264 research outputs found

    Role of shore platforms on coastal cliffs protection in Algarve (South Portugal): first approach

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    The complex interaction between morphogenetic processes acting on rocky coasts and substrate characteristics difficult the assessment of its evolution at different time scales. In opposition to other coastal environments such as beaches, where variations on substrate’s attributes are constrained to a few possibilities, rocky coasts expose substrates having large amount of variables, among them, lithology, mechanical and chemical strength, density and orientation of faults and joints and, rocks’ texture and structure (e.g., Trenhaile, 2003).Portuguese Foundation for Science and Technology-FC

    Observation of Replica Symmetry Breaking in the 1D Anderson Localization Regime in an Erbium-Doped Random Fiber Laser

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    The analogue of the paramagnetic to spin-glass phase transition in disordered magnetic systems, leading to the phenomenon of replica symmetry breaking, has been recently demonstrated in a two-dimensional random laser consisting of an organic-based amorphous solid-state thin film. We report here the first demonstration of replica symmetry breaking in a one-dimensional photonic system consisting of an erbium-doped random fiber laser operating in the continuous-wave regime based on a unique random fiber grating system, which plays the role of the random scatterers and operates in the Anderson localization regime. The clear transition from a photonic paramagnetic to a photonic spin glass phase, characterized by the probability distribution function of the Parisi overlap, was verified and characterized. In this unique system, the radiation field interacts only with the gain medium, and the fiber grating, which provides the disordered feedback mechanism, does not interfere with the pump

    Characterization of Acrocarpus fraxinifolius wood submitted to heat treatment

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    Aiming to provide greater visibility for the wood species Acrocarpus fraxinifolius, the present study sought to analyze the influence of heat treatment on an industrial scale applied to wood species, also popularly known as Indian cedar. The heat treatment was carried out in an autoclave, with temperature and pressure control, and with saturated steam injection, for temperatures 155 ÂșC, 165 ÂșC, 175 ÂșC, and 185 ÂșC. Physical, chemical, and mechanical tests were carried out for the analyzed wood. The content of holocellulose and total lignin decreased, while the content of extractives showed a substantial increase. The density increased after the heat treatment, however the treated wood showed cracks, and these cracks influenced the significant loss of the values of the mechanical properties of compression, tension, and flexion. The shear showed strength gain for the temperature of 155 ÂșC, and the wood treated at 165 ÂșC was equivalent to untreated wood. The woods submitted to temperatures of 175 ÂșC and 185 ÂșC presented strength losses. The heat treatment in question contributes to increase the visibility, use and market value of wood

    Environmental Assessment for Ocean Energy Schemes: Useful Tools and Case Studies

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    This work concerns a review of the state of the art of current and practical experience on environmental assessment (including monitoring) in order to set the path to be followed for future ocean energy schemes. It includes a revision of the work done so far in some test sites and deployment sites and discusses the use of several tools considering project phases (installation, deployment and decommissioning) and environmental impact assessment steps (screening, scoping, baseline studies for reference condition characterization, impact identification and evaluation, mitigation measures and monitoring). Within the list of such tools the applicability of checklists, matrices, mathematical modelling, Geographic Information Systems are considered as well as other shared and integrative methods: Environmental Risk Assessment and Life Cycle Analysis

    AnĂĄlise da AderĂȘncia das PrĂĄticas Recomendadas pelos MĂ©todos Ágeis: XP, Scrum e TDD com a Utilização de Ferramentas CASE

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    Este artigo especifica uma métrica para avaliar o nível de aderência das funcionalidades oferecidas pelas ferramentas CASE Scrum-Half, JUnit, Netbeans e Eclipse, com as principais práticas recomendadas pelas metodologias ágeis no desenvolvimento de aplicações. Para tanto, este trabalho adota um critério de aferição, no qual cada prática avaliada recebe um peso de acordo com o grau de evidências encontrado, e assim, por meio de uma expressão aritmética é possível determinar a aderência de cada prática em relação às ferramentas CASE investigadas. Como contribuição, descreve-se como uma equipe de desenvolvimento pode executar as práticas recomendadas pelos métodos ágeis no desenvolvimento de aplicações com o auxílio da ferramenta CASE mais adequada

    AnĂĄlise da AderĂȘncia das PrĂĄticas Recomendadas pelos MĂ©todos Ágeis: XP, Scrum e TDD com a Utilização de Ferramentas CASE

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    Este artigo especifica uma mĂ©trica para avaliar o nĂ­vel de aderĂȘncia das funcionalidades oferecidas pelas ferramentas CASE Scrum-Half, JUnit, Netbeans e Eclipse, com as principais prĂĄticas recomendadas pelas metodologias ĂĄgeis no desenvolvimento de aplicaçÔes. Para tanto, este trabalho adota um critĂ©rio de aferição, no qual cada prĂĄtica avaliada recebe um peso de acordo com o grau de evidĂȘncias encontrado, e assim, por meio de uma expressĂŁo aritmĂ©tica Ă© possĂ­vel determinar a aderĂȘncia de cada prĂĄtica em relação Ă s ferramentas CASE investigadas. Como contribuição, descreve-se como uma equipe de desenvolvimento pode executar as prĂĄticas recomendadas pelos mĂ©todos ĂĄgeis no desenvolvimento de aplicaçÔes com o auxĂ­lio da ferramenta CASE mais adequada

