamento das parcerias entre a UE e Estados limítrofes. Conclui com uma reflexão sobre o futuro das parcerias de cooperação hoje afetadas pela crise económica e de funcionalidade da UE, futuro da designada Primavera Árabe, pela eclosão da crise na Ucrânia e da guerra na Síria.

O Conselho Europeu de Dezembro de 2013

O presente artigo debruça-se sobre a capacidade da União Europeia atuar em termos de Política Comum de Segurança e Defesa como um ator unitário, analisando para o efeito os constrangimentos que impedem o desenvolvimento do seu potencial. O Conselho Europeu de dezembro de 2013, largamente dedicado à PCSD e ao reforço das capacidades europeias, avaliou e deu um novo rumo à política europeia, na sequência das propostas feitas pela Alta Representante, um ano antes. O artigo desenvolve a posição portuguesa no período que precedeu o Conselho Europeu de dezembro e a posição nacional sobre a revisão da Estratégia Europeia de Segurança.

Estudo da vegetação arbórea e arbustiva adequada a projetos de engenharia natural em Portugal

Doutoramento em Engenharia Florestal e dos Recursos Naturais - Instituto Superior de Agronomia - UL

Estudo comparativo de pás para aerogeradores de grande porte fabricadas em materiais compósitos reforçadas com fibra de carbono ou fibra de vidro

The research and development of wind turbine blades are essential to keep pace with worldwide growth in the renewable energy sector. Although currently blades are typically produced using glass fiber reinforced composite materials, the tendency for larger size blades, particularly for offshore applications, has increased the interest on carbon fiber reinforced composites because of the potential for increased stiffness and weight reduction. In this study a model of blade designed for large generators (5 MW) was studied on a small scale. A numerical simulation was performed to determine the aerodynamic loading using a Computational Fluid Dynamics (CFD) software. Two blades were then designed and manufactured using epoxy matrix composites: one reinforced with glass fibers and the other with carbon fibers. For the structural calculations, maximum stress failure criterion was adopted. The blades were manufactured by Vacuum Assisted Resin Transfer Molding (VARTM), typical for this type of component. A weight comparison of the two blades was performed and the weight of the carbon fiber blade was approximately 45% of the weight of the fiberglass reinforced blade. Static bending tests were carried out on the blades for various percentages of the design load and deflections measurements were compared with the values obtained from finite element simulations. A good agreement was observed between the measured and calculated deflections. In summary, the results of this study confirm that the low density combined with high mechanical properties of carbon fibers are particularly attractive for the production of large size wind turbine blades

Compósitos poliméricos a base de fibras de licuri: efeitos da hibridização e do envelhecimento ambiental acelerado

The gradual replacement of conventional materials by the ones called composite materials is becoming a concern about the response of these composites against adverse environmental conditions, such as ultraviolet radiation, high temperature and moist. Also the search for new composite using natural fibers or a blend of it with synthetic fibers as reinforcement has been studied. In this sense, this research begins with a thorough study of microstructural characterization of licuri fiber, as a proposal of alternative reinforcement to polymeric composites. Thus, a study about the development of two composite laminates was done. The first one, involving only the fiber of licuri and the second comprising a hybrid composite based of fiber glass E and the fiber of licuri, in order to know the performance of the fiber when of fiber across the hybridization process. The laminates were made in the form of plates using the tereftálica ortho-polyester resin as matrix. The composite laminate made only by licuri fiber had two reinforcing fabric layers of unidirectional licuri and the hybrid composite had two reinforcing layers of unidirectional licuri fabric and three layers of fiber short glass-E mat. Finally, both laminates was exposed to aging acceleration in order to study the influence of environmental degradation involving the mechanical properties and fracture characteristics thereof. Regarding the mechanical properties of composites, these were determined through uniaxial tensile tests, uniaxial compression and three bending points for both laminates in original state, and uniaxial tensile tests and three bending points after accelerated aging. As regards the study of structural degradation due to aging of the laminates, it was carried out based on microscopic analysis and microstructure, as well as measuring weight loss. The characteristics of the fracture was performed by macroscopic and microscopic (optical and SEM) analysis. In general, the laminated composites based on fiber licuri showed some advantages in their responses to environmental aging. These advantages are observed in the behavior related to stiffness as well as the microstructural degradation and photo-oxidation processes. However, the structural integrity of this laminate was more affected in case the action of uniaxial tensile loads, where it was noted a lower rate of withholding his last resistance property

