152 resultados para CONVEX
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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What are the fundamental laws for the adsorption of charged polymers onto oppositely charged surfaces, for convex, planar, and concave geometries? This question is at the heart of surface coating applications, various complex formation phenomena, as well as in the context of cellular and viral biophysics. It has been a long-standing challenge in theoretical polymer physics; for realistic systems the quantitative understanding is however often achievable only by computer simulations. In this study, we present the findings of such extensive Monte-Carlo in silico experiments for polymer-surface adsorption in confined domains. We study the inverted critical adsorption of finite-length polyelectrolytes in three fundamental geometries: planar slit, cylindrical pore, and spherical cavity. The scaling relations extracted from simulations for the critical surface charge density sigma(c)-defining the adsorption-desorption transition-are in excellent agreement with our analytical calculations based on the ground-state analysis of the Edwards equation. In particular, we confirm the magnitude and scaling of sigma(c) for the concave interfaces versus the Debye screening length 1/kappa and the extent of confinement a for these three interfaces for small kappa a values. For large kappa a the critical adsorption condition approaches the known planar limit. The transition between the two regimes takes place when the radius of surface curvature or half of the slit thickness a is of the order of 1/kappa. We also rationalize how sigma(c)(kappa) dependence gets modified for semi-flexible versus flexible chains under external confinement. We examine the implications of the chain length for critical adsorption-the effect often hard to tackle theoretically-putting an emphasis on polymers inside attractive spherical cavities. The applications of our findings to some biological systems are discussed, for instance the adsorption of nucleic acids onto the inner surfaces of cylindrical and spherical viral capsids.
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The genus Habronema has four valid species, of which only two are properly known. The present study aimed to describe in detail the morphology of Habronema clarki through optical and scanning electron microscopy analyses. Our results showed that the labial morphology of this parasite is closer to H. muscae than to H. microstoma. Even so, the characteristic pseudolabia and the slightly convex border of the dorsal and ventral lips are sufficient to distinguish these nematodes. Additional morphological data are presented, thus contributing to the knowledge on this little known nematode. In addition, this study provides new locality records for this species.
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In this work a Nonzero-Sum NASH game related to the H2 and H∞ control problems is formulated in the context of convex optimization theory. The variables of the game are limiting bounds for the H2 and H∞ norms, and the final controller is obtained as an equilibrium solution, which minimizes the `sensitivity of each norm' with respect to the other. The state feedback problem is considered and illustrated by numerical examples.
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Pós-graduação em Matemática em Rede Nacional - IBILCE
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A model for the joint economic design of X̄ and R control charts is developed. This model assumes that the process is subject to two assignable causes. One assignable cause shifts the process mean; the other shifts the process variance. The occurrence of the assignable cause of one kind does not block the occurrence of the assignable cause of another kind. Consequently, a second process parameter can go out-of-control after the first process parameter has gone out-of-control. A numerical study of the cost surface to the model considered has revealed that it is convex, at least in the interest region.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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The zygomatic-maxillary complex due to its projection framed as one of the areas hardest hit by injuries, as well as the nasal bones. Component important in this context, the zygomatic arch fracture is under the direct action of forces due to its structure fragile, resulting in loss of normal convex curvature. Therefore, it is aimed to report a clinical case of male patient, who had leucoderma zygomatic bone fracture using access transcutaneous and intra-oral fracture reduction body of zygoma and zygomatic arch. In addition to evidence combination of closed and open techniques for solving the case. The technique provided the patient excellent cosmetic and functional results.
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Introduction: The zygomatic maxillary complex is the second most affected area of the face due to injuries, surpassed only by the nasal bones. The zygomatic arch fracture is under the direct action of trauma (punch, head butt), its fragile structure, losing its normal convex curvature in the temporal area. Objective: To report a case, using a reduction technique of zygomatic arch fracture using a hook or Ginestet Barros. Case report: A male patient, 25 years of age, leukoderma, showing zygomatic arch fracture right. The patient underwent closed reduction with the hook adapted to the skin. The patient was instructed to keep care of the region for at least four weeks
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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The common practice in industry is to perform flutter analyses considering the generalized stiffness and mass matrices obtained from finite element method (FEM) and aerodynamic generalized force matrices obtained from a panel method, as the doublet lattice method. These analyses are often reperformed if significant differences are found in structural frequencies and damping ratios determined from ground vibration tests compared to FEM. This unavoidable rework can result in a lengthy and costly process of analysis during the aircraft development. In this context, this paper presents an approach to perform flutter analysis including uncertainties in natural frequencies and damping ratios. The main goal is to assure the nominal system’s stability considering these modal parameters varying in a limited range. The aeroelastic system is written as an affine parameter model and the robust stability is verified solving a Lyapunov function through linear matrix inequalities and convex optimization
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Pós-graduação em Agronomia (Produção Vegetal) - FCAV
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Pós-graduação em Geografia - FCT
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Pós-graduação em Agronomia (Ciência do Solo) - FCAV