191,899 research outputs found

    Cyclization and self-assembly of cyclic peptides

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    Part of the Methods in Molecular Biology book series (MIMB,volume 2371)Cyclic peptides are a fascinating class of molecules that can be programmed to fold or self-assemble into diverse mono- and multidimensional structures with potential applications in biomedicine, nanoelectronics, or catalysis. Herein we describe on-resin procedures to carry out head-to-tail peptide cyclization based on orthogonal protected linear structures. We also present essential characterization tools for obtaining dynamic and structural information, including the visualization cyclic peptide assembly into nanotubes (AFM, TEM) as well as the use of fluorescence microscopy2023-10-0

    Self-Dual and Complementary Dual Abelian Codes over Galois Rings

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    Self-dual and complementary dual cyclic/abelian codes over finite fields form important classes of linear codes that have been extensively studied due to their rich algebraic structures and wide applications. In this paper, abelian codes over Galois rings are studied in terms of the ideals in the group ring GR(pr,s)[G]{\rm GR}(p^r,s)[G], where GG is a finite abelian group and GR(pr,s){\rm GR}(p^r,s) is a Galois ring. Characterizations of self-dual abelian codes have been given together with necessary and sufficient conditions for the existence of a self-dual abelian code in GR(pr,s)[G]{\rm GR}(p^r,s)[G]. A general formula for the number of such self-dual codes is established. In the case where gcd(G,p)=1\gcd(|G|,p)=1, the number of self-dual abelian codes in GR(pr,s)[G]{\rm GR}(p^r,s)[G] is completely and explicitly determined. Applying known results on cyclic codes of length pap^a over GR(p2,s){\rm GR}(p^2,s), an explicit formula for the number of self-dual abelian codes in GR(p2,s)[G]{\rm GR}(p^2,s)[G] are given, where the Sylow pp-subgroup of GG is cyclic. Subsequently, the characterization and enumeration of complementary dual abelian codes in GR(pr,s)[G]{\rm GR}(p^r,s)[G] are established. The analogous results for self-dual and complementary dual cyclic codes over Galois rings are therefore obtained as corollaries.Comment: 22 page

    Experimental tests for seismic assessment and strengthening of adobe structures

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    Adobe structures present very appealing characteristics regarding a more sustainable practice with the preservation of our natural resources. However, when subjected to cyclic horizontal actions, such as earthquakes, they can present a deficient behaviour. With the purpose of evaluating the seismic vulnerability of adobe structures, a series of tests were conducted on a full-scale adobe wall considering constant dead and live loads combined with cyclic horizontal actions with rising amplitude. A structural strengthening solution was tested on the repaired wall after its assessment test. The adopted repair solution, based on cracks injection, combined with the strengthening solution, proved to be very efficient in improving the performance of the adobe wall. With the study conducted, it was possible to contribute to the characterization of adobe structural walls in terms of deformation capacity and failure modes, establishing the basis for the calibration of numerical models for adobe structures

    A damaging block-based model for the analysis of the cyclic behaviour of full-scale masonry structures

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    In this paper, a damaging block-based model is proposed for the numerical analysis of the cyclic behaviour of full-scale masonry structures. Solid 3D finite elements governed by a plastic-damage constitutive law in tension and compression are used to model the blocks, while a cohesive-frictional contact-based formulation is developed to simulate their cyclic interaction. The use of tests on small-scale specimens to calibrate the mechanical properties of the numerical model is presented and discussed. The tests belong to a comprehensive experimental campaign performed on calcium silicate brick masonry. The calibrated models are used to simulate in-plane and out-of-plane cyclic tests on masonry walls made of the same material, as well as a quasi-static cyclic pushover test on a full-scale terraced masonry house. The efficiency, the potentialities and the accuracy of the model here proposed are shown and discussed. The capability of explicitly representing structural details (e.g. running bonds) and any in-plane and through-thickness texture of masonry, which appears essential to study the response of masonry structures, is guaranteed by the block-based modelling approach. A good agreement between the numerical results and the experimental outcomes is observed. This allows to validate the model in the cyclic response as well as the strategy proposed for its mechanical characterization

    Design and optimisation of 3D fast printed cellular structures

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    This paper analyzes the effect of thin and thick walls on functional properties of 3D printed cell structures, designed from open cell structures inspired by the natural world. Different types of unit cells with the same density are introduced. The cells are studied in morphology and mechanical performance, in particular effective density, compressive stiffness, and energy absorption under cyclic loading. Material extrusion process with thermoplastic polyurethane filament is used as additive manufacturing technique, without any support structure. The designed printed cellular structures are studied numerically, using an advanced hyperelastic material model with hysteretic capacity, and experimentally by uniaxial compression testing for characterization of stiffness and energy absorption. The benefits and limitations of the method are highlighted

    Fully Observable Non-deterministic Planning as Assumption-Based Reactive Synthesis

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    We contribute to recent efforts in relating two approaches to automatic synthesis, namely, automated planning and discrete reactive synthesis. First, we develop a declarative characterization of the standard “fairness” assumption on environments in non-deterministic planning, and show that strong-cyclic plans are correct solution concepts for fair environments. This complements, and arguably completes, the existing foundational work on non-deterministic planning, which focuses on characterizing (and computing) plans enjoying special “structural” properties, namely loopy but closed policy structures. Second, we provide an encoding suitable for reactive synthesis that avoids the naive exponential state space blowup. To do so, special care has to be taken to specify the fairness assumption on the environment in a succinct manner.Fil: D'ippolito, Nicolás Roque. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Investigación en Ciencias de la Computación. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Investigación en Ciencias de la Computación; ArgentinaFil: Rodriguez, Natalia. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Computación; ArgentinaFil: Sardina, Sebastian. RMIT University; Australi
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