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.

How to profoundly change the beliefs of the polytheists during the age of revelation from the denial of the Prophet (pbuh) to the certainty of his Message and the acceptance of his full guardianship is a question worthy of attention. The order of verses about prophecy based on the order of revelation is the reason to lead a transformative Process and a special Quranic method in institutionalizing the belief of prophecy in the lives of Arabs. In the first stage, the Holy Quran in the first Makkī (Arabic: المکّیّ, suras revealed in Mecca) chapters has prepared the community from the motivational side to accept the truth of the Prophet’s (pbuh) prophecy and briefly stating the key issues surrounding it. The Holy Book of Quran at the time of the emergence of oppositions and doubts (the second stage) destroyed the arguments of the polytheists and explained the prophecy and proved its authenticity from a cognitive perspective in the second stage by presenting clear arguments. and the Holy Book of Quran in the third stage after Madanī (Arabic: المدنیّ, suras revealed in Medina) period has undertaken measures in order to fulfill the goals of the Massage by explaining the true position of the Prophet (pbuh) to deepen and operationalize the Prophetic belief through explaining practical duties for the Prophet (pbuh) and behavior based on the acceptance of Walaya (Arabic: ولایة, meaning “guardianship” or “governance”).

Oil refineries are facing the ever-strict restriction in terms of fuel specification in view of the several policies by the environmental impact agency (EIA). Strict rules have been enforced on the gasoline product specification. Isomerization is one of the key Processes for increasing the octane number of gasoline. Hence a case study has been performed using the concept of hydrogen once-through technology to analyze the Process constraints for optimal operation of the Process using Aspen HYSYS. In addition to this, a rigorous Process model of isomerate stabilizer was also used to compare the results of the stabilizer model and optimize those various variables affecting the octane number of gasoline. The model was validated by observing the effects of constraints on the efficiency of the Process by comparing it with the operational isomerization unit to further verify the authenticity of the case study. Furthermore, a calculator has been generated for the reactor temperature with respect to high benzene contents in the feedstock (benzene in feed Vs reactors Δ T).

The simultaneous optimization of multiple responses is an important problem in the design of industrial Processes in order to achieve improved quality. In this paper, we present a new metaheuristic approach including Simulated Annealing and Particle Swarm optimization to optimize all responses simultaneously. For the purpose of illustration and comparison, the proposed approach is applied to two problems taken from the literature. The results of our study show that the proposed approach outperforms the other approaches and can find better solutions.Finally, in both cases, we present the results of a sensitivity analysis incorporating experimental design.

The caged polynitramine explosive (CL-20) is one of the most powerful explosives whose performance parameters such as pressure and velocity of detonation, heat of formation, penetration and density are higher than the other common explosives. In this paper, all the synthetic methods and the explosion parameters of CL-20 have been reviewed and the most convenient method has been selected, clarified and optimized. Also, optimizing parameters such as crystallization solvents for CL-20 (ethyl acetate-heptane) and its intermediates (for HBIW, ethyl acetate), reaction temperature (for converting HBIW to TADB, 38-42oC), and catalyst (Pd/C, 5% wet), a new nitration composition (nitric acid-sulforic acid, with ratio 1:1) has been introduced.

In GTL Process -the conversion of gas to liquid products- a great amount of energy is released.Meanwhile, the various warm and cool streams in this Process with their significant temperature difference can internally supply the required energy of the system. In fact, the GTL Process has the potential to produce a considerable amount of energy far beyond its needs. The excess energy is so much that it can even run a power plant. In other words, the Process of converting natural gas to liquid hydrocarbons not only is self-sufficient from an energy point of the view, but also can produce energy.In this paper, various approaches to energy optimization in a GTL unit with a capacity of 10, 000 BPD are studied using optimizer software at different stages of the Process. Then, the most suitable method is selected and the amount of the generated energy is calculated and reported. Finally, an integrated network of heat exchangers is suggested.

Formal portfolio optimization methodologies describe the dynamics of financial instruments price with Gaussian Copula (GC). Regardless of the skewness and kurtosis of assets return rate, optimization with GC underestimates the optimal CVaR of portfolio. In the present paper, we develop an approach to portfolio optimization by introducing Lé vy Processes. It focuses on describing the dynamics of assets’ log price with Variance Gamma copula (VGC) rather than GC. Doing a case study on three Indexes of Iran Stock Market, the best hedge positions of Total Index, Market Index and Industry Index with the performance function CVaR under VG model were calculated. The results indicate that (a) VG copula can efficiently overcome the shortcomings of Gaussian copula which underestimates the CVaR of portfolio; (b) optimal portfolio, VaR and CVaR keep stable each time one parameter of sample’ s skewness or kurtosis was changed, but the optimal portfolio change significantly when the sample’ s mean increases or decreases; (c) different copula lead to different optimal CVaR; and (d) fat-tailedness and kurtosis are extremely important in portfolio optimization framework.