فهرست مطالب

  • Volume:10 Issue:2, 2019
  • تاریخ انتشار: 1398/04/10
  • تعداد عناوین: 6
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  • Dariush Heidari *, Davood Mazaheri, Bijan Davvaz Pages 93-102
    A salt metathesis reaction is a chemical process involving the exchange of bonds between two reacting chemical species, which results in the creation of products with similar or identical bonding affiliations. Hyperstructure theory is studied from the theoretical point of view and for its applications. In this paper, we provide some examples of hyperstructures associated with salt metathesis reactions, and we observe that these chemical reactions are examples of the phenomena when composition of two elements is a set of elements.
    Keywords: Hyperstructures, semihypergroup, $H, v$-semigroup, salt reaction
  • Gholam Askarirobati, Aghileh Heydari, Akbar Hashemi * Pages 103-126

    Evolutionary algorithms have been recognized to be suitable for extracting approximate solutions of multi-objective problems because of their capability to evolve a set of non-dominated solutions distributed along the Pareto frontier‎. ‎This paper applies an evolutionary optimization scheme‎, ‎inspired by Multi-objective Invasive Weed Optimization (MOIWO) and Non-dominated Sorting (NS) strategies‎, ‎to find approximate solutions for multi-objective optimal control problems (MOCPs)‎. ‎The desired control function may be subjected to severe changes over a period of time‎. ‎In response to deficiency‎, ‎the process of dispersal has been modified in the MOIWO‎. ‎This modification will increase the exploration power of the weeds and reduces the search space gradually during the iteration process‎. ‎ ‎The performance of the proposed algorithm ‎is compared with conventional Non-dominated Sorting Genetic Algorithm (NSGA-II) and Non-dominated Sorting Invasive Weed Optimization (NSIWO) algorithm‎.The results show that the proposed algorithm has better performance than others in terms of computing time‎, ‎convergence rate and diversity of solutions on the Pareto ‎frontier.

    Keywords: Multi-objective optimal ‎control, Pareto optimal ‎frontier, Non-dominated ‎sorting, invasive weed optimization, Fed Batch Reactor
  • Bommanahal Basavanagoud *, Anand Barangi, Praveen Jakkannavar Pages 127-150
    In this paper, we obtain M-polynomial of some graph operations and cy- cle related graphs. As an application, we compute M-polynomial of some nanostruc- tures viz., TUC4C8[p; q] nanotube, TUC4C8[p; q] nanotorus, line graph of subdivision graph of TUC4C8[p; q] nanotube and TUC4C8[p; q] nanotorus, V-tetracenic nanotube and V-tetracenic nanotorus. Further, we derive some degree based topological indices from the obtained polynomials.
    Keywords: M-polynomial, Degree-based topological index, line graph, subdivision graph, wheel graph
  • Ali Ghalavand * Pages 151-159
    The Wiener index W and the edge-Wiener index W_e of G are defined as the sum of distances between all pairs of vertices in G and the sum of distances between all pairs of edges in G, respectively. In this paper, we identify the four trees, with the first through fourth greatest Wiener and edge-Wiener index among all trees of order n ≥ 10.
    Keywords: tree, Wiener index, edge-Wiener index, Graph operation
  • Morteza Rezaei, Esmat Mohammadinasab * Pages 161-179
    In this study, multiple linear regression method that is based on property-structure model has been used to predict the standard enthalpies of formation for the gas and liquid phases of the 33 different types of amines. It was indicated that among studied topological and geometric descriptors to predict the ∆H˚f(liquid), descriptors as PSA, H, MaxZL and V have more importance than the other descriptors. Also, the results of experiments on studied amines were compared with the results of multiple linear regression calculations and it was observed that such descriptors as MaxZL MaxPA, DE, J and WW are the best descriptors for predicting the values of ∆H˚f(gas) of this class of amines.
    Keywords: Amines Derivatives, Standard Enthalpy of Formation, Molecular Descriptors, chemometrics
  • Ali Shokri, Maryam Molayi, Mohammad Mehdizadeh * Pages 181-193

    In this paper, we present a new class of hybrid methods for the numerical solution of first order ordinary differential equations (ODEs). The accuracy and stability properties of the new methods are investigated. In the final section, we apply new hybrid methods to solve two stiff chemical problems such as Roberston problem.

    Keywords: Stiff initial value problems, Hybrid methods, Roberston problem, A-Stability, L-Stability