y. rabbani

Magnetorheological fluids contain suspended magnetic particles that arrange in chains in the presence of a magnetic field, causing the conversion of the fluid from a liquid state to a quasi-solid state. These fluids can be used in valves as a tool for pressure drop and flow interruption. This research aims to investigate the feasibility of using magnetorheological fluid (MRF) in industrial valves. The rheological properties of the MRF sample were measured with the MCR300 rheometer in the presence of a magnetic field. In this connection, the Bingham plastic continuous model was used to predict fluid behavior, and model coefficients were obtained using MATLAB software. Then, the model's coefficients were used to simulate the behavior of the magnetorheological fluid in the presence of the magnetic field in the valve. The geometry and dimensions of the valve were designed according to the dimensions of industrial samples. Then the CFD simulation with Fluent software was done by using the Bingham model and fluid characteristics obtained from experimental results. The results showed that the pressure increased by increasing the magnetic field at the center of the sleeve. The magnetic field up to 0.5 Tesla, increases pressure and decreases amplitude. Therefore, as the magnetic field increase, the amplitude of the maximum pressure on the sleeve was significantly reduced.

Due to the separation of light and heavy phases in the distillation towers of the petrochemical industries, some hydrocarbons have been burned in the flare. Combustion of these gases produces toxic and dangerous gases by the flare and vent into the environment. In the stripping tower of Jam Petrochemical LLDPE Unit, a large number of hydrocarbons is released from the top of the tower. In this study, by providing a suitable solution, toxic and dangerous gases can be prevented from entering the atmosphere, and also the energy of fossil fuels and their compounds can be used from an economic point of view. Therefore, the combined cycle has been used to produce power and water vapor useful for the unit itself. To enable power and steam production, the output results of the unit, as well as the combined cycle, have been simulated using ASPEN-PLUS software. The results showed that the use of the combined cycle produces 29.9 MW of power and also 3500 kg / h of steam. From this amount of power generated, all the required electricity related to the compressor of the linear light polyethylene unit can be supplied, and also the generated steam can cover the steam related to the steamer area and prevent the entry of toxic and dangerous gases into the environment.

This research aims to evaluate the effects of dopamine as a link in the hydrophobicity of carbonyl iron particles with stearic acid. In this connection, the effect of stearic acid and oleic acid on the hydrophobicity of carbonyl iron was also investigated. For this purpose, the FESEM analysis was used to observe the surface modification of the particles, and the surface structure of the particle was studied. Also, the magnetic properties of hydrophobic particles were measured by VSM and Magnetic saturation of CI, CI @ Stearic acid and CI @ Dopamine @ Stearic Acid is 200, 169, 131 emu/g respectively,  in which this decrease is not significant. Finally, the contact angles of samples were measured. Basing on the result, the static contact angle of a water drop placed on a bed of the CI @ Oleic acid, CI @ Stearic acid, and CI @ Dopamine @ Stearic Acid were found to be 156.2°, 162.9°, and 169.022° respectively. The result showed that dopamine has a good effect as a link to the hydrophobicity of particles.

What has initiated the idea of this research is the situation of marine, rail and road transportations in the south region of Iran, the Persian Gulf and Oman see. There are a few large Iranian ports in the region (e.g. Imam Khomeini and Shahid Rajaee) that have been equipped to serve large containerships while, most of the other ports either have not been developed or their geographical and topological restrictions do not let them to serve large ships. For instance, Abadan and Khorramshahr were two active ports and main Iranian Import/Export terminals until the Iraqi army attacked them in 1981. Although, the war finished in 1989, nowadays these are unable to serve current fleet of large container ships due to the limitation of their water way, the Arvand-River. Therefore, their rail and road transportation system's capacity are mostly unused. On the other hand, due to the national economic development programs and the especial attention to the Iranian 20 year's economic vision, Iran needs to develop continuously new transportation capacities as well as better utilization of the existing capacities. To develop the transportation capacity, one way is to invest on the existing ports in order to serve larger ships. However, in one hand, the investment should continuously grow because, as the literature shows, mega-ships and rapid-ships are going to emerge until the year 2020. On the other hand, some of the ports, due to their geographical situation, are not able to catch any share of those investments. Therefore, we need to find a way to activate the small ports to use their capacities.A way that could be theoretically investigated is that the large ports could be used as hobs (intermediate centers) to feed the transportation network (include small ports and ships). In this case, it might be possible to plan a rout for a mega-ship which comes from a depot (outside the region, such as the sought east of Asia) so that it discharges goods at some ports in the region (the Iranian and other nation ports in the Persian Gulf, Oman Sea and the Mouth of Indian Ocean), and then set back to the depot. Consequently, the discharged goods are handled to some consumer centers (the centers in Iran as well as the transit destinations like: Afghanistan, Iraq, Turkey, Russia, and the new independent countries in north of Iran) by a multimodal network (with road, rail and marine modes). Applying this idea could brisk up the utilization of the Iranian private fleets and ports in the region. That is because in one hand, there are plenty of small and medium size ships (that are mostly private ones), which could provide us with a large amount of marine capacity among Iranian and other nations ports in the region. On the other hand, most of the Iranian ports are not able to serve large ships. Moreover, some of the countries in the region (e.g. Pakistan and the Arab Emirates) have extensively invested on some of their ports, so those ports could be used to brisk up utilization of the Iranian fleets and ports and to increase the transit of goods through Iran. In this case, an opportunity rises to get advantage of other nations capitals in order to speed up the flow of goods to/from Iran. However, in order to get advantage of this opportunity, its feasibility, conditions, benefits and other political and social aspects should be studied. This paper concerns with studying the network aspects of the idea in order to evaluate its costs and possibly optimize them. From the network design point of view, the network among the depot and the intermediate ports of the marine transportation network could be considered as a Split Delivery VRP (SDVRP) except than that the demands of the customers (the intermediate centers) are not known in advance, and they are variables to be decided. In the split delivery vehicle routing problem (SDVRP), a fleet of homogeneous vehicles should serve a set of customers, while each customer can be visited more than once, contrary to the assumption in the VRP. So, the demand of each customer can be greater than the capacity of the vehicles. No constraint on the number of available vehicles is considered. Moreover, the network among the intermediate and the consumer centers is a multimodal transportation one in which the goods supplies at the intermediate centers are not known in advance and they are variables to be decided. In this network, it is possible to change the mode of transportation at some of the intermediate or consumer centers with some charges. In this paper the idea has been introduced and, a general transportation system based on it has been originally designed and modeled. The system consists of a Split Delivery Vehicle Routing contiguous to a Multimodal Transportation. The system has originally been modeled and solved in this paper using exact and heuristic methods. The branch-and-bound technique has been used to solve small size test problems. Moreover, in order to solve larger size instances, a heuristic method, called SB-RAB, has been developed which works based on limited entry Simplex method. SB-RAB has been applied to solve two series of test problems which have been barrowed from the VRP literature. Both exact and SB-RAB algorithms are then applied to solve a series of problems which has been adapted in this paper from a set of VRP benchmark problems. Finally the results have been compared and show that the SB-RAB is able to produce good quality solutions in an acceptable time.