In this paper, A innovative method designed to solving nonlinear optimization problems with convex object function and constrained. In this method, we define an cost function and we find variables to minimization of cost function. For create properly cost function we use K. K. T. optimal conditions. We used Nelder-Mead without derivative optimization method to minimization of cost function. When, dimensions of problem is about 10, application shows that efficiency of Nelder-Mead method is more than the other methods. Using new mathod is easier than the similar methods. By several examples efficiency of new method are verified.

In this paper, the effect of angle between predictor and corrector surfaces on the structural analysis is investigated. Two objective functions are formulated based on this angle and also the load factor. Optimizing these functions, and using the structural equilibrium path’s geometry, lead to two new constraints for the nonlinear solver. Besides, one more formula is achieved, which was previously found by other researchers, via a different mathematical process. Several benchmark structures, which have geometric nonlinear behavior, are analyzed with the proposed methods. The finite element method is utilized to analyze these problems.The abilities of suggested schemes are evaluated in tracing the complex equilibrium paths.Moreover, comparison study for the required number of increments and iterations is performed. Results reflect the robustness of the authors’ formulations.

In this paper we consider unconstraint optimization problem as representation theorem and a control problem. Then by using Riesz admissible paires of control and state we transfer the problem to a problem in measure space. Then the problem is reduced to an infinitedimensional linear programming. The later problem is approximatedto a finite-dimentional linear programming and then by the solution of this linear programming we obtain the approximate optimal control function as a piecewise constant function. Then we optimal control function. The final end point of this trajectory is an approximate solution of the original unconstraint optimization problem. Finally we consider the optimization problems with constraints. We compare the approximate solution obtained by this method by approximate solutions obtained by some other well-known methods. At the end we solve some examples by this method to show the efficiency of this method.

In this paper, recommended spiral passive micromixer was designed and simulated. spiral design has the potential to create and strengthen the centrifugal force and the secondary flow. A series of simulations were carried out to evaluate the effects of channel width, channel depth, the gap between loops, and flowrate on the micromixer performance. These features impact the contact area of the two fluids and ultimately lead to an increment in the quality of the mixture. In this study, for the flow rate of 25 μl/min and molecular diffusion coefficient of 1×10-10 m2/s, mixing efficiency of more than 90% is achieved after 30 (approximately one-third of the total channel length). Finally, the optimized design fabricated using proposed 3D printing method.

Application of the network equivalent concept for external system representation for power system transient analysis is well known. However, the challenge to utilize an equivalent network, approximated by a rational function, is to guarantee the passivity of the corresponding model. In this regard, special techniques are required to enforce the passivity of the equivalent model through a post processing approach that minimizes its impact on the original model characteristics. In this paper, the passivity is enforced by expressing the problem in terms of a convex optimization problem that guarantees the global optimal solution. The convex optimization problem is efficiently solved by recently developed numerical interior–point methods. This passivity enforcement is also global which indicates that the passivity enforcement in one region does not lead to passivity violation in other regions.

Department of Civil Engineering, Iran University of Science and Technology Tehran, The fundamentals of electrokinetic (EK) remediation, including removal efficiency from two kinds of contaminated clays, artificially polluted by phenol, were investigated in the laboratory. Results of two one-dimensional tests with initial phenol concentration of 950 ppm (below the adsorption' capacity of clays) are presented in this paper. Besides, soil samples were prepared from Tehran Refinery region to investigate the effects of EK on naturally polluted clay by petroleum hydrocarbons. Results indicated that phenol removal was depended on the ion concentration in clay texture and adsorption capacity of phenol. The phenol removal from 20-80% was achieved in different soils. The results clearly demonstrated that in the case of phenol contaminant, higher removal efficiency was achieved in clay with lower cation concentration. For samples prepared from Tehran Refinery region, EK could not extract petroleum hydrocarbons from soil although a 25% (by volume) mixture of methanol-distilled water was used in anode chamber to conduct in soil texture during electroomotic flow. Adding the methanol to soil texture before the test causes that little volume of petroleum hydrocarbons moved toward the cathode in 40% of sample length and accommodated near the cathode.