    Development of an inhalational therapeutical system based on bacteriophages to treat pharyngo-tonsillitis : a nanoencapsulation approach

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    Inflammatory diseases that occur in the pharynx and involving both the adenoids and tonsils are important not only for being very frequent, but also because they often require minor surgery for their resolution. These structures have immunological functions leading to production of antibodies, and work in the local immunity of the pharynx and protection of the entire body. The most common etiologic agent of sore throats is Streptococcus pyogenes, an important pathogen of the beta-hemolytic group A which causes streptococcal pharyngitis. The emergence of antibiotic-resistant bacterial strains and the poor penetration of chemical antibiotics in bacterial biofilms raise the need for safe and effective options of antimicrobial treatment. The application of bacteriophages (or cocktails therefrom) has been proposed as an alternative (or complement) to conventional chemical antibiotics, allowing the release of natural predators of bacteria directly on these biofilms. The major advantage of bacteriophage-based antibiotherapy relative to its conventional chemical counterpart is that bacteriophages replicate at the site of infection, being available in abundance where they are needed the most. When compared with chemical antibiotics, bacteriophages have other important advantages: (i) strong tissue permeability, (ii) bacteriophage concentration remains high at the focus of infection, continuously increasing with bacterial (host) presence, (iii) elimination of the focus of infection occurs only after eradication of the host bacterium, (iv) bacteriophages are fully compatible with antibiotics and may act synergistically, (v) they are specific against the target bacteria, (vi) have a superior ability to penetrate bacterial biofilms, inducing production of enzymes that hydrolyze the biofilm polymeric matrix, (vii) although bacteria can develop resistance to bacteriophages, isolation of new lytic bacteriophages is much simpler and cheaper than developing a new chemical antibiotic. In this research effort, development of a biotechnological process for the inhalational administration of a bacteriophage cocktail (endotoxin free) was pursued, using strategies of nanoencapsulation within lipid nanovesicles (as forms of protection for the bacteriophage against the immune system) to treat infectious pathologies such as pharyngo-tonsillitis caused by Streptococcus pyogenes. This method of targeting may have a high potential for the treatment of bacterial infections of the respiratory tract, since inhalation therapy is considered to be favorable to certain respiratory infections because the aerosol is delivered directly at the site of infection, accelerating the action of bacterial predators. Additionally, a smaller amount of bioactive substance is needed, thus preventing or reducing possible side effects. As a proof of concept for the nanoencapsulation strategy, and since there is not yet available a strictly lytic bacteriophage cocktail for Streptococcus pyogenes, a well-defined and characterized bacteriophage was utilized, viz. bacteriophage T4. Water-in-oil-in-water (W/O/W) multiple emulsions are nanosystems in which dispersions of small water droplets within larger oil droplets are themselves dispersed in a continuous aqueous phase. Due to their compartimentalized internal structure, multiple emulsions present important advantages over simple O/W emulsions for encapsulation of biomolecules, such as the ability to carry both polar and non-polar molecules, and a better control over releasing of therapeutic molecules. T4 bacteriophage was entrapped within W/O/W multiple nanoemulsions, aiming at mimicking the multifunctional design of biology, optimized with several lipid matrices, poloxamers and stabilizing layer compositions. Physicochemical characterization of the optimized bacteriophageencasing nanovesicle formulations encompassed determination of particle size, size distribution and particle charge, via Zeta potential analysis, surface morphology via CRYO-SEM, and thermal analysis via DSC

    Semicircular canal size constrains vestibular function in miniaturized frogs

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    Miniaturization has evolved repeatedly in frogs in the moist leaf litter environments of rainforests worldwide. Miniaturized frogs are among the world’s smallest vertebrates and exhibit an array of enigmatic features. One area where miniaturization has predictable consequences is the vestibular system, which acts as a gyroscope, providing sensory information about movement and orientation. We investigated the vestibular system of pumpkin toadlets, Brachycephalus (Anura: Brachycephalidae), a clade of miniaturized frogs from Brazil. The semicircular canals of miniaturized frogs are the smallest recorded for adult vertebrates, resulting in low sensitivity to angular acceleration due to insufficient displacement of endolymph. This translates into a lack of postural control during jumping in Brachycephalus and represents a physical constraint resulting from Poiseuille’s law, which governs movement of fluids within tubes

    A Formalization of the Theorem of Existence of First-Order Most General Unifiers

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    This work presents a formalization of the theorem of existence of most general unifiers in first-order signatures in the higher-order proof assistant PVS. The distinguishing feature of this formalization is that it remains close to the textbook proofs that are based on proving the correctness of the well-known Robinson's first-order unification algorithm. The formalization was applied inside a PVS development for term rewriting systems that provides a complete formalization of the Knuth-Bendix Critical Pair theorem, among other relevant theorems of the theory of rewriting. In addition, the formalization methodology has been proved of practical use in order to verify the correctness of unification algorithms in the style of the original Robinson's unification algorithm.Comment: In Proceedings LSFA 2011, arXiv:1203.542
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