gh. r. moradi

The purpose of desalination in production units is to separate salt and water from the flow of crude oil in order to prevent corrosion and damage to facilities. In this study, the effect of effective parameters including temperature, demulsifier injection rate, dilution water injection rate and desalting device voltage on the efficiency of the desalination process of crude oil by electrostatic method to reach optimal conditions (Reaching the amount of salt and water in oil to less than 10 pounds per thousand barrels and 0.1 percent by volume, respectively) has been investigated. An increase in oil temperature causes a decrease in viscosity and accelerates the desalination process, and in this study, the optimum value was obtained at 48 degrees Celsius. Injection of demulsifier at the rate of 40 ppm and diluting water at the rate of 3% by volume of oil is necessary to achieve the highest separation efficiency. By applying 20 Kv of direct current in the desalination plant, the lowest amount of salt and energy consumption can be achieved.

Efforts to improve the effectiveness of noise barriers have been made, including shape, aesthetics, form and gender. Therefore, the aim of this study was to investigate the effect of the angle upper edge in shaped noise barriers with a T-shaped upper edge. A 2D boundary element method (BEM) was used to predict the insertion loss of the tested barriers. The results obtained from the angular obstructions of the upper edge with the upper T-face were compared. The design of the angular barriers of the upper edge in the shape of the barrier caused a significant increase in the insertion loss performance, especially in the low frequency range, as compared to the upper T-shaped face. The highest amount of insertion loss in the angular barriers of the upper edge in the shaped barriers was estimated to be 3.79 dB (A) above the upper edge of T, which usually depends on the relative dimensions and position relative to the source and location of the receiver. The results of this study showed that among the tested models to determine the efficiency, the best noise barrier for controlling the traffic noise was the angular barrier with a high angle of 19 degrees compared to the other higher angles and a simple T barrier at a frequency of 315, 400, 500, and 630 Hz was obtained. The performance of the barriers  in the case of applying the angle at the upper edge on the T-shaped barrier surface is improved in comparison with the use of a simple T-barrier in lower frequencies. In this regard, the best form for applying angular obstructions with a high angle was about 19 degrees from the horizon.. The cause of this effect was the presence of a failure and reflection of the angled edges in the direction of transmission of sound wave from source to receiver. All angular barrier are able to increase the barrier performance at a specific frequency range, especially at low frequencies.

In this paper a new method of Impedance matching for microstrip line by tunneling of electromagnetic energy in epsilon near zero metamaterial are proposed. In this method the size of impedance matcher by use of this properties of ENZ that wave in whole ENZ is in phase, become smaller than other types of impedance matcher like quadrature wavelength transducer. In this method, the bandwidth of matching is related to bandwidth of ENZ. In this paper for implementation of ENZ we utilize of a rectangular waveguide that operate in TE10 mode. The bandwidth of proposed method is 10%-15% around the center frequency. By use of proposed method impedance matching for a 100Ω microstrip lines are simulated and designed.