Sharif Digital Repository

In the present work, a fuzzy supervisory control approach combined with an adaptive model predictive controller (AMPC), has been proposed to maximize the productivity of an anaerobic digestion (AD) process, while keeping the operation stable. In the proposed hierarchal control strategy, the set-point of the inner loop is provided by a supervisory controller. In the inner loop an AMPC has been applied to achieve the desired methane production rate by manipulating the feed flow rate. The AMPC is designed based on the auto-regressive moving average (ARMA) model whose parameters are updated at each sampling time to make the controller more robust against uncertainties and external loads. In the... 

The authors regret Acknowledgement: The authors would like to express his gratitude to Iran National Science Foundation (INSF) for supporting this research under grant number 92037628. The authors would like to apologise for any inconvenience caused. © 2019 Elsevier B.V  

Heavy and extra heavy crude oils usually have a high weight percentage of asphaltene, which could induce many problems during production to refining processes. Also, asphaltene has the main role on the high viscosity of the heavy and extra heavy crude oils. In this paper, the effects of asphaltene characteristics on the crude oil rheological properties have been experimentally and theoretically investigated using different classes of the suspension models. For experimental investigation, the asphaltene was first precipitated from the original heavy crude oil and then 10 well-defined reconstituted heavy oil samples are made by dispersing the asphaltene into the maltene (i.e., deasphalted... 

The present study investigated the effect of laser input energy on the quality and mechanical behavior of a 304 stainless steel–polyamide 6 joint in the laser-assisted metal and polymer direct joining (LAMP) method experimentally and numerically. After the proposed heat transfer model was validated, it was determined whether there was an optimal amount of laser input energy that could produce a joint with favorable quality and mechanical behavior. Among different laser input energies used in this study, 28-J/mm energy can provide more uniform and extensive wetting of the metal surface by the polymer, while excessive polymer degradation in the joint zone was prevented. As a result, an optimal... 

Among the factors affecting the efficiency of laser-assisted metal and polymer (LAMP) joints, the surface condition of the joint components is one of the most important ones. So, the present study explored the effect of laser pre-oxidation of stainless steel 304 (SS304), as a novel pretreatment method, on SS304/polyamide 6 joint strength. The assessments revealed that in spite of the potential of surface pre-oxidation of SS304 for improving joint strength, the strength of the joint was reduced by ∼ 25 % in practice because, firstly, the wettability of the metal by the polymer was reduced due to the reduction of heat transfer by the metal in the preoxidized zone and secondly, the oxide layer... 

The COVID-19 epidemic is spreading day by day. Early diagnosis of this disease is essential to provide effective preventive and therapeutic measures. This process can be used by a computer-aided methodology to improve accuracy. In this study, a new and optimal method has been utilized for the diagnosis of COVID-19. Here, a method based on fuzzy C-ordered means (FCOM) along with an improved version of the enhanced capsule network (ECN) has been proposed for this purpose. The proposed ECN method is improved based on mayfly optimization (MFO) algorithm. The suggested technique is then implemented on the chest X-ray COVID-19 images from publicly available datasets. Simulation results are... 

The highly viscous property of heavy oil often causes problems in its transportation in pipelines. Mixing heavy oil with light oil as well as ultrasound treatment are viable solutions to this problem. In this study, extra heavy crude oil samples were first diluted with 0, 0.05, 0.1, and 0.15 mL/mL (0, 5, 10, and 15 vol%) of a light crude oil; then the mixture was irradiated by ultrasonic waves for 0, 5, 10, 15, and 20 min; finally the viscous shear functions of all mixtures was measured at different values of shear rate at different temperature levels. The results revealed that the minimum viscosity of the diluted extra heavy crude oil samples was obtained at 10 min of ultrasonic... 

Usually, resources are short in supply when earthquakes occur. In such emergency situations, disaster relief organizations must use these scarce resources efficiently to achieve the best possible emergency relief. This paper therefore proposes a multi-objective, multi-mode, multi-commodity, and multi-period stochastic model to manage the logistics of both commodities and injured people in the earthquake response. Also, a robust approach is developed and used to make sure that the distribution plan performs well under the various situations that can follow an earthquake. Afterwards, it proposes a solution methodology according to hierarchical objective functions and uses it to illustrate the...