LOADng-AT: a novel practical implementation of hybrid AHP-TOPSIS algorithm in reactive routing protocol for intelligent IoT-based networks

The Journal of Supercomputing - Despite that IoT technology provides a promising future for human life, some significant challenges such as routing, security, low-cost equipment, energy...     

A computational method for solving two‐dimensional nonlinear variable‐order fractional optimal control problems

In this paper, a new class of two‐dimensional nonlinear variable‐order fractional optimal control problems (V‐OFOCPs) is introduced where the variable‐order fractional derivative is defined in the Caputo type. The general procedure for solving theses systems is expanding the state variable and the control variable based on the Legendre cardinal functions in the matrix form. Hence, we derive their operational matrix of derivative (OMD) and operational matrix of variable‐order fractional derivative (OMV‐OFD). More significantly, some properties of these basis functions are proved to be exploited in our approach. Using these achieved results, we simply expand the matrix form of the nonlinear performance index in terms of the Legendre cardinal functions and subsequently convert it to an algebraic equation. We emphasize that it is a valuable advantage of applying cardinal functions in approximation theory. Then, we implement the OMD and the OMV‐OFD of the Legendre cardinal functions to transform the variable‐order fractional dynamical system to a system of algebraic equations. Next, the method of constrained extremum is applied to adjoin the constraint equations including the given dynamical system and the initial‐boundary conditions to the performance index by a set of undetermined Lagrange multipliers. Finally, the necessary conditions of the optimality are derived as a system of nonlinear algebraic equations including the unknown coefficients of the state variable, the control variable and the Lagrange multipliers. The applicability and efficiency of the proposed approach are investigated through the various types of test problems.     

Mesoporous MCM-41-nPr-NHSO3H as novel and effective nanoreactor catalyst for the synthesis of multi-substituted imidazoles under solvent-free conditions

Journal of Porous Materials - Herein, we report the synthesis and application of mesoporous siliceous MCM-41-nPr-NHSO3H, which was characterized by XRD, IR, TGA and nitrogen physisorption...     

Synthesis of Ni(II)-3,5-dichloro-2-hydroxybenzenesulfonyl chloride supported SBA-15 and its application as a nanoreactor catalyst for the synthesis of diaryl sulfides via reaction of aryl halides with thiourea or S<Subscript>8</Subscript>

In the present work, SBA-15 mesoporous grafted with 3-(trimethoxysilyl)-1-propanethiol as a linker and subsequently reacted by 3, 5-dichloro-2-hydroxybenzenesulfonyl chloride. Then to obtain the new catalyst Ni(II) was supported on functionalized SBA-15 by using Ni(NO₃)₂ as Ni(II) source. The Ni/SBA-15 catalyst was characterized with SEM, EDS, ICP, XRD, TGA, FT-IR and N₂ sorption–desorption analysis. The key advantages of this heterogeneous catalyst are inexpensive, short reaction times, excellent yields, recovery and reusability.     

Zr (IV)-ninhydrin supported MCM-41 and MCM-48 as novel nanoreactor catalysts for the oxidation of sulfides to sulfoxides and thiols to disulfides

Modification of MCM-41 and MCM-48 mesoporous materials with bonded aminosilane species, Schiff base preparation by ninhydrin and finally complexation with zirconium, has attracted much attention in order to design catalyst with advanced applications in the oxidation of sulfides to sulfoxides and thiols to disulfides in the presence of hydrogen peroxide. In all oxidation of sulfides to sulfoxids 0.4 mL H₂O₂ used as oxidant in the presence of Zr(IV)-ninhydrin supported MCM-41 (0.01 g) or Zr(IV)-ninhydrin supported MCM-48 (0.005 g) at room temperature and solvent-free condition. Also the best conditions for oxidation of thiols to disulfides with 0.4 mL H₂O₂ were 0.005 g Zr(IV)-ninhydrin supported MCM-41 or Zr(IV)-ninhydrin supported MCM-48 at room temperature and in ethanol. These catalysts are characterized by SEM, XRD, TGA, FT-IR, EDS, ICP and BET analysis. Also the Turn over frequency (TOF) and Turn over number (TON) of catalysts are calculated. Obtained results by these heterogeneous catalysts revealed several advantages including short reaction times, simple workup, easy isolation and reusability.     

