46 research outputs found

    Asymptotic behaviour of positive large solutions of quasilinear logistic problems

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    We are interested in the asymptotic analysis of singular solutions with blow-up boundary for a class of quasilinear logistic equations with indefinite potential. Under natural assumptions, we study the competition between the growth of the variable weight and the behaviour of the nonlinear term, in order to establish the blow-up rate of the positive solution. The proofs combine the Karamata regular variation theory with a related comparison principle. The abstract result is illustrated with an application to the logistic problem with convection

    A Study of Nonlinear Boundary Value Problem

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    In this chapter, firstly we apply the iterative method to establish the existence of the positive solution for a type of nonlinear singular higher-order fractional differential equation with fractional multi-point boundary conditions. Explicit iterative sequences are given to approximate the solutions and the error estimations are also given. Secondly, we cover the multi-valued case of our problem. We investigate it for nonconvex compact valued multifunctions via a fixed point theorem for multivalued maps due to Covitz and Nadler. Two illustrative examples are presented at the end to illustrate the validity of our results

    A Study for Coupled Systems of Nonlinear Boundary Value Problem

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    This chapter deals with the existence and uniqueness of solutions for a coupled system of fractional differential equations with coupled nonlocal and integral boundary conditions and for the system of two-point boundary value problem when we take the case of integer derivative. The existence results for the fist problem are obtained by using Leray-Shauder nonlinear alternative and Banach contraction principle and for the second problem, we derive explicit eigenvalue intervals of λ for the existence of at least one positive solution by using Krasnosel’skii fixed point theorem. An illustrative examples is presented at the end for each problem to illustrate the validity of our results

    Modeling of CFRP strengthened RC beams using the SNSM technique, proposed as an alternative to NSM and EBR techniques

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    In this paper, an analytical and numerical study in FEM finite element by the ABAQUS software was conducted. Which aims to study the behaviour of RC beams bending strengthened with SNSM side near surface mounted technique, proposed as a solution to avoid the failure mode by debonding of the strengthening, the disadvantage of the EBR externally bonded reinforced technique, and the failure mode by separation of the concrete cover relative to the NSM near surface mounted technique, by comparing the behaviour of the three techniques, the effect of the quantity of strengthening and confirm the results with the literature. The results of this study show that the numerical and analytical model can predict the behaviour of strengthened RC beams according to the three techniques, a clear improvement of the bending capacity of beams strengthened is noticed. A good preservation of the ductility of SNSM beams with a better failure mode

    Existence Results for Boundary Value Problem of Nonlinear Fractional Differential Equation

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    In this chapter, we investigate the existence and uniqueness of solutions for class of nonlinear fractional differential equations with nonlocal boundary conditions. The existence results are obtained by using Leray-Schauder nonlinear alternative and Banach contraction principle. An illustrative example is presented at the end to illustrated the validity of our results

    Finite element based fatigue analysis of 6082 Aluminum alloy under random loading

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    Mechanical and structural components are subject in the most cases during their services to random loading. For this reason, it is necessary to reduce the complex history of these kinds of loading in a series of constant amplitude cycles. There are several counting methods that lead to different results. Among all these methods, it is recognized that the Rainflow Cycle Counting method provides the most conservative results. In this paper, a finite elements analysis technique is presented to predict the fatigue life using this method associate with the S-N method which is used for high cycle fatigue applications that makes no distinction between initiation or growing a crack, but rather, predicts the total life to failure. Comparison between numerical and experimental results is considering in this paper.

    Finite element based fatigue analysis of 6082 Aluminum alloy under random loading

    Get PDF
    Mechanical and structural components are subject in the most cases during their services to random loading. For this reason, it is necessary to reduce the complex history of these kinds of loading in a series of constant amplitude cycles. There are several counting methods that lead to different results. Among all these methods, it is recognized that the Rainflow Cycle Counting method provides the most conservative results. In this paper, a finite elements analysis technique is presented to predict the fatigue life using this method associate with the S-N method which is used for high cycle fatigue applications that makes no distinction between initiation or growing a crack, but rather, predicts the total life to failure. Comparison between numerical and experimental results is considering in this paper.

    Re-thinking Secularism in Post-Independence Tunisia

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    The victory of a Tunisian Islamist party in the elections of October 2011 seems a paradox for a country long considered the most secular in the Arab world and raises questions about the nature and limited reach of secularist policies imposed by the state since independence. Drawing on a definition of secularism as a process of defining, managing, and intervening in religious life by the state, this paper identifies how under Habib Bourguiba and Zine al-Abidine Ben Ali the state sought to subordinate religion and to claim the sole right to interpret Islam for the public in an effort to win the monopoly over religious symbolism and, with it, political control. Both Bourguiba and Ben Ali relied on Islamic references for legitimacy, though this recourse to religion evolved to face changing contexts, and both sought to define Islam on their own terms. Bourguiba sought to place himself personally at the summit of power, while under Ben Ali the regime forged an authoritarian consensus of security, unity, and ‘tolerance’. In both cases the state politicised Islam but failed to maintain a monopoly over religious symbolism, facing repeated religious challenges to its political authority
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