1,274 research outputs found

    Reading of the evolution of the urban shape of the Plateau - City of Praia

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    An analysis of urban morphology of the historical nucleus (the Plateau) of Praia (Cape Verde) highlights the process of thinking and making a city expressed in António de Lencastre 's plan and its further development. For this, the processes of urban transformation occurring over time in the Plateau are shown. The methodology used for this urban analysis allowed an understanding of the intervention process on the Plateau through an interpretative analysis of morphological evolution obtained from: i) a detailed identification of cartography; ii) a comparative morphological analysis of urban development based on old and current cartography; iii) a vectorization of the maps through scale normalization (the letters were overlapped with the 2018 chart); iv) an identification of public buildings and public spaces; and v) a quantification of the elements of urban form. In the quantification of the elements of the urban form, the reading and interpretation of the different maps is synthesized through analytical drawings and tables.info:eu-repo/semantics/publishedVersio

    Multiphase elastic homogenization, and the mechanics of tendon-to-bone attachment

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    Estimates of the effective stiffness of a composite containing multiple types of inclusions are needed for the design and study of functionally graded systems in engineering and biologic materials. One important stiffening mechanism in biologic systems is the accumulation of a high volume fraction of mineral inclusions within and upon collagen fibers. Modeling of this mechanism is critical for understanding how stresses are transmitted from tendon to bone and for designing improvements to surgical procedures for reattaching tendon to bone. The latter is a critical need because failure rates following surgical reattachment are as high as 94% in some populations. Modeling of such material remains difficult Because of a number of physiological and mathematical challenges. A range of methods have been described in the literature for estimating the effective elastic properties of composites containing low volume fractions of different inclusion types. Here, we provide an estimate of the effective elastic responses of composites containing high volume fractions of different, ellipsoidal and anisotropic inclusion types. The homogenization estimate compared well against numerical simulation and available experimental data. The method out-performed all methods of which we are aware for modeling of numerical simulations of the mechanical response of the graded attachment of tendon to bone. The method is a good candidate for the characterization of composites with multiple types of anisotropic inclusions, even if these inclusions have moderate volume fractions and a variety of aspect ratios

    The Concentration of Stress at the Rotator Cuff Tendon-to-Bone Attachment Site Is Conserved across Species

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    The tendon-to-bone attachment site integrates two distinct tissues via a gradual transition in composition, mechanical properties, and structure. Outcomes of surgical repair are poor, in part because surgical repair does not recreate the natural attachment, and in part because the mechanical features that are most critical to mechanical and physiological function have not been identified. We employed allometric analysis to resolve a paradox about how the architecture of the rotator cuff contributes to load transfer: whereas published data suggest that the mean muscle stresses expected at the tendon-to-bone attachment are conserved across species, data also show that the relative dimensions of key anatomical features vary dramatically, suggesting that the amplification of stresses at the interface between tendon and bone should also vary widely. However, a mechanical model that enabled a sensitivity analysis revealed that the degree of stress concentration was in fact highly conserved across species: the factors that most affected stress amplification were most highly conserved across species, while those that had a lower effect showed broad variation across a range of relative insensitivity. Results highlight how micromechanical factors can influence structure-function relationships and cross-species scaling over several orders of magnitude in animal size, and provide guidance on physiological features to emphasize in surgical and tissue engineered repair of the rotator cuff
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