Shaking table tests on polymeric-strip reinforced-soil walls adjacent to a rock slope

This research adopts the approach to constructing reinforced-soil walls on rock slope, where the extent of reinforced zone has to be constrained since excavation of the relatively rigid zone may not be economical and may disrupt the traffic. To examine the seismic behavior of these structures, a series of 1-g shaking table tests using variable-amplitude harmonic excitations was conducted on 0.8m-high polymeric-strip reinforced-soil walls (PSWs) on rock slope under a scenario of waves with different intensities. Rock slope appeared to have a satisfactory dynamic response compared to the soil base as the rock behind the reinforced zone controls the development of active wedge failure and prevents higher amplification and progressive deformation. The results illustrated that the confining pressure and reinforcement length considerably affect the shear modulus and damping ratio. Also, it was found that in PSWs on rock with L/H ratio of 0.3 for bottom strips, the lowest facing panel, having the maximum horizontal displacements after failure, and lower maximum shear modulus (G_max), and damping ratio (D), is the most crucial one despite having the highest confining pressure representing the profound effect of L/H ratio when it equals 0.3.     

A new Wavelet Method for Variable‐Order Fractional Optimal Control Problems

In this paper, a new computational method based on the Legendre wavelets (LWs) is proposed for solving a class of variable‐order fractional optimal control problems (V‐FOCPs). To do this, a new operational matrix of variable‐order fractional integration (OMV‐FI) in the Riemann‐Liouville sense for the LWs is derived and used to obtain an approximate solution for the problem under study. Along the way the hat functions (HFs) are introduced and employed to derive a general procedure to compute this matrix. In the proposed method, the variable‐order fractional dynamical system is transformed to an equivalent variable‐order fractional integro‐differential dynamical system, at first. Then, the highest integer order of the derivative of the state variable and the control variable are expanded by the LWs with unknown coefficients. Next, the OMV‐FI in the the Riemann‐Liouville sense together with some properties of the LWs are employed to achieve a nonlinear algebraic equation in place of the performance index and a nonlinear system of algebraic equations in place of the dynamical system in terms of the unknown coefficients. Finally, the method of constrained extremum is applied which consists of adjoining the constraint equations derived from the given dynamical system to the performance index by a set of undetermined Lagrange multipliers. As a result, the necessary conditions of optimality are derived as a system of algebraic equations in the unknown coefficients of the state variable, control variable and Lagrange multipliers. Furthermore, the efficiency and accuracy of the proposed method are demonstrated for some concrete examples. The obtained results show that the proposed method is very efficient and accurate.     

Solving a category of two-dimensional fractional optimal control problems using discrete Legendre polynomials

In this paper, we formulate a numerical method to approximate the solution of two-dimensional optimal control problem with a fractional parabolic partial differential equation (PDE) constraint in the Caputo type. First, the optimal conditions of the optimal control problems are derived. Then, we discretize the spatial derivatives and time derivatives terms in the optimal conditions by using shifted discrete Legendre polynomials and collocations method. The main idea is simplifying the optimal conditions to a system of algebraic equations. In fact, the main privilege of this new type of discretization is that the numerical solution is directly and globally obtained by solving one efficient algebraic system rather than step-by-step process which avoids accumulation and propagation of error. Several examples are tested and numerical results show a good agreement between exact and approximate solutions.     

Synthesis and Characterization of Magnetic Functionalized Ni and Cu Nano Catalysts and Their Application in Oxidation,Oxidative Coupling and Various Multi-Component Reactions

Catalysis Letters - Two magnetic nano catalysts of nickel and copper, Fe3O4@SiO2@DOP-BenPyr-M(II), (M=Ni and Cu) have been synthesized. These catalysts were applied as recoverable, efficient and...