Efeito da adição de grafite expandido por microondas nas propriedades térmicas, elétricas e mecânicas de nanocompósitos de matriz epóxi

Epoxy based nanocomposites with 1 wt % and 3 wt % of nanographite were processed by high shear mixing. The nanographite was obtained by chemical (acid intercalation), thermal (microwave expansion) and mechanical (ultrasonic exfoliation) treatments. The mechanical, electrical and thermal behavior of the nanocomposites was determined and evaluated as a function of the percentage of reinforcement. According to the experimental results, the electrical conductivity of epoxy was not altered by the addition of nanographite in the contents evaluated. However, based on the mechanical tests, nanocomposites with addition of 1 wt.% and 3 wt.% of nanographite showed increase in tensile strength of 16,62 % and 3,20 %, respectively, compared to the neat polymer. The smaller increase in mechanical strength of the nanocomposite with 3 wt.% of nanographite was related to the formation of agglomerates. The addition of 1 wt.% and 3 wt.% of nanographite also resulted in a decrease of 6,25 % and 17,60 %, respectively, in the relative density of the material. Thus, the specific strength of the nanocomposites was approximately 33,33 % greater when compared to the neat polymer. The addition of 1 wt.% and 3 wt.% of nanographite in the material increased the mean values of thermal conductivity in 28,33 % and 132,62 %, respectively, combined with a reduction of 26,11 % and 49,80 % in volumetric thermal capacity, respectively. In summary, it has been determined that an addition of nanographite of the order of 1 wt.% and 3 wt.% produced notable elevations in specific strength and thermal conductivity of epoxy

Estudo sobre as potencialidades de compósitos à base de gesso e fibras de coco seco para aplicação na construção civil

The use of gypsum, one of the oldest building materials for the construction industry in the country has been experiencing a significant and steady growth, due to its low cost and some of its properties that confer comparative advantage over other binder materials. Its use comprises various applications including the coating of walls and the production of internal seals and linings. Moreover, the fibers are being increasingly incorporated into arrays fragile in an attempt to improve the properties of the composite by reducing the number of cracks, the opening of the same and its propagation velocity. Other properties, depending on the function of the component material or construction, among these thermal and acoustic performances, are of great importance in the context of buildings and could be improved, that is, having better performance with this embodiment. Conduct a comparative study of physico-mechanical, thermal and acoustic composite gypsum incorporating dry coconut fiber, in the form of blanket, constituted the main objective of this work. Improving the thermal and acoustic performances of precast gypsum, used for lining and internal vertical fences of buildings, was the purpose of development of these composites. To evaluate the effect of fiber content on the properties of the composites were used to manufacture the composite layer with different thicknesses. The composites were fabricated in the form of plates with dimensions of 500x500x24mm. To facilitate the comparative study of the properties were also made with material gypsum boards only. We then determined the physico-mechanical, thermal and acoustical plaster and composites. The results indicated that the composites were significant gains in relation to thermal performance and also acoustic, in certain frequency range, increasing the thickness of the blanket. Concerning other physical-mechanical properties, the results showed that although the compressive strength was lower than for the composite did not occur after a fracture catastrophic failure. The same trend was observed with regard to resistance to bending, since the composites have not suffered sudden rupture and still continued after the load supporting point of maximum load

Relatório de Estágio

A asma é uma doença crónica das vias respiratórias, normalmente associada a uma hiper- reatividade das vias aéreas e a uma obstrução variável do fluxo de ar. É um problema grave de saúde global e que se encontra associado a vários fatores como o envelhecimento, a pobreza, desemprego e condições de vida insalubres. A adesão ao tratamento é importante para que exista o bom controlo da asma, contribuindo dessa forma para a melhoria na qualidade de vida com redução dos custos associados à doença. A intervenção de uma equipa multidisciplinar, sistematizando conhecimentos em diversas áreas para a prevenção e educação na saúde, promovendo o reforço do poder e da responsabilidade do doente, contribuindo para a melhoria individual e coletiva dentro de um contexto de vida saudável, tem como objetivo incentivar alterações de comportamentos para a melhoria de estilos de vida mais saudáveis. A implementação da consulta de enfermagem surgiu da necessidade em acompanhar doentes com o diagnóstico de asma uma vez que só existe consulta médica. A consulta de enfermagem tem por finalidade reforçar a educação do doente e proporcionar maior segurança e aceitação na adesão e controlo da doença